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Reply To: | TechNet Mail Forum. |
Date: | Fri, 5 Dec 1997 11:21:39 -0800 |
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Stephen C Joy wrote:
>
> Text item: External Message Header
>
> I would like to understand the current capability of pcb manufacturing with
> respect to thermal relief. The 3 actions would be:
>
> 1. PB mfg places thermal relief patterns at "true" locations in the
> aperture file.
>
True
>
> 2. thermal relief are created at PB mfg based on text notes in aperture
> file. Text notes are complicated and must be associated with the correct
> "hole" in the case of multiple thermal relief.
>
False. The thermal is flashed like any other pad. You specify what
ID,
OD, # and size of spokes in your aperture definition file, just
like you
would with any other flash.
>
> 3. Area fill thermal ties will default to narrowest trace unless a text
> note in the aperture file is acted upon by PB mfg.
>
See above.
>
> Is this true?
> How do you control multiple thermal patterns?
>
They are flashed, as long as the layout software can handle that.
>
> Is the thermal pattern still required?
>
For thru-hole parts, yes.
>
> Are there any rules for current vs no thermal relief? ..like hole size,
> copper weight, etc.
>
I use IPC specs for internal layers. Or (shameless plug alert) the
trace
width calculator on my web site ( http://www.aracnet.com/~gpatrick )
(:-p
>
> Steve
>
--
/\ Praegitzer Design
/\/\ A Division of Praegitzer Industries, Inc.
/\/\/\ Portland Design Center
/\/\/\/\ 7245 NW Evergreen Pkwy. #100
---------- Hillsboro, OR 97124
George Patrick, Sr. PCB Designer Email: [log in to unmask]
Voice: (503) 531-2050 ext. 1813 Fax: (503) 531-2051
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