Hi Muralidhara,

There are two ways of overcoming the below mentioned problem of gold plating
thickness getting reduced.
1. Don't use a mechanical brush to roughen the copper surface after the gold
plating process to improve soldermak adhesion, instead use a chemical clean
process or a pumice powder cleaning process, in this way the gold thickness
will not be reduced.
2. You could do the gold plating process after the soldermask provided the
key pads have tie-bars which can be disconnected after the gold plating
process & the soldermask is robust enough to withstand the nickel & gold
plating chemistries.

Thanks,
Krishnan
SANMINA-SCI
Quality Assurance / NPI Manager
E-mail: [log in to unmask]
Phone (Off): 082-363000 Ext. 1602
Mobile: 012-8888-379

-----Original Message-----
From: Murulidhara S [mailto:[log in to unmask]]
Sent: Saturday, February 21, 2004 4:39 PM
To: [log in to unmask]
Subject: [TN] gold plating on key pads

Dear technetters

We are doing solder mask on key pad pcbs after gold plating. In this
process,gold plating thickness is reduced during mechanical scrubbing
operation which is done just before solder mask flooding. Is there any
solution to avoid reduction of gold plating thickness?

Also let us know, whether gold plating can be done after the solder masking
process? If so briefly explain the process.

Regards,

Mr.Murulidhara S.
Deputy Chief Engineer ,
PCB and Chemical Lab - R&D,
ITI Ltd. ,
Dooravani Nagar ,
Bangalore
INDIA
PIN-560 016

Ph : 91-080-8503959
Fax : 91-080-5650971



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