JPH1041184A - Method for forming end face electrode of multilayer ceramic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming the end face electrode of a multilayer ceramic capacitor without causing short circuit or any deterioration of insulating resistance or dielectric loss. SOLUTION: A plurality of inner electrodes 2, 3 are arranged in a ceramic body piece 1 and then the inner electrodes 2, 3 are exposed from the body piece 1 before end face electrodes 4, 5 conducting with the inner electrodes 2, 3 are provided. In such a method for forming the end face electrode of a multilayer ceramic capacitor, the body pieces 1 are arranged in matrix such that the exposed faces of the inner electrodes 2 or 3 in the body piece 1 are directed in same direction and then the end face electrodes 4 or 5 is formed while pressing the body pieces arranged in matrix from four sides by means of mask plates 171 -174 . Since the gap between the adjacent body pieces 1 can be decreased, the electrode material can be prevented from intruding through the gap and adhering to the side face of the body piece 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming an end face electrode of a multilayer ceramic capacitor.

[0002]

2. Description of the Related Art Generally, as shown in a perspective view of FIG. 5A and a cross-sectional view taken along the line AA of FIG. One internal electrode 2 and another internal electrode 3 also composed of a plurality of sheets are alternately arranged in a stacked state, and one of the six side surfaces of the main body piece 1 is exposed to the one internal electrode 2. The internal electrode 2 is provided on both the side end surface of the
End electrodes 4 and 5 serving as external electrodes are formed so as to be electrically connected to.

In this case, the end face electrodes 4 and 5 on the left and right end faces of the main body piece 1 are formed by a known method such as sputtering, vacuum deposition or plasma spraying in order to reduce the film thickness and improve the dimensional accuracy. It is formed.

[0004]

In order to form an end face electrode using the above-described method, as shown in FIG. 6A, a frame 7 having a through hole 6 is fixed on a bottom plate 8; The main body piece 1 is formed so that the side end face forming the end face electrode in the through hole 6 faces upward.
6B, a frame 7 having a through groove 9 on a bottom plate 8 is fixed, and an end face electrode is formed in the through groove 9 as shown in FIG. 6B. In some cases, a plurality of body pieces 1 are set side by side so that the side end faces upward, and sputtering or the like is performed in this state.

However, in each case, the through-hole 6 and the through-groove 9 are formed larger than the main-body piece 1 so that the main-body piece 1 can be easily inserted. There is a gap between them. For this reason, when forming the end face electrode of the multilayer ceramic capacitor, the electrode material for connection wraps around and easily adheres to the side surface of the main body piece 1, and not only deteriorates the insulation resistance and dielectric loss of the multilayer ceramic capacitor, short-circuits, but also the external appearance. There is a problem that a defect is caused.

An object of the present invention is to solve the above-mentioned problems and to provide a method of forming an end face electrode which does not cause deterioration of insulation resistance or dielectric loss or short-circuit of a multilayer ceramic capacitor.

[0007]

The present invention has the following configuration to achieve the above object. That is, in the method for forming an end face electrode of a multilayer ceramic capacitor according to the present invention, a plurality of internal electrodes are disposed inside a main body piece made of ceramic, and after exposing the internal electrodes from the main body piece, the internal electrodes are electrically connected to the internal electrodes. In the method of forming an end face electrode of a multilayer ceramic capacitor, the end faces of the main body pieces are arranged in a matrix such that the exposed surfaces of the internal electrodes of the main body pieces face in the same direction. An end face electrode is formed in a state where the four sides are pressed by a mask plate.

Further, the method of forming an end face electrode of a multilayer ceramic capacitor according to the present invention is characterized in that, when the main body pieces are arranged, they are arranged in a matrix so as to be laterally shifted one by one. According to the present invention, the main body pieces are arranged in a matrix, and the gaps between the adjacent main body pieces are reduced by pressing the four sides with the mask plate, thereby preventing the electrode material from entering and adhering to the side surfaces of the main body pieces. can do.

Further, in the present invention, since the main body pieces are arranged side by side in a matrix by being shifted laterally, the gap can be further reduced particularly when the corners of the main body pieces are chamfered.

[0010]

Embodiments of the present invention will be specifically described below with reference to the drawings. First, as shown in FIG. 1 (a), a ceramic slurry in which a dielectric material of titanium oxide, barium titanate, and a Pb-based composite perovskite-type compound is dispersed in an organic binder is used as a raw ceramic sheet by a doctor blade method or the like. A so-called green sheet 11 is formed. A conductive paste 12 containing a metal such as Ag-Pd or Ni is printed on the green sheet 11 by a screen printing method.

Then, as shown in FIG. 1B, a plurality of green sheets 11 on which the conductive paste 12 is printed as described above are prepared, and green sheets having different patterns of the conductive paste 12 are alternately formed. Sheet 1
About 20 to 100 sheets are stacked so that the conductive paste 12 is separated in Step 1. Then, the conductive paste 12 is laminated so as to be sandwiched from above and below by the green sheet 11 on which the pattern is not printed, to form a laminate block 13, and thermocompression-bonded by a thermocompression mold (not shown). After this, the laminate block 1
3 is cut along the cutting line 14 to form the main body piece 1 of the ceramic capacitor.

Next, in order to improve the electrical contact with the end face electrodes formed in the next step, the side end faces (the left and right sides in FIG. 3
Make sure it is exposed. At this time, the corners of the main body piece 1 are chamfered by the polishing. The main body piece 1 formed as described above is aligned by a jig 15 as shown in FIG. 2, and is introduced into a sputtering apparatus for attaching an electrode material. The jig 15 includes a bottom plate 16 and four mask plates 17 _{1 to} 17 ₄ . Since the jig 15 is cleaned with an acid after the end of sputtering, a metal such as stainless steel or aluminum is used as the metal having chemical resistance.

The body pieces 1 of the ceramic capacitor are aligned by using the jig 15 after the exposed surfaces of the internal electrodes 2 or 3 of the body piece 1, that is, the electrode forming surfaces are arranged in a matrix so that they face in the same direction. , The side of the main body piece 1
One of the holding all sides pressurized by the mask plate 17 _{1-17 4.} At this time, the body part 1 and adjacent mask plate 17 ₁ -
17 ₄ since the pressurized so that the aligned without gaps.

[0014] The mask plate 17 _{1-17 4} is provided movably so as to be pressurized according to the number of body part 1 are arranged. With the end face in particular the adjacent mask plate 17 ₂ to the side of the mask plate 17 ₁ is eclipsed disposed so as to contact, disposed such that the end surface adjacent the mask plate 17 ₃ on the side surface of the mask plate 17 ₂ is in contact Be killed. Similarly installed similarly to the mask plate 17 _4. By installing as described above, the mask plates 17 _{1 1}
To 17 ₄ can press to move freely in the direction of the arrow.

Then, the jig 15 on which the main body pieces 1 are arranged is put into a device for adhering an electrode material, for example, a sputtering device, a vacuum evaporation device or a plasma spraying device, and the electrode material is adhered. The multilayer ceramic capacitor shown is completed. The method is first to form an end face electrode 4 on one side end surface of the body part 1, to form a first facet electrode 4 ₁ attached to a metal material such as chromium having high adhesion strength to the ceramic . Next, a metal material such as nickel serving as a barrier metal for preventing solder erosion is adhered to form a _second end surface electrode 42 on the surface of the _first end surface electrode 41, and a metal such as silver having good solderability is formed. a third end face electrodes 4 ₃ are formed on the second end surface electrodes 4 ₂ of the surface of the deposited material.

Further, after one end face electrode 4 is formed,
The jig 15 is covered with a plate of the same size as the bottom plate 16, and the entire jig 15 is turned upside down and the bottom plate 16 is removed to remove the main body piece 1.
Can be exposed on the other side end face, subjected to deposition of the same three types of electrode materials, and 5 ₁ made of a metal material such as chromium, the second facet electrode made of a metal material such as nickel 5 _2, to form a third edge electrode 5 ₃ made of a metal material such as silver.

In the present invention, the adjacent main body pieces 1 are arranged in a matrix so as to make the gap as small as possible when forming the end face electrodes, so that the electrode material does not easily adhere to the side surfaces of the main body pieces 1. Furthermore, in the present invention, the main body pieces 1 are arranged in a matrix by being shifted side by side in a row.
In particular, when the corners of the main body piece 1 are chamfered, the gap can be further reduced.

That is, when the main body piece 1 is cut from the laminate, there is a slight dimensional difference between the main body piece 1 and the main body piece 1 is polished to expose the internal electrodes 4 and 5 from the main body piece 1. The corners are chamfered. Therefore, if the matrix is arranged in the vertical and horizontal directions as described above, FIG.
As shown in the four than becomes relatively large a gap S ₁ is generated at the corner portions are overlapped portion of the body part 1, the electrode material by performing the formation of the end surface electrode in this state to the side surface of the body part 1 May adhere.

Therefore, as shown in FIGS. 4 (b) and 4 (c), by arranging the main body pieces 1 side by side in a row and arranging them in a matrix, a gap S ₂ formed at a corner of the main body piece 1 is formed. ,
Since S ₃ will be formed by only two body pieces 1 adjacent, it is possible to reduce the gap than if arranged in a matrix align the vertical and horizontal. When the main body pieces 1 are arranged in a matrix by being shifted side by side in a row, dummy pieces 18 are inserted in every other row to adjust the shift amount.

Also in this embodiment, the alignment of the main body piece 1 is as follows.
As described above, the mask plates 17 ₁ to 17 ₁ provided on the bottom plate 16
And to reduce the gap between the body part 1 with each other by pressurizing all sides by 17 _4.

[0021]

As described above, according to the formation of the end face electrodes of the multilayer ceramic capacitor according to the present invention, the main body pieces are arranged in a matrix without any gap, and the electrode material is adhered so as to press the four sides with a mask plate. Therefore, it is possible to prevent the electrode material from entering and attaching to the side surface of the main body piece.

Furthermore, in the present invention, since the main body pieces are arranged in a matrix by being shifted side by side in a row, particularly when the corners of the main body pieces are chamfered, the gap formed by the corners is further reduced. be able to.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a part of a process of manufacturing a multilayer ceramic capacitor.

FIG. 2 is an explanatory view showing a method of forming an end face electrode according to the present invention.

FIG. 3 is an explanatory view showing a multilayer ceramic capacitor of the present invention.

FIG. 4 is an explanatory view showing another embodiment of the present invention.

FIG. 5 is an explanatory view showing a conventional multilayer ceramic capacitor.

FIG. 6 is an explanatory view showing a conventional method for forming an end face electrode.

[Description of Signs] 1 Body piece 2, 3 Internal electrode 4, 5 End electrode 16 Bottom plate 17 Mask plate

Claims (2)

[Claims] 1. A multilayer ceramic capacitor in which a plurality of internal electrodes are arranged inside a main body piece made of ceramic, and after the internal electrodes are exposed from the main body piece, an end face electrode is provided so as to conduct with the internal electrodes. In the end face electrode forming method, after the exposed faces of the internal electrodes of the main body piece are arranged in a matrix such that they face in the same direction, the end faces are pressed in a state where the four sides of the main body piece arranged in a matrix are pressed with a mask plate. A method for forming an end face electrode of a multilayer ceramic capacitor, characterized by forming an electrode. 2. The method for forming an end face electrode of a multilayer ceramic capacitor according to claim 1, wherein said matrix-like arrangement is a matrix-like arrangement in which main pieces are shifted laterally one by one.