LAMINATE FOR HDD SUSPENSION AND ITS MANUFACTURE

摘要

A polyimide resin layer and a conductor layer are successively formed on a stainless steel substrate to form a laminate for HDD suspension. The linear expansion coefficient of the polyimide resin layer is within a range of 1 x 10<-6> - 3 x 10<-5>/ DEG C. The bonding strengths between the stainless steel substrate and the polyimide resin layer and between the polyimide resin layer and the conductor layer are not less than 0.5 kg/cm. Polyimide precursor solution or polyimide resin solution is applied to the stainless steel substrate to form one or more layers with a thickness of 10 - 70 mu m. The layers are dried and subjected to a heat treatment at a temperature higher than 250 DEG C to form a polyimide resin layer whose thickness is 3 - 20 mu m and whose linear expansion coefficient is 1 x 10<-6> - 3 x 10<-5>/ DEG C. Then the conductor layer with a thickness of 3 - 20 mu m is joined to the resin layer by thermocompression bonding. Such a laminate for HDD suspension warps little when it is subjected to an etching treatment and is suitable for HDD suspension with unified wiring.