Homebrew PCBs

Another question, this time about the PCB drill files.

 

We are using Protel 99SE and when the NC files are generated the tool number
together with the NC data is in the header of the NC file and there is a
separate file with the a drill table (.DRR).  The drill table again lists
the size and also the plated/non-plated status of each drill size.

 

I am really surprised that the plated /unplated info is not included in the
NC file header similar to the extended Gerber files that are self-contained
with all the aperture info in the header.

 

How is this handled on a practical basis by the PCB houses?  The plated
holes need to be drilled in the bare panel as a first step using part of the
NC file and then after processing finally as the last step the NC file has
to be used again to drill the unplated holes.

 

Do they manually have to split the NC file for the two steps?

Is there software available to automatically split the NC file?

What do other companies and PCB software do?

 

I am trying to standardize as much as possible the PCB process to make it
easy for all parties and with as few chances as possible for creating
errors.

Thanks in advance,

Bertho