Netlist Extraction (Part 1)

Up to this point all the effort has been to make the settings required for CAM350 to operate on the database. But before that can happen there are 2 more operations that must be performed on the database itself to prepare it for netlist extraction.

1. If there are areas of Poured Copper on the outer layers you may need to Convert Draws to Raster Polygons before a netlist can be successfully extracted.

First, try extracting the netlist without taking this step. The file has been saved to this point so skip to step 2 (convert draws to flashes) and then go on to extract the netlist. 
If netlist extraction is not successful reload the last saved version and Convert Draws to Raster Polygons as follows:

Select Utilities/Polygon Conversion > Draw To Raster Poly.

The Command Status prompts for a selection or window.

Do Not use a window to define the area to be processed if that area will also include traces. Only areas of copper flood should be selected. Objects will become highlighted as they are selected. If there are a large number of polygons, consider creating a separate layer for just the copper. Perform the conversion then copy the copper to the correct associated layer.


When the instances of polygon have been selected, click the RMB to begin the conversion process. A dialog box will appear. Click OK with the LMB to start conversion.

When the Command Status display prompts for a selection again the process is complete.

Terminate the command by clicking the RMB.


The next blog post will show a demonstration of the Draw to Raster Poly command.

Layer Sets (for Blind and Buried Vias) - LAB

Select Tables/Layer Sets > Blind and Buried pull down menu option.


Click on the Thru Drill button and select CAM_DemoNC1-6.D from the Layer List window.


Change the Name entry to LyrSet_1-4.


Click on number “1” from the list with the LMB. 
Add CAM_DemoL1.PHO to the list. 
Do the same for numbers 2, 3, & 4 with CAM_DemoL2, L3 &, L4.PHO respectively.


Click on the Drill Data button with the LMB to pop up the layer list. 
Click on the appropriate layer with the LMB to andselect CAM_DemoNC1-4.D from the Layer List window.


Click the Add button with LMB to create a new layer set name.


Change the Name entry to LyrSet_3-4.


Click on number “1” from the list with the LMB. 
Add CAM_DemoL3.PHO to the list. 
Add CAM_DemoL4.PHO to number 2.


Click on the Drill Data button with the LMB to pop up the layer list. 
Click on the appropriate layer with the LMB to andselect CAM_DemoNC3-4.D from the Layer List window.


Save your work now using File/Save.

Layer Sets (for Blind and Buried Vias) - Video

Watch this video to view a demonstration of the Layer Set operation for Blind and Buried Vias:

Layer Sets (for Blind and Buried Vias)

When Blind and Buried vias are used in a design CAM350 must be instructed as to the relationships between the Drill Tables and the layers they are associated with. A Layer Set Table is used for this purpose.


The layer set table is accessed from the Tables/Layer Sets > Blind and Buried pull down menu option.

Click on the Thru Drill button to pop up a Layer List window.


Select the layer associated with the final stage (through) drill using the LMB 
(in this case “CAM_DemoNC1-6.D”).

Set up the table for the fist (blind) layer set as follows:
1. Change the Name entry to reflect the layer set (1-4)


2. Click on a number from the list with the LMB. A Layer List window will pop up. 
     Click on a layer from the list that is to be added in the numbered layer position. 
     In the following example we can see that layers 1 and two have already been selected.    
     Adding CAM_DemoL4.PHO will complete the Blind layer set.

3. The drill data for this layer set is added in the same manner as for the thru drill. 
     Click on the Drill Data button with the LMB to pop up the layer list. 
     Click on the appropriate layer with the LMB to select it .

Set up the table for the second (buried) layer set as follows:
1. Change the Name entry to reflect the layer set (3-4)


2. Click on a number from the list with the LMB. A Layer List window will pop up. 
     Click on a layer from the list that is to be added in the numbered layer position. 
     In the following example we can see that layers 3 has already been selected. 
     Adding CAM_DemoL4.PHO will complete the Buried layer set.

3. The drill data for this layer set is added in the same manner as for the thru drill. 
     Click on the Drill Data button with the LMB to pop up the layer list. 
     Click on the appropriate layer with the LMB to select it .

This completes the Layer Set setup.

NC Tool Table - LAB

Before proceeding with this step note the relative sizes of the “holes” in the Work Area display on the NC Drill layers (14,15 & 16)


Open NC Tool Table from the Tables pull down menu.


First, set the units to Millimeters. 
(Note that the Size column still indicates Mil – disregard)


Enter the Drill Sizes and Usage into the table. 
Refer to the layer definitions in the Readme text file in the Gerber file directory for drill tool sizes and plating.


Use the Tool Table pull down menu to change between Tables for the 3 Drill layers.


Click OK to exit the NC Tool Table menu.


What does the Work Area display for layers 14 15 & 16 look like now?


Save your work using File/Save.

NC Tool Table - Video

Watch a demonstration of the PADS Drill Macro here:

NC Tool Table

The NC Tool Table contains drill sizes.
Get to the NC tool table from the Tables pull down menu.

There will be a Tool Table that corresponds to each NC Drill layer.
This happens automatically when the files are auto-imported.

In this case there is a table for each layer set. (drill pair).



To enter drill sizes in a table:

1. Select the desired table from the Tool Table pull down menu.
2. Set the units as desired.
3. Enter the drill size in the Size column (Note that the column headingremains as Mils even though millimeters are set as Dialog units).Refer to the Drill Report for the drill tool sizes.
4. Set the Usage checkbox to indicate holes are Plated or Unplated. 
5. Do steps 1 through 3 for each drill set table.

For PowerPCB and Allegro users there are also macros available that will automatically load the Tool Table. The macro will not, however, work with multiple drill sets.

Instead of entering the NC drill sizes manually as described earlier in this section use the Macro pull-down menu to select and run the Pads Drill macro.

The next blog post will demonstrate the use of the Pads drill macro.