Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Bill D.

#15243

PCB Panel Warp | 25 June, 1998

I have a 2-up panel measuring about 8" x 8" with a score for depanel throuch the middle. I see warping after reflow of the panel (bending in/about score line). The board is not framed (i.e., supported) during SMT reflow other than on the conveyor thru the reflow. Will this caused me difficulties in soldering fine pitch (<20 mil) packages?

reply »

David S.

#15244

Re: PCB Panel Warp | 26 June, 1998

| I have a 2-up panel measuring about 8" x 8" with a score for depanel throuch the middle. I see warping after reflow of the panel (bending in/about score line). The board is not framed (i.e., supported) during SMT reflow other than on the conveyor thru the reflow. Will this caused me difficulties in soldering fine pitch (<20 mil) packages? Yes, this could be a problem especially with bigger packages (208 and 240 pin QFP). One suggestion is to place the CCA directly on the mesh chain if your reflow oven has such a chain.

reply »

Michael Fogel

#15245

Re: PCB Panel Warp | 30 June, 1998

| | I have a 2-up panel measuring about 8" x 8" with a score for depanel throuch the middle. I see warping after reflow of the panel (bending in/about score line). The board is not framed (i.e., supported) during SMT reflow other than on the conveyor thru the reflow. Will this caused me difficulties in soldering fine pitch (<20 mil) packages? | Yes, this could be a problem especially with bigger packages (208 and 240 pin QFP). One suggestion is to place the CCA directly on the mesh chain if your reflow oven has such a chain. Bill, In my opinion you should re-design the PCB panel by adding a front/rear support beam. This should add some more strength to the panel during the reflow process. Rgds. Michael

reply »

Reflow Ovens thermal process improvement