Ken, Reflow pad width no wider than nominal chip width, pad length 1 mm, pad separation 1 mm or pad ctr to ctr dimension 2 mm or nominal chip length. Stencil thickness should be 4-5 mils and a home plate stencil should be used to minimize any solder balls during reflow soldering. Wave solder pad width should be 1/2 to 2/3 nominal chip width and extend beyond the chip end 1 1/2 time chip thickness. John >John, > >Not being a board designer, what is the recommended pad size and geometry >for a ceramic 0805? > >Thanks, > >KennyB > >-----Original Message----- >From: John Maxwell [mailto:[log in to unmask]] >Sent: Monday, April 28, 2008 3:04 PM >To: TechNet E-Mail Forum; Ken Bloomquist >Subject: Re: [TN] Cracking Ceramic Cap > >Ken, >Boy this take me back to my capacitor cracking days. It will be nice to >see what the failures look like but from what has been described is >consistent with assembly flexure cracking. When I wrote my first paper >on MLCC crack signatures the great majority of cracks were due to >assembly handling followed closely be excessive solder joint size. >Things have not changed in the intervening 20+ years. Big wide solder >joints and a connector right next door, the perfect recipe for cracks. > >John Maxwell > > > >--------------------------------------------------- >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 -----------------------------------------------------