WO2012153655A1

WO2012153655A1 - Esd protection device

Info

Publication number: WO2012153655A1
Application number: PCT/JP2012/061342
Authority: WO
Inventors: 山本隼也
Original assignee: 株式会社村田製作所
Priority date: 2011-05-10
Filing date: 2012-04-27
Publication date: 2012-11-15

Abstract

An input side-surface conductor, an output side-surface conductor, and a ground side-surface conductor are disposed on the side surface of a sintered body having an I/O conductor-forming layer (21), a discharge section-forming layer (22), and an inductor layer (23) layered therein. A signal input conductor (211) which conducts to the input side-surface conductor, a signal output conductor which conducts to the output side-surface conductor, and a ground conductor (213) which conducts to the ground side-surface conductor are formed in the I/O conductor-forming layer (21). Discharge conductors (221, 222) are formed in the discharge section-forming layer (22) as discharge units that conduct to the input side-surface conductor and the ground side-surface conductor. A conductor pattern (231) that configures an inductor is formed in the inductor layer (23) and conducts to the input side-surface conductor and the output side-surface conductor. As a result, an ESD protection element capable of reliably protecting electrical components connected at a latter stage from static electricity is provided.

Description

ESD protection device

The present invention relates to an ESD protection device that protects electronic equipment from generated static electricity.

In recent years, electronic parts used in electronic devices such as mobile phones have a structure that is vulnerable to static electricity, and they are damaged by electrostatic discharge (ESD) or are affected by malfunctions. May receive. Thus, Patent Document 1 discloses a static electricity countermeasure component suitable for a high frequency circuit.

FIG. 1 is a diagram schematically showing the configuration of an anti-static component described in Patent Document 1. In FIG. The antistatic component shown in FIG. 1 is configured by laminating and integrating a varistor layer 100 and

inductor layers

110 and 120 on which conductors are formed. By electrically connecting the conductors of each layer, a varistor and an inductor connected in parallel are provided between the signal line of the device circuit and the ground, and another inductor is connected in series to the signal line of the device circuit. A circuit will be constructed.

By using a varistor and an inductor connected in parallel, an electrostatic pulse can be bypassed to the ground by the inductor, and at the same time, a high frequency component that cannot be removed by the inductor can be absorbed by the varistor. Furthermore, the inductor connected in series with the signal line suppresses the application of the high-frequency component of the electrostatic pulse to the electrical circuit of the device, and has the effect of promoting the absorption of the high-frequency component by the ground-side varistor. The voltage applied to the electric circuit can be suppressed.

JP 2004-281893 A

In the anti-static component described in Patent Document 1, the conductor pattern of each layer is connected to the conductor formed in the

inductor layers

110 and 120 by the

via conductors

130, 131, 132, and 133. 132 and 133 may be broken by the heat of surge current due to static electricity. When the

via conductors

130, 131, 132, 133 break, it becomes impossible to reliably protect the electronic components connected to the subsequent stage of the antistatic components from static electricity.

Therefore, an object of the present invention is to provide an ESD protection element that can reliably protect an electronic component connected to a subsequent stage from static electricity.

The present invention provides an ESD protection device comprising: a laminate in which a plurality of insulator base layers are laminated; and a first side conductor, a second side conductor, and a third side conductor provided on a side surface of the laminate. The laminated body includes an input / output conductor formed with a signal input conductor conducting to the first side conductor, a signal output conductor conducting to the second side conductor, and a ground conductor conducting to the third side conductor. A conductor forming layer, a discharge part forming layer in which a discharge part conducting to each of the first side conductor and the third side conductor, and an inductor pattern conducting the first side conductor and the second side conductor are configured. And an inductor layer.

In this configuration, the discharge part of the discharge part formation layer is connected to the signal input conductor and the ground conductor of the input / output conductor formation layer via the first side conductor and the third side conductor. The inductor pattern of the inductor layer is connected to the signal input conductor and the signal output conductor of the input / output conductor formation layer via the first side conductor and the second side conductor. The discharge part of the discharge part forming layer may be a varistor or a discharge gap.

Thus, when a high voltage due to static electricity is applied from the signal input conductor of the input / output conductor forming layer, discharge occurs in the discharge section, and the surge is guided to the ground side. In addition, since the inductor pattern prevents a high-frequency component of a surge flowing from the signal input conductor to the signal output conductor, it is possible to suppress static electricity from flowing to the subsequent electronic component connected to the signal output conductor. Thereby, the latter electronic component can be protected from static electricity.

In the ESD protection device according to the present invention, the discharge part of the discharge part forming layer has a first discharge conductor and a second discharge conductor facing each other with a gap therebetween, and the first discharge conductor is the first discharge conductor. It is preferable that the first side conductor is conductive and the second discharge conductor is conductive to the third side conductor.

In this configuration, since a discharge gap is provided between the signal input conductor and the ground conductor, the signal input conductor and the ground conductor are not connected during normal operation, and the signal is guided to the ground side. There will be no damage. Further, when static electricity is applied, it discharges and a surge flows from the signal input conductor to the ground conductor and does not flow to the subsequent stage, so that it is possible to protect the subsequent electronic components. Since the ESD protection device using this discharge gap is small, for example, the ESD protection device can be downsized in comparison with the case where a varistor is used.

In the ESD protection device according to the present invention, the input / output conductor formation layer, the discharge portion formation layer, and the inductor layer are preferably laminated in this order.

In this configuration, the discharge portion forming layer is laminated near the input / output conductor forming layer. When the discharge portion forming layer and the inductor layer are laminated in reverse order, an unnecessary inductance component is likely to be generated between the input conductor and the discharge portion. Since this inductance component exists in the previous stage of the discharge part, the high frequency component contained in the surge is blocked by the inductance component, the discharge start voltage of the discharge part is increased, and the discharge performance is lowered. For this reason, by stacking the discharge portion forming layer near the input / output conductor forming layer, unnecessary inductance components can be reduced, and more effective electrostatic discharge can be performed.

The ESD protection device according to the present invention includes a cavity in a portion facing each other with an interval between the first discharge conductor and the second discharge conductor at the interface between the input / output conductor formation layer and the discharge portion formation layer. May be provided.

In this configuration, air discharge can be generated to stabilize the ESD discharge characteristics.

The ESD protection device according to the present invention further includes an auxiliary electrode provided on the discharge part forming layer for connecting the first discharge conductor and the second discharge conductor, and the auxiliary electrode is coated with an insulating material-coated metal particle. Alternatively, the semiconductor particle may be composed of a dispersion of semiconductor particles.

In this configuration, since more creepage surfaces are formed, the ESD discharge characteristics can be stabilized, and the discharge characteristics can be further stabilized.

In the ESD protection device according to the present invention, the inductor pattern may be formed in a meander shape.

In this configuration, since the inductor can be configured with one insulator layer, it is not necessary to stack the insulator layer to configure the inductor, and the ESD protection device can be configured with a smaller number of interlayer connections. Further, since the first and second discharge electrodes are directly connected to the side conductors and it is not necessary to use via conductors, the reliability against surge is high.

In the ESD protection device according to the present invention, the inductor layer includes a plurality of insulator layers on which conductor patterns are formed, and the conductor pattern formed on the insulator layer is located in a via hole of the insulator layer. A multilayer inductor formed by direct interlayer connection to the conductor pattern of the insulator layer may be used.

In this configuration, conductor patterns formed in different insulator layers are directly connected to each other (bare connection). When the conductive patterns of each layer are connected to each other with via conductors, a conductive paste having a different particle size or resin component from the conductive paste used for the conductive pattern is used. Further, since the via conductor is generally formed in a separate process from the conductor pattern, the via conductor and the conductor pattern are not completely the same material, and the resistance of the connection portion varies. As a result, the discharge characteristics of the ESD protection device may fluctuate and reliability may be impaired. In the case of direct connection between conductor patterns using the bare connection, it is possible to prevent the discharge characteristics of the ESD protection device from deteriorating.

Also, when connecting the conductor patterns of each layer with via conductors, if the conductive paste that becomes the via conductor is insufficient in the step of forming the via conductor, the via conductor portion is lost and a gap is formed in the via conductor. By adopting bare connection, such a problem can be avoided.

According to the present invention, since the via conductor for connecting the conductor pattern formed in each layer becomes unnecessary by using the bare connection, the deterioration of the discharge characteristics of the ESD protection device due to the formation of the via conductor is avoided. be able to.

The figure which shows typically the structure of the static electricity countermeasure component of patent document 1 External view of ESD protection device according to Embodiment 1 Schematic plan view of each ceramic substrate constituting the sintered body Schematic plan view of each ceramic substrate constituting the sintered body Schematic plan view of each ceramic substrate constituting the sintered body Sectional view at the approximate center of the short side of each layer Diagram showing equivalent circuit of ESD protection device Diagram showing equivalent circuit of ESD protection device Schematic plan view of each ceramic substrate constituting the inductor layer Side surface sectional drawing of the inductor layer which concerns on Embodiment 2. FIG. Equivalent circuit of ESD protection device when capacitor layers are stacked Equivalent circuit of ESD protection device when capacitor layers are stacked

An ESD protection device according to an embodiment described below is used to protect an IC (Integrated Circuit) built in an electronic device such as a mobile phone from electrostatic discharge such as a surge. The ESD protection device is provided between the signal line and the ground. For example, when static electricity generated when a charged user touches an electronic device is applied to a signal line, the subsequent IC is protected by guiding a voltage due to the static electricity to the ground side.

(Embodiment 1)
FIG. 2 is an external view of the ESD protection device according to the first embodiment. The ESD protection device 1 includes a sintered body (laminated body) 2 having a substantially rectangular parallelepiped shape. The sintered body 2 is formed by laminating a plurality of plate-shaped ceramic green sheets having a conductor pattern formed on the surface in the thickness direction and then sintering. The ceramic green sheet becomes an insulator layer and constitutes the sintered body 2.

Outside the sintered body 2, an input side conductor (first side conductor) 3, an output side conductor (second side conductor) 4 and a ground side conductor (third side conductor) 5 are provided in contact with each other. It has been. The input side surface conductor 3 is provided so as to cover one side surface having a minimum area among the six surfaces of the sintered body 2 and a part of four surfaces adjacent thereto in a cap shape. The output side conductor 4 and the ground side conductor 5 are respectively provided at the corners of the side surface facing the side surface of the sintered body 2 provided with the input side conductor 3.

The input side conductor 3, the output side conductor 4, and the ground side conductor 5 are electrically connected to the conductor pattern formed on each insulating substrate constituting the sintered body 2, respectively. That is, the ESD protection device 1 according to the present embodiment is configured such that the conductor pattern formed on each ceramic substrate is directly conducted by the input side conductor 3, the output side conductor 4, and the ground side conductor 5.

For example, when a via conductor is used for connection of the conductor pattern, the via conductor and the conductor pattern are not completely the same material because the conductive paste having a different particle size or resin component is used or because the manufacturing process is different. The connection resistance between the via conductor and the conductor pattern varies. For this reason, the via conductor may be broken by electrostatic discharge, which may impair the reliability of the ESD protection device 1. The configuration in which the conductor pattern is directly conducted by the input side conductor 3, the output side conductor 4, and the ground side conductor 5 can prevent the reliability of the ESD protection device 1 from being lowered by eliminating the need for the via conductor. .

In addition, in the general process of forming via conductors, there may be defects in the via conductors, which may cause breakage during sintering of the laminated ceramic substrate. By doing so, the problem of breakage can be avoided.

3A, 3B, and 3C are schematic plan views of ceramic substrates constituting the sintered body 2. FIG. FIG. 3D is a cross-sectional view at a substantially central portion of the short side of each layer. 2, assuming that the thickness direction of the sintered body 2 is the vertical direction, FIGS. 3A, 3B, and 3C show a state seen from the lower side of the sintered body 2. 3A is an input / output conductor forming layer 21 that is the lowest layer of the sintered body 2, FIG. 3B is a discharge portion forming layer 22 that is an intermediate layer of the sintered body 2, and FIG. FIG. 3D shows a sectional view of the sintered body 2.

The input / output conductor formation layer 21 is a layer for forming an input / output of a signal to the ESD protection device 1 and a ground conductor. As shown in FIG. 3A, a rectangular signal input conductor 211, a signal output conductor 212, and a ground conductor 213 are formed on the input / output conductor formation layer 21.

The signal input conductor 211 is connected to a signal line and serves as an input terminal for inputting a signal to the ESD protection device 1. The signal input conductor 211 is formed such that one long side coincides with one short side of the input / output conductor forming layer 21. The signal input conductor 211 is electrically connected to the input side conductor 3.

The signal output conductor 212 is connected to a signal line and serves as an output terminal for outputting a signal from the ESD protection device 1. The signal output conductor 212 is formed at one corner of the short side opposite to the signal input conductor 211. The signal output conductor 212 is electrically connected to the output side conductor 4.

The ground conductor 213 serves as a terminal for connecting the ESD protection device 1 to the ground. The ground conductor 213 is formed at the other corner of the short side opposite to the signal input conductor 211. The ground conductor 213 is electrically connected to the ground side conductor 5.

The discharge part forming layer 22 is a layer in which a discharge part for discharging static electricity is formed. As shown in FIG. 3B, the

discharge conductors

221 and 222 are formed on the discharge portion forming layer 22 so as to face each other with a gap of 30 μm, for example. The discharge conductor 221 is electrically connected to the input side conductor 3 provided on the sintered body 2. Accordingly, the discharge conductor 221 is electrically connected to the signal input conductor 211 of the input / output conductor forming layer 21 through the input side conductor 3.

The discharge conductor 222 is electrically connected to the output side conductor 4 provided on the sintered body 2. Accordingly, the discharge conductor 222 is electrically connected to the ground conductor 213 of the input / output conductor forming layer 21 through the ground side conductor 5.

As shown in FIG. 3C, a conductor pattern 231 is formed in a meander shape on the inductor layer 23, and the conductor is composed of the conductor pattern 231. One end of the conductor pattern 231 is electrically connected to the input side conductor 3 and the other end is electrically connected to the output side conductor 4. Therefore, the conductor pattern 231 is electrically connected to the signal input conductor 211 and the signal output conductor 212 of the input / output conductor forming layer 21 via the input side conductor 3 and the output side conductor 4.

As shown in FIG. 3D, a cavity 224 is provided between the discharge part forming layer 22 and the input / output conductor forming layer 21. A portion of the cavity 224 that faces the gap between the first discharge conductor 221 and the second discharge conductor 222 is exposed. Since the cavity 224 is provided, air discharge can be generated to stabilize the ESD discharge characteristics.

An auxiliary electrode 223 is provided on the discharge portion forming layer 22 so as to connect the first discharge conductor 221 and the second discharge conductor 222. The auxiliary electrode 223 is made of a dispersion of insulating material-coated metal particles and semiconductor particles. With the auxiliary electrode 223, the discharge start voltage can be adjusted to an appropriate voltage. The auxiliary electrodes 223 made of the insulating material coated metal particles 225 and the semiconductor particles 226 are dispersed in the glass-like material 227, and more creepage is formed, so that the ESD discharge characteristics are stable.

Below, the manufacturing method of the sintered compact 2 is demonstrated. A BAS material mainly composed of Ba, Al and Si is mixed so as to have a predetermined composition, calcined and pulverized to obtain a ceramic powder. A ceramic green sheet is obtained by molding a slurry comprising ceramic powder, an organic solvent, a binder and a plasticizer by a doctor blade method. A conductive paste is obtained by stirring and mixing 80% by weight of Cu particles having an average particle size of 2 μm, a binder, and an organic solvent.

A metal particle is prepared by adhering Al2O3 powder having an average particle size of several nm to several tens of nm to the surface of Cu particles having an average particle size of 4 μm. The metal particles are mixed with SiC powder having an average particle diameter of 1 μm, a binder resin, and a solvent to obtain an auxiliary electrode paste.

A resin paste made of polyethylene terephthalate (PET) and an organic solvent is prepared as a burnout material for forming the cavity 224. The ceramic green sheets to be the input / output conductor forming layer 21 are laminated, and the conductive paste to be the inductor layer 23 is printed on the surface. The ceramic green sheet to be the discharge portion forming layer 22 is laminated thereon, and the auxiliary electrode forming paste to be the auxiliary electrode 223 is applied thereon.

Thereafter, the conductive paste to be the first and

second discharge conductors

221 and 222 is printed. Further, the resin paste that becomes the cavity 224 is applied. A ceramic green sheet to be the input / output conductor forming layer 21 is laminated on the upper surface, and the whole is pressure-bonded in the thickness direction. In this way, a laminate is prepared. Thereafter, the laminate is cut by pressing to obtain an ESD protection device piece.

Next, a conductive paste to be used as the input side conductor 3, the output side conductor 4, and the ground side conductor 5 is applied. Next, it is fired in a nitrogen atmosphere, and an ESD protection device is obtained in which the opposing portions of the first and

second discharge conductors

221 and 222 are exposed in a cavity formed by burning out the resin paste.

The ceramic green sheet used as the input / output conductor forming layer 21, the discharge part forming layer 22, and the input / output conductor forming layer 21 may be either a single layer or a plurality of layers.

4A and 4B are diagrams showing an equivalent circuit of the ESD protection device 1. FIG. The signal input conductor 211 of the ESD protection device 1 is connected to the signal line 10 for inputting a signal, and the signal output conductor 212 is connected to the signal line 11 for outputting a signal. The ground conductor 213 is connected to the ground.

The signal input conductor 211 is connected to the signal output conductor 212 via the input side conductor 3, the conductor pattern 231 of the inductor layer 23 constituting the inductor L, and the output side conductor 4. The signal input conductor 211 is connected to the ground conductor 213 via the input side conductor 3, the

discharge conductors

221 and 222 of the discharge portion forming layer 22, and the ground side conductor 5.

In other words, the signal input conductor 211 to which the input signal line 10 is connected is connected via the inductor L to the signal output conductor 212 to which the output signal line 11 is connected. The signal input conductor 211 is connected to the ground via the

discharge conductors

221 and 222.

In the circuit shown in FIG. 4A, even if a signal is input from the signal line 10 during normal times, the

discharge conductors

221 and 222 have a high resistance, so that the signal does not flow to the ground side through the

discharge conductors

221 and 222. Absent. In this case, a signal input from the signal line 10 flows to the signal output conductor 212 via the inductor L and is output from the signal line 11.

On the other hand, when static electricity is applied to the signal line 10 and an excessive voltage is applied to the signal line 10, a discharge occurs between the

discharge conductors

221, 222, and a surge is guided to the ground side. Further, since the inductor L does not pass the high frequency component, the high frequency component of the surge is suppressed from flowing from the signal line 10 to the signal line 11. As a result, the ESD protection device 1 prevents a voltage due to static electricity from being applied to the subsequent IC connected to the signal line 11 and protects the subsequent IC from static electricity.

As described above, in this embodiment, the IC connected to the subsequent stage of the ESD protection device 1 can be protected from static electricity. In the ESD protection device 1, the conductor patterns of the ceramic substrates constituting the sintered body 2 are conducted by the side conductors 3, 4, and 5.

Thereby, it is possible to prevent the via conductor from being broken by the high voltage of the generated static electricity and the ESD protection device 1 from functioning.

Further, in the sintered body 2, the discharge part forming layer 22 is stacked near the input / output conductor forming layer 21, but when the discharge part forming layer 22 and the inductor layer 23 are stacked in the opposite order, FIG. As shown, an unnecessary inductance component LS is easily generated between the signal input conductor 211 and the discharge conductor 221. The high frequency component is blocked by the inductance component LS, and the discharge performance by the

discharge conductors

221 and 222 is lowered. Since the ESD protection device does not discharge, static electricity flows to the subsequent stage. For this reason, by laminating the discharge part forming layer 22 near the input / output conductor forming layer 21, it is possible to eliminate the influence of the inductance component LS on the discharge of static electricity and perform more effective discharge of static electricity.

(Embodiment 2)
In the first embodiment, the inductor L of the inductor layer is configured by a linear conductor pattern formed in a meander shape. However, in the second embodiment, the inductor layer 23 is formed of a plurality of layers, and the inductor L is a multilayer inductor. This is different from the first embodiment. Only the differences will be described below.

FIG. 5 is a schematic plan view of each ceramic substrate constituting the inductor layer. FIG. 5 is a bottom view of each ceramic substrate when the inductor layer is viewed from below. FIG. 6 is a side sectional view of the inductor layer according to the second embodiment.

The inductor layer 6 is formed by laminating a first ceramic substrate 61, a second ceramic substrate 62, a third ceramic substrate 63, and a fourth ceramic substrate 64.

The first ceramic substrate 61 shown in FIG. 5A is the uppermost layer of the inductor layer, and a linear conductor pattern 611 extends from one short side of the first ceramic substrate 61 along the long side. The conductor pattern 611 is formed by being wound clockwise from the outside toward the inside center (hereinafter referred to as point A) so as to be parallel to each side of the first ceramic substrate 61.

The second ceramic substrate 62 shown in FIG. 5B is laminated below the first ceramic substrate 61. On the second ceramic substrate 62, a linear conductor pattern 621 is clocked outward from a position coincident with the point A of the first ceramic substrate 61 in the thickness direction so as to be parallel to each side of the second ceramic substrate 62. It is formed by winding in the direction. Hereinafter, the position of the outer end portion of the conductor pattern 621 is defined as B point.

The third ceramic substrate 63 shown in FIG. 5C is laminated below the second ceramic substrate 62. On the third ceramic substrate 63, a linear conductor pattern 631 is clocked inward from a position coincident with the point B of the second ceramic substrate 62 in the thickness direction so as to be parallel to each side of the third ceramic substrate 63. It is formed by winding in the direction. Hereinafter, the position of the outer end portion of the conductor pattern 631 is defined as a C point.

The fourth ceramic substrate 64 shown in FIG. 5D is laminated below the third ceramic substrate 63. On the fourth ceramic substrate 64, a linear conductor pattern 641 is clocked outward from a position coincident with the point C of the third ceramic substrate 63 in the thickness direction so as to be parallel to each side of the fourth ceramic substrate 64. It is wound in the direction and extends to one short side of the fourth ceramic substrate 64.

The conductor pattern 611 of the first ceramic substrate 61 is electrically connected to the input side conductor 3. Further, the conductor pattern 641 of the fourth ceramic substrate 64 is electrically connected to the output side conductor 4. Furthermore, the

conductor patterns

611, 621, 631, 641 of the

ceramic substrates

61, 62, 63, 64 are connected by bare connection at points A, B, and C.

In the ceramic green sheet to be each ceramic substrate, a via hole penetrating is formed by a method such as piercing by irradiating a carbon dioxide laser, and then the via hole is filled with a conductive paste simultaneously with the printing of the conductor pattern. That is, the conductive pattern and the via connection portion are formed in the same one process. An ESD protection device is manufactured by laminating a plurality of ceramic green sheets after being filled with the conductive paste, followed by pressure bonding and firing. For this reason, the variation in resistance value of the connection part of the conductor pattern between different layers is smaller than that in the case where the printing of the conductive pattern and the filling of the via hole are formed in separate processes.

Usually, via conductors that electrically connect conductor patterns between layers different from those of the ceramic substrate are formed in different processes, so even if the same conductive paste is used, they are not completely the same material. In general, a conductive paste for forming a via conductor is selected to have a good filling property, and a conductive paste for forming a conductor pattern is selected to have a good printability. For this reason, the connection between the conductor pattern and the via conductor in the ESD protection device 1 is a connection between different materials, and the resistance value of the connection portion is likely to vary. For this reason, the dispersion | variation in the discharge characteristic of the ESD protection device 1 becomes large, and there exists a possibility that the reliability with respect to the ESD protection device 1 may fall.

Therefore, as in the second embodiment, by forming the conductor pattern and the bare connection portion in the same process, the conductor pattern and the bare connection portion are made of the same material, so that the resistance value of the connection portion is substantially uniform. It is possible to prevent the reliability of the ESD protection device 1 from being lowered.

Although the ESD protection device 1 according to the present invention has been described above, the specific configuration and the like can be appropriately changed in design, and the functions and effects described in the above-described embodiments are the most preferable functions and effects resulting from the present invention. The effects are merely listed, and the operations and effects of the present invention are not limited to those described in the above-described embodiment.

For example, a capacitor layer may be further laminated on the sintered body 2 of the ESD protection device 1. 7A and 7B show an equivalent circuit of the ESD protection device 1 when capacitor layers are stacked. The capacitor layer is a ceramic substrate in which the capacitor C is constituted by a conductor pattern formed on the surface.

For example, the input / output layer, the discharge layer, the inductor layer, and the capacitor layer are stacked in this order, and one end of the conductor pattern constituting the capacitor C is connected to the output side conductor 4 and the other end is connected to the ground side conductor 5. And In this case, as shown in FIG. 7A, the inductor L in the inductor layer and the capacitor C in the capacitor layer constitute a low-pass filter.

By configuring the low-pass filter in the ESD protection device 1, the low-pass filter used in the high-frequency circuit can be incorporated in the ESD protection device 1. As a result, the area for mounting the low-pass filter element becomes unnecessary, and the circuit area can be reduced.

Further, for example, the input / output layer, the discharge layer, the capacitor layer, and the inductor layer are stacked in this order, and one end of the conductor pattern constituting the capacitor C is connected to the input side conductor 3 and the other end is connected to the output side conductor 4. In addition, one end of the inductor L is connected to the output side conductor 4 and the other end is connected to the ground side conductor 5. In this case, as shown in FIG. 7B, the inductor L in the inductor layer and the capacitor C in the capacitor layer constitute a high-pass filter.

By providing a high-pass filter, the input and output are cut off in a DC manner by the capacitor C, so that the surge energy to the circuit connected to the subsequent stage of the ESD protection device 1 can be sufficiently suppressed.

1-ESD protection device 2-sintered body (laminated body)
21-Input / output conductor forming layer 22-Discharge portion forming layer 23-Inductor layer 3-Input side conductor (first side conductor)
211—Signal input conductor 212—Signal output conductor 213—

Ground conductors

221, 222—Discharge conductor (discharge section, first discharge conductor, second discharge conductor)
223-auxiliary electrode 224-cavity 225-insulating material coated metal particle 226-semiconductor particle 227-glass-like substance 4-side conductor for output (second side conductor)
5-side conductor for ground (third side conductor)

Claims

A laminate formed by laminating a plurality of insulator base layers;
A first side conductor, a second side conductor and a third side conductor provided on the side surface of the laminate;
In an ESD protection device comprising:
The laminate is
An input / output conductor forming layer in which a signal input conductor conducting to the first side conductor, a signal output conductor conducting to the second side conductor, and a ground conductor conducting to the third side conductor;
A discharge part forming layer in which a discharge part conducting to each of the first side conductor and the third side conductor is formed;
An inductor layer in which an inductor pattern that conducts the first side conductor and the second side conductor is formed;
An ESD protection device.
The discharge part of the discharge part forming layer is
Having a first discharge conductor and a second discharge conductor facing each other at an interval;
The ESD protection device according to claim 1, wherein the first discharge conductor is electrically connected to the first side conductor, and the second discharge conductor is electrically connected to the third side conductor.
3. The ESD protection device according to claim 1, wherein the multilayer body is formed by laminating the input / output conductor formation layer, the discharge portion formation layer, and the inductor layer in this order.
The cavity is provided in the part which has mutually opposed the said 1st discharge conductor of the interface between the said input / output conductor formation layer and the said discharge part formation layer, and the 2nd discharge conductor. Or the ESD protection device according to 3.
An auxiliary electrode provided on the discharge portion forming layer for connecting the first discharge conductor and the second discharge conductor;
The ESD protection device according to any one of claims 2 to 4, wherein the auxiliary electrode is made of a dispersion of insulating material-coated metal particles and semiconductor particles.
The ESD protection device according to any one of claims 1 to 5, wherein the inductor pattern is formed in a meander shape.
The inductor layer is formed by laminating a plurality of insulator layers on which a conductor pattern is formed, and the conductor pattern formed on the insulator layer is directly on the conductor pattern of the lower insulator layer located in the via hole of the insulator layer. The ESD protection device according to any one of claims 1 to 6, wherein the ESD protection device is a multilayer inductor formed by interlayer connection.