Hello Nicholas,

They are used when you want to connect to the internal power /ground planes.
The connections to the internal planes need to connect electrically, but
not act as a heatsink when soldering or reworking.
So, thermal relief pads are used to make these connections.
You may find some guidelines on thermal relief pads in IPC-2222.

regards,
Phil.

At 14:51 27/08/99 +0800, you wrote:
>Hello
>all
>
>I have some questions need to inform your help....
>In the inner layer design of PCB. I always observe there is many thermal
>pad.....
>What is the function of the thermal pads?
>What is the advantage of thermal pads.
>
>Best Regard,
>Nicholas Lai
>8/27/99
>
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===============================================================

Phil Dutton C.I.D.
Senior CAD Technician
IPC Certified Interconnect Designer
Vision Abell Pty Ltd
Second Avenue, Technology Park,
Mawson Lakes.  SOUTH AUSTRALIA  5095

Phone :         (08) 8300 4400 (reception)
                (08) 8300 4481 (direct)
Fax :           (08) 8349 7420
email:          [log in to unmask]
Internet Page:  http://www.vsl.com.au

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