Effects of package type, die size, material and interconnection on the junction-to-case thermal resistance of power MOSFET packages

摘要

In this paper, RthJC (junction-to-case thermal resistance) of power device packages including TO (Transistor Outline), DPAK and DFN (Dual Flat Non-Leaded) with sizes from 15 × 10mm to as small as 3×3mm is studied. First, RthJC is measured experimentally under natural convection environment. Second, a simulation model is built and verified with the experimental results. Using the validated modeling approach, RthJC is simulated for packages with different types, die sizes, materials and interconnections. The simulation results indicate that the most noticeable influence on RthJC is the die attach material for packages with bottom exposed die paddles such as DFN, DPAK and TO220. It is also seen that the die size effect on RthJC is significant for small packages such as DFN3×3. Mold compound affects the packages that do not have bottom exposed die paddles. Using copper plate as alternative interconnection for power packages can further reduce RthIC