Thermal modeling and analysis of pin grid arrays and multichip modules

The thermal analysis of a ceramic pin grid array and multichip module was performed. A finite element computer program was used to build the thermal model. The effects that the air flow, the thermal conductivity of the substrate material, the substrate thickness, the thermal conductivity of the die attach material, and the die attach thickness have on internal and external resistances of pin grid arrays are addressed, covering the factors that control the internal and external resistances of the package. In the case of multichip modules the effects of these parameters on the maximum junction temperature rise and maximum case temperature rise have been studied. Experimental results for a ceramic pin grid array are presented. A set of charts can be used for quickly designing the package, and for choosing assembly materials and the environment for the most optimum thermal management.<>