A laser apparatus configured for epitaxial-side-down mounting on a heat sink. The laser apparatus includes a semiconductor laser structure and at least one post on a substrate where the laser structure and post are separated from each other by a channel. The laser structure and the posts optionally are coated with a heat-spreading material layer and are configured so that the maximum height of the posts is about the same as the maximum height of the laser structure. When the laser apparatus is mounted to a heat sink in an epi-down configuration using solder applied to the top of the laser structure and the at least one post, the channels between the at least one post and the laser structure provide a relief flow path for the solder and ensure that the laser structure does not come directly into contact with the solder.