| 摘要 |
PURPOSE:To enable to bond with external circuit with high reliability, by assuring the high film thickness of the wiring electrode having massproductivity and ease of manufacture so that strong wire bonding can freely be made. CONSTITUTION:The aluminum film 2 about 2000Angstrom in film thickness is formed on the piezoelectric substrate 1, the chromium film 3 about 500Angstrom in film thickness is formed, and the gold film 4 in about 2000Angstrom in film thickness is formed. On the multi-layered construction film metal surface, a given resist pattern consisting of the wiring electrode 5 and read screen electrode 6 is formed. Further, unnecessary part is removed by etching by taking the resist pattern as a mask. The wiring electrode 5 of pattern removed for unnecessary part has the area more than twice in comparison with the reed screen electrode 6. Next, chemical etching is made until the reed screen part of the chromium film 3 can completely be removed. After the process befor, the wiring electrode having sufficient film thickness consisting of the reed screen electrode of aluminum metal film 2, metal film 3 and gold film 4, is formed. |
