Author Topic: copper expansion in library  (Read 1991 times)

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Offline vini_i

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copper expansion in library
« on: August 16, 2015, 12:19:24 pm »
I'm designing a library part for a reverse protection schottky diode (SMD). The part is going into a bunch of different boards that will be designed by a bunch of people. I want to provision in to the part some extra thermal relief. This is so that anyone that uses the part automatically has the same added features. I want to do this by expanding the copper underneath the pads but without  affecting the size of the stop layer. This way the diode is easier to solder down.

So far i've tried making the pad larger but that makes the stop larger too and i'm not sure how to make it smaller. I've tried making a polygon under the pad but there is no way to name it and the DRC gives error when the part is placed in a board. The same thing happens if rectangle is used as well.

how do i make the pad copper larger but not affect the size of the stop?
 

Offline kizzap

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Re: copper expansion in library
« Reply #1 on: August 16, 2015, 12:54:23 pm »
IIRC you can stop the Stop layer populating for the pad, and then just manually draw it in.
<MatCat> The thing with aircraft is murphy loves to hang out with them
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Offline vini_i

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Re: copper expansion in library
« Reply #2 on: August 16, 2015, 11:32:15 pm »
That did the trick, thank you. I first placed the pads with the dimensions and locations from the data sheet. Then i placed a second stop layer over top of the pad and adjusted the size until it matched the stop on the pad. I then turned off stop and cream of the pad and adjusted the pad to the desired size.
 


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