US 10,485,102 B2
Substrate for high-frequency printed wiring board
Shingo Kaimori, Osaka (JP); Masaaki Yamauchi, Osaka (JP); Kentaro Okamoto, Osaka (JP); Satoshi Kiya, Koka (JP); and Kazuo Murata, Koka (JP)
Assigned to Sumitomo Electric Industries, Ltd., Osaka-shi, Osaka (JP); and SUMITOMO ELECTRIC PRINTED CIRCUITS, INC., Koka-shi, Shiga (JP)
Appl. No. 16/336,211
Filed by Sumitomo Electric Industries, Ltd., Osaka-shi, Osaka (JP); and SUMITOMO ELECTRIC PRINTED CIRCUITS, INC., Koka-shi, Shiga (JP)
PCT Filed Jun. 20, 2018, PCT No. PCT/JP2018/023409
§ 371(c)(1), (2) Date Mar. 25, 2019,
PCT Pub. No. WO2019/031071, PCT Pub. Date Feb. 14, 2019.
Claims priority of application No. 2017-153721 (JP), filed on Aug. 8, 2017.
Prior Publication US 2019/0215957 A1, Jul. 11, 2019
Int. Cl. H05K 1/03 (2006.01); H05K 1/09 (2006.01); H05K 1/02 (2006.01); H05K 3/00 (2006.01); H05K 3/38 (2006.01)
CPC H05K 1/0373 (2013.01) [H05K 1/0271 (2013.01); H05K 1/09 (2013.01); H05K 3/0055 (2013.01); H05K 3/381 (2013.01); H05K 2201/015 (2013.01); H05K 2201/0209 (2013.01); H05K 2201/029 (2013.01); H05K 2201/0269 (2013.01); H05K 2201/068 (2013.01); H05K 2203/1194 (2013.01)] 8 Claims
OG exemplary drawing
 
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 μm,
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.