Another Via-in-Pad Reason

Just the other day — no not that one; the other one — I was reading through some of the open source Beagleboard information again and I came across an interesting tid bit. In one of the early revisions, they had some issues with SMT connectors ripping off the board. The pads detached from the board. I know that’s not  a common issue, but it does happen.

BB Empty pcb via in connector pads

Their solution was to put vias in the pads to strengthen the connection between the pads and the PCB. I hadn’t thought of that, but it makes perfect sense. Note the four dimples in each of the pads on the audio connector footprint in the image above. Also note that they are small and closed off.

If you are concerned about losing your SMT connectors, you might want to consider the via-in-pad solution. Please cap or plug them, though.

Duane Benson
Who plays pinochle on your heart?

2 thoughts on “Another Via-in-Pad Reason

  1. Nope. Bad idea. This is one technique that will certainly be forgotten from time to time. It’s best to get a more suitable connector. True, these ‘cheap’ connectors WILL get ripped off the boards from time to time when engineering is plugging in/ unplugging these connectors repeatedly. We’ve had it happen.
    Best to go with a more rugged connector, that has more soldering pads (attachment), and possible one that has a better mechanical attachment.
    One thing I notice – there are two non-plated ‘alignment’ holes in the board. Does the connector, that was ordered and installed, have these posts? Sometimes these alignment posts add to the mechanical strength. I would venture to guess, the boards have the holes, but the connectors were ordered minus the posts (often happens).
    All in all, I do not subscribe the the notion of adding these extra vias to alleviate a symptom that could be solved with proper mechanical thought.

  2. Hi Mitch,

    The two non-plated holes in the middle are for plastic nubs that stick down. Ultimately, I think connectors that need maximum strength, should be thru-hole, but I know that’s not always practical. I’d be interested in hearing from anyone else who has used the via-technique I described and what the results were.

Comments are closed.