UV LED circuit


I’m thinking of making a home made UV Led kind of flash light to dry solder mask.
I’m not sure if there is any typical circuit used for this type of small projects but I’m thinking about to use around 20 Leds and a eMosfet to drive these Leds. However, I can’t find much about this. No examples, no circuits already out there, or at least I couldn’t find them.

I’m still trying to decide if it is better to go with THT components or SMD.
I was thinking about something like the following picture:

Any known and typical circuitry out there for something like this?

1$ DC-DC converter from Aliexpres?

The picture you provided looks like a simple LED with a current limiting resistor set up, those are just 5mm LEDs. Do you know what wavelength is needed to cure your solder mask? If you can find 5mm LEDs in the right wavelength you could just take one of those cheap LED flashlights and replace the old LEDs with the new UV LEDs?

What for a DC-DC converter?

Yeah, I just seen a video of someone doing that, but I wanted to do it on my own. I have THT PCBs laying around that I have no other usage for them, I hare resistors, transistors, etc, and I’m not using them for anything!

I’m not sure about the wavelength needed to cure solder masks but I think anything between 320nm and 410nm is ok.

I was thinking about something like this:

Do you want/need an ON/OFF switch?

What is the purpose or function of the mosfet?