Yasufumi Kaneda

P3N-2 Packaging of SAW Devices with Small, Low Profile and Hermetic Performance

Cellular-phone markets are moving quite aggressively towards module integration and as a result, the miniaturization of devices has been accelerated. Especially SAW filters, which are key devices in RF parts, are demanded to realize a small size, low profile, with high reliability performance. Conventional SAW filters use a HTCC package with cavity structure and metal sealing to obtain high reliability performance. This structure restricts the miniaturization of SAW filters. In order to reduce size, HTCC without cavity structure and resin sealing are commonly used. However, this structure does not contribute to the high reliability performance. This paper describes the realization of a new miniaturized SAW filter which is a combination of HTCC without cavity structure and metal sealing by using a unique packaging technique to achieve a low profile with high reliability performance. The technique has been realized by using cluster sealing with solder. The optimization of the PKG design and sealing pressure was performed in solder sealing. In addition, by using plating in the outer coating, a high reliability performance can easily be achieved. Results of reliability testing including mechanical, electrical and moisture sensitivity will be discussed

Surface acoustic wave device having reflectors with both open and shorted electrodes

A surface acoustic wave device for implementing an attenuation characteristic outside of the pass band and the narrow band characteristics, preferably for use as a filter. The surface acoustic wave device includes a piezoelectric substrate, interdigital transducers formed on the piezoelectric substrate, and first and second reflectors disposed on the sides of the interdigital transducers. Each of the first and second reflectors includes an open electrode block with a plurality of electrically independent electrode fingers, and a short electrode block with a plurality of electrode fingers of which both ends are electrically shorted.