JPH08330175A - Ceramic electronic device and its manufacture - Google Patents

Abstract

PURPOSE: To provide a ceramic electronic device, and its manufacture, excellent in the reliability of connection between inner and outer electrodes in which delamination can be prevented by removing the binder surely. CONSTITUTION: An element 3 is applied at the opposite end faces 3a, 3b, where the end parts 2a of inner electrodes 2 are exposed, with a pattern of base metal film 5 where forming parts 7 are mixed with non-forming parts 8. It is then heat-treated in order to remove the binder and an outer electrode 4 conducted with the inner electrode 2 at least through the base metal film 5, is disposed on the plane applied with the base metal film 5. The ratio (opening rate) of the part 7 where the base metal film 5 is formed to the total area of base metal film pattern including both parts 7, 8 is set at 50% or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic electronic component and a method for manufacturing the same, and more particularly, to a ceramic electronic component such as a laminated ceramic capacitor or a laminated LC composite component in which internal electrodes are arranged in a ceramic. And a manufacturing method thereof.

[0002]

2. Description of the Related Art For example, a monolithic ceramic capacitor, which is one of the typical ceramic electronic components, has a ceramic 1
An external electrode 4 which is electrically connected to the internal electrode 2 is provided at both ends of an element (capacitor element) 3 having a plurality of internal electrodes 2 arranged therein.
It is formed by arranging.

In such a monolithic ceramic capacitor, for example, an internal electrode made of a base metal such as Ni or Cu is used as a non-reducing dielectric ceramic (a base metal electrode material such as copper or nickel is not oxidized in the firing process. A ceramic material that has sufficient resistivity and dielectric properties to be used as a dielectric material without being reduced to a semiconductor even when fired in a neutral or reducing atmosphere with a low oxygen partial pressure) There is one that is arranged in.

By the way, in the monolithic ceramic capacitor having the internal electrode made of such a base metal, the base metal (for example, Ni) constituting the internal electrode 2 and the external electrode 4 are used.
In the case where the electrode material (eg Ag-Pd) forming the above does not alloy, a Ni film 5 (FIG. 4) having a film thickness of about 5 to 10 μm is formed as a base layer of the external electrode 4 for the purpose of improving connection reliability. It is considered to be given. In addition, this Ni
The film (base layer) 5 is applied, for example, by dipping the element 3 before firing on a Ni paste 5a spread on a plate 6 as shown in FIG.

Then, the element 3 to which the Ni paste 5a is attached is heat-treated under predetermined conditions to perform debinding (degreasing) and main firing, and then an external electrode paste (eg Ag-Pd paste) is applied, By baking, a monolithic ceramic capacitor having a structure as shown in FIG. 4 is formed.

However, as described above, in a monolithic ceramic capacitor in which a base layer such as a Ni film is provided in order to improve the connection reliability between the internal electrode and the external electrode, the binder is efficiently removed in the firing process of the element. Since it cannot be done, it may cause delamination. That is, the debindering is performed by decomposing and burning the binder by heating the element to a predetermined temperature. When the underlayer such as the Ni film is not formed, it is generated in the debindering step. A considerable portion of evaporative gas, decomposed gas, combustion gas, etc. is discharged from the end face side to the outside along the internal electrode. However, when a base layer such as a Ni film is formed on the entire end face, the evaporative gas However, decomposed gas or combustion gas cannot escape from the end face, which causes delamination.

Regarding the delamination occurrence rate when the Ni film is formed and when the Ni film is not formed, for example, when the Ni film is not formed, the delamination occurrence rate is 0% ( While the number of samples is 500), when the Ni film is formed, the experimental result shows that the occurrence rate of delamination is increased to 5.4% (the number of samples is 500). The results are for a monolithic ceramic capacitor having outer diameter dimensions of 1.6 mm in length × 0.8 mm in width × 0.8 mm in thickness and 40 layers of internal electrodes.

The present invention solves the above-mentioned problems, is capable of reliably debinding and preventing the occurrence of delamination, and has excellent connection reliability between internal electrodes and external electrodes. An object of the present invention is to provide a method for manufacturing a ceramic electronic component and a ceramic electronic component.

[0009]

In order to achieve the above object, a method of manufacturing a ceramic electronic component according to the present invention is directed to an end portion of the internal electrode of an element in which an internal electrode made of a base metal is provided in the ceramic. In the method of manufacturing a ceramic electronic component, wherein an external electrode electrically connected to the internal electrode is provided on the exposed end face, a base metal film is formed on the end face of the element where the end of the internal electrode is exposed, and a formation portion thereof. A step of applying a non-formed portion so as to form a mixed pattern, and after removing the binder by performing a heat treatment, the surface provided with the base metal film is electrically connected to the internal electrode through at least the base metal film. And a step of disposing electrodes.

Further, the ceramic electronic component of the present invention is
An element in which an internal electrode made of a base metal is arranged in a ceramic, and a base metal film having a pattern in which a formed portion and a non-formed portion are mixedly arranged on an end surface of the element where an end portion of the internal electrode is exposed. And an external electrode disposed on an end surface of the element having the base metal film disposed therein and electrically connected to the internal electrode through at least the base metal film.

Further, the ratio (aperture ratio) of the non-formed portion to the entire area of the base metal film pattern including both the formed portion and the non-formed portion is less than 50%.

[0012]

When the base metal film is applied to the end surface of the element where the end portion of the internal electrode is exposed so as to have a pattern in which the formation portion and the non-formation portion are mixed, in the binder removal step, binder decomposition gas and combustion After the gas reaches the end face of the element along the internal electrode, it is released from the part where the base metal film is not formed, so that debinding can be performed quickly and reliably, and delamination can be prevented. You will be able to. Further, after the binder is removed, by providing the external electrode on the surface provided with the base metal film, the external electrode can be surely brought into conduction with the internal electrode mainly through the base metal film. It becomes possible to secure the reliability of the electrical connection.

In the method of manufacturing a ceramic electronic component of the present invention, a method of applying the base metal film so as to form a pattern in which the formed portion and the non-formed portion are mixed is as follows:
For example, it can be formed by printing (applying) a base metal paste in a predetermined pattern on a flat plate made of a rigid material or an elastic material, and pressing a predetermined surface of the element thereon.

In the present invention, the pattern in which the base metal film forming portion and the non-forming portion are mixed is a pattern in which a base metal film is not formed in a grid pattern or a polka dot pattern. It is possible to exemplify various patterns, etc., and there are no particular restrictions on specific patterns.

Further, the ceramic electronic component of the present invention is
On the end face of the element, a base metal film having a pattern in which formation parts and non-formation parts coexist is formed, and since it has a structure in which external electrodes are arranged on it, debinding is prevented in the manufacturing process. It is possible to reliably suppress and prevent the occurrence of delamination and the defective connection between the internal electrode and the external electrode.

It is preferable that the ratio of the non-formation portion of the base metal film to the entire area of the base metal film pattern (aperture ratio) is less than 50%. And the connection reliability between the external electrode and
This is because the desired capacitance cannot be obtained or the equivalent series resistance increases.

[0017]

EXAMPLES The features of the present invention will be described below in more detail with reference to the examples.

In this embodiment, as shown in FIG. 1, a barium titanate (BaTiO ₃ ) based ceramic 1 is provided with a plurality of internal electrodes 2 made of Ni (capacitor element). An example of manufacturing a laminated ceramic capacitor in which external electrodes 4 that are electrically connected to the internal electrodes 2 are provided on both ends of the capacitor 3 will be described.

In this embodiment, first, the ceramic green sheets coated with the Ni paste for the internal electrodes and the upper and lower ceramic green sheets not coated with the Ni paste are stacked and pressure-bonded to each other, and the predetermined size is applied. By cutting at the position, as shown in FIG.
An unfired element 3 was obtained in which the end portions 2a of the internal electrodes 2 were exposed at a and 3b.

Then, as shown in FIG.
On both end faces 3a, 3b of the element 3 where the end 2a of the
The i paste 5a was applied in a grid pattern having an inclination of about 45 °.

Although not shown in particular, in this embodiment, the Ni paste 5a was applied to both end surfaces 3a and 3b of the element 3 by the following method. First, Ni paste was printed (applied) in a grid pattern on a flat plate by screen printing, and one end surface 3a of the element 3 was pressed against this to apply Ni paste 5a, and this was dried. Then, the Ni paste was again printed on the flat plate by screen printing in a grid pattern, and the other end surface 3b of the element 3 was pressed to apply the Ni paste 5a. The method of applying the Ni paste having a predetermined pattern to both end surfaces 3a and 3b of the element 3 is not limited to the above method, and for example, a groove having a predetermined pattern may be formed on a flat plate made of an elastic material. It is possible to easily apply the Ni paste having a predetermined pattern by, for example, a method of forming an element, filling the groove with the paste, and then pressing the element on a flat plate, and other methods can be used. .

Then, the element 3 provided with this Ni film 5 was formed.
Was heat-treated under a predetermined condition to remove the binder, the internal electrodes and the Ni film (base metal film) were baked, and the ceramic was sintered.

Thus, as shown in FIG. 3, an element 3 having Ni films (base metal film) 5 formed in a lattice pattern on both end faces 3a and 3b was obtained.

Then, the external electrodes 4 made of Ag-Pd are formed by coating and baking Ag-Pd paste on both end surfaces 3a, 3b of the element 3 (surfaces provided with the Ni film (base metal film) 5). did.

The opening ratio of the Ni film in the monolithic ceramic capacitor manufactured by the method of the above embodiment,
Table 1 shows the relationship between the delamination occurrence rate and the contact failure occurrence rate (that is, the failure occurrence rate in which the desired capacitance cannot be obtained due to insufficient connection between the internal electrode and the external electrode).

[0026]

[Table 1]

No. 1 in Table 1 shows that the width A of the lattice (that is, the forming portion) 7 shown in FIG. 3 is 0.15 mm, and the width B of the gap (non-forming portion) 8 is 0.10 mm. Aperture ratio is 16%
In the case of No. 2, the width A of the lattice (that is, the forming portion) 7 is 0.15 mm, and the width B of the gap (non-forming portion) 8 is 0.15 mm.
Shows the case where the aperture ratio is 25%.

From Table 1, No. 3 having an aperture ratio of 50-80%
In the case of (Comparative Example), the occurrence rate of contact failure is 20%, whereas in the case of No. 4 (Comparative Example) with an aperture ratio of 100% (no Ni film), the contact failure occurrence rate is 80%. No. 1 and No. 2 with aperture ratios of 16% and 25%
In the case of (all examples within the scope of the present invention), the occurrence rates of delamination and contact failure are both 0%.
You can see that.

In the above embodiments, the multilayer ceramic capacitor has been described as an example, but the present invention is not limited to the multilayer ceramic capacitor, and various internal electrodes are provided in the ceramic such as a multilayer LC composite component. The present invention can be applied to the ceramic electronic component and the manufacturing method thereof, and in that case, the same effect as that of the above embodiment can be obtained.

The present invention is not limited to the above-mentioned embodiment in other points as well, and the kind of material forming the base metal film, the kind of ceramic forming the ceramic electronic component, the internal electrode and the external electrode are formed. Various applications and modifications can be made within the scope of the invention with respect to the types of materials to be used, the types of binders, the temperature conditions and the atmospheric conditions in the binder removal and ceramic firing processes, and the like.

[0031]

As described above, in the method for manufacturing a ceramic electronic component of the present invention, the base metal film having a pattern in which the forming portion and the non-forming portion are mixed is formed on the end surface of the element where the end portion of the internal electrode is exposed. After applying and heat-treating the binder to remove the binder, an external electrode that conducts to the internal electrode mainly through the base metal film is arranged on the surface on which the base metal film is applied, so that the removal is quick and reliable. It becomes possible to use a binder, and it is possible to obtain a highly reliable ceramic electronic component by suppressing and preventing the occurrence of delamination and the defective connection between the internal electrode and the external electrode.

Further, the ceramic electronic component of the present invention is
On the end face of the element, a base metal film having a pattern in which formation parts and non-formation parts coexist is formed, and since it has a structure in which external electrodes are arranged on it, debinding is prevented in the manufacturing process. It is possible to reliably suppress and prevent delamination and poor connection between the internal electrode and the external electrode.

Further, the ratio (opening ratio) of the non-formation portion of the base metal film to the entire area of the base metal film pattern including both the formation portion and the non-formation portion is set to less than 50% so that debinding is prevented. The internal electrode and the external electrode can be reliably connected, and the present invention can be further effectively realized.

[Brief description of drawings]

FIG. 1 is a diagram showing a ceramic electronic component according to an embodiment of the present invention.

FIG. 2 is a diagram showing an element formed in one step of a method for manufacturing a ceramic electronic component according to an example of the present invention.

FIG. 3 is a diagram showing a state in which a base metal film pattern is formed on an end face of an element formed in one step of a method for manufacturing a ceramic electronic component according to an embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional ceramic electronic component.

FIG. 5 is a diagram showing a conventional method for manufacturing a ceramic electronic component.

[Explanation of symbols]

 1 Ceramic 2 Internal Electrode 2a End of Internal Electrode 3 Element (Capacitor Element) 3a, 3b Both End Surfaces of Capacitor Element 4 External Electrode 5 Base Metal Film 5a Ni Paste 7 Base Metal Film Forming Area 8 Base Metal Film Non-Forming Area A Lattice ( Width of forming area B Width of gap (non-forming area)

Claims (3)

[Claims] 1. A ceramic electronic component comprising an element in which an internal electrode made of a base metal is provided in a ceramic, and an external electrode electrically connected to the internal electrode is provided on an end face of the internal electrode where an end portion is exposed. In the manufacturing method, the step of applying a base metal film to the end surface of the element where the end portions of the internal electrodes are exposed so as to form a pattern in which the formation portion and the non-formation portion are mixed, and the binder is removed by performing heat treatment. And a step of arranging an external electrode that is electrically connected to the internal electrode through at least the base metal film on the surface provided with the base metal film. 2. An element in which an internal electrode made of a base metal is provided in a ceramic, and a forming portion and a non-forming portion provided in an end surface of the element where the end portion of the internal electrode is exposed are mixed. A ceramic, comprising: a base metal film having a pattern; and an external electrode, which is provided on an end face of the element on which the base metal film is provided, and which is electrically connected to the internal electrode through at least the base metal film. Electronic components. 3. The ceramic electron according to claim 2, wherein a ratio (aperture ratio) of the non-formation portion to the entire area of the base metal film pattern including both the formation portion and the non-formation portion is less than 50%. parts.