Hmm... What is heat dissipation ?

I guess it is dissipation of heat in air, right ?
So there is difference in temperatures in copper
and surround air. The higher temperature is around
the less heat can be dissipated for the same time.
As I remember there is also such a parameter as
thermal resistance (please correct me if I wrong,
I don't remember exact english term for that) It is
used in heatsink and so stuff design.

WBR Dmitry.

Jilles Oldenbeuving wrote:
>
> Resistance will determine the heat-dissipation, but not the temperature
> rise,.
> Becouse how longer the track, the more the heat-dissipation will be
> distributed
> along the track...
>
> Regards,
>
> Jilles Oldenbeuving
> jilles@rendo.dekooi.nl
> -----Oorspronkelijk bericht-----
> Van: TOM THERON <mmsesys@ICON.CO.ZA>
> Aan: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
> Datum: dinsdag 30 mei 2000 16:27
> Onderwerp: Re: [EE]:Current on a PCB
>
> >I did some PCB's  for power applications a while ago, and we handle up to
> >30A in tracks with 70 micron copper and 10mm MINIMUM width. However, where
> >possible we fill out areas to act as heatsinks, i.e. some places tracks are
> >30mm wide.
> >
> >It is not only the track width that has an impact, but also the length,
> >since the resistance is a function of the whole track area, and this
> >influences the actual heat dissipation (IIR).
> >
> >Tom Theron
> >