An electronic element which is free of many of the impurities that tend to adversely affect its operation. The electronic element is hermetically sealed in a space formed by a framework having a first and second plate directly joined to its sides. Directly joining the first and second plates to the framework prevents splashes of adhesive and soldering material from effecting the operation of the electronic element.

Manufacturing a piezoelectric vibration device, includes: forming a bonding electrode on a part of a piezoelectric substrate to which a cover makes contact; forming a part defining a through hole to the cover so that a profile of an edge of an opening of the through hole at a first surface of the cover is positioned inside an outer shape of the taking out electrode in a plan view when the cover and the piezoelectric substrate are overlapped; forming a first glass film on the first surface of the cover; forming a second glass film on the first surface of the cover; bonding the first glass film to the taking out electrode as well as the second glass film to the bonding electrode by generating an electric field; and cutting an electrical coupling between the taking out electrode and the bonding electrode after step (e).

A surface mount quartz crystal oscillator has a package body having a bottom wall and a first frame wall laminated on the bottom wall and having a central opening, a quartz crystal blank accommodated in a recess formed in the package body including the central opening, an IC (integrated circuit) chip accommodated in the recess and having at least an oscillator circuit connected to the crystal blank, and a cover for enclosing the recess to hermetically encapsulating the crystal blank and the IC chip within the recess. The first frame wall has a notch portion partially cut into the outer periphery thereof, such that a terminal formed on a portion of the top of the bottom wall exposes in the notch portion. The exposed terminal is, for example, a testing crystal terminal electrically connected to the crystal blank.

An improved packaged semiconductor device is provided having an electronic component, such as an integrated circuit, enclosed within a single layer ceramic PGA package. A cap, of substantially the same areal dimension as the base, is sealed to the base forming a cavity in which the integrated circuit is mounted. Input/output pins are attached to through-holes in the base and extend through the base and are exposed by holes in the cap aligned to the through-holes in the base. Extensive glass sealing of the cap to the base, made possible by the substantially co-extensive nature of the cap with respect to the base, provides a sturdy highly reliable seal making the packaged semiconductor device better able to withstand mechanical stress.

A surface mount crystal unit comprising a crystal blank, a planar mounting substrate made of silicon and a cover having a shape with a recess and made of glass containing ions having high mobility. The mounting substrate and the cover are bonded by means of anode bonding and the crystal blank is hermetically sealed in a case made up of the mounting substrate and the cover. The mounting substrate has connection electrodes used for a connection with the crystal blank and external terminals to be used to surface-mount the crystal unit. The connection electrodes and external terminals are electrically connected.