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74 SMT Magazine • September 2015 solder paste printing, Component placement, and soldering Conditions A. Sample Boards Design 1 and 2 Standard production automated assembly equipment was used to apply solder paste, place components, and control solder condi- tions in both the assembly of the design 1 and design 2 sample boards. Raytheon standard solder process conditions were employed with both the design 1 and design 2 sample assem- blies. Conditions recorded include soldering at 215°C +/- 2°C for 60–90 seconds, use of 63 Wt% tin, 37 Wt% lead solder, 5 and 6 mil sten- cils, and R0L0 flux. No manual touch up of component placement or soldering processes was performed, to avoid introducing variabil- ity in the project results. We made six copies of the design 1 board, and eight of the design 2 board. A few locations on each board design were not populated with components, either due to board layout issues or insufficient sample quantities. B. Multi-Chip Module Due to the proprietary design of the MCM only the general solder process con- ditions are released in this article. Tin-lead solder was used with the solder profile shown in Figure 6. ArtiCle tIN WHIsKer seLF-mItIGAtION IN surFACe mOuNt COmpONeNts continues figure 5: Multi-chip module. figure 6: McM solder profile.