What makes a circiuit "professional"?

Discussion in 'General Electronics Chat' started by magnet18, Feb 16, 2013.

  1. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    So just wondering, what exactly makes a schematic, or more particularly a PCB, look professional?
    The routing of the traces?
    a logo and copyright symbol?
    is there a real difference?

    I'm curious of your thoughts
     
  2. #12

    Expert

    Nov 30, 2010
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    Uniformity. Some of the crap I've made with a resist pen wouldn't be allowed in a "real" product.
     
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  3. strantor

    AAC Fanatic!

    Oct 3, 2010
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    exhaustive testing and verified compliance with standards, with certs to back it up?

    ("?" because I'm not positive, but pretty sure.)
     
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    Uniformity, silkscreen not created with White Out, Silkscreen on both sides if applicable, solder mask, all signal traces the same width and parallel, traces on opposite sides of boards perpendicular in 'flavor' of orientation (L-R on bottom, Top-Bottom tendency on top).
    *breathe*
    Holes the correct size rather than "My PCB Bit", rounded corners (not much, but just a touch), mounting holes, contiguous ground plane fill if possible, components mounted equal distance above board for each type. Connectors play a Large Role in "looking good with style". Putting in Test Points if you have them and room for a few, at Least put a ground clip TP for scope/logic analyzer. Same style of headers/connectors for each type of signal, no wires simply soldered on where they go.

    Take apart a $49 200W no-name stereo and examine the PC Board. Do the same with a Yamaha High end unit (or watch YouTube teardown vids of same).

    Basically, if it breaks, can somebody with a bit of experience take it apart and identify the different "sections" of the circuit? The power supply shouldn't be spread across the board (unless the board is the power supply...). For digital, SMD bypass caps on the bottom side are both more effective and keep the top side looking clean.

    Label I/O connectors. Labeling (silkscreen) and making it easy to follow (layout) are the big things. Connectors are next so the board can be removed without desoldering. Always use different color wires for connections that Must be soldered so there is no confusion. Same for jacks and connectors, unless they can only fit one way.

    Those are just a few ideas, I'm sure I left out some big ones, and didn't cover 4 layer at all. Everything you do when laying it out, think "If this breaks and I can't find the schematic, would I be able to fix it?"

    A nice touch is a schematic inside the enclosure. For smaller projects, a $1 USB Flash drive that has the schematics in PDF and Gerber formats, Bill of Materials, and Source Code (if released, and system uses one or more).

    --ETA: If going mass production, several self-destruct moisture dots and heat dots.
     
  5. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    [​IMG]

    Easy to tell the differences, isn't it? :D
     
  6. takao21203

    Distinguished Member

    Apr 28, 2012
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    Screw terminals make life more easy. Even on prototype circuits.

    Space out circuits.

    Use up to modern standards components.

    Use low current LEDs.

    Don't overdimensionate components (large capacitors),
    and remove components which are not needed.

    Most low frequency circuits are perfectly fine with just one bulk capacitor.

    You can use larger capacitor often small cheap 1uF capacitors are totally enough. Or use 4.7uF ceramic.

    For a non-production circuit 1206 SMD is OK. Or 1/8W resistors.

    Don't label unimportant components with value.

    There is always a lot of work that can be done to make a PCB looking better.
     
  7. PackratKing

    Well-Known Member

    Jul 13, 2008
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    That's your work on the left ??? Nice !!
     
  8. MrChips

    Moderator

    Oct 2, 2009
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    What makes a circuit professional?

    I thought it was when you get paid for creating it, i.e. you make a living from it.
     
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  9. takao21203

    Distinguished Member

    Apr 28, 2012
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    Good performance for many years.

    Inexperienced designers may choose components which are a match nominally, but then after only some months, they start to fail.

    Professionalism includes many aspects- the long time relieability the most obvious factor.

    Years of experience as well.

    Cosmetic aspects for some folks as well- and of course important when you want to market it.

    Think if somebody 20 years later sees these orange Panasonic adjustable resistors on your PCB- and reports they still look like new, and work 100%. Or if they report rust and corrosion and discoloured stuff.

    The nominal service life is only a few years for consumer goods- be it by design, or the need to upgrade to the latest technology.

    I saw commercial PCBs which were anything but professional.

    You simply need some sense for good quality, and ambition, and experience with failures.

    A really professional circuit may require months of testing, and a series of prototypes. Where you also can use just one, and good quality components, and hope for the best. Many circuits use component values far more than actually needed.

    What fails first is often pushbuttons- even for expensive consumer goods they save 1 cent or two cents here. And battery doors will break off after a few months, SD card sockets will wear out. As I say, anything but professional.

    What I never use and dislike are DC jacks + sockets, not only a mess, over the years the plugs will wear out, as well the silver coated sockets will oxydize. Can happen in a matter of months.
     
  10. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    LOL. ;)

    No, it's been many years since I last made my PCBs at home....
     
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