Reliability and performance of non-hermetic, surface-mount quad flat packages

A number of non-hermetic package formats are currently available for high leadcount, surface mount IC packaging applications. These include Plastic Quad Flat Packs [PQFPs], thermally enhanced PQFPs-with internal heat spreaders or exposed heat slugs, and Metal QFPs (known as MQUAD packages). Each package format with its unique design features can claim certain advantages in the areas of cost, reliability, and performance. Various modelling and empirical studies have been reported comparing these package formats in terms of baseline thermal performance. A comprehensive study involving thermal, electrical, and reliability performance has not heretofore been published. This paper reports the results of empirical studies performed on 160L, 28 mm EIAJ QFP package types: PQFP, PQFP with exposed heat slug, and Metal QFP. The performance of these package types is evaluated with reference to the design of each package