Semiconductor package, method for manufacturing semiconductor package, and thermally conductive composition therefor

Abstract

The invention provides a semiconductor package, a method for manufacturing the semiconductor package, and a thermally conductive composition for the semiconductor package. The semiconductor package includes a substrate, a semiconductor element provided on the substrate, and a heat sink surrounding the periphery of the semiconductor element, and the semiconductor element and the heat sink are bonded by a thermally conductive material having a particle connection structure in which metal particles are sintered by heat treatment.

Description

[0001] This case is filed on March 11, 2020 、Application No. 202080023193.6 、The name of the invention is Semiconductor Sealing Package, method for manufacturing semiconductor package, and thermally conductive composition therefor A divisional application for a patent application. Technical Field

[0002] The present invention relates to a semiconductor package, a method for manufacturing the semiconductor package, and a thermally conductive composition used therefor. Background Art

[0003] Various developments have been made in semiconductor packages having a thermal conductor. As such a technology, for example, the technology described in Patent Document 1 is known.

[0004] Patent document 1 describes a semiconductor package in which a semiconductor element (heat generating element) mounted on an electronic circuit board and a heat sink are bonded together via a thermally conductive double-sided tape (a thermally conductive material composed of an adhesive) (Example 7 of Patent document 1, FIG. 16 ).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2015 / 072428 Summary of the invention

[0008] Technical problem to be solved by the invention

[0009] However, as a result of the present inventors' studies, it has become clear that the semiconductor package described in Patent Document 1 has room for improvement in terms of heat dissipation characteristics.

[0010] Means for solving technical problems

[0011] Currently, as the performance of semiconductor elements (heat generating elements) increases, the amount of heat generated increases, and thus semiconductor packages are required to have a more advanced improvement in heat dissipation characteristics.

[0012] As a result of studies under such circumstances, it was found that even if a thermoplastic gel in which an acrylic adhesive, boron nitride, aluminum oxide or zinc oxide is dispersed is used as a thermally conductive material for bonding semiconductor elements and heat dissipating parts such as heat spreaders, sufficient thermal conductivity cannot be obtained.

[0013] As a result of further research by the inventors, it was found that by using a thermally conductive material having a particle connection structure formed by sintering metal particles through heat treatment as the thermally conductive material, the thermal conductivity of the thermally conductive material can be improved, and semiconductor elements and heat dissipation components can be joined, thereby improving the heat dissipation characteristics in the semiconductor package, thereby completing the present invention.

[0014] According to the present invention, there is provided a semiconductor package, which includes a substrate, a semiconductor element arranged on the substrate, and a heat spreader surrounding the semiconductor element, wherein the semiconductor element and the heat spreader are joined by a thermally conductive material, and the semiconductor package is characterized in that the thermally conductive material has a particle connection structure formed by sintering metal particles through heat treatment.

[0015] Furthermore, according to the present invention, there is provided a thermally conductive composition for forming a thermally conductive material in a semiconductor package, wherein the semiconductor package includes a substrate, a semiconductor element disposed on the substrate, and a heat sink surrounding the semiconductor element, wherein the semiconductor element and the heat sink are bonded by the thermally conductive material, wherein the thermally conductive composition contains: metal particles; a binder resin; and a monomer, wherein the metal particles are sintered by heat treatment to form a particle connection structure.

[0016] Furthermore, according to the present invention, there is provided a method for manufacturing a semiconductor package, comprising: a step of arranging a semiconductor element on one surface of a substrate so that the other surface of the semiconductor element faces one surface of the substrate; a step of applying a thermally conductive composition containing metal particles on a surface of one surface of the semiconductor element; a step of arranging a heat sink so as to be in contact with the thermally conductive composition and cover at least one surface of the semiconductor element; and a step of heat-treating a structure including the substrate, the semiconductor element, the thermally conductive composition and the heat sink, wherein in the step of heat-treating, the semiconductor element and the heat sink are bonded via a thermally conductive material having a particle connection structure formed by sintering of the metal particles.

[0017] Effects of the Invention

[0018] According to the present invention, it is possible to provide a semiconductor package having excellent heat dissipation characteristics, a method for manufacturing the semiconductor package, and a thermally conductive composition used therefor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above-mentioned objects and other objects, features and advantages will become more apparent from the preferred embodiments described below and the following drawings attached thereto.

[0020] Figure 1It is a cross-sectional view schematically showing an example of the semiconductor package according to the present embodiment.

[0021] Figure 2 This is a SEM image showing a cross section of the particle interconnection structure of Example 1. DETAILED DESCRIPTION

[0022] The following is a description of the embodiments of the present invention using the accompanying drawings. In addition, in all the drawings, the same components are marked with the same symbols, and the description is appropriately omitted. In addition, the drawings are schematic diagrams and are not consistent with the actual size ratio.

[0023] The outline of the semiconductor package according to the present embodiment will be described.

[0024] Figure 1 This is a cross-sectional view schematically showing an example of a semiconductor package according to the present embodiment.

[0025] The semiconductor package 100 of this embodiment includes a substrate 10 , a semiconductor element 20 , a heat sink 30 , and a thermally conductive material 50 . The semiconductor element 20 is disposed on the substrate 10 , the heat sink 30 surrounds the semiconductor element 20 , and the thermally conductive material 50 bonds the semiconductor element 20 and the heat sink 30 .

[0026] In the semiconductor package 100 , the thermally conductive material 50 has a particle connection structure formed by sintering metal particles through heat treatment.

[0027] The particle connection structure in the thermally conductive material 50 can be observed by using a scanning electron microscope or other microscopes to observe at least one cross section of the thermally conductive material 50 cut along the stacking direction of the semiconductor element 20 and the heat sink 30 .

[0028] In a predetermined region of the cross section of the thermally conductive material 50 , there is a structure in which a plurality of metal particles are linked with each other with no interface present. The thermal conductivity of the thermally conductive material 50 can be improved by such a linked structure of metal particles.

[0029] Furthermore, in at least a portion of the bonding surface between the thermally conductive material 50 and the semiconductor element 20 or the bonding surface between the thermally conductive material 50 and the heat sink 30 , the thermally conductive material 50 can have a bonding structure with the surface of the semiconductor element 20 or the surface of the heat sink 30 via the metal particles therein.

[0030] According to this embodiment, by using a thermally conductive material having a particle connection structure formed by sintering metal particles through heat treatment as the thermally conductive material, the thermal conductivity of the thermally conductive material can be improved, and the semiconductor element and the heat dissipation component can be bonded, thereby improving the heat dissipation characteristics in the semiconductor package.

[0031] Hereinafter, the semiconductor package 100 will be described in detail.

[0032] Figure 1 The semiconductor package 100 includes a substrate 10 , a semiconductor element 20 , a heat sink 30 and a thermally conductive material 50 .

[0033] The semiconductor element 20 may be, for example, a logic chip, a memory chip, or an LSI chip in which a memory circuit and a logic circuit are mixed. The semiconductor element 20 may be formed by a BGA type package.

[0034] The semiconductor element 20 is mounted on the substrate 10 and electrically connected to the substrate 10. The semiconductor element 20 may be connected to the substrate 10 via a flip chip. In this case, the semiconductor element 20 is soldered to the substrate 10 via solder balls 60. An underfill material 70 may be filled in the gap between the semiconductor element 20 and the substrate 10. The underfill material 70 may use a known material, but may be a sealing material or a chip bonding material.

[0035] The substrate 10 may be, for example, a printed circuit board. One or more semiconductor elements 20 may be mounted on one side of the substrate 10. In addition, electronic components and heat sources other than the semiconductor elements 20 may be mounted on one side of the substrate 10. On the other hand, the other side of the substrate 10 (the side opposite to one side) may have a connection structure that can be connected to another substrate. Examples of the connection structure include solder balls and pin connectors.

[0036] The heat sink 30 may be composed of a component that dissipates heat from a heat source such as the semiconductor element 20, and may be composed of a metal material, for example. Examples of metal materials include copper, aluminum, and stainless steel. These may be used alone or in combination of two or more. The heat sink 30 may include a high thermal conductivity material other than a metal material, and may include graphite or the like.

[0037] The heat sink 30 may use a metal layer made of the above-mentioned metal material, be composed of a single layer thereof, or may be composed of a laminated structure formed by laminating multiple layers. In addition, at least the surface of the heat sink 30 that is bonded to the thermal conductive material 50 may expose the above-mentioned metal material, but may also be electroplated with other metals. For example, the plating film may be composed of nickel, gold, an alloy with these as the main component, or a laminated film of these. In this way, the rust resistance of the heat sink 30 can be improved.

[0038] The shape of the heat sink 30 is not particularly limited as long as it is a cover structure covering the semiconductor element 20. The heat sink 30 is composed of a housing whose surface facing the semiconductor element 20 is open. Specifically, the heat sink 30 may include: a plate-like portion having another surface facing one surface of the semiconductor element 20; and a side wall portion protruding from the other surface of the plate-like portion and provided around the plate-like portion in a manner covering the side surface of the semiconductor element 20.

[0039] The cross-sectional structure of the heat sink 30 may have, for example, a substantially U-shaped cross section when viewed in the stacking direction of the semiconductor element 20 and the heat sink 30 .

[0040] A part of the heat sink 30 may be bonded to the substrate 10 via an adhesive. For example, the front end of the side wall portion of the heat sink 30 may be bonded to one surface of the substrate 10 using an adhesive. A known adhesive may be used as the adhesive.

[0041] The thermally conductive material 50 is provided between one surface of the semiconductor element 20 and the other surface of the heat sink 30 opposite to the one surface, and bonds these.

[0042] The thermally conductive material 50 has a particle connection structure formed by sintering metal particles by heat treatment. The thermally conductive material 50 can be formed using a thermally conductive composition having a particle connection structure formed by sintering metal particles by heat treatment. The details of the thermally conductive composition will be described later.

[0043] The metal particles may include particles made of a metal. For example, the metal particles may include particles made of a metal consisting of one or more selected from the group consisting of silver, gold, and copper.

[0044] Furthermore, the lower limit of the thermal conductivity of the thermally conductive material 50 is, for example, 10 W / mK or more, preferably 15 W / mK or more, and more preferably 20 W / mK or more. This can improve the heat dissipation characteristics of the semiconductor package 100. On the other hand, the upper limit of the thermal conductivity of the thermally conductive material 50 can be, for example, 200 W / mK or less, or 150 W / mK or less. The thermal conductivity can be obtained by measuring in the thickness direction at 25°C using a laser flash method.

[0045] The average particle size D of the above metal particles is 50 The lower limit of is, for example, 0.8 μm or more, preferably 1.0 μm or more, and more preferably 1.2 μm or more. This can improve thermal conductivity. On the other hand, the average particle size D of the particles made of the metal is 50The upper limit is, for example, 7.0 μm or less, preferably 5.0 μm or less, and more preferably 4.0 μm or less. This can improve the sintering properties between metal particles. In addition, it is possible to improve the uniformity of sintering. The average particle size D of the particles composed of the metal is 50 The average particle size D of the silver particles can be used as 50 .

[0046] The upper limit of the standard deviation of the particle size of the particles composed of the metal is 2.0 μm or less, preferably 1.9 μm or less, and more preferably 1.8 μm or less. This can improve the uniformity during sintering. On the other hand, the lower limit of the standard deviation of the particle size of the particles composed of the metal is not particularly limited, and for example, it can be 0.1 μm or more, or 0.3 μm or more.

[0047] Furthermore, the metal particles may include metal-coated resin particles composed of resin particles and metal formed on the surface of the resin particles. The metal particles may include either metal-coated resin particles or particles composed of metal, but preferably include both.

[0048] Although the detailed mechanism is not yet clear, the use of metal-coated resin particles can improve the adhesion with the other surface of the heat sink 30 subjected to the nickel plating.

[0049] The thermally conductive material 50 may be composed of only a particle-connected structure of metal particles, but may also have a particle-connected structure and a resin present in the structure. This can improve thermal conductivity and reduce storage elastic modulus.

[0050] The upper limit of the storage modulus of the thermal conductive material 50 at 25°C is, for example, 10.0 GPa or less, preferably 9 GPa or less, and more preferably 8 GPa or less. Thus, the thermal conductive material 50 can be made less elastic, thereby suppressing the generation of cracks and the decrease in adhesion caused by stress strain. The upper limit of the storage modulus of the thermal conductive material 50 at 25°C can be, for example, 1 GPa or more, preferably 2 GPa or more, and more preferably 3 GPa or more. Thus, a thermal conductive material 50 with excellent durability can be realized. The storage modulus can be obtained by measuring using a dynamic viscoelasticity measurement (DMA) at a frequency of 1 Hz.

[0051] The thermally conductive material 50 may be formed on at least a portion of or the entire surface of one surface of the semiconductor element 20 .

[0052] like Figure 1 As shown, the semiconductor package 100 may further include a heat sink 80 and a thermally conductive material 90 .

[0053] The heat sink 80 can be bonded to the heat sink 30 via the thermally conductive material 90. The thermally conductive material 90 can be made of a known material, for example, grease.

[0054] The heat sink 80 may be formed of a member having excellent heat dissipation properties, and for example, a material used in the heat sink 30 may be used. The heat sink 80 may have a plurality of fins.

[0055] Hereinafter, each component of the thermally conductive composition according to the present embodiment will be described in detail.

[0056] The thermally conductive composition is used to form a thermally conductive material 50 in a semiconductor package. The semiconductor package includes a substrate, a semiconductor element 20 disposed on the substrate 10 , and a heat sink 30 surrounding the semiconductor element 20 , wherein the semiconductor element 20 and the heat sink 30 are bonded by the thermally conductive material 50 .

[0057] The thermally conductive composition can be formed into the thermally conductive material 50 by sintering the metal particles through heat treatment to form a particle connection structure.

[0058] The thermally conductive composition of the present embodiment contains the above-mentioned metal particles, a binder resin, and a monomer.

[0059] Although the detailed mechanism is still uncertain, it is believed that when the monomer volatilizes and the volume of the composition shrinks by heating, stress is applied in the direction in which the metal particles approach each other, the interface between the metal particles disappears, and a connection structure of the metal particles is formed. In addition, it is believed that when such metal particles are sintered, the binder resin, or the resin cured product of the binder resin and the curing agent or monomer, etc., remains inside or around the connection structure. In addition, it is also believed that through the curing reaction, a force such as agglomeration of multiple metal particles is generated.

[0060] By heating the thermally conductive composition, an adhesive layer (thermal conductive material 50) containing "particle interconnection structure of metal particles" and "resin component composed of binder resin, its cured product, resin particles in metal-coated resin particles, etc." can be realized.

[0061] Furthermore, using the thermally conductive composition, the lower limit of the thermal conductivity λ measured in the following step A is, for example, 10 W / mK or more, preferably 15 W / mK or more, and more preferably 20 W / mK or more. This can improve the heat dissipation characteristics of the semiconductor package 100. On the other hand, the upper limit of the thermal conductivity λ can be, for example, 200 W / mK or less, or 150 W / mK or less.

[0062] (Step A)

[0063] The thermally conductive composition was heated from 30°C to 200°C over 60 minutes and then heat treated at 200°C for 120 minutes to obtain a heat-treated body having a thickness of 1 mm. The thermal conductivity λ (W / mK) of the obtained heat-treated body was measured at 25°C using a laser flash method.

[0064] Using the thermally conductive composition, the upper limit of the storage modulus E at 25°C measured in accordance with the following step B is, for example, 10 GPa or less, preferably 9 GPa or less, and more preferably 8 GPa or less. As a result, the thermally conductive material 50 can be made less elastic, thereby suppressing the generation of cracks and the decrease in adhesion caused by stress strain. The upper limit of the storage modulus E at 25°C can be, for example, 1 GPa or more, preferably 2 GPa or more, and more preferably 3 GPa or more. As a result, a thermally conductive material 50 with excellent durability can be achieved. The storage modulus can be obtained by measuring using a dynamic viscoelasticity measurement (DMA) at a frequency of 1 Hz.

[0065] (Metal particles)

[0066] The thermally conductive composition of the present embodiment contains metal particles. The metal particles can be sintered by heat treatment to form a particle interconnected structure (sintered structure).

[0067] The metal particles may be metal-coated resin particles, particles made of metal, etc. The metal particles may include either metal-coated resin particles or particles made of metal, but more preferably include both.

[0068] By using the metal-coated resin particles, the storage modulus can be appropriately reduced while suppressing the decrease in the sinterability of the metal particles. By using the metal particles, the thermal conductivity can be appropriately increased while improving the sinterability of the metal particles.

[0069] The metal-coated resin particles are composed of resin particles and metal formed on the surface of the resin particles. That is, the metal-coated resin particles may be particles in which the surface of the resin particles is coated with a metal layer.

[0070] In this specification, the metal layer coating the surface of the resin particles refers to a state in which the metal layer covers at least a portion of the surface of the resin particles, and is not limited to a method of covering the entire surface of the resin particles. For example, it may include a method in which the metal layer partially covers the surface of the resin particles, and a method in which the metal layer covers the entire surface when viewed from a specific cross-section.

[0071] Among them, from the viewpoint of thermal conductivity, it is preferred that the metal layer covers the entire surface when viewed from a specific cross section, and it is more preferred that the metal layer covers the entire surface of the particle.

[0072] The metal in the metal-coated resin particles may include, for example, one or more selected from silver, gold, nickel and tin. These metals may be used alone or in combination of two or more. Alternatively, alloys containing these metals as main components may be used. Among them, silver may be used from the viewpoint of sinterability and thermal conductivity.

[0073] The resin material constituting the resin particles (core resin particles) in the metal-coated resin particles may include, for example, silicone, acrylic acid, phenol, polystyrene, melamine, polyamide, polytetrafluoroethylene, etc. These may be used alone or in combination of two or more. The resin particles may be composed of polymers using these. The polymer may be a homopolymer or a copolymer having these as the main component.

[0074] From the viewpoint of elasticity and heat resistance, silicone resin particles or acrylic resin particles can be used as the resin particles.

[0075] The silicone resin particles may be particles composed of an organopolysiloxane obtained by polymerizing an organochlorosilane such as methylchlorosilane, trimethyltrichlorosilane, or dimethyldichlorosilane, or may be silicone resin particles having a structure obtained by further three-dimensionally crosslinking the organopolysiloxane as a basic skeleton.

[0076] Furthermore, various functional groups may be introduced into the structure of the silicone resin particles. Examples of the functional groups that can be introduced include epoxy, amino, methoxy, phenyl, carboxyl, hydroxyl, alkyl, vinyl, and mercapto groups, but are not limited thereto.

[0077] In addition, in the present embodiment, other low stress modifiers can be added to the silicone resin particles within a range that does not impair the properties. Other low stress modifiers that can be used simultaneously include butadiene styrene rubber, butadiene acrylonitrile rubber, polyurethane rubber, polyisoprene rubber, acrylic rubber, fluororubber, liquid organopolysiloxane, liquid polybutadiene and other liquid synthetic rubbers, but are not limited to these.

[0078] The shape of the resin particles is not particularly limited, and may be spherical, but may also be a different shape other than a sphere, such as a flat shape (flake shape), a plate shape, or a needle shape. When the metal-coated resin particles are formed into a spherical shape, it is preferred that the shape of the resin particles used is also a spherical shape. In addition, the so-called spherical shape, as described above, is not limited to a perfect sphere, but also includes a shape close to a sphere such as an ellipse, a shape having a plurality of concave and convex shapes on the surface, and the like.

[0079] The lower limit of the specific gravity of the metal-coated resin particles is, for example, 2 or more, preferably 2.5 or more, and more preferably 3 or more. This can further improve the thermal conductivity and electrical conductivity of the adhesive layer. In addition, the upper limit of the specific gravity of the metal-coated resin particles is, for example, 10 or less, preferably 9 or less, and more preferably 8 or less. This can improve the dispersibility of the particles. The specific gravity may be the specific gravity of metal particles including metal-coated resin particles and particles composed of metal.

[0080] The metal-coated resin particles may be monodisperse particles or polydisperse particles. Furthermore, in the particle size frequency distribution, the metal-coated resin particles may have one peak or two or more peaks.

[0081] The above-mentioned particles composed of metal can be particles composed of one or more metal materials, and the core part and the surface part can be composed of the same or different types of metal materials. The metal material can include one or more selected from silver, gold and copper. These metals can be used alone or in combination of two or more. Alternatively, alloys with these metals as the main components can be used. Among them, silver can be used from the viewpoint of sinterability and thermal conductivity.

[0082] The shape of the particles made of metal may be, for example, spherical or flake-shaped. The particles made of metal may include either or both spherical particles and flake-shaped particles.

[0083] In one embodiment of the metal particles, the metal-coated resin particles include silver-coated silicone resin particles, and the metal particles include silver particles.

[0084] In addition to silver-coated silicone particles, silver-coated acrylic particles may also be used from the viewpoint of elastic properties. In addition to silver particles, particles containing metal components other than silver, such as gold particles and copper particles, may also be used for purposes such as promoting sintering or reducing costs.

[0085] The average particle size D of the metal-coated resin particles 50 The lower limit of can be, for example, 0.5 μm or more, preferably 1.5 μm or more, and more preferably 2.0 μm or more. In this way, the storage modulus can be reduced. On the other hand, the average particle size D of the metal-coated resin particles is 50 The upper limit of the particle size D of the metal-coated resin particles may be, for example, 20 μm or less, 15 μm or less, or 10 μm or less. This can improve thermal conductivity. 50 The average particle size D of silver-coated silicone resin particles and silver-coated acrylic resin particles can be used as 50 .

[0086] The average particle size D of the above metal particles is 50 The lower limit of is, for example, 0.8 μm or more, preferably 1.0 μm or more, and more preferably 1.2 μm or more. This can improve thermal conductivity. On the other hand, the average particle size D of the particles made of the metal is 50 The upper limit is, for example, 7.0 μm or less, preferably 5.0 μm or less, and more preferably 4.0 μm or less. This can improve the sintering properties between metal particles. Also, the uniformity of sintering can be improved. The average particle size D of the particles composed of the metal is 50 The average particle size D of the silver particles can be used as 50 .

[0087] Furthermore, the metal particles may include two or more particles having different particle sizes D50. This can improve sinterability.

[0088] In addition, the average particle size D of the metal particles 50 For example, the particle size can be determined by measuring a particle image using a flow particle image analyzer FPIA (registered trademark)-3000 manufactured by Sysmex Corporation. More specifically, the particle size of the metal particles can be determined by measuring a volume-based median particle size using the above device.

[0089] The content of the metal-coated resin particles is, for example, 1% to 50% by mass, preferably 3% to 45% by mass, and more preferably 5% to 40% by mass, relative to the entire metal particles (100% by mass). By making the content of the metal-coated resin particles greater than the above lower limit, the storage modulus can be reduced. By making the content of the metal-coated resin particles less than the above upper limit, the thermal conductivity can be increased.

[0090] In this specification, “to” means including the upper limit and the lower limit unless otherwise specified.

[0091] The content of the metal particles is 1% to 98% by mass, preferably 30% to 95% by mass, and more preferably 50% to 90% by mass, relative to the entire thermally conductive composition (100% by mass). By making the content of the metal particles greater than the lower limit, thermal conductivity can be improved. By making the content of the metal particles less than the upper limit, coating properties and workability during pasting can be improved.

[0092] (Binder resin)

[0093] The thermally conductive composition contains a binder resin.

[0094] The binder resin may include one or more selected from epoxy resins, acrylic resins, and allyl resins, and these may be used alone or in combination of two or more.

[0095] Specific examples of the binder resin include acrylic resins such as acrylic oligomers and acrylic polymers, epoxy resins such as epoxy oligomers and epoxy polymers, and allyl resins such as allyl oligomers and allyl polymers. These may be used alone or in combination of two or more.

[0096] In addition, those with a weight average molecular weight of less than 10,000 are referred to as oligomers, and those with a weight average molecular weight of 10,000 or more are referred to as polymers.

[0097] As the epoxy resin, an epoxy resin having two or more epoxy groups in the molecule can be used. The epoxy resin can be in a liquid state at 25° C. Thus, the handling property of the thermally conductive composition can be improved. In addition, the curing shrinkage can be appropriately adjusted.

[0098] Specific examples of the epoxy resin include trisphenol methane epoxy resin, hydrogenated bisphenol A liquid epoxy resin, bisphenol F liquid epoxy resin such as bisphenol-F-diglycidyl ether, or o-cresol novolac epoxy resin, etc. These may be used alone or in combination of two or more.

[0099] Among them, hydrogenated bisphenol A type liquid epoxy resin or bisphenol F type liquid epoxy resin can be used. As the bisphenol F type liquid epoxy resin, for example, bisphenol-F-diglycidyl ether can be used.

[0100] As the acrylic resin, an acrylic resin having two or more acrylic groups in a molecule may be used. The acrylic resin may be in a liquid state at 25°C.

[0101] Specifically, the acrylic resin may be obtained by (co)polymerizing an acrylic acid monomer. The (co)polymerization method is not limited, and a known method using a common polymerization initiator and a chain transfer agent such as solution polymerization may be used.

[0102] As the allyl resin, an allyl resin having two or more allyl groups in one molecule may be used. The allyl resin may be in a liquid state at 25°C.

[0103] Specific examples of the allyl resin include allyl ester resins obtained by reacting dicarboxylic acid, allyl alcohol, and a compound having an allyl group.

[0104] Here, as the above-mentioned dicarboxylic acid, specifically, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, etc. are mentioned. And as the above-mentioned compound having an allyl group, specifically, polyether, polyester, polycarbonate, polyacrylate, polymethacrylate, polybutadiene, butadiene acrylonitrile copolymer, etc. are mentioned having an allyl group.

[0105] The lower limit of the content of the above-mentioned binder resin is, for example, 1 part by mass or more, preferably 2 parts by mass or more, and more preferably 3 parts by mass or more, relative to 100 parts by mass of the thermally conductive composition. Thus, the adhesion with the adherend can be improved. On the other hand, the upper limit of the content of the above-mentioned binder resin is, for example, 15 parts by mass or less, preferably 12 parts by mass or less, and more preferably 10 parts by mass or less, relative to 100 parts by mass of the thermally conductive composition. Thus, the decrease in thermal conductivity can be suppressed.

[0106] (monomer)

[0107] The thermally conductive composition contains a monomer.

[0108] The monomers may include one or more selected from the group consisting of diol monomers, acrylic monomers, epoxy monomers, and maleimide monomers. These monomers may be used alone or in combination of two or more.

[0109] By using the monomer, the volatilization state of the thermally conductive composition during heat treatment can be adjusted. In addition, by appropriately selecting a combination with a binder resin and a curing agent, the monomer can undergo a curing reaction with these and the curing shrinkage state can be adjusted.

[0110] Specifically, the diol monomers include: a diol having two hydroxyl groups in the molecule, wherein the two hydroxyl groups are bonded to different carbon atoms; a compound obtained by alcohol condensation of two or more of the diols; a compound obtained by alcohol condensation in which the hydrogen atom in the hydroxyl group of the compound is replaced by an organic group having 1 to 30 carbon atoms to form an alkoxy group; and the like.

[0111] Specific examples of the diol monomer include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol monoisobutyl ether, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monoallyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol mono-2-ethylhexyl ether, diethylene glycol monoallyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol mono-2-ethylhexyl ether, diethylene glycol monoallyl ether, Ethylene glycol monobenzyl ether, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol mono-n-butyl ether, tetraethylene glycol, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol mono-n-butyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol mono-n-butyl ether, propylene glycol monophenyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol mono-n-butyl ether etc. These can be used alone, or two or more combinations can be used. Wherein, from the viewpoint of volatility, tripropylene glycol mono-n-butyl ether or ethylene glycol monoacetic acid n-butyl ester can be used.

[0112] The lower limit of the boiling point of the diol monomer is, for example, preferably 100° C. or higher, more preferably 130° C. or higher, further preferably 150° C. or higher, further preferably 170° C. or higher, and particularly preferably 190° C. or higher. The upper limit of the boiling point of the diol monomer is, for example, 400° C. or lower, or 350° C. or lower.

[0113] In addition, the boiling point of the diol monomer indicates the boiling point under atmospheric pressure (101.3 kPa).

[0114] Examples of the acrylic monomer include monomers having a (meth)acrylic group in the molecule.

[0115] Here, the (meth)acrylic group means an acrylic group and a methacrylic group.

[0116] The acrylic monomer may be a monofunctional acrylic monomer having only one (meth)acrylic group in the molecule, or may be a polyfunctional acrylic monomer having two or more (meth)acrylic groups in the molecule.

[0117] Specific examples of the monofunctional acrylic monomer include 2-phenoxyethyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, isoamyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, n-lauryl (meth)acrylate, n-tridecyl (meth)acrylate, n-stearyl (meth)acrylate, isostearyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, butoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 2-ethylhexyldiethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, and the like. Acrylate, phenoxy polyethylene glycol (meth) acrylate, nonylphenol ethylene oxide modified (meth) acrylate, phenylphenol ethylene oxide modified (meth) acrylate, isobornyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate quaternary compound, glycidyl (meth) acrylate, neopentyl glycol (meth) acrylate benzoate, 1,4-cyclohexanedimethanol mono(meth) acrylate acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalic acid, and 2-(meth)acryloyloxyethyl acid phosphate, etc.

[0118] Specific examples of the multifunctional acrylic monomer include ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, hexane-1,6-diol bis(2-(meth)acrylate methyl), 4,4'-isopropylidene diphenol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,6-bis((meth)acryloyloxy)-2,2,3,3,4, 4,5,5-octafluorohexane, 1,4-bis((meth)acryloyloxy)butane, 1,6-bis((meth)acryloyloxy)hexane, triethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, N,N'-di(meth)acryloylethylenediamine, N,N'-(1,2-dihydroxyethylene)bis(meth)acrylamide or 1,4-bis((meth)acryloyl)piperazine, etc.

[0119] As the acrylic monomer, a monofunctional acrylic monomer or a polyfunctional acrylic monomer may be used alone, or a monofunctional acrylic monomer and a polyfunctional acrylic monomer may be used together. As the acrylic monomer, for example, it is preferred to use a polyfunctional acrylic monomer alone.

[0120] The epoxy monomer is a monomer having an epoxy group in the molecule.

[0121] The epoxy monomer may be a monofunctional epoxy monomer having only one epoxy group in the molecule, or may be a polyfunctional epoxy monomer having two or more epoxy groups in the molecule.

[0122] Specific examples of the monofunctional epoxy monomer include 4-tert-butylphenyl glycidyl ether, m-cresyl glycidyl ether, p-cresyl glycidyl ether, phenyl glycidyl ether, and cresyl glycidyl ether.

[0123] Specific examples of the polyfunctional epoxy monomer include: bisphenol compounds such as bisphenol A, bisphenol F, and biphenol, or derivatives thereof; diols having an alicyclic structure such as hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated biphenol, cyclohexanediol, cyclohexanedimethanol, and cyclohexanediethanol, or derivatives thereof; bifunctional monomers obtained by epoxidizing aliphatic diols such as butanediol, hexanediol, octanediol, nonanediol, and decanediol, or derivatives thereof; trifunctional monomers having a trihydroxyphenylmethane skeleton or an aminophenol skeleton; polyfunctional monomers obtained by epoxidizing novolac resins, cresol novolac resins, phenol aralkyl resins, biphenyl aralkyl resins, and naphthol aralkyl resins, etc.

[0124] The maleimide monomer is a monomer having a maleimide ring in the molecule.

[0125] The maleimide monomer may be a monofunctional maleimide monomer having only one maleimide ring in the molecule, or may be a polyfunctional maleimide monomer having two or more maleimide rings in the molecule.

[0126] Specific examples of the maleimide monomer include polytetramethylene ether glycol-bis(2-maleimidoacetate) and the like.

[0127] The lower limit of the content of the above monomer is, for example, 0.5 parts by mass or more, preferably 1.0 parts by mass or more, and more preferably 2.0 parts by mass or more, relative to 100 parts by mass of the thermally conductive composition. On the other hand, the upper limit of the content of the above monomer is, for example, 10 parts by mass or less, preferably 7 parts by mass or less, and more preferably 5 parts by mass or less, relative to 100 parts by mass of the thermally conductive composition.

[0128] (Curing agent)

[0129] The thermally conductive composition may contain a curing agent as necessary.

[0130] The curing agent has a reactive group that reacts with a functional group in the monomer or the binder resin. Examples of the reactive group include a group that reacts with a functional group such as an epoxy group, a maleimide group, or a hydroxyl group.

[0131] Specifically, when the monomer includes an epoxy monomer and / or the binder resin includes an epoxy resin, a phenol resin-based curing agent or an imidazole-based curing agent may be used as the curing agent.

[0132] As the above-mentioned phenolic resin curing agent, specifically, there can be mentioned novolac type phenolic resins such as novolac resin, cresol novolac resin, bisphenol novolac resin, and phenol-biphenyl novolac resin; polyvinylphenol; multifunctional phenolic resins such as triphenylmethane type phenolic resin; modified phenolic resins such as terpene modified phenolic resin and dicyclopentadiene modified phenolic resin; phenol aralkyl type phenolic resins such as phenol aralkyl resins having a phenylene skeleton and / or a biphenylene skeleton, and naphthol aralkyl resins having a phenylene and / or a biphenylene skeleton; bisphenol compounds such as bisphenol A and bisphenol F (dihydroxydiphenylmethane) (phenolic resins having a bisphenol F skeleton); compounds having a biphenylene skeleton such as 4,4'-biphenol, etc. These can be used alone or in combination of two or more.

[0133] Among them, a phenol aralkyl resin can be used, and as the phenol aralkyl resin, a phenol / p-xylene dimethyl ether polycondensate can be used.

[0134] Specific examples of the imidazole curing agent include 2-phenyl-1H-imidazole-4,5-dimethanol, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-methylimidazole, 2-phenylimidazole, 2,4-diamino-6-[2-methylimidazolyl-(1)]-ethyl-s-triazine, 2-undecylimidazole, 2-heptadecylimidazole, 2,4-diamino-6-[2-methylimidazolyl-(1)]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 1-cyanoethyl-2-phenylimidazolium trimellitic acid, 1-cyanoethyl-2-undecylimidazole trimellitic acid, etc. These can be used alone or in combination of two or more.

[0135] The content of the curing agent may be, for example, 5 to 50 parts by mass, or 20 to 40 parts by mass, relative to 100 parts by mass of the binder resin in the thermally conductive composition.

[0136] The content of the curing agent may be, for example, 1 to 40 parts by mass, or 10 to 35 parts by mass, relative to 100 parts by mass of the epoxy resin or 100 parts by mass of the total of the epoxy resin and the epoxy monomer in the thermally conductive composition.

[0137] (Free Radical Polymerization Initiator)

[0138] The thermally conductive composition may contain a radical polymerization initiator.

[0139] As the radical polymerization initiator, an azo compound, a peroxide, or the like can be used.

[0140] Specific examples of the peroxide include bis(1-phenyl-1-methylethyl)peroxide, 1,1-bis(1,1-dimethylethylperoxy)cyclohexane, methyl ethyl ketone peroxide, cyclohexane peroxide, acetylacetone peroxide, 1,1-di(tert-hexylperoxy)cyclohexane, 1,1-di(tert-butylperoxy)-2-methylcyclohexane, 1,1-di(tert-butylperoxy)cyclohexane, 2,2-di(tert-butylperoxy)butane, n-butyl-4,4-di(tert-butylperoxy)valerate, 2,2-di(4,4-di(tert-butylperoxy)cyclohexane)propane, and p-butyl-4,4-di(tert-butylperoxy)valerate. Methane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, isopropylbenzene hydroperoxide, tert-butyl hydroperoxide, di(2-tert-butylperoxyisopropyl)benzene, diisopropylphenyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylisopropylphenyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, diisobutyl peroxide, di(3,5,5-trimethylhexanoyl) peroxide, dilauryl peroxide, di(3-methylbenzoyl) peroxide Peroxide, benzoyl (3-methylbenzoyl) peroxide, dibenzoyl peroxide, di (4-methylbenzoyl) peroxide, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, di-sec-butyl peroxydicarbonate, isopropyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, tert-hexyl neodecanoate, tert-butyl peroxyneoheptanoate, tert-hexyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di (2-diethyl) peroxydicarbonate tert-Butyl peroxy-2-ethylhexanoate, tert-Hexyl peroxyisopropyl monocarbonate, tert-Butyl peroxymaleic acid, tert-Butyl peroxy-3,5,5-trimethylhexanoate, tert-Butyl peroxyisopropyl monocarbonate, tert-Butyl peroxy-2-ethylhexyl monocarbonate, tert-Hexyl peroxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, tert-Butyl peroxyacetonate, tert-Peroxy-3-methylbenzoate, tert-Butyl peroxybenzoate, tert-Butyl peroxyallyl monocarbonate, 3,3',4,4'-tetra(tert-Butyl peroxyhydroxy)benzophenone, etc. These may be used alone or in combination of two or more.

[0141] (Curing accelerator)

[0142] The thermally conductive composition may contain a curing accelerator.

[0143] The curing accelerator can accelerate the reaction between the binder resin or the monomer and the curing agent.

[0144] Specifically, the curing accelerator includes: compounds containing phosphorus atoms such as organic phosphines, tetrasubstituted phosphonium compounds, phosphobetaine compounds, adducts of phosphine compounds and quinone compounds, adducts of phosphonium compounds and silane compounds; amidines or tertiary amines such as dicyandiamide, 1,8-diazabicyclo[5.4.0]undecene-7, and benzyldimethylamine; compounds containing nitrogen atoms such as quaternary ammonium salts of the amidines or tertiary amines, etc. These may be used alone or in combination of two or more.

[0145] (Silane coupling agent)

[0146] The thermally conductive composition may contain a silane coupling agent.

[0147] The silane coupling agent can improve the adhesion between the adhesion layer formed using the thermally conductive composition and the substrate or the semiconductor element.

[0148] Specifically, the silane coupling agent may be vinyl silanes such as vinyl trimethoxysilane and vinyl triethoxysilane; epoxy silanes such as 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl methyl dimethoxysilane, 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl methyl diethoxysilane, and 3-glycidyloxypropyl triethoxysilane; styryl silanes such as p-styryl trimethoxysilane; 3-methacryloxypropyl methyl dimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl methyl diethoxysilane, and 3-methacryloxypropyl triethoxysilane; Methacrylsilane; acrylic silanes such as 3-(trimethoxysilyl)propyl methacrylate and 3-acryloxypropyltrimethoxysilane; aminosilanes such as N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylene)propylamine and N-phenyl-γ-aminopropyltrimethoxysilane; isocyanate silanes; alkylsilanes; ureidosilanes such as 3-ureidopropyltrialkoxysilane; mercaptosilanes such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; isocyanate silanes such as 3-isocyanatepropyltriethoxysilane. These may be used alone or in combination of two or more.

[0149] (Plasticizer)

[0150] The thermally conductive composition may contain a plasticizer. Adding a plasticizer can reduce stress.

[0151] Specific examples of the plasticizer include silicone compounds such as silicone oil and silicone rubber, polybutadiene compounds such as polybutadiene maleic anhydride adducts, acrylonitrile butadiene copolymer compounds, etc. These may be used alone or in combination of two or more.

[0152] (Other ingredients)

[0153] In addition to the above-mentioned components, the thermally conductive composition may contain other components as necessary. Examples of other components include solvents.

[0154] The solvent is not particularly limited, and can include, for example, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, methyl methoxybutanol, α-terpineol, β-terpineol, hexylene glycol, benzyl alcohol, 2-phenylethyl alcohol, isopalmitoyl alcohol, isostearyl alcohol, 1,2-dimethylbenzene ... Alcohols such as butyl alcohol, ethylene glycol, propylene glycol, butyl glycerol or glycerol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diacetone alcohol (4-hydroxy-4-methyl-2-pentanone), 2-octanone, isophorone (3,5,5-trimethyl-2-cyclohexene-1-one) or diisobutyl ketone (2,6-dimethyl-4-heptanone); ethyl acetate, butyl acetate, diethyl phthalate, dibutyl phthalate, acetoxy ethane, methyl butyrate, methyl caproate, methyl octanoate, methyl decanoate, methyl cellulose acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, 1,2-diacetoxyethane, tributyl phosphate, tricresyl phosphate or tripentyl phosphate; tetrahydrofuran, dipropyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, ethoxyethyl ether, 1,2-bis(2-diethoxy)ethane or 1,2-bis Ethers such as (2-methoxyethoxy)ethane; ester ethers such as 2-(2-butoxyethoxy)ethane acetate; ether alcohols such as 2-(2-methoxyethoxy)ethanol, hydrocarbons such as toluene, xylene, normal alkanes, isoalkanes, dodecylbenzene, turpentine, kerosene or light oil; nitriles such as acetonitrile or propionitrile; amides such as acetamide or N,N-dimethylformamide; one or more of silicone oils such as low molecular weight volatile silicone oil or volatile organic modified silicone oil.

[0155] By using the above-mentioned solvent, the fluidity of the above-mentioned thermally conductive composition can be controlled. For example, the operability of the above-mentioned thermally conductive composition in a paste form can be improved. In addition, sintering can be promoted by shrinkage during heating. Among the solvents, by using a solvent with a relatively high boiling point, preferably a solvent with a boiling point higher than the curing temperature, the generation of pores in the adhesive layer obtained by heat treating the thermally conductive composition can be suppressed. The boiling point of the high boiling point solvent can be, for example, 180°C to 450°C, or 200°C to 400°C.

[0156] Hereinafter, a method for producing the thermally conductive composition according to the present embodiment will be described.

[0157] As a method for producing the thermally conductive composition, a method of mixing the above-mentioned raw material components can be used. The mixing can be carried out by a known method, for example, a three-roll mixer or the like.

[0158] The obtained mixture may be further defoamed, for example, by leaving the mixture to stand under vacuum.

[0159] Next, a method for manufacturing the semiconductor package 100 according to the present embodiment will be described.

[0160] An example of the semiconductor package 100 according to the present embodiment can be manufactured using the above-mentioned thermally conductive composition.

[0161] The method for manufacturing the semiconductor package 100 may include: a step of arranging a semiconductor element 20 on one surface of a substrate 10 in such a manner that the other surface of the semiconductor element 20 is opposite to one surface of the substrate 10; a step of applying the above-mentioned thermally conductive composition containing metal particles on the surface of one side (the side opposite to the other side) of the semiconductor element 20; a step of configuring a heat sink 30 in such a manner as to contact with the thermally conductive composition and cover at least one side of the semiconductor element 20; and a step of heating a structure including the substrate 10, the semiconductor element 20, the thermally conductive composition and the heat sink 30.

[0162] The semiconductor package 100 may include the following step: in the step of performing a heat treatment, the semiconductor element 10 and the heat sink 30 are bonded via the thermally conductive material 50 including a particle connection structure formed by sintering of metal particles.

[0163] Furthermore, the method for manufacturing the semiconductor package 100 may include a step of drying the thermally conductive composition after the coating step and before the placement step. This can improve the leveling property.

[0164] Furthermore, in the application step, the thermally conductive composition may be applied using a dispenser, thereby improving workability.

[0165] The embodiments of the present invention are described above, but these are examples of the present invention, and various configurations other than the above can be adopted. Furthermore, the present invention is not limited to the above embodiments, and modifications and improvements within the scope of achieving the purpose of the present invention are included in the present invention.

[0166] [Example]

[0167] Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited at all to what is described in these Examples.

[0168] <Thermal conductive composition>

[0169] The respective raw material components were mixed in the amounts shown in the following Table 1 to obtain a varnish.

[0170] The obtained varnish, solvent, and metal particles were blended in the amounts shown in Table 1 below, and kneaded using a three-roll mill at room temperature to prepare a paste-like thermally conductive composition.

[0171] The information of the raw material components in Table 1 is shown below.

[0172] (Binder resin)

[0173] Epoxy resin 1: Bisphenol F type liquid epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE-303S)

[0174] (Curing agent)

[0175] Curing agent 1: Phenolic resin having a bisphenol F skeleton (solid at room temperature 25°C, manufactured by DIC Corporation, DIC-BPF)

[0176] Curing agent 2: m-cresol glycidyl ether, p-cresol glycidyl ether (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., mp-CGE)

[0177] (Acrylic acid monomer)

[0178] Acrylic monomer 1: (Meth)acrylic monomer (ethylene glycol dimethacrylate, manufactured by KYOEISHA CHEMICAL Co., LTD., Light Ester EG)

[0179] Acrylic monomer 2: Polyolefin glycol dimethacrylate (manufactured by NOF CORPORATION, PDE-600)

[0180] (Plasticizer)

[0181] Plasticizer 1: Allyl resin (manufactured by KANTO KAGAKU Co., Ltd., polymer of bis(2-propylene) 1,2-cyclohexanedicarboxylate and propane-1,2-diol)

[0182] (Silane coupling agent)

[0183] Silane coupling agent 1: 3-(trimethoxysilyl)propyl methacrylate (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-503P)

[0184] Silane coupling agent 2: 3-glycidyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403E)

[0185] (Curing accelerator)

[0186] Imidazole curing agent 1: 2-phenyl-1H-imidazole-4,5-dimethanol (manufactured by SHIKOKU CHEMICALS CORPORATION, 2PHZ-PW)

[0187] (Polymerization initiator)

[0188] Radical polymerization initiator 1: diisopropylphenyl peroxide (manufactured by Kayaku Akzo Corporation, Perkadox BC)

[0189] (Solvent)

[0190] Solvent 1: Butyl propylene glycol (BFTG)

[0191] (Metal particles)

[0192] Silver particles 1: Silver powder (manufactured by DOWA HIGHTECH CO., LTD., AG-DSB-114, spherical, D 50 :1μm)

[0193] Silver particles 2: Silver powder (manufactured by Fukuda Metal Foil & Powder Co., Ltd., HKD-16, flake, D 50 :2μm)

[0194] Silver-coated resin particles 1: Silver-plated acrylic resin particles (SANSILVER-8D, spherical, D 50: 8μm, monodisperse particles, specific gravity: 2.4, weight ratio of silver is 50wt%, weight ratio of resin is 50wt%)

[0195] Silver particles 3: Silver powder (TC-88, manufactured by TOKURIKI HONTEN CO., LTD.), flake, D 50 :3μm)

[0196] [Table 1]

[0197]

[0198] Using the obtained thermally conductive composition, the following physical properties were measured and the evaluation items were evaluated.

[0199] (Thermal conductivity)

[0200] The obtained thermally conductive composition was heated from 30°C to 200°C over 60 minutes, and then heat treated at 200°C for 120 minutes to obtain a heat-treated body having a thickness of 1 mm. Then, the thermal diffusion coefficient α in the thickness direction of the heat-treated body was measured using a laser flash method. The measurement temperature was 25°C.

[0201] Furthermore, the specific heat Cp was measured by differential scanning calorimetry (DSC), and the density ρ was measured in accordance with JIS-K-6911. Using these values, the thermal conductivity λ was calculated based on the following formula.

[0202] The evaluation results are shown in the following Table 1. In addition, the unit is W / (m·K).

[0203] Thermal conductivity λ[W / (m·K)]=α[m 2 / sec]×Cp[J / kg·K]×ρ[g / cm 3 ]

[0204] The thermal conductivity of Example 1 and Reference Example 1 is 20 W / (m·K) or more, and can be used without any problem in practical use.

[0205] (Storage modulus)

[0206] The obtained thermally conductive composition was heated from 30°C to 200°C over 60 minutes, and then heat treated at 200°C for 120 minutes to obtain a heat-treated body. The storage modulus E (MPa) of the obtained heat-treated body at 25°C was measured by dynamic viscoelasticity measurement (DMA) at a frequency of 1 Hz using a measuring device (DMS6100 manufactured by Hitachi High-Tech Science Corporation).

[0207] (Observation of particle connection structure)

[0208] A copper lead frame and a silicon wafer (length 2 mm×width 2 mm, thickness 0.35 mm) were prepared. Next, the obtained thermally conductive composition was applied to the silicon wafer in a coating thickness of 25±10 μm, and the copper lead frame was arranged thereon. A laminated body in which the silicon wafer, the thermally conductive composition, and the copper lead frame were sequentially stacked was produced.

[0209] Next, the obtained laminate was heated from 30° C. to 200° C. in the atmosphere over 60 minutes, and then heat-treated at 200° C. for 120 minutes to cure the thermally conductive composition in the laminate, thereby obtaining a thermally conductive material.

[0210] Next, the cross section of the heat-treated body of the thermally conductive composition in the laminate was observed using a scanning electron microscope (SEM), and the state thereof was evaluated.

[0211] In Example 1, Figure 2 As shown in FIG. 1 , it was confirmed that a silver particle connection structure was formed. Figure 2 ), it was also confirmed that the silver particle connection structure contained a plurality of substantially circular resin particles, and the metal layer (silver layer) on the surface of the resin particles was connected to the silver particle connection structure. Furthermore, it was confirmed that the cured product of the binder resin was present in the portion other than silver in the silver particle connection structure in a manner covering the silver.

[0212] (Chip shear strength)

[0213] The obtained thermally conductive composition was applied on a nickel-plated copper substrate, and a nickel-plated silicon wafer (2 mm×2 mm) was mounted thereon. The composition was then heated to 30° C. to 200° C. in an oven for 60 minutes, and then heated at 200° C. for 120 minutes to cure.

[0214] The sample was placed on a hot plate heated to 260° C., and the chip shear strength (N / 2 mm×2 mm) was measured using DAGE-4000 (manufactured by Nordson Corporation).

[0215] In Examples 1 to 3, cohesive failure occurred inside the thermally conductive material, and in Reference Example 1, interfacial delamination occurred at the interface between the thermally conductive material and the lead frame.

[0216] Using the thermally conductive compositions of Examples 1 to 3, semiconductor packages were obtained in the following manner.

[0217] A semiconductor element is arranged on one side of a substrate in such a manner that the other side of the semiconductor element faces one side of the substrate. A thermally conductive composition containing metal particles is applied to the surface of one side of the semiconductor element. A heat sink is arranged in such a manner that it contacts the thermally conductive composition and covers one side of the semiconductor element. A structure including the substrate, the semiconductor element, the thermally conductive composition and the heat sink is subjected to a heat treatment. By the heat treatment, the semiconductor element and the heat sink are bonded via a thermally conductive material having a particle connection structure formed by sintering the metal particles in the thermally conductive composition, thereby obtaining a semiconductor package.

[0218] As Comparative Example 1, an acrylic adhesive was used instead of the thermally conductive composition of Example 1 to obtain a semiconductor package.

[0219] The semiconductor packages of Examples 1 to 3 and Comparative Example 1 were used as evaluation samples, and the thermal diffusion coefficient of the surface of the semiconductor element was measured by the laser flash method. Examples 1 to 3 showed higher thermal diffusion coefficients than Comparative Example 1, and thus it was found that the semiconductor packages of Examples 1 to 3 can have a structure with excellent heat dissipation characteristics.

[0220] Furthermore, in the semiconductor packages of Examples 1 to 3, compared with Comparative Example 1, the bonding strengths at the bonding interface between the thermally conductive material and the semiconductor element and at the bonding interface between the thermally conductive material and the heat sink were higher.

[0221] It is found that the thermally conductive materials of Examples 1 to 3 have better chip shear strength than Reference Example 1. By using the thermally conductive materials of Examples 1 to 3 as TIM1 materials, a semiconductor package having excellent heat dissipation characteristics can be realized.

[0222] This application claims priority based on Japanese patent application No. 2019-052739, filed on March 20, 2019, and all the disclosed contents are incorporated herein by reference.

Claims

1. A semiconductor package, comprising a substrate, a semiconductor element disposed on the substrate, and a heat sink surrounding the semiconductor element, wherein the semiconductor element and the heat sink are bonded by a thermally conductive material, wherein: The thermally conductive material has a particle connection structure formed by sintering metal particles through heat treatment.

2. The semiconductor package according to claim 1, wherein: The thermal conductive material has a storage modulus at 25° C. measured by dynamic viscoelasticity measurement (DMA) at a frequency of 1 Hz of 1 GPa or more and 10.0 GPa or less.

3. The semiconductor package according to claim 1 or 2, wherein: The thermal conductivity of the thermally conductive material at 25° C. measured by a laser flash method is 10 W / mK or more.

4. The semiconductor package according to any one of claims 1 to 3, characterized in that: The metal particles include particles composed of metal, The particle size D50 at the cumulative 50% in the volume-based cumulative distribution of the particles made of the metal is 0.8 μm or more and 7.0 μm or less.

5. The semiconductor package according to claim 4, wherein: The standard deviation of the particle diameter of the metal particles is 2.0 μm or less.

6. The semiconductor package according to claim 4 or 5, characterized in that: The metal particles include two or more types of particles having different particle diameters D50.

7. The semiconductor package according to any one of claims 4 to 6, characterized in that: The metal particles include spherical particles and flake-shaped particles.

8. The semiconductor package according to any one of claims 1 to 7, characterized in that: The metal particles include metal-coated resin particles composed of resin particles and metal formed on surfaces of the resin particles.

9. The semiconductor package according to any one of claims 1 to 8, characterized in that: The metal particles include particles composed of a metal consisting of one or more selected from the group consisting of silver, gold, and copper.

10. A thermally conductive composition for forming a thermally conductive material in a semiconductor package, wherein the semiconductor package comprises a substrate, a semiconductor element disposed on the substrate, and a heat sink surrounding the semiconductor element, wherein the semiconductor element and the heat sink are bonded by the thermally conductive material, wherein the thermally conductive composition comprises: Metal particles; Binder resin; and monomer, The metal particles are sintered by heat treatment to form a particle interconnected structure.

11. The thermally conductive composition according to claim 10, characterized in that: Using the thermally conductive composition, the thermal conductivity λ measured in accordance with the following step A is 10 W / mK or more, (Step A) The thermally conductive composition was heated from 30°C to 200°C over 60 minutes and then heat treated at 200°C for 120 minutes to obtain a heat-treated body having a thickness of 1 mm. The thermal conductivity λ (W / mK) of the obtained heat-treated body was measured at 25°C using a laser flash method.

12. The thermally conductive composition according to claim 10 or 11, characterized in that: Using the thermally conductive composition, the storage modulus E at 25° C. measured in the following procedure B is 1 GPa or more and 10.0 GPa or less, (Step B) The thermally conductive composition was heated from 30°C to 200°C over 60 minutes and then heat treated at 200°C for 120 minutes to obtain a heat-treated body. The storage modulus E (MPa) at 25°C of the obtained heat-treated body was measured using a dynamic viscoelasticity measurement (DMA) at a frequency of 1 Hz.

13. The thermally conductive composition according to any one of claims 10 to 12, characterized in that: The metal particles include particles composed of one or more metal materials selected from the group consisting of silver, gold, and copper.

14. The thermally conductive composition according to any one of claims 10 to 13, characterized in that: The binder resin includes one or more selected from epoxy resins, acrylic resins, and allyl resins.

15. The thermally conductive composition according to any one of claims 10 to 14, characterized in that: Contains curing agent.

16. The thermally conductive composition according to any one of claims 10 to 15, characterized in that: The monomer includes at least one selected from the group consisting of a diol monomer, an acrylic monomer, an epoxy monomer, and a maleimide monomer.

17. The thermally conductive composition according to any one of claims 10 to 16, characterized in that: Contains a free radical polymerization initiator.

18. The thermally conductive composition according to any one of claims 10 to 17, characterized in that: Contains silane coupling agent.

19. The thermally conductive composition according to any one of claims 10 to 18, characterized in that: Contains plasticizer.

20. A method for manufacturing a semiconductor package, characterized in that: include: A step of providing a semiconductor element on one surface of a substrate in such a manner that the other surface of the semiconductor element faces the one surface of the substrate; A step of applying a thermally conductive composition containing metal particles on a surface of one side of the semiconductor element; a step of disposing a heat sink so as to contact the thermally conductive composition and cover at least one side of the semiconductor element; and a step of heating a structure including the substrate, the semiconductor element, the thermally conductive composition and the heat sink, In the step of performing the heat treatment, the semiconductor element and the heat sink are bonded via a thermally conductive material including a particle connection structure formed by sintering of the metal particles.

21. The method for manufacturing a semiconductor package according to claim 20, wherein: The method further includes a step of drying the thermally conductive composition after the coating step and before the disposing step.

22. The method for manufacturing a semiconductor package according to claim 20 or 21, characterized in that: In the applying step, the thermally conductive composition is applied using a dispenser.

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