Frank, Acid is like rust.....it never sleeps! The acid will continue, albeit, at a slow rate, to eat away at the etch. It will take time, but it will happen. The biggest problem is that it is one of the most difficult failures to find on a board. Deac Deac Descoteaux PalPilot, East Coast Corporation, (PEC) Director of New Business Development 71 Spitbrook Road, Suite #307 Nashua, NH 03060 office # (603) 888-3400, ext. #10 Toll Free # (877) PALPILOT, (725-7456) Fax # (603) 888-3500 Cell Phone# (603) 557-7568 email address: [log in to unmask] www.palpilot.com PCB LAYOUT * SIGNAL INTEGRITY * PCB FABRICATION * METAL CHASSIS * PLASTIC MOLD INJECTION * BACKPLANE SOLUTION * CONNECTORS The information contained in this communication including any attachments is intended solely for the use of the individual or entity to whom it is addressed and others authorized to receive it. This communication may contain information that is privileged, confidential and exempt from disclosure under applicable law. If you are not the intended recipient you are hereby notified that any disclosure, copying, distribution or taking any action in reliance on the contents of this information is strictly prohibited and may be unlawful. If you have received this communication in error, please notify us immediately by responding to this email and then delete it from your system. No printed copies should be made or retained. Thank you. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Frank Kimmey Sent: Tuesday, November 21, 2006 12:10 PM To: [log in to unmask] Subject: Re: [TN] Acid Traps John, In todays world, if a PCB is properly cleaned after etch, deposition and prior to mask, then acid traps should not be a concern. We do a lot of weird angle stuff in the RF world and I have never seen a failure due to acid trap type issues. Bottom line is if your fabricator has good process then it should not be an issue, but to keep risk to a minimum good design practice should be followed when possible. Hope it helps, FNK Frank N Kimmey CID+ Principal PCB Designer PCB Programs Powerwave Technologies Inc Office 916-941-3159 Fax 916-941-3195 Mobile 916-670-0645 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of John Foster Sent: Tuesday, November 21, 2006 8:53 AM To: [log in to unmask] Subject: [TN] Acid Traps I would like to ask the board fabricators if acid traps are a real issue. I normally try to avoid any feature that creates a structure that is less then 90 degrees. However I am helping out another group by reviewing their boards and there are literally hundreds of acid traps on the board. This board is class 3 and has to be high reliability. I have always been taught that they can be a real problem. But have never quite understood why. Any input on this will really be appreciated. Thanks John Foster --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 1.8e 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 1.8e 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 -----------------------------------------------------