Adhesive paste, method of using adhesive paste, and method of manufacturing semiconductor device

Abstract

To provide an adhesive paste and the like which can reduce or prevent thermal degradation of an optical component, a sensor chips or the like due to heat generated by a semiconductor element or a semiconductor device comprising the semiconductor element and also reduce or prevent peeling of the semiconductor element in a wire bonding process.SOLUTION: There are provided an adhesive paste or the like which contain a curable organopolysiloxane compound (A) and a thermally conductive filler (T), wherein the thermal conductivity of a cured product obtained by heat-curing the adhesive paste at 120°C for 4 hours is 0.5 W / (m K) or more and the adhesive strength at 100°C between a cured product obtained by heat-curing the adhesive paste at 170°C for 2 hours and a silver-plated copper plate is 5 N / mm sq, or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an adhesive paste in which the cured product obtained by heat curing has high thermal conductivity and the cured product obtained by heating at high temperatures has excellent adhesiveness; a method for using this adhesive paste as an adhesive for semiconductor element fixing material; and a method for manufacturing a semiconductor device in which this adhesive paste is used as an adhesive for semiconductor element fixing material. [Background technology]

[0002] Conventionally, adhesive pastes have been improved in various ways depending on the application, and have been widely used in industry as raw materials for optical components and molded bodies, adhesives, coating agents, and the like. The adhesive paste has also been attracting attention as a paste for semiconductor element fixing materials, such as an adhesive for semiconductor element fixing materials.

[0003] Semiconductor elements include optical semiconductor elements such as light-emitting elements such as lasers and light-emitting diodes (LEDs) and light-receiving elements such as solar cells, transistors, sensors such as temperature sensors and pressure sensors, and integrated circuits.

[0004] In recent years, semiconductor elements have been dramatically improved in brightness and power output, and as a result, the amount of heat generated by semiconductor elements has tended to increase further.

[0005] However, with the recent trend toward higher brightness and higher output of semiconductor elements, the cured adhesive paste used to fix the elements is exposed to higher energy light or higher temperatures generated by the semiconductor elements for a long period of time, which can cause problems such as a decrease in adhesive strength or deterioration leading to peeling, or a deterioration in the performance of the semiconductor elements. Therefore, it is an important issue to improve the thermal conductivity of the cured adhesive paste, to efficiently dissipate the heat generated by the semiconductor element, and to maintain or improve the performance of the semiconductor element at a high level.

[0006] On the other hand, a method for manufacturing a semiconductor device including a semiconductor element is known that includes, for example, a step of fixing the semiconductor element to an adherend such as a lead frame with an adhesive sheet, a step of curing the adhesive sheet, and a wire bonding step.

[0007] However, with the recent trend toward miniaturization of semiconductor elements, the ultrasonic waves generated by the wire bonding device have made it easier for small semiconductor elements to vibrate, and tension is generated in the bonded wire, which has led to the problem of peeling of the semiconductor elements during the wire bonding process. Therefore, there is a demand for an adhesive paste with excellent adhesive properties that can prevent peeling of semiconductor elements, so as to accommodate various wire bonding conditions such as the type of semiconductor element and the curing temperature of the adhesive paste.

[0008] In relation to the present invention, for example, Patent Document 1 describes a curable composition that produces a cured product with excellent adhesiveness. However, the curable composition described in Patent Document 1 does not focus on the thermal conductivity of the cured product obtained by heat-curing the curable composition, and does not describe any evaluation results regarding thermal degradation of semiconductor elements. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] International Publication No. 2020 / 067451 Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in view of the above circumstances, and aims to provide an adhesive paste that can reduce or prevent thermal degradation of optical components, sensor chips, etc. that accompanies heat generation in semiconductor elements and semiconductor devices that include such semiconductor elements, and that can reduce or prevent peeling of semiconductor elements in wire bonding processes; a method for using this adhesive paste as an adhesive for semiconductor element fixing materials; and a method for manufacturing a semiconductor device that uses this adhesive paste as an adhesive for semiconductor element fixing materials. In the present invention, "high temperature" refers to "150°C to 190°C." Moreover, "excellent adhesiveness" means "high adhesive strength." [Means for solving the problem]

[0011] The present inventors have conducted extensive research to solve the above problems. (i) A cured product with high thermal conductivity obtained by heat-curing an adhesive paste containing a curable organopolysiloxane compound can reduce or prevent thermal degradation of optical components, sensor chips, etc., which is caused by heat generation from semiconductor elements or semiconductor devices including such semiconductor elements; and (ii) It was discovered that a cured product having a specific adhesive strength obtained by heating an adhesive paste containing a curable organopolysiloxane compound at a high temperature can reduce or prevent peeling of semiconductor elements during the wire bonding process, leading to the completion of the present invention.

[0012] Thus, according to the present invention, the following [1] to [3] 〔10〕 adhesive paste, 〔11〕 How to use the adhesive paste, and 〔12〕 A method for manufacturing a semiconductor device using the adhesive paste is provided.

[0013] [1] An adhesive paste containing a curable organopolysiloxane compound (A) and a thermally conductive filler (T), the thermal conductivity of the cured product obtained by heating and curing the adhesive paste at 120°C for 4 hours is 0.5 W / (m K) or more; The adhesive paste has an adhesive strength of 5 N / mm□ or more between the cured product obtained by heating and curing the adhesive paste at 170°C for 2 hours and a silver-plated copper plate at 100°C. [2] The adhesive paste according to [1], wherein the curable organopolysiloxane compound (A) is a polysilsesquioxane compound. [3] The adhesive paste according to [1] or [2], wherein the thermally conductive filler (T) is an inorganic filler having a thermal conductivity of 5 W / (m·K) or more. [4] The adhesive paste according to any one of [1] to [3], wherein the thermally conductive filler (T) is at least one selected from the group consisting of titanium oxide, alumina, and aluminum nitride.

[0014] [5] The adhesive paste according to any one of [1] to [3], wherein the thermally conductive filler (T) is titanium oxide. [6] The adhesive paste according to any one of [1] to [5], wherein the volume filling rate of the thermally conductive filler (T) in the solid content of the adhesive paste is 10 vol % or more and less than 60 vol %. [7] The adhesive paste according to any one of [1] to [6], which contains 1.5 parts by mass or more and less than 20 parts by mass of the silane coupling agent (B) per 100 parts by mass of the solid content of the adhesive paste. [8] Substantially no precious metal catalyst, [1] to 〔7〕 10. The adhesive paste according to claim 1, wherein

[0015] [9] The adhesive paste according to any one of [1] to (8), having a solid content concentration of 90% by mass or more and 99% by mass or less.

[10] An adhesive for semiconductor element fixing material, [1] to 〔9〕 10. The adhesive paste according to claim 1, wherein

[11] [1] ~ 〔9〕 10. A method of using the adhesive paste according to any one of the preceding items as an adhesive for a semiconductor element fixing material.

[12] [1] ~ 〔9〕 1. A method for manufacturing a semiconductor device using the adhesive paste according to any one of the above items as an adhesive for a semiconductor element fixing material, the method comprising the following steps (BI) and (BII): Step (BI): A step of applying the adhesive paste to the adhesive surface of one or both of the semiconductor element and the supporting substrate, and pressing them together. Step (BII): A step of heating and hardening the adhesive paste of the pressure-bonded product obtained in Step (BI) to fix the semiconductor element to the support substrate. [Effects of the Invention]

[0016] According to the present invention, an adhesive paste is provided that can reduce or prevent thermal degradation of optical components, sensor chips, etc. that occurs due to heat generation from semiconductor elements or semiconductor devices that include such semiconductor elements, and can also reduce or prevent peeling of semiconductor elements during wire bonding processes. The present invention also provides a method for using this adhesive paste as an adhesive for a semiconductor element fixing material, and a method for manufacturing a semiconductor device using this adhesive paste as an adhesive for a semiconductor element fixing material. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described in detail below, divided into the following sections: 1) adhesive paste, 2) method of using the adhesive paste, and method of manufacturing a semiconductor device using the adhesive paste.

[0018] 1) Adhesive paste The adhesive paste of the present invention is an adhesive paste containing a curable organopolysiloxane compound (A) and a thermally conductive filler (T), wherein the cured product obtained by heat-curing the adhesive paste at 120°C for 4 hours has a thermal conductivity of 0.5 W / (m·K) or more, and the cured product obtained by heat-curing the adhesive paste at 170°C for 2 hours has an adhesive strength of 5 N / mm□ or more at 100°C between the cured product and a silver-plated copper plate.

[0019] In the present invention, the term "adhesive paste" refers to a "viscous liquid that is in a fluid state at room temperature (23°C)." The adhesive paste of the present invention has the properties in the above-described state, and therefore has excellent workability in the application step. Here, "excellent workability in the application process" means "in the application process, when the adhesive paste is discharged from the discharge pipe and then the discharge pipe is pulled up, the amount of stringiness is small or the pipe breaks immediately, so that the resin does not fly, and the surrounding area is not contaminated by droplets spreading after application."

[0020] The adhesive paste of the present invention is one that has a thermal conductivity of 0.5 W / (m·K) or more, preferably 0.7 W / (m·K) or more, more preferably 1.0 W / (m·K) or more, even more preferably 1.5 W / (m·K) or more, and particularly preferably 2.0 W / (m·K) or more, of the cured product obtained by heating and curing the adhesive paste at 120°C for 4 hours. A cured product obtained by heat curing and having a thermal conductivity equal to or greater than the above lower limit can reduce or prevent thermal degradation of optical components, sensor chips, etc., associated with heat generation from semiconductor elements or semiconductor devices incorporating such semiconductor elements. The thermal conductivity of the cured product obtained by heat-curing the adhesive paste of the present invention can be measured and calculated, for example, as follows. That is, the adhesive paste of the present invention is poured into a Teflon (registered trademark) frame and cured by heat treatment at 120°C for 4 hours to prepare a test piece. Then, using a thermal diffusivity measuring device, the thermal diffusivity of this test piece is measured by the temperature wave method. In addition, the specific heat of the components constituting the cured product obtained by heat-curing the adhesive paste, excluding the thermally conductive filler (T), is measured to be 1 J / (g·K) and the density is measured to be 1.2 g / cm. 3 Assuming this, calculate the thermal conductivity using the following formula. Thermal conductivity (W / (m·K)) = Thermal diffusivity (m 2 / s) × specific heat (J / (g K)) × density (g / cm 3 ) x 10 6 More specifically, it can be measured by the method described in the Examples.

[0021] The adhesive paste of the present invention has an adhesive strength at 100°C between the cured product obtained by heating and curing the adhesive paste at 170°C for 2 hours and a silver-plated copper plate of 5 N / mm□ or more, preferably 10 N / mm□ or more, and more preferably 13 N / mm□ or more. When the adhesive strength is equal to or greater than the above lower limit, the cured product obtained by heat curing at high temperature can reduce or prevent peeling of the semiconductor element during the wire bonding step. The adhesive strength of the cured product obtained by heat-curing the adhesive paste of the present invention can be measured, for example, as follows. 2 The adhesive paste of the present invention is applied to the mirror surface of a silicon chip (100 mm square), and the applied surface is placed on a silver-plated copper plate and pressed (thickness of adhesive paste after pressing: approximately 3 μm), and then cured by heat treatment at 170°C for 2 hours. This is left on the measurement stage of a bond tester at 100°C for 60 seconds, and stress is applied to the adhesive surface in the horizontal direction (shear direction) at a speed of 200 μm / s from a position 100 μm above the adherend, and the adhesive strength (N / mm□) between the test piece and the adherend is measured. In this specification, "1 mm square" means "1 mm square," that is, "1 mm x 1 mm (a square with one side length of 1 mm)." More specifically, it can be measured by the method described in the Examples.

[0022] [Curable organopolysiloxane compound (A)] The adhesive paste of the present invention contains a curable organopolysiloxane compound (A) (hereinafter sometimes referred to as "component (A)"). The adhesive paste of the present invention, containing component (A), can easily give a cured product with excellent adhesiveness when heated at a high temperature.

[0023] The curable organopolysiloxane compound (A) of the present invention is a compound having a carbon-silicon bond and a siloxane bond (—Si—O—Si—) in the molecule. Furthermore, since component (A) is a thermosetting compound, it preferably has at least one functional group selected from the group consisting of functional groups capable of undergoing a condensation reaction upon heating and functional groups capable of undergoing a condensation reaction via hydrolysis. Such a functional group is preferably at least one selected from the group consisting of a hydroxyl group and an alkoxy group, and more preferably a hydroxyl group or an alkoxy group having 1 to 10 carbon atoms. There are no limitations on the main chain structure of the curable organopolysiloxane compound (A), and it may be linear, ladder-like, or cage-like. For example, an example of a linear main chain structure is a structure represented by the following formula (a-1), an example of a ladder-like main chain structure is a structure represented by the following formula (a-2), and an example of a cage-like main chain structure is a structure represented by the following formula (a-3).

[0024] [ka]

[0025] [ka]

[0026] [ka]

[0027] In formulas (a-1) to (a-3), Rx, Ry, and Rz each independently represent a hydrogen atom or an organic group, and the organic group is preferably an unsubstituted or substituted alkyl group, an unsubstituted or substituted cycloalkyl group, an unsubstituted or substituted alkenyl group, an unsubstituted or substituted aryl group, or an alkylsilyl group. The multiple Rx in formula (a-1), the multiple Ry in formula (a-2), and the multiple Rz in formula (a-3) may be the same or different. However, two Rx in formula (a-1) cannot both be hydrogen atoms.

[0028] Examples of the alkyl group of the unsubstituted or substituted alkyl group include alkyl groups having 1 to 10 carbon atoms, such as a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, n-heptyl group, and n-octyl group.

[0029] Examples of the cycloalkyl group of the unsubstituted or substituted cycloalkyl group include cycloalkyl groups having 3 to 10 carbon atoms, such as a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.

[0030] Examples of the alkenyl group of the unsubstituted or substituted alkenyl group include alkenyl groups having 2 to 10 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, and 3-butenyl.

[0031] Examples of the substituent on the alkyl group, cycloalkyl group, and alkenyl group include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; a hydroxyl group; a thiol group; an epoxy group; a glycidoxy group; a (meth)acryloyloxy group; and unsubstituted or substituted aryl groups such as a phenyl group, a 4-methylphenyl group, and a 4-chlorophenyl group.

[0032] Examples of the aryl group of the unsubstituted or substituted aryl group include aryl groups having 6 to 10 carbon atoms, such as a phenyl group, a 1-naphthyl group, and a 2-naphthyl group.

[0033] Examples of the substituent on the aryl group include halogen atoms such as fluorine atom, chlorine atom, bromine atom, and iodine atom; alkyl groups having 1 to 6 carbon atoms such as methyl group and ethyl group; alkoxy groups having 1 to 6 carbon atoms such as methoxy group and ethoxy group; nitro group; cyano group; hydroxyl group; thiol group; epoxy group; glycidoxy group; (meth)acryloyloxy group; and unsubstituted or substituted aryl groups such as phenyl group, 4-methylphenyl group, and 4-chlorophenyl group.

[0034] Examples of the alkylsilyl group include a trimethylsilyl group, a triethylsilyl group, a triisopropylsilyl group, a tri-t-butylsilyl group, a methyldiethylsilyl group, a dimethylsilyl group, a diethylsilyl group, a methylsilyl group, and an ethylsilyl group.

[0035] Among these, Rx, Ry, and Rz are preferably a hydrogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, or a phenyl group, and particularly preferably an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms.

[0036] The curable organopolysiloxane compound (A) can be obtained by a known production method, for example, by polycondensing a silane compound having a hydrolyzable functional group (alkoxy group, halogen atom, etc.).

[0037] The silane compound to be used may be appropriately selected depending on the structure of the desired thermosetting organopolysiloxane compound (A). Preferred specific examples include bifunctional silane compounds such as dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, and diethyldiethoxysilane; trifunctional silane compounds such as methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-butyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and phenyldiethoxymethoxysilane; Examples thereof include tetrafunctional silane compounds such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetra-t-butoxysilane, tetra-s-butoxysilane, methoxytriethoxysilane, dimethoxydiethoxysilane, and trimethoxyethoxysilane.

[0038] The mass average molecular weight (Mw) of the curable organopolysiloxane compound (A) is usually from 800 to 30,000, preferably from 1,000 to 20,000, more preferably from 1,200 to 15,000, and particularly preferably from 3,000 to 10,000. By using a curable organopolysiloxane compound (A) having a mass average molecular weight (Mw) within the above range, it becomes easier to obtain an adhesive paste that gives a cured product with excellent heat resistance and adhesiveness.

[0039] The molecular weight distribution (Mw / Mn) of the curable organopolysiloxane compound (A) is not particularly limited, but is usually from 1.0 to 10.0, preferably from 1.1 to 6.0. By using a curable organopolysiloxane compound (A) having a molecular weight distribution (Mw / Mn) within the above range, it becomes easier to obtain an adhesive paste that gives a cured product with excellent heat resistance and adhesiveness. The mass average molecular weight (Mw) and number average molecular weight (Mn) can be determined, for example, as a standard polystyrene equivalent value by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0040] The curable organopolysiloxane compound (A) of the present invention is preferably a polysilsesquioxane compound obtained by polycondensation of a trifunctional organosilane compound. The adhesive paste of the present invention contains a polysilsesquioxane compound as component (A), which makes it easier to obtain a cured product with excellent adhesiveness when heated at high temperatures, thereby enabling more efficient chip retention in the wire bonding process.

[0041] The polysilsesquioxane compound of the present invention is a compound having a repeating unit represented by the following formula (a-4). The adhesive paste of the present invention contains, as component (A), a polysilsesquioxane compound having a repeating unit represented by the following formula (a-4), which makes it easier to obtain a cured product with excellent adhesiveness when heated at a high temperature.

[0042] [ka]

[0043] In formula (a-4), (R 1 -D) represents an organic group. 1 -D) among R 1is preferably an unsubstituted alkyl group or an alkyl group having a substituent, and more preferably an unsubstituted alkyl group having 1 to 10 carbon atoms or an alkyl group having 1 to 10 carbon atoms and having a substituent. 1 and Si, or a single bond (excluding alkylene groups).

[0044] Examples of the "unsubstituted alkyl group having 1 to 10 carbon atoms" include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an n-nonyl group, and an n-decyl group. R 1 The "unsubstituted alkyl group having 1 to 10 carbon atoms" represented by the following formula (I) preferably has 1 to 6 carbon atoms, and more preferably has 1 to 3 carbon atoms.

[0045] R 1 The number of carbon atoms in the "substituted alkyl group having 1 to 10 carbon atoms" represented by the formula (I) is preferably 1 to 6, and more preferably 1 to 3. Note that this number of carbon atoms refers to the number of carbon atoms in the portion excluding the substituent (the alkyl group portion). Therefore, R 1 is a "substituted alkyl group having 1 to 10 carbon atoms", R 1 The number of carbon atoms may exceed 10. Examples of the alkyl group in the "substituted alkyl group having 1 to 10 carbon atoms" include the same groups as those given as the "unsubstituted alkyl group having 1 to 10 carbon atoms".

[0046] Examples of the substituent in the "substituted alkyl group having 1 to 10 carbon atoms" include a halogen atom such as a fluorine atom, a chlorine atom, or a bromine atom; a cyano group; a group represented by the formula: OJ; and the like. The number of atoms of the substituent in the "substituted alkyl group having 1 to 10 carbon atoms" (excluding the number of hydrogen atoms) is usually 1 to 30, and preferably 1 to 20. Here, J represents a protecting group for a hydroxyl group. The protecting group for a hydroxyl group is not particularly limited, and examples thereof include known protecting groups known as protecting groups for a hydroxyl group. Examples thereof include acyl-based protecting groups; silyl-based protecting groups such as trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, and t-butyldiphenylsilyl; acetal-based protecting groups such as methoxymethyl, methoxyethoxymethyl, 1-ethoxyethyl, tetrahydropyran-2-yl, and tetrahydrofuran-2-yl; alkoxycarbonyl-based protecting groups such as t-butoxycarbonyl; and ether-based protecting groups such as methyl, ethyl, t-butyl, octyl, allyl, triphenylmethyl, benzyl, p-methoxybenzyl, fluorenyl, trityl, and benzhydryl.

[0047] Among these, R 1 As the alkyl group, from the viewpoint of easily obtaining a polysilsesquioxane compound with a stable structure and more stable performance as an adhesive paste, an unsubstituted alkyl group having 1 to 10 carbon atoms or an alkyl group having 1 to 10 carbon atoms and a fluorine atom is preferred, and an alkyl group having 1 to 10 carbon atoms and a fluorine atom is more preferred. R 1 However, by using a polysilsesquioxane compound that is an unsubstituted alkyl group having 1 to 10 carbon atoms, it becomes easier to obtain an adhesive paste that gives a cured product that is more excellent in heat resistance and adhesiveness. R 1 However, by using a polysilsesquioxane compound having a fluorine atom and an alkyl group having 1 to 10 carbon atoms, adhesive pastes and cured products with low refractive indexes can be easily obtained, making them suitable for use in optical semiconductor elements that require a low refractive index. Furthermore, when the semiconductor element is an optical semiconductor element, the light extraction efficiency of the optical semiconductor element can be improved, and a decrease in light emission efficiency can be suppressed.

[0048] The alkyl group having 1 to 10 carbon atoms and a fluorine atom includes the alkyl group having the composition formula: C m H (2m-n+1) F n(wherein m is an integer of 1 to 10, and n is an integer of 2 or more and (2m+1) or less). Here, m is preferably an integer of 1 to 5, and more preferably an integer of 1 to 3.

[0049] Composition formula: C m H (2m-n+1) F n Examples of the fluoroalkyl group represented by the formula (I) include perfluoroalkyl groups such as CF3, CF3CF2, CF3(CF2)2, CF3(CF2)3, CF3(CF2)4, CF3(CF2)5, CF3(CF2)6, CF3(CF2)7, CF3(CF2)8, and CF3(CF2)9; and hydrofluoroalkyl groups such as CF3CH2CH2, CF3(CF2)3CH2CH2, CF3(CF2)5CH2CH2, and CF3(CF2)7CH2CH2. Among these, the CF3CH2CH2 group is preferred.

[0050] In formula (a-4), D is R 1 and Si, or a single bond (excluding an alkylene group), and a single bond is preferred. Examples of the linking group for D include arylene groups having 6 to 20 carbon atoms, such as a 1,4-phenylene group, a 1,3-phenylene group, a 1,2-phenylene group, and a 1,5-naphthylene group.

[0051] Polysilsesquioxane compounds are a type of (R 1 -D), and may be a polymer having two or more (R 1 -D) (copolymer).

[0052] When the polysilsesquioxane compound is a copolymer, the polysilsesquioxane compound may be any of a random copolymer, a block copolymer, a graft copolymer, an alternating copolymer, etc., but from the viewpoint of ease of production, etc., a random copolymer is preferred. The structure of the polysilsesquioxane compound may be any of a ladder structure, a double-decker structure, a cage structure, a partially cleaved cage structure, a cyclic structure, and a random structure.

[0053] The content of the repeating unit represented by the formula (a-4) (i.e., the T site described below) in the polysilsesquioxane compound is typically 50 to 100 mol %, more preferably 70 to 100 mol %, even more preferably 90 to 100 mol %, and particularly preferably 100 mol %, based on all repeating units. By using a polysilsesquioxane compound in which the content ratio of the repeating unit (T site) represented by the formula (a-4) is in the above-mentioned ratio, an adhesive paste that is likely to exhibit heat resistance, adhesiveness, and refractive index performance can be obtained.

[0054] The repeating unit represented by the formula (a-4) in the polysilsesquioxane compound may be a repeating unit represented by the following formula (a-5): 1 -D) is R in the following formula (a-5): 2 may be.

[0055] [ka]

[0056] In formula (a-5), R 2 represents a group selected from the group consisting of an unsubstituted cycloalkyl group, a cycloalkyl group having a substituent, an unsubstituted alkenyl group, an alkenyl group having a substituent, an unsubstituted aryl group, an aryl group having a substituent, and an alkylsilyl group. Among these, an unsubstituted aryl group having 6 to 12 carbon atoms and an aryl group having 6 to 12 carbon atoms having a substituent are preferred.

[0057] Examples of the "unsubstituted aryl group having 6 to 12 carbon atoms" include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group. R 2 The number of carbon atoms in the "unsubstituted aryl group having 6 to 12 carbon atoms" represented by the following formula is preferably 6.

[0058] R 2The number of carbon atoms in the "substituted aryl group having 6 to 12 carbon atoms" represented by the formula (I) is preferably 6. Note that this number of carbon atoms refers to the number of carbon atoms in the portion excluding the substituent (the aryl group portion). Therefore, R 2 is a "substituted aryl group having 6 to 12 carbon atoms", R 2 The number of carbon atoms may exceed 12. Examples of the aryl group in the "substituted aryl group having 6 to 12 carbon atoms" include the same groups as those exemplified as the "unsubstituted aryl group having 6 to 12 carbon atoms".

[0059] Examples of the substituent in the "substituted aryl group having 6 to 12 carbon atoms" include halogen atoms such as fluorine atom, chlorine atom and bromine atom; alkoxy groups such as methoxy group and ethoxy group; and the like. The number of atoms of the substituent in the "substituted aryl group having 6 to 12 carbon atoms" is usually 1 to 30, and preferably 1 to 20 (excluding the number of hydrogen atoms).

[0060] When the polysilsesquioxane compound has a repeating unit represented by formula (a-5), the polysilsesquioxane compound has one kind of R 2 and may have two or more R 2 It may have the following structure.

[0061] The content of the repeating unit (T site) represented by the formula (a-4) in the polysilsesquioxane compound can be calculated, for example, by the following formula, when NMR peak assignment and area integration are possible: 29 Si-NMR and 1 It can be determined by measuring H-NMR.

[0062] Polysilsesquioxane compounds are soluble in various organic solvents, such as ketone solvents such as acetone; aromatic hydrocarbon solvents such as benzene; sulfur-containing solvents such as dimethyl sulfoxide; ether solvents such as tetrahydrofuran; ester solvents such as ethyl acetate; halogen-containing solvents such as chloroform; and mixed solvents consisting of two or more of these. Therefore, the polysilsesquioxane compounds in a solution state can be prepared using these solvents. 29 Si-NMR can be measured.

[0063] The repeating unit represented by the formula (a-4) is preferably represented by the following formula (a-6).

[0064] [ka]

[0065] In formula (a-6), G is (R 1 -D), and R 1 and D is R in the formula (a-4). 1 and D. * represents a Si atom, a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms, and at least one of the three * is a Si atom. Examples of the alkyl group having 1 to 10 carbon atoms represented by * include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, an isobutyl group, and a t-butyl group. Multiple *s may be the same or different.

[0066] As shown in formula (a-6), the polysilsesquioxane compound has a partial structure, generally referred to as a T site, in which three oxygen atoms are bonded to a silicon atom and one other group (a group represented by G) is bonded to the silicon atom.

[0067] Furthermore, the polysilsesquioxane compound is a thermosetting compound that can undergo a condensation reaction and / or hydrolysis upon heating. Therefore, at least one of the *'s in the formula (a-6) of the multiple repeating units (T sites) contained in the polysilsesquioxane compound is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, more preferably a hydrogen atom. In addition, when the polysilsesquioxane compound is soluble in the solvent used for measurement, 29 By measuring Si-NMR, it is possible to confirm the presence of a hydrogen atom or an alkyl group having 1 to 10 carbon atoms at * in the formula (a-6) and whether all three * in the formula (a-6) are repeating units each consisting of a Si atom. moreover, 29 When the assignment of Si-NMR peaks and integration of the areas are possible, it is possible to roughly calculate the total number of repeating units in which all three *s in formula (a-6) are Si atoms relative to the total number of repeating units (T sites) represented by formula (a-4) in the polysilsesquioxane compound. The total number of repeating units in which all three *'s in formula (a-6) are Si atoms relative to the total number of repeating units (T sites) represented by formula (a-4) in this polysilsesquioxane compound is preferably 30 to 95 mol %, and more preferably 40 to 90 mol %, from the viewpoint of making it easier to obtain an adhesive paste that gives a cured product with superior heat resistance.

[0068] In the present invention, the polysilsesquioxane compounds can be used singly or in combination of two or more.

[0069] The method for producing the polysilsesquioxane compound is not particularly limited. For example, a method for producing the polysilsesquioxane compound represented by the following formula (a-7)

[0070] [ka]

[0071] (In the formula, R1 and D is R in the formula (a-4). 1 and D. R 3 represents an alkyl group having 1 to 10 carbon atoms, and X 1 represents a halogen atom, and p represents an integer of 0 to 3. 3 , and multiple X 1 may be the same as or different from each other.) A polysilsesquioxane compound can be produced by polycondensing at least one silane compound (1) represented by the following formula: R 3 Examples of the alkyl group having 1 to 10 carbon atoms include the same as those shown as the alkyl group having 1 to 10 carbon atoms represented by * in the formula (a-6). X 1 Examples of the halogen atom include a chlorine atom and a bromine atom.

[0072] Specific examples of the silane compound (1) include alkyltrialkoxysilane compounds such as methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrippropoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltrippropoxysilane, n-propyltributoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, and isooctyltriethoxysilane;

[0073] alkylhalogenoalkoxysilane compounds such as methylchlorodimethoxysilane, methylchlorodiethoxysilane, methyldichloromethoxysilane, methylbromodimethoxysilane, ethylchlorodimethoxysilane, ethylchlorodiethoxysilane, ethyldichloromethoxysilane, ethylbromodimethoxysilane, n-propylchlorodimethoxysilane, n-propyldichloromethoxysilane, n-butylchlorodimethoxysilane, and n-butyldichloromethoxysilane;

[0074] Alkyltrihalogenosilane compounds such as methyltrichlorosilane, methyltribromosilane, ethyltrichlorosilane, ethyltribromosilane, n-propyltrichlorosilane, n-propyltribromosilane, n-butyltrichlorosilane, isobutyltrichlorosilane, n-pentyltrichlorosilane, n-hexyltrichlorosilane, and isooctyltrichlorosilane;

[0075] CF3Si(OCH3)3, CF3CF2Si(OCH3)3, CF3CF2CF2Si(OCH3)3, CF3CF2CF2CF2Si(OCH3)3, CF3CH2CH2Si(OCH3)3, CF3CF2CF2CF2CH2CH2Si(OCH3)3, CF3CF2CF2CF2CF2CF2CH2CH2Si(OCH3)3, CF3CF2CF2CF2CF2CF2CF2CF2CH2CH2Si(OCH3)3, CF3(C6H4)Si(OCH3)3, CF3Si(OCH2CH3)3, CF3CF2Si( fluoroalkyltrialkoxysilane compounds such as OCH2CH3)3, CF3CF2CF2Si(OCH2CH3)3, CF3CF2CF2CF2Si(OCH2CH3)3, CF3CH2CH2Si(OCH2CH3)3, CF3CF2CF2CF2CH2CH2Si(OCH2CH3)3, CF3CF2CF2CF2CF2CF2CH2CH2Si(OCH2CH3)3, CF3CF2CF2CF2CF2CF2CF2CH2CH2Si(OCH2CH3)3, CF3CF2CF2CF2CF2CF2CF2CH2CH2Si(OCH2CH3)3, CF3(C6H4)Si(OCH2CH3)3;

[0076] CF3SiCl(OCH3)2, CF3CF2SiCl(OCH3)2, CF3CF2CF2SiCl(OCH3)2, CF3SiBr(OCH3)2, CF3CF2SiBr(OCH3)2, CF3CF2CF2SiBr(OCH3)2, Fluoroalkyl halogenodialkoxysilane compounds such as CF3CF2CF2CF2SiCl(OCH3)2, CF3CH2CH2SiCl(OCH3)2, CF3CF2CF2CF2CH2CH2SiCl(OCH3)2, CF3CF2CF2CF2CF2CF2CH2CH2SiCl(OCH3)2, CF3CF2CF2CF2CF2CF2CF2CF2CH2CH2SiCl(OCH3)2, CF3(C6H4)SiCl(OCH3)2, CF3SiCl(OCH2CH3)2, CF3CF2SiCl(OCH2CH3)2, CF3CF2CF2SiCl(OCH2CH3)2, CF3CF2CF2CF2SiCl(OCH2CH3)2, CF3CH2CH2SiCl(OCH2CH3)2, CF3CF2CF2CF2CH2CH2SiCl(OCH2CH3)2, CF3CF2CF2CF2CF2CF2CH2CH2SiCl(OCH2CH3)2, CF3CF2CF2CF2CF2CF2CF2CF2CH2CH2SiCl(OCH2CH3)2, CF3(C6H4)SiCl(OCH2CH3)2;

[0077] CF3SiCl2(OCH3), CF3CF2SiCl2(OCH3), CF3CF2CF2SiCl2(OCH3), CF3CF2CF2CF2SiCl2(OCH3), CF3CH2CH2SiCl2(OCH3), CF3CF2CF2CF2CH2CH2SiCl2(OCH3 ), CF3CF2CF2CF2CF2CF2CH2CH2SiCl2(OCH3), CF3CF2CF2CF2CF2CF2CF2CF2CH2CH2SiCl2(OCH3), CF3(C6H4)SiCl2(OCH3), CF3SiCl2(OCH2CH3), CF3CF2SiC Fluoroalkyldihalogenoalkoxysilane compounds such as l2(OCH2CH3), CF3CF2CF2SiCl2(OCH2CH3), CF3CF2CF2CF2SiCl2(OCH2CH3), CF3CF2CF2CF2CH2CH2SiCl2(OCH2CH3), CF3CF2CF2CF2CF2CH2CH2SiCl2(OCH2CH3), CF3CF2CF2CF2CF2CF2CH2CH2SiCl2(OCH2CH3), CF3CF2CF2CF2CF2CF2CF2CH2CH2SiCl2(OCH2CH3), CF3CF2CF2CF2CF2CF2CF2CH2CH2SiCl2(OCH2CH3), CF3(C6H4)SiCl2(OCH2CH3);

[0078] fluoroalkyltrihalogenosilane compounds such as CF3SiCl3, CF3CF2SiCl3, CF3SiBr3, CF3CF2SiBr3, CF3CF2CF2SiCl3, CF3CF2CF2CF2SiCl3, CF3CH2CH2SiCl3, CF3CF2CF2CF2CH2CH2SiCl3, CF3CF2CF2CF2CF2CF2CH2CH2SiCl3, CF3CF2CF2CF2CF2CF2CF2CH2CH2SiCl3, CF3CF2CF2CF2CF2CF2CF2CH2CH2SiCl3, and CF3(C6H4)SiCl3;

[0079] phenyltrialkoxysilane compounds such as phenyltrimethoxysilane, phenyltriethoxysilane, phenyldiethoxymethoxysilane, and phenylethoxydimethoxysilane; phenylhalogenoalkoxysilane compounds such as chlorodimethoxyphenylsilane and chlorodiethoxyphenylsilane; phenyltrihalogenosilane compounds such as phenyltrichlorosilane and phenyltribromosilane; These silane compounds (1) can be used singly or in combination of two or more.

[0080] The method for polycondensing the silane compound (1) is not particularly limited. For example, a method can be used in which a predetermined amount of a polycondensation catalyst is added to the silane compound (1) in a solvent or without a solvent, followed by stirring at a predetermined temperature. More specifically, examples include (a) a method in which a predetermined amount of an acid catalyst is added to the silane compound (1) and the mixture is stirred at a predetermined temperature, (b) a method in which a predetermined amount of a base catalyst is added to the silane compound (1) and the mixture is stirred at a predetermined temperature, and (c) a method in which a predetermined amount of an acid catalyst is added to the silane compound (1) and the mixture is stirred at a predetermined temperature, and then an excess amount of a base catalyst is added to make the reaction system basic, followed by stirring at a predetermined temperature. Among these, methods (a) and (c) are preferred because they allow the desired polysilsesquioxane compound to be obtained efficiently.

[0081] The polycondensation catalyst used may be either an acid catalyst or a base catalyst. Two or more polycondensation catalysts may be used in combination, but it is preferred to use at least an acid catalyst. Examples of the acid catalyst include inorganic acids such as phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, and nitric acid; and organic acids such as citric acid, acetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. Among these, at least one selected from phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, citric acid, acetic acid, and methanesulfonic acid is preferred.

[0082] Examples of the base catalyst include aqueous ammonia; organic bases such as trimethylamine, triethylamine, lithium diisopropylamide, lithium bis(trimethylsilyl)amide, pyridine, 1,8-diazabicyclo[5.4.0]-7-undecene, aniline, picoline, 1,4-diazabicyclo[2.2.2]octane, and imidazole; organic salt hydroxides such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; metal alkoxides such as sodium methoxide, sodium ethoxide, sodium t-butoxide, and potassium t-butoxide; metal hydrides such as sodium hydride and calcium hydride; metal hydroxides such as sodium hydroxide, potassium hydroxide, and calcium hydroxide; metal carbonates such as sodium carbonate, potassium carbonate, and magnesium carbonate; and metal hydrogencarbonates such as sodium hydrogencarbonate and potassium hydrogencarbonate.

[0083] The amount of the polycondensation catalyst used is usually in the range of 0.05 to 10 mol %, preferably 0.1 to 5 mol %, based on the total molar amount of the silane compound (1).

[0084] When a solvent is used during polycondensation, the solvent can be appropriately selected depending on the type of silane compound (1). Examples of suitable solvents include water; aromatic hydrocarbons such as benzene, toluene, and xylene; esters such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and methyl propionate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; and alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, s-butyl alcohol, and t-butyl alcohol. These solvents can be used alone or in combination. Furthermore, when using the above method (c), after polycondensation reaction in an aqueous system in the presence of an acid catalyst, an organic solvent and an excess amount of a basic catalyst (such as aqueous ammonia) can be added to the reaction solution, and further polycondensation reaction can be carried out under basic conditions.

[0085] The amount of the solvent used is usually 0.001 liters or more and 10 liters or less, and preferably 0.01 liters or more and 0.9 liters or less, per mole of the total amount of the silane compound (1).

[0086] The temperature at which the silane compound (1) is polycondensed is usually in the range of 0°C to the boiling point of the solvent used, preferably in the range of 20°C to 100°C. If the reaction temperature is too low, the polycondensation reaction may not proceed sufficiently. On the other hand, if the reaction temperature is too high, it becomes difficult to suppress gelation. The reaction is usually completed within 30 minutes to 30 hours.

[0087] Depending on the type of monomer used, it may be difficult to increase the molecular weight. For example, R 1 is an alkyl group having a fluorine atom, R 1 In such cases, a polysilsesquioxane compound having the desired molecular weight can be more easily obtained by reducing the amount of catalyst and carrying out the reaction under mild conditions for a long period of time.

[0088] After completion of the reaction, neutralization is carried out by adding an aqueous alkali solution such as sodium bicarbonate to the reaction solution when an acid catalyst was used, or by adding an acid such as hydrochloric acid to the reaction solution when a base catalyst was used, and the salt generated during this process is removed by filtration, washing with water, or the like, to obtain the target polysilsesquioxane compound.

[0089] When producing a polysilsesquioxane compound by the above method, the OR of the silane compound (1) 3 or X 1 The portion of the polysilsesquioxane that has not undergone hydrolysis and subsequent condensation reaction remains in the polysilsesquioxane compound.

[0090] When component (A) is, for example, a polysilsesquioxane compound obtained by a polycondensation reaction of silane compound (1), curing proceeds through a condensation reaction, including the reaction with a silane coupling agent described below. Therefore, the adhesive paste of the present invention is different from general heat-curing silicone adhesives that cure through an addition reaction in the presence of a noble metal catalyst such as a platinum catalyst. Therefore, the adhesive paste containing the polysilsesquioxane compound of the present invention contains substantially no precious metal catalyst or contains a small amount of precious metal catalyst. Here, "substantially not containing a precious metal catalyst or containing a small amount of precious metal catalyst" means "not intentionally adding any component that can be interpreted as a precious metal catalyst, and the content of precious metal catalyst relative to the amount of active ingredient in the adhesive paste, converted into the mass of catalytic metal element, is, for example, less than 1 mass ppm." Here, the term "active ingredient" refers to "ingredients excluding the solvent (S) contained in the adhesive paste." From the viewpoints of stable production taking into account formulation variations, storage stability, and the fact that precious metal catalysts are expensive, it is preferable that the adhesive paste contains substantially no precious metal catalyst or has a low content of precious metal catalyst.

[0091] [Thermal conductive filler (T)] The thermally conductive filler (T) (hereinafter sometimes referred to as "component (T)") constituting the adhesive paste of the present invention is a filler having high thermal conductivity. The thermal conductivity of the thermally conductive filler (T) at 25°C is preferably 5 W / (m·K) or more, more preferably 8 W / (m·K) or more and less than 300 W / (m·K), and particularly preferably 10 W / (m·K) or more and less than 100 W / (m·K). By using a thermally conductive filler (T) having a thermal conductivity equal to or higher than the above lower limit, it becomes easier to obtain a cured product having a thermal conductivity of 0.5 W / (m·K) or higher. The thermal conductivity of the thermally conductive filler (T) can be measured, for example, by a laser flash method using a laser flash method thermal constant measurement device (for example, LFA477 Nanoflash manufactured by NETZSCH-Geratebau GmbH).

[0092] The constituent components of the thermally conductive filler (T) are not particularly limited as long as they improve thermal conductivity, and examples thereof include metals, metal oxides, carbides, nitrides, and the like.

[0093] Metal refers to an element belonging to Group 1 (excluding H), Groups 2 to 11, Group 12 (excluding Hg), Group 13 (excluding B), Group 14 (excluding C and Si), Group 15 (excluding N, P, As, and Sb), or Group 16 (excluding O, S, Se, Te, and Po) in the periodic table.

[0094] Examples of metal oxides include magnesium oxide, titanium oxide, zinc oxide, alumina, boehmite, chromium oxide, nickel oxide, copper oxide, zirconium oxide, indium oxide, and composite oxides thereof.

[0096] The thermally conductive filler (T) can be used alone or in combination of two or more. Among these, in the present invention, titanium oxide, alumina, and aluminum nitride are preferred, and alumina is more preferred, because they are easily mixed with component (A), and the cured product obtained by heat curing has high thermal conductivity and is easily able to produce an adhesive paste with excellent adhesive properties.

[0097] The shape of the thermally conductive filler (T) may be any of spherical, chain-like, needle-like, plate-like, flake-like, rod-like, fibrous, etc., but is preferably spherical. Here, "spherical" means "a nearly spherical shape including a true sphere, as well as a polyhedral shape that can approximate a sphere, such as a spheroid, oval, confetti-like, or cocoon-like shape."

[0098] The average particle size of the thermally conductive filler (T) is preferably 0.1 μm or more and less than 5 μm, more preferably 0.2 μm or more and less than 4 μm, even more preferably 0.4 μm or more and less than 3.5 μm, and particularly preferably 0.8 μm or more and less than 3 μm. When the average particle size of component (T) is within the above range, it is easily mixed with component (A), is relatively easy to mix into an adhesive paste, and the cured product obtained by heat curing has high thermal conductivity, making it easier to obtain an adhesive paste with excellent adhesiveness. In addition, the thickness of the adhesive paste coating is usually about 0.5 μm or more and 10 μm or less, and from the viewpoint of being able to mount a semiconductor element horizontally on the applied adhesive paste, it is preferable that the average particle size be less than the above upper limit value. Furthermore, in order for the cured product obtained by heat-curing the adhesive paste of the present invention to exhibit high adhesive strength, it is necessary that the thermally conductive fillers (T) contact each other, but rather that the (T) component and the (A) component contact each other as much as possible. That is, it is preferable that the entire surface of each thermally conductive filler (T) is covered with the (A) component as much as possible. From this perspective, if the average particle size is less than the above-mentioned lower limit, the cohesive force of the thermally conductive filler (T) increases, and the contact areas between the thermally conductive fillers (T) that cannot be covered with the (A) component increase, which may result in a failure to exhibit high adhesive strength. However, if the average particle size is equal to or greater than the above-mentioned lower limit, the area of ​​the thermally conductive filler (T) that can be covered with the (A) component increases, thereby reducing this risk. The average particle size of the thermally conductive filler (T) can be calculated, for example, by measuring the primary particle size through transmission electron microscope observation and image analysis, and by X-ray sedimentation using a particle size distribution analyzer (Sedigraph).

[0099] The volume filling rate of the thermally conductive filler (T) in the solid content of the adhesive paste is preferably 10 vol% or more and less than 80 vol%, more preferably 20 vol% or more and less than 70 vol%, particularly preferably 30 vol% or more and less than 60 vol%. By incorporating component (T) so that the volume filling rate falls within the above range, thermal conductivity is improved, making it easier to obtain a cured product with high thermal conductivity. The volume filling rate can be measured and calculated, for example, as follows: That is, the volume of the (T) component is calculated from the mass and density of the (T) component, and further, the volume of the solid components of the adhesive paste excluding the (T) component is calculated from the mass and density of the solid components of the adhesive paste excluding the (T) component, and the volume filling rate can be calculated using the following formula. Volume filling rate (vol%) = (Volume of component (T) (cm 3 ) / [(T) component volume (cm 3 ) + Volume (cm) of the solid components of the adhesive paste excluding component (T) 3 )] × 100 More specifically, it can be measured and calculated by the methods described in the Examples.

[0100] The content of the (T) component is not particularly limited, but the amount is preferably 30 parts by mass or more and less than 90 parts by mass, more preferably 35 parts by mass or more and less than 85 parts by mass, and even more preferably 40 parts by mass or more and less than 80 parts by mass, per 100 parts by mass of the solid content of the adhesive paste. By using the component (T) in the above range, it becomes easier to obtain a cured product that has high thermal conductivity and excellent adhesiveness when heated at high temperatures.

[0101] Furthermore, the content of the (T) component is not particularly limited, but the amount is preferably 40 parts by mass or more but less than 1,000 parts by mass, more preferably 60 parts by mass or more but less than 900 parts by mass, even more preferably 80 parts by mass or more but less than 800 parts by mass, and particularly preferably 100 parts by mass or more but less than 600 parts by mass, per 100 parts by mass of the solid content of the (A) component. By using the component (T) in the above range, it becomes easier to obtain a cured product that has high thermal conductivity and excellent adhesiveness when heated at high temperatures.

[0102] [Other ingredients] The adhesive paste of the present invention contains a curable organopolysiloxane compound (A) and a thermally conductive filler (T), and may also contain the components shown below.

[0103] (1) Solvent (S) The adhesive paste of the present invention may contain a solvent (S). The solvent (S) is not particularly limited as long as it can dissolve or disperse the components of the adhesive paste of the present invention. The solvent (S) preferably contains an organic solvent having a boiling point of 254° C. or higher (hereinafter, sometimes referred to as "organic solvent (SH)"). Here, the "boiling point" refers to the "boiling point at 1013 hPa" (the same applies throughout this specification). The boiling point of the organic solvent (SH) is preferably 254°C or higher, and more preferably 254°C or higher and 300°C or lower.

[0104] Specific examples of the organic solvent (SH) include tripropylene glycol-n-butyl ether (boiling point 274°C), 1,6-hexanediol diacrylate (boiling point 260°C), diethylene glycol dibutyl ether (boiling point 256°C), triethylene glycol butyl methyl ether (boiling point 261°C), polyethylene glycol dimethyl ether (boiling point 264 to 294°C), tetraethylene glycol dimethyl ether (boiling point 275°C), and polyethylene glycol monomethyl ether (boiling point 290 to 310°C). Among these, tripropylene glycol-n-butyl ether and 1,6-hexanediol diacrylate are preferred as the organic solvent (SH) from the viewpoint of more easily achieving the effects of the present invention. The organic solvent (SH) may be used alone or in combination of two or more kinds.

[0105] The adhesive paste of the present invention may contain a solvent other than the organic solvent (SH). As the solvent other than the organic solvent (SH), a solvent having a boiling point of 100° C. or higher and lower than 254° C. (hereinafter, sometimes referred to as "organic solvent (SL)") is preferred. The organic solvent (SL) is not particularly limited as long as it has a boiling point of 100° C. or higher and lower than 254° C. and is capable of dissolving or dispersing the components of the adhesive paste of the present invention. By using organic solvents (SH) in combination with solvents other than organic solvents (SH), the temperature range in which the adhesive paste is heated to obtain a hardened product can be more precisely adjusted, thereby reducing the impact of heating on optical components and sensor chips that are easily affected by heat.

[0106] Specific examples of the organic solvent (SL) include diethylene glycol monobutyl ether acetate (boiling point 247 ° C), dipropylene glycol-n-butyl ether (boiling point 229 ° C), dipropylene glycol methyl ether acetate (boiling point 209 ° C), diethylene glycol butyl methyl ether (boiling point 212 ° C), dipropylene glycol-n-propyl ether (boiling point 212 ° C), tripropylene glycol dimethyl ether (boiling point 215 ° C), triethylene glycol dimethyl ether (boiling point 216 ° C), diethylene glycol monoethyl ether acetate (boiling point 218 ° C), diethylene glycol-n-butyl ether (boiling point 230 ° C), ethylene glycol monophenyl ether (boiling point 245 ° C), Examples of the methyl ether include tripropylene glycol methyl ether (boiling point 242 ° C), propylene glycol phenyl ether (boiling point 243 ° C), triethylene glycol monomethyl ether (boiling point 249 ° C), benzyl alcohol (boiling point 204.9 ° C), phenethyl alcohol (boiling point 219 to 221 ° C), ethylene glycol monobutyl ether acetate (boiling point 192 ° C), ethylene glycol monoethyl ether (boiling point 134.8 ° C), ethylene glycol monomethyl ether (boiling point 124.5 ° C), propylene glycol monomethyl ether acetate (boiling point 146 ° C), cyclopentanone (boiling point 130 ° C), cyclohexanone (boiling point 157 ° C), cycloheptanone (boiling point 180 ° C), cyclooctanone (boiling point 195 to 197 ° C), cyclohexanol (boiling point 161 ° C), and cyclohexadienone (boiling point 104 to 104.5 ° C). Among these, as the organic solvent (SL), glycol-based solvents are preferred from the viewpoint of facilitating good mixing of the active ingredient, and diethylene glycol monobutyl ether acetate and dipropylene glycol-n-butyl ether are preferred, with diethylene glycol monobutyl ether acetate being more preferred.

[0107] When an organic solvent (SH) and an organic solvent (SL) are used in combination, specifically, a combination of tripropylene glycol-n-butyl ether (solvent (SH)) and diethylene glycol monobutyl ether acetate (solvent (SL)), a combination of 1,6-hexanediol diacrylate (solvent (SH)) and diethylene glycol monobutyl ether acetate (solvent (SL)), a combination of tripropylene glycol-n-butyl ether (solvent (SH)) and dipropylene glycol-n-butyl ether (solvent (SL)), and a combination of 1,6-hexanediol diacrylate (solvent (SH)) and dipropylene glycol-n-butyl ether (solvent (SL)) are preferred.

[0108] The adhesive paste of the present invention preferably contains the solvent (S) in an amount such that the solid content concentration is preferably 50% by mass or more and 99% by mass or less, more preferably 70% by mass or more and 97% by mass or less. When the solid content concentration is within this range, the active ingredient can be easily mixed well, and the adhesive paste can be easily filled into a syringe and applied. Here, "excellent workability in the step of filling a syringe with adhesive paste" means "ability to fill an appropriate amount into a syringe without air bubbles." Furthermore, when die bonding is performed, it is possible to prevent the occurrence of voids between the adhesive paste and the substrate or the like to which it is to be bonded, thereby increasing the reliability of the package.

[0109] (2) Silane coupling agent (B) The adhesive paste of the present invention may contain a silane coupling agent as component (B). Examples of the silane coupling agent include a silane coupling agent (B1) having a nitrogen atom in the molecule (hereinafter, sometimes referred to as "silane coupling agent (B1)") and a silane coupling agent (B2) having an acid anhydride structure in the molecule (hereinafter, sometimes referred to as "silane coupling agent (B2)").

[0110] The adhesive paste containing the silane coupling agent (B1) has excellent workability in the application step, and also has excellent curing properties due to the condensation reaction with the component (A) when heated, giving a cured product that is excellent in adhesion, heat resistance, and crack suppression properties when heated at high temperatures. Here, "excellent crack suppression in the cured product" means "when the adhesive paste is heated to obtain a cured product, cracks in the cured product due to temperature changes do not occur."

[0111] The silane coupling agent (B1) is not particularly limited as long as it is a silane coupling agent having a nitrogen atom in the molecule. Examples thereof include trialkoxysilane compounds represented by the following formula (b-1), dialkoxyalkylsilane compounds or dialkoxyarylsilane compounds represented by the following formula (b-2), etc.

[0112] [ka]

[0113] In the above formula, R a represents an alkoxy group having 1 to 6 carbon atoms, such as a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, or a t-butoxy group. a They may be the same or different. R b represents an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a t-butyl group; or an aryl group having or having no substituent, such as a phenyl group, a 4-chlorophenyl group, a 4-methylphenyl group, or a 1-naphthyl group.

[0114] R c represents an organic group having a nitrogen atom and having 1 to 10 carbon atoms. c may further be bonded to another group containing a silicon atom. R c Specific examples of the organic group having 1 to 10 carbon atoms include an N-2-(aminoethyl)-3-aminopropyl group, a 3-aminopropyl group, an N-(1,3-dimethyl-butylidene)aminopropyl group, a 3-ureidopropyl group, and an N-phenyl-aminopropyl group.

[0115] Among the compounds represented by the above formula (b-1) or (b-2), R c In the case where the group (I) is an organic group bonded to another group containing a silicon atom, examples of the compound include those that bond to another silicon atom via an isocyanurate skeleton to form an isocyanurate-based silane coupling agent, and those that bond to another silicon atom via a urea skeleton to form a urea-based silane coupling agent.

[0116] Among these, as the silane coupling agent (B1), isocyanurate-based silane coupling agents and urea-based silane coupling agents are preferred because they tend to give cured products with higher adhesive strength, and moreover, those having four or more alkoxy groups bonded to silicon atoms in the molecule are preferred. "Having four or more alkoxy groups bonded to a silicon atom" means that the total number of alkoxy groups bonded to the same silicon atom and alkoxy groups bonded to different silicon atoms is four or more.

[0117] An example of an isocyanurate-based silane coupling agent having four or more alkoxy groups bonded to a silicon atom is a compound represented by the following formula (b-3), and an example of a urea-based silane coupling agent having four or more alkoxy groups bonded to a silicon atom is a compound represented by the following formula (b-4).

[0118] [ka]

[0119] In the formula, R a represents R in the formulas (b-1) and (b-2). a Each of t1 to t5 independently represents an integer of 1 to 10, preferably an integer of 1 to 6, and particularly preferably 3.

[0120] Specific examples of the compound represented by formula (b-3) include 1,3,5-N-tris[(tri(C1-6)alkoxy)silyl(C1-10)alkyl]isocyanurates such as 1,3,5-N-tris(3-trimethoxysilylpropyl)isocyanurate, 1,3,5-N-tris(3-triethoxysilylpropyl)isocyanurate, 1,3,5-N-tris(3-tri-i-propoxysilylpropyl)isocyanurate, and 1,3,5-N-tris(3-tributoxysilylpropyl)isocyanurate; 1,3,5-N-tris(3-dimethoxymethylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-dimethoxyethylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-dimethoxy-i-propylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-dimethoxy-n-propylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-dimethoxyphenylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-diethoxy 1,3,5-N-tris(3-diethoxyethylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-diethoxy-i-propylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-diethoxy-n-propylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-diethoxyphenylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-di-i-propoxymethylsilylpropyl)isocyanurate 1,3,5-N-tris(3-di-i-propoxyethylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-di-i-propoxyi-propylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-di-i-propoxyn-propylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-di-i-propoxyphenylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-dibutoxymethylsilylpropyl)isocyanurate, 1,3, Examples of 1,3,5-N-tris[(di(C1-C6)alkoxy)silyl(C1-C10)alkyl]isocyanurates include 5-N-tris(3-dibutoxyethylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-dibutoxyi-propylsilylpropyl)isocyanurate, 1,3,5-N-tris(3-dibutoxyn-propylsilylpropyl)isocyanurate, and 1,3,5-N-tris(3-dibutoxyphenylsilylpropyl)isocyanurate.

[0121] Specific examples of the compound represented by formula (b-4) include N,N'-bis[(tri(C1-C6)alkoxysilyl)(C1-C10)alkyl]ureas such as N,N'-bis(3-trimethoxysilylpropyl)urea, N,N'-bis(3-triethoxysilylpropyl)urea, N,N'-bis(3-tripropoxysilylpropyl)urea, N,N'-bis(3-tributoxysilylpropyl)urea, and N,N'-bis(2-trimethoxysilylethyl)urea; N,N'-bis[(di(C1-6)alkoxy(C1-6)alkylsilyl(C1-10)alkyl)ureas such as N,N'-bis(3-dimethoxymethylsilylpropyl)urea, N,N'-bis(3-dimethoxyethylsilylpropyl)urea, and N,N'-bis(3-diethoxymethylsilylpropyl)urea; N,N'-bis[(di(C1-6)alkoxy(C6-20)arylsilyl(C1-10)alkyl)ureas such as N,N'-bis(3-dimethoxyphenylsilylpropyl)urea and N,N'-bis(3-diethoxyphenylsilylpropyl)urea; and the like. The silane coupling agent (B1) can be used alone or in combination of two or more.

[0122] Among these, as the silane coupling agent (B1), it is preferable to use 1,3,5-N-tris(3-trimethoxysilylpropyl)isocyanurate, 1,3,5-N-tris(3-triethoxysilylpropyl)isocyanurate (hereinafter, the two are referred to as "isocyanurate compounds"), N,N'-bis(3-trimethoxysilylpropyl)urea, N,N'-bis(3-triethoxysilylpropyl)urea (hereinafter, the two are referred to as "urea compounds"), and combinations of the above-mentioned isocyanurate compounds and urea compounds, and it is more preferable to use isocyanurate compounds.

[0123] When the isocyanurate compound and the urea compound are used in combination, the mass ratio of the isocyanurate compound to the urea compound is preferably 100:1 to 100:200, more preferably 100:10 to 100:110. By using the isocyanurate compound and the urea compound in combination in such a ratio, an adhesive paste can be obtained that gives a cured product with higher adhesive strength and more excellent heat resistance.

[0124] When the adhesive paste of the present invention contains a silane coupling agent (B1) [component (B1)], the content of component (B1) is not particularly limited, but the amount is preferably 0.7 parts by mass or more and less than 15 parts by mass, more preferably 1 part by mass or more and less than 13 parts by mass, even more preferably 1.3 parts by mass or more and less than 11 parts by mass, and particularly preferably 1.5 parts by mass or more and less than 9 parts by mass, per 100 parts by mass of the solid content of the adhesive paste. By using component (B1) in the above range, the effects of adding component (B1) can be more fully realized, and a cured product with a thermal conductivity of 0.5 W / (m·K) or higher can be more easily obtained.

[0125] The adhesive paste containing the silane coupling agent (B2) has excellent workability in the application step and gives a cured product that is superior in adhesiveness and heat resistance when heated at high temperatures.

[0126] Examples of the silane coupling agent (B2) include tri(C1-C6)alkoxysilyl(C2-C8)alkyl succinic anhydrides, such as 2-(trimethoxysilyl)ethyl succinic anhydride, 2-(triethoxysilyl)ethyl succinic anhydride, 3-(trimethoxysilyl)propyl succinic anhydride, and 3-(triethoxysilyl)propyl succinic anhydride; Di(C1-C6)alkoxymethylsilyl(C2-C8)alkyl succinic anhydrides such as 2-(dimethoxymethylsilyl)ethyl succinic anhydride; (C1-C6)alkoxydimethylsilyl(C2-C8)alkyl succinic anhydrides such as 2-(methoxydimethylsilyl)ethyl succinic anhydride;

[0127] Trihalogenosilyl (C2-C8) alkyl succinic anhydrides such as 2-(trichlorosilyl)ethyl succinic anhydride and 2-(tribromosilyl)ethyl succinic anhydride; Dihalogenomethylsilyl (C2-C8) alkyl succinic anhydrides such as 2-(dichloromethylsilyl)ethyl succinic anhydride; halogenodimethylsilyl (having 2 to 8 carbon atoms) alkyl succinic anhydrides such as 2-(chlorodimethylsilyl)ethyl succinic anhydride; and the like. The silane coupling agent (B2) can be used alone or in combination of two or more kinds.

[0128] Among these, as the silane coupling agent (B2), tri(C1-6)alkoxysilyl(C2-8)alkyl succinic anhydride is preferred, and 3-(trimethoxysilyl)propyl succinic anhydride or 3-(triethoxysilyl)propyl succinic anhydride is particularly preferred.

[0129] When the adhesive paste of the present invention contains a silane coupling agent (B2) [component (B2)], the content of component (B2) is not particularly limited, but the amount is preferably 0.05 parts by mass or more and less than 5 parts by mass, more preferably 0.1 parts by mass or more and less than 3 parts by mass, even more preferably 0.2 parts by mass or more and less than 2 parts by mass, and particularly preferably 0.3 parts by mass or more and less than 1.5 parts by mass, per 100 parts by mass of the solid content of the adhesive paste. By using component (B2) within the above range, the effects of adding component (B2) can be more fully realized, and a cured product with a thermal conductivity of 0.5 W / (m·K) or higher can be more easily obtained.

[0130] Furthermore, when the adhesive paste of the present invention contains component (B), the content of component (B) is not particularly limited, but the amount is preferably 0.7 parts by mass or more and less than 20 parts by mass, more preferably 1 part by mass or more and less than 15 parts by mass, even more preferably 1.3 parts by mass or more and less than 12 parts by mass, and particularly preferably 1.5 parts by mass or more and less than 9 parts by mass, per 100 parts by mass of the solid content of the adhesive paste. By using component (B) within the above range, the effects of adding component (B) can be more fully realized, and a cured product with a thermal conductivity of 0.5 W / (m·K) or higher can be more easily obtained.

[0131] (3) Other additives The adhesive paste of the present invention may contain a component (C) other than the above components (A), (T) and (B) as long as it does not impair the object of the present invention. Examples of the component (C) include antioxidants, ultraviolet absorbers, and light stabilizers.

[0132] The antioxidant is added to prevent oxidative deterioration during heating. Examples of the antioxidant include phosphorus-based antioxidants, phenol-based antioxidants, and sulfur-based antioxidants.

[0133] Examples of phosphorus-based antioxidants include phosphites and oxaphosphaphenanthrene oxides. Examples of the phenol-based antioxidant include monophenols, bisphenols, and polymeric phenols. Examples of sulfur-based antioxidants include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate.

[0134] These antioxidants can be used either individually or in combination of two or more. The amount of antioxidant used is usually 10% by mass or less based on the component (A).

[0135] The ultraviolet absorber is added for the purpose of improving the light resistance of the resulting adhesive paste. Examples of ultraviolet absorbers include salicylic acids, benzophenones, benzotriazoles, and hindered amines. These ultraviolet absorbents may be used alone or in combination of two or more. The amount of the ultraviolet absorber used is usually 10% by mass or less based on the component (A).

[0136] The light stabilizer is added for the purpose of improving the light resistance of the resulting adhesive paste. Examples of light stabilizers include hindered amines such as poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidine)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidine)imino}]. These light stabilizers may be used either individually or in combination of two or more. The total amount of component (C) used is usually 20 mass % or less relative to component (A).

[0137] The adhesive paste of the present invention can be produced, for example, by a production method including the following steps (AI) and (AII). Step (AI): A step of polycondensing at least one compound represented by the above formula (a-7) in the presence of a polycondensation catalyst to obtain a polysilsesquioxane compound. Step (AII): A step of dissolving the polysilsesquioxane compound obtained in step (AI) in a solvent (S) and adding a thermally conductive filler (T) to the resulting solution containing the polysilsesquioxane compound.

[0138] In step (AI), at least one compound represented by formula (a-7) is polycondensed in the presence of a polycondensation catalyst to obtain a polysilsesquioxane compound, and examples thereof include the methods exemplified in the section 1) Adhesive Paste. Examples of the solvent (S) and thermally conductive filler (T) used in step (AII) include the same solvents (S) and thermally conductive fillers (T) exemplified in the section 1) Adhesive Paste.

[0139] In step (AII), examples of the method for dissolving the polysilsesquioxane compound in the solvent (S) include a method in which the polysilsesquioxane compound, the thermally conductive filler (T), and, if desired, the components (B) and (C), are mixed with the solvent (S), degassed, and then dissolved. The mixing method and degassing method are not particularly limited, and known methods can be used. The order of mixing is not particularly limited. According to the production method including the above steps (AI) and (AII), the adhesive paste of the present invention can be produced efficiently and simply.

[0140] In the present invention, the adhesive paste is heated to volatilize the solvent (S) and harden, thereby obtaining a hardened product. The heating temperature during curing is usually 100 to 190° C., and preferably 120 to 190° C. The heating time during curing is usually 30 minutes to 10 hours, preferably 30 minutes to 5 hours, and more preferably 30 minutes to 3 hours.

[0141] The adhesive paste of the present invention has the above-mentioned properties and can therefore be suitably used as an adhesive for semiconductor element fixing materials.

[0142] 2) Method of using adhesive paste and method of manufacturing semiconductor device using adhesive paste The adhesive paste of the present invention semiconductor The method for producing a semiconductor device using the adhesive for an element fixing material is a method including the following steps (BI) and (BII). Step (BI): A step of applying adhesive paste to one or both of the adhesive surfaces of the semiconductor element and the supporting substrate and pressing them together. Step (BII): A step of heating and hardening the adhesive paste of the pressure-bonded product obtained in Step (BI) to fix the semiconductor element to the support substrate.

[0143] Examples of semiconductor elements include optical semiconductor elements such as light-emitting elements such as lasers and light-emitting diodes (LEDs), light-receiving elements such as solar cells, transistors, sensors such as temperature sensors and pressure sensors, integrated circuits, etc. Among these, optical semiconductor elements are preferred from the viewpoint that the effects of using the adhesive paste of the present invention can be more suitably exhibited.

[0144] Materials for the support substrate to which the semiconductor element is bonded include glasses such as soda lime glass and heat-resistant hard glass; ceramics; sapphire; metals such as iron, copper, aluminum, gold, silver, platinum, chromium, titanium and alloys of these metals, and stainless steel (SUS302, SUS304, SUS304L, SUS309, etc.); and synthetic resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, ethylene-vinyl acetate copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyether ether ketone, polyethersulfone, polyphenylene sulfide, polyetherimide, polyimide, polyamide, acrylic resin, norbornene resin, cycloolefin resin, and glass epoxy resin.

[0145] The adhesive paste of the present invention is preferably filled in a syringe. The adhesive paste is filled in a syringe, which provides excellent workability in the application process. The syringe may be made of any of synthetic resin, metal, and glass, but is preferably made of synthetic resin. The capacity of the syringe is not particularly limited and may be determined appropriately according to the amount of adhesive paste to be filled or applied. Alternatively, commercially available syringes may be used, such as the SS-01T series (manufactured by TERUMO Corporation) and the PSY series (manufactured by Musashi Engineering Co., Ltd.).

[0146] In the method for manufacturing a semiconductor device of the present invention, a syringe filled with adhesive paste descends vertically to approach a support substrate, and after a predetermined amount of adhesive paste is dispensed from the tip of the syringe, the syringe rises and moves away from the support substrate, and the support substrate moves sideways. This operation is then repeated to continuously apply adhesive paste to the support substrate. After that, a semiconductor element is mounted on the applied adhesive paste and pressure-bonded to the support substrate.

[0147] The amount of adhesive paste to be applied is not particularly limited as long as it is an amount that can firmly bond the semiconductor element and the supporting substrate to be bonded by curing. Typically, the amount is such that the thickness of the adhesive paste coating is 0.5 μm to 5 μm, preferably 1 μm to 3 μm.

[0148] The adhesive paste in the resulting pressure-bonded product is then heated and hardened, thereby fixing the semiconductor element to the support substrate. The heating temperature and heating time are as explained in the section 1) Adhesive Paste.

[0149] The semiconductor device obtained by the semiconductor device manufacturing method of the present invention has a semiconductor element well mounted on an adhesive paste and fixed with high adhesive strength in the wire bonding process, and thermal degradation is reduced or prevented. [Example]

[0150] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. In each example, parts and percentages are by weight unless otherwise specified.

[0151] [Average molecular weight measurement] The mass average molecular weight (Mw) and number average molecular weight (Mn) of the curable organopolysiloxane compound (A) obtained in the Production Examples were measured using the following apparatus under the following conditions, expressed as standard polystyrene equivalent values. Device name: HLC-8220GPC, manufactured by Tosoh Corporation Column: TSKgel GMHXL, TSKgel GMHXL, and TSKgel 2000HXL connected in sequence Solvent: tetrahydrofuran Injection volume: 80μl Measurement temperature: 40℃ Flow rate: 1ml / min Detector: differential refractometer

[0152] [IR spectrum measurement] The IR spectrum of the curable organopolysiloxane compound (A) obtained in the Production Examples was measured using a Fourier transform infrared spectrophotometer (Spectrum 100, manufactured by PerkinElmer).

[0153] (Production Example 1) A 300 ml eggplant-shaped flask was charged with 71.37 g (400 mmol) of methyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), and then an aqueous solution prepared by dissolving 0.10 g of 35% hydrochloric acid (0.25 mol % relative to the total amount of silane compounds) in 21.6 ml of distilled water was added with stirring. The entire volume was stirred at 30°C for 2 hours, then heated to 70°C and stirred for 5 hours. After that, the reaction solution was returned to room temperature (23°C), and 140 g of propyl acetate was added. To this was added 0.12 g of 28% aqueous ammonia (0.5 mol % based on the total amount of the silane compounds) while stirring the entire volume, and the temperature was raised to 70° C., followed by further stirring for 3 hours. Purified water was added to the reaction mixture, and the layers were separated. This procedure was repeated until the pH of the aqueous layer reached 7.0. The organic layer was concentrated using an evaporator, and the concentrate was dried in vacuo to obtain 55.7 g of curable organopolysiloxane compound (A1). The curable organopolysiloxane compound (A1) had a mass average molecular weight (Mw) of 7,800 and a molecular weight distribution (Mw / Mn) of 4.52. The IR spectrum data of the curable organopolysiloxane compound (A1) is shown below. Si-CH3: 1272 cm -1 ,1409cm -1 , Si-O: 1132 cm -1

[0154] The compounds used in the examples and comparative examples are shown below. [Component (A)] Curable organopolysiloxane compound (A1): Organopolysiloxane compound obtained in Production Example 1

[0155] [(T) component] Thermally conductive filler (T1): Titanium oxide (manufactured by Ishihara Sangyo Kaisha, product name "CR-90-2", average particle size: 0.25 μm, thermal conductivity: 8 W / (m·K)) Thermally conductive filler (T2): Alumina (manufactured by Sumitomo Chemical Co., Ltd., product name "AA-03F", average particle size: 0.25 μm, thermal conductivity: 30 W / (m·K)) Thermally conductive filler (T3): Alumina (manufactured by Sumitomo Chemical Co., Ltd., product name "AA-04", average particle size: 0.50 μm, thermal conductivity: 30 W / (m·K)) Thermally conductive filler (T4): Alumina (manufactured by Sumitomo Chemical Co., Ltd., product name "AA-2", average particle size: 2.1 μm, thermal conductivity: 30 W / (m·K)) Thermally conductive filler (T5): Magnesium carbonate (manufactured by Konoshima Chemical Co., Ltd., product name "MS-S", average particle size: 1.2 μm, thermal conductivity: 15 W / (m·K)) Thermally conductive filler (T6): Aluminum nitride (Showa Denko K.K., product name "AlN0201", average particle size: 2.0 μm, thermal conductivity: 285 W / (m·K))

[0156] [Solvent (S)] A mixed solvent of diethylene glycol monobutyl ether acetate (BDGAC) (SL) (manufactured by Tokyo Chemical Industry Co., Ltd., boiling point: 247°C) and tripropylene glycol n-butyl ether (TPnB) (SH) (manufactured by The Dow Chemical Company, boiling point: 274°C) [BDGAC:TPnB = 40:60 (mass ratio)] [(B) component] Silane coupling agent (B1): 1,3,5-N-tris[3-(trimethoxysilyl)propyl]isocyanurate (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-9659") Silane coupling agent (B2): 3-(trimethoxysilyl)propylsuccinic anhydride (manufactured by Shin-Etsu Chemical Co., Ltd., product name "X-12-967C")

[0157] Example 1 To 100 parts of the curable organopolysiloxane compound (A1), 73 parts of the solvent (S), 160 parts of the thermally conductive filler (T1), 30 parts of the silane coupling agent (B1), and 3 parts of the silane coupling agent (B2) were added, and the entire mixture was thoroughly mixed and degassed to obtain adhesive paste 1 with a solids concentration of 80%.

[0158] (Examples 2 to 8, Comparative Examples 1 to 4) Adhesive pastes 2 to 8 and 1r to 4r were obtained in the same manner as in Example 1, except that the types and blending ratios of the compounds (each component) were changed to those shown in Table 1 below.

[0159] The adhesive pastes 1 to 8 and 1r to 4r obtained in the examples and comparative examples were subjected to the following tests. The results are shown in Tables 1 and 2.

[0160] [Volume filling rate calculation] The volume of the (T) component was calculated from the mass and density of the (T) component, and further, the volume of the components excluding the (T) component in the solid content of the adhesive paste was calculated from the mass and density of the components excluding the (T) component in the solid content of the adhesive paste, and the volume filling rate of the (T) component in the solid content of the adhesive paste was calculated using the following formula. Volume filling rate (vol%) = (Volume of component (T) (cm 3 ) / [(T) component volume (cm 3 ) + Volume (cm) of the solid components of the adhesive paste excluding component (T) 3 )]) × 100 The density of the solid components of the adhesive paste excluding component (T) is 1.2 g / cm 3 The density of component (T) is calculated based on the Chemical Dictionary (Tokyo Kagaku Dojin, 1st edition, published October 20, 1989), where the density of titanium oxide (component (T1)) is 4.17 g / cm. 3 , the density of alumina (component (T2), component (T3) and component (T4)) is 4.0 g / cm3 , the density of magnesium carbonate (component (T5)) is 3.04 g / cm 3 , the density of aluminum nitride (component (T6)) is 3.05 g / cm 3 was used.

[0161] [Thermal conductivity measurement] The adhesive pastes obtained in the examples and comparative examples were poured into Teflon® frames measuring 10 mm long x 10 mm wide x 0.2 mm high, and then heat-treated at 120°C for 4 hours to harden, yielding test pieces with smooth surfaces. The thermal diffusivity of these test pieces was then measured by the temperature wave method using a thermal diffusivity measuring device (ai-Phase Mobile 1, manufactured by ai-Phase Corporation). Furthermore, the specific heat of the components constituting the cured product obtained by heat-hardening the adhesive paste, excluding the thermally conductive filler (T), was 1 J / (g·K) and the density was 1.2 g / cm. 3 The thermal conductivity was calculated using the following formula. Thermal conductivity (W / (m·K)) = Thermal diffusivity (m 2 / s) × specific heat (J / (g K)) × density (g / cm 3 ) x 10 6

[0162] [Adhesion strength evaluation] A square with a side length of 1 mm (area 1 mm 2 The adhesive pastes obtained in the Examples and Comparative Examples were applied to the mirror surface of a silicon chip (100 mm thick) and left to stand under standard conditions (temperature: 23°C ± 1°C, relative humidity: 50 ± 5%). After 5 minutes, the applied surface was placed on an adherend (electroless silver-plated copper plate (average roughness of the silver-plated surface, Ra: 0.025 μm)) and pressed so that the adhesive paste thickness after pressing was approximately 3 μm. The paste was then heat-treated at 170°C for 2 hours to harden the adhesive, yielding an adherend with a test piece attached. The adherend with the test piece attached was then placed on the measurement stage of a bond tester (Daisi, Series 4000) at 100°C for 60 seconds. A horizontal (shear) stress was applied to the adhesive surface from a height of 100 μm from the adherend at a speed of 200 μm / s, and the adhesive strength (N / mm□) between the test piece and the adherend at 100°C was measured.

[0163] [Evaluation of thermal degradation of semiconductor elements] The adhesive pastes obtained in the examples and comparative examples were applied to an optical element fixing substrate (OP-04 manufactured by Enomoto Co., Ltd.), and an optical semiconductor element (B2020BCI0 manufactured by Genelite) was pressed onto the substrate so that the adhesive paste thickness after pressing was approximately 3 μm. The paste was then cured by heat treatment at 170°C for 2 hours. Two wires were then bonded between the optical semiconductor element and the optical element fixing substrate to establish electrical continuity, yielding a test piece for evaluating thermal degradation. The optical semiconductor element in the test piece for evaluating thermal degradation was then irradiated with a current of 250 mA, and the initial luminous flux and the luminous flux after 1000 hours of power application were measured using a measuring device (T3Ster / TeraLED manufactured by Mentor Graphics). From the measured luminous flux, the luminous flux maintenance rate (%) [[luminous flux (lm) after 1000 hours of power-on time / initial luminous flux (lm)] × 100] was calculated, and the thermal degradation of the semiconductor element was evaluated according to the following criteria. Excellent: Luminous flux maintenance rate was 97% or more. Good: Luminous flux maintenance rate was 95% or more but less than 97%. Pass: Luminous flux maintenance rate was 93% or more but less than 95%. Unacceptable: Luminous flux maintenance was less than 93%.

[0164] [Wire bonding evaluation] A square with a side length of 1 mm (area 1 mm 2The adhesive pastes obtained in the Examples and Comparative Examples were applied to the mirror surface of a silicon chip (#2000 grinding, 200 μm thick), and the applied surface was pressed onto an adherend (electroless silver-plated copper plate (average roughness of the silver-plated surface, Ra: 0.025 μm)) so that the adhesive paste thickness after pressing was approximately 3 μm. The paste was then heat-treated at 170°C for 2 hours to harden, yielding an adherend with a test piece. Then, using a wire bonder (Shinkawa Co., Ltd.; UTC-2000 Super (φ25 μm, Au wire, K&S Co., Ltd.)), bonding was performed using four wires between the silicon chip and the copper plate at 170°C, 0.01 seconds, a load of 25 gf, and an ultrasonic output of 30 PLS. The test piece (cured adhesive paste) was observed for peeling from the electroless silver-plated copper plate. This evaluation and observation was repeated for 20 chips for each adhesive paste obtained in the Examples and Comparative Examples, and the results were evaluated according to the following criteria. Good: Of the 20 chips, peeling or misalignment occurred in 0 chips. Pass: Peeling or misalignment occurred in 1 to 3 of the 20 chips. Unacceptable: Peeling or misalignment occurred in 4 or more of the 20 chips.

[0165] [Table 1]

[0166] [Table 2]

[0167] The following can be seen from Tables 1 and 2: The adhesive pastes 1 to 8 of Examples 1 to 8 have high thermal conductivity when heated and cured, and the cured products obtained by heating at high temperatures have excellent adhesive properties. Therefore, when the cured products obtained by heating the adhesive pastes 1 to 8 are used, thermal degradation of the semiconductor element can be reduced, and peeling of the semiconductor element can be reduced or prevented during the wire bonding process. Since alumina has a higher thermal conductivity than titanium oxide, adhesive paste 2 containing alumina (T2) as component (T) can produce a cured product with higher thermal conductivity than adhesive paste 1 containing titanium oxide (T1). Therefore, when the cured product obtained by heat-curing adhesive paste 2 is used, thermal degradation of semiconductor elements can be further reduced or prevented. On the other hand, titanium oxide is more easily mixed with component (A) produced in Production Example 1 than alumina, and the area of ​​the thermally conductive filler (T) that can cover component (A) is larger. Therefore, adhesive paste 1 can produce a cured product with better adhesiveness when heated at high temperatures compared to adhesive paste 2 (Examples 1 and 2). That is, by selecting the type of thermally conductive filler (T), an optimum adhesive paste can be obtained taking into consideration the type of semiconductor element, the temperature at which the adhesive paste is cured, and the like.

[0168] An adhesive paste containing a thermally conductive filler (T) with a large average particle size can produce a cured product with higher thermal conductivity, and the cured product obtained by heating at high temperatures has excellent adhesive strength. Therefore, when a cured product obtained by heat-curing an adhesive paste containing a thermally conductive filler (T) with a large average particle size is used, peeling of the semiconductor element can be further reduced or prevented in the wire bonding process (Examples 2 to 4). Furthermore, adhesive pastes 5 and 6, which have a high content of component (T) per 100 parts by mass of the solid content of the adhesive paste, can produce cured products with higher thermal conductivity than adhesive paste 4, which has a low content of component (T). Therefore, when cured products obtained by heat-curing adhesive pastes 5 and 6 are used, thermal degradation of semiconductor elements can be further reduced or prevented. On the other hand, adhesive paste 6 has a high content of component (T), but the contents of components (B) and (B1) per 100 parts by mass of the solid content of the adhesive paste are low, so the adhesiveness of the cured products obtained by heating at high temperatures is slightly reduced (Examples 4 to 6). Even adhesive pastes containing a thermally conductive filler (T2) with a small average particle size can produce cured products with high thermal conductivity when they contain a large amount of the filler (T2). Furthermore, adhesive paste 7 and 4r contain a relatively large amount of components (B) and (B1) per 100 parts by mass of the solid content of the adhesive paste, so that the cured product obtained by heating the adhesive paste at a high temperature has better adhesiveness (Example 7 and Comparative Example 4). Even with adhesive paste 8 containing aluminum nitride (T6) as the (T) component, a cured product with high thermal conductivity can be obtained, similar to adhesive paste 4 containing alumina (T4), and the cured product obtained by heating at high temperatures has excellent adhesion (Examples 4 and 8). That is, by selecting the content of the thermally conductive filler (T), an optimum adhesive paste can be obtained taking into consideration the type of semiconductor element, the temperature at which the adhesive paste is cured, and the like.

[0169] On the other hand, the adhesive paste 1r of Comparative Example 1 is an adhesive paste that does not contain a thermally conductive filler (T), and therefore the thermal conductivity of the cured product obtained by heat curing is low. Therefore, when this cured product was used, thermal degradation of the semiconductor element was observed. The adhesive paste 2r of Comparative Example 2 had a low content of component (T) per 100 parts by mass of the solid content of the adhesive paste, and therefore the thermal conductivity of the cured product obtained by heat curing was low. Therefore, when this cured product was used, thermal degradation of the semiconductor element was observed. The adhesive paste 3r of Comparative Example 3 contains magnesium carbonate as the thermally conductive filler (T), which is relatively difficult to mix with the component (A) prepared in Production Example 1. As a result, the area of ​​the thermally conductive filler (T) that can cover the component (A) is small, and the cured product obtained by heating the adhesive paste at high temperatures does not exhibit sufficient adhesive strength. Therefore, when this cured product was used, peeling of the semiconductor element was observed during the wire bonding process.

Claims

1. An adhesive paste containing a curable organopolysiloxane compound (A), a thermally conductive filler (T), and a silane coupling agent (B), the curable organopolysiloxane compound (A) is a polysilsesquioxane compound, the silane coupling agent (B) contains an isocyanurate-based silane coupling agent or a urea-based silane coupling agent (B1) and a silane coupling agent having an acid anhydride structure (B2); The silane coupling agent (B) is contained in an amount of 1.5 parts by mass or more and less than 20 parts by mass per 100 parts by mass of the solid content of the adhesive paste, The thermal conductivity of the cured product obtained by heating and curing the adhesive paste at 120°C for 4 hours is 0.5 W / (m K) or more, The adhesive paste has an adhesive strength of 5 N / mm□ or more between the cured product obtained by heating and curing the adhesive paste at 170°C for 2 hours and a silver-plated copper plate at 100°C.

2. An adhesive paste containing a curable organopolysiloxane compound (A), a thermally conductive filler (T), and a silane coupling agent (B), the curable organopolysiloxane compound (A) is a polysilsesquioxane compound, the silane coupling agent (B) contains an isocyanurate-based silane coupling agent or a urea-based silane coupling agent (B1) and a silane coupling agent having an acid anhydride structure (B2); the thermally conductive filler (T) is titanium oxide, The thermal conductivity of the cured product obtained by heating and curing the adhesive paste at 120°C for 4 hours is 0.5 W / (m K) or more, The adhesive paste has an adhesive strength of 5 N / mm□ or more between the cured product obtained by heating and curing the adhesive paste at 170°C for 2 hours and a silver-plated copper plate at 100°C.

3. An adhesive paste containing a curable organopolysiloxane compound (A), a thermally conductive filler (T), and a silane coupling agent (B), the curable organopolysiloxane compound (A) is a polysilsesquioxane compound, the silane coupling agent (B) contains an isocyanurate-based silane coupling agent or a urea-based silane coupling agent (B1) and a silane coupling agent having an acid anhydride structure (B2); The volume filling rate of the thermally conductive filler (T) in the solid content of the adhesive paste is 10 vol% or more and less than 60 vol%, The thermal conductivity of the cured product obtained by heating and curing the adhesive paste at 120°C for 4 hours is 0.5 W / (m K) or more, The adhesive paste has an adhesive strength of 5 N / mm□ or more between the cured product obtained by heating and curing the adhesive paste at 170°C for 2 hours and a silver-plated copper plate at 100°C.

4. An adhesive paste containing a curable organopolysiloxane compound (A), a thermally conductive filler (T), and a silane coupling agent (B), the curable organopolysiloxane compound (A) is a polysilsesquioxane compound, the silane coupling agent (B) contains an isocyanurate-based silane coupling agent or a urea-based silane coupling agent (B1) and a silane coupling agent having an acid anhydride structure (B2); The solid content concentration is 90% by mass or more and 99% by mass or less, The thermal conductivity of the cured product obtained by heating and curing the adhesive paste at 120°C for 4 hours is 0.5 W / (m K) or more, The adhesive paste has an adhesive strength of 5 N / mm□ or more between the cured product obtained by heating and curing the adhesive paste at 170°C for 2 hours and a silver-plated copper plate at 100°C.

5. The adhesive paste according to any one of claims 1 to 4, wherein the thermally conductive filler (T) is an inorganic filler having a thermal conductivity of 5 W / (m K) or more.

6. 6. The adhesive paste according to claim 1, wherein the thermally conductive filler (T) is at least one selected from the group consisting of titanium oxide, alumina, and aluminum nitride.

7. 7. An adhesive paste according to claim 1, wherein the thermally conductive filler (T) is titanium oxide.

8. 8. The adhesive paste according to claim 1, wherein the volume filling rate of the thermally conductive filler (T) in the solid content of the adhesive paste is 10 vol% or more and less than 60 vol%.

9. The adhesive paste according to any one of claims 2 to 8, wherein the silane coupling agent (B) is contained in an amount of 1.5 parts by mass or more and less than 20 parts by mass per 100 parts by mass of the solid content of the adhesive paste.

10. 10. The adhesive paste according to claim 1, which is substantially free of a noble metal catalyst.

11. 11. The adhesive paste according to claim 1, wherein the solid content concentration is 90% by mass or more and 99% by mass or less.

12. The adhesive paste according to any one of claims 1 to 11, which is an adhesive for a semiconductor element fixing material.

13. A method of using the adhesive paste according to any one of claims 1 to 12 as an adhesive for a semiconductor element fixing material.

14. A method for manufacturing a semiconductor device using the adhesive paste according to any one of claims 1 to 12 as an adhesive for a semiconductor element fixing material, the method comprising the following steps (BI) and (BII): Step (BI): A step of applying the adhesive paste to the adhesive surface of one or both of the semiconductor element and the supporting substrate and pressing them together. Step (BII): A step of heating and hardening the adhesive paste of the pressure-bonded product obtained in step (BI) to fix the semiconductor element to the support substrate.

Images