Electronics of today are nothing like they were in your mother’s day, and even nothing like they were even a year or two ago. Why do you think Apple, Samsung, LG and Motorola keep updating their bestselling cell phone models year by year? As technology advances, so too do the devices which utilize technology and if there is one consistency in changes across the board, it would be the reduction of size.
Smaller PCBs Present New Issues
Electronics just keep getting smaller and smaller, which is great on the user end, but for the designer and manufacturer, PCB design rules just keep getting more and more complicated. As those printed circuit boards keep getting smaller, designers need to take a serious look at just how heat will affect them. Will it create issues in operability and stability? Sometimes that can definitely be the case so it is imperative to look at just how heat could present an issue and how to avoid a PCB overheating.
How Heat Affects a PCB
Most current technology has failsafes built in so that when a gadget overheats, it automatically shuts down. We all know that because of our frustrations when suddenly our laptop decides to go night-night if the cooling fan fails. The same can be said of any device. If it overheats it will either say “See you later,” or “Bye-Bye.” Neither option is okay but it would be far better to shut down for cooling than to short out altogether, rendering that device or gadget inoperable – sometimes forever. It all depends on how much heat damage the PCB and components sustain. So heating issues have a huge impact on PCB design.
PCB Design Rules to Avoid Heat Issues
While there are a number of rules in keeping with today’s smaller devices requiring smaller circuitry, you should understand issues that affect heating on your PCB. Some common PCB design rules can be found here, so pay careful attention to those which identify potential issues with heat. Basics would include:
- Distance between traces.
- Thickness of copper on those traces.
- Resistance on traces – greater resistance leads to heating issues.
- Distance of traces from edges of the board.
Some of those make sense at first glance. For instance, we all know that greater resistance builds electrostatic energy which creates heat. However, how could the distance of a trace from the edge of a board create heat issues?
Avoiding Heat Issues from the Very Beginning of PCB Design
As a designer, you know that prevention is worth its weight in gold when it comes to avoiding problems that could render your gadget or device inoperable. At one end of the spectrum you have a device that may be significantly slowed by excessive heat and at the other end, a device that shorts out, frying the entire circuitry. Stages in between include periods of shutting down to cool and a small short which can be easily repaired by a qualified technician with a soldering iron. None of those are good options.
In the end, it is important to understand how heat affects that PCB you are designing and then how to avoid any of those issues. PCB design rules may have changed, but so can you. Keep up with the times for best practices in PCB design.