Applied Parameters: None
This command is used to add a venting pattern to the current panelized PCB. Venting is used as a means of obtaining a uniform distribution of copper over the entire panel, by placing a copper pattern in the no-copper area of the panel, as defined by the minimum border applied when the panelization was performed. This allows the etching process to be carried out with maximum efficiency.
This command can be accessed from the CAMtastic Editor by:
- Choosing the Tools » Venting command from the main menus.
- Clicking the button, on the Fabrication Tools drop-down () of the Utilities toolbar.
The use of this command will depend on whether or not you kept the vent_border layer when the PCB was panelized.
With a vent_border layer present
After launching the command, the Venting dialog will appear. By default, all signal and plane layers will be selected for venting. To deselect a layer, simply click on its entry.
The left-hand side of the dialog shows the currently defined venting pattern that will be applied. Click on the Edit Pattern button to open the Edit Pattern - Venting dialog, from where you can define the specific venting pattern you wish to use.
After defining the venting pattern and layers to be vented as required, clicking OK will apply the venting pattern to the panel, in all areas outside of the vent_border.
With no vent_border layer present
Without a vent_border layer, the panel border will still exist, but the individual PCBs on the panel will have no boundary by which to calculate the area for venting. You will therefore need to add borders to each of the PCBs on the panel, essentially creating your own vent_border layer. Adding a new layer and using the polyline command to draw boundaries around each PCB on the panel is one of the fastest ways to achieve this.
After launching the command, the cursor will change to a small square and you will be prompted to select the panel and PCB borders. Simply drag a selection box around the entire panel. All PCB borders and the panel border will now be selected. Right-click - the Venting dialog will appear. Define the venting pattern and layers to be vented as required and then click OK. The venting pattern will be applied to the panel, in the area defined between the panel and PCB borders.
- Use the Edit Pattern - Venting dialog to define the venting pattern as required. If the Fill Type is set to Polygon (Raster), then all other settings in this dialog will be disabled. The panel border will be filled with a solid polygon pattern.
- If the Fill Type is set to Vector, you may choose between using a solid image or a shape/Dcode. You can choose a shape and enter a size to use for the fill, or you can specify to use an existing aperture. If you have chosen to use Shape/Dcode, you can specify the XY spacing of the shape used.
- Using a polygon pattern will cause two new Dcodes to be added to your apertures list. These appear as the entries Poex and Poin.
- If you use shapes and sizes for vector patterns that are not existing apertures, they will be added to the apertures list with the next available Dcode.