JPH08306576A - Electronic part and its manufacture - Google Patents

Abstract

PURPOSE: To provide an electronic part of good product yield. CONSTITUTION: A dielectric ceramic sheet and an inner electrode are laminated and burned and a unit chip 11 whose thickness is 1/2 a finally desired thickness is formed. Then, glass paste is applied to one surface of the unit chip 11 and another unit chip 11 is sticked thereto. Thereafter, it is burned to a softening point of glass or higher and a ceramic element 15 is obtained. Then, an external electrode 17 is formed in both edge faces of the ceramic element 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component and its manufacturing method.

[0002]

2. Description of the Related Art A conventional technique will be described by taking a multilayer ceramic capacitor as an example.

With the miniaturization and weight reduction of electronic devices, monolithic ceramic capacitors have been widely and commonly used.
The product price is also low, and the delivery time is becoming shorter. The important characteristics of the monolithic ceramic capacitor are the temperature characteristics obtained from the material characteristics of the ceramic dielectric and the capacitance value due to the overlapping area of the internal electrodes inside the ceramic. A monolithic ceramic capacitor is manufactured as follows in order to obtain a predetermined temperature characteristic and capacitance value.

First, the internal electrodes 1 are printed on a dielectric ceramic sheet 4 cut into a predetermined size as shown in FIG. 6, and the printed dielectric ceramic sheets 4 are alternately stacked to obtain a predetermined capacitance value. Adjust the number of overlapping. At this time, the dielectric ceramic sheet 4 on which the internal electrodes 1 are not printed as necessary to obtain a predetermined product thickness
Are laminated on the upper and lower layers to obtain a laminated ceramic green block. Then, the laminated ceramic green block is cut into a predetermined size to obtain a green chip which is a chip before firing. After that, firing is performed at a predetermined temperature to obtain fired chips 2. External electrodes 3 are formed on the fired chip 2 to obtain a monolithic ceramic capacitor having predetermined temperature characteristics and capacitance values.

[0005]

However, since the monolithic ceramic capacitor has internal electrodes that form a capacitance inside, it is difficult to correct the capacitance value with a fired chip, and the capacitance yield tends to deteriorate. Is. In particular, the temperature guarantee capacitors have a small capacity tolerance of products and have a wide range of temperature characteristics, so that the yield is poor. Therefore, it is an object of the present invention to provide an electronic component in which a product is not wasted and a manufacturing method thereof.

[0006]

To achieve this object, the present invention is to bond at least two ceramic elements with an adhesive containing glass as a main component to form one electronic component.

[0007]

By this method, it is possible to obtain an electronic component having other characteristics by combining ceramic elements which could not be used out of the standard in the past.
Product waste can be eliminated.

Further, by combining them, an electronic component having desired characteristics can be easily obtained.

Further, by using the adhesive layer containing glass as a main component, it is possible to reduce the reliability of the adhesiveness between the ceramic elements, that is, the difference in the coefficient of thermal expansion between the ceramic elements.

[0010]

EXAMPLE A specific example will be described below by taking a multilayer ceramic capacitor as an example. The product thickness of the multilayer ceramic capacitor is determined by the official product specifications such as JIS and EIAJ. In this embodiment, a method of manufacturing one laminated ceramic capacitor in which two types of fired ceramic elements are bonded together by using glass to form a composite will be described.

First, as shown in FIG. 2, an element (unit chip) 11 of a monolithic ceramic capacitor having a thickness of ½ of the product specification targeted for the thickness 10 is prepared. This is a dielectric ceramic sheet 1 first cut into a predetermined size.
The internal electrodes 13 are printed on the second electrodes 2, the dielectric ceramic sheets 12 on which the internal electrodes 13 are printed are alternately superposed, and the number of superpositions is adjusted so as to obtain a predetermined capacitance value. At this time, in order to obtain a half size of a predetermined product thickness, the dielectric ceramic sheets 12 on which the internal electrodes 13 are not printed are overlapped as necessary to obtain a laminated ceramic green block. Then, the laminated ceramic green block having a predetermined thickness and a predetermined size is cut to obtain a green chip which is a chip before firing. Then, firing is performed at a predetermined temperature to obtain the fired unit chip 11.
The unit chip 11 does not need to have strict capacitance values and temperature characteristics. In this way, the unit chips 11 having various kinds of capacitance values and various kinds of temperature characteristics are prepared.
Next, two types of unit chips 11 are selected in order to obtain the required product characteristics as a laminated ceramic capacitor. FIG.
As shown in FIG. 3, a glass paste 14 composed of a glass frit, a binder, and a solvent is formed on one surface of one unit chip 11.
Apply. After that, the unit chips 11 are attached to each other. The bonded unit chip 11 is fired above the softening temperature of the glass frit to obtain a composite ceramic element 15 as shown in FIG. Since the adhesive layer 16 is formed by using the glass frit for the two types of unit chips 11, and the ceramic element 15 is obtained, it is necessary to prevent the unit chips 11 from peeling due to the difference in thermal expansion coefficient.

Therefore, in the present invention, it is necessary to allow the glass frit to flow sufficiently so that the unit chips 11 are securely bonded to each other on their surfaces. Therefore, the glass paste 14 using non-crystallized glass having a glass softening point of 700 ° C. or less, particularly lead borosilicate glass having excellent fluidity is used.

External electrodes 17 are formed on both exposed end surfaces of the internal electrodes 13 of the ceramic element 15 thus obtained to obtain a monolithic ceramic capacitor having predetermined temperature characteristics and capacitance values as shown in FIG. . If the capacitors have the same temperature characteristics, the total capacitance of the unit chips 11 and the capacitance between the unit chips 11 are the capacitances of the capacitors. The capacitance between the unit chips 11 can be made negligibly small by increasing the thickness of the outermost dielectric ceramic sheet 12 of the original unit chip 11 or providing a layer having a low dielectric constant, and the required capacitance value can be obtained. Can be easily obtained. The temperature characteristic can be easily changed by combining the capacitance value of the unit chip 11 and the temperature characteristic value. As a typical example, FIG. 5 shows changes in component temperature characteristics obtained by combining unit chips 18 and 19 having different temperature characteristic values.

The electronic component of the present invention is a composite product of two or more kinds of ceramics, and the reliability of the composite part at the time of mounting, that is, peeling at the time of soldering becomes a problem. Table 1 shows the softening point and type of glass frit used for bonding and the occurrence rate of peeling depending on the soldering temperature.

[0015]

[Table 1]

The occurrence of peeling is drastically reduced when non-crystallized glass having a glass softening point of 700 ° C. or less is used. A glass paste that uses lead borosilicate glass, which is especially excellent in fluidity 1
The effect is remarkable when 4 is used.

Although the present embodiment shows the combination of two types of unit chips, it is also possible to combine a plurality of unit chips within the allowable range of the product thickness.

In this embodiment, two unit chips 11 having the same thickness are combined to obtain a monolithic ceramic capacitor, but unit chips having different thicknesses may be combined.

It is desirable that the adhesive layer 16 be thinner than the ceramic layer and have a smaller expansion coefficient.
It is desirable to provide a non-applied portion from the outer periphery to the inner side, rather than applying the coating to the entire one surface of 1.

The external electrode 17 may be formed of a conductive resin or a metal paste, but it must be baked at a temperature lower than the softening point of the glass frit in heat treatment.

Further, if the corners of the unit chip 11 are chamfered, it is easier to prevent cracks and breaks.

Further, in this embodiment, an example in which two capacitors are combined has been shown, but three or more capacitors may be combined, or different kinds of components such as a capacitor and a varistor may be combined, and the capacitor 2
When using two or more different types of components such as one and one varistor, it is better to combine components of the same type as far apart as possible, such as placing a varistor between capacitors, in order to improve electrical characteristics such as capacitance error. The effect of is reduced.

Further, when the chip resistors are combined, they are arranged so that they are always on the surface.

[0024]

As described above, according to the present invention, by bonding at least two or more ceramic elements using an adhesive layer containing glass as a main component to form one electronic component, it is possible to use the element out of the conventional standard. By combining the ceramic elements that were not provided, it is possible to obtain an electronic component having another characteristic and to eliminate the waste of the product.

Also, by combining them, an electronic component having desired characteristics can be easily obtained.

Further, by using the adhesive layer containing glass as a main component, it is possible to reduce the reliability of the adhesiveness between the ceramic elements, that is, the difference in the coefficient of thermal expansion between the ceramic elements.

[Brief description of drawings]

FIG. 1 is a sectional view of a monolithic ceramic capacitor according to an embodiment of the present invention.

FIG. 2 is a sectional view of a unit chip according to an embodiment of the present invention.

FIG. 3 is an exploded sectional view of a ceramic element according to an embodiment of the present invention.

FIG. 4 is a sectional view of a ceramic element according to an embodiment of the present invention.

FIG. 5 is a temperature characteristic diagram of a combination of two unit chips having different temperature characteristics according to an embodiment of the present invention.

FIG. 6 is a sectional view of a conventional monolithic ceramic capacitor.

[Explanation of symbols]

 11 unit chip 16 adhesive layer

Claims (6)

[Claims] 1. An electronic component having at least two ceramic elements and an adhesive layer for adhering these ceramic elements, the adhesive layer being a layer containing glass as a main component. 2. The electronic component according to claim 1, wherein the two ceramic elements have different temperature characteristics. 3. The electronic component according to claim 1, wherein the two ceramic elements have different capacitance values. 4. The electronic component according to claim 1, wherein non-crystallized glass having a softening point of glass of 700 ° C. or lower is used. 5. The electronic component according to claim 1, wherein lead borosilicate glass is used as the glass. 6. A method of manufacturing an electronic component, wherein at least two ceramic elements are bonded together by using an adhesive containing glass as a main component.