IF YOU ARE SEEING PINHOLES ASSOCIATED WITH THE HOLE WALLS THEN YOU PROBABLY
HAVE TRAPPED PLATING SOLUTIONS BETWEEN THE HOLE WALL AND THE FIBER-GLASS
SUBSTRATE. BAKING OF PWBS PRIOR TO SOLDERING WILL FREQUENTLY RELEAVE THE
PROBLEM, BUT WILL NOT TOTALLY SOLVE IT. USING A SMALL BALL BEARING TAPED TO
THE BACK SIDE OF THE HOLE AND A MICROSCOPE YOU CAN VIEW THE ENTIRE INSIDE OF
THE PLATED THRU BARREL TO CHECK FOR PROTRUDING FIBERS OR GAPS IN THE PLATING
WHERE THE GASSES OF ANY TRAPPED SOLUTION CAN BOIL/BUBBLE OUT OF THE HOLE
WALL AND CREATE PIN HOLES. A GOOD BOARD HOUSE CLEANS OR BLASTS THE HOLES
BEFORE PLATING TO ASSURE GOOD PLATING. AFTER BAKING YOU MIGHT TRY DRY
NITROGEN BACKFILLING OF THE BAKING CHAMBER AND THEN STORING THE BOARDS IN
DRY NITROGEN UNTIL READY TO BE SOLDERED.
Ron Dieselberg
Cincinnati Electronics Corp.
Mason, OH 45243

-----Original Message-----
From: Nicholas LAI [mailto:[log in to unmask]]
Sent: Saturday, September 18, 1999 00:01
To: [log in to unmask]
Subject: [TN] Poor solderability


Hello all

Is there anyone can give me some info of pin hole in PTH.
Our end-customer complain that there is poor solderanility of our product.
After micro-section teh problem hole. there is some pin hole on teh PTH
wall. Is
this is teh root cause of the poor solderability.
Any comment?


More, is there any reasons can cause poor solderability(non-wetting)?

Is there any good source can know more about the poor
solderability(non-wetting)?

Best Regard,
Nicholas Lai
9/18/99

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