[SI-LIST] Re: Resistance

  • From: Aubrey_Sparkman@xxxxxxxx
  • To: xlzhou@xxxxxxxxx, si-list@xxxxxxxxxxxxx
  • Date: Mon, 13 Aug 2001 14:35:12 -0500

Hi Mick!

Aside from the differences (plated vs anealed, pure vs alloyed and layered)
others have pointed out, is it possible you had a sign error in your
calculations?  resistivities for copper are in the mid e+7s not e-7s as you
have below. 

Aubrey Sparkman
Signal Integrity
Aubrey_Sparkman@xxxxxxxx
(512) 723-3592


> -----Original Message-----
> From: Zhou, Xingling (Xingling) [mailto:xlzhou@xxxxxxxxx]
> Sent: Monday, August 13, 2001 9:07 AM
> To: Si-List (E-mail)
> Subject: [SI-LIST] Resistance
> 
> 
> 
> Hi, 
> 
> When you calculate the DC resistance of wires and traces, 
> which resistivity
> values should be used or more practical ? Most books give
> 1/5.8e-7 = 1.724e-8 for pure cooper. However, Dr. Johnson's book gives
> 6.787e-7 (p.411) and he explained his reasons. On p.409, he 
> mentioned that "
> the authors have used MathCad to evaluate each of the 
> following formulas in
> well-known test cases...".  Obviously, the 
> two values are quit different, three times ! So,  please provide your
> suggestion ?
> 
> Thanks.
> 
> Mick
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