A layout engineer who studies signal integrity simulation
last time shared with you the operation of replacing vias in Allegro. In PCB design, in addition to routing and vias, there is another important command is shape. Shape is what we call copper skin operation. Shape contains many commands, which also simplifies our design and makes it more convenient for us to operate in layout. However, sometimes it is more complicated to deal with shape, such as cutting the copper skin. Dig copper and so on. Today, I will briefly talk about the basic operations of shape:
Step 1: Add shape
Select the shape command under the menu bar of Allegro, open the shape command, and you can see that the first three are commands for adding shape, which are arbitrary shape, rectangle, and circle. Or directly click the Add shape operation on the shortcut toolbar. After we select the command, or the dialog box in the lower right corner pops up, the upper column is the layer we want to add shape to, and the lower column is if we add it to the wiring layer, we need to assign a network to the copper skin, otherwise the default For Dummy Net. As shown below:
The second step: Copper skin type conversion:
There are two commonly used copper skin types: the first is static copper skin (Static solid); the second is dynamic copper skin (Dynamic copper), and the dynamic one can avoid our wiring punching in real time. What is static cannot be avoided. If the board we design is more complicated, the static copper skin can reduce software lag, and the dynamic copper skin is real-time avoidance, which will increase the processing time of the software. When designing again, you can look at your own choices. First of all, we can choose the type of copper skin when we add the copper skin, as shown in the figure below:
We first choose to draw a dynamic copper skin, then right-click and select assgin net to assign the copper skin network, and by the way, click a desired copper skin network pin, shape, and via are all fine, and then adding copper skin is a shape with net, as shown in the following figure:
we select the copper skin command in the menu bar, click shape, and right click to pop up the following dialog box, select the charge shape type, it will change the dynamic copper skin to static (or static to dynamic), as shown in the figure below:
The third step: copy copper skin
When we are in the multi-layer board, we need to lay the ground on each layer. At this time, it is too troublesome for us to add copper skin to each layer. There is a simple method that we first draw a copper sheet on the ground layer, then right-click and select copy to layers, the following dialog box will pop up, select the class and subclass we want to copy, and tick the following keep dynamic and keep network. In this way, you can see that the other layers are also covered with copper skin, as shown in the following figure:
Step 4: merge copper skin
This function is when you have two copper skins overlapping. Or on the basis of the revision, if you want to expand the area of the copper skin, draw a new piece, and if there is an intersection, you can use this function to combine them together. Select merge in the shape toolbar, and then click the copper skins you want to merge together, as shown in the figure below:
Previous article: Cadence Allegro PCB Design 88 Question Analysis (15) How to replace the via type in Allegro The link is as follows, you can click to view it: link
The above information is mainly compiled by myself in PCB design and Internet search
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