> What kind of hole-fill did you get? The hole (barrel) was completely > filled with solder from the top to the bottom side of the PCB (.062" > thick), and there was good wetting up the sides of the connector pin on > both sides as well. The through-hole connector has square leads that are > .0155" thick. The hole size on the PCB is .036". The stencil has .0915" > oblong apertures and is .006" thick (due to fine pitch parts on the > board). When I set-up the screen print process I used a slow squeegee > stroke (20mm/sec), and extra squeegee pressure (instead of 7kg/in for a > 14" blade 9kg/in.) in order to force more solder into the hole. When the > connector (lead length .0885") is installed the lead protrusion on the > back side is only about .025" (+/-.001). The solder fillet on the top and bottom of the board was 360 degree solder fillet all the way around the lead with excellent wetting characteristics up all sides of the connector pin. I had no solder balling issues. The hard part was installing the through hole connectors without disturbing the fine pitch surface mount devices that were already placed. This particular through hole connector has guide pins that snap into place and if the PCB was not supported correctly during the connector installation process then the fine pitch devices shifted and we had misalignment problems. Once proper board support was provided this problem was eliminated. I do agree with the other gentleman who mentioned that a small lead protrusion on the back side of the board is critical in order for PIH to work, but I am not sure where that cut off point would be. All of the boards I have set-up for PIH have the same lead length/lead protrusion, and our process has always worked without a glitch. This could explain my false sense of euphoria. Hope this helps. Thanks, Kathy Palumbo > ---------- > From: Yves Trudell[SMTP:[log in to unmask]] > Sent: Friday, April 10, 1998 8:29 AM > To: [log in to unmask] > Subject: PIH > > Kathy, I read your note on the TechNet. You mentioned that you had good > wetting on both sides when you used paste-in-hole. What kind of hole-fill > did you get? That is, was all of the barrel filled with solder, where > solder > wicked to the tip of the pin on the back side of your pcba? When we > switched to PIH, that was one of our concerns, barely being able to see > the > solder from the bottom side of the pcba, which fought against too much > paste > on the topside which ran the risk of top-side solder balls. > ################################################################ TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################