JP2020049706A - Release film integrated type encapsulation material for self-luminous type display - Google Patents

Abstract

To provide novel technical means capable of avoiding loss of smoothness of an encapsulation material surface generated when a release film is used, in a heat lamination process conducted during a manufacturing process of a self-luminous type display, and quality reduction of the self-luminous type display caused thereby.SOLUTION: There is provided a release film integrated type encapsulation material, which is a multilayer film by laminating an encapsulation film and a release film, the encapsulation film contains an olefin resin as a base resin, the release film has melting point of 220°C to 270°C, and adhesion strength at a boundary surface between the encapsulation film and the release film measured by a prescribed adhesion test is 0.3 N/15 mm to 3.0 N/15 mm.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a sealing material for a self-luminous display. Specifically, this sealing material is a release film-integrated sealing material in which a release film is previously integrated at the time of film formation, and improves the quality stability and productivity of the LED module for a self-luminous display. It is a sealing material that can be improved.

  As a next-generation display device that replaces various liquid crystal display devices, a self-luminous display body represented by a micro LED television is being developed (see Patent Document 1). Usually, these self-luminous display bodies are formed by laminating a sealing film for protecting a light emitting element on a surface on a light emitting surface side of a light emitting module in which a light emitting element such as an LED element is mounted on a wiring board. In this configuration, a display surface panel such as various optical films and transparent protective glass is further laminated on an LED module for a self-luminous display (see Patent Documents 2 and 3).

  For example, a sealing material for a self-luminous display constituting an LED module is required to have excellent adhesion to a glass epoxy resin or a glass plate constituting a wiring board of an LED module or the like. As an example of a sealing film having such adhesion, Patent Document 2 discloses a sealing material containing polyethylene, and Patent Document 3 discloses a sealing material containing acid-modified polyethylene having excellent glass adhesion. It has been disclosed.

  By the way, the LED module is manufactured by a heat lamination process in which a laminate formed by laminating a light-emitting module and a sealing film is heat-pressed and integrated while placed on a heating plate. In this step, in order to ensure necessary and sufficient releasability between the sealing film having excellent adhesion and the above-mentioned heating plate after the above-mentioned step, when performing the above-mentioned thermocompression bonding, It was necessary to interpose various release films made of polyester resin or the like between the film and the heating plate.

  Conventionally, as such a release film, for example, a high-performance fluororesin such as PTFE (polytetrafluoroethylene) and ETFE (ethylene tetrafluoroethylene), or a polyester resin such as PET (polyethylene terephthalate) (See Patent Document 4).

  However, when these release films are interposed and the above-described heat laminating step is performed, deformation of the release film itself due to heating, or fine foreign matter to the gap between the release film and the sealing film, In some cases, the smoothness of the surface of the sealing material after film formation is impaired due to mixing or the like. The loss of the smoothness of the surface of the sealing material causes a decrease in optical characteristics and long-term durability of the self-luminous display. At the LED module production site, new technical means for avoiding the quality deterioration due to the use of such a release film have been required.

JP 2018-14481 A JP 2017-9725 A JP 2014-148584 A JP 2017-35382 A

  The present invention has been made in view of the above situation, in the heat laminating step performed in the process of manufacturing a self-luminous display, the surface of the sealing material generated by using a release film. It is an object of the present invention to provide a new technical means capable of avoiding a loss of smoothness and a decrease in quality of a self-luminous display body caused by the loss.

  The present inventors have conducted intensive studies and found that, as a sealing material for a self-luminous display, a release film integrated sealing material in which a release film is previously integrated at the time of film formation. The inventors have found that the above problems can be solved, and have completed the present invention. Specifically, the present invention provides the following.

(1) A sealing material for a self-luminous display body, which is a multilayer film in which a sealing film and a release film are laminated, wherein the sealing film has an olefin-based resin as a base resin. The release film has a melting point of 220 ° C. or more and 270 ° C. or less, and has an adhesion strength of 0.3 N / 15 mm or more at an interface between the sealing film and the release film measured by an adhesion test described below. A release film-integrated sealing material having a thickness of 3.0 N / 15 mm or less.
Adhesion test: In a release film integrated sealing material cut to a width of 15 mm, the release film in close contact with the sealing film is vertically peeled by a peeling tester (Tensilon Universal Testing Machine RTF-1150-H). (50 mm / min) test is performed to measure the adhesion strength at the interface between both films.

  In the invention of (1), the sealing material for the self-luminous display is a multilayer film in which the sealing film and the release film are integrated in advance. In addition, the lower limit of the adhesion strength between the two films is not less than the strength that can maintain the handleability of the integrated multilayer film at a preferable level, and the upper limit is a good release. Specified below the strength that can maintain the properties. According to such a release film-integrated sealing material, the smoothness of the surface of the sealing material generated during use of the release film during the heat laminating step performed in the process of manufacturing the self-luminous display body. Loss can be avoided.

  (2) The release film according to (1), wherein the release film has a wetting index according to JIS K 6768 of 25 to 40 Dyne or less according to JIS K 6768 on the surface of the release surface that is the surface on the interface side with the sealing film. Mold film integrated sealing material.

  In the invention of (2), in the release film-integrated sealing material according to (1), on the assumption that the release film and the sealing film are integrated, the release film disposed on the interface side of both layers. The wetting index of the release surface of the mold film was adjusted to a specific range different from that of the conventional single release film. Thereby, the quality stability of the release film-integrated sealing material that satisfies the above requirements for the adhesion strength between films in the invention of (1) can be easily maintained at a favorable level.

  (3) The release according to (1) or (2), wherein the release film has a surface roughness Rz of a release surface which is a surface on the interface side with the sealing film: Rz is 0.1 or more. Film-integrated sealing material.

  In the invention of (3), in the release film-integrated sealing material according to (1) or (2), on the premise that the release film and the sealing film are integrated, the sealing material is provided on the interface side of both layers. The surface roughness of the release surface of the release film to be arranged: Rz was adjusted to a range of 0.1 or more. Thus, in a roll-to-roll type production facility, a resin film constituting a sealing film and a resin film constituting a release film are likely to be generated in a step of laminating and integrating, and wrinkles of a film running between rolls are generated. And meandering can be reduced.

  (4) The release film is a polyethylene terephthalate resin film, and the polyethylene terephthalate resin film adjusts adhesion and release properties on a release surface that is an interface side with the sealing film. The release film-integrated sealing material according to any one of (1) to (3), which is a surface-untreated polyethylene terephthalate resin film that has not been subjected to the surface treatment.

  In the invention of (4), the release film of the release film-integrated sealing material according to any one of (1) to (3), which is inexpensive, easily available, and excellent in heat resistance, is “untreated surface”. Polyethylene terephthalate resin film ". This makes it possible to maintain the quality stability and economy of the release film-integrated sealing material according to any one of (1) to (3) at extremely favorable levels.

(5) the base resin of the sealing film, the density 0.870 g / cm ³ or more 0.930 g / cm ³ or less of the polyethylene resin, the release film according to any one of (1) (4) Integrated sealing material.

  In the invention (5), the sealing film of the release film-integrated sealing material according to any one of (1) to (4) is made of a polyethylene resin having a specific density range. Thereby, the sealing performance of the light emitting module, that is, the fineness of the surface of the wiring board, which is the original performance as a sealing material of the release film-integrated sealing material according to any one of (1) to (4). It is possible to improve the wrapping performance (molding property) of the resin into the irregularities, the adhesion to the wiring board, and the protection performance against the impact of the light emitting element to particularly preferable levels.

(6) A laminate formed by laminating the release film-integrated sealing material according to (1) to (5) and a light emitting module in which a plurality of light emitting elements are mounted on a wiring board,
A heat lamination step of integrating by heating and pressing under a state of being placed on a heating plate made of metal and / or glass, wherein the thermocompression bonding is integrally performed with the release film constituting the laminate. A method for manufacturing an LED module, wherein the release film of the material is directly mounted on the heating plate without passing through another release film.

  (6) According to the invention of (6), it is possible to avoid quality deterioration and productivity deterioration due to the use of the release film at the time of the heat laminating step in the process of manufacturing the self-luminous display, and it is excellent in quality stability. A self-luminous display can be manufactured with excellent productivity.

  ADVANTAGE OF THE INVENTION According to this invention, in the thermal lamination process performed in the manufacturing process of a self-luminous display body, the loss of the smoothness of the sealing material surface which accompanies using a release film can be avoided.

A plan view of an image display surface of a self-luminous display using an LED module for a self-luminous display obtained by laminating a sealing film constituting a release film-integrated sealing material of the present invention on a light-emitting module And a partially enlarged plan view thereof. It is sectional drawing showing the cross section of AA part of FIG. It is a perspective view of the LED element which comprises the LED module for self-luminous display bodies of FIG. It is sectional drawing which shows typically an example of the layer structure of the release film integrated type sealing material of this invention. It is a figure used for explanation of the manufacturing method of the LED module for the self-luminous type display using the release film integral type sealing material of the present invention. FIG. 6 is a partially enlarged view of FIG. 5, which is used for describing a manner of mounting a sealing film on a heating plate of a laminator. It is a figure provided for explanation of the manufacturing method of the release film integral type sealing material of the present invention.

<Self-emitting display>
First, the "self-luminous display" in the present specification is a display device represented by the micro LED television exemplified above, and is a display device for visual information such as characters, images, and moving images. This display device mounts a small number and a large number of light emitting elements in a matrix on a wiring board, and selectively emits light by the light emission control means connected to the light emitting elements. This is a display device that can directly display an image on a display screen by blinking of a light-emitting element. In addition, the release film-integrated sealing material of the present invention can be particularly preferably used for an LED display device using an LED element as a light-emitting element among "self-luminous display bodies".

[Micro LED display]
FIG. 1 is a front view of a micro LED display device 100 which is an embodiment of a self-luminous display body manufactured using the release film-integrated sealing material of the present invention, and a partially enlarged view thereof (100A). It is. FIG. 2 is a cross-sectional view showing a cross section taken along the line AA of FIG. 1 and is a drawing provided for explaining a layer configuration of the micro LED display device 100 shown in FIG. The micro LED display device 100 is a self-luminous display device in which a large number of microscopic LED elements 10 are mounted on a wiring board 20 as light emitting elements. The light emission of each LED element 10 is individually controlled by light emission control means (not shown) such as an IC chip substrate which is separately bonded.

  Note that the term “micro-sized LED element” in the present specification specifically refers to the width (W) and depth (D) of the entire size of the light-emitting element including the LED light-emitting chip and the resin cover that covers the LED light-emitting chip. ) Is 300 μm or less, and the height (H) is 200 μm or less (refer to FIG. 3).

  Further, as for the size of the “micro-sized LED element”, it is more preferable that both the width and the depth are 50 μm or less and the height is 10 μm or less. This size range is a standard size range of an LED element mounted on a micro LED TV which has been developed in recent years and is expected to become a mainstream of the next-generation TV. Hereinafter, in the present specification, the width and the depth are each 50 μm or less, and the height is 10 μm or less. The self-luminous display bodies arranged in a matrix in the number of about or more are referred to as “micro LED display devices”.

  In the following, an embodiment in which the “self-luminous display” is a “micro LED display device” will be described as a particularly preferred specific example of various embodiments of the present invention. Will be described in detail. However, the technical scope of the present invention is not limited to application to only the “micro LED display device”. This technology is applicable to the “self-luminous display” as defined above.

  In this specification, a module in which a light emitting element is mounted on a wiring board is generically called a “light emitting module”. In the micro LED display device 100, the main body (111) of the release film-integrated sealing material 1 made of the sealing film 111 is further added to the light emitting module in which many LED elements 10 are mounted on the wiring board 20. The LED module 30 is configured by being stacked. When the release film-integrated sealing material 1 is incorporated into the micro LED display device 100 and integrated, the release film 121 is removed and the sealing film 111 is used as a main body made of the sealing film 111. The sealing film 111 in such a state is also referred to as a sealing material main body 111 of a release film-integrated sealing material as required for description. Details of the release film-integrated sealing material will be described later.

  Then, in the micro LED display device 100, the display surface panel 2 such as various optical films or transparent protective glass is further provided with the sealing material body 111 of the release film integrated sealing material constituting the LED module 30. It is laminated on the outer surface (display side of the micro LED display device 100).

  In addition, a plurality of light-emitting modules for a self-luminous display body are joined in a matrix on the same plane, and a sealing material body 111 is laminated on the joined light-emitting modules in the same manner as described above, so that a large An LED module for a self-luminous display, and further, a large micro LED display device can be configured.

(LED module)
As shown in FIG. 2, the wiring board 20 constituting the LED module 30 is formed on the surface of the support board 21 in a form capable of conducting with the LED element 10 by, for example, a metal such as copper or another conductive member. This is a circuit board on which the wiring section 22 is formed. As the support substrate 21, it is preferable to use a rigid substrate such as a conventionally known glass epoxy substrate or a glass substrate as a substrate for an electronic circuit.

  In the LED module 30, as shown in FIG. 2, the LED element 10 is mounted on the wiring portion 22 via the solder layer 23 in a conductive manner.

  The size of the LED module 30 is not particularly limited, but a diagonal length of about 50 inches to 200 inches is generally preferred from the viewpoint of cost performance. As described above, a plurality of LED modules 30 for the self-luminous display are joined in a matrix on the same plane to form the light-emitting surface of the self-luminous display such as the large micro LED display device 100. can do. For example, 100 × 100 LED modules 30 each having a diagonal length of 6 inches can be joined vertically and horizontally to form a micro LED television having a large screen with a diagonal length of 600 inches.

(LED element)
The LED element 10 included in the LED module 30 is a light emitting element using light emission at a PN junction where a P-type semiconductor and an N-type semiconductor are joined. A structure in which a P-type electrode and an N-type electrode are provided on the upper and lower surfaces of the element and a structure in which both P-type and N-type electrodes are provided on one side of the element have been proposed. Although the LED element 10 of any structure can be used for the micro LED display device 100 of the present invention, the LED element 10 has a small size such as the LED element disclosed as “chip electronic component” in JP-A-2006-339551. Can be particularly preferably used. The LED element disclosed in this document is said to have a size of width × depth × height of approximately 25 μm × 15 μm × 2.5 μm.

  The LED element 10 preferably includes an LED light emitting chip 11 and a resin cover 12 that covers the LED light emitting chip 11. As the resin cover 12, an organic insulating material such as an epoxy resin, a silicon resin, and a polyimide resin is used. Among these, the epoxy resin is particularly preferably used. The resin cover 12 formed of epoxy resin not only protects the LED light emitting chip 11 from physical impact, but also protects the LED light emitting chip 11 into the semiconductor caused by the difference in the refractive index between the semiconductor constituting the LED light emitting chip 11 and air. This is because it also serves to suppress the total reflection of light and increase the luminous efficiency of the LED element 10. The release film-integrated sealing material 1 is also preferable as a sealing material to be mounted on the micro LED display device 100 in that it is formed of an olefin-based resin having excellent adhesion to an epoxy resin.

  The self-luminous display of the present invention is an LED element including an LED light-emitting chip and a resin cover that covers the LED light-emitting chip, each having a width and a depth of 300 μm or less, and a height of 200 μm or less. An LED element having a size can be preferably used. In this case, the arrangement interval of the LED elements is preferably 0.03 mm or more and 100 mm or less.

  The self-luminous display of the present invention is an LED element including an LED light-emitting chip and a resin cover that covers the LED light-emitting chip, wherein each of the width and the depth is 50 μm or less, and the height is However, an extremely small LED element having a size of 10 μm or less can be more preferably used. In this case, the arrangement interval of the LED elements is preferably 0.03 mm or more and 100 mm or less. Such a mounting mode of the LED element is, specifically, a standard mounting mode of the LED element in the micro LED television.

[Release film integrated type sealing material]
As shown in FIG. 4, the release film-integrated sealing material 1 for a self-luminous display is a multilayer film in which a sealing film 111 and a release film 121 are laminated. The sealing film 111 serves as the sealing material body 111 of the release film-integrated sealing material 1 in the LED module 30 on which a large number of small-sized LED elements are mounted, while exhibiting good molding properties and By covering and laminating the LED element 10 and the LED element 10, a sealing function of protecting the LED element 10 from external impact or the like is exhibited. On the other hand, the release film 121 exerts a function of smoothly detaching the sealing film 111 from the heating plate of the laminator at the end of the thermal lamination.

In the release film-integrated sealing material 1 for a self-luminous display, the sealing film 111 and the release film 121 may be bonded to each other with a predetermined adhesive strength by heat compression or the like. The adhesion strength at the interface between the films is adjusted to a specific range that can maintain the adhesion between the films at the time of integration and good releasability. Specifically, the adhesion strength at the interface between the sealing film 111 and the release film 121 measured by the following adhesion test may be 0.3 N / 15 mm or more and 3.0 N / 15 mm or less.
(Adhesion test)
"In a release film integrated sealing material cut to a width of 15 mm, the release film in close contact with the sealing film is vertically peeled off by a peeling tester (Tensilon Universal Tester RTF-1150-H) (50 mm / min) Perform a test and measure the adhesion strength of each surface. "

  When the above-mentioned adhesion strength at the interface between the sealing film 111 and the release film 121 is less than 0.3 N / 15 mm, the sealing film 111 is “smoothly detached from the release film 121 at the end of the thermal lamination processing. There is no problem in that it can be done. However, in this case, delamination between layers is likely to occur at a stage before being installed as a multilayer film on a laminator or the like, which is not preferable in that the handleability is reduced.

  On the other hand, if the adhesion strength exceeds 3.0 N / 15 mm, the ease of peeling at the end of the thermal laminating process is reduced, and the sealing film 111 is “smoothly detached” from the release film 121. This is not preferable in that it becomes difficult.

  Here, the above-mentioned "the sealing film 111 can be smoothly detached from the release film 121" means, more specifically, that the release film-integrated sealing material 1 is a cylindrical rod having a diameter of 30 mm. While it has an interlayer adhesion that does not cause interlayer delamination in a winding bending test, it also means a state in which it can be extremely easily delaminated by hand.

(Sealing film (sealing material body))
The sealing film (sealing material main body) 111 constituting the release film-integrated sealing material 1 is formed of a resin composition containing an olefin-based resin as a base resin. As a base resin of the sealing film (sealing material main body) 111, an ethylene-vinyl acetate copolymer resin (EVA) or a low-density polyethylene resin can be used. Among them, it can be particularly preferably used a density 0.870 g / cm ³ or more 0.930 g / cm ³ or less of polyethylene resin. In the present specification, the “base resin” refers to a resin having the largest content ratio among resin components of the resin composition in the resin composition containing the base resin.

  When the sealing film (sealing material body) 111 is formed of a polyethylene resin, more specifically, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), or metallocene-based linear low-density polyethylene (M-LLDPE) can be preferably used. Among them, M-LLDPE synthesized using a metallocene catalyst which is a single site catalyst can be particularly preferably used. M-LLDPE has a small number of side chains and a uniform distribution of comonomer, so that the molecular weight distribution is narrow and it is easy to make the ultra-low density, so that the LED module 30, the micro LED display device 100, etc. In the self-luminous display device described above, the adhesion of the sealing film (sealing material main body) 111 to the wiring substrate 20 made of a glass epoxy resin plate, a glass plate, or the like can be particularly excellent.

  Further, the sealing film (sealing material main body) 111 can contain a silane component as needed. Thereby, the above-mentioned adhesion with the wiring board 20 can be improved to a more preferable level.

  The sealing film (sealing material main body) 111 may have a single-layer structure, but may have a multilayer structure in which the same layer is further formed by laminating a plurality of layers composed of resin compositions having different compositions. It may be. For example, the sealing film (sealing material main body) 111 is made of a core layer made of a polyethylene resin having a relatively high density and excellent heat resistance, and a sheet surface made of a polyethylene resin having a relatively low density and excellent adhesion. A sealing film (sealing material main body) having an excellent balance between heat resistance and adhesiveness by, for example, forming an adhesive layer by unevenly distributing the above-mentioned silane component only on the skin layer. 111.

  As a material of the “silane component” to be contained in the sealing film (sealing material main body) 111, a silane-modified polyethylene resin can be used. This silane-modified polyethylene resin is obtained by graft-polymerizing a linear low-density polyethylene (LLDPE) or the like as a main chain with an ethylenically unsaturated silane compound as a side chain. In such a graft copolymer, the degree of freedom of the silanol group that contributes to the adhesive strength increases. Thereby, the adhesion and the adhesion durability of the sealing film (sealing material main body) 111 to the wiring board 20 such as a glass epoxy substrate can be improved. The silane-modified polyethylene resin can be produced, for example, by the method described in JP-A-2003-46105.

  The thickness of the sealing film (sealing material body) 111 is preferably 50 μm or more and 500 μm or less. However, when the LED element 10 to be covered is a very small LED element having a height of 10 μm or less, the thickness of the sealing film (sealing material main body) 111 may be 25 μm or more and 100 μm or less. preferable. The thickness of the sealing film (sealing material main body) 111 is 50 μm or more or 25 μm or more, depending on the size of the LED element to be covered, so that the LED element is sufficiently protected from external impact. can do. On the other hand, when the thickness of the sealing film (sealing material main body) 111 is 1000 μm or less, the molding property in the heat laminating step is easily exerted. Specifically, at the time of thermal lamination processing in a state in which the LED element 10 is covered, the resin forming the sealing film (sealing material main body) 111 has unevenness on the surface of the wiring board 20 on which the LED element 10 is mounted. It is easy to make a good lamination with no gaps. Also, when the LED element to be covered is an extremely small size LED element having a height of 10 μm or less, if the thickness of the sealing film (sealing material main body) 111 is 100 μm or less, the integrated In the later self-luminous display, the light transmittance of the sealing material body 111 made of the sealing film 111 can be easily maintained at a preferable level.

(Release film)
The melting point of the release film 121 constituting the release film integrated sealing material 1 may be 220 ° C. or more and 270 ° C. or less. For this reason, the release film 121 can be formed of a resin composition using a resin having a melting point of 220 ° C. or more and 270 ° C. or less as a base resin. From such a viewpoint, as the base resin of the release film 121, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), or the like can be preferably used.

  The release film 121 is characterized in that the surface of the release surface 122 on the interface side with the sealing film 111 has a wetting index according to JIS K 6768 of 25 Dyne or more and 40 Dyne or less. If the wetting index of the release surface 122 is 25 Dyne or more, the release film may be removed between the time when it is completed in an integrated state as a multilayer film and the time when it is distributed as a product and subjected to heat lamination processing. The necessary adhesion between the films required as the body sealing material 1 can be ensured. On the other hand, if the wetting index of the release surface 122 is 40 Dyne or less, the releasability enough to allow the sealing film 111 to be smoothly separated from the release film 121 after the thermal lamination processing is maintained. Can be.

  In order to adjust the wetting index of the release surface 122 of the release film-integrated sealing material 1 to be within the above range, at least when the resin film constituting the release film 121 is integrated with the sealing film 111, the release index is determined. It is preferable to use a “surface-untreated polyethylene terephthalate resin film” that has not been subjected to a surface processing treatment for adjusting the adhesion and the releasability, on the surface to be the surface 122. "Surface processing for adjusting the adhesion and release properties" refers to, for example, corona treatment for improving the adhesion, or various surface coating treatments for enhancing the releasability, and other similar purposes. All known surface processing methods to be performed are included.

  The wetting index of the treated surface of polyethylene terephthalate (corona-treated PET) having a surface subjected to a general corona treatment is about 50 Dyne, exceeding the upper limit of 40 Dyne. In addition, as described above, the surface wetting index of a fluorine-based film that has been conventionally generally used as a release film is usually about 20 Dyne, which is less than the lower limit.

  As described above, conventionally, the releasability of the sealing film from the heating plate or the like of the sealing film at the time of the thermal lamination processing is such that a separate release film, which is separately and easily facilitated, is previously placed on the heating plate or the like. Was secured by keeping. As the release film preferably used in this case, for example, a release agent such as silicone was applied to improve the release property, that is, "a surface processing treatment for adjusting the release property" The applied release film has been widely used. However, if these release films having improved release properties are used as the release film 121 of the release film-integrated sealing material 1, a resin film that forms the sealing film 111 made of an olefin-based resin may be used. When integrated at the time of film formation, the adhesion between the layers is insufficient, and delamination is likely to occur frequently from the end of the laminate constituting the multilayer film. On the other hand, when the above-mentioned “surface-untreated polyethylene terephthalate resin film” is used as the resin film constituting the release film 121, such occurrence of delamination is sufficiently prevented, and The required releasability can be maintained.

  The release surface 122 of the release film 121 preferably has a surface roughness Rz (JIS B 0601-2001) of 80 nm or more. Surface roughness: When Rz is less than 80 nm, when the resin film forming the sealing film 111 and the resin film forming the release film 121 are integrated in a roll-to-roll production facility, Wrinkles and meandering are likely to occur, and the fine shaping treatment as described above can sufficiently prevent problems during production. In addition, in the conventional single release film, the shaping treatment performed to enhance the releasability is usually performed such that the surface roughness of the release surface: Rz (JIS B 0601-2001) exceeds 500 nm. However, the surface roughness Rz of the release surface 122 of the release film-integrated sealing material 1 is at most 500 nm or less in order to maintain the necessary interlayer strength of the multilayer film. It is preferable to stop at.

[Production method of release film integrated sealing material for self-luminous display]
The release film-integrated sealing material of the present invention is formed by laminating a sealing material composition for forming each layer in a film-forming step of melting and forming each of the formed sheets, and heat-pressing the formed sheets. It can be manufactured through a laminating step of integration. This melt molding can be performed by a molding method usually used for ordinary thermoplastic resins, that is, various molding methods such as injection molding, extrusion molding, hollow molding, compression molding, and rotational molding. Each of these steps can be continuously performed online, for example, in a roll-to-roll production facility as shown in FIG.

  FIG. 7 is a diagram provided for explaining a method of manufacturing the release film-integrated sealing material 1, and schematically illustrates an example of an embodiment in which the above-described steps are performed by a roll-to-roll type production facility 50. It is shown in a typical way. In the roll-to-roll production facility 50, the molten resin forming the sealing film 111 is extruded from the T die 51, and is nipped between the rubber roll 541 and the embossing roll 542, whereby the sealing film is formed. A film-shaped resin substrate 111a constituting 111 is formed. At that time, the film-shaped resin base material 121a constituting the release film 121 is also drawn out from the first paper feed roll 52 between the rubber roll 541 and the emboss roll 542, and both base materials are pressed. Integrated. At this time, if necessary, another functional film 131a is also supplied from the second paper feed roll 53 and is similarly integrated. Each of the integrated base materials is wound around the discharge roll 54 via the cooling roll 543 in a state of an integrated laminated body.

  In the release film-integrated sealing material 1 of the present invention, the surface roughness (release surface) of the release film 121 (the film-like resin base material 121a constituting the release film 121) is set to Rz80 nm or more. By holding, the minimum slipperiness between the resin base material 111a forming the sealing film 111 and the resin base material 121a forming the release film 121 is maintained, and the roll-to-roll production is performed. In equipment, it is possible to reduce the occurrence of fine wrinkles and meandering when traveling between rolls of guide rolls such as the rubber roll 541 and the emboss roll 542, which are likely to occur in the step of laminating and integrating. When the surface roughness is less than 80 nm, slippage between the guide roll and the film is reduced, and when meandering or the like occurs, wrinkles are easily formed, and the step of laminating and integrating may be difficult.

<Method of manufacturing self-luminous display>
[Method of manufacturing LED module]
The LED module 30 for a self-luminous display constituting the micro LED display device 100 includes a wiring board 20 on which the LED elements 10 are mounted and the release film-integrated sealing material 1 on the sealing film 111 side. It can be obtained by performing a heat laminating step of laminating in such a manner that the surface covers the wiring board 20, and then heat-compressing and laminating the laminated body mounted on a heating plate of a laminator.

  In this heat laminating step, as shown in FIGS. 5 and 6, the above-mentioned laminate is directly or auxiliary heated by heating the side of the release film 121 of the release film integrated sealing material 1 to the heating plate 41 of the laminator 40. It can be carried out by placing the plate via the plate 42 and, in this state, pressing the laminate holding plate 43 to the laminate by evacuation. The auxiliary heating plate 42 is an auxiliary member arranged to compensate for the lack of smoothness of the surface of the heating plate 41 made of an iron plate or the like, and is usually a glass plate such as a blue plate glass having thermal conductivity and surface smoothness. Is used. In the present specification, the “heating plate” includes not only the heating plate 41 alone, but also a laminate including both of them when the auxiliary heating plate 42 is laminated on the heating plate 41. Heating plate ".

  Specifically, the mounting of the laminate on the heating plate 41 (42) is performed by directly placing the exposed surface 123 of the release film 121 of the release film-integrated sealing material 1 on the heating plate 41 (42). Do it. At this time, usually, a release film integrated type sealing material 1 wider than the wiring substrate 20 on which the LED elements 10 are mounted is prepared, and the sealing film 111 is compatible with the module size when integrated. A process of cutting off an unnecessary end of the sealing film 111 is performed in such a manner that the release film 121 is half-cut so as to have an appropriate size.

  In the sealing film 111 of the release film-integrated sealing material 1 that has undergone the heat laminating step in this manner, the olefin-based resin forming the same layer exhibits sufficient molding properties, and the LED element 10 It adheres to the mounted wiring board 20 with good adhesion strength.

[Method of manufacturing self-luminous display]
The LED module 30 obtainable by the above manufacturing method is further laminated and integrated with the display surface panel 2 by adhesive bonding or the like, so that the micro LED display device 100 shown in FIG. Various kinds of self-luminous display bodies can be manufactured.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

  In a roll-to-roll production facility as shown in FIG. 7, a test production of the release film-integrated sealing material according to the present invention was performed by the above-described production method.

<Manufacture of release film integrated sealing material of Example>
(Sealing film)
The following resin composition for a sealing film was extruded at an extrusion temperature of 210 ° C., a take-off speed of 1.1 m / min, and a film thickness of 150 μm using a φ30 mm extruder and a film forming machine having a 200 mm wide T-die.

(Resin composition for sealing film)
With respect to 100 parts by mass of the following base resin, 5 parts by mass of additive resin 1 (weatherproof masterbatch) and 20 parts by mass of additive resin 2 (silane-modified polyethylene resin) were mixed. A sealing material composition for forming a sealing film of an integrated sealing material was obtained.
Base resin 1
: Metallocene linear low-density polyethylene resin (M-LLDPE) having a density of 0.901 g / cm ³ , a melting point of 93 ° C and an MFR at 190 ° C of 2.0 g / 10 minutes.
Additive resin 1 (weathering agent masterbatch)
: KEMISTAB62 (HALS): 0.6 parts by mass with respect to 100 parts by mass of a low-density polyethylene resin having a density of 0.919 g / cm ³ and an MFR at 190 ° C. of 3.5 g / 10 min. KEMISORB12 (UV absorber): 3.5 parts by mass. KEMISORB 79 (UV absorber): 0.6 parts by mass.
Additive resin 2 (silane-modified polyethylene resin)
: 95 parts by mass of a metallocene linear low-density polyethylene resin having a density of 0.898 g / cm ³ and an MFR of 3.5 g / 10 minutes, 5 parts by mass of vinyltrimethoxysilane and a radical generator (reaction A silane-modified polyethylene resin obtained by mixing 0.15 parts by mass of dicumyl peroxide as a catalyst), melting and kneading at 200 ° C. The density of the additional resin 2 is 0.901 g / cm ³ , and the MFR is 1.0 g / 10 minutes.

(Release film)
The following resin film for a release film was integrated by pressing the resin film constituting the release film with the sealing film that was melt-extruded as described above.
(Resin film for release film)
Polyethylene terephthalate (PET) film with a melting point of 260 ° C., thickness 50 μm. The wetting index of the surface of the resin film measured according to JIS K 6768 was 30 Dyne.

<Production of release film integrated sealing material of comparative example>
Except for using the following general-purpose release film that has been subjected to processing to enhance the release property as the resin film that constitutes the release film, the release film integrated type sealing of the comparative example was performed under the same conditions as in the example. Lumber was manufactured.

(General-purpose release film)
Polyethylene terephthalate (PET) film with a melting point of 260 ° C., thickness 50 μm. However, the surface is a "resin film that has been subjected to surface release treatment" that has been subjected to silicone release treatment. The wetting index of the surface of the resin film measured according to JIS K 6768 was 18 Dyne.

<Evaluation Example 1: Adhesion strength between films>
The adhesive strength (N) at the interface between the sealing film and the release film was determined by the following “adhesion test” (under the same conditions as the above-described adhesion test) for the release film-integrated sealing material of each of the example and the comparative example. / 15 mm). The results are shown in Table 1.
(Adhesion test)
In the release film-integrated sealing material cut to a width of 15 mm, the release film in close contact with the sealing film was vertically peeled (50 mm / min) with a peeling tester (Tensilon Universal Tester RTF-1150-H). ) A test is performed to measure the adhesion strength (N / 15 mm) at the interface between the two films.

<Evaluation Example 2: Easy handling before thermal lamination>
For the release film integrated sealing material of each of Examples and Comparative Examples, for ease of handling before thermal lamination, a work of manually placing each sealing material in a laminator was performed. The ease of handling before thermal lamination was evaluated organoleptically based on whether or not unnecessary delamination occurred. The work was separately performed by five workers, and the evaluation criteria were as follows. The evaluation results are shown in Table 1 as “easiness of handling”.
(Evaluation criteria)
A: In the process of the manual operation, peeling between the sealing film and the release film did not occur during the operation by any operator.
B: In the process of the manual work, peeling between the sealing film and the release film occurred during the work by one or less worker.
C: In the process of the manual work, peeling between the sealing film and the release film occurred during the work by two or more workers.

<Evaluation Example 3: Ease of peeling after thermal lamination>
The production of the LED module using the release film-integrated sealing material of the example by the existing laminator, the use of the above sealing film as the sealing material, and the above-mentioned “general-purpose release film” The production of an LED module that was used as a single release material without being integrated with the sealing film was experimentally performed by the above-mentioned [LED module production method]. As a result, regarding the releasability of the sealing material after the thermal lamination, there is no problem at all, and the sealing film (sealing material) can be “smoothly released” from the release film (release material). It was confirmed that it was possible.

  From the results of the test production of the above LED module, and the test and evaluation results in Table 1, the release film-integrated sealing material of the present invention shows that in the heat lamination step performed in the process of producing the self-luminous display, It can be seen that the loss of the smoothness of the surface of the sealing material caused by using the release film and the deterioration of the quality of the self-luminous display body caused by the loss can be avoided.

1 Release Film Integrated Sealing Material 111 Sealing Film (Sealant Body)
121 Release Film 122 Release Surface 123 Exposed Surface 10 LED Element 11 LED Light Emitting Chip 12 Resin Cover 20 Wiring Board 21 Support Substrate 22 Wiring Part 23 Solder Layer 30 LED Module for Self-Light Emitting Display 40 Laminator 41 Heating Plate 42 Heating Plate (Auxiliary heating plate)
43 Laminated body pressing plate 50 Roll-to-roll type production equipment 51 T die 52 First feed roll 53 Second feed roll 54 Discharge roll 541 Rubber roll 542 Emboss roll 543 Cooling roll 2 Display panel 100, 100A, 100B micro LED display (self-luminous display)

Claims (6)

A sealing material for a self-luminous display,
A sealing film and a release film, a multilayer film formed by laminating,
The sealing film has an olefin resin as a base resin,
The release film has a melting point of 220 ° C. or more and 270 ° C. or less,
A release film-integrated sealing material, wherein an adhesion strength at an interface between the sealing film and the release film measured by the following adhesion test is 0.3 N / 15 mm or more and 3.0 N / 15 mm or less.
Adhesion test: In a release film integrated sealing material cut to a width of 15 mm, the release film in close contact with the sealing film is vertically peeled by a peeling tester (Tensilon Universal Testing Machine RTF-1150-H). (50 mm / min) test is performed to measure the adhesion strength at the interface between both films.   2. The release film according to claim 1, wherein the release film has a wetting index according to JIS K 6768 of not less than 25 Dyne and not more than 35 Dyne on a surface of a release surface which is a surface on an interface side with the sealing film. 3. Body sealant.   The release film integrated sealing according to claim 1, wherein the release film has a release surface having a surface roughness Rz of 0.1 or more, which is a surface on the interface side with the sealing film. Wood. The release film is a polyethylene terephthalate resin film,
The polyethylene terephthalate resin film is a surface untreated polyethylene terephthalate resin film that has not been subjected to a surface processing treatment for adjusting adhesion and release properties, on a release surface that is a surface on the interface side with the sealing film. The release film-integrated sealing material according to any one of claims 1 to 3. Base resin of the sealing film, the density 0.870 g / cm ³ or more 0.930 g / cm ³ or less of the polyethylene resin, the release film-integrated sealing material according to any one of claims 1 to 4 . A release film integrated sealing material according to claim 1,
A light emitting module in which a plurality of light emitting elements are mounted on a wiring board;
Are laminated,
Comprising a heat lamination step of integrating by heating and pressing while placed on a heating plate made of metal and / or glass,
The heat compression bonding, the release film of the release film integrated sealing material constituting the laminate, without intervening another release film, directly placed on the heating plate and performed, LED module of Production method.

Images