In　this　paper,　the　thickness　effect　of　sintered　silver　layer　was　investigated　based　on　end-notched　flexure　(ENF)　test,　and　the　sensitivity　of　shear　fracture　behavior　of　sintered　silver　joints　with　different　thickness　under　the　same　strain　rate　was　investigated.　Four　kinds　of　sintered　silver　joint　ENF　samples　with　four　kinds　of　sintered　silver　layer　thickness　were　prepared　on　two　pieces　of　bare　copper　with　50　mu　m,　100　mu　m,　150　mu　m　and　200　mu　m　thick　steel　screen　printing　silver　paste.　The　loading　rate　is　0.2　mm/min,　and　the　three-point　bending　test　is　carried　out　on　the　Instron　5948　micro　tester.　The　fracture　morphology　and　microstructure　of　the　sintered　silver　layer　after　ENF　test　are　analyzed　by　Hitachi　S4000　scanning　electron　microscope　(SEM)　and　optical　microscope　(OM).　The　compliance　based　beam　method　(CBBM)　is　used　to　fracture　analysis　of　the　specimen.　Under　certain　quasi-static　loading　conditions,　the　shear　fracture　toughness　of　sintered　silver　increases　with　the　increase　of　the　thickness　of　sintered　silver　layer,　and　the　porosity　of　sintered　silver　gradually　decreased　to　a　stable　value.