are you also measuring pressfit insertion and extraction force (as a predictor of gas tight joint)? At 08:37 AM 1/17/2006, Ofer Cohen wrote: >Dwight, >I used to send the data as you describe. For the matter effect, the >parameters were extracted from the connectors' data sheets. However, >time after time we received from various manufacturers the request to >give them the final hole diameter and tolerance (+/-2 mils), and the >minimum copper thickness (25 to 50 micron). Hence, to avoid >interactions, we changed the callout to the vendors' request. We are >monitoring the outcome through micro sections. > >Regards >Ofer Cohen >Manager - Quality Assurance and Reliability >SIEMENS COM FN A SB > >-----Original Message----- >From: TechNet [mailto:[log in to unmask]] On Behalf Of Dwight Mattix >Sent: Tuesday, January 17, 2006 17:23 >To: [log in to unmask] >Subject: Re: [TN] Drill and plated hole callouts > >I concur with Werner with the key exception being for pressfit connector >holes. > >Our experience dictates that we specify pressfit holes with >a) manufacturer's exact drill size, (provides the ideal "Goldilocks" >envelope for the needed copper deformation -- not too much to crack >copper, >not too little and not acheive gas tight joint) >b) minimum copper thickness, (we spec 0.0012" min for older 2.5 mm pitch >and 0.001" min for 2.0mm pitch pressfit) and >c) minimum finished hole size (too small will increase insertion forces >overwhelming the insertion press or causing pins to "Z-kink" onto pwb >surface). > >These factors combine to ensure a reliable gas tight joint without >excessive insertion forces or excessive holewall deformation (leading to >post separation or barrel cracking). > >It all starts with using the proper (precise) drill size. The connector >mfg's recommended drill size is the paramount concern. >Ergo, the exception where drilled hole size should be specified. > >my $.02, >dw > > >At 05:41 PM 1/16/2006, Werner Engelmaier wrote: > >Hi Bob, > >The call out of finished hole size is an anachronism left over from the > >through-hole technology era. In modern high-density PCBs you should > >specify the > >drilled hole size (no tolerance) with a minimum plating thickness in >the > >hole to > >be verified by cross-sectiong of coupons. > >The reliability of your vias depends on PCB thickness, drilled hole >size, Cu > >plating thickness, Cu plating quality (verified by testing co-plated >mandrel > >foils for tensile strength and ductiolity--not elongation). Your friend >is > >right, > >electrical test is not enough. You should have coupons either IST or > >HATS-tested. This will be even more important with LF-soldering > >temperatures. You then > >might want to specify not only Tg, but Td and CTE(z) as well. > > > >Regards, > >Werner Engelmaier > >Engelmaier Associates, L.C. > >Electronic Packaging, Interconnection and Reliability Consulting > >7 Jasmine Run > >Ormond Beach, FL 32174 USA > >Phone: 386-437-8747, Fax: 386-437-8737, Cell: 386-316-5904 > >E-mail: [log in to unmask], Website: www.engelmaier.com > > > > > >--------------------------------------------------- > >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 -----------------------------------------------------