JP2011221404A - Method for manufacturing flexible display module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a flexible display module capable of fully attaining protection from external environments by improving a seal performance.SOLUTION: A method for manufacturing the flexible display module 36 comprises steps of sandwiching a flexible display panel module 34 between two sheets 31 and 32 of which at least one is transparent, and thermally compressing and sealing the peripheral parts 35 of the two sheets. The peripheral parts of the two sheets are thermally compressed and sealed so that an electrode part 33 formed in the edge part of the flexible display panel module for connecting to a driver side is protruded out of a sealing part.

Description

  The present invention relates to a method of manufacturing a flexible display module that enables the flexible display module to be protected from an external environment (particularly humidity).

  Conventionally, as an example of a panel structure that is a precursor of a display, a display medium configured as a particle group including electrically drivable particles is disposed between two panel substrates at least one of which is transparent, 2. Description of the Related Art A panel structure that displays information by moving between panel substrates in accordance with an electric field generated between electrodes provided on each substrate is known. And in order to protect the panel structure mentioned above from an external environment, it was common to seal the peripheral part between two panel substrates with a sealing material (for example, refer patent document 1).

  FIGS. 8A to 8C are diagrams for explaining an example of a manufacturing method of a panel structure which is a precursor of a conventional display, and FIG. 8A is a panel in a charged particle gas moving system. FIG. 8B shows an example of a structure, FIG. 8B shows an example of a liquid crystal panel structure, and FIG. 8C shows an example of a microcapsule electrophoresis panel structure. In the example shown in FIG. 8A, 51 and 52 are panel substrates (at least one is transparent), 53W is a white display medium, 53B is a black display medium, 54 is a partition, and 55 and 56 are electrodes. In the example shown in FIG. 8B, 61 and 62 are panel substrates (at least one is transparent), 63 is a spacer, 64 is a liquid crystal, and 65 and 66 are electrodes. Further, in the example shown in FIG. 8C, 71 and 72 are panel substrates (at least one is transparent), 73 is a microcapsule filled with colored charged particles (not shown) and an insulating liquid 74, 75 , 76 are electrodes. In the examples shown in FIGS. 8A to 8C, the electrodes 55 (65, 75) and 56 (66, 76) are shown on the entire surface for easy understanding. Accordingly, various shapes such as a stripe shape, a solid surface shape, and a shape corresponding to a pixel are adopted.

  In addition to the above configuration, the panel structure body manufacturing method as a precursor of the conventional display shown in FIGS. 8A to 8C has two panel substrates 51 (61, 71) in any example. ) And 52 (62, 72) are sealed with a sealing material 81 to prevent the outside atmosphere and moisture from entering the panel structure. Conventionally, an FPC for connecting to the drive circuit side of the drive device is provided outside the sealing material of the panel structure to obtain a display module.

JP 2006-23557 A

  In the above-mentioned conventional display module, the performance required for the sealing material is diverse, such as adhesive strength, barrier properties, and the absence of substances that adversely affect the other components. It was difficult to prepare a sealing material that satisfies the above. In addition, the adhesion between the sealing material and the substrate, particularly the adhesion when electrodes are interposed, is not necessarily good, and it is difficult to improve the adhesion that leads to the improvement of the sealing performance in the conventional display module having the above-described configuration. It was. Therefore, it is difficult to prevent moisture or the like in the external atmosphere from entering the inside of the panel structure that is a precursor of the display, and the protection from the external environment at a high level required in recent years cannot be sufficiently achieved. There was a problem.

  This problem is prominent in displays with flexible structures using resin films instead of glass substrates (called flexible displays). Organic EL, electro-powder fluid (registered trademark), electrophoresis, cholesteric The same problem has arisen with electronic paper such as liquid crystal and viscotable nematic liquid crystal.

  An object of the present invention is to solve the above-mentioned problems and to provide a flexible display module manufacturing method capable of improving the sealing performance and sufficiently achieving protection from the external environment in a flexible display panel module. To do.

  The method for producing a flexible display module according to the present invention is a method for producing a flexible display module in which a flexible display panel module is sandwiched between two sheets, at least one of which is transparent, and the peripheral portions of the two sheets are thermocompression bonded and sealed. Then, the peripheral portion of the two sheets is thermocompression-bonded so that the electrode portion for connection to the driving device formed at the end portion of the flexible display panel module comes out of the seal portion. It is characterized by sealing.

  Moreover, as a suitable example of the manufacturing method of the flexible display module of this invention, after arrange | positioning an adhesive agent or an adhesive material on the electrode part for a connection to the drive device side used as a seal | sticker part, after said 2 sheets of sheet | seat Sealing the peripheral part by thermocompression bonding, sealing the peripheral part of the two sheets by thermocompression bonding, and then injecting a liquid moisture-proof insulating material from the outside of the sealing part of the connecting electrode part, Two sheets have a moisture barrier property, and the flexible display panel module seals a display medium configured as a particle group including a chargeable particle between two flexible substrates at least one of which is transparent. The display panel module may be a flexible display panel module that displays information by moving between flexible substrates with an electric field.

  According to the present invention, the peripheral part of the two sheets is thermocompression bonded so that the electrode part for connection to the driving device formed on the end part of the flexible display panel module comes out of the seal part. By sealing, in a flexible display panel module, it is possible to obtain a flexible display module manufacturing method that can sufficiently improve the sealing performance and sufficiently achieve protection from the external environment.

  Further, as a preferred example of the present invention, when an adhesive or a pressure-sensitive adhesive material is disposed on the connection electrode portion serving as a seal portion, two sheets are peripherally sealed by thermocompression bonding. After sealing the periphery of the sheet by thermocompression bonding, when a liquid moisture-proof insulating material is injected and placed from the outside of the sealing part of the connecting electrode part, and when the two sheets have moisture barrier properties, external Fuller protection from the environment can be achieved.

  Furthermore, as a preferred example of the present invention, a flexible display panel module seals a display medium configured as a group of particles containing chargeable particles between two flexible substrates, at least one of which is transparent, When the display panel module is a flexible display panel that displays information by moving an electric field with an electric field, the present invention can be applied more suitably.

(A), (b) is a figure which shows the structure of an example of the flexible display panel used as the object of this invention, respectively. (A), (b) is a figure which shows the structure of the other example of the flexible display panel used as the object of this invention, respectively. (A), (b) is a figure which shows the structure of the further another example of the flexible display panel used as the object of this invention, respectively. (A)-(c) is a figure for demonstrating an example of the structure of the flexible display module used as the object of this invention, respectively. (A), (b) is a figure for demonstrating an example of the sealing method of the sheet peripheral part in the manufacturing method of the flexible display module of this invention, respectively. (A)-(c) is a figure for demonstrating the other example of the sealing method of the sheet peripheral part in the manufacturing method of the flexible display module of this invention, respectively. (A), (b) is a figure for demonstrating an example of the flexible display module of this invention, respectively. (A)-(c) is a figure for demonstrating an example of the manufacturing method of the conventional flexible display module, respectively.

<About the structure of the flexible display panel which is the object of the manufacturing method of the present invention>
First, a basic configuration of a flexible display panel of a moving method in charged particle gas which is an example of a flexible display panel that is an object of the present invention will be described. In the flexible display panel, an electric field is applied from a counter electrode pair to a display medium configured as a particle group including a chargeable particle sealed between two opposing substrates. Along with the applied electric field direction, the display medium is attracted by an electric field force or a Coulomb force, and the moving direction of the display medium is switched by a change in the electric field direction, whereby information such as an image is displayed. Therefore, it is necessary to design the information display panel so that the display medium can move uniformly and maintain the stability when the display information is rewritten or when the displayed information is continuously displayed. Here, as the force applied to the particles constituting the display medium, in addition to the force attracting each other by the Coulomb force between the particles, an electric mirror image force between the electrode and the substrate, an intermolecular force, a liquid cross-linking force, gravity and the like can be considered.

  Examples of a flexible display panel of the charged particle movement system that is the subject of the present invention are based on FIGS. 1A, 1B, 2A, 2B, 3A, and 3B. explain.

  In the example shown in FIGS. 1A and 1B, at least two types of display media (in this case, including negatively charged white particles 3Wa) configured as a particle group including particles having at least optical reflectance and chargeability are included. The white display medium 3W configured as a particle group and the black display medium 3B configured as a particle group including positively charged black particles 3Ba are provided on the flexible panel substrate 1 in each cell formed by the partition walls 4. An electric field generated by applying a voltage between a pair of pixel electrodes formed by opposing and orthogonally intersecting the electrode 5 (stripe electrode) and the transparent electrode 6 (stripe electrode) provided on the transparent flexible panel substrate 2. Accordingly, the flexible panel substrates 1 and 2 are moved vertically. Then, the white display medium 3W is visually recognized by the observer as shown in FIG. 1A, or the white display is displayed by the observer, or the black display medium 3B is visually recognized by the observer as shown in FIG. Is displayed in a matrix with black and white dots. Here, 9 is an adhesive. In addition, in FIG. 1 (a), (b), the partition in front is abbreviate | omitted. Further, here, an example is shown in which cells and pixels (dots) have a one-to-one correspondence and are arranged in a matrix, but it is not always necessary to have a one-to-one correspondence.

  In the example shown in FIGS. 2 (a) and 2 (b), at least two types of display media (here, including negatively charged white particles 3Wa) configured as a particle group including particles having at least optical reflectance and chargeability are included. The white display medium 3W configured as a particle group and the black display medium 3B configured as a particle group including positively charged black particles 3Ba are provided on the flexible panel substrate 1 in each cell formed by the partition walls 4. Flexible panel substrate according to an electric field generated by applying a voltage between the electrode 5 (pixel electrode with TFT (thin film transistor)) and the transparent electrode 6 (common electrode) provided on the transparent flexible panel substrate 2 Move vertically to 1 and 2. Then, the white display medium 3W is visually recognized by the observer as shown in FIG. 2A, or the white display is displayed by the observer, or the black display medium 3B is visually recognized by the observer as shown in FIG. Is displayed in a matrix with black and white dots. Here, 9 is an adhesive. In addition, in FIG. 2 (a), (b), the partition in front is abbreviate | omitted. Further, here, an example is shown in which cells and pixels (dots) have a one-to-one correspondence and are arranged in a matrix, but it is not always necessary to have a one-to-one correspondence.

  Further, in the above-described example, the example of the display panel of the charged particle gas moving system in which the cell space is filled with gas (for example, air) has been described, but instead of gas, a vacuum or an insulating liquid is used. It is also possible to use a charged particle liquid moving system (electrophoresis system). In this case, as shown in FIGS. 3 (a) and 3 (b), a group of particles containing the chargeable particles is sealed as a display medium 3W, 3B in a microcapsule 8 together with a transparent insulating liquid 7 to form a cell. It is also possible to provide a display panel using a moving method (electrophoresis method) in a charged particle liquid in which the partition walls 4 are not provided. Furthermore, it goes without saying that the present invention can also be suitably used for a liquid crystal flexible display panel shown in FIG.

<About the specific example of the manufacturing method of the flexible display module of this invention>
The flexible display module manufacturing method of the present invention is characterized by using the flexible display panel described above as an example and, for example, a flexible printed circuit board (FPC) serving as an electrode part for connection to the drive device side. ) Is mounted between two sheets of which at least one is transparent, and the periphery of the two sheets is sealed by thermocompression bonding, the connection electrode section is sealed It seals so that it may come out of a part, and it is in the point which protects a flexible display panel from an external environment while enabling the connection with the drive device side.

  Hereinafter, for specific examples of the sealing method in the method of manufacturing the flexible display module of the present invention, refer to FIGS. 4 (a) to (c), FIGS. 5 (a) and 5 (b), and FIGS. 6 (a) to (c). To explain.

  Fig.4 (a) is a figure for demonstrating an example of the manufacturing method of the flexible display module of this invention. 4A to 4C, the two transparent resin sheets 31 and 32 are both polyethylene terephthalate sheets (PET sheets). Further, PET sheets 31 and 32 are arranged on both sides of a display panel on which a flexible printed circuit board (FPC) 33 that is sealed with a sealing material 39 and is used as an electrode part for connection to the driving device side is mounted, The peripheral portions 35 of the PET sheets 31 and 32 are sealed by thermocompression bonding. The pressure-bonding member temperature of the thermocompression bonding apparatus is set higher than the softening temperature of PET, and the PET sheets 31 and 32 are melted and pressed against each other for sealing. In this case, there is a solution-like insulating material (for example, a moisture-proof material “Tuffy” manufactured by Hitachi Chemical Co., Ltd.) in a gap that becomes an interface between the flexible printed circuit board (FPC) 33 and the PET sheets 31 and 32. It is preferable to solidify by injecting, since a sufficient sealing property can be obtained. In the example shown in FIG. 4A, the driver IC 40 mounted on the flexible printed circuit board (FPC) 33 is located outside the peripheral portion 35 that is thermocompression bonded.

  4 (b) and 4 (c) are diagrams for connecting the extended portions of the stripe electrodes 5 and 6 to the drive circuit side in place of the flexible printed circuit board (FPC) 33 in the example shown in FIG. 4 (a). The electrode portion is the same as the example shown in FIG. In the example shown in FIG. 4B, the extended portion of the stripe electrode 6 on the observation side is an electrode portion for connection to the drive circuit side, and in the example shown in FIG. 4C, the extension of the stripe electrode 5 on the back side. This portion is used as an electrode portion for connection to the drive circuit side.

  In the example shown in FIGS. 4A to 4C, the flexible display module manufacturing method of the present invention is characterized in that, for example, a flexible display panel module 21 is sandwiched between resin sheets 31 and 32 and two sheets of resin are sandwiched. The flexible display panel module 21 is protected from the external environment by sealing the peripheral portions 35 of the sheets 31 and 32 by thermocompression. In the example shown in FIGS. 4A to 4C, even if the problem of poor adhesion between the sealing material and the panel substrate remains in the above-described conventional flexible display module, the problem is further solved with a resin sheet on the outside. It does not occur because of the sealed structure. Moreover, since the same material can be used for the two resin sheets, good sealing can be performed by thermocompression bonding. As a result, moisture permeation from the end of the flexible display module can be prevented, and a flexible display module that can sufficiently achieve protection from the external environment by improving the sealing performance can be obtained.

  In addition, the above-mentioned various performances required for the sealing material are shared. For example, the performance that does not cause adverse effects due to substance transfer to the sealing material (for example, electrode migration and display element contamination) and adhesive force are shared, and barrier properties Since the two resin sheets share, the flexible display module can be easily manufactured by increasing the degree of freedom in designing the sealing material. Furthermore, it goes without saying that the barrier property of the resin-made flexible substrate itself is inferior to the barrier property of the glass substrate itself, but by adding two resin sheets, at least the water movement distance is increased and the water content is reduced to the panel. You can earn a distance to reach the inside. Further, if the resin sheet has a barrier function, the reliability further increases.

  5 (a), 5 (b) and 6 (a) to 6 (c) respectively show flexible printed circuit boards (electrodes for connection to the drive device side) in the method for manufacturing a flexible display module of the present invention. For the flexible display panel module 34 on which the FPC) 33 is mounted, a transparent resin sheet 31 is disposed on the observation side, and a resin sheet 32 that does not need to be transparent is disposed on the back side. It is a figure for demonstrating an example of the method of carrying out the thermocompression bonding of the peripheral part 35 of the sheet of resin sheets 31 and 32, and sealing. 5 (a) and 5 (b) show an outline of a cross section of the flexible display module 36, and FIGS. 6 (a) to 6 (c) show a flexible printed circuit board as an electrode portion for connection to the drive device side. A state in which a cross section of a portion where (FPC) 33 is mounted is enlarged is shown.

  5A and 5B, the two resin sheets 31 and 32 are both polyethylene terephthalate sheets (PET sheets). In addition, silicon oxide SiOx films 37 and 38 for improving moisture resistance (barrier properties) are provided on the outer sides of the resin sheets 31 and 32, respectively. PET sheets 31 and 32 are disposed on both sides of a display panel on which a flexible printed circuit board (FPC) 33 that is sealed with a sealing material 39 and is used as an electrode part for connection to the driving device side is mounted. The peripheral portions 35 of 31 and 32 are sealed by thermocompression bonding. The pressure-bonding member temperature of the thermocompression bonding apparatus is set higher than the softening temperature of PET, and the PET sheets 31 and 32 are melted and pressed against each other for sealing. In this case, an adhesive material or an adhesive material is arranged in advance at the interface with the flexible printed circuit boards (FPC) 31 and 32, or a liquid insulating material (for example, manufactured by Hitachi Chemical Co., Ltd.) In particular, it is preferable to solidify by injecting a moisture-proof material such as “tuffy”.

  The resin sheets 31 and 32 are preferably made of a material having a relatively low softening temperature because the temperature during thermocompression bonding can be lowered. The materials for the resin sheets 31 and 32 include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyimide (PI), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyethylene. A thermoplastic resin that can be formed into a sheet (preferably as thin as a film) such as (PE), polybutylene terephthalate (PBT), and polypropylene (PP) is desirable. If the two resin sheets 31 and 32 are made of the same resin material, both can be softened at the same temperature, so that thermocompression bonding is facilitated. In the case of different resin materials, thermocompression bonding is performed at the softening temperature of the resin having the higher softening temperature. 5A and 5B show the case where the driver IC 40 mounted on the flexible printed circuit board (FPC) 33 is inside the seal portion, but it may be outside the seal portion. Further, the SiOx films 37 and 38 may not be used. Furthermore, in order to improve barrier properties, it is also possible to use a sheet obtained by laminating a plurality of sheets of different materials selected from the above resin sheets, regardless of the same type or different types, by the wet method or the dry method on the surface, By using a multilayer sheet obtained by laminating a sheet in which at least one thin film layer of metal or oxide is coated between resin sheets, the barrier property can be improved and the reliability can be greatly improved.

  6A to 6C show a state after sealing of a portion where a flexible printed circuit board (FPC) 33 for connection to a drive circuit of the drive device is mounted. An adhesive 41 (here, a thermosetting adhesive is used) is placed on the surface of the PET sheet 31 or 32 corresponding to the flexible printed circuit board (FPC) 33 (FIG. 6A), The pressure-bonding member temperature of the thermocompression bonding apparatus is set to be higher than the softening temperature of PET to soften the PET sheet surface and press-fit each other for sealing (FIG. 6B). Thereafter, a liquid insulating material (moisture-proof material) 42 is injected and disposed between the sheet 31 and the FPC 33 and between the sheet 32 and the FPC 33 (FIG. 6C). Thus, sufficient sealing can be performed even at the position where the flexible printed circuit board (FPC) 33 is mounted. As the adhesive 41, a hot-melt type can be applied in addition to the thermosetting type. Further, an adhesive material can be applied instead of an adhesive.

  7A and 7B are diagrams for explaining an example of the method for manufacturing the flexible display module of the present invention. In the example shown in FIGS. 7A and 7B, the stripe electrodes 6 formed on the information display screen area of the panel substrate 31 on the observation side of the flexible display panel module 34 that is a precursor of the flexible display module 36 are used. A flexible printed circuit board (FPC) 33-1 for connection to the drive circuit of the drive device is mounted on the lead-out wiring terminal, and is drawn out from the stripe electrode 5 formed in the information display screen area of the panel substrate 32 on the back side. A method of sealing a flexible display panel module 34 having a flexible printed circuit board (FPC) 33-2 mounted on a wiring terminal to connect to a drive circuit of a drive device with two PET sheets 31 and 32 is shown. Yes.

  As the flexible printed circuit board (FPC) 33, a commercially available one can be used, such as a TCP (Tape Carrier Package) mounted with a driver IC 40 or a flexible cable having a structure in which a wiring electrode is covered. Here, the sealing position on the flexible printed circuit board (FPC) 33 is set to the inside of the driver IC 40, and the driver IC 40 is outside the seal. However, the driver IC 40 is sealed by sealing the outside of the driver IC 40. It may be within the structure.

  At this time, in the method of sealing by thermocompression bonding, when the base material of the flexible printed circuit board and the material of the two resin sheets 31 and 32 are the same material, the FPC portion has high sealing performance by thermocompression bonding. Sealing is possible, and sufficient sealing can be performed by one thermocompression bonding operation. If the materials are not the same, the resin sheet material and the flexible printed circuit board material may be insufficiently sealed only at the position where the flexible printed circuit board (FPC) 33 is mounted. The liquid insulating material 42 is disposed at the interface between the flexible printed circuit board (FPC) 33 and the flexible printed circuit board (FPC) 33, or corresponds to the flexible printed circuit board (FPC) 33 of the resin sheets 31 and 32. Sealing can be reliably performed by the above-described method in which an adhesive or a pressure-sensitive adhesive material is disposed on the surface of the flexible printed circuit board (FPC) 33 or the surface of the flexible printed circuit board (FPC) 33.

  Note that it is preferable to provide a moisture barrier film (SiOx film) on one surface of the resin sheet that is not opposed to each other because the moisture barrier performance of the display module is increased. Examples of the moisture barrier film include a wet-processed or dry-processed silicon oxide compound (SiOx) single-layer structure film, multilayer structure film, and multilayer structure film containing polyvinylidene chloride (PVDC). These structure films having moisture barrier properties need not be on the thermocompression-bonding surface, and a higher barrier effect can be obtained by forming a multilayer resin sheet structure in which the moisture barrier films are laminated. If this moisture barrier film is on the thermocompression bonding surface, the sealing performance is impaired. Therefore, it is important not to dispose this moisture barrier film on the thermocompression bonding surface. When thermocompression bonding is performed on the surface where the wiring electrode of the flexible cable is exposed, the sealing performance is impaired even in thermocompression bonding between the metal film used as the electrode or a metal oxide film such as ITO and the resin sheet. When it is exposed, it is preferable to perform a treatment for improving the adhesion such as a discharge treatment such as a corona treatment or a chemical treatment such as an acid treatment or laminating an adhesive thin film on the HPC surface.

  Display modules to which the present invention is applied include notebook computers, electronic notebooks, portable information devices called PDA (Personal Digital Assistants), mobile devices such as mobile phones and handy terminals, electronic papers such as electronic books and electronic newspapers, Billboards such as signboards, posters, blackboards (whiteboards), electronic desk calculators, home appliances, automobile supplies, point cards, IC cards, electronic advertisements, information boards, electronic POPs (Point Of Presence, Point Of Purchase advertising), electronic price tags, electronic shelf labels, electronic musical scores, RF-ID devices, as well as various electronic devices such as POS terminals, car navigation devices, watches, or connected to external rewriting means Suitable for use as a rewritable paper that rewrites the display using external rewriting means such as a touch pen. I can.

DESCRIPTION OF SYMBOLS 1, 2 Substrate 3W White display medium 3Wa Chargeable white particle 3B Black display medium 3Ba Chargeable black particle 4 Partition 5, 6 Electrode 7 Insulating liquid 8 Microcapsule 9 Adhesive 21, 34 Display panel module 31, 32 Resin sheet 33 , 33-1 and 33-2 Flexible Printed Circuit Board (FPC)
35 Peripheral part 36 Flexible display module 37, 38 SiOx film 39 Sealing material 40 Driver IC
41 Adhesive 42 Insulation

Claims (5)

  A method of manufacturing a flexible display module, wherein a flexible display panel module is sandwiched between two sheets, at least one of which is transparent, and the peripheral portions of the two sheets are sealed by thermocompression bonding. The flexible display module is characterized in that the peripheral portion of the two sheets is sealed by thermocompression bonding so that the electrode portion for connection to the driving device side is formed outside the seal portion. Manufacturing method.   2. The flexible device according to claim 1, wherein an adhesive or an adhesive material is disposed on the connecting electrode portion serving as the seal portion, and then the peripheral portions of the two sheets are thermocompression-bonded and sealed. Display module manufacturing method.   2. The flexible display according to claim 1, wherein after the peripheral portions of the two sheets are sealed by thermocompression bonding, a liquid moisture-proof insulating material is injected and arranged from the outside of the sealing portion of the connecting electrode portion. Module manufacturing method.   The method for manufacturing a flexible display module according to claim 1, wherein the two sheets have moisture barrier properties.   The flexible display panel module is configured to seal a display medium configured as a particle group including charged particles between two flexible substrates, at least one of which is transparent, and move information between the flexible substrates by an electric field. It is a flexible display panel module to display, The manufacturing method of the flexible display module of any one of Claims 1-4 characterized by the above-mentioned.

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