Hate to ask, but what is homeplating? John Echols
-----Original Message----- From: Brad Velander [mailto:[EMAIL PROTECTED] Sent: Thursday, January 12, 2006 11:03 AM To: Protel EDA Discussion List Subject: Re: [PEDA] 0402 Land Pattern Steve, My pads are similarly oriented. Typically my pad width matches the chip width. We are homeplating because of excess solderball generation. It is something that became more prevalent recently with current formulations of no-clean (leaded) solder pastes that we were getting. Our screens are anywhere from 5mil to 7 mil thickness depending on the assemblies. We are homeplating all chip components that do not have some form of relief (i.e. SMB or SMC devices, some molded devices have relief areas, troughs, around the contact where the solderpaste is not squished between the contact and the part body) around the pads/contacts. Our SMT people tried a lot of other solutions and consulted with the paste supplier extensively, the only workable solution we found was the homeplating. Of course being a SMT production issue it could have contributing factors from many sources during processing. Sincerely, Brad Velander Senior PCB Designer Northern Airborne Technology #14 - 1925 Kirschner Road, Kelowna, BC, V1Y 4N7. tel (250) 763-2329 ext. 225 fax (250) 762-3374 -----Original Message----- From: Steve Allen [mailto:[EMAIL PROTECTED] Sent: Thursday, January 12, 2006 10:45 AM To: Protel EDA Discussion List Subject: Re: [PEDA] 0402 Land Pattern Brad, Thank you. It looks like my pad might be rotated 90deg from yours. The long side of my pad (0.6mm) is parallel with the long side of the part. Is yours the same? Our manufacturing engineer helped me understand the homeplate process. I'd never encountered it before. He remembers this being more prevalent in the early 90's with IR soldering. Why do you use homeplate? Do you use lead free paste / bare board plating? Do you only use homeplate with 0402's? What's your stencil thickness? Ours is 0.006in thick and paste is applied with with a single blade steel squeege. Thanks again, Steve ____________________________________________________________ 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] ____________________________________________________________ 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]
