This email contains a transcription of the Wire Bond Failure brainstorming session including the potential causes and actions agreed to.  Please give it a quick review and I'll revise it as necessary and send it out again to a more complete distribution (Tom please suggest) by the end of today. I assume we will discuss the status of this tomorrow at time/phone-number TBD.

I do not have contact info for Brian, Rhonda, and Charley. Nor do I have contact info for John and Bill (actionees for failure mechanism modelling).  Anyone who does please forward to me. Thanks.

Potential causes:

1.      CTE Mismatch in transverse (out-of-the plane of the MCM) direction.  [9]
2.      Wire-bond materials
      Process changes [4]
      Encapsulation material change or variability [2]
      Constraints on the board (there are more failures seen in the middle) [6]

6.      Silicone tape residue [6]
      Pre-heat step on board
      Bonds damaged before coating applied

9.      Handling at Teledyne, SLAC, Italy
.     Wire-bond process
11.     De-lamination of kapton/rework of flex attachment
12.     Change (plastic to aluminum) in burn-in fixture

Near-Term Actions:

1.      a) Review Process (7108742) for any changes (Brian –due 12/7)

b) Review Operator changes if any (Elvia – due 12/7)

2.      Model failure mechanism to prove/disprove CTE theory #1 above (Paul Baird /John/Bill – due 12/7)
3.      Ask adhesive experts (Hysol) to review MCM application. (Brian/Phil – due 12/8)
4.      Cross-section more boards including a failure-free area. (Robert/Diane – due 12/9)
5.      Identify kapton surface prep methods (e.g. chemical)  (Phil/Fred Gross – due 12/7)
6.      Prototype fiber-glass cover to two levels of fidelity 1) mount cover on bead 2) build up cover from three layers – (Robert – due 12/7)

Other actions:
The following list of actions needs to be considered when the root cause is identified and corrective action(s) are developed.

1.      Determine the disposition of the existing MCMs.
2.      Review thermal test requirements both ramp-rate and extremes to determine if they can be relaxed.
3.      Review the results of the thermal vacuum and vibration tower test to be completed in the next 2-3 weeks.


Dick Quinn     
Lockheed Martin IS&S
P.O. Box 8048
Rm 1168 Bldg 10
Philadelphia, Pa. 19101
(       Voice-mail: 610.531.5692
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