Issue link: https://iconnect007.uberflip.com/i/911509
48 SMT Magazine • December 2017 Print Test Procedure Before the main experiments, a pretest was conducted to select the parameters for the squeegee speed, squeegee pressure and the sep- aration speed using solder paste A. Parameters were determined by the DOE Optimization function within the Minitab software program and established per paste type. For each exper- iment 125 grams of solder paste material was used in combination with 200 mm long 60° SS squeegees. Table 4 identifies the equipment and print test parameters used in this study. The test routine (Figure 3) consisted of start- ing with four knead printing cycles, followed by an automatic under stencil wipe and then proceeding to the formal printing test sched- ule whereby SPI data collection commenced. Ten boards were printed at fast squeegee speed followed by ten more boards printed at slow speed. This test print sequence was repeated twice each using both paste brands and types for all three stencil thicknesses. The under-sten- THE EFFECT OF AREA SHAPE AND AREA RATIO ON SOLDER PASTE PRINTING PERFORMANCE Table 4. Experimental tools and setting. Figure 3: Print test sequence with 480 total prints.