Strain Rate Dependence on Nanoindentation Responses of Interfacial Intermetallic Compounds in Electronic Solder Joints with Cu and Ag Substrates

Abstract

This study evaluated mechanical behavior of the intermetallic compounds (IMCs) formed at the interfaces between potential Pb-free solders (Sn-Ag-Cu and Sn-Zn) and the wires of Cu and Ag under different loading rates. Compared to Ag based IMCs, Cu based IMCs were harder and stiffer, but less strain rate sensitive. The morphology of the indent impression was found depending on the ratio of the modulus to hardness, and the crystal structure of the IMCs.

Crystal Indentation Hardness

“…[2,[85][86][87][88][89][90]93,98,110,113,[116][117][118][119][120][121][122][136][137][138][139][140]. (b) fracture toughness [85,89,90,110,112,[141][142][143][144][145][146][147], and (c) strain-rate sensitivity [105,106,[148][149][150][151][152] of organic crystals with other classes of materials.…”

Indentation Plasticity and Fracture Studies of Organic Crystals

“…[2,[85][86][87][88][89][90]93,98,110,113,[116][117][118][119][120][121][122][136][137][138][139][140]. (b) fracture toughness [85,89,90,110,112,[141][142][143][144][145][146][147], and (c) strain-rate sensitivity [105,106,[148][149][150][151][152] [2,[85][86][87][88][89][90]93,98,…”

“…(b) fracture toughness [85,89,90,110,112,[141][142][143][144][145][146][147], and (c) strain-rate sensitivity [105,106,[148][149][150][151][152] [2,[85][86][87][88][89][90]93,98,110,113,[116][117][118][119][120][121][122][136][137][138][139][140]. (b) fracture toughness [85,89,90,110,112,[141][142][143][144]…”

An Evaluation Method for Tensile Characteristics of Cu/Sn IMCs Using Miniature Composite Solder Specimen

“…However, some researchers who conducted indentation tests using Cu/Sn IMCs reported that there were no cracks around the indentation. 6,9,10 Moreover, Deng et al 6 and Marquess et al 9 showed that pile-ups of Cu/Sn IMCs were observed around the indentation. These results suggest that both Cu 6 Sn 5 and Cu 3 Sn have plastic deformability.…”

“…[5][6][7][8][9][10] Deng et al measured Young's moduli of Cu 3 Sn and Cu 6 Sn 5 in Cu/solder joints by nanoindentation. 5 They also extracted the yield stress of the IMCs from loading-unloading curves in nanoindentation processes.…”