Radio wave transmission film formation method by insulating chrome sputtering and resin molded product for smart entry unlocking / locking structure

摘要

PROBLEM TO BE SOLVED: To form a chrome film on a resin molded product by dividing it into several times by using a sputtering method to enhance the chrome plating-like design of an insulating radio wave transmitting film on the resin molded product. At the same time, a film is formed inexpensively using chromium. SOLUTION: A crack base material film forming step S2 in which a crack base material having a thermal expansion coefficient different from that of chromium is applied to the surface of a resin molded product W, and a crack base material film formed on the surface of the resin molded product W. A chrome film forming step S3 for forming a chrome film, and then a crack film forming step of heating the resin molded product W to cause cracks in the chrome film due to the difference in thermal expansion rate between the crack base material film and the chrome film. In S5 and the thin film forming apparatus, the buffer film forming step S6 for forming a transparent protective film as a buffer film on the resin molded product W on which the chromium film is formed, and the surface of the resin molded product W whose film thickness is adjusted. In order to secure the brightness of the chrome film, it further comprises a high-brightness chrome film forming step S7 for forming a chrome film. [Selection diagram] Fig. 1