Issue link: https://iconnect007.uberflip.com/i/1181966
86 SMT007 MAGAZINE I NOVEMBER 2019 SPI Data Solder paste inspection (SPI) data was acquired for each component. For the thermal pad, the apertures were numbered, and each solder paste deposit was measured against the calculated tar - get value based on the apertures' sizes. For the components leads, the apertures were reduced by 10%. The I/O were not overprinted so that upon melting and coalescence, the solder paste deposits would not lift the com- ponent and inadvertently interfere with the experiment hypothesis. The solder paste vol- ume distribution for the I/O is shown in Fig- ure 8. The mean of each distribution is slightly less than the target value of 1060 mil 3 of sol- der paste. Figure 7: Reflow profile of a 130-mil board. Figure 8: I/O solder paste volume by board.