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Re: gEDA-user: 0805 geometry, was: Script for converting mm to hundredths of thou



Doublechecking this, the RESC2012N looks pretty much the same as the 0805
footprint. By comparison the 0603 aka RESC1608N.fp looks reasonable as does
the 1206.
- why would the 0805 have the same center clearance of 800um as the 0603?
I think this is just a bug in the library that apparently got copied around as well. When I showed this to a friend using Target, he also said, the 0805 landpattern looks wrong.

Just my 2 cents

Otherwise, thanks for the info on mask clearance, I'll incorporate it.

Maybe now is the time to keep my promise about the footprint for the
Texas Instruments bq24103 that's attached. It has a grid in the central solder paste- apperture and thermal vias now. At least I hope the pins act as thermal vias...

DJ Delorie wrote:
Clearance is the difference in widths of the copper pad and the mask
opening.  I.e. it's twice the clearance gap.

Mask is an absolute width, not related to the copper size.

The CAPC*, RESC*, and INDC* footprints are the ones you should be
using for "standard" 0805 etc footprints; those are based on (IDC?
JEDEC?) published standards for such things.  RESC2012N is the default
0805 for resistors; it's different than CAPC2012N for capacitors, etc,
and slightly different than the "0805" footprint.

Most fabs want a 3 mil (75um) gap between copper and soldermask.  For
a 900um copper, that means a 1050um minimum mask.


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Attachment: TI_PQFN-N20_v3.fp
Description: application/pcb-footprint


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