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I would like to make a board which can be plugged directly into the USB port of a computer, instead of using a separate male "USB-A" connector. I have seen this system used for very small USB memory keys, such as this one. How would I lay out a PCB with such a "connector" built in?

I am using Eagle. Does anyone have a library for it? Can anyone suggest another way to do this?

drxzcl
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2 Answers2

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The Sparkfun Eagle Library (pre-6.0, 6.0+) has one. It's called "USBPCB".

Here's a project using it.

Community
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Toby Jaffey
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  • You are right! It was staring me right in the face. Thanks bunches, the eagle library system can be annoying at times. – drxzcl Apr 17 '11 at 20:13
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    BTW, do you have any idea what the proper PCB thickness would be? It looks like it's at least 1mm, maybe more. – drxzcl Apr 18 '11 at 22:41
  • I'm not sure, I'd suggest contacting the author of the GoodFET project I posted – Toby Jaffey Apr 19 '11 at 07:54
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    Btw I emailed Travis of GoodFET fame. He said that the GF31 is produced on a board with a thickness of 0.078". He also suggested to round up when performing metric conversion to 2mm. – drxzcl Apr 20 '11 at 20:56
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    @drxzc - For prototypes, I would err on the side of thinner PCB, and if needed, simply add some tape on the back-side to make it thicker. That way, you're going to get *something* that will work. – Connor Wolf Oct 29 '12 at 03:06
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    @drxzcl 1.6mm is what you generally get if you don't specifically ask for something else. – Chintalagiri Shashank May 13 '13 at 13:18
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For reference: I tried the SparkFun footprint one on a 2mm thick board, the result was unsatisfying: the connectors on PCB oxidized and the connection was faulty, I didn't get the problem right away, but such bizarre things as the computer recognizing my FT230X chip (Serial adapter) as a Microsoft Ballpoint Mouse and the computer mouse begun to jump everywhere and click randomly (very annoying). Once I scraped the metal it worked very well again, so no deal, get a proper connector.

Solenoid
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    It would work fine if you had the PCB properly gold-plated. I don't think anyone would think that the tinned board surface is really reliable over any sort of timeframe. – Connor Wolf May 13 '13 at 09:41
  • @Connor Wolf: absolutely, but PCB houses do not offer such services and one can much less do it at home, but it's how connectors should be made. This was a noob experiment since I haven't found anything beyond theory on the net, I sacrificed some of my time to confirm it. It's usable, but be careful. – Solenoid May 13 '13 at 14:05
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    What bizarre PCB house are you using? Pretty much every PCB house I have ever looked at offer gold-plating. It's not free, but I bet even the PCB house you use can gold-plate your board. Ask them! – Connor Wolf May 14 '13 at 03:53
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    @Connor Wolf: Then I learned something new today, I'm completely self taught when it comes to PCB making so information isn't easy to come by. – Solenoid May 16 '13 at 12:37
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    Most board-houses (any decent one, anyways) will have a big list of all the stuff they can do. Read it! Or better yet, read the documentation from several different board houses, and compare and contrast it. You can infer a lot about the ease and mechanics of making boards that way. – Connor Wolf May 17 '13 at 02:39
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    Not only it's easy to do gold plating at home (you buy off-the-shelf chemical kits for it), but many PCB houses do in fact offer it even for small quantities. – Kuba hasn't forgotten Monica Jan 03 '14 at 17:38
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    OSHPark do gold plating for free. You only get one thickness though (1.6 mm) which doesn't seem to be enough. Perhaps a small piece of shim metal could be soldered to the opposite side to make it thicker? – Timmmm Jun 16 '14 at 13:37
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    "such bizarre things as the computer recognizing my FT230X chip (Serial adapter) as a Microsoft Ballpoint Mouse and the computer mouse begun to jump everywhere and click randomly (very annoying)" are a software problem, and provide absolutely zero evidence of any circuit misbehavior. Simply go into the serial port properties in Device Manager and disable "Serial Enumeration". On newer chip/driver combinations (including yours) you can set a bit using FT_Prog such that the driver won't install `serenum.sys` in the first place, thus saving you the step of turning it off. – Ben Voigt Jan 14 '16 at 16:01
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    It should be noted that even commercial caseless usb plugs tend to be very iffy when it comes to working properly if plugged in and out a lot. gold plated or not. – Lassi Kinnunen Jan 03 '20 at 15:06