Patent ID: 9497852
Filing Date: 2016-11-15
CPC Classification: H05K

Claim Text:
1. A high-frequency circuit substrate, comprising a metal conductor, a dielectric layer and a base plate: the metal conductor that is used for wiring and that has a surface not subjected to coarsening treatment or primer treatment; and a dielectric layer that is made of fluororesin only and that is brought into intimate contact directly with the metal conductor; the substrate causing a transmission loss of −3 dB/m or less at a frequency of 1 GHz, wherein the fluororesin consists of at least one selecting from the group consisting of polytetrafluoroethylene (PTFE), a tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA), and a tetrafluoroethylene-hexafluoropropylene copolymer (FEP), wherein chemical bonding between a carbon atom of the fluororesin and a metal atom of the metal conductor is formed, wherein the fluororesin is crosslinked through irradiation of ionizing radiation, and wherein the metal conductor has a surface roughness Rz measured by JIS B 0601-1994 of 2.0 μm or less.