Heavy Copper PCB Design Tips

Nowadays, heavy copper PCB (copper thickness >4 oz) has become popular in PCB industry because it is suitable for high-voltage and high-power application, as most PCBs are manufactured just for low-voltage or low-power application with traces generally contain from 0.5 oz to 3 oz copper weight. 

But some PCB designers always get the boards fail the current test, why? Because they sometimes forget a fact that every PCB facility has its process limits and capabilities, even on the same design, so once you choose a manufacturer to take your heavy copper PCBs, you’d better consult them three questions before designing. 

1. Their Min Trace Width

   Trace width is a requirement that all designers pay great attention to ensure that the trace can handle the required current capacity on the project. How much current can a copper circuit safely carry and how much heat rise can your project withstand? They are always determined by the traces on the circuits. Thus, it is important for you to know their min trace width and space which they can make for heavy copper PCB.

2. Material for Heavy Copper PCBs

   For PCB in low-voltage or low-power application, use standard FR-4 or high-temperature FR-4 is enough. But as to those projects with heavy copper PCBs which will be used in high-voltage and high-power application, it is ideal to use high Tg material to make sure your final PCBs can endure higher processing temperature.

3. Their Etching Process on Heavy Copper PCBs

   Standard PCBs, double-sides or multi-layers, are manufactured with a combination of copper etching and plating processes. If the way they etch on heavy copper PCBs is the same with etching on standard board, you’ better ask them the base copper on the material and how to etch and plate the extra copper on the circuits. 

All in all, when designing heavy copper PCBs, more contact with your PCB manufacturer for all technical and manufacturing issues can really help you a lot.