Hi:

One of the ways development laboratories determine coating thickness is by
measuring dry coating weight. For filled soldermask, a coating weight
between ~35-40 mg/100 sq. cm translates into 2.5 microns thickness.
Unfortunately, this is only an average thickness over the entire board,
lines etc., but it is indicative to some degree of coating thickness. In the
case of unfilled organic materials, the factor is ~30 mg/100 sq. cm. These
values were obtained by measuring densities of the materials and converting
these to the above factors using actual measurements.

Leo Roos
----- Original Message -----
From: "Bissonnette, Jean-Francois" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, March 14, 2002 6:58 AM
Subject: [TN] Coating thickness


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