Issue link: https://iconnect007.uberflip.com/i/1345210
MARCH 2021 I SMT007 MAGAZINE 51 that a DFM check should be done at the library level using any of today's industry tools, such as Siemens' Valor VPL. A DFM check and verification of a footprint for both fabrication and assembly should be done as early in the design process as possi- ble. When done at an early stage, a design will have a higher percentage of success right out of the blocks, with no potential missed footprint design errors to worry about. A bad pin can easily be identified within seconds utilizing such a tool. A thorough DFM check between the 3D industry model of the component against the designed footprint, along with the appropriate solder fillets and overall assembly concerns, can also be quickly addressed to pre- vent downstream issues as well. is is what we now refer to as a shi-le approach. In this design, no assembly DFM verifica- tion was ever performed. e board was rede- signed successfully. Vino worked out the finan- cial compensation with that third-party library team, but it was the last and only time Vino and I used them. SMT007 Stephen V. Chavez, MIT, CID+, is chairman of the Printed Circuit Engineering Association. Figure 1: Photos showing the top and bottom of the CCAs that overheated due to a simple footprint error. Note the backplane controller BGA in the center of the bottom side of the board; this one CCA represents $5,000 out the window.