JP2016219715A - Insulation gate bipolar transistor element, resin composition, and surge countermeasure member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a size of a device including an IGBT.SOLUTION: An insulation gate bipolar transistor element including a gate, an emitter, and a collector, comprises a surge countermeasure part which is a high voltage protection member connected to at least two of the gate, emitter, and collector, and has a voltage-current characteristic indicating nonlinearity which dose not conform to ohm's law. An IGBT element 1 including a gate G, an emitter E, a collector C comprises the surge countermeasure part 3 which is connected to a gate C and the emitter E, and is formed by an insulation material with a varistor function. Thus, it is not required to separately provide the surge countermeasure element.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an insulated gate bipolar transistor element, a resin composition, and a surge countermeasure member.

  Conventionally, an insulated gate bipolar transistor (hereinafter referred to as IGBT) has been used as a switching element of a power converter such as a variable speed driving device of a motor or an uninterruptible power supply (refer to Patent Document 1). ).

In recent years, downsizing of such a power converter is required.
For example, a variable speed drive device for a motor is not particularly required to be downsized when applied to a large facility such as a train or a rolling facility. However, when applied to an electric vehicle that has recently appeared, downsizing is not possible. is necessary.

JP 2013-041782 A

However, when a high surge voltage is applied to the gate drive voltage of the IGBT, an oxide film (SIO ₂ or the like) between the gate and the emitter may cause a dielectric breakdown, thereby destroying the IGBT and causing a failure of the device. As a conventional countermeasure for this, a countermeasure is taken in which a surge countermeasure element such as a varistor is separately prepared between the gate and the emitter of the IGBT. Such conventional countermeasures require a separate space for providing a surge countermeasure element, which is a factor that hinders downsizing of devices including IGBTs such as power converters.

  This invention is made | formed in view of such a condition, and aims at size reduction of the apparatus containing IGBT.

In order to achieve the above object, an IGBT element (insulated gate bipolar transistor element) according to an aspect of the present invention includes:
An insulated gate bipolar transistor device having a gate, an emitter and a collector,
A surge countermeasure unit that is connected to at least two of the gate, the emitter, and the collector, and is a high-voltage protection member that exhibits non-linearity in which voltage-current characteristics do not follow Ohm's law;
It is characterized by that.

  The surge countermeasure unit may be connected to the gate and the emitter, respectively.

  The surge countermeasure portion may be a member connected to the terminal of the gate electrode and the terminal of the emitter electrode.

One embodiment of the present invention provides:
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,
It is a resin composition used for molding into a surge countermeasure part connected to at least two of the gate, emitter and collector of an insulated gate bipolar transistor element.

One embodiment of the present invention provides:
A surge countermeasure member molded from a resin composition,
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 surge countermeasure member exhibits non-linearity in which the voltage-current characteristic does not follow Ohm's law,
It is a surge countermeasure member connected to at least two of the gate, emitter and collector of the insulated gate bipolar transistor element.

  According to the present invention, it is possible to reduce the size of a device including an IGBT.

It is a figure which shows the outline | summary of a structure of the IGBT element which concerns on one Embodiment of this invention. It is a circuit diagram of the arc-extinguishing apparatus to which the IGBT element of FIG. 1 is applied. The structural example of the external appearance of the IGBT element which concerns on one Embodiment of this invention is shown. 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. 1 is a diagram showing an outline of the configuration of an IGBT element 1 according to an embodiment of the present invention.
Specifically, FIG. 1A is an equivalent circuit diagram of the IGBT element 1 in the present embodiment. FIG. 1B is a schematic diagram showing a cross-sectional structure of the IGBT element 1 of the present embodiment.
In the IGBT element 1 in this embodiment, a transistor called IGBT is formed. Specifically, as shown in FIG. 1, the IGBT element 1 according to the present embodiment includes a transistor section 2 that functions as a transistor and a surge countermeasure section 3 that has the same function as the surge countermeasure element.
For example, the IGBT element 1 can have a size of 10 mm × 10 mm. In addition, the said size is an illustration and the IGBT element 1 of various various sizes can be provided according to a specification etc.

  The transistor unit 2 has a structure basically similar to that of a conventional IGBT. That is, the transistor portion 2 is not particularly limited to the planar structure shown in FIG. 1B of the present embodiment, and may have a structure capable of exhibiting a function required for the IGBT.

  In FIG. 1B, the collector C side is called the lower side, and the gate G and emitter E side is called the upper side. The left emitter E side in the figure is called the left side, and the right emitter E side is called the right side.

In the transistor portion 2, the collector electrode 10, the P layer 11, and the N layer 12 are stacked in that order from the bottom to the top. A P layer 13-1 is laminated on the left side of the N layer 12, and an N layer 14-1 is laminated on the central portion of the P layer 13-1. Similarly, a P layer 13-2 is laminated on the right side of the N layer 12, and an N layer 14-2 is laminated on the central portion of the P layer 13-2.
An emitter electrode 15-1 is laminated on the P layer 13-1 and the N layer 14-1. Similarly, an emitter electrode 15-2 is stacked on the P layer 13-2 and the N layer 14-2.
On the N layer 14-1, the P layer 13-1, the N layer 12, the P layer 13-2, and the N layer 14-2, the gates are separated from the emitter electrodes 15-1 and 15-2, respectively. An oxide film 16 is laminated.
A gate electrode 18 is stacked on the gate oxide film 16 with a polysilicon film 17 interposed therebetween.

The surge countermeasure unit 3 is formed from an insulating material with a varistor function, which is connected to the gate G and the emitter E, respectively.
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. In other words, the varistor function-equipped insulating material is a high-voltage protection member that exhibits nonlinearity in which the voltage-current characteristics do not follow Ohm's law. Details of the insulating material with varistor function will be described later with reference to FIGS.
Here, “connected” means electrically connected when a voltage exceeding the predetermined voltage is applied.

That is, when a surge voltage exceeding the predetermined voltage is generated in the gate G, a current flows between the gate G and the emitter E in the surge countermeasure unit 3. Thereby, damage to IGBT element 1 in this embodiment can be prevented.
As described above, in the IGBT element 1 of the present embodiment, the surge countermeasure unit 3 is provided as one element of the IGBT element 1, so that it is possible to take a surge countermeasure with a small parasitic capacitance and a high operating speed.
Furthermore, since a conventional surge countermeasure element is not required, that is, a space for providing a conventional surge countermeasure element is not required, it is possible to reduce the size of a device including an IGBT such as a power converter. .
Furthermore, since it is not necessary to make various components (including the surge countermeasure part 3) constituting the IGBT element 1 into a special shape, the manufacturing itself is facilitated, and the work of incorporating and connecting them is also easy. become. As a result, the entire IGBT element 1 can be easily manufactured, and the manufacturing cost can be reduced.
On the other hand, even if it is necessary to make the components other than the surge countermeasure part 3 into a special shape according to various specifications and demands, the work of incorporating and connecting them by using an insulating material with a varistor function that excels in formability And the like are easier than in the prior art of Patent Document 1 and the like. 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 freedom of the IGBT element 1 is increased.

(Manufacturing method of IGBT element)
Since the manufacturing method of the transistor part 2 itself is basically the same as the manufacturing method of the conventional IGBT, the description thereof is omitted here.
For example, after the transistor portion 2 is manufactured, the surge countermeasure portion 3 having a shape such that the gate G and the emitter E are connected is manufactured using an insulating material with a varistor function.
A method of manufacturing the insulating material with varistor function itself will be described later with reference to FIGS.
Here, in the example of FIG. 1B, the space is drawn between the transistor portion 2 and the surge countermeasure portion 3. Therefore, for example, by interposing an insulating layer (intermediate layer) between the transistor part 2 and the surge countermeasure part 3, the transistor part 2 and the surge countermeasure part 3 can be easily formed in a laminated structure.

(Application example of IGBT element)
FIG. 2 is a circuit diagram of an arc extinguishing apparatus to which the IGBT element of this embodiment of FIG. 1 is applied.
The arc extinguishing device is a device that erases an arc generated in a mechanical switch, and is provided in a switch such as a circuit breaker for wiring, an earth leakage breaker, or an electromagnetic contactor, for example.
In the example of FIG. 2, an arc extinguishing device 104 is provided for the circuit breaker 101 for wiring.

The circuit breaker 101 for wiring is provided with terminals 111 to 114 for external connection (not shown) and two electrical contacts 121 and 122 constituting a mechanical (contact type) switch. Although not shown, the electrical contacts 121 and 122 can be simultaneously closed (ON) and opened (OFF) by operating a manual lever.
Both ends of the electrical contact 121 are connected to the terminal 111 and the terminal 112. Further, both ends of the electrical contact 122 are connected to the terminal 113 and the terminal 114. Although not shown, the terminal 112 and the terminal 113 are electrically connected externally.
That is, one end of each of the electrical contact 121 and the electrical contact 122 is connected in series via the terminals 112 and 113. Thereby, the electrical contact 121 and the electrical contact 122 constitute a mechanical switch.
One end of the electrical contact 121 is connected to the terminal 111, and one end of the electrical contact 122 is connected to the terminal 114.

The arc extinguishing device 104 erases the arc generated during the opening operation of the electrical contact 121 and the electrical contact 122 in synchronization (interlocking) with the opening operation.
For this purpose, the arc extinguishing device 104 includes the IGBT element 1 of this embodiment shown in FIG. 1, resistors 141 and 142, and a capacitor 144.

The IGBT element 1 is connected in parallel to a series circuit of the circuit breaker 101 for wiring (a series circuit in which the electrical contacts 121 and 122 are connected in series). That is, in the transistor part 2 of the IGBT element 1, the collector C is connected to the terminal 111 and the emitter E is connected to the terminal 114.
The resistors 141 and 142 are connected in series to the electric contact 122 of the circuit breaker 101 for wiring, thereby forming a voltage dividing circuit 145 that divides the arc voltage generated at the electric contact 122. A voltage dividing terminal of the voltage dividing circuit 145 is connected to the gate G of the transistor portion 2 of the IGBT element 1.
A capacitor 144 that holds the voltage of the gate G is connected between the gate G and the emitter E of the transistor portion 2 of the IGBT element 1.

Here, conventionally, a conventional IGBT corresponding to the transistor section 2 and a surge countermeasure element such as a varistor corresponding to the surge countermeasure section 3 are separately required.
On the other hand, by adopting the IGBT element 1 of this embodiment, a surge countermeasure element becomes unnecessary. As a result, it is possible to easily manufacture the arc extinguishing device 104 in a simple and small size as compared with the case where the conventional IGBT is adopted (when a surge countermeasure element is separately required).

Here, the IGBT element to which the present invention is applied is not limited to the above-described embodiment, and modifications, improvements, and the like within a range in which the object of the present invention can be achieved are included in the present invention.

For example, the surge countermeasure part 3 can take the form of a laminated structure together with the transistor part 2 as described above, but can take the form shown in FIG.
FIG. 3 shows an external configuration example of an IGBT element 1 according to another embodiment of the present invention.
In the IGBT element 1 having the external configuration shown in FIG. 3, the transistor unit 2 is housed in a casing (the structure is not shown but is the same as that in FIG. 1B), the terminal of the gate G, the terminal of the emitter E, and The terminal of the collector C and the surge countermeasure part 3 are provided.
The surge countermeasure unit 3 is formed as a member formed from an insulating material with a varistor function, which is connected to each terminal of the gate G and the emitter E.
In this case, the IGBT element 1 can have a size of, for example, 10 mm × 10 mm. In addition, the said size is an illustration and the IGBT element 1 of various various sizes can be provided according to a specification etc.
Here, since the surge countermeasure part 3 consists of an insulating material with a varistor function which is excellent in a moldability, it can be manufactured with a simple configuration as shown in FIG.
Furthermore, since the surge countermeasure unit 3 shown in FIG. 3 has a structure that can be freely attached to and detached from the terminals of the gate G and the emitter E, it is manufactured together with the IGBT element 1 as one component of the IGBT element 1. It can also be manufactured independently of the IGBT element 1 as a part of the IGBT element 1.
That is, since the IGBT element 1 is completed simply by fitting the surge countermeasure part 3 to a part other than the surge countermeasure part 3, the entire IGBT element 1 can be easily manufactured, and the manufacturing cost can be reduced. Is also possible.
Here, the portions other than the surge countermeasure portion 3 can have various shapes according to various specifications and requests, but since any insulating material with a varistor function having excellent formability can be used, for any shape However, the suitable surge countermeasure part 3 can be manufactured easily. As a result, the degree of freedom in designing the IGBT element 1 is increased.

Moreover, the following resin composition may be sufficient as the surge countermeasure part shape | molded from the insulating material with a 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, and is connected to at least two of the gate, emitter, and collector of the insulated gate bipolar transistor device (in the above embodiment, the gate and the emitter). Used to be molded into the surge countermeasure section. 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 surge countermeasure part as a component of the IGBT element with a high yield. Therefore, as in the conventional case, the IGBT element and the surge countermeasure element are arranged in the circuit. As a result, it is possible to realize a countermeasure with a simple structure, a small parasitic capacitance, and a high operating speed as a countermeasure against a surge on the IGBT element, and further, a device including an IGBT such as a power converter. Can be reduced in size.

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 an IGBT element, and the first terminal and the second terminal correspond to two arbitrarily selected from a gate, an emitter, and a collector. 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 surge, it has been usual to employ a configuration in which an IGBT element and a surge countermeasure element are arranged in a circuit. Therefore, conventionally, it has been necessary to secure a space for arranging the surge countermeasure element. Therefore, in recent years, there has been a limit for the simple configuration, small parasitic capacitance, and high operating speed required for surge countermeasures, and downsizing of devices including IGBTs such as power converters. . In view of such circumstances, the present inventor can realize a simple configuration, a small parasitic capacitance, and a high operating speed if a surge countermeasure unit can be provided as an element of an IGBT element, and further, an IGBT such as a power converter. I thought that it was possible to reduce the size of equipment including Specifically, the present inventor, in an IGBT element having a gate, an emitter, and a collector, can be disposed so as to be in contact with at least two of the gate, the emitter, and the collector, for example, is in the form of a film, and It has been found that realizing a member exhibiting varistor characteristics 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 1st characteristic requested | required of the said resin composition is the grade which can control the shape of the said member so that it can respond to the shape of the electrode terminal mounted in the IGBT element which is a use object of the member which shows a varistor characteristic. 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, as a result of earnestly examining the design guideline for producing the resin material that satisfies the above three required characteristics, the present inventor has obtained semiconductor ceramic particles 100 having varistor characteristics (see FIG. 4), When blended in the resin composition, a member capable of having a structure having a function of protecting the IGBT element from an external load of a stress applied from a surge voltage or an external environment is produced in the IGBT element with a high yield. The knowledge that it was possible 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. 5 and 6) 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 Phenyl borate, tetraphenylphosphonium ・ tetrabenzoic acid borate, tetraphenylphosphonium ・ tetranaphthoic acid borate, tetraphenylphosphonium ・ tetranaphthoyloxyborate, tetraphenylphosphonium ・
And tetrasubstituted phosphonium / tetrasubstituted borates such as tetranaphthyloxyborate; triphenylphosphine adducted with benzoquinone, and the 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. 4 is an enlarged cross-sectional view of the semiconductor ceramic particle according to the present embodiment.
As shown in FIG. 4, 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 an arrow 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. In this way, when a high voltage exceeding the varistor voltage is applied to the IGBT element including the structure 300 formed of the present resin composition, the electrical conductivity of the structure 300 is further improved. Can be. Specifically, as shown in FIG. 6, 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. 6, the conductive particles 150 can easily enter the gap regions of 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 employing such a configuration, it is possible to provide a configuration having a function of protecting the IGBT device from an external load of a stress applied from a surge voltage or an external environment in the IGBT device. Therefore, unlike the conventional electronic parts, it is not necessary to arrange the IGBT element and the surge countermeasure element in the circuit. As a result, as a surge countermeasure for the IGBT element, the parasitic capacitance is small and the operation is simple. A fast measure can be realized, and further, downsizing of devices including IGBTs such as power converters can be achieved.

  Hereinafter, a method for producing a surge countermeasure part (hereinafter, also referred to as “member showing varistor characteristics” and / or “structure 300”) as an element of an IGBT 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 is produced as a component of the IGBT element with a high yield by any one of the compression molding method and the transfer molding method. be able to. Therefore, the structure 300 corresponding to the shape of the electrode terminal can be manufactured. 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.

  As an example of a method for manufacturing a member (structure 300) exhibiting varistor characteristics as one element of an IGBT element, for example, the IGBT element is in contact with at least two of the gate, emitter, and collector of the IGBT element. Thus, the method including the process of forming the structure 300 (high voltage protection member) by compression-molding or transfer-molding this resin composition is mentioned.

  Hereinafter, with respect to an example of a method for mounting the structure 300 according to the present embodiment as an element of an IGBT element, first, as an example, the structure 300 is manufactured by compression molding using a granular resin composition. I will give you a description. However, the method of mounting the structure 300 according to this embodiment as one element of the IGBT element 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, the IGBT element is fixed to one of the upper mold and the lower mold of the compression mold by a fixing means such as clamp or suction. In the following description, the IGBT element is fixed to the upper mold of the compression mold so that the surface having at least two of the gate, emitter and collector of the IGBT element faces the resin material supply container. To do.

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, by bonding the upper mold and the lower mold of the mold, the molten resin composition is pressed against at least two of the gate, emitter, and collector included in the IGBT element fixed to the upper mold. By doing so, the gap formed between at least two of the gate, emitter and collector can be filled with the molten resin composition. 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, at least the region surrounding at least two of the gate, the emitter and the collector 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 the pressure within the above ranges, it is possible to prevent both occurrence of a portion not filled with the molten resin composition and displacement of the IGBT element.

  Next, as an example of a method for mounting the structure 300 according to the present embodiment as an element of an IGBT element, a case where the structure 300 is manufactured by compression molding using a sheet-like resin composition is taken as an example. I will explain.

  First, the IGBT element is fixed to one of the upper mold and the lower mold of the compression molding mold by a fixing means such as clamp or suction. In the following description, the IGBT element is fixed to the upper mold of the compression mold so that the surface having at least two of the gate, emitter and collector of the IGBT element faces the resin material supply container. To do.

  Next, a sheet-like resin composition is disposed in the lower mold cavity of the mold so that the position corresponds to at least two of the gate, emitter, and collector of the IGBT element fixed to the upper mold of the 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. Thereafter, the upper mold and the lower mold of the mold are combined to press the molten resin composition against at least two of the gate, emitter, and collector provided in the IGBT element fixed to the upper mold. By doing so, the gap formed between at least two of the gate, emitter and collector can be filled with the molten resin composition. 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, at least the region surrounding at least two of the gate, the emitter and the collector 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 the pressure within the above ranges, it is possible to prevent both occurrence of a portion not filled with the molten resin composition and displacement of the IGBT element.

  Next, as an example of a method for mounting the structure 300 according to this embodiment as an element of an IGBT element, a case where the structure 300 is manufactured by transfer molding using a tablet-like resin composition is taken as an example. I will explain.

First, a molding die provided with an IGBT element 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, an IGBT element including the structure 300 in which the resin composition surely exhibits 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 setting the molding temperature in the above range, it is possible to prevent both occurrence of a portion not filled with the molten resin composition and displacement of the IGBT element.

  The surge countermeasure 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 − The current characteristic exhibits nonlinearity that does not follow Ohm's law, and is connected to at least two of the gate, emitter, and collector of the insulated gate bipolar transistor device (in the above-described embodiment, the gate and the emitter). As the resin composition, the resin composition according to the present invention can be used.

  The surge countermeasure 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 producing a surge countermeasure portion as an element of an IGBT element.

DESCRIPTION OF SYMBOLS 1 ... IGBT element 2 ... Transistor part 3 ... Surge countermeasure part 10 ... Collector electrode 11 ... P layer 12 ... N layer 13-1, 13-2 ... P layer 14 -1,14-2 ... N layer 15-1,15-2 ... emitter layer 17 ... polysilicon film 18 ... gate electrode 100 ... semiconductor ceramic particles 101 ... interconnection for wiring 104 ... Arc extinguishing device 110 ... Crystal part 111 ... Terminal 112 ... Terminal 113 ... Terminal 114 ... Terminal 120 ... Grain boundary part 121 ... Electrical contact 122 ... Electrical contact 130: Electrode terminal 141: Resistance 142 ... Resistance 144 ... Capacitor 150 ... Conductive particles 200 ... Resin material 300 ... Member showing varistor characteristics (structure)

Claims (5)

An insulated gate bipolar transistor device having a gate, an emitter and a collector,
A surge countermeasure unit that is connected to at least two of the gate, the emitter, and the collector, and is a high-voltage protection member that exhibits non-linearity in which voltage-current characteristics do not follow Ohm's law;
Insulated gate bipolar transistor element. The surge countermeasure part is a member connected to the gate and the emitter, respectively.
The insulated gate bipolar transistor device according to claim 1. The surge countermeasure part is a member connected to the terminal of the gate electrode and the terminal of the emitter electrode, respectively.
The insulated gate bipolar transistor device according to claim 2. 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,
A resin composition used for forming a surge countermeasure portion connected to at least two of a gate, an emitter and a collector of an insulated gate bipolar transistor element. A surge countermeasure member molded from a resin composition,
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 surge countermeasure member exhibits non-linearity in which the voltage-current characteristic does not follow Ohm's law,
A surge countermeasure member connected to at least two of the gate, emitter and collector of the insulated gate bipolar transistor element.

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