CN104685553B - The manufacture method of display device - Google Patents

Abstract

An object of the present invention is to provide a method for manufacturing a display device that can easily separate the resin substrate from the support after forming a predetermined display portion on the resin substrate integrated with the support beforehand, and obtain the display device simply. The method for manufacturing a display device is characterized in that in a state where the first resin layer (7) and the second resin layer (8) are stacked on the support body (1), a predetermined display portion is formed on the second resin layer (4) Thereafter, separation is performed at the interface between the first resin layer and the second resin layer to obtain a display device including a display portion on a resin base material composed of the second resin layer.

Description

Manufacturing method of display device

technical field

The present invention relates to a method for manufacturing a display device. Specifically, it relates to a method for manufacturing a display device in which a display portion of a liquid crystal display device, an organic EL display device, or the like is formed on a resin base material.

Background technique

Display devices such as liquid crystal display devices and organic EL display devices are used in various display applications such as large displays such as televisions and small displays such as mobile phones, personal computers, and smartphones. As a representative of the display device, there is an organic EL display device. For example, the organic EL display device is produced by forming a thin film transistor (hereinafter, TFT) on a glass substrate as a supporting base material, and sequentially forming an electrode, a light emitting layer, and an electrode. , and finally hermetically sealed with another glass substrate, multi-layer film, etc.

Here, by changing the glass substrate as the support base from the conventional glass substrate to a resin base, thinner, lighter, and more flexible displays can be achieved, and the applications of display devices can be further expanded. However, resins are generally inferior in dimensional stability, transparency, heat resistance, moisture resistance, gas barrier properties, etc. compared to glass, so they are currently in the research stage and various studies are being carried out.

For example, Patent Document 1 relates to the invention of polyimide useful as a plastic substrate for flexible displays and its precursor, and reports the use of tetracarboxylic acids containing an alicyclic structure such as cyclohexylphenyl tetracarboxylic acid and the like. Polyimides obtained by reacting various diamines are excellent in transparency. In addition, attempts have been made to reduce weight by using flexible resins as supporting substrates. For example, the following Non-Patent Documents 1 and 2 propose organic EL displays using highly transparent polyimides as supporting substrates. device.

Thus, it has been found that resin films such as polyimide are useful for plastic substrates for flexible displays, but the manufacturing process of display devices is already performed using glass substrates, and most of the production equipment is designed on the premise of using glass substrates. Therefore, it is desired to be able to produce display devices while effectively utilizing existing production facilities.

As a specific example of this research, there is known a manufacturing method in which a predetermined display device manufacturing process is completed in a state where a resin film is laminated on a glass substrate, and then the glass substrate is removed, thereby manufacturing a display device on a resin substrate. A display device including a display unit (see Patent Document 2, Non-Patent Document 3, and Non-Patent Document 4). Furthermore, in these cases, it is necessary to separate the resin base material and glass without damaging the display part (display part) formed on the resin base material.

That is, in Non-Patent Document 3, a method called EPLaR (Electronics on Plastic by Laser Release) process is used after forming a predetermined display portion on a resin substrate coated on a glass substrate and fixed. Laser light is irradiated from the glass side to forcibly separate the resin substrate including the display part from the glass. However, this method not only requires an expensive laser device, but also has a disadvantage of low productivity because it takes time for separation. In addition, there is a possibility of adverse effects on the surface properties of the resin substrate and the display unit mounted thereon at the time of separation.

On the other hand, the method described in Non-Patent Document 4 is a method for improving the disadvantages of the EPLaR method. The method is as follows: after coating a release layer on a glass substrate, a polyimide resin is coated on the release layer, and organic After the manufacturing process of the EL display device is completed, the polyimide film layer is peeled from the peeling layer. Here, FIG. 1 and FIG. 2 show a method of manufacturing an organic EL display device described in Non-Patent Document 4. As shown in FIG. The method is as follows: After forming the release layer 2 on the glass substrate 1, a polyimide layer 3 is formed slightly larger than the release layer 2, and thereafter, performing predetermined TFT and organic EL processes to form a TFT/organic EL layer. After the EL panel part (display part) 4, cut along the cutting line 5 inside the release layer 2 to the release layer 2, and peel the polyimide layer 3 and the TFT/organic EL panel part (display part) 4 from the release layer 2 . However, in Non-Patent Document 4, there is no specific description about what kind of material is used for the peeling layer. Therefore, it is actually not clear how much force is required for separation from the release layer, and what state the surface properties of the separated polyimide layer 3 are. In addition, since the area of the release layer needs to be smaller than the area of the polyimide layer, the formable area of the organic EL display device is limited, and productivity is a problem. If the area of the peeling layer is increased to prevent a decrease in productivity, the area of the polyimide layer bonded to the glass at the outer periphery of the peeling layer decreases, and there is a problem that peeling tends to occur due to stress during the process.

In addition, the method described in Patent Document 2 is as follows: After forming a peeling layer composed of parylene or a cyclic olefin copolymer on a glass substrate, the The polyimide layer was formed to be larger than the peeling layer, and the polyimide layer was peeled off after the electronic device was fabricated thereon. The formation of TFTs required for display applications generally requires an annealing process at about 400°C. However, in this method, since the heat resistance of the release layer is inferior to that of polyimide, there are differences in the heat treatment temperature of the polyimide layer and the production process. The maximum temperature at the time of electronic equipment is limited by the issue of the heat resistance of the release layer. In addition, since the adhesion between the glass and the peeling layer and between the peeling layer and the polyimide layer is weak, the stress in the process cannot be withstood, which may cause peeling. In addition, the thermal expansion coefficient of the peeling layer is larger than that of polyimide, and the difference in thermal expansion coefficient due to the difference in the type of resin may become a bending factor.

In addition, Patent Document 3 describes a method of manufacturing a semiconductor device in which a resin film is formed on a support substrate via a release layer, a semiconductor element is formed on the resin film, and then the support substrate is peeled off from the resin film. In this patent document 3, polybenzoic acid is disclosed as a resin film. azole. In general, polybenzoic Compared with polyimide, azole has excellent peelability from other materials. Here, in general, in order to ensure good peelability with other materials, the heat treatment time in the state of contacting the adherend is preferably short, but polyimide benzo In the case of azoles, since the heterocyclic ring and the aromatic ring adopt a coplanar structure, the crystallinity tends to be high. In order to complete the reaction and sufficiently reduce the concentration of volatile components remaining in the film, heat treatment at high temperature for a long time is required. However, in this Patent Document 3, it is not clear how much force is required to separate from the peeling layer, but it is disclosed that the peeling of the peeling layer and the resin film can be achieved by immersion in warm water. In addition, the film tends to become brittle due to its high crystallinity, and if an alicyclic structure having a soft structure is introduced to prevent brittleness, there is a problem of lowering heat resistance. In addition, the introduction of the alicyclic structure also makes it difficult to reduce thermal expansion.

The methods described in these Patent Documents 2 to 3 and Non-Patent Documents 3 to 4 all use glass as a support, and form a display portion on a resin substrate fixed to the glass, thereby ensuring the operability, size and reliability of the resin substrate. stability, and has the advantage of being able to use the glass substrate directly on the original production line for manufacturing display devices such as liquid crystal display devices and organic EL display devices. Therefore, if a predetermined display part can be separated extremely easily without affecting the resin base material and the display part, it will not only be a method with excellent mass productivity, but also can further accelerate the transition from the glass substrate to the resin base material.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2008-231327

Patent Document 2: Japanese Patent Laid-Open No. 2010-67957

Patent Document 3: Japanese Patent Laid-Open No. 2009-21322

non-patent literature

Non-Patent Document 1: S.An et.al. "2.8-inch WQVGA Flexible AMOLED Using HighPerformance Low Temperature Polysilicon TFT on Plastic Substrates", SID2010DIGEST, p706(2010)

Non-Patent Document 2: Oishi et.al., "Transparent PI for flexible display", IDW'11FLX2/FMC4-1

Non-Patent Document 3: E.I. Haskal et.al. "Flexible OLED Displays Made with the EPLaR Process", Proc. Eurodisplay'07, pp.36-39 (2007)

Non-Patent Document 4: Cheng-Chung Lee et.al. "A Novel Approach to Make FlexibleActive Matrix Displays", SID10Digest, pp.810-813(2010)

Contents of the invention

Therefore, an object of the present invention is to provide a method that can easily separate the resin substrate from the support after forming a predetermined display portion on the resin substrate integrated with the support beforehand, and obtain a display device simply.

The inventors of the present invention conducted studies to solve the above-mentioned problems, and found that by forming a predetermined display part on the second resin layer in a state where the first resin layer and the second resin layer are laminated on the support body, thereafter, The boundary surface between the first resin layer and the second resin layer is separated, and a display device including a display portion on a resin base material composed of the second resin layer can be obtained extremely simply, thereby completing the present invention.

That is, the gist of the present invention is as follows.

(1) A method of manufacturing a display device, characterized in that, in a state in which the first resin layer and the second resin layer are stacked on a support, a predetermined display portion is formed on the second resin layer, and thereafter, the The interface between the first resin layer and the second resin layer is separated to obtain a display device including a display portion on a resin base material composed of the second resin layer.

(2) The method for manufacturing a display device according to (1), wherein a laminated film obtained by directly laminating the first resin layer and the second resin layer is bonded to the support, that is, the first resin layer of the laminated film is After one resin layer layer is bonded to one side of the above-mentioned support body through an adhesive layer, a predetermined display portion is formed on the laminated film, and thereafter, the interface between the first resin layer and the second resin layer is separated to obtain a A display device including a display portion on a resin base material composed of a second resin layer.

(3) The method for manufacturing a display device according to (2), wherein the first resin layer and the second resin layer constituting the laminated film are respectively composed of polyimide.

(4) The method for manufacturing a display device according to (1), wherein after forming the first polyimide layer and the second polyimide layer on the support, a predetermined display portion is further formed, wherein Thereafter, the first polyimide layer and the second polyimide layer were separated at the boundary surface to obtain a display device including a display portion on the polyimide base material composed of the second polyimide layer.

(5) The method for manufacturing a display device according to (4), wherein the support body is removed after the predetermined display portion is formed, and thereafter the boundary surface between the first polyimide layer and the second polyimide layer is It separated and obtained the display device provided with the display part on the polyimide base material.

(6) The method for manufacturing a display device according to (4) or (5), wherein the first polyimide layer is formed by laminating polyimide films, and the first polyimide layer is formed by coating polyimide or polyimide The resin solution of the imine precursor is used to form the second polyimide layer.

(7) The method for manufacturing a display device according to (4) or (5), wherein the first polyimide layer and Formation of the second polyimide layer.

(8) The method for manufacturing a display device according to any one of (4) to (7), wherein a part of the second polyimide layer protrudes from the peripheral portion of the first polyimide layer, and the The protruding part of the second polyimide layer is fixed to the support body.

(9) The method for manufacturing a display device according to any one of (4) to (7), wherein a part of one of the first polyimide layer or the second polyimide layer is obtained from the other The peripheral portion of the layer protrudes.

(10) The method for manufacturing a display device according to any one of (4) to (9), wherein the first resin layer and the second resin layer are formed after cutting a slit in the first resin layer along the outer periphery of the display portion. separation.

(11) According to the manufacturing method of the display device described in (6) or (7), the second polyimide layer is formed by heating after applying the resin solution of polyimide or polyimide precursor. When forming, the high temperature holding time of the second polyimide layer is less than 60 minutes.

(12) The method for manufacturing a display device according to any one of (1) to (11), wherein the support is a glass substrate.

(13) The method for manufacturing a display device according to any one of (1) to (12), wherein the coefficient of thermal expansion of the first resin layer is 25 ppm/K or less.

(14) The method for manufacturing a display device according to any one of (1) to (13), wherein the second resin layer has a coefficient of thermal expansion of 25 ppm/K or less.

(15) The method for manufacturing a display device according to any one of (1) to (14), wherein the transmittance of the second resin layer in the wavelength region of 440 nm to 780 nm is 80% or more.

(16) The method for manufacturing a display device according to any one of (1) to (15), wherein the display portion is formed via a gas barrier layer, and the difference in coefficient of thermal expansion between the second resin layer and the gas barrier layer is 10 ppm /K below.

(17) The method of manufacturing a display device according to any one of (1) to (16), wherein the display portion is a color filter layer.

(18) The method for manufacturing a display device according to any one of (1) to (17), wherein the peel strength between the first resin layer and the second resin layer is 200 N/m or less.

(19) The method for manufacturing a display device according to any one of (1) to (18), wherein at least one of the first resin layer or the second resin layer is represented by the following general formula (1): The structural unit is composed of polyimide.

[wherein, Ar ₁ represents a tetravalent organic group having an aromatic ring, and Ar ₂ represents a divalent organic group represented by the following general formula (2) or (3).

[Here, R ₁ to R ₈ in general formula (2) or general formula (3) are each independently a hydrogen atom, a fluorine atom, an alkyl or alkoxy group with 1 to 5 carbon atoms, or a fluorine-substituted hydrocarbon group , at least one of R ₁ to R ₄ in the general formula (2) and at least one of R ₁ to R ₈ in the general formula (3) is a fluorine atom or a fluorine-substituted hydrocarbon group. 〕]

According to the present invention, by preliminarily forming a state where the first resin layer and the second resin layer are laminated on the support body, a predetermined display portion can be formed while ensuring operability and dimensional stability. After the display portion is formed, the interface between the first resin layer and the second resin layer can be easily separated without special laser irradiation or the like, so a display device can be obtained extremely simply. Moreover, since separation does not affect the second resin layer and the display part which will be the resin base material, and does not damage the support, the support can be reused in the manufacture of the display device, greatly improving the performance of the display. Helps reduce manufacturing costs.

Description of drawings

FIG. 1 is a schematic diagram illustrating a method of manufacturing an organic EL display device in the prior art.

FIG. 2 is a schematic diagram illustrating a method of manufacturing an organic EL display device in the prior art.

FIG. 3 is a schematic diagram illustrating a method of manufacturing a display device according to the present invention.

FIG. 4 is a schematic diagram illustrating a method of manufacturing a display device according to the present invention.

FIG. 5 is a schematic view (partially enlarged view) illustrating a method of manufacturing a display device according to the present invention.

FIG. 6 is a schematic diagram illustrating a method of manufacturing a display device according to the present invention.

FIG. 7 is a schematic diagram illustrating a method of manufacturing a display device according to the present invention.

FIG. 8 is a schematic diagram illustrating a method of manufacturing a display device according to the present invention.

FIG. 9 is a schematic diagram illustrating a method of manufacturing a display device according to the present invention.

detailed description

Hereinafter, the present invention will be described in more detail with reference to the drawings, but the present invention is not limited to the following description.

The method for manufacturing a display device in the present invention is characterized in that, in a state where the first resin layer and the second resin layer are stacked on the support, a predetermined display portion is formed on the second resin layer, and thereafter, a predetermined display portion is formed on the first resin layer. The interface between the resin layer and the second resin layer is separated to obtain a display device including a display portion on a resin base material composed of the second resin layer. The details are described below. It should be noted that in the following, as a preferred example, the case where the first resin layer and the second resin layer are all formed of polyimide will be described, but at least one resin layer may also be formed of polyimide. resin formation.

In the manufacturing method of the display device of this invention, the member provided with the 1st polyimide layer and the 2nd polyimide layer previously on a support body is used. Then, a predetermined display portion is formed on the side of the second polyimide layer, and thereafter, separation is performed at the interface between the first polyimide layer and the second polyimide layer, whereby the second polyimide layer can be manufactured. A display device including a display portion on a resin substrate (polyimide substrate) composed of a polyimide layer.

More specifically, first, as shown in FIG. 3 , a support body 1 serving as a base in a manufacturing process of a display portion of a liquid crystal display device, an organic EL display device, or the like is prepared. The support body 1 is not particularly limited as long as it has chemical strength and mechanical strength capable of withstanding the thermal history and atmosphere in the manufacturing process of the display part of various display devices, and glass substrates and metal substrates can be exemplified, and glass substrates are preferably used. . As a glass substrate, the glass substrate normally used for manufacture of an organic electroluminescent display apparatus can be utilized, for example. However, in the display device manufactured by the present invention, the supporting base material of the display portion is a polyimide base material composed of the second polyimide layer 8 . In other words, the glass substrate mentioned here is a member that functions as a base when forming a display part on a polyimide base material, and ensures the handleability, size, and stability, etc., but was eventually removed and did not constitute a display device. In addition, the surface treatment for controlling the releasability of the 1st polyimide layer 7 and the 2nd polyimide layer 8 may be performed on a support body.

In the present invention, the first polyimide layer and the second polyimide layer will be arranged on the support body 1. As the method, it can be any of the following methods: 1) pre-stacking the first polyimide layer An imide layer and a second polyimide layer, and then the stacked polyimide laminated film is laminated to form a method on a support (lamination method); 2) by coating polyimide or polyimide A method (coating method) for forming a first polyimide layer and a second polyimide layer with a resin solution of an amine precursor (hereinafter also referred to as "polyamic acid"); 3) on a support A method in which polyimide films are laminated to form a first polyimide layer, and a polyimide or polyimide precursor resin solution is applied to form a second polyimide layer (combined method). In addition, here, the support body 1 and the first polyimide layer may be directly bonded and laminated, or as shown in FIG. 3 , may be laminated through an adhesive layer.

In addition, in this invention, you may form so that at least one part of arbitrary layers of a 1st polyimide layer and a 2nd polyimide layer may protrude from the peripheral part of another layer. By providing a thin portion of the polyimide layer on the outer peripheral portion of the portion where the display portion is formed, stress generated during the process can be dispersed, and the support and the polyimide layer can be prevented from being peeled off during the process. The projection distance is not particularly limited, but is preferably at least the total thickness of the first polyimide layer and the second polyimide layer, more preferably at least 10 times the total thickness.

Hereinafter, the above three methods will be described respectively.

＜Lamination method＞

FIG. 3 is a view showing a state in which a polyimide laminated film is stuck on the support body 1 via an adhesive layer 6 and a display portion is further laminated. Here, the polyimide laminated film is composed of a first polyimide layer 7 and a second polyimide layer 8, which are directly laminated in advance. Structure. In order to obtain such a polyimide laminated film, for example, coating a polyamic acid resin that becomes the second polyimide layer 8 on the polyimide film that becomes the first polyimide layer 7 The solution is dried and imidized by heat treatment thereafter (casting method). In addition, as the adhesive layer 6, other than resin adhesives, such as epoxy resin and acrylic resin, the adhesive film etc. which provided the adhesive layer on both surfaces of a support film, etc. can be used. In addition, although the adhesive layer 6 is used in this FIG. 3, as shown in FIG. 7, it is also possible to directly adhere|attach the 1st polyimide layer 7 side to the support body 1 by means, such as thermocompression bonding.

Here, the thickness of the second polyimide layer 8 constituting the laminated film is preferably 3 μm to 50 μm. If the thickness of the second polyimide layer 8 is less than 3 μm, it will be difficult to ensure the electrical insulation when forming the resin base material of the display device, prevent damage to the resin layer caused by external factors, and on the contrary, if it exceeds 50 μm, the flexibility of the display device will be affected. , transparency, etc. may be reduced. On the other hand, since the first polyimide layer 7 does not directly constitute a display device, it is preferably 10 μm or more in consideration of handling properties as a laminated film and the like. The upper limit of the thickness is not particularly limited, but it is preferably 100 μm or less in consideration of cost and the like.

As described above, the polyimide laminated film is laminated and integrated on the support body 1 through the adhesive layer 6 or without the adhesive layer 6, and then proceeds to the step of forming the display portion. Here, the process for forming the display part refers to the processing of a predetermined TFT/organic EL process, for example, in the case of an organic EL display device, and the TFT formed thereby, the organic EL element including an electrode, and a light-emitting layer, etc. correspond to Display section. Here, an organic EL that performs color display by combining a color filter with an organic EL that emits white light has also been proposed. This color filter is produced by laminating it to the TFT/organic EL side after forming it in a different route from the TFT/organic EL process, and this color filter also corresponds to a display portion. In addition, in the case of a liquid crystal display device, it refers to the process of a TFT process, and the TFT formed by this, a drive circuit, the color filter formed as needed, etc. correspond to a display part. That is, in addition to organic EL display devices and liquid crystal display devices, various display devices such as electronic paper and MEMS displays are also included. The process of forming the display part has traditionally referred to the formation of various functional layers formed on the glass substrate, that is, the reflection process. The process of producing components required for a predetermined image (movie or image), including the components obtained by this process, is collectively referred to as a display unit. Through this process, the display portion 4 is laminated and formed on the side of the second polyimide layer 8 integrated with the first polyimide layer 7 . Then, when all the display part lamination steps are completed, a cutting step of cutting into a predetermined size is performed.

Among them, FIG. 4 is a diagram showing a cutting process. In the present invention, the dicing step is not essential, and may be performed arbitrarily according to the equipment and the form of the process. Taking the manufacture of an organic EL display device as an example, dicing is performed along the cutting line 5 shown in FIG. At this time, as shown in FIG. 5 which shows the enlarged view of the cutting area 9 shown in FIG. If the layer cuts into the slit, the second polyimide layer 8 can be reliably and easily separated from the boundary surface with the first polyimide layer 7 without causing mechanical damage to the TFT/organic EL panel portion 4 .

Here, in order to easily separate the second polyimide layer 8 from the interface with the first polyimide layer 7, it is necessary to make the polyimide interface easily peelable. The form is not particularly limited, but at least one of the first and second polyimide layers uses a polyimide having a specific chemical structure.

In general, polyimide is obtained by polymerizing acid anhydride and diamine as raw materials, and is represented by the following general formula (1).

In the formula, Ar ₁ represents a tetravalent organic group that is an acid anhydride residue, and Ar ₂ is a divalent organic group that is a diamine residue. From the viewpoint of heat resistance, Ar ₁ and Ar ₂ are preferably At least one of is an aromatic residue.

As the polyimide resin preferably used in the first polyimide layer or the second polyimide layer in the present invention, for example, a polyimide having the following repeating structural unit can be mentioned,

Polyimides having repeating structural units described below are particularly preferred.

Moreover, in addition to these, fluorine-containing polyimide is mentioned. Here, the fluorine-containing polyimide refers to a polyimide having a fluorine atom in the polyimide structure, and at least one of an acid anhydride and a diamine as a raw material of the polyimide has a fluorine-containing group. As such a fluorine-containing polyimide, for example, the following compounds can be enumerated: in the polyimide represented by the above-mentioned general formula (1), Ar ₁ in the formula is a tetravalent organic group, and Ar ₂ is the following The divalent organic group represented by the general formula (2) or (3) above.

R ₁ to R ₈ in the above general formula (2) or general formula (3) are each independently a hydrogen atom, a fluorine atom, an alkyl or alkoxy group with 1 to 5 carbon atoms, or a fluorine-substituted hydrocarbon group, and the general formula At least one of R ₁ to R ₄ in (2) is a fluorine atom or a fluorine-substituted hydrocarbon group, and at least one of R ₁ to R ₈ in the general formula (3) is a fluorine atom or a fluorine-substituted hydrocarbon group.

Among them, preferred specific examples of R ₁ to R ₈ include -H, -CH ₃ , -OCH ₃ , -F, -CF ₃ , etc., but preferably at least 1 in formula (2) or formula (3). Each substituent is any one of -F or -CF ₃ .

Moreover, as a specific example of Ar1 in General formula ( ₁ ) at the time of forming a fluorine-containing polyimide, the following tetravalent acid anhydride residue is mentioned, for example.

In addition, when forming a fluorine-containing polyimide, considering the transparency of the polyimide, the peelability with other layers, etc., as a specific diamine residue to give Ar in the general _formula (1), preferably List the following groups.

If it is such a fluorine-containing polyimide, it can show good separation properties even at the interface with polyimides having other structures than the fluorine-containing polyimide (of course, if the first and second polyimides If both imide layers are made of fluorine-containing polyimide, the separability at the interface is further improved). In addition, when any of the structural units represented by the general formula (4) or (5) listed below is present in a ratio of 80 mol% or more in such a fluorine-containing polyimide, transparency and releasability are excellent. , In addition, thermal expansion is low and dimensional stability is excellent, so it is preferably used as a polyimide for forming the second polyimide layer.

Here, when the polyimide is a polyimide having a structure of the general formula (4) or (5), other polyimides other than the polyimide that can be added in a ratio of up to less than 20 mol % The imine is not particularly limited, and common acid anhydrides and diamines can be used. Among them, examples of 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, etc. On the other hand, examples of diamines include 4,4'-diaminodiphenylsulfone, trans-1,4-diaminocyclohexane, 4,4'-diaminocyclohexylmethane, 2,2' - Bis(4-aminocyclohexyl)-hexafluoropropane, 2,2'-bis(trifluoromethyl)-4,4'-diaminobicyclohexane, etc.

The various polyimides described above are obtained by imidizing polyamic acid. Here, the resin solution of polyamic acid can be obtained by using diamine and acid dianhydride as raw materials in substantially equimolar amounts. They are obtained by reacting in organic solvents. More specifically, it can be obtained by dissolving diamine in an organic polar solvent such as N,N-dimethylacetamide under nitrogen flow, adding tetracarboxylic dianhydride, and reacting at room temperature for about 5 hours. The weight-average molecular weight of the obtained polyamic acid is preferably 10,000 to 300,000 from the viewpoint of uniform film thickness at the time of coating and the mechanical strength of the obtained polyimide film. In addition, the preferable molecular weight range of a polyimide layer is also the same molecular weight range as a polyamic acid.

In the present invention, it is preferable to make the second polyimide layer 8 a polyimide having a structural unit represented by general formula (4) or (5), so that the coefficient of thermal expansion can be formed to be 25ppm/K or less, preferably 10ppm/K. A polyimide layer having K or less is suitable as a polyimide base material for forming a display device. In addition, polyimides having these structural units have a glass transition temperature (Tg) of 300° C. or higher, and have a transmittance of 80% or higher in a wavelength region of 440 nm to 780 nm.

As mentioned above, in order to be able to use the specified polyimide, it is preferable to make at least one polyimide layer be made of fluorine-containing polyimide formation. By forming at least one polyimide layer from fluorine-containing polyimide, the adhesive strength of the interface between the first polyimide layer and the second polyimide layer is preferably 1 N/m to 500 N/m , more preferably from 5 N/m to 300 N/m, and still more preferably from 10 N/m to 200 N/m, has separability to the extent that it can be easily peeled off by human hands. Moreover, in the display device obtained by separation, the second polyimide layer as the polyimide base material has no defects in appearance such as wrinkles and fractures. In addition, the separation surface of the second polyimide layer can be maintained by casting The surface roughness obtained by the method (generally, the surface roughness Ra = about 1 to 80 nm), so it does not adversely affect the visibility of the display device.

In addition to 1) the method of forming a predetermined display part and then separating the interface between the first polyimide layer and the second polyimide layer, the present invention also includes the following method: 2) forming a predetermined display After the section, first, remove the support on the side of the first polyimide layer, and then separate the remaining first polyimide layer and the second polyimide layer at the boundary surface to obtain the polyimide layer A display device including a display portion on an amine substrate (second polyimide layer). In the method of the above-mentioned 2), the separation of the first polyimide layer 7 and the second polyimide layer 8 after removing the support body 1 is preferably in the shape of the second polyimide layer 8 and the display portion 4. The first polyimide layer 7 is separated while being fixed while maintaining a constant state during the separation. Thereby, the stress which the display part 4 receives can be reduced, and even when the 2nd polyimide layer 8 is made thinner, the possibility of damage to the device of the display part 4 can be reduced. Here, in the method of the above-mentioned 2), the method of removing the support body is not particularly limited as long as it does not damage the display portion 4 or the second polyimide layer 8, and the method described below can be used. That is, since the example using the adhesive layer 6 was shown in the said description based on FIG. 3, this point will be supplemented in the description of the coating method based on FIG. However, in the lamination method, if the first polyimide layer 7 can be directly bonded to the support 1 by means of thermocompression bonding, etc., the adhesive layer 6 is not necessary as shown in FIG. 3 . In this case, the support body 1 can be removed by the same method as described later.

Next, application examples using the coating method of the present invention will be described.

＜Coating method＞

FIG. 6 is a view showing a state in which a first polyimide layer 7 and a second polyimide layer 8 are sequentially formed on a support body 1 by a coating method, and thereafter, a display portion 4 is further laminated. In this method, first, a support body 1 is prepared, and a resin solution of polyamic acid that becomes the first polyimide layer 7 is coated on it, and drying and imidization are completed by heat treatment to form the first polyimide layer. Layer 7. Next, the polyamic acid resin solution that becomes the second polyimide layer 8 is coated on the above-mentioned first polyimide layer 7, and the drying and imidization are completed by heat treatment to form the second polyimide layer. Layer 8. Thereby, the board|substrate in which the 1st polyimide layer 7 and the 2nd polyimide layer 8 were sequentially formed on the support body 1 can be produced. Thereafter, it is continuously supplied to the steps after the display portion forming step. Since the steps after the display portion forming step are the same as the above-mentioned lamination method, details are omitted, and the removal of the support body 1 in the method of the above-mentioned 2) will be briefly described below.

As described above, FIG. 6 is a diagram showing a state in which the first polyimide layer 7 , the second polyimide layer 8 , and the display portion 4 are stacked on the support body 1 . In the present invention, the support body 1 can be removed from this state to the step of separating the boundary surface between the first polyimide layer 7 and the second polyimide layer 8, and here, as a method of removing the support body 1 , the following method can be exemplified: use a polyimide material that is easily peeled off from the support body 1 as the first polyimide layer 7, or use metal foil such as copper foil, or a metal substrate as the support body 1, and remove them with an etching solution .

In addition, as a method of removing the support body 1 , other known methods can also be used. That is, the support body 1 can be removed by laser irradiation in Non-Patent Document 3 or the peeling layer in Non-Patent Document 4. When the support body 1 is removed by laser irradiation, the first polyimide layer absorbs the laser light, and the adverse effect of the laser light on the second polyimide layer and the display portion can be prevented. When the support body 1 is removed by the peeling layer, the first polyimide layer resists the stress generated at the time of peeling, functions as a stress relaxation layer, and can prevent a decrease in yield due to damage to the display portion at the time of peeling.

However, in JP 2007-512568, it is disclosed that a yellow film such as polyimide is formed on glass, and then thin-film electronic elements are formed on the yellow film, and then UV laser light is irradiated on the bottom surface of the yellow film through the glass. , so that the glass and the yellow film can be peeled off. However, it is also disclosed that, unlike a yellow film, a transparent plastic does not absorb UV laser light, so it is necessary to provide an absorption/release layer such as amorphous silicon under the film in advance. On the other hand, JP 2012-511173 A discloses that in order to peel the glass and the polyimide film by UV laser irradiation, it is necessary to use laser light within a spectral range of 300 to 410 nm.

In the present invention, when the support is removed from the first polyimide layer by laser, it is preferable to use colored polyimide for the first polyimide layer. It is one of the preferred aspects of the present invention to make the first polyimide layer a colored polyimide and make the second polyimide layer a transparent polyimide.

In the coating method, the resin solution of the polyamic acid that becomes the first polyimide layer 7 is coated on the support body 1, and heat treatment is carried out. At this time, the first polyimide layer is imidized by sufficient heat treatment. Amination facilitates separation of the second polyimide layer and is therefore preferred. Also in the coating method, it is preferable to use a polyimide having a specific chemical structure for at least one of the first and second polyimide layers, similarly to the description in the lamination method. The first polyimide layer and the second polyimide layer may be polyimides having the same chemical structure.

In the coating method, the first polyimide layer and the second polyimide layer are all obtained by drying or drying and curing by heat treatment after coating the resin solution. In the present invention, the ratio of temperature increase in the above heat treatment The heating time (hereinafter referred to as high temperature holding time) from the temperature 20°C lower than the maximum heating temperature (maximum reaching temperature) to the maximum reaching temperature in the high temperature heating temperature region (hereinafter referred to as high temperature holding time) is as short as possible within the range to obtain the desired characteristics. This is because the purpose of maintaining the first and/or second polyimide layer in the high temperature heating temperature region in the coating method is to obtain the original polyimide layer by promoting the complete removal of residual solvent, orientation of polyimide resin, etc. Properties required for the imine layer. However, when the high-temperature retention time of the second polyimide layer is particularly long, the peelability from the first polyimide layer tends to decrease, or the transmittance tends to decrease due to coloring or the like. The optimal high temperature holding time varies depending on the heating method, the thickness of the polyimide, and the type of polyimide, but is preferably 0.5 minutes to less than 60 minutes, more preferably 0.5 minutes to less than 30 minutes.

Next, an application example of the combined method of film lamination and resin solution coating according to the present invention will be described.

＜Concurrent usage＞

8 is a diagram showing a state in which a first polyimide layer 7 is attached on a support 1 by an adhesive layer 6, and a second polyimide layer 8 and a display portion 4 are laminated thereon, wherein the first The polyimide layer 7 is cut one circle smaller than the support body 1 .

In this method, first, the support body 1 is prepared, and the polyimide film used as the 1st polyimide layer 7 is stuck on it by the adhesive layer 6. This step can use the same polyimide film as the above lamination method, using the same method.

Next, on the above-mentioned first polyimide layer 7, a resin solution of polyamic acid that becomes the second polyimide layer 8 is coated, and dried by heat treatment to complete imidization to form a second polyimide layer. Amine layer 8. This step can use the same resin solution as the above-mentioned coating method, using the same method. Thereby, the board|substrate in which the 1st polyimide layer 7 and the 2nd polyimide layer 8 were sequentially formed on the support body 1 can be produced. Thereafter, it is continuously supplied to the steps after the display portion forming step. The steps subsequent to the display portion forming step are the same as the above-mentioned steps, and thus are omitted.

In the combined method, after bonding the first polyimide layer 7 and the support body 1, the resin solution of polyamic acid imparted to the second polyimide layer 8 is coated on the first polyimide layer in the state of varnish. imine layer 7 and cover its entire surface. The coated polyamic acid resin solution is dried and imidized through heat treatment to form a second polyimide layer 8. As shown in FIG. The second polyimide layer 8 is larger than the first polyimide layer, and at least a part of the portion not in contact with the first polyimide layer 7 of the second polyimide layer 8 is in contact with the support body 1 . That is, a part of the second polyimide layer 8 protrudes from the peripheral portion of the first polyimide layer 7 , and the protruding portion of the second polyimide layer 8 is fixed to the support body 1 . In this method, the second polyimide layer 8 and the first polyimide layer 7 are also formed in a manner that is easy to peel off, but the second polyimide layer 8 and the support body 1 can be separated by the second polyimide layer. Since the protruding part of the layer 8 is firmly bonded, it is possible to improve the adhesiveness around the support body and further ensure the stability in the process. It should be noted that after the display portion is formed, it can be carried out in the same manner as the above-mentioned cutting process. For example, as shown in FIG. Layer 8 is separated at the boundary surface of the first polyimide layer 7 and the second polyimide layer 8, then it can be obtained on the polyimide substrate composed of the second polyimide layer 8. A display device of the display unit 4 .

In the present invention, including the case of using the above three methods and the case of using methods other than these methods, the first polyimide layer will be separated later, so it does not contribute to the function of the display device, but Considering the temperature change of the display unit during the manufacturing process, the characteristics before separation become an important factor. From this viewpoint, the thermal expansion coefficient of the first polyimide layer is preferably 25 ppm/K or less. In addition, the glass transition temperature Tg is preferably 300° C. or higher. As a specific example of such a 1st polyimide layer, the polyimide etc. which have the structural unit which consists of biphenyltetracarboxylic dianhydride and phenylenediamine as a main component are mentioned, for example. As a commercial item, for example, UPILEX-S manufactured by Ube Industries, Ltd., Kapton manufactured by Du Pont-Toray Co., Ltd., and XENOMAX manufactured by Toyobo Co., Ltd. can be used.

In addition, in the present invention, when forming the display portion, it is possible to use a film made of inorganic oxide films such as silicon oxide, aluminum oxide, silicon carbide, silicon oxycarbide, silicon carbonitride, silicon nitride, silicon oxynitride, etc. Barrier gas barrier layer for oxygen, water vapor, etc. At this time, in order to reduce warping and the like of the resulting display device, it is preferable that the difference in thermal expansion coefficient between the second polyimide layer and the gas barrier layer is 10 ppm/K or less.

In a method other than using polyimide having a specific chemical structure for the first or second polyimide layer, in order to separate the first polyimide layer 7 and the second polyimide layer 8 from their sides The interface is easily separated, for example, a method of using a laminated film made by performing heat treatment of the first polyimide layer 7 and the like to change the surface state of the first polyimide layer 7 to reduce the surface area. After the wettability is obtained, the coating of the second polyimide layer 8 is carried out quickly. The appropriate temperature for this heat treatment differs depending on the type of the first polyimide layer 7, and the first polyimide layer 7 is made of polyimide such as KAPTON manufactured by DU PONT-TORAY Co., Ltd. and UPILEX manufactured by Ube Industries, Ltd. In the case of an amine film, it is preferably 300°C to 500°C.

In the present invention, in the method of separating the interface between the first polyimide layer and the second polyimide layer after forming a predetermined display portion, the support obtained by separating the second polyimide layer The second polyimide layer is formed again on the first polyimide layer side of the laminated body of the support body and the first polyimide layer, so that the laminated body of the support body and the first polyimide layer can be reused. In the case of repeated use, the laminated body of the support body and the first polyimide layer may be washed after separating the second polyimide layer. In addition, it is also possible to apply the second polyimide layer after heat-treating the laminate of the support and the first polyimide layer to reduce the wettability of the surface of the first polyimide layer. .

In addition, as another method of repeatedly using the laminated body of the support body and the first polyimide layer, the following method may also be used: the support body obtained by separating the second polyimide layer and the first polyimide layer On the first polyimide layer side of the laminated body, the first polyimide layer was formed again, and then the second polyimide layer was formed.

Moreover, in this invention, the support body removed from the 1st polyimide layer can be reused. Before reuse, cleaning, heat treatment, and surface treatment of the support may be performed.

Example

Hereinafter, based on an Example, this invention is demonstrated more concretely. It should be noted that the present invention is not limited to the contents of the following examples.

Evaluation methods of physical properties and the like are shown in the following Examples.

〔Transmittance(%)〕

Use a U4000 type spectrophotometer to obtain the average value of the light transmittance of the polyimide film (50mm×50mm) at 440nm to 780nm.

〔Glass transition temperature (Tg)〕

The glass transition temperature was obtained as follows: using a viscoelastic analyzer (RSA-II manufactured by Rheometric Scientific F.E. Co., Ltd.), using a sample with a width of 10 mm, while applying 1 Hz vibration, the temperature was raised from room temperature to 10 °C/min. 400°C, obtained from the maximum value of the loss tangent value (Tanδ) at this time.

〔Coefficient of thermal expansion (CTE)〕

Use a thermomechanical analysis (TMA) device to apply a load of 5.0g to a polyimide film with a size of 3mm×15mm, and at the same time perform a tensile test at a temperature range of 30°C to 260°C at a certain heating rate (20°C/min). , The coefficient of thermal expansion (×10 ^-6 /K) was measured from the elongation of the polyimide film corresponding to the temperature.

[Example 1]

The resin solution of polyamic acid obtained from PDA (1,4-phenylenediamine) and BPDA (3,3',4,4'-biphenyltetracarboxylic dianhydride) is coated with a thickness of 20 μm after curing. It was coated on a glass substrate as a support body so that the area was 300 mm×380 mm, and heated and dried at 130° C. to remove the solvent (DMAc: N,N-dimethylacetamide) in the resin solution. Next, imidization is performed by heat treatment at a heating rate of about 1°C/min from 160°C to 360°C to form a first polyimide layer with a thickness of 20 μm (surface roughness Ra=1.3nm, Tg=355 ℃).

From PMDA (pyromellitic dianhydride), 6FDA (2,2'-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride) and TFMB (2,2'-bis(trifluoromethyl) -4,4'-diaminobiphenyl) The resin solution of polyamic acid obtained is larger than the coating area of the first polyimide layer and covers the entire first polyimide layer, and the coating area is 310mm ×390 mm, and the thickness after curing was 25 μm, and it was coated on the first polyimide layer, and heated and dried at 130° C. to remove the solvent (DMAc: N,N-dimethylacetamide) in the resin solution. Next, heat treatment was performed from 160° C. to 360° C. at a rate of temperature increase of about 20° C./min to perform imidization, and a second polyimide layer with a thickness of 25 μm was formed. The high temperature retention time at this time was 1 minute. In addition, in the synthesis|combination of the said polyamic acid, a diamine component and an acid dianhydride component were approximately equimolar, and the ratio of PMDA/6FDA was 85/15.

In this way, a laminate in which the first and second polyimide layers were sequentially laminated on glass was produced, and an EL element serving as a display portion was formed on the second polyimide layer side of the laminate. Thereafter, cut a slit in the second polyimide layer in a manner that surrounds the display portion, peel and separate the interface between the first polyimide layer and the second polyimide layer, and obtain the A display device having an EL element on a polyimide substrate composed of an amine layer. At this time, between the first polyimide layer and the second polyimide layer, in the case of not causing damage to the equipment of the display part such as TFT and electrodes, artificially peel off without using methods such as laser peeling, This enables easy separation. The peel strength between the first polyimide layer and the second polyimide layer was 3.5 N/m. It should be noted that in the above embodiment, the linear expansion coefficient of the first polyimide layer is 12.0 ppm/K, and the linear expansion coefficient of the second polyimide layer is 9.7 ppm/K. In addition, the transmittance of the second polyimide layer in the wavelength region of 440 nm to 780 nm was 83.5%.

[Example 2]

The resin solution of polyamic acid obtained from PDA (1,4-phenylenediamine) and BPDA (3,3',4,4'-biphenyltetracarboxylic dianhydride) is coated with a thickness of 20 μm after curing. It was coated on a glass substrate as a support body so that the area was 310 mm×390 mm, and was heated and dried at 120° C. to remove the solvent (DMAc: N,N-dimethylacetamide) in the resin solution. Next, imidize by heat treatment at a heating rate of about 1°C/min from 130°C to 360°C to form a first polyimide layer with a thickness of 25 μm (surface roughness Ra=1.3nm, Tg=355 ℃).

From PMDA (pyromellitic dianhydride), 6FDA (2,2'-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride) and TFMB (2,2'-bis(trifluoromethyl) -4,4'-diaminobiphenyl) The polyamic acid resin solution obtained is coated on the first polyimide layer in a manner that the coating area is 310mm×390mm and the thickness after curing is 5 μm. The solvent (DMAc:N,N-dimethylacetamide) in the resin solution was removed by heating and drying at 130°C. Next, heat treatment was performed from 160° C. to 360° C. at a rate of temperature increase of about 20° C./min to perform imidization, and a second polyimide layer with a thickness of 5 μm was formed. In addition, in the synthesis|combination of the said polyamic acid, a diamine component and an acid dianhydride component were approximately equimolar, and the ratio of PMDA/6FDA was 60/40.

In this way, a laminate in which the first and second polyimide layers were sequentially laminated on glass was produced, and an EL element serving as a display portion was formed on the second polyimide layer side of the laminate. Thereafter, a notch is cut along the thickness direction of the first polyimide layer and the second polyimide layer so as to surround the display portion, and after peeling and removing the glass on the side of the first polyimide layer, The interface between the imide layer and the second polyimide layer was peeled off to obtain a display device having an EL element on a polyimide base material composed of the second polyimide layer. At this time, between the glass and the first polyimide layer and between the first polyimide layer and the second polyimide layer, under the condition of not causing damage to the equipment of the display part such as TFT and electrodes, It can be easily separated by artificially peeling without using methods such as laser peeling. The peel strength between the first polyimide layer and the second polyimide layer was 4.0 N/m. It should be noted that, in the above embodiment, the linear expansion coefficient of the first polyimide layer is 7.0 ppm/K, and the linear expansion coefficient of the second polyimide layer is 20.4 ppm/K. In addition, the transmittance of the second polyimide layer in the wavelength region of 440 nm to 780 nm was 86.7%.

(Example 3)

In order to reuse the laminate of the support and the first polyimide layer obtained by peeling and separating the second polyimide layer in Example 1, after removing the remaining peripheral portion of the second polyimide layer, use pure After washing with water, heat treatment was performed for 2 minutes at each temperature of 100°C, 200°C, 300°C, and 360°C.

On the first polyimide layer, apply the polyamic acid resin solution in the same manner as the second polyimide layer in Example 1, heat and dry at 130°C, and then heat and dry it from 160°C to 360°C The temperature was raised at a rate of about 20° C./min, and kept at 360° C. for 60 minutes to form a second polyimide layer with a thickness of 25 μm. The high temperature retention time at this time was 61 minutes.

In this way, a laminate in which the first polyimide layer and the second polyimide layer were sequentially laminated on glass was prepared, and a display device was obtained in the same procedure as in Example 1. In addition, the peeling strength of a 1st polyimide layer and a 2nd polyimide layer was 10.0 N/m, and it was easy to separate by human hands. In addition, the linear expansion coefficient of the second polyimide layer was 9.3 ppm/K, and the transmittance of the second polyimide layer in the wavelength region of 440 nm to 780 nm was 78.5%.

(Example 4)

By m-TB (2,2'-dimethylbenzidine) 17.70g, TPE-R (1,3-bis (4-aminophenoxy) benzene 4.3g and PMDA (pyromellitic dianhydride) 17.20 g, BPDA (3,3',4,4'-biphenyltetracarboxylic dianhydride) 5.8g obtained polyamic acid resin solution, the thickness after curing is 25μm, and the coating area is 310mm×390mm Coated on a glass substrate as a support, heated and dried at 120°C to remove the solvent (DMAc: N,N-dimethylacetamide) in the resin solution. Next, from 130°C to 160°C at about 15 Heat treatment was performed at a temperature increase rate of °C/min to perform imidization to form a first polyimide layer with a thickness of 25 µm (surface roughness Ra=1.0 nm, Tg=360°C).

On this first polyimide layer, in the same manner as the second polyimide layer of Example 1, the polyamic acid resin solution was coated with a coating area of 306 mm × 386 mm, and heated and dried at 130° C. Next, the temperature was raised from 160° C. to 360° C. at a rate of about 20° C./minute, and kept at 360° C. for 30 minutes to form a second polyimide layer with a thickness of 25 μm. The high temperature retention time at this time was 31 minutes.

In this way, a laminate in which the first polyimide layer and the second polyimide layer were sequentially laminated on glass was prepared, and a display device was obtained by the same procedure as in Example 2. The peel strength of the first polyimide layer and the second polyimide layer was 110 N/m, and they could be separated by human hands. It should be noted that the linear expansion coefficient of the first polyimide layer was 20.0 ppm/K, and the linear expansion coefficient of the second polyimide layer was 9.5 ppm/K. In addition, the transmittance of the second polyimide layer in the wavelength region of 440 nm to 780 nm was 80.5%.

(Example 5)

A resin solution of polyamic acid obtained from PDA (1,4-phenylenediamine) and BPDA (3,3',4,4'-biphenyltetracarboxylic dianhydride) is coated so that the cured thickness is 20 μm The solvent (DMAc: N,N- dimethylacetamide) in the resin solution was removed by spreading on copper foil and drying by heating at 130°C. Next, heat treatment is carried out at a heating rate of about 1°C/min from 160°C to 360°C for imidization, and a first polyimide layer (surface roughness Ra=1.3nm) with a thickness of 20 μm is formed on the copper foil. , Tg=355°C).

From PMDA (pyromellitic dianhydride), 6FDA (2,2'-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride) and TFMB (2,2'-bis(trifluoromethyl) -4,4'-diaminobiphenyl) The resin solution of the polyamic acid obtained by curing was coated on the first polyimide layer so that the thickness after curing was 25 μm, and the resin solution was removed by heating and drying at 130°C. solvent (DMAc: N,N-dimethylacetamide). Next, heat treatment was performed from 160° C. to 360° C. at a rate of temperature increase of about 20° C./min to perform imidization, and a second polyimide layer with a thickness of 25 μm was formed. In addition, in the synthesis|combination of the said polyamic acid, a diamine component and an acid dianhydride component were approximately equimolar, and the ratio of PMDA/6FDA was 85/15.

The copper foil part of the laminate composed of copper foil/the first polyimide layer/the second polyimide layer is removed by ferric chloride etching, and the first polyimide layer/the second polyimide layer is obtained. A laminated film composed of amine layers.

This laminated film was bonded to a glass substrate as a support with an epoxy resin-based adhesive, and then an EL element as a display portion was formed on the second polyimide layer side. Then, the interface of the 1st polyimide layer and the 2nd polyimide layer was separated by peeling, and the display device which has an EL element on a polyimide base material was obtained. The first polyimide layer and the second polyimide layer can be easily separated without damaging the devices of the display portion, such as TFTs and electrodes. It should be noted that in the above embodiment, the linear expansion coefficient of the first polyimide layer is 12.0 ppm/K, and the linear expansion coefficient of the second polyimide layer is 9.7 ppm/K. In addition, the transmittance of the second polyimide layer in the wavelength region of 440 nm to 780 nm was 83.5%.

Symbol Description

1 glass substrate

2 Peel off layers

3 polyimide layer

4 Display part (TFT/organic EL panel part)

5 cutting lines

6 adhesive layer

7 The first polyimide layer

8 Second polyimide layer

9 cutting area

10 cut faces

Claims (17)

1. a kind of manufacture method of display device, it is characterised in that the first polyimide layer and second is formed on supporter and is gathered After imide layer, further formed on the second polyimide layer as defined in display part, thereafter, in the first polyimide layer and the The boundary face of two polyimide layers is separated, and obtains possessing aobvious on the polyimide base material being made up of the second polyimide layer Show the display device in portion,

A part for second polyimide layer is stretched out from the periphery of the first polyimide layer, the stretching of second polyimide layer Supporter is fixed in portion.

2. a kind of manufacture method of display device, it is characterised in that the first polyimide layer and second is formed on supporter and is gathered After imide layer, further formed on the second polyimide layer as defined in display part, thereafter, in the first polyimide layer and the The boundary face of two polyimide layers is separated, and obtains possessing aobvious on the polyimide base material being made up of the second polyimide layer Show the display device in portion,

A part for the layer of a side in first polyimide layer or the second polyimide layer is stretched out from the periphery of other layers.

3. a kind of manufacture method of display device, it is characterised in that the first polyimide layer and second is formed on supporter and is gathered After imide layer, further formed on the second polyimide layer as defined in display part, thereafter, in the first polyimide layer and the The boundary face of two polyimide layers is separated, and obtains possessing aobvious on the polyimide base material being made up of the second polyimide layer Show the display device in portion,

Along the periphery of display part behind the first polyimide layer incision gap, the first polyimide layer and the second polyimides are carried out The separation of layer.

4. according to the manufacture method of display device according to any one of claims 1 to 3, it is characterised in that by the first polyamides The stacked film that imine layer and the second polyimide layer are directly laminated is fitted with supporter, i.e. by the first of the stacked film After polyimides aspect is fitted with the one side of the supporter via adhesive linkage, defined display part is formed on stacked film, its Afterwards, separated, obtained by the second polyimide layer structure with the boundary face of the second polyimide layer in the first polyimide layer Into polyimide base material on possess the display device of display part.

5. according to the manufacture method of display device according to any one of claims 1 to 3, wherein, forming defined show Supporter is removed behind portion, is separated in the first polyimide layer with the boundary face of the second polyimide layer thereafter, is obtained poly- Possesses the display device of display part on acid imide base material.

6. according to the manufacture method of display device according to any one of claims 1 to 3, wherein, by being laminated polyimides Film carries out the formation of the first polyimide layer, and second is carried out by the resin solution for being coated with polyimides or polyimide precursor The formation of polyimide layer.

7. according to the manufacture method of display device according to any one of claims 1 to 3, wherein, it is poly- by being coated with heating The resin solution of acid imide or polyimide precursor carries out the formation of the first polyimide layer and the second polyimide layer.

8. the manufacture method of display device according to claim 7, wherein, by sub- in coating polyimides or polyamides When the formation to carry out the second polyimide layer is heated after the resin solution of amine precursor, when the high temperature of the second polyimide layer is kept Between be less than 60 minutes.

9. according to the manufacture method of display device according to any one of claims 1 to 3, wherein, supporter is glass substrate.

10. according to the manufacture method of display device according to any one of claims 1 to 3, wherein, the first polyimide layer Thermal coefficient of expansion is below 25ppm/K.

11. according to the manufacture method of display device according to any one of claims 1 to 3, wherein, the second polyimide layer Thermal coefficient of expansion is below 25ppm/K.

12. according to the manufacture method of display device according to any one of claims 1 to 3, wherein, the second polyimide layer exists The transmissivity of 440nm~780nm wavelength region is more than 80%.

13. according to the manufacture method of display device according to any one of claims 1 to 3, wherein, display part hinders across gas Interlayer is formed, and the difference of the thermal coefficient of expansion of the second polyimide layer and gas-barrier layer is below 10ppm/K.

14. according to the manufacture method of display device according to any one of claims 1 to 3, wherein, display part is colour filter Layer.

15. according to the manufacture method of display device according to any one of claims 1 to 3, wherein, the first polyimide layer with The peel strength of second polyimide layer is below 200N/m.

16. according to the manufacture method of display device according to any one of claims 1 to 3, wherein, the first polyimide layer or At least one party in the polyimide layer of person second is made up of the polyimides of the construction unit represented with following formulas (1),

In formula, Ar₁Represent the organic group of 4 valencys with aromatic rings, Ar₂The divalent represented for following formulas (2) or (3) it is organic Group,

Wherein, the R in formula (2) or formula (3)₁~R₈It is each independently hydrogen atom, fluorine atom, the alkane of carbon number 1~5 Base or alkoxy or fluorine substituted hydrocarbon radical, the R of formula (2)₁~R₄In at least one and formula (3) R₁~R₈In extremely Few 1 is fluorine atom or fluorine substituted hydrocarbon radical.

17. according to the manufacture method of display device according to any one of claims 1 to 3, wherein, the first polyimide layer or At least one party in the polyimide layer of person second is made up of the polyimides of the construction unit represented with following formulas (6),