US20060211313A1 - Programmed material consolidation processes for fabricating electrical contacts and the resulting electrical contacts - Google Patents

Abstract

An electrical contact for use with a semiconductor device, a carrier, a probe card, or another substrate includes a dielectric core, a conductive coating on at least a portion of the core, or both that are at least partially fabricated by a programmed material consolidation process, such as, but not limited to, stereolithography, in which unconsolidated material is selectively consolidated in accordance with a program. The electrical contact may be flexible and resilient or it may be rigid. Protective structures may accompany flexible, resilient contacts to prevent deformation thereof beyond their elastic limits.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• This application is a divisional of application Ser. No. 10/788,941, filed Feb. 27, 2004, pending.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to electrical contacts for use with semiconductor devices. The electrical contacts of the present invention may be used to provide temporary electrical connections as semiconductor devices are being burned in or otherwise tested. More specifically, the present invention relates to electrical contacts which include stereolithographically fabricated portions. The present invention also includes semiconductor devices, carriers, probe cards, and other substrates that employ such electrical contacts. Additionally, the present invention includes methods relating to fabrication of the electrical contacts of the present invention and structures incorporating same.
• 2. Background of Related Art
• Numerous types of electrical contacts that are configured to provide temporary communication between the bond pads or other contacts of a semiconductor device and corresponding terminals or other contacts of a test substrate, carrier substrate, or other electronic component have been developed and used in the art.
• Several examples of temporary electrical contacts have been developed by FormFactor, Inc., of Livermore, Calif., and are described in U.S. Pat. No. 5,476,211, as well as in other U.S. Patents referenced hereinbelow that have been assigned to FormFactor (hereinafter collectively “the FormFactor Patents”). Each of these temporary electrical contacts is a compressible, resilient element which is secured to a bond pad of a semiconductor device. They may include a core and an outer coating, both of which are formed from electrically conductive materials. The core may comprise a relatively soft material, or material which is subject to plastic deformation, while the outer coating may comprise a more rigid material, which imparts the electrical contact with elastic properties. Alternatively, the core may be formed from a more rigid, elastic material, while the coating is formed from a material that enhances adhesion of the electrical contact to a bond pad of a semiconductor device.
• The electrical contacts that are described in the FormFactor Patents are represented to be useful for providing temporary electrical connection between the bond pads of a semiconductor device and the contacts of a test or burn-in substrate. They may also provide permanent electrical connections between the bond pads of the semiconductor device and corresponding contacts (i.e., bond pads, terminals, leads, etc.) of another semiconductor device, a carrier, another semiconductor device component, or another electronic device.
• The FormFactor Patents teach that wire-bonding apparatus may be used to form the core of an electrical contact of the type described therein, while conventional deposition or plating methods may be used to coat each core with another layer of conductive material. As conventional wire-bonding apparatus are typically configured to form only a single conductive element (e.g., bond wire, electrical contact, or other conductive structure) at a time, and since there may be thousands of bond pads on a substrate (e.g., silicon wafer) upon which numerous semiconductor devices are carried, the electrical contact fabrication processes that are described in the FormFactor Patents may be extremely and undesirably time consuming. Furthermore if, as described in the FormFactor Patents, gold is used to form the cores of numerous electrical contacts, the cost of forming the cores may be extremely and undesirably expensive.
• The contacts described in the FormFactor Patents may be used, for example, in probe cards, which are used to establish a temporary connection between a semiconductor device and a test substrate or burn-in substrate. The contacts are positioned at locations that correspond to the locations of corresponding bond pads of the semiconductor device and terminals of the test substrate or burn-in substrate. Thus, the contacts are positioned so as to align between corresponding bond pads and terminals when the probe card is aligned between the semiconductor device and the test substrate or burn-in substrate. The compressibility of such contacts imparts the probe card with dimensional tolerance for the spacing between the semiconductor device and the test substrate or burn-in substrate.
• Whether the Form Factor contacts are used with a probe card or another type of semiconductor device component, they may be compressed or deformed beyond their elastic limits, which will render them useless.
• Accordingly, processes are needed by which electrical contacts may be more efficiently and cost-effectively fabricated, as are electrical contacts that are formed by such processes, protective structures for preventing damage to such electrical contacts, and semiconductor devices, carriers, probe cards, and other substrates with which such electrical contacts may be assembled.
SUMMARY OF THE INVENTION
• The present invention, in several embodiments, includes electrical contacts, which are also referred to herein as “contacts” for simplicity, that may be at least partially fabricated by use of stereolithographic fabrication processes, as well as semiconductor devices, carriers, probe cards, and other substrates that include such contacts.
• A contact, in an exemplary embodiment, includes a core which is stereolithographically formed or fabricated, as well as a conductive coating on at least a portion of the core. As the core is stereolithographically fabricated, it may include a single layer or multiple layers that are at least partially superimposed, contiguous, and mutually adhered to one another. The contact may be rigid or comprise a compressible, resilient member.
• In another exemplary embodiment, a contact according to the present invention includes a conductive core disposed within a stereolithographically fabricated shell. The shell, which may include a single layer or a plurality of superimposed, contiguous, mutually adhered layers, may be formed with a channel extending therethrough. The channel may then be filled with the conductive material of the core, which is exposed at both ends of the shell.
• In yet another aspect, the present invention includes methods for fabricating contacts. One exemplary embodiment of a contact fabrication method according to the present invention includes stereolithographically fabricating a core of the contact, then coating at least portions of the core with one or more layers (or sublayers) of conductive material.
• A method for fabricating a contact in accordance with teachings of the present invention may include the formation of recesses within a fabrication, or sacrificial, substrate and coating the surfaces of the fabrication substrate with one or more material layers that will facilitate the subsequent release of contacts therefrom. Cores of the contacts may then be formed at the locations of the recesses, with the configuration of the base of each contact being at least partially defined by the recess within which it is formed. Thereafter, the cores may be at least partially coated with one or more layers (or sublayers) of conductive material. Once the contacts have been fabricated, they may be released from the fabrication substrate, which may then be discarded or reused to fabricate more contacts.
• In another, similar embodiment of the method, the fabrication substrate may lack recesses.
• In another embodiment of contact fabrication method according to the present invention, the foregoing processes may be used to form contacts that incorporate teachings of the present invention directly on the contact pads of a semiconductor device, an interposer, a carrier substrate, or the like.
• Accordingly, another aspect of the present invention involves semiconductor device components that include the inventive contacts.
• In another aspect, the present invention includes probe cards, which are useful in testing and burning-in semiconductor devices that include the inventive contacts. An exemplary embodiment of a probe card according to the present invention may include contact pads with one or more types of compressible, resilient electrical contacts.
• In addition, methods for fabricating probe cards are within the scope of the present invention.
• One embodiment of a method for fabricating a probe card may employ the above-described processes for forming contacts and, prior to releasing the contacts from the sacrificial substrate, fabricating a support plate around intermediate sections of the contacts. Accordingly, the base of each contact is located on one side of the support plate and the tip of each contact is located on the other side of the support plate. As such, the support plate is fabricated in such a way that the contacts become trapped thereby. Nonetheless, it may be possible for the contacts to move relative to the support plate, along their lengths and in a direction which is transverse to a plane in which the support plate is located. The resulting structure may comprise a probe card which is useful for testing semiconductor devices with bond pads that are arranged complementarily to the arrangement of contacts on the support plate, as well as with a test or burn-in substrate that includes terminals that are positioned correspondingly to the positions of contacts on the support plate.
• Alternatively, in another embodiment, a probe card may be fabricated by forming apertures through a substrate at areas where contacts are to be located. Of course, the apertures are also positioned correspondingly to the locations of corresponding terminals of a test or burn-in substrate with which the probe card is to be used, as well as to the locations of bond pads of a semiconductor device with which the probe card is to be used. Outer shells of the contacts are then formed within the apertures and in such a way as to protrude from the opposite major surfaces of the substrate. A channel may be formed through each outer shell as that outer shell is being fabricated or following fabrication of the outer shell. Conductive material, which may be introduced into the channels or maintained in position within the apertures of the substrate while at least portions of outer shells are being fabricated, extends completely through each outer shell to form a conductive core of the corresponding contact. The conductive material is exposed at each end of the contact to facilitate connection of a bond pad of a semiconductor device with a corresponding terminal of a test substrate or burn-in substrate.
• The present invention also includes protective structures that prevent damage to contacts according to the present invention. Such a protective structure may include one or more elements that are located adjacent to regions of contacts that protrude from a substrate, such as a semiconductor device, a carrier, a probe card, or another electronic component. In addition, a protective structure of the present invention is configured to prevent a contact of the present invention from being bent or otherwise deformed beyond its elastic limit (i.e., the limit from which it will not return substantially to its original configuration). Each element of the protective structure may protrude a lesser distance from the substrate than the adjacent protruding portion. Alternatively, if the protective structure is formed from a material that imparts it with some compressibility or flexibility, it may protrude substantially the same distance from the substrate as, or even a greater distance than, the adjacent protruding portion of the contact protrudes from the substrate.
• Some embodiments of protective structures according to the present invention include at least one receptacle that laterally surrounds at least a portion of at least one contact. A height of the protective structure (i.e., the distance the protective structure protrudes from the substrate), a distance walls of the receptacle are spaced apart from the contact, or some combination of these dimensions may prevent compression, flexure, or bending or other deformation of the contact beyond its elastic limit.
• Other embodiments of protective structures that incorporate teachings of the present invention include at least one element (e.g., a post) that protrudes from a substrate adjacent to a corresponding contact. The at least one protruding element has a height which will prevent compression or flexion of the contact beyond its elastic limit as that contact is biased against a corresponding bond pad, terminal, or other contact element.
• Other features and advantages of the present invention will become apparent to those of ordinary skill in the art through consideration of the ensuing description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
• In the drawings, which depict features of exemplary embodiments of various aspects of the present invention:
• FIG. 1 is a side view of an exemplary contact according to the present invention;
• FIG. 2 is a cross-section taken through the contact ofFIG. 1;
• FIGS. 3 through 8 are schematic representations of a process for fabricating a substrate to be used in forming contacts of the present invention and, optionally, in forming probe cards that incorporate teachings of the present invention;
• FIG. 9 is a schematic representation of an exemplary stereolithography apparatus that may be used to form various structures of the present invention, including all or part of contacts, support plates of probe cards, and protective structures of the present invention;
• FIGS. 10A through 10C schematically illustrate a stereolithographic process for fabricating at least part of a contact of the present invention;
• FIGS. 11A through 11D schematically depict use of a wire-bonding capillary to form a contact according to the present invention;
• FIGS. 12 and 12A schematically illustrate contacts that have been coated with conductive material;
• FIGS. 13A and 13B depict the stereolithographic fabrication of a support plate of a probe card according to the present invention;
• FIG. 14 shows the support plate, contacts, and substrate being removed from a fabrication tank of a stereolithography apparatus;
• FIG. 15 schematically represents the assembly that results from fabrication of a support plate around the contacts that protrude from the substrate;
• FIG. 16 schematically illustrates removal of the contacts from the substrate on which they were fabricated;
• FIG. 17 is a partial perspective view of a semiconductor device or other semiconductor device component that includes contacts of the present invention secured to the bond pads or terminals thereof;
• FIG. 18 is a cross-sectional representation of the semiconductor device or other semiconductor device component ofFIG. 17;
• FIG. 19 is a schematic illustration of the manner in which a probe card may be assembled between a semiconductor device and a test or bum-in substrate;
• FIG. 20 is a partial perspective view of another exemplary embodiment of probe card that incorporates teachings of the present invention;
• FIGS. 21 through 26 are cross-sectional representations of an exemplary process for fabricating the probe card shown inFIG. 20;
• FIGS. 27 through 31 are schematic representations of various exemplary ends of probe card contacts according to the present invention;
• FIGS. 32 through 38 are schematic representations of another exemplary embodiment of a method for fabricating probe cards in accordance with teachings of the present invention; and
• FIGS. 39 through 41 are partial perspective views that illustrate exemplary embodiments of protective structures of the present invention, as well as the manner in which they may be positioned relative to contacts and the substrates from which contacts protrude.
DETAILED DESCRIPTION OF THE INVENTION
• FIGS. 1 and 2 illustrate an exemplary embodiment ofcontact10 according to the present invention. As shown, contact10 includes abase12, anintermediate section14 adjacent to base12, and atip16, which is adjacent to and located on an end ofintermediate section14 opposite frombase12.Base12 is configured to make electrical contact with a contact pad or circuit (not shown) of a semiconductor device (not shown) (e.g., a bare or packaged semiconductor die), whiletip16 is configured to establish electrical communication with a contact pad (not shown) of another semiconductor device component (e.g., a test substrate or bum-in substrate, another semiconductor device, a carrier substrate, etc.).
• Contact10 includes a core18 that may be formed from a dielectric material or a conductive material. A layer of conductive material, which is also referred to herein as a “conductive coating20,” covers at least portions of theexterior surface19 ofcore18 so as to facilitate the transmission of electrical signals alongcontact10.
• Core18 may have any suitable configuration known in the art. As such,core18 may be rigid or flexible. By way of example only, arigid core18 may be shaped as a point, a tip, a truncated cone or pyramid, a cup cross, or the like. Examples offlexible core18 shapes include structures with levered arms, such as those described in the FormFactor Patents, including without limitation U.S. Pat. No. 5,476,211, 5,772,451, 5,820,014, 5,832,601, 5,852,871, 5,864,946, 5,884,398, 5,912,046 and 5,998,228, the disclosures of which patents are hereby incorporated herein in their entireties by this reference. Of course, in addition to their configurations, the materials from whichcores18 are formed may also lend to their relative rigidity or flexibility.
• Conductive coating20 may include one or more layers of conductive material suitable for use in forming or coating electrical contacts of semiconductor devices or other electronic components. By way of example only,conductive coating20 may include one or more of a conductive layer, a barrier layer, and a noble layer.
• An exemplary embodiment of the manner in whichcontact10 may be fabricated is illustrated inFIGS. 3 through 16.
• FIG. 3 depicts a fabrication orsacrificial substrate100 with ahard mask layer102 thereon.Substrate100 may be a sacrificial substrate. Also,substrate100 may comprise a full or partial semiconductor (e.g., silicon, gallium arsenide, indium phosphide) wafer or a full or partial silicon-on-insulator (SOI) type substrate, such as a silicon-on-ceramic (SOC), silicon-on-glass (SOG), or silicon-on-sapphire (SOS) type substrate.Hard mask layer102 may comprise silicon nitride or any other material (e.g., silicon oxynitride, silicon oxide, etc.) that is useful for forming a hard mask oversubstrate100.
• Photoresist104 is disposed upon asurface103 ofhard mask layer102 and patterned, as known in the art (e.g., by exposing the same, through a reticle, to one or more appropriate wavelengths of radiation, then developing the same), to form aphotomask106.Photomask106 includesapertures108 through which regions ofhard mask layer102 may subsequently be exposed to one or more etchants which are suitable for removing the material ofhard mask layer102. The removal of material fromhard mask layer102 results in the formation of ahard mask110 withapertures112 formed therethrough, as shown inFIG. 4.
• Turning now toFIG. 5,apertures112 ofhard mask110 are located and configured to facilitate the subsequent formation ofrecesses114 of desired configuration insubstrate110. Of course, recesses114 may be formed, for example, by etchingsubstrate100 with one or more suitable etchants (isotropic or anisotropic), as known in the art. Eachrecess114, which will facilitate the formation of a base12 (FIGS. 1 and 2) of acontact10, has a configuration which will impartbase12 with a desired configuration.
• As shown inFIG. 6, anotherhard mask layer116 may be formed so as to cover at least the surfaces ofrecesses114.Hard mask layer116 may also cover the remaining portions ofhard mask layer102. Likehard mask layer102,hard mask layer116 may be formed from any material which is suitable for use as a hard mask in semiconductor device fabrication processes, including, without limitation, silicon nitride, silicon oxynitride, silicon oxide, and the like. Of course, the processes that are used to formhard mask layer116 depend upon the type of material to be used.
• Oncehard mask layer116 has been formed, asacrificial layer118 is formed thereover, as shown inFIG. 7. By way of example only,sacrificial layer118 may be formed from aluminum by use of sputtering processes. As another example,sacrificial layer118 may be formed from a photoresist, which may be applied tohard mask layer116 by spin-on processes, then cured by exposure to one or more appropriate wavelengths of radiation and development with suitable developing chemicals.
• Thereafter, as shown inFIG. 7, ifsacrificial layer118 is formed from a metallic material, such as aluminum, anoptional plating mask120 may be formed oversacrificial layer118. Platingmask120 is formed from a material that will not be plated assubstrate100 is exposed into electrolytic, electroless, or immersion plating chemicals and conditions. Thus, platingmask120 is formed over features onsubstrate100 that would otherwise be plated upon exposure to plating chemicals and conditions, such as regions of a metallicsacrificial layer118 that are not located withinrecesses114. Features that are to be plated, such as the portions of a metallicsacrificial layer118 that are located withinrecesses114, are exposed throughapertures122 of platingmask120 to facilitate their subsequent exposure to plating chemicals and conditions. By way of example only, platingmask120 may comprise a photomask, which is formed by disposing photoresist onsacrificial layer118, then selectively exposing (e.g., through a reticle) and developing the photoresist to cure the same.
• Turning now toFIG. 8, at least acore18 of a contact10 (FIGS. 1 and 2) may be formed within eachrecess114 by known processes.
• For example, as shown inFIGS. 9 and 10A through10C,core18 may be formed by stereolithographic processes, such as those described in U.S. Pat. No. 6,524,346 to Farnworth, assigned to the assignee of the present invention and the disclosure of which is hereby incorporated herein in its entirety by this reference. Such processes may be used to form core18 from a conductive material (e.g., a conductive polymer or conductive photopolymer) or from a dielectric material (e.g., a dielectric photopolymer).
• FIG. 9 schematically depicts an example of astereolithographic apparatus1000 that may be used to fabricatecores18, as well as several other components that embody teachings of the present invention.Stereolithographic apparatus1000 includes afabrication tank1100, amaterial consolidation system1200, amachine vision system1300, acleaning component1400, and amaterial reclamation system1500 that are associated withfabrication tank1100. The depictedstereolithographic apparatus1000 also includes asubstrate handling system1600, such as a rotary feed system or linear feed system available from Genmark Automation Inc. of Sunnyvale, Calif., for moving fabrication substrates (e.g., substrates100) from one system of the stereolithographic apparatus to another. Features of one or more of the foregoing systems may be associated with one ormore controllers1700, such as computer processors or smaller groups of logic circuits, in such a way as to effect their operation in a desired manner.
• Controller1700 may comprise a computer or a computer processor, such as a so-called “microprocessor,” which may be programmed to effect a number of different functions. Alternatively,controller1700 may be programmed to effect a specific set of related functions or even a single function. Eachcontroller1700 ofstereolithographic apparatus1000 may be associated with a single system thereof or a plurality of systems so as to orchestrate the operation of such systems relative to one another.
• Fabrication tank1100 includes achamber1110 which is configured to contain asupport system1130. In turn,support system1130 is configured to carry one ormore substrates100.
• Fabrication tank1100 may also have areservoir1120 associated therewith.Reservoir1120 may be continuous withchamber1110. Alternatively,reservoir1120 may be separate from, but communicate with,chamber1110 in such a way as to provideunconsolidated material1126 thereto.Reservoir1120 is configured to at least partially contain a volume1124 ofunconsolidated material1126, such as a photoimageable polymer, or “photopolymer,” particles of thermoplastic polymer, resin-coated particles, or the like.
• Photopolymers believed to be suitable for use with astereolithography apparatus1000 according to the present invention include, without limitation,ACCURA® SI 40 Hc and AR materials and CIBATOOL SL 5170 and SL 5210 resins for the SLA® 250/50HR andSLA® 500 systems,ACCURA® SI 40 ND material and CIBATOOL SL 5530 resin for the SLA® 5000 and 7000 systems, and CIBATOOL SL 7510 resin for the SLA® 7000 system. The ACCURA® materials are available from 3D Systems, Inc., of Valencia, Calif., while the CIBATOOL resins are available from Ciba Specialty Chemicals Company of Basel, Switzerland.
• Reservoir1120 or another component associated with one or both offabrication tank1100 andreservoir1120 thereof may be configured to maintain asurface1128 of a portion of volume1124 located withinchamber1110 at a substantially constant elevation relative tochamber1110.
• Amaterial consolidation system1200 is associated withfabrication tank1100 in such a way as to direct consolidatingenergy1220 intochamber1110 thereof, toward at least areas ofsurface1128 of volume1124 ofunconsolidated material1126 withinreservoir1120 that are located oversubstrate100. Consolidatingenergy1220 may comprise, for example, electromagnetic radiation of a selected wavelength or a range of wavelengths, an electron beam, or other suitable energy for consolidatingunconsolidated material1126.Material consolidation system1200 includes asource1210 of consolidatingenergy1220. If consolidatingenergy1220 is focused,source1210 or alocation control element1212 associated therewith (e.g., a set of galvanometers, including one for x-axis movement and another for y-axis movement) may be configured to direct, or position, consolidatingenergy1220 toward a plurality of desired areas ofsurface1128. Alternatively, if consolidatingenergy1220 remains relatively unfocused, it may be directed generally towardsurface1128 from a single, fixed location or from a plurality of different locations. In any event, operation ofsource1210, as well as movement thereof, if any, may be effected under the direction ofcontroller1700.
• Whenmaterial consolidation system1200 directs focused consolidatingenergy1220 towardsurface1128 of volume1124 ofunconsolidated material1126,stereolithographic apparatus1000 may also include amachine vision system1300.Machine vision system1300 facilitates the direction of focused consolidatingenergy1220 toward desired locations of features onsubstrate100. As withmaterial consolidation system1200, operation ofmachine vision system1300 may be proscribed bycontroller1700. If any portion ofmachine vision system1300, such as acamera1310 thereof, moves relative tochamber1110 offabrication tank1100, that portion ofmachine vision system1300 may be positioned so as provide a clear path to all of the locations ofsurface1128 that are located over eachsubstrate100 withinchamber1110.
• Optionally, one or both of material consolidation system1200 (which may include a plurality of mirrors1214) andmachine vision system1300 may be oriented and configured to operate in association with a plurality offabrication tanks1100. Of course, one ormore controllers1700 would be useful for orchestrating the operation ofmaterial consolidation system1200,machine vision system1300, andsubstrate handling system1600 relative to a plurality offabrication tanks1100.
• Cleaning component1400 ofstereolithographic apparatus1000 may also operate under the direction ofcontroller1700.Cleaning component1400 ofstereolithographic apparatus1000 may be continuous with achamber1110 offabrication tank1100 or positioned adjacent tofabrication tank1100. Ifcleaning component1400 is continuous withchamber1110, anyunconsolidated material1126 that remains on asubstrate100 may be removed therefrom prior to introduction of anothersubstrate100 intochamber1110.
• Ifcleaning component1400 is positioned adjacent tofabrication tank1100, residualunconsolidated material1126 may be removed from asubstrate100 assubstrate100 is removed fromchamber1110. Alternatively, anyunconsolidated material1126 remaining onsubstrate100 may be removed therefrom aftersubstrate100 has been removed fromchamber1110, in which case the cleaning process may occur as anothersubstrate100 is positioned withinchamber1110.
• Material reclamation system1500 collects excessunconsolidated material1126 that has been removed from asubstrate100 by cleaningcomponent1400, then returns the excessunconsolidated material1126 toreservoir1120 associated withfabrication tank1100.
• In use,controller1700, under control of computer-aided drafting (CAD) or stereolithography (.stl) programming, may orchestrate operation of various components ofstereolithographic apparatus1000 to fabricatecores18, as well as other features.FIGS. 10A through 10C depict an example of the manner in whichcores18 may be fabricated.
• With reference toFIG. 10A,substrate100 is positioned on asupport platen1112 withinchamber1110 offabrication tank1100. As depicted,substrate100 is submerged within volume1124 ofunconsolidated material1126 so thatunconsolidated material1126 fills recesses114.Support platen1112 is then raised such that the upper surface ofsubstrate100 is brought to about the same level as (i.e., coplanar with)surface1128 of volume1124.Unconsolidated material1126 withinrecesses114 may then be selectively consolidated to form aninitial layer18a of each core18 (FIG. 10C).
• Next, as shown inFIG. 10B,support platen1112 may be lowered within chamber1110 a distance that corresponds substantially to a thickness of anext layer18b(FIG. 10C) of each core18.Unconsolidated material1126 of substantially the same thickness then flows oversubstrate100 andlayer18a. Thereafter, selected regions of the newly formedlayer1127bofunconsolidated material1126 are at least partially consolidated to form or definelayer18bofcore18 therefrom.Layer18bis at least partially superimposed over, contiguous with, and mutually adhered to layer18a.
• Turning toFIG. 10C, these processes are repeated a number of times untilcore18 has been completely formed.
• When apparatus such as that shown inFIG. 9 are used to fabricatecores18, a number ofcores18 may be simultaneously manufactured as a plurality of superimposed contiguous, mutually adhered material layers.
• Another example of the manner in whichcore18 of acontact10 of the present invention may be fabricated is shown inFIGS. 11A through 11C. In this example,core18 may comprise a conductive material (e.g., gold, aluminum, etc.) and may be formed using a dispenseelement70, such as a wire-bonding capillary, such as in the manner described in the FormFactor Patents. Alternatively, the material ofcore18 may be dispensed with a needle, such as the type used to dispense underfill materials and other packaging materials. Of course, the use of other suitable methods for fabricatingcores18 ofcontacts10 according to the present invention are also within the scope of the present invention.
• InFIG. 11A, dispenseelement70 is positioned over arecess114 insubstrate100 and a core material introduced intorecess114 to form afirst portion18a′ of core18 (FIG. 8), which comprises at least a portion ofbase12 of contact10 (FIGS. 1, 2, and11B). Thereafter, dispenseelement70 may be raised to form a protrudingportion18b′ ofcore18, which forms part ofintermediate section14 of contact10 (FIGS. 1 and 2). Onceintermediate section14 has been formed, as shown inFIG. 11C, movement of dispenseelement70 may be momentarily ceased to facilitate formation of atip section18c′ which is enlarged relative tointermediate section14. Dispenseelement70 may again be raised to complete formation oftip16 ofcore18, as shown inFIG. 11D.
• Each core18 may then be plated or otherwise coated with conductive material to form aconductive coating20 thereon, as shown inFIG. 12.Conductive coating20 may be formed by way of known electrolytic, electroless, or immersion plating techniques. Ifcore18 is formed from a nonmetallic material, such as a dielectric photopolymer, it may be necessary to prepare or treat the surface ofcore18, as known in the art, prior to formingconductive coating20 thereon.Conductive coating20 may include one or more sublayers. For example, ifcore18 is formed from a dielectric material,conductive coating20 may include a conductive sublayer (e.g., a sublayer of copper, aluminum, etc.), as well as a barrier sublayer (e.g., a sublayer of nickel) and a noble sublayer (e.g., a sublayer of gold). As another example, ifcore18 comprises a conductive material,conductive coating20 may include a barrier sublayer and a noble sublayer. Platingmask120 prevents other features onsubstrate100 from being plated.
• As shown inFIGS. 13A through 15, a support plate130 (FIG. 15) may be formed aroundintermediate sections14 ofcontacts10. By way of example only, known stereolithographic processes may be used to fabricatesupport plate130, such as with the apparatus shown in and described with respect toFIG. 9.
• InFIG. 13A,substrate100, along withcontacts10 and all of the other features that have been formed therein and thereon, may be partially submerged beneath asurface202 of avolume200 of photopolymer, withtips16 and portions ofintermediate sections14 ofcontacts10 protruding abovesurface202.Surface202 may then be exposed to radiation of one or more wavelengths that are appropriate for at least partially polymerizing, or consolidating, the photopolymer atsurface202 to form alayer132aof support plate130 (FIG. 15). Preferably, such exposure is effected with focused radiation204 (e.g., a laser beam), which has a focal point that facilitates control of a depth T₁, to which the photopolymer is at least partially consolidated and, thus, a thickness oflayer132a.Further, by angling an energy beam used to exposesurface202 to radiation from a perpendicular orientation to expose thesurface202 undertip16, such consolidation may be effected so that at least portions of the outer peripheries ofbase12 andtip16 are superimposed over one or more portions oflayer132ato trapintermediate section14 ofcontact10 withinlayer132a.
• Oncelayer132ahas been formed,substrate100 andlayer132amay be submerged withinvolume200 of photopolymer a distance which corresponds to a thickness T₂of a next-higher layer132bof support plate130 (FIG. 15), as shown inFIG. 13B. The process described in reference toFIG. 13A may then be repeated to formlayer132bofsupport plate130, withlayer132bbeing at least partially superimposed over, contiguous with, and mutually adhered to the previously formedlayer132a. This process may be repeated until asupport plate130 of desired thickness has been formed.
• After eachlayer132a,132b, etc. ofsupport plate130 has been formed,substrate100,contacts10, andsupport plate130 may be removed fromvolume200 of photopolymer, as shown inFIG. 14. Thereafter, the material oflayers132a,132b, etc. may be further consolidated by exposing the same to energy or radiation (not shown), such as nonfocused radiation of one or more curing wavelengths, heat, or another suitable form of energy or radiation, as known in the art. Once fabrication ofsupport plate130 is complete, as shown inFIG. 15,support plate130 andcontacts10 extending therethrough form a probe card30 (see alsoFIG. 19). Optionally,support plate130 may be formed as a large panel and severed after fabrication thereof into smaller segments to form a plurality ofprobe cards30.
• Turning now toFIG. 16, an example of the manner in whichcontacts10 may be freed fromsubstrate100 is shown. Sacrificial layer118 (FIG. 15) and, optionally, plating mask120 (FIG. 15) may be removed by known processes. Ifsacrificial layer118 is formed from aluminum, one or more suitable etchants (e.g., tetramethyl ammonium hydroxide (TMAH), potassium hydroxide (KOH), sodium hydroxide (NaOH), etc., or any combination thereof) may be used to dissolve or otherwise remove the aluminum. If a photoresist was used to formsacrificial layer118,sacrificial layer118 may be exposed to a resist strip suitable for dissolving or otherwise removing the photoresist. Whensacrificial layer118 is removed, overlying structures are “lifted-off” ofsubstrate100. Thus, bases12 ofcontacts10 are no longer anchored withinrecesses114 and may be removed therefrom.Substrate100 may then be discarded. Alternatively,substrate100 may again be used in the processes described with reference toFIGS. 6 through 16 to formadditional contacts10.
• As an alternative to the process shown inFIGS. 3 through 16,Contacts10 according to the present invention may be fabricated without formingrecesses114 in asacrificial substrate100. Instead, as shown inFIGS. 3A, 6A, and7A,substrate100 may merely be coated with a hard mask layer102 (FIG. 3A), asacrificial layer118 formed thereover (FIG. 6A), and platingmask120 formed over selected regions (i.e., those wherecontacts10 are not to be formed) of sacrificial layer118 (FIG. 7A).Contacts10 may then be formed by the processes that have been described in reference toFIGS. 8 through 16. Of course, when nonstereolithographic processes are used to formcores18, the areas ofcores18 which are formed on exposed regions ofsacrificial layer118 may be flat, or planar. In addition, the shape of each core18, atbase12 ofcontact10, may be limited by the process and materials that are used to form thatcore18.
• Referring now toFIGS. 17 and 18, if the substrate upon whichcontacts10 are to be fabricated is not a fabrication or sacrificial substrate but, rather, asubstrate100′ that carries one ormore semiconductor devices208 or other semiconductor device components (e.g., interposers),contacts10 may instead be formed directly oncontact pads210 of thesemiconductor devices208 or other semiconductor device components, such as by the above-described processes. By way of example only, the processes that are depicted in and described with reference toFIGS. 7 through 12 may be used to formcontacts10 directly oncontact pads210 of one ormore semiconductor devices208 or other semiconductor device components. Of course, as shown inFIG. 18, if acore18 of eachcontact10 comprises a dielectric material,conductive coating20 must provide a conductive path from thecorresponding contact pad210, alongbase12 andintermediate section14 ofcontact10, and ontotip16 thereof.
• The present invention also includes probe cards, as well as methods for fabricating probe cards. As depicted inFIG. 19 aprobe card30 may be positioned between one ormore semiconductor devices40 and a test or bum-insubstrate50.Contacts10 ofprobe card30 are located so as to align betweenbond pads42 of eachsemiconductor device40 andcorresponding terminals52 of a test or bum-insubstrate50 which is configured for use withsemiconductor device40. Eachcontact10 ofprobe card30 is configured to temporarily establish electrical communication between itscorresponding bond pad42 and terminal52 as one or both ofsemiconductor device40 and test or burn-insubstrate50 is biased toward the other. In this fashion,probe card30 facilitates the testing or burning-in of one ormore semiconductor devices40 with appropriate test or bum-in equipment (not shown) with which test or bum-insubstrate50 has been assembled.
• One example of aprobe card30 according to the present invention is shown inFIG. 15. Another example ofprobe card30′ that incorporates teachings of the present invention is depicted inFIG. 20. In addition to includingcontacts10,10′, aprobe card30,30′ according to the present invention may include circuit traces (not shown) on one or both sides thereof. Such circuit traces may be fabricated by known processes (e.g., mask and etch processes, use of stereolithography techniques, a so-called micropen and conductive ink, etc.).
• FIGS. 21 through 26 illustrate one embodiment of a method for fabricatingprobe card30′, whileFIGS. 32 through 38 depict another embodiment of a method by whichprobe card30′ may be fabricated.
• As shown inFIG.20,probe card30′ includes asupport plate130′ withmajor surfaces133′ and134′ that face opposite directions. Apertures131′ (FIG. 22) are formed throughsupport plate130′ at locations which correspond to the locations of bond pads42 (FIG. 19) and terminals52 (FIG. 19), respectively, on semiconductor devices40 (FIG. 19) and test or bum-in substrates50 (FIG. 19) with whichprobe card30′ is configured to be used. Acontact10′ extends through each aperture131′ ofsupport plate130′ , with oneend23′ that protrudes fromsurface133′ and anotherend24′ that protrudes fromsurface134′.
• With reference toFIG.26, eachcontact10′ includes anouter shell20′ which includes achannel21′ extending substantially centrally through the length, or height, thereof. As shown,channel21′ may contain a quantity of conductive material, which forms aconductive core18′ that extends through the entire length ofouter shell20′.
• Outer shell20′ may be rigid or flexible, depending at least in part upon the configuration thereof and the materials that are used to form the same. Also, the material or materials from whichouter shell20′ is fabricated may be dielectric or electrically conductive. As illustrated,outer shell20′ includes twocollars25′ and26′, which extend radially from the remainder (e.g., abody22′) ofouter shell20′ and are positioned so as to be located adjacent toopposite surfaces133′ and134′, respectively, ofsupport plate130′ (FIG. 20).
• As depicted, the ends ofconductive core18′ may be enlarged at ends23′ and24′ ofcontact10′ and extend onto portions ofouter shell20′ that are located at ends23′ and24′. A base12′ of each core18′ and, thus, ofcontact10′ of whichcore18′ is a part establishes electrical communication with a correspondingterminal52 of test or bum-in substrate50 (FIG. 19), while atip16′ of eachcontact10′ establishes electrical communication with acorresponding bond pad42 of a semiconductor device40 (FIG. 19) to be tested or burned-in. While the connection betweenbase12′ and terminal52 may be temporary (e.g., by biasingbase12′ against terminal52) or permanent (e.g., by bondingbase12′ to terminal52), it is currently preferred that the connection betweentip16′ andbond pad42 be temporary (e.g., by biasingtip16′ against bond pad42).
• Turning now toFIGS. 21 through 26, an exemplary method for fabricatingprobe card30′ andcontacts10′ thereof is depicted.
• InFIG. 21, asubstrate300 is provided.Substrate300 may be a substantially planar member, as depicted, or have any other suitable shape. Moreover,substrate300 may be formed from a variety of suitable materials, including, without limitation, polymers, metals, dielectric materials (e.g., glass, ceramic, etc.), semiconductor materials (e.g., silicon, gallium arsenide, indium phosphide, etc.), or any combination of the foregoing. Specific examples of structures that may be employed assubstrate300 include full or partial wafers of semiconductor material and full or partial SOI-type substrates.
• Turning toFIG. 22,apertures310 are formed throughsubstrate300 at locations wherecontacts10′ (FIG. 20) are to be located.Apertures310 may be formed by any process which is suitable for use with the material ofsubstrate300. By way of example only,apertures310 may be formed throughsubstrate300 by known drilling techniques (e.g., laser drilling, mechanical drilling, etc.). Alternatively, mask and etch processes may be used to formapertures310 through desired locations ofsubstrate300.
• Ifsubstrate300 comprises a conductive or semiconductive material, surfaces312 ofapertures310 may be coated with alayer314 of dielectric material, as shown inFIG. 23.Layer314 of dielectric material may likewise extend onto all or part ofsurfaces302 and304 ofsubstrate300. In addition to passivatingsurfaces312,302,304,layer314 may facilitate adhesion of subsequently formed structures tosubstrate300. By way of example only,layer314 may comprise silicon oxide, silicon nitride, or silicon oxynitride and may be formed by any suitable process known in the art (e.g., silicon oxide may be grown, spun-on, or deposited; silicon nitride and silicon oxynitride may be deposited).
• As shown inFIG. 24, at least portions of contacts may be formed within at least someapertures310 ofsubstrate300. For example and as illustrated inFIG. 24, anouter shell20′ of acontact10′ (FIG. 26) may be formed within eachaperture310.Outer shell20′ may comprise a dielectric material (e.g., a dielectric photopolymer) and may be fabricated by known stereolithography processes, such as those described above in reference toFIGS. 13A through 15. Asouter shell20′ may includecollars25′ and26′ that are to be positioned adjacentopposite surfaces302 and304 ofsubstrate300, theportion20a′ ofouter shell20′ that protrudes fromsurface302 may be fabricated, thensubstrate300 flipped, or inverted, so that theremainder20b′ ofouter shell20′, which protrudes fromsurface304 ofsubstrate300, may be fabricated.
• Outer shell20′ may be fabricated with achannel21′ extending therethrough, orchannel21′ may be subsequently formed therethrough by known processes (e.g., with a laser drill, mechanical drill, etc.). Optionally,channel21′ may be formed during the fabrication ofouter shell20′ , then bored to increase one or more cross-sectional dimensions (e.g., radius and circumference) thereof.
• Next, as depicted inFIG. 25,conductive material316 is introduced intochannel21′ . By way of example only, needle-dispense processes may be used to introduceconductive material316 intochannel21′ orconductive material316 may be introduced intochannel21′ using a pressurized wire-bonding capillary. If needle dispense processes are used, a conductive or conductor-filled polymer may be introduced intochannel21′, then cured by suitable processes (e.g., exposure to an appropriate wavelength of radiation, heat, etc.). When a wire-bonding capillary is used to force, under positive pressure, a molten metal (e.g., gold, copper, aluminum, etc.) intochannel21′, the metal will harden upon being cooled. Of course, the material from whichouter shell20′ is formed should be able to withstand the temperature of the molten metal ofconductive material316, as well as substantially maintain its structural integrity when exposed to the molten metal.
• As a result of introducingconductive material316 intochannel21′, aconductive element320 is formed therein.Conductive element320 includes afirst end323, which is exposed at and may protrude fromend23′ ofcontact10′, and asecond end324, which is exposed at and may protrude fromend24′ ofcontact10′.
• FIG. 26 depicts the formation of acap325,326 at each end23′,24′ ofcontact10′ from ends323 and324 (FIG. 25), respectively, ofconductive element320, which may complete the formation ofcore18′ ofcontact10′. Whenconductive element320 comprises a conductive or conductor-filled polymer, caps325 and326 may be formed prior to curing or solidifying conductive material316 (FIG. 25), as the at least partially liquidconductive material316 flows onto ends ofouter shell20′. Ifconductive material316 comprises metal, caps325 and326 may be formed by heating ends323 and324 ofconductive element320 to a molten state and permitting them to flow onto the ends ofouter shell20′.
• Additionally, as shown inFIGS. 29 and 30, one or both ends323,324 of conductive element320 (FIG. 26) may be drawn, by known techniques, so as to form an extension (e.g.,extension328 ofFIG. 29 orextension328′ ofFIG. 30) fromcore18′ (FIG. 26), which extension protrudes fromouter shell20′,20″ ofcontact10′ ,10″, repectively. Alternatively, one or more extensions (e.g.,extensions328,328′) may be formed separately fromcore18′. By way of example only, a wire-bonding capillary may be used to draw or form each extension.
• As an alternative to the use of dielectric material to form anouter shell20′, electricallyconductive contacts10′″ may be formed within at least someapertures310 ofsubstrate300, as shown inFIG. 24. As an example, stereolithography processes, such as those described above in reference toFIGS. 13A through 15, may be used to formcontacts10 from conductive material, such as a conductive or conductor-filled photopolymer.
• As another alternative, thermoplastic material may be sprayed, or “jetted,” ontosubstrate300 layer-by-layer. Examples of such processes are described in U.S. Pat. No. 6,532,394, 6,508,971, 6,492,651, 6,490,496, 6,406,531, 6,352,668, 6,347,257, 6,305,769, 6,270,335, 6,193,923, 6,133,355, 5,340,433, 5,260,009, 5,216,616, 5,141,680, 5,134,569, 5,121,329, and 4,665,492, the disclosures of each of which are hereby incorporated herein in their entireties by this reference. Additional examples of such processes are described in Grimm, Todd, “Stereolithography, Selective Laser Sintering and PolyJet™: Evaluating and Applying the Right Technology,” Pamphlet produced by Accelerated Technologies, Inc. of Austin, Tex. (2002), and in the pamphlet entitled “PolyJet 2^ndGeneration Technology,” which was produced by Objet Geometries Ltd. of Rehovot, Israel, in 2003, the disclosures of both of which are hereby incorporated herein, in their entireties, by this reference.
• Of course, when aconductive contact10″ is formed directly within one ormore apertures310 ofsubstrate300, it may not be necessary to form a core of another conductive material therein, although doing so (e.g., by the processes described above with reference toFIGS. 24 through 26) is within the scope of the present invention.
• FIGS. 27 through 31 illustrate examples of different configurations of contacts (e.g.,contacts10′,10″) according to the present invention.
• Another exemplary embodiment of a method for fabricating aprobe card30′ (FIG. 20) in accordance with teachings of the present invention is depicted inFIGS. 32 through 38.
• InFIG. 32, conductive elements418 (only one being shown) are formed on asubstrate400. Eachconductive element418 is a substantially linear structure which protrudes fromsubstrate400 and which is secured to asurface402 thereof with abonding joint416. Any suitable, known process may be used to formconductive elements418. For example, and not to limit the scope of the present invention,bonding joints416 andconductive elements418 may be formed with a wire-bonding capillary.
• Next, as shown inFIG. 33, aportion20a′ of anouter shell20′ (FIG. 26) is formed around anintermediate section419 of eachconductive element418.Portions20a″ may be formed by stereolithography processes, such as those which have been described above in reference toFIGS. 13 through 15.
• As depicted, eachportion20a′ includes a protrudingelement27′, acollar25′, and a taperedalignment element29′. Protrudingelement27′ is an elongate member which may be cylindrical in shape.Collar25′ is located adjacent to protrudingelement27′ and extends outwardly (e.g., radially) therefrom.Alignment element29′, which may be frustoconical in shape, is positioned adjacent tocollar25′ and on an opposite side thereof from protrudingelement27′. Althoughalignment element29′ is depicted as abuttingcollar25′, it may be spaced apart therefrom by a section ofportion20a′ which has a reduced cross section relative tocollar25′ andalignment element29′.
• Thereafter, as illustrated inFIG. 34, asubstrate300 through whichapertures310 have already been formed (see, e.g.,FIG. 22 and accompanying text) is positioned oversubstrate400, withapertures310 being aligned overconductive elements418 andportions20a′ ofouter shells20′ that have been formed thereon. Such alignment may be effected in any suitable manner known in the art, e.g., mechanically, optically, or otherwise.
• Oncesubstrate300 has been properly positioned, withalignment elements29′ of eachportion20a′ being at least partially disposed within a correspondingaperture310 and a portion of eachconductive element418 extending through the correspondingaperture310 ofsubstrate300, aremainder20b′ of eachouter shell20′ may be fabricated, as illustrated inFIG. 35. As shown, eachremainder20b′ extends partially intoaperture310 and includes features, such as the depictedcollar26′ and protrudingelement28′, which protrude fromsurface302 ofsubstrate300. By way of example only, known stereolithography processes, such as those described with respect toFIGS. 13 through 15, may be used to form eachremainder20b′ and, thus, to complete the formation of each correspondingouter shell20′.
• FIG. 36 shows that, if desired,conductive elements418 may be bent. Such bending may be effected, for example, by moving one or both ofsubstrate300 andsubstrate400 relative to the other, as indicated byarrows350,352.
• Onceouter shells20′ have been fabricated, as depicted inFIG. 37, bonding joints416 may be removed from substrate400 (e.g., by heating at least bonding joints416) orconductive elements418 severed (e.g., cut) to facilitate the removal ofsubstrate400 from the remainder of the assembly.
• AsFIG. 38 illustrates, acap425,426 may then be formed at each end23′,24′ ofcontact10′ from ends423 and424 (FIG. 36), respectively, ofconductive element418, which may complete the formation ofcore18′ ofcontact10′. As an example of the manner in which caps425 and426 may be formed, ends423 and424 ofconductive element418 may be heated to a molten state and permitted to flow onto the ends ofouter shell20′.
• Optionally, one or both ends323,324 ofconductive element320 may be drawn, by known techniques, in such a way as to form an extension (e.g.,extension328 ofFIG. 29 orextension328′ ofFIG. 30) fromcore18′, which extension protrudes fromouter shell20′ ofcontact10′. Alternatively, one or more extensions may be formed separately fromcore18′. By way of example only, a wire-bonding capillary may be used to draw or form each extension.
• At some point during the process that has been described with reference toFIGS. 32 through 38, and with returned reference toFIG. 36, alayer420 of conductive material may be formed on exposed portions of eachconductive element418.Layer420 may comprise a single layer or a plurality of sublayers (e.g., a barrier sublayer, a noble sublayer, etc.), each of which may, by way of nonlimiting example, be formed by way of known plating processes.Layer420 may impart some rigidity toconductive element418, providing some resilience whenconductive element418 is compressed or otherwise flexed. Alternatively, or additionally,layer420 may prevent oxidation or corrosion ofconductive element418.
• Such plating may be effected just after the formation of conductive elements418 (FIG. 32), following the bending, if any, of conductive elements418 (FIG. 35), or at any other suitable point during the fabrication of aprobe card30 in accordance with the processes ofFIGS. 32 through 37.
• In another aspect, the present invention includes protective structures that are configured to prevent damage to a contact (e.g., contact10,10′) of the present invention.FIGS. 39 through 41 depict exemplary embodiments ofprotective structures500,500′, and500″, respectively, that incorporate teachings of the present invention.
• The embodiment ofprotective structure500 shown inFIG. 39 comprises amaterial layer501 that is secured to a surface of a substrate, illustrated merely as an example as being aprobe card30.Contacts10 may protrude a greater distance from asurface32 ofprobe card30 than the distance thatlayer501 protrudes fromsurface32. As shown, a plurality ofreceptacles510 are formed inmaterial layer501, within which portions ofcontacts10 are located.Surfaces512 of eachreceptacle510 may be spaced apart from thecontact10 therein so as to permit some compression or flexion ofcontact10, while preventingcontact10 from being compressed or flexed beyond its elastic limit, which is largely dependent upon the material or materials from whichcontact10 has been fabricated. The thickness ofmaterial layer501 when subjected to compressive loading may also prevent eachcontact10 from being compressed or flexed beyond its elastic limit.
• Another exemplary embodiment ofprotective structure500′ is shown inFIG. 40. Eachprotective structure500′ is a cup-shaped structure that includes awall501′ and asingle receptacle510′ formed within the interior ofwall501′. As depicted,protective structure500′ is located on a surface of a substrate (asemiconductor device40 in the depicted example), withreceptacle510′ laterally surrounding at least a portion of acontact10 that protrudes from abond pad42 ofsemiconductor device40. As withprotective structure500,surfaces512′ ofreceptacle510′ may be spaced apart from thecontact10 therein so as to permit some compression or flexion ofcontact10, while preventingcontact10 from being compressed or flexed beyond its elastic limit. The distance eachprotective structure500′ protrudes from the substrate when subjected to compressive loading may also prevent eachcontact10 from being compressed or flexed beyond its elastic limit.
• FIG. 41 illustrates yet another exemplary embodiment ofprotective structure500″. Eachprotective structure500″ comprises a post-like structure or other element which protrudes from a surface of a substrate, such as the depicted carrier substrate60 (e.g., an interposer, circuit board, etc.) at a location which is adjacent to aterminal62 ofcarrier substrate60 and, thus, proximate to the location at which acontact10 protrudes fromcarrier substrate60. The heights ofprotective structures500″ are configured to preventcontacts10 from being compressed or flexed under compressive forces beyond their elastic limits.
• Each of the foregoing embodiments ofprotective structures500,500′,500″, as well as other embodiments of protective structures that are within the scope of the present invention, may be fabricated by stereolithography processes, such as those described herein with reference toFIGS. 13A through 15. As such, a protective structure of the present invention may include a plurality of at least partially superimposed, contiguous, mutually adhered layers of material. All of the layers may be formed from the same material, or a variety of materials (e.g., materials with different degrees of compressibility or flexibility and resilience) may be used, depending at least in part upon the desired properties of the protective structure. Of course, other suitable techniques may also be used to form protective structures that incorporate teachings of the present invention.
• Protective structures according to the present invention may be fabricated directly on a substrate, or fabricated separately from the substrate, then secured thereto (e.g., with a suitable adhesive material).
• Although the foregoing description contains many specifics, these should not be construed as limiting the scope of the present invention, but merely as providing illustrations of some of the presently preferred embodiments. Similarly, other embodiments of the invention may be devised which do not depart from the spirit or scope of the present invention. Moreover, features from different embodiments of the invention may be employed in combination. The scope of the invention is, therefore, indicated and limited only by the appended claims and their legal equivalents, rather than by the foregoing description. All additions, deletions, and modifications to the invention, as disclosed herein, which fall within the meaning and scope of the claims are to be embraced thereby.

Claims (54)

1. A method for forming a contact for a semiconductor device component, comprising:

fabricating a core of the contact by selectively consolidating material in accordance with a program; and

coating at least a portion of the core with at least one layer comprising conductive material.

2. The method ofclaim 1, wherein fabricating comprises:

directing consolidating energy or radiation toward unconsolidated material.

3. The method ofclaim 2, wherein directing comprises directing the consolidating energy or radiation toward unconsolidated material comprising uncured photoimagable polymer.

4. The method ofclaim 1, wherein fabricating comprises stereolithographically fabricating the core.

5. The method ofclaim 4, wherein fabricating comprises:

forming at least one layer comprising unconsolidated material; and

at least partially consolidating selected regions of the at least one layer.

6. The method ofclaim 5, further comprising:

repeating forming the at least one layer and the at least partially consolidating at least once.

7. The method ofclaim 1, wherein fabricating comprises fabricating the core to include at least a portion which is flexible and resilient.

8. The method ofclaim 1, wherein fabricating comprises fabricating the core to include an enlarged contact tip.

9. The method ofclaim 1, wherein coating comprises substantially coating the core with the conductive material.

10. The method ofclaim 1, wherein coating comprises forming a seed layer on at least the portion of the core.

11. The method ofclaim 10, wherein forming the seed layer comprises at least one of chemical vapor deposition and physical vapor deposition.

12. The method ofclaim 10, wherein coating further comprises forming at least one additional layer comprising conductive material over the seed layer.

13. The method ofclaim 12, wherein forming the at least one additional layer comprises at least one of chemical vapor deposition, physical vapor deposition, electrolytic plating, electroless plating, and immersion plating.

14. The method ofclaim 12, wherein forming the at least one additional layer comprises:

forming a conductive layer; and

forming an oxidation-resistant layer over the conductive layer.

15. The method ofclaim 14, wherein forming the at least one additional layer further comprises:

forming a barrier layer between the conductive layer and the oxidation-resistant layer.

16. A method for forming a contact for a semiconductor device component, comprising fabricating at least a portion of the contact by a programmed material consolidation process.

17. The method ofclaim 16, wherein fabricating comprises selectively consolidating unconsolidated material in accordance with a program.

18. The method ofclaim 17, wherein selectively consolidating comprises directing focused energy or radiation toward the unconsolidated material.

19. The method ofclaim 16, wherein fabricating comprises fabricating the at least one layer from a dielectric material.

20. The method ofclaim 16, further comprising forming a conductive coating on at least a portion of an exterior surface of a core formed during the act of fabricating.

21. The method ofclaim 18, wherein fabricating comprises fabricating at least the portion from a conductive material.

22. The method ofclaim 21, wherein fabricating comprises fabricating at least the portion from at least one of a conductive polymer and a conductor-filled polymer.

23. The method ofclaim 16, wherein fabricating comprises stereolithographically fabricating.

24. A contact of a semiconductor device component, comprising a plurality of at least partially superimposed, contiguous, mutually adhered layers.

25. The contact ofclaim 24, wherein the plurality of at least partially superimposed, contiguous, mutually adhered layers form at least part of a conductive portion of the contact.

26. The contact ofclaim 25, wherein each layer of the plurality of at least partially superimposed, contiguous, mutually adhered layers comprises at least one of a conductive polymer and a conductor-filled polymer.

27. The contact ofclaim 25, further including a core that at least partially supports the conductive portion.

28. The contact ofclaim 27, wherein the core includes a plurality of at least partially superimposed, contiguous, mutually adhered layers.

29. The contact ofclaim 28, wherein the plurality of at least partially superimposed, contiguous, mutually adhered layers of the core comprises dielectric material.

30. The contact ofclaim 24, wherein each layer of the plurality of at least partially superimposed, contiguous, mutually adhered layers comprises a dielectric material.

31. The contact ofclaim 30, wherein the dielectric material comprises photopolymer.

32. The contact ofclaim 30, wherein the plurality of at least partially superimposed, contiguous, mutually adhered layers form at least a portion of a core of the contact.

33. The contact ofclaim 31, further including a conductive coating on at least a portion of an exterior surface of the core.

34. A contact of a semiconductor device component, comprising a plurality of adjacent, mutually adhered regions.

35. The contact ofclaim 34, wherein the plurality of adjacent, mutually adhered regions form at least part of a conductive portion of the contact.

36. The contact ofclaim 35, wherein each layer of the plurality of adjacent, mutually adhered regions comprises at least one of a conductive polymer and a conductor-filled polymer.

37. The contact ofclaim 35, further including a core that at least partially supports the conductive portion.

38. The contact ofclaim 37, wherein the core includes a plurality of adjacent, mutually adhered regions.

39. The contact ofclaim 38, wherein the plurality of adjacent, mutually adhered regions of the core comprises dielectric material.

40. The contact ofclaim 34, wherein each region of the plurality of adjacent, mutually adhered regions comprises a dielectric material.

41. The contact ofclaim 40, wherein the dielectric material comprises photopolymer.

42. The contact ofclaim 40, wherein the plurality of adjacent, mutually adhered regions form at least a portion of a core of the contact.

43. The contact ofclaim 42, further including a conductive coating on at least a portion of an exterior surface of the core.

44. A contact for use with an electronic device component, comprising:

a flexible, resilient core including a plurality of adjacent, mutually adhered layers; and

a conductive coating on the core.

45. The contact ofclaim 44, further comprising a protective element protruding adjacent thereto, the protective element being configured to limit compression of the core of the contact.

46. A method for protecting flexible, resilient contacts that protrude from at least one of surface of a substrate, comprising disposing a protective structure on the at least one surface laterally adjacent to each flexible, resilient contact that protrudes from the at least one surface, the protective structure:

having a height which at least partially prevents an adjacent flexible, resilient contact from being deformed beyond its elastic limit; or

being spaced apart from the adjacent flexible, resilient contact a distance which at least partially prevents the adjacent flexible, resilient contact from being deformed beyond the elastic limit.

47. The method ofclaim 46, wherein disposing comprises forming the protective structure on the at least one surface.

48. The method ofclaim 46, wherein disposing comprises securing a preformed protective structure to the at least one surface.

49. The method ofclaim 46, further comprising forming the protective structure.

50. The method ofclaim 49, wherein forming comprises selectively consolidating unconsolidated material in accordance with a program.

51. The method ofclaim 50, wherein selectively consoliding unconsolidated material in accordance with a program comprises stereolithographically forming the protective structure.

52. The method ofclaim 46, wherein disposing comprises disposing a substantially planar protective structure on the at least one surface, the substantially planar protective structure including a plurality of apertures therethrough, at least some contacts of the flexible, resilient contacts being at least partially disposed within corresponding apertures of the plurality of apertures and at least partially laterally surrounded by the substantially planar protective structure.

53. The method ofclaim 46, wherein disposing comprises disposing an individual protective structure around at least one flexible, resilient contact of the flexible resilient contacts, the individual protective structure including:

an aperture therethrough within which the at least one flexible, resilient contact is at least partially disposed; and

a side wall that at least partially laterally surrounds the at least one flexible, resilient contact.

54. The method ofclaim 46, wherein disposing comprises disposing at least one element adjacent to at least one flexible, resilient contact of the flexible, resilient contacts so as to protrude from the at least one surface.

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