Laser spot welding is a non-contact process in which a laser is used to create a single weld spot and weld metal. Lasers can pulse light with accurate and reproducible energy and duration. Focusing the pulse on one location (small spot) of the part (adjustable in the range of about 0.1-2.0 mm in diameter) results in very high energy densities. The light is absorbed by the material and causes a "keyhole effect" when the focused beam drills a hole in a piece of metal, vaporizes and melts it. At the end of the pulse, the liquefied metal around the keyhole flows back and solidifies to create a small spot weld. The entire process takes just a few milliseconds.

The laser can emit many pulses per second, allowing either individual "spot" welds or a series of overlapping spot welds by moving either the workpiece or the optics, structurally sound and / or Create airtight laser seam welds.