Hi Frank,

Your approach is almost identical to what I suggest in my White Paper: 

"Recommendations for PCB FAB Notes and Specifications in Printed Circuit Board 

Drawings for SnPb and Lead-Free Soldering Assemblies, the Qualification of PCB 

Shops and Activities to Assure Continued Quality."

For 'Drilled Hole Size' the drill diameters are specified at 30 mils and 

below and given a refderence values above that; the 'Finished Hole Size' is given 

as a reference for the smaller holes and specified with a =/- 0.003 mils 

tolerance for the larger holes.

For all holes a minimum copper plating thickness is mandated.



Werner







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