Abstract:
Heat spreaders for dissipating heat from semiconductor devices comprise a contact surface located within a recess on an underside of the heat spreader, the contact surface being configured to physically and thermally attach to a semiconductor device, and a trench extending into the heat spreader adjacent to the contact surface sized and configured to receive underfill material extending from the semiconductor device into the trench. Related semiconductor device assemblies may include these heat spreaders and methods may include physically and thermally attaching these heat spreaders to semiconductor devices such that underfill material extends from a semiconductor device into the trench.