JP6955329B2 - Curable resin composition, encapsulant and semiconductor device using it - Google Patents

Description

The present invention relates to a curable resin composition, a sealing material using the curable resin composition, and a semiconductor device. More specifically, the present invention relates to a curable resin composition useful as a material for a sealing material for a mounting substrate such as an electronic component or a semiconductor chip, a sealing material using the same, and a semiconductor device.

The curable resin composition is a composition containing a resin having a property of being cured by light or heat, and development of a curable resin composition having the physical properties required for each application is progressing in various industrial fields. One of the uses of such a curable resin composition is a sealing material used for a substrate on which an electronic component, a semiconductor chip, or the like is mounted. When mounting electronic components, semiconductor chips, etc. on a substrate, there are many surface mount methods because high-density mounting is possible, and at that time, they are sealed with a sealing material having electrical insulation. Conventionally, a curable resin composition containing an epoxy resin as an organic main component has been widely used as a sealing material, but when the cured product is left at a high temperature of 200 ° C. or higher for a long time, a machine is used. Since the target strength is lowered, cracks are generated, and peeling from the sealing target is observed, improvement in heat resistance has been eagerly desired.

Therefore, recently, in order to improve the heat resistance, it has been studied to use a cyanate ester compound. The cyanate ester compound is a compound having a cyanato group (-OCN), but it is known that when it is heated, it undergoes an cyclization trimerization reaction to form a triazine ring structure. For example, it is blended in a curable resin composition. In some cases, heat resistance due to the triazine ring structure can be exhibited. For example, Patent Documents 1 to 4 disclose curable resin compositions containing a cyanate ester compound.

Japanese Unexamined Patent Publication No. 2014-15603 Japanese Unexamined Patent Publication No. 2016-156002 JP-A-2015-67759 Japanese Unexamined Patent Publication No. 2003-253125

As described above, it is known that the cyanate ester compound undergoes an alkyne cutter reaction when heated to form a triazine ring. Since high-temperature heating of 250 ° C. or higher is generally required to cause this reaction, a metal catalyst containing cobalt or the like is usually used in combination for the purpose of suppressing foaming. However, even if a metal catalyst is used in combination, the improvement of the curing temperature and the curing rate may be insufficient. For example, encapsulants for semiconductors are often manufactured by pressure molding at around 180 ° C., but under such conditions, the curing speed is slower than that of currently used epoxy resin systems, so epoxy resins can be used. Despite its excellent heat resistance, it is one of the reasons why cyanate ester compounds are not used.

The curable resin compositions described in Patent Documents 1 and 2 have excellent heat resistance and are extremely useful for encapsulant applications. However, they are cured by improving the curing rate and shortening the curing time. There was room for ingenuity to improve the production efficiency of goods. The curable resin composition described in Patent Document 3 cannot exhibit a high level of heat resistance required for a sealing material or the like in recent years, and thus has a problem in this respect. The described insulating resin composition has a slow curing rate, and has a problem in terms of production efficiency of the cured product.

The present invention has been made in view of the above situation, and a curable resin composition which can provide a cured product having excellent heat resistance with high productivity and is particularly useful for encapsulant applications, and a curable resin composition using the same. It is an object of the present invention to provide a sealing material and a semiconductor device.

The present inventors have diligently studied materials useful for encapsulant applications, etc., and when a cyanate ester compound and a silane compound are used in combination, they can be cured even if the curing temperature is lowered, and the obtained cured product has heat resistance. It was found that there was a problem with the curing speed while it was excellent. Therefore, it was found that when the metal complex and the radical generator are used in combination, the curing rate is dramatically improved and the curing time is significantly shortened. In particular, when a metal complex containing an iron atom is used, the curing reaction is accelerated and the curing does not proceed steadily, so that the electrical properties of the obtained cured product become uniform and stable performance is exhibited. be able to. Such a curable resin composition is particularly suitable for use as a sealing material, but a semiconductor device using the curable resin composition is strongly required to have no deterioration in physical properties even in a harsh environment such as high temperature and high pressure and high humidity. We also found that it would be extremely useful for applications such as electrical and electronic parts, automobile parts, and mechanical parts. In this way, he came up with the idea that the above problems could be solved brilliantly, and completed the present invention.

In general, in the use of encapsulants for semiconductors, there is a possibility of causing electrical defects, so it is required that the material does not contain a metal component. The resin composition of the present invention contains a metal complex contrary to the conventional wisdom of the art, but nevertheless, the curing rate is remarkably improved while sufficiently eliminating the possibility of electrical defects. Therefore, it can be said that it is extremely advantageous for encapsulant applications for semiconductors.

That is, the present invention is a curable resin composition containing a cyanate ester compound, a silane compound having a siloxane bond and an imide bond, a metal complex, and a radical generator.

The curable resin composition preferably further contains a maleimide compound.

The above silane compound has the following average composition formula (1):
X _a Y _b Z _c SiO _d (1)
(In the formula, X represents the same or different organic skeleton containing an imide bond. Y represents the same or different at least one selected from the group consisting of a hydrogen atom, a hydroxyl group, a halogen atom and an OR group. R represents at least one group selected from the group consisting of an alkyl group, an acyl group, an aryl group and an unsaturated aliphatic residue, which is the same or different, and may have a substituent. Represents the same or different organic skeleton without imide bonds. A is a non-zero number of 3 or less, b is a number of 0 or less than 3, and c is a number of 0 or less than 3. d is a non-zero number less than 2, and is preferably represented by a + b + c + 2d = 4).

The metal complex preferably contains an iron (Fe) atom.

The present invention is also a sealing material using the curable resin composition.
The present invention is also a semiconductor device using the encapsulant.

Since the curable resin composition of the present invention has the above-mentioned structure, it has sufficient heat resistance, and even after being exposed to a harsh environment, the change over time of various physical properties is sufficiently small and various physical properties are stabilized. The cured product that develops can be provided with high productivity. Therefore, it can be suitably used for encapsulant applications, especially for encapsulant applications such as electronic components and semiconductor chip mounting substrates that require high heat resistance, and semiconductors using such encapsulant materials. The device will be extremely useful in various fields such as electric / electronic, automobile, and mechanical fields.

It is a DSC analysis result of Example 4. It is a DSC analysis result of Comparative Example 3. It is a DSC analysis result of Comparative Example 4. It is the result of the heat cycle test performed in Example 5.

Hereinafter, preferred embodiments of the present invention will be specifically described, but the present invention is not limited to the following description, and can be appropriately modified and applied without changing the gist of the present invention. A form in which two or three or more of the individual preferred forms of the present invention described below are combined is also a preferred form of the present invention.

1. Curable Resin Composition The curable resin composition of the present invention (hereinafter, also simply referred to as “resin composition”) contains a cyanate ester compound, a silane compound, a metal complex, and a radical generator. Further, other components may be contained, and each contained component may be used alone or in combination of two or more.

(1) Cyanate Ester Compound The cyanate ester compound used in the present invention may be a compound having at least two cyanate groups (-OCN) in one molecule, and is represented by, for example, the following formula (a). Compounds are preferred.

In the formula, R ¹ and R ² represent the same or different hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl halide group, or a halogen group (X). R ³ represents any of the same or different organic groups represented by the following chemical formulas. R ⁴ represents an organic group represented by the following chemical formula, which is the same or different. m is 0 or 1. p represents an integer from 0 to 10.

The compound represented by the above formula (a) is not particularly limited, but for example, bis (4-cyanatophenyl) methane, bis (3,5-dimethyl-4-cyanatophenyl) methane, bis (3-methyl). -4-Cyanatophenyl) Methan, Bis (4-Cyanatophenyl) -1,1-Etan, Bis (4-Cyanatophenyl) -2,2-Etan, 2,2-Bis (4-Cyanatophenyl) ) Propane, 2,2-bis (3,5-dimethyl-4-cyanatophenyl) methane, di (4-cyanatophenyl) ether, di (4-cyanatophenyl) thioether, 4,4- {1, 3-Phenylene bis (1-methylethylidene)} bisphenyl cyanato, 4,4-disianatophenyl, 2,2-bis (4-cyanatophenyl) -1,1,1,3,3,3-hexa Fluoropropane, 1,1'-bis- (p-cyanatophenyl) -ethane, 2,2'-bis (p-cyanatophenyl) propane, 4,4'-methylenebis (2,6-dimethylphenyl cyanato) ), 2,2'-Bis (p-Cyanatophenyl) Hexafluoropropane, α, α'-Bis (4-Cyanatophenyl) -m-diisopropylbenzene and other dihydric phenolic cyanate esters; Tris (4) -Cyanate ester of trivalent phenols such as phenyl) -1,1,1-ethane, bis (3,5-dimethyl-4-cyanatephenyl) -4-cyanatephenyl-1,1,1-ethane; phenol Examples thereof include novolak-type cyanate ester, cresol novolak-type cyanate ester, dicyclopentadienbisphenol-type cyanate ester; and the like. Among these, 2,2-bis (4-cyanatophenyl) propane and phenol novolac-type cyanate esters are preferable from the viewpoint of the dielectric properties and curability of the cured product.

As the cyanate ester compound, a multimer (for example, a trimer or a pentamer) formed by cyclizing the cyanate group of the compound represented by the above formula (a) to form a triazine ring structure is used. You can also do it. Of these, trimers are preferable from the viewpoint of operability and solubility in other curable resins. The method for obtaining the multimer may be an ordinary method.

The cyanate ester compound may be in a liquid state or a solid state, but in consideration of melt-kneading with other curable resins, the cyanate ester compound has high compatibility, or has a melting point or softening point of 120 ° C. or lower. It is preferable that the compound has. More preferably, it has a melting point or a softening point of 100 ° C. or lower.

Here, the melting point means the temperature (° C.) in which the crystals melt and become liquid in an inert atmosphere. Therefore, amorphous compounds and those that are already liquid at room temperature do not have a melting point. The melting point of the cyanate ester compound can be measured by, for example, differential scanning calorimetry (DSC). The softening point (° C.) is a value measured according to JIS K7234 (1986), and is measured using, for example, a thermal softening temperature measuring device (product name "ASP-MG4", manufactured by Meitec Corporation). Can be done.

(2) Silane Compound The silane compound (also referred to as a siloxane compound) used in the present invention includes a siloxane bond and an imide bond. That is, one molecule contains at least one siloxane bond (Si—O—Si bond) and at least one imide bond. By including such a silane compound, the curable resin composition becomes particularly excellent in heat resistance and the like.

In the above silane compound, the structure of the siloxane skeleton (main chain skeleton that requires a siloxane bond) is preferably chain-like (linear or branched), ladder-like, net-like, cyclic, cage-like, cubic-like, or the like. Illustrated. Of these, a ladder-like, net-like, or cage-like shape is preferable because the effect is likely to be exhibited even if the amount of the silane compound added is small. That is, the silane compound containing polysilsesquioxane is particularly preferable.

The proportion of the siloxane skeleton in the silane compound is preferably 10 to 80% by mass based on 100% by mass of the silane compound. It is more preferably 15 to 70% by mass, and even more preferably 20 to 50% by mass.

The proportion of the organic skeleton having an imide bond in the silane compound is preferably 20 to 100 mol with respect to 100 mol of silicon atoms (Si) contained in the silane compound. This makes it possible to more fully exert the effects of the present invention. It is more preferably 50 to 100 mol, still more preferably 70 to 100 mol.

Among the above silane compounds, an organic residue having an imide bond and an oxygen atom are bonded to a silicon atom (Si) to form a siloxane skeleton (main chain skeleton indispensable for a siloxane bond) via the oxygen atom. A compound having a structure is preferable. That is, an organic skeleton having one or more imide bonds, one or more oxygen atoms (O), and in some cases other skeletons are bonded to a silicon atom (Si), and the organic skeleton having an imide bond and oxygen A form in which the total number of bonds between the atom and the other skeleton is four is preferable. In such a form, the number of bonds of the organic skeleton having an imide bond bonded to the silicon atom is preferably 1 to 3, preferably 1 to 2, and more preferably 1. The number of oxygen atoms (oxygen atoms bonded to the silicon atom to which the organic skeleton having an imide bond is bonded) is preferably 1 to 3, preferably 2 to 3, and more preferably 3. The number of bonds of the other organic skeleton is preferably 0 to 2, preferably 0 to 1, and more preferably 0. As a preferable combination (number of bonds) of the skeleton (group) bonded to the silicon atom, (organic skeleton having an imide bond, oxygen atom, other skeleton) is (1, 3, 0), (2, 2, 0). ), (1, 2, 1), (3, 1, 0), (2, 1, 1), (1, 1, 2).

When the preferable form of the silane compound is represented by an average composition formula, the following average composition formula (1):
XaYbZcSiOd (1)
(In the formula, X represents the same or different organic skeleton containing an imide bond. Y represents at least one selected from the group consisting of hydrogen atom, hydroxyl group, halogen atom and OR group, which is the same or different. R represents at least one group selected from the group consisting of an alkyl group, an acyl group, an aryl group and an unsaturated aliphatic residue, which is the same or different, and may have a substituent. Represents the same or different organic skeleton without imide bonds. A is a non-zero number of 3 or less, b is a number of 0 or less than 3, and c is a number of 0 or less than 3. d is a non-zero number less than 2, and can be represented by a + b + c + 2d = 4), and the form in which the silane compound is represented by the average composition formula (1) is one of the preferred forms of the present invention. Is. As a result, heat resistance and the like are further improved.

In the above average composition formula (1), a preferable form of X is as described later. The coefficient a of X is a number of 3 or less that is not 0, but is preferably a number less than 3.

Y is preferably a hydroxyl group or an OR group. Of these, an OR group is more preferable, and a OR group in which R is an alkyl group having 1 to 8 carbon atoms is more preferable.

Z is preferably at least one selected from the group consisting of an alkyl group, an aromatic residue (aryl group, aralkyl group, etc.), and an unsaturated aliphatic residue. These may have substituents. More preferably, it is an alkyl group having 1 to 8 carbon atoms or an aromatic residue (aryl group, aralkyl group, etc.) which may have a substituent. Specifically, for example, methyl group, ethyl group, phenyl group, vinyl group, chloropropyl group, mercaptopropyl group, (epoxycyclohexyl) ethyl group, glycidoxypropyl group, N-phenyl-3-aminopropyl group, (Meta) Acryloxypropyl group, hexyl group, decyl group, octadecyl group, trifluoropropyl group and the like are suitable.

The silane compound can be represented by, for example, the following formula (2).

In the formula, X, Y and Z are the same as above. n ₁ and n ₂ indicate the degree of polymerization. n ₁ is a non-zero positive integer and n ₂ is 0 or a positive integer.
Here, "Y / Z-" indicates that Y or Z is bonded, and "X _1-2- " indicates that one or two Xs are bonded, and "(Z). / Y) _1-2- "indicates that one Z or Y is combined, two Z or Y are combined, or one Z and one Y are combined, for a total of two. "Si- (X / Y / Z) ₃ " indicates that any three types selected from X, Y and Z are bonded to the silicon atom.

In the above formula (2), Si-Om ₁ and Si-Om ₂ is not intended to define the binding order of Si-Om ₁ and Si-Om _2, for example, Si-Om ₁ and Si-Om ₂ alternating Alternatively, a form in which co-condensation is randomly performed, a form in _{which a polysiloxane composed of Si—Om 1} and a polysiloxane of Si—Om ₂ are bonded, and the like are preferable, and the condensation structure is arbitrary.

The siloxane skeleton (main chain skeleton that requires a siloxane bond) contained in the silane compound can also be expressed as _{(SiO m} ) _n. In the present invention, it is preferable to use the compound represented by the above average composition formula (1) as the silane compound, but in the compound, _{the structure other than (SiO m} ) _n is an organic skeleton having an imide bond (imide bond). Essential structure) X, Y such as hydrogen atom and hydroxyl group, and organic group Z containing no imide bond, and these are bonded to the silicon atom (Si) of the main chain skeleton.

X, Y and Z may or may not be included in the repeating unit in the form of a "chain". For example, X may be contained in one molecule as a side chain at least one. In the above (SiO _m ) _n , n represents the degree of polymerization, and the degree of polymerization represents the degree of polymerization of the main chain skeleton, and n organic skeletons having imide bonds do not necessarily have to exist. In other words, it is not necessary that an organic skeleton having one imide bond always exists in one unit of _{(SiO m} ) _n. Further, one or more organic skeletons having an imide bond may be contained in one molecule, but when a plurality of organic skeletons are contained, as described above, an organic skeleton having two or more imide bonds in one silicon atom may be contained. It may be combined. These are also the same in the following.

In the main clavicle (SiO _m ) _n , m is preferably a number of 1 or more and less than 2. More preferably, m = 1.5 to 1.8. n represents the degree of polymerization and is preferably 1 to 5000. It is more preferably 1 to 2000, still more preferably 1 to 1000, and particularly preferably 1 to 200. For example, the silane compound when n = 2 is a structural unit in which at least one organic skeleton (X) having an imide bond is bonded to a silicon atom (Si) (hereinafter, also referred to as “constituent unit (I)”). A form containing two (referred to as) and a form containing only one structural unit (I) can be mentioned. Specifically, the form represented by the following formula (3) is preferable, and a homopolymer form containing two identical structural units (I) and a homopolymer containing two different structural units (I) are preferable. There is a form of the copolymer (a form of a co-condensation structure) containing only one structural unit (I).

In the formula, A is Y or Z, and X, Y and Z are the same as described above.

In the above average composition formula (1), X is preferably a structural unit represented by the following formula (4). That is, in the present invention, it is preferable to use at least a compound in which X in the average composition formula (1) is a structural unit represented by the following formula (4) as the silane compound. By using a silane compound containing a ring structure in the structure in this way, the heat resistance of the cured product is further improved.

In the formula, R ⁵ represents at least one structure selected from the group consisting of aromatics, heterocycles and alicyclics. x and z are the same or different integers of 0 or more and 5 or less, and y is 0 or 1. x + z may be an integer of 0 or more and 10 or less, but is preferably 3 to 7, more preferably 3 to 5, and even more preferably 3. y is preferably 0.

In the above formula (4), R ⁵ represents at least one structure selected from the group consisting of aromatics, heterocycles and alicyclics. That is, a group R ⁵ has a ring structure of the aromatic compound (an aromatic ring), a group having a ring structure (heterocycle) heterocyclic compounds, and a group having the ring structure of the alicyclic compound (alicyclic) Indicates that it is at least one group selected from the group consisting of. Specific examples R ^5, a phenylene group, naphthylidene group, divalent group of norbornene, (alkyl) cyclohexylene group, cyclohexenyl group and the like.
Here, the structural unit represented by the above formula (4) is a structural unit represented by the following ^{formula (4-1) when R 5} is a phenylene group, and R ⁵ is a (alkyl) cyclohexylene group. In the case of, it becomes a structural unit represented by the following formula (4-2), and when R ⁵ is a naphthylidene group, it becomes a structural unit represented by the following formula (4-3), and R ⁵ is a norbornene. When it is a divalent group, it is a structural unit represented by the following formula (4-4), and when R ⁵ is a cyclohexenyl group, it is a structural unit represented by the following formula (4-5).

In formulas (4-1) to (4-5), x, y and z are the same as the symbols in the above formula (4).
In the above formula (4-1), R ^{6 to} R ⁹ represent at least one structure selected from the group consisting of a hydrogen atom, an alkyl group, a halogen atom and an aromatic, which are the same or different. R ^{6 to} R ⁹ are preferably in the form of all hydrogen atoms.
In the above formula (4-2), R ^{10 to} R ¹³ and R ^10'to R ^13'are the same or different, and are at least one selected from the group consisting of a hydrogen atom, an alkyl group, a halogen atom and an aromatic. Represents the structure. The R ¹⁰ to R ¹³ and ^R 10' ^{to R 13',} forms all ^{R 11} or ^{R 12} are the remaining methyl group is a hydrogen ^atom, R 10 ^{to R 13} and all ^R 10' ^{to R 13'} Is preferably a hydrogen atom or a form in which ^{all of R 10 to} R ¹³ and R ^10'to R ^13'are fluorine atoms. More preferably, R ¹¹ or R ¹² is a methyl group and all the rest are hydrogen atoms.

In the above formula (4-3), R ^{14 to} R ¹⁹ represent at least one structure selected from the group consisting of a hydrogen atom, an alkyl group, a halogen atom and an aromatic, which are the same or different. As R ^{14 to} R ¹⁹ , a form in which all are hydrogen atoms or a form in which all are fluorine atoms is preferable. More preferably, it is in the form of all hydrogen atoms.
The formula (4-4) ^in, R 20 ^{to R 25} are the same or different, represents at least one structure hydrogen atom, an alkyl group, selected from the group consisting of a halogen atom and an aromatic. As R ^{20 to} R ²⁵ , any form of all hydrogen atoms, all fluorine atoms, or all chlorine atoms is preferable. More preferably, it is in the form of all hydrogen atoms.

In the above formula (4-5), R ^{26 to} R ²⁹ , R ^26'and R ^29'are the same or different, and at least one selected from the group consisting of a hydrogen atom, an alkyl group, a halogen atom and an aromatic. Represents the structure. The R ^{26 to} R ²⁹ , R ^26'and R ^29'are preferably in any form of all hydrogen atoms, all fluorine atoms, or all chlorine atoms. More preferably, it is in the form of all hydrogen atoms.

Among the above formulas (4-1) to (4-5), the formula (4-4) or (4-5) is preferable. When a silane compound having a reactive carbon-carbon unsaturated bond is used in such a side chain, the appearance of the cured product is improved.

A particularly preferable form of the silane compound is a form in which x = z = 1 and y = 0 in the above formula (4). Among them, R ⁵ is a phenylene group poly (.gamma. phthaloyl imide propyl silsesquioxane); R ⁵ is a methyl cyclohexylene poly {.gamma. (to Kisahidoro-4-methyl phthalimide) propyl silsesquioxane} ; ^{R 5} is naphthylidene group poly {.gamma. (1,8-naphthalimide) propyl silsesquioxane}; poly ^{R 5} is divalent norbornene {.gamma. (5-norbornene-2,3 imide) propyl silsesquioxane}; poly ^{R 5} is a cyclohexenyl group [(cis-4-cyclohexene-1,2-imido) propyl silsesquioxane]; being most preferred.
The structures of these compounds ^{can be identified by measuring 1 1} H-NMR, ¹³ C-NMR, and MALDI-TOF-MS.

The molecular weight of the silane compound is preferably 100 to 10,000 on a number average molecular weight. If the polymer compound exceeds 10,000, it may not be able to be mixed more sufficiently with the cyanate ester compound. On the other hand, if it is less than 100, the heat resistance and the like may not be sufficient. It is more preferably 500 to 5000, still more preferably 1000 to 5000. The weight average molecular weight is preferably 100 to 10,000. It is more preferably 500 to 5000, still more preferably 1000 to 5000.

In the present specification, the molecular weight (number average molecular weight and weight average molecular weight) of the silane compound can be determined by gel permeation chromatography (GPC) measurement under the following conditions.
<Measurement conditions>
Measuring equipment: HLC-8120GPC (trade name, manufactured by Tosoh Corporation)
Column: TSK-GEL GMHXL-L and TSK-GELG5000HXL (both manufactured by Tosoh Corporation) are connected in series and used. Eluent: tetrahydrofuran (THF)
Standard material for calibration curve: Polystyrene (manufactured by Tosoh)
Measurement method: The object to be measured is dissolved in THF so that the solid content is about 0.2% by mass, and the molecular weight is measured using the material filtered through a filter as a measurement sample.

The method for obtaining the silane compound is not particularly limited, and examples thereof include the following production methods (I) and (II).
(I) an organic skeleton X'having an amide bond that corresponds to the organic backbone X, the average composition formula having a siloxane bond _X'a Y _b Z _c intermediates consisting of silane compound represented by SiO _d, imide A manufacturing method including a step of converting.
(II) A production method comprising a step of hydrolyzing and condensing an intermediate composed of a silane compound in which an organic skeleton having an imide bond corresponding to the organic skeleton X is bonded to a silicon atom and has a hydrolyzable group.

In the curable resin composition of the present invention, the mass ratio of the cyanate ester compound and the silane compound (cyanate ester compound / silane compound) is preferably 50 to 90/10 to 50 (mass%). Within this range, precipitation of the silane compound during curing can be further prevented, and the curing promoting effect of the cyanate ester compound by the silane compound can be more exerted. More preferably, it is 55 to 80/20 to 45.

(3) Metal Complex The curable resin composition of the present invention essentially contains a metal complex.
A metal complex is a complex of a metal and a ligand, but in the present invention, a metal complex containing at least one of iron, copper, zinc, cobalt, nickel, manganese, tin, aluminum and the like is used. Suitable. Among them, those containing iron, copper and / or zinc are preferable, and those containing iron are more preferable. By using such a metal complex containing at least an iron atom, it is possible to further solve the problems of curing temperature and curing rate, which are concerns when a cyanate ester compound is used, and the effects of the present invention are more remarkablely exhibited. NS.

The ligand that gives the metal complex is not particularly limited, but for example, acetylacetone, 3,5-heptandione, 1,1,1-trifluoro-2,4-pentandione, 1,1,1,5,5. Β-diketones such as 5-hexafluoro-2,4-pentandion; β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, n-propyl acetoacetone, isopropyl acetoacetate; dimethyl malonate, diethyl malonate, etc. Malonate diesters; β-ketoamides such as acetoacetoanilide; carboxylic acids such as acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanic acid, octanoic acid and 2-ethylhexanoic acid; and the like. Of these, β-diketone or carboxylic acid is preferable.

The content of the metal complex is preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of the cyanate ester compound. This makes it possible to more fully exert the effects of the present invention. It is more preferably 0.01 to 1 part by mass, and further preferably 0.05 to 0.5 part by mass.

(4) Radical Generator The radical generator used in the present invention is not particularly limited, and examples thereof include a thermal radical generator and a photoradical generator.
As the thermal radical generator, a thermal radical polymerization initiator is preferable. For example, t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butylperoxyisopropyl carbonate, t-butylperoxy-2. Organic peroxides such as -ethylhexanoate, 1,3-bis (t-butylperoxyisopropyl) benzene, t-butylperoxybenzoate; 2,2'-azobisisobutyronitrile, 2,2' -Azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropion amidine) ) Disulfate, 2,2'-azobis (N, N'-dimethyleneisobutyramidine), 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropion amidine] hydrate, 1, Azo compounds such as 1'-azobis (cyclohexanecarbonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate); hydrogen peroxide, etc. Peroxides such as potassium persulfate and ammonium persulfate; 2,3-dimethyl-2,3-diphenylbutane; and the like.

As the photoradical generator, a photoradical polymerization initiator is preferable. The photoradical polymerization initiator is a compound that generates radicals that can initiate polymerization by exposure to radiation such as visible light, ultraviolet rays, far ultraviolet rays, electron beams, and X-rays. For example, thioxanthone compounds, acetophenone compounds, biimidazole compounds, triazine compounds, O-acyloxime compounds, onium salt compounds, benzoin compounds, benzophenone compounds, α-diketone compounds, polynuclear quinone compounds, Examples thereof include diazo compounds and imide sulfonate compounds.

Among the radical generators described above, it is preferable to use at least a thermal radical polymerization initiator. More preferably, it is an organic peroxide and / or 2,3-dimethyl-2,3-diphenylbutane.

From the viewpoint of further shortening the curing time, it is preferable to use a compound having a half-life of 1 minute and a temperature of 150 to 300 ° C. as the radical generator. Of these, compounds having a half-life of 1 minute and a temperature of 160 to 290 ° C. are particularly preferable.

The content of the radical generator is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the cyanate ester compound. This makes it possible to more fully exert the effects of the present invention. It is more preferably 0.05 to 5 parts by mass, still more preferably 0.1 to 4 parts by mass.

(5) Maleimide Compound The curable resin composition of the present invention preferably further contains a maleimide compound. By containing the maleimide compound, the handleability of the resin composition is improved.
Examples of the maleimide compound include bismaleimide, for example, N, N'-ethylene bismaleimide, N, N'-hexamethylene bismaleimide, N, N'-m-phenylene bismaleimide, N, N'-p-phenylene bismaleimide. , 2,2-bis [4- (4-maleimidephenoxy) phenyl] propane, bis [4- (4-maleimidephenoxy) phenyl] methane, 1,1,1,3,3,3-hexafluoro-2, 2-Bis [4- (4-maleimidephenoxy) phenyl] propane, N, N'-p, p'-diphenyldimethylsilyl bismaleimide, N, N'-4,4'-diphenyl ether bismaleimide, N, N' -Methylenebis (3-chloro-p-phenylene) bismaleimide, N, N'-4,4'-diphenylsulfone bismaleimide, N, N'-4,4'-dicyclohexylmethanebismaleimide, N, N'-di Methylenecyclohexanebismaleimide, N, N'-m-xylenebismaleimide, N, N'-4,4'-diphenylcyclohexanebismalimide, N-phenylmaleimide and aldehyde compounds such as formaldehyde, acetaldehyde, benzaldehyde, hydroxyphenylaldehyde The cocondensate of is suitable.

The maleimide compound also has the following formula (5):

(In the formula, R ³⁰ is the following formula:

Represents a divalent group represented by. Q ¹ represents a group directly linked to two aromatic rings, a divalent hydrocarbon group having 1 to 10 carbon atoms, 6 fluorinated isopropylidene group, a carbonyl group, thio group, sulfinyl group, sulfonyl group and oxides Represents at least one group selected from the group consisting of groups. ) Is preferable.

Specifically, as the above-mentioned bismaleimide compound, for example, 1,3-bis (3-maleimidephenoxy) benzene, bis [4- (3-maleimidephenoxy) phenyl] methane, 1,1-bis [4- (3- (3-) Maleimide phenoxy) phenyl] ethane, 1,2- [4- (3-maleimide phenoxy) phenyl] ethane, 2,2-bis [4- (3-maleimide phenoxy) phenyl] propane, 2,2-bis [4- (3-Maleimidephenoxy) phenyl] butane, 2,2-bis [4- (3-maleimidephenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 4,4-bis (3) -Maleimidephenoxy) biphenyl, bis [4- (3-maleimidephenoxy) phenyl] ketone, bis [4- (3-maleimidephenoxy) phenyl] sulfide, bis [4- (3-maleimidephenoxy) phenyl] sulfoxide, bis [ 4- (3-Maleimidephenoxy) phenyl] sulfone, bis [4- (3-maleimidephenoxy) phenyl] ether, or the following formula (6):

(In the formula, Q ² represents a divalent group consisting of an aromatic ring which may have a substituent. N ³ represents the number of repetitions, which is a number of 0 to 10 on average.). Compounds and the like are suitable. Q ² is, specifically, a phenyl group, a biphenyl group, a divalent group such as a naphthyl group (a phenylene group, biphenylene group, naphthylidene group) are preferable.

When the maleimide compound is a polymer compound, the weight average molecular weight of the maleimide compound is preferably 200 to 5000. When the molecular weight of the maleimide compound is in such a range, a more excellent cured product can be obtained due to heat resistance and the like. It is more preferably 220 to 4500, and even more preferably 250 to 4000.
In the present specification, the weight average molecular weight of the maleimide compound can be determined by GPC under the same measurement conditions as the molecular weight of the above-mentioned silane compound.

When the resin composition contains a maleimide compound, the content of the maleimide compound is preferably 5 to 120 parts by mass with respect to 100 parts by mass of the cyanate ester compound. When used in such a ratio, the heat resistance and handleability of the resin composition are further improved. It is more preferably 5 to 100 parts by mass, still more preferably 5 to 90 parts by mass.

(6) Filler The curable resin composition of the present invention preferably further contains a filler. As the filler, an inorganic filler is preferable, and a filler used as a sealing material for a normal mounting substrate or the like may be used. For example, silica filler (for example, molten silica) and the like can be mentioned.

The content ratio of the filler is preferably 50 to 95% by mass with respect to 100% by mass of the total amount of the curable resin composition. It is more preferably 60 to 93% by mass, still more preferably 70 to 90% by mass. By using such a large amount of inorganic filler, for example, when it is used to obtain a sealing material for a mounting substrate, it is possible to sufficiently prevent warpage of the substrate after curing.

(7) Other components The curable resin composition of the present invention may also contain other components other than the above-mentioned components, if necessary. For example, volatile components such as organic solvents and diluents; flame retardants; reinforcing materials; coupling agents; stress relaxation agents; mold release agents; stabilizers; colorants; plasticizers; flexible agents; various rubber-like substances; light Photosensitizers; pigments; etc. may be mentioned, and one or more of these may be used.

As long as the curable resin composition of the present invention essentially contains a cyanate ester compound, a silane compound, a metal complex, and a radical generator, the production method thereof is not particularly limited, and these components and, if necessary, are not particularly limited. It can be obtained by mixing arbitrary components contained in the above by a usual method. For example, after obtaining a cyanate ester-based composition by the above-mentioned method for producing a cyanate ester-based composition, other components to be blended as necessary are added simultaneously or sequentially, and each component is appropriately added using a mixer or the like. It can be obtained by kneading with a kneader, a roll, a single-screw extrusion kneader, a twin-screw extrusion kneader, or the like after mixing so that the esters are uniformly dispersed. In addition, the silane compound, the cyanate ester compound, and other components to be blended as necessary are added simultaneously or sequentially, and appropriately mixed using a mixer or the like so that each component is uniformly dispersed. It can be obtained by kneading using a roll, a single-screw extrusion kneader, a twin-screw extrusion kneader, or the like.
In the mixing and kneading steps, heating or cooling may be performed as needed.

Although the curable resin composition depends on the molding (molding) method, the viscosity at 150 ° C. is preferably 0.01 to 60 Pa · s when transfer molding or the like is performed. When the resin composition has such an appropriate viscosity, for example, it becomes excellent in handleability at the time of coating. More preferably, it is 0.02 to 40 Pa · s. When casting at room temperature, it is liquid at room temperature, preferably 5 to 1000 Pa · s. This is because if the viscosity is too low, the inorganic filler may settle, and if the viscosity is too high, the unevenness to be sealed may not be filled. More preferably, it is 10 to 500 Pa · s. The preferable range of the viscosity of the curable resin composition at 175 ° C. is the same as the preferable range of the viscosity at 150 ° C. described above.
In the present specification, the viscosity of the resin composition can be measured using, for example, an E-type viscometer (manufactured by Brookfield) or a flow tester CFT-500D (manufactured by Shimadzu Corporation).

2. Cured product The curable resin composition of the present invention can be made into a cured product by, for example, heat curing. The curing method is not particularly limited, and a normal thermosetting method may be adopted. For example, the thermosetting temperature is preferably 70 to 280 ° C, more preferably 100 to 250 ° C. The curing time is preferably 0.5 to 5 hours, more preferably 1 to 3 hours. In the present invention, since the curing reaction proceeds sufficiently even in such a short time, it can greatly contribute to the improvement of the productivity of the cured product.

The shape of the cured product is not particularly limited, and examples thereof include molded products such as deformed products, films, sheets, and pellets. As described above, a cured product made by using the curable resin composition of the present invention (also referred to as “cured product of the curable resin composition of the present invention”) is also one of the preferable forms of the present invention.

The cured product preferably has a glass transition temperature of 180 ° C. or higher by a thermomechanical analyzer (DMA). Thereby, for example, it can be more preferably used as an electronics mounting material such as a sealing material for a mounting substrate. It is more preferably 190 ° C. or higher, further preferably 195 ° C. or higher, and particularly preferably 200 ° C. or higher.

Since the cured product is obtained from the curable resin composition of the present invention, the glass transition temperature is remarkably high and the mechanical strength is extremely excellent. Therefore, for example, mounting applications, optical applications, etc. It is useful for various applications such as opt device applications, display device applications, mechanical parts applications, electrical / electronic parts applications, automobile parts applications, and printing ink applications. Specifically, for example, it is preferably used for electronics mounting materials such as encapsulants, potting materials, underfill materials, conductive pastes, insulating pastes, die pond materials, printing inks and the like. Above all, it is more preferably used as an electronics mounting material, and in particular, it is extremely useful as a sealing material for a mounting substrate. As described above, the encapsulant made of the curable resin composition (also referred to as the encapsulant containing the curable resin composition and may be the encapsulant made of the curable resin composition) is also used. , Is one of the present invention. A semiconductor encapsulant is particularly preferable as the encapsulant. Further, a semiconductor device or a printed wiring board made of the cured product is also included in a preferred embodiment of the present invention. A semiconductor device using the sealing material (also referred to as a semiconductor device including a sealing layer containing the sealing material or a semiconductor device including a sealing layer which is a cured product of the sealing material). , Is one of the present inventions. As a semiconductor device, it can be suitably applied to a device using a power device (for example, a SiC power device or the like), which has been attracting attention in recent years.

The encapsulant is, for example, a member used when encapsulating a semiconductor component, but is required, for example, a curing accelerator, a stabilizer, and a mold release agent, as long as the effect of the present invention is not impaired. It can contain agents, coupling agents, colorants, plasticizers, flexible agents, various rubber-like substances, photosensitizers, fillers, flame retardants, pigments and the like. Further, since the encapsulant may cause a problem if it contains a large amount of volatile components, it is desired that the encapsulant does not contain volatile components. For example, 100% by mass of the encapsulant contains volatile components. The amount is preferably 10% by mass or less. It is more preferably 5% by mass or less, further preferably 3% by mass or less, and particularly preferably substantially free of volatile components.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "parts" means "parts by mass (or parts by weight)" and "%" means "% by mass (or% by weight)". The method for measuring and evaluating the molecular weight and gelation time is as follows.

1. Molecular weight measurement The number average molecular weight and weight average molecular weight of the siloxane compound were determined by GPC (gel permeation chromatography) measurement under the following measurement conditions.
Measuring equipment: HLC-8120GPC (manufactured by Tosoh)
Molecular weight column: TSK-GEL GMHXL-L and TSK-GELG5000HXL (both manufactured by Tosoh Corporation) are connected in series for use.
Eluent: tetrahydrofuran (THF)
Standard material for calibration curve: Polystyrene (manufactured by Tosoh)
Measurement method: The object to be measured is dissolved in THF so that the solid content is about 0.2% by mass, and the molecular weight is measured using the material filtered through a filter as a measurement sample.

2. Gelling time The time when the viscosity reached the upper limit and did not change was determined as the "gelling time" by the flow tester measurement.
Measuring equipment: CFT-500D (manufactured by Shimadzu Corporation)
Measurement conditions: temperature 180 ° C, sample volume 2.7 g

3. Evaluation of electrical characteristics 1) Preparation of semiconductor package A TO247 type package was produced by insert molding of a copper lead frame using a low-voltage transfer molding machine. The molding conditions were set to a mold temperature of 180 ° C., a clamp pressure of 294 KN, a preheat time of 5 seconds, an injection pressure of 15 KN, an injection speed of 0.9 mm / s, a transfer time of 18 seconds, and a curing time of 360 seconds. The obtained semiconductor package was heated in an inert oven (nitrogen atmosphere, temperature 270 ° C.) for 5 hours to perform post-cure.
2) Heat cycle test A heat cycle test was carried out using a thermal shock device TSA-71S (manufactured by ESPEC). The test conditions were a cooling temperature of −50 ° C., a heating temperature of 250 ° C., and a holding time of 30 minutes.
3) Characteristic evaluation Using the power device analyzer B1505A (manufactured by Agilent Technologies), the IV characteristic evaluation (electrical characteristic) of the prepared semiconductor package was performed.

Synthesis example 1
87.9 g of jigglime pre-dried with molecular sieve in a 500 mL four-necked flask equipped with a synthetic stirrer for poly {γ- (5-norbornen-2,3-imide) propylsilsesquioxane}, a temperature sensor, and a cooling tube. Then, 142.5 g of 3-aminopropyltrimethoxysilane was added, and the temperature was raised to 100 ° C. under the flow of dry nitrogen with stirring to remove the water content in the system. Next, 131.8 g of 5-norbornene-2,3-dicarboxylic acid anhydride was added in 4 portions over 30 minutes while maintaining the reaction solution temperature at 100 ° C. It was confirmed by high-speed liquid chromatography that 5-norbornene-2,3-dicarboxylic acid anhydride was completely consumed 9 hours after the completion of the charging. Subsequently, 42.9 g of deionized water was added all at once, the temperature was raised so that the by-product methanol was refluxed in the cooling tube, and the temperature was maintained at 95 ° C. for 10 hours. Then, the reaction solution temperature was brought to 120 ° C. over 3 hours while recovering the by-product methanol and condensed water. When it reaches 120 ° C, 0.65 g of cesium carbonate is added and the temperature rise is started as it is. Product A was obtained.
The reaction product A was a dark brown high-viscosity liquid with a non-volatile content of 70.0%, and when the molecular weight was measured by GPC, the number average molecular weight was 2340 and the weight average molecular weight was 2570.
^{1 1} H-NMR and ¹³ C-NMR were measured, and it was confirmed that the compound of the following formula (I) (siloxane compound 1) was contained.
^{1 1} H-NMR: 0.25-0.45 (bs, 2H), 1.2-1.45 (bs, 2H), 1.47 (dd, 2H), 3.0-3.2 (bs, 4H), 3.4-3.6 (bs, 2H), 5.8-6.0 (bs, 2H)
¹³ C-NMR: 9.7, 21.5, 40.4, 44.9, 45.7, 50.1, 134.2, 178.0

Examples 1 to 3, Comparative Examples 1 and 2
The raw materials were mixed according to the composition shown in Table 1, and then kneaded with a heating roll kneader to obtain a compound. At this time, the roll temperature was set to 80 ° C., and the kneading time was set to 6 minutes. The obtained compound was crushed by a crusher. The gelation time was measured using the obtained powder.
The numerical values of the composition in Table 1 below represent parts by weight.

Details of the compounds in Table 1 are as follows. The chemical formulas of the radical generators 1 to 3 are shown in Table 2.
Cyanate ester compound: Primasset PT-30 (manufactured by Lonza Japan)
Maleimide compound: BMI-80 (manufactured by KAI Kasei Co., Ltd.)
Radical generator 1: Parkadox 14 (manufactured by Kayaku Akzo, 1,3-bis (t-butylperoxyisopropyl) benzene)
Radical generator 2: Kayabutyl B (manufactured by Kayaku Akzo, t-butyl peroxybenzoate)
Radical generator 3: Novmer BC90 (manufactured by NOF Corporation, 2,3-dimethyl-2,3-diphenylbutane)
Fused Silica: Denka Fused Silica (DF) (manufactured by Denka)
Flame Retardant: Z-10 (manufactured by Tateho Chemical Industries, Ltd.)
Carbon black: MA600 (manufactured by Mitsubishi Chemical Corporation)
Phenol formaldehyde: TD-2131 (manufactured by DIC Corporation)

As shown in Table 1, the metal complex and the radical generator are compared with the case where only one of the metal complex and the radical generator is contained together with the cyanate ester compound and the silane compound (siloxane compound) (Comparative Examples 1 and 2). When used in combination with (Examples 1 to 3), it was confirmed that the gelation time was shortened. From this, it was found that the combined use of the metal complex and the radical generator dramatically improves the curing rate and significantly shortens the curing time.

Example 4
0.3 parts of cyanate ester compound, 0.3 parts of maleimide compound, 0.3 parts of siloxane compound 1, 0.002 parts of iron (III) acetylacetonate, 0 parts of radical generator 1 (Percadox 14) .02 parts were mixed, and 4 ml of methylene chloride was added and dissolved. The solution was dried under reduced pressure on an aluminum cup. The obtained solid was analyzed by DSC. The analysis result is shown in FIG.

Comparative Example 3
A solid was obtained in the same manner except that the radical generator 1 (Percadox 14) was removed from the composition of Example 4. The DSC analysis result of the obtained solid is shown in FIG.

Comparative Example 4
A solid was obtained in the same manner except that iron (III) acetylacetonate was removed from the composition of Example 4. The DSC analysis result of the obtained solid is shown in FIG.

From FIGS. 1 to 3, compared with the case where the metal complex and the radical generator are used in combination with the cyanate ester compound and the silane compound (siloxane compound) (Example 4), only one of them is added (Comparative Example). In 3 and 4), the DSC curve was broad, and an exothermic peak could be confirmed even at 200 ° C. or higher. Therefore, it can be inferred that the temperature required for the curing reaction is lower when the metal complex and the radical generator are used in combination, and the peak shape is sharp, so that the curing time is shortened.

Example 5
Using the powder obtained in Example 2 as a sealing material, a semiconductor package was produced by the above-mentioned method. A heat cycle test was carried out for 300 cycles with the obtained package, and the IV characteristics were evaluated before and after that. The result is shown in FIG.
Generally, when the sealing resin or the semiconductor chip is deteriorated by the heat cycle test, a leak current may occur or the yield voltage may change. Further, if a substance that can be a source of ionic impurities such as a metal complex or a radical generator is present, a problem is likely to occur. However, as shown in FIG. 4, since the IV characteristics did not change before and after the heat cycle, it can be said that the material functions as a sealing material.

Claims (5)

It contains a cyanate ester compound, a silane compound having a siloxane bond and an imide bond, a metal complex, and a radical generator.
The silane compound has the following average composition formula (1):
X _a Y _b Z _c SiO _d (1)
(In the formula, X represents the same or different organic skeleton containing an imide bond. Y represents the same or different at least one selected from the group consisting of a hydrogen atom, a hydroxyl group, a halogen atom and an OR group. R represents at least one group selected from the group consisting of an alkyl group, an acyl group, an aryl group and an unsaturated aliphatic residue, which is the same or different, and may have a substituent. Represents the same or different organic skeleton without imide bonds. A is a non-zero number of 3 or less, b is a number of 0 or less than 3, and c is a number of 0 or less than 3. d is a non-zero number less than 2 and is represented by a + b + c + 2d = 4).
The metal complex contains iron, copper, and / or zinc as metal atoms.
The radical generator is a curable resin composition characterized by being an organic peroxide. The curable resin composition according to claim 1, further comprising a maleimide compound. The curable resin composition according to claim 1 or 2 , wherein the metal complex contains an iron (Fe) atom. A sealing material using the curable resin composition according to any one of claims 1 to 3. A semiconductor device using the sealing material according to claim 4.

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