Laminate

Abstract

To provide a laminate capable of reducing warpage.SOLUTION: There is provided a laminate including a first member, a film adhesive, and a second member in this order, in which a film adhesive bonds a first member and a second member, the film adhesive being made of a thermosetting resin composition containing a filler, the film adhesive having a single-layer structure having a first surface and a second surface, and having a region in the vicinity of the first surface, that is a region in which a filler content decreases from a second surface side toward a first surface side.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laminate. [Background technology]

[0002] In recent years, a technology has become known in which components such as metal sheets are bonded together via a film-like adhesive to form a laminate for the purpose of heat dissipation and electrical conductivity of components of electronic devices, etc. Since it is difficult to bond electronic components and metal sheets with sufficient adhesive strength using ordinary adhesives, the use of a film-like adhesive made of a thermosetting adhesive composition has been investigated in order to improve adhesive strength (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-292908 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional film adhesives can cause warping in laminates due to factors such as differences in the thermal expansion coefficients between components and uneven temperature distribution due to heat generation in the components. Therefore, an object of the present invention is to provide a laminate that can reduce warping. [Means for solving the problem]

[0005] One aspect of the present invention relates to the following [1] to [8]. [1] A laminate comprising a first member, a film adhesive, and a second member in this order, the film adhesive bonds the first member and the second member together, the film-like adhesive is made of a resin composition that is thermosetting and contains a filler, and has a single-layer structure having a first surface and a second surface; A laminate having a region in the vicinity of the first surface of the film-like adhesive, in which the filler content decreases from the second surface side toward the first surface side. [2] A laminate comprising a first member, a film adhesive, and a second member in this order, the film adhesive bonds the first member and the second member together, the film-like adhesive is made of a resin composition that is thermosetting and contains a filler, and has a single-layer structure having a first surface and a second surface; A laminate having a region near the first surface of the film-like adhesive after heat curing, in which the filler content decreases from the second surface side toward the first surface side, when the film-like adhesive is cured by heating. [3] A laminate comprising a first member, an adhesive layer, and a second member in this order, the adhesive layer bonds the first member and the second member together, the adhesive layer is a resin layer obtained by curing at least a part of a thermosetting resin composition containing a filler, and has a single-layer structure having a first surface and a second surface, A laminate having a region in the vicinity of the first surface of the adhesive layer, in which the content of the filler decreases from the second surface side toward the first surface side. [4] The laminate according to [1] or [2], wherein the ratio of the thickness of the region to the total thickness of the film-like adhesive is 25% or less. [5] The laminate described in [3], wherein the ratio of the thickness of the region to the total thickness of the adhesive layer is 25% or less. [6] The laminate according to any one of [1] to [5], wherein the thickness of the region is 2 μm or less. [7] The laminate according to any one of [1] to [6], wherein the region is located at a position shallower than 2 μm in depth from the first surface. [8] The laminate according to any one of [1] to [7], wherein the content of the filler is 3 to 55 mass % based on the total mass of the resin composition. [9] The resin composition contains an acrylic rubber, The laminate according to any one of [1] to [8], wherein the content of the acrylic rubber is 50 to 85 mass % based on the total mass of the resin composition.

[10] The first member is made of at least one material selected from the group consisting of metal, glass, resin, and ceramic, The laminate according to any one of [1] to [9], wherein the second member is made of at least one material selected from the group consisting of metal, glass, resin, and ceramic. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a laminate capable of reducing warpage. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view schematically showing one embodiment of a laminate according to the present invention. [Figure 2] FIG. 2 is a cross-sectional view schematically showing the film adhesive in the laminate shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view schematically showing another embodiment of the film adhesive. [Figure 4] FIG. 4 is a cross-sectional view schematically showing an example of an adhesive film provided with the film-like adhesive shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. However, the present invention is not limited to the following embodiments. In the following embodiments, the components (including steps, etc.) are not essential unless specifically stated. The sizes of the components in each drawing are conceptual, and the relative size relationships between the components are not limited to those shown in each drawing.

[0009] The same applies to numerical values ​​and ranges in this specification, and do not limit the present invention. In this specification, numerical ranges indicated using "to" indicate ranges that include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in this specification, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in numerical ranges described in this specification, the upper or lower limit value of that numerical range may be replaced with a value shown in the Examples. In this specification, (meth)acrylate means acrylate or the corresponding methacrylate. The same applies to other similar expressions such as (meth)acryloyl group and (meth)acrylic copolymer.

[0010] <Laminate> 1 is a cross-sectional view schematically illustrating a laminate according to this embodiment. The laminate 10 shown in this figure includes, in this order, a first member 11, a film-like adhesive 1, and a second member 12. The film-like adhesive 1 bonds the first member 11 and the second member 12 together. <Film adhesive> FIG. 2 is a cross-sectional view schematically showing the film-like adhesive in the laminate shown in FIG. 1. The film-like adhesive 1 has a single-layer structure composed of a thermosetting resin composition containing a filler. The thickness of the film-like adhesive 1 may be 50 μm or less, for example, 40 μm or less, 30 μm or less, 20 μm or less, or 10 μm or less. When the thickness of the film-like adhesive 1 is 50 μm or less, the ratio of the region where the filler content decreases tends to increase relative to the thickness of the film-like adhesive, making it easier to achieve the effects of the present invention. There is no particular restriction on the lower limit of the thickness of the film-like adhesive 1, but it is, for example, 2 μm or more. When the thickness of the film-like adhesive 1 is 2 μm or more, the adhesive strength with the member tends to be easily maintained.

[0011] The film adhesive 1 has a region R1 near the first surface F1 where the filler content decreases from the second surface F2 toward the first surface F1 (the region whose thickness is indicated by the arrow in the enlarged view shown in FIG. 2). At this time, the film adhesive 1 may be either uncured or cured.

[0012] Region R1 is composed of a plurality of fillers 1f and a resin component. In region R1, the filler content may decrease continuously or stepwise. The relatively low filler content in region R1 located near first surface F1 means that a region with a relatively high resin component content (resin-rich region) is locally formed in the thickness direction near first surface F1, while being continuously expanded in the plane direction. Region R1 is denser and more flexible in the plane direction than other regions, which is presumably why stress can be alleviated and warpage of the laminate can be reduced. First surface F1 may be the surface on the first member 11 side or the surface on the second member 12 side.

[0013] Region R1 is located at a depth of less than 2 μm from the first surface F1, although this varies depending on the thickness of the film adhesive 1. In other words, "vicinity of the first surface F1" in this embodiment refers to a region that is less than 2 μm deep from the first surface F1. It is sufficient that region R1 exists near the first surface F1; for example, a region with a high filler content may exist locally on the first surface F1.

[0014] The presence and thickness of region R1 can be confirmed, for example, by impacting a slurry containing abrasive grains against the first surface F1 at high speed and measuring the wear rate. Alternatively, it may be confirmed by measurement using a rigid pendulum-type physical property tester. In particular, measuring the wear rate by impacting a slurry containing abrasive grains at high speed can sufficiently reduce the thermal effects on the film-like adhesive 1. The presence and thickness of region R1 can also be confirmed after the film-like adhesive 1 has been cured by heating. Specifically, a thermally cured film-like adhesive and a thermally cured film-like adhesive from which the vicinity of the first surface F1 has been physically removed are prepared, and the compositional difference between the two can be determined by changing the ATR crystal and changing the penetration depth. The presence and thickness of region R1 can also be confirmed by observing the cross section of the laminate 10.

[0015] The thickness of region R1 may be 0.1 μm or more, 0.3 μm or more, 0.5 μm or more, 0.8 μm or more, or 1 μm or more, from the viewpoint of further reducing warpage of the laminate. The thickness of region R1 may be 2 μm or less, 1.5 μm or less, or 1 μm or less, from the viewpoint of further improving the mechanical strength of the laminate. The thickness of region R1 can be adjusted by adjusting the air speed and drying temperature when forming the film-like adhesive 1.

[0016] The ratio of the thickness of region R1 to the overall thickness of film adhesive 1 may be 3% or more, 4% or more, or 5% or more, from the viewpoint of further reducing warpage of the laminate. The ratio of the thickness of region R1 to the overall thickness of film adhesive 1 may be 25% or less, 20% or less, or 15% or less, from the viewpoint of further improving the mechanical strength of the laminate.

[0017] As shown in FIG. 3, the film adhesive may also have a region R2 similar to region R1 formed near the second surface F2. The film adhesive 1A shown in FIG. 3 has the same configuration as the film adhesive 1, except that it further includes region R2, a region near the second surface F2, in which the filler content decreases from the first surface F1 toward the second surface F2. Region R2 is located at a depth of less than 2 μm from the second surface F2. In other words, "near the second surface F2" refers to a region shallower than 2 μm from the second surface F2. It is sufficient that region R2 is located near the second surface F2; for example, a region with a high filler content may be locally present on the second surface F2. The thickness of region R2 can be effectively adjusted by adjusting the air speed and drying temperature when forming the film adhesive 1. It can also be adjusted by changing the support film that the film adhesive 1 comes into contact with during drying. The thickness of region R2 and the ratio of the thickness of region R2 to the total thickness of the film-like adhesive 1 may be within the same range as region R1 described above.

[0018] The total thickness of regions R1 and R2 may be 0.5 μm or more, 0.3 μm or more, 0.5 μm or more, 0.8 μm or more, 1 μm or more, 1.2 μm or more, or 1.4 μm or more, from the viewpoint of further reducing warpage of the laminate. The total thickness of regions R1 and R2 may be 4 μm or less, 3 μm or less, 2 μm or less, or 1.5 μm or less, from the viewpoint of further improving the mechanical strength of the laminate.

[0019] The ratio of the total thickness of regions R1 and R2 to the total thickness of the film-like adhesive 1 may be 6% or more, 7% or more, or 8% or more, from the viewpoint of further reducing warpage of the laminate. The ratio of the total thickness of regions R1 and R2 to the total thickness of the film-like adhesive 1 may be 45% or less, 40% or less, or 35% or less, from the viewpoint of further improving the mechanical strength of the laminate.

[0020] The film-like adhesive 1 is composed of an adhesive composition containing (A) a thermosetting resin component and (B) a filler. The film-like adhesive 1 may be in a semi-cured (B-stage) state or a cured (C-stage) state. In one embodiment, the (A) thermosetting resin component may include (A1) a thermosetting resin, (A2) a curing agent, and (A3) an elastomer.

[0021] When the film-like adhesive 1 is in a cured (C-stage) state, at least a portion of the film-like adhesive 1 is cured, and the entire film-like adhesive 1 may be cured. When the film-like adhesive 1 is in a cured (C-stage) state, the laminate can be said to comprise a first member, an adhesive layer, and a second member, in this order. That is, another embodiment of the present invention is a laminate comprising a first member, an adhesive layer, and a second member, in this order, wherein the adhesive layer bonds the first member and the second member, the adhesive layer is a resin layer formed by curing at least a portion of a thermosetting resin composition containing a filler, and has a single-layer structure having a first surface and a second surface, and the adhesive layer has a region near the first surface, in which the filler content decreases from the second surface side toward the first surface side. Note that since the adhesive layer is a cured film-like adhesive, the configuration of the adhesive layer can be applied by substituting "adhesive" in the description of the film-like adhesive described above.

[0022] (A1) Component: Thermosetting resin From the viewpoint of adhesiveness, the component (A1) may be an epoxy resin. Any epoxy resin having an epoxy group in the molecule may be used without particular limitation. Examples of epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, bisphenol A novolac epoxy resins, bisphenol F novolac epoxy resins, stilbene epoxy resins, triazine skeleton-containing epoxy resins, fluorene skeleton-containing epoxy resins, triphenolmethane epoxy resins, biphenyl epoxy resins, xylylene epoxy resins, biphenyl aralkyl epoxy resins, naphthalene epoxy resins, polyfunctional phenols, and diglycidyl ether compounds of polycyclic aromatics such as anthracene. These may be used alone or in combination of two or more. Among these, the component (A1) may be a cresol novolac epoxy resin, a phenol novolac epoxy resin, a bisphenol F epoxy resin, or a bisphenol A epoxy resin, from the viewpoint of film tackiness, flexibility, and the like.

[0023] The epoxy equivalent of the epoxy resin is not particularly limited, but may be 90 to 300 g / eq or 110 to 290 g / eq. When the epoxy equivalent of the epoxy resin is within this range, the film adhesive tends to maintain its bulk strength while ensuring its fluidity.

[0024] Component (A2): Hardener Component (A2) may be a phenolic resin that can serve as a curing agent for epoxy resins. Any phenolic resin can be used without particular limitation as long as it has a phenolic hydroxyl group in the molecule. Examples of phenolic resins include novolak-type phenolic resins obtained by condensing or co-condensing phenols such as phenol, cresol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol and / or naphthols such as α-naphthol, β-naphthol, and dihydroxynaphthalene with a compound having an aldehyde group such as formaldehyde under an acidic catalyst; phenol aralkyl resins and naphthol aralkyl resins synthesized from phenols such as allylated bisphenol A, allylated bisphenol F, allylated naphthalenediol, phenol novolak, and / or naphthols with dimethoxyparaxylene or bis(methoxymethyl)biphenyl; and the like. These resins may be used alone or in combination of two or more. Among these, the phenol resin may be a phenol novolac type phenol resin or a naphthol aralkyl resin.

[0025] The hydroxyl equivalent of the phenolic resin may be 70 g / eq or more, or 70 to 300 g / eq. If the hydroxyl equivalent of the phenolic resin is 70 g / eq or more, the storage modulus of the film tends to be further improved, and if it is 300 g / eq or less, defects due to the generation of foaming, outgassing, etc. can be prevented.

[0026] From the viewpoint of curability, the ratio of the epoxy equivalent of the epoxy resin to the hydroxyl equivalent of the phenolic resin (epoxy equivalent of the epoxy resin / hydroxyl equivalent of the phenolic resin) may be 0.30 / 0.70 to 0.70 / 0.30, 0.35 / 0.65 to 0.65 / 0.35, 0.40 / 0.60 to 0.60 / 0.40, or 0.45 / 0.55 to 0.55 / 0.45. When the equivalent ratio is 0.30 / 0.70 or more, more sufficient curability tends to be obtained. When the equivalent ratio is 0.70 / 0.30 or less, excessive viscosity can be prevented, and more sufficient fluidity can be obtained.

[0027] The total amount of the (A1) and (A2) components may be 5 to 50 parts by mass, 10 to 40 parts by mass, or 15 to 30 parts by mass, based on 100 parts by mass of the total amount of the (A) component. When the total amount of the (A1) and (A2) components is 5 parts by mass or more, the elastic modulus tends to be improved by crosslinking. When the total amount of the (A1) and (A2) components is 50 parts by mass or less, the film handleability tends to be maintained.

[0028] (A3) Component: Elastomer The component (A3) may be an acrylic rubber having, as a main component, structural units derived from a (meth)acrylic acid ester. The content of structural units derived from a (meth)acrylic acid ester in the component (A3) may be, for example, 70% by mass or more, 80% by mass or more, or 90% by mass or more, based on the total amount of structural units. The acrylic rubber may contain structural units derived from a (meth)acrylic acid ester having a crosslinkable functional group such as an epoxy group, an alcoholic or phenolic hydroxyl group, or a carboxyl group.

[0029] The glass transition temperature (Tg) of component (A3) may be -50 to 50°C or -30 to 30°C. When the Tg of component (A3) is -50°C or higher, it tends to be possible to prevent the flexibility of the adhesive from becoming too high. This makes it easier to cut the film-like adhesive during wafer dicing, and makes it possible to prevent the occurrence of burrs. When the Tg of component (A3) is 50°C or lower, it tends to be possible to suppress a decrease in the flexibility of the adhesive. This tends to make it easier to sufficiently fill voids when the film-like adhesive is attached to a wafer. It also makes it possible to prevent chipping during dicing due to a decrease in wafer adhesion. Here, the glass transition temperature (Tg) refers to a value measured using a DSC (differential scanning calorimeter) (e.g., Thermo Plus 2, manufactured by Rigaku Corporation).

[0030] The weight-average molecular weight (Mw) of component (A3) may be 100,000 to 3,000,000 or 200,000 to 2,000,000. When the Mw of component (A3) is within this range, it is possible to appropriately control the film-forming properties, film strength, flexibility, tackiness, etc., and also to achieve excellent reflowability and improved embeddability. Here, Mw refers to a value measured by gel permeation chromatography (GPC) and converted using a calibration curve based on standard polystyrene.

[0031] Commercially available products of the component (A3) include, for example, improved SG-P3 and SG-80H (both manufactured by Nagase ChemteX Corporation).

[0032] The content of component (A3) may be 50 to 95 parts by mass, 60 to 90 parts by mass, or 70 to 85 parts by mass, based on 100 parts by mass of the total mass of component (A). When component (A3) is an acrylic rubber, the content of the acrylic rubber may be, for example, 50 to 85% by mass, 55 to 80% by mass, or 60 to 80% by mass, based on the total mass of the adhesive composition. A content of 50% by mass or more facilitates the formation of region R1, while a content of 85% by mass or less facilitates the maintenance of workability during the production of the film-like adhesive 1.

[0033] In another embodiment, the (A) thermosetting resin component may contain an elastomer having a crosslinkable functional group such as an epoxy group, an alcoholic or phenolic hydroxyl group, or a carboxyl group, and a curing agent capable of reacting with the crosslinkable functional group. Examples of a combination of an elastomer having a crosslinkable functional group and a curing agent capable of reacting with the crosslinkable functional group include a combination of an acrylic rubber having an epoxy group and a phenolic resin.

[0034] (B) Component: Filler Component (B) may be either an inorganic filler or an organic filler. Examples of inorganic fillers include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisker, boron nitride, and silica. These may be used alone or in combination of two or more. Among these, component (B) may be silica from the viewpoint of adjusting the melt viscosity. Examples of organic fillers include carbon, rubber-based fillers, silicone-based fine particles, polyamide fine particles, and polyimide fine particles. The shape of component (B) is not particularly limited, but may be spherical.

[0035] From the viewpoint of fluidity, the average particle size of component (B) may be 0.01 to 1 μm, 0.01 to 0.8 μm, or 0.03 to 0.5 μm, where the average particle size refers to a value determined by conversion from the BET specific surface area.

[0036] The content of component (B) may be 0.1 to 50 parts by mass, 0.1 to 30 parts by mass, or 0.1 to 20 parts by mass, relative to 100 parts by mass of the total mass of component (A). Based on the total mass of the adhesive composition, the content of component (B) is, for example, 3 to 55% by mass, or may be 5 to 50% by mass, or 7 to 40% by mass. A content of 3% by mass or more has the effect of maintaining the mechanical strength of the film-like adhesive 1, while a content of 55% by mass or less has the effect of maintaining a good appearance of the film-like adhesive 1.

[0037] The film-like adhesive (adhesive composition) may further contain (C) a coupling agent, (D) a curing accelerator, and the like.

[0038] Component (C): Coupling agent Component (C) may be a silane coupling agent. Examples of silane coupling agents include γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, and 3-(2-aminoethyl)aminopropyltrimethoxysilane. These may be used alone or in combination of two or more.

[0039] Component (D): Curing accelerator The component (D) is not particularly limited, and a commonly used component can be used. Examples of the component (D) include imidazoles and their derivatives, organic phosphorus compounds, secondary amines, tertiary amines, and quaternary ammonium salts. These may be used alone or in combination of two or more. Among these, from the perspective of reactivity, the component (D) may be imidazoles and their derivatives. Examples of the imidazoles include 2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-methylimidazole. These may be used alone or in combination of two or more.

[0040] The film adhesive 1 may further contain other components. Examples of other components include leveling agents, pigments, ion scavengers, antioxidants, etc. The content of component (C), component (D), and other components may be 0 to 30 parts by mass per 100 parts by mass of the total mass of component (A).

[0041] The film-like adhesive 1 can be formed by applying the adhesive composition to a support film. When using a varnish of the adhesive composition (adhesive varnish), components (A) and (B) and other components added as needed are mixed in a solvent, the mixture is mixed or kneaded to prepare an adhesive varnish, the adhesive varnish is applied to a support film 5, and the solvent is removed by drying, thereby obtaining the film-like adhesive 1. The adhesive sheet 100 shown in FIG. 4 is composed of a support film 5 and a film-like adhesive 1 provided on the surface of the support film 5.

[0042] When forming the film adhesive 1 from a coating of adhesive varnish, the solvent is removed by drying while air is blown onto the surface of the coating, thereby forming a region R1 near the first surface F1. The speed of the air flowing parallel to the upper surface of the coating is, for example, 3 to 20 m / sec. When this speed is 3 m / sec or more, the drying of component (A) on the surface of the coating that is exposed to the air is promoted, which has the effect of facilitating the formation of a region R1 with sufficient thickness near the first surface F1 of the film adhesive 1. On the other hand, when the speed is 20 m / sec or less, the appearance of the coating surface is easily maintained.

[0043] The drying temperature of the adhesive varnish is, for example, 25 to 150° C., and may be 50 to 145° C. A drying temperature of 50° C. or higher provides the effect of easily maintaining productivity, while a drying temperature of 150° C. or lower provides the effect of easily suppressing poor appearance.

[0044] The support film 5 is not particularly limited as long as it can withstand the above-mentioned heat drying, and may be, for example, a polyester film, a polypropylene film, a polyethylene terephthalate film, a polyimide film, a polyetherimide film, a polyethylene naphthalate film, a polymethylpentene film, etc. The support film 5 may be a multilayer film made by combining two or more types of film, and may have a surface treated with a silicone-based, silica-based, or other mold release agent. The thickness of the support film 5 may be, for example, 10 to 200 μm or 20 to 170 μm.

[0045] Mixing or kneading can be carried out using a dispersing machine such as a conventional stirrer, a mortar and pestle, a three-roll mill, or a ball mill, and an appropriate combination of these. The solvent used to prepare the adhesive varnish is not limited as long as it can uniformly dissolve, knead, or disperse each component, and conventionally known solvents can be used. Examples of such solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, as well as dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, toluene, and xylene. Methyl ethyl ketone, cyclohexanone, and the like may be used as the solvent because of their fast drying rate and low cost. Known methods can be used to apply the adhesive varnish to the support film, including, for example, knife coating, roll coating, spray coating, gravure coating, bar coating, and curtain coating.

[0046] The surface tension of the adhesive varnish is, for example, 27 to 44 mN / m, and may be 28 to 40 mN / m or 28 to 38 mN / m. Having this value within the above range facilitates the production of a film with good appearance and also facilitates maintaining workability during production. The surface tension of the adhesive varnish refers to a value measured by the hanging drop method under windless conditions at room temperature of 22 to 28°C and humidity of 40 to 60%. The surface tension of the adhesive varnish can be adjusted, for example, by blending a leveling agent into the adhesive varnish.

[0047] <First member, second member> Examples of materials constituting the first member 11 and the second member 12 include metal, glass, resin, ceramic, etc. That is, the first member 11 may be made of at least one material selected from the group consisting of metal, glass, resin, and ceramic, and the second member 12 may be made of at least one material selected from the group consisting of metal, glass, resin, and ceramic.

[0048] Examples of metals include iron, lead, copper, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, and aluminum. These metals may be alloys. Examples of resins include glass epoxy resin, phenolic resin, melamine resin, cyanoester resin, and bismaleimide resin. Examples of ceramics include alumina, zirconia, silicon carbide, silicon nitride, silicon carbide, silicon nitride, ferrite, and boron nitride.

[0049] The first member 11 and the second member 12 may be made of the same material or different materials. When the hardness of the first member 11 and the hardness of the second member 12 are different, the first surface F1 of the film adhesive 1 may be the surface on the harder member side, from the viewpoint of reducing warping of the laminate 10. In this specification, "hardness" refers to Mohs hardness.

[0050] The shapes of the first member 11 and the second member 12 are not particularly limited and may be, for example, film-like. When the first member 11 and the second member 12 are film-like, the thickness of the first member 11 and the second member 12 may be independently 20 to 2500 μm. [Example]

[0051] The present invention will be specifically described below based on examples and comparative examples, but the present invention is not limited to the following examples.

[0052] (Examples 1 to 3) [Preparation of film adhesive] <Preparing the adhesive varnish> The acrylic rubber solution shown in Table 1 was used as the adhesive varnish. The numerical values ​​relating to the composition shown in Table 1 refer to the parts by mass of the solid content of the acrylic rubber solution.

[0053] (A1) Epoxy resin N-500P-10 (product name, manufactured by DIC Corporation, o-cresol novolac epoxy resin, epoxy equivalent: 203 g / eq) (A2) Hardener (phenolic resin) MEH-7800M (product name, manufactured by Meiwa Chemical Co., Ltd., phenol novolac type phenolic resin, hydroxyl equivalent: 175 g / eq, softening point: 61 to 90°C) SG-P3 Improved 1 (product name, manufactured by Nagase ChemteX Corporation) (B) Inorganic filler R972 (product name, manufactured by Nippon Aerosil Co., Ltd., silica particles, average particle size: 0.016 μm) (C) Coupling Agent Z-6119 (product name, Dow-Toray Industries, Inc., 3-ureidopropyltriethoxysilane) A-189 (trade name, manufactured by Nippon Unicar Co., Ltd., γ-mercaptopropyltrimethoxysilane) (D) Curing accelerator 2PZ-CN (product name, manufactured by Shikoku Chemicals Corporation, 1-cyanoethyl-2-phenylimidazole)

[0054] <Preparation of film adhesive> An adhesive varnish having the composition shown in Table 1 was filtered through a 100-mesh filter and vacuum-degassed. The surface tension (hanging drop method) of the resulting adhesive varnish was 36 mN / m. A 38 μm-thick polyethylene terephthalate (PET) film with a release treatment was prepared as the substrate film, and the adhesive varnish after vacuum degassing was applied to the PET film. The amount of adhesive varnish applied was adjusted so that the thickness after drying would be 10 μm. A film-like adhesive in a B-stage state was obtained by drying at the temperature shown in Table 1 while blowing air at a speed of 3 m / s or more parallel to the top surface of the applied adhesive varnish.

[0055] Region Thickness The film adhesive was heated to 170°C for 3 hours to cure. The cured film adhesive was then fixed to the sample stage of an atomic force microscope (SPM400, Hitachi High-Tech Corporation). A cantilever (Hitachi High-Tech Corporation, product name SI-DF-40, material: Si, spring constant: 40 N / m, tip curvature radius: 8 nm) was placed on the cantilever holder and pressed against the film adhesive from surface F1 (or F2) within the operating range of the scanner installed in the direction of the film adhesive's thickness. A force curve was obtained. The indentation depth was set to be greater than the thickness of region R1 (or R2) but less than the operating range of the scanner. The force curve for the region where the cantilever was pressed into the sample was converted into a curve showing the relationship between the elastic modulus and the distance from surface F1 (or F2) (cantilever indentation depth) using Hertz contact theory. The cantilever spring constant was corrected, and the cantilever's condition was monitored to confirm that no obvious wear or deterioration was observed. The distance from the surface F1 (or F2) when the obtained curve reached saturation was read as the thickness of region R1 (or R2). The above measurement was performed 20 times, and after excluding clearly abnormal points, the average value of the total thickness of regions R1 and R2 was calculated. The average value of the total thickness of regions R1 and R2 is shown in Table 1 as the thickness of the region.

[0056] [Change in warpage amount] Forty semiconductor chips (4 mm x 12 mm x 30 μm) were attached to a glass epoxy resin substrate (74 mm x 80 mm x 105 μm) using the film-like adhesive prepared in each example at 120°C, 0.1 MPa, and 1 second to obtain a laminate. The laminate was then heated in a heating furnace. The laminate was heated from 25°C to 90°C over 5 minutes, held at 90°C for 5 minutes, raised from 90°C to 140°C over 2 minutes, held at 140°C for 35 minutes, and cooled from 140°C to 80°C over 10 minutes. The amount of warpage of the laminate before and after heating in the heating furnace was measured using the shadow moiré method to determine the change in warpage. The measurement results are shown in Table 1.

[0057] [Table 1] [Explanation of symbols]

[0058] 1, 1A...film adhesive, 5...support film, 10...laminate, 11...first member, 12...second member, F1...first surface, F2...second surface, R1, R2...regions.

Claims

1. A laminate comprising a first member, a film adhesive, and a second member in this order, the film adhesive bonds the first member and the second member together, the film-like adhesive is made of a resin composition that is thermosetting and contains a filler, and has a single-layer structure having a first surface and a second surface; A laminate having a region in the vicinity of the first surface of the film-like adhesive, in which the filler content decreases from the second surface side toward the first surface side.

2. A laminate comprising a first member, a film adhesive, and a second member in this order, the film adhesive bonds the first member and the second member together, the film-like adhesive is made of a resin composition that is thermosetting and contains a filler, and has a single-layer structure having a first surface and a second surface; A laminate having a region near the first surface of the film-like adhesive after heat curing, in which the filler content decreases from the second surface side toward the first surface side, when the film-like adhesive is cured by heating.

3. A laminate including a first member, an adhesive layer, and a second member in this order, the adhesive layer bonds the first member and the second member together, the adhesive layer is a resin layer obtained by curing at least a part of a thermosetting resin composition containing a filler, and has a single-layer structure having a first surface and a second surface, A laminate having a region in the vicinity of the first surface of the adhesive layer, in which the content of the filler decreases from the second surface side toward the first surface side.

4. 3. The laminate according to claim 1, wherein the ratio of the thickness of said region to the total thickness of said film adhesive is 25% or less.

5. The laminate according to claim 3 , wherein the ratio of the thickness of said region to the total thickness of said adhesive layer is 25% or less.

6. The laminate according to any one of claims 1 to 3, wherein the thickness of the region is 2 µm or less.

7. The laminate according to any one of claims 1 to 3, wherein the region is located at a position shallower than 2 µm in depth from the first surface.

8. The laminate according to any one of claims 1 to 3, wherein the content of the filler is 3 to 55 mass% based on the total mass of the resin composition.

9. The resin composition contains an acrylic rubber, The laminate according to any one of claims 1 to 3, wherein the content of the acrylic rubber is 50 to 85 mass% based on the total mass of the resin composition.

10. the first member is made of at least one material selected from the group consisting of metal, glass, resin, and ceramic, 4. The laminate according to claim 1, wherein the second member is made of at least one material selected from the group consisting of metal, glass, resin, and ceramic.

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