pcb design - Using a via to strengthen surface mount connector on or near pad

I am trying to design a board that has a surface mount connector. I was shown a picture of an example board that has vias on the pads of the connector. I don't believe the via is for connecting to a layer necessarily. Meaning I was told that they were used for strengthening the mechanical structure near the connector so that it would be more difficult to yank off when pulling and pushing in the plug.

Has anyone ever heard of this? I believe I have heard of putting a plugged via right next to a mechanical pad so that the board is stronger there. But I'm not sure what the implications are for putting a via on the pad? I've been searching the web and I can't find much. Maybe I just don't know the proper terminology for this application.

So is there a standard for adding strength to surface mount connectors? Is putting a via on the pad a good or bad practice, other than expense? Does putting a via directly next to the pad help?

Answer

That's a new one on me! There are other reasons for putting a via in the pad, but strengthening a connector is a new one.

The weakest part of an SMD pad is that the copper could delaminate from the fiberglass, and lift off the PCB itself. Anything you could do to prevent that would help, including making the pad larger or putting a via in the pad itself.

But you have to be careful, since putting a via in the pad can cause other issues. The first problem is that it might make the pads not flat enough, so a connector pin won't make good contact with the pad and thus not get soldered well. The second issue is that the solder could get wicked down the via and leave nothing left for the connector pin. This isn't a big issue if you are hand soldering, but can be a problem when doing it with automation.

Honestly, if connector strength is an issue then seriously consider going to a through-hole connector or some type of connector that gets strength from some other means. Maybe a connector that gets bolted to the chassis itself (and stress on the PCB is minimal). Or even a different connector entirely.