Pete, This is a great starting point for issues I'm seeing in our process too. Thanks, Phil Nutting -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Pete Houwen Sent: Wednesday, October 29, 2008 9:07 AM To: [log in to unmask] Subject: Re: [TN] How to improve solder filling and wetting contact angles for thermal vias at wave soldering process. We did some testing of design parameters when we switched to lead-free, and found that the lead-hole ratio is more critical. We also found that top side pad size is irrelevant for hole fill, but large bottom side pads can adversly affect hole fill. Using this chart, we are able to achieve 75% with regularity (and we do not have the best process controls in our plant): Lead Range Pad Size Hole Size .000-.017 0.05 0.026 .018-.022 0.06 0.035 .023-.027 0.07 0.04 .028-.032 0.07 0.046 .033-.042 0.08 0.052 .043-.052 0.09 0.062 .053-.063 0.1 0.073 .064-.076 0.11 0.086 .077-.086 0.12 0.096 .087-.106 0.14 0.116 .107-.115 0.15 0.125 (dimensions in inches) standard plane connects are thermal relief, using (4) .008" spokes. This testing was done only to establish design parameters, there are plenty of process parameters that will affect hole fill. But if your design parameters aren't good, all the process tweaks in the world won't fix trhe problem. --------------------------------------------------- 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 ----------------------------------------------------- Note: All the information contained in this e-mail and its attachments is proprietary to Kaiser Systems, Inc. and it may not be reproduced without the prior written permission of sender. If you have received this email in error, please immediately return it to sender and delete the copy you received. --------------------------------------------------- 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 -----------------------------------------------------