WO2013046779A1 - Electrostatic protective component and method for manufacturing same - Google Patents

Abstract

The purpose of the present invention is to provide an electrostatic protective component and a method for manufacturing the same whereby it is possible to form at low cost a front electrode capable of withstanding electrostatic discharge tests (contact discharge tests) for 500 times or more and maintaining the electrostatic discharge suppression peak voltage below 500 V. For this purpose, an electrostatic protective component (100) is configured with front electrodes (2a, 2b) which are formed on a ceramic substrate (1) and are opposite each other via a gap (4a), glass films (21a, 21b) which are formed on the front electrodes so as to cover the upper surfaces (2a-3, 2b-3) and both side surfaces (2a-4, 2b-4) of the front electrodes and are opposite each other via a gap (4b) communicating with the gap (4a), and an electrostatic protective film (5) which has a center portion (5c) and two side portions (5a, 5b) such that the center portion (5c) is provided at the gaps (4a, 4b) and both side portions are overlapped onto the upper surfaces (21a-2, 21b-2) of the glass films, and the material of the front electrodes is a copper-nickel film or a copper-nickel-silver film.

Description

Static electricity protection component and method for manufacturing the same

The present invention relates to an electrostatic protection component and a manufacturing method thereof.

In recent years, electrostatic protection components have been used to protect electronic devices from overvoltage due to external noise and the like. The electrostatic protection component is composed of a surface electrode opposed to the gap, an electrostatic protection film provided in the gap, and the like between the line where the overvoltage may be applied in the electronic device and the ground. The electronic device is protected from the overvoltage by discharging between the surface electrodes (that is, an electrostatic protection film) when the overvoltage is applied to the line.

Such an electrostatic protection component is required to withstand a strict ESD (Electro-Static Discharge) test (contact discharge test) in order to ensure that the electrostatic protection function is reliably exhibited. In particular, for electrostatic protection components applied to in-vehicle electronic devices, etc., even if the ± 8 kV contact discharge test (see FIG. 9: detailed later) is performed 500 times or more, the ESD suppression peak voltage is 500 V or less. It is required to satisfy the condition of being maintained.

Note that tungsten films are known as conventional electrode materials (Patent Documents 1 and 2). In this case, a tungsten paste is screen-printed on a green sheet, which is a pre-firing stage of an alumina substrate, and this screen-printed tungsten paste is peaked in a firing furnace in a hydrogen (H ₂ ) -nitrogen (N ₂ ) mixed gas atmosphere. Firing is performed at a high temperature of about 1500 ° C. for 3 to 5 hours. As a result, an alumina substrate having a tungsten film electrode is completed.

JP-T-1-501465 Japanese Patent Laid-Open No. 5-267809

However, when a tungsten film is used as a surface electrode material, a tungsten paste is baked in a hydrogen-nitrogen mixed gas atmosphere at a peak temperature of 1500 ° C., so a high-temperature baking furnace is required and hydrogen, which is an explosive gas, is used. It is necessary to tighten gas management. Therefore, the manufacturing equipment becomes expensive, and if the manufacturing management is neglected, there is a possibility that it may be a life-threatening situation, so that strict manufacturing management is also required, so that the formation of the tungsten film is expensive. For this reason, the manufacturing cost of an electrostatic protection component will become high.

Therefore, in view of the above circumstances, the present invention can form a surface electrode that can withstand an ESD test (contact discharge test) of 500 times or more and maintain an ESD suppression peak voltage at 500 V or less at a low cost. It is an object to provide an electrostatic protection component and a manufacturing method thereof.

In order to solve the above problems, the inventors of the present application eagerly searched for a material for the surface electrode, and as a result, obtained the knowledge that a copper-nickel film and a copper-nickel-silver film were suitable for the surface electrode material. That is, the present invention has the following features.

The electrostatic protection component of the first invention that solves the above-mentioned problem is formed on the surface of the insulating substrate and is opposed to the surface electrode through the first gap,
An insulating film formed on the surface electrode, covering an upper surface and both side surfaces of the surface electrode, and facing each other via a second gap connected to the first gap;
An electrostatic protection film having a central part and both side parts, wherein the central part is provided in the first gap and the second gap, and the both side parts overlap an upper surface of the insulating film;
In electrostatic protection parts having
The material of the front electrode is a copper-nickel film or a copper-nickel-silver film.

The electrostatic protection component of the second invention is the electrostatic protection component of the first invention.
It has a back electrode formed on the back surface of the insulating substrate and electrically connected to the front electrode.

Moreover, the manufacturing method of the electrostatic protection component of the third invention is a method of manufacturing the electrostatic protection component of the first invention,
The surface of the insulating substrate is screen-printed with a copper-nickel paste or a copper-nickel-silver paste, and the screen-printed copper-nickel paste film or copper-nickel-silver paste film is 800 ° C. to 950 ° C. in a nitrogen atmosphere. A first step of forming a surface electrode film by firing at a peak temperature in the range of
The insulating film paste is screen-printed to cover the upper surface and both side surfaces of the surface electrode film formed in the first step, and the insulating film is formed by baking the screen-printed insulating film paste film A second step of:
A third step of cutting the surface electrode film formed in the first step and the insulating film formed in the second step to form the first gap and the second gap. When,
A shape having the central portion and the both side portions, the central portion is provided in the first gap and the second gap, and an electrostatic protection paste is screen printed so that the both side portions are overlaid on the upper surface of the insulating film. A fourth step of forming the static electricity protection film by baking the screen printed static electricity protection paste film;
It is characterized by having.

Moreover, the manufacturing method of the electrostatic protection component of the fourth invention is a method of manufacturing the electrostatic protection component of the second invention,
The surface of the insulating substrate is screen-printed with a copper-nickel paste or a copper-nickel-silver paste, and the screen-printed copper-nickel paste film or copper-nickel-silver paste film is 800 ° C. to 950 ° C. in a nitrogen atmosphere. A first step of forming a surface electrode film by firing at a peak temperature in the range of
A second step of forming the back electrode by screen-printing an electrode paste on the back surface of the insulating substrate and firing the screen-printed electrode paste film;
The insulating film paste is screen-printed so as to cover the upper surface and both side surfaces of the surface electrode film formed in the first step, and the screen-printed insulating film paste film is baked to form an insulating film. A third step;
A fourth step of cutting the surface electrode film formed in the first step and the insulating film formed in the third step to form the first gap and the second gap. When,
A shape having the central portion and the both side portions, the central portion is provided in the first gap and the second gap, and an electrostatic protection paste is screen printed so that the both side portions are overlaid on the upper surface of the insulating film. And baking the screen-printed electrostatic protection paste film to form the electrostatic protection film,
It is characterized by having.

Moreover, the manufacturing method of the static electricity protection component of 5th invention is the manufacturing method of the static electricity protection component of 4th invention,
Performing the second step after the first step;
And in the second step, firing the back electrode at a peak temperature lower than the peak temperature when firing the front electrode film in the first step,
It is characterized by.

According to a sixth aspect of the present invention, there is provided a method for manufacturing an electrostatic protection component according to any one of the third to fifth aspects of the invention.
The peak temperature when firing the surface electrode film in the first step is 900 ° C.

According to the method for manufacturing the electrostatic protection component of the first or second invention, or the electrostatic protection component of the third, fourth, fifth or sixth invention, the surface electrode is made of a copper-nickel film or copper-nickel-silver. Since it was set as the film | membrane, it can endure an ESD test (contact discharge test) 500 times or more, and can maintain an ESD suppression peak voltage at 500V or less. In addition, the copper-nickel film or the copper-nickel-silver film as the surface electrode material has a peak temperature in the range of 800 ° C. to 950 ° C. in a nitrogen atmosphere (for example, a copper-nickel paste film or a copper-nickel-silver paste film). Since it can be formed by firing at a peak temperature of 900 ° C., a high-temperature firing furnace is not necessary, and it is not necessary to strictly control the explosive gas. Therefore, since the manufacturing equipment becomes inexpensive and there is no possibility of causing a life-threatening situation by neglecting the production management, strict production management is not required, so the copper-nickel film or the copper-nickel-silver film is It can be formed at low cost. For this reason, the manufacturing cost of an electrostatic protection component can be reduced.
In addition, the three types of copper-nickel film, copper-nickel-silver film and tungsten film can withstand 500 times ESD test and satisfy the regulation of leakage current of 10 μA or less, but the copper-nickel film and copper-nickel film. -In the case of the silver film, the fluctuation of the leakage current due to the number of times of the ESD voltage application is very small compared to the case of the tungsten film, and the dielectric strength against ESD voltage application is high. Furthermore, in the case of a copper-nickel-silver film, the number of ESD voltage applications where the peak of leak current (large fluctuation) first occurs is larger than in the case of a copper-nickel film, and the dielectric strength against ESD voltage application is high. .

According to the method for manufacturing an electrostatic protection component of the fifth invention, the second step is performed after the first step, and the surface electrode film is baked in the first step in the second step. Since the back electrode is baked at a peak temperature lower than the peak temperature at that time, the back electrode can be prevented from being altered. That is, if the first step is performed after the second step, the back electrode baked in the previous second step when the surface electrode film is baked at a high peak temperature in the subsequent first step. In this case, the back electrode may be altered because it is refired at a high peak temperature. On the other hand, if the second step is performed after the first step, there is no possibility that the back electrode will be altered.
In addition, when the second step is performed after the first step, the material of the surface electrode film fired in the first step is a copper-nickel film or a copper-nickel-silver film. Even if the back electrode is baked in the air atmosphere in the second step, at this time, the appearance of the surface electrode film baked in the first step does not change significantly. Therefore, since the back electrode can be baked in an air atmosphere in the subsequent second step, it is easy to form the back electrode.

FIG. 3 is a cross-sectional view (a cross-sectional view taken along line BB in FIG. 2) showing the structure of the electrostatic protection component according to the embodiment of the present invention. It is a top view (A direction arrow view of FIG. 1) which shows the structure of the electrostatic protection component which concerns on the example of embodiment of this invention. (A) is a cross-sectional view taken along the line CC of FIG. 1, and (b) is a cross-sectional view taken along the line DD of FIG. 4 is a table showing a Cu—Ni compounding ratio (wt%) and a Cu—Ni—Ag compounding ratio (wt%) of the surface electrode material in the electrostatic protection component according to the embodiment of the present invention. It is a flowchart which shows the manufacturing process of the electrostatic protection component which concerns on the embodiment of this invention. It is 1st explanatory drawing of the manufacturing process of the electrostatic protection component which concerns on the embodiment of this invention. It is 2nd explanatory drawing of the manufacturing process of the electrostatic protection component which concerns on the embodiment of this invention. It is 3rd explanatory drawing of the manufacturing process of the electrostatic protection component which concerns on the embodiment of this invention. It is a figure explaining the method of an ESD test (contact discharge test). It is a graph which shows the measurement result of ESD suppression peak voltage. It is a graph which shows the measurement result of leakage current. FIG. 14 is a cross-sectional view (cross-sectional view taken along line FF in FIG. 13) showing another structural example (a structural example of a glass film portion) of the electrostatic protection component according to the embodiment of the present invention. It is a top view (E direction arrow view of FIG. 12) which shows the other structural example (Structural example of a glass film part) of the electrostatic protection component which concerns on the embodiment of this invention. (A) is a cross-sectional view taken along line GG in FIG. 12, and (b) is a cross-sectional view taken along line HH in FIG. FIG. 17 is a cross-sectional view (a cross-sectional view taken along the line JJ in FIG. 16) showing another structural example (a structural example of the glass film portion) of the electrostatic protection component according to the embodiment of the present invention. It is a top view (I direction view arrow view of FIG. 15) which shows the other structural example (structure example of a glass film part) of the electrostatic protection component which concerns on the embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, the structure of the electrostatic protection component according to the embodiment of the present invention will be described with reference to FIGS.

An electrostatic protection component 100 shown in FIG. 1 is a component for surface mounting on a printed circuit board such as an in-vehicle electronic device, and an electronic circuit (electronic component) mounted on the printed circuit board is subjected to overvoltage due to external noise or the like. In order to protect the electronic device, the electronic device is provided between a line to which the overvoltage may be applied and a ground.

As shown in FIGS. 1 to 3, surface electrodes 2a and 2b are formed on a surface 1a of a ceramic substrate 1 which is an insulating substrate. The surface electrodes 2a and 2b are made of a copper (Cu) -nickel (Ni) film or a copper (Cu) -nickel (Ni) -silver (Ag) film. The copper-nickel film is a composite film containing copper, nickel, and glass, and the copper-nickel-silver film is a composite film containing copper, nickel, silver, and glass. The optimum value of the film thickness of the surface electrodes 2a and 2b (copper-nickel film or copper-nickel-silver film) is 17 ± 2 μm.

As the material of the surface electrodes 2a and 2b (copper-nickel film or copper-nickel-silver film), for example, surface electrode materials A and B shown in FIG. 4 can be used. The surface electrode material A is a material of a composite film containing copper, nickel, and glass, and the surface electrode material B is a material of a composite film containing copper, nickel, silver, and glass. The Cu—Ni compounding ratio of the surface electrode material A is 62.5 wt% for Cu and 37.5 wt% for Ni. The Cu—Ni—Ag mixture ratio of the surface electrode material B is 68.2 wt% for Cu, 29.8 wt% for Ni, and 2 wt% for Ag.

The structure of the electrostatic protection component 100 will be further described. As shown in FIGS. 1 to 3, back electrodes 3a and 3b are formed on the back surface 1b of the ceramic substrate 1. The front electrodes 2a and 2b are formed over the entire length of the substrate surface 1a, while the back electrodes 3a and 3b are formed at both ends of the substrate back surface 1b.

In the central portion of the substrate surface 1a, a gap (narrow portion) 4a (first gap) is formed between the surface electrodes 2a and 2b. That is, the surface electrodes 2a and 2b are opposed to each other with the gap 4a interposed therebetween. The gap 4a is formed by cutting the surface electrode film by a cutting means such as a laser method, and has a width d of about 17 μm.

A glass film 21a which is an insulating film is formed on the front electrode 2a (near the gap), and a glass film 21b which is an insulating film is formed on the front electrode 2b (near the gap). A gap (narrow portion) 4b (second gap) is formed between the glass films 21a and 21b. That is, the glass films 21a and 21b are opposed to each other through the gap 4b. Like the gap 4a, the gap 4b has a width d of about 17 μm formed by cutting a glass film with a cutting means such as a laser method, and is continuous with the gap 4a. That is, the lower layer gap 4a and the upper layer gap 4b overlap.

The end 2a-1 on the gap side of the surface electrode 2a has its upper surface 2a-3 and both side surfaces 2a-4 and 2a-5 (that is, the portion other than the end surface 2a-6 on the gap side) covered with the glass film 21a. (See particularly FIG. 3 (a)). Similarly, the gap-side end 2b-1 of the surface electrode 2b has an upper surface 2b-3 and both side surfaces 2b-4 and 2b-5 (that is, a portion other than the gap-side end surface 2b-6) and a glass film. 21b (see in particular FIG. 3 (b)).

An electrostatic protection film 5 is formed in the gaps 4a and 4b, and the electrostatic protection film 5 and the surface electrodes 2a and 2b are connected. In addition, the end portion 2a-1 of the front electrode 2a is covered with the glass film 21a except for the end surface 2a-6 on the gap side. For this reason, the electrostatic protection film 5 is in contact with only the end face 2a-6 of the surface electrode 2a, and is not in contact with any part other than the end face 2a-6. Similarly, the end portion 2b-1 of the surface electrode 2b is covered with the glass film 21b except for the end surface 2b-6 on the gap side. For this reason, the electrostatic protection film 5 is in contact with only the end surface 2b-6 of the surface electrode 2b, and is not in contact with the portion other than the end surface 2b-6.

More specifically, the electrostatic protection film 5 has a T-shaped longitudinal cross-sectional shape (see FIG. 1), and has a central portion 5c and both side portions 5a and 5b. As described above, the central portion 5c of the electrostatic protection film 5 is provided in the gaps 4a and 4b (that is, the gaps 4a and 4b are filled to close the gaps 4a and 4b). , 5b respectively overlap the upper surfaces 21a-2, 21b-2 of the end portions 21a-1, 21b-1 on the gap side of the glass films 21a, 21b (that is, end portions 21a- inside the glass films 21a, 21b). 1 and 21b-1).

In order to minimize the decrease in insulation resistance after applying the ESD voltage, it is desirable to provide the electrostatic protection film 5 only in the gap 4a between the surface electrodes 2a and 2b. Therefore, as shown in FIG. 1 and the like, after forming the glass films 21a and 21b on the surface electrodes 2a and 2b, the method of forming the electrostatic protection film 5 by screen printing from the glass films 21a and 21b is performed. did. As a result, for the glass films 21a and 21b, not only the electrostatic protection film 5 (center part 5c) is provided in the gap 4b, but both ends 5a and 5b of the electrostatic protection film 5 are the upper surfaces of the glass films 21a and 21b. However, for the surface electrodes 2a and 2b, the glass films 21a and 21b can prevent the both end portions 5a and 5b of the electrostatic protection film 5 from overlapping the upper surfaces 2a-3 and 2b-3. The electrostatic protection film 5 (center part 5c) could be provided only on 4a. When an overvoltage due to external noise or the like is applied, the electronic device (electronic component) is protected by discharging between the end surfaces 2a-6 and 2b-6 of the surface electrodes 2a and 2b (central portion 5c of the electrostatic protection film 5). To do.

The electrostatic protection film 5 is formed using a material obtained by mixing two kinds of conductive particles and insulating particles with a silicone resin as a binder. The conductive particles and the insulating particles are not subjected to a special treatment such as providing a passive layer on the surface of the conductive particles or doping other materials on the surface of the insulating particles.

The conductive particles are aluminum (Al) powder of conductive metal particles, and the insulating particles are zinc oxide (ZnO) powder. As the zinc oxide powder, JIS standard type 1 zinc oxide, that is, zinc oxide having a volume resistivity of 200 MΩcm or more is used. Furthermore, the mixing ratio of the three components of silicone resin, aluminum powder, and zinc oxide is such that the silicone resin is 100 parts by weight, whereas the aluminum powder is 160 parts by weight, and the zinc oxide powder is 120 parts by weight. . The blending ratio of the electrostatic protection paste satisfies the target value of an ESD suppression peak voltage of 500 V or less and an ESD tolerance of 10 μA or less (insulation resistance R = 3 MΩ or more) with a standard value. The ESD suppression peak voltage is a voltage generated at the start of discharge.

Thick film upper electrodes 6a and 6b are formed on the surface electrodes 2a and 2b, respectively. Since the front electrodes 2a and 2b are also thick, the upper electrodes 6a and 6b improve the current capacity of the front electrodes 2a and 2b. However, the upper electrodes 6a and 6b are formed so as not to contact the electrostatic protection film 5 (at a position away from the electrostatic protection film 5). The reason is that when the upper electrodes 6a and 6b are in contact with the electrostatic protection film 5, when an overvoltage due to external noise or the like is applied to the electrostatic protection component 100, not between the surface electrodes 2a and 2b but the upper electrodes 6a and 6b. This is because the discharge may start between the upper electrodes 6a and 6b and the surface electrodes 2a and 2b, and in that case, the original electrostatic protection function of the electrostatic protection component cannot be exhibited. . The glass films 21a and 21b, which are insulating films, are not formed below the upper electrodes 6a and 6b.

The electrostatic protection film 5 is covered with an intermediate layer 7, and the intermediate layer 7 is covered with a protective film 8. The protective film 8 has both end portions 8a and 8b overlapping with parts of the upper electrodes 6a and 6b (portions on the gap side). The glass films 21a and 21b are not only interposed between the side portions 5a and 5b of the electrostatic protection film 5 and the surface electrodes 2a and 2b, but are also interposed between the intermediate layer 7 and the surface electrodes 2a and 2b. ing.

The protective film 8 is excellent in moisture resistance and the like, and is provided to protect the electrostatic protective film 5 and the like from an external environment such as humidity. However, since the protective film 8 has insufficient heat resistance, the electrostatic protective film 5 that generates heat during discharge is not directly covered with the protective film 8, and the intermediate protective layer 7 is excellent in heat resistance. The intermediate layer 7 is covered and covered with a protective film 8.

The intermediate layer 7 also has a function of avoiding the occurrence of abnormal discharge between the surface electrodes 2a and 2b. The intermediate layer 7 is an elastic material (elastomer) in which an appropriate amount of an inorganic filler such as silica is added to a resin material such as a silicone resin, and is discharged at the gap 4a (electrostatic protection film 5) between the surface electrodes 2a and 2b. It also has a function (buffer function) that suppresses an increase in internal energy (internal pressure) (absorbs the internal energy) and prevents damage to the electrostatic protection component 100 due to an impact due to the increase in internal energy. is doing.

End face electrodes 9a and 9b are respectively formed on both end faces 1c and 1d of the ceramic substrate 1. The end face electrodes 9a and 9b electrically connect the front electrodes 2a and 2b and the back electrodes 3a and 3b, respectively. ing. Further, the end portions 9a-1, 9a-2, 9b-1, 9b-2 of the end face electrodes 9a, 9b are connected to the end portions 2a-2, 2b-2 of the front electrodes 2a, 2b and the back electrodes 3a, 3b. Since they overlap with the end portions 3a-1 and 3b-1, respectively, the connection between the end face electrodes 9a and 9b and the front electrodes 2a and 2b and the back electrodes 3a and 3b is more reliable.

Furthermore, nickel (Ni) plating films 10a and 10b and tin (Sn) plating films 11a and 11b are formed in this order in order to improve the reliability of the terminal electrodes with respect to the end face electrodes 9a and 9b. ing. The nickel plating films 10a and 10b cover the end face electrodes 9a and 9b, the back electrodes 3a and 3b, the front electrodes 2a and 2b, and the upper electrodes 6a and 6b, respectively, and the tin plating film 11a. 11b cover the nickel plating films 10a and 10b, respectively.

Next, a method for manufacturing the electrostatic protection component 100 of the present embodiment will be described with reference to FIGS. Each manufacturing process (step) in the flowchart of FIG. 5 is denoted by reference numerals S1 to S20. 6 (a) to (d), FIG. 7 (a) to (d), and FIGS. 8 (a) to (d) sequentially show the manufacturing state of the electrostatic protection component 100 in each manufacturing process. ing. In this embodiment, a 1608 type electrostatic protection component 100 (having a width W of 0.8 mm and a length L of 1.6 mm shown in FIG. 2) was manufactured.

In the first process (step S1), as shown in FIG. 6A, the ceramic substrate 1 is received in a manufacturing process (not shown) of the electrostatic protection component 100. Here, an alumina substrate was used as the ceramic substrate 1. This alumina substrate is manufactured by using 96% alumina as a ceramic material.

6A shows only one ceramic substrate 1 in one piece region corresponding to one piece of electrostatic protection component 100, but the actual ceramic substrate before being primarily divided in step S16. Reference numeral 1 denotes a sheet shape in which a plurality of primary slits and secondary slits are formed vertically and horizontally, and a plurality of individual regions are connected vertically and horizontally.

In the next step (step S2), as shown in FIG. 6B, the surface electrode film 2 (film for forming the surface electrodes 2a and 2b in the subsequent step) is formed on the surface 1a of the ceramic substrate 1. Form. The surface electrode film 2 is formed by applying and patterning a copper-nickel paste or a copper-nickel-silver paste on the substrate surface 1a by screen printing. Copper-nickel paste is made by kneading copper powder, nickel powder, vehicle, glass powder and solvent. Copper-nickel-silver paste is made of copper powder, nickel powder, silver powder, vehicle, glass powder and solvent. Are kneaded.

For example, when the above-mentioned surface electrode material A (see FIG. 4) is used as the material of the surface electrodes 2a and 2b, the copper—Ni-containing ratio of Cu—Ni is 62.5 wt% and Ni is 37.5 wt%. Nickel paste is used. Specifically, a copper-nickel paste obtained by kneading 62.5 wt% copper powder, 37.5 wt% nickel powder, an organic material vehicle, a solvent, and glass powder is used. When the above-mentioned surface electrode material B (see FIG. 4) is used as the material of the surface electrodes 2a and 2b, a Cu—Ni—Ag compound containing 68.2 wt% Cu, 29.8 wt% Ni, and 2 wt% Ag is used. A ratio copper-nickel-silver paste is used. Specifically, copper-nickel-, which is obtained by kneading 68.2 wt% copper powder, 29.8 wt% nickel powder, 2 wt% silver powder, an organic material vehicle, a solvent, and glass powder. Use silver paste.
The copper-nickel paste and the copper-nickel-silver paste used as the materials for the surface electrodes 2a and 2b are both 100 parts by weight of metal powder (that is, in the case of copper-nickel paste, the combined weight of copper powder and nickel powder). Parts are 100 parts by weight, and in the case of copper-nickel-silver paste, the weight of the copper powder, nickel powder and silver powder is 100 parts by weight). The blending ratio is 3.5 to 15 parts by weight. The optimum values are 0.4 parts by weight of vehicle and 7 parts by weight of glass powder.

The screen printed surface electrode film 2 (copper-nickel paste film or copper-nickel-silver paste film) is dried to evaporate the solvent in the copper-nickel paste or the solvent in the copper-nickel-silver paste.

In the next step (step S3), the surface electrode film 2 (copper-nickel paste film or copper-nickel-silver paste film) formed in step S2 is subjected to a peak temperature in a firing furnace in a nitrogen (N ₂ ) atmosphere. Bake at 900 ° C. for 1 hour. The firing temperature of the surface electrode film 2 (copper-nickel paste film or copper-nickel-silver paste film) at this time is not necessarily limited to the peak temperature of 900 ° C., and the peak temperature is 800 ° C. to 950 ° C. It may be in the range of ° C.

When the surface electrode film 2 (copper-nickel paste film or copper-nickel-silver paste film) is fired, the vehicle in the copper-nickel paste or the vehicle in the copper-nickel-silver paste burns out, and the copper- The glass powder in the nickel paste or the glass powder in the copper-nickel-silver paste melts. The nitrogen atmosphere of the firing furnace contains a slight amount of oxygen (O ₂ ), and the oxygen burns out the vehicle in the copper-nickel paste or the vehicle in the copper-nickel-silver paste. In other words, a vehicle that can be burned out in a low oxygen atmosphere is used for the copper-nickel paste or the copper-nickel-silver paste. Such vehicles are generally known. The surface electrode film 2 (copper-nickel film or copper-nickel-silver film) that has been fired evaporates the solvent in the copper-nickel paste or the solvent in the copper-nickel-silver paste at the time of drying as described above. Since the vehicle burns out, it becomes a composite film of copper, nickel and glass (in the case of the surface electrode material A) or a composite film of copper, nickel, silver and glass (in the case of the surface electrode material B). The optimum value of the thickness of the fired surface electrode film 2 (copper-nickel film or copper-nickel-silver film) is 17 ± 2 μm as described above.
At this time, when the surface electrode film 2 (copper-nickel paste film or copper-nickel-silver paste film) is fired at a peak temperature lower than 800 ° C., glass powder in the copper-nickel paste or Since the glass powder in the copper-nickel-silver paste is not completely melted and becomes a porous film, the film strength of the surface electrode film 2 (copper-nickel film or copper-nickel-silver film) after firing is lowered. End up.
On the other hand, when the surface electrode film 2 (copper-nickel paste film or copper-nickel-silver paste film) is fired at a peak temperature higher than 950 ° C., glass or copper in the melted copper-nickel paste Since the glass in the nickel-silver paste spreads and the printed pattern is blurred, the thickness of the surface electrode film 2 (copper-nickel film or copper-nickel-silver film) after firing is larger than a predetermined film thickness. It will be thinner.
Accordingly, an appropriate peak temperature when firing the surface electrode film 2 (copper-nickel paste film or copper-nickel-silver paste film) is in the range of 800 ° C. to 950 ° C. as described above.

In the next step (step S4), the back electrodes 3a and 3b are formed on the back surface 1b of the ceramic substrate 1 as shown in FIG. The back electrodes 3a and 3b are formed by applying and patterning an electrode paste on the substrate back surface 1b by screen printing. Here, a silver (Ag) paste was used as the electrode paste. The screen printed back electrodes 3a and 3b (electrode paste film) are dried to evaporate the solvent in the electrode paste. As an electrode paste for forming the back electrodes 3a and 3b, a silver / palladium (Ag / Pd) paste may be used.

In the next step (step S5), as shown in FIG. 6D, a glass film 21 (a film for forming glass films 21a and 21b in a subsequent process) is formed at the center of the surface electrode film 2. . The glass film 21 is formed by applying and patterning a borosilicate glass paste, which is an insulating film paste, on the surface electrode film 2 (so as to cover the central portion of the surface electrode film 2) by screen printing. Is done.

In the next step (step S6), the back electrodes 3a and 3b (electrode paste film) formed in step 4 and the glass film 21 (borosilicate glass paste film which is an insulating film paste) formed in step S5. Are simultaneously fired at a peak temperature of 600 ° C. for 30 minutes in a firing furnace in an air (atmosphere) atmosphere. At this time, there was no significant change in the appearance of the surface electrode film 2. Therefore, it was confirmed that the back electrodes 3a and 3b and the glass film 21 can be fired in an air atmosphere.
Further, when the material of the surface electrode film 2 (that is, the surface electrodes 2a and 2b) is a copper-nickel film or a copper-nickel-silver film, an appropriate range of the Cu-Ni compound ratio or the Cu-Ni-Ag compound ratio is set. The confirmed results are as follows.
When the material of the surface electrode film 2 is a copper-nickel film in which 70% <copper content <100% and the remaining nickel content, the back electrodes 3a and 3b and the glass film 21 are formed in an air atmosphere. When baked, the surface electrode film 2 (copper-nickel film) was significantly oxidized to cause abnormal appearance, and the conductor resistance was so high that it could not be measured due to the influence of the oxide film. When the material of the surface electrode film 2 is a copper-nickel film in which 0% <copper content <50% and the rest is nickel, the surface electrode film 2 (copper-nickel film) The film strength was lowered, and the problem that the surface electrode film 2 (copper-nickel film) peeled during the production occurred. On the other hand, when the material of the surface electrode film 2 is a copper-nickel film where 50% ≦ copper content ≦ 70% and 30% ≦ nickel content ≦ 50%, Even when the electrodes 3a and 3b and the glass film 21 were baked, the surface electrode film 2 (copper-nickel film) did not change significantly in appearance or the like. Therefore, when the material of the surface electrode film 2 is a copper-nickel film, the appropriate range of the Cu—Ni mixing ratio is 50% ≦ copper content ≦ 70%, 30% ≦ nickel content ≦ 50%. It is.
If the material of the surface electrode film 2 is a copper-nickel-silver film in which 69% <copper content <98%, silver content 2%, and the remaining nickel content, air atmosphere When the back electrodes 3a and 3b and the glass film 21 are fired, the surface electrode film 2 (copper-nickel-silver film) is remarkably oxidized to cause abnormal appearance, and the conductor resistance cannot be measured due to the influence of the oxide film. It became high enough. When the material of the surface electrode film 2 is a copper-nickel-silver film in which 0% <copper content <49%, silver content 2%, and the rest is nickel content, The film strength of the film 20 (copper-nickel-silver film) was lowered, resulting in a problem that the surface electrode film 2 (copper-nickel-silver film) was peeled off during production. On the other hand, the material of the surface electrode film 2 was a copper-nickel-silver film with 49% ≦ copper content ≦ 69%, 29% ≦ nickel content ≦ 49%, and silver content 2%. In this case, even when the back electrodes 3a and 3b and the glass film 21 were fired in an air atmosphere, the surface electrode film 2 (copper-nickel-silver film) did not change significantly in appearance or the like. Therefore, when the material of the surface electrode film 2 is a copper-nickel-silver film, the appropriate range of the Cu—Ni—Ag mixture ratio is 49% ≦ copper content ≦ 69%, 29% ≦ nickel content The rate is 49% and the silver content is 2%.
In addition, the content rate of each said metal is a weight percent (wt%), and is the median value of variation.
Note that the baking of the back electrodes 3a and 3b and the glass film 21 is not necessarily limited to an air atmosphere, and may be performed in a nitrogen atmosphere.

Here, the back electrodes 3a and 3b and the front electrode film 2 are separately fired. However, the present invention is not limited to this, and the back electrodes 3a and 3b are made of a copper-nickel paste or copper as in the case of the front electrode film 2. -When formed of nickel-silver paste, the back electrodes 3a, 3b and the front electrode film 2 may be fired simultaneously in a nitrogen atmosphere.

In the next step (step S7), as shown in FIG. 7A, the central portion of the glass film 21 baked in step S6 and the baked in step S3 by a laser method using a fundamental wavelength laser (not shown). By cutting the central portion of the surface electrode film 2 simultaneously, an upper layer gap 4b and a lower layer gap 4a that are continuous (overlapped) in a row are formed simultaneously. Here, cutting was performed using a YAG laser having a fundamental wavelength (wavelength: 1064 nm). The width d of the gaps 4a and 4b was 17 μm. As a result of forming the gaps 4a and 4b, a pair of front electrodes 2a and 2b are opposed to each other via the gap 4a, and a pair of glass films 21a and 21b are opposed to each other via the gap 4b.

In the next step (step S8), as shown in FIG. 7B, a conductive paste is applied to each of the surface electrodes 2a and 2b by a screen printing method to form a pattern. Upper electrodes 6a and 6b are formed on 2b, respectively. The number of screen printings at this time is one. The upper electrodes 6 a and 6 b are formed so as to overlap the surface electrodes 2 a and 2 b at positions away from the electrostatic protection film 5 so as not to contact the electrostatic protection film 5. The upper electrodes 6a and 6b (film of conductive paste) after screen printing are dried to evaporate the solvent in the conductive paste.

The screen mesh used in this screen printing has a mesh size of 400 and an emulsion thickness of 8 ± 2 μm (product number: st400). In addition, as the conductive paste, a paste obtained by kneading silver powder and an epoxy resin was used. However, the present invention is not limited thereto, and a thick film electrode paste obtained by kneading nickel (Ni) powder, copper (Cu) powder, and the like and an epoxy resin may be used as the conductive paste for the upper electrode.

In the next step (step S9), as shown in FIG. 7C, an electrostatic protection film 5 is formed by applying an electrostatic protection paste to the gaps 4a and 4b and patterning by screen printing. Form. At this time, the electrostatic protection film 5 has a shape having a central portion 5c and both side portions 5a and 5b. For the surface electrodes 2a and 2b, the central portion 5c of the electrostatic protection film 5 is provided only in the gap 4a (filled in the gap 4a to close the gap 4a), and is connected to the surface electrodes 2a and 2b. For the films 21a and 21b, a central portion 5c of the electrostatic protection film 5 is provided in the gap 4b (filled in the gap 4b and closes the gap 4b), and both ends 5a and 5b of the electrostatic protection film 5 are made of glass. It overlaps part of the upper surfaces 21a-2 and 21b-2 (ends on the gap side) of the films 21a and 21b.

The electrostatic protective film 5 (electrostatic protective paste film) after screen printing is dried at a temperature of 100 ° C. for 10 minutes to evaporate the solvent in the electrostatic protective paste.

The screen mesh used in the screen printing of the electrostatic protection paste is a calendar mesh having a mesh size of 400, a wire diameter of 18 μm, and an emulsion thickness of 5 ± 2 μm (part number: cal400 / 18). Moreover, the paste for electrostatic protection used here uses a silicone resin binder as a basic material, and this silicone resin is kneaded with two types of powders: aluminum powder used as conductive particles and zinc oxide powder used as insulating particles. It is a thing. Furthermore, the compounding ratio of these three components was 100 parts by weight of the silicone resin, 160 parts by weight of the aluminum powder, and 120 parts by weight of the zinc oxide powder. In this case, the ESD suppression peak voltage is 500 V or less, and the ESD tolerance satisfies the target value of a leakage current of 10 μA or less (insulation resistance R = 3 MΩ or more) with a standard value.

As the silicone resin, an addition reaction type silicone resin having a volume resistivity of 2 × 10 ¹⁵ Ωcm and a dielectric constant of 2.7 was used. As the aluminum powder, aluminum powder having an average particle diameter of 3.0 to 3.6 μm obtained by melting aluminum, spraying at high pressure and solidifying by cooling was used. As the zinc oxide powder, zinc oxide having JIS standard type 1 insulation (volume resistivity of 200 MΩcm or more) was used. In addition, zinc oxide powder having a particle size distribution of 0.3 to 1.5 μm, an average particle size of 0.6 μm, and a primary aggregation particle size of 1.5 μm is applied to the zinc oxide powder. did.

In the next step (step S10), the upper electrodes 6a and 6b formed in step S8 and the electrostatic protection film 5 formed in step S9 are simultaneously baked at a temperature of 200 ° C. for 30 minutes.

In the next step (step S11), as shown in FIG. 7 (d), a silicone resin paste is applied to the electrostatic protection film 5 and the glass films 21a and 21b by a screen printing method and patterned. An intermediate layer 7 that covers the protective film 5 and the like is formed. The number of screen printings at this time is one. Here, a silicone resin paste containing 40 to 50% silica was used as the silicone resin paste. The screen mesh used in this screen printing is a calendar mesh having a mesh size of 400, a wire diameter of 18 μm, and an emulsion thickness of 5 ± 2 μm (product number: cal400 / 18).

In the next step (step S12), the intermediate layer 7 formed in step S11 is baked at a temperature of 150 ° C. for 30 minutes.

In the next step (step S13), as shown in FIG. 8A, an epoxy resin paste is applied to the intermediate layer 7, the glass films 21a and 21b, the surface electrodes 2a and 2b, and the upper electrodes 6a and 6b by screen printing. The protective film 8 which covers the intermediate | middle layer 7 etc. is formed by apply | coating and patterning. The number of screen printings at this time is 3 to 4 times. The screen mesh used in this screen printing has a mesh size of 250 and an emulsion thickness of 20 ± 2 μm (product number: St250 / 30).

In the next step (step S14), the protective film 8 formed in step S13 is baked at a temperature of 200 ° C. for 30 minutes.

In the next step (step S15), the ceramic substrate 1 is primarily divided along the primary slit formed in the sheet-like ceramic substrate 1. As a result, the ceramic substrate 1 has a strip shape in which a plurality of individual regions are arranged in a horizontal line, and end faces 1c and 1d are generated.

In the next step (step S16), as shown in FIG. 8B, the conductive paste is transferred to the end surfaces 1c and 1d of the ceramic substrate 1, a part of the front electrodes 2a and 2b, the back electrodes 3a, It is applied to a part of 3b, and this is baked for 30 minutes at a temperature of 200 ° C. in the next step (step S17), thereby forming end face electrodes 9a and 9b. At this time, the end face electrodes 9a and 9b partially overlap the front electrodes 2a and 2b and the back electrodes 3a and 3b, and electrically connect the front electrodes 2a and 2b to the back electrodes 3a and 3b. Here, a paste obtained by kneading silver powder and an epoxy resin was used as the conductive paste.

In the next step (step S18), the ceramic substrate 1 is secondarily divided along the secondary slit formed in the band-shaped ceramic substrate 1. As a result, the ceramic substrate 1 is divided into individual pieces to form individual pieces.

In the next step (step S19), as shown in FIG. 8C, end face electrodes 9a and 9b, back electrodes 3a and 3b, part of front electrodes 2a and 2b, and upper electrode are formed by barrel plating. Electroplating is performed on part of 6a and 6b to form nickel plating films 10a and 10b.

In the last step (step S20), as shown in FIG. 8D, the tin plating films 11a and 11b are electroplated on the nickel plating films 10a and 10b formed in step S19 by a barrel plating method. Form. Thus, the electrostatic protection component 100 is completed.

Next, the ESD test (contact discharge test) will be described. The ESD test was performed by applying an ESD voltage in accordance with “IEC61000-4-2 8 kV” to the sample (electrostatic protection component). In the ESD test, the electrostatic protection component 100 of the present embodiment in which the material of the surface electrodes 2a and 2b is a copper-nickel film or the copper-nickel-silver film and the static electricity of a comparative example in which the material of the surface electrode is a tungsten film. Made for protective parts. Further, regarding the electrostatic protection component 100 of the present embodiment, there are two types, one using the surface electrode material A (copper-nickel film) and one using the surface electrode material B (copper-nickel-silver film). An ESD test was conducted on the types.

The method of the ESD test (contact discharge test) will be described. As shown in FIG. 9, with the switch SW opened, a +8 kV DC voltage V ₀ is supplied from a DC power source (not shown) through a 53 MΩ resistor R ₁ . The capacitor C is charged by being applied to the capacitor C of 150 pF. Thereafter, by closing the switch SW, the capacitor C, through the resistor R ₂ of 330Ω, 50Ω ± 1% of each sample 200 which is connected in parallel to a load resistor R3 (i.e. this embodiment using the front electrode material A A discharge voltage (ESD voltage) is applied to the electrostatic protection component 100 of the embodiment, the electrostatic protection component 100 of the embodiment using the surface electrode material B, and the electrostatic protection component of a comparative example using tungsten as the surface electrode material. Apply. And the voltage V which generate | occur | produces in each sample 200 immediately after this ESD voltage is applied is measured, and it is determined whether the ESD suppression peak voltage which is the maximum value of this voltage V satisfies the regulation of 500V or less.

Further, a DC voltage of 30 V is applied to each sample 200 after the ESD voltage is applied, and a current flowing through the sample 200 at this time (referred to as a leakage current) is measured, and the leakage current is defined to be 10 μA or less. Also determine if you are satisfied.

The ESD test was performed 500 times for each sample 200. The measurement result of the ESD suppression peak voltage and the measurement result of the leak current in the 500 ESD tests are shown in FIGS. 10 and 11, ◇ indicates the ESD suppression peak voltage measurement result and leakage current measurement result when the sample 200 is the electrostatic protection component 100 using the surface electrode material A (copper-nickel film), and □ indicates the sample. Measurement results of ESD suppression peak voltage and leakage current when 200 is the electrostatic protection component 100 of this embodiment using the surface electrode material B (copper-nickel-silver film). It is the measurement result of the ESD suppression peak voltage in the case of being an electrostatic protection component using a tungsten film as a surface electrode material, and the measurement result of leakage current.

As shown in FIG. 10, 500 times of ESD is observed in any measurement results (◇, □) of the electrostatic protection component 100 using the surface electrode materials A and B (copper-nickel film, copper-nickel-silver film). Withstanding the test, the ESD suppression peak voltage satisfied the regulation of 500 V or less, and a result comparable to the measurement result (Δ) of the electrostatic protection component using tungsten as the surface electrode material was obtained.
Further, as shown in FIG. 11, in any measurement result (◇, □) of the electrostatic protection component 100 using the surface electrode materials A and B (copper-nickel film, copper-nickel-silver film), 500 times The leakage current was 10 μA or less withstanding the ESD test, and a result comparable to the measurement result (Δ) of the electrostatic protection component using the tungsten film as the surface electrode material was obtained.
In addition, the three types of surface electrode materials satisfy the regulation of a leakage current of 10 μA or less. However, when the surface electrode material is a tungsten film (Δ), the leakage current varies greatly depending on the number of ESD voltage applications. In the case of surface electrode materials A and B (copper-nickel film, copper-nickel-silver film) (◇, □), the fluctuation of leakage current due to the number of times of ESD voltage application is small, and the number of times of ESD voltage application is 10 to 60 times. Only a relatively large fluctuation in the leakage current is observed. Furthermore, in the case of the surface electrode material A (copper-nickel film) (◇), the leakage current fluctuates greatly when the ESD voltage is applied 10 to 50 times, whereas the surface electrode material B (copper-nickel film) In the case of (-silver film), the leakage current greatly fluctuates after 30 to 60 times of ESD voltage application.
That is, from the graph of the leakage current with the surface electrode material of FIG. 11 as a parameter, the case of the surface electrode materials A and B (copper-nickel film, copper-nickel-silver film) is better than the case of the tungsten film. It can be seen that the fluctuation of the leakage current due to the number of times of ESD voltage application is very small. Furthermore, from the viewpoint of the number of times of ESD voltage application at which the peak (large fluctuation) of leakage current first occurs, the surface electrode material A (copper-nickel film) and the surface electrode material B (copper-nickel-silver film) In comparison with the case of the electrode material A (copper-nickel film), in the case of the surface electrode material B (copper-nickel-silver film), when the ESD voltage is applied about 20 times more, the leakage current It can be seen that a peak has occurred.
From the above, it can be judged that the surface electrode materials A and B (copper-nickel film, copper-nickel-silver film) have a higher dielectric strength against ESD voltage application than the tungsten film. it can. It can also be determined that the surface electrode material B (copper-nickel-silver film) has a higher dielectric strength against ESD voltage application than the surface electrode material A (copper-nickel film). Therefore, the functions and effects of the present invention are also expressed from the above viewpoint.

12 to 16 show other structural examples of the electrostatic protection component according to the embodiment of the present invention. The structure of the electrostatic protection components 300 and 400 shown in FIGS. 12 to 16 is different from the structure of the electrostatic protection component 100 shown in FIGS. 1 to 3 in the structure of the glass films 21a and 21b. As for the materials of the surface electrodes 2a and 2b in the electrostatic protection components 300 and 400, a copper-nickel film or a copper-nickel-silver film is used as in the case of the surface electrodes 2a and 2b in the electrostatic protection component 100.

In the electrostatic protection component 300 shown in FIGS. 12 to 14, the glass films 21a and 21b are wider than the electrostatic protection component 100 shown in FIGS. 1 to 3 (see FIGS. 2 and 3 in particular) (see FIG. 2 to FIG. 3). In particular, see FIGS. 12 and 13: The vertical direction of FIG. 12 is the width direction of the glass films 21a and 21b).

Specifically, as shown in FIGS. 2 and 3, the glass films 21 a and 21 b in the electrostatic protection component 100 are wider than the widths of the surface electrodes 2 a and 2 b but narrower than the width of the electrostatic protection film 5. The side surfaces 2a-4, 2a-5, 2b-4, 2b-5 cover the side surfaces 2a-4, 2a-5 of the surface electrode 2a and the side surfaces 2b-4, 2b of the surface electrode 2b. It has a minimum width that can prevent contact with the electrostatic protection film 5. On the other hand, as shown in FIGS. 13 and 14, the glass films 21 a and 21 b in the electrostatic protection component 300 have the widths of the surface electrodes 2 a and 2 b, the width of the electrostatic protection film 5, and the width of the intermediate layer 7. It has a wider width than either. Other structures of the electrostatic protection component 300 are the same as those of the electrostatic protection component 100. The method for manufacturing the electrostatic protection component 300 is the same as the method for manufacturing the electrostatic protection component 100 (see FIGS. 5 to 8).

15 are the same as the cross-sectional structure shown in FIG. 3 (a) and the cross-sectional structure shown in FIG. 3 (b). Refer to As shown in FIGS. 3, 15 and 16, the electrostatic protection component 400 is longer than the electrostatic protection component 100 shown in FIGS. 1 to 3 (see FIG. 1 and FIG. 2 in particular) in the length of the glass films 21 a and 21 b. (See FIGS. 14 and 15 in particular: the horizontal direction in these drawings is the length direction of the glass films 21a and 21b).

Specifically, as shown in FIGS. 1 and 2, the glass films 21 a and 21 b in the electrostatic protection component 100 are longer than both the length of the electrostatic protection film 5 and the length of the intermediate layer 7. Yes. On the other hand, as shown in FIGS. 15 and 16, the glass films 21 a and 21 b in the electrostatic protection component 400 are longer than the length of the electrostatic protection film 5 but shorter than the length of the intermediate layer 7. It is interposed between both side portions 5a and 5b of the electrostatic protection film 5 and the surface electrodes 2a and 2b (that is, the surfaces 2a-3 and 2b-3 of the end portions 2a-1 and 2b-1 of the surface electrodes 2a and 2b are connected). It has a minimum length that can prevent both side portions 5a and 5b of the electrostatic protection film 5 from coming into contact with the surface electrodes 2a and 2b. Other structures of the electrostatic protection component 400 are the same as those of the electrostatic protection component 100. Further, the manufacturing method of the electrostatic protection component 400 is the same as the manufacturing method of the electrostatic protection component 100 (see FIGS. 5 to 8).

As described above, the electrostatic protection components 100, 300, and 400 according to the present embodiment are formed on the surface 1a of the ceramic substrate (insulating substrate) 1 and face each other through the first gap 4a. , 2b and the upper surfaces 2a-3, 2b-3 and both side surfaces 2a-4, 2b-4 of the surface electrodes 2a, 2b, which are formed on the surface electrodes 2a, 2b, and are connected to the first gap 4a. It has glass films (insulating films) 21a and 21b facing each other through the second gap 4b, a central portion 5c, and both side portions 5a and 5b, and the central portion 5c is the first gap 4a and the second gap. The material of the surface electrodes 2a and 2b is provided in the structure including the electrostatic protection film 5 provided on the upper surface 21a-2 and 21b-2 of the glass films (insulating films) 21a and 21b. However, copper-nickel film or Copper - Nickel - are characterized by a silver film.

In addition, the electrostatic protection components 100, 300, and 400 of the present embodiment include back electrodes 3a and 3b that are formed on the back surface 1b of the ceramic substrate (insulating substrate) 1 and are electrically connected to the front electrodes 2a and 2b. It is characterized by having.

Further, in the method of manufacturing the electrostatic protection component 100, 300, 400 according to the present embodiment, a copper-nickel paste or a copper-nickel-silver paste is screen-printed on the surface 1a of the ceramic substrate (insulating substrate) 1, and this screen The printed copper-nickel paste film or copper-nickel-silver paste film is baked at a peak temperature in the range of 800 ° C. to 950 ° C. (eg, 900 ° C.) in a nitrogen atmosphere to form the surface electrode film 2. The glass paste (insulating film paste) is screen-printed so as to cover the upper surface and both side surfaces of the surface electrode film 2 baked in the first process and the first process, and the screen-printed glass paste (insulating film paste) ) By firing the second film and forming the glass film (insulating film) 21 and the surface electrode formed in the first process. 2 and the third step of cutting the glass film (insulating film) 21 formed in the second step to form the first gap 4a and the second gap 4b, the central portion 5c and both sides The central portion 5c is provided in the first gap 4a and the second gap 4b, and both side portions 5a and 5b are provided on the upper surfaces 21a-2 and 21b- of the glass films (insulating films) 21a and 21b. And a fourth step of forming the electrostatic protection film 5 by screen-printing the electrostatic protection paste so as to be superimposed on layer 2 and baking the screen-printed electrostatic protection paste film.

Alternatively, in the method of manufacturing the electrostatic protection component 100, 300, 400 according to the present embodiment, a copper-nickel paste or a copper-nickel-silver paste is screen-printed on the surface 1a of the ceramic substrate (insulating substrate) 1. The screen-printed copper-nickel paste film or copper-nickel-silver paste film is baked at a peak temperature in the range of 800 ° C. to 950 ° C. (eg, 900 ° C.) in a nitrogen atmosphere to form the surface electrode film 2 A second step of forming the back electrodes 3a and 3b by screen printing an electrode paste on the back surface 1b of the ceramic substrate (insulating substrate) 1 and baking the screen-printed electrode paste film. And a glass paste (insulating film paste) so as to cover the upper surface and both side surfaces of the surface electrode film 2 baked in the step and the first step A third step of forming a glass film (insulating film) 21 by baking the screen-printed glass paste (insulating film paste) film, and the surface electrode formed in the first step A fourth step of cutting the film 2 and the glass film (insulating film) 21 formed in the third step to form a first gap 4a and a second gap 4b, a central portion 5c, It has a shape having both side portions 5a and 5b, a central portion 5c is provided in the first gap 4a and the second gap 4b, and both side portions 5a and 5b are upper surfaces 21a-2 and 21b of glass films (insulating films) 21a and 21b. And a fifth step of forming the electrostatic protection film 5 by screen-printing the electrostatic protection paste so as to be superimposed on -2 and baking the screen-printed electrostatic protection paste film. It is characterized.

Moreover, in this case, the second step is performed after the first step, and the second step is a peak when the surface electrode film 2 is baked in the first step in an air atmosphere. The back electrodes 3a and 3b are also fired at a peak temperature lower than the temperature.

Therefore, according to the electrostatic protection component 100, 300, 400 or the manufacturing method thereof according to the present embodiment, the material of the surface electrodes 2a, 2b is a copper-nickel film or a copper-nickel-silver film. Withstands an ESD test (contact discharge test), the ESD suppression peak voltage can be maintained at 500 V or less. In addition, the copper-nickel film or the copper-nickel-silver film as the surface electrode material has a peak temperature in the range of 800 ° C. to 950 ° C. in a nitrogen atmosphere (for example, a copper-nickel paste film or a copper-nickel-silver paste film). Since it can be formed by firing at a peak temperature of 900 ° C., a high-temperature firing furnace is not necessary, and it is not necessary to strictly control the explosive gas. Therefore, since the manufacturing equipment becomes inexpensive and there is no possibility of causing a life-threatening situation by neglecting the production management, strict production management is not required, so the copper-nickel film or the copper-nickel-silver film is It can be formed at low cost. For this reason, the manufacturing cost of the electrostatic protection components 100, 300, and 400 can be reduced.
In addition, the three types of copper-nickel film, copper-nickel-silver film and tungsten film can withstand 500 times ESD test and satisfy the regulation of leakage current of 10 μA or less, but the copper-nickel film and copper-nickel film. -In the case of the silver film, the fluctuation of the leakage current due to the number of times of the ESD voltage application is very small as compared with the case of the tungsten film, and the dielectric strength against the ESD voltage application is high. Furthermore, in the case of a copper-nickel-silver film, the number of ESD voltage applications where the peak of leak current (large fluctuation) first occurs is larger than in the case of a copper-nickel film, and the dielectric strength against ESD voltage application is high. .

In addition, the second step is performed after the first step, and in the second step, the peak temperature (for example, 900 ° C.) when the surface electrode film 2 is baked in the first step in an air atmosphere. Since the back electrodes 3a and 3b are also fired at a low peak temperature (600 ° C.), the back electrodes 3a and 3b can be prevented from being altered. That is, if the first step is performed after the second step, the back electrodes 3a and 3b are also formed when the front electrode film 2 is baked at a high peak temperature (for example, 900 ° C.) in the first step. Since it is refired at a high peak temperature, the back electrodes 3a and 3b may be altered. On the other hand, if the second step is performed after the first step, there is no possibility that the back electrodes 3a and 3b are altered.
Moreover, when the second step is performed after the first step, the material of the surface electrode film 2 ( surface electrodes 2a and 2b) to be baked in the first step is a copper-nickel film or a copper-nickel- Since it is a silver film, even if the back electrodes 3a and 3b are baked in an air atmosphere in the second step later, a noticeable change occurs in the appearance of the surface electrode film 2 ( front electrodes 2a and 2b) at this time. There is no. Therefore, since the back electrodes 3a and 3b can be fired in an air atmosphere, the back electrodes 3a and 3b can be easily formed.

In the above description, the embodiment of the electrostatic protection component in which one electrostatic protection film 5 is formed on one ceramic substrate 1 has been described. However, the present invention is not limited to this, and two electrostatic protection components are provided on one ceramic substrate 1. The electrostatic protection component formed with the above-described electrostatic protection film 5 is also within the scope of the present invention.

Moreover, although the above demonstrated the case where an electrostatic protective film was formed using the paste which knead | mixed three components of silicone resin, aluminum powder, and zinc oxide powder, it does not necessarily limit to this and the electrostatic protection of this invention The structure of the component can also be applied to an electrostatic protection component in which an electrostatic protection film is formed of a material having a component different from the above.

The present invention relates to an electrostatic protection component and a manufacturing method thereof, and a surface electrode capable of withstanding an ESD test (contact discharge test) of 500 times or more and maintaining an ESD suppression peak voltage at 500 V or less. It is useful when applied at low cost.

DESCRIPTION OF SYMBOLS 1 Ceramic substrate 1a Substrate surface 1b Substrate back surface 1c, 1d Substrate end surface 2 Front electrode film 2a, 2b Front electrode 2a-1, 2a-2, 2b-1, 2b-2 End portion of front electrode 2a-3, 2b-3 Front electrode upper surface 2a-4, 2a-5, 2b-4, 2b-5 Front electrode side surface 2a-6, 2b-6 Front electrode end surface 3a, 3b Back electrode 3a-1, 3b-1 End of back electrode 4a, 4b Gap 5 Electrostatic protective film 5a, 5b Side of electrostatic protective film 5c Central part of electrostatic protective film 6a, 6b Upper electrode 7 Intermediate layer 8 Protective film 8a, 8b End of protective film 9a, 9b End electrode 9a -1, 9a-2, 9b-1, 9b-2 Ends of end face electrodes 10a, 10b Nickel plating films 11a, 11b Tin plating films 21, 21a, 21b Glass films 21a-1, 21b-1 Ends of glass films 21a-2 , 21b-2 Top surface of glass film 100 Electrostatic protective component 200 Sample (electrostatic protective component)
300,400 ESD protection parts

Claims (6)

1. A surface electrode formed on the surface of the insulating substrate and facing through the first gap;
   An insulating film formed on the surface electrode, covering an upper surface and both side surfaces of the surface electrode, and facing each other via a second gap connected to the first gap;
   An electrostatic protection film having a central part and both side parts, wherein the central part is provided in the first gap and the second gap, and the both side parts overlap an upper surface of the insulating film;
   In electrostatic protection parts having
   An electrostatic protection component wherein the material of the surface electrode is a copper-nickel film or a copper-nickel-silver film.
2. In the electrostatic protection component according to claim 1,
   An electrostatic protection component comprising a back electrode formed on the back surface of the insulating substrate and electrically connected to the front electrode.
3. A method of manufacturing the electrostatic protection component according to claim 1,
   The surface of the insulating substrate is screen-printed with a copper-nickel paste or a copper-nickel-silver paste, and the screen-printed copper-nickel paste film or copper-nickel-silver paste film is 800 ° C. to 950 ° C. in a nitrogen atmosphere. A first step of forming a surface electrode film by firing at a peak temperature in the range of
   The insulating film paste is screen-printed to cover the upper surface and both side surfaces of the surface electrode film formed in the first step, and the insulating film is formed by baking the screen-printed insulating film paste film A second step of:
   A third step of cutting the surface electrode film formed in the first step and the insulating film formed in the second step to form the first gap and the second gap. When,
   A shape having the central portion and the both side portions, the central portion is provided in the first gap and the second gap, and an electrostatic protection paste is screen printed so that the both side portions are overlaid on the upper surface of the insulating film. A fourth step of forming the static electricity protection film by baking the screen printed static electricity protection paste film;
   A method for producing an electrostatic protection component, comprising:
4. A method of manufacturing the electrostatic protection component according to claim 2,
   The surface of the insulating substrate is screen-printed with a copper-nickel paste or a copper-nickel-silver paste, and the screen-printed copper-nickel paste film or copper-nickel-silver paste film is 800 ° C. to 950 ° C. in a nitrogen atmosphere. A first step of forming a surface electrode film by firing at a peak temperature in the range of
   A second step of forming the back electrode by screen-printing an electrode paste on the back surface of the insulating substrate and firing the screen-printed electrode paste film;
   The insulating film paste is screen-printed so as to cover the upper surface and both side surfaces of the surface electrode film formed in the first step, and the screen-printed insulating film paste film is baked to form an insulating film. A third step;
   A fourth step of cutting the surface electrode film formed in the first step and the insulating film formed in the third step to form the first gap and the second gap. When,
   A shape having the central portion and the both side portions, the central portion is provided in the first gap and the second gap, and an electrostatic protection paste is screen printed so that the both side portions are overlaid on the upper surface of the insulating film. And baking the screen-printed electrostatic protection paste film to form the electrostatic protection film,
   A method for producing an electrostatic protection component, comprising:
5. In the manufacturing method of the electrostatic protection component described in Claim 4,
   Performing the second step after the first step;
   And in the second step, firing the back electrode at a peak temperature lower than the peak temperature when firing the front electrode film in the first step,
   A method of manufacturing an electrostatic protection component characterized by the above.
6. In the method for manufacturing an electrostatic protection component according to any one of claims 3 to 5,
   The peak temperature when baking the said surface electrode film | membrane at a said 1st process is 900 degreeC, The manufacturing method of the electrostatic protection component characterized by the above-mentioned.

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