What is the best way to add plated mounting holes to a device footprint?

[ah.harvey]

A good example would be the four through hole mounting pegs in each corner of a usb connector  (e.g., https://www.molex.com/pdm_docs/sd/2171790001_sd.pdf).

My approach to adding these holes to a footprint has been: 

1. use the smd pad tool to draw the outer shape according to dimensions and radius provided in the datasheet.

2. use the rectangle tool on layer 46 (milling) to draw the hole (I would also use the miter tool if the hole corners have a radius, as they do for the Molex usb linked above). 

I have run into some problems with this approach. 

1. The holes do not appear to be reflected in the 3D model of a PCB which uses this device (not a huge problem so long as the PCB fabricator is aware that a hole is requied). 

2. The holes are not acting as a via between top and bottom layers (e.g., in the case of the Molex usb linked above, I would expect these holes to act as a via between top and bottom GND planes). 

Is there a better way to add plated mounting holes to a device footprint?

[ImDaveM]

See if this video helps.

https://www.youtube.com/watch?v=Ui5P4bGcURc

[ah.harvey]

Thanks @ImDaveM, this is a useful video. This is pretty much the approach I have used.

When I use top and bottom later SMD pads, I cannot get the top and bottom nets to connect once the device is added to a PCB. This means that DRC always raises airwire errors for these pads.

If I use a PTH pad then the top and bottom layers do connect as expected in the PCB. However, in my particular case I need a longer pad, meanwhile Fusion 360 only allows PTH diameter and drill parameters to be defined.

Should the top and bottom SMD pads be connected automatically once the milling outline is added?

[jorge_garcia · Accepted solution]

Hi @ah.harvey,

I hope you're doing well. You can use the plated through hole and then enclose it within a polygon to extend the copper. This is the arbitrary pad shape feature.

Let me know if there's anything else I can do for you.

Best Regards,

[ah.harvey]

thanks @jorge.garcia. This does indeed work. It is, however, a massively convoluted process for quite a common task. Not only does the copper polygon need to be drawn, but also polygons for the stop and cream layers, plus an outline for the milling layer, plus adding radius to each of these layers if required by the datasheet, and then repeat all of this for each peg (which may be four or six). And then keep fingers crossed that no finessing or editing will be needed, as making adjustments to all of this is a nightmare. It is a shame Fusion does not have an easier method of performing this common task.

[josephficara]

Have any of the updates to Fusion 360 made creating plated through holes a more streamlined process?

[josephficara]

Have any of the updates to Fusion 360 made creating plated through holes a more streamlined process?

[jorge_garcia]

Hi @josephficara,

I hope you're doing well. The main improvement in this field has been the addition of slotted drills. So if you are trying to use this for a slotted drill, then just use slotted drills in the library. If you have something more particular then you'll have to use the above process.

Let me know if there's anything else I can do for you.

Best Regards,