Surface mount package with high thermal conductivity

A package for use in encapsulating an electronic device is disclosed. In some embodiments, the package includes the following: a dielectric frame having first and second sides, an aperture, a raised shelf portion defined along an internal perimeter of the dielectric frame and extending outwardly from the second side, the raised shelf portion defining a first thickness of the dielectric frame, and a raised sidewall extending outwardly from the second side along an external perimeter of the dielectric frame, the raised sidewall defining a second thickness of the frame, the second thickness being greater than the first thickness; a metallic component bonded to the dielectric frame and extending across the aperture; and a seam weldable, low-profile metallic seal ring bonded to the raised sidewall of the dielectric frame. In some embodiments, the package includes the following: a dielectric frame having first and second sides and an aperture, the dielectric frame having an aperture thickness bordering the aperture; a metallic insert positioned within the aperture, the metallic insert having first and second sides, the metallic insert being sized so as to be movable within the aperture and the metallic insert having an insert thickness that is greater than the aperture thickness of the dielectric frame; a first metallic component bonded to the first side of the metallic insert and extending across the aperture; and a second metallic component bonded to the second side of the metallic insert and extending across the aperture.