JP6067419B2 - Method for manufacturing laminated member - Google Patents

Description

  The present invention relates to a method for producing a laminated member, and more specifically, after a long base film is drawn out in the longitudinal direction to form a predetermined functional layer, a part of the base film is separated and removed to reduce the thickness. The present invention relates to a method for manufacturing a laminated member for obtaining a laminated member.

  For example, display devices such as a liquid crystal display device and an organic EL display device are used for various displays such as a large display such as a television and a small display such as a mobile phone, a personal computer, and a smartphone. Among these, for example, in an organic EL display device, a thin film transistor (hereinafter referred to as TFT) is formed on a glass substrate, an electrode, a light emitting layer, and an electrode are sequentially formed, and finally hermetically sealed with a glass substrate or a multilayer thin film. Made.

  In these display devices, by replacing the glass substrate with a resin substrate, it is possible to realize a thinner, lighter, and more flexible display than in the past, and the applications and variations of the display device can be further expanded. However, in general, resins are inferior in dimensional stability, transparency, heat resistance, moisture resistance, gas barrier properties, and the like as compared with glass, and various studies have been made to improve them.

  For example, Patent Document 1 proposes an invention related to a polyimide useful as a resin substrate for a flexible display and a precursor thereof, and includes a tetracyclic structure including an alicyclic structure such as cyclohexylphenyltetracarboxylic acid. It discloses that polyimides reacted with various diamines using carboxylic acids are excellent in transparency. Non-Patent Documents 1 and 2 propose organic EL display devices in which a highly transparent resin material is applied to a support substrate.

  On the other hand, by using a resin substrate having excellent flexibility, it is possible to make a roll-to-roll method. For example, Patent Document 2 discloses that in the manufacture of an organic EL display device, a roll-shaped film substrate having barrier layers on both sides of a transparent plastic substrate such as polycarbonate is used and conveyed in a roll-to-roll manner. Describes that an active layer of a thin film transistor is formed on a roll-shaped film substrate by a sputtering apparatus (see FIG. 6). By using such a long resin base material, continuous operation becomes possible, and an improvement in productivity of the display device can be expected.

JP 2008-231327 A JP 2011-181590 A

S. An et. al., “2.8-inch WQVGA Flexible AMOLED Using High Performance Low Temperature Polysilicon TFT on Plastic Substrates”, SID2010 DIGEST, p706 (2010) Oishi et. al., “Transparent PI for flexible display”, IDW’11 FLX2 / FMC4-1

  As described above, replacement of a glass substrate used in a display device or the like with a resin substrate (resin film) makes it possible to reduce the thickness, weight, and flexibility. In particular, mobile devices such as smartphones are highly competitive in the development of thinner and lighter devices, and the demand is extremely strong. However, in order to reduce the thickness of the resin substrate, it is necessary to fully consider handling properties. Especially when a long resin film is transported as in the roll-to-roll method, if the film is extremely thin, it is wound. The elongation becomes a problem at the time of removal, and in some cases, the film may be wrinkled or broken. Even if the film itself does not wrinkle or break, the various functional layers formed on the film, such as TFTs, electrodes, and light-emitting layers, may be affected by quality during the manufacturing process due to the expansion and contraction of the film. is there.

  Therefore, the present invention has been made in view of these problems. In obtaining a laminated member having a functional layer on a thin resin film, the quality of the functional layer is taken into consideration in the handling process in the manufacturing process. An object of the present invention is to provide a method capable of producing a laminated member while suppressing the influence on the surface.

  In order to solve the above-mentioned problems, the present inventors have intensively studied, and as a result, after forming a functional layer on the polyimide layer side using a base film provided with a polyimide layer on the support material, the polyimide layer and the support material By separating and removing the support material using the interface with the thin film, it is possible to function on the resin film consisting of the polyimide layer, suppressing the deterioration of handling in the manufacturing process and the effect on the quality of the functional layer. The present inventors have found that a laminated member having a layer can be obtained and completed the present invention.

That is, the present invention is to roll out a long base film wound up in a roll shape in the longitudinal direction by a roll-to-roll method , perform a film forming process, and perform a patterning process as necessary. a laminated by forming a functional layer member a continuous process for producing the substrate film, which comprises a polyimide layer having a polyamic acid solution was applied by imidization on the support member, the After the functional layer is formed on the polyimide layer side, the support material is separated and removed using the interface between the polyimide layer and the support material, and the base material film is thinned. .

  In the present invention, a long base film wound up in a roll shape is stretched in the longitudinal direction to form a film, and if necessary, the film is patterned to function on the base film. After the layer is formed, a part of the base film is separated and removed, and thinned to obtain a laminated member having a functional layer on a thin resin film (polyimide layer).

  In general, when adopting a roll-to-roll method, a long resin film wound up by a feed-side roll winding mechanism is transported in a roll while being fed out in a longitudinal direction by a delivery mechanism, to form a film, etc. The process is performed, and the film is wound by the roll-winding mechanism on the winding side via the winding mechanism.

  Here, in Patent Document 2, it is assumed that a transparent plastic film such as a polysulfone resin, an olefin resin, a cyclic polyolefin resin, or the like can be used as the long resin film in addition to the polycarbonate, and the thickness thereof is 50. It is assumed that the thickness is about 200 μm (see paragraph 0083). However, since the tensile stress is applied at least when the resin film is wound up by the roll-side roll winding mechanism, naturally, elongation and shrinkage become a problem when the thickness of the resin film is reduced. Therefore, if it does not have a thickness of at least about 100 μm, in actuality, defects such as wrinkles or tearing of the film occur when winding with the roll winding mechanism. In addition, multiple layers may be formed to form a functional layer, or the formed metal may be subjected to patterning while the resin film once wound up is rolled out again by a roll-to-roll method. In a case where a plurality of processes are performed, if there is expansion and contraction of the film, the dimensional accuracy is not maintained, and the quality of the obtained functional layer may be affected.

  Therefore, in the present invention, a base film having a polyimide layer imidized by applying a polyamic acid solution on a support material is used, and at least a functional layer is formed by a roll-to-roll method or the like. The mechanical strength is ensured by the thickness of the base film, and after the functional layer is formed, the support material is separated and removed using the interface between the polyimide layer and the support material. A laminated member having a functional layer on a thin resin film is obtained. In addition, the manufacturing method of the laminated member in the present invention can be applied to a roll-to-roll method including a roll-side roll winding mechanism and a roll-side roll winding mechanism. It can also be applied to an incomplete roll-to-roll system that cuts the substrate film rolled by the take-up mechanism in front of the mechanism into a sheet, and tension is applied to the film in any situation This is particularly effective in such cases.

  In the present invention, the interface between the polyimide layer and the support material is easily separated by using the interface between the polyimide layer and the support material so that the base film can be thinned. It needs to be in a state. As the means, it is preferable to use a polyimide having a specific chemical structure at the interface between the polyimide layer and the support material.

式中、Ａｒ₁は酸無水物残基である４価の有機基を表し、Ａｒ₂はジアミン残基である２価の有機基であり、耐熱性の観点から、Ａｒ₁、Ａｒ₂の少なくとも一方は、芳香族残基であるのが望ましい。 Generally, a polyimide is obtained by polymerizing a raw acid anhydride and a diamine, and can be represented by the following general formula (1).

In the formula, Ar ₁ represents a tetravalent organic group which is an acid anhydride residue, Ar ₂ is a divalent organic group which is a diamine residue, and from the viewpoint of heat resistance, Ar ₁ and Ar ₂ are at least One is preferably an aromatic residue.

このような繰返し構造単位のうち、更に好ましくは、下記繰り返し構造単位（ｂ）を有するポリイミドである。

As a polyimide (polyimide resin) suitably used in the present invention, a polyimide having the following repeating structural unit (a) can be given as a first example. More preferably, the following repeating unit is contained in a proportion of 80 mol% or more.

Among such repeating structural units, a polyimide having the following repeating structural unit (b) is more preferable.

  If it is a polyimide which has a repeating structural unit (a) or (b) like this 1st example, since a glass transition temperature (Tg) can form a heat resistant polyimide surface with 300 degreeC or more, a polyimide layer Is formed by such a polyimide, or the surface of the support material has a heat-resistant polyimide surface made of such a polyimide, so that separation at the interface between the polyimide layer and the support material is performed. Can be made easier.

  Here, when the polyimide shown as the first example is used, other polyimides that may be added in a proportion of less than 20 mol% at the maximum other than the polyimide are not particularly limited and will be described later. Such general acid anhydrides and diamines can be used.

Moreover, fluorine-containing polyimide is mentioned as a 2nd example of the polyimide (polyimide resin) used suitably. That is, the polyimide layer is formed of such a polyimide, or the surface of the support material has a heat-resistant polyimide surface made of such a polyimide, so that the polyimide layer and the support material Separation at the interface can be facilitated. Here, the fluorine-containing polyimide means one having a fluorine atom in the polyimide structure, and has a fluorine-containing group in at least one component of an acid anhydride and a diamine which are polyimide raw materials. As such a fluorine-containing polyimide, for example, among those represented by the general formula (1), Ar _{1 in} the formula is a tetravalent organic group, and Ar ₂ is represented by the following general formula (2) or (3 What is represented by a divalent organic group represented by

R _{1 to} R ₈ in the general formula (2) or the general formula (3) are each independently a hydrogen atom, a fluorine atom, an alkyl group or an alkoxy group having 1 to 5 carbon atoms, or a fluorine-substituted hydrocarbon group. In the general formula (2), at least one of R _{1 to} R ₄ is a fluorine atom or a fluorine-substituted hydrocarbon group, and in the general formula (3), R _{1 to} R _8. At least one of them is a fluorine atom or a fluorine-substituted hydrocarbon group. Among these, preferred specific examples of R _{1 to} R ₈ include —H, —CH ₃ , —OCH ₃ , —F, —CF _{3, and the} like. At least in Formula (2) or Formula (3), One substituent is preferably either —F or —CF ₃ .

Specific examples of Ar ₁ in the general formula (1) when forming the fluorine-containing polyimide include, for example, the following tetravalent acid anhydride residues.

The fluorine-containing polyimide as described above includes those having excellent transparency. For example, display devices such as liquid crystal display devices and organic EL display devices are used, and laminated members that require transparency are obtained. In this case, it is suitable for forming the polyimide layer, but if it is considered to make its transparency more excellent or to improve the peelability at the interface between the polyimide layer and the support material, As specific diamine residues that give Ar ₂ in the general formula (1), the following are preferably used.

Further, in such a fluorine-containing polyimide, when any one of the structural units represented by the following general formula (4) or (5) is contained in a proportion of 80 mol% or more, transparency and releasability are obtained. In addition, the thermal expansion property is low and the dimensional stability is excellent. That is, if the polyimide has a structural unit represented by the following general formula (4) or (5), the transmittance in the wavelength region from 440 nm to 780 nm is 70% or more, preferably 80% or more. It is more advantageous for forming a polyimide layer in a laminated member that requires transparency, such as a display device. Further, it has a glass transition temperature (Tg) of 300 ° C. or higher, and the thermal expansion coefficient can be 25 ppm / K or less, preferably 10 ppm / K or less. Therefore, by using such a polyimide in both the polyimide layer and the support material, even when subjected to a temperature change during the process, the thermal expansion coefficient of both of them is close, so that warpage or wrinkles can be prevented. .

  Here, when the polyimide is a polyimide according to the structure of the general formula (4) or (5), other polyimides that may be added at a ratio of less than 20 mol% at the maximum other than the polyimide are particularly limited. In general, general acid anhydrides and diamines can be used. Among these, acid anhydrides preferably used include pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 1,4-cyclohexanedicarboxylic acid, 1,2,3 , 4-cyclobutanetetracarboxylic dianhydride, 2,2′-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, and the like. On the other hand, diamines include 4,4'-diaminodiphenylsulfone, trans-1,4-diaminocyclohexane, 4,4'-diaminocyclohexylmethane, 2,2'-bis (4-aminocyclohexyl) -hexafluoro. Examples include propane and 2,2′-bis (trifluoromethyl) -4,4′-diaminobicyclohexane.

  Various polyimides including the first and second examples can be obtained by imidizing polyamic acid. Here, the polyamic acid resin solution is preferably obtained by using substantially equal moles of diamine and acid dianhydride as raw materials and reacting them in an organic solvent. More specifically, it is obtained by dissolving diamine in an organic polar solvent such as N, N-dimethylacetamide under a nitrogen stream, adding tetracarboxylic dianhydride, and reacting at room temperature for about 5 hours. Can do. The weight average molecular weight of the obtained polyamic acid is preferably 10,000 to 300,000 from the viewpoint of uniform film thickness during coating and mechanical strength of the resulting polyimide film. In addition, the preferable molecular weight range of the polyimide layer obtained is also the same molecular weight range as this polyamic acid. Moreover, the polyimide layer may be formed of a single layer or may be formed of a plurality of layers. In the case of being formed from a plurality of layers, at least the layer forming the interface with the support material may be made of polyimide as exemplified in the first and second examples.

  And in order to obtain the base film which has a polyimide layer on a support material, after apply | coating a polyamic acid solution to a support material, it heat-processes at about 150-160 degreeC, for example, and the solvent contained in a resin solution is used. The polyamic acid is imidized by removing and further heat-treating at a high temperature. The heat treatment performed at the time of imidation may be performed continuously or stepwise from a temperature of about 160 ° C. to a temperature of about 350 ° C., for example. At this time, it is preferable to use a casting method in which a long support material is prepared, and a polyamic acid resin solution for forming a polyimide layer is applied while being conveyed by a roll-to-roll method. .

  The support material for forming the base film in the present invention has flexibility and at least heat resistance that can withstand heat treatment when forming a polyimide layer by applying a polyamic acid solution and imidizing it. I just need it. Specifically, metal foils such as copper foil and SUS foil, metal foil-resin laminates such as copper clad laminate (CCL), resin films such as polyimide, and the like. Among these, as described above, in order to have the surface of the support material have a heat-resistant polyimide surface made of polyimide as mentioned in the first and second examples, the metal foil-polyimide provided with these polyimides A support material such as a laminate may be used, or a polyimide film made of these polyimides may be used alone as a support material. Moreover, in order to make the separation at the interface between the polyimide layer and the support material the easiest, the interface between the polyimide layer and the support material should be formed of the polyimides mentioned in the first and second examples. .

  Further, for the support material in the present invention, from the viewpoint of facilitating separation at the interface between the polyimide layer and the support material, the surface of the support material at the interface between the polyimide layer and the support material is preferably surface roughness Ra. Is preferably 100 nm or less. Furthermore, when the support material has electrical conductivity, or has an electrical conductive layer on the back side opposite to the polyimide layer, when the film is unwound and rolled up like a roll-to-roll system, There is an advantage that charging due to generated static electricity can be prevented.

  In the present invention, by using the polyimide exemplified above, the adhesive strength at the interface between the polyimide layer and the support material is preferably 1 N / m or more and 500 N / m or less, more preferably 5 N / m or more. It can be 300 N / m or less, more preferably 10 N / m or more and 200 N / m or less. For example, it can be easily peeled off by human hands.

  In the present invention, as described above, since the thickness of the base film is ensured by the presence of the support material, the mechanical strength when forming the functional layer is maintained even if the thickness of the polyimide layer is reduced. When the film is fed out and wound up as in the roll-to-roll system, the tensile stress is applied to the film by the roll of the feeding mechanism or the winding mechanism, and further by the roll winding mechanism on the winding side. In general, a film thickness of about 100 [mu] m is required for this, but in the present invention, it is sufficient that the film thickness reaches at least that of the support material. Therefore, the thickness of the polyimide layer can be 100 μm or less, preferably 50 μm or less, and more preferably 30 μm or less. Note that the lower limit of the thickness of the polyimide layer is preferably 2 μm, and preferably 5 μm, in view of ensuring insulation in the laminated member including the functional layer.

  On the other hand, about the thickness of a support material, what is necessary is just to be able to maintain thickness required as a base film including a polyimide layer, and can be set arbitrarily. That is, considering the role as a support material, winding property, and the like, for example, a thickness of 10 to 200 μm can be exemplified, but there is no particular limitation. However, it is desirable that the polyimide layer be thinner than the support material.

  The laminated member in the present invention can be used as a display device such as a liquid crystal display device or an organic EL display device, an electronic paper, a touch panel or the like, or a component thereof, and is used in an organic EL lighting device or laminated with ITO or the like. It is used as a functional material having various functions such as a conductive film, a gas barrier film that prevents permeation of moisture, oxygen, and the like, and a component part of a flexible circuit board. That is, the functional layer referred to in the present invention constitutes various functional materials including these display devices, lighting devices, or components thereof, and specifically includes an electrode layer, a light emitting layer, and a gas barrier layer. , An adhesive layer, a thin film transistor, a wiring layer, a transparent conductive layer, and the like are collectively referred to as one or a combination of two or more.

  These functional layers can be obtained by using a known method such as forming a metal or the like, then patterning the metal into a predetermined shape as necessary, or performing a heat treatment. That is, the means for forming these functional layers is not particularly limited, and is appropriately selected, for example, sputtering, vapor deposition, CVD, printing, exposure, immersion, etc., and if necessary, in a vacuum chamber, etc. These process processes may be performed. Then, the support material may be separated and removed immediately after the functional layer is formed through various process treatments. The support material may be integrated with the support material for a certain period of time, for example, as a display device or a functional material. You may make it remove | separate and remove immediately before doing.

  According to the present invention, after obtaining a laminated member having a functional layer on a thin resin film, mechanical strength is ensured by the thickness of the base film at least during the formation of the functional layer, and after the functional layer is formed. Is a problem with a laminated member equipped with a functional layer on a thin resin film consisting of a polyimide layer by separating and removing the support material by utilizing the interface between the polyimide layer and the support material in the base film and making it thin. And can be manufactured efficiently.

  Moreover, since the laminated member obtained by the present invention can reduce the thickness of the resin film, it is suitably used for a display device, various functional materials, and the like, and further realizes a reduction in thickness, weight, and flexibility. be able to.

FIG. 1 is a schematic view showing a roll-to-roll apparatus for forming a functional layer on a long base film. FIG. 2 is a schematic view showing a long roll-shaped base film. FIG. 3 shows a schematic cross-sectional view of the base film. FIG. 4 shows a schematic cross-sectional view after the functional layer is formed on the base film. FIG. 5 is a schematic diagram showing how the support material is separated and removed from the base film.

  Hereinafter, the present invention will be specifically described with reference to the drawings. The present invention is not limited to these contents.

  FIG. 1 shows a state in which a functional layer is formed on a base film by a roll-to-roll method. In this roll-to-roll apparatus, a long base film 10 taken up by a delivery-side roll winding mechanism 14 is fed out in a longitudinal direction by a delivery mechanism 12 and is processed by a process processing unit 11 such as a sputtering apparatus. A functional layer is formed by depositing a predetermined metal, and the film is wound by the roll winding mechanism 15 on the winding side via the winding mechanism 13. Here, when a vacuum environment is required for the process, the entire roll-to-roll apparatus is installed in a vacuum chamber.

  Moreover, the long roll-shaped base film 10 is shown by FIG. As shown in the longitudinal sectional views of FIGS. 3 to 5, the base film 10 includes a polyimide layer 2 that is imidized by applying a polyamic acid solution on a support material 1. After the functional layer 3 is formed on the surface 2, the support material 1 can be separated using the interface between the polyimide layer 2 and the support material 1, removed, and thinned.

  About the functional layer formed on the base film 10, it can select suitably according to the use of the laminated member 20 obtained by this invention, For example, an electrode layer, a light emitting layer, a gas barrier layer, an adhesive layer, a thin-film transistor, a wiring layer Examples thereof include a combination of one or more transparent conductive layers and the like. Hereinafter, specific examples for obtaining a functional layer will be described in accordance with uses of some laminated members.

(Manufacture of transparent conductive film)
A transparent conductive film can be obtained by laminating a transparent conductive layer on a long roll-shaped substrate film 10 provided with a polyimide layer 2 on a support material 1. That is, in this case, the transparent conductive layer corresponds to the functional layer 3. In obtaining a transparent conductive film, for example, a polyimide made of polyimide having one of the structural units represented by the general formula (4) or (5) shown in the second example in a proportion of 80 mol% or more. A long transparent substrate film 10 wound in a roll shape is prepared so that the film is a support material 1 and the polyimide layer 2 is formed of the same polyimide. Here, the polyimide film of the support material 1 may be a polyimide having the structural unit (a) shown in the first example.

  The transparent base film 10 is set in a roll-to-roll apparatus as shown in FIG. As shown in FIG. 1, the transparent base film 10 is held by the roll-side roll mechanism 14, the feed mechanism 12, the wind-up mechanism 13, and the roll-side roll mechanism 15, and is fed out in the longitudinal direction. A transparent conductive layer is laminated on the surface of the polyimide layer 2 of the transparent base film 10 by means such as a vapor deposition method in the process processing unit 11. At that time, if a vacuum environment is required for laminating the transparent conductive layer, the entire roll-to-roll apparatus may be installed in a vacuum chamber to perform the process.

  Here, when the polyimide layer 2 is formed of polyimide having one of the structural units represented by the general formula (4) or (5) at a ratio of 80 mol% or more, it is visible while being low in thermal expansion. High transmittance in the light region and excellent transparency. Further, it has excellent dimensional stability, high heat resistance, good surface smoothness, and small retardation in the in-plane direction. Moreover, by using a polyimide film made of the same polyimide for the support material 1, the polyimide layer 2 formed by the casting method and the support body 1 are integrated with a certain degree of adhesive force, and roll-to-roll. A transparent conductive layer can be formed by an apparatus, and after the transparent conductive layer is formed, it can be easily separated and thinned using the interface between the support material 1 and the polyimide layer 2.

  By the way, when ITO is used as the transparent conductive layer, it is in an amorphous state when deposited on the base film 10 and has a high resistance value. For example, when applying a transparent conductive film to a touch panel, resistance reduction is required. Therefore, after patterning the electrode pattern for the touch panel, an annealing process of about 200 ° C. to 300 ° C. is performed so as to lower the resistance value. It has sufficient heat resistance with respect to an appropriate annealing temperature, and a sufficiently low resistance can be achieved by annealing treatment.

  In consideration of providing the transparent conductive film to a touch panel or the like, the thickness should be as thin as possible. For example, when a film having a thickness of 50 μm is applied alone to a roll-to-roll apparatus, difficulty in handling and elongation of the film during the conveyance process become problems. However, if the base film 10 as in the present embodiment is used, for example, if the thickness of the support material 1 and the polyimide layer 2 is 50 μm, respectively, while solving these problems, a transparent conductive film having a thickness of approximately 50 μm ( The transparent conductive layer has a thickness of about 100 nm) and can be produced industrially with high productivity.

(Manufacture of gas barrier film)
For example, when moisture or oxygen enters the organic EL light-emitting layer of the organic EL device, the characteristics are deteriorated. Therefore, a gas barrier layer for preventing the penetration of moisture and oxygen is indispensable. Therefore, in the process processing unit 11, an inorganic oxide film such as silicon oxide, aluminum oxide, silicon carbide, silicon oxycarbide, silicon carbonitride, silicon nitride, or silicon nitride oxide is formed as a functional layer by, for example, the CVD method. Other than that, a thin gas barrier film can be obtained in the same manner as in the case of the transparent conductive film.

  By the way, if the difference between the coefficient of thermal expansion (CTE) of the gas barrier layer made of the inorganic oxide film and the CTE of the polyimide film made of the polyimide layer 2 becomes large, curling occurs and dimensional stability is increased. There is a risk that it will deteriorate or cracks may occur in some cases. In particular, when a large area film is manufactured, the problem of warpage becomes more prominent. However, if the polyimide layer 2 is formed of polyimide having one of the structural units represented by the general formula (4) or (5) at a ratio of 80 mol% or more, the CTE is preferably 15 ppm / K or less. In general, the difference from the inorganic oxide film having a CTE of 10 ppm / K or less can be reduced, so that such problems are eliminated. The gas barrier layer may be formed from one kind of the inorganic film as described above, or may be formed so as to include two or more kinds.

(Manufacture of thin film transistors)
First, thin film transistors (TFTs) are roughly classified into amorphous silicon TFTs (a-Si TFTs) and polysilicon TFTs. In polysilicon TFTs, low-temperature polysilicon TFTs (LTPS-TFTs) that can lower the process temperature are used. It has become mainstream. Hereinafter, a method of obtaining a bottom gate structure a-Si TFT will be described in obtaining a thin film transistor (TFT) used for a backplane or the like of a liquid crystal display device.

  In advance, in order to prevent the entry of oxygen, water vapor, and the like from the outside, the base film 10 is provided with a gas barrier layer in the same manner as the above-described method for manufacturing a gas barrier film. Next, a material for forming the gate electrode and the wiring is formed. Al-based material is mainly used as the film forming material, and is laminated by means such as sputtering. After film formation, the gate and wiring patterns are transferred in a photolithography process, and formed into a predetermined shape (patterning) by etching.

Next, a gate insulating film (SiN, SiO ₂ or the like) and a semiconductor layer (a-Si) are similarly formed by a method such as CVD and formed into a predetermined shape. Thereafter, processing processes such as a film forming process, a photolithography process, and an etching process are similarly repeated to form drain wirings, source electrodes, an interlayer insulating film, and the like, and an a-Si TFT can be obtained. In order to obtain the a-Si TFT as described above, the base film 10 may be continuously processed with the process processing units 11 for various process processes arranged side by side, or once. The wound resin film may be fed out again by a roll-to-roll method so that the process is divided into several steps.

(Manufacture of organic EL display devices)
For example, in order to obtain an organic EL display device having a bottom emission structure, first, a gas barrier layer is provided on the polyimide layer 2 side of the base film 10 in the same manner as described above, and moisture and oxygen are permeable to moisture. Make the structure to prevent. Next, a circuit constituent layer including the above-described thin film transistor (TFT) is formed on the upper surface of the gas barrier layer. In this case, LTPS-TFT is mainly selected as the thin film transistor. In this circuit configuration layer, an anode electrode made of, for example, an ITO transparent conductive film is formed on each of the pixel regions arranged in a matrix on the upper surface thereof. Further, an organic EL light emitting layer is formed on the upper surface of the anode electrode, and a cathode electrode is formed on the upper surface of the light emitting layer. This cathode electrode is formed in common in each pixel region. Then, a gas barrier layer is formed again so as to cover the surface of the cathode electrode, and a sealing substrate is installed on the outermost surface for surface protection. It is desirable to laminate a gas barrier layer that prevents moisture and oxygen from permeating through the surface of the sealing substrate on the cathode electrode side.

  As described above, in the organic EL display device, various thin films are generally formed on the polyimide layer 2 of the base film 10 in the above order, and finally sealed with a sealing substrate. The organic EL light-emitting layer is formed of a multilayer film (anode electrode-light-emitting layer-cathode electrode) such as a hole injection layer-hole transport layer-light-emitting layer-electron transport layer. Since it deteriorates due to moisture and oxygen, it is generally formed by vacuum deposition, and it is generally formed continuously in vacuum including electrode formation.

(Manufacture of organic EL lighting devices)
In obtaining organic EL illumination, the functional layer generally has a bottom emission structure excluding the TFT layer in the organic EL display device described above. Here, a transparent electrode such as ITO is generally used as the anode electrode, and the electrode resistance decreases as the temperature is increased. As described above, in the case of ITO, heat treatment at about 200 to 300 ° C. is common. Note that organic EL illumination is in the direction of increasing size, and ITO electrodes are becoming insufficient in resistance, and various alternative electrode materials are being searched for. In that case, the annealing temperature is likely to be higher than 200 to 300 ° C. However, since the base film using polyimide as described above has sufficient heat resistance, various alternative electrodes can be used. It can also handle materials.

(Manufacture of other functional layers)
In addition to the above examples, for example, various functional layers necessary for obtaining electronic paper, a touch panel, and the like are formed on the base film 10 and then supported using the interface between the polyimide layer 2 and the support material 1. If the material 1 is separated and removed to obtain a thin laminated member, it can be made thinner and lighter than conventional ones.

The present invention will be described below based on test examples.
First, the abbreviations of raw material monomers and solvents used in the synthesis of polyimide and the measurement methods and conditions for various physical properties in the examples are shown below.

[About abbreviations]
DMAc: N, N-dimethylacetamide PDA: 1,4-phenylenediamine TFMB: 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl DADMB: 4,4′-diamino- 2,2′-dimethylbiphenyl, 1,3-BAB: 1,3-bis (4-aminophenoxy) benzene, BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 6FDA: 2 , 2'-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride-PMDA: pyromellitic dianhydride

[Surface roughness (Ra)]
Surface observation was performed in a tapping mode using an atomic force microscope (AFM) “Multi Mode 8” manufactured by Bruker. Observation of a 10 μm square field of view was performed four times, and the average value thereof was obtained. The surface roughness (Ra) represents the arithmetic average roughness (JIS B0601-1991).

[Peel strength]
Using Toyo Seiki Seisakusho's Strograph R-1 to measure the peel strength by the T-peeling test method for the interface between the support and the polyimide layer in the sample obtained by cutting the polyimide laminate into a strip with a width of 10 mm. It was evaluated by.

[Transmissivity (%)]
About the polyimide film (50 mm x 50 mm) which consists of a polyimide layer for forming a functional layer, the average value of the light transmittance in 440 nm to 780 nm was calculated | required using the U4000 type spectrophotometer.

[Glass transition temperature Tg]
The glass transition temperature of a polyimide film composed of a polyimide layer for forming a functional layer was measured as follows. Using a viscoelasticity analyzer (RSA-II, manufactured by Rheometric Science Effy Co., Ltd.), using a sample with a width of 10 mm and applying a 1 Hz vibration while raising the temperature from room temperature to 400 ° C. at a rate of 10 ° C./min. Of the loss tangent (Tan δ).

[Coefficient of thermal expansion (CTE)]
For polyimide film and support material consisting of polyimide layer to form functional layer, each sample of 3mm x 15mm was cut out, and constant temperature increase rate (5.0g load was applied with thermomechanical analysis (TMA) device) A tensile test was performed at a temperature range of 30 ° C. to 260 ° C. at 20 ° C./min), and the thermal expansion coefficient (× 10 ⁻⁶ / K) was measured from the amount of elongation of the sample with respect to the temperature.

Synthesis Example 1 (Polyimide A)
Under a nitrogen stream, 8.00 g of PDA was dissolved in the solvent DMAc while stirring in a 300 ml separable flask. Then 22.00 g of this solution BPDA was added. Thereafter, the solution was stirred at room temperature for 5 hours to conduct a polymerization reaction, and kept for a whole day and night. A viscous polyamic acid solution was obtained, and it was confirmed that polyamic acid A having a high polymerization degree was produced.

Synthesis Example 2 (Polyimide B)
Under a nitrogen stream, 12.08 g of TFMB was dissolved in the solvent DMAc while stirring in a 300 ml separable flask. Next, 6.20 g of PMDA and 4.21 g of 6FDA were added to this solution. Thereafter, the solution was stirred at room temperature for 5 hours to conduct a polymerization reaction, and kept for a whole day and night. A viscous polyamic acid solution was obtained, and it was confirmed that polyamic acid B having a high polymerization degree was produced.

Synthesis Example 3 (Polyimide C)
Under a nitrogen stream, 13.30 g of TFMB was dissolved in the solvent DMAc while stirring in a 300 ml separable flask. Next, 9.20 g of PMDA was added to this solution. Thereafter, the solution was stirred at room temperature for 5 hours to conduct a polymerization reaction, and kept for a whole day and night. A viscous polyamic acid solution was obtained, and it was confirmed that polyamic acid C having a high polymerization degree was produced.

Example 1 [Production of Laminated Member I]
After applying the polyamic acid A resin solution obtained in Synthesis Example 1 onto a long electrolytic copper foil having a thickness of 18 μm, the solvent was removed by heating at 130 ° C. Next, a copper-clad laminate having a polyimide (surface roughness Ra = 1.3 nm, Tg = 355 ° C.) having a thickness of 25 μm imidized by heat treatment from 160 ° C. to 360 ° C. at a heating rate of about 4 ° C./min. (Coefficient of thermal expansion 17.5 ppm / K) was obtained and used as a support material.

  After uniformly applying the polyamic acid B resin solution obtained in Synthesis Example 2 to the polyimide surface of the obtained copper-clad laminate so that the thickness after curing is 25 μm, it is dried by heating at 130 ° C., The solvent in the resin solution was removed. Next, a long base film provided with a polyimide layer for imidizing polyamic acid by heat treatment at a temperature increase rate of about 20 ° C./min from 160 ° C. to 360 ° C. to form a functional layer I was obtained.

  The long base film I obtained above is mounted on a test machine simulating the roll-to-roll apparatus shown in FIG. 1, and the long base film I wound up in a roll shape is sent out. Rolled out from the roll in the longitudinal direction, introduced into a process processing section installed in a vacuum chamber via a transport roll, and 100 nm thick by sputtering on the polyimide layer of the long base film I in the process processing section. ITO was formed into a film by continuous treatment. Next, after cutting out to a predetermined length, annealing treatment was performed at 250 ° C. to crystallize the ITO film, and the test piece according to Example 1 was completed.

  About the test piece obtained above, while measuring the peel strength at the interface between the copper clad laminate as a support material and the polyimide layer, the support material was separated and removed, and from the ITO on the polyimide layer having a thickness of 25 μm A laminated member I having a transparent conductive layer formed was obtained. The peel strength at that time was 8.7 N / m, which was a value that could be easily peeled by a human hand. Table 1 summarizes the transmittance and thermal expansion coefficient of the polyimide layer in the base film I used for obtaining the laminated member I.

Example 2 [Production of Laminated Member II]
A long polyimide film (Kapton H, manufactured by Toray DuPont Co., Ltd .: surface roughness Ra = 70 nm, Tg = 428 ° C., thermal expansion coefficient 28.5 ppm / K) is used as a support material. The resin solution of polyamic acid B obtained in Synthesis Example 2 was uniformly applied so that the thickness after curing was 25 μm, and then heated and dried at 130 ° C. to remove the solvent in the resin solution. Next, heat treatment is performed at a temperature increase rate of about 20 ° C./min from 160 ° C. to 360 ° C. to imidize polyamic acid to form a polyimide layer, and a long shape having a polyimide layer on a support material (polyimide film) Base film II was obtained.

  Using the obtained base film II, an ITO film was formed in the same manner as in Example 1 and annealed to complete the test piece according to Example 2. The peel strength at the interface between the support material (polyimide film) and the polyimide layer in this test piece was 130 N / m, which was a value that could be easily peeled by human hands. Moreover, the transmittance | permeability and thermal expansion coefficient are collectively shown in Table 1 about the polyimide layer in the base film II used in obtaining this laminated member II.

Example 3 [Production of Laminated Member III]
A long polyimide film (upilex S, manufactured by Ube Industries, Ltd .: surface roughness Ra = 15 nm, Tg = 359 ° C., thermal expansion coefficient 12.5 ppm / K) is used as a support material. A long base film III was obtained in the same manner as in Example 2 except that the polyamic acid C resin solution obtained in Synthesis Example 3 was uniformly applied so that the thickness after curing was 25 μm.

  Using the obtained base film III, an ITO film was formed in the same manner as in Example 1, and annealed to complete the test piece according to Example 3. The peel strength at the interface between the support material (polyimide film) and the polyimide layer in this test piece was 53 N / m, which was a value that could be easily peeled by human hands. Table 1 shows the transmittance and the thermal expansion coefficient of the polyimide layer in the base film III used for obtaining the laminated member III.

DESCRIPTION OF SYMBOLS 1 Support material 2 Polyimide layer 3 Functional layer 10 Base film 11 Process processing part 12 Delivery mechanism 13 Winding mechanism 14 Rolling mechanism on delivery side 15 Roll winding mechanism on winding side 20 Laminating member

Claims (13)

A long base film wound up in a roll shape is fed out in the longitudinal direction by a roll-to-roll method to form a film, and if necessary, patterned to form a functional layer on the base film. A method of continuously producing laminated members,
The base film is provided with a polyimide layer imidized by applying a polyamic acid solution on a support material, and after forming a functional layer on the polyimide layer side, an interface between the polyimide layer and the support material is formed. A method for producing a laminated member, characterized in that the support material is separated and removed by use to thin the substrate film.   The method for producing a laminated member according to claim 1, wherein the polyimide layer is composed of a single layer or a plurality of layers, and at least an interface with the support material is formed of fluorine-containing polyimide. The said polyimide layer is a manufacturing method of the laminated member of Claim 1 or 2 formed with a polyimide whose glass transition temperature is 300 degreeC or more. The manufacturing method of the laminated member in any one of Claims 1-3 in which the said polyimide layer is formed with the polyimide which has the following structural unit.

The polyimide layer, method for manufacturing a laminated member according to any one of claims 1 to 4 transmittance at 780nm wavelength range is 70% or more from 440 nm. Surface of the support at the interface between the support and the polyimide layer, method for manufacturing a laminated member according to any one of claims 1 to 5 surface roughness Ra of 100nm or less. The surface of the support at the interface between the polyimide layer and the support material, method for manufacturing a laminated member according to any one of claims 1 to 6, the glass transition temperature is formed by the 300 ° C. or more heat-resistant polyimide surface. The said heat resistant polyimide surface is a manufacturing method of the laminated member in any one of Claims 1-7 currently formed from the polyimide which has the following structural unit.

Method for manufacturing a laminated member according to any one of claims 1-8 bond strength at the interface is less than 1N / m or more 500 N / m between the support member and the polyimide layer. The thermal expansion coefficient of the polyimide layer is not more than 25 ppm / K, A method for manufacturing a laminated member according to any one of claims 1-9 thermal expansion coefficient of the support material is not more than 25 ppm / K. With the thickness of the polyimide layer is 2 to 100 m, the a thickness of the support is 10 to 200 [mu] m, and the thickness of the polyimide layer can be of any claim 1-10 wherein at thinner than the support member The manufacturing method of the laminated member of crab. The method for producing a laminated member according to any one of claims 1 to 11 , wherein the support material has electrical conductivity or has an electrical conductive layer on the back side opposite to the polyimide layer. The functional layer is a layer including any one type or a combination of two or more types selected from the group consisting of an electrode layer, a light emitting layer, a gas barrier layer, an adhesive layer, a thin film transistor, a wiring layer, and a transparent conductive layer. method for manufacturing a laminated member according to any one of 1-12.

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