A method includes performing a first laser shot on a first portion of a top surface of a first package component. The first package component is over a second package component, and a first solder region between the first package component and the second package component is reflowed by the first laser shot. After the first laser shot, a second laser shot is performed on a second portion of the top surface of the first package component. A second solder region between the first package component and the second package component is reflowed by the second laser shot.

A semiconductor device has a substrate. The substrate is disposed on a quartz carrier. An electrical component is disposed over the substrate opposite the quartz carrier. An epoxy-solder paste bump is disposed between the substrate and electrical component. The epoxy-solder paste bump comprises an epoxy and a solder powder disposed in the epoxy. Laser energy is applied to a surface of the substrate through the quartz carrier. The laser energy is converted to thermal energy to reflow the solder powder and cure the epoxy.