Re: Package pad size different when placed   on PCB

Olin wrote on Thu, 18 March 2010 07:09

dingebre wrote on Thu, 18 March 2010 03:44

I got the package designed and had to use a "diameter" very close

to the "drill size" to keep adequate clearance for the pins.

 

But you also used oblong pads, which made the clearance problem worse.

It looks like circular pads would help in this case.

 

Quote:

When I bring the package into the device editor window and onto the

PCB, the pad defaults back to the auto size and the mounting tab pads

overlap the pin pads. What am I doing wrong?

 

I'm guessing the DRC settings are overriding the library settings.

Make sure the minimum width is set small enough to allow for this part,

and that restring and the like aren't overridden.  Somewhere there is a

checkbox called something like "From library" or "Use library settings".

Make sure it's checked.

Thanks Olin. I was thinking the DRC rules were doing something, but the

help file wasn't helping...

David

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dingebre wrote on Thu, 18 March 2010 09:11

Olin wrote on Thu, 18 March 2010 07:09

dingebre wrote on Thu, 18 March 2010 03:44

I got the package designed and had to use a "diameter" very

close to the "drill size" to keep adequate clearance for the pins.

 

But you also used oblong pads, which made the clearance problem

worse.  It looks like circular pads would help in this case.

 

Quote:

When I bring the package into the device editor window and onto

the PCB, the pad defaults back to the auto size and the mounting tab

pads overlap the pin pads. What am I doing wrong?

 

I'm guessing the DRC settings are overriding the library settings.

Make sure the minimum width is set small enough to allow for this part,

and that restring and the like aren't overridden.  Somewhere there is a

checkbox called something like "From library" or "Use library

settings".  Make sure it's checked.

 

Thanks Olin. I was thinking the DRC rules were doing something, but the

help file wasn't helping...

 

David

Hi Olin,

Changing the pads to round solved the overlap problem, thanks. However, I

never could find out how to override the restring settings for a single

part and changing the restring parameters did not correct the overlap.

maybe a bug?

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

dingebre wrote on Thu, 18 March 2010 17:08

Changing the pads to round solved the overlap problem, thanks. However,

I never could find out how to override the restring settings for a single

part and changing the restring parameters did not correct the overlap.

maybe a bug?

Highly unlikely.

I just checked, and the override I was thinking about applies to pad

shapes, not sizes.  I guess that makes sense as you can't have it both

ways.  Either .008 (or whatever) is the minimum acceptable width or it

isn't.  Note that you can set this per net with CLASS, and DRC enforces the

minimums.

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.