Abstract: A polyimide is formed by dehydrating a polyamic acid. The polyamic acid is formed by polymerizing a diamine and a fluorine dianhydride. The diamine is 2,2?-bis[4-(4-aminophenoxy) phenyl] propane, and the fluorine dianhydride is 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride. When a color of the polyimide is defined by Lab color space, b component is set from about ?10 to about +10. The disclosure further relates to a copper-clad laminate, a flexible printed circuit, and a method for manufacturing the flexible printed circuit.

Abstract: A printed circuit board includes a transparent base layer, a conductive trace layer, and a transparent cover layer. The conductive trace layer is formed on a first surface of the base layer, and includes two conductive pads and a grid-shaped conductive trace pattern. the grid-shaped conductive trace pattern includes a plurality of conductive traces, the conductive traces form a plurality of strips connected one by one, each strip includes a plurality of triangles arranged in a line, each two adjacent triangles in a same strip have a same side, each two adjacent triangles in different strips have a same side, two distal ends of each strip are connected to the two conductive pads respectively. The transparent cover layer s the grid-shaped conductive trace pattern and parts of the first surface without forming the conductive trace layer.

Abstract: A printed circuit board (PCB) with visible circuit includes a circuited substrate, a first and second release films, and a first and second optical clear adhesive (OCA) layers. The first and second release films are pressed onto and are adhered to two opposite surfaces of the circuited substrate via the first and second OCA layers respectively, and the first and second OCA layers are made of polymethyl methacrylate (PMMA).

Abstract: A printed circuit board with circuit visible includes a wiring layer, a first adhesive layer, a first dielectric layer, and a cover film, which are stacked in described order, the wiring layer comprising at least one electrical contact pad. The cover film has at least one opening corresponding to the electrical contact pad. The cover film includes a second dielectric layer and a second adhesive layer. A flow initiation temperature of the first adhesive layer is in a range from 85 degrees centigrade to 90 degrees centigrade, and a hardening temperature of the first adhesive being lower than 150 degrees centigrade.

Abstract: A method for manufacturing a resin coating on copper foil includes following steps. Firstly, two diamines of 2,2-bis[4-(4-aminophenoxy)phenyl] propane and 4,4?-oxydianiline, and two acid anhydrides of pyromellitic diandydride and oxydiphthalic anhydride are added into a polar aprotic solvent and the solvent is stirred to form a mixed solution. Secondly, the mixed solution is heated to a temperature of about 170° C.-190° C. to allow a cross-linking reaction to be completed between the two diamines and the two acid anhydrides, thereby forming a thermoplastic polyimide adhesive fluid. The thermoplastic polyimide adhesive fluid is coated on a copper foil and cured to form a thermoplastic polyimide adhesive layer on the copper foil, thereby obtaining a resin coated copper foil. This disclosure also relates to resin coated copper foil and a method for manufacturing a multi-layer circuit board.

Abstract: This disclosure relates to a printed circuit board comprising a light-pervious insulation layer, a patterned electrically conductive layer and a light-pervious overlay. The patterned electrically conductive layer includes a first black oxide layer, a copper layer and a second black oxide layer. The copper layer includes two opposite surfaces and a plurality of inner surfaces interconnecting the two opposite surfaces of the copper layer. The first black oxide layer is formed on one of the surfaces, and the second black oxide layer is formed on the other surface and the inner surfaces. The patterned electrically conductive layer is arranged on the light-pervious insulation layer. The light-pervious overlay is arranged on the second black oxide layer. A method for manufacturing the printed circuit board is also provided in this disclosure.

Abstract: A method for manufacturing a resin coating on copper foil includes following steps. Firstly, two diamines of 2,2-bis[4-(4-aminophenoxy)phenyl]propane and 4,4?-oxydianiline, and two acid anhydrides of pyromellitic diandydride and oxydiphthalic anhydride are added into a polar aprotic solvent and the solvent is stirred to form a mixed solution. Secondly, the mixed solution is heated to a temperature of about 170° C.-190° C. to allow a cross-linking reaction to be completed between the two diamines and the two acid anhydrides, thereby forming a thermoplastic polyimide adhesive fluid. The thermoplastic polyimide adhesive fluid is coated on a copper foil and cured to form a thermoplastic polyimide adhesive layer on the copper foil, thereby obtaining a resin coated copper foil. This disclosure also relates to resin coated copper foil and a method for manufacturing a multi-layer circuit board.