Tony,

I believe that the problem is that the manufacturing process requires
filling a blind hole with CB100.  If the blind vias were cross sectioned,
one would probably find that there were air voids in the CB100.  IMO, it is
impossible ( at least extremely difficult) to reliably fill a blind via with
a viscous material.  The failure mechanism is most likely expansion of the
entrapped air in the blind via causing the plug to "explode".

Is there a reason for laser drilling blind vias .030" deep?  I would think
that conventional sequential lamination with resin filled, copper capped
blind vias would produce a functional, reliable board.  A blind via with a
2:1 aspect ratio also has to be causing some interesting metallization
challenges.

Don Vischulis

-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of tony steinke
Sent: Wednesday, May 29, 2002 3:10 PM
To: [log in to unmask]
Subject: Re: [TN] conductive blind via plug


Don, Russ, Rush
The application is a blind via under BGA pad. The process sequence is:
Lase via
electroless
full panel electroplate
CB100(lase vias only)
flash electroplate
drill
electroless
image
pattern plate
strip/etch
Thanks for the input.
Tony Steinke

  -----Original Message-----
  From: TechNet [mailto:[log in to unmask]]On Behalf Of tony steinke
  Sent: Wednesday, May 29, 2002 11:33 AM
  To: [log in to unmask]
  Subject: [TN] conductive blind via plug


  Techies,
  We have done some initial testing on the  DuPont CB100 conductive via plug
with blind via application and so far have been unsuccessful. The blind via
is approximately .016 diameter and .030 in depth. The biggest problem we are
experiencing is getting adhesion(BGA pads popping off) with
  copper plating after the CB100 has been applied. Is there
  another type of conductive blind via plug recipe on the market.
  Thanks for any comments
  Tony Steinke