[SI-LIST] Re: Flooded Vias vs Thermal Relief

Hmmmmm,
How to address this one while being cordial. Ok, for
starters, sarcasm cannon set on stun........

OK, let's start with the low hanging fruit and move up.
We certainly don't want things to be difficult for you while
checking, so leave the thermals on for your check and then
change them when you are done. The best of both worlds
right?  As you said, it's only a mouse click.

I humbly suggest that you track down the origin of thermal
attach vias and why they exist. I will give ya a hint.  Through
hole components.  Hint two, a smt lead and fanout to via is
also like a thermal attach.

Have slicing and dicing simulation or tests been performed
that show the impact of thermals on power distribution?  Yes.
If packed tightly and deeply enough you have a fraction of the conductor
cross section that you thought you had.   With high enough
current, bad things can and will happen regarding conductor
temp rise.

Never back a methodology with the argument, "Well that's the
way that I've always done it and its easier."


Best Regards,

Michael C. Greim

And all this science they don't understand
Is just my job six days a week.....

We will either find a way or make one   -Hannibal

In the middle of every difficulty lies opportunity   -Al Einstein


 Jack Olson <pcbjack@xxxxxxxxx>
> Sent by: si-list-bounce@xxxxxxxxxxxxx
> 03/19/2010 08:43 AM
>
> To
> SI-LIST <si-list@xxxxxxxxxxxxx>
> cc
>
> Subject
> [SI-LIST] Flooded Vias vs Thermal Relief
>
>
>
>
>
>
> Greetings,
> I am being instructed to flood all vias instead of using thermal relief,
> to
> get a "better" connection to planes. I've typically used thermal reliefs
> simply because they are easier to see in checking or design reviews (but
> its
> only one mouse click for me to change them so I'm not really complaining).
>
> but it got me thinking.....
>
> Have any test results ever showed that spokes have a significant impedance
> or anything that can change circuit performance?
> (and I'm referring to 12mil plated through-hole vias on boards 100MHz max)
>
> I don't remember anyone ever talking about that.
>
> surfin' the learnin' curve,
> Jack
>
>
> ------------------------------------------------------------------
> To unsubscribe from si-list:
> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
>
> or to administer your membership from a web page, go to:
> http://www.freelists.org/webpage/si-list
>
> For help:
> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
>
>
> List technical documents are available at:
>                http://www.si-list.net
>
> List archives are viewable at:
>                                 http://www.freelists.org/archives/si-list
>
> Old (prior to June 6, 2001) list archives are viewable at:
>                                 http://www.qsl.net/wb6tpu
>
>
>
>
>
> ------------------------------------------------------------------
> To unsubscribe from si-list:
> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
>
> or to administer your membership from a web page, go to:
> http://www.freelists.org/webpage/si-list
>
> For help:
> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
>
>
> List technical documents are available at:
>                http://www.si-list.net
>
> List archives are viewable at:
>                http://www.freelists.org/archives/si-list
>
> Old (prior to June 6, 2001) list archives are viewable at:
>                http://www.qsl.net/wb6tpu
>
>
>


--


------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
http://www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field


List technical documents are available at:
                http://www.si-list.net

List archives are viewable at:     
                http://www.freelists.org/archives/si-list
 
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu
  

Other related posts: