Sealing material for power semiconductor device, sealing material, and power semiconductor device

Abstract

The present disclosure relates to an encapsulation material for a power semiconductor device, which contains a compound having a vinyl phenyl group.

Description

Technical Field

[0001] This disclosure relates to materials for packaging power semiconductor devices, sealing agents, power semiconductor devices, and power semiconductor modules. Background Technology

[0002] In recent years, semiconductor devices have been used more frequently in high-current or high-voltage environments such as automobiles, electric vehicles, wind power generation, and solar power generation. Along with this trend, resistance to tracking current (high CTI (Comparative Tracking Index)) has become increasingly important. In particular, high resistance to tracking current is required for semiconductor devices known as power semiconductors.

[0003] Semiconductor devices typically use cured epoxy resin compositions as encapsulation materials for semiconductor elements (e.g., Patent Document 1 and Patent Document 2). To improve the tracking resistance of the epoxy resin itself, Patent Document 1 discloses a composition with dicyclopentadiene-type epoxy resin as a necessary component. Patent Document 2 discloses a composition in which spherical cristobalite is added to the epoxy resin composition.

[0004] [Existing technical documents]

[0005] [Patent Literature]

[0006] Patent Document 1: Japanese Patent Application Publication No. 2005-213299

[0007] Patent Document 2: Japanese Patent Application Publication No. 2013-112710 Summary of the Invention

[0008] [The problem the invention aims to solve]

[0009] This disclosure provides a packaging material for power semiconductor devices that exhibits excellent resistance to tracking. Furthermore, this disclosure provides a packaging material with excellent resistance to tracking. Additionally, this disclosure provides a power semiconductor device and a power semiconductor module with excellent resistance to tracking.

[0010] [Technical means to solve the problem]

[0011] This invention includes the following embodiments. However, this invention is not limited to these embodiments. One embodiment relates to a packaging material for a power semiconductor device containing a compound having a vinylphenyl group. Another embodiment relates to a packaging material containing a cured product obtained using said packaging material. Another embodiment relates to a power semiconductor device having a semiconductor element and said packaging material encapsulating at least a portion of said semiconductor element. Another embodiment relates to a power semiconductor module having a plurality of semiconductor elements selected from the group consisting of semiconductor elements and semiconductor devices, and said packaging material encapsulating at least a portion of said plurality of semiconductor elements.

[0012] [The effects of the invention]

[0013] According to this disclosure, a packaging material for a power semiconductor device is provided, which provides a packaging material with excellent resistance to tracking. Furthermore, this disclosure provides a packaging material with excellent resistance to tracking. Additionally, this disclosure provides a power semiconductor device and a power semiconductor module with excellent resistance to tracking. Attached Figure Description

[0014] none Detailed Implementation

[0015] The present invention is described in the following embodiments. The present invention is not limited to the following embodiments. The following embodiments can be implemented individually or in combination. Combinations of multiple embodiments are also included in the present invention.

[0016] In this disclosure, the numerical range represented by “~” means the range containing the values ​​before and after “~” as the minimum and maximum values, respectively.

[0017] In the numerical ranges described progressively in this disclosure, the upper or lower limit of a certain numerical range can be replaced with the upper or lower limit of another numerical range. The upper or lower limit of the numerical ranges described in this disclosure can be replaced with the values ​​shown in the embodiments.

[0018] In this disclosure, a value can be selected from the upper and lower limits of the segmented values ​​to represent the segmented numerical range. The upper and lower limits of the values ​​recorded in this disclosure can be replaced with the values ​​shown in the embodiments.

[0019] In this disclosure, each component may comprise multiple corresponding substances. When multiple substances corresponding to each component are present in the composition, the content or percentage of each component, unless otherwise specified, refers to the total content or percentage of the multiple substances present in the composition.

[0020] In this disclosure, each structure in the polymer may include multiple corresponding structures. When multiple structures corresponding to each structure are present in the polymer, the content or percentage of each structure, unless otherwise specified, refers to the total content or percentage of the multiple structures present in the polymer.

[0021] In this disclosure, the particles corresponding to each component may comprise a variety of particles. When a variety of particles corresponding to each component are present in the composition, the particle size of each component, unless otherwise specified, refers to the value of the mixture of the various particles present in the composition.

[0022] <Materials for Packaging>

[0023] The packaging material is used in power semiconductor devices. The packaging material contains at least a compound having a vinylphenyl group. The packaging material may also contain a compound having a vinyl bond. In this disclosure, a vinyl compound is a compound different from a compound having a vinylphenyl group; it is a compound that does not belong to the category of compounds having a vinylphenyl group. Compounds having a vinyl bond do not have a vinylphenyl group. In this disclosure, compounds having a vinylphenyl bond are sometimes referred to as "vinylphenyl compounds." In this disclosure, compounds having a vinyl group are sometimes referred to as "vinyl compounds."

[0024] The cured product obtained using the encapsulation material can be used as an encapsulation material for encapsulating one or both of power semiconductor elements and power semiconductor devices. The encapsulation material can be an encapsulation material composition containing various compounds. In some embodiments, the encapsulation material is a free-radical polymerizable encapsulation material that can be polymerized to form a cured product through free-radical polymerization. The encapsulation material can be a free-radical polymerizable composition containing various compounds.

[0025] [Compounds containing vinylphenyl groups]

[0026] A vinylphenyl compound is a compound having at least one vinylphenyl group. A vinylphenyl compound may have, for example, 1 to 20, 1 to 15, or 1 to 10 vinylphenyl groups. A vinylphenyl compound may consist of one vinylphenyl compound or may contain two or more vinylphenyl compounds. When the encapsulation material contains a vinylphenyl compound, the tracking properties of the cured product are increased. One reason for this is the high reactivity of the vinylphenyl compound. When the vinylphenyl compound is highly reactive, the curing reaction of the encapsulation material is more readily and fully carried out. As a result, the crosslinking density of the obtained cured product is higher, thereby increasing the thermal decomposition temperature and improving tracking properties. Furthermore, when the crosslinking density is higher, the molding shrinkage rate of the cured product is also reduced. However, these are merely speculations, and the present invention is not limited to these speculations.

[0027] Vinylphenyl can be represented by any of the following formulas. From the viewpoint of obtaining cured products with low dielectric constants and low dielectric tangents, vinylphenyl compounds may contain compounds having a group represented by formula (p). * indicates the bonding position with other atoms.

[0028] [Chemistry 1]

[0029]

[0030] The ratio of groups represented by formula (p), groups represented by formula (m), and groups represented by formula (o) in the total amount of vinylphenyl compounds contained in the encapsulation material (molar ratio of groups represented by formula (p): groups represented by formula (m): groups represented by formula (o)) is, for example, 40–100:0–60:0–60, 70–90:0:10–30, or 40–60:40–60:0. The higher the ratio of groups represented by formula (p), the lower the dielectric constant and dielectric tangent tendency of the cured product.

[0031] Vinylphenyl compounds can be compounds having a vinylphenyl methyl group (also called "vinylbenzyl"). In this disclosure, compounds having a vinylbenzyl group are sometimes referred to as "vinylbenzyl compounds." Examples of vinylbenzyl compounds correspond to vinylphenyl compounds. Vinylphenyl compounds can also be compounds having a vinylphenyl methyloxy group (also called "vinylbenzyl ether group"). In this disclosure, compounds having a vinylbenzyl ether group are sometimes referred to as "vinyl benzyl ether compounds." Examples of vinylbenzyl ether compounds correspond to both vinylbenzyl compounds and vinylphenyl compounds.

[0032] Vinylphenyl compounds can be monomers or polymers capable of free radical polymerization. Vinylphenyl compounds, for example, comprise monomers having a vinylphenyl group. In this disclosure, monomers having a vinylphenyl group are sometimes referred to as "vinylphenyl-containing monomers." Vinylphenyl compounds, for example, comprise polymers having a vinylphenyl group. In this disclosure, polymers having a vinylphenyl group are sometimes referred to as "vinylphenyl-containing polymers." In this disclosure, monomers can be compounds that do not contain repeating structural units. Polymers can be compounds that contain repeating structural units. Polymers can be low-degree polymers (i.e., oligomers) or high-degree polymers.

[0033] In some embodiments, the vinylphenyl compound comprises a compound having two vinylphenyl groups. The compound having two vinylphenyl groups can be a monomer or a polymer. In some embodiments, the vinylphenyl compound comprises a compound having three or more vinylphenyl groups. The compound having three or more vinylphenyl groups can be a monomer or a polymer.

[0034] Vinylphenyl compounds include, for example, compounds containing structural units represented by the following formula (Bb).

[0035] [Chemistry 2]

[0036]

[0037] (In the formula, X represents an organic group, B represents an individual group containing vinylphenyl, R represents an individual substituent, l represents an integer from 1 to 5, and m represents an integer from 0 to 10. * indicates the bond position with other atoms.)

[0038] The term "independent" regarding B means, for example, that when l is 2 or more and the structural unit represented by formula (Bb) has multiple Bs, the multiple Bs can be the same "containing vinylphenyl group," or, partially or entirely, can be different "containing vinylphenyl groups." In this case, "independent" does not preclude l from being 1, and the structural unit represented by formula (Bb) can also be a structural unit having one "containing vinylphenyl group." Similar to "(B)" in this disclosure... l The way “” is expressed is also the same.

[0039] As an example of X, the following X can be listed. b1 and X B1 Examples of compounds having the structural unit represented by formula (Bb) include compounds represented by formula (b1) and polymers represented by formula (B1) described later.

[0040] (Contains vinylphenyl monomer)

[0041] In some embodiments, the vinylphenyl compound comprises a vinylphenyl-containing monomer. The vinylphenyl-containing monomer comprises a monomer having two vinylphenyl groups, and may further comprise at least one selected from the group consisting of monomers having one vinylphenyl group and monomers having three vinylphenyl groups; alternatively, it may comprise a monomer having two vinylphenyl groups, a monomer having one vinylphenyl group, and a monomer having three vinylphenyl groups. When the vinylphenyl-containing monomer comprises two or more vinylphenyl-containing monomers, the average number of vinylphenyl groups in the vinylphenyl-containing monomer is, for example, 1.2 to 2.8, 1.4 to 2.7, or 1.6 to 2.6.

[0042] The vinylphenyl monomer may further have an aromatic ring. The vinylphenyl monomer may have only one aromatic ring, or it may have two or more aromatic rings. The number of carbon atoms in the aromatic ring may be, for example, 2–30, 6–20, or 9–15. The aromatic ring may be an aromatic hydrocarbon ring or an aromatic heterocycle. The aromatic ring may be a monocyclic or fused polycyclic ring. Examples of aromatic hydrocarbon rings include benzene, naphthalene, anthracene, tetraphenylene, fluorene, phenanthrene, indene, indane, and biphenylene. Examples of aromatic heterocyclic compounds include pyridine, pyrazine, quinoline, isoquinoline, acridine, phenanthroline, furan, pyrrole, thiophene, carbazole, oxazole, oxadiazole, thiadiazole, triazole, benzoxazole, benzoxadiazole, benzothiadiazole, benzotriazole, and benzothiophene. From the viewpoint of the dielectric properties of the cured product, the aromatic ring can be an aromatic hydrocarbon ring or a fused polycyclic aromatic hydrocarbon ring. From the viewpoint of dielectric constant and dielectric tangent, the aromatic ring can be, for example, fluorene or indene; or it can be indene. When vinylphenyl monomers contain indene, cured products tend to exhibit lower dielectric constants and dielectric tangents.

[0043] The aromatic ring, aromatic hydrocarbon rings, aromatic heterocycles, and fused polycyclic aromatic hydrocarbon rings, as well as the specifically listed rings, can all be substituted or unsubstituted. Substituents used in substitution include, for example, alkyl groups, alkenyl groups, aryl groups, heteroaryl groups, and monovalent groups formed by two or more bonds of these selections. The number of carbon atoms in alkyl and alkenyl groups can be 1–18, 2–12, or 3–6. The number of carbon atoms in aryl and heteroaryl groups can be 2–30, 6–20, or 9–15. Monovalent groups include, for example, alkylaryl groups, arylalkyl groups, and alkylarylalkyl groups.

[0044] Monomers containing vinylphenyl groups may include, for example, monomers having one to three vinylphenyl groups having an aromatic ring and being directly or via a linker group bonded to the aromatic ring; monomers having one to three vinylphenyl groups having an aromatic hydrocarbon ring and being directly or via a linker group bonded to the aromatic hydrocarbon ring; or monomers having one to three vinylphenyl groups having an inden ring and being directly or via a linker group bonded to the inden ring. In these forms, the aromatic ring, aromatic hydrocarbon ring, and inden ring may be substituted or unsubstituted, respectively. Examples of substituents are as described above. Linker groups may be, for example, groups selected from the group consisting of alkylene (e.g., having 1 to 5 carbon atoms), oxy group, thio group, sulfonyl group, sulfinyl group, carbonyl group, carbonyloxy group, imino group, and divalent groups formed by two or more of these selected groups. Furthermore, "having an aromatic ring and one to three vinylphenyl groups bonded to the aromatic ring via a linker" means "having an aromatic ring and one to three vinylphenyl groups bonded to the aromatic ring and bonded to the linker".

[0045] Monomers containing vinylphenyl groups can replace aromatic rings, or together with aromatic rings, have saturated or unsaturated aliphatic hydrocarbon groups, saturated or unsaturated alicyclic hydrocarbon groups, heteroatom-containing groups, etc.

[0046] The weight-average molecular weight (Mw) of the vinylphenyl-containing monomer, from a formability and operability point of view, is, for example, 200–2,000, 200–1,000, 200–800, 250–750, or 300–700. In this disclosure, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) refer to values ​​measured using gel permeation chromatography (GPC) with polystyrene as a standard. Specifically, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) in this disclosure can be measured according to the methods described in the examples.

[0047] In some embodiments, the vinylphenyl compound comprises a compound represented by the following formula (b1).

[0048] [Chemistry 3]

[0049]

[0050] (where X) b1 The symbols represent organic groups, where B independently represents a group containing a vinylphenyl group, l represents an integer from 1 to 5, R independently represents a substituent, and m represents an integer from 0 to 5.

[0051] The organic group may be a group containing at least one carbon atom, for example, it may be a group comprising at least one group selected from the group consisting of saturated aliphatic hydrocarbon group, unsaturated aliphatic hydrocarbon group, saturated alicyclic hydrocarbon group, unsaturated alicyclic hydrocarbon group, aromatic hydrocarbon ring group, and aromatic heterocyclic group. The organic group may further comprise or not comprise heteroatoms. The organic group may, for example, be an aromatic hydrocarbon ring group or an aromatic heterocyclic group; or it may be an aromatic hydrocarbon ring group. Examples of aromatic hydrocarbon rings in aromatic hydrocarbon ring groups and aromatic heterocycles in aromatic heterocyclic groups are as described above.

[0052] l can be 1 to 3. A vinylphenyl-containing monomer may, for example, include compounds in formula (b1) where l is 2, and may further include at least one selected from the group consisting of compounds with l of 1 and l of 3; or, it may include compounds with l of 2, compounds with l of 1, and compounds with l of 3. When a vinylphenyl-containing monomer includes multiple compounds represented by formula (b1), the average value of l in the compounds represented by formula (b1) is, for example, 1.2 to 2.8, 1.4 to 2.7, or 1.6 to 2.6.

[0053] Examples of substituents represented by R include alkyl, alkenyl, aryl, heteroaryl, and monovalent groups formed by two or more bonds of these selections. The number of carbon atoms in alkyl and alkenyl groups can be 1–18, 2–12, or 3–6. The number of carbon atoms in aryl and heteroaryl groups can be 2–30, 6–20, or 9–15. Examples of monovalent groups include alkylaryl, arylalkyl, and alkylarylalkyl. m can be 0–2, or 0 or 1. When the monomer containing vinylphenyl comprises multiple compounds represented by formula (b1), the average value of m in the compounds represented by formula (b2) is, for example, 0.0–1.8, 0.0–1.6, or 0.0–1.4. In some embodiments, the average value of m can exceed 0.0, 0.1 or more, 0.5 or more, or 1.0 or more.

[0054] In some embodiments, the vinylphenyl compound comprises a compound represented by formula (b2) below. When the vinylphenyl compound comprises a compound represented by formula (b2) below, superior resistance to tracking is tended to be obtained.

[0055] [Chemistry 4]

[0056]

[0057] (where X) b2 B represents an aromatic hydrocarbon cyclic group. p Each of the following bases is represented independently by the following formula (Ph), where L represents a direct bond or linking base, l represents an integer from 1 to 3, R represents a substituent, and m represents an integer from 0 to 3.

[0058] [Chemistry 5]

[0059]

[0060] (In the formula, * indicates the location of the bond.)

[0061] Examples of aromatic hydrocarbon rings in aromatic hydrocarbon cyclic groups are as described above. X b2 For example, it could be a fused polycyclic aromatic hydrocarbon ring group.

[0062] Examples of linking groups are as described above. Linking groups can be, for example, alkylene groups (with, for example, 1 to 5 carbon atoms) or methylene groups. Furthermore, L signifies "direct bonding," meaning X... b2 With B p Direct bonding. This is also the case in descriptions such as "L is a direct bonding" in this disclosure.

[0063] The vinylphenyl monomer may, for example, include compounds in formula (b2) where l is 2, and may further include at least one selected from the group consisting of compounds where l is 1 and compounds where l is 3; or, it may include compounds where l is 2, compounds where l is 1, and compounds where l is 3. When the vinylphenyl monomer includes multiple compounds represented by formula (b2), the average value of l in the compounds represented by formula (b2) is, for example, 1.2–2.8, 1.4–2.7, or 1.6–2.6.

[0064] Examples of substituents represented by R are listed in formula (b1). m can be 0 to 2, or 0 or 1. When the vinylphenyl-containing monomer comprises multiple compounds represented by formula (b1), the average value of m in the compounds represented by formula (b2) is, for example, 0.0 to 1.8, 0.0 to 1.6, or 0.0 to 1.4. In some embodiments, the average value of m can exceed 0.0, 0.1 or more, 0.5 or more, or 1.0 or more.

[0065] From the viewpoint of obtaining a cured material with low dielectric constant and low dielectric tangent, the base represented by formula (Ph) may include the base represented by formula (p).

[0066] In some embodiments, the vinylphenyl compound comprises a compound represented by formula (b3) below. When the vinylphenyl compound comprises a compound represented by formula (b3) below, it tends to obtain superior resistance to tracking and also achieves a lower dielectric constant and dielectric tangent.

[0067] [Chemistry 6]

[0068]

[0069] (In the formula, B) hb Each of the following independently represents a hydrogen atom, a group represented by the following formula (Ba), or a group represented by the following formula (Bz), and at least one B hb It is a basis represented by the following formula (Bz).

[0070] [Chemistry 7]

[0071]

[0072] (In the formula, A represents an alkyl group, and * represents the bond position.)

[0073] [Chemistry 8]

[0074]

[0075] (In the formula, * indicates the location of the bond.)

[0076] The number of carbon atoms in the alkyl group represented by A is, for example, 1 to 6.

[0077] The vinylphenyl-containing monomer comprises compounds having two groups represented by formula (Bz) in formula (b3), and may further comprise at least one selected from the group consisting of compounds having one group and compounds having three groups; or, may comprise compounds having two groups, one group, and three groups represented by formula (Bz). When the vinylphenyl-containing monomer comprises multiple compounds represented by formula (b3), the average number of groups represented by formula (Bz) in the compounds represented by formula (b3) is, for example, 1.2 to 2.8, 1.4 to 2.7, or 1.6 to 2.6. In the compounds represented by formula (b3), the average number of groups represented by formula (Ba) is, for example, 0.0 to 1.8, 0.0 to 1.6, or 0.0 to 1.4. In some implementations, the average number of bases represented by formula (Ba) may exceed 0.0, 0.1 or more, 0.5 or more, or 1.0 or more.

[0078] From the viewpoint of obtaining cured products with low dielectric constant and low dielectric tangent, the group represented by formula (Bz) may include a group represented by formula (Bz) in which the position of the vinyl group bonded to the benzene ring is paraposition relative to the position of the methylene group bonded to the benzene ring.

[0079] There are no particular limitations on the method for synthesizing vinylphenyl monomers. For example, when the vinylphenyl monomer is a compound represented by formula (b2), a method can be listed that involves reacting an aromatic hydrocarbon ring with styrene having a halogenated methyl group in the presence of a basic compound. When synthesized by such a method, the compound represented by formula (b2) has a methylene group as a linking group.

[0080] Examples of styrene containing halogenated methyl groups include o-chloromethylstyrene, m-chloromethylstyrene, and p-chloromethylstyrene; these can be used alone or in combination of two or more. Examples of basic compounds include alkali metal hydroxides and alkali metal alkoxides. A phase transfer catalyst can be used in this reaction. Examples of phase transfer catalysts include tetrabutylphosphonium bromide and tetra-n-butylammonium bromide. The reaction can be carried out in a solvent. The reaction can be carried out under heating and stirring conditions. Polymerization inhibitors can be added to the reaction system. The obtained product can be purified as needed by known methods such as concentration, reprecipitation, and washing.

[0081] (Contains vinylphenyl polymer)

[0082] In some embodiments, the vinylphenyl compound comprises a vinylphenyl-containing polymer. The vinylphenyl compound may comprise a polymer having two vinylphenyl groups; or it may comprise a polymer having three or more vinylphenyl groups. Examples of vinylphenyl-containing polymers include polymers having a hydrocarbon chain backbone and containing vinylphenyl groups; polymers having a phenolic resin-type backbone and containing vinylphenyl groups. Examples of polymers having a hydrocarbon chain backbone include polyolefins, vinyl polymers, acrylic polymers, and polydicyclopentadiene. Examples of phenolic resins include novolacic phenolic resins, aralkyl phenolic resins, dicyclopentadiene phenolic resins, and triphenylmethane phenolic resins, among which resins may substitute for the phenol structure or contain a naphthol structure based on the phenol structure.

[0083] From the viewpoint of formability and handling, the weight average molecular weight (Mw) of the vinylphenyl-containing polymer is, for example, 300–50,000, 500–30,000, or 1,000–10,000. From the viewpoint of improving the flowability of the encapsulation material and obtaining good formability, the weight average molecular weight (Mw) can be 5,000 or less, or 2,500 or less.

[0084] In some embodiments, the vinylphenyl compound comprises a polymer having the structure represented by the following formula (B1).

[0085] [Chemistry 9]

[0086]

[0087] (where X) B1 The symbol represents an organic group, B represents a group containing a vinylphenyl group, R represents a substituent independently, and m represents an integer from 0 to 10. * indicates the bond position with other atoms.

[0088] The organic group may be a group containing at least one carbon atom, for example, it may be a group comprising at least one group selected from the group consisting of saturated aliphatic hydrocarbon groups, unsaturated aliphatic hydrocarbon groups, saturated alicyclic hydrocarbon groups, unsaturated alicyclic hydrocarbon groups, aromatic hydrocarbon cyclic groups, and aromatic heterocyclic groups. The organic group may further include or exclude a group containing a heteroatom.

[0089] Examples of substituents represented by R include alkyl groups with 1 to 5 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl. When the number of carbon atoms is 3 or more, the alkyl group can be a straight-chain alkyl group. m represents, for example, an integer from 0 to 5, an integer from 0 to 2, or 0.

[0090] In some embodiments, the vinylphenyl compound comprises a polymer represented by formula (B2) below. When the vinylphenyl compound comprises a polymer represented by formula (B2) below, superior resistance to tracking is tended to be obtained.

[0091] [Chemistry 10]

[0092]

[0093] (where X) B2 Each of the following independently represents a benzene ring or a naphthalene ring, and each of the following independently represents an organogroup: B p Each of the following groups independently represents the base represented by the following formula (Ph), each of the groups L independently represents the direct bond or linking base, each of the groups R independently represents the substituent, each of the groups m independently represents an integer from 0 to 5, and each of the groups n represents a number from 2 to 10.

[0094] [Chemistry 11]

[0095]

[0096] (In the formula, * indicates the location of the bond.)

[0097] The organic group can be a group containing at least one carbon atom, such as alkylene groups like methylene and ethylene group; cycloalkylene groups like tetrahydrodicyclopentadiene; arylalkylene groups like phenylmethylene group; and divalent organic groups containing alkylene and arylene groups.

[0098] From the viewpoint of obtaining a cured material with low dielectric constant and low dielectric tangent, the base represented by formula (Ph) may include the base represented by formula (p).

[0099] Examples of linking groups include alkylene groups (with, for example, 1 to 5 carbon atoms), oxy groups, thio groups, sulfonyl groups, sulfinyl groups, carbonyl groups, carbonyloxy groups, imino groups, and divalent groups formed by two or more of these selections.

[0100] Examples of substituents represented by R are listed in formula (B1). Substituents can be alkyl groups having 1 to 5 carbon atoms, or methyl groups. When there are 3 or more carbon atoms, the alkyl group can be a straight-chain alkyl group. m can independently represent, for example, an integer from 0 to 4, an integer from 0 to 2, or 0.

[0101] n is the average value of the polymer represented by formula (B2). n can be a number from 2 to 8, or from 3 to 5.

[0102] In some embodiments, the vinylphenyl compound may comprise at least one selected from the group consisting of polymers represented by the following formula.

[0103] [Chemistry 12-1]

[0104]

[0105] [Chemistry 12-2]

[0106]

[0107] (In each formula, B) p Each group independently represents a group represented by the formula (Ph), each L independently represents a directly bonded or linked group, and n represents a value from 2 to 10. The benzene ring and naphthalene ring can each independently have substituents at substituted positions.

[0108] From the viewpoint of obtaining a cured material with low dielectric constant and low dielectric tangent, the base represented by formula (Ph) may include the base represented by formula (p).

[0109] Examples of linker groups are listed in formula (B2). From the viewpoint of obtaining good resistance to tracking, the linker group may contain an oxygen group. For example, the linker group may contain a methyleneoxy group; in this case, the polymer represented by the formula comprises a group consisting of B... p The structure represented by -CH2-O-*.

[0110] When the benzene ring and naphthalene ring in the various formulas have substituents, examples of substituents are listed as R in formula (B1). The substituents can be alkyl groups having 1 to 5 carbon atoms, and can be methyl groups. When there are 3 or more carbon atoms, the alkyl group can be a straight-chain alkyl group. Alternatively, the benzene ring and naphthalene ring in the various formulas can be unsubstituted, or except for B.p It may not have any other substituents other than -L-*.

[0111] n is the average value of the polymer represented by the formula. For example, n can represent a value from 2 to 8, or a value from 3 to 5.

[0112] When a vinylphenyl compound contains at least one polymer selected from the group consisting of polymers represented by formula (B2-1) to polymers represented by formula (B2-11), it tends to readily obtain excellent resistance to tracking. When a vinylphenyl compound contains at least one polymer selected from the group consisting of polymers represented by formula (B2-3) and polymers represented by formula (B2-7), it tends to readily obtain a low dielectric constant and a low dielectric tangent. In particular, when a vinylphenyl compound contains a polymer represented by formula (B2-3), it tends to readily obtain an even lower dielectric constant and dielectric tangent.

[0113] In some embodiments, the vinylphenyl compound comprises a polymer represented by formula (B3-3), a polymer represented by formula (B3-7), or both.

[0114] [Chemistry 13]

[0115]

[0116] (In the formula, B) b Each of these can independently represent a base as indicated by the following formula (Bz), where n represents a number from 3 to 5.

[0117] [Chemistry 14]

[0118]

[0119] (In the formula, B) b Each of these can be independently represented by a base as shown in the following formula (Bz), where n represents a number from 3 to 5.

[0120] [Chemistry 15]

[0121]

[0122] (In the formula, * indicates the location of the bond.)

[0123] From the viewpoint of obtaining cured products with low dielectric constant and low dielectric tangent, the group represented by formula (Bz) may include the group represented by formula (Bz) and the position of the vinyl group bonded to the benzene ring is para relative to the position of the methylene group bonded to the benzene ring.

[0124] There are no particular limitations on the method for synthesizing polymers containing vinylphenyl groups. For example, when the polymer containing vinylphenyl groups is a compound represented by formula (B2), a method can be listed that involves reacting a phenolic resin with styrene having a halogenated methyl group in the presence of a basic compound. When synthesized by this method, the compound represented by formula (B2) has a methylene oxy group as a linking group.

[0125] Examples of styrene with halogenated methyl groups, basic compounds, and phase transfer catalysts are described above. The reaction can be carried out in a solvent. The reaction can be carried out under heating and stirring. A polymerization inhibitor may be added to the reaction system. The obtained product can be purified as needed by known methods such as concentration, reprecipitation, and washing.

[0126] Examples of phenolic resins include novolac-type phenolic resins, aralkyl-type phenolic resins, dicyclopentadiene-type phenolic resins, biphenyl-type phenolic resins, triphenylmethane-type phenolic resins, and resins in which the phenol structure is replaced or where a naphthol structure is contained in addition to the phenol structure. Commercially available phenolic resins can be used.

[0127] The weight-average molecular weight (Mw) of phenolic resins, from the viewpoint of moldability and handling of encapsulation materials, is, for example, 300–30,000, 500–10,000, or 1,000–5,000. The number-average molecular weight (Mn) of phenolic resins, from the viewpoint of moldability and handling, is, for example, 200–10,000, 300–5,000, or 400–2,000. The hydroxyl equivalent of phenolic resins, from the viewpoint of the resistance to tracking of the cured product, is, for example, 50 g / eq–500 g / eq, 100 g / eq–400 g / eq, or 150 g / eq–300 g / eq. The hydroxyl equivalent can be measured according to the method of Japanese Industrial Standards (JIS) K 0070:1992.

[0128] (content)

[0129] The encapsulation material may contain only one vinylphenyl compound, or it may contain two or more vinylphenyl compounds. Based on the mass of the encapsulation material (however, excluding the mass of filler material if the encapsulation material contains filler material), the content of the vinylphenyl compound is, for example, 10% to 100% by mass, 15% to 80% by mass, or 20% to 60% by mass. When the content of the vinylphenyl compound is 10% by mass or more, the cured product tends to exhibit better resistance to tracking. The content of the vinylphenyl compound is, for example, 50% by mass or less, 40% by mass or less, or 35% by mass or less. If the addition of any components such as a polymerization initiator or colorant is considered, the content of the vinylphenyl compound may be less than 100% by mass.

[0130] When the vinylphenyl compound contains a vinylbenzyl compound, the content of the vinylbenzyl compound, based on the mass of the vinylphenyl compound, is, for example, 70% by mass or more, 80% by mass or more, or 90% by mass or more. The upper limit for the content of the vinylbenzyl compound can be 100% by mass. When the vinylphenyl compound contains a vinylbenzyl ether compound, the content of the vinylbenzyl ether compound, based on the mass of the vinylphenyl compound, is, for example, 70% by mass or more, 80% by mass or more, or 90% by mass or more. The upper limit for the content of the vinylbenzyl ether compound can be 100% by mass. When the encapsulation material contains a vinylbenzyl ether compound, the resistance to tracking tends to improve.

[0131] When a vinylphenyl compound contains both a vinylphenyl-containing monomer and a vinylphenyl-containing polymer, the content of the vinylphenyl-containing monomer, based on the mass of the vinylphenyl compound, is, for example, 5%–95% by mass, 50%–90% by mass, or 70%–88% by mass. The content of the vinylphenyl-containing polymer, based on the mass of the vinylphenyl compound, is, for example, 5%–95% by mass, 10%–50% by mass, or 12%–30% by mass.

[0132] When the encapsulation material contains vinyl compounds, the total content of vinylphenyl compounds and vinyl compounds is, for example, 70%–100% by mass, 80%–99% by mass, or 90%–98% by mass, based on the mass of the encapsulation material (however, excluding the mass of the filler material when the encapsulation material contains filler material). When the total content is 70% by mass or more, the cured product tends to exhibit better resistance to tracking and lower molding shrinkage. Taking into account the addition of any components such as polymerization initiators and colorants, the total content can be less than 100% by mass.

[0133] When the encapsulation material contains vinyl compounds, the content of vinyl phenyl compounds is, for example, 10% to 90% by mass, 15% to 80% by mass, or 20% to 60% by mass, based on the total mass of vinyl phenyl compounds and vinyl compounds. When the content of vinyl phenyl compounds is 55% by mass or more, the cured product tends to exhibit better resistance to tracking. From the viewpoint of obtaining the full effect brought by vinyl compounds, the content of vinyl phenyl compounds can be 90% by mass or less, or 50% by mass or less, 40% by mass or less, or 35% by mass or less.

[0134] [Compounds containing vinyl bonds]

[0135] The encapsulation material may further contain a vinyl compound. A vinyl compound is a compound having at least one vinyl bond. The vinyl bond may be a free-radical polymerizable carbon-carbon unsaturated bond. Examples of vinyl compounds include compounds having a vinyl bond as a monovalent group represented by CH2=CH-*, compounds having a vinyl bond as a divalent group represented by *-CH=CH-*, or compounds having both the monovalent and divalent groups. For example, a vinyl compound may have 1 to 20, 1 to 15, or 1 to 10 vinyl bonds. The vinyl compound may consist of one vinyl compound or may contain two or more vinyl compounds. The vinyl compound does not contain a vinylphenyl group. When the encapsulation material contains a vinyl compound, a cured product with good curability and low molding shrinkage can be obtained.

[0136] Vinyl compounds can be monomers or polymers capable of free radical polymerization. Vinyl compounds, for example, comprise monomers having vinyl bonds. In this disclosure, monomers having vinyl bonds are sometimes referred to as "vinyl-bonded monomers." Vinyl compounds, for example, comprise polymers having vinyl bonds. In this disclosure, polymers having vinyl bonds are sometimes referred to as "vinyl-bonded polymers."

[0137] In some embodiments, the vinyl compound comprises a compound having two vinyl bonds. The compound having two vinyl bonds may be a monomer or a polymer. In some embodiments, the vinyl compound comprises a compound having three or more vinyl bonds. The compound having three or more vinyl bonds may be a monomer or a polymer.

[0138] Examples of monomers containing vinyl bonds include: ethylene, propylene, butadiene, isoprene, dimethylbutadiene, chloroprene, 1,3-pentadiene, and other olefin compounds; methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tetra(meth)acrylate, and bisphenol A diglycidyl ether. (meth)acrylate compounds such as di(meth)acrylate; (meth)acrylic acid ester compounds such as (meth)acrylic acid, itaconic acid, maleic acid, and fumaric acid; carboxyl group-containing vinyl compounds such as (meth)acrylic acid, itaconic acid, maleic acid, and fumaric acid; ester group-containing vinyl compounds such as vinyl acetate and vinylpropionate; halogen-containing vinyl compounds such as vinyl chloride and vinylidene chloride; and nitrile group-containing vinyl compounds such as acrylonitrile and methacrylonitrile.Acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, and other amide group-containing vinyl compounds; maleimide compounds such as maleimide, N-phenylmaleimide, and 4,4'-diphenylmethane bismaleimide; and nitrogen-containing vinyl compounds other than those mentioned above, such as N-vinylpyrrolidone, 1-vinylimidazole, and vinylcarbazole.

[0139] Examples of vinyl-bonded polymers include: polymers with a hydrocarbon backbone containing vinyl bonds; polymers with a phenolic resin-type backbone containing vinyl bonds; and polyamides, polyamide imides, or polyimides containing vinyl bonds. Examples of polymers with a hydrocarbon backbone and phenolic resins are the same as those listed for vinyl-phenyl-containing polymers.

[0140] (maleimide compound)

[0141] In some embodiments, the vinyl compound comprises a compound having a maleimide group. In this disclosure, a compound having a maleimide group is sometimes referred to as a "maleimide compound." A maleimide compound is a compound having at least one maleimide group. A maleimide compound has, for example, 1 to 20, 1 to 15, or 1 to 10 maleimide groups. A maleimide compound may consist of one maleimide compound or may contain two or more maleimide compounds. When the encapsulation material contains a maleimide compound, better curability and improved heat resistance can be obtained, and in particular, a cured product with low molding shrinkage can be obtained.

[0142] The maleimide group can be represented by the following formula. * indicates the bonding position with other atoms.

[0143] [Chemistry 16]

[0144]

[0145] In some embodiments, the maleimide compound comprises a compound having two maleimide groups. In this disclosure, a compound having two maleimide groups is sometimes referred to as a "bismaleimide".

[0146] In some embodiments, the vinyl compound comprises a compound represented by the following formula (m1).

[0147] [Chemistry 17]

[0148]

[0149] (where X) m (This indicates an organic group; M represents maleimide.)

[0150] The organic group may be a group containing at least one carbon atom, for example, it may be a group containing at least one selected from the group consisting of saturated aliphatic hydrocarbon groups, unsaturated aliphatic hydrocarbon groups, saturated alicyclic hydrocarbon groups, unsaturated alicyclic hydrocarbon groups, aromatic hydrocarbon cyclic groups, and aromatic heterocyclic groups. The organic group may further contain or not contain a group containing a heteroatom. From the viewpoint of improving the heat resistance of the cured product, the organic group is preferably a group containing at least one selected from the group consisting of aromatic hydrocarbon cyclic groups and aromatic heterocyclic groups.

[0151] In some embodiments, the vinyl compound may comprise at least one of the groups selected from compounds represented by the following formulas.

[0152] [Chemistry 18]

[0153]

[0154] (In each formula, M represents maleimide group, L...) 2 R represents a direct bond or linker base. ha Each group independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n represents an integer from 1 to 8. Each benzene ring may independently have substituents at substituted positions.

[0155] As L 2 Examples of the linking groups may include alkylene groups (with 1 to 5 carbon atoms, for example), oxy groups, thio groups, sulfonyl groups, sulfinyl groups, carbonyl groups, carbonyloxy groups, imino groups, and groups represented by the following formula (m-2L). Examples of alkylene groups with 1 to 5 carbon atoms include straight-chain alkylene groups such as methylene, 1,2-dimethylene, 1,3-trimethylene, 1,4-tetramethylene, and 1,5-pentamethylene, as well as branched alkylene groups such as isopropylene, isobutylene, and tert-butylene.

[0156] [Chemistry 19]

[0157]

[0158] (where L) 2L Indicates a direct bond or a linking group. Each benzene ring can independently have substituents at substituted positions. * indicates a bond position.

[0159] As L 2L Examples of linking groups include alkylene groups (e.g., 1-5 carbon atoms), oxygen groups, thio groups, sulfonyl groups, sulfinyl groups, carbonyl groups, carbonyloxy groups, imino groups, etc. Examples of alkylene groups with 1-5 carbon atoms are similar to L... 2 The same as those listed in the document.

[0160] In formulas (m-1), (m-2), and (m-2L), each benzene ring is independently unsubstituted, or may have a substituent at a substituted position. Examples of substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and n-pentyl. The substituent may be an alkyl group having 1 to 3 carbon atoms, or it may be methyl.

[0161] In the formula (m-3), R ha Examples of alkyl groups having 1 to 5 carbon atoms are as described above. n represents, for example, an integer from 1 to 6, an integer from 1 to 3, or an integer from 4 to 6.

[0162] When a vinyl compound contains at least one compound selected from the group consisting of compounds represented by formula (m-1) and compounds represented by formula (m-2), it tends to readily acquire excellent heat resistance. The vinyl compound may contain compounds represented by formula (m-2) and L 2 It is a compound represented by a group of formula (m-2L). Vinyl compounds may include compounds represented by formula (m-3) where n is 4 to 8.

[0163] In some embodiments, the vinyl compound comprises a polymer having maleimide groups. In this disclosure, polymers having maleimide groups are sometimes referred to as "maleimide-containing polymers." The vinyl compound may comprise a polymer having two maleimide groups; or, it may comprise a polymer having three or more maleimide groups. Examples of maleimide compounds include: polymers having a hydrocarbon backbone and maleimide groups; polymers having a phenolic resin-type backbone and maleimide groups; polyamides, polyamide-imides, or polyimides having maleimide groups, etc. Examples of polymers with hydrocarbon backbones and phenolic resins are the same as those listed in the vinylphenyl-containing polymers.

[0164] In some embodiments, the maleimide compound comprises a polymer represented by the following formula (M1).

[0165] [Chemistry 20]

[0166]

[0167] (where X) M Each group independently represents a benzene ring or a naphthalene ring; each Y group independently represents an organic group; each M group represents a maleimide group; each L group independently represents a direct bond or a linking group; each R group independently represents a substituent; each m group independently represents an integer from 0 to 5; and each n group represents a number from 2 to 10.

[0168] The organic group can be a group containing at least one carbon atom, such as alkylene groups like methylene and ethylene; cycloalkylene groups like tetrahydrodicyclopentadiene; arylalkylene groups like phenylmethylene; and divalent organic groups containing alkylene and arylene groups.

[0169] Examples of linking groups include alkylene groups (with, for example, 1 to 5 carbon atoms), oxy groups, thio groups, sulfonyl groups, sulfinyl groups, carbonyl groups, carbonyloxy groups, imino groups, and divalent groups formed by two or more of these selections.

[0170] Examples of substituents represented by R include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and n-pentyl. Substituents can be alkyl groups having 1 to 3 carbon atoms or methyl groups. m can independently represent, for example, an integer from 0 to 4, an integer from 0 to 2, or 0.

[0171] n is the average value of the polymer represented by formula (M). n can represent, for example, a number from 2 to 8, or a number from 3 to 5.

[0172] In some embodiments, the maleimide compound may comprise at least one polymer selected from the group consisting of polymers represented by the following formulas. When the vinyl compound comprises at least one polymer selected from the group consisting of polymers represented by the following formulas, excellent heat resistance is readily obtained.

[0173] [Chemistry 21]

[0174]

[0175] (In each formula, M represents a maleimide group, L independently represents a direct bonding or linking group, and n represents a number from 2 to 10. The benzene ring and naphthalene ring can each independently have substituents at substituted positions.)

[0176] When the benzene ring and naphthalene ring in each formula have substituents, the examples of substituents are the same as those listed under R in formula (M1). The substituents can be alkyl groups having 1 to 3 carbon atoms, or they can be methyl groups. Alternatively, the benzene ring and naphthalene ring in each formula can be unsubstituted, or they can be without any substituents other than ML-*.

[0177] n is the average value of the polymer represented by each formula. For example, n can represent a number from 2 to 8, or a number from 3 to 5.

[0178] Specific examples of maleimide compounds include bis(4-maleimidephenyl)methane, polyphenylmethane maleimide, bis(4-maleimidephenyl) ether, bis(4-maleimidephenyl) sulfone, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, m-phenylene bismaleimide, 2,2-bis(4-(4-maleimidephenoxy)phenyl)propane, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane, 1,3-bis(3-maleimidephenoxy)benzene, 1,3-bis(4-maleimidephenoxy)benzene, polyphenylmethane maleimide, and other phenolic varnish-type maleimide compounds and aralkyl-type maleimide compounds. Maleimide compounds include, for example, at least one selected from the group consisting of 2,2-bis(4-(4-maleimidephenoxy)phenyl)propane, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane and polyphenylmethane maleimide.

[0179] Commercially available products can be used as maleimide compounds. Examples of commercially available products include "BMI-80" (2,2-bis[4-(4-maleimidephenoxy)phenyl]propane), "BMI-1000, BMI-1000H, BMI-1100, BMI-1100H" (all 4,4'-diphenylmethane bismaleimide), and "BMI-2000, BMI-2300" (both phenylmethane maleimide) manufactured by Daiwa Chemical Industries, Ltd. maleimide), "BMI-3000, BMI-3000H" (both m-phenylene bismaleimide), "BMI-4000" (bisphenol A diphenyl ether bismaleimide), "BMI-5100" (3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide), "BMI-7000, BMI-7000H" (both 4-methyl-1,3-phenylene bismaleimide), "BMI-TMH" (1,6'-bismaleimide-(2,2,4-trimethyl)hexane); Designer Molecules Products manufactured by Inc. include “BMI-2500, BMI-2560, BMI-3000, BMI-5000, BMI-6100”; “NE-X470S” by DIC Corporation; and “MIR-3000-70MT” by Nippon Kayaku Co., Ltd.

[0180] (content)

[0181] When the encapsulation material contains a vinyl compound, it may contain only one vinyl compound or two or more vinyl compounds. The content of the vinyl compound is based on the mass of the encapsulation material (however, excluding the mass of the filler material if the encapsulation material contains filler material), for example, 10% to 90% by mass, 20% to 80% by mass, or 30% to 75% by mass. When the content is 10% by mass or more, it tends to be easier to obtain the full effect of the vinyl compound. The content of the vinyl compound may be 40% by mass or more, 50% by mass or more, 55% by mass or more, or 60% by mass or more. When the content of the vinyl compound is 90% by mass or less, it tends to be easier to obtain the improved heat resistance effect of the vinylphenyl compound.

[0182] When the encapsulation material contains vinyl compounds, the content of the vinyl compounds is based on the total mass of the vinyl phenyl compound and the vinyl compound, for example, 10% to 90% by mass, 20% to 85% by mass, or 30% to 80% by mass. When the content is 10% by mass or more, it tends to be easier to obtain the full effect of the vinyl compounds. The content of vinyl compounds can be 40% by mass or more, or 50% by mass or more. When the content of vinyl compounds is 90% by mass or less, it tends to be easier to obtain the improved heat resistance effect of the vinyl phenyl compound.

[0183] When a vinyl compound contains a maleimide compound, the content of the maleimide compound is based on the mass of the vinyl compound, for example, 70% by mass or more, 80% by mass or more, or 90% by mass or more. The upper limit for the content of the maleimide compound can be 100% by mass.

[0184] When the encapsulation material contains a maleimide compound, it may contain only one maleimide compound, or it may contain two or more maleimide compounds. The content of the maleimide compound is based on the mass of the encapsulation material (however, excluding the mass of the filler material if the encapsulation material contains filler material), for example, 10% to 90% by mass, 20% to 80% by mass, or 30% to 75% by mass. When the content of the maleimide compound is 10% by mass or more, the cured product tends to exhibit a smaller molding shrinkage rate. In particular, from the viewpoint of reducing molding shrinkage, the content of the maleimide compound can be 40% by mass or more, 50% by mass or more, 55% by mass or more, or 60% by mass or more. When the content of the maleimide compound is 90% by mass or less, the improved heat resistance effect of the vinylphenyl compound tends to be more easily obtained.

[0185] When the encapsulation material contains maleimide compounds, the content of the maleimide compounds is based on the total mass of the vinylphenyl compound and the maleimide compound, for example, 10% to 90% by mass, 20% to 85% by mass, or 30% to 80% by mass. When the content of the maleimide compound is 10% by mass or more, the cured product tends to exhibit a smaller molding shrinkage rate. In particular, from the viewpoint of reducing molding shrinkage rate, the content of the maleimide compound can be 40% by mass or more, 50% by mass or more, 60% by mass or more, or 70% by mass or more. When the content of the maleimide compound is 90% by mass or less, the improved heat resistance effect brought by the vinylphenyl compound tends to be more easily obtained.

[0186] When the encapsulation material contains a maleimide compound, from the viewpoint of dielectric properties, curability, formability and conductor adhesion, the ratio of the content of maleimide groups to the content of vinylphenyl groups in the encapsulation material (maleimide groups (mol) / vinylphenyl (mol)) can be, for example, 0.05 to 5.0, 0.20 to 3.0, or 0.30 to 1.0.

[0187] [Any ingredients]

[0188] The encapsulation material may contain any components. Examples of such components include vinyl compounds, free radical polymerization initiators, fillers, coupling agents, release agents, colorants, polymerization inhibitors, ion exchangers, flame retardants, stress relief agents, and various additives. In addition to the examples listed below, the encapsulation material may also contain various additives as needed.

[0189] (Free radical polymerization initiator)

[0190] The encapsulation material may contain a free radical polymerization initiator. When the encapsulation material is used for heat-based molding, the free radical polymerization initiator may be a thermal radical polymerization initiator that generates free radicals through heating. Examples of thermal radical polymerization initiators include organic peroxides such as peroxyketals and dialkyl peroxides, or azo compounds such as azobisbutyronitrile and azobispropionitrile.

[0191] Examples of organic peroxides include 1,1,3,3-tetramethylbutyl peroxyneodecanoate, di(4-t-butylcyclohexyl) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, cumyl peroxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, t-butylperoxyneodecanoate, and t-butylperoxyneodecanoate. peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, t-hexyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate peroxyneoheptanoate, t-amylperoxy-2-ethylhexanoate, di-t-butylperoxyhexahydroterephthalate, t-amyl peroxy-3,5,5-trimethylhexanoate, 3-hydroxy-1,1-dimethylbutylperoxyneodecanate1-Dimethylbutyl peroxyneodecanoate, t-amylperoxyneodecanoate, di(3-methylbenzoyl) peroxide, dibenzoyl peroxide, di(4-methylbenzoyl) peroxide, t-hexyl peroxyisopropylmonocarbonate, t-butyl peroxymalate, t-butyl peroxy-3,5,5-trimethylhexanoate peroxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di(3-methylbenzoylperoxy)hexane, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butyl peroxybenzoate, dibutylperoxytrimethyl adipate, t-amyl peroxyoctanoate Peroxyoctanoate, t-amyl peroxyisononanoate, t-amyl peroxybenzoate, etc.

[0192] Examples of azo compounds include 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis(1-acetoxy-1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 4,4'-azobis(4-cyanovalericacid), and 1,1'-azobis(1-cyclohexanecarbonitrile).

[0193] When the encapsulation material contains a free radical polymerization initiator, the encapsulation material may contain only one free radical polymerization initiator, or it may contain two or more free radical polymerization initiators. When the encapsulation material contains a free radical polymerization initiator, the content of the free radical polymerization initiator is based on the total mass of the vinyl phenyl compound and, if necessary, the vinyl compound (or, if the encapsulation material does not contain a vinyl compound, the mass of the vinyl phenyl compound; the same applies hereinafter), and may be 0.1% to 5% by mass, or 0.2% to 3% by mass. For example, when the encapsulation material does not contain a vinyl compound, the encapsulation material may contain a free radical polymerization initiator.

[0194] (Filling material)

[0195] Encapsulation materials may contain fillers. When encapsulation materials contain fillers, the properties of the cured product, such as the coefficient of thermal expansion, thermal conductivity, and elastic modulus, tend to improve. Examples of fillers include inorganic and organic fillers. In some embodiments, the encapsulation material contains inorganic fillers.

[0196] The average particle size of inorganic filler material can be 5 μm or larger. From the viewpoint of improving the filling performance of encapsulation materials, the average particle size of inorganic filler material can be 100 μm or smaller. For example, the average particle size of inorganic filler material can be 5 μm to 100 μm, 8 μm to 50 μm, or 10 μm to 30 μm.

[0197] The average particle size of inorganic filler materials can be determined by the following method: Prepare a thin-film sample from the encapsulation material or a cured product of the encapsulation material. Randomly select 100 inorganic filler material particles from an image obtained using a scanning electron microscope (SEM). Measure the major diameter of each particle and calculate their arithmetic mean. Use this value as the average particle size of the inorganic filler material.

[0198] There are no particular limitations on the types of inorganic fillers. Examples include fused silica, crystalline silica, and other forms of silica; alumina, zirconia, titanium dioxide, glass, talc, clay, and mica. Inorganic fillers can also be flame-retardant. Examples of flame-retardant inorganic fillers include aluminum hydroxide; magnesium hydroxide; composite metal hydroxides such as magnesium and zinc hydroxides; and zinc borate.

[0199] Inorganic filler materials may contain silicon dioxide from the perspective of reducing the coefficient of linear expansion. Inorganic filler materials may contain alumina from the perspective of high thermal conductivity. Examples of the forms of inorganic filler materials include powders, powder shaped into spherical beads, and fibers.

[0200] When the encapsulation material contains filler, it may contain only one type of filler or two or more fillers. Based on the mass of the encapsulation material (excluding the mass of the filler), the filler content is, for example, 100% to 2,000% by mass, 250% to 1,500% by mass, or 350% to 700% by mass. When the filler content is 100% by mass or more, the properties of the cured product, such as the coefficient of thermal expansion, thermal conductivity, and modulus of elasticity, tend to be further improved. When the filler content is 2,000% by mass or less, the viscosity increase of the encapsulation material is suppressed, the flowability tends to be further improved, and the formability tends to be better. Based on the volume of the encapsulation material, the filler content (excluding carbon black) is, for example, 50% to 90% by volume, 55% to 85% by volume, or 60% to 80% by volume. When the filler content is above 50% by volume, the properties of the cured material, such as the coefficient of thermal expansion, thermal conductivity, and elastic modulus, tend to improve further. When the filler content is below 90% by volume, the viscosity increase of the encapsulation material is suppressed, the flowability tends to be more improved, and the formability tends to be better.

[0201] (Coupling agent)

[0202] The encapsulation material may contain a coupling agent. When the encapsulation material contains a coupling agent, the adhesiveness of the cured product, or the adhesiveness between the resin component (vinylphenyl compound, vinyl compound, etc., if necessary) and the inorganic filler material, tends to improve. Examples of coupling agents include silane coupling agents, titanate coupling agents, aluminum chelate coupling agents, aluminum / zirconium coupling agents, etc. Silane coupling agents may include, for example, epoxy silane coupling agents, mercapto silane coupling agents, amino silane coupling agents, alkyl silane coupling agents, ureoyl silane coupling agents, vinyl silane coupling agents, (meth)acrylic acid silane coupling agents, disilazane coupling agents, etc. In this disclosure, when the encapsulation material contains a coupling agent, coupling agents having vinylphenyl groups are removed from the scope of said vinylphenyl compounds, and coupling agents having vinyl groups are removed from the scope of said vinyl compounds. That is, vinylphenyl compounds and vinyl compounds refer to compounds other than those corresponding to the coupling agent. When the encapsulation material contains mercapto-based or amino-based silane coupling agents, the adhesion of the cured product tends to increase. When the encapsulation material contains vinyl-based or (meth)acrylate-based silane coupling agents, the formability and strength of the cured product tend to increase.

[0203] Examples of silane coupling agents include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacrylate oxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidyl ether oxypropyltrimethoxysilane, γ-glycidyl ether oxypropylmethyldimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and N-phenyl-3- Aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-anilinepropyltrimethoxysilane, γ-anilinepropyltriethoxysilane, γ-(N,N-dimethyl)aminopropyltrimethoxysilane, γ-(N,N-diethyl)aminopropyltrimethoxysilane, γ-(N,N-dibutyl)aminopropyltrimethoxysilane, γ-(N-) γ-(N,N-dimethyl)aminopropyltriethoxysilane, γ-(N,N-diethyl)aminopropyltriethoxysilane, γ-(N,N-dibutyl)aminopropyltriethoxysilane, γ-(N-methyl)anilinepropyltriethoxysilane, γ-(N-ethyl)anilinepropyltriethoxysilane, γ-(N,N-dimethyl)aminopropylmethyldimethoxysilane, γ-(N,N-diethyl)aminopropylmethyldimethoxysilane, γ-(N... N-Dibutylaminopropylmethyldimethoxysilane, γ-(N-methyl)anilinepropylmethyldimethoxysilane, γ-(N-ethyl)anilinepropylmethyldimethoxysilane, N-(trimethoxysilanepropyl)ethylenediamine, N-(dimethoxymethylsilaneisopropyl)ethylenediamine, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, vinyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, etc.

[0204] When the encapsulation material contains a coupling agent, it may contain only one type of coupling agent, or it may contain two or more types of coupling agents. When the encapsulation material contains inorganic filler and coupling agent, the coupling agent content, based on the mass of the inorganic filler, is, for example, 1% to 50% by mass, 10% to 45% by mass, or 20% to 40% by mass. When the coupling agent content is 1% by mass or more, the adhesion of the cured product tends to increase. When the coupling agent content is 2% by mass or less, the formability of the cured product tends to increase.

[0205] (Mold release agent)

[0206] Encapsulation materials may contain mold release agents. When encapsulation materials contain mold release agents, it is easier to obtain good release properties from the mold (die) during molding. Examples of mold release agents include: carnauba wax; higher fatty acids such as montanic acid and stearic acid, and metal salts of higher fatty acids; ester waxes such as montanate; and polyolefin waxes such as oxidized polyethylene and non-oxidized polyethylene.

[0207] When the encapsulation material contains a release agent, it may contain only one type of release agent, or it may contain two or more types. When the encapsulation material contains a release agent, the release agent content is, for example, 0.01% to 10% by mass, 0.05% to 5% by mass, or 0.1% to 2% by mass, based on the total mass of the vinyl phenyl compound and, if necessary, the contained vinyl compound. When the release agent content is 0.01% by mass or more, sufficient release properties are tended to be obtained. When the release agent content is 10% by mass or less, better adhesion is tended to be obtained.

[0208] (Coloring agent)

[0209] Encapsulation materials may contain colorants. Examples of known colorants include carbon black, organic dyes, organic pigments, titanium dioxide, red lead, and red iron oxide. The content of the colorant can be appropriately selected based on the intended purpose. Colorants may also function as filler materials.

[0210] When the encapsulation material contains a colorant, the encapsulation material may contain only one colorant, or it may contain two or more colorants. When the encapsulation material contains a colorant, the content of the colorant is, for example, 0.01% to 10% by mass, or 0.1% to 5% by mass, based on the total mass of the vinyl phenyl compound and, if necessary, the vinyl compound contained therein.

[0211] (Polymerization inhibitor)

[0212] The encapsulation material may contain polymerization inhibitors. Examples of polymerization inhibitors include: phenolic compounds such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol; and hindered amine compounds.

[0213] (Ion exchanger)

[0214] Encapsulation materials may contain ion exchangers. When encapsulation materials contain ion exchangers, they tend to improve the moisture resistance and high-temperature storage characteristics of power semiconductor devices. Examples of ion exchangers include: hydrotalcite compounds; hydrated hydroxides of at least one element selected from the group consisting of magnesium, aluminum, titanium, zirconium, and bismuth. Ion exchangers may also function as filler materials. Encapsulation materials may contain only one type of ion exchanger, or they may contain two or more types of ion exchangers.

[0215] (Flame retardant)

[0216] Encapsulation materials may contain flame retardants. Examples of flame retardants include organic or inorganic compounds containing halogen, antimony, nitrogen, or phosphorus atoms, and metal hydroxides. Encapsulation materials may contain only one flame retardant or may contain two or more flame retardants.

[0217] (Stress reliever)

[0218] Encapsulation materials may contain stress-relieving agents. When encapsulation materials contain stress-relieving agents, they tend to reduce warpage and cracking in power semiconductor devices. Examples of stress-relieving agents include: silicone oil; thermoplastic elastomers such as silicone-based, styrene-based, olefin-based, polyurethane-based, polyester-based, polyether-based, polyamide-based, and polybutadiene-based elastomers; rubber particles such as natural rubber (NR), acrylonitrile butadiene rubber (NBR), acrylic rubber, polyurethane rubber, and silicone powder; and rubber particles with a core-shell structure such as methyl methacrylate-styrene-butadiene copolymer (MBS), methyl methacrylate-silicone resin copolymer, and methyl methacrylate-butyl acrylate copolymer (however, compounds belonging to vinylphenyl compounds or vinyl compounds are excluded). When encapsulation materials contain stress-relieving agents, they may contain only one type of stress-relieving agent or two or more types. Commercially available flexibility-improving agents can be used as stress-relieving agents.

[0219] [Relative Tracking Index (CTI) of Cured Materials]

[0220] In some implementations, the relative tracking index (CTI) of the cured material for packaging is measured according to JIS C2134:2021 (IEC60112), for example, above 530 V, above 550 V, above 580 V, or above 600 V. A higher CTI tends to improve the reliability of power semiconductor devices.

[0221] In this disclosure, the cured material used for measurement can be a disc-shaped cured material produced by transfer molding using an encapsulation material. The molding conditions are a mold temperature of 175°C, a molding time of 120 seconds, a molding pressure of 6.9 MPa, and the cured material has a diameter of 5 mm and a thickness of 3 mm. Measurement can be performed using a tracking resistance tester (e.g., Yamayo Testing Instruments Co., Ltd.'s "HAT-112-3"). Specifically, the number of measurements is n=5, and more than 50 drops of a 0.1% by mass aqueous solution of ammonium chloride are added to each cured material. The maximum voltage that will not damage any of the cured materials is measured.

[0222] Because vinylphenyl compounds have good curability, when encapsulation materials contain vinylphenyl compounds, cured products with high crosslinking density can be obtained, resulting in a larger CTI. Furthermore, the CTI of the cured product tends to increase when the vinylphenyl compound has a vinyl benzyl ether group; when the resin component (vinylphenyl compound, vinyl compound, etc.) forming the cured product has a high content of aromatic rings in its backbone; or when the carbon black content used as a colorant is low.

[0223] [Curved shrinkage rate]

[0224] In some embodiments, the molding shrinkage rate of the cured encapsulation material is, for example, less than 0.25%, less than 0.20%, less than 0.18%, or less than 0.15%. The smaller the shrinkage rate, the more likely it is to suppress the warpage of the power semiconductor device.

[0225] In this disclosure, the molding shrinkage rate (%) is measured by producing a disc-shaped cured material through transfer molding, using the dimensions of the cured material and the dimensions of the mold used for transfer molding. The molding conditions are: mold temperature 175°C, molding time 120 seconds, molding pressure 6.9 MPa, and the curing conditions are: heating temperature 175°C, heating time 6 hours. The dimensions of the disc-shaped cured material used for measurement are, for example, a diameter of approximately 80 mm × a thickness of approximately 4 mm. The molding shrinkage rate (%) can be obtained from the average value Rm (mm) of the surface diameter and the back diameter of the cured material, and the average value Rd (mm) of the mold inner diameter corresponding to the surface of the cured material and the mold inner diameter corresponding to the back diameter of the cured material, by the following formula.

[0226] Molding shrinkage rate (%) = (Rd - Rm) / Rd × 100

[0227] When the skeleton of the resin component (vinylphenyl compound, vinyl compound, etc.) that forms the cured product contains a high proportion of aromatic rings and the resin component is relatively rigid, the molding shrinkage rate tends to be smaller.

[0228] [Water absorption rate of the solidified material]

[0229] In some embodiments, the water absorption rate of the cured encapsulation material is, for example, less than 0.4%, less than 0.3%, less than 0.2%, or less than 0.1%. The lower the water absorption rate, the more likely it is to improve the reliability of the power semiconductor device.

[0230] In this disclosure, the water absorption rate (%) is measured by forming a disc-shaped cured material through transfer molding, subjecting the cured material to pressure cooking, and using the mass of the cured material before and after treatment. The molding conditions are a mold temperature of 175°C, a molding time of 120 seconds, and a molding pressure of 6.9 MPa, while the curing conditions are a heating temperature of 175°C and a heating time of 6 hours. The dimensions of the disc-shaped cured material used for measurement are, for example, a diameter of 50 mm × a thickness of 3 mm. The pressure cooking conditions are: pressure 2 atm (0.2 MPa), temperature 121°C, relative humidity 100%RH, and time 20 hours. The water absorption rate (mass %) is calculated by measuring the mass of the cured material before and after pressure cooking using the following formula.

[0231] Water absorption rate (mass%) = ((mass after treatment - mass before treatment) / mass before treatment) × 100

[0232] Unlike epoxy and phenolic resins, the polymerization of vinylphenyl compounds, and if necessary, vinyl compounds, does not produce hydroxyl groups. Therefore, the water absorption of the cured product can be kept low.

[0233] [Manufacturing Method of Packaging Materials]

[0234] There are no particular limitations on the manufacturing method of the encapsulation material. For example, methods include thoroughly mixing specific proportions of components using a mixer, followed by melt mixing, cooling, and pulverizing. Melt mixing can be performed using a kneader (e.g., a biaxial kneader), a roller (e.g., a mixing roller), or an extruder (e.g., an extruder). The melt mixing temperature is, for example, 70°C to 140°C, or 80°C to 130°C. The encapsulation material can be solid at room temperature and pressure (e.g., 25°C, atmospheric pressure). The shape of the solid encapsulation material is not particularly limited; examples include powder, granules, and tablets.

[0235] <Encapsulation Materials>

[0236] In some embodiments, the encapsulation material comprises a cured product obtained using the encapsulation material of the embodiment. The encapsulation material can be used to encapsulate power semiconductor components, power semiconductor devices, etc. The cured product can be manufactured, for example, by molding the encapsulation material and heating the resulting molded article. Heating conditions are, for example, at 150°C to 180°C for 2 to 16 hours.

[0237] <Power Semiconductor Devices>

[0238] A power semiconductor device may include, for example, a power semiconductor element and a package material of the embodiment that encapsulates at least a portion of the power semiconductor element. A power semiconductor device may be, for example, a power semiconductor module having a plurality of elements selected from the group consisting of power semiconductor elements and power semiconductor devices, and a package material of the embodiment that encapsulates at least a portion of the plurality of elements. A power semiconductor module may include electronic components other than power semiconductor elements, electronic component devices other than power semiconductor devices, etc.

[0239] Examples of power semiconductor devices include diodes; thyristors; IGBTs (Insulated Gate Bipolar Transistors), Si-based MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), SiC-based MOSFETs, and other transistors. Materials used in power semiconductor devices include Si (silicon), SiC (silicon carbide), and GaN (gallium nitride). The packaging material of the described embodiment is suitable as a packaging material for power semiconductor devices and power semiconductor devices using SiC as the material.

[0240] Examples of electronic components include: active components or parts such as diodes, transistors, integrated circuits, and relays; passive components or parts such as resistors, capacitors, and coils; connectors, support components, terminals, and switches. Applications of power semiconductor devices include: automobiles, trams, wind power generation, solar power generation, and industrial motor equipment; PCs (personal computers), smartphones, air conditioners, televisions, and other household appliances. Power semiconductor devices can be power semiconductor modules containing semiconductor components other than power semiconductor elements, such as diodes, transistors, thyristors, photoelectric conversion elements, sensors, and ICs (integrated circuits); they can also be intelligent power modules.

[0241] Semiconductor devices can take the form of known packages, such as through-hole packages and surface-mount packages. Surface-mount packages include leadframe packages and solder ball packages. Specific examples include SIP (Single Inline Package), DIP (Dual Inline Package), PGA (Pin Grid Array), PLCC (Plastic Leaded Chip Carrier), QFP (Quad Flat Package), SOP (Small Outline Package), SOJ (Small Outline J-lead package), TSOP (Thin Small Outline Package), and TQFP (Thin Quad Flat Package), etc., as well as general resin-packaged ICs (Integrated Circuits). In addition, specific examples include MCP (Multi-Chip Package) such as MCM (Multi-Chip Module); hybrid ICs, etc.

[0242] Resin-encapsulated ICs, for example, have a structure in which semiconductor elements are fixed on a lead frame, and after the terminals of the semiconductor elements are connected to the leads by wire bonding, bumps, etc., they are encapsulated using a packaging material by transfer molding or other methods. MCMs, for example, have a structure in which multiple semiconductor elements are connected to wiring formed on a support member by wire bonding, flip bonding, soldering, etc., and then encapsulated with a packaging material.

[0243] For example, a method for manufacturing a power semiconductor device includes placing a power semiconductor on a support member and encapsulating at least a portion of the power semiconductor using a packaging material of the embodiment described above. Examples of methods for encapsulating power semiconductor elements or devices include transfer molding, compression molding, and injection molding. Transfer molding, for example, can be performed under conditions of a mold temperature of 130°C to 180°C, a molding pressure of 6 MPa to 10 MPa, and a molding time of 60 seconds to 120 seconds. Post-curing heating conditions are, for example, at 150°C to 180°C for 2 hours to 16 hours.

[0244] <Examples of Implementation Modes>

[0245] Examples of embodiments are listed below. This invention is not limited to these embodiments.

[0246] (1) A packaging material for power semiconductor devices comprising a compound having a vinylphenyl group.

[0247] (2) According to the encapsulation material described in (1), wherein the compound having vinylphenyl comprises a compound represented by the formula (b3).

[0248] (3) According to the encapsulation material described in (1) or (2), the compound having vinylphenyl comprises at least one selected from the group consisting of polymers represented by formula (B3-3) and polymers represented by formula (B3-7).

[0249] (4) The packaging material according to any one of (1) to (3), wherein the compound having vinylphenyl comprises a compound having vinylphenylmethyl.

[0250] (5) The encapsulation material described in any one of (1) to (4) comprises a compound having vinyl bonds.

[0251] (6) The encapsulation material described in (5), wherein the compound having vinyl bonds comprises a compound having maleimide groups.

[0252] (7) The packaging material described in any one of (1) to (6), wherein the power semiconductor device is a power semiconductor module.

[0253] (8) An encapsulation material comprising a cured material obtained using an encapsulation material described in any one of (1) to (7).

[0254] (9) A power semiconductor device having a power semiconductor element and a package material according to (8) wherein the package material encapsulates at least a portion of the power semiconductor element.

[0255] (10) A power semiconductor module having a plurality of power semiconductor elements and power semiconductor devices selected from the group consisting of power semiconductor elements and power semiconductor devices, and a package material according to (8) wherein the package material encapsulates at least a portion of the plurality of power semiconductor elements.

[0256] The disclosure of this application relates to the subject matter described in Japanese Patent Application No. 2023-128621, filed on August 7, 2023, the entire disclosure of which is incorporated herein by reference.

[0257] [Example]

[0258] The embodiments of the present invention will be specifically described through examples. The embodiments of the present invention are not limited to the following examples.

[0259] <Synthesis of Vinylphenyl Compounds>

[0260] (Synthetic Example 1: Synthesis of Vinylphenyl Compound 1)

[0261] In a 500 mL reaction vessel equipped with a stirrer, thermometer, reflux pipe, and air pump, the phenolic resin, chloromethylstyrene, phase transfer catalyst, pure water, polymerization inhibitor, and solvent listed in Table 1 were added. The obtained composition was stirred at 40°C while air was blown in at a flow rate of 50 mL / min. Then, while maintaining the temperature at 70°C, the basic compound listed in Table 1 was added dropwise over 20 minutes, and the mixture was further stirred at 70°C for 4 hours. Air was continuously blown in during the reaction. The composition was cooled to room temperature (25°C), neutralized with 10% hydrochloric acid aqueous solution, and the organic phase was washed three times with pure water. Subsequently, the organic phase was precipitated in methanol to obtain the target vinylphenyl compound 1. Infrared absorption (IR) spectroscopy analysis confirmed that the structure of vinylphenyl compound 1 was such that the phenolic hydroxyl group contained in the phenolic resin was substantially entirely replaced by vinylbenzyl ether groups (vinylphenylmethyloxy groups). The weight-average molecular weight of vinylphenyl compound 1 is shown in Table 1.

[0262] (Synthetic Example 2: Synthesis of Vinylphenyl Compound 2)

[0263] Except for changing the raw materials to those listed in Table 1, vinylphenyl compound 2 was obtained using the same method as in Synthesis Example 1. Infrared absorption (IR) spectroscopy analysis confirmed that vinylphenyl compound 2 has a structure in which the phenolic hydroxyl groups in the phenolic resin are substantially entirely replaced by vinyl benzyl ether groups. The weight-average molecular weight of vinylphenyl compound 2 is shown in Table 1.

[0264] (Synthetic Example 3: Synthesis of Vinylphenyl Compound 3)

[0265] In a 500 mL reaction vessel equipped with a stirrer, thermometer, reflux tube, and nitrogen inlet, the aromatic hydrocarbons, chloromethylstyrene, phase transfer catalyst, polymerization inhibitor, and solvent listed in Table 1 were added. The resulting composition was stirred at 40°C while nitrogen was purged at a flow rate of 50 mL / min. Then, the basic compound listed in Table 1 was added dropwise over 20 minutes, and the mixture was further stirred at 60°C for 9 hours. Nitrogen was continuously purged during the reaction. The composition was cooled to room temperature (25°C), neutralized with 10% hydrochloric acid aqueous solution, and washed twice with pure water. Toluene was then removed by distillation under reduced pressure, and the resulting viscous liquid was washed with methanol and dried under vacuum to obtain vinylphenyl compound 3. 1 H-NMR ( 1 H-Nuclear Magnetic Resonance, 1 ¹H-NMR analysis confirmed that vinylphenyl compound 3 has a structure in which the two hydrogen atoms directly bonded to the carbon atom at position 1 of indene are substantially entirely replaced by vinylbenzyl groups (vinylphenylmethyl). Furthermore, gel permeation chromatography (GPC) analysis confirmed that vinylphenyl compound 3 is a mixture of compounds with two and three vinylbenzyl groups, with an average number of vinylbenzyl groups ranging from 1.6 to 2.6. The weight-average molecular weight of vinylphenyl compound 3 is shown in Table 1.

[0266] In the embodiments, the weight average molecular weight (Mw) and number average molecular weight (Mn) were measured under the following conditions.

[0267] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) were calculated using gel permeation chromatography with a calibration curve for standard polystyrene. The calibration curve was approximated using a cubic equation with standard polystyrene: TSK standard POLYSTYRENE (models: A-2500, A-5000, F-20, F-80) (Tosoh Corporation).

[0268] Equipment: High-speed GPC device HLC-8320GPC (Tosoh Corporation)

[0269] Detector: UV-8320 ultraviolet absorbance detector (Tosoh Corporation)

[0270] Tubing: Protective tubing; TSKgel guardcolumn Super (HZ)-M+ tubing; TSKgel SuperMultipore HZ-M (2 pieces); Reference tubing; TSKgel SuperH-RC (2 pieces) (all from Tosoh Corporation)

[0271] Tubing string dimensions: 4.6×20 mm (protective tubing string), 4.6×150 mm (tubing string), 6.0×150 mm (reference tubing string)

[0272] Eluent: Tetrahydrofuran

[0273] Sample concentration: 10 mg / 1 mL

[0274] Injection volume: 20 μL or 2 μL

[0275] Flow rate: 0.35 mL / min

[0276] Temperature measured: 40℃

[0277] The compounds listed in Table 1 are described below. In Table 1, the unit for each compound is "parts of mass". "-" indicates that the corresponding compound was not used. The hydroxyl equivalent of the phenolic resin was measured using the method described above.

[0278] (Phenolic resin)

[0279] HE100C-30: Aralkyl type phenolic resin, AirWater Corporation, weight average molecular weight (Mw) 2,350, number average molecular weight (Mn) 450, hydroxyl equivalent 170 g / eq~175 g / eq

[0280] MEHC-7851M: Biphenyl aralkyl type phenolic resin, manufactured by Meiwa Chemical Co., Ltd., with a weight average molecular weight (Mw) of 1,500, a number average molecular weight (Mn) of 900, and a hydroxyl equivalent of 201 g / eq to 220 g / eq.

[0281] (Aromatic hydrocarbons)

[0282] Indene: Molecular weight 116.2

[0283] [Chemistry 22]

[0284]

[0285] (chloromethylstyrene)

[0286] • CMS: A mixture of o-chloromethylstyrene and p-chloromethylstyrene, manufactured by Wujin Linchuan Chemical Company. The o-chloromethylstyrene content is 17% by mass, and the p-chloromethylstyrene content is 83% by mass.

[0287] • CMS-P: A mixture of m-chloromethylstyrene and p-chloromethylstyrene, manufactured by AGC Seimi Chemical Co., Ltd., containing 50% m-chloromethylstyrene by mass and 50% p-chloromethylstyrene by mass.

[0288] (Phase transfer catalyst)

[0289] Tetrabutylphosphonium bromide: Kanto Chemical Co., Inc.

[0290] Tetra-n-butylammonium bromide: Kanto Chemical Co., Ltd.

[0291] (Polymerization inhibitor)

[0292] ·Phenothiazine

[0293] (Organic solvent)

[0294] Toluene

[0295] 2-Propanol

[0296] (Alkaline compounds)

[0297] • Sodium hydroxide aqueous solution: Kanto Chemical Co., Ltd., concentration 48% by mass

[0298] [Table 1]

[0299]

[0300] <Preparation of Encapsulation Materials (Encapsulation Material Compositions)>

[0301] The vinylphenyl compounds obtained from Synthesis Examples 1 to 3 were placed in shallow metal pans and allowed to stand in a vacuum dryer for 5 hours at a pressure below 0.1 MPa and a temperature of 70°C to remove the solvent.

[0302] [Examples 1-5 and Comparative Example 1]

[0303] The solvent-removed vinylphenyl compound was premixed with the compounds listed in Table 2 (dry mixing), then kneaded using a biaxial kneader (kneading temperature 120°C), and the mixture was cooled and pulverized to produce a powdered composition for packaging materials.

[0304] The compounds listed in Table 2 are shown below. In Table 2, the unit for each compound is "mass fraction". "-" indicates that the corresponding compound is not present. The average particle size of the inorganic filler was measured according to the method described. The content (volume %) of the inorganic filler is the volume ratio of silica based on the volume of the encapsulation composition. "Vinylphenyl equivalent / maleimide equivalent" is the ratio of the vinylphenyl equivalent (weight average molecular weight / functionality) of the vinylphenyl compound to the maleimide equivalent (molecular weight / functionality calculated from the chemical formula) of the maleimide compound.

[0305] (Vinylphenyl compound)

[0306] • Vinylphenyl compound 1: The vinylphenyl compound (vinyl benzyl ether compound) obtained in Synthesis Example 1

[0307] • Vinylphenyl compound 2: The vinylphenyl compound (vinyl benzyl ether compound) obtained in Synthesis Example 2

[0308] (Vinyl compounds)

[0309] Maleimide compound 1: 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, KI Chemical Co., Ltd. "BMI-80"

[0310] • Maleimide compound 2: Polyphenylmethane maleimide, Daiwa Chemical Industries, Ltd. "BMI-2300"

[0311] (epoxy compound)

[0312] • Epoxy Resin 1: Triphenylmethane type epoxy resin, Nippon Kayaku Co., Ltd.'s "EPPN-501HY"

[0313] • Epoxy Resin 2: Biphenyl type epoxy resin, Mitsubishi Chemical Corporation "YX4000H"

[0314] (Phenolic resin)

[0315] • Phenolic resin: Biphenyl aralkyl resin, UBE Corporation "MEHC7851-SS"

[0316] (Other raw materials)

[0317] • Curing accelerator: phosphorus-based accelerator

[0318] Coupling agent 1: 3-mercaptopropyltrimethoxysilane, Shin-Etsu Chemical Industry Co., Ltd. "KBM-803"

[0319] Coupling agent 2: N-phenyl-3-aminopropyltrimethoxysilane, Shin-Etsu Chemical Industry Co., Ltd. "KBM-573"

[0320] • Release agent: Montan wax, Clariant Ltd. (Japan) "HW-E"

[0321] • Colorant: Carbon black, Mitsubishi Chemical Corporation "MA100RMJ"

[0322] • Inorganic filler material: Silica (average particle size 26.9 μm), Zhejiang Huafeng Electronic Substrate Co., Ltd. "SS-205"

[0323] <Preparation of cured products>

[0324] Cured products were prepared using an encapsulation material composition, and resistance to tracking, molding shrinkage, and water absorption were measured. The measurement results are shown in Table 2.

[0325] (Measurement of resistance to tracking)

[0326] Using a transfer molding machine (Techno Marushichi Co., Ltd.), a disc-shaped molded part with a diameter of 5 mm and a thickness of 3 mm was obtained under the conditions of mold temperature 175°C, molding time 120 seconds, and molding pressure 6.9 MPa. The resulting molded part was completely cured at 175°C for 6 hours. Using the obtained cured part, a tracking resistance test was conducted using a HAT-112-3 tracking resistance tester (Yamayo Testing Instruments Co., Ltd.) according to the method of JIS C2134:2021 (IEC60112). In the test, the number of measurements was n=5, and more than 50 drops of 0.1% ammonium chloride aqueous solution were added to each cured part. The maximum voltage that did not break down all cured parts was measured. The higher this maximum voltage, the better the tracking resistance.

[0327] (Measurement of molding shrinkage)

[0328] Using a mold and a transfer molding machine (Techno Marushichi, Inc.), a disc-shaped object (approximately 80 mm in diameter × approximately 4 mm in thickness) was formed at a mold temperature of 175°C, a molding time of 120 seconds, and a molding pressure of 6.9 MPa. The object was then cooled to 25°C. After cooling to 25°C, the object was placed in an oven at 175°C for 6 hours to cure it, and then the cured object was cooled to 25°C. After cooling, the diameter of the cured object's surface and back sides were measured, and the average of the two measurements was taken as Rm (mm). The mold inner diameter corresponding to the surface of the cured object and the mold inner diameter corresponding to the back side of the cured object were measured, and the average of the two measurements was taken as Rd (mm). The molding shrinkage rate (%) was calculated from Rm (mm) and Rd (mm) using the following formula.

[0329] Molding shrinkage rate (%) = (Rd - Rm) / Rd × 100

[0330] (Measurement of water absorption rate)

[0331] A disc-shaped molded object (50 mm in diameter × 3 mm in thickness) was obtained using a transfer molding machine (Techno Marushichi Co., Ltd.) under conditions of mold temperature 175°C, molding time 120 seconds, and molding pressure 6.9 MPa. The resulting molded object was then cured by heating at 175°C for 6 hours to obtain a cured product. Using a pressure cooker testing apparatus (Hirayama Manufacturing Co., Ltd.), the cured product was pressure-cooked for 20 hours under conditions of pressure 2 atm (0.2 MPa), temperature 121°C, and relative humidity 100%RH. The mass of the cured product before and after pressure cooker treatment was measured, and the water absorption rate (mass%) was calculated using the following formula.

[0332] Water absorption rate (mass%) = ((mass after treatment - mass before treatment) / mass before treatment) × 100

[0333] [Table 2]

[0334]

Claims

1. A packaging material for a power semiconductor device, said packaging material comprising a compound having a vinylphenyl group.

2. The packaging material according to claim 1, wherein, The compound having a vinylphenyl group comprises a compound represented by the following formula (b3); [Chemistry 1] (In the formula, B) hb Each of the following independently represents a hydrogen atom, a group represented by the following formula (Ba), or a group represented by the following formula (Bz), and at least one B hb It is a basis represented by the following formula (Bz); [Chemistry 2] (In the formula, A represents an alkyl group, and * represents the bond position.) [Chemistry 3] (In the formula, * indicates the location of the bond).

3. The encapsulation material according to claim 1 or 2, wherein the vinylphenyl compound comprises at least one selected from the group consisting of polymers represented by formula (B3-3) and polymers represented by formula (B3-7); [Chemistry 4] (In the formula, B) b Each group independently represents a base represented by the following formula (Bz); n represents a number from 3 to 5; the benzene ring can independently have substituents at substituted positions. [Chemistry 5] (In the formula, B) b Each group independently represents a base represented by the following formula (Bz); n represents a number from 3 to 5; the benzene ring can independently have substituents at substituted positions. [Chemistry 6] (In the formula, * indicates the location of the bond).

4. The packaging material according to any one of claims 1 to 3, wherein the compound having vinylphenyl comprises a compound having vinylphenylmethyl.

5. The encapsulation material according to any one of claims 1 to 4, comprising a compound having vinyl bonds.

6. The encapsulation material according to claim 5, wherein the compound having vinyl bonds comprises a compound having maleimide groups.

7. The packaging material according to any one of claims 1 to 6, wherein the power semiconductor device is a power semiconductor module.

8. An encapsulation material comprising a cured product obtained using an encapsulation material according to any one of claims 1 to 7.

9. A power semiconductor device having a power semiconductor element and a package material according to claim 8, the package material encapsulating at least a portion of the power semiconductor element.

10. A power semiconductor module having a plurality selected from the group consisting of power semiconductor elements and power semiconductor devices, and a package material according to claim 8, the package material encapsulating at least a portion of the plurality.

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