Press-pack　insulated　gate　bipolar　transistors　(IGBT)　have　a　multilayer　structure,　which　is　clamped　by　pressure.　The　IGBT　chip　generates　heat　and　forms　the　temperature　gradient　in　the　multilayer　structure　during　work.　Due　to　different　coefficient　of　thermal　expansion　of　multilayer　structure,　temperature　and　clamping　force　will　lead　constant　changes　in　the　internal　stress　of　the　device,　resulting　in　interface　wear　and　roughness.　The　thermal　contact　resistance　and　the　heat　dissipation　will　be　affected.　And　then　reduce　the　reliability　of　the　device.　In　this　paper,　the　finite　element　Analysis　(FEA)　is　used　to　analyze　the　heat　transfer　in　a　three-dimension　model　of　PP　IGBT.　Based　on　the　contact　surface　of　the　chip　and　the　emitter　molybdenum　plate,　the　submodel　technology　is　used　to　investigate　the　effects　of　several　factors　on　the　thermal　contact　resistance,　including　real　contact　areas,　the　height　of　contact　joint,　and　the　position　of　the　third-level　submodel.　And　then,　the　method　of　single　factor　analysis　is　used　to　analyze　the　effect　on　thermal　contact　resistance.　The　results　show　that　the　thermal　contact　resistance　decrease　with　the　increase　of　real　contact　areas,　the　thermal　contact　resistance　increase　with　the　increase　of　the　height　of　the　contact　joint,　and　the　position　of　the　third-level　submodel　have　little　effect　on　thermal　contact　resistance.　©　2021　IEEE.