An electronic device package includes a first conductive substrate, a second conductive substrate and a dielectric layer. The first conductive substrate has a first coefficient of thermal expansion (CTE). The second conductive substrate is disposed on an upper surface of the first conductive substrate and electrically connected to the first conductive substrate. The second conductive substrate has a second CTE. The dielectric layer is disposed on the upper surface of the first conductive substrate and disposed on at least one sidewall of the second conductive substrate. The dielectric layer has a third CTE. A difference between the first CTE and the second CTE is larger than a difference between the first CTE and the third CTE.