You should fill the hole. There are a number of good epoxies to use. I can suggest Eccobond or Resiweld, which are clear, or a good two-part soldermask epoxy that dries hard with excellent adherance, such as Taiyo America TCHP-200 http://www.taiyo-america.com/products-hf.asp. This is an excellent epoxy, low outgassing, completely insulative, excellent adherence, compatible with liquid soldermask already on the pwb, and when cured blends in quite well. When mixed, this "elephant snot" is quite viscous, yet it can be controlled when dispensed from a 5cc tube with a hand-held pneumatic manual dispenser, and does not run. Fill the hole, then place a piece of Kapton tape over the hole, cure in an oven, peel away the tape, and you will have a nice flat finish. The tape does not stick to the epoxy. For military applications, keep the unmixed resin and hardener in a standard refrigerator, and mix only the amount you need to use, discard the unused portion. For less critical applications it can be mixed and used several times and be returned to the refrigerator for up to about a month before it should be discarded. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Kerry McMullen Sent: Wednesday, August 15, 2007 1:28 PM To: [log in to unmask] Subject: [TN] Drill Rework Hi, I have a .062 FR406 board where I need to drill out a trace that is causing a problem. The trace is .020" down in the board (Layer 4). The drill size is .012. After I have drilled out (opened) the trace, what do you suggest I fill the drill hole with? We have done the rework, and it works fine. I am just curious as to if I should fill the hole with epoxy. Thanks in advance, Kerry Kerry McMullen Principal New Product Mfg. Engineer LTX Corporation 825 University Avenue Norwood, MA 02062-2643 (T) 781-467-5468 (C) 508-631-1832 (F) 781-461-0993 --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------