Challenges in RF and microwave system-reliability

The author presents an overview of the challenges in designing reliability into high-frequency RF and microwave systems. Data relative to the design, material properties, process-related issues, and environmental conditions have been compiled. Collective experience and published reports revealed several common problems including power and thermal dissipation, bond material, wire bonding, dielectric properties, substrate properties, packaging and mechanical integrity, and high temperature and humidity. Some reliability challenges and possible approaches are presented. The methodology utilized in this study included technology evaluation, design review, and analytical findings of development systems. Many different types of parts were analyzed, including diodes, transistors, amplifiers, oscillators, switches, delay lines, and filters. Common causes for reliability problems were identified. Suggestions and recommendations are made relative to the design at high frequencies