JP2016219716A - Transient voltage protection element, resin composition and protective member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve protection for a portable apparatus from a transient voltage, without impeding miniaturization of the portable apparatus.SOLUTION: A protection part 21 is placed between the input side terminal T3 of an IC1, and a ground terminal T2, and is molded of an insulation material with varistor function. A capacitor part 22 is placed between the ground terminal T2 of the protection part 21, and the ground terminal T1 of the IC1, and functions as the capacitor for dam. The energy generated from the discharge side and absorbed by the protection part 21 flows into the capacitor part 22. The absorption energy is stored temporarily in the capacitor part 22, and then discharged gradually.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a transient voltage protection element, a resin composition, and a protection member.

  Conventionally, a transient voltage protection element has been used to protect a circuit such as an IC (Integrated Circuit) incorporated in a circuit board from a transient voltage due to static electricity or the like (see Patent Document 1).

FIG. 1 is a diagram showing a conventional circuit configuration for protection from transient voltage.
The protection target IC 1 performs predetermined signal processing on the input signal and outputs the signal after the signal processing to the output target 2 as an output signal.
The transient voltage protection element 3 includes a Zener diode, a varistor, a gas arrester, and the like, and is connected between the input terminal of the IC 1 to be protected and the ground (GND).
The transient voltage protection element 3 functions as a very large insulation resistance under normal conditions and does not affect the input / output signals of the IC 1.
On the other hand, when a transient voltage is generated from the discharge side P (transient voltage generation side P) due to ESD (electrostatic discharge) from a human body or the like, the transient voltage protection element 3 has several Ω in the order of several ns. It drops to the following low impedance, and the current generated by the transient voltage flows to ground. That is, the transient voltage protection element 3 exhibits a transient voltage absorption function.

  Here, the circuit shown in FIG. 1 is a configuration for a stationary electronic device. That is, it is assumed that the ground end of the transient voltage protection element 3 is grounded to the ground or connected to the ground on the discharge side P (transient voltage generation side P). Under this premise, as shown in FIG. 1, since a path through which the feedback current FI (ESD energy) flows from the circuit side C to the discharge side P is secured, the IC 1 can be sufficiently protected.

JP 2001-267494 A

  However, recent electronic devices are mainly portable devices such as smartphones and tablet terminals. In the portable device, since the ground on the circuit side to be protected is in an electrically floating state, there is no return path for ESD energy from the human body or the like. For this reason, in a portable device, a sufficient transient voltage absorbing function cannot be exhibited even if a conventional transient voltage protection element is simply connected as in the stationary type.

FIG. 2 is a diagram showing a conventional circuit configuration for protection from transient voltage, and is a diagram showing a circuit configuration when applied to a portable device.
The difference between FIG. 1 and FIG. 2 is that the ground of the transient voltage protection element 3 (the ground of the IC 1 to be protected) is separated from the ground of the discharge side P (transient voltage generation side P).
That is, in the portable device, as shown in FIG. 2, since the ground of the IC 1 and the transient voltage protection element 3 is in an electrically floating state, the feedback path to the discharge side (the feedback current FI of FIG. 1 flows). Route) is lost. As a result, the ESD energy absorbed by the transient voltage protection element 3 flows into a low potential (such as a ground terminal) on the circuit side as a leakage current MI. As a result, a large potential difference is generated, and the circuit of the portable device including the IC 1 may be destroyed.

  For this reason, it is required to realize a technique that can protect portable devices from transient voltages due to static electricity or the like. Furthermore, miniaturization and thinning are required in terms of portable devices.

  The present invention has been made in view of such a situation, and an object of the present invention is to realize protection from a transient voltage for a portable device without hindering miniaturization of the portable device.

To achieve the above object, a transient voltage protection element according to an aspect of the present invention is provided.
A protective part which is arranged between the terminal of the circuit to be protected and the ground, and exhibits non-linearity in which the voltage-current characteristic does not follow Ohm's law;
A capacitor unit disposed between the ground of the protection unit and the ground of the protection target circuit;
It is characterized by providing.

  The protection unit may be a member connected to one of the two electrodes of the capacitor unit.

  One embodiment of the present invention is a resin composition, which includes a thermosetting resin and semiconductor ceramic particles, and the semiconductor ceramic particles include a grain boundary part and a plurality of crystals separated by the grain boundary part. And the cured product of the resin composition exhibits non-linearity in which the voltage-current characteristics do not follow Ohm's law, and is a protective part disposed between the terminal of the circuit to be protected and the ground. Among the transient voltage protection elements including a capacitor portion disposed between the protection portion ground and the protection target circuit ground, the resin composition is used for molding the protection portion.

  One aspect of the present invention is a protective member that is molded from a resin composition and protects a transient voltage with respect to a circuit to be protected, and the resin composition includes a thermosetting resin and semiconductor ceramic particles, The semiconductor ceramic particle has a grain boundary part and a plurality of crystal parts separated by the grain boundary part, and the protective member exhibits nonlinearity in which voltage-current characteristics do not follow Ohm's law, It is arrange | positioned between the terminal of the said protection target circuit, and ground, The said ground is a protection member connected also to the other end of the capacitor | condenser by which one end is connected with the ground of the said protection target circuit.

  ADVANTAGE OF THE INVENTION According to this invention, the protection from the transient voltage with respect to a portable apparatus is realizable, without preventing the miniaturization of a portable apparatus.

It is a figure which shows the conventional circuit structure for protecting from a transient voltage. It is a figure which shows the conventional circuit structure for protecting from a transient voltage, Comprising: It is a figure which shows the circuit structure in the case of applying to a portable apparatus. It is a figure which shows an example of the circuit structure for protecting a portable apparatus from a transient voltage using the transient voltage protection element which concerns on one Embodiment of this invention. It is a figure which shows the structural example of the transient voltage protection element which concerns on one Embodiment of this invention. It is a schematic diagram which shows a mode that the transient voltage protection element of FIG. 4 was mounted in boards | substrates, such as an electronic device. It is a structural example of the transient voltage protection element which concerns on one Embodiment of this invention, Comprising: It is a figure which shows the example different from FIG. It is a figure which shows the example of an external appearance structure of the transient voltage protection element which has the internal structure of FIG. It is a circuit diagram of the arc-extinguishing apparatus to which the pressure protection element is applied. It is an expanded sectional view of the semiconductor ceramic particle concerning this embodiment. It is a schematic diagram which shows an example of the structure which concerns on this embodiment. It is a schematic diagram which shows an example of the structure which concerns on this embodiment.

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

FIG. 3 is a diagram illustrating an example of a circuit configuration for protecting a portable device from a transient voltage using the transient voltage protection element according to the embodiment of the present invention.
The transient voltage protection element 10 according to the present embodiment includes a protection unit 21 having the same function as a conventional transient voltage protection element, and a capacitor unit 22 that functions as a dam capacity described later.

  In FIG. 3, an IC 1 is provided as a protection target circuit in the same manner as in the conventional FIG. 1 and FIG. However, this is only an example when the circuit to be protected is made the same as the conventional one in order to facilitate the explanation of the present invention. That is, the transient voltage protection element 10 according to the present embodiment can connect not only the IC 1 but also any circuit that may be damaged by the transient voltage as a protection target circuit.

The protection unit 21 is disposed between the input terminal T3 of the IC1 (circuit to be protected) and the ground terminal T2, and is a high-voltage protection member that exhibits non-linearity in which the voltage-current characteristics do not follow Ohm's law. Molded. In the present specification, “a high-voltage protection member exhibiting non-linearity in which voltage-current characteristics do not follow Ohm's law” is also referred to as “insulating material with varistor function”.
The insulating material with a varistor function functions as an insulating material until a voltage equal to or lower than a predetermined voltage is applied, but functions as a conductive material when a voltage exceeding the predetermined voltage is applied. Details of the insulating material with a varistor function will be described later with reference to FIGS.
Here, “connected” means electrically connected when a voltage exceeding the predetermined voltage is applied.

  The capacitor unit 22 is disposed between the ground terminal T2 of the protection unit 21 and the ground terminal T1 of IC1 (protection target circuit), and functions as a dam capacitor. The dam capacity will be described below.

  The capacitance of the capacitor unit 22 (dam capacity) may be, for example, not less than a value obtained by dividing the product of the discharge side capacity and the voltage by the voltage set for the dam capacity.

Each impedance of the input and output of the IC 1 is extremely higher than several Ω in the operating state of the protection unit 21 of the transient voltage protection element 10.
For this reason, the energy generated from the discharge side P and absorbed by the protection unit 21 surely flows into the capacitor unit 22 (dam capacity). The absorbed energy is temporarily stored in the capacitor unit 22 (dam capacity) and then gradually discharged.
As a result, generation of a high potential on the circuit side C can be suppressed, so that protection from a transient voltage for the portable device can be enhanced.

Here, instead of the protection part 21 of the transient voltage protection element 10, a conventional transient voltage protection element 3 (FIG. 1 or 2) such as a varistor is adopted, and the capacitor part 22 of the transient voltage protection element 10 is provided. Instead, even if a conventional capacitor element is employed, a circuit configuration equivalent to FIG. 3 can be realized. That is, the protection from the transient voltage for the portable device itself becomes possible.
However, mounting two elements of the conventional transient voltage protection element 3 and the conventional capacitor element on the portable device hinders downsizing of the portable device.
In other words, in order to protect the portable device from the transient voltage, the conventional transient voltage protection element 3 is not sufficient, and a dam capacity is required. Adding a capacitor element for this dam capacity means increasing the number of parts of the portable device, which hinders the miniaturization of the portable device.
On the other hand, in the present embodiment, the same effect as the case where two elements of the conventional transient voltage protection element 3 and the conventional capacitor element are mounted only by mounting one element called the transient voltage protection element 10. That is, the portable device can be protected from a transient voltage. That is, since it is not necessary to increase the number of parts of the portable device, the portable device can be sufficiently protected from the transient voltage without hindering the downsizing of the portable device.
Furthermore, since it is not necessary to form the protection part 21 and the capacitor part 22 constituting the transient voltage protection element 10 in a special shape, the manufacture of the protection part 21 and the capacitor part 22 is facilitated, and the work of incorporating and connecting them becomes easy. . As a result, the entire transient voltage protection element 10 can be easily manufactured, and the manufacturing cost can be reduced.
On the other hand, even if it is necessary to make the capacitor portion 22 into a special shape according to various specifications and demands, the use of an insulating material with a varistor function that is excellent in formability facilitates the work of incorporating and connecting them. . In other words, since an insulating material with a varistor function that is excellent in formability can be used, various design requirements can be met, and as a result, the design flexibility of the transient voltage protection element 10 is increased.
In other words, since the transient voltage protection element 10 is completed simply by connecting the protection part 21 to the capacitor part 22, the entire transient voltage protection element 10 can be easily manufactured, and the manufacturing cost is reduced. Is also possible.
Here, the capacitor portion 22 can have various shapes according to various specifications and requests, but since an insulating material with a varistor function having excellent formability can be used, it is suitable for any shape. The protection part 21 can be manufactured easily. As a result, the degree of freedom in designing the transient voltage protection element 10 is increased.

(Transient voltage protection element structure)
FIG. 4 is a diagram illustrating a structure example of the transient voltage protection element 10 according to the embodiment of the present invention. Specifically, FIG. 4A is a perspective view showing an external configuration of the transient voltage protection element 10. However, the internal structure of the transient voltage protection element 10 is also shown in a part of FIG. FIG. 4B is a cross-sectional view showing the internal structure of the transient voltage protection element 10.

In FIG. 4, the capacitor portion 22 of the transient voltage protection element 10 has the same configuration as that of the multilayer ceramic chip capacitor.
That is, the capacitor portion 22 has a configuration in which ceramic dielectrics 31 and internal electrodes 32 are alternately laminated in multiple layers, and external electrodes 33 are connected to both side surfaces thereof. That is, since the internal electrodes 32 are alternately connected to the left and right external electrodes 33, the capacitor unit 22 has a configuration equivalent to a parallel junction of a plurality of capacitors.
The transient voltage protection element 10 is configured by connecting the protection unit 21 to one of the two external electrodes 33 of the capacitor unit 22 (corresponding to one end of the capacitor).
For example, the transient voltage protection element 10 may have a size of 10 mm × 10 mm. The size is merely an example, and various types of transient voltage protection elements 10 can be provided according to specifications and the like.

(Transient voltage protection device manufacturing method)
The manufacturing method of the capacitor part 22 itself is basically the same as that of a conventional multilayer ceramic chip capacitor, and the description thereof is omitted here.
For example, the rectangular parallelepiped protective portion 21 is manufactured using an insulating material with a varistor function.
The transient voltage protection element 10 is manufactured by bonding the side surface of the protection unit 21 and one external electrode 33 of the capacitor unit 22.

FIG. 5 is a schematic diagram showing a state in which the transient voltage protection element 10 of FIG. 4 is mounted on a substrate 51 such as an electronic device.
Although it is not essential to mount the IC1 (not shown) (FIG. 3) on the substrate 51, it is assumed that printed wiring corresponding to the terminals T1 to T3 in FIG. 3 is provided.
As shown in FIG. 5, by mounting the transient voltage protection element 10 on the substrate 51, the protection unit 21 is arranged between the input terminal T <b> 3 (not shown) of the IC <b> 1 (circuit to be protected) and the ground terminal T <b> 2. In addition, the capacitor unit 22 is disposed between the grounding terminal T2 of the protection unit 21 and the grounding terminal T1 of IC1 (a circuit to be protected).

  Here, the transient voltage protection element 10 to which the present invention is applied is not limited to the above-described embodiments of FIG. 4 and FIG. 5, and modifications, improvements, etc. within a range in which the object of the present invention can be achieved. It is included in the invention.

For example, the transient voltage protection element 10 can take the structure shown in FIG.
FIG. 6 is a structural example of the transient voltage protection element 10 according to an embodiment of the present invention, and is a diagram showing an example different from FIG. Specifically, FIG. 6A is a perspective view showing the internal configuration of the transient voltage protection element 10. FIG. 6B is a side sectional view showing the internal structure of the transient voltage protection element 10.
FIG. 7 is a diagram showing an external configuration example of the transient voltage protection element 10 having the internal structure of FIG.

In FIG. 6, the capacitor part 22 of the transient voltage protection element 10 has the same configuration as a conventional single plate capacitor.
That is, the capacitor unit 22 has a configuration in which the electrode 61, the dielectric 62, and the electrode 63 are stacked, and lead wires are connected to the electrode 61 and the electrode 63, respectively.
Assuming that the lead wire of the electrode 61 is connected to the ground end T1 of the circuit to be protected and the lead wire of the electrode 63 is connected to the ground end T2 of the protection unit 21, the opposite of the electrode 63 from the dielectric 62 side. The protection part 21 is laminated on the surface on the side, and the lead wire is connected to the protection part 21, whereby the transient voltage protection element 10 is configured. The lead wire of the protection part 21 is connected to the terminal T3 on the input side of the circuit to be protected.

(Transient voltage protection device manufacturing method)
The manufacturing method of the capacitor unit 22 itself is basically the same as that of a conventional single plate capacitor, and therefore the description thereof is omitted here.
For example, the cylindrical protection part 21 is manufactured using an insulating material with a varistor function.
The transient voltage protection element 10 is manufactured by bonding the bottom surface of the protection unit 21 and the surface of the electrode 63 of the capacitor unit 22 opposite to the dielectric 62 side.

Moreover, the following resin composition is sufficient for the protection part molded from the insulating material with varistor function.
That is, the resin composition according to the present invention includes a thermosetting resin, and semiconductor ceramic particles having a grain boundary part and a plurality of crystal parts separated by the grain boundary part, and the cured product has voltage-current characteristics. Is a resin composition exhibiting non-linearity that does not follow Ohm's law, a protective part disposed between a terminal of the circuit to be protected and the ground, a ground of the protective part, and a ground of the circuit to be protected Among the transient voltage protection elements including the capacitor portion disposed between the two, the protection portion is used to be molded. The resin composition corresponds to the insulating material with a varistor function shown as an example above.

By using the resin composition adopting such a configuration, it becomes possible to provide a protective portion in the transient voltage protection element with a high yield. Therefore, as in the prior art, the transient voltage protection element and the capacitor element are arranged in the circuit. As a result, it is not necessary to increase the number of parts of the portable device, so that the portable device can be protected from the transient voltage without hindering the downsizing of the portable device. be able to.

  Here, the non-linearity (varistor characteristic) in which the voltage-current characteristic does not follow Ohm's law, which the structure obtained by the manufacturing method according to the present embodiment has, is an electronic component having at least two electrode terminals. On the other hand, when a voltage that gradually increases is applied, the current that flows through an overvoltage protection element generally called a varistor element increases nonlinearly. In the present embodiment, the structure having the varistor characteristics is specifically a structure that is mounted on an electronic component having a first terminal and a second terminal, and the structure is attached to the electronic component. When mounted, if the voltage between the first terminal and the second terminal is less than the withstand voltage of the device, it exhibits insulation and the voltage between the first terminal and the second terminal When the voltage is higher than the driving voltage of the device, it indicates the one showing conductivity. Here, the electronic component corresponds to a transient voltage protection element, and the first terminal and the second terminal correspond to the terminal of the circuit to be protected and the ground of the protection unit. In addition, the voltage which the characteristic which the structure which concerns on this embodiment has is converted from insulation to electroconductivity as mentioned above, or the voltage converted from electroconductivity to insulation is hereafter called a varistor voltage. .

  Hereinafter, the resin composition according to the present embodiment will be described in detail.

  Conventionally, as described in the section of the problem to be solved by the present invention, as a countermeasure against transient voltage, it has been usual to adopt a configuration in which a transient voltage protection element and a capacitor element are arranged in a circuit. Therefore, conventionally, it has been necessary to secure a space for arranging two elements, that is, a transient voltage protection element and a capacitor element. Therefore, there has been a limit to realizing protection from the transient voltage for the portable device without hindering the miniaturization of the portable device. In view of such circumstances, the present inventor can realize protection from the transient voltage for the portable device without hindering the miniaturization of the portable device, if the protection unit can be provided in the transient voltage protection element. I thought. Specifically, the inventor can realize a member that can be disposed between the terminal of the circuit to be protected and the ground of the protection unit, for example, a film-like member and exhibits varistor characteristics. It was found that it is effective as a design guideline.

  However, in order to produce a member (structure) exhibiting the above-described varistor characteristics, it was necessary to produce a resin composition having the following three characteristics. The first characteristic required for the resin composition can control the shape of the member so that it can correspond to the shape of the electrode terminal mounted in the transient voltage protection element that is the target of use of the member exhibiting varistor characteristics. Excellent moldability. The second characteristic required for the resin composition is the function of the sealing material used to protect the electrode terminal in the conventional electronic component, that is, heat resistance, temperature cycle resistance, insulation reliability. The required characteristics such as durability, adhesion, and dimensional stability are maintained. The 3rd characteristic requested | required of the said resin composition is that the said resin composition can express sufficient varistor characteristic.

  In view of such circumstances, the present inventor has intensively studied a design guideline for producing a resin material that satisfies the above-described three required characteristics. As a result, the semiconductor ceramic particles 100 having varistor characteristics (see FIG. 9), When blended in the resin composition, the transient voltage protection element is provided with a protective part or a structure having a function of protecting the transient voltage protection element from an external load of stress applied from the external environment. The knowledge that it was possible to produce the member which can be manufactured with a sufficient yield was obtained. In addition, from the viewpoint of satisfying the first characteristic described above, that is, from the viewpoint of realizing sufficient formability, the present inventor has employed a compression molding method or a transfer molding as a method for producing a member exhibiting the above varistor characteristics. We also found it desirable to adopt the law. Therefore, the present resin composition is desirably processed into a granular, tablet or sheet form.

<Thermosetting resin>
Specific examples of the thermosetting resin contained in the resin composition according to the present invention include novolak type phenol resins such as phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, and triazine skeleton-containing phenol novolak resin; Phenolic resins such as phenolic resins, tung oil, linseed oil, walnut oil, and other resol type phenolic resins such as oil-modified resol phenolic resins; bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol E Type epoxy resin, bisphenol M type epoxy resin, bisphenol P type epoxy resin, bisphenol Z type epoxy resin and other bisphenol type epoxy resins; phenol novolac type epoxy resin, Novolec type epoxy resins such as resole novolac type epoxy resins; biphenyl type epoxy resins, biphenyl aralkyl type epoxy resins, arylalkylene type epoxy resins, naphthalene type epoxy resins, anthracene type epoxy resins, phenoxy type epoxy resins, dicyclopentadiene type epoxy resins , Epoxy resin such as norbornene type epoxy resin, adamantane type epoxy resin, fluorene type epoxy resin; resin having triazine ring such as urea (urea) resin, melamine resin; unsaturated polyester resin; maleimide resin such as bismaleimide compound; polyurethane Resin; diallyl phthalate resin; silicone resin; benzoxazine resin; cyanate ester resin; polyimide resin; polyamideimide resin; Resin, a novolac type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, bisphenol type cyanate resin such as tetramethyl bisphenol F type cyanate resins. One of these may be used alone, two or more having different weight average molecular weights may be used in combination, and one or two or more thereof and a prepolymer thereof may be used in combination.

  The content of the thermosetting resin is preferably 1% by mass or more and 38% by mass or less, and more preferably 1.5% by mass or more and 35% by mass or less with respect to the total amount of the resin composition according to the present invention. Yes, more preferably 2% by mass or more and 30% by mass or less, and most preferably 3% by mass or more and 25% by mass or less. By making content of a thermosetting resin more than the said numerical range, the fluidity | liquidity of a resin composition can be improved. In addition, by making the content of the thermosetting resin not more than the above numerical range, the heat dissipating property of the resin composition can be improved, and the varistor characteristics provided in the structure composed of the resin composition according to the present invention can be improved. It is possible to improve.

  As the thermosetting resin contained in the resin composition according to the present invention, an epoxy resin is preferably used. As said epoxy resin, it is possible to use the monomer, oligomer, and polymer in general which have 2 or more of epoxy groups in 1 molecule irrespective of the molecular weight and molecular structure. Specific examples of such epoxy resins include biphenyl type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, stilbene type epoxy resins, hydroquinone type epoxy resins and the like; cresol novolac type epoxy resins, Novolak type epoxy resins such as phenol novolac type epoxy resin and naphthol novolak type epoxy resin; Phenol aralkyl type epoxy such as phenylene skeleton-containing phenol aralkyl type epoxy resin, biphenylene skeleton containing phenol aralkyl type epoxy resin, phenylene skeleton containing naphthol aralkyl type epoxy resin Resin; Trifunctional epoxy resin such as triphenolmethane type epoxy resin and alkyl-modified triphenolmethane type epoxy resin; Examples include modified phenolic epoxy resins such as diene-modified phenolic epoxy resins and terpene-modified phenolic epoxy resins; and heterocyclic-containing epoxy resins such as triazine nucleus-containing epoxy resins. These can be used alone or in two types. A combination of the above may also be used.

The present resin composition may contain a release agent. By doing so, a member (structure 300) exhibiting varistor characteristics can be manufactured with higher yield. The reason for this is as follows. As described above, the present resin composition is preferably assumed to be used as a raw material for producing a member (structure 300) exhibiting varistor characteristics by a compression molding method or a transfer molding method. When the compression molding method or the transfer molding method is employed, the member (structure 300) is manufactured using a resin mold. In this case, after molding the member (structure 300) using the resin composition, it is necessary to release the molded product from the mold. And when the mold release force at the time of releasing a molding from a molding die becomes strong, there exists a tendency for the inconvenience that the obtained molding is damaged easily arises. Therefore, when a resin composition containing a release agent is used, it is possible to suppress the above-described inconvenience, and as a result, a member (structure 300) exhibiting varistor characteristics is manufactured with high yield. It becomes possible.

  Specific examples of the release agent according to this embodiment include natural wax, synthetic wax, higher fatty acid or metal salt thereof, paraffin, polyethylene oxide and the like. The content of the release agent is preferably 0.01% by mass or more and 1% by mass or less, and more preferably 0.03% by mass or more and 0.8% by mass or less, based on the total amount of the resin composition. .

The resin material 200 according to the present invention (see FIGS. 9 and 10) may contain a curing agent. The curing agent only needs to be cured by reacting with a thermosetting resin. Specific examples of curing agents that can be used when an epoxy resin is used as the thermosetting resin include ethylenediamine and trimethylene. C2-C20 linear aliphatic diamine such as diamine, tetramethylenediamine, hexamethylenediamine, metaphenylenediamine, paraphenylenediamine, paraxylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl Propane, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfone, 4,4′-diaminodicyclohexane, bis (4-aminophenyl) phenylmethane, 1,5-diaminonaphthalene, metaxylenediamine, para Xylenediamine, 1,1-bis (4-aminophenyl) Nyl) aminos such as cyclohexane and dicyanodiamide; resol type phenol resins such as aniline-modified resole resin and dimethyl ether resole resin; novolac type phenol resins such as phenol novolac resin, cresol novolac resin, tert-butylphenol novolac resin, nonylphenol novolac resin; Phenol aralkyl resins such as phenylene skeleton-containing phenol aralkyl resins and biphenylene skeleton-containing phenol aralkyl resins; phenol resins having a condensed polycyclic structure such as naphthalene skeleton and anthracene skeleton; polyoxystyrenes such as polyparaoxystyrene; hexahydrophthalic anhydride ( HHPA), alicyclic acid anhydrides such as methyltetrahydrophthalic anhydride (MTHPA), trimellitic anhydride (TMA), Acid anhydrides including aromatic acid anhydrides such as pyromellitic anhydride (PMDA) and benzophenone tetracarboxylic acid (BTDA); polymercaptan compounds such as polysulfides, thioesters, thioethers; isocyanate prepolymers, blocked isocyanates, etc. Isocyanate compounds; organic acids such as carboxylic acid-containing polyester resins. These may be used alone or in combination of two or more. Among them, from the viewpoint of improving the moisture resistance and reliability of the structure 300, a compound having at least two phenolic hydroxyl groups in one molecule is preferable, and specific examples thereof include phenol novolac resin, cresol novolac resin, tert-butylphenol. Novolak type phenol resins such as novolak resins and nonylphenol novolak resins; resol type phenol resins; polyoxystyrenes such as polyparaoxystyrene; phenylene skeleton-containing phenol aralkyl resins, biphenylene skeleton-containing phenol aralkyl resins, phenylene skeleton-containing naphthol aralkyl type phenol resins Is mentioned.

The resin material 200 included in the resin composition may contain a curing accelerator. The curing accelerator is not particularly limited as long as it accelerates the curing reaction between a functional group such as an epoxy group and the curing agent. Specific examples thereof include 1,8-diazabicyclo (5,4,0) undecene- Diazabicycloalkenes and derivatives thereof such as 7; amine compounds such as tributylamine and benzyldimethylamine; imidazole compounds such as 2-methylimidazole; organic phosphines such as triphenylphosphine and methyldiphenylphosphine; tetraphenylphosphonium tetra Phenylborate, tetraphenylphosphonium / tetrabenzoic acid borate, tetraphenylphosphonium / tetranaphthoic acid borate, tetraphenylphosphonium / tetranaphthoyloxyborate, tetraphenylphosphonium / tetranaphthyloxyborate Triphenylphosphine and the like that adduct benzoquinone; tetra-substituted phosphonium tetra-substituted borate over bets like. These may be used alone or in combination of two or more.

  In addition to the above-described components, the resin material 200 contained in the resin composition includes a coupling agent such as γ-glycidoxypropyltrimethoxysilane; a colorant such as carbon black; Mold release agents such as waxes, synthetic waxes, higher fatty acids or metal salts thereof, paraffin and polyethylene oxide; low stress agents such as silicone oil and silicone rubber; ion scavengers such as hydrotalcite; flame retardants such as aluminum hydroxide; You may mix | blend various additives, such as antioxidant.

<Semiconductor ceramic particles>
FIG. 8 is an enlarged cross-sectional view of semiconductor ceramic particles according to the present embodiment.
As shown in FIG. 8, the semiconductor ceramic particle 100 according to the present embodiment is a particle having a grain boundary part 120 and a plurality of crystal parts 110 separated by the grain boundary part 120. In other words, in the semiconductor ceramic particle 100 according to the present embodiment, a plurality of crystals composed of the grain boundary part 120 and two or more crystal parts 110 arranged so as to be separated from each other via the grain boundary part 120 are aggregated. It can be said that it is a particle. When a voltage lower than the varistor voltage is applied to the particle, the semiconductor ceramic particle 100 does not pass a current because the grain boundary 120 acts as a resistance, but a voltage higher than the varistor voltage is applied. In some cases, the particles have a characteristic that a tunnel effect occurs and current flows as shown by arrows in FIG. In addition, about the member provided with the varistor characteristic like the semiconductor ceramic particle 100 according to the present embodiment, it is included in a withstand voltage protection element (varistor element or the like) to be mounted on the same circuit together with the electronic element in the conventional electronic component. It was. However, a method for producing a member made of the resin composition containing the semiconductor ceramic particles 100 satisfying the following two required characteristics with high yield has not been reported so far. The first required characteristic described above is that it can be provided inside the electronic element itself mounted in the circuit mounted in the electronic component. The second required characteristic described above has a function of protecting the electronic element from stress applied from the external environment in addition to overvoltage such as static electricity when the member is provided inside the electronic element itself. That is.

  The average particle diameter D50 of the semiconductor ceramic particle 100 is, for example, 0.01 μm or more and 150 μm or less, preferably 0.1 μm or more and 120 μm or less, more preferably 1 μm or more and 90 μm or less, and particularly preferably. It is 5 μm or more and 60 μm or less. By doing so, it becomes possible to develop varistor characteristics without depending on the shape of the structure 300 formed of the resin composition including the semiconductor ceramic particles 100.

  The semiconductor ceramic particles 100 are preferably spherical particles. Thereby, it is possible to easily control the varistor characteristics.

In the semiconductor ceramic particle 100, the crystal part 110 is preferably formed of a material including at least one selected from the group consisting of zinc oxide, silicon carbide, strontium titanate, and barium titanate. Especially, the material which contains zinc oxide as a main component is preferable from a viewpoint of improving the nonlinear coefficient and energy tolerance of the semiconductor ceramic particle 100 itself. Since a material containing silicon carbide as a main component has a high dielectric breakdown voltage, it is suitable when the varistor voltage is set to a high voltage. A material containing strontium titanate as a main component is preferable in terms of absorption and suppression of high voltage / high frequency noise.

  In the semiconductor ceramic particle 100, the grain boundary part 120 is preferably formed of a material containing at least one selected from the group consisting of bismuth, praseodymium, antimony, manganese, cobalt and nickel, or a compound thereof. Among these, the grain boundary portion 120 is preferably formed of a material containing at least one selected from the group consisting of bismuth, praseodymium, and these compounds from the viewpoint of good non-linear resistance characteristics. . Examples of these compounds include oxides, nitrides, organic compounds, and other inorganic compounds, but oxides are preferable from the viewpoint of satisfactorily expressing varistor characteristics.

  The content of the semiconductor ceramic particles 100 is preferably 60% by mass or more and 97% by mass or less, and more preferably 70% by mass with respect to the total amount of the resin composition, from the viewpoint of surely expressing the varistor characteristics of the structure 300. It is not less than 95% by mass and particularly preferably not less than 75% by mass and not more than 95% by mass. By controlling the content of the semiconductor ceramic particles 100 to be within the above numerical range, the semiconductor ceramic particles are arranged such that a plurality of particles are in contact with each other between the two electrode terminals 130 as shown in the schematic diagram of FIG. A structure 300 filled with 100 can be realized. That is, when the content of the semiconductor ceramic particles 100 is controlled to be within the above numerical range, the varistor characteristics of the structure can be surely expressed.

  The resin composition preferably contains conductive particles. Thus, when a high voltage exceeding the varistor voltage is applied to the transient voltage protection element including the structure 300 formed of the resin composition, the electrical conductivity of the structure 300 is further increased. It can be good. Specifically, as shown in FIG. 10, the conductive particles 150 can enter the gap region between the plurality of semiconductor ceramic particles 100 arranged so as to fill the space between the two electrode terminals 130. Thereby, the varistor characteristic of the structure 300 can be further improved.

  The content of the conductive particles 150 is preferably 1% by mass or more and 20% by mass or less, more preferably 2% by mass with respect to the total amount of the resin composition, from the viewpoint of surely expressing the varistor characteristics of the structure 300. The content is from 15% to 15% by mass, and most preferably from 2% to 10% by mass. By controlling the content of the conductive particles 150 to be within the above numerical range, a plurality of semiconductor ceramic particles 100 arranged so as to fill the space between the two electrode terminals 130 as shown in the schematic diagram of FIG. It becomes possible to allow the conductive particles 150 to enter the gap region evenly.

  The average particle diameter D50 of the conductive particles 150 is, for example, 0.01 μm or more and 50 μm or less, preferably 0.02 μm or more and 40 μm or less, more preferably, from the viewpoint of surely expressing the varistor characteristics of the structure. Is 0.05 μm or more and 30 μm or less, and particularly preferably 0.1 μm or more and 20 μm or less.

Specific examples of the material forming the conductive particles 150 are selected from the group consisting of nickel, carbon black, aluminum, silver, gold, copper, graphite, zinc, iron, stainless steel, tin, brass, and alloys thereof. And a semiconductive material selected from the group consisting of zinc oxide, silicon carbide, strontium titanate, and barium titanate.

  Moreover, it is preferable that the magnitude | size of the semiconductor ceramic particle 100 contained in this resin composition and the electrically-conductive particle 150 satisfy | fills the following conditions. Specifically, when the average particle diameter D50 of the semiconductor ceramic particles 100 is X and the average particle diameter D50 of the conductive particles 150 is Y, the value of Y / X is preferably 0.05 or more and less than 1. More preferably, it is 0.1 or more and 0.8 or less. By doing so, as in the schematic diagram shown in FIG. 10, the conductive particles 150 can easily enter the gap regions between the plurality of semiconductor ceramic particles 100 arranged so as to fill the gap between the two electrode terminals 130.

  The resin composition according to the present embodiment employs a configuration including semiconductor ceramic particles exhibiting a specific amount of varistor characteristics together with a thermosetting resin. By using the resin composition adopting such a configuration, the transient voltage protection element has a function of protecting the transient voltage protection element from an external load due to stress applied from the external environment, or by providing a protective part. Since the configuration can be provided, it is not necessary to arrange the transient voltage protection element and the capacitor element in the circuit as in the case of the conventional electronic parts, and as a result, the number of parts of the portable device is increased. Since it becomes unnecessary, protection from the transient voltage of the portable device can be realized without hindering downsizing of the portable device.

  Hereinafter, a method for producing a protective part (hereinafter, also referred to as “member showing varistor characteristics” and / or “structure 300”) in the transient voltage protection element using the resin composition according to the present embodiment. explain.

  When the resin composition according to the present embodiment is used, a member (structure 300) exhibiting varistor characteristics can be manufactured with a high yield by any one of the resin molding methods of compression molding and transfer molding. Here, in the case of adopting a method of compressing and molding the resin composition in order to produce the structure 300, the resin composition may be processed into granules, powders, or sheets. preferable. On the other hand, in the case of adopting a transfer molding method of the resin composition for producing the structure 300, the resin composition is preferably processed into a tablet shape.

  Hereinafter, an example of a method for producing the structure 300 according to the present embodiment will be described with reference to an example in which the structure 300 is manufactured by compression molding using a granular resin composition. However, the method for producing the structure 300 according to this embodiment is not limited to the following example.

  First, a resin material supply container containing a granular resin composition is installed between an upper mold and a lower mold of a compression mold.

  Next, under reduced pressure, while the interval between the upper and lower molds of the mold is reduced, the weighed granular resin composition is removed from the lower mold by a resin material supply mechanism such as a shutter that constitutes the bottom surface of the resin material supply container. Into the lower mold cavity. As a result, the granular resin composition is heated to a predetermined temperature in the lower mold cavity to be in a molten state. Next, the molten resin composition is pressed against the upper mold by bonding the upper mold and the lower mold of the mold. Thereafter, the resin composition is cured over a predetermined time while maintaining the state in which the upper mold and the lower mold are bonded. Thereby, a resin composition can express a varistor characteristic reliably. Here, when performing compression molding, it is preferable to perform resin sealing while reducing the pressure inside the mold, and it is more preferable to perform the sealing under vacuum conditions. Thereby, it can be satisfactorily filled without leaving an unfilled portion of the resin composition.

In addition, the molding temperature in the case of compression molding using a granular resin composition is not particularly limited, but is preferably 50 to 250 ° C, more preferably 50 to 200 ° C, and particularly preferably 80 to 180 ° C. preferable. The molding pressure is not particularly limited, but is preferably 0.5 to 12 MPa, and particularly preferably 1 to 10 MPa. By setting the molding temperature and pressure within the above ranges, it is possible to prevent the occurrence of a portion that is not filled with the molten resin composition.

  Next, an example of a method for producing the structure 300 according to the present embodiment will be described by taking as an example a case where the structure 300 is manufactured by compression molding using a sheet-shaped resin composition.

  First, a sheet-like resin composition is placed in a lower mold cavity of a mold. Next, by reducing the distance between the upper mold and the lower mold of the mold under reduced pressure, the sheet-shaped resin composition is heated to a predetermined temperature in the lower mold cavity to be in a molten state. Then, the molten resin composition is pressed against the upper mold by bonding the upper mold and the lower mold of the mold. Thereafter, the resin composition is cured over a predetermined time while maintaining the state in which the upper mold and the lower mold are bonded. Thereby, a resin composition can express a varistor characteristic reliably. Here, when performing compression molding, it is preferable to perform resin sealing while reducing the pressure inside the mold, and it is more preferable to perform the sealing under vacuum conditions. Thereby, it can be satisfactorily filled without leaving an unfilled portion of the resin composition.

  The molding temperature in the case of compression molding using a sheet-shaped resin composition is not particularly limited, but is preferably 50 to 250 ° C, more preferably 50 to 200 ° C, and particularly preferably 80 to 180 ° C. preferable. The molding pressure is not particularly limited, but is preferably 0.5 to 12 MPa, and particularly preferably 1 to 10 MPa. By setting the molding temperature and pressure within the above ranges, it is possible to prevent the occurrence of a portion that is not filled with the molten resin composition.

  Next, an example of a method for producing the structure 300 according to this embodiment will be described by taking as an example the case where the structure 300 is manufactured by transfer molding using a tablet-like resin composition.

  First, a molding die is prepared. The molding die prepared here was melted with a pot charged with a tablet-shaped resin composition, and then a plunger with an auxiliary ram inserted into the pot to melt the resin composition by applying pressure. A sprue for feeding the resin composition into the molding space is provided.

  Next, the tablet-shaped resin composition is charged into the pot with the molding die closed. Here, the form of the resin composition charged in the pot may be in a semi-molten state by preheating with a preheater or the like in advance. Next, in order to melt the resin composition charged in the pot, a plunger having an auxiliary ram is inserted into the pot to apply pressure to the resin composition. Thereafter, the molten resin composition is introduced into the molding space through a sprue. Next, the resin composition filled in the molding space is cured by being heated and pressurized. After the resin composition is cured, the structure 300 in which the resin composition surely exhibits the varistor characteristics can be obtained by opening the molding die.

  The molding temperature in transfer molding is not particularly limited, but is preferably 50 to 250 ° C, more preferably 50 to 200 ° C, and particularly preferably 80 to 180 ° C. By making molding temperature into the said range, it can prevent that the part which is not filled with the resin composition of a molten state generate | occur | produces.

The protective member according to the present invention is molded from a thermosetting resin and a resin composition containing semiconductor ceramic particles having a grain boundary part and a plurality of crystal parts separated by the grain boundary part, and a voltage-current A protection member that exhibits non-linearity that does not follow Ohm's law and protects a transient voltage with respect to the circuit to be protected, and is disposed between a terminal of the circuit to be protected and ground, and the ground has one end The other end of the capacitor connected to the ground of the circuit to be protected is also connected. As the resin composition, the resin composition according to the present invention can be used.

  The protective member according to the present invention can be manufactured using the resin composition according to the present embodiment in the same manner as the above-described method for manufacturing the protective part in the transient voltage protective element.

1 ... IC
DESCRIPTION OF SYMBOLS 2 ... Output object 3 ... Conventional transient voltage protection element 10 ... Transient voltage protection element to which this invention is applied 21 ... Protection part 22 ... Capacitor part 31 ... Ceramic dielectric 32 ... Internal electrode 33 ... External electrode 51 ... Substrate 61 ... Electrode 62 ... Dielectric 63 ... Electrode 100 ... Semiconductor ceramic particles 110 ... Crystal part 120 ... Grain Field part 130 ... Electrode terminal 150 ... Conductive particle 200 ... Resin material 300 ... Member (structure) showing varistor characteristics

Claims (4)

A protective part which is arranged between the terminal of the circuit to be protected and the ground, and exhibits non-linearity in which the voltage-current characteristic does not follow Ohm's law;
A capacitor unit disposed between the ground of the protection unit and the ground of the protection target circuit;
A transient voltage protection device comprising: The protection part is a member connected to one of the two electrodes of the capacitor part.
The transient voltage protection element according to claim 1. A resin composition comprising:
Including a thermosetting resin and semiconductor ceramic particles;
The semiconductor ceramic particles have a grain boundary part and a plurality of crystal parts separated by the grain boundary part,
The cured product of the resin composition exhibits non-linearity in which voltage-current characteristics do not follow Ohm's law,
Among the transient voltage protection elements comprising a protection unit disposed between the terminal of the protection target circuit and the ground, and a capacitor unit disposed between the ground of the protection unit and the ground of the protection target circuit, A resin composition used for molding into a protective part. A protective member that is molded from a resin composition and protects a transient voltage for a circuit to be protected,
The resin composition is
Including a thermosetting resin and semiconductor ceramic particles;
The semiconductor ceramic particles have a grain boundary part and a plurality of crystal parts separated by the grain boundary part,
The protective member exhibits non-linearity in which the voltage-current characteristic does not follow Ohm's law,
Arranged between the terminal of the circuit to be protected and ground,
The ground is also connected to the other end of the capacitor, one end of which is connected to the ground of the circuit to be protected.
Protective member.

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