Understanding best practices when it comes to PCB layout and design is critical. Whether you’re helping students understand how modern consumer electronics work, or you’re designing consumer electronics yourself, PCBs lie at the heart of the matter. From clocks to computers, ovens to pool timers, there’s a printed circuit board (PCB) in almost every single device today. However, to ensure functionality, safe operation, and to protect against shorts and other damage, specific layout steps should be taken. Below, we’ll explore some of what you’ll need to know when it comes to PCB layout and design.
To ensure that you have a good PCB layout, it’s important to understand a bit more about the structure of PCBs.
- Base – The base material is most often made from fiberglass or glass epoxy fibers. FR4 is the most commonly used such material, but there are other options available depending on your project and other factors. One example is high-temp resistant plastic. A solid base is used to help ensure that the PCB is rigid and can hold components. With that being said, board thickness can vary dramatically from one application to another, ranging from 0.8mm to as thick as 1.6mm or even more in some cases.
- Components – A very broad range of components will need to be integrated with the PCB, including resistors, and numerous others. The number of components and their relative size will determine the size of the board, as well, although some techniques can be used to reduce the size, such as miniaturization, as well as creating double-sided PCBs and multilayer PCBs. These latter two options help you condense what would be very large PCBs into a footprint that is a fraction of the size.
- Copper – Copper is used with most PCBs, and is the metal through which electrons flow, powering the components and, ultimately, the device in which the PCB is installed. Copper may be layered directly onto the board in varying thicknesses, or copper foil may be applied instead, depending on the needs of the project. Copper is usually measured in ounces per square foot, with the most common being one ounce per square foot. However, high-capacity PCBs can hold much more copper, up to three ounces per square foot.
The first thing you need to do in the PCB design process is what’s called discovery. This begins with the need that the PCB will address. What do you need to accomplish? What will the circuit do? Why is it necessary? This will determine a wide range of factors concerning your circuit, including size, functionality, components, and more. However, understand that there is no “right” or “wrong” way to do something. The design is always up to you and should be what:
- Works best
- Delivers the desired functionality
- Uses the least amount of energy
- Creates the least amount of heat
Create a Schematic
Before you begin actually designing your PCB, it’s wise to create a basic schematic. This allows you to rough out your ideas, play around with layout, think about components, address things like resistance, and more. You can make this schematic in many ways, but the simplest is to use a robust PCB design software. We offer PCB Artist, which is fully functional, powerful, and free to use.
The Design and Layout Process
Once you have started the discovery process and defined the need and goal of the circuit, you can move into the PCB layout and design portion of the process. There several things to consider here, including the following:
- Components: Where will your components be located in the circuit? What orientation is best? Ideally, you’ll maintain the same orientation for all components to help reduce soldering and routing errors. It also makes your board easier to install and test. So, no matter what your components might be, make sure they’re facing the same direction with the #1 pin at the top left.
- Relational Placement: In addition to directional placement, you also need to think about relational placement. That is, how close are you placing your components to one another? In PCB layout, you want to leave space between components for your traces and to help reduce heat.
- Placement Restrictions: Finally, PCB layout will require that you think about placement in relation to component size. Taller components must be placed on areas of the board where they’re less likely to encounter part of the device. Shorter components should be interspersed between taller ones. Taller components cannot block shorter ones, either, as this will often result in poorly soldered joints. Height and width should be checked prior to finalizing your layout.
Note that in some cases, you will need to do more than just place your components using your design software. Make sure that you can rotate and reposition your components to maximize your use of space and ensure accurate placement. You should also remember that if you rotate one component and change the orientation, you’ll need to do the same for other components to keep them oriented in the same direction.
- Routing: Routing refers to the actual placement of the traces that connect your components to each other and allow electricity to flow through the circuit. If your components are too close together, you’ll have little room for these connections. You should plan your PCB layout from the beginning with routing in mind to make the process easier.
PCB Layout Made Simple
PCB layout and design can be incredibly complex. However, the right tools can help. Our PCB Artist software offers intuitive controls and powerful tools to help you design your boards. You will also find a massive part library, and valuable tips, as well as tutorials to help you get the most out of your software. When you’re done, Advanced Circuits is here to help you bring your board to life through expert manufacturing processes. Ready to bring your project to completion? Get in touch with us today.