CN106947258B

CN106947258B - Addition-curable silicone resin composition and semiconductor device

Info

Publication number: CN106947258B
Application number: CN201611196873.XA
Authority: CN
Inventors: 井口洋之; 楠木贵行
Original assignee: Shin Etsu Chemical Co Ltd
Current assignee: Shin Etsu Chemical Co Ltd
Priority date: 2015-12-22
Filing date: 2016-12-22
Publication date: 2021-06-25
Anticipated expiration: 2036-12-22
Also published as: JP6657037B2; CN106947258A; JP2017115116A

Abstract

The invention relates to an addition-curable silicone resin composition and a semiconductor device, and aims to provide an addition-curable silicone composition which has good low-temperature characteristics and can form a cured product with excellent temperature change resistance, and a semiconductor device which is packaged with the cured product of the composition and has high reliability. The addition-curable silicone resin composition contains (A) a branched organopolysiloxane represented by the following formula (1), (B) an organopolysiloxane represented by the following formula (2), (C) an organopolysiloxane having at least 2 hydrosilyl groups in the molecule, and (D) a hydrosilylation catalyst, in specific amounts, respectively. Formula (1)

In the formula, R¹、R²A, b, c, etc. are as defined in the specification, formula (2) (R)² ₃SiO_1／2）_r（R² ₂SiO_2／2）_ｓ（R²SiO_３／2）_ｔ（SiO_4／2）_ｕ(2) In the formula, R²R, s, t, u, etc. are as defined in the specification.

Description

Addition-curable silicone resin composition and semiconductor device

Technical Field

The present invention relates to an addition-curable silicone composition, and particularly to an addition-curable silicone composition containing an alkenyl-containing branched organopolysiloxane (branched オルガノポリシロキサン) having a siloxane branch with a long chain length, and a semiconductor device in which a semiconductor is encapsulated by a cured product thereof.

Background

Addition-curable silicone resins have been used as encapsulating materials for encapsulating semiconductor elements such as LEDs because of their excellent heat resistance, light resistance, quick-setting properties, and the like. For example, patent document 1 describes an addition curing silicone resin that exhibits high adhesive force to an LED package made of a thermoplastic resin such as PPA. Patent document 2 describes a method of encapsulating an optical semiconductor element by compression molding of an addition-curable silicone resin composition.

As described above, addition-curable silicone resins are widely and generally used as semiconductor encapsulating materials, but their properties are still unsatisfactory. In particular, the LED package material is exposed to not only internal pressure due to temperature change caused by ON/OFF of the optical semiconductor device but also external pressure due to changes in air temperature, humidity, and the like, and therefore, in addition to heat resistance and light resistance, cold resistance is also important. However, conventional addition-curable silicone resins are not sufficient in terms of low-temperature characteristics, and have a problem that they cannot withstand the pressure of temperature changes and crack.

As one means for improving the low-temperature characteristics, it is known that it is effective to have a branched structure in a linear silicone chain (シリコーン knee-lock), and various studies have been made on the production methods thereof (patent documents 1, 2, and 3). However, when an acid catalyst or a base catalyst is used, such R is contained³SiO_1/2Unit [ M unit ] and RSiO_3/2In the method of condensing/equilibrating hydrolyzable silanes of the unit [ T unit ], the chain lengths of the main chain and the side chain cannot be independently controlled, and it is difficult to obtain a siloxane of a desired structure.

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent application laid-open No. 2006 and 256603

[ patent document 2 ] Japanese patent application laid-open No. 2006-93354

[ patent document 3 ] Japanese patent laid-open No. 2002-348377

[ patent document 4 ] Japanese patent laid-open No. 2001-163981

[ patent document 5 ] Japanese patent laid-open No. 2000-351949.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object of the present invention is to provide an addition-curable silicone composition which has good low-temperature characteristics and can form a cured product having excellent temperature change resistance, and a highly reliable semiconductor device in which a semiconductor element is encapsulated by a cured product of the composition.

That is, the present invention provides an addition-curable silicone composition containing the following components (a) to (D).

An addition-curable silicone resin composition comprising:

(A) a branched organopolysiloxane represented by the following formula (1)

(in the formula, R¹Independently of each other, a group selected from a substituted or unsubstituted saturated hydrocarbon group having 1 to 12 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, R²Independently of each other, a group selected from a C1-12 substituted or unsubstituted saturated hydrocarbon group, a C6-12 substituted or unsubstituted aromatic hydrocarbon group, and a C2-10 alkenyl group, and each R¹、R²May be the same or different, wherein R is²At least 2 of the above groups are alkenyl groups, a is an integer of 2 to 100, b is an integer of 5 to 100, c is an integer of 5 to 100, a/(a + b) < 1.0 and 0.03 ≤ and (R)¹ ₂R²SiO_1/2) Of a unitquantity/(R)²SiO_3/2) The number of units is less than or equal to 2, and the arrangement of the siloxane chains of a, b and c can be random or block);

(B) an organopolysiloxane represented by the following formula (2)

（R² ₃SiO_1/2）_r（R² ₂SiO_2/2）_s（R²SiO_3/2）_t（SiO_4/2）_u　（2）

(in the formula, R²Is as defined above, R²At least 2 of which are alkenyl groups, r is an integer of 0 to 100, s is an integer of 0 to 300, t is an integer of 0 to 200, u is an integer of 0 to 200, t + u is 1. ltoreq. t + u.ltoreq.400, r + s + t + u is 2. ltoreq. r + 800),

the amount of the component (B) is 5 to 900 parts by mass per 100 parts by mass of the component (A);

(C) an organopolysiloxane having at least 2 hydrosilyl groups (ヒドロシリル groups) in the molecule,

the amount of the component (C) is such that the number of hydrosilyl groups in the component (C) is 0.4 to 4.0 relative to the total number of alkenyl groups in the components (A) and (B); and

(D) hydrosilylation catalyst (ヒドロシリル catalyst)

The amount of the component (D) is a sufficient amount for the hydrosilylation reaction to proceed.

According to the present invention, by combining a specific other component with a branched organopolysiloxane containing an alkenyl group and containing a large amount of side chains sufficiently longer than the siloxane chain length of the main chain, the glass transition temperature of the cured product is lowered and the crack resistance and the like are improved as compared with the case of using a linear organopolysiloxane having the same degree of main chain length.

Brief description of the drawings

Fig. 1 is a graph of storage elastic modulus (storage elastic modulus) and a graph of Tan δ of cured products of example 1 (solid line) and comparative example 1 (broken line).

Detailed Description

The present invention is described in detail below.

(A) Branched polyorganosiloxanes

The branched polyorganosiloxane (A) which is one of the features of the present invention is represented by the following formula.

(A) A branched organopolysiloxane represented by the following formula (1)

(in the formula, R¹Independently of each other, a group selected from a substituted or unsubstituted saturated hydrocarbon group having 1 to 12 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, R²Independently of each other, a group selected from a C1-12 substituted or unsubstituted saturated hydrocarbon group, a C6-12 substituted or unsubstituted aromatic hydrocarbon group, and a C2-10 alkenyl group, and each R¹、R²May be the same or different, wherein R is²At least 2 of the above groups are alkenyl groups, a is an integer of 2 to 100, b is an integer of 5 to 100, c is an integer of 5 to 100, a/(a + b) < 1.0 and 0.03 ≤ and (R)¹ ₂R²SiO_1/2) Number of units/(R)²SiO_3/2) The number of units is less than or equal to 2, the arrangement of the siloxane chains of a, b and c can be random or block).

a is an integer of 2 to 100, preferably 2 to 75, more preferably 2 to 50, b is an integer of 5 to 100, preferably 5 to 75, more preferably 10 to 50, c is an integer of 5 to 100, preferably 5 to 75, more preferably 10 to 50. (R)¹ ₂R²SiO_1/2) Number of units/(R)²SiO_3/2) The number of units is 2 or less, and the arrangement of the siloxane chains of a and b (i.e., the siloxane chains of a and b, シロキサン knee-lock) may be random or block.

In the formula (1), 0.03. ltoreq. a/(a + b) < 1.0, preferably 0.09. ltoreq. a/(a + b) < 0.9.

R¹Independently of each other, a group selected from a substituted or unsubstituted saturated hydrocarbon group having 1 to 12 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, and examples of the saturated hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, butyl, and octyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; a group in which some or all of the hydrogen atoms bonded to carbon atoms are substituted with a halogen atom such as fluorine, bromine or chlorine or a cyano group, for example, a halogenated monovalent hydrocarbon group such as trifluoropropyl or chloropropyl; cyanoalkyl groups such as β -cyanoethyl and γ -cyanopropyl, 3-methacryloxypropyl, 3-epoxypropyloxypropyl, 3-mercaptopropyl, and 3-aminopropyl. Among them, methyl, cyclohexyl and the like are preferable, and methyl is particularly preferable. Examples of the aromatic hydrocarbon group include aryl groups such as phenyl, tolyl, and naphthyl, and aralkyl groups such as benzyl, phenethyl, and phenylpropyl. Some or all of the hydrogen atoms bonded to carbon atoms in these groups may be substituted with a halogen atom such as fluorine, bromine, chlorine, or a cyano group. Among them, phenyl and tolyl are preferable, and phenyl is particularly preferable. R¹At least 1 of them is preferably an aromatic hydrocarbon group having 6 to 12 carbon atoms.

R²Independently of each other, a group selected from a substituted or unsubstituted saturated hydrocarbon group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, preferably 6 to 10 carbon atoms, and an alkenyl group having 2 to 10 carbon atoms, preferably 2 to 8 carbon atoms. Examples of the saturated hydrocarbon group and the aromatic hydrocarbon group include those mentioned for R¹The groups exemplified are the same. Examples of the alkenyl group include vinyl, allyl, propenyl, hexenyl, and styryl groups, with vinyl and allyl groups being preferred and vinyl groups being particularly preferred.

In the component (a), the proportion of the number of 1-valent aromatic hydrocarbon groups in the total number of all substituents bonded to silicon atoms is preferably 3% or more, particularly preferably 5% or more, preferably 90% or less, particularly preferably 80% or less. If the content is within this range, the branched organopolysiloxane of component (A) has a high refractive index and low gas permeability, and therefore the composition can be suitably used for the purpose of encapsulating semiconductor devices and the like.

(A) The branched organopolysiloxane can be produced by co-condensing an organopolysiloxane represented by the following formula (4) with a siloxane, for example, an organopolysiloxane represented by the following formula (5) having alkoxysilyl groups or hydroxysilyl groups (silanol groups) at both ends, followed by end-capping with a silane, for example, a silane compound containing a hydrolyzable group represented by the following formula (6),

(in the formula, R¹、R²C is the same as above, R³Is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms)

(in the formula, R²、R³B' is 1 or more and b or less, and b is the same as above)

(in the formula, R¹、R²X is a halogen atom or R³O-［R³The same as described above).

In the formula (4), R³Examples of the group selected from a hydrogen atom and a saturated hydrocarbon group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a hexyl group and a cyclohexyl group. Among them, methyl, ethyl and the like are preferable, and methyl is particularly preferable.

The organopolysiloxane having a dialkoxy group at one end represented by the above formula (4) can be synthesized by a known method. For example, the following methods are available: a method of ring-opening polymerizing a cyclic silicon compound using a metal silanolate as an initiator to terminate the terminal with an acid and then reacting the terminal with a trialkoxysilane, as disclosed in Japanese patent application laid-open No. 59-78236, or a method of polymerizing a cyclic silicon compound using a silanol compound as an initiator and pentacoordinate silicon as a catalyst to react the terminal with a trialkoxysilane, as disclosed in Japanese patent application laid-open No. 7-224168.

(B) Organic siloxane

(B) The organosiloxane is represented by the following formula (2).

(in the formula, R²Is as defined above, R²At least 2 of the above groups are alkenyl groups, r is an integer of 0 to 100, s is an integer of 0 to 300, t is an integer of 0 to 200, u is an integer of 0 to 200, t + u is 1. ltoreq. t + u.ltoreq.400, r + s + t + u is 2. ltoreq. r + s + u.ltoreq.800)

Wherein r is an integer of 0 to 100, preferably 0 to 75, and more preferably 0 to 50, s is an integer of 0 to 300, preferably 0 to 200, and more preferably 0 to 100, t is an integer of 0 to 200, preferably 0 to 100, and more preferably 0 to 50, and u is an integer of 0 to 200, preferably 0 to 100, and more preferably 0 to 50, 1. ltoreq. t + u.ltoreq.400, preferably 1. ltoreq. t + u.ltoreq.200, more preferably 1. ltoreq. t + u.ltoreq.100, 2. ltoreq. r + s + t + u.ltoreq.800, preferably 2. ltoreq. r + s + t + u.ltoreq.400, and more preferably 2. ltoreq. r + s + t + u.ltoreq.200.

R²Examples of (A) are as for R in the above-mentioned component (A)²Examples of such are illustrated.

In the component (B), the proportion of the number of 1-valent aromatic hydrocarbon groups in the total number of all substituents bonded to silicon atoms is preferably 3% or more, particularly preferably 5% or more, preferably 90% or less, particularly preferably 80% or less. When the content is within this range, the branched organopolysiloxane of component (B) has a high refractive index, low air permeability, and good compatibility with component (A), and the cured product of the composition containing the branched organopolysiloxane has excellent transparency and excellent mechanical strength. Therefore, the composition can be suitably used for the purpose of encapsulating a semiconductor device, and the like.

(B) The amount of component (A) is 5 to 900 parts by mass, preferably 10 to 800 parts by mass, and more preferably 20 to 600 parts by mass per 100 parts by mass of component (A). When the component (B) is contained in an amount within the above range, a rubbery cured product can be obtained, which is preferred.

(C) Organopolysiloxane having at least 2 hydrosilyl groups in a molecule

(C) The organopolysiloxane having at least 2 hydrosilyl groups in the molecule is not particularly limited, but is preferably represented by the following formula (3).

（R³ ₃SiO_1/2）_r’（R³ ₂SiO_2/2）_s’（R³SiO_3/2）_t’（SiO_4/2）_u’　（3）

(in the formula, R³Is a hydrogen atom, a substituted or unsubstituted saturated hydrocarbon group having 1 to 12 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, provided that R is³At least 2 of them are hydrogen atoms, r 'is an integer of 0 to 100, s' is an integer of 0 to 300, t 'is an integer of 0 to 200, u' is an integer of 0 to 200, and 2. ltoreq. r '+ s' + t '+ u'. ltoreq.800).

Wherein the substituted or unsubstituted saturated hydrocarbon group having 1 to 12 carbon atoms or the substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms may be represented by R¹The groups exemplified. At R³Of (3), at least 2 are hydrogen atoms, and others are preferably methyl groups or phenyl groups. r 'is an integer of 0 to 100, preferably 0 to 75, and more preferably 0 to 50, s' is an integer of 0 to 300, preferably 0 to 200, and more preferably 0 to 100, t 'is an integer of 0 to 200, preferably 0 to 100, and more preferably 0 to 50, u' is an integer of 0 to 200, and more preferably 0 to 100Further, it is preferably an integer of 0 to 50, more preferably in the range of 2. ltoreq. r '+ s' + t '+ u' to 800, still more preferably in the range of 2. ltoreq. r '+ s' + t '+ u' to 400, and still more preferably in the range of 2. ltoreq. r '+ s' + t '+ u' to 200.

The proportion of the number of 1-valent aromatic hydrocarbon groups bonded to silicon atoms in all the substituents of component (C) is preferably 3% or more, and more preferably 5% or more and 80% or less. When the content is within this range, the organopolysiloxane of component (C) has a high refractive index and low gas permeability, and is well compatible with components (A) and (B), and therefore, a composition having excellent transparency of a cured product is formed. Therefore, the present invention can be suitably used for packaging applications of semiconductor devices and the like.

The amount of the organopolysiloxane having at least 2 hydrosilyl groups in the molecule as component (C) is 0.4 to 4.0, preferably 0.6 to 2.0, and more preferably 0.8 to 1.6 relative to the total number of alkenyl groups of components (A) and (B). When the content is less than 0.4, the content of SiH groups is insufficient, and therefore, curing is not preferable, and when the content exceeds 4.0, side reactions such as dehydrogenation due to residual SiH groups are liable to occur, which is not preferable.

(D) Hydrosilylation catalysts

The catalyst is not particularly limited as long as it has an ability to progress the hydrosilylation reaction. Among them, preferred is a catalyst selected from platinum group metal monomers and platinum group metal compounds. Examples thereof include platinum (containing platinum black), platinum chloride, platinum-olefin complexes such as chloroplatinic acid and platinum-divinylsiloxane complexes, platinum catalysts such as platinum-carbonyl complexes, palladium catalysts, rhodium catalysts, and the like. These catalysts may be used alone, or 2 or more of them may be used in combination. Among them, platinum-olefin complexes such as chloroplatinic acid and platinum-divinylsiloxane complexes are particularly preferable.

(D) The compounding amount of the ingredient is preferably a catalyst amount. The amount of the catalyst is such that the hydrosilylation reaction is promotedThe amount of the curing agent may be appropriately adjusted according to the desired curing rate. For example, in the case of a platinum group metal catalyst, it is preferably 1.0X 10 parts by mass based on the mass of the platinum group metal atom in terms of the total 100 parts by mass of the components (A) to (C) in view of the reaction rate^-4An amount of 1.0 part by mass, more preferably 1.0X 10 parts by mass based on 100 parts by mass of the total of the components (A) to (C)^-3～1.0×10^-1Amount of mass parts.

Optional ingredients

The curable composition of the present invention may contain, in addition to the above-mentioned components (a) to (D), other components, for example, a phosphor, an inorganic filler, a binder auxiliary, a curing inhibitor, and the like, as required. Hereinafter, each component will be described.

[ phosphor ]

The phosphor is not particularly limited as long as a conventionally known phosphor is used. For example, a substance which absorbs light emitted from a semiconductor element, particularly a semiconductor light emitting diode having a nitride semiconductor as a light emitting layer, and which is wavelength-converted into light having a different wavelength is preferable. Such phosphors are preferably selected from, for example, nitride-based phosphors/oxynitride-based phosphors mainly activated by lanthanoid elements such as Eu and Ce, alkaline earth metal halogen apatite phosphors mainly activated by lanthanoid elements such as Eu and transition metal elements such as Mn, alkaline earth metal borate halogen phosphors, alkaline earth metal aluminate phosphors, and alkaline earth metal silicate phosphors, 1 or more of an alkaline earth metal sulfide phosphor, an alkaline earth metal thiogallate phosphor, an alkaline earth metal silicon nitride phosphor, a germanate phosphor, a rare earth aluminate phosphor mainly activated by a lanthanoid such as Ce, a rare earth silicate phosphor, an organic and organic complex phosphor mainly activated by a lanthanoid such as Eu, a Ca-Al-Si-O-N oxynitride glass phosphor, and the like.

Examples of the nitride-based phosphor mainly activated by lanthanoid elements such as Eu and Ce include M₂Si₅N₈: eu (M is selected from Sr, Ca, Ba,At least 1 of Mg and Zn). In addition, MSi can be cited₇N₁₀：Eu、M_1.8Si₅O_0.2N₈: eu, and M_0.9Si₇O_0.1N₁₀: eu (M is at least 1 selected from Sr, Ca, Ba, Mg and Zn), etc.

Examples of the oxynitride-based phosphor mainly activated by a lanthanide such as Eu or Ce include MSi₂O₂N₂: eu (M is at least 1 selected from Sr, Ca, Ba, Mg and Zn).

As the alkaline earth metal halogen apatite phosphor mainly activated by a transition metal element such as lanthanide or Mn, e.g., Eu, M is exemplified₅（PO₄）₃X: r (M is at least 1 selected from Sr, Ca, Ba, Mg and Zn, X is at least 1 selected from F, Cl, Br and I, R is any more than 1 of Eu, Mn, Eu and Mn).

As the alkaline earth metal borate halogen phosphor, M is exemplified₂B₅O₉X: r (M is at least 1 selected from Sr, Ca, Ba, Mg and Zn, X is at least 1 selected from F, Cl, Br and I, R is any more than 1 of Eu, Mn, Eu and Mn).

As the alkaline earth metal aluminate phosphor, SrAl is exemplified₂O₄：R、Sr₄Al₁₄O₂₅：R、CaAl₂O₄：R、BaMg₂Al₁₆O₂₇：R、BaMg₂Al₁₆O₁₂: r, and BaMgAl₁₀O₁₇: r (R is any more than 1 of Eu, Mn, Eu and Mn).

As the alkaline earth metal sulfide phosphor, La is exemplified₂O₂S：Eu、Y₂O₂S: eu and Gd₂O₂S: eu, and the like.

Examples of the rare earth aluminate phosphor mainly activated by lanthanoid such as Ce include Y₃Al₅O₁₂：Ce、（Y_0.8Gd_0.2）₃Al₅O₁₂：Ce、Y₃（Al_0.8Ga_0.2）₅O₁₂: ce. And (Y, Gd)₃（Al，Ga）₅O₁₂A YAG phosphor represented by the following composition formula. In addition, Tb may be obtained by replacing a part or all of Y with Tb or Lu₃Al₅O₁₂：Ce、Lu₃Al₅O₁₂: ce, and the like.

Among other phosphors, mention may be made of ZnS: eu, Zn₂GeO₄：Mn、MGa₂S₄: eu (M is at least 1 selected from Sr, Ca, Ba, Mg and Zn, X is at least 1 selected from F, Cl, Br and I) and the like.

The phosphor may contain 1 or more kinds selected from Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni and Ti instead of Eu, or may contain 1 or more kinds selected from Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni and Ti in addition to Eu, as necessary.

The Ca-Al-Si-O-N oxynitride glass phosphor is a phosphor comprising an oxynitride glass as a matrix material, wherein CaCO is contained in the oxynitride glass in mol%₃20 to 50 mol% of Al in terms of CaO₂O₃0 to 30 mol%, 25 to 60 mol% SiO, 5 to 50 mol% AlN, 0.1 to 20 mol% rare earth oxide or transition metal oxide, and the total of 5 components is 100 mol%. In the phosphor using oxynitride glass as a matrix material, the nitrogen content is preferably 15 wt% or less, and it is preferable that ions of other rare earth elements forming a sensitizer in addition to the rare earth oxide ions are contained as the rare earth oxide, and the content of the co-activator in the fluorescent glass is in the range of 0.1 to 10 mol%.

In addition, phosphors other than the above-described phosphors, that is, phosphors having the same performance and effect may be used.

The amount of the phosphor is preferably 0.1 to 2000 parts by mass, and more preferably 0.1 to 100 parts by mass, based on 100 parts by mass of the components other than the phosphor, for example, (A) to (D). When the cured product of the present invention is used as a wavelength conversion film containing a phosphor, the content of the phosphor is preferably 10 to 2000 parts by mass. The phosphor preferably has an average particle diameter of 10nm or more, more preferably 10nm to 10 μm, and still more preferably 10nm to 1 μm. The average particle diameter can be measured by particle size distribution measurement using a laser diffraction method using an シーラス (CIRRUS) laser measurement device or the like.

[ inorganic Filler ]

Examples of the inorganic filler include silica, fumed titania, alumina, calcium carbonate, calcium silicate, titanium dioxide, iron sesquioxide, zinc oxide, and the like. These may be used alone in 1 kind, or more than 2 kinds may be used in combination. The amount of the inorganic filler is not particularly limited, and may be appropriately blended in the range of 20 parts by mass or less, preferably 0.1 to 10 parts by mass, per 100 parts by mass of the total of the components (a) to (D).

[ Adhesives ]

The curable composition of the present invention preferably contains an adhesion promoter as necessary for imparting adhesion. Examples of the adhesion promoter include organosiloxane oligomers having at least 2, preferably 3 functional groups selected from a hydrogen atom, an alkenyl group, an alkoxy group, and an epoxy group bonded to a silicon atom in one molecule. The organosiloxane oligomer preferably has 4 to 50 silicon atoms, more preferably 4 to 20 silicon atoms. Further, as the adhesion aid, an organoxysilyl-modified isocyanurate compound represented by the following general formula (7) and a hydrolysis condensate thereof (organosiloxane-modified isocyanurate compound) can be used.

In the above formula (7), R⁴Independently of each other, an organic group represented by the following (8) or a monovalent hydrocarbon group having an aliphatic unsaturated bond.

R⁵Is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, and k is an integer of 1 to 6, preferably an integer of 1 to 4.

The amount of the adhesion promoter to be blended is preferably 10 parts by mass or less, more preferably 0.1 to 8 parts by mass, and particularly preferably 0.2 to 5 parts by mass, per 100 parts by mass of the total of the components (a) to (D). If the amount of the additive is less than the above upper limit, the hardness of the cured product becomes high, and the surface tackiness can be suppressed.

[ curing inhibitor ]

The curable composition of the present invention preferably contains a curing inhibitor for the purpose of controlling reactivity and improving storage stability. Examples of the curing inhibitor include compounds selected from the group consisting of triallyl isocyanurate, alkyl maleates, acetylene alcohols, silane-modified products and siloxane-modified products thereof, hydrogen peroxide, tetramethylethylenediamine, benzotriazole, and mixtures thereof. The amount of the curing inhibitor is preferably 0.001 to 1.0 part by mass, and more preferably 0.005 to 0.5 part by mass, per 100 parts by mass of the total of the components (A) to (D).

[ other additives ]

In the curable composition of the present invention, other additives may be blended in addition to the above components. Examples of the other additives include an antioxidant, a radical inhibitor (ラジカル inhibitor), a flame retardant, a surfactant, an ozone deterioration inhibitor, a light stabilizer, a thickener, a plasticizer, an antioxidant, a heat stabilizer, a conductivity-imparting agent, an antistatic agent, a radiation cut-off agent, a nucleating agent, a phosphorus-based peroxide decomposer, a lubricant, a pigment, a metal deactivator, a physical property modifier, and an organic solvent. These optional components may be used alone or in combination of two or more.

The curable composition of the present invention in the simplest embodiment is a composition comprising component (a), component (B), component (C), and component (D). The composition preferably comprises component (A), component (B), component (C), component (D) and a fluorescent material. In particular, in order to obtain a cured product having high transparency, an inorganic filler containing no silica filler or the like is suitable. Examples of the inorganic filler are as described above.

The method for producing the curable composition of the present invention is not particularly limited, and the curable composition can be produced by a conventionally known method. For example, the component (a), the component (B), the component (C), and the component (D) can be mixed by an arbitrary method. Alternatively, the phosphor may be mixed with the components (a), (B), (C), and (D) or the components (a), (B), (C), and (D) and any other components by any method. For example, the composition can be prepared by uniformly mixing the mixture in a commercially available MIXER (e.g., a THINKY CONDITIONING MIXER (manufactured by KOKAI) シンキー) for about 1 to 5 minutes.

The method for curing the curable composition of the present invention is not particularly limited, and the curing may be carried out according to a conventionally known method. For example, the curing time may be about 1 to 12 hours at 60 to 180 ℃. In particular, it is preferable to carry out curing by stepwise curing (ステップキュア) at 60 to 150 ℃. More preferably, in the stepwise curing, the following 2 stages are passed. First, the curable composition is heated at 60 to 100 ℃ for 0.5 to 2 hours to sufficiently defoam the composition. Then, the curable composition is cured by heating at a temperature of 120 to 180 ℃ for 1 to 10 hours. By passing through these steps, even when the cured product is thick, the cured product can be sufficiently cured without generating bubbles, and can have colorless transparency. In the present invention, the colorless and transparent cured product is a material having a light transmittance of 80% or more, preferably 85% or more, and particularly preferably 90% or more, at a thickness of 1mm and at 450 nm.

The curable composition of the present invention can form a cured product having high optical transmittance. Therefore, the curable composition of the present invention is useful for encapsulating LED elements, particularly blue LEDs and ultraviolet LEDs. The method for sealing an LED element or the like with the curable composition of the present invention may be a conventionally known method. For example, the method can be carried out by a distribution method (ディスペンス method), a compression molding method, or the like.

The curable composition and the cured product of the present invention are useful for applications such as display materials, optical recording materials, optical instrument materials, optical component materials, optical fiber materials, optical/electronic functional organic materials, semiconductor integrated circuit peripheral materials, and the like, because they form cured products having excellent characteristics such as crack resistance, heat resistance, light resistance, and transparency in addition to the above-mentioned properties.

Examples

The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the examples below.

The weight average molecular weight (Mw) shown in the following examples is a value measured by Gel Permeation Chromatography (GPC) using polystyrene as a standard substance. The measurement conditions are shown below.

[ GPC measurement conditions ]

Developing solvent: tetrahydrofuran (THF)

Flow rate: 0.6mL/min

Column: SuperH-L protective column for TSK

TSKgel SuperH4000（6.0mmＩ.D.×15cm×1）

TSKgel SuperH3000（6.0mmＩ.D.×15cm×1）

TSKgel SuperH2000（6.0mmＩ.D.×15cm×2）

(both made by the company of Chinese imperial ceramics ソー)

Column temperature: 40 deg.C

Sample injection amount: 20 μ L (sample concentration: 0.5 wt% -tetrahydrofuran solution)

A detector: differential Refractometer (RI)

Vi values (Vi value) (mol/100 g) and SiH values (SiH value) (mol/100 g) shown in the examples below were determined from the 400MHz of the test compound¹H-NMR spectrum, value calculated from the integral value of hydrogen atoms obtained using dimethyl sulfoxide as an internal standard.¹H-NMR measurement Using ULTRASHIELD^TM400PLUS (manufactured by BRUKER Co., Ltd.),²⁹Si-NMR measurement was carried out using RESONANCE500 (JEOL).

The following examples of synthesizing the component (a) used in the examples and comparative examples are given. In the following, Me represents a methyl group, and Ph represents a phenyl group.

[ Synthesis example 1]

（a-1）

96.3g of lithium trimethylsilanolate, 1560g of hexamethylcyclotrisiloxane and 4160g of hexaphenylcyclotrisiloxane were added to a toluene solvent, and the mixture was stirred at 100 ℃ for 12 hours. Then, 90.0g of acetic acid was added for neutralization, and the resultant was filtered. Then, 408g of methyltrimethoxysilane, Sr (OH)₂・8H₂O8.10 g, and stirred at 60 ℃ for 3 hours. Then, 12.2g of acetic acid was added thereto to neutralize the reaction product, and the obtained product was filtered, and methanol and toluene were distilled off under reduced pressure, thereby synthesizing the following organopolysiloxane (a-1) having 2 alkoxy groups at one end. Mw is found to be 6000.

(wherein c ═ 20).

（A-1）

600g of the organopolysiloxane synthesized in (a-1), 140g of polymethylphenylsiloxane- α, ω -diol (Mw ═ 530), Sr (OH) were added₂・8H₂O0.810 g, stirred at 60 ℃ for 18 hours. Then, 1.22g of acetic acid was added thereto to neutralize the reaction solution, 17.1g of chlorodimethylvinylsilane was added thereto, and the mixture was stirred at 60 ℃ for 8 hours. The obtained product was filtered, washed with water, azeotropically dehydrated, and distilled under reduced pressure to remove the water, thereby synthesizing the following branched silicone oil. It can be seen that the Mw is 27000 and the Vi value is 7.41 × 10^-3mol/100g of²⁹The Si-NMR spectrum gave organopolysiloxane (a-1) with a ═ 4, b ═ 40, c ═ 20, and c ═ 20.

[ Synthesis example 2 ]

（a-2）

96.3g of lithium trimethylsilanolate, 222g of hexamethylcyclotrisiloxane and hexaphenylcyclotrisiloxane were added to a toluene solvent595g, stirring at 100 ℃ for 3 hours. Then, 90.0g of acetic acid was added for neutralization, and the resultant was filtered. Then, 408g of methyltrimethoxysilane, Sr (OH)₂・8H₂O8.10 g, and stirred at 60 ℃ for 3 hours. Then, 12.2g of acetic acid was added thereto to neutralize, the resultant was filtered, and methanol and toluene were distilled off under reduced pressure, whereby the following one-terminal dialkoxyorganopolysiloxane (a-2) was synthesized. Mw is 1000.

(wherein c ═ 3).

（A-2）

100g of the organopolysiloxane synthesized in (a-2), 27.9g of polymethylphenylsiloxane- α, ω -diol (Mw ═ 530), Sr (OH) were added₂・8H₂O0.640 g, and stirred at 60 ℃ for 3 hours. Then, 0.960g of acetic acid was added thereto to neutralize the reaction solution, and 24.4g of chlorodimethylvinylsilane was added thereto and stirred at 60 ℃ for 8 hours. The obtained product was filtered, washed with water, azeotropically dehydrated, and distilled under reduced pressure to remove the water, thereby synthesizing the following branched silicone oil. The Mw was 3300 and Vi was 6.06 × 10^-2mol/100g of²⁹The Si NMR spectrum yields organopolysiloxanes with a ═ 3, b ═ 6, c ═ 3, and c ═ 3.

[ Synthesis example 3 ]

（a-3）

90.1g of trimethylsilanol, 6660g of hexamethylcyclotrisiloxane, and 121g of sodium bis-catechol phenylmethylsiloxy (ジカテコールフェニルシロキシナトリウム) were added to an acetonitrile solvent, and the mixture was stirred at 60 ℃ for 12 hours. The resulting product was filtered and methyltrimethoxysilane 408g, Sr (OH) was added₂・8H₂O8.10 g, and stirred at 60 ℃ for 3 hours. Then, 12.2g of acetic acid was added thereto for neutralization, and the resultant was filteredThe methanol and toluene were distilled off under reduced pressure, whereby the following one-terminal dialkoxy organopolysiloxane was synthesized. Mw is 6800.

(wherein c is 90).

（A-3）

680g of the organopolysiloxane synthesized in (a-3), 72.0g of polydimethylsiloxane- α, ω -diol (Mw ═ 280), Sr (OH) were added₂・8H₂O3.76 g, stirred at 60 ℃ for 18 hours. Then, 5.64g of acetic acid was added thereto to neutralize the reaction solution, 13.0g of chlorodimethylvinylsilane was added thereto, and the mixture was stirred at 60 ℃ for 8 hours. The resulting product was filtered, washed with water, azeotropically dehydrated, and distilled off under reduced pressure, whereby the following branched silicone oil was synthesized. It can be seen that the Mw is 73000 and the Vi value is 2.74 × 10^-3mol/100g of²⁹The Si NMR spectrum yields organopolysiloxanes with a ═ 10, b ═ 90, and c ═ 90.

[ Synthesis example 4 ]

（a-4）

90.1g of trimethylsilanol, 890g of hexamethylcyclotrisiloxane and 121g of sodium bis-catechol phenylmethylsiloxy were added to an acetonitrile solvent, and the mixture was stirred at 60 ℃ for 6 hours. The resulting product was filtered and methyltrimethoxysilane 408g, Sr (OH) was added₂・8H₂O8.10 g, and stirred at 60 ℃ for 3 hours. Then, 12.2g of acetic acid was added thereto to neutralize, the resultant was filtered, and methanol and toluene were distilled off under reduced pressure, whereby the following one-terminal dialkoxy organopolysiloxane was synthesized. Mw is 1000.

(wherein c is 12).

（A-4）

1000g of the organopolysiloxane synthesized in (a-4), 12.0g of polydimethylsiloxane- α, ω -diol (Mw ═ 280), Sr (OH), and the like were added₂・8H₂O5.06 g, stirred at 60 ℃ for 18 hours. Then, 7.59g of acetic acid was added thereto to neutralize the reaction solution, 340g of chlorodimethylvinylsilane was added thereto, and the mixture was stirred at 60 ℃ for 8 hours. The resulting product was filtered, washed with water, azeotropically dehydrated, and distilled off under reduced pressure, whereby the following branched silicone oil was synthesized. It was found that the Mw was 81000 and the Vi value was 2.47 × 10^-3mol/100g of²⁹The Si NMR spectrum yields organopolysiloxanes with a-80, b-12, and c-12.

Comparative example 1

（A-1’）

Both terminal vinylphenyl methyl silicone oil of the formula (Vi 3.81X 10, manufactured by shin-Etsu chemical Co., Ltd.)^-2mol/100g）。

Comparative example 2

（A-2’）

Both terminal vinyl dimethylsilicone fluids of the formula (Vi 1.33X 10, manufactured by shin-Etsu chemical Co., Ltd.)^-2mol/100g）

n is 200 (average).

Comparative example 3

（A-3’）

63.7g of 1, 1-diphenyl-1, 3-dimethyl-3, 3-dimethoxy disiloxane and polymethylphenylsiloxane-alpha, omega-diol (Mw is 5)30) 1200g of dimethylvinylmethoxysilane and 48.8g of dimethylvinylmethoxysilane were stirred and adjusted to 60 ℃. Then, Sr (OH) is added₂・8H₂O3.15 g, and the reaction was carried out at 60 ℃ for 3 hours. The catalyst was removed from the resultant product by filtration, and methanol and water were distilled off under reduced pressure, whereby the following branched silicone oil was synthesized. It can be seen that the Mw is 5700 and the Vi value is 3.51 × 10^-2mol/100g of²⁹The Si-NMR spectrum gave an organopolysiloxane with n-37 and m-1.

(B) Component (C), component (D), and

hereinafter, the component (B), the component (C) and the component (D) used in examples are shown.

(B-1) phenyl Silicone resin of the formula (Vi 0.147mol/100g, product of shin-Etsu chemical Co., Ltd.)

n is 3, m is 10, and molecular weight is 1600.

(B-2) a methyl silicone resin represented by the following formula (Vi 9.12X 10, manufactured by shin-Etsu chemical Co., Ltd.)^-2mol/100g）

n is 5, m is 30, j is 48, molecular weight is 5800.

(C-1) A silicone oil having hydrosilyl groups at both terminals, represented by the following formula (SiH 0.600mol/100g, manufactured by shin-Etsu chemical Co., Ltd.).

(C-2) Silicone oil having a hydrosilyl group in a side chain, represented by the formula (SiH 1.63mol/100g, manufactured by shin-Etsu chemical Co., Ltd.)

n is the average 38.

(D) Isododecane solution of divinyl siloxane complex of chloroplatinic acid (platinum content 0.5 mass%)

[ example 1]

100 parts by mass of (A-1), 300 parts by mass of (B-1), and 81 parts by mass of (C-1) were mixed, and a divinylsiloxane complex of chloroplatinic acid in an amount of 5ppm as platinum was added thereto and mixed to prepare a curable composition.

Examples 2 to 4 and comparative examples 1 to 3

A curable composition was prepared by repeating the same operation as in example 1, except that the blending amount of each component was changed as shown in table 1.

The following tests were carried out on the curable compositions prepared in examples 1 to 4 and comparative examples 1 to 3.

[ viscosity of curable composition ]

According to JIS Z8803: 2011, the viscosity of the curable composition at 23 ℃ was measured using a B-type viscometer. The results are set forth in Table 1.

[ hardness of cured product ]

The obtained curable composition was poured into an aluminum pan having a diameter of 50mm × 10mm and gradually cured at 60 ℃ × 1 hour, 100 ℃ × 1 hour, and 150 ℃ × 4 hours in this order to obtain a cured product. According to JIS K6253-3: 2012 the hardness (durometer ShoreA or ShoreD) of the cured product. The results are set forth in Table 1.

[ light transmittance of cured product ]

A concave 1mm thick テフロン (Teflon) slide was clamped between 2 50mm by 20mm by 1mm thick slides

) (registered trademark) spacers, after these were fixed, a curable composition was poured into the spacers, and the spacers were gradually cured at 60 ℃ for 1 hour, at 100 ℃ for 1 hour, and at 150 ℃ for 4 hours to prepare samples for transmittance measurement. The light transmittance at 450nm of the obtained sample was measured by a spectrophotometer U-4100 (manufactured by Hitachi ハイテクノロジーズ Co., Ltd.). The results are set forth in Table 1.

[ tensile Strength and elongation at Break of cured product ]

The prepared curable composition was poured into a concave テフロン (registered trademark) metal mold having a thickness of 150mm × 200mm × 2mm, and gradually cured at 60 ℃ × 1 hour, 100 ℃ × 1 hour, and 150 ℃ × 4 hours in this order to prepare a sample. According to JIS K6251: 2010, the tensile strength and the elongation at break (the moment of buckle at break) of the sample were measured at a TEST speed of 500mm/min, an inter-holder distance of 80mm, and a gauge inter-punctuation distance of 40mm using an EZ TEST (EZ-L, manufactured by Shimadzu corporation).

The results are set forth in Table 1.

[ glass transition temperature of cured product ]

The storage elastic modulus (MPa) of the cured product sample prepared as described in [ tensile strength and elongation at break of cured product ] above was measured in the range of-140 to 150 ℃ using DMA Q800 (manufactured by TA インスツルメント), the value of Tan δ derived from the obtained values of storage elastic modulus and loss elastic modulus was plotted to obtain a graph, and the temperature of the peak top obtained from the graph was defined as the glass transition temperature (Tg).

The measurement conditions were 20mm long × 5mm wide × 1mm thick samples, temperature rise rate 5 ℃/min, multi-frequency mode (マルチ cycles モード), tensile mode, and amplitude 15 μm. The results are set forth in Table 1. The storage elastic modulus and Tan δ of the cured products of example 1 (solid line) and comparative example 1 (broken line) were plotted. FIG. 1 shows a graph of storage elastic modulus and a graph of Tan. delta. of cured products of example 1 (solid line) and comparative example 1 (broken line).

[ temperature cycle test ]

A curable composition was dispensed onto a Tiger3528 package (パッケージ) (manufactured by shin-Etsu chemical Co., Ltd.), and the composition was gradually cured at 60 ℃ for 1 hour, at 100 ℃ for 1 hour, and at 150 ℃ for 4 hours, to prepare a test article in which the package was sealed with a cured product. For 20 of the test pieces, a Thermal Cycle Test (TCT) was performed at-50 ℃ to 140 ℃ for 1000 times, and the number of test pieces having cracks on the package was measured. The results are set forth in Table 1.

[ TABLE 1]

H/Vi ═ (mol of SiH group in the composition)/(mol of Vi group in the composition)

NG is the number of test pieces that have cracked on the encapsulant.

As shown in table 1, the curable silicone resin composition using the branched organopolysiloxane of the present invention formed a cured product having a lower glass transition temperature and superior crack resistance than the composition using a linear organopolysiloxane instead of the component (a) of the present invention. In addition, the viscosity of the resin composition is sufficiently low, and the work efficiency is good.

Industrial applicability

The invention provides an addition curing type organic silicon composition which has good low-temperature characteristics and can form a cured product with excellent temperature change resistance, and a semiconductor device which is packaged with a semiconductor element by using the cured product of the composition and has high reliability.

Claims

1. An addition-curable silicone resin composition comprising

(A) A branched organopolysiloxane represented by the following formula (1)

In the formula (1), R¹Independently of each other, a group selected from a substituted or unsubstituted saturated hydrocarbon group having 1 to 12 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, R²Independently represents a group selected from a C1-12 substituted or unsubstituted saturated hydrocarbon group, a C6-12 substituted or unsubstituted aromatic hydrocarbon group, and a C2-10 alkenyl group, and each R¹、R²May be the same or different, wherein R is²At least 2 of the above groups are alkenyl groups, a is an integer of 2 to 100, b is an integer of 5 to 100, c is an integer of 5 to 100, a/(a + b) < 1.0 and 0.03 ≤ and (R)¹ ₂R²SiO_1/2) Number of units/(R)²SiO_3/2) The number of units is less than or equal to 2, the arrangement of the siloxane chains of a, b and c can be random or block,

in the formula (1), R¹At least 1 of the aromatic hydrocarbon groups is an aromatic hydrocarbon group having 6 to 12 carbon atoms, and the proportion of the number of 1-valent aromatic hydrocarbon groups in the total number of substituents bonded to silicon atoms is 3% or more and 90% or less,

(B) a silicone resin represented by the following formula (2)

(R² ₃SiO_1/2)_r(R² ₂SiO_2/2)_s(R²SiO_3/2)_t(SiO_4/2)_u (2)

In the formula (2), R²Is as defined above, R²At least 2 of the above groups are alkenyl groups, r is an integer of 0 to 100, s is an integer of 0 to 300, t is an integer of 0 to 200, u is an integer of 0 to 200, t + u is not less than 1 and not more than 400, r + s + t + u is not less than 2 and not more than 800,

(C) An organopolysiloxane having at least 2 hydrosilyl groups in the molecule, and

(D) a hydrosilylation catalyst, which is a mixture of a hydrosilylation catalyst,

the amount of the component (B) is 20 to 900 parts by mass per 100 parts by mass of the component (A), the amount of the component (C) is such that the number of hydrosilyl groups in the component (C) is 0.4 to 4.0 relative to the total number of alkenyl groups in the components (A) and (B), and the amount of the component (D) is sufficient for the hydrosilylation reaction to proceed.

2. The addition-curable silicone resin composition according to claim 1, wherein, in formula (1), 0.09. ltoreq. a/(a + b). ltoreq.0.9.

3. The addition-curable silicone resin composition according to claim 1 or 2, wherein component (C) is a component represented by the following formula (3),

(R³ ₃SiO_1/2)_r’(R³ ₂SiO_2/2)_s’(R³SiO_3/2)_t’(SiO_4/2)_u’ (3)

in the formula (3), R³Independently of each other, a hydrogen atom, a substituted or unsubstituted saturated hydrocarbon group having 1 to 12 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, and R³At least 2 of the groups are hydrogen atoms, r 'is an integer of 0 to 100, s' is an integer of 0 to 300, t 'is an integer of 0 to 200, u' is an integer of 0 to 200, and 2 is not more than r '+ s' + t '+ u' + 800.

4. A semiconductor device, wherein a semiconductor element is encapsulated with a cured product of the addition curable silicone resin composition according to any one of claims 1 to 3.

5. The semiconductor device according to claim 4, wherein the semiconductor element is a light-emitting element.

6. A process for producing an addition-curable silicone resin composition, which comprises mixing the following component (A), component (B), component (C) and component (D),

(A) the components: a reaction product produced by co-condensing an organopolysiloxane represented by the following formula (4) with an organopolysiloxane represented by the following formula (5) having alkoxysilyl groups or hydroxysilyl groups, i.e., silanol groups, at both ends and then end-capping the ends with a hydrolyzable group-containing silane compound represented by the following formula (6),

in the formula (4), R¹Independently of each other, a group selected from a substituted or unsubstituted saturated hydrocarbon group having 1 to 12 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, R²Independently represents a group selected from a C1-12 substituted or unsubstituted saturated hydrocarbon group, a C6-12 substituted or unsubstituted aromatic hydrocarbon group, and a C2-10 alkenyl group, and each R¹、R²May be the same or different, wherein R is²At least 2 of the above groups are alkenyl groups, c is an integer of 5 to 100, R³Is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms,

in the formula (5), R²、R³B' is an integer of 1 to b, b is an integer of 5 to 100,

in the formula (6), R¹、R²X is a halogen atom or R³A group represented by O-, wherein R³The same as above;

(B) the components: an organopolysiloxane represented by the following formula (2)

(R² ₃SiO_1/2)_r(R² ₂SiO_2/2)_s(R²SiO_3/2)_t(SiO_4/2)_u (2)

In the formula (2), R²Is as defined above, R²At least 2 of the above groups are alkenyl groups, r is an integer of 0 to 100, and s is 0300, t is an integer of 0 to 200, u is an integer of 0 to 200, t + u is more than or equal to 1 and less than or equal to 400, r + s + t + u is more than or equal to 2 and less than or equal to 800,

(C) the components: an organopolysiloxane having at least 2 hydrosilyl groups in a molecule,

(D) the components: a hydrosilylation catalyst, which is a mixture of a hydrosilylation catalyst,

7. The method for producing an addition-curable silicone resin composition according to claim 6, wherein the proportion of the number of 1-valent aromatic hydrocarbon groups in the total number of substituents bonded to silicon atoms in the reaction product (A) is 3% or more and 90% or less.

8. The method for producing an addition-curable silicone resin composition according to any one of claims 6 to 7, wherein component (C) is a component represented by the following formula (3),

(R³ ₃SiO_1/2)_r’(R³ ₂SiO_2/2)_s’(R³SiO_3/2)_t’(SiO_4/2)_u’ (3)

9. The addition-curable silicone resin composition according to claim 1, wherein the branched organopolysiloxane has alkenyl groups only at both ends of a siloxane main chain.