Re: [PROTEL EDA USERS]: Via size

[HxEngr@aol.com]

In a message dated 9/11/00 5:07:36 PM Eastern Daylight Time, 
hans2@seas.upenn.edu writes:

>  I was wondering if there are any specific guidelines in setting the via 
>  size. The bigger the via, the more current can go through ... but the 
>  gain in cross-sectional area only goes up slightly with increasing 
>  diameters. Any thoughts on this?
>  
The gain in copper cross-section goes up only linearly with diameter, because 
the cross sectional area is approximately the hole circumference times the 
copper plating thickness. The PCB area blocked goes up as the square of the 
diameter. To get more effective area (either for higher current capacity or 
lower inductance, etc.), it is sometimes more effective to use two, three, 
four,.... small vias rather than one large one.

Steve Hendrix