Title: Probes with Planar Unbiased Spring Elements for Electronic Component Contact

Field of the Present Disclosure:

[01] Embodiments of the present disclosure 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 methods 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 Present Disclosure:

Probes:

[02] 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.

Electrochemical Fabrication:

[03] 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 Van Nuys, California under the process names EFAB and MICA FREEFORM®.

[04] 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. [05] 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 Present Disclosure:

[06] It is an object of some embodiments of the present disclosure to provide improved 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.

[07] It is an object of some embodiments of the present disclosure to provide improved probes that include compliant elements formed from one or more compliant modules that include planar but non-linear (i.e., not straight) spring configurations, when unbiased, where the normals to planes of the springs are not perpendicular to a longitudinal axis of the probes and deflection of the springs out of the planes of the undeflected springs provide a majority of the compliance along the longitudinal axis of the probes. In some cases, the probe springs may extend laterally in the plane or planes of the layers from which the probe or probes are formed (i.e., the planes of the springs are perpendicular to a stacking direction of the layers from which the probe is formed) while the probe axis (extending from tip-to-tip) may not be perpendicular to the planes of the spring or springs (e.g., due to an intentional lateral offset between the opposing ends of the probe). In some variations, the probe axis may be substantially perpendicular to the plane or planes of the springs where “substantially” refers to an angular mismatch of less than 20°, less than 10°, less than 5°, less than 2°, or less than 1 ° and should be interpreted as the broadest of these unless specially indicated otherwise.

[08] It is an object of some embodiments of the present disclosure to use individual compliant modules as probes with a single contact tip.

[09] It is an object of some embodiments of the present disclosure to use individual compliant modules as probes with two oppositely facing contact tips.

[10] It is an object of some embodiments of the present disclosure to provide two or more compliant modules with reversed orientations to provide probes with two oppositely oriented contact surfaces or tips. [11] It is an object of some embodiments of the present disclosure to provide probes and/or compliant modules with base features for engaging array structures or for engaging tips of other compliant modules.

[12] It is an object of some embodiments of the present disclosure to provide probes and/or compliant modules with tip features for engaging tips or base structures of other compliant modules.

[13] It is an object of some embodiments of the present disclosure to provide array structures with through holes configured for accepting inserted probes or compliant modules, for retaining probes or compliant modules by limiting extent of insertion from at least one direction based, at least in part, on at least one feature of the array structure.

[14] It is an object of some embodiments of the present disclosure to provide probes or compliant modules with features for engaging through holes in array structures such that the probes or the compliant modules are retained by limiting extent of insertion from at least one direction based, at least in part, on one or more features of the probes or compliant modules.

[15] It is an object of some embodiments of the present disclosure to provide probes formed from compliant modules that include multiple spring elements wherein the spring elements support probe arms that support probe tips with at least two probe tips pointing in opposite directions which are configured for contacting different electronic components, such as a device under test DUT and an interface element to a test circuity such as a space transformer, an interposer or a PC B connected thereto.

[16] Other objects and advantages of various embodiments of the present disclosure will be apparent to those of skill in the art upon review of the teachings herein. The various embodiments of the present disclosure, 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 without necessarily addressing any particular object set forth above. As such, it is not necessarily intended that all objects set forth above, or even a majority of the objects set forth above, or even a plurality of the objects set forth above, be addressed by any single aspect of the present disclosure or embodiment of the present disclosure even though that may be the case regarding some aspects or embodiments.

[17] According to the present disclosure, a probe for making contact between two electronic circuit elements, includes at least one compliant structure which comprises: at least one standoff structure having a first end and a second end that are longitudinally separated; at least one first compliant element providing compliance in a direction substantially perpendicular to its planar configuration, wherein a first portion of the first compliant element functionally joins first standoffs of the at least one standoff structure and a second portion of the first compliant element functionally joins a first tip arm that can elastically move relative to the first standoffs of at least one standoff structure, wherein the first tip arm directly or indirectly holds a first probe tip that extends longitudinally beyond the first end of the first standoffs of the at least one standoff structure when the first compliant element is not biased; and at least one second compliant element providing compliance in a direction substantially perpendicular to its planar configuration, wherein a first portion of the second compliant element functionally joins second standoffs of the at least one standoff structure and a second portion of the second compliant element functionally joins a second tip arm that can elastically move relative to second standoffs of the at least one standoff structure, wherein the second tip arm directly or indirectly holds a second probe tip that extends longitudinally beyond the second end of the second standoffs of at least one standoff structure when the second compliant element is not biased, wherein the first and second compliant elements are longitudinally spaced from one another by the at least one standoff structure, and wherein at least one of the first and second compliant elements has a first portion beginning at the respective first and second standoffs of the at least one standoff structure as a first plurality of N1 laterally separated planar cantilever beams and a second portion ending at the first tip arm as a second plurality of N2 longitudinally spaced planar cantilever beams that functionally join directly or indirectly to one another wherein N2 is at least 2 and is greater than N1 .

[18] Numerous variations of the present disclosure exist and include, for example: (1) at least one cantilever beam of the first plurality of N1 laterally separated planar cantilever beams of the first and second compliant elements may be longitudinally divided to the respective second plurality of N2 laterally separated planar cantilever beams; (2) at least one cantilever beam of the first plurality of N1 laterally separated planar cantilever beams of the first and second compliant elements may have a thickness greater than any of the cantilever beams of the respective second plurality of N2 laterally separated planar cantilever beams; (3) the cantilever beams of the first plurality of N1 laterally separated planar cantilever beams of the first and second compliant elements may have a thickness selected from a group consisting of: (i) a same thickness with one another; and (ii) a different thickness with one another; (4) N1 may be selected from a group consisting of 1 , 2, 3, 4, 5, 6, 7, and 8 and N2 is selected from a group consisting of at least 2, 3, 4, 5, 6, 7, and 8; (5) N1 and/or N2 may be greater than 8; (6) the first portion of the first compliant element may be located closer to the first end of the first standoffs of the at least one standoff structure than is the first portion of the second compliant element and the first portion of the second compliant element may be located closer to the second end of the second standoffs of the at least one standoff structure than is the first portion of the first compliant element; (7) the first and second pluralities of laterally separated planar cantilever beams of the second compliant element may have a two-dimensional substantially planar configuration, when not biased, that is substantially parallel to planar configurations of the first and second pluralities of laterally separated planar cantilever beams of the first compliant element; (8) wherein at least one of the first and second pluralities of laterally separated planar cantilever beams of the first and second compliant elements may have a configuration selected from a group consisting of: (i) an inward rotating circular spiral, (ii) an inward rotating rectangular spiral, (iii) an inward rotating hexagonal spiral, (iv) an inward rotating octagonal spiral, (v) an inward rotating counterclockwise spiral as observed looking from the first probe tip toward the second probe tip, and (vi) an inward rotating clockwise spiral as observed looking from the first probe tip toward the second probe tip; (9) at least one of the first and second pluralities of laterally separated planar cantilever beams of the first and second compliant elements may have a rotational extent selected from a group consisting of: (i) at least 180°, (ii) at least 360°, (iii) at least 540°, and (iv) at least 720°; (10) the first and second pluralities of laterally separated planar cantilever beams of the first compliant element joining the first probe tip may be spiral springs that have opposite or reverse rotational orientations relative to the first and second pluralities of laterally separated planar cantilever beams of the second compliant element joining the second probe tip which may be also spiral springs; (11) the probe may further comprise an annular base located between the first and second compliant elements; (12) the annular base may be located not longitudinally centered between the first and second compliant elements; and (13) the annular base may be located in correspondence of respective intermediate standoff portions of the second standoffs that connect to longitudinally distinct bridging standoff portions of the first standoffs.

[19] Other aspects of the present disclosure will be understood by those of skill in the art upon review of the teachings herein. Other aspects of the present disclosure may involve combinations of the above noted aspects. These other aspects of the present disclosure 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, or by the teachings of the specification as a whole.

Brief Description of the Drawings:

[20] FIGS. 1 A - 1 F 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.

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

[22] FIGS. 1 H and 11 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.

[23] FIG. 2A 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.

[24] FIG. 2B 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. 2A 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. 2A.

[25] FIG. 2C depicts a partially cut view of a probe including a plurality of spring modules.

[26] FIG. 3A1 provides a schematic flattened illustration of a probe having planar spring elements with multiple transitions and with complete reference number examples illustrated along with labeling of each beam portion with its respective reference number fragment.

[27] FIGS. 3A2 - 3G24 provide various views of a probe, or portions of the probe, according to an embodiment of the present disclosure.

[28] FIGS. 3A2 and 3A3 provide an upper and a lower isometric view of the probe.

[29] FIGS. 3B1 and 3B2 provide similar views as did FIGS. 3A2 and 3A3 with the probe rotated about its longitudinal axes so as to provide views of different probe elements.

[30] FIGS. 3C1 and 3C2 provide upper and lower exploded isometric views of the probe such that an upper compliant element may be seen separated from an intermediate standoff region which is separated from a base or frame region which in turn is separated from a lower compliant element.

[31] FIGS. 3D1 to 3D2 provide isometric views of the upper compliant element of the probe at different angles while FIGS. 3D3 and 3D4 show the compliant element with progressive cutaways so that the internal features of the compliant element can be seen including the beam changes due to transitions occurring as the beam(s) progress from the outer standoffs to the inner tip arm .

[32] FIGS. 3E1 - 3E4 provide various isometric views of the lower compliant element of the probe.

[33] FIG. 3F provides a side view of the probe of FIGS. 3A2 - 3E2 depicting the positions and extents of 24 sample layer levels from which the probe can be fabricated while FIGS. 3G1 to 3424 provide top views of each of the 24 layers or cross-sections of the probe with nine having distinct configurations.

Detailed Description of Preferred Embodiments:

Electrochemical Fabrication in General

[34] FIGS. 1 A - 11 illustrate side views of various states in an example multi-layer, multi-material 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 patternable photoresist 84 is located as shown in FIG. 1 B. In FIG. 10, 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. 1 D, a metal 94 (e.g., nickel) is shown as having been electroplated into the openings 92(a) - 92(c). In FIG. 1 E, 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. 1 F, 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. 1 H, the result of repeating the process steps shown in FIGS. 1 B - 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. 11, to yield a desired 3- D structure 98 (e.g., component or device) or multiple such structures.

[35] Various embodiments of various aspects of the present disclosure 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 - 11). 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.

[36] 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 present disclosure 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), 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.

[37] 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). The selective etching and/or interlaced material deposition can be used in association with multiple layers.

[38] 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. [39] Definitions of various terms and concepts that may be used in understanding the embodiments of the present disclosure (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.

Probes with Planar Spring Modules:

[40] Some embodiments of the present disclosure are directed to spring modules with each spring module including at least one centrally located tip attached to at least one planar compliant spring element (while in an unbiased state) which is in turn attached to a base via a connecting bridge or standoff or where the base provides at least a portion of the standoff functionality wherein an axis of primary spring compliance is perpendicular to the plane of the spring arm or arms that form the spring element. Some embodiments are directed to spring modules including compliant elements that have flat springs in the form of inward winding spirals (whether of a smooth curved configuration or of a polygonal configuration or angled configuration) that end in longitudinally extending contact tips or tip extensions, standoffs, or arms. Some embodiments are directed to probes formed as, or from, single spring modules. Some embodiments are directed to probes formed as, or from, back-to-back spring modules that may share a common base element that connects standoffs, a base element that functions as a standoff, or simply have one or more joined standoffs that connect to spring elements. Some embodiments are directed to probes formed from a plurality of spring modules in combination with other components such as probe tips (that may be separate from spring module tips), tip extensions, and sheaths. Some embodiments are directed to methods for forming spring modules; forming probes that include single spring modules, forming probes that include back-to-back spring modules, or forming probes that include a plurality of adhered or contacting spring modules built up during a process that forms and simultaneously assembles components or structures, while still others are directed to forming probe components and thereafter assembling them into working probe structures. Still other embodiments are directed to probe arrays that include one or more of the probe types noted above along with array structures (e.g., substrates, guide plates, and the like). Still other embodiments are directed to methods of making such probe arrays.

[41] Planar springs or planar compliant elements of the present disclosure 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.

[42] 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.

[43] Reference numbers are included in many figures wherein like numbers are used to represent similar structures or features in the different embodiments. In particular, when the FIGS, of the various embodiments use reference numbers, the reference numbers are provided in a 3 or 4 digit format which may be followed by letters, dashes, and/or additional numbers, wherein the first digit (from the left) represent the FIG. number while the final two or three digits to the right along with any trailing letters, dashes, or numbers represent a particular general structure or feature. When two or more figures include a reference having the same left most digits (and following letters, dashes, and additional numbers), it is intended to indicate a similarity of the features indicated. The following table sets forth these two right most digits along with supplemental letters, dashes, and numbers, and a general description of the structure or feature being represented. Here and below, relative terms like “top”, “bottom”, “upper”, “lower”, “downward”, “upward” and similar ones are intended as referring to the illustrations given in the drawings, for sake of conciseness. Similarly, terms like “left”, “right”, “above”, “below” and similar ones are used still with reference to the drawings.

Table of Reference Numbers for Structures/Features

[44] Example spring modules are shown in FIGS. 2A - 2B. FIG. 2A depicts an isometric view of an example spring module 200A 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 or bridge) 211 that bridges a longitudinal module gap MG between the spring elements 221-1 , 221-2 and the base 201. In the example of FIG. 2A, each of the two spring elements 221-1 , 221-2 takes 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 231. The spring elements 221-1 , 221-2 are separated longitudinally by a gap SG. In this example, the bridge 211 connects one end of each spring element together while the tip structure 231 connects the other ends of the spring elements 221-1 , 221-2 together via an extended portion of the tip structure 231 . The tip structure 231 is formed with a desired width TW and desired tip height TH extending above the upper spring element 221-2, and each spring element 221-1 , 221-2 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 element 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 structure 231 may be such that a desired compression of a module tip structure 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 urn (urn = micron) or less or as much as 500 urn (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 urn to 200 urn while in other example embodiments, the maximum travel distance per module may be 50 urn to 150 urn. In some embodiments, the maximum travel distance of the tip structure may be set by a hard stop such as by the deflected portion of the spring element or tip structure coming into contact with the base, by a stop structure on the base, or possibly by a surface that contacts the tip structure (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 element or tip structure 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 elements, or beam elements, of a module may have spring heights (or beams heights) SH from 1 urn, or less, to 100 urn, or more (e.g., 10, 20, 30, or 40 urn), and spring widths (or beam widths) SWfrom 1 urn or less to 100 urn or more (e.g., 10, 20, 30, or 40 urn). Tip structures may have uniform or changing geometries (e.g., with cylindrical, rectangular, conical, multi-prong, or other configurations, or combinations of configurations). Tip structures, where joining to spring beams, will generally possess larger cross-sectional widths TW than the widths SW of the spring (beam) or springs (beams) to which they connect.

[45] FIG. 2B depicts an isometric view of a second example spring module 200B that is similar to the module of FIG. 2A 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. 2A. From another perspective, the example of FIG. 2B will require more force for a 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. 2A.

[46] In other embodiments, spring modules may take different forms than those shown in FIG. 2A or FIG. 2B. 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 corners, 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).

[47] FIG. 2C depicts a partially cut view of a probe 200C including: (a) a plurality of spring modules 200A and 200B similar to those of FIGS. 2A and 2B, (b) a first or upper multimodule tip 432-U, (c) a first or upper tip support or extension arm 432-UA that may or may not be attached or bonded to a tip of the module that it directly interacts with, (c) a first or upper tip over-compression stop 435-U, (d) a second or lower tip 432-L, (e) a second tip or lower support or extension arm 432-I.A that may or may not be attached or bonded to a tip of the module that it directly interacts with, and (f) a sheath 451 (shown in a cut view that holds the spring modules in a substantially linear configuration with respect to one another as well as limiting the longitudinal extension of the tips) where the sheath has openings 442-U and 442-L for passing tip support arms 432-UA and 432-LA, respectively. Tip 432-L has a rectangular configuration that may be useful for contacting a solder bump or other protruding contact surface. In the probe design of FIG. 2C, each module, if sufficient compression occurs, reaches a compression limit upon one of two events: (1) when the central portion of the lower spring element of a spring module comes into contact with the upper surface of the module base, or (2) when the lower surface of an immediately adjacent upper module base contacts the upper surface of the lower module bridge. The probe 200C as a whole may reach a compression limit when both an upper tip support arm 432-UA and a lower tip support arm 432-I.A reach compression limits which may occur before any spring modules reach compression limits or after only a portion of the modules reach their own compression limits. Probes may have diameters of an appropriate size for the array pitch desired. For example, effective probe diameters may be as small as 100 microns, or smaller, or as large as 600 microns, or larger. In some embodiments, for example, probes may have effective diameters in the range of 250 - 350 microns for use in an array having a 400 micron pitch or they may have effective diameters in the range of 150 to 250 microns for use in an array of 300 microns. Probe heights may be set to provide effective longitudinal travel so that overtravel requirements for individual modules, probes, or arrays as a whole can be accommodated when engaging semiconductor wafers or other electronic components. For example, overtravel may be in the range of 25 microns, or less, to 400 microns, or more, and probe heights may be in the range of 150 microns, or less, to 2000 microns, or more.

[48] Numerous variations of the embodiment of the probe of FIG. 2C are possible and include for example: (1) module tips being joined to adjacent module bases or module tips may simply be contacted to adjacent module bases; (2) more than four or less than four spring modules may be used in forming a given probe; (3) some or all spring modules in a given probe may have similar spring constants and/or configurations or different spring constants and/or configurations; (4) tip arms may have compression stops located on them that are spaced from contact tips; (5) probes may have a contact tip on each end or may have a contact tip on one end and a bondable tip or attachment structure on the other end; (6) probes may have one or more fixed end caps that inhibit modules from sliding out of one or both ends of the sheath, or may have no fixed end caps; (7) probes may have sheath ends that allow spring module loading to occur and thus allow biasing of springs within the module without maintaining compressive pressure on probe end tips or that may allow spring modules to be formed in build locations that are different from working range locations within a sheath; (8) spring modules or tip arms may have sliding contacts or other contacts that allow current to be shunted away from the spring elements and instead to flow through the sheaths; (9) spring modules may be formed with some dielectric elements; (10) spring modules and/or sheaths may include dielectric elements or be separated by dielectric elements such that electrical isolation of the spring modules/tip arms from the sheaths occurs, e.g., to provide dual electrically isolated conductive current paths or to ensure that central conductive paths of one probe of an array are not inadvertently shorted to a conductive path on another adjacent probe; (11) sheaths may be formed in two or more parts that allow formation or assembly of spring modules and other components into sheaths to form probes; (12) a plurality of spring modules may be formed in an attached manner to one another to provide a monolithic compliant structure (with or without tip arms and tips) that may be formed fully within a sheath, partially within a sheath for which loading will be completed subsequent to formation, or separate from a sheath for later assembly into a sheath; (13) split sheaths may be formed with snap together features that provide for easy assembly after formation; and (14) holes or openings may be made at selected locations of the spring modules or the sheaths to provide improved access of a sacrificial material etching to interior portions which might be useful when the probe or modules are formed using a multi-material, multi-layer electrochemical fabrication process that involves a sacrificial material that must be removed.

[49] FIG. 3A1 provides a schematic flattened representation of a probe 3400 also shown in FIGS. 3A2 - 3G24 wherein the illustrated probe 3400 has spring elements with multiple transitions and with complete reference number examples illustrated along with labeling of each beam portion with its respective reference number fragment. The probe 3400 of FIG. 3A1 includes upper and lower compliant elements UC1 , UC2, and LC1 , LC2 with an intermediate base/standoff structure 3401 and central tip arms 3431 -UA and 3431 -l_A extending through the compliant elements 3421 -Uc and 3421 -LC and ending in protruding probe tips 3431-U and 3431-L. The upper and lower compliant elements UC1 , UC2, and LC1 , LC2 comprise respective cantilever elements or beams UC1-1 and UC2-1 , LC1-1 and LC2-1 (e.g., that may be laterally intertwined at the same longitudinal level/levels) which transition from upper and lower standoffs 3411-1 , 3411-2 and 3412-2, 3412-2 to upper and lower central tip arms 3431 -UA and 3431 -l_A, in turn connected to upper and lower probe tips 3431-U, 3431- L.

[50] More particularly, the lower compliant element 3421-LC has a first plurality of N1 , in particular two coplanar cantilever spring elements or beams LC1-1 and LC2-1 , each being initially divided or transition from respective lower standoff 3412-1 , 3412-2 to a lower probe tip 3431-L from a single thick spring portion or cantilever beam LC1-1 or LC2-1 to a plurality of N2, in the example two thinner cantilever beams LC1-1-1 and LC1-1-2, or LC2-1-1 and LC2-1-2, the thick cantilever beam having a height along a longitudinal axis of the probe 3400, defined as the axis connecting the upper and lower probe tips 3431-U, 3431-L of the probe 3400, which is greater than a height of a thinner cantilever beam. The thinner cantilever beams LC1-1-1 and LC1-1-2, or LC2-1-1 and LC2-1-2 may also have same thicknesses or different thicknesses, as in the example shown in the figures, and in turn transition via an increasing plurality (N2>N1), in particular a three to one split and a two to one split to a total of 5 even thinner cantilever beams LC1-1-1-1 , LC1-1-1-2, LC1-1-1-3, LC1-1-2-1 and LC1-1-2-2, or LC2-1-1-1 , LC2-1-1-2, LC2-1-1-3, LC2-1-2-1 and LC2-1-2-2 (i.e., a 1 to 2 to 5 beam split), which are connected to the lower probe tip 3431 -L.

[51] Similarly, the upper compliant element 3421-UC has two coplanar spring elements UC1-1 and UC2-1 that each transition from respective upper standoffs 3411-1 , 3411- 2 to an upper probe tip 3431 -U from a single thick cantilever beam UC1-1 or UC2-1 to two thinner cantilever beams UC1-1-1 and UC1-1-2, or UC2-1-1 and UC2-1-2 with the same thicknesses which in turn transition via a pair of three to one splits to a total of six even cantilever thinner beams UC1-1-1-1 , UC1-1-1-2, UC1-1-1-3, UC1-1-2-1 , UC1-1-2-2 and UC1-1- 2-3, or UC2-1-1-1 , UC2-1-1-2, UC2-1-1-3, UC2-1-2-1 , UC2-1-2-2 and UC2- 1-2-3 (i.e., a 1 to 2 to 6 beam split), which are connected to the upper probe tip 3431-U. The reference scheme illustrated in FIG. 3A1 is used, as appropriate, when referencing specific probe features in FIGS. 3A2 to 3G24.

[52] FIGS. 3A2 - 3G24 provide various views of a probe 3400, or portions of the probe, according to an embodiment of the present disclosure where the probe 3400 includes a lower complete compliant element 3421-LC including a pair of coplanar inward rotating cantilever spring elements LC1-1 and LC2-1 starting at two separated lower standoffs 3412-1 and 3412-2 and joining one another at a central lower tip arm 3431 -l_A which in turn joins or becomes the lower probe tip 3431 -L with the cantilever spring elements LC1-1 and LC2-1 being initially divided (or undergoing a transition) along their inward lateral paths from thick, coplanar, cantilever beams LC1-1 and LC2-1 into two longitudinally separated thinner cantilever beams LC1-1-1 and LC1-1-2, LC2-1-1 and LC2-1-2 of same thicknesses or different thicknesses, an in the example shown in the figures, wherein cantilever beam LC1-1 transitions to (a) LC1-1-1 and (b) LC1-1-2 while cantilever beam LC2-1 transitions to (a) LC2-1-1 and (b) LC2-1-2. These four cantilever beams LC1-1-1 , LC1-1-2, LC2-1-1 , LC2-1-2 further each divide into two or three longitudinally separated spring portions or cantilever beams, respectively with LC1-1-1 becoming (a) LC1-1-1-1 , (b) LC1-1-1-2, and (c) LC1-1-1-3; LC2-1-1 becoming (a) LC2-1-1-1 , (b) LC2-1-1-2, and (c) LC2-1-1-3; LC1-1-2 becoming (1) LC1-1-2-1 and (2) LC1-1-2-2; and LC2-1-2 becoming (a) LC2-1-2-1 and (b) LC2-1-2-2 to provide a total of two sets of five thinner longitudinally separated cantilever beams before joining the lower central tip arm 3431-LA

[53] The probe 3400 also includes an upper complete cantilever element 3421-UC including a pair of coplanar inward rotating cantilever spring elements UC1-1 and UC2-1 starting at two separated upper standoffs 3411-1 and 3411-2 and joining one another at an upper central tip arm 3431 -UA which in turn joins to or becomes the upper probe tip 3431-U with the two coplanar cantilever spring elements UC1-1 and UC2-1 being divided along their inward lateral paths from two cantilever spring portion or beams UC1-1 and UC2-1 into two longitudinally separated cantilever spring portions or beams UC1-1-1 and UC1-1-2, UC2-1-1 and UC2-1-2 of the same thicknesses with UC1-1 transitioning to (a) UC1-1-1 and (b) UC1-1-2 while UC2-1 transitions to (a) UC2-1-1 and (b) UC2-1-2. These four cantilever spring portions or beams UC1-1-1 , UC1-1-2, UC2-1-1 , UC2-1-2 each in turn further divide into three longitudinally separated cantilever beams, respectively with UC1-1-1 becoming (a) UC1-1-1-1 ,

(b) UC1-1-1-2, and (c) UC1-1-1-3; with UC2-1-1 becoming (a) UC2-1-1-1 , (b) UC2-1-1-2, and

(c) UC2-1-1-3; with UC1-1-2 becoming (a) UC1-1-2-1 , (b) UC1-1-2-2, and (c) UC1-1-2-3; and with UC2-1-2 becoming (a) UC2-1-2-1 , (b) UC2-1-2-2, and (c) UC2-1-2-3 to provide a total of two pairs of six thinner longitudinally separated cantilever spring portions or beams that join, or become, the upper central tip arm 3431-UA which joins to, or becomes, the upper probe tip 3431 -U.

[54] Moreover, the probe 3400 comprises a longitudinally off center base or frame 3401 which is located above the lower complete compliant element 3421-LC and below the upper complete compliant element 3421 -UC as well as below an intervening longitudinal region 3450 occupied only by lower portions of the upper standoffs 3411-1 and 3411 (i.e. , portions of the upper standoffs 3411-1 and 341 Iwhich are closer to the bottom of the probe 3400 than to the top of the probe 3400). The base 3401 takes the form of an annular ring including two coplanar intermediate standoff portions or extensions 3414-1 and 3414-2 that connect the lower standoffs 3412-1 and 3412-2 of the lower complete compliant element 3421-LC to longitudinally distinct bridging standoff portions 3413-1 and 3413-2 of the upper standoffs 3411-1 and 3411-2 that join to the upper compliant element 3421 -UC via its internal standoffs regions 3411-1 and 3411-2.

[55] FIGS. 3A2 - 3A3, respectively, provide upper and lower isometric views of probe 3400 with the probe 3400 as viewed having a particular rotation about its longitudinal axis while FIGS. 3B1 and 3B2 provide similar views but with counterclockwise, longitudinal rotations (of about 45°) to provide a clearer view of the interior of the probe 3400 below the upper complete compliant element 3421-UC and above the lower complete compliant element 3421-LC such that the upper portion of the lower complete compliant element 3421-LC can be seen (FIG. 3B1) and the lower portion of the upper complete compliant element 3421-UC can be seen (FIG.3B2). The upper probe tip 3431-U is visible in FIGS. 3A2 and 3B1 while the lower probe tip 3431 -L can be seen in FIGS. 3A3 and 3B2. Various cantilever spring portions or beams for the upper and lower complete compliant elements 3421-UC and 3421-LC are visible with some of them being labeled including UC1-1 , LC1-1 , UC1-1-1 , LC1-1-1 , UC1-1-2, LC1-1-2, UC2-1 , LC2-1 , UC2-1-1 , LC2-1-1 , UC2-1-2 and LC2-1-2.

[56] FIGS. 3C1 and 3C2, respectively, provide exploded isometric views of probe 3400 from above (FIG. 3C1) and below (FIG. 3C2). The upper spring region, or upper complete compliant element 3421-UC, parts of its individual cantilever spring portions or beams (including UC1-1 , UC2-1 , UC1-1-1 , UC1-1-2, UC2-1-1 , UC2-1-2, UC1-1-1-1 , UC2-1-1-1 , UC1- 1-2-3, and UC2-1-2-3), and its upper standoffs 3411-1 and 3411-2, the upper probe tip 3431-U, and a part of the upper tip arm 3431 -UA can be seen in the upper most portions of the figures. Longitudinally distinct upper bridging standoffs 3413-1 and 3413-2 can be seen in the upper intermediate portion of the figures wherein the upper bridging standoffs 3413-1 and 3413-2 connect the upper compliant element 3421 -UC to the base 3401 being a connection ring (or retention ring, or frame) 3401 and its coplanar intermediate standoff portions or extensions 3414-1 and 3414-2 as can be seen in the lower intermediate portion of the figures. The base 3401 (or at least the intermediate standoff portions 3414-1 and 3414-2 included therein) join the lower complete compliant element 3421-LC which can be seen in the lower most portion of the figures along with labeling for portions of its individual cantilever spring portions or beams including LC1-1 , LC2-1 , LC1-1-1 , LC1-1-2, LC2-1-1 , LC2-1-2, LC1-1-1-1 , LC2-1-1-1 , LC1-1-2- 2, and LC2-1-2-2. The lower standoffs 3412-1 and 3412-2 for the lower compliant element 3421-LC can also be seen along with a portion of the lower tip arm 3431-LA, and the lower probe tip 3431 -L.

[57] FIGS. 3D1 to 3D2 show isometric views of the upper complete compliant element 3421-UC of probe 3400 at different angles while FIGS. 3D3 and 3D4 show element 3421-UC with progressive cutaways so that the internal features of the element can be seen including the beam changes that result from transitions occurring as the beam progresses from the outer upper standoffs 3411-1 and 3411-2 to the upper tip arm 3431-UA. More particularly, the figures show that the upper complete compliant element 3421-UC includes, among other features, two coplanar, laterally interlaced, inward rotating cantilever spring portions or beams UC1-1 and UC2-1 (being spiral springs or beams rotating clockwise when viewed from above) that meet at the central upper tip arm 3431 -U after dividing through two transitions into a total of six cantilever beams per spiral. The two coplanar spiral cantilever beams UC1-1 and UC2-1 start as relatively thick cantilever beams UC1-1 and UC2-1 with an unbroken longitudinal height but then each split (or transition) into lower and upper cantilever spring portions or beams with UC1-1 transitioning to lower beam UC1-1-1 and upper beam UC-1-1-2 while UC2-1 transitions to lower beam UC2-1-1 and upper beam UC2-1-2. Each of these four beams UC1-1-1 , UC1-1- 2, UC2-1-1 , UC2-1-2 thereafter split into three separate portions wherein (1) UC1-1-1 transitions to portions (a) UC1 -1-1-1 on the bottom, (b) UC1-1-1-2 in the middle, and (c) UC1-1- 1-3 on top; (2) UC1-1-2 transitions to portions (a) UC1-1-2-1 on the bottom, (b) UC1-1-2-2 in the middle, and (c) UC1-1-2-3 on top; (2) UC2-1-1 transitions to portions (a) UC2-1-1-1 on the bottom, (b) UC2-1-1-2 in the middle, (c) UC2-1-1-3 on top; and (4) UC2-1-2 transitions to portions (a) UC2-1-2-1 on the bottom, (b) UC2-1-2-2 in the middle, and (c) UC2-1-2-3 on top. These twelve beam portions provide six coplanar pairs of cantilever beams that join to opposite sides of the upper tip arm 3431-UA.

[58] FIGS. 3E1 - 3E4 provide various isometric views of the lower complete compliant element 3421-LC of the probe 3400 with FIGS. 3E1 and 3E2 showing a bottom and a top view of the lower complete compliant element 3421-LC while FIGS. 3E3 and 3E4 provide cut away views of the interior of the element such that changes to the cantilever spring portions or beams can be seen due to the transitions occurring as the beams progress from outer lower standoffs 3412-1 and 3412-2 to the inner central lower tip arm 3431-LA. More particularly, the views of FIGS. 3E1 - 3E4 show that the lower complete compliant element 3421-LC includes two laterally interlaced inward rotating coplanar cantilever spring portions or beams LC1-1 and LC1-2, being spiral springs or beams that rotate in a counterclockwise direction when seen from above and that meet at a central, lower tip arm 3431-LA which in turn joins or becomes the lower probe tip 3431 -L. It can also be seen that the two coplanar spiral cantilever beams LC1-1 and LC1-2 start as single thick cantilever beams LC1-1 and LC2-1 but then with each becoming split into upper and lower cantilever spring portions or beams LC1-1-1 and LC1-1-2, LC2-1-1 and LC2- 1-2 with the upper cantilever beam LC1-1-1 or LC2-1-1 being thicker (along the longitudinal axis) than the lower cantilever beam LC1-1-2 or LC2-1-2. As the inward spiral cantilever beams progress, additional splitting occurs that creates a total of five cantilever spring portions or beams from each of LC1-1 and LC2-1. As the spiral cantilever beams inward, cantilever beam LC1-1 transitions to portions LC1-1-1 on top and LC1-1-2 on the bottom. Further along the inward spiral cantilever beams, LC1-1-1 transitions to three thinner portions LC1-1-1-1 on top, LC1-1-1-2 in the middle, and LC1-1-1-3 on the bottom while LC1-1-2 transitions to two thinner portions LC1-1-2-1 on top and LC1-1-2-2 on the bottom. In a similar manner, coplanar cantilever beam LC2-1 transitions to upper portion LC2-1-1 and lower portion LC2-1-2. Further along the inward spiral cantilever beams, LC2-1-1 transitions to three portions LC2-1-1-1 on top, LC2-1-1-2 in the middle, and LC2-1-1-3 on the bottom while LC2-1-2 transitions to two portions LC2- 1-2-1 on top and LC2- 1-2-2 on the bottom. In total, the transitions provide ten cantilever beams in five coplanar pairs with members of each pair joining to opposite sides of the lower tip arm 3431-LA.

[59] FIG. 3F provides a side view of the probe 3400 showing 24 sample layers labeled as L1 - L24 and their longitudinal boundaries or levels that may be used in forming the probe or a plurality of such probes simultaneously. The relative thickness of the individual layers is depicted by the spacing of the layer boundary lines illustrated in the figure with, in this example, layer thicknesses ranging from about 5 to 60 microns, an overall probe height being between 400 - 450 microns, and an overall diameter being between 300 - 400 microns. In other embodiments, these sizing constraints can take on different values. In some embodiments, a multi-layer fabrication process may be used to form the probe 3400 such as by using a 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 3400. Though probes may be formed one at a time, generally it is preferred that probes be formed in batch with hundreds or even thousands of probes formed simultaneously by successive layer-upon-layer build up. L1 provides the lower probe tip 3431 -L. L2 - L10 provide the lower complete compliant element 3421-LC (excluding the lower probe tip 3431 -L) including its lower standoffs and its spiral cantilever spring portions or beams that split from an initial coplanar pair of thick cantilever beams to two thinner coplanar beam pairs and then to five even thinner coplanar beam pairs as the inward spiral cantilever beams progresses from outer lower standoffs to the central lower tip arm 3431 -LA. L11 provides for annular base 3401 and associated joined standoffs. L12 provides for a pair of bridging or longitudinally distinct upper standoffs. Layers L13 - L23 provide the upper complete compliant element 3421 -UC (excluding the upper probe tip 3431 -U) including its standoffs and its spiral cantilever spring portions or beams that split from an initial coplanar pair of thick cantilever beams to two coplanar thinner beam pairs and then to six even thinner coplanar beam pairs as the spirals progress from outer upper standoffs to the central upper tip arm 3431 -UA. L24 provides the upper probe tip 3431 -U. In the present example, only nine of the twenty-four layers have unique cross-sectional configurations.

[60] FIGS. 3G1 to 3G24 illustrate top views of cross-sectional structural material conf igurations with features identified by their relevant reference numbers and associated layer designations as appropriate. FIGS. 3G1 and 3G24 provide identical configurations but with different reference labeling being used as they present different portions of the probe (i.e. , a lower tip 3431-L and an upper tip 3431-U). FIGS. 3G2, 3G4, 3G6, 3G8, and 3G10 all provide similar configurations for the complete spiral cantilever spring portions or beams of the lower compliant element but with different reference labeling used to better distinguish different portions of different spring portions or beams wherein the distinctions are primarily based on how different beam portions connect to one another and to their respective supporting standoffs. Likewise FIGS. 3G3, 3G5, 3G7, and 3G9 have identical cross-sections, as do FIGS. 3G13, 3G15, 3G17, 3G19, 3G21 , and 3G23, and as do FIGS. 3G14, 3G16, 3G18, 3G20, and 3G22. In addition to providing top views of the cross-sectional configurations of the layers of the probe, FIGS. 3G1 to 3G24 also provide a dashed alignment element 3409 which provides a conceptual, lateral stacking alignment or registration reference for the structural material of successive figures. Alternative configurations and layer counts are possible not only to accommodate different geometries and provide for different configurational and functional characteristics that may be required by particular applications but also to allow multiple materials to be applied during the formation of some layers so that different probe features may be formed with optimized material properties.

[61] Numerous variations of the embodiment of FIGS. 3A2 - 3G24 are possible and include, for example: (1) use of the same or different materials for different portions of the probe including, in some variations, use of specialized contact materials, spring materials, highly conductive materials, bonding materials, specialized coating materials and/or inclusion of one or more dielectric materials and/or to provide for the interlocking of different materials to one another as opposed to relying solely on interlayer or intralayer adhesion for maintaining structural integrity; (2) variations in configurations including the number of layers from which a probe is formed, changes to layer thicknesses, number of rotations or partial rotations that each planar spring element incorporates, the number of coplanar 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 existence of, lack of existence of, numbers of, and/or locations of longitudinal beam transitions that occur along the length of the spirals, the direction of rotation that successive spirals take (e.g., CW-CW, CCW-CW, or CCW-CCW, or CW-CCW), the shapes of the tip, and/or the width and thickness of the cantilever beams; (3) use of planar spring configurations that are not spirals or that do not include spiral features; (4) use of standoffs that provide different positioning of the upper and/or lower spring modules laterally or longitudinally relative to a frame or base; (5) use of standoffs that are closer to the lateral central portion of the probes as opposed to the outer perimeter of the probes; (6) use of different types of frame or base structures and/or openings in such frame and base structures; (7) use of a multi-part base that is separated into two or more longitudinally separated elements that join the standoffs at a plurality of longitudinal levels; (8) use of more than two standoffs; (9) use of a single standoff that encircles more than half of the perimeter of the probe, (10) use of a standoff that includes holes or a grid-like configuration to provide enhanced access to an interior portion of the probe (e.g., for fabrication related purposes such as etching away sacrificial material or cleaning purposes); (11) use of a base that includes not only longitudinally separated elements but also laterally separated elements that may, for example, provide for insertion into openings in one or more array frame elements in a given rotational orientation to a certain longitudinal level and then be rotated about the longitudinal axis to lock the probes and the frame elements together or to allow further insertion (e.g., using stair-stepped threaded engagement configurations); (12) use of more than one upper and/or more than one lower compliant element; (13) use of cantilever elements that originate from different standoff regions but also are not coplanar but are at least in part longitudinally offset relative to cantilevers that start from a different standoff region, and (14) formation of probes with different heights, widths, spring dimensions, standoff heights, and various operational parameters like over travel, stress, strain, spring force, and the like to accommodate the needs in different usage applications.

Further Comments and Conclusions:

[62] Numerous embodiments have been presented above, but many additional embodiments are possible without deviating from the spirit of the present disclosure. Some of these additional embodiments may be based on a combination of the teachings herein with various teachings of the prior art. 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), nickelphosphorous (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 for their 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 disclosure for non-probing purposes (e.g., to bias other operational devices with a desired spring force or compliant engagement).

[63] It will be understood by those of skill in the art that additional operations may be used in implementing the above presented embodiments or used in variations of the above presented embodiments. These additional operations may, for example, provide: (1) surface cleanings , (2) surface activations, (3) heat treatments (e.g., to improve interlayer adhesion, to improve properties of selected materials or features of the probes, such as yield strength, spring constant and the like), (4) provide conformal coatings, (5) provide surface smoothing, roughening, or other surface conditioning, (6) provide surface texture, (7) provide doping of primary materials with secondary materials to provide improved material properties, and/or to provide (8) process monitoring, testing, and/ or measurements to ensure that fabrication occurs according to specifications or other requirements (which may be set by customers, users, quality standard testing, or process standards defined by the process operator itself) as part of ensuring that manufactured parts or products that are supplied to customers or end users are fully functional and meet all requirements. [64] It will also be understood that the probe elements of some aspects of the present disclosure 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 present disclosure need to be formed by only those processes taught herein or by processes made obvious by those taught herein.

[65] 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.

[66] It is intended that any aspects of the present disclosure set forth herein represent independent disclosure descriptions which Applicant contemplates as full and complete disclosure 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 a disclosure being claimed by those respective dependent claims should they be written.

[67] In view of the teachings herein, many further embodiments, alternatives in design and uses of the embodiments of the instant disclosure will be apparent to those of skill in the art. As such, it is not intended that the present disclosure be limited to the particular illustrative embodiments, alternatives, and uses described above but instead that it be solely limited by the claims presented hereafter.