Steve, look at www.amp.com/products/technology/articles/dd66c.stm Jim Marsico -----Original Message----- From: Stephen R. Gregory [SMTP:[log in to unmask]] Sent: Thursday, November 11, 1999 2:52 PM To: [log in to unmask] Subject: [TN] Intrusive Reflow Hi ya'll! I'm getting ready to do some intrusive reflow on this board we got here...(this is my first time! I'm s-o-o-o nervous...not really...well, maybe a little...hehehe) Anyways, the parts are going to be 2, 20-pin SIP sockets. The board is .063" thick, the holes are spaced .100" apart, and the hole diameter is .040". I'm trying to decide how big I should make my apertures. I've looked at all the archive postings (there are a 168 of them on intrusive reflow) to see if anybody posted any recommended stencil thicknesses, and/or aperture sizes, but there was none. I looked on the web, but couldn't find any real guidelines either... (hmmmm, something I couldn't find...now THAT's a change!) I need to keep my stencil thickness at 6-mils, 'cause I've got some 20-mil pitch stuff on the same side. I was thinking of doing .060-.070" diameter circles over the holes... does that sound okie-dokie? I did a little test with the SIP socket and a syringe full of solder paste. I drew a bead of paste (about .030" dia.) down the row of holes and dropped the connector in, then reflowed it. Then I got my dremel tool out and did me a rough cross section to check the barrel fill. It actually wasn't too bad...there were about 2-3 holes that were a little shy volume-wise but that was because (I think) the solder wicked over to the holes next to it because of the continuous bead of paste I had laid down. That shoudn't happen when I have individual deposits of paste for each hole. So how big should I make my openings? Did I guess right at .060-.070"? -Steve Gregory- ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ############################################################## ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################