The Secrets (and Challenges) of PCB Design in a Chip Shortage

Sourcing PCB components is a significant barrier to PCB design progress and has resulted in a shift in thinking.

Ever planned out a picture-perfect day—favorite breakfast spot, stroll along the river, afternoon wine-tasting—only to have it ruined by chance? The café’s out of bacon. It’s started raining. The winery’s closed: Private Event.

That’s how printed circuit board (PCB) design has felt lately. PCB design is a major component (pun intended) of product development here at Treetown Tech. But in the face of a global pandemic and major chip shortage, our engineers have had to adapt their approach to PCB design projects. Want to know how?

Wait, how’d we end up in a chip shortage?

PCB design involves selecting electrical components (microprocessors, FETs, resistors, and so on), creating a design, and developing a prototype. Normally, this gets sent to a PCB manufacturer, who procures parts through the supply chain and builds a completed assembly. In a few days or weeks, you will receive your prototypes.

Enter Covid-19—shutdowns, workforce, resource shortages, and extended production timelines. In the best of times, changing over fabrication lines is a lengthy process. In the worst of times (i.e., 2020), companies made predictions about where demand would shift; unfortunately, some guessed wrong. Then, big companies saw their typical chip suppliers losing access, much like individual households and toilet paper. They pooled their buying power and scooped up what they could, exacerbating the shortage even more.

We’re now a few years on, but global shortages continue, and chips remain difficult to procure. So our designers have simply (or not so simply) adapted.

How did we adjust our design process?

PCB design includes two types of components, broadly speaking. The first type (e.g., resistors or capacitors) are more of a commodity and fairly interchangeable. The more complex types, such as microcontrollers, are incredibly specific and not easily replaced with an equivalent part.

When unique core pieces your system is built around become unavailable, you have two choices: wait a long time (perhaps indefinitely) for them to return in stock or change the design. But you can’t just change the design. You also need to be able to get your new core piece(s), and that means ordering ahead.

We’ve come to expect shortages, and our engineers have pivoted their whole approach. We need to account for procurement time in the design process and start by looking at stock for various parts. Stock can disappear fast, so buying the highest-risk items is critical. 50,000 in-stock chips can vanish in a single day and be replaced with a 99+ week lead time. (Not-so-fun fact: the plus means no one ever accounted for three-digit lead times….we take it to mean they really don’t know when they’ll have the part)

While we spend more time buying parts than we used to and often buy them before going into detailed design, the basic principles behind our design process haven’t changed. Our engineers still think outside the box, plan, and problem-solve creatively. Whereas before, a designer would send a completed schematic to a PCB manufacturer for them to procure the parts and build the full assembly, now we purchase the components that we believe will get the job done upfront, design a board around them, and then ship both the design and the parts to our manufacturing partners for PCB assembly. While this process seems backward, it actually saves us, and ultimately our customers, time and money by avoiding late-stage design changes due to parts being out of stock. 

Flexible creativity, creative flexibility

The past few years have forced all sorts of positive and negative changes, but one thing that hasn’t changed at Treetown Tech is our creativity. Our team loves to think above and beyond just a “perfect spec.” Flexible design means our creativity and problem-solving work tirelessly to serve your vision. After all, a truly perfect spec makes everyone happy: from sales and marketing to operations and, most importantly, your customers.