lee, Can you provide us the paper you have mentioned in your mail for the barrel to copper. Please provide me your mail id so that i can correspond with you on this further. Thanks in advance for your reply. Regards suresh Dehoyos, Ramon wrote at Thu Apr 12 18:04:28 GMT+05:30 2007: > > Lee: > Good to know info. ^ current density, ^ brittleness, v plating >uniformity and density. Good things take time. > Thanks, > Ramon > >-----Original Message----- >From: TechNet [mailto:[log in to unmask]] On Behalf Of Lee parker >Sent: Wednesday, April 11, 2007 12:42 PM >To: [log in to unmask] >Subject: Re: [TN] Via hole plating corner crack > >Victor > >You mentioned that the current density is 30 amps per square foot. I >consider this to be extremely high and not only will cause brittle >copper, but highly non-uniform copper in the barrel. I presented a paper >at Apex that mathematically modeled the copper uniformity in the barrel >to the plating parameters including current density, you might want to >review this paper. The model shows there is an inverse linear dependence >between the copper uniformity and the plating density. >Best regards > >Lee > >J. Lee Parker, Ph.D. >JLP Consultants LLC >804 779 3389 >----- Original Message ----- >From: "Victor G. Hernandez" <[log in to unmask]> >To: <[log in to unmask]> >Sent: Tuesday, April 10, 2007 10:36 AM >Subject: Re: [TN] Via hole plating corner crack > > > Can you please post the crack via cross section photo for viewing, "a >picture is worth one thousands words". Is this SnPb or LF? > >-----Original Message----- >From: TechNet [mailto:[log in to unmask]] On Behalf Of C J Long >Sent: Tuesday, April 10, 2007 9:20 AM >To: [log in to unmask] >Subject: [TN] Via hole plating corner crack > >Dear Techneter: > >I recently experienced customer return of corner crack. The PCB is 50 >mil >thick, 10 mil via, OSP finish and corner crack is over the 4 corners of >top >and bottom >of hole. Crack is started from the bottom of external foil and crack >through > >the entire plating. You can see the photo (file: crack through) of >actual >failure. Plating is unusual column type crystal on the surface. In the >hole >barrel, the plating crystal is regular. We also performed many in-procss >WIP > >cross section (refer to the file "crack 9X IR") and we could only find >the >crack after 6X IR reflow and its crack is started from external foil top >corner. I have sucessfuly duplicated similar failire with very high >plating >current density of 30ASF with very low brighter (0.15cc/l), but its >failure >mode is crack on ehe top of external foil not the same as customer >return. > My questions are: > >1. Are these two failre modes with the same root cause? What is the >reason >one crack is started from the foil top corner and the other is from the >bottom? >2.Is there any non-destructive method able screening the cracked >plating? > > >http://tw.pg.photos.yahoo.com/ph/minalong2003/album?.dir=/5c32scd > >Thank you very much. > >--------------------------------------------------- >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 >----------------------------------------------------- > >--------------------------------------------------- >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 >----------------------------------------------------- > > >!-- Virus-Free Mail Using AntiVirus for IQ Mail & QuickHeal Engine --! > -- Thanks in advance for your reply. Regards T.Suresh Babu Asst.Manager-Development. Plot No.16,Jigani Indl Area, Anekal Taluk Micropack Ltd., Bangalore 562106 Ph-091-80-27825223/27826422 Fax:091-80-27825225 Email: [log in to unmask] ------------------------------- Micropack Ltd, Bangalore, India !-- Virus-Free Mail Using AntiVirus for IQ Mail & QuickHeal Engine --! --------------------------------------------------- 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 -----------------------------------------------------