In　this　article,　the　correlation　between　the　thermal　contact　resistance　and　the　surface　roughness　characteristics　of　the　contact　interface　in　the　press-pack　insulated-gate　bipolar　transistor　(PP-IGBT)　modules　during　power　cycling　was　studied　by　experimental　measurements　and　finite-element　(FE)　simulation-based　factorial　design　analysis.　Thermal　transient　test　technology　was　applied　to　examine　the　change　in　the　thermal　characteristic　parameters　of　the　PP-IGBT　module.　This　shows　that　the　increase　in　the　thermal　contact　resistance　of　the　Al　metallization/emitter　Mo　contact　interface　occurs　more　dramatically　during　power　cycling.　A　3-D　surface　profilometer　was　used　to　evaluate　the　surface　morphology　parameters　of　the　Al　metallization/emitter　Mo　contact　interface.　The　equivalent　root-mean-square　(RMS)　roughness　increases　during　power　cycling,　and　the　equivalent　asperity　slope　and　the　equivalent　spacing　between　asperities　increase　slightly.　Additionally,　the　surface　roughening　in　the　corner　area　of　the　chip　is　more　obvious　than　in　other　regions.　A　fractional　factorial　design　analysis　based　on　FE　simulations　was　performed.　The　results　indicate　that　the　thermal　contact　resistance　strongly　depends　on　the　main　effects　of　the　real　contact　area　and　the　spacing　between　the　asperities,　and　the　RMS　roughness　and　the　asperity　slope　interaction.