User Guide

Check once more whether all the necessary layers for the creation of the
aperture table are active in the first section. The output file generated in
the first section cannot be used. For this reason, the file name.$$$
shouldbedeleted.
Layers that refer to the bottom side of your layout will be generated
mirrored in all predefined job files. If your board house recommends
non-mirroredfiles,pleasedeactivatethisflagoptionforeachsection.
If you want to generate output files for supply layers with one signal
(here $GND), you must only select the inner signal layer. No pads, no
vias!
For other inner layers that may contain polygons you have to select ad
-
ditional pads and vias layers (as you would also do for the top or bottom
side).
9.8 GerberFilesfor Photoplotterswith Fixed
Aperture Wheels
This section goes into more detail on the definition of the aperture
table. Some circuit board manufacturers may perhaps still be using a
Gerber plotter that works with a fixed aperture wheel. In such a case it is
necessary to adapt the aperture table to the restricted facilities of the
Gerber plotter. Files for Gerber photoplotters with fixed aperture
wheels are generated with the GERBER driver. It is essential to confer
with your photoplot service bureau in good time, so as to adjust
EAGLEtotheavailableapertures.
There are various types of apertures. They differ in size and shape. The
most common are circle, octagon, square, thermal and annulus symbols.
Thedrawingapertureusedfortracksisnormallytheroundaperture.
You must specify the aperture configuration before you can generate
filesforafixedaperturewheelphotoplotter.
To do this, enter the configuration file for apertures name.whl e.g. with
the EAGLE text editor, and then load this file into the CAM Processor
by clicking the Wheel button after selecting the GERBER device driver
(seealsothe SetOutputParameters section,page 186).
The CAM Processor normally chooses the aperture from the configura
-
tion file appropriately for each object. For each line, a draw aperture
must be present with the appropriate diameter. For each symbol (e.g.
pad) an aperture with the correct shape and size is required. If this is not
available,nooutputfilewillbeproduced.
191
PreparingtheManufacturingData