Production Support and Test of TESLA 3000 AIB using GPIB

After performing the design and full verification of the TESLA 3000 AIB, Elecsys was asked to support the manufacture of the boards at Trilogy-Net in Calgary.  There were challenges in getting the boards to work, mostly because of the silly little LM358BP, which is in a tiny 8 microbump package.  We had process issues on getting it to solder properly.

In the end, the fault was the layout that I had supervised.  Unfortunately, in our desire to pack everything onto one side of the board, I had moved down to the absolute smallest package of the LM358 dual op-amp.  Well, in the end the board layout person went to double sided assembly but didn’t tell me until the last minute, meaning that the tiny op-amp stayed.  There were larger parts around the op-amp that drew the heat out of the oven, so the op-amp wouldn’t solder consistently.  This was a headache until a couple of years ago, when that op-amp was finally replaced by the larger SOIC version.  Sigh.

Anyway, we wanted to do a 100% test of the AIBs to ensure proper function before TESLA assembly.

I acquired a number of surplus IEEE-488 / GPIB test equipment and a PC GPIB card, and wrote scripts in PERL to control the test equipment.  We were able to drive precise voltages into each channel, to test offset and gain, then certain frequency signals to test filter response.  Data was logged, analyzed, then the aggregate data was reviewed continually to calculate statistical process control.