KR101450417B1 - Electrostatic protection component and production method therefor - Google Patents

Abstract

An object of the present invention is to provide an electrostatic protection component and a method of manufacturing the same that can minimize the deterioration of insulation resistance after ESD voltage is applied and can minimize variation of insulation resistance of each component. The configuration of the electrostatic protection component 100 includes surface electrodes 2a and 2b formed on the ceramic substrate 1 and opposed to each other via the gap 4a and surface electrodes 2a and 2b, 2b-3 and 2b-3 of the surface electrodes 2a and 2b and the side surfaces 2a-4, 2a-5, 2b-4 and 2b-5 of the surface electrodes 2a and 2b, Glass films 21a and 21b which are opposed to each other via a gap 4b following the center portion 5c and both side portions 5a and 5b and a central portion 5c are formed in the gaps 4a and 4b, The side portions 5a and 5b have the electrostatic protection film 5 overlapping the upper surfaces 21a-2 and 21b-2 of the glass films 21a and 21b.

Description

TECHNICAL FIELD [0001] The present invention relates to an electrostatic protection component,

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

2. Description of the Related Art In recent years, electronic devices such as portable information devices are being made smaller and more sophisticated, but the withstanding voltage of electronic devices has been reduced accordingly. For this reason, static electricity protection parts are used for electronic devices such as portable information devices in order to protect the electronic devices from overvoltage applied by electrostatic pulses or extraneous noise.

The electrostatic protection component is provided with a surface electrode facing each other with a gap interposed therebetween and an electrostatic protective film formed in the gap. The electrostatic protection component is formed between a line and a ground in which an overvoltage may be applied in an electronic device, (I.e., the electrostatic protection film) between the surface electrodes to protect the electronic device from the overvoltage.

In addition, as a prior art document in which a conventional electrostatic protection component is disclosed, there is, for example, the following Patent Document 1. Japanese Patent Application Laid-Open No. 2009-194130

BACKGROUND ART At present, with the advancement of miniaturization and high performance of electronic devices such as portable information devices, there is a growing demand for an overvoltage protection function for electrostatic protection components, and thus it is claimed that various characteristics of the electrostatic protection components are improved.

Among the various characteristics of electrostatic protection parts, insulation resistance is one of the most important ones. It is preferable that the insulation resistance is as large as possible (that is, the leakage current is as small as possible), and the deviation of the insulation resistance (leakage current) is preferably as small as possible. However, the insulation resistance is lowered after application of an ESD (Electro-Static Discharge) voltage to the electrostatic protection component, and further tends to decrease as the number of times of application of the voltage increases.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an electrostatic protection component and a method of manufacturing the same that can minimize the decrease in insulation resistance after ESD voltage application and minimize variations in insulation resistance for each component .

As measures for solving the above problems, there are roughly divided measures for studying the structure of the electrostatic protection part and measures for studying the material of the electrostatic protection film. The present invention focuses on the electronic countermeasures and is obtained as a result of intensive studies on the structure of the electrostatic protection component, and has the following features.

That is, the electrostatic discharge protection component of the first invention comprises: a surface electrode which is formed on an insulating substrate and which is opposed to the surface electrode via a first gap;

An insulating film formed on the surface electrode and covering the upper surface and both side surfaces of the surface electrode and opposed to each other via a second gap following the first gap;

And an electrostatic protection film having a central portion and both side portions, the central portion being formed in the first gap and the second gap, and the both side portions being overlapped with the upper surface of the insulating film.

The electrostatic discharge protection component of the second invention is the electrostatic discharge protection component of the first invention,

The insulating film is a glass film.

The electrostatic discharge protection component of the third invention is the electrostatic discharge protection component of the first or second invention,

An intermediate layer is formed between the electrostatic protective film and the protective film,

And the insulating film is sandwiched between the intermediate layer and the surface electrode.

The method for manufacturing an electrostatic protection component of the fourth invention is the method for manufacturing the electrostatic protection component of the first invention,

A first step of forming a film of a surface electrode on an insulating substrate,

A second step of forming an insulating film on the film of the surface electrode and covering the upper surface and both side surfaces of the film of the surface electrode with the insulating film;

A third step of forming a first gap and a second gap by cutting the film of the surface electrode formed in the first step and the insulating film formed in the second step,

And a fourth step of forming the central portion in the first gap and the second gap in such a shape as to have the central portion and the both side portions and overlapping the both side portions on the upper surface of the insulating film to form the electrostatic protective film .

The method of manufacturing an electrostatic protection component of a fifth invention is the method of manufacturing an electrostatic protection component of the fourth invention,

The insulating film is a glass film.

The method for manufacturing an electrostatic protection component of a sixth invention is the method for manufacturing an electrostatic protection component according to the fourth or fifth invention,

In the third step, the film of the surface electrode formed in the first step and the insulating film formed in the second step are cut at the same time by using a third harmonic laser having a UV wavelength region, And a second gap is formed.

According to a first aspect of the present invention, there is provided an electrostatic protection device comprising: a surface electrode formed on an insulating substrate and opposed to a surface of the surface electrode through a first gap; a first electrode formed on the surface electrode and covering an upper surface and both surfaces of the surface electrode, An insulating film facing each other through a second gap following the first gap, an electrostatic protection film having a central portion and both side portions, the central portion being formed in the first gap and the second gap, The electrostatic protection film is formed only on the first gap between the surface electrodes with respect to the surface electrode. That is, the electrostatic protection film is in contact with only the end face on the gap side with respect to the surface electrode, and is not in contact with the portion other than the end face.

Therefore, in the electrostatic protection device of the first invention, the insulation resistance can be made much larger than that of the electrostatic protection device in which the electrostatic protection film is also in contact with a portion other than the end surface of the surface electrode. Further, Can be made very small.

According to the electrostatic protection device of the second invention, in the electrostatic protection device of the first invention, since the insulating film is a glass film, it is easy to form a glass film having heat resistance and insulation at the time of manufacturing the electrostatic protection component And can be carried out at low cost.

According to the electrostatic protection device of the third invention, in the electrostatic protection device of the first or second invention, an intermediate layer is formed between the electrostatic protection film and the protective film, and the insulating film is interposed between the intermediate layer and the surface electrode The intermediate layer does not contact the surface electrode due to the presence of the insulating film. Therefore, it is possible to reliably prevent the occurrence of an abnormal discharge between the surface electrodes through the intermediate layer by the insulating film. In this case, for example, it is also possible to form the intermediate layer by using a material having a relatively low insulating property, so that an effect of broadening the selection of the material of the intermediate layer is also obtained.

According to a fourth aspect of the present invention, there is provided a method of manufacturing an electrostatic protection component according to the first aspect of the invention, comprising: a first step of forming a film of a surface electrode on an insulating substrate; A second step of covering the upper surface and both side surfaces of the film of the surface electrode with the insulating film; a step of cutting the film of the surface electrode formed in the first step and the insulating film formed in the second step, A third step of forming a second gap and a step of forming a central portion in the first gap and a second gap in a shape having a central portion and both side portions and overlapping the both side portions on the upper surface of the insulating film to form an electrostatic protective film The electrostatic protection film can be formed only on the first gap between the surface electrodes with respect to the surface electrode. That is, the electrostatic protection film can be formed so as to be in contact with only the end face on the gap side with respect to the surface electrode and not with the portion other than the end face.

Therefore, in the electrostatic protection device manufactured by the method for manufacturing an electrostatic protection device of the fourth invention, the insulation resistance can be made much larger than the electrostatic protection device in which the electrostatic protection film is also in contact with a portion other than the end surface of the surface electrode, , And the deviation of the insulation resistance of each component can be made very small.

According to the method of manufacturing an electrostatic protection component of the fifth invention, in the method of manufacturing an electrostatic protection component of the fourth invention, since the insulating film is a glass film, it is easy to form a glass film having heat resistance and insulation And can be carried out at low cost.

According to a sixth aspect of the present invention, there is provided a method of manufacturing an electrostatic protection component according to the fourth or fifth aspect of the invention, wherein in the third step, a film of the surface electrode formed in the first step, The first gap and the second gap are formed by simultaneously cutting the insulating film formed in the second step using a third harmonic laser having a UV wavelength region, Can be easily formed with good precision.

Fig. 1 is a cross-sectional view (sectional view taken along the line BB in Fig. 2) showing the structure of the electrostatic protection component according to the embodiment of the present invention.
2 is a top view (A directional view in Fig. 1) showing the structure of an electrostatic discharge protection component according to an embodiment of the present invention.
3 (a) is a cross-sectional view taken along line CC of FIG. 1, and FIG. 1 (b) is a cross-sectional view taken along the line DD of FIG.
4 is a cross-sectional view showing the structure of an electrostatic protection component of a comparative example.
5 is a flowchart showing a manufacturing process of an electrostatic protection component according to an embodiment of the present invention.
6 is a first explanatory diagram of a manufacturing process of an electrostatic protection component according to an embodiment of the present invention.
7 is a second explanatory diagram of a manufacturing process of an electrostatic protection component according to an embodiment of the present invention.
8 is a third explanatory diagram of a manufacturing process of an electrostatic protection component according to an embodiment of the present invention.
FIG. 9A is a table showing ESD suppression peak voltage measurement results of the electrostatic protection parts (with a glass film) of the present invention (embodiment), FIG. 9B is a table showing ESD suppression peak voltage measurements of electrostatic protection parts This is a table showing the results.
10A is a table showing results of leakage current measurement of electrostatic protection parts (with a glass film) of the present invention (embodiment), and FIG. 10B is a table showing results of leakage current measurement of the electrostatic protection parts of the comparative example.
Fig. 11 is a cross-sectional view (FF line arrow cross-sectional view in Fig. 12) showing another structural example (structural example of the glass film portion) of the electrostatic protection component according to the embodiment of the present invention.
Fig. 12 is a top view (E direction arrow in Fig. 11) showing another structural example (structural example of the glass film portion) of the electrostatic protection component according to the embodiment of the present invention.
13 (a) is a sectional view taken along the line GG in Fig. 11, and Fig. 13 (b) is a sectional view taken along the line HH in Fig.
Fig. 14 is a cross-sectional view (cross-sectional view taken along the line JJ in Fig. 15) showing another structural example (structural example of the glass film portion) of the electrostatic protection component according to the embodiment of the present invention.
Fig. 15 is a top view (I-direction arrow in Fig. 14) showing another structural example (structural example of the glass film portion) of the electrostatic protection component according to the embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

First, a structure of an electrostatic protection component according to an embodiment of the present invention will be described with reference to Figs. 1 to 3. Fig.

The electrostatic protection device 100 shown in Figs. 1 to 3 is a component for surface mounting on a printed circuit board of an electronic device such as a portable information device. The electronic circuit (electronic component) mounted on the printed circuit board is subjected to electrostatic discharge And is formed between the line and the ground in which the overvoltage is likely to be applied in the electronic apparatus in order to protect it from overvoltage due to extraneous noise.

Surface electrodes 2a and 2b are formed on the surface 1a of the ceramics substrate 1 as an insulating substrate and back electrodes 1b are formed on the back surface 1b of the ceramic substrate 1, , 3b are formed. The front surface electrodes 2a and 2b are formed over the entire lengthwise direction of the substrate surface 1a while the back surface electrodes 3a and 3b are formed at both end portions of the back surface of the substrate 1b.

A gap (narrow portion) 4a (first gap) is formed between the surface electrodes 2a and 2b at the central portion of the substrate surface 1a. That is, the surface electrodes 2a and 2b are opposed to each other via the gap 4a. The gap 4a is formed by cutting a surface electrode film by a cutting means such as a laser method and has a width d of about 10 占 퐉 (7 占 퐉 in the present embodiment).

A glass film 21a serving as an insulating film is formed on the surface electrode 2a (in the vicinity of the gap), and a glass film 21b serving as an insulating film is formed on the surface electrode 2b (in the vicinity of 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 via the gap 4b. The gap 4b has a width d of about 10 占 퐉 (7 占 퐉 in the present embodiment) formed by cutting the glass film by a cutting means such as a laser method in the same manner as the gap 4a, ). The gap 4a in the lower layer overlaps the gap 4b in the upper layer.

The gap 2a-1 on the gap side of the surface electrode 2a is formed such that the upper surface 2a-3 and both side surfaces 2a-4 and 2a-5 (i.e., the portion other than the end surface 2a- , And is covered with a glass film 21a (see Fig. 3 (a) in particular). Similarly, the gap portion 2b-1 on the gap side of the surface electrode 2b is formed so that the upper surface 2b-3 and both side surfaces 2b-4 and 2b-5 (i.e., Portion) is covered with the glass film 21b (particularly, see 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. Since the end portion 2a-1 of the surface electrode 2a is covered with the glass film 21a except for the end surface 2a-6 on the gap side, the electrostatic protective film 5 is formed on the surface electrode 2a But is in contact with only the end face 2a-6 and not with the other end face 2a-6. Likewise, since 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, the electrostatic protective film 5 is formed on the surface electrode 2b But is not in contact with a portion other than the cross section 2b-6.

More specifically, the electrostatic protection film 5 has a T-shape in longitudinal section (see FIG. 1), and has a central portion 5c and both side portions 5a and 5b. The central portion 5c of the electrostatic protection film 5 is formed in the gaps 4a and 4b as described above (that is, the gaps 4a and 4b are closed) 21b-2 of the end portions 21a-1, 21b-1 on the gap sides of the glass films 21a, 21b (i.e., the glass films 21a, 21b) Lt; / RTI >

As a result of intensive studies on the structure of the electrostatic protection component, it is preferable to form the electrostatic protection film 5 only in the gap 4a between the surface electrodes 2a and 2b in order to minimize the decrease of the insulation resistance after application of the ESD voltage .

However, when the electrostatic protection film 5 is formed directly on the surface electrodes 2a and 2b by a screen printing method without forming a glass film, as in the electrostatic protection device 200 of the comparative example shown in Fig. 4, It is impossible to form the electrostatic protective film 5 only on the gap 4a so that the both side portions 5a and 5b of the electrostatic protective film 5 are covered with the surface electrodes 2a and 2b, 3 and 2b-3 of the end portions 2a-1 and 2b-1 of the side wall 2a.

Thus, in the present invention, the manufacturing method is studied, and glass films 21a and 21b are formed on the surface electrodes 2a and 2b as shown in FIG. 1 and the like. Thereafter, from the glass films 21a and 21b, A method of forming the electrostatic protection film 5 was carried out. As a result, not only the electrostatic protective film 5 (the central portion 5c) is formed in the gap 4b but also the both end portions 5a and 5b of the electrostatic protective film 5 are covered with the glass films 21a and 21b Glass films 21a and 21b which are overlapped with the upper surfaces 2a-3 and 2b-3 at both ends 5a and 5b of the electrostatic protection film 5 are formed on the surface electrodes 2a and 2b, The electrostatic protection film 5 (central portion 5c) can be formed only in the gap 4a.

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

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, zinc oxide having an insulating property of the first kind according to the JIS standard, that is, zinc oxide having a volume resistivity of 200 M? Cm or more is used. The blending ratio of the silicone resin, the aluminum powder and the zinc oxide is 100 parts by weight, and the aluminum powder is 160 parts by weight or more and the zinc oxide powder is 120 parts by weight. The mixing ratio of this electrostatic protection paste should be such that the ESD suppression peak voltage is 500 V or less and the ESD tolerance (20 times voltage) is the target value of the leakage current of 10 ㎂ or less (insulation resistance R = 3 MΩ or more) , And the electrostatic protection devices 100 and 200 of the present invention and the comparative example. However, the static electricity protection component 100 of the present invention has a smaller leakage current (see FIG. 10: detailed later). Therefore, the electrostatic protection device 100 of the present invention has improved insulation. The ESD suppression peak voltage is a voltage generated at the start of discharge.

Upper electrodes 6a and 6b are formed on the surface electrodes 2a and 2b, respectively. Since the surface electrodes 2a and 2b are thin films, the mechanical strength of the surface electrodes 2a and 2b is reinforced by the upper electrodes 6a and 6b. However, the upper electrodes 6a and 6b are formed so as not to be in contact with the electrostatic protection film 5 (in 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 the electrostatic pulse or the like is applied to the electrostatic protection component 100, not between the surface electrodes 2a and 2b, Discharge may start between the electrodes 6a and 6b or between the upper electrodes 6a and 6b and the surface electrodes 2a and 2b and in this case the static electricity protection function inherent to the electrostatic protection part can not be exerted to be.

The glass films 21a and 21b which are insulating films are not formed under the upper electrodes 6a and 6b.

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

The protective film 8 is excellent in moisture resistance and is formed to protect the electrostatic protection film 5 from an external environment such as humidity. However, since the protective film 8 is insufficient in heat resistance, the electrostatic protective film 5, which generates heat during discharging, is not directly covered with the protective film 8, and the electrostatic protective film 5 is covered with the intermediate layer 7 having excellent heat resistance , And the intermediate layer 7 is covered with the protective film 8.

The intermediate layer 7 also has a function of avoiding occurrence of abnormal discharge between the surface electrodes 2a and 2b. The intermediate layer 7 is a flexible material (elastomer) obtained by adding an appropriate amount of an inorganic filler such as silica to a resin material such as a silicone resin to form a gap 4a between the surface electrodes 2a and 2b A function of preventing the rise of the internal energy (internal pressure) at the time of discharging in the internal space (absorbing the internal energy) to prevent the damage of the electrostatic protection component 100 due to the impact caused by the rise of the internal energy Buffering function).

Sectional electrodes 9a and 9b are formed on both end faces 1c and 1d of the ceramic substrate 1. The surface electrodes 2a and 2b and the back electrodes 3a and 3b are formed by these end face electrodes 9a and 9b, 3b are electrically connected to each other. The end portions 9a-1, 9a-2, 9b-1 and 9b-2 of the end surface electrodes 2a and 2b and the end portions 2a-2 and 2b- The connection between the cross-section electrodes 9a and 9b and the surface electrodes 2a and 2b and the backside electrodes 3a and 3b is more preferable because the electrodes 3a and 3b are overlapped with the end portions 3a-1 and 3b- It is clear.

Plating films 11a and 11b of nickel (Ni) plated films 10a and 10b and tin (Sn) are formed in order to improve the reliability of the terminal electrodes with respect to the end surface electrodes 9a and 9b . The nickel plated films 10a and 10b cover the end faces 9a and 9b and the back face electrodes 3a and 3b and a part of the face electrodes 2a and 2b and the upper electrodes 6a and 6b And the tin plating films 11a and 11b cover the nickel plating films 10a and 10b, respectively.

Next, a method of manufacturing the electrostatic protection device 100 of this embodiment will be described with reference to Figs. 5 to 8. Fig. In each manufacturing step (step) in the flowchart of Fig. 5, the symbols S1 to S20 are given. 6A to 6D, Figs. 7A to 7D, and 8A to 8D show the manufacturing states of the electrostatic protection device 100 in each manufacturing step in the order .

In this embodiment, a 1005 type electrostatic protection device 100 (having a width W of 0.5 mm and a length L of 1.0 mm shown in Fig. 2) was manufactured.

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

6A shows only one piece of the ceramic substrate 1 corresponding to one piece of the electrostatic protection component 100. However, in the step S15, the actual ceramic substrate 1 before the first division (1) is a sheet-like sheet in which a plurality of primary slits and secondary slits are formed longitudinally and laterally, and a plurality of rearranged regions are vertically and horizontally connected.

In the next step (step S2), the back electrodes 3a and 3b are formed on the back surface 1b of the ceramics substrate 1 as shown in Fig. 6 (b). The back electrodes 3a and 3b are formed by applying an electrode paste to the back surface 1b of the substrate by a screen printing method and patterning them. Here, silver (Ag) paste was used as an electrode paste. The screen-printed back electrodes 3a and 3b are dried to evaporate the solvent in the electrode paste.

In the next step (step S3), as shown in Fig. 6 (c), the surface electrode 2a of the surface electrode 2 (surface electrodes 2a and 2b in the later process) Is formed. The film 2 of the surface electrode is formed by applying an electrode paste to the substrate surface 1a by screen printing and patterning it. In this case, a gold resinate paste was used as an electrode paste. The film of the screen-printed surface electrode 2 is dried to evaporate the solvent in the electrode paste.

As the electrode paste for forming the film of the surface electrode 2, a resin paste other than gold (metal organic paste) may be used. For example, a resin paste of platinum (Pt) or silver (Ag) can be used. As the electrode paste for forming the back electrodes 3a and 3b, silver-palladium (Ag · Pd) paste may be used.

In the next step (step S4), the back electrodes 3a and 3b formed in step S2 and the surface electrodes 2 formed in step S3 are simultaneously fired at a temperature of 850 DEG C for 40 minutes.

6 (d), a glass film 21 (a film for forming the glass films 21a and 21b in a later process) is formed in the central portion of the surface electrode 2 in the next step (step S5) . The glass film 21 is formed by applying a borosilicate glass paste to the surface electrode 2 (covering the center portion of the surface electrode 2) by screen printing and patterning.

In the next step (step S6), the glass film 21 formed in step S5 was fired at a temperature of 600 占 폚.

In the next step (step S7), as shown in Fig. 7 (a), the central part of the glass film 21 fired in step S6 and the central part of the glass film 21 fired in step S4 The upper portion gap 4b and the lower layer gap 4a are formed at the same time by cutting the central portion of the surface electrode 2 fired at the same time. Here, a third harmonic laser (wavelength: 355 nm) was used as a laser having a UV wavelength range. The width d of the gaps 4a and 4b was set to 7 mu m. As a result of forming the gaps 4a and 4b, a pair of surface electrodes 2a and 2b are opposed to each other via the gap 4a and a pair of glass films 21a , 21b are opposed to each other.

In the next step (Step S8), as shown in Fig. 7 (b), the conductive paste is applied to each of the surface electrodes 2a and 2b by screen printing to pattern the surface electrodes 2a and 2b The upper electrodes 6a and 6b are formed. The number of times of screen printing at this time is one. The upper electrodes 6a and 6b are formed so as to overlap with the surface electrodes 2a and 2b at positions away from the electrostatic protection film 5 in order to prevent them from coming into contact with the electrostatic protection film 5. [ The upper electrodes 6a and 6b after the 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 占 占 퐉 (part number: st400).

As the conductive paste, silver powder and epoxy resin were mixed and kneaded. The present invention is not limited to this, and a thick film electrode paste or the like obtained by kneading an epoxy resin with nickel (Ni), copper (Cu) powder or the like may be used as the conductive paste for the upper electrode.

In the next step (step S9), as shown in Fig. 7 (c), the electrostatic protection film 5 is formed by applying the electrostatic protection paste to the gaps 4a and 4b and patterning them by screen printing do. At this time, the electrostatic protection film 5 has a shape having a central portion 5c and both side portions 5a and 5b. The central portion 5c of the electrostatic protection film 5 is formed only on the gap 4a (covering the gap 4a) and connected to the surface electrodes 2a and 2b, The central portion 5c of the electrostatic protection film 5 is formed in the gap 4b and the both ends 5a and 5b of the electrostatic protection film 5 are covered with the glass film (End portions on the gap side) of the upper surfaces 21a-2 and 21b-2 of the first and second electrodes 21a and 21b.

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

The screen mesh used in this screen printing is a calendered mesh having a mesh size of 400, a line diameter of 18 mu m and an emulsion thickness of 5 +/- 2 mu m (part number: cal400 / 18).

The electrostatic protection paste used here is obtained by kneading two kinds of the aluminum powder used as the conductive particles and the zinc oxide powder used as the insulating particles in the silicone resin with the base material of the silicone resin as the base material. The mixing ratio of these three components was 160 parts by weight of the aluminum powder and 120 parts by weight of the zinc oxide powder while the silicone resin was 100 parts by weight. In this case, the target value of the ESD suppression peak voltage is 500 V or less and the ESD internal capacity is a leakage current of 10 ㎂ or less (insulation resistance R = 3 MΩ or more).

In addition, a silicone resin with, an addition reaction type silicone resin of the volume resistivity of 2 × 10 ¹⁵ Ω㎝, dielectric constant of 2.7 was used.

As the aluminum powder, aluminum powder having an average particle size of 3.0 to 3.6 mu m, which is obtained by melting aluminum, spraying it under high pressure, and cooling and solidifying it, was used.

As the zinc oxide powder, zinc oxide having a type 1 insulating property (volume resistivity of 200 M? Cm or more) according to JIS standard was used. The zinc oxide powder used was a zinc oxide powder having a particle diameter of 0.3 to 1.5 占 퐉, an average particle diameter of 0.6 占 퐉, and a particle diameter of 1.5 占 퐉 in primary agglomeration.

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

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 to form a pattern, The intermediate layer 7 covering the protective film 5 and the like is formed. The number of times of screen printing at this time is one.

Here, a silicone resin paste containing 40 to 50% of silica as a silicone resin paste was used.

The screen mesh used in the screen printing is a calendered mesh having a mesh size of 400, a line diameter of 18 mu m and an emulsion thickness of 5 +/- 2 mu m (part number: cal400 / 18).

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

In the next step (Step S13), an epoxy resin paste is applied to the intermediate layer 7, the glass films 21a and 21b, the surface electrodes 2a and 2b, Is applied to the upper electrodes 6a and 6b to be patterned to form a protective film 8 covering the intermediate layer 7 and the like. The number of times of screen printing at this time is two.

The screen mesh used in the screen printing had a mesh size of 400 and an emulsion thickness of 10 ± 2 μm (part number: 3DSus 400/19).

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

In the next step (Step S15), the ceramics substrate 1 is firstly divided along the primary slits formed in the sheet-like ceramic substrate 1. Then, As a result, the ceramic substrate 1 is formed into a strip-like shape in which a plurality of separate regions are connected in a row in a line, and the end faces 1c and 1d are formed.

In the next step (step S16), as shown in Fig. 8 (b), the conductive paste is applied to the end faces 1c and 1d of the ceramics substrate 1, a part of the surface electrodes 2a and 2b And the back electrode portions 3a and 3b are baked at a temperature of 200 DEG C for 30 minutes in the next step (Step S17) to form the end surface electrodes 9a and 9b. At this time, the cross-section electrodes 9a and 9b partially overlap the surface electrodes 2a and 2b and the back surface electrodes 3a and 3b to electrically connect the surface electrodes 2a and 2b and the back surface electrodes 3a and 3b.

Here, a paste obtained by kneading a silver powder and an epoxy resin as a conductive paste was used.

In the next step (Step S18), the ceramics substrate 1 is secondarily divided along the secondary slits formed in the strip-shaped ceramic substrate 1. Then, As a result, the ceramic substrate 1 is divided for each reorganization area and is reorganized.

In the next step (Step S19), the end face electrodes 9a and 9b, the back face electrodes 3a and 3b and the face electrodes 2a and 2b are formed by a barrel plating method, as shown in Fig. 8 (c) And a part of the upper electrodes 6a and 6b are electroplated to form nickel plated films 10a and 10b.

In the last step (step S20), the nickel plating films 10a and 10b formed in step S19 are electroplated by a barrel plating method to form tin plating films 11a and 11b ). Thus, the electrostatic protection component 100 is completed.

9 and 10, the electrostatic protection device 100 (FIG. 1) having the glass films 21a and 21b of the present invention and the ESD protection device 200 having no glass film of the comparative example The results of the test will be described.

The ESD test was performed by applying an ESD voltage conforming to IEC61000-4-2 8 kV to the electrostatic protection components 100 and 200.

For the electrostatic protection component 100 of the present invention, 10 samples were produced in the same manufacturing process as described above. For the electrostatic protection component 200 of the comparative example, 10 samples . The ESD voltage was applied to all the samples 20 times.

9 (a) shows the result of measurement of the ESD suppression peak voltage at the first application of the ESD voltage to the sample of the electrostatic protection device 100 of the present invention. Fig. 9 (b) Shows the measurement result of the ESD suppression peak voltage at the time of the first application of the ESD voltage to the sample of Fig.

From these measurement results, with respect to the ESD suppression peak voltage, all the samples satisfied the target value of 500 V or less, and no significant difference was observed in both samples.

On the other hand, FIG. 10 (a) shows the results of measurement of leak current after the first, 10th and 20th ESD voltage application to the sample of the electrostatic protection device 100 of the present invention, Shows the result of measuring the leak current after the application of the ESD voltage for the 20th time to the sample of the example electrostatic protection component 200. [

As shown in Fig. 10 (a), in the electrostatic protection device 100 of the present invention, even when ESD voltage is applied to all the samples in the first, the 10th, and the 20th, the leakage current is 0.001 라는 And the leak current of each sample (component) was not substantially varied. That is, it was confirmed that all the samples had very high insulation resistance, and there was almost no variation in insulation resistance for each sample.

On the other hand, as shown in Fig. 10 (b), the static electricity protection component 200 of the comparative example satisfies the target value that all the samples are 10 占 이하 or less. Compared with the result of Fig. 10 (a) A large amount of current samples were observed, and a variation in leakage current for each sample was also very large. That is, it was confirmed that the insulation resistance was relatively small and the variation of insulation resistance per sample was large.

The structure of the glass films 21a and 21b is not limited to the structures shown in Figs. 1 to 3, and may be a structure shown in Figs. 11 to 13, or a structure shown in Figs. 14 and 15, for example.

1 to 3 (particularly Figs. 2 and 3), the glass films 21a and 21b are provided in the electrostatic protection component 300 shown in Figs. 11 to 13 in detail, (See Figs. 12 and 13: the upper and lower directions in these drawings are the width direction of the glass films 21a and 21b).

2 and 3, the glass films 21a and 21b of the electrostatic protection device 100 are wider than the widths of the surface electrodes 2a and 2b, but the glass films 21a and 21b of the electrostatic protection film 5 4a and 2a-5 of the front-surface electrode 2a and both side surfaces 2b-4 and 2b of the front-surface electrode 2b, and the side surfaces 2a-4 and 2a- 5, 2b-4, and 2b-5 are prevented from coming into contact with the electrostatic protection film 5. On the other hand, as shown in Figs. 12 and 13, the glass films 21a and 21b of the electrostatic protection component 300 are formed so that the width of the surface electrodes 2a and 2b, the width of the electrostatic protection film 5, And has a width wider than any of the widths of the intermediate layer 7.

The other structure of the electrostatic protection component 300 is the same as that of the electrostatic protection component 100. [ The manufacturing method of the electrostatic protection component 300 is also the same as the manufacturing method of the electrostatic protection component 100. [

The structure of the K-K line arrow cross section and the L-L line arrow cross section in Fig. 14 is the same as the cross section shown in Fig. 3 (a) and the cross section shown in Fig. 3 (b).

As shown in Figs. 3, 14, and 15, the electrostatic protection component 400 is superior to the electrostatic protection component 100 shown in Figs. 1 to 3 (see Figs. 1 and 2 in particular) 21b are shortened (in particular, see Figs. 14 and 15: the left and right directions in these drawings are the longitudinal directions of the glass films 21a, 21b).

Specifically, as shown in Figs. 1 and 2, the glass films 21a and 21b of the electrostatic protection device 100 are longer than the length of the electrostatic protection film 5 and the length of the intermediate layer 7 have. 14 and 15, the glass films 21a and 21b of 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 The surfaces 2a-1 and 2b-1 of the surface electrodes 2a and 2b are sandwiched between the side portions 5a and 5b of the electrostatic protection film 5 and the surface electrodes 2a and 2b 5b of the electrostatic protection film 5 can be prevented from being in contact with the surface electrodes 2a, 2b by covering the surface electrodes 2a, 2b-3.

The other structure of the electrostatic protection component 400 is the same as that of the electrostatic protection component 100. [ The manufacturing method of the electrostatic protection component 400 is also the same as the manufacturing method of the electrostatic protection component 100. [

As described above, according to the electrostatic protection devices 100, 300, and 400 of the present embodiment, the surface electrodes 2a and 2b formed on the ceramic substrate 1 and opposed to each other via the gap 4a, And is formed on the surface electrodes 2a and 2b to cover the upper surfaces 2a-3 and 2b-3 and both side surfaces 2a-4, 2a-5, 2b-4 and 2b-5 of the surface electrodes 2a and 2b Glass films 21a and 21b opposed to each other via the gap 4b following the gap 4a and a central portion 5c and two side portions 5a and 5b and the central portion 5c has a gap 4a And the electrostatic protection film 5 formed on the gap 4b and the side portions 5a and 5b overlapping the upper surfaces 21a-2 and 21b-2 of the glass films 21a and 21b Therefore, with respect to the surface electrodes 2a and 2b, the electrostatic protection film 5 (central portion 5c) is formed only in the gap 4a between the surface electrodes 2a and 2b. That is, the electrostatic protection film 5 contacts only the end faces 2a-6 and 2b-6 of the gap side with respect to the surface electrodes 2a and 2b and contacts the portions other than the end faces 2a-6 and 2b-6 It is not.

Therefore, the electrostatic protection device 100 can have a significantly higher insulation resistance than the electrostatic protection device 200 that is also in contact with portions other than the end surfaces of the surface electrodes 2a and 2b, In addition, the variation of the insulation resistance of each component can be made very small.

Since the insulating films are glass films 21a and 21b according to the electrostatic protection components 100, 300, and 400, when the electrostatic protection component 100 is manufactured, the glass films 21a And 21b can be easily and inexpensively formed.

According to the electrostatic protection devices 100 and 300, since the glass films 21a and 21b are interposed between the intermediate layer 7 and the surface electrodes 2a and 2b, the glass films 21a and 21b , The intermediate layer 7 does not contact the surface electrodes 2a and 2b. Therefore, it is possible to reliably prevent the occurrence of abnormal discharge between the surface electrodes 2a and 2b through the intermediate layer 7 by the glass films 21a and 21b. In this case, for example, it is possible to form the intermediate layer 7 by using a material having a relatively low insulating property, so that an effect of broadening the material selection of the intermediate layer 7 is also obtained.

According to the method of manufacturing the electrostatic protection device 100 of the present embodiment, the first step of forming the film of the surface electrode 2 on the ceramic substrate 1 and the second step of forming the glass film A second step of covering the upper surface and both side surfaces of the film of the surface electrode 2 with the glass film 21, the film of the surface electrode 2 formed in the first step, A third step of forming a gap 4a and a gap 4b by cutting the glass film 21 formed in the center portion 5c and the second portion 5b so as to form the central portion 5c and the side portions 5a, Is formed in the gap 4a and the gap 4b and the both side portions 5a and 5b are overlapped on the upper surfaces 21a-2 and 21b-2 of the glass films 21a and 21b to form the electrostatic protection film 5, The surface electrodes 2a and 2b are formed only in the gap 4a between the surface electrodes 2a and 2b, (Central portion 5c) can be formed. That is to say, the electrostatic protection film 5 is contacted only to the end faces 2a-6 and 2b-6 of the gap side with respect to the surface electrodes 2a and 2b and the portions other than the end faces 2a-6 and 2b- .

Therefore, the electrostatic protection device 100 manufactured by the present manufacturing method has an insulation resistance greater than that of the electrostatic protection device 200 which is also in contact with the portion other than the end surface of the surface electrodes 2a, 2b And it is possible to make the variation of the insulation resistance for each part very small.

According to the present manufacturing method, since the insulating film is the glass films 21a and 21b, it is possible to easily and inexpensively form the glass films 21a and 21b having heat resistance and insulation.

According to the present manufacturing method, in the third step, the film of the surface electrode 2 formed in the first step and the glass film 21 formed in the second step are separated into a third film having a UV wavelength region And the gaps 4a and 4b are formed by simultaneously cutting them using a harmonic laser so that the gaps 4a and 4b can be easily formed with good precision.

In the above description, the embodiment of the electrostatic protection device in which one electrostatic protection film 5 is formed on one ceramic substrate 1 is described. However, the present invention is not limited to this, The electrostatic protection component in which two or more electrostatic protection films 5 are formed also falls within the scope of the present invention.

In the above description, the case where the electrostatic protective film is formed by using the paste obtained by kneading the three components of the silicone resin, the aluminum powder and the zinc oxide powder is described. However, the present invention is not limited to this, The structure can also be applied to an electrostatic protection component in which an electrostatic protective film is formed by a material having a different component from the above.

Industrial availability

The present invention relates to an electrostatic protection component and a method of manufacturing the same, and is useful when applied to improve the insulation resistance characteristic of the electrostatic protection component.

The surface electrodes 2a-1, 2a-2, 2b-1, 2b-1, and 2b-2 are formed on the surface of the substrate 1, 2a-3, 2b-3: Upper surface of the surface electrode, 2a-4, 2a-5, 2b-4, 2b-5: Side surface of the surface electrode, 2a-6, 5a and 5b side portions of the electrostatic protection film, 5c: central portion of the electrostatic protection film, 5a and 5b, 9a-1, 9a-2, 9b-1, 9b-2: a cross-sectional electrode of the cross-sectional electrode, 6a, 6b: upper electrode, 7: intermediate layer, 8: protective film, 8a, 8b: 1, 21b-1: the end of the glass film, 21a-2, 21b-2: the upper surface of the glass film, 100: electrostatic protection part with glass film, 200: electrostatic protection part without glass film, 300: electrostatic protection part with glass film, 400: has exist)

Claims (6)

A surface electrode formed on the insulating substrate and opposed via the first gap,
An insulating film formed on the surface electrode and covering the upper surface and both side surfaces of the surface electrode and opposed to each other via a second gap following the first gap;
And an electrostatic protection film having a central portion and both side portions, the central portion being formed in the first gap and the second gap, and the both side portions being overlapped with the upper surface of the insulating film,
Wherein the electrostatic protection film is in contact with only the end surface of the first gap side with respect to the surface electrode and is not in contact with a portion other than the end surface of the first gap side. The method according to claim 1,
Wherein the insulating film is a glass film. 3. The method according to claim 1 or 2,
Further comprising a protective film different from the electrostatic protective film,
An intermediate layer is formed between the electrostatic protection layer and the different protective layer,
Wherein the insulating film is sandwiched between the intermediate layer and the surface electrode. A method for manufacturing an electrostatic protection component according to claim 1,
A first step of forming a film of a surface electrode on an insulating substrate,
A second step of forming an insulating film on the film of the surface electrode and covering the upper surface and both side surfaces of the film of the surface electrode with the insulating film;
A third step of forming a first gap and a second gap by cutting the film of the surface electrode formed in the first step and the insulating film formed in the second step,
And a fourth step of forming the central portion in the first gap and the second gap in such a shape as to have a central portion and both side portions and overlapping the both side portions on the upper surface of the insulating film to form an electrostatic protective film ,
Wherein the electrostatic protection film is in contact with only the end surface of the first gap side with respect to the surface electrode and is not in contact with a portion other than the end surface of the first gap side. 5. The method of claim 4,
Wherein the insulating film is a glass film. The method according to claim 4 or 5,
In the third step, the film of the surface electrode formed in the first step and the insulating film formed in the second step are cut at the same time by using a third harmonic laser having a UV wavelength region, Wherein the first gap and the second gap form a gap.

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