WO2019216388A1

WO2019216388A1 - Curable composition, material for protecting semiconductor element, and semiconductor device

Info

Publication number: WO2019216388A1
Application number: PCT/JP2019/018624
Authority: WO
Inventors: 貴史西村; 秀中村; 小林　祐輔
Original assignee: 積水化学工業株式会社
Priority date: 2018-05-10
Filing date: 2019-05-09
Publication date: 2019-11-14
Also published as: TW202003680A

Abstract

The present invention is a curable composition including an epoxy compound (A), a curing agent (B) which is liquid at 23°C, an inorganic filler (C) which has a thermal conductivity of 10 W/m∙K or greater and is spherical, and an ion exchanger (X), the ion exchanger (X) comprising a zirconium-based cation exchanger and a bismuth-based anion exchanger. Through the present invention, it is possible to provide a curable composition having excellent heat dissipation properties, insulating reliability, and application properties.

Description

Curable composition, semiconductor element protecting material, and semiconductor device

The present invention relates to a curable composition, a semiconductor element protecting material comprising the curable composition, and a semiconductor device using the semiconductor element protecting material.

In recent years, the performance of semiconductor devices has been improved, and accordingly, it is necessary to dissipate heat generated from semiconductor elements that constitute the semiconductor devices.
For example, in Patent Document 1, a flexible epoxy compound, an epoxy compound different from the flexible epoxy compound, a curing agent that is liquid at 23 ° C., a curing accelerator, and a thermal conductivity of 10 W / m · K or more. In addition, a material for protecting a semiconductor element containing a spherical inorganic filler is disclosed, and it is shown that heat dissipation is good.
On the other hand, when such a material for protecting a semiconductor element is used on a circuit board on which the semiconductor element is mounted, the heat dissipation is good, but the metal migration (metal movement) constituting the wiring on the circuit board when a voltage is applied. ) May cause a short circuit, and it is necessary to improve insulation reliability.
From this point of view, Patent Document 2 discloses a semiconductor element protecting material containing an ion trapping agent made of an ion exchanger, which shows that the insulation reliability is improved.

Japanese Patent No. 5766867 JP 2017-41633 A

However, when the semiconductor element protecting material of Patent Document 2 is used, although certain insulation reliability is ensured, there is also a demand for narrower intervals between circuit board wiring, and thus better insulation reliability is required. ing. In particular, in a copper circuit board, a short circuit problem due to migration is likely to occur, and a material that does not easily cause such a problem is demanded.
Accordingly, an object of the present invention is to provide a curable composition excellent in heat dissipation, insulation reliability, and coatability, a semiconductor element protecting material comprising the curable composition, and a semiconductor device using the semiconductor element protecting material. It is to provide.

As a result of intensive studies to achieve the above object, the present inventors have found that a specific inorganic filler (C) having a thermal conductivity of a certain level or more in addition to the epoxy compound (A) and its curing agent (B). ) And the curable composition containing the specific ion exchanger (X), the present inventors have found that the above problems can be solved, and completed the present invention.
That is, the present invention relates to the following [1] to [8].
[1] An epoxy compound (A), a curing agent (B) that is liquid at 23 ° C., a spherical inorganic filler (C) having a thermal conductivity of 10 W / m · K or more, an ion exchanger ( X), and the ion exchanger (X) is composed of a zirconium-based cation exchanger and a bismuth-based anion exchanger.
[2] The curable composition according to the above [1], wherein the epoxy compound (A) is a flexible epoxy compound (a1).
[3] The curable composition according to the above [2], wherein the flexible epoxy compound (a1) is a polyalkylene glycol diglycidyl ether having a structural unit in which 9 or more alkylene glycol groups are repeated.
[4] The curable composition according to any one of [1] to [3], wherein the curing agent (B) is an allylphenol novolak compound.
[5] The curable composition according to any one of [1] to [4], wherein the inorganic filler (C) is at least one selected from the group consisting of alumina, aluminum nitride, and silicon carbide. .
[6] A semiconductor element protecting material comprising the curable composition according to any one of [1] to [5].
[7] A semiconductor element, and a cured product disposed on the first surface of the semiconductor element, wherein the cured product is formed by curing the semiconductor element protecting material according to [6]. A semiconductor device.
[8] The semiconductor element has a first electrode on a second surface side opposite to the first surface side, and the first electrode of the semiconductor element has a second electrode on the surface. The semiconductor device according to [7], which is electrically connected to the second electrode in the connection target member.

ADVANTAGE OF THE INVENTION According to this invention, the curable composition excellent in heat dissipation, insulation reliability, and application | coating property, the semiconductor element protection material which consists of this curable composition, and the semiconductor device using this semiconductor element protection material are provided. be able to.

1 is a schematic cross-sectional view of a semiconductor device using a semiconductor element protecting material according to a first embodiment of the present invention.

The curable composition of the present invention comprises an epoxy compound (A), a curing agent (B) that is liquid at 23 ° C., and an inorganic filler (C) that has a thermal conductivity of 10 W / m · K or more and is spherical. And an ion exchanger (X), and the ion exchanger (X) is composed of a zirconium-based cation exchanger and a bismuth-based anion exchanger.

[Ion exchanger (X)]
The curable composition of the present invention contains an ion exchanger (X) composed of a zirconium-based cation exchanger and a bismuth-based anion exchanger. By containing the ion exchanger (X), the insulation reliability of the curable composition can be improved.
Although the reason why the insulation reliability is increased by using the ion exchanger (X) is not clear, it is a cause of causing migration of wiring of an organic acid or the like considered to be contained in the epoxy compound (A) or the like. It is presumed that this substance can be effectively captured.

From the viewpoint of improving the insulation reliability of the curable composition, the median diameter of the ion exchanger (X) is preferably 0.1 μm or more, more preferably 0.3 μm or more, and preferably 10 μm or less. More preferably, it is 3 μm or less, and further preferably 1 μm or less. The median diameter is the particle diameter (cumulative average diameter) at which the cumulative curve becomes 50% when the cumulative curve is obtained with the total volume of one group of particles as 100%. The median diameter can be measured using a laser diffraction scattering method.

The average primary particle size of the ion exchanger (X) is preferably 0.1 to 2 μm, more preferably 0.2 to 1 μm, from the viewpoint of improving the insulation reliability of the curable composition. It is preferably 0.2 to 0.7 μm.
The average primary particle diameter is obtained by observing 20 inorganic fillers arbitrarily selected with an electron microscope, a laser microscope, or an optical microscope, measuring the particle diameter of each inorganic filler, and calculating the average value. . The particle size of the inorganic filler was determined by observing the cross section of the curable composition or the cured product of the curable composition with an electron microscope, a laser microscope, or an optical microscope, and 20 inorganic fillers arbitrarily selected. It can also be determined by measuring the particle diameter of the slag and calculating the average value.

From the viewpoint of obtaining the above average primary particle size range, the ion exchanger (X) is preferably refined. The miniaturization can be performed by a known means such as a pulverizer. By miniaturization, it becomes easier to capture a substance that causes migration, and it is considered that the insulation reliability of the curable composition is increased.

The neutral exchange capacity of the ion exchanger (X) is preferably 1 meq / g or more, more preferably 2 meq / g or more.

The ion exchanger (X) is composed of a zirconium-based cation exchanger and a bismuth-based anion exchanger. The ion exchanger (X) may preferably be composed of a zirconium-based cation exchanger and a bismuth-based anion exchanger, which are separate compounds, or a zirconium-based cation exchange in one compound. It may have a part that functions as a body and a part that functions as a bismuth anion exchanger.
The curable composition of this invention can obtain the outstanding insulation reliability by including the ion exchanger (X) which consists of a zirconium-type cation exchanger and a bismuth-type anion exchanger.

The zirconium-based cation exchanger is, for example, a compound containing zirconium and a compound having an acid group such as a sulfonic acid group, a carboxy group, or a phosphoric acid group. From the viewpoint of improving the insulation reliability of the curable composition, the zirconium cation exchanger is preferably a zirconium phosphate cation exchanger.
Among the zirconium phosphate-based cation exchangers, compounds represented by ZrH _a (PO ₄ ) _b · nH ₂ 0 (formula 1) are preferable. Here, in Formula 1, a and b are positive numbers satisfying 3b−a = 4, b is 2 <b ≦ 2.1, and n is 0 ≦ n ≦ 2.

The bismuth anion exchanger is an anion exchanger containing bismuth, and from the viewpoint of improving the insulation reliability of the curable composition, bismuth hydrous oxide and bismuth hydroxide nitrate are preferred. Bismuth is more preferred. The hydrated oxide of bismuth is represented by, for example, Bi ₂ O ₃ .nH ₂ O (0 <n ≦ 4), and the bismuth hydroxide nitrate is, for example, Bi (OH) _x (NO ₃ ) _y · nH _2. O (Expression 2). In Expression 2, x is a positive number not less than 2.5 and less than 3, y is a positive number not more than 0.5, satisfies the value of x + y = 3, and n is 0 or a positive number.

The amount of the ion exchanger (X) in the curable composition is preferably 0.08% by mass or more, more preferably 0.1% by mass or more, in 100% by mass of the curable composition. More preferably, it is 0.3% by mass or more, and preferably 3% by mass or less, and more preferably 2% by mass or less.

When the ion exchanger (X) is composed of a zirconium-based cation exchanger and a bismuth-based anion exchanger, which are separate compounds, the blending ratio of the zirconium-based cation exchanger and the bismuth-based anion exchanger (zirconium-based) (Cation exchanger: bismuth-based anion exchanger) is preferably 99: 1 to 1:99 on a mass basis. The blending ratio is more preferably 10:90 to 80:20, and still more preferably 20:80 to 60:40.

In the case where the ion exchanger (X) comprises a zirconium-based cation exchanger and a bismuth-based anion exchanger, which are separate compounds, the method for blending the zirconium-based cation exchanger and the bismuth-based anion exchanger is as follows. It is as follows. That is, when preparing the curable composition, the zirconium-based cation exchanger and the bismuth-based anion exchanger may be blended separately, or both of them are mixed in advance, and the zirconium-based cation exchanger and the bismuth-based composition are mixed. An ion exchanger (X) made of a mixture of anion exchangers may be prepared and mixed with an epoxy compound (A), a curing agent (B), an inorganic filler (C), and the like.
From the viewpoint of improving the insulation reliability of the curable composition, an ion exchanger (X) comprising a mixture of a zirconium-based cation exchanger and a bismuth-based anion exchanger is prepared in advance, and this is converted into an epoxy compound (A). The aspect which mixes with a hardening | curing agent (B), an inorganic filler (C), etc., and produces a curable composition is preferable. As described above, since the ion exchanger (X) is preferably refined, an ion exchanger (X) composed of a mixture of a zirconium-based cation exchanger and a bismuth-based anion exchanger is prepared. It is more preferable to prepare a curable composition after miniaturization.

In addition, the curable composition of this invention may contain ion exchangers other than the said ion exchanger (X) in the range which does not inhibit the effect of this invention.

[Epoxy compound (A)]
The curable composition of this invention contains an epoxy compound (A). By containing the epoxy compound (A), thermosetting can be imparted to the curable composition.

(Flexible epoxy compound (a1))
The epoxy compound (A) preferably contains a flexible epoxy compound (a1). By using the flexible epoxy compound (a1), when the curable composition of the present invention is used as a material for protecting a semiconductor element, the semiconductor element is hardly damaged due to deformation stress on the semiconductor element, and the like. The material for protecting a semiconductor element can be made difficult to peel from the surface of the semiconductor element. As an index of flexibility in a flexible epoxy compound, it is defined as an epoxy resin having a durometer ShoreD measurement of 30 or less when cured with a stoichiometric amount of diethylenetriamine (“DETA”). .
It is preferable that the flexible epoxy compound (a1) does not have an aromatic skeleton and an alicyclic skeleton.
Examples of the flexible epoxy compound (a1) include polyalkylene glycol diglycidyl ether, polybutadiene diglycidyl ether, and sulfide-modified epoxy resin. From the viewpoint of further improving the coating property, polyalkylene glycol diglycidyl ether is preferable.

From the viewpoint of further increasing the flexibility of the cured product of the curable composition and improving the adhesive force, the polyalkylene glycol diglycidyl ether preferably has a structural unit in which 9 or more alkylene glycol groups are repeated. The upper limit of the number of repeating alkylene glycol groups is not particularly limited. The number of repeating alkylene glycol groups may be 30 or less. The alkylene glycol group preferably has 2 or more carbon atoms, preferably 5 or less.

Examples of the polyalkylene glycol diglycidyl ether include polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polytetramethylene glycol diglycidyl ether.
Only 1 type may be used for a flexible epoxy compound (a1), and it may use 2 or more types together.

In 100% by mass of the curable composition, the content of the flexible epoxy compound (a1) is preferably 3% by mass or more, more preferably 5% by mass or more, preferably 10% by mass or less, more preferably 8%. It is below mass%. The softness | flexibility of the hardened | cured material of a curable composition becomes it still higher that content of a flexible epoxy compound (a1) is more than the said minimum. When the content of the flexible epoxy compound (a1) is not more than the above upper limit, the applicability of the curable composition is further enhanced.

(Other epoxy compounds (a2))
As an epoxy compound (A), other epoxy compounds (a2) other than the said flexible epoxy compound (a1) may be contained.
As another epoxy compound (a2), an epoxy compound having an aromatic skeleton or an alicyclic skeleton is preferable.

As an epoxy compound having an aromatic skeleton, an epoxy compound having a bisphenol skeleton, an epoxy compound having a naphthalene skeleton, an epoxy compound having a fluorene skeleton, an epoxy compound having a biphenyl skeleton, an epoxy compound having a bi (glycidyloxyphenyl) methane skeleton , An epoxy compound having a xanthene skeleton, an epoxy compound having an anthracene skeleton, an epoxy compound having a pyrene skeleton, and the like.
Examples of the epoxy compound having an alicyclic skeleton include an epoxy compound having a dicyclopentadiene skeleton and an epoxy compound having an adamantane skeleton.
In addition, hydrogenated products or modified products of the above-exemplified epoxy compounds can also be used as other epoxy compounds (a2).
Among these, the other epoxy compound (a2) is preferably an epoxy compound having a bisphenol skeleton (bisphenol type epoxy compound).

Examples of the epoxy compound having a bisphenol skeleton include an epoxy compound having a bisphenol A type, bisphenol F type, or bisphenol S type bisphenol skeleton.

Examples of the epoxy compound having a naphthalene skeleton include 1-glycidylnaphthalene, 2-glycidylnaphthalene, 1,2-diglycidylnaphthalene, 1,5-diglycidylnaphthalene, 1,6-diglycidylnaphthalene, 1,7-diglycidyl. Examples include naphthalene, 2,7-diglycidylnaphthalene, triglycidylnaphthalene, and 1,2,5,6-tetraglycidylnaphthalene.

Examples of the epoxy compound having a fluorene skeleton include 9,9-bis (4-glycidyloxyphenyl) fluorene, 9,9-bis (4-glycidyloxy-3-methylphenyl) fluorene, and 9,9-bis (4- Glycidyloxy-3-chlorophenyl) fluorene, 9,9-bis (4-glycidyloxy-3-bromophenyl) fluorene, 9,9-bis (4-glycidyloxy-3-fluorophenyl) fluorene, 9,9-bis (4-Glycidyloxy-3-methoxyphenyl) fluorene, 9,9-bis (4-glycidyloxy-3,5-dimethylphenyl) fluorene, 9,9-bis (4-glycidyloxy-3,5-dichlorophenyl) Fluorene and 9,9-bis (4-glycidyloxy-3,5-dibromophenyl) Fluorene, and the like.

Examples of the epoxy compound having a biphenyl skeleton include 4,4'-diglycidylbiphenyl and 4,4'-diglycidyl-3,3 ', 5,5'-tetramethylbiphenyl.

Examples of the epoxy compound having a bi (glycidyloxyphenyl) methane skeleton include 1,1′-bi (2,7-glycidyloxynaphthyl) methane, 1,8′-bi (2,7-glycidyloxynaphthyl) methane, 1,1′-bi (3,7-glycidyloxynaphthyl) methane, 1,8′-bi (3,7-glycidyloxynaphthyl) methane, 1,1′-bi (3,5-glycidyloxynaphthyl) methane 1,8'-bi (3,5-glycidyloxynaphthyl) methane, 1,2'-bi (2,7-glycidyloxynaphthyl) methane, 1,2'-bi (3,7-glycidyloxynaphthyl) And methane and 1,2′-bi (3,5-glycidyloxynaphthyl) methane.

Examples of the epoxy compound having a xanthene skeleton include 1,3,4,5,6,8-hexamethyl-2,7-bis-oxiranylmethoxy-9-phenyl-9H-xanthene.

Examples of the epoxy compound having a dicyclopentadiene skeleton include dicyclopentadiene dioxide and a phenol novolac epoxy compound having a dicyclopentadiene skeleton.

Examples of the epoxy compound having an adamantane skeleton include 1,3-bis (4-glycidyloxyphenyl) adamantane and 2,2-bis (4-glycidyloxyphenyl) adamantane.

In 100% by mass of the curable composition, the content of the other epoxy compound (a2) is preferably 1% by mass or more, more preferably 2% by mass or more, preferably 10% by mass or less, more preferably 8% by mass. % Or less. When the content of the other epoxy compound (a2) is not less than the above lower limit and not more than the above upper limit, the applicability of the curable composition, the flexibility of the cured product, and the moisture resistance are further improved. Adhesiveness to is further improved, and sticking to the protective film can be further suppressed.

As an epoxy compound (A), it is preferable to contain both a flexible epoxy compound (a1) and another epoxy compound (a2).
In 100% by mass of the curable composition, the total content of the flexible epoxy compound (a1) and the other epoxy compound (a2) is preferably 5% by mass or more, more preferably 8% by mass or more, preferably Is 15% by mass or less, more preferably 12% by mass or less. When the total content of the flexible epoxy compound (a1) and the other epoxy compound (a2) is not less than the above lower limit and not more than the above upper limit, applicability of the curable composition, flexibility of the cured product, and moisture resistance Becomes even better, and the adhesion of the cured product of the curable composition to the semiconductor element becomes even better. Moreover, when sticking a protective film on the hardened | cured material of a curable composition, sticking with respect to a protective film can be suppressed.

The content of the other epoxy compound (a2) is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, preferably 100 parts by mass or less, relative to 100 parts by mass of the flexible epoxy compound (a1). More preferably, it is 90 mass parts or less. When the content of the epoxy compound (a2) is not less than the above lower limit, the applicability of the curable composition is further enhanced, and the adhesiveness of the cured product to the semiconductor element is further enhanced. When the content of the other epoxy compound (a2) is not more than the above upper limit, the flexibility of the cured product is further increased.

[Curing agent (B)]
The curable composition of this invention contains the hardening | curing agent (B) which is a liquid at 23 degreeC. By using a hardening | curing agent (B), an epoxy compound (A) can be hardened and the applicability | paintability of a curable composition can be improved.
Examples of the curing agent (B) include an amine compound (amine curing agent), an imidazole compound (imidazole curing agent), a phenol compound (phenol curing agent), and an acid anhydride (acid anhydride curing agent). Among these, it is preferable to use a phenol compound.

Examples of the phenol compound include phenol novolak compounds, o-cresol novolak compounds, p-cresol novolak compounds, t-butylphenol novolak compounds, allylphenol novolak compounds, dicyclopentadiene cresol compounds, polyparavinylphenol compounds, and bisphenol A type novolak compounds. And xylylene-modified novolak compounds, decalin-modified novolak compounds, poly (di-o-hydroxyphenyl) methane compounds, poly (di-m-hydroxyphenyl) methane, and poly (di-p-hydroxyphenyl) methane.
Among these, it is preferable to use an allylphenol novolak compound from the viewpoint of improving the coating property of the curable composition, suppressing the generation of voids in the cured product, and increasing the heat resistance of the cured product.

The content of the curing agent (B) with respect to 100 parts by mass of the epoxy compound (A) is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 40 parts by mass or more, preferably 100 It is at most 80 parts by mass, more preferably at most 60 parts by mass. When the content of the curing agent (B) is not less than the above lower limit, the curable composition can be cured well. When the content of the curing agent (B) is not more than the above upper limit, the residual amount of the curing agent (B) that has not contributed to curing in the cured product is reduced.

[Inorganic filler (C)]
The curable composition of the present invention contains an inorganic filler (C) having a thermal conductivity of 10 W / m · K or more and a spherical shape. By containing this inorganic filler (C), the heat dissipation of hardened | cured material can be improved, maintaining the applicability | paintability of a curable composition, and the softness | flexibility of the hardened | cured material highly. The shape of the inorganic filler (C) is spherical. Here, the spherical shape means that the aspect ratio (major axis / minor axis) is 1 or more and 2 or less.
From the viewpoint of further improving the heat dissipation of the cured product, the thermal conductivity of the inorganic filler (C) is preferably 12 W / m · K or more, more preferably 15 W / m · K or more, and even more preferably 20 W / m ·. K or more. The upper limit of the thermal conductivity of the inorganic filler (C) is not particularly limited. Inorganic fillers having a thermal conductivity of about 300 W / m · K are widely known, and inorganic fillers having a thermal conductivity of about 200 W / m · K are easily available.
The thermal conductivity can be measured by, for example, a periodic heating thermoreflectance method using a thermal microscope manufactured by Bethel Co., Ltd. with respect to a filler cross-section cut by a cross section polisher.

From the viewpoint of effectively increasing the heat dissipation of the cured product, the inorganic filler (C) is preferably at least one selected from the group consisting of alumina, aluminum nitride, and silicon carbide. As the inorganic filler (C), inorganic fillers other than those described above may be used as appropriate. When using an inorganic filler (C), only 1 type may be used and 2 or more types may be used together.

The average particle diameter of the inorganic filler (C) is preferably 0.1 μm or more, and preferably 150 μm or less. When the average particle diameter of the inorganic filler (C) is not less than the above lower limit, the inorganic filler (C) can be easily filled at a high density. The applicability | paintability of a curable composition becomes it favorable that the average particle diameter of an inorganic filler (C) is below the said upper limit.
The average particle diameter of the inorganic filler (C) is an average particle diameter obtained from a particle size distribution measurement result with a volume average measured by a laser diffraction particle size distribution measuring apparatus.

The content of the inorganic filler (C) in 100% by mass of the curable composition is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 82% by mass or more. Yes, and preferably 92% by mass or less, more preferably 90% by mass or less. When the content of the inorganic filler (C) is at least the above lower limit, the heat dissipation of the cured product is further enhanced. When the content of the inorganic filler (C) is not more than the above upper limit, the applicability of the curable composition is further enhanced, and the properties of the cured product are further improved.

[Curing accelerator (D)]
The curable composition of the present invention may contain a curing accelerator (D). By using the curing accelerator (D), the curing rate can be increased and the curable composition can be efficiently cured. As for a hardening accelerator (D), only 1 type may be used and 2 or more types may be used together.
Examples of the curing accelerator (D) include imidazole compounds, phosphorus compounds, amine compounds, and organometallic compounds. In addition, other examples include 1,8-diazabicyclo (5,4,0) -7-undecenes. Of these, imidazole compounds and 1,8-diazabicyclo (5,4,0) -7-undecenes are preferred because the effects of the present invention are further improved.

Examples of the imidazole compound include 2-undecylimidazole, 2-heptadecylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl- 2-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-un Decylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6- [2 ' -Mechi Imidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-undecylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-Ethyl-4′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine Isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-dihydroxymethylimidazole, etc. Is mentioned.

Also, known imidazole-based latent curing agents can be used. Specific examples include PN23, PN40, and PN-H (trade names, all manufactured by Ajinomoto Fine Techno Co., Ltd.). In addition, curing accelerators which are referred to as microencapsulated imidazoles and subjected to addition reaction with the hydroxyl group of the epoxy adduct of the amine compound can be mentioned, for example, NovaCure HX-3088, NovaCure HX-3941, HX-3742, HX-3722 (trade name, Asahi Kasei E-Materials Co., Ltd.). Furthermore, inclusion imidazole can also be used. A specific example is TIC-188 (trade name, manufactured by Nippon Soda Co., Ltd.).

Examples of the phosphorus compound include triphenylphosphine.

Examples of the amine compound include 2,4,6-tris (dimethylaminomethyl) phenol, diethylamine, triethylamine, diethylenetetramine, triethylenetetramine, and 4,4-dimethylaminopyridine.

Examples of the organometallic compound include zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II), and trisacetylacetonate cobalt (III).

Examples of the above 1,8-diazabicyclo (5,4,0) -7-undecenes include octyl salts of 1,8-diazabicyclo (5,4,0) -7-undecene. Is SA-102 (trade name, manufactured by San Apro).

The content of the curing accelerator (D) with respect to 100 parts by mass of the epoxy compound (A) is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and preferably 10 parts by mass or less. More preferably, it is 8 parts by mass or less. When the content of the curing accelerator (D) is not less than the above lower limit, the curable composition can be cured well. When the content of the curing accelerator (D) is not more than the above upper limit, the residual amount of the curing accelerator that has not contributed to curing in the cured product is reduced.

[Coupling agent (E)]
The curable composition of the present invention preferably contains a coupling agent (E). The use of the coupling agent (E) further increases the moisture resistance of the cured product of the curable composition. As for a coupling agent (E), only 1 type may be used and 2 or more types may be used together.

In 100% by mass of the curable composition, the content of the coupling agent (E) is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, preferably 2% by mass or less, more preferably 1% by mass or less. When the content of the coupling agent (E) is at least the above lower limit, the moisture resistance of the cured product of the curable composition is further enhanced. When the content of the coupling agent (E) is not more than the above upper limit, the applicability of the curable composition is further enhanced.

(Other ingredients)
The curable composition of the present invention, if necessary, a natural wax such as carnauba wax, a synthetic wax such as polyethylene wax, a higher fatty acid such as stearic acid or zinc stearate and a release agent such as a metal salt thereof or paraffin, Various additives such as a colorant such as carbon black and bengara may be included. In addition to these, curable compositions include inorganic brominated epoxy resins, antimony trioxide, aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, phosphazene and other flame retardants, and bismuth oxide hydrates. Various additives such as an ion exchanger, a low stress component such as silicone oil and silicone rubber, a dispersant, and an antioxidant may be included.

Among these, the curable composition of the present invention preferably contains a dispersant. Specific examples of the dispersant include polycarboxylic acid salts, alkyl ammonium salts, alkylol ammonium salts, phosphate ester salts, acrylic blocks. Examples thereof include copolymers and polymer salts.

In 100% by mass of the curable composition, the content of the dispersant is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, preferably 2% by mass or less, more preferably 1% by mass. It is as follows.

The curable composition of the present invention may be diluted with a solvent selected from the group consisting of glycols, alcohols, ethers, esters, carboxylic acids, organic sulfur solvents, and mixtures thereof as necessary.
Specific examples of the solvent include dipropylene glycol methyl ether, ethylene glycol monobutyl ether acetate, methyl isobutyl ketone, 2-butoxyethanol, diethylene glycol monobutyl ether acetate, 4-methyl-1,3-dioxolan-2-one, dimethyl sulfoxide, N -Methyl-2-pyrrolidone, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, diethylene glycol ethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, phenol, terpineol, γ-butyrolactone, methyl succinate and methyl glutarate and dimethyl adipate Ester mixture containing butyl glycol acetate To the mixtures, and the like, but is not limited thereto.

The curable composition of the present invention is preferably used as a semiconductor element protecting material. The semiconductor element protecting material is preferably used as a sealing material for sealing a semiconductor element mounted on a circuit board. Examples of the circuit board include a circuit board in which a wiring pattern such as copper is formed on a flexible board such as a polyimide board, a glass board, a glass epoxy board or the like. Examples of semiconductor elements include LEDs and photodiodes.
The curable composition of the present invention is particularly excellent in heat dissipation, can effectively dissipate heat generated from the semiconductor element, and can suppress deterioration of the semiconductor element. Furthermore, the curable composition of the present invention can suppress migration of a circuit board, particularly a copper circuit board, and has high insulation reliability.
The curable composition of the present invention can also be used on a sealing material for protecting a semiconductor chip from temperature, humidity, dust and the like.
Examples of the sealing material include an epoxy molding compound and a silicone molding compound.

The semiconductor element protecting material is preferably used by being applied by a dispenser, spray coating, screen printing, vacuum screen printing, or a coating method using an inkjet apparatus. When the solvent is not included, it is preferable that the material for protecting a semiconductor element is used by being applied by a dispenser from the viewpoint of easy application and further prevention of formation of voids in the cured product. When it contains a solvent, it is preferably applied by spray coating.

The semiconductor device according to the present invention includes a semiconductor element and a cured product disposed on the first surface of the semiconductor element. In the semiconductor device according to the present invention, the cured product is formed by curing the semiconductor element protecting material. Since the said hardened | cured material protects a semiconductor element and is excellent in heat dissipation, it can thermally radiate the heat which generate | occur | produces from a semiconductor element, and can suppress degradation of a semiconductor element.

FIG. 1 is a schematic cross-sectional view of a semiconductor device using a semiconductor element protecting material according to the first embodiment of the present invention.
A semiconductor device 11 illustrated in FIG. 1 includes a semiconductor element 12 and a cured product 13 disposed on the first surface 12 a of the semiconductor element 12. The cured product 13 is formed by curing the above-described semiconductor element protecting material. The cured product 13 is disposed in a partial region on the first surface 12 a of the semiconductor element 12.

The semiconductor element 12 has a first electrode 12A on the second surface 12b side opposite to the first surface 12a side. The semiconductor device 11 further includes a connection target member 14. The connection target member 14 has a second electrode 14A on the surface 14a. The semiconductor element 12 and the connection target member 14 are bonded and fixed via another cured product 15 (connection portion). The first electrode 12 </ b> A of the semiconductor element 12 and the second electrode 14 </ b> A of the connection target member 14 face each other and are electrically connected by the conductive particles 16. The first electrode 12 </ b> A and the second electrode 14 </ b> A may be electrically connected by being in contact with each other. The hardened | cured material 13 is arrange | positioned on the 1st surface 12a on the opposite side to the side by which the 1st electrode 12A of the semiconductor element 12 is arrange | positioned.

A protective film 17 is disposed on the surface of the cured product 13 opposite to the semiconductor element 12 side. Thereby, not only the heat dissipation and the protection of the semiconductor element are enhanced by the cured product 13, but also the protection of the semiconductor element can be further enhanced by the protective film 17. The cured product 13 can suppress sticking of the cured product 13 to the protective film 17.

Examples of the connection target member include a glass substrate, a glass epoxy substrate, a flexible printed substrate, and a polyimide substrate.
Note that the structure shown in FIG. 1 is only an example of a semiconductor device, and the semiconductor device of the present invention is not limited to this. For example, the arrangement structure of the cured product of the semiconductor element protecting material can be appropriately changed.

Hereinafter, the present invention will be clarified by giving specific examples and comparative examples of the present invention. The present invention is not limited to the following examples.

The following materials were used.

(A1) Flexible epoxy compound EX-821 (repetition number 4 (n = 4)) (manufactured by Nagase ChemteX Corporation, polyethylene glycol diglycidyl ether, epoxy equivalent: 185)
EX-830 (repetition number 9 (n = 9)) (manufactured by Nagase ChemteX Corporation, polyethylene glycol diglycidyl ether, epoxy equivalent: 268)
EX-931 (repetition number 11 (n = 11)) (manufactured by Nagase ChemteX, polypropylene glycol diglycidyl ether, epoxy equivalent: 471)
EX-861 (repetition number 22 (n = 22)) (manufactured by Nagase ChemteX Corporation, polyethylene glycol diglycidyl ether, epoxy equivalent: 551)
PB3600 (manufactured by Daicel, polypudadiene-modified epoxy resin, epoxy equivalent: 200)

(A2) Other epoxy compounds (epoxy compounds having an aromatic skeleton or an alicyclic skeleton)
jER828 (Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent: 188)
jER834 (Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, softening point: 30 ° C., epoxy equivalent: 255)

(A2) Other epoxy compounds (epoxy compounds having no aromatic skeleton and alicyclic skeleton)
YH-434L (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., polyglycidylamine-modified epoxy resin, epoxy equivalent: 120)

(B) Curing agent Fuji Cure 7000 (Fuji Kasei Co., Ltd., liquid at 23 ° C., amine compound)
MEH-8005 (Maywa Kasei Co., Ltd., liquid at 23 ° C, allylphenol novolak compound)
TD-2131 (manufactured by DIC, solid at 23 ° C., phenol novolac compound)

(C) Inorganic filler FAN-f05 having a thermal conductivity of 10 W / m · K or more (Furukawa Electronics, aluminum nitride, thermal conductivity: 100 W / m · K, spherical, average particle size: 6 μm)
FAN-f50 (Furukawa Electronics, aluminum nitride, thermal conductivity: 100 W / m · K, spherical, average particle size: 30 μm)
CB-P05 (made by Showa Denko KK, aluminum oxide, thermal conductivity: 20 W / m · K, spherical, average particle size: 4 μm)
CB-P40 (made by Showa Denko, aluminum oxide, thermal conductivity: 20 W / m · K, spherical, average particle size: 44 μm)
SSC-A15 (manufactured by Shinano Denki Co., Ltd., silicon carbide, thermal conductivity: 100 W / m · K, spherical, average particle size: 19 μm)
SSC-A30 (manufactured by Shinano Denki Co., Ltd., silicon carbide, thermal conductivity: 100 W / m · K, spherical, average particle size: 34 μm)

(C ′) Other inorganic filler HS-306 (manufactured by Micron, silicon oxide, thermal conductivity: 2 W / m · K, spherical, average particle diameter: 2.5 μm)
HS-304 (Micron, silicon oxide, thermal conductivity: 2 W / m · K, spherical, average particle size: 25 μm)

(D) Curing accelerator SA-102 (manufactured by San Apro, DBU octylate)

(X) Ion exchanger (1) Combined use of IXE-100 and IXE-550 (mass ratio 4: 6)
IXE-100 (manufactured by Toagosei Co., Ltd., Zr-based cation exchanger) Median diameter 1.0 μm
IXE-550 (Toagosei Co., Ltd., Bi-based anion exchanger) Median diameter 1.5μm
In addition, these were mix | blended separately, when preparing a curable composition, without mixing previously.
(2) IXEPLAS-B1 (manufactured by Toagosei Co., Ltd., Zr, Bi ion exchanger)
IXEPLAS-B1 is an ion exchanger pulverized mixture obtained by pulverizing an ion exchanger mixture in which a Zr-based cation exchanger and a Bi-based anion exchanger are mixed at a mass ratio of 4: 6. Average primary particle size 400nm

(Other ingredients)
BYK-9076 (manufactured by BYK, dispersant)

(Example 1)
6.5 parts by mass of EX-821 (n = 4), 2.5 parts by mass of jER828, 5 parts by mass of Fujicure 7000, 0.5 parts by mass of SA-102, 42.5 parts by mass of CB-P05, 42.5 parts by mass of CB-P40, 0.1 parts by mass of the ion exchanger in total, and 0.5 parts by mass of BYK-9076 were mixed and defoamed to obtain a curable composition. As the ion exchanger, IXE-100 and IXE-550 were used in combination (mass ratio 4: 6).

(Examples 2 to 17 and Comparative Examples 1 to 4)
A curable composition was obtained in the same manner as in Example 1 except that the types and amounts of the ingredients were changed as shown in Table 1 below. The composition and the results of the following evaluation are shown in Table 1.

(Evaluation)
(1) Measurement of viscosity at 25 ° C. The viscosity (Pa · s) at 10 rpm at 25 ° C. of the curable composition was measured using a B-type viscometer (“TVB-10 type” manufactured by Toki Sangyo Co., Ltd.).

(2) Thermal conductivity The obtained curable composition was heated at 150 ° C. for 2 hours to be cured to obtain a cured product of 100 mm × 100 mm × thickness 50 μm. This cured product was used as an evaluation sample.

The thermal conductivity of the obtained evaluation sample was measured using a thermal conductivity meter “Rapid thermal conductivity meter QTM-500” manufactured by Kyoto Electronics Industry Co., Ltd.

(3) Coating property After the obtained curable composition was directly discharged from a dispenser device ("SHOTMASTER-300" manufactured by Musashi Engineering Co., Ltd.) onto a polyimide film so as to have a diameter of 5 mm and a height of 2 mm, the curable composition Was cured by heating at 150 ° C. for 2 hours. The applicability was determined from the shape of the curable composition after curing according to the following criteria.

[Criteria for applicability]
A: Diameter 5.3 mm or more, height less than 1.8 mm (with fluidity)
B: More than 5 mm in diameter, less than 5.3 mm, more than 1.8 mm in height and less than 2 mm (with little fluidity)
C: 5 mm in diameter and 2 mm in height (no fluidity)

(4) Adhesive strength (die shear strength)
A curable composition was applied on a polyimide substrate so that the adhesion area was 3 mm × 3 mm, and a 3 mm square Si chip was placed thereon to obtain a test sample.

The obtained test sample was heated at 150 ° C. for 2 hours to cure the curable composition. Next, the die shear strength at 25 ° C. was evaluated at a speed of 300 μm / second using a die shear tester “DAGE 4000” (manufactured by Arctech).

[Die shear strength criteria]
A: Die shear strength is 10N or more B: Die shear strength is 6N or more and less than 10N B ': Die shear strength is 5N or more and less than 6N C: Die shear strength is less than 5N

(5) Film warpage The obtained curable composition was directly discharged from a dispenser device ("SHOTMASTER-300" manufactured by Musashi Engineering Co., Ltd.) onto a polyimide film so as to be 20 mm long, 100 mm wide, and 10 mm high, and then cured. The composition was cured by heating at 150 ° C. for 2 hours. After curing, the warpage of the polyimide film was visually confirmed, and the film warpage was determined according to the following criteria.

[Criteria for film warpage]
A: No warpage of polyimide film B: Slight warpage of polyimide film (no problem in use)
C: Warpage of polyimide film (problems in use)

(6) Heat resistance The obtained curable composition was heated at 150 ° C. for 2 hours to be cured to obtain a cured product having a size of 100 mm × 100 mm × thickness 50 μm. This cured product was used as an evaluation sample.

Measurement of volume resistivity of the obtained evaluation sample using a digital super insulation / microammeter “DSM-8104” (manufactured by Hioki Electric Co., Ltd.) and a plate sample electrode “SME-8310” (manufactured by Hioki Electric Co., Ltd.) did.

Next, the sample was allowed to stand at 180 ° C. for 100 hours, and then left at 23 ° C. and a humidity of 50% RH for 24 hours, and then the volume resistivity was measured. The decrease rate of the volume resistivity before and after the heat test was calculated, and the heat resistance was judged according to the following criteria.

[Criteria for heat resistance]
S: The decrease rate of the volume resistivity before and after the test is 5% or less A: The decrease rate of the volume resistivity before and after the test exceeds 5% and 10% or less B: The decrease rate of the volume resistivity before and after the test is 10% Exceeding 20% or less C: Decreasing rate of volume resistivity before and after the test exceeds 20%

(7) Insulation reliability Thermosetting solder on a comb-shaped electrode (material: tin plating on copper, pattern pitch: 50 μm, L / S = 25 μm / 25 μm) formed on a substrate (polyimide film) A resist (“NPR-3300” manufactured by Nippon Polytech Co., Ltd.) was applied to a film thickness of 10 μm and cured by heating at 150 ° C. for 1 hour to prepare a test pattern. A curable composition was applied to the test pattern and cured by heating at 150 ° C. for 2 hours to obtain a test piece. The test piece after heating is put in a bath (“PC-304R9” manufactured by Hirayama Seisakusho Co., Ltd.) having a temperature of 130 ° C. and a humidity of 85%, and a DC voltage of 40 V is applied between the electrodes using a migration tester (“MIG-8600B” manufactured by IMV) Was applied to measure the resistance between the electrodes. Insulation reliability was judged according to the following criteria. In the case of the determination criteria of S, A, or B, the insulation reliability is determined to be acceptable, and there is insulation retention that does not hinder actual use, and the insulation reliability is excellent.

[Criteria for insulation reliability]
S: Resistance is 1 × 10 ⁸ Ω or more and lasts for 144 hours or more, and insulation is very good A: Resistance is 1 × 10 ⁸ Ω or more and lasts for 96 hours or more and less than 144 hours, and insulation is very good B: Resistance is 1 × 10 ⁸ Ω or more and lasts for 48 hours or more and less than 96 hours, insulation is very good C: Resistance is reduced to less than 1 × 10 ⁸ Ω in less than 48 hours, and is regarded as insulation failure

From the results of Examples 1 to 17, it was found that the curable composition of the present invention had good heat dissipation, insulation reliability, and coating properties. On the other hand, from the results of Comparative Examples 3 to 4, the curable composition not using the ion exchanger (X) was inferior in insulation reliability. Moreover, the curable composition of Comparative Example 1 that does not use the specific inorganic filler (C) is inferior in heat dissipation, and the curable composition of Comparative Example 2 that does not use the specific curing agent (B) is in coatability. It was inferior.

DESCRIPTION OF SYMBOLS 11 Semiconductor device 12 Semiconductor element 12a 1st surface 12b 2nd surface 12A 1st electrode 13 Hardened | cured material 14 Connection object member 14a Surface 14A 2nd electrode 15 Other hardened | cured material 16 Conductive particle 17 Protective film

Claims

An epoxy compound (A),
A curing agent (B) which is liquid at 23 ° C .;
An inorganic filler (C) having a thermal conductivity of 10 W / m · K or more and a spherical shape;
An ion exchanger (X),
The curable composition in which the ion exchanger (X) is composed of a zirconium-based cation exchanger and a bismuth-based anion exchanger.
The curable composition according to claim 1, wherein the epoxy compound (A) is a flexible epoxy compound (a1).
The curable composition according to claim 2, wherein the flexible epoxy compound (a1) is a polyalkylene glycol diglycidyl ether having a structural unit in which 9 or more alkylene glycol groups are repeated.
The curable composition according to any one of claims 1 to 3, wherein the curing agent (B) is an allylphenol novolak compound.
The curable composition according to any one of claims 1 to 4, wherein the inorganic filler (C) is at least one selected from the group consisting of alumina, aluminum nitride, and silicon carbide.
A semiconductor element protecting material comprising the curable composition according to any one of claims 1 to 5.
A semiconductor device comprising: a semiconductor element; and a cured product disposed on a first surface of the semiconductor element, wherein the cured product is formed by curing the semiconductor element protecting material according to claim 6. apparatus.
The semiconductor element has a first electrode on a second surface side opposite to the first surface side, and the first electrode of the semiconductor element has a second electrode on the surface thereof The semiconductor device according to claim 7, wherein the semiconductor device is electrically connected to the second electrode.