CAM350 Tech Tips
Add Polygon Features and Benefits
Add | polygon is a great way to add data to a board with a number of helpful options. Two applications of this that are often overlooked are creating outlines and creating thieving patterns.
First create a new layer. Edit > Layers > Add Layers
This is the layer where your outline will be created. Make your source layer active by selecting it on the layer bar. Select Add | Polygon
The above settings are recommended for most cases. Draw boarder is preferred as select boarder would leave the selected boarder out of the polygon. Outline Dcode is a small round. It will be used to draw the outline. In this case it is a 1 mil round.
Flood (Allow Islands) is used as it will allow the polygon to create outline inside closed shapes. Active layer is turned off and the target layer is set to the new layer that was created for the outline.
Finally the Centerline option is checked. This will cause the center of the outline to run along the edge of all the shapes it is creating an outline around. If you choose not to use this option, in order to create an outline that is edge to edge with the original data, make sure you drop polygon clearance to 0.
Hit OK and draw a box around your data. It does not have to be accurate as you will be deleting it in an upcoming step. It just has to completely box in your data. Use left clicks to create the box. As you do the clicks become vertexes in you shape you are drawing.
Right click and the polygon is created. Make your new layer active to take a look.
Next select Edit > Change > Explode > Vector. Click the “select all” button that appears on the tool bar. Once that is done the data is no longer a polygon, but simple draws. Select Edit > Delete and click on the drawn border to get rid of it...
Thieving (copper balancing)
When you want to add copper to a layer for balancing purposes, add | polygon is also the way to do it. Say for example you wanted to add a thieving pattern for 30 mil squares with 60 mil center to center spacing to this board.
First you need to add a 30 mil Square to the aperture tables. You can do this with Tables | Apertures. Next go to Add | Polygon. Typical settings would be look like this.
Area Fill is used because we want to fill the space inside the border. Vector fill is required, as is Dcode for this type of pattern.
Outline Dcode is not relevant. Flood is used so that any isolated areas will get filled in as well. Each island will become its own vector polygon.
Polygon Clearance of 20 mils is set so that the added squares will avoid existing data by 20 mils.
Once settings are done, select Edit to create our pattern. If you already have .pat files done, you could use open instead.
Edit window settings
Line 1 corresponds to the 1st and 3rd rows in the preview window. Line 2 corresponds to the 2nd and 4th rows in the preview window. Dcode 64 is a 30 mil square that was added to the aperture table earlier. X-Step controls the placement of the Dcode in X. X-Offset allows for staggering of the Dcodes in X. Y-Step controls the placement in Y.
Once you have the settings you want to use, click Save to save this as a .pat file. Then click OK, then OK again to exit the add polygon window. Click anywhere inside the area you want to fill. You will get something like the following.
Note the problem of the fill inside the slot in the center. To remove the extra fill, just use Edit | Delete. In this case it is isolated so it is all one vector polygon. If there is need to remove only part of the fill, you will need to use Edit | Change | Explode | Vector on it first.
To learn more about Add >Polygon, see our help entry.