About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
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Symposium
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Phase Stability, Phase Transformations, and Reactive Phase Formation in Electronic Materials XIX
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Presentation Title |
Effects of Pd(P) Thickness on the Interfacial Reaction and Mechanical Properties of the Sn-3.5Ag/Au/Pd(P)/Ni(P) Microelectronic Joints |
Author(s) |
Cheng-Yu Lee, Wei-Ling Chou, Ming-Kai Lu, Tsai-Tung Kuo, Cheng-En Ho |
On-Site Speaker (Planned) |
Cheng-Yu Lee |
Abstract Scope |
The effects of Pd(P) thickness (δPd(P)) on the interfacial reaction between eutectic Sn-Ag (Sn-3.5Ag) solder and Au/Pd(P)/Ni(P) (ENEPIG) surface finish and on the joint mechanical reliability were investigated. The types of intermetallic compound (IMC) species grew at the joint interface strongly depended on δPd(P). A slight increase of δPd(P) from 0 μm to 0.2 μm might cause an additional (Pd,Ni)Sn4 layer formed at the interface after soldering and subsequently solid-state annealing, which significantly retarded the growths of Ni3Sn4, Ni2SnP, and Ni3P, and seriously degraded the shear strength of solder joints in high-speed ball shear (HSBS) testing. This δPd(P)-dependent interfacial microstructure was distinctly different from the Cu-containing joint system, i.e., Sn-Ag-Cu/Au/Pd(P)/Ni(P) and can be rationalized using a Pd-Ni-Sn isotherm. The above observations indicated that δPd(P) is an important factor of solderability and should be appropriately reduced to a specific thickness value in terms of ENEPIG solderability. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |