I have not got a copy of the fishbone diagram yet but I have some thoughts on what fabrication related defects squeak through the various quality systems and gets to the OEM or end used. Some of the most common PCB defects (associated with the PCB fabricator) that escape to the end users are “latent” defects that are not routinely found by mechanical and visual inspection, microscopic evaluations or electrical testing (continuity or impedance). These are the defects that demonstrate themselves as intermittent opens and increased resistances only after the stresses associated with the thermal excursions inherent in standard (or lead free) assembly and rework cycles. This type of defect can get through the fabricator’s and assembler’s quality system and to the end user. Demonstrated as field failures, these defects include accumulating degradations over time associated with interconnection separation, barrel fatigue/cracks and microvia (MV) failures. One of the most insidious MV failures is one where the microvias come off the capture pad during a heating or cooling cycle but repair themselves at ambient and/or elevated temperatures. Expect shorting and cross talk in association with conductive anodic filament (CAF) formation in response to inner layer and behind the hole wall ionic contaminates and dielectric delamination. Again, this is often a latent defect that demonstrates itself over time with thermal cycling in humid environments. These are defects that can have roots in the fabricators process or practices but not be found until product is in the end use environment. These types of defects can also be caused by various assembly and rework processes and practices where the robustness of the PCB is compromised by high time at temperature excursions, repeated thermal cycles and poor cleaning techniques. These defects are particularly hard to assess, and there is so much opportunity for the proverbial “finger pointing”, that the root cause is often not established. Paul Reid PWB Interconnection Solutions Inc. -----Original Message----- From: Kristopher J. Keating [mailto:[log in to unmask]] Sent: Tuesday, August 17, 2004 2:17 PM To: [log in to unmask] Subject: [TN] Most common PCB failure modes Hello, Could some of you share what are the most common PCB defects that escape to your customers? Thanks Kristopher J. Keating Circuit-Wise, Inc. 400 Sackett Point Rd. North Haven, CT 06473 tel. (203) 281-6511 x 410 fax (203) 287-8409 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Ingemar Hernefjord (KC/EMW) Sent: Tuesday, August 17, 2004 3:16 AM To: [log in to unmask] Subject: Re: [TN] thin film Seal Science say they have it all: http://www.sealscience.com/html/products/VacuumCupsPdfs/15about.pdf ultrahighvacuum guys use pure gold gaskets: http://www.sisweb.com/catalog/F39.pdf ourselves, we use as simple as butyl rubber: http://www.allstategasket.com/materials.asp (not Ultravacuum, of course) Butyl rubber group includes ordinary rubber used in your mountainbike tire, can keep vacuum or pressure for very long time. /Ingemar -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Crepeau, Phil Sent: den 17 augusti 2004 02:25 To: [log in to unmask] Subject: Re: [TN] thin film hi, i believe you should be able to use a gasket material such as viton. phil -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Douglas O. Pauls Sent: Monday, August 16, 2004 2:02 PM To: [log in to unmask] Subject: [TN] thin film Good day all, I am in need of a recommendation for a thin film sealant material. I need it to be 15-20 mils thick, cuttable, and preferrably non silicone. We have considered the Sil-Pad technology, but as this will be used in a vacuum seal operation, I am concerned about silicone outgassing or cross contamination. Are there any thin gasket materials from the engineered rubbers that anyone would recommend? Doug Pauls --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- -- Incoming mail is certified Virus Free. 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Version: 7.0.262 / Virus Database: 264.6.3 - Release Date: 8/16/2004 --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------