BUCKLING BEAM PROBE ARRAYS AND METHODS FOR MAKING SUCH ARRAYS INCLUDING FORMING PROBES WITH LATERAL POSITIONS MATCHING GUIDE PLATE HOLE POSITIONS
Forming buckling beam probe arrays having MEMS probes engaged with guide plates during formation or after formation of the probes while the probes are held in the array configuration in which they were formed is disclosed. Probes can be formed in, or laterally aligned with, guide plate through holes. Guide plate engagement can occur by longitudinally locating guide plates on probes that are partially formed or fully formed with exposed ends, by forming probes within guide plate through holes, by forming guide plates around probes, or forming guide plates in lateral alignment with arrayed probes and then longitudinally engaging the probes and the through holes of the guide plates. Arrays can include probes and a substrate to which the probes are bonded with one or more guide plates. Final arrays can include probes held by guide plates with aligned or laterally shifted hole patterns.
This application is a continuation of U.S. application Ser. No. 17/240,962, filed Apr. 26, 2021, which claims the benefit of U.S. Provisional Patent Application No. 63/015,450 filed on Apr. 24, 2020, the disclosures of both of which are incorporated herein by reference in their entireties.
TECHNICAL FIELDThe present invention relates generally to the field of buckling beam probe arrays or subarrays for testing (e.g. wafer level testing or socket testing) of electronic components (e.g. integrated circuits), more particularly formation of such arrays or subarrays including vertical MEMS probes fabricated with probe-to-probe lateral positions matching guide plate through hole positions.
BACKGROUND Probes:Numerous electrical contact probe and pin configurations as well as array formation methods have been commercially used or proposed, some of which may be prior art while others are not. Examples of such pins, probes, arrays, and methods of making are set forth in the following patent applications, publications of applications, and patents. Each of these applications, publications, and patents is incorporated herein by reference as if set forth in full herein.
Electrochemical fabrication techniques for forming three-dimensional structures from a plurality of adhered layers have been, and are being, commercially pursued by Microfabrica® Inc. (formerly MEMGen Corporation) of Van Nuys, California under the process names EFAB and MICA FREEFORM®.
Various electrochemical fabrication techniques were described in U.S. Pat. No. 6,027,630, issued on Feb. 22, 2000 to Adam Cohen.
A related method for forming microstructures using electrochemical fabrication techniques is taught in U.S. Pat. No. 5,190,637 to Henry Guckel, entitled “Formation of Microstructures by Multiple Level Deep X-ray Lithography with Sacrificial Metal Layers”.
Other methods for forming three-dimensional structures were described in U.S. patent application Ser. No. 10/272,255 (Microfabrica Docket No. P-US035-A-SC), Ser. No. 10/272,254 (P-US036-A-MG), and Ser. No. 10/271,574 (P-US037-A-MG), now respectively U.S. Pat. Nos. 7,163,614, 7,172,684, and 7,288,178. These patents describe electrochemical extrusion (or ELEX) methods that may be used to form elongated structures with vertical, curved, or even stair-stepped configurations.
A first example of such an ELEX method is illustrated in
After the deposition thickens to a desired height, the substrate and the mask begin to separate at a desired rate. The average rate of separation is preferably approximately equal to the average rate of deposition such that a deposition zone and a location on the mask surface stay in the same approximate position throughout the deposition operation with the exception of the initial portion of the deposition that occurs before movement begins. During separation, the sidewalls 232 of the mask seal with the sidewalls 234 of the growing deposit 238 such that the electrolyte does not enter the bellows chamber 212. In one embodiment, the deposition rate and the movement occur in such a manner that the position of the deposition stays at a position 240 relative to the face surface 236 of the mask resulting in a separation of “L”. In other embodiments though, the average deposition rate and the separation rate are approximately equal, and actual separation may occur in discrete and discontinuous steps while the deposition may occur in a continuous manner or in a discontinuous manner. Deposition and movement may occur in an alternating manner at different times. In some embodiments, the working surface may extend into the support region of the mask.
A second example of an ELEX method is set forth in
Electrochemical fabrication provides the ability to form prototypes and commercial quantities of miniature objects, parts, structures, devices, and the like, at reasonable costs and in reasonable times. In fact, electrochemical fabrication is an enabler for the formation of many structures that were hitherto impossible to produce. Electrochemical fabrication opens the spectrum for new designs and products in many industrial fields. Even though electrochemical fabrication offers this new capability and it is understood that electrochemical fabrication techniques can be combined with designs and structures known within various fields to produce new structures, certain uses for electrochemical fabrication provide designs, structures, capabilities and/or features not known or obvious in view of the state of the art.
A need exists in various fields for miniature devices having improved characteristics, improved operational capabilities, reduced fabrication times, reduced fabrication costs, simplified fabrication processes, greater versatility in device design, improved selection of materials, improved material properties, more cost effective and less risky production of such devices, and/or more independence between geometric configuration and the selected fabrication process.
SUMMARYIt is a first object of some embodiments of the invention to provide an improved method of forming buckling beam probe arrays with MEMS probes that are built up with lateral positions of probes, at one or more longitudinal heights, corresponding to through holes associated with guide plates that may be engaged with the probes during formation of the probes or after formation of the probes.
It is a second object of some embodiments of the invention to provide one or more guide plates directly or indirectly on a build substrate and thereafter to form an array of probes in lateral alignment with the one or more guide plates wherein: (1) one longitudinal end of each of the probes extends into, or possibly completely through, the holes in the one or more guide plates when those ends are formed, or (2) the probes do not extend into the holes in the one or more guide plates upon formation but extend into the holes after at least partial or complete formation of the probes (e.g. upon removal of a portion of a material that holds the probes in their relative lateral positions which could be followed by relative movement of the guide plate with respect to a local longitudinal axis of the probes or a longitudinal axis of the probe array as a whole).
It is an object of some embodiments of the invention to laterally align one or more guide plates and MEMS probes after only partial longitudinal formation of the probes in an array configuration; and then after such lateral alignment, finishing the longitudinal formation of the probes wherein: (1) a portion of a masking or sacrificial material is removed after the lateral alignment of the one or more guide plates to the probes which in turn allows the one or more guide plates to be moved longitudinally so that probes extend at least partially into the through holes, if not completely through the holes, of the one or more guide plates, and thereafter continuing longitudinal formation of the probes, or (2) prior to laterally aligning the partially formed probes and the one or more guide plates, exposing the ends of the probes so that they may be engaged with one or more guide plates, and then laterally and longitudinally aligning the probes and the guide plates such that the ends of the partially formed probes extend at least part way into the holes, if not completely through holes, and thereafter continuing longitudinal formation of the probes.
It is an object of some embodiments of the invention to laterally and longitudinally align one or more guide plates with a plurality of completed MEMS probes that were formed together with positions corresponding to holes existing in guide plates or that will be made to exist in guide plates wherein: (1) a portion of a masking or sacrificial material is removed after the lateral alignment of the one or more guide plates to the probes which in turn allows the one or more guide plates to be relatively moved longitudinally so that probes extend at least partially into the through holes, after which, if necessary, further removal of masking or sacrificial material may occur to allow further longitudinal engagement of probes with the one or more guide plates, or (2) prior to laterally aligning the formed probes and the one or more guide plates, exposing the ends of the probes so that they may be engaged with one or more guide plates, and then laterally and longitudinally aligning the probes and the guide plates such that the ends of the probes extend at least part way into the holes, if not completely through holes, and thereafter, if necessary, continuing the removal of masking or sacrificial material to allow further longitudinal engagement of the probes with the one or more guide plates.
It is an object of some embodiments of the invention to form one or more guide plates while in lateral alignment with probe arrays where: (1) one or more guide plates are formed directly or indirectly on a probe substrate prior to the formation of the probes, (2) one or more guide plates are formed in lateral alignment with partially formed probes and are then moved longitudinally such that ends of the partially formed probes at least partially extend into the through holes of the one or more guide plates, (3) one or more guide plates are formed in lateral alignment and longitudinal alignment with the partially formed probes such that the ends of the partially formed probes at least partially extend into the through holes of the one or more guide plates, (4) one or more guide plates are formed in lateral alignment with completed probes and are then moved longitudinally such that ends of the formed probes extend through the through holes of the one or more guide plates, or (5) one or more guide plates are formed in lateral alignment and longitudinal alignment with the completed probes such that the ends of the partially formed probes extend through the through holes of the one or more guide plates as the guide plates are formed.
It is an object of some embodiments of the invention to form one or more guide plates while in lateral alignment with probe arrays where the formation of the one or more guide plates includes: (1) locating a plate of material relative to the probes and then forming through holes in the plate in lateral alignment with the locations of the probes in the probe array, (2) providing coating over the end of completed or partially formed probes to provide a temporary expansion of probe cross-section in the longitudinal position of the probes where guide plate formation is to occur, locating at least one guide plate material in depositable, flowable, spreadable, or sprayable form around at least part of the expanded cross-sectional portions of the probes; solidifying the guide plate material if not solidified upon deposition; and possibly planarizing the guide plate material before or after solidification, or (3) at a longitudinal level not occupied by probes or partially formed probes, locating a masking material in locations where through holes of a guide plate are to exist; locating at least one guide plate material in depositable, flowable, spreadable, or sprayable form around the sides of the masking material; solidifying the guide plate material if not solidified upon deposition; and possibly planarizing the guide plate material before or after solidification and thereafter removing the masking material and positioning the guide plate longitudinally to engage the partially, or completely, formed probes.
It is an object of some embodiments of the invention to provide improved methods of simultaneously engaging a plurality of partially formed or fully formed probes with one or more guide plates having through holes set in an intended array configuration.
It is an object of some embodiments of the invention to ensure that completely formed probes or partially formed probes are in an intended array configuration at the time of engaging one or more guide plates having that configuration.
It is an object of some embodiments of the invention to provide probe arrays having (1) at least one substrate to which a plurality of probes are bonded and at least one guide plate through which the plurality of probes extend and which together define an array configuration for the probes, or (2) at least a plurality of guide plates through which a plurality of probes extend to set an array configuration for the plurality of probes; and wherein the probes and the at least one guide plate have an interface that provides both lateral positioning of the probes and controlled longitudinal movement of the probes in at least one direction and, in some cases, in both directions.
It is an object of some embodiments of the invention to provide probe arrays having (1) at least one substrate to which a plurality of probes are bonded and at least one guide plate through which the plurality of probes extend and which together define an array configuration for the probes, or (2) at least a plurality of guide plates through which a plurality of probes extend to set an array configuration for the plurality of probes, wherein the probes extend, at least in part, longitudinally in a direction of layer stacking and wherein interfaces between the probes and the one or more guide plates are configured so that no layer-to-layer offset, or variation in layer-to-layer configuration unintentionally inhibits smooth motion of the probes through the one or more guide plates over a working range of motion where (1) the multi-layer probe is configured to have no layer boundary that would move past the edge of a guide plate over a working range of motion; or (2) the multi-layer probe has no layer boundary that moves past an edge of the guide plate where a lateral step in motion would occur (e.g. any portion moving from inside the hole to outside the hole would not have any significant step or the step would be inward so that the portion would not contact the guide plate when moving longitudinally in and out).
It is an object of some embodiments of the invention to provide lateral alignment and then simultaneous and longitudinal engagement of at least one guide plate with a plurality of MEMS probes or partially formed MEMS probes, where the probes are formed in a lateral array configuration, and thereafter, if required, causing a lateral movement of at least one guide plate with respect to another guide plate or with respect to a substrate so as to provide a desired lateral shifting of opposite ends of the probes compared to their initial positions, and then fixing or retaining the guide plate or plates and/or substrate in final lateral configurations.
It is an object of some embodiments of the invention to reduce errors in probe placement prior to engaging probes and guide plates.
It is an object of some embodiments of the invention to reduce the time and/or effort of producing buckling beam probe arrays.
It is an object of some embodiments of the invention to reduce the cost of production of forming buckling beam probe arrays or probe heads.
It is an object of some embodiments of the invention to provide improved methods of fabricating probe arrays. Some such methods may include use of only (i.e. be limited to) multi-layer, multi-material electrochemical fabrication methods that fabricate the entire probe arrays in fully configured states. Other methods may combine separately formed arrays (or subarrays) laterally with other arrays (or subarrays) to formed large tiled arrays where lateral subarray combining may occur after sacrificial material release prior to sacrificial material release, before or after lateral shifting of guide plates relative to other guide plates or substrates. Other methods may include in situ steps or operations or post layer steps or operations that provide for conformable coating of specialized materials over probe elements, selected portions of probes or entire probes (e.g. dielectrics for isolation of probes from one another, dielectrics for electrical isolation of a portion of one probe from another portion of the same probe, e.g. for coaxial configurations, contact materials, bonding materials, adhesion enhancement materials, barrier materials, and the like). Other methods may include formation of intentionally extended single layer contact surfaces that allow uninhibited movement of slidable probe components even in the presence of unintended layer features (e.g. layer-to-layer offsets or non-perpendicular intra-layer wall configurations). Still other methods may include setting probe orientation relative to layer planes and layer stacking directions to allow optimal creation of probe and array features. Other steps or operations may be provided or features formed in probes, probe arrays, or guide plates that provide features of opposed slidable, or otherwise movable, probe elements in build locations that allow minimum feature size gaps to exist which are larger than gaps desired when the probes are in operational configurations along with formation of spring loaded stops, snap-together features, or other structures that allow enforcement of working locations or working regions that are distinct from build locations.
Other objects and advantages of various embodiments of the invention will be apparent to those of skill in the art upon review of the teachings herein. The various embodiments of the invention, set forth explicitly herein or otherwise ascertained from the teachings herein, may address one or more of the above objects alone or in combination, or alternatively may address some other object ascertained from the teachings herein. It is not intended that all objects, or even multiple objects, be addressed by any single aspect or embodiment of the invention even though that may be the case regarding some aspects.
In a first set of aspects, steps, functionalities, or features as set forth in the generalized embodiments, alternative implementations of those generalized embodiments, the specific embodiments, or alternative implementations of those specific embodiments are included.
In a second set of aspects of the invention, a method of forming a probe array having at least one guide plate includes the steps, functionality, and/or features noted in the above objects of the invention as (1) individually set forth, (2) set forth in separate alternatives noted with regard to some objectives, or (3) set forth in a combination of such objectives or separate alternatives for those objectives, so long as the combination does not completely remove all the benefits offered by each of the separate objectives or alternatives.
In a third set of aspects, a probe array is provided that has at least one guide plate and includes the functionality or features noted in the above objects of the invention as (1) individually set forth, (2) set forth in separate alternatives noted with regard to some objectives, or (3) set forth in a combination of such objectives or separate alternatives for those objectives, so long as the combination does not completely remove all the benefits offered by each of the separate objectives or alternatives.
In a fourth set of aspects, subcombinations of steps, functionalities, or features as set forth in the generalized embodiments, alternative implementations of those generalized embodiments, the specific embodiments, or alternative implementations of those specific embodiments are included in a combination or subcombination in any functional manner to achieve one of the objectives noted herein, or as ascertained from the teachings herein (directly set forth or set forth by incorporation).
In another aspect of the invention, a method of forming a two-dimensional probe array, includes: (A) forming a plurality of probes on a substrate with each probe having two ends, and at least one intermediate elastically compliant portion, wherein at least one of the ends being configured as a contact end for making electric contact to a second electrical circuit element while the other end is selected from the group consisting of: (1) a contact end for making pressure based contact to a first electric element, and (2) an attachment end for making a fixed contact to the first circuit element, wherein the probes are formed with probe-to-probe spacings corresponding to contacts on the second circuit element, wherein the formation of the plurality of probes, includes: (i) forming one or more multi-material layers, with any successively formed multi-material layers adhered to a previously formed multi-material layer or a non-multi-material layer that in turn was adhered directly or indirect to a previously formed multi-material layer, and with each multi-material layer comprising at least two materials, at least one of which is at least one structural material and at least one other of which is at least one sacrificial material, wherein each multi-material layer defines a cross-section of the plurality of probes, wherein the forming of each multi-material layer includes: (a) depositing at least a first of the at least two materials; (b) depositing at least a second of the at least two materials; (c) planarizing at least two of the at least two deposited materials, including planarizing at least one structural material and at least one sacrificial material; (ii) after formation of all layers of the probes, separating the probes from any sacrificial material that was not removed during the formation of the one or more multi-material layers; (B)
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- providing at least one array guide plate having a plurality of openings, and engaging the openings of the at least one guide plate around the probes at a longitudinal level, wherein the providing and the engaging of the probes and the at least one guide plate and the probes is selected from the group consisting of: (i) after forming the probes to have a full length, positioning a guide plate laterally and longitudinally over and around ends of the probes, with an end of the probes extending from unremoved sacrificial material by an amount selected from the group consisting of: (a) less than a lateral dimension of an individual probe; (b) less than a lateral dimension of a spacing between adjacent probes; (c) less than a fraction of a height of a probe where the fraction is selected from the group consisting of (1) ½, (2) ⅓, (3) ¼, (4) ⅕, (5) 1/10, and (6) 1/20; (d) less than N thicknesses of the guide plate, wherein N is selected from the group consisting of (1) 4, (2) 3, (3) 2, (4) 1, (5) ½, (6) ⅓, and (7) ¼; and (e) less than an amount selected from the group consisting of 500 microns, 200 microns, 100 microns, 50, microns, 20 microns, 10 microns, and 5 microns; (ii) after forming the probes to have only a partial length, positioning a guide plate laterally and longitudinally over and around the ends of the partial length probes, then completing formation of the length of the probes, wherein at the time of positioning of the guide plate, an end of the probes extends from unremoved sacrificial material by an amount selected from the group consisting of: (a) less than a lateral dimension of an individual probe; (b) less than a lateral dimension of a spacing between adjacent probes; (c) less than a fraction of a height of a probe where the fraction is selected from the group consisting of (1) ½, (2) ⅓, (3) ¼, (4) ⅕, (5) 1/10, and (6) 1/20; (d) less than N thicknesses of the guide plate, wherein N is selected from the group consisting of (1) 4, (2) 3, (3) 2, (4) 1, (5) ½, (6) ⅓, and (7) ¼; and (e) less than an amount selected from the group consisting of (1) 500 microns, (2) 200 microns (3) 100 microns, (4) 50, microns, (5) 20 microns, (6) 10 microns, and (7) 5 microns; (iii) prior to forming a first layer of the probes position the guide plate over the substrate, in direct or indirect contact therewith, and then forming the probes through openings in the guide plate; (iv) after forming the probes to have a full length, forming a guide plate with openings aligned laterally with the probes and positioned longitudinally with the openings at least partially surrounding portions of the probes; (v) after forming the probes to have a full length, forming a guide plate with openings aligned laterally with the probes and positioned longitudinally with the openings at least partially surrounding portions of the probes wherein only a longitudinal portion of the probes extend from sacrificial material at the time of guide plate formation, wherein the portion is selected from the group consisting of: (a) less than a lateral dimension of an individual probe; (b) less than a lateral dimension of a closest spacing between adjacent probes; (c) less than a fraction of a height of a probe where the fraction is selected from the group consisting of (1) ½, (2) ⅓, (3) ¼, (4) ⅕, (5) 1/10, and (6) 1/20; (d) less than N thicknesses of the guide plate, wherein N is selected from the group consisting of (1) 4, (2) 3, (3) 2, (4) 1, (5) ½, (6) ⅓, and (7) ¼; and (e) less than an amount selected from the group consisting of (1) 500 microns, (2) 200 microns (3) 100 microns, (4) 50, microns, (5) 20 microns, (6) 10 microns, and (7) 5 microns; (vi) after forming the probes to have only a partial length, forming a guide plate over ends of the partial length probes, then completing formation of the length of the probes, wherein at the time of positioning of the guide plate, an end of the partially formed probes extends from unremoved sacrificial material by an amount selected from the group consisting of: (a) less than a lateral dimension of an individual probe; (b) less than a lateral dimension of a spacing between adjacent probes; (c) less than a fraction of a height of a probe where the fraction is selected from the group consisting of (1) ½, (2) ⅓, (3) ¼, (4) ⅕, (5) 1/10, and (6) 1/20; (d) less than N thicknesses of the guide plate, wherein N is selected from the group consisting of (1) 4, (2) 3, (3) 2, (4) 1, (5) ½, (6) ⅓, and (7) ¼; and (e) less than an amount selected from the group consisting of (1) 500 microns, (2) 200 microns (3) 100 microns, (4) 50, microns, (5) 20 microns, (6) 10 microns, and (7) 5 microns; (vii) prior to forming a first layer of the probes forming the guide plate over the substrate, in direct or indirect contact therewith, and then forming the probes through openings in the guide plate; and (vii) after forming the probes to at least partial length, forming a guide plate with openings aligned laterally with the probes but longitudinally above the ends of the probes, and thereafter exposing the ends of the probes by removing a portion of the sacrificial material, and lowering the guide plate longitudinally over and around the ends of the probes.
Other aspects of the invention will be understood by those of skill in the art upon review of the teachings herein and for example may include alternatives in the configurations or processes set forth herein, decision branches noted in those processes or configurations, or partial or complete exclusion of such alternatives and/or decision branches in favor of explicitly setting forth process steps or features along with orders to be used in performing such steps or connections between such features. Some aspects may provide device counterparts to method of formation aspects, some aspects may provide method of formation counterparts to device aspects, and other aspects may provide for methods of use for the probe arrays providing herein.
An example of a multi-layer, multi-material electrochemical fabrication process was provided above in conjunction with the illustrations of
Various embodiments of various aspects of the invention are directed to formation of three-dimensional structures from materials, some, or all, of which may be electrodeposited or electroless deposited (as illustrated in
The various embodiments, alternatives, and techniques disclosed herein may form multi-layer structures using a single patterning technique on all layers or using different patterning techniques on different layers. For example, various embodiments of the invention may perform selective patterning operations using conformable contact masks and masking operations (i.e. operations that use masks which are contacted to but not adhered to a substrate), proximity masks and masking operations (i.e. operations that use masks that at least partially selectively shield a substrate by their proximity to the substrate even if contact is not made), non-conformable masks and masking operations (i.e. masks and operations based on masks whose contact surfaces are not significantly conformable), adhered masks and masking operations (masks and operations that use masks that are adhered to a substrate onto which selective deposition or etching is to occur as opposed to only being contacted to it), and/or selective patterned deposition of materials (e.g. via extrusion, jetting, or controlled electrodeposition) as opposed to masked patterned deposition. Conformable contact masks, proximity masks, and non-conformable contact masks share the property that they are preformed and brought to, or in proximity to, a surface which is to be treated (i.e. the exposed portions of the surface are to be treated). These masks can generally be removed (for one or more reuses) without damaging the mask or the surface that received treatment to which they were contacted or located in proximity to. Adhered masks are generally formed on the surface to be treated (i.e. the portion of that surface that is to be masked) and bonded to that surface such that they cannot be separated from that surface without being completely destroyed or damaged beyond any point of reuse. Adhered masks may be formed in a number of ways, including: (1) by application of a photoresist, selective exposure of the photoresist, and then development of the photoresist; (2) selective transfer of pre-patterned masking material; (3) direct formation of masks from computer-controlled depositions of material; and/or (4) laser ablation of a deposited material. In some embodiments, or during the formation of some layers, structural material may be deposited directly into mask openings as illustrated in
Patterning operations may be used in selectively depositing material and/or may be used in the selective etching of material. Selectively etched regions may be selectively filled in or filled in via blanket deposition, or the like, with a different desired material. In some embodiments, the layer-by-layer build up may involve the simultaneous formation of portions of multiple layers. In some embodiments, depositions made in association with some layer levels may result in depositions to regions associated with other layer levels (i.e. regions that lie within the top and bottom boundary levels that define a different layer's geometric configuration). Such use of selective etching and/or interlaced material deposition in association with multiple layers is described in U.S. patent application Ser. No. 10/434,519 (P-US068-A-MG), by Smalley, filed May 7, 2003, which is now U.S. Pat. No. 7,252,861, and which is entitled “Methods of and Apparatus for Electrochemically Fabricating Structures Via Interlaced Layers or Via Selective Etching and Filling of Voids”. This referenced application is incorporated herein by reference.
Temporary substrates on which structures may be formed may be of the sacrificial-type (i.e. destroyed or damaged during separation of deposited materials to the extent they cannot be reused), non-sacrificial-type (i.e. not destroyed or excessively damaged, i.e. not damaged to the extent they may not be reused, e.g. with a sacrificial or release layer located between the substrate and the initial layers of a structure that is formed). Non-sacrificial substrates may be considered reusable, with little or no rework (e.g. replanarizing one or more selected surfaces or applying a release layer, and the like) though they may or may not be reused for a variety of reasons.
Definitions of various terms and concepts that may be used in understanding the embodiments of the invention (either for the devices themselves, certain methods for making the devices, or certain methods for using the devices) will be understood by those of skill in the art. Some such terms and concepts are discussed herein while other such terms are addressed in the various patent applications to which the present application claims priority and/or which are incorporated herein by reference.
The term “longitudinal” as used herein refers to a long dimension of a probe, an end-to-end dimension of the probe, or a tip-to-tip dimension. Longitudinal may refer to a generally straight line that extends from one end of the probe to another end of the probe or it may refer to a curved or stair-stepped path that has a sloped or even changing direction along a height of the probe. When referring to probe arrays, the longitudinal dimension may refer to a particular direction the probes in the array point or extend, but it may also simply refer to the overall height of the array that starts at a plane containing a first end, tip, or base of a plurality of probes and extends perpendicular thereto to a plane containing a second end, tip, or top of the probes. The context of use typically makes clear what is meant especially to those of skill in the art. It is intended that the interpretation to be applied to the term herein be as narrow as warranted by the details of the description provided or the context in which the term is used. If however, no such narrow interpretation is warranted, it is intended that the broadest reasonable scope of interpretation apply.
The term “lateral” as used herein is related to the term longitudinal. In terms of the stacking of layers, lateral refers to a direction within each layer, or two perpendicular directions within each layer (i.e. one or more directions that lie within a plane of a layer that are substantially perpendicular to the longitudinal direction). When referring to probe arrays, laterally generally has a similar meaning in that a lateral dimension is generally a dimension that lies in a plane that is parallel to a plane of the top or bottom of the array (i.e. substantially perpendicular to the longitudinal dimension). When referring to probes themselves, the lateral dimensions may be those that are perpendicular to an overall longitudinal axis of the probe, a local longitudinal axis of the probe (that is local lateral dimensions), or simply the dimensions similar to those noted for arrays or layers. The context of use typically makes clear what is meant especially to those of skill in the art. It is intended that the interpretation to be applied to the term herein be as narrow as warranted by the details of the description provided or the context in which the term is used. If no such narrow interpretation is warranted, it is intended that the broadest reasonable scope of interpretation apply.
Generalized Probe Array and Probe Array Formation EmbodimentsProbe arrays, methods of making probe arrays, and methods of using probe arrays can take on different forms in different embodiments of the invention.
In summary, the general process flow of
The variations of
To further enhance understanding of the scope of the generalized embodiments discussed above, specific illustrative examples are set forth below.
Numerous variations of the above specific embodiments are possible and include, intra alia, for example, (1) many of the alternatives discussed above with regard to
Various other embodiments of the present invention exist. Some of these embodiments may be based on a combination of the teachings herein with various teachings incorporated herein by reference. For example, some fabrication embodiments may not use any blanket deposition process. Some embodiments may use selective deposition processes or blanket deposition processes on some layers that are not electrodeposition processes. Some embodiments may use nickel or nickel-cobalt as a structural material while other embodiments may use different materials. For example, preferred spring materials include nickel (Ni), copper (Cu), beryllium copper (BeCu), nickel phosphorous (Ni—P), tungsten (W), aluminum copper (Al—Cu), steel, P7 alloy, palladium, palladium-cobalt, silver, molybdenum, manganese, brass, chrome, chromium copper (Cr—Cu), and combinations of these. Some embodiments may use copper as the structural material with or without a sacrificial material. Some embodiments, for example, may use nickel, nickel-phosphorous, nickel-cobalt, palladium, palladium-cobalt, gold, copper, tin, silver, zinc, solder, rhodium, rhenium as structural materials while other embodiments may use different materials. Some embodiments, for example, may use copper, tin, zinc, solder or other materials as sacrificial materials. Some embodiments may use different structural materials on different layers or on different portions of single layers. Some embodiments may remove a sacrificial material while other embodiments may not. Some embodiments may use photoresist, polyimide, glass, ceramics, other polymers, and the like as dielectric structural materials.
Structural or sacrificial dielectric materials may be incorporated into embodiments of the present invention in a variety of different ways. Such materials may form a third material or higher deposited material on selected layers or may form one of the first two materials deposited on some layers. Additional teachings concerning the formation of structures on dielectric substrates and/or the formation of structures that incorporate dielectric materials into the formation process and possibly into the final structures as formed are set forth in a number of patent applications filed Dec. 31, 2003: (1) U.S. Patent Application No. 60/534,184 which is entitled “Electrochemical Fabrication Methods Incorporating Dielectric Materials and/or Using Dielectric Substrates”; (2) U.S. Patent Application No. 60/533,932, which is entitled “Electrochemical Fabrication Methods Using Dielectric Substrates”; (3) U.S. Patent Application No. 60/534,157, which is entitled “Electrochemical Fabrication Methods Incorporating Dielectric Materials”; (4) U.S. Patent Application No. 60/533,891, which is entitled “Methods for Electrochemically Fabricating Structures Incorporating Dielectric Sheets and/or Seed layers That Are Partially Removed Via Planarization”; and (5) U.S. Patent Application No. 60/533,895, which is entitled “Electrochemical Fabrication Method for Producing Multi-layer Three-Dimensional Structures on a Porous Dielectric”. These patent filings are each hereby incorporated herein by reference as if set forth in full herein.
Additional patent filings that provide, intra alia, teachings concerning incorporation of dielectrics into electrochemical fabrication processes include: (1) U.S. patent application Ser. No. 11/139,262 (P-US144-A-MF), by Lockard, et al., which was filed May 26, 2005, now U.S. Pat. No. 7,501,328, and which is entitled “Methods for Electrochemically Fabricating Structures Using Adhered Masks, Incorporating Dielectric Sheets, and/or Seed Layers that are Partially Removed Via Planarization”; (2) U.S. patent application Ser. No. 11/029,216 (P-US128-A-MF), by Cohen, et al., which was filed Jan. 3, 2005, now abandoned, and which is entitled “Electrochemical Fabrication Methods Incorporating Dielectric Materials and/or Using Dielectric Substrates”; (3) U.S. patent application Ser. No. 11/028,957 (P-US127-A-SC), by Cohen, which was filed on Jan. 3, 2005, now abandoned, and which is entitled “Incorporating Dielectric Materials and/or Using Dielectric Substrates”; (4) U.S. patent application Ser. No. 10/841,300 (P-US099-A-MF), by Lockard et al., which was filed on May 7, 2004, now abandoned, and which is entitled “Methods for Electrochemically Fabricating Structures Using Adhered Masks, Incorporating Dielectric Sheets, and/or Seed Layers that are Partially Removed Via Planarization”; (5) U.S. patent application Ser. No. 10/841,378 (P-US106-A-MF), by Lembrikov et al., which was filed on May 7, 2004, now U.S. Pat. No. 7,527,721, and which is entitled “Electrochemical Fabrication Method for Producing Multi-layer Three-Dimensional Structures on a Porous Dielectric; (6) U.S. patent application Ser. No. 11/325,405 (P-US152-A-MF), filed Jan. 3, 2006 by Dennis R. Smalley, now abandoned, and entitled “Method of Forming Electrically Isolated Structures Using Thin Dielectric Coatings”; (7) U.S. patent application Ser. No. 10/607,931 (P-US075-A-MG), by Brown, et al., which was filed on Jun. 27, 2003, now U.S. Pat. No. 7,239,219, and which is entitled “Miniature RF and Microwave Components and Methods for Fabricating Such Components”, (8) U.S. patent application Ser. No. 10/841,006 (P-US104-A-MF), by Thompson, et al., which was filed on May 7, 2004, now abandoned, and which is entitled “Electrochemically Fabricated Structures Having Dielectric or Active Bases and Methods of and Apparatus for Producing Such Structures”; (9) U.S. patent application Ser. No. 10/434,295 (P-US061-A-MG), by Cohen, which was filed on May 7, 2003, now abandoned, and which is entitled “Method of and Apparatus for Forming Three-Dimensional Structures Integral With Semiconductor Based Circuitry”; and (10) U.S. patent application Ser. No. 10/677,556 (P-US081-A-MF), by Cohen, et al., filed Oct. 1, 2003, now abandoned, and which is entitled “Monolithic Structures Including Alignment and/or Retention Fixtures for Accepting Components”. These patent filings are each hereby incorporated herein by reference as if set forth in full herein.
Some embodiments may employ diffusion bonding or the like to enhance adhesion between successive layers of material. Various teachings concerning the use of diffusion bonding in electrochemical fabrication processes are set forth in U.S. patent application Ser. No. 10/841,384 (P-US103-A-SC) which was filed May 7, 2004 by Cohen et al., now abandoned, which is entitled “Method of Electrochemically Fabricating Multilayer Structures Having Improved Interlayer Adhesion” and which is hereby incorporated herein by reference as if set forth in full. This application is hereby incorporated herein by reference as if set forth in full.
The patent applications and patents set forth below are hereby incorporated by reference herein as if set forth in full. The teachings in these incorporated applications can be combined with the teachings of the instant application in many ways: For example, enhanced methods of producing structures may be derived from some combinations of teachings, enhanced structures may be obtainable, enhanced apparatus may be derived, enhanced methods of using may be implemented, and the like.
It will be understood by those of skill in the art that additional operations may be used in variations of the above presented method of making embodiments. These additional operations may, for example, perform cleaning functions (e.g. between the primary operations discussed herein or discussed in the various materials incorporated herein by reference), perform activation functions and monitoring functions, and the like.
It will also be understood that the probe elements of some aspects of the invention may be formed with processes which are very different from the processes set forth herein, and it is not intended that structural aspects of the invention need to be formed by only those processes taught herein or by processes made obvious by those taught herein.
Though various portions of this specification have been provided with headers, it is not intended that the headers be used to limit the application of teachings found in one portion of the specification from applying to other portions of the specification. For example, alternatives acknowledged in association with one embodiment are intended to apply to all embodiments to the extent that the features of the different embodiments make such applications functional and do not otherwise contradict or remove all benefits of the adopted embodiment. Various other embodiments of the present invention exist. Some of these embodiments may be based on a combination of the teachings set forth herein with various teachings incorporated herein by reference.
It is intended that any aspects of the invention set forth herein represent independent invention descriptions which Applicant contemplates as full and complete invention descriptions that Applicant believes may be set forth as independent claims without need of importing additional limitations or elements, from other embodiments or aspects set forth herein, for interpretation or clarification other than when explicitly set forth in such independent claims once written. It is also understood that any variations of the aspects set forth herein represent individual and separate features that may form separate independent claims, be individually added to independent claims, or be added as dependent claims to further define an invention being claimed by those respective dependent claims should they be written.
In view of the teachings herein, many further embodiments, alternatives in design and uses of the embodiments of the instant invention will be apparent to those of skill in the art. As such, it is not intended that the invention be limited to the particular illustrative embodiments, alternatives, and uses described above but instead that it be solely limited by the claims presented hereafter.
Claims
1. A method of forming a probe array, the method comprising:
- (A) forming a plurality of probes on a substrate with each probe having two ends, and at least one intermediate elastically compliant portion, wherein at least one of the ends is configured as a contact end for making electric contact to a second electrical circuit element while an other end is selected from a group consisting of: (1) a contact end for making pressure based contact to a first electric element, and (2) an attachment end for making a fixed contact to the first circuit element, wherein the plurality of probes are formed with probe-to-probe spacings corresponding to contact elements on the second circuit element, wherein the formation of the plurality of probes, comprises: forming a plurality of multi-material layers, with each multi-material layer comprising at least two materials, wherein at least one of the at least two materials is at least one structural material and at least one other of the at least two materials is at least one sacrificial material, wherein each multi-material layer defines a cross-section of the plurality of probes;
- (B) providing at least one guide plate having a plurality of openings to engage the plurality of probes; and
- (C) after formation of all multi-material layers of the probes and after providing and engaging the at least one guide plate, separating the probes from unremoved sacrificial material;
- wherein (B) providing at least one guide plate is selected from a group consisting of: (i) after forming the probes but prior to the removal of all sacrificial material from the plurality of multi-material layers, positioning the at least one guide plate laterally and longitudinally over and around end portions of the probes with the end portions of the probes extending from unremoved sacrificial material; (ii) prior to forming a first layer of the plurality of multi-material layers of the probes forming the at least one guide plate over the substrate, in direct or indirect contact therewith, and then forming the probes through the openings in the at least one guide plate, wherein an end portion of the probes extends from unremoved sacrificial material; (iii) after forming the probes to have only a partial length, positioning the at least one guide plate laterally and longitudinally over and around the end portions of the partial length probes, then completing formation of the length of the probes, wherein at the time of positioning of the at least one guide plate, an end portion of the partially formed probes extends from unremoved sacrificial material; (iv) after forming the probes to have a full length, forming the at least one guide plate with the openings aligned laterally with the probes and positioned longitudinally with the openings at least partially surrounding portions of the probes while other portions of the probes remain covered with unremoved sacrificial material; and (v) after forming the probes to at least partial length, forming at least one guide plate with the openings aligned laterally with the probes but longitudinally above end portions of the probes, and thereafter exposing the end portions of the probes by removing a portion of the sacrificial material, and lowering the at least one guide plate longitudinally over and around the end portions of the probes.
2. The method of claim 1 wherein forming of each multi-material layer comprises:
- (a) depositing at least a first of the at least two materials;
- (b) depositing at least a second of the at least two materials;
- (c) planarizing at least two of the at least two deposited materials, including planarizing at least one structural material and at least one sacrificial material and wherein each successively formed multi-material layer of the plurality of multi-material layers is adhered to a previously formed multi-material layer or a non-multi-material layer that in turn was adhered directly or indirectly to a previously formed multi-material layer.
3. The method of claim 1 wherein the probes with a full length are formed with an end portion extending from unremoved sacrificial material by an amount selected from a group consisting of:
- (a) less than a lateral dimension of an individual probe;
- (b) less than a lateral dimension of a spacing between adjacent probes;
- (c) less than a fraction of a height of a probe where the fraction is selected from a group consisting of (1) ½, (2) ⅓, (3) ¼, (4) ⅕, (5) 1/10, and (6) 1/20;
- (d) less than N thicknesses of the guide plate, wherein N is selected from a group consisting of (1) 4, (2) 3, (3) 2, (4) 1, (5) ½, (6) ⅓, and (7) ¼;
- (e) less than an amount selected from a group consisting of 500 microns, 200 microns, 100 microns, 50, microns, 20 microns, 10 microns, and 5 microns.
4. The method of claim 1 wherein the at least one guide plate is positioned with the openings at least partially surrounding the probes with a full length wherein only a end portion of a longitudinal length of the probes extend from unremoved sacrificial material at the time of guide plate formation, wherein the end portion is selected from a group consisting of:
- (a) less than a lateral dimension of an individual probe;
- (b) less than a lateral dimension of a closest spacing between adjacent probes;
- (c) less than a fraction of a height of a probe where the fraction is selected from a group consisting of (1) ½, (2) ⅓, (3) ¼, (4) ⅕, (5) 1/10, and (6) 1/20;
- (d) less than N thicknesses of the guide plate, wherein N is selected from a group consisting of (1) 4, (2) 3, (3) 2, (4) 1, (5) ½, (6) ⅓, and (7) ¼;
- (e) less than an amount selected from a group consisting of (1) 500 microns, (2) 200 microns (3) 100 microns, (4) 50, microns, (5) 20 microns, (6) 10 microns, and (7) 5 microns.
5. The method of claim 1 wherein the probes formed to at least partial length have an end portion extending from unremoved sacrificial material by an amount selected from a group consisting of:
- (a) less than a lateral dimension of an individual probe;
- (b) less than a lateral dimension of a spacing between adjacent probes;
- (c) less than a fraction of a height of a probe where the fraction is selected from a group consisting of (1) ½, (2) ⅓, (3) ¼, (4) ⅕, (5) 1/10, and (6) 1/20;
- (d) less than N thicknesses of the guide plate, wherein N is selected from a group consisting of (1) 4, (2) 3, (3) 2, (4) 1, (5) ½, (6) ⅓, and (7) ¼;
- (e) less than an amount selected from a group consisting of (1) 500 microns, (2) 200 microns (3) 100 microns, (4) 50, microns, (5) 20 microns, (6) 10 microns, and (7) 5 microns.
6. The method of claim 1, further comprising, after separating the probes from unremoved sacrificial material:
- relative lateral shifting of the at least one guide plate with respect to the substrate to provide the probes with a desired placement, shape, and/or configuration due to lateral offsetting.
7. The method of claim 1, further comprising, before separating the probes from unremoved sacrificial material:
- remove the substrate and a portion of the sacrificial material exposing further end portions of the probes; and
- positioning a further guide plate with further openings at least partially surrounding the further end portions of the probes extending from unremoved sacrificial material.
8. The method of claim 7, further comprising, after separating the probes from unremoved sacrificial material:
- relative lateral shifting of the at least one guide plate with respect to the further guide plate to provide the probes with a desired placement, shape, and/or configuration due to lateral offsetting.
9. The method of claim 1, wherein forming the at least one guide plate over the substrate prior to forming a first layer of the plurality of multi-material layers of the probes comprises:
- forming a masking material with openings at the desired probe locations for the probes with a required probe-to-probe spacing;
- positioning the at least one guide plate with openings coated by a coating material aligned with the openings of masking material;
- forming a patterned masking material over the at least one guide plate; and
- depositing structural material into the openings of the masking materials and of the at least one guide plate to partially form the probes.
10. The method of claim 9, further comprising:
- after partial formation of the probes, removing the masking material and exposing respective end portions of the probes;
- depositing a sacrificial material to surround the respective end portions and fill in at least part of the gaps around the probes and the at least one guide plate; and
- planarizing the sacrificial material and the structural material forming the probes to set a planar surface for a subsequent layer formation.
11. The method of claim 10, further comprising:
- after planarizing the sacrificial material and the structural material forming the probes, forming additional layers on the planar surface, each additional layer comprising the structural material forming the probes and the sacrificial material;
- forming a last layer of masking material;
- removing the masking material to expose further end portions of the probes; and
- positioning a further guide plate with further openings at least partially surrounding the exposed further end portions of the probes.
12. The method of claim 11, further comprising, after positioning the further guide plate and before separating the probes from unremoved sacrificial material:
- forming one or more additional probe layers which include structural material and sacrificial material to complete the probes.
13. The method of claim 11, further comprising, after separating the probes from unremoved sacrificial material:
- relative lateral shifting of the at least one guide plate with respect to the further guide plate to provide the probes with a desired placement, shape, and/or configuration due to lateral offsetting.
14. The method of claim 11, further comprising, before positioning the further guide plate:
- coating the exposed further end portions of the probes with a coating material to provide a spacing between the probes and side walls of the openings of the further guide plate.
15. The method of claim 1, wherein the probe array is a two-dimensional probe array.
Type: Application
Filed: Sep 18, 2023
Publication Date: Jan 18, 2024
Inventors: MIchael S. Lockard (Lake Elizabeth, CA), Stefano Felici (San Jose, CA), Uri Frodis (Los Angeles, CA), Dennis R. Smalley (Newhall, CA)
Application Number: 18/469,046
