US 12,108,528 B2
Insulating circuit board
Yoshiaki Sakaniwa, Saitama (JP); and Toyo Ohashi, Saitama (JP)
Assigned to MITSUBISHI MATERIALS CORPORATION, Tokyo (JP)
Appl. No. 17/439,565
Filed by MITSUBISHI MATERIALS CORPORATION, Tokyo (JP)
PCT Filed Mar. 26, 2020, PCT No. PCT/JP2020/013645
§ 371(c)(1), (2) Date Sep. 15, 2021,
PCT Pub. No. WO2020/196746, PCT Pub. Date Oct. 1, 2020.
Claims priority of application No. 2019-057990 (JP), filed on Mar. 26, 2019.
Prior Publication US 2022/0159829 A1, May 19, 2022
Int. Cl. H05K 1/02 (2006.01); H05K 1/03 (2006.01)
CPC H05K 1/032 (2013.01) [H05K 1/0203 (2013.01)] 3 Claims
OG exemplary drawing
 
1. An insulating circuit board comprising:
an insulating resin layer; and
a circuit layer made of metal pieces, each of which is in a circuit pattern and provided on one surface of the insulating resin layer, wherein
thickness t of each of the metal pieces constituting the circuit layer is 0.5 mm or more,
a closest distance L between the metal pieces provided in the circuit pattern is within a range of 1.0 mm or more and 1.5 mm or less,
a ratio L/t is 1.0 or less,
the insulating resin layer is made of a thermosetting resin, a void ratio B1 of a region between the metal pieces is 0.8% or less, and a ratio B2/B1 of a void ratio B2 of a region where the metal piece is disposed to the void ratio B1 of the region between the metal pieces is within a range of 0.5 or more and 1.5 or less, and
an angle θ between an end portion of each of the metal pieces and a surface of the insulating resin layer is within a range of 70° or more and 110° or less.