Interfacial Microstructure and Mechanical Reliability of Sn-58Bi/ENEPIG Solder Joints

The 42 wt.% Sn–58 wt.% Bi (Sn-58Bi) Ball Grid Array (BGA) solder balls were mounted to electroless nickel-electroless palladium-immersion gold (ENEPIG) pads by employing the reflow process profile. The effects of reflow cycles and aging time on the interfacial microstructure and growth behavior of intermetallic compounds, as well as the mechanical properties, were investigated. Pd-Au-Sn intermetallic compound (IMC) was formed at the Sn-58Bi/ENEPIG interface. With the increase in reflow cycles and aging time, the IMC grew gradually. After five reflow cycles, the shear strength of the Sn-58Bi/ENEPIG solder joints first decreased and then increased. After 500 h of aging duration under −40 °C, the shear strength of the Sn-58Bi/ENEPIG solder joints decreased by about 12.3%. The fracture mode transferred from ductile fracture to ductile and brittle mixed fracture owing to the fact that the fracture location transferred from the solder matrix to the IMC interface with the increase in reflow cycles and aging time.

[1]  J. Jung,et al.  Low Melting Temperature Sn-Bi Solder: Effect of Alloying and Nanoparticle Addition on the Microstructural, Thermal, Interfacial Bonding, and Mechanical Characteristics , 2021 .

[2]  Yanhong Tian,et al.  Comparative study between the Sn–Ag–Cu/ENIG and Sn–Ag–Cu/ENEPIG solder joints under extreme temperature thermal shock , 2021, Journal of Materials Science: Materials in Electronics.

[3]  O. Oloyede,et al.  Tensile, hardness and microstructural properties of Sn-Pb solder alloys , 2020 .

[4]  C. Yang,et al.  Influence of Pd(P) thickness on the Pd-free solder reaction between eutectic Sn-Ag alloy and Au/Pd(P)/Ni(P)/Cu multilayer , 2020 .

[5]  S. Jung,et al.  Effects of a phosphorous-containing Pd layer in a thin-ENEPIG surface finish on the interfacial reactions and mechanical strength of a Sn–58Bi solder joint , 2020 .

[6]  S. Jung,et al.  Effects of crystalline and amorphous Pd layers on initial interfacial reactions at Sn-3.0Ag-0.5Cu/thin-Au/Pd/Ni(P) solder joints , 2020 .

[7]  H. Nishikawa,et al.  Improvement in the mechanical properties of eutectic Sn58Bi alloy by 0.5 and 1 wt% Zn addition before and after thermal aging , 2018, Journal of Alloys and Compounds.

[8]  Cheng-En Ho,et al.  Interfacial microstructure and mechanical reliability of the Sn-Ag-Cu/Au/Pd(xP)/Ni(P) reactive system: P content effects , 2018, Surface and Coatings Technology.

[9]  Liangchi Zhang,et al.  Thermal aging effects on microstructure, elastic property and damping characteristic of a eutectic Sn–3.5Ag solder , 2018, Journal of Materials Science: Materials in Electronics.

[10]  S. Jung,et al.  Comparative study of ENEPIG and thin ENEPIG as surface finishes for SAC305 solder joints , 2018, Journal of Materials Science: Materials in Electronics.

[11]  Alan H. S. Chan,et al.  Effect of ENEPIG metallization for solid-state gold-gold diffusion bonds , 2017, Microelectron. Reliab..

[12]  Jeffrey C. Suhling,et al.  Packaging Reliability Effect of ENIG and ENEPIG Surface Finishes in Board Level Thermal Test under Long-Term Aging and Cycling , 2017, Materials.

[13]  Amauri Garcia,et al.  Effects of Solidification Thermal Parameters on Microstructure and Mechanical Properties of Sn-Bi Solder Alloys , 2017, Journal of Electronic Materials.

[14]  Chunqing Wang,et al.  TEM observation of interfacial compounds of SnAgCu/ENIG solder bump after laser soldering and subsequent hot air reflows , 2016 .

[15]  C. E. Ho,et al.  Pronounced effects of Ni(P) thickness on the interfacial reaction and high impact resistance of the solder/Au/Pd(P)/Ni(P)/Cu reactive system , 2014 .

[16]  Yang Li,et al.  Properties and interfacial microstructure of Sn–Zn–Ga solder joint with rare earth Pr addition , 2013 .

[17]  R. Shalaby.  Effect of silver and indium addition on mechanical properties and indentation creep behavior of rapidly solidified Bi–Sn based lead-free solder alloys , 2013 .

[18]  S. Xue,et al.  Wetting properties and interfacial microstructures of Sn-Zn-xGa solders on Cu substrate , 2010 .

[19]  Gao Lili,et al.  Thermal Fatigue Behavior of SnAgCu Soldered Joints in Fine Pitch Devices , 2010 .

[20]  L. Tsao,et al.  Intermetallic Reactions in Reflowed and Aged Sn-58Bi BGA Packages with Au/Ni/Cu Pads , 2008 .

[21]  Delfim Soares,et al.  The experimental study of the Bi-Sn, Bi-Zn and Bi-Sn-Zn systems , 2007 .

[22]  S. Jung,et al.  Lead-Free Electronics Packaging. Interfacial Reactions Between Sn-58 mass%Bi Eutectic Solder and (Cu, Electroless Ni-P/Cu) Substrate. , 2002 .

[23]  Jong Hyun Lee,et al.  Kinetics of intermetallic formation at Sn-37Pb/Cu interface during reflow soldering , 2002 .

[24]  C. Kao,et al.  Long-term aging study on the solid-state reaction between 58Bi42Sn solder and Ni substrate , 2000 .