Planarity within a component with HASL S/B .001" maximum - target condition is around .4 mils (speaking horizontal HASL). Immersion silver or tin will provide planarity less than .1 mils. Jeffrey Bush Director, Quality Assurance and Technical Support 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302-1890 Tel. 802.257.4571.21 Fax. 802.257.0011 [log in to unmask] http://www.vtcircuits.com -----Original Message----- From: Dacia Super [mailto:[log in to unmask]] Sent: Friday, October 08, 2004 7:12 PM To: [log in to unmask] Subject: [TN] Coplanarity All - I have a question related to surface mount component coplanarity. Is there a set +/- "window of opportunity" that surface mount gull-wing leads are allowed to fall within? Is this covered in a standard anywhere? I looked into IPC-A-610 and J-Std - and I found information related to "toe down" configuration but I did not see any information related to "toe up" configuration. I also referenced JESD22 Method B 108. Interesting guideline - using the seating place method as a measure of determining coplanarity deviation. So, if I am understanding this test method properly, the user (meaning the manufacturer trying to build with the darn thing) defines the +/- window? Background info: Qualifying new board. One part on the board is a large transformer with gull wing leads - 24 leads on either side of the component. We are frequently seeing leads bent upwards (towards the heavens) and this is obviously creating manufacturing frustrations. However, vendor is indicating a +/- window of 4 mils - either side. Doesn't that seem large? That would be a total of 8 mils of variation..... So, I was just wondering if there was a criteria out there that we could reference, to determine whether or not these parts are really acceptable. Appreciate the help. - D --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 847-509-9700 ext.5315 -----------------------------------------------------