Growth Kinetics Of Intermetallic Compound Layers Research Articles

Effect of Power Cycling and Heat Aging on Reliability and IMC Growth of Sn‐5Sb and Sn‐10Sb Solder Joints

Power cycle reliability of solder joints with Sn‐5Sb (mass%) and Sn‐10Sb (mass%) alloys was investigated. The effects of power cycling and heat aging on the growth of intermetallic compound (IMC) layers at the interfaces between Sn‐Sb alloys and Cu plates were also investigated. In the power cycling test, the solder joint with Sn‐10Sb has high reliability compared with that of Sn‐5Sb. IMC layers grew in both joints with increasing number of power cycles. Compared with Sn‐5Sb and Sn‐10Sb, difference in growth kinetics of IMC layers was negligible. A similar tendency was observed in the heat aging test. Compared with the power cycling and the heat aging, growth of IMC layers at the aging temperature of 200°C is faster than that in the power cycling test at the temperature range of 100°C to 200°C, while that at the aging temperature of 100°C, the growth is slower. On the basis of the comparison between the power cycling and the heat aging, it was clarified that growth kinetics of IMC layers in the power cycling can be predicted by investigating growth kinetics of the IMC layer at the temperatures in the vicinity of the peak temperature in power cycling.

The growth behaviours of IMC layers in solid‐liquid interfacial reactions of Sn1.5Cu/Cu in high magnetic fields

PurposeThe aim of this paper is to investigate the growth behaviours of intermetallic compound (IMC) layers in solid‐liquid interfacial reactions of Sn1.5Cu/Cu in various intensities of high‐magnetic field.Design/methodology/approachSn1.5Cu solder was prepared and melted in a vacuum furnace at 873 K and cast into solder bars. Samples were mounted using resin and etched after being carefully polished. Then the IMC layers were observed by using scanning electron microscopy.FindingsThe results show that the growth of IMC layers has been accelerated by high‐magnetic field through the comparison of growth kinetics of IMC layers among 0‐2.5 T magnetic filed. IMC grains in high‐magnetic field are much bigger than that in 0 T. By the analyzing of X‐ray diffractometer patterns of IMC layers, it can be found that the orientations of IMC have been changed by magnetic field.Originality/valueThis paper investigates the growth behaviour of IMC layers during the solid‐liquid interfacial reactions of Sn1.5Cu/Cu in a high magnetic field.

Interfacial evolution behavior and reliability evaluation of CoSb 3/Ti/Mo–Cu thermoelectric joints during accelerated thermal aging

Interfacial structure plays a critical role for the reliability of thermoelectric (TE) device. This study investigated the interfacial evolution behavior and the reliability of CoSb 3/Ti/Mo–Cu TE joints during accelerated thermal aging. After thermal aging, three-layer intermetallic compound (IMC) structure was observed at the CoSb 3/Ti interface, and EDS analysis confirmed that the IMC layers were composed of TiCoSb, TiSb 2 and TiSb. The total thickness of IMC layers increased linearly with the square root of aging time. The growth kinetics of IMC layers was studied. The theoretic life of CoSb 3/Ti/Mo–Cu TE device was predicted using the growth rate of IMC layers. The shear strength of aged CoSb 3/Ti/Mo–Cu TE joints was also investigated and the results showed the joints had sufficient strength after aging at 575 °C for 720 h. SEM showed that, in all the aged samples, the fracture occurred inside of the IMC layers, while the fracture occurred in the Ti layer or Ti/TiSb interface in the un-aged samples.