JP2012079923A - Overvoltage protection component, and composite electronic component using the same - Google Patents

Abstract

An object of the present invention is to provide an overvoltage protection component capable of preventing discharge between electrodes and a composite electronic component using the same.
The overvoltage protection component of the present invention includes a ground electrode, first and second insulating layers formed on the upper and lower surfaces of the ground electrode, and the first and second insulating layers. A cavity 13 formed in each of the insulating layers 12a and 12b, and first and second electrodes 14 and 15 formed so that a part of the cavity 13 faces the ground electrode 11 through the cavity 13; The first electrode 14 is provided on the upper surface of the first insulating layer 12a, and the second electrode 15 is provided on the lower surface of the second insulating layer 12b.
[Selection] Figure 1

Description

  The present invention relates to an overvoltage protection component used to protect various electronic devices such as a digital device, an AV device, and an information communication terminal from an overvoltage caused by static electricity or the like, and a composite electronic component using the same.

  As shown in FIG. 6, this type of conventional overvoltage protection component is laminated as a pair of antistatic units 2 above and below an inductor unit 1 (common mode noise filter) having two coils 1a. The countermeasure unit 2 is provided on the insulating layer 4, a pair of electrodes 3 connected to the inductor unit 1 via an external electrode, a ground electrode 5 formed via the pair of electrodes 3 and the insulating layer 4. The tip of the pair of electrodes 3 and the ground electrode 5 were opposed to each other through the cavity 6.

  In general, the inductor unit 1 has a function as a noise filter, and no current flows through the static electricity countermeasure unit 2. However, when an overvoltage such as static electricity is applied, a discharge occurs between the pair of electrodes 3 and the ground electrode 5. As a result, an electronic device is protected by passing an overvoltage current to the ground.

  As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.

JP 2006-294724 A

  In the conventional overvoltage protection component described above, when an overvoltage is applied between the pair of electrodes 3 and the ground electrode 5, the pair of electrodes 3 are formed on the same surface. There was a problem of the possibility of discharging. In particular, as shown in FIG. 7, when the number of the hollow portions 6 is one, the possibility of discharge between the pair of electrodes 3 increases. FIG. 7 shows one static electricity countermeasure unit 2.

  The present invention solves the above-described conventional problems, and an object thereof is to provide an overvoltage protection component capable of preventing discharge between a pair of electrodes.

  In order to achieve the above object, the present invention has the following configuration.

  According to the first aspect of the present invention, the ground electrode, the first and second insulating layers formed on the upper and lower surfaces of the ground electrode, and the first and second insulating layers are formed respectively. And a first electrode and a second electrode formed so that a part of the cavity faces the ground electrode through the cavity, the first electrode being a first insulating layer The second electrode is provided on the upper surface of the second insulating layer on the lower surface of the second insulating layer. According to this configuration, since the first and second electrodes can be formed on different surfaces, the first electrode And the second electrode can be prevented from being discharged.

  The invention according to claim 2 of the present invention is such that the cavity formed in the first insulating layer and the cavity formed in the second insulating layer are not continuous. Accordingly, since it is possible to prevent a part of the ground electrode from being fixed inside the cavity, the ground electrode and the electrode do not come into contact with each other, thereby stabilizing the protection from overvoltage. The effect that it is possible to obtain is obtained.

  According to the third aspect of the present invention, in particular, the cavity is filled with a voltage-dependent resistance material, and according to this configuration, the protection function against overvoltage can be further improved. A working effect can be obtained.

  According to a fourth aspect of the present invention, in particular, in the overvoltage protection component according to the first aspect, at least a pair of internal conductors respectively connected to the first electrode and the second electrode are formed. According to the configuration, when the inductor or the capacitor is formed by the inner conductor, the overvoltage protection component, the inductor, and the capacitor can be accommodated in one component, so that the mounting area and the number of components can be reduced. It is obtained.

  As described above, the overvoltage protection component of the present invention includes the first and second insulating layers formed on the upper and lower surfaces of the ground electrode, and the cavity formed in each of the first and second insulating layers, A first electrode formed on a top surface of the first insulating layer, and a second electrode formed on the upper surface of the first insulating layer. Are provided on the lower surface of the second insulating layer, respectively, so that the first and second electrodes can be formed on different surfaces, thereby preventing discharge between the first electrode and the second electrode. It has an excellent effect that it can be prevented.

Sectional drawing of the overvoltage protection component in one embodiment of this invention An exploded perspective view of a composite electronic component using the same overvoltage protection component Perspective view of the composite electronic component Equivalent circuit diagram of the composite electronic component Sectional drawing which shows the other example of the same overvoltage protection component An exploded perspective view of a composite electronic component using a conventional overvoltage protection component Sectional drawing which shows the other example of the same overvoltage protection component

  Hereinafter, an overvoltage protection component according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of an overvoltage protection component according to an embodiment of the present invention.

  As shown in FIG. 1, the composite electronic component according to one embodiment of the present invention includes a ground electrode 11, and first and second insulating layers 12a and 12b formed on the upper and lower surfaces of the ground electrode 11. The first and second cavities 13 are formed in the first and second insulating layers 12a and 12b, respectively, and the first and second cavities 13 are formed so as to face the ground electrode 11 through the cavities 13. Second electrodes 14 and 15, wherein the first electrode 14 is provided on the upper surface of the first insulating layer 12a, and the second electrode 15 is provided on the lower surface of the second insulating layer 12b. is there.

  In the above configuration, the ground electrode 11 is formed by plating or printing a conductive material such as silver in a plate shape, and is formed on the upper surface of the second insulating layer 12b. In FIG. 1, a pair of first external electrodes (not shown) connected to the ground electrode 11 are provided in the front and back direction of the drawing.

  The first and second insulating layers 12a and 12b are each made of an insulating material such as glass ceramic, the first insulating layer 12a is the upper surface of the ground electrode 11, and the second insulating layer 12b is the ground electrode 11. It is provided on the lower surface of. In addition, a first cavity 13a that penetrates the first insulating layer 12a is formed in the center of the first insulating layer 12a, and a second insulating layer 12b is penetrated in the center of the second insulating layer 12b. The second cavity portion 13b is formed, and one cavity portion 13 is constituted by the first and second cavity portions 13a and 13b. Further, a third insulating layer 12c is provided above the first insulating layer 12a, and a fourth insulating layer 12d is provided below the second insulating layer 12b.

  The two cavities 13a and 13b provided in the first and second insulating layers 12a and 12b are formed at the same position when viewed from the top, whereby one of the ground electrodes 11 is formed inside the continuous space. It is provided so that the periphery of the part is exposed. The cavity 13 is formed by filling a through-hole with a fired extinguisher material, for example, a resin paste containing acrylic bead particles and firing the overvoltage protection component at the same time.

  In order to further improve the protection function against overvoltage, the hollow portion 13 is made of a metal powder containing at least one of silver, silver palladium, gold, and iron, a glass filler, and a material mainly composed of zinc oxide. A voltage dependent resistance material may be filled.

  The first and second electrodes 14 and 15 are formed by linearly plating or printing a conductive material such as gold, silver, or silver palladium, and the first electrode 14 is an upper surface of the first insulating layer 12a. In addition, the second electrode 15 is provided on the upper surface of the fourth insulating layer 12d (the lower surface of the second insulating layer 12b). In addition, one end of each of the first and second electrodes 14 and 15 is exposed to the cavity 13 formed in the first and second insulating layers 12a and 12b, and the first and second electrodes 14 and 15 are exposed. The other end of each is exposed from the end surfaces of the first and second insulating layers 12a and 12b. A part of the first and second electrodes 14 and 15 is opposed to the ground electrode 11 through the cavity 13. Further, the distance between the first electrode 14 and the ground electrode 11 and the distance between the second electrode 15 and the ground electrode 11 are substantially the same.

  With the above configuration, the overvoltage protection component 16 is configured. Note that a pair of second external electrodes 17a and 17b are formed at both ends of the overvoltage protection component 16, and the pair of second external electrodes 17a and 17b includes the second and first electrodes 15, respectively. 14 is connected to the other end.

  The overvoltage protection component 16 includes other electronic components provided on the mounting board, or other elements formed integrally with the overvoltage protection component 16 via the pair of second external electrodes 17a and 17b. Connected to the first electrodes 15 and 14.

  In this overvoltage protection component 16, current normally does not flow, and current flows in other electronic components and other elements. However, when a voltage higher than a certain voltage is applied, the first overvoltage protection component 16 has a first current. Overvoltage is discharged between the second electrode 14 and the ground electrode 11 and between the second electrode 15 and the ground electrode 11, and a current due to the overvoltage is caused to flow to the ground to protect the electronic device.

  Next, a description will be given of a composite electronic component using an overvoltage protection component when an inductor portion as another element is integrally formed with the overvoltage protection component.

  FIG. 2 shows a composite electronic component 19 in which the inductor portion 18 and the overvoltage protection component 16 are integrally formed. FIG. 3 shows a perspective view of the composite electronic component 19.

  As shown in FIG. 2, an overvoltage protection component 16 serving as a static electricity countermeasure unit is laminated on the upper surface of the inductor unit 18, and the inductor unit 18 is formed into a sheet shape by a magnetic material such as Cu-Ni-Zn ferrite. The plurality of magnetic layers 20 are configured and a pair of spiral inner conductors 21 a and 21 b provided on the magnetic layer 20.

  The internal conductors 21a and 21b are connected to each other by a via electrode 23 formed on the magnetic layer 20, thereby forming one inductor 22 having a function as a noise filter.

  Furthermore, both ends of the inductor 22, that is, the pair of spiral inner conductors 21a and 21b are respectively connected to the second via the pair of second external electrodes 17a and 17b provided at both ends of the composite electronic component 19. Are connected to the other ends of the first electrodes 15 and 14.

  The ground electrode 11 in the overvoltage protection component 16 is connected to a pair of first external electrodes 24 a and 24 b provided on both sides of the composite electronic component 19. The first and second external electrodes 17a, 17b, 24a, and 24b are formed by printing silver on both ends and both sides of the composite electronic component 19. Further, a nickel plating layer and a tin plating layer are provided on the surface.

  A predetermined number of dummy magnetic layers 25 are provided on the upper surface of the overvoltage protection component 16 and the lower surface of the inductor section 18. The number of the first to fourth insulating layers 12a to 12d, the magnetic layer 20, and the dummy magnetic layer 25 is not limited to the number shown in FIGS.

  With the configuration described above, a π-type composite electronic component 19 having an equivalent circuit as shown in FIG. 4 is obtained. In FIG. 4, a current normally flows through the inductor unit 18, but when a voltage higher than a certain voltage such as static electricity is applied, the overvoltage protection component 16 discharges the overvoltage, and the electrons downstream of the inductor unit 18 Protect equipment.

  Further, two inductors 22 may be formed, and the inductor unit 18 may be a common mode noise filter. In this case, since two inductors 22 are formed, it is necessary to provide two pairs of electrodes 14 and 15 and an internal conductor 21 in order to cope with this. Further, the overvoltage protection component 16 may be formed below the inductor portion 18.

  In the above description, the inductor unit 18 is a single product, but a plurality of inductor units 18 may be provided to be a multiple type.

  As described above, in the embodiment of the present invention, the first and second insulating layers 12a and 12b formed on the upper and lower surfaces of the ground electrode 11 and the first and second insulating layers 12a and 12b. And the first and second electrodes 14 and 15 formed so that a part of the cavity 13 faces the ground electrode 11 through the cavity 13, respectively. Since the electrode 14 is provided on the upper surface of the first insulating layer 12a and the second electrode 15 is provided on the lower surface of the second insulating layer 12b, the first and second electrodes 14 and 15 are provided on different surfaces. As a result, the possibility of discharge between the electrodes 14 and 15 is reduced, so that the short circuit between the electrodes 14 and 15 and the deterioration of the insulation resistance between the electrodes 14 and 15 can be prevented. It is obtained.

  Conventionally, a pair of electrodes are provided on the same surface. However, in the present invention, one of the pair of electrodes is provided on another surface that is symmetric with respect to the ground electrode. The current protection characteristics do not deteriorate.

  Since the first and second electrodes 14 and 15 are formed on different surfaces, even if the first and second electrodes 14 and 15 approach or overlap each other when viewed from above, In this case, the area of the first and second electrodes 14 and 15 can be increased, so that the discharge between the first and second electrodes 14 and 15 and the ground electrode 11 can be performed. Since the area can be increased, stable discharge characteristics can be obtained, and thus the electronic device can be reliably protected from overvoltage.

  Further, in the composite electronic component 19, at least a pair of internal conductors 21b and 21a connected to the first electrode 14 and the second electrode 15 respectively are formed on the overvoltage protection component 16, and this pair of internal conductors is formed. Since the inductor 22 is constituted by the conductors 21a and 21b, the overvoltage protection component 16 and the inductor 22 can be accommodated in one component, thereby realizing a reduction in the mounting area and the number of components.

  At this time, since the composite electronic component 19 is a π-type, two electrodes 14 and 15 are required, and if the two electrodes 14 and 15 are formed on the same surface as in the prior art, a gap between a pair of electrodes is required. However, if the two electrodes 14 and 15 are formed on different surfaces, there is no discharge between the pair of electrodes.

  Further, the composite electronic component 19 normally functions as a noise filter, and when an overvoltage due to static electricity or the like is applied, the overvoltage can be discharged by the overvoltage protection component 16. Can be reliably protected.

  In the embodiment of the present invention, the first and second cavities 13a and 13b respectively formed in the first and second insulating layers 12a and 12b are formed at the same position in a top view. As shown in FIG. 5, the first cavity 13a formed in the first insulating layer 12a and the second cavity 13b formed in the second insulating layer 12b are formed as shown in FIG. It may not be continuous. With this configuration, it is possible to prevent a part of the ground electrode 11 from being fixed inside the hollow portion 13, so that the ground electrode 11 hangs down by its own weight and the ground electrode 11 and the electrodes 14, 15 come into contact with each other. In this way, the protection from overvoltage can be stabilized. Furthermore, since the volume of the cavity 13 can be reduced, when the areas of the first and second electrodes 14 and 15 are the same, the ground electrode 11 and the electrodes 14 and 15 inside the cavity 13 It is easy to concentrate the electric field between them, so that the discharge characteristics can be stabilized.

  Further, the composite electronic component 19 in which the overvoltage protection component 16 and the inductor 22 are integrated has been described, but a capacitor may be integrated with the overvoltage protection component 16.

  At this time, at least a pair of plate-like internal conductors 21a and 21b connected to the electrodes 14 and 15 via the pair of second external electrodes 17a and 17b, respectively, are provided, and the internal conductors 21a and 21b are stacked or planarly arranged. So that it is opposite.

  The overvoltage protection component according to the present invention has an effect of preventing discharge between electrodes, and particularly protects various electronic devices such as digital devices, AV devices, and information communication terminals from overvoltage caused by static electricity or the like. Therefore, the present invention is useful when applied to an overvoltage protection component used for this purpose and a composite electronic component using the same.

DESCRIPTION OF SYMBOLS 11 Ground electrode 12a 1st insulating layer 12b 2nd insulating layer 13 Cavity part 14 1st electrode 15 2nd electrode 21 Internal conductor

Claims (4)

A ground electrode; first and second insulating layers formed on the upper and lower surfaces of the ground electrode; a cavity formed in each of the first and second insulating layers; First and second electrodes formed so as to face the ground electrode through a portion, the first electrode on the top surface of the first insulating layer, and the second electrode on the second electrode Overvoltage protection components provided on the bottom surface of the insulation layer. An overvoltage protection component in which a cavity formed in a first insulating layer and a cavity formed in a second insulating layer are not continuous. 2. The overvoltage protection component according to claim 1, wherein the cavity is filled with a voltage-dependent resistance material. 2. The overvoltage protection component according to claim 1, wherein at least a pair of internal conductors respectively connected to the first electrode and the second electrode are formed.

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