JP2002110427A - Ceramic circuit element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic circuit element which can obtain high reliability without requiring connection between conductors through via holes and can be manufactured easily. SOLUTION: This ceramic circuit element is formed in such a way that a plurality of green ceramic tapes 11A and 11B, on which conductors 12 and 18 which become the circuit element and terminal electrodes 14 and 14' for leading out the conductors 12 and 18 are respectively formed by printing conductive thick-film paste on the tapes 11A and 11B, is wound or folded in a chip-like shape and the conductors 12 and 18 formed on the tapes 11A and 11B are electromagnetically connected to each other by sintering the chip-like body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic chip type EMI (Electro Magnetic Interfer) used for electronic equipment.
ence) filters or ceramic circuit elements such as ceramic chip type transformers.

[0002]

2. Description of the Related Art FIG. 9 shows a configuration example of a conventional multilayer ceramic chip EMI filter. An EMI filter is a filter circuit that removes electromagnetic noise by combining a coil conductor winding and a capacitance. The coil conductor winding and the capacitor element are formed by laminating a plurality of green sheets as shown in FIG. That is, a conductor pattern is formed on a plurality of ceramic green sheets by screen printing, and is laminated, pressed, molded and sintered.

The ceramic green sheets 1a to 1f are portions for forming coil conductor windings, and have a 1/2 turn or 3/4 turn conductor pattern 2 as shown in the figure.
A via hole is formed in the ceramic green sheet at the end 3 of these conductor patterns, and a dotted line 1 in FIG.
As shown by "0", it is electrically connected to the conductor pattern 2 of the adjacent layer. And green sheet 1
Conductor patterns extend to the side edges at both ends in the longitudinal direction of a, and constitute input / output terminal portions of the coil conductor winding. Therefore, by laminating and pressing the ceramic green sheets 1a to 1f, a coil conductor winding of several turns is formed from the winding start portion 4 to the winding end portion 4 '.

The ceramic green sheets 1g and 1h are provided with capacitor electrodes 5 and 5 'for forming a capacitance. The portion 6 where the electrode 5 provided at the center in the longitudinal direction of the ceramic green sheet 1h extends to the side edge constitutes a lead electrode of the capacitor. Therefore, the ceramic green sheets 1a to 1h are laminated and pressed and sintered at a high temperature to form a coil conductor winding of a conductor and a capacitor electrode for forming a capacitance, and an external electrode corresponding to each lead electrode is formed. Is provided, the ceramic chip EMI filter is completed.

[0005]

As described above, for example, an EMI filter which is a conventional multilayer ceramic chip circuit element is formed by forming a conductor pattern on a plurality of green sheets with a conductor paste by screen printing or the like. Is formed by connecting the conductor patterns between the upper and lower layers.
However, according to such a manufacturing method, by using a punching machine or a laser processing machine for the via hole,
It is necessary to make a fine hole of about 50-100 μm,
In addition, it is necessary to fill the via holes with a conductive thick film paste when laminating the respective patterns. For this reason, the conventional laminated ceramic chip circuit element includes a step of inevitably providing a via hole, a step of accurately aligning the via hole and connecting the upper and lower conductors with a conductive paste, and the like. It took a lot of time and effort.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a ceramic circuit element which can obtain high reliability and can be easily manufactured without requiring connection between conductors by via holes. Aim.

[0007]

According to the first aspect of the present invention,
A plurality of ceramic green tapes formed by printing a conductive thick film paste and a conductor serving as a circuit element of a plurality of ceramic green tapes and a terminal electrode for extracting the conductors to the outside are wound and wound, Alternatively, the ceramic circuit element is formed by bending and molding and sintering into a chip shape, and the respective conductors formed on the plurality of ceramic tapes are electromagnetically coupled to each other.

According to the present invention described above, the connection of the conductor using the via hole is eliminated, and the coil conductor winding or the like can be formed by simply winding or folding the ceramic green tape. The manufacturing cost can be reduced.

According to a second aspect of the present invention, a conductor for forming a coil winding on one of the ceramic green tapes and a conductor for forming a capacitance with the coil windings on the other one of the ceramic green tapes. And are wound and sintered to operate as an EMI filter. This makes it possible to easily manufacture a ceramic chip type EMI filter simply by winding the ceramic green tape on which the conductor pattern is formed, molding and then sintering. Therefore, the ceramic chip E
The reliability of the MI filter can be improved and the manufacturing cost can be reduced.

The invention according to claim 3 is characterized in that conductors are arranged on two ceramic green tapes, and these are folded and sintered to operate as a transformer. This makes it possible to easily manufacture a ceramic chip type transformer without using a via hole, by stacking two ceramic green tapes each having a conductive pattern, sandwiching an insulating sheet, and molding the insulating sheet so that the insulating sheet is folded.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows an EM according to a first embodiment of the present invention.
It is a development view of an I filter. (A) Green tape 1
1A, a conductor 12 serving as a coil winding made of a conductor thick film paste and terminal lead portions 14 and 14 'are formed by printing. Next, as shown in (b), a conductor pattern 18 and a lead electrode portion 19 as shown in the drawing are formed on the green tape 11B. The conductor pattern 18 serves as a capacitor electrode portion, and a capacitance is formed between the conductor pattern 18 and the coil conductor winding 12. And green tape 11A
The green tape 11B is layered and wound into a chip shape. At this time, the winding start portion 16A of the green tape 11A and the winding start portion 16B of the green tape 11B
And roll it up with the end of the green tape.
A and 17B are wound into a cylindrical shape, and the extraction electrode 19 for obtaining the capacitance is positioned so as to be exposed in the middle of the chip shape. This state is shown in FIG. Furthermore, the external terminals 15, 15 'are brought into contact with the lead electrodes 14, 14'.
Is formed by applying a conductive thick film paste, and baked at a temperature suitable for the properties of these green tapes and the conductive thick film paste, for example, 900 ° C.

According to such an EMI filter manufacturing method,
A via hole for connecting a large number of layers as in a conventional multilayer chip EMI filter is not required, thereby making it possible to omit the steps of drilling and positioning the via hole, filling the via hole with a conductive material, and the like. .
Therefore, the structure is simplified, the number of connection points is reduced, the reliability is improved, and the production cost can be reduced.

In the above-described embodiment, the cylindrical ceramic chip EMI filter is shown as shown in FIG. 2 (a). However, before the external terminals 15, 15 'are formed, they are formed into a prismatic shape by pressing. Then, external terminals 15, 15 '
May be provided and fired. As a result, FIG.
The square chip EMI filter having the shape shown in FIG. FIG. 4 shows these equivalent circuit diagrams.

FIG. 3 shows a multi-cavity EMI filter. That is, a conductor pattern 12 for forming a plurality of coil windings is formed on one ceramic green sheet 11A, and a capacitor electrode pattern 18 for forming a capacitance is formed on another ceramic green sheet 11B. Are formed. Then, these green sheets are stacked, wound in the same manner as described above, and individual EMI filters can be formed by cutting portions indicated by dotted lines in the drawing. The subsequent steps are the same as described above. According to such a multi-cavity method, production efficiency can be improved.

FIGS. 5 to 8 show a ceramic circuit element according to a second embodiment of the present invention. This embodiment relates to a foldable ceramic chip transformer, and as shown in FIG.
1B, a conductor 22 serving as a coil winding and terminal electrodes 24, 24 ', 25, 25' for leading out to the outside are formed by printing a conductive thick film paste. Then, as shown in FIG. 6, the two ceramic green tapes 21A, 21A
Ceramic green tape 2 for electrical insulation from 1B
1C is stacked and folded, compression molded, and external connection terminals are provided at both ends of each coil winding and sintered. Thus, a ceramic chip transformer as shown in FIG. 7 is completed. As shown in FIG. 8, the equivalent circuit of the ceramic chip transformer has two windings electromagnetically coupled to each other to form a transformer.

Next, this manufacturing process will be described. First, as shown in FIGS. 5 (a) and 5 (b), two ceramic green tapes are prepared, and a conductor 22 serving as a winding and terminal lead-out electrodes 24, 2 are formed by using a conductive thick film paste.
4 ', 25, 25' are formed by screen printing. And it folds along the vertical line shown by the code | symbol 23 in a figure, and is formed in the shape of a rectangular parallelepiped chip. At this time, as shown in FIG. 6 (c), a plain green sheet without a conductor pattern is interposed to form an insulating layer. Leader electrodes 24, 25, 2
Since 4 'and 25' respectively appear at the four corners of the rectangular parallelepiped ceramic chip shown in FIG. 7, connection electrodes are formed by applying a thick film conductive paste as shown in the figure. Then, by heating at 900 ° C., which is suitable for firing the green tape and the conductive paste, the ceramic green sheet becomes a ceramic sintered body, and the conductive thick film paste becomes a metal conductor. Next, a process such as plating is performed as necessary to complete the ceramic chip transformer shown in FIG.

In this embodiment, an example in which one transformer is formed has been described. However, as shown in FIG. 3, a plurality of coil conductor patterns are simultaneously formed on a green sheet, and these are laminated. By cutting it into a plurality of pieces after folding, a plurality of chip transformers can be manufactured at the same time. According to such a foldable chip transformer, since there is no connection depending on vias as in the conventional multilayer ceramic chip circuit element, reliability is improved, the structure is simplified, and the number of manufacturing steps can be reduced.
The manufacturing cost can be reduced.

In the above embodiment, the example of the ceramic chip EMI filter and the ceramic chip transformer has been described. However, other circuit elements can be formed by the same method.

[0020]

As described above, according to the present invention, a conductor is formed on each of a plurality of ceramic green tapes (sheets), and coil windings are formed by winding or folding the conductors. The ceramic chip circuit element is obtained by the electromagnetic coupling. According to such a circuit element, since there is no connection part by a via hole, it is possible to achieve high reliability and reduce the manufacturing cost.

[Brief description of the drawings]

FIG. 1 shows a ceramic chip E according to a first embodiment of the present invention.
It is a development view of a MI filter, and (a) and (b) show the example of a conductor pattern of two ceramic green tapes.

FIGS. 2A and 2B are perspective views of the ceramic chip EMI filter shown in FIG. 1, in which FIG.
Indicates a square shape.

FIG. 3 shows a modification of FIG. 1, wherein (a) and (b) each show a multi-cavity pattern.

FIG. 4 is an equivalent circuit diagram of the ceramic chip EMI filter shown in FIG.

FIGS. 5A and 5B are development views of a ceramic chip transformer according to a second embodiment of the present invention, wherein FIGS. 5A and 5B show conductor patterns formed on a ceramic green tape, respectively.

6 (a) and 6 (b) each show a step of stacking and folding ceramic green sheets, and FIG. 6 (c) shows a step of stacking and folding plain ceramic green sheets to be an insulating layer.

FIG. 7 is a perspective view showing a stage of completion of the ceramic chip transformer shown in FIG. 5;

FIG. 8 is an equivalent circuit diagram of the ceramic chip transformer.

FIG. 9 is an exploded view of a conventional ceramic chip circuit element, showing an example of a ceramic chip laminated EMI filter.

[Explanation of symbols]

11A, 11B, 21A, 21B Ceramic green tape (sheet) 12, 22 Coil winding conductor pattern 18 Capacitor electrode conductor pattern 15, 15 ', 26, 26', 27, 27 'External electrode

Claims (3)

[Claims] 1. A plurality of ceramic green tapes each having a conductor serving as a circuit element of a plurality of ceramic green tapes and a terminal electrode for leading the conductors out are formed by printing a conductive thick film paste. A ceramic circuit element wherein the conductors formed on the plurality of ceramic tapes are wound or bent and formed into a chip shape and sintered, and the respective conductors formed on the plurality of ceramic tapes are electromagnetically coupled to each other. 2. A conductor to be a coil winding on one of the ceramic green tapes and a conductor for forming a capacitance with the coil windings on another of the ceramic green tapes. The ceramic circuit element according to claim 1, wherein the ceramic circuit element is wound and sintered to operate as an EMI filter. 3. A ceramic circuit element wherein conductors are arranged on each of two ceramic green tapes, which are folded and sintered to operate as a transformer.