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PCB DESIGN

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gsingh11:
Hi, I am making my first ever PCB for my project. I have some questions in mind. Actually, i am driving a 3A motor with it and i am not sure what should be the track width of my traces to support my current. And if you find some more errors please help me resolve it before I send it to manufacture.

ataradov:
High current tracks should be as wide as possible. And depending on the situation, it might make sense to make them out of filled polygons, not the tracks.

Layout is pretty messy, but this is typical for a first board. Most of the vias here are not necessary with careful rearrangement. And remember that component holes are vias on their own. Look at the track between the IC and R2. It all can just go to the blue layer. Same with R1. You already did it for the R3, why add 4 vias for the others?

And add ground fills on both layers. This will further eliminate messy routing.

woody:
Kicad has a nice calculator tool that gives you an idea as to how wide a track should be for a given current (and copper thickness, temperature rise etc). Without taking it as gospel it shows you how these variables influence each other.

Doctorandus_P:
It's a combination of temperature rise and voltage drop, and you can get a quite good idea from that from KiCad's built in calculator (from the project manager menu) as woody already mentioned.

On top of that PCB layout also has a very big influence. Consider an extreme example of a power distribution board. One connector with 10A goes in, and 10 connectors (each with 1A) go out.
If you put the 10A connector on the side of the board, then you have a 10A PCB track that has to go all the way to the 10th output connector. Just by moving the 10A connector to the center of the PCB, you split the PCB tracks in two 5A tracks right at that connector, and the average lenth of the copper track has also halved, so that is a factor of 4 improvement (in temperature rise and voltage loss) just by moving a single connector.

woody:
An example of what @Doctorandus_P meant I used in a proto recently. Including the fat tracks used for high currents and cooling.

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