This disclosure is related to the following commonly-assigned U.S. Patent Applications, each of which is hereby incorporated herein by reference:
A spectrometer is an analytical instrument in which an emission (e.g., particles or radiation) is dispersed according to some property of the emission (e.g., mass or energy), and the amount of dispersion is then measured. Analysis of the dispersion measurement can reveal information regarding the emission, such as the identity of the individual particles of the emission.
One type of spectrometer is a mass spectrometer, which can be used to determine the chemical composition of substances and the structures of molecules. One type of mass spectrometer is a time-of-flight (TOF) mass spectrometer, which records the mass spectra of compounds or mixtures of compounds by measuring the time (e.g., in tens to hundreds of microseconds) for molecular and/or fragment ions of those compounds to traverse a drift region within a high vacuum environment. TOF mass spectrometers operate based on the principle that, when ions are accelerated with a fixed energy, the velocity of the ions depend exclusively on mass and charge. Thus, the time-of-flight of an ion drifting from point A to point B will differ depending on the mass of the ion. Using a TOF mass spectrometer, the mass of an ion can be calculated based upon its time of flight. This allows the molecule to be identified with precision.
TOF mass spectrometers are comprised of a source region, where neutral molecules are ionized, a drift region, followed by an ion reflector (also known as a reflectron) and a detector. The ion source provides a high vacuum environment in which ions are formed, and the ions are subsequently accelerated into a drift region (which may be field-free). The ions separate in time, depending only on their mass/charge ratio (the ion charge is often +1). Upon entering the opposing field created by the reflectron, the ions gradually slow down until they ultimately stop and reverse direction. Ion detection occurs after the ions are re-accelerated back out of the reflectron. In addition to enabling the calculation of the mass of the ions, ion packet peak widths are sharpened by their passage through the reflectron, resulting in an enhancement of the instrument's resolving power.
Reflectrons have been in use since the late 1960's and are typically constructed by configuring a series of individually manufactured metallic rings along ceramic rods using insulating spacers to separate each ring from the next. This technique is labor intensive, costly, and limits the flexibility of design due to the manufacture and handling of extremely thin rings (e.g., a few mils in thickness) of relatively large diameter (often 1″ or greater). An example of such a configuration is shown in U.S. Pat. No. 4,625,112 to Yoshida, which is hereby incorporated herein by reference.
The rings are often placed at potentials that develop uniform electric fields along the axis of the cylinder. However, to improve performance in a TOF mass spectrometer, reflectrons have also been constructed which develop non-uniform fields along the reflectron tube. The non-uniform fields are generated by utilizing a voltage divider network which varies the potential applied to each of the evenly-spaced rings. A detailed explanation of non-linear reflectron theory can be found in U.S. Pat. No. 5,464,985 to Cornish, et al., which is hereby incorporated in its entirety herein by reference.
Additional examples of reflectrons and TOF mass spectrometry theory can also be found in U.S. Pat. No. 6,013,913 to Hanson, U.S. Pat. No. 6,365,892 to Cotter, et al., and U.S. Pat. No. 6,607,414 to Cornish, et al., each of which is hereby incorporated herein by reference.
While the above-described TOF mass spectrometer design has proved quite satisfactory for large reflectors in which the rings are relatively large in diameter and equally spaced, new applications utilizing remote and/or mobile TOF mass spectrometers may require miniaturized components, rugged construction, and/or lightweight materials.
The present disclosure is best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact.
Referring to
The apparatus 100 includes a substrate 105, a pair of grid electrodes 110, and a plurality of ion reflection lenses 120. The ion reflection lenses 120 may be coupled to the substrate 105 by adhesive, bonding, soldering, brazing, mechanical clips and other fasteners, combinations thereof, and/or other means.
In an exemplary embodiment, the grid electrodes 110 and/or the ion reflection lenses 120 may be coupled to the substrate 105 by connector/socket pairs, such as those shown in U.S. patent application Ser. No. 10/778,460, entitled “MEMS MICROCONNECTORS AND NON-POWERED MICROASSEMBLY THEREWITH,” filed Feb. 13, 2004, . For example, each of the grid electrodes 110 and/or the ion reflection lenses 120 may include an integral connector (also referred to herein as a microconnector or microconnector portion) for engaging a corresponding socket on the substrate 105. The connectors may also be separate components bonded or otherwise coupled to the grid electrodes 110 and/or the ion reflection lenses 120. The substrate 105 may also include traces or other conductive members 107 electrically connected to corresponding sockets for providing current and/or biasing signals to the ones of the grid electrodes and/or the ion reflection lenses 120.
The grid electrodes 110 may comprise a body portion 111 and a plurality of conductive grid portions 112. For example, the body portion 111 may comprise silicon or other dielectric or semiconductive material, and the conductive grid portions 112 may comprise gold or other conductive materials deposited on the body portion 111 and/or within a plurality of recesses formed within the body portion 111. In an exemplary embodiment, the grid electrodes 110 may be formed from the same substrate as the substrate 105, then separated from the substrate 105, and subsequently positioned and coupled into the position shown in
The grid electrodes 110 may be oriented substantially parallel to one another on opposing sides of a central axis 108, such that conductive grid portions 112 of the grid electrodes 110 each face the central axis 108. The grid electrodes 110 may be substantially equidistant from the central axis 108.
Each lens 120 may be spaced in series in alignment with the central axis 108. For example, each lens 120 may comprise a central aperture 122 which may be bisected by a plane extending perpendicular from the substrate 105 through the central axis 108.
Referring to
The lens 120 may include a handle 320 configured to frictionally engage a manipulation probe, such as the probe shown in U.S. patent application Ser. No. 10/778,460, entitled “MEMS MICROCONNECTORS AND NON-POWERED MICROASSEMBLY THEREWITH,” filed Feb. 13, 2004. In an exemplary embodiment, the handle 320 is defined in the SCS layer as having two or more compliant legs 330 configured to deflect away from each other in response to insertion of the manipulation probe. Thus, the handle 320 may be a compliant handle. The legs 330 may be formed separated from each other by a distance about equal to or at least slightly less than the width of the manipulation probe tip or other portion configured to be grasped by the legs 330. In one embodiment, such separation between the legs 330 may range between about 25 μm and about 300 μm. Although not limited by the scope of the present disclosure, the legs 330 may have a length ranging between about 50 μm and about 500 μm.
As in the illustrated embodiment, the legs 330 (or perhaps one or more other portions of the handle 320) may each include narrower members 340 connected at one end to a body 345 of the lens element 120, and connected at a second end to wider members 350 configured to grasp the manipulation probe. The narrower members 340 may each have a width ranging between about 5 μm and about 30 μm, and the wider members 350 may each have a width ranging between about 10 μm and about 100 μm.
The lens 120 also includes a deflectable connection member 360 having at least one first end 365 coupled to the handle, possibly via the body 345, as in the illustrated embodiment. The connection member 360 also includes at least one second end 367 configured to deflect and thereby engage a receptacle in response to disengagement of a manipulation probe from the handle 320. The one or more second ends 367 may include a barb, hook, lip, extension, tab, and/or other means 368 (hereafter collectively referred to as a barb) for engaging, mating or otherwise interfacing with an edge, surface or barb of the receptacle. The one or more second ends 367 may also include a shoulder or other interface means 369 (hereafter collectively referred to as a shoulder) for engaging, mating or otherwise interfacing with an edge, surface or barb of the receptacle, in addition to or as an alternative to the barb 368.
The connection member 360 may include tapered surfaces 370 or other means for deflecting outward in response to translation of the manipulation probe away from a retained position within the handle 320. The connection member 360 may also include an aperture 362 permitting removal of the manipulation probe after the lens 120 is secured to the receptacle. The width of the aperture 362 may be about equal to or at least slightly greater than a manipulation probe or tip thereof. The lens 120 may also include one or more anchor arms 380 coupled or integral to the body 345 and extending to a bearing plane, shoulder or other type of interface 385 configured to rest against a receptacle as a manipulation probe is translated from the handle 320 towards the aperture 362.
Although not shown in the illustrated embodiment, the lens 120 may also include means for detecting when the lens 120 is fully engaged with a receptacle. For example, the interface means 369 may include conductive contacts and/or other means which may close a circuit across anchor pads of the receptacle. In one embodiment, the connection member 360 may be similarly or alternatively configured to close a circuit across the receptacle, thereby indicating engagement of the lens 120 and the receptacle.
As also described above, the lens element 120 includes a central aperture 122 configured to influence the path of an ion passing therethrough. In an exemplary embodiment, at least a portion of the central aperture 122 may be metallized. For example, in the illustrated example, a layer of gold or other conductive metal may surround the central aperture 122 and extend along the arms 380 for contacting conductive anchor pads of the substrate 105 or receptacles formed therein. Alternatively, the entire surface 123 of the lens 120, or a substantial portion thereof, may include a layer of conductive material. The metallized central aperture is configured to create an electronic field configured to modify direction of ion flight therethrough.
Referring to
The receptacle 400 includes one, two or more deflectable retainers 410. The retainers 410 each include one, two, or more legs 420. The legs 420 each include a first end 425 coupled to the substrate 105 and a second end 427 configured to translate across the substrate 105. The translation of the second ends 427 of the legs 420 across the substrate 105 may be in response to the travel of a portion of a microconnector portion of a lens element 120 (such as the second ends 367 of the lens 120 shown in
The receptacle 400 may also include one or more anchor pads 440 coupled or integral thereto. The anchor pads 440 may be configured to resist translation (e.g., provide a travel “stop”) of a microconnector portion of a lens 120 as a manipulation probe is translated therein towards the receptacle 400. For example, the anchor pads 440 may be configured to interface with the anchor arm interfaces 385 shown in
The receptacle 400 may also include an aperture 450 configured to receive a microconnector portion of a lens 120 during microassembly. For example, the aperture 450 may be sized to receive the ends 367 of the microconnector 300 shown in
Referring to
The receptacle 805 may also be substantially similar in construction, materials, geometry and/or operation relative to the receptacle 400 shown in
The retainer 830 (and/or another portion of the receptacle 805) also includes two fingers 845. Like the legs 840, the fingers 845 may be or include substantially elongated members, possibly being substantially greater in thickness than in width and possibly greater in length that in width or thickness, such that the fingers 845 have sufficient flexibility to permit deflection when contacted with a portion of the microconnector 810. As shown in
The fingers 845 are coupled to or otherwise affixed to a substrate at ends proximate the location where the legs 840 are coupled to the substrate, such that, like the legs 840, other ends 847 of the fingers 845 are free to translate across the substrate. The ends 847 may have tapered surfaces 846, such that insertion of a portion of the microconnector 810 therebetween causes the fingers 845 to deflect away from each other yet remain in contact with the inserted portion of the microconnector 810.
In other embodiments similar to the exemplary embodiment shown in
The fingers 845 may, in some embodiments, improve the robustness and/or alignment of the microassembly 800. For example, in embodiments in which the fingers 845 are not employed, the contact between the microconnector 810 and the receptacle 805 may be limited to point and/or line contact at only two locations. However, in some embodiments employing one or more of the fingers 845, the contact between the microconnector 810 and the receptacle 805 may include point and/or line contact at three or more locations, which may improve the robustness and/or alignment of the coupling between the microconnector 810 and the receptacle 805.
As described above, assembling the microconnector 810 to the receptacle 805 can include the deflection of ends of the microconnector 810 (or ends of legs or leg portions of the microconnector 810). Such deflection may be in and/or establish a first plane of motion, which may be substantially perpendicular to a second plane in which the legs 840 and/or the fingers 845 deflect. For example, if the receptacle 805 is formed on or from a substrate, the legs of the microconnector 810 may deflect in a first plane that is substantially perpendicular to the substrate, whereas the legs 840 and/or the fingers 845 of the receptacle 805 may deflect in a second plane that is substantially parallel to the substrate. After assembly, the legs 840 and/or the fingers 845 may contact at least three locations on the microconnector 810, and the fingers 845 may be configured such that one of these three or more contact locations is offset from the other contact locations relative to the first plane, the second plane, or both the first and second planes.
Referring to
As shown in
Referring to
Referring to
Referring to
In one embodiment, the substrate 510 may be sized such that the assembly substrate and all or a portion of the lenses 120 employed in a single microassembly may be defined in the device layer of a single substrate, wafer, chip, or die. In another embodiment, the assembly substrate and/or the lens components 120 may be fabricated from multiple substrates, including those of different compositions.
In a subsequent processing step, all or portions of the insulating layer 520 may be removed, such as by one or more wet or dry etching processes. Consequently, at least a portion of the device layer 530 may be “released” from the substrate 510. However, a portion of the device layer 530 may also be tethered to the substrate by a portion or “tether” of the device layer extending between released and non-released portions. Accordingly, the released portion of the device layer 530 may be maintained in a substantially known position to facilitate capture of a released portion of the device layer 530 during a subsequent assembly process.
Referring to
The apparatus 600 also includes an ion source 602 and an ion detector 604 each coupled to the substrate 601. The ion source 602 is or includes an electron impact ionization source, such as the EGA-1110 available from Kimball-Physics Inc., although other ion source means are also within the scope of the present disclosure. The ion detector 604 is or includes a microchannel plate electron multiplier, such as available from Burle Industries, although other ion detection means are also within the scope of the present disclosure.
In an exemplary method of operation, an ion emitter from the ion source 602 travels along one of the paths 606a-606c shown in
Accordingly, the times of flight of ions A-C between the ion source 602 and the ion detector 604 are indicative of the relative mass of the ions A-C. That is, because the time of flight for ion A to travel from the ion source 602 to the ion detector 604 through the lenses 120 is greater than the time of flight for ions B and C to travel from the ion source 602 to the ion detector 604 through the lenses 120, the mass X of ion A is known to be greater than the mass Y of ion B and the mass Z of ion C. Consequently, if an ion of known mass is caused to be driven from the ion source 602 to the ion detector 604 through the lenses 120, the time of flight for that ion can be used to calibrate the apparatus 600. Therefore, as additional ions of unknown mass are caused to be driven from the ion source 602 to the ion detector 604 through the lenses 120, their time of flight relative to the known ion's time of flight can be used to determine the relative or specific mass of the ions.
In the exemplary embodiment shown in
Accordingly, referring to
The apparatus 700 also includes four pairs of grid electrodes 110a-d each coupled to the substrate 701 by receptacles (such as the receptacles 400 described above) and/or other means, although such receptacles are not shown in
Each pair of grid electrodes 110a-d may be substantially similar or identical to the grid electrodes 110 described above. The grid electrodes 110a are positioned on the substrate 701 on opposing sides of a hypothetical centerplane 602a in a mutually parallel orientation. Similarly, the grid electrodes 110d are positioned on the substrate 701 on opposing sides of a hypothetical centerplane 604a in a mutually parallel orientation. The grid electrodes 110b and 110c are positioned on the substrate 701 such that each individual electrode substantially coincides with or is proximate a central axis of an opposing set of lenses 120a-d. The four sets of lenses 120a-d are positioned on the substrate 701 in an opposing, staggered manner.
The orientation of the four pairs of grid electrodes 110a-d and the four sets of lenses 120a-d is best explained by describing the ion path 706 of an ion emitted from the ion source 602 as the ion travels through the grid electrodes 110a-d and lenses 120a-d to or towards the ion detector 604. That is, as an ion is emitted from the ion source 602, it first travels through the grid electrodes 110a. The lenses 120a then reflect the ion towards an opposite direction, such that the ion travels through the grid electrodes 110a in the opposite direction, ultimately to travel through the grid electrodes 110b. The lenses 120b then reflect the ion towards another direction that is substantially parallel to the ions initial direction (when emitted from the ion source 602), ultimately to travel through the grid electrodes 110c. The lenses 120c then reflect the ion towards an opposite direction, ultimately to travel through the grid electrodes 110d. The lenses 120d then reflect the ion towards the ion deflector 604.
The exemplary embodiment depicted in
In each of the exemplary embodiments described above and other embodiments within the scope of the present disclosure, the thickness of the ion reflection lenses and/or the grid electrodes may range between about 5 μm and about 100 μm. For example, the thickness may be about 50 μm. This decreased size relative to past attempts at constructing reflectrons is advantageous in that the overall size of the device can be significantly smaller than previously thought possible. Accordingly, applications utilizing apparatus within the scope of the present disclosure can enable remote and/or mobile TOF mass spectrometers not previously possible.
In view of all of the above, it should be evident that the present disclosure introduces a microelectronics apparatus comprising a substrate, a pair of grid electrodes coupled to the substrate on opposing sides of a central axis, wherein the grid electrodes are substantially parallel to each other and extend substantially perpendicular from the substrate, and a plurality of ion reflection lenses each coupled to the substrate, wherein each ion reflection lens: (1) is substantially perpendicular to each of the grid electrodes; (2) extends substantially perpendicular from the substrate; and (3) has an aperture aligned with the central axis.
The present disclosure also introduces a method of manufacturing a microelectronics comprising coupling an ion source and an ion detector to a substrate, coupling a pair of grid electrodes to the substrate on opposing sides of a central axis of the ion source, and coupling a plurality of ion reflection lenses to the substrate in series such that the grid electrodes interpose the ion source and the plurality of ion reflection lenses, wherein the grid electrodes and the ion reflection lenses are electrically biased to collectively direct ions emitted from the ion source to travel through the grid electrodes and the ion reflection lenses back towards the ion detector.
The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.
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