Questions regarding working with USB ports/connectors

Hi guys, sorry for the noob question -
I’m working with a USB-C connector for the first time and it has some pins (GND, VCC) which are made up of two adjacent pads to cater to whichever orientation the cable is plugged in.

Before I order these boards I just wanted to get some advice please:
• When I connect two separate traces to these pads, there is a small gap. I considered increasing the track width but I was just wondering if there was a more standard approach to these?
• For the ground pins, I’ve routed them to a via and then I have a ground plane on the reverse side of the pcb, is this the correct approach when working with SMD components that have pads?
• I routed the D- and D+ as differential pairs (for the first time) but I had to connect to vias via traces away from the pads to make it work - does it matter if the total length of the traces are not identical or do they need to be the same?

Adjacent pins:

Overview:

To be honest your better off removing the tracks altogether and dropping another Via down just like you did for R1 and connecting like that and it looks like you will have to do the same at the other side of the connector :smiley:
:mouse:

1 Like

If you are putting a screw into that mounting hole you will regret routing the pair that close.

I like the through-hole usb-2.0-speed usb-c jack from cui: UJ20-C-H-G-SMT-TR. Don’t need vias to patch the two sides since you have pin pads.

1 Like

Thanks for the reply! I removed that track and added via’s on each side - does this look okay?:

1 Like

Thanks for the reply! I completely missed that so thanks so much for pointing out the issue with the pair and the screw hole. I’ve made much more clearance now

image

Thanks for the suggestion regarding the USB C connector with pins - my only concern is that they’re a bit more expensive than the USB4105-GF-A-120 I was planning to use, and also I’m using a reflow oven to solder the resistors so I was hoping to do the USB connector at the same time

It is tempting though as it would make routing traces much easier for future pcb designs

I have done it for the first time one month ago :slight_smile:

I redefined USB-C symbol and USB-C footprint to have there one pads.

If remember well (have not it here) I connected them without any via. One connection under the socket and second out of socket.

1 Like

That’s a great idea! Thanks I’ll look into doing the same :smiley:

Many thanks for sharing, I hoped I could route them without using vias but I couldn’t find a way to achieve that

Maybe this helps you: GitHub - TimGoll/kicad_libs

I use this footprint and receptacle for my designs. I don’t need the full USB/Thunderbolt feature set. Powerdelivery and USB 2.0 are enough for me.

Yes, looks great and feels correct as well :smiley:Keep up the good work :ok_hand:
:mouse:

1 Like

First off, thanks Tim for posting your footprints and models – some of those look handy.

However, I have had problems with usb jacks (or any jack that is for external cable connection) that are only smt. I have had more than one of them sheared off the board during normal use when the wimpy smt solder joints fail. Sometimes it can be repaired and sometimes traces get peeled off and it is a total loss. You can mitigate it somewhat by manually reflowing a bigger solder blob on the four mounting pads, but just factory smt soldering via reflow leads to a weak connector. The jacks with through-hole frame pins (the signal pins can still be smt) are superior mechanically.

It is a real bummer for a product (I know from personal experience); not so bad for a one-off in-house design. I now avoid smt-only jacks for anything where the big beastly monkey on the outside of the box can impart shear and torque loads to the plug when connecting cables. Just a cautionary tale fwiw.

I think you can make this socket being stronger if you add via in S1 pads (may be 4 in each). Next only smd sockets can be used if force is not going through socket to PCB. If socket is only seen in the case hole and has some case support at its back and PCB is loose in the housing then I would not expect big problems with it.

1 Like

Right there with you on through hole for jacks if at all possible.
A lot of the stuff I create is used by First Responders. They can break a 152mm (6 inch) round stainless steel ball with a rubber hammer.
The extra cost of the connector and assembly costs is nothing compared to the cost of a field failure.

Thanks for your reply. You are probably right for consumer products. But the stuff I design is mostly used in house or for debugging stuff etc. One thing though: I tend to add a “shield copper pour” so that the shield pads don’t shear off too easy.

Bigger pour on the shield makes sense, I’ll park that idea away for future use should I do an all surface mount connector. Tnx !

1 Like

Drop the vias on the data lines altogether, no need for them:

1 Like