Novel microcontacts in microwave chip carriers developed by UV-LIGA process

Design and development of novel type microcontacts in monolithic microwave integrated circuit (MMIC) chip-carriers to printed circuit board (PCB) assembly are presented in this paper. Several new concepts of microcontacts for packaging solutions of microwave and millimeter-wave MMIC are depicted. Simulation and vector network analyzer (VNA) measurement results for these microcontact transitions are discussed and conclusions for the optimal dimensions are made. Equivalent electrical circuits are extracted from the measured S-parameter data. The results show that the electrical parameters are highly dependent on the transition dimensions and substrate features. These contacts are based on male stud (bump) and female ring concept. When mating each other, there are clips effect and self-alignment features. Finally, the article discusses the technological implementation of the proposed new microcontact stud-ring through a low-cost ultraviolet electroplating, lithography, and molding (UV-LIGA) process.