JPH0727839B2 - Composite laminated porcelain capacitor - Google Patents

Description

Detailed Description of the Invention a. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated ceramic capacitor, and more particularly to a composite laminated ceramic capacitor having a plurality of independent capacitors having different rated voltages in the same chip.

[Conventional technology]

The miniaturization and high-density mounting of electronic parts are being strongly promoted, and the same holds true for multilayer ceramic capacitors.

A conventional laminated porcelain capacitor is a green ceramic sheet that has a strip-shaped ceramic green sheet on one side of which a plurality of unit internal electrodes of the same shape (eg, strips) are arranged at regular intervals in the width direction of the green sheet. The printed green sheets are provided at regular intervals in the longitudinal direction, and one end of each of the unit internal electrodes constituting the electrode group in the longitudinal direction is exposed (on any edge of the green sheet piece). Punching into a certain size of shape, creating a green sheet piece, stacking this green sheet piece in a prescribed direction and order and thermocompression bonding to make a raw laminated body, and this raw laminated body inside the unit that constitutes the electrode group A single capacitor that is cut at the center of the electrode row interval, or a composite capacitor that includes multiple capacitors in which unit internal electrodes are arranged in parallel without cutting, After finished by form raw chips, baked, it was made into chips by adding external electrode on the end face of the unit internal electrodes are exposed.

[Problems to be Solved by the Invention]

Usually, in an electronic device, there are several types of operating voltages (rated voltages), and the same number of types as the voltages are used.

Since the above-mentioned chip that is a composite capacitor uses a green sheet piece provided with an electrode group in which a plurality of unit internal electrodes are arranged in the same pattern, the independent capacitors in the chip have the same rating (same rating). Capacity, same voltage). Therefore, the conventional composite laminated porcelain capacitor is only effective in increasing the density of independent capacitors of the same type, and has a drawback that the contribution to increasing the density in electronic devices is limited.

The object of the present invention is to provide independent capacitors with different rated voltages,
An object of the present invention is to provide a composite multilayer capacitor which is integrally arranged side by side in the same chip.

B. Structure of the Invention [Means for Solving the Problems] The present invention relates to a unit internal electrode in which an electrode group including a plurality of unit internal electrodes lacks at least one of the unit internal electrodes or moves its position. By stacking multiple green sheet pieces provided with multiple types of electrode groups that are arranged in an array, the opposing structure of the internal electrodes in the stacking direction is determined to form areas with different ratings and A ceramic capacitor having a composite laminated structure having a plurality of different independent capacitors is obtained. That is, a composite laminated ceramic capacitor in which a plurality of green sheet pieces provided with an electrode group composed of a plurality of unit internal electrodes are laminated and sintered to form at least two independent capacitors in an integrated structure. , An electrode group is selected according to the arrangement pattern of the unit internal electrodes constituting each electrode group provided on each of the green sheet pieces, the stacking order is determined, and the interval between the pair of unit internal electrodes opposed to each other in the stacking direction is selected. Is an integral multiple of a green sheet piece, and is a composite laminated ceramic capacitor in which a plurality of regions having different multiples are formed in the same chip to integrally form a plurality of capacitors having different rated voltages.

[Action]

The function and effect of the absence of the unit internal electrodes on the surface of the green sheet is to increase the interval dimension in the stacking direction of the pair of unit internal electrodes in the green sheet thickness dimension unit when the raw chip is formed. , Changing the position of the unit internal electrode to the left and right in the longitudinal direction on the green sheet surface (shift)
Has the effect of increasing the number of types of combinations of exposure directions to be connected to the external electrodes of the unit internal electrodes in the green sheet piece.

〔Example〕

FIG. 1 is a schematic partial vertical external view showing a raw chip of one embodiment according to the present invention exaggerated in the thickness direction, the original outer shape is shown by a chain double-dashed line, and the stacking surface is shown by a broken line. ing.

FIG. 2 shows the minimum unit of the printed green sheet 1 required for producing the raw chip shown in FIG.

The green sheet 2 uses BaTiO ₃ as a dielectric material,
It is a strip-shaped green sheet made of polyvinyl alcohol as a binder and glycol as a plasticizer and having a required thickness (for example, 35 μm). Pd on one side of this green sheet 2
The strip-shaped unit internal electrodes (hereinafter simply referred to as electrodes) 3 made of paste are arranged in two rows in the width direction of the green sheet, and four of the electrode groups are printed as the minimum unit. In the figure, from the left side, the first electrode group has two electrodes 3 arranged in parallel, the second electrode group has only one electrode 3 (the lower electrode is missing in the figure), and the third electrode group The electrode group is formed by arranging two electrodes 3 in parallel and offset from each other (upper right side in the drawing), and the fourth electrode group is the same as the second electrode group.

The green sheet pieces 4A, 4B, 4C, and 4B corresponding to the above-mentioned four electrode groups are formed by punching (punching lines indicated by broken lines) from the printed green sheet 1. As shown in Fig. 1, these green sheet pieces are stacked in order from the bottom, 4A, 4B, 4C, 4B (4D), 4A, 4B, 4C, 4B (4D), 4A, and further, a solid green on top. The sheet pieces 5 are superposed and integrated by thermocompression to form a raw laminated body, and the side surfaces on four sides are cut to adjust the outer shape to complete a raw chip.
In the raw chip, two independent capacitors are juxtaposed side by side, and one capacitor (on the right side in the figure) is a capacitor in which the unit internal electrodes 3 are spaced only by the thickness of the green sheet 2, and the other (in the figure, The capacitor on the left side, which is shown longitudinally at the center of the unit internal electrode 3), is a capacitor in which the distance between the electrodes 3 is twice the thickness of the green sheet 2, and therefore the rated voltages are different from each other. .

The raw chip is fired in the conventional manner, and two external electrodes (not shown) for connecting the exposed ends of the electrodes 3 in the stacking direction are provided on both end faces to form a composite multilayer ceramic capacitor.

FIG. 3 is a partially longitudinal view of a raw chip according to another embodiment of the present invention. In the case of this raw chip, the printed green sheet 1 uses a printed four electrode group composed of the unit internal electrodes 3 arranged in two rows shown in FIG. 4, and the green sheet piece has four electrode groups respectively. There are 4 types of 6A, 6B, 6C, 6D included. The stacking order of the green sheet pieces is 6A, 6 from the top.
B, 6C, 6D, 6C, 6B, 6A, 6B, 6C, 6D. As shown in FIG. 3, a plain green sheet piece 5 is overlaid on the uppermost layer to make a raw chip. The green sheet pieces 6C and 6D are 6A and 6B, respectively.
You may change the direction by 180 degrees and use it instead.

The independent capacitors in the raw chip shown in FIG. 3 are those in which the spacing between the electrodes 3 is only the thickness of the green sheet 2 and three times the thickness (in the figure, the center of the unit internal electrode 3 is shown longitudinally). And.

C. Effects of the Invention The composite laminated ceramic capacitor shown in FIG.
The capacitor with the larger interval has a capacitance of 1 μF and rated voltage.
75V, other capacitors have a capacity of 3.3μF, rated voltage 25
V, the length and width of the chip are 5.6 mm and 9.5 mm, respectively, and the mounting area is 53 mm ² . On the other hand, when the above-mentioned two types of individual capacitors are used, the mounting area is 62 mm ² which is the total of the two chips having the length of 5.6 mm and the width of 5.0 mm and the chip interval. Therefore, in the case of the second embodiment according to the present invention, there is an effect that the mounting area of the capacitor can be reduced by about 15%. In addition, workability is improved because a plurality of capacitors can be supplied by one.

INDUSTRIAL APPLICABILITY The present invention is extremely effective for downsizing an electronic device having several kinds of operating voltages.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view, partly in vertical section, showing an embodiment of the present invention in a raw chip state. FIG. 2 is a plan view showing a printed green sheet and a green sheet piece (a portion surrounded by a dotted line) used for the raw chip of FIG. FIG. 3 is a vertical cross-sectional external perspective view of a raw chip similar to FIG. 1 in another embodiment. FIG. 4 is a plan view showing a printed green sheet used for the raw chip shown in FIG. 3 and a green sheet piece (a portion surrounded by a dotted line). 1 ... Printed green sheet, 2 ... Green sheet, 3 ... Unit internal electrode, 4A to 4D, 6A to 6D ... Green sheet piece, 5 ... Plain green sheet piece.

Claims (1)

[Claims] 1. A plurality of green sheet pieces provided with an electrode portion composed of a plurality of unit internal electrodes arranged in a specific arrangement are laminated in a specific order and sintered to form a plurality of independent capacitors into an integrated structure. In the composite laminated porcelain capacitor described above, in the two independent capacitors, the unit internal electrodes are laminated at a constant interval in units of a predetermined number of green sheet pieces, and the interval is between the two independent capacitors. Composite laminated porcelain capacitor characterized in that