Mechanical Design and 3D Modeling Assists With PCB Design In Embedded Systems

May 6, 2017 CircuitStudio

 
When I was in college, we electrical engineers (EEs) always looked down our noses at the mechanical engineers (MEs). Our department had an introduction to electrical engineering class for the MEs, which we referred to as “shocks for jocks.” It’s a bit sad that the mechanical nerds were “jocks” to us. The rivalry between electrical and mechanical engineering often continues after university and plays out in the realm of embedded systems. The embedded systems market is growing larger and more complex each year. It’s time for us to get down off our high horses and augment our design process by collaborating with MEs. In addition, we’ll need to learn their 3D modeling techniques for the designs of today and tomorrow.
 

Embedded Systems: A Growing Market

The field of embedded systems has been growing ever since it was first conceived. This growth is now being accelerated by the advent of the Internet of Things (IoT) and a rise in vehicles with advanced driver assistance systems (ADAS).

 

The embedded systems market was worth around $131 billion in 2014 and is expected to grow to $214 billion by 2020. That’s a compound annual growth rate (CAGR) of 6.3%, not bad. The IoT is a great industry to get involved in if you want to take advantage of this rising tide. IoT devices are becoming ubiquitous, and represent a huge market for embedded systems. Just try not to design PCBs for silly IoT devices, like socks.

 

The automotive industry is another contributor to the growth of embedded systems. Advanced driver assistance systems (ADAS) are being incorporated into tons of cars and will be required in the US and EU by 2020. Unfortunately, you’ll need to pander to those dirty mechanical engineers who design the cars if you want your PCBs to get some wheels. Automotive applications require small, flexible PCBs, so you’ll need to brush up on your advanced design techniques before trying to enter this market.

 


You need to know beforehand if your PCB will be embedded into ice cubes.
 

Electrical Design for Mechanical Applications

Unlike mechanical and electrical engineers, the IoT and ADAS have found common ground in embedded systems. For both applications, PCBs need to be designed with mechanical limitations in mind. That means you’ll have to be the bigger person and enhance your design process with some mechanical techniques. Process enhancement looks like two things: collaborating more with lesser engineers, and appropriating their design tools.

 

Currently, your communication with mechanical engineers may consist of angry back and forth in response to engineering change order (ECO) emails. While struggle is part of life, it’s time to bicker a bit less. Let embedded systems be your peace child. Mechanical engineers know a little more about things like dynamics, thermodynamics, and fluid dynamics. Apparently everything mechanical engineers study is dynamic if only their personalities were as well. Luckily they don’t need an exciting persona to give you information on the forces, temperature differentials, and liquid intrusions that your board will experience. You can be sure that your embedded system board will have these problems. The IoT is cramming boards into tiny devices that will be carried, dropped, and exposed to a range of temperatures. A car is an even more adverse environment what with potholes, engine heat, and the elements to worry about. Collaborating more with MEs at the beginning of your design process will mean less ECOs later, and a board that is better suited for its mechanical environments.

 

I know I’ve been telling you to learn all a lot of new things lately, but you’ll have to add 3D modeling to that list. It’s not enough just to know what kind of mechanical factors your board will be exposed to. Even if you design the perfect board for all external factors you still have to ask, “Will it fit in the enclosure?” How many times have you finished a design, only to curse the ME who designed its tiny, oddly shaped, enclosure? With things like IoT forks and cars jam packed with electronics, space is a concern. It’s time to take matters into your own hands and see if your board will actually fit before you make an expensive prototype. New cutting-edge PCB design software can help you by automatically creating a 3D model for you. This allows you to import some ME’s CAD file for the enclosure and check if your PCB fits, right there on your screen.

 

The current 3D renderings are great, but they’re only the first step. Increasingly complex enclosures will require more advanced 3D capabilities. It won’t be enough to just put a flat PCB in a box and see that nothing sticks out. This is why I suggest getting your hands on a beginner level 3D CAD program and practice how to use it. Rigid flex PCBs may need to be folded into their enclosure. Forget origami, it’s time to move into the computer age. If you know how to use a 3D modeling program, you can animate your 3D PCB and actually show manufacturers how to install your boards. 3D modeling knowledge will also help you if you want to try different layouts for surface mounted technologies (SMTs). Want to see how your board will fit with heat sinks in different places? You could model them yourself and see which configuration will work best. These kinds of things will require more than an automatically generated model. If you don’t learn how to interact with 3D models, you’ll have to hire an ME to do it for you. It’s time to bite the bullet and learn a skill you will certainly need in the coming years.

 


Unfortunately, the only model we’ll interact with is the device in her hand.
 

3D Modeling for a 3D Future

3D printing has come a long way since we used a home printer and magazine paper to etch our own homemade designs. There are printers out there that can already 3D print testable prototypes. The next logical step is printing full designs. Now, we’re not there yet, and probably won’t be for several years; however, when that day comes, you can kiss 2D design goodbye. PCB designers will have to master 3D modeling if they want to take full advantage of future 3D design capabilities. If you don’t start now, you may find mechanical engineers moving into future PCB design, just because they have the 3D design skills. Let’s avoid that nightmare and start learning 3D modeling now.

 

Whether you’re prepping for a future full of embedded systems or 3D design, it’s time to start taking mechanical considerations for your PCB seriously. That means collaborating more with MEs to be certain your PCB can withstand all the forces it will be exposed to. I suggest you go ahead and learn a 3D modeling program as well. Then you can make sure your PCB will fit into its ridiculously small enclosure yourself. You’ll also be ready to take advantage of full 3D design when it arrives. It’s time to become friends or at least acquaintances with the mechanical world.

 

To enter the world of mechanics, you need good software to guide you. Altium’s CircuitStudio is perfectly suited for the designer who’s ready to jump into this whole embedded system design thing. With a wide array of cutting-edge features, CircuitStudio will have you designing PCBs to go where no board has gone before.

 

Have more questions about how to talk to mechanical engineers? Ask an expert at Altium for advice.

 
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