Hello Technet,
We have been experiencing problems with our soldermask lamination process.  We 
use Dupont's Vacrel 8140 dry film soldermask, and apply with an EH2400 vacuum 
laminator.  Upon removal from the laminator, we frequently see that rings have 
formed in the soldermask.  The rim of the ring is darker green, and the area 
confined by the ring is lighter green than the surrounding soldermask.  We 
have requested help/suggestions from mfg of both laminator and film, but as 
often happens, each says the problem is not with their product.
Has anyone else experienced this problem while vacuum laminating dry film 
soldermask?  Any suggestions on how to eliminate this problem would be greatly 
appreciated.
cbh

***************************************************************************
* 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]      *
***************************************************************************