JP2011028968A - Overvoltage protection component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an overvoltage protection component capable of reducing a possibility where a pair of terminals are conductive at a normal use state, even after using at severe conditions. <P>SOLUTION: The overvoltage protection component includes: a body 1; a first terminal 5 formed outside the body 1; a second terminal 6 formed outside the body 1; a discharge cavity part 2 formed inside the body 1; a first discharge electrode 3 electrically connected with the first terminal 5 and formed in contact with the discharge cavity part 2; a second discharge electrode 4 electrically connected with the second terminal 6 and formed in contact with the discharge cavity part 2; and an intermediate electrode 7 having a part opposite to the first discharge electrode 3 and a part opposite to the second discharge electrode 4 and formed in contact with the discharge cavity part 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an overvoltage protection component that protects electronic devices and the like from static electricity and surges.

  In recent years, downsizing and high performance of electronic devices are rapidly progressing, and accordingly, downsizing of electronic parts used in electronic devices is also progressing rapidly. However, with this miniaturization, electronic devices and electronic components are less resistant to overvoltages such as static electricity and surges, and overvoltage protection components are used as countermeasures. Overvoltage protection components are electrically connected in parallel with electronic components that are to be protected from overvoltages, and normally do not conduct electricity, but they conduct electricity when overvoltage is applied to prevent current from overvoltage from flowing to the electronic components. It is.

  As an example of such an overvoltage protection component, a pair of discharge electrodes facing each other across the cavity is formed inside the element body in which the cavity is formed, and normally no electricity flows between the pair of discharge electrodes. However, it is known that discharge occurs between a pair of discharge electrodes when an overvoltage is applied, and an electronic component is protected by flowing a current due to the overvoltage (see Patent Document 1).

Japanese Patent Laid-Open No. 7-245878

  In recent years, reliability has been demanded for overvoltage protection components under severe conditions, such as when an overvoltage higher than the normal overvoltage such as static electricity is applied, or when the number of repetitions of overvoltage is greatly increased. Has come to be.

  Under such extremely severe conditions, a phenomenon occurs in which a part of the discharge electrode is peeled off from the inner wall of the element body, and in some cases, one discharge electrode peeled off from the inner wall is in contact with the other discharge electrode. There is a fear. In such a state, a short circuit occurs between the pair of terminals, and electricity flows between the pair of terminals even in a normal use state where no overvoltage is applied, and the electronic device operates normally. It becomes impossible to do.

  The present invention solves the above-described problems of the prior art, and overvoltage protection components that reduce the possibility of conduction between a pair of terminals in a normal use state even after use under severe conditions The purpose is to provide.

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

  The invention according to claim 1 is formed in an element body, a first terminal formed outside the element body, a second terminal formed outside the element body, and the inside of the element body. The discharge cavity portion electrically connected to the first terminal, the first discharge electrode formed in contact with the discharge cavity portion, and the second terminal electrically connected, A second discharge electrode formed in contact with the discharge cavity, a portion facing the first discharge electrode, and a portion facing the second discharge electrode, and formed in contact with the discharge cavity The intermediate electrode is provided.

  According to this configuration, the first discharge electrode and the second discharge electrode are not directly opposed to each other, but the intermediate electrode has a portion facing the first discharge electrode and a portion facing the second discharge electrode. Therefore, in order for the first terminal and the second terminal to become conductive even during normal use, at least one of the electrodes peels off at the portion where the first discharge electrode and the intermediate electrode face each other. In the portion where the second discharge electrode and the intermediate electrode are in contact with each other, at least one of the electrodes needs to be peeled off and brought into contact with the other, so the possibility is very low. For this reason, even if it uses by severe conditions, it has the effect that the possibility that a 1st terminal electrode and a 2nd terminal electrode short-circuit will become very low.

  According to a second aspect of the present invention, an element body, a first terminal formed outside the element body, a second terminal formed outside the element body, and an inside of the element body are formed. The discharge cavity portion electrically connected to the first terminal, the first discharge electrode formed in contact with the discharge cavity portion, and the second terminal electrically connected, A second discharge electrode formed in contact with the discharge cavity, a portion facing the first discharge electrode, a first intermediate electrode formed in contact with the discharge cavity, It has a configuration including a second intermediate electrode formed in contact with the discharge cavity, having a portion facing the first intermediate electrode and a portion facing the second discharge electrode. .

  According to this configuration, the operating principle is the same as that of the first aspect of the invention, but in order to cause a short circuit between the first terminal and the second terminal, the first discharge electrode and the first intermediate It is necessary that contact occurs between the electrodes, and contact occurs between the second intermediate electrode and the second discharge electrode, and contact between the electrodes at three locations, not between two electrodes. The necessary effect is that the possibility of a short circuit is reduced as much as necessary.

  According to a third aspect of the present invention, an element body, a first terminal formed outside the element body, a second terminal formed outside the element body, and an inside of the element body are formed. The discharge cavity portion electrically connected to the first terminal, the first discharge electrode formed in contact with the discharge cavity portion, and the second terminal electrically connected, A second discharge electrode formed in contact with the discharge cavity, and n intermediate electrodes formed in contact with the discharge cavity, wherein the first intermediate electrode is opposed to the first discharge electrode The nth intermediate electrode has a portion facing the (n-1) th intermediate electrode and a portion facing the second discharge electrode. , The kth intermediate electrode is connected to the (k−1) th intermediate electrode and the (k + 1) th intermediate electrode. It has a portion toward (where, n is a natural number, n ≧ 3.k is a natural number, 2 ≦ k ≦ n-1.) Has a structure.

  According to this configuration, the operating principle is the same as that of the first and second aspects of the invention, but in order to cause a short circuit between the first terminal and the second terminal, 1 is added to the number of intermediate electrodes. As a result, it is necessary to cause peeling and contact of the electrode at the spot where the short circuit occurs.

  In the invention according to claim 4, in particular, an end portion of the intermediate electrode in a direction perpendicular to the direction in which the first discharge electrode and the second discharge electrode face each other is sandwiched by the element body. Accordingly, the intermediate electrode is less likely to be peeled off, so that the short-circuit between the first terminal and the second terminal is less likely to occur even when used under severe conditions.

  As described above, the overvoltage protection component of the present invention is less likely to be short-circuited according to the number of intermediate electrodes formed even when used under severe conditions, and the first terminal and the second terminal Can reduce the possibility of short circuit.

Front sectional drawing of the overvoltage protection component in Embodiment 1 of this invention Sectional view in AA of FIG. Sectional drawing which shows the manufacturing method of Embodiment 1 in this invention Sectional drawing which shows the manufacturing method of Embodiment 1 in this invention Front sectional view of the overvoltage protection component in Embodiment 2 of the present invention Front sectional view of the overvoltage protection component in Embodiment 3 of the present invention Side surface sectional drawing of the overvoltage protection component in Embodiment 4 of this invention

(Embodiment 1)
Hereinafter, the first aspect of the present invention will be described in particular, using the first embodiment.

  1 is a front sectional view of an overvoltage protection component according to Embodiment 1 of the present invention, and FIG. 2 is a sectional view taken along AA in FIG.

  1 and 2, the element body 1 is made of an insulator and has a substantially rectangular parallelepiped shape. The element body 1 is required not to be damaged even if an electric discharge occurs inside, and is preferably made of a ceramic having excellent heat resistance and thermal shock resistance. The discharge cavity 2 is formed inside the element body 1. The discharge cavity 2 has a substantially rectangular parallelepiped shape, and the inner wall (inner surface) on the bottom surface side is defined as a first plane 2a, and the inner wall on the ceiling side facing this is defined as a second plane 2b. The shape of the discharge cavity 2 is not limited to a rectangular parallelepiped shape, and may be a cubic shape or other shapes.

  The first discharge electrode 3 is provided inside the element body 1, and a part of the first discharge electrode 3 is exposed to the discharge cavity 2. The second discharge electrode 4 is also provided inside the element body 1, and a part of the second discharge electrode 4 is exposed to the discharge cavity 2. The first discharge electrode 3 and the second discharge electrode 4 are both formed on the first plane 2a, but are not physically connected.

  The first terminal 5 is formed outside the element body 1 and is electrically connected to the first discharge electrode 3. The second terminal 6 is formed outside the element body 1 and is electrically connected to the second discharge electrode 4.

  The intermediate electrode 7 is provided inside the element body 1 and is exposed to the discharge cavity 2. A part of the intermediate electrode 7 faces the first discharge electrode 3 in the thickness direction with the discharge cavity 2 interposed therebetween. Furthermore, the other part of the intermediate electrode 7 faces the second discharge electrode 4 in the thickness direction with the discharge cavity 2 interposed therebetween.

  Since the first discharge electrode 3, the second discharge electrode 4 and the intermediate electrode 7 cause a current due to the overvoltage to flow when an overvoltage is applied, it is preferable to use a material having a low specific resistance. Since discharge occurs, considering this point, it is preferable to use a material having excellent heat resistance. Therefore, a material such as silver may be used if importance is placed on a low specific resistance, and a material such as tungsten or molybdenum can be used if importance is placed on a high heat resistance.

  The manufacturing method of the first embodiment configured as described above will be described with reference to FIGS.

  3 and 4 are sectional views showing the manufacturing method according to the first embodiment of the present invention.

  First, as shown to Fig.3 (a), the 1st insulating sheet 11a which is an unbaked ceramic sheet is supplied.

  Next, as shown in FIG.3 (b), the 1st metal layer 12 and the 2nd metal layer 13 are formed on the 1st insulating sheet 11a. This formation is performed by a method of printing a paste-like substance having excellent conductivity. In the case of forming by printing, firing is usually required. However, if firing is performed simultaneously with the components formed by other printing or coating, the process can be rationalized. The first metal layer 12 and the second metal layer 13 finally become the first discharge electrode 3 and the second discharge electrode 4, respectively. In addition, the formation method of the 1st metal layer 12 and the 2nd metal layer 13 is the method of forming by thin film methods, such as sputtering, the method of forming by plating, or the metal layer formed by plating other than a printing method There is a method of transferring.

  Next, as shown in FIG. 3C, the second insulating sheet 11b, which is an unfired ceramic sheet, is formed on the first insulating sheet 11a, the first metal layer 12, and the second metal layer 13. To do. The second insulating sheet 11b has an opening at the center, and a part of the first metal layer 12 and a part of the second metal layer 13 are exposed from the opening. Yes. The second insulating sheet 11b may be formed by printing so that an opening is formed at the center instead of the unfired ceramic sheet having an opening at the center.

  Next, as shown in FIG. 3 (d), the discharge portion forming member 14 is filled into the opening located at the center of the second insulating sheet 11 b. The discharge part forming member 14 is to form the discharge cavity part 2 by evaporating in a later firing step. For example, an acrylic resin can be used, and in particular, acrylic beads are preferably used. .

  Next, as shown in FIG. 4A, the third metal layer 15 is formed on the discharge part forming member 14. The manufacturing method of the third metal layer 15 can be the same as that of the first metal layer 12 and the second metal layer 13.

  Next, as shown in FIG. 4B, a third insulating sheet 11c, which is an unfired ceramic sheet, is formed on the second insulating sheet 11b, the discharge portion forming member 14, and the third metal layer 15. .

  By performing the firing step in this state, the first insulating sheet 11a, the second insulating sheet 11b, and the third insulating sheet 11c are integrated into the element body 1. In addition, the discharge portion forming member 14 evaporates and the space that existed before firing becomes a cavity, thereby forming the discharge cavity portion 2. Further, the first metal layer 12, the second metal layer 13, and the third metal layer 15 become the first discharge electrode 3, the second discharge electrode 4, and the intermediate electrode 7, respectively, and FIG. It becomes the composition like this.

  Next, as shown in FIG. 4D, the first terminal electrode layer 16 is formed on the surface of the element body 1 where a part of the first discharge electrode 3 is exposed, and the second discharge electrode 4. A second terminal electrode layer 17 is formed on the surface where a part of the second terminal electrode layer 17 is exposed. The first terminal electrode layer 16 and the second terminal electrode layer 17 are formed by applying a conductive paste. As the conductive material of this conductive paste, for example, silver or copper can be used.

  After the first terminal electrode layer 16 and the second terminal electrode layer 17 are formed, firing is performed, and then the first terminal electrode layer 16 and the second terminal electrode layer 17 are plated with nickel by electrolytic plating. The first terminal 5 and the second terminal 6 can be formed by forming a tin plating layer thereon.

  Instead of laminating an insulating sheet or the like for each overvoltage protection component, a plurality of overvoltage protection components can be manufactured from a single large insulation sheet. In this case, as a process of dividing into individual pieces before the firing process, a large insulating sheet may be used until then.

  In addition, after the firing step, barrel polishing may be performed to round the vertices and ridgelines of the element body 1.

  The operation of the overvoltage protection component constructed and manufactured as described above will be described below.

  An overvoltage protection element is electrically connected in parallel to an electronic component or electronic circuit to be protected from overvoltage. At this time, the first terminal 5 is connected to the signal side, and the second terminal 6 is connected to the ground side. When a normal voltage is applied, the first discharge electrode 3 and the second discharge electrode 4 are electrically insulated, and the first terminal 5 and the second terminal 6 are not electrically connected. No current flows.

  On the other hand, when an overvoltage is applied between the first terminal 5 and the second terminal 6, a discharge is generated between the first discharge electrode 3 and the intermediate electrode 7 and between the intermediate electrode 7 and the second discharge electrode 4. As a result, current due to overvoltage flows between the first terminal 5 and the second terminal 6. As a result, it is possible to prevent a current caused by overvoltage from flowing to an electronic component or electronic circuit that is desired to be protected from overvoltage, so that these components or circuit can be protected.

  Here, consider the case where the overvoltage protection element is used under very severe conditions. It can be considered that the first discharge electrode 3, the second discharge electrode 4, and the intermediate electrode 7 peel from the inner wall of the element body 1 by using the overvoltage protection component under extremely severe conditions. Under such circumstances, during normal use, the first discharge electrode 3 is electrically connected between the first discharge electrode 3 and the second discharge electrode 4, that is, a short circuit occurs. And at least one of the intermediate electrode 7 peels off from the inner wall of the element body 1 and comes into contact with the other, and at least one of the intermediate electrode 7 and the second discharge electrode 4 peels off from the inner wall of the element body 1. In the case where both of them are brought into contact with each other and only contact with one of them occurs, a short circuit does not occur.

  Therefore, unlike a conventional case, when a contact occurs at one place, a short circuit does not occur. When a contact does not occur at two places, a short circuit does not occur. it can.

(Embodiment 2)
Hereinafter, the second aspect of the present invention will be described in particular with respect to the second aspect of the present invention.

  FIG. 5 is a front cross-sectional view of the overvoltage protection component according to Embodiment 2 of the present invention.

  In FIG. 5, the element body 21, the discharge cavity 22, the first plane 22a, the second plane 22b, the first discharge electrode 23, the second discharge electrode 24, the first terminal 25 and the second terminal 26 are Element body 1, discharge cavity 2, first plane 2 a, second plane 2 b, first discharge electrode 3, second discharge electrode 4, first terminal 5, and second terminal 6 in the first embodiment, respectively. It corresponds to. Unlike the first embodiment, the second discharge electrode 24 is formed on the second plane 22b.

  The first intermediate electrode 27 is formed on the second flat surface 22b, a part of which is opposed to a part of the first discharge electrode 23 with the discharge cavity portion 22 in between, and the other part is a second intermediate part. The electrode 28 is opposed to a part of the discharge cavity 22. The second intermediate electrode 28 is formed on the first flat surface 22a, and another portion different from the portion facing the first intermediate electrode 27 is a part of the second discharge electrode 24 and the discharge cavity. Opposing each other across the portion 22.

  The difference between the overvoltage protection component in the second embodiment and the overvoltage protection component in the first embodiment is that the role of the intermediate electrode 7 in the first embodiment is the two of the first intermediate electrode 27 and the second intermediate electrode 28. This is the point that the electrode bears. The manufacturing method of the overvoltage protection element in the second embodiment can be easily performed in consideration of the manufacturing method of the first embodiment. Specifically, when the first metal layer 12 is formed in the first embodiment, in the second embodiment, the metal layer that finally becomes the first discharge electrode 23 and the second intermediate electrode 28 are formed. When the metal layer is formed and the third metal layer 15 is formed in the first embodiment, the metal layer that finally becomes the first intermediate electrode 27 and the metal layer that becomes the second discharge electrode 24 are formed. That's fine.

  The operation of the overvoltage protection component according to the second embodiment of the present invention as described above is the same as the operation of the overvoltage protection component according to the first embodiment, but is short-circuited between the first terminal 25 and the second terminal 26. Occurs due to contact between the first discharge electrode 23 and the first intermediate electrode 27, and contact between the first intermediate electrode 27 and the second intermediate electrode 28, This is when contact occurs between the second intermediate electrode 28 and the second discharge electrode 24. That is, it is a condition that contact occurs at three locations, and even when compared with the overvoltage protection component of the first embodiment, the configuration is further less likely to cause a short circuit.

(Embodiment 3)
Hereinafter, the third aspect of the present invention will be described in particular with respect to the third aspect of the invention.

  FIG. 6 is a front sectional view of the overvoltage protection component according to Embodiment 3 of the present invention.

  In FIG. 6, the element body 31, the discharge cavity 32, the first plane 32a, the second plane 32b, the first discharge electrode 33, the second discharge electrode 34, the first terminal 35, and the second terminal 36 are The element body 1, the discharge cavity 2, the first plane 2a, the second plane 2b, the first discharge electrode 3, the second discharge electrode 4, the first terminal 5, and the second in the first embodiment, respectively. Corresponds to terminal 6.

  The first intermediate electrode 37 is formed on the second plane 32b, part of which is opposed to the part of the first discharge electrode 33 in the thickness direction across the discharge cavity 32, and the other part is the first part. A part of the second intermediate electrode 38 formed on the flat surface 32a is opposed to the discharge cavity 32 in the thickness direction. The second intermediate electrode 38 is different from the portion facing the first intermediate electrode 37 in the thickness direction across the third intermediate electrode 39 formed on the second plane 32b and the discharge cavity 32. Are facing each other. In the third intermediate electrode 39, a portion different from the portion facing the second intermediate electrode 38 is opposed to a part of the second discharge electrode 34 in the thickness direction with the discharge cavity 32 interposed therebetween. .

  The manufacturing method of the overvoltage protection element in the third embodiment can also be easily made by taking into account the manufacturing method in the first embodiment. It is only necessary to form a metal layer that will eventually become the second intermediate electrode 38 and the third intermediate electrode 39.

  The overvoltage protection element in the third embodiment is short-circuited between the first terminal 35 and the second terminal 36 because contact occurs between the first discharge electrode 33 and the first intermediate electrode 37. Contact occurs between the first intermediate electrode 37 and the second intermediate electrode 38, contact occurs between the second intermediate electrode 38 and the third intermediate electrode 39, and the third intermediate electrode 39 and the second discharge. This is a case where contact occurs between the electrodes 34. That is, this is a case in which contact occurs at four locations, and a configuration in which short-circuiting is less likely to occur compared to the overvoltage protection element in the second embodiment.

  The overvoltage protection element of the present invention has one intermediate electrode as shown in the first embodiment, two intermediate electrodes as shown in the second embodiment, and three intermediate electrodes as shown in the third embodiment. The present invention is not limited to one case, and can be applied to a case where there are four or more intermediate electrodes.

  When the intermediate electrodes are numbered in order from the side closer to the first discharge electrode, the odd-numbered intermediate electrodes are formed on the inner wall facing the inner wall in the element body on which the first discharge electrodes are formed. The electrode is formed on the same inner wall as the inner wall on which the first discharge electrode is formed. Further, when the number of intermediate electrodes is an odd number, the second discharge electrode is formed on the same inner wall as the first discharge electrode, and when the number of intermediate electrodes is an even number, the second discharge electrode is the first discharge electrode. Are formed on the inner wall opposite to the inner wall on which the discharge electrode is formed.

  Focusing on the kth intermediate electrode, a part of the kth intermediate electrode faces the (k-1) th intermediate electrode, and the other part of the kth intermediate electrode is the (k + 1) th. Opposite the intermediate electrode. When k = 1, that is, the first intermediate electrode faces the first discharge electrode instead of the 0th intermediate electrode, and when k = n, that is, the nth intermediate electrode is (n + 1). ) Instead of the second intermediate electrode, it faces the second discharge electrode.

  According to this configuration, in order for the second terminal to be short-circuited from the first terminal, it is a condition that contact occurs between the electrodes at the number of locations obtained by adding 1 to the number of intermediate electrodes. Therefore, as the number of intermediate electrodes is increased, a short circuit is less likely to occur.

  However, if the number of intermediate electrodes is increased, the size of the overvoltage protection component increases, and the manufacturing method tends to become slightly more complicated. Just decide.

(Embodiment 4)
Hereinafter, the fourth aspect of the present invention will be described in particular, using the fourth embodiment.

  The overvoltage protection component in Embodiment 4 has a front sectional view of FIG. 1 and a side sectional view of FIG. The difference from the overvoltage protection component in the first embodiment is the configuration of the intermediate electrode. As shown in FIG. 2, the intermediate electrode 7 of the overvoltage protection component according to the first embodiment is provided between the element body 1 and the discharge cavity 2, and there is no portion sandwiched between the element bodies 1. On the other hand, both ends of the intermediate electrode 41 of the overvoltage protection component in the fourth embodiment are sandwiched between the element bodies 1.

  Even if the overvoltage protection element is used under severe conditions, even if the intermediate electrode 41 is partially peeled from the inner wall of the element body 1, both ends thereof are sandwiched between the element bodies 1. The peeling to such an extent that it contacts with the discharge electrode 3 and the second discharge electrode 4 is difficult to occur.

  Therefore, as in the fourth embodiment, the element body 1 sandwiches both ends of the intermediate electrode 41 in the direction perpendicular to the direction in which the first discharge electrode 3 and the second discharge electrode 4 face each other. Compared with the overvoltage protection component in the first embodiment, a short circuit between the first terminal 5 and the second terminal 6 is less likely to occur. In the fourth embodiment, both ends of the intermediate electrode 41 are sandwiched between the element bodies 1, but a certain effect can be obtained even with a configuration in which only one side is sandwiched.

  Similar to the intermediate electrode 41 of the fourth embodiment, each intermediate electrode of the second and third embodiments can obtain the same effect even if the end portions thereof are sandwiched between element bodies.

  The overvoltage protection component according to the present invention has an excellent effect that it is difficult to cause a short circuit even when used under severe conditions by being applied to an electronic device or the like.

DESCRIPTION OF SYMBOLS 1 Element body 2 Discharge cavity part 2a 1st plane 2b 2nd plane 3 1st discharge electrode 4 2nd discharge electrode 5 1st terminal 6 2nd terminal 7 Intermediate electrode 11a 1st insulating sheet 11b 2nd Insulating Sheet 11c Third Insulating Sheet 12 First Metal Layer 13 Second Metal Layer 14 Discharge Part Forming Member 15 Third Metal Layer 16 First Terminal Electrode Layer 17 Second Terminal Electrode Layer 21 Element 22 Discharge Cavity 22a First plane 22b Second plane 23 First discharge electrode 24 Second discharge electrode 25 First terminal 26 Second terminal 27 First intermediate electrode 28 Second intermediate electrode 31 Element body 32 Discharge cavity Portion 32a First plane 32b Second plane 33 First discharge electrode 34 Second discharge electrode 35 First terminal 36 Second terminal 37 First intermediate electrode 38 Second intermediate electrode 39 Third intermediate electrode 41 Intermediate electrode

Claims (4)

With the body,
A first terminal formed outside the element body;
A second terminal formed outside the element body;
A discharge cavity formed inside the element;
A first discharge electrode electrically connected to the first terminal and formed in contact with the discharge cavity;
A second discharge electrode electrically connected to the second terminal and formed in contact with the discharge cavity;
An intermediate electrode having a portion facing the first discharge electrode and a portion facing the second discharge electrode and formed in contact with the discharge cavity;
Overvoltage protection component with. With the body,
A first terminal formed outside the element body;
A second terminal formed outside the element body;
A discharge cavity formed inside the element;
A first discharge electrode electrically connected to the first terminal and formed in contact with the discharge cavity;
A second discharge electrode electrically connected to the second terminal and formed in contact with the discharge cavity;
A first intermediate electrode having a portion facing the first discharge electrode and formed in contact with the discharge cavity;
A second intermediate electrode having a portion facing the first intermediate electrode and a portion facing the second discharge electrode and formed in contact with the discharge cavity;
Overvoltage protection component with. With the body,
A first terminal formed outside the element body;
A second terminal formed outside the element body;
A discharge cavity formed inside the element;
A first discharge electrode electrically connected to the first terminal and formed in contact with the discharge cavity;
A second discharge electrode electrically connected to the second terminal and formed in contact with the discharge cavity;
N intermediate electrodes formed in contact with the discharge cavity,
The first intermediate electrode has a portion facing the first discharge electrode and a portion facing the second intermediate electrode,
The nth intermediate electrode has a portion facing the (n-1) th intermediate electrode and a portion facing the second discharge electrode,
The kth intermediate electrode is an overvoltage protection component having a portion facing the (k−1) th intermediate electrode and a portion facing the (k + 1) th intermediate electrode.
(However, n is a natural number, n ≧ 3. K is a natural number, 2 ≦ k ≦ n−1.) The overvoltage protection component according to any one of claims 1 to 3, wherein an end portion of the intermediate electrode in a direction perpendicular to a direction in which the first discharge electrode and the second discharge electrode face each other is sandwiched by the element body.

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