Resin composition

Abstract

This resin composition contains a linear polysiloxane (A) having at least one alkenyl group bonded to a silicon atom in the molecule, a hydrogen polyorganosiloxane (B), a thermally conductive filler (C), and a platinum catalyst (D). The viscosity of the linear polysiloxane (A) is 100 mPa∙s or less at 25° C, and the amount of substance of alkenyl groups bonded to silicon atoms is 8.3-26.0 μmol / g relative to the entire resin composition. The hydrogen polyorganosiloxane (B) content is 1.0-50.0 mass parts per 100 mass parts of the linear polysiloxane (A). The thermally conductive filler (C) content is more than 80 vol% relative to the entire resin composition. The platinum catalyst (D) content relative to the linear polysiloxane (A) is 0.1-1000 mass ppm in terms of elemental platinum.

Description

resin composition

[0001] The present invention relates to a resin composition.

[0002] As electronic devices become more powerful, semiconductor elements are becoming increasingly dense and highly packaged. This has made it important to more efficiently dissipate heat generated by electronic components that make up electronic devices. For example, in semiconductor devices, heat dissipation members are used to efficiently dissipate heat generated by electronic components. Heat dissipation members are materials that reduce the thermal resistance of the path through which heat generated by semiconductor elements is released to a heat sink or housing, and are used in a variety of forms, such as sheets, gels, and greases. A typical heat dissipation member is a resin composition in which a thermally conductive filler such as aluminum nitride is filled into silicone, which has excellent heat resistance (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses that resin compositions used as heat dissipation components are required to have a viscosity that is easy to handle when applied to electronic components and to have a certain degree of elasticity after curing to cushion the electronic components. Furthermore, when heat is required for curing, a high curing rate is desirable to avoid adverse effects such as deformation of the electronic components. It also discloses that by using a certain amount or more of a polysiloxane resin having at least one siloxane with a curable functional group at one site within the molecule, a resin composition can be provided that exhibits an excellent curing rate and is easy to handle while achieving appropriate viscosity / hardness and thermal conductivity.

[0004] International Publication No. 2018 / 221662

[0005] Resin compositions used as heat dissipation components are required to have good dischargeability that allows for easy handling when applied to electronic components, and to have high thermal conductivity. Furthermore, with the recent increase in the size of semiconductors, warping of semiconductor substrates during heat treatment during manufacturing has become an issue, and to suppress this, resin compositions that can be rapidly cured at room temperature are required. The resin composition of Patent Document 1 has good thermal conductivity and good handleability when applied to electronic components, but it is difficult to rapidly cure at room temperature. In practice, curing must be performed under heating conditions such as 70°C, leaving room for improvement in terms of rapid room temperature curing. Therefore, an object of the present invention is to provide a resin composition that has good dischargeability, high thermal conductivity, and allows for rapid room temperature curing.

[0006] To solve the above-mentioned problems, the present inventors conducted extensive research. To improve the thermal conductivity of a resin composition, it is necessary to increase the content of a thermally conductive filler, but doing so reduces the ejection properties of the resin composition. Therefore, to achieve good ejection properties, a low-viscosity polysiloxane must be used. However, when a low-viscosity polysiloxane is used, the resin composition typically contains a large amount of alkenyl groups, which requires a long time for the curing reaction to complete, making rapid room-temperature curing difficult. In response to this problem, the present inventors discovered that by adjusting the amount of alkenyl groups bonded to silicon atoms relative to the total resin composition, a composition can be obtained that has good ejection properties, high thermal conductivity, and is capable of rapid room-temperature curing. This discovery led to the completion of the present invention.

[0007] That is, the resin composition of the present invention is a resin composition containing a linear polysiloxane (A) having one or more alkenyl groups bonded to silicon atoms in the molecule, a hydrogen polyorganosiloxane (B), a thermally conductive filler (C), and a platinum catalyst (D), wherein the viscosity of the linear polysiloxane (A) having one or more alkenyl groups bonded to silicon atoms in the molecule is 100 mPa s or less at 25°C, and the amount of the silicon-bonded alkenyl groups relative to the entire resin composition is 8.3 to 26.0 μm. mol / g, the content of the hydrogen polyorganosiloxane (B) is 1.0 to 50.0 parts by mass per 100 parts by mass of the linear polysiloxane (A) having one or more alkenyl groups bonded to a silicon atom in the molecule, the content of the thermally conductive filler (C) is greater than 80% by volume with respect to the entire resin composition, and the platinum catalyst (D) is 0.1 to 1000 ppm by mass relative to the linear polysiloxane (A) having one or more alkenyl groups bonded to a silicon atom in the molecule. The linear polysiloxane (A) having one or more alkenyl groups bonded to a silicon atom in the molecule preferably contains 30% by mass or more of a linear polysiloxane having one alkenyl group in the molecule. The ratio (MH / MA) of the molar amount of hydrogen atoms directly bonded to silicon atoms (MH) to the molar amount of alkenyl groups directly bonded to silicon atoms (MA) is preferably 0.7 to 3.0.

[0008] Another aspect of the present invention is a cured product of the resin composition, and an electronic part including the cured product.

[0009] The present invention provides a resin composition that maintains coatability, is easy to handle, and allows rapid room-temperature curing, even when a high thermal conductive filler is added to impart high thermal conductivity. This allows a resin composition with high thermal conductivity to be cured under mild conditions, making it easier to suppress warpage of semiconductor substrates during semiconductor manufacturing.

[0010] An example of an embodiment of the present invention will be described in detail below. However, the present invention is not limited to the embodiment described below, and can be implemented with any modifications within the scope of the gist of the present invention.

[0011] Linear Polysiloxane (A) Having One or More Alkenyl Groups Bonded to Silicon Atoms in the Molecule The resin composition of the present invention contains a linear polysiloxane (A) having one or more alkenyl groups bonded to silicon atoms in the molecule (hereinafter sometimes simply referred to as "linear polysiloxane (A)").

[0012] The linear polysiloxane (A) may be, for example, a polysiloxane represented by the average composition formula R ｘ ｊ R ｙ ｋ SiO 〔４－（ｊ＋ｋ）〕／２ Examples of polyorganosiloxanes include those represented by the following formula:

[0013] R ｘ is an alkenyl group. The alkenyl group is preferably a group having 2 to 8 carbon atoms, and examples thereof include a vinyl group, an aryl group, a 1-butenyl group, and a 1-hexenyl group, and is preferably a vinyl group.

[0014] The number of alkenyl groups bonded to silicon atoms in one molecule of linear polysiloxane (A) is not particularly limited as long as it is one or more, and a plurality of such alkenyl groups may be contained in one molecule. The alkenyl group may be bonded to a silicon atom at the end of the molecular chain, to a silicon atom in the middle of the molecular chain, or to both. From the viewpoints of curing rate and physical properties of the cured product, the linear polysiloxane (A) preferably has at least one alkenyl group bonded to a silicon atom at the end of the molecular chain.

[0015] R ｙ is a substituted or unsubstituted monovalent hydrocarbon group. ｙ The number of carbon atoms in R is preferably 1 to 12, more preferably 1 to 10. ｙExamples of R include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, hexyl, octyl, decyl, and dodecyl; cycloalkyl groups such as cyclopentyl, cyclohexyl, and cyclobutyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl; and groups in which some or all of the hydrogen atoms have been substituted with halogen atoms such as chlorine, fluorine, and bromine, or with cyano groups. Examples of groups in which some or all of the hydrogen atoms have been substituted with halogen atoms or cyano groups include halogenated hydrocarbon groups such as chloromethyl, trifluoropropyl, chlorophenyl, bromophenyl, dibromophenyl, tetrachlorophenyl, fluorophenyl, and difluorophenyl, and cyanoalkyl groups such as α-cyanoethyl, β-cyanopropyl, and γ-cyanopropyl. ｙ Among these, is preferably an alkyl group or an aryl group, and more preferably a methyl group, a butyl group, or a phenyl group.

[0016] j and k are positive numbers that satisfy 0<j<3, 0<k<3, and 1<j+k<3, preferably 0.0005≦j≦1, 1.5≦k<2.4, and 1.5<j+k<2.5, and more preferably 0.001≦j≦0.5, 1.8≦k≦2.1, and 1.8<j+k≦2.2.

[0017] The viscosity of the linear polysiloxane (A) at 25°C is 100 mPa·s or less, preferably 50 mPa·s or less, and more preferably 30 mPa·s or less, in order to achieve both an appropriate viscosity and high thermal conductivity in the resin composition. The lower limit of the viscosity is not particularly limited, but can be, for example, 0.01 mPa·s or more, particularly 0.1 mPa·s or more. The viscosity in the present invention is measured using a rheometer (Discovery HR-20, manufactured by TA Instruments). Specifically, the viscosity was measured using a conical plate with a diameter of 40 mm and a cone angle of 2.0°, a Peltier plate, and a shear rate of 100 s －１ The viscosity is measured until it reaches a steady state value, which is the viscosity to be measured.

[0018] The content of linear polysiloxane (A) in the resin composition of the present invention is an amount such that the amount of alkenyl groups bonded to silicon atoms in the entire resin composition is 8.3 to 26.0 μmol / g. In order to increase the filler loading rate in the entire resin composition and thereby improve thermal conductivity, it is important to reduce the viscosity of the resin. The loading rate can be increased by reducing the molecular chain length. However, as the viscosity of the polysiloxane is generally reduced, the amount of alkenyl groups contained in the entire resin composition increases, resulting in excess alkenyl groups in the entire resin composition, making it difficult to achieve rapid curing at room temperature. On the other hand, in the present invention, by limiting the amount of alkenyl groups contained in the entire resin composition to 8.3 to 26.0 μmol / g, it is believed that rapid room-temperature curing can be achieved while achieving a high filler loading.

[0019] The amount of silicon-bonded alkenyl groups in the entire resin composition is preferably 9.0 μmol / g or more, more preferably 10.0 μmol / g or more, and preferably 22.0 μmol / g or less, more preferably 20.0 μmol / g or less.

[0020] The linear polysiloxane (A) may be used alone or in combination of two or more. The linear polysiloxane (A) contains at least one linear polysiloxane having one alkenyl group in the molecule, preferably at least 30 mass%, more preferably at least 40 mass%, and even more preferably at least 80 mass%, based on the total amount of the linear polysiloxane (A). When the linear polysiloxane (A) contains a linear polysiloxane having one alkenyl group in the molecule, it becomes easy to adjust the amount of silicon-bonded alkenyl groups in the entire resin composition to within the above range. There is no particular upper limit, and the total amount of the linear polysiloxane (A) may be a linear polysiloxane having one alkenyl group in the molecule.

[0021] Hydrogen Polyorganosiloxane (B) The resin composition of the present invention contains a hydrogen polyorganosiloxane (B). The hydrogen polyorganosiloxane (B) is a polyorganosiloxane having a hydrosilyl group (Si—H group) in the molecule, and any known hydrogen polyorganosiloxane can be used without particular limitation.

[0022] The hydrogen polyorganosiloxane (B) may be, for example, a polyorganosiloxane having an average composition formula R ｚ ａ H ｂ SiO ［４－（ａ＋ｂ）］／２ The hydrogen polyorganosiloxane (B) may be used alone or in combination of two or more kinds.

[0023] R ｚ R is a substituted or unsubstituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond. ｚExamples of R include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, hexyl, cyclohexyl, and octyl; aryl groups such as phenyl and tolyl; aralkyl groups such as benzyl and phenylethyl; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as fluorine, chlorine, and bromine, or with cyano groups. Examples of groups in which some or all of the hydrogen atoms have been substituted with halogen atoms or cyano groups include chloromethyl, bromoethyl, trifluoropropyl, and cyanoethyl. ｚ Among these, from the viewpoints of ease of synthesis, cost, etc., is preferably an alkyl group, more preferably a methyl group or a butyl group.

[0024] a and b are numbers that satisfy 0.5≦a≦2, 0<b≦2, and 0.5<a+b≦3, and preferably 0.6≦a≦1.9, 0.01≦b≦1.0, and 0.6<a+b≦2.8. The hydrogen polyorganosiloxane (B) preferably has an average of two or more hydrosilyl groups per molecule.

[0025] The content of the hydrogen polyorganosiloxane (B) in the resin composition is 1.0 to 50.0 parts by mass per 100 parts by mass of the linear polysiloxane (A). The content of the hydrogen polyorganosiloxane (B) is preferably 8.0 parts by mass or more, more preferably 10.0 parts by mass or more, and preferably 40.0 parts by mass or less, more preferably 20.0 parts by mass or less. This allows for rapid room temperature curing.

[0026] Furthermore, the content of hydrogen polyorganosiloxane (B) is preferably adjusted so that the ratio (MH / MA) of the molar amount of hydrogen atoms directly bonded to silicon atoms (molar amount of hydrosilyl groups: MH) to the molar amount of alkenyl groups directly bonded to silicon atoms (MA) in the resin composition is in the range of 0.7 to 3.0. By setting the MH / MA in this range, the resin composition can have a certain degree of elasticity after curing, making it easier to cushion electronic components. MH / MA is more preferably 0.7 to 2.0, and even more preferably 0.7 to 1.0.

[0027] Thermally conductive filler (C) As the thermally conductive filler (C), known ones can be used, for example, aluminum oxide (alumina), magnesium oxide, zinc oxide, boron nitride, aluminum nitride, silica, silicon carbide, metal powder, diamond, aluminum hydroxide and carbon, preferably alumina, zinc oxide, aluminum nitride, boron nitride or silicon carbide, more preferably alumina or aluminum nitride.These thermally conductive fillers can be used without any particular restrictions on commercially available ones.In addition, the thermally conductive filler can also be used in combination with multiple types of different chemical species.

[0028] The thermally conductive filler (C) is preferably an aluminum nitride-based thermally conductive filler. An aluminum nitride-based thermally conductive filler refers to one in which the proportion of aluminum nitride in the total amount of thermally conductive filler is 40% by volume or more. Aluminum nitride has high thermal conductivity, making it easy to obtain a resin composition with high thermal conductivity. The proportion of aluminum nitride in the total amount of thermally conductive filler is preferably 50% by volume or more, more preferably 60% by volume or more.

[0029] The thermally conductive filler (C) preferably includes a filler having an average particle size of 0.08 μm or more and less than 0.8 μm, a filler having an average particle size of 0.8 μm or more and less than 2.0 μm, a filler having an average particle size of 2.0 μm or more and less than 50 μm, and a filler having an average particle size of 50 μm or more and less than 300 μm. By including fillers with such different particle sizes, a structure close to a close-packed structure can be easily obtained when the fillers are efficiently filled into the resin, and high thermal conductivity and high dischargeability can be easily obtained.

[0030] The content of the filler having an average particle size of 0.08 μm or more and less than 0.8 μm is preferably 3 to 15 vol% relative to the total filler. The content is more preferably 4 vol% or more and more preferably 13 vol% or less. The content of the filler having an average particle size of 0.8 μm or more and less than 2.0 μm is preferably 3 to 30 vol% relative to the total filler. The content is more preferably 5 vol% or more and more preferably 28 vol% or less. The content of the filler having an average particle size of 2.0 μm or more and less than 50 μm is preferably 15 to 70 vol% relative to the total filler. The content is more preferably 20 vol% or more and more preferably 60 vol% or less. The content of the filler having an average particle size of 50 μm or more and less than 300 μm is preferably 10 to 64 vol% relative to the total filler. The content is more preferably 15 vol% or more and more preferably 56 vol% or less. The volume ratio of each filler can be calculated by dividing the mass ratio of each filler by the density of each material.

[0031] The average particle size in the present invention is the particle size at 50% cumulative volume in the particle size distribution on a volume basis measured using a laser diffraction particle size distribution analyzer (MICROTRAC-MT3300EXII manufactured by Microtrac-Bell Corporation) in which a thermally conductive filler is dispersed in a solution of 90 ml of water and a 5% aqueous solution of sodium pyrophosphate, and the resulting dispersion is homogenized.

[0032] The shape of the thermally conductive filler (C) is not particularly limited, and for example, any of spherical, rounded, and irregular particles can be used, and at least two of these can also be used in combination.

[0033] The content of the thermally conductive filler (C) in the resin composition of the present invention is greater than 80% by volume relative to the total volume of the resin composition. This allows the thermal conductivity of the resin composition to be increased. The content of the thermally conductive filler (C) is preferably 85% by volume or more and 92% by volume or less in terms of the balance between thermal conductivity and operability.

[0034] The thermally conductive filler (C) may be surface-treated as necessary to improve compatibility with resins and water resistance. Known methods can be used for the surface treatment. For example, surface treatment can be performed using organosilicon compounds such as silicone oil, silylating agents, and silane coupling agents; acids such as phosphoric acid, phosphates, and fatty acids; polymeric compounds such as polyamide resins; and inorganic substances such as alumina and silica. The thermally conductive filler (C) is preferably surface-treated with a silane coupling agent, particularly because it can efficiently improve affinity with resins. The silane coupling agent is preferably a dimethylpolysiloxane in which one molecular chain end is blocked with an alkoxysilyl group, particularly a compound represented by the following chemical formula (1):

[0035]

[0036] (In chemical formula (1), R ３１ is -O- or -CH ２ CH ２ - is. R ３２ are independently unsubstituted or substituted monovalent hydrocarbon groups, preferably alkyl groups or aryl groups, more preferably methyl groups or phenyl groups. ３３ are independently an alkyl group having 1 to 6 carbon atoms, preferably a methyl group, an ethyl group, a propyl group, a butyl group, or a hexyl group; g is an integer of 5 to 100, preferably an integer of 5 to 70, and particularly preferably an integer of 10 to 50; and p is an integer of 1 to 3, preferably 2 or 3.

[0037] The silane coupling agent also includes a compound in which one or more methyl groups in the chemical formula (1) are substituted with a monovalent hydrocarbon group other than a methyl group. Examples of the substituent include groups having 1 to 10 carbon atoms, and specific examples include alkyl groups such as ethyl, propyl, butyl, hexyl, and octyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl and tolyl; aralkyl groups such as 2-phenylethyl and 2-methyl-2-phenylethyl; and halogenated hydrocarbon groups such as 3,3,3-trifluoropropyl, 2-(nonafluorobutyl)ethyl, 2-(heptadecafluorooctyl)ethyl, and p-chlorophenyl. When the thermally conductive filler (C) is prepared by mixing multiple powders, surface treatment may be performed after mixing, or surface treatment may be performed before mixing. When mixing is performed after surface treatment, powders that have been subjected to different surface treatments may be mixed together, or a powder that has been surface treated may be mixed with a powder that has not been surface treated.

[0038] Platinum Catalyst (D) The resin composition of the present invention contains a platinum catalyst, which promotes the addition reaction between the alkenyl groups in the linear polysiloxane (A) and the hydrosilyl groups in the hydrogen polyorganosiloxane (B), thereby enabling the resin composition to be properly cured.

[0039] As the platinum catalyst (D), any known platinum-based catalyst can be used without limitation, and examples thereof include platinum black, platinic chloride, chloroplatinic acid, a reaction product of chloroplatinic acid with a monohydric alcohol, a complex of chloroplatinic acid with an olefin or vinylsiloxane, and platinum bisacetoacetate. One or more types of platinum catalyst (D) may be used.

[0040] The content of the platinum catalyst (D) is 0.1 to 1000 ppm by mass in terms of platinum element relative to the linear polysiloxane (A).

[0041] Depending on the application, the reaction rate may be adjusted by adding a reaction inhibitor to suppress the activity of the catalyst. Known reaction inhibitors for platinum-based catalysts include acetylene alcohols such as 2-methyl-3-butyn-2-ol and 1-ethynyl-2-cyclohexanol, and diallyl maleate.

[0042] The content of the reaction inhibitor is preferably 0.01 to 400 times the content of the platinum catalyst (D) on a mass basis. The content of the reaction inhibitor is more preferably 0.05 times or more, even more preferably 1 time or more, particularly preferably 5 times or more, and more preferably 200 times or less, even more preferably 20 times or less, and particularly preferably 17 times or less. In this way, by adjusting the content of the reaction inhibitor relative to the content of the platinum catalyst (D), the curing reaction can be appropriately delayed. This allows good operability to be maintained when applying the composition to electronic components.

[0043] [Other Components] In addition to the above, the resin composition of the present invention may contain additives such as a surface treatment agent, a plasticizer, a vulcanizing agent, a colorant, and a mold release agent, as needed. For example, by adding a surface treatment agent to the resin composition, the affinity between the thermally conductive filler (C) and the resin can be efficiently improved, similar to when the thermally conductive filler (C) is surface-treated. In this case, the content of the surface treatment agent is preferably 5 to 50 parts by mass per 100 parts by mass of the linear polysiloxane (A). The content of the surface treatment agent is more preferably 10 parts by mass or more and more preferably 45 parts by mass or less. Specific examples of the surface treatment agent include the silane coupling agents described above.

[0044] [Physical Properties of Resin Composition] The thermal conductivity of the resin composition of the present invention, measured by the hot disk method, is preferably 10 W / m K or more, more preferably 15 W / m K or more, and even more preferably 18 W / m K or more. This makes it possible to impart high heat dissipation performance when used as a heat dissipation member, and makes it easy to efficiently cool heat-generating parts of electronic devices.

[0045] The resin composition of the present invention preferably has a dischargeability of 10 g / min or more when filled into a syringe having an inner diameter of a 2 mm tip discharge portion and discharged at a discharge pressure of 0.62 MPa. This characteristic makes the composition easy to handle when applied to electronic components, thereby improving manufacturing efficiency. The dischargeability is preferably 15.0 g / min or more, more preferably 30.0 g / min or more. If the dischargeability is too high, it may be difficult to control the dischargeability during manufacturing, so the dischargeability is preferably 500.0 g / min or less.

[0046] The thickness of the resin composition (hereinafter sometimes referred to as "BLT") measured after sandwiching 0.02 mL of the resin composition between two 10 mm x 10 mm silicon chips and applying a force of 50 N for 60 seconds is preferably 300 μm or less, more preferably 250 μm or less, and even more preferably 200 μm or less. This characteristic allows the resin composition to be easily formed into a thin film, and it can be formed into a thin film form with a simple operation during the manufacture of electronic components. This makes it easy to arrange the resin composition in the form of a thin film on electronic components to reduce thermal resistance and to increase manufacturing efficiency when the resin composition is arranged in the form of a thin film during the manufacture of electronic components.

[0047] [Room Temperature Curability] When the Type E hardness of the resin composition of the present invention after standing at 25°C for 24 hours is defined as E1 and the Type E hardness of the resin composition after further heating at 150°C for 2 hours is defined as E2, the difference between E2 and E1, (E2-E1), is preferably less than 10.

[0048] In the resin composition of the present invention, the Type E hardness increases as the curing reaction between the linear polysiloxane (A) and the hydrogen polyorganosiloxane (B) progresses, and the increase in Type E hardness stops when the curing reaction is complete. The curing reaction can be accelerated by heating. Therefore, if the curing reaction is not complete at 25°C, subsequent heating at 150°C will increase the Type E hardness and increase the (E2-E1) value. On the other hand, if rapid room-temperature curing is possible at room temperature, even if the composition is cured at 25°C and then heated, the increase in Type E hardness will be small. In the present invention, if (E2-E1) is less than 10, it is determined that a rapid curing reaction is possible at 25°C (room temperature). From the perspective of achieving more rapid room-temperature curing, (E2-E1) is preferably 5 or less. By reducing (E2-E1), the progress of the curing reaction during use of electronic components is suppressed, making it easier to suppress peeling and deformation.

[0049] Furthermore, E1 and E2 are not particularly limited, but are preferably each 10 or more and 70 or less. E1 and E2 are more preferably 30 or more, and more preferably 60 or less. Note that when Type E is small and the flexibility of the cured product of the resin composition is high, the ability to conform to the heat-generating body is improved, and heat dissipation performance can be exhibited more efficiently.

[0050] [Method for Producing Resin Composition] The method for producing the resin composition of the present invention is not particularly limited, and the resin composition can be produced by mixing the resin, filler, and other components as needed using a known method such as a blender or mixer. During the mixing, the components may be added simultaneously to a mixer or the like and mixed, or the components may be added sequentially to a mixer or the like and mixed. The order of addition is not particularly limited. Furthermore, if necessary, treatment by heating, decompression, or other known methods may be performed.

[0051] [Form of Resin Composition] The resin composition of the present invention may be a one-component type or a two-component type consisting of a first component and a second component. In the case of a two-component type, the first component and the second component are mixed together to obtain the resin composition. In the case of a two-component type, the resin composition is cured after mixing, so it is important that the requirements of the present invention are met after mixing. The composition of the resin composition after mixing can be calculated from the composition of the first component, the composition of the second component, and the mixed amounts of the first component and the second component. In a two-component resin composition, the mass ratio of the first component to the second component when mixed (first component / second component) is not limited, but is preferably 1.0 or a value close to 1.0, for example, preferably 0.8 to 1.2. The mass ratio is more preferably 0.9 or greater, even more preferably 0.95 or greater, more preferably 1.1 or less, and even more preferably 1.05 or less. Thus, by setting the mass ratio of the first component to the second component when mixed to 1.0 or a value close to 1.0, the resin composition can be easily prepared.

[0052] In the case of a two-component resin composition, the method for mixing the first and second components to obtain the resin composition is not limited, and for example, a static mixer, a mixer with stirring blades, a vibration mixer, or a planetary mixer can be used. The first and second components can be produced by mixing the components by a known method using a blender or mixer, as in the case of a one-component resin composition.

[0053] In the two-component resin composition, the first agent contains a linear polysiloxane (A) and a platinum catalyst (D), but does not contain a hydrogen polyorganosiloxane (B), and the second agent contains a hydrogen polyorganosiloxane (B), but preferably does not contain a platinum catalyst (D). All of the linear polysiloxane (A) constituting the resin composition may be contained in the first agent, but preferably a portion is contained in the first agent and the remainder is contained in the second agent. By dividing the linear polysiloxane (A) into the first agent and the second agent, it becomes easier to adjust the ejection properties of the first agent and the second agent to the desired range, and it also becomes easier to make the mass ratio of the first agent to the second agent 1.0 or close to 1.0.

[0054] The hydrogen polyorganosiloxane (B) constituting the resin composition is preferably contained entirely in the second agent, and not in the first agent. Such a first agent contains a platinum catalyst (D) that promotes the curing reaction, but does not contain the hydrogen polyorganosiloxane (B), so that the curing reaction can be prevented from proceeding before mixing with the second agent.

[0055] The second agent contains hydrogen polyorganosiloxane (B) but does not contain platinum catalyst (D) that promotes the curing reaction, so the curing reaction can be prevented from progressing before mixing with the first agent. The second agent also contains hydrogen polyorganosiloxane (B) but does not contain platinum catalyst (D), so even if it contains linear polysiloxane (A), the curing reaction can be substantially prevented from progressing during storage, etc. The second agent may contain a reaction inhibitor to further reliably prevent the reaction from progressing.

[0056] It is preferable that the thermally conductive filler (C) is contained in at least one of the first and second agents, and it is more preferable that the thermally conductive filler (C) is contained in both the first and second agents.

[0057] When the thermally conductive filler (C) is contained in both the first and second agents, it is more preferable that it be contained approximately equally in the first and second agents. Specifically, the ratio (mass ratio) of the content of the thermally conductive filler (C) in the second agent to the content of the thermally conductive filler (C) in the first agent is preferably 0.67 to 1.5. This content ratio is more preferably 0.83 or more, even more preferably 0.91 or more, and more preferably 1.2 or less, even more preferably 1.1 or less. By distributing the thermally conductive filler (C) approximately equally in the first and second agents, it becomes easier to reduce the difference in ejection properties between the first and second agents and also makes it easier to bring the mass ratio of the first and second agents when mixed closer to 1.0.

[0058] [Method for curing resin composition] The resin composition of the present invention can be cured by a hydrosilylation reaction between the linear polysiloxane (A) and the hydrogen polyorganosiloxane (B) to form a cured product. The shape of the cured product is not limited, and it can be molded into a sheet or other shape to match the shape of an electronic component. In addition, when applying to an electronic component, the composition can be applied directly to a heat generating element and cured under pressure, allowing it to be molded in a state that conforms to the heat generating element, thereby more efficiently exhibiting heat dissipation performance.

[0059] The temperature for curing is not particularly limited, but is preferably room temperature, for example, 5°C to 35°C, particularly 15°C to 30°C, as this allows the effects of the present invention to be particularly exhibited. When the resin composition is a one-component type, it is stored under low-temperature conditions such as refrigeration or freezing to prevent curing before use, and is then stored at room temperature or the curing temperature before curing, and thawed. In this case, it is preferably applied to an electronic component and cured within 6 hours. When using a two-component resin composition, the two components are preferably mixed together immediately before the curing treatment, applied to an electronic component, and cured.

[0060] [Uses of Resin Composition] The resin composition can be used as a heat dissipation member (heat dissipation material) for efficiently dissipating heat generated by electronic components mounted in home appliances, automobiles, personal computers, etc., and specific examples thereof include a heat dissipation sheet, a heat dissipation grease, a heat dissipation gel, an adhesive, a semiconductor encapsulant, and an underfill.

[0061] When the resin composition of the present invention is used as a heat dissipation member, by using the resin composition of the present invention between a substrate having a heat-generating portion such as a semiconductor element and a substrate having a cooling portion such as a heat sink or a housing, the heat generated by the electronic component can be efficiently dissipated. Specifically, the resin composition can be used for an electronic component that includes a heat dissipation member containing the resin composition of the present invention, a substrate having a heat-generating portion, and a substrate having a cooling portion, and the heat dissipation member is arranged so as to be in contact with the substrate having the heat-generating portion, particularly an electronic component that is arranged so as to be in contact with both the substrate having the heat-generating portion and the substrate having the cooling portion.

[0062] Examples of the present invention will be described below, but the scope of the present invention is not limited to these examples. Materials used in the examples and comparative examples are as follows.

[0063] [Linear polysiloxane (A) having one or more alkenyl groups bonded to silicon atoms in the molecule] (Linear polysiloxane having one alkenyl group bonded to silicon atoms in the molecule) SiMV1: A compound represented by the following chemical formula (2) having a viscosity of 30 mPa s at 25°C. This compound has an average composition formula R ｘ ｊ R ｙ ｋ SiO 〔４－（ｊ＋ｋ）〕／２ In this case, R ｘ is a vinyl group, R ｙ is a methyl group, j=0.032, and k=2.032.

[0064]

[0065] (Linear polysiloxane having two alkenyl groups bonded to silicon atoms in the molecule) SiDV1: A compound represented by the following chemical formula (3) having a viscosity of 3 mPa·s at 25°C. Note that this compound has n=10 and an average composition formula R ｘ ｊ R ｙ ｋ SiO 〔４－（ｊ＋ｋ）〕／２ In this case, R ｘ is a vinyl group, R ｙ is a methyl group, j=0.067, and k=2.000. SiDV2: A compound represented by the following chemical formula (3), having a viscosity of 100 mPa·s at 25°C. Note that this compound has n=64 and an average composition formula R ｘ ｊ R ｙ ｋ SiO 〔４－（ｊ＋ｋ）〕／２ In this case, R ｘ is a vinyl group, R ｙ is a methyl group, j=0.030, and k=2.000.

[0066]

[0067] [Hydrogenpolyorganosiloxane (B)] CL1: Methylhydrogenpolysiloxane A compound represented by the following chemical formula (4). This compound has the average composition formula R ｚ ａ H ｂ SiO ［４－（ａ＋ｂ）］／２ In this case, R ｚ is a methyl group, a=1.75, and b=0.28.

[0068]

[0069] [Thermal conductive filler (C)] AO1: Aluminum oxide filler (average particle size 0.2 μm, manufactured by Sumitomo Chemical Co., Ltd.) AL1: Aluminum nitride filler (average particle size 1 μm, manufactured by Tokuyama Corporation) AL2: Aluminum nitride filler (average particle size 20 μm, manufactured by Tokuyama Corporation) AL3: Aluminum nitride filler (average particle size 120 μm, manufactured by Tokuyama Corporation) [Platinum catalyst (D)] Pt-DVi4 complex (solution of platinum 1,3-divinyltetramethyldisiloxane complex) [Others] Silane coupling agent: dimethylpolysiloxane in which one end of the molecular chain is blocked with an alkoxysilyl group Reaction inhibitor: 1-ethynyl-1-cyclohexanol

[0070] <Evaluation of Dischargeability> Using a syringe "PSY-30F" manufactured by Musashi Engineering Co., Ltd., the discharge amount per minute (g / min) at 25°C was measured. The inner diameter of the barrel of the syringe where the sample was stored was 22 mm, and the inner diameter of the tip portion from which the sample was discharged was 2 mm. The discharge pressure was 0.62 MPa. In the case of a one-component resin composition, the syringe was filled within one hour after production, and the dischargeability was evaluated. In the case of a two-component resin composition, the two components were mixed at a mass ratio of 1:1, and then the syringe was filled within one hour, and the dischargeability was evaluated.

[0071] <Evaluation of Room-Temperature Curing Properties> The resin composition was poured into an aluminum mold with inner dimensions of 6 mm (depth) x 60 mm (length) x 30 mm (width) and cured in a thermostatic chamber at 25°C for 24 hours. The cured product was removed from the thermostatic chamber and then removed from the mold. The Type E hardness was measured in accordance with JIS K 6249, and hardness E1 was determined. After further heating at 150°C for 2 hours, hardness was measured and hardness E2 was determined. E2-E1 was calculated from the obtained hardnesses E1 and E2. If (E2-E1) was less than 10, it was determined that the curing reaction was nearly complete within 24 hours at 25°C and rapid room-temperature curing was possible. In the case of one-component resin compositions, the resin was immediately poured into a mold after production for evaluation. In the case of two-component resin compositions, the two components were mixed at a mass ratio of 1:1 and then immediately poured into a mold for evaluation.

[0072] <Measurement of Thermal Conductivity> The resin composition was poured into an aluminum mold having inner dimensions of 6 mm (depth) × 60 mm (length) × 30 mm (width), and cured in a thermostatic chamber at 25°C for 24 hours to obtain two measurement samples. The measurement samples were sandwiched between the sensors of a thermal conductivity meter (TPS500, manufactured by Kyoto Electronics Manufacturing Co., Ltd.), and the thermal conductivity was measured.

[0073] Example 1 100 parts by weight of SiMV1, 11.0 parts by weight of CL1, 274 parts by weight of AO1, 611 parts by weight of AL1, 949 parts by weight of AL2, 2084 parts by weight of AL3, 4.0 parts by weight of a platinum-based catalyst (Pt-DVi4 complex) (496 ppm by weight of platinum element relative to the linear polysiloxane (A)), 45 parts by weight of a silane coupling agent (dimethylpolysiloxane in which one end of the molecular chain is blocked with an alkoxysilyl group) relative to the SiMV1, and 15 times the amount of reaction inhibitor (1-ethynyl-1-cyclohexanol) relative to the amount of the platinum-based catalyst were mixed with a blade-type agitator to prepare a resin composition, and the thermal conductivity, dischargeability, E1, and E2 of the resulting resin composition were evaluated. The composition of the resin composition and the evaluation results of the obtained resin composition are shown in Table 1.

[0074] (Examples 2 to 7, Comparative Examples 1 to 3) Resin compositions were obtained and evaluated in the same manner as in Example 1, except that the compositions of the resin components and thermally conductive filler were changed as shown in Tables 1 and 2. The compositions of the resin components and thermally conductive filler, and the evaluation results of the obtained resin compositions are shown in Tables 1 and 2.

[0075] Example 8 A first agent and a second agent were prepared as a two-component resin composition and mixed in a mass ratio of 1:1 to obtain a resin composition having the composition shown in Table 1. The first agent was prepared by mixing 100 parts by mass of SiMV1, 289 parts by mass of AO1, 645 parts by mass of AL1, 1003 parts by mass of AL2, 2246 parts by mass of AL3, 8.2 parts by mass of a platinum-based catalyst (Pt-DVi4 complex) as a catalyst, and 48 parts by mass of a silane coupling agent (dimethylpolysiloxane in which one molecular chain end is blocked with an alkoxysilyl group) relative to the SiMV1 using a blade-type agitator.

[0076] The second agent was prepared by mixing, using a blade-type agitator, 100 parts by mass of SiMV1, 21.2 parts by mass of CL1, 339 parts by mass of AO1, 758 parts by mass of AL1, 1177 parts by mass of AL2, 2638 parts by mass of AL3, 48 parts by mass of a silane coupling agent (dimethylpolysiloxane in which one molecular chain end is blocked with an alkoxysilyl group) relative to the SiMV1, and 15 times the amount of a reaction inhibitor (1-ethynyl-1-cyclohexanol) relative to the amount of the platinum-based catalyst.

[0077] The resulting resin compositions were evaluated for thermal conductivity, ejection properties, E1, and E2. The components of the resin compositions and the evaluation results of the resulting resin compositions are shown in Table 1.

[0078]

[0079]

[0080] In the resin compositions of Examples 1 to 8, the viscosity of the linear polysiloxane was limited to 100 mPa s or less, and the content of the thermally conductive filler was 80% by mass or more, resulting in a thermal conductivity of 10 W / m K or more. The dischargeability was 15.0 g / min or more, and the composition had high thermal conductivity and good dischargeability. Furthermore, since the amount of alkenyl groups bonded to silicon atoms in the entire resin composition was in the range of 8.3 to 26.0 μmol / g, and the content of hydrogen polyorganosiloxane (B) was 1.0 to 50.0 parts by mass per 100 parts by mass of linear polysiloxane (A), the curing reaction was almost complete after 24 hours of curing at 25 ° C., allowing for rapid room temperature curing. On the other hand, in Comparative Examples 1 and 3, the amount of silicon-bonded alkenyl groups relative to the total resin composition exceeded 26.0 μmol / g, and the curing reaction was not completed after 24 hours of curing at 25°C, preventing rapid room-temperature curing. Furthermore, in Comparative Example 2, rapid room-temperature curing was also not achieved. This is presumably because the content of the hydrogen polyorganosiloxane (B) component corresponding to the linear polysiloxane (A) was greater than 50.0 parts by mass, and unreacted hydrogen organosiloxane remained in the resin composition after the hydrosilylation reaction was completed, and subsequent heating caused a condensation reaction between the unreacted hydrosilyl groups.

Claims

1. A resin composition comprising a linear polysiloxane (A) having one or more silicon-bonded alkenyl groups in the molecule, a hydrogen polyorganosiloxane (B), a thermally conductive filler (C), and a platinum catalyst (D), wherein the viscosity of the linear polysiloxane (A) having one or more silicon-bonded alkenyl groups in the molecule is 100 mPa·s or less at 25°C, the amount of silicon-bonded alkenyl groups in the entire resin composition is in the range of 8.3 to 26.0 μmol / g, the content of the hydrogen polyorganosiloxane (B) is 1.0 to 50.0 parts by mass per 100 parts by mass of the linear polysiloxane (A) having one or more silicon-bonded alkenyl groups in the molecule, and the content of the thermally conductive filler (C) is greater than 80% by volume in the entire resin composition. a resin composition in which the content of the platinum catalyst (D) relative to the linear polysiloxane (A) having one or more alkenyl groups bonded to silicon atoms in the molecule is 0.1 to 1000 ppm by mass in terms of platinum element.

2. The resin composition according to claim 1, wherein the linear polysiloxane (A) having one or more alkenyl groups bonded to silicon atoms in the molecule contains 30% by mass or more of linear polysiloxanes having one alkenyl group in the molecule.

3. The resin composition according to claim 1, wherein the ratio of the amount of hydrogen atoms directly bonded to silicon atoms (MH) to the amount of alkenyl groups directly bonded to silicon atoms (MA) (MH / MA ratio) is in the range of 0.7 to 3.

0.

4. A cured product of the resin composition according to any one of claims 1 to 3.

5. An electronic part comprising the cured product according to claim 4.

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