Some aspects of novel micro-contacts in Microwave Chip Carriers

Design and development of novel type micro-contacts in Microwave Chip Carriers to Printed Circuit Board (PCB) assembly are presented in this paper. A new concept of micro-contacts for packaging solutions of microwave and mm-wave MMICs is depicted. Simulation and Vector Network Analyzer (VNA) measurement results for these micro-contact transitions are discussed. The results show that electrical parameters are highly dependent on the transition dimensions and substrate features. These contacts are based on male stud (bump) and female (ring) approach. When mating each other, clips effect and self-alignment features appear. Special attention is paid to the shape of the micro-contacts in order to facilitate assembly and strengthen the connection. Equivalent electrical circuit is proposed for SPICE simulation of the DC contact resistance. Finally, the article discusses technological development of the proposed new micro-contact stud/ring pair by means of low cost Ultra-violet electroplating, lithography and molding (UV-LIGA) process.