Resin composition for transfer molding and encapsulation, and semiconductor device.

Abstract

To provide a resin composition for sealing that is capable of forming a cured product with superior adhesion to silicon nitride while maintaining low dielectric loss tangents at 20 GHz, and a semiconductor device equipped with an element sealed therewith.SOLUTION: A sealing resin composition contains an epoxy resin, and a curing agent containing an active ester compound and a nitrogen-containing phenolic compound.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to Transfer molding a sealing resin composition and a semiconductor device.

Background Art

[0002] In recent years, computers, information and communication equipment, and the like have increasingly higher performance and more advanced functions, and process a large amount of data at high speed, so the signals handled tend to have higher frequencies. When handling signals in a high-frequency region (for example, 20 GHz or higher), low transmission loss is desired. From the viewpoint of suppressing this transmission loss, materials with a low dielectric loss tangent are also desired for cured products of sealing resin compositions that seal elements of semiconductor devices. Here, Patent Document 1 discloses a thermosetting resin composition containing an active ester resin as a curing agent for epoxy resins, which is described to be capable of keeping the dielectric loss tangent of the cured product low.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] In addition, in recent years, silicon nitride has tended to be used as a next-generation substrate material for semiconductor materials. Therefore, high adhesion to silicon nitride is also desired for cured products of sealing resin compositions that seal elements of semiconductor devices. In view of the above circumstances, an object of the present disclosure is to provide a sealing resin composition capable of forming a cured product excellent in adhesive force to silicon nitride while maintaining a low dielectric loss tangent at 20 GHz, and a semiconductor device including an element sealed with the same.

Means for Solving the Problem

[0005] The following embodiments are included as means for solving the above problems.

[0006] [1] Epoxy resin and A curing agent containing an active ester compound and a nitrogen-containing phenol compound, A encapsulating resin composition containing the following:

[0007] [2] The sealing resin composition according to [1], wherein the hydroxyl group equivalent of the nitrogen-containing phenol compound is 100 g / eq or more.

[0008] [3] The encapsulating resin composition according to [1] or [2], wherein the nitrogen-containing phenol compound comprises a nitrogen-containing heterocyclic compound.

[0009] [4] The encapsulating resin composition according to [3], wherein the nitrogen-containing heterocyclic compound comprises a heterocyclic compound having two or more nitrogen atoms as atoms constituting the heterocyclic skeleton.

[0010] [5] The sealing resin composition according to any one of the above [1] to [4], wherein the content of the nitrogen-containing phenol compound is 15% by mass or less with respect to the total amount of the curing agent.

[0011] [6] The sealing resin composition according to any one of [1] to [5], further comprising an inorganic filler.

[0012] [7] The sealing resin composition according to [6], wherein the content of the inorganic filler is 65% by volume or more in the sealing resin composition.

[0013] [8] A semiconductor device comprising a semiconductor element and a cured product of the sealing resin composition described in any one of [1] to [7] above, which is obtained by sealing the semiconductor element. [Effects of the Invention]

[0014] This disclosure provides a encapsulating resin composition capable of forming a cured product with excellent adhesion to silicon nitride while maintaining a low dielectric loss tangent at 20 GHz, and a semiconductor device comprising an element encapsulated therewith. [Modes for carrying out the invention]

[0015] In this disclosure, the term "process" includes not only processes that are independent of other processes, but also processes that cannot be clearly distinguished from other processes, provided that the purpose of such process is achieved. In this disclosure, the numerical range indicated using "~" includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages within this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in numerical ranges described within this disclosure, the upper or lower limit of that range may be replaced with the values ​​shown in the examples. In this disclosure, each component may contain multiple types of the corresponding substance. If multiple types of the substance corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple types of substances present in the composition, unless otherwise specified. In this disclosure, each component may contain multiple types of particles. If multiple types of particles corresponding to each component are present in the composition, the particle size of each component refers to the value for a mixture of such multiple types of particles present in the composition, unless otherwise specified.

[0016] -Sealing resin composition- The encapsulating resin composition of this disclosure contains an epoxy resin and a curing agent comprising an active ester compound and a nitrogen-containing phenol compound. The encapsulating resin composition may also contain other additives.

[0017] The encapsulating resin composition of the present disclosure can form a cured product excellent in adhesive strength to silicon nitride while maintaining a low dielectric loss tangent at 20 GHz. Although the reason therefor is not necessarily clear, it is considered as follows.

[0018] The encapsulating resin composition of the present disclosure contains an active ester compound as a curing agent. Phenol curing agents and the like generally used as curing agents for epoxy resins readily generate secondary hydroxyl groups in the reaction with epoxy resins. In contrast, when an active ester compound is used as a curing agent, an ester group is generated instead of a secondary hydroxyl group in the curing reaction with an epoxy resin. Ester groups have lower polarity than secondary hydroxyl groups and are less likely to polarize. Therefore, it is considered that the dielectric loss tangent of the cured product can be suppressed lower when an active ester compound is used, compared to when a curing agent such as a phenol resin that generates secondary hydroxyl groups is used. On the other hand, it has been revealed that when an active ester compound is used as a curing agent, the adhesion of the obtained cured product to silicon nitride is reduced. As described above, it has been found that when an active ester compound is used as a curing agent, although the dielectric loss tangent of the obtained cured product can be suppressed to a low level, there is a trade-off relationship in that the adhesion to silicon nitride is reduced.

[0019] In contrast, in the encapsulating resin composition of the present disclosure, as a curing agent, the active ester compound additionally contains a nitrogen-containing phenol compound. It is considered that the adhesion to a silicon nitride substrate is improved by the nitrogen atom site in the nitrogen-containing phenol compound. In addition, although the degree of reactivity of the phenol site in the nitrogen-containing phenol compound with the epoxy resin is not clear, since the dielectric loss tangent in the cured product is maintained at a low level, it is considered that the curing reaction between the active ester compound and the epoxy resin is not inhibited.

[0020] [Epoxy resin] The encapsulating resin composition contains an epoxy resin. The type of epoxy resin contained in the encapsulating resin composition of the present disclosure is not particularly limited. Specifically, the epoxy resins include: novolac-type epoxy resins (phenol novolac-type epoxy resins, orthocresol novolac-type epoxy resins, etc.) obtained by condensing or co-condensing a novolac resin (phenol novolac-type epoxy resins, orthocresol novolac-type epoxy resins, etc.) obtained by condensing or co-condensing a novolac resin (phenol novolac-type epoxy resins, orthocresol novolac-type epoxy resins, etc.) obtained by condensing or co-condensing the above phenolic compound with an aromatic aldehyde compound (benzaldehyde, salicylaldehyde, etc.) under an acidic catalyst; triphenylmethane-type epoxy resins obtained by condensing or co-condensing a triphenylmethane-type phenolic resin (phenol novolac-type epoxy resins, orthocresol novolac-type epoxy resins, etc.) obtained by condensing or co-condensing the above phenolic compound with an aromatic aldehyde compound (benzaldehyde, salicylaldehyde, etc.) under an acidic catalyst; and novolac resins obtained by co-condensing the above phenolic compound and naphthol compound with an aldehyde compound under an acidic catalyst. Copolymer epoxy resins that are cytopolymerized; diphenylmethane-type epoxy resins that are diglycidyl ethers of bisphenol A, bisphenol F, etc.; biphenyl-type epoxy resins that are diglycidyl ethers of aralkyl-substituted, alkyl-substituted, or unsubstituted biphenols; stilbene-type epoxy resins that are diglycidyl ethers of stilbene-based phenol compounds; sulfur atom-containing epoxy resins that are diglycidyl ethers of bisphenol S, etc.; epoxy resins that are glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; glycidyl ester-type epoxy resins that are glycidyl esters of polycarboxylic acid compounds such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; glycidylamine-type epoxy resins in which the active hydrogen bonded to the nitrogen atom of aniline, diaminodiphenylmethane, isocyanuric acid, etc. is substituted with a glycidyl group; dicyclopentadiene-type epoxy resins that are epoxidized from a co-condensation resin of dicyclopentadiene and a phenol compound;Alicyclic epoxy resins such as vinylcyclohexene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane, which have epoxidized olefin bonds within the molecule; paraxylylene-modified epoxy resins, which are glycidyl ethers of paraxylylene-modified phenol resins; metaxylylene-modified epoxy resins, which are glycidyl ethers of metaxylylene-modified phenol resins; terpene-modified epoxy resins, which are glycidyl ethers of terpene-modified phenol resins; dicyclopentadiene-modified epoxy resins, which are glycidyl ethers of dicyclopentadiene-modified phenol resins; cy Examples of epoxy resins include: cyclopentadiene-modified epoxy resins, which are glycidyl ethers of lopentadiene-modified phenol resins; polycyclic aromatic ring-modified epoxy resins, which are glycidyl ethers of polycyclic aromatic ring-modified phenol resins; naphthalene-type epoxy resins, which are glycidyl ethers of naphthalene ring-containing phenol resins; halogenated phenol novolac-type epoxy resins; hydroquinone-type epoxy resins; trimethylolpropane-type epoxy resins; linear aliphatic epoxy resins obtained by oxidizing olefin bonds with peracids such as peracetic acid; aralkyl-type epoxy resins, which are epoxidized aralkyl-type phenol resins such as phenol aralkyl resins, naphthol aralkyl resins, and biphenyl aralkyl resins; aralkyl-type phenol resins and biphenols. Furthermore, epoxides of acrylic resins can also be cited as epoxy resins. Among the above, epoxy resins include aralkyl epoxy resin and biphenyl epoxy resin. Xyl resins are preferred. Epoxy resins may be used individually or in combination of two or more types.

[0021] The epoxy equivalent (molecular weight / number of epoxy groups) of the epoxy resin is not particularly limited. From the viewpoint of balancing various properties such as moldability, reflow resistance, and electrical reliability, it is preferably 100 g / eq to 1000 g / eq, and more preferably 150 g / eq to 500 g / eq.

[0022] The epoxy equivalent of the epoxy resin shall be the value measured according to the method conforming to JIS K 7236:2009.

[0023] When the epoxy resin is solid, its softening point or melting point is not particularly limited. From the viewpoint of moldability and reflow resistance, it is preferably 40°C to 180°C, and from the viewpoint of ease of handling during the preparation of the encapsulating resin composition, it is more preferably 50°C to 130°C.

[0024] The melting point or softening point of the epoxy resin shall be the value measured by differential scanning calorimetry (DSC) or by a method in accordance with JIS K 7234:1986 (ring-sphere method).

[0025] The epoxy resin content in the sealing resin composition is preferably 0.5% to 50% by mass, and more preferably 2% to 30% by mass, from the viewpoint of strength, fluidity, heat resistance, moldability, etc.

[0026] [Hardening agent] The sealing resin composition contains a curing agent. The curing agent includes an active ester compound and a nitrogen-containing phenol compound. The sealing resin composition may also contain curing agents other than the active ester compound and the nitrogen-containing phenol compound.

[0027] (Activated ester compounds) In this disclosure, an active ester compound refers to a compound that has one or more ester groups that react with epoxy groups in one molecule and has the effect of curing epoxy resins.

[0028] As described above, the encapsulating resin composition of this disclosure can suppress the dielectric loss tangent of the cured product by using an active ester compound as a curing agent. Furthermore, since polar groups in the cured product increase its water absorption, using an active ester compound as a curing agent tends to suppress the concentration of polar groups in the cured product and thus suppress its water absorption. It is also believed that by suppressing the water absorption of the cured product, that is, by suppressing the content of H2O, a polar molecule, the dielectric loss tangent of the cured product can be further reduced. The water absorption rate of the cured product is preferably 0% to 0.35%, more preferably 0% to 0.30%, and even more preferably 0% to 0.25%. Here, the water absorption rate of the cured product is the mass increase rate determined by a pressure cooker test (121°C, 2.1 atm, 24 hours).

[0029] The type of active ester compound is not particularly limited, as long as it is a compound that has one or more ester groups in its molecule that react with epoxy groups.

[0030] Examples of active ester compounds include phenol ester compounds, thiophenol ester compounds, N-hydroxyamine ester compounds, and esterified heterocyclic hydroxy compounds.

[0031] Examples of active ester compounds include a small amount of aliphatic carboxylic acid and aromatic carboxylic acid. Examples include ester compounds obtained from at least one aliphatic hydroxy compound and at least one aromatic hydroxy compound. Ester compounds in which an aliphatic compound is the polycondensation component tend to have excellent compatibility with epoxy resins due to the presence of an aliphatic chain. Ester compounds in which an aromatic compound is the polycondensation component tend to have excellent heat resistance due to the presence of an aromatic ring.

[0032] Specific examples of active ester compounds include aromatic esters obtained by the condensation reaction of aromatic carboxylic acids and phenolic hydroxyl groups. In particular, aromatic esters obtained by the condensation reaction of aromatic carboxylic acids and phenolic hydroxyl groups are preferred, using a mixture of an aromatic carboxylic acid component in which 2 to 4 hydrogen atoms of the aromatic ring are substituted with carboxyl groups (such as benzene, naphthalene, biphenyl, diphenylpropane, diphenylmethane, diphenyl ether, and diphenylsulfonic acid), a monovalent phenol in which 1 hydrogen atom of the aforementioned aromatic ring is substituted with a hydroxyl group, and a polyvalent phenol in which 2 to 4 hydrogen atoms of the aforementioned aromatic ring are substituted with hydroxyl groups as raw materials. Specifically, aromatic esters having structural units derived from the above aromatic carboxylic acid component, structural units derived from the above monovalent phenol, and structural units derived from the above polyvalent phenol are preferred.

[0033] Specific examples of active ester compounds include active ester resins having a structure obtained by reacting a phenol resin having a molecular structure in which a phenol compound is bonded via an aliphatic cyclic hydrocarbon group, as described in Japanese Patent Publication No. 2012-246367, with an aromatic dicarboxylic acid or its halide and an aromatic monohydroxy compound. The compound represented by the following structural formula (1) is preferred as the active ester resin.

[0034] [ka]

[0035] In structural formula (1), R 1 X is an alkyl group having 1 to 4 carbon atoms, X is a benzene ring, a naphthalene ring, a benzene or naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms, or a biphenyl group, Y is a benzene ring, a naphthalene ring, or a benzene or naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms, k is 0 or 1, and n represents the average number of repetitions, ranging from 0.25 to 1.5.

[0036] Specific examples of compounds represented by structural formula (1) include the following example compounds (1-1) to (1-10). In the structural formula, t-Bu is a tert-butyl group.

[0037] [ka]

[0038] [ka]

[0039] Other specific examples of active ester compounds include the compound represented by the following structural formula (2) and the compound represented by the following structural formula (3), as described in Japanese Patent Publication No. 2014-114352.

[0040] [ka]

[0041] In structural formula (2), R 1 and R 2 Each of these independently consists of a hydrogen atom and an alkyl group having 1 to 4 carbon atoms. Z is a group or an alkoxy group having 1 to 4 carbon atoms, and Z is an ester-forming structural site (z1) selected from the group consisting of a benzoyl group, a naphthoyl group, a benzoyl group or naphthoyl group substituted with an alkyl group having 1 to 4 carbon atoms, and an acyl group having 2 to 6 carbon atoms, or a hydrogen atom (z2), and at least one of Z is an ester-forming structural site (z1).

[0042] [ka]

[0043] In structural formula (3), R1 and R 2 Each of the elements is independently a hydrogen atom, a C1-C4 alkyl group, or a C1-C4 alkoxy group, and Z is an ester-forming structural site (z1) selected from the group consisting of a benzoyl group, a naphthoyl group, a benzoyl group or naphthoyl group substituted with a C1-C4 alkyl group, and a C2-C6 acyl group, or a hydrogen atom (z2), and at least one of the elements of Z is an ester-forming structural site (z1).

[0044] Specific examples of compounds represented by structural formula (2) include the following example compounds (2-1) to (2-6).

[0045] [ka]

[0046] Specific examples of compounds represented by structural formula (3) include the following example compounds (3-1) to (3-6).

[0047] [ka]

[0048] Commercially available active ester compounds may be used. Examples of commercially available active ester compounds include "EXB9451," "EXB9460," "EXB9460S," and "HPC-8000-65T" (manufactured by DIC Corporation) as active ester compounds containing a dicyclopentadiene-type diphenol structure; "EXB9416-70BK," "EXB-8," and "EXB-9425" (manufactured by DIC Corporation) as active ester compounds containing an aromatic structure; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing an acetylated phenol novolac; and "YLH1026" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing a benzoylated phenol novolac.

[0049] The active ester compound may be used individually or in combination of two or more compounds.

[0050] The ester equivalent of the active ester compound is not particularly limited. From the viewpoint of balancing various properties such as moldability, reflow resistance, and electrical reliability, 150 g / eq to 400 g / eq is preferred, 170 g / eq to 300 g / eq is more preferred, and 200 g / eq to 250 g / eq is even more preferred.

[0051] The ester equivalent of the active ester compound shall be the value measured by the method in accordance with JIS K 0070:1992.

[0052] From the viewpoint of keeping the dielectric loss tangent of the cured product low, the equivalent ratio (ester group / epoxy group) of the epoxy resin to the active ester compound is preferably 0.75 or higher, more preferably 0.80 or higher, and even more preferably 0.85 or higher. From the viewpoint of minimizing the amount of unreacted active ester compound, the equivalent ratio (ester group / epoxy group) of epoxy resin to active ester compound is preferably 1.10 or less, more preferably 1.05 or less, and even more preferably 1.03 or less.

[0053] From the viewpoint of keeping the dielectric loss tangent of the curing agent low, the lower limit of the content of the active ester compound is preferably 85% by mass or more, more preferably 88% by mass or more, and even more preferably 90% by mass or more. The upper limit of the content of the active ester compound relative to the total amount of curing agent is preferably 98% by mass or less, more preferably 97% by mass or less, and even more preferably 96% by mass or less.

[0054] (Nitrogen-containing phenolic compounds) The curing agent of this disclosure comprises a nitrogen-containing phenol compound. A nitrogen-containing phenol compound is a compound that contains both a group with a nitrogen atom and an aromatic group with a hydroxyl group within a single molecule. Nitrogen-containing phenol compounds may be used individually or in combination of two or more types.

[0055] The group having a nitrogen atom is not particularly limited and may be a nitrogen-containing functional group, or a group obtained by removing one arbitrary hydrogen atom from a nitrogen-containing heterocyclic compound. In one molecule of the nitrogen-containing phenol compound, one type of nitrogen-containing functional group or a group obtained by removing one hydrogen atom from a nitrogen-containing heterocyclic compound may be used alone, or two or more types of groups may be used in combination.

[0056] Examples of nitrogen-containing functional groups include amino groups, amide groups, and cyano groups. Groups obtained by removing one arbitrary hydrogen atom from a nitrogen-containing heterocyclic compound include groups obtained by removing one arbitrary hydrogen atom from nitrogen-containing alicyclic compounds, nitrogen-containing aromatic compounds, and the like. Examples of nitrogen-containing alicyclic compounds include pyrrolidine, piperidine, morpholine, diazabicycloundecene, and diazabicyclononene. Examples of nitrogen-containing aromatic compounds include pyridine, melamine, diazole compounds (imidazole, pyrazole, etc.), oxadiazole compounds (1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-oxadiazole, etc.), triazine compounds (1,2,3-triazine, 1,2,4-triazine, 1,3,5-triazine, etc.), triazole compounds (1,2,3-triazole, 1,2,4-triazole, etc.), and benzotriazole compounds (1,2,3-benzotriazole, 1,2,4-benzotriazole, etc.). Among the above, the nitrogen-containing aromatic compound is preferably at least one selected from the group consisting of melamine, triazole compounds, and benzotriazole compounds, from the viewpoint of further improving the adhesion of the cured product to the silicon nitride substrate.

[0057] The aromatic group in the aromatic group having a hydroxyl group is not particularly limited, and any group obtained by removing one hydrogen atom from any known aromatic compound may be used as appropriate. Aromatic groups containing a hydroxyl group include groups obtained by removing one arbitrary hydrogen atom from aromatic compounds such as benzene, naphthalene, and triazine compounds (1,2,3-triazine, 1,2,4-triazine, 1,3,5-triazine, etc.). Among the above, the aromatic group having a hydroxyl group is preferably a benzene ring from which one arbitrary hydrogen atom has been removed, from the viewpoint of further improving the adhesion of the cured product to the silicon nitride substrate. In other words, the aromatic group having a hydroxyl group is preferably a phenol group.

[0058] Among the above, it is preferable that the nitrogen-containing phenol compound contains a nitrogen-containing heterocyclic compound. The nitrogen-containing heterocyclic compound may be included as a group having a nitrogen atom, or as an aromatic group in an aromatic group having a hydroxyl group. It is more preferable that the nitrogen-containing heterocyclic compound contains a nitrogen-containing aromatic compound. When a nitrogen-containing phenol compound contains a nitrogen-containing heterocyclic compound, the adhesion of the cured resin composition containing it to the silicon nitride substrate tends to be improved.

[0059] The number of nitrogen atoms constituting the heterocyclic skeleton in a nitrogen-containing heterocyclic compound is not particularly limited. For example, a nitrogen-containing heterocyclic compound preferably contains a heterocyclic compound having two or more nitrogen atoms as atoms constituting the heterocyclic skeleton, and more preferably contains a heterocyclic compound having three or more nitrogen atoms. When a nitrogen-containing heterocyclic compound includes a heterocyclic compound having two or more nitrogen atoms, the multiple nitrogen atoms in the nitrogen-containing phenol compound tend to interact cooperatively with the silicon nitride substrate when the encapsulating resin composition containing it is cured. As a result, the adhesion of the cured product to the silicon nitride substrate tends to improve.

[0060] The nitrogen-containing phenol compound may have substituents. The position of substituents in nitrogen-containing phenol compounds is not particularly limited, as long as hydrogen atoms other than those of the hydroxyl group in the aromatic group having a hydroxyl group are substituted. Substituents in nitrogen-containing phenol compounds are not particularly limited and include C1-C20 alkyl groups, C2-C20 alkenyl groups, C7-C20 aralkyl groups, C1-C20 alkoxy groups, C6-C14 aryl groups, C5-C14 heteroaryl groups, and halogen atoms (fluorine, iodine, chlorine, etc.). The alkyl groups, aralkyl groups, and alkoxy groups in the substituents may be linear, branched, or cyclic. When two or more substituents are present in a nitrogen-containing phenol compound, the substituents bonded to adjacent positions may bond to each other and link with an aromatic ring in an aromatic group having a hydroxyl group, a heterocyclic compound having a nitrogen atom, etc., to form a ring.

[0061] The position at which the group having a nitrogen atom and the aromatic group having a hydroxyl group are linked is not particularly limited and may be on a carbon atom or on a nitrogen atom. For example, if the group having a nitrogen atom is a group obtained by removing one arbitrary hydrogen atom from a benzotriazole compound, the nitrogen-containing phenol compound may have a structure in which the nitrogen atom at position 2 in the benzotriazole compound is linked to the carbon atom at position 2 on the aromatic group of the aromatic group having a hydroxyl group.

[0062] A group containing a nitrogen atom and an aromatic group containing a hydroxyl group may be linked via a linking group, or they may be linked directly without a linking group. When a group containing a nitrogen atom and an aromatic group containing a hydroxyl group are linked via a linking group, the type of linking group is not particularly limited, and examples include alkylene groups having 1 to 5 carbon atoms.

[0063] The nitrogen-containing phenol compound may be a synthetic product or a commercially available product. Commercially available nitrogen-containing phenolic compounds include HPM-J3 from Hitachi Chemical Co., Ltd.; SEESORB709, SEESORB707, SEESORB706, SEESORB704, etc. from Cipro Chemical Co., Ltd.; Tinuvin928, etc. from BASF Japan Ltd.; SIAsorb UV1164 from Sun Chemical Co., Ltd.; and EP-3980S, LA-31, etc. from ADEKA Corporation.

[0064] The hydroxyl group equivalent of the nitrogen-containing phenol compound is preferably 100 g / eq or more, more preferably 110 g / eq to 600 g / eq, and even more preferably 115 g / eq to 550 g / eq.

[0065] When the hydroxyl group equivalent of a nitrogen-containing phenol compound is 100 g / eq or higher, there is a tendency for there to be no excessive hydroxyl groups in a single molecule of the nitrogen-containing phenol compound. Therefore, when the encapsulating resin composition is cured, the crosslinking density in the cured product does not become excessively high, and the increase in dielectric loss tangent tends to be further suppressed.

[0066] The nitrogen-containing phenol compound content is preferably 15% by mass or less, more preferably 1% to 12% by mass, and even more preferably 3% to 10% by mass, relative to the total amount of the curing agent. When the nitrogen-containing phenol compound content is 15% by mass or less relative to the total amount of the curing agent, the increase in the dielectric loss tangent in the cured product tends to be further suppressed when the sealing resin composition is cured.

[0067] The nitrogen-containing phenol compound content is preferably 15% by mass or less, more preferably 1% to 12% by mass, and even more preferably 3% to 10% by mass, relative to the total amount of the active ester compound. When the nitrogen-containing phenol compound content is 15% by mass or less relative to the total amount of the active ester compound, the increase in the dielectric loss tangent of the cured product tends to be suppressed when the sealing resin composition is cured. On the other hand, when the nitrogen-containing phenol compound content is 1% by mass or more relative to the total amount of the active ester compound, a cured product with excellent adhesion to silicon nitride is obtained while maintaining the dielectric loss tangent.

[0068] (Other hardening agents) The curing agent may include other curing agents besides active ester compounds and nitrogen-containing phenol compounds. When other curing agents are included, the type of other curing agent is not particularly limited and can be selected according to the desired properties of the encapsulating resin composition. Examples of other curing agents include phenol curing agents that do not contain nitrogen atoms, acid anhydride curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, and blocked isocyanate curing agents.

[0069] Specifically, phenol curing agents that do not contain nitrogen atoms include polyhydric phenol compounds such as resorcinol, catechol, bisphenol A, bisphenol F, and substituted or unsubstituted biphenols; at least one phenolic compound selected from the group consisting of phenol compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene; and formaldehyde, acetaldehyde, and pu Examples include novolac-type phenolic resins obtained by condensing or co-condensing aldehyde compounds such as ropionaldehyde under an acidic catalyst; aralkyl-type phenolic resins such as phenol aralkyl resins and naphthol aralkyl resins synthesized from the above phenolic compound with dimethoxyp-xylene, bis(methoxymethyl)biphenyl, etc.; para-xylylene-modified phenolic resins and meta-xylylene-modified phenolic resins; terpene-modified phenolic resins; dicyclopentadiene-type phenolic resins and dicyclopentadiene-type naphthol resins synthesized by copolymerization of the above phenolic compound with dicyclopentadiene; cyclopentadiene-modified phenolic resins; polycyclic aromatic ring-modified phenolic resins; biphenyl-type phenolic resins; triphenylmethane-type phenolic resins obtained by condensing or co-condensing the above phenolic compound with aromatic aldehyde compounds such as benzaldehyde and salicylaldehyde under an acidic catalyst; and phenolic resins obtained by copolymerizing two or more of these. These phenol curing agents may be used individually or in combination of two or more.

[0070] The functional group equivalents of other curing agents (hydroxyl group equivalents in the case of phenol curing agents) are not particularly limited. From the viewpoint of balancing various properties such as moldability, reflow resistance, and electrical reliability, it is preferable that the amount is 70 g / eq to 1000 g / eq, and more preferably 80 g / eq to 500 g / eq.

[0071] The functional group equivalents of other curing agents (hydroxyl group equivalents in the case of phenol curing agents) are as follows: JIS K The value shall be measured according to the method specified in 0070:1992.

[0072] (Properties of the hardening agent) The softening point or melting point of the curing agent is not particularly limited. From the viewpoint of moldability and reflow resistance, it is preferably 40°C to 180°C, and from the viewpoint of handling during the manufacture of the sealing resin composition, it is more preferably 50°C to 130°C.

[0073] The melting point or softening point of the hardening agent shall be the value measured by the single-cylinder rotational viscometer method described in JIS K 7234:1986 and JIS K 7233:1986.

[0074] The equivalent ratio of epoxy resin to all curing agents (active ester compounds, nitrogen-containing phenol compounds, and other curing agents), i.e., the ratio of the number of functional groups in the curing agent to the number of functional groups in the epoxy resin (number of functional groups in curing agent / number of functional groups in epoxy resin), is not particularly limited. From the viewpoint of minimizing unreacted components, it is preferable to set it in the range of 0.5 to 2.0, and more preferably in the range of 0.6 to 1.3. From the viewpoint of moldability and reflow resistance, it is even more preferable to set it in the range of 0.8 to 1.2.

[0075] [Inorganic filler] The encapsulating resin composition of this disclosure may contain an inorganic filler. The type of inorganic filler is not particularly limited. Specifically, examples include inorganic materials such as fused silica, crystalline silica, glass, alumina, talc, clay, and mica. An inorganic filler having a flame-retardant effect may also be used. Examples of inorganic fillers having a flame-retardant effect include aluminum hydroxide, magnesium hydroxide, composite metal hydroxides such as magnesium-zinc composite hydroxides, and zinc borate.

[0076] Among inorganic fillers, silica such as fused silica is preferred from the viewpoint of reducing the coefficient of thermal expansion, and alumina is preferred from the viewpoint of high thermal conductivity. One type of inorganic filler may be used alone, or two or more types may be used in combination. Examples of inorganic filler forms include powder, beads formed from spherical powder, and fibers.

[0077] When the inorganic filler is in particulate form, its average particle size is not particularly limited. For example, it is preferable that the average particle size is 0.2 μm to 100 μm, and preferably 0.5 μm to 50 μm. More preferable. When the average particle size is 0.2 μm or larger, the increase in viscosity of the sealing resin composition tends to be more suppressed. When the average particle size is 100 μm or smaller, the packing performance tends to be more improved. The average particle size of the inorganic filler is determined as the volume-average particle size (D50) using a laser scattering diffraction particle size distribution analyzer.

[0078] The content of inorganic fillers in the sealing resin composition is not particularly limited. The inorganic filler content is preferably 60% to 90% by volume, more preferably 65% ​​to 85% by volume, and even more preferably 70% to 80% by volume in the sealing resin composition. When the inorganic filler content is 60% by volume or more in the sealing resin composition, the properties of the cured product, such as the coefficient of thermal expansion, thermal conductivity, and elastic modulus, tend to improve further. When the inorganic filler content is 90% by volume or less in the encapsulating resin composition, the increase in viscosity of the encapsulating resin composition is suppressed, and the fluidity tends to improve, resulting in better moldability.

[0079] [Various additives] In addition to the components described above, the sealing resin composition may also contain various additives such as coupling agents, ion exchangers, mold release agents, flame retardants, colorants, and stress relievers, as exemplified below. The sealing resin composition may also contain, as necessary, various additives well known in the art, in addition to those exemplified below.

[0080] (Coupling agent) The encapsulating resin composition may contain a coupling agent. From the viewpoint of improving the adhesion between the resin component and the inorganic filler, it is preferable that the encapsulating resin composition contains a coupling agent. Examples of known coupling agents include silane compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, and vinylsilane, as well as titanium compounds, aluminum chelate compounds, and aluminum / zirconium compounds.

[0081] When the encapsulating resin composition contains a coupling agent, the amount of the coupling agent is preferably 0.05 parts by mass to 5 parts by mass, more preferably 0.1 parts by mass to 2.5 parts by mass, relative to 100 parts by mass of the inorganic filler. When the amount of the coupling agent is 0.05 parts by mass or more relative to 100 parts by mass of the inorganic filler, the adhesiveness to the frame tends to be further improved. When the amount of the coupling agent is 5 parts by mass or less relative to 100 parts by mass of the inorganic filler, the moldability of the package tends to be further improved.

[0082] (Ion Exchanger) The encapsulating resin composition may contain an ion exchanger. From the viewpoint of improving the moisture resistance and high-temperature storage characteristics of a semiconductor device including an element to be encapsulated, the encapsulating resin composition preferably contains an ion exchanger. The ion exchanger is not particularly limited, and conventionally known ion exchangers can be used. Specific examples include hydrotalcite compounds, and hydrated oxides of at least one element selected from the group consisting of magnesium, aluminum, titanium, zirconium and bismuth. One type of ion exchanger may be used alone, or two or more types may be used in combination. Among these, hydrotalcite represented by the following general formula (A) is preferred.

[0083] Mg (1-X) Al X (OH)2(CO3) X / 2 ·mH2O ……(A) (0<X≦0.5, m is a positive number)

[0084] When the encapsulating resin composition contains an ion exchanger, the content thereof is not particularly limited as long as it is an amount sufficient to trap ions such as halogen ions. For example, the content is preferably 0.1 parts by mass to 30 parts by mass relative to 100 parts by mass of the resin component (total amount of epoxy resin and curing agent) , more preferably 1 part by mass to 10 parts by mass.

[0085] (Release Agent) The sealing resin composition may contain a release agent to obtain good release properties from the mold during molding. The release agent is not particularly limited, and conventionally known ones can be used. Specifically, examples include carnauba wax, higher fatty acids such as montanic acid and stearic acid, higher fatty acid metal salts, ester waxes such as montanic acid esters, and polyolefin waxes such as oxidized polyethylene and non-oxidized polyethylene. The release agent may be used alone or in combination of two or more types.

[0086] If the sealing resin composition contains a release agent, the amount is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the resin component (total amount of epoxy resin and curing agent). When the amount of release agent is 0.01 parts by mass or more per 100 parts by mass of the resin component, sufficient release properties tend to be obtained. When it is 10 parts by mass or less, better adhesion tends to be obtained.

[0087] (Flame retardant) The sealing resin composition may contain a flame retardant. The flame retardant is not particularly limited, and conventionally known ones can be used. Specifically, examples include organic or inorganic compounds containing halogen atoms, antimony atoms, nitrogen atoms, or phosphorus atoms, and metal hydroxides. The flame retardant may be used alone or in combination of two or more types.

[0088] If the sealing resin composition contains a flame retardant, the amount is not particularly limited as long as it is sufficient to obtain the desired flame retardant effect. For example, it is preferably 1 to 30 parts by mass, and more preferably 2 to 20 parts by mass, per 100 parts by mass of the resin component (total amount of epoxy resin and curing agent).

[0089] (Coloring agent) The sealing resin composition may contain a coloring agent. Examples of known coloring agents include carbon black, organic dyes, organic pigments, titanium dioxide, red lead, and red iron oxide. The amount of coloring agent can be appropriately selected depending on the purpose. One coloring agent may be used alone, or two or more coloring agents may be used in combination.

[0090] [Method for preparing a encapsulating resin composition] The method for preparing the encapsulating resin composition is not particularly limited. A common method involves thoroughly mixing predetermined amounts of components using a mixer or the like, then melt-kneading them using a mixing roll, extruder, or the like, followed by cooling and pulverization. More specifically, for example, a method involves stirring and mixing predetermined amounts of the above-mentioned components, then kneading them using a kneader, roll, extruder, or the like that has been preheated to 70°C to 140°C, followed by cooling and pulverization.

[0091] The sealing resin composition is preferably solid at room temperature and atmospheric pressure (for example, 25°C and atmospheric pressure). The shape of the sealing resin composition when it is solid is not particularly limited and can be in powder, granular, or tablet form. When the sealing resin composition is in tablet form, its dimensions and mass are preferably such that they are suitable for the packaging molding conditions, from the viewpoint of ease of handling.

[0092] - Semiconductor Devices - One embodiment of the present disclosure is a semiconductor device comprising a semiconductor element and a cured product of the sealing resin composition of the present disclosure, which is formed by sealing the semiconductor element.

[0093] Examples of semiconductor devices include those in which semiconductor elements (active elements such as semiconductor chips, transistors, diodes, and thyristors, and passive elements such as capacitors, resistors, and coils) are mounted on support members such as lead frames, pre-wired tape carriers, wiring boards, glass, silicon wafers, and organic substrates, and the resulting element section is sealed with a sealing resin composition. More specifically, common resin-encapsulated ICs such as DIP (Dual Inline Package), 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) have a structure in which semiconductor elements are fixed on a lead frame, the terminals of the semiconductor elements such as bonding pads and the leads of the semiconductor elements are connected by wire bonding, bumps, etc., and then the semiconductor elements are encapsulated by transfer molding, etc., using an encapsulating resin composition; TCP (Tape Carrier Package) has a structure in which semiconductor elements connected to a tape carrier by bumps are encapsulated with an encapsulating resin composition; and COB (Chip On) has a structure in which semiconductor elements connected to wiring formed on a support member by wire bonding, flip-chip bonding, solder, etc., are encapsulated with an encapsulating resin composition. Examples of such modules include boards, hybrid ICs, and multi-chip modules; BGAs (Ball Grid Arrays), CSPs (Chip Size Packages), and MCPs (Multi Chip Packages) which have a structure in which semiconductor elements are mounted on the surface of a support member having terminals for connecting to a wiring board formed on the back surface, the semiconductor elements are connected to the wiring formed on the support member by bump or wire bonding, and then the semiconductor elements are sealed with a sealing resin composition. Furthermore, sealing resin compositions can also be suitably used in printed wiring boards.

[0094] -Manufacturing method for semiconductor devices- The method for manufacturing a semiconductor device according to the present disclosure is not particularly limited and may include the steps of: arranging a semiconductor element on a support member; and encapsulating the semiconductor element with the encapsulation resin composition according to the present disclosure.

[0095] The method for carrying out each of the above steps is not particularly limited and can be carried out using general methods. Furthermore, the types of support members and semiconductor elements used in the manufacture of semiconductor devices are not particularly limited and can be those commonly used in the manufacture of semiconductor devices.

[0096] The method for encapsulating electronic components using the encapsulating resin composition of this disclosure is not particularly limited and can be selected according to the application. For example, it can be carried out by known molding methods such as transfer molding. Examples of electronic components include ICs, LSIs, power devices, and the like. [Examples]

[0097] The present invention will be described in more detail below based on examples, but the present invention is not limited to the following examples. The materials, amounts used, proportions, processing procedures, etc., shown in the following examples can be modified as appropriate without departing from the spirit of this disclosure. Unless otherwise specified, "parts" means "parts by mass".

[0098] -Preparation of sealing resin composition- The following components were mixed in the proportions (parts by mass) shown in Table 1 to prepare the sealing resin compositions for the examples and comparative examples.

[0099] • Epoxy resin 1: Biphenyl aralkyl type epoxy resin, epoxy equivalent 275 g / eq (Nippon Kayaku Co., Ltd., product name "NC-3000") • Epoxy resin 2: Biphenyl-type epoxy resin, epoxy equivalent 192 g / eq (Mitsubishi Chemical Corporation, product name "YX-4000")

[0100] • Hardener 1: Biphenyl aralkyl type phenolic resin (hydroxyl group equivalent 199g / eq, Air Water Inc., product name "HE200C-10") • Hardener 2: Active ester compound (DIC Corporation, product name "EXB-8") • Hardening agent 3: Nitrogen-containing phenolic compound (melamine-modified phenolic resin, hydroxyl group equivalent 120 g / eq, manufactured by Hitachi Chemical Co., Ltd., product name "HPM-J3", has three nitrogen atoms as atoms constituting the heterocyclic skeleton.) • Hardener 4: Nitrogen-containing phenol compound (benzotriazole-phenol compound, hydroxyl group equivalent 323 g / eq, manufactured by Cipro Chemical Co., Ltd., product name "SEE S ORB709 has three nitrogen atoms as atoms that make up its heterocyclic skeleton. • Curing agent 5: Nitrogen-containing phenol compound (benzotriazole-phenol compound, hydroxyl group equivalent 441 g / eq, manufactured by BASF, product name "Tinuvin928", has three nitrogen atoms as atoms constituting the heterocyclic skeleton.) • Hardener 6: Nitrogen-containing phenolic compound ( Triazine -Phenol compound, hydroxyl group equivalent 509 g / eq, manufactured by Sun Chemical Co., Ltd., product name "Ciasorb UV1164", has three nitrogen atoms as atoms constituting the heterocyclic skeleton.

[0101] • Curing accelerator: p-benzoquinone adduct of triphenylphosphine • Coupling agent: N-phenyl-3-aminopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., product name "KBM-573") • Release agent: Montane ester wax (Clariant Japan Co., Ltd., product name "HW-E") • Coloring agent: Carbon black (Mitsubishi Chemical Corporation, product name "MA600") • Inorganic filler: Silica filler (Denka Co., Ltd., product name "FB-9454FC", average particle size 18 μm)

[0102] [Evaluation of cured products of sealing resin compositions] Each example of the sealing resin composition, formulated according to the composition ratios shown in Table 1, was evaluated using the following test items. The evaluation results are shown in Table 1 below. Unless otherwise specified, the curable resin compositions were molded using a transfer molding machine at a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds. Post-curing was also performed at 175°C for 6 hours as needed.

[0103] (Relative permittivity and dielectric loss tangent) The sealing resin composition was loaded into a transfer molding machine and molded under the conditions of a mold temperature of 180°C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds. Post-curing was carried out at 175°C for 6 hours to obtain a rod-shaped cured product (length 0.8 mm, width 0.6 mm, thickness 90 mm). Using this cured product as a test specimen, the relative permittivity and dielectric loss tangent were measured at 20 GHz at a temperature of 25 ± 1°C using a cavity resonator (Kanto Electronics Applied Development Co., Ltd., "CP561") and a network analyzer (Keysight Technologies, Inc., "PNA E8364B").

[0104] (Hardness when heated) The epoxy resin compositions prepared in each example were molded into discs with a diameter of 50 mm and a thickness of 3 mm under the above conditions, and immediately after molding, the hardness was measured using a Shore D type durometer (Polymer Instruments Co., Ltd., ASKER, Type D durometer).

[0105] (260℃ shear bonding) force ) The curable resin composition was molded on a silicon nitride substrate under the above conditions to a size of 4 mm in diameter at the bottom, 3 mm in diameter at the top, and 4 mm in height, and then post-cured under the above conditions. Subsequently, a bond tester (Nordson Advanced Technologies, Inc., Series 4000) was used. Silicon nitride substrate The shear adhesion strength (MPa) was determined at a shear rate of 50 μm / s while maintaining the temperature at 260°C.

[0106] [Table 1]

[0107] As shown in Table 1, the encapsulating resin composition of the example was found to improve the adhesion of silicon nitride to the substrate while maintaining a lower dielectric loss tangent at 20 GHz compared to the encapsulating resin composition of the comparative example.

Claims

1. Epoxy resin and A curing agent containing an active ester compound and a nitrogen-containing phenol compound, It contains, A resin composition for transfer molding and sealing, wherein at least one of the nitrogen-containing phenol compounds is a compound having a nitrogen-containing heterocycle.

2. The resin composition for transfer molding and sealing according to claim 1, wherein the hydroxyl group equivalent of the nitrogen-containing phenol compound is 100 g / eq or more.

3. The resin composition for transfer molding and sealing according to claim 1 or claim 2, wherein the compound having a nitrogen-containing heterocycle has two or more nitrogen atoms as atoms constituting the heterocycle skeleton.

4. The resin composition for transfer molding and sealing according to any one of claims 1 to 3, wherein the content of the nitrogen-containing phenol compound is 15% by mass or less with respect to the total amount of the curing agent.

5. A resin composition for transfer molding and encapsulation according to any one of claims 1 to 4, further comprising an inorganic filler.

6. The resin composition for transfer molding and sealing according to claim 5, wherein the content of the inorganic filler is 65% by volume or more in the resin composition for sealing.

Images