Measurement of High-Bandwidth and High-Density Silicone Rubber Socket up to 110GHz

In this paper, electrical performances of a silicone rubber socket are experimentally verified using several measurement set-ups. Silicone rubber socket is a promising test socket that can be adopted in high-speed testing environments in place of pogo type sockets, due to it relatively shorter length and lower inductance. However, the electrical performance of silicone rubber socket is dependent on an external force because its substrate is an elastic polymer. Accordingly, the compression effect causes reliability problems of testing environments, which needs to be thoroughly evaluated to ensure reliability. In this paper, two measurement set-ups for evaluating the performance of silicone rubber sockets are introduced and compared. Firstly, double-sided measurement set-up is introduced. However, it is unsuitable for high-speed testing environments due to the coupling effects between the closely placed microwave probes. For this reason, this paper introduces another measurement set-up which uses an additional printed circuit board (PCB). The second measurement set-up evaluates the electrical performance of the silicone rubber socket by comparing the performances of the PCB only and the PCB with the silicone rubber socket. While the measured electrical performance of the second set-up is much worse because of the parasitic elements of the PCB, use of an additional PCB is more reliable than the double-sided measurement result. Using this configuration, the electrical performance of the silicone rubber socket is evaluated up to 110GHz.