MEMS Production and Yield Improvement Using a FLUX-FREE/VOID-FREE Assembly Process

摘要

Microelectromechanical systems (MEMS) promise to revolutionize nearly every product category by bringing together silicon-based microelectronics with micromachining technology, thereby, making possible the realization of a complete system-on-a-chip. As the MEMS application approaches the different market places cost, performance, hermeticity, and reliability become the key issues. Flux free/void-free soldering is accomplished by controlling the atmosphere, time, and temperature. This is a simplified version of the Pressure Variation method. P_1 V_1 = P2 V2, V2 = V_1 (P_1/ P2). The hermeticity level of the package can directly affect MEMS device performance. Hermeticity level of 10~(-8) and sometimes 10~(-9) are common measurements. Getter firing as part of the package seal process means higher yields, total control of the internal atmosphere of the package, improved quality and reliability. Getter pumps are based on those elements in the periodic table with features that make them suitable to act as a vacuum pump. Quality control standards for MEMS technologies are needed. Part of the problem is that the technology is so new and ever changing that the fabricators do not yet know how to define quality, much less measure it.