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PCBs and IoT: Being Prepared for Circuit Design Challenges

Examples of PCBs and IoT devices include laptops, cameras, bluetooth headphones, smartwatches and smartphones

They are everywhere these days, those small “internet of things” (IoT) devices that help out in so many ways. I just looked out my window and noticed my neighbor opening her garage door remotely while I was asking my “voice-controlled automated personal assistant” to brief me on the day’s events. Yes, indeed, they are everywhere. Who would have ever guessed that we would one day be able to network together our home appliances so as to schedule and coordinate washing and cooking chores. But there’s so much more to the world of IoT then simply asking Alexa to give me the outdoor temperature.

Global IoT growth will include all kinds of different IoT devices for personal wearables, industrial machinery, and healthcare applications. These devices will continue to improve and add to their functionality all the while getting smaller, lighter, and faster. The pressure is already on to leverage existing design technologies as well as to find new design solutions to create these devices, and that puts the PCB designer square in the middle of this growing field. Let’s take a look at some of the design challenges of IoT and how PCB designers will need to design to new levels of technology in order to answer these challenges.

PCBs and IoT: Smaller, Lighter, Faster

New applications for IoT devices are appearing every day. You already know about smart watches and other common devices that are connected to the internet, but there are also other devices that don’t necessarily come so quickly to mind. These would include life-saving devices such as health related products that monitor and report our vital statistics, or devices such as automated drones.

In each case, there is an overwhelming need to continually improve their performance, increase their power and range, and yet reduce their size. Designing these devices will take a lot of skill on the part of the PCB designer as well as some new design technology.

Consider a smart watch whose design requires packing in a lot of circuitry into a very small space. The obvious components will already take up a majority of the room: the display, battery, and the sensors. In addition, the smart watch is also going to require a CPU, memory, graphics processing, and wireless circuitry.

A lot of this can fit on a system on chip (SoC) component that will be designed into the IoT device, but there will still be a lot more that has to be packed in. Wearable IoT devices like smart watches need to be light enough to be worn by their owners without them being a burden, while at the same time increasing their functionality.

Achieving the goal of smaller, lighter, and faster in IoT designs will require PCB designers to work more with advanced design technologies. These will include high density interconnect (HDI) design methodologies, embedded components, and compact components such as multi-chip modules (MCM) and three-dimensional ICs (3D-IC). Another area of design that has become crucial in the design of IoT devices is using flex PCBs.


App icons float above the profile of a smartwatch

High computing speeds and light weight are tricky requirements to balance boards around


Flex Design in IoT PCBs

As the needs of IoT devices force PCB designers to fit more circuitry into smaller spaces, the need for substrate materials other than standard FR-4 has become apparent. Flex design technology is not new, and the advantages of flexible substrates for PCBs are quickly proving themselves as the best solution to some of the inherent design problems in IoT devices.

For instance, instead of having a standard PCB that connects to a sensor through a complex wiring harness, all the PCB components and the sensor can be built onto one flex PCB. This minimizes the number of individual boards needed for the IoT device, eliminates the problems related to using a wiring harness, and allows the circuit to be folded and fitted precisely into the device.

Flex PCBs along with HDI design practices will improve the performance and reliability of PCBs used in IoT devices. Components and trace routing can be tighter in HDI designs, and by using flex materials all the components and circuitry can be located on one PCB design. This combination of technologies will help to improve signal quality while at the same time reducing power consumption and lowering thermal stress making for a more robust design.


A gloved hand holds a flexible printed circuit board

Flexible circuit boards are pivotal for the functionality and durability of wearable electronics


PCB Design for IoT, the World Gets More Interesting All the Time

As advanced design principles such as HDI design processes and flex PCB materials become more commonplace in IoT devices, PCB designers are going to find that they are ultimately designing the entire product instead of many individual boards as they have traditionally done. This will require working hand-in-hand with mechanical designers as signal integrity, thermal management, form, and fit of the design become more important than ever before.

Not only will PCB designers need to respond to the needs of complex high speed electrical designs, but they will also need to take into account the effects of these circuits in the unusual mechanical configurations of a small IoT device. Flex designs are a real benefit in these circumstances, and PCB designers will have to design as much to the mechanical constraints of the device as they do the electrical constraints.

All of this will require the most advanced PCB design tools for simulation and analysis as well as the ability to work with HDI and flex PCB design processes.

The good news is that the tools you need for the advanced design technologies such as flex design for IoT devices is already here. OrCAD PCB Designer has the features you need within it to make you successful in your IoT designs.

If you’re looking to learn more about how Cadence has the solution for you, talk to us and our team of experts.