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AssigneeNippon Steel Chemical Co., Ltd.
InventorsMakoto Shimose, Hisashi Watanabe, Seigo Oka, Yuji Matsushita, Eri Kabemura
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This invention relates to laminates for use in HDD suspensions which are composed of a stainless steel base material and successive layers formed thereon of polyimides and an electrical conductor and in which the linear expansion coefficient of the polyimide layer is controlled in the range of 1×10−5/° C. to 3×10−5/° C. and the adhesive strength between stainless steel and polyimide and that between polyimide and electrical conductor are controlled at 0.5 kg/cm or more. This invention also relates to a process for preparing laminates for use in HDD suspensions comprising applying a solution of polyimide precursors or polyimides to a stainless steel base material with a thickness of 10 to 70 μm in one layer or more, drying, performing heat treatment at 250° C. or more to form a layer of polyimides with a thickness of 3 to 20 μm and a linear expansion coefficient of 1×10−5/° C. to 3×10−5/° C. and contact-bonding said layer of polyimides under heat to a layer of electrical conductor with a thickness of 3 to 20 μm. Laminates of this invention for use in HDD suspensions are practically free of deflection during etching and are suited for integrally-wired HDD suspensions.
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);
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 process for preparing laminates for use in HDD suspensions comprising applying a solution of polyimide precursors or polyimides in one layer or more to a stainless steel base material with a thickness of 10 to 70 μm, drying, performing heat treatment at 250° C. or more to form a layer of polyimides with a thickness of 3 to 20 μm and a linear expansion coefficient of 1×10−5/° C. to 3×10−5/° C., and contact-bonding said layer of polyimides under heat to a layer of electrical conductor with a thickness of 3 to 20 μm.
A process for preparing laminates for use in HDD suspensions comprising applying successively a solution of polyimides of high thermal expansion 1 or polyimide precursors of high thermal expansion 1, a solution of polyimide precursors of low thermal expansion, and a solution of polyimides of high thermal expansion 2 or polyimide precursors of high thermal expansion 2 to a stainless steel base material with a thickness of 10 to 70 μm, drying, and performing heat treatment at 250° C. or more to form a layer of polyimides with a thickness of 3 to 20 μm and a linear expansion coefficient of 1×10−5/° C., to 3×10−5/° C., and contact-bonding said layer of polyimides under heat to a layer of electrical conductor with a thickness of 3 to 20 μm.
Dependencies are inferred from the claim text.