Hi Jan- I would suggest taking a look at how/where the shield plated thru holes are connected to the internal board planes. If those plated thru holes are connected to several of the internal planes then you have a heat thieving condition impacting your ability to solder. Check with your design folks and see if there is any possibility of getting some relief or minimization the internal plane connections. You can also look at adding a small amount of solder paste at the shield base to help promote solder filleting - the solder paste will reflow during wave soldering due to the temperatures involved. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: SMD remelt Author: [log in to unmask] at ccmgw1 Date: 4/9/97 3:15 AM Hi all, We have a minor problem at wave soldering shields on 8-layer FR-4. The problem is that we need a very long dwell time (6-8secs) to get the solder to wet all around the shield, it's very critical because it has to be a tight joint. This leads to a high temperature at topside of the board at soldering, and inside the shields we have SMD-ICs which joints reach an temperature to about 209 degC. But then if i raise the preheating temperature and lower the dwell time, the shields won't get this tight joint and misses corners and some long-sides, this cost some to rework. Some additional info: Seho wave solderer, NO-CLEAN flux, We put some extra flux around the shield, we use a chip-wave to get better wetting. Anyone have more ideas? /Jan Merstrand Wave Soldering Technician *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************