Active solid-state devices (e.g. – transistors – solid-state diode – Encapsulated – With specified encapsulant
Patent
1994-12-19
1997-04-22
Saadat, Mahshid D.
Active solid-state devices (e.g., transistors, solid-state diode
Encapsulated
With specified encapsulant
257688, 257689, H01L 2329
Patent
active
056231679
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a semiconductor device and more particularly, to a structure of a glass seal type capacitive device.
BACKGROUND ART
There is known a conventional glass package type capacitive device in which a dielectric film is formed on a surface of a silicon substrate to form a capacitive element and the capacitive element is sealed within a glass container (refer to a Japanese Patent Publication No. 57-26432). This type of capacitive devices have been widely used because the element can be easily made in a microminiaturized form at a high production speed and also can have characteristic values conforming to design values.
In this capacitive device, as shown in FIG. 3, a capacitive element 2 formed of a silicon chip is sealed within a cylindrical glass container 1 and leads 5 and 6 are led out from electrodes 3a and 3b of the capacitive element 2 through solder layers 4a and 4b respectively. Reference numerals 7a and 7b denote a silicon nitride film and a silicon oxide film formed on a surface of a silicon substrate to form a dielectric film by this two-layered film. The electrode 3a is disposed on this dielectric film.
In such a capacitive device, the dielectric film formed on the silicon substrate is as thin as at most several .mu.m. However, when it is desired to obtain a large capacitance, the thin film is sometimes formed to have a thickness of about 10 nm. In the latter case, there is a problem that the device becomes weak when subjected to an external stress.
Further, since a high temperature of 600.degree.-800.degree. C. is required for the glass sealing, when returned to a room temperature, thermal stresses within the glass container cannot escape from inside of the glass container to outside, which means that a stress caused by a difference in expansion coefficients is applied directly to the dielectric film. For this reason, with respect to relatively soft films having a low denseness, that is, insulating films such as silicon oxide films or titanium oxide films formed by a liquid phase growth technique, insulating films formed by a physical vapor phase growth process as a sputtering process or an electron beam vapor deposition process, or insulating films (spin-on glass) made from an alcoholic solution of silanol as its major material, it is highly difficult to assemble or fabricate such a film by a conventional sealing method while maintaining its normal characteristics. Even such a film that is considered to be relatively soft and resistive to stress as a silicon oxide film formed by a thermal oxidation method, a silicon nitride film formed by a plasma chemical vapor deposition (CVD) process, or a composite film thereof, has a problem that such a film, in many cases, tends, to be destroyed or deteriorated in its characteristics by thermal stress during its fabrication.
Further, even when such a film is successfully fabricated into its normal state, there is a problem that the film is susceptible to a drop shock or a thermal shock caused at the time of soldering the element to a circuit substrate.
DISCLOSURE OF THE INVENTION
As described above, the prior art glass package type capacitive device has been defective in that thermal stress cannot escape from inside the glass container and the stress caused by the expansion coefficient difference is applied directly to the dielectric film, resulting in deterioration of its characteristics. In addition, the prior art device has such a problem that the dielectric film is susceptible to a stress caused by a mechanical shock such as a drop and thus liable to be destroyed.
In view of the above circumstances, it is an object of the present invention to provide a glass package type capacitive device which is highly resistive to thermal and mechanical shocks and highly reliable.
In accordance with an aspect of a semiconductor device of the present invention, leads for external connection and a semiconductor element are connected through a conductor having a bent structure or an elastic member within a glass conta
REFERENCES:
patent: 3200310 (1965-08-01), Carman
patent: 3375417 (1968-03-01), Hull
patent: 3533832 (1970-10-01), Volder
patent: 3844029 (1974-10-01), Dibugnara
patent: 4042951 (1977-08-01), Robinson et al.
International Search Report.
International Preliminary Examination Report.
Clark S. V.
Kabushiki Kaisha Komatsu Seisakusho
Saadat Mahshid D.
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