Issue link: https://iconnect007.uberflip.com/i/304995
May 2014 • SMT Magazine 39 no special focus on color, supplier or process. Solder mask A and B, as well as underfill B, are the same used in the drop test DOE; all other solder mask inks have not been cross compared by drop shock test. Figure 9 shows that the total surface energy (equal to the sum of the polar [blue] and the dispersive part [red]), displays notable differenc- es between the solder mask inks, and likewise for the underfill. It can be assumed that two ma- figure 8: fowkes theory. Figure 7: Schematic overview of adhesion determination. mECHaNICaL RELIaBILITy continues feATuRe