Microelectronic die package structures formed according to some embodiments may include a substrate and a die having a first side and a second side. The first side of the die is coupled to the substrate, and a die backside layer is on the second side of the die. The die backside layer includes a plurality of unfilled grooves in the die backside layer. Each of the unfilled grooves has an opening at a surface of the die backside layer, opposite the second side of the die, and extends at least partially through the die backside layer.