US 12,004,290 B2
Multilayer board
Nobuyuki Tenno, Nagaokakyo (JP); Nobuo Ikemoto, Nagaokakyo (JP); and Takahiro Baba, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Oct. 29, 2021, as Appl. No. 17/514,211.
Application 17/514,211 is a continuation of application No. PCT/JP2020/023357, filed on Jun. 15, 2020.
Claims priority of application No. 2019-128610 (JP), filed on Jul. 10, 2019.
Prior Publication US 2022/0053632 A1, Feb. 17, 2022
Int. Cl. H05K 1/02 (2006.01); H01P 3/08 (2006.01)
CPC H05K 1/0237 (2013.01) [H01P 3/08 (2013.01); H05K 1/0298 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A multilayer board comprising:
a transmission line including a plurality of layers including a first insulator layer, a first joining material layer in contact with a first surface of the first insulator layer, and a second joining material layer in contact with a second surface of the first insulator layer; wherein
a signal conductor of the transmission line is provided on the first surface of the first insulator layer;
a relative permittivity of the second joining material layer is lower than a relative permittivity of the first joining material layer; and
an adhesion strength between the first insulator layer and the first joining material layer is higher than an adhesion strength between the first insulator layer and the second joining material layer.