Calculating Track Widths

[2camjohn]

Is there an equation I can use to work out how thin I can make the tracks on my board without getting too hot or turning into a resistor.


I know there are factors involved that are hard to measure accurately, such as thickness of copper but I need an equation to work out ideal track widths in normal conditions.

If anyone can help out, or knows of any websites that deal with this topic then please let me know...


Cheers
John

 

[Roff]

Google, man, Google! "pcb track width" yielded this calculator as the first hit:
https://www.desmith.com/NMdS/Electronics/TraceWidth.html

 

[2camjohn]

OK you got me there I should have googled first...




Anyway I can use that equation to work out the min cross sectional area of the track, so in order to work out the width I need a rough idea of the thickness of a track.

Can anyone suggest to me a sample thickness for the track, perhaps the minimum and maximum normal copper clad boards would use...

Thanks again
John

 

[Optikon]

OK you got me there I should have googled first...




Anyway I can use that equation to work out the min cross sectional area of the track, so in order to work out the width I need a rough idea of the thickness of a track.

Can anyone suggest to me a sample thickness for the track, perhaps the minimum and maximum normal copper clad boards would use...

Thanks again
John

For thickness you will need to do some geometry to take into account the "finished" track cross section _after_ etching. You can find this in IPC standards documents.. maybe google for it.. but for all practical purposes use the copper weight (1.0 oz, 1.5oz and 2.0 oz are common).

Even better, you can usually input this into some calculators as found above to yield current handling capability for a given temp rise.

Also, don't calculate your way into something that a PCB board house can't make or is not standard.

 

[bmcculla]

Here's a table that I've found useful for track width.

https://circuitboards.com/capacity.php3

 

[Optikon]

Google, man, Google! "pcb track width" yielded this calculator as the first hit:
https://www.desmith.com/NMdS/Electronics/TraceWidth.html

I really like this one! I think it's better than UltaCad's baseline version. Seems to be more accurate for larger magnitudes of the various parameters.

 

[gmphadte]

Track width and much more can be found in Fakta.pdf at www.elfa.se