Effect of intermetallic compound layer thickness on the shear strength of 1206 chip resistor solder joint

2015 ◽  
Vol 27 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Peter K. Bernasko ◽  
Sabuj Mallik ◽  
G. Takyi
Keyword(s):  
Shear Strength ◽  
Intermetallic Compound ◽  
Solder Joint ◽  
Layer Thickness ◽  
Solder Joints ◽  
Ageing Time ◽  
Circuit Board ◽  
Intermetallic Compound Layer ◽  
Content Type ◽  
Surface Mount

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.

The formation of intermetallic layer structure of SAC405/Cu and SAC405/ENImAg solder joint interfaces

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rabiatul Adawiyah Mohamed Anuar ◽  
Saliza Azlina Osman
Keyword(s):  
Shear Strength ◽  
Surface Finish ◽  
Printed Circuit Boards ◽  
Solder Joints ◽  
Layer Structure ◽  
Ageing Time ◽  
Intermetallic Layer ◽  
Electroless Nickel ◽  
Optical Microscope ◽  
Content Type

Purpose The surface finish is an essential step in printed circuit boards design because it provides a solderable surface for electronic components. The purpose of this study to investigate the effects of different surface finishes during the soldering and ageing process. Design/methodology/approach The solder joints of Sn-4.0Ag-0.5Cu/Cu and Sn-4.0Ag-0.5Cu/electroless nickel/immersion silver (ENImAg) were investigated in terms of intermetallic (IMC) thickness, morphology and shear strength. The microstructure and compositions of solder joints are observed, and analyzed by using scanning electron microscopy (SEM-EDX) and optical microscope (OM). Findings Compounds of Cu6Sn5 and (Cu, Ni)6Sn5 IMC were formed in SAC405/Cu and SAC405/ENImAg, respectively, as-reflowed. When the sample was exposed to ageing, new layers of Cu3Sn and (Ni, Cu)3Sn5 were observed at the interface. Analogous growth in the thickness of the IMC layer and increased grains size commensurate with ageing time. The results equally revealed an increase in shear strength of SAC405/ENImAg because of the thin layer of IMC and surface finish used compared to SAC405/Cu. Hence, a ductile fracture was observed at the bulk solder. Overall, the ENImAg surface finish showed excellent performance of solder joints than that of bare Cu. Originality/value The novel surface finish (ENImAg) has been developed and optimized. This alternative lead-free surface finish solved the challenges in electroless nickel/immersion gold and reduced cost without affecting the performance.

Cracking of the Intermetallic Compound Layer in Solder Joints Under Drop Impact Loading

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Tong An ◽  
Fei Qin
Keyword(s):  
Intermetallic Compound ◽  
Solder Joint ◽  
Impact Loading ◽  
Driving Force ◽  
Solder Joints ◽  
Compound Layer ◽  
Drop Impact ◽  
Lead Free ◽  
Intermetallic Compound Layer ◽  
Crack Driving Force

The significant difference between failure modes of lead-containing and lead-free solder joints under drop impact loading remains to be not well understood. In this paper, we propose a feasible finite element approach to model the cracking behavior of solder joints under drop impact loading. In the approach, the intermetallic compound layer/solder bulk interface is modeled by the cohesive zone model, and the crack driving force in the intermetallic compound layer is evaluated by computing the energy release rate. The numerical simulation of a board level package under drop impact loading shows that, for the lead-containing Sn37Pb solder joint, the damage in the vicinity of the intermetallic compound layer initiates earlier and is much greater than that in the lead-free Sn3.5Ag solder joint. This damage relieves the stress in the intermetallic compound layer and reduces the crack driving force in it and consequently alleviates the risk of the intermetallic compound layer fracturing.

Solder joint defect classification based on ensemble learning

2017 ◽  
Vol 29 (3) ◽  
pp. 164-170 ◽  
Author(s):  
Hao Wu
Keyword(s):  
Random Forest ◽  
Solder Joint ◽  
Decision Trees ◽  
Printed Circuit Board ◽  
Solder Joints ◽  
High Accuracy ◽  
Ensemble Method ◽  
Circuit Board ◽  
Content Type

Purpose This paper aims to inspect the defects of solder joints of printed circuit board in real-time production line, simple computing and high accuracy are primary consideration factors for feature extraction and classification algorithm. Design/methodology/approach In this study, the author presents an ensemble method for the classification of solder joint defects. The new method is based on extracting the color and geometry features after solder image acquisition and using decision trees to guarantee the algorithm’s running executive efficiency. To improve algorithm accuracy, the author proposes an ensemble method of random forest which combined several trees for the classification of solder joints. Findings The proposed method has been tested using 280 samples of solder joints, including good and various defect types, for experiments. The results show that the proposed method has a high accuracy. Originality/value The author extracted the color and geometry features and used decision trees to guarantee the algorithm's running executive efficiency. To improve the algorithm accuracy, the author proposes using an ensemble method of random forest which combined several trees for the classification of solder joints. The results show that the proposed method has a high accuracy.

Property of Sn-37Pb solder bumps with different diameter during thermal shock

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guisheng Gan ◽  
Donghua Yang ◽  
Yi-ping Wu ◽  
Xin Liu ◽  
Pengfei Sun ◽  
...  
Keyword(s):  
Shear Strength ◽  
Solder Joint ◽  
Thermal Shock ◽  
Solder Joints ◽  
Test Method ◽  
Content Type ◽  
Ball Size ◽  
Solder Bumps ◽  
Free Solder ◽  
The Impact

Purpose The impact strength of solder joint under high strain rate was evaluated by board level test method. However, the impact shear test of single solder bump was more convenient and economical than the board level test method. With the miniaturization of solder joints, solder joints were more prone to failure under thermal shock and more attention has been paid to the impact reliability of solder joint. But Pb-free solder joints may be paid too much attention and Sn-Pb solder joints may be ignored. Design/methodology/approach In this study, thermal shock test between −55°C and 125°C was conducted on Sn-37Pb solder bumps in the BGA package to investigate microstructural evolution and growth mechanism of interfacial intermetallic compounds (IMCs) layer. The effects of thermal shock and ball diameter on the mechanical property and fracture behavior of Sn-37Pb solder bumps were discussed. Findings With the increase of ball size, the same change tendency of shear strength with thermal shock cycles. The shear strength of the solder bumps was the highest after reflow; with the increase of the number of thermal shocks, the shear strength of the solder bumps was decreased. But at the time of 2,000 cycles, the shear strength was increased to the initial strength. Minimum shear strength almost took place at 1,500 cycles in all solder bumps. The differences between maximum shear strength and minimum shear strength were 9.11 MPa and 16.83 MPa, 17.07 MPa and 15.59 MPa in φ0.3 mm and φ0.4 mm, φ0.5 mm and φ0.6 mm, respectively, differences were increased with increasing of ball size. With similar reflow profile, the thickness of IMC decreased as the diameter of the ball increased. The thickness of IMC was 2.42 µm and 2.17 µm, 1.63 µm and 1.77 µm with increasing of the ball size, respectively. Originality/value Pb-free solder was gradually used to replace traditional Sn-Pb solder and has been widely used in industry. Nevertheless, some products inevitably used a mixture of Sn-Pb and Pb-free solder to make the transition from Sn-Pb to Pb-free solder. Therefore, it was very important to understand the reliability of Sn-Pb solder joint and more further research works were also needed.

Effects of Sn-Ag-x leveling layers on the microstructure and mechanical properties of SnBi low-temperature solder joints

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yang Liu ◽  
Yuxiong Xue ◽  
Min Zhou ◽  
Rongxing Cao ◽  
Xianghua Zeng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Low Temperature ◽  
Solder Joint ◽  
Design Methodology ◽  
Solder Joints ◽  
Fracture Morphology ◽  
Content Type ◽  
Before And After ◽  
Mechanical Performances

Purpose The purpose of this paper is to investigate the effects of Sn-Ag-x leveling layers on the mechanical properties of SnBi solder joints. Four Sn-Ag-x (Sn-3.0Ag-0.5Cu, Sn-0.3Ag-0.7Cu, Sn-0.3Ag-0.7Cu-0.5 Bi-0.05Ni and Sn-3.0Ag-3.0 Bi-3.0In) leveling layers were coated on Cu pads to prepare SnBi/Sn-Ag-x/Cu solder joints. The microstructure, hardness, shear strength and fracture morphology of solder joints before and after aging were studied. Design/methodology/approach The interfacial brittleness of the SnBi low-temperature solder joint is a key problem affecting its reliability. The purpose of this study is to improve the mechanical properties of the SnBi solder joint. Findings Owing to the addition of the leveling layers, the grain size of the ß-Sn phase in the SnBi/Sn-Ag-x/Cu solder joint is significantly larger than that in the SnBi/Cu eutectic solder joint. Meanwhile, the hardness of the solder bulk in the SnBi/Cu solder joint shows a decrease trend because of the addition of the leveling layers. The SnBi/Cu solder joint shows obvious strength drop and interfacial brittle fracture after aging. Through the addition of the Sn-Ag-x layers, the brittle failure caused by aging is effectively suppressed. In addition, the Sn-Ag-x leveling layers improve the shear strength of the SnBi/Cu solder joint after aging. Among them, the SnBi/SACBN/Cu solder joint shows the highest shear strength. Originality/value This work suppresses the interfacial brittleness of the SnBi/Cu solder joint after isothermal aging by adding Sn-Ag-x leveling layers on the Cu pads. It provides a way to improve the mechanical performances of the SnBi solder joint.

Investigations of Interfacial Reaction and Shear Strength between Pb-Free Flip Chip Solder and Electroplated Cu UBM

2005 ◽  
Vol 297-300 ◽  
pp. 863-868
Author(s):  
Dae Gon Kim ◽  
Hyung Sun Jang ◽  
Jong Woong Kim ◽  
Seung Boo Jung
Keyword(s):  
Shear Strength ◽  
Intermetallic Compound ◽  
Layer Thickness ◽  
Flip Chip ◽  
Solder Bump ◽  
Ductile Failure ◽  
Compound Layer ◽  
Intermetallic Compound Layer ◽  
Quantitative Analyses ◽  
Dominant Phase

In the present work, we investigated the interfacial reactions and shear properties between Sn-3.0Ag-0.5Cu flip chip solder bump and Cu UBM after multiple reflows. The quantitative analyses of the intermetallic compound layer thickness as a function of the number of reflows were performed. After six reflows, the reaction product could be distinguished by two intermetallic compounds: Cu3Sn adjacent to the substrate and Cu6Sn5 which was the dominant phase. The thickness of total intermetallic compound layers increased with the number of reflows. The shear strength value did not significantly change as a function of the number of reflows. Nearly all of the test specimens showed ductile failure mode, and this could be well explained with the results of FEM analyses.

Thermal cycling effect on the drop reliability of BGA lead-free solder joints

2017 ◽  
Vol 29 (4) ◽  
pp. 199-202 ◽  
Author(s):  
Fang Liu ◽  
Jiacheng Zhou ◽  
Nu Yan
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Printed Circuit Board ◽  
Solder Joints ◽  
Drop Test ◽  
Circuit Board ◽  
Metallographic Analysis ◽  
Content Type ◽  
Bga Package ◽  
Free Solder

Purpose The purpose of this paper is to study the drop reliability of ball-grid array (BGA) solder joints affected by thermal cycling. Design/methodology/approach The drop test was made with the two kinds of chip samples with the thermal cycling or not. Then, the dyeing process was taken by these samples. Finally, through observing the metallographic analysis results, the conclusions could be found. Findings It is observed that the solder joint cracks which were only subjected to drop loads without thermal cycling appeared near the BGA package pads. The solder joint cracks which were subjected to drop loads with thermal cycling appear near the printed circuit board pads. Originality/value This paper obtains the solder joint cracks picture with drop test under the thermal cycling.

IC Component Level Failure Induced By Intermetallic Layer Structural Defects of Solder Joint

2002 ◽  
Vol 753 ◽  
Author(s):  
Ming Sun ◽  
Mike Loo ◽  
Lily Zhao
Keyword(s):  
Intermetallic Compound ◽  
Solder Joint ◽  
Intermetallic Layer ◽  
Microstructural Analysis ◽  
Joint Damage ◽  
Compound Layer ◽  
Circuit Board ◽  
Structural Defects ◽  
Intermetallic Compound Layer ◽  
Bare Copper

ABSTRACTSolder joint has been widely used in microelectronics industry as an interconnect of Integrated Circuit (IC) chip and Printed Circuit Board (PCB). Frequently, a functional failure of the component on the system is a result of solder joint damage. Eutectic 63Sn/37Pb solder joint mechanical behaviors on Ni/Au plated copper pad and bare copper pad were experimentally investigated to address the effect of pad surface cleanness on the formation of intermetallic compound. The joints with thinner intermetallic compound layer resulted in a poor solder ball shear strength. Microstructural analysis revealed that the oxidations of Ni and Cu during substrate manufacturing contributed to the improper growth of intermetallic compound during assembly and reliability tests. In additions, the experimental results showed that the growth of the intermetallic compound layer were dependent not only on the time and temperature of solder reflow and testing, but also on the cleanness of the pad surfaces and available area for the diffusion of Ni in the case of Ni/Au plated copper pad, Cu in the case of bare copper pad and Sn in the joint area.

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