Cleaning device for cleaning probe tips

Abstract

A cleaning device for cleaning probe tips is provided. The cleaning device comprises a substrate having upper and lower surfaces, and a cleaning material attached thereto having upper and lower surfaces. The cleaning material comprises a first phase comprising a first cleaning substance and a second phase comprising a second cleaning substance. The first phase is disposed within the cleaning material in one or more first domains extending from the upper surface to the lower surface of the cleaning material. The second phase is disposed within the cleaning material in one or more second domains extending from the upper surface to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains. The first and second cleaning substances differ regarding a cleaning property. The upper surface of the cleaning material has a flatness tolerance of less than 50 microns.

Description

CLEANING DEVICE FOR CLEANING PROBE TIPSFIELD OF THE INVENTION

[0001] The present invention relates generally to a cleaning device for cleaning probe tips, and more particularly to a cleaning device for cleaning probe tips comprising: (a) a substrate having an upper surface and a lower surface; and (b) a cleaning material having an upper surface and a lower surface; wherein the cleaning material is attached to the substrate; the cleaning material comprises (i) a first phase comprising a first cleaning substance and (ii) a second phase comprising a second cleaning substance; the first phase is disposed within the cleaning material in one or more first domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material; the second phase is disposed within the cleaning material in one or more second domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains; the first cleaning substance differs from the second cleaning substance with respect to at least one cleaning property; and the upper surface of the cleaning material has a flatness tolerance of less than 50 microns across the upper surface.BACKGROUND OF THE INVENTION

[0002] Wafer probing is an important step in the manufacture of wafers for integrated circuits. During the process of wafer probing, probe pads are used to test integrated circuits on wafers, and probe tips of probe cards are used to test the probe pads. Probe tips undergo numerous touchdowns onto probe pads during this process. Debris from the probe pads accumulates on the probe tips, impeding optimal electrical contact and potentially compromising test results. Moreover, the repetitive probe-to-pad interactions result in the build-up and accumulation of various contaminants that interfere with the electrical contact reliability and affect the probe-to-pad alignment. These challenges directly impact contact resistance (also termed CRES) during testing, potentially resulting in artificially low wafer yield. Thus, ensuring proper maintenance and regular cleaning of probe tips is essential to sustain consistently low and stable contact resistance and acceptable overall wafer yield, as well as to reduce downtime due to operator assist.

[0003] Effective wafer testing is contingent on the ability to clean and maintain the shape of the probe tips. Tacky, elastomeric cleaning polymer compositions, such as those of Gel-Pak's REMOVE and REFINE products, are able to gently remove loose and adherent debris onprobe tips. Cleaning polymer compositions are less efficient in maintaining the flatness of the probe tips, though. Hard abrasive materials, such as lapping films and lapping substrates, are able to remove bond pad debris and flatten and texturize probe tips. Hard abrasive materials are aggressive and wear the probe tips quickly, though, thus decreasing probe tip longevity. Hard abrasive materials also can leave behind significant debris, which can interfere with optical systems of probers.

[0004] A two-step cleaning process is often implemented, where probe tips are cleaned with a hard abrasive material to maintain the shape of probe tips, and with a cleaning polymer composition to gently polish probe tips and remove accumulated debris. This two-step process increases cleaning time and complexity, for example by requiring removal of a first cleaning device used in the first step from a wafer chuck and loading of a second cleaning device used in the second step into the wafer chuck in order to carry out both steps, thus increasing the overall wafer cost of testing.

[0005] U.S. Pat. No. 6,840,374 discloses a probe cleaning apparatus for cleaning a probe tip used to test semiconductor dies having an abrasive substrate layer and a tacky gel layer on top of the abrasive surface of the abrasive substrate layer. According to U.S. Pat. No. 6,840,374, the probe cleaning apparatus can be spooled. According to U.S. Pat. No. 6,840,374, the probe tip is cleaned by passing it through the tacky gel layer so that it comes in contact with the abrasive surface of the abrasive substrate, moving the probe tip across the abrasive surface of the substrate layer, and then removing the probe tip from the successive layers of the cleaning apparatus. According to U.S. Pat. No. 6,840,374, the probe tip emerges from the cleaning apparatus free from debris associated with testing the semiconductor dies.

[0006] FIG. 3 of U.S. Pat. No. 6,840,374 shows a spooled cleaning pad composed of alternating regions of tacky gel material and abrasive substrate at the surface of the cleaning pad. As shown in FIG. 3 of U.S. Pat. No. 6,840,374, the tacky gel material is laminated on top of the abrasive substrate and raised above the surface of the abrasive substrate. As taught by U.S. Pat. No. 6,840,374, this allows the probe tips to be brought in contact with the tacky gel layer, subjected to movement in the X-plane, removed from the tacky gel layer, brought in contact with surface abrasions of the abrasive substrate, moved in the X-direction, and removed from the surface of the abrasive substrate. As taught by U.S. Pat. No. 6,840,374, the cleaning features are on a macroscopic scale, with distinct material zones large enough to accommodate multiple probe tips and allow for repeated cleaning cycles across different regions of the spooled cleaning pad. Although U.S. Pat. No. 6,840,374 teaches a spooledcleaning pad as discussed above, to the inventors’ knowledge no such spooled cleaning pad has been implemented in a prober.

[0007] A need exists for improved devices and methods for regular cleaning and proper maintenance of probe tips that effectively remove debris from probe tips while also maintaining flatness and roughness of the probe tip.BRIEF SUMMARY OF THE INVENTION

[0008] A cleaning device for cleaning probe tips is provided. The cleaning device comprises: (a) a substrate having an upper surface and a lower surface; and (b) a cleaning material having an upper surface and a lower surface. The cleaning material is attached to the substrate. The cleaning material comprises (i) a first phase comprising a first cleaning substance and (ii) a second phase comprising a second cleaning substance. The first phase is disposed within the cleaning material in one or more first domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material. The second phase is disposed within the cleaning material in one or more second domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains. The first cleaning substance differs from the second cleaning substance with respect to at least one cleaning property. The upper surface of the cleaning material has a flatness tolerance of less than 50 microns across the upper surface.

[0009] In some embodiments, the substrate comprises a wafer or a sheet.

[0010] In some embodiments, the wafer comprises a silicon wafer.

[0011] In some embodiments, the sheet comprises one or more of a polyimide sheet or a polyethylene terephthalate sheet.

[0012] In some embodiments, the first cleaning substance comprises one or more of a soft elastomer filled, a soft elastomer unfilled, or a hard abrasive material.

[0013] In some of these embodiments, the soft elastomer filled of the first cleaning substance comprises one or more of a cleaning polymer or a polydimethylsiloxane composition, and further comprises abrasive particles. In some embodiments, the soft elastomer unfilled of the first cleaning substance comprises one or more of a cleaning polymer or a polydimethylsiloxane composition, and does not comprise abrasive particles. In some of these embodiments, the hard abrasive of the first cleaning substance comprises one or more of (i) a polymeric composition comprising an epoxy composition, an acryliccomposition, and / or a polyurethane composition and abrasive particles or (ii) a hard, non- polymeric material.

[0014] In some embodiments, the second cleaning substance comprises one or more of a soft elastomer filled, a soft elastomer unfilled, or a hard abrasive material.

[0015] In some of these embodiments, the soft elastomer polymer filled of the second cleaning substance comprises one or more of a cleaning polymer or a polydimethylsiloxane composition, and further comprises abrasive particles. In some of these embodiments, the soft elastomer unfilled of the second cleaning substance comprises one or more of a cleaning polymer or a polydimethylsiloxane composition, and does not comprise abrasive particles. In some of these embodiments, the hard abrasive of the second cleaning substance comprises one or more of (i) a polymeric composition comprising an epoxy composition, an acrylic composition, and / or a polyurethane composition and abrasive particles or (ii) a hard, non- polymeric material.

[0016] In some embodiments, the first cleaning substance comprises a soft elastomer filled or a soft elastomer unfilled and the second cleaning substance comprises a hard abrasive material.

[0017] In some embodiments, the first cleaning substance comprises a hard abrasive material and the second cleaning substance comprises a soft elastomer filled or a soft elastomer unfilled.

[0018] In some embodiments, the one or more first domains comprise only one first domain.

[0019] In some embodiments, the one or more first domains comprise a plurality of first domains.

[0020] In some embodiments, the one or more second domains comprise only one second domain.

[0021] In some embodiments, the one or more second domains comprise a plurality of second domains.

[0022] In some embodiments, the one or more second domains all extend from the upper surface of the cleaning material to the lower surface of the cleaning material.

[0023] In some embodiments, the one or more second domains all extend from the upper surface of the cleaning material to one or more underlying portions of the one or more first domains.

[0024] In some embodiments, the one or more first domains extend a distance of at least 100 microns from the upper surface of the cleaning material to the lower surface of thecleaning material, and the one or more second domains extend a distance of at least 100 microns from the upper surface of the cleaning material to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains.

[0025] In some embodiments, the at least one cleaning property by which the first cleaning substance differs from the second cleaning substance comprises one or more of (i) resin identity, (ii) abrasive identity, (iii) resin hardness, (iv) abrasive particle density, (v) abrasive particle size, and (vi) exposed surface roughness.

[0026] In some embodiments, the cleaning material is attached to the substrate indirectly via an adhesive.

[0027] In some embodiments, the cleaning material is attached to the substrate directly without an adhesive.

[0028] In some embodiments, the upper surface of the cleaning material has been planarized. In some of these embodiments, the first phase and the second phase each have a microscopic roughness at the upper surface of the cleaning material due to the cleaning material having been planarized.

[0029] In some embodiments, the upper surface of the cleaning material has not been planarized.

[0030] In some embodiments, the upper surface of the cleaning material has a flatness tolerance of less than 40 microns, 30 microns, 20 microns, or 10 microns across the upper surface.

[0031] In some embodiments, the upper surface of the cleaning material has a flatness tolerance of less than 10 microns across each intersection of the first domain and the second domain at the upper surface.

[0032] In some embodiments, the first domain and the second domain each have at least one lateral dimension of less than 500 microns between the other domain.

[0033] In some embodiments, the first domain and the second domain each have widths of 10 to 500 microns, with pitches from domain center to domain center of 15 to 1,000 microns, and / or the first domain and the second domain have lengths of 10 microns to 300 mm.

[0034] In some embodiments, the cleaning material further comprises one or more additional phases comprising one or more additional cleaning substances, wherein: the one or more additional phases are disposed within the cleaning material in one or more additional domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains;and the one or more additional cleaning substances differ from the first cleaning substance and the second cleaning substance with respect to at least one cleaning property.BRIEF DESCRIPTION OF THE DRAWINGS

[0035] These and other features, aspects, and advantages of the present disclosure are better understood when the following detailed description is read with reference to the accompanying drawings.

[0036] FIG. 1 is a top view of an embodiment of the cleaning device for cleaning probe tips as disclosed herein in which the substrate is a wafer, the cleaning device comprises only one first domain, the cleaning device comprises a plurality of second domains, and the second domains have a circular shape from a top view.

[0037] FIG. l is a bottom view of the cleaning device of FIG. 1.

[0038] FIG. 3 is a side view of the cleaning device of FIG. 1.

[0039] FIG. 4 is an exploded side view of the cleaning device of FIG. 1.

[0040] FIG. 5 is an expanded side view of a portion of the cleaning device of FIG. 3.

[0041] FIG. 6 is an expanded sectional view of a portion of the cleaning device of FIG. 1, in which the second domains all extend from the upper surface of the cleaning material to an underlying portion of the first domain.

[0042] FIG. 7 is an expanded sectional view of an alternative embodiment of the cleaning device of FIG. 6, in which the second domains all extend from the upper surface of the cleaning material to the lower surface of the cleaning material.

[0043] FIG. 8 is a top view of an embodiment of the cleaning device as disclosed herein in which the substrate is a wafer, the cleaning device comprises only one first domain, the cleaning device comprises a plurality of second domains, and the second domains have a square shape from a top view.

[0044] FIG. 9 is a top view of an embodiment of the cleaning device as disclosed herein in which the substrate is a wafer, the cleaning device comprises a plurality of first domains and a plurality of second domains, and the first domains and the second domains have a square shape from a top view.

[0045] FIG. 10 is a bottom view of the cleaning device of FIG. 9.

[0046] FIG. 11 is a side view of the cleaning device of FIG. 9.

[0047] FIG. 12 is an expanded side view of a portion of the cleaning device of FIG. 11.

[0048] FIG. 13 is an expanded sectional view of a portion of the cleaning device of FIG. 9, in which the second domains all extend from the upper surface of the cleaning material to the lower surface of the cleaning material.

[0049] FIG. 14 is a top view of an embodiment of the cleaning device as disclosed herein in which the substrate is a sheet, the cleaning device comprises one first domain, the cleaning device comprises a plurality of second domains, and the second domains have a circular shape from a top view.

[0050] FIG. 15 is a bottom view of the cleaning device of FIG. 14.

[0051] FIG. 16 is a side view of the cleaning device of FIG. 14.

[0052] FIG. 17 is an expanded side view of a portion of the cleaning device of FIG. 16.

[0053] FIG. 18 is an expanded sectional view of a portion of the cleaning device of FIG.14, in which the second domains all extend from the upper surface of the cleaning material to an underlying portion of the first domain.

[0054] FIG. 19 is an expanded sectional view of an alternative embodiment of the cleaning device of FIG. 18, in which the second domains all extend from the upper surface of the cleaning material to the lower surface of the cleaning material.

[0055] FIG. 20 is a top view of an embodiment of the cleaning device for cleaning probe tips as disclosed herein in which the substrate is a wafer, the cleaning device comprises only one first domain, the cleaning device comprises a plurality of second domains and a plurality of third domains, and the second domains and the third domains have a circular shape from a top view.

[0056] FIG. 21 illustrates a probe tip of a probe card relative to a cleaning material of a cleaning device as disclosed herein.

[0057] FIG. 22 shows a micrograph of a portion of the upper surface of the cleaning material of an embodiment of the cleaning device as disclosed herein and a heat map of a portion of the upper surface representing variations in surface height across the upper surface. The heat map indicates that surface height varies from -1.64 to 2.904 microns across the area of the upper surface shown.

[0058] FIG. 23 illustrates a probe tip “stepping” across the cleaning material of an embodiment of the cleaning device as disclosed herein by x-y indexing, a heat map representing variations in surface height across the upper surface, and a graph providing measurements of variations in surface height across the upper surface.

[0059] FIG. 24 is an image of an example prototype of the cleaning device as disclosed herein and a graph indicating topography of the cleaning material of the prototype.

[0060] FIG. 25 shows a probe force curve graph of a prototype of the cleaning device as disclosed herein designated “Abrasive design 1.”

[0061] FIG. 26 shows a probe force curve graph of a prototype of the cleaning device as disclosed herein designated “Abrasive design 2.”

[0062] FIG. 27 shows probe force curve graphs of a prototype of the cleaning device as disclosed herein including a hard abrasive, as follows: left graph: room temperature; central graph: 130 °C; right graph: 175 °C.

[0063] FIG. 28 shows results of effectiveness of cleaning of probe tips by a one-step cleaning process using a single cleaning device corresponding to a wafer including Gel-Pak’s GP -REFINE H composition versus a two-step cleaning process using a first cleaning device corresponding to a textured silicon wafer and a second cleaning device corresponding to the wafer including Gel-Pak’s GP -REFINE H composition.

[0064] FIG. 29 shows results of effectiveness of cleaning of probe tips by using our “2-in- 1” cleaning wafer device including a first domain including Gel-Pak’s GEL-PROBE REFINE composition attached to a silicon wafer, and a second domain including an epoxy resin filled with aluminum oxide abrasive particles bonded to the first domain.

[0065] FIG. 30 shows results of effectiveness of restoration of contact resistance to probe tips by a two-step cleaning process using a first cleaning device corresponding to a textured silicon wafer and a second cleaning device corresponding to the wafer including Gel-Pak’s GP -REFINE H composition, a one-step cleaning process using a single cleaning device corresponding to a wafer including Gel-Pak’s GP -REFINE H composition, and a cleaning process using our “2-in-l” cleaning wafer device.DETAILED DESCRIPTION OF THE INVENTION

[0066] We have developed a cleaning device for cleaning probe tips that can be used advantageously during online probe card cleaning for regular cleaning and proper maintenance of probe tips by effectively removing debris from probe tips while also maintaining flatness and roughness of the probe tip in a single cleaning cycle.

[0067] Our cleaning device includes a substrate and a cleaning material attached to the substrate and is configured such that within the cleaning material there are two or more phases of cleaning substances. Each phase comprises a cleaning substance that differs from the cleaning substance of the other phase or phases with respect to at least one cleaning property. The first phase, comprising a first cleaning substance, is disposed within the cleaning material in one or more first domains extending from the upper surface of thecleaning material to the lower surface of the cleaning material. The second phase, comprising a second cleaning substance, is disposed within the cleaning material in one or more second domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains. Any additional phases, comprising additional cleaning substances, likewise are disposed within the cleaning material in a plurality of additional domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains. The upper surface of the cleaning material has a flatness tolerance of less than 50 microns across the upper surface. This configuration results in the various domains being adjacent to each other in the x-y plane at the upper surface of the cleaning material, and the upper surface of the cleaning material being substantially flat.

[0068] Our cleaning device can be used to accomplish single cleaning cycles that include, for example, one or more touchdowns of probe tips in a z-direction in one or more first domains of our cleaning device including a first cleaning substance for removing debris from the probe tips, and one or more touchdowns of the probe tips also in a z-direction in one or more second domains of our device including a second cleaning substance for maintaining flatness and roughness of the probe tip, with x-y indexing of the probe tips between each touchdown. This advantageously eliminates the increases in cleaning time and complexity associated with two-step processes and allows for precise x-y indexing of probe tips across different cleaning zones in a single cycle.

[0069] Considering our cleaning device in detail, with reference to FIGS. 1-7, the cleaning device 100 comprises a substrate 102 having an upper surface 104 and a lower surface 106. The upper surface 104 and the lower surface 106 of the substrate 102 are major surfaces, such that the length and width of the substrate 102 along the upper surface 104 and the lower surface 106 are substantially greater than the height of the substrate 102 between the upper surface 104 and the lower surface 106. This provides ample surface area at the upper surface 104 of the substrate 102 to support a cleaning material 112, and ample surface area at the lower surface 106 for a chuck to support the substrate 102.

[0070] In some embodiments, the substrate 102 comprises a wafer 108, as shown in FIGS. 1-13 and FIG. 20, or a sheet 110, as shown in FIGS. 14-19. The use of a wafer 108 as the substrate 102 can be useful for ease of loading the cleaning device 100 into a wafer chuck for applications involving use a wafer 108 sized for the wafer chuck. The use of a sheet 110 as the substrate 102 can be useful for lamination of the cleaning device 100 onto a wafer proberauxiliary chuck swapped for a wafer chuck for applications in which a wafer sized for a wafer chuck is not available.

[0071] The wafer 108 can be, for example, a silicon wafer. Exemplary suitable silicon wafers include, for example, circular silicon wafers having diameters of 200 mm, 300 mm, 1 inch (25.4 mm), or 2 inches (50.8 mm). Silicon wafers of other shapes and sizes can be suitable too.

[0072] The sheet 110 can be, for example, one or more of a polyimide sheet or a polyethylene terephthalate sheet. The sheet 110 can have any suitable shape and size, such as, for example, a square shape with sides of 160 mm, among other shapes and sizes. The sheet 100 can be cut to size as needed, for example for lamination of the cleaning device 100 onto a wafer prober auxiliary chuck as noted above.

[0073] With reference to FIGS. 1-7, the cleaning device 100 also comprises a cleaning material 112 having an upper surface 114 and a lower surface 116. Like for the substrate 102, the upper surface 114 and the lower surface 116 of the cleaning material 112 are major surfaces. This provides ample surface area at the upper surface 114 of the cleaning material 112 for multiple touchdowns of the probe tips into the cleaning material 112 with x-y indexing of the probe tips between each touchdown, and ample surface area at the lower surface 116 for the substrate 102 to support the cleaning material 112.

[0074] The cleaning material 112 is attached to the substrate 102. With reference to FIGS. 3-7, in some embodiments, the cleaning material is attached to the substrate indirectly via an adhesive 118. The adhesive 118 can include one or more adhesive compounds. This allows for attachment of a cleaning material 112 that would not adhere to the substrate 102 on its own. Although not shown, in some embodiments the cleaning material 112 is attached to the substrate 102 directly without an adhesive. This can be accomplished, for example, for a cleaning material 112 that can adhere to the substrate 102 on its own. Other approaches for attaching the cleaning material 112 to the substrate 102, for example, via chemical or physical treatments to accomplish attachment, can also be suitable.

[0075] With reference to FIG. 1, FIG. 5, and FIG. 6, the cleaning material 112 comprises (i) a first phase 120 comprising a first cleaning substance and (ii) a second phase 122 comprising a second cleaning substance. The first phase 120 is disposed within the cleaning material 112 in one or more first domains 124 extending from the upper surface 114 of the cleaning material 112 to the lower surface 116 of the cleaning material 112. The second phase 122 is disposed within the cleaning material 112 in one or more second domains 126 extending from the upper surface 114 of the cleaning material 112 to the lower surface 116 ofthe cleaning material 112 and / or to one or more underlying portions 128 of the one or more first domains 120.

[0076] In some embodiments, the first cleaning substance comprises one or more of a soft elastomer filled, a soft elastomer unfilled, or a hard abrasive material. The soft elastomer filled of the first cleaning substance can comprise, for example, one or more of a cleaning polymer or a polydimethylsiloxane composition, and further comprises abrasive particles. The abrasive particles can be, for example, inorganic abrasive particles, such as inorganic abrasive particles comprising silicon carbide and / or aluminum oxide, and / or organic abrasive particles, among other abrasive particles. The soft elastomer unfilled of the first cleaning substance can comprise, for example, one or more of a cleaning polymer or a polydimethylsiloxane composition, and does not comprise abrasive particles. The hard abrasive of the first cleaning substance can comprise, for example, one or more of one or more of (i) a polymeric composition comprising an epoxy composition, an acrylic composition, and / or a polyurethane composition and abrasive particles or (ii) a hard, non- polymeric material. The epoxy composition, acrylic composition, and polyurethane composition can be used as binders for the abrasive particles. The abrasive particles can be, again for example, inorganic abrasive particles, such as inorganic abrasive particles comprising silicon carbide and / or aluminum oxide, and / or organic abrasive particles, among other abrasive particles. The hard, non-polymeric material can be, for example, glass, silicon, tungsten carbide, and / or sapphire, for example in a homogenous form, such as a wafer.

[0077] Similarly, in some embodiments, the second cleaning substance comprises one or more of a soft elastomer filled, a soft elastomer unfilled, or a hard abrasive material. The soft elastomer filled of the second cleaning substance also can comprise, for example, one or more of a cleaning polymer or a polydimethylsiloxane composition, and further comprises abrasive particles. The abrasive particles can be, again for example, inorganic abrasive particles, such as inorganic abrasive particles comprising silicon carbide and / or aluminum oxide, and / or organic abrasive particles, among other abrasive particles. The soft elastomer unfilled of the second cleaning substance also can comprise, for example, one or more of a cleaning polymer or a polydimethylsiloxane composition, and does not comprise abrasive particles. The hard abrasive of the second cleaning substance also can comprise, for example, one or more of one or more of (i) a polymeric composition comprising an epoxy composition, an acrylic composition, and / or a polyurethane composition and abrasive particles or (ii) a hard, non-polymeric material. Again, the epoxy composition, acrylic composition, and polyurethane composition can be used as binders for the abrasive particles, the abrasiveparticles can be, for example, inorganic abrasive particles, such as inorganic abrasive particles comprising silicon carbide and / or aluminum oxide, and / or organic abrasive particles, among other abrasive particles, and the hard, non-polymeric material can be, for example, glass, silicon, tungsten carbide, and / or sapphire, for example in a homogenous form, such as a wafer.

[0078] The first cleaning substance differs from the second cleaning substance with respect to at least one cleaning property. In some embodiments, the at least one cleaning property by which the first cleaning substance differs from the second cleaning substance comprises one or more of (i) resin identity, (ii) abrasive identity, (iii) resin hardness, (iv) abrasive particle density, (v) abrasive particle size, and (vi) exposed surface roughness.

[0079] The first cleaning substance can differ from the second cleaning substance in terms of resin identity based, for example, on differences in polymeric compositions of the first cleaning substance and the second cleaning substance or the presence of a polymeric composition in the first cleaning substance but not the second cleaning substance, or vice versa. For example, the first cleaning substance can comprise a cleaning polymer or a polydimethylsiloxane composition, and the second cleaning substance can comprise a polymeric composition comprising an epoxy composition, an acrylic composition, and / or a polyurethane composition, or vice versa. Also for example, the first cleaning substance can comprise a cleaning polymer or a polydimethylsiloxane composition and the second cleaning substance can comprise a hard, non-polymeric material and not any polymeric composition, or vice versa.

[0080] The first cleaning substance can differ from the second cleaning substance in terms of abrasive identity based, for example, on differences in chemical structure and / or physical form of abrasive particles and / or hard abrasives of the first cleaning substance and the second cleaning substance or the presence of abrasive particles or hard abrasive in the first cleaning substance but not the second cleaning substance, or vice versa. For example, the first cleaning substance can comprise inorganic abrasive particles comprising silicon carbide and / or aluminum oxide and the second cleaning substance can comprise glass, silicon, tungsten carbide, and / or sapphire in a homogenous wafer form, or vice versa. Also for example, the first cleaning substance can comprise inorganic abrasive particles comprising silicon carbide and / or aluminum oxide or glass, silicon, tungsten carbide, and / or sapphire in a homogenous wafer form and the second cleaning substance can comprise a soft elastomer unfilled and not any abrasive, or vice versa.

[0081] The first cleaning substance can differ from the second cleaning substance in terms of resin hardness based, for example, on differences in hardness of polymeric compositions of the first cleaning substance and the second cleaning substance. For example, polydimethylsiloxane compositions have a resin hardness of 40 Shore 00 to 80 Shore A, whereas epoxy compositions, acrylic compositions, and polyurethane compositions have a resin hardness of 40-95 shore D.

[0082] The first cleaning substance can differ from the second cleaning substance in terms of abrasive particle density based, for example, on differences in density of abrasive particles of the first cleaning substance and the second cleaning substance. For example, densities of abrasive particles of the first cleaning substance and the second cleaning substance may differ from each other within an overall range of 70-300% of the polymer weight.

[0083] The first cleaning substance can differ from the second cleaning substance in terms of abrasive particle size based, for example, on differences in size of abrasive particles of the first cleaning substance and the second cleaning substance. For example, sizes of abrasive particles of the first cleaning substance and the second cleaning substance may differ from each other within an overall range of 0.05 to 15 microns.

[0084] The first cleaning substance can differ from the second cleaning substance in terms of exposed surface roughness based, for example, on differences in roughness of the first cleaning substance and the second cleaning substance at their exposed upper surfaces in the cleaning material. For example, roughness of the first cleaning substance and the second cleaning substance at their exposed upper surfaces in the cleaning material may differ from each other within an overall range of 0.05 to 5 microns.

[0085] These cleaning properties are relevant to cleaning probe tips, for example with respect to removing debris from the probe tips and maintaining flatness and roughness of the probe tip.

[0086] The first cleaning substance can differ from the second cleaning substance with respect to other cleaning properties too that also are relevant to cleaning probe tips.

[0087] The upper surface 114 of the cleaning material 112 has a flatness tolerance of less than 50 microns across the upper surface 114. Flatness tolerance is a tolerance of form indicating how much a surface can vary from perfect flatness. A flatness tolerance of less than 50 microns across the upper surface 114 means that the upper surface 114 lies entirely within two planes parallel to the upper surface 114 separated by less than 50 microns, for example 0 to 49 microns, 0 to 48 microns, 0 to 47 microns, 0 to 46 microns, 0 to 45 microns, 0 to 44 microns, 0 to 43 microns, 0 to 42 microns, 0 to 41 microns, 0 to 40 microns, 0 to 39microns, 0 to 38 microns, 0 to 37 microns, 0 to 36 microns, 0 to 35 microns, 0 to 34 microns, 0 to 33 microns, 0 to 32 microns, 0 to 31 microns, 0 to 30 microns, 0 to 29 microns, 0 to 28 microns, 0 to 27 microns, 0 to 26 microns, 0 to 25 microns, 0 to 24 microns, 0 to 23 microns, 0 to 22 microns, 0 to 21 microns, 0 to 20 microns, 0 to 19 microns, 0 to 18 microns, 0 to 17 microns, 0 to 16 microns, 0 to 15 microns, 0 to 14 microns, 0 to 13 microns, 0 to 12 microns, 0 to 11 microns, 0 to 10 microns, 0 to 9 microns, 0 to 8 microns, 0 to 7 microns, 0 to 6 microns, or 0 to 5 microns, among other ranges.

[0088] A flatness tolerance of the upper surface 114 of the cleaning material 112 of less than 50 microns is advantageous for achieving, among other things, uniform probe contact, consistent cleaning performance, and optical compatibility. Such a flatness tolerance helps to ensure uniform probe tip overdrive travel and force upon contact with the first domain 124 and the second domain 126 of the cleaning material 112, thereby preventing probe tip damage. Such a flatness tolerance also can provide improved optical clarity, enhanced x-y indexing, and consistent touch-down response. An increasingly tight flatness tolerance of the upper surface 114 of the cleaning material 112, for example of less than 40 microns, less than 30 microns, less than 20 microns, or less than 10 microns, is increasingly advantageous for these purposes. An increasingly tight flatness tolerance across intersections of the first domain 124 and the second domain 126 at the upper surface 114 also is increasingly advantageous for these purposes.

[0089] Accordingly, in some embodiments, the upper surface 114 of the cleaning material 112 has a flatness tolerance of less than 40 microns, 30 microns, 20 microns, or 10 microns across the upper surface 114.

[0090] Also, in some embodiments, the upper surface 114 of the cleaning material 112 has a flatness tolerance of less than 10 microns across each intersection of the first domain 124 and the second domain 126 at the upper surface 114.

[0091] With reference to FIGS. 21-23, in some embodiments, the first cleaning substance comprises a soft elastomer filled or a soft elastomer unfilled and the second cleaning substance comprises a hard abrasive material. These embodiments can be useful for accomplishing single cleaning cycles that include one or more touchdowns of probe tips in a z-direction in the first domain 124 including the first cleaning substance for removing debris from the probe tips, and one or more touchdowns of the probe tips in a z-direction in the second domain 126 including the second cleaning substance for maintaining flatness and roughness of the probe tip, with x-y indexing of the probe tips between each touchdown. For example, as shown in FIG. 21, a probe tip 200 can be moved from a first position 202, inwhich the probe tip 200 is positioned for a first touchdown in a z-direction in a first domain 124 of a soft polymer abrasive, to a second position 204, in which the probe tip 200 is positioned for a second touchdown in a z-direction in a second domain 126 of an abrasive loaded shaping polymer, with x-y movement of the probe tip 200 from the first position 202 to the second position 204 occurring between the first and second touchdowns, and corresponding to a distance D of, for example, 200-300 microns.

[0092] Likewise, in some embodiments, the first cleaning substance comprises a hard abrasive material and the second cleaning substance comprises a soft elastomer filled or a soft elastomer unfilled. These embodiments can be useful for accomplishing single cleaning cycles that include one or more touchdowns of probe tips in the second domain 126 including the second cleaning substance for removing debris from the probe tips, and one or more touchdowns of the probe tips in the first domain 124 including the first cleaning substance for maintaining flatness and roughness of the probe tip, with x-y indexing of the probe tips between each touchdown.

[0093] In some embodiments, other combinations of these and other cleaning substances also can be used to accomplish other single cleaning cycles as may suitable for any particular probe tips.

[0094] As shown in FIGS. 1-20, in some embodiments the locations, shapes, and sizes of the one or more first domains 124 and the one or more second domains 126 can be predefined. This can be helpful for carrying out a single cleaning cycle including multiple touchdowns of probe tips in the one or more first domains 124 and the one or more second domains 126 with x-y indexing of probe tips to predetermined distances between each touchdown. The locations, shapes, and sizes of the one or more first domains 124 and the one or more of second domains 126 do not need to be predetermined though. For example, distributing a plurality of second domains 126 randomly across a first domain 124 and then carrying out a single cleaning cycle including multiple touchdowns of probe tips in the first domain 124 and the second domains 126, again with x-y indexing of probe tips to predetermined distances between each touchdown, can result in sufficient cleaning and flattening of probe tips based on each probe tip touching down in the first domain 124 and the second domains 126 as determined by the ratio of surface area of the first domain 124 to surface area of the second domains 126 randomly according to a normal distribution.

[0095] With reference to FIGS. 1-8 and FIGS. 14-20, in some embodiments, the one or more first domains 124 comprise only one first domain 124. In accordance with these embodiments, the one or more second domains 126 may be distributed within, andsurrounded laterally by, the one first domain 124. Similarly, in some embodiments the one or more second domains 126 comprise only one second domain 126. In accordance with these embodiments, the one or more first domains 124 may be distributed within, and surrounded laterally by, the one second domain 126.

[0096] With reference to FIGS. 9-13, in some embodiments, the one or more first domains 124 comprise a plurality of first domains 124. In accordance with these embodiments, two or more first domains 124 of the plurality of first domains 124 may be separated laterally from each other by one or more of the second domains 126. Similarly, in some embodiments the one or more second domains 126 comprise a plurality of second domains 126. In accordance with these embodiments, two or more second domains 126 of the plurality of second domains 126 may be separated laterally from each other by one or more of the first domains 124.

[0097] As shown in FIG. 7, FIG. 12, and FIG. 19, in some embodiments, the one or more second domains 126 all extend from the upper surface 114 of the cleaning material 112 to the lower surface 116 of the cleaning material 112. In accordance with these embodiments, none of the one or more first domains 124 underlie any of the second domains 126.

[0098] Conversely, as shown in FIG. 6 and FIG. 18, in some embodiments, the one or more second domains 126 all extend from the upper surface 114 of the cleaning material 112 to one or more underlying portions 128 of the one or more first domains 124. In accordance with these embodiments, none of the second domains 126 extend to the lower surface 116 of the cleaning material 112.

[0099] In some embodiments, the one or more first domains 124 extend a distance of at least 100 microns from the upper surface 114 of the cleaning material 112 to the lower surface 116 of the cleaning material 112, and the one or more second domains 126 extend a distance of at least 100 microns from the upper surface 114 of the cleaning material 112 to the lower surface 116 of the cleaning material 112 and / or to one or more underlying portions 128 of the one or more first domains 124. For example, the one or more first domains 124 can extend a distance of 100 to 500 microns, 100 to 400 microns, 100 to 300 microns, 100 to 200 microns, or 100 to 150 microns from the upper surface 114 of the cleaning material 112 to the lower surface 116 of the cleaning material 112. Likewise for example, the one or more second domains 126 can extend a distance of 100 to 500 microns, 100 to 400 microns, 100 to 300 microns, 100 to 200 microns, or 100 to 150 microns from the upper surface 114 of the cleaning material 112 to the lower surface 116 of the cleaning material 112 and / or to one or more underlying portions 128 of the one or more first domains 124. These distances can be advantageous for providing sufficient depths of the one or more first domains 124 and theone or more second domains 126 to ensure that probe tips can be sufficiently cleaned of debris and / or flattened without the first domain 124 or the second domain 126 being too compliant and without the probe tips passing completely through the first domain 124 or the second domain 126 and contacting the substrate 102 or other underlying material.

[0100] In some embodiments, the upper surface 114 of the cleaning material 112 has been planarized. The upper surface 114 of the cleaning material 112 can be planarized to make the thickness of the cleaning material 112 substantially uniform and the upper surface 114 of the cleaning material 112 substantially flat. Thus, planarization can be used to achieve the flatness tolerance of less than 50 microns. For example, this can be used to achieve a flatness tolerance of less than 40 microns, less than 30 microns, less than 20 microns, or less than 10 microns, among other flatness tolerances. The upper surface 114 of the cleaning material 112 also can be planarized to impart a desired surface roughness and thus degree of abrasiveness. Accordingly, in some embodiments, the first phase and the second phase each have a microscopic roughness at the upper surface of the cleaning material due to the cleaning material having been planarized. The upper surface 114 of the cleaning material 112 also can be planarized to decrease reflectiveness. Planarization can be advantageous for achieving uniform probe contact, consistent cleaning performance, and optical compatibility, based on achieving the flatness tolerance of less than 50 microns, as discussed above. Planarization also can be helpful to ensure uniform probe tip overdrive travel and force upon contact with the first domain 124 and the second domain 126 of the cleaning material 112, thereby preventing probe tip damage, and can provide improved optical clarity, enhanced x-y indexing, and consistent touch-down response, also as discussed above. Planarization can be accomplished, for example, by abrasive polishing and solvent cleaning, for example by applying an abrasive across the upper surface 114 of the cleaning material 112, and removing resulting debris with a solvent such as isopropyl alcohol. Planarization also can be accomplished, for example, by mechanical milling, or other suitable approaches.

[0101] In some embodiments, the upper surface 114 of the cleaning material 112 has not been planarized. Planarization would not be needed, for example, if the thickness of the cleaning material 112 is substantially uniform and the upper surface 114 of the cleaning material 112 is substantially flat, and reflectiveness of the upper surface 114 is sufficiently low, without need for planarization, based on how the cleaning material 112 is made.

[0102] With reference to FIG. 20, in some embodiments the cleaning material 112 further comprises one or more additional phases 130 comprising one or more additional cleaning substances, wherein: the one or more additional phases 130 are disposed within the cleaningmaterial 112 in one or more additional domains 132 extending from the upper surface 114 of the cleaning material 112 to the lower surface 116 of the cleaning material 112 and / or to one or more underlying portions 128 of the one or more first domains 124; and the one or more additional cleaning substances differ from the first cleaning substance and the second cleaning substance with respect to at least one cleaning property. Including additional phases 130 can provide increased precision and flexibility in designing new single cleaning cycles suitable for cleaning probe tips and maintaining flatness and roughness of the probe tips while minimizing wear of the probe tips.

[0103] With reference to FIGS. 21-23, as discussed above our cleaning device can be used to accomplish single cleaning cycles that include, for example, one or more touchdowns of probe tips in a z-direction in a first domain of our cleaning device including a first cleaning substance for removing debris from the probe tips, and one or more touchdowns of the probe tips also in a z-direction in a second domain of our device including a second cleaning substance for maintaining flatness and roughness of the probe tip, with x-y indexing of the probe tips between each touchdown. The movement of the probe tips in the z-direction is carried out such that there is an “overdrive,” which is predefined in a cleaning cycle recipe. During each cleaning cycle, multiple touchdowns can be used. Thus, the cleaning material comes in contact with the probe tips multiple times. Cleaning cycle recipes are carried out with x-y indexing of the probe tips to the cleaning material to ensure that probe tips do not contact the cleaning material at a location previously contacted by a probe tip. Rather, the probe tips make contact with different areas of the cleaning material with each touchdown. Accordingly, as a probe tip “steps” across the cleaning material, the probe tip is able to contact multiple areas of the one or more first domains and multiple areas of the one or more second domains.

[0104] Importantly, during each touchdown each probe tip is contacting only the first cleaning substance or the second cleaning substance, not both. This is in contrast to, for example, devices in which a first cleaning substance would be provided on top of a second cleaning substance. In that case, a probe tip would need to penetrate the first cleaning substance in order to be exposed to the second cleaning substance. Such penetration could be challenging to control and could require excessive overdrive and force which might damage the probe tips. With the second cleaning substance disposed adjacent to the first cleaning substance in our cleaning device, the first cleaning substance and the second cleaning substance are readily exposed to the probe tip independently of each other.

[0105] Also importantly, the upper surface of the cleaning material is substantially flat, based on the upper surface having a flatness tolerance of less than 50 microns. This is in contrast to devices in which a tacky gel material is laminated on top of an abrasive substrate and raised above the surface of the abrasive substrate. As noted above, a flatness tolerance of less than 50 microns is advantageous for achieving uniform probe contact, consistent cleaning performance, and optical compatibility, helps to ensure uniform probe tip overdrive travel and force upon contact with the first domain and the second domain of the cleaning material, thereby preventing probe tip damage, and can provide improved optical clarity, enhanced x-y indexing, and consistent touch-down response.

[0106] Since the cleaning material has one or more second domains adjacent the one or more first domains, and the upper surface of the cleaning material is substantially flat, the probe tips can be cleaned and / or flattened multiple times by the corresponding first cleaning substance and second cleaning substance in a single cleaning cycle.

[0107] We have determined that use of our cleaning device including a first phase including a soft elastomer filled and a second phase including a hard abrasive in a single cleaning cycle provides improved contact resistance in probe tips in comparison to use of a soft elastomer filled alone. We also have determined that use of our cleaning device including a first phase including a soft elastomer filled and a second phase including a hard abrasive in a single cleaning cycle provides contact resistance to probe tips on par with using a two-step cleaning process.

[0108] Our cleaning device can be made using one or more approaches known in the semiconductor field including, for example, adhesion of cleaning substances to surfaces of substrates, 3D printing, casting, photolithography, etching, cutting, waterjet drilling, laser drilling, laser direct imaging, and / or screen printing.

[0109] For example, to prepare the prototype as tested in FIG. 22, we used a silicon wafer as a substrate and Gel-Pak’s GEL-PROBE REFINE composition, which is a film of a soft silicone polymer with silicon carbide abrasive particles embedded therein, and thus an example of a soft elastomer filled, having an approximate thickness of 200 microns, as a first domain attached to the substrate. Alternatively, a soft elastomer unfilled, such as Gel-Pak’s GEL-PROBE REMOVE composition, could be used. High hardness resins, such as epoxies, acrylics, or polyurethanes also could be used, as could high hardness wafers or substrates such as glass, silicon, or sapphire.

[0110] We attached the first domain to the substrate using an adhesive.

[0111] We formed cavities having diameters of 200 micron into the first domain. The pitch of each domain was 240 microns center to center.

[0112] We used an epoxy resin filled with aluminum oxide abrasive particles as a plurality of second domains, by filling this into the cavities formed in the first domain. Alternatively, soft polymer cleaning materials, such as Gel-Pak’s GEL-PROBE REMOVE composition, could be used, among other cleaning substances. The depth of the cavities and thus the second domain is at least 100 microns so that the underlying material does not impact the cleaning. If the hard cleaning material of the second domains was not sufficiently thick then the probe tip may not be polished correctly because the soft polymer under the hard cleaning material would be too compliant. Alternatively, if the soft polymer is used as the second domain and it is not sufficiently thick, then the probe tip may puncture the soft polymer and push into the hard underlying cleaning material. Other cleaning substances that could be used for the second domains in this context include polydimethylsiloxane, epoxies, polyurethanes, and acrylic crosslinking polymers and that can flow and take the shape of the cavities. The liquid polymers may have fillers such as abrasive particles that improve the cleaning ability of the liquid polymers. The liquid polymers would then be cured to crosslink and harden.

[0113] We then used a mechanical polishing step to level the upper surface of the cleaning material.

[0114] Preferably the first domain and the second domain of the cleaning material each have at least one lateral dimension of less than 500 microns between the other domain. This is to allow each probe tip to move from one domain to another within reasonable step sizes allowable by the prober. For example, the first domain and the second domain can each have widths of 10 to 500 microns, with pitches from domain center to domain center of 15 to 1,000 microns. The first domain and the second domain also may have lengths of 10 microns to 300 mm. The first domain and the second domain can have a variety of shapes from a top view, such as circles, concentric circles, squares, rectangles, and / or tortuous paths. Using the techniques and compositions described above, we have been able to make cavities that are sufficiently small, deep, and consistent and to fill the cavities and create level surfaces.

[0115] Accordingly, in some embodiments, the first domain and the second domain each have at least one lateral dimension of less than 500 microns between the other domain.

[0116] In some embodiments, the first domain and the second domain each have widths of 10 to 500 microns, with pitches from domain center to domain center of 15 to 1,000 microns; and / or the first domain and the second domain have lengths of 10 microns to 300 mm.EXAMPLES

[0117] EXAMPLE 1 : We have created an example “2-in-l” cleaning wafer device capable of cleaning and shaping probe tips of probe cards and have tested the cleaning wafer to determine various intrinsic properties.

[0118] Our aim was to make a cleaning material combining the cleaning properties of Gel- Pak’s soft GP -REFINE -H composition, which is a soft silicone polymer with silicon carbide abrasive particles embedded therein, and the probe tip flattening properties of a hard shaping abrasive. With each cleaning cycle, the probe tip can touch down and step across the soft polymer or the hard shaping abrasive.

[0119] In an initial analysis, a probe card contact resistance was determined to be stable when touching down onto Gel-Pak’s GP-REFINE-H composition as a cleaning material. However, to effectively shape the tip and remove excess aluminum shavings, it is recommended to use a cleaning cycle involving a two-step process, the first step being for probe tips to touch down on a textured silicon wafer and the second step being for the probe tips to touch down on the GP -REFINE H composition. To reproduce the shaping properties of a shaping wafer, we decided to use a hard resin that is highly loaded with aluminum oxide abrasive particles. Two different high temperature resins were used.

[0120] To be effective, the abrasive binding resin must have temperature stability. In this example, the temperature stability was demonstrated with hardness measurements performed at elevated temperatures of 125 °C and 175 °C. A radius tip tungsten needle with a 7 micron tip diameter was inserted into the materials at random locations while measuring force and overdrive.

[0121] In addition, uniform topography, distinct hard abrasive areas, and distinct soft tacky areas are required to effectively shape and clean probe tips. We employed multiple methods with the consideration that the topography would need to be customized depending on the cleaning recipe and probe card design.

[0122] We were able to design and produce a cleaning device including a cleaning material with distinct areas of cleaning using a customizable manufacturing process. As shown in FIG. 24, the distinct cleaning areas are nearly indistinguishable to the naked eye and under a microscope. Also as shown, the material roughness and thickness variation are nearly the same as a typical Gel-Pak GEL-PROBE cleaning wafer

[0123] Using the customizable manufacturing process, we were able to adjust the amount of abrasion experienced by a probe tip. FIG. 25 and FIG. 26 show force vs displacement graphs for probe insertions. The probe tips touch down on the cleaning material at random locationsand the amount of force vs overdrive is recorded. FIG. 25 shows a cleaning device including a cleaning material with 75% polymer abrasive. FIG. 26 shows a cleaning device including a cleaning material with 23% polymer abrasive. The results indicate that the abrasive material is distinctly and consistently harder than the Gel-Pak’s soft GP -REFINE H polymer abrasive composition.

[0124] A critical requirement is that the cleaning material is stable across relevant operating temperatures. Force vs overdrive was recorded for the materials across relevant operating temperatures from room temperature to 175 °C. As shown in FIG. 27, minimal differences were seen among the temperatures tested.

[0125] Our results show that the cleaning material of our cleaning device has distinct cleaning properties provided by distinct soft polymer abrasive areas and hard probe pin shaping areas of the cleaning material. The areas are customizable in shape and density and the material is serviceable to high temperatures tested up to 175 °C.

[0126] EXAMPLE 2: Testing indicates that our “2-in-l” cleaning wafer device can be used to remove aluminum debris from probe tips without need for a hard silicon wafer and can provide contact resistance on par with using a two-step cleaning process, without the increased cleaning time and complexity required of a two-step cleaning process.

[0127] In this experiment, wafers coated in aluminum are used to simulate probe pads in terms of introducing aluminum contamination onto probe pins. For context, in practice probe pads are coated with aluminum, and probe pins become contaminated with aluminum based on repeated contact with the probe pads. In this experiment, probe pins touching down on the aluminum coated wafers likewise results in contamination of the probe pins with aluminum.

[0128] First, a comparison was conducted of effectiveness of cleaning of probe tips by a one-step cleaning process using single cleaning device corresponding to a wafer including Gel-Pak’s GP -REFINE H composition versus a two-step cleaning process using a first cleaning device corresponding to a textured silicon wafer and a second cleaning device corresponding to the wafer including Gel-Pak’s GP -REFINE H composition.

[0129] Experimental conditions were as follows. Wafer temperature was maintained at 125 °C. Thickness of the aluminum coating on the wafers coated in aluminum was 8000 Angstroms (800 nm). The probe pins were contacted with aluminum by conducting 25 touchdowns of the probe pins on the aluminum coating on the wafers with an overdrive of 100 microns. The probe pins were then subjected to a first cleaning condition or a second cleaning condition.

[0130] The first cleaning condition involved conducting 20 touchdowns of the probe pins on the wafer including Gel-Pak’s GP -REFINE H composition with an overdrive of 100 microns.

[0131] The second cleaning condition involved conducting five touchdowns of the probe pins on the textured silicon wafer and five touchdowns of the probe pins on the wafer including Gel-Pak’s GP -REFINE H composition, all with an overdrive of 100 microns.

[0132] Results are shown in FIG. 28. The results indicate that contacting the probe pins with the aluminum coating of the wafers covered in aluminum resulted in contamination of the probe pins with aluminum, as expected. The results also indicate that the second cleaning condition was able to sufficiently remove aluminum contamination from the probe tips, whereas the first cleaning conditions was not. As noted above, Gel-Pak’s soft GP -REFINE -H composition is a soft silicone polymer with silicon carbide abrasive particles embedded therein. It is able to gently abrade contaminated probe tips. However, because it is soft, it is unable to sufficiently remove debris from flat tipped vertical probe tips when used on a wafer alone in a one-step process. In contrast, using a textured silicon wafer as first cleaning device and a wafer including Gel-Pak’s soft GP-REFINE-H composition as a second cleaning device during a two-step process accomplished sufficient removal of debris.

[0133] Effectiveness of cleaning of probe tips by using our “2-in-l” cleaning wafer device also was tested. Our “2-in-l” cleaning wafer device includes a first domain including Gel- Pak’s GEL-PROBE REFINE composition attached to a silicon wafer, and a second domain including an epoxy resin filled with aluminum oxide abrasive particles bonded to the first domain.

[0134] Experimental conditions were as described above. Again, the probe pins were contacted with aluminum by conducting 25 touchdowns of the probe pins on the aluminum coating on the wafers with an overdrive of 100 microns. The probe pins were then subjected to a third cleaning condition or a fourth cleaning condition.

[0135] The third cleaning condition involved conducting ten touchdowns of the probe pins on our “2-in-l” cleaning wafer device, with approximately equal numbers of touchdowns in the first domain including GEL-PROBE REFINE composition and the second domain including epoxy resin filled with aluminum oxide abrasive particles, with an overdrive of 100 microns. The fourth cleaning condition involved conducting twenty touchdowns of the probe pins on our “2-in-l” cleaning wafer device, again with approximately equal numbers of touchdowns in the first domain and the second domain.

[0136] Results are shown in FIG. 29. The results indicate that the fourth cleaning condition was able to sufficiently remove aluminum contamination from the probe tips, whereas the third cleaning conditions was not. Using our “2-in-l” cleaning wafer device including the first domain including Gel-Pak’s GEL-PROBE REFINE composition and the second domain including epoxy resin filled with aluminum oxide abrasive particles during a cleaning cycle including 20 touchdowns, with approximately equal numbers of touchdowns in the first domain and the second domain, accomplished sufficient removal of debris, comparable that achieved using a two-step process involving a first cleaning device including a textured silicon wafer and a second cleaning device including Gel-Pak’s soft GP -REFINE -H composition, with five touchdowns on each. Importantly, although use of our “2-in-l” cleaning wafer device required more total touchdowns than use of two cleaning devices in the two-step process in this experiment, use of our “2-in-l” cleaning wafer device this way advantageously accomplished sufficient removal of the aluminum without the increased cleaning time and complexity required of a two-step cleaning process.

[0137] Effectiveness of restoration of contact resistance to probe tips was also tested. Results are shown in FIG. 30. The results indicate that our “2-in-l” cleaning wafer device achieves better contact resistance than a cleaning wafer including only the GEL-PROBE REFINE composition. The results also indicate that our “2-in-l” cleaning wafer device advantageously achieves contact resistance on par with using a two-step cleaning process, again without the increased cleaning time and complexity required of a two-step cleaning process.

[0138] While this invention has been described in conjunction with the specific embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention.

[0139] CLAUSES

[0140] Clause 1 : A cleaning device for cleaning probe tips comprising: (a) a substrate having an upper surface and a lower surface; and (b) a cleaning material having an upper surface and a lower surface; wherein: the cleaning material is attached to the substrate; the cleaning material comprises (i) a first phase comprising a first cleaning substance and (ii) a second phase comprising a second cleaning substance; the first phase is disposed within the cleaning material in one or more first domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material; the second phase is disposedwithin the cleaning material in one or more second domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains; the first cleaning substance differs from the second cleaning substance with respect to at least one cleaning property; and the upper surface of the cleaning material has a flatness tolerance of less than 50 microns across the upper surface.

[0141] Clause 2: The cleaning device of clause 1, wherein the substrate comprises a wafer or a sheet.

[0142] Clause 3: The cleaning device of clause 2, wherein the wafer comprises a silicon wafer.

[0143] Clause 4: The cleaning device of clause 2, wherein the sheet comprises one or more of a polyimide sheet or a polyethylene terephthalate sheet.

[0144] Clause 5: The cleaning device of any one of clauses 1 to 4, wherein the first cleaning substance comprises one or more of a soft elastomer filled, a soft elastomer unfilled, or a hard abrasive material.

[0145] Clause 6: The cleaning device of clause 5, wherein the soft elastomer filled of the first cleaning substance comprises one or more of a cleaning polymer or a polydimethylsiloxane composition, and further comprises abrasive particles.

[0146] Clause 7: The cleaning device of clause 5 or clause 6, wherein the soft elastomer unfilled of the first cleaning substance comprises one or more of a cleaning polymer or a polydimethylsiloxane composition, and does not comprise abrasive particles.

[0147] Clause 8: The cleaning device of any one of clauses 5 to 7, wherein the hard abrasive of the first cleaning substance comprises one or more of (i) a polymeric composition comprising an epoxy composition, an acrylic composition, and / or a polyurethane composition and abrasive particles or (ii) a hard, non-polymeric material.

[0148] Clause 9: The cleaning device of any one of clauses 1 to 8, wherein the second cleaning substance comprises one or more of a soft elastomer filled, a soft elastomer unfilled, or a hard abrasive material.

[0149] Clause 10: The cleaning device of clause 9, wherein the soft elastomer filled of the second cleaning substance comprises one or more of a cleaning polymer or a polydimethylsiloxane composition, and further comprises abrasive particles.

[0150] Clause 11 : The cleaning device of clause 9 or clause 10, wherein the soft elastomer unfilled of the second cleaning substance comprises one or more of a cleaning polymer or a polydimethylsiloxane composition, and does not comprise abrasive particles.

[0151] Clause 12: The cleaning device of any one of clauses 9 to 11, wherein the hard abrasive of the second cleaning substance comprises one or more of (i) a polymeric composition comprising an epoxy composition, an acrylic composition, and / or a polyurethane composition and abrasive particles or (ii) a hard, non-polymeric material.

[0152] Clause 13: The cleaning device of any one of clauses 1 to 12, wherein the first cleaning substance comprises a soft elastomer filled or a soft elastomer unfilled and the second cleaning substance comprises a hard abrasive material.

[0153] Clause 14: The cleaning device of any one of clauses 1 to 12, wherein the first cleaning substance comprises a hard abrasive material and the second cleaning substance comprises a soft elastomer filled or a soft elastomer unfilled.

[0154] Clause 15: The cleaning device of any one of clauses 1 to 14, wherein the one or more first domains comprise only one first domain.

[0155] Clause 16: The cleaning device of any one of clauses 1 to 14, wherein the one or more first domains comprise a plurality of first domains.

[0156] Clause 17: The cleaning device of any one of clauses 1 to 16, wherein the one or more second domains comprise only one second domain.

[0157] Clause 18: The cleaning device of any one of clauses 1 to 16, wherein the one or more second domains comprise a plurality of second domains.

[0158] Clause 19: The cleaning device of any one of clauses 1 to 18, wherein the one or more second domains all extend from the upper surface of the cleaning material to the lower surface of the cleaning material.

[0159] Clause 20: The cleaning device of any one of clauses 1 to 18, wherein the one or more second domains all extend from the upper surface of the cleaning material to one or more underlying portions of the one or more first domains.

[0160] Clause 21 : The cleaning device of any one of clauses 1 to 20, wherein the one or more first domains extend a distance of at least 100 microns from the upper surface of the cleaning material to the lower surface of the cleaning material, and the one or more second domains extend a distance of at least 100 microns from the upper surface of the cleaning material to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains.

[0161] Clause 22: The cleaning device of any one of clauses 1 to 21, wherein the at least one cleaning property by which the first cleaning substance differs from the second cleaning substance comprises one or more of (i) resin identity, (ii) abrasive identity, (iii) resinhardness, (iv) abrasive particle density, (v) abrasive particle size, and (vi) exposed surface roughness.

[0162] Clause 23 : The cleaning device of any one of clauses 1 to 22, wherein the cleaning material is attached to the substrate indirectly via an adhesive.

[0163] Clause 24: The cleaning device of any one of clauses 1 to 22, wherein the cleaning material is attached to the substrate directly without an adhesive.

[0164] Clause 25: The cleaning device of any one of clauses 1 to 24, wherein the upper surface of the cleaning material has been planarized.

[0165] Clause 26: The cleaning device of clause 25, wherein the first phase and the second phase each have a microscopic roughness at the upper surface of the cleaning material due to the cleaning material having been planarized.

[0166] Clause 27: The cleaning device of any one of clauses 1 to 24, wherein the upper surface of the cleaning material has not been planarized.

[0167] Clause 28: The cleaning device of any one of clauses 1 to 27, wherein the upper surface of the cleaning material has a flatness tolerance of less than 40 microns, 30 microns, 20 microns, or 10 microns across the upper surface.

[0168] Clause 29: The cleaning device of any one of clauses 1 to 27, wherein the upper surface of the cleaning material has a flatness tolerance of less than 10 microns across each intersection of the first domain and the second domain at the upper surface.

[0169] Clause 30: The cleaning device of any one of clauses 1 to 29, wherein the first domain and the second domain each have at least one lateral dimension of less than 500 microns between the other domain.

[0170] Clause 31 : The cleaning device of any one of clauses 1 to 30, wherein: the first domain and the second domain each have widths of 10 to 500 microns, with pitches from domain center to domain center of 15 to 1,000 microns; and / or the first domain and the second domain have lengths of 10 microns to 300 mm.

[0171] Clause 32: The cleaning device of any one of clauses 1 to 31, wherein the cleaning material further comprises one or more additional phases comprising one or more additional cleaning substances, wherein: the one or more additional phases are disposed within the cleaning material in one or more additional domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains; and the one or more additional cleaning substances differ from the first cleaning substance and the second cleaning substance with respect to at least one cleaning property.

Claims

CLAIMS1. A cleaning device for cleaning probe tips comprising:(a) a substrate having an upper surface and a lower surface; and(b) a cleaning material having an upper surface and a lower surface; wherein: the cleaning material is attached to the substrate; the cleaning material comprises (i) a first phase comprising a first cleaning substance and (ii) a second phase comprising a second cleaning substance; the first phase is disposed within the cleaning material in one or more first domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material; the second phase is disposed within the cleaning material in one or more second domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains; the first cleaning substance differs from the second cleaning substance with respect to at least one cleaning property; and the upper surface of the cleaning material has a flatness tolerance of less than 50 microns across the upper surface.

2. The cleaning device of claim 1, wherein the substrate comprises a wafer or a sheet.

3. The cleaning device of claim 2, wherein the wafer comprises a silicon wafer.

4. The cleaning device of claim 2, wherein the sheet comprises one or more of a polyimide sheet or a polyethylene terephthalate sheet.

5. The cleaning device of claim 1, wherein the first cleaning substance comprises one or more of a soft elastomer filled, a soft elastomer unfilled, or a hard abrasive material.

6. The cleaning device of claim 5, wherein the soft elastomer filled of the first cleaning substance comprises one or more of a cleaning polymer or a polydimethylsiloxane composition, and further comprises abrasive particles.

7. The cleaning device of claim 5, wherein the soft elastomer unfilled of the first cleaning substance comprises one or more of a cleaning polymer or a polydimethylsiloxane composition, and does not comprise abrasive particles.

8. The cleaning device of claim 5, wherein the hard abrasive of the first cleaning substance comprises one or more of (i) a polymeric composition comprising an epoxy composition, an acrylic composition, and / or a polyurethane composition and abrasive particles or (ii) a hard, non-polymeric material.

9. The cleaning device of claim 1, wherein the second cleaning substance comprises one or more of a soft elastomer filled, a soft elastomer unfilled, or a hard abrasive material.

10. The cleaning device of claim 9, wherein the soft elastomer filled of the second cleaning substance comprises one or more of a cleaning polymer or a polydimethylsiloxane composition, and further comprises abrasive particles.

11. The cleaning device of claim 9, wherein the soft elastomer unfilled of the second cleaning substance comprises one or more of a cleaning polymer or a polydimethylsiloxane composition, and does not comprise abrasive particles.

12. The cleaning device of claim 9, wherein the hard abrasive of the second cleaning substance comprises one or more of (i) a polymeric composition comprising an epoxy composition, an acrylic composition, and / or a polyurethane composition and abrasive particles or (ii) a hard, non-polymeric material.

13. The cleaning device of claim 1, wherein the first cleaning substance comprises a soft elastomer filled or a soft elastomer unfilled and the second cleaning substance comprises a hard abrasive material.

14. The cleaning device of claim 1, wherein the first cleaning substance comprises a hard abrasive material and the second cleaning substance comprises a soft elastomer filled or a soft elastomer unfilled.

15. The cleaning device of claim 1, wherein the one or more first domains comprise only one first domain.

16. The cleaning device of claim 1, wherein the one or more first domains comprise a plurality of first domains.

17. The cleaning device of claim 1, wherein the one or more second domains comprise only one second domain.

18. The cleaning device of claim 1, wherein the one or more second domains comprise a plurality of second domains.

19. The cleaning device of claim 1, wherein the one or more second domains all extend from the upper surface of the cleaning material to the lower surface of the cleaning material.

20. The cleaning device of claim 1, wherein the one or more second domains all extend from the upper surface of the cleaning material to one or more underlying portions of the one or more first domains.

21. The cleaning device of claim 1, wherein the one or more first domains extend a distance of at least 100 microns from the upper surface of the cleaning material to the lower surface of the cleaning material, and the one or more second domains extend a distance of at least 100 microns from the upper surface of the cleaning material to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains.

22. The cleaning device of claim 1, wherein the at least one cleaning property by which the first cleaning substance differs from the second cleaning substance comprises one or more of (i) resin identity, (ii) abrasive identity, (iii) resin hardness, (iv) abrasive particle density, (v) abrasive particle size, and (vi) exposed surface roughness.

23. The cleaning device of claim 1, wherein the cleaning material is attached to the substrate indirectly via an adhesive.

24. The cleaning device of claim 1, wherein the cleaning material is attached to the substrate directly without an adhesive.

25. The cleaning device of claim 1, wherein the upper surface of the cleaning material has been planarized.

26. The cleaning device of claim 25, wherein the first phase and the second phase each have a microscopic roughness at the upper surface of the cleaning material due to the cleaning material having been planarized.

27. The cleaning device of claim 1, wherein the upper surface of the cleaning material has not been planarized.

28. The cleaning device of claim 1, wherein the upper surface of the cleaning material has a flatness tolerance of less than 40 microns, 30 microns, 20 microns, or 10 microns across the upper surface.

29. The cleaning device of claim 1, wherein the upper surface of the cleaning material has a flatness tolerance of less than 10 microns across each intersection of the first domain and the second domain at the upper surface.

30. The cleaning device of claim 1, wherein the first domain and the second domain each have at least one lateral dimension of less than 500 microns between the other domain.

31. The cleaning device of claim 1, wherein: the first domain and the second domain each have widths of 10 to 500 microns, with pitches from domain center to domain center of 15 to 1,000 microns; and / or the first domain and the second domain have lengths of 10 microns to 300 mm.

32. The cleaning device of claim 1, wherein the cleaning material further comprises one or more additional phases comprising one or more additional cleaning substances, wherein: the one or more additional phases are disposed within the cleaning material in one or more additional domains extending from the upper surface of the cleaning material to the lower surface of the cleaning material and / or to one or more underlying portions of the one or more first domains; andthe one or more additional cleaning substances differ from the first cleaning substance and the second cleaning substance with respect to at least one cleaning property.

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