Conductive resin compositions, high thermal conductivity materials, and semiconductor devices

Abstract

To provide a conductive resin composition that has excellent thermal conductivity and storage elastic modulus, as well as excellent adhesion to a substrate or the like.SOLUTION: The conductive resin composition of the present invention comprises (A) a conductive particle, (B) a polymer containing polyrotaxane, and (C) a monomer containing a compound having a double bond at the terminal, and in which the ratio of the monomer (C) to the total 100 mass% of the polymer (B) and the monomer (C) is 50 mass% to 95 mass%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a conductive resin composition, a high thermal conductivity material, and a semiconductor device. [Background technology]

[0002] In the manufacture of semiconductor devices, conductive resin compositions possessing both conductivity and adhesive properties are sometimes used. Various conductive resin compositions possessing both conductivity and adhesive properties have been developed to date. Patent Document 1 describes a thermosetting resin composition containing plate-type silver nanoparticles, silver powder different from plate-type silver nanoparticles, and a thermosetting resin.

[0003] Patent Document 2 describes a conductive adhesive containing conductive particles with a melting point of 300°C or higher, such as silver particles, solder powder with a melting point of 230°C or lower, a resin, and an activator. Patent Document 3 describes a conductive composition comprising two or more polymer components with different dielectric constants and a conductive metal filler such as a silver filler.

[0004] Patent Document 4 describes a conductive resin composition containing a predetermined amount of polyrotaxane and conductive particles. The document states that this conductive resin composition can form a film that is resistant to damage from external forces. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-194013 [Patent Document 2] Japanese Patent Publication No. 2016-222894 [Patent Document 3] Japanese Patent Publication No. 2019-182963 [Patent Document 4] Japanese Patent Publication No. 2020-164773 [Overview of the Initiative]

Problems to be Solved by the Invention

[0006] However, the conductive adhesives described in Patent Documents 1 to 4 had room for improvement in thermal conductivity and product reliability.

Means for Solving the Problems

[0007] The present inventors have found that the above problems can be solved by including a polymer containing polyrotaxane and a monomer containing a compound having a double bond at the terminal in a predetermined amount, and have completed the present invention. That is, the present invention can be shown as follows.

[0008] According to the present invention, (A) Conductive particles, (B) A polymer containing polyrotaxane, (C) A monomer containing a compound having a double bond at the terminal, are included, and there is provided a conductive resin composition in which the ratio of the monomer (C) in a total of 100% by mass of the polymer (B) and the monomer (C) is 50 to 95% by mass.

[0009] According to the present invention, there is provided a high thermal conductivity material obtained by sintering the conductive resin composition.

[0010] According to the present invention, a base material, and a semiconductor element mounted on the base material via an adhesive layer, are provided, and there is provided a semiconductor device in which the adhesive layer is formed by sintering the conductive resin composition.

[0011] In the present invention, the "non-volatile component" refers to a component other than volatile components such as organic solvents. The amount of the non-volatile component in a certain conductive resin composition can be known from the mass difference before and after heating at 175 ° C for 1 hour under atmospheric pressure, for example, by applying the conductive resin composition on a substrate.

Advantages of the Invention

[0012] According to the present invention, it is possible to provide a conductive resin composition that has excellent thermal conductivity and storage modulus, as well as excellent adhesion to substrates and the like. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic cross-sectional view showing an example of a semiconductor device. [Figure 2] This is a schematic cross-sectional view showing an example of a semiconductor device. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted as appropriate. In this specification, the notation "a~b" in descriptions of numerical ranges means a or more and b or less, unless otherwise specified. For example, "1~5 mass%" means "1 mass% or more and 5 mass% or less."

[0015] In this specification, when a group (atomic group) is not specified as substituted or unsubstituted, it includes both unsubstituted and substituted groups. For example, "alkyl group" includes not only unsubstituted alkyl groups but also substituted alkyl groups. In this specification, the term "(meth)acrylic" refers to a concept that encompasses both acrylic and methacrylic. The same applies to similar terms such as "(meth)acrylate" and "(meth)acryloyl."

[0016] The conductive resin composition of this embodiment is (A) Conductive particles and (B) A polymer containing polyrotaxane, (C) A monomer containing a compound having a double bond at its terminus, and Furthermore, the ratio of monomer (C) to polymer (B) in a total of 100% by mass is 50 to 95% by mass, preferably 55 to 92% by mass, and more preferably 60 to 90% by mass. This makes it possible to provide a conductive resin composition that has excellent thermal conductivity and storage modulus, as well as excellent adhesion to substrates and the like.

[0017] [Conductive particles (A)] The conductive resin composition of this embodiment contains conductive particles (A).

[0018] The conductive particles (A) are, for example, metal particles. For instance, they can be metal particles of copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, or alloys thereof. Among these, due to their high conductivity and availability, the conductive particles (A) preferably include silver-containing particles or copper-containing particles, and more preferably silver-containing particles. Silver-containing particles can undergo sintering (sintering) through appropriate heat treatment, forming a particle-linked structure (sintered structure).

[0019] In particular, the presence of silver-containing particles in the conductive resin composition, especially silver particles with relatively small particle size and relatively large specific surface area, facilitates the formation of a sintering structure even during heat treatment at relatively low temperatures (around 180°C). Preferred particle sizes will be described later.

[0020] There are no particular restrictions on the shape of the silver-containing particles, and known shapes such as spherical, dendritic, string-like, flaky, aggregated, and polyhedral shapes can be mentioned. In this embodiment, one or more, preferably two or more, silver-containing particles of these shapes can be included. This results in superior conductivity. In this embodiment, it is preferable to include two or more types of silver-containing particles selected from spherical, flaky, aggregated, and polyhedral shapes, more preferably spherical silver-containing particles 1 and one or more types of silver-containing particles 2 selected from flaky, aggregated, and polyhedral shapes, and particularly preferable to include spherical silver-containing particles 1 and flaky silver-containing particles 2-1. This further improves the contact rate between the silver-containing particles, so that a network is easily formed after sintering of the conductive resin composition, further improving thermal conductivity and electrical conductivity. By including silver-containing particles 2, it is possible to suppress resin cracks in molded products obtained from conductive resin compositions and to suppress the coefficient of thermal expansion.

[0021] In this embodiment, "spherical" is not limited to a perfect sphere, but also includes shapes with slight irregularities on the surface. The degree of circularity is, for example, 0.90 or higher, preferably 0.92 or higher, and more preferably 0.94 or higher. The silver-containing particles may have their surface treated with a carboxylic acid, a saturated fatty acid having 4 to 30 carbon atoms, a monovalent unsaturated fatty acid having 4 to 30 carbon atoms, a long-chain alkyl nitrile, or the like.

[0022] The silver-containing particles may be (i) particles consisting substantially of silver only, or (ii) particles consisting of silver and other components. Alternatively, (i) and (ii) may be used in combination as the metal-containing particles.

[0023] In this embodiment, the silver-containing particles are particularly preferably silver-coated resin particles in which the surface of the resin particles is coated with silver. This makes it possible to prepare a conductive resin composition that yields a cured product with superior thermal conductivity and storage modulus.

[0024] Silver-coated resin particles, having a silver surface and a resin core, are thought to have good thermal conductivity and be softer than particles made solely of silver. Therefore, using silver-coated resin particles makes it easier to design appropriate values ​​for thermal conductivity and storage modulus.

[0025] Typically, increasing the amount of silver-containing particles is considered to improve thermal conductivity. However, because metals are generally "hard," too much silver-containing particle can result in an excessively high elastic modulus after sintering. By having some or all of the silver-containing particles be silver-coated resin particles, it is possible to easily design a conductive resin composition that can produce a cured product with the desired thermal conductivity and storage modulus.

[0026] In the case of silver-coated resin particles, it is sufficient for the silver layer to cover at least a portion of the surface of the resin particle. Of course, the entire surface of the resin particle may also be covered with silver.

[0027] Specifically, in silver-coated resin particles, the silver layer covers preferably 50% or more, more preferably 75% or more, and even more preferably 90% or more of the surface of the resin particles. Particularly preferably, in silver-coated resin particles, the silver layer covers substantially the entire surface of the resin particles. From another perspective, it is preferable that when silver-coated resin particles are cut at a certain cross-section, a silver layer is observed around the entire perimeter of that cross-section.

[0028] From another perspective, the mass ratio of resin to silver in the silver-coated resin particles is, for example, 90 / 10 to 10 / 90, preferably 80 / 20 to 20 / 80, and more preferably 70 / 30 to 30 / 70.

[0029] Examples of "resins" in silver-coated resin particles include silicone resin, (meth)acrylic resin, phenolic resin, polystyrene resin, melamine resin, polyamide resin, and polytetrafluoroethylene resin. Of course, other resins may also be used. Furthermore, only one type of resin may be used, or two or more types of resins may be used in combination. From the viewpoint of elastic properties and heat resistance, silicone resin or (meth)acrylic resin is preferred as the resin.

[0030] The silicone resin may also consist of particles composed of organopolysiloxanes obtained by polymerizing organochlorosilanes such as methylchlorosilane, trimethyltrichlorosilane, and dimethyldichlorosilane. Alternatively, the silicone resin may have a basic framework consisting of organopolysiloxanes further cross-linked in three dimensions.

[0031] (Meth)acrylic resin can be a resin obtained by polymerizing a monomer containing a (meth)acrylic acid ester as the main component (50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more). Examples of (meth)acrylic acid esters include at least one compound selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-propyl (meth)acrylate, chloro-2-hydroxyethyl (meth)acrylate, diethylene glycol mono (meth)acrylate, methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and isovonol (meth)acrylate. Furthermore, the monomer component of the acrylic resin may contain small amounts of other monomers. Examples of such other monomer components include styrene monomers. For silver-coated (meth)acrylic resins, please also refer to the description in Japanese Patent Publication No. 2017-126463.

[0032] Various functional groups may be introduced into silicone resins or (meth)acrylic resins. The functional groups that can be introduced are not particularly limited. Examples include epoxy groups, amino groups, methoxy groups, phenyl groups, carboxyl groups, hydroxyl groups, alkyl groups, vinyl groups, mercapto groups, and the like.

[0033] The resin particle portion of the silver-coated resin particles may contain various additive components, such as low-stress modifiers. Examples of low-stress modifiers include butadiene styrene rubber, butadiene acrylonitrile rubber, polyurethane rubber, polyisoprene rubber, acrylic rubber, fluororubber, liquid organopolysiloxane, and liquid synthetic rubbers such as liquid polybutadiene. In particular, when the resin particle portion contains silicone resin, the inclusion of a low-stress modifier can improve the elastic properties of the silver-coated resin particles.

[0034] The shape of the resin particles in the silver-coated resin particles is not particularly limited. Preferably, a combination of spherical and other non-spherical shapes, such as flattened, plate-shaped, or needle-shaped, is preferred.

[0035] The specific gravity of the silver-coated resin particles is not particularly limited, but the lower limit is, for example, 2 or more, preferably 2.5 or more, and more preferably 3 or more. The upper limit of the specific gravity is, for example, 10 or less, preferably 9 or less, and more preferably 8 or less. An appropriate specific gravity is preferable in terms of the dispersibility of the silver-coated resin particles themselves and the uniformity when silver-coated resin particles are used in combination with other silver-containing particles.

[0036] When using silver-coated resin particles, the proportion of silver-coated resin particles in the total silver-containing particles is preferably 1 to 50% by mass, more preferably 3 to 45% by mass, and even more preferably 5 to 40% by mass. By appropriately adjusting this proportion, it is possible to further improve heat dissipation while suppressing the decrease in adhesive strength due to heat cycling.

[0037] Incidentally, if the proportion of silver-coated resin particles in the total silver-containing particles is not 100% by mass, then the silver-containing particles other than the silver-coated resin particles are, for example, particles that consist substantially of only silver.

[0038] Median diameter D of silver-containing particles 50 The particle size is, for example, 0.01 to 50 μm, preferably 0.1 to 20 μm, and more preferably 0.5 to 10 μm. 50By setting it to an appropriate value, it is easy to achieve a balance among thermal conductivity, sinterability, resistance to heat cycles, etc. Also, D 50 By setting it to an appropriate value, it may be possible to improve the workability of coating / adhesion. The particle size distribution of the silver-containing particles (horizontal axis: particle diameter, vertical axis: frequency) may be unimodal or multimodal.

[0039] From the perspective of the effects of the present invention, it is preferable that the silver-containing particles include spherical silver-containing particles 1 and flaky silver-containing particles 2-1. It is more preferable that these silver-containing particles are silver particles consisting essentially of only silver.

[0040] The median diameter D of the spherical silver-containing particles 1 50 is, for example, 0.1 to 20 μm, preferably 0.5 to 10 μm, more preferably 0.5 to 5.0 μm. The specific surface area of the spherical silver-containing particles 1 is, for example, 0.1 to 2.5 m 2 / g, preferably 0.5 to 2.3 m 2 / g, more preferably 0.8 to 2.0 m 2 / g. The tap density of the spherical silver-containing particles 1 is, for example, 1.5 to 6.0 g / cm 3 , preferably 2.5 to 5.8 g / cm 3 , more preferably 4.5 to 5.5 g / cm 3 . The circularity of the spherical silver-containing particles 1 is, for example, 0.90 or more, preferably 0.92 or more, more preferably 0.94 or more. By satisfying these respective characteristics, it is excellent in the balance among thermal conductivity, sinterability, resistance to heat cycles, etc.

[0041] The median diameter D of the flaky silver-containing particles 2-1 50 is, for example, 0.1 to 20 μm, preferably 1.0 to 15 μm, more preferably 2.0 to 10 μm. The specific surface area of the flaky silver-containing particles​​​​2 It is / g. The tap density of the flaky silver-containing particles 2-1 is, for example, 1.5 to 6.0 g / cm³. 3 Preferably 2.5 to 5.9 g / cm³ 3 , more preferably 4.0 to 5.8 g / cm³ 3 That is the case. By satisfying these characteristics, it achieves an excellent balance of thermal conductivity, sinterability, and resistance to heat cycling.

[0042] In this embodiment, by combining spherical silver-containing particles 1 that satisfy at least one of the above characteristics with flaky silver-containing particles 2-1 that satisfy at least one of the above characteristics, thermal conductivity and electrical conductivity are particularly improved.

[0043] The ratio (1 / 2-1) of the content of spherical silver-containing particles 1 to the content of flaky silver-containing particles 2-1 is preferably 0.1 to 10, more preferably 0.3 to 5, and particularly preferably 0.5 to 3. This significantly improves the contact rate between the silver-containing particles, allowing a network to be easily formed after sintering of the paste-like polymerizable composition, thereby significantly improving thermal and electrical conductivity.

[0044] Median diameter D of flaky silver-containing particles 2-1 50 Median diameter D of spherical silver-containing particle 1 relative to 50 The ratio (1 / 2-1) is preferably 0.01 or more and 0.8 or less, more preferably 0.05 or more and 0.6 or less. As a result, spherical silver-containing particles efficiently fill the gaps between the flaky silver-containing particles, and the contact rate between the silver-containing particles is particularly improved. This allows a network to be easily formed in the paste-like polymerizable composition after sintering, resulting in particularly improved thermal and electrical conductivity.

[0045] The ratio (1 / 2-1) of the tap density of spherical silver-containing particles 1 to the tap density of flake-shaped silver-containing particles 2-1 is preferably 0.5 or more and 2.0 or less, more preferably 0.7 or more and 1.2 or less. As a result, the packing density of silver-containing particles is improved, and the contact rate between silver-containing particles is particularly improved. This allows a network to be easily formed in the paste-like polymerizable composition after sintering, resulting in particularly improved thermal and electrical conductivity.

[0046] Median diameter D of silver-coated resin particles 50 The thickness is, for example, 5.0 to 25 μm, preferably 7.0 to 20 μm, and more preferably 8.0 to 15 μm. This can further improve thermal conductivity.

[0047] Median diameter D of silver-containing particles 50 This can be determined, for example, by performing particle image measurement using the FPIA(registered trademark)-3000 flow-type particle image analyzer manufactured by Sysmex Corporation. More specifically, the particle size of silver-containing particles can be determined by measuring the volume-based median diameter using this instrument in a wet manner.

[0048] Among silver-containing particles, those consisting substantially of only silver can be obtained from companies such as DOWA High-Tech Co., Ltd. and Fukuda Metal Foil & Powder Industry Co., Ltd. Silver-coated resin particles can be obtained from companies such as Mitsubishi Materials Corporation, Sekisui Chemical Co., Ltd., and Sanno Co., Ltd.

[0049] The content of conductive particles (A) in the total nonvolatile components of the conductive resin composition is preferably 40 to 95% by mass, more preferably 50 to 93% by mass, and even more preferably 60 to 90% by mass. Increasing the amount of conductive particles added lowers the volume resistivity and improves thermal conductivity, but it can also increase the storage modulus, leading to a decrease in product reliability. In other words, there was a trade-off between improved thermal conductivity and product reliability. The inventors have found that even when a large amount of conductive particles are added, by adding a polymer (B) containing polyrotaxane, as described later, both the volume resistivity and storage modulus become low, resulting in excellent thermal conductivity and product reliability, as well as excellent adhesion to substrates due to the shock absorption ability of the polyrotaxane. In other words, the conductive resin composition of this embodiment exhibits excellent thermal conductivity and product reliability, as well as excellent adhesion to substrates, even when a large amount of conductive particles are added.

[0050] [Polymer (B)] The polymer (B) of this embodiment contains a polyrotaxane. Polyrotaxanes typically comprise a cyclic molecule forming an opening, a linear molecular chain penetrating the opening of the cyclic molecule, and a chokehold group attached to each end of the linear molecular chain. The chokehold group prevents the cyclic molecule from detaching from the linear molecular chain. A single linear molecular chain can penetrate the openings of one or more cyclic molecules.

[0051] The cyclic molecules in the polyrotaxane are not particularly limited, as long as they form an opening through which linear molecular chains can pass. The cyclic molecules do not need to be completely ring-closed by covalent bonds, as long as the linear molecular chains passing through the opening do not detach.

[0052] Examples of cyclic molecules include cyclodextrins, crown ethers, benzocrowns, dibenzocrowns, dicyclohexanocrowns, and their derivatives or modified forms. From the viewpoint of inclusion ability of linear molecular chains, the cyclic molecule is preferably a cyclodextrin or its derivative or modified form.

[0053] When the cyclic molecule is a cyclodextrin or a derivative or modified version thereof, it is preferable that some or all of the hydroxyl groups in the cyclodextrin are substituted with hydrophobic groups. Substitution of hydroxyl groups with hydrophobic groups improves the solubility of the polyrotaxane in organic solvents.

[0054] When a cyclic molecule is penetrated by a linear molecular chain, if the maximum amount of cyclic molecules encapsulated by the linear molecular chain is defined as 1, the lower limit of the relative amount (molar ratio) of encapsulated cyclic molecules is, for example, 0.001, preferably 0.01, more preferably 0.1 or higher, and the upper limit is, for example, 0.7 or lower, preferably 0.6 or lower, more preferably 0.5 or lower. By keeping the amount of cyclic molecules encapsulated within the above range, the mobility of the cyclic molecules on the linear molecular chain is easily maintained.

[0055] The linear molecular chains in polyrotaxanes are not particularly limited, as long as they can penetrate the cyclic molecules and the cyclic molecules are mobile on the linear molecular chains. The linear molecular chains only need to contain substantially linear portions; they may also have branched chains or cyclic substituents. The length and molecular weight of the linear portions are not particularly limited.

[0056] Examples of linear molecular chains include alkylene chains, polyester chains, polyether chains, polyamide chains, and polyacrylate chains. Among these, polyester chains or polyether chains are preferred, and polyether chains are more preferred, from the viewpoint of the flexibility of the linear molecular chain itself. As polyether chains, polyethylene glycol chains (polyoxyethylene chains) can be given as examples.

[0057] The choke-off groups in polyrotaxanes are not particularly limited, as long as they are positioned at both ends of a linear molecular chain and are capable of maintaining the state in which the linear molecular chain penetrates the cyclic molecule.

[0058] Examples of chelating groups include groups with a structure larger than the opening of a cyclic molecule, and groups that cannot pass through the opening of a cyclic molecule due to ionic interactions. Specifically, examples of chelating groups include adamantyl groups, groups containing cyclodextrins, anthracene groups, triphenylene groups, pyrene groups, trityl groups, and their isomers and derivatives.

[0059] In polyrotaxanes, the combination of a cyclic molecule and a linear molecular chain is preferably a combination of α-cyclodextrin or a derivative thereof as the cyclic molecule and polyethylene glycol chain or a derivative thereof as the linear molecular chain. This combination facilitates the movement of the cyclic molecule along the linear molecular chain. This combination also has the advantage of being relatively easy to synthesize.

[0060] The polyrotaxane preferably has crosslinkable groups. The presence of crosslinkable groups in the polyrotaxane improves the thermosetting properties and adhesive properties of the conductive resin composition. When the polyrotaxane has crosslinking groups, it is preferable that the cyclic molecules within the polyrotaxane also have crosslinking groups. Having crosslinking groups in the cyclic molecules ensures that even after the composition is heat-cured (crosslinked), the cyclic molecules remain able to slide along the linear molecular chains. Therefore, the flexibility and elongation of the heat-cured film can be further enhanced.

[0061] The crosslinkable group is preferably a cationic crosslinkable group or a radical crosslinkable group, and more preferably a radical crosslinkable group. The crosslinkable group is preferably an ethylenically active carbon-carbon double bond-containing group such as a (meth)acryloyl group. In a different embodiment from the (meth)acryloyl group, the crosslinkable group may include an epoxy group and / or an oxetanyl group.

[0062] Polyrotaxanes may be synthesized using known methods or may be commercially available. A commercially available example is the "SeRM" series (registered trademark) sold by ASM Co., Ltd.

[0063] The conductive resin composition of this embodiment may contain only one type of polyrotaxane, or it may contain two or more types.

[0064] Polymer (B) may include known resins other than polyrotaxanes, to the extent that it achieves the effects of the present invention. Examples of such resins include silicone resins, (meth)acrylic resins, phenolic resins, polystyrene resins, melamine resins, polyamide resins, and polytetrafluoroethylene resins.

[0065] In this embodiment, the content of the polyrotaxane in 100% by mass of polymer (B) is 75% to 100% by mass, preferably 80% to 100% by mass, more preferably 90% to 100% by mass, and particularly preferably 95% to 100% by mass. By including polyrotaxane in the above amount in polymer (B), the thermal conductivity and storage modulus are further improved, as is the adhesion to the substrate.

[0066] [Monomer (C)] The monomer (C) includes a compound having a double bond at its terminus. The number of double bonds is one or more. The conductive resin composition of this embodiment, by including a polyrotaxane and the compound having a double bond at its terminus, exhibits excellent thermal conductivity and storage modulus, as well as excellent adhesion to substrates and the like.

[0067] The monomer (C) comprises at least one selected from (meth)acrylic compounds, diallyl ether compounds, vinyl ether compounds, (bis)maleimide compounds, (meth)allyl compounds, and vinyl compounds.

[0068] The (meth)acrylic compound is not particularly limited, but examples include monofunctional or difunctional (meth)acrylic compounds, or trifunctional or polyfunctional (meth)acrylic compounds. In this embodiment, (meth)acrylic compound refers to an acrylic compound, a methacrylic compound, or a mixture thereof, and having a (meth)acrylic group means having one or more acrylic groups or one or more methacrylic groups.

[0069] In this embodiment, monofunctional (meth)acrylates include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, butoxyethyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octylheptyl (meth)acrylate, nonyl (meth)acrylate, decyl ( Aliphatic (meth)acrylates such as meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, stearyl (meth)acrylate, behenyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and phenoxypolyethylene glycol (meth)acrylate; Alicyclic (meth)acrylates such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, cyclopentyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, 3-methyl-3-oxetanylmethyl (meth)acrylate, and 1-adamantyl (meth)acrylate; Aromatic (meth)acrylates such as phenyl(meth)acrylate, nonylphenyl(meth)acrylate, p-cumylphenyl(meth)acrylate, o-biphenyl(meth)acrylate, 1-naphthyl(meth)acrylate, 2-naphthyl(meth)acrylate, benzyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, 2-hydroxy-3-(o-phenylphenoxy)propyl(meth)acrylate, 2-hydroxy-3-(1-naphthoxy)propyl(meth)acrylate, and 2-hydroxy-3-(2-naphthoxy)propyl(meth)acrylate; Examples of heterocyclic (meth)acrylates include 2-tetrahydrofurfuryl (meth)acrylate, N-(meth)acryloyloxyethyl hexahydrophthalimide, and 2-(meth)acryloyloxyethyl-N-carbazole.

[0070] Furthermore, examples of difunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and 1,3-butanediol di(meth)acrylate. Aliphatic (meth)acrylates such as phosphate, 2-methyl-1,3-propanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, glycerin di(meth)acrylate, and tricyclodecanedimethanol (meth)acrylate; Alicyclic (meth)acrylates such as cyclohexanedimethanol (meth)acrylate, tricyclodecanedimethanol (meth)acrylate, hydrogenated bisphenol A di(meth)acrylate, and hydrogenated bisphenol F di(meth)acrylate; Aromatic (meth)acrylates such as bisphenol A di(meth)acrylate, bisphenol F di(meth)acrylate, bisphenol AF di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, and fluorene-type di(meth)acrylate; Examples include heterocyclic (meth)acrylates such as isocyanuric acid di(meth)acrylate.

[0071] Examples of polyfunctional (meth)acrylates with three or more functions include aliphatic (meth)acrylates such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and ethoxylated glycerin tri(meth)acrylate; and heterocyclic (meth)acrylates such as isocyanuric acid tri(meth)acrylate. The (meth)acrylic compound may include at least one selected from these, and may include monofunctional (meth)acrylate or difunctional (meth)acrylate.

[0072] Examples of diallyl ether compounds include diallyl ether, glycerin diallyl ether, diethylene glycol diallyl ether, ethylene glycol diallyl ether, triethylene glycol diallyl ether, polyethylene glycol diallyl ether, trimethylolpropane diallyl ether, pentaerythritol diallyl ether, bisphenol diallyl ether, and 2,2-bis(4-hydroxycyclohexyl)propane diallyl ether. The diallyl ether compound may include at least one selected from these.

[0073] Examples of vinyl ether compounds include diethylene glycol monovinyl ether, triethylene glycol divinyl ether, n-dodecyl vinyl ether, cyclohexyl vinyl ether, 2-ethylhexyl vinyl ether, 2-chloroethyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, triethylene glycol vinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 1,6-cyclohexanedimethanol monovinyl ether, ethylene glycol divinyl ether, 1,4-butanediol divinyl ether, and 1,6-cyclohexanedimethanol divinyl ether. The vinyl ether compound may include at least one selected from these.

[0074] Examples of (bis)maleimide compounds include tetramethylene(bis)maleimide, hexamethylene(bis)maleimide, (bis)maleimidebenzene, (bis)maleimidecumylbenzene, (bis)maleimidediphenyl ether, (bis)maleimidediphenylmethane, (bis)maleimide-3,3'-dimethyl-diphenylmethane, (bis)maleimidediphenylsulfone, (bis)maleimidediphenyl sulfide, (bis)maleimidediphenyl ketone, (bis)maleimidephenylpropane, (bis)maleimidediphenylfluoromethane, and 1,1,1,3,3,3-hexafluoro-(bis)maleimidephenylpropane, bisphenol A(bis)maleimidephenyl ether, etc. (Bis)maleimide compounds may include at least one selected from these.

[0075] The (meth)allyl compound is not particularly limited, but examples include monofunctional or difunctional (meth)allyl compounds, or polyfunctional (meth)allyl compounds with three or more functions. In this embodiment, (meth)allyl compound refers to an allyl compound, a metaallyl compound, or a mixture thereof, and having a (meth)allyl group means having one or more allyl groups or one or more metaallyl groups.

[0076] Examples of monofunctional (meth)allyl compounds include (meth)allyl acetate, (meth)allyl n-propionate, (meth)allyl benzoate, (meth)allyl phenyl acetate, (meth)allyl phenoxyacetate, (meth)allyl methyl ether, (meth)allyl glycidyl ether, and (meth)allyloxymethyl methyl acrylate.

[0077] Examples of polyfunctional (meth)allyl compounds include benzenedicarboxylic acid di(meth)allyl, cyclohexanedicarboxylic acid di(meth)allyl, di(meth)allyl maleate, di(meth)allyl adipate, di(meth)allyl phthalate, di(meth)allyl isophthalate, di(meth)allyl terephthalate, glycerin di(meth)allyl ether, trimethylolpropane di(meth)allyl ether, pentaerythritol di(meth)allyl ether, 1,3 Examples include -di(meth)allyl-5-glycidyl isocyanurate, tri(meth)allyl cyanurate, tri(meth)allyl isocyanurate, tri(meth)allyl trimellitate, tetra(meth)allyl pyromelitate, 1,3,4,6-tetra(meth)allyl glycoluryl, 1,3,4,6-tetra(meth)allyl-3a-methyl glycoluryl, and 1,3,4,6-tetra(meth)allyl-3a,6a-dimethyl glycoluryl. (Meth)allyl compounds may include at least one selected from these.

[0078] Examples of vinyl compounds include styrene, hydroxystyrene, alkoxystyrene, vinylnaphthalene, vinylanthracene, and vinylcarbazole, and the compound may contain at least one selected from these.

[0079] In this embodiment, from the viewpoint of the effects of the present invention, it is preferable that the monomer (C) contains a (meth)acrylic compound.

[0080] The monomer (C) of this embodiment may include monomers other than those having a double bond at the terminal end, as long as the effects of the present invention are achieved. Examples of such monomers include epoxy compounds, thiol compounds, carbonyl compounds, and aromatic compounds.

[0081] In this embodiment, the content of the compound having a terminal double bond in 100% by mass of monomer (C) is 80% to 100% by mass, preferably 90% to 100% by mass, and more preferably 95% to 100% by mass. This results in even better thermal conductivity and storage modulus, as well as better adhesion to substrates and the like.

[0082] [Radical initiator (D)] The conductive resin composition of this embodiment may contain a radical initiator (D). Radical initiators (D) can, for example, prevent insufficient curing, allow curing reactions to proceed sufficiently at relatively low temperatures (e.g., 180°C), and further improve adhesive strength. Examples of radical initiators (D) include peroxides and azo compounds.

[0083] Examples of peroxides include organic peroxides such as diacyl peroxides, dialkyl peroxides, and peroxyketals. More specifically, these include ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; and peroxyketals such as 1,1-di(t-butylperoxy)cyclohexane and 2,2-di(4,4-di(t-butylperoxy)cyclohexyl)propane. Hydroperoxides such as p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, and t-butyl hydroperoxide; Dialkyl peroxides such as di(2-t-butylperoxyisopropyl)benzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylcumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexine-3, and di-t-butyl peroxide; Diacyl peroxides such as dibenzoyl peroxide and di(4-methylbenzoyl) peroxide; Peroxydicarbonates such as di-n-propyl peroxydicarbonate and diisopropyl peroxydicarbonate; Examples of peroxy esters include 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-hexylperoxybenzoate, t-butylperoxybenzoate, and t-butylperoxy2-ethylhexanonate.

[0084] Examples of azo compounds include 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile). When using radical initiators, one type may be used alone, or two or more types may be used in combination.

[0085] If the conductive resin composition of this embodiment contains a radical initiator (D), the amount thereof is, for example, 0.1 to 20 parts by mass, preferably 0.5 to 15 parts by mass, when the amount of the thermosetting component is 100 parts by mass.

[0086] [Other ingredients] The conductive resin composition of this embodiment may also contain other components such as a curing agent, a curing accelerator, a silane coupling agent, a plasticizer, and an adhesion promoter. The inclusion of a silane coupling agent further improves adhesive strength, and the inclusion of a plasticizer lowers the storage modulus. This also makes it easier to suppress the decrease in adhesive strength due to heat cycling.

[0087] <Conductive resin composition> The conductive resin composition of this embodiment is preferably in paste form at 20°C. That is, the conductive resin composition of this embodiment can preferably be applied to a substrate or the like like an adhesive at 20°C. As a result, the conductive resin composition of this embodiment can be preferably used as an adhesive for semiconductor devices and the like. Of course, depending on the process to which it is applied, the conductive resin composition of this embodiment may be a relatively low-viscosity varnish or the like.

[0088] The conductive resin composition of this embodiment can be obtained by mixing the above-mentioned components and, if necessary, other components, using conventionally known methods.

[0089] <High thermal conductivity materials> A highly thermally conductive material can be obtained by sintering the conductive resin composition of this embodiment. By changing the shape of high thermal conductivity materials, they can be applied to various components in the automotive and electrical fields that require heat dissipation.

[0090] <Semiconductor device> A semiconductor device can be manufactured using the conductive resin composition of this embodiment. For example, a semiconductor device can be manufactured by using the conductive resin composition of this embodiment as an "adhesive" between a substrate and a semiconductor element.

[0091] In other words, the semiconductor device of this embodiment comprises, for example, a substrate and a semiconductor element mounted on the substrate via an adhesive layer obtained by sintering the above-mentioned conductive resin composition by heat treatment. The semiconductor device of this embodiment is less susceptible to deterioration of the adhesion of the adhesive layer even under heat cycling. In other words, the semiconductor device of this embodiment has high reliability. Examples of semiconductor devices include ICs, LSIs, power semiconductor devices, and various other types of devices. Examples of substrates include various semiconductor wafers, lead frames, BGA substrates, mounted substrates, heat spreaders, and heat sinks.

[0092] An example of a semiconductor device will be described below with reference to the drawings. Figure 1 is a cross-sectional view showing an example of a semiconductor device. The semiconductor device 100 comprises a substrate 30 and a semiconductor element 20 mounted on the substrate 30 via an adhesive layer 10 (die attach material) which is a heat-treated conductive resin composition.

[0093] The semiconductor element 20 and the substrate 30 are electrically connected, for example, via bonding wires 40. The semiconductor element 20 is also sealed, for example, with a sealing resin 50.

[0094] The thickness of the adhesive layer 10 is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. This improves the stress absorption capacity of the conductive resin composition and enhances its heat cycle resistance. The thickness of the adhesive layer 10 is, for example, 100 μm or less, preferably 50 μm or less.

[0095] In Figure 1, the substrate 30 is, for example, a lead frame. In this case, the semiconductor element 20 is mounted on the die pad 32 or the substrate 30 via an adhesive layer 10. The semiconductor element 20 is also electrically connected to the outer lead 34 (substrate 30) via, for example, a bonding wire 40. The substrate 30, which is the lead frame, is made of, for example, a 42 alloy, a Cu frame, etc.

[0096] The substrate 30 may be an organic substrate or a ceramic substrate. Examples of organic substrates include those made of epoxy resin, cyanate resin, maleimide resin, etc. The surface of the substrate 30 may be coated with a metal such as silver or gold. This improves the adhesion between the adhesive layer 10 and the substrate 30.

[0097] Figure 2 is a cross-sectional view showing an example of a semiconductor device 100 different from that in Figure 1. In the semiconductor device 100 shown in Figure 2, the substrate 30 is, for example, an interposer. On the substrate 30, which is an interposer, a plurality of solder balls 52 are formed on the side opposite to the side on which the semiconductor element 20 is mounted. In this case, the semiconductor device 100 is connected to other wiring boards via the solder balls 52.

[0098] An example of a semiconductor device manufacturing method will be described. First, a conductive resin composition is applied to the substrate 30, and then the semiconductor element 20 is placed on top of it. In other words, the substrate 30, the conductive resin composition, and the semiconductor element 20 are layered in this order. The method for coating the conductive resin composition is not particularly limited. Specifically, examples include dispensing, printing, and inkjet methods.

[0099] Next, the conductive resin composition is heat-cured. Heat curing is preferably performed by pre-curing and post-curing. Heat curing makes the conductive resin composition a heat-treated body (cured product). Heat curing (heat treatment) causes the metal-containing particles in the conductive resin composition to aggregate, and a structure is formed in the adhesive layer 10 in which the interfaces between multiple metal-containing particles disappear. As a result, the substrate 30 and the semiconductor element 20 are bonded together via the adhesive layer 10. Next, the semiconductor element 20 and the substrate 30 are electrically connected using bonding wires 40. Then, the semiconductor element 20 is sealed with sealing resin 50. In this way, a semiconductor device can be manufactured.

[0100] Although embodiments of the present invention have been described above, these are merely examples, and various other configurations can be adopted. Furthermore, the present invention is not limited to the embodiments described above, and modifications, improvements, etc., within the scope that can achieve the objectives of the present invention are included in the present invention. Examples of reference formats are provided below. 1. (A) Conductive particles and (B) A polymer containing polyrotaxane, A monomer containing a compound having a double bond at the (C) terminus, Includes, A conductive resin composition in which the ratio of monomer (C) to polymer (B) is 50-95% by mass in a total of 100% by mass of monomer (C). 2. The conductive resin composition according to 1., wherein the content of the polyrotaxane in 100% by mass of polymer (B) is 75 to 100% by mass. 3. The conductive resin composition according to 1. or 2., wherein monomer (C) comprises at least one selected from (meth)acrylic compounds, diallyl ether compounds, vinyl ether compounds, (bis)maleimide compounds, (meth)allyl compounds, and vinyl compounds. 4. The conductive resin composition according to any one of 1 to 3, wherein the polyrotaxane has a crosslinking group. 5. The conductive resin composition according to 4, wherein the crosslinkable group comprises a (meth)acryloyl group. 6. The conductive resin composition according to 4. or 5., wherein the cyclic molecule constituting the polyrotaxane has the crosslinkable group. 7. The conductive resin composition according to any one of 1. to 6., wherein the conductive particles (A) include silver-containing particles. 8. The conductive resin composition according to 7, wherein the silver-containing particles include two or more types selected from spherical, dendritic, string-like, flake-like, aggregated, and polyhedral silver-containing particles. 9. The conductive resin composition according to any one of 1 to 8, wherein the content of conductive particles (A) in the total nonvolatile components of the conductive resin composition is 40 to 95% by mass. 10. A conductive resin composition according to any one of 1 to 9, further comprising a radical initiator (D). 11. A conductive resin composition according to any one of 1. to 10., which is in paste form at 20℃. 12. A highly thermally conductive material obtained by sintering a conductive resin composition described in any of 1. to 11. 13. Substrate and The system comprises a semiconductor element mounted on the substrate via an adhesive layer, The adhesive layer is a semiconductor device obtained by sintering a conductive resin composition according to any one of 1. to 11. [Examples]

[0101] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

[0102] [Examples 1-7, Comparative Example 1] The raw materials were mixed according to the proportions shown in Table 1 to obtain the varnish. Next, the obtained varnish was mixed according to the proportions shown in Table 1 and kneaded at room temperature using a three-roll mill. This produced a conductive resin composition.

[0103] (polymer) • Polymer Solution 1: SA1305P-20: A 50% by mass solution of ethyl acetate containing polyrotaxane, sold by ASM Co., Ltd. The cyclic molecules in the polyrotaxane contain acryloyl groups. Overall weight-average molecular weight (typical value): 1,000,000, Methacrylic equivalent (typical value): 1500 g / eq • Polymer 2: Bisphenol F type epoxy resin (RE-303S, manufactured by Nippon Kayaku Co., Ltd.)

[0104] (Hardening agent) • Hardener 1: Phenolic resin having a bisphenol F skeleton (DIC Corporation, DIC-BPF)

[0105] (monomer) • Monomer 1: 1,4-Cyclohexanedimethanol monoacrylate (manufactured by Nippon Chemical Industries, Ltd., CHDMMA) • Monomer 2: Ethylene glycol dimethacrylate (manufactured by Kyoei Chemical Co., Ltd., Light Ester EG) • Monomer 3:2-[(allyloxy)methyl]methyl acrylate (manufactured by Nippon Shokubai Co., Ltd., AOMA) • Monomer 4: Cyclohexyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0106] (Curing accelerator) • Curing accelerator 1: 2-phenyl-1H-imidazole 4,5-dimethanol (manufactured by Shikoku Chemicals Co., Ltd., Cureazole 2PHZ-PW)

[0107] (Radical initiator) • Radical initiator 1: Dicumyl peroxide (manufactured by Kayaku Akzo, Percadox BC) • Radical initiator 2: Di-t-butyl peroxide (manufactured by Nippon Oil & Fats Co., Ltd., Perbutyl D)

[0108] (Conductive particles) • Silver filler 1: DOWA Electronics Co., Ltd., AG-DSB-114, spherical, D 50 :0.7μm, specific surface area: 1.05m 2 / g, tap density 5.25g / cm³ 3 Circularity: 0.953 • Silver filler 2: Manufactured by Fukuda Metal Foil Powder Industry Co., Ltd., HKD-12, flake-like, median diameter D 50 :7.6μm, specific surface area: 0.315m 2 / g, tap density: 5.5g / cm³ 3 • Silver filler 3: Manufactured by Fukuda Metal Foil Powder Industry Co., Ltd., HKD-16, flake-like, median diameter D 50 :2.0μm, specific surface area: 1.05m 2 / g, tap density: 4.0g / cm³ 3

[0109] (solvent) Solvent 1: Tripropylene glycol mono-n-butyl ether (BFTG, manufactured by Nippon Emulsifier Co., Ltd., boiling point 274°C)

[0110] The following physical properties were measured using the obtained conductive resin composition. (Volume resistivity) A conductive resin composition was applied to a glass plate and heated under a nitrogen atmosphere from 30°C to 200°C over 60 minutes, followed by heat treatment at 200°C for 120 minutes. This yielded a heat-treated body (cured product) of the conductive resin composition with a thickness of 0.05 mm. The resistance value of the surface of the heat-treated body was measured using a four-electrode DC method with electrodes spaced 40 mm apart, using a milliohmmeter (manufactured by HIOKI).

[0111] (Storage modulus) A heat-treated conductive resin composition was cut into strips approximately 0.1 mm × 10 mm × 4 mm in size to obtain evaluation strips. The storage modulus (E') at 25°C was measured using DMA (dynamic viscoelasticity measurement, tensile mode) under conditions of a heating rate of 5°C / min and a frequency of 10 Hz.

[0112] (Die share strength) A conductive resin composition was applied to a Cu lead frame, and an Au-coated 7mm square Si chip was mounted on top of it so that the thickness after heat treatment was approximately 50 μm. The temperature was increased from 30°C to 200°C over 60 minutes under a nitrogen atmosphere, followed by heat treatment at 200°C for 120 minutes. The resulting sample was stored in a constant temperature and humidity chamber at 60°C / 60%RH for 48 hours. After storage, the sample was placed on a hot plate at 260°C, and the die shear strength at 500 μm / sec was measured after 20 seconds.

[0113] [Table 1]

[0114] The results shown in Table 1 reveal that cured products obtained from conductive resin compositions containing polyrotaxane and a predetermined amount of monomer exhibit low volume resistivity and storage modulus, as well as excellent adhesion to semiconductor devices and substrates. [Explanation of symbols]

[0115] 100 Semiconductor Equipment 10 Adhesive layer 20 Semiconductor elements 30 Base material 32 die pads 34 Outer lead 40 Bonding Wires 50 Sealing resin 52 Solder ball

Claims

1. (A) Conductive particles and (B) A polymer containing polyrotaxane, (C) A monomer containing a compound having a double bond at its terminus, A conductive resin composition comprising, The ratio of monomer (C) in the total 100% by mass of polymer (B) and monomer (C) is 50 to 95% by mass. A conductive resin composition wherein the content of conductive particles (A) in the total nonvolatile components of the conductive resin composition is 40 to 95% by mass.

2. The conductive resin composition according to claim 1, wherein the content of the polyrotaxane in 100% by mass of polymer (B) is 75 to 100% by mass.

3. The conductive resin composition according to claim 1 or 2, wherein the monomer (C) comprises at least one selected from (bis)maleimide compounds and vinyl compounds.

4. The conductive resin composition according to any one of claims 1 to 3, wherein the polyrotaxane has a crosslinking group.

5. The conductive resin composition according to claim 4, wherein the crosslinkable group comprises a (meth)acryloyl group.

6. The conductive resin composition according to claim 4 or 5, wherein the cyclic molecule constituting the polyrotaxane has the crosslinkable group.

7. The conductive resin composition according to any one of claims 1 to 6, wherein the conductive particles (A) include silver-containing particles.

8. The conductive resin composition according to claim 7, wherein the silver-containing particles include two or more types selected from spherical, dendritic, string-like, flaky, aggregated, and polyhedral silver-containing particles.

9. The conductive resin composition according to any one of claims 1 to 8, further comprising a radical initiator (D).

10. A conductive resin composition according to any one of claims 1 to 9, which is in a paste-like state at 20°C.

11. A highly thermally conductive material obtained by sintering a conductive resin composition according to any one of claims 1 to 10.

12. Substrate and The system comprises a semiconductor element mounted on the substrate via an adhesive layer, The adhesive layer is a semiconductor device obtained by sintering a conductive resin composition according to any one of claims 1 to 10.

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