When converting MAC-PC layouts it is important to consider the following points:-

The pad sizes are not stored in the individual layer Gerber file, instead they are in aperture file(s).

Power planes are generated by the fabricator combining two separate Gerber files. Usually one file will have a Pickering drawing box with the layer name i.e. “top inner” and the second file will contain only the PCB image. Please note that the second file will be a negative image i.e. where there are lines etc there is no copper.

The Gerber and aperture files do not have an extension, it is not necessary to rename them but you will need to browse for *.* when looking for files to be imported into Camtastic.

There may be more than one aperture file for a PCB design. The layers the aperture file relates to are normally specified in the quote request document. Alternately the “tool#” in the aperture file may match the name of the Gerber image file.

In the aperture file there can be multiple copies of the pad shape information (“D codes”), each set has a header in the format “APERTURE TABLE For {PCB reference} G-comps : Tool# 2” where each “tool” in a separate layer. For example if there are sets titled “Tool#1 – 6“ then the aperture file relates to six layers.

The aperture files are not directly compatible with Altium but they can be imported using the Aperture List Wizard and a file produced by Pickering. The file is called MACPC.awr and should be copied to the “c:\Program Files\{Altium Version}\System\aptwiz” folder (note:- path will depend on the installation location of Altium).

In order to follow the conversion process you will need the following files:-