![]() ![]() The findings can be applied in surface-mount technology production, where the total failure count and resulting failure costs could be reduced according to the findings. Design aspects of solder beading-prone components were identified and discussed as the primary source of the problem. Statistical analysis revealed that differences between distinct components had the highest effect on the solder beading rate. Results show that excessive component placement pressure could induce solder beading. It was found that the reduction of SP volume only reduces the failure rate but does not solve the problem. Test methods were designed and performed to reveal the behaviour of the solder paste (SP) during the reflow soldering process and to emphasise the component design relevance. The surface mounting process steps were also analysed to reveal their dependence on the issue. High-resolution noncontact profilometry and optical microscopy were used to analyse component designs. To detect the failure mode, X-ray imaging, cross-section grinding, optical microscopy and Fourier transformed infrared spectroscopy were used. The large size of the involved components may block the view of automatic optical inspection therefore, X-ray inspection is necessary. In modern lead-free reflow soldering, especially in high-reliability industries, such as automotive, aeroplane and aerospace, detecting and preventing such defects is essential in reliable and cost-effective manufacturing. Solder beading could induce failures by violating the minimal electrical clearance on the printed circuit board (PCB). The purpose of this paper is to study the solder beading phenomenon (referring to larger-sized solder balls) of surface-mounted electrolytic capacitors. ![]() It does not however, greatly impact key metallurgical properties such as intermetallic layer thickness. The results demonstrated that reflow profile affects properties such as metal wetting and voiding. After analysis, the PCBs were then subjected to thermal cycling experiments to see how reflow profile impacted microstructure evolution. The PCBs were then analyzed to see how the processing variables influenced wetting, voiding, microstructure, intermetallic layer composition, and thickness. Each alloy was processed using different reflow profiles that had varying times above liquidus (TALs) and peak temperatures. The following study looks at the behavior of four different Sn–Bi alloys-traditional 42Sn58Bi and 42Sn57Bi1Ag and two new tin–bismuth alloys-in solder paste during the reflow soldering process. While certain tin–bismuth solders are well characterized many new alloys in this family have been developed which need proper characterization. Sn–Bi alloys are desirable candidates for soldering components on printed circuit boards (PCBs) because of their low melting point and reduced cost.
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