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Upgrade NXP_LQFN-48 Package

Matyas Mehn requested to merge matyas1995/kicad-footprints:fix_NXP_LQFN-48 into master

Hello,

I created the Package NXP_LQFN-48 in two variants (one with thermal vias and one without) and submitted it in PR !2350 (merged)

Package_DFN_QFN.pretty/NXP_LQFN-48-1EP_7x7mm_P0.5mm_EP3.5x3.5mm_16xMask0.45x0.45.kicad_mod Package_DFN_QFN.pretty/NXP_LQFN-48-1EP_7x7mm_P0.5mm_EP3.5x3.5mm_16xMask0.45x0.45_ThermalVias.kicad_mod

After using the Footprint in some projects I have found it quite impractical for two reasons:

    1. Some PCB manufacturers offer small via sizes only as an extra for surcharges, so setting 0,25mm thermal vias in the package might just get a PCB into the 'premium' price range, while 0,3mm vias would still be perfectly fine.
    1. When using the package variant without Thermal vias it is not possible to set thermal vias between the pads manually, since the center ground pad is designed as one large copper area with 16 individual mask cutouts for the package pads. KiCad does not really likes setting vias that overlap with pads.

This is how the footprints look as of now:

image image

When creating these packages, I somehow did not realize that instead of creating a large pad with individual mask cutouts, I could also just create 16 individual pads with the same pad number and KiCad would just assign those to the same symbol pin. (Just HOW could I overlook that?)

Now, I removed the

Package_DFN_QFN.pretty/NXP_LQFN-48-1EP_7x7mm_P0.5mm_EP3.5x3.5mm_16xMask0.45x0.45_ThermalVias.kicad_mod

package variant and modified the

Package_DFN_QFN.pretty/NXP_LQFN-48-1EP_7x7mm_P0.5mm_EP3.5x3.5mm_16xMask0.45x0.45.kicad_mod

package to have 16 individual center pads, like in this picture:

image

I think it is reasonable to expect from the users to read the Part's documentation, where it is clearly stated that these pins should be connected by a solid copper pour, which can be easily achieved in KiCad. Vias can then also be placed and dimensioned according to individual needs.

Greetings, Matyas

All contributions to the kicad library must follow the KiCad library convention

Thanks for creating a pull request to contribute to the KiCad libraries! To speed up integration of your PR, please check the following items:

  • Provide a URL to a datasheet for the footprint(s) you are contributing
  • An example screenshot image is very helpful
  • If there are matching symbol or 3D model pull requests, provide link(s) as appropriate
  • Check the output of the Travis automated check scripts - fix any errors as required
  • Give a reason behind any intentional library convention rule violation.

Be patient, we maintainers are volunteers with limited time and need to check your contribution against the datasheet. You can speed up the process by providing all the necessary information (see above). And you can speed up the process even more by providing a dimensioned drawing of your contribution. A tutorial on how to do that is found here: https://forum.kicad.info/t/how-to-check-footprint-correctness/9279 (This is optional!)

Edited by Matyas Mehn

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