Is solder mask a valid electrical insulator?

There is a copper pour over the entire top of the my PCB, which is part of GND net. It turns out that the surface mounted 1W LEDs I'm going to use have the heat slug connected internally to the LED's +ve terminal. Can I rely on the solder mask to insulate the +ve voltage (~3V ish) from GND? Long term?

No, I would not rely on a solder mask as an insulator, because it is very thin and can be nicked easily.

The key issue is going to be how to properly heat sink the LED without a good thermal connection to the heat slug. High-power LEDs usually want the heat slug soldered or thermally epoxied to a heatsink. This can be PCB copper, but since you stated that the PCB copper is connected to the GND net you can’t connect to it.

Read More: LED PCB Assembly

#PCB Assembly #PCB Design

Picture of Oliver Smith

Oliver Smith

Oliver is an experienced electronics engineer skilled in PCB design, analog circuits, embedded systems, and prototyping. His deep knowledge spans schematic capture, firmware coding, simulation, layout, testing, and troubleshooting. Oliver excels at taking projects from concept to mass production using his electrical design talents and mechanical aptitude.
Picture of Oliver Smith

Oliver Smith

Oliver is an experienced electronics engineer skilled in PCB design, analog circuits, embedded systems, and prototyping. His deep knowledge spans schematic capture, firmware coding, simulation, layout, testing, and troubleshooting. Oliver excels at taking projects from concept to mass production using his electrical design talents and mechanical aptitude.

What Others Are Asking

When should I choose 2 layer PCB or 4 layer PCB?

Our brand was focused on common electronic product with single PCB. And this year, we plan to develop a smart range which may require multiple layer PCB. Want to know more about 2 layer PCB or 4 layer PCB.

What kinds of test is suitable for low volume PCB order?

I’ve ordered fabrication and assembly of small PCB batches (100pcs) a couple of times already. Each time the factory asked me if I want to do test on the PCB. But I don’t what to do about it. And I test them by myself. Then, the result of the testing is unacceptable with 15% soldering problems. So bad. I think I will ask the supplier to test them before delivery.

Read Detailed Advice From Blog Articles

Scroll to Top