Hi Nancy - I'm not sure I fully understand your application or your suppliers process in this case, but let me give you a few thoughts. I am not aware of any U.S. or overseas specifications dealing with the properties of removable masks. I would expect this to be because these materials are not normally end item identifiable or deliverable materials. Here goes with the thoughts: If the circuit trace has even the slightest amount of a fusible alloy (such as tin/lead plating or solder coating) in the area that the removable solder mask is applied over, then that material will melt when you reach its reflow temperature. Melting will in turn cause it to lose its bond to the removable solder mask, and allow seepage to occur; If the removable solder mask is exposed to process temperatures higher, or for a period longer than its formulator/manufacturer rates it for, then its bond to the circuit trace may fail and allow seepage. The answers for this should be available in the formulator/manufacturers data sheet. Improper cure or processing of the mask duriing application could produce similar faults; If the board surface was not properly prepared/cleaned, or the surface was not compatible with the removable mask, it could account for these conditions. Let me know if any of these items start to strike a familiar chord with this problem, and we'll trry to take it a step further. Regards - Kelly -----Original Message----- From: Nancy Trumbull <[log in to unmask]> To: [log in to unmask] <[log in to unmask]> Date: Thursday, October 07, 1999 7:15 AM Subject: [TN] Removeable Solder Mask HI Technetters, Every one did so good for me on the electrical migration that I'm back. Problem: Solder is seeping under the removable solder mask during wave solder. Key word :REMOVABLE Investigation: Indicates Poor process at the supplier Supplier states "that this problem is typical of removable solder mask made in the states". Key words :made in the States. Because they can not use the same type of material as over sea. I have IPC-SM-840C Qualification and Performance of Permanent Solder Mask This does me no good. Our Supplier will remove some of the ID landing. Which should stop the seepage during wave solder. But I would like more information on Removable Solder Mask Standards in the States. I have ask for information on removable solder mask before and got no reply . Could this be something fairly new for the states? My pass experience has always been with over sea suppliers for this type of product. Thanks to all that reply in Advance Nancy ############################################################## 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 ############################################################## ############################################################## 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 ##############################################################