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Feedback on creating circuit boards

Discussion in 'General Electronics Discussion' started by oyvdahl, Oct 11, 2012.

  1. oyvdahl

    oyvdahl

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    Oct 11, 2012
    Hi everyone
    I am in the process of creating a website where my aim is to teach hobbyists how to create circuit boards. It is at http://www.build-electronic-circuits.com/

    As it is hard to evaluate my own work, I would love it if any of you could spare a few minutes and give me some feedback. What information are you missing? Do you see any obvious mistakes on my part? What would you love to read about (within the context of creating circuit boards)?


    All the best,
    Oyvind
     
    Last edited: Oct 11, 2012
  2. CocaCola

    CocaCola

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    My advice is if you want to use that domain for your website you should purchase said domain name as it's not currently registered and thus the link goes absolutely nowhere...
     
  3. oyvdahl

    oyvdahl

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    Oct 11, 2012
  4. docb

    docb

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    I think it's quite good - I even learned a new tip! ("run length")
     
  5. oyvdahl

    oyvdahl

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    Oct 11, 2012
    Cool! :)
     
  6. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

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    Deserves a Sticky or placed in the Awards thread.

    oyvdahl, I want to commend you for not only the content of your website but also its structure and layout. You did a fine job there. After I post this I'm emailing my geek circle with a link to this thread.

    Chris
     
  7. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

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    Nice work oyvdahl. You've created a resource that will be helpful for beginners, to show them that you CAN do a lot with free tools.

    I could write pages on PCB layout considerations, but I'll spare you most of the boredom.

    Sometimes beginners have trouble with selecting appropriate components. Capacitors are a good example. Often they're just specified as "10uF/25V" or something like that; the beginner needs to know to use a standard electrolytic, or a ceramic capacitor for decoupling, and so on.

    You have to assume that anyone designing a circuit that needs components with special characteristics such as low ESR, or a heatsink attached, for exampe, will clearly mark the relevant components, but that's not always the case. Also, the layout person needs to know how to place and route decoupling capacitors so they will be effective; often these capacitors are shown in a clump in a corner of the diagram, or vaguely positioned near the applicable IC.

    Some designs require component construction - e.g. inductor winding.

    Perhaps you could do a few detailed case studies, starting with a sparse schematic that uses a variety of special cases like these, and explaining component choice and any other decisions that must be made in the process of converting a schematic into a layout.

    For double-sided PCBs, with larger designs especially, it can be helpful to use layer biasing - that is, most of the tracks on the underside are horizontal (for example) and most on the top layer are vertical. You may have covered this already; my apologies if so.

    Finally, I personally would use tracks thicker than 12 thou, except in dense areas such as buses. Although modern PCB houses can easily make reliable PCBs with tracks of 8 thou and less, these are more vulnerable to damage from scratches or being lifted along with pads during the rework that often happens during experimentation.

    For single-sided boards especially, I often use 15 thou tracks on a 25 thou grid, giving 10 thou clearances. If the layout is sparse, and capacitance is not important, you can use thicker tracks; between nearby pads, I often use a track thickness equal to the pad diameter, especially on single-sided boards.

    Edit: a "thou" is a thousandth of an inch; many people use "mil" to mean thousandth of an inch (for "milli-inch" I guess) but I avoid "mil" since it's easily confused with millimetre.
     
    Last edited: Oct 13, 2012
  8. CocaCola

    CocaCola

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    I agree, I generally start with 20mil signal and 30-40mil power traces and see how that goes, it's easy enough to change on the fly in modern software... Turn on auto-bottle necking if your software supports it and you can even push the fatter overall traces further... The trace width = pad width is something I generally do for more dense SMD ICs, it makes for a clean look...

    It's a pet peeve of mine to see skinny traces used on a board when there is plenty of room and no reason not to use good fat ones...
     
  9. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

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    Yeah, and fat ones tolerate soldering iron heat better than skinny ones.

    Chris
     
  10. oyvdahl

    oyvdahl

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    Oct 11, 2012
    Thanks for all your suggestions guys!
    I'll read your posts again a few times, then see if I can write a few articles based on your input.
     
  11. rob_croxford

    rob_croxford

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    Great site and well laid out.

    I would like to see advancements in your "how to solder" section. For instance:
    - Examples of good and bad joints for both through hole and SMD (pictures)
    - Greater detail on reflow construction. I have used this method at home and i know of a few other people who have also done such work. The main issues i found were with setting and maintating a temperature profile that worked for all components. Perhaps more detail could be aimed at this section
    - I am personally not a fan of your "flood with solder technique" although i am sure it is a viable method of soldering SMD components i feel that over heating would occur to easily and you may have bad solder joints because of heating and reheating the solder. Perhaps you could add a word of warning for this method?
    - Perhaps a descussion on types of solder? Certainly for leaded and unleaded.

    This is all i have for now. Sorry if i have missed parts that you have included.

    Good site.

    Rob
     
  12. oyvdahl

    oyvdahl

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    Oct 11, 2012
    Thanks for you suggestions Rob!

    About reflow soldering temperature profile, what problems are you experiencing?

    Oyvind
     
  13. CocaCola

    CocaCola

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    It's a viable way to do it, like any method you can overheat a chip... I personally don't see any increased chance of overheating as long as you practice the technique and don't cook the chip with overworking... Also the flood method can and does produce real nice joints, even more so if you hit it with some flux before the final pass... I use this technique a lot when I'm touching up fine pitch high pin count chips...

    The profile should follow the paste being used as defined in the paste datasheet, although strict adherence to the written profiles is a little hard for most DIY reflow ovens, many times the DIY has to improvise and find what works for their particular oven...
     
  14. rob_croxford

    rob_croxford

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    Aug 3, 2010
    I have also used this method and i have also damaged a chip because of it. I understand it is a viable method i was simply suggesting a word of warning to hobbyists who may not be familiar with soldering and could damage chips or circuit boards. That is all.

    As for reflow - once again just a word of warning that putting anything into an oven can damage it.

    I was under the impression that the site was designed for people who may not be proffesionals and who are hoping to learn not only how to perform a certain task but also to be warned of the dangers of performing said task. If i am wrong in thinking this then i appologise.
     
  15. CocaCola

    CocaCola

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    To suggest that the warning is only applicable to one or two techniques that you might have had issues with is silly, it's a universal rule... Any and all methods pose a risk of damage to the component and/or board if done improperly... An inexperienced person can lift a pad in a split second with an iron no matter what technique they are trying to use, in fact I would hazard to say more newbies destroy boards and parts by simply overheating an overworking trying to do regular single point solder joint then any of the fancier methods...

    Yes putting things in ovens can damage them, but any part designed to be reflowed is also designed to tolerate the heat of reflowing... The risk of damage is minimal to nil if done properly...

    Again a universal warning it more applicable...
     
  16. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

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    Rob, we should have a an official name for what you're experiencing here. It's not unique to EP, as you will experience this on any tech site, even programming forums. I think I'll coin it "The Verbiage Pit" because you'll usually spend at least the next 6 posts clawing your way out with,.... "but all I meant to say was...", or "That's not exactly what I was trying to say" or, "If you re-read that you will see that I didn't say......". All of which will undoubtedly prove to be quite futile.

    Electronics is an exacting science that breeds exacting people that use exacting verbiage. I, on the other hand, do not suffer from this affliction. :rolleyes: :p

    Chris
     
  17. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    That should be 2 spaces after the full stop. :D
     
  18. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

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    May 8, 2012
  19. CocaCola

    CocaCola

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    But, the confusion of that thread was compounded by the fact that you linked to a faulty reference circuit, a faulty reference circuit that was transcribed in the same incorrect manner by another member and thus posed a new potential issue being discussed that really didn't exist...

    I know you know full well how to do it, and the correct way had been documented multiple times in that thread, but as I said earlier the thread had come full 360 and was right back at square one as if nobody was reading...

    But, whatever...
     
  20. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

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    I get that. It's just the different ways that each of us approach things. If it were you that missed the fact that diode's anode wasn't connected to the low side of the coil I would have said "CC better have another peek at the OP's schematic. You missed something". ;)

    Hey, this is meant as light hearted humor to help explain and avoid the Verbiage Pit. :D

    Chris
     
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