JPH0748449B2 - Method for manufacturing laminated variable porcelain capacitor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a laminated variable porcelain capacitor including a rotor and a stator.

2. Description of the Related Art Conventionally, this type of laminated variable porcelain capacitor has a structure as shown in FIG. In FIG. 3, 1 is a rotor made of a disk-shaped dielectric ceramic, 2 is an internal electrode,
3 is a counter electrode, 4 is a stator including the counter electrode 3, and an oil layer is interposed between the rotor 1 and the counter electrode 3. Reference numeral 5 is an adjustment axis. Capacitance is generated between the internal electrode 2 and the counter electrode 3. Here is a disc-shaped rotor 1
Is formed by stacking ceramic green sheets and punching them with a punching die during molding. In FIG. 4, 6 is a green sheet after punching.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention With such a conventional configuration, when forming the rotor 1 made of a disk-shaped dielectric ceramic as shown in FIG.
It is formed by punching with a die, and the interval between punches needs to be about 1 (mm). For this reason, the material yield is poor at about 60%, and there is a problem that distortion of about 0.02 (mm) occurs in the rotor 1 with a thickness of 0.6 (mm) due to punching, and about 0.01 (mm) in the sintered body. there were.

The present invention solves such a problem, and an object of the present invention is to provide a laminated variable porcelain capacitor element with improved material yield and small rotor distortion.

Means for Solving the Problems In order to solve this problem, the present invention provides a method in which a metal rotor is arranged on a stator composed of a laminated substrate having electrodes inside a dielectric ceramic. A first step of sequentially cutting the stator sheet having the internal electrodes inside the body ceramic into a linear shape in the longitudinal direction; and a plurality of steps of cutting the linearly cut stator sheet into a linear shape in the lateral direction. It has a second step of forming a square or rectangular stator piece, and a third step of combining the plurality of stator pieces with a metal rotor.

Action With this configuration, the material yield is improved, and the warp of the stator made of a dielectric ceramic having internal electrodes can be reduced.

Embodiment 1 FIG. 1 is a sectional view of a laminated variable porcelain capacitor according to an embodiment of the present invention. In FIG. 1, 8 is a stator made of a dielectric ceramic, 9 is an internal electrode, and 10 is a metal rotor. Is.

The stator 8 is obtained by cutting individual pieces from the large plate 7 shown in FIG. 2 with a cutting machine as described above.

Next, Table 1 below shows the material yield of one embodiment of the present invention and the strain during cutting and sintering of the stator 8 and the material yield of the conventional example rotor 1 and the strain during punching and sintering. The thickness before sintering was 0.60 mm, and the thickness after sintering was 0.46 mm.

As is clear from Table 1, the product of the example of the present invention has a material yield improved by 20% as compared with the conventional product, and the strain at the time of cutting is 0.01%.
mm, the strain after sintering is reduced by 0.005 mm.

EFFECTS OF THE INVENTION As described above, according to the present invention, in a laminated type variable porcelain capacitor, a dielectric ceramic having internal electrodes,
By changing from punching to cutting and obtaining individual pieces, the material yield was improved and the strain was reduced. Further, since the dielectric ceramic having the internal electrodes is used for the stator, the stator can be used even if the shape of the stator is square or rectangular when the stator sheet is divided, and the number of steps is reduced and the productivity is improved. Further, since the stator has a laminated structure, it is not necessary to polish the dielectric thinly, cracks do not occur in the rotor or the stator, and the yield can be improved.

Therefore, it is possible to reduce the cost and improve the yield, and it is possible to provide a laminated variable porcelain capacitor of good quality at low cost.

[Brief description of drawings]

FIG. 1 is a sectional view showing a laminated variable porcelain capacitor according to an embodiment of the present invention, FIG. 2 is a plan view showing a cutting method according to an embodiment of the present invention, and FIG. 3 is a conventional laminated variable porcelain capacitor. And FIG. 4 is a plan view showing a large plate punched out by a conventional method. 8 ... Stator, 9 ... Internal electrode, 10 ... Rotor.

Claims (1)

[Claims] 1. A method of manufacturing a laminated variable porcelain capacitor in which a metal rotor is arranged on a stator composed of a laminated substrate having electrodes inside a dielectric ceramic, wherein the stator sheet has internal electrodes inside the dielectric ceramic. In the first step of sequentially cutting linearly in the vertical direction, and sequentially cutting the linearly cut stator sheet in the horizontal direction to form a plurality of square-shaped or rectangular-shaped stator pieces. A method of manufacturing a laminated variable porcelain capacitor, comprising: a second step; and a third step of combining the plurality of stator pieces with a metal rotor.