Jim What types are there? Acrylic - Polyurethane - Silicone - Epoxy and many specials/mixes. Air curing, moisture curing, heat curing, UV curing or combinations of these. Materials may be solventless 1 part, low or no VOC solvent based, or good old fashioned "takes the paint off your decks if you have a boat". How easy are they to apply? In most cases easily but there are tricks to every trade. e.g. Ideally a coating should be 1 component - fast curing - long stable pot life - easily reworkable (for example you may want to get it off the floor when you spill it!) Applying such materials may be done using dip techniques, spraying, dispensing or brushing. Ideally a coating should be under as well as over the components to maximise the available protection thus dipping is usually the most efficient and economic method of application. However, this may be too expensive because of the amount of component masking that may need to be done. For this reason, either selective coating methods using robotic dispensing can be used or conventional spray systems where masking is reduced to a shield rather than a barrier can be employed. What will it cost? Depends upon a number of things but you could pay less than £0.05 ($0.08) per board all-in including capital and material. On the other hand, it could cost you more than £30 ($50) if the total masking/de-masking and rework time exceeds 1 hour per board. The material is the smallest part of this equation as you SHOULD be able to coat around 150 6 inch x 3 inch assemblies per US quart or 1 litre. Bear-in-mind that the prevailing US MIL-I-46058 spec recommends 0.001 inches to 0.005 inches coating thickness in the cured state. We have a simple computerised cost model for this if anyone is interested. Is it possible to remove after application for rework (spillage) etc.? All coatings are repairable however, a hammer and chisel may be considered too severe. Acrylics are generally more easy to repair than others because they may be dissolved by relatively mild and environmentally benign solvents. I hope this helps you but we do have a lot more. Lest I be accused of spamming, let me know off line and I will send you more and any other Technetters that may be interested. Graham Naisbitt __________________________________________________________________________ [log in to unmask] Concoat Ltd Alasan House, Albany Park Camberley GU15 2PL UK http://www.concoat.co.uk Application Engineers in Chemical Compounds to the Electronics Industry -----Original Message----- From: Jim Hedderick <[log in to unmask]> To: [log in to unmask] <[log in to unmask]> Date: 19 January 1998 16:29 Subject: [TN] CONFORMAL COATINGS ON PCBS >I have just been asked a question about conformal coatings on printed circuit boards >and I can remember this question arising on this forum some time in the past. >I would again like to bring this subject up to try and find out some of the following answers. >The board I wish to apply this coating to is to be used in a high humidity environment > >(I) What type of conformal coatings are available ?. > >(ii) How easy is it to apply?. > >(iii) What will it cost?. > >(iv) Is it possible to remove after application for rework etc?. > > Thank you > Jim Hedderick > >############################################################## >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. >For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 >############################################################## > ############################################################## 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. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################