US Patent No. 10,485,102


Patent No. 10,485,102
Issue Date November 19, 2019
Title Substrate For High-frequency Printed Wiring Board
Inventorship Shingo Kaimori, Osaka (JP)
Masaaki Yamauchi, Osaka (JP)
Kentaro Okamoto, Osaka (JP)
Satoshi Kiya, Koka (JP)
Kazuo Murata, Koka (JP)
Assignee Sumitomo Electric Industries, Ltd., Osaka-shi, Osaka (JP) SUMITOMO ELECTRI...

Claim of US Patent No. 10,485,102

1. A substrate for a high-frequency printed wiring board, the substrate comprising:a dielectric layer including a fluororesin and an inorganic filler; and
a copper foil layered on at least one surface of the dielectric layer, wherein
a surface of the copper foil at the dielectric layer side has a maximum height roughness (Rz) of less than or equal to 2 ?m,
a ratio of the number of inorganic atoms of the inorganic filler to the number of fluorine atoms of the fluororesin in a superficial region of the dielectric layer at the copper foil side is less than or equal to 0.08, and
a softening temperature of the fluororesin is more than or equal to 250° C. and less than or equal to 310° C.