Hi Sarah,
I think it highly unlikely that this would be the case. Even if the plating
was slightly thicker in the hole, the base copper on the surface would add
to the plated copper so there would always be more copper on the surface
than in the hole, unless the surface plating did not take place due to some
kind of masking.
Normally 0.001" of copper is plated on the circuit pattern and through the
holes. On the laminate base, the standard 1oz copper is equivalent to
0.0014" thickness. Even allowing for losses due to brushing and micro-etches
etc, there should still be at least 0.001" of surface copper to add to the
0.001" plated copper.
I am intrigued as to why you asked the question though.
Regards
Paul Gould
Teknacron Circuits Ltd
UK

-----Original Message-----
From: sarah <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: 29 July 1998 14:42
Subject: [TN] Plating Thickness


>Hi everyone
>
>Please pardon me for my ignorance regarding this
>matter but I will ask this question anyway:
>- is it possible that the plating thickness on the board
>  surface is less than that of the T/H?
>- what might be the cause of this type of phenomenon?
>
>Any comments or information anyone could provide
>is highly appreciated.
>
>

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