JP7562201B2 - Hot melt curable silicone composition, sealant, film, optical semiconductor element - Google Patents

Description

The present invention relates to a curable silicone composition, and more specifically, to a curable silicone composition used to seal, cover, or adhere an optical semiconductor element. The present invention also relates to a sealant made of such a curable silicone composition, and an optical semiconductor element containing this sealant. The present invention also relates to a film formed by solidifying the curable silicone composition.

Curable silicone compositions are used in a wide range of industrial fields because they cure to form cured products with excellent heat resistance, cold resistance, electrical insulation, weather resistance, water resistance, and transparency. In particular, the cured products are less susceptible to discoloration than other organic materials, and the deterioration of physical properties is minimal, making them suitable for use as optical materials.

For example, Patent Documents 1 to 3 describe resin compositions for sealing optical semiconductor elements or for optical lenses, which use a curable silicone resin composition containing an organopolysiloxane having two or more non-covalent double bond groups in one molecule, an organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms in one molecule, and a catalytic amount of a platinum-based catalyst. Patent Documents 4 and 5 also describe hot-melt silicone resin compositions that are non-flowable at 25°C, have low surface adhesion, and melt easily when heated.

JP 2006-299099 A JP 2007-246894 A JP 2006-324596 A JP 2013-001794 A International Publication No. 2015/194158

However, when hot melt films are made from conventional silicone resin compositions, there is a problem that the mechanical properties of the film, particularly film strength and elongation, are insufficient. For example, when used to form film- or sheet-like sealants and lamination films in the manufacture of semiconductor packages, the resulting films tend to tear easily and are therefore insufficient in terms of workability.

The object of the present invention is to provide a hot-melt curable silicone composition that exhibits excellent mechanical properties, particularly strength and elongation, even when molded into a film or sheet shape. More specifically, the object of the present invention is to provide a hot-melt curable silicone composition that can be used to form a sheet- or film-like sealant and a lamination film that are easy to handle and can be used to efficiently manufacture semiconductor packages.

In order to solve the above problems, the present inventors have conducted extensive research and have come to the conclusion that
(A) an organopolysiloxane having at least two alkenyl groups in one molecule;
(B) 0.1 to 5 mass %, based on the total mass of the composition, of a resin-like organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in each molecule;
(C) Average unit formula (C-1):
(R ¹ ₃ SiO _1/2 ) _a (R ¹ ₂ SiO _2/2 ) _b (R ¹ SiO _3/2 ) _c
(In the formula, R ^1s are the same or different and are alkyl groups, aryl groups, alkenyl groups, aralkyl groups, or epoxy group-containing organic groups, with the proviso that at least one R ¹ is an alkenyl group and at least one R ¹ is an epoxy group-containing organic group, and a, b, and c are numbers that satisfy 0≦a≦1.0, 0≦b≦1.0, 0≦c<0.9, and a+b+c=1.)
The present inventors have discovered that the above problems can be solved by a solventless hot-melt curable silicone composition containing additives (D) a hydrosilylation reaction catalyst represented by the formula: and (E) silica, and have arrived at the present invention.

In one embodiment of the present invention, component (A) comprises a resinous organopolysiloxane containing at least one (Ar ₂ SiO _2/2 ) unit.

In one embodiment of the present invention, the component (B) is represented by the average unit formula (B-1):
(R ³ ₃ SiO _1/2 ) _a (R ³ ₂ SiO _2/2 ) _b (R ³ SiO _3/2 ) _c (SiO _4/2 ) _d (XO _1/2 ) _e
(wherein ^R3 is a hydrogen atom or the same or different halogen-substituted or unsubstituted monovalent hydrocarbon groups, with the proviso that at least two ^R3 are hydrogen atoms, X is a hydrogen atom or an alkyl group, and a, b, c, d, and e are numbers that satisfy 0≦a≦1.0, 0≦b≦1.0, 0≦c<0.9, 0≦d<0.5, 0≦e<0.4, a+b+c+d=1.0, and c+d>0.)

In the above average unit formula (B-1), a may be in the range of 0.1≦a≦0.9, b may be in the range of 0≦b≦0.8, c may be in the range of 0.1≦c≦0.9, d may be in the range of 0≦d≦0.4, and e may be in the range of 0≦e≦0.3.

In the above average unit formula (C-1), a may be in the range of 0≦a≦0.9, b may be in the range of 0.1≦b≦0.9, and c may be in the range of 0.01≦c≦0.8.

The content of alkenyl groups in component (C) may be 5 mol % or more of the total of ^R1 .

The content of the epoxy group-containing organic group in component (C) may be 5 mol % or more of the total of ^R1 .

In one embodiment of the present invention, component (A) includes linear, branched, and cyclic organopolysiloxanes.

The present invention also relates to a film obtained by solidifying the hot-melt curable silicone composition of the present invention.

The present invention also relates to a sealant comprising the hot-melt curable silicone composition of the present invention.

The present invention also relates to an optical semiconductor element containing the encapsulant of the present invention.

The semiconductor element of the present invention is preferably a light-emitting diode.

The hot-melt curable silicone composition of the present invention can exhibit excellent mechanical properties, particularly strength and elongation, even when molded into a film or sheet shape. Therefore, the hot-melt curable silicone composition of the present invention can be used to form sheet- or film-like sealants and lamination films that are easy to handle and can be used to efficiently manufacture semiconductor packages.

In addition, the sealant of the present invention is formed from the hot-melt curable silicone composition of the present invention, and therefore exhibits excellent mechanical properties, particularly strength and elongation, resulting in excellent handling and workability. This allows for efficient production of semiconductor packages.

The present invention will be described in detail below.

[Hot-melt curable silicone composition]
The present invention relates to a solventless hot-melt curable silicone composition,
(A) an organopolysiloxane having at least two alkenyl groups in one molecule;
(B) 0.1 to 5 mass %, based on the total mass of the composition, of a resin-like organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in each molecule;
(C) Average unit formula (C-1):
(R ¹ ₃ SiO _1/2 ) _a (R ¹ ₂ SiO _2/2 ) _b (R ¹ SiO _3/2 ) _c
(In the formula, R ^1s are the same or different and are alkyl groups, aryl groups, alkenyl groups, aralkyl groups, or epoxy group-containing organic groups, with the proviso that at least one R ¹ is an alkenyl group and at least one R ¹ is an epoxy group-containing organic group, and a, b, and c are numbers that satisfy 0≦a≦1.0, 0≦b≦1.0, 0≦c<0.9, and a+b+c=1.)
and (E) silica.

The silicone composition of the present invention does not contain a solvent, and exhibits hot melt properties when molded into a film shape, sheet shape, or the like by heat treatment. In this specification, "hot melt properties" refers to a property that is non-fluid at 25°C, but easily melts and exhibits fluidity when heated. For example, the hot melt silicone composition of the present invention has a melt modulus of elasticity at 100°C in the range of 10 Pa to 1 MPa. Here, non-fluidity means that it does not flow under no load, and indicates a state below the softening point measured by the ring and ball method for the softening point test method of hot melt adhesives specified in JIS K 6863-1994 "Softening Point Test Method for Hot Melt Adhesives". In other words, the hot melt silicone composition of the present invention preferably has a softening point higher than 25°C. The melt modulus of elasticity at 100°C can be measured by a flat plate type viscoelasticity measuring instrument capable of controlling the temperature. In addition, the silicone composition of the present invention is a hot melt curable silicone composition that has both hot melt properties and curability.

The hot-melt curable silicone composition of the present invention can exhibit excellent mechanical properties, particularly strength and elongation, even when molded into a film or sheet shape. Therefore, the hot-melt curable silicone composition of the present invention can be used to form a sealant and lamination film for manufacturing semiconductor packages that are easy to handle and can efficiently manufacture semiconductor packages.

Each ingredient is explained in detail below.

(A) Alkenyl-Containing Organopolysiloxane Component (A) is the main component of the curable silicone composition of the present invention, and is an alkenyl-containing organopolysiloxane that contains at least two silicon-bonded alkenyl groups per molecule.

Examples of the alkenyl group contained in component (A) include alkenyl groups having 2 to 12 carbon atoms, such as vinyl groups, allyl groups, butenyl groups, pentenyl groups, hexenyl groups, heptenyl groups, octenyl groups, nonenyl groups, decenyl groups, undecenyl groups, and dodecenyl groups, with vinyl groups being preferred.

Examples of the molecular structure of component (A) include linear, partially branched linear, branched, cyclic, and three-dimensional network structures. Component (A) may be one organopolysiloxane having these molecular structures, or a mixture of two or more organopolysiloxanes having these molecular structures. The curable silicone composition of the present invention preferably contains both a linear organopolysiloxane and a branched resin-like organopolysiloxane as component (A).

In one embodiment of the present invention, the component (A) is
(A-1) Average unit formula: R ² ₃ SiO(R ² ₂ SiO) _m SiR ² ₃
(wherein R ² is the same or different, a halogen-substituted or unsubstituted monovalent hydrocarbon group, with the proviso that in one molecule, at least two R ² are alkenyl groups, and m is an integer of 4 to 1,000), and/or
(A-2) Average unit formula: (R ² ₃ SiO _1/2 ) _a (R ² ₂ SiO _2/2 ) _b (R ² SiO _3/2 ) _c (SiO _4/2 ) _d (XO _1/2 ) _e
(wherein ^R2 is the same as defined above, with the proviso that in one molecule, at least two ^R2 's are alkenyl groups, X is a hydrogen atom or an alkyl group, and a, b, c, d, and e are numbers that satisfy 0≦a≦1.0, 0≦b≦1.0, 0≦c<0.9, 0≦d<0.5, 0≦e<0.4, a+b+c+d+e=1.0, and c+d>0), and/or
(A-3) Average unit formula: (R ² SiO _2/2 ) _n
(wherein R ² is the same as defined above, with the proviso that at least two R ² in one molecule are alkenyl groups, and n is an integer of 3 to 50).

Preferably, the hot melt curable silicone composition of the present invention contains both linear and branched organopolysiloxanes as component (A).More preferably, the hot melt curable silicone composition of the present invention contains linear, branched and cyclic organopolysiloxanes as component (A).Note that the branched organopolysiloxane refers to a resin-like organopolysiloxane, and refers to an organopolysiloxane that contains at least one T unit or Q unit in one molecule among the siloxane units (M units) represented by the general formula: _{R3SiO1 / 2} , the siloxane units (D units) represented by the general formula: R2SiO2/ ₂ , the siloxane units (T units) represented by the general formula: RSiO3 _/2 and the siloxane units (Q units) represented by the formula: SiO4 _/2 .

Examples of the halogen-substituted or unsubstituted monovalent hydrocarbon group for ^R2 in the above formula include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; alkyl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl groups; aryl groups, aralkyl groups having 7 to 20 carbon atoms such as benzyl, phenethyl, and phenylpropyl groups, alkenyl groups having 2 to 12 carbon atoms such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl groups, and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as fluorine, chlorine, and bromine atoms. ^R2 may also be a small amount of hydroxyl groups or alkoxy groups such as methoxy and ethoxy groups, within the scope of the present invention.

^R2 is preferably selected from a phenyl group, an alkyl or cycloalkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms.

The content of alkenyl groups in component (A) is not particularly limited, but it is preferable that alkenyl groups account for 0.01 to 50 mol %, 0.05 to 40 mol %, or 0.09 to 32 mol % of the total of R ^2. The content of alkenyl groups can be determined, for example, by analysis using a Fourier transform infrared spectrophotometer (FT-IR), nuclear magnetic resonance (NMR), or the like.

Component (A) preferably comprises a resinous organopolysiloxane containing at least one (Ar ₂ SiO _2/2 ) unit.

The resin-like organopolysiloxane containing at least one ( _{Ar2SiO2 /2} ) unit as component (A) of the present invention preferably has a ratio of T units in the molecular structure of 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more. In a preferred embodiment, the resin-like organopolysiloxane of the present invention has a ratio of T units in the molecular structure of 0.9 or less, preferably 0.85 or less, and even more preferably 0.8 or less. In another preferred embodiment, the resin-like organopolysiloxane of the present invention has a ratio of Q units in the molecular structure of 0.2 or less, preferably 0.1 or less, and even more preferably does not contain Q units. The proportions of the T units and Q units can be calculated based on the amounts of siloxane units (M units) represented by the general formula: _R3SiO1 / ₂ , siloxane units (D units) represented by the general formula: _R2SiO2 / ₂ , siloxane units (T units) represented by the general formula: RSiO3 _/2 , and siloxane units (Q units) represented by the formula: SiO4 _/2 in the resinous organopolysiloxane.

In the (Ar ₂ SiO _2/2 ) unit, Ar represents an aryl group. The aryl group may be unsubstituted or substituted, and is preferably an aryl group having 6 to 20 carbon atoms, such as a phenyl group, a tolyl group, a xylyl group, a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, and groups in which the hydrogen atoms of these aryl groups are substituted with alkyl groups such as a methyl group or an ethyl group; alkoxy groups such as a methoxy group or an ethoxy group; or halogen atoms such as a chlorine atom or a bromine atom. The aryl group is particularly preferably a phenyl group.

The resinous organopolysiloxane of the present invention as component (A) preferably has a ratio of ( _{Ar2SiO2 /} 2) units in its molecular structure of 0.05 or more, more preferably 0.1 or more, even more preferably 0.15 or more, and preferentially 0.2 or more. In a preferred embodiment, the resinous organopolysiloxane of the present invention has a ratio of ( _{Ar2SiO2 /2} ) units in its molecular structure of 0.5 or less, preferably 0.45 or less, and more preferably 0.4 or less.

In the resinous organopolysiloxane as component (A) containing at least one ( _{Ar2SiO2 /2} ) unit, preferably 40 mol % or more of the monovalent hydrocarbon groups bonded to silicon atoms are aryl groups, more preferably 50 mol % or more, and especially 60 mol % or more of the monovalent hydrocarbon groups bonded to silicon atoms are aryl groups.

The resinous organopolysiloxane of component (A) can preferably be represented by the following average unit formula (A-4):
(A-4) (R ² ₃ SiO _1/2 ) _a (R ² ₂ SiO _2/2 ) _b (Ar ₂ SiO _2/2 ) _b' (R ² SiO _3/2 ) _c (SiO _4/2 ) _d (XO _1/2 ) _e
(In the formula, ^R2 and Ar are the same as above, with the proviso that in one molecule, at least two ^R2 's are alkenyl groups, X is a hydrogen atom or an alkyl group, ^R22SiO2 _/2 represents a unit other than _{Ar2SiO2 /2} , and a, b, b', c, d, and e are numbers that satisfy 0≦a≦1.0, 0 _≦ b≦1.0, 0<b'≦1.0, 0≦c<0.9, 0≦d<0.5, 0≦e<0.4, a+b+b'+c+d=1.0, and c+d>0.)

In the average unit formula (A-4), a is preferably in the range of 0≦a≦0.5, more preferably in the range of 0≦a≦0.3, and preferentially in the range of 0≦a≦0.2, and in particular in the range of 0≦a≦0.1. In the average unit formula (A-4), b is preferably in the range of 0≦b≦0.8, more preferably in the range of 0.1≦b≦0.7, and in particular in the range of 0.15≦b≦0.6. In the average unit formula (A-4), b' is preferably in the range of 0.1≦b'≦0.7, more preferably in the range of 0.2≦b'≦0.6, and in particular in the range of 0.25≦b'≦0.5. In the average unit formula (A-4), c is preferably in the range of 0.1≦c≦0.9, more preferably in the range of 0.2≦c≦0.85, and in particular in the range of 0.3≦c≦0.8. In the average unit formula (A-4), d is preferably in the range of 0≦d≦0.4, more preferably in the range of 0≦d≦0.3, and particularly in the range of 0≦d≦0.2. In the average unit formula (A-4), e is preferably in the range of 0≦e≦0.3, more preferably in the range of 0≦e≦0.2, and particularly in the range of 0≦e≦0.1.

The curable silicone composition of the present invention preferably contains, as component (A), a resinous organopolysiloxane containing at least one ( _{Ar2SiO2 /2} ) unit in an amount of 10 mass% or more, preferably 20 mass% or more, more preferably 30 mass% or more, and even more preferably 40 mass% or more, based on the total mass of the composition. In a preferred embodiment, the curable silicone composition of the present invention contains, based on the total mass of the composition, 90 mass% or less, preferably 80 mass% or less, and more preferably 70 mass% or less of the resinous organopolysiloxane containing at least one ( _{Ar2SiO2 /2} ) unit.

The (A) component is preferably contained in an amount of 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, and preferentially 60% by mass or more, based on the total mass of the composition of the present invention, and is preferably contained in an amount of 90% by mass or less, more preferably 85% by mass or less, and particularly preferably 80% by mass or less.

(B) Resin-like organohydrogenpolysiloxane The resin-like organohydrogenpolysiloxane (i.e., branched-chain organohydrogenpolysiloxane) having at least two silicon-bonded hydrogen atoms in one molecule of the component (B) acts as a crosslinking agent for the hydrosilylation reaction curable curable silicone composition.Preferably, the component (B) is a resin-like organohydrogenpolysiloxane containing silicon-bonded hydrogen atoms at least at both ends of the molecular chain.The component (B) may be a single organopolysiloxane, or may be a combination of two or more organopolysiloxanes.

The silicon-bonded hydrogen atoms of component (B) are preferably contained at least at both ends of the molecular chain, and may also be contained in side chains of the molecular chain, or may only be contained at both ends of the molecular chain. Examples of groups bonded to silicon atoms other than hydrogen atoms in component (B) include alkyl groups having 1 to 12 carbon atoms, such as methyl groups, ethyl groups, propyl groups, isopropyl groups, butyl groups, isobutyl groups, tert-butyl groups, pentyl groups, neopentyl groups, hexyl groups, cyclohexyl groups, heptyl groups, octyl groups, nonyl groups, decyl groups, undecyl groups, and dodecyl groups; aryl groups having 6 to 20 carbon atoms, such as phenyl groups, tolyl groups, xylyl groups, and naphthyl groups; aralkyl groups having 7 to 20 carbon atoms, such as benzyl groups, phenethyl groups, and phenylpropyl groups; and groups in which some or all of the hydrogen atoms of these groups are replaced with halogen atoms, such as fluorine atoms, chlorine atoms, and bromine atoms. The silicon atoms in component (B) may contain small amounts of hydroxyl groups or alkoxy groups such as methoxy and ethoxy groups, as long as the purpose of the present invention is not impaired.

In one embodiment of the present invention, (B-1) an average unit formula:
(R ³ ₃ SiO _1/2 ) _a (R ³ ₂ SiO _2/2 ) _b (R ³ SiO _3/2 ) _c (SiO _4/2 ) _d (XO _1/2 ) _e
(wherein ^R3 is a hydrogen atom or the same or different halogen-substituted or unsubstituted monovalent hydrocarbon groups, with the proviso that at least two ^R3 's are hydrogen atoms, X is a hydrogen atom or an alkyl group, and a, b, c, d, and e are numbers that satisfy 0≦a≦1.0, 0≦b≦1.0, 0≦c<0.9, 0≦d<0.5, 0≦e<0.4, a+b+c+d=1.0, and c+d>0).

Examples of the halogen-substituted or unsubstituted monovalent hydrocarbon group for R ³ in the above formula B-1 include alkyl groups having 1 to 12 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a cyclohexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, or a dodecyl group; and alkyl groups having 6 to 20 carbon atoms, such as a phenyl group, a tolyl group, a xylyl group, or a naphthyl group. aryl groups, aralkyl groups having 7 to 20 carbon atoms such as benzyl, phenethyl, and phenylpropyl groups, alkenyl groups having 2 to 12 carbon atoms such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl groups, and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as fluorine, chlorine, and bromine atoms. ^R3 may also be a small amount of hydroxyl groups or alkoxy groups such as methoxy and ethoxy groups, within the scope of the present invention.

In the above formula B-1, a is preferably in the range of 0.1≦a≦0.9, more preferably in the range of 0.2≦a≦0.8, and particularly in the range of 0.4≦a≦0.7. In the above formula B-1, b is preferably in the range of 0≦b≦0.8, more preferably in the range of 0≦b≦0.5, and particularly in the range of 0≦b≦0.2. In the above formula B-1, c is preferably in the range of 0.1≦c≦0.9, more preferably in the range of 0.2≦c≦0.7, and particularly in the range of 0.3≦c≦0.5. In the above formula B-1, d is preferably in the range of 0≦d≦0.4, more preferably in the range of 0≦d≦0.3, and particularly in the range of 0≦d≦0.2. In the above formula B-1, e is preferably in the range of 0≦e≦0.3, more preferably in the range of 0≦e≦0.2, and particularly in the range of 0≦e≦0.1.

The (B-1) component is contained in the hot-melt curable silicone composition of the present invention in an amount of 0.1 to 5 mass % based on the total mass of the composition of the present invention. The (B) component is preferably contained in the hot-melt curable silicone composition of the present invention in an amount of 0.5 mass % or more, more preferably 1 mass % or more, based on the total mass of the composition of the present invention, for example, in an amount of 4.5 mass % or less.

In one embodiment of the present invention, component (B) is preferably present in an amount such that there are 0.001 to 5 moles, more preferably 0.01 to 2 moles, and particularly preferably 0.05 to 1 mole of silicon-bonded hydrogen atoms per mole of silicon-bonded alkenyl groups in component (A).

In addition to the above-mentioned component (B), the hot-melt curable silicone composition may contain, as component (B'), an organohydrogenpolysiloxane that acts as a crosslinking agent for the hydrosilylation reaction-curable curable silicone composition. Such component (B') is preferably a linear organohydrogenpolysiloxane. As component (B'), only one type of organopolysiloxane may be used, or two or more types of organopolysiloxanes may be used in combination.

The silicon-bonded hydrogen atoms of component (B') are preferably contained at least at both ends of the molecular chain, and may also be contained in side chains of the molecular chain, or may only be contained at both ends of the molecular chain. Examples of groups bonded to silicon atoms other than hydrogen atoms in component (B) include alkyl groups having 1 to 12 carbon atoms, such as methyl groups, ethyl groups, propyl groups, isopropyl groups, butyl groups, isobutyl groups, tert-butyl groups, pentyl groups, neopentyl groups, hexyl groups, cyclohexyl groups, heptyl groups, octyl groups, nonyl groups, decyl groups, undecyl groups, and dodecyl groups; aryl groups having 6 to 20 carbon atoms, such as phenyl groups, tolyl groups, xylyl groups, and naphthyl groups; aralkyl groups having 7 to 20 carbon atoms, such as benzyl groups, phenethyl groups, and phenylpropyl groups; and groups in which some or all of the hydrogen atoms of these groups are replaced with halogen atoms, such as fluorine atoms, chlorine atoms, and bromine atoms. The silicon atoms in component (B') may contain small amounts of hydroxyl groups or alkoxy groups such as methoxy and ethoxy groups, as long as the purpose of the present invention is not impaired.

In one embodiment of the present invention, the component (B') is represented by the average composition formula (B-2):
(R ³ ₃ SiO _1/2 ) _a (R ³ ₂ SiO _2/2 ) _b (XO _1/2 ) _e
(wherein ^R3 and X are the same as above, and a, b, and e are numbers satisfying 0≦a≦1.0, 0≦b≦1.0, 0≦e<0.4, and a+b=1.0).

In one embodiment of the present invention, the (B') component may be represented by the following structural formula:
[HR ⁴ ₂ SiO _1/2 ] ₂ [R ⁴ ₂ SiO _2/2 ] _y
In the formula, R ⁴ is the same or different halogen-substituted or unsubstituted monovalent hydrocarbon group, and y is a number ranging from 1 to 100, preferably from 1 to 10. As the halogen-substituted or unsubstituted monovalent hydrocarbon group for R ⁴ , the same ones as those described for R ³ can be applied.

The (B') component is preferably contained in the hot-melt curable silicone composition of the present invention in an amount of 1 mass % or more, more preferably 5 mass % or more, preferentially 10 mass % or more, and especially 15 mass % or more, based on the total mass of the composition of the present invention, and may be contained in the hot-melt curable silicone composition of the present invention in an amount of preferably 50 mass % or less, more preferably 40 mass % or less, and especially 30 mass % or less.

The total content of components (B) and (B') is preferably such that the number of silicon-bonded hydrogen atoms in this component is 0.1 to 10 moles per mole of silicon-bonded alkenyl groups in component (A), more preferably 0.5 to 5 moles, and particularly 0.5 to 1.5 moles. The total content of components (B) and (B') is preferably 1 mass% or more, more preferably 5 mass% or more, preferentially 10 mass% or more, and particularly 15 mass% or more, based on the total mass of the composition of the present invention, and is preferably 50 mass% or less, more preferably 40 mass% or less, and particularly 30 mass% or less.

(C) Additive The additive which is the component (C) of the present invention has the average unit formula (C-1):
(R ¹ ₃ SiO _1/2 ) _a (R ¹ ₂ SiO _2/2 ) _b (R ¹ SiO _3/2 ) _c
(In the formula, R ¹ 's are the same or different and are an alkyl group, an aryl group, an alkenyl group, an aralkyl group, an epoxy group-containing organic group, or an alkoxy group, with the proviso that at least one R ¹ is an alkenyl group and at least one R ¹ is an epoxy group-containing organic group, and a, b, and c are numbers that satisfy 0≦a≦1.0, 0≦b≦1.0, 0≦c<0.9, and a+b+c=1.)
That is, component (C) contains at least one alkenyl group bonded to a silicon atom and at least one epoxy group-containing organic group.

In this specification, examples of "epoxy group-containing groups" include glycidoxyalkyl groups such as 2-glycidoxyethyl, 3-glycidoxypropyl, and 4-glycidoxybutyl groups; epoxycycloalkylalkyl groups such as 2-(3,4-epoxycyclohexyl)-ethyl and 3-(3,4-epoxycyclohexyl)-propyl groups; and epoxyalkyl groups such as 3,4-epoxybutyl and 7,8-epoxyoctyl groups, with glycidoxyalkyl groups being preferred and 3-glycidoxypropyl being particularly preferred.

In this specification, the term "alkoxy group" refers to, for example, a methoxy group, an ethoxy group, a butoxy group, a phenoxy group, a pentyloxy group, an allyloxy group, a cyclohexyloxy group, a benzyloxy group, a naphthyloxy group, an acetoxy group, etc., and is preferably a methoxy group or an ethoxy group, and particularly preferably a methoxy group.

Examples of the alkenyl group contained in component (C) include alkenyl groups having 2 to 12 carbon atoms, such as vinyl groups, allyl groups, butenyl groups, pentenyl groups, hexenyl groups, heptenyl groups, octenyl groups, nonenyl groups, decenyl groups, undecenyl groups, and dodecenyl groups, with vinyl groups being preferred.

R ¹ in the above formula C-1 is preferably selected from an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. Specifically, R ¹ in the above formula C-1 is preferably an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, or a dodecyl group; an alkenyl group such as a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, a nonenyl group, a decenyl group, an undecenyl group, or a dodecenyl group; a phenyl group, a tolyl group, a xylyl group, a naphthyl group, an anthracenyl group, or a phenanthryl group. , pyrenyl group, and other aryl groups; naphthylethyl group, naphthylpropyl group, anthracenylethyl group, phenanthrylethyl group, pyrenylethyl group, and other aralkyl groups; and groups in which some or all of the hydrogen atoms of these aryl groups or aralkyl groups have been substituted with alkyl groups such as methyl group, ethyl group, and other alkoxy groups such as methoxy group, ethoxy group, and other halogen atoms such as chlorine atom, bromine atom, and more preferably, methyl group, vinyl group, and phenyl group.

In the above formula C-1, a is preferably in the range of 0≦a≦0.9, more preferably in the range of 0≦a≦0.5, and particularly in the range of 0≦a≦0.3. In the above formula C-1, b is preferably in the range of 0.1≦b≦0.9, more preferably in the range of 0.2≦b≦0.8, and particularly in the range of 0.25≦b≦0.7. In the above formula C-1, c is preferably in the range of 0.01≦c≦0.8, more preferably in the range of 0.1≦c≦0.7, and particularly in the range of 0.2≦c≦0.6.

The content of alkenyl groups in component (C) is not particularly limited, but is, for example, 1 mol % or more, preferably 5 mol % or more, more preferably 8 mol % or more, and for example, 40 mol % or less, preferably 30 mol % or less, more preferably 30 mol % or less, of the total of ^R 1. The content of alkenyl groups can be determined, for example, by analysis using a Fourier transform infrared spectrophotometer (FT-IR), nuclear magnetic resonance (NMR), or the like.

The content of the epoxy group-containing organic group in component (C) is not particularly limited, but is, for example, ¹ mol % or more, preferably 5 mol % or more, more preferably 10 mol % or more, and for example, 50 mol % or less, preferably 40 mol % or less, more preferably 35 mol % or less, of the total of R 1. The content of the epoxy group-containing organic group can be determined, for example, by analysis using a Fourier transform infrared spectrophotometer (FT-IR), nuclear magnetic resonance (NMR), or the like.

The (C) component is preferably contained in the hot-melt curable silicone composition of the present invention in an amount of 0.01 mass% or more, more preferably 0.1 mass% or more, preferentially 0.3 mass% or more, and particularly 0.5 mass% or more, based on the total mass of the composition of the present invention, and is preferably contained in the hot-melt curable silicone composition of the present invention in an amount of 20 mass% or less, more preferably 15 mass% or less, and preferentially 10 mass% or less.

(D) Hydrosilylation Catalyst The hydrosilylation catalyst of component (D) is a catalyst for accelerating the curing of the hot-melt curable silicone composition of the present invention. Examples of this component (D) include platinum-based catalysts such as chloroplatinic acid, an alcohol solution of chloroplatinic acid, a complex of platinum and an olefin, a complex of platinum and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, and a powder carrying platinum; palladium-based catalysts such as tetrakis(triphenylphosphine)palladium, palladium black, and a mixture with triphenylphosphine; and rhodium-based catalysts, with platinum-based catalysts being particularly preferred.

The amount of component (D) is a catalytic amount. When a platinum catalyst is used as component (D), the amount of platinum metal contained in this platinum catalyst is preferably in the range of 0.01 to 1000 ppm by weight in the hot-melt curable silicone composition of the present invention, and more preferably in the range of 0.1 to 500 ppm.

(E) Silica Examples of the silica of component (E) include fumed silica, wet silica, crystalline silica, precipitated silica, etc. In addition, the silica may be surface-hydrophobized with an organosilicon compound such as an organoalkoxysilane compound, an organochlorosilane compound, an organosilazane compound, or a low-molecular-weight siloxane compound, or a silane coupling agent, a titanate coupling agent, or the like.

The amount of component (E) contained in the hot-melt curable silicone composition of the present invention is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, preferentially 0.5% by mass or more, and particularly 1% by mass or more, based on the total mass of the composition of the present invention, and is preferably 20% by mass or less, more preferably 15% by mass or less, and preferentially 10% by mass or less.

The hot-melt curable silicone composition of the present invention may contain optional components within the scope of the present invention. Examples of optional components include acetylene compounds, organic phosphorus compounds, vinyl group-containing siloxane compounds, hydrosilylation reaction inhibitors, inorganic fillers other than (E) silica such as crushed quartz, titanium oxide, magnesium carbonate, zinc oxide, iron oxide, and diatomaceous earth (also referred to as "inorganic fillers"); inorganic fillers obtained by subjecting the surface of such inorganic fillers to hydrophobic treatment with an organic silicon compound; organopolysiloxanes that do not contain silicon-bonded hydrogen atoms and silicon-bonded alkenyl groups; adhesive agents, heat resistance agents, cold resistance agents, thermally conductive fillers, flame retardant agents, thixotropic agents, fluorescent materials, pigments such as carbon black, and coloring components such as dyes; and solvents.

The hydrosilylation reaction inhibitor is a component for inhibiting the hydrosilylation reaction of the silicone composition. Specific examples include acetylene-based inhibitors such as 1-ethynyl-2-cyclohexanol, amine-based inhibitors, carboxylate-based inhibitors, and phosphite-based inhibitors. The amount of reaction inhibitor added is usually 0.001 to 5% by mass of the entire silicone composition.

(E) Examples of inorganic fillers other than silica include inorganic fillers such as hollow fillers, silsesquioxane, fumed titanium dioxide, magnesium oxide, zinc oxide, iron oxide, aluminum hydroxide, magnesium carbonate, calcium carbonate, zinc carbonate, layered mica, diatomaceous earth, and glass fibers; and fillers obtained by subjecting these fillers to a surface hydrophobic treatment with an organosilicon compound such as an organoalkoxysilane compound, an organochlorosilane compound, an organosilazane compound, or a low molecular weight siloxane compound. Silicone rubber powder, silicone resin powder, and the like may also be blended. However, the amount of inorganic filler blended is preferably 20% by mass or less, and particularly 10% by mass or less, of the silicone composition.

Examples of phosphors include yellow, red, green, and blue light-emitting phosphors made of oxide-based phosphors, oxynitride-based phosphors, nitride-based phosphors, sulfide-based phosphors, oxysulfide-based phosphors, fluoride-based phosphors, and the like, which are widely used in light-emitting diodes (LEDs), and mixtures of at least two of these. Examples of oxide-based phosphors include yttrium, aluminum, and garnet-based YAG-based green to yellow light-emitting phosphors containing cerium ions, terbium, aluminum, and garnet-based TAG-based yellow light-emitting phosphors containing cerium ions, and silicate-based green to yellow light-emitting phosphors containing cerium and europium ions. Examples of oxynitride-based phosphors include silicon, aluminum, oxygen, and nitrogen-based sialon-based red to green light-emitting phosphors containing europium ions. Examples of nitride-based phosphors include calcium, strontium, aluminum, silicon, and nitrogen-based Cazn-based red light-emitting phosphors containing europium ions. Examples of sulfide phosphors include ZnS-based green-emitting phosphors containing copper ions or aluminum ions. Examples of oxysulfide phosphors include _{Y2O2S -} based red-emitting phosphors containing europium ions. Examples of fluoride phosphors include KSF phosphors ( _K2SiF6 : _Mn4 ⁺ ).

As the coloring component, organic or inorganic pigments and dyes can be used alone or in combination of two or more. When a phosphor is used, the amount is 90% by mass or less of the silicone composition, preferably 80% by mass or less, and particularly preferably 70% by mass or less. In addition, a black pigment can be used from the viewpoint of preventing light interference and improving color contrast in a display. Examples of black pigments include iron oxide, aniline black, activated carbon, graphite, carbon nanotubes, and carbon black. The amount of the coloring component is specifically 30% by mass or less of the silicone composition, preferably 15% by mass or less, and particularly preferably 5% by mass or less.

The hot-melt curable silicone composition of the present invention can be prepared by mixing the various components. The method for mixing the various components may be any conventional method known in the art and is not particularly limited, but usually a homogeneous mixture is obtained by simple stirring. Furthermore, when solid components such as inorganic fillers are included as optional components, mixing using a mixing device is more preferable. There are no particular limitations on such mixing devices, and examples include single- or double-screw continuous mixers, twin roll mixers, Ross mixers, Hobart mixers, dental mixers, planetary mixers, kneader mixers, and Henschel mixers.

The hot-melt curable silicone composition of the present invention can exhibit excellent mechanical properties, particularly strength and elongation, even when molded into a film or sheet shape. Therefore, the hot-melt curable silicone composition of the present invention can form a sealant and lamination film for manufacturing semiconductor packages that are easy to handle and can efficiently manufacture semiconductor packages. Therefore, the hot-melt curable silicone composition of the present invention is useful for sheet- or film-like sealants and lamination films when manufacturing semiconductor packages.

[Sealants, films]
The present invention also relates to a semiconductor sealant using the hot-melt curable silicone composition of the present invention. The shape of the sealant of the present invention is not particularly limited, but is preferably a film or sheet. Therefore, the present invention also relates to a film obtained by solidifying the hot-melt curable silicone composition of the present invention. The film of the present invention can be preferably used as a film sealant for sealing semiconductor elements and a film for lamination. The semiconductor sealed by the sealant or film of the present invention is not particularly limited, and examples thereof include semiconductors such as SiC and GaN, particularly optical semiconductors such as power semiconductors or light-emitting diodes.

The sealant or film of the present invention exhibits excellent mechanical properties, particularly strength and elongation, even in the form of a film or sheet, making it easy to handle and allowing semiconductor packages to be manufactured efficiently.

[Optical semiconductor element]
The present invention also relates to an optical semiconductor element comprising the encapsulant of the present invention. Examples of the optical semiconductor element include light-emitting diodes (LEDs), semiconductor lasers, photodiodes, phototransistors, solid-state imaging devices, and light emitters and photoreceivers for photocouplers, and light-emitting diodes (LEDs) are particularly preferred.

Since light-emitting diodes (LEDs) emit light from the top, bottom, left and right of the optical semiconductor element, it is preferable that the components that make up the light-emitting diode (LED) are not light-absorbing, and that they are made of materials with high light transmittance or high reflectance. Therefore, it is preferable that the substrate on which the optical semiconductor element is mounted is also made of materials with high light transmittance or high reflectance. Examples of substrates on which such optical semiconductor elements are mounted include conductive metals such as silver, gold, and copper; non-conductive metals such as aluminum and nickel; thermoplastic resins mixed with white pigments such as PPA and LCP; thermosetting resins containing white pigments such as epoxy resin, BT resin, polyimide resin, and silicone resin; and ceramics such as alumina and alumina nitride.

The optical semiconductor element of the present invention is easy to handle and contains a sealant that allows for efficient production of semiconductor packages, making it highly reliable.

The hot-melt curable silicone composition of the present invention will be described in more detail with reference to the following examples and comparative examples.

[Examples 1 to 22 and Comparative Examples 1 to 5]
Hot-melt curable silicone compositions were prepared by mixing the components in the amounts (parts by weight) shown in Tables 1 to 4. Note that below, Me represents a methyl group, Vi represents a vinyl group, Ph represents a phenyl group, and Ep represents a 3-glycidoxypropyl group.

Component a-1: resin-like alkenyl group-containing organopolysiloxane represented by the average unit formula (ViMeSiO _2/2 ) ₂₅ (Ph ₂ SiO _2/2 ) ₃₀ (PhSiO _3/2 ) ₄₅ Component a-2: resin-like alkenyl group-containing organopolysiloxane represented by the average unit formula (ViMe ₂ SiO _1/2 ) ₂₅ (PhSiO _3/2 ) ₇₅ Component a-3: linear alkenyl group-containing organopolysiloxane represented by the general formula (ViMe ₂ SiO _1/2 ) (PhMeSiO _2/2 ) ₂₀ (ViMe ₂ SiO _1/2 ) Component a-4: general formula (ViMeSiO _2/2 ) Component a-5: a resin-like alkenyl-containing organopolysiloxane represented by the general formula (ViMe ₂ SiO _1/2 ) ₃ (PhSiO _3/2 ); Component b-1: a resin-like organohydrogenpolysiloxane represented by the average unit formula (HMe _{2 SiO 1/2} ) ₆₀ (PhSiO _3/2 ) ₄₀ ; Component b-2: a linear organohydrogenpolysiloxane represented by the general formula (HMe ₂ SiO _1/2 ) (Ph ₂ SiO _2/2 ) (HMe ₂ SiO _1/2 ); Component c-1: an average unit formula (ViMe ₂ SiO _1/2 ) ₂₅ (PhSiO _3/2 ) ₇₅ Component c-2: an additive represented by the structural formula (Me ₂ SiO _2/2 ) (ViMeSiO _2/2 ) (EpSiO _3/2 ); Component c-3: an additive represented by the average unit formula (EpMeSiO _2/2 ) ₄₈ (ViSiO _{3/2 ) 21} (PhSiO _3/2 ) ₃₁ ; Component c-4: an additive represented by the general formula (ViMe ₂ SiO _1/2 ) (Me ₂ SiO _2/2 ) ₃ Si(OMe) ₃ ; Component c-5: an additive represented by the average unit formula ( _{ViMe 2} SiO _1/2 ) ₁₅ (Me ₂ SiO _2/2 ) ₃₅ (PhSiO _3/2 ) ₅₀ Component d: A complex of platinum and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane having a platinum concentration of 4.0% by mass. Component e: 1-ethynyl-2-cyclohexanol (platinum catalyst inhibitor).
Component f: fumed silica Component g: carbon black

[evaluation]
The tensile strength (MPa) and breaking elongation (%) of the cured products of the hot-melt curable silicone compositions of Examples 1 to 22 and Comparative Examples 1 to 5 were measured based on JIS K 6251. Specifically, the hot-melt curable silicone compositions of Examples 1 to 22 and Comparative Examples 1 to 5 were heat-aged at 120°C for 5 to 10 minutes to obtain hot-melt cured products. The melt elastic modulus of these hot-melt cured products at 100°C was 30 to 300 Pa as measured by a viscoelastic meter (MCR302 manufactured by Anton Paar). A test piece was prepared in a shape similar to a dumbbell-shaped No. 3 with a thickness of 180 μm. The tensile strength (MPa) and breaking elongation (%) were measured using this test piece at a pulling speed of 500 mm/min. The results are shown in Tables 1 to 4. It can be said that a film having a tensile strength of 1 MPa or more and a breaking elongation of 200% or more has excellent handling and workability as a sealant film or a laminate film.

The hot-melt curable silicone composition of the present invention can be formed into a film or sheet that has excellent handling and workability, making it useful for use as a sheet- or film-like sealant and lamination film in the manufacture of semiconductor packages.

Claims (7)

(A) an alkenyl-containing organopolysiloxane having at least two alkenyl groups in one molecule, the alkenyl-containing organopolysiloxane including a resin-like organopolysiloxane that contains an alkenyl group and at least one (Ar ₂ SiO _2/2 ) unit (wherein Ar represents an aryl group), and in which the ratio of the (Ar ₂ SiO _2/2 ) unit to the total amount of siloxane units in the molecular structure of component (A) is 0.05 or more and 0.5 or less ;
(B) 0.1 to 5 mass %, based on the total mass of the composition, of a resin-like organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in each molecule;
(B') a linear organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in each molecule;
(C) Average unit formula (C-1):
(R ¹ ₃ SiO _1/2 ) _a (R ¹ ₂ SiO _2/2 ) _b (R ¹ SiO _3/2 ) _c
(In the formula, R ¹ 's are the same or different and are an alkyl group, an aryl group, an alkenyl group, an aralkyl group, an epoxy group-containing organic group, or an alkoxy group, with the proviso that at least one R ¹ is an alkenyl group and at least one R ¹ is an epoxy group-containing organic group, and a, b, and c are numbers that satisfy 0≦a≦1.0, 0≦b≦1.0, 0≦c<0.9, and a+b+c=1.)
(D) a hydrosilylation reaction catalyst; and (E) silica in an amount of 20% by mass or less based on the total mass of the composition,
(E) the amount of inorganic fillers other than silica is 20% by mass or less based on the total mass of the composition ;
A solvent-free hot-melt curable silicone composition. The hot-melt curable silicone composition according to claim 1, wherein component (A) further comprises an alkenyl-group-containing linear organopolysiloxane. The component (B) has the average unit formula (B-1):
(R ³ ₃ SiO _1/2 ) _a (R ³ ₂ SiO _2/2 ) _b (R ³ SiO _3/2 ) _c (SiO _4/2 ) _d (XO _1/2 ) _e
3. The hot-melt curable silicone composition according to claim 1, represented by the formula: (wherein ^R3 's are the same or different hydrogen atoms or halogen-substituted or unsubstituted monovalent hydrocarbon groups, with the proviso that at least two ^R3 's are hydrogen atoms, X is a hydrogen atom or an alkyl group, and a, b, c, d, and e are numbers that satisfy 0≦a≦1.0, 0≦b≦1.0, 0≦c<0.9, 0≦d<0.5, 0≦e<0.4, a+b+c+d=1.0, and c+d>0). The curable silicone composition according to any one of claims 1 to 3, comprising a cyclic organopolysiloxane as component (A). A film obtained by solidifying the hot-melt curable silicone composition according to any one of claims 1 to 4. A sealant comprising the hot-melt curable silicone composition according to any one of claims 1 to 4. An optical semiconductor element containing the encapsulant of claim 6.