Pick And Place Hack Chat reveals the secrets of assembly


These days we have powerful free tools for doing CAD and circuit design, cheap desktop 3D printers that can knock down custom cases, and handy services that will spin up a stack of your PCBs and will send them to your front door for far less than anyone could have imagined. In short, if you want to create your own professional-looking gadgets, the only limit is your time and your ambition. Well, assuming you only want to build a few, anyway.

Once you start adding a few zeros to the number of units you’re looking to produce, hand assembly of PCBs quickly becomes a no-start. Enter the pick and place machine. This marvel of modern technology can drop all those microscopic components onto your board in a fraction of the time it would take a human, and never needs a bathroom break. This week, Chris Denney stopped by Hack Chat to talk about these amazing machines and all the minutia needed to turn your PCB design into a finished product.

Chris is the Chief Technology Officer (CTO) of Worthington Assembly, a fast-paced electronics manufacturer in South Deerfield, Massachusetts, that has been building and shipping custom printed circuit boards since 1974. He knows a thing or two about PCB production. and seeks to help junior and mid-level engineers create designs that are easier to manufacture, he launched the “Pick, Place, Podcast” when COVID hit and in-person tours of the facility were no longer possible. Now he says he can tell when a painting is from a regular listener by how many of his tips are incorporated into the design.

So what should you do to make sure your board assembly goes as smoothly as possible? Chris says a lot of it is common sense stuff like including clear polarity indicators, having legible screen printing and using fiduciary markers. But some of the advice might come as a surprise, like his advice to stick with the classic green solder mask. While modern council houses may allow you to choose from a rainbow of colors, the fact is that green is what most equipment has historically been designed to work with.

This black PCB may look slick, but can confuse older pick-and-place machines or conveyors that were designed with the reflectivity of the classic green PCB in mind. It also makes automated optical inspection (AOI) much more difficult, especially with small component packages. That said, other colors such as white and red are less of a problem and often just require fine-tuning of the equipment.

It also pulled back the curtain a bit on how the contract manufacturing (CM) world works. While many might feel like PCB gaming has moved overseas, Chris says orders under 10,000 units are still largely handled by domestic CMs to minimize turnaround times. He also notes that many editing houses are almost entirely backed by a few large accounts, so even if they juggle 50 clients, there are usually only two or three “big fish” supplying 80% of their business. With such a tight-knit group, he warns CMs can be a bit selective; thus, if a client is hard to work with, they can easily end up short term.

While the Hack Chat is officially only scheduled for an hour, Chris spent nearly three hours chatting with community members about everything and nothing to do with electronic design and production. His knowledge and passion for the subject was evident, and we are glad he was able to find time in his schedule to join us.

The Hack Chat is a weekly online chat session hosted by leading experts from all corners of the hardware hacking universe. It’s a great way for hackers to connect in a fun and informal way, but if you can’t stream it live, these roundups along with the transcripts posted on Hackaday.io ensure you don’t miss a thing.


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