Laser Soldering PCBs with Xtool F1 Ultra — A New Maker Hack

As I was working with the F1 ultra for my PCB stencil explorations, I got some thoughts on the laser since it can melt metal, and we can deliver the controlled laser on a particular point, so why don't I try with laser solder?!! The solder paste is made out of metal balls and flux, right? Haha, it's a little crazy though

I’ve tested the process with a resistor and another fresh Quentorres PCB and some solder paste. after some repeated experiments by adjusting parameters and other settings in the xTool’s studio I’ve found the setting for the soldering setting using the F1 ultra, one thing I learned the Fiber laser too powerful for this task which melts the component’s pad and pads on the PCB very badly, then switched to the Blue IR laser and adjusted the power setting to just deliver to the solder past for melting and soldering it. and it was a success!!,

Preparation

Since I’ve already had the pads of the Quentorres PCB in the xTool creative space app, I’ve modified the values in the settings, which I found from the tests I’ve done.

You can see that I’ve added the PCB’s outline because I need to cut the outline in a cardboard for registering the PCB, so I can place the PCB exactly where the cut happened, will be resulting accurate mapping results on all pad, I’ve also removed the 1.27 mm pitch 2x5 pin header’s pads which I did not place on the PCB.

Creating a Positioning Jig

As step 1, I’ve placed a 2 mm card board sheet for cutting out the PCB’s outline with masking tapes at its edges for preventing any accidental movements of the current position.

Here is how I perform the outline cutting on the card board, by multiple re-cut by the F1 ultra, I made sure its cut well.

Then I removed the center part carefully without moving neither the cutting plate (aluminum bed) nor the Cardboard.

You can see how I successfully placed the PCB at the center of the cardboard, where the cut happens

🕹️ Initiating Laser Soldering

Then I’ve sent the file to the F1 Ultra for laser soldering, you can see the simulation showing about 9 minutes 36 seconds total, which is just under 10 mins.

And the soldering started as expected with the Blue laser. You can see the process in normal speed here, that lasering on the pads of Xiao Rp2040, which melts the solder paste under it.

Here is the time-lapse of the remaining soldering on the Quentorres board, which was done under 10 mins!!

The final output looks a bit burned in many areas, and even the LEDs are burned as well. I feared that the LEDs wouldn't work while testing. After I did an alcohol cleaning, I noticed the burning was not completely affected on the smaller components, and also, all of them were soldered to the board well.

Testing Quentorres :

Then I connected the board with my PC; luckily, no shortage anywhere, and the Xiao lit up its power LED as well.

I’ve prepared the program according to the pin mapping of the on-board LEDs of the Quentorres Board as per its documentation, then I flashed it to the on-board Xiao RP2040

Ta da.. It’s working!!!!!!!

I've attached the tested Arduino code at the bottom of the documentation

🔚 Conclusion

And that’s a wrap! What began as a stencil-making experiment built off the first part, morphed into a full-on laser soldering adventure — turning the xTool F1 Ultra from a cutting machine into a solder-reflow tool.If you're running a makerspace or tinkering solo in your garage, this process shows how you can push the boundaries of your gear.📖 And yes — this post is the second half of the story. You can catch the earlier part about stencils here and jump in from the ground up.

👉 Check out Part 1: How I Made My Own PCB Solder Paste Stencils at Our Fab Lab📋 Full original write-up on Notion: Stencil Making and Laser Soldering — Full Story

~ Happy Making🙌