High density microelectronic packaging with thick film hermeticpackages

摘要

A high-density packaging approach has been developed that useshermetic ceramic packages made with thick-film techniques. The overallpackaging density, at the printed circuit (PC) board level, iscomparable to or better than that achieved with some multichip packagingapproaches. Low-cost thick-film ceramic packages are produced with nohard tooling from multiple sources. Chips are packaged, burned in, andtested in these packages with standard processes and production lines.The ceramic packages are then cut down to a smaller size by laserscribing and are mounted on printed circuit boards. The packages arethen interconnected to the board by automatic gold-to-gold wire bonding.The author describes practical aspects of this packaging approach withrespect to the design and fabrication of the thick-film ceramicpackages, chip packaging and test using these packages, PC board designand fabrication, and PC board assembly. The issues of procurement costs,design, fabrication cycle times, parts screening, packaging density,rework, electrical considerations, thermal performance, processmaturity, and reliability are also discussed