Semiconductor device package with grooved substrate

In a described example, a method for making a packaged semiconductor device includes laser ablating a first groove with a first width and a first depth into a mounting surface of a substrate between landing pads. A first pillar bump on an active surface of a semiconductor device is bonded to a first landing pad; and a second pillar bump on the semiconductor device is bonded to a second landing pad. A channel forms with the active surface of the semiconductor device forming a first wall of the channel, the first pillar bump forms a second wall of the channel, the second pillar bump forming a third wall of the channel, and a surface of the first groove forms a fourth wall of the channel. The channel is filled with mold compound and at least a portion of the substrate and the semiconductor device are covered with mold compound.