The present disclosure is directed to an electronic assembly and method of forming thereof. The electronic assembly may include a substrate and a first die with first and second opposing surfaces. The first die may be coupled to the substrate at the first surface. At least one first trench may extend partially through the first die from the second surface. A stiffener may be attached to the substrate. The stiffener may have a cavity that accommodates the first die, in which the second surface of the first die faces the stiffener. A thermally conductive layer may be positioned between the stiffener and the first die. The conductive layer at least partially fills the at least one first trench.