Effect of alloy particle size and stencil aperture shape on solder printing quality

Abstract

Purpose Reflow solder joint quality is significantly affected by the ability of the solder to perfectly fill pad space and retain good solder joint shape. This study aims to investigate solder joint quality by quantitatively analyzing the stencil printing-deposited solder volume, solder height and solder coverage area. Design/methodology/approach The dispensability of different solder paste types on printed circuit board (PCB) pads using different stencil aperture shapes was evaluated. Lead-free Type 4 (20–38 µm particle size) and Type 5 (15–25 µm particle size) solder pastes were used to create solder joints according to standard reflow soldering. Findings The results show that the stencil aperture shape greatly affects the solder joint quality as compared with the type of solder paste. These investigations allow the development of new strategies for solving solder paste stencil printing issues and evaluating the quality of solder joints. Originality/value The reflow soldering process requires the appropriate selection of the stencil aperture shape according to the PCB and the solder paste according to the particle-size distribution of the solder alloy powder. However, there are scarce studies on the effects of stencil aperture shape and the solder alloy particle size on the solder paste space-filling ability.

Effect of PVD-coated wall aperture roughness on the life span of fine-pitch stencil printing

“…On top of this, stencil printing technology has become critical in the era of the miniature, where finer pitch components are used in applications such as mobile or system-in-package devices (Franke et al , 2021; Mohamed Sunar et al , 2022). Thus, the process windows have become smaller with little to no space for error in the process.…”