Connector solder thieves - through hole

I need some input on what good solder thieves dimensions should be. I am limited to solving my bridging problem with solder thieves; all process/wave variables have been adjusted to try to solve this problem. There are several of these connectors on this assembly with parallel and perpendicular orientations.

The PCB is standard FR4, 0.063" thick, HASL, SMT with THT and solder mask. The connectors are 0.100" center to center double rows 16-26 leads. The connectors traveling perpendicular to the board direction are causing the most problems. The leads protrude 0.050" though the board. The annular ring is 0.060" diameter on each hole. Hole size is 0.036".

We are planning 0.180" x 0.060" oval thieves. The copper to copper of the thieves to the connector annular rings is 0.020" with 0.010" mask keep out around all pads.

We have tried a couple variations of thieves with minimal success, none of the previous thieve designs were nearly as long as this. This is about as long as the design will allow. There seems to be little documented research on this issue.

Any input is appreciated.

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