Abstract: There is provided a substrate material, for an HDD suspension, which has excellent adhesion between a stainless steel foil and an insulating resin layer and maintains high etching performance by preventing metal components in the stainless steel from diffusing into the insulating resin layer. The substrate material for an HDD suspension of the invention is a material obtained by shaping a stainless steel foil, wherein, on the surface of the stainless steel foil and on at least one side thereof, there are laminated, at least, a covering layer made chiefly of either one or both of a metal oxide and a metal hydroxide with chromium excluded as the metal species, and an insulating resin layer.

Abstract: This invention relates to a laminate which is excellent in heat resistance after moisture absorption required in a lead-free solder joint, and is suitable for use in flexible printed wiring boards or HDD suspensions. The laminate for electronic materials of this invention is constituted of a conductor layer and an insulating resin layer having a polyimide-based resin layer (A) and a polyimide-based resin layer (B). The polyimide-based resin layer (A) constituting the insulating layer includes a polyimide-based resin obtained by reacting a diamine containing 40 mol % or more of 4,4?-diamino-2,2?-dimethylbiphenyl with an aromatic tetracarboxylic acid, and the polyimide-based resin layer (B) includes a polyimide-based resin containing 80 mol % or more of a structural unit generated from bis(4-aminophenoxy)benzene or 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and pyromellitic acid, benzophenonetetracarboxylic acid, diphenylsulfonetetracarboxylic acid or biphenyltetracarboxylic acid.

Abstract: This invention relates to a laminate which is excellent in heat resistance after moisture absorption required in a lead-free solder joint, and is suitable for use in flexible printed wiring boards or HDD suspensions. The laminate for electronic materials of this invention is constituted of a conductor layer and an insulating resin layer having a polyimide-based resin layer (A) and a polyimide-based resin layer (B). The polyimide-based resin layer (A) constituting the insulating layer includes a polyimide-based resin obtained by reacting a diamine containing 40 mol % or more of 4,4′-diamino-2,2′-dimethylbiphenyl with an aromatic tetracarboxylic acid, and the polyimide-based resin layer (B) includes a polyimide-based resin containing 80 mol % or more of a structural unit generated from bis(4-aminophenoxy)benzene or 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and pyromellitic acid, benzophenonetetracarboxylic acid, diphenylsulfonetetracarboxylic acid or biphenyltetracarboxylic acid.