Tag Archives: printed circuit board

Books and Resources, Electronics

Cheap Prototype PCBs from DorkbotPDX

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Three 2-layer boards, $5/sq inch. No setup fee!

Laen of DorkbotPDX has been running a PCB proto service for some time now, and I finally got a chance to try it out this month.

The pricing is simple.  For 2-layer boards, it’s $5 per square inch for three (3) PCBs, with no setup charge, and shipping is free.

The tunaround time is typically 9 days + first class mail shipping, which ends up being just under two weeks total fom PCB release to delivery in Austin.  This is pretty good for a group order, and signficantly faster than BatchPCB (based on my experience).

The only downsides that I am aware of are:

  • PCB orders only go out once a month, unless there is enough demand to justify a 2nd run.
  • If you wait too long, the panels can fill up.  Again, if there is enough demand, sometimes a 2nd panel can be added, but don’t count on it.
  • The soldermask and silkscreen can be any color (and you don’t get to choose!)  BatchPCB at least guarantees the standard white/green.

4-layer boards are available as well, but at a higher cost ($10/square inch) and less frequent intervals.

Entries for the next PCB order are due on October 25th.  The more orders Laen gets, the more likely he is to continue the service, so if you have some designs you’ve been thinking about but have been put off by expensive PCB costs, finish them up and get some boards made!

Books and Resources

Coombs: Printed Circuits Handbook

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Printed Circuits Handbook

If The Art of Electronics is the bible of electronic circuit design, then the Printed Circuits Handbook is almost certainly the bible of printed circuit board (PCB) technology.

I say this because even if you disregard the volumes of useful information inside (much of which I have never seen elsewhere online or in print), this book deserves to win ‘bible’ status thanks to its 1000 pages and phonebook-quality heft!

All joking aside, this book is a great resource for anyone is serious about making good PCBs.  I have worked with PCBs as a design engineer for several years now, and I learned something about printed circuit boards within minutes of opening the cover.  Hours later, I was still flipping pages.

How could I walk away from a book that contains in depth discussions of topics like the difference between water soluble and no-clean flux and how to clean the leftover residue from each?  Ever wondered what the myriad of surface finish options your PCB vendor offers you really mean?  This book will explain the difference between HASL and ENIG, and why you shouldn’t blindly check the box that says “lead-free” without considering the consequences on your assembly process.

This is the kind of stuff they don’t teach you in school, and as a design engineer I have received only glimpses of in the industry.

Some of the highlights of this book for me are:

  • The most thorough discussion of PCB manufacturing that I have ever seen (almost 300 pages!).  Want to know how the PCB you just got was made?  One layer or sixteen layers, it’s all in here.
  • Lots of information about custom laminates, high density interconnect techniques, microvias, blind/buried vias, plating and surface finishes, solder masks, conformal coating, etc.
  • Several charts of current handling ability of PCB traces, planes, and vias.
  • A chapter on thermal design of PCBs.
  • Lots of information about soldering techniques.  Ever wondered how soldering works and what flux really does?  It’s in here too.
  • Seven (!) chapters on design, manufacturing, and test of flex circuits.

Be forewarned that the technical level of this book is fairly high.  It is clearly targeted towards people working in the PCB industry, but most engineers and even serious hobbyists would probably get something out of it.  That said, this is definitely not a book for beginners!

(And to the other design engineers out there: Want to one-up the manufacturing and reliability guys in the break room?  Read this book!  :-))

Printed Circuits Handbook (McGraw Hill Handbooks)

Electronics

Flickr Printed Circuit Boards Photo Pool Hits 100 Members!

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100 wonderful, amazing people have joined the Flickr Printed Circuit Boards Group since I launched it in July of last year!

The pool features over 400 pictures of printed circuit boards, many of them CC licensed.  There’s a little bit of everything, from homebrew board fab to PCB jewelry and even miniatature cityscapes.

If you have some cool PCB images of your own, add them to the pool!

One of my favorites: Car Park or Printed Circuit Board?

Flickr PCB Photo Pool

Books and Resources, Electronics

Poll: Who is your favorite prototype PCB vendor?

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As I wait for my AVR High Voltage Programmer Shield PCBs to come back from BatchPCB, I’m starting to wonder what prototype PCB services other people are using for their boards.

Ladyada has a PCB Cost Comparison Calculator that shows the significant differences in price between various low volume PCB vendors, but what’s missing from the chart is the answer to: What vendors are people actually using?

If the cheapest fab house is also the best, obviously the more expensive vendors wouldn’t be around, would they?  Unfortunately, it’s usually not that simple, cheap usually means slow, or low quality, or both.

I know that some visitors to this site make prototype PCBs at home and others send them out to be fabricated.  How do you get your prototype boards made?  Vote below.

[poll id=”2″]