Effects of Graphene Nanosheets on the Wettability and Mechanical Properties of Sn-0.3Ag-0.7Cu Lead-Free Solder

Thermal Fatigue Failure of Micro-Solder Joints in Electronic Packaging Devices: A Review

“…Therefore, the high-temperature stage of thermal cycling promotes the isomerization and coarsening of the solder, resulting in cracks [30], as shown in Figure 4. Cracks spread between the interfacial metal compound layer (early stage of thermal fatigue) and the coarsely crystalline zone of the solder microstructure (after multiple thermal cycles), and its thickness has almost no effect on the thermal fatigue properties of the solder [31]. In addition, residence time at high temperatures has no significant effect on the thermal fatigue of the solder.…”

1000 °C High-Temperature Wetting Behaviors of Molten Metals on Laser-Microstructured Metal Surfaces

“…However, only few literature studies focused on the wettability of molten metals at high temperatures (e.g., 1000 °C) compared with the wettability studies on more common liquids under more gentle conditions, such as water and low-melting-point liquid metals at room temperature. − Various simulations have been performed to predict the probable wetting behaviors of molten metals on various substrates, − but practical observations remain scarce due to the availability of materials and the strict environmental requirements. Among the restricted experimental work, researchers prefer to improve the wettability of molten metals with several kinds of solid surfaces for better performance in welding, brazing, metal-based composite formation, and lithium battery preparation. − ,− For example, Wu et al proposed a method to enhance the wettability of a kind of room-temperature gallium-based liquid metal on polyacrylate surfaces for a better connection, Fan et al modified the wetting and spreading behaviors of Sn on the SiC surface by changing the content of the alloying element Cr, Li et al enhanced the wettability of molten high manganese steel with Ni–Co-coated ZTA ceramic particles to strengthen the abrasive wear resistance of the composites, and Sui et al studied the wetting ability of molten Ce and Cu–Ce alloy on various carbon materials. Liu et al introduced ultrasonic power to improve the wetting of the Zn filler on the TC4 alloy and further strengthen the mechanical properties of the brazed joint, and Griffith et al investigated the effect of droplet size on the wetting behaviors of molten Sn on copper substrates for better performance of microsolder joints.…”

“…On the other hand, limited publications studied the effect of surface microstructures on the wetting behaviors of molten metals on substrates at high temperatures, while most of them concerned about the composition of the melts and the substrate surfaces or the periphery conditions. − ,,− , Lai et al found that a microporous copper substrate enhanced the wetting of molten Sn, while Zhou et al structured the steel mold surfaces to weaken the adhesion of the molten and resolidified Al alloys with the mold by preventing their full wetting. Liu et al discussed the effect of laser-textured stainless steel surface structures on the wetting and spreading behaviors of the Al–Si alloy in the presence of flux, and Lin et al observed that rough silica surfaces improved the spreading of the Sn–Ag–Ti alloy.…”