CN205141366U

CN205141366U - Esd protective device

Info

Publication number: CN205141366U
Application number: CN201490000538.6U
Authority: CN
Inventors: 足立淳; 安中雄海; 鹫见高弘
Original assignee: Murata Manufacturing Co Ltd
Current assignee: Murata Manufacturing Co Ltd
Priority date: 2013-04-11
Filing date: 2014-04-08
Publication date: 2016-04-06
Anticipated expiration: 2024-04-08
Also published as: WO2014168141A1

Abstract

The utility model provides a messenger ESD protective device that beginning voltage further reduces that discharges. In ESD protective device (1), separating the interval and relatively setting up first, the 2nd discharge electrode (3, 4) on base plate (2), setting up and promote first, the exoelectric auxiliary electrode of discharging (5) between the 2nd discharge electrode (3, 4) for connect a discharge electrode (3) and the 2nd discharge electrode (4), the auxiliary electrode that discharges (5) are by (i) contain the metal and relative dielectric constant is higher than a super set -retarding agent of the high dielectric constant material of base plate, (It is higher than ii) to contain metal and the relative dielectric constant that the material that is not had electric conductivity covered the 2nd super set -retarding agent of the high dielectric constant material of base plate, (It is higher than iii) to contain metal, semiconductor particle and the relative dielectric constant that the material that is not had electric conductivity covered the base plate the 3rd super set -retarding agent of high dielectric constant material, and (iv) contain metal that the material that is not had electric conductivity covered, have relative dielectric constant's below the relative dielectric constant of base plate low dielectric constant material and relative dielectric constant are higher than the base plate the at least a super set -retarding agent who selects in the group of the fourth super set -retarding agent component of high dielectric constant material constitutes.

Description

Esd protection device

Technical field

The utility model relates to the Esd protection device not being subject to electrostatic influence for electronic circuit, particularly relates to the Esd protection device being provided with electric discharge auxiliary electrode.

Background technology

In patent documentation 1 hereafter, disclose the Esd protection device that first, second sparking electrode is set in ceramic multi-layer baseplate.Electric discharge auxiliary electrode is set, is connected with first, second sparking electrode.Electric discharge auxiliary electrode utilizes scatter coated do not have the conductive material of the inorganic material of conductivity and formed.

Another fermentation, in the Esd protection device recorded, also arranges electric discharge auxiliary electrode in following patent documentation 2.In patent documentation 2, as electric discharge auxiliary electrode formation thickener, employing comprises: (1) is at the metal dust of surface attachment grid protocol oxide, (2) at the semiconductor powder of surface attachment metal dust and grid protocol oxide, or (3) are at the metal dust of surface attachment grid protocol oxide, and the thickener of semiconductor powder at surface attachment grid protocol oxide.

Prior art document

Patent documentation

Patent documentation 1:WO2009/098944

Patent documentation 2:WO2013/038893

Utility model content

Utility model technical problem to be solved

In the Esd protection device that patent documentation 1 and patent documentation 2 are recorded, by arranging above-mentioned electric discharge auxiliary electrode, realize the lower voltage of discharge ionization voltage.But, in recent years in order to protect more reliably electronic circuit, be badly in need of discharge ionization voltage is further reduced.

The purpose of this utility model is to provide a kind of Esd protection device that discharge ionization voltage can be made to reduce further.

The technical scheme that technical solution problem adopts

The Esd protection device that the utility model relates to, comprising: substrate; First, second sparking electrode; And electric discharge auxiliary electrode.First, second sparking electrode is arranged on described substrate, relative across gap.Described electric discharge auxiliary electrode is set up makes described first sparking electrode, described second sparking electrode connects, between first, second sparking electrode described, promote electric discharge.Described electric discharge auxiliary electrode comprises metal and relative dielectric constant the first composite material higher than the high dielectric constant material of described substrate by (i); (ii) metal that the material comprising not have electric conducting material covers, and relative dielectric constant is higher than the second composite material of the high dielectric constant material of described substrate; (iii) metal that the material comprising not have electric conducting material covers, semiconductor particle and relative dielectric constant are higher than the 3rd composite material of the high dielectric constant material of described substrate; And the metal that (iv) material of comprising not have electric conducting material covers, select the composite material of at least one to form in the group that the advanced low-k materials of the relative dielectric constant below the relative dielectric constant with described substrate and relative dielectric constant are formed higher than the 4th composite material of the high dielectric constant material of described substrate.

In the Esd protection device that the utility model relates to, preferably, described electric discharge auxiliary electrode comprises space.

In the Esd protection device that the utility model relates to, preferably, the relative dielectric constant of described high dielectric constant material is more than the twice of the relative dielectric constant of described substrate, and less than 10000.

In the Esd protection device that the utility model relates to, preferably, relative dielectric constant is positioned at described gap lower than the low-k part of described substrate.Described low-k part also can be cavity.In addition, low-k part to be formed lower than the solid material of substrate by relative dielectric constant and also can.More preferably, adopt resin as described solid material.

The Esd protection device that the utility model relates to, preferably, also comprises conductor, and this conductor is set to overlap with the gap between first, second sparking electrode described with the part via described substrate.

Preferably, the Esd protection device that the utility model relates to comprises first, second outer electrode, and this first, second outer electrode is arranged on substrate, is electrically connected respectively with the first and second sparking electrode, and described conductor is electrically connected with the first or second outer electrode.Wherein, described conductor can be suspended conductor.

In the Esd protection device that the utility model relates to, preferably, described conductor comprises: metal, and compared with described substrate the material of high-k.

In the Esd protection device that the utility model relates to, first, second sparking electrode described also can be arranged on the outer surface of described substrate.

In addition, in the Esd protection device that the utility model relates to, first, second sparking electrode described also can be arranged in described substrate, and described gap is positioned at substrate.

In the Esd protection device that the utility model relates to, preferably, the described metal in described first composite material is by average grain diameter more than 0.3 μm, and the metallic of less than 1.5 μm is formed.

In the Esd protection device that the utility model relates to, preferably, described high dielectric constant material comprises barium titanate ceramics.

In addition, in the Esd protection device that the utility model relates to, preferably, minimum discharge ionization voltage is expected for below 2kV.

In the manufacture method of the Esd protection device that the utility model relates to, comprise following operation.

Prepare the operation of structure before burning till, this burn till before structure comprise: substrate; First, second sparking electrode, this first, second sparking electrode is relative via gap; And the electric discharge auxiliary electrode do not burnt till, the electric discharge auxiliary electrode that this does not burn till is set to be connected with first, second sparking electrode described, and is made up of electric discharge auxiliary electrode thickener.

By the operation that the above-mentioned electric discharge auxiliary electrode do not burnt till being arranged on above described structure burns till.

In manufacture method of the present utility model, described electric discharge auxiliary electrode thickener comprises (i) and comprises metal and relative dielectric constant the first composite material higher than the high dielectric constant material of described substrate; (ii) metal that the material comprising not have electric conducting material covers, and relative dielectric constant is higher than the second composite material of the high dielectric constant material of described substrate; (iii) metal that the material comprising not have electric conducting material covers, semiconductor particle and relative dielectric constant are higher than the 3rd composite material of the high dielectric constant material of described substrate; And the metal that (iv) material of comprising not have electric conducting material covers, select the composite material of at least one in the group that the advanced low-k materials of the relative dielectric constant below the relative dielectric constant with described substrate and relative dielectric constant are formed higher than the 4th composite material of the high dielectric constant material of described substrate.

In certain particular aspects of the manufacture method of the Esd protection device that the utility model relates to: in described structure; the described electric discharge auxiliary electrode do not burnt till is arranged on the surface of described substrate, and the described first and second sparking electrode is arranged in the surface of described substrate to utilize described electric discharge auxiliary electrode to connect.

In other particular aspects of the manufacture method of the Esd protection device that the utility model relates to, the described electric discharge auxiliary electrode do not burnt till is arranged on the inside of described substrate, and the described first and second sparking electrode is arranged on surface or the inside of described substrate.

Utility model effect

According to the Esd protection device that the utility model relates to, because electric discharge auxiliary electrode is made up of the specific composite material comprising described high dielectric constant material, discharge ionization voltage therefore can be made effectively to reduce.Thus, in electronic circuit etc., more effectively can realize electrostatic defending.

Accompanying drawing explanation

Fig. 1 (a) and Fig. 1 (b) is that the part section that the front cross-sectional view of the Esd protection device that the first execution mode of the present utility model relates to and expression arrange the key component of electric discharge auxiliary electrode amplifies front section view.

Fig. 2 is the schematic plan view of the position relationship of first, second sparking electrode in the Esd protection device representing that the first execution mode relates to, electric discharge auxiliary electrode and conductor.

Fig. 3 is the schematic front profile of the electric discharge auxiliary electrode of the Esd protection device related to for illustration of the second execution mode of the present utility model.

Fig. 4 (a) and Fig. 4 (b) is the front cross-sectional view of the Esd protection device that the 3rd execution mode of the present utility model relates to and represents that the part section of its key component amplifies front section view.

Fig. 5 is the schematic plan view of the position relationship representing first, second sparking electrode, electric discharge auxiliary electrode and conductor.

Fig. 6 is the schematic plan view of the position relationship representing first, second sparking electrode, electric discharge auxiliary electrode and conductor.

Fig. 7 is the schematic plan view of the position relationship representing first, second sparking electrode, electric discharge auxiliary electrode and conductor.

Fig. 8 is the front cross-sectional view of the Esd protection device that the 4th execution mode of the present utility model relates to.

Fig. 9 is the front cross-sectional view of the Esd protection device that the 5th execution mode of the present utility model relates to.

Figure 10 is the front cross-sectional view of the Esd protection device that the 6th execution mode of the present utility model relates to.

Figure 11 is the front cross-sectional view of the Esd protection device that the 7th execution mode of the present utility model relates to.

Figure 12 is the concise and to the point front cross-sectional view of the Esd protection device as embodiment 9 preparation of the present utility model.

Figure 13 is the concise and to the point front cross-sectional view of the Esd protection device as embodiment 10 preparation of the present utility model.

Embodiment

Below, with reference to accompanying drawing, by being described embodiment of the present utility model, the utility model is specified.

Fig. 1 (a) and Fig. 1 (b) is the front cross-sectional view of the Esd protection device that the first execution mode of the present utility model relates to and represents that the part section of its key component amplifies front section view.

Esd protection device 1 has substrate 2.Substrate 2 has the shape of tabular in the present embodiment.Substrate 2 has upper surface 2a and lower surface 2b.In addition, substrate 2 has the first end face 2c, and with the end face i.e. second end face 2d of the first end face 2c opposition side.Substrate 2 is made up of suitable Ins. ulative material.In present embodiment, substrate 2 is made up of ceramic multi-layer baseplate, forms by comprising Ba, Al and Si BAS material as main component.Wherein, substrate 2 also can utilize the low-temperature sintered ceramicss such as glass ceramics (LTCC) to form.In addition, the pottery (HTCC) that aluminium nitride or aluminium oxide etc. also can be utilized to burn till with high temperature.Further, the also magnetic such as available iron oxysome pottery.

In addition, substrate 2 also can utilize the Ins. ulative material beyond pottery to be formed.

The upper surface 2a of substrate 2 is formed the first sparking electrode 3, second sparking electrode 4.First sparking electrode 3 extends to the center side of the upper surface 2a of substrate 2 from the ora terminalis that upper surface 2a and end face 2c is formed.Similarly, the second sparking electrode 4 extends to the center side of the upper surface 2a of substrate 2 from the ora terminalis that end face 2d and upper surface 2a is formed.In the central side portion of the upper surface 2a of substrate 2, the front end of the first sparking electrode 3 is relative across gap with the front end of the second sparking electrode 4.

Electric discharge auxiliary electrode 5 is set to be interconnected with the front end of first, second sparking electrode 3,4.

First, second sparking electrode 3,4 is made up of suitable metal.As such a metal, Cu, Ag, Al, Mo, W can be enumerated or comprise the alloy etc. of these metals.

The feature of the Esd protection device 1 of present embodiment is, electric discharge auxiliary electrode 5 is made up of the composite material comprising specific high dielectric constant material.That is, discharge auxiliary electrode 5 by following i) ~ iv) the group that forms of composite material at least one composite material formation selected.

I () comprises metal and relative dielectric constant the first composite material higher than the high dielectric constant material of described substrate

(ii) comprise the metal covered by the material without conductivity, and relative dielectric constant is higher than the second composite material of the high dielectric constant material of described substrate

(iii) comprise the metal covered by the material without conductivity, semiconductor particle and relative dielectric constant are higher than the 3rd composite material of the described high dielectric constant material of described substrate

(iv) comprise the metal covered by the material without conductivity, the advanced low-k materials of the relative dielectric constant below the relative dielectric constant with described substrate and relative dielectric constant are higher than the 4th composite material of the high dielectric constant material of described substrate

In above-mentioned second ~ four composite material, be not particularly limited for not having the material in the metal of the material covering of conductivity, not there is conductivity.As the material like this without conductivity, can the insulating ceramicses such as aluminium oxide be enumerated, or glass etc.In addition, the above-mentioned metal in the second ~ four composite material is not also particularly limited, the metals such as copper, silver, gold, aluminium, molybdenum, tungsten can be enumerated or based on the alloy of these metals.Preferably, be suitable for adopting copper or take copper as the copper series alloy of principal component.

The feature of the first ~ four composite material is to comprise above-mentioned high dielectric constant material.At this, high dielectric constant material is made up of the suitable material of relative dielectric constant higher than substrate 2.As such a high dielectric constant material, be not particularly limited, such as, can enumerate barium titanate, calcium zirconate, calcium titanate, magnesium titanate, strontium titanates etc.The relative dielectric constant of barium titanate is 2000, and the relative dielectric constant of calcium zirconate is 30.Preferably, the relative dielectric constant of high dielectric constant material expects more than the twice for the relative dielectric constant of substrate 2, and less than 10000.Preferably, expect that the relative dielectric constant of high dielectric constant material is higher.In this situation, easily produce electric field on high dielectric constant material surface when ESD applies and concentrate.Therefore, when applying the ESD of low-voltage, also electric discharge can be produced.High dielectric constant material also can comprise barium titanate ceramics.In this situation, driving voltage and discharge ionization voltage can be made to reduce further.

High dielectric constant material can mix in every way in above-mentioned composite material.Preferably, in the thickener for obtaining above-mentioned first ~ four composite material, also can mix the particle that is made up of above-mentioned high dielectric constant material as raw material.

The average grain diameter of the above-mentioned particle be made up of high dielectric constant material is not particularly limited, but as the value measured by laser diffraction assignment of traffic method, is desirably in more than 0.05 μm, the level of less than 5 μm.The average grain diameter of high dielectric constant material is less, then easily produce electric field and concentrate.Thus, if within the scope of this, then the relative dielectric constant difference between substrate 2 and high dielectric constant material is enough large.Thus, electric field concentration effect hereinafter described and charge effects can effectively be observed.Therefore, effectively discharge ionization voltage can be reduced further.

In second composite material, containing above-mentioned high dielectric constant material, and do not there is the metal of the material covering of conductivity.As the above-mentioned metal covered by the material without conductivity, be not particularly limited to, can be suitable for adopting such as metallic surface by do not have the layer of material covers of conductivity, i.e. so-called core-shell type particle.Or the small particle diameter dusty material in metallic surface attachment without conductivity also can.

First composite material comprises above-mentioned high dielectric constant material and above-mentioned metal.Here as above-mentioned metal, be not particularly limited, Cu, Al, Ag, Au, Mo, W or the alloy etc. based on them can be adopted.Form as above-mentioned metal is not particularly limited, and preferably, expects for metallic.From manufacture method hereinafter described, the calcining of electric discharge auxiliary electrode thickener is utilized can easily to form electric discharge auxiliary electrode.In this situation, in thickener, disperse the particle that above-mentioned metal is formed, easily can form the electric discharge auxiliary electrode comprising above-mentioned metal.

More preferably, the metal average grain diameter in above-mentioned first composite material is more than 0.1 μm, less than 1.5 μm, further preferably expects to be more than 0.3 μm, the metallic of less than 1.5 μm.The average grain diameter of metallic is as described in the explanation of embodiment 5 ~ 10 hereafter, the value of being tried to achieve by following methods.For the Esd protection device obtained from alongst and the face of thickness direction grind, the section of electric discharge auxiliary electrode is exposed.The section of the electric discharge auxiliary electrode exposed with 10000 times of shootings with SEM.That is, reflected electron image is obtained with the multiplying power of 10000 times.Measure the long limit of the metallic existed in this image obtained.This operation is carried out to 10 images, obtains the mean value on the long limit of metallic.Using the average grain diameter of this mean value as metallic.

Above-mentioned average grain diameter reduces, then metallic when applying voltage and easily produce electric field between sparking electrode and concentrate.As a result, effectively discharge ionization voltage can be reduced.In other words, also easily produce creeping discharge when being applied with low-voltage, discharge ionization voltage reduces.Thus, preferably, above-mentioned average grain diameter is less than 1.5 μm.In addition, average grain diameter as described above, is preferably 0.1 μm, further preferably expects to be more than 0.3 μm.This is because if average grain diameter is too small, then metallic can be oxidized, become and be difficult to process.In addition, be difficult to metallic is disperseed equably, esd protection characteristic has the tendency of decline.

In 3rd composite material, except above-mentioned by do not have conductivity material cover metal and above-mentioned high dielectric constant material except, also add semiconductor.Such a semiconductor is not particularly limited, the various semiconductor such as SiC, TiC can be utilized.Form for semiconductor is not also particularly limited.That is, can be semiconductor particle, also can be the semiconductor of other shape had beyond particle.But, during modulation electric discharge auxiliary electrode thickener, semiconductor particle is preferably.Like this, semiconductor particle can be made to disperse equably in electric discharge auxiliary electrode.

In 4th composite material, except the above-mentioned metal covered by the material without conductivity, and outside above-mentioned high dielectric constant material, also mix advanced low-k materials.As advanced low-k materials, the suitable material of relative dielectric constant below the relative dielectric constant of substrate can be adopted.As such a material, the pottery forming substrate 2 can be adopted, or also can adopt the ceramic material beyond the pottery forming substrate 2.As such a pottery, quartz or glass ceramics etc. can be enumerated.Such as, the relative dielectric constant of quartz is 3.8.In addition, advanced low-k materials also can be formed by the material beyond above-mentioned pottery.

As shown in Fig. 1 (b) amplification, above-mentioned electric discharge auxiliary electrode 5 is set to be interconnected with the front end of the first sparking electrode 3 and the second sparking electrode 4.More specifically, electric discharge auxiliary electrode 5 is set to contact with the lower surface of the second sparking electrode 4 with the lower surface of the first sparking electrode 3.But, as long as electric discharge auxiliary electrode 5 is interconnected with the front end of first, second sparking electrode 3,4, the upper surface side of first, second sparking electrode 3,4 can be also arranged on.As long as electric discharge auxiliary electrode 5 is set to be interconnected with first, second sparking electrode 3,4, its flat shape is not particularly limited.

In present embodiment, as shown in Fig. 1 (b), electric discharge auxiliary electrode 5 is disperseed to be formed by metallic 5a, high dielectric constant material particle 5b.That is, in present embodiment, electric discharge auxiliary electrode 5 is made up of the first composite material.More specifically, when manufacturing aforesaid substrate 2, on the ceramic green sheet of the superiors of substrate 2, printing forms the electric discharge auxiliary electrode thickener of electric discharge auxiliary electrode 5, and burns till.Utilization is burnt till, and disperses above-mentioned metallic 5a and high dielectric constant material particle 5b, forms electric discharge auxiliary electrode 5.In addition, around metallic 5a and high dielectric constant material particle 5b, there is the pottery forming aforesaid substrate 2.

Return Fig. 1 (a), in substrate 2, form conductor 6.Conductor 6 is formed on higher position, the centre of substrate 2, is set to overlap with first, second sparking electrode 3,4 across substrate layer.This conductor 6 is made up of suitable metal.As such a metal, be suitable for adopting Cu, Ag, Al, Mo, W or based on the alloy etc. of these metals.

Fig. 2 represents first, second sparking electrode 3,4, the schematic plan view of the position relationship of electric discharge auxiliary electrode 5 and conductor 6.Under overlooking situation, electric discharge auxiliary electrode 5 is arranged in the region comprising first, second sparking electrode 3,4 relative gaps.

Conductor 6 comprises the part in above-mentioned gap, is set to reach first, second sparking electrode 3,4.Thus, conductor 6 is electrically connected with the second outer electrode 10.

Return Fig. 1 (a), at the upper surface 2a of substrate 2, form the first resin bed 7 to fill above-mentioned gap.First resin bed 7 is formed to fill the gap between first, second sparking electrode 3,4, identical with first, second sparking electrode 3,4 thickness.Thus, the upper surface of first, second sparking electrode 3,4 and the upper surface of the first resin bed 7 coplanar.

First resin bed 7 is made up of the resin material of relative dielectric constant lower than substrate 2.That is, although be not particularly limited, arrange the low-k part of relative dielectric constant lower than substrate 2 in gap, this low-k part in the present embodiment, utilizes the first resin bed 7 to be formed.Thus, as the resin of formation first resin bed 7, relative dielectric constant can be adopted lower than the suitable resin of substrate 2.As such a resin, silicones etc. can be enumerated.

At the upper surface of first, second sparking electrode 3,4 and first resin bed 7 above-mentioned, the second resin bed 8 is set.Second resin bed 8 is made up of suitable resin.Preferably, the second resin bed 8 is made up of the resin that relative dielectric constant is higher than the first resin bed 7.As such a resin, the epoxy resin adopting alumina packing or the epoxy resin etc. adopting barium titanate filler can be enumerated.But in present embodiment, first, second resin bed 7,8 also not necessarily must be arranged.Such as, cavity also can be set and replace the first resin bed 7.In addition, first, second resin bed 7,8 also can be formed by same material.

Form first, second outer electrode 9,10 respectively with end face 2c, 2d of covered substrate 2.First, second outer electrode 9,10 is made up of suitable metal.As such a metal, Cu, Al, Au, Ag, Mo, W can be adopted or based on the alloy etc. of these metals.In addition, on the surface of outer electrode 9,10, also Sn coating layer etc. can be formed further.

First sparking electrode 3 is electrically connected with the first outer electrode 9.Second sparking electrode 4 is electrically connected with the second outer electrode 10.Thus, conductor 6 is also electrically connected with the second outer electrode 10 in end face 2d.

The action of Esd protection device 1 is described.

In Esd protection device 1, between the first outer electrode 9 and the second outer electrode 10, apply electrostatic then produce electric discharge.Thus, electronic circuit can be protected not by electrostatic influence.That produce this electric discharge, minimum voltage is discharge ionization voltage.As described above, the further lower voltage of this discharge ionization voltage is required.

In Esd protection device 1, by arranging above-mentioned electric discharge auxiliary electrode 5, promoting electric discharge, reducing discharge ionization voltage.Particularly, because above-mentioned electric discharge auxiliary electrode 5 is made up of at least one in the first ~ four composite material, therefore more effectively discharge ionization voltage can be reduced.Consider that this is caused by following reason.

The starting point of electric discharge is the front end of the first or second sparking electrode 3,4.Further, above-mentioned electric discharge auxiliary electrode 5 is positioned near the front end of the first sparking electrode 3 and the front end of the second sparking electrode 4.That is, the material that relative dielectric constant is different from first, second sparking electrode 3,4 is placed near the front end of first, second sparking electrode 3,4.Therefore, in the further active set of front end electric field energy of first, second sparking electrode 3,4.If electric field concentration degree is improved, then facilitate the movement of the electronics as electric discharge starting point.As a result, can think that discharge ionization voltage is effectively reduced.

Further, owing to adding above-mentioned high dielectric constant material particle 5b in electric discharge auxiliary electrode 5, the electrostatic capacitance between first, second sparking electrode 3,4 raises.As a result, promote charging effect during electric discharge, thus, can think that discharge ionization voltage is further reduced.That is, electric discharge auxiliary electrode 5 in, can think utilize above-mentioned electric field to concentrate promotion, charging effect promotion, effectively reduce discharge ionization voltage.

In addition, in present embodiment, adopt the first composite material in above-mentioned first ~ four composite material, but when adopting the second ~ four composite material, owing to adding high dielectric constant material, utilize electric field to concentrate facilitation effect and charging effect facilitation effect, also reduce discharge ionization voltage.

Further, when adopting the second ~ four composite material, discharge ionization voltage can be reduced further.Consider that this is that following reason caused.

In second composite material, metal is covered by the material without conductivity.Thus, consider this be due to first, second sparking electrode 3,4 between withstand voltage rising or apply electrostatic time short circuit tolerance improve caused.In addition, in the 3rd composite material, can think that discharge ionization voltage is lowered due to the ionization of the electronics from semiconductor, excitation and create electron avalanche energetically.In 4th composite material, can think by dispersion advanced low-k materials, further promote electric field localization effects.

In addition, not being particularly limited containing proportional the high dielectric constant material in the first ~ four composite material, but in the first composite material, the intended volume of above-mentioned metal and high dielectric constant material than be 30/70 ~ 70/30 scope in.Within the scope of this, effectively can reduce discharge ionization voltage further.

In second composite material, the above-mentioned volume ratio expectation by the metal and above-mentioned high dielectric constant material without the material covering of conductivity is in the scope of 40/60 ~ 95/5.

In 3rd and the 4th composite material, the above-mentioned metal that covered by the material without conductivity and the volume ratio of above-mentioned high dielectric constant material also expect be 40/60 ~ 95/5 scope in.

In addition, in the 3rd composite material, the above-mentioned volume ratio expectation by the metal and above-mentioned semiconductor without the material covering of conductivity is in the scope of 20/80 ~ 95/5.Within the scope of this, utilize the interpolation of semiconductor, effectively can reduce discharge ionization voltage further.

In addition, the 4th composite material converge in advanced low-k materials be desirably in occupy 5 ~ 95 volume % scope in add.Within the scope of this, utilize the interpolation of advanced low-k materials, discharge ionization voltage can be lowered further.

In addition, in the Esd protection device 1 of present embodiment, by arranging above-mentioned conductor 6, reduce discharge ionization voltage further.That is, when conductor 6 is set to overlook and first, second sparking electrode 3,4 partially overlap.Thus, between sparking electrode 3,4 and conductor 6, electrostatic capacitance is formed.Particularly, the electric discharge auxiliary electrode 5 comprising high dielectric constant material, between first, second sparking electrode 3,4 and conductor 6, therefore can make above-mentioned electrostatic capacitance increase.Thus, improve charging effect during electric discharge, effectively reduce discharge ionization voltage further.

Conductor 6 is set to overlap with first, second sparking electrode 3,4 relative gaps.Thus, utilize the existence of conductor 6, promote that above-mentioned electric field is concentrated further.Therefore, discharge ionization voltage can be reduced.

In addition, when applying electrostatic, produce heat near gaps.This heat to be rapidly to via the second outer electrode 10 from conductor 6 and around to spread.Thus, can suppress heat deterioration, the repetitive operation characteristic of Esd protection device 1 also can improve.

In above-mentioned first execution mode, electric discharge auxiliary electrode 5 has the metallic 5a making to be covered by the material without conductivity, and the structure that high dielectric constant particles 5b disperses.

On the other hand, in the second execution mode of the present utility model, as shown in Figure 3, the auxiliary electrode 15 that discharges is set to a large amount of formation and is not had metallic 5a, high dielectric constant particles 5b and the space 5c of the material covering of conductivity.That is, in the second execution mode, removing has outside the 5c of space, and electric discharge auxiliary electrode 15 is identical with above-mentioned first execution mode.Thus, by quoting the explanation of the first execution mode, omit the explanation of same section.

Above-mentioned multiple space 5c is dispersed in electric discharge auxiliary electrode 5.In second execution mode, by arranging these spaces 5c, discharge ionization voltage can be reduced further.This is that following reason caused.

The relative dielectric constant difference of high dielectric constant material particle 5b and space 5c is very large.That is, space 5c is the part that there are the gases such as air, and the relative dielectric constant of this part is very low compared with the relative dielectric constant of high dielectric constant material particle 5b.Thus, because this relative dielectric constant difference is improved, therefore electric field concentrates on space 5c.As a result, generating portion electric discharge in the 5c of space.Thus, this partial discharge also produces contribution, promotes electric discharge, reduces discharge ionization voltage further.That is, outside the promotion of above-mentioned electric field localization effects and charging effect, above-mentioned partial discharge also produces contribution, lowers discharge ionization voltage further.

When the electric discharge auxiliary electrode 15 with above-mentioned space 5c is formed, as electric discharge auxiliary electrode thickener, except the metallic 5 covered by the material without conductivity, high dielectric constant material particle 5b and solvent, also can add for the formation of above-mentioned space 5c, burn till time the synthetic resin that can disappear.As such a synthetic resin, the suitable resin that can disappear at the temperature of burning till substrate 2 can be adopted.As such a resin, acrylic resin, polypropylene, polyester etc. can be adopted.

In addition, in the second execution mode, adopt the first composite material in above-mentioned first ~ four composite material, space 5c is set further.In the utility model, when have employed the second ~ four composite material, form space 5c too, thus, discharge ionization voltage can be reduced further.

Further, in first, second execution mode, it is two or more that electric discharge auxiliary electrode 5,15 also can use in the first ~ four composite material in the lump.That is, in the utility model, electric discharge auxiliary electrode can adopt at least one in the first ~ four composite material and form.In this situation, can adopt with a certain part being formed electric discharge auxiliary electrode in the first ~ four composite material, be formed the method etc. of remaining part with other composite material in the first ~ four composite material.

Fig. 4 (a) and (b) are front cross-sectional view and the part section amplification front section view of the Esd protection device that the 3rd execution mode of the present utility model relates to.

The Esd protection device 31 of the 3rd execution mode has substrate 32.Substrate 32 can be same with the substrate 2 with the first execution mode material formed.

First, second sparking electrode 3,4 is set in substrate 32.The front end of first, second sparking electrode 3,4 is relative across gap each other.In addition, form electric discharge auxiliary electrode 5, be connected with first, second sparking electrode 3,4.

First, second sparking electrode 3,4 and electric discharge auxiliary electrode 5 are formed except forming position difference in the same manner as first, second sparking electrode 3,4 of the first execution mode and the auxiliary electrode 5 that discharges.Thus, the explanation of the first execution mode is quoted.

But, in present embodiment, the front end part respect to one another of first, second sparking electrode 3,4 arranges empty 32e.The front end of first, second sparking electrode 3,4 is exposed in this empty 32e.Thus, the gap of the front end of the first sparking electrode 3 and the front end of the second sparking electrode 4 is positioned at empty 32e.Thus, the gas being full of empty 32e is positioned at gap.The relative dielectric constant of gas, such as air is 1.00059.Thus, compared with the relative dielectric constant of substrate, the part forming above-mentioned gap is relatively low low-k part.

In addition, in substrate 2, conductor 6 is set, makes it across substrate layer and electric discharge auxiliary electrode 5 and first, second sparking electrode 3,4 relative.Conductor 6 is formed in the same manner as the conductor 6 of the first execution mode.In present embodiment, above empty 32e, also form conductor 6A.Conductor 6A is formed by the material identical with conductor 6.In addition, the flat shape of conductor 6A and position when overlooking identical with conductor 6.As shown in Fig. 4 (a), conductor 6A is arranged in the region comprising first, second sparking electrode 3,4 relative gaps.

First, second sparking electrode 3,4 is electrically connected with first, second outer electrode 9,10.First, second outer electrode 9,10 is arranged in the same manner as the situation of the first execution mode.

In the Esd protection device 31 of the 3rd execution mode, electric discharge auxiliary electrode 5 is set, to be interconnected with the front end of first, second sparking electrode 3,4.The electric discharge auxiliary electrode 5 of present embodiment is formed in the same manner as the electric discharge auxiliary electrode 5 of the first execution mode.That is, metallic 5a and high dielectric constant material particle 5b is comprised.

In 3rd Esd protection device 31, if electrostatic is applied between first, second sparking electrode 3,4, then creeping discharge and these two discharge paths of air discharge are utilized to discharge.In this situation, because electric discharge auxiliary electrode 5 is made up of the first composite material comprising metallic 5a and high dielectric constant material particle 5b, therefore also effectively can reduce discharge ionization voltage.

In present embodiment, the second ~ four composite material can be adopted to replace the first composite material, in this situation, effectively can reduce discharge ionization voltage further.

In addition, by arranging conductor 6,6A, also discharge ionization voltage can be reduced.

Further, in present embodiment, because conductor 6,6A are electrically connected with the second outer electrode 10, therefore also can reduce discharge ionization voltage further.Further, heat deterioration can also be suppressed.

In addition, in present embodiment, conductor 6A is also set outside conductor 6, discharge ionization voltage can be reduced further.In addition, also conductor 6 or conductor 6A only can be set.

In addition, above-mentioned first, second sparking electrode 3,4, the position relationship of electric discharge auxiliary electrode 5 and conductor 6 is by shown in the schematic plan view of Fig. 5.In present embodiment, electric discharge auxiliary electrode 5 is also arranged on the region comprising above-mentioned gap.In addition, the position overlapped with first, second sparking electrode 3,4 above-mentioned arranges conductor 6.In addition, first, second sparking electrode 3,4, the position relationship of electric discharge auxiliary electrode 5 and conductor 6 is not limited to the mode shown in Fig. 2 and Fig. 5.

Such as shown in Fig. 6, one end of the long side direction of first, second sparking electrode 3,4 not necessarily needs across gap toward each other.That is, also on the Width vertical with length direction, relatively gap can be formed with the side 4a of the front of the second sparking electrode 4 by the side 3a of the first sparking electrode 3.In this situation, as shown in Fig. 6 and Fig. 7, conductor 6A only can be arranged on the part in above-mentioned gap, also can be arranged in the region comprising whole gap.

From the Esd protection device 41 of the 3rd execution mode, in the utility model, first, second sparking electrode 3,4 can be positioned at substrate 32.

Fig. 8 is the front cross-sectional view of the Esd protection device 41 that the 4th execution mode of the present utility model relates to.In the Esd protection device 41 of the 4th execution mode, conductor 6 is not connected with the second outer electrode 10.Other point is identical with the second execution mode.

In addition, Fig. 9 is the front cross-sectional view of the Esd protection device 51 that the 5th execution mode relates to.The Esd protection device 51 of the 5th execution mode is except conductor 6,6A are not electrically connected with the second outer electrode 10, identical with the 3rd execution mode.

Conductor 6 or conductor 6,6A also as the 4th and the 5th execution mode, can be formed as suspended conductor.

In addition, in the first ~ five execution mode, although be provided with conductor 6 or conductor 6,6A etc., also can the Esd protection device 61,71 of the 6th and the 7th execution mode as shown in figs.10 and 11 such, omit conductor 6 or conductor 6,6A.In this situation, utilize electric discharge auxiliary electrode 5, according to the utility model, effectively can reduce discharge ionization voltage.

The manufacture method of the protective device of each ESD of above-mentioned the first ~ seven execution mode is not particularly limited, and preferably, expects the manufacture method employing above-mentioned electric discharge auxiliary electrode thickener.That is, the manufacture method comprising following each operation method is expected.

Prepare the operation of structure before burning till, this burn till before structure comprise: substrate; First, second sparking electrode, this first, second sparking electrode is relative across gap; And the electric discharge auxiliary electrode do not burnt till, the electric discharge auxiliary electrode that this does not burn till is configured to be connected with first, second sparking electrode described, and is made up of electric discharge auxiliary electrode thickener.

The above-mentioned electric discharge auxiliary electrode do not burnt till being arranged on above described structure is carried out the operation of burning till.

As above-mentioned electric discharge auxiliary electrode thickener, at least one composite material containing selecting the group formed from above-mentioned first composite material, the second composite material, the 3rd composite material and the 4th composite material can be adopted.Owing to adopting above-mentioned electric discharge auxiliary electrode thickener, therefore easily and stably Esd protection device of the present utility model can be manufactured.

In the Esd protection device that the utility model relates to, discharge ionization voltage can be reduced as described above, preferably, provide the Esd protection device that can be driven by 2kV.That is, minimum discharge ionization voltage is desirably in below 2kV.

Then, specific embodiment is described.

In addition, the average grain diameter D10 tried to achieve in following experimental example, the value of D50 and D90 are the average grain diameters utilizing laser diffraction flow distribution method to try to achieve.In addition, specific area (SSA) is the value utilizing nitrogen adsorption, tried to achieve by BET1 point method.

(embodiment 1 and comparative example 1)

Based on following main points, make the Esd protection device related to as the embodiment 1 of the embodiment of the 7th execution mode and the comparative example 1 for comparing.

(material of substrate 2)

Prepare the BAS material formed centered by Ba, Al and Si.Relative dielectric constant ε r is adjusted to about 6.In the ceramic powders as the known composition of this BAS material, add mixed toluene and alcohol, then add adhesive resin and plasticizer, obtain ceramic size.Utilize scraping blade method that this ceramic size is shaped, obtain the master slice of the ceramic green sheet of thickness 50 μm.

(electric discharge auxiliary electrode thickener)

Prepare high dielectric constant material powder DM-1 as shown in table 1 below and metallic M-1 as shown in table 2 below.

[table 1]

Table 1

High dielectric constant material powder is numbered	Composition	Relative dielectric constant (ε r)	D50(μm)	SSA(m ²/g)
					DM-1	BaTiO ₃	2000	0.5	1.7

[table 2]

Table 2

Metallic is numbered

Composition

Al measures (wt%)

D10(μm)

D50(μm)

D90(μm)

SSA(m ²/g)

M-1

CuAl alloy

7

1.2

2.5

5

0.58

Al amount is the value utilizing ICP-AES method (inductively coupled plasma emission spectrographic analysis) to try to achieve.In addition, high dielectric constant material powder DM-1 is the BaTiO of 2000 by pulverizing by relative dielectric constant ε r ₃form veneer and obtain.

The cellulose of mixed dissolution 10 % by weight in above-mentioned high dielectric constant material powder DM-1, above-mentioned metallic M-1 and terpinol and the organic carrier that formed, obtain the electric discharge auxiliary electrode thickener P-1 described in following table 3.In addition, as the electric discharge auxiliary electrode thickener used at comparative example 1, prepare electric discharge auxiliary electrode thickener P-2 as shown in table 3 below.In the auxiliary thickener P-2 of electric discharge, as described in Table 3, do not comprise high dielectric constant material powder DM-1, replace containing BaO-SiO ₂-Al ₂o ₃series vitro-ceramic powder.

[table 3]

Table 3

(sparking electrode thickener)

Be the Cu powder of 1 μm by 40 % by weight average grain diameters, 40 % by weight average grain diameters are that the Cu powder of 3 μm and 20 % by weight organic carriers mix, make sparking electrode thickener.In addition, prepare organic carrier by being dissolved in terpinol by ethyl cellulose, make ethyl cellulose containing proportional for above-mentioned 20 % by weight.

(cavity forms thickener)

The crosslinked acrylic resin particle of 38 % by weight average grain diameter 1 μm and 62 % by weight organic carriers that dissolved 10 % by weight ethyl celluloses in terpinol are carried out concocting, mixing, makes cavity and form thickener.

(outer electrode thickener)

By the Cu powder of 80 % by weight average grain diameter 1 μm, inversion point 620 DEG C, softening point 720 DEG C, 5 % by weight average grain diameters be the borosilicic acid alkali metal base frit of 1 μm and ethyl cellulose dissolved obtains in terpinol 15 % by weight organic carriers carry out concocting, mixing, obtain outer electrode thickener.

(manufacturing process)

On the master slice of above-mentioned ceramic green sheet, coating electric discharge auxiliary electrode thickener.Then, by repeating coating, sparking electrode thickener is coated with.Distance between first, second sparking electrode is set to 20 μm.Further, coating cavity forms thickener.

At the patternless ceramic green sheet of stacked on top of one another many pieces of above-mentioned ceramic green sheet, crimp.Like this, the duplexer that thickness is the master slice of 0.3mm is obtained.Cut off the duplexer of this master slice in a thickness direction, cut into the paster in units of each ESD protection device.At this, cut off, make the size of paster have the rectangular planar shape of 1.0mm × 0.5mm.

Then, in nitrogen atmosphere, burn till above-mentioned paster, obtain substrate 2.After burning till, at two end face coating outer electrode thickeners, calcining, forms outer electrode.Obtain the Esd protection device of embodiment 1 and comparative example 1 like this.

(evaluation)

For the Esd protection device of the above-mentioned embodiment 1 that obtains like that and comparative example 1, with IEC specification, IEC61000-4-2 for benchmark, utilize contact discharge, apply ESD from low voltage side.Try to achieve the work ratio of the Esd protection device under each applying voltage.That is, in 100 samples, the number starting the sample discharged is obtained, using this ratio as work ratio.Result is as shown in table 4 below.In addition, the evaluation symbol of work ratio as mentioned below.

◎ ... more than 90% ~ 100%

Zero ... more than 50% ~ 90%

△ ... more than 10% ~ 50%

×…0％～10％

[table 4]

Table 4

As shown in Table 4, in embodiment 1, when being applied with 3kV electrostatic, work ratio is still for more than 10% ~ 50%, and when being applied with the electrostatic of more than 4kV, work ratio is high to 90 ~ 100%.It can thus be appreciated that compared with comparative example 1, according to embodiment 1, work ratio raises, and discharge ionization voltage effectively reduces.

The LCR tester that electrostatic capacitance between first, second outer electrode 9,10 in the Esd protection device of above-described embodiment 1 and comparative example 1 is developed by Agilent company measures.Result as described in Table 5.

[table 5]

Table 5

	Electrostatic capacitance (pF)
		Comparative example 1	0.05
Embodiment 1	0.07

As shown in Table 5, compared with comparative example 1, according to embodiment 1, electrostatic capacitance increases slightly.Electrostatic capacitance increases, then the signal attenuation in high-frequency circuit.Thus, electrostatic capacitance is lower relatively good.The Zener diode etc. that general Esd protection device adopts, in high-frequency circuit, requires that electrostatic capacitance is below 0.5pF.On the other hand, in known embodiment 1, although high dielectric constant material is added in electric discharge auxiliary electrode, electrostatic capacitance is 0.07pF, very not high.That is, the electrostatic capacitance of known same comparative example 1 is compared and how not to be changed, and can fully use in high-frequency circuit.

The length direction of the Esd protection device along above-described embodiment 1 and the face of Width are ground, electric discharge auxiliary electrode is exposed.For the electric discharge auxiliary electrode exposed, carry out microfocus X-ray analysis.As a result, divide BaTiO detected from electric discharge auxiliary electrode portion ₃.

In addition, the length direction of the Esd protection device along above-described embodiment 1 and the face of thickness direction are ground, the section of electric discharge auxiliary electrode is exposed.WDX analysis is carried out to the section of this electric discharge auxiliary electrode.As a result, the Cu particle that oxidized aluminium covers and BaTiO can be confirmed ₃the existence of particle.

(embodiment 2,3)

Except be inserted in ceramic green sheet is coated with conductor thickener ceramic green sheet except, identical with embodiment 1.In embodiment 2, obtain the Esd protection device of the 5th execution mode of Fig. 9, conductor paste material is calcined the conductor obtained and is not electrically connected with outer electrode the most at last.In embodiment 3, obtain the Esd protection device of the 3rd execution mode shown in Fig. 4, conductor is not electrically connected with outer electrode.

As conductor thickener, adopt the material identical with above-mentioned sparking electrode thickener.

Stacked many pieces of ceramic green sheets, wherein comprise and have printed conductor thickener, with the ceramic green sheet making conductor 6 be arranged on the relative beneath portions of first, second sparking electrode 10 μm place.The thickness of the duplexer of master slice is all 0.3mm similarly to Example 1.

Other operation is identical with embodiment 1, obtains the Esd protection device of embodiment 2,3.

In the same manner as the evaluation situation of embodiment 1 and comparative example 1, the discharge ionization voltage of the Esd protection device of the embodiment 2,3 obtained as described above is evaluated.Result as described in Table 6.

[table 6]

Table 6

As shown in Table 6, in embodiment 2,3, work ratio can be made compared with embodiment 1 to raise further.Particularly, when being applied with the low-voltage electrostatic of 2kV, start electric discharge, when being applied with the electrostatic of the voltage of more than 3kV, effectively improve its work ratio.

In addition, also its electrostatic capacitance is measured for embodiment 2,3.As a result, in embodiment 2,3, electrostatic capacitance is 0.08pF and 0.15pF, slightly larger than the electrostatic capacitance of embodiment 1, but electrostatic capacitance is so not high.Thus, also can be suitable for as Esd protection device in high-frequency circuit.

(embodiment 4)

As embodiment 4, make the Esd protection device that the auxiliary electrode that discharges as the second execution mode has space 5c.

In order to form above-mentioned space 5c, in electric discharge auxiliary electrode thickener, crosslinked acrylic resin particle is added into electric discharge auxiliary electrode thickener.The true specific gravity of this crosslinked acrylic resin particle is 1.19, and refractive index is 1.49, average grain diameter D50 is 1.5 μm.

The organic carrier obtained having dissolved 10 % by weight ethyl celluloses in the high dielectric constant material powder DM-1, the metallic M-1 that adopt in embodiment 1, above-mentioned crosslinked acrylic resin particle, terpinol carries out proportioning, mixing in the ratio shown in following table 7, obtains electric discharge auxiliary electrode thickener P-3.

Removing adopts outside above-mentioned electric discharge auxiliary electrode thickener P-3, obtains the Esd protection device of embodiment 4 similarly to Example 1.

In addition, in following table 7, in order to compare, represent the composition of the electric discharge auxiliary electrode thickener P-1 of embodiment 1 in the lump.

[table 7]

Table 7

In the same manner as embodiment, the operating characteristic of the Esd protection device of above-described embodiment 4 is evaluated.Result as described in Table 8.In addition, in table 8, except embodiment 4, also represent the result of embodiment 1 in the lump.

[table 8]

Table 8

As shown in Table 8, according to embodiment 4, under the voltage lower than embodiment 1, work ratio can be improved further.Can this is presumably because by arranging above-mentioned space and carry out partial discharge, thus discharge ionization voltage is reduced.

In addition, the electrostatic capacitance in the Esd protection device of embodiment 4 is 0.07pF.Namely similarly to Example 1, known can effectively for the electrostatic defending in high-frequency circuit.

(embodiment 5 ~ 8)

As the material for the auxiliary electrode thickener of obtaining discharging, prepare the high dielectric constant material powder DM-2 shown in following table 9, the metallic shown in above-mentioned table 10, in terpinol, dissolved 10 % by weight ethyl celluloses and the organic carrier that obtains.In addition, high dielectric constant material powder DM-2 is the BaTiO of 2000 by pulverizing by relative dielectric constant ε r ₃form veneer and obtain.

In addition, the average grain diameter in following table 10 is tried to achieve according to amplifying to multiple metallic the image that 10000 times of shootings obtain with SEM.Namely draw a diagonal in the picture, the long limit of whole metallics crossing with this diagonal is measured.This operation is carried out to 5 images, obtains the mean value on the long limit of metallic.Using this mean value as average grain diameter.

[table 9]

Table 9

High dielectric constant material powder is numbered	Composition	Relative dielectric constant (ε r)	D50(μm)	SSA(m ²/g)
					DM-2	BaTiO ₃	2000	0.5	14

[table 10]

Table 10

Metallic is numbered	Composition	Average grain diameter (μm)
			M-2	Cu	0.10
M-3	Cu	0.30
			M-4	Cu	1.00
M-5	Cu	1.50

High dielectric constant material described in above-mentioned table 9, any one metallic shown in table 10, above-mentioned organic carrier are mixed with the ratio shown in following table 11, obtains electric discharge auxiliary electrode thickener P-4 ~ P-7.

[table 11]

Table 11

Removing adopts outside above-mentioned electric discharge auxiliary electrode thickener P-4 ~ P-7, makes the Esd protection device of embodiment 5 ~ 8 similarly to Example 1.

(evaluation)

For the Esd protection device of the above-mentioned embodiment 5 ~ 8 obtained like that, similarly to Example 1, appraisal rate.

In addition, to the above-mentioned Esd protection device obtained like that from alongst and the face of thickness direction grind, the section of electric discharge auxiliary electrode is exposed.With SEM, the electric discharge auxiliary electrode section that this exposes is taken.Take reflected electron image in addition, be the multiplying power of 10000 times.Measure the long limit of the metallic existed in the image obtained.This operation is carried out to 10 images, obtains the mean value on the long limit of the metallic of mensuration.Using this mean value as average grain diameter.Result is as shown in following table 12.

[table 12]

Table 12

As shown in Table 12, in the Esd protection device of embodiment 5 ~ 8, higher in the applying operating at voltages rate of more than 3kV.In addition, in embodiment 5 ~ 7, confirm also can be driven when being applied with 2kV voltage.Can think, this is the average grain diameter of metallic owing to being present in electric discharge auxiliary electrode is less than 1.5 μm, and electric field when therefore voltage applies between sparking electrode and metallic concentrates localization, easily discharges.

In addition, the LCR tester that the first outer electrode 9 in the Esd protection device of above-described embodiment 5 ~ 8 and the electrostatic capacitance between the second outer electrode 10 are developed by Agilent company measures.Result is as shown in table 13.

[table 13]

Table 13

	Electrostatic capacitance (pF)
		Embodiment 5	0.10
Embodiment 6	0.10
		Embodiment 7	0.10
Embodiment 8	0.10

The electrostatic capacitance of the Esd protection device of known embodiment 5 ~ 8 is less than 0.5pF.Thus, these Esd protection device can be useful in high-frequency circuit.

From alongst grinding with the Esd protection device in the face of above-described embodiment 5 ~ 8 of Width, electric discharge auxiliary electrode is exposed.To the electric discharge auxiliary electrode exposed, carry out microfocus X-ray analysis.As a result, BaTiO is detected from electric discharge auxiliary electrode ₃.

In addition, to the Esd protection device of embodiment 5 ~ 8 from alongst and the face of thickness direction grind, the section of electric discharge auxiliary electrode is exposed.WDX analysis is carried out to the section of this electric discharge auxiliary electrode.As a result, Cu example and BaTiO can be confirmed ₃the existence of particle.

(embodiment 9,10)

Figure 12 is the concise and to the point front cross-sectional view representing the Esd protection device 81 that embodiment 9 prepares.Except the conductor 6 that setting is electrically connected with the second outer electrode 10, Esd protection device 81 has the structure almost identical with the Esd protection device 71 shown in Figure 11.Conductor 6 is arranged on the below of electric discharge auxiliary electrode 5 in substrate 32.This conductor 6, across a part for substrate 32, overlaps with the first and second the discharge opposite segments of auxiliary electrode 3,4 and auxiliary electrode 5 that discharges.

In addition, in embodiment 10, prepare the Esd protection device 91 shown in Figure 13.At this, conductor 6 is electrically connected with the second outer electrode 10.And other structure, Esd protection device 91 is identical with Esd protection device 81.

In the same manner as above-described embodiment 5, make the Esd protection device 81,91 with above-mentioned conductor 6.But, utilize the sparking electrode thickener adopted in embodiment 5 to form conductor 6.

(evaluation)

For the Esd protection device of above-mentioned embodiment 9,10 of specifying like that, evaluate in the same manner as embodiment 5 ~ 8.Result is as shown in following table 14 and table 15.

[table 14]

Table 14

[table 15]

Table 15

	Electrostatic capacitance (pF)
		Embodiment 9	0.15
Embodiment 10	0.12

As shown in Table 14, in the Esd protection device that embodiment 9 and 10 relates to, the work ratio under known low applying voltage significantly improves.That is, in the above embodiments 5, when applying voltage is 2kV, work ratio is the scope more than 10% ~ 50%.

On the other hand, in embodiment 9,2kV execute alive situation under, work ratio more than 90%, also in the scope more than 50% ~ 90% in embodiment 10.Can this is presumably because that conductor 6 plays a role as behind electrode caused.That is, the creeping discharge owing to easily producing when voltage applies via electric discharge auxiliary electrode can be thought.Particularly, in embodiment 9, work ratio when applying 2kV significantly improves.Can this is presumably because that conductor 6 is further improved as the function of behind electrode.It can thus be appreciated that conductor 6 is preferably electrically connected with outer electrode as embodiment 9.

In addition, as shown in Table 15, the electrostatic capacitance of Esd protection device that relates to of embodiment 9 and 10 is less than 0.5pF.Thus, these Esd protection device can be applicable to high-frequency circuit.

Label declaration

1ESD protective device

2 substrates

2a upper surface

2b lower surface

First, second end face of 2c, 2d

3,4 first, second sparking electrodes

3a, 4a side

5 electric discharge auxiliary electrodes

5a metallic

5b high dielectric constant material particle

5c space

6,6A conductor

7,8 first, second resin beds

9,10 first, second outer electrodes

15 electric discharge auxiliary electrodes

31ESD protective device

32 substrates

32e cavity

41,51,61,71ESD protective device

Claims

1. an Esd protection device, is characterized in that, comprising:

Substrate;

First, second sparking electrode, this first, second sparking electrode is arranged on described substrate, relative across gap; And

Electric discharge auxiliary electrode, this electric discharge auxiliary electrode is set to connect described first sparking electrode, described second sparking electrode, promotes the electric discharge between first, second sparking electrode described;

Described electric discharge auxiliary electrode by

I () comprises metal and relative dielectric constant the first composite material higher than the high dielectric constant material of described substrate;

(ii) metal and relative dielectric constant that are covered by the material without conductivity is comprised higher than the second composite material of the high dielectric constant material of described substrate;

(iii) comprise covered by the material without conductivity metal, semiconductor particle and relative dielectric constant be higher than the 3rd composite material of the described high dielectric constant material of described substrate; And

(iv) advanced low-k materials of the relative dielectric constant of below the metal covered by the material without conductivity, the relative dielectric constant with described substrate and relative dielectric constant the 4th composite material higher than the described high dielectric constant material of described substrate is comprised

At least one composite material selected in the group formed is formed,

Described electric discharge auxiliary electrode comprises space.

2. Esd protection device as claimed in claim 1, is characterized in that,

The relative dielectric constant of described high dielectric constant material is more than the twice of the relative dielectric constant of described substrate, and less than 10000.

3. Esd protection device as claimed in claim 1, is characterized in that,

Relative dielectric constant is positioned at described gap lower than the low-k part of described substrate.

4. Esd protection device as claimed in claim 3, is characterized in that,

Described low-k part is cavity.

5. Esd protection device as claimed in claim 3, is characterized in that,

Described low-k part is formed by the solid material of relative dielectric constant lower than substrate.

6. Esd protection device as claimed in claim 5, is characterized in that,

Described relative dielectric constant is resin lower than the solid material of substrate.

7. the Esd protection device according to any one of claim 1 ~ 6, is characterized in that,

Also comprise conductor, this conductor is set to overlap with the gap between first, second sparking electrode described via a part for described substrate.

8. the Esd protection device according to any one of claim 1 ~ 6, is characterized in that,

Also comprise first, second outer electrode, this first, second outer electrode is arranged on the substrate, is electrically connected respectively with first, second sparking electrode described,

Described conductor is electrically connected with the described first or second outer electrode.

9. the Esd protection device according to any one of claim 1 ~ 6, is characterized in that,

Described conductor is suspended conductor.

10. Esd protection device as claimed in claim 7, is characterized in that,

Described conductor comprises: metal, and compared with described substrate the material of high-k.

11. Esd protection device as claimed in claim 8, is characterized in that,

12. Esd protection device as claimed in claim 9, is characterized in that,

13. Esd protection device according to any one of claim 1 ~ 6, is characterized in that,

First, second sparking electrode described is arranged on the outer surface of described substrate.

14. Esd protection device according to any one of claim 1 ~ 6, is characterized in that,

First, second sparking electrode described is arranged in described substrate, and described gap is positioned at described substrate.

15. Esd protection device as claimed in claim 1, is characterized in that,

Described metal in described first composite material is average grain diameter more than 0.3 μm, the metallic of less than 1.5 μm.

16. Esd protection device according to any one of claim 1 ~ 6, is characterized in that,

Described high dielectric constant material is barium titanate ceramics.

17. Esd protection device according to any one of claim 1 ~ 6, is characterized in that,

Minimum discharge ionization voltage is below 2kV.