A hermetically sealed package includes a lid (14) hermetically bonded to a wafer or substrate (12), with a chamber therebetween defined by a recess (16) in the lid. A circuit device (26) such as MEMS device is provided within the chamber on the substrate. A plurality of vias (41-46) are provided through the substrate, and each have a structure which facilitates a hermetic seal of a suitable level between opposite sides of the substrate. The vias provide electrical communication from externally of the assembly to the device disposed in the chamber.