This　paper　presents　a　grain　level　finite　element　model　to　simulate　the　cracking　behavior　of　the　intermetallic　compound　(IMC)　layer　in　solder　joints.　The　grain　microstructure　of　the　IMC　layer　is　explicitly　included　in　the　model　by　Voronoi　tessellations.　Cohesive　interface　elements　with　a　coupled　cohesive　law　are　embedded　along　the　grain　boundaries　to　simulate　microcrack　initiation,　propagation　and　coalescence　in　the　IMC　layer.　A　model　with　a　Weibull　distributed　grain　interfacial　strength　is　adopted　to　account　for　randomly　distributed　grain　boundary　defects.　The　average　thickness　of　the　IMC　layer　and　the　wavelength　and　the　roughness　of　the　waved　solder/IMC　interface　are　used　to　characterize　the　IMC　microstructure.　Using　the　numerical　approach　developed,　the　effects　of　the　grain　shape,　the　randomly　distributed　grain　boundary　defects,　the　thickness　of　the　IMC　layer　and　the　morphology　of　the　solder/IMC　interface　on　the　microcrack　patterns　and　on　the　overall　response　of　solder　joints　are　investigated.　The　results　indicate　that　the　overall　mechanical　strength　is　not　sensitive　to　the　grain　shape,　but　the　microcrack　pattern　and　the　crack　path　depend　heavily　on　the　grain　shape.　In　the　model　containing　randomly　distributed　grain　boundary　defects,　the　weak　grain　interface　plays　a　critical　role　in　the　overall　strength　and　the　crack　path　of　the　model.　The　average　thickness　of　the　IMC　layer　has　the　greatest　impact　on　the　overall　strength　and　the　failure　mode　of　the　solder　joint.　The　wavelength　and　the　roughness　of　the　solder/IMC　interface　have　little　impact　on　the　overall　strength　but　do　have　an　impact　on　the　failure　mode　of　the　solder　joint.　The　predicted　failure　mode　agrees　well　with　the　experimental　observation　in　solder　joints.　The　presented　approach　is　feasible　for　simulating　microcracking　and　the　failure　behavior　of　the　IMC　layer　in　solder　joints　and　other　quasi-brittle　polycrystalline　materials.　(C)　2013　Elsevier　B.V.　All　rights　reserved.