Rob van Pol wrote:- >We have tried peelable solderresists but these are not 100 % >resistant to the pressure during horizontal hot air levelling resulting >in P/Sn particles on the Ni/Au contacts. Hi Rob, You are on the right track with peelable but maybe you are not coating sufficient thickness. You really need a very thick coating of around 20 mils to be able to withstand the levelling air knives. I have no experience of horizontal levelling but it must be much the same as vertical to the peelable. There are other types of water soluble non-peelable masks if you want to get into more water washing. Fortunately, I have not needed to go that far and so again have no experience of these. Stick with the peelable method and try to make it work. Good luck, -- Paul Gould [log in to unmask] Isle of Wight,UK ############################################################## 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 ##############################################################