Kenny, Since most heating is done during contact with the wave, increase contact-time is more effective than adjusting preheat or flux. In addition to increasing the wave height you could also decrease conveyorspeed. I assume your solder temperature is already somewhere around 250 degrees Celcius ? Daan Terstegge Unclassified >>> Kenny Bloomquist <[log in to unmask]> 10/19 2:53 pm >>> Hi All, I have an assembly that is a build to print so I have no control over the design. My problem is that it's a ten-layer board with the ground pin of every I/C tied to about four internal planes with no thermal relief around the holes. As you might guess I am not getting any flow through to the top of the board. In fact, it's probably not even 50%. I have tried increasing the topside pre-heat, topside fluxing and increased wave height. None of this has shown any improvement. I'm looking for any other suggestions, besides redesigning the board, that might resolve this problem. Thanks in advance for your suggestions. Ken Bloomquist Sr. Principal Process Engineer PRIMEX Aerospace Company P.O. Box 97009 Redmond, WA 98073-9709 http://www.primextech.com Ph: 425-885-5000 FAX: 425-882-5786 [log in to unmask] Northcon/2000, Chairman of the Board http://www.northcon.org Electronics Manufacturers Association (EMA), Vice President http://www.ema-wa.org ############################################################## 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 ##############################################################