The Effect of Nano-Cu Particles on Mechanical Properties of Micro-Joining Joint with Lead-Free Solder

2011 ◽  
Vol 291-294 ◽  
pp. 929-933
Author(s):  
Ying Ming Shen ◽  
Fang Juan Qi ◽  
Min Xie ◽  
Jian Li

The effect of nano-Cu particles on mechanical bend reliability of micro-joining joint with Sn-3.5Ag lead free solder was studied in this paper. The results show that 0.5% nano-Cu composite lead free solder show significantly better shearing strength and mechanical bend fatigue properties than eutectic Sn-3.5Ag solder paste, 1.0% nano-Cu composites and 1.5% nano-Cu composites. The further analysis shows that adding nano-Cu particles make much effect on intermetallic (IMC) in the interface of micro-joint and the inside of the solder joint. The different interface of micro-joining joint induced different mechanical properties.

2018 ◽  
Vol 30 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Fakhrozi Che Ani ◽  
Azman Jalar ◽  
Abdullah Aziz Saad ◽  
Chu Yee Khor ◽  
Roslina Ismail ◽  
...  

Purpose This paper aims to investigate the characteristics of ultra-fine lead-free solder joints reinforced with TiO2 nanoparticles in an electronic assembly. Design/methodology/approach This study focused on the microstructure and quality of solder joints. Various percentages of TiO2 nanoparticles were mixed with a lead-free Sn-3.5Ag-0.7Cu solder paste. This new form of nano-reinforced lead-free solder paste was used to assemble a miniature package consisting of an ultra-fine capacitor on a printed circuit board by means of a reflow soldering process. The microstructure and the fillet height were investigated using a focused ion beam, a high-resolution transmission electron microscope system equipped with an energy dispersive X-ray spectrometer (EDS), and a field emission scanning electron microscope coupled with an EDS and X-ray diffraction machine. Findings The experimental results revealed that the intermetallic compound with the lowest thickness was produced by the nano-reinforced solder with a TiO2 content of 0.05 Wt.%. Increasing the TiO2 content to 0.15 Wt.% led to an improvement in the fillet height. The characteristics of the solder joint fulfilled the reliability requirements of the IPC standards. Practical implications This study provides engineers with a profound understanding of the characteristics of ultra-fine nano-reinforced solder joint packages in the microelectronics industry. Originality/value The findings are expected to provide proper guidelines and references with regard to the manufacture of miniaturized electronic packages. This study also explored the effects of TiO2 on the microstructure and the fillet height of ultra-fine capacitors.


2009 ◽  
Vol 131 (1) ◽  
Author(s):  
Mohd F. Abdulhamid ◽  
Cemal Basaran

Thermomigration experiments were conducted to study the change in mechanical properties of 95.5Sn–4Ag–0.5Cu (SAC405) lead-free solder joint under high temperature gradients. This paper presents some observations on samples that were subjected to 1000°C/cm thermal gradient (TG) for 286 h, 712 h, and 1156 h. It was observed that samples subjected to thermal gradient did not develop a Cu3Sn intermetallic compound (IMC) layer, and we observed disintegration of Cu6Sn5 IMC. On the other hand, samples subjected to isothermal annealing exhibited IMC growth. In samples subjected to thermomigration, near the cold side the Cu concentration is significantly higher compared with hot side. Extensive surface hardness testing showed an increase in hardness from the hot to cold sides, which possibly indicates that Sn grain coarsening is in the same direction.


2019 ◽  
Vol 31 (2) ◽  
pp. 109-124 ◽  
Author(s):  
Fakhrozi Che Ani ◽  
Azman Jalar ◽  
Abdullah Aziz Saad ◽  
Chu Yee Khor ◽  
Mohamad Aizat Abas ◽  
...  

Purpose This study aims to investigate the NiO nano-reinforced solder joint characteristics of ultra-fine electronic package. Design/methodology/approach Lead-free Sn-Ag-Cu (SAC) solder paste was mixed with various percentages of NiO nanoparticles to prepare the new form of nano-reinforced solder paste. The solder paste was applied to assemble the ultra-fine capacitor using the reflow soldering process. A focussed ion beam, high resolution transmission electron microscopy system equipped with energy dispersive X-ray spectroscopy (EDS) was used in this study. In addition, X-ray inspection system, field emission scanning electron microscopy coupled with EDS, X-ray photoelectron spectroscopy (XPS) and nanoindenter were used to analyse the solder void, microstructure, hardness and fillet height of the solder joint. Findings The experimental results revealed that the highest fillet height was obtained with the content of 0.01 Wt.% of nano-reinforced NiO, which fulfilled the reliability requirements of the international IPC standard. However, the presence of the NiO in the lead-free solder paste only slightly influenced the changes of the intermetallic layer with the increment of weighted percentage. Moreover, the simulation method was applied to observe the distribution of NiO nanoparticles in the solder joint. Originality/value The findings are expected to provide a profound understanding of nano-reinforced solder joint’s characteristics of the ultra-fine package.


2013 ◽  
Vol 592-593 ◽  
pp. 453-456 ◽  
Author(s):  
Alexandr Otáhal ◽  
Martin Adamek ◽  
Vojtech Jansa ◽  
Ivan Szendiuch

Reliability and life-time of electric/electronic products is still a highly actual and discussed topic. Every electric/electronic product is heterogeneous system which consists not only from components and constructional parts, but also from many interconnections. Basic segments of interconnection are solder joints, recently created by lead-free materials. The passing from well-proven lead solders to lead free compositions brought many new aspects in reliability and life-time of electronic systems. Some of the negative factors are their poor electro-mechanical properties, which are based on complicated microstructure of interlayer interface. This fact causes defects in solder joints and consequential failure of the function. This article is focused on an investigation of mechanical properties of lead-free solder joints. There are investigated various properties of common lead-free solder paste depending on various concentrations of O2 by reflow process and on various components size. Next, there are shown microstructures by micro sections for various concentrations of O2. Mechanical properties (mechanical strength) are tested by shear test equipment DAGE 2400.


Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1348
Author(s):  
Tatsuya Kobayashi ◽  
Ikuo Shohji

Sn-Sb-Ni solder alloy is expected to be used as a die-attach material for a next-generation power semiconductors in power module. The aim of this paper is to investigate the effects of the Ni content on microstructures, tensile, and fatigue properties of Sn-10Sb-xNi (x = 0.05, 0.10, 0.25, 0.50) (mass%) lead-free solder alloys using miniature size specimens. The Sn-10Sb-Ni solder alloys have the microstructure in which Sb-Sn and Ni-Sb compounds are dispersed in the β-Sn matrix. As the Sb and Ni content increases, Sb-Sn and Ni-Sb compounds are coarsened, respectively. The effect of the Ni content on tensile properties of the alloy is slight at 25 °C. At 150 °C and 200 °C, 0.1% proof stress and tensile strength increase gradually with the Ni content increases, and saturate at the Ni amount over 0.25 mass%. According to the fatigue test at 200 °C, the fatigue properties of Sn-10Sb-Ni with 0.10–0.25 mass% Ni are better than that of the Sn-10Sb. From the experimental results, Sn-10Sb-Ni with 0.10–0.25 mass% Ni have superior mechanical properties.


Author(s):  
Sami T. Nurmi ◽  
Janne J. Sundelin ◽  
Eero O. Ristolainen ◽  
Toivo K. Lepisto¨

As environmental issues are raising more interest and are becoming crucial factors in all parts of the world, more and more environmental-friendly electronics products are emerging. Usually this means the introduction of products with lead-free solders. However, the reliability of lead-free solders is still a serious concern despite the vast research done in this field. This paper will describe the interconnect reliability of three kinds of solder joints respectively prepared with lead-free solder paste and lead-free PBGA components, lead-free solder paste and tin-lead-silver PBGA components, and tin-lead solder paste and tin-lead-silver PBGA components. Lead-free and tin-lead solders were composed of eutectic tin-silver-copper and tin-lead, respectively. In addition, the study also presents the effect of multiple reflow times. The study focuses on the microstructures of different assemblies. The particular interest is on the assemblies soldered with lead-free solder paste and tin-lead-silver PBGA components, since the SnPbAg solder on the bumps of the PBGA components were exposed to the reflow profile meant for the lead-free SnAgCu solder. Thus, these SnPbAg solder bumps were in the molten state almost twice as long as the rest of the solders. This had a notable effect on the reliability of these solder joints as we will be showing later in this paper. The test boards were temperature-cycled for 2500 cycles between −40 and +125°C (a 30-minute cycle). PBGA solder joint failures were monitored with a real time monitoring system. Optical and scanning electron microscopy was used to inspect the broken solder joints and their microstructure. The results of tests indicate that the number of reflow times can significantly affect the lifetime of PBGA solder joints. The most notable changes can be seen in the solder joints made with tin-lead-silver PBGA components and tin-silver-copper solder paste soldered with a lead-free reflow profile. The general trend was that the reliability of the solder joints increased in proportion to the number of reflow times. Mainly two factors are believed to have the major effect on the reliability of PBGA solder joints, voids, and microstructural changes in solder.


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