Surface acoustic wave device
AssigneeMurata Manufacturing Co., Ltd.
InventorsKoji Nakashima, Hideya Morishita
Life of this patent
Estimating the term…
Abstract
A SAW device (11) includes a SAW element (13) which is bonded onto a support substrate (12) in a face down mode through solder (19, 20), and a metal cap (21) enclosing the SAW element (13). Assuming that and .alpha..sub.1, .alpha..sub.2 and .alpha..sub.3 represent the thermal expansion coefficients of the SAW element (13), the support substrate (12) and the conductive cap (21) along the surface wave propagation direction respectively, .alpha..sub.3 .ltoreq..alpha..sub.1 when .alpha..sub.1 >.alpha..sub.2, and .alpha..sub.3 .ltoreq..alpha..sub.1 when .alpha..sub.1 <.alpha..sub.2.
Claims5
A surface acoustic wave device comprising:
- a support substrate;
- a surface acoustic wave element being soldered onto said support substrate to downwardly direct its surface wave propagation surface;
- and
- a conductive cap being soldered to said support
- substrate for enclosing said surface acoustic wave element, said surface acoustic wave element, said support substrate and said conductive cap being so formed as to satisfy .alpha..sub.3 .gtoreq..alpha..sub.1 when .alpha..sub.1 >.alpha..sub.2, or to satisfy .alpha..sub.3 .ltoreq..alpha..sub.1 when .alpha..sub.1 <.alpha..sub.2 assuming that .alpha..sub.1, .alpha..sub.2 and .alpha..sub.3 represent thermal expansion coefficients of said surface acoustic wave element, said support substrate and said conductive cap along the surface wave propagation direction respectively.
Dependencies are inferred from the claim text.