Systems and methods for processing transparent materials using adjustable laser beam focal lines

Information

  • Patent Grant
  • 11648623
  • Patent Number
    11,648,623
  • Date Filed
    Tuesday, July 14, 2015
    8 years ago
  • Date Issued
    Tuesday, May 16, 2023
    11 months ago
Abstract
A system for and a method of processing a transparent material, such as glass, using an adjustable laser beam line focus are disclosed. The system for processing a transparent material includes a laser source operable to emit a pulsed laser beam, and an optical assembly (6′) disposed within an optical path of the pulsed laser beam. The optical assembly (6′) is configured to transform the pulsed laser beam into a laser beam focal line having an adjustable length and an adjustable diameter. At least a portion of the laser beam focal line is operable to be positioned within a bulk of the transparent material such that the laser beam focal line produces a material modification along the laser beam focal line. Method of laser processing a transparent material by adjusting at least one of the length of the laser beam focal line and the diameter of the laser beam focal line is also disclosed.
Description
BACKGROUND

In recent years, precision micromachining and its improvement of process development to meet customer demand to reduce the size, weight and material cost of leading-edge devices has led to fast pace growth in high-tech industries in flat panel displays for touch screens, tablets, smartphones and TVs. Ultrafast industrial lasers are becoming important tools for applications requiring high precision micromachining.


There are various known ways to cut glasses. In conventional laser glass cutting processes, the separation of glass relies on laser scribing or perforation followed by separation with mechanical force or thermal stress-induced crack propagation. Nearly all current laser cutting techniques exhibit one or more shortcomings. For example, glass cutting by laser processes employing Gaussian laser beams require a large number of pulses to create the desired damage lines within the glass substrate due to the tight focus of the laser beam. Such laser cutting processes may be time consuming and therefore limit throughput.


SUMMARY

The embodiments disclosed herein relate to methods and systems that create small (few micron and smaller) “holes” in transparent materials (glass, sapphire, etc.) for the purpose of drilling, cutting, separating, perforating, or otherwise processing the materials. More particularly, an ultrashort (i.e., from 10−10 to 10−15 second) pulse laser beam (wavelengths such as 1064, 532, 355 or 266 nanometers) is focused to a line focus having an energy density above the threshold needed to create a defect in the region of focus at the surface of or within the transparent material. The length and diameter of the line focus is adjusted according to the type and thickness of the transparent material. By repeating the process, a series of laser-induced defects aligned along a predetermined path can be created. By spacing the laser-induced features sufficiently close together, a controlled region of mechanical weakness within the transparent material can be created and the transparent material can be precisely fractured or separated (immediately, or later with additional mechanical or thermal separation step) along the path defined by the series of laser-induced defects. In the case of high internal stress materials such as chemically strengthened glasses, the material may immediately fracture and separate along the path defined by the laser induced defects. In the case of low stress materials such as glasses made for TFT (thin film transistor) display applications, an additional separation step may be needed. Hence the ultrashort, line focus laser pulse(s) may be optionally followed by a carbon dioxide (CO2) laser or other source of thermal stress to effect fully automated separation of a transparent material or part from a substrate, for example.


In one embodiment, a system for processing a transparent material includes a laser source operable to emit a pulsed laser beam, and an optical assembly disposed within an optical path of the pulsed laser beam. The optical assembly is configured to transform the pulsed laser beam into a laser beam focal line having an adjustable length and an adjustable diameter. At least a portion of the laser beam focal line is operable to be positioned within a bulk of the transparent material such that the laser beam focal line generates an induced multi-photon absorption within the transparent material. The induced multi-photon absorption produces a material modification within the transparent material along the laser beam focal line.


In another embodiment, a method of processing a transparent material includes focusing a pulsed laser beam to form a laser beam focal line along a beam propagation direction, wherein the laser beam focal line has a length and a diameter. The method further includes adjusting at least one of the length of the laser beam focal line and the diameter of the laser beam focal line, and directing the laser beam focal line into the transparent material such that at least a portion of the laser beam focal line is within a bulk of the material. The laser beam focal line generates an induced multi-photon absorption within the transparent material. The induced multi-photon absorption produces a material modification within the material along the laser beam focal line.





BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be apparent from the following more particular description of the example embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the representative embodiments.



FIG. 1 is a schematic illustration of a stack of three layers: a thin material A facing the laser energy, a modified interface, and a thick material B, the modified interface disrupting the laser energy form interacting with the portion of the stack on the side of the modified interface remote from the laser beam;



FIGS. 2A and 2B are schematic illustrations of positioning of the laser beam focal line, i.e., laser processing of a material transparent to the laser wavelength due to the induced absorption along the focal line;



FIG. 3A is a schematic illustration of an optical assembly for laser processing;



FIGS. 3B-1, 3B-2, 3B-3, and 3B-4 illustrate various possibilities for processing the substrate by forming the laser beam focal line at different positions within the transparent material relative to the substrate;



FIG. 4 is a schematic illustration of a second optical assembly for laser processing;



FIGS. 5A and 5B are schematic illustrations of a third optical assembly for laser processing;



FIG. 6A is a schematic illustration of a fourth optical assembly for laser processing;



FIG. 6B is a schematic illustration of an axicon for laser processing;



FIG. 6C is a schematic illustration of a fifth optical assembly for laser processing;



FIG. 6D is a schematic illustration of a sixth optical assembly for laser processing;



FIG. 6E is a schematic illustration of a seventh optical assembly for laser processing;



FIG. 6F is a schematic illustration of a eighth optical assembly for laser processing;



FIG. 6G is a schematic illustration of a ninth optical assembly for laser processing;



FIG. 7 is a graph of laser emission as a function of time for a picosecond laser. Each emission is characterized by a pulse “burst” which may contain one or more sub-pulses. The frequency of the bursts is the repetition rate of the laser, typically about 100 kHz (10 μsec). The time between sub-pulses is much shorter, e.g., about 20 nanoseconds (nsec);



FIG. 8 is a comparison between a focused Gaussian beam and a Bessel beam incident upon a glass-air-glass composite structure;



FIG. 9 is a schematic illustration of stacking with transparent protective layers to cut multiple sheets while reducing abrasion or contamination;



FIG. 10 is a schematic illustration of an air gap and cutting of encapsulated devices;



FIG. 11 is a schematic illustration of cutting of interposers or windows with laser perforation then etch or laser perforation and CO2 laser release;



FIG. 12 is a schematic illustration of cutting an article such as electrochromic glass coated with transparent conductive layers (e.g. indium tin oxide (ITO)); and



FIG. 13 is a schematic illustration of precision cutting of some layers in a stack while not damaging others.





DETAILED DESCRIPTION

Embodiments described herein relate to methods and systems for optically producing high precision cuts in or through transparent materials. Sub-surface damage from the cutting process may be limited to the order of 60 microns in depth or less, and the cuts may produce only low debris. Cutting of a transparent material with a laser in accordance with the present disclosure may also be referred to herein as drilling or laser drilling or laser processing. A material is substantially transparent to the laser wavelength when the absorption is less than about 10%, preferably less than about 1% per mm of material depth at this wavelength.


Generally, a laser beam is transformed to a laser beam focus line that is positioned within the bulk of a material, such as glass, to create damage lines within the material. The material may then be separated along these damage lines. The laser beam focus line may also be utilized to fabricate holes in a material, such as hole in an interposer of a semiconductor device assembly. Systems and methods for adjusting the length and the diameter of the laser line focus are described herein. The length and/or diameter of the laser line focus may be adjusted according to different types of materials as well as materials of different thicknesses.


In accordance with methods described below, in a single pass, a laser can be used to create highly controlled full line perforation through the material, with extremely little (<75 μm, often <50 μm) subsurface damage and debris generation. This is in contrast to the typical use of spot-focused laser to ablate material, where multiple passes are often necessary to completely perforate the glass thickness, large amounts of debris are formed from the ablation process, and more extensive sub-surface damage (>100 μm) and edge chipping occur.


Thus, it is possible to create a microscopic (i.e., <0.5 μm and >100 nm in diameter) elongated “hole” (also called a perforation or a defect line) in transparent material using a single high energy burst pulse. According to the exemplary embodiments described herein a typical perforation will have a diameter of >100 nm and less than 5 micrometer, for example 0.2 to 2 microns, 0.2 to 1 micron, or therebetween; and a length of 50 microns or greater (e.g., 0.1 mm to 100 mm, 150 microns to 2 mm, or 150 microns to 5 mm, or 150 microns to 10 mm). These perforations, defect regions, damage tracks, or defect lines are generally spaced from 1 to 25 microns apart, in some embodiments 1-15 microns apart (for example, 2-12 microns, 5-10 microns), but in some embodiments 15-25 microns apart. These individual perforations can be created at rates of several hundred kilohertz (several hundred thousand perforations per second, for example). Thus, with relative motion between the source and the material these perforations can be placed adjacent to one another (spatial separation varying from sub-micron to several microns as desired). This spatial separation is selected in order to facilitate cutting. In some embodiments, the defect line is a “through hole”, which is a hole or an open channel that extends from the top to the bottom of the transparent material. In some embodiments the defect line may not be a continuous channel, and may be blocked or partially blocked by portions or sections of solid material (e.g., glass). As defined herein, the internal diameter of the defect line is the internal diameter of the open channel or the air hole. For example, in the embodiments described herein the internal diameter of the defect line is <500 nm, for example ≤400 nm, or ≤300 nm. The disrupted or modified area (e.g., compacted, melted, or otherwise changed) of the material surrounding the holes in the embodiments disclosed herein, preferably has diameter of <50 μm (e.g., <10 μm).


Micromachining and selective cutting of a stack of transparent materials is accomplished with precise control of the depth of cut through selection of an appropriate laser source and wavelength along with beam delivery optics, and the placement of a beam disruption element at the boundary of a desired layer. The beam disruption element may be a layer of material or an interface. The beam disruption element may be referred to herein as a laser beam disruption element, disruption element or the like. Embodiments of the beam disruption element may be referred to herein as a beam disruption layer, laser beam disruption layer, disruption layer, beam disruption interface, laser beam disruption interface, disruption interface, or the like.


The beam disruption element reflects, absorbs, scatters, defocuses or otherwise interferes with an incident laser beam to inhibit or prevent the laser beam from damaging or otherwise modifying underlying layers in the stack. In one embodiment, the beam disruption element underlies the layer of transparent material in which laser drilling will occur. As used herein, the beam disruption element underlies the transparent material when placement of the beam disruption element is such that the laser beam must pass through the transparent material before encountering the beam disruption element. The beam disruption element may underlie and be directly adjacent to the transparent layer in which laser drilling will occur. Stacked materials can be micromachined or cut with high selectivity by inserting a layer or modifying the interface such that a contrast of optical properties exists between different layers of the stack. By making the interface between materials in the stack more reflective, absorbing, and/or scattering at the laser wavelengths of interest, cutting can be confined to one portion or layer of the stack.


The wavelength of the laser is selected so that the material within the stack to be laser processed (drilled, cut, ablated, damaged or otherwise appreciably modified by the laser) is transparent to the laser wavelength. In one embodiment, the material to be processed by the laser is transparent to the laser wavelength if it absorbs less than 10% of the intensity of the laser wavelength per mm of thickness of the material. In another embodiment, the material to be processed by the laser is transparent to the laser wavelength if it absorbs less than 5% of the intensity of the laser wavelength per mm of thickness of the material. In still another, the material to be processed by the laser is transparent to the laser wavelength if it absorbs less than 2% of the intensity of the laser wavelength per mm of thickness of the material. In yet another embodiment, the material to be processed by the laser is transparent to the laser wavelength if it absorbs less than 1% of the intensity of the laser wavelength per mm of thickness of the material.


The selection of the laser source is further predicated on the ability to induce multi-photon absorption (MPA) in the transparent material. MPA is the simultaneous absorption of multiple photons of identical or different frequencies in order to excite a material from a lower energy state (usually the ground state) to a higher energy state (excited state). The excited state may be an excited electronic state or an ionized state. The energy difference between the higher and lower energy states of the material is equal to the sum of the energies of the two or more photons. MPA is a nonlinear process that is several orders of magnitude weaker than linear absorption. In the case of two-photon absorption, it differs from linear absorption in that the strength of absorption depends on the square of the light intensity, thus making it a nonlinear optical process. At ordinary light intensities, MPA is negligible. If the light intensity (energy density) is extremely high, such as in the region of focus of a laser source (particularly a pulsed laser source), MPA becomes appreciable and leads to measurable effects in the material within the region where the energy density of the light source is sufficiently high. Within the focal region, the energy density may be sufficiently high to result in ionization, breaking of molecular bonds, and vaporization of material.


At the atomic level, the ionization of individual atoms has discrete energy requirements. Several elements commonly used in glass (e.g., Si, Na, K) have relatively low ionization energies (˜5 eV). Without the phenomenon of MPA, a wavelength of about 248 nm would be required to create linear ionization at ˜5 eV. With MPA, ionization or excitation between states separated in energy by ˜5 eV can be accomplished with wavelengths longer than 248 nm. For example, photons with a wavelength of 532 nm have an energy of ˜2.33 eV, so two photons with wavelength 532 nm can induce a transition between states separated in energy by ˜4.66 eV in two-photon absorption (TPA), for example.


Thus, atoms and bonds can be selectively excited or ionized in the regions of a material where the energy density of the laser beam is sufficiently high to induce nonlinear TPA of a laser wavelength having half the required excitation energy, for example. MPA can result in a local reconfiguration and separation of the excited atoms or bonds from adjacent atoms or bonds. The resulting modification in the bonding or configuration can result in non-thermal ablation and removal of matter from the region of the material in which MPA occurs. This removal of matter creates a structural defect (e.g. a defect line or “perforation”) that mechanically weakens the material and renders it more susceptible to cracking or fracturing upon application of mechanical or thermal stress. By controlling the placement of perforations, a contour or path along which cracking occurs can be precisely defined and precise micromachining of the material can be accomplished. The contour defined by a series of perforations may be regarded as a fault line and corresponds to a region of structural weakness in the material. In one embodiment, micromachining includes separation of a part from the material processed by the laser, where the part has a precisely defined shape or perimeter determined by a closed contour of perforations formed through MPA effects induced by the laser. As used herein, the term closed contour refers to a perforation path formed by the laser line, where the path intersects with itself at some location. An internal contour is a path formed where the resulting shape is entirely surrounded by an outer portion of material.


Perforations can be accomplished with a single “burst” of high energy short duration pulses spaced close together in time. The laser pulse duration may be 10−10 s or less, or 10−11 s or less, or 10−12 s or less, or 10−13 s or less. These “bursts” may be repeated at high repetition rates (e.g. kHz or MHz). The perforations may be spaced apart and precisely positioned by controlling the velocity of a substrate or stack relative to the laser through control of the motion of the laser and/or the substrate or stack.


As an example, in a thin transparent substrate moving at 200 mm/sec exposed to a 100 kHz series of pulses, the individual pulses would be spaced 2 microns apart to create a series of perforations separated by 2 microns. This defect (perforation) spacing is sufficient close to allow for mechanical or thermal separation along the contour defined by the series of perforations.


Thermal Separation:


In some cases, a fault line created along a contour defined by a series of perforations or defect lines is not enough to separate the part spontaneously, and a secondary step may be necessary. If so desired, a second laser can be used to create thermal stress to separate it, for example. In the case of sapphire, separation can be achieved, after the creation of a fault line, by application of mechanical force or by using a thermal source (e.g., an infrared laser, for example a CO2 laser or a CO laser) to create thermal stress and force a part to separate from a substrate. The optional thermal separation can be achieved, for example, with a defocused CO2 laser continuous wave (cw) laser emitting at 10.6 μm and with power adjusted by controlling its duty cycle. Focus change (i.e., extent of defocusing up to and including focused spot size) is used to vary the induced thermal stress by varying the spot size. Defocused laser beams include those laser beams that produce a spot size larger than a minimum, diffraction-limited spot size on the order of the size of the laser wavelength. For example, spot sizes of about 7 mm, 2 mm and 20 mm can be used for CO2 lasers, for example, whose emission wavelength is much smaller at 10.6 μm. Distance between adjacent defect lines 120 along the direction of the fault lines 110 can be, for example, greater than 0.5 μm and less than or equal to about 15 or 20 μm in some embodiments. Another option is to have the CO2 laser only start the separation and then finish the separation manually, i.e. by applying mechanical force to separate the part along the laser-perforated contour.


Etching:


Acid etching can be used, for example, to separate a workpiece having a glass layer, for example. To enlarge the holes to a size useful for metal filling and electrical connections, parts can be acid etched. In one embodiment, for example, the acid used can be 10% HF/15% HNO3 by volume. The parts can be etched for 53 minutes at a temperature of 24-25° C. to remove about 100 μm of material, for example. The parts can be immersed in this acid bath, and ultrasonic agitation at a combination of 40 kHz and 80 kHz frequencies can used to facilitate penetration of fluid and fluid exchange in the holes. In addition, manual agitation of the part within the ultrasonic field can be made to prevent standing wave patterns from the ultrasonic field from creating “hot spots” or cavitation related damage on the part. The acid composition and etch rate can be intentionally designed to slowly etch the part—a material removal rate of only 1.9 um/minute, for example. An etch rate of less than about 2 μm/minute, for example, allows acid to fully penetrate the narrow holes and agitation to exchange fresh fluid and remove dissolved material from the holes which are initially very narrow.


In the embodiment shown in FIG. 1, precise control of the depth of cut in a multilayer stack is achieved by inclusion of a beam disruption interface (labeled “modified interface”). The beam disruption interface prevents the laser radiation from interacting with portions of the multilayer stack beyond the position of the disruption interface. Although embodiments are shown and described herein as utilizing a multilayer stack, it should be understood that embodiments are not limited thereto. The laser cutting process using the laser beam line focus attributes described herein may be applied to a single layer of material, such as a glass substrate.


In one embodiment, the beam disruption element is positioned immediately below the layer of the stack in which modification via two-photon absorption will occur. Such a configuration is shown in FIG. 1, where the beam disruption element is a modified interface positioned immediately below material A and material A is the material in which formation of perforations through the two-photon absorption mechanism described herein will occur. As used herein, reference to a position below or lower than another position assumes that the top or uppermost position is the surface of the multilayer stack upon which the laser beam is first incident. In FIG. 1, for example, the surface of material A that is closest to the laser source is the top surface and placement of the beam disruption element below material A means that the laser beam traverses material A before interacting with the beam disruption element.


The disruption element has different optical properties than the material to be cut. For example, the beam disruption element may be a defocusing element, a scattering element, a translucent element, or a reflective element. A defocusing element is an interface or a layer comprising a material that prevents the laser light from forming the laser beam focal line on or below the defocusing element. The defocusing element may be comprised of a material or interface with refractive index inhomogeneities that scatter or perturb the wavefront of the optical beam. A translucent element is an interface or layer of material that allows light to pass through, but only after scattering or attenuating the laser beam to lower the energy density sufficiently to prevent formation of a laser beam focal line in portions of the stack on the side of the translucent element that are remote from the laser beam. In one embodiment, the translucent element effects scattering or deviating of at least 10% of the light rays of the laser beam.


More specifically, the reflectivity, absorptivity, defocusing, attenuation, and/or scattering of the disruption element can be employed to create a barrier or impediment to the laser radiation. The laser beam disruption element can be created by several means. If the optical properties of the overall stack system are not of a concern, then one or more thin films can be deposited as a beam disruption layer(s) between the desired two layers of the stack, where the one or more thin films absorb, scatter, defocus, attenuate, reflects, and/or dissipates more of the laser radiation than the layer immediately above it to protect layers below the thin film(s) from receiving excessive energy density from the laser source. If the optical properties of the entire stack system do matter, the beam disruption element can be implemented as a notch filter. This can be done by several methods:

    • a) creating structures at the disruption layer or interface (e.g. via thin film growth, thin film patterning, or surface pattering) such that diffraction of incident laser radiation is at a particular wavelength or range of wavelengths occurs;
    • b) creating structures at the disruption layer or interface (e.g. via thin film growth, thin film patterning, or surface pattering) such that scattering of incident laser radiation occurs (e.g. a textured surface);
    • c) creating structures at the disruption layer or interface (e.g. via thin film growth, thin film patterning, or surface pattering) such that attenuated phase-shifting of laser radiation occurs; and
    • d) creating a distributed Bragg reflector via thin-film stack at the disruption layer or interface to reflect only laser radiation.


It is not necessary that the absorption, reflection scattering, attenuation, defocusing etc. of the laser beam by the disruption element be complete. The effect of the disruption element, when utilized, on the laser beam should be sufficient to reduce the energy density or intensity of the focused laser beam to a level below the threshold required for cutting, ablation, perforating etc. of the layers in the stack protected by (underlying) the disruption element. In one embodiment, the disruption element reduces the energy density or intensity of the focused laser beam to a level below the threshold needed to induce two-photon absorption. The disruption layer or disruption interface may be configured to absorb, reflect, or scatter the laser beam, where the absorption, reflection, or scattering are sufficient to reduce the energy density or intensity of the laser beam transmitted to the carrier (or other underlying layer) to a level below the level needed to induce nonlinear absorption in the carrier or underlying layer.


Turning to FIGS. 2A and 2B, a method of laser drilling a material includes focusing a pulsed laser beam 2 into a laser beam focal line 2b, viewed along the beam propagation direction. Laser beam focal line 2b is a region of high energy density. As shown in FIG. 3, laser 3 (not shown) emits laser beam 2, which has a portion 2a incident to optical assembly 6. The optical assembly 6 turns the incident laser beam into an extensive laser beam focal line 2b on the output side over a defined expansion range along the beam direction (length 1 of the focal line).


Embodiments of the present disclosure utilize non-diffracting beams (“NDB”) to form the laser beam focal line 2b. Typically laser processing has used Gaussian laser beams. The tight focus of a laser beam with a Gaussian intensity profile has a Rayleigh range ZR given by:










Z
R

=







n

o



w
o
2



λ
o


.





Eq
.


(
1
)








The Rayleigh range represents the distance over which the spot size w0 of the beam will increase by √{square root over (2)} in a material of refractive index η0 at wavelength η0. This limitation is imposed by diffraction. Note in Eq. (1) that the Rayleigh range is related directly to the spot size, thereby leading to the conclusion that a beam with a tight focus (i.e. small spot size) cannot have a long Rayleigh range. Such a beam will maintain this small spot size only for a very short distance. This also means that if such a beam is used to drill through a material by changing the depth of the focal region, the rapid expansion of the spot on either side of the focus will require a large region free of optical distortion that might limit the focus properties of the beam. Such a short Rayleigh range also requires multiple pulses to cut through a thick sample.


However, embodiments of the present disclosure utilize NDBs instead of the optical Gaussian beams discussed above. Non-diffracting beams may propagate for a considerable distance before diffraction effects inevitably limit the beam focus. Although an infinite NDB does not suffer from diffractive effects, a physically realizable NDB will have a limited physical extent. The central lobe of the beam can be quite small in radius and thus produce a high intensity beam. There are several types of NDBs including, but not limited to, Bessel beams, Airy beams, Weber beams and Mathieu beams whose field profiles are typically given by special functions which decay more slowly in the transverse direction than a Gaussian function.


It should be understood that, although NDBs described are described herein in the context of Bessel beams, embodiments are not limited thereto. The central spot size of a Bessel beam is given by:










d
=

2



2.405

λ
o




NA

2

n

o




,




Eq
.


(
2
)









where NA is the numerical aperture given by the cone of plane waves making an angle of β with the optical axis (see FIG. 6B). A key difference between Bessel beams and Gaussian beams is that Rayleigh range is given by:











Z
max

=




Dd


4

λ



,




Eq
.


(
3
)









where D is the finite extent of the beam imposed by some aperture or optical element. It is therefore shown that the aperture size D may be used to increase the Rayleigh range beyond the limit imposed by the size of the central spot. A practical method for generating Bessel beams is to pass a Gaussian beam through an axicon or an optical element with a radially linear phase element as shown in FIG. 6B.


In general, the optical method of forming the line focus (i.e., the laser beam focal line) can take multiple forms, such as, without limitation, using donut shaped laser beams and spherical lenses, axicon lenses, diffractive elements, or other methods to form the linear region of high intensity. The type of laser (picosecond, femtosecond, and the like) and wavelength (IR, visible, UV, and the like) may also be varied, as long as sufficient optical intensities are reached to create breakdown of the substrate material.


The laser power and lens focal length (which determines the line focus length and hence power density) are parameters that ensure full penetration of the substrate for cutting and drilling, while either purposefully generating cracks between the perforations (damage tracks) in the case of cutting, or possibly trying to suppress micro-cracking in the case of drilling. Accordingly, the dimensions of the line focus formed in the substrate should be precisely controlled.


Embodiments of the present disclosure are directed to systems and methods for adjusting both the diameter and the length of the line focus, enabling, with a single laser machine, the cutting of thin and thick materials, as well as the machining of materials that crack easily versus materials that have very high optical thresholds for material modification. This allows a single system to be rapidly adapted for cutting and drilling different substrates, thereby increasing manufacturing efficiency and improving capital utilization.


Referring once again to FIGS. 2A and 2B, layer 1 is the layer of a multilayer stack in which internal modifications by laser processing and two-photon absorption is to occur. Layer 1 is a component of a larger workpiece, which typically includes a substrate or carrier upon which a multilayer stack is formed. Layer 1 is the layer within the multilayer stack in which holes, cuts, or other features are to be formed through two-photon absorption assisted ablation or modification as described herein. The layer 1 is positioned in the beam path to at least partially overlap the laser beam focal line 2b of laser beam 2. Reference 1a designates the surface of the layer 1 facing (closest or proximate to) the optical assembly 6 or the laser, respectively, reference 1b designates the reverse surface of layer 1 (the surface remote, or further away from, optical assembly 6 or the laser). The thickness of the layer 1 (measured perpendicularly to the planes 1a and 1b, i.e., to the substrate plane) is labeled with d.


As FIG. 2A depicts, layer 1 is aligned perpendicular to the longitudinal beam axis and thus behind the same focal line 2b produced by the optical assembly 6 (the substrate is perpendicular to the plane of the drawing). Viewed along the beam direction, the layer 1 is positioned relative to the focal line 2b in such a way that the focal line 2b (viewed in the direction of the beam) starts before the surface 1a of the layer 1 and stops before the surface 1b of the layer 1, i.e. focal line 2b terminates within the layer 1 and does not extend beyond surface 1b. In the overlapping area of the laser beam focal line 2b with layer 1, i.e. in the portion of layer 1 overlapped by focal line 2b, the extensive laser beam focal line 2b generates nonlinear absorption in layer 1. (Assuming suitable laser intensity along the laser beam focal line 2b, which intensity is ensured by adequate focusing of laser beam 2 on a section of length 1 (i.e. a line focus of length 1), which defines an extensive section 2c (aligned along the longitudinal beam direction) along which an induced nonlinear absorption is generated in the layer 1.) The induced nonlinear absorption results in formation of a defect line or crack in layer 1 along section 2c. The defect or crack formation is not only local, but rather may extend over the entire length of the extensive section 2c of the induced absorption. The length of section 2c (which corresponds to the length of the overlapping of laser beam focal line 2b with layer 1) is labeled with reference L. The average diameter or extent of the section of the induced absorption 2c (or the sections in the material of layer 1 undergoing the defect line or crack formation) is labeled with reference D. This average extent D may correspond to the average diameter δ of the laser beam focal line 2b, that is, an average spot diameter in a range of between about 0.1 μm and about 5 μm.


As FIG. 2A shows, the layer 1 (which is transparent to the wavelength λ of laser beam 2) is locally heated due to the induced absorption along the focal line 2b. The induced absorption arises from the nonlinear effects associated with the high intensity (energy density) of the laser beam within focal line 2b. FIG. 2B illustrates that the heated layer 1 will eventually expand so that a corresponding induced tension leads to micro-crack formation, with the tension being the highest at surface 1a.


Representative optical assemblies 6, which can be applied to generate the focal line 2b, as well as a representative optical setup, in which these optical assemblies can be applied, are described below. All assemblies or setups are based on the description above so that identical references are used for identical components or features or those which are equal in their function. Therefore only the differences are described below.


To insure high quality (regarding breaking strength, geometric precision, roughness and avoidance of re-machining requirements) of the surface of separation after cracking along the contour defined by the series of perforations, the individual focal lines used to form the perforations that define the contour of cracking should be generated using the optical assembly described below (hereinafter, the optical assembly is alternatively also referred to as laser optics). The roughness of the separated surface is determined primarily by the spot size or the spot diameter of the focal line. A roughness of a surface can be characterized, for example, by an Ra surface roughness statistic (roughness arithmetic average of absolute values of the heights of the sampled surface). In order to achieve a small spot size of, for example, 0.5 μm to 2 μm in case of a given wavelength λ of laser 3 (interaction with the material of layer 1), certain requirements must usually be imposed on the numerical aperture of laser assembly 6.


In order to achieve the required numerical aperture, the optics must, on the one hand, dispose of the required opening for a given focal length, according to the known Abbé formulae (N.A.=n sin (theta), n: refractive index of the material to be processed, theta: half the aperture angle; and theta=arctan (D/2f); D: aperture, f: focal length). On the other hand, the laser beam must illuminate the optics up to the required aperture, which is typically achieved by means of beam widening using widening telescopes between the laser and focusing optics.


The spot size should not vary too strongly for the purpose of a uniform interaction along the focal line. This can, for example, be ensured (see the embodiment below) by illuminating the focusing optics only in a small, circular area so that the beam opening and thus the percentage of the numerical aperture only varies slightly.



FIG. 3A depicts one method of generating a line focus. According to FIG. 3A (section perpendicular to the substrate plane at the level of the central beam in the laser beam bundle of laser radiation 2; here, too, laser beam 2 is perpendicularly incident to the layer 1, i.e. incidence angle β is 0° so that the focal line 2b or the extensive section of the induced absorption 2c is parallel to the substrate normal), the laser radiation 2a emitted by laser 3 is first directed onto a circular aperture 8 which is completely opaque to the laser radiation used. Aperture 8 is oriented perpendicular to the longitudinal beam axis and is centered on the central beam of the depicted beam bundle 2a. The diameter of aperture 8 is selected in such a way that the beam bundles near the center of beam bundle 2a or the central beam (here labeled with 2aZ) hit the aperture and are completely blocked by it. Only the beams in the outer perimeter range of beam bundle 2a (marginal rays, here labeled with 2aR) are not blocked due to the reduced aperture size compared to the beam diameter, but pass aperture 8 laterally and hit the marginal areas of the focusing optic elements of the optical assembly 6, which, in this embodiment, is designed as a spherically cut, bi-convex lens 7.


Lens 7 is centered on the central beam and is designed as a non-corrected, bi-convex focusing lens in the form of a common, spherically cut lens. The spherical aberration of such a lens may be advantageous. As an alternative, aspheres or multi-lens systems deviating from ideally corrected systems, which do not form an ideal focal point but a distinct, elongated focal line of a defined length, can also be used (i.e., lenses or systems which do not have a single focal point). The zones of the lens thus focus along a focal line 2b, subject to the distance from the lens center. The diameter of aperture 8 across the beam direction is approximately 90% of the diameter of the beam bundle (defined by the distance required for the intensity of the beam to decrease to 1/e of the peak intensity) and approximately 75% of the diameter of the lens of the optical assembly 6. The focal line 2b of a non-aberration-corrected spherical lens 7 generated by blocking out the beam bundles in the center is thus used. FIG. 3A shows the section in one plane through the central beam, the complete three-dimensional bundle can be seen when the depicted beams are rotated around the focal line 2b.


One potential disadvantage of this type of focal line is that the conditions (spot size, laser intensity) may vary along the focal line (and thus along the desired depth in the material) and therefore the desired type of interaction (no melting, induced absorption, thermal-plastic deformation up to crack formation) may possibly occur only in selected portions of the focal line. This means in turn that possibly only a part of the incident laser light is absorbed by the material to be processed in the desired way. In this way, the efficiency of the process (required average laser power for the desired separation speed) may be impaired, and the laser light may also be transmitted into undesired regions (parts or layers adherent to the substrate or the substrate holding fixture) and interact with them in an undesirable way (e.g. heating, diffusion, absorption, unwanted modification).



FIG. 3B-1-4 show (not only for the optical assembly in FIG. 3A, but also for any other applicable optical assembly 6) that the position of laser beam focal line 2b can be controlled by suitably positioning and/or aligning the optical assembly 6 relative to layer 1 as well as by suitably selecting the parameters of the optical assembly 6: As FIG. 3B-illustrates, the length 1 of the focal line 2b can be adjusted in such a way that it exceeds the layer thickness d (here by factor 2). If layer 1 is placed (viewed in longitudinal beam direction) centrally to focal line 2b, an extensive section of induced absorption 2c is generated over the entire substrate thickness.


In the case shown in FIG. 3B-2, a focal line 2b of length 1 is generated which corresponds more or less to the layer thickness d. Since layer 1 is positioned relative to line 2b in such a way that line 2b starts at a point outside the material to be processed, the length L of the section of extensive induced absorption 2c (which extends here from the substrate surface to a defined substrate depth, but not to the reverse surface 1b) is smaller than the length 1 of focal line 2b. FIG. 3B-3 shows the case in which the layer 1 (viewed along the beam direction) is positioned above the starting point of focal line 2b so that, as in FIG. 3B-2, the length 1 of line 2b is greater than the length L of the section of induced absorption 2c in layer 1. The focal line thus starts within the layer 1 and extends beyond the reverse surface 1b. FIG. 3B-4 shows the case in which the focal line length 1 is smaller than the layer thickness d so that—in the case of a central positioning of the substrate relative to the focal line viewed in the direction of incidence—the focal line starts near the surface 1a within the layer 1 and ends near the surface 1b within the layer 1 (e.g. 1=0.75·d). The laser beam focal line 2b can have a length 1 in a range of between about 0.1 mm and about 100 mm or in a range of between about 0.1 mm and about 10 mm, for example. Various embodiments can be configured to have length 1 of about 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.7 mm, 1 mm, 2 mm, 3 mm or 5 mm, for example.


It is particularly advantageous to position the focal line 2b in such a way that at least one of surfaces 1a, 1b is covered by the focal line, so that the section of induced nonlinear absorption 2c starts at least on one surface of the layer or material to be processed. In this way it is possible to achieve virtually ideal cuts while avoiding ablation, feathering and particulate generation at the surface.



FIG. 4 depicts another applicable optical assembly 6. The basic construction follows the one described in FIG. 3A so that only the differences are described below. The depicted optical assembly is based the use of optics with a non-spherical free surface in order to generate the focal line 2b, which is shaped in such a way that a focal line of defined length 1 is formed. For this purpose, aspheres can be used as optic elements of the optical assembly 6. In FIG. 4, for example, a so-called conical prism, also often referred to as axicon, is used. An axicon is a conically cut lens which forms a spot source on a line along the optical axis (or transforms a laser beam into a ring). The layout of such an axicon is principally known to those of skill in the art; the cone angle in the example is 10°. The apex of the axicon labeled here with reference 9 is directed towards the incidence direction and centered on the beam center. Since the focal line 2b produced by the axicon 9 starts within its interior, layer 1 (here aligned perpendicularly to the main beam axis) can be positioned in the beam path directly behind axicon 9. As FIG. 4 shows, it is also possible to shift layer 1 along the beam direction due to the optical characteristics of the axicon while remaining within the range of focal line 2b. The section of extensive induced absorption 2c in the material of layer 1 therefore extends over the entire depth d.


However, the depicted layout is subject to the following restrictions: Since the region of focal line 2b formed by axicon 9 begins within the axicon 9, a significant part of the laser energy is not focused into the section of induced absorption 2c of focal line 2b, which is located within the material, in the situation where there is a separation between axicon 9 and the material to be processed. Furthermore, length 1 of focal line 2b is related to the beam diameter through the refractive indices and cone angles of axicon 9. This is why, in the case of relatively thin materials (several millimeters), the total focal line is much longer than the thickness of the material to be processed, having the effect that much of the laser energy is not focused into the material.


For this reason, it may be desirable to use an optical assembly 6 that includes both an axicon and a focusing lens. FIG. 5A depicts such an optical assembly 6 in which a first optical element (viewed along the beam direction) with a non-spherical free surface designed to form an extensive laser beam focal line 2b is positioned in the beam path of laser 3. In the case shown in FIG. 5A, this first optical element is an axicon 10 with a cone angle of 5°, which is positioned perpendicularly to the beam direction and centered on laser beam. The apex of the axicon is oriented towards the beam direction. A second, focusing optical element, here the plano-convex lens 11 (the curvature of which is oriented towards the axicon), is positioned in the beam direction at a distance z1 from the axicon 10. The distance z1, in this case approximately 300 mm, is selected in such a way that the laser radiation formed by axicon 10 is circularly incident on the outer radial portion of lens 11. Lens 11 focuses the circular radiation on the output side at a distance z2, in this case approximately 20 mm from lens 11, on a focal line 2b of a defined length, in this case 1.5 mm. The effective focal length of lens 11 is 25 mm in this embodiment. The circular transformation of the laser beam by axicon 10 is labeled with the reference SR.



FIG. 5B depicts the formation of the focal line 2b or the induced absorption 2c in the material of layer 1 according to FIG. 5A in detail. The optical characteristics of both elements 10, 11 as well as the positioning of them is selected in such a way that the length 1 of the focal line 2b in beam direction is exactly identical with the thickness d of layer 1. Consequently, an exact positioning of layer 1 along the beam direction should be provided to position the focal line 2b exactly between the two surfaces 1a and 1b of layer 1, as shown in FIG. 5B.


It is therefore advantageous if the focal line is formed at a certain distance from the laser optics, and if the greater part of the laser radiation is focused up to a desired end of the focal line. As described, this can be achieved by illuminating a primarily focusing element 11 (lens) only circularly (annularly) over a particular outer radial region, which, on the one hand, serves to realize the required numerical aperture and thus the required spot size, and, on the other hand, however, the circle of diffusion diminishes in intensity after the required focal line 2b over a very short distance in the center of the spot, as a basically circular spot is formed. In this way, the crack formation is stopped within a short distance in the required substrate depth. A combination of axicon 10 and focusing lens 11 meets this requirement. The axicon acts in two different ways: due to the axicon 10, a usually round laser spot is sent to the focusing lens 11 in the form of a ring, and the asphericity of axicon 10 has the effect that a focal line is formed beyond the focal plane of the lens instead of a focal point in the focal plane. The length 1 of focal line 2b can be adjusted via the beam diameter on the axicon. The numerical aperture along the focal line, on the other hand, can be adjusted via the distance z1 axicon-lens and via the cone angle of the axicon. In this way, the entire laser energy can be concentrated in the focal line.


If the crack formation is intended to continue to the back side of the layer or material to be processed, the circular (annular) illumination still has the advantage that (1) the laser power is used optimally in the sense that most of the laser light remains concentrated in the required length of the focal line, and (2) it is possible to achieve a uniform spot size along the focal line—and thus a uniform separation process along the perforations produced by the focal lines—due to the circularly illuminated zone in conjunction with the desired aberration set by means of the other optical functions.


Instead of the plano-convex lens depicted in FIG. 5A, it is also possible to use a focusing meniscus lens or another higher corrected focusing lens (asphere, multi-lens system).


In order to generate very short focal lines 2b using the combination of an axicon and a lens depicted in FIG. 5A, a very small beam diameter of the laser beam incident on the axicon may be needed. This has the practical disadvantage that the centering of the beam onto the apex of the axicon must be very precise and that the result is very sensitive to directional variations of the laser (beam drift stability). Furthermore, a tightly collimated laser beam is very divergent, i.e. due to the light deflection the beam bundle becomes blurred over short distances.


As shown in FIG. 6A, both effects can be avoided by including another lens, a collimating lens 12 in the optical assembly 6. The additional collimating lens 12 serves to adjust the circular illumination of focusing lens 11 very tightly. The focal length f′ of collimating lens 12 is selected in such a way that the desired circle diameter dr results from distance z1a from the axicon to the collimating lens 12, which is equal to f′. The desired width br of the ring can be adjusted via the distance z1b (collimating lens 12 to focusing lens 11). As a matter of pure geometry, the small width of the circular illumination leads to a short focal line. A minimum can be achieved at distance f′.


The optical assembly 6 depicted in FIG. 6A is thus based on the one depicted in FIG. 5A so that only the differences are described below. The collimating lens 12, here also designed as a plano-convex lens (with its curvature towards the beam direction) is additionally placed centrally in the beam path between axicon 10 (with its apex towards the beam direction), on the one side, and the plano-convex lens 11, on the other side. The distance of collimating lens 12 from axicon 10 is referred to as z1a, the distance of focusing lens 11 from collimating lens 12 as z1b, and the distance of the focal line 2b from the focusing lens 11 as z2 (always viewed in beam direction). As shown in FIG. 6A, the circular radiation SR formed by axicon 10, which is incident divergently and under the circle diameter dr on the collimating lens 12, is adjusted to the required circle width br along the distance z1b for an at least approximately constant circle diameter dr at the focusing lens 11. In the case shown, a very short focal line 2b is intended to be generated so that the circle width br of approx. 4 mm at collimating lens 12 is reduced to approx. 0.5 mm at lens 11 due to the focusing properties of collimating lens 12 (circle diameter dr is 22 mm in the example).


In the depicted example it is possible to achieve a length of the focal line 1 of less than 0.5 mm using a typical laser beam diameter of 2 mm, a focusing lens 11 with a focal length f=25 mm, a collimating lens with a focal length f′=150 mm, and choosing distances Z1a=Z1b=140 mm and Z2=15 mm.


With reference to FIG. 6B, properties of a NDB formed by an axicon 10 will now be described. FIG. 6B schematically depicts a Gaussian laser beam 2 impinging a flat entrance surface of a transmissive axicon 10. The emergent surface of the axicon 10 deflects the laser beam 2 as shown. The typical energy profile in a plane located at a distance z from the tip of the axicon is given by:

I(r,z)=Io(Rz)Rzk(sin(β)/cos 2(β))Jo2(kr sin(β))  Eq. (4.1),
Rz=z*tan(β)  Eq. (4.2).


Here, β is the ray angle created by the axicon 10, which is a function of the angle of the axicon cone provided by the angled emergent surface and the refractive index of the axicon 10. Io(Rz) is the irradiance profile of the laser beam 2 illuminating the axicon 10, which is assumed to be a Gaussian profile, and k is the wavevector k=2π/λ, and Jo denotes a first-order Bessel function.


To make the strongest damage tracks, or holes, in the hardest of materials, the diameter of the lone focus should be as small as possible. Based on the formulas above, the full width half maximum (“FWHM”) of the irradiance profile in any plane at some distance z from the apex of the axicon 10 is given by:

FWHM=2.52λ/(2π sin(β))  Eq. (4.3).


As can be seen from Eq. (4.3), the diameter of the line focus is related to a single geometric system parameter, the aperture angle β as shown in FIG. 6B.


From Eq. 4.1, at the center of the line focus, the peak power is given by:

I_peak(z)=Io(Rz)Rzk(sin(β)/cos 2(β))  Eq. (4.4).

As can be seen in Eq. (4.4), the peak power is a function of the pupil irradiance profile Io(Rz), as well as a function of the aperture angle β.


If we examine where the on-axis intensity decays to approximately one half of its maximum intensity, then the length (or extent along the optical axis) of the line focus can be approximated by:

0.8*Rz/sin(β)  Eq. (4.5)

Thus the length of the focused line is a function of both the input beam size (Rz) and the aperture angle β.


In a laser cutting machine, the material to be cut may vary in thickness. As an example, such a laser machine may be used to cut glass with thicknesses varying from 0.1 to 2.0 mm. Accordingly, to ensure that it is possible to drill and cut thick material (i.e., glass), the useful portion of the line focus should be set at, for example, at least 2.0 mm by, for instance, spreading the pupil irradiance profile into a larger area. However, by doing so, the peak power density within the line focus will decrease because the maximum value of Io(Rz) decreases. To keep the peak power density greater than the material modification energy density threshold, the aperture angle β should be increased, which means that the FWHM of the line focus will decrease.


Therefore, in a system with a fixed choice of optics, the parameters should be adjustable for the most difficult cases. When cutting thinner substrates (e.g. 100 μm thick display glass), much of the laser energy may be wasted if a long line focus is set to allow cutting of thick materials (e.g. stacks of ion exchanged glass). Similarly, if the optics are set to produce a very short and small diameter line focus (high energy density) to cut very thin and hard materials (e.g. sapphire), the optical system may no longer work well for thicker materials (e.g., thick soda lime glass or ion-exchangeable glass substrates).


For at least these reasons, it may be desirable for making the irradiance profile Io(Rz) and/or the aperture angle β adjustable. It is desirable to have both parameters adjustable to apply the following strategy: for each glass thickness and material:

    • adjust the input irradiance profile to achieve the desired line focus length; and
    • adjust the aperture angle to set the FWHM (or diameter) of the laser beam at the line focus, keeping the energy density optimal for modification of the given material.


It may be desirable to set the FWHM (or diameter) of the line focus 2b to be as narrow as possible, which allows the lowest laser power to be used to create the damage tracks within the material and hence provide the most process margin. However, in some cases, it may be desirable to have a larger diameter line focus, which reduces the amount of micro-cracking around the damage tracks. For example, larger diameter spots are helpful in drilling of holes that are subsequently acid-etched, where micro-cracks are not desired as they may create etch asymmetries. The upper limitation on the diameter of the line focus is that, given a maximum laser pulse energy available for a laser source, sufficient energy density must still be reached to allow modification of the material and creation of a damage track.


For the length of the line focus 2b, it is desirable to make it at least equal to but preferentially greater than the thickness of the material, accounting for the fact that per Snell's law of refraction, the refractive index of the material (e.g. for glass n˜1.5) increases the effective length of the line focus 2b within the material itself. Longer focal lines give larger focus tolerance, and also allow various substrate thicknesses to be accommodated. The upper limitation upon the focal line length is again that, given a maximum laser pulse energy available for a laser source, sufficient energy density must still be reached to allow modification of the material and creation of a damage track throughout the thickness of the substrate.



FIGS. 6C and 6E-6G depict non-limiting optical systems that allow for the adjustment of the length and the FWHM (i.e., the diameter) of the laser beam focal line 2b (i.e., line focus). FIG. 6C depicts a system for cutting a material (not shown) using a laser beam focal line 2b. The system comprises a laser source 3 (not shown) and an optical assembly 6′ configured to transform a Gaussian profile laser beam 2 into a Bessel profile laser beam having a focal line 2b. The optical assembly 6′ is disposed within an optical path 1 of the laser beam 2, and comprises a transparent (i.e. acting as a refractive element) axicon 10, a first lens element 5 having a first focal length F1, and a second lens element 11 (i.e., a focusing lens element) having a second focal length F2.


The transparent axicon 10 forms a line focus 2b′ that is imaged by the first lens element 5 and the second lens element 11, which act as a telescope that relays and magnifies the line focus 2b′ formed by the axicon 10 into the line focus 2b that is applied to the material. The magnification of the telescope defined by the first lens element 5 and the second lens element 11 is given by M=F2/F1, which may be varied by changing one or both of the two lens elements to achieve a different magnification M. The length of the line focus 2b gets scaled with the square of the magnification, while the diameter of the line focus in a given z-plane is scaled linearly with magnification.


Changing the focal length of the first and/or second lens 5, 11 may not be optimal in some applications as both line focus length and width scale together. Assuming that M is the magnification provided by the first and second focal lengths:

FWHM1=FWHM0*M  Eq. (5.1);
Length1=Length0*M2  Eq. (5.2).


Here FWHM0 denotes the full-width at half maximum diameter of the line focus formed immediately after the axicon 10, and FWHM1 denotes the full-width at half maximum diameter of the line focus formed after the second lens element 11. Similarly LENGTH0 denotes the length, or spatial extent along the optical axis, of the line focus formed immediately after the axicon 10, and LENGTH1 denotes the length of the line focus formed after the second lens element 11. If it is assumed that the resulting line focus 2b takes the form of a cylinder of length and diameter dimensions Length1×FWHM1, then the power (or energy) density inside the cylinder will scale as 1/volume of that object, where volume=(pi/4)*diameter2*length. This means the power density will scale as:

PowerDensity1=PowerDensity0/M4  Eq. (5.3).


Thus, the diameter of the line focus increases linearly with the magnification of the telescope provided by the first and second lenses 5, 11, the length of the line focus 2b increases as the square of the magnification, and the power or energy density scales at one over the 4th power of the magnification. This means that as shorter focal length lenses are used for F2, the diameter of the focus drops, the length gets much shorter, and the power density increases rapidly.


In some embodiments, an axicon 10 with an adjustable angle is provided as a third degree of freedom to achieve a system that is capable of adjusting both the length and diameter of the line focus 2b. Suppose that the angle of the original axicon 10 discussed above is multiplied by a factor A. Then, assuming small angles (i.e., (sin(α)≈α), the following is true:

FWHM2=FWHM1/A  Eq. (6.1); and
Length2=Length1/A  Eq. (6.2).

Here, if an amplification A creates a larger axicon angle, then the FWHM (i.e., the diameter) of the line focus 2b gets smaller and the length of the line focus 2b gets smaller as well. Generally, to achieve the desired FWHM and length of the line focus 2b for a given system, it is possible to calculate A and M such that:

M/A=FWHM2/FWHM0  Eq. 6.3; and
M2/A=Length2/Length0  Eq. (6.4).


Accordingly, the optical elements of the first lens element 5, the second lens element 11, and the axicon 10 may be exchanged to achieve the desired diameter and length for the line focus 2b. In some embodiments, these optical elements are physically removed from the optical assembly 6′ and replaced by others having the desired optical properties. However, this may require realignment of the optical assembly 6′ when switching to another configuration. In some embodiments, a plurality of optical elements is provided on a rotary wheel (similar to a filter wheel) or a slider to selectively choose the desired optical element that is in the beam path. For example, if the axicon is chosen as the removable/adjustable element, multiple axicons may be fabricated on a single substrate. Referring now to FIG. 6D, an axicon assembly 600 comprising a plurality of individual axicons 10A-10D having different angles in a single substrate is schematically illustrated. Any number of axicons may be provided. A desired individual axicon 10A-10D may be translated into an optical path of the laser beam 2 either manually or by motorized control.


As an example and not a limitation, diamond turning may be used to form the plurality of individual axicons 10A-10D in a transmissive material. Diamond turning allows very high precision (˜1 μm) features to be fabricated, in particular of the optical surfaces with respect to the outside features of a physical part that are referenced mechanically for alignment. The substrate may have a rectangular shape, and thus can be translated laterally to select a different axicon. For the wavelengths used in these laser cutting systems (commonly 1064 nm), ZnSe is an appropriate transmissive optical material which is compatible with diamond turning. Also, since diamond turning has an extremely high degree of precision to place objects relative to one other, the substrate could include mechanical repositioning features such as grooves or conical holes. It should be understood that similar lens element assemblies may be fabricated and utilized to select the various first and lens elements having different focal lengths (i.e., a first lens assembly and/or a second lens assembly).


In some embodiments, the input laser beam 2 is magnified by a factor N in the optical path prior to the axicon 10, as shown in the optical assembly 6″ illustrated in FIG. 6E. The optical assembly 6″ illustrated in FIG. 6E comprises an axicon 10, a first lens element 5, and a second lens element 11, similar to the embodiment depicted in FIG. 6C. In the example optical assembly 6″ illustrated in FIG. 6E, a telescope assembly comprising a third lens element 13 having a third focal length and a fourth lens element 15 having a fourth focal length is provided. As indicated above with respect to FIG. 6C, the focal lengths of the third lens element 13 and the fourth lens element 15 are adjustable, such as by exchanging lens elements.


By magnifying the laser beam 2, per Eqs. (4.3) and (4.5), the only parameter that is affected is the length of the line focus 2b—the diameter remains unchanged. The telescope positioned prior to the axicon 10, therefore, allows changes of only the length of the line focus 2b while leaving the diameter unchanged.


Interchanging optical elements, such as the first through fourth lenses, may not be desirable for a laser cutting system that operates in an industrial environment. In some embodiments, the third and fourth lens elements 13, 15 providing the magnification factor N and/or the first and second lens elements 5, 11 may instead be configured as one or more variable zoom assemblies. Such variable zoom assemblies may allow for continuous adjustment of the laser beam focal line length, as opposed to discrete steps available by interchanging axicons or lens elements. Such variable zoom assemblies may be actuated either manually or by motorization, where the latter allows programmatic adjustment of the system, which may be compatible with manufacturing requirements.


Another optical assembly 4 for separating a material using a laser beam line focus 2b is schematically depicted in FIG. 6F. Generally, the example optical assembly 4 utilizes a reflective axicon 19 and a ring-shaped reflection assembly 18 with an angled reflective surface having the same angle as the reflective axicon 19. A first lens element 17 converges (or, diverges) the laser beam 2 prior to the reflective axicon 19. The reflective axicon 19 and the ring-shaped reflection assembly 18 create a ring of collimated light. A second lens element 11 focuses the circular radiation SR to generate the laser beam line focus 2b. The radius of the circular radiation h may be continuously varied by translating the reflective axicon 19 with respect to the ring-shaped reflection assembly 18 (or vice versa) as indicated by arrow A. Because the focal length of the second lens element 11 focuses the rays at approximately a distance F2 from the second lens element 11, this change in ring radius will in turn change the final aperture angle β, yielding a change in the length of the laser beam line focus 2b, per Eq. (4.5). Larger rain radii h, created by moving the reflective axicon 19 to the right, will yield smaller focal line lengths. However, the diameter of the laser beam focal line 2b will also change, per Eq. (4.3). Larger ring radii h will yield smaller focal line diameters.



FIG. 6G schematically illustrates another optical assembly 4′ for creating a continuously adjustable collimated ring of light SR. The example optical assembly 4′ comprises a first lens element 17 prior to a first transmissive axicon 20, a second transmissive axicon 21, and a second lens element 11 prior to the second transmissive axicon 21. The first lens element 17 creates a small convergence (or divergence in some embodiments) of the laser beam 2 which creates a spherical aberration in the system to make a line focus.


The laser beam 2 exits the first transmissive axicon 20 at its angled emergence surface. The second transmissive axicon 21 receives the laser beam at its angled entrance surface and creates a ring of collimated light SR. The angle of deflection of the first transmissive axicon 20 is substantially equal to the angle of deflection of the second transmissive axicon 21. A second lens element 11 then focuses the light to generate the laser beam line focus 2b. Adjusting the ring radii h may be achieved by varying the adjustable distance D between the first and second transmissive axicons 20, 21. This movement adjusts the length and diameter of the laser beam line focus 2b.


Note that, as shown in FIG. 7, the typical operation of such a picosecond laser creates a “burst” 710 of pulses 720. Each “burst” 710 may contain multiple pulses 720 (such as two pulses, three pulses as shown in FIG. 7, four pulses, five pulses, 10 pulses, 15 pulses, 20 pulses, 25 pulses or more) of very short duration (˜10 psec). Each pulse 720 (also referred to as a sub-pulse herein) is separated in time by a duration in a range of between about 1 nsec and about 50 nsec, for example, 10 to 30 nsec, such as approximately 20 nsec (50 MHz), with the time often governed by the laser cavity design. The time between each “burst” 710 will be much longer, often about 10 μsec, for a laser repetition rate of about 100 kHz. In some embodiments the burst repetition frequency is in a range of between about 1 kHz and about 200 kHz. The exact timings, pulse durations, and repetition rates can vary depending on the laser design, but short pulses (i.e., less than about 15 psec) of high intensity have been shown to work well with this technique. (Bursting or producing pulse bursts is a type of laser operation where the emission of pulses is not in a uniform and steady stream but rather in tight clusters of pulses.)


The average laser power per burst measured at the material can be greater than 40 microJoules per mm thickness of material, for example between 40 microJoules/mm and 2500 microJoules/mm, or between 500 and 2250 microJoules/mm. For example, for 0.1 mm-0.2 mm thick Corning Eagle XG® glass one may use 200 μJ pulse bursts, which gives an exemplary range of 1000-2000 μJ/mm. For example, for 0.5-0.7 mm thick Corning Eagle XG® glass, one may use 400-700 μJ pulse bursts to perforate glass, which corresponds to an exemplary example, for the purpose of perforating some alkaline earth boro-aluminosilicate glass compositions a picosecond pulsed laser (e.g., a 1064 nm, or 532 nm picosecond pulsed laser) which produces bursts of multiple pulses in combination with line-focus beam forming optics may be used to create lines of damage (defect lines) in the glass composition. In one embodiment, a glass composition with up to 0.7 mm thickness was positioned so that it was within the region of the focal line produced by the optics. With a focal line about 1 mm in length, and a 1064 nm picosecond laser that produces output power of about 24 W or more at a burst repetition rate of 200 kHz (about 120 microJoules/burst) measured at the glass, the optical intensities in the focal line region are high enough to create non-linear absorption in the glass. The pulsed laser beam can have an average laser burst energy measured, at the material, greater than 40 microJoules per mm thickness of material. The average laser burst energy used can be as high as 2500 μJ per mm thickness of transparent material, for example 40-2500 μJ/mm, with 500-2250 μJ/mm being preferable, and 550 to 2100 μJ/mm being even more preferable because the energy density is strong enough to make a thorough damage track through the glass, while minimizing the extent of micro cracking orthogonal to the perforated line or cut edge. In some exemplary embodiments the laser burst energy is 40-1000 μJ/mm. This “average pulse burst laser energy” per mm can also be referred to as an average, per-burst, linear energy density, or an average energy per laser pulse burst per mm thickness of material. A region of damaged, vaporized, or otherwise modified material within the glass composition was created that approximately followed the linear region of high optical intensity created by the laser beam focal line.



FIG. 8 shows the contrast between a focused Gaussian beam and a Bessel beam incident upon a glass-air-glass composite structure. A focused Gaussian beam will diverge upon entering the first glass layer and will not drill to large depths, or if self-focusing occurs as the glass is drilled, the beam will emerge from the first glass layer and diffract, and will not drill into the second glass layer. In contrast, a Bessel beam will drill (and more specifically damage, perforate, or cut) both glass layers over the full extent of the line focus. An example of a glass-air-glass composite structure cut with a Bessel beam is shown in the inset photograph in FIG. 8, which shows a side view of the exposed cut edges. The top and bottom glass pieces are 0.4 mm thick 2320, CT101. The exemplary air gap between two layers of glass is about 400 μm. The cut was made with a single pass of the laser at 200 mm/sec, so that the two pieces of glass were cut simultaneously, even though they were separated by >400 μm.


In some of the embodiments described herein, the air gap is between 50 μm and 5 mm, for example is between 50 μm and 2 mm, or between 200 μm and 2 mm.


Exemplary disruption layers include polyethylene plastic sheeting (e.g., Visqueen). Transparent layers, as shown in FIG. 9, include transparent vinyl (e.g., Penstick). Note that unlike with other focused laser methods, to get the effect of a blocking or stop layer, the exact focus does not need to be precisely controlled, nor does the material of the disruption layer need to be particularly durable or expensive. In many applications, one just needs a layer that interferes with the laser light slightly to disrupt the laser light and prevent line focus from occurring. The fact that Visqueen prevents cutting with the picosecond laser and line focus is a perfect example—other focused picosecond laser beams will most certainly drill right through the Visqueen, and one wishing to avoid drilling right through such a material with other laser methods one would have to very precisely set the laser focus to not be near the Visqueen.



FIG. 10 shows stacking with transparent protective layers to cut multiple sheets while reducing abrasion or contamination. Simultaneously cutting a stack of display glass sheets is very advantageous. A transparent polymer such as vinyl can be placed between the glass sheets. The transparent polymer layers serve as protective layers serve to reduce damage to the glass surfaces which are in close contact with one another. These layers would allow the cutting process to work, but would protect the glass sheets from scratching one another, and would furthermore prevent any cutting debris (albeit it is small with this process) from contaminating the glass surfaces. The protective layers can also be comprised of evaporated dielectric layers deposited on the substrates or glass sheets.



FIG. 11 shows air gap and cutting of encapsulated devices. This line focus process can simultaneously cut through stacked glass sheets, even if a significant macroscopic air gap is present. This is not possible with other laser methods, as illustrated in FIG. 8. Many devices require glass encapsulation, such as OLEDs (organic light emitting diode). Being able to cut through the two glass layers simultaneously is very advantageous for a reliable and efficient device segmentation process. Segmented means one component can be separated from a larger sheet of material that may contain a plurality of other components. Other components that can be segmented, cut out, or produced by the methods described herein are, for example, OLED (organic light emitting diode) components, DLP (digital light processor) components, an LCD (liquid crystal display) cells, semiconductor device substrates.



FIG. 12 shows cutting an article such as electrochromic glass coated with transparent conductive layers (e.g. ITO). Cutting glass that already has transparent conducting layers such as indium tin oxide (ITO) is of high value for electrochromic glass applications and also touch panel devices. This laser process can cut through such layers with minimal damage to the transparent conductive layer and very little debris generation. The extremely small size of the perforated holes (<5 um) means that very little of the ITO will be affected by the cutting process, whereas other cutting methods are going to generate far more surface damage and debris.



FIG. 13 shows precision cutting of some layers in a stack while not damaging others, as also shown in FIG. 1, extending the concept to multiple layers (i.e., more than two layers). In the embodiment of FIG. 13, the disruption element is a defocusing layer.


Other Examples

In general, the higher the available laser power, the faster the material can be cut with the above process. Processes disclosed herein can cut glass at a cutting speed of 0.25 m/sec, or faster. A cut speed (or cutting speed) is the rate the laser beam moves relative to the surface of the transparent material (e.g., glass) while creating multiple holes or modified regions.) High cut speeds, such as, for example 400 mm/sec, 500 mm/sec, 750 mm/sec, 1 m/sec, 1.2 m/sec, 1.5 m/sec, or 2 m/sec, or even 3.4 m/sec, 5 m/sec, 5 m/sec, 7 m/sec, or 10 m/sec are often desired in order to minimize capital investment for manufacturing, and to optimize equipment utilization rate. The laser power is equal to the burst energy multiplied by the burst repetition frequency (rate) of the laser. In general, to cut such glass materials at high cutting speeds, the damage tracks are typically spaced apart by 1-25 microns, in some embodiments the spacing is preferably 3 microns or larger—for example 3-12 microns, or for example 5-10 microns, or 10-20 microns.


For example, to achieve a linear cutting speed of 300 mm/sec, 3 micron hole pitch corresponds to a pulse burst laser with at least 100 kHz burst repetition rate. For a 600 mm/sec cutting speed, a 3 micron pitch corresponds to a burst-pulsed laser with at least 200 kHz burst repetition rate. A pulse burst laser that produces at least 40 μJ/burst at 200 kHz, and cuts at a 600 mm/s cutting speed needs to have laser power of at least 8 Watts. Higher cut speeds therefore require even higher laser powers.


For example a 0.4 m/sec cut speed at 3 μm pitch and 40 μJ/burst would require at least a 5 Watt laser, a 0.5 m/sec cut speed at 3 μm pitch and 40 μJ/burst would require at least a 6 Watt laser. Thus, preferably the laser power of the pulse burst ps laser is 6 watts or higher, more preferably at least 8 Watts or higher, and even more preferably at least 10 W or higher. For example in order to achieve a 0.4 m/sec cut speed at 4 μm pitch (defect lines pacing, or between damage tracks spacing) and 100 μJ/burst one would require at least a 10 Watt laser, and to achieve a 0.5 m/sec cut speed at 4 μm pitch and 100 μJ/burst one would require at least a 12 Watt laser. For example, to achieve a cut speed of 1 m/sec at 3 μm pitch and 40 μJ/burst one would require at least a 13 Watt laser. Also for example 1 m/sec cut speed at 4 μm pitch and 400 μJ/burst would require at least a 100 Watt laser. The optimal pitch between damage tracks and the exact burst energy is material dependent, and can be determined empirically. However, it should be noted that raising the laser pulse energy or making the damage tracks at a closer pitch are not conditions that always make the substrate material separate better or with improved edge quality. Too dense a pitch (for example <0.1 micron, in some exemplary embodiments <1 μm, or in some embodiments <2 μm) between damage tracks can sometimes inhibit the formation of nearby subsequent damage tracks, and often can inhibit the separation of the material around the perforated contour, and may also result in increased unwanted micro cracking within the glass. Too long a pitch (>50 μm, and in some glasses >25 μm) may result in “uncontrolled microcracking”—i.e., where instead of propagating from hole to hole the microcracks propagate along a different path, and cause the glass to crack in a different (undesirable) direction. This may ultimately lower the strength of the separated glass part, since the residual microcracks will acts as flaws which weaken the glass. Too high a burst energy (e.g., >2500 μJ/burst, and in some embodiments >500 μJ/burst) used to form each damage track can cause “healing” or re-melting of already formed microcracks of adjacent damage tracks, which will inhibit separation of the glass. Accordingly, it is preferred that burst energy be <2500 μJ/burst, for example, ≤500 μJ/burst. Also, using a burst energy that is too high can cause formation of microcracks that are extremely large and create flaws which reduce the edge strength of the parts after separation. Too low a burst energy (<40 μJ/burst) may result in no appreciable damage track formed within the glass, and hence very high separation strength or complete inability to separate along the perforated contour.


Typical exemplary cutting rates (speeds) enabled by this process are, for example, 0.25 m/sec and higher. In some embodiments the cutting rates are at least 300 mm/sec. In some embodiments described herein the cutting rates are at least 400 mm/sec, for example 500 mm/sec to 2000 mm/sec, or higher. In some embodiments the picosecond (ps) laser utilizes pulse bursts to produce defect lines with periodicity between 0.5 microns and 13 microns, e.g. 0.5 and 3 microns. In some embodiments the pulsed laser has laser power of 10 W-100 W and the material and/or the laser beam are translated relative to one another at a rate of at least 0.25 m/sec, for example at the rate of 0.25 to 0.35 m/sec, or 0.4 m/sec to 5 m/sec. Preferably, each pulse burst of the pulsed laser beam has an average laser energy measured at the workpiece greater than 40 microJoules per burst mm thickness of workpiece. Preferably, each pulse burst of the pulsed laser beam has an average laser energy measured at the workpiece greater of less than 2500 microJoules per burst per mm thickness of workpiece, and preferably lass than about 2000 microJoules per burst per mm, and in some embodiments less than 1500 microJoules per burst per mm thickness of workpiece, for example not more than 500 microJoules per burst per mm thickness of workpiece.


It has been discovered that much higher (5 to 10 times higher) volumetric pulse energy density (μj/μm3) is required for perforating alkaline earth boro-aluminosilicate glasses with low or no alkali containing glasses as compared to that for glasses such as Corning Gorilla®. This can be achieved, for example, by utilizing pulse burst lasers, preferably with at least 2 pulses per burst and providing volumetric energy densities within the alkaline earth boro-aluminosilicate glasses (with low or no alkali) of about 0.05 μJ/μm3 or higher, e.g., at least 0.1 μJ/μm3, for example 0.1-0.5 μJ/μm3.


Accordingly, it is preferable that the laser produces pulse bursts with at least 2 pulses per burst. For example, in some embodiments the pulsed laser has laser power of 10 W-150 W (e.g., 10-100 W) and produces pulse bursts with at least 2 pulses per burst (e.g., 2-25 pulses per burst). In some embodiments the pulsed laser has the power of 25 W-60 W, and produces pulse bursts with at least 2-25 pulses per burst, and periodicity or distance between the adjacent defect lines produced by the laser bursts is 2-10 microns. In some embodiments the pulsed laser has laser power of 10 W-100 W, produces pulse bursts with at least 2 pulses per burst, and the workpiece and the laser beam are translated relative to one another at a rate of at least 0.25 m/sec. In some embodiments the workpiece and/or the laser beam are translated relative to one another at a rate of at least 0.4 m/sec.


For example, for cutting 0.7 mm thick non-ion exchanged Corning code 2319 or code 2320 Gorilla glass, it is observed that pitches of 3-7 microns can work well, with pulse burst energies of about 150-250 μJ/burst, and burst pulse numbers that range from 2-15, and preferably with pitches of 3-5 microns and burst pulse numbers (number of pulses per burst) of 2-5.


At 1 m/sec cut speeds, the cutting of Eagle XG® glass typically requires utilization of laser powers of 15-84 Watts, with 30-45 Watts often being sufficient. In general, across a variety of glass and other transparent materials, applicants discovered that laser powers between 10 and 100 W are preferred to achieve cutting speeds from 0.2-1 m/sec, with laser powers of 25-60 Watts being sufficient (and optimum) for many glasses. For cutting speeds of 0.4 m to 5 m/sec, laser powers should preferably be 10 W-150 W, with burst energy of 40-750 μJ/burst, 2-25 bursts per pulse (depending on the material that is cut), and hole separation (or pitch) of 3 to 15 μm, or 3-10 μm. The use of picosecond pulse burst lasers would be preferable for these cutting speeds because they generate high power and the required number of pulses per burst. Thus, according to some exemplary embodiments, the pulsed laser produces 10-100 W of power, for example 25 W to 60 Watts, and produces pulse bursts at least 2-25 pulses per burst and the distance between the defect lines is 2-15 microns; and the laser beam and/or workpiece are translated relative to one another at a rate of at least 0.25 m/sec, in some embodiments at least 0.4 m/sec, for example 0.5 m/sec to 5 m/sec, or faster.


It should now be understood that embodiments described herein provide for systems and methods for separating substrates, such as glass substrates, by application of a laser beam focal line. The systems described herein allow for fast adjustment of a length and/or diameter of the laser beam focal line to account for different types of material as well as different thicknesses of material.


While exemplary embodiments have been described herein, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope encompassed by the appended claims.

Claims
  • 1. A system for processing a transparent material, the system comprising: a laser source operable to emit a pulsed laser beam; andan optical assembly comprising an axicon disposed within an optical path of the pulsed laser beam and configured to transform the pulsed laser beam into a non-diffracting laser beam having a non-diffracting laser beam focal line having an adjustable length and an adjustable diameter, wherein the axicon is a reflective axicon positioned within the optical path of the pulsed laser beam;a ring-shaped reflection assembly axially separated from the reflective axicon by an adjustable distance D, the ring-shaped reflection assembly comprising an angled reflective surface, wherein the pulsed laser beam is reflected by the reflective axicon toward the angled reflective surface, and the pulsed laser beam is then reflected by the angled reflective surface; anda lens element positioned within the optical path of the pulsed laser beam following the ring-shaped reflection assembly, wherein the lens element focuses the pulsed laser beam to form the non-diffracting laser beam focal line;wherein the pulsed laser beam is converging or diverging prior to the reflective axicon,wherein at least a portion of the non-diffracting laser beam focal line is operable to be positioned within a bulk of the transparent material, such that the non-diffracting laser beam focal line generates an induced multi-photon absorption within the transparent material, the multi-photo induced absorption producing a material modification within the transparent material along the non-diffracting laser beam focal line.
  • 2. The system of claim 1, wherein the axicon is transmissive, and the optical assembly further comprises a variable zoom assembly positioned in the optical path of the pulsed laser beam between the axicon and the transparent material.
  • 3. The system of claim 1, wherein: the axicon comprises an entrance surface and an emergence surface;the emergence surface has an angle with respect to the entrance surface; andthe adjustable length and the adjustable diameter of the non-diffracting laser beam focal line is adjusted by varying the angle of the emergence surface of the axicon.
  • 4. The system of claim 3, wherein: the optical assembly further comprises an axicon assembly comprising a plurality of axicons, each individual axicon comprising a different angle on the emergence surface; andthe angle of the emergence surface of the axicon is varied by selectively positioning a desired individual axicon of the plurality of axicons within the optical path of the pulsed laser beam.
  • 5. The system of claim 4, wherein: the optical assembly further comprises a first lens element having a first focal length, and a second lens element having a second focal length;the first lens element and the second lens element are disposed within the optical path of pulsed laser beam after the axicon such that the first lens element is positioned between the axicon and the second lens element; andthe adjustable length and the adjustable diameter of the non-diffracting laser beam focal line is further adjusted by varying the first focal length and/or the second focal length.
  • 6. The system of claim 1, wherein: the optical assembly further comprises a third lens having a third focal length, and a fourth lens having a fourth focal length; andat least one of the third focal length and the fourth focal length are adjustable to adjust the diameter of the pulsed laser beam at the entrance surface of the axicon.
  • 7. The system of claim 1, wherein the optical assembly further comprises a variable zoom assembly operable to adjust the diameter of the pulsed laser beam at the entrance surface of the axicon.
  • 8. The system of claim 1, wherein the adjustable diameter of the non-diffracting laser beam focal line or the adjustable length of the non-diffracting laser beam focal line is adjusted by varying the adjustable distance D.
  • 9. The system of claim 1, wherein: the optical assembly further comprises a second lens element positioned in the optical path of the pulsed laser beam prior to the reflective axicon;the second lens element causes the pulsed laser beam to converge or diverge prior to the reflective axicon; andadjusting a focal length of the second lens element adjusts the adjustable length and the adjustable diameter of the non-diffracting laser beam focal line.
CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 371 of International Application No. PCT/US2015/40259, filed on Jul. 14, 2015, which claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Ser. No. 62/024,122 filed on Jul. 14, 2014 the content of which is relied upon and incorporated herein by reference in its entirety.

PCT Information
Filing Document Filing Date Country Kind
PCT/US2015/040259 7/14/2015 WO
Publishing Document Publishing Date Country Kind
WO2016/010954 1/21/2016 WO A
US Referenced Citations (582)
Number Name Date Kind
1529243 Drake et al. Mar 1925 A
1626396 Drake Apr 1927 A
1790397 Woods et al. Jan 1931 A
2682134 Stookey Jun 1954 A
2749794 O'Leary Jun 1956 A
2754956 Sommer Jul 1956 A
3647410 Heaton Mar 1972 A
3673900 Jendrisak et al. Jul 1972 A
3695497 Dear Oct 1972 A
3695498 Dear Oct 1972 A
3729302 Heaton Apr 1973 A
3775084 Heaton Nov 1973 A
3947093 Goshima et al. Mar 1976 A
4076159 Farragher Feb 1978 A
4226607 Domken Oct 1980 A
4441008 Chan Apr 1984 A
4546231 Gresser Oct 1985 A
4618056 Cutshall Oct 1986 A
4623776 Buchroeder Nov 1986 A
4642439 Miller Feb 1987 A
4646308 Kafka Feb 1987 A
4764930 Bille Aug 1988 A
4891054 Bricker Jan 1990 A
4907586 Bille Mar 1990 A
4918751 Pessot Apr 1990 A
4929065 Hagerty May 1990 A
4951457 Deal Aug 1990 A
4997250 Ortiz, Jr. Mar 1991 A
5035918 Vyas Jul 1991 A
5040182 Spinelli Aug 1991 A
5104210 Tokas Apr 1992 A
5104523 Masaharu et al. Apr 1992 A
5108857 Kitayama Apr 1992 A
5112722 Tsujino May 1992 A
5114834 Nachshon May 1992 A
5221034 Bando Jun 1993 A
5256853 McIntyre Oct 1993 A
5265107 Delfyett, Jr. Nov 1993 A
5326956 Lunney Jul 1994 A
5400350 Galvanauskas Mar 1995 A
5410567 Brundage et al. Apr 1995 A
5418803 Zhiglinsky et al. May 1995 A
5434875 Rieger Jul 1995 A
5436925 Lin Jul 1995 A
5475197 Wrobel Dec 1995 A
5521352 Lawson May 1996 A
5541774 Blankenbecler Jul 1996 A
5553093 Ramaswamy Sep 1996 A
5574597 Kataoka Nov 1996 A
5578229 Barnekov et al. Nov 1996 A
5586138 Yokoyama Dec 1996 A
5656186 Mourou Aug 1997 A
5676866 in den Baumen Oct 1997 A
5684642 Zumoto Nov 1997 A
5692703 Murphy et al. Dec 1997 A
5696782 Harter Dec 1997 A
5715346 Liu Feb 1998 A
5736061 Fukada et al. Apr 1998 A
5736709 Neiheisel Apr 1998 A
5776220 Allaire Jul 1998 A
5781684 Liu Jul 1998 A
5796112 Ichie Aug 1998 A
5854490 Ooaeh et al. Dec 1998 A
5854751 Di et al. Dec 1998 A
5878866 Lisec Mar 1999 A
5968441 Seki Oct 1999 A
6003418 Bezama et al. Dec 1999 A
6016223 Suzuki Jan 2000 A
6016324 Rieger Jan 2000 A
6033583 Musket Mar 2000 A
6038055 Hansch Mar 2000 A
6055829 Witzmann May 2000 A
6078599 Everage Jun 2000 A
6137632 Bernacki Oct 2000 A
6156030 Neev Dec 2000 A
6160835 Kwon Dec 2000 A
6185051 Chen Feb 2001 B1
6186384 Sawada Feb 2001 B1
6191880 Schuster Feb 2001 B1
6210401 Lai Apr 2001 B1
6256328 Delfyett Jul 2001 B1
6259058 Hoekstra Jul 2001 B1
6259151 Morrison Jul 2001 B1
6259512 Mizouchi Jul 2001 B1
6272156 Reed Aug 2001 B1
6301932 Allen Oct 2001 B1
6308055 Welland et al. Oct 2001 B1
6322958 Hayashi Nov 2001 B1
6339208 Rockstroh Jan 2002 B1
6373565 Kafka Apr 2002 B1
6381391 Islam Apr 2002 B1
6396856 Sucha May 2002 B1
6407360 Choo Jun 2002 B1
6438996 Cuvelier Aug 2002 B1
6445491 Sucha Sep 2002 B2
6449301 Wu Sep 2002 B1
6461223 Bando Oct 2002 B1
6484052 Visuri Nov 2002 B1
6489589 Alexander Dec 2002 B1
6501576 Seacombe Dec 2002 B1
6501578 Bernstein Dec 2002 B1
6520057 Steadman Feb 2003 B1
6552301 Herman Apr 2003 B2
6573026 Aitken Jun 2003 B1
6592703 Habeck Jul 2003 B1
6635849 Okawa Oct 2003 B1
6635850 Amako Oct 2003 B2
6720519 Liu Apr 2004 B2
6729151 Thompson May 2004 B1
6729161 Miura May 2004 B1
6737345 Lin et al. May 2004 B1
6744009 Xuan Jun 2004 B1
6787732 Xuan Sep 2004 B1
6791935 Hatano Sep 2004 B2
6800237 Yamamoto Oct 2004 B1
6800831 Hoetzel Oct 2004 B1
6856379 Schuster Feb 2005 B2
6885502 Schuster Apr 2005 B2
6958094 Ohmi Oct 2005 B2
6992026 Fukuyo Jan 2006 B2
7009138 Amako Mar 2006 B2
7061583 Mulkens et al. Jun 2006 B2
7102118 Acker Sep 2006 B2
7196841 Melzer Mar 2007 B2
7259354 Pailthorp et al. Aug 2007 B2
7353829 Wachter Apr 2008 B1
7402773 Nomaru Jul 2008 B2
7408616 Gruner Aug 2008 B2
7408622 Fiolka Aug 2008 B2
7511886 Schultz Mar 2009 B2
7535634 Savchenkov May 2009 B1
7633033 Thomas Dec 2009 B2
7642483 You Jan 2010 B2
7649153 Haight Jan 2010 B2
7726532 Gonoe Jun 2010 B2
7794904 Brueck Sep 2010 B2
7800734 Komatsuda Sep 2010 B2
7901967 Komura et al. Mar 2011 B2
7920337 Perchak Apr 2011 B2
7978408 Sawabe Jul 2011 B2
8035803 Fiolka Oct 2011 B2
8035882 Fanton et al. Oct 2011 B2
8035901 Abramov Oct 2011 B2
8068279 Schuster Nov 2011 B2
8104385 Hayashi Jan 2012 B2
8118971 Hori Feb 2012 B2
8123515 Schleelein Feb 2012 B2
8132427 Brown Mar 2012 B2
8144308 Muramatsu Mar 2012 B2
8158514 Krueger et al. Apr 2012 B2
8164818 Collins et al. Apr 2012 B2
8168514 Garner May 2012 B2
8194170 Golub Jun 2012 B2
8211259 Sato et al. Jul 2012 B2
8237918 Totzeck Aug 2012 B2
8245539 Lu Aug 2012 B2
8245540 Abramov Aug 2012 B2
8248600 Matousek Aug 2012 B2
8259393 Fiolka Sep 2012 B2
8269138 Garner Sep 2012 B2
8279524 Fiolka Oct 2012 B2
8283595 Fukuyo Oct 2012 B2
8283695 Salcedo et al. Oct 2012 B2
8292141 Cox Oct 2012 B2
8296066 Zhao Oct 2012 B2
8327666 Harvey Dec 2012 B2
8339578 Omura Dec 2012 B2
8341976 Dejneka Jan 2013 B2
8347551 Van Der Drift Jan 2013 B2
8347651 Abramov Jan 2013 B2
8358868 Iketani Jan 2013 B2
8358888 Ramachandran Jan 2013 B2
8379188 Mueller Feb 2013 B2
8444905 Li et al. May 2013 B2
8444906 Lee May 2013 B2
8448471 Kumatani May 2013 B2
8475507 Dewey Jul 2013 B2
8482717 Fiolka Jul 2013 B2
8491983 Ono et al. Jul 2013 B2
8518280 Hsu Aug 2013 B2
8549881 Brown Oct 2013 B2
8584354 Cornejo Nov 2013 B2
8584490 Garner Nov 2013 B2
8592716 Abramov Nov 2013 B2
8604380 Howerton Dec 2013 B2
8607590 Glaesemann Dec 2013 B2
8616024 Cornejo Dec 2013 B2
8635857 Crosbie Jan 2014 B2
8635887 Black Jan 2014 B2
8680489 Martinez Mar 2014 B2
8685838 Fukuyo Apr 2014 B2
8697228 Carre Apr 2014 B2
8720228 Li May 2014 B2
8826696 Brown et al. Sep 2014 B2
8847112 Panarello et al. Sep 2014 B2
8852698 Fukumitsu Oct 2014 B2
8887529 Lu Nov 2014 B2
8916798 Pluss Dec 2014 B2
8943855 Gomez Feb 2015 B2
8951889 Ryu et al. Feb 2015 B2
8971053 Kariya Mar 2015 B2
9028613 Kim et al. May 2015 B2
9052605 Van Ingen Schenau Jun 2015 B2
9086509 Knutson Jul 2015 B2
9138913 Arai Sep 2015 B2
9170500 Van Schoot Oct 2015 B2
9227868 Matsumoto Jan 2016 B2
9290407 Barefoot et al. Mar 2016 B2
9296066 Hosseini Mar 2016 B2
9324791 Tamemoto Apr 2016 B2
9327381 Lee May 2016 B2
9341912 Shrivastava et al. May 2016 B2
9346706 Bazemore et al. May 2016 B2
9446590 Chen Sep 2016 B2
9481598 Bergh Nov 2016 B2
9499343 Cornelissen et al. Nov 2016 B2
9517929 Hosseini Dec 2016 B2
9517963 Marjanovic et al. Dec 2016 B2
9701581 Kangastupa et al. Jul 2017 B2
9703167 Parker et al. Jul 2017 B2
9815730 Marjanovic et al. Nov 2017 B2
9850160 Marjanovic et al. Dec 2017 B2
9873628 Haloui et al. Jan 2018 B1
9878304 Kotake et al. Jan 2018 B2
10190363 Behmke et al. Jan 2019 B2
10730783 Akarapu et al. Aug 2020 B2
20010019404 Schuster Sep 2001 A1
20010027842 Curcio et al. Oct 2001 A1
20020006765 Michel et al. Jan 2002 A1
20020046997 Nam Apr 2002 A1
20020082466 Han Jun 2002 A1
20020097486 Yamaguchi Jul 2002 A1
20020097488 Hay et al. Jul 2002 A1
20020110639 Bruns Aug 2002 A1
20020126380 Schuster Sep 2002 A1
20020139786 Amako et al. Oct 2002 A1
20030006221 Hong Jan 2003 A1
20030007772 Borrelli et al. Jan 2003 A1
20030007773 Kondo Jan 2003 A1
20030038225 Mulder Feb 2003 A1
20030070706 Fujioka Apr 2003 A1
20030227663 Agrawal et al. Dec 2003 A1
20040021615 Benson et al. Feb 2004 A1
20040051982 Perchak Mar 2004 A1
20040108467 Eurlings Jun 2004 A1
20040144231 Hanada Jul 2004 A1
20040221615 Postupack Nov 2004 A1
20050024743 Camy-Peyret Feb 2005 A1
20050098458 Gruetzmacher et al. May 2005 A1
20050098548 Kobayashi May 2005 A1
20050115938 Sawaki Jun 2005 A1
20050116938 Ito et al. Jun 2005 A1
20050205778 Kitai et al. Sep 2005 A1
20050209898 Asai et al. Sep 2005 A1
20050231651 Myers Oct 2005 A1
20050274702 Deshi Dec 2005 A1
20050277270 Yoshikawa Dec 2005 A1
20060011593 Fukuyo Jan 2006 A1
20060021385 Cimo et al. Feb 2006 A1
20060028706 Totzeck Feb 2006 A1
20060028728 Li Feb 2006 A1
20060050261 Brotsack Mar 2006 A1
20060109874 Shiozaki May 2006 A1
20060118529 Aoki et al. Jun 2006 A1
20060127679 Gulati Jun 2006 A1
20060146384 Schultz Jul 2006 A1
20060151450 You et al. Jul 2006 A1
20060170617 Latypov Aug 2006 A1
20060213883 Eberhardt et al. Sep 2006 A1
20060227440 Gluckstad Oct 2006 A1
20060266744 Nomaru Nov 2006 A1
20060289410 Morita Dec 2006 A1
20060291835 Nozaki et al. Dec 2006 A1
20070021548 Hattori et al. Jan 2007 A1
20070030471 Troost Feb 2007 A1
20070044606 Kang et al. Mar 2007 A1
20070045253 Jordens et al. Mar 2007 A1
20070051706 Bovatsek et al. Mar 2007 A1
20070053632 Popp Mar 2007 A1
20070068648 Hu et al. Mar 2007 A1
20070090180 Griffis et al. Apr 2007 A1
20070091977 Sohn Apr 2007 A1
20070111119 Hu et al. May 2007 A1
20070111390 Komura May 2007 A1
20070111480 Maruyama May 2007 A1
20070119831 Kandt May 2007 A1
20070132977 Komatsuda Jun 2007 A1
20070138151 Tanaka Jun 2007 A1
20070177116 Amako Aug 2007 A1
20070202619 Tamura Aug 2007 A1
20070209029 Ivonin Sep 2007 A1
20070228616 Bang Oct 2007 A1
20070298529 Maeda Dec 2007 A1
20080000884 Sugiura Jan 2008 A1
20080050584 Noguchi et al. Feb 2008 A1
20080079940 Sezerman Apr 2008 A1
20080087629 Shimomura et al. Apr 2008 A1
20080099444 Misawa May 2008 A1
20080158529 Hansen Jul 2008 A1
20080165925 Singer Jul 2008 A1
20080190981 Okajima et al. Aug 2008 A1
20080239268 Mulder Oct 2008 A1
20080309902 Rosenbluth Dec 2008 A1
20080310465 Achtenhagen Dec 2008 A1
20080314879 Bruland et al. Dec 2008 A1
20080318028 Winstanley et al. Dec 2008 A1
20090013724 Koyo Jan 2009 A1
20090032510 Ando et al. Feb 2009 A1
20090033902 Mulder Feb 2009 A1
20090050661 Na et al. Feb 2009 A1
20090091731 Ossmann Apr 2009 A1
20090104721 Hirakata et al. Apr 2009 A1
20090157341 Cheung Jun 2009 A1
20090170286 Tsukamoto et al. Jul 2009 A1
20090176034 Ruuttu Jul 2009 A1
20090183764 Meyer Jul 2009 A1
20090184849 Nasiri et al. Jul 2009 A1
20090188543 Bann Jul 2009 A1
20090199694 Uh et al. Aug 2009 A1
20090212033 Beck et al. Aug 2009 A1
20090242528 Howerton Oct 2009 A1
20090250446 Sakamoto Oct 2009 A1
20090294419 Abramov Dec 2009 A1
20090294422 Lubatschowski Dec 2009 A1
20090323160 Egerton et al. Dec 2009 A1
20090323162 Fanton et al. Dec 2009 A1
20090324899 Feinstein Dec 2009 A1
20090324903 Rumsby Dec 2009 A1
20100020304 Soer et al. Jan 2010 A1
20100024865 Shah et al. Feb 2010 A1
20100025387 Arai Feb 2010 A1
20100029460 Shojiya Feb 2010 A1
20100032087 Takahashi Feb 2010 A1
20100038349 Ke et al. Feb 2010 A1
20100046761 Henn et al. Feb 2010 A1
20100086741 Bovatsek Apr 2010 A1
20100089631 Sakaguchi Apr 2010 A1
20100089682 Martini et al. Apr 2010 A1
20100089882 Tamura Apr 2010 A1
20100102042 Garner Apr 2010 A1
20100129603 Blick May 2010 A1
20100145620 Georgi et al. Jun 2010 A1
20100147813 Lei Jun 2010 A1
20100197116 Shah et al. Aug 2010 A1
20100206008 Harvey et al. Aug 2010 A1
20100252538 Zeygerman Oct 2010 A1
20100252540 Lei Oct 2010 A1
20100252959 Lei Oct 2010 A1
20100276505 Smith Nov 2010 A1
20100279067 Sabia Nov 2010 A1
20100287991 Brown Nov 2010 A1
20100291353 Dejneka et al. Nov 2010 A1
20100320179 Morita et al. Dec 2010 A1
20100326138 Kumatani Dec 2010 A1
20100332087 Claffee et al. Dec 2010 A1
20110017716 Rumsby Jan 2011 A1
20110023298 Chujo et al. Feb 2011 A1
20110037149 Fukuyo et al. Feb 2011 A1
20110049764 Lee Mar 2011 A1
20110049765 Li Mar 2011 A1
20110088324 Wessel Apr 2011 A1
20110094267 Aniolek et al. Apr 2011 A1
20110100401 Fiorentini May 2011 A1
20110111179 Blick et al. May 2011 A1
20110127244 Li Jun 2011 A1
20110127697 Milne Jun 2011 A1
20110132581 Moss Jun 2011 A1
20110132881 Liu Jun 2011 A1
20110136303 Lee Jun 2011 A1
20110139760 Shah Jun 2011 A1
20110143470 Lee Jun 2011 A1
20110177325 Tomamoto et al. Jul 2011 A1
20110183116 Hung Jul 2011 A1
20110191024 Deluca Aug 2011 A1
20110210105 Romashko Sep 2011 A1
20110238308 Miller et al. Sep 2011 A1
20110240476 Wang et al. Oct 2011 A1
20110240611 Sandstrom Oct 2011 A1
20110240617 Cheon et al. Oct 2011 A1
20110261429 Sbar et al. Oct 2011 A1
20110277507 Lu Nov 2011 A1
20110300691 Sakamoto et al. Dec 2011 A1
20110318555 Bookbinder Dec 2011 A1
20120017642 Teranishi Jan 2012 A1
20120026573 Collins et al. Feb 2012 A1
20120047951 Dannoux Mar 2012 A1
20120047956 Li Mar 2012 A1
20120047957 Dannoux et al. Mar 2012 A1
20120048604 Cornejo Mar 2012 A1
20120061440 Roell Mar 2012 A1
20120064306 Kang Mar 2012 A1
20120067858 Kangastupa Mar 2012 A1
20120103018 Lu May 2012 A1
20120106117 Sundaram et al. May 2012 A1
20120111310 Ryu et al. May 2012 A1
20120125588 Nam et al. May 2012 A1
20120131961 Dannoux et al. May 2012 A1
20120131962 Mitsugi May 2012 A1
20120135195 Glaesemann May 2012 A1
20120135607 Shimoi May 2012 A1
20120135608 Shimoi May 2012 A1
20120145331 Gomez Jun 2012 A1
20120147449 Bhatnagar et al. Jun 2012 A1
20120196071 Cornejo Aug 2012 A1
20120196454 Shah et al. Aug 2012 A1
20120205356 Pluess Aug 2012 A1
20120211923 Garner et al. Aug 2012 A1
20120214004 Hashimoto et al. Aug 2012 A1
20120216570 Abramov et al. Aug 2012 A1
20120229787 Van Schoot Sep 2012 A1
20120234049 Bolton Sep 2012 A1
20120234807 Sercel Sep 2012 A1
20120237731 Boegli et al. Sep 2012 A1
20120255935 Kakui Oct 2012 A1
20120262689 Van Ingen Schenau Oct 2012 A1
20120293784 Xalter Nov 2012 A1
20120297568 Spezzani Nov 2012 A1
20120299219 Shimoi Nov 2012 A1
20120302139 Darcangelo Nov 2012 A1
20120320458 Knutson Dec 2012 A1
20120324950 Dale et al. Dec 2012 A1
20130019637 Sol Jan 2013 A1
20130031879 Yoshikane et al. Feb 2013 A1
20130034688 Koike Feb 2013 A1
20130044371 Rupp Feb 2013 A1
20130047671 Kohli Feb 2013 A1
20130056450 Lissotschenko Mar 2013 A1
20130061636 Imai Mar 2013 A1
20130068736 Mielke Mar 2013 A1
20130075480 Yokogi Mar 2013 A1
20130078891 Lee et al. Mar 2013 A1
20130091897 Fujii Apr 2013 A1
20130122264 Fujii May 2013 A1
20130126573 Hosseini May 2013 A1
20130126751 Mizoguchi May 2013 A1
20130129947 Harvey May 2013 A1
20130133367 Abramov May 2013 A1
20130139708 Hotta Jun 2013 A1
20130143416 Norval Jun 2013 A1
20130149434 Oh Jun 2013 A1
20130149494 Koike Jun 2013 A1
20130167590 Teranishi Jul 2013 A1
20130171425 Wang et al. Jul 2013 A1
20130174607 Wootton Jul 2013 A1
20130174610 Teranishi Jul 2013 A1
20130177033 Muro et al. Jul 2013 A1
20130180285 Kariya Jul 2013 A1
20130180665 Gomez et al. Jul 2013 A2
20130189806 Hoshino Jul 2013 A1
20130192305 Black Aug 2013 A1
20130209731 Nattermann Aug 2013 A1
20130210245 Jackl Aug 2013 A1
20130216573 Trusheim et al. Aug 2013 A1
20130220982 Thomas Aug 2013 A1
20130221053 Zhang Aug 2013 A1
20130222877 Greer et al. Aug 2013 A1
20130224439 Zhang Aug 2013 A1
20130228918 Chen Sep 2013 A1
20130247615 Boek Sep 2013 A1
20130248504 Kusuda Sep 2013 A1
20130266757 Giron Oct 2013 A1
20130270240 Kondo Oct 2013 A1
20130280495 Matsumoto Oct 2013 A1
20130288010 Akarapu Oct 2013 A1
20130291598 Saito Nov 2013 A1
20130312460 Kunishi Nov 2013 A1
20130323469 Abramov Dec 2013 A1
20130334185 Nomaru Dec 2013 A1
20130340480 Nattermann Dec 2013 A1
20130344684 Bowden Dec 2013 A1
20140023087 Czompo Jan 2014 A1
20140027951 Srinivas Jan 2014 A1
20140034730 Lee Feb 2014 A1
20140042202 Lee Feb 2014 A1
20140047957 Wu Feb 2014 A1
20140076869 Lee et al. Mar 2014 A1
20140083986 Zhang et al. Mar 2014 A1
20140102146 Saito Apr 2014 A1
20140110040 Cok Apr 2014 A1
20140113797 Yamada Apr 2014 A1
20140133119 Kariya May 2014 A1
20140141192 Fernando et al. May 2014 A1
20140141217 Gulati May 2014 A1
20140147623 Shorey May 2014 A1
20140147624 Streltsov May 2014 A1
20140165652 Saito Jun 2014 A1
20140174131 Saito Jun 2014 A1
20140182125 Rozbicki et al. Jul 2014 A1
20140199519 Schillinger Jul 2014 A1
20140216108 Wiegel Aug 2014 A1
20140238962 Nawrodt et al. Aug 2014 A1
20140239034 Cleary et al. Aug 2014 A1
20140239552 Srinivas et al. Aug 2014 A1
20140290310 Green Oct 2014 A1
20140291122 Bando Oct 2014 A1
20140320947 Egerton Oct 2014 A1
20140333929 Sung Nov 2014 A1
20140339207 Sugiyama et al. Nov 2014 A1
20140340730 Bergh et al. Nov 2014 A1
20140352400 Barrilado et al. Dec 2014 A1
20140361463 DeSimone Dec 2014 A1
20150014891 Amatucci et al. Jan 2015 A1
20150034612 Hosseini Feb 2015 A1
20150038313 Hosseini Feb 2015 A1
20150044445 Garner et al. Feb 2015 A1
20150059986 Komatsu et al. Mar 2015 A1
20150060402 Burkett et al. Mar 2015 A1
20150075221 Kawaguchi Mar 2015 A1
20150075222 Mader Mar 2015 A1
20150110442 Zimmel Apr 2015 A1
20150118522 Hosseini Apr 2015 A1
20150121960 Hosseini May 2015 A1
20150122656 Hosseini May 2015 A1
20150136743 Hosseini May 2015 A1
20150140241 Hosseini May 2015 A1
20150140735 Hosseini May 2015 A1
20150151380 Hosseini Jun 2015 A1
20150158120 Courvoisier Jun 2015 A1
20150165396 Mattson et al. Jun 2015 A1
20150165548 Marjanovic Jun 2015 A1
20150165560 Hackert Jun 2015 A1
20150165561 Le et al. Jun 2015 A1
20150165562 Marjanovic Jun 2015 A1
20150165563 Manley Jun 2015 A1
20150166391 Marjanovic Jun 2015 A1
20150166393 Marjanovic Jun 2015 A1
20150166394 Marjanovic Jun 2015 A1
20150166395 Marjanovic Jun 2015 A1
20150166396 Marjanovic Jun 2015 A1
20150166397 Marjanovic Jun 2015 A1
20150183679 Saito Jul 2015 A1
20150209922 Yoshikawa Jul 2015 A1
20150232369 Marjanovic Aug 2015 A1
20150299018 Bhuyan Oct 2015 A1
20150311058 Antsiferov et al. Oct 2015 A1
20150350991 Sayadi et al. Dec 2015 A1
20150352671 Darzi Dec 2015 A1
20150360991 Grundmueller Dec 2015 A1
20150362817 Ierson et al. Dec 2015 A1
20150362818 Greer Dec 2015 A1
20150367442 Bovatsek Dec 2015 A1
20160008927 Grundmueller Jan 2016 A1
20160009066 Nieber Jan 2016 A1
20160009585 Bookbinder et al. Jan 2016 A1
20160016257 Hosseini Jan 2016 A1
20160023922 Addiego Jan 2016 A1
20160031737 Hoppe et al. Feb 2016 A1
20160031745 Ortner Feb 2016 A1
20160039044 Kawaguchi Feb 2016 A1
20160059359 Krueger et al. Mar 2016 A1
20160060156 Krueger Mar 2016 A1
20160097960 Dixit et al. Apr 2016 A1
20160138328 Behmke et al. May 2016 A1
20160152516 Bazemore et al. Jun 2016 A1
20160154284 Sano Jun 2016 A1
20160159679 West Jun 2016 A1
20160168396 Letocart et al. Jun 2016 A1
20160279895 Marjanovic Sep 2016 A1
20160280580 Bohme Sep 2016 A1
20160282521 Uchiyama et al. Sep 2016 A1
20160290791 Buono Oct 2016 A1
20160311717 Nieber et al. Oct 2016 A1
20160368100 Marjanovic et al. Dec 2016 A1
20170002601 Bergh et al. Jan 2017 A1
20170008791 Kim et al. Jan 2017 A1
20170052381 Huang et al. Feb 2017 A1
20170169847 Tamaki Jun 2017 A1
20170183168 Jia Jun 2017 A1
20170197868 Gupta et al. Jul 2017 A1
20170225996 Bookbinder et al. Aug 2017 A1
20170252859 Kumkar et al. Sep 2017 A1
20170355634 Thierry Dec 2017 A1
20170368638 Tayebati et al. Dec 2017 A1
20180029919 Schnitzler et al. Feb 2018 A1
20180029920 Marjanovic et al. Feb 2018 A1
20180062342 Comstock et al. Mar 2018 A1
20180118602 Hackert et al. May 2018 A1
20180133837 Greenberg et al. May 2018 A1
20180134606 Wagner et al. May 2018 A1
20180186677 Ito et al. Jul 2018 A1
20180186678 Boeker et al. Jul 2018 A1
20180297887 Spier et al. Oct 2018 A1
Foreign Referenced Citations (380)
Number Date Country
1259924 Jul 2000 CN
2388062 Jul 2000 CN
1473087 Feb 2004 CN
1517313 Aug 2004 CN
1573364 Feb 2005 CN
1619778 May 2005 CN
1735568 Feb 2006 CN
1283409 Nov 2006 CN
1890074 Jan 2007 CN
1920632 Feb 2007 CN
1930097 Mar 2007 CN
101031383 Sep 2007 CN
101043936 Sep 2007 CN
101048255 Oct 2007 CN
101386466 Mar 2009 CN
101502914 Aug 2009 CN
101595554 Dec 2009 CN
101610870 Dec 2009 CN
201357287 Dec 2009 CN
101622722 Jan 2010 CN
101637849 Feb 2010 CN
201471092 May 2010 CN
101862907 Oct 2010 CN
101965242 Feb 2011 CN
101980982 Feb 2011 CN
102046545 May 2011 CN
102060437 May 2011 CN
102105256 Jun 2011 CN
102248302 Nov 2011 CN
102272355 Dec 2011 CN
102326232 Jan 2012 CN
102343631 Feb 2012 CN
102356049 Feb 2012 CN
102356050 Feb 2012 CN
102574246 Jul 2012 CN
102596830 Jul 2012 CN
102642092 Aug 2012 CN
102649199 Aug 2012 CN
102672355 Sep 2012 CN
102674709 Sep 2012 CN
102741012 Oct 2012 CN
102898014 Jan 2013 CN
102916081 Feb 2013 CN
102923939 Feb 2013 CN
102962583 Mar 2013 CN
103013374 Apr 2013 CN
103079747 May 2013 CN
103086591 May 2013 CN
103143841 Jun 2013 CN
103159401 Jun 2013 CN
203021443 Jun 2013 CN
103237771 Aug 2013 CN
103273195 Sep 2013 CN
103316990 Sep 2013 CN
103329035 Sep 2013 CN
103339559 Oct 2013 CN
103359947 Oct 2013 CN
103359948 Oct 2013 CN
103531414 Jan 2014 CN
103746027 Apr 2014 CN
203509350 Apr 2014 CN
103817434 May 2014 CN
103831539 Jun 2014 CN
104108870 Oct 2014 CN
104344202 Feb 2015 CN
204211638 Mar 2015 CN
105081564 Nov 2015 CN
105164581 Dec 2015 CN
105209218 Dec 2015 CN
105246850 Jan 2016 CN
103224117 Feb 2016 CN
105392593 Mar 2016 CN
105517969 Apr 2016 CN
205328860 Jun 2016 CN
106007349 Oct 2016 CN
1020448 Dec 1957 DE
2231330 Oct 1974 DE
10322376 Dec 2004 DE
102006042280 Jun 2007 DE
102006035555 Jan 2008 DE
102011000768 Aug 2012 DE
102012010635 Nov 2013 DE
102012110971 May 2014 DE
102013103370 Oct 2014 DE
102013223637 May 2015 DE
102014213775 Jan 2016 DE
102014116958 May 2016 DE
102016102768 Aug 2017 DE
004167 Feb 2004 EA
270897 Feb 1992 EP
609978 Aug 1994 EP
656241 Dec 1998 EP
938946 Sep 1999 EP
949541 Oct 1999 EP
1306196 May 2003 EP
1159104 Aug 2004 EP
1609559 Dec 2005 EP
1043110 Aug 2006 EP
1990125 Nov 2008 EP
2105239 Sep 2009 EP
2133170 Dec 2009 EP
2202545 Jun 2010 EP
2258512 Dec 2010 EP
2398746 Dec 2011 EP
2574983 Apr 2013 EP
2754524 Jul 2014 EP
2781296 Sep 2014 EP
2783784 Oct 2014 EP
2859984 Apr 2015 EP
3311947 Apr 2018 EP
2989294 Oct 2013 FR
0768515 Feb 1957 GB
1242172 Aug 1971 GB
2481190 Jan 2015 GB
53-018756 Feb 1978 JP
61-027212 Feb 1986 JP
61-074794 Apr 1986 JP
62-046930 Feb 1987 JP
63-018756 Jan 1988 JP
63-192561 Aug 1988 JP
64-077001 Mar 1989 JP
1179770 Jul 1989 JP
05-274085 Oct 1993 JP
05-300544 Nov 1993 JP
06-082720 Mar 1994 JP
6318756 Nov 1994 JP
08-184581 Jul 1996 JP
09-109243 Apr 1997 JP
9106243 Apr 1997 JP
11-079770 Mar 1999 JP
11197498 Jul 1999 JP
11269683 Oct 1999 JP
11330597 Nov 1999 JP
11-347861 Dec 1999 JP
11347758 Dec 1999 JP
2000-225485 Aug 2000 JP
2000-327349 Nov 2000 JP
2001-130921 May 2001 JP
2001138083 May 2001 JP
2001-179473 Jul 2001 JP
2002-045985 Feb 2002 JP
2002-205181 Jul 2002 JP
2002210730 Jul 2002 JP
2002228818 Aug 2002 JP
2002-321081 Nov 2002 JP
2003025085 Jan 2003 JP
2003-088985 Mar 2003 JP
2003062756 Mar 2003 JP
2003114400 Apr 2003 JP
2003154517 May 2003 JP
2003181668 Jul 2003 JP
2003238178 Aug 2003 JP
3445250 Sep 2003 JP
2003-340579 Dec 2003 JP
2004-182530 Jul 2004 JP
2004209675 Jul 2004 JP
2004-348137 Dec 2004 JP
2005-000952 Jan 2005 JP
2005104819 Apr 2005 JP
2005-135964 May 2005 JP
2005-144487 Jun 2005 JP
2005-179154 Jul 2005 JP
2005-219960 Aug 2005 JP
2005205440 Aug 2005 JP
2005-263623 Sep 2005 JP
2005288503 Oct 2005 JP
2006-108478 Apr 2006 JP
3775250 May 2006 JP
3775410 May 2006 JP
2006130691 May 2006 JP
2006-150385 Jun 2006 JP
2006-182009 Jul 2006 JP
2006-240948 Sep 2006 JP
3823108 Sep 2006 JP
2006248885 Sep 2006 JP
2006-327711 Dec 2006 JP
2007021548 Feb 2007 JP
2007196277 Aug 2007 JP
2007253203 Oct 2007 JP
2008-018547 Jan 2008 JP
2008-132616 Jun 2008 JP
2008-168327 Jul 2008 JP
2008-522950 Jul 2008 JP
2008-266046 Nov 2008 JP
2008-288577 Nov 2008 JP
2009056482 Mar 2009 JP
2009-082958 Apr 2009 JP
2009-084089 Apr 2009 JP
2009-126779 Jun 2009 JP
2009-142886 Jul 2009 JP
2009-178725 Aug 2009 JP
2009172633 Aug 2009 JP
2009-255114 Nov 2009 JP
2009-269057 Nov 2009 JP
2010017990 Jan 2010 JP
2010-042424 Feb 2010 JP
4418282 Feb 2010 JP
2010046761 Mar 2010 JP
4592855 Dec 2010 JP
2011-011212 Jan 2011 JP
2011-037707 Feb 2011 JP
2011049398 Mar 2011 JP
2011-512259 Apr 2011 JP
4672689 Apr 2011 JP
2011-517622 Jun 2011 JP
2011517299 Jun 2011 JP
2011-138083 Jul 2011 JP
2011-520748 Jul 2011 JP
2011-147943 Aug 2011 JP
2011-240291 Dec 2011 JP
4880820 Feb 2012 JP
2012024782 Feb 2012 JP
2012031018 Feb 2012 JP
2012-506837 Mar 2012 JP
2012-517957 Aug 2012 JP
2012159749 Aug 2012 JP
2012-521889 Sep 2012 JP
2012187618 Oct 2012 JP
2012-232894 Nov 2012 JP
2012-528772 Nov 2012 JP
2013007842 Jan 2013 JP
2013031879 Feb 2013 JP
2013043808 Mar 2013 JP
2013-063863 Apr 2013 JP
2013075802 Apr 2013 JP
2013091578 May 2013 JP
2013-121908 Jun 2013 JP
2013-521131 Jun 2013 JP
2013-132664 Jul 2013 JP
2013-136075 Jul 2013 JP
2013-144613 Jul 2013 JP
2013-528492 Jul 2013 JP
2013-150990 Aug 2013 JP
2013-168445 Aug 2013 JP
5274085 Aug 2013 JP
2013-536081 Sep 2013 JP
5300544 Sep 2013 JP
2013187247 Sep 2013 JP
5318748 Oct 2013 JP
2013203630 Oct 2013 JP
2013203631 Oct 2013 JP
2013223886 Oct 2013 JP
2013-245153 Dec 2013 JP
2014-001102 Jan 2014 JP
2014-037006 Feb 2014 JP
2014-104484 Jun 2014 JP
2014-117707 Jun 2014 JP
2014-156289 Aug 2014 JP
2015-030040 Feb 2015 JP
2015-076115 Apr 2015 JP
2015-091606 May 2015 JP
2015-129076 Jul 2015 JP
2015-519722 Jul 2015 JP
2015-536896 Dec 2015 JP
2015-543336 Feb 2016 JP
2016-021077 Feb 2016 JP
2016-503383 Feb 2016 JP
6061193 Jan 2017 JP
2012015366 Feb 2002 KR
10-2002-0031573 May 2002 KR
2009057161 Jun 2009 KR
10-2009-0107417 Oct 2009 KR
2010-0120297 Nov 2010 KR
10-2011-0001948 Jan 2011 KR
1020621 Mar 2011 KR
10-2011-0120862 Nov 2011 KR
2011-0121637 Nov 2011 KR
10-2012-0000073 Jan 2012 KR
1120471 Mar 2012 KR
2012074508 Jul 2012 KR
2012-0102675 Sep 2012 KR
2013-0031377 Mar 2013 KR
2013031380 Mar 2013 KR
10-1259349 Apr 2013 KR
1269474 May 2013 KR
10-2013-0075651 Jul 2013 KR
2013-0079395 Jul 2013 KR
10-2013-0111269 Oct 2013 KR
2013124646 Nov 2013 KR
10-2013-0135873 Dec 2013 KR
10-2013-0140561 Dec 2013 KR
1344368 Dec 2013 KR
2014022980 Feb 2014 KR
2014022981 Feb 2014 KR
2014064220 May 2014 KR
10-2014-0112652 Sep 2014 KR
10-2015-0009153 Jan 2015 KR
2015-0016176 Feb 2015 KR
2017998 Jun 2018 NL
480550 Mar 2002 TW
201041027 Nov 2010 TW
201107253 Mar 2011 TW
201139025 Nov 2011 TW
1362370 Apr 2012 TW
201226345 Jul 2012 TW
201311592 Mar 2013 TW
201331136 Aug 2013 TW
201339111 Oct 2013 TW
201433550 Sep 2014 TW
201436968 Oct 2014 TW
I468354 Jan 2015 TW
I520804 Feb 2016 TW
201612615 Apr 2016 TW
9821154 May 1998 WO
1999029243 Jun 1999 WO
1999063900 Dec 1999 WO
0051778 Sep 2000 WO
0239063 May 2002 WO
2003007370 Jan 2003 WO
2004110693 Dec 2004 WO
2006017583 Feb 2006 WO
2006073098 Jul 2006 WO
2007094160 Aug 2007 WO
2007119740 Oct 2007 WO
2008012186 Jan 2008 WO
2008049389 May 2008 WO
2008080182 Jul 2008 WO
2008102848 Aug 2008 WO
2008108332 Sep 2008 WO
2008126742 Oct 2008 WO
2008128612 Oct 2008 WO
2009012913 Jan 2009 WO
2009114372 Sep 2009 WO
2009114375 Sep 2009 WO
2009119694 Oct 2009 WO
2010035736 Apr 2010 WO
2010096359 Aug 2010 WO
2010111609 Sep 2010 WO
2010129459 Nov 2010 WO
2011025908 Mar 2011 WO
2011056781 May 2011 WO
2012006736 Jan 2012 WO
2012075072 Jun 2012 WO
2012108052 Aug 2012 WO
2012166753 Dec 2012 WO
2013016157 Jan 2013 WO
2013022148 Feb 2013 WO
2013043173 Mar 2013 WO
2013084877 Jun 2013 WO
2013084879 Jun 2013 WO
2013138802 Sep 2013 WO
2013150990 Oct 2013 WO
2013153195 Oct 2013 WO
2014010490 Jan 2014 WO
2014012125 Jan 2014 WO
2014028022 Feb 2014 WO
2014058663 Apr 2014 WO
2014075995 May 2014 WO
2014064492 May 2014 WO
2014079478 May 2014 WO
2014079570 May 2014 WO
2014085663 Jun 2014 WO
2014111385 Jul 2014 WO
2014111794 Jul 2014 WO
2014121261 Aug 2014 WO
2014132493 Sep 2014 WO
2014161534 Oct 2014 WO
2014161535 Oct 2014 WO
2015077113 May 2015 WO
2015094898 Jun 2015 WO
2015095151 Jun 2015 WO
2015095088 Jun 2015 WO
2015095090 Jun 2015 WO
2015095146 Jun 2015 WO
2015114032 Aug 2015 WO
2015128833 Sep 2015 WO
2015132008 Sep 2015 WO
2015127583 Sep 2015 WO
2016007843 Jan 2016 WO
2016010991 Jan 2016 WO
2016005455 Jan 2016 WO
2016010954 Jan 2016 WO
2016079275 May 2016 WO
2016089799 Jun 2016 WO
2016100954 Jun 2016 WO
20160154284 Sep 2016 WO
2017009149 Jan 2017 WO
2017079570 May 2017 WO
2017091529 Jun 2017 WO
2017093393 Jun 2017 WO
Non-Patent Literature Citations (126)
Entry
Arimoto, R. et al.; Imaging properties of axicon in a scanning optical system; Applied Optics; Nov. 1, 1991; pp. 6653-6657; vol. 31, No. 31; Optical Society of America.
Betriebsanleitung; TruMicro 5000; Aug. 2011; pp. 1-4.
Bhuyan, M. et al.; High aspect ratio nanochannel machining using single shot femtosecond Bessel beams; Applied Physics Letters; Aug. 23, 2010; pp. 081102-1-081102-3; vol. 97.
Bhuyan, M. et al.; High aspect ratio taper-free microchannel fabrication using femtosecond Bessel beams; Optics Express; Jan. 18, 2010; pp. 566-574; vol. 18, No. 2; Optical Society of America.
Cubeddu, R. et al.; A compact time-resolved reflectance system for dual-wavelength multichannel assessment of tissue absorption and scattering; SPIE Conference on Optical Tomography and Spectroscopy of Tissue III; San Jose, California; Jan. 1999; pp. 450-455; vol. 3597; SPIE.
Cubeddu, R. et al.; Compact tissue oximeter based on dual-wavelength multichannel time-resolved reflectance; Applied Optics; Jun. 1, 1999; pp. 3670-3680; vol. 38, No. 16; Optical Society of America.
Ding, Z. et al.; High-resolution optical coherence tomography over a large depth range with an axicon lens; Optics Letters; Feb. 15, 2002; pp. 243-245; vol. 27, No. 4; Optical Society of America.
EagleEtch; TheAnti-glare Glass for Technical Display Applications; Glass and Polymer Technologies; pp. 1-8 EuropTec USA Inc.
Girkin, J. et al.; Macroscopic multiphoton biomedical imaging using semiconductor saturable Bragg reflector modelocked Lasers; SPIE Conference on Commercial and Biomedical Applications of Ultrafast Lasers; San Jose, California; Jan. 1999; pp. 92-98; vol. 3616; SPIE.
Glezer, E. et al.; Ultrafast-laser driven micro-explosions in transparent materials; Applied Physics Letters; 1997; pp. 882-884, vol. 71.
Golub, I.; Fresnel axicon; Optics Letters; Jun. 15, 2006; pp. 1890-1892;. vol. 31, No. 12; Optical Society of America.
Herman, P. et al.; Laser micromachining of ‘transparent’ fused silica with 1-ps pulses and pulse trains; SPIE Conference on Commercial and Biomedical Applications of Ultrafast Lasers; San Jose, California; Jan. 1999; pp. 148-155; vol. 3616; SPIE.
Kosareva, O. et al.; Formation of extended plasma channels in a condensed medium upon axicon focusing of a femtosecond laser pulse; Quantum Electronics; 2005; pp. 1013-1014; vol. 35, No. 11; Kvantovaya Elektronika and Turpion Ltd.
Kruger, J. et al.; Femtosecond-pulse visible laser processing of transparent materials; Applied Surface Science; 1996; pp. 430-438; Elsevier B.V.
Kruger, J. et al.; Laser micromachining of barium aluminium borosilicate glass with pulse durations between 20 fs and 3 ps; Applied Surface Science; 1998; pp. 892-898; Elsevier B.V.
Kruger, J. et al.; Structuring of dielectric and metallic materials with ultrashort laser pulses between 20 fs and 3 ps; SPIE Proceedings; San Jose, California; Feb. 8, 1997; pp. 40-47 vol 2991; SPIE.
Lapczyna, M. et al.; Ultra high repetition rate (133 MHz) laser ablation of aluminum with 1.2-ps pulses; Applied Physics A Materials Science & Processing; Dec. 28, 1999; pp. S883-S886; vol. 69 (Suppl).; Springer-Verlag.
Perry, M. et al.; Ultrashort-Pulse Laser Machining; Lawrence Livermore National Laboratory; Sep. 1998; pp. i-30.
Perry, M. et al.; Ultrashort-Pulse Laser Machining; International Congress on Applications of Lasers and Electro-Optics; Orlando, Florida; Nov. 16-19, 1998; pp. 1-24.
Perry, M. et al.; Ultrashort-pulse laser machining of dielectric materials; Journal of Applied Physics; May 1, 1999 pp. 6803-6810; vol. 85, No. 9; American Institute of Physics.
Pharos High-power Femtosecond Laser System specification; Light Conversion; 2011; pp. 1-2.
Polynkin, P. et al.; Extended filamentation with temporally chirped femtosecond Bessel-Gauss beams in air; Optics Express; Jan. 19, 2009; pp. 575-584; vol. 17, No. 2; Optical Society of America.
Serafetinides, A. et al.; Ultra-short pulsed laser ablation of polymers; Applied Surface Science; 2011; pp. 42-56; vol. 180; Elsevier Science B.V.
Sundaram, S. et al.; Inducing and probing non-thermal transitions in semiconductors using femtosecond laser pulses; Nature Materials; Dec. 2002; pp. 217-224; vol. 1; Nature Publishing Group.
Vanagas, E. et al.; Glass cutting by femtosecond pulsed irradiation; Journal of Micro/Nanolithography, MEMS, and MOEMS; Mar. 31, 2004; pp. 1-18; vol. 3, Issue 2; SPIE.
Varel, H. et al.; Micromachining of quartz with ultrashort laser pulses; Applied Physics A Materials Science & Processing; 1997; pp. 367-373; vol. 65.
Yoshino, F. et al.; Micromachining with a High Repetition Rate Femtosecond Fiber Laser; JLMN—Journal of Laser Micro/Nanoengineering; 2008; pp. 157-162; vol. 3, No. 3.
Zeng, D. et al.; Characteristic analysis of refractive axicon system for optical trepanning; Optical Engineering; Sep. 2006; pp. 094302-1-094302-10; vol. 45, No. 9.
Zhang, G. et al.; Design of diffractive-phase axicon illuminated by a Gaussian-profile beam; Acta Physica Sinica; May 1996; pp. 354-364; vol. 5, No. 5; Chin. Phys. Soc.
Abakians, H. et al.; Evaporative Cutting of a Semitransparent Body With a Moving CW Laser; Journal of Heat Transfer; Nov. 1988; pp. 924-930; vol. 110; ASME.
Ahmed, F. et al.; Display glass cutting by femtosecond laser induced single shot periodic void array; Applied Physics A Material Science & Processing; Jun. 3, 2008; pp. 189-192; vol. 93; Springer-Verlag.
Bagchi, S. et al.; Fast ion beams from intense, femtosecond laser irradiated nanostructured surfaces; Applied Physics B Lasers and Optics; Jun. 27, 2007; pp. 167-173; vol. 88; Springer-Verlag.
Bhuyan, M.K. et al.; Femtosecond non-diffracting Bessel beams and controlled nanoscale ablation; ResearchGate Conference Paper; Sep. 2011; pp. 1-4.
Bhuyan, M.K. et al.; Laser micro- and nanostructuring using femtosecond Bessel beams; The European Physical Journal Special Topics; Dec. 7, 2011; pp. 101-110; vol. 1999; EDP Sciences, Springer-Verlag.
Bhuyan, M.K. et al.; Single-shot high aspect ratio bulk nanostructuring of fused silica using chirp-controlled ultrafast laser Bessel beams; Applied Physics Letters; Jan. 14, 2014; pp. 021107-1-021107-4; vol. 104; AIP Publishing LLC.
Bhuyan, M.K. et al.; Ultrafast Bessel beams for high aspect ratio taper free micromachining of glass; Nonlinear Optics and Applications IV; 2010; pp. 77281V-1-77281V-8; vol. 7728; SPIE.
Case Design Guidelines for Apple Devices; Sep. 13, 2013; pp. 1-58; Apple Inc.
Chiao, R. Y. et al.; Self-Trapping of Optical Beams; Physical Review Letters; Oct. 12, 1964; pp. 479-482; vol. 13, No. 15.
Corning EAGLE AMLCD Glass Substrates Material Information; Apr. 2005; pp. MIE 201-1-MIE 201-3; Corning Incorporated.
Corning 1737 AMLCD Glass Substrates Material Information; Aug. 2002; pp. MIE 101-1-MIE 101-3; Corning Incorporated.
Couairon, A. et al.; Femtosecond filamentation in transparent media; ScienceDirect Physical Reports; Feb. 6, 2007; pp. 47-189; vol. 441; Elsevier B.V.
Courvoisier, F. et al.; Applications of femtosecond Bessel beams to laser ablation; Applied Physics A Materials Science & Processing; Sep. 6, 2012; pp. 29-34; vol. 112; Springer-Veriag.
Courvoisier, F. et al.; Surface nanoprocessing with nondiffracting femtosecond Bessel beams; Optics Letters; Oct. 15, 2009; pp. 3163-3165; vol. 34, No. 20; Optical Society of America.
Dong, M. et al.; On-axis irradiance distribution of axicons illuminated by spherical wave; ScienceDirect Optics & Laser Technology; Sep. 2007; pp. 1258-1261; vol. 39; Elsevier Ltd.
Duocastella, M. et al.; Bessel and annular beams for materials processing; Laser & Photonics Reviews; 2012; pp. 607-621; vol. 6, No. 5.
Durnin, J.; Exact solutions for nondiffracting beams. I. The scalar theory; J. Opt. Soc. Am. A; Apr. 1987; pp. 651-654; vol. 4, No. 4; Optical Society of America.
Eaton, S. et al.; Heat accumulation effects in femtosecond laser-written waveguides with variable repetition rate; Optics Express; Jun. 13, 2005; pp. 4708-4716; vol. 13, No. 12; Optical Society of America.
Gattass, R. et al.; Micromachining of bulk glass with bursts of femtosecond laser pulses at variable repetition rates; Optics Express; Jun. 12, 2006; pp. 5279-5284; vol. 14, No. 12; Optical Society of America.
Gori, F. et al.; Analytical derivation of the optimum triplicator; Optics Communications; Dec. 1, 1998; pp. 13-16; vol. 157; Elsevier B.V.
Honda, M. et al.; A Novel Polymer Film that Controls Light Transmission; Progress in Pacific Polymer Science 3; 1994; pp. 159-169; Springer-Verlag Berlin Heidelberg.
Hu, Z. et al.; 5-Axis Laser Cutting Interference Detection and Correction Based on STL Model; Chinese Journal of Lasers; Dec. 2009; pp. 3313-3317; vol. 36, No. 12.
Huang, Z. et al.; Laser etching of glass substrates by 1064 nm laser irradiation; Applied Physics A Materials Science & Processing; Jun. 6, 2008; pp. 159-163; vol. 93; Springer-Verlag.
Juodkazis, S. et al.; Laser-Induced Microexplosion Confined in the Bulk of a Sapphire Crystal: Evidence of Multimegabar Pressures; Physical Review Letters; Apr. 28, 2006; pp. 166101-1-166101-4; vol. 96; The American Physical Society.
Karlsson, S. et al.; The Technology of Chemical Glass Strengthening—A Review; Glass Technology—European Journal of Glass Science and Technology Part A; Apr. 2010; pp. 41-54; vol. 51, No. 2.
Levy, U. et al.; Design, fabrication, and characterization of circular Dammann gratings based on grayscale lithography; Optics Letters; Mar. 15, 2010; pp. 880-882; vol. 35, No. 6; Optical Society of America.
Liu, X. et al.; Laser Ablation and Micromachining with Ultrashort Laser Pulses; IEEE Journal of Quantum Electronics; Oct. 1997; pp. 1706-1716; vol. 33, No. 10; IEEE.
Maeda, K. et al.; Optical performance of angle dependent light control glass; Optical Materials Technology for Energy Efficiency and Solar Energy Conversion X; 1991; pp. 138-148; vol. 1536; SPIE.
Mbise, G. et al.; Angular selective window coatings; theory and experiments; J. Phys. D: Appl. Phys.; 1997; pp. 2103-2122; vol. 30; IOP Publishing Ltd.
McGloin, D. et al.; Bessel beams: diffraction in a new light; Contemporary Physics; Jan.-Feb. 2005; pp. 15-28; vol. 46; Taylor & Francis Ltd.
Merola, F. et al.; Characterization of Bessel beams generated by polymeric microaxicons; Measurement Science and Technology; May 15, 2012; pp. 1-10; vol. 23; IOP Publishing Ltd.
Mirkhalaf, M. et al.; Overcoming the biillleness of glass through bio-inspiration and micro-architecture; Nature Communications; Jan. 28, 2014; pp. 1-9; Macmillan Publishers Limited.
Romero, L. et al.; Theory of optimal beam splitting by phase gratings. II. Square and hexagonal gratings; J. Opt. Soc. Am. A; Aug. 2007; pp. 2296-2312; vol. 24, No. 8; Optical Society of America.
Salleo, A. et al.; Machining of transparent materials using an IR and UV nanosecond pulsed laser; Applied Physics A Materials Science & Processing; Sep. 20, 2000; pp. 601-608; vol. 71; Springer-Veriag.
Serafetinides, A. et al.; Polymer Ablation by Ultra-Short Pulsed Lasers; Proceedings of SPIE; 2000; pp. 409-415.
Shah, L. et al.; Micromachining with a High Repetition Rate Femtosecond Fiber Laser; JLMN—Journal of Laser Micro/Nanoengineering; Nov. 2008; pp. 157-162; vol. 3, No. 3.
Shealy, D. et al.; Geometric optics-based design of laser beam shapers; Opt. Eng.; Nov. 2003; pp. 3123-3138; vol. 42, No. 11; Society of Photo-Optical Instrumentation Engineers.
Yan, Y. et al.; Fiber structure to convert a Gaussian beam to higher-order optical orbital angular momentum modes; Optics Letters; Aug. 15, 2012; pp. 3294-3296; vol. 37, No. 16; Optical Society of America.
Abramov, A. et al.; Laser separation of chemically strengthened glass; ScienceDirect Physics Procedia; 2010; pp. 285-290; vol. 5; Elsevier B.V.
Stoian, R. et al.; Spatial and temporal laser pulse design for material processing on ultrafast scales; Applied Physics A Materials Science & Processing; Jan. 1, 2014; pp. 119-127; vol. 114; Springer-Veriag Berlin Heidelberg.
Thiele, E.; Relation between Catalytic Activity and Size of Particle; Industrial and Engineering Chemistry; Jul. 1939; pp. 916-920; vol. 31, No. 7.
Toytman, I. et al.; Optical breakdown in transparent media with adjustable axial length and location; Optic Express; Nov. 22, 2010; pp. 24688-24698; vol. 18, No. 24; Optical Society of America.
Velpula, P. et al.; Ultrafast imaging of free carriers: controlled excitation with chirped ultrafast laser Bessel beams; Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XIX; Proc. of SPIE; 2014; pp. 896711-1-896711-8; vol. 8967; SPIE.
Nang, Z. et al.; Investigation on CO2 laser irradiation inducing glass strip peeling for microchannel formation; Biomicrofluidics; Mar. 12, 2012; pp. 012820-1-012820-12; vol. 6; American Institute of Physics.
Ra & RMS: Calculating Surface Roughness; Harrison Eelectropolishing; 2012.
Wu, W. et al.; Optimal Orientation of the Cutting Head for Enhancing Smoothness Movement in Three-Dimensional Laser Cutting; Chinese Journal of Lasers; Jan. 2013; pp. 0103005-1-0103005-7, vol. 10, No. 1.
GT ASF Grown Sapphire Cover and Touch Screen Material; www.gtat.com; 2012; pp. 1-2; GTAT Corporation.
Xu, H. et al.; Optimization of 3D laser cutting head orientation based on minimum energy consumption; Int J Adv Manuf Technol; Jun. 28, 2014; pp. 1283-1291; vol. 74; Springer-Verlag London.
Kerr. “Filamentary tracks formed in transparent optical glass by laser beam self-focusing. II. Theoretical Analysis” Physical Review A. 4(3) 1971, pp. 1196-1218.
“Aviation Manufacturing Technology”; Beijing Aviation Manufacturing Engineering Research Institute Aviation Industry Press; (2013) p. 147.
“EagleEtch” Product Brochure, EuropeTec USA Inc., pp. 1-8, Aug. 1, 2014.
“TruMicro 5000” Product Manual, Trumpf Laser GmbH +Co.KG, pp. 1-4, Aug. 2011.
Amended claims 1,2 Amended Claims (Nov. 21, 2018) GMvp4 p. 1.
Analyse of claims 1-11 GMvP7 p. 1.
Betriebsanleitung TruMicro Series 5000, “Ausgabe May 2008 Betriebsanleitung TruMicro Series 5000_Anlage E2a-1.pdf”.
Case Design Guidelines for Apple Devices Release R5 (https://web.archive.org/web/20131006050442/https://developer.apple.com/resources/cases/Case-Design-Guidelines.pdf; archived on Oct. 6, 2013).
Case study: Simulation einer Beschneidung des Fernfelds eines Bessel-GauB-Strahls GMvP6 p. 1.
Claim 1—published on Nov. 20, 2019 EP947: Anspruch 1—erteilt am Nov. 20, 2019 GMvp5 p. 1.
Coming Inc., Coming Eagle2000TM AMLCD Glass Substrates Material Information, issued Apr. 2005. (Year: 2005).
D5 Claims GMvP2 p. 1.
D6 Amended claim 1 EP947: Anspruch 1—geandert am Nov. 21, 2018 GMvp3 p. 1.
European Patent Application No. 15750162.8 Communication under Rule 71(3) EPC dated Dec. 11, 2018; 6 Pages; European Patent Office.
European Patent Application No. 15750162.8 Communication under Rule 71(3) EPC dated Jul. 27, 2017; 6 Pages; European Patent Office.
European Patent Application No. 15750162.8 Decision to grant a European patent dated Jan. 8, 2020; 2 Pages; European Patent Office.
European Patent Application No. 15750162.8 Office Action dated Feb. 20, 2018; 4 Pages; European Patent Office.
European Patent Application No. 19172136.4 Office Action dated Nov. 5, 2020; 5 Pages; European Patent Office.
Extended European Search Report and Search Opinion; 19172136.4; dated Nov. 13, 2019; 11 pages; European Patent Office.
Faccio et al. “Kerr-induced spontaneous Bessel beam formation in the regime of strong two-photon absorption” Optics Express 16(11) 2008, pp. 8213-8218.
Flamm et al., “Higher-order Bessel-like Beams for Optimized Ultrafast Processing of Transparent Materials” GMvP 19.
Flamm et al., “Higher-order Bessel-like Beams for Optimized Ultrafast Processing of Transparent Materials” GMvP 20.
Gollier et al., U.S. Appl. No. 62/024,122, “Systems and Methods for Processing Transparent Materials Using Adjustable Laser Beam Focal Lines”, filed Jul. 14, 2014., U.S. Appl. No. 62/024,122.
High aspect ratio machining . . . Anlage E8-1.pdf.
http://www.gtat.com/Collateral/Documents/Engltsh-US/Sapphire/12-21-12_GT_TnuchScreen_ V3_web.pdf.
International Search Report and Written Opinion of the International Searching Authority; PCT/US2015/040259; dated Mar. 8, 2016; 22 Pages; European Patent Office.
Merkmalsgliederung Patentanspruch 1 des Streitpatents, “Merkmalsgliederung Patentanspruch 1 _Anlage E15-1.pd1”.
Merkmalsgliederung Patentanspruch 12 des Streitpatents,“Merkmalsgliederung Patentanspruch 12 _Anlage E16-1.pdf”.
Norm: DI N EN ISO 11146-2, 2005 DIN EN ISO 11146-2 May 2, 2005 GMvP 21 pages.
Norm: DIN EN ISO 11146-1, 2005 GMVP DIN EN ISO 11146:1999-09, Apr. 1, 2005 GMvP 23 pages.
Norm: ISO/TR 11146-3 , Technical Report First edition GMvP Norm-TR 1 Pages.
Polesana (Polesana, P., Dubietis, A., Porras, A. Kucinskas, E. Faccio, D. Couairon, A. and DiTrapani, P.,, “Near-field dynamics of ultrashort pulsed Bessel beams in media with Kerr nonlinearity”, Physical Review E 73, 056612 (2006)).
Product Data Sheet for Corning Eagle XG Slim Glass, Issued Aug. 2013; 2 Pages.
Product data sheet for Corning Eagle XR glass substrate, issued Jan. 2006 (Year: 2006).
Produktbeschreibung Pharos Laser vom Apr. 18, 2011, “Pharos_2011 Anlage E 1 a-1. pdf”.
U.S. Appl. No. 62/208,282, filed Aug. 21, 2015.
Sukumaran, “Design, Fabrication, and Characterization of Ultrathin 3-D Glass Interposers with Through-Package-Vias at Same Pitch as TSVs in Silicon.” IEEE Transactions on Components, Packaging and Manufacturing Technology, vol. 4, No. 5: 786-795, (2014.).
Sukumaran, “Through-Package—via Formation and Metallization of Glass Interposers.”, Electronic Components and Technology Conference: 557-563, (2010.).
U.S. Appl. No. 62/137,443, “Laser Cutting and Processing of Display Glass Compositions”, filed Mar. 24, 2015., U.S. Appl. No. 62/137,443.
Unichains, Engineering Manual: Innovative Belt & Chain solutions for every industry and application, available publically at least as of Jun. 1, 2016 as evidenced at the following hyperlink: https://web.archive.org/web/20160601000000/http://www.unichains.com/.
What is the difference between Ra and RMS?; Harrison Electropolishing LP; (http://www.harrisonep.com/electropolishingra.html), Accessed Aug. 8, 2016.
ICNIRP, Infrared Radiation, https://www.icnirp.org/en/frequencies/infrared/index.html#:˜:text=Wavelength, accessed Apr. 7, 2021 (Year: 2014).
Liu,Xiuwen, “Graphical Audio-Visual Technology Tips”, Apr. 30, 2006, pp. 58-59. (Original Document Only).
Tian e al., “Development status and Prospects of TFT-LCD Substrate Glass Chemical Composition”, vol. 29, No. 6, 2010, pp. 1348-1362 (English Abstract Submitted).
Tsai et al. ,“Internal modification for cutting transparent glass using femtosecond Bessel beams”, Optical Engineering, Soc. of Photo-optical Instrumentation Engineering, Bellingham, vol. 53, May 2014, p. 51503.
Tymon Barwicz, et al., “Assembly of Mechanically Compliant Interfaces between Optical Fibers and Nanophotonic Chips”, Tymon Barwicz (IBM), et al., Electronic Components & Technology Conference, 2014,. 978-1799-2407-3, 2014 IEEE, pp. 179-185.
Chinese Patent Application No. 201780065972.0, Office Action dated Apr. 15, 2022, 14 pages (6 pages of English Translation and 8 pages of Original Document), Chinese Patent Office.
Japanese Patent Application No. 2020-116177, Decision to Grant, dated Jul. 6, 2022, 5 pages (2 pages of English Translation and 3 pages of Original Copy); Japanese Patent Office.
Japanese Patent Application No. 2020-116177, Office Action dated Aug. 3, 2021, 10 pages (5 pages of English Translation and 5 pages of Original Document), Japanese Patent Office.
Related Publications (1)
Number Date Country
20170189991 A1 Jul 2017 US
Provisional Applications (1)
Number Date Country
62024122 Jul 2014 US