WO2022097443A1

WO2022097443A1 - Adhesive film, support-sheet-equipped adhesive film, and structure

Info

Publication number: WO2022097443A1
Application number: PCT/JP2021/038058
Authority: WO
Inventors: 功市川; 毅朗吉延
Original assignee: リンテック株式会社
Priority date: 2020-11-04
Filing date: 2021-10-14
Publication date: 2022-05-12
Also published as: KR20230104114A; TW202229494A; CN116323193A; JPWO2022097443A1

Abstract

An adhesive film containing a thermally conductive filler (A) having a two-dimensional crystal structure, an epoxy component (B), a curing agent (C), and a binder polymer (D), the adhesive film 1 being such that at least one of the epoxy component (B) and the curing agent (C) has a conjugated mesogenic skeleton. This adhesive film 1 exhibits exceptional thermal conductivity.

Description

Adhesive film, adhesive film with support sheet, and structure

The present invention relates to an adhesive film having excellent thermal conductivity and a method for manufacturing the same, an adhesive film with a support sheet, and a structure and a method for manufacturing the same.

Conventionally, in electronic devices such as thermoelectric conversion devices, photoelectric conversion devices, and semiconductor devices such as large-scale integrated circuits, heat-dissipating members having thermal conductivity have been used in order to dissipate heat generated. For example, as a method for efficiently dissipating heat generated from a semiconductor device to the outside, a liquid heat conductive adhesive having excellent heat conductivity, which is highly filled with an inorganic filler, is used for bonding the semiconductor device and a heat sink. Alternatively, a sheet-shaped heat radiating member (film, sheet) having excellent thermal conductivity is provided between the semiconductor device and the heat sink.

As exemplified in Patent Document 1, the above-mentioned film or sheet is coated with a coating liquid of a heat-dissipating material containing an adhesive resin, an inorganic filler, a curing agent and a solvent on a release sheet or a base material. Manufactured by drying. As the inorganic filler, silica, alumina, glass, titanium oxide and the like are used.

Japanese Unexamined Patent Publication No. 2015-67713

However, conventional films and sheets containing inorganic fillers may not always obtain the desired thermal conductivity. Therefore, those having further excellent thermal conductivity are required. Here, when a conventional film or sheet containing an inorganic filler is highly filled with the inorganic filler in order to obtain high thermal conductivity, it becomes mechanically brittle, its flexibility is lowered, and broken debris is generated during use. In some cases, problems in the process may occur. In addition, the surface roughness of the sheet-shaped heat-dissipating member becomes large, which makes it difficult for tack to occur, and when temporary adhesiveness cannot be obtained when the sheet-shaped heat-dissipating member is attached to the adherend, or when the sheet-shaped heat-dissipating member is attached to the adherend. It became easy to entrain air when it was attached to the sheet, and there were cases where many voids were formed at the adhesive interface between the sheet-shaped heat dissipation member and the adherend. Due to the higher filling, there are many interfaces between the inorganic filler and other organic material components such as adhesive resin inside the sheet-shaped heat dissipation member. Therefore, if peeling occurs at the interface, the sheet-shaped heat dissipation occurs. Many voids were formed inside the member, which may reduce the thermal conductivity.

By the way, in recent years, in a wide range of fields including the electronics field and the fuel cell field, a composite resin containing graphene having excellent electrical properties, thermal properties, and optical properties instead of the conventional inorganic filler. Materials have been proposed. When graphene is dispersed in a resin and used as a composite resin material, it is necessary to uniformly disperse graphene in the resin. However, it is difficult to uniformly disperse graphene in the resin from the viewpoint of the cohesiveness of graphene and the affinity with the resin. If the dispersion is insufficient, there is a problem that the thermal conductivity varies, and an adhesive film in which graphene is dispersed in a binder resin as a heat-dissipating filler has not yet been put into practical use.

The present invention has been made in view of such an actual situation, and an object of the present invention is to provide an adhesive film having excellent thermal conductivity and a method for producing the same, an adhesive film with a support sheet, and a structure and a method for producing the same. do.

In order to achieve the above object, firstly, the present invention comprises a thermally conductive filler (A) having a two-dimensional crystal structure, an epoxy component (B), a curing agent (C), and a binder polymer (D). Provided is an adhesive film containing the above, wherein at least one of the epoxy component (B) and the curing agent (C) has a π-conjugated mesogen skeleton (Invention 1).

Secondly, the present invention provides an adhesive film containing a thermally conductive filler (A) having a two-dimensional crystal structure, an epoxy component (B) having a π-conjugated mesogen skeleton, and a binder polymer (D). (Invention 2).

In the adhesive film according to the above inventions (Inventions 1 and 2), the thermally conductive fillers (A) having many π electrons easily come close to each other due to interaction, and further, due to their shape, have a large specific surface area, so that they easily come into contact with each other. .. Further, due to the interaction between the π electrons of the heat conductive filler (A) and the π electrons of the epoxy component (B) and / or the curing agent (C), the heat conductive filler (A) is made of an adhesive resin. It disperses well in the composition and thus in the adhesive film, and aggregation and segregation are suppressed. Due to these actions, in the adhesive film, a heat conductive path by the heat conductive filler (A) is easily formed, and excellent heat conductivity is exhibited.

In the above inventions (Inventions 1 and 2), the content of the thermally conductive filler (A) having the two-dimensional crystal structure is preferably 5% by mass or more and 60% by mass or less (Invention 3).

In the above inventions (Inventions 1 to 3), it is preferable that the thermally conductive filler (A) having the two-dimensional crystal structure is graphene (Invention 4).

In the above inventions (Inventions 1 to 4), the absorption intensity peak value of the D band having a wave number of 1250 cm ^-1 with respect to the absorption intensity peak value (IG) of the _G band having a wave number of 1570 cm ^-1 in the absorption spectrum obtained by Raman measurement. The ratio ( _D / G) of (ID) is preferably 0.5 or less (Invention 5).

In the above inventions (Inventions 1 to 5), it is preferable that the epoxy component (B) has a naphthalene skeleton or a biphenyl skeleton as the π-conjugated mesogen skeleton (Invention 6).

In the above inventions (Inventions 1 to 6), it is preferable that the curing agent (C) is a phenolic curing agent having a biphenyl skeleton as the π-conjugated mesogen skeleton (Invention 7).

In the above inventions (inventions 1 to 7), it is preferable that the invention is hot-pressed (invention 8).

Thirdly, in the present invention, after mixing the thermally conductive filler (A) having a two-dimensional crystal structure and the binder polymer (D) in a solvent, at least one of the components is a π-conjugated mesogen skeleton. An adhesive resin composition is obtained by mixing the epoxy component (B) and the curing agent (C) having the above, and the obtained adhesive resin composition is formed into a film shape. (Invention 9).

Fourth, in the present invention, an epoxy component (B) having a π-conjugated mesogen skeleton after mixing a thermally conductive filler (A) having a two-dimensional crystal structure and a binder polymer (D) in a solvent. ) Is mixed to obtain an adhesive resin composition, and the obtained adhesive resin composition is formed into a film shape (Invention 10).

In the above inventions (Inventions 9 and 10), it is preferable to form the adhesive resin composition into a film and then heat-press it (Invention 11).

Sixth, the present invention provides an adhesive film with a support sheet including the adhesive film (inventions 1 to 8) and a support sheet laminated on at least one surface side of the adhesive film (invention 12).

Seventh, the present invention provides a structure in which at least a part of the first member and at least a part of the second member are joined via a cured body of the adhesive film (invention 1 to 8). (Invention 13).

In the above invention (Invention 13), it is preferable that the first member is a semiconductor element and the second member is a semiconductor element or a substrate (Invention 14).

Eighth, in the present invention, at least a part of the first member is attached to at least a part of the second member via the adhesive film (inventions 1 to 8), and then the adhesive film is heat-treated. The present invention provides a method for producing a structure in which at least a part of a first member and at least a part of a second member are bonded via a cured body by forming a cured body (Invention 15). ..

The adhesive film, the adhesive film with a support sheet, and the structure according to the present invention are excellent in thermal conductivity. Further, according to the method for producing an adhesive film according to the present invention, it is possible to produce an adhesive film having excellent thermal conductivity. Further, according to the method for manufacturing a structure according to the present invention, it is possible to manufacture a structure having excellent thermal conductivity.

It is sectional drawing of the adhesive film with a support sheet which concerns on one Embodiment of this invention. It is sectional drawing of the structure which concerns on one Embodiment of this invention. It is a graph which shows the result of having performed the Raman measurement about the adhesive film of Example 1. It is a graph which shows the result of having performed the Raman measurement about the adhesive film of the comparative example 2.

Hereinafter, embodiments of the present invention will be described.
[Adhesive film]
The adhesive film according to the present embodiment first contains a thermally conductive filler (A) having a two-dimensional crystal structure, an epoxy component (B), a curing agent (C), and a binder polymer (D). Then, at least one of the epoxy component (B) and the curing agent (C) has a π-conjugated mesogen skeleton, or secondly, it is π-conjugated with a thermally conductive filler (A) having a two-dimensional crystal structure. It contains an epoxy component (B) having a system mesogen skeleton and a binder polymer (D). The composition containing each of the above components may be hereinafter referred to as "adhesive resin composition R".

The thermally conductive filler (A) having a two-dimensional crystal structure is a substance in which many strong double bonds are present and excellent thermal conductivity is exhibited via phonons. Further, the thermally conductive filler (A) having many double bonds has many π electrons. Due to this interaction of π electrons, the thermally conductive fillers (A) are likely to be close to each other, and since the specific surface area is large due to the shape thereof, the thermally conductive fillers (A) are likely to come into contact with each other. As a result, a heat conduction path that conducts heat is easily formed in the adhesive film, and excellent heat conductivity can be exhibited even with a small amount of addition. Therefore, when the heat conductive filler (A) is used, excellent heat conductivity can be obtained without highly filling the adhesive film with the heat conductive filler (A).

Further, the thermally conductive filler (A) having a two-dimensional crystal structure has flexibility in itself due to its shape. Therefore, the adhesive film containing the heat conductive filler (A) has excellent flexibility. Moreover, since it is not necessary to highly fill the thermally conductive filler (A) as described above, the adhesive film is prevented from becoming mechanically brittle, and excellent mechanical toughness is exhibited.

If the adhesive film has excellent flexibility, it becomes difficult for air to be entrained when the adhesive film is attached to the adherend, and it is possible to suppress the formation of voids at the interface between the adhesive film and the adherend, and to reduce the contact area between the adhesive film and the adherend. Can be made larger. That is, it is possible to suppress the increase in thermal resistance due to the voids at the interface between the adhesive film and the adherend, and it is possible to improve the thermal conductivity between the adhesive film and the adherend. Further, if the adhesive film is prevented from becoming mechanically brittle as described above, the probability of occurrence of process defects such as generation of broken debris during use is reduced.

The thermally conductive filler (A) having a two-dimensional crystal structure is excellent in thermal conductivity as described above, but has a chemically stable structure and has no polarity due to its symmetry, so that it is a solvent. Difficult to disperse in medium or polymer materials. In this embodiment, the epoxy component (B) and / or the curing agent (C) has a π-conjugated mesogen skeleton, and this π-conjugated mesogen skeleton has many π electrons. As mentioned above, the thermally conductive filler (A) also has many π electrons. Due to the interaction between the π electrons of the heat conductive filler (A) and the π electrons of the epoxy component (B) and / or the curing agent (C), the heat conductive filler (A) is an adhesive resin composition. It disperses well in R and eventually in the adhesive film, and aggregation and segregation are suppressed. When the heat conductive filler (A) is well dispersed in this way, the heat conduction path is more easily formed, and the heat conductivity of the heat conductive filler (A) becomes more excellent.

Here, as described above, when a conventional inorganic filler is highly filled in order to obtain desired thermal conductivity, the surface roughness of the adhesive film becomes large, tack is difficult to develop, and the adhesive characteristics deteriorate. Further, there is a problem that the mechanical strength is lowered. On the other hand, since the heat conductive filler (A) in the present embodiment can obtain high heat conductivity without being highly filled as described above, the surface roughness of the adhesive film can be lowered, thereby lowering the surface roughness. Appropriate adhesive strength (temporary adhesiveness) can be exhibited. In addition, even after curing, it exhibits excellent adhesive properties, particularly excellent shear adhesive force, and has high adhesive reliability.

In addition, the conventional liquid heat conductive adhesive highly filled with an inorganic filler does not have stable thickness, and when used as an adhesive in a semiconductor device or the like, the device performance as designed may not be exhibited. The characteristics differed from device to device, and it was difficult to obtain stable quality products. By containing the binder polymer (D), the adhesive film according to the present embodiment is imparted with film-forming properties, has a film shape with high thickness accuracy, and has excellent stability of characteristics. Therefore, by using the adhesive film according to the present embodiment in a semiconductor device or the like, it is possible to manufacture a film having stable quality.

1. 1. Each component (1) Thermally conductive filler (A)
The adhesive film according to this embodiment contains a heat conductive filler (A) having a two-dimensional crystal structure. Here, the "thermally conductive filler having a two-dimensional crystal structure" has a structural periodicity in the two-dimensional direction and has a layer having a thickness of a single atom, and is composed of only the layer or the said layer. It means that the layers are laminated from two layers to several hundred layers by the van Dewars force. In such a "thermally conductive filler having a two-dimensional crystal structure", a clear crystal peak can be obtained experimentally from the periodic structure in wide-angle X-ray diffraction measurement (WAXD). Further, in the case of a plurality of laminated products, a crystal peak attributed to the periodic structure in the layered thickness direction can also be obtained.

For example, when the "thermally conductive filler (A) having a two-dimensional crystal structure" is graphene, the adhesive film according to this embodiment is measured by an X-ray diffraction method using a CuKα radiation source (wavelength 0.15418 nm). When this is done, it is preferable that peaks are detected at positions where 2θ is 26.6 ° and 42.4 °. The diffraction peaks at the positions where 2θ is 26.6 ° and 42.4 ° are the crystal peaks between the layers and in the plane of graphene, and when the peaks are detected at such positions, the graphene has a crystal structure. It can be said that it has.

When the "thermally conductive filler (A) having a two-dimensional crystal structure" is single-layer boron nitride, the adhesive film according to this embodiment is subjected to a CuKα radiation source (wavelength 0.15418 nm) by an X-ray diffraction method. When measured using, it is preferable that diffraction peaks are detected at positions where 2θ is 26.8 ° and 41.6 °. The peaks at the positions where 2θ is 26.8 ° and 41.6 ° are the crystal peaks between and in the plane of boron nitride, and when the peaks are detected at such positions, the boron nitride has a crystal structure. It can be said that it has. The above measurement can be performed using, for example, a wide-angle X-ray diffraction measurement diffraction device (manufactured by Rigaku Corporation, product name "SmartLab") or the like.

Examples of the thermally conductive filler (A) having a two-dimensional crystal structure include graphene, single-layer boron nitride and the like, and one type may be used alone or two or more types may be used in combination. .. Further, it may be used in combination with other heat conductive fillers such as alumina particles and aluminum nitride particles. Graphene in the present specification includes those produced by thinly peeling (cleaving) graphite. However, graphite itself does not fall under the above-mentioned definition of "thermally conductive filler having a two-dimensional crystal structure", and therefore does not fall under "thermally conductive filler having a two-dimensional crystal structure" in the present specification.

As the graphene, graphene obtained by a method of physically cleavage graphite is preferable, and such graphene has a good two-dimensional crystal structure. On the other hand, reduced graphene oxide (RGO) produced by cleaving once oxidized graphite into a single layer (graphene oxide) and reducing it to produce graphene oxide is not suitable for this embodiment because of its low crystallinity.

As described above, the thermally conductive filler (A) having a two-dimensional crystal structure such as graphene and single-layer boron nitride exhibits excellent thermal conductivity.

Graphene and single-layer boron nitride preferably have a thickness of 1/10 or less of the shortest length in a plan view shape.

The average particle size of the thermally conductive filler (A) having a two-dimensional crystal structure is preferably 0.5 μm or more, more preferably 1.0 μm or more, and particularly preferably 3.0 μm or more. Further, it is preferably 5.0 μm or more. As a result, the characteristics of the two-dimensional structure function, and the heat conductive fillers (A) are easily brought into contact with each other, and a heat conduction path is easily formed. Therefore, the obtained adhesive film has excellent heat conductivity. Become. The average particle size of the heat conductive filler (A) is preferably 30 μm or less, particularly preferably 20 μm or less, and further preferably 15 μm or less. As a result, the dispersed state is maintained in other materials such as the solvent and the binder polymer (D), it is suppressed that the heat conduction path is not formed due to segregation, and the adhesive film becomes more excellent in heat conductivity.

Further, the thickness of the thermally conductive filler (A) is preferably 500 nm or less, more preferably 300 nm or less, particularly preferably 200 nm or less, and further preferably 100 nm or less. As a result, the flexibility of the obtained adhesive film is maintained well. On the other hand, the lower limit of the thickness of the heat conductive filler (A) is not particularly limited, but is usually 0.7 nm or more, preferably 5.0 nm or more, and particularly preferably 10 nm or more from the viewpoint of heat conductivity. It is preferably 15 nm or more, and more preferably 15 nm or more.

The content of the heat conductive filler (A) in the adhesive film (adhesive resin composition R) is preferably 5% by mass or more, more preferably 10% by mass or more, and particularly 15% by mass or more. It is preferable that the amount is 20% by mass or more. Since the lower limit of the content of the heat conductive filler (A) is as described above, the heat conductive fillers (A) are likely to come into contact with each other and a heat conductive path is easily formed, so that the obtained adhesive film can be obtained. It becomes superior in thermal conductivity.

The content of the heat conductive filler (A) in the adhesive film (adhesive resin composition R) is preferably 60% by mass or less, more preferably 55% by mass or less, and particularly 50% by mass. % Or less, more preferably 40% by mass or less. When the upper limit of the content of the thermally conductive filler (A) is as described above, the obtained adhesive film is suppressed from becoming mechanically brittle, and the flexibility becomes more excellent. In the present embodiment, by using the heat conductive filler (A), the desired heat conductivity can be obtained even with a relatively small content as described above.

(2) Epoxy component (B)
The epoxy component (B) in the present embodiment may be a type that requires a curing agent (C) or a type that cures without a curing agent (C). In the case of the epoxy component (B) that requires the curing agent (C), at least one of the epoxy component (B) and the curing agent (C) has a π-conjugated mesogen skeleton. When the epoxy component (B) does not require a curing agent (C) and the adhesive film does not contain a curing agent (C), the epoxy component (B) has a π-conjugated mesogen skeleton. Both the epoxy component (B) and the curing agent (C) may have a π-conjugated mesogen skeleton.

As the epoxy component (B) having a π-conjugated mesogen skeleton, an epoxy resin having a naphthalene skeleton, an epoxy resin having a biphenyl skeleton, or an epoxy resin having an anthracene skeleton is preferable, and an epoxy resin having a naphthalene skeleton or a biphenyl skeleton is particularly used. Epoxy resin having is preferable. These may be used individually by 1 type, or may be used in combination of 2 or more type. The "epoxy resin" in the present specification also includes a non-polymerized or low molecular weight epoxy compound for convenience.

As the epoxy resin having a naphthalene skeleton, for example, one represented by the following formula is preferably mentioned.

(In the formula, n is an integer greater than or equal to 0.)

As the epoxy resin having a biphenyl skeleton, for example, one represented by the following formula is preferably mentioned.

(In the formula, n is an integer greater than or equal to 0.)

As the epoxy resin having an anthracene skeleton, for example, one represented by the following formula is preferably mentioned.

The epoxy equivalent of the epoxy component (B) having a π-conjugated mesogen skeleton is preferably 100 g / eq or more, particularly preferably 150 g / eq or more, and further preferably 180 g / eq or more. The epoxy equivalent is preferably 500 g / eq or less, particularly preferably 400 g / eq or less, and more preferably 300 g / eq or less. As a result, the dispersibility of the thermally conductive filler (A) becomes more excellent, and the adhesive property using the epoxy group is easily exhibited. The epoxy equivalent in the present specification is a value measured according to JIS K7236.

The softening point of the epoxy component (B) having a π-conjugated mesogen skeleton is preferably 40 ° C. or higher, particularly preferably 50 ° C. or higher, and further preferably 60 ° C. or higher. The softening point is preferably 200 ° C. or lower, particularly preferably 150 ° C. or lower, and further preferably 120 ° C. or lower. As a result, the dispersibility of the thermally conductive filler (A) becomes more excellent. The softening point in the present specification is a value measured according to the measurement method by the ring-and-ball method described in JIS K7234: 1986.

Examples of the epoxy component (B) having no π-conjugated mesogen skeleton include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenylnovolac, and cresolnovolac; alcohols such as butanediol, polyethylene glycol, and polypropylene glycol. Glycidyl ethers; glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid, tetrahydrophthalic acid; glycidyl-type or alkylglycidyl-type epoxy resins in which active hydrogen bonded to a nitrogen atom such as aniline isocyanurate is replaced with a glycidyl group; Vinyl Cyclohexane Diepoxide, 3,4-Epoxy Cyclohexylmethyl-3,4-Dicyclohexanecarboxylate, 2- (3,4-Epoxy) Cyclohexyl-5,5-Spiro (3,4-Epoxy) Cyclohexane-m-Dioxane So-called alicyclic epoxides in which an epoxy is introduced by, for example, oxidizing a carbon-carbon double bond in the molecule; a polyfunctional epoxy resin having three or more epoxy groups in the molecule, etc. be able to. As the polyfunctional epoxy resin, for example, a triphenylmethane type epoxy resin and the like are preferably mentioned. These epoxy resins can be used alone or in combination of two or more.

When the epoxy component (B) having a π-conjugated mesogen skeleton is used, it is preferable to use the epoxy component (B) having no π-conjugated mesogen skeleton together. This makes it possible to satisfactorily adjust the adhesiveness and adhesiveness of the adhesive film.

Among the above, the phenolic glycidyl ether is preferable as the epoxy component (B) having no π-conjugated mesogen skeleton, and the bisphenol F type epoxy resin is particularly preferable. When the epoxy component (B) having a π-conjugated mesogen skeleton is not used, the epoxy component (B) having no π-conjugated mesogen skeleton includes the phenolic glycidyl ether and the polyfunctional epoxy. It is preferable to use it in combination with a resin. The glycidyl ether of phenols is preferably a bisphenol F type epoxy resin, and the polyfunctional epoxy resin is preferably a triphenylmethane type epoxy resin. This makes it possible to satisfactorily adjust the adhesiveness and adhesiveness of the adhesive film.

The epoxy equivalent of the glycidyl ether of the above phenols is preferably 100 g / eq or more, particularly preferably 120 g / eq or more, and further preferably 150 g / eq or more. The epoxy equivalent is preferably 500 g / eq or less, particularly preferably 400 g / eq or less, and more preferably 300 g / eq or less. As a result, the adhesiveness and adhesiveness of the obtained adhesive film become more excellent.

The epoxy equivalent of the polyfunctional epoxy resin is preferably 80 g / eq or more, particularly preferably 100 g / eq or more, and further preferably 130 g / eq or more. The epoxy equivalent is preferably 400 g / eq or less, particularly preferably 300 g / eq or less, and more preferably 200 g / eq or less. As a result, the curability of the adhesive resin composition R becomes sufficient, and the adhesive property using the epoxy group is easily exhibited.

The softening point of the polyfunctional epoxy resin is preferably 40 ° C. or higher, particularly preferably 50 ° C. or higher, and further preferably 60 ° C. or higher. The softening point is preferably 200 ° C. or lower, particularly preferably 150 ° C. or lower, and further preferably 120 ° C. or lower. Thereby, it can be melted at the time of curing (during heat treatment), and an adhesive composition R having sufficient curability and adhesiveness can be obtained. Furthermore, it does not melt near room temperature, making it easy to handle.

The content (total content) of the epoxy component (B) in the adhesive film (adhesive resin composition R) is preferably 5% by mass or more, more preferably 10% by mass or more, and particularly 15 It is preferably 1% by mass or more, and more preferably 20% by mass or more. When the lower limit of the content of the epoxy component (B) is the above, the adhesive resin composition R can be sufficiently cured, and more excellent mechanical strength and adhesiveness can be exhibited. The content is preferably 45% by mass or less, more preferably 40% by mass or less, particularly preferably 35% by mass or less, and further preferably 30% by mass or less. .. When the upper limit of the content of the epoxy component (B) is as described above, the content of other components can be secured.

When the epoxy component (B) having a π-conjugated mesogen skeleton and the epoxy component (B) not having a π-conjugated mesogen skeleton are used in combination, the blending ratio (mass standard) thereof is 20:80 to 95: 5. It is preferably 40:60 to 90:10, more preferably 50:50 to 85:15, and further preferably 60:40 to 80:20. This makes it possible to achieve a good balance between the dispersibility of the heat conductive filler (A) and the adhesiveness / adhesiveness of the adhesive film.

When the phenolic glycidyl ether and the polyfunctional epoxy resin are used in combination, the blending ratio (mass standard) thereof is preferably 5:95 to 95: 5, preferably 10:90 to 90:10. It is more preferably 15:85 to 85:15, and further preferably 20:80 to 80:20. This makes it possible to achieve a good balance between the adhesiveness of the adhesive film before the curing reaction and the adhesiveness after the curing reaction.

(3) Hardener (C)
When the epoxy component (B) requires a curing agent (C), the adhesive film according to the present embodiment contains the curing agent (C) as an essential component. In this case, at least one of the epoxy component (B) and the curing agent (C) has a π-conjugated mesogen skeleton.

Phenols, amines, thiols and the like are preferably mentioned as the curing agent (C), and one type can be used alone or two or more types can be used in combination. Among the above, phenols (phenolic curing agents) are preferable from the viewpoint of reactivity with the epoxy component (B) and the like.

As the curing agent (C) having a π-conjugated mesogen skeleton, phenols having a π-conjugated mesogen skeleton are preferable, and as the phenols having a π-conjugated mesogen skeleton, biphenyl-type phenol is particularly preferable.

As the biphenyl type phenol resin, for example, those represented by the following formula are preferably mentioned.

(In the formula, n is an integer greater than or equal to 0.)

The hydroxyl group equivalent of the biphenyl-type phenol resin is preferably 80 g / eq or more, particularly preferably 85 g / eq or more, and further preferably 90 / eq or more. The hydroxyl group equivalent is preferably 300 g / eq or less, particularly preferably 280 g / eq or less, and more preferably 250 g / eq or less. This prevents the inclusion of substances that inhibit the curing reaction that remain as unreacted substances during synthesis, such as elemental phenol.
The curability of the epoxy component (B) becomes more excellent.

The softening point of the biphenyl-type phenol resin is preferably 60 ° C. or higher, particularly preferably 80 ° C. or higher, and further preferably 90 ° C. or higher. The softening point is preferably 200 ° C. or lower, particularly preferably 150 ° C. or lower, and further preferably 130 ° C. or lower. When the biphenyl-type phenol resin does not soften, its sublimation temperature is preferably 270 ° C. or higher. The sublimation temperature is preferably 330 ° C. or lower. Those having a high softening point or a high sublimation temperature effectively exhibit the interaction by π electrons, and the dispersibility of the thermally conductive filler (A) becomes more excellent.

As the curing agent (C) having no π-conjugated mesogen skeleton, phenols having no π-conjugated mesogen skeleton are preferable, and as the phenols having no π-conjugated mesogen skeleton, novolak type phenol resin is particularly preferable.

When a curing agent (C) having a π-conjugated mesogen skeleton is used, it is preferable to use the above-mentioned curing agent (C) having no π-conjugated mesogen skeleton together. This makes it possible to adjust the curability of the epoxy component (B).

The hydroxyl group equivalent of the novolak type phenol resin is preferably 70 g / eq or more, particularly preferably 80 g / eq or more, and further preferably 90 g / eq or more. The hydroxyl group equivalent is preferably 300 g / eq or less, particularly preferably 280 g / eq or less, and more preferably 250 g / eq or less. As a result, the curability of the epoxy resin becomes more excellent. The hydroxyl group equivalent in the present specification is a value measured according to JIS K0070.

The content (total content) of the curing agent (C) in the adhesive film (adhesive resin composition R) is preferably 2% by mass or more, more preferably 4% by mass or more, and particularly 5 It is preferably 1% by mass or more, and more preferably 8% by mass or more. The content is preferably 40% by mass or less, more preferably 35% by mass or less, particularly preferably 30% by mass or less, and further preferably 25% by mass or less. .. When the content of the curing agent (C) is in the above range, the curability of the adhesive resin composition R becomes better.

When the biphenyl-type phenol resin and the novolak-type phenol resin are used in combination, the blending ratio (mass standard) thereof is preferably 20:80 to 90:10, and more preferably 30:70 to 80:20. It is preferable, particularly preferably 35:65 to 75:25, and further preferably 40:60 to 70:30. Thereby, the curability of the adhesive resin composition R and the dispersibility of the heat conductive filler (A) can be well balanced.

(4) Binder polymer (D)
The binder polymer (D) is blended for the purpose of forming the adhesive resin composition R into a film, giving an appropriate tack to the obtained adhesive film, and the like. As such a binder polymer, for example, an acrylic polymer, a polyester resin, a phenoxy resin, a urethane resin, a silicone resin, a rubber polymer and the like are used, and an acrylic polymer is particularly preferably used.

Examples of the acrylic acid polymer include a (meth) acrylic acid ester polymer obtained by polymerizing a (meth) acrylic acid ester monomer and the like. In addition, in this specification, (meth) acrylic acid means both acrylic acid and methacrylic acid. The same applies to other similar terms. In addition, the concept of "polymer" shall be included in "polymer".

Examples of the monomer constituting the (meth) acrylate polymer include carbons of alkyl groups such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate. Examples thereof include (meth) acrylic acid alkyl esters having a number of 1 to 18, and functional group-containing monomers having a functional group in the molecule. Examples of the functional group-containing monomer include a monomer having a hydroxyl group in the molecule (hydroxyl group-containing monomer), a monomer having a carboxy group in the molecule (carboxy group-containing monomer), and a monomer having an amino group in the molecule (amino group-containing monomer). ) And the like. These may be used alone or in combination of two or more.

The (meth) acrylic acid ester polymer used as the binder polymer (D) in the present embodiment is a copolymerization of a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 18 carbon atoms and a functional group-containing monomer. It is preferable that it is an ester. The number of carbon atoms of the alkyl group in the (meth) acrylic acid alkyl ester is preferably 1 to 9, particularly preferably 1 to 6, and further preferably 1 to 3. As the (meth) acrylic acid alkyl ester, methyl (meth) acrylate is particularly preferable, and methyl acrylate is most preferable.

As the functional group-containing monomer, a hydroxyl group-containing monomer is preferable. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and (meth). ) Acrylic acid (meth) Acrylic acid hydroxyalkyl esters such as 3-hydroxybutyl acrylate and 4-hydroxybutyl (meth) acrylic acid can be mentioned. Among these, 2-hydroxyethyl (meth) acrylate is particularly preferable, and 2-hydroxyethyl acrylate is most preferable.

By using the above-mentioned monomer, the thermally conductive filler (A) can be easily dispersed in the adhesive resin composition R.

When a (meth) acrylic acid ester polymer obtained by copolymerizing the above (meth) acrylic acid alkyl ester and a functional group-containing monomer is used as the binder polymer (D), the (meth) acrylic acid ester polymer is contained. The structural unit derived from the functional group-containing monomer is preferably contained in the range of 5 to 90% by mass, particularly preferably in the range of 8 to 80% by mass, and further preferably in the range of 10 to 60% by mass. It is preferably contained.

The weight average molecular weight of the acrylic polymer ((meth) acrylic acid ester polymer) as the binder polymer (D) is preferably 50,000 or more, more preferably 100,000 or more, and particularly preferably 150,000 or more. It is preferably present, and more preferably 200,000 or more. The weight average molecular weight is preferably 1 million or less, more preferably 700,000 or less, particularly preferably 500,000 or less, and further preferably 400,000 or less. When the weight average molecular weight is in the above range, the film forming property and the adhesiveness become good, and the dispersibility of the heat conductive filler (A) becomes better. The weight average molecular weight in the present specification is a value in terms of standard polystyrene measured by a gel permeation chromatography (GPC) method.

The glass transition temperature (Tg) of the acrylic polymer ((meth) acrylic acid ester polymer) as the binder polymer (D) is preferably −20 ° C. or higher, more preferably −15 ° C. or higher. It is preferable, particularly preferably −10 ° C. or higher, and further preferably −5 ° C. or higher. The glass transition temperature (Tg) is preferably 60 ° C. or lower, more preferably 50 ° C. or lower, particularly preferably 40 ° C. or lower, and further preferably 35 ° C. or lower. .. When the glass transition temperature (Tg) is in the above range, the film forming property and the adhesiveness become good, and the dispersibility of the heat conductive filler (A) becomes better. The glass transition temperature (Tg) of the (meth) acrylic acid ester polymer in the present specification is a value calculated based on the FOX formula.

The content of the binder polymer (D) in the adhesive film (adhesive resin composition R) is preferably 1% by mass or more, more preferably 2% by mass or more, and particularly preferably 3% by mass or more. It is preferable, and more preferably 4% by mass or more. The content is preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 25% by mass or less. When the content of the binder polymer (D) is in the above range, the film formability and the adhesiveness are improved while maintaining good mechanical strength and adhesiveness of the cured product of the adhesive film. The dispersibility of the thermally conductive filler (A) becomes better.

(5) Curing accelerator (E)
The adhesive film according to this embodiment preferably further contains a curing accelerator (E) that promotes or adjusts the reaction between the epoxy component (B) and the curing agent (C) described above.

Examples of the curing accelerator (E) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris (dimethylaminomethyl) phenol; 2-methylimidazole, 2-phenylimidazole, and the like. Imidazoles such as 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole; tributylphosphine, diphenylphosphine, triphenylphosphine and the like. Organic phosphins; tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate can be mentioned. These can be used alone or in admixture of two or more.

When phenols are used as the curing agent (C), it is preferable to use an imidazole-based curing accelerator from the viewpoints of the reactivity of the curing reaction, storage stability, physical properties of the cured product, curing rate, and the like. In particular, 2-phenyl-4,5-hydroxymethylimidazole is preferably used.

The content of the curing accelerator (E) in the adhesive film (adhesive resin composition R) is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, and particularly 0. It is preferably .005% by mass or more, and more preferably 0.01% by mass or more. The content is preferably 1.0% by mass or less, more preferably 0.5% by mass or less, particularly preferably 0.1% by mass or less, and further preferably 0.05% by mass. It is preferably mass% or less. When the content of the curing accelerator (E) is in the above range, the storage stability of the adhesive film is improved and the adhesive resin composition R can be cured satisfactorily.

(6) Various Additives Various additives such as a tackifier, a flame retardant, an antioxidant, a light stabilizer, a softener, and a rust preventive are added to the adhesive resin composition in the present embodiment, if desired. can do.

2. 2. Preparation of Adhesive Resin Composition The adhesive resin composition R in the present embodiment contains a thermally conductive filler (A) composed of at least one of graphene and single-layer boron nitride having a two-dimensional structure, and an epoxy component (B). And, if desired, the binder polymer (D), the curing agent (C), the curing accelerator (E), the additive, and the solvent can be sufficiently mixed. If any of the above components is in the form of a solid, or if precipitation occurs when the components are mixed with other components in an undiluted state, the components may be used alone in advance as a solvent. It may be dissolved or diluted and then mixed with other ingredients.

The adhesive resin composition R in the present embodiment is prepared by previously mixing the thermally conductive filler (A) and the binder polymer (D) in a solvent, and then further adding the epoxy component (B) and, if desired, a curing agent. It is preferable to add (C), a curing accelerator (E), an additive and the like. By mixing the heat conductive filler (A) and the binder polymer (D) in advance before blending the epoxy component (B) and the like, the dispersibility of the heat conductive filler (A) becomes better and the coating is applied. Segregation of the thermally conductive filler (A) in the film is suppressed. As a result, the heat conductive filler (A) is uniformly dispersed in the obtained adhesive film, and an adhesive film having better heat conductivity can be obtained.

The heat conductive filler (A) and the binder polymer (D) are preferably mixed in a solvent at a speed of 500 to 5000 rpm of the disper for 10 minutes or more, preferably at the same speed of 1000 to 40,000 rpm. It is more preferable to stir for 20 minutes or more.

The solvent is not particularly limited, and is, for example, an aliphatic hydrocarbon such as hexane, heptane, or cyclohexane, an aromatic hydrocarbon such as toluene or xylene, a halogenated hydrocarbon such as methylene chloride or ethylene chloride, methanol, or the like. Alcohols such as ethanol, propanol, butanol, 1-methoxy-2-propanol, ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, cyclohexanone, esters such as ethyl acetate and butyl acetate, cellosolvent solvents such as ethyl cellosolve, N. , N-Dimethylformamide, trimethyl-2-pyrrolidone, butylcarbitol and the like are used, but methyl ethyl ketone is preferable.

The viscosity of the coating liquid of the adhesive resin composition R thus prepared is not particularly limited as long as it can be coated, and can be appropriately selected depending on the situation. It should be noted that the addition of the diluting solvent or the like is not a necessary condition, and the diluting solvent may not be added as long as the adhesive resin composition R has a viscosity and the like that can be coated.

3. 3. Production of Adhesive Film The adhesive film according to the present embodiment is obtained by forming the adhesive resin composition R obtained above into a film. In forming the adhesive resin composition R into a film, it is preferable to use a release sheet as a coating target. For example, the adhesive film according to the present embodiment can be easily produced by applying the coating liquid of the adhesive resin composition R to the release sheet and removing the diluting solvent by heating and drying.

Examples of the release sheet include a resin film, a non-woven fabric, and paper, but a resin film is generally used. Examples of the resin film include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, and polybutylene terephthalate film. Polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, etc. Is used. In addition, these crosslinked films are also used. Further, these laminated films may be used.

It is preferable that the peeling surface (the surface in contact with the adhesive resin composition R) of the peeling sheet is subjected to a peeling treatment. Examples of the release agent used in the release treatment include alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents. However, this peeling treatment is not always necessary.

The thickness of the release sheet is not particularly limited, but is usually about 20 to 150 μm.

As an example of manufacturing an adhesive film, the coating liquid of the adhesive resin composition R is applied to the peeling surface of the release sheet. As the coating method, for example, a bar coat method, a knife coat method, a roll coat method, a blade coat method, a die coat method, a gravure coat method and the like can be used.

Next, the coating film of the adhesive resin composition R is dried and a diluting solvent or the like is volatilized to obtain an adhesive film. The drying conditions are preferably 90 to 150 ° C. for 0.5 to 30 minutes, and particularly preferably 100 to 120 ° C. for 1 to 10 minutes. The heating temperature of the drying treatment needs to be lower than the thermosetting temperature of the adhesive resin composition R.

After the above drying treatment, it is preferable to laminate another peelable protective film on the exposed surface of the adhesive film to protect the adhesive film. At this time, the protective film is laminated so that the peelable surface of the removable protective film comes into contact with the exposed surface of the adhesive film. As a result, a laminate made of a release sheet / adhesive film / protective film can be obtained.

As the protective film, the same one as the above-mentioned release sheet mainly composed of the resin film can be used. The protective film may or may not be peeled off as long as it has peelability with respect to the adhesive film.

The adhesive film (laminated body) obtained as described above is preferably heat-pressed. By hot-pressing the adhesive film, the voids existing inside the adhesive film can be reduced, and the thermal conductivity becomes more excellent. Specifically, the heat press makes it easier for the heat conductive fillers (A) to come into contact with each other, makes it easier for the heat conduction path to be formed, and makes the heat conductivity more excellent. By performing such a hot press, the amount of the heat conductive filler (A) blended in the adhesive film can be further reduced, and the flexibility and adhesiveness of the adhesive film can be further improved.

The heating temperature of the hot press shall be lower than the curing reaction temperature of the epoxy component (B). Specifically, it is preferably 30 to 90 ° C, more preferably 40 to 80 ° C, particularly preferably 45 to 70 ° C, and further preferably 45 to 60 ° C.

The pressure of the hot press is preferably 0.5 to 15 MPa, more preferably 1 to 10 MPa, particularly preferably 1.5 to 5 MPa, and further preferably 2 to 4 MPa.

The heat pressing time is preferably 0.5 to 60 minutes, more preferably 1 to 40 minutes, particularly preferably 2 to 30 minutes, and further preferably 3 to 20 minutes. ..

4. Physical properties of the adhesive film (1) Thickness of the adhesive film The thickness of the adhesive film (including the adhesive film that has not been heat-pressed and the adhesive film that has been heat-pressed) according to this embodiment is the thickness (value measured according to JIS K7130). The lower limit is preferably 0.5 μm or more, more preferably 1 μm or more, particularly preferably 5 μm or more, and further preferably 10 μm or more. When the lower limit of the thickness of the adhesive film is the above, it is easy to exhibit good adhesive force and adhesive force.

The thickness of the adhesive film according to the present embodiment is preferably 1000 μm or less, more preferably 500 μm or less, particularly preferably 200 μm or less, and further preferably 100 μm or less as an upper limit value. Is preferable. When the upper limit of the thickness of the adhesive film is the above, the heat conduction becomes better. The adhesive film may be formed as a single layer, or may be formed by laminating a plurality of layers.

(2) Raman peak intensity ratio D / G
For the adhesive film according to the present embodiment (including the adhesive film not heat-pressed and the heat-pressed adhesive film), the absorption intensity peak value (IG) of the _G band near the wave number 1570 cm ^-1 in the absorption spectrum obtained by Raman measurement. The ratio (D / G) of the absorption intensity peak value ( _ID ) of the D band near the wave number of 1250 cm ^-1 (hereinafter, may be referred to as "Raman peak intensity ratio D / G") is 0.5 or less. It is preferably 0.4 or less, more preferably 0.3 or less, and further preferably 0.2 or less. When the Raman peak intensity ratio D / G is the above, it can be seen that the thermally conductive filler (A) contains a good crystal structure. As a result, the adhesive film exhibits excellent thermal conductivity due to the thermally conductive filler (A). The lower limit of the Raman peak intensity ratio D / G is not particularly limited, but is usually preferably 0.001 or more. The specific measurement method of Raman measurement in the present specification is as shown in a test example described later. The _G band peak near the wave number 1570 cm ^-1 here means a peak having a peak in the region of ± 100 cm ^-1 centered on the wave number 1570 cm ^-1 , and the absorption intensity peak value (IG) is measured. The relative value of the absorption intensity of the obtained peak top is shown. Similarly, the peak of the D band near the wave number 1250 cm ^-1 indicates a peak having a peak in the region of ± 100 cm ^-1 centered on the wave number 1250 cm ^-1 , and the absorption intensity peak value ( _ID ) is the peak obtained by measurement. The relative value of the absorption intensity of the top is shown.

(3) Adhesive strength The adhesive strength of the adhesive film (including the non-heat-pressed adhesive film and the heat-pressed adhesive film) according to the present embodiment to a silicon wafer (arithmetic average roughness (Ra): 0.02 μm or less). , 0.1 mN / 25 mm or more, more preferably 0.5 mN / 25 mm or more, particularly preferably 0.8 mN / 25 mm or more, and further preferably 1.0 mN / 25 mm or more. preferable. As a result, it adheres well to the adherend and can exhibit excellent temporary adhesiveness.

The upper limit of the adhesive strength is not particularly limited, but is usually preferably 5.0 mN / 25 mm or less, more preferably 3.0 mN / 25 mm or less, and particularly preferably 2.0 mN / 25 mm or less. preferable. As a result, the reworkability becomes excellent. The adhesive strength in the present specification basically refers to the adhesive strength measured by the 180-degree peeling method according to JIS Z0237: 2009, and the specific measuring method is as shown in the test example described later. ..

(4) Thermal Conductivity After Heat Curing The thermal conductivity of the adhesive film according to the present embodiment after heat curing (cured body) is preferably 4 W / mK or more, and particularly 5 W / mK or more. preferable. As a result, it can be said that the cured product of the adhesive film has excellent thermal conductivity. By having the above-mentioned structure, the adhesive film according to the present embodiment can achieve such a high thermal conductivity. The method for measuring the thermal conductivity in the present specification is as shown in a test example described later.

(5) Shear Adhesive Force After Thermosetting The shear adhesive force of the adhesive film according to this embodiment after thermosetting (cured body) is preferably 90 N / 5 × 5 mm ² or more, and particularly 100 N / 5 × 5 mm. It is preferably ² or more. As a result, it can be said that the cured product of the adhesive film has excellent mechanical strength. By having the above-mentioned structure, the adhesive film according to the present embodiment can achieve such a high shear adhesive force. The method for measuring the shear adhesive force in the present specification is as shown in a test example described later.

[Adhesive film with support sheet]
The adhesive film with a support sheet according to an embodiment of the present invention is laminated with the above-mentioned adhesive film (including a heat-pressed adhesive film and a heat-pressed adhesive film) on at least one surface side of the adhesive film. It is equipped with a support sheet. The support sheet may be peeled off from the adhesive film in the future.

By supporting the adhesive film on the support sheet, for example, the processability of the adherend can be improved. As an example, even if it is difficult to process the adherend with the adhesive film alone, the adhesive film with a support sheet is attached to the first adherend, processed in that state, and then the support sheet is peeled off. The adhesive film can be attached to the second adherend.

FIG. 1 shows an adhesive film with a support sheet as an example in this embodiment. The adhesive film 2 with a support sheet shown in FIG. 1 includes an adhesive film 1, a support sheet 11 laminated on one surface of the adhesive film 1 (upper surface in FIG. 1), and the other of the adhesive film 1. It is configured to include a release sheet 12 laminated on a surface (lower surface in FIG. 1). The release sheet 12 is laminated on the adhesive film 1 so that its peelable surface is in contact with the adhesive film 1. The release sheet 12 protects the adhesive film 1 until the adhesive film 1 is used, and may be omitted. Further, in the adhesive film with a support sheet in the present embodiment, a protective film may be laminated instead of the release sheet 12.

The support sheet 11 is not particularly limited as long as it can exhibit sufficient mechanical strength to support the adhesive film 1. Examples of the material constituting the support sheet 1 include a resin film, a non-woven fabric, paper, and the like, and a resin film is generally used.

Specific examples of the resin film include a polyethylene film such as a low density polyethylene (LDPE) film, a linear low density polyethylene (LLDPE) film, and a high density polyethylene (HDPE) film, a polypropylene film, an ethylene-propylene copolymer film, and a polybutene. Polyolefin films such as films, polybutadiene films, polymethylpentene films, ethylene-norbornene copolymer films, norbornene resin films; ethylene-vinyl acetate copolymer films, ethylene- (meth) acrylic acid copolymer films, ethylene- Ethylene-based copolymer film such as (meth) acrylic acid ester copolymer film; polyvinyl chloride-based film such as polyvinyl chloride film and vinyl chloride copolymer film; polyester-based film such as polyethylene terephthalate film and polybutylene terephthalate film. ; Polyurethane film; Polyimide film; Polystyrene film; Polycarbonate film; Fluororesin film and the like. Further, modified films such as these crosslinked films and ionomer films are also used. Further, it may be a laminated film in which a plurality of the same type or different types of the above film are laminated. The support sheet 11 may be a release sheet. Further, the support sheet 11 may be, for example, one in which a known pressure-sensitive adhesive layer is provided on the above-mentioned resin film, non-woven fabric, paper, or the like.

The thickness of the support sheet 11 is preferably 20 μm or more, particularly preferably 40 μm or more, and further preferably 60 μm or more. The thickness is preferably 150 μm or less, particularly preferably 120 μm or less, and further preferably 110 μm or less. When the thickness of the support sheet is within the above range, the support sheet 11 tends to have a desired mechanical strength, and the above-mentioned adherend workability and the like are good.

The adhesive film 2 with a support sheet may be a dicing / die bonding sheet used when manufacturing a semiconductor device. In this case, the adhesive film 2 with a support sheet can be used in the steps of dicing and dicing the semiconductor element, and the cured product of the adhesive film is for releasing the heat generated when the semiconductor device is driven to the outside world. Functions as a heat conductive material. In this case, the support sheet 11 is preferably provided with, for example, a known pressure-sensitive adhesive layer on the surface of the resin film described above on the side of the adhesive film 1.

As an example of manufacturing the adhesive film 2 with a support sheet, the release sheet may be peeled off from the above-mentioned laminate made of the release sheet / adhesive film / protective film and the support sheet may be laminated, or the above-mentioned release sheet / adhesion may be performed. The protective film may be peeled off from the laminate made of the film / protective film and the support sheet may be laminated, or the support sheet may be used instead of the protective film in the above-mentioned method for producing an adhesive film.

〔Structure〕
In the structure according to the embodiment of the present invention, at least a part of the first member and at least a part of the second member are bonded to each other via the cured body of the adhesive film described above. ..

FIG. 2 shows a structure as an example in this embodiment. The structure 3 shown in FIG. 2 includes a first member 31, a second member 32, and a cured body 1A provided between the first member 31 and the second member 32.

The cured product 1A is a product obtained by completely curing the above-mentioned adhesive film (adhesive film 1; including a heat-pressed adhesive film and a heat-pressed adhesive film) by heat treatment. The first member 31 and the second member 32 are fixed to each other by the adhesiveness of the cured body 1A (adhesive film). The shapes of the first member 31 and the second member 32 in the present embodiment are not particularly limited, but may be a flexible sheet shape, a plate shape, a block shape, or the like. There may be.

The first member 31 (or the second member 32) in the present embodiment is not particularly limited, but for example, a member that generates heat as a result of exerting a predetermined function but is required to suppress a temperature rise, or the member generates heat. A member (heat generating member) that is required to control the flow of heat in a specific direction is preferable. Further, the second member 32 (or the first member 31) is not particularly limited, but a member that dissipates heat received or a member that transfers the received heat to another member (heat transfer member) is preferable. .. Since the cured body 1A in the present embodiment has excellent thermal conductivity, for example, heat for conducting heat of the generated first member 31 to the second member 32 and releasing the heat to the outside world. Functions as a conductive material.

Examples of the heat generating member include thermoelectric conversion devices, photoelectric conversion devices, semiconductor devices such as large-scale integrated circuits, electronic devices such as LED light emitting elements, optical pickups, and power transistors, and various electronic devices such as mobile terminals and wearable terminals. Examples include batteries, batteries, motors, engines, etc. Further, the heat transfer member is preferably made of a highly conductive material, for example, a metal such as aluminum, stainless steel or copper, graphite, carbon nanofibers or the like. The form of the heat transfer member may be any of a substrate, a housing, a heat sink, a heat spreader, and the like, and is not particularly limited.

The first member 31 is preferably a semiconductor element as an example, and the second member 32 is preferably a substrate as an example. In this case, when the semiconductor element, which is the first member 31, generates heat, the heat of the semiconductor element is dissipated through the cured body 1A and the substrate, which is the second member 32. The semiconductor device composed of the above members can be manufactured by using the adhesive film 2 with a support sheet described above as a dicing die bonding sheet.

Further, the second member 32 may be a semiconductor element instead of the substrate as an example. In this case, when the semiconductor element which is the first member 31 or the second member 32 generates heat, the heat of the generated semiconductor element is conducted to the other semiconductor element via the cured body 1A, and each semiconductor element. The temperature becomes uniform. As a result, damage or the like caused by thermal stress or the like of the structure 3 (semiconductor device) is suppressed.

In order to manufacture the structure 3 according to the present embodiment, one side of the adhesive film described above is attached to the first member 31 (or the second member 32), and then the other side of the adhesive film is attached. It is attached to the second member 32 (or the first member 31). When the adhesive film 2 with a support sheet described above is used, the release sheet 12 is peeled off, one surface of the exposed adhesive film 1 is attached to the first member 31 (or the second member 32), and then the exposed adhesive film 1 is attached. , The support sheet 11 is peeled off, and the other surface of the exposed adhesive film 1 is attached to the second member 32 (or the first member 31).

The adhesive film used to manufacture the structure 3 according to the present embodiment may be either a heat-pressed adhesive film or a heat-pressed adhesive film, but a heat-pressed adhesive film is used. Is preferable. Further, after the adhesive film is attached to the first member 31 (or the second member 32) using an adhesive film that has not been heat-pressed, or through the adhesive film, the first member 31 and the first member 31 The adhesive film may be hot-pressed after being bonded to the member 32 of 2. However, if an adhesive film that has been heat-pressed in advance is used, it is possible to prevent the first member 31 and / or the second member 32 from being damaged by the heat press.

Here, any method is used when the first member 31 and the second member 32 are attached to each other via the adhesive film, or when the adhesive film is attached to the first member 31 or the second member 32. When the temperature is higher than the temperature showing the peak of loss tangent (tan δ) obtained by measuring the viscoelasticity of the adhesive film before heat treatment (hereinafter sometimes referred to as “tan δ peak temperature”) (hereinafter referred to as “pasting treatment temperature”). There is.), It is preferable to perform the above-mentioned bonding or pasting. By affixing or affixing at such a temperature, the adhesive film becomes flexible, and it is possible to more effectively suppress the entrainment of air between the adhesive film and the adherend. The thermal conductivity between can be made better.

The first member 31 is a flexible sheet-like member, and when the laminated body of the sheet-like member and the adhesive film is attached to the second member 32, or when the adhesive film 2 with a support sheet is attached to the first member. When it is attached to the member 31 or the second member 32, the above-mentioned air entrainment suppressing effect becomes more excellent. Since the laminated body of the sheet-like member and the adhesive film and the adhesive film 2 with a support sheet are flexible and easy to bend, they can be gradually brought into close contact with the adherend from one direction to the other, and air is pushed out. This is because it can be pasted while.

The above-mentioned pasting treatment temperature is preferably 0 to 50 ° C. higher than the tan δ peak temperature, particularly preferably 3 to 30 ° C., and further preferably 5 to 20 ° C. Further, the upper limit of the above-mentioned application processing temperature needs to be lower than the curing temperature of the adhesive film, specifically, it is preferably 120 ° C. or lower, particularly preferably 100 ° C. or lower, and further. It is preferably 90 ° C. or lower.

As described above, one side of the adhesive film is attached to the first member 31 (or the second member 32), and the other side of the adhesive film is attached to the second member 32 (or the first member 31). After being attached to the above, heat treatment is performed to completely cure the adhesive film to obtain a cured product 1A, and the structure 3 according to the present embodiment is obtained.

In the above heat treatment, the adhesive film is subjected to thermal weight measurement under the condition that the temperature of the adhesive film before any heat treatment is raised from 40 ° C. to 400 ° C. at a temperature rise rate of 10 ° C./min in an air atmosphere. A preheating step of holding the adhesive film at a temperature of 0.5% weight reduction or less (hereinafter sometimes referred to as "preheating temperature") for 30 minutes or more, and a complete curing step of completely curing the adhesive film after the preheating step. It is preferable to include. When the adhesive film is completely cured by a rapid heat treatment, the small molecule components in the adhesive film volatilize and foam due to heating, and voids are likely to be formed inside the adhesive film. On the other hand, when the heat treatment includes the above steps, the small molecule component is taken into the matrix of the epoxy component (B), the binder polymer (D) and the like before being volatilized and trapped, so that foaming is suppressed. The voids in the adhesive film will be reduced. As a result, the thermal conductivity of the obtained cured product becomes more excellent. By performing the above-mentioned heat pressing on the adhesive film according to the present embodiment and performing the above-mentioned preheating step, the voids of the obtained cured product can be more effectively reduced.

The preheating temperature is preferably 1 to 50 ° C. lower than the temperature at which the adhesive film loses weight by 0.5%, particularly preferably 10 to 40 ° C., and further preferably 15 to 30 ° C. The lower limit of the preheating temperature is preferably 80 ° C. or higher, particularly 90 ° C. or higher, and more preferably 100 ° C. or higher.

Further, the above preheating step is preferably performed for 30 minutes or more, particularly preferably 30 to 120 minutes, and further preferably 30 to 60 minutes.

It is preferable that the heat treatment is performed by performing the preheating step and then performing a complete curing step at a heating temperature at which the adhesive film is completely cured. The heating temperature in the complete curing step needs to be higher than the above-mentioned preheating temperature, preferably 5 to 100 ° C. higher than the preheating temperature, particularly preferably 10 to 70 ° C., and further. It is preferably 20 to 50 ° C. higher. Specifically, the heating temperature in the complete curing step is preferably 85 to 200 ° C, particularly preferably 100 to 190 ° C, and further preferably 120 to 180 ° C.

Further, the above-mentioned complete curing step is preferably performed for 30 to 180 minutes, particularly preferably 45 to 150 minutes, and further preferably 60 to 120 minutes.

The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

For example, in FIG. 1, the release sheet 12 laminated on the adhesive film 1 may be omitted. Further, the shapes of the first member and the first member in the structure are not limited to those shown in FIG. 2, and may be various shapes.

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope of the present invention is not limited to these Examples and the like.

[Examples 1 to 4, Comparative Examples 1 to 5]
The following thermally conductive fillers (A) (components (a-1) to (a-3)) and binder polymers (D) (components (d)) are mixed so that the solid content concentration becomes 15% by mass. Diluted with methyl ethyl ketone was stirred with a disper at a rotation speed of 3000 rpm for 30 minutes or more to dissolve and disperse. On the other hand, the following epoxy components (B) ((b-1) to (b-5) components), curing agent (C) ((c-1) to (c-3) components) and curing accelerator (E) ) (Component (e)) is dispersed in methyl ethyl ketone so that each has a solid content concentration of 10 to 70% by mass, and is blended in the above dispersion liquid so that the total solid content concentration becomes 25% by mass. Methyl ethyl ketone was added. This mixed solution was stirred with a rotating / revolving mixer (manufactured by Shinky Co., Ltd., product name "AR-100") for 10 minutes to obtain a coating liquid for an adhesive resin composition. The types and contents (in terms of solid content) of each component in the adhesive resin composition are as shown in Table 1. The coating liquid of this adhesive resin composition was also used in the preparation of a sample for measuring the adhesive strength in Test Example 2 (measurement of adhesive strength) described later.

-Thermal conductive filler (A)
(A-1) Thermally conductive filler (having a two-dimensional crystal structure): Graphene (manufactured by ADEKA, product name "CNS-1A1", average particle size 12 μm, thickness 50 nm or less, Raman peak intensity ratio D / G = 0) 1. When measured by X-ray diffraction method using a CuKα radiation source (wavelength 0.15418 nm), peaks are detected at positions where 2θ is 26.6 ° and 42.4 °).
(A-2) Thermally conductive filler: Reduced graphene oxide (manufactured by ANGSTRON MATERIALS, product name "N002-PDR", average particle size 8 to 10 μm, thickness 1.0 to 1.2 nm, Raman peak intensity ratio D / When measured using a CuKα radiation source (wavelength 0.15418 nm) by G = 1.3, X-ray diffraction method, no peak was detected at the position where 2θ was 26.6 °).
(A-3) Thermally conductive filler: Graphite (manufactured by Nippon Graphite Co., Ltd., product name "CSP-E", average particle size 8 μm, thickness 8 μm, Raman peak intensity ratio D / G = 0.1, by X-ray diffraction method When measured using a CuKα radiation source (wavelength 0.15418 nm), peaks were detected at positions where 2θ was 26.6 ° and 42.4 °).

-Epoxy component (B)
(B-1) Epoxy component: Epoxy resin having a naphthalene skeleton represented by the following formula (1) (solid, manufactured by Nippon Kayaku Co., Ltd., product name "NC-7000L", epoxy equivalent 223 to 238 g / eq, ICI viscosity) (150 ° C) 0.50 to 1.00 Pa · s, softening point 83 to 93 ° C)

(In the formula, n is an integer greater than or equal to 0.)

(B-2) Epoxy component: Epoxy resin having a biphenyl skeleton represented by the following formula (2) (solid, manufactured by Nippon Kayaku Co., Ltd., product name "NC-3000H", epoxy equivalent 280 to 300 g / eq, ICI viscosity) (150 ° C) 0.25 to 0.35 Pa · s, softening point 65 to 75 ° C)

(In the formula, n is an integer greater than or equal to 0.)

(B-3) Epoxy component: Bisphenol F type epoxy resin (liquid, manufactured by Mitsubishi Chemical Corporation, product name "YL983U", epoxy equivalent 165 to 175 g / eq, viscosity (25 ° C.) 3.0 to 6.0 Pa · s)
(B-4) Epoxy component: Polyfunctional epoxy resin (solid, manufactured by Nippon Kayaku Co., Ltd., product name "EPPN-502H", epoxy equivalent 158 to 178 g / eq, ICI viscosity (150 ° C.) 0.01 to 0. 35 Pa · s, softening point 60-72 ° C)
(B-5) Epoxy component: Cresol novolac type epoxy resin (solid, manufactured by Nippon Kayaku Co., Ltd., product name "EOCN-104S", epoxy equivalent 213 to 223 g / eq, ICI viscosity (150 ° C.) 2.55 to 3. 45 Pa · s, softening point 90-94 ° C)

・ Hardener (C)
(C-1) Curing agent: Biphenyl-type phenol compound represented by the following formula (3) (manufactured by Honshu Chemical Industry Co., Ltd., product name "BP", hydroxyl group equivalent 93.1 g / eq, sublimation temperature 283 ° C.)

(C-2) Curing agent: Novolac type phenol resin (manufactured by Asahi Organic Materials Industry Co., Ltd., product name "PAPS-PN4", hydroxyl group equivalent 104 g / eq, ICI viscosity (150 ° C.) 3.0 Pa · s, softening point 111 ° C. )
(C-3) Curing agent: Polyfunctional phenol resin (manufactured by Meiwa Kasei Co., Ltd., product name "MHE-7500", hydroxyl group equivalent 95 to 99 g / eq, ICI viscosity (150 ° C.) 0.73 to 1.03 Pa · s , Softening point 107-113 ° C)

-Binder polymer (D)
(D) Binder polymer: obtained by copolymerizing an acrylic acid ester polymer (manufactured by Mitsubishi Chemical Corporation, product name "Corponil N-4617", 85 parts by mass of methyl acrylate and 15 parts by mass of 2-hydroxyethyl acrylate). Copolymer, weight average molecular weight: 300,000, glass transition temperature: 6 ° C) dissolved in a 1: 1 mixed solvent of ethyl acetate and toluene (solid content concentration 36% by mass)

・ Curing accelerator (E)
(E) Curing accelerator: 2-phenyl-4,5-hydroxymethylimidazole (manufactured by Shikoku Chemicals Corporation, product name "Curesol 2PHZ")

A release sheet (manufactured by Lintec Corporation, product name "SP-PET3811 (S)") in which one side of a polyethylene terephthalate film is peeled off with a silicone-based release agent from the coating liquid of the adhesive resin composition obtained in the above step. After applying with an applicator to the peeled surface, it was heat-treated at 100 ° C. for 2 minutes and dried to form an adhesive film (thickness: 50 μm). After that, an adhesive film with a release sheet was attached to the release-treated surface of the protective film (manufactured by Lintec Corporation, product name "SP-PET3811 (S)") in which one side of the polyethylene terephthalate film was peeled off with a silicone-based release agent. A laminate composed of a release sheet, an adhesive film (thickness: 50 μm), and a protective film was obtained.

The adhesive film was hot-pressed by applying the pressure of 3.0 MPa to the laminate obtained above for 10 minutes at 50 ° C. using a hydraulic heating press device. By this hot press, the voids existing inside the adhesive film were almost crushed. In this way, a heat-pressed laminate composed of a release sheet, a heat-pressed adhesive film (thickness: 22 μm), and a protective film was obtained.

[Test Example 1] <Raman measurement>
The laminates after hot pressing obtained in Examples and Comparative Examples were subjected to Raman measurement using a microlaser Raman spectroscope (manufactured by Thermo Fisher, product name "DXR2"). Then, the absorption intensity peak value (IG) of the _G band near the wave number of 1570 cm ^-1 and the absorption intensity peak value of the D band near the wave number of 1250 cm ^-1 obtained from the graph of the absorption spectrum measured at the laser wavelength of 532 nm (IG). From I _D ), the ratio of the absorption intensity peak value ( _ID ) to the absorption intensity peak value (IG) (Raman peak intensity ratio D / _G ) was calculated.

The results of Raman measurements on the adhesive film of Example 1 and the adhesive film of Comparative Example 2 are shown in FIGS. 3 and 4, respectively. In the graph of FIG. 3, the absorption intensity peak value (ID) of the _D band near the wave number 1250 cm ^-1 is small, while the absorption intensity peak value (IG) of the _G band near the wave number 1570 cm ^-1 is large. I understand. The ratio of the absorption intensity peak value ( _ID ) to the absorption intensity peak value (IG) (Raman peak intensity ratio D / _G ) is calculated to be 0.1.

In the graph of FIG. 4, the absorption intensity peak value (ID) of the _D band near the wave number 1250 cm ^-1 and the absorption intensity peak value (IG) of the _G band near the wave number 1570 cm ^-1 are almost the same magnitude. .. The ratio of the absorption intensity peak value ( _ID ) to the absorption intensity peak value (IG) (Raman peak intensity ratio D / _G ) is calculated to be 1.3. The results are shown in Table 2, including other examples and comparative examples.

[Test Example 2] <Adhesive strength measurement>
The coating liquid of the adhesive resin composition obtained in Examples and Comparative Examples was applied to one side of a polyethylene terephthalate film having a thickness of 12 μm, heat-treated at 100 ° C. for 2 minutes and dried to form a polyethylene terephthalate film. A laminated body in which an adhesive film (thickness: 50 μm) was firmly bonded was produced.

Next, for the purpose of protecting the surface of the adhesive film, a release-treated surface of a release film (manufactured by Lintec Corporation, product name "SP-PET38131", thickness 38 μm) was attached to the surface of the laminate on the adhesive film side. The obtained laminate was heat-pressed by applying a pressure of 3.0 MPa at 50 ° C. for 10 minutes using a hydraulic heating press device. Then, the laminated body was cut together with the release film to prepare a sample for measuring adhesive strength having a width of 25 mm.

As an adherend, a silicon wafer (manufactured by Science and Technology Research Institute, diameter: 150 mm, thickness: 500 μm) having an arithmetic mean roughness (Ra) of the surface of 0.02 μm or less was prepared by chemical mechanical polishing treatment. The release film of the adhesive strength measurement sample was peeled off, and the exposed surface of the adhesive film was attached to the treated surface of the silicon wafer in an atmosphere of 80 ° C. to obtain a laminate composed of the silicon wafer and the adhesive strength measurement sample.

After leaving the obtained laminate in an atmosphere of 23 ° C. and 50% relative humidity for 20 minutes, JIS Z0237: 2000 was used using a universal tensile tester (manufactured by Instron, product name "5581 type tester"). In accordance with the above, a 180 ° peeling test was conducted at a peeling speed of 300 mm / min. The load at the time of this 180 ° peeling was measured, and the measured value was taken as the adhesive force (N / 25 mm). The results are shown in Table 2.

[Test Example 3] <Evaluation of brittleness>
The laminated body after hot pressing obtained in Examples and Comparative Examples was cut into a width of 1 cm, and two release films were peeled off. The obtained adhesive film after hot pressing was stretched at a tensile speed of 50 mm / min using a universal tensile tester (manufactured by Instron, product name "5581 type tester"). The phenomenon at this time was evaluated as the brittleness of the adhesive film according to the following criteria. The results are shown in Table 2.
◯: Elongated 1.1 times or more.
Δ: Elongation occurred, but did not elongate more than 1.1 times.
X: No elongation was performed, and residue was generated during cutting.

[Test Example 4] <Measurement of thermal conductivity>
The laminates after hot pressing obtained in Examples and Comparative Examples were heat-treated at 125 ° C. for 1 hour (preheating step), then heat-treated at 175 ° C. for 2 hours (complete curing step), and after hot pressing. The adhesive film was completely cured to obtain a cured product.

The cured body of the obtained adhesive film was cut to obtain a square sample with each side of 5 mm. The thermal diffusivity of the cured product of the adhesive film was measured using a thermal conductivity measuring device (manufactured by aiphase, product name "Eye Phase Mobile 1u"). Then, the thermal diffusivity was multiplied by the specific gravity and the specific heat to calculate the thermal conductivity (W / mK) of the cured product of the adhesive film. The results are shown in Table 2.

[Test Example 5] <Measurement of shear adhesive force>
(1) Fabrication of adherend chip One side of a silicon wafer (150 mm diameter, thickness 350 μm) was # 2000 polished by a wafer backside grind device (manufactured by DISCO, product name “DFG8540”). A dicing tape (manufactured by Lintec Corporation, product name "Adwill D-175") is attached to the surface of the silicon wafer opposite to the polished surface by a tape mounter (manufactured by Lintec Corporation, product name "Adwill RAD2500"), and the silicon wafer is attached. Was fixed to the ring frame for wafer dicing so that the polished surface was on the upper surface. Next, using a dicing device (manufactured by DISCO, product name "DFD6362"), the base material of the dicing tape is diced so as to cut 20 μm, and an adherend chip (adhesion 1) having a size of 5 mm × 5 mm is produced. bottom.

In addition, one side of a silicon wafer (200 mm diameter, thickness 350 μm) is dry-polished by a wafer backside grind device (manufactured by DISCO, product name “DGP8760”) to reduce the surface roughness (Ra) to 0.12 μm or less. bottom. A dicing tape (manufactured by Lintec Corporation, product name "Adwill D-175") is attached to the surface of the silicon wafer opposite to the dry-polished surface in the same manner as above, and the dry-polished surface of the silicon wafer is on the upper surface. It was fixed to the ring frame for wafer dicing so as to be. Next, dicing was performed in the same manner as above to prepare an adherend chip (adhesion body 2) having a size of 12 mm × 12 mm.

(2) Preparation of Measurement Test Piece The first release sheet of the laminated body after hot pressing obtained in Examples and Comparative Examples was peeled off, and the polished surface of the adherend 1 obtained in the above step (1) was applied. The exposed surface of the adhesive film after hot pressing was attached at 80 ° C. Then, the adhesive film protruding from the adherend 1 was trimmed with a cutter so that the shape of the adhesive film was the same as the shape of the adherend 1.

Next, the second release sheet is peeled off from the laminated body, and the exposed surface of the adhesive film after hot pressing is pressure-bonded to the dry-polished surface of the adherend 2 heated to 120 ° C. on a hot plate to press the adherend. A structure composed of 1, an adhesive film after hot pressing, and an adherend 2 was obtained. The obtained structure was heat-treated at 125 ° C. for 1 hour (preheating step) and then heat-treated at 175 ° C. for 2 hours (complete curing step), and the adhesive film after hot pressing was completely cured to obtain a cured product. .. In this way, a test piece composed of the adherend 1, the cured adhesive film, and the adherend 2 was obtained.

(3) Measurement of shear adhesive force The test piece obtained in the above step (2) is placed on a measurement stage of a bond tester (manufactured by Dage, product name "Bond Tester Series 4000") set at 250 ° C. for 30 seconds. Place and apply stress in the direction perpendicular to the adhesive surface (shearing direction) at a speed of 200 μm / s from a position 10 μm above the adherend 1 located on the upper side of the test piece, and apply stress to the cured body and the adherend of the adhesive film. The force (shear adhesive force, N / 5 × 5 mm ² ) when the adhesive state of the body 2 with the dry-polished surface was broken was measured. The average value of the shear adhesive force of the six test pieces was calculated as a measured value of one level. The results are shown in Table 2.

As can be seen from Table 2, the cured product of the adhesive film produced in the examples had excellent thermal conductivity and also excellent shear adhesive strength. In addition, the adhesive film (before curing) produced in the examples had good adhesive strength and was not mechanically brittle.

The adhesive film according to the present invention can be suitably used for cooling the electronic device by interposing it between the heat-generating electronic device and the heat-dissipating substrate or heat sink, for example. Further, the structure according to the present invention is useful as, for example, a structure including an electronic device that generates heat and a heat-dissipating substrate or heat sink.

1 ... Adhesive film 11 ... Support sheet 12 ... Release sheet 2 ... Adhesive film with support sheet 3 ... Structure 1A ... Cured body of adhesive film 31 ... First member 32 ... Second member

Claims

A thermally conductive filler (A) having a two-dimensional crystal structure and
Epoxy component (B) and
Hardener (C) and
An adhesive film containing a binder polymer (D).
An adhesive film characterized in that at least one of the epoxy component (B) and the curing agent (C) has a π-conjugated mesogen skeleton.
A thermally conductive filler (A) having a two-dimensional crystal structure and
Epoxy component (B) having a π-conjugated mesogen skeleton and
An adhesive film containing a binder polymer (D).
The adhesive film according to claim 1 or 2, wherein the content of the heat conductive filler (A) having the two-dimensional crystal structure is 5% by mass or more and 60% by mass or less.
The adhesive film according to any one of claims 1 to 3, wherein the heat conductive filler (A) having the two-dimensional crystal structure is graphene.
The ratio (D / G) of the absorption intensity peak value ( ID ) of the D band near 1250 cm -1 to the absorption intensity peak value (IG) of the G band near 1570 cm -1 in the absorption spectrum obtained by Raman measurement. However, the adhesive film according to claim 4, wherein the pressure is 0.5 or less.
The adhesive film according to any one of claims 1 to 5, wherein the epoxy component (B) has a naphthalene skeleton or a biphenyl skeleton as the π-conjugated mesogen skeleton.
The adhesive film according to claim 1, wherein the curing agent (C) is a phenol-based curing agent having a biphenyl skeleton as the π-conjugated mesogen skeleton.
The adhesive film according to any one of claims 1 to 7, which is hot-pressed.
After mixing the thermally conductive filler (A) having a two-dimensional crystal structure and the binder polymer (D) in a solvent, an epoxy component (B) in which at least one component has a π-conjugated mesogen skeleton. And the curing agent (C) are mixed to obtain an adhesive resin composition.
A method for producing an adhesive film, which comprises forming the obtained adhesive resin composition into a film.
Adhesion is performed by mixing the thermally conductive filler (A) having a two-dimensional crystal structure and the binder polymer (D) in a solvent, and then further mixing the epoxy component (B) having a π-conjugated mesogen skeleton. Obtaining a sex resin composition,
A method for producing an adhesive film, which comprises forming the obtained adhesive resin composition into a film.
The method for producing an adhesive film according to claim 9, wherein the adhesive resin composition is formed into a film and then heat-pressed.
The adhesive film according to any one of claims 1 to 8 and
An adhesive film with a support sheet provided with a support sheet laminated on at least one surface side of the adhesive film.
A structure in which at least a part of the first member and at least a part of the second member are joined via a cured body of the adhesive film according to any one of claims 1 to 8.
The structure according to claim 13, wherein the first member is a semiconductor element, and the second member is a semiconductor element or a substrate.
After attaching at least a part of the first member to at least a part of the second member via the adhesive film according to any one of claims 1 to 8, the adhesive film is heat-treated. A method for producing a structure in which at least a part of a first member and at least a part of a second member are joined via a cured body by forming a cured body.