Cracking　of　sintered　silver　layer　always　leads　to　the　reliability　issues　in　power　devices.　In　this　paper,　the　cracking　behaviors　of　sintered　silver　layer　have　been　investigated　through　numerical　analysis　with　fracture　based　method.　Energy　release　rate　of　various　interfacial　cracks　and　vertical　cracks　in　sintered　silver　are　computed.　It　is　found　that　the　energy　release　rate　of　interfacial　crack　and　vertical　crack　are　significantly　influenced　by　their　thickness.　The　thinner　of　the　sintered　silver　layer,　the　higher　of　the　energy　release　rate　it　will　meet.　For　interfacial　crack,　the　adding　of　the　metallization　layer　does　not　improve　the　energy　release　rate　significantly.　For　vertical　crack,　two　conditions　are　considered,　i.e.,　vertical　crack　emanating　from　the　chip　sider　or　emanating　from　the　copper　baseplate　side,　and　it　is　found　that　the　energy　release　rate　is　strongly　dependent　on　its　location　and　the　existence　of　metallization　layer.　The　increase　of　the　thickness　of　Ni　layer　enables　to　lower　down　the　entire　level　of　energy　release　rate　for　vertical　crack.　Otherwise,　the　energy　release　rate　of　vertical　crack　near　the　edge　region　of　the　sintered　silver　layer　is　much　higher　than　other　locations.　It　implies　that　the　cracking　risk　is　higher　for　thinner　sintered　silver　layer　around　the　edge　region　which　should　be　avoided.　It　is　also　found　that　the　porosity　effect　on　interface　cracking　and　vertical　cracking　of　sintered　silver　is　also　important.