JP3401338B2 - Multilayer ceramic capacitor array - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer ceramic capacitor array.

[0002]

2. Description of the Related Art A multilayer ceramic capacitor array in which a plurality of multilayer ceramic capacitors are integrally formed is provided in order to facilitate the mounting work of a surface mounting type multilayer ceramic capacitor and to increase the mounting density. Figure 6
(A) is a plan view of a four-layer monolithic ceramic capacitor array, and (b) is a cross-sectional view taken along the line AA in the figure. In the multilayer ceramic capacitor array, a capacitor element body 23 in which a plurality of ceramic layers 21 and an internal electrode 22 made of a conductive member are laminated, and a plurality of external electrodes 24 electrically connected to the internal electrode 22 are electrically connected by a notch 25. It has a structurally separated structure.

The above-mentioned multilayer ceramic capacitor array is positioned by an image recognition device and mounted on a printed circuit board.

[0004]

Generally, in order to recognize the shape of an electronic component by an image recognition device, the entire shape is grasped by recognizing the corners of the electronic component. Therefore,
When recognizing the shape of the above-mentioned multilayer ceramic capacitor array by the image recognition device, since the multilayer ceramic capacitor array also has the cutouts 25 at the four corners, all the protrusions C _{1 to} C ₈ shown in FIG. Must be recognized. Therefore, the shape cannot be accurately recognized unless 8 points are recognized for each product, and there is a problem that the shape recognition process requires time. Further, since the adjacent recognition points of the protruding portion C ₁ and C ₂ adjacent thereto, similarly C ₃ and C ₄ , C ₅ and C ₆ , and C ₇ and C ₈ are close, In some cases, it was recognized, which was a cause of defective mounting.

Furthermore, since the internal electrode 22 is close to the cutout portion 25, the internal electrode 2 is not formed when the cutout portion 25 is formed.
2 may be exposed. If the internal electrode 22 is exposed,
There are also problems that the internal electrodes 22 are oxidized and deteriorated, and that the adjacent internal electrodes 22 are short-circuited. In view of such a problem, the present invention is to provide a monolithic ceramic capacitor array in which shape recognition is easy and a short circuit can be prevented.

[0006]

The present invention has the following constitution in order to achieve the above object. That is, the multilayer ceramic capacitor array according to claim 1 is provided with a capacitor element body in which a plurality of ceramic layers and internal electrodes made of a conductive member are laminated, a plurality of external electrodes electrically connected to the internal electrodes, and adjacent to each other. In the monolithic ceramic capacitor array having cutouts for electrically separating the external electrodes from each other, the capacitor element body has four corners at all four corners, and the corners are provided with external electrodes. At the same time, the internal electrodes are patterned at a predetermined distance along the shape of the cutout, and the internal electrodes are formed such that the vicinity of the portion connected to the external electrode is relatively narrower than the other portions. It is a feature.

According to a second aspect of the present invention, there is provided a monolithic ceramic capacitor array according to the second aspect, wherein the notch has a diameter of one width of one element.
The width is / 2-1 / 3.

[0008]

According to the monolithic ceramic capacitor array of the present invention, since all four corners are corners, when recognizing the shape by the image recognition device, the shape can be recognized by recognizing 4 points per product. The recognition speed can be improved compared to. Further, since there is a distance between the recognition points, each point can be recognized with high accuracy.

Further, since the internal electrodes are patterned with a margin along the shape of the cutouts, the internal electrodes are not exposed even if a position shift occurs when the cutouts are formed. It is possible to prevent a short circuit between the ceramic capacitors.

[0010]

Embodiments of the present invention will be described below with reference to FIGS. First, FIG. 1A is a plan view of a quadruple laminated ceramic capacitor array according to the present invention, and FIG. 1B is a sectional view taken along line BB. The multilayer ceramic capacitor array of the present invention comprises a ceramic layer 1 mainly composed of titanium oxide or barium titanate as a dielectric material, and a Pb-based complex perovskite compound, and Ag-Pd.
Adjacent to a capacitor body 3 in which a plurality of internal electrodes 2 made of a metal such as Ni, are laminated, and a plurality of external electrodes 4 made of silver or Ag-Pd electrically connected to the internal electrodes 1. It is composed of a notch 5 provided in the capacitor body 3 so as to electrically separate the external electrodes 4 from each other, and in particular, the capacitor body 3 has corners composed of straight portions at four corners, External electrodes 4 are provided at the corners.
That is, since the capacitor body 3 does not have the cutout portion 5, it is a corner portion. Thus, if the four corners of the monolithic ceramic capacitor array are corners, it is sufficient to recognize the four points C _{1 to} C ₄ in the shape recognition by the image recognition device, and the recognition speed can be improved compared to the conventional case. it can.

Further, when the internal electrode 2 is laminated on the ceramic layer 1, it is patterned inward by a predetermined distance L from the position where the notch 5 is formed, so that the positional deviation when the notch 5 is formed. The internal electrodes 2 are not exposed even by the above conditions, so that a short circuit or oxidation between the internal electrodes 2 can be reliably prevented. Regarding the dimensional relationship between the notch 5 and the monolithic ceramic capacitor array, the diameter of the notch 5 is preferably 1/2 to 1/3 of the width W per element, and the closer the shape is to a perfect circle, the more adjacent it is. It is possible to prevent the internal electrodes 2 and the external electrodes 4 from coming into contact with each other and cracks from being generated to break the multilayer ceramic capacitor array.

Next, a method of manufacturing the multilayer ceramic capacitor array of the present invention will be described. First, as shown in FIG. 2, a ceramic slurry, in which a dielectric material such as titanium oxide, barium titanate, or a Pb-based compound perovskite compound is dispersed in an organic binder, is made into a ceramic green sheet by a doctor blade method, so-called green sheet. 6 is formed. On the green sheet 6, a conductive paste 7 containing a metal such as Ag-Pd system or Ni, which becomes an internal electrode, is pattern-printed by a screen printing method. At this time, the conductive paste 7 has a through hole 10 which will be described later and serves as a notch.
Is patterned at a position separated by a predetermined distance from the formation position.

Next, as shown in FIG. 3, a plurality of green sheets 6 on which the conductive paste 7 is pattern-printed as described above are prepared so that the conductive pastes 7 do not face each other.
That is, 20 to 100 sheets are laminated so that the conductive paste 7 is separated by the green sheet 6. Then, the green sheet 6 on which the conductive paste 7 is not pattern-printed
To form a laminated body 8 by sandwiching it from above and below,
Thermocompression bonding is performed with a thermocompression bonding die (not shown).

Next, as shown in FIG. 4, before dividing the laminated body 8 into the capacitor bodies along the vertical dividing lines 9a and the horizontal dividing lines 9b, which correspond to the cutout portions of the multilayer ceramic capacitor array. The through hole 10 is punched out by successively lowering a punch (not shown) to the position. In the present invention, since the through holes 10 are not formed in the portions located at the four corners of the monolithic ceramic capacitor array, the formation time of the through holes 10 can be shortened as compared with the conventional case.
Further, the through hole 10 is formed into a substantially oval shape in plan view, and the notch portion is formed into a perfect circle as much as possible, so that a monolithic ceramic capacitor array that is hard to break can be obtained.

Next, as shown in FIG. 5, the laminated body 8 in which the through holes 10 have been drilled is first sequentially arranged from the vertical dividing line 9a from one end to the vertical dividing line 9a from the other end. By cutting the laminated body 8 into a large number of strips by cutting, and then cutting the strips formed in order from the ends along the lateral dividing holes 9b while keeping the end faces aligned. When cut into each capacitor element body 3, an arcuate notch 5 is formed.

Next, after the plurality of separated capacitor element bodies 3 are placed in a firing furnace and fired, each capacitor element body 3 is fired.
Of the inner electrode 2 is accurately exposed to the outside by polishing the side surface of the capacitor with a barrel or the like, and then a conductive paste made of silver or Ag-Pd is applied to the end surface of the capacitor body 3, and then heat treatment is performed to remove the conductive paste. The multilayer ceramic capacitor array shown in FIG. 1 is completed by baking the capacitor body 3 and forming the external electrodes 4.

[0017]

According to the monolithic ceramic capacitor array of the present invention, since all four corners are corners, when the shape is recognized by the image recognition device, the shape can be recognized by recognizing 4 points per product. The recognition speed can be improved as compared with the conventional one. Further, since there is a distance between the recognition points, each point can be recognized with high accuracy.

Further, since the internal electrodes are patterned with a margin along the shape of the cutouts, the internal electrodes are not exposed even if a position shift occurs when the cutouts are formed. It is possible to reliably prevent a short circuit between the monolithic ceramic capacitors from being oxidized.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a multilayer ceramic capacitor array of the present invention.

FIG. 2 is a perspective view showing a state before stacking in the embodiment of the present invention.

FIG. 3 is a perspective view showing a state after stacking in the embodiment of the present invention.

FIG. 4 is a perspective view showing a state in which a through hole is formed in the embodiment of the present invention.

FIG. 5 is a perspective view showing a cut state in the embodiment of the present invention.

FIG. 6 is a diagram illustrating a conventional multilayer ceramic capacitor array.

[Explanation of symbols]

1 Ceramic layer 2 internal electrodes 3 capacitor body 4 external electrodes 5 notches 6 green sheets 7 Conductive paste 8 laminate 9 dividing line 10 through holes

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Claims (2)

(57) [Claims] 1. A capacitor body in which a plurality of ceramic layers and internal electrodes made of a conductive member are laminated, a plurality of external electrodes electrically connected to the internal electrodes, and an electrical connection between adjacent external electrodes. In the multilayer ceramic capacitor array having cutouts that are electrically separated, the capacitor body has four corners at all four corners, and external electrodes are provided at the corners, and the internal electrodes are cutouts. A multilayer ceramic capacitor array, characterized in that the inner electrodes are patterned along a shape of a portion at a predetermined distance, and the vicinity of a portion connected to the outer electrode is formed relatively narrower than other portions. 2. The diameter of the notch is 1 of the width per element.
2. The multilayer ceramic capacitor array according to claim 1, which has a width of / 2 to 1/3.