JP6706818B2 - Semiconductor device - Google Patents

Description

The present invention relates to a semiconductor device. More specifically, the present invention relates to a semiconductor device that can be suitably used as a component forming an electronic device or the like.

A semiconductor device in which a semiconductor is mounted on a substrate is used in various applications as a component of electronic equipment. As a die attach material for such a semiconductor device, replacement of lead solder has become remarkable in recent years. However, in a Si power device, a light emitting diode, etc., a high temperature is emitted from a die in order to handle a large current, and thus high temperature lead solder and a conductive adhesive have been used.
Next-generation power semiconductors such as SiC and GaN are expected to operate at higher temperatures than Si power semiconductors. For automotive applications, it is required to operate at 250°C for a long time for the purpose of simplifying the cooling mechanism of the power semiconductor itself, but if the temperature exceeds 200°C, the lead-free solder itself may melt or undergo oxidative deterioration. In addition, since the organic adhesive component of the conductive adhesive is also thermally decomposed, the sinter bonding of the metal component is regarded as a promising technique for die attachment.

As a material containing a metal component that can be used for die attach, a conductive paste or die attach containing silver particles having a predetermined average particle size and a lower alcohol and containing no adhesive component is disclosed (Patent Document 1, Non-Patent Documents 1 and 2). Also disclosed is a conductive material obtained by firing a composition for a conductive material containing silver particles having a predetermined average particle diameter, an inorganic material having a smaller linear expansion coefficient than silver, and a metal oxide at a predetermined temperature, It is described that this material can be used for die attach (see Patent Document 2).
On the other hand, as a resin composition used as a sealing material for semiconductors, a cyanate ester-based composition containing a cyanate ester compound and a silane compound having a specific structure is disclosed (see Patent Document 3).

Patent No. 5207281 Patent No. 5417861 JP, 2014-15603, A

K. 5 people from Suganuma, Macroelectronics Reliablity, 52, (2012), 375-380 Soichi Sakamoto outside 2 people, Journal of Materials Science: Materials in Electronics, (2013), 24, 1332-1340.

As described above, it has been studied to use silver sinter bonding as a semiconductor die attach material which is supposed to be used at a temperature higher than 200° C. However, silver is used for a long time in a high temperature environment higher than 200° C. When placed, the sintering progresses and the morphology changes, which may increase the elasticity of the layer portion of the die attach material between the substrate and the semiconductor element, increase the stress, or reduce the adhesive strength. There is a possibility that it will not function as a semiconductor. In addition, since metal such as silver originally has a poor affinity with organic resin, when a known epoxy resin is used to seal a semiconductor using a metal component as a die attach, peeling occurs at the interface between the sealant and the metal. Is likely to occur. Therefore, it has been extremely difficult to guarantee the environmental reliability of the power device itself for a long period of time.

The present invention has been made in view of the above circumstances, and even when used at a high temperature exceeding 200° C. for a long period of time, the occurrence of peeling in a semiconductor device is sufficiently suppressed, and the present invention can function as a semiconductor. It is an object to provide a semiconductor device.

The present inventor has conducted various studies on a semiconductor device capable of sufficiently suppressing the occurrence of peeling even when used at a high temperature exceeding 200° C. for a long period of time and functioning as a semiconductor. As a result, the metal particles are different from the metal particles. By using a conductive composition to which an inorganic component is added as a die attach material, it is possible to increase the elasticity of the layer portion of the die attach material between the substrate and the semiconductor element even when used at a high temperature exceeding 200° C. for a long period of time. When the resin composition containing a cyanate ester compound and/or a maleimide compound is used for sealing a semiconductor element using such a die attach material, the stress exceeds 200°C. It was found that the occurrence of peeling between the metal particles and the encapsulant was suppressed even when used at high temperatures, and a semiconductor device capable of functioning as a semiconductor was obtained, and it was conceived that the above problems can be solved satisfactorily. However, the present invention has been reached.

That is, the present invention is a semiconductor device including a substrate and a semiconductor element, wherein the semiconductor device comprises metal particles, and a component derived from a conductive composition containing an inorganic component different from the metal particles. , A component derived from a resin composition containing a cyanate ester compound and/or a maleimide compound.
The present invention is described in detail below.
It should be noted that a combination of two or more of the individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

1. Semiconductor Device The semiconductor device of the present invention contains a substrate and a semiconductor element, metal particles, and a component derived from a conductive composition containing an inorganic component different from the metal particles, and a cyanate ester compound and/or a maleimide compound. It is characterized in that it contains a component derived from a resin composition. The component derived from the conductive composition means a component formed from the conductive composition, and may be the same component as the conductive composition or may be a component modified from the conductive composition. .. The same applies to components derived from a resin composition containing a cyanate ester compound and/or a maleimide compound. In the semiconductor device of the present invention, a conductive composition containing metal particles and an inorganic component different from the metal particles is used as a die attach material, and a resin composition containing a cyanate ester compound and/or a maleimide compound is a semiconductor. Since it is used for sealing the element, the component derived from the conductive composition is present between the substrate of the semiconductor device and the semiconductor element, and the component derived from the resin composition is the component derived from the conductive composition. It exists so as to cover the substrate and the semiconductor element sandwiched therebetween.
The semiconductor device of the present invention comprises a substrate and a semiconductor element, metal particles, and a conductive composition containing an inorganic component different from the metal particles, and a resin composition containing a cyanate ester compound and/or a maleimide compound. Although it is manufactured using the above materials, other materials may be used as long as the materials are manufactured using these materials. In addition, the substrate, the semiconductor element, the conductive composition, and the resin composition may each be used alone or in combination of two or more.
Hereinafter, the conductive composition, the resin composition, the semiconductor element and the substrate used in the semiconductor device of the present invention will be described in order.

<Conductive composition>
The conductive composition in the present invention is characterized by containing metal particles and an inorganic component different from the metal particles, and such a conductive composition is also one aspect of the present invention.
When the metal particles are sintered and joined as the die attach material for bonding the substrate and the semiconductor element, if the silver particles are left to stand at a temperature of 200° C. or higher, the silver particles are fused with each other and the bonded portion becomes large. As a result, the shape of the die attach material changes and becomes highly elastic, or stress is generated in the semiconductor device. On the other hand, when a conductive composition containing an inorganic component different from the metal particles is used in addition to the metal particles, the action of the inorganic component different from the metal particles prevents the progress of fusion between the metal particles. As a result, the dense structure of the sintered joint between the metal particles is easily maintained, and the shape change of the die attach material is suppressed. Further, when a semiconductor device using a metal die attach material is left in a high temperature state of 200° C. or higher for a long time, the adhesive force between the substrate and the semiconductor element may be reduced. The cause of such a decrease in the adhesive force is that the fusion of metal particles progresses and the bonded portion becomes larger, and along with that, the components such as copper originally present on the substrate are metal particles to each other. It is considered that it is easy to move to the semiconductor element side along the coupling part of. By the action of the inorganic component different from the metal particles, the progress of fusion between the metal particles is hindered, and when the dense structure of the sintered joint between the metal particles is easily maintained, the movement of copper and the like is also reduced. It is also possible to suppress a decrease in the adhesive force between the substrate and the semiconductor element.

As the metal particles contained in the conductive composition of the present invention, one kind or two kinds or more of particles of silver, copper, nickel, zinc or the like can be used.
Among these, silver or copper is preferable in terms of conductivity and heat dissipation. More preferably, it is silver. Since silver atoms have the property of causing a surface reaction of moving on the surface while reacting with oxygen in an environment of 250 to 300° C., the progress of the sintering reaction is suppressed by adding an inorganic component. The action will be more effectively exhibited when the metal atom is a silver atom.
The metal particles may be a compound of a metal or a simple substance of metal, but are preferably particles of a simple substance of metal.

The metal particles contained in the conductive composition of the present invention preferably have an average particle diameter (median diameter) of 0.1 to 15 μm. The thickness is more preferably 0.1 to 10 μm, still more preferably 0.3 to 6 μm. By including the metal particles having such an average particle diameter, the conductive composition becomes more suitable as a die attach material.
In the present invention, the average particle size (median size) of metal particles can be measured by a laser diffraction method.

The conductive composition of the present invention may contain one type of metal particles or two or more types of metal particles, but contains two or more types of metal particles having different average particle diameters (median diameters). It is preferable that it is toxic.
When two or more kinds of metal particles having different average particle diameters are contained, it is preferable that the proportion of the metal particles having an average particle diameter of 0.1 to 15 μm is 70% by mass or more. It is more preferably 80% by mass or more, further preferably 90% by mass or more, and particularly preferably 100% by mass, that is, the case of containing two or more kinds of metal particles having different average particle diameters (median diameters). That is, metal particles having an average particle diameter (median diameter) in the range of 0.1 to 15 μm are used in combination.
Such two or more kinds of metal particles having different average particle diameters (median diameters) may be particles of the same metal species or particles of different metal species, but have the same conductive composition. It is one of the preferable modes of the present invention to include two or more kinds of metal particles having different average particle diameters (median diameters).

When the conductive composition of the present invention contains two or more kinds of metal particles each having an average particle diameter (median diameter) in the range of 0.1 to 15 μm, the average particle diameter of the metal particles having the largest average particle diameter. Is preferably 1.0 to 9.9 μm. The average particle size of the metal particles having the smallest average particle size is preferably 0.1 to 0.99 μm. That is, the conductive composition contains metal particles having an average particle diameter of 1.0 to 9.9 μm in median diameter and metal particles having an average particle diameter of 0.1 to 0.99 μm in median diameter. Is one of the preferred embodiments of the present invention.
The average particle size of the metal particles having the largest average particle size is more preferably 1.2 to 8 μm, further preferably 1.4 to 5 μm, and particularly preferably 1.6 to 4 μm, Especially preferably, it is 1.8 to 3.5 μm, and most preferably 2.0 to 3.2 μm.
The average particle size of the metal particles having the smallest average particle size is more preferably 0.1 to 0.9 μm, still more preferably 0.15 to 0.8 μm, and particularly preferably 0.1. 2 to 0.7 μm, particularly preferably 0.25 to 0.6 μm, and most preferably 0.3 to 0.5 μm.

When the conductive composition of the present invention contains two or more kinds of metal particles having different average particle diameters (median diameters), the mass ratio of the metal particles having the largest average particle diameter and the metal particles having the smallest average particle diameter is: It is preferably 30/70 to 85/15. It is more preferably 40/60 to 80/20, still more preferably 50/50 to 70/30.

The metal particles contained in the conductive composition of the present invention preferably have a BET specific surface area measured by the BET method of 0.5 to 10 m ² /g. It is more preferably 0.6 to 8.0 m ² /g, still more preferably 0.6 to 6.0 m ² /g.

The shape of the metal particles contained in the conductive composition of the present invention is not particularly limited, and may be any shape such as spherical, flat, or polyhedral, and includes two or more different shapes of metal particles. It may be. When the conductive composition of the present invention contains two or more kinds of metal particles having different average particle sizes, the shape of the metal particles may be the same or different.

The conductive composition of the present invention contains an inorganic component different from the above metal particles. The inorganic component different from the metal particles may be a compound or a simple substance of atoms.
The inorganic component contains at least one element belonging to Groups 1 to 17 of the periodic table excluding carbon (C) and the metal element contained in the metal particles contained in the conductive composition, and contains two or more of these elements. You may stay. Further, the element may be a metal element or a non-metal element.
The metal element contained in the metal particles contained in the conductive composition and the element of the periodic table groups 1 to 17 excluding carbon (C) are preferably elements of the periodic table groups 3 to 16, and more preferably, It is an element of Groups 4 to 15 of the periodic table.

When the inorganic component is a compound, the compound is an oxide; a nitride; a complex oxide; a layered double hydroxide; a hydroxide; a clay compound; a solid solution; an alloy; a zeolite; a halide; a carboxylate compound; a carbonate compound. Hydrogen carbonate compound; Nitric acid compound; Sulfate compound; Sulfonic acid compound; Phosphoric acid compound such as hydroxyapatite; Phosphorous compound; Hypophosphorous acid compound, Boric acid compound; Silicic acid compound; Aluminic acid compound; Sulfide; Onium compound A salt and the like can be mentioned. It is preferably any of oxides, nitrides and sulfides, and more preferably any of oxides and nitrides.

The inorganic component different from the above-mentioned metal particles in the conductive composition of the present invention is preferably in the form of particles, and its average particle size (median size) is preferably 0.05 to 50 μm. .. The thickness is more preferably 0.08 to 20 μm, and further preferably 0.1 to 10 μm.
In the present invention, the average particle size (median size) of the inorganic component different from the above metal particles can be measured by a laser diffraction method.

The content ratio of the inorganic component different from the metal particles in the conductive composition of the present invention is preferably 0.5 to 50 mass% with respect to 100 mass% of the entire conductive composition. It is more preferably 0.8 to 40% by mass, and even more preferably 1.0 to 30% by mass.

The conductive composition of the present invention may contain a solvent. The solvent is not particularly limited, and a non-polar aromatic compound such as an alcohol having 1 to 20 carbon atoms which may have a substituent, benzene, xylene, toluene, naphthalene, (di)methylnaphthalene; C5 to about 12 Hydrocarbon compounds up to acetone; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone; ethyl acetate, butyl acetate, ethyl butyrate, butyl butyrate, ethyl lactate, butyl lactate, propylene glycol methyl ether acetate, γ- Esters such as butyrolactone; ethers such as diethyl ether, dibutyl ether, tetrahydrofuran, monoglyme, diglyme, triglyme, and the like. Of these, alcohols having 1 to 20 carbon atoms that may have a substituent are most preferable.

Regarding the alcohol having 1 to 20 carbon atoms which may have a substituent, the alcohol having 1 to 20 carbon atoms preferably has 1 to 3 hydroxyl groups. The alcohol having 1 to 20 carbon atoms preferably has a linear or branched alkyl group having 1 to 10 carbon atoms, and when the alcohol having 1 to 20 carbon atoms has a substituent, it has 1 carbon atom. Those in which a hydrogen atom of a linear or branched alkyl group of 10 is substituted with a substituent are preferable.
Examples of the alcohol having 1 to 20 carbon atoms having no substituent include methanol, ethanol, ethylene glycol, n-propanol, i-propanol, triethylene glycol, n-butanol, i-butanol, sec-butanol, t-butanol. , N-pentanol, i-pentanol, sec-pentanol, t-pentanol, 2-methylbutanol, n-hexanol, 1-methylpentanol, 2-methylpentanol, 3-methylpentanol, 4- Examples include methylpentanol, 1-ethylbutanol, 2-ethylbutanol, 1,1-dimethylbutanol, 2,2-dimethylbutanol, 3,3-dimethylbutanol, and 1-ethyl-1-methylpropanol.

The substituent that the alcohol having 1 to 20 carbon atoms may have is preferably at least one selected from the group consisting of an alkoxy group, an amino group and a halogen atom. The alkoxy group preferably has 1 to 10 carbon atoms. Halogen atoms include fluorine, bromine, chlorine and iodine.
Examples of the C1-C20 alcohol having a substituent include methoxymethanol, 2-methoxyethanol, 2-ethoxyethanol, 2-chloroethanol, ethanolamine and the like.
The conductive composition of the present invention may contain one type of solvent or may contain two or more types of solvents.

When the conductive composition of the present invention contains a solvent, the mixing ratio (mass ratio) of the metal particles and the solvent is not particularly limited, but the metal particles:solvent is preferably 4:1 to 16:1. .. When the metal particles are contained in such a ratio, the composition can exhibit better performance as a die attach material. The metal particle:solvent ratio is more preferably 6:1 to 12:1, further preferably 8:1 to 10:1.

When the conductive composition of the present invention is used as a die attach material, the metal particles are melted and fused to the substrate and the semiconductor element, whereby the substrate and the semiconductor element are fixed. Therefore, the conductive composition of the present invention does not require an adhesive component to fix the semiconductor element to the substrate.
Therefore, in the conductive composition of the present invention, the content ratio of the adhesive component is preferably 15% by mass or less with respect to the entire conductive composition. The content ratio of the adhesive component is more preferably 10% by mass or less, further preferably 5% by mass or less, and particularly preferably 3% by mass or less. When the content ratio of the adhesive component is 3% by mass or less, it can be said that the adhesive component is not substantially contained. However, when such an adhesive component is used as the organic component contained in the conductive composition of the present invention described above, the preferable content ratio of the adhesive component is the same as the content ratio of the inorganic component different from the metal particles described above. Is preferred.
Here, the adhesive component means an organic compound having an action of adhering different substances, and a compound known as an epoxy-based, phenol-based, acrylic-based, polyimide-based, silicon-based, urethane-based or thermoplastic-based adhesive. Etc. are included.

The conductive composition of the present invention may contain other components than the above-mentioned various components.
Examples of other components include coupling agents.
The content ratio of these other components is preferably 10% by mass or less based on 100% by mass of the entire conductive composition. It is more preferably 8% by mass or less, and further preferably 5% by mass or less.

<Resin composition containing cyanate ester compound and/or maleimide compound>
The resin composition containing the cyanate ester compound and/or the maleimide compound in the present invention contains either or both of the cyanate ester compound and the maleimide compound. The cyanate ester compound and the maleimide compound contained in the resin composition may be one type each or two or more types.
Below, a cyanate ester compound and a maleimide compound are demonstrated in order, and the other component which a resin composition may contain after that is demonstrated.
[Cyanate ester compound]
The cyanate ester compound contained in the resin composition of the present invention has at least two cyanato groups (—OCN) in one molecule, and for example, a compound represented by the following general formula (1) is preferable. is there.

(In the general formula (1), ^{R 1} and ^{R 2} are the same or different, a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a halogenated alkyl group, or, .R ³ represents a halogen group (X) Are the same or different and represent any of the organic groups represented by the following chemical formulas, R ⁴ are the same or different and represent the organic groups represented by the following chemical formulas, and m ¹ is 0 or 1. . N ¹ represents an integer of 0 to 10.)

The compound represented by the general formula (1) is not particularly limited, but for example, bis(4-cyanatophenyl)methane, bis(3,5-dimethyl-4-cyanatophenyl)methane, bis(3-) Methyl-4-cyanatophenyl)methane, bis(4-cyanatophenyl)-1,1-ethane, bis(4-cyanatophenyl)-2,2-ethane, 2,2-bis(4-cyanato) Phenyl)propane, 2,2-bis(3,5-dimethyl-4-cyanatophenyl)methane, di(4-cyanatophenyl)ether, di(4-cyanatophenyl)thioether, 4,4-{1 ,3-Phenylenebis(1-methylethylidene)}bisphenylcyanato, 4,4-dicyanatophenyl, 2,2-bis(4-cyanatophenyl)-1,1,1,3,3,3- Hexafluoropropane, 1,1'-bis-(p-cyanatophenyl)-ethane, 2,2'-bis(p-cyanatophenyl)propane, 4,4'-methylenebis(2,6-dimethylphenyloxy) Cyanate ester of dihydric phenol such as anato), 2,2′-bis(p-cyanatophenyl)hexafluoropropane, α,α′-bis(4-cyanatophenyl)-m-diisopropylbenzene; Tris( Cyanate ester of trihydric phenol such as 4-cyanatephenyl)-1,1,1-ethane and bis(3,5-dimethyl-4-cyanatephenyl)-4-cyanatephenyl-1,1,1-ethane; Examples thereof include phenol novolac type cyanate ester, cresol novolac type cyanate ester, and dicyclopentadiene bisphenol type cyanate ester. Among these, 2,2-bis(4-cyanatophenyl)propane and phenol novolac-type cyanate ester are preferable from the viewpoint of the dielectric properties and curability of the cured product.

As the cyanate ester compound, a multimer (for example, trimer or pentamer) formed by cyclizing a cyanato group of the compound represented by the general formula (1) to form a triazine ring structure is used. You can also do it. Of these, trimers are preferable from the viewpoint of operability and solubility in other curable resins. A method for obtaining a multimer may be a usual method.

The cyanate ester compound may be liquid or solid, but in view of melt-kneading with other curable resin, it has high compatibility or has a melting point or softening point of 120° C. or lower. Is preferred. More preferably, it has a melting point or a softening point of 100° C. or lower.
The melting point means a temperature (° C.) in a state where crystals are melted into a liquid in an inert atmosphere. Therefore, amorphous compounds and those that are already liquid at room temperature have no melting point.
The melting point of the cyanate ester compound can be measured by, for example, differential scanning calorimetry (DSC). The softening point (°C) is a value measured according to JIS K7234 (1986), and can be measured using, for example, a thermosoftening temperature measuring device (product name "ASP-MG4", manufactured by Meitec Co., Ltd.). it can.

When the resin composition in the present invention contains a cyanate ester compound, the mixing ratio of the cyanate ester compound is preferably 5 to 95 mass% with respect to 100 mass% of the total mass of the organic components contained in the resin composition. .. With such a blending ratio, both durability against heat and humidity and handleability as a semiconductor encapsulating material can be compatible, and excellent reliability can be given to a semiconductor package using the same. It is more preferably 10 to 90% by mass, and even more preferably 15 to 85% by mass.

[Maleimide compound]
When the resin composition in the present invention contains a maleimide compound, the handling property of the resin composition is improved.
Examples of the maleimide compound include bismaleimide, for example, N,N'-ethylene bismaleimide, N,N'-hexamethylene bismaleimide, N,N'-m-phenylene bismaleimide, N,N'-p-phenylene bismaleimide. , 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, bis[4-(4-maleimidophenoxy)phenyl]methane, 1,1,1,3,3,3-hexafluoro-2, 2-bis[4-(4-maleimidophenoxy)phenyl]propane, N,N'-p,p'-diphenyldimethylsilyl bismaleimide, N,N'-4,4'-diphenylether bismaleimide, N,N' -Methylenebis(3-chloro-p-phenylene)bismaleimide, N,N'-4,4'-diphenylsulfone bismaleimide, N,N'-4,4'-dicyclohexylmethane bismaleimide, N,N'-di Methylenecyclohexane bismaleimide, N,N'-m-xylene bismaleimide, N,N'-4,4'-diphenylcyclohexane bismaleimide, N-phenylmaleimide and aldehyde compounds such as formaldehyde, acetaldehyde, benzaldehyde and hydroxyphenylaldehyde Co-condensates of are preferred. In addition, the following general formula (2):

(In the formula, R ⁵ is

Or

Represents a divalent group consisting of Q ¹ is a group directly connected to two aromatic rings, and is a divalent hydrocarbon group having 1 to 10 carbon atoms, a hexafluorinated isopropylidene group, a carbonyl group, a thio group, a sulfinyl group, a sulfonyl group and an oxide. It represents at least one group selected from the group consisting of groups. The bismaleimide compound represented by the formula (1) is suitable.
Specifically, 1,3-bis(3-maleimidophenoxy)benzene, bis[4-(3-maleimidophenoxy)phenyl]methane, 1,1-bis[4-(3-maleimidophenoxy)phenyl]ethane, 1,2-[4-(3-maleimidophenoxy)phenyl]ethane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]propane, 2,2-bis[4-(3-maleimidophenoxy)phenyl] ] Butane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4-bis(3-maleimidophenoxy)biphenyl, bis [4-(3-maleimidophenoxy)phenyl]ketone, bis[4-(3-maleimidophenoxy)phenyl]sulfide, bis[4-(3-maleimidophenoxy)phenyl]sulfoxide, bis[4-(3-maleimidophenoxy)phenyl] )Phenyl]sulfone, bis[4-(3-maleimidophenoxy)phenyl]ether, the following general formula (3):

(In the formula, Q ² represents a divalent group consisting of an aromatic ring which may have a substituent. n ² represents the number of repetitions and is an average of 0 to 10.). Compounds and the like are suitable. As the above Q ² , specifically, a divalent group such as a phenyl group, a biphenyl group, a naphthyl group (a phenylene group, a biphenylene group, a naphthylidene group, etc.) is preferable.

When the maleimide compound in the present invention is a polymer compound, the weight average molecular weight of the maleimide compound is preferably 200 to 5000. When the molecular weight of the maleimide compound is in such a range, a cured product having excellent heat resistance and the like can be obtained. It is more preferably 220 to 4500, and even more preferably 250 to 4000.
The weight average molecular weight of the maleimide compound can be measured by GPC under the conditions described in the examples.

When the resin composition in the present invention contains a maleimide compound, the content ratio thereof is preferably 10 to 90% by mass relative to 100% by mass of the total mass of the organic components contained in the resin composition. It is more preferably 15 to 85% by mass, and further preferably 20 to 80% by mass.

The resin composition in the present invention preferably contains both a cyanate ester compound and a maleimide compound.
When the resin composition in the present invention contains a cyanate ester compound and a maleimide compound, the blending ratio of the maleimide compound is 5 to 500 mass% with respect to 100 mass% of the cyanate ester compound in the curable resin composition. Is preferred. By using such a ratio, the resin composition can have excellent heat resistance and can be sufficiently improved in handling property. It is more preferably 5 to 400% by mass, further preferably 5 to 300% by mass, relative to 100% by mass of the cyanate ester compound.

[Siloxane compound]
The resin composition in the present invention further has the following average composition formula (4):
XaYbZcSiOd (4)
(In the formula, X is the same or different and represents an organic skeleton containing an imide bond. Y is the same or different and represents at least one selected from the group consisting of a hydrogen atom, a hydroxyl group, a halogen atom and an OR group. Z is the same or different and represents an organic group containing no imide bond, and R is the same or different and is at least 1 selected from the group consisting of an alkyl group, an acyl group, an aryl group and an unsaturated aliphatic residue. Represents a species and may have a substituent, a, b and c are 0 or a number less than 3 and d is a number less than 2 which is not 0 and a+b+c+2d=4). It is preferable to contain a siloxane compound.
By containing such a siloxane compound, the resin composition becomes more excellent in heat resistance.

In the siloxane compound, the structure of the siloxane skeleton (main chain skeleton that essentially requires a siloxane bond) is preferably, for example, chain (linear or branched), ladder, net, ring, cage, cubic or the like. It is illustrated. Above all, the effect is likely to be exhibited even if the addition amount of the siloxane compound is small, and therefore, the ladder shape, the net shape, and the cage shape are preferable. That is, as the siloxane compound, a compound containing polysilsesquioxane is particularly preferable.
The ratio of the siloxane skeleton in the siloxane compound is preferably 10 to 80% by mass in 100% by mass of the siloxane compound. It is more preferably 15 to 70% by mass, and further preferably 20 to 50% by mass.

In the above average composition formula (4), the preferable form of X is as described later, and as Y, a hydroxyl group or an OR group is preferable. Among them, an OR group is more preferable, and an OR group in which R is an alkyl group having 1 to 8 carbon atoms is more preferable. Further, Z is preferably at least one selected from the group consisting of an aromatic residue such as an alkyl group, an aryl group and an aralkyl group, and an unsaturated aliphatic residue (these have a substituent. May be). More preferably, it is an alkyl group having 1 to 8 carbon atoms, which may have a substituent, or an aromatic residue such as an aryl group or an aralkyl group. The coefficient a of X is a number 0≦a<3, the coefficient b of Y is a number 0≦b<3, and the coefficient c of Z is a number 0≦c<3, The coefficient d of O is a number 0<d<2. The coefficient a of X is preferably a number 0<a<3. In other words, the coefficient a of X is preferably a number that is not 0 and is less than 3.

The siloxane compound is, for example, the following general formula (5):

(In the formula, X, Y, and Z are respectively the same as above. n ³ and n ⁴ represent the degree of polymerization. n ³ is a positive integer other than 0, and n ⁴ is 0 or a positive integer. It is an integer.)
In addition, "Y/Z-" represents that Y or Z is bonded, " _X1-2- " represents that one or two Xs are bonded, and "(Z/ Y) _1-2- " represents that one Z or Y is bonded, two Z or Y are bonded, or one each of Z and Y is bonded to a total of two. "Si-(X/Y/Z) ₃ "indicates that any three kinds selected from X, Y and Z are bonded to a silicon atom.
In the general formula (5), Si-Om ³ and Si-Om ⁴ is not intended to define the binding order of Si-Om ³ and Si-Om ^4, for example, Si-Om ³ and Si-Om ⁴ is A form in which they are co-condensed alternately or randomly, a form in which a polysiloxane of Si—Om ³ and a polysiloxane of Si—Om ⁴ are bonded, and the like are preferable, and the condensed structure is arbitrary.

The siloxane compound can be represented by the above average composition formula (4), but the siloxane skeleton (the main chain skeleton that essentially requires a siloxane bond) of the siloxane compound can also be represented by (SiO _m ) _n . The structure other than (SiO _m ) _n in such a siloxane compound is an organic skeleton having an imide bond (structure requiring an imide bond) X, Y such as a hydrogen atom or a hydroxyl group, and an organic group containing no imide bond. Z, which will be bonded to the silicon atom of the main chain skeleton.
X, Y and Z may or may not be contained in the repeating unit in the form of “chain”. For example, one or more X may be contained in one molecule as a side chain. In the above (SiO _m ) _n , n represents the degree of polymerization, and the degree of polymerization represents the degree of polymerization of the main chain skeleton, and n organic skeletons having an imide bond may not necessarily be present. In other words, the organic skeleton having one imide bond does not necessarily exist in one unit of (SiO _m ) _n . Further, one or more skeleton-containing organic skeletons may be contained in one molecule. However, when a plurality of skeletons are contained, one skeleton has two or more imide bond-containing organic skeletons as described above. May be combined. These are the same in the following.

In the main chain skeleton (SiO _m ) _n , m is preferably 1 or more and less than 2. More preferably, m=1.5 to 1.8.
The above n represents the degree of polymerization, and is preferably 1 to 5000. It is more preferably 1 to 2000, further preferably 1 to 1000, and particularly preferably 1 to 200.
The silane compound in the case where n is 2 has 2 structural units (hereinafter, also referred to as “structural unit (I)”) in which at least one organic skeleton (X) having an imide bond is bonded to a silicon atom. And a form in which only one structural unit (I) is included. Specifically, the following general formula (6):

(In the formula, A is Y or Z, and X, Y and Z are the same as described above.) and the like are preferable, and a form of a homopolymer containing two identical structural units (I), There are a homopolymer form containing two different constitutional units (I) and a copolymer form containing only one constitutional unit (I) (form of co-condensed structure).

In the above average composition formula (4), the proportion of the organic skeleton having an imide bond is preferably 20 to 100 mol with respect to 100 mol of silicon atoms contained in the silane compound. The amount is more preferably 50 to 100 mol, and further preferably 70 to 100 mol.

X in the average composition formula (4) is preferably a constitutional unit represented by the following general formula (7). That is, in the siloxane compound of the present invention, X in the average composition formula (4) is represented by the following general formula (7):

(In the formula, R ⁶ represents at least one structure selected from the group consisting of aromatic, heterocyclic and alicyclic. x and z are the same or different and each is an integer of 0 or more and 5 or less, and y Is 0 or 1.) It is preferable to include a siloxane compound, which is a structural unit represented by. By including such a siloxane compound having a ring structure in the structure, the heat resistance of the cured product obtained from the resin composition of the present invention is further improved.

In the structural unit represented by the general formula (7), x and z are the same or different and are integers of 0 or more and 5 or less. In addition, y is 0 or 1, and preferably 0. x+z may be an integer of 0 or more and 10 or less, but is preferably 3 to 7, more preferably 3 to 5, and particularly preferably 3.

Further, in the general formula (7), R ⁶ represents at least one structure selected from the group consisting of aromatic, heterocyclic and alicyclic rings. That is, R ⁶ is composed of a group having a ring structure (aromatic ring) of an aromatic compound, a group having a ring structure of a heterocyclic compound (heterocycle), and a group having a ring structure of an alicyclic compound (alicyclic) It represents at least one group selected from the group.
Specific examples of R ⁶ include a phenylene group, a naphthylidene group, a divalent group of norbornene, an (alkyl)cyclohexylene group, and a cyclohexenyl group.
The structural unit represented by the general formula (7) is a structural unit represented by the following general formula (7-1) when R ⁶ is a phenylene group, and R ⁶ is (alkyl)cyclohexylene. When it is a group, it becomes a constitutional unit represented by the following general formula (7-2), and when R ⁶ is a naphthylidene group, it becomes a constitutional unit represented by the following general formula (7-3), and R ⁶ Is a constitutional unit represented by the following general formula (7-4) when R is a norbornene divalent group, and is represented by the following general formula (7-5) when R ⁶ is a cyclohexenyl group. It is a structural unit.

In the general formulas (7-1) to (7-5), x, y and z are the same as x, y and z in the general formula (7), respectively.
In the general formula (7-1), R ^{7 to} R ¹⁰ are the same or different and each represents at least one structure selected from the group consisting of a hydrogen atom, an alkyl group, a halogen atom and an aromatic group. It is preferable that all of R ^{7 to} R ¹⁰ are hydrogen atoms.
In the general formula (7-2), R ^{11 to} R ¹⁴ and R ^{11 ′} to R ^14′ are the same or different and are at least one selected from the group consisting of a hydrogen atom, an alkyl group, a halogen atom and an aromatic group. Represents the structure of. As the ^R 11 ^{to R 14} and ^R 11' ^{to R 14',} forms all ^{R 12} or ^{R 13} are the remaining methyl group is a hydrogen atom, ^or, R 11 ^{to R 14} and ^R 11' ^{to R 14 It} is preferable that all ^′ are hydrogen atoms or all R ^{11 to} R ¹⁴ and R ^{11 ′ to} R ^{14 ′} are fluorine atoms. More preferably, R ¹² or R ¹³ is a methyl group and the rest are all hydrogen atoms.

In the general formula (7-3), R ^{15 to} R ²⁰ are the same or different and each represents at least one structure selected from the group consisting of a hydrogen atom, an alkyl group, a halogen atom and an aromatic group. As R ^{15 to} R ²⁰ , the form in which all are hydrogen atoms or the form in which all are fluorine atoms is preferable. More preferably, it is a form in which all are hydrogen atoms.
In the general formula (7-4), R ^{21 to} R ²⁶ are the same or different and each represents at least one structure selected from the group consisting of a hydrogen atom, an alkyl group, a halogen atom and an aromatic group. As R ^{21 to} R ²⁶ , a form in which all are hydrogen atoms, a form in which all are fluorine atoms, or a form in which all are chlorine atoms are preferable. More preferably, it is a form in which all are hydrogen atoms.
In the general formula (7-5), R ^{27 to} R ³⁰ , R ^27′ and R ^30′ are the same or different and are at least one selected from the group consisting of a hydrogen atom, an alkyl group, a halogen atom and an aromatic group. Represents the structure of. As the ^R 27 ^{to R 30, R 27 'and R 30',} it forms all are hydrogen atom, and all are a fluorine atom form or any form of embodiment all is a chlorine atom is preferable. More preferably, it is a form in which all are hydrogen atoms.

Among the general formulas (7-1) to (7-5), the general formula (7-4) or (7-5) is preferable. When a siloxane compound having a reactive carbon-carbon unsaturated bond in the side chain is used, the siloxane compound is prevented from floating on the surface of the cured product by reacting with a maleimide compound or the like during curing of the resin composition. The appearance of the cured product can be improved.

Among the structural units represented by the above general formula (7), the following general formula (7-6):

(In the formula, R ³¹ represents at least one structure selected from the group consisting of aromatic, heterocyclic and alicyclic.) It is preferable that the structural unit is represented by That is, the siloxane compound of the present invention preferably contains a siloxane compound in which X in the average composition formula (4) is a structural unit represented by the general formula (7-6). In addition, it is preferable that R ³¹ in the general formula (7-6) is the same as R ⁶ described in the general formula (7).

Particularly preferred forms of the siloxane compound are poly(γ-phthaloimidopropylsilsesquioxane) in which R ³¹ is a phenylene group; poly{γ-(hexahydro-4-methyl) in which R ³¹ is a methylcyclohexylene group. poly {.gamma. ^{R 31} is divalent norbornene ^(; phthalimido) propyl ^{silsesquioxane}; R 31} is naphthylidene group poly {.gamma. (1,8-naphthalimide) propyl silsesquioxane} 5-norbornene-2,3-imido)propylsilsesquioxane}; poly[(cis-4-cyclohexene-1,2-imido)propylsilsesquioxane] in which R ³¹ is a cyclohexenyl group.
The structures of these compounds can be identified by measuring ¹ H-NMR, ¹³ C-NMR and MALDI-TOF-MS.

The number average molecular weight of the siloxane compound is preferably 100 to 10,000. If the polymer compound exceeds 10,000, it may not be able to be sufficiently mixed with the cyanate ester compound or the maleimide compound. If it is less than 100, the heat resistance and the like may not be sufficient. It is more preferably 500 to 5,000, still more preferably 1,000 to 5,000. The weight average molecular weight is preferably 100 to 10,000. It is more preferably 500 to 5,000, still more preferably 1,000 to 5,000.
The molecular weight (number average molecular weight and weight average molecular weight) of the siloxane compound can be measured by GPC (gel permeation chromatography) measurement under the conditions described in Examples.

In the above resin composition, the siloxane compound is preferably blended with the resin composition containing the maleimide compound, and the blending ratio in that case is 30 to 350 mass% with respect to 100 mass% of the maleimide compound contained in the resin composition. % Is preferable. It is more preferably 35 to 350% by mass, and further preferably 40 to 300% by mass.

The method for obtaining the siloxane compound is not particularly limited, and examples thereof include the following production methods (I) and (II).
(I) An intermediate (comprising a siloxane compound) represented by an average composition formula X′aYbZcSiOd having an organic skeleton X′ having an amide bond corresponding to the organic skeleton X containing an imide bond in the siloxane compound, and a siloxane bond. A manufacturing method including the step of imidizing.
(II) The organic skeleton having an imide bond corresponding to the organic skeleton X containing an imide bond in the siloxane compound is hydrolyzed and condensed with an intermediate composed of a siloxane compound having a hydrolyzable group bonded to a silicon atom. A manufacturing method including the step of:

[Carbodiimide compound]
The resin composition of the present invention preferably further contains a carbodiimide compound. The carbodiimide compound has higher reactivity with water than the cyanate ester compound, and when blended in the resin composition containing the cyanate ester compound, it preferentially reacts with water to become a urea compound as represented by the following formula (8). As described above, since the carbodiimide compound consumes water in preference to the cyanate ester compound, by adding the carbodiimide compound to the cyanate ester compound, generation of carbon dioxide by hydrolysis of the cyanate ester compound or a carbamate compound by a side reaction is caused. Can be suppressed.
Further, the urea compound formed by the reaction of the carbodiimide compound with water can react with the cyanate ester compound at the active hydrogen site, so that it is consumed to form a crosslinked structure when the resin composition is cured, and the mechanical strength, etc. Does not impair the physical properties of the cured product. Therefore, the resin composition of the present invention can form a cured product in which the occurrence of a non-uniform structure such as bubbles and gels is sufficiently suppressed and which has excellent physical properties.

The carbodiimide compound contained in the resin composition of the present invention may be a compound having at least one carbodiimide group represented by (-N=C=N-) in the molecule, and the following general formula (9):

^(Wherein, R ^{32, R 34} are the same or different, ^{.R 33} representing a monovalent hydrocarbon group which may 1 to 50 carbon atoms which may have a substituent are the same or different, substituted It represents a divalent hydrocarbon group having 1 to 50 carbon atoms which may have a group, and n ⁵ represents a number of 0 to 10,000).

In the general formula (9), the hydrocarbon group represented by R ^{32 to} R ³⁴ has preferably 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and further preferably 1 to 20 carbon atoms. ..
As the monovalent hydrocarbon group for R ³² and R ³⁴ , a chain or cyclic alkyl group, alkenyl group or alkynyl group which is an aliphatic group; an aryl group which is an aromatic group; or two or more thereof It may be any of the groups in which
The divalent hydrocarbon group for R ³³ may be any of divalent groups obtained by removing one hydrogen atom from the above monovalent hydrocarbon group.
In the above general formula (9), R ^{32 to} R ³⁴ may have a substituent, and examples of the substituent include a hydroxyl group, an amino group, a nitro group, and a halogen atom.
R ^{32 to} R ³⁴ may have one or two or more of these substituents. Further, it may have one type of substituent or two or more types of substituent.
In the general formula (9), n ⁵ is preferably 0 to 200, more preferably 0 to 150, and further preferably 0 to 100.

Specific examples of the carbodiimide compound include N,N'-diphenylcarbodiimide, N,N'-di-cyclohexylcarbodiimide, N,N'-di-2,6-dimethylphenylcarbodiimide, N,N'-diisopropylcarbodiimide, N,N'-dioctyldecylcarbodiimide, N,N'-di-o-toluylcarbodiimide, N,N'-di-p-toluylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N' -Di-p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-di-p-chlorophenylcarbodiimide, N,N'-di-o-chlorophenylcarbodiimide, N, N'-di-3,4-dichlorophenylcarbodiimide, N,N'-di-2,5-dichlorophenylcarbodiimide, N,N'-p-phenylene-bis-o-toluylcarbodiimide, N,N' -P-phenylene-bis-dicyclohexylcarbodiimide, N,N'-p-phenylene-bis-di-p-chlorophenylcarbodiimide, N,N'-2,6,2',6'-tetraisopropyldiphenylcarbodiimide, N , N'-hexamethylene-bis-cyclohexylcarbodiimide, N,N'-ethylene-bis-diphenylcarbodiimide, N,N'-ethylene-bis-dicyclohexylcarbodiimide, N-toluyl-N'-cyclohexylcarbodiimide, N,N' -Di-2,6-diisopropylphenylcarbodiimide, N,N'-di-2,6-di-tert-butylphenylcarbodiimide, N-toluyl-N'-phenylcarbodiimide, N,N'-benzylcarbodiimide, N- Octadecyl-N'-phenylcarbodiimide, N-benzyl-N'-phenylcarbodiimide, N-octadecyl-N'-tolylcarbodiimide, N-cyclohexyl-N'-tolylcarbodiimide, N-phenyl-N'-tolylcarbodiimide, N- Benzyl-N'-tolylcarbodiimide, N,N'-di-o-ethylphenylcarbodiimide, N,N'-di-p-ethylphenylcarbodiimide, N,N'-di-o-isopropylphenylcarbodiimide, N,N '-Di-p-isopropylphenylcarbodiimide, N,N'-di-o-isobutylphenylcarbodiimide, N,N'-di-p-isobutylphenylcarbodiimide, N,N'-di-2,6-diethylphene Nylcarbodiimide, N,N'-di-2-ethyl-6-isopropylphenylcarbodiimide, N,N'-di-2-isobutyl-6-isopropylphenylcarbodiimide, N,N'-di-2,4,6- Monocarbodiimide compounds such as trimethylphenylcarbodiimide, N,N'-di-2,4,6-triisopropylphenylcarbodiimide, N,N'-di-2,4,6-triisobutylphenylcarbodiimide; poly(1,6) -Hexamethylenecarbodiimide), poly(4,4'-methylenebiscyclohexylcarbodiimide), poly(1,3-cyclohexylenecarbodiimide), poly(1,4-cyclohexylenecarbodiimide), poly(4,4'-diphenylmethanecarbodiimide) ), poly(3,3′-dimethyl-4,4′-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(tolylcarbodiimide), poly Examples thereof include polycarbodiimide compounds such as (diisopropylcarbodiimide), poly(methyl-diisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), and poly(triisopropylphenylenecarbodiimide). These carbodiimide compounds may be used alone or in combination of two or more.

Among the above carbodiimide compounds, polycarbodiimide compounds are preferable. Examples of the polycarbodiimide compound include an aliphatic polycarbodiimide in which R ³³ in the general formula (9) is an aliphatic group and an aromatic polycarbodiimide in which R ³³ has an aromatic group. Is preferred because it is easier to bleed than aromatic polycarbodiimide, and the aliphatic group is preferably linear rather than branched.

When a polycarbodiimide compound is used as the carbodiimide compound, the weight average molecular weight thereof is preferably 100 or more and 100,000 or less, more preferably 500 or more and 10,000 or less, from the viewpoint of safety and ease of handling. ..
The weight average molecular weight of the carbodiimide compound can be determined by GPC (gel permeation chromatography) measurement under the following measurement conditions.
Measuring instrument: HLC-8120GPC (trade name, manufactured by Tosoh Corporation)
Molecular weight column: TSK-GEL GMHXL-L and TSK-GELG5000HXL (both manufactured by Tosoh Corporation) were connected in series and used as eluent: tetrahydrofuran (THF)
Standard substance for calibration curve: polystyrene (manufactured by Tosoh Corporation)
Measurement method: The object to be measured is dissolved in THF so that the solid content is about 0.2% by mass, and the substance filtered through a filter is used as a measurement sample to measure the molecular weight.

The carbodiimide compound can be produced, for example, by heating an organic isocyanate to cause a decarboxylation reaction in the presence of a suitable catalyst to form a carbodiimide bond group.
The formation of the carbodiimide-bonded group can be confirmed by the disappearance of the absorption peak of the isocyanate group at 2260 cm ^{−1 and} the formation of the absorption peak of the carbodiimide-bonded group.

The carbodiimide compound may be, for example, in addition to the above-mentioned basic production method, for example, US Pat. And the method disclosed in J. et al. Org. Chem. 28, 2069 (1963), Chem. , Review 81, 619 (1981). Further, as disclosed in JP-A-5-178954, JP-A-6-56950, etc., it can be carried out without solvent.

A commercial item can also be used as said carbodiimide compound. Examples of commercially available commercially available aliphatic polycarbodiimide compounds include carbodilite LA-1, carbodilite HMV-8CA, carbodilite V-05, carbodilite V-07, carbodilite HMV-15CA containing no isocyanate group, and carbodilite V-03. , Carbodilite V-09 (above, manufactured by Nisshinbo Chemical Co., Ltd.) and the like. In addition, examples of commercially available aromatic polycarbodiimide compounds include stavaxol P, stavaxol P-400, and stavaxol I (all manufactured by Rhein Chemie Co., Ltd.).

In the curable resin composition of the present invention, the blending ratio of the carbodiimide compound is preferably 0.01 to 5 mass% with respect to 100 mass% of the cyanate ester compound in the curable resin composition. By using such a ratio, the occurrence of a non-uniform structure can be suppressed more sufficiently, and the cured product can have an excellent appearance. It is more preferably 0.05 to 4% by mass, and even more preferably 0.1 to 3% by mass, relative to 100% by mass of the cyanate ester compound.

[Inorganic filler]
The resin composition in the present invention preferably further contains an inorganic filler. The inorganic filler is not particularly limited, and those which are used as usual sealing materials for mounting substrates and the like may be used. For example, silica filler and the like can be mentioned.

The content ratio of the inorganic filler in the resin composition is preferably 50 to 95 mass% with respect to 100 mass% of the total amount of the resin composition. It is more preferably 60 to 93% by mass, and further preferably 70 to 90% by mass. By using such a large amount of the inorganic filler, it is possible to sufficiently prevent warpage of the substrate after curing when used for obtaining a sealing material for a mounting substrate or the like.

[Other ingredients]
The resin composition in the present invention may also contain other components than the above components, if necessary. For example, a curing agent; a curing accelerator; an inorganic filler; a volatile component such as an organic solvent or a diluent; a flame retardant; a reinforcing agent; a coupling agent; a stress relaxation agent; a release agent; a stabilizer; a coloring agent; a plasticizer; Examples include a softening agent; various rubber substances; a photosensitizer; a pigment; and the like, and one or more of these can be used.
Since the resin composition in the present invention may cause a problem when it contains a large amount of volatile components, it is desired that the resin composition does not contain volatile components. For example, the content of the volatile components in 100% by mass of the resin composition is The proportion is preferably 10% by mass or less. It is more preferably 5 mass% or less, still more preferably 3 mass% or less, and particularly preferably substantially free of volatile components.

<Substrate>
As the substrate included in the semiconductor device of the present invention, a substrate generally used as a substrate can be used. For example, aluminum oxide, aluminum nitride, silicon nitride, zirconium oxide, zirconium nitride, titanium oxide, titanium nitride, silicon oxide, sapphire or One of a ceramic substrate containing a mixture of these, a metal substrate containing Cu, Fe, Ni, Cr, Al, Ag, Au, Ti or an alloy thereof, a glass epoxy substrate, a BT resin substrate, a glass substrate, a resin substrate, or the like, or Two or more types can be used.

<Semiconductor element>
The semiconductor element used in the semiconductor device of the present invention is not particularly limited, but as described above, the semiconductor device of the present invention does not cause peeling in the semiconductor device even when used at a high temperature exceeding 200° C. for a long period of time. It is one of the preferred embodiments of the present invention to use a next-generation power semiconductor such as SiC or GaN, which is sufficiently suppressed and has a high temperature of more than 200° C. during use.

2. Method for manufacturing semiconductor device The present invention is also a method for manufacturing a semiconductor device including a substrate and a semiconductor element, wherein the manufacturing method includes metal particles and an inorganic component different from the metal particles. After the conductive composition is applied on the substrate, a step of placing a semiconductor element on the substrate and a step of heating the substrate on which the semiconductor element is placed at 150° C. to 300° C. under an atmosphere or an oxygen gas atmosphere are included. It is also a method of manufacturing a semiconductor device.

The method for applying the conductive composition in the step of applying the conductive composition on a substrate is not particularly limited, and includes screen printing, offset printing, inkjet printing, flexographic printing, gravure printing, stamping, and dispensing. Although any method such as squeegee printing, silk screen printing, spraying and brush coating may be used, among these, the screen printing method, stamping and dispensing are preferred.

The thickness of the coating film formed on the substrate by the step of coating the conductive composition on the substrate is preferably 20 to 500 μm. The thickness is more preferably 30 to 300 μm, still more preferably 50 to 200 μm.
The film thickness of the coating film can be measured by a non-contact type laser microscope, a contact type surface roughness measuring device, an optical interference type film thickness measuring device, an ellipsometer or the like.

The step of heating the substrate on which the semiconductor element is installed in the atmosphere or oxygen gas atmosphere may be performed at 150°C to 300°C, but is preferably performed at 200°C to 300°C. More preferably, it is performed at 250 to 300°C.
The heating time at 150°C to 300°C is not particularly limited, but is preferably 5 to 300 minutes. More preferably, it is 10 to 150 minutes.
The heating at 150° C. to 300° C. may be performed while pressing the substrate on which the semiconductor element is installed. The heating step may include a step of volatilizing the solvent before heating at 150°C to 300°C, and the heating temperature in that case may be a temperature lower than 150°C. The heating temperature in the step of volatilizing the solvent may be appropriately selected depending on the solvent used, but can be, for example, room temperature to 100°C.

The above-mentioned manufacturing method is further a substrate on which a semiconductor element is installed by pressure-injecting a resin composition containing a molten cyanate ester compound and/or a maleimide compound into a mold in which the substrate after the heating step is arranged. It is preferable that the method includes the step of sealing.
When sealing is performed using a resin composition containing a cyanate ester compound and/or a maleimide compound, a good sealing film having high adhesion to a substrate on which a semiconductor element is installed is obtained by using such a method. Can be formed.
As a method for performing such a sealing step, a transfer molding method using a transfer molding machine is preferable.

When the above-mentioned sealing step is performed, the resin composition containing the molten cyanate ester compound and/or the maleimide compound preferably has a viscosity at 150°C of 0.1 to 60 Pa·s. When the resin composition has such an appropriate viscosity, for example, it becomes excellent in handleability at the time of application. It is more preferably 0.2 to 40 Pa·s. When casting at room temperature, it is preferably liquid at room temperature and preferably 5 to 1000 Pa·s. This is because if the viscosity is too low, the inorganic filler may settle, and if the viscosity is too high, the irregularities to be sealed may not be filled. More preferably, it is 10 to 500 Pa·s. In addition, the preferable range of the viscosity at 175° C. of the resin composition is the same as the preferable range of the viscosity at 150° C. described above.
The viscosity of the resin composition can be measured using, for example, an E-type viscometer (manufactured by Brookfield) or a flow tester CFT-500D (manufactured by Shimadzu Corporation).

In the encapsulation step, the method of curing the resin composition injected under pressure is not particularly limited, but it can be cured by, for example, heat curing. The curing method is not particularly limited, and a normal heat curing method may be adopted. For example, the heat curing temperature is preferably 70 to 250°C, more preferably 100 to 250°C. The curing time is preferably 1 to 15 hours, more preferably 2 to 10 hours.

The cured product preferably has a glass transition temperature of 180° C. or higher as measured by a thermomechanical analyzer (DMA). Thereby, for example, it can be more suitably used as an electronic mounting material such as a sealing material for a mounting substrate. The temperature is more preferably 190°C or higher, further preferably 195°C or higher, and particularly preferably 200°C or higher.

The method for manufacturing a semiconductor device of the present invention, after applying the conductive composition on a substrate, a step of installing a semiconductor element on the substrate, and may include other steps other than the sealing step, The other steps include, for example, a step of wire bonding between the semiconductor element and the terminal after the step of installing the semiconductor element on the substrate.

The semiconductor device of the present invention has the above-mentioned structure, and uses a conductive composition in which an inorganic component different from the metal particles is added to the metal particles as a die attach material, and a semiconductor element using the die attach material. By sealing with a resin composition containing a cyanate ester compound and/or a maleimide compound, the occurrence of peeling in a semiconductor device is sufficiently suppressed even when used at a high temperature exceeding 200° C. for a long period of time. Therefore, in particular, it can be suitably used for various applications as a semiconductor device including a next-generation power semiconductor such as SiC or GaN.

It is the figure which showed the outline of the evaluation system of the power cycle characteristic evaluation in an Example. It is a figure which showed the ultrasonic flaw detection test result of the semiconductor package of the comparative example 1 before a heat cycle (left) and after a heat cycle (right). It is a figure which showed the ultrasonic flaw detection test result of the semiconductor package of the comparative example 2 before a heat cycle (left) and after a heat cycle (right). FIG. 6 is a diagram showing the results of ultrasonic flaw detection tests before (left) and after (right) a heat cycle of the semiconductor package of Example 1.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "part" means "part by weight" and "%" means "mass %".

<Molecular weight measurement>
The number average molecular weight and the weight average molecular weight of the siloxane compound were determined by GPC (gel permeation chromatography) measurement under the following measurement conditions.
Measuring instrument: HLC-8120GPC (trade name, manufactured by Tosoh Corporation)
Molecular weight column: TSK-GEL GMHXL-L and TSK-GELG5000HXL (both manufactured by Tosoh Corporation) were connected in series and used as eluent: tetrahydrofuran (THF)
Standard substance for calibration curve: polystyrene (manufactured by Tosoh Corporation)
Measurement method: The object to be measured is dissolved in THF so that the solid content is about 0.2% by mass, and the substance filtered through a filter is used as a measurement sample to measure the molecular weight.

<Measurement of glass transition temperature (Tg)>
The glass transition temperature of the resin composition was measured using a dynamic viscoelasticity measuring device (device name DMA7100, manufactured by Hitachi High-Tech Science Co., Ltd.). The measurement temperature range was −100° C. to 400° C., the heating rate was 5° C./min, and the measurement was performed in a nitrogen atmosphere.

Synthesis example 1
Synthesis of poly{γ-(5-norbornene-2,3-imido)propylsilsesquioxane} In a 500 mL four-necked flask equipped with a stirrer, a temperature sensor, and a cooling tube, 87.9 g of diglyme previously dried with a molecular sieve. Then, 142.5 g of 3-aminopropyltrimethoxysilane was added, and the temperature was raised to 100° C. under a stream of dry nitrogen while stirring to remove water in the system. Next, 131.8 g of 5-norbornene-2,3-dicarboxylic acid anhydride was added in four portions over 30 minutes while maintaining the reaction liquid temperature at 100°C. It was confirmed by high performance liquid chromatography that 5-norbornene-2,3-dicarboxylic acid anhydride was completely consumed 9 hours after completion of the addition.
Subsequently, 42.9 g of deionized water was added all at once to raise the temperature so that the by-product methanol was refluxed in the cooling tube, and the temperature was maintained at 95°C for 10 hours. Then, the cooling tube was replaced with a partial condenser and the temperature was started again. Then, the reaction liquid temperature was reached to 120° C. over 3 hours while collecting the by-product methanol and condensed water. When 120° C. is reached, 0.65 g of cesium carbonate is added and the temperature rise is started as it is, while reaching the 160° C. over 3 hours while collecting the condensed water, the reaction is performed by keeping the same temperature for 2 hours and cooling to room temperature. Product A was obtained.
The reaction product A was a dark brown high-viscosity liquid having a nonvolatile content of 70.0%, and the number average molecular weight was 2340 and the weight average molecular weight was 2570 as measured by GPC. ¹ H-NMR and ¹³ C-NMR were measured, and it was confirmed that the compound of the following formula (10) (siloxane compound 1) was contained.
¹ H-NMR: 0.25-0.45 (bs, 2H), 1.2-1.45 (bs, 2H), 1.47 (dd, 2H), 3.0-3.2 (bs, 4H), 3.4-3.6 (bs, 2H), 5.8-6.0 (bs, 2H)
¹³ C-NMR: 9.7, 21.5, 40.4, 44.9, 45.7, 50.1, 134.2, 178.0.

Synthesis example 2
Synthesis of poly{(cis-4-cyclohexene-1,2-imido)propylsilsesquioxane} Instead of 131.8 g of 5-norbornene-2,3-dicarboxylic acid anhydride of Synthesis Example 1, cis-4-cyclohexene was synthesized. A reaction product B was obtained by the same procedure as in Synthesis Example 1 except that 122.2 g of -1,2-dicarboxylic acid anhydride was used. The reaction product B was a dark brown high-viscosity liquid having a nonvolatile content of 70.0%, and the number average molecular weight was 2041 and the weight average molecular weight was 2838 as measured by GPC. ¹ H-NMR and ¹³ C-NMR were measured, and it was confirmed that the compound of the following formula (11) (siloxane compound 2) was contained.
¹ H-NMR: 0.25-0.55 (bs, 2H), 1.3-1.5 (bs, 2H), 2.0-2.5 (dd, 4H), 2.9-3. 1 (bs, 2H), 3.2-3.35 (bs, 2H), 5.65-5.8 (bs, 2H)
¹³ C-NMR: 10.0, 21.0, 23.8, 39.0, 41.1, 127.8, 180.5.

Preparation Example 1 (Preparation of semiconductor encapsulating material composition)
Each raw material was weighed with the composition shown in Table 1 below, and then kneaded using a heating roll kneader to obtain a compound. The surface temperature of the kneading roll was set to 72° C., and the kneading time was set to 5 minutes. The compound was made into a powder having a size of 1 mm or less by using a crusher, and then made into a tablet shape having a diameter of 18 mm and a weight of 7 g by using a tableting machine and used as a semiconductor sealing material.

The cyanate ester compound, maleimide compound, carbodiimide compound, epoxy compound, aromatic amine compound, phenol compound, imidazole compound, and silane coupling agent listed in Table 1 are as follows.
Cyanate ester compound: Phenol novolac type cyanate ester compound represented by the following formula (12) (Product name "Primaset PT30", manufactured by Lonza Japan)
Maleimide compound: a bismaleimide compound having a structure represented by the following formula (13) (product name "Bismaleimide BMI80", manufactured by KAI Kasei)
Carbodiimide compound: Aliphatic polycarbodiimide compound (Product name "Carbodilite V-05", manufactured by Nisshinbo Chemical Inc.)
Epoxy compound: tris(hydroxyphenyl)methane type epoxy resin (product name "EPPN-501HY", manufactured by Nippon Kayaku Co., Ltd.)
Aromatic amine compound: 4,4'-diaminodiphenyl sulfone (Product name "Seika Cure S", Wakayama Seika Kogyo Co., Ltd.)
Phenol compound: Phenol novolac curing agent (product name "TD-2131", manufactured by DIC)
Imidazole compound: 2-phenyl-4-methyl-5-hydroxymethylimidazole (Product name "Curesol 2P4MHZ", manufactured by Shikoku Chemicals Co., Ltd.)
Silane coupling agent: N-phenyl-3-aminopropyltrimethoxysilane (product name "KBM573", manufactured by Shin-Etsu Chemical Co., Ltd.)

Preparation Example 2 (Preparation of die attach material)
After mixing the following two types of silver powder and two types of inorganic particles with the composition shown in Table 2, washing with ethanol, mixing with an ethylene glycol solvent after drying and forming a paste using a rotation-revolution type stirring mixer, The syringe was filled and defoamed, and used as a sintered silver die attach material.
<Silver powder>
(1) Product name “AgC-239” manufactured by Fukuda Metal Foil & Powder Co., Ltd.: average particle diameter (median diameter) is 6 μm, and BET specific surface area is 5.0 m ² /g.
(2) Mitsui Mining & Smelting Co., Ltd., product name “FHD: average particle diameter (median diameter) 0.3 μm, BET specific surface area 1.70 m ² /g
<Inorganic particles>
(3) Product made by Superior Graphite, product name "HSC059": material is SiC, average particle size (median diameter) is 0.6 µm, polygonal shape (4) Nippon Kayaku Co., Ltd. "KE-P30": Material is silica, average Particle size 0.3 μm, spherical shape

Examples 1 to 4 and Comparative Examples 1 and 2 (production of semiconductor package)
The die attach materials 1 to 3 shown in Table 2 were applied onto the pad area of the copper TO247 lead frame. After that, a 1.5 mm□ SiC Schottky barrier diode was placed on the die attach material and left in the air atmosphere for 30 minutes on a hot plate whose surface temperature was adjusted to 250°C. After cooling, the diode element and the terminal were wire-bonded with an aluminum wire having a diameter of 350 μm, and ultrasonic cleaning was performed in ethanol to mount the component on the substrate.
This substrate with parts and the sealing materials 1 to 3 were set in a low-pressure transfer molding machine, and a TO247 type semiconductor package was produced by insert molding of a copper lead frame. Molding conditions were set to a mold temperature of 180° C., a clamp pressure of 294 KN, a preheating time of 5 seconds, an injection pressure of 15 KN, an injection speed of 0.5 mm/s, a transfer time of 28 seconds, and a curing time of 360 seconds. The obtained molded product was left for 5 hours in an inert oven under a nitrogen flow at 270° C. for post-cure treatment to obtain a power device for evaluation.

<Reliability evaluation 1 (heat cycle test)>
In order to evaluate the reliability of the semiconductor packages of Examples and Comparative Examples, a heat cycle test was carried out to examine the influence on the internal structure of the package due to the generation of internal stress when repeatedly exposed to a cold environment. The heat cycle test conditions were such that the cooling lower limit condition was left at −50° C. for 30 minutes, the heating upper limit condition was left at 250° C. for 30 minutes, and the cooling/heating time was about 3 minutes, and 500 cycles were carried out.
The internal structure of the package was confirmed using an ultrasonic flaw detector (FineSATIII, manufactured by Hitachi Power Solutions), and if peeling was observed at the interface between the internal components and the encapsulant inside the package, x was found, but there was no peeling but bubbles or gel. When a large number of non-uniform structures such as particles were observed, it was evaluated as Δ.

<Reliability evaluation 2 (power cycle characteristic evaluation)>
(Power cycle evaluation)
The system used for the measurement is shown in FIG. Connect a DC power supply to the power device for evaluation, attach a thermocouple to the surface of the power device, track the temperature change with a multimeter, and stop the current when the specified temperature is reached while flowing a constant current by computer control. This was repeated by setting one cycle of cooling the power device to room temperature and returning it to room temperature, and the number of cycles at which current stopped flowing was examined. As power cycle conditions, the case temperature (power device surface temperature, Tc) has an upper limit of 250° C., a lower limit of room temperature, a forward current value of 8 A is applied to generate heat, and after reaching Tc=250° C., the current value is set to 2 A. It was dropped and set to hold for 10 seconds. The number of tests was set at 15 for each sample, and the ratio of passing the tests of 500 cycles, 1000 cycles and 3000 cycles was examined.
Evaluation system outline:
DC power supply: manufactured by Takasago Seisakusho, product name "ZX-400LAN"
Multimeter: product name "2701 multimeter" manufactured by KEITHLEY

Table 3 shows the types of die attach materials and sealing materials used in each example and comparative example, and the results of the heat cycle test and the power cycle test. 2 to 4 show ultrasonic flaw detection test results of the internal structure of the power device before and after the heat cycle test.

In the heat cycle test, regardless of whether or not inorganic particles are added to the die attach material, the use of an imide-based material as the encapsulant causes peeling or cracking inside the package against cold heat shock at a severe temperature difference. It was possible to suppress physical damage such as.
However, in the power cycle test, in the comparative example, about 20% to 30% of the samples fail to function in about 500 cycles corresponding to the beginning of the cycle test, whereas in the example, it is as long as 3000 cycles. The function was not impaired even in the cycle, and it could be used as a power device.
Not only is it considered that the electrochemical changes occur around the chip, the die attach material, and the wire due to the electric current, but there is also the effect of uneven distribution of thermal stress due to the temperature gradient between the chip periphery and the surface of the encapsulant. It is conceivable that it is expected that these effects can be suppressed to a minimum by adding inorganic particles to the die attach material.

Claims (5)

A semiconductor device including a substrate and a semiconductor element,
The semiconductor device uses a conductive composition containing metal particles and an inorganic component different from the metal particles as a die attach material ,
A resin composition containing a cyanate ester compound and/or a maleimide compound is used as a sealing material,
The conductive composition has a content ratio of an adhesive component of 15% by mass or less with respect to the entire conductive composition . The conductive composition includes metal particles having an average particle diameter of 1.0 to 9.9 μm in median diameter and metal particles having an average particle diameter of 0.1 to 0.99 μm in median diameter. The semiconductor device according to claim 1, wherein the semiconductor device is a semiconductor device. The resin composition has the following average composition formula (4);
XaYbZcSiOd (4)
(In the formula, X is the same or different and represents an organic skeleton containing an imide bond. Y is the same or different and represents at least one selected from the group consisting of a hydrogen atom, a hydroxyl group, a halogen atom and an OR group. Z is the same or different and represents an organic group containing no imide bond, and R is the same or different and is at least 1 selected from the group consisting of an alkyl group, an acyl group, an aryl group and an unsaturated aliphatic residue. Represents a species and may have a substituent, a, b and c are 0 or a number less than 3 and d is a number less than 2 which is not 0 and a+b+c+2d=4). The semiconductor device according to claim 1 or 2 , further comprising a siloxane compound. A method of manufacturing a semiconductor device including a substrate and a semiconductor element,
The manufacturing method, metal particles, and, seen containing a different inorganic components and metal particles, for the entire content is conductive composition of the adhesive component, a conductive composition is 15 wt% or less on a substrate After applying, a step of installing the semiconductor element on the substrate,
And a step of heating the substrate on which the semiconductor element is mounted at 150° C. to 300° C. in an atmosphere or an oxygen gas atmosphere. The manufacturing method further includes a substrate on which a semiconductor element is installed by pressure-injecting a resin composition containing a molten cyanate ester compound and/or a maleimide compound into a mold in which the substrate after the heating step is arranged. 5. The method for manufacturing a semiconductor device according to claim 4 , further comprising the step of encapsulating.