Surface Mount Chip Packaging
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
The presently available surface mount plastic leaded chip carrier (PLCC) is limited in the amount of heat it can dissipate, preventing some chips from using this package. The thermal enhancement described below would increase the thermal dissipation of today's PLCC and still maintain the leaded chip carrier's high reliability. The conventional PLCC package, shown in Fig. 1, consists of a chip 10 wire bonded to a metal lead frame 11. The chip and the bonded areas of the lead frame are then totally encapsulated in plastic material 13 and the leads are bent to complete the package. The improvement to this package, shown in Fig. 2, is to bond the lead frame 20 to ceramic 21 before plastic encapsulation. The ceramic becomes an outside surface of the package, thus allowing a much better thermal path to ambient air.