Abstract: A photosensitive resin composition which is excellent in flame resistance, resolution and flexibility, and substantially free from deposition of components thereof to prevent contamination of a product. The photosensitive resin composition comprises: (A) a cyclic phosphazene compound represented by the following general formula (1): wherein at least one of the Rs is an organic group having the urethane(meth)acrylate structure represented by the following general formula (2) and n is a positive number of 2 to 5: wherein R1 is a hydrogen atom or a methyl group; (B) a carboxyl-containing linear polymer obtained by polymerizing an ethylenically unsaturated compound through addition polymerization; (C) an epoxy resin; (D) an ethylenically unsaturated group-containing polymerizable compound; and (E) a photopolymerization initiator; wherein the cyclic phosphazene compound (A) is present in a proportion of 5 to 30 wt % based on the total weight of the composition.

Abstract: A combined metal layer and a protective film are arranged on one surface side of an insulating layer, and a combined metal layer and a protective film are arranged on the other surface side of the insulating layer. These layers are overlapped one another to be passed between a pair of laminating rollers. In this case, a temperature with which the combined metal layers are heated by the laminating rollers is adjusted to not less than 300° C. and not more than 360° C. A time period during which the combined metal layers are heated by the laminating rollers is adjusted to not less than 0.1 second and not more than 0.8 second.

Abstract: A photosensitive resin composition which is excellent in flame resistance, resolution and flexibility, and substantially free from deposition of components thereof to prevent contamination of a product. The photosensitive resin composition comprises: (A) a cyclic phosphazene compound represented by the following general formula (1): wherein at least one of the Rs is an organic group having the urethane(meth)acrylate structure represented by the following general formula (2) and n is a positive number of 2 to 5: wherein R1 is a hydrogen atom or a methyl group; (B) a carboxyl-containing linear polymer obtained by polymerizing an ethylenically unsaturated compound through addition polymerization; (C) an epoxy resin; (D) an ethylenically unsaturated group-containing polymerizable compound; and (E) a photopolymerization initiator; wherein the cyclic phosphazene compound (A) is present in a proportion of 5 to 30 wt % based on the total weight of the composition.

Abstract: A printed circuit board base sheet is manufactured by laminating an insulating resin film and a metal foil using a laminate roller. A rustproofing layer containing chromium is formed on a surface of the metal foil. The temperature of the laminate roller is set to 330 to 390° C. A time period during which the metal foil and the laminate roller are brought into contact with each other immediately before a contact time point between the insulating resin film and the metal foil is set to 0.5 to 4.0 seconds.

Abstract: The invention provides a process for producing a substrate for flexible circuit boards which comprises: providing a multilayered insulating resin layer comprising an insulating layer and an adhesive layer; and laminating a metal foil to the insulating layer of the multilayered insulating resin layer via the adhesive layer at a temperature not lower than the glass transition temperature of the insulating layer.

Abstract: A ground wiring layer and a signal wiring layer are formed on a base insulating layer. A cover insulating layer is formed on the base insulating layer with an adhesive layer therebetween to cover the ground wiring layer and the signal wiring layer except for a certain region on the ground wiring layer. An electromagnetic shield layer is formed on the certain region of the ground wiring layer and the cover insulating layer. A resin solution is applied on a release sheet and dried, so that a transfer sheet including the resin layer and the release sheet is formed. Then, the surface of the resin layer is placed on the top surface of the electromagnetic shield layer and these layers are heated and pressurized, so that the transfer sheet is laminated on the electromagnetic shield layer. Thereafter, the release sheet is removed.

Abstract: A wired circuit board having good alkali resistance as well as good flexibility. The wired circuit board comprising an insulating base layer 21, a conductor layer 22 laminated on the insulating layer 21, and an insulating cover layer 23 formed on the insulating base layer 21 to cover the conductor layer 22, wherein at least the insulating base layer 21 is formed from a resin having a repeated unit expressed by at least either the following general formula (1) or (2), and a weight-average molecular weight in the range of 0.1×105 to 1.

Abstract: The invention provides a process for producing a substrate for flexible circuit boards which comprises: providing a multilayered insulating resin layer comprising an insulating layer and an adhesive layer; and laminating a metal foil to the insulating layer of the multilayered insulating resin layer via the adhesive layer at a temperature not lower than the glass transition temperature of the insulating layer.

Abstract: A flexible printed circuit board with a reinforcing plate, which comprises: a flexible printed circuit board including i) a conductive circuit pattern layer, and ii) an insulating layer made of a plastic film; a reinforcing plate; and an adhesive layer so that the reinforcing plate is attached to the flexible printed circuit board via the adhesive layer, wherein the adhesive layer is formed from an adhesive composition containing a composite metal hydroxide represented by formula (1): M1-xQx(OH)2  (1) wherein M is at least one metal atom selected from the group consisting of Mg, Ca, Sn and Ti; Q is at least one metal atom selected from the group consisting of Mn, Fe, Co, Ni, Cu and Zn; and x is a positive number from 0.01 to 0.5.

Abstract: A flexible printed circuit board with a reinforcing plate, which comprises: a flexible printed circuit board including i) a conductive circuit pattern layer, and ii) an insulating layer made of a plastic film; a reinforcing plate; and an adhesive layer so that the reinforcing plate is attached to the flexible printed circuit board via the adhesive layer, wherein the adhesive layer is formed from an adhesive composition containing a composite metal hydroxide represented by formula (1):