Laser micro spot welding offers temperature resistant high strength contacts without filler material. However, due to varying surface absorption properties of copper, the welding quality shows poor reproducibility. To stabilize the process we set up a power control for laser micro spot welding of copper. It consists of a high speed pyrometer and an external micro controller. The subject of the investigations is to apply a constant energy amount using conduction welding to increase the process stability. Using the closed loop control, the standard deviation of pull force for overlap welds is reduced from 3.3N to 1.3N.