I think PCB review questions like "Here's my PCB, can anyone tell me if my [layout/vias/placement/whatever] is good?" are not a good fit for the site.

That said, are there any sites that do PCB review/consulting work inexpensively or for hobbyists?

If not, just as StackOverflow has CodeReview, I wonder if anything related to schematic/PCB review would be a worthwhile endeavor, or just a colossal waste of time. Thoughts?

Design Review is the name I am used to, and as with a code review, it can be used for schematics/PCBs and all of your design output. –  Kortuk Dec 5 '12 at 15:23
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4 Answers

up vote 20 down vote accepted

We have had a number of questions like that here in the past, and I haven't considered them beyond our scope. Yes you could make a case for them being too localized, but some good discussions have been generated.

I guess it depends on how exactly the question is asked. If someone just dumps a layout on us and expects a general design review, that's probably not appropriate. But, the same layout with more specific questions like "should these grounds all have separate vias like this, or is it better to connect close ones and use a single via?" seems within our scope to me. A example of the latter is Decoupling caps, PCB layout, which got lots of upvotes and my answer also got lots of upvotes.

Yes, the second question is a specific technical question with an example, the idea of here is my project, design review time is very localized and often leads to repeating questions as they update and just ask again. A design review site makes sense to me just as codereview mades sense for SO, but I do not think we are at critical mass to support such an endeavor yet. –  Kortuk Dec 5 '12 at 15:22
Thank you for the insight. I'd considered putting part of my board design up for someone to look at, because as a beginner I am unsure about a lot of things. Perhaps I will isolate a good, non-localized technical question about it and post. –  JYelton Dec 5 '12 at 17:43
Perhaps we can incorporate this with a "DesignReview" tag? –  trayres Dec 14 '12 at 11:50
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As long as it's not, as Olin said, "dumping the layout on us", it should be fine. The example you gave isn't that bad because it's at least asking about a specific thing about their layout, although a little more specific would certainly be nice. A bad question would be "Does anything look wrong here?". Keep it specific enough that the question includes few, if any "how about now?" updates. Any such updates must be very clearly marked and the original layout should be kept in the question for future reference.

We're not really big enough to support a second Design Review site, maybe a design-review tag would be a good idea if there isn't one already. Edit: Apparently meta tags like design-review are explicitly discouraged due to their subjective meaning. That being the case, nudging the question towards specific topics is even more important.

In the interest of having design review questions be as specific and answerable as possible, I offer some guidelines for asking a good PCB design review question. Some of these are good practice in general, but are even more important when trying to ask a useful design review question.

Help us help you (what are we looking at?)

  • Show the layout in the most useful format your project allows (don't get fired). Design files or Gerbers are best if possible. Layout screenshots should be fairly high resolution and annotated enough to make up for not being design files.
  • Include a schematic of the relevant portions of the board. Label nets in the layout accordingly. Nobody should have to guess at what kind of traces they're looking at.
  • All components should have reference designators. Use them in your question.
  • What are the relevant capabilities of your fabrication/assembly companies? What soldering method is being used?
  • Include a size reference of some sort in the layout if necessary (usually a grid).

Narrowing question scope

  • If your question is about a specific part of the layout, highlight/explain where it is or crop screenshots accordingly (depending on how the layout is presented in the question).
  • Highlight specific components/traces/pours that you are concerned about.

Examples of topics to ask about

This is not an exhaustive list. As a general rule, questions should have more tags than just a hypothetical design-review tag because you want a second opinion about some specific issue.

  • Reference (power/ground) planes
    • Multi-layer stackups
    • Connection of analog and digital reference planes
    • Best practices for vias to power/ground planes
  • EMI/EMC/noise immunity and related grounding issues
    • Guard rings/traces
    • Crosstalk
    • Unintentional antenna loops
    • Sensitive signals (analog or high-speed digital)
    • Transmission lines
    • Ground return paths
  • Component placement
    • Component spacing for manufacturability
    • Decoupling capacitor placement
  • Thermals/heatsinking
    • Hotspots
    • Thermal reliefs
    • Connection of IC thermal pads to copper heatsinking pours
    • Trace width
+1 I think the list is a good example of how many different things a "simple" PCB layout question can involve. If the OP indicates which parts he/she has trouble dealing with or understanding, then it would be easier to focus and provide more helpful answers. –  Oli Glaser Jan 7 '13 at 2:13
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I wonder if we could add a list similar to that in Joe's answer in the FAQ or under the "PCB" tag, which could provide advice on how to ask these types of question.

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The PCB shouldn't be auto-routed (at least, not excessively) to be eligible for the review here. May be, we should add it to this unofficial policy.

Here's a thread, which is an unsuccessful test case. Unfortunately, the O.P. there have fully auto-routed his very-first layout. In addition, the schematic wasn't posted. Reviewing that doesn't make a lot of sense. We don't even know what the auto-router settings were.

The question you link to is inappropriate because it just dumped a layout on us. The layout was fairly large, no specific question was asked, and there wasn't even a schematic provided. –  Olin Lathrop Jun 17 '13 at 12:46
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