Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
  • C09J11/02—Non-macromolecular additives
  • C09J11/04—Non-macromolecular additives inorganic
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J183/00—Adhesives based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Adhesives based on derivatives of such polymers
  • C09J183/04—Polysiloxanes
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W72/00—Interconnections or connectors in packages
  • H10W72/071—Connecting or disconnecting

Definitions

• the present invention provides an adhesive paste having a high thermal conductivity in a cured product obtained by heating and having excellent adhesiveness in a cured product obtained by heating at a high temperature, and this adhesive paste as an adhesive for a semiconductor element fixing material. and a method of manufacturing a semiconductor device using this adhesive paste as an adhesive for a semiconductor element fixing material.
• Adhesive pastes have been improved in various ways according to their uses, and have been widely used industrially as raw materials for optical parts and moldings, adhesives, coating agents, and the like. Adhesive pastes are also attracting attention as pastes for semiconductor element fixing materials such as adhesives for semiconductor element fixing materials.
• Semiconductor elements include light-emitting elements such as lasers and light-emitting diodes (LEDs), optical semiconductor elements such as light-receiving elements such as solar cells, transistors, sensors such as temperature sensors and pressure sensors, and integrated circuits.
• LEDs light-emitting elements
• LEDs light-emitting diodes
• optical semiconductor elements such as light-receiving elements such as solar cells
• transistors transistors
• sensors such as temperature sensors and pressure sensors, and integrated circuits.
• the cured adhesive paste used for fixing the elements has been exposed to higher energy light and higher temperature heat generated from the semiconductor elements for a longer period of time.
• problems such as a decrease in adhesive force, detachment due to deterioration, and deterioration in the performance of the semiconductor element. Therefore, it is important to improve the thermal conductivity of the cured adhesive paste, efficiently exhaust the heat generated from the semiconductor element, and maintain or improve the performance of the semiconductor element at a high level.
• a method of manufacturing a semiconductor device having a semiconductor element for example, there is a method including a step of fixing a 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.
• an adherend such as a lead frame with an adhesive sheet
• a step of curing the adhesive sheet for example, there is a method including a step of curing the adhesive sheet, and a wire bonding step.
• Patent Document 1 describes a curable composition whose cured product has excellent adhesiveness.
• the curable composition described in Patent Document 1 does not focus on the thermal conductivity of the cured product obtained by heating and curing the curable composition, and the evaluation results regarding the thermal deterioration of the semiconductor element are described. It has not been.
• the present invention has been made in view of such circumstances, and is capable of reducing or preventing thermal deterioration of optical components, sensor chips, etc. due to heat generation of a semiconductor element or a semiconductor device equipped with the semiconductor element.
• An object of the present invention is to provide a method of manufacturing a semiconductor device.
• "high temperature” means "150°C to 190°C”.
• excellent adhesiveness means "high adhesive strength”.
• a cured product with high thermal conductivity obtained by heating and curing an adhesive paste containing a curable organopolysiloxane compound is used as an optical component or a sensor chip associated with heat generation of a semiconductor element or a semiconductor device equipped with the semiconductor element. It is possible to reduce or prevent thermal deterioration such as (ii) 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 a semiconductor element in a wire bonding process. , and completed the present invention.
• the following adhesive pastes [1] to [6], a method of using the adhesive paste of [7], and a method of manufacturing a semiconductor device using the adhesive paste of [8] are provided.
• Conductivity is 0.5 W / (m K) or more, and the adhesive strength at 100 ° C. between the cured product obtained by heating and curing the adhesive paste at 170 ° C. for 2 hours and the silver-plated copper plate is 5 N /
• a method of using the adhesive paste according to any one of [1] to [6] as an adhesive for a semiconductor element fixing material comprising the steps (BI) and (BII) below.
• Adhesive pastes are provided that can be reduced or prevented. Further, according to the present invention, there are provided a method of using this adhesive paste as an adhesive for a semiconductor element fixing material, and a method of manufacturing a semiconductor device using this adhesive paste as an adhesive for a semiconductor element fixing material.
• the present invention will be described in detail below by dividing it into 1) adhesive paste, 2) method of using the adhesive paste, and method of manufacturing a semiconductor device using the adhesive paste.
• Adhesive paste is an adhesive paste containing a curable organopolysiloxane compound (A) and a thermally conductive filler (T), and is cured by heating at 120°C for 4 hours.
• the thermal conductivity of the cured product obtained is 0.5 W / (m K) or more, and the cured product obtained by heating and curing the adhesive paste at 170 ° C. for 2 hours and the silver-plated copper plate are 100
• the adhesive strength at °C is 5 N/mm square or more.
• the "adhesive paste” means "a viscous liquid at room temperature (23°C) and in a fluid state”. Since the adhesive paste of the present invention has the properties described above, it is excellent in workability in the coating process.
• excellent workability in the coating process means “in the coating 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 is interrupted immediately, and the resin It must not contaminate the surroundings by splashing or spread of droplets after application.”
• the adhesive paste of the present invention has a thermal conductivity of 0.5 W/(m ⁇ K) or more, preferably 0.7 W/(m ⁇ K), which is obtained by heating and curing the adhesive paste at 120° C. for 4 hours. Above, more preferably 1.0 W/(m ⁇ K) or more, still more preferably 1.5 W/(m ⁇ K) or more, and particularly preferably 2.0 W/(m ⁇ K) or more.
• a cured product having a thermal conductivity equal to or higher than the lower limit value obtained by heat curing can reduce or prevent thermal deterioration of optical components, sensor chips, etc. due to heat generation of a semiconductor element or a semiconductor device equipped with the semiconductor element. becomes possible.
• the thermal conductivity of the cured product obtained by heating and 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 heating at 120° C. for 4 hours to prepare a test piece. After that, the thermal diffusivity of this test piece is measured by the temperature wave method using a thermal diffusivity measuring device.
• the components excluding the thermally conductive filler (T) have a specific heat of 1 J/(g K) and a density of 1.2 g/cm 3 . Assuming, the thermal conductivity is calculated by the following formula.
• Thermal conductivity [W/(m ⁇ K)] Thermal diffusivity (m 2 /s) x Specific heat [J/(g ⁇ K)] x Density (g/cm 3 ) x 10 6 More specifically, it can be measured by the method described in Examples.
• the adhesive paste of the present invention has an adhesive strength of 5 N/mm square or more, preferably 10 N/mm square or more at 100° C. between a cured product obtained by heating and curing the adhesive paste at 170° C. for 2 hours and a silver-plated copper plate. More preferably, it is 13 N/mm square or more.
• the adhesive strength is equal to or higher than the above lower limit, the cured product obtained by heating and curing at a high temperature can reduce or prevent peeling of the semiconductor element in the wire bonding process.
• the adhesive strength of the cured product obtained by heating and curing the adhesive paste of the present invention can be measured, for example, as follows.
• the adhesive paste of the present invention is applied to the mirror surface of a square silicon chip with a side length of 1 mm (area is 1 mm 2 ), and the coated surface is placed on a silver-plated copper plate and crimped (adhesive paste after crimping). thickness: about 3 ⁇ m) and 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 in the horizontal direction (shear direction) to the adhesive surface at a speed of 200 ⁇ m / s from a position 100 ⁇ m above the adherend, The adhesive strength (N/mm ⁇ ) between the test piece and the adherend is measured.
• “1 mm square” means “1 mm square", that is, “1 mm x 1 mm (square with a side length of 1 mm)". More specifically, it can be measured by the method described in Examples.
• the adhesive paste of the present invention contains a curable organopolysiloxane compound (A) (hereinafter sometimes referred to as "component (A)"). Since the adhesive paste of the present invention contains the component (A), a cured product having excellent adhesiveness can be easily obtained by heating at a high temperature.
• 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 its molecule.
• component (A) is a thermosetting compound, at least one functional group selected from the group consisting of functional groups capable of condensation reaction by heating and functional groups capable of condensation reaction through hydrolysis It is preferred to have a group.
• a functional group is preferably at least one selected from the group consisting of a hydroxyl group and an alkoxy group, more preferably a hydroxyl group and an alkoxy group having 1 to 10 carbon atoms.
• the main chain structure of the curable organopolysiloxane compound (A) is not particularly limited, and may be linear, ladder-like, or cage-like.
• the structure represented by the following formula (a-1) is used as the linear main chain structure
• the structure represented by the following formula (a-2) is used as the ladder-like main chain structure.
• Examples of the main chain structure include structures represented by the following formula (a-3).
• Rx, Ry, and Rz each independently represent a hydrogen atom or an organic group, and the organic group includes an unsubstituted or substituted alkyl group, an unsubstituted A substituted or substituted cycloalkyl group, an unsubstituted or substituted alkenyl group, an unsubstituted or substituted aryl group, or an alkylsilyl group is preferred.
• the plurality of Rx in formula (a-1), the plurality of Ry in formula (a-2), and the plurality of Rz in formula (a-3) may be the same or different. However, both Rx in formula (a-1) are not hydrogen atoms.
• alkyl group of the unsubstituted or substituted alkyl group examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, C1-C10 alkyl groups such as n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, n-heptyl group and n-octyl group can be mentioned.
• cycloalkyl groups of unsubstituted or substituted cycloalkyl groups include cycloalkyl groups having 3 to 10 carbon atoms such as cyclobutyl group, cyclopentyl group, cyclohexyl group and cycloheptyl group.
• Alkenyl groups of unsubstituted or substituted alkenyl groups include, for example, vinyl group, 1-propenyl group, 2-propenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, and the like. Ten alkenyl groups are mentioned.
• substituents of 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; unsubstituted or substituted aryl groups such as phenyl group, 4-methylphenyl group and 4-chlorophenyl group; and the like.
• aryl groups of unsubstituted or substituted aryl groups include aryl groups having 6 to 10 carbon atoms such as phenyl group, 1-naphthyl group and 2-naphthyl group.
• the substituents of the aryl group include halogen atoms such as fluorine, chlorine, bromine and iodine atoms; alkyl groups having 1 to 6 carbon atoms such as methyl and ethyl groups; 1 to 6 alkoxy groups; nitro group; cyano group; hydroxyl group; thiol group; epoxy group; glycidoxy group; (meth) acryloyloxy group; an aryl group having a substituent; and the like.
• alkylsilyl groups include trimethylsilyl group, triethylsilyl group, triisopropylsilyl group, tri-t-butylsilyl group, methyldiethylsilyl group, dimethylsilyl group, diethylsilyl group, methylsilyl group and ethylsilyl group.
• Rx, Ry, and Rz are preferably a hydrogen atom, an unsubstituted or substituted C 1-6 alkyl group, or a phenyl group, and an unsubstituted or substituted C 1-6 Alkyl groups are particularly preferred.
• the curable organopolysiloxane compound (A) can be obtained, for example, by a known production method of polycondensing a silane compound having a hydrolyzable functional group (alkoxy group, halogen atom, etc.).
• the silane compound to be used may be appropriately selected according to the desired structure of the thermosetting organopolysiloxane compound (A).
• Preferred specific examples include bifunctional silane compounds such as dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, and diethyldiethoxysilane; methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-butyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyldiethoxymethoxysilane, etc.
• the mass average molecular weight (Mw) of the curable organopolysiloxane compound (A) is usually 800 or more and 30,000 or less, preferably 1,000 or more and 20,000 or less, more preferably 1,200 or more and 15,000 or less, Especially preferably, it is 3,000 or more and 10,000 or less.
• the molecular weight distribution (Mw/Mn) of the curable organopolysiloxane compound (A) is not particularly limited, it is usually 1.0 or more and 10.0 or less, preferably 1.1 or more and 6.0 or less.
• Mw/Mn molecular weight distribution
• the mass average molecular weight (Mw) and number average molecular weight (Mn) can be obtained as standard polystyrene conversion values by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, for example.
• the curable organopolysiloxane compound (A) of the present invention is preferably a polysilsesquioxane compound obtained by polycondensation of a trifunctional organosilane compound. Since the adhesive paste of the present invention contains a polysilsesquioxane compound as the component (A), it becomes easier to obtain a cured product having excellent adhesiveness by heating at a high temperature. Therefore, the chip can be held more efficiently in the wire bonding process.
• 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 the component (A), a polysilsesquioxane compound having a repeating unit represented by the following formula (a-4), whereby a cured product that is excellent in adhesiveness when heated at a high temperature becomes easier to obtain.
• (R 1 -D) represents an organic group.
• R 1 is preferably an unsubstituted alkyl group or an alkyl group having a substituent, and is an unsubstituted alkyl group having 1 to 10 carbon atoms or a substituent. is more preferred.
• D represents a linking group (excluding an alkylene group) connecting R 1 and Si or a single bond.
• the "unsubstituted alkyl group having 1 to 10 carbon atoms” includes methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n- pentyl group, n-hexyl group, n-octyl group, n-nonyl group, n-decyl group and the like.
• the number of carbon atoms in the “unsubstituted alkyl group having 1 to 10 carbon atoms” represented by R 1 is preferably 1 to 6, more preferably 1 to 3.
• the number of carbon atoms in the “substituted alkyl group having 1 to 10 carbon atoms” represented by R 1 is preferably 1 to 6, more preferably 1 to 3.
• the number of carbon atoms means the number of carbon atoms in the portion (alkyl group portion) excluding the substituents. Therefore, when R 1 is a “substituted alkyl group having 1 to 10 carbon atoms”, the number of carbon atoms in R 1 may exceed 10 in some cases.
• Examples of the alkyl group of the "substituted alkyl group having 1 to 10 carbon atoms" include the same groups as the "unsubstituted alkyl group having 1 to 10 carbon atoms".
• substituents of the "substituted alkyl group having 1 to 10 carbon atoms” include halogen atoms such as a fluorine atom, a chlorine atom and a bromine atom; a cyano group; a group represented by the formula: OJ;
• the number of substituent atoms in the "substituted alkyl group having 1 to 10 carbon atoms" (excluding the number of hydrogen atoms) is generally 1 to 30, preferably 1 to 20.
• J represents a hydroxyl-protecting group.
• the hydroxyl-protecting group is not particularly limited, and includes known protecting groups known as hydroxyl-protecting groups.
• acyl group silyl group such as trimethylsilyl group, triethylsilyl group, t-butyldimethylsilyl group, t-butyldiphenylsilyl group; methoxymethyl group, methoxyethoxymethyl group, 1-ethoxyethyl group, tetrahydropyran-2- acetal group such as yl group and tetrahydrofuran-2-yl group; alkoxycarbonyl group such as t-butoxycarbonyl group; methyl group, ethyl group, t-butyl group, octyl group, allyl group, triphenylmethyl group, benzyl group, ethers such as p-methoxybenzyl group, fluorenyl group, trityl group and benzhydryl group;
• R 1 is an unsubstituted alkyl group having 1 to 10 carbon atoms, or fluorine, from the viewpoint of easily obtaining a polysilsesquioxane compound with a stable structure and more stable performance as an adhesive paste.
• An alkyl group having 1 to 10 carbon atoms and having a fluorine atom is preferable, and an alkyl group having 1 to 10 carbon atoms and having a fluorine atom is more preferable.
• the alkyl group having 1 to 10 carbon atoms and having a fluorine atom includes a group represented by the composition formula: C m H (2m ⁇ n+1) F n (m is an integer of 1 to 10, n is 2 or more, (2m+1) are the following integers). Note that m is preferably an integer of 1 to 5, more preferably an integer of 1 to 3.
• the fluoroalkyl group represented by the compositional formula: C m H (2m ⁇ n+1) F n includes CF 3 , CF 3 CF 2 , CF 3 (CF 2 ) 2 , CF 3 (CF 2 ) 3 , CF 3 ( perfluoroalkyl groups such as CF2 ) 4 , CF3 ( CF2) 5 , CF3 ( CF2) 6 , CF3 ( CF2) 7 , CF3 ( CF2) 8 , CF3 ( CF2) 9 ; hydrofluoroalkyl groups such as CF3CH2CH2 , CF3 ( CF2 ) 3CH2CH2 , CF3 ( CF2 ) 5CH2CH2 , CF3 ( CF2 ) 7CH2CH2 ; is mentioned. Among these, a CF 3 CH 2 CH 2 group is preferred.
• D represents a linking group connecting R 1 and Si (excluding an alkylene group) or a single bond, preferably a single bond.
• Examples of the linking group for D include arylene groups having 6 to 20 carbon atoms such as 1,4-phenylene group, 1,3-phenylene group, 1,2-phenylene group and 1,5-naphthylene group.
• the polysilsesquioxane compound may be one having one (R 1 -D) (homopolymer) or two or more (R 1 -D) (copolymer).
• the polysilsesquioxane compound when the polysilsesquioxane compound is a copolymer, the polysilsesquioxane compound may be any of random copolymers, block copolymers, graft copolymers, alternating copolymers, and the like. , random copolymers are preferred from the viewpoint of ease of production.
• the structure of the polysilsesquioxane compound may be any one of a ladder structure, a double decker structure, a cage structure, a partially cleaved cage structure, a cyclic structure, and a random structure.
• the content of the repeating unit represented by the formula (a-4) (that is, the T site described later) in the polysilsesquioxane compound is usually 50 to 100 mol% of the total repeating units, and 70 It is more preferably up to 100 mol %, still more preferably 90 to 100 mol %, and particularly preferably 100 mol %.
• 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). That is, (R 1 -D) in formula (a-4) above may be R 2 in formula (a-5) below.
• R 2 is an unsubstituted cycloalkyl group, a substituted cycloalkyl group, an unsubstituted alkenyl group, a substituted alkenyl group, an unsubstituted aryl group, or a substituted represents a group selected from the group consisting of an aryl group and an alkylsilyl group; Among these, unsubstituted aryl groups having 6 to 12 carbon atoms and substituted aryl groups having 6 to 12 carbon atoms are preferable.
• Examples of the “unsubstituted aryl group having 6 to 12 carbon atoms” include phenyl group, 1-naphthyl group, 2-naphthyl group and the like.
• the number of carbon atoms in the “unsubstituted aryl group having 6 to 12 carbon atoms” represented by R 2 is preferably 6.
• the number of carbon atoms in the “substituted aryl group having 6 to 12 carbon atoms” represented by R 2 is preferably 6.
• the number of carbon atoms means the number of carbon atoms in the portion (aryl group portion) excluding the substituents. Therefore, when R 2 is a “substituted aryl group having 6 to 12 carbon atoms”, the number of carbon atoms of R 2 may exceed 12 in some cases.
• Examples of the aryl group of the "substituted aryl group having 6 to 12 carbon atoms” include the same aryl groups as the "unsubstituted aryl group having 6 to 12 carbon atoms".
• substituents of the "substituted aryl group having 6 to 12 carbon atoms” include halogen atoms such as a fluorine atom, a chlorine atom and a bromine atom; alkoxy groups such as a methoxy group and an ethoxy group;
• the number of substituent atoms (excluding the number of hydrogen atoms) of the "substituted C6-C12 aryl group" is usually 1-30, preferably 1-20.
• the polysilsesquioxane compound may have one type of R2 , or two or more types of R2. may have an R 2 of
• the content ratio of the repeating unit (T site) represented by the formula (a-4) in the polysilsesquioxane compound is, for example, 29 Si- when NMR peak assignment and area integration are possible. It can be determined by measuring NMR and 1 H-NMR.
• Polysilsesquioxane compounds include ketone solvents such as acetone; aromatic hydrocarbon solvents such as benzene; sulfur-containing solvents such as dimethylsulfoxide; ether solvents such as tetrahydrofuran; ester solvents such as ethyl acetate; soluble in various organic solvents such as halogen-containing solvents such as; and mixed solvents comprising two or more of these. Therefore, these solvents can be used to measure the 29 Si-NMR of the polysilsesquioxane compound in a solution state.
• the repeating unit represented by the formula (a-4) is preferably represented by the following formula (a-6).
• G represents (R 1 -D), and R 1 and D have the same meanings as R 1 and D in formula (a-4) above.
• * 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.
• alkyl groups having 1 to 10 carbon atoms represented by * include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group and t-butyl group.
• a plurality of * may all be the same or different.
• the polysilsesquioxane compound has three oxygen atoms bonded to a silicon atom, generally referred to as T site, and other groups (group represented by G ) are combined to form a partial structure.
• the polysilsesquioxane compound is a thermosetting compound, and is a compound capable of undergoing condensation reaction and/or hydrolysis by heating. Therefore, at least one of * in the above formula (a-6) of the plurality of repeating units (T sites) possessed by the polysilsesquioxane compound is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. is preferred, and a hydrogen atom is more preferred.
• the hydrogen atom or the number of carbon atoms in * in the above formula (a-6) is 1 to 1 It is possible to confirm the presence of 10 alkyl groups and whether or not the three * in the above formula (a-6) are all repeating units of Si atoms. Furthermore, when assignment of 29 Si-NMR peaks and integration of areas are possible, with respect to the total number of repeating units (T sites) represented by the formula (a-4) in the polysilsesquioxane compound, The total number of repeating units in which all three * in the formula (a-6) are Si atoms can be roughly estimated.
• the total number of repeating units in which are all Si atoms is preferably 30 to 95 mol%, more preferably 40 to 90 mol%, from the viewpoint of easily obtaining an adhesive paste that gives a cured product having excellent heat resistance. .
• polysilsesquioxane compounds can be used singly or in combination of two or more.
• the method for producing the polysilsesquioxane compound is not particularly limited.
• the following formula (a-7) is not particularly limited.
• the following formula (a-7) is not particularly limited.
• the following formula (a-7) is not particularly limited.
• R 1 and D have the same meaning as R 1 and D in formula (a-4) above;
• R 3 represents an alkyl group having 1 to 10 carbon atoms;
• X 1 represents a halogen atom;
• p represents an integer of 0 to 3. Multiple R 3 and multiple X 1 may be the same or different.
• a polysilsesquioxane compound can be produced by polycondensing at least one of the silane compounds (1) represented by.
• Examples of the alkyl group having 1 to 10 carbon atoms for R 3 include the same groups as the alkyl group having 1 to 10 carbon atoms represented by * in the above formula (a-6).
• a chlorine atom, a bromine atom, etc. are mentioned as a halogen atom of X1.
• silane compound (1) examples include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, Alkyltrialkoxy such as n-propyltripropoxysilane, n-propyltributoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, isooctyltriethoxysilane, etc. silane compounds;
• methyltrichlorosilane methyltribromosilane, ethyltrichlorosilane, ethyltribromosilane, n-propyltrichlorosilane, n-propyltribromosilane, n-butyltrichlorosilane, isobutyltrichlorosilane, n-pentyltrichlorosilane, n-hexyl Alkyltrihalogenosilane compounds such as trichlorosilane and isooctyltrichlorosilane;
• Phenyltrialkoxysilane compounds such as phenyltrimethoxysilane, phenyltriethoxysilane, phenyldiethoxymethoxysilane, 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.
• the method of polycondensing the silane compound (1) is not particularly limited.
• a method of adding a predetermined amount of a polycondensation catalyst to the silane compound (1) in a solvent or without a solvent and stirring the mixture at a predetermined temperature can be used. More specifically, (a) a method of adding a predetermined amount of an acid catalyst to the silane compound (1) and stirring at a predetermined temperature; (b) adding a predetermined amount of a base catalyst to the silane compound (1); (c) adding a predetermined amount of an acid catalyst to the silane compound (1) and stirring at a predetermined temperature; and then adding an excess amount of a base catalyst to make the reaction system basic. , a method of stirring at a predetermined temperature, and the like. Among these, the method (a) or (c) is preferable because the desired polysilsesquioxane compound can be obtained efficiently.
• the polycondensation catalyst to be used may be either an acid catalyst or a base catalyst. Two or more polycondensation catalysts may be used in combination, but at least an acid catalyst is preferably used.
• Acid catalysts include inorganic acids such as phosphoric acid, hydrochloric acid, boric acid, sulfuric acid and nitric acid; organic acids such as citric acid, acetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid and p-toluenesulfonic acid; is mentioned. Among these, at least one selected from phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, citric acid, acetic acid, and methanesulfonic acid is preferred.
• Base catalysts include aqueous ammonia; trimethylamine, triethylamine, lithium diisopropylamide, lithium bis(trimethylsilyl)amide, pyridine, 1,8-diazabicyclo[5.4.0]-7-undecene, aniline, picoline, 1,4- Organic bases such as diazabicyclo[2.2.2]octane and imidazole; Organic salt hydroxides such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; sodium methoxide, sodium ethoxide, sodium t-butoxide, potassium t-butoxide Metal alkoxides such as; 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; metal hydrogen carbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate;
• the amount of the polycondensation catalyst used is usually in the range of 0.05 to 10 mol%, preferably 0.1 to 5 mol%, relative to the total mol amount of the silane compound (1).
• the solvent to be used can be appropriately selected according to the type of silane compound (1).
• the solvent to be used can be appropriately selected according to the type of silane compound (1).
• 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.
• 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 singly or in combination of two or more. Further, when the above method (c) is employed, after the polycondensation reaction is carried out in an aqueous system in the presence of an acid catalyst, an organic solvent and an excess amount of a base catalyst (such as aqueous ammonia) are added to the reaction solution, A further polycondensation reaction may be carried out under basic conditions.
• a base catalyst such as aqueous ammonia
• the amount of the solvent used is usually 0.001 liters or more and 10 liters or less, preferably 0.01 liters or more and 0.9 liters or less per 1 mol of the total molar amount of the silane compound (1).
• the temperature at which the silane compound (1) is polycondensed is usually in the temperature range from 0°C to the boiling point of the solvent used, preferably in the range of 20°C or higher and 100°C or lower. If the reaction temperature is too low, the polycondensation reaction may proceed insufficiently. On the other hand, if the reaction temperature is too high, it becomes difficult to suppress gelation. The reaction is usually completed in 30 minutes to 30 hours.
• a monomer in which R 1 is an alkyl group having a fluorine atom tends to be less reactive than a monomer in which R 1 is a normal alkyl group.
• a polysilsesquioxane compound having a desired molecular weight can be easily obtained by reducing the amount of catalyst and conducting the reaction under mild conditions for a long time.
• an aqueous alkali solution such as sodium hydrogen carbonate is added to the reaction solution
• an acid such as hydrochloric acid is added to the reaction solution.
• the resulting salt is removed by filtration or washing with water to obtain the intended polysilsesquioxane compound.
• the portion of OR 3 or X 1 of the silane compound (1) that did not undergo hydrolysis and subsequent condensation reaction is the polysilsesquioxane compound remain inside.
• the adhesive paste of the present invention is different from general heat-curable silicone adhesives that are cured by an addition reaction in the presence of a noble metal catalyst such as a platinum catalyst. Accordingly, the adhesive paste containing the polysilsesquioxane compound of the present invention contains substantially no noble metal catalyst or contains only a small amount of noble metal catalyst.
• substantially contains no noble metal catalyst or has a low noble metal catalyst content means that "a component that can be interpreted as a noble metal catalyst is not intentionally added, and an effective It means that the content of the noble metal catalyst is, for example, less than 1 ppm by mass in terms of the mass of the catalytic metal element with respect to the amount of the components.
• the "active ingredient” refers to "the ingredient excluding the solvent (S) contained in the adhesive paste”.
• the adhesive paste does not substantially contain a noble metal catalyst, or contains a noble metal catalyst, from the viewpoint of stable production in consideration of formulation variations, etc., storage stability, and the viewpoint that noble metal catalysts are expensive. is preferably less.
• the thermally conductive filler (T) (hereinafter sometimes referred to as "(T) component") 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), particularly preferably is 10 W/(m ⁇ K) or more and less than 100 W/(m ⁇ K).
• 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 measuring device (for example, LFA477 Nanoflash manufactured by NETZSCH-Geratebau GmbH).
• the component of the thermally conductive filler (T) is not particularly limited as long as it improves thermal conductivity, and examples thereof include metals; metal oxides; carbides; and nitrides.
• Metals are 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 C and Si) in the periodic table.
• 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.
• Carbides include magnesium carbonate, silicon carbide, and calcium carbonate
• nitrides include boron nitride, aluminum nitride, and the like.
• the thermally conductive filler (T) can be used singly or in combination of two or more. Among these, in the present invention, it is easy to mix well with the component (A), and the cured product obtained by heat curing has a high thermal conductivity, so that an adhesive paste with excellent adhesiveness can be easily obtained. Titanium oxide, alumina and aluminum nitride are preferred, and alumina is more preferred.
• the shape of the thermally conductive filler (T) may be spherical, chain-like, needle-like, plate-like, plate-like, flake-like, rod-like, fiber-like, etc., but is preferably spherical.
• spherical means “generally spherical, as well as nearly spherical, including polyhedral shapes that can be approximated to spheres such as spheroids, ovoids, confetti-like, and cocoon-like".
• the average particle size of the thermally conductive filler (T) is preferably 0.1 ⁇ m or more and less than 5 ⁇ m, more preferably 0.2 ⁇ m or more and less than 4 ⁇ m, still more preferably 0.4 ⁇ m or more and less than 3.5 ⁇ m, and particularly preferably 0.8 ⁇ m. It is more than 3 ⁇ m and less than 3 ⁇ m.
• the average particle diameter of the component (T) is within the above range, it is easy to mix well with the component (A) and relatively easy to mix as an adhesive paste, and a cured product obtained by heat curing. It becomes easy to obtain an adhesive paste with high thermal conductivity and excellent adhesiveness.
• the thickness of the coating film of the adhesive paste is usually about 0.5 ⁇ m or more and 10 ⁇ m or less, and from the viewpoint that the semiconductor element can be horizontally mounted on the applied adhesive paste, the average particle size It is preferably less than the upper limit.
• the thermally conductive filler (T) is not in contact with each other, but the (T) component and the (A) component should be in contact as much as possible. That is, it is preferable that the entire surface of each thermally conductive filler (T) is coated with the component (A) as much as possible.
• the average particle size of the thermally conductive filler (T) can be calculated, for example, by primary particle size measurement by transmission electron microscope observation/image analysis and X-ray transmission sedimentation method using a particle size distribution analyzer (Sedigraph). can.
• 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%, and particularly preferably 30 vol% or more and less than 60 vol%.
• the volume filling factor 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 the solid content of the adhesive paste is calculated from the mass and density of the components excluding the (T) component among the solid content of the adhesive paste.
• volume filling rate (vol%) [volume of (T) component (cm 3 )/[volume of (T) component (cm 3 ) + volume of component excluding (T) component among solids of adhesive paste (cm 3 )]] ⁇ 100 More specifically, it can be measured and calculated by the method described in Examples.
• the content of component (T) 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 85 parts by mass, relative to 100 parts by mass of the solid content of the adhesive paste. less than, more preferably 40 parts by mass or more and less than 80 parts by mass.
• the content of component (T) is not particularly limited, but the amount is preferably 40 parts by mass or more and less than 1000 parts by mass, more preferably 60 parts by mass, relative to 100 parts by mass of the solid content of component (A). 900 parts by mass or more, more preferably 80 parts by mass or more and less than 800 parts by mass, particularly preferably 100 parts by mass or more and less than 600 parts by mass.
• the adhesive paste of the present invention contains a curable organopolysiloxane compound (A) and a thermally conductive filler (T), and may contain the following components.
• 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)”).
• organic solvent (SH) organic solvent having a boiling point of 254° C. or higher
• boiling point refers to "boiling point at 1013 hPa” (same in this specification).
• the boiling point of the organic solvent (SH) is preferably 254° C. or higher, more preferably 254° C. or higher and 300° C. or lower.
• organic solvent examples 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 264-294° C.), tetraethylene glycol dimethyl ether (boiling point 275° C.), polyethylene glycol monomethyl ether (boiling point 290-310° C.) and the like.
• organic solvent (SH) tripropylene glycol-n-butyl ether and 1,6-hexanediol diacrylate are preferable as the organic solvent (SH) from the viewpoint that the effects of the present invention can be more easily obtained.
• the organic solvent (SH) may be used singly or in combination of two or more.
• the adhesive paste of the present invention may contain a solvent other than the organic solvent (SH).
• a solvent other than the organic solvent (SH) a solvent having a boiling point of 100° C. or more and less than 254° C. (hereinafter sometimes referred to as “organic solvent (SL)”) is preferable.
• the organic solvent (SL) is not particularly limited as long as it has a boiling point of 100° C. or more and less than 254° C. and can dissolve or disperse the components of the adhesive paste of the present invention.
• the temperature range for heating the adhesive paste to obtain a cured product can be adjusted more precisely. It is possible to reduce the influence of heating on parts and sensor chips.
• organic solvent examples 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.), and diethylene glycol butyl methyl ether.
• the organic solvent (SL) is preferably a glycol-based solvent, preferably diethylene glycol monobutyl ether acetate or dipropylene glycol-n-butyl ether, more preferably diethylene glycol monobutyl ether acetate, from the viewpoint of easily mixing the active ingredient. preferable.
• 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)), 1, A combination of 6-hexanediol diacrylate (solvent (SH)) and diethylene glycol monobutyl ether acetate (solvent (SL)), tripropylene glycol-n-butyl ether (solvent (SH)) and dipropylene glycol-n-butyl ether (solvent (SL)), a combination of 1,6-hexanediol diacrylate (solvent (SH)) and dipropylene glycol-n-butyl ether (solvent (SL)) is preferred.
• the adhesive paste of the present invention preferably contains the solvent (S) in such an amount 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.
• the solid content concentration is within this range, it is easy to mix the active ingredient well, and the workability in the process of filling the syringe with the adhesive paste and the coating process is excellent.
• excellent workability in the step of filling the syringe with the adhesive paste means “capable of filling an appropriate amount into the syringe without air bubbles".
• the adhesive paste of the present invention may contain a silane coupling agent as the component (B).
• the silane coupling agent includes a silane coupling agent (B1) having a nitrogen atom in the molecule (hereinafter sometimes referred to as “silane coupling agent (B1)”) and a silane having an acid anhydride structure in the molecule.
• Coupling agent (B2) (hereinafter sometimes referred to as “silane coupling agent (B2)").
• the adhesive paste containing the silane coupling agent (B1) is excellent in workability in the coating process, and is excellent in curability due to condensation reaction with the component (A) when heated, and is adhesive when heated at high temperature. , to give a cured product that is more excellent in heat resistance and crack suppression properties of the cured product.
• excellent crack suppression of the cured product means that "when the adhesive paste is heated to obtain a cured product, cracking does not occur in the cured product due to temperature changes".
• the silane coupling agent (B1) is not particularly limited as long as it is a silane coupling agent having a nitrogen atom in its molecule.
• Examples thereof include trialkoxysilane compounds represented by the following formula (b-1), and dialkoxyalkylsilane compounds and dialkoxyarylsilane compounds represented by the following formula (b-2).
• R a represents an alkoxy group having 1 to 6 carbon atoms such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy and t-butoxy.
• a plurality of R a may be the same or different.
• R b is an alkyl group having 1 to 6 carbon atoms such as a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group; or a phenyl group, 4-chlorophenyl group, 4- An aryl group with or without a substituent such as a methylphenyl group and a 1-naphthyl group;
• R c represents an organic group having 1 to 10 carbon atoms and having a nitrogen atom.
• R c may be further bonded to another silicon atom-containing group.
• Specific examples of the organic group having 1 to 10 carbon atoms for R c include N-2-(aminoethyl)-3-aminopropyl group, 3-aminopropyl group, N-(1,3-dimethyl-butylidene)amino propyl group, 3-ureidopropyl group, N-phenyl-aminopropyl group and the like.
• the compound in which R c is an organic group bonded to another silicon atom-containing group includes an isocyanurate skeleton.
• examples include those that form an isocyanurate-based silane coupling agent by bonding with other silicon atoms, and those that form a urea-based silane coupling agent by bonding with other silicon atoms via a urea skeleton.
• the silane coupling agent (B1) is preferably an isocyanurate-based silane coupling agent and a urea-based silane coupling agent, since a cured product having higher adhesive strength can be easily obtained.
• those having 4 or more silicon-bonded alkoxy groups are preferred. Having 4 or more silicon-bonded alkoxy groups means that the total number of alkoxy groups bonded to the same silicon atom and alkoxy groups bonded to different silicon atoms is 4 or more.
• a compound represented by the following formula (b-3) is a urea-based silane cup having 4 or more silicon-bonded alkoxy groups.
• Ring agents include compounds represented by the following formula (b-4).
• R a has the same meaning as R a in the formulas (b-1) and (b-2).
• Each of t1 to t5 independently represents an integer of 1 to 10, preferably an integer of 1 to 6, and particularly preferably 3.
• Specific examples of the compound represented by formula (b-3) include 1,3,5-N-tris(3-trimethoxysilylpropyl) isocyanurate, 1,3,5-N-tris(3-tri ethoxysilylpropyl) isocyanurate, 1,3,5-N-tris(3-tri-i-propoxysilylpropyl) isocyanurate, 1,3,5-N-tris(3-tributoxysilylpropyl) isocyanurate, etc.
• Specific examples of the compound represented by formula (b-4) include N,N'-bis(3-trimethoxysilylpropyl)urea, N,N'-bis(3-triethoxysilylpropyl)urea, N , N'-bis(3-tripropoxysilylpropyl)urea, N,N'-bis(3-tributoxysilylpropyl)urea, N,N'-bis(2-trimethoxysilylethyl)urea, etc.
• N'-bis[(tri(C1-C6)alkoxysilyl)(C1-C10)alkyl]urea N,N'-bis(3-dimethoxymethylsilylpropyl)urea, N,N'-bis(3-dimethoxyethylsilylpropyl)urea, N,N'-bis(3-diethoxymethylsilylpropyl)urea, etc.
• the silane coupling agents (B1) can be used singly or in combination of two or more.
• the silane coupling agent (B1) includes 1,3,5-N-tris(3-trimethoxysilylpropyl) isocyanurate, 1,3,5-N-tris(3-triethoxysilylpropyl) ) isocyanurate (the above two are hereinafter referred to as “isocyanurate compounds”), N,N′-bis(3-trimethoxysilylpropyl)urea, N,N′-bis(3-triethoxysilylpropyl)urea (The above two are hereinafter referred to as "urea compounds”), and a combination of the isocyanurate compound and the urea compound are preferably used, and the isocyanurate compound is more preferably used.
• the ratio of the two to be used is preferably 100:1 to 100:200 in mass ratio of (isocyanurate compound) to (urea compound), and 100: 10 to 100:110 is more preferred.
• the content of component (B1) is not particularly limited, but the amount is On the other hand, 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, still more preferably 1.3 parts by mass or more and less than 11 parts by mass, particularly preferably 1.5 parts by mass The amount is not less than 9 parts by mass.
• the adhesive paste containing the silane coupling agent (B2) has excellent workability in the coating process, and gives a cured product with excellent adhesiveness and heat resistance when heated at a high temperature.
• Silane coupling agents (B2) include 2-(trimethoxysilyl)ethyl succinic anhydride, 2-(triethoxysilyl)ethyl succinic anhydride, 3-(trimethoxysilyl)propyl succinic anhydride, 3-(tri tri(1-6C)alkoxysilyl(2-8C)alkyl succinic anhydrides, such as ethoxysilyl)propyl succinic anhydride; di(C1-C6)alkoxymethylsilyl(C2-C8)alkyl succinic anhydrides such as 2-(dimethoxymethylsilyl)ethyl succinic anhydride; (1-6 carbon atoms) alkoxydimethylsilyl (2-8 carbon atoms) alkyl succinic anhydrides, such as 2-(methoxydimethylsilyl)ethyl succinic anhydride;
• trihalogenosilyl (2-8 carbon atoms) alkyl succinic anhydrides such as 2-(trichlorosilyl)ethyl succinic anhydride and 2-(tribromosilyl)ethyl succinic anhydride; dihalogenomethylsilyl (2-8 carbon atoms) alkyl succinic anhydride, such as 2-(dichloromethylsilyl)ethyl succinic anhydride; 2-(chlorodimethylsilyl)ethyl succinic anhydride, halogenodimethylsilyl (2-8 carbon atoms) alkyl succinic anhydride; Silane coupling agents (B2) can be used singly or in combination of two or more.
• the silane coupling agent (B2) is preferably tri(C 1-6) alkoxysilyl (C 2-8) alkyl succinic anhydride, 3-(trimethoxysilyl) propyl succinic anhydride or 3-(Triethoxysilyl)propyl succinic anhydride is particularly preferred.
• the content of the (B2) component is not particularly limited, but the amount is On the other hand, 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, still more preferably 0.2 parts by mass or more and less than 2 parts by mass, particularly preferably 0.3 parts by mass It is an amount that is not less than 1.5 parts by mass and less than 1.5 parts by mass.
• the component (B2) in the above range, the effect of adding the component (B2) can be further exhibited, and a cured product having a thermal conductivity of 0.5 W / (m K) or more can be obtained. becomes easier.
• the content of component (B) is not particularly limited, but the amount is preferably 0.00 per 100 parts by mass of the solid content of the adhesive paste. 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, still more preferably 1.3 parts by mass or more and less than 12 parts by mass, particularly preferably 1.5 parts by mass or more and less than 9 parts by mass quantity.
• the component (B) in the above range the effect of adding the component (B) can be further exhibited, and a cured product having a thermal conductivity of 0.5 W / (m K) or more can be obtained. becomes easier.
• the adhesive paste of the present invention contains other components [(C) component] other than the above components (A), (T) and (B) within a range that does not impede the purpose of the present invention.
• Antioxidants are added to prevent oxidative deterioration during heating.
• Antioxidants include phosphorus antioxidants, phenolic antioxidants, sulfur antioxidants, and the like.
• Phosphorus antioxidants include phosphites, oxaphosphaphenanthrene oxides and the like.
• Phenolic antioxidants include monophenols, bisphenols, polymeric phenols, and the like.
• sulfur-based antioxidants include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate.
• antioxidants can be used singly or in combination of two or more.
• the amount of antioxidant to be used is generally 10% by mass or less relative to the component (A).
• a UV absorber is added for the purpose of improving the light resistance of the resulting adhesive paste.
• ultraviolet absorbers include salicylic acids, benzophenones, benzotriazoles, hindered amines and the like. These ultraviolet absorbers can be used singly or in combination of two or more. The amount of the ultraviolet absorber to be used is generally 10% by mass or less relative to the component (A).
• Light stabilizers include, for example, 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 ⁇ ] and other hindered amines. These light stabilizers can be used singly or in combination of two or more.
• the total amount of component (C) used is generally 20% by mass or less relative to component (A).
• the adhesive paste of the present invention can be produced, for example, by a production method comprising the following steps (AI) and (AII).
• step (AI) As a method for obtaining a polysilsesquioxane compound by polycondensing at least one compound represented by the above formula (a-7) in the step (AI) in the presence of a polycondensation catalyst, 1) adhesive paste
• the same methods as those exemplified in the section can be mentioned.
• the solvent (S) and thermally conductive filler (T) used in step (AII) are the same as those exemplified as the solvent (S) and thermally conductive filler (T) in the section of 1) Adhesive paste. mentioned.
• the method of dissolving the polysilsesquioxane compound in the solvent (S) includes, for example, the polysilsesquioxane compound and the thermally conductive filler (T), and optionally the component (B) and (C) are mixed with the solvent (S), defoamed, and dissolved.
• a mixing method and a defoaming 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 steps (AI) and (AII), the adhesive paste of the present invention can be produced efficiently and simply.
• a cured product can be obtained by heating the adhesive paste to volatilize the solvent (S) and cure the adhesive paste.
• the heating temperature for curing is usually 100 to 190°C, preferably 120 to 190°C.
• the heating time for curing is usually 30 minutes to 10 hours, preferably 30 minutes to 5 hours, more preferably 30 minutes to 3 hours.
• the adhesive paste of the present invention has the properties described above, so it can be suitably used as an adhesive for semiconductor element fixing materials.
• semiconductor elements include light-emitting elements such as lasers and light-emitting diodes (LEDs), optical semiconductor elements such as light-receiving elements such as solar cells, transistors, sensors such as temperature sensors and pressure sensors, and integrated circuits.
• LEDs light-emitting elements
• optical semiconductor elements such as light-receiving elements such as solar cells
• transistors transistors
• sensors such as temperature sensors and pressure sensors
• integrated circuits an optical semiconductor element is preferable from the viewpoint that the effect of using the adhesive paste of the present invention is likely to be exhibited more preferably.
• Materials for supporting substrates for bonding semiconductor elements include glasses such as soda lime glass and heat-resistant hard glass; ceramics; sapphire; iron, copper, aluminum, gold, silver, platinum, chromium, titanium and these metals. alloys, metals such as stainless steel (SUS302, SUS304, SUS304L, SUS309, etc.); polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, ethylene-vinyl acetate copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyether Synthetic resins such as ether ketone, polyethersulfone, polyphenylene sulfide, polyetherimide, polyimide, polyamide, acrylic resin, norbornene resin, cycloolefin resin, and glass epoxy resin;
• the adhesive paste of the present invention is preferably filled in a syringe. Since the syringe is filled with the adhesive paste, workability in the coating process is excellent.
• the material of the syringe may be synthetic resin, metal or glass, but synthetic resin is preferred.
• the capacity of the syringe is not particularly limited, and may be appropriately determined according to the amount of adhesive paste to be filled or applied.
• a commercial item can also be used as a syringe. Commercially available products include, for example, SS-01T series (manufactured by TERUMO) and PSY series (manufactured by Musashi Engineering).
• the syringe filled with the adhesive paste descends vertically to approach the support substrate, and after discharging a predetermined amount of the adhesive paste from the tip of the syringe, the syringe rises to support the support substrate. As the substrate is separated, the support substrate moves laterally. By repeating this operation, the adhesive paste is continuously applied to the support substrate. After that, a semiconductor element is mounted on the applied adhesive paste and pressure-bonded to the support substrate.
• the amount of the adhesive paste to be applied is not particularly limited, and may be any amount that allows the semiconductor element to be adhered and the supporting substrate to be firmly adhered by curing. Usually, the amount is such that the thickness of the coating film of the adhesive paste is 0.5 ⁇ m or more and 5 ⁇ m or less, preferably 1 ⁇ m or more and 3 ⁇ m or less.
• the semiconductor element is fixed to the supporting substrate by heating and curing the adhesive paste of the obtained press-fit.
• the heating temperature and heating time are as described in the section 1) Adhesive paste.
• the semiconductor element is satisfactorily mounted on the adhesive paste and fixed with high adhesive strength in the wire bonding process, and thermal deterioration is reduced. or prevented.
• curable organopolysiloxane compound (A1) had a mass average molecular weight (Mw) of 7,800 and a molecular weight distribution (Mw/Mn) of 4.52. IR spectrum data of the curable organopolysiloxane compound (A1) are shown below. Si—CH 3 : 1272 cm ⁇ 1 , 1409 cm ⁇ 1 , Si—O: 1132 cm ⁇ 1
• Example 1 To 100 parts of curable organopolysiloxane compound (A1), 73 parts of solvent (S), 160 parts of thermally conductive filler (T1), 30 parts of silane coupling agent (B1), and 3 parts of silane coupling agent (B2) are added. In addition, by thoroughly mixing and defoaming the entire contents, an adhesive paste 1 having a solid content concentration of 80% was obtained.
• 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.
• volume filling rate (vol%) [volume of (T) component (cm 3 )/[volume of (T) component (cm 3 ) + volume of component excluding (T) component among solids of adhesive paste (cm 3 )]] ⁇ 100
• the density of the components other than the (T) component in the solid content of the adhesive paste is 1.2 g/cm 3 . published on October 20), the density of titanium oxide ((T1) component) is 4.17 g/cm 3 , the density of alumina ((T2) component, (T3) component and (T4) component) is 4.0 g/cm 3.
• Magnesium carbonate (component (T5)) with a density of 3.04 g/cm 3 and aluminum nitride (component (T6)) with a density of 3.05 g/cm 3 were used.
• Thermal conductivity measurement The adhesive pastes obtained in Examples and Comparative Examples were poured into a Teflon (registered trademark) frame of 10 mm long ⁇ 10 mm wide ⁇ 0.2 mm high, and cured by heating at 120 ° C. for 4 hours. got a piece Then, the thermal diffusivity of this test piece was measured by the temperature wave method using a thermal diffusivity measuring device (ai-Phase Mobile 1, manufactured by i-Phase). In addition, among the components constituting the cured product obtained by heating and curing the adhesive paste, the components excluding the thermally conductive filler (T) have a specific heat of 1 J/(g K) and a density of 1.2 g/cm 3 .
• This adherend with the test piece is left on the measurement stage of a bond tester (manufactured by Daisy, series 4000) at 100 ° C. for 60 seconds, and is adhered at a speed of 200 ⁇ m / s from a position 100 ⁇ m above the adherend. A stress was applied in the horizontal direction (shearing direction) to the surface, and the adhesive strength (N/mm square) between the test piece and the adherend at 100°C was measured.
• the optical semiconductor element in the test piece for thermal deterioration evaluation is made to emit light at a current value of 250 mA, and the initial luminous flux and the luminous flux after 1000 hours of energization time are measured using a measuring device (manufactured by MentorGraphics, T3Ster/TeraLED).
• the luminous flux maintenance rate (%) [[luminous flux (lm) after 1000 hours of energization time/initial luminous flux (lm)] ⁇ 100] is calculated, and the thermal deterioration of the semiconductor element is evaluated according to the following criteria. did. Excellent: The luminous flux maintenance rate was 97% or more. Good: The luminous flux maintenance rate was 95% or more and less than 97%. Fair: The luminous flux maintenance rate was 93% or more and less than 95%. Poor: Luminous flux maintenance rate was less than 93%.
• the adhesive pastes obtained in Examples and Comparative Examples were each applied to the mirror surface of a square silicon chip (#2000 grinding, 200 ⁇ m thick) with a side length of 1 mm (area of 1 mm 2 ), and the coated surface was covered.
• the adhesive paste was press-bonded onto an object [electroless silver-plated copper plate (silver-plated surface average roughness Ra: 0.025 ⁇ m)] so that the thickness of the adhesive paste after press-bonding was about 3 ⁇ m. Then, it was cured by heat treatment at 170° C. for 2 hours to obtain an adherend with a test piece.
• Tables 1 and 2 reveal the following.
• the adhesive pastes 1 to 8 of Examples 1 to 8 have high thermal conductivity in the cured products obtained by heat curing, and the cured products obtained by heating at a high temperature have excellent adhesiveness. Therefore, when the cured product obtained by heating the adhesive pastes 1 to 8 is used, the thermal deterioration of the semiconductor element can be reduced, and the peeling of the semiconductor element can be reduced or prevented in the wire bonding process. be able to. Since alumina has a higher thermal conductivity than titanium oxide, the adhesive paste 2 containing alumina (T2) as the (T) component is compared with the adhesive paste 1 containing titanium oxide (T1). Thus, a cured product having higher thermal conductivity can be obtained.
• An adhesive paste containing a thermally conductive filler (T) with a large average particle size can obtain a cured product with a higher thermal conductivity, and the adhesive strength of the cured product obtained by heating at a high temperature Excellent. Therefore, when a cured product obtained by heating and curing an adhesive paste containing a thermally conductive filler (T) having a large average particle size is used, peeling of the semiconductor element can be further reduced or prevented in the wire bonding process. Yes (Examples 2-4).
• adhesive pastes 5 and 6 which have a high content of (T) component with respect to 100 parts by mass of the solid content of the adhesive paste, have a higher thermal conductivity than adhesive paste 4, which has a low content of (T) component. A cured product can be obtained.
• the adhesive paste 6 has a large content of the (T) component, but a small content of the (B) component and the (B1) component with respect to 100 parts by mass of the solid content of the adhesive paste.
• the adhesiveness of the resulting cured product is slightly reduced (Examples 4-6).
• the adhesive paste contains a thermally conductive filler (T2) with a small average particle size, the adhesive pastes 7 and 4r with a large content thereof can provide a cured product with high thermal conductivity.
• the adhesive paste 7 has a relatively large content of the components (B) and (B1) with respect to 100 parts by mass of the solid content of the adhesive paste, the cured product obtained by heating the adhesive paste at a high temperature has more adhesiveness. It will be excellent for (Example 7 and Comparative Example 4).
• the adhesive paste 8 containing aluminum nitride (T6) as the (T) component a cured product with high thermal conductivity can be obtained, like the adhesive paste 4 containing alumina (T4).
• the cured product obtained by heating at a high temperature has excellent adhesiveness (Examples 4 and 8). That is, by selecting the content of the thermally conductive filler (T), the optimum adhesive paste can be obtained in consideration of the type of semiconductor element, the temperature at which the adhesive paste is cured, and the like.
• the adhesive paste 1r of Comparative Example 1 is an adhesive paste that does not contain a thermally conductive filler (T), the thermal conductivity of the cured product obtained by heating and curing is low. Therefore, when this cured product was used, thermal deterioration of the semiconductor element was observed.
• the adhesive paste 2r of Comparative Example 2 has a small content of the (T) component with respect to 100 parts by mass of the solid content of the adhesive paste, the thermal conductivity of the cured product obtained by heat curing is low. Therefore, when this cured product was used, thermal deterioration of the semiconductor element was observed.
• the adhesive paste 3r of Comparative Example 3 contains magnesium carbonate as a thermally conductive filler (T), and is relatively difficult to mix with the component (A) produced in Production Example 1. ), the area of the thermally conductive filler (T) that can cover the component is small, so the cured product obtained by heating the adhesive paste at a high temperature does not exhibit sufficient adhesive strength. Therefore, when this cured product was used, peeling of the semiconductor element was observed in the wire bonding process.

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• Inorganic Chemistry (AREA)
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