Method and device for the laser-based machining of sheet-like substrates

Information

  • Patent Grant
  • 11345625
  • Patent Number
    11,345,625
  • Date Filed
    Wednesday, July 31, 2019
    4 years ago
  • Date Issued
    Tuesday, May 31, 2022
    a year ago
Abstract
A method for the laser-based machining of a sheet-like substrate, in order to separate the substrate into multiple portions, in which the laser beam of a laser for machining the substrate is directed onto the latter, is characterized in that, with an optical arrangement positioned in the path of rays of the laser, an extended laser beam focal line, seen along the direction of the beam, is formed on the beam output side of the optical arrangement from the laser beam directed onto the latter, the substrate being positioned in relation to the laser beam focal line such that an induced absorption is produced in the material of the substrate in the interior of the substrate along an extended portion, seen in the direction of the beam, of the laser beam focal line, such that a material modification takes place in the material of the substrate along this extended portion.
Description
BACKGROUND

The disclosure relates generally to a method for the laser-based machining of preferably sheet-like substrates and to a corresponding device and to the use of methods and devices for separating sheet-like substrates, such as for example semiconductor wafers, glass elements, . . . (in particular of brittle materials) into multiple parts (individually separating the wafers or glass elements). As further described in detail below, work is in this case performed using lasers, generally pulsed lasers, with a wavelength to which the materials are substantially transparent. Devices and methods for severing such materials by means of a laser are already known from the prior art. On the one hand (for example DE 10 2011 000 768 A1), it is possible to use lasers which, by virtue of their wavelength or their power, are strongly absorbed by the material, or after the first interaction make the material strongly absorbent (heating with for example the generation of charge carriers; induced absorption), and can then ablate the material. This method has disadvantages in the case of many materials: for example impurities due to particle formation in the ablation; cut edges may have microcracks on account of the heat input; cut edges may have melt edges; the cutting gap is not uniform over the thickness of the material (has a different width at different depths; for example a wedge-shaped cutting notch). Since material has to be vaporized or liquefied, a high average laser power has to be provided.


On the other hand, there are known laser methods for severing brittle materials that function on the basis of a specifically directed, laser-induced crack formation. For example, there is a method from Jenoptik in which a trace on the surface is first strongly heated by the laser, and immediately thereafter this trace is cooled so quickly (for example by means of a water jet) that the thermal stresses thereby achieved lead to crack formation, which may be propagated through the thickness of the material (mechanical stress) in order to sever the material.


There are also methods in which a laser at the wavelength of which the material is largely transparent is used, so that a focal point can be produced in the interior of the material. The intensity of the laser must be so high that internal damage takes place at this internal focal point in the material of the irradiated substrate.


The last-mentioned methods have the disadvantage that the induced crack formation takes place in the form of a point at a specific depth, or on the surface, and so the full thickness of the material is only severed by way of an additional, mechanically and/or thermally induced crack propagation. Since cracks tend to spread unevenly, the separating surface is usually very rough and must often be re-worked. Moreover, the same process has to be applied a number of times at different depths. This in turn slows down the speed of the process by the corresponding multiple.


No admission is made that any reference cited herein constitutes prior art. Applicant expressly reserves the right to challenge the accuracy and pertinency of any cited documents.


SUMMARY

An object of the present invention is therefore to provide a method (and a corresponding device) with which sheet-like substrates, in particular of brittle materials, can be machined, in particular completely severed, without significant particle formation, without significant melt edges, with minimal crack formation at the edge, without significant cutting gaps (that is to say material losses), with straightest-possible cut edges and with a high speed of the process.


One embodiment of the disclosure relates to a method that includes focusing a pulsed laser beam into a laser beam focal line, viewed along the beam propagation direction, the laser beam focal line having a length in a range of between 0.1 mm and 100 mm, and directing the laser beam focal line into a material at an angle of incidence to a surface of the material, the laser beam focal line generating an induced absorption within the material, the induced absorption producing a material modification along the laser beam focal line within the material.


An additional embodiment of the disclosure relates to a system that includes a pulsed laser and an optical assembly positioned in the beam path of the laser, configured to transform the laser beam into an laser beam focal line, viewed along the beam propagation direction, on the beam emergence side of the optical assembly, the laser beam focal line having a length in a range of between 0.1 mm and 100 mm, the optical assembly including a focusing optical element with spherical aberration configured to generate the laser beam focal line, said laser beam focal line adapted to generate an induced absorption within a material, the induced absorption producing a material modification along the laser beam focal line within the material.


Another embodiment of the disclosure relates to a glass article that includes at least one surface having a plurality of material modifications along the surface, each material modification having a length in a range of between 0.1 mm and 100 mm, and an average diameter in a range of between 0.5 μm and 5 μm. Yet another embodiment of the disclosure relates to a glass article comprising at least one surface having a plurality of material modifications along the surface, each material modification having a ratio V3=α/δ of the average distance α of the directly neighboring material modifications and the average diameter δ of a laser beam focal line that created the material modifications equal to approximately 2.0.


Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from the description or recognized by practicing the embodiments as described in the written description and claims hereof, as well as the appended drawings.


It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understand the nature and character of the claims.


The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the description serve to explain principles and operation of the various embodiments.





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 shows the relationship between the heat diffusion constant α, the linear extent in the material (scale length, denoted here by d) and a time duration τ, such as for example the laser pulse duration for various materials.



FIG. 2 shows the principle of the positioning of a focal line, that is to say the machining of a material that is transparent to the laser wavelength, on the basis of the induced absorption along the focal line.



FIG. 3a shows a first optical arrangement that can be used in embodiments described herein.



FIG. 3b shows various possible ways of machining the substrate by different positioning of the laser beam focal line in relation to the substrate.



FIG. 4 shows a second optical arrangement that can be used in embodiments described herein.



FIGS. 5a and 5b show a third optical arrangement that can be used in embodiments described herein.



FIG. 6 shows a fourth optical arrangement that can be used in embodiments described herein.



FIG. 7 shows a setup for carrying out the method in the example of the first usable optical arrangement from FIG. 3a (instead of this optical arrangement, the further optical arrangements shown in FIGS. 4, 5 and 6 may also be used within the scope of the arrangement shown, in that the optical arrangement 6 shown in FIG. 7 is replaced by one of these arrangements).



FIG. 8 shows the production of a focal line in detail.



FIG. 9 shows a micrograph of the surface (plan view of the plane of the substrate) of a glass sheet machined as described herein.





DETAILED DESCRIPTION

Various embodiments will be further clarified by the following examples.


One embodiment of the disclosure relates to a method that includes focusing a pulsed laser beam into a laser beam focal line, viewed along the beam propagation direction, the laser beam focal line having a length in a range of between 0.1 mm and 100 mm, and directing the laser beam focal line into a material at an angle of incidence to a surface of the material, the laser beam focal line generating an induced absorption within the material, the induced absorption producing a material modification along the laser beam focal line within the material. The method can further include translating the material and the laser beam relative to each other, thereby producing a plurality of material modifications within the material, the material modifications spaced apart so as to separate the material into at least two pieces. The laser beam can have an average laser energy measured at the material less than about 400 μJ, such as less than about 250 μJ. The pulse duration can be in a range of between greater than about 10 picoseconds and less than about 100 picoseconds, or less than 10 picoseconds. The pulse repetition frequency can be in a range of between 10 kHz and 1000 kHz, such as in a range of between 10 kHz and 100 kHz, or less than 10 kHz. The material can be glass, sapphire, a semiconductor wafer, or the like. Material modification can be crack formation. The angle of incidence of the laser beam focal line can be less than or equal to about 45 degrees to the surface of the material, such as perpendicular to the surface of the material. The laser beam focal line can be contained entirely within the material, with the laser beam focal line not extending to either surface of the material. The material modification can extend within the material to at least one of two opposing surfaces of the material, such as extending within the material from one of two opposing surfaces of the material to the other one of the two opposing surfaces, over the entire thickness of the material. In particular, for each laser pulse, the material modification can extend within the material from one of two opposing surfaces of the material to the other one of the two opposing surfaces, over the entire thickness of the material. The pulsed laser beam can have a wavelength selected such that the material is substantially transparent at this wavelength. The wavelength can be less than about 1.8 μm. The laser beam focal line can have an average spot diameter in a range of between 0.5 μm and 5 μm.


An additional embodiment of the disclosure relates to a system that includes a pulsed laser and an optical assembly positioned in the beam path of the laser, configured to transform the laser beam into an laser beam focal line, viewed along the beam propagation direction, on the beam emergence side of the optical assembly, the laser beam focal line having a length in a range of between 0.1 mm and 100 mm, the optical assembly including a focusing optical element with spherical aberration configured to generate the laser beam focal line, said laser beam focal line adapted to generate an induced absorption within a material, the induced absorption producing a material modification along the laser beam focal line within the material. The laser energy, pulse duration, pulse repetition frequency, wavelength, focal line diameter, material, and material modification for the system can be as described above for the method. The optical assembly can include an annular aperture positioned in the beam path of the laser before the focusing optical element, the annular aperture configured to block out one or more rays in the center of the laser beam so that only marginal rays outside the center inside on the focusing optical element, and thereby only a single laser beam focal line, viewed along the beam direction, is produced for each pulse of the pulsed laser beam. The focusing optical element can be a spherically cut convex lens, such as a conical prism having a non-spherical free surface, such as an axicon. The optical assembly can further include a second optical element, the two optical elements positioned and aligned such that the laser beam focal line is generated on the beam emergence side of the second optical element at a distance from the second optical element.


Another embodiment of the disclosure relates to a glass article that includes at least one surface having a plurality of material modifications along the surface, each material modification having a length in a range of between 0.1 mm and 100 mm, and an average diameter in a range of between 0.5 μm and 5 μm. Yet another embodiment of the disclosure relates to a glass article comprising at least one surface having a plurality of material modifications along the surface, each material modification having a ratio V3=α/δ of the average distance α of the directly neighboring material modifications and the average diameter δ of a laser beam focal line that created the material modifications equal to approximately 2.0.


The present disclosure is described below, at first generally, then in detail on the basis of several exemplary embodiments. The features shown in combination with one another in the individual exemplary embodiments do not all have to be realized. In particular, individual features may also be omitted or combined in some other way with other features shown of the same exemplary embodiment or else of other exemplary embodiments. It is also possible that individual features of one exemplary embodiment already in themselves display advantageous developments of the prior art.


The mechanism of separating the substrate into individual parts is first described below.


The separating method produces for each laser pulse a laser focal line (as distinct from a focal point) by means of laser optics suitable therefor (hereinafter also referred to as an optical arrangement). The focal line determines the zone of the interaction between the laser and the material of the substrate. If the focal line falls in the material to be separated, the laser parameters can be chosen such that an interaction with the material which produces a crack zone along the focal line takes place. Important laser parameters here are the wavelength of the laser, the pulse duration of the laser, the pulse energy of the laser and possibly also the polarization of the laser.


The following should preferably be provided for the interaction of the laser light with the material:


1) The wavelength l of the laser is preferably chosen such that the material is substantially transparent at this wavelength (specifically for example: absorption<<10% per mm of material depth ⇒γ<<1/cm; γ: Lambert-Beer absorption coefficient).


2) The pulse duration of the laser is preferably chosen such that no significant heat transport (heat diffusion) out of the zone of interaction can take place within the time of interaction (specifically for example: τ<<d2/α, d: focus diameter, τ: laser pulse duration, τ: heat diffusion constant of the material).


3) The pulse energy of the laser is preferably chosen such that the intensity in the zone of interaction, that is to say in the focal line, produces an induced absorption, which leads to local heating of the material along the focal line, which in turn leads to crack formation along the focal line as a result of the thermal stress introduced into the material.


4) The polarization of the laser influences both the interaction at the surface (reflectivity) and the type of interaction within the material in the induced absorption. The induced absorption may take place by way of induced, free charge carriers (typically electrons), either after thermal excitation, or by way of multiphoton absorption and internal photoionization, or by way of direct field ionization (field strength of the light breaks electron bonding directly). The type of generation of the charge carriers can be assessed for example by way of the so-called Keldysh parameter, which however does not play any role for the application of the method. In the case of certain materials (for example birefringent materials) it may just be important that the further absorption/transmission of the laser light depends on the polarization, and consequently the polarization by way of suitable optics (phase plates) should be chosen by the user to be conducive for separating the respective material, for example simply in a heuristic way. Therefore, if the material is not optically isotropic, but for example birefringent, the propagation of the laser light in the material is also influenced by the polarization. Thus, the polarization and the orientation of the polarization vector may be chosen such that, as desired, there only forms one focal line and not two (ordinary and extraordinary rays). In the case of optically isotropic materials, this does not play any role.


5) Furthermore, the intensity should be chosen on the basis of the pulse duration, the pulse energy and the focal line diameter such that there is preferably no significant ablation or significant melting, but preferably only crack formation in the microstructure of the solid body. For typical materials such as glass or transparent crystals, this requirement can be satisfied most easily with pulsed lasers in the sub-nanosecond range, that is to say in particular with pulse durations of for example between 10 and 100 ps. In this respect, also see FIG. 1: over scale lengths of approximately one micrometer (0.5 to 5.0 micrometers, cf. center of image), for poor heat conductors, such as glasses for example, the heat conduction acts into the sub-microsecond range (see the range between the two lines), while for good heat conductors, such as crystals and semiconductors, the heat conduction is already effective within nanoseconds.


The essential process for the crack formation in the material occurring, and made to extend vertically to the plane of the substrate, is mechanical stress that exceeds the structural strength of the material (compressive strength in MPa). The mechanical stress is achieved here by way of rapid, inhomogeneous heating (thermally induced stress) by the laser energy. Presupposing appropriate positioning of the substrate in relation to the focal line (see below), the crack formation starts of course at the surface of the substrate, since that is where the deformation is greatest. The reason for this is that in the half-space above the surface there is no material that can absorb forces. This argument also applies to materials with hardened or toughened surfaces, as long as the thickness of the hardened or toughened layer is great in comparison with the diameter of the abruptly heated material along the focal line. In this respect also see FIG. 2, further described below.


The type of interaction can be set by way of the fluence (energy density in Joules per cm2) and the laser pulse duration with a selected focal line diameter such that preferably 1.) no significant melting takes place at the surface or in the volume and 2.) no significant ablation with particle formation takes place at the surface. In the substantially transparent materials, several types of induced absorption are known:


a) In semiconductors and isolators with a low band gap, on the basis for example of a low residual absorption (due to traces of impurities in the material or due to charge carriers already thermally excited at the temperature before the laser machining), rapid heating up within a first fraction of the laser pulse duration will lead to thermal excitation of further charge carriers, which in turn leads to increased absorption and consequently to a cumulative increase in the laser absorption in the focal line.


b) In isolators, if there is sufficiently high light intensity, a photo absorption leads to an ionization on the basis of a nonlinear-optical interaction with the atoms of the material, and consequently in turn to the generation of free charge carriers, and consequently to increased linear absorption of the laser light.


The production of the geometry of a desired separating surface (relative movement between the laser beam and the substrate along a line on the substrate surface) is described below.


The interaction with the material produces for each laser pulse an individual, continuous (seen in the direction perpendicular to the substrate surface) crack zone in the material along a focal line. For the complete severing of the material, a series of these crack zones for each laser pulse is set so close together along the desired separating line that a lateral connection of the cracks produces a desired crack surface/contour in the material. For this, the laser is pulsed at a specific repetition rate. The spot size and spacing are chosen such that a desired, directed crack formation occurs at the surface, along the line of the laser spots. The spacing of the individual crack zones along the desired separating surface is obtained from the movement of the focal line in relation to the material within the time period from laser pulse to laser pulse. In this respect, also see FIG. 9, further described below.


To produce the desired separating surface in the material, either the pulsed laser light may be moved over the stationary material by an optical arrangement that is movable parallel to the plane of the substrate (and possibly also perpendicularly thereto), or the material itself is moved with a movable holder past the stationary optical arrangement such that the desired separating line is formed. The orientation of the focal line in relation to the surface of the material, whether perpendicular or at an angle of 90°−β to the surface, may either be chosen as a fixed value or be changed by way of a pivotable optical arrangement (hereinafter also referred to for simplicity as optics) and/or a pivotable beam path of the laser along the desired separating line.


Altogether, for forming the desired separating line, the focal line may be passed through the material in up to five separately movable axes: two spatial axes (x, y), which fix the point of penetration of the focal line into the material, two angular axes (theta, phi), which fix the orientation of the focal line from the point of penetration into the material, and a further spatial axis (z′, not necessarily orthogonal to x, y), which fixes how deep the focal line reaches into the material from the point of penetration at the surface. For the geometry in the Cartesian system of coordinates (x, y, z), also see for example FIGS. 5a and 6, described below. In the case of perpendicular incidence of the laser beam on the substrate surface (β=0°), then z=z'.


There are generally restrictions here, dictated by the optics and the laser parameters: the orientation of the angles in theta and phi can only take place to the extent that the refraction of the laser light in the material allows (less than the angle of total reflection in the material), and the depth of penetration of the laser focal line is restricted by the available laser pulse energy and the accordingly chosen laser optics, which only forms a length of the focal line that can produce the crack zone with the laser pulse energy available.


One possible configuration for moving the focal lines in all five axes may for example comprise moving the material on a driven axial table in the coordinates x, y, while by way of a galvoscanner and a non-telecentric F-theta lens the focal line is moved in the field of the lens in relation to the center of the lens in the coordinates x′, y′ and is tilted by the angles theta, phi. The coordinates x and x′ and y and y′ may be calculated such that the focal line is directed at the desired point of impingement of the surface of the material. The galvoscanner and F-theta lens are also fastened on a z axis, which is orthogonal to the x,y plane of the axial table and determines the position of the focal line perpendicularly to the material (depth of the focal line in the material).


The last step of separating the substrate into the multiple parts is described below (separation or individual separation).


The separation of the material along the crack surface/contour produced takes place either by internal stress of the material or by forces introduced, for example mechanically (tension) or thermally (uneven heating/cooling). Since, preferably, no significant amount of material is ablated, there is generally initially no continuous gap in the material, but only a highly disturbed fracture surface area (microcracks), which is meshed within itself and under some circumstances still connected by bridges. The forces subsequently introduced have the effect of separating the remaining bridges and overcoming the meshing by way of lateral crack growth (taking place parallel to the plane of the substrate), so that the material can be separated along the separating surface.


Additional embodiments of a method and of a device are described below.


In one embodiment, a method for the laser-based machining of a preferably sheet-like substrate (1), in particular a wafer or glass element, in order to separate the substrate into multiple parts, in which the laser beam (2a, 2b) of a laser (3) for machining the substrate (1) is directed onto the latter, is characterized in that with an optical arrangement (6) positioned in the path of rays of the laser (3), an extended laser beam focal line (2b), seen along the direction of the beam, is formed on the beam output side of the optical arrangement (6) from the laser beam (2a) directed onto the latter, the substrate (1) being positioned in relation to the laser beam focal line (2b) such that an induced absorption is produced in the material of the substrate (1) along an extended portion (2c), seen in the direction of the beam, of the laser beam focal line (2b), with the effect that an induced crack formation takes place in the material of the substrate along this extended portion (2c).


In some embodiments, the substrate (1) is positioned in relation to the laser beam focal line (2b) such that the extended portion (2c) of the induced absorption in the material, that is to say in the interior of the substrate (1), extends up to at least one of the two opposite substrate surfaces (1a, 1b).


In certain embodiments, the substrate (1) is positioned in relation to the laser beam focal line (2b) such that the extended portion (2c) of the induced absorption in the material, that is to say in the interior of the substrate (1), extends from one (1a) of the two opposite substrate surfaces up to the other (1b) of the two opposite substrate surfaces, that is to say over the entire layer thickness d of the substrate (1) or in that the substrate (1) is positioned in relation to the laser beam focal line (2b) such that the extended portion (2c) of the induced absorption in the material, that is to say in the interior of the substrate (1), extends from one (1a) of the two opposite substrate surfaces into the substrate (1), but not up to the other (1b) of the two opposite substrate surfaces, that is to say not over the entire layer thickness d of the substrate (1), preferably extends over 80% to 98%, preferably over 85 to 95%, particularly preferably over 90%, of this layer thickness.


In some embodiments, the induced absorption is produced such that the crack formation takes place in the microstructure of the substrate (1) without ablation and without melting of material of the substrate (1).


In certain embodiments, the extent l of the laser beam focal line (2b) and/or the extent of the portion (2c) of the induced absorption in the material, that is to say in the interior of the substrate (1), seen in each case in the longitudinal direction of the beam, is between 0.1 mm and 100 mm, preferably between 0.3 mm and 10 mm, and/or in that the layer thickness d of the substrate (1), measured perpendicularly to the two opposite substrate surfaces (1a, 1b), is between 30 μm and 3000 μm, preferably between 100 μm and 1000 μm, and/or in that the ratio V1=1/d of this extent l of the laser beam focal line (2b) and this layer thickness d of the substrate (1) is between 10 and 0.5, preferably between 5 and 2, and/or in that the ratio V2=L/D of the extent L of the portion (2c) of the induced absorption in the material, that is to say in the interior of the substrate (1), seen in the longitudinal direction of the beam, and the average extent D of the portion (2c) of the induced absorption in the material, that is to say in the interior of the substrate (1), seen transversely to the longitudinal direction of the beam, is between 5 and 5000, preferably between 50 and 500.


In some embodiments, the average diameter δ of the laser beam focal line (2b), that is to say the spot diameter, is between 0.5 μm and 5 μm, preferably between 1 μm and 3 μm, preferably is 2 μm, and/or in that the pulse duration τ of the laser (3) is chosen such that, within the time of interaction with the material of the substrate (1), the heat diffusion in this material is negligible, preferably no heat diffusion takes place, for which preferably τ, δ and the heat diffusion constant α of the material of the substrate (1) are set according to τ<<δ2/α and/or preferably τ is chosen to be less than 10 ns, preferably less than 100 ps, and/or in that the pulse repetition rate of the laser (3) is between 10 kHz and 1000 kHz, preferably is 100 kHz, and/or in that the laser (3) is operated as a single-pulse laser or as a burst-pulse laser, and/or in that the average laser power, measured directly on the output side of the beam of the laser (3), is between 10 watts and 100 watts, preferably between 30 watts and 50 watts.


In certain embodiments, the wavelength λ of the laser (3) is chosen such that the material of the substrate (1) is transparent to this wavelength or is substantially transparent, the latter being understood as meaning that the decrease in intensity of the laser beam taking place along the direction of the beam in the material of the substrate (1) per millimeter of the depth of penetration is 10% or less, the laser being, in particular for glasses or crystals that are transparent in the visible wavelength range as the substrate (1), preferably an Nd:YAG laser with a wavelength λ of 1064 nm or a Y:YAG laser with a wavelength λ of 1030 nm, or, in particular for semiconductor substrates (1) that are transparent in the infrared wavelength range, preferably an Er:YAG laser with a wavelength λ of between 1.5 μm and 1.8 μm.


In some embodiments, the laser beam (2a, 2b) is directed perpendicularly onto the substrate (1), in that therefore the substrate (1) is positioned in relation to the laser beam focal line (2b) such that the induced absorption along the extended portion (2c) of the laser beam focal line (2b) takes place perpendicularly to the plane of the substrate or in that the laser beam (2a, 2b) is directed onto the substrate (1) at an angle β of greater than 0° in relation to the normal to the plane of the substrate (1), in that therefore the substrate (1) is positioned in relation to the laser beam focal line (2b) such that the induced absorption along the extended portion (2c) of the laser beam focal line (2b) takes place at the angle 90°−β to the plane of the substrate, where preferably β≤45°, preferably β≤30°.


In certain embodiments, the laser beam (2a, 2b) is moved in relation to the surface (1a, 4) of the substrate (1) along a line (5) along which the substrate (1) is to be severed to obtain the multiple parts, a multiplicity (2c-1, 2c-2, . . . ) of extended portions (2c) of induced absorption in the interior of the substrate (1) being produced along this line (5), where preferably the ratio V3=α/δ of the average spacing a of directly adjacent extended portions (2c) of induced absorption, that is to say portions produced directly one after the other, and the average diameter δ of the laser beam focal line (2b), that is to say the spot diameter, is between 0.5 and 3.0, preferably between 1.0 and 2.0.


In some embodiments, during and/or after the production of the multiplicity (2c-1, 2c-2, . . . ) of extended portions (2c) of induced absorption in the interior of the substrate (1), mechanical forces are exerted on the substrate (1) and/or thermal stresses are introduced into the substrate (1), in particular the substrate is unevenly heated and cooled again, in order to bring about crack formation for separating the substrate into the multiple parts respectively between directly adjacent (2c-1, 2c-2) extended portions (2c) of induced absorption, the thermal stresses preferably being introduced by irradiating the substrate (1) with a CO2 laser along the line (5).


In some embodiments, a device for the laser-based machining of a preferably sheet-like substrate (1), in order to separate the substrate into multiple parts, with which the laser beam (2a, 2b) of a laser (3) for machining the substrate (1) can be directed onto the latter, is characterized by an optical arrangement (6), which is positioned in the path of rays of the laser (3) and with which an extended laser beam focal line (2b), seen along the direction of the beam, can be formed on the beam output side of the optical arrangement (6) from the laser beam (2a) directed onto the latter, the substrate (1) being able to be positioned or being positioned in relation to the laser beam focal line (2b) such that an induced absorption takes place in the material of the substrate (1) along an extended portion (2c), seen in the direction of the beam, of the laser beam focal line (2b), with the effect that an induced crack formation is brought about in the material of the substrate along this extended portion (2c).


In certain embodiments, the optical arrangement (6) comprises a focusing optical element with spherical aberration, preferably a spherically ground convex lens (7), a diaphragm (8) of the optical arrangement (6), preferably an annular diaphragm, preferably being positioned before this focusing optical element (7) in the path of rays of the laser (3), with the effect that the bundle of rays (2aZ) lying at the center of the laser beam (2a) impinging onto the diaphragm can be blocked out, so that only the peripheral rays (2aR) lying outside this center impinge onto this focusing optical element.


In some embodiments, the optical arrangement (6) comprises an optical element with a non-spherical free surface which is shaped for forming the laser beam focal line (2b) with a defined extent 1, that is to say a defined length, seen in the direction of the beam, the optical element with the non-spherical free surface preferably being a cone prism or an axicon (9).


In certain embodiments, the optical arrangement (6) comprises in the path of rays of the laser (3) firstly a first optical element with a non-spherical free surface, which is shaped for the forming of the extended laser beam focal line (2b), preferably a cone prism or an axicon (10), and, on the beam output side of this first optical element and at the distance z1 from it, a second, focusing optical element, in particular a convex lens (11), these two optical elements preferably being positioned and aligned such that the first optical element projects the laser radiation impinging on it annularly (SR) onto the second optical element, so that the extended laser beam focal line (2b) is produced on the beam output side of the second optical element at the distance z2 from it.


In some embodiments, a third, focusing optical element, which is in particular a plano-convex collimation lens (12), is positioned between the first and second optical elements in the path of rays of the laser (3), the third optical element preferably being positioned and aligned such that the laser radiation formed armularly (SR) by the first optical element falls onto the third optical element with a defined average ring diameter dr and in that the third optical element projects the laser radiation annularly with this ring diameter dr and with a defined ring width br onto the second optical element.


The methods or devices described above can be used for separating substrates of glass, in particular of quartz, borosilicate, sapphire or soda-lime glass, sodium-containing glass, hardened glass or unhardened glass, of crystalline Al2O3, of SiO2.nH2O (opal) or of a semiconductor material, in particular Si, GaAs, GaN, separating single- or multi-layered substrates, in particular glass-glass composites, glass-film composites, glass-film-glass composites or glass-air-glass composites, separating coated substrates, in particular metal-coated sapphire wafers, silicon wafers provided with metal or metal-oxide layers or substrates coated with ITO or AlZnO, and/or completely severing a single- or multi-layered substrate or severing one or more, but not all of the layers of a multi-layered substrate.


The laser beam focal line produced by means of the optical arrangement described above is alternatively also referred to above and below for simplicity as the focal line of the laser beam. The substrate is separated or individually separated into the multiple parts, seen in the plane of the substrate, by the crack formation (induced absorption along the focal line made to extend perpendicularly to the plane of the substrate). The crack formation consequently takes place perpendicularly to the plane of the substrate into the substrate or into the interior of the substrate (longitudinal crack formation). As already described, generally a multiplicity of individual laser beam focal lines have to be introduced into the substrate along a line on the substrate surface, in order that the individual parts of the substrate can be separated from one another. For this purpose, either the substrate may be made to move parallel to the plane of the substrate in relation to the laser beam or in relation to the optical arrangement or, conversely, the optical arrangement may be moved parallel to the plane of the substrate in relation to the fixedly arranged substrate.


The features of at least one of the dependent method or device claims are advantageously additionally realized. In this respect, the features of a number of dependent claims may also be realized in any desired combination.


In one particular aspect, the extended portion of the induced absorption in the interior of the substrate extends from a surface of the substrate to a defined depth of the substrate (or even beyond). The extended portion of the induced absorption may in this case comprise the entire depth of the substrate from one surface to the other. It is also possible to produce longitudinally extended portions of the induced absorption only in the interior of the substrate (without including the surfaces of the substrate).


Further features that can be advantageously realized can be seen in FIG. 3b further described below. The extended portion of the induced absorption (that is to say for example crack length introduced perpendicularly to the plane of the substrate) can consequently extend both from a point in the interior of the substrate along the extended portion of the induced absorption to the rear surface of the substrate or else for example from the front surfaces of the substrate to a point in the interior of the substrate. The layer thickness d is in this case respectively measured perpendicularly to the two opposite substrate surfaces of the sheet-like substrate (even in the case where the laser radiation is directed obliquely at an angle β>0° to the normal to the substrate surface, that is to say in the case of oblique incidence).


As used herein, the range limits mentioned in each case include the upper and lower limit values indicated.


The induced absorption is advantageously produced by means of the setting of the already described laser parameters, which are also explained below within the scope of examples, the parameters of the optical arrangement, and the geometrical parameters of the arrangement of the individual elements of the device. In principle, any desired combination of features of parameters is possible here. For instance, τ<<δ2/α means here that τ is less than 1%, preferably less than 1%, of δ2/α. For example, the pulse duration τ may be 10 ps (or else below that), between 10 and 100 ps or else above 100 ps. For separating Si substrates, preferably an Er:YAG laser with a wavelength of between 1.5 and 1.8 μm is used. For semiconductor substrates, generally a laser with a wavelength that is chosen such that the photon energy is less than the band gap of the semiconductor is preferably used. Advantageous radiating directions for directing the laser beam onto the substrate (which then also define the orientation of the laser beam focal line in relation to the plane of the substrate) include directing the laser beam (2a, 2b) perpendicularly onto the substrate (1), in that therefore the substrate (1) is positioned in relation to the laser beam focal line (2b) such that the induced absorption along the extended portion (2c) of the laser beam focal line (2b) takes place perpendicularly to the plane of the substrate, or directing the laser beam (2a, 2b) onto the substrate (1) at an angle β of greater than 0° in relation to the normal to the plane of the substrate (1), in that therefore the substrate (1) is positioned in relation to the laser beam focal line (2b) such that the induced absorption along the extended portion (2c) of the laser beam focal line (2b) takes place at the angle 90°−β to the plane of the substrate, where preferably β≤45°, preferably β≤30°.


The additional method steps that are possibly also necessary for the final separation or individual separation of the substrate into its multiple parts are described below. As already mentioned, either the substrate is moved in relation to the optical arrangement (together with the laser) or the optical arrangement (together with the laser) is moved in relation to the substrate. The crack formation should in this case (by contrast with the induced crack formation described above) be understood as meaning a transverse crack, that is to say a lateral crack formation in a direction lying in the plane of the substrate (corresponding to the path of the line along which the substrate is to be separated).


Further developments of a device, which describe in particular various possible configurational forms of the optical arrangement for producing and positioning the laser beam focal line, are described below. In this respect, also see the following exemplary embodiments and FIGS. 3a, 4, 5a, 5b, 6, 7 and 8. The convex lens may in particular be a plano-convex lens. Main uses according to the invention (others are also described below) are described above.


A series of significant advantages in comparison with the methods and devices that are known from the prior art are described below.


Firstly, according to the invention, the formation of the cut takes place without significant particle formation, without significant melt edges, with minimal crack formation at the edge, without any significant cutting gap (consequently without loss of material of the substrate) and with straight cut edges. The formation of the cut may in this case be set either perpendicularly (seen in relation to the plane of the substrate) or at an angle β desired by the user in relation to the normal to the substrate.


In particular, not a very high average laser power is necessary, but nevertheless comparatively high separating speeds can be achieved. It is essential in this respect that for each laser pulse (or each burst pulse) a laser beam focal line is produced (and not just a focal point of no extent, or only very local extent). The laser optics presented in further detail below are used for this purpose. The focal line thus determines the zone of interaction between the laser and the substrate. If the focal line falls at least as a portion thereof (seen in the depth direction) into the substrate material to be separated, the laser parameters can be chosen such that an interaction with the material which produces a crack zone along the entire focal line (or along the entire extended portion of the laser beam focal line that falls into the substrate) takes place. Selectable laser parameters are, for example, the wavelength of the laser, the pulse duration of the laser, the pulse energy of the laser and also possibly the polarization of the laser.


Further advantages that the method has in comparison for example with mechanical scoring and breaking are not only the absent (or at least minimal) particle formation but also, by contrast with a mechanical scoring line, that a high aspect ratio (width to depth) can be achieved. While in the case of mechanical scoring and breaking the rupture line into the material is produced by way of largely uncontrollable crack growth, according to the invention separation at a very precisely settable angle β to the normal to the substrate takes place. Consequently, according to the invention, there is no directional dependence of the cutting direction, and oblique cuts are readily possible.


Also in comparison with producing point (focused) defects by point focusing of a laser onto the surface or else into the interior of the substrate material and subsequent breaking after setting such point focuses at different depths of the material, embodiments described herein have in particular the advantage that a much higher aspect ratio of the cut can be achieved. Problems of such known methods that occur on account of scarcely directed crack formation, in particular in the case of thicker substrates, are consequently avoided. The machining speed is also increased by a multiple, in particular in the case of thicker substrates (in the case of which it is necessary to set at a defined position in the plane of the substrate multiple points of damage at different depths of the substrate, from the upper side to the underside of the substrate).


Ablation at the surface, flash formations at the surface and particle formations are avoided (the latter in particular if the position of the focal line in relation to the substrate is set such that the extended induced absorption and crack formation from the surface of the substrate is into the interior of the substrate). In this case, the first (wanted) damage consequently takes place directly at the surface and continues in a defined way along the crack formation zone into the depth of the substrate by induced absorption.


Various materials, in particular glass sheets, sapphire sheets, semiconductor wafers, . . . can be machined. In this respect, both individual layers of corresponding materials and laminates (stacks of multiple individual substrate layers) can be machined. The focal line may in this case be positioned and aligned such that, even in the interior of a stack of layers, only a defined layer is separated. Various sandwich structures of stacks of layers can be machined: glass-air-glass composites, glass-film-glass composites, glass-glass composites. Consequently, the selective cutting of individual layers even within a stack is possible, as is the severing of intermediate layers (for example films or adhesive film).


Already coated materials (for example AR coated, TCO coated) or else substrates non-transparently printed on one side can also be machined and separated.


Free-form cuts are possible, without the geometry being restricted by the crack formation in the substrate. Consequently, virtually any desired free-form cuts can be introduced into transparent media (the cutting direction is not direction-dependent). Consequently, oblique cuts can be introduced into the substrate, for example with angles of adjustment which, on the basis of the normal, have angles of up to β=30° or β=45°.


Cutting is possible virtually without any cutting gap: only material damage is produced, generally of an extent in the range between 1 and 10 μm. In particular, no cutting loss with respect to material or surface area is thereby generated. This is advantageous in particular when cutting semiconductor wafers, since cutting gap losses would reduce the actively usable surface area of the wafer. The method of focal line cutting described herein consequently produces an increased surface area yield. The absence of material loss is advantageous in particular also when cutting precious stones (for example diamond); though the area of use described herein is preferably the cutting or separating of sheet-like substrates, non-sheet-like substrates or workpieces can also be machined.


The method described herein may also be used in particular in the in-line operation of production processes. This takes place particularly advantageously in the case of production processes that proceed by a roll-to-roll method.


Single-pulse lasers may be used as well as lasers that generate burst pulses. In principle, the use of lasers in continuous-wave operation is also conceivable.


The following specific areas of application arise by way of example:


1. Separating sapphire LEDs with the possibility of fully or partially cutting the sapphire wafer. In this case, the metal layer may likewise be severed at the same time by the method described herein, doing so in a single step.


2. The individual separation of semiconductor wafers is possible without damaging the tape. For this purpose, the focal line is only partially taken into the interior of the substrate material, so that it begins at the surface and stops before the taped film (on the rear surface of the substrate that is facing away from the laser): for example, about 10% of the material is not separated. The film consequently remains intact because the focal line “stops” before the film. The semiconductor wafer can then subsequently be separated over the remaining 10% by way of mechanical forces (or thermal forces, see the following example with the CO2 laser).


3. Cutting of coated materials: examples here are Bragg reflectors (DBR) or else metal-coated sapphire wafers. Processed silicon wafers, to which the active metal or metal-oxide layers have already been applied, can also be cut according to the invention. Other examples are the machining of ITO or AlZnO, by which substrates that are required for example for producing touchscreens or smart windows are coated. On account of the very extended focal line (in comparison with its diameter), part of the focal line will remove the metal layer (or another layer), while the rest of the focal line penetrates into the transparent material and cuts it. This also has the advantage in particular that correspondingly coated substrates can be separated in a one-step process, that is to say in a process in which the coating and the substrate are separated in one operation.


4. The cutting of very thin materials (for example substrates of glass with thicknesses of less than 300 μm, less than 100 μm or even less than 50 μm) is particularly advantageous. These materials can only be machined very laboriously by conventional mechanical methods. Indeed, in the case of the mechanical methods, edges, damage, cracks or spalling occur, which either make the substrates unusable or necessitate laborious re-working operations. By contrast, in the case of thin materials, the cutting described herein offers the advantages in particular of avoiding edge damage and cracks, so that no re-working is necessary, of very high cutting speeds (>1 m/s), of a high yield and of carrying out the process in a single step.


5. The method described herein can also be used in particular in the production of thin film glasses, which are produced by a continuously running glass-pulling process, for trimming the edges of the film.



FIG. 2 diagrammatically shows the basic procedure of the machining method according to the invention. A laser beam 2, which is emitted by the laser 3 not shown here (see FIG. 7) and is denoted on the beam input side of the optical arrangement 6 by the reference sign 2a, is directed onto the optical arrangement 6 (see the following exemplary embodiments of this). The optical arrangement 6 forms from the radiated-in laser beam on the beam output side an extended laser beam focal line 2b over a defined range of extent along the direction of the beam (length l of the focal line). The substrate 1 to be machined, here a sheet-like substrate 1, is positioned after the optical arrangement in the path of rays, at least a portion thereof coinciding with the laser beam focal line 2b of the laser radiation 2. The reference sign 1a denotes the surface of the sheet-like substrate that is facing the optical arrangement 6 or the laser, the reference sign 1b denotes the rear surface 1b of the substrate 1, at a distance from and usually parallel to said first surface. The substrate thickness (perpendicularly to the surfaces 1a and 1b, that is to say measured in relation to the plane of the substrate) is denoted here by the reference sign d.


As FIG. 2a shows, here the substrate 1 is aligned perpendicularly to the longitudinal axis of the beam and consequently to the focal line 2b produced by the optical arrangement 6 in space downstream of the same (the substrate is perpendicular to the plane of the drawing) and, seen along the direction of the beam, positioned in relation to the focal line 2b such that, seen in the direction of the beam, the focal line 2b begins before the surface 1a of the substrate and ends before the surface 1b of the substrate, that is to say still within the substrate. Consequently (with suitable laser intensity along the laser beam focal line 2b, which is ensured by the focusing of the laser beam 2 on a portion of the length l, that is to say by a line focus of the length l), the extended laser beam focal line 2b produces in the region of coincidence of the laser beam focal line 2b with the substrate 1, that is to say in the material of the substrate that is passed over by the focal line 2b, an extended portion 2c, seen along the longitudinal direction of the beam, along which an induced absorption is produced in the material of the substrate, which induces a crack formation in the material of the substrate along the portion 2c. The crack formation takes place in this case not only locally but over the entire length of the extended portion 2c of the induced absorption. The length of this portion 2c (that is to say ultimately the length of the coincidence of the laser beam focal line 2b with the substrate 1) is provided here with the reference sign L. The average diameter or the average extent of the portion of the induced absorption (or of the regions in the material of the substrate 1 that are subjected to the crack formation) is denoted here by the reference sign D. This average extent D corresponds here substantially to the average diameter δ of the laser beam focal line 2b.


As FIG. 2a shows, consequently, substrate material that is transparent to the wavelength λ of the laser beam 2 is heated by induced absorption along the focal line 2b. FIG. 2b diagrammatically shows how the heated material ultimately expands, so that a correspondingly induced stress leads to the microcrack formation, the stress being greatest at the surface 1a.


Actual optical arrangements 6 that can be used for producing the focal line 2b, and also an actual optical setup (FIG. 7), in which these optical arrangements can be used, are described below. All of the arrangements and setups are based here on the descriptions given above, so that identical reference signs are used in each case for components or features that are identical or correspond in their function. Therefore, only the differences are respectively described below.


Since the separating surface ultimately leading to the separation is, or is intended to be, of high-quality (with regard to rupture strength, the geometrical precision, roughness and the avoidance of re-working requirements), the individual focal lines to be positioned along the separating line 5 on the surface of the substrate should be produced as described with the following optical arrangements (the optical arrangement is alternatively also referred to hereinafter as laser optics). The roughness results here in particular from the spot size or the spot diameter of the focal line. In order with a given wavelength λ of the laser 3 (interaction with the material of the substrate 1) to be able to achieve a small spot size, of for example 0.5 μm to 2 μm, generally certain requirements have to be imposed on the numerical aperture of the laser optics 6. These requirements are satisfied by the laser optics 6 described below.


To achieve the desired numerical aperture, on the one hand the optics must have the necessary aperture at a given focal length, according to the known formulae given by Abbé (N.A.=n sin(theta), n: refractive index of the glass to be machined, theta: half the angular aperture; and theta=arctan(D/2f); D: aperture, f: focal length). On the other hand, the laser beam must illuminate the optics up to the necessary aperture, which is typically accomplished by beam expansion by means of expansion telescopes between the laser and the focusing optics. The spot size should at the same time not vary too much, for a uniform interaction along the focal line. This can be ensured for example (see exemplary embodiment below) by the focusing optics only being illuminated in a narrow, annular region, in that then of course the beam aperture, and consequently the numerical aperture, change only by a small amount in percentage terms.


According to FIG. 3a (section perpendicularly to the plane of the substrate at the height of the central ray in the bundle of laser rays of the laser radiation 2; here, too, the radiating in of the laser beam 2 takes place perpendicularly to the plane of the substrate, i.e. the angle β is 0°, so that the focal line 2b or the extended portion of the induced absorption 2c is parallel to the normal to the substrate), the laser radiation 2a emitted by the laser 3 is initially directed onto a circular diaphragm 8, which is completely nontransparent to the laser radiation used. The diaphragm 8 is in this case oriented perpendicularly to the longitudinal axis of the beam and centered on the central ray of the bundle of rays 2a shown. The diameter of the diaphragm 8 is chosen such that the bundles of rays lying close to the center of the bundle of rays 2a or the central ray (denoted here by 2aZ) impinge on the diaphragm and are completely absorbed by it. Only rays lying in the outer peripheral region of the bundle of rays 2a (peripheral rays, denoted here by 2aR) are not absorbed on account of the reduced diaphragm size in comparison with the beam diameter, but pass by the diaphragm 8 laterally and impinge on the peripheral regions of the focusing optical element of the optical arrangement 6, formed here as a spherically ground, biconvex lens 7.


The lens 7, centered on the central ray, is deliberately formed here as a non-corrected, biconvex focusing lens in the form of a customary spherically ground lens. In other words, the spherical aberration of such a lens is deliberately utilized. As an alternative to this, aspheric lenses or multilens systems that deviate from ideally corrected systems and specifically do not form an ideal focal point but a definite, elongated focal line of a defined length may also be used (that is to say lenses or systems that specifically no longer have a single focal point). The zones of the lens consequently focus specifically in dependence on the distance from the center of the lens along a focal line 2b. Here, the diameter of the diaphragm 8 transversely to the direction of the beam is approximately 90% of the diameter of the bundle of rays (the diameter of the bundle of rays is defined by the extent up to decay to 1/e) and about 75% of the diameter of the lens of the optical arrangement 6. Consequently, the focal line 2b of a non-aberration-corrected spherical lens 7 that has been produced by blocking out the bundle of rays in the middle is used herein. The section in a plane through the central ray is represented; the complete three-dimensional bundle is obtained when the rays represented are rotated about the focal line 2b.


A disadvantage of this focal line is that the conditions (spot size, intensity of the laser) change along the focal line, and consequently along the desired depth in the material, and consequently the desired type of interaction (no significant melting, induced absorption, thermal-plastic deformation up to crack formation) can possibly only be set within part of the focal line. This conversely means that possibly only part of the radiated-in laser light is absorbed in the way desired. Consequently, on the one hand the efficiency of the method (necessary average laser power for the desired separating speed) is impaired, on the other hand under some circumstances laser light is transmitted to undesired, deeper-lying locations (parts or layers adhering to the substrate, or to the substrate holder) and interacts there in an undesired way (heating, dispersion, absorption, undesired modification).



FIG. 3b shows (not only for the optical arrangement in FIG. 3a, but in principle also for all other optical arrangements 6 that can be used) that the laser beam focal line 2b can be positioned variously by suitable positioning and/or alignment of the optical arrangement 6 in relation to the substrate 1 and by suitable choice of the parameters of the optical arrangement 6: as the first line from FIG. 3b diagrammatically shows, the length l of the focal line 2b may be set such that it exceeds the substrate thickness d (here by a factor of 2). Consequently, if the substrate 1 is placed centrally in relation to the focal line 2b, seen in the longitudinal direction of the beam, an extended portion of induced absorption 2c is produced over the entire substrate thickness d.


In the case shown in the second line in FIG. 3b, a focal line 2b of the length l that corresponds approximately to the extent of the substrate d is produced. Since the substrate 1 is positioned in relation to the line 2 such that the line 2b begins at a point before, that is to say outside, the substrate, the length L of the extended portion of induced absorption 2c (which extends here from the surface of the substrate to a defined depth of the substrate, but not as far as the rear surface 1b) is less here than the length l of the focal line 2b. The third line in FIG. 3b shows the case in which the substrate 1 is positioned partially before the beginning of the focal line 2b, seen along the direction of the beam, so that here, too, l>L applies for the length l of the line 2b (L=extent of the portion of induced absorption 2c in substrate 1). The focal line consequently begins in the interior of the substrate and extends beyond the rear surface 1b to outside the substrate. The fourth line in FIG. 3b finally shows the case in which the focal line length l produced is less than the substrate thickness d, so that—with central positioning of the substrate in relation to the focal line seen in the direction of irradiation—the focal line begins here close to the surface 1a in the interior of the substrate and ends close to the surface 1b in the interior of the substrate (l=0.75·d).


It is particularly advantageous here to realize the focal line positioning such that at least one of the surfaces 1a, 1b is passed over by the focal line; the portion of the induced absorption 2c consequently begins at at least one surface. In this way, virtually ideal cuts can be achieved by avoiding ablation, flash and particle formation at the surface.



FIG. 4 shows a further optical arrangement 6 that can be used. The basic setup follows that described in FIG. 3a, so that only the differences are described below. The optical arrangement shown is based on the idea of using optics with a non-spherical free surface which is shaped such that a focal line of a defined length l is formed for the formation of the focal line 2b. For this purpose, aspheric lenses may be used as optical elements of the optical arrangement 6. For example, in FIG. 4, a so-called cone prism, which is often also referred to as an axicon, is used. An axicon is a special, conically ground lens that forms a point source on a line along the optical axis (or else annularly transforms a laser beam). The setup of such an axicon is known in principle to a person skilled in the art. Here, the cone angle is for example 10°. The axicon denoted here by the reference sign 9 is aligned with its cone tip counter to the direction of irradiation and centered on the center of the beam. Since the focal line 2b of the axicon 9 already begins within the same, the substrate 1 (which is arranged here perpendicularly to the axis of the principal ray) may be positioned in the path of rays directly after the axicon 9. As FIG. 4 shows, on account of the optical properties of the axicon, a displacement of the substrate 1 along the direction of the beam is also possible without it leaving the region of the focal line 2b. The extended portion of the induced absorption 2c in the material of the substrate 1 consequently extends over the entire substrate depth d.


However, the setup shown has the following restrictions: since the focal line of the axicon 9 already begins within the lens, with a finite working distance between the lens and the material, a significant part of the laser energy is not focused into the part 2c of the focal line 2b that lies in the material. Furthermore, with the available refractive index and cone angles of the axicon 9, the length l of the focal line 2b is linked to the beam diameter, for which reason, in the case of relatively thin materials (a few millimeters), the focal line is altogether too long, as a result of which in turn the laser energy cannot be specifically focused into the material.


For this reason, an improved optical arrangement 6 is obtained if it comprises both an axicon and a focusing lens. FIG. 5a shows such an optical arrangement 6, in which there is positioned on the path of rays of the laser 3, seen along the direction of the beam, firstly a first optical element with a non-spherical free surface, which is shaped for the forming of an extended laser beam focal line 2b. In the case shown, this first optical element is an axicon 10 with a 5° cone angle, which is positioned perpendicularly to the direction of the beam and centered on the laser beam 3. The cone tip of the axicon in this case points counter to the direction of the beam. Positioned at the distance z1 from the axicon 10 in the direction of the beam is a second, focusing optical element, here a plano-convex lens 11 (the convexity of which faces toward the axicon). The distance z1 is chosen here to be about 300 mm, such that the laser radiation formed by the axicon 10 impinges in an annular manner on the outer regions of the lens 11. The lens 11 focuses the annularly impinging radiation on the beam output side onto a focal line 2b of a defined length, of here 1.5 mm, at the distance z2, of here about 20 mm, from the lens 11. Here, the effective focal length of the lens 11 is 25 mm. The annular transformation of the laser beam by the axicon 10 is provided here with the reference sign SR.



FIG. 5b shows in detail the formation of the focal line 2b and of the induced absorption 2c in the material of the substrate 1 according to FIG. 5a. The optical properties of the two elements 10, 11 and the positioning of the same here are such that the extent l of the focal line 2b in the direction of the beam coincides exactly with the thickness d of the substrate 1. Accordingly, an exact positioning of the substrate 1 along the direction of the beam is necessary in order to position the focal line 2b exactly between the two surfaces 1a and 1b of the substrate 1, as shown in FIG. 5b.


It is consequently advantageous if the focal line is formed at a certain distance from the laser optics, and the large part of the laser radiation is focused up to a desired end of the focal line. As described, this can be achieved by a mainly focusing element 11 (lens) only being illuminated annularly on a desired zone, whereby on the one hand the desired numerical aperture is realized, and consequently the desired spot size, but on the other hand, after the desired focal line 2b, the circle of least diffusion loses intensity after a very short distance in the middle of the spot, since a substantially annular spot forms. Consequently, the crack formation is stopped within a short distance at the desired depth of the substrate. A combination of the axicon 10 and the focusing lens 11 satisfies this requirement. Here, the axicon 10 acts in two ways: a usually round laser spot is sent by the axicon 10 annularly onto the focusing lens 11 and the asphericity of the axicon 10 has the effect that, instead of a focal point in the focal plane of the lens, a focal line forms outside the focal plane. The length l of the focal line 2b can be set by way of the beam diameter on the axicon. The numerical aperture along the focal line can in turn be set by way of the distance z1 between the axicon and the lens and by way of the cone angle of the axicon. In this way, the entire laser energy can consequently be concentrated in the focal line.


If the crack formation is intended to stop before the exit side of the substrate, the annular illumination still has the advantage that on the one hand the laser power is used in the best possible way, since a large part of the laser light remains concentrated in the desired length of the focal line, on the other hand, due to the annular illuminated zone together with the desired aberration set by the other optical functions, a uniform spot size along the focal line can be achieved, and consequently a uniform separating process along the focal line can be achieved.


Instead of the plano-convex lens shown in FIG. 5a, a focusing meniscus lens or some other higher corrected focusing lens (aspheric lens, multilens system) may also be used.


To produce very short focal lines 2b with the combination shown in FIG. 5a of an axicon and a lens, very small beam diameters of the laser beam incident on the axicon would have to be chosen. This has the practical disadvantage that the centering of the beam on the tip of the axicon must be very exact, and therefore the result is very sensitive to directional fluctuations of the laser (beam drift stability). Furthermore, a narrowly collimated laser beam is very divergent, i.e. the bundle of rays scatters again over short distances on account of the diffraction of light.


Both can be avoided by inserting a further lens, a collimation lens 12 (FIG. 6): this further positive lens 12 allows the annular illumination of the focusing lens 11 to be set very narrowly. The focal length f of the collimation lens 12 is chosen such that the desired ring diameter dr is obtained when there is a distance z1a from the axicon to the collimation lens 12 that is equal to f′. The desired width br of the ring can be chosen by way of the distance z1b (collimation lens 12 to focusing lens 11). Purely geometrically, a short focal line then follows from the small width of the annular illumination. A minimum is in turn achieved at the distance f′.


The optical arrangement 6 shown in FIG. 6 is consequently based on that shown in FIG. 5a, so that only the differences are described below. In addition, the collimation lens 12, which is likewise formed here as a plano-convex lens (with its convexity pointing counter to the direction of the beam), has been introduced here centrally into the path of rays between the axicon 10 (which is arranged here with its cone tip counter to the direction of the beam) on the one hand and the plano-convex lens 11 on the other hand. The distance of the collimation lens 12 from the axicon 10 is denoted here by z1a, the distance of the focusing lens 11 from the collimation lens 12 is denoted by z1b and the distance of the focal line 2b produced from the focusing lens 11 is denoted by z2 (seen in each case in the direction of the beam). As FIG. 6 shows, the annular radiation SR that is formed by the axicon and incident upon the collimation lens 12 in a divergent manner and with the ring diameter dr, has the ring diameter dr remaining at least approximately constant along the distance z1b and is set to the desired ring width br at the location of the focusing lens 11. In the case shown, a very short focal line 2b is intended to be produced, so that the ring width br of about 4 mm at the location of the lens 12 is reduced by the focusing properties of the latter at the location of the lens 11 to about 0.5 mm (ring diameter dr here for example 22 mm).


In the example represented, with a typical beam diameter from the laser of 2 mm, with a focusing lens 11 of f=25 mm focal length and a collimation lens of f′=150 mm focal length, a length of the focal line l of below 0.5 mm can be achieved. Furthermore, Z1a=Z1b=140 mm and Z2=15 mm.


An example of the severing of unhardened glass with an optical arrangement according to FIG. 3a in a setup according to FIG. 7 is given below (instead of the optical arrangement 6 shown in FIG. 3a, the other optical arrangements 6 described above may also be used in the setup according to FIG. 7, in that the diaphragm-lens combination 8, 7 shown there is correspondingly replaced).


Borosilicate or soda-lime glasses 1 without other colorations (in particular with a low iron content) are optically transparent from about 350 nm to about 2.5 μm. Glasses are generally poor heat conductors, for which reason even laser pulse durations of a few nanoseconds do not allow any significant heat diffusion out of a focal line 2b. Nevertheless, even shorter laser pulse durations are advantageous, since with sub-nanosecond or picosecond pulses a desired induced absorption can be achieved more easily by way of non-linear effects (intensity much higher).


Suitable for example for severing flat glasses is a commercially available picosecond laser 3, which has the following parameters: wavelength 1064 nm, pulse duration of 10 picoseconds, pulse repetition rate of 100 kHz, average power (measured directly after the laser) of up to 50 W. The laser beam initially has a beam diameter (measured at 13% of the peak intensity, i.e. 1/e2 diameter of a Gaussian bundle of rays) of about 2 mm, the beam quality is at least M2<1.2 (determined in accordance with DIN/ISO 11146). With beam expanding optics 22 (commercially available Kepler beam telescope), the beam diameter is increased by a factor of 10 to about 20-22 mm (21, 23, 24 and 25 are beam-deflecting mirrors). With a so-called annular diaphragm 8 of 9 mm in diameter, the inner part of the bundle of rays is cut off, so that an annular beam forms. With this annular beam, a plano-convex lens 7 with a 28 mm focal length (quartz glass with a radius of 13 mm) is illuminated for example. The strong (desired) spherical aberration of the lens 7 has the effect of producing the focal line. See in this respect not only FIG. 7 but also FIG. 8, which diagrammatically shows the production of the focal line 2b from the peripheral rays by the lens 7.


The theoretical diameter δ of the focal line varies along the axis of the beam, and is therefore advantageous for producing a homogeneous crack surface if the substrate thickness d here is smaller than about 1 mm (typical thicknesses for display glasses are 0.5 mm to 0.7 mm). A spot size of about 2 μm and a spacing from spot to spot of 5 μm give a speed at which the focal line can be passed 5 over the substrate 1 (see FIG. 9) of 0.5 m/sec. With an average power on the substrate of 25 W (measured after the focusing lens 7), the pulse repetition rate of 100 kHz gives a pulse energy of 250 μJ, which may also take place in a structured pulse (rapid sequence of single pulses at intervals of only 20 ns, known as a burst pulse) of 2 to 5 sub-pulses.


Unhardened glasses have substantially no internal stresses, for which reason, without any external action, the zone of disturbance, which is still interlinked and connected by unseparated bridges, at first still holds the parts together here. If, however, a thermal stress is introduced, the substrate separates completely, and without any further force being introduced externally, along the lasered rupture surface 5. For this purpose, a CO2 laser with an average power of up to 250 W is focused onto a spot size of about 1 mm, and this spot is passed over the separating line 5 at up to 0.5 m/s. The local thermal stress due to the laser energy introduced (5 J per cm of the separating line 5) separates the workpiece 1 completely.


For separating thicker glasses, the threshold intensity for the process (induced absorption and formation of a zone of disturbance by thermal shock) must of course be reached over a longer focal line 1. Higher necessary pulse energies and higher average power outputs consequently follow. With the optics setup described above and the maximum laser power available (after losses through optics) of 39 W on the substrate, the severing of glass about 3 mm thick is successfully achieved. In this case, on the one hand the annular diaphragm 8 is removed, and on the other hand the distance of the lens 7 from the substrate is corrected (increased in the direction of nominal focal distance) such that a longer focal line is produced in the substrate.


A further exemplary embodiment of severing hardened glass (likewise with the device shown in FIGS. 3a and 7) is presented below.


Sodium-containing glasses are hardened, in that sodium is exchanged for potassium at the surface of the glass by immersion in baths of liquid potassium salt. This leads to a considerable internal stress (compressive stress) in a layer 5-50 μm thick at the surfaces, which in turn leads to the greater stability.


In principle, the process parameters when severing hardened glasses are similar to those for unhardened glasses of comparable dimensions and composition. However, the hardened glass can break very much more easily due to the internal stress, specifically due to undesired crack growth, which does not take place along the lasered intended rupture surface 5, but into the material. Therefore, there is a narrower parameter field for the successful severing of a specific hardened glass. In particular, the average laser power and the associated cutting speed must be maintained very precisely, specifically in dependence on the thickness of the hardened layer. For a glass with a hardened layer 40 μm thick and a total thickness of 0.7 mm, the following parameters are obtained for example in the case of the aforementioned setup: a cutting speed of 1 m/s at a pulse repetition rate of 100 kHz, and therefore a spot spacing of 10 μm, with an average power of 14 W.


The internal stress of the hardened glasses has the effect that the rupture zone 5 forms completely after a little time (a few seconds), and the substrate is separated into the desired parts.


Very thin hardened glasses (<100 μm) consist predominantly of toughened material, i.e. the front and rear sides are reduced in their sodium content, and consequently hardened, in each case by for example 30 μm, and only 40 μm in the interior are unhardened. This material breaks very easily and completely if one of the surfaces is damaged. It has so far not been possible in the prior art for such hardened glass films to be machined.


The severing of this material by the method described herein is successfully achieved if a) the diameter of the focal line is very small, for example less than 1 μm, b) the spacing from spot to spot is small, for example between 1 and 2 μm, and c) the separating speed is high enough for the crack growth not to get ahead of the laser process (high laser pulse repetition rate of for example 200 kHz at 0.2 to 0.5 m/s).


A further exemplary embodiment (likewise with the device described in FIGS. 3a and 7) for severing sapphire glass and crystalline sapphire is presented below.


Sapphire crystals and sapphire glasses are glasses which, though optically similar (transparency and refractive index), behave very differently mechanically and thermally. For instance, sapphire is an excellent heat conductor, can withstand extreme mechanical loading and is very hard and scratch-resistant. Nevertheless, with the laser and optics setup described above, thin (0.3 mm to 0.6 mm) sapphire crystals and glasses can be severed. Because of the great mechanical stability, it is particularly important that the remaining bridges between the parts to be separated are minimized, since otherwise very high forces are required for ultimate separation. The zone of disturbance must be formed as completely as possible from the entry surface 1a to the exit surface 1b of the substrate. As in the case of thicker glasses, this can be achieved with higher pulse energy, and consequently higher average laser power. Furthermore, crystalline sapphire is birefringent. The cutting surface must lie perpendicularly to the optical axis (so-called C-cut). For severing a crystalline sapphire wafer of 0.45 mm in thickness, the following parameters can be used: an average laser power of 30 W at a pulse repetition rate of 100 kHz, a spot size of 2 μm, and a spot spacing of 5 μm, which corresponds to a cutting speed of 0.5 m/s at the pulse repetition rate mentioned. As in the case of glass, complete separation may require subsequent heating of the cutting line 5 to be carried out, for example with a CO2 laser spot, in order that the thermal stress is used to make the zone of disturbance go through crack growth to form a complete, continuous, non-interlinked separating surface.



FIG. 9 finally shows a micrograph of the surface of a glass sheet machined as described herein. The individual focal lines or extended portions of induced absorption 2c, which are provided here with the reference signs 2c-1, 2c-2 . . . (into the depth of the substrate perpendicularly to the surface represented), are joined together along the line 5, along which the laser beam has been passed over the surface 4 of the substrate, by crack formation to form a separating surface for the separation of the parts of the substrate. The multiplicity of individual extended portions of induced absorption can be seen well, in the case shown the pulse repetition rate of the laser having been made to match the rate of the advancement for moving the laser beam over the surface 4 such that the ratio V3=α/δ of the average spacing a of directly adjacent portions 2c-1, 2, 2c-2 . . . and the average diameter δ of the laser beam focal line is approximately 2.0.


Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that any particular order be inferred.


The teachings of all patents, published applications and references cited herein are incorporated by reference in their entirety.


It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the invention. Since modifications combinations, sub-combinations and variations of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and their equivalents.

Claims
  • 1. A method of laser processing an ion-exchangeable glass workpiece, the method comprising: focusing a pulsed laser beam into a laser beam focal line oriented along a beam propagation direction and directed into the ion-exchangeable glass workpiece, the laser beam focal line generating an induced absorption within the ion-exchangeable glass workpiece, the induced absorption producing a defect line along the laser beam focal line within the ion-exchangeable glass workpiece; andtranslating at least one of the ion-exchangeable glass workpiece and the pulsed laser beam relative to each other along a contour, thereby laser forming a plurality of defect lines along the contour within the ion-exchangeable glass workpiece, wherein a spatial periodicity between the adjacent defect lines is from 0.25 microns to 15 microns.
  • 2. The method of claim 1, wherein a pulsed laser produces pulse bursts with at least 2 pulses per pulse burst.
  • 3. The method of claim 1, wherein a pulsed laser has a laser power of 10 W-150 W and produces pulse bursts with 2-25 pulses per pulse burst.
  • 4. The method of claim 2, wherein a pulsed laser has laser power of 10 W-100 W and at least one of the ion-exchangeable glass workpiece and the pulsed laser beam are translated relative to one another at a rate of at least 0.5 m/sec.
  • 5. The method of claim 1, wherein the spatial periodicity is between 2 micron and 12 microns.
  • 6. The method of claim 1, further comprising separating the ion-exchangeable glass workpiece along the contour.
  • 7. The method of claim 6, wherein separating the ion-exchangeable glass workpiece along the contour includes directing a carbon dioxide laser into the ion-exchangeable glass workpiece along or near the contour to facilitate separation of the ion-exchangeable glass workpiece along the contour.
  • 8. The method of claim 6, wherein the ion-exchangeable glass workpiece comprises pre-ion exchange glass and the method further comprises applying an ion-exchange process to the pre-ion exchange glass workpiece after separation.
  • 9. The method of claim 1, wherein the ion-exchangeable glass workpiece comprises a stack of plural ion-exchangeable glass substrates.
  • 10. The method of claim 9, wherein the defect line extends through each of the plural ion-exchangeable glass substrates.
  • 11. The method of claim 9, wherein at least two of the plural ion-exchangeable glass substrates are separated by an air gap.
  • 12. The method of claim 1, wherein a pulse duration of the pulsed laser beam is in a range of from 10 picosecond to 100 picoseconds.
  • 13. The method of claim 1, wherein a repetition rate of the pulsed laser beam is in a range of from 10 kHz to 1000 kHz.
  • 14. The method of claim 1, wherein pulses of the pulsed laser beam are produced in bursts of at least two pulses separated by a duration in a range of from 1 nsec to 50 nsec, and the burst repetition frequency is in a range of from 1 kHz to 650 kHz.
  • 15. The method of claim 14, wherein the pulses are separated by a duration of 20 nsec.
  • 16. The method of claim 1, wherein the pulsed laser beam has a wavelength selected such that the ion-exchangeable glass workpiece is substantially transparent at this wavelength.
  • 17. The method of claim 1, wherein the laser beam focal line has a length in a range of from 0.1 mm to 100 mm.
  • 18. The method of claim 17, wherein the laser beam focal line has a length in a range of from 0.1 mm to 10 mm.
  • 19. The method of claim 1, wherein the laser beam focal line has an average spot diameter in a range of from 0.5 micron to 5 microns.
  • 20. The method of claim 1, wherein the ion-exchangeable glass workpiece and the pulsed laser beam are translated relative to each other at a speed in a range of from 1 mm/sec to 3400 mm/sec.
Priority Claims (1)
Number Date Country Kind
13151296 Jan 2013 EP regional
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 14/761,275, filed on Jul. 15, 2015, which itself claims the benefit of priority under 35 U.S.C. § 371 of International Application Serial No. PCT/EP14/050610, filed on Jan. 14, 2014, which, in turn, claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Ser. No. 61/752,489 filed on Jan. 15, 2013, and claims priority under 35 U.S.C. § 119 or 365 to European Application No. EP 13 151 296, filed Jan. 15, 2013, the contents of which are each relied upon and incorporated herein by reference in its entirety.

US Referenced Citations (593)
Number Name Date Kind
1529243 Drake et al. Mar 1925 A
1626396 Drake Apr 1927 A
1790397 Woods et al. Jan 1931 A
2682134 Stanley Jun 1954 A
2749794 Thomas Jun 1956 A
2754956 Sommer Jul 1956 A
3647410 Heaton et al. 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 et al. Oct 1985 A
4618056 Cutshall Oct 1986 A
4623776 Buchroeder et al. Nov 1986 A
4642439 Miller et al. Feb 1987 A
4646308 Kafka et al. Feb 1987 A
4764930 Bille et al. Aug 1988 A
4891054 Bricker et al. Jan 1990 A
4907586 Bille et al. Mar 1990 A
4918751 Pessot et al. Apr 1990 A
4929065 Hagerty et al. May 1990 A
4951457 Deal Aug 1990 A
4997250 Ortiz, Jr. Mar 1991 A
5035918 Vyas Jul 1991 A
5040182 Spinelli et al. Aug 1991 A
5104210 Tokas Apr 1992 A
5104523 Masaharu et al. Apr 1992 A
5108857 Kitayama et al. Apr 1992 A
5112722 Tsujino et al. May 1992 A
5114834 Nachshon May 1992 A
5221034 Bando Jun 1993 A
5256853 McIntyre Oct 1993 A
5265107 Delfyett Nov 1993 A
5326956 Lunney Jul 1994 A
5400350 Galvanauskas Mar 1995 A
5410567 Brundage et al. Apr 1995 A
5434875 Rieger et al. Jul 1995 A
5436925 Lin et al. Jul 1995 A
5475197 Wrobel et al. Dec 1995 A
5541774 Blankenbecler Jul 1996 A
5553093 Ramaswamy et al. Sep 1996 A
5574597 Kataoka Nov 1996 A
5586138 Yokoyama Dec 1996 A
5656186 Mourou et al. Aug 1997 A
5676866 In Den Baumen et al. Oct 1997 A
5684642 Zumoto Nov 1997 A
5692703 Murphy et al. Dec 1997 A
5696782 Harter et al. Dec 1997 A
5715346 Liu Feb 1998 A
5736709 Neiheisel Apr 1998 A
5776220 Allaire et al. 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 et al. Jan 2000 A
6016324 Rieger et al. Jan 2000 A
6027062 Bacon et al. Feb 2000 A
6033583 Musket et al. Mar 2000 A
6038055 Hansch et al. Mar 2000 A
6055829 Witzmann et al. May 2000 A
6078599 Everage et al. Jun 2000 A
6137632 Bernacki Oct 2000 A
6156030 Neev Dec 2000 A
6160835 Kwon Dec 2000 A
6185051 Chen et al. Feb 2001 B1
6186384 Sawada Feb 2001 B1
6191880 Schuster Feb 2001 B1
6210401 Lai Apr 2001 B1
6256328 Delfyett et al. Jul 2001 B1
6259058 Hoekstra Jul 2001 B1
6259151 Morrison Jul 2001 B1
6259512 Mizouchi Jul 2001 B1
6272156 Reed et al. Aug 2001 B1
6301932 Allen et al. Oct 2001 B1
6308055 Welland et al. Oct 2001 B1
6322958 Hayashi Nov 2001 B1
6339208 Rockstroh et al. Jan 2002 B1
6373565 Kafka et al. Apr 2002 B1
6381391 Islam et al. Apr 2002 B1
6396856 Sucha et al. May 2002 B1
6407360 Choo et al. Jun 2002 B1
6438996 Cuvelier Aug 2002 B1
6445491 Sucha et al. Sep 2002 B2
6449301 Wu et al. Sep 2002 B1
6461223 Bando Oct 2002 B1
6484052 Visuri et al. Nov 2002 B1
6489589 Alexander Dec 2002 B1
6501576 Seacombe Dec 2002 B1
6501578 Bernstein et al. Dec 2002 B1
6520057 Steadman Feb 2003 B1
6552301 Herman et al. Apr 2003 B2
6573026 Aitken et al. Jun 2003 B1
6592703 Habeck et al. Jul 2003 B1
6611647 Berkey et al. Aug 2003 B2
6635849 Okawa et al. Oct 2003 B1
6635850 Amako et al. Oct 2003 B2
6720519 Liu et al. Apr 2004 B2
6729151 Thompson May 2004 B1
6729161 Miura et al. May 2004 B1
6737345 Lin et al. May 2004 B1
6744009 Xuan et al. Jun 2004 B1
6787732 Xuan et al. Sep 2004 B1
6791935 Hatano et al. Sep 2004 B2
6800237 Yamamoto et al. Oct 2004 B1
6800831 Hoetzel Oct 2004 B1
6856379 Schuster Feb 2005 B2
6885502 Schuster Apr 2005 B2
6904218 Sun et al. Jun 2005 B2
6958094 Ohmi et al. Oct 2005 B2
6992026 Fukuyo et al. Jan 2006 B2
7009138 Amako et al. Mar 2006 B2
7061583 Mulkens et al. Jun 2006 B2
7102118 Acker et al. Sep 2006 B2
7187833 Mishra Mar 2007 B2
7196841 Melzer et al. Mar 2007 B2
7259354 Pailthorp et al. Aug 2007 B2
7353829 Wachter et al. Apr 2008 B1
7402773 Nomaru Jul 2008 B2
7408616 Gruner et al. Aug 2008 B2
7408622 Fiolka et al. Aug 2008 B2
7511886 Schultz et al. Mar 2009 B2
7535634 Savchenkov et al. May 2009 B1
7555187 Bickham et al. Jun 2009 B2
7565820 Foster et al. Jul 2009 B2
7633033 Thomas et al. Dec 2009 B2
7642483 You et al. Jan 2010 B2
7649153 Haight et al. Jan 2010 B2
7726532 Gonoe Jun 2010 B2
7794904 Brueck Sep 2010 B2
7800734 Komatsuda Sep 2010 B2
7832675 Bumgarner et al. Nov 2010 B2
7901967 Komura et al. Mar 2011 B2
7920337 Perchak Apr 2011 B2
7978408 Sawabe et al. Jul 2011 B2
8035803 Fiolka Oct 2011 B2
8035882 Fanton et al. Oct 2011 B2
8035901 Abramov et al. Oct 2011 B2
8041127 Whitelaw Oct 2011 B2
8041172 Sillard et al. Oct 2011 B2
8068279 Schuster et al. Nov 2011 B2
8104385 Hayashi et al. Jan 2012 B2
8118971 Hori et al. Feb 2012 B2
8123515 Schleelein Feb 2012 B2
8132427 Brown et al. Mar 2012 B2
8144308 Muramatsu Mar 2012 B2
8158514 Krueger et al. Apr 2012 B2
8164818 Collins et al. Apr 2012 B2
8168514 Garner et al. May 2012 B2
8194170 Golub et al. Jun 2012 B2
8211259 Sato et al. Jul 2012 B2
8218929 Bickham et al. Jul 2012 B2
8237918 Totzeck et al. Aug 2012 B2
8245539 Lu et al. Aug 2012 B2
8245540 Abramov et al. Aug 2012 B2
8248600 Matousek et al. Aug 2012 B2
8259393 Fiolka et al. Sep 2012 B2
8269138 Garner et al. Sep 2012 B2
8279524 Fiolka et al. Oct 2012 B2
8283595 Fukuyo et al. Oct 2012 B2
8283695 Salcedo et al. Oct 2012 B2
8292141 Cox et al. Oct 2012 B2
8296066 Zhao et al. Oct 2012 B2
8327666 Harvey et al. Dec 2012 B2
8339578 Omura Dec 2012 B2
8341976 Dejneka et al. Jan 2013 B2
8347551 Van Der Drift Jan 2013 B2
8347651 Abramov et al. Jan 2013 B2
8358868 Iketani Jan 2013 B2
8358888 Ramachandran Jan 2013 B2
8379188 Mueller et al. Feb 2013 B2
8444905 Li et al. May 2013 B2
8444906 Lee et al. May 2013 B2
8448471 Kumatani et al. May 2013 B2
8475507 Dewey et al. Jul 2013 B2
8482717 Fiolka et al. Jul 2013 B2
8491983 Ono et al. Jul 2013 B2
8518280 Hsu et al. Aug 2013 B2
8549881 Brown et al. Oct 2013 B2
8584354 Cornejo et al. Nov 2013 B2
8584490 Garner et al. Nov 2013 B2
8592716 Abramov et al. Nov 2013 B2
8604380 Howerton et al. Dec 2013 B2
8607590 Glaesemann et al. Dec 2013 B2
8616024 Cornejo et al. Dec 2013 B2
8635857 Crosbie Jan 2014 B2
8635887 Black et al. Jan 2014 B2
8680489 Martinez et al. Mar 2014 B2
8685838 Fukuyo et al. Apr 2014 B2
8687932 Peckham et al. Apr 2014 B2
8697228 Carre et al. Apr 2014 B2
8720228 Li May 2014 B2
8724937 Barwicz et al. May 2014 B2
8826696 Brown et al. Sep 2014 B2
8842358 Bareman et al. Sep 2014 B2
8847112 Panarello et al. Sep 2014 B2
8852698 Fukumitsu Oct 2014 B2
8887529 Lu et al. Nov 2014 B2
8916798 Pl?s Dec 2014 B2
8943855 Gomez et al. Feb 2015 B2
8951889 Ryu et al. Feb 2015 B2
8971053 Kariya et al. Mar 2015 B2
9028613 Kim et al. May 2015 B2
9052605 Van et al. Jun 2015 B2
9086509 Knutson Jul 2015 B2
9138913 Arai et al. Sep 2015 B2
9170500 Van et al. Oct 2015 B2
9227868 Matsumoto et al. Jan 2016 B2
9290407 Barefoot et al. Mar 2016 B2
9296066 Hosseini et al. Mar 2016 B2
9324791 Tamemoto Apr 2016 B2
9327381 Lee et al. May 2016 B2
9341912 Shrivastava et al. May 2016 B2
9346706 Bazemore et al. May 2016 B2
9446590 Chen et al. Sep 2016 B2
9477037 Bickham et al. Oct 2016 B1
9481598 Bergh et al. Nov 2016 B2
9499343 Cornelissen et al. Nov 2016 B2
9517929 Hosseini Dec 2016 B2
9517963 Marjanovic 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 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 et al. Sep 2001 A1
20010027842 Curcio et al. Oct 2001 A1
20020046997 Nam et al. Apr 2002 A1
20020082466 Han Jun 2002 A1
20020097486 Yamaguchi et al. 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 et al. Jan 2003 A1
20030007772 Borrelli et al. Jan 2003 A1
20030007773 Kondo et al. Jan 2003 A1
20030038225 Mulder et al. 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 et al. Jun 2004 A1
20040144231 Hanada Jul 2004 A1
20040218882 Bickham et al. Nov 2004 A1
20040221615 Postupack et al. Nov 2004 A1
20040228593 Sun et al. Nov 2004 A1
20050024743 Camy-Peyret Feb 2005 A1
20050098458 Gruetzmacher et al. May 2005 A1
20050098548 Kobayashi et al. May 2005 A1
20050115938 Sawaki et al. 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 et al. Oct 2005 A1
20050274702 Deshi Dec 2005 A1
20050277270 Yoshikawa et al. Dec 2005 A1
20060011593 Fukuyo et al. Jan 2006 A1
20060021385 Cimo et al. Feb 2006 A1
20060028706 Totzeck et al. Feb 2006 A1
20060028728 Li Feb 2006 A1
20060050261 Brotsack Mar 2006 A1
20060109874 Shiozaki et al. May 2006 A1
20060118529 Aoki et al. Jun 2006 A1
20060127679 Gulati et al. Jun 2006 A1
20060146384 Schultz et al. Jul 2006 A1
20060151450 You et al. Jul 2006 A1
20060170617 Latypov et al. Aug 2006 A1
20060213883 Eberhardt et al. Sep 2006 A1
20060227440 Gluckstad Oct 2006 A1
20060266744 Nomaru Nov 2006 A1
20060289410 Morita et al. Dec 2006 A1
20060291835 Nozaki et al. Dec 2006 A1
20070021548 Hattori et al. Jan 2007 A1
20070030471 Troost et al. Feb 2007 A1
20070044606 Kang et al. Mar 2007 A1
20070045253 Jordens et al. Mar 2007 A1
20070051706 Bovatsek et al. Mar 2007 A1
20070068648 Hu et al. Mar 2007 A1
20070090180 Griffis et al. Apr 2007 A1
20070091977 Sohn et al. Apr 2007 A1
20070111119 Hu et al. May 2007 A1
20070111390 Komura et al. May 2007 A1
20070111480 Maruyama et al. May 2007 A1
20070119831 Kandt May 2007 A1
20070132977 Komatsuda Jun 2007 A1
20070138151 Tanaka et al. Jun 2007 A1
20070177116 Amako Aug 2007 A1
20070202619 Tamura et al. Aug 2007 A1
20070209029 Ivonin et al. Sep 2007 A1
20070228616 Bang Oct 2007 A1
20070298529 Maeda et al. Dec 2007 A1
20080000884 Sugiura et al. Jan 2008 A1
20080050584 Noguchi et al. Feb 2008 A1
20080079940 Sezerman et al. Apr 2008 A1
20080087629 Shimomura et al. Apr 2008 A1
20080099444 Misawa et al. May 2008 A1
20080158529 Hansen Jul 2008 A1
20080165925 Singer et al. Jul 2008 A1
20080190981 Okajima et al. Aug 2008 A1
20080239268 Mulder et al. Oct 2008 A1
20080309902 Rosenbluth Dec 2008 A1
20080314879 Bruland et al. Dec 2008 A1
20080318028 Winstanley et al. Dec 2008 A1
20090013724 Koyo et al. Jan 2009 A1
20090032510 Ando et al. Feb 2009 A1
20090033902 Mulder et al. Feb 2009 A1
20090050661 Na et al. Feb 2009 A1
20090060437 Fini et al. Mar 2009 A1
20090091731 Ossmann et al. Apr 2009 A1
20090157341 Cheung Jun 2009 A1
20090170286 Tsukamoto et al. Jul 2009 A1
20090176034 Ruuttu et al. 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 et al. Oct 2009 A1
20090250446 Sakamoto Oct 2009 A1
20090294419 Abramov et al. Dec 2009 A1
20090294422 Lubatschowski et al. Dec 2009 A1
20090323160 Egerton et al. Dec 2009 A1
20090323162 Fanton et al. Dec 2009 A1
20090324899 Feinstein et al. Dec 2009 A1
20090324903 Rumsby Dec 2009 A1
20100020304 Soer et al. Jan 2010 A1
20100024865 Shah et al. Feb 2010 A1
20100025387 Arai et al. Feb 2010 A1
20100027951 Bookbinder et al. Feb 2010 A1
20100029460 Shojiya et al. Feb 2010 A1
20100032087 Takahashi et al. Feb 2010 A1
20100038349 Ke et al. Feb 2010 A1
20100046761 Henn et al. Feb 2010 A1
20100086741 Bovatsek et al. Apr 2010 A1
20100089631 Sakaguchi et al. Apr 2010 A1
20100089682 Martini et al. Apr 2010 A1
20100089882 Tamura Apr 2010 A1
20100102042 Garner et al. Apr 2010 A1
20100129603 Blick et al. May 2010 A1
20100145620 Georgi et al. Jun 2010 A1
20100147813 Lei et al. Jun 2010 A1
20100197116 Shah Aug 2010 A1
20100206008 Harvey et al. Aug 2010 A1
20100252538 Zeygerman Oct 2010 A1
20100252540 Lei et al. Oct 2010 A1
20100252959 Lei et al. Oct 2010 A1
20100276505 Smith Nov 2010 A1
20100279067 Sabia et al. Nov 2010 A1
20100287991 Brown et al. Nov 2010 A1
20100291353 Dejneka et al. Nov 2010 A1
20100320179 Morita et al. Dec 2010 A1
20100326138 Kumatani et al. 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 et al. Mar 2011 A1
20110049765 Li et al. 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
20110127697 Milne Jun 2011 A1
20110132581 Moss Jun 2011 A1
20110132881 Liu Jun 2011 A1
20110136303 Lee Jun 2011 A1
20110139760 Shah et al. Jun 2011 A1
20110143470 Lee Jun 2011 A1
20110177325 Tomamoto et al. Jul 2011 A1
20110183116 Hung et al. Jul 2011 A1
20110191024 DeLuca Aug 2011 A1
20110210105 Romashko et al. Sep 2011 A1
20110238308 Miller et al. Sep 2011 A1
20110240476 Wang et al. Oct 2011 A1
20110240611 Sandstr?m Oct 2011 A1
20110240617 Cheon et al. Oct 2011 A1
20110277507 Lu et al. Nov 2011 A1
20110300691 Sakamoto et al. Dec 2011 A1
20110318555 Bookbinder et al. Dec 2011 A1
20120017642 Teranishi et al. Jan 2012 A1
20120026573 Collins et al. Feb 2012 A1
20120047951 Dannoux et al. Mar 2012 A1
20120047956 Li Mar 2012 A1
20120047957 Dannoux et al. Mar 2012 A1
20120048604 Cornejo et al. Mar 2012 A1
20120061440 Roell Mar 2012 A1
20120064306 Kang et al. Mar 2012 A1
20120067858 Kangastupa et al. Mar 2012 A1
20120103018 Lu et al. 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 et al. May 2012 A1
20120135195 Glaesemann et al. May 2012 A1
20120135607 Shimoi et al. May 2012 A1
20120135608 Shimoi et al. May 2012 A1
20120145331 Gomez et al. Jun 2012 A1
20120147449 Bhatnagar et al. Jun 2012 A1
20120196071 Cornejo et al. Aug 2012 A1
20120196454 Shah et al. Aug 2012 A1
20120205356 Christoph 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 et al. Sep 2012 A1
20120234049 Bolton Sep 2012 A1
20120234807 Sercel et al. Sep 2012 A1
20120237731 Boegli et al. Sep 2012 A1
20120255935 Kakui et al. Oct 2012 A1
20120262689 Van et al. Oct 2012 A1
20120293784 Xalter et al. Nov 2012 A1
20120297568 Spezzani Nov 2012 A1
20120299219 Shimoi et al. Nov 2012 A1
20120302139 Darcangelo et al. Nov 2012 A1
20120320458 Knutson Dec 2012 A1
20120324950 Dale et al. Dec 2012 A1
20130019637 Sol et al. Jan 2013 A1
20130031879 Yoshikane et al. Feb 2013 A1
20130034688 Koike et al. Feb 2013 A1
20130044371 Rupp et al. Feb 2013 A1
20130047671 Kohli Feb 2013 A1
20130056450 Lissotschenko et al. Mar 2013 A1
20130061636 Imai et al. Mar 2013 A1
20130068736 Mielke et al. Mar 2013 A1
20130071079 Peckham et al. Mar 2013 A1
20130071080 Peckham et al. Mar 2013 A1
20130071081 Peckham et al. Mar 2013 A1
20130075480 Yokogi et al. Mar 2013 A1
20130078891 Lee et al. Mar 2013 A1
20130091897 Fujii et al. Apr 2013 A1
20130122264 Fujii et al. May 2013 A1
20130126573 Hosseini et al. May 2013 A1
20130126751 Mizoguchi et al. May 2013 A1
20130129947 Harvey et al. May 2013 A1
20130133367 Abramov et al. May 2013 A1
20130136408 Bookbinder et al. May 2013 A1
20130139708 Hotta Jun 2013 A1
20130143416 Norval Jun 2013 A1
20130149434 Oh et al. Jun 2013 A1
20130149494 Koike et al. Jun 2013 A1
20130167590 Teranishi et al. Jul 2013 A1
20130171425 Wang et al. Jul 2013 A1
20130174607 Wootton et al. Jul 2013 A1
20130174610 Teranishi et al. 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 et al. Aug 2013 A1
20130209731 Nattermann et al. Aug 2013 A1
20130210245 Jackl Aug 2013 A1
20130216573 Trusheim et al. Aug 2013 A1
20130220982 Thomas et al. Aug 2013 A1
20130221053 Zhang Aug 2013 A1
20130222877 Greer et al. Aug 2013 A1
20130224439 Zhang et al. Aug 2013 A1
20130228918 Chen et al. Sep 2013 A1
20130247615 Boek et al. Sep 2013 A1
20130248504 Kusuda Sep 2013 A1
20130266757 Giron et al. Oct 2013 A1
20130270240 Kondo Oct 2013 A1
20130280495 Matsumoto Oct 2013 A1
20130288010 Akarapu et al. Oct 2013 A1
20130291598 Saito et al. Nov 2013 A1
20130312460 Kunishi et al. Nov 2013 A1
20130323469 Abramov et al. Dec 2013 A1
20130334185 Nomaru Dec 2013 A1
20130340480 Nattermann et al. Dec 2013 A1
20130344684 Bowden Dec 2013 A1
20140023087 Czompo Jan 2014 A1
20140027951 Srinivas et al. Jan 2014 A1
20140034730 Lee Feb 2014 A1
20140036338 Bareman et al. Feb 2014 A1
20140042202 Lee Feb 2014 A1
20140047957 Wu Feb 2014 A1
20140083986 Zhang et al. Mar 2014 A1
20140102146 Saito et al. Apr 2014 A1
20140110040 Cok Apr 2014 A1
20140113797 Yamada et al. Apr 2014 A1
20140133119 Kariya et al. May 2014 A1
20140141192 Fernando et al. May 2014 A1
20140141217 Gulati et al. May 2014 A1
20140147623 Shorey et al. May 2014 A1
20140147624 Streltsov et al. May 2014 A1
20140165652 Saito Jun 2014 A1
20140174131 Saito et al. Jun 2014 A1
20140182125 Rozbicki et al. Jul 2014 A1
20140199519 Schillinger et al. Jul 2014 A1
20140216108 Wiegel et al. 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 et al. Oct 2014 A1
20140333929 Sung et al. 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 et al. Dec 2014 A1
20150014891 Amatucci et al. Jan 2015 A1
20150034612 Hosseini et al. 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 et al. Mar 2015 A1
20150075222 Mader Mar 2015 A1
20150110442 Zimmel et al. 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 et al. 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 et al. Jun 2015 A1
20150166396 Marjanovic et al. 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 et al. 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 Patterson et al. Dec 2015 A1
20150362818 Greer Dec 2015 A1
20150367442 Bovatsek et al. Dec 2015 A1
20160008927 Grundmueller et al. Jan 2016 A1
20160009066 Nieber Jan 2016 A1
20160009585 Bookbinder et al. Jan 2016 A1
20160016257 Hosseini Jan 2016 A1
20160023922 Addiego et al. Jan 2016 A1
20160031737 Hoppe et al. Feb 2016 A1
20160031745 Ortner et al. Feb 2016 A1
20160039044 Kawaguchi Feb 2016 A1
20160059359 Krueger et al. Mar 2016 A1
20160060156 Krueger et al. 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
20160168396 Letocart et al. Jun 2016 A1
20160279895 Marjanovic et al. Sep 2016 A1
20160280580 Bohme Sep 2016 A1
20160282521 Uchiyama et al. Sep 2016 A1
20160290791 Buono et al. 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 Dumenil 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 (342)
Number Date Country
1259924 Jul 2000 CN
2388062 Jul 2000 CN
1283409 Feb 2001 CN
1473087 Feb 2004 CN
1517313 Aug 2004 CN
1573364 Feb 2005 CN
1619778 May 2005 CN
1735568 Feb 2006 CN
1890074 Jan 2007 CN
1920632 Feb 2007 CN
1930097 Mar 2007 CN
101031383 Sep 2007 CN
101048255 Oct 2007 CN
101386466 Mar 2009 CN
101502914 Aug 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
102649199 Aug 2012 CN
102672355 Sep 2012 CN
102674709 Sep 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
103143841 Jun 2013 CN
103159401 Jun 2013 CN
203021443 Jun 2013 CN
103237771 Aug 2013 CN
103273195 Sep 2013 CN
103316990 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
104344202 Feb 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
1020448 Dec 1957 DE
2231330 Jan 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 Jun 1988 EP
609978 Aug 1994 EP
0656241 Jun 1995 EP
0938946 Sep 1999 EP
0949541 Oct 1999 EP
1043110 Oct 2000 EP
1159104 Dec 2001 EP
1306196 May 2003 EP
1609559 Dec 2005 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 Dec 2011 GB
53-018756 Feb 1978 JP
61-074794 Apr 1986 JP
61027212 Jun 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
09-109243 Apr 1997 JP
9106243 Apr 1997 JP
11-079770 Mar 1999 JP
11-197498 Jul 1999 JP
11269683 Oct 1999 JP
11-330597 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
2002-205181 Jul 2002 JP
2002-210730 Jul 2002 JP
2002228818 Aug 2002 JP
2003-025085 Jan 2003 JP
2003062756 Mar 2003 JP
2003114400 Apr 2003 JP
2003154517 May 2003 JP
2003-181668 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
2005135964 May 2005 JP
2005-144487 Jun 2005 JP
2005-179154 Jul 2005 JP
2005-219960 Aug 2005 JP
2005205440 Aug 2005 JP
2005288503 Oct 2005 JP
3775250 May 2006 JP
3775410 May 2006 JP
2006130691 May 2006 JP
2006-150385 Jun 2006 JP
2006-182009 Jul 2006 JP
3823108 Sep 2006 JP
2006248885 Sep 2006 JP
2006-327711 Dec 2006 JP
2007021548 Feb 2007 JP
2007-196277 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
2009-084089 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
04592855 Dec 2010 JP
2011-011212 Jan 2011 JP
2011-037707 Feb 2011 JP
2011049398 Mar 2011 JP
2011-512259 Apr 2011 JP
04672689 Apr 2011 JP
2011-517299 Jun 2011 JP
2011-517622 Jun 2011 JP
2011-138083 Jul 2011 JP
2011-520748 Jul 2011 JP
2011-147943 Aug 2011 JP
2011-240291 Dec 2011 JP
04880820 Feb 2012 JP
2012024782 Feb 2012 JP
2012031018 Feb 2012 JP
2012-517957 Aug 2012 JP
2012159749 Aug 2012 JP
2012187618 Oct 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
2013-136075 Jul 2013 JP
2013-144613 Jul 2013 JP
2013-528492 Jul 2013 JP
2013-150990 Aug 2013 JP
05274085 Aug 2013 JP
2013168445 Aug 2013 JP
2013-536081 Sep 2013 JP
05300544 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
2014-104484 Jun 2014 JP
2014-117707 Jun 2014 JP
2014-156289 Aug 2014 JP
2015-030040 Feb 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
2016-513024 May 2016 JP
2016-515085 May 2016 JP
6061193 Jan 2017 JP
10-2002-0031573 May 2002 KR
2009057161 Jun 2009 KR
10-2009-0107417 Oct 2009 KR
2010-0120297 Nov 2010 KR
1020621 Mar 2011 KR
10-2011-0120862 Nov 2011 KR
2011-0121637 Nov 2011 KR
10-2012-0000073 Jan 2012 KR
2012015366 Feb 2012 KR
10-1120471 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
1344368 Dec 2013 KR
2014022980 Feb 2014 KR
2014022981 Feb 2014 KR
1020140064220 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
201139025 Nov 2011 TW
201226345 Jul 2012 TW
201311592 Mar 2013 TW
201331136 Aug 2013 TW
201339111 Oct 2013 TW
9821154 May 1998 WO
1999029243 Jun 1999 WO
1999063900 Dec 1999 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
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
2014161534 Oct 2014 WO
2014161535 Oct 2014 WO
2015077113 May 2015 WO
2015094898 Jun 2015 WO
2015095088 Jun 2015 WO
2015095090 Jun 2015 WO
2015095146 Jun 2015 WO
2015095151 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
2016154284 Sep 2016 WO
2017009149 Jan 2017 WO
2017091529 Jun 2017 WO
2017093393 Jun 2017 WO
Non-Patent Literature Citations (119)
Entry
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.
“Aviation Manufacturing Technology”; Beijing Aviation Manufacturing Engineering Research Institute Aviation Industry Press; (2013) p. 147.
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”.
Betriebsanleitung; TruMicro 5000; Aug. 2011; pp. 1-4.
Case Design Guidelines for Apple Devices; Sep. 13, 2013; pp. 1-58; Apple Inc.
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 20. Nov. 2019 GMvp5 p. 1.
Corning Eagle AMLCD Glass Substrates Material Information; Apr. 2005; pp. MIE 201-1-MIE 201-3; Corning Incorporated.
D5 Claims GMvP2 p. 1.
D6 Amended claim 1 EP947: Anspruch 1—geandert am 21. Nov. 2018 GMvp3 p. 1.
EagleEtch; TheAnti-glare Glass for Technical Display Applications; Glass and Polymer Technologies; pp. 1-8; EuropTec USA Inc.
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.
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.
GT ASF Grown Sapphire Cover and Touch Screen Material; wvvw.gtat.com, 2012; pp. 1-2; GTAT Corporation.
High aspect ratio machining . . . Anlage E8-1.pdf.
International Search Report and Written Opinion of the International Searching Authority; PCT/EP14/50610; dated Apr. 15, 2014; 19 Pages; (9 Pages of English Translation and 10 Pages of Original Document); European Patent Office.
International Search Report and Written Opinion of the International Searching Authority; PCT/IB2014/000035; dated Apr. 15, 2014; 10 Pages; European Patent Office.
Jonas Weiss, et al., “Optical Interconnects for Disaggregated Resources in Future Datacenters”, ECOC 2014, Cannes-France, 3 pgs.
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:Sep. 1999 Apr. 1, 2005 GMvP23 pages.
Norm: ISO/TR 11146-3 , Technical Report First edition GMvP Norm-TR 1 Pages.
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.
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 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.
Ra & RMS: Calculating Surface Roughness; Harrison Eelectropolishing; 2012.
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).
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,. 978-1-4799-2407-3, 2014 IEEE, pp. 179-185.
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/20160601OOOOOO/http://www.unichains.com/.
Perry et al., “Ultrashort-pulse laser machining”; UCRL-JC-132159 Rev 1., Jan. 22, 1999, pp. 1-24.
Pharos High-power femtosecond laser system product brochure; Light Conversion, Vilnius, LT; Apr. 18, 2011, pp. 1-2.
Polynkin et al., “Extended filamentation with temporally chirped femtosecond Bessel-Gauss beams in air”; Optics Express, vol. 17, No. 2, Jan. 19, 2009, OSA, pp. 575-584.
Thiele, “Relation between catalytic activity and size of particle Industrial and Egineering Chemistry, vol. 31 no. 7, pp. 916-920”.
Romero et al. “Theory of optimal beam splitting by phase gratings. II. Square and hexagonal gratings” J. Opt. Soc. Am. A/vol. 24 No. 8 (2007) pp. 2296-2312.
Salleo A et al., Machining of transparent materials using IR and UV nanosecond laser pulses, Appl. Physics A 71, 601-608, 2000.
Serafetinides et al., “Polymer ablation by ultra-short pulsed lasers” Proceedings of SPIE vol. 3885 (2000) http://proceedings.spiedigitallibrary.org/.
Serafetinides et al., “Ultra-short pulsed laser ablation of polymers”; Applied Surface Science 180 (2001) 42-56.
Shah et al. “Micromachining with a high repetition rate femtosecond fiber laser”, Journal of Laser Micro/Nanoengineering vol. 3 No. 3 (2008) pp. 157-162.
Shealy et al. “Geometric optics-based design of laser beam shapers” ,Opt. Eng. 42(11), 3123-3138 (2003). doi:10.1117/1.1617311.
Stoian et al. “Spatial and temporal laser pulse design for material processing on ultrafast scales” Applied Physics A (2014) 114, p. 119-127.
Kruger et al; “Structuring of dielectric and metallic materials with ultrashort laser pulses between 20 fs and 3 ps”; SPIE vol. 2991, 0277-786X/97, pp. 40-47.
Sundaram et al., “Inducing and probing non-thermal transitions in semiconductors using femtosecond laser pulses”; Nature Miracles, vol. 1, Dec. 2002, Nature Publishing Group (2002), pp. 217-224.
Toytman et al. “Optical breakdown in transparent media with adjustable axial length and location”, Optics Express vol. 18 No. 24, 24688-24698 (2010).
TruMicro 5000 Product Manual, Trumpf Laser GmbH + Co. KG, pp. 1-4, Aug. 2011.
Bhuyan et al.; “Ultrafast Bessel beams for high aspect ratio taper free micromachining of glass Proc. Of SPIE vol. 7728 77281V-1”.
Vanagas et al., “Glass cutting by femtosecond pulsed irradiation”; J. Micro/Nanolith. MEMS MOEMS. 3(2), 358-363 (Apr. 1, 2004); doi: 10.1117/1.1668274.
Varel et al., “Micromachining of quartz with ultrashort laser pulses”; Applied Physics A 65, 367-373, Springer-Verlag(1997).
Velpula et al.. “Ultrafast imaging of free carriers: controlled excitation with chirped ultrafast laser Bessel beams”, Proc. Of SPIE vol. 8967 896711-1 (2014.
Wang et al., “Investigation on CO2 laser irradiation inducing glass strip peeling for microchannel formation”, Biomicrofluidics 6, 012820 (2012.
Wu et al. “Optimal orientation of the cutting head for enhancing smoothness movement in three-dimensional laser cutting” 2013) Zhongguo Jiguang/Chinese Journal of Lasers, 40 (1), art. No. 0103005.
Xu et al. “Optimization of 3D laser cutting head orientation based on the minimum energy consumption” 2014) International Journal of Advanced Manufacturing Technology, 74 (9-12), pp. 1283-1291.
Yan et al. “Fiber structure to convert a Gaussian beam to higher-order optical orbital angular momentum modes” Optics Letters vol. 37 No. 16 (2012) pp. 3294-3296.
Yoshino et al., “Micromachining with a high repetition rate femtosecond fiber laser”; JLMN-Journal of Laser Micro/Nanoengineering vol. 3, No. 3 (2008), pp. 157-162.
Zeng et al. “Characteristic analysis of a refractive axicon system for optical trepanning”; Optical Engineering 45(9), 094302 (Sep. 2006), pp. 094302-1-094302-10.
Zhang et al., “Design of diffractive-phase axicon illuminated by a Gaussian-profile beam”; Acta Physica Sinica (overseas edition), vol. 5, No. 5 (May 1996) Chin. Phys. Soc., 1004-423X/96/05050354-11, pp. 354-364.
Ahmed et al. “Display glass cutting by femtosecond laser induced single shot periodic void array” Applied Physics A: Materials Science and Proccessing vol. 93 No. 1 (2008) pp. 189-192.
Arimoto et al., “Imaging properties of axicon in a scanning optical system”; Applied Optics, Nov. 1, 1992, vol. 31, No. 31, pp. 6653-6657.
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).
http://www.gtat.com/Collateral/Documents/English-US/Sapphire/12-21-12_GT_TouchScreen_V3_web.pdf.
Product Data Sheet for Corning Eagle XG Slim Glass, Issued Aug. 2013; 2 Pages.
Louis A. Romero* and Fred M. Dickey, “Theory of optimal beam splitting by phase gratings. I. One-dimensional gratings” J. Opt. Soc. Am., A 24, 2280, (2007).
“What is the difference between Ra and RMS?”; Harrison Electropolishing LP; (http://www.harrisonep.com/electropolishingra.html), Accessed Aug. 8, 2016.
Abakians et al. “Evaporative Cutting of a Semitransparent Body With a Moving CW Laser”, J. Heat Transfer 110 (4a), 924-930 (Nov. 1, 1988) (7 pages) doi: 10.1115/1.3250594.
Abramov et al., “Laser separation of chemically strengthened glass”; Physics Procedia 5 (2010) 285-290, Elsevier.
Bagchi et al. “Fast ion beams from intense, femtosecond laser irradiated nanostructured surfaces” Applied Physics B 88 (2007) p. 167-173.
Bhuyan et al. “Laser micro- and nanostructuring using femtosecond Bessel beams”, Eur. Phys. J. Special Topics 199 (2011) p. 101-110.
Bhuyan et al. “Single shot high aspect ratio bulk nanostructuring of fused silica using chirp-controlled ultrafast laser Bessel beams” Applied Physics Letters 104 (2014) 021107.
Bhuyan et al., “Femtosecond non-diffracting Bessel beams and controlled nanoscale ablation” by IEEE (2011).
Bhuyan et al., “High aspect ratio nanochannel machining using single shot femtosecond Bessel beams”; Applied Physics Letters 97, 081102 (2010); doi: 10.1063/1.3479419.
Bhuyan et al., “High aspect ratio taper-free microchannel fabrication using femtosecond Bessel beams”; Optics Express (2010) vol. 18, No. 2, pp. 566-574.
Chiao et al. 9. “Self-trapping of optical beams,” Phys. Rev. Lett, vol. 13, No. 15, p. 479 (1964).
Corning Inc., “Corning® 1737 AM LCD Glass Substrates Material Information”, issued Aug. 2002.
Corning Inc., “Corning® Eagle2000 TM AMLCD Glass Substrates Material Information”, issued Apr. 2005.
Couairon et al. “Femtosecond filamentation in transparent media” Physics Reports 441 (2007) pp. 47-189.
Courvoisier et al. “Applications of femtosecond Bessel beams to laser ablation” Applied Physics A (2013) 112, p. 29-34.
Courvoisier et al. “Surface nanoprocessing with non-diffracting femtosecond Bessel beams” Optics Letters vol. 34 No. 20, (2009) p. 3163-3165.
Cubeddu et al., “A compact time-resolved reflectance system for dual-wavelength multichannel assessment of tissue absorption and scattering”; Part of the SPIE Conference on Optical Tomography and Spectroscopy of Tissue III, San Jose, CA (Jan. 1999), SPIE vol. 3597, 0277-786X/99, pp. 450-455.
Cubeddu et al., “Compact tissue oximeter based on dual-wavelength multichannel time-resolved reflectance” Applied Optics, vol. 38, No. 16, Jun. 1, 1999, pp. 3670-3680.
Ding et al., “High-resolution optical coherence tomography over a large depth range with an axicon lens”; Optic Letters, vol. 27, No. 4, pp. 243-245, Feb. 15, 2002, Optical Society of America.
Dong et al. “On-axis irradiance distribution of axicons illuminated by spherical wave”, Optics & Laser Technology 39 (2007) 12581261.
Duocastella et al. “Bessel and annular beams for material processing”, Laser Photonics Rev. 6, 607-621, 2012.
EagleEtch Product Brochure, EuropeTec USA Inc., pp. 1-8, Aug. 1, 2014.
Eaton et al. “Heat accumulation effects in femtosecond laser written waveguides with variable repetition rates”, Opt. Exp. 5280, vol. 14, No. 23, Jun. 2006.
Durnin “Exact solutions for nondiffracting beams I. The scaler theory J. Opt. Soc. Am. A. 4(4) pp. 651-654”.
Gattass et al. “Micromachining of bulk glass with bursts of femtosecond laser pulses at variable repetition rates” Opt. Exp. 5280, vol. 14, No. 23, Jun. 2006.
Girkin et al., “Macroscopic multiphoton biomedical imaging using semiconductor saturable Bragg reflector modelocked Lasers”; Part of the SPIE Conference on Commercial and Biomedical Applications of Ultrafast Lasers, San Jose, CA (Jan. 1999), SPIE vol. 3616, 0277-786X/99, pp. 92-98.
Glezer et al., “Ultrafast-laser driven micro-explosions in transparent materials”; Applied Physics Letters, vol. 71 (1997), pp. 882-884.
Golub, I., “Fresnel axicon”; Optic Letters, vol. 31, No. 12, Jun. 15, 2006, Optical Society of America, pp. 1890-1892.
Gori et al. “Analytical derivation of the optimum triplicator” Optics Communications 157 (1998) pp. 13-16.
Herman et al., “Laser micromachining of‘transparent’ fused silica with 1-ps pulses and pulse trains”; Part of the SPIE Conference on Commercial and Biomedical Applications of Ultrafast Lasers, San Jose, CA (Jan. 1999), SPIE vol. 3616, 0277-786X/99, pp. 148-155.
Honda et al. “A Novel Polymer Film that Controls Light Transmission”, Progress in Pacific Polymer Science 3, 159-169 (1994).
Hu et al. “5-axis laser cutting interference detection and correction based on STL model” 2009) Zhongguo Jiguang/Chinese Journal of Lasers, 36 (12), pp. 3313-3317.
Huang et al., “Laser etching of glass substrates by 1064 nm laser irradiation”, Applied Physics, Oct. 2008, vol. 93, Issue 1, pp. 159-162.
Juodkazis S. et al. Laser induced microexplosion confined in the bulk of a sapphire crystal: evidence of multimegabar pressures., Phys. Rev. Lett. 96, 166101, 2006.
Karlsson et al. “The technology of chemical glass strengthening—a review” Glass Technol: Eur. J. Glass Sci. Technol. A (2010) 51 (2) pp. 41-54.
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.
Kosareva et al., “Formation of extended plasma channels in a condensed medium upon axicon focusing of a femtosecond laser pulse”; Quantum Electronics 35 (11) 1013-1014 (2005), Kvantovaya Elektronika and Turpion Ltd.; doi: 10.1070/QE2005v035n11ABEH013031.
Kruger et al., “Femtosecond-pulse visible laser processing of transparent materials”; Applied Surface Science 96-98 (1996) 430-438.
Kruger et al., “Laser micromachining of barium aluminium borosilicate glass with pluse durations between 20 fs and 3 ps”; Applied Surface Science 127-129 (1998) 892-898.
Lapczyna et al., “Ultra high repetition rate (133 MHz) laser ablation of aluminum with 1.2-ps pulses”; Applied Physics A 69 [Suppl.], S883-S886, Springer-Verlag (1999); doi: 10.1007/s003399900300.
Levy et al. “Design, fabrication, and characterization of circular Dammann gratings based on grayscale lithography,” Opt. Lett vol. 35, No. 6, p. 880-882 (2010).
Liu X et al. “laser ablation and micromachining with ultrashort laser pulses”, IEEE J. Quantum Electronics, 22, 1706-1716, 1997.
Maeda et al. “Optical performance of angle-dependent light-control glass”, Proc. SPIE 1536, Optical Materials Technology for Energy Efficiency and Solar Energy Conversion X, 138 (Dec. 1, 1991).
Mbise et al. “Angular selective window coatings: theory and experiments” J. Phys. D: Appl. Phys. 30 2103 (1997.
McGloin et al. “Bessel beams: diffraction in a new light” Contemporary Physics, vol. 46 No. 1 (2005) pp. 15-28.
Merola et al. “Characterization of Bessel beams generated by polymeric microaxicons” Meas. Sci. Technol. 23 (2012) 10 pgs.
Mirkhalaf, M. et al., Overcoming the brittleness of glass through bio-inspiration and micro-achitecture, Nature Communications, 5:3166/ncomm4166(2014).
Perry et al., “Ultrashort-pulse laser machining of dielectric materials”; Journal of Applied Physics, vol. 85, No. 9, May 1, 1999, American Institute of Physics, pp. 6803-6810.
Perry et al., “Ultrashort-pulse laser machining”; UCRL-ID-132159, Sep. 1998, pp. 1-38.
Related Publications (1)
Number Date Country
20190352215 A1 Nov 2019 US
Provisional Applications (1)
Number Date Country
61752489 Jan 2013 US
Continuations (1)
Number Date Country
Parent 14761275 US
Child 16527986 US