Abstract: In accordance with the invention, a semiconductor device having an electrical input/output contact surface is hermetically sealed and provided with connections via a submount such as a two-level ceramic substrate. The device is provided with a contact surface having a sealable peripheral contact and one or more interior contacts. The submount is provided with a peripheral sealable contact corresponding to the device peripheral contact and one or more feed-through contacts corresponding to the device interior contacts. The sealable peripheral contacts surround the interior contacts providing heremetic sealing.