WO2023196438A1 - Probes with planar unbiased spring elements for electronic component contact, methods for making such probes, and methods for using such probes - Google Patents

Abstract

Probe for making contact between two electronic circuit elements comprises a feature selected from the group consisting of: (A) at least one first tip (3531-UA) and second tip arm (3531-LA) supporting a shunting element (3571-U, 3571-L) that makes an electrical connection to at least one standoff while shunting current flow away from a spring element (3521-U, 3571-L) of the probe that joins a respective standoff and supports the respective tip arm, and (B) both of the first tip arm and the second tip arm support a respective shunting element that makes an electrical connection to the at least one respective standoff while shunting current flow away from a respective spring element that joins the respective standoff and supports the respective tip arm.

Description

PROBES WITH PLANAR UNBIASED SPRING ELEMENTS FOR ELECTRONIC COMPONENT CONTACT, METHODS FOR MAKING SUCH PROBES, AND METHODS FOR USING SUCH PROBES

RELATED APPLICATIONS

[0001] The Present Application claims priority to and the benefit of the filing dates of U.S. Pat. App. Ser. No. 18/295,748, filed April 4, 2023, and Prov. U.S. Pat. App. Ser. No. 63/328,677, filed Apr. 7, 2022, the entire disclosures of which applications are all hereby incorporated herein by reference.

FIELD OF THE INVENTION

[0002] Embodiments of the present invention relate to microprobes (e.g., for use in the wafer level testing or socket testing of integrated circuits, or for use in making electrical connections to PCBs or other electronic components) and more particularly to pin-like microprobes (i.e., microprobes that have vertical or longitudinal heights that are greater than their widths (e.g. greater by a factor of 5 in some embodiments, a factor of 10 in others and a factor of 20 in still others)) or button-like probes wherein spring elements have planar configurations when in an unbiased state. In some embodiments, the microprobes are produced, at least in part, by electrochemical fabrication method s and more particularly by multi-layer, multi-material electrochemical fabrication methods, and wherein, in some embodiments, a plurality of probes are put to use while held in array formations including one or more plates with through holes that engage features of the probes and/or other array retention structures.

BACKGROUND OF THE INVENTION

Probes:

[0003] Numerous electrical contact probe and pin configurations have been commercially used or proposed, some of which may qualify as prior art and others of which do not qualify as prior art. Examples of such pins, probes, and methods of making are set forth, for instance, in the patent publications Nos. US 2005-0104609, US 2006-0006888, US 2005-0184748, US 2006- 0108678, US 2006-0238209 and patentsNos. US 7,640,651, US 7,265,565, US 7,412,767, US 7,273,812, US 10,215,775, US 11,262,383.

Electrochemical Fabrication:

[0004] Electrochemical fabrication techniques for forming three-dimensional structures from a plurality of adhered layers have been, or are being, commercially pursued by Microfabrica® Inc. (formerly MEMGen Corporation) of VanNuys, California under the process names EFAB and MICA FREEFORM®.

[0005] Various electrochemical fabrication techniques were described in U.S. Patent No. 6,027,630, issued on February 22, 2000, to Adam Cohen.

[0006] Another method for forming microstructures using electrochemical fabrication techniques was taught in U.S. Patent No. 5, 190,637 to Henry Guckel, entitled “Formation of Microstructures by Multiple Level Deep X-ray Lithography with Sacrificial Metal Layers”.

[0007] 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.

[0008] A need exists in various fields for miniature devices having improved characteristics, 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.

SUMMARY OF THE INVENTION

[0009] It is an object of some embodiments of the invention to provide improved probe array comprising probes that include compliant elements formed from a plurality of compliant modules that include planar but non-linear (i.e., not straight) spring configurations (i.e. the spring configurations are not straight bars without bends or angles but have some two-dimensional configuration within the plane of at least one layer that provides bends or curves), when unbiased, where the planes of the springs are perpendicular to a longitudinal axis of the probes and provide for compliance along the longitudinal axis of the probes wherein the compliant modules are stacked in a serial manner. The probes with non-linear spring configurations may provide linear spring return forces or non-linear return forces upon biasing.

[0010] In a further aspect of the invention, a probe array includes: (1) a plurality of probes for making contact between two electronic circuit elements, with each probe including: (a) at least one compliant structure, including: (i) at least one relatively rigid standoff having a first end and a second end that are longitudinally separated; (ii) at least one first compliant element including a two-dimensional substantially planar spring when not biased, wherein the first compliant element provides compliance in a direction substantially perpendicular to the planar configuration, wherein a first portion of the first compliant element functionally joins the at least one standoff and a second portion of the first compliant element functionally joins a first tip arm that can compliantly move relative to the standoff, wherein the first tip arm directly or indirectly holds a first tip end that extends longitudinally beyond the first end of the at least one standoff when the first compliant element is not biased; and (iii) at least one second compliant element including a spring, wherein the second compliant element provides compliance in a direction substantially perpendicular to the planar configuration, wherein a first portion of the second compliant element functionally joins the at least one standoff and a second portion of the second compliant element functionally joins a second tip arm that can compliantly move relative to the standoff, wherein the second tip arm directly or indirectly holds a second tip end that extends longitudinally beyond the end of the second end of the at least one standoff when the second compliant element is not biased, wherein the first portions of the first and second compliant elements are longitudinally spaced from one another and wherein upon biasing of at least one of the first and second tip ends toward the other, the second portions of the first and second compliant elements move longitudinally in a manner selected from the group consisting of (A) moving closer together, and (B) further apart; wherein the probe includes a feature selected from the group consisting of: (A) at least one of the first tip and the second tip arm supports a shunting element that makes an electrical connection to the at least one standoff while shunting current flow away from the compliant element that joins a respective standoff and supports the respective tip arm wherein the level of current shunting is selected from the group consisting of: (1) at least 50%, (2) at least 70%, (3) at least 80%, (4) at least 90%, (5) at least 95%, and (6) at least 99%; and (B) both of the first tip arm and the second tip arm support a respective shunting element that makes an electrical connection to the at least one respective standoff while shunting current flow away from the respective compliant element that joins a respective standoff and supports the respective tip arm, wherein the level of current shunting away from each respective spring element is selected from the group consisting of: (1) at least 50%, (2) at least 70%, (3) at least 80%, (4) at least 90%, (5) at least 95%, and (6) at least 99%.

[0011] Numerous variations of the above indicated aspect of the invention exist and will be apparent to those of skill in the art upon review of the teachings herein.

[0012] Other aspects of the invention will be understood by those of skill in the art upon review of the teachings herein. Other aspects of the invention may involve combinations of the above noted aspects. These other aspects of the invention may provide various combinations of the aspects presented above as well as provide other configurations, structures, functional relationships, and processes that have not been specifically set forth above but are taught by other specific teachings set forth herein, by the teachings of the specification as a whole, or by teachings incorporated herein by reference. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIGS. 1A - IF schematically depict the formation of a first layer of a structure using adhered mask plating where the blanket deposition of a second material overlays both the openings between deposition locations of a first material and the first material itself.

[0014] FIG. 1G depicts the completion of formation of the first layer resulting from planarizing the deposited materials to a desired level.

[0015] FIGS. 1H and II respectively depict the state of the process after formation of the multiple layers of the structure and after release of the structure from the sacrificial material. [0016] FIG. 2 depicts an isometric view of an example spring module or compliant module having two connected spring elements, a base, and a connecting support or standoff that may be used in a probe or as a probe.

[0017] FIG. 3 depicts an isometric view of a second example spring module or compliant module that may be used in a probe, or as a probe, similar to the module of FIG. 2 with the exception that the two spring elements are thicker and, as such, provide a greater spring constant than that of the elements of FIG. 2.

[0018] FIGS. 4A - 4D4 provide various views of a probe according to another embodiment of the invention where the probe is formed from two back-to-back modules and the two modules share a common base that also functions as a standoff and has an annular configuration.

[0019] FIG. 4E1 provides a side view of the probe of FIGS. 4A - 4D4 showing 17 sample layer levels from which the probe can be fabricated wherein not all layers have unique configurations.

[0020] FIGS. 4E2-A to 4E9-B illustrate cross-sectional configurations shown in both a top view (the -A figures) and in an isometric view (the -B figures) for unique configurations of layers LI - L17 with FIGS. 4E2-A and 4E2-B illustrating views of layers LI and LI 7; FIGS. 4E3-A and 4E3-B illustrating views of layers L2, L4, L6, and L8; FIGS. 4E4-A and 4E4-B illustrating views of layers L3 and L7; FIGS. 4E5-A and 4E5-B illustrating views of layer L5; FIGS. 4E6-A and 4E6-B illustrating views of layer L9; FIGS. 4E7-A and 4E7-B illustrating views of layers L10, LI 2, LI 4, and LI 6; FIGS. 4E8-A and 4E8-B illustrating views of layers LI 1 and LI 5; and FIGS. 4E9-A and 4E9-B illustrating views of layer L13.

[0021] FIGS. 5A1 - 5A5 provide a side view (FIG. 5 A3), two full probe isometric views (FIGS. 5 Al and 5A2) and two sectioned isometric views (FIG. 5A4 and 5A5) all from the same rotational orientation about the Z-axis or longitudinal axis of an example probe wherein the probe has similarities to the probe of the FIG. 4 series with the primary exceptions that the central base of the probe of the FIG. 4 series is removed and upper and lower shunting bars are provided so that current can be shunted away from the compliant elements into the standoffs or spring module support structures.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Electrochemical Fabrication in General

[0022] FIGS. 1A - II illustrate side views of various states in an example multi-layer, multimaterial electrochemical fabrication process. FIGS. 1A - 1G illustrate various stages in the formation of a single layer of a multi-layer fabrication process where a second metal is deposited on a first metal as well as in openings in the first metal so that the first and second metal form part of the layer. In FIG. 1A, a side view of a substrate 82 having a surface 88 is shown, onto which pattemable photoresist 84 is located as shown in FIG. IB. In FIG. 1C, a pattern of resist is shown that results from the curing, exposing, and developing of the resist. The patterning of the photoresist 84 results in openings or apertures 92(a) - 92(c) extending from a surface 86 of the photoresist through the thickness of the photoresist to surface 88 of the substrate 82. In FIG. ID, a metal 94 (e.g., nickel) is shown as having been electroplated into the openings 92(a) - 92(c). In FIG. IE, the photoresist has been removed (i.e., chemically or otherwise stripped) from the substrate to expose regions of the substrate 82 which are not covered with the first metal 94. In FIG. IF, a second metal 96 (e.g., silver) is shown as having been blanket electroplated over the entire exposed portions of the substrate 82 (which is conductive) and over the first metal 94 (which is also conductive). FIG. 1G depicts the completed first layer of the structure which has resulted from the planarization of the first and second metals down to a height that exposes the first metal and sets a thickness for the first layer. In FIG. 1H, the result of repeating the process steps shown in FIGS. IB - 1G several times to form a multi-layer structure is shown where each layer consists of two materials. For most applications, one of these materials is removed, as shown in FIG. II, to yield a desired 3-D structure 98 (e.g., component or device) or multiple such structures.

[0023] 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 example of FIGS. 1A - II and as discussed in various patent applications incorporated herein by reference). Some of these structures may be formed from a single build level formed from one or more deposited materials while others are formed from a plurality of build layers, each including at least two materials (e.g., two or more layers, more preferably five or more layers, and most preferably ten or more layers). In some embodiments, layer thicknesses may be as small as one micron or as large as fifty microns. In other embodiments, thinner layers may be used while in other embodiments, thicker layers may be used. In some embodiments, microscale structures have lateral features positioned with 0.1 - 10-micron level precision and minimum feature sizes on the order of microns to tens of microns. In other embodiments, structures with less precise feature placement and/or larger minimum features may be formed. In still other embodiments, higher precision and smaller minimum feature sizes may be desirable. In the present application, meso-scale and millimeter-scale have the same meaning and refer to devices that may have one or more dimensions that may extend into the 0.5 - 50-millimeter range, or larger, and features positioned with a precision in the micron to 100 micron range and with minimum feature sizes on the order of tens of microns to hundreds of microns.

[0024] 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), nonconformable masks and masking operations (i.e. masks and operations based on masks whose contact surfaces are not significantly conformable), and/or 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).

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 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, and/or (3) direct formation of masks from computer-controlled depositions of material. In some embodiments, adhered mask material may be used as a sacrificial for the layer or may be used only as a masking material which is replaced by another material (e.g., dielectric or conductive material) prior to completing formation of a layer where the replacement material will be considered the sacrificial material of the respective layer. Masking material may or may not be planarized before or after deposition of material into voids or openings included therein.

[0025] 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 No. 10/434,519, by Smalley, filed May 7, 2003, which is now US Patent 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.

[0026] 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) or 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., by 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.

[0027] 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 (e.g., US Patent Application No. 16/584,818).

[0028] “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, or probes as they will be loaded into an array configuration, the longitudinal dimension may refer to a particular direction that 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 first ends, tips, or bases of a plurality of probes and extends perpendicular thereto to a plane containing second ends, tips, or tops 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.

[0029] “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 is substantially perpendicular to a layer stacking 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.

[0030] “Substantially parallel” as used herein means something that is parallel or close to being parallel, i.e., within 15° of being parallel, more preferably within 10° of being parallel, even more preferably within 5° of being parallel, and most preferably within 1° of being parallel. If the term is used without clarification, it should be interpreted as being within 15° of being parallel. When used with specific clarification, the term should be construed in accordance with the specific clarification.

[0031] “Substantially perpendicular” or “substantially normal” as used herein means something that is perpendicular or close to being perpendicular, i.e., within 15° of being perpendicular, more preferably within 10° of being perpendicular, even more preferably within 5° of being perpendicular, and most preferably within 1° of being perpendicular. If the term is used without clarification, it should be interpreted as being within 15° of being perpendicular. When used with specific clarification, the term should be construed in accordance with the specific clarification.

[0032] “Substantially planar” when referring to a surface, as used herein, refers to a surface that is intended to be planar, though some imperfections may exist as will be understood by one of skill in the art (i.e. imperfections that may deviate from planarity by up to 1 - 5 microns but often are submicron in nature when referring to millimeter and micro-scale devices as are the primary device embodiments set forth herein). If the term is used without clarification, it should be interpreted as having imperfections that deviate from planarity by no more than 5 microns. When used with specific clarification, the term should be construed in accordance with the specific clarification. When referring to a structure, the term does not refer to a structure that is infinitely thin but one that is formed with top and bottom surfaces that are substantially planar, for example, the top and bottom surface of each layer, or group of successively formed layers of a structure formed using multi-material, multi-layer electrochemical fabrication methods particularly when each layer undergoes a planarization operation such as lapping, fly cutting, chemical mechanical planarization, spreading by spinning, and the like. A substantially planar structure, in some cases, may also imply that the structure, or element of the structure, is small in height or thickness compared to a size of the structure in the two perpendicular dimensions (i.e. the ratio of perpendicular foot print to thickness is greater than 25, preferably greater than 50, more preferably greater than 100, and most preferably greater than 200). If the term is used with regard to a structure without clarification, it should be interpreted as meeting the substantially planar surface criteria for both upper and lower surfaces. In some contexts, a ratio requirement may also apply, i.e., a ratio of at least 25. When used with regard to a structure with specific clarification, the term should be construed in accordance with the specific clarification.

[0033] “Relatively rigid” as used herein refers to a comparison of rigidity between two structural elements when the two structural elements are subject to working loads or stresses where the relatively rigid structural element should undergo less deflection or distortion compared to the other structural element by at least a factor of 2, more preferably by a factor of 5, and most preferably by a factor of 10. If the term is used with regard to a structural element without clarification, it should be interpreted as meeting the factor of 2 requirement. When used with regard to a structural element with specific clarification, the term should be construed in accordance with the specific clarification.

[0034] “Non-linear configuration” as used herein refers to a configuration that is not a straight bar-like configuration particularly when applied to a physical structure or element. A non-linear configuration would be a configuration that is two or three dimensional in nature with features that include one or more bends or curves. For example, a planar, non-linear structure may be a flat spiral structure. When referring to springs, as used herein, a non-linear configuration does not refer to a force-deflection relationship unless specifically and unambiguous indicating such a relationship.

Probes with Planar Spring Modules:

[0035] Planar springs or planar compliant elements of the present invention may be formed in a number of different ways and take a number of different configurations. Generally, the compliant elements include planar springs that have portions that extend from a standoff to a tip or tip arm in a cantilever or bridged manner (e.g., two or more springs starting from different lateral standoff locations and joining to a common tip arm - herein generally referred to as a cantilever or cantilevers) over a gap or open area into which the spring may deflect during normal operation. These compliant portions generally have two-dimensional non-linear configurations within a lateral plane and a thickness extending perpendicular to the plane (e.g., in longitudinal direction), where two-dimensional configuration may be in the form of a beam structure with a curved or angled configuration with a length much larger than its width, e.g. at least 5, 10, 20, or even 50 times or more in some variations, wherein the thickness is generally smaller than the length of the beam, e.g. at least 5, 10, 20, or even 50 times or more in some variations, or a lateral dimension of the spring element, e.g. 2, 5, 10, or even 20 times or more in some variations. In some embodiments, the plane of such configurations may be parallel to layer planes when the probes or modules are formed from a plurality of adhered layers (e.g., X-Y plane). The thickness (e.g., in a Z-direction) of a spring may be that of a single layer or may be multiple layer thicknesses. In some embodiments, compliant elements include a plurality of spaced planar spring elements.

[0036] In some embodiments the compliant elements may include planar spring elements that are joined not only at a standoff or tip structure to one another but also at locations intermediate to such end elements. In some such embodiments, the planar spring elements may start from one end (e.g., a standoff or tip arm) as one or more thickened springs with a relatively high spring constant and then be provided with a reduced spring constant by removal of some intermediate spring material between the top and bottom of the initial spring structure such that what started as a small but thick number of planar compliant elements (e.g. 1, 2, or 3 elements) transitions to a larger number of thinner planar elements, with some initial planar elements dividing into 2, 3, 4, 5 or more planar but thinner elements, prior to reaching the other end (e.g. a tip arm of standoff) whereby, for example, the spring constant, force requirements, overtravel, stress, strain, current carrying capacity, overall size and other operational parameters can be tailored to meet requirements of a given application.

[0037] Reference numbers are included in many of FIGS. 2 to 5E2 wherein like numbers are used to represent similar structures or features in the different embodiments.

[0038] Example spring modules are shown in FIGS. 2 - 3. FIG. 2 depicts an isometric view of an example spring module 200 with two undeflected spring elements 221-1 and 221-2, a base 201 spaced from the spring elements and a connecting support (e.g., a standoff orbridge) 211 that bridges a longitudinal module gap MG between the spring elements and the base. In the example of FIG. 2, each of the two spring elements take the form of a planar radially extending spiral that extends from the radially displaced bridge 211 to a centrally or axially positioned tip element 231 via a downward extending portion of the tip structure. The springs are separated longitudinally by a gap SG. In this example, the bridge 211 connects one end of each spring element together while a tip element 231 connects the other ends of the spring elements together via an extended portion of the tip structure. The tip element 231 is formed with a desired width TW and desired tip height TH extending above the upper spring, and each spring element is formed with a desired material, beam thickness or spring height SH, beam width or spring width SW, spacing between spring coils CS, and coiled beam length that allows the spring to deflect a desired amount without exceeding an elastic deflection limit of the structure and associated material from which it is formed while providing a desired fixed or variable spring force over its deflection range. In particular, the length of the tip may be such that a desired compression of a module tip toward the base can occur without the base, bridge, and spring elements interfering with one another. In some embodiments, for example, a maximum travel distance for the tip of each module may be as little as 5 um (um = micron) or less or as much as 500 um (e.g., 25 urns, 50 urns, 100 urns or 200 urns) or more. For example, in some embodiments, a maximum travel distance per module may be 25 um to 200 um while in other example embodiments, the maximum travel distance per module may be 50 um to 150 um. In some embodiments, the maximum travel distance of the tip may be set by a hard stop such as by the deflected portion of the spring or tip coming into contact with the base, by a stop structure on the base, or possibly by a surface that contacts the tip (e.g., the surface of an adjacent module) coming into contact with the upper portion of the bridge. In other embodiments, the maximum travel distance may be instilled by the compliant spring or tip portion coming into contact with a soft stop or compliance decreasing structure. The force to achieve maximum deflection (or travel) may be as small as 0.1 gram force to as large as 20 or more gram force. In some embodiments, a force target of 0.5 grams may be appropriate. In others, 1 gram, 2 grams, 4 grams, 8 grams or more may be appropriate. In some embodiments, a module height MH (longitudinal dimension) of 50 urns or less may be targeted while in others, a module height of 500 urns or more may be targeted. In some embodiments, overall module radial diameter or width MW may be 100 urns or less or 400 urns or more (e.g., 150 urns, 200 urns, or 250 urns). The spring beam element, or beam elements, of a module may have spring heights SH from 1 um, or less, to 100 um, or more (e.g., 10, 20, 30, or 40 um), and beam widths or spring widths SW from 1 um or less to 100 um or more (e.g., 10, 20, 30, or 40 um). Tips may have uniform or changing geometries (e.g., with cylindrical, rectangular, conical, multi-prong, or other configurations, or combinations of configurations). Tips, where joining to spring beams, will generally possess larger cross- sectional widths TW than the widths SW of the beam or beams to which they connect.

[0039] FIG. 3 depicts an isometric view of a second example spring module 300 that is similar to the module of FIG. 2 with the exception that the two spring elements are thicker and, as such, provide a greater spring constant than that of the elements of FIG. 2. From another perspective, the example of FIG. 3 will require more force fora given deflection and, as such, will reach a yield strength (e.g., reach an elastic deflection limit) of the combined material and structural geometry with less deflection than the example of FIG. 2.

[0040] In other embodiments, spring modules may take different forms than those shown in FIG. 2 or FIG. 3. For example: (1) a module may have a single spring element or more than two spring elements; (2) each of the spring elements may have variations in one or more of widths, thicknesses, lengths, or extent of rotations; (3) spring elements may change over the lengths of the elements; (4) spring elements may have configurations other than Euler spirals, e.g. rectangular spirals, rectangular spirals with rounded comers, S-shaped structures, or C-shaped structures; (5) individual spring elements may connect to more than a single bridge junction, e.g. to bridge connection points located at 180 degrees around the module, 120 degrees or 90 degrees; (6) bridge junctions may be located on distinct bridges; (7) base elements may have smaller radial extents than spring/bridge junctions such that bases of higher modules may extend below upper extents of lower adjacent modules upon sufficient compression of module tips when modules are stacked; (8) module bases may be replaced with additional springs that allow compression of module springs from both directions upon deflection, (9) probe tips may not be laterally centered relative to the overall lateral configuration of the module (i.e. not coincident or even co-linear with the primary axis of compression or the primary build axis when formed on a layer-by-layer basis).

[0041] FIGS. 4A - 4D4 provide various views of a probe 3400, or of portions of such a probe, where the probe is formed from two back-to-back (or base-to-base) modules where the two modules share a common base that has an annular configuration and includes a number of distinct features: (1) an annular base or frame 3401 that holds an upper spiral spring array 3421- UC and a lower spiral spring array 3421-LC by their outermost lateral extents to provide basic standoff functionality between the upper and lower spring arrays wherein the base or frame 3401 has a circular exterior with an interior opening that has opposing arcuate sides 3401 -A and narrower opposing flat sides 3401-F wherein upper and lower surfaces joining the flat sides provide attachment regions for joining with upper and lower supports or standoffs 3411-1, 3411- 2, 3412-1, and 3412-2 that in turn support the ends of the spiral spring elements while the arcuate regions provide gaps over which outermost cantilever portions of the springs can reside (prior to deformation), where the thickness of the base acts as a standoff spacer in which portions of the spiral springs can deflect during compression of probe tips toward one another; (2) each of the upper and lower spring arrays start their inward path from opposing pairs of standoffs as two longitudinally separated co-planar pairs of winding spiral cantilevers 3421-1U and 3421-2U above the base and 3421-1L and 3421-2L below the base with each cantilever of each element dividing into two longitudinally spaced cantilevers partway through their inward treks such that four upper cantilever elements UC 1 - UC4 join each side of an upper tip arm 3431-UA while four lower cantilever elements LC 1 - LC4 join either side of a lower tip arm 3431-LA that in turn respectively support contact or bonding tips 3431-U and 3431-L; (3) the rotational orientations of the spiral spring elements joining the upper contact tip have opposite rotational orientations relative to the spiral spring elements joining the lower contact tip; and (4) the standoffs 3411-1, 3411-2, 3412-1, and 3412-2 provide only intermediate standoff functionality between multiple beams of the upper spiral array and between the multiple spiral beams of the lower spiral array but not standoff functionality between the two spring groups as that function is provided directly by the base 3401.

[0042] FIGS. 4A, 4B1, and 4B2, respectively, provide side, upper isometric, and lower isometric views of probe 3400 where different features of the probe can be seen. FIG. 4B 1 provides a view of the uppermost pair of spiral springs of the upper spring section of the probe while FIG. 4B2 provides a view of the lowermost pair of spiral springs of the lower spring section of the probe. Each of FIGS. 4A, 4B 1, and 4B2 provides a view of the upper and lower tips 3431-U and 3431-L along with the central base 3401. FIGS. 4A, 4B 1 and 4B2 also provide views of upper standoffs 3411-1 and 3411-2 as well as lower standoffs 3412-1 and 3412-2, as well as views of the outer portions of the longitudinally separated upper cantilever elements 3421-1U and 3421-2U and lower cantilever elements 3421-1L and 3421-2L. The interleaved paths of the pairs of coplanar cantilever elements can also be seen to propagate inward from their respective standoffs to meet at their respective central tips.

[0043] FIGS. 4C1 and 4C2, respectively, provide exploded isometric views of probe 3400 from upper and lower perspectives so that not only can the bottom of the lower cantilever elements and the top of the upper cantilever elements be seen but also so that the top of the lower cantilever elements and the bottom of the upper cantilever elements can be seen as well as the interior of the annular base 3401 including the flat and arcuate side walls 3401-F and 3401-A. In FIGS. 4C1 and 4C2, the upper spring section or upper compliant element 3421-UC of the probe is separated from the central frame or base element 3401 which is in turn separated from the lower spring section or lower compliant element 3421-LC of the probe. The upper tip 3431- U can be seen in FIG. 4C1 along with the tops of the upper and lower spring sections and the top of the central frame element. The lower tip 3431-L:can be seen in FIG. 4C2 along with the bottoms of the upper and lower spring sections 3421-UC and 3421-LC and the bottom of the central frame element 3401. As can be seen by the dashed lines connecting the exploded elements, the central frame element 3401 supports the outermost lateral extents of the upper and lower spring sections, and more particularly, the standoffs 3411-1, 3411-2, 3412-1, and 3412-2 that support those cantilever elements.

[0044] FIGS. 4D1 - 4D4 provide four different cut views of probe 3400 with progressively larger portions of a side of the probe cut away so as to reveal the interior structure of the probe such that cantilever changes can be more readily seen and understood. As the spiral elements rotate inward toward laterally centered tip elements, the cantilever elements undergo transition from two longitudinally separated cantilever elements 3421-2U and 3421-1U above the base 3401 and two longitudinally separated cantilever elements 3421-1L and 3421-2L below the base 3401 to four longitudinally separated cantilever elements UC1 - UC4 above the base and four longitudinally separated elements LC1 - LC4 below the base where the beams reach their respectively longitudinally moveable tip arm elements 3431-UA and 3431 -LA (best seen in FIG. 4D3) which in turn join or become tips 3431-U and 3431-L respectively.

[0045] FIG. 4E1 provides a side view of the probe 3400 similar to that of FIG. 4A but with 17 sample layer levels LI to L17 identified with each layer having the identified thickness along the longitudinal axis of the probe (i.e. the Z-axis as shown) from which the probe can be fabricated, e.g., via a multi-layer fabrication process such as a multi-layer, multi-material electrochemical fabrication process using a single or multiple structural materials (along with a sacrificial material) and using a build axis or layer stacking axis corresponding to the longitudinal axis of the probe. In such formation embodiments, though probes may be formed one at a time, generally it is preferred to form the probes in batch with hundreds or even thousands of probes formed simultaneously by successive layer-upon-layer build up.

[0046] FIGS. 4E2-A to 4E9-B illustrate cross-sectional configurations shown in both top views (the -A figures) and in isometric views (the -B figures) for the eight unique configurations of layers LI - L17.

[0047] FIGS. 4E2-A and 4E2-B illustrate views of layers LI and L 17 wherein a tip can be seen which is the lower tip 3431-L for LI and the upper tip 3431-U for layer LI 7.

[0048] FIGS. 4E3-A and 4E3-B illustrate views of L2, L4, L6, and L8 which provide portions of planar spring spirals 3421-1L, 3421-2L as well as their innermost regions that form cantilever sections LC1 to LC4 (not labeled), portions of the lower central tip arm 3431 -LA, and portions of the lower standoffs 3412-1 and 3412-2 wherein double, interlaced spiral configurations can be seen.

[0049] FIGS. 4E4-A and 4E4-B illustrate views of L3 and L7 where incomplete spiral elements 3421-1L, 3421-2L and standoffs 3412-1 and 3412-2 (similar to the features of FIGS. 4E3-A and 4E3-B but with the LC1 - LC4 portions missing) can be seen. The spiral portions reflected in these figures, in combination with the overlaying and underlying portions of FIGS. 4E3-A and 4E3-B, form thickened spiral sections in the outer most lateral portions of the springs where the lower compliant element 3421-LC includes only two thickened cantilever elements as opposed to the four thinner cantilever elements LC 1 - LC4 that join the tip arm at the innermost lateral portions of the springs.

[0050] FIGS. 4E5-A and 4E5-B illustrate views of L5 that include a portion of lower tip arm 3431-LA and portions of standoffs 3412-1 and 3412-2 which provide a connection between the 3421-1L and 3421-2L cantilever spring portions.

[0051] FIGS. 4E6-A and 4E6-B illustrate views of L9 which include ring-like base 3401 that separates and connects the upper and lower compliant elements 3421-UC and 3421-LC via two portions of the base that act as standoffs where some lateral portions of the base are aligned with and engage the springs in their standoff regions 3411-1, 3411-2, 3412-1 and 3412-2. The actual beginning of the inward rotating spirals of probe 3400 depend on how the features of L8 interface with those of L9 and likewise how the features of L9 interface with those of L10. In particular, the interfaces are not perpendicular to local length of the winding spiral (e.g. such that a minimum width interface is provided) but are formed at an angle such that an outer portion of the spiral beam(s) that interface with the base are supported along their lengths by a different amount than are the inner portions. In some variations, interfaces may be provided in a manner such that the interface is provided perpendicular to the local length of the beam such that support provided by the base (or other standoff regions) provide laterally perpendicular or substantially perpendicular transitions between supported and unsupported beam regions. In particular, perpendicular transitions are provided in other beams to stand off regions as can be seen in the interfaces formed by L4 and L5, L5 and L6, L12 and L13, and L13 and L14 and in other beam splitting regions such as L2 to L3, L3 to L4, L6 to L7, L7 to L8, L10 to Li l, Li l to LI 2, L14 to L15 and L15 to L16 where the beams transition extends along a lateral line that is substantially perpendicular to immediate or local length of the beam. Such perpendicular interfacing and non-perpendicular interfacing and their consistent or varying usage may be used in tailoring the probe performance or operational properties. In particular, due to the non-perpendicular interfacing with the base and due to interfacing provided by and between other beams of the cantilever, the outer portions of the cantilevers are provided as a single thick beam while the inner portion of the cantilever structure begins as two beams of intermediate thickness with the endings of the cantilevers at the probe arm as four thinner beams. In some variations, the initial cantilever structures (as they laterally depart from the base) may start as single thick beams or multiple beams throughout their widths. Other transitions along the beam length may also be set to provide clean or perpendicular transitions or may be set to provide variable or non- perpendicular transitions. FIGS. 4E7-A and 4E7-B illustrate views of LIO, L12, L14, and L16 which provide (1) portions of upper planar spring spirals 3421-1U and 3421-2U as well as their innermost extensions that form cantilever portions UC1 toUC4 (not labeled), (2) portions of the upper central tip arm 3431-UA, and portions of the upper standoffs 3411-1 and 3411-2 wherein double, interlaced spiral configurations can be seen. These are upper compliant element counterparts to the lower compliant element features shown in FIGS. 4E3-A and 4E3-B. A comparison of these figures shows that the rotational orientation of the spirals of the upper and lower compliant elements have reversed rotational orientations. This reversal of orientations may be considered beneficial in some cases and unnecessary or even detrimental in others. Upon compression of the spring elements, the tips may tend to rotate in a direction opposite the inward rotation of the spiral elements which may cause a scrubbing or scraping effect which may help break through oxide coating or cause damage to surfaces that are contacted. Reversal of scrubbing orientation between lower and upper probe tips may or may not be desirable and thus may be taken into consideration during initial probe design. Similarly, reversal of relative orientation of the separated upper spring elements is possible and as is the reversal of orientation of the separated lower spring elements.

[0052] FIGS. 4E8-A and 4E8-B illustrate views of layers Li l and L15 where incomplete spiral elements 3421-1U and 3421-2U as well as connecting regions of standoffs 3411-1 and 3411-2 can be seen that bridge portions of the spirals of FIGS. 4E7-A and 4E7-B to form thickened spiral sections in the outer most lateral portions of the springs where the upper compliant element 3421-UC includes only two thickened elements as opposed to the four thinner elements that join the tip arm 3431-UA at the innermost lateral regions of the spirals. FIGS. 4E8- A and 4E8-B provide upper compliant element counterparts to the lower compliant elements shown in FIGS. 4E4-A and 4E4-B.

[0053] FIGS. 4E9-A and 4E9-B illustrate views of layer L13 that includes a portion of upper tip arm 3431-UA and portions of standoffs 3411-1 and 3411-2 which provide a connection between the cantilevers 3421-1U and 3421-2U. FIGS. 4E9-A and 4E9-B provide images of portions of upper compliant elements that are counterparts to lower compliant element counterparts found in FIGS. 4E5-A and 4E5-B.

[0054] Numerous additional variations of the probe of FIGS. 4A - 4E9-B are possible and will be apparent to those of skill in the art upon review of the teachings herein and include, for example: (1) variations in materials; (2) variations in configurations including the number of rotations or partial rotation that each spring element incorporates, the number of interleaved springs that are used at each longitudinal level, the number of longitudinally spaced springs that are used (e.g. even numbers, odd numbers, and the like), the numbers of, and locations of, longitudinal beam transitions that occur along the length of the spirals, the direction of rotation that successive spirals take (e.g. CW-CCW-CW-CCW-CW, CW-CCW-CCW-CCW-CW, and the like), the shapes of the tip, the width and thickness of the cantilever beams; (3) the use of standoffs that space one or both of the upper and lower spring modules from the annular frame, (4) the use of standoffs that are closer to the central portion of the probes as opposed to the outer perimeter of the probes; (5) the use of different types of frame or base structures and/or opening in such frame and base structures; (6) use of spring structures that are not pairs of coplanar interlaced spirals supported by different standoffs but are single spirals on a given longitudinal level or more than two interlaced spirals on a given longitudinal level and (7) variations taken from features of other embodiments and aspects set forth herein and from their variations.

[0055] FIGS. 5A1 - 5A5 provide a side view (FIG. 5 A3), two full probe isometric views (FIGS. 5 Al and 5A2) and two sectioned isometric views (FIG. 5A4 and 5A5) all from the same rotational orientation about the Z-axis or longitudinal axis of an example probe 3500 wherein the probe has similarities to the probe of the FIG. 4 series with the primary exceptions that the central base ring of the probe of the FIG. 4 series is removed and upper and lower shunting bars 3571-U, 3571-L are provided on upper tip arm 3531-UA and lower tip arm 3531 -LA so that current can follow a flow path from an upper tip 3531-U to the upper shunt bar 3571-U through standoffs 3510 via contact region 3570 to the lower shunt bar 3571-L via contact region 3570 to the lower tip 3531-L, or vice versa upon sufficient compression of the probe tips toward one another.

[0056] The probe 3500 has an upper compliant element 3521-U and lower compliant element 3521-L being spring assemblies connected to respective upper probe arm 3531-UA ending with an upper probe tip 3531-U and lower probe arm 3531-L A ending with a lower probe tip 3531- L.

[0057] More particularly, the first compliant element 3521-U provides compliance in a direction substantially perpendicular to a planar configuration, wherein a first portion of the first compliant element functionally joins the at least one standoff and a second portion of the first compliant element functionally joins a first tip arm or upper probe arm 3531-UA ending with the first tip or upper probe tip 3531-U that can elastically move relative to the at least one standoff, wherein the first tip arm 3531-U A directly or indirectly holds the first tip end that extends longitudinally beyond the first end of the at least one standoff when the first compliant element 3521-U is not biased.

[0058] Moreover, the second compliant element 3521-L provides compliance in a direction substantially perpendicular to the planar configuration, wherein a first portion of the second compliant element functionally joins the at least one standoff and a second portion of the second compliant element functionally joins a second tip arm or lower probe arm 3531-LA ending with the second tip or lower probe tip 3531-L that can elastically move relative to the at least one standoff, wherein the second tip arm 3531-LA directly or indirectly holds the second tip end that extends longitudinally beyond the second end of the at least one standoff when the second compliant element 3521-L is not biased.

[0059] According to an embodiment, the first compliant element 3521-U comprises a two- dimensional substantially planar spring when not biased, so that the first compliant element provides compliance in a direction substantially perpendicular to the planar configuration and the second compliant element 3521-L comprises a spring.

[0060] Alternatively, both the first compliant element 3521-U and the second compliant element 3521-L comprise respective two-dimensional substantially planar springs.

[0061] Numerous alternatives to the embodiment of FIGS. 5 Al - 5D3 are possible, and include, for example: (1) using shunt bars to shunt away from only one of the spring modules (e.g. shunting current away one of the upper module and lower module but not both), (2) configuring the shunt bars to contact the standoff on only one side of the probe, (3) configuring the shunt bars to make contact initially with a standoff on only one side of the probe and eventually upon further compression to contact both sides, (4) instead of making contact directly with the standoff, the shunts could be made to make contact with a connection ring or other bridge element located around the upper or lower periphery of the bridge joining one or more standoffs, (5) providing more than two contact locations for shunting either for simultaneous or successively increasing contact upon increased compression, (6) the shunting arms may be configured to provide contact over all or a large fraction of an entire working tip-to-tip compression range of the probe while providing a tailored impact on probe compressibility or probe compression force requirements, (7) in some embodiments, a longitudinal face-to-face contact may be replaced or supplemented with a sliding contact that moves up and down along an edge of a standoff as a probe tip and tip arm undergo more or less compression while always maintaining an electrical connection within a functional range of movement, (8) such sliding contact may be enhanced by use of an offset tip (i.e. not centrally located) or one sided face-to- face contact that favors a tilting of the tip arm and thus the shunt that can force sliding contact, and (9) in other variations, the tip arm or another portion of a spring module may include dielectric elements for inhibiting flow of current through the spring element.

[0062] Still other variations to the probe of FIGS. 5A1 to 5D3 are possible and may be directed to features of the probe other than to the shunting configuration as noted above. One such variation may include the use of a base ring or other stand off-to-standoff bridging elements while still other variations may include features of the other probes set forth herein or alternatives noted in their variations.

Further Comments and Conclusions:

[0063] Numerous embodiments have been presented above, but many additional embodiments are possible without deviating from the spirit of the invention. Some of these additional embodiments may be based on a combination of the teachings herein with various teachings incorporated herein by reference. Some fabrication embodiments may use multi-layer electrochemical deposition processes while others may not. Some embodiments may use a combination of selective deposition and blanket deposition processes while others may use neither, while still others may use a combination of different processes. For example, some embodiments may not use any blanket deposition process and/or they may not use a planarization process in the formation of successive layers. Some embodiments may use selective deposition processes or blanket deposition processes on some layers that are not electrodeposition processes. Some embodiments, for example, may use nickel (Ni), nickel-phosphorous (Ni-P), nickel-cobalt (NiCo), gold (Au), copper (Cu), tin (Sn), silver (Ag), zinc (Zn), solder, rhodium (Rh), rhenium (Re), beryllium copper (BeCu), tungsten (W), rhenium tungsten (ReW), aluminum copper (AICu), palladium (Pd), palladium cobalt (PdCo), platinum (Pt), molybdenum (Mo), manganese (Mn), steel, P7 alloy, brass, chromium (Cr), chrome, chromium copper (CrCu), other palladium alloys, copper-silver alloys, as structural materials or sacrificial materials while other embodiments may use different materials. Some of the above materials may, for example, be preferentially used fortheir spring properties while others may be used for their enhanced conductivity, for their wear resistance, for their barrier properties, for their thermal properties (e.g. yield strength at high temperature or high thermal conductivity), while some may be chosen for their bonding characteristics, for their separability from other materials, and even chosen for other characteristics of interest in a desired application or usage. Other embodiments may use different materials or different combinations of materials including dielectrics (e.g. ceramics, plastics, photoresist, polyimide, glass, ceramics, or other polymers), other metals, semiconductors, and the like as structural materials, sacrificial materials, or patterning materials. Some embodiments, for example, may use copper, tin, zinc, solder, photoresist 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 form probe structures while other embodiments may use the spring modules of the present invention for non-probing purposes (e.g. to bias other operational devices with a desired spring force or compliant engagement).

[0064] 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.

[0065] 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 application functional and do not otherwise contradict or remove all benefits of the adopted embodiment.

[0066] 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 added as dependent claims to further define an invention being claimed by those respective dependent claims should they be written.

[0067] 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

CLAIMS What is claimed is:

1. A probe for making contact between two electronic circuit elements, comprising:

(a) at least one standoff having a first end and a second end that are longitudinally separated;

(b) at least one first compliant element (3521-U) comprising a spring element which provides compliance in a direction substantially perpendicular to a planar configuration, wherein a first portion of the first compliant element (3521-U) functionally joins the at least one standoff and a second portion of the first compliant element functionally joins a first probe arm (3531-

U A) that can elastically move relative to the at least one standoff, wherein the first probe arm (3531-UA) directly or indirectly holds a first tip end (3531-U) that extends longitudinally beyond the first tip end (3531-U) of the at least one standoff when the first compliant element (3521-U) is not biased; and

(c) at least one second compliant element (3521-L) comprising a spring element which provides compliance in a direction substantially perpendicular to the planar configuration, wherein a first portion of the second compliant element (3521-L) functionally joins the at least one standoff and a second portion of the second compliant element (3521-L) functionally joins a second probe arm (3531 -LA) that can elastically move relative to the standoff, wherein the second probe arm (3531-LA) directly or indirectly holds a second tip end (3531-L) that extends longitudinally beyond the second end of the at least one standoff when the second compliant element (3521-L) is not biased, wherein the first portions of the first and second compliant elements (3521-U, 3521-L) are longitudinally spaced from one another and wherein upon biasing of at least one of the first and second tip ends (3531-U, 3531-L) toward the other, the second portions of the first and second compliant elements (3521-U, 3521-L) move longitudinally in a manner selected from the group consisting of; (A) moving closer together, and (B) further apart; wherein the probe comprises a feature selected from the group consisting of: (A) at least one of the first probe arm (3531-UA) and the second probe arm (3531-LA) supports a shunting element (3571-U, 3571-L) that makes an electrical connection to the at least one standoff while shunting current flow away from a spring element that joins a respective standoff and supports the respective probe arm (3531-UA, 3531-LA), and (B) both of the first probe arm (3531-UA) and the second probe arm (3531-LA) support a respective shunting element (3571-U, 3571-L) that makes an electrical connection to the at least one respective standoff while shunting current flow away from a respective spring element that joins the respective standoff and supports the respective probe arm (3531-UA, 3531-LA).

2. The probe of claim 1, wherein the level of current shunting is selected from the group consisting of: (1) at least 50%, (2) at least 70%, (3) at least 80%, (4) at least 90%, (5) at least 95%, and (6) at least 99%.

3. The probe of claim 1, comprising upper and lower shunting bars (3571-U, 3571- L) as shunting elements on the upper and lower probe arms (3531-UA, 3531 -LA) so that a current flow path is formed from the upper tip end (3531-U) to the upper shunt bar (3571-U) through the at least one standoff (3510) via a contact region (3570) to the lower shunt bar (3571- L) via a further contact region (3570) to the lower tip end (3531-L), or vice versa when the upper and lower tip ends (3531-U, 3531-L) are compressed toward one another.

4. The probe of claim 1, comprising shunting elements that make an electrical connection with the at least one standoff on only one side of the probe.

5. The probe of claim 1, comprising shunting elements that make an electrical connection initially with the at least one standoff on only one side of the probe and make an electrical connection to both sides of the probe only when the upper and lower tip ends are compressed toward one another.

6. The probe of claim 1, further comprising at least one bridge element joining one or more standoffs.

7. The probe of claim 1, further comprising a plurality of contact regions simultaneous contacting a plurality of shunting elements.

8. The probe of claim 1, further comprising a plurality of contact regions contacting a successively increasing number of shunting elements upon increased compression of the upper and lower tip ends toward one another.

9. The probe of claim 1, further comprising a sliding contact moving up and down along an edge of the at least one standoff as a corresponding probe tip end and probe tip arm undergo more or less compression while maintaining an electrical connection within a functional range of movement.

10. The probe of claim 9, wherein the probe tip is an offset tip that favors a tilting of the probe tip arm and the sliding contact.

11. The probe of claim 9, wherein the sliding contact is a one sided face-to-face contact that favors a tilting of the probe tip arm.

12. The probe of claim 1, further comprising dielectric elements coupled to at least one compliant element for inhibiting flow of current through a corresponding spring element.

13. The probe of claim 1, wherein the first compliant element (3521-U) comprises as a spring element a two-dimensional substantially planar spring when not biased, so that the first compliant element provides compliance in a direction substantially perpendicular to the planar configuration.

14. The probe of claim 1, wherein the second compliant element (3521-L) comprises a spring element selected from the group consisting of: (A) a two-dimensional substantially planar spring, or (B) a spring.