JP7013875B2 - Laminated body, manufacturing method of laminated body, manufacturing method of flexible electronic device - Google Patents

Description

The present invention is a polymer film laminate having a silane coupling agent layer between an inorganic substrate and a polymer film layer (hereinafter, also referred to as “polymer film”), and manufactures a flexible electronic device. The present invention relates to a polymer film laminate that is useful for this purpose and has excellent recyclability of an inorganic substrate.

In recent years, technological development for forming these elements on a polymer film has been actively carried out for the purpose of reducing the weight, size and thickness, and flexibility of functional elements such as semiconductor elements, MEMS elements, and display elements. That is, as a material for a base material of electronic parts such as information communication equipment (broadcast equipment, mobile radio, portable communication equipment, etc.), radar, high-speed information processing device, etc., conventionally, it has heat resistance and a signal of information communication equipment. Ceramics that can handle higher frequencies in the band (reaching the GHz band) have been used, but since ceramics are not flexible and difficult to thin, there is a drawback that the applicable fields are limited, so recently. A polymer film is used as a substrate.

When forming functional elements such as semiconductor elements, MEMS elements, and display elements on the surface of polymer films, it is ideal to process them by a so-called roll-to-roll process that utilizes the flexibility that is a characteristic of polymer films. It is said that. However, in industries such as the semiconductor industry, the MEMS industry, and the display industry, process technologies for rigid flat substrates such as wafer-based or glass substrate-based have been constructed so far. Therefore, in order to form a functional element on a polymer film using the existing infrastructure, the polymer film is bonded to a rigid support made of an inorganic substance such as a glass plate, a ceramic plate, a silicon wafer, or a metal plate. A process is used in which a desired element is formed on the element and then peeled off from the support.

By the way, in the process of forming a desired functional element in a laminated body in which a polymer film and a support made of an inorganic substance are bonded together, the laminated body is often exposed to a high temperature. For example, in the formation of polysilicon, a step in a temperature range of about 200 to 500 ° C. is required. Further, in the production of a low-temperature polysilicon thin film transistor, heating at about 450 ° C. may be required for dehydrogenation, and in the production of a hydrided amorphous silicon thin film, a temperature of about 200 to 300 ° C. is applied to the film. There is. Therefore, the polymer film constituting the laminated body is required to have heat resistance, but as a practical matter, the polymer film that can withstand practical use in such a high temperature range is limited. In addition, it is generally conceivable to use an adhesive or an adhesive for bonding the polymer film to the support, but at that time, the bonding surface between the polymer film and the support (that is, the adhesive for bonding) Adhesive) is also required to have heat resistance. However, since ordinary adhesives and adhesives for bonding do not have sufficient heat resistance, bonding with an adhesive or adhesive cannot be applied when the formation temperature of the functional element is high.

Since there is no heat-resistant adhesive means for attaching the polymer film to the inorganic substrate, in such applications, a polymer solution or a polymer precursor solution is applied onto the inorganic substrate and dried and cured on the support to form a film. , The technology used for the application is known. However, since the polymer film obtained by such means is brittle and easily torn, the functional element formed on the surface of the polymer film is often broken when peeled from the support. In particular, it is extremely difficult to peel off a large-area film from a support, and it is not possible to obtain a yield that is approximately industrially viable.
In view of these circumstances, as a laminate of a polymer film and a support for forming a functional element, a polyimide film having excellent heat resistance, toughness, and thinning possible can be obtained from an inorganic substance via a silane coupling agent. A laminated body formed by bonding to a support (inorganic layer) has been proposed (Patent Documents 1 to 3).

By the way, the polymer film is originally a flexible material, and may be stretched or bent to some extent. On the other hand, functional elements formed on a polymer film often have a fine structure in which a conductor made of an inorganic substance and a semiconductor are combined in a predetermined pattern, such as minute expansion and contraction and bending and stretching. The stress destroys its structure and impairs its properties as an electronic device. Such stress is likely to occur when the polymer film is peeled off from the inorganic substrate together with the functional element. Therefore, in the laminated body described in Patent Documents 1 to 3, the structure of the functional element may be destroyed when the polymer film is peeled from the support.

Patent 5152104 Patent 5304490 Patent 5531781

Further, in these conventional techniques, when a high temperature of 420 ° C. or higher, preferably 460 ° C. or higher, more preferably 505 ° C. or higher is used for device manufacturing, the adhesiveness between the polyimide film and the inorganic substrate is increased and peeling is performed. Occasionally, a large tension is applied to the polyimide film (flexible substrate), which increases the risk of damage to the device.

(化学式１)

(Ａは置換基を有していても良い1価の有機基、Ｒ_１、Ｒ_２は炭素数１～６のアルキル基もしくはフェニル基、または、それらの置換体を示す。ｎは１または２の整数を示す。)
［２］前記化学式１のＡがアミノ基を有する有機基であることを特徴とする[１]に記載の積層体。
［３］ 該積層体を２００℃１時間熱処理した際の無機基板と高分子フィルムの９０度剥離強度が０．０５Ｎ／ｃｍ以上であり、該積層体を５００℃１時間熱処理した際の無機基板と高分子フィルムの９０度剥離強度が０．５０Ｎ／ｃｍ以下であることを特徴とする[１]または[２]に記載の積層体。
［４］前記無機基板として、ガラス板、セラミック板、シリコンウエハ、金属板から選ばれた一種が用いられていることを特徴とする請求項[１]～[３]のいずれかに記載の積層体。
［５］前記高分子フィルムとしてポリイミドフィルムを用いることを特徴とする[１]～[４]のいずれかに記載の積層体。
［６］[５]に記載のポリイミドフィルムの厚さが１μｍ～１００μｍであることを特徴とする[１]～ [５]のいずれかに記載の積層体。
［７］[５]、[６]に記載のポリイミドフィルムの１００℃～５００℃の温度範囲における線膨張係数（ＣＴＥ）が－５ｐｐｍ／℃～３０ｐｐｍ／℃であることを特徴とする[１]～[６]のいずれかにに記載の積層体。
[８] [５]～[７]に記載のポリイミドフィルムが芳香族テトラカルボン酸類とベンゾオキサゾール構造（骨格）を有する芳香族ジアミン類との反応によって得られるポリイミドフィルムであることを特徴とする[１]～[７]のいずれかに記載の積層体。
[９] 無機基板上にシランカップリング剤層を形成する工程と シランカップリング剤層の上に高分子フィルムを積層・加圧する工程と、加熱することで隣接する互いの層を接着する工程とを備えることを特徴とする積層体の製造方法。
[１０]
高分子フィルム上に電子デバイスを形成する工程と、高分子フィルム層に切り込みを入れ、高分子フィルム層の少なくとも一部を電子デバイスごと無機基板から剥離する工程とを備えることを特徴とするフレキシブル電子デバイスの製造方法。 That is, the present invention has the following configuration.
[1] In a laminate in which an inorganic substrate and a polymer film are bonded via a silane coupling agent layer, the silane coupling agent layer contains at least the silane coupling agent represented by Chemical Formula 1. body.

(Chemical formula 1)

(A is a monovalent organic group which may have a substituent, R ₁ and R ₂ are an alkyl group or a phenyl group having 1 to 6 carbon atoms, or a substituent thereof. N is 1 or 2. Indicates an integer of.)
[2] The laminate according to [1], wherein A of the chemical formula 1 is an organic group having an amino group.
[3] The 90-degree peel strength between the inorganic substrate and the polymer film when the laminate is heat-treated at 200 ° C. for 1 hour is 0.05 N / cm or more, and the inorganic substrate when the laminate is heat-treated at 500 ° C. for 1 hour. The laminate according to [1] or [2], wherein the polymer film has a 90-degree peel strength of 0.50 N / cm or less.
[4] The laminate according to any one of claims [1] to [3], wherein one selected from a glass plate, a ceramic plate, a silicon wafer, and a metal plate is used as the inorganic substrate. body.
[5] The laminate according to any one of [1] to [4], wherein a polyimide film is used as the polymer film.
[6] The laminate according to any one of [1] to [5], wherein the polyimide film according to [5] has a thickness of 1 μm to 100 μm.
[7] The polyimide film according to [5] and [6] is characterized in that the linear expansion coefficient (CTE) in the temperature range of 100 ° C. to 500 ° C. is −5 ppm / ° C. to 30 ppm / ° C. [1]. The laminate according to any one of [6].
[8] The polyimide film according to [5] to [7] is a polyimide film obtained by reacting an aromatic tetracarboxylic acid with an aromatic diamine having a benzoxazole structure (skeleton) [8]. 1] The laminate according to any one of [7].
[9] A step of forming a silane coupling agent layer on an inorganic substrate, a step of laminating and pressurizing a polymer film on the silane coupling agent layer, and a step of adhering adjacent layers by heating. A method for manufacturing a laminated body, which comprises the above.
[10]
A flexible electron comprising a step of forming an electronic device on a polymer film and a step of making a cut in the polymer film layer and peeling at least a part of the polymer film layer from the inorganic substrate together with the electronic device. How to make the device.

First, the effect of the present invention is to prevent peeling accidents even during the processing process by guiding the peeling strength during high-temperature treatment within the values described in the claims, and at the same time, easily make the device after device formation. The point is that it is possible to peel off from the inorganic substrate together with the polymer film.
The specific means for deriving the change pattern of the peel strength will be described in detail below, but basically, the structure of Chemical Formula 1 is formed on the silane coupling agent layer formed between the polymer film and the inorganic substrate. By using the silane coupling agent having a silane coupling agent, it is possible to peel off the device without damaging the device even after heat treatment at a high temperature without using a layer other than the silane coupling agent layer. However, it was found that when a silane coupling agent satisfying Chemical Formula 1 was used, the amount of alcohol volatilized during the high temperature heat treatment was reduced due to the small amount of alkoxy in the structure, and a substrate having a smoother surface state could be formed.

As a result, it has become possible to manufacture more precise devices while maintaining the property that the polymer film can be easily peeled off from the laminate after high temperature treatment of 500 ° C. or higher, resulting in higher productivity. It has improved significantly.

By using the polymer film laminate of the present invention, a flexible printed wiring board, a TAB tape, a COF, a dielectric element, a semiconductor element, a MEMS element, a display element, a light emitting element, a photoelectric conversion element, a piezoelectric conversion element, a thermoelectric conversion element, High yield of flexible electronic devices in which electromagnetic induction elements, print coils, print antennas, biosensors, electronic devices such as their composite elements, electromechanical devices, active elements, passive elements, etc. are formed on a polymer film. It will be feasible at.

Application of polymer solution or polymer precursor solution on the silane coupling agent layer is, for example, spin coating, doctor blade, applicator, comma coater, screen printing method, slit coating, reverse coating, dip coating, curtain coating. , Slit die coat and other conventionally known solution coating means can be appropriately used.
For example, in a polyimide resin film, a polyamic acid (polyimide precursor) solution obtained by reacting diamines and tetracarboxylic acids in a solvent is applied to an inorganic substrate to a predetermined thickness, dried, and then dried. It can be obtained by performing a thermal imidization method in which a dehydration ring closure reaction is carried out by high-temperature heat treatment, or a chemical imidization method using acetic anhydride or the like as a dehydrating agent and pyridine or the like as a catalyst.

In the present invention, the silane coupling agent means a compound that physically or chemically intervenes between the inorganic substrate and the polymer film layer and has an action of enhancing the adhesive force between the two.
The silane coupling agent is not particularly limited, but preferred specific examples of the silane coupling agent of Chemical Formula 1 include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane and 3-aminopropyl. Dimethoxymethylsilane, (3-aminopropyl) dimethylmethoxysilane, 3-aminopropyldiethoxymethylsilane, 3-aminopropyl) dimethylethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyl Examples thereof include diethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and a silane coupling agent having an amino group is more preferable.

In addition to the above, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane and N-2- (aminoethyl) -3-aminopropyltri are examples of the silane coupling agent that can be used in the present invention. Ethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, 2- (3,4-epoxycyclohexyl) ) Ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) Ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-Acryloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane , 3-Chloropropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isoxapropyltriethoxysilane, tris- (3-trimethoxysilylpropyl) isocyanurate, chloromethyl Phenethyltrimethoxysilane, chloromethyltrimethoxysilane, aminophenyltrimethoxysilane, aminophenetyltrimethoxysilane, aminophenylaminomethylphenetyltrimethoxysilane, n-propyltrimethoxysilane, butyltrichlorosilane, 2-cyanoethyltriethoxysilane, Cyclohexyltrichlorosilane, decyltrichlorosilane, diacetoxydimethylsilane, diethoxydimethylsilane, dimethoxydimethylsilane, dimethoxydiphenylsilane, dimethoxymethylphenylsilane, dodecyllichlorosilane, dodecyltrimethoxylan, ethyltrichlorosilane, hexyltrimethoxysilane, octadecyl Triethoxysilane, octadecyltrimethoxysilane, n-octyltrichlorosilane, n -Octyltriethoxysilane, n-octyltrimethoxysilane, triethoxyethylsilane, triethoxymethylsilane, trimethoxymethylsilane, trimethoxyphenylsilane, pentyltriethoxysilane, pentyllichlorosilane, triacetoxymethylsilane, trichlorohexylsilane , Trichloromethylsilane, Trichlorooctadecylsilane, Trichloropropylsilane, Trichlorotetradecylsilane, Trimethoxypropylsilane, Allyltrichlorosilane, Allyltriethoxysilane, Allyltrimethoxysilane, Diethoxymethylvinylsilane, Dimethoxymethylvinylsilane, Trichlorovinylsilane, Tri Uses ethoxyvinylsilane, vinyltris (2-methoxyethoxy) silane, trichloro-2-cyanoethylsilane, diethoxy (3-glycidyloxypropyl) methylsilane, 3-glycidyloxypropyl (dimethoxy) methylsilane, 3-glycidyloxypropyltrimethoxysilane, etc. You can also do it.

<Method of forming the silane coupling agent layer>
As a method for forming the silane coupling agent layer, a method of applying a silane coupling agent solution, a vapor deposition method, or the like can be used. The silane coupling agent layer may be applied to either the surface of the polymer film or the inorganic substrate, or may be applied to both surfaces.
As a method of applying the silane coupling agent solution, a spin coating method, a curtain coating method, a dip coating method, a slit die coating method, a gravure coating method, and a bar are used by using a solution obtained by diluting the silane coupling agent with a solvent such as alcohol. Conventionally known solution coating means such as a coating method, a comma coating method, an applicator method, a screen printing method, and a spray coating method can be appropriately used. When the method of applying the silane coupling agent solution is used, it is preferable to dry quickly after the application and further perform heat treatment at about 100 ° C. ± 30 ° C. for about several tens of seconds to about 10 minutes. By the heat treatment, the silane coupling agent and the surface of the surface to be coated are bonded by a chemical reaction.

Further, the silane coupling agent layer can also be formed by a vapor deposition method, and specifically, the substrate is formed by exposing the substrate to the vapor of the silane coupling agent, that is, the silane coupling agent in a substantially gaseous state. The vapor of the silane coupling agent can be obtained by heating the silane coupling agent in a liquid state to a temperature from 40 ° C. to about the boiling point of the silane coupling agent. The boiling point of the silane coupling agent varies depending on the chemical structure, but is generally in the range of 100 ° C to 250 ° C. However, heating at 200 ° C. or higher is not preferable because it may cause a side reaction on the organic group side of the silane coupling agent.
The environment for heating the silane coupling agent may be any of pressure, normal pressure, and reduced pressure, but in the case of promoting vaporization of the silane coupling agent, normal pressure or reduced pressure is preferable. Since many silane coupling agents are flammable liquids, it is preferable to carry out the vaporization work in a closed container, preferably after replacing the inside of the container with an inert gas.
The time for exposing the substrate to the silane coupling agent is not particularly limited, but is preferably 20 hours or less, more preferably 60 minutes or less, still more preferably 15 minutes or less, and most preferably 5 minutes or less.
The temperature of the substrate during exposure of the substrate to the silane coupling agent is controlled to an appropriate temperature between -50 ° C and 200 ° C depending on the type of silane coupling agent and the desired thickness of the silane coupling agent layer. It is preferable to do so.
It is preferable to clean the surface of the base material before the treatment with the silane coupling agent by means such as short wavelength UV / ozone irradiation or with a liquid detergent.

<Inorganic substrate>
In the present invention, an inorganic substrate is used as a support for the polymer film. Further, even in the case of forming an electronic device on a polymer film to manufacture a flexible electronic device, the inorganic substrate is used to temporarily support the polymer film material.
The inorganic substrate may be a plate-shaped substrate that can be used as a substrate made of an inorganic substance. For example, a glass plate, a ceramic plate, a semiconductor wafer, a metal or the like, and these glass plates, ceramic plates, etc. Examples of semiconductor wafers and composites of metals include those in which these are laminated, those in which they are dispersed, and those in which these fibers are contained.

Examples of the glass plate include quartz glass, high silicate glass (96% silica), soda lime glass, lead glass, aluminoborosilicate glass, borosilicate glass (Pylex (registered trademark)), borosilicate glass (non-alkali), and the like. Includes borosilicate glass (microsheet), aluminosilicate glass and the like. Among these, those having a linear expansion coefficient of 5 ppm / K or less are desirable, and if they are commercially available products, Corning Inc.'s "Corning (registered trademark) 7059" and "Corning (registered trademark) 1737", which are liquid crystal glass, are available. "EAGLE", "AN100" manufactured by Asahi Glass Co., Ltd., "OA10" manufactured by Nippon Electric Glass Co., Ltd., "AF32" manufactured by SCHOTT Co., Ltd., etc. are desirable.

The semiconductor wafer is not particularly limited, but is limited to silicon wafer, germanium, silicon-germanium, gallium-arsenic, aluminum-gallium-indium, nitrogen-phosphorus-arsenide-antimony, SiC, InP (indium phosphorus), InGaAs, GaInNAs, and the like. Wafers such as LT, LN, ZnO (zinc oxide), CdTe (cadmium telluride), and ZnSe (zinc selenide) can be mentioned. The wafer preferably used in the present invention is a silicon wafer, and particularly preferably a mirror-polished silicon wafer having a size of 8 inches or more.

Examples of the metal include single element metals such as W, Mo, Pt, Fe, Ni and Au, alloys such as inconel, monel, mnemonic, carbon copper, Fe—Ni based invar alloy and superinvar alloy. Further, a multilayer metal plate formed by adding another metal layer or a ceramic layer to these metals is also included. In this case, if the overall linear expansion coefficient (CTE) with the additional layer is low, Cu, Al, or the like is also used for the main metal layer. The metal used as the additional metal layer is limited as long as it has properties such as strong adhesion to the polymer film, no diffusion, and good chemical resistance and heat resistance. Although it is not a thing, Cr, Ni, TiN, Mo-containing Cu and the like can be mentioned as suitable examples.

It is desirable that the flat portion of the inorganic substrate is sufficiently flat. Specifically, the PV value of the surface roughness is 50 nm or less, more preferably 20 nm or less, and further preferably 5 nm or less. If it is coarser than this, the peel strength between the polymer film layer and the inorganic substrate may be insufficient.
The thickness of the inorganic substrate is not particularly limited, but is preferably 10 mm or less, more preferably 3 mm or less, still more preferably 1.3 mm or less, from the viewpoint of handleability. The lower limit of the thickness is not particularly limited, but is preferably 0.07 mm or more, more preferably 0.15 mm or more, still more preferably 0.3 mm or more.

The area of the inorganic substrate is preferably large from the viewpoint of production efficiency and cost of the polymer film laminate and the flexible electronic device. Specifically, it is preferably 1000 cm2 or more, more preferably 1500 cm2 or more, and even more preferably 2000 cm2 or more.

The polymer film in the present invention includes aromatic polyimides such as polyimide, polyamideimide, polyetherimide, and fluorinated polyimide, polyimide resins such as alicyclic polyimide, polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, and polyethylene-2. , Full aromatic polyester such as 6-naphthalate, Copolymerized polyester such as semi-aromatic polyester, Copolymerized (meth) acrylate represented by polymethylmethacrylate, Polycarbonate, Polyamide, Polysulphon, Polyethersulphon, Polyetherketone, Acetic acid Examples of films such as cellulose, cellulose nitrate, aromatic polyamide, polyvinyl chloride, polyphenol, polyarylate, polyphenylene sulfide, polyphenylene oxide, and polystyrene can be exemplified.
However, since the present invention is largely premised on being used in a process involving a heat treatment of 450 ° C. or higher, the polymer films exemplified above are limited to those that can be actually applied. The polymer film preferably used in the present invention is a film using a so-called super engineering plastic, preferably an aromatic polyimide film, an aromatic amide film, an aromatic amide imide film, and an aromatic benzoxazole. It is a film, an aromatic benzothiazole film, and an aromatic benzoimidazole film.

The details of the polyimide resin film will be described below. Generally, a polyimide-based resin film is a green film (hereinafter referred to as a green film) in which a polyamic acid (polyimide precursor) solution obtained by reacting diamines and tetracarboxylic acids in a solvent is applied to a support for producing a polyimide film and dried. It is also referred to as "polyamic acid film"), and is obtained by subjecting a green film to a high temperature heat treatment to carry out a dehydration ring closure reaction on a support for producing a polyimide film or in a state of being peeled off from the support.

The diamines constituting the polyamic acid are not particularly limited, and aromatic diamines, aliphatic diamines, alicyclic diamines and the like usually used for polyimide synthesis can be used. From the viewpoint of heat resistance, aromatic diamines are preferable, and among aromatic diamines, aromatic diamines having a benzoxazole structure are more preferable. When aromatic diamines having a benzoxazole structure are used, it is possible to develop high elastic modulus, low thermal shrinkage, and low linear expansion coefficient as well as high heat resistance. The diamines may be used alone or in combination of two or more.

The aromatic diamine having a benzoxazole structure is not particularly limited, and for example, 5-amino-2- (p-aminophenyl) benzoxazole, 6-amino-2- (p-aminophenyl) benzoxazole, 5 -Amino-2- (m-aminophenyl) benzoxazole, 6-amino-2- (m-aminophenyl) benzoxazole, 2,2'-p-phenylenebis (5-aminobenzoxazole), 2,2' -P-Phenylenebis (6-aminobenzoxazole), 1- (5-aminobenzoxazole) -4- (6-aminobenzoxazolo) benzene, 2,6- (4,4'-diaminodiphenyl) benzo [1,2-d: 5,4-d'] bisoxazole, 2,6- (4,4-diaminodiphenyl) benzo [1,2-d: 4,5-d'] bisoxazole, 2, 6- (3,4'-diaminodiphenyl) benzo [1,2-d: 5,4-d'] bisoxazole, 2,6- (3,4'-diaminodiphenyl) benzo [1,2-d: 4,5-d'] Bisoxazole, 2,6- (3,3'-diaminodiphenyl) benzo [1,2-d: 5,4-d'] Bisoxazole, 2,6- (3,3' -Diaminodiphenyl) benzo [1,2-d: 4,5-d'] bisoxazole and the like can be mentioned.

Examples of aromatic diamines other than the above-mentioned aromatic diamines having a benzoxazole structure include m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, and p-aminobenzylamine, 3. , 3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4'-Diaminodiphenylsulfoxide, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-diaminobenzophenone, 3,4'-diamino Benzophenone, 4,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 1,4-bis (3-aminophenoxy) benzene, 1,3 -Bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, and hydrogen atoms on the aromatic ring of the aromatic diamine. Part or all of a halogen atom, an alkyl group or an alkoxyl group having 1 to 3 carbon atoms, a cyano group, or a part or all of a hydrogen atom of an alkyl group or an alkoxyl group having 1 to 3 carbon atoms substituted with a halogen atom. Examples thereof include aromatic diamines substituted with an alkyl halide group or an alkoxyl group.

Examples of the aliphatic diamines include 1,2-diaminoethane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,8-diaminooctane and the like.
Examples of the alicyclic diamines include 1,4-diaminocyclohexane, 4,4'-methylenebis (2,6-dimethylcyclohexylamine) and the like.
The total amount of diamines (aliphatic diamines and alicyclic diamines) other than aromatic diamines is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less of all diamines. Is. In other words, the aromatic diamines are preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more of all diamines.

Examples of the tetracarboxylic acids constituting the polyamic acid include aromatic tetracarboxylic acids (including its acid anhydride), aliphatic tetracarboxylic acids (including its acid anhydride) and alicyclic tetracarboxylic acids usually used for polyimide synthesis. Acids (including its acid anhydride) can be used. Among them, aromatic tetracarboxylic acid anhydrides and alicyclic tetracarboxylic acid anhydrides are preferable, aromatic tetracarboxylic acid anhydrides are more preferable from the viewpoint of heat resistance, and alicyclics are more preferable from the viewpoint of light transmission. Group tetracarboxylic acids are more preferred. When these are acid anhydrides, the number of anhydride structures in the molecule may be one or two, but those having two anhydride structures (dianhydride) are preferable. good. The tetracarboxylic acids may be used alone or in combination of two or more.

Examples of the alicyclic tetracarboxylic acid include cyclobutanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 3,3', 4,4'-bicyclohexyltetracarboxylic acid and the like. Examples include carboxylic acids and their acid anhydrides. Among these, dianhydrides having two anhydride structures (eg, cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3', 4,4 '-Bicyclohexyltetracarboxylic dianhydride, etc.) is suitable. The alicyclic tetracarboxylic acids may be used alone or in combination of two or more.
When transparency is important, the alicyclic tetracarboxylic acids are preferably, for example, 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more of all tetracarboxylic acids.

The aromatic tetracarboxylic acids are not particularly limited, but are preferably pyromellitic acid residues (that is, those having a structure derived from pyromellitic acid), and more preferably an acid anhydride thereof. Examples of such aromatic tetracarboxylic acids include pyromellitic acid dianhydride, 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride, 4,4'-oxydiphthalic acid dianhydride, 3. , 3', 4,4'-benzophenone tetracarboxylic acid dianhydride and the like.
When heat resistance is important, the aromatic tetracarboxylic acids are preferably, for example, 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more of all tetracarboxylic acids.

The thickness of the polymer film of the present invention is preferably 1 μm to 100 μm, more preferably 3 μm to 90 μm, and even more preferably 24 μm to 80 μm.

The average CTE of the polymer film of the present invention between 100 ° C. and 500 ° C. is preferably −5 ppm / ° C. to + 30 ppm / ° C., more preferably −5 ppm / ° C. to + 15 ppm / ° C., and even more preferably. Is 1 ppm / ° C to + 10 ppm / ° C. When the CTE is within the above range, the difference in the linear expansion coefficient from the general support (inorganic substrate) can be kept small, and the polymer film and the inorganic substrate are peeled off even when subjected to the heat application process. It can be avoided. Here, CTE is a factor that represents reversible expansion and contraction with respect to temperature.

The thickness unevenness of the polymer film in the present invention is preferably 20% or less, more preferably 12% or less, still more preferably 7% or less, and particularly preferably 4% or less. When the thickness spot exceeds 20%, it tends to be difficult to apply to a narrow part. The film thickness unevenness can be obtained, for example, by randomly extracting about 10 positions from the film to be measured with a contact-type film thickness meter, measuring the film thickness, and using the following formula.
Film thickness spots (%)
= 100 x (maximum film thickness-minimum film thickness) ÷ average film thickness

The polymer film in the present invention is preferably obtained in the form of being wound as a long polymer film having a width of 300 mm or more and a length of 10 m or more at the time of its manufacture, and is a roll wound around a winding core. The one in the form of a polymer film is more preferable.

In the polymer film, in order to ensure handleability and productivity, a lubricant (particle) having a particle size of about 10 to 1000 nm is added / contained in the polymer film in an amount of about 0.03 to 3% by mass. It is preferable to impart fine irregularities to the surface of the polymer film to ensure slipperiness.

<Surface activation treatment of polymer film>
The polymer film used in the present invention may be subjected to a surface activation treatment. By subjecting the polymer film to a surface activation treatment, the surface of the polymer film is modified to a state in which functional groups are present (so-called activated state), and the adhesiveness to the inorganic substrate can also be controlled.
The surface activation treatment in the present invention is a dry or wet surface treatment. Examples of the dry surface treatment include vacuum plasma treatment, atmospheric pressure plasma treatment, treatment of irradiating the surface with active energy rays such as ultraviolet rays, electron beams, and X-rays, corona treatment, flame treatment, and itro treatment. can. Examples of the wet surface treatment include a treatment in which the surface of the polymer film is brought into contact with an acid or alkaline solution.

In the present invention, a plurality of surface activation treatments may be performed in combination. Such surface activation treatment cleans the surface of the polymer film and produces more active functional groups. The generated functional group is bound to the silane coupling agent layer by hydrogen bonds, chemical reactions, etc., and the polymer film layer and the silane coupling agent layer can be firmly adhered to each other.

<Heat and pressure treatment>
The laminate of the present invention is produced by laminating an inorganic substrate or a polymer film provided with a silane coupling agent layer via a silane coupling agent, heating the mixture, and then applying pressure treatment.

The pressure treatment may be performed, for example, in an atmospheric pressure atmosphere or in a vacuum by using a press, a laminate, a roll laminate, or the like. From the viewpoint of improving productivity and reducing the processing cost brought about by high productivity, pressing or roll laminating in an air atmosphere is preferable, and a method using rolls (roll laminating or the like) is particularly preferable.

The pressure during the pressurization treatment is preferably 1 MPa to 20 MPa, more preferably 3 MPa to 10 MPa. If the pressure is too high, the inorganic substrate may be damaged, and if the pressure is too low, there may be a portion that does not adhere to the substrate, resulting in insufficient adhesion. The temperature during the pressure heat treatment is 150 ° C. to 400 ° C., more preferably 250 ° C. to 350 ° C. When the polymer film is a polyimide film, if the temperature is too high, the polyimide film may be damaged, and if the temperature is too low, the adhesion tends to be weakened.
As a device that can be used for pressure heat treatment, for example, "11FD" manufactured by Imoto Seisakusho can be used for pressing in a vacuum, and a roll-type film laminator in a vacuum or a vacuum is used. For vacuum laminating such as a film laminator that applies pressure to the entire surface of the glass at once with a thin rubber film, for example, "MVLP" manufactured by Meiki Seisakusho can be used.
From the above, the laminate of the following (1) or (2) in the present invention can be obtained.

In the laminate obtained by the above, in which the inorganic substrate and the polymer film are adhered to each other via a silane coupling agent layer, the inorganic substrate and the polymer film are separated by 90 degrees when the laminate is heat-treated at 200 ° C. for 1 hour. The strength is preferably 0.05 N / cm or more, more preferably 0.1 N / cm or more. If it is 0.05 N / cm or less, the peel strength is too low, and there is a high possibility that the film will peel off from the glass before or during device formation. Further, the 90-degree peel strength between the inorganic substrate and the polymer film when the laminate is heat-treated at 500 ° C. for 1 hour is preferably 0.50 N / cm or less, more preferably 0.3 N / cm or less, still more preferably 0. It is 2 N / cm or less. If the peel strength exceeds 0.50 N / cm, it becomes difficult to peel the formed device without destroying it.

<Manufacturing method of flexible electronic device>
When the laminate of the present invention is used, an electronic device is formed on the polymer film of the laminate using existing equipment and processes for manufacturing electronic devices, and the polymer film is peeled off from the laminate to be flexible. Electronic devices can be made.
The electronic device in the present invention is a wiring board having a single-sided, double-sided, or multi-layer structure for electrical wiring, an active element such as a transistor or a diode, an electronic circuit including a passive device such as a resistor, a capacitor, or an inductor, and other pressures. , Sensor element that senses temperature, light, humidity, etc., biosensor element, light emitting element, liquid crystal display, electrophoretic display, image display element such as self-luminous display, wireless, wired communication element, arithmetic element, storage element, MEMS Refers to elements, solar cells, thin films, etc.

In the method for producing a device structure of the present invention, after the device is formed on the polymer film of the laminate produced by the above method, a cut is made in the polymer film of the laminate to form the polymer film. Peel off from the inorganic substrate.
As a method of making a cut in the polymer film of the easily peeling portion of the laminated body, a method of cutting the polymer film with a cutting tool such as a cutting tool or a method of scanning the polymer film relatively with a laser to obtain the polymer film. There are a method of cutting, a method of cutting the polymer film by relatively scanning the water jet and the laminate, and a method of cutting the polymer film while cutting a little to the glass layer by a dicing device of a semiconductor chip. The method is not limited. For example, in adopting the above-mentioned method, it is also possible to appropriately adopt a method such as superimposing ultrasonic waves on the cutting tool or adding a reciprocating motion or a vertical motion to improve the cutting performance.

The method of peeling the polymer film with the device from the inorganic substrate is not particularly limited, but the method of winding from the end with a tweezers or the like, or the tape portion after attaching the adhesive tape to one side of the notched portion of the polymer film. It is possible to adopt a method of winding from the surface, a method of vacuum-adsorbing one side of the cut portion of the polymer film, and then winding from that portion. At the time of peeling, if the cut portion of the polymer film is bent with a small curvature, stress will be applied to the device at that portion and the device may be destroyed. Therefore, peel it with the curvature as large as possible. Is desirable. For example, it is desirable to wind it while winding it on a roll having a large curvature, or to use a machine having a structure in which the roll having a large curvature is located at the peeling portion.
Further, it is also useful to attach another reinforcing base material to the part to be peeled off in advance and peel off the entire reinforcing base material. When the flexible electronic device to be peeled off is the backplane of the display device, it is also possible to attach the front plane of the display device in advance, integrate it on an inorganic substrate, and then peel off both at the same time to obtain a flexible display device. be.

<90 degree peel strength>
The peel strength of the laminate was measured according to the 90 degree peeling method.
N = 5 was measured with the polyimide film bent 90 degrees with respect to the inorganic substrate, and the average value was taken as the measured value.
Device name; Peeling tester ... Japan Measurement Systems Co., Ltd., JSV-H1000
Measurement temperature; room temperature
Peeling speed; 100 mm / min
Atmosphere; Atmosphere
Measurement sample width; 1 cm
<Number of bubbles>
A region of 3 cm × 3 cm was designated in the center of the laminate heat-treated at 500 ° C., and the number of bubbles in the region was visually confirmed from the side opposite to the film-attached surface.
<Manufacturing of polyimide film>

[Polymer Production Example 1]
After replacing the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer and a stirring rod with nitrogen, 223 parts by mass of 5-amino-2- (p-aminophenyl) benzoxazole (DAMBO) and N, N-dimethylacetamide 4416 The colloidal silica dispersion was added as a lubricant together with 217 parts by mass of pyromellitic dianhydride (PMDA), and the silica (lubricated material) contained the polymer solid content in the polyamic acid solution. The mixture was added so as to be 0.12% by mass based on the total amount, and the mixture was stirred at a reaction temperature of 25 ° C. for 24 hours to obtain a viscous polyamic acid solution V1.

[Polymer Production Example 2]
In Production Example 1, the same procedure was carried out except that the colloidal silica dispersion was not added, to obtain a polyamic acid solution V2.

(Polyimide film production example 1)
The polyamic acid solution V2 obtained above was applied to a smooth surface (non-slip material surface) of a long polyester film (“A-4100” manufactured by Toyobo Co., Ltd.) having a width of 1050 mm using a comma coater to form a final film thickness (imide). The film was applied so that the film thickness after conversion) was about 5 μm, and then the polyamic acid solution V1 was applied using a slit die so that the final film thickness including V2 was 38 μm, and the film was applied at 105 ° C. for 25 minutes. After drying, it was peeled off from the polyester film to obtain a self-supporting polyamic acid film having a width of 920 mm.
Then, the obtained self-supporting polyamic acid film was gradually heated in a temperature range of 180 ° C. to 495 ° C. by a pin tenter (first stage 180 ° C. × 5 minutes, second stage 220 ° C. × 5 minutes, The third stage was subjected to heat treatment (495 ° C. for 10 minutes) to imidize, and the pin gripping portions at both ends were dropped by slits to obtain a long polyimide film (1000 m roll) having a width of 850 mm. The thickness of the polyimide film actually obtained was 36 μm.

<Formation of silane coupling agent layer on substrate>
A silane coupling agent layer was formed by the following method using an inorganic substrate or an inorganic substrate after forming a thin film as a base material.

<Formation of silane coupling agent layer on inorganic substrate>
<Application example 1 (spin coating method)>
A silane coupling agent diluted solution was prepared by diluting with isopropanol so as to contain 1% by mass of 3-aminopropyldimethoxymethylsilane (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter SM2) as a silane coupling agent. The inorganic substrate was placed on a pin coater (MSC-500S manufactured by Japan Create Co., Ltd.), the rotation speed was increased to 2000 rpm, and the mixture was rotated for 10 seconds to apply a diluted solution of a silane coupling agent. Next, the inorganic substrate G1 coated with the silane coupling agent is placed on a hot plate heated to 110 ° C. so that the silane coupling agent coating surface faces up, and the mixture is heated for about 1 minute to apply the silane coupling agent. Obtained a substrate.
<Coating example 2 (gas phase coating method)>
A suction bottle connected to the chamber was filled with 100 parts by mass of the silane coupling agent SM2 and allowed to stand on a water bath at 40 ° C. By sealing the instrumentation air from above the suction bottle so that it can be introduced, the vapor of the silane coupling agent can be introduced into the chamber. Next, the inorganic substrate was held horizontally in the chamber with the UV irradiation surface facing up, and the chamber was closed. Next, instrumentation air was introduced at 25 L / min, and the inside of the chamber was held for 3 minutes while being filled with the silane coupling agent vapor to expose the inorganic substrate to the silane coupling agent vapor to obtain a silane coupling agent coated substrate. rice field.

(Example 1)
A silane coupling agent-coated substrate was prepared according to Application Example 1 to obtain a silane coupling agent-coated substrate. Next, the surface treated with the coupling agent and the polyimide film obtained in the production example were bonded together and laminated using a laminator manufactured by MCK to obtain a laminated body. Next, heat treatment was performed at 200 ° C. for 1 hour in an air atmosphere to obtain the laminated body A1 of the present invention. Next, A1 was further heat-treated at 500 ° C. for 1 hour in a nitrogen atmosphere to obtain a laminated body B1. The number of bubbles in B1 was confirmed, and the peel strength was measured for A1 and B1. The evaluation results are shown in Table 1.

(Example 2)
Except for changing the silane coupling agent to a silane coupling agent diluted solution diluted with isopropanol so as to contain SM2 and (3-aminopropyl) dimethylmethoxysilane (manufactured by Oakwood, hereinafter SM1) in an amount of 0.5% by mass, respectively. Laminates A2 and B2 were obtained in the same manner as in Example 1. The evaluation results are shown in Table 1.

(Example 3)
The ratio of the mixed solution of Example 2 was 3-aminopropyltriethoxysilane (manufactured by Shinetsu Silicone Co., Ltd., hereinafter SE3, 0.5% by mass), 3-aminopropyldiethoxymethylsilane (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter SE2, Laminates A3 and B3 were obtained in the same manner as in Example 1 except that the ratio was 0.5% by mass). The evaluation results are shown in Table 1.

(Example 4)
Except that the ratio of the mixed solution of Example 2 was a mixed solution of SE3 (0.5% by mass) and (3-aminopropyl) dimethylethoxysilane (manufactured by Wako Pure Chemical Industries, Ltd., hereinafter SE1, 0.5% by mass). Obtained laminated bodies A4 and B4 in exactly the same manner as in Example 1. The evaluation results are shown in Table 1.

(Example 5)
Laminates A5 and B5 were obtained in exactly the same manner as in Example 1 except that the ratio of the mixed solution of Example 2 was SE2 (0.5% by mass) and SE1 (0.5% by mass). The evaluation results are shown in Table 1.

(Example 6)
Laminates A6 and B6 were obtained in exactly the same manner as in Example 1 except that the ratio of the mixed solution of Example 2 was SM2 (0.2% by mass) and SM1 (0.8% by mass). The evaluation results are shown in Table 1.

(Example 7)
Exactly the same as in Example 1 except that the ratio of the mixed solution of Example 2 was 3-aminopropyltrimethoxysilane (manufactured by Shinetsu Silicone Co., Ltd., hereinafter SM3, 0.2% by mass) and SM1 (0.8% by mass). The laminated bodies A7 and B7 were obtained. The evaluation results are shown in Table 1.

(Example 8)
Laminates A8 and B8 were obtained in exactly the same manner as in Example 1 except that the ratio of the mixed solution of Example 2 was SM3 (0.2% by mass) and SE2 (0.8% by mass). The evaluation results are shown in Table 1.

(Example 9)
Laminates A9 and B9 were obtained in exactly the same manner as in Example 1 except that the ratio of the mixed solution of Example 2 was SM3 (0.2% by mass) and SE1 (0.8% by mass). The evaluation results are shown in Table 1.

(Example 10)
Laminates A10 and B10 were obtained in exactly the same manner as in Example 1 except that the ratio of the mixed solution of Example 2 was SM2 (0.2% by mass) and SE3 (0.8% by mass). The evaluation results are shown in Table 1.

なお表中 SCAはシランカップリング剤である。

In the table, SCA is a silane coupling agent.

(Example 11)
Laminates A11 and B11 were obtained in exactly the same manner as in Example 1 except that the silane coupling agent coated substrate was prepared according to Coating Example 2. The evaluation results are shown in Table 2.

(Example 12)
Exactly the same as in Application Example 2 except that the silane coupling agent SM2, 100 parts by mass and SM1, 100 parts by mass were filled in different suction bottles connected to the chamber from two directions and allowed to stand on a water bath at 40 ° C. A silane coupling agent-coated substrate was prepared, and laminates A11 and B11 were obtained in exactly the same manner as in Example 2. The evaluation results are shown in Table 2.

(Example 13)
A silane coupling agent-coated substrate was prepared in the same manner as in Example 12 except that the silane coupling agents used were changed to SE3 and SE2, and laminates A13 and B13 were obtained in the same manner as in Example 3. The evaluation results are shown in Table 2.

(Comparative Example 1)
A polymer film laminate C1 was obtained in exactly the same manner as in Example 1 except that the silane coupling agent used in Example 1 was changed to SM3 (1.0% by mass) only. The evaluation results are shown in Table 3.

(Comparative Example 2)
A polymer film laminate C2 was obtained in exactly the same manner as in Example 1 except that the silane coupling agent used in Example 1 was changed to SE3 (1.0% by mass) only. The evaluation results are shown in Table 3.

(Comparative Example 3)
A polymer film laminate C3 was obtained in exactly the same manner as in Comparative Example 1 except that the method for producing the silane coupling agent-coated substrate was changed to the air layer coating method. The evaluation results are shown in Table 3.

As described above, in the polymer film / inorganic substrate laminate of the present invention, after forming an electronic device on the polymer film, the polymer film on which the electronic device is placed is easily peeled off from the inorganic substrate. It is possible.
In particular, since one surface of the inorganic substrate and the polymer film are bonded with a silane coupling agent layer containing a silane coupling agent having a specific structure, the temperature is close to 500 ° C. such as LTPS (low temperature polysilicon). Even when manufacturing an electronic device that requires heat treatment at a high temperature, the polymer film with the electronic device can be easily peeled off from the inorganic substrate, which is effective for manufacturing a high-performance flexible display and various sensors.

Claims (8)

In a laminate in which an inorganic substrate and a polymer film are bonded via a silane coupling agent layer, the silane coupling agent layer is at least (3-aminopropyl) dimethylmethoxysilane, 3-aminopropyldimethoxymethylsilane, ( 3-Aminopropyl) dimethylethoxysilane or 3-aminopropyldiethoxymethylsilane, including
The polymer film is a polyimide film and is
A laminate characterized by containing 0.03 to 3% by mass of a lubricant in the polymer film. When the laminate is heat-treated at 200 ° C. for 1 hour, the 90-degree peel strength between the inorganic substrate and the polymer film is 0.05 N / cm or more and 20.0 N / cm or less, and the laminate is heated at 500 ° C. for 1 hour. The laminate according to claim 1, wherein the 90-degree peel strength between the inorganic substrate and the polymer film after heat treatment is 0.01 N / cm or more and 0.50 N / cm or less. The laminate according to claim 1 or 2, wherein the inorganic substrate is a kind selected from a glass plate, a ceramic plate, a silicon wafer, and a metal plate. The laminate according to any one of claims 1 to 3, wherein a polyimide film having a thickness of 1 to 100 μm is used as the polymer film. The invention according to any one of claims 1 to 4, wherein the polymer film is a polyimide film obtained by reacting an aromatic tetracarboxylic acid with an aromatic diamine having a benzoxazole structure (skeleton). Laminated body. A step of forming a layer containing the silane coupling agent layer according to claim 1 on at least one surface of the inorganic substrate.
A step of laminating a polymer film on a layer containing a silane coupling agent and forming a temporary laminate by applying pressure.
The step of heating the temporary laminate,
Including
A method for producing a laminate , wherein the polymer film is a polyimide film . A step of forming a layer containing the silane coupling agent layer according to claim 1 on at least one surface of the polymer film.
A step of laminating an inorganic substrate on the layer containing the silane coupling agent and forming a temporary laminate by applying pressure.
The step of heating the temporary laminate,
Including
A method for producing a laminate , wherein the polymer film is a polyimide film . The step of forming an electronic device on the polymer film surface of the laminate according to claim 6 or 7.
A method for manufacturing a flexible electronic device, which comprises a step of making a cut in the polymer film layer and peeling at least a part of the polymer film layer from the inorganic substrate together with the electronic device.