# US 2014/0192341 A1 · Fixture planarity evaluation method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192341 A1 - Document ID: US20140192341A1 - Status: Published application - Kind: A1 - Application number: 13/735,103 - Filed: 2013-01-07 - Published: 2014-07-10 - Earliest claimed: 2013-01-07 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Sarah H. Knickerbocker; Jerry Allen Gorrell; Christopher Lee Tessler - Web page: https://patentgrep.com/patent/US20140192341A1 ## CPC - G01B 11/30: for measuring roughness or irregularity of surfaces - G01B 11/0608: {Height gauges} - G01B 11/272: {using photoelectric detection means} - H10P 72/0428: {Apparatus for mechanical treatment or grinding or cutting} - H10P 72/0616: {Monitoring of warpages, curvatures, damages, defects or the like} - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract Methods for determining the planarity of two components of a semiconductor processing tool, such as a 3D wafer bonder are disclosed. The two components may be fixtures, chucks, or platens of the tool. A test wafer comprising multiple solder balls is compressed and the deformity of multiple solder balls is measured to assess the planarity of the tool. The measurement of the deformed solder balls may be performed manually, or with an automated wafer inspection tool, which may use lasers to measure the height of each solder ball. The planarity of the two components is computed based on the height of the deformed solder balls. ## Claims ### Claim 1 A method of measuring planarity of two components of a semiconductor processing tool comprising: compressing a wafer with the semiconductor processing tool comprising a first fixture and a second fixture, wherein the wafer comprises a plurality of solder balls on a surface of the wafer; measuring deformity of multiple solder balls from the plurality of solder balls; and determining planarity of the first fixture with respect to the second fixture. ### Claim 2 (depends on 1) The method of claim 1, wherein the wafer comprises between 12 and 48 solder balls. ### Claim 3 (depends on 1) The method of claim 1, wherein the wafer comprises between 1,000 and 5,000 solder balls. ### Claim 4 (depends on 1) The method of claim 1, wherein the wafer comprises between 80,000 and 2,000,000 solder balls. ### Claim 5 (depends on 1) The method of claim 1, wherein the compressing occurs at a force ranging between 1 kilo-Newton and 1.5 kilo-Newtons. ### Claim 6 (depends on 1) The method of claim 1, wherein the compressing occurs at a force ranging between 1.8 kilo-Newtons and 2.4 kilo-Newtons. ### Claim 7 (depends on 1) The method of claim 1, wherein the wafer is heated to a temperature ranging from about 100 degrees Celsius to about 150 degrees Celsius prior to compression. ### Claim 8 (depends on 1) The method of claim 1, wherein the wafer is heated to a temperature ranging from about 180 degrees Celsius to about 275 degrees Celsius prior to compression. ### Claim 9 (depends on 1) The method of claim 1, wherein compressing a wafer comprises compressing a wafer comprising solder balls comprised of an alloy comprised of lead and tin. ### Claim 10 (depends on 1) The method of claim 1, wherein compressing a wafer comprises compressing a wafer comprising solder balls comprised of an alloy comprised of SnAg. ### Claim 11 (depends on 1) The method of claim 1, wherein compressing a wafer comprises compressing a wafer comprising solder balls comprised of an alloy comprised of SnCu. ### Claim 12 (depends on 1) The method of claim 1, wherein compressing a wafer comprises compressing a wafer comprising solder balls comprised of an alloy comprised of SnAgCu. ### Claim 13 (depends on 1) The method of claim 1, wherein compressing a wafer comprises compressing a wafer comprising solder balls having a height ranging between about 50 micrometers to about 100 micrometers. ### Claim 14 (depends on 1) The method of claim 1, wherein measuring deformity of multiple solder balls from the plurality of solder balls is performed via a microscope. ### Claim 15 (depends on 1) The method of claim 1, wherein measuring deformity of multiple solder balls from the plurality of solder balls is performed via an automated wafer inspection tool. ### Claim 16 (depends on 1) The method of claim 1, wherein determining planarity of the first fixture with respect to the second fixture comprises: identifying the tallest solder ball on the wafer after the wafer is compressed; identifying the shortest solder ball on the wafer after the wafer is compressed; and subtracting the height of the shortest solder ball from the height of the tallest solder ball to compute a planarity value. ### Claim 17 (depends on 16) The method of claim 16, further comprising: computing a planarity line; and using the slope of the planarity line to determine if planarity of the first fixture with respect to the second fixture is within a desired tolerance range. ### Claim 18 A method of measuring planarity of two components of a semiconductor processing tool comprising: compressing a first wafer with the semiconductor processing tool, wherein the first wafer is secured in a first fixture, and wherein the first wafer comprises a plurality of solder balls on a surface of the first wafer, and wherein a second fixture holds a second wafer, such that the second wafer compresses the solder balls of the first wafer; measuring deformity of multiple solder balls from the plurality of solder balls; and determining the planarity of the first fixture with respect to the second fixture. ### Claim 19 A method of measuring planarity of two components of a semiconductor processing tool comprising: heating a wafer to a temperature ranging from 260 degrees Celsius to 275 degrees Celsius, wherein the wafer comprises between 90,000 and 100,000 solder balls on a surface of the wafer; compressing a wafer secured in a first fixture of the semiconductor processing tool, wherein the wafer is compressed with a second fixture of the semiconductor processing tool; measuring deformity of multiple solder balls on the wafer; and determining planarity of the first fixture with respect to the second fixture. ### Claim 20 (depends on 19) The method of claim 19, wherein measuring deformity of multiple solder balls comprises using a laser measuring tool.