JPS5895809A - Volume variable type laminated chip condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a j1 crr modified & layered chip capacitor.

Hybrid integrated circuits are becoming increasingly popular as highly functional functional components, and it is expected that they will continue to spread further in the future by taking advantage of their characteristics of performance and quality.

This hybrid iJA product circuit has become heavily equipped with chip resistors and chip capacitors for miniaturization and improved performance. Trimming of the resistor can be easily done by cutting or removing the end-stopping ruthenium-based resistor using a laser or sandblasting, but this method is not used for chip capacitors. I couldn't do anything.

Therefore, conventionally, as shown in Fig. 1, dielectric material fg4 is
A method has been proposed in which a part of the capacitor IIjI Chengdu is removed by melting and scattering or polishing off both the electrode (13 and the inside of the electrode (2). Note that (8aXlb) is the terminal electrode. In this method, the capacitance value can be adjusted, but since the internal electrode (2) and the dielectric layer (1) are processed together, the opposing internal electrode (2)
1 (21), or a part of the broken internal electrode (2) remains as electrode powder, reducing the dielectric strength. In particular, the green sheet method is used for chip capacitors with a laminated structure. Alternatively, chip capacitors having a dielectric layer of several tens of micrometers have become commonplace by printing methods, but such capacitors suffer from the above-mentioned problems, making it difficult to use the conventional methods described above.

In view of the above points, an object of the present invention is to provide a variable capacitance multilayer chip capacitor that can greatly adjust the capacitance without causing a short circuit between opposing internal electrodes or a decrease in dielectric strength. do.

That is, the present invention provides a film-like surface electrode connected to one of the penal terminal electrodes on at least one of both surfaces in the stacking direction of a multilayer capacitor having terminal electrodes at both ends. A transparent coating covering the surface electrode! 1
It is equipped with a membrane, and the capacity can be adjusted by cutting the surface electrode with a laser or sandblasting.
High reliability can be achieved without causing a short circuit or a drop in dielectric strength voltage between opposing internal electric currents.

An embodiment of the present invention will be described below based on the drawings6 @
h 2 E d, (4) is the end face electrode (
5a) (5b) is a 1&Peng type capacitor, and this multilayer capacitor (4) has several to tens of layers of dielectric material (6) and internal electrodes (7) alternately laminated. It is. The plurality of internal voltages 111(7) are connected to one jIIIi
Power is alternately distributed between the k connected to the ID wt pole (5a) and the k connected to the other end W pole (5b),
A plurality of pairs of opposing vIL poles are configured. A membrane-shaped surface electrode (6) connected to one end surface (5a) is formed between one of the 1111 surfaces of the layered capacitor (4). , this surface 1i electrode (81) is covered with a transparent protective film (9) to improve its environmental resistance.This protective film (9) may be made of glass, acrylic or epoxy material. , phenol, polyimide, etc. are lacking, and among these, glass coating is the most preferred from the standpoint of reliability.

In the above configuration, in order to adjust the storm value, the surface electrode (8) is cut, for example, in the direction of the arrow (b) at the broken MA&* portion. By increasing the effective area of the hidden "C" surface electrode (8), the desired volume Jlt value can be obtained.This rimming method uses a Nd;YAG laser, a CO, or a laser. , or S i
Sandblasting using C* A1103 powder is preferred.

Nine specific examples will be explained below.

As shown in the fIs1 table below, BaTi is used as the dielectric layer.
Eight types of variable capacitance multilayer chip capacitors with different chip sizes of 8.2 x 1.6 x 1.2 ml and different numbers of chips were fabricated using Ag/PD paste as the surface electrode. The surface electrode was provided only on one side. Glass coat and epoxy resin were used for the insulation. The glass coat was baked at 500"C for 10 minutes, and the epoxy resin was baked at 150"C for 1 hour. curing conditions.

1. By sequentially cutting the surface electrodes of the above-mentioned 81IiA class variable spring-type ll1l single-layer chip capacitors using a Nd; A step-like @臘41L change was obtained.

``Also, for variable capacitance multilayer chip capacitors whose ostensible IT- has been cut by this trimming method'' (,6
A life test was conducted in which the electrodes were continuously energized at 0° C.-95% (7) at high temperature and humidity, but no phenomenon was observed in which the cut surface electrodes were short-circuited to each other.

As explained above, according to the capacitive type multilayer chip capacitor according to the present invention, @a can be easily adjusted without shorting the opposing internal electrodes or reducing the withstand voltage, and high reliability can be achieved. Obtainable.

[Brief explanation of drawings]

Fig. 1 is an IjT diagram of a conventional multilayer chip capacitor, Fig. 2 is a cross-sectional view of a variable capacity multilayer chip capacitor according to an embodiment of the present invention, Φ) is a horizontal view, and Fig. 8 is a cross-sectional view of a variable capacitance multilayer chip capacitor according to an embodiment of the present invention. FIG. 4 is an explanatory diagram of the relationship between the cutting blur of the surface electrode of the variable capacitance type multilayer chip capacitor, the capacitance, and tana in a specific embodiment of the invention. (4)...Multilayer capacitor, (5m) (5b)...
・End face electrode, (8)... Surface electric bridge, (9)... Protective film. Agent Yoshihiro Morimoto Figure 1 A Figure 2 6 ” 4,... Figure 3 Cutting amount

Claims (1)

[Claims] 1. 8iI on at least one of both sides in the stacking direction of the multilayer capacitor with terminal *m1 at the jIAl end.
@Takashi modified layered layer chip capacitor provided with a film-like surface electrode connected to one terminal electrode of the terminal electrode, and provided with a transparent protective film covering the surface 11IL electrode.