DIY: PCB layout tools

PCB

Update [2012-01-05]: WinQcad hasn’t been updated since May of 2011, and email enquiries to its author (who has always been very responsive to me) are going unanswered. For these reasons, I can no longer recommend it. I really hope the situation is a temporary one.

Because of the situation with WinQcad, I decided a few months ago to adopt KiCad as my primary PCB design tool. My reasons for choosing KiCad include:

  1. It’s free and open source software and enormously popular–meaning that it’s not likely to go away or suffer from midstream licensing changes.
  2. It works well on Linux (my main OS for several years now) as well as Windows. It’s reported to work on OS X as well.

It’s main drawback (for me) is the lack of a really good autorouter. The built-in one isn’t that useful. Many people use the Freerouting.net router, but (a) it hasn’t been updated in quite a while–leaving its future status in doubt and (b) unlike KiCad itself it’s not FOSS (though it is gratis). There is a project underway to build a standalone autorouter that is compatible with KiCad, and I hope this project succeeds.

I am also using gerbv a lot for inspecting Gerber files. gerbv is part of the gEDA initiative.

I am currently working on laying out a printed circuit board for a client that is pretty dense (the board, that is, not the client). I don’t make a living off PCB layout work, so it doesn’t make sense for me to buy a mega-thousand dollar package like those offered by Cadence, Mentor Graphics, Pulsonix and the like. However, the boards I do can be fairly complex and so require pretty decent tools to support the process.

Fortunately, there are a number of low cost and open source tools that can be used to obtain professional results. (Check here for a comprehensive list of cheap and not-so-cheap tools.) A bunch of years ago, I went through a round of evaluating them, and I eventually settled on a little-known package called WinQcad. More recently, I decided to use my current project as an opportunity to re-evaluate some of the latest offerings, and the conclusion that I reached is that still nothing beats WinQcad.

Like most PCB development tools, WinQcad has a pretty steep learning curve, but it makes the entire process of schematic capture through generating production files at least as simple as any of the other solutions. However, the real deal-clincher for WinQcad is that it has hands-down the best autorouter of the bunch. Most of the autorouters I have tried fail to route even fairly simple boards, and when they succeed, they often make some very “interesting” routing decisions. In contrast, I have yet to encounter a design that WinQcad’s autorouter couldn’t handle and do a good job of as well. I can’t begin to tell you how much time and stress WinQcad’s autorouter has saved me.

You can download a free pin-limited version for small projects or evaluation purposes, and a 1000 pin license costs only $300. Highly recommended.

While WinQcad has a large library of parts and land patterns, in many cases you may still need to develop your own. To help you with this, the IPC and PCB Libraries, Inc. offer a free program that contains full specifications for standard IPC-7351A land patterns. This program is part of a larger suite sold by PCB Libraries that has all sorts of other things to help you develop land patterns; but if you are patient and are working with standard packages, this freebie will serve you well. PCB Libraries makes another subset of the suite available for free as well to help you with non-standard land patterns.

Another tool you will need if you plan to have your boards professionally made is a Gerber file viewer. Never, ever send Gerber files off for manufacturing unless you have used a viewer to confirm that they are ok. I recommend ViewMate from Pentalogix and GC-Prevue from GraphiCode. The user interfaces of these programs can be obtuse, but they get the job done.

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