THERMAL BYPASS FOR STACKED DIES

The disclosed technology relates to microelectronic devices that can dissipate heat efficiently. In some aspects, such a microelectronic device includes a first semiconductor element and at least one second semiconductor element disposed on the first semiconductor element. Such a microelectronic device may further include a thermal block disposed on the first semiconductor element and adjacent to the at least one second semiconductor element. The thermal block may include a conductive thermal pathway to transfer heat from the first semiconductor element to a heat sink disposed on the thermal block. In some embodiments, a coefficient of thermal expansion (CTE) of the thermal block is less than 10 μm/m° C. In some embodiments, a thermal conductivity of the thermal block is higher than 150 Wm-1K-1. at room temperature.