I hereby certify that I am not simply asking someone else to design a footprint for me.
Hi,
I am currently trying to design a footprint for the LMR60410 step down converter from TI.
The recommended land pattern has a lot of L-shaped pads with rounded corners. The definition can be found here https://www.ti.com/lit/ml/mpqf742d/mpqf742d.pdf
My approach was to draw the shape with lines, use the “Shape Modification” tool to add rounded corners and than convert the shape to a polygon.
But I ran into the problem that the corners of the polygon are not round.
This image shows the line shape with different line widths for test.
After converting it to a polygon it looks like this:
Is the pad to small or is there a better way to do this kind of shape?
I tried a smaller pad and it is visible indeed.
This is roughly 0.6 x 0.7mm, fillet 0.1 mm. Line thickness 0.05 mm.
The image below shows roughly 0.15 x 0.12 mm area. The steps are roughly of 0.03 mm, so not bad considering this has to be manufactured and probably will be rounded anyway (or squared) in the PCB manufacturing process.
Corners “stepped” issue is very common in CAD software when you zoom it in enough. Depends on the software - sometimes it is only visual, sometimes this is actually how the part will look in the real life
Not sure how it is in KiCad though.
I personally would not assign that odd footprint. I would just use the standard footprint for that package and then, in layout, use filled zones to satisfy their suggestion (more or less).
If you want to use a finished layout with all the caps and inductors, a block (or how is it called?) would be a better option.
