In message <[log in to unmask]> [log in to unmask] writes: > We have an application where we need to apply temporary solder mask prior > to a high temp bake in preperation for wave solder. These are polyimid > boards and we bake them at 125C for 12 hours prior to wave solder. We try > to wave solder them as soon as they cool to ambient so applying mask after > bake is out of the question. > > We have two different masks we currently use that are water-soluble. > Neither one comes off very well in the water wash and one of them leaves a > residue/stain due to the high temp bake. > > Do any of you have a source for a temporary solder mask that can hold up to > this temp/time and still be removed easily without residue (preferably with > water)? I think one of the problems here is that many of the water soluable solder masks need to be re-saturated before they start dissolving. When you have baked them at over 100C for a long time, there is no residual moisture left in the mask, so the re-saturating process takes a long(er) time. You could try increasing the water temperature, water pressure or immersion time to get better removal. Perhaps a pre-soak? A different kind a mask chemistry might also be tried - a couple of names which haven't been mentioned in this thread are worth contacting in this regard, Tech Spray and Dymax. Peter -- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Peter Swanson Oxfordshire, England INTERTRONICS [log in to unmask] http://www.intertronics.co.uk Suppliers of materials and consumables to the electronics & related industries ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ############################################################## TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################