# US 10,311,903 B2 · Method and system of testing slider body of thermally-assisted magnetic head > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,311,903 B2 - Document ID: US10311903B2 - Status: Granted - Kind: B2 - Application number: 15/649,961 - Filed: 2017-07-14 - Published: 2019-01-03 - Granted: 2019-06-04 - Earliest claimed: 2017-06-28 - Assignees: SAE Magnetics (H.K.) Ltd. - Applicants: SAE Magnetics (H.K.) Ltd. - Inventors: Seiichi Takayama; Takashi Honda; Ryuji Fujii; Ryo Hosoi; Kaichiu Cheung; Tsutomu Sasaki; Jingtao Lu; Fanglong Nie - Web page: https://patentgrep.com/patent/US10311903B2 ## CPC - G11B 5/455: Arrangements for functional testing of heads; Measuring arrangements for heads - G01R 33/032: using magneto-optic devices, e.g. Faraday {or Cotton-Mouton effect} - G01R 33/1207: {Testing individual magnetic storage devices, e.g. records carriers or digital storage elements (functional testing G06F11/00, G06F11/28)} - G11B 2005/0021: {Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal} - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A method of testing dynamic performances for a slider body of a thermally-assisted magnetic head includes: providing a slider body which is disconnected with a light source unit; removably mounting the slider body to a test head suspension assembly; keeping to provide a flat top beam to the slider body, the flat top beam being aligned with the optical waveguide, and a projection of an incident end of the optical waveguide being located within a light spot of the flat top beam; and testing the dynamic performance of the slider body. It can save the material cost and labor cost, and eliminate a precise optical alignment between an input light and an optical waveguide in the slider body to improve testing efficiency. ## Claims ### Claim 1 A method of testing dynamic performance for a slider body of a thermally-assisted magnetic head, the method comprising: providing the slider body, the slider body being disconnected with a light source unit and including a thermally-assisted magnetic head section, an air bearing surface and an optical waveguide; removably mounting the slider body to a test head suspension assembly loaded to a dynamic testing device; keeping to provide a flat top beam to the slider body along a direction vertical to an opposite surface of the air bearing surface, the flat top beam being aligned with the optical waveguide, and a projection of an incident end of the optical waveguide along said direction being located within a light spot of the flat top beam; and testing the dynamic performance of the slider body. ### Claim 2 (depends on 1) The method according to claim 1, wherein the projection of the incident end of the optical waveguide is located in a center of the light spot of the flat top beam. ### Claim 3 (depends on 1) The method according to claim 1, wherein the light spot of the flat top beam is in circle shape or oval shape. ### Claim 4 (depends on 1) The method according to claim 1, wherein the light spot of the flat top beam is in circle shape having a diameter that is less than 10 μm. ### Claim 5 (depends on 1) The method according to claim 1, wherein an incident light power on the incident end of the optical waveguide is in a range of 30 mW˜1000 mW. ### Claim 6 A system of testing dynamic performance for a slider body of a thermally-assisted magnetic head, the system comprising: a dynamic performance testing device, comprising a test head suspension assembly for supporting the slider body, the slider body being disconnected with a light source unit and including a thermally-assisted magnetic head section, an air bearing surface and an optical waveguide; and a light source supplying device, adapted for providing a flat top beam to the slider body along a direction vertical to an opposite surface of the air bearing surface, the flat top beam being aligned with the optical waveguide, and a projection of an incident end of the optical waveguide being located within a light spot of the flat top beam. ### Claim 7 (depends on 6) The system according to claim 6, wherein the projection of the incident end of the optical waveguide is located in a center of the light spot of the flat top beam. ### Claim 8 (depends on 6) The system according to claim 6, wherein the light spot of the flat top beam is in circle shape or oval shape. ### Claim 9 (depends on 6) The system according to claim 6, wherein the light spot of the flat top beam is in circle shape having a diameter that is less than 10 μm. ### Claim 10 (depends on 6) The system according to claim 6, wherein an incident light power on the incident end of the optical waveguide is in a range of 30 mW˜1000 mW. ### Claim 11 (depends on 6) The system according to claim 6, wherein the light source supplying device comprises a laser device and a flat top beam shaper. ### Claim 12 A method of testing dynamic performance for a slider body of a thermally-assisted magnetic head, the method comprising: providing the slider body, the slider body being disconnected with a light source unit and including a thermally-assisted magnetic head section, an air bearing surface and an optical waveguide; removably mounting the slider body to a test head suspension assembly loaded to a dynamic testing device, the test head suspension assembly being firmly connected with a test light source unit, and the test light source unit being configured to face to an opposite surface of the air bearing surface; controlling the test light source unit to provide a Gaussian beam to the slider body, the Gaussian beam aligning with the optical waveguide; and testing the dynamic performance of the slider body. ### Claim 13 A method of testing dynamic performance for a slider body of a thermally-assisted magnetic head, the method comprising: providing the slider body, the slider body being disconnected with a light source unit and including a thermally-assisted magnetic head section, an air bearing surface and an optical waveguide; removably mounting the slider body to a test head suspension assembly loaded to a dynamic testing device; keeping to provide a Gaussian beam to the slider body along a direction vertical to an opposite surface of the air bearing surface, the Gaussian beam aligning with the optical waveguide; controlling the Gaussian beam to move synchronously with track motions of the slider body; and testing the dynamic performance of the slider body. ### Claim 14 A method of testing dynamic performance for a slider body of a thermally-assisted magnetic head, the method comprising: providing the slider body and a light source unit, the light source unit being temporarily attached on an opposite surface of an air bearing surface of the slider body; aligning a Gaussian beam emitting from the light source unit with an optical waveguide of the slider body; and testing the dynamic performance of the slider body.