Toward reducing no-clean flux spatter during reflow soldering: Investigating the effect of flux type, solder mask, and solder pad design. (September 2022)

• Record Type: Journal Article
• Authors: Veselý, Petr; Dušek, Karel; Froš, Denis
• Is Part Of: Journal of manufacturing processes. Volume 81(2022)
• Page Start: 696
• Page End: 706
• Publication Date: 2022-09
• Subjects: Flux spattering -- No-clean flux -- Reflow soldering -- Reliability issues -- Solder mask; Production management -- Data processing -- Periodicals; Manufacturing processes -- Periodicals; Procestechnologie; Productietechniek; Production -- Gestion -- Informatique -- Périodiques; Fabrication -- Périodiques; Manufacturing processes; Production management -- Data processing; Periodicals; 670.5
• DOI: 10.1016/j.jmapro.2022.07.027
• Languages: English
• ISSNs: 1526-6125

Abstract

Abstract: This comprehensive study dealt with the reliability issue of no-clean flux spattering from the solder paste during the reflow soldering process. Several factors entering the process were investigated: the type of flux in the solder paste (ROL0/ROL1 according to the IPC J-STD-004B standard), the type of solder mask (liquid photo imageable/directly printed), and the type of solder pad design (copper-defined/solder mask-defined). A unique design of the test board was developed for a proper evaluation of flux spatter spots spattered from the solder paste. The testing board included real-sized soldering pads and a boron-silicate glass slide as a target area, ensuring the same evaluation process for all samples. The results showed a strong influence of flux chemistry on spattering. Changing the flux from ROL1 to ROL0 reduced the flux spot occurrence by 62 % on average. The type of solder pad design also slightly affected the flux spattering. No significant difference was found between the used solder masks; therefore, it is possible to use the novel, directly printed one without increasing the risk of flux spattering. Highlights: The probability of flux spattering is significantly higher for flux with higher content of halides The probability of spattering is slightly affected by solder pad design For the used size of solder joints, no significant difference between solder masks was found The presented evaluation methodology was verified as an appropriate tool for practical analysis of solder flux spattering