JPH0513267A - Manufacture of laminated capacitor - Google Patents

Abstract

PURPOSE:To obtain a smaller-sized laminated capacitor which is capable of controlling the length of a gap region between external electrodes with high accuracy and providing excellent reliability. CONSTITUTION:There is provided a laminated body block 11 in which a plurality of laminated capacitor parts 17 to 20 are laid out horizontally separated with a specified span. Grooves 21 to 25 are formed on the laminated body capacitor 11 in such a fashion that the laminated capacitors parts 17 to 20 may be divided by using the grooves. Conductive films 21 and 25 for external electrodes are formed all over both main sides of the laminated body block 11. The laminated body block 11 is cut along the sides of the grooves 21 to 25 so that a pair of external electrode-to-external electrode gap regions may be formed by the use of the cut plane. The above processes constitute the manufacturing process of the laminated capacitor according to the present invention.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer capacitor, and more particularly to a method for manufacturing a multilayer capacitor including a step capable of accurately forming a gap region between a pair of external electrodes.

[0002]

2. Description of the Related Art FIG. 6 is a sectional view showing a conventional multilayer capacitor. The multilayer capacitor 1 has a structure in which a plurality of internal electrodes 3 are arranged in a sintered body 2 made of a dielectric ceramic so as to overlap each other with a dielectric ceramic layer interposed therebetween. A pair of external electrodes 4 and 5 are formed on both end surfaces of the sintered body 2. In the multilayer capacitor 1, it is possible to configure a small-sized and large-capacity capacitor by increasing the number of laminated internal electrodes 3.

However, like other electronic components, the multilayer capacitor 1 is required to be further downsized, and accordingly, the multilayer capacitor 1 using the smaller sintered body 2 is produced. However, when the smaller sintered body 2 is used, the length d of the gap region between the external electrodes 4 and 5 becomes small, which may cause a short circuit between the external electrodes 4 and 5.

In order to prevent the short circuit, the length d of the gap region may be accurately controlled. However, the external electrodes 4 and 5 are generally formed by applying and baking a conductive paste by a dipping method.
Therefore, it is very difficult to accurately control the fog depth of the fog portions 4a and 5a on the side surface of the sintered body 2 of the external electrodes 4 and 5.

[0005]

As described above, in the conventional multilayer capacitor 1, the length d of the gap region between the external electrodes 4 and 5 cannot be accurately controlled, so there is a limit to miniaturization. It was On the other hand, in the single-plate type capacitor 6 shown in FIG. 7, the dielectric plate 7 is coated with a resist, electrodes are formed, and then the resist is removed by etching to form a gap region between the electrodes 8 and 9. 10
a and 10b are accurately formed. Therefore, it is considered that the length d of the gap region between the external electrodes 4 and 5 can be accurately controlled by applying such a method to the manufacturing method of the multilayer capacitor 1.

However, when the electrode forming method as described above is applied to the method for manufacturing a multilayer capacitor, the sintered body 2 is very small, so that the resist cannot be printed with high precision, and therefore the gap region is formed. It is not possible to precisely control the length d of. Also, depending on the solvent used for coating and etching the resist, the multilayer capacitor,
In particular, the internal electrodes 3 may be adversely affected and the reliability may be deteriorated. Further, as a method of applying a resist to a predetermined portion, a method of applying a resist for each laminated capacitor and a method of applying a resist to a mother laminated body at a time using a mask can be considered, but either method is adopted. Even so, it takes time and work cost to apply the resist,
There is also a problem that the cost of the multilayer capacitor is very high.

An object of the present invention is to provide a method capable of accurately controlling the length of the gap region between the external electrodes, and thus manufacturing a smaller and more reliable multilayer capacitor. It is in.

[0008]

According to a method of manufacturing a multilayer capacitor of the present invention, a plurality of multilayer capacitor portions in which a plurality of internal electrodes are opposed to each other in a thickness direction with a dielectric ceramic layer therebetween are at least laterally arranged. And a groove is formed in the laminated body block so as to divide the laterally arranged laminated capacitor portion, and the first and second grooves of the groove are formed. Exposing the internal electrodes connected to one of the potentials on the side surfaces of the laminated body block, forming a conductive film for external electrodes on both main surfaces of the laminated body block, and forming the laminated body block in the groove 1, a step of obtaining a multilayer capacitor in which a gap area between a pair of external electrodes is formed by the cut surface by cutting along the first and second side surfaces.

[0009]

After the laminated body block is obtained, conductive films for external electrodes are formed on the entire surfaces of both main surfaces, and cut along the first and second side surfaces of the groove to form individual laminated capacitor portions. A pair of external electrodes are formed, and the cut surface forms a gap region between the external electrodes. Therefore, as long as the groove is formed with a certain degree of accuracy, the dimension of the surface formed by cutting in the thickness direction of the laminated body block can be accurately controlled, so that the length of the gap region between the pair of external electrodes can be reduced. It can be controlled precisely.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A manufacturing method according to an embodiment of the present invention will be described below with reference to the drawings. First, the laminated body block 11 shown in FIG. 2 is prepared. The laminated body block 11 is formed by laminating a plurality of ceramic green sheets with an internal electrode material interposed therebetween and press-bonding and firing in the thickness direction. That is, in the laminated body block 11, a plurality of internal electrodes 12 to 16 are arranged so as to overlap each other with the ceramic layers interposed therebetween. Further, the plurality of internal electrodes 12 to 16 are formed so as to extend from the one end surface 11 a of the laminated body block 11 to the other end surface 11 b.

A plurality of internal electrodes 12 and a plurality of internal electrodes 1
3 is laminated via a ceramic layer so as to be interleaved with each other, and the first laminated capacitor portion 17 is formed in a portion where the plurality of internal electrodes 12 and the plurality of internal electrodes 13 overlap each other. Has been done. Similarly, the second multilayer capacitor portion 18 is provided at a portion where the plurality of outer electrodes 13 and the plurality of inner electrodes 14 are overlapped with each other with the ceramic layer interposed therebetween.
However, the third multilayer capacitor portion 19 is provided in a portion where the plurality of internal electrodes 14 and the plurality of internal electrodes 15 are sandwiched, and the third multilayer capacitor portion 19 is provided in a portion where the plurality of internal electrodes 15 and the plurality of internal electrodes 16 are overlapped with each other. The multilayer capacitor part 20 of FIG. The laminated body block 11 can be obtained by a conventionally known method for manufacturing a laminated capacitor using a ceramic green sheet.

Next, as shown in FIG. 3, a plurality of grooves 21 to 25 are formed in the laminate block 11 from the end face 11a to the end face 11.
It is formed so as to reach b. The grooves 21 to 23 are formed from the upper surface side of the laminated body block 11, while the grooves 24,
25 is formed from the lower surface side. These grooves 21-2
5 is formed to have a width that divides the multilayer capacitor portions 17 to 20 shown in FIG. 2, and the above-mentioned internal electrodes are exposed on the inner side surfaces of the grooves 21 to 25. For example, to describe the groove 24 as a representative, the first side surface 24 a of the groove 24 is described.
The internal electrode 13 in the first multilayer capacitor portion 17 is exposed to the inside, and the internal electrode 13 in the second multilayer capacitor portion 18 is exposed to the second side surface 24b.
As described above, since the internal electrodes described above are exposed on the inner side surfaces of the grooves 21 to 25, the internal portions that are connected to one potential in the first to fourth multilayer capacitor portions 17 to 20. The electrodes will be exposed on the side surfaces of the grooves 21 to 25.

The grooves 21 to 25 can be formed with high accuracy by using a dicing saw or a laser. Further, as is clear from FIG. 3, the grooves 21 to 2
3 is formed from the upper surface side of the laminated body block 11 and the grooves 24 and 25 are formed from the lower surface side, and these are formed alternately from the upper surface side and the lower surface side of the laminated body block 11,
When the laminated body block 11 is fired after the grooves 21 to 25 are formed, warpage in the laminated body block 11 can be suppressed.

Next, as shown in FIG. 1, conductive films 26 and 27 are formed on the entire upper surface and lower surface of the laminate block 11 described above. The conductive films 26 and 27 can be formed by an appropriate method such as sputtering, vapor deposition or electroless plating. Since the conductive films 26 and 27 are formed on the entire upper surface and lower surface of the laminated body block 11, the grooves 21 to 25 described above are formed.
Will also be formed on the side surface of.

Next, the laminate block 11 is cut along the chain line B in FIG. That is, the laminated body block 11
Is cut along the side surfaces of the grooves 21 to 25. The groove 21
"Along the side surfaces of .about.25" means along the surfaces of the conductive films 26 and 27 on the side surfaces of the groove as shown in FIG. In this way, many laminated bodies 28 shown in FIG. 4 can be obtained. In addition, the laminated body 28 is the above-mentioned first
It is obtained by cutting a portion corresponding to the laminated capacitor portion 17 of. In the laminated body 28 of FIG. 4, the cut surfaces 29 and 30 formed by the above cutting are exposed.

Next, the laminated body 28 shown in FIG. 4 is cut along the alternate long and short dash line X in FIG. 4 to obtain individual laminated body for laminated capacitor, and the laminated capacitor 31 shown in FIG. 5 can be obtained. In the multilayer capacitor 31, a plurality of internal electrodes 33, 34 are laminated in a sintered body 32 with ceramic layers interposed therebetween. The plurality of internal electrodes 33 are based on the internal electrode 12 shown in FIG. 2, and the plurality of internal electrodes 34 are based on the internal electrode 13 shown in FIG.

The plurality of inner electrodes 33 are electrically connected to the outer electrodes 35, and the plurality of inner electrodes 34 are electrically connected to the outer electrodes 36. External electrode 35
Are based on the conductive film 26 shown in FIG. 1, and the external electrodes 36 are based on the conductive film 27. In the obtained multilayer capacitor 31, the length d of the gap region between the pair of external electrodes 35 and 36 is determined by the above-described cut surface 29 of FIG.
It is determined by the width W of 30 (see FIG. 4). Therefore, according to the manufacturing method of the present embodiment, the length of the gap region between the pair of external electrodes 35 and 36 may be controlled by accurately controlling the depths of the grooves 21 to 25 (see FIGS. 1 and 3). It can be seen that d can be accurately controlled. On the other hand, as described above, the grooves 21 to 25 can be formed with high accuracy by using a dicing saw, a laser, or the like.

Therefore, according to the present embodiment, the thickness of the laminated body block 11 is reduced and the smaller laminated capacitor 31 is provided.
Even when trying to obtain, since the length d of the gap region between the external electrodes 35 and 36 can be controlled with high accuracy, a small multilayer capacitor which is less likely to cause a short circuit and has excellent reliability is obtained. be able to.

In the above-described embodiment, the laminated body block 11 includes not only a plurality of laminated capacitor portions 17 to 20 arranged side by side in the direction A of FIG. 2, that is, the lateral direction, but also an end face 11a and an end face 11b. Although a plurality of laminated capacitor portions are also arranged between the end faces 11a and 11b, a laminated body block having a size in which one laminated capacitor portion is arranged may be used. In that case, after forming the conductive film as shown in FIG.
The laminate for individual multilayer capacitors can be immediately obtained by simply cutting along 25.

[0020]

As described above, according to the present invention, by cutting the laminate block along the side surface of the groove formed in the laminate block, the dimension of the gap region between the pair of external electrodes is increased. Since the electrodes are accurately formed, a short circuit between external electrodes can be reliably prevented, and a multilayer capacitor that is smaller and has high reliability can be obtained.

Further, in the present invention, since the groove is simply formed in the laminated body block in order to accurately form the gap region between the external electrodes, an expensive material such as a mask or a resist material is used. Since it can be carried out efficiently without the need for a capacitor, it is possible to provide a small-sized and highly reliable multilayer capacitor at low cost.

[Brief description of drawings]

FIG. 1 is a front view showing a laminated body block on which a conductive film is formed by a manufacturing method according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a laminated body block prepared in an example.

FIG. 3 is a perspective view showing a state in which a groove is formed in the laminated body block.

FIG. 4 is a perspective view showing a laminated body obtained by cutting the laminated body block on the side surface of the groove.

FIG. 5 is a perspective view showing a multilayer capacitor obtained according to an example of the present invention.

FIG. 6 is a sectional view showing a conventional multilayer capacitor.

FIG. 7 is a cross-sectional view showing a conventional single plate type capacitor.

[Explanation of symbols]

 11 ... Laminated block 12-16 ... Internal electrodes 17-20 ... First to fourth laminated capacitor portions 21-25 ... Grooves 26, 27 ... Conductive film 31 ... Laminated capacitors 33, 34 ... Internal electrodes 35, 36 ... External Electrode d ... Length of gap area between external electrodes

Claims (1)

Claim: What is claimed is: 1. A plurality of laminated capacitor portions, wherein a plurality of internal electrodes are arranged so as to face each other with a dielectric ceramic layer interposed therebetween in the thickness direction. And a groove is formed in the laminated body block so as to divide the laminated capacitor portions arranged in the lateral direction, and the first and second grooves of the groove are formed.
Exposing the internal electrodes, which are each expected to be connected to one potential, to the second side surface, and forming a conductive film for external electrodes on both main surfaces of the laminate block. Cutting the laminated body block along the first and second side surfaces of the groove to obtain a plurality of laminated capacitors in which a gap area between a pair of external electrodes is formed by the cut surface. And a method of manufacturing a multilayer capacitor.