JP3200957B2 - Manufacturing method of electrophoretic display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device using electrophoretic particles, in which one flexible electrode plate made of a resin film or the like and a display dispersion system are divided into discrete sections into discontinuous phases. And a rigid electrode plate on which a porous spacer is provided to easily and reliably disperse the dispersion in each hole of the porous spacer without giving damage to the dispersion and components due to high heat or high pressure. The present invention relates to a method of manufacturing a dispersion-divided electrophoretic display device suitable as a means for enclosing the electrophoretic display device.

[0002]

2. Description of the Related Art As shown in FIG. 7, an electrophoretic display device of this type using electrophoretic particles has a required display electrode pattern using an appropriate transparent conductive member such as indium tin oxide on the opposing surfaces. Two electrode plates 1, 3 formed separately from each other
And a porous spacer 8 for enclosing a dispersion system 7 in which electrophoretic particles 6 are dispersed in a liquid dispersion medium between the opposing gaps, and a hot melt adhesive 5 as a sealing member around the porous spacer 8. It is equipped with a structure.

Such an electrophoretic display device changes the distribution state of the electrophoretic particles 6 by applying an electric field to the dispersion system 7 so that the electrophoretic particles 6 can be adsorbed and separated from the electrode patterns 2 and 4. This is to change the optical characteristics of the dispersion system 7 to perform a desired display operation of characters, symbols, figures, and the like. An electrophoretic display having such a structure is known, for example, from Japanese Patent Application Laid-Open No. 2-223936.

[0004]

In such an electrophoretic display device, a certain amount of pressure and heat are required to sufficiently adhere the flexible electrode plate and the hot melt adhesive.
However, the hot melt adhesive 5 disposed around the porous spacer 8 while pushing out the excess dispersion system 7 by applying a pressing force to the upper surface of the flexible electrode plate with a heated metal roller or the like.
When thermocompression bonding is performed between the flexible electrode plate and the flexible electrode plate, the display dispersing system 7 is also heated to a temperature equivalent to the melting point of the hot melt adhesive 5. give.

When a pressure high enough to extrude the dispersion system 7 from the interface between the hot melt adhesive 5 and the flexible electrode plate is applied, the pores of the porous spacers 8 are depressurized by releasing the pressure. In addition, a foaming phenomenon that lowers the display performance also occurs.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a thermocompression-bonding type or the like for producing an electrophoretic display device of this type only in a portion where a hot melt adhesive which requires high heat and high pressure bonding is provided. By applying heat treatment intensively using, it is possible to stably and surely enclose the display dispersion system between the two electrode plates without applying undesired heat or pressure to the display dispersion system and the constituent members. It provides a novel manufacturing method for making possible electrophoretic displays.

Therefore, in the present invention, at least one of the porous spacers having a large number of through holes for discontinuously dividing the display dispersion system and having a hot melt adhesive provided on the outer periphery thereof is provided. The two electrode plates are disposed between a pair of transparent counter electrode plates, and the two electrode plates are bonded to each other by using a thermocompression bonding die for heat-sealing the hot melt adhesive.

[0008] Such a thermocompression-bonding type may be one which has been heated to a required temperature in advance, or may be configured to receive a required heat from a hot press. It is also possible.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to one embodiment shown in the drawings. FIG. 1 is a conceptual cross-sectional configuration diagram of an electrophoretic display device manufactured according to an embodiment of the present invention, and 1 is a transparent glass plate as a base material for forming a transparent rigid electrode plate. There is indium oxide
The required electrode pattern 2 is appropriately formed using a transparent conductive material such as tin.

On the upper surface of the rigid electrode plate, there is provided a porous spacer 8 for dividing and enclosing the dispersion system 7 into small sections. The porous spacer 8 is provided with a required through-hole by means of a punch or a laser or the like in a sheet-like material made of a synthetic rubber or natural rubber material such as silicon rubber, urethane rubber, fluorine rubber or acrylic rubber. A large number of perforations are integrally provided on the side of the rigid electrode plate on which the electrode pattern 2 is formed, or a photosensitive resin is applied on the electrode pattern 2 to form a chemical solution such as etching. The required through-holes can be arbitrarily formed by means.

As shown in FIG. 2, the porous spacer 8 has a large number of through holes 8 formed in the above-described manner for separately enclosing the dispersion system 7.
In addition to A, a hot melt adhesive 9 is provided around the end of the porous spacer 8 in relation to a flexible electrode plate described later.

On the upper surface of the porous spacer 8, a flexible electrode plate made of a flexible substrate 3 having another electrode pattern 4 formed on the surface corresponding to the electrode pattern 2 is provided. Is arranged. A dispersion system 7 is sealed in each of the holes 8A of the porous spacer 8 tightly held between the rigid electrode plate and the flexible electrode plate, and finally, the outer peripheral end of the display device as shown in FIG. The constituent members are joined to each other by the fixing adhesive 10 provided in the region, so that the electrophoretic display device 11 can be formed.

Here, each hole 8A of the porous spacer 8 is used.
As a method for enclosing the dispersion system 7 in the first step, as shown in FIG. 3, first, the dispersion system 7 excessively supplied to each hole 8A of the porous spacer 8 is pressurized from the upper surface of the flexible electrode plate. The excess dispersion system 7 is sequentially extruded while pressing the porous spacer 8 under the action of 12 to compress the porous spacer 8, whereby the dispersion system 7 having no pores or the like in each hole 8 A of the porous spacer 8 is formed. Complete encapsulation processing can be performed.

As the pressure member 12, at least one of a gas, a liquid and a solid can be used as appropriate. In the illustrated case, a steel roll is used.

The flexible electrode plate which is temporarily brought into close contact with the porous spacer 8 using such a pressing member 12 is provided on the outer peripheral area of the porous spacer 8 as shown in FIG. Only the hot-melt adhesive 9 is thermally fused by a frame-shaped thermocompression die 13 as shown in the figure corresponding to the arrangement of the hot-melt adhesive 9.

At this time, as shown in FIG. 5, the thermocompression bonding mold 13 performs heat fusion bonding with the flexible electrode plate in a state where it is heated to the hot melt melting point in advance or as shown in FIG. As described above, by transmitting the heat of at least one of the hot presses 14 and 15 to the thermocompression bonding die 13, the electrophoretic display device 11 and the thermocompression bonding die 13 sandwiched between the hot presses 14 and 15 are used as described above. Similarly, the hot-melt adhesive 9 is melted quickly and reliably between the flexible electrode plate and the outer peripheral region of the porous spacer 8 without adversely affecting the dispersion system 7 and other components while hot-melting the hot-melt adhesive 9. It is possible to perform a joining process.

It should be noted that the thermocompression bonding mold 13 can be configured to have a self-heating function by incorporating a heating heater or the like. Further, if necessary, the electrophoretic display device 1 in which a cushion material such as a rubber sheet is temporarily adhered to the thermocompression bonding mold 13.
1 can also be interposed.

Here, an example in which the conventional manufacturing method in the electrophoretic display device is compared with the manufacturing method of the present invention will be described below.

(Conventional Manufacturing Method) As shown in FIG.
When a steel roll is used as 2, the temperature of the roll should be 1.
As a result of joining the flexible electrode plate to the hot melt adhesive 9 of the porous spacer 8 at a temperature of 27 ° C. and an adhesive pressure of 25 kgf / cm ² , the adhesive strength was necessary and sufficient, but bubbles were 16 Occurred in places.

Further, when a predetermined temperature and pressure are applied to obtain a necessary adhesive strength between the hot melt adhesive and the transparent glass plate and the flexible electrode plate, after the pressure is released, the pores are released. The pores of the sex spacer were depressurized and bubbles were partially generated. Since the degree of pressure reduction in such holes depends on the amount of elastic deformation of the flexible electrode plate, if the processing is performed by reducing the pressure during pressurization in order to suppress such deformation, in that case, Due to insufficient extrusion of the dispersion between the hot melt adhesive and the electrode plates, the dispersion remained at the interface between the hot melt adhesive and the electrode plates, resulting in only partial adhesion.

(Manufacturing method of the present invention) After the flexible electrode plate was temporarily bonded under the same conditions of setting the roll temperature at 115 ° C. and the bonding pressure at 8 kgf / cm ² , as shown in FIG. As a result of heat fusion bonding under the conditions of a temperature of 130 ° C. and a pressure of 30 kgf / cm ² of the crimping die 13, the adhesive strength was sufficient and no bubbles were generated.

[0022]

According to the method of manufacturing an electrophoretic display device according to the present invention, the porous space is preferably used while suitably using a thermocompression bonding type.
By encapsulating the dispersion between the rigid electrode plate and the flexible electrode plate through the heat sink, it is possible to preferably prevent a situation in which bubbles are generated in the dispersion system without adversely affecting the dispersion and the components. .

Further, after thermocompression bonding using a thermocompression bonding type, there is no residual dispersion at the interface between the hot melt adhesive and the electrode plate, and therefore, the electrophoresis has a strong adhesion of the constituent members and good reliability. The display device can be manufactured stably and reliably.

[Brief description of the drawings]

FIG. 1 is a conceptual cross-sectional configuration diagram of an electrophoretic display device manufactured according to an embodiment of the method of the present invention.

FIG. 2 is a conceptual partial enlarged configuration diagram of a porous spacer used in the present invention.

FIG. 3 is a diagram illustrating an embodiment in which a flexible electrode plate is temporarily adhered to a porous spacer according to the present invention.

FIG. 4 is a diagram showing a porous space using a thermocompression bonding type according to the present invention.
The figure explaining the aspect which finally joins a flexible electrode plate and a support.

FIG. 5 is an explanatory view similar to FIG. 4 in a case where a thermocompression bonding type preheated to a required temperature is used.

FIG. 6 is an explanatory view showing an embodiment in which a porous spacer and a flexible electrode plate are joined in the same manner as described above by using a hot press and a thermocompression bonding type together.

FIG. 7 is a conceptual cross-sectional configuration diagram of an electrophoretic display device manufactured according to a conventional method.

[Explanation of symbols]

1 Transparent glass plate 8 Porous space
2 Electrode pattern 9 Hot melt adhesive 3 Flexible base material 10 Fixing adhesive 4 Electrode pattern 11 Electrophoretic display device 5 Hot melt adhesive 12 Pressurizing member 6 Electrophoretic particles 13 Thermocompression type 7 Dispersion system 15 hot press

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Tadakuma 757 Tenhoki, Kusazaki-cho, Inashiki-gun, Ibaraki Pref. Japan Inside the Minami-Ibaraki Plant of Mektron Co., Ltd. (56) References JP-A-2-223936 (JP, A) (58) Fields studied (Int. Cl. ⁷ , DB name) G02F 1/167

Claims (4)

(57) [Claims] 1. A dispersion system containing electrophoretic particles is sealed between a pair of transparent electrode plates, at least one of which is transparent, and the electricity in the dispersion system is controlled by a display control voltage applied between the electrode plates. In the case of manufacturing an electrophoretic display device for performing a required display operation by changing the optical reflection characteristic by changing the distribution state of the migrating particles, a large number of transmission lines for dividing the dispersion system discontinuously are required. A porous spacer having a hole and provided with a hot-melt adhesive on the outer periphery thereof is provided between the two electrode plates, and a thermo-compression die for heat-sealing the hot-melt adhesive is used. A method of manufacturing an electrophoretic display device, wherein the two electrode plates are bonded to each other. 2. The method for manufacturing an electrophoretic display device according to claim 1, wherein the thermocompression bonding type is a device which has been heated to a predetermined temperature in advance. 3. The method for manufacturing an electrophoretic display device according to claim 1, wherein the thermocompression bonding die receives required heat from a hot press. 4. The method for manufacturing an electrophoretic display device according to claim 1, wherein the thermocompression bonding type has a function of generating heat.