Put solder mask on the via pads (or plug them from the solder side). They will never fill, so cannot short. Of course, not all customers will allow this. If you can do this, you don't have to worry about design limits or change process settings. It's much easier to design this out than to pull other process parameters out of optimization or unnecessarily constrain the design staff. Aric Parr ______________________________ Reply Separator _________________________________ Subject: [TN] Assy:Min distance between vias in wavesoldering Author: Johannes Sivula <[log in to unmask]> at INTERNET