Via Calculator

[phillipr]

Anyone know where i can find a calculator that works out current for Via holes?

[Colorado-PC-Dude]

Phillip,

This article http://www.ultracad.com/viacurrent.pdf confirmed what we've been doing. We have simply made sure that the cross-sectional area of the via "barrel" is at least as much as the cross-sectional area of the trace.

Ben

[randychase]

Yup. I have always did the Pi*dia to get the "trace width" and the plating in the hole is the thickness. Then I always want to err on the too many vias.

For power boards, I have increased the size of the vias in order to get more 'trace width."

[phillipr]

Hi all

I have created a Via Current Calculator based on Windrivers Trace calculator (Hope you don't mind Tom).
I need to see how accurate it is. Has anyone got any true figures that I can check it to.
I need to know via size and maximum current in Amps.

[randychase]

Here it was!

[Tom]

Phillip,

Good Job Lad! I'm so glad that someone else is creating tools and giving them away for the benefit of the entire electronics community.

It's really too bad that PADS does not have these features built into the software. I mean after all, what PCB designer does not need a Via Current Calculator? This is long overdue. So far to date, we've had to manually calculate these values. Every engineer wants to know this information and when they aren't sure, they overkill with statements like "Put at least 4 vias on that Bulk Capacitor".

By the way, all Wind River technology is available for the general public to recreate new products. Whenever the term "Standard" is used, everyone has the right to do whatever he or she wants to with the products with one exception - make a financial profit by reselling or redistributing the products.

Thanks for the contribution.

[phillipr]

Tom

Well said!!

I totally agree, that is why none of my excel based programs are password protected.
I have no objections to anyone using the programs or modifying them to make them more useful.

[phillipr]

Hi all
Now that my Via calculator is out on the listserver.
And pcbstandards.com I would like some feedback.

I am in the process of updating the units to be more flexible. I would be grateful if you could compare it quickly to a couple of sum you may have used in the past. Even better tests you have conducted on actual boards So I can “tweak” the equations to be more accurate.

[tboyer]

Why does the expected current have to be half the calculated
current to get one via? Does this mean that your calculation
expect two vias or more?

[phillipr]

I will fix this is the next release (next week or so)
Its rounding the value down below 0.5.
I need it to always round the figure up.

[randychase]

HI All
I have updated the Via current Calculator to V2.1


You now have the choice between the following units
Mm
Microns
Thou
Oz


I have also fix the rounding error on the minimum number of vias required.

[phillipr]

Randy

the attachment is not present

[randychase]

HI All
I have updated the Via current Calculator to V2.1


You now have the choice between the following units
Mm
Microns
Thou
Oz


I have also fix the rounding error on the minimum number of vias required.

[phillipr]

The Via Calculator has now been incorperated into a new tool
Download it here.
http://www.pcbstandards.com/forums/showthread.php?s=&threadid=871