Method for producing thermosetting resin composition, thermosetting resin composition, and electronic component device

Abstract

To provide a method for producing a thermosetting resin composition which maintains good fluidity and is excellent in strength when formed into a cured product, a thermosetting resin composition obtained by the production method, and an electronic component device including an element sealed with the thermosetting resin composition.SOLUTION: The method for producing a thermosetting resin composition includes: primary kneading in which a mixture of a thermosetting resin, an inorganic filler, and a coupling agent is kneaded at 100°C or higher; and secondary kneading in which a curing accelerator is added and kneading is further performed after the primary kneading.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a thermosetting resin composition, a thermosetting resin composition, and an electronic component device.

Background Art

[0002] As a material for encapsulating semiconductor elements and the like, thermosetting resin compositions are widely used. As a general method for preparing a thermosetting resin composition, a method of mixing and kneading a thermosetting resin and an inorganic filler is employed.

[0003] In a thermosetting resin composition containing an inorganic filler, a coupling agent may be used in combination to enhance the dispersibility of the inorganic filler. By mixing the inorganic filler with the coupling agent or surface-treating the inorganic filler with the coupling agent, the affinity between the inorganic filler and the resin component can be enhanced. As methods for mixing the inorganic filler with the coupling agent or surface-treating the inorganic filler with the coupling agent, a dry treatment method, a wet treatment method, an integral blend method, etc. are employed (see, for example, Patent Documents 1 and 2). The dry treatment method is a method of surface-treating the inorganic filler by previously mixing the inorganic filler with the coupling agent under solvent-free conditions. The wet treatment method is a method of surface-treating the inorganic filler by previously mixing the inorganic filler and the coupling agent in the presence of a solvent. The integral blend method is a method of adding and mixing the coupling agent together when mixing the resin component and the inorganic filler, and the coupling agent reacts with the inorganic filler on the one hand and interacts with the resin component on the other hand to enhance the dispersibility of the inorganic filler.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The integral blending method may be preferably adopted in terms of simplicity, curability, and the physical properties of the cured product, as compared with methods such as dry treatment methods and wet treatment methods for pretreatment. Since the reaction between the inorganic filler and the coupling agent preferably proceeds at a specific temperature or higher, in order to efficiently improve the dispersibility of the inorganic filler by the integral blending method, it is desirable to knead the resin mixture containing the inorganic filler and the coupling agent at a temperature equal to or higher than the reaction temperature of the inorganic filler and the coupling agent, for example, 100°C or higher. On the other hand, when kneading the resin mixture containing the inorganic filler and the coupling agent at a high temperature in the integral blending method, the resin mixture may thicken and sufficient mixing may not be achieved, leading to a decrease in curability and a consequent decrease in the strength of the cured product. Further, if the resin is unevenly distributed due to insufficient kneading, the fluidity during molding may decrease. Furthermore, when applying a high shear stress to achieve sufficient mixing, thickening is accelerated by shear heating.

[0006] In view of such circumstances, an object of the present disclosure is to provide a method for producing a thermosetting resin composition that maintains good fluidity and has excellent strength when formed into a cured product, a thermosetting resin composition obtained by the production method, and an electronic component device including an element sealed with the thermosetting resin composition.

Means for Solving the Problems

[0007] The means for solving the above problems includes the following aspects. <1> Primary kneading in which a mixture of a thermosetting resin, an inorganic filler, and a coupling agent is kneaded at 100°C or higher, Secondary kneading in which a curing accelerator is added after the primary kneading and further kneaded, A method for producing a thermosetting resin composition, including the above. <2> The production method according to <1>, wherein the temperature of the secondary kneading is lower than the temperature of the primary kneading. <3> The manufacturing method according to <1> or <2>, wherein the temperature of the secondary kneading is lower than the onset temperature measured by differential scanning calorimetry of the mixture after adding the curing accelerator. <4> The manufacturing method according to any one of <1> to <3>, wherein the onset temperature measured by differential scanning calorimetry of the mixture after adding the curing accelerator is lower than 120°C. <5> The manufacturing method according to any one of <1> to <4>, wherein the volume average particle diameter of the inorganic filler is 20 μm or less. <6> A thermosetting resin composition obtained by the manufacturing method according to any one of <1> to <5>. <7> An electronic component device including an element encapsulated with the thermosetting resin composition obtained by the manufacturing method according to any one of <1> to <5>.

Advantages of the Invention

[0008] According to the present disclosure, there are provided a manufacturing method of a thermosetting resin composition that maintains good fluidity and is excellent in strength when formed into a cured product, a thermosetting resin composition obtained by the manufacturing method, and an electronic component device including an element encapsulated with the thermosetting resin composition.

Brief Description of the Drawings

[0009]

Figure 1

Modes for Carrying Out the Invention

[0010] Hereinafter, modes for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values and their ranges, which do not limit the present invention.

[0011] In the present disclosure, the term "step" includes not only a step independent of other steps, but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved. In the numerical range indicated by "~" in the present disclosure, the numerical values described before and after "~" are included as the minimum value and the maximum value, respectively. In the numerical ranges described step by step in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Also, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. In the present disclosure, each component may contain a plurality of corresponding substances. When there are a plurality of substances corresponding to each component in the composition, the content or the amount of each component means the total content or the amount of the plurality of substances present in the composition, unless otherwise specified. In the present disclosure, the particles corresponding to each component may contain a plurality of types. When there are a plurality of types of particles corresponding to each component in the composition, the particle diameter of each component means the value for the mixture of the plurality of types of particles present in the composition, unless otherwise specified. In the present disclosure, "solid", "solid state", "liquid state", and "liquid" refer to the properties at 25°C. When an embodiment is described with reference to the drawings in the present disclosure, the configuration of the embodiment is not limited to the configuration shown in the drawings. Also, the sizes of the members in each figure are conceptual, and the relative relationships of the sizes between the members are not limited thereto.

[0012] ≪Method for Producing Thermosetting Resin Composition≫ The method for producing a thermosetting resin composition of the present disclosure (hereinafter also referred to as the production method of the present disclosure) includes a primary kneading step of kneading a mixture of a thermosetting resin, an inorganic filler, and a coupling agent at 100°C or higher, and a secondary kneading step of adding a curing accelerator after the primary kneading and further kneading. According to the production method of the present disclosure, since the inorganic filler and the coupling agent can react at 100°C or higher in the primary kneading, the dispersibility of the inorganic filler is enhanced, and it is considered that the fluidity when molding the thermosetting resin composition can be improved. Further, by adding the curing accelerator later, it is considered that thickening in the primary kneading can be suppressed, and uneven distribution of each component can be suppressed. As a result, it is considered that good fluidity and curability can be achieved.

[0013] [Primary Kneading] In the primary kneading, a mixture of a thermosetting resin, an inorganic filler, and a coupling agent is kneaded at 100°C or higher. At this time, other components may be further mixed as necessary. In the primary kneading, as long as the influence of thickening on the kneadability does not pose a practical problem, a part of the curing accelerator may be mixed. In the present disclosure, when the curing accelerator is added in multiple portions, for convenience, the kneading after adding more than half, that is, 50% by mass or more of the total curing accelerator finally added, is referred to as secondary kneading. When a part of the curing accelerator is mixed in the primary kneading, the amount to be mixed is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less of the total curing accelerator finally added. Preferably, in the primary kneading, the thermosetting resin, the inorganic filler, the coupling agent, and other additives as necessary are kneaded without adding the curing accelerator.

[0014] The kneading method in the primary kneading is not particularly limited. For example, a method of melt-kneading using a kneader (twin-screw kneader, triple-screw kneader, etc.), a roll (three-roll, etc.), an extruder, etc. that have been preheated to a desired temperature can be mentioned.

[0015] The temperature of the primary kneading is 100°C or higher, and it is preferably adjusted according to the reaction temperature between the inorganic filler and the coupling agent, etc. The temperature of the primary kneading may be 110°C or higher, or may be 120°C or higher. By performing the primary kneading at such a temperature, the reaction between the inorganic filler and the coupling agent tends to proceed favorably, and the dispersibility of the components also tends to be enhanced. From the viewpoint of efficiently suppressing the increase in viscosity during kneading, the temperature of the primary kneading may be 200°C or lower. From such a viewpoint, the temperature of the primary kneading may be 100°C to 200°C, may be 110°C to 200°C, or may be 120°C to 200°C.

[0016] The temperature of the primary kneading is preferably higher than the melting point or softening point of the thermosetting resin (when a plurality of thermosetting resins are used in combination, the thermosetting resin having the highest melting point or softening point). For example, the temperature of the primary kneading is preferably 1°C to 90°C higher than the melting point or softening point of the thermosetting resin (when a plurality of thermosetting resins are used in combination, the thermosetting resin having the highest melting point or softening point), more preferably 1°C to 70°C higher, and even more preferably 1°C to 50°C higher. By performing kneading at such a temperature, the thermosetting resin can be melted to maintain fluidity, so that good stirring and mixing can be performed.

[0017] The shear conditions in the primary kneading are not particularly limited. According to the production method of the present disclosure, since the thickening of the mixture in the primary kneading can be suppressed, even if the shear stress and shear rate are increased compared with the conventional method, it tends to be possible to perform kneading favorably.

[0018] 〔Secondary kneading〕 Subsequent to the primary kneading, a curing accelerator is added and further secondary kneading is performed. The method of adding the curing accelerator is not particularly limited as long as the curing accelerator can be added later. For example, a method of adding the curing accelerator from an inlet provided separately from the inlet for the components of the primary kneading to the mixture obtained by performing the primary kneading as described above (side feed) can be mentioned.

[0019] The temperature during kneading in the secondary kneading is not particularly limited, and from the viewpoint of suppressing thickening, it is preferably lower than the temperature of the primary kneading. The temperature of the secondary kneading is preferably lower than 120°C, more preferably lower than 110°C, and even more preferably lower than 100°C.

[0020] The temperature of the secondary kneading is preferably lower than the onset temperature measured by differential scanning calorimetry (DSC) of the mixture after adding the curing accelerator during the secondary kneading, for example, 1°C to 100°C lower. Thereby, thickening during the secondary kneading can be suppressed. In the present disclosure, the onset temperature refers to the temperature corresponding to the intersection of the tangent line at the point where the differential value of the exothermic peak of the DSC chart is maximum and the baseline of the exothermic peak of the DSC chart. When there are a plurality of points where the differential value of the exothermic peak is maximum, the point on the lowest temperature side among the plurality of points is adopted.

[0021] The onset temperature measured by differential scanning calorimetry (DSC) of the mixture after adding the curing accelerator during the secondary kneading may be lower than 120°C, may be lower than 110°C, or may be lower than 100°C. According to the manufacturing method of the present disclosure, since the primary kneading and the secondary kneading performed by adding the curing accelerator are sequentially performed, regardless of the onset temperature of the mixture after adding the curing accelerator, the temperature of the primary kneading can be set to 100°C or higher. Thereby, the primary kneading can be performed at a temperature at which the reaction between the inorganic filler and the coupling agent proceeds well, and for example, at a temperature at which the resin component is sufficiently melted, and the dispersibility of the resin component and the inorganic filler can be enhanced.

[0022] In addition to the primary kneading and the secondary kneading, the manufacturing method of the present disclosure may include other processes at any timing. For example, prior to the primary kneading, each component may be mixed at room temperature using a mixer or the like. Further, any component other than the thermosetting resin, the inorganic filler, the coupling agent, and the curing accelerator may be added and kneaded simultaneously with or at a different time from one or more of the components of the thermosetting resin, the inorganic filler, the coupling agent, and the curing accelerator. The composition obtained through the primary kneading and the secondary kneading may be cooled and pulverized to obtain a solid thermosetting resin composition.

[0023] In one aspect, the primary kneading and the secondary kneading in the manufacturing method of the present disclosure can be performed using a kneading extruder. A schematic cross-sectional view of the kneading extruder that can be used in one aspect is shown in FIG. 1. The kneading extruder 10 includes a first kneading section A, a second kneading section B disposed downstream in the extrusion direction of the first kneading section A, a main material inlet 1 connected to the first kneading section A, and a side feeder 2 connected to the second kneading section B. In FIG. 1, the arrow represents the extrusion direction of the composition. The thermosetting resin, the inorganic filler, and the coupling agent are simultaneously or sequentially introduced into the first kneading section A from the main material inlet 1, and the curing accelerator is introduced into the second kneading section B from the side feeder 2. The primary kneading is performed in the first kneading section A, and the kneaded material is extruded and moved to the second kneading section B. The moved kneaded material merges with the curing accelerator and is further kneaded. It is also possible to set the temperature of the primary kneading and the temperature of the secondary kneading respectively. For example, a cooling section (not shown) may be provided between the first kneading section A and the second kneading section B, and the secondary kneading may be performed at a lower temperature than the primary kneading. Further, the first kneading section A may be set at a higher temperature and the second kneading section B may be set at a lower temperature, or a mechanism for gradually cooling the content in the extrusion direction may be adopted in the second kneading section B. Note that the manufacturing method of the present disclosure is not limited to the aspect of the drawings.

[0024] Hereinafter, each component used in the manufacturing method of the present disclosure, that is, each component included in the thermosetting resin composition will be described.

[0025] <Thermosetting resin> The type of the thermosetting resin is not particularly limited, and examples thereof include epoxy resins, phenolic resins, urea resins, melamine resins, urethane resins, silicone resins, unsaturated polyester resins, and the like. In the present disclosure, those exhibiting both thermoplastic and thermosetting properties, such as acrylic resins containing epoxy groups, are included in the "thermosetting resin". The thermosetting resin may be solid or liquid under normal temperature and pressure (for example, 25 °C, atmospheric pressure), and it is preferably solid. The thermosetting resin may be used alone or in combination of two or more.

[0026] The thermosetting resin preferably contains an epoxy resin. Specifically, as the epoxy resin, a novolac epoxy resin obtained by epoxidizing a novolac resin obtained by condensing or co-condensing at least one phenolic compound selected from the group consisting of phenolic compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, etc. and naphthol compounds such as α-naphthol, β-naphthol, dihydroxynaphthalene, etc. with an aliphatic aldehyde compound such as formaldehyde, acetaldehyde, propionaldehyde, etc. under an acidic catalyst (phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, etc.); a triphenylmethane type epoxy resin obtained by epoxidizing a triphenylmethane type phenol resin obtained by condensing or co-condensing the above phenolic compound with an aromatic aldehyde compound such as benzaldehyde, salicylaldehyde, etc. under an acidic catalyst; a copolymer type epoxy resin obtained by epoxidizing a novolac resin obtained by co-condensing the above phenolic compound and naphthol compound with an aldehyde compound under an acidic catalyst; a diphenylmethane type epoxy resin which is a diglycidyl ether such as bisphenol A, bisphenol F, etc.; a biphenyl type epoxy resin which is a diglycidyl ether of an alkyl-substituted or unsubstituted biphenol; a stilbene type epoxy resin which is a diglycidyl ether of a stilbene-based phenolic compound; a sulfur atom-containing type epoxy resin which is a diglycidyl ether such as bisphenol S, etc.; an epoxy resin which is a glycidyl ether of alcohols such as butanediol, polyethylene glycol, polypropylene glycol, etc.; a glycidyl ester type epoxy resin which is a glycidyl ester of a polyvalent carboxylic acid compound such as phthalic acid, isophthalic acid, tetrahydrophthalic acid, etc.; a glycidylamine type epoxy resin in which active hydrogen bonded to a nitrogen atom such as aniline, diaminodiphenylmethane, isocyanuric acid, etc. is substituted with a glycidyl group; a dicyclopentadiene type epoxy resin obtained by epoxidizing a co-condensation resin of dicyclopentadiene and a phenolic compound;Vinylcyclohexene diepoxide, which is obtained by epoxidizing the olefin bond in the molecule; 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate; 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane and other alicyclic epoxy resins; Paraxylylene-modified epoxy resin, which is the glycidyl ether of paraxylylene-modified phenol resin; Meta-xylylene-modified epoxy resin, which is the glycidyl ether of meta-xylylene-modified phenol resin; Terpene-modified epoxy resin, which is the glycidyl ether of terpene-modified phenol resin; Dicyclopentadiene-modified epoxy resin, which is the glycidyl ether of dicyclopentadiene-modified phenol resin; Cyclopentadiene-modified epoxy resin, which is the glycidyl ether of cyclopentadiene-modified phenol resin; Polycyclic aromatic ring-modified epoxy resin, which is the glycidyl ether of polycyclic aromatic ring-modified phenol resin; Naphthalene-type epoxy resin, which is the glycidyl ether of naphthalene ring-containing phenol resin; Halogenated phenol novolac-type epoxy resin; Hydroquinone-type epoxy resin; Trimethylolpropane-type epoxy resin; Linear aliphatic epoxy resin obtained by oxidizing the olefin bond with a peracid such as peracetic acid; Aralkyl-type epoxy resin obtained by epoxidizing aralkyl-type phenol resins such as phenol aralkyl resin and naphthol aralkyl resin; and the like. Furthermore, epoxy compounds of silicone resins, epoxy compounds of acrylic resins, etc. are also mentioned as epoxy resins. The epoxy resin may be used alone or in combination of two or more.;

[0027] Among the above epoxy resins, the triphenylmethane type epoxy resin is not particularly limited as long as it is an epoxy resin made from a compound having a triphenylmethane skeleton as a raw material. For example, an epoxy resin obtained by glycidyl etherifying a triphenylmethane type phenol resin such as a novolak type phenol resin of a compound having a triphenylmethane skeleton and a compound having a phenolic hydroxyl group is preferable, and an epoxy resin represented by the following general formula (VIII) is more preferable. Among the epoxy resins represented by the following general formula (VIII), 1032H60 (Mitsubishi Chemical Corporation, trade name), EPPN-501HY, EPPN-502H (Nippon Kayaku Co., Ltd., trade name), etc. in which i is 0 and k is 0 are available as commercial products.

[0028]

Chemical formula

[0029] In formula (VIII), R 17 and R 18 represent monovalent organic groups having 1 to 18 carbon atoms, and all of them may be the same or different. i represents an integer of 0 to 3 independently, and k represents an integer of 0 to 4 independently. n is an average value and represents a number of 0 to 10.

[0030] Among the above epoxy resins, the biphenyl type epoxy resin is not particularly limited as long as it is an epoxy resin having a biphenyl skeleton. For example, an epoxy resin represented by the following general formula (II) is preferable. Among the epoxy resins represented by the following general formula (II), when the positions where oxygen atoms are substituted among R 8 are the 4- and 4'-positions, the 3,3',5,5'-positions are methyl groups, and the other R 8 are hydrogen atoms, YX-4000 and YX-4000H (Mitsubishi Chemical Corporation, trade names), when all of R 8 are hydrogen atoms, 4,4'-bis(2,3-epoxypropoxy)biphenyl, when all of R 8 are hydrogen atoms, and when the positions where oxygen atoms are substituted among R 8 are the 4- and 4'-positions, the 3,3',5,5'-positions are methyl groups and the others are R8 YL-6121H (manufactured by Mitsubishi Chemical Corporation, trade name), which is a mixture when R

[0031]

Chemical formula

[0032] In formula (II), R 8 represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aromatic group having 4 to 18 carbon atoms, and all of them may be the same or different. n is an average value and represents a number from 0 to 10.

[0033] Since the biphenyl-type epoxy resin has a low melt viscosity, for example, when a thermosetting resin composition is used as a sealing material, even if a high filling of an inorganic filler is used for the purpose of improving the reflow resistance, it is less likely to cause a wire sweep problem in a semiconductor package. For this reason, in recent years, biphenyl-type epoxy resins have been preferably used as sealing materials for surface-mounted packages. Although the biphenyl-type epoxy resin has a low melt viscosity near 180°C, since its softening point is relatively high, high-temperature kneading is desirable in order to sufficiently disperse the resin by kneading. According to the production method of the present disclosure, since the primary kneading is performed at 100°C or higher, even when the thermosetting resin contains a biphenyl-type epoxy resin, it tends to be possible to preferably knead the resin component and the inorganic filler while suppressing an increase in viscosity.

[0034] Among the above epoxy resins, the aralkyl-type epoxy resin is not particularly limited as long as it is an epoxy resin using a phenolic resin synthesized from at least one selected from the group consisting of phenolic compounds such as phenol and cresol and naphthol compounds such as naphthol and dimethylnaphthol, and dimethoxyparaxylene, bis(methoxymethyl)biphenyl or derivatives thereof as raw materials. For example, an epoxy resin obtained by glycidyl etherifying a phenolic resin synthesized from at least one selected from the group consisting of phenolic compounds such as phenol and cresol and naphthol compounds such as naphthol and dimethylnaphthol, and dimethoxyparaxylene, bis(methoxymethyl)biphenyl or derivatives thereof is preferred, and an epoxy resin represented by the following general formula (X) or (XI) is more preferred.

[0035] Among the epoxy resins represented by the following general formula (X), when i is 0 and R 38 is a hydrogen atom, NC-3000 (product name, manufactured by Nippon Kayaku Co., Ltd.), and when i is 0 and R 38 is a hydrogen atom, a mixture of an epoxy resin and an epoxy resin in which all R in the general formula (II) 8 are hydrogen atoms in a mass ratio of 80:20, such as CER-3000 (product name, manufactured by Nippon Kayaku Co., Ltd.), is commercially available. Also, among the epoxy resins represented by the following general formula (XI), ESN-175 (product name, manufactured by Nippon Steel Chemical & Material Co., Ltd.), in which l is 0, j is 0, and k is 0, is commercially available.

[0036]

Chemical formula

[0037] In formulas (X) and (XI), R 38 represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and they may all be the same or different from each other. R 37 , R 39 ~R 41represents a monovalent organic group having 1 to 18 carbon atoms, and all of them may be the same or different. i is an integer from 0 to 3 independently, j is an integer from 0 to 2 independently, k is an integer from 0 to 4 independently, and l represents an integer from 0 to 4 independently. n is an average value and is a number from 0 to 10 independently.

[0038] The epoxy equivalent weight (molecular weight / number of epoxy groups) of the epoxy resin is not particularly limited. From the perspective of the balance of various properties such as moldability, reflow resistance, and electrical reliability, it is preferably 100 g / eq to 1000 g / eq, and more preferably 150 g / eq to 500 g / eq. The epoxy equivalent weight of the epoxy resin is the value measured by the method according to JIS K 7236:2009.

[0039] When the epoxy resin is solid at 25°C, the melting point or softening point of the epoxy resin is not particularly limited. From the perspective of blocking resistance, the melting point or softening point of the epoxy resin is preferably 40°C or higher, and more preferably 50°C or higher. From the perspective of suppressing thickening by kneading, the melting point or softening point of the epoxy resin is preferably 150°C or lower, more preferably 140°C or lower, and even more preferably 130°C or lower. Among them, for the purpose of meeting the requirements such as high thermal conductivity and reflow resistance in recent years, even when using an epoxy resin with a melting point or softening point of 90°C or higher, 100°C or higher, 110°C or higher, or 120°C or higher (for example, a highly crystalline resin with a melting point of 90°C or higher, 100°C or higher, 110°C or higher, or 120°C or higher), the production method of the present disclosure can be preferably used. The melting point of the epoxy resin is the value measured by differential scanning calorimetry (DSC), and the softening point of the epoxy resin is the value measured by the method (ring and ball method) according to JIS K 7234:1986.

[0040] When the thermosetting resin composition contains an epoxy resin, the content of the epoxy resin is preferably 0.5% by mass to 50% by mass, more preferably 2% by mass to 30% by mass, and even more preferably 2% by mass to 20% by mass based on the total mass of the thermosetting resin composition from the viewpoints of strength, fluidity, heat resistance, moldability, etc.

[0041] The thermosetting resin composition may further contain a curing agent. The type of the curing agent is not particularly limited as long as it is a compound that causes a curing reaction with the thermosetting resin used in combination. The curing agent itself may be a thermosetting resin.

[0042] For example, examples of the curing agent used in combination with the epoxy resin include phenolic curing agents, amine curing agents, acid anhydride curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, blocked isocyanate curing agents, and the like. The curing agent may be used alone or in combination of two or more. From the viewpoint of improving heat resistance, the phenolic curing agent is preferable as the curing agent. The curing agent may be solid or liquid under normal temperature and pressure (for example, 25°C, atmospheric pressure), and it is preferably solid.

[0043] A phenolic curing agent is a compound having a phenolic hydroxyl group in the molecule (hereinafter also referred to as a phenolic resin). Specific examples of the phenolic resin include polyhydric phenol compounds such as resorcinol, catechol, bisphenol A, bisphenol F, substituted or unsubstituted biphenol; phenolic compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, aminophenol, and at least one phenolic compound selected from the group consisting of naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene, and aldehyde compounds such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde, which are condensed or co-condensed under an acidic catalyst to obtain a novolak-type phenolic resin; an aralkyl-type phenolic resin such as a phenolic aralkyl resin or a naphthol aralkyl resin synthesized from the above phenolic compound and dimethoxyparaxylene, bis(methoxymethyl)biphenyl, etc.; a p-xylylene and / or m-xylylene-modified phenolic resin; a melamine-modified phenolic resin; a terpene-modified phenolic resin; a dicyclopentadiene-type phenolic resin and a dicyclopentadiene-type naphthol resin synthesized by copolymerization from the above phenolic compound and dicyclopentadiene; a cyclopentadiene-modified phenolic resin; a polycyclic aromatic ring-modified phenolic resin; a biphenyl-type phenolic resin; a triphenylmethane-type phenolic resin obtained by condensing or co-condensing the above phenolic compound and an aromatic aldehyde compound such as benzaldehyde and salicylaldehyde under an acidic catalyst; and a phenolic resin obtained by copolymerizing two or more of these. The phenolic resin may be used alone or in combination of two or more.

[0044] The hydroxyl equivalent of the phenolic resin is not particularly limited. From the viewpoint of the balance of various properties such as moldability, reflow resistance, and electrical reliability, the hydroxyl equivalent of the phenolic resin is preferably 70 g / eq to 1000 g / eq, more preferably 80 g / eq to 500 g / eq.

[0045] The hydroxyl equivalent of the phenolic resin refers to the value calculated based on the hydroxyl value measured in accordance with JIS K0070:1992.

[0046] When the phenolic resin is solid, its softening point or melting point is not particularly limited. From the viewpoints of moldability and reflow resistance when using the thermosetting resin composition for encapsulation applications, the softening point or melting point of the phenolic resin is preferably 40°C to 180°C, and more preferably 50°C to 130°C from the viewpoint of handleability during the production of the thermosetting resin composition.

[0047] The melting point or softening point of the phenolic resin shall be the value measured in the same manner as the melting point or softening point of the epoxy resin.

[0048] When the thermosetting resin composition contains a phenolic resin, the content of the phenolic resin is preferably 0.5% by mass to 50% by mass, more preferably 2% by mass to 30% by mass, and even more preferably 2% by mass to 20% by mass based on the total mass of the thermosetting resin composition.

[0049] The equivalent ratio of the epoxy resin to the curing agent, that is, the ratio of the number of functional groups in the curing agent to the number of epoxy groups in the epoxy resin (number of functional groups in the curing agent / number of epoxy groups in the epoxy resin) is not particularly limited. From the perspective of reducing the unreacted components, the equivalent ratio of the epoxy resin to the curing agent (number of functional groups in the curing agent / number of epoxy groups in the epoxy resin) is preferably set in the range of 0.5 to 2.0, and more preferably set in the range of 0.6 to 1.3. From the viewpoint of moldability when using the thermosetting resin composition for encapsulation applications, the equivalent ratio of the epoxy resin to the curing agent (number of functional groups in the curing agent / number of epoxy groups in the epoxy resin) is even more preferably set in the range of 0.8 to 1.2. The number of functional groups of the curing agent refers to, for example, the number of hydroxyl groups in the phenolic curing agent when using a phenolic curing agent as the curing agent, and the number of active hydrogens in the amine curing agent when using an amine curing agent as the curing agent.

[0050] <Curing accelerator>The type of the curing accelerator is not particularly limited, and includes diazabicycloalkenes such as 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) and 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), cyclic amidine compounds such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 2-heptadecylimidazole; derivatives of the cyclic amidine compounds; phenol novolak salts of the cyclic amidine compounds or their derivatives; compounds having intramolecular polarization formed by adding compounds having a π bond, such as quinone compounds such as maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone, and diazophenylmethane; cyclic amidinium compounds such as tetraphenylborate salts of DBU, tetraphenylborate salts of DBN, tetraphenylborate salts of 2-ethyl-4-methylimidazole, and tetraphenylborate salts of N-methylmorpholine; tertiary amine compounds such as pyridine, triethylamine, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; derivatives of the tertiary amine compounds; ammonium salt compounds such as tetra-n-butylammonium acetate, tetra-n-butylammonium phosphate, tetraethylammonium acetate, tetra-n-hexylammonium benzoate, and tetrapropylammonium hydroxide;Organic phosphines such as primary phosphines like ethylphosphine and phenylphosphine, secondary phosphines like dimethylphosphine and diphenylphosphine, and tertiary phosphines like triphenylphosphine, diphenyl(p-tolyl)phosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, tris(alkylalkoxyphenyl)phosphine, tris(dialkylphenyl)phosphine, tris(trialkylphenyl)phosphine, tris(tetraalkylphenyl)phosphine, tris(dialkoxyphenyl)phosphine, tris(trialkoxyphenyl)phosphine, tris(tetraalkoxyphenyl)phosphine, trialkylphosphine, dialkylarylphosphine, alkyldiarylphosphine, trinaphthylphosphine, tris(benzyl)phosphine, etc.; phosphine compounds such as complexes of the above organic phosphines and organic borons; compounds having intramolecular polarization formed by adding a compound having a π bond such as maleic anhydride, 1,4-benzoquinone, 2,5-xylenequinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone, anthraquinone, etc. to the above organic phosphine or the above phosphine compound; compounds having intramolecular polarization obtained by reacting the above organic phosphine or the above phosphine compound with a halogenated phenol compound such as 4-bromophenol, 3-bromophenol, 2-bromophenol, 4-chlorophenol, 3-chlorophenol, 2-chlorophenol, 4-iodophenol, 3-iodophenol, 2-iodophenol, 4-bromo-2-methylphenol, 4-bromo-3-methylphenol, 4-bromo-2,6-dimethylphenol, 4-bromo-3,5-dimethylphenol, 4-bromo-2,6-di-t-butylphenol, 4-chloro-1-naphthol, 1-bromo-2-naphthol, 6-bromo-2-naphthol, 4-bromo-4'-hydroxybiphenyl and then undergoing a dehydrohalogenation step;Tetra-substituted phosphonium compounds such as tetraphenylphosphonium, tetra-phenylborate salts of tetra-substituted phosphonium such as tetraphenylphosphonium tetrakis(p-tolyl)borate, salts of tetra-substituted phosphonium and phenolic compounds, etc.; phosphobetaine compounds; adducts of phosphonium compounds and silane compounds, etc. are mentioned. The curing accelerator may be used alone or in combination of two or more.

[0051] For example, when an epoxy resin is used as the thermosetting resin, particularly preferred curing accelerators include triphenylphosphine, adducts of triphenylphosphine and quinone compounds, etc.

[0052] The content of the curing accelerator is preferably 0.1 part by mass to 30 parts by mass, more preferably 1 part by mass to 15 parts by mass, based on 100 parts by mass of the resin component (that is, the thermosetting resin (including the curing agent when the curing agent is a thermosetting resin)). When the amount of the curing accelerator is 0.1 part by mass or more based on 100 parts by mass of the resin component, it tends to cure well in a short time. When the amount of the curing accelerator is 30 parts by mass or less based on 100 parts by mass of the resin component, the curing rate is not too fast and a good molded product tends to be obtained.

[0053] <Inorganic filler> The material of the inorganic filler is not particularly limited. Specifically, as the material of the inorganic filler, inorganic materials such as fused silica, crystalline silica, glass, alumina, calcium carbonate, zirconium silicate, calcium silicate, silicon nitride, aluminum nitride, boron nitride, magnesium oxide, silicon carbide, beryllia, zirconia, zircon, forsterite, steatite, spinel, mullite, titania, talc, clay, mica, etc. are mentioned. An inorganic filler having a flame retardant effect may be used. Examples of the inorganic filler having a flame retardant effect include composite metal hydroxides such as aluminum hydroxide, magnesium hydroxide, composite hydroxide of magnesium and zinc, zinc borate, etc. Among the inorganic fillers, silica such as fused silica is preferred from the viewpoint of reducing the linear expansion coefficient, and alumina is preferred from the viewpoint of high thermal conductivity.

[0054] The shape of the inorganic filler is not particularly limited, and spherical shape is preferable from the viewpoints of filling property and mold wear property.

[0055] The inorganic filler may be used alone or in combination of two or more. Note that "using two or more inorganic fillers in combination" includes, for example, cases where two or more inorganic fillers having the same component but different average particle diameters are used, cases where two or more inorganic fillers having the same average particle diameter but different components are used, and cases where two or more inorganic fillers having different average particle diameters and types are used.

[0056] The content rate of the inorganic filler is not particularly limited. From the viewpoint of further improving the properties such as the thermal expansion coefficient, thermal conductivity, and elastic modulus of the cured product, the content rate of the inorganic filler is preferably 30% by volume or more, more preferably 40% by volume or more, still more preferably 50% by volume or more, particularly preferably 60% by volume or more, and extremely preferably 70% by volume or more of the whole thermosetting resin composition. From the viewpoints of improving fluidity, reducing viscosity, etc., the content rate of the inorganic filler is preferably 99% by volume or less, preferably 98% by volume or less, and more preferably 97% by volume or less of the whole thermosetting resin composition. Also, for example, when the thermosetting resin composition is used for compression molding, the content rate of the inorganic filler may be 70% by volume to 99% by volume, may be 80% by volume to 99% by volume, may be 83% by volume to 99% by volume, or may be 85% by volume to 99% by volume of the whole thermosetting resin composition.

[0057] The content rate of the inorganic filler in the cured product of the thermosetting resin composition can be measured as follows. First, measure the total mass of the cured product, bake the cured product at 400 °C for 2 hours and then at 700 °C for 3 hours to evaporate the resin component, and measure the mass of the remaining inorganic filler. Calculate the volume from each obtained mass and respective specific gravity, obtain the ratio of the volume of the inorganic filler to the total volume of the cured product, and use it as the content rate of the inorganic filler.

[0058] Compared with the conventional method, according to the manufacturing method of the present disclosure, the fluidity during kneading and molding of the mixture of each component tends to be maintained low. Therefore, even in a composition in which the content of the inorganic filler could not be increased due to the influence of the increase in viscosity according to the conventional method, it is considered that the inorganic filler can be highly filled according to the manufacturing method of the present disclosure.

[0059] When the inorganic filler is particulate, its average particle size is not particularly limited. For example, the volume average particle size of the entire inorganic filler is preferably 80 μm or less, and may be 50 μm or less, 40 μm or less, 30 μm or less, or 20 μm or less. Also, the volume average particle size of the entire inorganic filler is preferably 0.1 μm or more, more preferably 0.2 μm or more, and even more preferably 0.3 μm or more. When the volume average particle size of the inorganic filler is 0.1 μm or more, the increase in the viscosity of the thermosetting resin composition tends to be more suppressed. When the volume average particle size of the inorganic filler is 80 μm or less, the filling property into narrow gaps tends to be more improved. The volume average particle size of the inorganic filler can be measured as the particle size (D50) at which the cumulative from the smaller diameter side becomes 50% in the volume-based particle size distribution measured by a laser scattering diffraction method particle size distribution measuring device.

[0060] The smaller the particle size of the inorganic filler, the higher the viscosity of the mixture of each component tends to be. Even in a composition in which the content of the inorganic filler with a small particle size could not be increased due to the influence of the increase in viscosity according to the conventional method, it is considered that the content of the inorganic filler with a small particle size can be increased according to the manufacturing method of the present disclosure.

[0061] <Coupling agent> When the thermosetting resin composition contains an inorganic filler, a coupling agent may be included to enhance the adhesion between the resin component and the inorganic filler. Examples of the coupling agent include known coupling agents such as silane-based compounds, titanium-based compounds, aluminum chelate compounds, and aluminum / zirconium-based compounds.

[0062] Examples of the silane compounds include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, octenyltrimethoxysilane, glycidoxyoctyltrimethoxysilane, and methacryloxyoctyltrimethoxysilane.

[0063] Examples of the titanium compounds include isopropyltriisostearoyl titanate, isopropyltris(dioctylpyrophosphate) titanate, isopropyltri(N-aminoethyl-aminoethyl) titanate, tetraoctylbis(ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(ditridecyl phosphite) titanate, bis(dioctylpyrophosphate)oxyacetate titanate, bis(dioctylpyrophosphate)ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropylisostearoyldiacryl titanate, isopropyltri(dioctyl phosphate) titanate, isopropyltricumylphenyl titanate, and tetraisopropylbis(dioctyl phosphite) titanate.

[0064] When the thermosetting resin composition contains a coupling agent, the amount of the coupling agent is preferably 0.05 parts by mass to 20 parts by mass, more preferably 0.1 parts by mass to 15 parts by mass, based on 100 parts by mass of the inorganic filler. When the amount of the coupling agent is 0.05 parts by mass or more based on 100 parts by mass of the inorganic filler, the adhesiveness to the metal member tends to be further improved. When the amount of the coupling agent is 20 parts by mass or less based on 100 parts by mass of the inorganic filler, the moldability tends to be improved.

[0065] <Additive> In addition to the above components, the thermosetting resin composition may contain various additives such as an ion exchanger, a release agent, a flame retardant, a colorant, and a stress reliever. The thermosetting resin composition may contain various additives generally used in the art as needed in addition to the additives exemplified below.

[0066] (Ion exchanger) The thermosetting resin composition may contain an ion exchanger. In particular, when the thermosetting resin composition is used as a molding material for encapsulation, it is preferable to contain an ion exchanger from the viewpoint of improving the moisture resistance and high-temperature storage characteristics of an electronic component device including the element to be encapsulated. The ion exchanger is not particularly limited, and conventionally known ones can be used. Specifically, hydrotalcite compounds, and hydrated oxides of at least one element selected from the group consisting of magnesium, aluminum, titanium, zirconium, and bismuth can be mentioned. The ion exchanger may be used alone or in combination of two or more. Among them, hydrotalcite represented by the following general formula (A) is preferable.

[0067] Mg (1-X) Al X (OH)2(CO3) X / 2 ·mH2O ……(A) (0 < X ≦ 0.5, m is a positive number)

[0068] When the thermosetting resin composition contains an ion exchanger, its content is not particularly limited as long as it is an amount sufficient to capture ions such as halogen ions. For example, it is preferably 0.1 part by mass to 30 parts by mass, more preferably 1 part by mass to 10 parts by mass, based on 100 parts by mass of the resin component.

[0069] (Release agent) From the viewpoint of obtaining good mold release properties with the mold during molding, the thermosetting resin composition may contain a release agent. The release agent is not particularly limited, and conventionally known ones can be used. Specifically, examples include higher fatty acids such as carnauba wax, montanic acid, and stearic acid, metal salts of higher fatty acids, ester waxes such as montanic acid esters, and polyolefin waxes such as oxidized polyethylene and non-oxidized polyethylene. The release agent may be used alone or in combination of two or more.

[0070] When the thermosetting resin composition contains a release agent, its amount is preferably 0.01 part by mass to 10 parts by mass, more preferably 0.1 part by mass to 5 parts by mass, based on 100 parts by mass of the resin component. When the amount of the release agent is 0.01 part by mass or more based on 100 parts by mass of the resin component, mold release properties tend to be sufficiently obtained. When it is 10 parts by mass or less, better adhesion and curability tend to be obtained.

[0071] (Flame retardant) The thermosetting resin composition may contain a flame retardant. The flame retardant is not particularly limited, and conventionally known ones can be used. Specifically, examples include organic or inorganic compounds containing a halogen atom, antimony atom, nitrogen atom, or phosphorus atom, and metal hydroxides. The flame retardant may be used alone or in combination of two or more.

[0072] When the thermosetting resin composition contains a flame retardant, its amount is not particularly limited as long as it is an amount sufficient to obtain the desired flame retardant effect. For example, it is preferably 1 part by mass to 30 parts by mass, more preferably 2 parts by mass to 20 parts by mass, based on 100 parts by mass of the resin component.

[0073] (Colorant) The thermosetting resin composition may further contain a colorant. Examples of the colorant include known colorants such as carbon black, organic dyes, organic pigments, titanium oxide, red lead, and red iron oxide. The content of the colorant can be appropriately selected according to the purpose and the like. The colorant may be used alone or in combination of two or more.

[0074] (Stress Relaxant) The thermosetting resin composition may contain a stress relaxant such as silicone oil and silicone rubber particles. By containing a stress relaxant, it is possible to reduce warping deformation of the package and the occurrence of package cracks when the thermosetting resin composition is used as a sealing material. Examples of the stress relaxant include generally used known stress relaxants (plasticizers). Specifically, thermoplastic elastomers such as silicone-based, styrene-based, olefin-based, urethane-based, polyester-based, polyether-based, polyamide-based, and polybutadiene-based, rubber particles such as NR (natural rubber), NBR (acrylonitrile-butadiene rubber), acrylic rubber, urethane rubber, and silicone powder, and rubber particles having a core-shell structure such as methyl methacrylate-styrene-butadiene copolymer (MBS), methyl methacrylate-silicone copolymer, and methyl methacrylate-butyl acrylate copolymer. The stress relaxant may be used alone or in combination of two or more.

[0075] ≪Thermosetting Resin Composition≫ The thermosetting resin composition of the present disclosure is obtained by the above-described production method of the present disclosure. The thermosetting resin composition may be solid or liquid at normal temperature and pressure (for example, 25°C, atmospheric pressure), and it is preferably solid. The shape of the thermosetting resin composition when it is solid is not particularly limited, and examples include powdery, granular, and tablet-like. From the viewpoint of handleability, the dimensions and mass of the thermosetting resin composition when it is tablet-like are preferably such that they match the molding conditions of the package.

[0076] [Viscosity of Thermosetting Resin Composition] The viscosity of the thermosetting resin composition is not particularly limited. It is preferably adjusted to a desired viscosity according to the molding method, the composition of the thermosetting resin composition, etc. When the thermosetting resin composition is used for encapsulation, it is preferably adjusted according to the ease of wire flow during molding. For example, when the thermosetting resin composition is used for encapsulation, from the viewpoint of reducing wire flow, etc., the viscosity of the thermosetting resin composition is preferably 200 Pa·s or less at 175 °C, more preferably 150 Pa·s or less, even more preferably 100 Pa·s or less, particularly preferably 50 Pa·s or less, and extremely preferably 30 Pa·s or less. The lower limit value of the viscosity of the thermosetting resin composition is not particularly limited, and for example, it may be 2 Pa·s or more at 175 °C. The viscosity of the thermosetting resin composition can be measured by a high-temperature type flow tester (for example, manufactured by Shimadzu Corporation).

[0077] [Flowability of Thermosetting Resin Composition] The flow distance of the spiral flow obtained by the following method is not particularly limited, and is preferably 70 cm or more, more preferably 100 cm or more, even more preferably 150 cm or more, and even more preferably 200 cm or more. Using a mold for measuring spiral flow according to EMMI-1-66, the thermosetting resin composition is molded to obtain the flow distance. The molding is carried out by a transfer molding machine under the conditions of a mold temperature of 180 °C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds.

[0078] The distance of the disk flow obtained by the following test is not particularly limited, and is preferably 80 mm or more, more preferably 90 mm or more, and even more preferably 100 mm or more. Using a flat die for disk flow measurement having an upper die of 200 mm (W) × 200 mm (D) × 25 mm (H) and a lower die of 200 mm (W) × 200 mm (D) × 15 mm (H), 5 g of a thermosetting resin composition weighed with an upper pan balance is placed at the center of the lower die heated to 180°C. After 5 seconds, the upper die heated to 175°C is closed, and compression molding is carried out under the conditions of a load of 78 N and a curing time of 90 seconds. The major diameter (mm) and minor diameter (mm) of the molded product are measured with a vernier caliper, and the average value (mm) is defined as the disk flow.

[0079] 〔Gel time〕 From the viewpoint of fluidity, the gel time is preferably 20 seconds or more, more preferably 30 seconds or more, and even more preferably 40 seconds or more. From the viewpoint of curability, the gel time is preferably 120 seconds or less, more preferably 100 seconds or less, and even more preferably 90 seconds or less. The gel time is defined as the value measured by the following method. For 3 g of the thermosetting resin composition, measurement using a cure rheometer (for example, manufactured by JSR Trading Co., Ltd.) is carried out at a temperature of 175°C, and the time until the rise of the torque curve is defined as the gel time.

[0080] 〔Flexural strength of cured product〕 The flexural strength of the cured product of the thermosetting resin composition at room temperature (25°C) measured by the following method is preferably 100 MPa or more, more preferably 110 MPa or more, even more preferably 120 MPa or more, and particularly preferably 125 MPa or more. The cured product of the thermosetting resin composition is cut out into a rectangular parallelepiped of 2.0 mm × 5.0 mm × 40 mm to produce a test piece for flexural strength evaluation. Using this test piece, a flexural test is carried out with a tensile universal material testing machine (for example, Instron 5948, Instron Corporation) under the conditions of a support span of 32 mm and a crosshead speed of 1 mm / min. Using the measured results, a flexure stress-displacement curve is created from formula (A), and the maximum stress is defined as the flexural strength.

[0081] σ = 3FL / 2bh 2 ··· Formula (A)

[0082] σ: Bending stress (MPa) F: Bending load (N) L: Span distance (mm) b: Specimen width (mm) h: Specimen thickness (mm)

[0083] The flexural strength of the thermosetting resin composition at 260°C measured by the above method is preferably 10 MPa or more, more preferably 12 MPa or more, and even more preferably 14 MPa or more.

[0084] 〔Use of the thermosetting resin composition〕 The use of the thermosetting resin composition of the present disclosure is not particularly limited, and for example, it can be used in various mounting techniques as a sealing material for electronic component devices. Further, the thermosetting resin composition of the present disclosure can be used in various applications where it is desirable for the resin composition to have good fluidity and curability, such as resin molded bodies for various modules, resin molded bodies for motors, resin molded bodies for in-vehicle use, and sealing materials for protective materials for electronic circuits.

[0085] ≪Electronic component device≫ The electronic component device of the present disclosure includes an element encapsulated with the thermosetting resin composition obtained by the above-described production method of the present disclosure.

[0086] Examples of the electronic component device include those in which an element part obtained by mounting an element (active elements such as semiconductor chips, transistors, diodes, thyristors, etc., passive elements such as capacitors, resistors, coils, etc.) on a support member such as a lead frame, a wired tape carrier, a wiring board, glass, a silicon wafer, an organic substrate, etc. is encapsulated with the thermosetting resin composition. More specifically, DIP (Dual Inline Package), PLCC (Plastic Leaded Chip Carrier), QFP (Quad Flat Package), SOP (Small Outline Package), SOJ (Small Outline J-lead package), TSOP (Thin Small Outline Package), TQFP (Thin Quad Flat Package), LQFP (Low Profile Quad Flat Package), etc., which have a structure in which elements are fixed on a lead frame and the terminal portions and lead portions of the elements such as bonding pads are connected by wire bonding, bumps, etc., and then encapsulated by transfer molding or the like using a thermosetting resin composition; TCP (Tape Carrier Package) which has a structure in which elements connected to a tape carrier with bumps are encapsulated with a thermosetting resin composition; COB (Chip On Board) modules, hybrid ICs, multi-chip modules, etc., which have a structure in which elements connected to wiring formed on a support member by wire bonding, flip chip bonding, solder, etc. are encapsulated with a thermosetting resin composition; BGA (Ball Grid Array), CSP (Chip Size Package), MCP (Multi Chip Package), etc., which have a structure in which elements are mounted on the surface of a support member having terminals for connecting to a wiring board formed on the back surface, and the elements are connected to the wiring formed on the support member by bumps or wire bonding, and then the elements are encapsulated with a thermosetting resin composition. Also, the thermosetting resin composition can be suitably used in printed wiring boards.

[0087] Examples of methods for encapsulating an electronic component device using a thermosetting resin composition include a low-pressure transfer molding method, an injection molding method, a compression molding method, etc.

[0088] When the thermosetting resin composition obtained by the production method of the present disclosure is used as an encapsulant for an element, it is preferable that the occurrence of voids, blisters, flow marks, etc. is suppressed in the obtained package. Voids, blisters, and flow marks can be evaluated as follows. The target encapsulant can be transfer molded, and the presence or absence of blister generation can be confirmed by observing the surface of the obtained package. In addition, flow marks can be confirmed by observing particularly directly above the chip mounting location. Furthermore, voids can be confirmed by observing the inside of the package with an SAT (scanning acoustic tomograph) image. The molding conditions are, for example, mold temperature: 175°C, molding pressure: about 7 MPa, and curing time: 120 seconds. Also, the SAT image can be observed, for example, by the method described in the following resin-rich evaluation method.

[0089] When the thermosetting resin composition obtained by the production method of the present disclosure is used as an encapsulant for an element, it is preferable that the resin-richness after molding is suppressed. Resin-richness is a phenomenon that appears when the target encapsulant is compression molded. Although the reason is not clear, it is considered that this resin-rich region is caused by, for example, the defoaming of gas dissolved in the encapsulant due to decompression during compression molding, resulting in a locally reduced amount of inorganic filler at the defoamed location. For example, in an encapsulant with low fluidity, even if a region with a locally reduced amount of inorganic filler occurs, it is difficult for the inorganic filler to flow into that region by fluidity. Therefore, it is considered that the region where the amount of inorganic filler is locally reduced hardens as it is, resulting in a resin-rich region. Resin-richness can be confirmed as follows using an SAT image. First, the encapsulant to be measured is molded using a compression molding apparatus and observed by SAT (for example, Hitachi Power Solutions Co., Ltd., model number: FS200 III A) to obtain a SAT image. As the compression molding conditions, for example, the mold temperature is 175 degrees, the molding pressure is about 10 MPa, and the curing time is 120 seconds. The SAT observation condition is a probe frequency of 50 MHz. From the obtained SAT image, the black dot portions are selectively polished cross-sectionally, and it is possible to determine whether the black dot portions are resin-rich using elemental analysis.

[0090] When the thermosetting resin composition obtained by the production method of the present disclosure is used as an encapsulant for an element, it is preferable that the remaining resin on the mold used for molding and the surface agglomeration failure of the obtained package are suppressed. The presence or absence of the remaining resin on the mold and the surface agglomeration failure of the package can be confirmed by the following method. The target encapsulant is molded by transfer molding, and so-called continuous molding is carried out, which is continuously repeated. For example, during several hundred shots, molding is continuously carried out without cleaning the mold, and the presence or absence of the remaining resin in the mold and the occurrence of surface agglomeration failure of the package are confirmed. The molded package is not particularly limited, but SOP or the like can be simply selected. The molding conditions are also not particularly limited, but for example, the mold temperature is 175 °C, the molding pressure is about 7 MPa, and the curing time is 120 seconds.

[0091] When the thermosetting resin composition obtained by the manufacturing method of the present disclosure is used as an encapsulant for an element, it is preferable that cracks are suppressed in the resulting package. The presence or absence of package cracks can be evaluated, for example, by transfer molding the target encapsulant and performing a temperature cycle test or the like on the resulting package. For example, the resulting package is moisture absorbed under the conditions of MSL (Moisture Sensitivity Level) condition: Level 3 (30°C or less, 60% RH, 168 hours), reflow treated under the conditions of 260°C x 30 sec x 3 times, and further subjected to a temperature cycle of -65°C / 150°C. After 700 temperature cycles, it is confirmed whether cracks have occurred in the package. There is no particular limit to the target package, but an example is an LQFP. The molding conditions are, for example, a mold temperature of 175°C, a molding pressure of about 7 MPa, and a curing time of 120 seconds. EXAMPLES

[0092] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0093] <Preparation of Thermosetting Resin Composition> First, the following components were prepared.

[0094] (thermosetting resin) Epoxy resin 1: EPPN-501HY (product name, Nippon Kayaku Co., Ltd., triphenylmethane type epoxy resin with epoxy equivalent of 163g / eq to 175g / eq and softening point of 57℃ to 63℃) Epoxy resin 2: jER YX-4000H (product name, Mitsubishi Chemical Corporation, biphenyl type epoxy resin with epoxy equivalent of 180g / eq to 192g / eq and melting point of 105°C) Epoxy resin 3: NC-3000 (product name, Nippon Kayaku Co., Ltd., aralkyl type epoxy resin with epoxy equivalent of 265g / eq to 285g / eq and softening point of 53℃ to 63℃)

[0095] · Hardener 1: H-4 (trade name, Meiwafosis Co., Ltd., phenolic novolak type phenolic resin with a hydroxyl equivalent of 103 g / eq, softening point 85°C)

[0096] (Inorganic filler) · Inorganic filler 1: Spherical silica with a volume average particle diameter (D50) of 15 μm · Inorganic filler 2: Spherical silica with a volume average particle diameter (D50) of 0.5 μm

[0097] (Coupling agent) · Coupling agent: N-phenyl-3-aminopropyltrimethoxysilane

[0098] (Curing accelerator) · Curing accelerator: Phosphorus-based curing accelerator

[0099] (Other additives) · Release agent: Hextawax (Hoechst AG) · Colorant: Carbon black

[0100] The thermosetting resin compositions of Examples 1 to 3 were prepared by the following method (referred to as "Production Method A"). As the kneading apparatus, a twin-screw kneader (kneading extruder) schematically shown in FIG. 1 was used. The main material inlet is connected to the first kneading section, and the side feeder is connected to the second kneading section downstream in the extrusion direction. First, among the components shown in Table 1, the components other than the curing accelerator were thoroughly mixed with a mixer. The mixture was charged from the main material inlet of the twin-screw kneader, and the curing accelerator was charged from the side feeder, followed by kneading and extrusion. The primary kneading temperature in the first kneading section was set to about 150°C. In the second kneading section, a mechanism was provided to gradually lower the temperature from the side feeder connection part to the outlet so that it was about 70°C near the side feeder connection part and about 30°C near the outlet of the twin-screw kneader. Then, the melt was cooled, and the solidified product was pulverized into a powder to prepare a powdery thermosetting resin composition.

[0101] The thermosetting resin compositions of Comparative Examples 1 to 6 were prepared by the following method (referred to as "Production Method B"). After thoroughly mixing each component shown in Table 1 with a mixer, melt-kneading was performed at about 150 °C using a twin-screw kneader. Thereafter, the melt was cooled, and the solidified material was pulverized into powder to prepare a powdery thermosetting resin composition.

[0102] <Evaluation of Thermosetting Resin Composition> The prepared thermosetting resin composition was evaluated by various tests shown below. The evaluation results are shown in Table 1. In addition, unless otherwise specified, the thermosetting resin composition was molded using a transfer molding machine under the conditions of a mold temperature of 180 °C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds. Further, post-curing was performed at 175 °C for 6 hours as necessary.

[0103] 〔Spiral Flow〕 Using a mold for measuring spiral flow according to EMMI-1-66, the thermosetting resin composition was molded under the above conditions, and the flow distance (cm) was determined.

[0104] 〔Melt Viscosity〕 Using a Koka-type flow tester (manufactured by Shimadzu Corporation), the minimum melt viscosity of the thermosetting resin composition at 175 °C was measured.

[0105] 〔Gel Time〕 Measurement was performed at a temperature of 175 °C using a Curemeter of JSR Trading Co., Ltd. with respect to 3 g of the thermosetting resin composition, and the time until the torque curve started to rise was defined as the gel time (seconds).

[0106] 〔Bending Strength〕 The thermosetting resin composition was molded under the above conditions and post-cured. The cured product was cut out into a rectangular parallelepiped of 2.0 mm × 5.0 mm × 40 mm to prepare a test piece for evaluating bending strength. Using this test piece, a bending test was performed with a Tensilon universal material testing machine (Instron 5948, Instron Corporation) under the conditions of a distance between supports of 32 mm and a crosshead speed of 1 mm / min. Using the measured results, a bending stress-displacement curve was created from Equation (A), and the maximum stress was defined as the bending strength. The measurement was performed at room temperature and 260 °C, respectively.

[0107] σ = 3FL / 2bh 2 ··· Equation (A)

[0108] σ: Bending stress (MPa) F: Bending load (N) L: Span distance (mm) b: Specimen width (mm) h: Specimen thickness (mm)

[0109] 〔Disk flow〕 Using a flat die for disk flow measurement having an upper die of 200 mm (W) × 200 mm (D) × 25 mm (H) and a lower die of 200 mm (W) × 200 mm (D) × 15 mm (H), 5 g of the thermosetting resin composition weighed with an upper pan balance is placed at the center of the lower die heated to 175°C. After 5 seconds, the upper die heated to 180°C is closed, and compression molding is performed under the conditions of a load of 78 N and a curing time of 90 seconds. The major diameter (mm) and minor diameter (mm) of the molded product are measured with a caliper, and the average value (mm) is taken as the disk flow.

[0110] 〔Package evaluation〕 (Evaluation of voids, blisters, and flow marks) The evaluation of voids, blisters, and flow marks was performed by the method described above. The transfer molding conditions were a mold temperature of 175°C, a molding pressure of about 7 MPa, and a curing time of 120 seconds. The SAT observation was performed under the same conditions as the following evaluation of resin-rich.

[0111] (Evaluation of resin-rich) The evaluation of resin-rich was performed by the method described above. The compression molding conditions were a mold temperature of 175 degrees, a molding pressure of 10 MPa, and a curing time of 120 seconds. The SAT observation was performed using Hitachi Power Solutions Co., Ltd., model number: FS200 III A, under the condition of a probe frequency of 50 MHz.

[0112] (Evaluation of remaining mold resin and package surface agglomeration failure) The evaluation of mold resin residue and package surface agglomeration destruction was carried out by the method described above. The package was SOP, and the molding conditions were mold temperature: 175 °C, molding pressure: about 7 MPa, and curing time: 120 seconds.

[0113] (Evaluation of Package Cracks) The evaluation of package cracks was carried out by the method described above. The package was LQFP, and the molding conditions were mold temperature: 175 °C, molding pressure: 7 MPa, and curing time: 120 seconds.

[0114] [Table 1]

[0115] In Table 1, "-" in the component compounding amount indicates that the corresponding component is not compounded.

[0116] Note that the onset temperatures of the compositions of Examples 1 to 3 are higher than 70 °C.

[0117] As can be seen from the above results, the thermosetting resin composition obtained by Production Method A has the same degree of good fluidity as the thermosetting resin compositions obtained by Production Method B (Comparative Examples 1 to 3) with the same composition and the thermosetting resin compositions obtained by Production Method B by blending an inorganic filler that had been surface-treated in advance with the same epoxy resin (Comparative Examples 4 to 6), and was excellent in flexural strength at normal temperature and 260 °C when formed into a cured product. In addition, in the semiconductor package sealed using the thermosetting resin composition obtained by Production Method A, molding defects were suppressed. In particular, since voids, flow marks, and resin-rich sites were suppressed, it is presumed that the thermosetting resin composition has good fluidity. Further, since blisters, mold resin residue, package agglomeration destruction, and package cracks were suppressed, it is presumed that the thermosetting resin composition has good curability.

Explanation of Symbols

[0118] 1 Main Material Inlet 2 Side feeder 10 Kneading extruder A First kneading section B Second kneading section

Claims

1. A primary kneading step of kneading a mixture of a thermosetting resin, an inorganic filler, a coupling agent, and a release agent at 100°C or higher, a secondary kneading step of adding a curing accelerator after the primary kneading and further kneading, A method for producing a thermosetting resin composition, comprising: The method for producing a thermosetting resin composition, wherein the content of the inorganic filler with respect to the total amount of the thermosetting resin composition is 50% by volume or more.

2. The production method according to claim 1, wherein the temperature of the secondary kneading is lower than the temperature of the primary kneading.

3. The production method according to claim 1 or 2, wherein the temperature of the secondary kneading is lower than the onset temperature measured by differential scanning calorimetry of the mixture after adding the curing accelerator.

4. The production method according to any one of claims 1 to 3, wherein the onset temperature measured by differential scanning calorimetry of the mixture after adding the curing accelerator is lower than 120°C.

5. The production method according to any one of claims 1 to 4, wherein the volume average particle diameter of the inorganic filler is 20 μm or less.

6. The primary kneading and the secondary kneading are performed using a kneading extruder, and in the secondary kneading, the thermosetting resin composition is gradually cooled toward the extrusion direction. The production method according to any one of claims 1 to 5.

7. The production method according to claim 6, wherein the outlet temperature of the kneading extruder after the secondary kneading is 30°C or lower.

8. The production method according to any one of claims 1 to 7, wherein the release agent is not added in the secondary kneading.

9. A thermosetting resin composition obtained by the production method according to any one of claims 1 to 8.

10. An electronic component device including an element sealed with the thermosetting resin composition obtained by the production method according to any one of claims 1 to 8.

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