| 摘要 |
PURPOSE:To obtain a magnetic head core having high reliability by irradiating the surface of the gap bar of a magnetic head core with the prescribed laser beam in an aqueous solution of phosphoric acid at the prescribed scanning speed and working a high-precision track by a laser-induced etching method. CONSTITUTION:The track width 13 of a magnetic head core 16 is subjected to laser-beam machining by applying a laser beam 8 of <=50mum diameter having a power P of 50-1,900mW to a gap bar 4 in a 10-90wt.% aqueous solution of phosphoric acid at a scanning speed V in a range of 2-200mum/sec and satisfying the inequalities, V<=0.31P+34 and V<=-0.14P+271, simultaneously and then carrying out working by means of laser-induced etching. By the above procedure, a chemical reaction of the gap bar 4 with phosphoric acid is induced and the above aqueous solution of phosphoric acid begins to flow from the direction of advance of a working point toward the rear of the working point. As a result, the supply of phosphoric acid to the working point is always performed, and the removal of machined chips is rapidly carried out and the laser-induced etching is allowed to proceed. |
