# US 9,437,226 B1 · Method of testing 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 9,437,226 B1 - Document ID: US9437226B1 - Status: Granted - Kind: B1 - Application number: 14/710,735 - Filed: 2015-05-13 - Granted: 2016-09-06 - Earliest claimed: 2015-05-13 - Assignees: SAE Magnetics (H.K.) Ltd. - Applicants: SAE Magnetics (H.K.) Ltd. - Inventors: Tadatoshi Koba; Seiichi Takayama; Ryuji Fujii; Takashi Honda; Osamu Harakawa; Masahiro Kuribayashi - Web page: https://patentgrep.com/patent/US9437226B1 ## CPC - G11B 5/455: Arrangements for functional testing of heads; Measuring arrangements for heads - G11B 5/127: Structure or manufacture of heads, e.g. inductive - G11B 5/012: Recording on, or reproducing or erasing from, magnetic disks (G11B17/00, G11B19/00 take precedence) - G11B 5/3173: {Batch fabrication, i.e. producing a plurality of head structures in one batch} - G11B 5/6088: {Optical waveguide in or on flying head} - 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) ## Abstract A method of testing a TAMH includes providing a slider body having a waveguide embedded therein with an incidence end extending toward a back surface of the slider body; providing a light source unit including a light source and a unit substrate; coating a bonding material layer on the back surface, under the bottom, or both on the back surface and under the bottom of the unit substrate; coating a localization material layer on the back surface; aligning the light source unit to the slider body; causing a light emitted from the light source and allowed to be incident on the incidence end to anneal the localization material layer to generate an annealing mark; removing the light source unit or the light source from the slider body; and measuring a position offset between the annealing mark and the incidence end. The method can evaluate alignment accuracy of a slider body and a light source unit in two dimensional directions. ## Claims ### Claim 1 A method of testing a thermally-assisted magnetic head, the method comprising: providing a slider body having a waveguide embedded therein with an incidence end extending toward a back surface of the slider body; providing a light source unit including a light source and a unit substrate for supporting the light source; coating a bonding material layer on the back surface, under the bottom, or both on the back surface and under the bottom of the unit substrate; coating a localization material layer on the back surface to cover the incidence end of the waveguide; aligning the light source unit to the slider body; causing a light emitted from the light source and allowed to be incident on the incidence end of the waveguide to anneal the localization material layer to generate an annealing mark; removing the light source unit or the light source from the slider body; and measuring a position offset between the annealing mark of the localization material layer and the incidence end of the waveguide. ### Claim 2 (depends on 1) The method of testing a thermally-assisted magnetic head according to claim 1, wherein further comprises melting the bonding material layer and then bonding the slider body and the light source unit after aligning the light source unit to the slider body. ### Claim 3 (depends on 1) The method of testing a thermally-assisted magnetic head according to claim 1, wherein the bonding material layer is made of a material selected from a group consisting of tin, tin alloy, indium, indium alloy, lead alloy and bismuth alloy. ### Claim 4 (depends on 1) The method of testing a thermally-assisted magnetic head according to claim 1, wherein the localization material layer is made of a material selected from a group consisting of tin, tin alloy, indium, indium alloy, lead alloy and bismuth alloy. ### Claim 5 (depends on 1) The method of testing a thermally-assisted magnetic head according to claim 1, wherein the light source is a laser diode or a light emitting diode. ### Claim 6 (depends on 1) The method of testing a thermally-assisted magnetic head according to claim 1, wherein the method of removing the light source unit or the light source includes cutting, pulling, grinding, lapping or polishing. ### Claim 7 (depends on 1) The method of testing a thermally-assisted magnetic head according to claim 1, wherein the thickness of the localization material layer is in a range of 10 angstrom to 10000 angstrom. ### Claim 8 (depends on 1) The method of testing a thermally-assisted magnetic head according to claim 1, wherein the localization material layer covers the entire back surface of the slider body. ### Claim 9 (depends on 1) The method of testing a thermally-assisted magnetic head according to claim 1, wherein a current supplied to the light source unit for generating a light to anneal the localization material layer is in a range of 10 milliamperes to 200 milliamperes. ### Claim 10 (depends on 1) A method of manufacturing a thermally-assisted magnetic head, the method comprising the method of testing a thermally-assisted magnetic head according to claim 1 and making a position correction to the positions between the light source unit and the slider body according to the position offset.