Brian: There are several vinyl based temporary peelable masks that should work. These products can be applied by printing using an imaged screen, similar to(non-photoimageable)permanent soldermask application. They normally require a post application bake to achieve the proper chemical resistant properties and release characteristics. It should stand up to your electroplated Ni and Au processes. In some cases it is somewhat of a pain to remove depending on the size and configuration, but worth a try. Lackwerke Peters GmbH, MacDermid, Electra and Alpha Metals all used to carry these types of products. Regards Michael Barmuta Staff Engineer Fluke Corp. Everett WA 425-446-6076 -----Original Message----- From: Brian L. Guidi [mailto:[log in to unmask]] Sent: Friday, April 19, 2002 12:45 PM To: [log in to unmask] Subject: [TN] Peelable Soldermask Good afternoon fellow techies... I am searching for information on peelable soldermask, or an acceptable alternative. I have an application which requires temporary coverage of immersion gold plated fingers, through subsequent wet process operations (additional 'electrolytic' gold plating). I need to cover the fingers so they do not plate up when the electro-deposited gold is added (the nets are connected) to the other end of the board. The situation is complicated by the fact that the area requiring coverage is approximately .012" below the external surface of the board, therefore standard etch/plate dryfilm is not practical due to voiding. I'll try to provide a mental picture: Imaging a rectangular board 2" long by .500" wide. It's a 6 layer board. On one end, a portion of L4/5 about .750" long, extends beyond the rest of the part (along the length) about .400". These "wings" are the portion requiring coverage during the plating process that is happening at the other end of the board. Platers tape has been ruled out as an option due to volume. The plan is to apply a dryfilm soldermask to the external board surfaces to permanently protect/insulate the via's, and then apply a peelable mask over the same area which would conform to the 'drop-down' (.012") and cover the exposed fingers on L4/5. The peelable soldermask would then be removed to expose the fingers to the cleaning solutions. I am looking for material recommendations, vendors providing peelable mask application services, and any practical experience anyone has had with a similar situation. I hope the explanation is not too foggy. It is Friday after all, and I have a meeting with Sam Adams in about an hour and a half! Thanks in advance for your help and insight... Brian Guidi Product Engineer Teledyne Electronic Technologies Tel: (603) 889-6191 X:310 Fax: (603) 886-2977 E-mail: [log in to unmask] Any technical information attached to this document is intended for the recipient only. Also, the export and use of the information is regulated by the export laws of the United States. Diversion contrary to U.S. law is prohibited. U.S. law prohibits sharing this information with any end-user for any end-use related to the design, development, production, stockpiling or use of chemical, biological or nuclear weapons or missiles, without the prior approval of the United States Government. ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------