Addition reaction-curable silicone resin composition, and die attach material for semiconductor device

Abstract

To obtain an addition reaction-curable silicone resin composition excellent in resin strength of a cured product, satisfying both heat conductivity and low elasticity, and excellent in adhesive strength with a substrate.SOLUTION: An addition reaction-curable silicone resin composition includes the following constituents (A)-(D), where a cured product of the composition has a heat conductivity of 1.0 W / mK or higher, and a storage elastic modulus at -40°C of 250 MPa or lower. The constituent (A) is composed of a constituent (A-1) being a branched organopolysiloxane, and a constituent (A-2) being a straight chain organopolysiloxane; the constituent (B) is composed of a straight chain organopolysiloxane; the constituent (C) is composed of an addition reaction-curing catalyst; and the constituent (D) is composed of a constituent (D-1) and a constituent (D-2) being a heat conductive filler.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an addition-curable silicone resin composition and a die attach material for semiconductor device using said composition. [Background technology]

[0002] Addition-curable silicone resins as die-attach materials in the electronic materials field have been attracting attention in recent years because they have many advantages over conventional organic polymer resins, such as high reliability in terms of moisture resistance and heat resistance, high stress relaxation ability due to the ability to reduce elasticity, and easy handling.

[0003] Die attach materials for sensors used when mounting various sensors on a substrate are required to have properties that make it difficult for shocks from the substrate to be transmitted to the chip and to be able to relax stress over a wide operating temperature range. Methylphenyl silicone resins, which have a small amount of phenyl groups, have a glass transition temperature of -50°C or lower and become gel-like or rubber-like when cured. This silicone resin is known to have very little change in storage modulus over a wide temperature range, making it preferable for use as a die attach material for the above-mentioned sensors in terms of properties.

[0004] In recent years, due to the increase in heat generation caused by the enlargement of chips, especially in CMOS image sensors, thermal conductivity is also required for die attachment materials. When thermal conductivity is imparted to die attachment materials, it is common to highly fill silicone resin with thermally conductive fillers. However, there is a concern that the storage modulus of the cured material will increase, causing greater warping of the sensor chip (Patent Document 1). In particular, there is a concern that materials containing a large amount of thermally conductive fillers with high Mohs hardness may wear down the metal nozzle during dispense application or damage the back surface of the chip during die bonding.

[0005] On the other hand, in the case of a silicone resin composition that hardens into a gel with a low elastic modulus, the elastic modulus can be reduced even if a high amount of thermally conductive filler is added, but in that case, there is a concern that the strength for holding the sensor chip may be reduced (Patent Document 2).

[0006] Furthermore, it is known that silicone resins containing a large amount of highly volatile low-molecular-weight siloxane compounds with a degree of polymerization of 10 or less cause various problems when used as a die-attach material for sensors. In particular, in CMOS image sensors, low-molecular-weight siloxane compounds volatilized during a process that involves heat history may adhere to the on-chip lens on the top surface of the chip. If this happens, it is highly likely that the incident light will be hindered from reaching the color filter during the operation of the completed package, causing malfunction. Therefore, it is required that the content of low-molecular-weight siloxanes with a degree of polymerization of 10 or less in the entire resin is low. In addition, it is known that, as a die-attach material for LEDs, by using a silicone resin composition with a predetermined or less content of low-molecular-weight siloxanes having hydrosilyl groups, contamination of the gold pad electrode part on the surface of the LED element caused by adhesions that may occur during heat curing of the die-attach material, can be suppressed, but this is insufficient as a die-attach material for sensors (Patent Document 3).

[0007] In addition, it is known that silicone resin compositions using organopolysiloxanes with specific structures give cured products with high hardness and resin strength. However, when used as die attachment materials for sensors with large chip sizes, there is a concern that the stress on the chip may become high (Patent Document 4).

[0008] As described above, when conventional addition-curable silicone resin compositions are used as die attach materials for semiconductors, it is difficult to achieve both high thermal conductivity and low elasticity while still achieving high resin strength in the cured product. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2015-093970 A [Patent Document 2] JP 2013-124257 A [Patent Document 3] Patent Publication No. 2021-038309

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0010] The present invention has been made to solve the above problems, and provides an addition-curable silicone resin composition having excellent resin strength of the cured product, compatible with both thermal conductivity and low elastic modulus, and excellent adhesion to a substrate.

Means for Solving the Problems

[0011] In order to solve the above problems, the present invention provides an addition-curable silicone resin composition containing the following components (A) to (D), wherein the cured product of the composition has a thermal conductivity of 1.0 W / m·K or more and a storage elastic modulus at -40°C of 250 MPa or less: (A) An alkenyl group-containing organopolysiloxane composed of the following components (A-1) and (A-2): (A-1) The following formula (1) (R (R 1 1R 2 2SiO 1 / 2 ) a (R 2 3SiO 1 / 2 ) b (R 2 2SiO 2 / 2 ) c (R 2 SiO 3 / 2 ) d (SiO 4 / 2 ) e (1) (In the formula, R 1 is an alkenyl group having 2 to 8 carbon atoms, R 2 is independently an alkyl group having 1 to 12 carbon atoms, 0.01 < a < 0.15, 0.3 < b < 0.6, 0 ≤ c, 0 ≤ d, 0.25 < e < 0.67, provided that a + b + c + d + e = 1. and a branched organopolysiloxane having two or more alkenyl groups having 2 to 8 carbon atoms in one molecule, (A-2) The following formula (2) (R 1 R 2 2SiO 1 / 2 )2(R 2 2SiO 2 / 2 ) x (R 3 2SiO 2 / 2 ) y (2) (In the formula, R 1 and R 2 are the same as above, and R 3 are each independently an aryl group having 6 to 12 carbon atoms, and x and y are numbers such that x>0, y≧0, 0.85≦(x / (x+y)), and 50≦x+y≦5,000. A linear organopolysiloxane represented by the formula: (B) The following formula (3) (R 2 3SiO 1 / 2 )2(HR 2 SiO 2 / 2 ) j (R 2 2SiO 2 / 2 ) k (3) (In the formula, R 2 are the same as above, and j and k are positive numbers satisfying 0.60≦(j / (j+k))≦0.95, and 30≦j+k≦120, wherein the content of hydrosilyl group-containing organosilicon compounds having 1 to 10 silicon atoms is 5 mass% or less, (C) an addition cure catalyst, and (D) A thermally conductive filler consisting of the following components (D-1) and (D-2): (D-1) a thermally conductive filler having a Mohs hardness of 5 or more and an average particle size (D50) of 0.1 to 10 μm; (D-2) A thermally conductive filler having a Mohs hardness of less than 5 and an average particle size (D50) of 10 to 50 μm (wherein, (D-1):(D-2)=20:80 to 80:20 (mass ratio)) to provide.

[0012] With such an addition-curable silicone resin composition of the present invention, it is possible to obtain an addition-curable silicone resin composition that has excellent resin strength, and is compatible with thermal conductivity and low elasticity, as well as excellent adhesion to substrates.

[0013] In the addition-curable silicone resin composition of the present invention, the content of the above-mentioned component (D) is preferably 65 to 90 mass % of the total composition.

[0014] The addition-curable silicone resin composition of the present invention provides a cured product that has a low storage modulus and exhibits high cured strength and thermal conductivity.

[0015] In the addition-curable silicone resin composition of the present invention, the component (D-1) is preferably spherical aluminum oxide particles.

[0016] When the addition-curable silicone resin composition of the present invention is combined with component (D-2), it is possible to obtain a silicone resin composition that provides a cured product with high resin strength and thermal conductivity.

[0017] In the addition-curable silicone resin composition of the present invention, the above-mentioned component (D-2) is preferably spherical aluminum particles.

[0018] When such an addition-curable silicone resin composition of the present invention is combined with component (D-1), the resulting cured product has high thermal conductivity and a low storage modulus at -40°C, and is less likely to damage the surrounding area during the mounting process.

[0019] Furthermore, the addition-curable silicone resin composition of the present invention contains, as an adhesive aid (E), a compound represented by the following formula (4): (MeSiO 3 / 2 ) p1 (EpSiO 3 / 2) p2 (EpMeSiO 2 / 2 ) q1 (Me2SiO 2 / 2 ) q2 (ViMeSiO 2 / 2 ) q3 (OR 5 ) r (4) (In the formula, Me is a methyl group, Ep is a monovalent organic group having an epoxy group, Vi is a vinyl group, and R 5 is an alkyl group having 1 to 12 carbon atoms, 0 ≦ p1 < 0.35, 0 ≦ p2 < 0.35, 0 ≦ q1 < 0.35, 0.4 ≦ q2 < 0.7, 0 < q3 < 0.1, 0 ≦ r < 0.05, and 0.15 ≦ (p2 + q1) / (p1 + p2 + q1 + q2 + q3 + r) ≦ 0.35, provided that p1 + p2 + q1 + q2 + q3 + r = 1.) It preferably contains a branched organopolysiloxane represented by , having a weight average molecular weight of 1,500 to 8,000 and an epoxy equivalent of 250 to 500 g / eq.)

[0020] For an addition-curable silicone resin composition containing such an adhesion promoter as component (E), an addition-curable silicone resin cured product excellent in adhesion to various substrates including an organic substrate can be obtained.)

[0021] Further, in the addition-curable silicone resin composition of the present invention, the amount of a low molecular weight siloxane compound having a degree of polymerization of 10 or less in the entire addition-curable silicone resin composition is preferably 1% by mass or less.)

[0022] For such an addition-curable silicone resin composition, there is little adhesion of contaminants to peripheral members during curing, and defects in customer processes can be suppressed.)

[0023] Furthermore, the present invention provides a die attach material for a semiconductor device made of the addition-curable silicone resin composition of the present invention.)

[0024] Such a die attach material for semiconductor device provides a highly reliable semiconductor device because it achieves both thermal conductivity and low elasticity while maintaining high resin strength after curing. Effect of the Invention

[0025] According to the addition-curable silicone resin composition of the present invention, when used as a die-attach material for semiconductor device, it is possible to provide an addition-curable silicone resin composition that has excellent resin strength in the cured product, and that has both excellent thermal conductivity and low elasticity, as well as excellent adhesion. For this reason, the addition-curable silicone resin composition of the present invention is extremely useful as a die-attach material for semiconductor device.

[0026] The reason why such effects are exhibited is believed to be that, by using the specific organopolysiloxanes in a specific combination, both thermal conductivity and low elasticity are achieved while the resin strength of the cured product is excellent, as compared to addition-curable silicone resin compositions that contain ordinary thermally conductive fillers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] As described above, there has been a need for the development of an addition-curable silicone resin composition which exhibits excellent resin strength in the cured product, while also exhibiting both thermal conductivity and low elasticity, and which also exhibits excellent adhesion to substrates.

[0028] As a result of extensive investigations into the above-mentioned problems, the inventors discovered that by using specific organopolysiloxanes in specific combinations, it is possible to achieve both thermal conductivity and low elasticity while maintaining excellent resin strength in the cured product, as compared to addition-curable silicone resin compositions containing ordinary thermally conductive fillers, and thus completed the present invention.

[0029] That is, the present invention provides: The present invention relates to an addition-curable silicone resin composition having a thermal conductivity of 1.0 W / m K or more and a storage modulus of 250 MPa or less at -40°C after curing, the composition comprising the following components (A) to (D): (A) An alkenyl group-containing organopolysiloxane composed of the following components (A-1) and (A-2): (A-1) The following formula (1) (R 1 1R 2 2SiO 1 / 2 ) a (R 2 3SiO 1 / 2 ) b (R 2 2SiO 2 / 2 ) c (R 2 SiO 3 / 2 ) d (SiO 4 / 2 ) e (1) (In the formula, R 1 is an alkenyl group having 2 to 8 carbon atoms, R 2 is independently an alkyl group having 1 to 12 carbon atoms, 0.01 < a < 0.15, 0.3 < b < 0.6, 0 ≤ c, 0 ≤ d, 0.25 < e < 0.67, provided that a + b + c + d + e = 1 is satisfied.) and is a branched organopolysiloxane having two or more alkenyl groups having 2 to 8 carbon atoms in one molecule, (A-2) The following formula (2) (R 1 R 2 2SiO 1 / 2 )2(R 2 2SiO 2 / 2 ) x (R 3 2SiO 2 / 2 ) y (2) (In the formula, R 1 and R 2 are the same as above respectively, R 3 is independently an aryl group having 6 to 12 carbon atoms, x and y are x > 0, y ≥ 0, 0.85 ≤ (x / (x + y)), and 50 ≤ x + y ≤ 5,000.) and is a linear organopolysiloxane represented by (B) The following formula (3) (R 2 3SiO 1 / 2 )2(HR 2 SiO2 / 2 ) j (R 2 2SiO 2 / 2 ) k (3) (In the formula, R 2 are the same as above, and j and k are positive numbers satisfying 0.60≦(j / (j+k))≦0.95, and 30≦j+k≦120, wherein the content of hydrosilyl group-containing organosilicon compounds having 1 to 10 silicon atoms is 5 mass% or less, (C) an addition cure catalyst, and (D) A thermally conductive filler consisting of the following components (D-1) and (D-2): (D-1) A thermally conductive filler having a thermal conductivity of 20 W / m·K or more, a Mohs hardness of 5 or more, and an average particle size (D50) of 0.1 to 10 μm. (D-2) A thermally conductive filler having a thermal conductivity of 20 W / m·K or more, a Mohs hardness of less than 5, and an average particle size (D50) of 10 to 50 μm. (However, (D-1):(D-2) = 20:80 to 80:20 (mass ratio).

[0030] The present invention will be described in detail below, but the present invention is not limited thereto.

[0031] The addition-curable silicone resin composition of the present invention contains the above-mentioned components (A) to (D), and may further contain various known additives as necessary. Each component will be described below.

[0032] <(A) Alkenyl Group-Containing Organopolysiloxane> Component (A) is an alkenyl-containing organopolysiloxane, which is the main component of the present invention. Component (A) is also an alkenyl-containing organopolysiloxane that is a combination of the branched organopolysiloxane (A-1) and the linear organopolysiloxane (A-2) described below.

[0033] The above component (A-1) is a branched organopolysiloxane represented by the following formula (1) and having two or more alkenyl groups having 2 to 8 carbon atoms in one molecule. (R 1 1R 2 2SiO 1 / 2 ) a (R 2 3SiO 1 / 2 ) b (R 2 2SiO 2 / 2 ) c (R 2 SiO 3 / 2 ) d (SiO 4 / 2 ) e (1) (In the formula, R 1 is an alkenyl group having 2 to 8 carbon atoms, R 2 is independently an alkyl group having 1 to 12 carbon atoms, 0.01 < a < 0.15, 0.3 < b < 0.6, 0 ≤ c, 0 ≤ d, 0.25 < e < 0.67, provided that a + b + c + d + e = 1.

[0034] In the above formula (1), as the alkenyl group having 2 to 8, particularly 2 to 6 carbon atoms of R 1 , specifically, vinyl group, allyl group, isopropenyl group, butenyl group, pentenyl group, hexenyl group, cyclohexenyl group, etc. are exemplified, and a vinyl group is particularly preferable.

[0035] In the above formula (1), as the alkyl group having 1 to 12, particularly preferably 1 to 10 carbon atoms of R 2 , specifically, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, octyl group, nonyl group, decyl group, etc. can be exemplified. As the alkyl group of the above R 2 , considering the heat resistance of the silicone cured product under high temperature conditions of the silicone cured product produced from the obtained addition-curable silicone resin composition, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group are preferable, and a methyl group is particularly preferable.

[0036] In addition, R in the above formula (1) 1 1R 2 2SiO 1 / 2 The content rate a of the unit is in the range of 0.01 < a < 0.15, preferably 0.03 ≤ a ≤ 0.13, with respect to the total of the siloxane units a + b + c + d + e = 1. Also, R 2 3SiO 1 / 2 The content rate b of the unit is 0.3 < b < 0.6, preferably 0.35 ≤ b ≤ 0.5, with respect to the total of the siloxane units a + b + c + d + e = 1. Further, SiO 4 / 2 The content rate e of the unit is 0.25 < e < 0.67, preferably 0.3 ≤ e ≤ 0.6, with respect to the total of the siloxane units a + b + c + d + e = 1.

[0037] In addition, R in the above formula (1) 2 2SiO 2 / 2 The content rate c of the unit and R 2 SiO 3 / 2 The content rate d of the unit are arbitrary units, and 0 ≤ c, 0 ≤ d with respect to the total of the siloxane units a + b + c + d + e = 1, respectively. c is preferably 0, and d is preferably 0 ≤ d ≤ 0.3.

[0038] The component (A-1) can be easily synthesized by mixing the compounds serving as each unit source at a content rate within the above range and performing co-hydrolysis and condensation, for example, in the presence of an acid.

[0039] Here, the R 1 1R 2 2SiO 1 / 2 Unit sources may include organosilicon compounds such as triorganochlorosilane, triorganoalkoxysilane, and hexaorganodisiloxane represented by the following structural formulas, but the R 1 1R 2 2SiO 1 / 2 Unit sources are not limited to these.

[0040]

Chemical formula

[0041] Here, the above R 2 3SiO 1 / 2 Examples of the unit source include organosilicon compounds such as triorganochlorosilane, triorganoalkoxysilane, and hexaorganodisiloxane represented by the following structural formulas. 2 3SiO 1 / 2 The unit sources are not limited to these.

[0042] [ka]

[0043] Here, the above SiO 4 / 2 Examples of the unit source include organic silicon compounds such as tetrachlorosilane and tetraalkoxysilane represented by the following structural formula. 4 / 2 The unit sources are not limited to these.

[0044] [ka]

[0045] There are no particular limitations on the molecular weight of the component (A-1), and for example, the weight average molecular weight measured by GPC can be 1,000 to 20,000, and preferably 2,000 to 10,000. Furthermore, the component (A-1) may be either a solid or a liquid at 25°C.

[0046] The component (A-2) is represented by the following formula (2) and has two R 1 It is a linear organopolysiloxane having (an alkenyl group having 2 to 8 carbon atoms). (R 1 R 2 2SiO 1 / 2 )2(R 2 2SiO 2 / 2 ) x (R 3 2SiO 2 / 2 ) y (2) (In the formula, R 1 and R2 are the same as above, and R 3 are each independently an aryl group having 6 to 12 carbon atoms, and x and y are numbers such that x>0, y≧0, 0.85≦(x / (x+y)), and 50≦x+y≦5,000.

[0047] In the above formula (2), R 1 Specific examples of the alkenyl group having 2 to 8 carbon atoms, particularly preferably 2 to 6 carbon atoms, include a vinyl group, an allyl group, an isopropenyl group, a butenyl group, a pentenyl group, a hexenyl group, and a cyclohexenyl group, with a vinyl group being particularly preferred.

[0048] In the above formula (2), R 2 Specific examples of the alkyl group having 1 to 12 carbon atoms, particularly preferably 1 to 10 carbon atoms, include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, octyl group, nonyl group, and decyl group. 2 As the alkyl group, taking into consideration the heat resistance under high temperature conditions of the silicone cured product produced from the resulting addition-curable silicone resin composition, alkyl groups such as methyl, ethyl, propyl and isopropyl groups are preferred, with methyl groups being particularly preferred.

[0049] In the above formula (2), R 3 Specific examples of the aryl group having 6 to 12 carbon atoms include a phenyl group and a naphthyl group, and a phenyl group is particularly preferred. When using a linear organopolysiloxane having a specific amount of phenyl groups introduced in this way, the storage modulus in the low temperature range of the obtained addition-curable silicone resin cured product can be kept low.

[0050] In the above formula (2), x is x>0, preferably 85 to 3400, and y is y≧0, preferably 0 to 600, more preferably 8 to 600. Furthermore, x and y are numbers that satisfy 50≦x+y≦5,000, and preferably 100≦x+y≦4,000. Furthermore, 0.85≦(x / (x+y)), and preferably 0.90≦(x / (x+y)). Within the above ranges, the compatibility with component (A-1) and component (B) described below is good, and an addition-curable silicone resin cured product with high resin strength is obtained.

[0051] Regarding the properties of the above component (A-2), it is preferably in a liquid state at 25°C, and more preferably has a viscosity at 25°C in the range of 8 to 30,000 mPa·s, as measured with a rotational viscometer according to the method described in JIS K 7117-1:1999.

[0052] Specific examples of the component (A-2) include the following:

[0053] [ka]

[0054] The blending amount of the (A-2) component is, for example, 100 to 3,000 parts by mass, preferably 100 to 2,000 parts by mass, more preferably 100 to 1,000 parts by mass, even more preferably 150 to 950 parts by mass, and extremely preferably 200 to 900 parts by mass, per 100 parts by mass of the (A-1) component.

[0055] <(B) Linear organohydrogenpolysiloxane> The component (B) is a linear organohydrogenpolysiloxane represented by the following formula (3). (R 2 3SiO 1 / 2 )2(HR 2 SiO 2 / 2 ) j (R 2 2SiO 2 / 2 ) k (3) (In the formula, R2 are the same as above, j and k are positive numbers such that 0.60≦(j / (j+k))≦0.95, and 30≦j+k≦120.

[0056] Furthermore, the content of hydrosilyl group-containing organosilicon compound having 1 to 10 silicon atoms in component (B) is no more than 5 mass %, and preferably no more than 1 mass %.

[0057] In the present invention, the content of the organosilicon compound having 1 to 10 silicon atoms and containing a hydrosilyl group refers to the content of the siloxane compound determined by gas chromatography under the following conditions.

[0058] [Measurement conditions] Equipment: GC-2014 (Shimadzu Corporation) Column: Product name: HP-5MS (Agilent Technologies, Inc., inner diameter: 0.25 mm, length: 30 m, packing material: (5%-phenyl)-methylpolysiloxane) Detector: FID detector (detector temperature: 300℃) Sample: 1.0 g of sample was dissolved in 10 mL of n-tetradecane / acetone standard solution (concentration: 20 μg / mL) to prepare a sample. ·Injection volume: 1μL Oven temperature: 50℃-280℃ / 23 minutes-280℃ / 17 minutes Carrier gas: Type…Helium, Linear velocity…34.0cm / s

[0059] The above-mentioned component (B) acts as a crosslinking agent, and a silicone cured product is formed from the addition-curable silicone resin composition of the present invention by an addition reaction between alkenyl groups (particularly preferably vinyl groups) bonded to silicon atoms in the above-mentioned components (A-1) and (A-2) and hydrogen atoms (hydrosilyl groups) bonded to silicon atoms in component (B).

[0060] HR in the above formula (3) 2 SiO 2 / 2 Content of units (mol%) j and R2 2SiO 2 / 2 The relationship of the content (mol %) k of the unit is in the range of 0.60≦(j / (j+k))≦0.95, preferably in the range of 0.70≦(j / (j+k))≦0.90. The degree of polymerization of the formula (3) is in the range of 30≦j+k≦120, preferably in the range of 40≦j+k≦110.

[0061] In the above formula (3), R 2 are the same as above. 2 In consideration of the heat resistance of the silicone cured product produced from the resulting addition-curable silicone resin composition when left under high-temperature conditions for long periods of time, preferred alkyl groups are methyl, ethyl, propyl, isopropyl and the like, with methyl being particularly preferred.

[0062] Since such linear organohydrogenpolysiloxanes contain a large amount of siloxane units having hydrogen atoms bonded to silicon atoms on the D units, the curability can be adjusted by steric hindrance during the addition curing reaction. In addition, they have high wettability with substrates, and the hydrosilyl groups that remain without being incorporated into the addition curing reaction with alkenyl groups due to steric hindrance are converted to hydroxysilyl groups by the addition reaction catalyst, which contributes to improving the adhesion to the substrate.

[0063] Furthermore, the amount of hydrosilyl groups in the linear organohydrogenpolysiloxane of component (B) is preferably 0.7 to 1.5 mol / 100 g, and more preferably 1.0 to 1.4 mol / 100 g.

[0064] Specific examples of the linear organohydrogenpolysiloxane of component (B) include the following: [ka] (In the formula, j and k are the same as above.)

[0065] The amount of component (B) blended is preferably such that the total amount of hydrogen atoms bonded to silicon atoms in component (B) is in the range of 1.0 to 2.0 moles, and particularly preferably in the range of 1.1 to 1.5 moles, per mole of the total amount of alkenyl groups bonded to silicon atoms in the entire addition-curable silicone resin composition. When the total amount of hydrogen atoms bonded to silicon atoms in component (B) is within the above range, the curing reaction proceeds smoothly, and a silicone cured product can be obtained with high adhesion to the substrate.

[0066] <(C) Addition curing catalyst> The addition curing catalyst of component (C) is blended to promote the addition curing reaction of the addition curable silicone resin composition of the present invention, and is available in platinum, palladium, and rhodium types. From the viewpoint of cost, etc., platinum-based catalysts such as platinum and chloroplatinic acid, for example, HPtCl6·mH2O, K2PtCl6, KHPtCl6·mH2O, K2PtCl4, K2PtCl4·mH2O (m is a positive integer), and complexes of these with hydrocarbons such as olefins, alcohols, or alkenyl group-containing organopolysiloxanes can be exemplified, and these can be used alone or in combination of two or more. In addition, in the case of platinum-based catalysts, complexes in which the ligand is removed by ultraviolet light and activity is expressed can be used.

[0067] The amount of the addition curing catalyst is preferably in the range of 0.1 to 100 ppm, more preferably 1 to 50 ppm, in platinum group metal mass units, relative to 100 parts by mass of the entire addition curable silicone resin composition. If the amount of the addition curing catalyst is within the above range, the addition curable silicone resin composition has good storage properties and the addition curing reaction when heated proceeds smoothly.

[0068] <(D) Thermally conductive filler> Component (D) is a thermally conductive filler with a thermal conductivity of 20 W / m·K or greater, and is added to the addition-curable silicone resin composition of the present invention to improve its thermal conductivity.

[0069] Component (D) is a combination of the following components (D-1) and (D-2): (D-1) A thermally conductive filler having a Mohs hardness of 5 or more and an average particle size (D50) of 0.1 to 10 μm (D-2) A thermally conductive filler having a Mohs hardness of less than 5 and an average particle size (D50) of 10 to 50 μm. The addition-curable silicone resin composition of the present invention contains these in a range of (D-1):(D-2)=20:80 to 80:20 (mass ratio).

[0070] Examples of the (D-1) component include magnesium oxide particles, aluminum oxide particles, silicon carbide particles, and aluminum nitride particles, and aluminum oxide particles are preferred. The filler is preferably spherical, more preferably true spherical. The alpha content of the aluminum oxide particles is preferably 70% or more, more preferably 80% or more. When the above is combined with the (D-2) component, a silicone resin composition can be obtained that has high resin strength and high thermal conductivity in the cured product.

[0071] The above-mentioned (D-2) component includes boron nitride particles, aluminum particles, silver particles, copper particles, etc., and is preferably aluminum particles. The shape of the filler is preferably spherical, more preferably spherical. If the (D-2) component is one of these, when it is combined with the (D-1) component, it can provide a silicone resin composition that has high thermal conductivity of the cured product obtained, low storage modulus at -40°C, and low risk of damaging the surrounding area during mounting process.

[0072] The content ratio of the (D-1) component to the (D-2) component in the (D) component is in the range of (D-1):(D-2)=20:80 to 80:20 (parts by mass), and preferably in the range of (D-1):(D-2)=30:70 to 70:30 (parts by mass).

[0073] Within the above range, it is possible to provide a silicone resin composition that has high resin strength and thermal conductivity of the obtained cured product, has a low storage modulus at -40°C, and is less likely to damage the surrounding area during the mounting process. In addition, by blending thermally conductive fillers with different Mohs hardnesses and average particle sizes in the above blending ratio, a silicone resin composition with excellent storage stability can be obtained.

[0074] The particle size of the thermally conductive filler can be selected depending on the film thickness when mounted for the intended purpose. In the present invention, the average particle size (D50) refers to the median diameter based on the volume measured by a laser diffraction method.

[0075] The amount of the thermally conductive filler is preferably in the range of 65 to 90 mass%, more preferably 70 to 85 mass%, relative to 100 mass% of the total addition-curable silicone resin composition. When the amount of the thermally conductive filler is within the above range, the cured product obtained from the addition-curable silicone resin composition has a low storage modulus and exhibits high cured strength and thermal conductivity.

[0076] <(E) Adhesive aid> In addition to the above components (A) to (D), an adhesion promoter may also be added to the addition-curable silicone resin composition of the present invention.

[0077] The adhesion aid of component (E) is blended to more preferably exhibit adhesion to a substrate when the addition-curable silicone resin composition of the present invention is cured, and is preferably a branched organopolysiloxane represented by the following formula (4), which is a branched organopolysiloxane having a weight average molecular weight of 1,500 to 8,000 and an epoxy equivalent of 250 to 500 g / eq. (MeSiO 3 / 2 ) p1 (EpSiO 3 / 2 ) p2 (EpMeSiO 2 / 2 ) q1 (MeSiO 2 / 2 ) q2 (ViMeSiO 2 / 2 ) q3 (OR5 ) r (4) (In the formula, Me is a methyl group, Ep is a monovalent organic group having an epoxy group, Vi is a vinyl group, and R 5 is an alkyl group having 1 to 12 carbon atoms. For the molar fractions (contents) p1 to r of the repeating units, 0 ≦ p1 < 0.35, 0 ≦ p2 < 0.35, 0 ≦ q1 < 0.35, 0.4 ≦ q2 < 0.7, 0 < q3 < 0.1, 0 ≦ r < 0.05, and 0.15 ≦ (p2 + q1) / (p1 + p2 + q1 + q2 + q3 + r) ≦ 0.35, provided that p1 + p2 + q1 + q2 + q3 + r = 1.)

[0078] In the above formula (4), specific examples of the monovalent organic group having an epoxy group represented by Ep include organic groups such as 3-glycidoxypropyl group, 2-(3,4-epoxycyclohexyl)ethyl group, 5,6-epoxyhexyl group, and 7,8-epoxyoctyl group. Particularly, from the viewpoint of storage stability in the state of being blended in the addition-curable silicone resin composition, the 3-glycidoxypropyl group is preferable as Ep. Also, as for the alkyl group having 1 to 12 carbon atoms of R 5 , the methyl group is particularly preferable.)

[0079] Thus, the branched organopolysiloxane having a large weight-average molecular weight and a small epoxy equivalent has a large polarity difference from the component (A-1) or (A-2), and thus easily migrates to the interface with the substrate during curing, so that good adhesiveness can be exhibited. Also, since it has a vinyl group on the D unit, it is incorporated into the addition-curable silicone resin composition by an addition-curing reaction, so that bleed-out after curing can be suppressed. Furthermore, compared with those having a vinyl group on the M unit, since it is incorporated mildly into the composition, sufficient room for compatibility with the substrate can be provided.)

[0080] Also, the above content ratio p1 of the MeSiO 3 / 2 unit in the above formula (4) is in the range of 0 ≦ p1 < 0.35 with respect to the total of the siloxane units p1 + p2 + q1 + q2 + q3 + r = 1, and particularly preferably in the range of 0 ≦ p1 ≦ 0.3. Also, EpSiO3 / 2 The above content fraction p2 of the unit ranges from 0 ≦ p2 < 0.35, particularly preferably from 0 ≦ p2 ≦ 0.3, with respect to the total of the siloxane units p1 + p2 + q1 + q2 + q3 + r = 1. Further, EpMeSiO 2 / 2 The above content fraction q1 of the unit ranges from 0 ≦ q1 < 0.35, particularly preferably from 0 ≦ q1 ≦ 0.3, with respect to the total of the siloxane units p1 + p2 + q1 + q2 + q3 + r = 1. Furthermore, Me2SiO 2 / 2 The above content fraction q2 of the unit is 0.4 ≦ q2 < 0.7, particularly preferably in the range of 0.45 ≦ q2 ≦ 0.65, with respect to the total of the siloxane units p1 + p2 + q1 + q2 + q3 + r = 1. Furthermore, ViMeSiO 2 / 2 The above content fraction q3 of the unit is 0 < q3 < 0.1, particularly preferably in the range of 0 < q3 ≦ 0.08, with respect to the total of the siloxane units p1 + p2 + q1 + q2 + q3 + r = 1. Further, OR 5 The above content fraction r of the unit is 0 ≦ r < 0.05, particularly preferably in the range of 0 ≦ r ≦ 0.03, with respect to the total of the siloxane units p1 + p2 + q1 + q2 + q3 + r = 1. Also, 0.15 ≦ (p2 + q1) / (p1 + p2 + q1 + q2 + q3 + r) ≦ 0.35.

[0081] Also, the weight average molecular weight of the branched organopolysiloxane of the above formula (4) is in the range of 1,500 to 8,000, preferably in the range of 2,000 to 7,500. If the weight average molecular weight is 8,000 or less, the appearance of the silicone resin cured product is unlikely to become cloudy, and if the weight average molecular weight is 1,500 or more, sufficient adhesiveness to the substrate can be obtained. The weight average molecular weight Mw mentioned in the present invention refers to the weight average molecular weight using polystyrene as a standard substance by gel permeation chromatography (GPC) measured under the following conditions.

[0082] [Measurement conditions] · Developing solvent: Tetrahydrofuran (THF) · Flow rate: 0.6 mL / min · Detector: Differential refractive index detector (RI) Column: TSK Guardcolumn SuperH-L ·TSKgel SuperH4000(6.0mmI.D.×15cm×1) ·TSKgel SuperH3000(6.0mmI.D.×15cm×1) ·TSKgel SuperH2000(6.0mmI.D.×15cm×2) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 20 μL (0.5% by mass in THF solution)

[0083] Furthermore, the epoxy equivalent of the branched organopolysiloxane of the above formula (4) is in the range of 250 to 500 g / eq, preferably 300 to 450 g / eq. If the epoxy equivalent is 500 g / eq or less, sufficient adhesion to the substrate can be obtained, and if the epoxy equivalent is 250 g / eq or more, there is no risk of separation from the silicone resin composition.

[0084] The component (E) can be easily synthesized by mixing the compounds serving as the source units in the above-mentioned ranges of content and carrying out co-hydrolysis and condensation in the presence of a base, for example.

[0085] Here, the above EpSiO 3 / 2 Unit source and EpMeSiO 2 / 2 Examples of unit sources include organosilicon compounds represented by the following structural formulas. 3 / 2 Unit source and EpMeSiO 2 / 2 The unit sources are not limited to these.

[0086] [ka]

[0087] The amount of component (E) is preferably within the range of 0.1 to 10 parts by mass, and particularly preferably 0.2 to 5 parts by mass, per 100 parts by mass of the total addition-curable silicone resin composition. If the amount of component (E) is 0.2 parts by mass or more, excellent adhesion to the substrate is achieved, and if it is 5 parts by mass or less, it can be used without problems in coating workability, and this is preferred.

[0088] <Cure inhibitor> The addition curable silicone resin composition of the present invention may contain a cure inhibitor for the purpose of adjusting the cure rate, etc. Examples of cure inhibitors include vinyl group-containing organopolysiloxanes such as tetramethyltetravinylcyclotetrasiloxane, hexavinyldisiloxane, and 1,3-divinyltetramethyldisiloxane, acetylene alcohols such as ethynylcyclohexanol and 3-methyl-1-butyn-3-ol, and silane- or siloxane-modified versions thereof, hydroperoxides, tetramethylethylenediamine, benzotriazole, triallyl isocyanurate, alkyl maleates, and mixtures thereof.

[0089] When a curing inhibitor is added, it can be added in an amount of preferably 0.001 to 1.0 part by mass, and particularly preferably 0.005 to 0.5 part by mass, per 100 parts by mass of the total silicone resin composition.

[0090] <Low molecular weight siloxane compound> In the addition-curable silicone resin composition of the present invention, the amount of low molecular weight siloxane compounds with a degree of polymerization of 10 or less in the entire resin composition is preferably 1% by mass or less, and more preferably 0.5% by mass or less. If the amount of low molecular weight siloxane compounds with a degree of polymerization of 10 or less is the above amount or less, it is possible to provide a semiconductor package that causes little contamination of surrounding components and does not impair operation.

[0091] The content of low molecular weight siloxane compounds having a degree of polymerization of 10 or less referred to in the present invention refers to the content of siloxane compounds quantified by gas chromatography measured under the following conditions.

[0092] [Measurement conditions] Equipment: GC-2014 (Shimadzu Corporation) Column: Product name: HP-5MS (Agilent Technologies, Inc., inner diameter: 0.25 mm, length: 30 m, packing material: (5%-phenyl)-methylpolysiloxane) Detector: FID detector (detector temperature: 300℃) Sample: 1.0 g of sample was dissolved in 10 mL of n-tetradecane / acetone standard solution (concentration: 20 μg / mL) to prepare a sample. ·Injection volume: 1μL Oven temperature: 50℃-280℃ / 23 minutes-280℃ / 17 minutes Carrier gas: Type…Helium, Linear velocity…34.0cm / s

[0093] <Thermal conductivity> The addition-curable silicone resin composition of the present invention has a thermal conductivity of at least 1.0 W / m·K after curing, and preferably in the range of 1.5 to 3.0 W / m·K. If the thermal conductivity of the cured resin after curing is at least 1.0 W / m·K, when the composition is used as a semiconductor die attach agent, it can sufficiently dissipate heat generated by the semiconductor chip, thereby reducing power consumption in the semiconductor package and preventing breakdowns.

[0094] In the present invention, the thermal conductivity of the cured product of the addition-curable silicone resin composition can be a value obtained using a resin material thermal resistance measuring device (manufactured by Hitachi Technology & Services), which uses a steady-state measurement principle.

[0095] <Storage modulus at -40℃> In the addition-curable silicone resin composition of the present invention, the storage modulus of the cured resin at −40° C. is 250 MPa or less, and preferably in the range of 50 to 200 MPa. If the storage modulus of the cured resin at −40° C. is 250 MPa or less, warping of the semiconductor package in the operating temperature range is reduced, and operational defects can be suppressed.

[0096] In the present invention, the storage modulus at −40° C. of the cured product of the addition-curable silicone resin composition can be a value measured under the following conditions using a dynamic viscoelasticity measuring device (DMA) “Q800” manufactured by TA Instruments Japan, Inc. [Measurement conditions] Sample size: 20mm (length when clamped in the jig) x 5mm x 2mm (t) Temperature profile: Hold at -65°C for 5 min, then increase temperature to 300°C at 5°C / min. Frequency: 1Hz

[0097] The addition-curable silicone resin composition of the present invention can be applied onto a substrate and then cured according to the application, and can be heat-cured at a temperature of preferably 70 to 130° C., more preferably 90 to 120° C. If the heating temperature is within the above range, the adhesive strength between the substrate and the cured resin is improved, and it is possible to provide a semiconductor package with less warping, which is preferable. The heat-curing time may be 0.5 to 2.5 hours, and a step-curing method may be adopted.

[0098] The addition-curable silicone resin composition of the present invention uses the specific organopolysiloxanes in a specific combination, and thus an addition-curable silicone resin composition having superior resin strength compared to ordinary addition-curable silicone resin compositions can be obtained, which makes it suitable for use in electrical and electronic components, and more specifically, it can be used as a die attach material for semiconductor devices. EXAMPLES

[0099] The present invention will be specifically described below using examples and comparative examples, but the present invention is not limited to these.

[0100] In addition, "parts" refers to "parts by mass", Me refers to "methyl group", Vi refers to "vinyl group", and Ep' refers to "γ-glycidoxypropyl group". Furthermore, the weight average molecular weight refers to the weight average molecular weight measured by GPC under the above-mentioned conditions. In the following examples, the amount of SiH groups refers to the number of moles of hydrogen atoms directly bonded to silicon atoms in a molecule, and is measured by a Bruker Nuclear Magnetic Resonance (NMR) measurement device. 1 The value was quantified by H-NMR measurement using dimethyl sulfoxide (DMSO) as an internal standard. The amount of SiVi groups indicates the number of moles of vinyl groups directly bonded to silicon atoms in the molecule, and was measured using a Bruker Nuclear Magnetic Resonance (NMR) measurement device. 1 The values ​​were quantified by H-NMR measurement using DMSO as an internal standard.

[0101] <Component (A-1)> (a1-1) : The siloxane unit is ViMe2SiO 1 / 2 Units: 10 mol%, Me3SiO 1 / 2 The unit is 40 mol%, SiO 4 / 2 A branched organopolysiloxane which is solid at 25°C, is expressed in units of 50 mol%, has a SiVi group amount of 0.08 mol / 100 g, has a weight average molecular weight of 5,600 as measured by GPC, and contains 0.1 mass% of low-molecular-weight siloxane compounds having a degree of polymerization of 10 or less. (a1-2) : The siloxane unit is ViMe2SiO 1 / 2 Units: 10 mol%, Me3SiO 1 / 2 Units: 35 mol%, MeSiO 3 / 2 The unit is 25 mol%, SiO 4 / 2 A branched organopolysiloxane which is liquid at 25°C, is expressed in units of 30 mol%, has a SiVi group amount of 0.09 mol / 100 g, has a weight average molecular weight of 4,900 as measured by GPC, and contains 0.1 mass% of low-molecular-weight siloxane compounds having a degree of polymerization of 10 or less.

[0102] <Component (A-2)> (a2-1) :The following formula (ViMe2SiO 1 / 2 )2(Ph2SiO 2 / 2 )20 (MeSiO 2 / 2 ) 350 A linear organopolysiloxane having a SiVi group content of 0.006 mol / 100 g, which is liquid at 25°C, contains 0.1 mass% low-molecular-weight siloxane compounds with a degree of polymerization of 10 or less, and has a viscosity of 5,100 mPa s at 25°C. (a2-2) :The following formula (ViMe2SiO 1 / 2 )2(Me2SiO 2 / 2 ) 388 A linear organopolysiloxane having a SiVi group content of 0.006 mol / 100 g, which is liquid at 25°C, contains 0.1 mass % low-molecular-weight siloxane compounds with a degree of polymerization of 10 or less, and has a viscosity at 25°C of 5,000 mPa s.

[0103] <(B) component> (b-1) :The following formula (Me3SiO 1 / 2 )2(HMeSiO 2 / 2 ) 72 (MeSiO 2 / 2 ) 24 This organohydrogenpolysiloxane has a hydrosilyl group content of 1.14 mol / 100 g, is liquid at 25°C, contains 0.1 mass% low-molecular-weight siloxane compounds with a degree of polymerization of 10 or less, and has a viscosity of 163 mPa s at 25°C. (b-2) :The following formula (Me3SiO 1 / 2 )2(HMeSiO 2 / 2 ) 86 (MeSiO 2 / 2 ) 10 The organohydrogenpolysiloxane has a hydrosilyl group content of 1.40 mol / 100 g, is liquid at 25°C, contains 0.1 mass% low-molecular-weight siloxane compounds with a degree of polymerization of 10 or less, and has a viscosity of 165 mPa s at 25°C.

[0104] <(C) component> (c-1) : A 1,3-divinyltetramethyldisiloxane solution of a 1,3-divinyltetramethyldisiloxane complex of platinum(0) having a platinum content of 2 mass% and a SiVi group amount of 1.05 mol / 100 g.

[0105] <(D) component> (d-1) : Spherical aluminum oxide particles having a Mohs hardness of 9, an average particle size (D50) of 5.7 μm, and an alpha conversion rate of 95% (manufactured by Admatechs Co., Ltd.). (d-2) : Spherical aluminum oxide particles having a Mohs hardness of 9, an average particle size (D50) of 0.2 μm, and an alpha conversion rate of 85.0% (manufactured by Admatechs Co., Ltd.: AC-2055) (d-3) : Spherical aluminum oxide particles (for comparison) having a Mohs hardness of 9, an average particle size (D50) of 23.8 μm, and a gelatinization rate of 10% (manufactured by Denka Co., Ltd.: DAW-20). (d-4) : Spherical silicon carbide particles having a Mohs hardness of 10 and an average particle size (D50) of 5.2 μm (SSC-A05, manufactured by Shinano Electric Smelting Co., Ltd.). (d-5) : Spherical aluminum particles having a Mohs hardness of 3 and an average particle size (D50) of 20.8 μm (manufactured by Toyo Aluminum Co., Ltd.). (d-6) : Spherical aluminum particles having a Mohs hardness of 3 and an average particle size (D50) of 44.7 μm (manufactured by Toyo Aluminum Co., Ltd.). (d-7) : Spherical aluminum particles (for comparison) having a Mohs hardness of 3 and an average particle size (D50) of 6.0 μm (manufactured by Toyo Aluminum Co., Ltd.: TFH-A05P). (d-8) : Spherical silver particles with a Mohs hardness of 3 and an average particle size (D50) of 19.0 μm (manufactured by Ames Advanced Materials Co., Ltd.: 27019-NM1). (d-9) : Spherical silver particles with a Mohs hardness of 3 and an average particle size (D50) of 5.5 μm. (For comparison) (Sylvest AgF-5S, manufactured by Tokuriki Honten Co., Ltd.)

[0106] <(E) component> (e-1) : The siloxane unit is Ep'SiO 3 / 2 Units: 29 mol%, Me2SiO 2 / 2 The unit is 64 mol%, ViMeSiO 2 / 2 A branched organopolysiloxane having 6 mol% OMe units and 1 mol% OMe units, a weight average molecular weight of 2,400, an SiVi group amount of 0.05 mol / 100 g, an epoxy equivalent of 330 g / eq, which is liquid at 25°C, has 0.3 mass% low molecular weight siloxane compounds with a degree of polymerization of 10 or less, and a viscosity at 25°C of 350 mPa s. (e-2) : The siloxane unit is MeSiO 3 / 2 25 mol% of the unit Ep'MeSiO 2 / 2 Units: 22 mol%, Me2SiO 2 / 2 The unit is 47 mol%, ViMeSiO 2 / 2 A branched organopolysiloxane having 5 mol % OMe units and 1 mol % OMe units, a weight average molecular weight of 4,500, an SiVi group amount of 0.05 mol / 100 g, an epoxy equivalent of 435 g / eq, which is liquid at 25°C, has 0.1 mass % low molecular weight siloxane compounds with a degree of polymerization of 10 or less, and a viscosity at 25°C of 355 mPa s.

[0107] <Cure inhibitor> (g-1) : Ethynylcyclohexanol

[0108] [Examples 1 to 12, Comparative Examples 1 to 7] The addition-curable silicone resin compositions of Examples 1 to 12 and Comparative Examples 1 to 7 were prepared according to the compounding ratios (values ​​are parts by mass) shown in Tables 1 and 2, and the compositions were evaluated for hardness, tensile strength, elongation at break, storage modulus at -40°C of the cured products, adhesion, thermal conductivity, adhesive strength, content of low-molecular-weight siloxane compounds with a degree of polymerization of 10 or less, and storage stability using the test methods shown below. The results of each measurement are shown in Tables 1 and 2.

[0109] (a) Hardness The addition-curable silicone resin composition was heated at 100° C. for 1 hour using a hot air circulation dryer to produce a silicone cured product. The silicone cured product was measured using a Type A durometer in accordance with JIS K 6253-3:2012.

[0110] (b) Tensile strength, elongation at break The addition-curable silicone resin composition was heated in a hot air circulating dryer at 100°C for 1 hour to produce a silicone cured product. The tensile strength and elongation at break of the silicone cured product were measured in accordance with JIS K 6251:2017.

[0111] (c) Storage modulus of cured material at -40°C The addition-curable silicone resin composition was heated in a hot air circulating dryer at 100°C for 1 hour to produce a 2 mm thick sheet-shaped silicone cured product. The storage modulus of the silicone cured product at -40°C was measured using a dynamic viscoelasticity measuring device (DMA) "Q800" manufactured by TA Instruments Japan, Inc.

[0112] (d) Adhesiveness / adhesive strength A given amount of addition-curable silicone resin composition was applied onto a glass epoxy substrate, FR-4, and a Si chip measuring 3.0 mm x 3.0 mm was die-bonded, followed by heat curing at 100°C for 1 hour using a hot air circulation dryer. After heating, the removed package was cooled to 25°C, and the adhesive strength between the chip and substrate was measured for each cured resin product using a bond tester (Nordson Advanced Technology Corp.: Dage4000) for 50 tests, and the average adhesive strength was calculated.

[0113] (e) Thermal conductivity The addition-curable silicone resin composition was heated at 100° C. for 1 hour using a hot air circulation dryer to produce sheet-shaped silicone cured products with thicknesses of 0.5 mm, 1 mm, and 2 mm.

[0114] The cured material of each thickness was cut into 10 mm squares, and the thermal resistance value for each thickness was obtained using a resin material thermal resistance measuring device (manufactured by Hitachi Technology and Services), which uses the steady-state measurement principle (load: 100 kPa). After plotting the three measurement results, an approximation curve was drawn using linear approximation, and the thermal conductivity of each cured resin was calculated from the slope of the linear approximation curve and the size of the cured material.

[0115] (f) Content of low molecular weight siloxane compounds with a degree of polymerization of 10 or less The content of low molecular weight siloxane compounds having a degree of polymerization of 10 or less in the addition-curable silicone resin composition was measured using the same method as described above.

[0116] (g) Storage stability The addition-curable silicone resin compositions were stored in a -20°C freezer for one month, and then thawed to room temperature and the surface condition was observed. Those in which no separation of the resin and filler was observed were marked with "◯", and those in which separation was observed were marked with "X".

[0117] (f) Damage to silicon chips The addition-curable silicone resin composition was sandwiched between two 10 mm square silicon wafers, and the silicon wafers were manually shaken up and down a total of 100 times at about one second per shake. The silicon wafers were then washed with toluene, and the surfaces were observed under an optical microscope. If there were no scratches on the surface, it was marked as "O", and if there were scratches, it was marked as "X".

[0118] [Table 1]

[0119] [Table 2]

[0120] The results of the above evaluation tests demonstrated that the addition-curable silicone resin compositions of the present invention (Examples 1 to 12) had excellent resin strength, excellent adhesive strength, and achieved both thermal conductivity and low elasticity.

[0121] On the other hand, in Comparative Example 1, only the aluminum oxide particles (D-1) (d-1 and d-2) were used as the component (D), so the storage modulus was high and the chip damage resistance was rated "x".

[0122] In Comparative Example 2, only the aluminum particles (D-2) (d-6 and d-7) were used as the component (D), and as a result, the resin strength and adhesiveness of the obtained cured product were low.

[0123] In Comparative Example 3, the component (D) was a combination of components (d-1, d-2, and d-5) corresponding to the components (D-1) and (D-2). However, the content of aluminum particles (d-5) having a large particle size was high, and the resin strength of the obtained cured product was low. Furthermore, separation of the components during storage was confirmed.

[0124] In Comparative Example 4, components (d-1, d-2, and d-5) corresponding to components (D-1) and (D-2) were combined as component (D), but the content ratio of aluminum oxide particles (d-1) having a small particle size was high, and the storage modulus of the obtained cured product at -40°C was high.

[0125] In addition, in Comparative Example 5, only silver particles (d-8 and d-9) corresponding to component (D-2) were used as component (D), so the resin strength of the obtained cured product was low and separation of the components was confirmed during storage.

[0126] Furthermore, in Comparative Example 6, component (D) was not blended, and the thermal conductivity was very low.

[0127] In Comparative Example 7, the component (A-1) was not blended, and the adhesiveness of the cured resin was poor.

[0128] In this way, it has been confirmed that the addition-curable silicone resin composition of the present invention has excellent resin strength, excellent adhesive strength, and is capable of achieving both thermal conductivity and low elasticity, and is therefore extremely useful as a die attach material for semiconductor device.

[0129] The present invention is not limited to the above-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention.

Claims

1. An addition-curable silicone resin composition comprising the following components (A) to (D), wherein a cured product of the composition has a thermal conductivity of 1.0 W / m K or more and a storage modulus at -40°C of 250 MPa or less: (A) An alkenyl group-containing organopolysiloxane comprising the following components (A-1) and (A-2): (A-1) The following formula (1) (R １ １ R ２ ２ SiO １／２ ) ａ (R ２ ３ SiO １／２ ) ｂ (R ２ ２ SiO ２／２ ) ｃ (R ２ SiO ３／２ ) ｄ (SiO ４／２ ) ｅ (1) (In the formula, R １ is an alkenyl group having 2 to 8 carbon atoms, R ２ are independently an alkyl group having 1 to 12 carbon atoms, 0.01<a<0.15, 0.3<b<0.6, 0≦c, 0≦d, and 0.25<e<0.67, and are numbers which satisfy a+b+c+d+e=1. and a branched organopolysiloxane having two or more alkenyl groups having 2 to 8 carbon atoms in one molecule. (A-2) The following formula (2) (R １ R ２ ２ SiO １／２ ) ２ (R ２ ２ SiO ２／２ ) ｘ (R ３ ２ SiO ２／２ ) ｙ (2) (In the formula, R １ and R ２ are the same as above, and R ３ are independently an aryl group having 6 to 12 carbon atoms, and x and y are numbers such that x>0, y≧0, 0.85≦(x / (x+y)), and 50≦x+y≦5,000. A linear organopolysiloxane represented by the formula: (B) The following formula (3): (R ２ ３ Yes １／２ ) ２ (HR) ２ Yes ２／２ ) ｊ (R ２ ２ Yes ２／２ ) ｋ (3) (In the formula, R ２ are the same as above, and j and k are positive numbers satisfying 0.60≦(j / (j+k))≦0.95, and 30≦j+k≦120, in which the content of hydrosilyl group-containing organosilicon compounds having 1 to 10 silicon atoms is 5 mass% or less; (C) an addition cure catalyst, and (D) A thermally conductive filler consisting of the following components (D-1) and (D-2): (D-1) A thermally conductive filler having a Mohs hardness of 5 or more and an average particle size (D50) of 0.1 to 10 μm; (D-2) A thermally conductive filler having a Mohs hardness of less than 5 and an average particle size (D50) of 10 to 50 μm. (wherein, (D-1):(D-2)=20:80 to 80:20 (mass ratio)).

2. 2. The addition-curable silicone resin composition according to claim 1, wherein the content of component (D) is 65 to 90 mass % of the total composition.

3. 2. The addition-curable silicone resin composition according to claim 1, wherein the component (D-1) is spherical aluminum oxide particles.

4. 2. The addition-curable silicone resin composition according to claim 1, wherein the component (D-2) is spherical aluminum particles.

5. Furthermore, as the adhesive assistant (E), a compound represented by the following formula (4) (MeSi) ３／２ ) ｐ１ (EpSiO) ３／２ ) ｐ２ (Ep. Me. Si.) ２／２ ) ｑ１ (Me) ２ SiO ２／２ ) ｑ２ (Violet) ２／２ ) ｑ３ (OR) ５ ) ｒ (4) (In the formula, Me is a methyl group, Ep is a monovalent organic group having an epoxy group, Vi is a vinyl group, and R ５ is an alkyl group having 1 to 12 carbon atoms, 0≦p1<0.35, 0≦p2<0.35, 0≦q1<0.35, 0.4≦q2<0.7, 0<q3<0.1, 0≦r<0.05, and 0.15≦(p2+q1) / (p1+p2+q1+q2+q3+r)≦0.35, provided that p1+p2+q1+q2+q3+r=1.

2. The addition-curable silicone resin composition according to claim 1, which contains a branched organopolysiloxane having a weight average molecular weight of 1,500 to 8,000 and an epoxy equivalent of 250 to 500 g / eq.

6. The addition curable silicone resin composition as a whole contains a low molecular weight siloxane compound having a degree of polymerization of 10 or less.

2. The addition-curable silicone resin composition according to claim 1, wherein the amount of the copolymer is 1% by weight or less.

7. A die attach material for semiconductor device, comprising the addition-curable silicone resin composition according to any one of claims 1 to 6.

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