A device and method for hermetically sealing a medical device is provided.
In one aspect, a silicon device is coupled to a sensor, such as a
pressure transducer, which benefits from having direct contact with its
environment, which in many cases, is the human body. Thus, a method to
hermetically seal the non-sensing portion of a silicon device while
allowing the sensing portion (e.g. the pressure transducer) to have
direct contact with the body is provided. In one aspect, a silicon chip,
a gold preform and a metallic housing are each primed for sealing and are
assembled. The assembly is then heated to react the gold preform to the
silicon chip and to form a molten gold-silicon alloy in-situ to bind the
metallic housing to the non-sensing portion of the silicon chip. In this
way, the non-sensing portion of the silicon chip is hermetically sealed
and protected from exposure, while still permitting exposure of the
sensing portion to the environment.