# Altium: PCB routing

I have several questions:

1. I'm not sure how to deal with grounds or Vcc when routing. So I have capacitors/resistors connected to the Vcc of the FPGA, so I connect it directly to the pin. But how do I make use of the planes? I know that planes are used for Vcc's and grounds routing but can't I just connect the pins directly together? how do I use the planes?

2. What's the recommended trace width for Vcc's and ground?

1. My PCB is single sided and I'm keeping it that way. Now sometimes I get stuck while routing components that don't have pads because I have to create vias to jump from one layer to the next and that sometimes occupy space with respect to the component location and the surrounding traces. I have also tried to re-orient the components in a way that it provides the easiest routing paths possible but sometimes I still get stuck. I don't know how to deal with this. Is there another way?

1. Sometimes after routing I move the routed component but the routing doesn't move along with it as I move the component. How do I enable that option?
• You should clarify the following a bit: Is your PCB populated single side or is there only a single routing layer (uncommon)? How many routing layers are there? If you have e.g. a four layer board, you might want to use the outer layers as routing layers, and the inner layers as power planes. The difference in Altium is that a plane is full of copper except where there are lines/circles (it's drawn negatively). – Tom L. Jul 6 '15 at 14:19
• I have 4 power/GND planes (haven't used them yet). 6 routing layers currently in use. and a single PCB populated side. But even if I used the outer layers for routing, don't I need vias (which in this case I started routing & there's no space to add a new via)? @TomL. – Eman alawadhi Jul 6 '15 at 14:27
• If you have through-hole parts, as shown in your second drawing, their power and ground pins will connect to the power and ground pins with the same signal name. Also, vias on power and ground nets will connect to the appropriate plane. – Peter Bennett Jul 6 '15 at 15:14
• As @PeterBennett stated, throughhole parts will connect to the appropriate power planes (once you assigned a net to the plane / split plane). Actually you have loads of space for vias, can you show a section where you would like to place a via? Is this your first design? What are your design rules (track width, clearance, via sizes, ...) – Tom L. Jul 6 '15 at 15:30
• There is no recommended trace width for any net as this depends on your current requirements. You would usually want a full plane for each power net (especially ground). If that is not feasible you might want to look at split planes. If that's still not what you want, make the tracks as thick as they need to be at least, then add some ;-) – Tom L. Jul 6 '15 at 15:32

## 1. VCC and GND routing

Best way to deal with the GND routing is using Polygon Pour. (Related question on this site.) In Tools $\rightarrow$ Polygon Pours $\rightarrow$ Polygon Manager click on Create New Polygon From... $\rightarrow$ Board Outline

You can prefrom this action on all layers one by one, but do not forget to connect these GND pours.

As for the VCC routing it is OK as you did on your second picture. If you want to use separate VCC plane you will have to use vias to make connection between the component plane and the VCC plane.

## 2. Trace widths

It is recommended to use wider traces when dealing with higher currents. There are a lot of online trace width calculators (like this and this) to determine the required trace width. (If these tools are too compicated for you, I was told to use min. 1 mm (80 mil) / 1 A as a rough rule of thumb but maybe it is a bit of exaggeration).

## 3. Routing using multiple layers

If you could not manage the routing without using vias you have to rearrange your components either to avoid the using of vias or to make enough space for them.
Below a part of my first PCB which I have routed manually. I used 7 vias to make the highlighted route. It was one of the last remaining route and it was quite crowded there but I could find a way to connect the pads. Some may say it is not a nice track, maybe it is not. But it is good for showing that sometimes you can find place for vias, especially when you do not want to spend another day to reroute the whole PCB.

You asked for another way, Auto-Routing could be one. I prefer routing manually and I recommend you to do as well, it is reliable I think. But I must say that it is an option too. Maybe it could do the whole routing for you, maybe just a small part and you have to finish/fix the rest manually.

## 4. Drag component with connected tracks

To enable this option go to PCB Editor - General page of the Preferences dialog (Tools $\rightarrow$ Preferences). And select Connected Tracks from the Comp Drag list.

After you set this you can drag and move componenets with the connected tracks by the Edit $\rightarrow$ Move $\rightarrow$ Drag command.
Note: when using this command and the Comp Drag mode is set to Connected Tracks, the rotate, flip and TAB key commands are unavailable.