Abstract: Disclosed are various embodiments of systems, devices and methods for controlling the thickness of a thermal interface layer in a semiconductor die package. In one embodiment, spherical inclusions of at least a first substantially uniform diameter are suspended in a thermal material, which is then dispensed or metered onto the top surface of a semiconductor die. A heat spreading lid is then placed atop the metered or dispensed mixture of thermal material and spherical inclusions, and a mechanical load applied thereto. The load squeezes the thermal material between the lid and the die until the spherical inclusions of the first diameter form a layer of like-diameter spheres having upper and lower portions which contact the lower surface of the lid and the upper surface of the die, respectively.