SOIC-14_N and SOIC-14_W footprints mistakenly interchanged!

[kicad]

SOIC-14_N and SOIC-14_W footprints mistakenly interchanged!

It seems that SOIC-14_N is correct by comparing it with a following datasheet: http://www.analog.com/static/imported-files/packages/PKG_PDF/SOIC_Narrow%20(R)/R_14.pdf

SOIC-14_W is not a reflection of the SOIC 14 Wide Body package, according to this note: http://www.analog.com/static/imported-files/packages/54614177245586RW_14.pdf
It isn't also said that the letter "W" refers to the Wide Body package. Considering the smallest possible size between the edges of pins (H dimmension), SOIC-14_W also fits the Narrow version.

[joseangeljimenez]

Hello,

Thanks for take the time for looking into this. I could invest some time into this today. Could you, please, check my findings below?

Using the Analog Devices reference for the SOIC-14 NARROW body device,

• According to the Analog Devices reference, the typical distance between the center of the contactact pins for the narrow device is 6.00 mm - 0.835 mm = 5.165 mm.
• The inner-distance between the pads of the current KiCad SOIC-14_N footprint is only 5.21 mm, which would barely contact the pins IC and only if the pick & place machine happens to place the device with absolutely no error (!).
• The center-to-center distance between the pads of the current KiCad SOIC-14_N footprint is 6.35 mm, which is much longer than the expected 5.165 mm.

Using the Analog Devices reference for the SOIC-14 WIDE body device,

• According to the Analog Devices reference, the typical distance between the center of the contactact pins for the wide device is 10.325 mm - 0.835 mm = 9.49 mm.
• The inner-distance between the pads of the current KiCad SOIC-14_W footprint is 4.19 mm, which is too small for a SOIC-14 WIDE device, however suitable for a SOIC-14 NARROW device (allowing for about 1 mm of error margin for the pick & place machine).
• The center-to-center distance between the pads of the current KiCad SOIC-14_W footprint is 5.33 mm, which is much longer than the expected 9.49 mm. However, it is nicely close to the expected 5.165 mm of a SOIC-14 NARROW device.

In summary,

• An Analog Devices SOIC-14 NARROW device will not land correctly on a KiCad SOIC-14_N footprint, but will land nicely (centered) on a on KiCad SOIC-14_W footprint.
• An Analog Devices SOIC-14 WIDE device will not land correctly either on a KiCad SOIC-14_N footprint or a Kicad SOIC-14_W footprint.
• On top of the previous, I find very confusing that the KiCad SOIC-14_N footprint is in fact wider than the SOIC-14_W footprint.

Assuming most SOIC-14 devices are manufactured in narrow packages, most of the users of KiCad will select the SOIC-14_N footprint, without further check, finding later that the footprint is not correct for a narrow device. :-(

Best regards,
José Ángel Jiménez

P.S.: This is the calculations I carried out, for the case of a narrow device. I did similar for the case of a wide device.

[Shackmeister]

@joseangeljimenez would you mind if I close this? It's probably pretty deprecated by now :)

[Shackmeister]

@joseangeljimenez hi Ill close this up due to the inactivity, if you want to continue you can simply reopen it