sorry to but in on this one, but with the work i have done with several customers in the past few weeks - opens and shorts - and a few other problems diriving from dry film processing - is not an open and shut case. i have found that both in processing dryfilm and LPI - board manufacturers are not adhereing to actual breakpoint specs - recommended by their resist and LPI suppliers. exposure step - actual developing solution concentration - pH inflection points - correlating to the type of dry film and LPI being used - rinse temperatures - pressure - all play a big part in actual developing of the polymer. either one or the other, or all of the above were out of sink when a customer has had problems with dryfilm or LPI. though not as noticeable with LPI - it makes a difference when your next step after LPI developing is an electroless finish. i have seen panels exiting developers with positive foot on component side and negative foot on solder side - shorts on one but not the other. for some strange reason - board manufacturers are more concerned about solution contact time - either long or short ( usually depending on what they think is wrong ) rather than the actual overall parameter of how the film is actually to be processed. customers switching from a 1.5 film to a 2.0 mil film run into tremendous problems for the first few days. but then, we only look at the tech data sheet when all else goes wrong. i would be very interested in knowing how actual parameters for processing dryfil are implemented by board manufacturers. i sure hope it isn't - coppers exposed - tape test shows only minor lifting - not much shadows - ok!!! let's run it. Rick Fudalewski Atotech Canada Ltd *************************************************************************** * 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] * ***************************************************************************