At our company, we reduced the amount of vacuum we pull and coated the back
of the film with a Teflon release film, Filmguard PPF1, from CIS. Both had
a measurable effect.


At 05:05 PM 9/1/98 -0400, you wrote:
>TechNet:
>
>We are getting a condition known as "artwork marking" when exposing LPI
>soldermask. This condition exhibits itself as shiny areas where the artwork
>comes into contact with any high spots on the mask.
>Although it appears to be totally cosmetic, we have a few customers who
>refuse to purchase boards with this condition.
>
>We primarily use Electra EMP110 soldermask with a Teledyne DSA 2000 spray
>coater. The panels are then tack dried in a tunnel oven for 45 minutes at
>180F.
>
>When imaging the panels, the top side (against the mylar) seems fine but
>the bottom (against the glass) is marked. The degree of marking varies
>depending on the surface of the board.
>
>Has anyone else seen this problem, or had the need to eliminate it?
>Also, what method do you use to ensure sufficient tack dry prior image, if
>any?
>
>Any responses would be appreciated
>
>Thank You
>John Lennox
>Process Engineer
>EMC
>
>################################################################
>TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
>################################################################
>To subscribe/unsubscribe, send a message to [log in to unmask] with
following text in the body:
>To subscribe:   SUBSCRIBE TechNet <your full name>
>To unsubscribe:   SIGNOFF TechNet
>################################################################
>Please visit IPC's web site (http://www.ipc.org) "On-Line Services"
section for additional information.
>For technical support contact Hugo Scaramuzza at [log in to unmask] or
847-509-9700 ext.312
>################################################################
>

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################