Good day, TechNet -

	Can't help needing to post in this time of too much traffic.
	Perhaps you'll soon see why:

	I've been asked to make a soldermask change on a very dense,
	double-active, sensor type design.  The assembly is subject
	to In-Circuit-Test, and the non-test-side clearances are such
	that the contract manufacturer is requesting that we tent the
	testpoint vias on the non-test side.  There are troubles with
	solder shorts.

	The board is HASL, 2x reflow, with hand solder, and an aqueous
	cleaning process.  The soldermask is LPI.  Volumes are modest.
	The via geometry is small, such that the current soldermask
	appears to give a reliable covering.

	The application is life support.

	My fear is that one-sided tenting will allow entrapment of
	processing chemistry and will not allow adequate cleaning.
	It would seem to me that switching to OSP or shrinking the
	via clearance to just above the finished hole size would be
	a safer alternative for long term reliability.

	Can a sometimes-too-conservative ol' design guy draw out any
	support or denial opinions?

	Thanks in advance, and regards,
-- 
 
      Jeff Seeger                             Applied CAD Knowledge Inc
      Chief Technical Officer                      Tyngsboro, MA  01879
      [log in to unmask]                               508 649 9800

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