John,

I agree with Fred Paul, Tetra-Etch (Metalic Sodium and Naptha) and Shipley
(250, 321,  the old stuff).  In a different life, we ran small lots of PTFE
with normal FR4 production.  The only thing I want to add is that the PTFE
boards would look great, but the next two to four lots of FR4 run right
after the PTFE lots would be prone to voids.  Assumed it was Naptha in the
baths.  Soooo, (like any seat-of-the-pants production shop), we always ran
the PTFE as the last racks of the shift.  Never had problems the next day.
Baking the PTFE did not seem to make a difference.  It looked like an
activation problem, but since another solution exisited, the possiblity was
never pursued.  If your production is up, this may be a direction to
follow.

Smear problems were usually traced back to wrong feed/speed settings, bad
drill bits, Drill-type stuff.

As an aside, we were fortunate in that we had an operator who kind of liked
the smell of naptha.



>Mr. Gully,
>        When we (at FLUKE PCB Mfg. Operations) used to produce Teflon PCB
>Multilayers,
>we sandblasted, deburred, and then applied Tetra-Etch, (or Bond-Aid
>TL5-12) to the holes.  We then processed
>them through our normal Shipley Electroless Copper Process.  We had very
>good results, however, the
>process was not designed for large numbers of PCBs.  We used 3M Co.
>Bonding Film No. 6700 as the
>thermoplastic bonding agent.
>
>References:
>
>Tetra-Etch
>W.L. Gore & Associates
>1505 N. Fourth Street
>P.O. Box 1389
>Flagstaff, AZ 86002
>(602)526-1290
>
>
>Bond-Aid TL5-12
>Shamban West
>24412 S. Main St.
>Suites 101-103
>P.O. Box 4997
>Carson, CA 90749-4997
>(213)513-6656
>
>RT/Duroid
>Rogers Corporation
>Microwave Materials Division
>100 S. Roosevelt Avenue
>Chandler, AZ 85226
>602  961 - 1382
>
>
>Regards,
>
>FRED J. PAUL:   [log in to unmask]                        FLUKE CORPORATION
>Sr. Process Engineer                            POB 9090   M/S 55
>PCB Operations                                  EVERETT, WA 98206
>direct: 206 356-5734   fax:     206 356-6070            Corporate:
>206 347-6100


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