JP6994578B2 - Release film - Google Patents

Description

The present invention relates to a release film.

In the manufacturing process of electronic devices, film-like adhesives such as Anisotropic Conductive Film (ACF) and Non Conductive Adhesive Film (NCF) are used in electronic devices. There is a process of electrically connecting various parts and members (hereinafter, also referred to as electronic parts) by heat crimping.
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 heat-bonded to each other, the thermosetting resin contained in the adhesive is cured by heat, and the electronic components can be joined to each other.
Here, in the step of heat-pressing the electronic parts with each other, a release film for preventing adhesion between the heat-pressurizing head part and the electronic parts between the heat-pressurizing head part for heating and pressurizing and the electronic parts. Is placed.

Examples of the technique 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 is a crimping and releasing sheet used for joining electronic parts by heat crimping, which includes a silicone rubber layer and a first porous polytetrafluoroethylene layer, and the first porous poly. Described is a crimp-release sheet 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 is a crimping and releasing sheet used for joining electronic parts by heat crimping, which includes an ultra-high molecular weight polyethylene layer and a silicone rubber layer, and includes the ultra-high molecular weight polyethylene layer and the silicone rubber layer. Is described as a pressure-bonded mold-removing sheet in which the above-mentioned ultra-high molecular weight polyethylene layers are integrated with each other and the thickness of the ultra-high molecular weight polyethylene layer is 30 μm or more.

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

By the way, in recent years, through silicon via (TSV) technology, which enables high density and miniaturization of semiconductor devices, has attracted attention and is being developed. By using this technology, semiconductor chips can be laminated to form a three-dimensional structure, so that it is possible to achieve a significantly higher density and smaller size than conventional devices.
In this technology, since the chips are stacked and then heat-bonded, the temperature of the heater is higher than before so that the heat is transferred to the chips in the lower layer. Along with this, further heat resistance is required for the release film as well.

According to the study by the present inventors, when electronic components are heat-bonded to each other by a heater via a release film, the semiconductor or metal material constituting the electronic component and the release film become more difficult to peel off as the temperature rises. Was found.
Conventionally, a fluorine-based resin film or a film coated with a fluorine-based resin on a support has been used as a release film for this purpose. When an adhesive such as ACF or NCF is placed between two electronic components and the electronic components are heat-bonded to each other, the higher the temperature, the more the resin component constituting the adhesive and the release film melt and fuse. Therefore, it became clear that a part of the adhesive may adhere to the release film.
If a part of the adhesive adheres to the release film, the adhesive attached to the release film will fall off during the production line, causing contamination or stoppage of the production line and reducing the yield of the product. There are concerns.

The present invention has been made in view of the above circumstances, and provides a release film capable of suppressing adhesion of an adhesive to a release layer when electronic components are heat-bonded to each other at a high temperature.

The present inventors have made extensive studies to achieve the above-mentioned problems. As a result, they have found that by using a heat-resistant resin layer and a release layer in combination, a release film capable of suppressing adhesion of an adhesive when heat-pressing electronic components with each other can be obtained, and the present invention is completed. I let you.

According to the present invention, the following release films are provided.

[1]
A mold release film used in the process of electrically connecting electronic components by heating and crimping them with an anisotropic conductive film or non-conductive adhesive film.
A release layer (B) arranged on one surface of the heat-resistant resin layer (A) is provided, and the thickness of the release layer (B) is 5 μm or less . ,
The release layer (B) is a release layer containing a fluorine-based compound having a reactive group that is in contact with the release layer (B) and can be bonded to the layer constituting the release film at a temperature of less than 200 ° C. Includes a fluorine-based mold release layer obtained by reacting with a layer in contact with (B).
A release film in which the reactive group contains an alkoxysilyl group .
[2]
In the release film according to the above [1],
A release film having a thickness of the release layer (B) of less than 0.1 μm.
[3]
In the release film according to the above [1] or [2],
A release film further comprising a primer layer (P) between the release layer (B) and the heat-resistant resin layer (A).
[4]
In the release film according to the above [3],
A release film containing a layer in which the primer layer (P) has a siloxane bond .
[5 ]
In the release film according to any one of the above [1] to [ 4 ].
A release film containing one or more structures in which the release layer (B) is selected from the group consisting of a perfluoroalkyl group and a perfluoropolyether skeleton.
[ 6 ]
In the release film according to any one of the above [1] to [ 5 ].
A release film having a thickness of 100 μm or less.
[ 7 ]
In the release film according to any one of the above [1] to [ 6 ].
A release film in which the heat-resistant resin layer (A) contains an epoxy resin.
[ 8 ]
In the release film according to any one of the above [1] to [ 7 ].
A heat-resistant resin layer (C) different from the heat-resistant resin layer (A) is provided on the surface of the heat-resistant resin layer (A) opposite to the surface on which the release layer (B) is arranged. A release film to be further prepared.
[ 9 ]
In the release film described in [ 8 ] above,
The heat-resistant resin constituting the heat-resistant resin layer (C) has a softening point, a glass transition temperature, or a melting point of 200 ° C. or higher, or the heat-resistant resin has a softening point, a glass transition temperature, or a melting point. A release film that does not have any.
[ 10 ]
In the release film according to the above [ 8 ] or [ 9 ],
The heat-resistant resin constituting the heat-resistant resin layer (C) is polyester, polyamide, polyimide, polyetherimide, polyamideimide, polycarbonate, modified polyphenylene ether, polyacetal, polyallylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyether. A release film containing one or more resins selected from the group consisting of ether ketones, liquid crystal polymers, vinylidene chloride resins, polybenzoimidazoles, polybenzoxazoles, polymethylpentene and silicone resins.
[ 11 ]
In the release film according to any one of the above [ 8 ] to [ 10 ].
A heat-resistant resin layer (D) of a type different from that of the heat-resistant resin layer (C) is placed on a surface of the heat-resistant resin layer (C) opposite to the surface on which the heat-resistant resin layer (A) is arranged. Further equipped with a release film.
[ 12 ]
In the release film described in [ 11 ] above,
A release film in which the heat-resistant resin layer (D) is a resin layer of the same type as the heat-resistant resin layer (A).

According to the present invention, it is possible to provide a release film capable of suppressing adhesion of an adhesive to a release layer when electronic components are heat-bonded to each other at a high temperature.

It is sectional drawing which shows typically an example of the structure of the release film of embodiment which concerns on this invention. It is sectional drawing which shows typically an example of the structure of the release film of embodiment which concerns on this invention. It is sectional drawing which shows typically an example of the structure of the release film of embodiment which concerns on this invention. It is sectional drawing which shows typically an example of the structure of the release film of embodiment which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, similar components are designated by a common reference numeral, and the description thereof will be omitted as appropriate. Further, the figure is a schematic view and does not match the actual dimensional ratio. Further, "A to B" in the numerical range represent A or more and B or less unless otherwise specified.

1. 1. Release film Hereinafter, the laminated body 50 according to the present embodiment will be described.
1 to 4 are cross-sectional views schematically showing an example of the structure of the release film 50 according to the 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 parts by heat crimping, and is a heat-resistant resin layer (A) and a heat-resistant resin layer (A). The release layer (B) arranged on one surface of the above) is provided, and the thickness of the release layer (B) is 5 μm or less.

According to the study by the present inventors, when an adhesive such as ACF or NCF is placed between two electronic parts and the electronic parts are heat-bonded to each other at a high temperature, the resin component constituting the adhesive and the resin component are used. It has been clarified that a part of the adhesive may adhere to the release film because it melts and fuses with the release film.
If a part of the adhesive adheres to the release film, the adhesive attached to the release film will fall off during the production line, causing contamination or stoppage of the production line and reducing the yield of the product. There are concerns.

The detailed reason why a part of the adhesive adheres to the release film is not clear, but the following reasons can be considered. When electronic components are heat-bonded to each other, for example, the release film is heated to 300 ° C. or higher. At this time, it is considered that the resin component constituting the adhesive is in a molten state, and the release layer of the release film is softened to be in a state close to the melted state. Then, a part of the melted adhesive and a part of the release layer close to the melted state are incompatible with each other. As a result, when the release film is peeled off from the electronic component, a part of the adhesive remains on the surface of the release layer of the release film, and as a result, a part of the adhesive adheres to the release film. It is thought that it will end up.
Therefore, the present inventors have made extensive studies in order to realize a release film capable of suppressing the adhesion of an adhesive when heat-pressing electronic components with each other. As a result, it was found for the first time that by using the heat-resistant resin layer (A) and the release layer (B) in combination, it is possible to suppress the adhesion of the adhesive when the electronic components are heat-bonded to each other.
That is, the release film 50 according to the present embodiment has a heat-resistant resin layer (A) and a release layer (B) arranged on one surface of the heat-resistant resin layer (A). It is possible to suppress the adhesion of the adhesive when the parts are heat-bonded to each other.
Further, by setting the film thickness of the release layer (B) to less than 0.1 μm, it is possible to further suppress the adhesion of the adhesive to the release layer (B) when the electronic components are heat-bonded to each other at a high temperature. I understood. Further, the release layer is a fluorine-based compound having a reactive group capable of binding the release layer (B) to a layer constituting the release film at a temperature of less than 200 ° C., which is in contact with the release layer (B). It has been found that the release property of the release layer (B) is further improved by forming a fluorine-based release layer obtained by reacting with the layer in contact with (B).

The thickness of the entire release film 50 according to the present embodiment is preferably 100 μm or less, more preferably 60 μm or less, still more preferably 40 μm or less, from the viewpoint of the balance of mechanical properties, thermal conductivity, and handleability. It is 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, and a plate shape. Of these, a film or sheet is preferable.

The release film 50 according to this embodiment is used for joining electronic components by heat crimping. More specifically, an adhesive such as ACF or NCF may be placed between the two electronic components, and the film can be suitably used as a release film used in the step of heat-pressing the electronic components with each other.
However, the release film 50 according to the present embodiment is not limited to the electrical connection between electronic parts using an adhesive such as ACF or NCF, and can be widely used for joining electronic parts by heat crimping. The type of electronic component to be joined is not particularly limited, but for example, various substrates such as a metal substrate and a glass substrate (an electrode may be provided on the substrate); a printed circuit board, a TCP (Tape Carrier Package), and an FPC. Various circuits such as (Flexible Printed Circuit) (ICs and the like may be provided on TCP and FPC); transparent conductive layers such as ITO (Indium Tin Oxide) layers; and the like.
The release film 50 can also be used for joining electronic components in which a plurality of different electronic components are modularized.

Next, each layer constituting the release film 50 according to the present embodiment will be described.

<Heat-resistant resin layer (A)>
The heat-resistant resin layer (A) is a layer containing a heat-resistant resin, and is a layer on the side heated by a heat source, that is, on the side in contact with the heating and pressurizing head portion when electronic components are joined by heat pressure bonding.
Here, in the present embodiment, the heat resistance means the dimensional stability and the thermal decomposition stability of the resin layer at a high temperature. That is, it means that the resin layer having better heat resistance is less likely to undergo deformation, melting, decomposition, etc. such as expansion, contraction, softening, etc. at high temperature.
Further, from the heat-resistant resin layer (A) according to the present embodiment, the silicone rubber layer described in Patent Document 1 and the polyolefin resin layer such as the ultra-high molecular weight polyethylene layer described in Patent Document 2 are included. Excluded.
The heat-resistant resin layer (A) is not particularly limited, and examples thereof include a resin film.

The heat-resistant resin layer (A) contains a heat-resistant resin. As the heat-resistant resin constituting the heat-resistant resin layer (A), 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 (A). The curing accelerator is not particularly limited, but a thermosetting accelerator may be used, a photocuring accelerator may be used, or both may be used in combination.

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

Examples of the thermoplastic resin include polyester, polyamide, polyimide, polyetherimide, polyamideimide, polycarbonate, modified polyphenylene ether, polyacetal, polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, liquid crystal polymer, and chloride. One or more selected from vinylidene resin, polybenzoimidazole, polybenzoxazole and the like can be mentioned.
Among these, one or more selected from polyimide, polyamide, polyetheretherketone and polyester are preferable from the viewpoint of excellent balance of heat resistance, mechanical strength, transparency, price and the like.

Examples of the photocurable resin include acrylic resins or alkyd resins having a polymerizable unsaturated group introduced therein, unsaturated polyester resins and the like.

When the heat-resistant resin according to the present embodiment contains a heat-curing accelerator, the heat-curing accelerator is not particularly limited, but for example, aliphatic amines, aromatic amines, polyamide resins, secondary or tertiary amines. , Imidazoles, liquid polypeptides, 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, and examples thereof include a photoradical curing accelerator, a photocationic polymerization initiator, and a photoanionic polymerization initiator. Can be mentioned. These photopolymerization initiators may be used alone or in combination of two or more. In addition, a sensitizer may be used in combination if necessary.
The photoradical curing accelerator is not particularly limited, and examples thereof include alkylphenones, oxime esters, and organic phosphorus compounds.
The photocationic curing accelerator is not particularly limited, and examples thereof include iodonium salts and sulfonium salts.
The photoanion curing accelerator is not particularly limited, and examples thereof include oxime esters and aminium salts.

As the heat-resistant resin constituting the heat-resistant resin layer (A), a thermosetting resin is preferable, and an epoxy resin is more preferable, from the viewpoint of excellent balance between elastic modulus at high temperature and flexibility (cushioning property).
Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, brominated bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol AF type epoxy resin, and biphenyl type epoxy. Resin, naphthalene type epoxy resin, fluonelen type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, trishydroxyphenylmethane type epoxy resin, tetraphenylol ethane type epoxy resin, hydantin type epoxy resin, trisglycidyl isocyanurate Examples thereof include a type epoxy resin and a glycidylamine type epoxy resin.
These heat-resistant resins may be used alone or in combination of two or more.

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

The heat-resistant resin layer (A) may contain a heat-conductive material from the viewpoint of improving the heat conductivity of the heat-resistant resin layer (A). The heat conductive material is not particularly limited, and examples thereof include inorganic fine particles such as alumina, magnesium oxide, silica, and titania.

The thickness of the heat-resistant resin layer (A) is preferably 1 μm or more and 60 μm or less, more preferably 1 μm or more and 40 μm or less, still more preferably 3 μm or more and 30 μm or less, still more preferably 5 μm or more, from the viewpoint of obtaining good film characteristics. It is 25 μm or less.
The heat-resistant resin layer (A) may be surface-treated in order to improve the adhesiveness with other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coating treatment and the like may be performed.

<Release layer (B)>
The release layer (B) is a layer having releasability, and is a layer arranged so as to face the electronic components when the electronic components are joined by heat crimping. It is a layer provided for peeling the release film 50 from the component.
The release layer (B) is not particularly limited, and examples thereof include a coating layer and a resin film.
Here, in the present embodiment, having releasability means, for example, a case where the contact angle with water is 80 ° or more.

Examples of the mold release agent for forming the release layer (B) include a fluorine-based mold release agent, a silicon-based mold release agent, a silicon / fluorine-based mold release agent, and a hydrocarbon-based mold release agent. Here, the silicon / fluorine-based mold release agent means a mold release agent having a fluorine atom and a silicon atom.
Among these, a fluorine-based mold release agent is preferable from the viewpoint of further improving the mold release property.

From the viewpoint of further improving the releasability, the fluorine-based mold release agent preferably contains one or more kinds of fluorine-based compounds selected from a fluorine-based resin and a fluorine-containing compound.
Examples of the fluororesin constituting the release layer (B) include PTFE (polytetrafluoroethylene), PVDF (polyfluorovinylidene), PCTFE (polychlorotrifluoroethylene), PVF (polyfluorovinyl), and PFA (polyfluorovinyl). Tetrafluoroethylene and perfluoroalkoxyethylene copolymer), FEP (tetrafluoroethylene and hexafluoropropylene copolymer), ETFE (tetrafluoroethylene and ethylene copolymer), ECTFE (chlorotrifluoro) (Polymer of ethylene and ethylene), a ternary copolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride, one or more selected from fluororubber and the like can be mentioned.

The fluorine-based compound constituting the fluorine-based mold release agent is less than 200 ° C. with the layer constituting the release film, which is in contact with the release layer (B) such as the heat-resistant resin layer (A) and the primer layer (P) described later. It is preferable to contain a fluorine-based compound having a reactive group capable of binding at the above temperature. Examples of the reactive group that can be bonded to the layer in contact with the release layer (B) at a temperature of less than 200 ° C. include a hydroxyl group, a carboxyl group, an amino group, a vinyl group, a styryl group, a (meth) acrylic group and an epoxy group. Examples thereof include a mercapto group, an alkoxysilyl group and an isocyanate group. Of these, the alkoxysilyl group is preferable because it can increase the concentration of the fluorine-based compound on the surface of the release film.
Examples of the alkoxysilyl group include a methoxysilyl group, an ethoxysilyl group, an isopropoxysilyl group and the like. From the viewpoint of reactivity, a methoxysilyl group and an ethoxysilyl group are preferable.

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. It is preferable that the compound contains two or more kinds of structures in the molecule.
The perfluoroalkyl group having 1 to 18 carbon atoms is more preferably 1 to 6 carbon atoms. The perfluoroalkyl group having 1 to 18 carbon atoms may be linear or branched.
Examples of the compound containing a perfluoropolyether (PFPE) skeleton in the molecule include a silane compound having a perfluoropolyether chain, a diol compound having a perfluoropolyether chain, and a linear perfluoroether compound. Will be.
The fluorine-based compound preferably has an alkoxysilane bond or an alkylsiloxane bond from the viewpoint of obtaining good adhesion to the primer layer (P). Examples of the compound containing an alkoxysilane bond include a compound containing an alkoxy group having 1 to 18 carbon atoms, and examples of the compound having an alkylsiloxane bond include a compound containing a dimethylsiloxane bond having 1 to 18 carbon atoms.
These may be used alone or in combination of two or more.
As such a fluorine-based compound, the compounds disclosed in JP-A-2006-347062 and JP-A-2009-045867 can be exemplified.

Further, the release layer (B) may contain a conductive material. As a result, it is possible to suppress the generation of static electricity on the release film 50 in the process of joining the electronic components by heat crimping, and the electronic components can be joined more stably. The conductive material is not particularly limited, and examples thereof include carbon particles and the like.

Further, the release layer (B) is preferably a fluorine-based coating layer from the viewpoint that the thickness of the release layer (B) can be reduced. With the fluorine-based coating layer, the thickness of the release layer (B) can be reduced, so that the softening of the release layer (B) when the electronic parts are heat-bonded to each other can be further suppressed, and as a result, the softening of the release layer (B) can be further suppressed. It is possible to further prevent the part of the melted adhesive and the part of the release layer (B) from being compatible with each other. This makes it possible to further suppress the adhesion of the adhesive when heat-pressing the electronic components with each other.
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 a fluorine-containing compound to the heat-resistant resin layer (A) 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 (B) is preferably 5 μm or less, more preferably 1 μm or less, still more preferably less than 0.1 μm, and particularly preferably less than 0.01 μm, from the viewpoint of further suppressing the adhesion of the adhesive. Is. When the thickness of the release layer (B) is equal to or less than the above upper limit value, the softening of the release layer (B) at the time of heat-bonding the electronic components can be further suppressed, and as a result, the melted adhesive can be melted. It is possible to further suppress the compatibility of a part with a part of the release layer (B).

The release layer (B) may be a single layer or two or more types of layers.
Further, the release layer (B) may be surface-treated in order to improve the adhesiveness with other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coating treatment and the like may be performed.

<Heat-resistant resin layer (C)>
The release film 50 according to the present embodiment has a surface on which the release layer (B) is arranged in the heat-resistant resin layer (A), as shown in FIG. 3, from the viewpoint of further suppressing the adhesion of the adhesive. It is preferable that the surface on the opposite side is further provided with a heat-resistant resin layer (C) of a type different from that of the heat-resistant resin layer (A). As a result, the softening of the release layer (B) when the electronic components are heat-bonded to each other can be further suppressed, and as a result, a part of the melted adhesive and a part of the release layer (B) are in phase. It is possible to further suppress melting. Here, the heat-resistant resin layer of a type different from the heat-resistant resin layer (A) means, for example, a heat-resistant resin layer having a different heat-resistant resin contained as a main component. The main component refers to the heat-resistant resin contained most.
The heat-resistant resin layer (C) is not particularly limited, and examples thereof include a resin film.

The heat-resistant resin layer (C) contains a heat-resistant resin.
Examples of the heat-resistant resin constituting the heat-resistant resin layer (C) include polyester, polyamide, polyimide, polyetherimide, polyamideimide, polycarbonate, modified polyphenylene ether, polyacetal, polyallylate, polysulfone, polyethersulfone, and polyphenylene sulfide. , Polyetheretherketone, liquid crystal polymer, vinylidene chloride resin, polybenzoimidazole, polybenzoxazole, polymethylpentene, silicone resin and the like, and one or more kinds of resins can be mentioned.
Among these, one or more selected from polyimide, polyamide, polyetheretherketone and polyester are preferable from the viewpoint of excellent balance of heat resistance, mechanical strength, transparency, price and the like.

The heat-resistant resin constituting the heat-resistant resin layer (C) preferably has a softening point, a glass transition temperature, or a melting point of 200 ° C. or higher, and more preferably 220 ° C. or higher. Alternatively, the heat-resistant resin constituting the heat-resistant resin layer (C) preferably has neither a softening point, a glass transition temperature, nor a melting point, and more preferably has a decomposition temperature of 200 ° C. or higher, and decomposes. It is more preferable that the temperature is 220 ° C. or higher.
When such a heat-resistant resin is used, the heat resistance of the heat-resistant resin layer (C) can be further improved.

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

The thickness of the heat-resistant resin layer (C) is preferably 5 μm or more and 400 μm or less, more preferably 10 μm or more and 200 μm or less, and further preferably 15 μm or more and 100 μm or less, from the viewpoint of obtaining good film characteristics.
The heat-resistant resin layer (C) may be surface-treated in order to improve the adhesiveness with other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coating treatment and the like may be performed.

<Primer layer (P)>
As shown in FIG. 2, the release film 50 according to the present embodiment is a lower layer of the release layer (B), that is, a release layer (from the viewpoint of improving the coatability and the release property of the release layer (B). It is preferable to have the primer layer (P) between the heat-resistant resin layer (A) and the heat-resistant resin layer (A). 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.
The primer layer having a siloxane bond or a silanol group includes, for example, a silica film obtained by heating perhydropolysilazane (PHPS) in the air or in 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.

<Heat-resistant resin layer (D)>
As shown in FIG. 4, the release film 50 according to the present embodiment has a heat-resistant resin layer (C) from the viewpoint of further suppressing warpage and deformation of the entire film that may occur when electronic parts are heat-bonded to each other. It is also preferable to further provide a heat-resistant resin layer (D) of a type different from that of the heat-resistant resin layer (C) on the surface opposite to the surface on which the heat-resistant resin layer (A) is arranged. The heat-resistant resin layer (D) preferably has a linear expansion coefficient close to that of the heat-resistant resin layer (A), and more preferably the linear expansion coefficient of the heat-resistant resin layer (D) and the heat-resistant resin layer (A). It is preferable that they are the same. As a result, it is possible to further suppress warpage and deformation of the release film when heat-bonding the electronic components to each other, and further improve the productivity of the electronic components.
The heat-resistant resin layer (D) is not particularly limited, and examples thereof include a resin film.

The heat-resistant resin layer (D) contains a heat-resistant resin. As the heat-resistant resin constituting the heat-resistant resin layer (D), 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, benzoxazine resin and the like.

Examples of the thermoplastic resin include polyester, polyamide, polyimide, polyetherimide, polyamideimide, polycarbonate, modified polyphenylene ether, polyacetal, polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, liquid crystal polymer, and chloride. One or more selected from vinylidene resin, polybenzoimidazole, polybenzoxazole and the like can be mentioned.
Among these, one or more selected from polyimide, polyamide, polyetheretherketone and polyester are preferable from the viewpoint of excellent balance of heat resistance, mechanical strength, transparency, price and the like.

As the heat-resistant resin constituting the heat-resistant resin layer (D), a thermosetting resin is preferable, and an epoxy resin is more preferable, from the viewpoint of excellent balance between elastic modulus at high temperature and flexibility (cushioning property).
Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, brominated bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol AF type epoxy resin, and biphenyl type epoxy. Resin, naphthalene type epoxy resin, fluonelen type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, trishydroxyphenylmethane type epoxy resin, tetraphenylol ethane type epoxy resin, hydantin type epoxy resin, trisglycidyl isocyanurate Examples thereof include a type epoxy resin and a glycidylamine type epoxy resin.
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 (D) may be the same as or different from the heat-resistant resin constituting the heat-resistant resin layer (A), but is the same from the viewpoint of suppressing warpage and deformation of the film. Is more preferable.

<Other layers>
The release film 50 according to the present embodiment has heat resistance between the heat-resistant resin layer (A) and the release layer (B) and between the heat-resistant resin layer (A) and the heat-resistant resin layer (A) as long as the effects of the present embodiment are not impaired. For example, an adhesive layer, an uneven absorption layer, a shock absorbing layer, or the like may be further provided between the heat-resistant resin layer (C) and between the heat-resistant resin layer (C) and the heat-resistant resin layer (D). ..

2. 2. Method for Producing Release Film 50 The method for producing the release film 50 according to the present embodiment is not particularly limited, and a generally known method for producing a laminated film can be adopted. For example, the release film 50 according to the present embodiment has a heat-resistant resin layer (A), a release layer (B), and if necessary, a heat-resistant resin layer (C) and a heat-resistant resin layer (D). It can be obtained by extrusion molding and laminating. Further, the release film 50 according to the present embodiment is, for example, a film-like heat-resistant resin layer (A), a film-like release layer (B), and, if necessary, a film-like heat-resistant resin layer (C). It can also be obtained by laminating (laminating) the heat-resistant resin layer (D). Further, the laminated body 50 according to the present embodiment can also be obtained by, for example, coating a release layer (B) on a film-shaped heat-resistant resin layer (A).
Further, the release film 50 according to the present embodiment can also be obtained by, for example, forming a primer layer (P) on the heat-resistant resin layer (A) and then coating the release layer (B). The method for forming the primer layer (P) and the release layer (B) is not particularly limited, and examples thereof include a method of applying and drying a compound solution forming each layer.

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

The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like to the extent that the object of the present invention can be achieved are included in the present invention.
Hereinafter, an example of the reference form will be added.
1. 1.
A mold release film used for joining electronic components by heat crimping.
A release layer (A) and a release layer (B) arranged on one surface of the heat-resistant resin layer (A) are provided, and the thickness of the release layer (B) is 5 μm or less. Mold film.
2. 2.
1. 1. In the release film described in 1.
A release film having a thickness of the release layer (B) of less than 0.1 μm.
3. 3.
1. 1. Or 2. In the release film described in 1.
A release film further comprising a primer layer (P) between the release layer (B) and the heat-resistant resin layer (A).
4.
3. 3. In the release film described in 1.
A release film containing a layer in which the primer layer (P) has a siloxane bond.
5.
1. 1. To 4. In the release film described in any one of
The release layer (B) is a release layer containing a fluorine-based compound having a reactive group that is in contact with the release layer (B) and can be bonded to the layer constituting the release film at a temperature of less than 200 ° C. A release film containing a fluorine-based release layer obtained by reacting with a layer in contact with (B).
6.
5. In the release film described in 1.
A release film in which the reactive group contains an alkoxysilyl group.
7.
1. 1. ~ 6. In the release film described in any one of
A release film containing one or more structures in which the release layer (B) is selected from the group consisting of a perfluoroalkyl group and a perfluoropolyether skeleton.
8.
1. 1. ~ 7. In the release film described in any one of
A release film having a thickness of 100 μm or less.
9.
1. 1. ~ 8. In the release film described in any one of
A release film in which the heat-resistant resin layer (A) contains an epoxy resin.
10.
1. 1. ~ 9. In the release film described in any one of
A heat-resistant resin layer (C) different from the heat-resistant resin layer (A) is provided on the surface of the heat-resistant resin layer (A) opposite to the surface on which the release layer (B) is arranged. A release film to be further prepared.
11.
10. In the release film described in 1.
The heat-resistant resin constituting the heat-resistant resin layer (C) has a softening point, a glass transition temperature, or a melting point of 200 ° C. or higher, or the heat-resistant resin has a softening point, a glass transition temperature, or a melting point. A release film that does not have any.
12.
10. Or 11. In the release film described in 1.
The heat-resistant resin constituting the heat-resistant resin layer (C) is polyester, polyamide, polyimide, polyetherimide, polyamideimide, polycarbonate, modified polyphenylene ether, polyacetal, polyallylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyether. A release film containing one or more resins selected from the group consisting of ether ketones, liquid crystal polymers, vinylidene chloride resins, polybenzoimidazoles, polybenzoxazoles, polymethylpentene and silicone resins.
13.
10. To 12. In the release film described in any one of
A heat-resistant resin layer (D) of a type different from that of the heat-resistant resin layer (C) is placed on a surface of the heat-resistant resin layer (C) opposite to the surface on which the heat-resistant resin layer (A) is arranged. Further equipped with a release film.
14.
13. In the release film described in 1.
A release film in which the heat-resistant resin layer (D) is a resin layer of the same type as the heat-resistant resin layer (A).

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

<Material>
Details of the materials used to prepare the release film are as follows.

(Heat-resistant resin layer (A))
A1: Epoxy resin film (thickness: 10 μm or 25 μm)
A2: Polyimide film (manufactured by Toray DuPont, product name: Kapton (registered trademark), thickness: 25 μm, glass transition temperature: 328 ° C)

(Release layer (B))
B1: Fluorine-based coating layer 1 (manufactured by Fluorotechnology, product name: Fluorosurf FG5020 (compound having a perfluoropolyether skeleton, contained functional group: alkoxysilyl group), thickness: <0.1 μm)
B2: PTFE film (manufactured by Nitto Denko, product name: NITOFLON film NO.900UL, thickness: 30 μm, melting point: 327 ° C)

(Heat-resistant resin layer (C))
C1: Polyimide film (manufactured by Toray DuPont, product name: Kapton (registered trademark), thickness: 25 μm, glass transition temperature: 328 ° C)

[Example 1]
Fluorosurf FG5020 (manufactured by Fluoro Technology) was applied onto the heat-resistant resin layer (A2). Then, it was dried at a temperature of 130 degreeC for 15 minutes to form a release layer (B1), and a release film 1 was obtained.
The following evaluation was performed on the obtained release film 1. The results obtained are shown in Table 1.

[Example 2]
After applying PC-3B (manufactured by Fluorotechnology, Inc., a silane compound having a siloxane bond) on the heat-resistant resin layer (A2), the primer layer having a thickness of 50 nm is dried by allowing it to stand at room temperature for 1 hour to dry. (P) was formed. Next, a release layer (B1) was formed by applying Fluorosurf FG5020 (manufactured by Fluoro Technology) on the primer layer (P) and drying at a temperature of 130 ° C. for 15 minutes to obtain a release film 2. rice field.

[Example 3]
A release film 3 was obtained in the same manner as in Example 2 except that the heat-resistant resin layer (A1) was used instead of the heat-resistant resin layer (A2). As the epoxy resin film, a film prepared by the film forming method described in Japanese Patent No. 5696038 and then cured by further heating was used. The obtained release films were evaluated in the same manner as in Example 1. The results obtained are shown in Table 1.

[Examples 4 and 5]
After laminating an uncured heat-resistant resin layer (A1) film on the heat-resistant resin layer (C1), the heat-resistant resin layer (A1) is cured by further heating to form a heat-resistant resin layer (A1) and a heat-resistant resin layer (C). A laminated film made of the above was produced. Next, PC-3B (manufactured by Fluorotechnology) was applied onto the heat-resistant resin layer (A1), and then allowed to stand at room temperature for 1 hour to dry to form a primer layer (P) having a thickness of 50 nm. Next, a release layer (B1) is formed by applying Fluorosurf FG5020 (manufactured by Fluoro Technology) on the primer layer (P) and drying at a temperature of 130 ° C. for 15 minutes to form release films 4 and 5. Was obtained respectively.
The thickness of the heat-resistant resin layer (A1) of Example 4 was 25 μm, and the thickness of the heat-resistant resin layer (A1) of Example 5 was 10 μm. The obtained release films were evaluated in the same manner as in Example 1. The results obtained are shown in Table 1.

[Comparative Example 1]
A PTFE film (release layer (B2)) was used as a release film, and the same evaluation as in Example 1 was performed. The results obtained are shown in Table 1.

[Comparative Example 2]
A PTFE film (release layer (B2)) was laminated on the heat-resistant resin layer (A2) to form a release film, and the same evaluation as in Example 1 was performed. The results obtained are shown in Table 1.

<Evaluation>
(1) Evaluation of Adhesive Adhesion When Electronic Components Are Heat-Crimped Together NCF (underfill insulating film described in Example 1 of Japanese Patent Application Laid-Open No. 2018-22819) was adhered onto a silicon wafer. Next, the release films obtained in Examples and Comparative Examples were laminated on NCF, and the obtained laminate was pressed for 30 seconds under the conditions of 330 ° C. and a crimping pressure of 0.6 MPa. The laminate was then cooled to room temperature and then the release film was stripped from the NCF. Next, the surface of the release film was observed, and the presence or absence of NCF adhesion was evaluated according to the following criteria.
⊚: No powdery deposits were observed on the surface of the release film 〇: Very slight powdery deposits were observed on the surface of the release film ×: Powdery deposits on the surface of the release film Kimono was observed

(2) Evaluation of peeling strength Using a polyimide adhesive tape (manufactured by Nitto Denko, tape width 25 mm) as an adherend, the release layer of each release film shown in the table and the adhesive layer of the polyimide adhesive tape are laminated so as to face each other. Then, the laminate was obtained by pressing at 330 ° C. and a pressure of 1 MPa. Then, a 180 ° peeling test was carried out, and the peeling strength between the polyimide adhesive tape and the release film was measured.

(3) Thermal conductivity test using a mounting bonder A chip-shaped object with a thermocouple sandwiched between two 10 mm square silicon wafers is placed on a stage heated to 150 ° C, and a release film is placed on it. did. Next, using a mounting bonder set at 330 ° C., the chip-shaped object was pressed through the release film for 30 seconds under a load of 10 N. At that time, the temperature of the chip-shaped object was measured, and the temperature difference between the bonder temperature (330 ° C.) and the chip-shaped object was calculated.

In the evaluation of adhesion of the adhesive when the electronic parts are heat-bonded to each other, the release film of the example has no adhesive adhesion or a slight adhesion when the electronic parts are heat-bonded to each other, and the release film is good. Shown the type. On the other hand, in the release film of the comparative example, adhesion of the adhesive was observed. Further, in the evaluation of the release strength, it was suggested that the release film of the example had a lower release strength and a higher release property than the film of the comparative example. Furthermore, in the thermal conductivity test using the mounting bonder, it was confirmed that the film having a thinner overall film thickness had a smaller temperature difference between the bonder and the chip and had better thermal conductivity. In addition, the release film having a primer layer (Examples 2 to 5) has less adhesion of NCF and lower peel strength than a film without a primer layer, and therefore has good release property. confirmed.

This application claims priority on the basis of Japanese Application Japanese Patent Application No. 2018-161770 filed on August 30, 2018 and incorporates all of its disclosures herein.

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

Claims (12)

A mold release film used in the process of electrically connecting electronic components by heating and crimping them with an anisotropic conductive film or non-conductive adhesive film.
A heat-resistant resin layer (A) and a release layer (B) arranged on one surface of the heat-resistant resin layer (A) are provided, and the thickness of the release layer (B) is 5 μm or less . ,
The release layer (B) is a release layer containing a fluorine-based compound having a reactive group that is in contact with the release layer (B) and can be bonded to the layer constituting the release film at a temperature of less than 200 ° C. Includes a fluorine-based mold release layer obtained by reacting with a layer in contact with (B).
A release film in which the reactive group contains an alkoxysilyl group . In the release film according to claim 1,
A release film having a thickness of the release layer (B) of less than 0.1 μm. In the release film according to claim 1 or 2.
A release film further comprising a primer layer (P) between the release layer (B) and the heat-resistant resin layer (A). In the release film according to claim 3,
A release film containing a layer in which the primer layer (P) has a siloxane bond. In the release film according to any one of claims 1 to 4 .
A release film containing one or more structures in which the release layer (B) is selected from the group consisting of a perfluoroalkyl group and a perfluoropolyether skeleton. In the release film according to any one of claims 1 to 5 .
A release film having a thickness of 100 μm or less. In the release film according to any one of claims 1 to 6 .
A release film in which the heat-resistant resin layer (A) contains an epoxy resin. In the release film according to any one of claims 1 to 7 .
A heat-resistant resin layer (C) different from the heat-resistant resin layer (A) is provided on the surface of the heat-resistant resin layer (A) opposite to the surface on which the release layer (B) is arranged. A release film to be further prepared. In the release film according to claim 8 ,
The heat-resistant resin constituting the heat-resistant resin layer (C) has a softening point, a glass transition temperature, or a melting point of 200 ° C. or higher, or the heat-resistant resin has a softening point, a glass transition temperature, or a melting point. A release film that does not have any. In the release film according to claim 8 or 9 .
The heat-resistant resin constituting the heat-resistant resin layer (C) is polyester, polyamide, polyimide, polyetherimide, polyamideimide, polycarbonate, modified polyphenylene ether, polyacetal, polyallylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyether. A release film containing one or more resins selected from the group consisting of ether ketones, liquid crystal polymers, vinylidene chloride resins, polybenzoimidazoles, polybenzoxazoles, polymethylpentene and silicone resins. In the release film according to any one of claims 8 to 10 .
A heat-resistant resin layer (D) of a type different from that of the heat-resistant resin layer (C) is placed on a surface of the heat-resistant resin layer (C) opposite to the surface on which the heat-resistant resin layer (A) is arranged. Further equipped with a release film. In the release film according to claim 11 ,
A release film in which the heat-resistant resin layer (D) is a resin layer of the same type as the heat-resistant resin layer (A).

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