A circuit board according to the present invention includes: a first layer containing a fiber base material, and fusible fluororesin with which the fiber base material is impregnated; and second layers containing non-fusible fluororesin that are arranged on the two surfaces of the first layer.

High-speed interconnects for printed circuit boards and methods for forming the high-speed interconnects are described. A high-speed interconnect may comprise a region of a conductive film having a reduced surface roughness and one or more regions that have been treated for improved bonding with an adjacent insulating layer. Regions of reduced roughness may be used to carry high data rate signals within PCBs. Regions treated for bonding may include a roughened surface, adhesion-promoting chemical treatment, and/or material deposited to improve wettability of the surface and/or adhesion to a cured insulator.

The present invention relates to a production of electro-conductive traces on the surface of polymeric articles using laser excitation for the areas to be metallised, followed by activation of the laser-treated areas with a metal salt solution, the article is later rinsed in distilled water, and the activated areas are metallised in the chemical plating bath. The aims of the invention are to produce cost-effective conductive traces of the circuits for the application in 3D moulded interconnect devices, to increase the quality of the circuit traces improving the selective metallization process. An irradiation dose and scanning parameters for the surface excitation are chosen experimentally, provided that a negative static charge appears on the surface of the laser-irradiated areas. The chosen parameters ensure that any surface degradation of the polymer is avoided. The activation solution used in the method is aqueous solution consisting of one chosen salt comprising: silver (Ag), copper (Cu), nickel (Ni), cobalt (Co), zinc (Zn), chrome (Cr), tin (Sn) salt.

A method for manufacturing a flexible printed circuit board in which base sheets composed of Teflon film having heat resistance and low dielectric constant are stacked to prevent loss of a high frequency signal while minimizing dielectric loss due to the high frequency signal and a flexible printed circuit board manufactured by the same are disclosed. The proposed method for manufacturing a flexible printed circuit board comprises a step of preparing a base sheet which is a Teflon film having a thin film pattern formed on one surface thereof, a step of preparing an adhesive sheet, a step of stacking a plurality of base sheets and adhesive sheets, and a step of heating, pressing, and adhering a stacked body in which the plurality of base sheets and adhesive sheets are stacked.

A method for manufacturing a flexible printed circuit board in which base sheets composed of Teflon film having heat resistance and low dielectric constant are stacked to prevent loss of a high frequency signal while minimizing dielectric loss due to the high frequency signal and a flexible printed circuit board manufactured by the same are disclosed. The proposed method for manufacturing a flexible printed circuit board comprises a step of preparing a base sheet which is a Teflon film having a thin film pattern formed on one surface thereof, a step of preparing an adhesive sheet, a step of stacking a plurality of base sheets and adhesive sheets, and a step of heating, pressing, and adhering a stacked body in which the plurality of base sheets and adhesive sheets are stacked.

A circuit board according to the present invention includes: a first layer containing a fiber base material, and fusible fluororesin with which the fiber base material is impregnated; and second layers containing non-fusible fluororesin that are arranged on the two surfaces of the first layer.

Provided is a method for manufacturing a substrate for flexible printed wiring board, comprising a laminated body forming step and an integration step, wherein in the laminated body forming step, on an upper surface and a lower surface of a fluororesin layer having a modified surface, a first and second reinforcing resin layers having a coefficient of thermal expansion smaller than that of the fluororesin layer are respectively stacked through a first thermosetting adhesive, on the first reinforcing resin layer and/or the second reinforcing resin layer, a conductor layer is stacked through a second thermosetting adhesive, to form a laminated body, and in the integration step, the laminated body is heated and integrated at a temperature not lower than a curing temperature of the first and second thermosetting adhesives and lower than a melting point of the fluororesin layer.

A curable composition to be cured to provide a cured product excellent in heat resistance and dielectric properties, a cured product of the curable composition, a printed wiring board, a semiconductor sealing material, and a build-up film using the curable composition. There is provided a curable composition containing an aromatic ester resin (A) and a maleimide compound (B), the aromatic ester resin (A) being an active ester resin that is a reaction product of a first aromatic compound having two or more phenolic hydroxy groups, a second aromatic compound having a phenolic hydroxy group, and a third aromatic compound having two or more carboxy groups and/or an acid halide thereof or an esterified compound thereof, in which at least one of the first aromatic compound, the second aromatic compound, and the third aromatic compound and/or the acid halide thereof or the esterified compound thereof has a polymerizable unsaturated bond-containing substituent.

To provide a dielectric film which is excellent in dielectric properties and stability in the electric corrosion test and which is suitable for producing a high-precision printed board.

A roll film comprising a melt-processable fluororesin as the main component and having a thickness of from 1 to 100 m, the dimensional change rate of which is less than 1.0%, in terms of an absolute value, in each of MD and TD, when heated at 150 C. for 30 minutes and then cooled to 25 C., based on the dimension at 25 C.

A film having a dielectric dissipation factor at a frequency of 1 kHz and 160 C. of 0.02% or lower and a dielectric breakdown strength at 160 C. of 400 V/m or higher. Also disclosed is a film including at least one fluoropolymer selected from a tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer and a tetrafluoroethylene/hexafluoropropylene copolymer, the fluoropolymer having a crystallinity of 65% or higher.