First PCB, Nixie clock

Discussion in 'The Projects Forum' started by magnet18, Aug 14, 2011.

  1. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Alright, I'm in the process of making a PCB for the nixie clock, and I was wondering if I could upload it to be looked at to make sure I'm not violating any crucial rules of PCB making like trace size or anything... unfortunately I'm not sure how to even get it into a file format that I can upload on here so that people can look at it :confused:

    I'm using express PCB to lay it out, if anyone knows how to get it into a good format I'd be very thankful, if not I'll just resort to a few screenshots.
     
  2. SgtWookie

    Expert

    Jul 17, 2007
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    Download/install 7-zip, and zip up your .sch and .brd files into a .zip file, then attach the .zip file to a post. You should also load your board, and do a Ctrl+PrtScreen, and paste the image into MS Paint, and save it as a .png file for uploading.
     
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  3. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Thanks, I uploaded the green (bottom) and red (top) separately, and I zipped the .pcb file and included it also.
     
    Last edited: Aug 15, 2011
  4. SgtWookie

    Expert

    Jul 17, 2007
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    You should have included the schematic in the .zip as well.

    You could keep that 180V trace further away from the low voltage stuff. You should consider putting a ground trace as a guard between the HV trace and the logic side; otherwise if carbon tracks start forming, your logic ICs will get wiped out. On the bottom, you have traces run much too close to the HV; give them some breathing room.

    I don't like to have pads in the middle of a trace; it makes it harder to solder components to it, as the trace acts as a conductor of heat. It makes it much more likely that you will apply too much heat with the iron in one spot, and the trace will lift from the board, ruining it. Use a long trace as a bus, but place your component pads offset from the "thru" trace, connecting the pad to the bus using a short trace.

    You don't have to have the traces running only horizontally or vertically; that will make runs longer than necessary. It's OK to use even multiples of 45°. Avoid odd angles wherever possible; if you have to make very short runs at odd angles then that's the way it is - but try to not do that.

    [eta]
    Here, I did a bit of "tweaking" on just the bottom side of the left two Nixie tube connections. I gave a good bit more clearance around the HV connections, and made the runs shorter by changing all the sharp 90° bends to pairs of 45's. Have a look.
     
    Last edited: Aug 15, 2011
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  5. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Alright, I modified mine a bit, but I just saw you're attachment and I'm gonna change it to what you did, it looks a good bit better than mine :rolleyes:


    will do, soon

    like what I attached?

    Are you referring to the 180V trace, or are there other locations where I did that?

    Thanks!
    I think I'll change mine to that, it looks much better.
     
    Last edited: Aug 15, 2011
  6. SgtWookie

    Expert

    Jul 17, 2007
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    I started doing this kind of thing a few weeks before you did. ;)

    Don't get discouraged. At this point, your project is smoke-free. :) It would be a lot more discouraging if you had completed it and ran into trouble. :(

    Keep in mind that sharp corners will tend to emit electrons, just like a spark gap. You really don't want any sharp corners in your HV traces if you can avoid them. Remember the earlier discussion about leaving sharp points on your HV connections? Wire ends at connection points? Well, it's the same thing here.
     
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  7. SgtWookie

    Expert

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    re: attaching schematic:
    Good. :)

    I haven't looked at them yet.
    [eta]
    I looked at them, but you could certainly have more space if you follow what I did.

    Yes, and any other locations where you have pads in the middle of a trace. I have not looked at your layout in great detail, but I did notice the HV bus.

    Re: my attached layout modifications:
    It's not just "how it looks"; there is much more space available, particularly around the HV connections, and the traces have been shortened due to the use of 45° angles rather than all 90° angles. Note also that I ran one of the traces between a transistors' pads to enable the re-routing of one of the traces on the right side of the right-hand Nixie; it was just too close to the HV supply.

    [eta]
    I noticed that your "minutes" and "hours" switches up on top are not connected to anything - did you plan on running long jumpers instead of traces?
     
    Last edited: Aug 15, 2011
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  8. TBayBoy

    Member

    May 25, 2011
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    I'm learning this stuff also, good info, on the top trace, are you planning to put something like "Nixie clock designed by me"
     
  9. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    I've worked with ExpressPCB many times and they are very good at making you a few boards. They are not competative when it comes to production quantities as they are set up to make only small runs.

    The only disadvantage to using them is you do not get gerbers from your work to go to another house. They will sell you the gerbers once you have boards made there, they charge you basically another board manufacturing fee.
     
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  10. GetDeviceInfo

    Senior Member

    Jun 7, 2009
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    personally, I'd break all your 90 degree turns into 45s. Hard corners don't etch well. Your device pads (drilled) should have more meat.
     
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  11. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Alright, this one should have both the final schematic and also the pcb

    Hey, I've been doing this since... thursday...

    Yea, carona losses and whatnot.
    It's only 180V, and it's positive, so I'm not too worried about it, but I'm giving it care anyway

    Kk


    That's what I meant by "looks better" :rolleyes::p

    not sure yet, I'm still considering putting the switches on the second board that will slide in underneath this one in the clock and house all the logic gates and features and whatnot, but for the time being, yes, I was just going to run jumpers.
    I may incorporate some sort of switch de-bounce.
    Are jumpers taboo?

    It will be on there somewhere ;)

    *estimate cost for board*
    $115
    *jaw hits desk*
    0.o
    Ima be etchin' this by my self

    Thanks, by device pads you mean the ic pads?
     
  12. SgtWookie

    Expert

    Jul 17, 2007
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    You will have a heck of a time trying to get both sides of a board's traces to line up.

    If you are going to make your own boards, you may be better off to try doing the vast majority of your routing on the underside of the board, and simply use jumpers on the top. That way you'll avoid having to try to align stuff, and also won't have to worry about trying to thru-plate your pads/vias.
     
  13. nerdegutta

    Moderator

    Dec 15, 2009
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    I've made a few double sided boards. I'm using UV LEDs. My current setup allows me only to expose one side at the time. The hardest part is to align the two layers. I made a "pocket" with the transparent sheets, and laid the PCB inside it. A little trick is to make a border around both layers, at the same place. For vias, I used cut-offs from resistors and capacitors. Once I tried the legs of an DIL socket, but that was not successful.

    This is one of my boards:
    [​IMG]
     
  14. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    that sounds a lot more complex as far as routing goes...

    Would it be easier if I was to drill a few refrence holes?
    or etch one side, then drill holes, then etch the other?

    good idea!
     
  15. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Alright, to what degree of betterness or worseness is this??
     
  16. Markd77

    Senior Member

    Sep 7, 2009
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    I'm pretty sure you want to expose both sides then etch, I'm not sure how well that black plastic film handles etchant.
    I'd drill 2 holes at opposite corners before anything else and use them for alignment.
     
  17. nerdegutta

    Moderator

    Dec 15, 2009
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    How will you transfer the traces to the PCB?
     
  18. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Sorry this took so long to reply, school started and I've been working on a tesla coil so this kinda got overlooked.

    Anywho, after contemplating it, and considering, and mulling it through and stirring it about and chewing it over and making some money, I decided I would have the boards mad, and make like 20 of them, since the first one costs 100 something dollars and each after that is like 2 bucks, and sell kits &/or complete clocks to make some money (if you're interested, PM me)

    so, does the above pcb look good?
     
  19. SgtWookie

    Expert

    Jul 17, 2007
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    Looks better. I simply don't have the time nor energy to go over it in detail. Nothing is documented, and the schematic isn't in ExpressSch, so I don't have an automatic way to perform rule checks and wire checks.
     
  20. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    I know, I don't expect anyone to look over it trace by trace, I was just making sure there wasn't anything like the corrections you made in the HV trace being so close to the other stuff, or anything obvious.

    Thanks for all the help thus far!
     
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