At the heart of every electronic device is a PCB, or printed circuit board. That’s true whether we’re talking about your tablet computer or a life-saving pacemaker. From fitness trackers to computer motherboards, calculators to smartphones, circuit boards are everywhere today. And the explosion of electronic devices and the new ways we’re using them means one thing: PCB design is more important than ever. In this post, we’ll explore some of the most critical PCB design and layout tips you should know.
Node Location Is Critical
Perhaps the most important tip on our list is this – make important nodes as accessible as possible. This is particularly relevant to troubleshooting why your design is not working. If your important nodes aren’t accessible, your testing is going to hit a wall. Whether you’re going with loop-style nodes or something else, make sure they’re easy to access.
Component Spacing Matters a Lot
Today’s circuit boards support far more components than ever before. That’s great from an end-user standpoint. The more components on a board, the more functionality it supports, and the more users can do with the device. However, what is an advantage for end users can be a challenge for designers.
Simply put, the more components you add to a board, the more cramped they become within the design. And, make no mistake, component spacing matters a lot. Why is that? You’ll find several reasons. One of those is that without the appropriate amount of spacing, you lack room for wire routing. Another challenge is that those components create heat, and the closer they’re packed, the more heat builds up in the board. In some cases, that might be enough to compromise the board material itself, particularly if you’re using something like FR-4 rather than a material designed to handle high levels of heat.
Speaking of Heat…
Heat will always be a problem, but it is not insurmountable. One quick tip to help you get around high-heat-related issues is to add extra copper around surface mount components. This creates additional surface area and helps dissipate more heat, faster, effectively turning a portion of the PCB design into a heatsink.
Shrink Your Components
Struggling with an unrouteable board? Use smaller components. By going with a smaller footprint, you leave more room for copper traces to pass each component. Proper spacing is easier to maintain with smaller components, too, helping you avoid overcrowding the board and the other problems that go hand in hand with stacking components too close to one another.
What should you do? While quad flat package components might be your first option, you might want to consider going with ball grid array components, instead. Of course, there is a trade-off here – smaller components make repair work more challenging.
Play Tetris
Does the following situation sound familiar? You’re staring at your PCB design, struggling to fit each component in and route traces between them. No matter where you put them, you’re left with problems, particularly if the board is smaller.
The answer? Play a game of Tetris with your components. Rotate them and find the best arrangement that allows you to route traces directly between them while maximizing the use of space across the entire board. This can take some time and effort, but it’s well worth the minimal investment you’ll make.
Pay Attention to Arrangement
Sometimes, rotating your components is simply not enough. When that happens, it’s important to come at the situation with a bit of strategy in terms of component arrangement. How, though?
- Cascaded Components: Cascaded components play a vital role in many PCB design options. However, they can be challenging to arrange correctly. Keep them near one another, and make sure that they are in sequence on the board. That will immediately remove the challenge of trying to route traces all across the board to connect cascaded components located in different areas.
- Consolidate: Why use multiple smaller resistors when a single higher resistance one will work better? Consolidating your design ensures that there’s more room for components and traces, as resistors will take up less of your available space.
- Cascade from the Edge: When laying out your PCB design, identify any component that must be attached via an edge connector. Locate those components as close to the connector as you can. The rest of the chain should cascade away from that point, grouped into functional blocks near one another and in sequence.
Go Denserdesign software
If you are struggling with PCB design, chances are good that the space required for traces, vias, and clearance is a problem. You can get around that by going denser. With HDI, you can create very dense boards with very dense traces, clearances, and vias that still deliver performance. However, you do need to consider controlled impedance routing, differential pairs, and check creepage, clearance, and width when it comes to high-current and high-voltage design.
Watch the Noise
Signal noise can be problematic when it comes to some traces. However, placing high-frequency signal carrying traces too close together can couple those signals, ratcheting up the noise and possibly creating problems with traces where no noise is desired. Make sure that you keep noisy traces away from analog traces to avoid this problem.
A Helping Hand
As you can see, there are many considerations to make when it comes to PCB design. If you’re struggling to get it right, we can help. At Advanced Circuits, we have decades of experience working with clients ranging from individuals to Fortune 500 companies and helping them bring their PCB designs to life. From our groundbreaking design software to our production capabilities, we have a solution no matter what your needs might be. Contact us today to schedule your consultation or to learn more about our capabilities and services.
