JP7408286B2 - Release film and electronic device manufacturing method - Google Patents

Description

The present invention relates to a release film and a method for manufacturing an electronic device.

Film adhesives such as anisotropic conductive film (ACF) and non-conductive adhesive film (NCF) are used in the manufacturing process of electronic devices. There is a process in which various parts and members (hereinafter also referred to as electronic components) are electrically connected to each other by heat compression bonding.
Adhesives such as ACF and NCF contain thermosetting resins such as epoxy resins. When an adhesive is placed between two electronic components and the electronic components are bonded together by heat and pressure, the thermosetting resin contained in the adhesive is cured by heat, making it possible to join the electronic components together.
In the process of heat-pressing electronic components, a release film is placed between the heat-pressing head for heat-pressing and the electronic components to prevent adhesion between the heat-pressing head and the electronic components. is placed.

Examples of techniques related to such a release film include those described in Patent Document 1 (Japanese Patent Laid-Open No. 2006-231916) and Patent Document 2 (Japanese Patent Laid-Open No. 2007-8153).

Patent Document 1 discloses a press-release sheet used for joining electronic components by heat-pressing, which includes a silicone rubber layer and a first porous polytetrafluoroethylene layer, and includes a silicone rubber layer and a first porous polytetrafluoroethylene layer. A press release sheet is described in which the tetrafluoroethylene layer has pores, and the silicone rubber layer and the first porous polytetrafluoroethylene layer are integrated with each other.

Patent Document 2 discloses a pressure-bonding release sheet used for joining electronic components by heat-compression bonding, which includes an ultra-high molecular weight polyethylene layer and a silicone rubber layer, the ultra-high molecular weight polyethylene layer and the silicone rubber layer. A press-release sheet is described in which the ultra-high molecular weight polyethylene layer has a thickness of 30 μm or more.

Japanese Patent Application Publication No. 2006-231916 Japanese Patent Application Publication No. 2007-8153

Incidentally, in recent years, through-silicon via (TSV) technology, which enables higher density and smaller size of semiconductor devices, has attracted attention and is being developed. By using this technology, semiconductor chips can be stacked to form a three-dimensional structure, so it is possible to achieve significantly higher density and smaller size than conventional devices.
In this technology, the chips are stacked and then heat-pressed, so the heater is heated to a higher temperature than before so that the heat can be transmitted to the underlying chips. Accordingly, release films are also required to have further heat resistance.

According to studies by the present inventors, when electronic components are heat-pressed together using a heater via a release film, the semiconductors and metal materials that make up the electronic components and the release film become more difficult to separate as the temperature increases. was discovered.
Conventionally, a fluororesin film or a film in which a fluororesin is coated on a support layer has been used as a release film for this purpose. When placing an adhesive such as ACF or NCF between two electronic components and heat-pressing the electronic components together at high temperatures, the higher the temperature, the more the resin components that make up the adhesive and the release film will melt. It has become clear that some of the adhesive may adhere to the release film due to the fusion.
If some of the adhesive adheres to the release film, the adhesive adhered to the release film will fall into the production line, causing contamination or stoppage of the production line, and reducing product yield. There are concerns.
Although the detailed reason why a part of the adhesive adheres to the release film is not clear, the following reasons can be considered. When electronic components are bonded together under heat and pressure, for example, the release film is heated to 300° C. or higher. At this time, it is thought that the resin component constituting the adhesive is in a molten state, and the release layer of the release film is further softened and is in a state close to a molten state. Then, a portion of the molten adhesive and a portion of the release layer that is close to the molten state become compatible. As a result, when the release film is peeled off from the electronic component, some of the adhesive remains on the surface of the release layer of the release film, and as a result, some of the adhesive adheres to the release film. It is thought that this will happen.
On the other hand, by using a heat-resistant resin such as polyimide for the support layer, the heat resistance of the release film can be improved. However, according to studies by the present inventors, due to the increased thickness of the support layer, such a heat-resistant release film has a tendency to cause damage between two electronic components during the process of heat-pressing the electronic components together. It has become clear that heat may not be transferred properly to the adhesive in place. Therefore, the heat-resistant release film had poor thermal conductivity to electronic components.
In other words, the present inventors have found that conventional release films have a good balance between thermal conductivity to electronic components and mold releasability from electronic components when electronic components are heat-pressed to each other at high temperatures. We found that there is room for improvement in this regard.

The present invention has been made in view of the above circumstances, and provides a release film that has an excellent balance between thermal conductivity to the electronic components and releasability from the electronic components when heat-pressing electronic components together at high temperatures. It provides:

The present inventors have made extensive studies to achieve the above object. As a result, a release film comprising a thermally conductive layer (A), a heat-resistant resin layer (B), and a release layer (C) in this order has thermal conductivity to electronic components and release properties from electronic components. The present invention was based on the discovery that the balance between

According to the present invention, the following method of manufacturing a release film and an electronic device is provided.

[1]
A release film used for joining electronic components by heat and pressure bonding,
A release film comprising a thermally conductive layer (A), a heat-resistant resin layer (B), and a release layer (C) in this order.
[2]
In the release film described in [1] above,
When the thickness of the thermally conductive layer (A) is X ₁ [μm] and the thickness of the heat-resistant resin layer (B) is X ₂ [μm], X ₂ /X ₁ is 1.0 or less. Release film.
[3]
In the release film described in [1] or [2] above,
A release film in which the heat-resistant resin layer (B) has a thickness (X ₂ ) of 1 μm or more and less than 20 μm.
[4]
In the release film according to any one of [1] to [3] above,
A release film in which the release layer (C) contains a fluorine-based release agent.
[5]
In the release film described in [4] above,
A release film in which the fluorine-based mold release agent includes one or more structures selected from the group consisting of a perfluoroalkyl group and a perfluoropolyether skeleton.
[6]
In the release film described in [4] or [5] above,
The fluorine-based mold release agent is one or two selected from the group consisting of polytetrafluoroethylene, a copolymer of tetrafluoroethylene and hexafluoropropylene, and a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene. A release film containing the above fluororesin.
[7]
In the release film according to any one of [1] to [6] above,
A release film in which the thermally conductive layer (A) includes at least one selected from a metal foil, a graphite sheet, and a thermally conductive filler-containing resin layer.
[8]
In the release film described in [7] above,
A release film in which the thermally conductive layer (A) includes at least one selected from copper foil and aluminum foil.
[9]
In the release film according to any one of [1] to [8] above,
A release film in which the heat-resistant resin layer (B) has a storage modulus E' at 350° C. of 1.0×10 ⁵ Pa or more and 1.0×10 ⁸ Pa or less.
[10]
In the release film according to any one of [1] to [9] above,
A release film in which the heat-resistant resin layer (B) contains at least one resin selected from the group consisting of epoxy resin, thermoplastic polyimide, polyamide, polyamideimide, and polyetherimide.
[11]
In the release film according to any one of [1] to [10] above,
A release film in which the thickness of the release layer (C) is 10 μm or less.
[12]
In the release film according to any one of [1] to [11] above,
A release film in which the thickness of the release layer (C) is less than 0.1 μm.
[13]
In the release film according to any one of [1] to [12] above,
A release film further comprising a primer layer (P) between the heat-resistant resin layer (B) and the release layer (C).
[14]
In the release film described in [13] above,
A release film in which the primer layer (P) includes a layer having a siloxane bond.
[15]
In the release film according to any one of [1] to [14] above,
The release layer (C) includes a fluorine-based compound having a reactive group that can be bonded to a layer constituting the release film at a temperature of less than 200°C, which is in contact with the release layer (C). A release film containing a fluorine-based release layer obtained by reacting with a layer in contact with (C).
[16]
In the release film described in [15] above,
A release film in which the reactive group includes an alkoxysilyl group.
[17]
In the release film according to any one of [1] to [16] above,
The release film has a thickness of 100 μm or less.
[18]
In the release film according to any one of [1] to [17] above,
A release film further comprising a resin layer (D) on a surface of the thermally conductive layer (A) opposite to the surface on which the heat-resistant resin layer (B) is disposed.
[19]
In the release film described in [18] above,
A release film in which the resin layer (D) includes at least one resin layer selected from a release layer and a heat-resistant resin layer.
[20]
A manufacturing method for manufacturing an electronic device in which a first electronic component and a second electronic component are bonded via a thermosetting adhesive,
A distance according to any one of [1] to [19] above is provided between the second electronic component placed on the first electronic component and the heating head via the thermosetting adhesive. By pressing the second electronic component toward the first electronic component with the heating head with the mold film arranged so that the release layer (C) side faces the second electronic component, the second electronic component is pressed against the first electronic component. A method for manufacturing an electronic device, including the step of electrically connecting a first electronic component and a second electronic component by heat compression bonding.

According to the present invention, it is possible to provide a release film that has an excellent balance between thermal conductivity to the electronic component and releasability from the electronic component when electronic components are heat-pressed to each other at high temperatures.

1 is a cross-sectional view schematically showing an example of the structure of a release film according to an embodiment of the present invention. 1 is a cross-sectional view schematically showing an example of the structure of a release film according to an embodiment of the present invention. 1 is a cross-sectional view schematically showing an example of the structure of a release film according to an embodiment of the present invention. 1 is a cross-sectional view schematically showing an example of the structure of a release film according to an embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings. Note that, in all the drawings, similar constituent elements are given the same reference numerals, and description thereof will be omitted as appropriate. Furthermore, the figure is a schematic diagram and does not correspond to the actual dimensional ratio. In addition, the numerical range "A to B" represents A or more and B or less, unless otherwise specified.

1. Release Film The release film 50 according to this embodiment will be described below.
1 to 4 are cross-sectional views schematically showing an example of the structure of a release film 50 according to an embodiment of the present invention.

As shown in FIG. 1, the release film 50 according to the present embodiment is a release film used for joining electronic components by thermocompression bonding, and includes a thermally conductive layer (A), a heat-resistant resin layer (B) and a release layer (C) in this order.

As mentioned above, according to the studies of the present inventors, when placing an adhesive such as ACF or NCF between two electronic components and heat-pressing the electronic components together at high temperatures, the higher the temperature, the more the adhesive becomes weaker. It has become clear that because the resin component constituting the adhesive and the release film are melted and bonded together, a portion of the adhesive may adhere to the release film.
If some of the adhesive adheres to the release film, it will fall off into the production line, causing contamination or stoppage of the production line, and reducing product yield. There are concerns.

Although the detailed reason why a part of the adhesive adheres to the release film is not clear, the following reasons can be considered. When electronic components are bonded together under heat and pressure, for example, the release film is heated to 300° C. or higher. At this time, it is thought that the resin component constituting the adhesive is in a molten state, and the release layer of the release film is further softened and is in a state close to a molten state. Then, a portion of the molten adhesive and a portion of the release layer that is close to the molten state become compatible. As a result, when the release film is peeled off from the electronic component, some of the adhesive remains on the surface of the release layer of the release film, and as a result, some of the adhesive adheres to the release film. It is thought that this will happen.

On the other hand, by using a heat-resistant resin such as polyimide for the support layer, the heat resistance of the release film can be improved. However, according to studies by the present inventors, due to the increased thickness of the support layer, such a heat-resistant release film has a tendency to cause damage between two electronic components during the process of heat-pressing the electronic components together. It has become clear that heat may not be transferred properly to the adhesive in place. Therefore, the heat-resistant release film had poor thermal conductivity to electronic components.

Based on the above, the present inventors have found that conventional release films have a good balance between thermal conductivity to electronic components and mold releasability from electronic components when electronic components are heat-pressed together at high temperatures. We found that there is room for improvement in terms of improving performance.
Therefore, in order to realize a release film with an excellent balance between thermal conductivity to the electronic components and releasability from the electronic components when heat-pressing electronic components together at high temperatures, the present inventors After careful consideration. As a result, by providing the thermally conductive layer (A), the heat-resistant resin layer (B), and the release layer (C) in this order, it is possible to suppress the adhesion of adhesive when bonding electronic components together under heat and pressure. It was discovered for the first time that it is possible to improve mold releasability as well as improve thermal conductivity to electronic components.
The release film 50 according to the present embodiment includes the heat conductive layer (A) and the heat resistant resin layer (B), thereby improving the heat resistance of the release film 50 and the heat resistant resin layer (B). The thickness of the release film 50 can be made relatively thin, and as a result, the thermal conductivity of the release film 50 can be maintained well.
That is, the release film 50 according to the present embodiment includes a thermally conductive layer (A), a heat-resistant resin layer (B), and a release layer (C) in this order, so that electronic components can be heated together at high temperatures. When crimping, it is possible to achieve a good balance between thermal conductivity to the electronic component and releasability from the electronic component.

In the release film 50 according to the present embodiment, when the thickness of the thermally conductive layer (A) is X ₁ [μm] and the thickness of the heat-resistant resin layer (B) is X ₂ [μm], X ₂ / X ₁ is preferably 1.0 or less, more preferably 0.9 or less, and even more preferably 0.8 or less. By setting X ₂ /X ₁ to be less than or equal to the above upper limit value, it is possible to further improve the thermal conductivity to the electronic components when heat-pressing the electronic components together at high temperature, and also to improve the thermal conductivity of the release film 50. The occurrence of warpage can be suppressed.
Further, X ₂ /X ₁ is preferably 0.05 or more, more preferably 0.1 or more, even more preferably 0.3 or more, and even more preferably 0.4 or more. preferable. When X ₂ /X ₁ is greater than or equal to the above lower limit value, the heat resistance of the release film 50 is further improved, and when electronic components are heat-pressed to each other at high temperatures, the releasability from the electronic components is further improved. It can be made good.

The thickness (X ₂ ) of the heat-resistant resin layer (B) is preferably less than 20 μm, more preferably 19 μm or less, and even more preferably 18 μm or less. By having the thickness (X ₂ ) of the heat-resistant resin layer (B) less than or equal to the above upper limit value, the thermal conductivity to the electronic components is further improved when the electronic components are heat-pressed together at high temperatures. In addition, it is possible to suppress the occurrence of warping of the release film 50.
The thickness (X ₂ ) of the heat-resistant resin layer (B) is preferably 1 μm or more, more preferably 5 μm or more, and still more preferably 10 μm or more. By setting the thickness (X ₂ ) of the heat-resistant resin layer (B) to be equal to or greater than the above lower limit value, the heat resistance of the release film 50 is further improved, and when electronic components are heat-pressed together at high temperature, the electronic components The releasability from the mold can be further improved.

The thickness (X ₁ ) of the thermally conductive layer (A) is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 25 μm or less. When the thickness (X ₁ ) of the thermally conductive layer (A) is equal to or less than the above upper limit, the conveyance properties, handling properties, etc. of the release film 50 can be improved.
The thickness (X ₁ ) of the thermally conductive layer (A) is preferably 5 μm or more, more preferably 8 μm or more, and still more preferably 10 μm or more. When the thickness (X ₁ ) of the thermally conductive layer (A) is greater than or equal to the above lower limit, the thermal conductivity, transportability, handling characteristics, etc. of the release film 50 can be improved.

The thickness of the entire release film 50 according to this embodiment is preferably 100 μm or less, more preferably 60 μm or less, and even more preferably 40 μm or less, from the viewpoint of the balance between mechanical properties, thermal conductivity, and handleability. and more preferably 30 μm or less.

The shape of the release film 50 according to the present embodiment is not particularly limited, and examples thereof include a film shape, a sheet shape, a plate shape, and the like. Among these, film or sheet forms are preferred.

The release film 50 according to this embodiment is used for joining electronic components by heat and pressure bonding. More specifically, an adhesive such as ACF or NCF is placed between two electronic components and can be suitably used as a release film used in the process of heat-pressing the electronic components together.
However, the release film 50 according to the present embodiment is not limited to electrical connection between electronic components using adhesives such as ACF or NCF, and can be widely used for joining electronic components by thermocompression bonding. The types of electronic components to be bonded are not particularly limited, but include, for example, various substrates such as metal substrates and glass substrates (electrodes may be provided on the substrate); printed circuit boards, TCP (Tape Carrier Package), and FPC. Various circuits such as (Flexible Printed Circuit) (IC etc. may be provided on TCP or FPC); transparent conductive layers such as ITO (Indium Tin Oxide) layers; and the like.
The release film 50 can also be used to join electronic components in which a plurality of different electronic components are modularized.

Next, each layer constituting the release film 50 according to this embodiment will be explained.

<Thermal conductive layer (A)>
The thermally conductive layer (A) is a layer for efficiently transmitting heat from a heat source (for example, a heating and pressurizing head) to the electronic components when the electronic components are bonded together by thermocompression bonding.
The thermally conductive layer (A) is generally not limited as long as it has excellent thermal conductivity, and examples include metal foil, graphite sheet, and resin layer containing thermally conductive filler. These thermally conductive layers may be used alone or in combination of two or more. Among these, metal foil is preferred because it has excellent thermal conductivity and does not cause particles to fall off. Examples of the metal foil include nickel foil, stainless steel foil, titanium foil, silver foil, gold foil, molybdenum foil, copper foil, and aluminum foil. Furthermore, from the viewpoint of being inexpensive, at least one selected from copper foil and aluminum foil is more preferable.
Here, the thermal conductivity in the thickness direction of the thermally conductive layer (A) at 23°C is, for example, 0.5 W/(m·K) or more, preferably 1 W/(m·K) or more, more preferably is 10 W/(m·K) or more, more preferably 50 W/(m·K) or more, even more preferably 100 W/(m·K) or more. The upper limit of the thermal conductivity in the thickness direction of the thermally conductive layer (A) at 23° C. is not particularly limited, but is, for example, 6000 W/m·K or less. The thermal conductivity can be a value measured by a laser flash method.

The thermally conductive filler used in the thermally conductive filler-containing resin layer is not particularly limited, and examples thereof include boron nitride, aluminum nitride, silicon nitride, gallium nitride, aluminum hydroxide, magnesium hydroxide, silicon carbide, silicon dioxide, and silicon oxide. Aluminum, titanium oxide, zinc oxide, tin oxide, copper oxide, nickel oxide, antimonic acid-doped tin oxide, calcium carbonate, barium titanate, potassium titanate, copper, silver, gold, nickel, aluminum, platinum, carbon black, carbon Particles such as tubes (carbon nanotubes), carbon fibers, and diamonds can be used. Among these thermally conductive fillers, boron nitride, aluminum hydroxide, and aluminum oxide are preferred. These thermally conductive fillers may be used alone or in combination of two or more.
Although the resin used for the thermally conductive filler-containing resin layer is not particularly limited, for example, the heat-resistant resin used for the heat-resistant resin layer (B) described below can be used.

<Heat-resistant resin layer (B)>
The heat-resistant resin layer (B) is a layer containing a heat-resistant resin.
Here, in this embodiment, heat resistance means the dimensional stability and thermal decomposition stability of the resin layer at high temperatures. In other words, this means that the resin layer with better heat resistance is less likely to undergo deformation such as expansion, contraction, softening, melting, decomposition, etc. at high temperatures.
Furthermore, from the heat-resistant resin layer (B) according to the present embodiment, polyolefin resin layers such as the silicone rubber layer described in Patent Document 1 and the ultra-high molecular weight polyethylene layer described in Patent Document 2 are removed.
The heat-resistant resin layer (B) is not particularly limited, and examples include resin films.

The heat-resistant resin layer (B) contains a heat-resistant resin. As the heat-resistant resin constituting the heat-resistant resin layer (B), for example, a thermoplastic resin, a thermosetting resin, or a photocurable resin can be used. These heat-resistant resins may be used alone or in combination of two or more.

Further, a curing accelerator may be used to form the heat-resistant resin layer (B). Although the curing accelerator is not particularly limited, a thermal curing accelerator may be used, a photocuring accelerator may be used, or both may be used in combination. It is also possible to adjust the storage modulus E' at 350° C. of the heat-resistant resin layer (B) by adjusting the blending amount of such a curing accelerator.

In the release film 50 according to this embodiment, the storage modulus E' at 350° C. of the heat-resistant resin layer (B) is Preferably 1.0×10 ⁵ Pa or more, more preferably 1.0×10 ⁶ Pa or more, even more preferably 2.0×10 ⁶ or more, even more preferably 3.0×10 ⁶ or more, even more preferably It is 5.0×10 ⁶ or more.
Further, in the release film 50 according to the present embodiment, the storage modulus E' at 350° C. of the heat-resistant resin layer (B) is preferably 1.0×10 ⁸ Pa or less, more preferably 9.0×10 ⁷ Pa or less, more preferably 8.0×10 ⁷ Pa or less, even more preferably 6.0×10 ⁷ Pa or less, even more preferably 5.0×10 ⁷ Pa or less. This improves the ability to follow the irregularities formed on the surface of the electronic component, and prevents gaps from forming between the electronic component and the release film. As a result, the thermal conductivity to the electronic components can be further improved when the electronic components are bonded together by heat and pressure.
The storage modulus E' at 350°C of the heat-resistant resin layer (B) can be controlled within the above range by, for example, controlling the type and resin composition of the resin constituting the heat-resistant resin layer (B). .

Examples of the thermosetting resin include epoxy resin, phenol resin, unsaturated polyester resin, thermosetting polyimide resin, bismaleimide triazine resin, and benzoxazine resin.

Examples of thermoplastic resins include polyester, polyamide, thermoplastic polyimide, polyetherimide, polyamideimide, polycarbonate, modified polyphenylene ether, polyacetal, polyarylate, polysulfone, polyether sulfone, polyphenylene sulfide, polyether ether ketone, and liquid crystal polymer. , vinylidene chloride resin, polybenzimidazole, polybenzoxazole, and the like.
Among these, one or two selected from thermoplastic polyimide, polyamide, polyamideimide, polyetherimide, polyetheretherketone, and polyester from the viewpoint of excellent balance of heat resistance, mechanical strength, transparency, price, etc. The above are preferred, and one or more selected from thermoplastic polyimide, polyamide, polyamideimide, and polyetherimide are more preferred.

Examples of photocurable resins include acrylic resins or alkyd resins into which polymerizable unsaturated groups have been introduced, unsaturated polyester resins, and the like.

When the heat-resistant resin according to the present embodiment contains a thermosetting accelerator, the thermosetting accelerator is not particularly limited, but examples include aliphatic amines, aromatic amines, polyamide resins, secondary or tertiary amines, etc. , imidazoles, liquid polymercaptans, polysulfide resins, acid anhydrides, boron-amine complexes, dicyanamides, organic acid hydrazides, peroxides, and the like. These thermosetting accelerators may be used alone or in combination of two or more.

When the heat-resistant resin according to the present embodiment contains a photocuring accelerator, the photocuring accelerator is not particularly limited, but for example, a photoradical curing accelerator, a photocationic curing accelerator, a photoanionic curing accelerator, etc. Can be mentioned. These photocuring accelerators may be used alone or in combination of two or more. In addition, a sensitizer may be used in combination if necessary.
Although the photoradical curing accelerator is not particularly limited, examples thereof include alkylphenones, oxime esters, and organic phosphorus compounds.
Although the photocationic curing accelerator is not particularly limited, examples thereof include iodonium salts, sulfonium salts, and the like.
The photoanionic curing accelerator is not particularly limited, but examples thereof include oxime esters, aminium salts, and the like.

As the heat-resistant resin constituting the heat-resistant resin layer (B), epoxy resin, thermoplastic polyimide, polyamide, polyamide-imide, and polyether are used because of their excellent balance between elastic modulus and flexibility (cushioning properties) at high temperatures. One or more selected from the group consisting of imides is preferred.
Among these, epoxy resins are preferred, and thermosetting epoxy resins are more preferred. In the release film according to the present embodiment, the heat-resistant resin layer (B) containing an epoxy resin is preferably cured in advance before being used for joining electronic components by thermocompression bonding. By curing, it is possible to suppress the components contained in the heat-resistant resin layer (B) from bleeding out to the electronic component side.
Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, brominated bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol AF epoxy resin, and biphenyl epoxy resin. Resin, naphthalene type epoxy resin, fluorene type epoxy resin, phenol novolak type epoxy resin, orthocresol novolac type epoxy resin, trishydroxyphenylmethane type epoxy resin, tetraphenyloethane type epoxy resin, hydantoin type epoxy resin, trisglycidyl isocyanurate Examples include a type epoxy resin, a glycidylamine type epoxy resin, and the like.

As the thermoplastic polyimide, a conventionally known resin synthesized from a diamine and a tetracarboxylic dianhydride can be used. The thermoplastic polyimide according to this embodiment may be used alone, or may be a mixture of two or more.

Examples of diamines include m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, bis(3-aminophenyl) sulfide, (3-aminophenyl)(4 -aminophenyl) sulfide, bis(4-aminophenyl) sulfide, bis(3-aminophenyl) sulfoxide, (3-aminophenyl)(4-aminophenyl) sulfoxide, bis(3-aminophenyl) sulfone, (3- (aminophenyl)(4-aminophenyl) sulfone, bis(4-aminophenyl) sulfone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diamino Diphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis( 3-(3-aminophenoxy)phenoxy)benzene, 1,3-bis(3-(4-aminophenoxy)phenoxy)benzene, 1,3-bis(4-(3-aminophenoxy)phenoxy)benzene, 1, 3-bis(3-(3-aminophenoxy)phenoxy)-2-methylbenzene, 1,3-bis(3-(4-aminophenoxy)phenoxy)-4-methylbenzene, 1,3-bis(4- (3-aminophenoxy)phenoxy)-2-ethylbenzene, 1,3-bis(3-(2-aminophenoxy)phenoxy)-5-sec-butylbenzene, 1,3-bis(4-(3-aminophenoxy) ) phenoxy)-2,5-dimethylbenzene, 1,3-bis(4-(2-amino-6-methylphenoxy)phenoxy)benzene, 1,3-bis(2-(2-amino-6-ethylphenoxy) ) phenoxy)benzene, 1,3-bis(2-(3-aminophenoxy)-4-methylphenoxy)benzene, 1,3-bis(2-(4-aminophenoxy)-4-tert-butylphenoxy)benzene , 1,4-bis(3-(3-aminophenoxy)phenoxy)-2,5-di-tert-butylbenzene, 1,4-bis(3-(4-aminophenoxy)phenoxy)-2,3- Dimethylbenzene, 1,4-bis(3-(2-amino-3-propylphenoxy)phenoxy)benzene, 1,2-bis(3-(3-aminophenoxy)phenoxy)-4-methylbenzene, 1,2 -bis(3-(4-aminophenoxy)phenoxy)-3-n-butylbenzene, 1,2-bis(3-(2-amino-3-propylphenoxy)phenoxy)benzene, 4,4'-bis( 4-aminophenyl)-1,4-diisopropylbenzene, 3,4'-bis(4-aminophenyl)-1,4-diisopropylbenzene, 3,3'-bis(4-aminophenyl)-1,4- Diisopropylbenzene, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]methane, 1,1-bis[4-(3-aminophenoxy)phenyl]ethane, 1,1-bis[4-(4-aminophenoxy)phenyl]ethane, 1,2-bis[4-(3-aminophenoxy)phenyl]ethane, 1,2-bis[4-(4-aminophenoxy) phenyl]ethane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3 -aminophenoxy)phenyl]butane, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-( 4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy) Biphenyl, 3,3'-bis(4-aminophenoxy)biphenylbis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(3- Aminophenoxy)phenyl] sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfoxide, bis[4-(aminophenoxy)phenyl]sulfoxide, bis[4 -(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,3-bis[4 -(3-aminophenoxy)benzoyl]benzene, 4,4'-bis[3-(4-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[3-(3-aminophenoxy)benzoyl]diphenyl ether, 4 , 4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenylsulfone, Bis[4-{4-(4-aminophenoxy)phenoxy}phenyl]sulfone, 1,4-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4 -(4-aminophenoxy)-α,α-dimethylbenzyl]benzene and the like. Among them, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis(3-aminophenoxy)benzene, -aminophenyl) sulfone, bis(4-aminophenyl) sulfone, 4,4'-bis(4-aminophenyl)-1,4-diisopropylbenzene, 3,4'-bis(4-aminophenyl)-1, 4-diisopropylbenzene, 3,3'-bis(4-aminophenyl)-1,4-diisopropylbenzene, 3,3'-bis(4-aminophenoxy)biphenyl, 2,2'-bis(trifluoromethyl) Preferred examples include -1,1'-biphenyl-4,4'-diamine, 3,3'-dimethylbenzidine, 3,4'-dimethylbenzidine, and 4,4'-dimethylbenzidine. However, the diamine for obtaining thermoplastic polyimide is not limited to these.

Preferred examples of the tetracarboxylic dianhydride include 3,3',4,4'-biphenyltetracarboxylic dianhydride, which is biphenyltetracarboxylic dianhydride, and 1,1',2,2'-biphenyl. Tetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, Bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfide dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride -dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1, 3,3,3-hexafluoropropane dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride , 4,4'-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, 2,2-bis[(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,3,6,7 -Naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 2,2-bis(2 ,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, bis(2, 3-dicarboxyphenyl)ether dianhydride, bis(2,3-dicarboxyphenyl)sulfide dianhydride, bis(2,3-dicarboxyphenyl)sulfone dianhydride, 1,3-bis(2,3 -dicarboxyphenoxy)benzene dianhydride, 1,4-bis(2,3-dicarboxyphenoxy)benzene dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 4,4'- Isophthaloyl diphthalic anhydride, diazodiphenylmethane-3,3',4,4'-tetracarboxylic dianhydride, diazodiphenylmethane-2,2',3,3'-tetracarboxylic dianhydride, 2, 3,6,7-thioxanthone tetracarboxylic dianhydride, 2,3,6,7-anthraquinone tetracarboxylic dianhydride, 2,3,6,7-xanthone tetracarboxylic dianhydride, ethylenetetracarboxylic acid Examples include dianhydrides. However, the tetracarboxylic dianhydride for obtaining thermoplastic polyimide is not limited to these.

These heat-resistant resins may be used alone or in combination of two or more.

The heat-resistant resin layer (B) may be a single layer or may be a layer of two or more types.
Further, the form of the resin film used to form the heat-resistant resin layer (B) may be an unstretched film such as an extruded film or a cast film, or a film stretched in a uniaxial direction or biaxial direction. It may be. Although the heat-resistant resin layer (B) may be a film stretched in a uniaxial direction or biaxial direction, an unstretched film is preferable from the viewpoint of suppressing warping of the film.

The heat-resistant resin layer (B) may be surface-treated to improve adhesion with other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coat treatment, etc. may be performed.

<Release layer (C)>
The mold release layer (C) is a layer that has mold releasability, and is a layer that is placed facing the electronic components (i.e., a layer that is placed on the electronic component side) when electronic components are bonded together by thermocompression bonding. ), and is a layer provided for peeling off the release film 50 from the electronic components after the electronic components are bonded together by heat and pressure.
The release layer (C) is not particularly limited, and examples thereof include a coating layer, a resin film, and the like.
Here, in this embodiment, having mold releasability means, for example, when the contact angle with water is 80° or more.

Examples of the mold release agent for forming the mold release layer (C) include fluorine-based mold release agents, silicone-based mold release agents, silicone/fluorine-based mold release agents, hydrocarbon-based mold release agents, and the like. Here, the silicone/fluorine-based mold release agent means a mold release agent containing fluorine atoms and silicon atoms.
Among these, fluorine-based mold release agents are preferred from the viewpoint of further improving mold release properties.

The fluorine-based mold release agent preferably contains one or more fluorine-based compounds selected from fluorine-based resins and fluorine-containing compounds, from the viewpoint of further improving mold release properties, and contains perfluoroalkyl groups and More preferred are compounds containing one or more structures selected from the group consisting of perfluoropolyether skeletons.
Examples of the fluororesin constituting the release layer (C) include PTFE (polytetrafluoroethylene), PVDF (polyvinylidene fluoride), PCTFE (polychlorotrifluoroethylene), PVF (polyvinyl fluoride), PFA ( (copolymer of tetrafluoroethylene and perfluoroalkoxyethylene), FEP (copolymer of tetrafluoroethylene and hexafluoropropylene), ETFE (copolymer of tetrafluoroethylene and ethylene), ECTFE (chlorotrifluoroethylene) Examples include one or more selected from a copolymer of ethylene and ethylene), a terpolymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride, a fluororubber, and the like.
Among these, PTFE (polytetrafluoroethylene), FEP (a copolymer of tetrafluoroethylene and hexafluoropropylene), and PFA (a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene) have excellent mold release properties. One or more fluororesins selected from the group consisting of (combination) are more preferred.

The fluorine-based compound constituting the fluorine-based mold release agent has a temperature of less than 200°C with the layer constituting the mold release film that is in contact with the heat-resistant resin layer (B) and the release layer (C) such as the primer layer (P) described below. It is preferable to include a fluorine-based compound having a reactive group capable of bonding at a temperature of . Examples of the reactive group capable of bonding to the layer in contact with the release layer (C) at a temperature below 200°C include a hydroxyl group, a carboxyl group, an amino group, a vinyl group, a styryl group, a (meth)acrylic group, an epoxy group, Examples include mercapto group, alkoxysilyl group, and isocyanate group. Among these, alkoxysilyl groups are preferred because they can increase the concentration of fluorine-based compounds on the surface of the release film.
Examples of the alkoxysilyl group include a methoxysilyl group, an ethoxysilyl group, and an isopropoxysilyl group. From the viewpoint of reactivity, methoxysilyl group and ethoxysilyl group are preferred.

The fluorine-based compound constituting the fluorine-based mold release agent is one selected from the group consisting of a perfluoroalkyl group having 1 to 18 carbon atoms and a perfluoropolyether (PFPE) skeleton from the viewpoint of obtaining good mold release properties; Preferably, the compound contains two or more types of structures in the molecule.
The above perfluoroalkyl group having 1 to 18 carbon atoms preferably has 1 to 6 carbon atoms. The perfluoroalkyl group having 1 to 18 carbon atoms may be linear or branched.
Examples of compounds containing a perfluoropolyether (PFPE) skeleton in the molecule include silane compounds having perfluoropolyether chains, diol compounds having perfluoropolyether chains, linear perfluoroether compounds, etc. It will be done.
The fluorine-based compound preferably has an alkoxysilyl group or an alkylsiloxane bond from the viewpoint of obtaining good adhesion with the primer layer (P). Examples of compounds containing an alkoxysilyl group include compounds containing an alkoxy group having 1 to 18 carbon atoms, and examples of compounds having an alkylsiloxane bond include compounds containing a dimethylsiloxane bond having 1 to 18 carbon atoms.
These may be used alone or in combination of two or more.
Examples of such fluorine-based compounds include compounds disclosed in JP-A-2006-347062 and JP-A-2009-045867.

Furthermore, the release layer (C) may contain a conductive material. This makes it possible to suppress the generation of static electricity on the release film 50 during the process of joining electronic components together by thermocompression bonding, and it is possible to more stably join the electronic components. Although the conductive material is not particularly limited, examples thereof include carbon particles.

Further, the mold release layer (C) is preferably a fluorine-based coating layer, since the thickness of the mold release layer (C) can be reduced. If the coating layer is a fluorine-based coating layer, the thickness of the release layer (C) can be made thinner, so it is possible to further suppress the softening of the release layer (C) when electronic components are bonded together by heat and pressure, and as a result, It is possible to further prevent a portion of the melted adhesive from being compatible with a portion of the release layer (C). This makes it possible to further suppress adhesion of adhesive when electronic components are bonded together by heat and pressure.
The fluorine-based coating layer can be formed, for example, by applying a fluorine-based coating agent containing a fluorine-based compound such as the above-mentioned fluorine-based resin or fluorine-containing compound to the heat-resistant resin layer (B) and drying it. . Further, the fluorine-based coating agent may be a latex of a fluorine-based compound or a solution of a fluorine-based compound.

The thickness of the release layer (C) is preferably 10 μm or less, more preferably 5 μm or less, still more preferably 1 μm or less, even more preferably less than 0.1 μm, and particularly preferably from the viewpoint of further suppressing adhesive adhesion. is less than 0.01 μm. When the thickness of the release layer (C) is less than or equal to the above upper limit value, softening of the release layer (C) when heat-pressing electronic components is bonded to each other can be further suppressed, and as a result, the melted adhesive is It is possible to further prevent a part of the mold release layer (C) from being compatible with a part of the mold release layer (C).

The release layer (C) may be a single layer or may be a layer of two or more types.
Further, the release layer (C) may be subjected to surface treatment in order to improve adhesiveness with other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coat treatment, etc. may be performed.
In this embodiment, it is preferable that the release layer (C) is in direct contact with the heat-resistant resin layer (B).

<Resin layer (D)>
As shown in FIGS. 3 and 4, the release film 50 according to this embodiment has resin on the surface of the heat conductive layer (A) opposite to the surface on which the heat resistant resin layer (B) is disposed. It may further include a layer (D). Examples of the resin layer (D) include at least one resin layer selected from a release layer (D1) and a heat-resistant resin layer (D2).

The release layer (D1) may be the same as the release layer (C) described above. By providing the release film 50 with the release layer (D1), the releasability of the release film 50 from the heating head can be improved after the electronic components are bonded together by heat and pressure. This release layer (D1) is preferably provided as the outermost layer of the release film 50.

The thickness of the release layer (D1) is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 1 μm or less, even more preferably less than 0.1 μm, particularly preferably less than 0.01 μm.

The heat-resistant resin layer (D2) contains a heat-resistant resin. When the release film 50 includes the heat-resistant resin layer (D2), it is possible to further suppress warpage and deformation of the entire film that may occur when electronic components are bonded together by heat and pressure.
The heat-resistant resin layer (D2) preferably has a coefficient of linear expansion close to that of the heat-resistant resin layer (B), and more preferably the coefficient of linear expansion of the heat-resistant resin layer (D2) and that of the heat-resistant resin layer (B) are similar to that of the heat-resistant resin layer (B). Preferably, they are the same. Thereby, it is possible to further suppress warpage and deformation of the release film when electronic components are bonded together under heat and pressure, and to further improve productivity of electronic components.
Although the heat-resistant resin layer (D2) is not particularly limited, examples thereof include a resin film.

As the heat-resistant resin constituting the heat-resistant resin layer (D2), for example, a thermoplastic resin or a thermosetting resin can be used.

Examples of the thermosetting resin include epoxy resin, phenol resin, unsaturated polyester resin, thermosetting polyimide resin, bismaleimide triazine resin, and benzoxazine resin.

Examples of thermoplastic resins include polyester, polyamide, thermoplastic polyimide, polyetherimide, polyamideimide, polycarbonate, modified polyphenylene ether, polyacetal, polyarylate, polysulfone, polyether sulfone, polyphenylene sulfide, polyether ether ketone, and liquid crystal polymer. , vinylidene chloride resin, polybenzimidazole, polybenzoxazole, and the like.
Among these, one or two selected from thermoplastic polyimide, polyamide, polyamideimide, polyetherimide, polyetheretherketone, and polyester from the viewpoint of excellent balance of heat resistance, mechanical strength, transparency, price, etc. The above are preferred, and one or more selected from thermoplastic polyimide, polyamide, polyamideimide, and polyetherimide are more preferred.

As the heat-resistant resin constituting the heat-resistant resin layer (D2), epoxy resin, thermoplastic polyimide, polyamide, polyamide-imide, and polyether are used because of their excellent balance between elastic modulus and flexibility (cushioning properties) at high temperatures. One or more selected from the group consisting of imides is preferred.
Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, brominated bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol AF epoxy resin, and biphenyl epoxy resin. Resin, naphthalene type epoxy resin, fluorene type epoxy resin, phenol novolak type epoxy resin, orthocresol novolac type epoxy resin, trishydroxyphenylmethane type epoxy resin, tetraphenyloethane type epoxy resin, hydantoin type epoxy resin, trisglycidyl isocyanurate Examples include a type epoxy resin, a glycidylamine type epoxy resin, and the like. Furthermore, the epoxy resin can also be used as an epoxy resin composition in combination with a curing accelerator, as described in, for example, Japanese Patent No. 5,696,038.

As the thermoplastic polyimide, a conventionally known resin synthesized from a diamine and a tetracarboxylic dianhydride can be used. The thermoplastic polyimide according to this embodiment may be used alone, or may be a mixture of two or more.

Examples of diamines include m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, bis(3-aminophenyl) sulfide, (3-aminophenyl)(4 -aminophenyl) sulfide, bis(4-aminophenyl) sulfide, bis(3-aminophenyl) sulfoxide, (3-aminophenyl)(4-aminophenyl) sulfoxide, bis(3-aminophenyl) sulfone, (3- (aminophenyl)(4-aminophenyl) sulfone, bis(4-aminophenyl) sulfone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diamino Diphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis( 3-(3-aminophenoxy)phenoxy)benzene, 1,3-bis(3-(4-aminophenoxy)phenoxy)benzene, 1,3-bis(4-(3-aminophenoxy)phenoxy)benzene, 1, 3-bis(3-(3-aminophenoxy)phenoxy)-2-methylbenzene, 1,3-bis(3-(4-aminophenoxy)phenoxy)-4-methylbenzene, 1,3-bis(4- (3-aminophenoxy)phenoxy)-2-ethylbenzene, 1,3-bis(3-(2-aminophenoxy)phenoxy)-5-sec-butylbenzene, 1,3-bis(4-(3-aminophenoxy) ) phenoxy)-2,5-dimethylbenzene, 1,3-bis(4-(2-amino-6-methylphenoxy)phenoxy)benzene, 1,3-bis(2-(2-amino-6-ethylphenoxy) ) phenoxy)benzene, 1,3-bis(2-(3-aminophenoxy)-4-methylphenoxy)benzene, 1,3-bis(2-(4-aminophenoxy)-4-tert-butylphenoxy)benzene , 1,4-bis(3-(3-aminophenoxy)phenoxy)-2,5-di-tert-butylbenzene, 1,4-bis(3-(4-aminophenoxy)phenoxy)-2,3- Dimethylbenzene, 1,4-bis(3-(2-amino-3-propylphenoxy)phenoxy)benzene, 1,2-bis(3-(3-aminophenoxy)phenoxy)-4-methylbenzene, 1,2 -bis(3-(4-aminophenoxy)phenoxy)-3-n-butylbenzene, 1,2-bis(3-(2-amino-3-propylphenoxy)phenoxy)benzene, 4,4'-bis( 4-aminophenyl)-1,4-diisopropylbenzene, 3,4'-bis(4-aminophenyl)-1,4-diisopropylbenzene, 3,3'-bis(4-aminophenyl)-1,4- Diisopropylbenzene, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]methane, 1,1-bis[4-(3-aminophenoxy)phenyl]ethane, 1,1-bis[4-(4-aminophenoxy)phenyl]ethane, 1,2-bis[4-(3-aminophenoxy)phenyl]ethane, 1,2-bis[4-(4-aminophenoxy) phenyl]ethane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3 -aminophenoxy)phenyl]butane, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-( 4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy) Biphenyl, 3,3'-bis(4-aminophenoxy)biphenylbis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(3- Aminophenoxy)phenyl] sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfoxide, bis[4-(aminophenoxy)phenyl]sulfoxide, bis[4 -(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,3-bis[4 -(3-aminophenoxy)benzoyl]benzene, 4,4'-bis[3-(4-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[3-(3-aminophenoxy)benzoyl]diphenyl ether, 4 , 4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenylsulfone, Bis[4-{4-(4-aminophenoxy)phenoxy}phenyl]sulfone, 1,4-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4 -(4-aminophenoxy)-α,α-dimethylbenzyl]benzene and the like. Among them, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis(3-aminophenoxy)benzene, -aminophenyl) sulfone, bis(4-aminophenyl) sulfone, 4,4'-bis(4-aminophenyl)-1,4-diisopropylbenzene, 3,4'-bis(4-aminophenyl)-1, 4-diisopropylbenzene, 3,3'-bis(4-aminophenyl)-1,4-diisopropylbenzene, 3,3'-bis(4-aminophenoxy)biphenyl, 2,2'-bis(trifluoromethyl) Preferred examples include -1,1'-biphenyl-4,4'-diamine, 3,3'-dimethylbenzidine, 3,4'-dimethylbenzidine, and 4,4'-dimethylbenzidine. However, the diamine for obtaining thermoplastic polyimide is not limited to these.

Preferred examples of the tetracarboxylic dianhydride include 3,3',4,4'-biphenyltetracarboxylic dianhydride, which is biphenyltetracarboxylic dianhydride, and 1,1',2,2'-biphenyl. Tetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, Bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfide dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, bis(3,4-dicarboxyphenyl)sulfide dianhydride -dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1, 3,3,3-hexafluoropropane dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride , 4,4'-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, 2,2-bis[(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,3,6,7 -Naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 2,2-bis(2 ,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, bis(2, 3-dicarboxyphenyl)ether dianhydride, bis(2,3-dicarboxyphenyl)sulfide dianhydride, bis(2,3-dicarboxyphenyl)sulfone dianhydride, 1,3-bis(2,3 -dicarboxyphenoxy)benzene dianhydride, 1,4-bis(2,3-dicarboxyphenoxy)benzene dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 4,4'- Isophthaloyl diphthalic anhydride, diazodiphenylmethane-3,3',4,4'-tetracarboxylic dianhydride, diazodiphenylmethane-2,2',3,3'-tetracarboxylic dianhydride, 2, 3,6,7-thioxanthone tetracarboxylic dianhydride, 2,3,6,7-anthraquinone tetracarboxylic dianhydride, 2,3,6,7-xanthone tetracarboxylic dianhydride, ethylenetetracarboxylic acid Examples include dianhydrides. However, the tetracarboxylic dianhydride for obtaining thermoplastic polyimide is not limited to these.

These heat-resistant resins may be used alone or in combination of two or more.

The heat-resistant resin constituting the heat-resistant resin layer (D2) may be the same as or different from the heat-resistant resin constituting the heat-resistant resin layer (B), but from the viewpoint of suppressing warping and deformation of the film, it is preferable to use the same type of resin. It is more preferable that

The heat-resistant resin layer (D2) may be a single layer or may be a layer of two or more types.
Further, the form of the resin film used to form the heat-resistant resin layer (D2) may be an unstretched film such as an extruded film or a cast film, or a film stretched in a uniaxial direction or biaxial direction. It may be. From the viewpoint of improving the heat resistance and mechanical strength of the resin layer (D), the film may be uniaxially or biaxially stretched.

The thickness of the heat-resistant resin layer (D2) is preferably less than 20 μm, more preferably 19 μm or less, and even more preferably 18 μm or less. By having a thickness of the heat-resistant resin layer (D2) that is less than or equal to the above upper limit value, it is possible to further improve thermal conductivity to the electronic components when the electronic components are heat-pressed together at high temperatures. , the occurrence of warping of the release film 50 can be suppressed.
The thickness of the heat-resistant resin layer (D2) is preferably 5 μm or more, more preferably 8 μm or more, and even more preferably 10 μm or more. By having the thickness of the heat-resistant resin layer (D2) equal to or more than the above lower limit, the heat resistance of the release film 50 is further improved, and when electronic components are heat-pressed to each other at high temperatures, release from the electronic components is facilitated. properties can be further improved.

The resin layer (D) may be surface-treated to improve adhesion with other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coat treatment, etc. may be performed.

<Primer layer (P)>
The release film 50 according to the present embodiment is designed to improve the coating properties and releasability of the release layer (C), as shown in FIGS. 2 and 4. It is preferable to have a primer layer (P) between the adhesive resin layer (B) and the release layer (C). The primer layer (P) preferably has a siloxane bond (-Si-O-), a precursor of a silane compound having a siloxane bond, or a silanol group.
Examples of the primer layer having siloxane bonds or silanol groups include a silica film obtained by heating perhydropolysilazane (PHPS) in the air or a steam atmosphere, or a silica film obtained by a sol-gel reaction of alkoxysilane. Can be mentioned.

The thickness of the primer layer (P) is, for example, 0.001 μm or more and 1 μm or less.

<Other layers>
The release film 50 according to the present embodiment can be used between the heat-resistant resin layer (B) and the release layer (C), or between the heat-resistant resin layer (A) and the heat-resistant layer (A), within a range that does not impair the effects of the present embodiment. For example, an adhesive layer, an uneven absorption layer, a shock absorption layer, etc. may be further provided between the thermally conductive layer (B) and between the thermally conductive layer (A) and the resin layer (D). In the embodiment, the release layer (C) is preferably in direct contact with the heat-resistant resin layer (B).
Furthermore, the release film 50 according to the present embodiment has the following structure: release layer (C)/heat-resistant resin layer (B)/thermally conductive layer (A), or release layer (C)/heat-resistant resin layer (B). )/thermally conductive layer (A)/resin layer (D). For example, an adhesive layer, an uneven absorbing layer, a shock absorbing layer, etc. may be optionally provided between the layer and D).

2. Method for manufacturing the release film 50 The method for manufacturing the release film 50 according to the present embodiment is not particularly limited, and a generally known method for manufacturing a laminated film can be adopted. For example, the release film 50 according to the present embodiment is produced by using a known manufacturing method such as a coextrusion molding method, a lamination method, an extrusion coating method, or a coating method, either alone or in combination of two or more. be able to. Depending on the types of the thermally conductive layer (A), the heat-resistant resin layer (B), and the release layer (C), an appropriate manufacturing method can be selected from known methods for manufacturing laminated films.

3. Method for Manufacturing Electronic Devices The release film 50 according to this embodiment is used for joining electronic components by heat compression bonding. More specifically, the release film 50 according to this embodiment can be suitably used to manufacture an electronic device in which a first electronic component and a second electronic component are bonded via a thermosetting adhesive. Can be done.
The method for manufacturing an electronic device using the release film 50 according to the present embodiment includes, for example, a method of manufacturing an electronic device between a second electronic component placed on a first electronic component and a heating head via a thermosetting adhesive. , by pressing the second electronic component toward the first electronic component with the heating head with the release film 50 arranged so that the release layer (C) side faces the second electronic component, the first electronic component is heated. and a step of electrically connecting the second electronic component by heat compression bonding.
As the thermosetting adhesive, for example, a film adhesive such as a known anisotropic conductive film or a non-conductive adhesive film can be used. Further, a known anisotropic conductive adhesive paste or non-conductive adhesive paste may be used. The electronic components (first electronic component and second electronic component) are not particularly limited, but include, for example, semiconductor chips such as ICs, LSIs, discretes, light emitting diodes, and light receiving elements, semiconductor panels, and semiconductor packages.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above may also be adopted.

Note that the present invention is not limited to the above-described embodiments, and the present invention includes modifications, improvements, etc. within a range that can achieve the purpose of the present invention.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

<Materials>
Details of the materials used to produce the release film are as follows.

(Support layer (X))
X1: Polyimide film (manufactured by DuPont-Toray, product name: Kapton (registered trademark) 50H, thickness: 12.5 μm)

(Thermal conductive layer (A))
A1: Copper foil (manufactured by UACJ, thickness: 18 μm)
A2: Aluminum foil (manufactured by UACJ, thickness: 20 μm)

(Heat-resistant resin layer (B))
B1: Epoxy resin film (thickness: 15 μm, storage modulus E' at 350°C: 2.7×10 ⁷ Pa)
B2: Epoxy resin film (thickness: 20 μm, storage modulus E' at 350°C: 2.7×10 ⁷ Pa)

(Epoxy resin films (B1) and (B2))
Epoxy resin films (B1) and (B2) were prepared by the film forming method described in Japanese Patent No. 5,696,038 and then cured by further heating. The epoxy resin films (B1) and (B2) differ only in thickness and are made of the same epoxy resin.

(Release layer (C))
C1: Fluorine coating layer (manufactured by Fluoro Technology Co., Ltd., product name: Fluorosurf FG5020 (compound having a perfluoropolyether skeleton, containing functional group: alkoxysilyl group), thickness: <0.1 μm)
C2: Polytetrafluoroethylene (PTFE) film (film made using PTFE dispersion, thickness: 3 μm)

[Comparative example 1]
A heat-resistant resin layer (B1) was formed on the support layer (X1). Next, PC-3B (manufactured by Fluorotechnology, a silane compound having a siloxane bond) is coated on the heat-resistant resin layer (B1), and then left to dry at room temperature for 1 hour to form a 50 nm thick layer. A primer layer (P) was formed. Next, a release layer (C1) was formed by coating Fluorosurf FG5020 (manufactured by Fluoro Technology Co., Ltd.) on the primer layer (P) and drying it at a temperature of 130°C for 15 minutes to obtain a release film 1. Ta.

[Example 1]
A heat resistant resin layer (B2) was formed on the heat conductive layer (A1). Next, PC-3B (manufactured by Fluorotechnology, a silane compound having a siloxane bond) was applied on the heat-resistant resin layer (B2), and then left to dry at room temperature for 1 hour to form a 50 nm thick layer. A primer layer (P) was formed. Next, a release layer (C1) was formed by coating Fluorosurf FG5020 (manufactured by Fluoro Technology) on the primer layer (P) and drying it at a temperature of 130°C for 15 minutes to obtain a release film 2. Ta.

[Example 2]
A release film 3 was obtained in the same manner as in Example 1 except that the heat-resistant resin layer (B1) was used instead of the heat-resistant resin layer (B2).

[Example 3]
A release film 4 was obtained in the same manner as in Example 2 except that the thermally conductive layer (A2) was used instead of the thermally conductive layer (A1).

[Example 4]
A heat resistant resin layer (B1) was formed on the heat conductive layer (A1). Next, a PTFE dispersion was applied onto the heat-resistant resin layer (B1), dried at a temperature of 130°C for 5 minutes, and then heated at a temperature of 350°C for 5 minutes to form a release layer (C2). As a result, a release film 5 was obtained.

<Evaluation>
The release films obtained in Examples and Comparative Examples were evaluated as follows. The results obtained are shown in Table 1.
(1) Measurement of the storage modulus E' of the heat-resistant resin layer (B) at 350°C Using a solid viscoelasticity measurement device (RSA-3, manufactured by TA Instruments), the frequency was 1 Hz and the temperature increase rate was 3°C. The solid viscoelasticity of the heat-resistant resin layer (B) was measured under the following conditions: /min, strain 0.05%, distance between chucks 20 mm, sample width 10 mm, and the storage modulus of the heat-resistant resin layer (B) at 350°C. E' was calculated for each.

(2) Adhesion evaluation of adhesive when heat-pressing electronic components together (mold releasability evaluation)
NCF (underfill insulating film described in Example 1 of JP-A No. 2018-22819) was adhered onto a silicon wafer. Next, the release films obtained in the Examples and Comparative Examples were laminated on the NCF, and the resulting laminate was pressed for 30 seconds at 350° C. and a pressure of 0.6 MPa. Next, the laminate was cooled to room temperature, and then the release film was peeled off from the NCF. Next, the surface of the release film was observed, and the presence or absence of NCF adhesion was evaluated based on the following criteria.
◎: No powdery deposits were observed on the surface of the release film. ○: Very slight powdery deposits were observed on the surface of the release film. ×: No powdery deposits were observed on the surface of the release film. Kimono was observed

(3) Thermal conductivity test using a mounting bonder A chip-shaped object in which a thermocouple was sandwiched between a 10 mm square silicon wafer and a 10 mm square chip (manufactured by Woltz) with a bump of 3 μm in height was It was placed on a stage heated to ℃, and a release film was placed on top of it. Next, using a mounting bonder set at 310° C., the chip-shaped object was pressurized with a load of 10 N through the release film, and the temperature of the chip-shaped object was measured 15 seconds after the start of the pressurization.

(4) Evaluation of the curl strength of the release film The curl strength of the release film was evaluated by pressing a chip-shaped object through the release film with a load of 10 N using a mounting bonder set at 310°C. After that, when the release film was placed horizontally, the average height of the lift from the ground at both ends was measured and evaluated.
◎: Average value of lifting is less than 3 mm ○: Average value of lifting is 3 mm or more but less than 5 mm ×: Average value of lifting is 5 mm or more

In a thermal conductivity test using a mounting bonder, the film of the example, which includes a thermally conductive layer (A), a heat-resistant resin layer (B), and a release layer (C) in this order, had better thermal conductivity. It was confirmed that since the temperature of the chip-shaped object was higher than that of the release film of Comparative Example 1 which did not include the layer (A), heat could be transferred to the chip-shaped object better, and the film had excellent thermal conductivity. Note that in Example 1, the temperature of the chip-shaped object was higher than in Comparative Example 1 even though the thickness of the heat-resistant resin layer (B) was larger. From this, it can be understood that the film of Example 1 can transmit heat to the chip-shaped object better than the release film of Comparative Example 1, and has excellent thermal conductivity.

A Thermal conductive layer B Heat-resistant resin layer C Release layer D Resin layer P Primer layer 50 Release film

Claims (18)

A release film used for joining electronic components by heat and pressure bonding,
A release film comprising a thermally conductive layer (A), a heat-resistant resin layer (B) and a release layer (C) in this order,
When the thickness of the thermally conductive layer (A) is X ₁ [μm] and the thickness of the heat-resistant resin layer (B) is X ₂ [μm], X ₂ /X ₁ is 0.1 or more and 1. is less than or equal to 0,
A release film in which the heat-resistant resin layer (B) has a thickness (X ₂ ) of 1 μm or more and less than 20 μm . A release film used for joining electronic components by heat and pressure bonding,
A release film comprising a thermally conductive layer (A), a heat-resistant resin layer (B) and a release layer (C) in this order,
A release film further comprising a resin layer (D) on a surface of the thermally conductive layer (A) opposite to the surface on which the heat-resistant resin layer (B) is disposed. The release film according to claim 2,
A release film in which the resin layer (D) includes at least one resin layer selected from a release layer and a heat-resistant resin layer. The release film according to any one of claims 1 to 3 ,
A release film in which the release layer (C) contains a fluorine-based release agent. The release film according to claim 4 ,
A release film in which the fluorine-based mold release agent includes one or more structures selected from the group consisting of a perfluoroalkyl group and a perfluoropolyether skeleton. The release film according to claim 4 or 5 ,
The fluorine-based mold release agent is one or two selected from the group consisting of polytetrafluoroethylene, a copolymer of tetrafluoroethylene and hexafluoropropylene, and a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene. A release film containing the above fluororesin. The release film according to any one of claims 1 to 6 ,
A release film in which the thermally conductive layer (A) includes at least one selected from a metal foil, a graphite sheet, and a thermally conductive filler-containing resin layer. The release film according to claim 7 ,
A release film in which the thermally conductive layer (A) includes at least one selected from copper foil and aluminum foil. The release film according to any one of claims 1 to 8 ,
A release film in which the heat-resistant resin layer (B) has a storage modulus E' at 350° C. of 1.0×10 ⁵ Pa or more and 1.0×10 ⁸ Pa or less. The release film according to any one of claims 1 to 9 ,
A release film in which the heat-resistant resin layer (B) contains at least one resin selected from the group consisting of epoxy resin, thermoplastic polyimide, polyamide, polyamideimide, and polyetherimide. The release film according to any one of claims 1 to 10 ,
A release film in which the thickness of the release layer (C) is 10 μm or less. The release film according to any one of claims 1 to 11 ,
A release film in which the thickness of the release layer (C) is less than 0.1 μm. The release film according to any one of claims 1 to 12 ,
A release film further comprising a primer layer (P) between the heat-resistant resin layer (B) and the release layer (C). The release film according to claim 13 ,
A release film in which the primer layer (P) includes a layer having a siloxane bond. The release film according to any one of claims 1 to 14 ,
The release layer (C) contains a fluorine-based compound having a reactive group that can be bonded to a layer constituting the release film at a temperature of less than 200° C. and is in contact with the release layer (C). A release film containing a fluorine-based release layer obtained by reacting with a layer in contact with (C). The release film according to claim 15 ,
A release film in which the reactive group includes an alkoxysilyl group. The release film according to any one of claims 1 to 16 ,
The release film has a thickness of 100 μm or less. A manufacturing method for manufacturing an electronic device in which a first electronic component and a second electronic component are bonded via a thermosetting adhesive,
The release film according to any one of claims 1 to 17 is provided between the second electronic component placed on the first electronic component and the heating head via the thermosetting adhesive. By pressing the second electronic component toward the first electronic component with the heating head with the release layer (C) side facing the second electronic component, the first electronic component is heated. and a method for manufacturing an electronic device, including the step of electrically connecting the second electronic component by heat compression bonding.

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