Trip Report –
The primary purpose of this trip is to resuscitate MCM
production. Production was started last
I arrived on site at
Ana C. worked in wire bonding. She called for help because of operational difficulties. The automated program would not bond to the Pitch Adapter, and she had to manually guide it in for each trace. She was part way through one board, and started on a 2nd one to find the problem was not unique to one board. Steve(?) looked at it, and concluded that the traces were too narrow to bond to. Under high magnification, it was obvious that traces are narrower than the gap between them. Width looks uniform. We measured one trace on MCM S/N 2082 to be 72 mm. Another board looked similar but we failed to record either the S/N or the actual width. Both used PA from Titan. We measured a board used for wire bond pull tests, and found trace width to be 103 mm. Trace width and gap are approximately the same size as one would expect. We also measured a new MCM that has just been bonded, and found a trace width of 102 mm. This one used Parlex PA made last year. All these measurements were made on the same machine with the same technique. I called Richard Gobin and asked for a check on new Parlex PA. He measured several traces using calipers and a microscope, and found trace width to be around 120 mm. Traces and widths are about the same size. Tom Nakashima has been asked to make more precise measurements. I conclude that the problem is with the Titan PA. There is no reason to panic regarding the new Parlex PA. I would suggest that we do not measure trace widths as a routine part of Parlex PA acceptance. Spot checks may be useful.
The initial diagnosis was the traces were too narrow to bond
automatically. It would have to be done
by hand at a rate of roughly one board per day, compared with one every 30
minutes when done automatically.
Jerome Lepulu and I met with
Item |
Date (1st
5) |
Date (2nd
5) |
SMT |
Done |
2/10 |
Connector |
Done |
2/11 |
Die attach |
2/10 (1 unit, others done) |
2/14 |
Lead bonding |
2/10 – 2/11 |
2/15 |
MIP-2 |
2/14 |
2/16 (starting |
QC |
2/15 |
2/17 |
Encapsulation |
2/16 |
2/18 |
Conformal coating |
2/17 |
2/21 |
Final Test |
2/18 |
2/22 |
Final Inspection |
2/21 |
2/23 |
Ship |
2/22 |
2/24 |
Ayub expects the 25 new units to
be ready for MIP-1 inspection on Monday 2/14.
He is not sure about the dates for each step. He will keep us updated regularly.