摘要 |
The surface acoustic wave elements and the other surface mounting elements are mounted on a ceramic multi-layer substrate 40, wherein the surface acoustic wave elements are flip chips 30 which are face-down-bonded to the gold coated mounting electrodes 43 of the multi-layer ceramic substrate 40 by way of gold-to-gold bonding, and at least the surface acoustic wave elements are covered as sealed airtight with the side walls 60 fixed to the multi-layer ceramic substrate 40 and a cover 61 closing the opening of the side walls. <IMAGE> |