[SI-LIST] Re: PCB solder current carrying capacity
- From: Doug Brooks <dbrooks9@xxxxxxxxxxxxxxx>
- To: "si-list@xxxxxxxxxxxxx" <si-list@xxxxxxxxxxxxx>
- Date: Tue, 21 Jul 2009 16:12:51 -0700
In one of the articles on our web site re current carrying capacity
of traces, we include this observation (which is approximate).
The resistivity of solder (depending on its composition) is
approximately ten times higher than that for copper. Thus, you can
think of the trace (pad) and solder as being two conductors in
parallel --- one with 10x the resistance of the other (assuming
similar widths and thicknesses.)
On standard traces, we tell our customers to ignore the current
carrying capacity of the solder and just consider the copper itself.
Then it is determined just by the cross-sectional area of the copper.
Doug Brooks
UltraCAD
http://www.ultracad.com
At 11:03 AM 7/21/2009, Gumaste, Vijaylaxmi wrote:
>Hi,
>
>
>
>I want to determine current carrying capacity of solder pads -
>effect of solder material/ land-pad size for very high current
>applications (>5A-10A per solder pad)
>
>
>
>I can use IPC spec to design appropriate metal layer trace
>widths/thickness for a required temp rise.
>
>However, I am looking at options to estimate/calculate/simulate
>current carrying capacity for solder pads.
>
>
>
>
>
>-Vijaya.
>
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Check out our resources at http://www.ultracad.com
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