grizedale
Advanced Member level 3
Hello,
I just noticed on a competitor product today, that they have three 500mA LEDs in series on a ~0.8mm PCB with numerous thermal vias to the back copper layer, which is thermal padded to the aluminium heatsink.
The strange thing was that the back copper layer of the PCB was *bare* copper, with no solder resist over it.
-I thought as well as repelling solder, the solder resist layer was there to protect the copper from oxidising?
-So why has this company got bare copper on the back of the PCB?......surely it may react with the chemical of the thermal pad?
-It seems probable that they have neglected to add solder resist in order to get better thermal transfer from the LEDs to the heatsink, but surely that thin, skinny layer of solder resist doesn't hamper thermal transfer that much?
I just noticed on a competitor product today, that they have three 500mA LEDs in series on a ~0.8mm PCB with numerous thermal vias to the back copper layer, which is thermal padded to the aluminium heatsink.
The strange thing was that the back copper layer of the PCB was *bare* copper, with no solder resist over it.
-I thought as well as repelling solder, the solder resist layer was there to protect the copper from oxidising?
-So why has this company got bare copper on the back of the PCB?......surely it may react with the chemical of the thermal pad?
-It seems probable that they have neglected to add solder resist in order to get better thermal transfer from the LEDs to the heatsink, but surely that thin, skinny layer of solder resist doesn't hamper thermal transfer that much?