Residual-mechanical behavior of thermomechanically fatigued Sn-Ag based solder joints

Thermomechanical fatigue (TMF) due to the mismatch in coefficients of thermal expansion between solder and substrate gradually degrades the mechanical properties of electronic solder joints during service. This study investigated the role of TMF on the residual-mechanical behavior of solder joints made with eutectic Sn-Ag solder and Sn-Ag solder with Cu or Ni additions. The TMF tests were carried out between −15°C and +150°C with a ramp rate of 25°C/min for the heating segment and 7°C/min for the cooling segment. The hold times were 20 min at the high extreme and 300 min at the low extreme. Residual shear strength was found to drop significantly during the first 250 TMF cycles, although it did remain relatively constant between 250 and 1000 cycles. Alloying elements were found to affect the residual creep strength of solder joints after TMF.

[1]  Fu Guo,et al.  Creep properties of eutectic Sn-3.5Ag solder joints reinforced with mechanically incorporated Ni particles , 2001 .

[2]  Guna S Selvaduray,et al.  Solder joint fatigue models: review and applicability to chip scale packages , 2000 .

[3]  Sungho Jin,et al.  New, lead-free solders , 1994 .

[4]  Edward Chan-Jiun Jih,et al.  Thermomechanical and Fatigue Behavior of High-Temperature Lead and Lead-Free Solder Joints , 1994 .

[5]  K. N. Subramanian,et al.  Thermomechanical fatigue behavior of Sn-Ag solder joints , 2000 .

[6]  K. N. Subramanian,et al.  Microstructural characterization of damage in thermomechanically fatigued Sn-Ag based solder joints , 2002 .

[7]  D. Hasselman,et al.  Unified Theory of Thermal Shock Fracture Initiation and Crack Propagation in Brittle Ceramics , 1969 .

[8]  Scott A. Schroeder,et al.  Fatigue of Electronic Materials , 1994 .

[9]  Z. P. Wang,et al.  Microstructure and intermetallic growth effects on shear and fatigue strength of solder joints subjected to thermal cycling aging , 2001 .

[10]  Y. C. Chan,et al.  Residual shear strength of Sn-Ag and Sn-Bi lead-free SMT joints after thermal shock , 2000 .

[11]  M. Otsuka,et al.  Effect of bismuth on the isothermal fatigue properties of Sn-3.5mass%Ag solder alloy , 1998 .

[12]  L. Luo,et al.  Effects of static thermal aging and thermal cycling on the microstructure and shear strength of Sn_95.5Ag_3.8Cu_0.7 solder joints , 2001 .

[13]  I. Anderson,et al.  A viable tin-lead solder substitute: Sn-Ag-Cu , 1994 .

[14]  K. N. Subramanian,et al.  Microstructural engineering of solders , 1999 .

[15]  K. Banerji,et al.  Constitutive relations for tin-based-solder joints , 1992, 1992 Proceedings 42nd Electronic Components & Technology Conference.

[16]  S. Jin,et al.  The design and properties of new, Pb-free solder alloys , 1994, Proceedings of 16th IEEE/CPMT International Electronic Manufacturing Technology Symposium.

[17]  M. Otsuka,et al.  Effect of thermal cycles on the mechanical strength of quad flat pack leads/Sn-3.5Ag-X (X=Bi and Cu) solder joints , 1999 .

[18]  K. N. Subramanian,et al.  Characterization of the growth of intermetallic interfacial layers of Sn-Ag and Sn-Pb eutectic solders and their composite solders on Cu substrate during isothermal long-term aging , 1999 .

[19]  Abhijit Dasgupta,et al.  Micro-Mechanics of Fatigue Damage in Pb-Sn Solder Due to Vibration and Thermal Cycling , 2001 .