JP6752611B2 - Electro-optic panel and its manufacturing method - Google Patents

Description

The present invention relates to an electro-optical panel including a display panel and a lighting panel, and a method for manufacturing the same.

Electro-optical panels such as OLED (organic light-emitting diode) display panels, OLED lighting panels, cholesteric liquid crystal display panels, PDLC (polymer dispersed liquid crystal) display panels, and electrophoresis display panels include electro-optical elements (for example, light emitting elements and It has a plurality of layers in addition to the liquid crystal element (for example, Patent Document 1). In this specification, the "electro-optical element" includes a light emitting element (for example, an OLED element) that emits light by the action of electricity and an optical control element (for example, a liquid crystal element) that controls the transmission of light by the action of electricity. The "electro-optical panel" refers to a panel having such an electro-optical element. In recent years, flexible display panels and lighting panels have been developed, these flexible electro-optical panels have a plurality of laminated films, at least some of which are formed from a polymeric material (eg resin). Has been done.

Japanese Unexamined Patent Publication No. 2014-049436

In such an electro-optical panel, a plurality of films formed from a polymer material may be adhered with an adhesive (for example, a pressure-sensitive adhesive). For example, in order to improve the strength of the flexible OLED display panel, a reinforcing film (front film) may be adhered to the flexible substrate (flexible film).

However, the adhesive does not contribute to improving the function or reliability of the display or lighting. Not only that, when an adhesive is used, the thickness of the adhesive hinders the reduction of the thickness of the electro-optical panel. Especially for a flexible electro-optical panel, it is desirable that the thickness is small.

Therefore, it is conceivable to directly bond the films by pressurizing them while heating them. However, when the glass transition temperature of the material of these films is high, the heating temperature required for direct bonding must be raised, and a light emitting element such as an OLED may be damaged. In order to increase the strength of the electro-optical panel, polyimide is often used as the flexible substrate, and the glass transition temperature of the polyimide is high, and may be 350 ° C. or higher.

Further, when the glass transition temperature of the material of these films is high, the surface of the film remains hard even if it is heated to a temperature lower than the glass transition temperature, and even if it is pressurized, the surface is uneven, so that the film is between the films. The distance does not shrink, and as a result, the bonding force is weak.

Therefore, an object of the present invention is to provide an electro-optical panel and a method for manufacturing the same, which can reduce the overall thickness and firmly bond two films even at a low heating temperature.

In one aspect of the present invention, the electro-optical panel is an electro-optical panel including a plurality of films formed from a polymer material, and two of the films are directly bonded by covalent bonding and directly bonded. The glass transition temperature of the material of at least one of the two films is 49 ° C. or lower. When joining "covalently" in this specification, the object is may be joined only by the action of covalent bonds, they may be joined by the action of covalent intermolecular forces.

The at least one film may be formed from a polyethylene composition having a glass transition temperature of 49 ° C. or lower.

One of the two directly bonded films may be formed of polyimide, and the other film may be formed of a polyethylene composition having a glass transition temperature of 49 ° C. or lower.

In another aspect according to the present invention, the electro-optical panel is an electro-optical panel including a plurality of films formed from a polymer material, and is formed from the polymer material between two films of the films. The intermediate layer is arranged, and the intermediate layer and each of the two films are covalently bonded, and the glass transition temperature of the material of the intermediate layer is 49 ° C. or lower.

The intermediate layer may be formed of a polyethylene composition having a glass transition temperature of 49 ° C. or lower.

In another aspect of the present invention, the method for manufacturing an electro-optical panel is a method for manufacturing an electro-optical panel including a plurality of films formed from a polymer material, and the surface activity of two of the films is surface active. To apply the chemical treatment
The surfaces of the two films that have been subjected to the surface activation treatment are brought into contact with each other, and the two films are directly bonded by pressurizing the two films while heating. The glass transition temperature of the material of at least one of the films is 49 ° C. or lower.

The at least one film is formed of a polyethylene composition having a glass transition temperature of 49 ° C. or lower, and in the direct bonding, the two films are heated to a temperature range of 40 ° C. to 90 ° C. Good.

Prior to the surface activation treatment, the electro-optical element may be mounted on at least one of the two films directly bonded.

In another aspect of the present invention, the method for producing an electro-optical panel is a method for producing an electro-optical panel including a plurality of films formed from a polymer material, and the surface of at least one of the films. To coat the coating material, which is a polymer material, at least to apply a surface activation treatment to the coating material, and to make the two films face each other with the coating material subjected to the surface activation treatment sandwiched between them. By pressurizing the at least one film, the other film, and the coating material while heating, the two films and the coating material are directly bonded to each other, and the material of the coating material is transferred to glass. The temperature is 49 ° C or lower.

The coating material is formed of a polyethylene composition having a glass transition temperature of 49 ° C. or lower, and in the direct bonding, the at least one film, the other film, and the coating material are bonded from 40 ° C. It may be heated to a temperature range of 90 ° C.

Prior to the coating, the electro-optic element may be mounted on at least one of the two films that are directly bonded.

According to the present invention, the overall thickness of the electro-optical panel can be reduced, and the two films can be firmly bonded even at a low heating temperature.

It is sectional drawing which shows typically an example of the conventional OLED display panel. It is sectional drawing which shows schematicly the OLED display panel which concerns on 1st Embodiment of this invention. It is a figure which shows one process of manufacturing of the OLED display panel of FIG. It is an enlarged schematic view which shows the result of the process of FIG. It is a figure which shows the process after the process of FIG. It is an enlarged schematic diagram which shows the ideal bonding state of two films of the manufactured OLED display panel. It is an enlarged schematic diagram which shows the poor bonding state of two films of the manufactured OLED display panel. It is an enlarged schematic diagram which shows the bonding state of two films of the manufactured OLED display panel which concerns on 1st Embodiment. It is a table which shows the experimental result which concerns on 1st Embodiment. It is sectional drawing which shows schematicly the OLED display panel which concerns on 2nd Embodiment of this invention. It is a figure which shows one process of manufacturing of the OLED display panel of FIG. It is a figure which shows the process after the process of FIG. It is sectional drawing which shows schematicly the OLED display panel which concerns on the modification of this invention. It is sectional drawing which shows schematicly the OLED display panel which concerns on the modification of this invention.

The objects, advantages and novel features of the present invention will become more apparent from the following detailed description associated with the accompanying drawings. In different drawings, the same reference numerals are used to indicate the same or functionally similar elements. Please understand that the drawings are schematic and the scale of the drawings is not accurate.

As shown in FIG. 1, an example of a conventional OLED display panel has a flexible substrate (flexible film) 10 and a barrier layer (barrier film) 12 formed on the flexible substrate (flexible film) 10. The flexible substrate 10 is made of a polymer material, for example, polyimide. The barrier layer 12 is formed of a polymer material or an inorganic material.

A TFT (thin film transistor) layer 14, a color filter layer 16, and an OLED layer 18 are formed on the barrier layer 12. Although not shown in detail, the inside of the TFT layer 14 has a large number of TFTs and an interlayer insulating film covering the TFTs. Further, the color filter layer 16 has not only a color filter but also an interlayer insulating film and wiring that connects the TFT and the electrode of the OLED layer 18 through the interlayer insulating film. The OLED layer 18 has layers such as an anode, a cathode, and a light emitting layer.

A capsule encapsulant 20 formed of, for example, glass or polyimide is bonded to the barrier layer 12, and the capsule encapsulant 20 covers and protects the TFT layer 14, the color filter layer 16, and the OLED layer 18. .. Further, a metal sealing layer 22 is bonded onto the capsule sealing body 20.

This OLED display panel is a bottom emission type that emits the light generated in the OLED layer 18 toward the flexible substrate 10 side (that is, the lower part of the figure). A front film (reinforcing film) 24 is adhered to the flexible substrate 10 via an adhesive layer 26 in order to improve the strength of the OLED display panel. As the adhesive layer 26, a pressure sensitive adhesive (PSA) is used. The front film 24 is made of a polymeric material, such as a polyethylene composition.

1st Embodiment FIG. 2 schematically shows an OLED display panel 1 according to the first embodiment of the present invention. The OLED display panel 1 is a bottom emission type like the OLED display panel of FIG. In the OLED display panel 1, the adhesive layer 26 is eliminated, and the front film 24 is directly bonded to the flexible substrate 10 by covalent bonding. As will be described later, the glass transition temperature of the material of at least one of the directly bonded front film 24 and the flexible substrate 10 is preferably 49 ° C. or lower.

Next, a method of manufacturing the OLED display panel 1 according to the first embodiment will be described with reference to FIGS. 3 to 5. FIG. 3 shows one step of manufacturing the OLED display panel 1. Prior to the step of FIG. 3, a light emitting element (electro-optical element) is mounted on the flexible substrate 10. That is, the barrier layer 12, the TFT layer 14, the color filter layer 16, the OLED layer 18, the capsule encapsulant 20 and the metal encapsulant layer 22 are formed on the flexible substrate 10 to create the structure 2.

Next, as shown in FIG. 3, a surface activation treatment is applied to the exposed surface 10a of the flexible substrate 10 and one surface 24a of the front film 24. The surface activation treatment is a treatment for generating hydroxyl groups, and includes, for example, a plasma irradiation treatment, a vacuum ultraviolet (VUV) irradiation treatment, and an excimer UV treatment. As a result, hydrophilic functional groups are generated on the surface 10a and the surface 24a as shown in the schematic view enlarged in FIG.

After that, as shown in FIG. 5, either the structure 2 or the front film 24 is inverted, and the surface 10a and the surface 24a subjected to the surface activation treatment are brought into contact with each other. Next, by pressurizing the structure 2 including the flexible substrate 10 and the front film 24 while heating, they are directly bonded by a covalent bond using a functional group to complete the OLED display panel 1 shown in FIG. The pressure used for pressurization in the direct joining step is generally 0.05 MPa to 5 MPa, preferably 0.1 MPa to 4 MPa, and more preferably 0.2 MPa to 3 MPa. The pressure is preferably small from the viewpoint of preventing the light emitting element from being destroyed. The surface 10a and the surface 24a may be bonded only by the action of covalent bond, or may be bonded by the cooperative action of covalent bond and intermolecular force.

FIG. 6 is an enlarged schematic view showing an ideal bonding state between the flexible substrate 10 and the front film 24. In an ideal bonding state, both the surface 10a of the flexible substrate 10 and the surface 24a of the front film 24 are flat, and the functional groups generated on the surface 10a of the flexible substrate 10 and the functional groups generated on the surface 24a of the front film 24 are flat. The groups are uniformly bonded. Therefore, the bonding strength, that is, the peeling strength is extremely high.

However, in reality, both the surface 10a of the flexible substrate 10 and the surface 24a of the front film 24 have irregularities. Therefore, as shown in FIG. 7, only a part of the functional groups generated on the surface 10a is on the surface 24a. It may not be possible to bond to the generated functional group. For example, if the pressure used in the direct bonding process is low, or the temperature used in the direct bonding process is (the glass transition temperature of the material of the flexible substrate 10 and / or the glass transition temperature of the material of the front film 24). On the other hand, when it is low, the poor joining state shown in FIG. 7 occurs. From another point of view, when the glass transition temperature of the material of the flexible substrate 10 and / or the glass transition temperature of the material of the front film 24 is high, the poor bonding state shown in FIG. 7 also occurs. In this case, the flexible substrate 10 and the front film 24 cannot be bonded, or even if they are bonded, the bonding strength, that is, the peeling strength is extremely low.

On the other hand, when the pressure used in the direct bonding process is high and / or the temperature used in the direct bonding process is (the glass transition temperature of the material of the flexible substrate 10 and / or the glass transition of the material of the front film 24). When it is high (relative to temperature), the good bonding state shown in FIG. 8 occurs. In this case, due to the high pressure and / or high heating temperature, most of the functional groups generated on the surface 10a are attached to the functional groups generated on the surface 24a. Moreover, due to the high pressure and / or high heating temperature, the surface 10a and / or the surface 24a is flattened as compared to the state of FIG. From another point of view, when the glass transition temperature of the material of the flexible substrate 10 and / or the glass transition temperature of the material of the front film 24 is low, the good bonding state shown in FIG. 8 also occurs. In this case, the bonding strength, that is, the peeling strength is high.

An experiment was conducted to investigate the appropriate glass transition temperature and the appropriate heating temperature of the material of the flexible substrate 10 and / or the material of the front film 24. The experimental results are shown in FIG.

Polyimide was used as the material of the flexible substrate 10. As the material of the front film 24, a polyethylene terephthalate (PET) composition having a high glass transition temperature (Tg) and two polyethylene (PE) compositions having a low glass transition temperature were used. The polyethylene terephthalate composition is a composition containing polyethylene terephthalate as a main component and containing other additives, and the polyethylene composition is a composition containing polyethylene as a main component and containing other additives. The high Tg PET composition is "A4300" manufactured by Toyobo Ltd., and the low Tg PET compositions # 1 and # 2 are prototypes manufactured by Unitika Ltd. The glass transition temperature of the high Tg PET composition is 78 ° C., the glass transition temperature of the low Tg PE composition # 1 is 49 ° C., and the glass transition temperature of the low Tg PE composition # 2 is 29 ° C. is there. The low Tg PE composition # 2 contains an inorganic substance.

The thickness of the front film formed of the high Tg PET composition was 50 μm, and the thickness of the front film of the low Tg PE composition was 25 μm. However, it is considered that the thickness of the front film does not affect the bonding strength.

As the surface activation treatment, a vacuum ultraviolet (VUV) irradiation treatment was performed for 20 seconds. However, 0s in FIG. 9 indicates that the surface activation treatment was not performed. Then, the direct joining step was performed at 150 ° C., 90 ° C., 70 ° C., 60 ° C., 50 ° C., 40 ° C., and 24 ° C. (room temperature). The pressure in the direct joining step was 0.1 MPa, and the time in the direct joining step was 180 seconds. However, in FIG. 9, "-" indicates that the test was not performed because the result can be predicted from other results.

As shown in FIG. 9, the front film and the flexible substrate formed of the high Tg PET composition were adhered at 150 ° C. However, at 150 ° C., a light emitting element such as an OLED may be damaged. At temperatures below 90 ° C., the front film formed of the high Tg PET composition did not adhere to the flexible substrate.

On the other hand, the front film formed of the low Tg PE composition # 1 can be adhered to the flexible substrate by using heating temperatures of 90 ° C., 70 ° C., and 40 ° C. when VUV irradiation treatment is performed. did it. It is considered that the same applies to the heating temperatures of 50 ° C. and 60 ° C. A 180-degree peeling test was performed on the sample that was successfully bonded. The description under "adhesion" in FIG. 9 shows the result of the 180 degree peeling test, and "PE break" means that the front film was broken instead of peeling at the interface between the front film and the flexible substrate. To do. The fact that the front film is broken means that the bonding strength at the interface between the polyimide and the PE composition is higher than the strength of the PE composition itself. This proves that a strong bond has been achieved due to the covalent bond utilizing the functional group. Values such as 0.7 kgf and 1.0 kgf represent the force required for peeling, but since the PE has been cut, it is not the original peel strength but the fracture strength.

The front film formed of the low Tg PE composition # 2 could be adhered to the flexible substrate using heating temperatures of 90 ° C., 70 ° C., and 60 ° C. when subjected to VUV irradiation treatment. .. A 180-degree peeling test was performed on the sample that was successfully bonded. The description under "adhesion" in FIG. 9 shows the result of the 180 degree peeling test, and "interface peeling" means peeling at the interface between the front film and the flexible substrate. The fact that the interface peeling occurs means that the bonding strength at the interface between the polyimide and the PE composition is lower than the strength of the PE composition itself.

The low Tg PE composition # 2 had a lower Tg than the low Tg PE composition # 1, but the heating temperature required to adhere to the flexible substrate was higher. This is because the low Tg PE composition # 2 contains an inorganic substance, so that the low Tg PE composition # 2 is less likely to generate functional groups (less), and the surface irregularities are larger. It is thought to be caused.

From the above experimental results, it was confirmed that with respect to the flexible substrate 10 formed of polyimide, the front film 24 is preferably formed of a polyethylene composition having a glass transition temperature of 49 ° C. or lower. Further, in the direct bonding step, it is preferable to heat the flexible substrate 10 and the front film 24 in a temperature range of 40 ° C. to 90 ° C. Considering the low Tg PE composition # 2, it is more preferable to heat the flexible substrate 10 and the front film 24 in the temperature range of 60 ° C. to 90 ° C. in the direct bonding step.

In the above experiments, the flexible substrate 10 is made of polyimide. However, even in the case where a film formed from another polymer material and a film formed from a polyethylene composition are directly bonded by a covalent bond, the glass transition temperature of the polyethylene composition is preferably 49 ° C. or lower. Is estimated. Since polyimide generally has a considerably high glass transition temperature among polymer materials, it is expected that even if polyimide is replaced with another polymer material, good bonding strength (or even higher bonding strength) will be obtained. Because. For the same reason, even when two films formed from a polyethylene composition are directly bonded by a covalent bond, the glass transition temperature of the polyethylene composition, which is the material of at least one film, is preferably 49 ° C. or lower. Is presumed. More generally, when two films formed from a polymer material are directly bonded by a covalent bond, the glass transition temperature of the material of at least one of the two directly bonded films is 49 ° C. or less. It is presumed that the material of these films is not limited to polyethylene compositions, but may be various polymer materials including elastomers and various resins.

According to this embodiment, since the flexible substrate 10 and the front film 24 are directly bonded by covalent bonding without using an adhesive, the overall thickness of the OLED display panel can be reduced. Further, depending on the bonding method, a strong bonding may be realized due to a covalent bond using a functional group.

Further, since the glass transition temperature of the material of at least one of the two directly bonded films is 49 ° C. or lower, the two films can be firmly bonded even at a low heating temperature. Therefore, in a panel using an electro-optical element that is sensitive to heat, damage to the electro-optical element can be prevented.

Since a material having a high glass transition temperature is generally hard, if foreign matter is present between the flexible substrate 10 and the front film 24, the electro-optical element formed on the flexible substrate 10 may be damaged. However, in this embodiment, since at least one of the flexible substrate 10 and the front film 24 is formed of a material having a low glass transition temperature, it is possible to reduce the risk of such damage.

Adhesives often become cloudy when repeatedly subjected to bending stress. The flexible OLED display panel 1 naturally receives repeated bending stresses. As is clear from the comparison between FIGS. 1 and 2, when the adhesive layer 26 is in the middle of the path through which the light emitted from the OLED layer 18 of the OLED display panel is emitted, the cloudy adhesive layer 26 is visually recognized. It interferes with the quality of the image. For other types of flexible display panels, the quality of the visible image is impaired if there is a cloudy adhesive layer in the middle of the path of light emitted from or through the electro-optic element. Even in a flexible lighting panel, if there is a cloudy adhesive layer in the middle of the path through which the light emitted from the light emitting element is emitted, non-uniform brightness occurs.

In this embodiment, since the flexible substrate 10 and the front film 24 are directly bonded by covalent bonding without using an adhesive, there is no deterioration in image quality due to cloudiness of the adhesive. Even if the OLED display panel 1 is replaced with another type of flexible display panel, there is no deterioration in image quality due to the cloudiness of the adhesive. Even if the OLED display panel 1 is replaced with a lighting panel, there is no non-uniformity in the brightness distribution due to the cloudiness of the adhesive. However, the present invention is not limited to flexible panels.

As described above, in the manufacturing method according to this embodiment, the electro-optical element is attached to at least one of the two films directly bonded before the surface activation treatment (that is, before the bonding of the front film 24). Implement. Even when vacuum ultraviolet rays are used as the surface activation treatment, the penetrating ability of the vacuum ultraviolet rays is weak, so that the vacuum ultraviolet rays are absorbed by the flexible substrate 10 or the like, and there is little risk of deterioration of the electro-optical element, particularly the OLED layer 18. Conceivable. However, conversely, the electro-optical element may be mounted after joining the front film 24.

Second Embodiment FIG. 10 schematically shows an OLED display panel 31 according to a second embodiment of the present invention. Unlike the OLED display panel 1 according to the first embodiment, in the OLED display panel 31, an intermediate layer 32 formed of a polymer material is arranged between the flexible substrate 10 and the front film 24, and the intermediate layer 32 is arranged via the intermediate layer 32. The flexible substrate 10 and the front film 24 are joined together. Microscopically, the intermediate layer 32 and the flexible substrate 10 are covalently bonded, and the intermediate layer 32 and the front film 24 are also covalently bonded. The glass transition temperature of the material of the intermediate layer 32 is preferably 49 ° C. or lower. The intermediate layer 32 and the flexible substrate 10 and / or the front film 24 may be bonded only by the action of covalent bond, or may be bonded by the cooperative action of covalent bond and intermolecular force.

Next, a method of manufacturing the OLED display panel 31 according to the second embodiment will be described. FIG. 11 shows one step of manufacturing the OLED display panel 1. Prior to the process of FIG. 11, a light emitting element (electro-optical element) is mounted on the flexible substrate 10. That is, the barrier layer 12, the TFT layer 14, the color filter layer 16, the OLED layer 18, the capsule encapsulant 20 and the metal encapsulant layer 22 are formed on the flexible substrate 10 to create the structure 34.

Next, one of the exposed surface of the flexible substrate 10 and one surface 24a of the front film 24 is coated with a coating material 36 (material of the intermediate layer 32) which is a polymer material. In the example of FIG. 11, the coating material 36 is coated on the flexible substrate 10, but instead of or in addition to this, the coating material 36 may be coated on the front film 24. The coating method may be spray, roll, jet or other known method.

Next, as shown in FIG. 11, at least the coating material 36 is subjected to the same surface activation treatment as in the first embodiment to generate hydrophilic functional groups in the coating material 36. If the coating material 36 is coated on both the flexible substrate 10 and the front film 24, both coating materials may be subjected to surface activation treatment. If the coating material 36 is coated on one of the flexible substrate 10 and the front film 24, the surface activation treatment may be applied not only to the coating material 36 but also to the surface of the uncoated flexible substrate 10 or the front film 24. ..

After that, as shown in FIG. 12, either the structure 34 or the front film 24 is inverted so that the flexible substrate 10 and the front film 24 face each other with the coating material 36 interposed therebetween. Next, by pressurizing the structure 34 including the flexible substrate 10, the intermediate layer 32, and the front film 24 while heating, the flexible substrate 10 and the intermediate layer 32 are directly bonded by a covalent bond using a functional group, and the front film is formed. The 24 and the intermediate layer 32 are directly bonded by a covalent bond using a functional group to complete the OLED display panel 31 shown in FIG. The pressure used for pressurization in the direct joining step is generally 0.05 MPa to 5 MPa, preferably 0.1 MPa to 4 MPa, and more preferably 0.2 MPa to 3 MPa. The pressure is preferably small from the viewpoint of preventing the light emitting element from being destroyed.

In this embodiment, the amount and thickness of the coating material 36 may be sufficient to provide bonding between the flexible substrate 10 and the front film 24. Therefore, the thickness of the intermediate layer 32 is small, and the overall thickness of the OLED display panel can be reduced as compared with the case where an adhesive is used. Further, depending on the bonding method, a strong bonding may be realized due to a covalent bond using a functional group.

Further, since the glass transition temperature of the material of the intermediate layer 32 is 49 ° C. or lower, the two films can be firmly bonded even at a low heating temperature. Therefore, in a panel using an electro-optical element that is sensitive to heat, damage to the electro-optical element can be prevented.

Further, since the intermediate layer 32 is generally made of a soft material having a low glass transition temperature, even if there is a foreign substance between the flexible substrate 10 and the front film 24, the electro-optical element formed on the flexible substrate 10 is damaged. It is possible to reduce the risk.

Further, in this embodiment, since the flexible substrate 10 and the front film 24 are joined by a covalent bond without using an adhesive, there is no deterioration in image quality due to cloudiness of the adhesive. Even if the OLED display panel 31 is replaced with another type of flexible display panel, there is no deterioration in image quality due to the cloudiness of the adhesive. Even if the OLED display panel 31 is replaced with a lighting panel, there is no non-uniformity in the brightness distribution due to the cloudiness of the adhesive. However, the present invention is not limited to flexible panels.

As described above, in the manufacturing method according to this embodiment, before the coating of the coating material 36 (that is, before the bonding of the front film 24), the electro-optical element is applied to at least one of the two films to be bonded. Implement. Even when vacuum ultraviolet rays are used as the surface activation treatment, the penetrating ability of the vacuum ultraviolet rays is weak, so that the vacuum ultraviolet rays are absorbed by the flexible substrate 10 or the like, and there is little risk of deterioration of the electro-optical element, particularly the OLED layer 18. Conceivable. However, conversely, the electro-optical element may be mounted after joining the front film 24.

The material of the coating material 36 is preferably a polyethylene composition having a glass transition temperature of 49 ° C. or lower. However, it is not limited to the polyethylene composition, and it is considered that various polymer materials including an elastomer having a glass transition temperature of 49 ° C. or lower and various resins may be used.

Also in this embodiment, the flexible substrate 10 and the front film 24 may be formed from a polymer material having a glass transition temperature of 49 ° C. or lower.

As another modification, the joining of the flexible substrate 10 and the front film 24 has been described as an example, but the present invention can also be applied to joining other films formed from the polymer material of the electro-optical panel. For example, when the barrier layer (barrier film) 12 of the first embodiment and the second embodiment is formed from a polymer material, the first embodiment or the first embodiment is used for joining the flexible substrate 10 and the barrier layer 12. The method of the second embodiment can be applied.

Further, as shown in FIG. 13, when the retardation film 42 formed of the polymer material is bonded to the flexible substrate 10 in the other OLED display panel 41, the first embodiment or the second embodiment is joined to the bonding. Morphological techniques can be applied. Further, when the polarizing film 44 is bonded to the retardation film 42, the method of the first embodiment or the second embodiment can be applied to the bonding.

Further, as shown in FIG. 14, when the back film 52 is bonded to the flexible substrate 10 in another top emission type OLED display panel 51, the method of the first embodiment or the second embodiment is used for the bonding. Can be applied. Further, when the retardation film 54 is bonded to the flexible substrate 53 on the color filter layer 16 and when the polarizing film 56 is bonded to the retardation film 54, the bonding is performed by the first embodiment or the second embodiment. The technique can be applied.

Although the OLED display panel has been described as an example of the embodiment, the present invention can be applied to other electro-optical panels such as a cholesteric liquid crystal display panel, a PDLC display panel, an electrophoresis display panel, or a lighting panel.

1,31,41,51 OLED display panel, 2,34 structure, 10 flexible substrate (flexible film), 12 barrier layer (barrier film), 14 TFT layer, 16 color filter layer, 18 OLED layer, 20 capsule encapsulant , 22 metal encapsulation layer, 24 front film (reinforcing film), 26 adhesive layer, 32 intermediate layer, 36 coating material, 42,54 retardation film, 44,56 polarizing film, 52 back film, 53 flexible substrate.

Claims (8)

An electro-optical panel comprising a plurality of films formed from a polymer material.
Two of the films are directly bonded by covalent bonds.
One of the two directly bonded films is formed from polyimide.
The other film is an electro-optical panel formed from a polyethylene composition having a glass transition temperature of 49 ° C. or lower . An electro-optical panel comprising a plurality of films formed from a polymer material.
An intermediate layer formed of a polymer material is arranged between two of the films.
The intermediate layer and each of the two films are covalently bonded.
The two directly bonded films are made of polyimide and
The intermediate layer is an electro-optical panel formed of a polyethylene composition having a glass transition temperature of 49 ° C. or lower . A method for manufacturing an electro-optical panel including a plurality of films formed from a polymer material.
To apply surface activation treatment to two of the films,
Contacting the surfaces of the two films that have undergone surface activation treatment and
The two films are directly bonded by pressurizing while heating.
At least one of Der glass transition temperature of 49 ° C. or less of the material of the film of the two said films being bonded directly is,
One of the two films that are directly bonded is made of polyimide.
The other film is a method for producing an electro-optical panel, which is formed of a polyethylene composition having a glass transition temperature of 49 ° C. or lower . In joining pre SL directly, a method of manufacturing an electro-optical panel according to claim 3 for heating the two films to a temperature range of 90 ° C. from 40 ° C.. The method for manufacturing an electro-optical panel according to claim 3 or 4 , wherein the electro-optical element is mounted on at least one of the two films directly bonded before the surface activation treatment. A method for manufacturing an electro-optical panel including a plurality of films formed from a polymer material.
By coating the surface of at least one of the films with a coating material which is a polymer material,
At least the coating material should be surface-activated and
The two films are opposed to each other with the coating material subjected to the surface activation treatment sandwiched between them.
By pressurizing the at least one film, the other film, and the coating material while heating, the two films and the coating material are directly bonded to each other.
Ri Der glass transition temperature of 49 ° C. or less of the material of said coating material,
At least one of the plurality of films is made of polyimide.
Manufacturing method of electro-optical panel. The coating material is formed from a polyethylene composition having a glass transition temperature of 49 ° C. or less, in the above to direct bonding, wherein at least one film and the other side of the film and the coating material 40 ° C. The method for manufacturing an electro-optical panel according to claim 6 , wherein the film is heated to a temperature range of about 90 ° C. The method for manufacturing an electro-optical panel according to claim 6 or 7 , wherein the electro-optical element is mounted on at least one of the plurality of the films before the coating.

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