Silver Mica Block Condenser and Method of Making the Same

Abstract

A silver mica block condenser wherein a mica plate is fitted with a plurality of silver films as spaced from one another on one surface and with a silver film on the other surface, a glass film is applied to cover the plurality of silver films and the spacings between them, a window or a bay-shaped part is made in a part of the glass film on each silver film and a solder film is applied to cover the glass film on the peripheral edge so as to be in contact with the silver film exposed from each window or to fill each bay-shaped part. This invention relates to block condensers to be used for concentrated constant delay circuits contained in IC (integrated circuits) or DIP (durian packs). The surface to be allowed in the arrangement of this kind of condenser is a rectangle of a width of 5 mm. and length of 18 mm. It is required to arrange several to more than 10 condensers in this area. In the case of forming a large capacity in such small area, if a mica plate is used as a dielectric, it will have to be so thin as to be 10 to 15 microns thick. Therefore, in the construction so far adopted for the conventional silver mica condenser, the mica plate is so thin as to be likely to be broken and that it is difficult to provide a lead leading out the electrode. Therefore, though the silver mica condenser is higher in the stability than thick film condensers and ceramic condensers already used for this kind of use, it has not been used for such use. An object of the present invention is to provide a structure of a silver mica block condenser wherein lead wires can be electrically connected to a plurality of silver films fitted in the form of blocks on the surface of a mica plate so stably that the silver films may not peel off the mica plate. In order to attain this object, in the present invention, by noticing that a glass film on a mica plate obtained by heating a glass frit layer fitted on the surface of the mica plate has a property of strongly bonding with the mica plate, it is made possible to make the electric connection of a lead wire to a silver film strong enough by applying a solder layer connecting the lead wire onto the glass film and connecting the solder layer and silver film with each other through an opening made in the glass film. The drawings show an embodiment of the silver mica block condenser according to the present invention. FIG. 1 is a view showing one surface of a mica plate fitted with silver films on the front and back surfaces. FIG. 2 is a side view of FIG. 1. FIG. 3 is a back view of FIG. 1. FIG. 4 is a view showing a glass film as applied onto the silver films shown in FIG. 1. FIG. 5 is a sectioned side view on line V--V in FIG. 4. FIG. 6 is a view showing a solder film as further applied onto FIG. 4. FIG. 7 is a side view of FIG. 6. FIG. 8 is a magnified sectioned view on line VIII--VIII in FIG. 6.

Patent Drawings (2 sheets)

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Sheet 2