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PCB Edge USB C Connector Library
- 15155 1y agoWhat PCB thickness is optimal? The USB-C tongue on a shieldless part I use is ~0.7mm, which is a pretty thin PCB.
- webdevver 1y agoi wonder how often you can plug/replug the connector in this case. how will the pcb material hold up? with my press-fit or clip-fit (is that a term?) 3d prints, ive noticed that 20 cycles can be sufficient to induce substantial 'loosening'.
- ggm-at-algebras 1y agoPlug an OTG cable in and connect to that, so you don't repeat plug-unplug?
- eternityforest 1y agoWhat about the force transferred by the connector wiggling? I think You'd need a very good mechanical design on the case to make it all work.
- Kirby64 1y agoIt’s likely in the order of 10-30, especially with something like ENIG as a finish. If you wanted more cycles, you’d want to switch to a hard gold finish which would likely increase the cost substantially. This is truly only for a debug port, not anything else.
- AnasMalas 1y agoI have posted new test results on the github! It did 110 mating cycles without any major issues
- Taniwha 1y agoThey say "use 0.6 mmm" https://x.com/AnasYMalas/status/1982060711670067350 https://x.com/AnasYMalas/status/1982060711670067350
- Taniwha 1y ago+copper+ENIG is going to make that 0.7mm
- peteforde 1y agoThat is a very thin PCB. For anyone reading this, 1.6mm is standard.
- shadowpho 1y agoNo…. It really depends where/what industry/what type/how many layers. I would say 1.6mm is pretty thick but it depends.
- peteforde 1y agoFully agree with the "it depends". FWIW, my slightly more than anecdotal evidence is that 1.6mm is the default thickness at JLCPCB and PCBWay, and they will subtly encourage you to switch to that width if you don't want to pay more or wait longer for them to fill a sheet. Every IC prototype board (eg Proto Advantage) and all of those Adafruit breakout boards are 1.6mm. For these reasons, 1.6mm sure seems like a default if there is one. Is there some JEDEC standard or similar which proves me officially wrong? Happy to learn if so.
- exmadscientist 1y agoIt's not 1.6mm, it's actually 1/16", and it's been the standard since the days of yore. It's a super common inch measurement so it's not really a surprise to see it here, if you know your inches. There's tons of 1/16" plywood, for example. A "thick" PCB was commonly 3/32" (0.093") and a "thin" one 1/32" (0.031"). Now of course it's all made in Asia so the metric dimensions predominate (0.8mm, 1.6mm, 2.4mm), but the legacy remains. And of course PCBs aren't really any of these thicknesses, they're whatever the glass weaves press down to in the lamination press....
- peteforde 1y agoIn a similar vein, I discovered and have started using the Tag-Connect TC2030-USB to program/troubleshoot my boards. While it's technically/originally intended as a way to do JTAG debugging, I am completely enamored with the ability to drop a footprint on my PCB and be able to connect to it without having to place a relatively expensive connector (or a connector at all) that I don't necessarily want users interacting with. https://www.tag-connect.com/solutions-target-devices/usb-serial https://www.tag-connect.com/solutions-target-devices/usb-ser... They have FTDI versions as well, for those who want the full USB boot/reset treatment. Also, they have another connector for attaching to castellated edges. I think it's just so clever.
- Brian_K_White 1y agoI just use ordinary straight pin headers and stagered via holes. The board just has vias and the cable just has a plain pin header not even pogo pins.
- stavros 1y agoWhy vias? So the pins don't go all the way through? Wouldn't any disparity in the lengths of the pins make that pin not touch?
- azdle 1y agoI think they probably mean standard through-holes. It's the old trick where you stagger the holes just enough that the flex of the pinheaders still let's them be inserted, but have just enough friction to stay in place while you're flashing or whatever.
- stavros 1y agoOooh that's a great trick! Thanks, I'll try that on my next board.
- Brian_K_White 1y agoRight, plated through holes, but with almost no exposed anular ring. As little as I can get away with without getting mask sprayed down into the hole. For 100 mil pitch, 25 mil square pins: 36 mil holes, 6 mil off center, 12 mil hole to hole. The short side of a generic pin header is the side that goes in the holes, so the long side is free to accept dupont sockets and shunts the same as if you had the same pins soldered in the pcb. So the cable is just ordinary programmer fly wires with female dupont ends. You don't even need to make an actual cable. If space is tight on the pcb then it does use up more pcb than pads that leave the other side free. And pogo pins are going to be a lot faster for producing something in numbers. I don't mind buying nice stuff like a fancy purpose made good-working tool for myself but I'm always making open source projects and one design goal is to require as little as possible, and as generic and universal as possible from the user. So I avoid fancy special things where possible. It's not designing for commercial production runs nor designing for one-off for myself, it's designing to a kind of a platonic ideal to strip away anything unnecessary and yet try to meet 2 opposing goals at the same time as much as possible: Don't require special tools that make things work reliably because of how fancy the tool is, and don't require the user to be a zen master craftsman that can attain a successful result with rocks and nails. Try to make the process reliable and repeatable while still only requiring basic materials and supplies. As much as possible anyway. Pogo pins are pretty common these days and not exactly exotic or expensive any more so maybe I can start using them. Then again, the through holes do 2 extra things besides make the connection. With pads you need to aim/register the pins to land on the pads, and you need to hold them there. That means aiming with your eyes and holding with at least one hand, or it means adding some kind of extra registration and grabbing features to both the pcb and the cable, like extra drill holes or slots and extra plastic shapes on a special cable-end etc. Or no extra features on the board and instead a whole clamping jig that holds both the board and the pins. Since these are holes that pins go in to, you don't need any other form of registration to aim the pins at the pads. The pins go in the holes. And they hold onto the pins themselves, so you don't need any other form of retention. It's just like plugging a plug into a socket where the socket provides all that naturally. I have one board that needs two different connections like that, one for jtag and one for power and to temporarily close a jumper to write-enable the cpld. So a 4-pin and a 6-pin, 2 different cables in 2 different places. The entire board is slightly smaller than a DIP-28 so no room for any real connectors. You just stick the cables in and two different cables hold themselves with zero hands while you operate the flashing software. The wires are all plain dupont wires stuck on the pins, no solder, and 2 of the pins just have a generic jumper on them. It's completely basic and not-special and works perfect. I have another board that needs 28 pins in a small space. For that one I used 2.0mm pitch pins in straight rows not staggered, but with the holes only 1.7mm apart. In that case it's the long side of the pins that goes into the holes, and the short side is soldered into a programming adapter pcb that goes into a programmer. The pins are in 2 sets of 2x7. Each set of 2x7 has 2 straight rows of 0.72mm holes 1.7mm apart. What happens there is, as the pins start to lean over, the top of the pins hit the opposite side of the hole on the top of the pcb, and don't want to go any further. The pins wedge solid and make 4 points of contact, 2 on bottom and 2 on top, and the board won't go any further even though the pins only just poke out the top and there is still almost 2mm of travel left. So you have a lot of remaining travel to just push a little more if you get a bad connection. It works great and no special parts anywhere.
- JKCalhoun 1y agoThat's cool but I am not sure how a customer of mine would feel if I shipped a board to them like that. (I could see trying it on a project for myself, though.)
- mananaysiempre 1y agoThe problem with USB-C connectors for hobby projects is that they are ass to solder by hand—I’m still looking for one that would use a larger pitch by shorting the four USB pin pairs for either orientation. If you’re shipping something to a customer, I think it’s fair to assume that you don’t really have that problem :)
- exmadscientist 1y agoDo you find the 6-pin charge-only Type-C connectors too small? Or the 16-pin 2.0-only ones? They seem reasonably hand-solder-friendly but I admit I've been fortunate enough to have the factory handling them for me.
- mananaysiempre 1y agoYeah, I find the 16-pin ones a little beyond my skill. They also feel silly—why can’t I have one with just six pins for D±, VBUS, GND, and CC1/2? I guess I could have a factory make a bunch of modules like that for me, but it definitely feels like a thing that should already exist. (There are passive A-to-C adapters, so I see no reason why I couldn’t short pin pairs like that.)
- exmadscientist 1y agoYou cannot do that because of how the connector flips over. (Believe me, I have tried to make it work.)
- mananaysiempre 1y agoCould you clarify? As far as I can tell, GND is A1/B1 and A12/B12, VBUS is A4/B4 and A9/B9, D+ is A6/B6, and D− is A7/B7, and each A pin swaps with its B counterpart when I flip the connector.
- kgasser88 1y ago[flagged]
- shpxbssanmvfphz 1y ago[flagged]
- peterburkimsher 1y agoIf you're interested in other PCB edge connectors, here's an HDMI one I designed: https://forum.kicad.info/t/hdmi-pcb-edge-connector-for-raspberry-pi-pico-dvi-sock/48358/11 https://forum.kicad.info/t/hdmi-pcb-edge-connector-for-raspb...
- geepytee 1y agoVery clever packaging of a connector
- izonu 1y agoHere is a similar project in the sense that it uses no connectors on the PCBs, using a SOIC-8 clip to bite into the board. I think it's pretty clever. https://github.com/SimonMerrett/SOICbite/ https://github.com/SimonMerrett/SOICbite/
- dvh 1y agoDoesn't it require ENIG? I wanted edge connector for my pcb project but it adds $20 to the price of pcb, that's just too much. Anyone knows card edge alternative? I'm thinking pin header but that's not very user friendly. Edge card can be inserted blindly even if you don't see the connector, pin header would probably just bend irl.
- the__alchemist 1y agoENIG sounds expensive right? Double the cost of your board or w/e? IMO it's no big deal because:: - A: If you want a 6 or more layer board at some places, you have to get ENIG anyway, and solving routing puzzles isn't my idea of fun. - B: The PCB price is a small portion of the overall price anyway; parts and SMT dominate. So you're paying 2x as much on 15% of the total or w/e.
- sagarm 1y agoEh for a hobbyist it's simpler and more robust to just put a connector on the board or use a test clip. I use clips like these: https://www.aliexpress.com/item/1005007622121847.html https://www.aliexpress.com/item/1005007622121847.html You can choose your spacing: 1, 1.5, 2, or 2.54mm.
- mrheosuper 1y agothe only people who gonna use this footprint is hobbists, and they care a lot about cost.
- stavros 1y ago> solving routing puzzles isn't my idea of fun. This just illustrates how different people are: I sometimes make PCBs just to route them! It's by far the most fun part for me.
- tuetuopay 1y agoI've done HDMI edge connectors like this using plain HASL without too much trouble. Just don't forget to remove all soldermask on the connector path, they'll dirty out quickly otherwise. But, now I do ENIG everywhere because it's often the same price as lead-free HASL (or so close it does not matter), while looking way cooler. I've started to take quite seriously leaded stuff now, especially since low temperature lead-free solder exists (SAC305).
- Velocifyer 1y agoI was looking for this for a while!
- the__alchemist 1y agoThis is very cool! What is the practical intent, given USB ports are 69c each? To save vertical space? I am thinking: Neat this is elegant and would work! But I can't think of any scenarios (off-the-cuff.) where I would choose this.
- user_7832 1y agoI have no idea how easy it is to implement this in KiCAD, but if it is - prototyping with this can be faster if you're eg making something like a DIY keyboard. Fewer things to solder, which is very nice if you struggle with it.
- AnasMalas 1y agoIt is as easy as 123, just a couple of clicks, and its all explained on the GitHub. However, unless you're committing to a 0.6 mm PCB, I wouldn't really use this on a keyboard, especially a full size one. The board really is not rigid at those sizes at that thickness. Weigh a tradeoffs and use it if it works for you!
- AnasMalas 1y agoI made it for a business card, the whole card, PCB and components together, is 1.6 mm thick! That was my motivation for this
- userbinator 1y agoThere are USB-A drives which do this, and in my experience they are far less durable than ones which have an actual connector. Given the thinness, this is going to be too easily snapped off.
- kaoD 1y agoI mostly use these for prototyping. Even gold-coated fingers still suffer from abrasion after many inserts so there is no way these are durable.
- AnasMalas 1y agoThanks for posting this! I have now updated the GitHub with test results for durability and to test PD capability. Have a look if you're considering using this!