Abstract: The present invention provides a laminate comprising an insulating layer having suppressed dusting properties, an insulating film comprising the insulating layer, and an electronic circuit component comprising a pattern of the insulating layer. The laminate has a layer construction of first inorganic material layer-insulating layer-second inorganic material layer or a layer construction of inorganic material layer-insulating layer. The insulating layer comprises a laminate of two or more wet etchable insulating unit layers. At the interface between the inorganic material layer and the insulating layer, surface irregularities of the inorganic material layer have been transferred onto the surface of the insulating layer. The average height of the surface irregularities transferred onto the insulating layer is less than the thickness of the outermost insulating unit layer in the insulating layer.

Abstract: This invention relates to a laminate comprising an insulating polyimide resin layer etchable by an aqueous alkaline solution and a metal foil. The laminate has an insulating resin layer composed of a plurality of polyimide resin layers on the metal foil and the insulating resin layer has at least one polyimide resin layer (A) with a coefficient of linear thermal expansion (CTE) of 30×10?6/° C. or less and at least one polyimide resin layer (B) with a glass transition temperature (Tg) of 300° C. or below, the layer in contact with the metal foil is the polyimide resin layer (B), the bonding strength between the metal foil and the polyimide resin layer (B) in contact therewith is 0.5 kN/m or more, and the average rate of etching of the insulating resin layer by a 50 wt % aqueous solution of potassium hydroxide at 80° C. is 0.5 ?m/min or more. The laminate is useful for flexible printed circuits and the like.

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: The present invention provides a laminate comprising an insulating layer having suppressed dusting properties, an insulating film comprising the insulating layer, and an electronic circuit component comprising a pattern of the insulating layer. The laminate has a layer construction of first inorganic material layer-insulating layer-second inorganic material layer or a layer construction of inorganic material layer-insulating layer. The insulating layer comprises a laminate of two or more wet etchable insulating unit layers. At the interface between the inorganic material layer and the insulating layer, surface irregularities of the inorganic material layer have been transferred onto the surface of the insulating layer. The average height of the surface irregularities transferred onto the insulating layer is less than the thickness of the outermost insulating unit layer in the insulating layer.

Abstract: This invention relates to an HDD suspension and a process for its manufacture with high productivity and reliability. The HDD suspension of this invention is manufactured from a laminate composed of a stainless steel substrate, an insulating resin layer and a metal foil by wet-etching the laminate by the use of a basic fluid. The insulating layer of the laminate is composed of plural layers of polyimide, every constituent layer exhibits a mean etching rate of 0.5 ?M/min or more by a 50 wt % aqueous solution of KOH at 80° C., the layers in contact with the stainless steel substrate and the metal foil are those of polyimide (B) exhibiting a glass transition temperature of 300° C. or less and the adhesive strength between the layer of polyimide (B) and either the stainless steel substrate or the metal foil is 0.5 kN/m or more.

Abstract: The invention relates to a substrate for HDD suspension. A laminate for HDD suspension comprises a stainless steel layer, a polyimide resin layer, and a conductor layer. The conductor layer is composed of a copper or copper alloy foil having a thickness of 14 ?m or less, a tensile strength of 400 MPa, and a conductance of 65% or more. A suspension formed of such a laminate facilitates the control of the flying height of the slider of the suspension essential to great progress of the technology for higher capacity of HDDs, facilitates the impedance control improves the tension rate, reduces the loss of electric signal, facilitates machining of the shape of the flying lead, and provides durability.

Abstract: This invention relates to a laminate which changes in dimension to such a small extent as not to cause curling and warpage when the ambient humidity changes and is useful for flexible printed wiring boards. The laminate possesses a polyimide layer or layers of polyimides formed on a conductor by coating and at least one of the polyimide layers is composed of polyimide of low hygroscopic expansion obtained by the reaction of diamines containing 20 mol % or more of 4,4?-diamino-2,2?-dimethylbiphenyl with a tetracarboxylic acid compound and exhibiting a coefficient of linear hygroscopic expansion of 15×10?6/% RH or less.

Abstract: The present invention provides a laminate comprising an insulating layer having suppressed dusting properties, an insulating film comprising the insulating layer, and an electronic circuit component comprising a pattern of the insulating layer. The laminate has a layer construction of first inorganic material layer-insulating layer-second inorganic material layer or a layer construction of inorganic material layer-insulating layer. The insulating layer comprises a laminate of two or more wet etchable insulating unit layers. At the interface between the inorganic material layer and the insulating layer, surface irregularities of the inorganic material layer have been transferred onto the surface of the insulating layer. The average height of the surface irregularities transferred onto the insulating layer is less than the thickness of the outermost insulating unit layer in the insulating layer.

Abstract: This invention relates to a laminate comprising an insulating polyimide resin layer etchable by an aqueous alkaline solution and a metal foil. The laminate has an insulating resin layer composed of a plurality of polyimide resin layers on the metal foil and the insulating resin layer has at least one polyimide resin layer (A) with a coefficient of linear thermal expansion (CTE) of 30×10−6/° C. or less and at least one polyimide resin layer (B) with a glass transition temperature (Tg) of 300° C. or below, the layer in contact with the metal foil is the polyimide resin layer (B), the bonding strength between the metal foil and the polyimide resin layer (B) in contact therewith is 0.5 kN/m or more, and the average rate of etching of the insulating resin layer by a 50 wt % aqueous solution of potassium hydroxide at 80° C. is 0.5 &mgr;m/min or more. The laminate is useful for flexible printed circuits and the like.

Abstract: This invention relates to an HDD suspension and a process for its manufacture with high productivity and reliability. The HDD suspension of this invention is manufactured from a laminate composed of a stainless steel substrate, an insulating resin layer and a metal foil by wet etching the laminate by the use of a basic fluid. The insulating layer of the laminate is composed of plural layers of polyimide, every constituent layer exhibits a mean etching rate of 0.5 &mgr;m/min or more by a 50 wt % aqueous solution of KOH at 80° C., the layers in contact with the stainless steel substrate and the metal foil are those of polyimide (B) exhibiting a glass transition temperature of 300° C. or less and the adhesive strength between the layer of polyimide (B) and either the stainless steel substrate or the metal foil is 0.5 kN/m or more.