Probe array incorporating probes that have selected mechanical properties manipulated during formation of at least portions of the probes and corresponding fabrication method

Abstract

Probe structures, probe arrays, have varying intrinsic material properties along their lengths. Methods of forming probes and probe arrays comprise varying the process parameters to provide varying intrinsic material properties, the probe arrays comprising suitable retention structures holding the plurality of probes in a desired array pattern.

Description

PROBE ARRAY INCORPORATING PROBES THAT HAVE SELECTED MECHANICAL PROPERTIES MANIPULATED DURING FORMATION OF AT LEAST PORTIONS OF THEPROBES AND CORRESPONDING FABRICATION METHODField of the Invention:

[0001] The present invention relates generally to the field of plated metal structures and more particularly, in some embodiments, to methods of forming probe preforms, probes, probe preform arrays, probe arrays, or subarrays for testing (e.g. wafer level testing or socket testing) of electronic components (e.g. integrated circuits), and even more particularly, the formation of such arrays or subarrays to provide in situ variations in material properties along a longitudinal length of the probes and / or to provide in situ variations in deposition template configuration and thus probe shape along lengths of the probes while being formed in array configurations.Background of the Invention:

[0002] Probes:

[0003] Numerous electrical contact probe and pin configurations as well as array formation methods have been commercially used or proposed, some of which may be prior art while others are not.

[0004] As the pitch requirements of probing applications get more demanding, i.e. , as tighter pitches are needed, achieving the required contact force without exceeding the yield stress of the material used becomes increasingly challenging, and as such, a need exists for methods for creating probe arrays allowing tailored control of material properties so that such requirements can be met.Summary of the Invention:

[0005] It is a first object of some embodiments of the invention to provide an improved method of forming a probe array incorporating probes that have selected mechanical properties manipulated during formation of at least portions of the probes.

[0006] It is a second object of some embodiments of the invention to provide an improved method of forming probe arrays that incorporate multi-photon lithography in patterning at least portions of plating template material.

[0007] It is a third object of some embodiments of the invention to provide improved probes and probe arrays.

[0008] Other objects and advantages of various embodiments of the invention will be apparent to those of skill in the art upon review of the teachings herein. The various embodiments of the invention, set forth explicitly herein or otherwise ascertained from the teachings herein, mayaddress one or more of the above objects alone or in combination, or alternatively may address some other object ascertained from the teachings herein. It is not intended that all objects, or even multiple objects, be addressed by any single aspect or embodiment of the invention even though that may be the case regarding some aspects.

[0009] In a first aspect of the invention a probe array, includes: (a) a plurality of probes, including: (i) an elastically deformable body portion having a first end and a second end; (ii) a first contact region connected directly or indirectly to the first end of the elastically deformable body portion; and (iii) a second contact region connected directly or indirectly to the second end of the elastically deformable body portion, wherein multiple probes of the plurality of probes comprise at least one first portion made of at least one selected material located within at least two different second portions along a length of each of the multiple probes wherein the at least one selected material at the at least two different second portions has at least one intrinsic material property having a first value being different from a second value of the intrinsic material property of the at least one selected material at the at least one first portion, the at least one selected material being the structural material forming at least a portion of the probes; and (b) at least one probe array retention structure holding the plurality of probes in an array pattern desired for the probe array.

[0010] Numerous variations of the first aspect exist and include for example: (1 ) the intrinsic material property of the at least one selected material may be independent of the amount of the selected material and the shape of the selected material present at the first portion and at the second portions; (2) the intrinsic material property of the at least one selected material may have a plurality of values at a plurality of different portions of each of the multiple probes; (3) the intrinsic material property of the at least one selected material may be selected from a group consisting of: yield strength, elastic modulus or Young’s modulus, modulus of resilience and electrical resistance; (4) when the intrinsic material property of the at least one selected material is the elastic modulus, the difference between a first elastic modulus and a second elastic modulus, having a value smaller than the first elastic modulus, may be selected from a group consisting of: (a) at least 10% of the second elastic modulus, (b) at least 20% of the second elastic modulus, (c) at least 40% of the second elastic modulus, (d) at least 70% of the second elastic modulus, (e) at least 100% of the second elastic modulus, and (f) at least 140% of the second elastic modulus; (5) at least two different second portions may be separated by an amount selected from a group consisting of: (a) at least 5 microns, (b) at least 10 microns, (c) at least 20 microns, (d) at least 50 microns, and (e) at least 100 microns; (6) the at least one probe array retention structure may be selected from a group consisting of: (i) a substrate to which the first contact regions (100A) of the probes are bonded at a plurality of bonding locations; (ii) a substrate to which the first contact regions of the probes are bonded at a plurality of bonding locations along with at least one guideplate having a plurality of holes which engage the probes; (iii) a substrate to which the first contact regions of the probes are bonded at a plurality of bonding locations along with at least one guide plate having a plurality of holes which engage the probes wherein the holes in at least one guide plate are laterally shifted relative to the bonding locations on the substrate; (iv) a plurality of guide plates each having a respective plurality of holes which engage the probes; (v) a plurality of guide plates each having a respective plurality of holes which engage the probes (100), wherein at least two of the plurality of guide plates have respective holes that engage probes that are laterally aligned; (vi) a plurality of guide plates each having a respective plurality of holes which engage the probes, wherein at least two of the plurality of guide plates have respective holes that engage probes that are laterally shifted with respect to one another; and (vii) a retention plate provided with a plurality of retention holes into which the probes are inserted; (7) the at least one retention structure may be a retention plate which has thickness selected from a group consisting of: (a) at least 14 of a longitudinal length of the probes; (b) at least 2 of a longitudinal length of the probes; and (c) at least % of a longitudinal length of the probes, the longitudinal length of the probes extending from the first contact region to the second contact region; (8) each of a plurality of the probes may comprise a plurality of adhered layers; (9) the first contact region may be configured for a function selected from a group consisting of: (a) making temporary pressure based electrical contact to a first electronic component upon elastically biasing the elastically deformable body portion with the first contact region against the first electronic component, and (b) bonding to the first electronic component for making permanent contact; (10) the second contact region may be configured for making temporary pressure based electrical contact to a second electronic component upon elastically biasing the elastically deformable body portion with the second contact region against the second electronic component; (11) the first portion and at least one of the two different portions of the multiple probes form a compliant or spring portion of each probe, the compliant or spring portion having a preformed shape, an inclined shape extending between at least two bends along the length of the probe, or a curved or multi-angled shape comprising a plurality of curved or angled segments; (12) the at least one probe array retention structure may comprises a plurality of guide plates each having a respective plurality of holes which engage the probes, wherein at least two of the plurality of guide plates have respective holes that engage probes that are further laterally shifted with respect to one another starting from the shape of the compliant or spring portion to further incline the compliant or spring portion with respect to its initial configuration; (13) the probes may further comprise additional materials being co-deposited, selectively coated, or blanket coated over the formed probes.

[0011] In a second aspect of the invention a method of forming a probe array, includes: (a) forming a plurality of probes, comprising: (i) providing a probe substrate; (ii) directly or indirectly onthe probe substrate, providing at least one patterned template with a plurality of openings; (iii) providing a structural material into the plurality of openings to form at least a portion of the plurality of probes, wherein the providing of the structural material comprises varying intrinsic properties of the structural material at different heights along a length of the probes; and (b) providing at least one probe array retention structure to engage the plurality of probes according to an array pattern desired for the probe array.

[0012] Numerous variations of the second aspect exist and include for example: (1 ) varying intrinsic properties of the structural material may comprise varying processing parameters of a process operation forming the structural material as the process operation progresses from bottom to top within the plurality of openings in the patterned template; (2) the process parameter may be varied in a continuous manner; (3) providing at least one patterned template may comprise providing a plurality of layers of photoresist directly or indirectly on the probe substrate wherein the plurality of openings are formed; (4) a further step of deforming at least one of the plurality of layers of photoresist, before or after the formation of the openings; (5) the process operation forming the structural material may comprises a plating operation; (6) the plating operation is chosen in a group consisting of: (a) direct current plating with a current density that is fixed at any given time and is made to change from one value to another in a substantially discontinuous manner to cause relatively abrupt changes in grain size formation of deposited metals and changes in a process parameter being a yield strength of the deposited structural material at a given height of deposition, wherein times between current density changes range from seconds to tens of seconds or even to minutes and the thickness of the deposited structural material at any given current density ranges from tenths of microns, to microns, to tens of microns; (b) direct current plating with relatively slow transitions in current density from one value to another, from a local temporal minimum value to a local temporal maximum value, and vice-a-versa, where such transitions occur over seconds, to tens of seconds, to even minutes uniformly in the transition between values; (c) pulsed current plating which has a first fast oscillation rate associated with the pulsing and a slower rate of change between changes to one or both of minimum and / or maximum current densities, or a duty cycle, to produce changes in material properties, wherein the fast oscillations occur with a frequency range of 1 hz to 100 hz, or faster, and a duty cycle ranging from 5% to 95% with material property variations in the resulting deposited structural material occurring based on different frequencies and duties cycles which deviate from properties resulting from a direct current deposition at a similar averaged current density; (d) reversed pulse plating with slow variations in associated parameters; (e) plating with variations in bath temperature; and (f) plating with variations in plating bath flow or agitation and / or orientation of a plating surface; (7) each probe may be provided as comprising at least one first portion and at least two different second portions, the at least one firstportion being located within at least two different second portions, the structural material at the two different second portions having an intrinsic property with a first value being different from a second value of the intrinsic property of the structural material at the at least one first portion; (8) providing at least one patterned template with a plurality of openings may comprise superimposing a plurality of layers of photoresist directly or indirectly on the probe substrate and forming the plurality of openings in the plurality of layers of photoresist plurality of layers of photoresist; (9) a further step of deforming at least one of the plurality of layers of photoresist, before or after the formation of the openings; (10) providing at least one patterned template with a plurality of openings may comprises using multiphoton lithography to pattern a photolithographic material and exposing the same to form the plurality of openings; (11 ) the multiphoton lithography may pattern the photolithographic material so to form a plurality of shaped openings of desired configurations for receiving deposited structural material to provide probes of desired configurations; (12) the multiphoton lithography may provide probes having a continuous variations in a local diameter;(13) one or more further step may be chosen in a group consisting of: (i) removing the patterned template; (ii) removing at least a portion of patterned template and using a remaining portion of the patterned template for a function selected from a group consisting of: (a) permanent attachment support for the probes, (b) temporary support to the probes until transfer to a permanent substrate is completed, (c) supplemental elastic enhancement to the probes; and (d) barrier material against probe to probe shorting; (iii) providing other patterning material for a function selected from a group consisting of: (a) permanent attachment support for the probes, (b) temporary support to the probes until transfer to a permanent substrate is completed, (c) supplemental elastic enhancement to the probes; and (d) barrier material against probe to probe shorting; (iv) planarizing the deposited structural material; (v) adding a material to the probes chosen in a group consisting of: (a) a tip material, (b) a dielectric barrier material, (c) a bonding material and (d) an enhancement bonding material; (vi) co-depositing, selectively coating, or blanket coating over the formed probes other materials chosen in a group consisting of: ceramics, nano-fibers, dielectrics, adhesion materials, barrier materials, and / or bonding materials and the like; (14) providing at least one probe array retention structure may be chosen in a group consisting of: (i) bonding the first contact region of the probes at a plurality of boding location of the array substrate, wherein the array substrate comprises the probe substrate being a build substrate; and (ii) bonding the first contact regions of the probes at a plurality of boding location of the array substrate, wherein the array substrate and the probe substrate being a build substrate are different; and (15) a further step chosen in a group consisting of. (iii) providing at least one guide plate having a plurality of holes that engage the probes; (iv) providing at least one guide plate having a plurality of holes and inserting the probes into the plurality of holes that are laterally aligned with bonding locations on the substrate; (vi)providing at least one guide plate having a plurality of holes and inserting the probes into the plurality of holes, and laterally shifting the at least one guide plate and the substrate so that the plurality of holes in the at least one guide plate are laterally shifted with respect to bonding locations on the substrate; (vii) providing a plurality of guide plates, each having a plurality of holes which engage the probes; (viii) providing a plurality of guide plates, each having a plurality of holes which engage the probes, wherein at least one of the plurality of guide plates has a plurality of holes engaging probes that are laterally aligned; (ix) providing a plurality of guide plates, each having a plurality of holes which engage the probes, wherein at least two of the plurality of guide plates have respective plurality of holes engaging probes that are laterally aligned with respect to one another; (ix) providing a plurality of guide plates, each having a plurality of holes which engage the probes, wherein at least two of the plurality of guide plates have respective plurality of holes engaging probes that are laterally shifted with respect to one another; (x) providing a plurality of guide plates, each having a plurality of holes which engage the probes, wherein at least two of the plurality of guide plates have respective plurality of holes engaging probes that are laterally shifted with respect to one another according to an initial shaped configuration of the probes and further laterally shifted to further incline the probes; (xi) providing a retention plate with a plurality of retention holes for receiving probes and inserting the probes into the plurality of retention holes; and (xi) providing a retention plate with a plurality of retention holes for receiving probes and inserting the probes into the plurality of retention holes, wherein the retention plate has a thickness selected from a group consisting of: (a) at least ! of a longitudinal length of the probes; (b) at least1 / 2 of a longitudinal length of the probes; and (c) at least % of a longitudinal length of the probes, the longitudinal length of the probes being a length from the first contact region to the second contact region thereof.

[0013] Other aspects of the invention will be understood by those of skill in the art upon review of the teachings herein and for example may include alternatives in the configurations or processes set forth herein, decision branches noted in those processes or configurations, or partial or complete exclusion of such alternatives and / or decision branches in favor of explicitly setting forth process steps or features along with orders to be used in performing such steps or connections between such features. Some aspects may provide device counterparts to method of formation aspects, some aspects may provide method of formation counterparts to device aspects, and other aspects may provide for methods of use for the probe arrays provided herein.Brief Description of the Drawings:

[0014] 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.

[0015] FIG. 1 G depicts the completion of formation of the first layer resulting from planarizing the deposited materials to a desired level.

[0016] 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.

[0017] FIGS. 2A - 2E illustrate a first embodiment providing variations of material properties at different heights along the lengths of probes or probe preforms.

[0018] FIGS. 2F1 - 2F5 illustrate side views of example probe arrays or preform arrays, in the following indicated simply as probe array, including probes of the type shown in FIG. 20 wherein the probe arrays include different types of guide and / or mounting structures.

[0019] FIGS. 3A - 3F4 illustrate a second embodiment providing variations of material properties at different heights along the lengths of probes.

[0020] FIGS. 4A - 4F4 illustrate a third embodiment that may provide varying of material properties along the lengths of probes being formed while in array configurations or simply provide unique probe configurations where the probes have a shape based on use of multi-photon lithography to provide patterning of a photoresist.

[0021] FIGS. 5A and 5B provide an example illustrating how a change in process parameters can result in material property change that can vary in a continuous manner as opposed to a discontinuous manner.

[0022] FIG. 6 shows a complex probe configuration obtained by multiphoton lithography.Detailed Description of Preferred Embodiments:

[0023] Electrochemical Fabrication in General

[0024] Various implementations of the present invention may use single or multi-layer electrochemical deposition processes.

[0025] FIGS. 1 A - 11 are provided to illustrate techniques that may be useful. FIGS. 1 A— 11 illustrate side views of various states in an example multi-layer, multi-material electrochemical fabrication process. FIGS. 1 A - 1 G 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 metals form part of the layer. In FIG. 1 A, a side view of a substrate 182 having a surface 188 is shown, onto which patternable photoresist184 is deposited, spread, or cast as shown in FIG. 1 B. In FIG. 1 C, a pattern of resist is shown that results from the curing, exposing, and developing of the resist. The patterning of the photoresist 184 results in openings or apertures 192(a)— 192(c) extending from a surface 186 of the photoresist through the thickness of the photoresist to surface 188 of the substrate 182. In FIG. 1 D, a metal 194 (e.g., nickel) is shown as having been electroplated into the openings 192(a)— 192(c). In FIG. 1 E, the photoresist has been removed (i.e., chemically stripped) from the substrateto expose regions of the substrate 182 which are not covered with the first metal 194. In FIG. 1 F, a second metal 196 (e.g., silver) is shown as having been blanket electroplated over the entire exposed portions of the substrate 182 (which is conductive) and over the first metal 194 (which is also conductive). FIG. 1 G 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. 1 1 to yield a desired 3-D structure 198 (e.g., component or device).

[0026] Some Definitions

[0027] Definitions of various terms and concepts that may be used in understanding the embodiments of the invention (either for the devices or structures themselves, certain methods for making the devices or structures, or certain methods for using the devices or structures) will be understood by those of skill in the art.

[0028] The term “longitudinal” as used herein refers to a long dimension of a probe, an end-to-end dimension of the probe, or a tip-to-tip dimension. Longitudinal may refer to a generally straight line that extends from one end of the probe to another end of the probe or it may refer to a curved or stair-stepped path that has a sloped or even changing direction along a height of the probe. When referring to probe arrays, the longitudinal dimension may refer to a particular direction the probes in the array point or extend but it may also simply refer to the overall height of the array that starts at a plane containing a first end, tip, or base of a plurality of probes and extends perpendicular thereto to a plane containing a second end, tip, or top of the probes. The context of use typically makes clear what is meant especially to those of skill in the art. It is intended that the interpretation to be applied to the term herein be as narrow as warranted by the details of the description provided or the context in which the term is used. If, however, no such narrow interpretation is warranted, it is intended that the broadest reasonable scope of interpretation apply.

[0029] The term “lateral” as used herein is related to the term longitudinal. In terms of the stacking of layers, lateral refers to a direction within each layer, or two perpendicular directions within each layer (i.e., one or more directions that lie within a plane of a layer that are substantially perpendicular to the longitudinal direction). When referring to probe arrays laterally generally has a similar meaning in that a lateral dimension is generally a dimension that lies in a plane that is parallel to a plane of the top or bottom of the array (i.e., substantially perpendicular to the longitudinal dimension. When referring to probes themselves, the lateral dimensions may be those that are perpendicular to an overall longitudinal axis of the probe, a local longitudinal axis of theprobe (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] When referring to longitudinal or lateral, the term substantially means within a particular angular orientation of the longitudinal or a lateral direction wherein the angle may be within 1°, within 2°, within 5°, or in some cases within 10° depending on the context.

[0031] Probe and Probe Array Formation Embodiments:

[0032] According to an embodiment of this invention, a method introduces sections, along the height (i.e., longitudinal length) of a probe, with each section provided with different material properties. Varying material properties along the length of a probe or probe preform, an array of simultaneously formed probes or probe preforms, or other structure in a discontinuous or continuous manner may aid in (1) optimizing the tradeoff between contact force (stiffness) and yield stress at a given overtravel, (2) may address the tradeoff between scrub length and contact resistance, (3) may enable the formation of probes with enhanced properties that will enable formation of tighter pitch arrays while meeting contact force and overtravel requirements without exceeding Young’s modulus or yield strength material limitations, and / or (4) allow the simultaneous formation of probes or preforms while in array configurations with required properties and production yields.

[0033] FIGS. 2A - 2E illustrate a first embodiment of a probe array corresponding to a method according to the present invention wherein variations of material properties are provided at different heights along the lengths of probes or probe preforms while the probes or preforms are formed in an array configuration where the shape of the probes or preforms are provided by patterning of a photoresist to provide vertical openings for receiving deposited structural material to form straight probes or probe preforms wherein the probes or preforms are formed with different plating parameters along their lengths to provide different material properties at different heights along those lengths. In the following, reference will be made simply to probes. More particularly, FIGS. 2A - 2E illustrate different stages in the formation of a probe array by a method according to an embodiment of the invention.

[0034] FIG. 2A shows a cut view of a photoresist material 120 or other masking material which has been deposited or applied to a substrate, also indicated as a probe substrate 110 that may or may not be a build substrate, corresponding to an initial step of the method of forming a probe array. FIG. 2B shows a cut view of the photoresist material 120 after formation of openings130 e.g., by exposure and development of the photoresist material 120, which leaves a plurality of pillars 125 of photoresist material, wherein the openings 130 correspond to locations 110A on the probe substrate 1 10 where probes 100 will be formed while in an array pattern desired for the probe array 200 to be obtained.

[0035] In particular, FIG. 2C shows the probe array 200 comprising a plurality of probes 100 realized at locations 110A on the probe substrate 1 10 corresponding to the positions of the opening 130 provided in the photoresist material 120. In particular the probe array 200 is obtained by a step of deposition of a structural material 140 into the openings 130 to form the probes 100, possible planarization of the structural material 140, and removal of the photoresist 120, in particular of the pillars 125. The probes 100 may be held at the location 100A by bonding, for instance.

[0036] Suitably, according to a first embodiment of the invention, variations of material properties of the structural material 140 being the selected material M are provided at different heights along a length L of the probe 100 that comprises first portions 100M2 made of a selected material M, each first portion 100M2 being located within two different second portions 100M1 , also made of the selected material M, the selected material M at the two different second portions 100M1 having an intrinsic material property with a first value k1 being different from a second value k2 of the intrinsic material property of the selected material M at the first portion 100M2. In particular, the intrinsic material property of selected material M is independent of the amount and shape of the same at the first portion 100M2 and at the second portions 100M1 .

[0037] FIG. 2D provides a schematic illustration showing different values k1 , k2 of the intrinsic material property at different heights along the length L of the probe 100 wherein, in this example, the property illustrated is the elastic modulus or Young’s modulus having two different values, in particular a first value k1 and a second value k2 where the first value k1 is greater than the second value k2.

[0038] FIG. 2E provides a graphic representation of a process parameter Pp, e.g., a plating process parameter such as current density versus the process time, in particular the plating time, along with the material property values k1 and k2 that results from the process of deposition or plating. In particular, a lower current density is used for longer periods of time to create the longer length second portions 100M1 of the selected material M having the higher value (k1 ) of the elastic modulus while a shorter plating time at higher current density is used to create shorter length first portions 100M2 of the selected material M having a lower value (k2) of the elastic modulus.

[0039] According to an embodiment of the invention, least two different second portions 100M2 are separated by an amount selected from a group consisting of: (1 ) at least 5 microns, (2) at least 10 microns, (3) at least 20 microns, (4) at least 50 microns, and (5) at least 100 microns.

[0040] Moreover, being the different intrinsic property the elastic modulus of the selected material M, i.e. of the structural material 140, the difference between a first elastic modulus k1 and a second elastic modulus k2 having a value smaller than the first elastic modulus, is selected from a group consisting of: (1) at least 10% of the second elastic modulus k2, (2) at least 20% of the second elastic modulus k2, (3) at least 40% of the second elastic modulus k2, (4) at least 70% of the second elastic modulus k2, (5) at least 100% of the second elastic modulus k2, and (6) at least 140% of the second elastic modulus k2.

[0041] In actual practice, the intrinsic material property, e.g., the elastic module, of the selected material may have more than two different values and be targeted to different positions and heights that provide appropriate probe properties, in particular in relationship to intended deformation locations on the probes 100 and interactions with guide plates or other array structures in the probe array 200.

[0042] FIGS. 2F1 - 2F5 illustrate side views of exemplary probe arrays 200 or preform arrays including a plurality of probes 100 or preforms of the type shown in FIG. 2C, in particular including at least a first portion 100M1 located between two different second portions 100M1 , wherein the probe arrays 200 include different types of retention structures, including for instance guide plates and / or other mounting, alignment and / or retention plates. In the following, reference will be made simply to probes and probe arrays.

[0043] More particularly, FIG. 2F1 shows a plurality of exemplary probes 100 held in an array configuration or pattern by a probe substrate 110, in particular a permanent substrate that may or may not be a build substrate. The probes 100 are held at a plurality of desired locations110A on the probe substrate 1 10, the probe substrate 110 being a retention structure of the probe array 200. FIG. 2F2 shows a plurality of exemplary probes 100 held in an array configuration or pattern by a retention structure comprising a combination of a probe substrate 110, in particular a permanent substrate, and a guide plate 220 provided with a plurality of holes 240, engaging the probes 100 and holding the same at the plurality of desired location 100A on the probe substrate 110. The holes 240 in the guide plate 240 may be laterally shifted relative to the locations 110A on the substrate 110 whereat the probes 100 are bonded.

[0044] Moreover, FIG. 2F3 shows exemplary probes 100 held in an array configuration or pattern by a retention structure comprising a plurality of guide plates, in particular a first guide plate 220A and a second guide plate 220B, provided with respective plurality of holes 240A, 240B which engage and house the probes 100 and that are laterally aligned. FIG. 2F4 shows exemplary probes 100 that have a not straight configuration, either been pre-shaped or shaped by a relative lateral movement of the two guide plates 220A, 220B, in particular of the respective plurality of holes 240A, 240B comprised in the two guide plate 220A, 220B and engaging the probes 100, thepluralities of holes 240A, 240B of the two guide plate 220A, 220B being laterally shifted with respect to one another. In this case, the probes 100 comprise a compliant or spring portion 100E having a preformed shape and being disposed between the two guide plates 220A, 220B. The probe array 200 may also comprise more than two guide plates, each having a respective plurality of holes that engage the probes 100 and that may be laterally aligned or laterally shifted.

[0045] Furthermore, FIG. 2F5 shows a plurality of exemplary probes 100 held in an array configuration or pattern by a retention structure, comprising a thick alignment or retention plate 230 provided with a plurality of retention holes 250. The retention plate 230 has a thickness Th that may be selected from a group consisting of: (1 ) at least1 / 4 of a longitudinal length of the probes 100; (2) at least1 / z of the longitudinal length of the probes ; (3) at least % of the longitudinal length of the probes 100, the longitudinal length L of the probes 100 being the length from the first contact region 100A to the second contact region 100B. As shown in the figure, the thickness Th of the retention plate 230 is the length of the retention holes 250 provided therein.

[0046] According to an embodiment of the invention, the probe array 200 is formed by a method comprising the following steps:(a) forming the plurality of probes 100, comprising:(i) providing the probe substrate 110;(ii) directly or indirectly on the probe substrate 110, providing at least one patterned template 120 with the plurality of openings 130;(iii) providing the structural material 140 into the plurality of openings 130 to form at least a portion of the plurality of probes 100, wherein the providing of the structural material 140 comprises varying intrinsic properties of the structural material 140 at different heights along a length L of the probes 100; and(b) providing at least one probe array retention structure to engage the plurality of probes 100 according to the array pattern desired for the probe array 200.

[0047] According to an embodiment of the invention, variations of material properties of structural material 140 being the selected material M at the first portions 100M2 and second portions 100M1 along the length L of the probe 100 that comprises first portions 100M2 made of a selected material M each located within two different second portions 100M1 are obtained by varying the processing parameters , such as plating parameters as a process operation, in particular a plating operation progresses from bottom to top within the openings 130 in the photoresist material or patterned template 120. Suitably, the plating parameters may be varied in a number of different ways to cause plated structural material 140 forming the probes 100 to have different properties along the probe length L. In this case, the selected material M is the plated structural material 140 that form the probes and has different intrinsic material properties, thatchanges along the probe length L due to variable processing parameters of a process operation realizing the structural material 140, in the example a plating process.

[0048] Plating may occur by one or more of:(1 ) Direct current plating with a current density that is fixed at any given time but is made to change from one value to another in a substantially discontinuous manner to cause relatively abrupt changes in grain size formation of deposited metals and thus changes in yield strength of the deposited structural material 140 at a given height of deposition. Times between current density changes may range from seconds to tens of seconds or even to minutes such that the thickness of the deposited structural material 140 at any given current density ranges from tenths of microns, to microns, to tens of microns.(2) Direct current plating with relatively slow transitions in current density from one value to another, from a local temporal minimum value to a local temporal maximum value, and vice-a-versa, where such transitions may occur over seconds, to tens of seconds, to even minutes uniformly in the transition between values.(3) Pulsed current plating which has a first fast oscillation rate associated with the pulsing but a slower rate of change between changes to one or both of minimum and / or maximum current densities, or even duty cycle, to produce changes in material properties similar to those noted in (1) and (2) above. The fast oscillations may occur with a frequency range of 1 hz to 100 hz, or faster, and a duty cycle ranging from 5% to 95% with material property variations in the resulting deposited structural material 140 occurring based on different frequencies and duties cycles which may deviate from properties resulting from a direct current deposition at a similar averaged current density. Though such high frequency pulsing variations may be used in the some implementations of the present invention, since the variations of primary interest in the present application are those related to different regions of material that are each microns to tens of microns in height, in a preferred embodiment it is the slower rates of rates of change between at least one of maximum current density, minimum current density and even applied duty cycle that may bring the types of changes in material properties of the deposited structural material 140 according to the invention.(4) Reversed pulse plating with slow variations in associated parameters.(5) Plating with variations in bath temperature.(6) Plating with variations in plating bath flow or agitation and / or orientation of a plating surface.

[0049] In some alternatives, in addition to forming the probes or performs from deposited, structural metal or metals, other materials may be co-deposited, selectively coated, or blanket coated over the formed probes or preforms wherein the other materials may include ceramics,nano-fibers, dielectrics, adhesion materials, barrier materials, and / or bonding materials and the like. In some variations, plating may be only partially completed, non-plating processing steps may then occur, and then plating continued wherein the non-plating process may contribute to changes in the properties of the deposited material at different heights of deposition.

[0050] In still other embodiments, the photoresist material or patterned template 120 may take the form of multiple layers with patterning of the photoresist material 120 occurring after formation of each layer, after formation of a portions of the layers, or only after the formation of all of the layers. When performing multiple patterning operations, the patterning used may vary to form openings 130 with shapes other than linear vertical shapes.

[0051] Some of patterning operations may be followed by development operations and possible backfilling operations or such development operations may be delayed until all of the patternings (e.g., exposures) have occurred.

[0052] In some embodiments, properties may be changed in a discontinuous manner while in other embodiments, as shown in FIGS. 5A and 5B, depicting the patterns of the process parameters in time and the stiffness / elastic modulus along the probe length, respectively, properties may be varied in a continuous manner so as to avoid stair-stepped and stress focusing transitions.

[0053] FIGS. 3A - 3E illustrate a second embodiment of a probe array corresponding to an alternative method according to the present invention wherein variations of material properties at different heights along the lengths of probes or probe preforms while the probes or preforms are formed in an array configuration where the shape of the probes or preforms are provided by patterning multiple layers of different photoresist materials or patterned templates 120 to provide vertical openings and then deforming the photoresist materials or patterned templates 120, for instance by using lateral shearing. After deformation, the photoresist materials or patterned templates 120 are developed to reveal the openings 130, or if openings already exist, the process moves to depositing structural material 140 into the openings 130 using at least one or more variations in process parameters along the lengths L of the probes 100 to provide different material properties at different heights along those lengths. In the following, reference will be made simply to probes. More particularly, FIGS. 3A - 3E illustrate different stages in the formation of a probe array by the above alternative method.

[0054] As illustrated, at least some of the layers of photoresist have different stiffnesses such that upon lateral deformation, the photoresist material 120 as a whole inherently provides not only angled openings but openings with different angular orientations at different vertical levels such that upon receiving deposition of the structural material 140, probes 100 are formed withcurves or multiple differently angled segments as well as with different material properties along their lengths L.

[0055] More particularly, FIG. 3A shows a cut view of a photoresist material 120 which has been deposited or applied to a probe substrate 110 and comprises different layers of photoresist material, in particular three layers of photoresist material PH1 , PH2, PH3, have been deposited superimposed one another on the probe substrate 1 10, for instance with a central layer PH2 being stiffer than the lower and upper layers PH1 , PH3. Moreover, FIG. 3B shows a cut view of the photoresist material 120 after formation of a plurality of openings 130 in its layers PH1 , PH2, PH3; suitably, a lateral deformation of the photoresist material 120 is provided, in particular at its central layer PH2, and a development step is performed to realize the plurality of openings 130 in the photoresist material 120. wherein each opening is at a location for a probe 100 to be realized according to an array pattern desired for the probe array 200.

[0056] Furthermore, FIG. 3C shows the probe array 200 wherein the probes 100 have been realized by a step of deposition of a structural material 140 into the openings 130, possible planarization of the structural material 140, and removal of the photoresist material 120. As shown in the figure, due to the lateral deformation of the central layer PH2 of the photoresist material 120 and thus of the openings 130 formed therein, each probe 10 includes two bends or changes in orientation B1 , B2. The probes 100 thus include a compliant or spring portion 100E, extending between the two bends B1 , B2 and having a preformed or inclined shape The photoresist material 120 as a whole provides not only angled openings 130 but openings with different angular orientations at different vertical levels such that curved or multi-angled openings are formed for receiving deposition of the structural material 140 such that probes 100 are formed with curved or multiple differently angled segments.

[0057] Suitably, also according to the second embodiment of the invention, variations of material properties of the structural material 140 are provided at different heights along a length L of the probe 100, in particular along the compliant or spring portion 100E that comprises first portions 100M2, each first portion 1 COM2 being located within two different second portions100M1 , the structural material 140 at the two different second portions 100M1 having an intrinsic material property with a first value k1 being different from a second value k2 of the intrinsic material property at the first portion 100M2, the intrinsic material property being independent of the amount and shape of the same.

[0058] FIG. 3D provides a schematic illustration showing different values k1 , k2 of the intrinsic material property at different heights along the length L of the probe 100 wherein, in this example, the property illustrated is the elastic modulus or Young’s modulus having two different values k1 and k2 where k1 is greater than k2.

[0059] FIG. 3E provides a graphic representation of a processing parameter Pp, e.g., a plating process parameter such as the current density, versus the processing time, in particular the plating time, along with the material property values k1 , k2 that results from the process of deposition or plating wherein a lower current density is used for longer periods of time to create the longer length second portions 100M2 of the structural material 140 having the higher value (k1) of the elastic modulus while a shorter plating time at higher current density is used to create shorter length first portions 100M2 of the structural material 140 having a lower value (k2) of the elastic modulus.

[0060] In actual practice, the intrinsic material property, e.g., the elastic module, of the structural material 140 may have more than two different values and be targeted to different positions and heights that provide appropriate probe properties, in particular in relationship to intended deformation locations on the probes 100 and interactions with guide plates or other array structures in the probe array 200.

[0061] The order of operations performed on the photoresist material 120 as shown in FIGS. 3A-3C may vary, for example, exposure of the different layers of the photoresist material 120 may occur after each is formed or it may occur in as a single exposure after all layers are formed. In some implementations, the photoresist layers may be exposed, then deformation may occur and then development may occur, or alternatively, the photoresist layers may be exposed followed by development and then by deformation. In still other variations, the deposition of the structural material 140 may occur prior to deformation of the obtained structure.

[0062] FIGS. 3F1 - 3F4 illustrate side views of exemplary probe arrays 200 including probes of the type shown in FIG. 30, each having a compliant or spring portion 100E having a preformed shape and being made by a structural material 140 having variable material properties along the length L of the probes 100, wherein the probe arrays 200 include different types of retention structures, including for instance guide plate and / or mounting, alignment and / or retention plates.

[0063] More particularly, FIG. 3F1 shows a plurality of exemplary probes 100 held in an array configuration or pattern by a probe substrate 100, in particular a permanent substrate, that may or may not be a build substrate. The probes 100 are held at a plurality of desired locations110A on the probe substrate 1 10, the probe substrate 110 being a retention structure of the probe array 200. FIG. 3F2 shows a plurality of exemplary probes 100 held in an array configuration or pattern by a retention structure comprising a combination of a probe substrate 110 and a guide plate 220 provided with a plurality of holes 240, engaging the probes 100 and holding the same at the plurality of desired location 100A on the probe substrate 110. The holes 240 in the guide plate240 may be laterally shifted relative to the locations 1 10A on the substrate 110 whereat the probes 100 are bonded.

[0064] Moreover, FIG. 3F3 shows exemplary probes 100 held in an array configuration or pattern by a retention structure comprising a plurality of guide plates, in particular a first guide plate 220A and a second guide plate 220B, provided with respective plurality of holes 240A, 240B which engage and house the probes 100 being laterally shifted with respect to one another according to the preformed shape of the compliant or spring portion 100E of the probes 100. FIG. 3F4 shows exemplary probes that have been further inclined by a relative lateral movement of the two guide plates 220A, 220B; in particular, the two guide plates 220A, 220B have respective holes 240A, 240B that are further laterally shifted with respect to one another starting from the shape of the compliant or spring portion 100E to further incline such a compliant or spring portion 100E with respect to its initial configuration.. The probe array 200 may also comprise more than two guide plates, each having a respective plurality of holes that engage the probes 100 and that laterally shifted according to the lateral inclination of the compliant or spring portion 100E of the probes 100.

[0065] Multiple variations of the embodiment of FIGS. 3A - 3F4 are possible and include for example: (1 ) use of different numbers of template deformation levels, (2) use of deformation tools that control bending of the template at different levels regardless of whether or not distinct stiffnesses exist, (3) different numbers and locations of material property variations may be induced in the plated probes, (4) arrays may be linear in configuration or they may be two-dimensional, (5) probe counts, probe spacings, probe diameters, probe heights, probe configurations, and / or probe pitch may be different and may be uniform or non-uniform.

[0066] The method of forming the probe array 200 according to the above alternative embodiments comprises a step of providing the patterned template 120 by superimposing a plurality of layers of photoresist PH1 , PH2, PH3 directly or indirectly on the probe substrate 110 and forming the plurality of openings 130 as well as a step of deforming at least one of the plurality of layers of photoresist PH1 , PH2, PH3, in particular the central layer PH2, before or after the formation of the openings 130.

[0067] FIGS. 4A - 4E illustrate a third embodiment of the probe array corresponding to a further alternative method according to the present invention that may provide varying of material properties along the lengths of probes being formed while in array configurations or simply provide unique probe configurations, in particular configurations that may not be readily obtainable from multi-layer formation or deformation based methods, where the probes 100 have a shape based on use of multi-photon lithography to provide patterning of a photoresist material 120 which may be developed to provide shaped openings 130 of desired configurations for receiving depositedstructural material 140 to provide probes 100 of desired configurations (e.g. fixed or varying cross- sectional widths, curvatures, bends, and the like) and the probes 100 may be formed with different material properties along their lengths L based variations in process parameters, in particular a plating process of the shaped openings 130 provided in the photoresist material 120 thank to the multi-photon lithography at a plurality of locations 110A on the probe substrate 110 corresponding to an array configuration or pattern desired for the probe array 200 to be obtained.

[0068] More particularly, FIG. 4A shows a cut view of a photoresist material 120 which has been deposited or applied to a probe substrate 110 and is subjected to a multi-photon lithography and developed so that a plurality of shaped openings 130 are formed at locations 100A on the probe substrate 1 10, according to an array pattern desired for the probe array 200, as shown in FIG. 4B. FIG. 4C shows the probe array 200 wherein the probes 100 have been realized by a step of deposition of a structural material 140 (alone or in conjunction with co-deposition of other materials such as ceramics, nano-fibers, and the like) into the shaped openings 130, possible planarization of the structural material 140, and removal of the photoresist material 120, the probes 100 having a same shaped configuration as the shaped openings 130. Suitably, also according to this embodiment of the invention, variations of material properties of the structural material 140 are provided at different heights along a length L of the probe 100, as shown in FIGS. 4D and 4E, for instance as a process operation such as a plating operation, progresses from bottom to top within the openings in the photoresist, the plating parameters may be varied to cause plated structural material to have different properties along the probe length.

[0069] FIGS. 4F1 - 4F4 illustrate side views of exemplary probe arrays 200 including probes 100 of the type shown in FIG. 4G wherein the probe arrays 200 include different types of retention structures, including for instance guide plate and / or mounting, alignment and / or retention plates. More particularly, FIG. 4F1 shows a plurality of exemplary probes 100 held in an array configuration or pattern by a probe substrate 110, in particular a permanent substrate that may or may not be a build substrate, the probes 100 are held at a plurality of desired locations 110A on the probe substrate 110, being the retention structure of the probe array 200. FIG. 4F2 shows a plurality of exemplary probes 100 held in an array configuration or pattern by a retention structure comprising a combination of a probe substrate 110 and a guide plate 220 provided with a plurality of holes 240, engaging the probes 100 and holding the same at the plurality of desired location 100A on the probe substrate 1 10. The holes 240 in the guide plate 240 may be laterally shifted relative to the locations 110A on the substrate 110 corresponding to the shaped configuration of the probes 100. FIG. 4F3 shows exemplary probes held in an array configuration or pattern by a retention structure comprising a plurality of guide plates, in particular a first guide plate 220A and a second guide plate 220B, provided with respective plurality of holes 240A, 240B which engage andhouse the probes 100 being laterally shifted with respect to one another according to the preformed shape of the probes 100. FIG. 4F4 shows exemplary probes 100 that have been further inclined by relative lateral movement of the two guide plates 220A, 220B. The probe array 200 may also comprise more than two guide plates, each having a respective plurality of holes that engage the probes 100 and that laterally shifted according to the shape of the probes 100.

[0070] The method of forming the probe array 200 according to the above alternative embodiments comprises a step of using of multi-photon lithography to provide patterning of a photoresist material 120, which may be developed to provide shaped openings 130 of desired configurations for receiving deposited structural material 140 to provide probes 100 of desired configurations (e.g., fixed or varying cross-sectional widths, curvatures, bends, and the like).

[0071] In other alternative embodiments, in addition to multi-photon patterning, deformation-based patterning, more traditional lithography, laser machining, and / or the like may also be used particularly when the complexity of probe configurations or overlap in adjacent probe deposition regions prohibits effective multi-photon exposure to completely provide a desired level of patterning. In some variations, the multi-photon patterning of openings may provide not only desired curvature to the probes or differently oriented segments to the probes but also different cross-sectional widths to the probes at different heights as exemplified in FIG. 6. In particular, FIG. 6 shows how multiphoton lithography can be used to provide a local variation in material shape of a plating template, that can in turn be used to produce complex probe configurations, such as a probe 100 that have a continuous variation in a local diameter D1 , D2, D3, or other structure in a vertical build direction.

[0072] After the depositing of the structural material in the above examples, the photoresist or patterning material is generally removed to reveal the array of probes that has been formed. In some variations, only a portion of the photoresist or patterning material may be removed as it may be desirable to use a portion of the photoresist or other patterning material as a permanent attachment support for the probes of the array, as a temporary support to the probes of the array until transfer of the probes to a permanent substrate is completed, or as a supplemental elastic enhancement to probes or as a barrier material against probe to probe shorting. In still other variations the patterning and deposition of structural material may not provide completed probes but only partially completed probes, or probe preforms, that may be subjected to additional processing to complete the formation of the probes (e.g., including the addition of tip material, addition dielectric barrier material, addition of a bonding material or bonding enhancement material. In still other embodiments, the probe arrays of FIGS. 2A - 4F4 may require assembly to form full arrays prior to putting the combined arrays to use.

[0073] In some variations, the variation in probe material properties introduced in the probe may be periodic in nature or aperiodic. The introduction of material properties changes may be made to occur with particular geometric configurations of the probes (e.g., in straight regions, in selected curved regions, in regions of expanded or narrowed cross-sectional width, and the like).In still other variations, no variation in material properties may be necessary if the multi-photon lithography alone, or in combination with other patterning techniques, can provide desired probe attributes by geometric configuration variations alone.

[0074] In some embodiments, where multiphoton lithography is performed to provide local probe diameters that vary in cross-section, or even in more complex configurations (e.g., multibeam probes) wherein the variations may form continuous or uniform transitions by controlling and smoothly varying the volume of the photon interplay that occurs by stair-step transitions.

[0075] The methods of the present invention may provide in-situ modulation of mechanical properties along the lengths of probes and, in particular, along the lengths of probes being formed while in array configurations. In situations where probes within an array have the same configurations, the in-situ process changes can result in the same mechanical property modulations on all of the probes at the same vertical (i.e., longitudinal heights) assuming uniform distribution of plating current and plating material density. In situations where some probes may have different cross-sectional configurations at different heights relative to other probes, it may be necessary to provide some plating inhibition for some openings or to provide modulated current density in different areas if property modulation is to remain at constant height levels throughout the lateral spread of the array. In other embodiments, where it is desirable to have different properties at different heights for some probes compared to other probes, masking techniques or modulated current densities, or other modulated plating parameters may be laterally controlled to provide such variation.

[0076] The methods of the present invention may be used to modulate a desired mechanical property within a certain range in continuous fashion (for example, the elastic modulus may be modulated from between, for example, 50 - 300Gpa, e.g., 85 - 210 Gpa for Nickel). Properties to be varied may include young’s modulus, yield strength, modulus of resilience, electrical resistance, or other properties.

[0077] Some beneficial results of the property modulation techniques set forth herein may include, for example: (1 ) regardless of how the probes are initially formed (straight probes, shaped probes by multiphoton lithography, deformed template, and / or by plastic deformation), by introducing “weaker” or “softer” sections along the height of the probe, certain deformed shapes under a certain force can be tailored to enable: (a) alternative tip “rocking” motion for desired contact scrub motion, and thereby enabling improved contact performance at a given contact force(e.g. less contact resistance), (b) modification of scrub length (e.g. to shorten it) by reducing the lateral motion force during a given overtravel, and / or (c) by forcing preferential deformation at certain segments along the length of a given probe, high stress and failure prone sections of a probe may be avoided which could be accomplished, for example by: (i) modulating the elastic properties along the height of a probe, (ii) modulating the cross section of a probe, or (iii) a combination of the two.

[0078] Variations of the above embodiments are possible. In some such variations, single structures or multiple structures with different configurations may be formed (e.g., formation of multiple probes that are not in an array configuration). In some embodiments, the deposited material may be planarized alone or in combination with the photoresist while in other embodiments, the photoresist may be replaced with a different material (e.g., a sacrificial material) prior to such planarization occurring. In other embodiments, planarization need not occur.

[0079] In other alternatives, a single deposition of material made with varying parameters may form only a portion of a structure as opposed to forming it from bottom to top while additional depositions, with or without additional plating templates, may be used to form additional portions of a structure. In such alternatives, additional portions of the structure may be added or attached to the initial layer in any appropriate manner. For example, one or more additional portions of the structure may be formed by forming one or more additional layers on the already formed layer. The formation of the additional layers may involve the use of the same or different structural materials, repeated use of the same cross-sectional configuration or different cross-sectional configurations, use of the same formation process or use of different formation processes. In some embodiments, dielectrics may form part of the structures. In some embodiments, metal deposition may occur by a process other than electrodeposition (e.g., electroless deposition, vacuum or vapor deposition, and the like).

[0080] In some alternatives, the photoresist may be replaced with a different material prior to depositing structural material. In some alternatives, the structure(s) may be formed on a permanent substrate (i.e., a substrate that will be included in the final product, e.g., a space transformer) or on a temporary substrate with a sacrificial layer or release layer or simply on a sacrificial substrate. In some alternatives, the initial layer as illustrated might actually be something other than a first layer. In some variations, one dimensional array may be provided, such as 1 x N arrays, or two-dimensional arrays may be provided, such as N x M arrays.

[0081] The techniques used herein may also be used to set preferential bending locations when final probe configuration is to be set by lateral or longitudinal plastic deformation of deposited probe material.

[0082] Numerous variations of the methods taught here are possible and will be apparent to those of skill in the art upon review of the teachings herein. In some embodiment variations, the regions to which different plating parameters are applied may be limited to different portions of the compliant or spring regions of the probes while in other embodiment variations, different plating parameters may be applied to other portions of the probes.

[0083] Further Comments and Conclusions

[0084] Various other embodiments of the present invention exist. Some of these embodiments may be based on a combination of the teachings herein with various known teachings.

[0085] Some fabrication embodiments may not use any blanket deposition process. Some embodiments may use selective deposition processes or blanket deposition processes on some layers that are not electrodeposition processes. Some embodiments may use nickel or nickelcobalt as a structural material while other embodiments may use different materials. For example, preferred spring materials include nickel (Ni), copper (Cu), beryllium copper (BeCu), nickel phosphorous (Ni-P), tungsten (W), aluminum copper (Al-Cu), steel, P7 alloy, palladium, palladiumcobalt, silver, molybdenum, manganese, brass, chrome, chromium copper (Cr-Cu), and combinations of these. Some embodiments may use copper as the structural material with or without a sacrificial material. Some embodiments, for example, may use nickel, nickelphosphorous, nickel-cobalt, palladium, palladium-cobalt, gold, copper, tin, silver, zinc, solder, rhodium, rhenium as structural materials while other embodiments may use different materials. Some embodiments, for example, may use copper, tin, zinc, solder or other materials as sacrificial materials. Some embodiments may use different structural materials on different layers or on different portions of single layers. Some embodiments may remove a sacrificial material while other embodiments may not. Some embodiments may use photoresist, polyimide, glass, ceramics, other polymers, and the like as dielectric structural materials.

[0086] Structural or sacrificial dielectric materials may be incorporated into embodiments of the present invention in a variety of different ways. Such materials may form a third material or higher deposited material on selected layers or may form one of the first two materials deposited on some layers.

[0087] Some embodiments may employ diffusion bonding or the like to enhance adhesion between successive layers of material.

[0088] It will be understood by those of skill in the art that additional operations may be used in variations of the above presented method of making embodiments. These additional operations may, for example, perform cleaning functions (e.g., they may perform activation functions and monitoring functions, and the like.

[0089] 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.

[0090] Though various portions of this specification have been provided with headers, it is not intended that the headers be used to limit the application of teachings found in one portion of the specification from applying to other portions of the specification. For example, alternatives acknowledged in association with one embodiment, are intended to apply to all embodiments to the extent that the features of the different embodiments make such applications functional and do not otherwise contradict or remove all benefits of the adopted embodiment. Various other embodiments of the present invention exist. Some of these embodiments may be based on a combination of the teachings set forth herein with various known teachings.

[0091] 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.

[0092] 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

CLAIMSWhat is claimed is:1 . A probe array (200), comprising:(a) a plurality of probes (100), comprising:(i) an elastically deformable body portion (100C) having a first end (100C1) and a second end (100C2);(ii) a first contact region (100A) connected directly or indirectly to the first end (100C1 ) of the elastically deformable body portion (100C); and(iii) a second contact region (100B) connected directly or indirectly to the second end (100C2) of the elastically deformable body portion (100C), wherein multiple probes of the plurality of probes (100) comprise at least one first portion (100M2) made of at least one selected material (M) located within at least two different second portions (100M1) along a length (L) of each of the multiple probes (100) wherein the at least one selected material (M) at the at least two different second portions (100M1) has at least one intrinsic material property having a first value (k1) being different from a second value (k2) of the intrinsic material property of the at least one selected material (M) at the at least one first portion (100M2), the at least one selected material (M) being the structural material (140) forming at least a portion of the probes (100); and(b) at least one retention structure holding the plurality of probes (100) in an array pattern desired for the probe array (200).

2. The probe array of claim 1 , wherein the intrinsic material property of the at least one selected material (M) is independent of the amount of the selected material (M) and the shape of the selected material present at the first portion (100M2) and at the second portions (100M1 ).

3. The probe array of claim 1 , wherein the intrinsic material property of the at least one selected material (M) has a plurality of values at a plurality of different portions of each of the multiple probes (100).

4. The probe array of claim 1 , wherein the intrinsic material property of the at least one selected material (M) is selected from a group consisting of: yield strength, elastic modulus or Young’s modulus, modulus of resilience and electrical resistance.

5. The probe array of claim 4, wherein the intrinsic material property of the at least one selected material (M) is the elastic modulus and the difference between a first elastic modulus (k1) and a second elastic modulus (k2) having a value smaller than the first elastic modulus, is selected from a group consisting of: (1) at least 10% of the second elastic modulus (k2), (2) at least 20% of the second elastic modulus (k2), (3) at least 40% of the second elastic modulus (k2), (4) at least 70% of the second elastic modulus (k2), (5) at least 100% of the second elastic modulus (k2), and (6) at least 140% of the second elastic modulus (k2).

6. The probe array of claim 1 , wherein at least two different second portions (100M2) are separated by an amount selected from a group consisting of: (1) at least 5 microns, (2) at least 10 microns, (3) at least 20 microns, (4) at least 50 microns, and (5) at least 100 microns.

7. The probe array of claim 1 , wherein the at least one probe array retention structure is selected from a group consisting of:(i) a substrate (1 10) to which the first contact regions (100A) of the probes (100) are bonded at a plurality of bonding locations (110A);(ii) a substrate (1 10) to which the first contact regions (100A) of the probes (100) are bonded at a plurality of bonding locations (110A) along with at least one guide plate (220) having a plurality of holes (240) which engage the probes (100);(iii) a substrate (1 10) to which the first contact regions (100A) of the probes (100) are bonded at a plurality of bonding locations (110A) along with at least one guide plate (220) having a plurality of holes (240) which engage the probes (100) wherein the holes (240) in at least one guide plate (220) are laterally shifted relative to the bonding locations (110A) on the substrate (110);(iv) a plurality of guide plates (220A, 220B) each having a respective plurality of holes (240A, 240B) which engage the probes (100);(v) a plurality of guide plates (220A), 220B) each having a respective plurality of holes (240A, 240B) which engage the probes (100), wherein at least two of the plurality of guide plates (220A, 220B) have respective holes (240A, 240B) that engage probes that are laterally aligned;(vi) a plurality of guide plates (220A, 220B) each having a respective plurality of holes (240A, 240B) which engage the probes (100), wherein at least two of the plurality of guide plates (220A, 220B) have respective holes (240A, 240B) that engage probes that are laterally shifted with respect to one another; and(vii) a retention plate (230) provided with a plurality of retention holes (250) into which the probes (100) are inserted.

8. The probe array (200) of claim 5, wherein the at least one retention structure is a retention plate (230) which has thickness (Th) selected from a group consisting of: (1 ) at least % of a longitudinal length of the probes (100); (2) at least1 / 2 of a longitudinal length of the probes (100); and (3) at least % of a longitudinal length of the probes (100), the longitudinal length of the probes (100) extending from the first contact region (100A) to the second contact region (100B).

9. The probe array of claim 1 , wherein each of a plurality of the probes comprises a plurality of adhered layers.

10. The probe of claim 1 wherein the first contact region (110A) is configured for a function selected from a group consisting of: (1 ) making temporary pressure based electrical contact to a first electronic component upon elastically biasing the elastically deformable body portion (100C) with the first contact region (100A) against the first electronic component, and (2) bonding to the first electronic component for making permanent contact.11 . The probe array of claim 10 wherein the first contact region (100A) of each of a plurality of probe (100) is configured for bonding to the first electronic component for making permanent contact.

12. The probe array of claim 10 wherein the first contact region (100A) of each of a plurality of probes (100) is configured for making temporary contact.

13. The probe of claim 10 wherein the second contact region (100B) is configured for making temporary pressure based electrical contact to a second electronic component upon elastically biasing the elastically deformable body portion (100C) with the second contact region (100B) against the second electronic component.

14. The probe array of claim 1 wherein the first portion (100M2) and at least one of the two different portions (100M1 ) of the multiple probes (100) form a compliant or spring portion (100E) of each probe (100).

15. The probe array of claim 14 wherein the compliant or spring portion (100E) of a probe (100) has a preformed shape.

16. The probe array of claim 14 wherein the compliant or spring portion (100E) of a probe (100) has an inclined shape extending between at least two bends (B1 , B2) along the length (L) of the probe (100).

17. The probe array of claim 14 wherein the compliant or spring portion (100E) of a probe (100) has a curved or multi-angled shape comprising a plurality of curved or angled segments.

18. The probe array of claim 15 wherein the at least one probe array retention structure comprises a plurality of guide plates (220A, 220B) each having a respective plurality of holes (240A, 240B) which engage the probes (100), wherein at least two of the plurality of guide plates (220A, 220B) have respective holes (240A, 240B) that engage probes that are further laterally shifted with respect to one another starting from the shape of the compliant or spring portion (100E) to further incline the compliant or spring portion (100E) with respect to its initial configuration.

19. The probe array of claim 1 wherein the probes (100) further comprise additional materials being co-deposited, selectively coated, or blanket coated over the formed probes.

20. A method of forming a probe array (200), comprising:(a) forming a plurality of probes (100), comprising:(i) providing a probe substrate (110);(ii) directly or indirectly on the probe substrate (110), providing at least one patterned template (120) with a plurality of openings (130);(iii) providing a structural material (140) into the plurality of openings (130) to form at least a portion of the plurality of probes (100), wherein the providing of the structural material (140) comprises varying intrinsic properties (k1 , k2) of the structural material (140) at different heights along a length (L) of the probes (100); and(b) providing at least one probe array retention structure to engage the plurality of probes (100) according to an array pattern desired for the probe array (200).21 . The method of claim 20, wherein varying intrinsic properties (k1 , k2) of the structural material (140) comprises varying processing parameters of a process operation forming the structural material (140) as the process operation progresses from bottom to top within the plurality of openings (130) in the patterned template (120).

22. The method of claim 21 , wherein the process parameters are varied in a continuous manner.

23. The method of claim 1 1 , wherein providing at least one patterned template (120) comprises providing a plurality of layers of photoresist (PH1 , PH2, PH3) directly or indirectly on the probe substrate (110) wherein the plurality of openings (130) are formed.

24. The method of claim 23, further comprises a step of deforming at least one (PH2) of the plurality of layers of photoresist (PH1 , PH2, PH3), before or after the formation of the openings (130).

25. The method of claim 1 1 , wherein the process operation forming the structural material (140) comprises a plating operation.

26. The method of claim 25, wherein the plating operation is chosen in a group consisting of:(1 ) direct current plating with a current density that is fixed at any given time and is made to change from one value to another in a substantially discontinuous manner to cause relatively abrupt changes in grain size formation of deposited metals and changes in a process parameter being a yield strength of the deposited structural material (140) at a given height of deposition, wherein times between current density changes range from seconds to tens of seconds or even to minutes and the thickness of the deposited structural material (140) at any given current density ranges from tenths of microns, to microns, to tens of microns;(2) direct current plating with relatively slow transitions in current density from one value to another, from a local temporal minimum value to a local temporal maximum value, and vice-a-versa, where such transitions occur over seconds, to tens of seconds, to even minutes uniformly in the transition between values;(3) pulsed current plating which has a first fast oscillation rate associated with the pulsing and a slower rate of change between changes to one or both of minimum and / or maximum current densities, or a duty cycle, to produce changes in material properties, wherein thefast oscillations occur with a frequency range of 1 hz to 100 hz, or faster, and a duty cycle ranging from 5% to 95% with material property variations in the resulting deposited structural material (140) occurring based on different frequencies and duties cycles which deviate from properties resulting from a direct current deposition at a similar averaged current density;(4) reversed pulse plating with slow variations in associated parameters;(5) plating with variations in bath temperature; and(6) plating with variations in plating bath flow or agitation and / or orientation of a plating surface.

27. The method of claim 20, wherein each probe (100) is provided as comprising at least one first portion (100M2) and at least two different second portions (100M1 ), the at least one first portion (100M2) being located within at least two different second portions (100M1 ), the structural material (140) at the two different second portions (100M1 ) having an intrinsic property with a first value (k1) being different from a second value (k2) of the intrinsic property of the structural material (140) at the at least one first portion (100M2).

26. The method of claim 20, wherein providing at least one patterned template (120) with a plurality of openings (130) comprises superimposing a plurality of layers of photoresist (PH1 , PH2, PH3) directly or indirectly on the probe substrate (110) and forming the plurality of openings (130) in the plurality of layers of photoresist (PH1 , PH2, PH3).

27. The method of claim 26, further comprising a step of deforming at least one of the plurality of layers of photoresist (PH1 , PH2, PH3), before or after the formation of the openings (130).

28. The method of claim 20, wherein providing at least one patterned template (120) with a plurality of openings (130) comprises using multiphoton lithography to pattern a photolithographic material and exposing the same to form the plurality of openings (130).

29. The method of claim 28, wherein the multiphoton lithography patterns the photolithographic material so to form a plurality of shaped openings (130) of desired configurations for receiving deposited structural material (140) to provide probes (100) of desired configurations.

30. The method of claim 28, wherein the multiphoton lithography provides probes (100) having a continuous variation in a local diameter (D1 , D2, D3).31 . The method of claim 20, further comprising one or more of the steps in a group consisting of:(1 ) removing the patterned template (12);(2) removing at least a portion of patterned template (120) and using a remaining portion of the patterned template for a function selected from a group consisting of: (a) permanent attachment support for the probes (100), (b) temporary support to the probes (100) until transfer to a permanent substrate is completed, (c) supplemental elastic enhancement to the probes (100); and (d) barrier material against probe to probe shorting;(3) providing other patterning material for a function selected from a group consisting of: (a) permanent attachment support for the probes (100), (b) temporary support to the probes (100) until transfer to a permanent substrate is completed, (c) supplemental elastic enhancement to the probes (100); and (d) barrier material against probe to probe shorting;(4) planarizing the deposited structural material (140);(5) adding a material to the probes (100) chosen in a group consisting of: (a) a tip material, (b) a dielectric barrier material, (c) a bonding material and (d) an enhancement bonding material;(6) co-depositing, selectively coating, or blanket coating over the formed probes (100) other materials chosen in a group consisting of: ceramics, nano-fibers, dielectrics, adhesion materials, barrier materials, and / or bonding materials and the like.

32. The method of claim 20, wherein providing at least one probe array retention structure is chosen in a group consisting of:(i) bonding the first contact region (100A) of the probes (100) at a plurality of boding location (210A) of the array substrate (220), wherein the array substrate (220) comprises the probe substrate (110) being a build substrate; and(ii) bonding the first contact regions (100A) of the probes (100) at a plurality of boding location (210A) of the array substrate (220), wherein the array substrate (220) and the probe substrate (110) being a build substrate are different.

33. The method of claim 32, further comprising a step chosen in a group consisting of:(iii) providing at least one guide plate (220) having a plurality of holes (240) that engage the probes (100);(iv) providing at least one guide plate (220) having a plurality of holes (240) and inserting the probes (100) into the plurality of holes (240) that are laterally aligned with bonding locations (110A) on the substrate (110);(vi) providing at least one guide plate (220) having a plurality of holes (240) and inserting the probes (100) into the plurality of holes (240), and laterally shifting the at least one guide plate (220) and the substrate (1 10) so that the plurality of holes (240) in the at least one guide plate (220) are laterally shifted with respect to bonding locations (110A) on the substrate (1 10);(vii) providing a plurality of guide plates (220A, 220B), each having a plurality of holes (240A, 240B) which engage the probes (100);(viii) providing a plurality of guide plates (220A, 220B), each having a plurality of holes (240A, 240B) which engage the probes (100), wherein at least one of the plurality of guide plates (220A, 220B) has a plurality of holes (240A, 240B) engaging probes that are laterally aligned;(ix) providing a plurality of guide plates (220A, 220B), each having a plurality of holes (240A, 240B) which engage the probes (100), wherein at least two of the plurality of guide plates (220A, 220B) have respective plurality of holes (240A, 240B) engaging probes that are laterally aligned with respect to one another;(ix) providing a plurality of guide plates (220A, 220B), each having a plurality of holes (240A, 240B) which engage the probes (100), wherein at least two of the plurality of guide plates (220A, 220B) have respective plurality of holes (240A, 240B) engaging probes that are laterally shifted with respect to one another;(x) providing a plurality of guide plates (220A, 220B), each having a plurality of holes (240A, 240B) which engage the probes (100), wherein at least two of the plurality of guide plates (220A, 220B) have respective plurality of holes (240A, 240B) engaging probes that are laterally shifted with respect to one another according to an initial shaped configuration of the probes (100) and further laterally shifted to further incline the probes (100);(xi) providing a retention plate (230) with a plurality of retention holes (250) for receiving probes and inserting the probes (100) into the plurality of retention holes (250); and(xi) providing a retention plate (230) with a plurality of retention holes (250) for receiving probes and inserting the probes (100) into the plurality of retention holes (250), wherein the retention plate (230) has a thickness (Th) selected from a group consisting of: (1 ) at least1, of a longitudinal length of the probes (100); (2) at least1 / z of a longitudinal length of the probes (100); and (3) at least % of a longitudinal length of the probes (100), the longitudinal length of the probes(100) being a length from the first contact region (100A) to the second contact region (100B) thereof.

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