# US 12,222,322 B2 · System and method for the acoustic detection of cracks in a semiconductor substrate > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,222,322 B2 - Document ID: US12222322B2 - Status: Granted - Kind: B2 - Application number: 17/401,380 - Filed: 2021-08-13 - Published: 2022-02-17 - Granted: 2025-02-11 - Earliest claimed: 2020-08-14 - Assignees: Infineon Technologies AG - Applicants: Infineon Technologies AG - Inventors: Oliver Nagler; Marianne Unterreitmeier - Web page: https://patentgrep.com/patent/US12222322B2 ## CPC - G01N 29/045: {by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks (measuring resonant frequency G01H13/00; measuring strength properties by application of mechanical stress G01N3/00)} - G01N 29/14: using acoustic emission techniques {(echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00)} - H10P 74/203: {Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects} - G01N 29/12: by measuring frequency or resonance of acoustic waves {(measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00)} - G01N 2291/014: Resonance or resonant frequency - G01N 2291/023: Solids - G01N 2291/2697: Wafer or (micro)electronic parts - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A system and method for the acoustic detection of cracks in a semiconductor substrate is disclosed. In one example, the system includes a force generating unit configured to apply a force onto the semiconductor substrate, a detector unit comprising a resonating indenter and an acoustic emission sensor coupled to the resonating indenter, and an evaluation unit configured to evaluate acoustic signals detected by the detector unit and configured to determine whether a crack has occurred based on the detected signals. The resonating indenter is configured to contact the semiconductor substrate at a lateral distance from the force generating unit, and wherein the force generating unit and the resonating indenter are configured to contact the semiconductor substrate on the same side. ## Claims ### Claim 1 A system for the acoustic detection of cracks in a semiconductor substrate, the system comprising: a force generating unit configured to press down onto a semiconductor substrate and thereby apply a force onto the semiconductor substrate; a detector unit separate from the force generating unit and comprising a resonating indenter and an acoustic emission sensor coupled to the resonating indenter; and an evaluation unit configured to evaluate acoustic signals detected by the detector unit and configured to determine, whether a crack has occurred based on the detected signals, wherein the resonating indenter is configured to contact the semiconductor substrate at a lateral distance from the force generating unit, and wherein the force generating unit and the resonating indenter are configured to contact the semiconductor substrate on the same side. ### Claim 2 (depends on 1) The system of claim 1, wherein the force generating unit comprises a probe card of a testing equipment for electrical testing, or a bondhead of a wire bonding equipment, or a saw of a dicing equipment. ### Claim 3 (depends on 1) The system of claim 1, further comprising: one or more additional detector units, wherein the resonating indenters of the detector units are configured to contact the semiconductor substrate at locations that are spaced apart from one another, and wherein the evaluation unit is configured to determine the location at which a crack occurred based on the signals detected by the detector units. ### Claim 4 (depends on 1) The system of claim 1, wherein the resonance frequencies of the resonating indenter and the acoustic emission sensor are attuned to one another. ### Claim 5 (depends on 4) The system of claim 4, wherein the resonance frequencies are in the range of 100 kHz to 1 MHz. ### Claim 6 (depends on 1) The system of claim 1, wherein the resonating indenter comprises a tip and wherein the tip has a diameter of 20 μm or less. ### Claim 7 (depends on 6) The system of claim 6, wherein the tip comprises diamond. ### Claim 8 (depends on 1) The system of claim 1, wherein the resonating indenter has a length of 10 mm or more. ### Claim 9 (depends on 1) The system of claim 1, wherein the lateral distance is 1 cm or more. ### Claim 10 (depends on 1) The system of claim 1, wherein due to the lateral distance the system is configured to differentiate an acoustic signal generated by a crack in the semiconductor substrate from an acoustic signal generated by a plastic deformation in the semiconductor substrate. ### Claim 11 (depends on 1) The system of claim 1, wherein the force generating unit and/or the detector unit are moveable across a plane parallel to the semiconductor substrate. ### Claim 12 (depends on 1) The system of claim 1, wherein the detector unit is configured to press the probe tip onto the semiconductor substrate with a force of 1000 mN or less. ### Claim 13 A method for the acoustic detection of cracks in a semiconductor substrate, the method comprising: pressing down onto a semiconductor substrate with a force generating unit and thereby applying a force onto the semiconductor substrate; contacting the semiconductor substrate with a resonating indenter of a detector unit separate from the force generating unit, the detector unit further comprising an acoustic emission sensor coupled to the resonating indenter; and evaluating with an evaluation unit acoustic signals detected by the detector unit and determining, whether a crack has occurred based on the detected signals, wherein the resonating indenter is configured to contact the semiconductor substrate at a lateral distance from the force generating unit, and wherein the force generating unit and the resonating indenter are configured to contact the semiconductor substrate on the same side. ### Claim 14 (depends on 13) The method of claim 13, wherein the method is performed during electrical testing of the semiconductor substrate, or during wire bonding, or during dicing. ### Claim 15 (depends on 13) The method of claim 13, further comprising: determining the location of a crack in the semiconductor substrate by using more than one detector units, wherein the more than one detector units contact the semiconductor substrate at different locations. ### Claim 16 (depends on 15) The method of claim 15, further comprising: determining in which semiconductor device of a plurality of semiconductor devices comprised in the semiconductor substrate the crack occurred. ### Claim 17 (depends on 13) The method of claim 13, wherein due to the size of the lateral distance, the detector unit is sensitive to acoustic signals of cracks but not to acoustic signals of plastic deformations caused by the force generating unit in the semiconductor substrate. ### Claim 18 (depends on 13) The method of claim 13, wherein the lateral distance is 1 cm or more.