| 摘要 |
A branching filter capable of being reduced in size, particularly height, is provided. The branching filter has a configuration in which a transmitting filter chip and a receiving filter chip include a first piezoelectric substrate (1) and a second piezoelectric substrate (3), respectively, and are spaced from each other; the transmitting filter chip includes a first insulating layer (9) which extends over an IDT (2) or which is disposed above the IDT (2); the receiving filter chip includes a first insulating layer (10) which extends over an IDT (4) or which is disposed above the IDT (4); the upper surfaces of the transmitting and receiving filter chips are covered with a second insulating layer (14); external terminals (22) arranged on the upper surface of a third insulating layer (20) are electrically connected to the IDTs (2) and (4) through conductors (15, 16) extending through the first insulating layers (9, 10) and the second insulating layer (14); and the conductors (15, 16) include plating films. |
