PCB outer copper weight (1 oz vs 2 oz)?

[[Chrille]]

I am about to order my first PCB from a PCB manufacturer but I am a bit confused about the option to get it manufactured with 2oz copper weight vs the standard 1oz outer copper weight.

Is 1oz enough for a computer mainboard PCB? How much current can 1 oz carry?

Thanks!

[SteveyG]

1oz is standard, but how did you design your track widths in the first place? You must consider the current to determine the track width at all points in the design.

[IconicPCB]

Google  PCB CALCULATOR. it will get you to an online utility which will guide You.

[phil from seattle]

What is the highest current you expect to see on your board?  Even 1 Amp can be easily handled by 12 mil 1 oz copper trace.

[[Chrille]]

Thanks for all of your replies!

I Googled PCB calculator and found some online calculators that I used. The track width for the power supply rails of the PCB is 1.3 mm or about 50 mil, which should be more than sufficient for my needs as it seems. The maximum current that will pass through the circuit is 1.5 Amps.

The calculator show different values for internal traces and external traces for the same current. But internal traces only apply to PCB's with >2 layers, right? The PCB I want to order is a 2 layer board so all traces are external.

Please correct me if I am wrong 

[jusaca]

The calculator show different values for internal traces and external traces for the same current. But internal traces only apply to PCB's with >2 layers, right? The PCB I want to order is a 2 layer board so all traces are external.

Please correct me if I am wrong 

You are absolutely right. Internal traces are thermally better isolated due to the surrounding PCB material and heat up faster than external traces.

[SteveyG]

It still begs the question how have you designed a PCB without taking any of this into account? 

[T3sl4co1l]

And a "computer mainboard PCB" at that?  Is this one of the open source retro things and you're ordering some copies..?

Tim

[[Chrille]]

It still begs the question how have you designed a PCB without taking any of this into account? 

I didn't design it. It is an open source project that someone else designed. The reason I asked is because I want to learn how stuff works. I want to get a board manufactured for personal hobby use. Nothing more advanced than that 

And of course I would like to be able to create my own PCB designs for other projects in the future and you have to start somewhere, right?

[Kean]

So if it is an open source design, why not provide a link to it?

Then people here would be able to give much more appropriate suggestions than guessing what your concept of a "computer mainboard PCB" might be.