>     Has anyone experienced Deep or Tab gold plate passing tape test at the 
>     precious metal process, only to have gold peel after the Hot Air 
>     Solder Level process.
>     
>     Thanks
>     
>     Carlos

Hello Carlos,

The main area to check is your pre-treatment prior to nickel or gold
plating. Make sure you have a good micro-etch to remove any
intermetallic layer and get the copper surface active.

When loading the nickel or gold bath, you must ensure that there is
sufficient voltage to give correct amps for each panel and this must be
stepped up as you load the bath. If you use a gold strike this also
applies. Going into the nickel or gold bath with too little or too much
current can cause adhesion problems. If you are nickel plating first
then it could be a passivation problem caused by not transferring the
panel quickly enough to the gold bath.

Stress can be a factor and this will show up on your porosity test as
horizontal cracks across the contact surface. The end contacts are
usually the worst as they get a higher current. If the stress is high
and you plate too much gold then the bond can fail after thermal shock.
If the deposit is stressed, this may be due to organic contamination
which can be reduced by activated carbon filters.

Hope this helps
-- 
Paul Gould
Teknacron Circuits Ltd
[log in to unmask]
Isle of Wight,UK

***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To subscribe/unsubscribe send a message <to: [log in to unmask]>   *
* with <subject: subscribe/unsubscribe> and no text in the body.          *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact   *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      *
***************************************************************************