Positive layers are typically used to walk pure lines, including outer and inner layers. The negative layer is mostly used for the formation and power layers. Because in the multi-layer board, the ground layer and the power layer generally use the whole piece of copper as the line (or as several large block division areas). If you use MIDLAYER or the positive layer to draw, you must use copper plating. Implementation, this will make the entire design data volume is very large, is not conducive to data exchange, and will affect the design refresh rate. With a negative film, it is only necessary to create a flower hole (THERMAL PAD) at the joint between the outer layer and the inner layer, which is very advantageous for design and data transfer.
1. Inner layer addition and deletion
In a design, sometimes you encounter a transition plate layer. For example, changing a more complicated double panel to a four-layer board, or upgrading a four-layer board with a higher signal requirement to a six-layer board, and the like. In this case, you need to add an electrical layer, you can do the following:
DESIGN-LAYER STACK MANAGER has a schematic diagram of the current stack structure on the left. Click on a layer above the new layer location, such as TOP, and then click on the right ADD LAYER or ADD PLANE to complete the new layer addition.
Note that if you add a layer to make the PLANE layer, you must assign the corresponding layer to the new layer (double-click the layer name)! There can only be one network allocated here (the general layer can be assigned a GND), if you want To add a new network in this layer (such as the power layer), you need to do inner layer splitting in the later operation to reach it, so here you can allocate a network with a large number of connections.
If you click ADD LAYER, a new MIDLAYER will be added, and the application method is exactly the same as the outer layer.
If you want to apply a hybrid electrical layer, that is, a large copper surface method with both trace and power supply, you must use ADD LAYER to create a positive layer to design.
2. Internal electric layer segmentation
There are two large copper electrical connections in PROTEL (excluding PLACE FILL), one is POLYGON PLANE, which is ordinary copper. This command can only be applied to the positive layer, including TOPBOTMIDLAYER, and the other is SPLIT PLANE. Electrical layer splitting, this command can only be applied to the negative layer, INTERNAL PLANE. Care should be taken to distinguish between the two command usage ranges.
Modify the split copper command: EDIT-MOVE-SPLIT PLANE VERTICES
One more caveat here is that if there is more than one set of power supplies in the design, then the inner layer split can be used in the power plane to distribute the power network. The command to use here is:
PLACE-SPLIT PLANE, set the layer in the dialog box, and specify the partition to be assigned to the network at CONNECT TO NET, and then place the partition according to the copper method. After the placement is completed, the corresponding network hole in this split area will automatically generate the flower hole pad, which completes the power layer electrical connection. This step can be repeated until all power is allocated. When the internal electrical layer needs to allocate more networks, it is more troublesome to do inner layer segmentation, and some techniques are needed to complete it.