As　one　of　the　promising　packaging　materials,　the　paste　of　silver　nanoparticles　(AgNPs)　reinforced　by　SiC　particles　is　investigated　in　this　study　for　microstructure,　thermal　stability　and　constitutive　behaviour.　As　a　common　challenge　in　the　integrated　circuit　industry,　it　is　difficult　to　reveal　the　strain　rate-dependent　mechanical　properties　of　thin-film　materials　in　such　a　large　number　of　sandwich-like　electronic　devices.　In　this　paper,　to　enable　finite　element　analysis　for　mechanical　reliability　of　packaging　structure,　the　stress-strain　relationships　of　the　sintered　AgNP　material　at　different　strain　rates　are　evaluated　analytically　using　the　nanoindentation　approach　with　the　Berkovich　type　of　indenter.　Based　on　dimensionless　analysis,　the　work　done　and　contact　stiffness　are　identified　as　the　critical　variables　from　nanoindentation　responses.　The　proposed　rate　factors　for　the　representative　stress　and　the　hardening　exponent　attempts　to　bridge　the　strain　rate　gap　between　nanoindentation　and　uniaxial　tests.　The　proposed　rate　factors　are　calibrated　by　a　typical　lead-free　packaging　material　Sn-3.0Ag-0.5Cu　based　on　tensile　tests　under　the　uniaxial　strain　rate　between　10-4　s-　1　and　10-3　s-　1　and　nanoindentation　tests　under　the　indentation　strain　rate　between　0.01　s-1　and　0.10　s-1.　This　makes　it　possible　that　the　proposed　approach　is　capable　of　shifting　the　indentation　strain　rate　by　a　factor　of　100　with　regard　to　the　uniaxial　strain　rate.　In　this　manner,　the　constitutive　responses　of　sintered　AgNP　materials　at　different　uniaxial　strain　rates　are　achieved　and　compared　with　the　predictions　by　using　a　spherical　indenter,　which　reveals　the　advantages　of　assessing　the　strain　rate　sensitivity　of　sintered　AgNP　by　using　a　Berkovich　indenter.