scholarly journals Effect of 0.05 wt.% Pr Addition on Microstructure and Shear Strength of Sn-0.3Ag-0.7Cu/Cu Solder Joint during the Thermal Aging Process

2019 ◽  
Vol 9 (17) ◽  
pp. 3590 ◽  
Author(s):  
Jie Wu ◽  
Songbai Xue ◽  
Jingwen Wang ◽  
Guoqiang Huang

The evolution of interfacial morphology and shear strengths of the joints soldered with Sn-0.3Ag-0.7Cu (SAC0307) and SAC0307-0.05Pr aged at 150 °C for different times (h; up to 840 h) were investigated. The experiments showed the electronic joint soldered with SAC0307-0.05Pr has a much higher shear strength than that soldered with SAC0307 after each period of the aging process. This contributes to the doping of Pr atoms, “vitamins in alloys”, which tend to be adsorbed on the grain surface of interfacial Cu6Sn5 IMCs, inhibiting the growth of IMCs. Theoretical analysis indicates that doping 0.05 wt.% Pr can evidently lower the growth constant of Cu6Sn5 (DCu6), while the growth constant of Cu3Sn (DCu3) decreased slightly. In addition, the electronic joint soldered with SAC0307-0.05Pr still has better ductility than that soldered with SAC0307, even after a 840-h aging process.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jianing Wang ◽  
Jieshi Chen ◽  
Zhiyuan Zhang ◽  
Peilei Zhang ◽  
Zhishui Yu ◽  
...  

Purpose The purpose of this article is the effect of doping minor Ni on the microstructure evolution of a Sn-xNi (x = 0, 0.05 and 0.1 wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as PC Ni/SC Ni) solder joint during reflow and aging treatment. Results showed that the intermetallic compounds (IMCs) of the interfacial layer of Sn-xNi/PC Ni joints were Ni3Sn4 phase, while the IMCs of Sn-xNi/SC Ni joints were NiSn4 phase. After the reflow process and thermal aging of different joints, the growth behavior of interfacial layer was different due to the different mechanism of element diffusion of the two substrates. The PC Ni substrate mainly provided Ni atoms through grain boundary diffusion. The Ni3Sn4 phase of the Sn0.05Ni/PC Ni joint was finer, and the diffusion flux of Sn and Ni elements increased, so the Ni3Sn4 layer of this joint was the thickest. The SC Ni substrate mainly provided Ni atoms through the lattice diffusion. The Sn0.1Ni/SC Ni joint increases the number of Ni atoms at the interface due to the doping of 0.1Ni (wt.%) elements, so the joint had the thickest NiSn4 layer. Design/methodology/approach The effects of doping minor Ni on the microstructure evolution of an Sn-xNi (x = 0, 0.05 and 0.1 Wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as PC Ni/SC Ni) solder joint during reflow and aging treatment was investigated in this study. Findings Results showed that the intermetallic compounds (IMCs) of the interfacial layer of Sn-xNi/PC Ni joints were Ni3Sn4 phase, while the IMCs of Sn-xNi/SC Ni joints were NiSn4 phase. After the reflow process and thermal aging of different joints, the growth behavior of the interfacial layer was different due to the different mechanisms of element diffusion of the two substrates. Originality/value In this study, the effect of doping Ni on the growth and formation mechanism of IMCs of the Sn-xNi/Ni (single-crystal) solder joints (x = 0, 0.05 and 0.1 Wt.%) was investigated.


2015 ◽  
Vol 27 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Peter K. Bernasko ◽  
Sabuj Mallik ◽  
G. Takyi

Purpose – The purpose of this paper is to study the effect of intermetallic compound (IMC) layer thickness on the shear strength of surface-mount component 1206 chip resistor solder joints. Design/methodology/approach – To evaluate the shear strength and IMC thickness of the 1206 chip resistor solder joints, the test vehicles were conventionally reflowed for 480 seconds at a peak temperature of 240°C at different isothermal ageing times of 100, 200 and 300 hours. A cross-sectional study was conducted on the reflowed and aged 1206 chip resistor solder joints. The shear strength of the solder joints aged at 100, 200 and 300 hours was measured using a shear tester (Dage-4000PXY bond tester). Findings – It was found that the growth of IMC layer thickness increases as the ageing time increases at a constant temperature of 175°C, which resulted in a reduction of solder joint strength due to its brittle nature. It was also found that the shear strength of the reflowed 1206 chip resistor solder joint was higher than the aged joints. Moreover, it was revealed that the shear strength of the 1206 resistor solder joints aged at 100, 200 and 300 hours was influenced by the ageing reaction times. The results also indicate that an increase in ageing time and temperature does not have much influence on the formation and growth of Kirkendall voids. Research limitations/implications – A proper correlation between shear strength and fracture mode is required. Practical implications – The IMC thickness can be used to predict the shear strength of the component/printed circuit board pad solder joint. Originality/value – The shear strength of the 1206 chip resistor solder joint is a function of ageing time and temperature (°C). Therefore, it is vital to consider the shear strength of the surface-mount chip component in high-temperature electronics.


2014 ◽  
Vol 2014 (1) ◽  
pp. 000092-000098 ◽  
Author(s):  
Sihai Chen ◽  
Guangyu Fan ◽  
Xue Yan ◽  
Chris LaBarbera ◽  
Lee Kresge ◽  
...  

A novel nano-Ag sintering paste C has been developed for a pressureless sintering process under air. Paste C was sintered at 250°C (C1) and 280°C (C2), respectively; C1 showed a slightly higher porosity but higher shear strength after aging at 250°C for 840 hours. Both C1 and C2 exhibited a microstructure much more stable than the control solder 92.5Pb/5Sn/2.5Ag, which suffered both IMC spalling after thermal aging and voiding. Ag migration toward the DBC to form a dense layer of AgCuNi(Au) was observed for all nano-Ag pastes that were studied, with C1 and C2 being more moderate in the migration rate. The Ag migration could be attributed to the tendency of Ag to form an alloy with Au, with abundant Ni and Cu at the DBC side, and appeared to be affected by the chemistry of nano-Ag paste. A liquid to liquid thermal shock test from −45°C to 240°C was attempted, and was considered too harsh for the die/DBC system employed in this study.


Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1295
Author(s):  
Sri Harini Rajendran ◽  
Seung Jun Hwang ◽  
Jae Pil Jung

This study investigates the shear strength and aging characteristics of Sn-3.0Ag-0.5Cu (SAC 305)/Cu joints by the addition of ZrO2 nanoparticles (NPs) having two different particle size: 5–15 nm (ZrO2A) and 70–90 nm (ZrO2B). Nanocomposite pastes were fabricated by mechanically mixing ZrO2 NPs and the solder paste. ZrO2 NPs decreased the β-Sn grain size and Ag3Sn intermetallic compound (IMC) in the matrix and reduced the Cu6Sn5 IMC thickness at the interface of lap shear SAC 305/Cu joints. The effect is pronounced for ZrO2A NPs added solder joint. The solder joints were isothermally aged at 175 °C for 24, 48, 144 and 256 h. NPs decreased the diffusion coefficient from 1.74 × 10–16 m/s to 3.83 × 10–17 m/s and 4.99 × 10–17 m/s for ZrO2A and ZrO2B NPs added SAC 305/Cu joints respectively. The shear strength of the solder joints decreased with the aging time due to an increase in the thickness of interfacial IMC and coarsening of Ag3Sn in the solder. However, higher shear strength exhibited by SAC 305-ZrO2A/Cu joints was attributed to the fine Ag3Sn IMC’s dispersed in the solder matrix. Fracture analysis of SAC 305-ZrO2A/Cu joints displayed mixed solder/IMC mode upon 256 h of aging.


2004 ◽  
Vol 126 (3) ◽  
pp. 359-366 ◽  
Author(s):  
Changqing Liu ◽  
Paul Conway ◽  
Dezhi Li ◽  
Michael Hendriksen

This research seeks to characterize the micro-mechanical behavior of Sn-Ag-Cu solder bumps/joints generated by fine pitch flip chip assembly processes. The solder bumps and joints that were aged at either 80 °C or 150 °C for up to 440 hours (∼18 days); have been studied by an analysis using micro-shear testing and nano-indentation techniques. The shear test of the aged bumps showed a slight increase in shear strength after an initial period of aging (∼50 hours) as compared to the non-aged bumps, but a decrease after longer aging (e.g. 440 hours). A brittle Ag3Sn phase formed as large stick-like features in the body of bulk solder and near the interface of solder/UBM during the initial aging, and is attributed with the increase of shear strength, along with the refinement of the bump microstructure. However, as the time of aging extended, the solder bumps were softened due to grain growth and re-crystallization. It was found that the formation of brittle phases in the body of solder and along the interfaces caused localized stress concentration, which can significantly affect joint reliability. In addition, Nano-testing identified a large lamellar Au-rich structure, formed in the solder and interface of the solder/PCB in the joints after the aging process at 150 °C. These are believed to be detrimental to joint reliability.


2011 ◽  
Vol 40 (6) ◽  
pp. 1416-1421 ◽  
Author(s):  
Limin Ma ◽  
Feng Tai ◽  
Guangchen Xu ◽  
Fu Guo ◽  
Xitao Wang

2016 ◽  
Vol 700 ◽  
pp. 113-122 ◽  
Author(s):  
Mohd Noor Ervina Efzan ◽  
Mohd Mustafa Al Bakri Abdullah

In this paper, the effect of thermal aging to the Sn-Zn and Sn-Zn-Bi solders on Cu substrate was studied. Sn-Zn was chosen and the effect of addition of Bi was investigated in this work. In this research, Sn-9Zn and Sn-6Zn-4Bi were subjected to thermal aging for 24h, 72h, 120h at 75°C and 100°C respectively. Both solder shown increased of thickness intermetallic layer with increasing time. However, Sn-9Zn recorded higher increment of intermetallic layer compared to Sn-6Zn-4Bi. The hardness of solder joint on Cu substrate was decreased for both solders with increasing aging time.


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