Abstract: The present invention is directed to a laminate having a layer construction of metal-insulating layer-metal or a layer construction of metal-insulating layer, which laminate meets conditions for developing large adhesive strength between the insulating layer and the metal, as well as to an insulating film and an electronic circuit using the laminate. The laminate has a layer construction of first metal layer/insulating layer/second metal layer or a layer construction of metal layer/insulating layer. The insulating layer 1 has a multilayer structure of two or more layers. The layers on the side of the adhesive interface with each metal layer (a copper foil 3 and an SUS foil 4), out of the layers constituting the insulating layer 1, each are a thermoplastic resin layer 2. The minimum value of the storage modulus at a temperature at or above Tg of the thermoplastic resin layer 2 is not more than 106 Pa.

Abstract: The present invention is directed to a laminate having a layer construction of metal-insulating layer-metal or a layer construction of metal-insulating layer, which laminate meets conditions for developing large adhesive strength between the insulating layer and the metal, as well as to an insulating film and an electronic circuit using the laminate. The laminate has a layer construction of first metal layer/insulating layer/second metal layer or a layer construction of metal layer/insulating layer. The insulating layer 1 has a multilayer structure of two or more layers. The layers on the side of the adhesive interface with each metal layer (a copper foil 3 and an SUS foil 4), out of the layers constituting the insulating layer 1, each are a thermoplastic resin layer 2. The minimum value of the storage modulus at a temperature at or above Tg of the thermoplastic resin layer 2 is not more than 106 Pa.

Abstract: A method of manufacturing a wireless suspension blank wherein three-layered laminate formed of a metallic layer having a spring property and a conductive layer laminated on the metallic layer through an electrically insulating layer are used. The laminate used is a laminate in which an insulating layer is formed of a core-insulating layer and adhesive layers laminated on both sides of the core-insulating layer, and the ratio of higher etching rate to lower etching rate of the respective layers of the insulating layer is between 6:1 and 1:1. The metallic layer and the conductive layer are processed by the photo etching method. The insulating layer is processed by the wet etching method.

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: The present invention relates to a production process which, in the production of an electronic component by wet etching of an insulating layer in a laminate, is low in cost, does not use any organic solvent, which poses a problem of waste treatment. The production process of an electronic component comprises the steps of: wet etching a laminate of conductive inorganic material layer—insulating layer—conductive inorganic material layer or a laminate of conductive inorganic material layer—insulating layer to pattern the conductive inorganic material layer; and then performing wet etching to pattern the insulating layer. The patterning of the insulating layer by wet etching is carried out in a continuous form using a dry film resist; and, the dry film resist is laminated by roll pressing onto the laminate under a reduced pressure of not more than 80 KPa.

Abstract: A laminate having a layer structure of first inorganic layer-insulating layer-second inorganic layer or inorganic layer-insulating layer, characterized in that the insulating layer comprises two or more resin layers containing a core insulating layer and an adhesive insulating layer, and at least one layer constituting the insulating layer comprises a polyimide resin which has a recurring unit represented by the general formula (1), has a glass transition temperature of 150° C. to 360° C., and exhibits a rate of dissolution in a basic solution of 3 &mgr;/min or more, preferably 5 ?m/min or more, most preferably 8 &mgr;/min or more.

Abstract: The present invention provides a radical generator having a naphthalimide structure or a crosslinking agent and a photosensitive compound having a function as a radical generator. A photoradical polymerization initiator of the present invention comprises a compound (a) having only one naphthalimide structure-containing group in one molecule. The radial generator of the present invention comprises a compound (c) having two or more naphthalimide structure-containing groups in one molecule and also functions as a crosslinking agent. A first photosensitive compound of the present invention comprises a compound (d) having a naphthalimide structure-containing group and an ethylenic unsaturated group in one molecule. A second photosensitive compound of the present invention comprises a polymer (e) of one or more radical polymerizable compounds containing the compound (d).

Abstract: The present invention relates to an insulator as an insulating layer in a laminate which can inhibit dusting at the time of use, more particularly an electronic circuit component to which the insulator has been applied, particularly a wireless suspension. The insulator comprises a laminate of one or more insulation unit layers etchable by a wet process, the insulator having been subjected to plasma treatment after wet etching. The insulator exists mainly as an insulating layer in a laminate having a layer construction of first inorganic material layer—insulating layer—second inorganic material layer or a layer construction of inorganic material layer—insulating layer, and at least a part of the inorganic material layer has been removed to expose the insulating layer.

Abstract: The present invention relates to a production process which, in the production of an electronic component by wet etching of an insulating layer in a laminate, is low in cost, does not use any organic solvent, which poses a problem of waste treatment, and can produce the electronic component with high accuracy and with significantly increased productivity.

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.

Abstract: The present invention is directed to a laminate having a layer construction of metal-insulating layer-metal or a layer construction of metal-insulating layer, which laminate meets conditions for developing large adhesive strength between the insulating layer and the metal, as well as to an insulating film and an electronic circuit using the laminate. The laminate has a layer construction of first metal layer/insulating layer/second metal layer or a layer construction of metal layer/insulating layer. The insulating layer 1 has a multilayer structure of two or more layers. The layers on the side of the adhesive interface with each metal layer (a copper foil 3 and an SUS foil 4), out of the layers constituting the insulating layer 1, each are a thermoplastic resin layer 2. The minimum value of the storage modulus at a temperature at or above Tg of the thermoplastic resin layer 2 is not more than 106 Pa.

Abstract: A wireless suspension blank is made using a two-layer laminate composed of a metallic layer with the spring property and an electrically insulating layer. The first method includes a first step for working the metallic layer by the photo etching method, a second step for forming a wiring part on the insulating layer by the semi-additive method and a third step for working the insulating layer by the wet-etching method. The second method includes a first step for working the metallic layer by the photo etching method, a second step for forming a wiring part on the insulating layer by the semi-additive method and a third step for working the insulating layer by the plasma etching method. The third method includes a first step for forming a wiring part on the metallic layer by the semi-additive method, a second step for working the metallic layer by the wet-etching method and a third step for working the insulating layer by the dry-etching method or the wet-etching method.

Abstract: A method of manufacturing a wireless suspension blank is a method of manufacturing a wireless blank in which three-layered laminate formed of a metallic layer having the spring property and a conductive layer laminated on the metallic layer through an electrically insulating layer are used, wherein as the laminate used is a laminate in which an insulating layer is formed of core-insulating layer and adhesive layers laminated on both sides of the core-insulating layer, and the ratio of higher etching rate to lower etching rate of the respective layers of the insulating layer is between 6:1 and 1:1. By the photo etching method processed are the metallic layer and the conductive layer. The insulating layer is processed by the wet etching method.