JPH05152137A - Chip-shaped impedance element and its manufacture - Google Patents

Abstract

PURPOSE:To realize a titled element wherein its impedance is high, its irregularity is small in terms of characteristics and its mass productivity is excellent as a component which is used as measures against noise and which restrains the propagation of high-frequency noise generated from various kinds of electronic apparatuses on which a microcomputer is mounted. CONSTITUTION:A chip-shaped impedance element whose impedance is high and whose irregularity is small can be obtained by providing the following: a ferrite sintered body 11 which is square pillar-shaped or square plate-shaped; an alloy wire 13 which is passed through the central part of the ferrite sintered body 11 and which is composed mainly of silver or copper; and one pair of edge electrodes 12 which have been connected to the allay wire 13 at both end parts of the ferrite sintered body 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip-type impedance element intended for use as a noise countermeasure component and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, a chip type impedance element having an internal conductor provided in a through hole of a ferrite sintered body or a chip type impedance element formed by stacking a ferrite green sheet and an internal conductor as a sintered body has been miniaturized as a noise countermeasure component. Widely used in thin digital devices. In particular, a chip-type composite impedance element that is capable of compact and high-density mounting by integrating a plurality of these chip-type impedance elements is being widely used.

A conventional laminated chip type impedance element will be described below. FIG. 10 is a structural diagram of a conventional laminated chip type impedance element.
In FIG. 10, 1 is a magnetic ferrite, 2 is an end face electrode for extraction, and 3 is an internal conductor. In the conventional laminated chip-type impedance element configured as described above, the internal conductors 3 are printed on a plurality of electrically insulating magnetic ferrite sheets, laminated by lamination or the like, fired and integrated, and conductive paste is applied to the end faces of the sintered body. Is applied and baked to form the end face electrode 2 for manufacturing.

A conventional laminated chip-type composite impedance element will be described. FIG. 11 is a perspective view showing the appearance of a conventional laminated chip-type composite impedance element. FIG. 12 is an exploded perspective view of the conventional laminated chip-type composite impedance element. 4 in the figure
Is a magnetic ferrite, 5 is an end surface electrode for extraction, 6 is an internal conductor, 7 and 8 are magnetic ferrite sheets in which the internal conductors are formed in parallel by printing, and 9 is a magnetic ferrite sheet for covering the front and back surfaces. In the conventional laminated chip-type composite impedance element configured as described above, two sheets of 7, 8 and 9 are alternately stacked, laminated by lamination or the like so that adjacent inner conductors are arranged in a small line, and fired. The integrated body is manufactured by applying and baking a conductive paste on the end surface of the sintered body to form the end surface electrode 5.

[0005]

However, the above-mentioned conventional structure has problems in terms of characteristics and mass productivity due to the product shape. First, in order to obtain a large impedance with the same shape, it is desired that the thickness ratio of the inner conductors 3 and 6 is equal to the width, but the inner conductor formed by printing cannot be made thick. Therefore, a large effective area cannot be obtained when the magnetic field is formed. Secondly, the inner conductors 3, 6 are placed on the magnetic ferrite sheet.
However, if magnetic ferrite is laminated on it, the positions of the inner conductors 3 and 6 cannot be accurately grasped, and the position of the inner conductors 3 and 6 is not in the center when cutting before firing. Will occur. For this reason, not only is it difficult to increase the impedance of the chip-type impedance element, but there is also a problem that it causes variations in the characteristics of products.

The present invention solves the above-mentioned conventional problems, and provides a chip-type impedance element and a manufacturing method which enable mass productivity with high positional accuracy, which cannot be realized by the conventional laminated-type chip-type impedance element. The purpose is to do.

[0007]

In order to achieve this object, the present invention is based on a prism-shaped or rectangular plate-shaped ferrite sintered body and silver or copper as a main component which penetrates through the central portion of the ferrite sintered body. And a pair of end face electrodes electrically connected to the alloy wire at both ends of the ferrite sintered body.

Further, according to the present invention, a prismatic or rectangular plate-shaped ferrite sintered body, a plurality of alloy wires containing silver or copper as a main component and penetrating the ferrite sintered body in parallel, and the ferrite sintered body. 2 has a structure in which a plurality of end face electrode pairs electrically connected to the alloy wire are provided at both ends.

[0009]

According to the present invention, by arranging a plurality of rows of alloy wires containing silver or copper as a main component in parallel on the inner conductor, high impedance can be achieved by efficient magnetic field formation, and the conventional laminated chip type It is possible to provide a chip-type impedance element that has high impedance and excellent mass productivity with less variation than the impedance element.

[0010]

【Example】

(Embodiment 1) A chip type impedance element according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the internal structure of a chip-type impedance element according to the first embodiment of the present invention. In the figure, 11 is a ferrite sintered body, 12 is a thick film end face electrode containing silver as a main component, and 13 is an alloy wire containing silver or copper as a main component.

When a chip type impedance element as shown in FIG. 1 is obtained, as shown in FIG.
An alloy wire 13 containing silver or copper as a main component at regular intervals on a ferrite green sheet 10 made of a Cu system
Are arranged in parallel. However, at this time, as the alloy wire 13 containing silver or copper as a main component, an alloy wire having a diameter of 100 μm or less is used in order to maximize the magnetic field formation. This operation is repeated several times, and finally, the uppermost ferrite green sheet made of Ni-Zn-Cu system is placed to form a molded body by thermocompression bonding, and the protruding alloy wire is cut. Next, FIG. 2 (b)
As shown in Fig. 3, the plate-shaped molded body 14 obtained by cutting this molded body to the standard size is further cut to the standard dimension in the length direction of the internal conductor to obtain the primary divided molded body 15 (Fig. 3 (a )), As shown in FIG. 3 (b), the secondary divided molded body 16 is obtained by cutting and aligning it at a constant interval that is the thickness of the product. This is further illustrated in FIG.
As shown in (a), each shape is trimmed to a dimension that takes into account the shrinkage rate after firing to obtain a third divisional molded body 17, and then they are fired at a temperature of 800 to 1100 ° C. ..
As shown in FIG. 4 (b) after this firing, a thick film electrode paste containing silver or copper as a main component is applied to the end faces of the ferrite sintered body, and this is fired at a firing temperature of ferrite or lower to form the end face electrodes 12. Formed to obtain a chip-type impedance element.

The relationship between the impedance value (Z) at 100 MHz and the conductor resistance value (R) of the thus obtained chip type impedance element is shown in Table 1 together with the values of the conventional chip type impedance element.

[0014]

[Table 1]

From this table, it can be seen that the chip-type impedance element of this embodiment has a lower conductor resistance and a higher impedance than the conventional chip-type impedance element.

(Second Embodiment) Next, a second embodiment of the present invention will be described. The plate-shaped molded body 1 was manufactured in the same procedure as in Example 1.
4 to the standard size, and in the state of FIG. 2 (a), as shown in FIG. 5 (a), a thick film electrode paste containing silver as a main component is applied to form a primary divided molded body 18, Furthermore, FIG.
As shown in FIG. 5B, it is further divided vertically and horizontally into one chip, and as shown in FIG.
And was fired in the temperature range of 800 to 1100 ° C. to form the end face electrode 12. Evaluation was performed in the same manner as in Example 1, and the results are shown in (Table 1).

When the firing temperature is lower than 800 ° C., the ferrite sintered body becomes porous and sufficient impedance cannot be obtained. Further, when the ferrite sintered body is over-sintered when fired at a temperature exceeding 1100 ° C., not only sintering matching of alloy wires cannot be obtained, but also reactions between elements occur, which is not preferable.

The ferrite composition of the system other than that used in the embodiments of the present invention may be used. (Embodiment 3) Next, a third embodiment of the present invention will be described.

FIG. 6 is a perspective view showing the internal structure of the chip-type composite impedance element in this embodiment. In this figure, 11 is a ferrite sintered body, 12a to 12d are thick film end face electrodes containing silver as a main component, and 13 is an alloy wire containing silver or copper as a main component.

When a chip-type composite impedance element as shown in FIG. 6 is obtained, the steps shown in FIGS. 7A, 7B, 8A and 8B are carried out in substantially the same steps as in the first embodiment. After the step shown in FIG. 9, a thick film electrode paste containing silver or copper as a main component is applied to the end surface of the ferrite sintered body as shown in FIG. 9, and they are fired at a temperature of 800 to 1100 ° C. The chip-type composite impedance element thus obtained can reduce crosstalk between adjacent wires by arranging the alloy wires in a fine arrangement.

The relationship between the impedance value (Z) at 100 MHz and the conductor resistance value (R) of one element of the thus obtained chip-type composite impedance element is shown together with the value of the conventional chip-type composite impedance element (Table 2). Shown in.

[0022]

[Table 2]

[0023]

As described above, according to the present invention, the green sheets made of a magnetic material are laminated, and the inner conductor is made of an alloy wire containing silver or copper as a main component. It is possible to realize higher impedance than the conventional laminated body.

[Brief description of drawings]

FIG. 1 is a perspective view showing an internal structure of a chip-type impedance element according to a first embodiment of the present invention.

2A and 2B are perspective views showing the appearance of the same chip type impedance element in a manufacturing process, respectively.

3A and 3B are perspective views showing the appearance of the same chip type impedance element in a manufacturing process, respectively.

4A and 4B are perspective views showing the appearance of the same chip type impedance element in a manufacturing process.

5 (a) and 5 (b) are perspective views showing the appearance of a chip-type impedance element in a manufacturing process according to a second embodiment of the present invention.

FIG. 6 is a perspective view showing the internal structure of a chip-type composite impedance element according to the third embodiment of the present invention.

7A and 7B are perspective views showing the appearance of the same chip-type composite impedance element in a manufacturing process, respectively.

8A and 8B are perspective views showing the appearance of the same chip-type composite impedance element in a manufacturing process.

FIG. 9 is an external perspective view in the manufacturing process of the same chip-type composite impedance element.

FIG. 10 is a perspective view showing an internal structure of a conventional chip-type impedance element.

FIG. 11 is an external perspective view of a conventional chip-type composite impedance element.

FIG. 12 is an exploded perspective view showing an internal structure of the conventional chip-type composite impedance element.

[Explanation of symbols]

 11 Ferrite Sintered Body 12 Thick Film End Surface Electrode 13 Alloy Wire 14 Plate-Shaped Molded Body 15, 18 Primary Split Molded Body 16 Secondary Split Molded Body 17, 19 Third Split Molded Body

Claims (6)

[Claims] 1. A prism-shaped or plate-shaped ferrite sintered body, an alloy wire containing silver or copper as a main component, which penetrates a central portion of the ferrite sintered body, and both ends of the ferrite sintered body. A chip type impedance element comprising a pair of end face electrodes electrically connected to the alloy wire. 2. A prismatic or rectangular plate-shaped ferrite sintered body, a plurality of alloy wires mainly containing silver or copper, which penetrate the ferrite sintered body in parallel, and both end portions of the ferrite sintered body. A chip type impedance element comprising a plurality of end face electrode pairs electrically connected to the alloy wire. 3. The chip-type impedance element according to claim 1, wherein the end face electrode is made of a thick film conductor containing silver or copper as a main component. 4. An alloy wire containing silver or copper as a main component is sandwiched between ferrite green sheets having the same thickness, and laminated.
The chip according to claim 1, wherein a sintered body is obtained by firing at a temperature of ˜1100 ° C., and end face electrode pairs electrically connected to the alloy wire are formed at both ends of the sintered body. Type impedance element manufacturing method. 5. An alloy wire containing silver or copper as a main component is sandwiched between ferrite green sheets having the same thickness to obtain a laminate, and both ends of the laminate are electrically connected to the alloy wire. The method of manufacturing a chip-type impedance element according to claim 1, wherein a thick film end face electrode pair containing silver or copper as a main component is formed and fired in a temperature range of 800 to 1100 ° C. 6. A composite alloy wire containing silver or copper as a main component is sandwiched between ferrite green sheets having the same thickness to obtain a laminate, and both ends of the laminate are electrically connected to the alloy wire. The method for manufacturing a chip-type impedance element according to claim 2, wherein an end face electrode pair containing silver or copper as a main component is formed so as to be connected, and the end face electrode pair is fired in a temperature range of 800 to 1100 ° C.