Patent ID: 6203918
Filing Date: 2001-03-20
Classification: G11B,H05K,Y10T

Abstract:
Laminates for use in HDD suspensions comprising steel base material and successive layers formed thereon of polyimides and an electrical conductor wherein said stainless steel base material and said layer of polyimides satisfy the following conditions (a) to (d);(a) the layer of polyimides shows a linear expansion coefficient in the range from 1.times.10.sup.-5 /.degree. C. to 3.times.10.sup.-5 /.degree. C.,(b) the layer of polyimides shows an etching rate of 0.5 .mu.m/min or more when immersed in 100%-hydrated hydrazine at 50.degree. C.,(c) the stainless steel base material shows heat shrinkage of 0.025% or less in each of the transverse and longitudinal directions when subjected to heat treatment at 330.degree. C. for 30 minutes in air, and(d) the stainless steel base material shows an average roughness along center line (Ra) of 20 to 300 nm on the surface to be laminated to the layer of polyimides, and, still more, the adhesive strength between the layers of stainless steel base material and polyimides and that between the layers of polyimides and electrical conductor are 0.5 kg/cm or more, respectively.