JPH058905U - surge absorber - Google Patents

Abstract

(57) [Abstract] [Purpose] A plurality of surge absorbers are formed in a single chip-shaped laminated body to save space during mounting and reduce mounting cost. A varistor green sheet 12 provided with internal electrodes 11 reaching both side edges, and varistor green sheets 14, 1 provided with internal electrodes 13 or 15 reaching one end portion.
6, the number and combination of these sheets 12, 14, 16 are selected, and the sheets 12, 14, 16 are stacked one above the other by pressure bonding and firing to form a chip-shaped laminated body. External electrodes are provided at both ends and an intermediate portion on the outer surface in a state of being electrically connected to respective corresponding internal electrodes, and a plurality of surge absorber elements are formed inside the laminated body.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is a surge absorber that absorbs and removes a voltage surge that intrudes into a line, and more specifically, a single chip component provides line-to-line and line-to-ground surge protection for two lines such as AC lines. It is about a surge absorber that can be.

[0002]

[Prior Art]

 As a measure against an external voltage surge to two lines AA 'and BB' in an AC line as shown in FIG. 7, a ceramic surge absorber 1 and its chip type as shown in FIG. As shown in FIG. 8, a chip surge absorber 2 such as No. 9 is used on the printed circuit board, between line A-A 'and ground G, between line BB' and ground G, and line A-A '. Or install a ceramic surge absorber 1 between BB 'and BB', or as shown in FIG. 9, between line A-A 'and earth G, between line BB' and earth G, and between lines A-A 'and B. The chip absorber 2 was mounted between -B '.

[0003]

[Problems to be solved by the device]

 By the way, the above-mentioned conventional voltage surge countermeasures require three surge absorbers in all cases, which requires time and effort for installation, increases work cost, and requires a large area in terms of space. There is a problem of becoming.

Therefore, the present invention aims to provide a surge absorber that can configure a plurality of varistor elements with one varistor chip, is easy to install, is inexpensive in work, and is advantageous in terms of space. And

[0005]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention uses a varistor green sheet with internal electrodes reaching both side edges and a varistor green sheet with internal electrodes reaching one end, and A combination is selected and laminated, and this is pressure-fired to form a laminated body, and external electrodes connected to the corresponding internal electrodes are provided at both ends and intermediate portions on the outer surface of this laminated body. It was done.

[0006]

[Action]

 Laminated body formed by selecting and combining the number and combination of varistor green sheets provided with internal electrodes reaching both edges and varistor green sheets provided with internal electrodes reaching one end, and then performing pressure bonding firing By providing external electrodes on the outer surface of the device, multiple varistor elements can be configured in one chip laminated body, and mounting work on the printed circuit board can be done easily and space saving can be achieved. ..

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 1 to 6 of the accompanying drawings.

As shown in FIG. 1, in order to form a chip-shaped surge absorber, a varistor green sheet 12 provided with internal electrodes 11 reaching both side edges and a varistor green sheet provided with internal electrodes 13 reaching one end portion. 14 and a varistor green sheet 16 provided with an internal electrode 15 reaching the other end, and intermediate and upper and lower varistor green sheets 17, 18 and 19 in which no internal electrode is formed are prepared. The number and combination of slots is selected.

The illustrated embodiment shows a case of constructing a three-element surge absorber of two line-earth varistor elements and one line-line varistor element, and a varistor green sheet provided with internal electrodes 11 reaching both side edges. A first line-ground varistor element Z ₁ is formed by a combination of 12 and a varistor green sheet 14 provided with an internal electrode 13 reaching one end.

A second line-ground varistor element Z ₂ is formed by a combination of two varistor green sheets 12 and 12 and a varistor green sheet 16 disposed between them, and further two varistor green sheets 14 and 16 are formed. Are combined to form a line-line varistor element Z ₃ .

Each varistor green sheet is made of, for example, a ZnO-based varistor material, and each internal electrode 11, 13, 15, etc. is made of Ag, Pd, or the like. Needless to say, it should be noted that the position where each varistor element is connected is not limited to the above-mentioned position and is arbitrary.

As shown in FIG. 1, a varistor green sheet combined so as to form each of the varistor elements Z ₁ , Z ₂ and Z ₃ described above and an intermediate varistor green sheet between the varistor elements Z ₂ and Z _3. 17 and the varistor green sheets 18 and 19 are arranged on the upper and lower sides, these are piled up and down, and this is pressure-bonded and fired to form a chip-shaped laminated body 20 as shown in FIGS.

Next, external electrodes 21, 22, and 23 are formed on the outer surfaces of both end portions and the intermediate portion of the laminate 20 by plating or thick film coating as shown in FIG.

The external electrodes 21 and 22 at both ends are electrically connected to the internal electrodes 13 and 15, and the intermediate external electrode 23 is electrically connected to the internal electrode 11, whereby an equivalent circuit shown in FIG. A chip-shaped surge absorber 24 including the two line-earth varistor elements Z ₁ and Z ₂ and the line-line varistor element Z ₃ can be obtained.

In the surge absorber 24, as illustrated in FIG. 6, the external electrodes 21 and 22 are overlapped with the line AA ′ provided on the printed circuit board and the line BB ′, and the intermediate external electrode 23 is grounded. If they are mounted so as to overlap with each other, and the external electrodes 21, 22, and 23 are connected to the line and the ground G by soldering or other means, and mounted, then both the line-to-line and line-to-ground are mounted. Enables surge countermeasures.

Since the surge absorber 24 has a laminated structure, the element characteristics of the three-element surge absorber, that is, the varistor voltage, surge withstand capability, etc., are independent by controlling the pattern area of the internal electrodes, the number of laminated layers, and the sheet thickness. Can be adjusted.

Although not shown in the drawing, the first line-earth varistor element Z ₁ and the second line-earth varistor element Z ₂ are laminated and pressure-bonded and fired. If an external electrode is provided on the portion, a two-element surge absorber for line-ground can be constructed.

[0018]

【effect】

 As described above, according to the present invention, a plurality of surge absorber elements can be formed in one chip-shaped laminated body, and it is possible to save space when mounting on a printed circuit board and reduce mounting cost.

Further, since the laminated structure is used, the characteristics of each surge absorber element can be individually controlled by the pattern area of the internal electrodes, the number of laminated layers, and the sheet thickness, and more than one surge is formed in one chip-shaped laminated body. Since the absorber element is formed, it is possible to reduce the characteristic variation among the elements.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a surge absorber according to the present invention.

FIG. 2 is a perspective view of a laminated body in which the surge absorber according to the present invention is laminated and fired.

FIG. 3 is a vertical cross-sectional view of a laminated body obtained by laminating and firing a surge absorber according to the present invention.

FIG. 4 is a perspective view of a surge absorber in which external electrodes are provided on a laminated body obtained by laminating and firing a surge absorber according to the present invention.

FIG. 5 is an equivalent circuit diagram of a surge absorber.

FIG. 6 is a plan view showing a mounted state of the surge absorber.

FIG. 7 is a circuit diagram showing a conventional surge countermeasure.

FIG. 8 is a circuit diagram showing a mounted state of a ceramic surge absorber.

FIG. 9 is a circuit diagram showing a mounted state of a chip surge absorber.

[Explanation of symbols]

11, 13, 15 Internal electrode 12, 14, 16, 17, 18, 19 Varistor green sheet 20 Laminated body 21, 22, 23 External electrode 24 Surge absorber

Claims (1)

[Claims for utility model registration] [Claim 1] A varistor green sheet having internal electrodes reaching both side edges and a varistor green sheet having internal electrodes reaching one end are used, and the number and combination of these sheets are used. A surge absorber in which external electrodes connected to corresponding internal electrodes are provided at both ends and an intermediate portion on the outer surface of the laminated body.