While printed circuit boards have become ever more complex and feature far smaller components that were used even a few years ago, the general process of designing the printed circuit board remains the same. This process hasn’t changed as we’ve shifted from hardwired functionality to software-defined systems. Here is an engineer’s guide to PCB design that everyone can understand.
Outline the Basic Requirements
The first step to designing a printed circuit board is outlining the requirements. What are you building? What is it supposed to do? Software-defined radios will need very different components than a refrigerator control board. What type of space does it need to fit into? What will connect to it? How will it get power, data inputs and anything else it needs?
Sketch Out the Concept
This is where you create a variety of high-level conceptual designs. Are you going to create a single layered PCB and connect to third-party components? Or will you put all the components on one PCB? Or should you use a motherboard with several plugged-in data cards? Where do you need to put connectors for power, data, and other hardware? If a peripheral will perform a specific task, then you don’t have to build that functionality into your PCB, but you’ll need to plan on how to connect the PCB with the peripheral. Will you be building a broad design that controls its specific function with software or will you build a robust PCB with a very specific function? For example, are you building a simple radio that can take a beating or a software defined radio that can receive almost any frequency?
Design It is a Unified System
Create the fully fleshed out PCB in a unified software suite that allows you to do everything within one set of tools. Then you will be able to work on designs, reference materials and supplier data, test designs and anything else you could remotely need to do in one place. Once you have a concept design, you’ll want to lay out the schematic with all of the components and routing.
Engineers need all of their documents in one place so they don’t waste time searching for documents, much less run the risk of accessing an old version of a critical file and waste time designing old specs and requirements. Software like Altium design viewer, keeps all specification documents, PCB design files, and schematics in one place. Engineers can also scroll through supplier data to verify parts are available for immediate use in production before saying that’s the component that should be used on this PCB.
After design verification comes to the creation of process documentation. This is made much simpler when you use a PCB design tool like Altium that automatically maintains bills of material and other documentation for you. Gerber files are generated to tell the PCB manufacturer how to make the PCB. Schematic documents explain where to put the components and connect them. Once this is done, you can send the process documentation to the manufacturer to actually make the board you’ve designed.