First PCBs

June 27, 2008 | 1 Minute Read

Just received the first printed circuit boards for my Ifos project.

I used OurPCB, which was inexpensive and fast. Board quality is great—but then I have zero experience evaluating PCB manufacturers. Total cost was $98 for 10 boards (4.15” × 2.9” × 2 layer, 2-sided mask, 1-sided silk), including a one-time $50 tooling fee and $30 shipping. Electrical testing was free, with lead time right around 10 days.

Choosing an off-shore manufacturer (OurPCB is in China) was a difficult decision. There are many domestic companies I could have used, but all were 5 to 25(!) times more expensive. BatchPCB is a little more competitive, at just above 3 times the cost, but only because they outsource their manufacturing overseas themselves. They are associated with SparkFun, however, which is almost reason enough to use them.

In the end, though, I don’t really know what that extra money buys. Better working conditions? Higher pay? More stringent environmental controls? Improved quality?

PCB in case

Back side of PCB

Unfortunately, in the rush of last-minute changes before sending the gerbers off to manufacturing, I moved a component and caused it to overlap a trace for a different signal. A design rules check (DRC) caught the problem, but not until I remembered to run it—the next day. Oops.

Within hours of receiving the boards, though, I discovered an even bigger issue: the land pattern I created for the MAX6957 LED driver was based on the 36-pin SSOP, which uses 0.8mm pitch. I designed the board with the 28-pin version in mind, but since I had a couple samples of the larger chip, I used them as a model. Unfortunately, the smaller version uses 0.65mm pitch. Oops.

The moral of the story: don’t assume you know it all, don’t forget that last DRC, and always check the datasheet! Version two should arrive around July 18. This time I chose blue solder mask, just for the fun of it.