JP2002141202A - Laminated ceramic electronic component and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated ceramic electronic component which is equipped with outer electrodes that are formed very accurately, nearly uniform in deflection strength, when mounted on a circuit board or the like, and manufactured through a simplified process. SOLUTION: A laminated ceramic electronic component manufacturing method comprises a first process of preparing a mother laminate 5, which is composed of mother ceramic boards 2 which are each equipped with leading electrodes located at its first and second end, laminated through an insulating material layer 6 and formed into one piece, a second process of forming outer electrodes 9 and 10 so as to cover the first and second edge face of the mother laminate 5, a third process of obtaining laminates as unit laminated ceramic electronic components by dividing the mother laminate 6 in Y direction, and a fourth process of forming an insulating film on the sides of the laminate as the unit laminated ceramic electronic component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a laminated ceramic electronic component in which a plurality of ceramic electronic component elements such as a thermistor element are laminated by laminating through an insulating material layer. More specifically, the present invention relates to a method of manufacturing a multilayer ceramic electronic component in which a laminating step and an external electrode forming step are improved, and a multilayer ceramic electronic component obtained by the manufacturing method.

[0002]

2. Description of the Related Art Conventionally, in order to obtain a low resistance and a large capacitance, there are various types of multilayer ceramic electronic components in which a plurality of ceramic electronic component elements are laminated and integrated with each other via an insulating adhesive layer. Proposed.

FIGS. 10 (a) and 10 (b) are a perspective view for explaining an example of this type of conventional multilayer ceramic electronic component and an enlarged sectional view taken along line BB in FIG. 10 (a). FIG.

A multilayer ceramic electronic component 101 has a multilayer body 102 and external electrodes 103 and 104 formed on both ends of the multilayer body 102. In the laminate 102, a plurality of ceramic electronic component elements 105 to 107 are laminated and laminated and integrated via insulating adhesive layers 108 and 109. The electronic component element 105 has a ceramic body 105a and electrodes 105b and 105c formed on the upper and lower surfaces of the ceramic body 105a, respectively.
The electrodes 105b and 105c are respectively drawn to opposing ends of the ceramic body 105a. The external electrodes 103 and 104 are formed so as to be electrically connected to the electrodes 105b and 105c. The laminate 10
2 is covered with the exterior resin layer 110 except for both end faces.

In manufacturing the multilayer ceramic electronic component 101, first, a mother laminate is obtained, and then the mother laminate is cut into laminates 102 of individual multilayer ceramic electronic components 101. And the obtained laminate 1
02 to form an exterior resin layer 110 except for the end face,
External electrodes 103 and 104 are formed on the end surfaces. The external electrodes 103 and 104 are usually obtained by applying and baking a conductive paste and forming a film having good solderability on the electrode layer formed by baking the conductive paste.

[0006]

As described above, the external electrodes 103 and 104 are formed after obtaining the multilayer body of the individual multilayer ceramic electronic component 101 units. Therefore, the external electrodes 103,
When the electrode 104 is formed, there is a problem that the dimensional accuracy of the external electrodes 103 and 104 is not sufficient. For example, the inner edges of the external electrodes 103 and 104 bulge inward, or the inner edges become concave, and
4 tended to vary. For this reason, there is a problem in that, when the semiconductor device is mounted on a substrate, a bonding area with an electrode on the substrate due to solder varies, and the bending strength during mounting varies.

In addition, since the external electrodes must be formed for each individual multilayer ceramic electronic component 101,
There was also a problem that workability was low. An object of the present invention is to provide a method of manufacturing a multilayer ceramic electronic component which can solve the above-mentioned drawbacks of the prior art, can form external electrodes with high precision, and can improve the yield rate and workability in production. An object of the present invention is to provide a multilayer ceramic electronic component.

[0008]

According to a broad aspect of the present invention, there is provided a method for manufacturing a laminated type multilayer ceramic electronic component having a structure in which a plurality of ceramic electronic component elements are laminated via an insulating material layer. A method, comprising: a rectangular plate-shaped ceramic body having first and second opposed ends;
A step of preparing a plurality of mother ceramic substrates having a plurality of electrodes respectively drawn out at the first and second ends, and laminating the plurality of mother ceramic substrates via an insulating material layer; A step of obtaining a mother laminate, an external electrode forming step of forming first and second external electrodes so as to respectively cover the first and second end surfaces of the mother laminate, and after the external electrode forming step, A dividing step of dividing the mother laminate into individual multilayer ceramic electronic component units, and an insulating film covering the side surfaces exposed by the division of the individual multilayer ceramic electronic components obtained in the dividing step. Forming a multilayer ceramic electronic component.

In a specific aspect of the present invention, a break groove for inducing the division in the dividing step is formed in the ceramic substrate of the mother. According to still another specific aspect of the present invention, the electrodes formed on the mother ceramic substrate are respectively formed on the first electrode layer formed on the surface of the ceramic body and on the first electrode layer. A second electrode layer. Preferably, the first electrode layer is made of an electrode material that makes ohmic contact with the ceramic body, and the second electrode layer is made of an electrode material having better solderability than the first electrode layer. Is done.

[0010] In another specific aspect of the present invention, the first and second external electrodes are formed so that the electrodes of the plurality of mother ceramic substrates are electrically connected. In a limited aspect of the present invention, the mother ceramic substrate is made of a resistive ceramic.

In a more limited aspect of the present invention, the resistive material is a semiconductor ceramic having a positive or negative resistance temperature characteristic, thereby forming a multilayer thermistor.

According to another broad aspect of the present invention, a plurality of rectangular plate-shaped ceramic electronic component elements are laminated via an insulating material layer, and the first and second end faces of the ceramic electronic component elements are stacked. The first and second layers are formed so as to cover the stacked body from which the electrode is drawn out and the first or second end face of the stacked body and reach the upper and lower surfaces but not to the side surfaces. A multilayer ceramic electronic component comprising an external electrode and an insulating film covering a side surface of the multilayer body is provided.

In a specific aspect of the multilayer ceramic electronic component according to the present invention, an electrode of the ceramic electronic component element includes a first electrode layer formed on a ceramic surface;
A second electrode layer formed on the first electrode layer.

In a more specific aspect of the multilayer ceramic electronic component of the present invention, the first electrode layer is made of an electrode material that makes ohmic contact with the laminate, and the second electrode layer is formed of the first electrode layer. It is made of an electrode material that is more excellent in solderability.

[0015] In another specific aspect of the multilayer ceramic electronic component of the present invention, the ceramic electronic component element is a resistance element, and preferably, the semiconductor has a positive or negative resistance temperature characteristic as the resistor. Ceramics are used to form a thermistor.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.

With reference to FIGS. 1 to 7, a method of manufacturing a multilayer ceramic electronic component according to this embodiment will be described. In this embodiment, a multilayer thermistor using a semiconductor ceramic having a positive or negative resistance temperature characteristic is obtained as a multilayer ceramic electronic component.

First, as shown in FIG. 2, a rectangular ceramic mother green sheet 1 was prepared. In this embodiment, a ceramic green sheet 1 having a thickness of 0.25 mm was prepared as the mother, but the thickness is not particularly limited. Further, a structure in which a plurality of mother ceramic green sheets are laminated, or a structure in which an internal electrode is formed between a plurality of mother ceramic green sheets may be used.

Break grooves X and Y were formed on one main surface of the mother ceramic green sheet 1, that is, on the upper surface 1a. The interval between the plurality of break grooves X is 5.4 mm.
And the plurality of break grooves Y were formed such that the interval between adjacent break grooves Y was 3.8 mm.

The formation of the break grooves X and Y can be performed by making a cutting blade or the like enter from the upper surface 1a side of the mother ceramic green sheet 1. But the break groove X,
Y is the lower surface 1b of the mother ceramic green sheet 1.
Is formed so as not to reach. The depth of each of the break grooves X and Y is not particularly limited as long as it can induce division in a division step described later. However, it is generally desirable that the depth be 8 to 16% of the thickness of the mother ceramic green sheet 1.

The above-mentioned mother ceramic green sheet 1
Was fired to obtain a rectangular plate-shaped ceramic substrate. This rectangular plate-shaped ceramic substrate was divided along the break grooves X in FIG. 2 to obtain a strip-shaped mother ceramic substrate 2 shown in FIG. This division can be performed by folding the mother ceramic substrate or by cutting along the break groove X using a cutting blade.

Next, the upper surface 2 of the mother ceramic substrate 2
a, a first electrode layer made of an electrode material that can be in ohmic contact with the mother ceramic substrate 2 such as Ni, so as to cover the lower surface 2b and the first and second end surfaces 2c and 2d;
Next, a second electrode layer was formed by a plating method using an electrode material such as Cu having better solderability than the first electrode layer.
Thereafter, the electrode film was polished by, for example, sandblasting so as to divide the electrode film into two electrodes. Thus, the electrodes 3 and 4 shown in FIGS. 4A and 4B were formed.

The electrode 3 is formed from the upper surface 2a of the mother ceramic substrate 2 to the lower surface 2b via the end surface 2c. On the other hand, the electrode 4 is formed so as to reach the upper surface 2a from the lower surface 2b via the end surface 2d. Electrodes 3, 4
Are arranged so as to overlap in the thickness direction via the mother ceramic substrate 2 in the central region in the direction connecting the end surfaces 2c and 2d.

Next, a plurality of mother ceramic substrates 2 on which the electrodes 3 and 4 were formed were attached via an insulating material layer, and were laminated and integrated. The mother laminate thus obtained is shown in FIGS. 5 (a) and 5 (b).

In the mother laminate 5, a plurality of mother ceramic substrates 2 are laminated and integrated via an insulating material layer 6. In the mother laminate 5, insulating layers 7 and 8 are also formed on the upper and lower surfaces. The material forming the insulating material layer 6 is an insulating material, and is not particularly limited as long as the mother ceramic substrates 2 can be laminated and integrated with each other. For example, a binder-containing glass paste, an insulating adhesive, and the like. Can be used. The insulating layers 7 and 8 can be made of the same material.

In this embodiment, a glass paste is used
Insulating material layers 6 to 8 are formed, and are dried after bonding to form a plurality of mother ceramic substrates 2.
Are laminated and integrated.

Next, external electrodes 9 and 10 shown in FIG. 6 were formed on the first and second end faces 5a and 5b (see FIG. 5A) of the mother laminate 5. In this embodiment, the external electrodes 9 and 10 were formed by applying and baking an Ag paste. Of course, the external electrodes 9 and 10 may use another conductive paste, or may be formed by another electrode forming method such as vapor deposition / plating or sputtering.

Next, after forming the external electrodes 9 and 10,
The mother laminate 5 was divided along the dashed line Y in FIG. The dashed line Y is a direction along the break groove Y (see FIGS. 2 and 3), and the division is performed along the break groove Y. That is, since the break groove Y is provided in the ceramic substrate 2 of each mother, division along the dashed line Y in FIG. 6 is induced. Therefore, it is possible to easily obtain a laminate of individual laminated thermistor units. This division can be performed by cutting using a cutting blade in the thickness direction of the mother laminate 5 along the alternate long and short dash line Y.

As described above, the laminated body 11 of each laminated thermistor unit shown in FIGS. 7 and 8 is obtained. In the laminate 11, the side surfaces 11a and 11b are exposed by cutting. Electrodes 3 are provided on the side surfaces 11a and 11b.
4 (not shown in FIG. 7) is also exposed. However, the external electrodes 9A and 1A formed by cutting are
0A does not reach the side surfaces 11a and 11b. That is, the external electrodes 9A and 10A cover the first and second end surfaces 11c and 11d of the multilayer body 11, and the upper surface 11e and the lower surface 1e.
1f, but not to the side surfaces 11a, 11b.

Next, insulating films 12 and 13 shown in FIGS. 1A and 1B are formed so as to cover the side surfaces 11a and 11b. The insulating films 12 and 13 can be made of various insulating materials, and may be made of the same material as the insulating material layer 6 described above, or may be made of another insulating material. Good.

In FIG. 1, the insulating films 12 and 13 are formed so as not to reach the upper surface 11e and the lower surface 11f of the laminate 11, but may be formed so as to reach the upper surface 11e and the lower surface 11f. Good.

According to the manufacturing method of this embodiment, after the external electrodes 9 and 10 are formed on the mother laminate 5, the laminate is divided into individual laminate thermistor units 11 as described above. Therefore, since the external electrodes 9 and 10 may be formed on the relatively large mother laminate 5, the external electrodes 9 and 10 can be formed with high precision. Moreover, in the laminate 11 obtained by the division, the width of the external electrodes 9A and 10A is controlled with high precision by the cutting, and
The external electrodes 9A and 10A do not reach a and 11b.
Therefore, the dimensional accuracy of the external electrodes 9A and 10A can be effectively improved.

Further, since the external electrodes 9 and 10 may be formed at the stage of the mother laminate 5, there is no need to form external electrodes in individual laminate units. Can play.

The effects of the present embodiment will be described based on specific experimental examples. Table 1 below shows the width of the external electrode in the multilayer thermistor obtained by the manufacturing method of the present embodiment and the width of the external electrode in the corresponding multilayer thermistor obtained by the above-described conventional manufacturing method. .
Note that the external electrode width in Table 1 is 10 for each of the embodiment and the conventional example.
The average value of zero stacked thermistors is shown.

[0035]

[Table 1]

As is clear from Table 1, according to the present embodiment, the variation in the width of the external electrodes can be greatly reduced as compared with the conventional method. Further, the bending strength after mounting on a printed circuit board was measured for each of the examples obtained as described above and each of the 100 stacked thermistors obtained by the conventional method. The results are shown in Table 2 below.

[0037]

[Table 2]

As is clear from Table 2, according to the present embodiment, the variation in the flexural strength during mounting can be significantly reduced as compared with the conventional method. Furthermore, comparing the time from obtaining a laminated body to obtaining a laminated thermistor, the work was completed in 13.2 minutes in this embodiment, compared with 61 minutes in the conventional method. Was.

In the above embodiment, the electrodes 3 and 4 are formed so as to reach the end faces 2c and 2d of the mother ceramic substrate 2. However, as shown in FIG.
You may form so that it may not reach on c and 2d. Also in this case, electrodes 3 and 4 are connected to end faces 2c and 2 respectively.
d and an upper edge formed by the upper surface 2a or 2b. That is, the mother ceramic substrate 2 is drawn out to the first and second ends. Further, FIG.
In the mother ceramic substrate 2 shown in (a), after forming an electrode film on the entire upper surface and lower surface, grooves 21 and 22 are formed by sandblasting or the like to form electrodes 3 and 4.
Was formed. Therefore, although the electrode films 23 and 24 remain through the electrodes 3 and 4 and the grooves 21 and 22, the electrode films 23 and 24 do not have to exist as shown in FIG. 9B.

In the above embodiment, the method of manufacturing a multilayer thermistor has been described. However, the present invention can also be applied to a method of manufacturing other multilayer resistance components such as a fixed resistance element and a varistor other than the thermistor. . Further, the present invention can be applied to a method of manufacturing not only a resistance component but also a multilayer electronic component having other functions such as a capacitor.

[0041]

According to the method for manufacturing a multilayer ceramic electronic component of the present invention, first and second external electrodes are formed so as to respectively cover the first and second end faces of the mother laminate.
Thereafter, the mother laminate is divided into individual multilayer ceramic electronic component units. Therefore, since the first and second external electrodes may be formed at the stage of the mother laminate, workability is improved as compared with the case where the external electrodes are directly formed on the laminate of individual multilayer ceramic electronic components. The multilayer ceramic electronic component can be provided at low cost.

Also, at the stage of the mother laminate, the first and second
Since the external electrodes need only be formed, that is, the external electrodes need only be formed on a relatively large mother laminate, the external electrodes of the individual ceramic electronic components are completed by further dividing the mother laminate. Therefore, the dimensional accuracy of the external electrodes can be significantly improved. Therefore, for example, it is possible to reduce the variation in the flexural strength when mounted on a printed circuit board or the like, and to provide an electronic device with excellent reliability.

The break grooves which induce the division in the division step are as follows:
When the mother laminate is formed on the mother ceramic substrate, the mother laminate can be easily and accurately divided.

When the electrode formed on the mother ceramic substrate has the first and second electrode layers, the first and second electrodes
By selecting an electrode material for the electrode layer described above, electrical characteristics such as reliability of electrical connection and thermistor characteristics can be optimized according to the application.

In particular, when the first electrode layer is made of an electrode material capable of making ohmic contact with the ceramic body and the second electrode layer is made of an electrode material having excellent solderability, For example, the thermistor characteristics can be effectively extracted, and an electrode having excellent reliability of electrical connection with an external electrode can be formed.

When the electrodes of the plurality of mother ceramic substrates are electrically connected by the first and second external electrodes, the electronic component elements formed on the plurality of mother ceramic substrates are the first and the second. A multilayer ceramic electronic component that is reliably connected in parallel between the second external electrodes and has low resistance and large capacitance can be provided.

When the ceramic substrate is made of a low antibody, the external electrodes have excellent dimensional accuracy according to the present invention,
In addition, it is possible to efficiently provide a laminated resistance component having a small variation in bending strength at the time of mounting.Especially when the ceramic substrate is made of a semiconductor ceramic having a positive or negative resistance temperature characteristic, According to the present invention, it is possible to provide a laminated thermistor with little variation in external electrode dimensional accuracy, little variation in flexure strength when mounted on a printed circuit board, and excellent productivity.

In the multilayer ceramic electronic component according to the present invention, the plurality of ceramic substrates cover the end faces of the laminated body integrated and laminated via the insulating material layer, and reach the upper and lower surfaces, but the side faces First, as it has not reached
Since the second external electrode is formed and the insulating layer is formed so as to cover the side surface, the variation of the external electrode in the width direction is small, and therefore, the external electrode formation accuracy is excellent and the printed circuit board is mounted. It is possible to provide a multilayer ceramic electronic component in which variation in flexural strength at the time is small. In particular, the multilayer ceramic electronic component according to the present invention,
Since it can be easily obtained according to the manufacturing method of the present invention, the cost of the multilayer ceramic electronic component can be reduced.

In the multilayer ceramic electronic component of the present invention, when the electrode has a structure in which first and second electrode layers are stacked, an electrode material forming the first and second electrode layers is selected. Accordingly, desired electrical characteristics can be reliably obtained, and the reliability of electrical connection between the first and second external electrodes and the electrodes can be improved.
In particular, an electrode material that can make ohmic contact with the thermistor body is used as the first electrode layer, and the second electrode layer is made of an electrode material having better solderability than the first electrode layer. In this case, the thermistor characteristics can be reliably taken out, and a thermistor or the like having excellent electrical connection reliability can be provided.

[Brief description of the drawings]

1A and 1B are a perspective view showing a multilayer thermistor as a multilayer ceramic electronic component manufactured according to an embodiment of the present invention, and a cross section taken along line EE in FIG. 1A. FIG.

FIG. 2 is a perspective view showing a mother ceramic green sheet prepared in one embodiment of the present invention.

FIG. 3 is a perspective view showing a mother ceramic substrate prepared in one embodiment of the present invention.

FIGS. 4A and 4B are a perspective view showing a state in which electrodes are formed on a mother ceramic substrate and a cross-sectional view taken along line CC in FIG. 4A.

5 (a) and 5 (b) are a perspective view showing a mother laminate and a partially cutaway sectional view along DD in FIG. 5 (a).

FIG. 6 is a perspective view showing a state in which first and second external electrodes are formed on a mother laminate.

FIG. 7 is a perspective view showing a laminate obtained by dividing the mother laminate.

8 is a partially cutaway cross-sectional view showing a cross section in a direction parallel to a side surface of the multilayer body shown in FIG.

FIGS. 9A and 9B are cross-sectional views each showing a modification of the shape of an electrode formed on a mother ceramic substrate.

10A and 10B are a perspective view showing an example of a multilayer ceramic electronic component obtained by a conventional manufacturing method, and a partially cutaway enlarged cross-sectional view along line BB in FIG. 10A.

[Explanation of symbols]

 Reference numeral 2: Mother ceramic substrate 2a: Upper surface 2b: Lower surface 2c, 2d: First and second end surfaces 3, 4: Electrodes 5: Mother laminate 6: Insulating material layer 7, 8, ... Insulating layer 9, 10 ... 1st, 2nd external electrode 9A, 10A ... 1st, 2nd external electrode 11 ... laminated body 11a, 11b ... side surface 11c, 11d ... 1st, 2nd end surface 11e ... upper surface 11f ... lower surface 12, 13, ... Insulating film

Claims (12)

[Claims] 1. A method of manufacturing a laminated type multilayer ceramic electronic component having a structure in which a plurality of ceramic electronic component elements are laminated via an insulating material layer, comprising: Providing a plurality of mother ceramic substrates each having a rectangular plate-shaped ceramic body having an end portion, and a plurality of electrodes drawn out from the first and second ends, respectively; Laminating the ceramic substrates through an insulating material layer to obtain a mother laminate, and forming the first and second external electrodes so as to cover the first and second end surfaces of the mother laminate, respectively. Forming an external electrode, and after the external electrode forming step, a dividing step of dividing the mother laminate into individual laminated ceramic electronic component units; and a step of dividing the individual laminated ceramic electronic component obtained by the dividing step. Characterized in that it comprises a step of forming an insulating film so as to cover the side surface which is exposed by the split,
A method for manufacturing a multilayer ceramic electronic component. 2. The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein a break groove for inducing division in the division step is formed in the ceramic substrate of the mother. 3. An electrode formed on a ceramic substrate of the mother comprises: a first electrode layer formed on a surface of a ceramic body; and a second electrode layer formed on the first electrode layer. The method for manufacturing a multilayer ceramic electronic component according to claim 1, further comprising: 4. The electrode material according to claim 1, wherein the first electrode layer is made of an electrode material that makes ohmic contact with the ceramic body, and the second electrode layer is more excellent in solderability than the first electrode layer. The method for manufacturing a multilayer ceramic electronic component according to claim 3, wherein: 5. The multilayer type according to claim 1, wherein said first and second external electrodes are formed so that electrodes of a plurality of mother ceramic substrates are electrically connected to each other. Manufacturing method of ceramic electronic components. 6. The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein the ceramic substrate of the mother is made of resistive ceramic, whereby a multilayer ceramic resistance element is obtained. . 7. The method for manufacturing a multilayer ceramic electronic component according to claim 6, wherein the resistive material is a semiconductor ceramic having a positive or negative resistance temperature characteristic, thereby providing a multilayer thermistor. 8. A plurality of rectangular plate-shaped ceramic electronic component elements are stacked via an insulating material layer, and the first and second ceramic electronic component elements are stacked.
A laminate in which the electrodes of the ceramic electronic component element are drawn out from the end face of the laminate; and a first or second end face of the laminate, which is formed so as to reach the upper and lower faces but not to the side faces. A multilayer ceramic electronic component, comprising: first and second external electrodes; and an insulating film covering a side surface of the multilayer body. 9. The electrode of the ceramic electronic component element,
A first electrode layer formed on the ceramic surface;
The multilayer ceramic electronic component according to claim 8, further comprising: a second electrode layer formed on said electrode layer. 10. The first electrode layer is made of an electrode material that is in ohmic contact with ceramic, and the second electrode layer is
The multilayer ceramic electronic component according to claim 9, wherein the multilayer ceramic electronic component is made of an electrode material having better solderability than the first electrode layer. 11. The multilayer ceramic electronic component according to claim 8, wherein said ceramic electronic component element is a resistance element. 12. The multilayer ceramic electronic component according to claim 11, wherein the resistance element is a thermistor element having a positive or negative resistance temperature characteristic.