Multi-beam vertical probes with independent compliant arms formed of materials having different yield strengths and corresponding two dimensional probe array

Abstract

Vertical probes (901, 1001, 1101, 1201, 1301, 1301P, 1401, 1501), formed of at least one layer that longitudinally includes a first and a second end and a central portion, with the central portion including at least three compliant arms wherein each of the two outer arms (931A, 931B, …, 1531A, 1531B) include a first material having a first yield strength and the intermediate arm (921, …, 1521) is formed of a second material having a second yield strength less than the first yield strength.

Description

SPECIFICATIONTitle: Multi-beam vertical probes with independent compliant arms formed of materials having different yield strengths and corresponding two dimensional probe arrayField of the Invention:

[0001] The present disclosure relates generally to the field of probes for testing electronic devices (e.g. semiconductor devices) and more particularly to multi-beam (or multi-arm) vertical probes, and it relates to electrochemically fabricating such probes as multi-layer three dimensional (e.g. microscale or meso-scale) structures where each layer is formed from a plurality of deposited materials.Background of the Invention:Probes:

[0002] Probes of various types have been fabricated and used, or have been proposed for use, in the testing of semiconductors devices at both the wafer and packaged level. As the semiconductor industry continues to drive integrated circuit complexity up and size down (more transistors per unit area), a need exists for new and improved probe designs for contacting such devices for testing purposes and / or for making permanent contact with such devices. This need drives probes to smaller sizes (smaller X and Z cross-sectional dimensions and sometimes to shorter lengths, or longitudinal dimensions, in Y), lower contact force, less scrubbing or more controlled scrubbing, while still maintaining high current carrying capacity so that shorts in failed semiconductor devices do not damage the probes. A need exists for improved probes that can meet the new challenges that that semiconductor industry advancements are driving.

[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.Multi-Layer, Multi-Material Electrochemical Fabrication:

[0004] An electrochemical fabrication technique for forming three-dimensional structures from a plurality of adhered layers is being commercially pursued by Microfabricalnc. (formerly MEMGen Corporation) ofVan Nuys, California under the process names EFAB™andMICA FREEFORM®.

[0005] Various electrochemical fabrication techniques are known. Some embodiments ofthe known electrochemical fabrication technique allow the selective deposition of a material using a mask that includes a patterned conformable material on a support structure that is independent of the substrate onto which plating will occur. When desiring to perform electrodeposition using the mask, the conformable portion of the mask is brought into contact with a substrate, but not adhered or bonded to the substrate, while in the presence of a plating solution such that the contact of the conformable portion of the mask to the substrate inhibits deposition at selected locations. For convenience, these masks might be generically called conformable contact masks; the masking technique may be generically called a conformable contact mask plating process. More specifically, in the terminology of Microfabrica Inc.such maskshave come to be known as INSTANT MASKS™ and the process known as INSTANT MASKING™ or INSTANT MASK™ plating. Selective depositions using conformable contact mask plating may be used to form single selective deposits of material or may be used in a process to form multi-layer structures.

[0006] An electrochemical deposition process for forming multilayer structures may be carried out in a number of different ways. In one form, this process involves the execution of three separate operations during the formation of each layer of the structure that is to be formed:1. Selectively depositing at least one material by electrodeposition upon one or more desired regions of a substrate. Typically this material is either a structural material or a sacrificial material.2. Then, blanket depositing at least one additional material by electrodeposition so that the additional deposit covers both the regions that were previously selectively deposited onto, and the regions of the substrate that did not receive any previously applied selective depositions. Typically this material is the other of a structural material or a sacrificial material.3. Finally, planarizing the materials deposited during the first and second operations to produce a smoothed surface of a first layer of desired thickness having at least one region containing the at least one material and at least one region containing at least the one additional material.

[0007] After formation of the first layer, one or more additional layers may be formed adjacent to an immediately preceding layer and adhered to the smoothed surface of that preceding layer. These additional layers are formed by repeating the first through third operations one or more times wherein the formation of each subsequent layer treats the previously formed layers and the initial substrate as a new and thickening substrate.

[0008] Once the formation of all layers has been completed, at least a portion of at least one of the materials deposited is generally removed by an etching process to expose or release the three- dimensional structure that was intended to be formed. The removed material is a sacrificial material while the material that forms part of the desired structure is a structural material.

[0009] One method of performing the selective electrodeposition involved in the first operation is by conformable contact mask plating. In this type of plating, one or more conformable contact (CC) masks are first formed. The CC masks include a support structure onto which a patterned conformable dielectric material is adhered or formed. The conformable material for each mask is shaped in accordance with a particular cross-section of material to be plated (the pattern of conformable material is complementary to the pattern of material to be deposited). In such a process, at least one CC mask is used for each unique cross-sectional partem that is to be plated.

[0010] The support for a CC mask may be a plate-like structure formed of a metal that is to be selectively electroplated and from which material to be plated will be dissolved. In this typical approach, the support will act as an anode in an electroplating process. In an alternative approach, the support may instead be a porous or otherwise perforated material through which deposition material will pass duringan electroplating operation on its way from a distal anode to a deposition surface. In either approach, it is possible for multiple CC masks to share a common support, i.e. the patterns of conformable dielectric material for plating multiple layers of material may be located in different areas of a single support structure. When a single support structure contains multiple plating patterns, the entire structure is referred to as the CC mask while the individual plating masks may be referred to as “submasks”. In the present application such a distinction will be made only when relevant to a specific point being made.

[0011] In some implementations, a single structure, part or device may be formed during execution of the above noted steps. In other implementations (i. e. batch processes), multiple identical or different structures, parts, or devices, may be built up simultaneously.

[0012] In preparation for performing the selective deposition of the first operation, the conformable portion of the CC mask is placed in registration with and pressed against a selected portion of (1) the substrate, (2) a previously formed layer, or (3) a previously deposited material forming a portion of the given layer that is being created. The pressing together of the CC mask and relevant substrate, layer, or material occurs in such a way that all openings, in the conformable portions of the CC mask contain plating solution. The conformable material of the CC mask that contacts the substrate, layer, or material acts as a barrier to electrodeposition while the openings in the CC mask that are filled with electroplating solution act as pathways for transferring material from an anode (e.g. the CC mask support) to the non-contacted portions of the substrate (which act as a cathode during the plating operation) when an appropriate potential and / or current are supplied.

[0013] An example of a CC mask and CC mask plating are shown in FIGS. 1A - 1C. FIG. 1A shows a side view of a CC mask 8 consisting of a conformable or deformable (e.g. elastomeric) insulator 10 patterned on an anode 12. The anode has two functions. One is as a supporting material for the patterned insulator 10 to maintain its integrity and alignment since the pattern may be topologically complex (e.g. , involving isolated “islands” of insulator material). The other function is as an anode for the electroplating operation. FIG. 1 A also depicts a substrate 6, separated from mask 8, onto which material will be deposited during the process of forming a layer. CC mask plating selectively deposits material 22 onto substrate 6 by simply pressing the insulator against the substrate then electrodepositing material through apertures 26a and 26b in the insulator as shown in FIG. 1 B. After deposition, the CC mask is separated, preferably non-destructively, from the substrate 6 as shown in FIG. 1C.

[0014] The CC mask plating process is distinct from a “through-mask” plating process in that in a through-mask plating process, the separation of the masking material from the substrate would occur destructively. Furthermore, in a through mask plating process, openings in the masking material are typically formed while the masking material is in contact with and adhered to the substrate. As with through-mask plating, CC mask plating deposits material selectively and simultaneously over the entire layer. The plated region may consist of one or more isolated plating regions where these isolated plating regions may belong to a single structure that is being formed or may belong to multiple structures that are being formed simultaneously. In CC mask plating as individual masks are not intentionally destroyed in the removal process, they may be usable in multiple plating operations.

[0015] Another example of a CC mask and CC mask plating is shown in FIGS. 1D - 1G. FIG.1 D shows an anode 12’ separated from a mask 8 ’ that includes a patterned conformable material 10’ and a support structure 20. FIG. ID also depicts substrate 6 separated fromthe mask 8’. FIG. 1 E illustrates the mask 8’ being brought into contact with the substrate 6. FIG. IF illustrates the deposit 22’ that results from conducting a current fromthe anode 12’ to the substrate 6. FIG. 1 G illustrates the deposit 22’ on substrate 6 after separation frommask 8’. In this example, an appropriate electrolyte is located between the substrate 6 and the anode 12 ’ and a current of ions coming from one or both of the solution and the anode are conducted through the opening in the mask to the substrate where material is deposited. This type of mask may be referred to as an anodeless INSTANT MASK™ (AIM) or as an anodeless conformable contact (ACC) mask.

[0016] Unlike through-mask plating, CC mask plating allows CC masks to be formed completely separate fromthe substrate on which plating is to occur (e.g. separate from a three- dimensional (3D) structure that is being formed). CC masks may be formed in a variety of ways, for example, using a photolithographic process. All masks can be generated simultaneously, e.g. prior to structure fabrication ratherthan during it. This separation makes possible a simple, low-cost, automated, self-contained, and internally -clean “desktop factory” that can be installed almost anywhere to fabricate 3D structures, leaving any required clean room processes, such as photolithography to be performed by service bureaus or the like.

[0017] An example of the known electrochemical fabrication process discussed above is illustrated in FIGS. 2 A - 2F. These figures show that the process involves deposition of a first material 2 which is a sacrificial material and a second material 4 which is a structural material. The CC mask 8, in this example, includes a patterned conformable material (e.g. an elastomeric dielectric material) 10 and a support 12 which is made from deposition material 2. The conformal portion of the CC mask is pressed against substrate 6 with a plating solution 14 located within the openings 16 in the conformable material 10. An electric current, from power supply 18, is then passed through the plating solution 14 via (a) support 12 which doubles as an anode and (b) substrate 6 which doubles as a cathode. FIG. 2 A illustrates that the passing of current causes material 2 within the plating solution and material 2 from the anode 12 to be selectively transferred to and plated on the substrate 6. After electroplating the first deposition material 2 onto the substrate 6 using CC mask 8, the CC mask 8 is removed as shown in FIG. 2B. FIG. 2C depicts the second deposition material 4 as having been blanket-deposited (i. e. non-selectively deposited) over the previously deposited first deposition material 2 as well as over the other portions of the substrate 6. The blanket deposition occurs by electroplating from an anode (not shown), composed of the second material, through an appropriate plating solution (not shown), and to the cathode / substrate 6. The entire two-material layer is then planarized to achieve precise thickness and flatness as shown in FIG. 2D. After repetition of this process for all layers, the multi-layer structure 20 formed of the second material 4 (i.e. structural material) is embedded in first material 2 (i.e. sacrificial material) as shown in FIG. 2E. The embedded structure is etched to yield the desired device, i. e. structure 20, as shown in FIG. 2F.

[0018] Various components of an exemplary manual electrochemical fabrication system 32 are shown in FIGS. 3A - 3C. The system 32 consists of several subsystems 34, 36, 38, and 40. The substrate holding subsystem 34 is depicted in the upper portions of each of FIGS. 3 A - 3C and includes several components: (1 ) a carrier 48, (2) a metal substrate 6 onto which the layers are deposited, and (3) a linear slide 42 capable of moving the substrate 6 up and down relative to the carrier 48 in response to drive force from actuator 44. Subsystem 34 also includes an indicator 46 for measuring differences in vertical position of the substrate which may be used in setting or determining lay er thicknesses and / or deposition thicknesses. The subsystem 34 further includes feet 68 for carrier 48 which can be precisely mounted on subsystem 36.

[0019] The CC mask subsystem 36 shown in the lower portion of FIG. 3 A includes several components: (1 ) a CC mask 8 that is actually made up of a number of CC masks (i. e. submasks) that share a common support / anode 12, (2) precision X-stage 54, (3) precision Y-stage 56, (4) frame 72 on which the feet 68 of subsystem 34 can mount, and (5) a tank 58 for containing the electrolyte 16. Subsystems 34 and 36 also include appropriate electrical connections (not shown) for connecting to an appropriate power source (not shown) for driving the CC masking process.

[0020] The blanket deposition subsystem 38 is shown in the lower portion of FIG. 3B and includes several components: (1) an anode 62, (2) an electrolyte tank 64 for holding plating solution 66, and (3) frame 74 on which feet 68 of subsystem 34 may sit. Subsystem 38 also includes appropriate electrical connections (not shown) for connecting the anode to an appropriate power supply (not shown) for driving the blanket deposition process.

[0021] The planarization subsystem 40 is shown in the lower portion of FIG. 3C and includes a lapping plate 52 and associated motion and control systems (not shown) for planarizing the depositions.

[0022] According to another method for forming microstructures from electroplated metals (i.e. using electrochemical fabrication techniques), the formation of metal structure may be realized through mask exposures. A first layer of a primary metal is electroplated onto an exposed plating base to fill a void in a photoresist (the photoresist forming a through mask having a desired pattern of openings), the photoresist is then removed and a secondary metal is electroplated over the first layer and over the plating base. The exposed surface of the secondary metal is then machined down to a height which exposes the first metal to produce a flat uniform surface extending across both the primary and secondaiy metals. Formation of a second layer may then begin by applying a photoresist over the first layer and patterning it (i. e. to form a second through mask) and then repeating the process that was used to produce the first layer to produce a second layer of desired configuration. The process is repeated until the entire structure is formed and the secondary metal is removed by etching. The photoresist is formed overthe plating base or previous layer by casting, and patterning of the photoresist (i. e. voids formed in the photoresist) is formed by exposure of the photoresist through a patterned mask viaX-rays or UV radiation and development of the exposed or unexposed areas.

[0023] The plating base may be located onto a substrate in preparation for electroplating materials onto the substrate. The plating base typically involves the use of a sputtered film of anadhesive metal, such as chromium or titanium, and then a sputtered film of the metal that is to be plated. It is also known that the plating base may be applied over an initial layer of sacrificial material (i. e. a layer or coating of a single material) on the substrate so that the structure and substrate may be detached if desired. In such cases, after formation of the structure, the sacrificial material forming part of each layer of the structure may be removed along with the initial sacrificial layer to free the structure. Substrate materials may include silicon, glass, metals, and silicon with protected semiconductor devices.

[0024] FIGS. 4A - 41 illustrate side views of various states in an alternative known multi-layer, multi-material electrochemical fabrication process. FIGS. 4A - 4G 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. 4A, a side view of a substrate 82 having a surface 88 is shown, onto which pattemable photoresist 84 is cast as shown in FIG. 4B. In FIG. 4C, 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. 4D, a metal 94 (e.g. nickel) is shown as having been electroplated into the openings 92(a) - 92(c). In FIG. 4E, the photoresist has been removed (i.e. chemically stripped) from the substrate to expose regions of the substrate 82 which are not covered with the first metal 94. In FIG. 4F, 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. 4G 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. 4H, the result of repeating the process steps shown in FIGS. 4B - 4G 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. 41 to yield a desired 3-D structure 98 (e.g. component or device).

[0025] 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. Eventhough 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.Summary of the Invention

[0026] It is an object of some embodiments of the invention to provide an improved vertical probe which can meet size (e.g. length, cross-sectional, and array spacing requirements), force, overtravel, and / or current carrying requirements.

[0027] It is an obj ect of some embodiments of the invention to provide an improved method for forming vertical probes which can meet size (e.g. length, cross-sectional, and array spacing requirements), force, overtravel, and / or current carrying requirements.

[0028] Other objects and advantages of various embodiments of the invention will be apparent to those of skill in the art upon review of the teachings herein. The various embodiments of the invention, set forth explicitly herein or otherwise ascertained from the teachings herein, may address one or more of the above objects alone or in combination, or alternatively may address some other object ascertained from the teachings herein. It is not necessarily intended that all objects be addressed by any single aspect of the invention even though that may be the case with regard to some aspects.

[0029] In a first aspect of the invention, a vertical probe, includes: a first end portion comprising a contact region; a second end portion, different from the first end portion; and a central portion extending longitudinally and connecting the first and second end portions, wherein the central portion comprises at least three compliant arms separated from one another by a at least one gap wherein the arms bend under load and extend longitudinally, wherein a cross-section taken perpendicular to a local longitudinal direction in the central portion encounters each of the at least three arms, wherein the at least three arms comprise at least first and second outer arms that bend elastically and at least one intermediate arm located at a position that is at least partially between the first and second outer arms, wherein each of the at least first and second outer arms comprise a first material having a first yield strength while the at least one intermediate arm comprises a second material having a second yield strength which is lower than the first yield strength.

[0030] Numerous variations of the first aspect of the invention are possible including, for example: (1 ) the second material having the second yield strength being a highly conductive material having a higher conductivity than the first material having the first yield strength; (2) the second material having the second yield strength including a material selected from a group consisting of (a) copper, (b) gold, (c) silver, (d) an alloy of copper, (e) an alloy of gold, and (I) an alloy of silver; (3) the first material having the first yield strength including a material selected from a group consisting of: (a) nickel, (b) nickel-cobalt, (c) nickel-phosphor, (d) palladium, (e) beryllium-copper, (I) tungsten, (g) titanium, (h) nickel-tungsten, (i) palladium-rhenium, (j) an alloy of nickel, and (k) an alloy of palladium; (4) the contact region including a first tip material different from the first material with the first yield strength; (5) a further variation of the 4thvariation wherein the first tip material includes a material selected from a group consisting of : (a) rhodium, (b) rhenium, (c) tungsten, and (d) tungsten carbide; (6) the probe being formed from at least one layer of at least one material; (7) the probe including a plurality of layers of material; (8) a further variation of the 6thor 7thvariation wherein each layer is a substantially planar layer and wherein each layer is defined by one or more materials located between an upper andlower boundary level of a longitudinal cross-section of the probe; (9) a further variation of the 7thor 8thvariation wherein each layer of the plurality of lay ers defines a different cross-section of the probe; (10) a further variation of the 7thvariation, the 8fcvariation as it depends from the 7thvariation, or the 9thvariation wherein the plurality of lay ers include a number of lay ers selected from a group consisting of: (a) two layers, (b) three layers, (c) four layers, (d) five layers, and (e) greater than five layers; (11) a further variation of the 6thto 10thvariations where a bending plane for the probe, when in use, is a plane parallel to the plane of the at least one layer; (12) the at least one intermediate arm including a plurality of intermediate arms; (13) the outer arms of the probe being substantially linear prior to mounting or loading the probe into an array configuration; (14) at least two of the plurality of outer arms having a parallel configuration; (15) the outer arms being curved prior to mounting them to a substrate; (16) the outer arms being curved priorto loading them into array guide plates; (17) the outer arms being curved upon setting the relative XY positions of a plurality of guide plates that hold the probe as part of an array; (18) the outer arms of the probe being curved upon formation; (19) the probe being further curved upon setting the relative XY positions of a plurality of guide plates that hold the probe as part of an array; (20) at least two of the plurality of outer arms longitudinally following a locally parallel configuration, relative to each other, over at least a portion of a length of the at least two arms; (21 ) the at least two outer arms having an average radius of curvature along their longitudinal lengths that is larger than an average radius of curvature along a longitudinal length of the at least one intermediate arm; (22) a configuration and positioning of the intermediate arm providing all portions of the intermediate arm, over the entire range of motion of the probe while in use, to a limited stress level on the second material having the second yield strength that is selected from a group consisting of: (a) less than an ultimate yield strength of the second material having the second yield strength; (b) less than the yield strength of the second material havingthe secondyield strength; (c) less than 80% of the yield strength of the second material havingthe second yield strength, (d) less than 65% of the yield strength of the second material having the secondyield strength, and (e) less than 50% of the yield strength of the second material havingthe secondyield strength; (23) the secondyield strength being selected from a group consisting of : (a) less than one-half the first yield strength, (b) less than one-third the first yield strength, and (c) less than one quarter the first yield strength; (24) the at least one intermediate arm consisting of a material selected from a group consisting of: (a) a single metal and (b) a single alloy; (25) the probe having a cross-section having both a width and thickness substantially perpendicular to a local longitudinal axis of the probe in the central portion, wherein the thickness is parallel to a layer normal and the width is perpendicular to the layer normal (i. e. within the plane of a layer) and wherein a ratio of width to thickness is selected from a group consisting of: (a) <=0.25, (b) <=0.40, (c) <=0.60, (d) <= 0.80, (e) <= 1, (f) <= 1.25, (g) <= 1.7, (h) <=2.5; and (j) <=4.0; (26) a further variation of the 25thvariation wherein the width of the probe in the central portion is selected from a group consisting of: (a) <= 150 um (microns or micrometers), (b) <= 120 um, (c) <= 100 um, (d) <= 80 um, (e) <= 60 um, and (f) <= 40 um, and wherein the thickness of the probe in the central portion is selected from a group consisting of : (a) <= 150 um, (b) <= 120 um, (c) <= 100 um, (d) <= 80 um, (e) <=60 um, and (f) <=40 um; (27) theprobehaving a first bending moment and a second bending moment for a force parallel to that bending moment at a distance R therefrom, wherein the first bending moment is in a plane perpendicular to a lay er normal and perpendicular to a local longitudinal axis of the probe and the second bending moment is parallel to a layer normal and perpendicular to a local longitudinal axis of the probe, and wherein a ratio of the first and second bending moments is selected from a group consisting of: (a) <= 0.25, (b) <= 0.40, (c) <= 0.60, (d) <=0.80, (e) <= 1, (f) <= 1.25, (g) <= 1.7, (h) <=2.5; and(j) <=4.0; and (28) the second yield strength of the second material has a ratio to the first yield strength of the first material of less than 1 , more preferably less than 0.8, even more preferably less than 0.6, and most preferably less than 0.4.

[0031] In a second aspect of the invention, a two-dimensional probe array for testing a DUT, includes: at least one array structure having a plurality of openings; a plurality of vertical probes with each inserted into an opening in the at least one array structure, wherein each vertical probe comprises: a first end portion comprising a contact region; a second end portion, different fromthe first end portion, a central portion extending longitudinally and connecting the first and second end portions, wherein the central portion comprises at least three compliant arms separated from one another by at least one gap wherein the arms bend under load and run longitudinally, wherein a cross-section taken perpendicular to a local longitudinal direction in the central portion encounters each of the at least three arms, wherein the at least three arms comprise at least first and second outer arms that bend elastically and at least one intermediate arm located at a position that is at least partially between the first and second outer arms, wherein each of the at least first and second outer arms comprise a material having a first yield strength while the at least one intermediate arm comprises a material having a second yield strength which is lower than the first yield strength.

[0032] Numerous variations of the second aspect of the invention are possible and include for example: (1 ) the nominal pitch for tip-to-tip spacing in a first dimension, perpendicular to a second dimension, may be selected from a group consisting of : (i) the nominal pitch is similar for both the first and second dimensions; (ii) the nominal pitch in the first dimension is between 1 / 5 and 5 times a nominal tip-to-tip pitch in the second dimension; (iii) the nominal pitch in the first dimension is between 1 / 3 and 3 times a nominal tip-to-tip pitch in the second dimension; (iv) the nominal pitch in the first dimension is between 1 / 2 and 2 times a nominal pitch in the second dimension; (2) the array structure may include two array structures both with a plurality of openings and with the two structures forming at least part of an assembly for holding the probes such that each of a plurality of probes extends through each of the two array structures; (3) the array structure may further include at least two subarray substrates to be bonded with respective groups of probes to form at least two subarrays of probes, which are in turn bonded to an overall array substrate; (4) any of the variations noted above for the first aspect; and (5) any other alternatives set forth in the embodiments as described herein..

[0033] Other aspects of the invention will be understood by those of skill in the art upon review of the teachings herein. Other aspects of the invention may involve combinations of the above noted aspects of the invention as well as functional combinations of the variations of those aspects with each other and with other aspects of the invention. These other aspects of the invention may provide variouscombinations of the aspects presented above as well as provide other configurations, structures, functional relationships, and processes that have not been specifically set forth above.Brief Description of the Drawings:

[0034] FIGS. 1A - 1C schematically depict side views of various stages of a CC mask plating process, while FIGS. ID - 1G schematically depict side views of various stages of a CC mask plating process using a different type of CC mask.

[0035] FIGS. 2A - 2F schematically depict side views of various stages of an electrochemical fabrication process as applied to the formation of a particular structure where a sacrificial material is selectively deposited while a structural material is blanket deposited.

[0036] FIGS. 3 A - 3C schematically depict side views of various example subassemblies that may be used in manually implementing the electrochemical fabrication method depicted in FIGS. 2A - 2F.

[0037] FIGS. 4 A - 4F 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.

[0038] FIG. 4G depicts the completion of formation of the first layer resulting from planarizing the deposited materials to a desired level.

[0039] FIGS. 4H and 41 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.

[0040] FIG. 5 A provides a side view of an example probe according to a first embodiment of the invention

[0041] FIG. 5B provides a view of the probe of FIG. 5A but where a compressive force has been applied between the two ends of the probe and the probe in turn has undergone compression by elastically bending under the induced stress.

[0042] FIGS. 5C - 5 G provide various alternative cross-sectional cut views along the line of 5A-5A of FIG. 5A showing that probes ofthe example ofFIG. 5Amay be formed using a single layer (FIG. 5C) or using a plurality of layers (FIGS. 5D - 5G) wherein the formation of arm elements may exist on some layers and not on other layers such that different thicknesses and numbers of outer arms may exist as well as different thickness and numbers of intermediate arms may also exist.

[0043] FIGS. 6 A, 6B 1 - 6B3 provide a top view of an example probe as a whole (FIG. 6 A) and a view of each of three stacked individual layers (FIG. 6B1 , Layer 1 ; FIG. 6B2, Layer 2; and FIG. 6B3 - layer 3) forming the probe that in some respects is similar to that ofthe probe ofFIG. 5A but is also different in a number of ways.

[0044] FIGS. 7A, 7B1 - 7B3 provide a top view of another example probe as a whole (FIG. 7A) and a view of each of three individual layers (FIG. 7B1 , Layer 1 ; FIG. 7B2, Layer 2; and FIG. 7B3 - layer 3) forming the probe that in some respects is similar to that of the probe of FIGS. 5 A and 6Abut is also different in a number of ways.

[0045] FIGS. 8 A - 8G provide various views of layers of additional sample probes showing additional example variations that may be included in various embodiments of the invention.

[0046] FIGS. 9A - 9C provide a front view, a side view, and a top view, respectively, of an example 4-by-8 array of probes without showing array retention structures (e.g., substrates, guide plates, or other frame structures) where the probes are similar to the probe of FIGS. 6A, 6B1-6B3.

[0047] FIG. 10 provides a front view of an array with three probes shown that are similar to the probe of FIG. 8D which are held in an array configuration by a substrate (e.g., a space transformer or via substrate) to which the probes are mounted.

[0048] FIG. 11 provides a front view of an array similar to that of FIG. 10 but where, in addition to a substrate-type array retention structure, an upper guide plate is provided.

[0049] FIG. 12 provides a front view of an array similar to that of FIG. 11 but with the array substrate replaced by a lower guide plate.

[0050] FIGS. 13 A - 13C illustrate formation of another example array with three probes shown at different states of processing with the probes similar to the probe of FIG. 6Abut where the probes are plastically deformed while in an array configuration using three guide plates or deformation plates to provide the probes with a configuration similar to that of FIG. 8 A.

[0051] FIG. 14 provides another example array with three probes having configurations similar to that of the probe of FIG. 8B where the probes may be formed with such configurations or where they may be formed with configurations similar to that of the probe of FIG. 6A and then deformed once combined with array retention structures.

[0052] FIGS. 15 A - 15D illustrate different states in a process for creating a tiled probe array from a plurality of subarrays where the final array may or may not include a guide plate in addition to the subarray substrates and an overall array substrate.Detailed Description of Preferred Embodiments:Electrochemical Fabrication in General

[0053] FIGS. 1A- 1G, 2A- 2F, and 3A- 3C illustrate various features of one formof electrochemical fabrication. Other electrochemical fabrication techniques are described above. Still others may be derived from combinations of various known approaches described . All of these techniques may be combined with those of the various embodiments of various aspects of the invention to yield enhanced embodiments. Still other embodiments may be derived from combinations of the various embodiments explicitly set forth herein.

[0054] Various embodiments ofvarious aspects of the invention are directed to formation of three-dimensional structures from materials some, or all, of which may be electrodeposited (as illustrated in FIGS. 1 A - 41) or electroless deposited. 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 onemicron 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, structures having features positioned with micron level precision and minimum feature size on the order of tens of microns are to be formed. 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 extending into the 0.5 - 20 millimeter range, or somewhat larger and with features positioned with precision in the 0.1 - 10 micron range and with minimum features sizes on the order of 1 - 100 microns.

[0055] The various embodiments, alternatives, and techniques disclosed herein may form multilay er structures using a single patterning technique on all layers or using different patterning techniques on different layers. For example, various embodiments of the invention may perform selective patterning operations using conformable contact masks and masking operations (i.e. operations that use masks which are contacted to but not adhered to a substrate), proximity masks and masking operations (i.e. operations that use masks that at least partially selectively shield a substrate by their proximity to the substrate even if contact is not made), non-conformable masks and masking operations (i.e. masks and operations based on masks whose contact surfaces are not significantly conformable), 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.

[0056] 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 lay er-by- lay er 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 withinthe top and bottomboundary levels that define a different layer’s geometric configuration).

[0057] Temporary substrates on which structures may be formed may be of the sacrificial -type (i. e. destroyed or damaged during separation of deposited materials to the extent they cannot be reused),non-sacrificial-type (i. e. not destroyed or excessively damaged, i. e. not damaged to the extent they may not be reused, e.g. with a sacrificial or release layer located between the substrate and the initial layers of a structure that is formed). Non-sacrificial substrates may be considered reusable, with little or no rework (e.g. replanarizing one or more selected surfaces or applying a release layer, and the like) though they may or may not be reused for a variety of reasons.Probes:

[0058] Embodiments are directed to vertical probes orpin probes. These probes may be formed with their longitudinal axes (i. e. tip -to -tip axes, tip-to-tip heights, base-to-tip axes, or base-to-tip heights) oriented perpendicular to a layer stacking axis or lay er surface normal when being formed from a single layer or fromthe buildup of a plurality of layers (i.e. with their longitudinal axes being oriented parallel to the lateral extents of a layer or layers from which the probe is formed). Alternatively, the longitudinal axes of the probes may be formed parallel to a stacking axis of the layers or at some other angle between parallel and perpendicular to the stacking axis of the layers. Unlike cantilever probes, vertical probes typically have longitudinal extents (e.g. heights in Z) that are much greater than their lateral extends (e.g. widths in X and Y). For example, the ratio of height to maximum width for vertical probes may be in range from 5 / 1 or 10 / 1 to 100 / 1 or more. Unlike cantilever probes, vertical probes can be arranged into two-dimensional arrays with close packing, or pitch, in both X and Y directions simultaneously. As used herein, nominal pitch or minimum pitch is the closest, used or useable, tip-to-tip spacing of two adjacent similar probes that are similarly oriented. A packing ratio, PR (minimum or nominal pitch) of acceptable tip-to-tip spacing of adj acent vertical probes in X (to acceptable tip-to-tip vertical probe spacing in Y may be within 1 / 5 and 5, i.e. 1 / 5 <= PR<= 5, and is often within 1 / 2 to 2, andin practice is believed to often be within a 0.9 to 1.1 packing ratio). In many vertical probe arrays, the tip-to-tip spacing between probes in X is less than 5 times the width of the probe in X, I. e. the spacing / width ratio is less than about five, and similarly the spacing between probes in Y is less than about 5 times the width of the probe in Y. The spacing to width ratio in both X and Y is often less than 3 and is often about 2 or less.

[0059] Vertical probes of some embodiments of the invention may be formed of at least one layer that longitudinally includes a first end, second end, and a central portion, with the central portion including at least three compliant arms, or beams, that extend in parallel, wherein each of the two outer arms include a material having a first yield strength greater than a first amount and the at least one intermediate arm (or beam) formed of a second material having a second yield strength less than the first yield strength wherein the second yield strength of the material of the intermediate arm has a ratio to that of an outer arm of less than 1 , more preferably less than 0.8, even more preferably less than 0.6, and most preferably less than 0.4. The intermediate arm also most preferably has an average radius of curvature along its length that is less than an average radius of curvature of each of the outer arms along their lengths. The at least one intermediate arm is most preferably formed of a highly conductive material (e.g. a material having an electrical conductivity greater than 30 xl 0A6 siemens / meter, more preferably greater than 40 x 10A6 siemens / meter, such as gold, copper or silver) while the outer arms provide the vast majority of an elastic spring force of the probe during normal operation of the probe. In someembodiments, the outer arms, for example, may be formed of nickel, nickel-cobalt, nickel-phosphor, palladium, beryllium-copper, tungsten, titanium, nickel-tungsten, palladium-rhenium, an alloy of nickel, or an alloy of palladium. A bending moment, or tendency to bend, of the probe is preferentially, though not necessarily, in a direction parallel to a plane of the at least one layer forming the probe. Though formation of a probe from a single layer is possible, probes of many embodiments are preferentially formed from a plurality of adhered layers, and the adhered layers are preferentially formed using a multimaterial, multi-layer electrochemical fabrication process. In some embodiments, the probes are formed in a batch process that produces a plurality of probes simultaneously.

[0060] FIG. 5A provides atop view of a probe from a direction parallel to a layer normal (i.e. a side view of a probe with its longitudinal axis formed parallel to lateral extents of the layer) of an example probe according to a first embodiment of the invention wherein a longitudinal axis of the probe extends in the Y -direction, a width of the probe extends in the X-direction, and thickness of the probe extends in the Z-direction, which may provide for the thickness of one or more layers, where an intermediate portion of the probe is formed from three independent arms including two outer arms on either side of an intermediate arm (e.g. arms separated from one another by a spacing or gap (e.g. an air gap, a gap occupied by an inert gas, or a vacuum)), and where the probe is made of two materials wherein a high yield strength material having a larger radius of curvature that is used for the outer arms and the probe ends while a second, lower yield strength, and higher conductivity material having a lower average radius of curvature is used for the intermediate arm. In particular, the outer arms are made of a first material having a first yield strength and the intermediate arm is made of a second material having a second yield strength which is lower than the first yield strength. Suitably, the probe ends are also made of the first material having a first yield strength. Moreover, the first material having the first yield strength has a larger radius of curvature than the second material having the second yield strength. According to some embodiments, the second material having the second yield strength has a higher conductivity than the first material having the first yield strength. In usage, or in assembly of a plurality of probes into a probe card or other array structure, the probe axes may be relabeled such that the longitudinal axis of the probe becomes theZ-axis. In terms of build orientation, the thickness of the probe in Z may be less than or greaterthan its width in X. Due to the configuration of the probe (e.g. the width of individual arms, the thickness of individual arms versus their thickness, the spacing between individual arms, preferential bending configuration designed into the arms, or preloading or bending applied to the probe when loading into an array configuration) the probe can be made to have a preferential bending plane and associated bending moment that is parallel to the planes of the layers, perpendicular to the planes of the layers, or somewhere in-between.

[0061] FIG. 5B provides a view of the probe of FIG. 5A but where a compressive force has been applied between the two ends of the probe (e.g. by pressing one end of the probe against a contact pad or bump of a device under test (DUT) and a contact pad or bump of another circuit element associated with passing signals on to a tester (e.g. a PCB or a space transformer) and the probe in turn has compressed by elastically bending (in a bending plane or path) under the induced stress wherein theprobe is configured to preferentially bend within the plane of the sheet of paper as opposed to out of the plane of the paper wherein the highest stresses are applied to the outer arms while the configuration and material of the intermediate arm provide for easier and low stress deflection. In other embodiments, bending may be in planes with other orientations and / or bending may result in longitudinal twisting of the probe as it compresses.

[0062] Suitably, according to some embodiments of the disclosure, the second material having the second yield strength may comprise a material selected from a group consisting of: (1 ) copper, (2) gold, (3) silver, (4) an alloy of copper, (5) an alloy of gold, and (6) an alloy of silver. Moreover, the first material having the first yield strength may comprise a material selected from a group consisting of: (1) nickel, (2) nickel-cobalt, (3) nickel-phosphor, (4) palladium, (5) beryllium-copper, (6) tungsten, (7) titanium, (8) nickel-tungsten, (9) palladium-rhenium, (10) an alloy of nickel, and (11 ) an alloy of palladium. Also, the first tip material may comprise a material selected from a group consisting of: (1 ) rhodium, (2) rhenium, (3) tungsten, and (4) tungsten carbide.

[0063] FIGS. 5C - 5 G provide various cross-sectional cut views along the line of 5A-5Aof FIG. 5 A illustrating various examples of the probe of the example of FIG. 5 A may be formed of a single layer, formed of a plurality of lay ers (Layer 1 -Layer 5) where the formation of arm elements may exist on some layers and not on other lay ers such that different thicknesses and numbers of outer arms may exist as well as different thickness and numbers of intermediate arms may also exist.

[0064] FIG. 5C provides an example cut end view of the probe of FIG. 5 A from viewing direction 5 A-5A as seen in FIG. 5 A wherein the probe is shown, in this example, as being formed from a single layer (Layer 1) of two materials with the outer arms formed of a different material from that of the inner arm.

[0065] FIG. 5D provides an example cut end view of the probe of FIG. 5 A from viewing direction 5 A-5A as seen in FIG. 5 A wherein the probe is shown, in this example, as being formed from three layers (Layer 1 -Layer 3) with the formation along the cut line showing that all three layers are formed with identical configurations at least along the cross-sectional view provided by the cut line.

[0066] FIG. 5E provides an example cut end view of the probe of FIG. 5 A similarto that of FIG. 5D with the exception that there are no outer arm portions formed as part of the second layer leading to the result that there are four outer arms with a thickness of one layer each and one intermediate arm with a thickness of three layers.

[0067] FIG. 5F provides an example cut end view of the probe of FIG. 5 A similar to that of FIG. 5D with the exception that there are no intermediate arm portions formed with a second layer such that in effect two outer arms are formed with a thickness of three layers each and two intermediate arms are formed with a thickness of one layer each and spaced apart from one another by one layer.

[0068] FIG. 5G provides an example cut end view of the probe of FIG. 5 A from viewing direction 5 A-5A as seen in FIG. 5 A wherein the probe is shown, in this example, as being formed from five layers (Layer 1 -Layer 5) with the formation along the cut line showing all five layers are formed with identical configurations at least along the cross-sectional view provided by the cut line.

[0069] Numerous other variations of the probe of FIGS. 5 A - 5Gare possible and include, for example: (1) probes with different probe tip configurations on one or both ends, (2) probes having tip or contact materials different from elastic outer arm material and different intermediate arm material, (3) probes with different numbers of outer arms and intermediate arms than set forth in the specific examples illustrated, (4) probes with different lengths, (5) probes with different widths, (6) probes with different thicknesses, (7) probes with different arm widths and / or thicknesses at different positions along their lengths, (8) probes with outer arms that do not extend straight from one end to the other end but have designed curvature or curves at various locations along their lengths (e.g. bowed or serpentine configurations), (9) probes with individual outer arms that are located in one or more different layers along their lengths (e.g. exist on one or more layers on one end and one or more different layers on the other end, or exist on one or more layers on both ends and exist on one or more different layers in an intermediate region, e.g. providing arms with spiraling configurations), (10) probes where the intermediate arm or arms are made from a single material where that material is different from any material of one of the outer arms, (11) probes where one or more of the outer arms are made from more than one material wherein each of the more than one material is different from a material forming at least one intermediate arm wherein the at least one different material has a yield strength that is higher, and / or conductivity that is lower than, a corresponding property of the material of the at least one intermediate arm; (12) probes wherein at least one intermediate arm is made from more than one material wherein each of the more than one material is different from a material forming at least one outer arm and the at least one different material has a yield strength that is lower, and / or conductivity that is higher, than a corresponding property of the material of the at least one outer arm; (13) probes where at least one intermediate arm and at least one outer arm include the same material but where one of such arms includes a different material wherein the different material, if on an outer arm, has a higher yield strength and / or lower conductivity than a material or materials of the intermediate arm, or if on an intermediate arm, the different material has a loweryield strength and / or a higher conductivity than a material or materials of the outer arm, (14) the gaps between at least one intermediate arm and at least two outer arms extend unbroken for a portion of an overall probe length selected from a group consisting of: (a) greaterthan 30%, (b) greater than 50%, (c) greaterthan of 70%, (d) greater than 80%, and (e) greater than 90%, (15) the gap between at least one intermediate arm and the at least two outer arms comprises a number of gaps selected from a group consisting of : (a) no more than four, (b) no more than three, (c) no more than two, and where the length of the summed gaps between each of the at least two outer arms and the at least one intermediate arm is an amount selected from a group consisting of: (a) greaterthan 30%, (b) greaterthan 50%, (c) greater than of 70%, (d) greater than 80%, and (e) greaterthan 90%, (16) at least one gap extends a length of the intermediate arm without break; (17) a plurality of gaps extend the length of the intermediate arm without break; (18) all gaps extend a length of the intermediate arm without break; (19) at least one gap extends a length of an outer arm without break; (20) a plurality of gaps extend the length of their adjacent outer arm without break; and (21) all gaps extend a length of atleast one outer arm without break. Other variations are possible and will be apparent to those skill in the art upon reviewing the teachings herein.

[0070] FIGS. 6 A, 6B1 - 6B3 provide a longitudinal view of an example probe (FIG. 6 A) and views of each of three individual layers (FIGS. 6B1 to 6B3) that make up the probe. The probe is different in some way from that of FIG. 5 A. The probe is formed from three layers (Layer 1 , Layer 2 and Layer 3) as can be seen in the first , second, and third layer views of FIGS. 6B1, 6B2, and 6B3. The first tip is formed with a first tip material that may be different from the material of the outer arms as can be seen in FIGS. 6A and 6B2. The second tip is formed with a second tip material that may be different from the first tip material and also different from the material of the outer arms as can be seen in FIGS. 6A and 6B2. The first tip extends beyond the materials of the first and third layers and extends between the material bridging the outer arm material of the first and third layers as can be seen by comparing FIG. 6B2 to both of FIGS. 6B1 and 6B3. The second tip extends beyond the materials of the first and third layers and extends between and interlocks with the material bridging the outer arm material of the first and third layers (i. e. has reentrant features with respect to the bridging outer arm material) as can be seen by comparing FIG. 6B2to both of FIGS. 6B1 and 6B3. In some variations, for example, probe tip or contact materials may include rhodium, rhenium, tungsten, tungsten carbide, or other hard and wear resistant materials. In particular, the outer arms are made of a first material having a first yield strength and the intermediate arm is made of a second material having a second yield strength which is lower than the first yield strength. Suitably, the probe ends are also made of the first material having a first yield strength. Moreover, the first material having the first yield strength has a larger radius of curvature than the second material having the second yield strength. According to some embodiments, the second material having the second yield strength has a higher conductivity than the first material having the first yield strength.

[0071] FIGS. 7A, 7B1 - 7B3 provide a longitudinal view of another example probe and views of each of three individual layers that make up the probe. The probe is different from that of FIG. 5 A in a number of ways. The probe is formed from three layers (Layer 1 , Layer 2 and Layer 3) as can be seen in the first, second, and third layer views of FIGS. 7B1, 7B2, and 7B3. The first tip is formed with a first tip material that may be different from the material of the outer arms as can be seen in FIGS. 7 A and 7B2. The second tip is formed with a second tip material that may be different from the first tip material and also different from the material of the outer arms as can be seen in FIGS. 7A and 7B2. The material of the intermediate arm and of the first and second tips bridges the outer layer material on first and third layers. The intermediate arm material and a material of the outer arms connect the outer arms to one another in the first and second end regions. The intermediate arm material on the second layer is interlocked between the first and third layers by the intermediate arm material of the first and third layers extending over the bridging outer arm material of the second layer as can be seen by comparing FIG. 7B2 to both of FIGS. 7B1 and 7B3. As previously, the outer arms are made of a first material having a first yield strength and the intermediate arm is made of a second material having a second yield strength which is lower than the first yield strength. Suitably, the probe ends are also made of the first materialhaving a first yield strength and the first material having the first yield strength has a larger radius of curvature than the second material having the second yield strength. The second material having the second yield strength mat have a higher conductivity than the first material having the first yield strength.

[0072] FIGS. 8A- 8G provide various longitudinal views (i.e. showingatop viewofthe probe along a layer stacking direction) of various additional sample probes showing additional example variations that may be included in various embodiments of the invention.

[0073] FIG. 8A illustrates an example probe where both outer arms are formed with curved configurations that provide a preferential bending direction when the probe is compressed longitudinally where the first and second probe ends remain vertically aligned.

[0074] FIG. 8B illustrates an example probe where both outer arms are formed with curved configurations that provide a preferential bending direction when the probe is compressed longitudinally where the first and second probe ends are offset in X from one another upon formation.

[0075] FIG. 8C illustrates an example probe where tips extending beyond the outer arm material are removed in favor of the tips that correspond to the ends of outer arm bridging material wherein a different material may be used in forming end regions associated with any intermediate or hidden outer layer.

[0076] FIG. 8D illustrates an example probe where two primary differences from the probe of FIG. 5 A exist: (1) the second tip region extends beyond the outer arm material while any extension beyond the outer arm material for the first tip region is non-existent in favor of a tip or contact that corresponds to the end of the outer arm material, and (2) the probe includes four sample tabs that extend beyond the outer arms (i. e. two on either side) which may be used as stops or alignment features when loading probes into one or more array guide plates or other structures , e.g. a substrate with alignment openings. In different embodiments, fewer tabs may be used, different numbers of tabs may be used, tabs may take on different shapes, tabs may be located in different longitudinal positions on the left and right sides (or front and back - not shown) to promote, for example, a preferred bending direction when engaging one or more array structures tabs may be located in different locations, and the like.

[0077] FIG. 8E provides an example probe similar to that of FIG. 8D but the sample tabs are replaced by indents, or notches, in the bridging and outer arm material. Other variations are possible and include, for example, using a combination of tabs and indents.

[0078] FIG. 8F provides an example probe similar to FIGS. 8D and 8E with the exception that tabs and notches are removed but the intermediate arm is provided with end mounting locations that are offset to opposite sides of the center line of the probe (in X) as opposed to being centered between the two outer arms (i.e. located along a centerline of the probe in X).

[0079] FIG. 8G provides an example probe similar to that of FIG. 8F with the exception that end mounting locations of the intermediate arm are not offset to opposite sides of the probe center (in X) but are offset to a single side of the probe center.

[0080] FIGS. 9A - 9C provide a front (X-Y) view, a side (Y -Z) view, and a top (X-Z) view, respectively, of an example 4-by-8 array 900 of probes 901 without showing array retention structures(e.g., substrates, guide plates, or other frame structures) where the probes are similar to the probe of FIGS. 6 A— 6B3. Each probe includes a first end 911 and first tip 91 IT, a second end 912 and second tip 912T, at least one intermediate arm 921, at least a first outer arm 931 A and a second outer arm 931B wherein the at least one intermediate arm is formed of a different material than that used on either of the first outer arm 931 A or the second outer arm 93 IB as well as that used as a contact material as part of the first tip 911 T or the second tip 912T. In the present embodiment, the longitudinal axis of the probes is the Y -axis while the layer stacking direction for probe formation is the Z-axis. In some variations, other build orientations may be used. Numerous other variations are also possible including, for example: (1 ) the probes having other configurations, (2) the probes using a different number of materials, (3) the materials having different properties, (4) the probes used in the array having more than one configuration, (5) the array having different uniform or non-uniform probe spacings or pitches, (6) the array using a different number of probes, and (7)tip material being or not being partially embedded or otherwise interlocked with the material of the outer arms or the material of the intermediate arm. FIG. 9C shows the tip ends 91 IT of each of the thirty -two probes in the exemplaiy array 900 along with the ends 93 IT of the adjoining layers of outer arm material (e.g., spring material) 931Aand931B which sandwich a portion ofthetip region as exemplified in FIGS. 6B1 - 6B3. The nominal pitches Pl and P2 for tip-to-tip spacing in the Z-axis and X-axis respectively are shown in Fig. 9C.

[0081] According to embodiments of the invention, the two-dimensional probe array 900 further comprises at least one array structure (not shown in the figure), the probes 901 being retained in the array structure having a similar probe pitch fortip-to-tip spacing in both a first dimension (Z) and a second dimension (X), perpendicular to the first dimension (Z). Preferably, a nominal pitch for tip-to-tip spacing in the first dimension (Z), is between 1 / 5 and 5 times a nominal tip-to-tip pitch in the second dimension (X).

[0082] FIG. 10 provides a front view of an array 1000 with three probes 1001 shown that are similar to the probe of FIG. 8D which are held in an array configuration by a substrate 1041 (e.g., a space transformer or via substrate) to which the probes are mounted. Rach probe 1001 includes a first end 1011 and first tip 101 IT, a second end 1012, at least one intermediate arm 1021, at least a first outer arm 1031 A and a second outer arm 103 IB wherein the at least one intermediate arm 1021 is formed of a different material than that used on either of the first outer arm 1031A orthe second outer arm 1031 as well as that used as a contact material as part of the first end 1011 and first tip 1011 T or the second end1012. In particular, the substrate 1041 is an array structure having a plurality of openings 1041 A wherein the probes 1001 , in particular the second end 1012 thereof, are inserted.

[0083] Moreover, as with the other embodiments, numerous variations of the embodiment of FIG. 10 are possible and include, for example: (l)use of different numbers of probes, (2) probes with different configurations, (3) probes bonded to the substrate via solder, ultrasonic bonding, laser welding, wedging or press fitting into openings in the substrate, or the like, (4) use of multi-part substrates, (5) use of substrates with different thicknesses, (6) use of different substrate configurations, and (7) use of singlematerial or multi-material substrates with or without conductive vias, with or without through holes, without or without shielding, and the like.

[0084] FIG. 11 provides a front view of an array 1100 similar to that of FIG. 10 but where, in addition to a substrate array retention structure 1141 having a plurality of openings 1141 A, an upper guide plate 1151 U having a plurality of openings 1151UA is provided to aid in retaining and positioning the probes 1101.

[0085] Each probe 1101 of FIG. 11 includes at least one intermediate arm 1121, at least a first outer arm 1131 A and a second outer arm 113 IB wherein the at least one intermediate arm 1121 is formed of a different material than that used on either of the first outer arm 1131 A or the second outer arm1131 B as well as that used as a contact material as part of the first end 1111 and first tip 111 IT or the second end 1112. As with the other embodiments herein, numerous variations are possible and include for example use of more than one guide plate.

[0086] FIG. 12 provides a front view of an array 1200 of probes 1201 similar to that of FIG. 11 including an upper guide plate 1251U having a plurality of openings 1251UA but with the substrate replaced by a lower guide plate 125 IL having a plurality of openings 125 ILA, the upper guide plate1251 U and lower guide plate 125 IL being the array structure having a plurality of openings wherein the plurality of vertical probes 1201 are inserted. As in the previous embodiments, each probe 1201 of FIG.12 includes at least one intermediate arm 1221, at least a first outer arm 1231 A and a second outer arm1231 B wherein the at least one intermediate arm 1221 is formed of a different material than that used on either of the first outer arm 1231 A or the second outer arm 123 IB as well as that used as a contact material as part of the first end 1211 and first tip 121 IT or the second end 1212 and second tip 1212T. As with the other embodiments set forth herein, numerous variations of the embodiment of FIG. 12 are possible.

[0087] FIGS. 13 A - 13C illustrates formation of another example array 1300 with three probes 1301 shown with each figure showing a different state of processing where the probes are similar to the probe of FIG. 6A but where the probes are plastically deformed while in an array configuration using three guide plates or deformation plates 1351U, 135 IL, and 1351Mto provide the probes with a configuration similarto that of FIG. 8 A. FIG. 13A shows the state of the process after probe preforms 1301P are formed andpositioned within openings 1351UA, 1351MA, 135 ILA in the three guide plates 1351U, 1351M, 1351L to form a preform array 1300P. Each probe 1301 ofFIG. 13Aincludes at least one intermediate arm 1321 , at least a first outer arm 1331 A and a second outer arm 1331B wherein the at least one intermediate arm 1321 is formed of a different material than that used on either of the first outer arm 1331 A or the second outer arm 1331 B. The upper guide plate 1351U, intermediate guide plate1351 M and lower guide plate 1351 L form the array structure having a plurality of openings wherein the plurality of vertical probes 1301 are inserted. FIG. 13B shows the state of the process after the middle or intermediate guide plate 1351 M is moved to the right relative to the upper and lower guide plates 1351 U and 135 IL to cause plastic deformation of the probes 1301 as can be seen by arrow 1352U, 1352L, and1352M. FIG. 13C shows the state of the process after the middle guide plate 1352M is moved to aposition adjacent to or in proximity to the lower guide plate 1352L. In some variations, the lower and intermediate guides 1351L, 135 IM when placed in proximity to each other may be slightly laterally shifted to aid in securing the probes and the guides together while still allowing some amount of longitudinal movement of the lower probe tips 1312T. In some variations, the intermediate guide platel 35 IM may be located at a different longitudinal level to cause bending at a different location. In still other variations, the intermediate and / or other guide plates may be moved to different longitudinal levels in a serial fashion to create more than a single bending in the probes based on a series of bending operations. In still further variations, more than three guide plates may be used for retention purposes and / or for simultaneous multiple level deformation orbending of the probes.

[0088] FIG. 14 provides another example array 1400 with three probes 1401 having configurations similar to that of the probe of FIG. 8B where the probes may be formed with such configurations or where they may be formed with configurations similar to that of the probe of FIG. 6A and then deformed once combined with array retention or shaping structures. The probe array 1400 comprises an upper guide plate 1451 U having a plurality of openings 1451UA and a lower guide plate1451 L having a plurality of openings 145 ILA forming the array structure having a plurality of openings wherein the plurality of vertical probes 1401 are inserted. According to an embodiment, the probes 1401 are configured by shifting the upper guide plate 1451U with respect to the lower guide plate 145 IL according to respective shifts SHI and SH2. As with the other embodiments set forth herein, numerous variations of the array illustrated in this embodiment are possible. Even in this example of FIG. 14, each probe 1401 includes at least one intermediate arm 1421, at least a first outer arm 1431 A and a second outer arm 143 IB wherein the at least one intermediate arm 1421 is formed of a different material than that used on either of the first outer arm 1431 A or the second outer arm 143 IB.

[0089] FIGS. 15 A - 15D illustrate different states in a process for creating a tiled probe array1500 from a plurality of subarrays 1500S (two in the embodiments as illustrated) where the final array may or may not include a guide plate in addition to an overall array substrate 1541 and subarray substrates 154 IS. Each subarray substrate 1541S andthe overall array substrate 1541 are shown with bonding pads 1561 and the probes 1501 and / or substrates are also shown as carrying a bonding material (e.g., solder) 1562 which can be made to cause bonding of the probes 1501 to the subarray substrates 154 I S (FIG. 15 A) or the subarray substrates 1541S to the overall array substrate 1541 (FIG: 15B) as necessary. FIG. 15 Adepicts the state of the process after probes 1501 in array positions 1500P are positioned laterally over two separate subarray substrates 1541 S in preparation for longitudinal movement toward the subarray substrates and bonding thereto at the bonding pads 1561 using the bonding material 1562 provided on the lower ends of the probes. As in previous examples, each probe1501 includes a first end 1511 with a first tip 1511T, a second end 1512, at least one intermediate arm 1521, at least a first outer arm 1531 A and a second outer arm 153 IB. FIG. 15B depicts the state of the process after the probes 1501 and subarray substrates 1541 S have been bonded and laterally aligned with an overall array substrate 1541 for subsequent longitudinal movement and bonding of the subarray substrates 1541S to the overall array substrate 1541 via the bonding material 1562 on thepads 1561 ofthe overall array substrate. FIG. 15C shows the state of the process after the bonding of the subarray substrates 1541S andthe overall substrate 1541 is completed. FIG. 15D shows an optional state ofthe process where an upper guide plate 1551 has been added as part of the array retention elements. As with the other embodiments numerous alternatives to the embodiment illustrated in FIGS. 15 A - 15D are possible and include use of a frame instead of an overall array substrate where the frame and / or subarrays substrates have border regions and / or features for engaging the features of the other array structures to provide for a stable and functional array. In still other variations, the subarray substrates may be replaced with other array structures such that bonding or aligned engagement of subarray groups of probes occurs in an overall array configuration without necessarily including a substrate to which probes 1501 are bonded.Further Comments and Conclusions

[0090] In addition to the probe variations referenced above, probe structures may take on a variety of different forms, be formed using different processes, and be made to contain a variety of different materials to improve overall probe and array functionality. In some embodiments, dielectrics may be incorporated into the probes and / or array structures to aid in ensuring electrical isolation between individual probes, groups of probes, or between separated conductive paths within single probes.

[0091] Various other embodiments of the present invention exist. For instance, 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, nickelphosphorous, nickel-cobalt, palladium, palladium-cobalt, gold, copper, tin, silver, zinc, solder, rhodium, or 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.

[0092] 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.

[0093] 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.

[0094] 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. Furthermore, alternatives acknowledged in association with one embodiment, are intended to apply to all embodiments to theextent that the features of the different embodiments make such applications functional and do not otherwise contradict or remove all benefits of the adopted embodiment.

[0095] 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.

[0096] 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

CLAIMS1. A vertical probe (901, 1001, 1101, 1201, 1301, 1301P, 1401, 1501), comprising: a first end portion (911,1011, ... , 1511) comprising a contact region; a second end portion (912, 1012, ... , 1512), different from the first end portion; and a central portion extending longitudinally and connecting the first and second end portions, wherein the central portion comprises at least three compliant arms (931 A, 921, 931B,..., 1531 A, 1521, 1531B) separated from one another by at least one gap wherein the at least three compliant arms bend under load and run longitudinally, wherein a cross-section taken perpendicular to a local longitudinal direction in the central portion encounters each of the at least three compliant arms, wherein the at least three compliant arms comprise at least first and second outer arms (931A, 931B, ... , 1531A, 1531B) that bend elastically and at least one intermediate arm(921, ... , 1521) located at a position that is at least partially between the first and second outer arms (931 A, 931 B, ... , 1531A, 153 IB), wherein each of the first and second outer arms (931A, 931B, ... , 1531A, 1531B) comprise a first material having a first yield strength while the intermediate arm (921, ... , 1521 ) comprises a second material having a second yield strength which is lower than the first yield strength.

2. The probe of claim 1 wherein the second material having the secondyield strength is a highly conductive material having a higher conductivity than the first material having the first yield strength.

3. The probe of claim 2 wherein the second material having the secondyield strength comprises a material selected from a group consisting of : (1 ) copper, (2) gold, (3) silver, (4) an alloy of copper, (5) an alloy of gold, and (6) an alloy of silver.

4. The probe of claim 1 wherein the first material having the first yield strength comprises a material selected from a group consisting of: (1 ) nickel, (2) nickel-cobalt, (3) nickel-phosphor, (4) palladium, (5) beryllium-copper, (6) tungsten, (7) titanium, (8) nickel-tungsten, (9) palladium-rhenium, (10) an alloy of nickel, and (11) an alloy of palladium.

5. The probe of claim 1 wherein the contact region comprises a first tip material different from the first material with the first yield strength.

6. The probe of claim 5 wherein the first tip material comprises a material selected from a group consisting of: (1) rhodium, (2) rhenium, (3) tungsten, and (4) tungsten carbide.

7. The probe of claim 1 wherein the probe (901, ... , 1501) is formed from at least one layer of at least one material.

8. The probe of claim 1 wherein the probe (901, 1501) comprises a plurality of layers of material.

9. The probe of claim 8 wherein each layer is a substantially planar layer and wherein each layer is defined by one or more materials located between an upper and lower boundary level of a longitudinal cross-section of the probe (901, ... , 1501).

10. The probe of claim 9 wherein a bending plane for the probe (901 , ... , 1501), when in use, is a plane parallel to a plane of the at least one layer.

11. The probe of claim 1 wherein the at least one intermediate arm (921, ... , 1521) comprises a plurality of intermediate arms.

12. The probe of claim 1 wherein the outer arms (931A, 93 IB, ... , 1531A, 153 IB) of the probe (901, ... , 1501 ) are substantially linear prior to mounting or loading the probe into an array configuration.

13. The probe of claim 1 wherein the outer arms (931 A, 93 IB, ... , 1531 A, 153 IB) are curved prior to mounting them to a substrate (1041, 1141, 1541S, 1541).

14. The probe of claim 1 wherein the outer arms (931 A, 93 IB, ... , 1531A, 153 IB) are curved prior to loading them into array guide plates (1351U, 1351M, 1351L).

15. The probe of claim 1 wherein the outer arms (931 A, 93 IB, ... , 1531 A, 153 IB) have an average radius of curvature along their longitudinal lengths that are larger than an average radius of curvature along a longitudinal length of the intermediate arm (921, ... , 1521).

16. The probe of claim 1 wherein a configuration and positioning of the intermediate arm (921, ... , 1521) provides all portions of the intermediate arm, over the entire range of motion of the probe (901, ... , 1501) while in use, to a limited stress level on the second material having the second yield strength that is selected from a group consisting of: (1) less than an ultimate yield strength of the second material having the second yield strength; (2) less than the second yield strength of the second material having the secondyield strength; (3) less than 80% of theyield strength of the second material having the second yield strength; (4) less than 65 % of the yield strength of the second material having the second yield strength; and (5) less than 50% of the yield strength of the second material havingthe secondyield strength.

17. A two-dimensional probe array (900, ... , 1500) for testing a DUT, comprising: at least one array structure (1041; 1141, 1151U; 1251U, 125 IL; 1351 U, 1351 M, 1351 L; 1451U, 145 IL having a plurality of openings (1041A; 1141A, 1151UA; 1251UA, 1251LA; 1351UA, 1351MA, 1351LA; 1451UA, 1451LA; a plurality of vertical probes (901, ... , 1501) with each inserted into an opening in the at least one array structure, wherein each vertical probe comprises: a first end portion (911, 1011, ... , 1511) comprising a contact region; a second end portion (912, 1012, ... , 1512), different from the first end portion; and a central portion extending longitudinally and connecting the first and second end portions, wherein the central portion comprises at least three compliant arms separated from one another by at least one gap wherein the arms bend under load and run longitudinally, wherein a cross-section taken perpendicular to a local longitudinal direction in the central portion encounters each of the at least three arms, wherein the at least three arms comprise at least first and second outer arms (931A, 93 IB, ... , 1531A, 153 IB) that bend elastically and at least one intermediate arm(921, ..., 1521) located at a position that is at least partially between the first and second outer arms, wherein each of the at least first and second outer arms comprise a first material having a first yield strength while the at least one intermediate arm comprises a second material having a second yield strength which is lower than the first yield strength.

18. The array of claim 17 wherein the nominal pitch for tip-to-tip spacing in a first dimension, perpendicular to a second dimension, is selected from a group consisting of: (i) the nominal pitch is similar for both the first and second dimensions, (ii) the nominal pitch in the first dimension is between 1 / 5 and 5 times a nominal tip-to-tip pitch in the second dimension; (iii) the nominal pitch in the first dimension is between 1 / 3 and 3 times a nominal pitch in the second dimension; (iv) the nominal pitch in the first dimension is between 1 / 2 and 2 times a nominal pitch in the second dimension.

19. The array of claim 17 wherein the array structure comprises two array structures both with a plurality of openings and with the two structures forming at least part of an assembly for holding the probes such that each of a plurality of probes extends through each of the two array structures.

20. The array of claim 17 wherein the array structure further comprises at least two subarray substrates (1541 S) to be bonded with respective groups of probes to form at least two subarrays (1500S) of probes, which are in turn bonded to an overall array substrate (1541).

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