A printed circuit board (PCB) is a component that’s part of almost all electronic devices we use in daily life. PCBs form the foundation of circuits and hold together all the electrical and electronic components.
If you’re looking to build your own electronics circuit, you need to be familiar with the basics of PCB design. The entire process may seem intimidating to beginners, but you don’t have to be an engineer to approach a PCB design project.
Most PCB projects follow certain steps, making it easy to get started with little-to-no experience. Find out more about how to plan your PCB design project.
What is a PCB?
If you’ve ever dissected electronics, you’ve likely seen a sheet that’s green, blue, or red with silver threads and components. This is a PCB. Though a PCB may look like complicated and foreign technology, once you’re familiar with the design, it becomes much easier to imagine your own boards and applications.
PCBs are the foundation of complex circuits and made modern technology like smartphones, laptops, and flatscreen televisions possible. Depending on the electronic device, PCBs can be manufactured with one, two, or multiple layers to address the needs of the circuit.
If you’re entering into the PCB design process, it’s important to know some basic PCB terminology.
- Soldermask: This is the green, red, or blue, non-conductive layer of the PCB that shields it from a short circuit.
- Silkscreen: These are the white markings on a PCB that depict component symbols, logos, letters, or other information for the circuit connection.
- Layers: A PCB is composed of layers bound together. The outermost layer is where the components are mounted, while the inner layers are used to connect the components.
- Pads: These are copper surfaces that are used to create an electrical connection between components.
- Footprint: All the information about the circuit and pads are saved in the PCB design software as footprints.
- Via or thru-hole: Current flows through a PCB’s outer layers. Blind via is a path that connects the outer layer and the immediate layer, rather than just the outer layers.
- Annular rings: These are copper rings that encircle plated holes.
- Design rule check: This is a software-based check that identifies glitches in the circuit design.
- Gerber file: This is a file generated during the software design of the circuit that contains information about the copper traces, components, and more.
Now that you know what a PCB is and some basic terminology, learn how you can get started with your own PCB design project.
Start with the Project Requirements
Before you can design your PCB, you need to establish the requirements for the project. You should develop an in-depth understanding of the problem you’re trying to solve and compile a list of essential components and materials.
Depending on the application and industry, your PCB may also need to meet established standards or requirements. If this is the case, create a separate list of requirements that you must have and a list of requirements that would be ideal. With this information, you can design the optimal circuit board while working within your project’s limitations.
Choose Your Budget
Your budget is a big part of your PCB design. Before you come up with a schematic, you need to decide how much your budget allows for PCB costs. It’s better to cut costs early in the process instead of embarking on the project and finding out you have to change the entire design midway through.
Generally, budgets are a range of costs for different components, services, or processes, rather than a set number. Most people overshoot their budget on the first project, so don’t be discouraged if you need to tweak some aspects of your design or plan to meet your budgetary demands.
Create a Schematic
A schematic is an essential component of PCB design. The schematic can start off as a rough draft, but should have all the components and connections necessary to complete the project. You can create a schematic on paper or using dedicated schematic software.
With the schematic, focus on getting a rough draft down with all the basics. It doesn’t have to be perfect on the first try. Create a minimal design that meets your pre-set requirements. When the schematic is started, you can see which components need to be grouped together, which may impact your final PCB design.
Optimize Your Design
The schematic is meant to be tweaked as you go. Optimizing your design means moving components around, changing layers, or making other changes to create a more efficient and functional PCB. The best way to optimize your layout may change with each project, but you want to focus on shortening leads and developing solutions to space limitations on your PCB.
Keep some things in mind while optimizing your layout. Is the board rigid or flexible? Is weight distribution an important factor? How much heat will your board generate? If any of these are a concern, make changes to address the problem. You should be able to create a more accurate list of parts and components and determine if you’re still within the budget. Keep working with your design until you get the performance and cost you prefer.
Speak with a Manufacturer
If you want to buy a PCB, but you’re not sure if you have the best layout, ask the manufacturer for advice and recommendations. PCB manufacturers know their craft and have in-house engineers that will be happy to answer questions and address concerns.
When you ask questions and submit your design for review, they may have valuable advice and insights for you that will save you time, money, and frustration in the future. Fortunately, PCB manufacturers have specialized software that ensures your PCB design will function properly.
In addition, PCB manufacturers have the ability to produce small orders, down to even a single board, so you don’t have to place massive bulk orders to have a professionally manufactured board. This opens up a world of opportunity for students, hobbyists, and craftsman to access the same quality services as professionals.
Schematic Capture: the First Step in the PCB Design Process. The schematic is the logical representation of the electronic circuitry of the circuit board to be built and uses industry-standard symbols and notations to represent different components and their values.
It is due to the solder mask, which protects the copper circuits printed on the fibre glass core to prevent short circuits, soldering errors, etc. The colour of the solder mask gives the board its appearance.
The PCB layout stage includes setting up the design tool, board outline, import of netlist, component placement, routing, silkscreen cleanup, DRC check, and generation of documents for production (Gerbers, netlist, etc.).