Advanced multi-layer ceramic surface-mount functional components for telecommunications equipment

We have developed various kinds of miniatured chip-type ceramic monolithic electronic components such as chip LC filters, hybrid couplers and delay lines, using low temperature cofireable ceramics (LTCC) with copper inner electrodes. The outer electrodes are also made of copper plated by Ni and Sn. Based on such LTCC multilayering technologies, our advanced microwave circuit design technologies have recently developed a chip RF diode switch and such a switch with integrated low-pass filter in a small (6.7/spl times/5.0/spl times/3.0 mm in production, 5.4/spl times/4.0/spl times/2.8 mm under development), surface-mountable package. Those devices employ the monolithic ceramic substrate, which includes relevant passive elements in it, with copper inner electrodes and copper outer/surface electrodes plated by Ni and Au. This paper discusses related ceramic material systems, manufacturing process, circuit design technologies and operating parameters of those chip RF diode switches.