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Many PCB-mounted connectors, in my case a USB-C have no specification regarding mechanical integration. Often, the mechanical durability seemingly relies on through-hole (sometimes even surface mount) pins. This feels very sketchy as both planar and angular mechanical stress from plug and cable will work away at these solder joints. Are there some common praxis or trade secrets to integration of such connectors?

It must be a very common consideration considering phones, laptops etc.

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    \$\begingroup\$ Yeah it is sketchy. The general solution is: don't use USB connectors in demanding environments. They've always been weak and generally unsuitable for many purposes, and USB-C didn't improve this. So what if you have to use USB? Well... your requirements are making your product worse then, whoever made the requirement will have to deal with it. "It must be a very common consideration considering phones, laptops etc" Have you ever heard of a phone or laptop USB port failing? I have... \$\endgroup\$
    – Lundin
    Mar 8 at 12:53
  • \$\begingroup\$ At some point I tried to find an alternative to USB with data transfer capability and realised how hard it is to find combination of something IP classed and tested to a large number of mating cycles. There are some medical and military connectors, but they are incredibly expensive. Considering sheer number of USB ports in everyday life I would still argue that failure rate is quite acceptable. \$\endgroup\$ Mar 8 at 13:44
  • \$\begingroup\$ Depends on what you mean with data transfer capability I guess. 100Mbps seems common for M12 and there are apparently specialized versions with transfer rates up to 10Gbps if the marketing material is to be trusted. I've no experience of such. \$\endgroup\$
    – Lundin
    Mar 8 at 13:52
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    \$\begingroup\$ @NoobPointerException for what it costs, USB is really quite remarkable. The hardware is dirt cheap and pretty robust. I remember the connectors before USB (old PS2, DB9, DB25s) and they were bulky, expensive and also not that reliable, especially if cycled a lot. USB gets stuck in everything and gets absolutely abused by users. I'm sure it could be better but then it would be too expensive. For what it's meant for, it does a very good job. \$\endgroup\$
    – Jon
    Mar 8 at 14:05
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    \$\begingroup\$ Robust design appears to me to depend mostly on the housing design. Easier when you're designing a bespoke injection-molded or machined housing. I just did a small project with USB connectors and opted for the expense of through-hole parts since the housing was not precisely made enough to provide reliable support. \$\endgroup\$ Mar 8 at 15:04

2 Answers 2

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You can get shortened 'stub' type receptacles like this:

enter image description here

The idea is that you build the main support/connection for the outer shield of the plug yourself. For example, if you have an aluminium housing, you can do it the Apple way and mill a slot that fits the USB-C plug. This way you can direct any loads into the chassis of your device rather than the circuit board and how strong you want it to be is up to you.

However I'd keep in mind that it is pretty hard to break a soldered on receptacle off a board. Even the SMT ones require a lot of strength to delaminate the copper pads. If you go for a good quality name brand receptacle, it would require a substantial force to damage, and it's more likely that the plug snaps of first. Many consumer products (older laptops, PCs, playstations etc) did it this way without any issues.

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  • \$\begingroup\$ Not sure I'd agree with "pretty hard", given that this is a common problem on mobile phones. \$\endgroup\$
    – pjc50
    Mar 8 at 13:33
  • \$\begingroup\$ Do you mean that the overmold of the cable side meets the milled aluminum before it meets the back of the USB-C? I guess that requires fine tolerances in the enclosure for the pins to still get a proper connection. \$\endgroup\$ Mar 8 at 13:49
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    \$\begingroup\$ No, the metal shield bit of the plug meets your enclosure. The connector shown only engages the last 1-2mm of the plug. You can see the plastic tongue that reaches into the middle of the USB-C plug to engage the pins. On a normal USB-C receptacle the metal bit would extend out much further and cover this completely. \$\endgroup\$
    – Jon
    Mar 8 at 13:54
  • \$\begingroup\$ @pjc50 To be fair. Manufacturing just a regular mobile phone is pretty hard. It is acatually more than just pretty hard - it is very-very hard compared manufacturing more insustrial things like traffic lights, conveyor belt controllers, CNC controllers etc. It's just that they can be made cheap because they're sold to tens of millions of people instead of maybe 60 clients. \$\endgroup\$
    – slebetman
    Mar 9 at 5:26
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    \$\begingroup\$ @Jon Honestly it isn't easy to see very much of anything there, that image is only 220×165px native resolution. TinEye scored me this 2111×1505 version where details are much easier to make out. \$\endgroup\$
    – FeRD
    Mar 9 at 8:40
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If it was a personal project I would consider adding epoxy all the way around the connector. This also requires a connector that doesn't have any internal holes for the epoxy to leak into, and probably requires a mold to keep the epoxy from flowing away from the connector while it sets. This might also be possible in a commercial project but I would be cautious about the extra assembly steps required.

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