I am interested in learning more about laminating dry film photoresists using the "wet lamination" technique. I have experimented wet laminating at room temperature, followed by heating the boards in an oven at 70°C (150°F) for 5 minutes. The film gives good adhesion to the copper after this heating step. However, one of the problems is that immediately after rolling, the film is primarily sticking to the copper surface via water tension, making it a problem to handle. Another major problem is trapped air inside the drilled holes, which latter expand during the heating step, and cause the film to lift around each of the holes. The film near holes looks damaged once it has cooled. How does conventional wet lamination handle trapped air ? Does trapped air cause problems ? I suspect the cooling of the panel after lamination creates a small vacuum in the holes, thereby not causing any real problems. Basically I'm am designing a small dry film laminating machine, and like to use the idea of applying wet technique. The idea is to continuously pump filtered heated water (say 50°C / 120°F) in the immediate area where the dry film and panel first contact between the rollers. I'm hoping the flowing water will be the heat source for the lamination while it also washing away surface dust contamination. Adam --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------