# US 2019/0170815 A1 · Elemental mercury-containing probe card > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170815 A1 - Document ID: US20190170815A1 - Status: Published application - Kind: A1 - Application number: 15/829,633 - Filed: 2017-12-01 - Published: 2019-06-06 - Earliest claimed: 2017-12-01 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Effendi Leobandung - Web page: https://patentgrep.com/patent/US20190170815A1 ## CPC - G01R 1/06783: {containing liquids} - G01R 31/2887: {involving moving the probe head or the IC under test; docking stations (moving single probes G01R1/06705; moving individual probes in multiple probes G01R1/07392)} - G01R 1/06755: {Material aspects} - G01R 31/2893: {Handling, conveying or loading, e.g. belts, boats, vacuum fingers (G01R31/2867 takes precedence; handling semiconductor devices or wafers during manufacture or treatment H10P72/00)} - G01R 1/07371: {using an intermediate card or back card with apertures through which the probes pass} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A probe card apparatus for wafer testing of a wafer under test, and a method of using the probe card for wafer testing. The probe card includes a printed circuit board having wafer testing circuitry. The probe card also includes a probe array including a slab having a plurality of probes, wherein each probe includes a volume of electrically-conductive fluid contained within a corresponding perforation of the slab that extends between a first surface and a second surface of the slab, wherein a first surface of each volume of electrically-conductive fluid substantially coincides with the first surface of the slab. ## Claims ### Claim 1 A method of using a probe card apparatus for wafer testing, the method comprising: loading a wafer under test into a wafer prober, the wafer comprising a plurality of solder bumps and the wafer prober comprising a test head interconnected to the probe card; aligning the probe card with respect to the wafer based on a pattern formed by the plurality of solder bumps, the pattern being formed with respect to one or more surfaces of the wafer; and testing the wafer by causing contact between a plurality of probes of the probe card and the plurality of solder bumps, the caused contact establishing an electromechanical interface between the wafer prober and the wafer during testing, wherein the probe card comprises: a printed circuit board having wafer testing circuitry interconnected to the wafer prober; and a probe array comprising a slab having the plurality of probes, wherein each probe comprises a volume of electrically-conductive fluid contained within a corresponding perforation of the slab that extends between a first surface and a second surface of the slab, wherein a first surface of each volume of electrically-conductive fluid substantially coincides with the first surface of the slab. ### Claim 2 (depends on 1) The method of claim 1, wherein the electrically-conductive fluid comprises elemental mercury. ### Claim 3 (depends on 1) The method of claim 1, wherein the caused contact between the plurality of probes and the plurality of solder bumps comprises: contact between a second surface of each volume of electrically-conductive fluid and a surface of each solder bump, wherein the second surface of each volume is located distally with respect to the first surface. ### Claim 4 (depends on 1) The method of claim 1, wherein the slab comprises a block or sheet of elastomeric material. ### Claim 5 (depends on 1) The method of claim 1, wherein the volume of electrically-conductive fluid is contained within the corresponding perforation by capillary action. ### Claim 6 (depends on 1) The method of claim 1, wherein a pitch of the probe array matches a pitch of the plurality of solder bumps. ### Claim 7 (depends on 1) The method of claim 1, wherein testing the wafer comprises: positioning the wafer spatially above the probe card. ### Claim 8 (depends on 1) The method of claim 1, wherein aligning the probe card with respect to the wafer comprises: moving either the probe card or the wafer with respect to the other in a plane parallel to the surface of the wafer, such that the plurality of solder bumps are aligned with the plurality of probes. ### Claim 9 (depends on 1) The method of claim 1, wherein the wafer is mounted to a vacuum chuck. ### Claim 10 (depends on 9) The method of claim 9, wherein causing the contact comprises: moving either the test head or the vacuum chuck a fixed distance in a linear direction oriented perpendicular to a surface of the wafer. ### Claim 11 (depends on 1) The method of claim 1, wherein causing the contact comprises: applying a load to the wafer by way of the elastomeric slab. ### Claim 12 (depends on 1) The method of claim 1, wherein the probe card is electromechanically interconnected to the test head by a space transformer. ### Claim 13 A probe card apparatus for wafer testing of a wafer under test, the probe card comprising: a printed circuit board having wafer testing circuitry; and a probe array comprising a slab having a plurality of probes, wherein each probe comprises a volume of electrically-conductive fluid contained within a corresponding perforation of the slab that extends between a first surface and a second surface of the slab, wherein a first surface of each volume of electrically-conductive fluid substantially coincides with the first surface of the slab. ### Claim 14 (depends on 13) The probe card of claim 13, wherein the electrically-conductive fluid comprises elemental mercury. ### Claim 15 (depends on 13) The probe card of claim 13, wherein a second surface of each volume of electrically-conductive fluid is located distally with respect to the first surface. ### Claim 16 (depends on 13) The probe card of claim 13, wherein the slab comprises a block or sheet of elastomeric material. ### Claim 17 (depends on 13) The probe card of claim 13, wherein the perforations of the elastomeric slab are formed by one of: reactive-ion etching, laser ablation, and sputtering. ### Claim 18 (depends on 13) The probe card of claim 13, wherein the slab is attached to the printed circuit board by an adhesive. ### Claim 19 (depends on 13) The probe card of claim 13, wherein the volume of electrically-conductive fluid is contained within the corresponding perforation by capillary action.