Hi Jeff, You've probably read almost all articles but I'll post this link anyway. http://www.circuitsassembly.com/pdf/0301/0301raytheon.pdf
I've done a lot of BGA designs but never had that problem. Have you ever thought of changing the PCB manufacturer and/or the assembly house? Mira --- Jeff Condit <[EMAIL PROTECTED]> wrote: > We have done BGAs for a while. About a year ago we > were struck with black > pad. Firstly, I can't help wondering if there is > some connection, directly > or indirectly, with the RoHS-mandated changes. ENIG > has been around for a > while, but was not in as prevalent usage. And the > specs surrounding how to > do it reliably seem to be in a state of flux. > Secondly, it preferentially > attacks specific pads repeatedly on multiple boards, > while rarely attacking > adjacent pads of the same size and shape on the same > boards. This implies a > dependency on how the board is designed, which means > I want to know how to > make it stop if I can. We had two different PCB > designs in the same product > using the same layer stackup, layer thicknesses, > trace widths and spacing, > BGA pitch, plane structure, processes, etc. They > were both fabricated by > the same fabrication house and assembled by the same > assembly house in the > same general timeframe. Black Pad hit multiple pads > on nearly every board > of one design over both runs, but never hit any pads > of any board of the > other design over both runs. I find that > interesting. > > I wonder what other problems will shake out in the > next couple years. > > Jeff > > ----- Original Message ----- > From: <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]>; <[email protected]> > Sent: Monday, August 13, 2007 1:56 PM > Subject: RE: [PEDA] Black Pad > > > > So... what do you find so interesting about the > issue, Jeff? > > > > Has there been a technical detail that's been > found recently to bring > > the question into more focus for board houses > and/or their customers? Or > > perhaps it's something else? > > > > Regards, > > > > aj > > > >>-----Original Message----- > >>From: [EMAIL PROTECTED] > >>[mailto:[EMAIL PROTECTED] On Behalf Of > Jeff Condit > >>Sent: Sunday, August 12, 2007 8:08 PM > >>To: Protel EDA Forum > >>Subject: [PEDA] Black Pad > >> > >>Are you all familiar with "Black Pad"? I've been > looking into > >>it and its interesting. > >> > >>Jeff > >> > >>____________________________________________________________ > >>You are subscribed to the PEDA discussion forum > >> > >>To Post messages: > >>mailto:[email protected] > >> > >>Unsubscribe and Other Options: > >>http://techservinc.com/mailman/listinfo/peda_techservinc.com > >> > >>Browse or Search Old Archives (2001-2004): > >>http://www.mail-archive.com/[EMAIL PROTECTED] > >> > >>Browse or Search Current Archives (2004-Current): > >>http://www.mail-archive.com/[email protected] > >> > >> > > > > > > This e-mail transmission and its attachments may > contain information from > > Avtron Manufacturing, Inc. that is proprietary, > privileged and/or > > confidential and is intended exclusively for the > person(s) to whom it is > > addressed. Any use, copying, retention or > disclosure by any person other > > than the intended recipient or the intended > recipient's designees is > > strictly prohibited. If you have received this > message in error, please > > notify the sender immediately by return e-mail and > delete all copies. > > > > > > > > -- > > No virus found in this incoming message. > > Checked by AVG. > > Version: 7.5.483 / Virus Database: 269.11.17/951 - > Release Date: 8/13/2007 > > 10:15 AM > > > > > > > > ____________________________________________________________ > You are subscribed to the PEDA discussion forum > > To Post messages: > mailto:[email protected] > > Unsubscribe and Other Options: > http://techservinc.com/mailman/listinfo/peda_techservinc.com > > Browse or Search Old Archives (2001-2004): > http://www.mail-archive.com/[EMAIL PROTECTED] > > Browse or Search Current Archives (2004-Current): > http://www.mail-archive.com/[email protected] > > ____________________________________________________________________________________ Fussy? Opinionated? Impossible to please? Perfect. Join Yahoo!'s user panel and lay it on us. http://surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7 ____________________________________________________________ You are subscribed to the PEDA discussion forum To Post messages: mailto:[email protected] Unsubscribe and Other Options: http://techservinc.com/mailman/listinfo/peda_techservinc.com Browse or Search Old Archives (2001-2004): http://www.mail-archive.com/[EMAIL PROTECTED] Browse or Search Current Archives (2004-Current): http://www.mail-archive.com/[email protected]
