Abstract: A thin film board according to the present invention has a structure in which a land, which is a connection portion with a transmission line of a printed circuit board, is used as a back wiring and extends from the end to the inside of the thin film board, and the back wiring and the front wiring are connected by a through hole. In the structure of this thin film board, the land does not become a stub and does not affect the high frequency characteristics of the circuit element. That is, there is no trade-off between the connectivity between the printed circuit board and the thin film board and the high frequency characteristics of the circuit element. Therefore, the thin film board and the circuit element in which the thin film board is mounted on the printed circuit board can support high frequency electric signals up to 60 GHz.

Abstract: A thin film board according to the present invention has a structure in which a land, which is a connection portion with a transmission line of a printed circuit board, is used as a back wiring and extends from the end to the inside of the thin film board, and the back wiring and the front wiring are connected by a through hole. In the structure of this thin film board, the land does not become a stub and does not affect the high frequency characteristics of the circuit element. That is, there is no trade-off between the connectivity between the printed circuit board and the thin film board and the high frequency characteristics of the circuit element. Therefore, the thin film board and the circuit element in which the thin film board is mounted on the printed circuit board can support high frequency electric signals up to 60 GHz.