We have been soldering LED boards together for years with no issues. Recently engineering has gone to a new board design and we got the first samples in this week. Because of the improved design and better heat dissipation of the board my team is have great difficulty soldering lead wires and connecting boards in series with wire to the solder pads on the LED boards.
The solder will not stay molten long enough to insert a wire even with the soldering tip still in direct contact with the solder pad. I have tried different temperatures and methods but all have resulted in failed solder joints.
Looking for any advice on methods/ materials to try out.
We are currently using Kester lead free 275 .062 wire at 625 degrees