trace thickness (copper 1oz/2oz)

[docaat]

Hi, I am in the midst of design a module for automotive use.  This board will be interfaced with the power wiring of an automobile.  When doing the layout for this is there any way I can specify the weight or thickness of the copper traces so that it will be able to handle the high amperage from a car battery?

Thanks,

-Ronak Patel

[lacy]

I have looked for a way to adjust the copper thickness and I haven't found anything. It may be a copper layer set-up that I am not toatally familiar with.

The one option that I do know of is the use of power planes. Take your power connections and ground connections and set-up a power plane for both of them. This would mean that you would have to run power on one side of the board and ground on the other side when routing. This should take car of any problems with the traces not being able to handle a car battery.

I do have one question. If you hook a circuit into a car battery it is going to see 12V and only draw as much current as it needs. Unless your circuit draws extreme amounts of current why would you need extremely thick copper traces?  This question may sound strange, but I have always been under the impression that it is the current draw of the circuit that determines how beefy the traces must be.

[kittmaster]

By definition, Gerber data does not specify height of a trace, that information must be passed on the PCB house when you order the layers and specify their value. Search google for a trace calculator and it will tell you based on copper weight how wide the trace should be vs. thickness

[hygren]

This is my favourite trace calculator:
http://circuitcalculator.com/wordpress/

However since there are only two traces that use this vast amount of current I would follow the suggestion above and divide one copper layer into two planes or one layer each depending on how many layers you are using...

[docaat]

I used the trace calculator listed above, i specified the wire guage as well as how long it was and in the results it specified copper weight.  How can I adjust that in Multisim/Ultiboard?

[lacy]

Please refer to kittmaster's post above as I think he has already outlined what needs to be done.

[johnnewyork]

hi guys

i finded one option for modify tickness,but line by line,manual

go and click right on line,have option to select one part or all line,after check in menu PROPRIERTIES,and measureament,and width-put your value and done