Issue link: https://iconnect007.uberflip.com/i/929192
26 DESIGN007 MAGAZINE I JANUARY 2018 to the final production revision (and I'm being optimistic here; some will take more, others less), then we are facing a million designs. Who will design those boards? There are lots of PCB designs to be done, and yet in North America, we see an aging of the PCB designer community and slowly declining numbers of those in the dedicated job. At this point, there appears to be not enough new dedicated designers entering the job market to meet the need. At the same time, we can observe more and more electronics and electrical engineers bridging the roles of circuit and PCB design, rather than having dedicated engineering and PCB design roles working separately. Evidence of this has been everywhere for more than a decade. Today, you could look at nearly any crowd-funding campaign for an electronic device, and the same inventor or engineer who came up with the idea did the electrical engi- neering, PCB layout and firmware develop- ment. We're increasingly wearing all the hats; it's not intentional, but the natural outcome for startups to save money and time, enabled by tools. What do IoT PCB designs look like? What kind of boards go into IoT devices any- way? I look at the current generation of con- nected devices for example, and it's a mixed bag. The smart thermostat in my home has two PCBs inside: one is a double-sided relay, power and connector block for wiring into the air conditioning system, and the other is the board with all the "smarts" on it. With- out destructively taking a microsection, I can tell that board is at least four layers of copper, probably six, since it has a decent sized SoC chip and some DDR memory on it. I've also done destructive analysis of smart health monitoring wearables from well-known manufacturers. In those designs, I typically see a single board that's rigid-flex, likely with a minimum of six layers in the rigid parts, with mixed signal sections on the flex for RF con- nectivity (Bluetooth, Wi-Fi). In one case, there were two separate PCBs with a flex circuit con- nector (FPC) linking them. Surveys show that the most frequently designed boards still have between two and six layers, but there has been a marked increase (>10%) over the past five years of boards in the seven-to-10 layers category. This is reflec- tive of the kinds of components needed for IoT and smart, connected products. User interfaces with capacitive touch and high-resolution dis- plays require multimedia processing, upping the pin counts and memory amounts and speeds used. Naturally having to add power- ful SoC chips and DDR3/4 memory along with high-speed wireless makes the boards more complex as time marches on. There are a lot of sensor and power and connectivity boards, and a lot of main boards with complex compute power, to design. For reliable production, cost savings, reuse and supply chain flexibility, a lot of these products will naturally need to be divided into multi- board systems. And the amount of time avail- able to a comparatively diminished workforce for designing these boards right keeps getting shorter. IoT Design Bottlenecks It's hard to design boards right the first time in every respect. Thanks to great teachers in our industry, along with IPC designer certifica- tion and training, we are constantly improving Figure 1: Fitness tracker (Source: Altium LLC, PCB2020 Roadmap Presentation 2017).