Printed circuit boards (PCBs) are the cornerstone of any electronic device and represent the glue that ties together components or submodules together. We can help you navigate the PCB design process and bring your next electronic project to life, guiding you from product conception through to actual manufacturing. Developing circuits can be very complex with many pitfalls that could render a whole design useless and become expensive and time wasting, this is why it is critical to have a experienced engineering on your side who has lived through these learning experiences. Since most designs also incorporate some kind of embedded microcontroller, it can also be very valuable to have embedded software development experience on your side who can make sure that your circuit is designed in a way that eases firmware development. Consider this when deciding on who you want to partner with to make your next PCB design.
Process
The following describes the basic process that we follow to bring your conceptual electronic idea to life.
In the System architecture design phase, we start from any top-level requirements you have and break them down into lower-level requirements, then we design an architecture that will meet them. For example, some clients will have a general idea of what they want the device to do, but not much else, whereas other may have specific chips they want to use. Of course, we can offer guidance on what parameters need to be decided like dimensions, mechanical fit, power supply, I/O interfaces, etc.. Once we agree with you on the high-level and low-level requirements, we can design an architecture. The architecture defines the main components (such as Integrated Circuits, transistors, connectors, etc..) that will make up the design and how they connect together. After choosing the main components, the architecture is verified against the requirements set.
The next step, Non-Form-Factor (NonFF) prototype phase involves verifying our assumptions made in the system architecture design. For some very simple and straightforward designs this phase might be skipped. Here, we may use breadboards and/or development kits provided by device manufacturers to wire together subsystems of the architecture. We can write some simple code if necessary and take measurements from the circuits to determine whether they will work in PCB design. The goal of this phase is to de-risk the following phases of development where major costs will start to be incurred in the design and manufacture of PCBs. We want to catch any show-stopping problems here while we can be more agile to change things.
Once we are confident in the architecture design, we can start with schematic capture which is creating a graphical description of how all the components wire together electrically. In contrast to the architecture design where only major components needed to be identified, in the schematic phase, we are determining the type and value for every component needed, down to each resistor and capacitor. Often we need to dive into the datasheets of each component to determine how they need to interface with each other (e.g. voltage levels, bus types and speeds). We also need to make some decisions, for instance, which pins of a microcontroller to use, that will have an impact on the firmware development, so having embedded software experience is very useful here. For analog circuits, we will need to do the circuit analysis and math to determine which values to choose for components (e.g. determining the frequency cut-off for an analog filter). In some cases, we may catch some design issues that require architectural changes, but it is still not too expensive to change minor things at this point.
The PCB layout phase we often start concurrently with the schematic capture, but finishes after the schematic is finalized. There are a few sub tasks of the PCB layout: We must create or find footprints for each device to be used on the PCB. The footprint defines how the device pins interface, and solder down to the PCB. For many parts (like resistors and capacitors), standard footprints already exist and we just need to choose the right one. For other parts, we need to read the datasheet and accurately transcribe the documented footprint into our tools. Once footprints are created, we can do floorplanning, which is placing all the components spatially within the outline of the board. Experience plays a big role here since components need to placed in a way that eases routing and takes into account thermal issues, ease of manufacturing, and ease of debugging. Finally, we can route the board, which is drawing the physical copper traces that should connect the pads together according to the schematic. Again, experience has an outsize role here to take into account electromagnetic emission and susceptibility of the signals, heat dissipation, etc…
Once the PCB has been routed we can prepare files for manufacturing. In this phase, we check and double-check the PCB design for any errors through both manual and automatic means. It can be helpful to have a third-party engineer review the design at this point as well. To manufacture the PCB requires generating industry-standard “Gerber” files, which describe the different PCB layers, as well as some other files, like the drilling file, pick-and-place file, bill-of-materials (BOM) and netlist.
Our first manufacturing phase for a new design is usually a low-volume manufacturing phase. We want to check that the entire design works according to specification before incurring the major expenses of a larger volume. This will also be the first time you have a form-factor (FF) device in-hand to validate that this is actually the device you want to build. For simple designs, we may just have the PCB created without assembly (PCBA) which can save significantly on cost for low quantity orders. However, most of the time we are ordering PCB with PCBA. We work with a few different manufacturers depending on the type of board, the client’s budget and timeline. Typically overseas manufacturing can be much cheaper than USA-based manufacturing, but overseas can have a much more uncertain timeline due to customs and communications delays.
The path forward after low-volume manufacturing varies greatly depending on the product. For instance, if we are developing a sub-module of a larger system, you might just archive the design until you manufacture the larger system. For sub-modules, compliance testing is typically not required because the entire system must be compliance tested. If you are planning to manufacture the device as a standalone unit, then you will need to go through compliance testing with bodies like the FCC and UL. There are third-party laboratories that can coordinate this for you and costs will vary depending on what your device does (for instance if your device has a radio, the FCC testing is more comprehensive). If all goes well, you can start to order larger quantities (100-1000) to do alpha and beta testing, and eventually sales.
Although this process has many steps and is a lot to take in, an experienced engineer can handle most of the details of realizing your ideas. If you have any electronic projects you would like to discuss with us, please contact us.