Surface mount plastic packages-an assessment of their thermal performance

Thermal characteristics of surface mount (SM) plastic packages such as small-outline integrated circuit (SOIC) packages, plastic leaded chip carriers (PLCCs), and fine pitch plastic leaded chip carriers (FPPLCCs) (also known as PQFP, i.e. plastic quad flat pack) used in IC packaging are described. Experimental data are reported on single-component packages in free-air, forced-air, and liquid-immersion cooling environments. Parameters of a model to help a system thermal designer to best utilize the single-component thermal data are discussed. The influence of both the package variables (such as leadframe design, chip size, and heat spreader) and user variables (such as printed-circuit-board material, package density, and cooling mode) on the thermal performance of these packages is assessed. Opportunities to enhance the thermal performance of SM plastic packages are identified and their prospects assessed.<>