Designing PCBs is a tricky business, even if you know what you’re doing. As you develop your skills, you will no doubt want to start experimenting with more complex and powerful designs. More powerful components will need more power, which means you will have to design your board to distribute the right amount of current to the right places.
This is a tricky thing to get right, but a power delivery network analysis tool can make it much easier.
Current Densities and Temperatures
When many people are designing their first PCBs, they make the mistake of trying to eyeball things. For example, many people will set their trace widths to something that looks like it will work but isn’t rooted in any kind of mathematical or scientific principle. If you choose the wrong width for your traces and make them too thin or too wide, the performance of your board will suffer for it.
Setting your traces to the wrong widths can have an effect beyond just making your board work less efficiently – in some cases, it can even lead to your board sustaining physical damage. If you try and push too much current through a thin wire, the heat generated will burn out your board and its components.
Overdesigning a product is a potential pitfall in most industries. However, with regards to copper, this is less of an issue. The only time you’ll have trouble because of copper is if you start adding an excessive number of power planes to your board. As technology becomes smaller and more sophisticated, we have started to see smaller and smaller power planes as well as power planes of varying shapes.
One thing to watch out for when you’re working with smaller power planes is the potential for bottlenecks and excessive current densities.
Most experienced PCB designers understand the importance of designing their vias to minimize electromagnetic interference, but many still overlook the importance of current in relation to vias. If you aren’t careful, your vias will congest and the increased current density will cause the temperature to rise. If the temperature gets too high, it can end up melting your traces and ruining your board.
Power Delivery Network Analyzer
With a good PDNA, you will be able to check your current densities during the design phase, and you won’t have to wait until a prototype fails to identify any issues. It is worth taking the time to find the best PDN analyzer for your needs, and the CST PDN analyzer is a great starting point. A PDN analyzer won’t show you the precise temperatures generated, but if you know what the strength and density of your currents is, you can work out how much heat is going to be generated.
A power delivery network analyzer is one of the most essential PCB design tools for any designer’s toolkit. Don’t wait until the prototyping stage to identify design issues when you can nip them in the bud much earlier on in the process.