The　thermal　fatigue　reliability　of　solder　bumps　in　TSV　interposer　package　is　analyzed　by　finite　element　method.　The　3D　finite　element　model　of　TSV　interposer　package　is　established　in　ANSYS　software.　Anand　constitutive　model　is　adopted　to　describe　the　viscoplastic　behavior　of　Sn3.0Ag0.5Cu　lead-free　solder　bumps.　The　influences　of　material　properties　and　structural　geometries　on　thermal　fatigue　reliability　are　evaluated　by　Taguchi　method.　The　optimized　factor　combination　design　for　promoting　thermal　fatigue　reliability　is　obtained　and　validated　by　finite　element　analysis.　The　finite　element　modeling　results　show　that　the　critical　solder　bump　is　located　at　the　corner　of　solder　bump　array.　Both　the　maximum　von　Mises　stress　and　accumulated　nonlinear　strain　energy　density　are　located　at　the　top　layer　elements　of　the　critical　solder　bump.　It　is　found　that　the　material　properties　of　underfill　have　the　most　important　influence　on　thermal　fatigue　reliability　of　solder　bumps.　The　higher　Modulus　and　lower　CTE　improves　the　thermal　fatigue　life　greatly.　It　is　validated　by　finite　element　analysis　that　the　optimized　factor　combination　design　can　successfully　improve　the　thermal　fatigue　reliability　of　solder　bumps.　©　2013　IEEE.