Ivan,

One method is to use a laser for this Soldermask removal.  I have done it several time recently for smaller areas where we used a mask made from thin core copper.

Larry

----- Original Message ----- 
From: Ivan Barrios <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, April 26, 2000 12:14
Subject: [TN] Removal of Solder mask


> We need to remove a small area (0.120" x 0.100") of soldermask from the top
> layer, without removing any of the copper underneath. Is there a chemical
> used to "etch" out this soldermask, and not compromise the copper layer
> underneath? As always, your responses are most welcome
> 
> Ivan Barrios
> 
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