The previous post was about making your own circuit boards. While many good reasons exist to do it yourself we have also found having them made commercially is sometimes the better decision. The Motor Controller Shield used in Lesson 13 is an example of such a board. The number of parts and the complexity make a DIY board challenging. Even so, this board is kept simple to reflect what students experienced in the lessons leading up to building a rolling robot.
The advantages of a commercially made board are:
- Allows for increased complexity. DIY boards are usually single-sided. Some electronic components, such as the MAX 7219 LED Controller, don't lend themselves to a single-sided board.
- Better soldering. Commercially made boards have the correct size holes drilled for component leads, minimizing soldering complexity. The holes are also plated through, meaning they take solder bonding more quickly and securely than can a DIY board.
- Fewer component insertion mistakes. Commercially made boards have silk screen layers on the top and bottom for providing images of the parts to be inserted along with their part numbers and orientations.
- Appearance. Commercially made boards look, let's face it, really cool.
Except, perhaps, for the last item, a board made by a professional fabrication company is more reliable and has fewer initial problems than a DIY board.
The problem is cost. Fritzing, for example, offers fabrication of the circuit boards designed with their tool. But in small volumes these prices are still high, particularly for the low volume student or hobbiest.
To the rescue have come aggrigators, companies that collect small orders until they've enough for a commercial-sized order. The finished boards are sorted and returned to you and me. We, in turn, pay a pro-rated share of the production cost. It's a wonderful system, if you aren't in a big hurry. Typically two to three weeks elapse between order placement and receiving finished boards.
The company we've used with great success and satisfaction is OSH Park. The design tool we use is, of course, Fritzing. The problem is, however, the production files produced by Fritzing aren't an automatic fit for placing an order with OSH Park. For this reason I wrote some instructions. You may find them in How-To #2, How to Make PCBs With OSH Park. Give it a try. The boards appear to be of high quality. The company is a delight to work with. The prices are the lowest we've seen anywhere. And the website, while a little odd in its layout, does its job well.