# US 12,765,287 B2 · Method for processing workpiece > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,765,287 B2 - Document ID: US12765287B2 - Status: Granted - Kind: B2 - Application number: 18/887,652 - Filed: 2024-09-17 - Published: 2025-04-03 - Granted: 2026-10-13 - Earliest claimed: 2023-10-02 - Assignees: Disco Corporation - Applicants: Disco Corporation - Inventors: Atsushi Maeda; Toshiyuki Kitamura - Web page: https://patentgrep.com/patent/US12765287B2 ## CPC - H10P 34/42: with electromagnetic radiation, e.g. laser annealing (laser cutting H10P54/20) - B23K 26/0624: {using ultrashort pulses, i.e. pulses of 1 ns or less} - B23K 26/356: by shock processing - B23K 26/53: for modifying or reforming the material inside the workpiece, e.g. for producing break initiation cracks - B23K 2103/56: {being semiconducting} - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM ## Abstract A method for processing a workpiece includes a setting step of setting a planned processing region, a boundary processing step of processing a boundary dividing the planned processing region into a plurality of regions or a boundary dividing the planned processing region and another region from each other, a correlation threshold value generating step of generating a correlation threshold value from correlation between energy per pulse and a pulse interval of a first laser beam configured to form a horny layer in the planned processing region, and an energy and pulse interval setting step of setting the energy per pulse of the first laser beam equal to or higher than the correlation threshold value and setting the pulse interval of the first laser beam equal to or less than the correlation threshold value. ## Claims ### Claim 1 A method for processing a workpiece, the method comprising: a setting step of setting a planned processing region; a boundary processing step of processing a boundary dividing the planned processing region into a plurality of regions or a boundary dividing the planned processing region and another region from each other; a correlation threshold value generating step of generating a correlation threshold value from correlation between energy per pulse and a pulse interval of a first laser beam configured to form a horny layer in the planned processing region; an energy and pulse interval setting step of setting the energy per pulse of the first laser beam equal to or higher than the correlation threshold value and setting the pulse interval of the first laser beam equal to or less than the correlation threshold value; a horny layer forming step of forming the horny layer by irradiating the planned processing region with the first laser beam, after the setting step, the boundary processing step, and the energy and pulse interval setting step are performed; and a peeling step of peeling off the horny layer from the workpiece. ### Claim 2 (depends on 1) The method for processing the workpiece according to claim 1, wherein the boundary processing step includes a step of forming a groove at the boundary of the workpiece by irradiating the workpiece with a second laser beam having a wavelength absorbable by the workpiece. ### Claim 3 (depends on 1) The method for processing the workpiece according to claim 1, wherein the boundary processing step includes a step of forming a modified layer and a crack extending from the modified layer in an internal part corresponding to the boundary of the workpiece, by irradiating the workpiece with a third laser beam having a wavelength transmissible through the workpiece. ### Claim 4 (depends on 2) The method for processing the workpiece according to claim 2, wherein the boundary processing step includes a step of forming a crack extending along a surface direction of the workpiece, by irradiating the workpiece with a fourth laser beam having a wavelength transmissible through the workpiece while positioning a condensing point of the fourth laser beam at a position corresponding to the boundary of the workpiece and at a depth corresponding to a thickness by which the horny layer is to be formed from one surface of the workpiece. ### Claim 5 (depends on 3) The method for processing the workpiece according to claim 3, wherein the boundary processing step includes a step of forming the crack extending in a surface direction of the workpiece, by irradiating the workpiece with a fourth laser beam having a wavelength transmissible through the workpiece while positioning a condensing point of the fourth laser beam at a position corresponding to the boundary of the workpiece and at a depth corresponding to a thickness by which the horny layer is to be formed from one surface of the workpiece. ### Claim 6 (depends on 1) The method for processing the workpiece according to claim 1, wherein the horny layer is generated by a chain of compressive plastic strains occurring when such a high thermal stress occurs that a local part of the workpiece irradiated with the laser beam attempts to expand rapidly and the high thermal stress is restrained by surroundings having a low temperature and exceeds a yield stress of the workpiece. ### Claim 7 (depends on 1) The method for processing the workpiece according to claim 1, wherein the correlation threshold value is defined by an approximate equation, and when an axis of abscissas is set to indicate the pulse interval (μs) and an axis of ordinates is set to indicate the energy per pulse (μJ), the approximate equation is expressed by energy per pulse=a{b−(pulse interval/μs−c)2} where coefficients a, b, and c are set according to a type of the workpiece. ### Claim 8 (depends on 7) The method for processing the workpiece according to claim 7, wherein, in a case where the workpiece is silicon, settings are made such that a=4, b=1, and c=0.9, the approximate equation is expressed by energy per pulse=4{1−(pulse interval/μs−0.9)2}, and the pulse interval is set in a range equal to or more than 0.02 μs but equal to or less than 0.8 μs. ### Claim 9 (depends on 1) The method for processing the workpiece according to claim 1, wherein an irradiation pitch of the laser beam used in the horny layer forming step is set at 10 to 200 nm. ### Claim 10 (depends on 1) The method for processing the workpiece according to claim 1, wherein a pulse width of the laser beam is set in a range of 0.3 to 100 ps.