JP3003369B2 - Voltage-dependent nonlinear resistor porcelain element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage dependency having a capacitor characteristic and a varistor characteristic used for protecting a semiconductor and a circuit of a device from abnormal high voltage, noise, static electricity, etc. generated in an electric device and an electronic device. The present invention relates to a nonlinear resistor porcelain element.

[0002]

2. Description of the Related Art Conventionally, SiC having a voltage-dependent non-linear resistance characteristic for absorbing abnormally high voltage, removing noise, eliminating sparks, and taking measures against static electricity in various electric and electronic devices.
Varistors and ZnO-based varistors are used.
The voltage-current characteristics of such a varistor can be approximately expressed by the following equation.

[0003]

(Equation 1)

Here, I is a current, V is a voltage, C is a constant unique to a varistor, and α is a voltage-current nonlinear exponent.

The α of the SiC varistor is about 2 to 7,
In some varistors, α is as high as 50. Such varistors have excellent performance in absorbing relatively high voltage, but have little effect on absorbing relatively low voltage below varistor voltage due to low dielectric constant and small inherent capacitance. And a dielectric loss tan δ of 5 to 10%
It was a big one.

On the other hand, to remove these low-voltage noises and the like, the apparent dielectric constant is about 5 × 10 ⁴ and tan δ is 1
% Of semiconductor capacitors are used. But,
When a voltage or current exceeding a certain limit is applied to such a semiconductor capacitor due to a surge or the like, the capacitance is reduced or destroyed, and the function as a capacitor is not achieved.

Therefore, recently, a device having SrTiO ₃ as a main component and having both functions of a varistor characteristic and a capacitor characteristic has been developed, and protection of semiconductor devices and circuits such as ICs and LSIs in electronic devices such as computers and electronic devices have been developed. It is used to remove noise that enters from cables and connectors that connect devices to each other.

FIG. 7 shows the structure of an element in the case where an element having both the functions of a varistor and a capacitor mainly composed of SrTiO ₃ is used for removing noise entering from a connector or the like. In FIG. 7, 1 and 2 are electrodes, and 3 is S
This is an element made of a semiconductor ceramic having rTiO ₃ as a main component and having a voltage-dependent nonlinear resistance characteristic. When such an element is incorporated in a connector, it is generally as shown in FIG. In FIG. 8, 4 is a pin, 5 and 6 are solders as conductive connection members, and 7 is a common terminal.

[0009]

However, in the above-mentioned conventional structure, as shown in FIG. 8, when the same element is incorporated in a connector, a part of the solder 5 flows into a gap between the pin 4 and the element 3 and an apparent amount of the solder 5 flows. The varistor voltage is reduced due to a decrease in the inter-electrode distance, and the varistor voltage is disadvantageously reduced in polarity and insulation resistance.

The present invention solves the above-mentioned problems, and an element having a configuration in which the varistor voltage does not change even if a part of the solder flows into the gap between the pin and the element, the varistor voltage has no polarity, and the insulation resistance does not change. It is intended to provide.

[0011]

[MEANS FOR SOLVING THE PROBLEMS] To achieve this object
The voltage-dependent nonlinear resistor ceramic element of the present invention, the main component
Is made of SrTiO ₃ and has a through hole at the center.
The convex multi-stage cylindrical shape , and the length of the large-diameter cylindrical
It formed below half the length of the body semiconductors ceramic
An element, an inner peripheral electrode provided on the entire inner peripheral surface of the through hole,
An outer peripheral electrode provided on an outer peripheral surface excluding both end surfaces of the element ,
It is arranged on a multi-stage boundary plane around the element and
Common terminal electrically connected to poles using conductive adhesive
And penetrating the through-hole, and the conductive adhesive
And a pin electrically connected to the peripheral electrode .

[0012]

According to this structure, since the inner peripheral electrode is integrated as one electrode, even if a conductive adhesive such as solder flows into a gap between the pin and the element, the inner peripheral electrode is on the integrated electrode, so that the inner peripheral electrode has an apparent appearance. The distance between the electrodes does not change. Therefore, the electrical characteristics are stable, the varistor voltage does not change, the varistor voltage has no polarity, and the insulation resistance does not change.

When the outer peripheral electrode is connected to the common terminal with a conductive adhesive such as solder, the connection is easy, the bonding strength is increased, and the excess of the conductive adhesive such as solder is removed by the multi-stage cylindrical shape. By stopping at the plane portion of the multi-stage boundary, the apparent distance between the electrodes can be kept unchanged. Also, even if the conductive adhesive such as solder drips, the apparent distance between the electrodes does not change because the conductive adhesive drips away from the outer peripheral electrode.

Further, since the outer peripheral electrode is also provided on the above-mentioned flat portion, when the common terminal is connected with a conductive adhesive or the like, the contact area becomes large, the connection is easy, and the connection can be made from two directions. The adhesive strength between the common terminal and the element can be increased, and the mechanical strength can be improved. In addition, the deterioration of characteristics due to a temperature cycle test can be reduced, and the reliability can be improved. .

By forming the innermost electrode, the outermost electrode, and the uppermost layer of the common terminal by solder plating, for example, if the gap between the pin and the innermost electrode or the gap between the outermost electrode and the common terminal is reduced, the conductive adhesive can be formed. Even without the above, the solder plating of the innermost electrode, the outermost electrode, and the uppermost layer of the common terminal can be melted and connected only by performing the heat treatment.

In order to sufficiently bring out the electrical characteristics of the device, one or more of Cu plating, Ni plating, Cr plating, Sn plating, Pb plating, Au plating, Ag plating, Pd plating, and solder plating are used. By applying a layer of plating, the electrical characteristics of the device can be fully exploited without forming a barrier at the interface between the device and the electrode, and can be easily soldered. By doing so, the solder heat resistance can be further improved.

[0017]

【Example】

Embodiment 1 Hereinafter, a first embodiment of the present invention will be described in detail.

SrCO ₃ , CaCO ₃ , BaCO ₃ , Mg
CO ₃ and TiO ₂ were weighed at various composition ratios as shown in the following (Table 1) and (Table 2), and were weighed with a ball mill or the like.
Mix for 0 hours. Next, after drying, it is fired at 1075 ° C. for 3 hours, pulverized again by a ball mill or the like for 20 hours, and dried to obtain a first component.

[0019]

[Table 1]

[0020]

[Table 2]

Next, the first component, the second component, and the third component are weighed so as to have the composition ratios shown in the above (Table 1) and (Table 2), mixed with a ball mill for 24 hours, and then dried. And an organic binder such as polyvinyl alcohol
After granulation was added wt%, at a press pressure of 1 ton / cm ^2, smaller outer diameter portion of the multi-stage cylindrical as shown in FIG. 1 is an outside diameter φ
4mm and 2.5mm in height, large outer diameter part is formed into a multi-stage cylindrical shape with outer diameter φ6mm and height 0.5mm and inner diameter of through hole φ1.4mm, and baked in air at 1150 ° C for 5 hours. Remove the binder.

Next, a reducing atmosphere, for example, N ₂ : H ₂ =
It is baked in a 9: 1 gas at 1400 ° C. for 5 hours. After that, at 4 ° C. at 1105 ° C. in an oxidizing atmosphere such as air.
Bake for hours. A conductive ohmic paste made of Zn or the like is formed on the inner peripheral surface of the through hole and the outer peripheral surface excluding both end surfaces of the sintered body thus obtained by, for example, a roller transfer method.

Thereafter, the paste is dried at 120 ° C. for 10 minutes, and a non-ohmic conductive paste is further provided thereon by a method such as roller transfer in the same manner.
It was dried for 0 minute, baked at 650 ° C. for 10 minutes to form an inner electrode and an outer electrode, and the element thus obtained is shown in FIG.

In FIG. 1, reference numeral 11 denotes an inner peripheral electrode provided on the entire inner peripheral surface of the multi-stage cylindrical through hole, 12 denotes an outer peripheral electrode provided on the entire outer peripheral surface excluding both end surfaces of the multi-stage cylindrical shape, and 13 denotes SrTiO. _This is an element made of semiconductor ceramic having voltage-dependent non-linear resistance characteristics containing ₃ as a main component, and has a cylindrical through hole formed at the center of a multi-stage cylindrical shape.

FIG. 2 shows a state in which the voltage-dependent nonlinear resistor porcelain element 13 according to the present invention is incorporated in a connector. In FIG. 2, reference numerals 14 and 15 denote conductive connecting members such as solder and conductive adhesive; 16 denotes a pin; 17 denotes a common terminal;
Indicates a case.

As described above, according to the present invention, since the inner peripheral electrode 11 formed in the multistage cylindrical through hole is integrated as one electrode, conductive adhesive such as solder is provided in the gap between the pin 16 and the element 13. Even if the agent 14 flows, the apparent distance between the electrodes does not change because it is on the integrated inner peripheral electrode 11.

Therefore, the electrical characteristics are stable, the varistor voltage does not change, the varistor voltage has no polarity, and the insulation resistance does not change. Further, by providing the outer peripheral electrode 12 on the outer peripheral surface except for both end surfaces of the multi-stage cylindrical shape, when the common terminal 17 is connected with the conductive adhesive 15 or the like, the flat portion of the stepped portion can be used, The connection area is large, the connection is easy, and the connection can be made from the upper and lower directions of the common terminal 17, so that the adhesive force between the common terminal 17 and the element 13 can be increased, and the mechanical strength can be improved. In addition, the deterioration of characteristics due to a temperature cycle test can be reduced, and the reliability can be improved.

Further, conductive adhesive 15 such as extra solder is used.
By stopping the sagging on the plane, the apparent distance between the electrodes can be kept unchanged. Even if the conductive adhesive 15 such as solder is dripped, the apparent distance between the electrodes does not change because the conductive adhesive 15 is dripped in a direction away from the outer peripheral electrode 12. In addition, by providing the above-mentioned plane portion, the surface insulation distance can be widened, the electric characteristics are stable, the varistor voltage does not change, the varistor voltage has no polarity, the insulation resistance does not change, and the element 13 Even when the connector is assembled, an effect that the change in characteristics before and after the assembly is extremely small and stable can be obtained, and the power application life characteristics can be improved and the reliability can be improved.

(Example 2) After a fired body was obtained in the same manner as in Example 1 described above, a conductive ohmic made of Zn or the like was formed on the inner peripheral surface of the through hole and the outer peripheral surface excluding both end surfaces of the sintered body. After the paste is formed by a method such as roller transfer, the paste is dried at 120 ° C. for 10 minutes and baked at 630 ° C. for 3 minutes.

Next, the conductive portion is activated with a weak acid or the like, and Cu plating-N
i-plating is performed, and electrolytic solder plating is further performed thereon to form a three-layer structure, and inner and outer electrodes 11 and 12 are formed. Next, as shown in FIG. 2, the pins 16 and the common terminals 17 are attached by conductive connecting members 14 and 15 such as solder and the like, filled with resin such as butadiene rubber, and cured by heating. The characteristics of the element 13 thus obtained were compared with those of the element 1
(Table 3) and (Table 4) show the results of assembling the three pieces and the connector.

[0031]

[Table 3]

[0032]

[Table 4]

It should be noted, V _1mA is the voltage applied across the element 13 to that which causes 1mA current, the polarity of V _1mA in a difference in the positive direction of V _1mA and the negative direction of the V _1mA in the positive direction of V _1mA The insulation resistance is the insulation resistance between the pin 16 and the common terminal 17 when the applied voltage is 12 VDC. Also,
Evaluation -20 to 85 ° C. in a temperature cycle test, indicated by the rate of change of V _1mA after 500 cycles.

As described above, in this embodiment, the innermost electrode 11 and the outermost electrode 12 and the uppermost layer of the common terminal 17 are solder-plated, so that, for example, the gap between the pin 16 and the innermost electrode 11 or the outer electrode 12 and the common terminal If the gap between the electrodes 17 and 17 is small, the inner electrode 11, the outer electrode 12, and the common terminal 17 can be formed only by heat treatment without the conductive adhesives 14 and 15.
The solder plating of the uppermost layer melts with each other to make connection.

Further, in order to sufficiently bring out the electrical characteristics of the element 13, Cu plating, Ni plating, Cr plating,
n plating, Pb plating, Au plating, Ag plating, Pd
By forming a structure in which one or a plurality of types of plating are stacked among plating and solder plating, it is possible to sufficiently bring out the electrical characteristics of the element 13 without forming a barrier at the interface between the element 13 and the electrode. Soldering can be easily performed, and solder heat resistance can be improved by using a plurality of types of multilayer plating structures. Further, by making the shape of the element 13 a multi-stage cylindrical shape, the length of the element 13 is increased,
Since the size of the element 13 in the radial direction can be reduced, the interval between the pins 16 of the connector can be reduced, and the effect of the present invention is extremely large, such as being extremely effective in reducing the size of the connector.

In the above embodiment, the first component Sr
Although only a part of the ratio of substituting with Ca, Ba, and Mg is shown, any element may be used as long as the element 13 has a varistor characteristic and a capacitor characteristic at the same time. . Furthermore, although the ratio of the A site and the B site is shown only for the equimolar, it may be rich in the A site or B site, and the ratio may be within the range having the varistor characteristic and the capacitor characteristic as the element 13 simultaneously. Anything is fine. Although the second component and the third component are shown only for some combinations in the embodiment, any component may be used as long as the component 13 has a varistor characteristic and a capacitor characteristic at the same time. . As the ohmic electrode, there are Ag, Cu, Ni, etc. other than Zn, but any other electrode may be used as long as an ohmic connection can be made at the interface between the element 13 and the electrode. . The plating method may be electrolytic or electroless, and may be acidic plating, basic plating, or neutral plating.

Further, the voltage-dependent nonlinear resistor porcelain element 13 according to the present invention is connected to an inductance composed of, for example, a ferrite, a coil, a toroidal coil, etc., so that the noise removing effect can be improved.

Embodiment 3 Hereinafter, a third embodiment of the present invention will be described in detail.

SrCO ₃ , CaCO ₃ , BaCO ₃ , Mg
CO ₃ and TiO ₂ are weighed at various composition ratios as shown in the following (Table 5), and mixed by a ball mill or the like for 24 hours. Next, after drying, it is fired at 1050 ° C. for 4 hours, crushed again by a ball mill or the like for 24 hours, and dried to obtain a first component.

[0040]

[Table 5]

[0041]

[Table 6]

Next, the first component, the second component, and the third component were weighed so as to have the composition ratios shown in the above (Table 5) and (Table 6), mixed with a ball mill or the like for 24 hours, and then dried. And an organic binder such as polyvinyl alcohol
After granulation was added wt%, at a press pressure of 1 ton / cm ^2, smaller outer diameter portion of the multi-stage cylindrical as shown in FIG. 3 is an outside diameter φ
4mm and 2.5mm in height, large outer diameter part is formed into a multi-stage cylindrical shape with outer diameter φ6mm and height 0.5mm and inner diameter of through hole φ1.4mm, and baked in air at 1200 ° C for 10 hours. Remove the binder.

Next, a reducing atmosphere, for example, N ₂ : H ₂ =
Bake at 1425 ° C. for 5 hours in 9: 1 gas. After that, at 5 ° C. at 1120 ° C. in an oxidizing atmosphere such as air.
Bake for hours. A conductive ohmic paste made of Zn or the like is applied to the inner peripheral surface of the through hole of the sintered body thus obtained and the outer peripheral surface thereof except for a certain distance from both end surfaces and the end of the large-diameter cylindrical portion, for example, by roller transfer. Respectively.

Thereafter, the paste is dried at 120 ° C. for 10 minutes, and a non-ohmic conductive paste is similarly applied thereon by a method such as roller transfer.
After drying for 0 minute and baking at 630 ° C. for 3 minutes, the inner peripheral electrode 21 and the outer peripheral electrode 22 were formed, and the element thus obtained is shown in FIG.

In FIG. 3, reference numeral 21 denotes an inner peripheral electrode provided on the entire inner peripheral surface of the multi-stage cylindrical through hole, and 22 denotes a predetermined distance from both end surfaces of the multi-stage cylindrical shape and the end of the large-diameter cylindrical portion. The outer peripheral electrode 23 provided on the entire outer peripheral surface except for Sr
This is a device made of a semiconductor ceramic having TiO ₃ as a main component and having a voltage-dependent nonlinear resistance characteristic, and has a cylindrical through hole formed at the center of a multi-stage cylindrical shape.

FIG. 4 shows a state in which the voltage-dependent nonlinear resistor ceramic element 23 according to the present invention is incorporated in a connector. In FIG. 4, reference numerals 14 and 15 denote conductive connecting members such as solder and conductive adhesive, 16 denotes a pin, 17 denotes a common terminal,
Indicates a case.

The voltage-dependent nonlinear resistor porcelain element 23 of the present invention thus configured has the same effect as that of the element 13 described in the first embodiment.
Detailed description is omitted.

(Example 4) After a fired body was obtained in the same manner as in Example 3 described above, a constant amount was set from the inner peripheral surface of the through hole, both end surfaces, and the end of the large-diameter cylindrical portion to the sintered body. An ohmic conductive paste made of Zn or the like is formed on the outer peripheral surface excluding the distance, for example, by a method such as roller transfer. After the electrodes are provided, the paste is dried at 120 ° C. for 10 minutes and baked at 630 ° C. for 3 minutes. Next, the conductive portion is activated by a weak acid or the like, and only the portion activated by electroless Cu plating-N
i-plating is performed, and further, solder plating is performed thereon by an electrolytic method to form a three-layer structure, and the inner peripheral electrode 21 and the outer peripheral electrode 22 are formed.

Next, as shown in FIG. 4, the pins 16 and the common terminals 17 are attached by conductive connecting members 14 and 15 such as solder and the like, and resin such as butadiene rubber is filled.
Heat and cure. The characteristics of the element 23 obtained in this way were obtained for the element 23 alone and after the connector was assembled (Table 7).
And (Table 8).

[0050]

[Table 7]

[0051]

[Table 8]

[0052] Incidentally, V _1mA is the voltage applied across the element 23 when the flow of 1mA current, the polarity of V _1mA in a difference in the positive direction of V _1mA and the negative direction of the V _1mA in the positive direction of V _1mA The insulation resistance is the insulation resistance between the pin 16 and the common terminal 17 when the applied voltage is 12 VDC. Also,
Evaluation -20 to 85 ° C. in a temperature cycle test, indicated by the rate of change of V _1mA after 500 cycles.

The voltage-dependent nonlinear resistor porcelain element 23 of the present invention configured as described above has the same effect as that of the element 13 described in the second embodiment.
Detailed description is omitted.

In the above embodiment, the ratio of replacing a part of Sr of the first component with Ca, Ba, and Mg is only partially shown in the embodiment. Any type may be used as long as it is within the range having the capacitor characteristics at the same time. Furthermore, A
Although the ratio between the site and the B site is shown only for an equimolar amount, the site may be rich or the B site rich, and the ratio may be any value as long as the voltage-dependent nonlinear resistance characteristic can be obtained. . Further, the second component and the third component are shown only for some combinations in the embodiment, but may be any components as long as the characteristics of the element 23 are within the range having both the varistor characteristic and the capacitor characteristic at the same time.

As the ohmic electrode, there are Ag, Cu, Ni and the like in addition to Zn, but any other electrode can be used as long as an ohmic connection can be made at the interface between the element 23 and the electrode. It doesn't matter. Although only some of the components to be plated and combinations thereof are shown, the components are not limited to these as long as similar effects can be obtained with other components and combinations. The plating method may be electrolytic or electroless, and may be acidic plating, basic plating, or neutral plating.

The voltage-dependent nonlinear resistor porcelain element 23
For example, a configuration in which an inductance formed of, for example, a ferrite, a coil, a toroidal coil, or the like is connected may be used to improve a noise removing effect.

Embodiment 5 Hereinafter, a fifth embodiment according to the present invention will be described in detail.

SrCO ₃ , CaCO ₃ , BaCO ₃ , Mg
CO ₃ and TiO ₂ are weighed at various composition ratios as shown in the following (Table 9) and mixed by a ball mill or the like for 20 hours. Next, after drying, it is fired at 1050 ° C. for 4 hours, crushed again by a ball mill or the like for 24 hours, and dried to obtain a first component.

[0059]

[Table 9]

[0060]

[Table 10]

Next, the first component, the second component, and the third component are weighed so as to have the composition ratios shown in the above (Table 9) and (Table 10), mixed for 30 hours by a ball mill or the like, and then dried. And an organic binder such as polyvinyl alcohol
After granulation was added wt%, 1ton / cm smaller outer diameter portion of the multi-stage cylindrical as shown in FIG. 5 in the ^second press pressure outer diameter φ4
2.5mm in height in mm, large outer diameter part is formed into a multi-stage cylindrical shape with an outer diameter of φ6mm and height of 0.5mm, and the inner diameter of the through hole is φ1.4mm, and fired at 1100 ° C for 6 hours in air. Remove the binder. Next, a reducing atmosphere, for example, N ₂ : H ₂ = 9:
Baking at 1375 ° C. for 4 hours in the gas of No. 1. After that, firing is performed at 1105 ° C. for 4 hours in an oxidizing atmosphere, for example, air.

The inner peripheral surface of the through hole of the sintered body thus obtained
Constant from both end faces and the end face on the side of the small diameter cylindrical section
The conductive outer surface made of Zn or the like
Mix paste by a method such as roller transfer
Provide. Then, it is dried at 120 ° C for 10 minutes,
A non-ohmic conductive paste from above
Provided by a method such as roller transfer, at 120 ° C for 10 minutes
And baked at 550 ° C. for 10 minutes.
1. The outer peripheral electrode 32 is formed, and the element thus obtained is
The child is shown in FIG. In FIG. 5, 31 is a multi-stage cylindrical penetration.
An inner peripheral electrode provided on the entire inner peripheral surface of the hole, 32 is a multi-stage cylinder
Constant from both ends of the shape and the end of the small-diameter cylinder
The outer peripheral electrode 33 provided on the entire outer peripheral surface excluding the distance is 33
SrTiO _Three-Dependent nonlinear resistance characteristics mainly composed of
Element made of semiconductor ceramic having
A cylindrical through hole is formed at the center of the cylindrical shape.

FIG. 6 shows a state in which the voltage-dependent nonlinear resistor ceramic element 33 according to the present invention is incorporated in a connector. In FIG. 6, reference numerals 14 and 15 denote conductive connecting members such as solder and conductive adhesive, 16 denotes pins, 17 denotes common terminals,
Indicates a case.

The voltage-dependent nonlinear resistor porcelain element 33 of the present invention configured as described above has the same effect as that of the element 13 described in the first embodiment.
Detailed description is omitted.

(Example 6) After a fired body was obtained in the same manner as in Example 5 described above, a constant amount was set from the inner peripheral surface of the through hole, both end surfaces, and the end of the small diameter cylindrical portion side. A conductive ohmic paste made of Zn or the like is formed on the entire outer peripheral surface except for the distance, for example, by a method such as roller transfer, and after providing electrodes, dried at 120 ° C. for 10 minutes.
Bake at ℃ for 7 minutes.

Next, the conductive portion is activated with a weak acid or the like, and Cu plating-N
i-plating, then electrolytic solder plating on it,
An inner electrode 31 and an outer electrode 32 are formed in a three-layer structure. Next, as shown in FIG. 6, the pins 16 and the common terminals 17 are attached by conductive connecting members 14 and 15 such as solder and the like, filled with a resin such as butadiene rubber, and cured by heating. The characteristics of the element 33 obtained in this way were
(Table 11) and (Table 12) show the three single products and after the assembly of the connector.

[0067]

[Table 11]

[0068]

[Table 12]

[0069] Incidentally, V _1mA is the voltage applied across the element 33 when the flow of 1mA current, the polarity of V _1mA in a difference in the positive direction of V _1mA and the negative direction of the V _1mA in the positive direction of V _1mA The insulation resistance is the insulation resistance between the pin 16 and the common terminal 17 when the applied voltage is 12 VDC. Also,
Evaluation -20 to 85 ° C. in a temperature cycle test, indicated by the rate of change of V _1mA after 500 cycles.

The voltage-dependent nonlinear resistor porcelain element 33 according to the present invention thus configured has the same effect as that of the element 13 described in the second embodiment.
Detailed description is omitted.

In the above embodiment, the ratio of replacing part of Sr of the first component with Ca, Ba, and Mg is only partially shown in the embodiment. Any type may be used as long as it is within the range having the capacitor characteristics at the same time. Furthermore, A
Although the ratio between the site and the B site is shown only for equimolar, it may be rich in the A site or rich in the B site, and the ratio may be any value as long as it has both varistor characteristics and capacitor characteristics. Further, the second component and the third component are shown only for some combinations in the embodiment, but may be any components as long as the characteristics of the element 33 are within a range having both the varistor characteristic and the capacitor characteristic at the same time.

As the ohmic electrode, there are Ag, Cu, Ni and the like in addition to Zn. Any other electrode can be used as long as an ohmic connection can be established at the interface between the element 33 and the electrode. It doesn't matter. Although only some of the components to be plated and combinations thereof are shown, the components are not limited to these as long as similar effects can be obtained with other components and combinations. The plating method may be electrolytic or electroless, and may be acidic plating, basic plating, or neutral plating. Further, it is possible to improve the noise removal effect by connecting the voltage-dependent nonlinear resistor ceramic element 33 to an inductance made of, for example, a ferrite, a coil, a toroidal coil, or the like.

[0073]

As described above, in the voltage-dependent nonlinear resistor porcelain element according to the present invention, since the inner peripheral electrode formed in the multi-stage cylindrical through hole is integrated as one electrode, the gap between the pin and the element is eliminated. Even if a conductive adhesive such as solder flows into the inner peripheral electrode, the apparent distance between the electrodes does not change because it is on the integrated inner peripheral electrode.

Therefore, the electrical characteristics are stable, the varistor voltage does not change, the varistor voltage has no polarity, and the insulation resistance does not change.

Also, a predetermined distance is removed from the entire outer peripheral surface excluding the both end surfaces of the multi-stage cylindrical shape, or from both end surfaces and either the end of the large-diameter cylindrical portion or the end of the small-diameter cylindrical portion. By providing the outer peripheral electrode on the entire outer peripheral surface, when connecting the common terminal with a conductive adhesive or the like, the flat portion of the stepped portion can be used, and the contact area increases, making the connection easy and common. Since the connection can be made from the upper and lower sides of the terminal, the adhesive force between the common terminal and the element can be increased, the mechanical strength can be improved, and the deterioration of the characteristics especially due to the temperature cycle test is reduced. And reliability can be improved.

Also, by stopping the dripping of the conductive adhesive such as extra solder at the flat portion, the apparent distance between the electrodes can be kept unchanged. Also, even if the conductive adhesive such as solder drips, the apparent distance between the electrodes does not change because the conductive adhesive drips away from the outer peripheral electrode. Also, by providing the above-mentioned plane portion,
The surface insulation distance can be widened, the electrical characteristics are stable, the varistor voltage does not change, the varistor voltage has no polarity, the insulation resistance does not change, and the characteristics change before and after assembling the element even if it is assembled into a connector Has an effect of being extremely small and stable, and can improve the charging life characteristic and the reliability.

By forming the uppermost layer of the inner and outer electrodes and the common terminal by solder plating, for example, if the gap between the pin and the inner electrode or the gap between the outer electrode and the common terminal is reduced, the conductive adhesive Even without the above, the solder plating of the innermost electrode, the outermost electrode, and the uppermost layer of the common terminal can be melted and connected only by performing the heat treatment.

Further, in order to sufficiently bring out the electrical characteristics of the element, Cu plating, Ni plating, Cr plating, Sn plating,
By forming one or more kinds of platings of plating, Pb plating, Au plating, Ag plating, Pd plating, and solder plating on top of each other, the electric power of the element can be formed without forming a barrier at the interface between the element and the electrode. Therefore, the soldering heat resistance can be improved by using a plurality of types of multi-layer plating structures. Although the length of the element is increased by making the element a multi-stage cylindrical shape, the dimension in the radial direction of the element can be reduced, so that the pin interval of the connector can be reduced, and the connector can be downsized. Many effects such as being extremely effective are obtained, and the practical effects of the present invention are extremely large.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a voltage-dependent nonlinear resistor porcelain element according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view when the same element of FIG. 1 is assembled into a connector.

FIG. 3 is a sectional view showing a voltage-dependent nonlinear resistor porcelain element according to a third embodiment of the present invention;

FIG. 4 is a cross-sectional view when the same element of FIG. 3 is assembled into a connector.

FIG. 5 is a sectional view showing a voltage-dependent nonlinear resistor porcelain element according to a fifth embodiment of the present invention;

FIG. 6 is a cross-sectional view when the same element of FIG. 5 is assembled into a connector.

FIG. 7 is a sectional view showing a conventional voltage-dependent nonlinear resistor porcelain element;

FIG. 8 is a cross-sectional view when the same element in FIG. 7 is assembled into a connector.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 inner electrode 12 outer electrode 13 element 14, 15 conductive connection member 16 pin 17 common terminal 18 case 21 inner electrode 22 outer electrode 23 element 31 inner electrode 32 outer electrode 33 element

Claims (1)

(57) [Claims] 1. A main component is a SrTiO _3, with a convex cross section of a multi-stage cylindrical having a through-hole in the center, and a large diameter to less than 1/2 length of the total length of the cylindrical portion of The formed semiconductor ceramic element and the entire inner periphery of the through hole
An inner peripheral electrode disposed, set on the outer peripheral surface except for both end surfaces of the device
Disposed on the multi-stage boundary plane of the outer periphery of the element and the outer periphery of the element
And electrically using the outer peripheral electrode and the conductive adhesive.
And a common terminal connected to the
A pin electrically connected to the inner peripheral electrode by a conductive adhesive;
A voltage-dependent nonlinear resistor porcelain element comprising: