Through-silicon　via　(TSV)　technology　known　as　the　core　of　the　next　generation　of　3D　integration　has　drawn　more　and　more　attention.　However,　due　to　its　high　cost　and　yield　problems,　it　has　not　been　used　widely.　Nevertheless,　TSV　is　becoming　a　main　stream　interconnect　method　for　CIS　(CMOS　image　sensors)　packaging.　In　order　to　assess　the　reliability　behavior　of　typical　CMOS　image　sensor　such　as　delamination　during　CIS　packaging　and　reliability　testing,　CSP　packages　are　subjected　to　JEDEC　reliability　test　to　identify　the　failure　modes　and　failure　locations.　According　to　the　subsequent　cross-section　analysis,　delamination　occurs　between　the　bonding　attach　and　oxide　layer.　The　glass　crack　after　reliability　test　is　observed,　the　crack　propagates　from　the　interface　between　the　glass　and　cavity　wall　into　the　interior　of　the　glass.　Regarding　the　experimental　results,　a　plane　strain　finite　element　model　(FEM)　is　established　to　study　the　underlying　mechanisms　of　reliability　problems.　According　to　the　FEM　results,　the　maximum　shear　stress　in　cavity　wall　occurs　at　the　outside　interface　between　cavity　wall　and　the　glass.　The　maximum　shear　stress　in　bonding　attach　occurs　at　the　outside　interface　between　the　bonding　attach　and　oxide　layer.　Besides,　the　maximum　stress　occurs　in　the　low-temperature　phase,　which　is　correlated　well　with　the　SEM　results.　Based　on　the　FEM　analysis,　the　influence　of　geometric　parameters　such　as　the　height　and　width　of　cavity　wall,　the　thickness　of　the　backside　SMF,　the　thickness　of　silicon　are　also　investigated　to　develop　the　guidelines　for　CIS　packaging　design.