JP4148171B2 - Display panel bonding device - Google Patents

Description

  The present invention relates to a display panel laminating apparatus for laminating two light-transmitting substrates with a photocurable sealing agent in an assembly process of a display panel such as a liquid crystal panel.

  Usually, the liquid crystal screen is composed of a liquid crystal panel, a driver for controlling the liquid crystal panel, and a backlight for illuminating the liquid crystal panel from the back surface. The liquid crystal panel encloses liquid crystal and controls the voltage applied to the liquid crystal panel, thereby transmitting or blocking light from the backlight to display a screen.

FIG. 3 is a cross-sectional view showing an example of a liquid crystal panel (color liquid crystal panel).
In the figure, 101 is a color filter substrate, 102 is a TFT substrate, 103 is a color filter, 104 is a black matrix, 105 is a transparent electrode, 106 is an alignment film, 107 is a liquid crystal layer, 108 is a TFT element (thin film transistor), 109 is It is a sealing agent. In the figure, for easy understanding, the vertical direction is shown to be extremely enlarged compared to the horizontal direction, and the interval between the color filter substrate 101 and the TFT substrate 102 is actually about 5 μm.

  The liquid crystal panel is basically composed of two light-transmitting substrates (usually made of a glass substrate), a TFT substrate 102 on the opposite side (back side) of the color filter substrate 101 on the image viewing side (front side). In some cases, it is made of a resin substrate. On the color filter substrate 101, a light shielding film called a black matrix 104, a color filter 103, and the like are formed. The TFT substrate 102 is formed with driving elements for driving liquid crystal, for example, TFT elements 108 and liquid crystal driving electrodes formed of a transparent conductive film, and wirings connecting them. The black matrix 104 is formed of, for example, a chromium vapor deposition film or a black resin, and light from the backlight leaks from a portion not related to image display or a portion other than the liquid crystal, for example, the TFT element 108 or the wiring portion. Plays a blindfold so as not to disturb the image.

  In the manufacturing process of the liquid crystal panel as described above, in recent years, a manufacturing method called a drop method (One Drop Fill, abbreviated as ODF) has been adopted. The dropping method is disclosed in, for example, JP-A-9-73096.

  Below, the process of a dripping construction method is demonstrated using FIG. First, the TFT substrate 102 and the color filter substrate 103 are separately formed from two glass substrates (also called mother glasses). A TFT element 108 and a liquid crystal drive electrode are formed on the TFT substrate 102, and a black matrix 104 and a color filter 103 are formed on the color filter substrate 101. A sealant 109, which is an ultraviolet curable resin, is used on one of the glass substrate of the TFT substrate 102 or the color filter substrate 101 to enclose (hereinafter referred to as an outline. This area becomes a so-called liquid crystal screen. ) Are formed. The width of the sealing agent 109 is about 1 to 1.5 mm. Liquid crystal is dropped into the enclosure. The dropped liquid crystal spreads and accumulates in an enclosure (picture box).

  The other glass substrate is placed on one substrate on which the outline is formed in this way, and the sealing agent 109 is irradiated with ultraviolet rays through the glass substrate. As a result, the sealing agent 109 is cured, and the two glass substrates 101 and 102 are bonded (bonded). The sealing agent 109 serves as sealing of the liquid crystal layer 107 and adhesion of the two glass substrates 101 and 102. Although not shown, spherical fine particles called spacers are sprayed or a spacer is included in the sealant 109 in order to secure a gap between the two glass substrates 101 and 102. After bonding, the substrate is divided (cut) for each outline and incorporated as a display screen of a personal computer, a television, or the like.

FIG. 4 is a view showing a liquid crystal panel in which two glass substrates 101 and 102 are bonded together.
As shown in the figure, a liquid crystal panel formed by sandwiching a sealant between two glass substrates 101 and 102 has a plurality of (four faces in the figure) contours. A sealant is applied so as to surround each outline, and a black matrix 104 is formed so as to cover the sealant. In the figure, in order to avoid complication, only the black matrix 104 formed on the sealant is shown.

FIG. 5 is an enlarged cross-sectional view showing the structure in the vicinity of the sealant 109 of the liquid crystal panel shown in FIG.
As shown in the figure, the sealant 109 is under the black matrix 104 with a width of about 500 μm to 1 mm. Therefore, even if light irradiation is performed from the substrate side on which the black matrix 104 is formed, the sealant 109 becomes a shadow of the black matrix 104 and a portion that cannot be cured remains. However, there are cases in which it is required to perform bonding by irradiating light from the color filter substrate 101 side on which the black matrix 104 is formed, due to process reasons.

The following two cases are known as prior arts for bonding a liquid crystal panel by irradiating light from the substrate side on which such a black matrix is formed. These include a panel for bonding. It has been proposed to arrange a light reflecting member at a position facing the light irradiating unit and use the reflected light therefrom.
In Japanese Patent No. 28828403, light transmitted through a substrate to be bonded is reflected by a light reflecting member disposed at a position facing the light irradiation unit with the liquid crystal panel interposed therebetween, and the reflected light is sealed from the opposite side of the black matrix. It is cured by being irradiated.
Japanese Patent Laid-Open No. 2003-207790 inclines the light irradiation part, irradiates the liquid crystal panel with light from an oblique direction, cures the sealant in the shadow of the black matrix, and holds the light across the liquid crystal panel. The sealing agent is cured by using reflected light from a light reflecting member disposed at a position facing the irradiation unit.

Patent No. 28828403 JP 2003-207790 A

  However, as shown in the above publication, if the reflected light from the light reflecting member arranged at the position facing the light irradiating part across the liquid crystal panel is used, the sealant in the shadow portion of the black matrix is efficiently used. Although it can be cured well, there are the following problems.

FIG. 6 is a diagram for explaining the problem of the sealing agent curing method as described in the above publication.
As shown in the figure, when the light reflected from the light reflecting surface is applied to the sealant 109 under the black matrix 104, the reflected light is applied to the liquid crystal layer 107 if the distance between the light reflecting surface and the liquid crystal panel is narrow. It does not reach the seal agent 109 in the near back. On the other hand, if the interval is wide, the reflected light passes through the sealing agent 109 having a width of 1 to 1.5 mm, and the liquid crystal layer 107 is irradiated with light. When the liquid crystal layer 107 and the alignment film 106 are irradiated with strong ultraviolet rays, characteristic changes may occur. Therefore, it is desirable to reduce the ultraviolet rays as much as possible.

Therefore, it is necessary to hold the liquid crystal panel within a certain range with respect to the light reflecting surface so that the reflected light from the light reflecting surface is appropriately irradiated to the sealing agent 109. It is necessary to provide an interval setting means between the reflecting member and the liquid crystal panel. It should be noted that this interval setting means has the following points.
(1) A display panel bonding apparatus needs to cope with various types of display panel bonding processes with different outline sizes. That is, the size and shape of the contour formed on the liquid crystal panel to be processed vary. When the size or shape of the contour changes, the position of the sealing agent also changes. Therefore, even if the position of the sealing agent changes, the interval setting unit needs to prevent the reflected light from the light reflecting surface from entering the sealing agent.
(2) The liquid crystal panel to be bonded has a size of 1 m square or more and is increasing year by year. On the other hand, since the two glass substrates to be bonded together are thin, simply supporting the four corners or the four sides causes bending due to their own weight, and the distance from the panel lower surface to the light reflecting member cannot be kept constant. Therefore, it is necessary to provide the interval setting means also in the region where the outline is formed.

  In view of the above-described problems, the object of the present invention is to provide (1) the size and shape of an image between a display panel to be bonded and a light reflecting member disposed at a position facing the display panel. Even if the position of the sealant changes due to the change in the distance, the gap setting means satisfying the following conditions: (2) the liquid crystal panel can be held so as not to disturb the reflected light incident on the sealant Another object is to provide a display panel bonding apparatus.

The present invention employs the following means in order to solve the above problems.
A first means is a display in which a light-shielding portion is formed on one of two light-transmitting substrates, and an ultraviolet curable sealant and a liquid crystal are sandwiched between the two light-transmitting substrates to form an integral shape. In the display panel laminating apparatus in which the panel is irradiated with ultraviolet rays from the side where the light-shielding portion is formed, the ultraviolet curable sealant is cured, and the two light-transmitting substrates are bonded together. A display panel laminating apparatus comprising: a stage comprising a light reflecting surface; and the display panel is placed on the stage via a light transmissive spacer.

  The second means is a liquid crystal in which a light-shielding portion is formed on one of the two light-transmitting substrates, and an ultraviolet curable sealant and a liquid crystal are sandwiched between the two light-transmitting substrates to form an integral shape. In a display panel laminating apparatus that irradiates the panel with ultraviolet rays from the side where the light shielding portion is formed, cures the ultraviolet curable sealant, and bonds the two light transmissive substrates. The display panel was placed via a light-transmitting spacer having a vacuum suction hole formed thereon and a surface having a light reflecting surface on which a through hole communicating with the vacuum suction hole was formed. The display panel bonding apparatus is characterized by the above.

  According to the first aspect of the present invention, the light-shielding portion is formed on one of the two light transmissive substrates, and the ultraviolet curable sealant and the liquid crystal are sandwiched between the two light transmissive substrates. Bonding of the display panel to which the two light-transmitting substrates are bonded by irradiating ultraviolet light from the side where the light-shielding part is formed to the integrated display panel, curing the ultraviolet curable sealant In the apparatus, the surface is provided with a stage having a light reflecting surface, and the display panel is placed on the stage via a light-transmitting spacer. Therefore, the spacer itself does not make a shadow. Even if the position of the ultraviolet curable sealant changes, the light incident on the ultraviolet curable sealant is not hindered. In addition, since the spacer itself does not make a shadow, the size of the spacer provided on the surface of the stage is not limited, and the spacer can be freely arranged in a region where an outline is formed so as not to bend the display panel.

  According to the second aspect of the present invention, the light shielding portion is formed on one of the two light transmissive substrates, and the ultraviolet curable sealant and the liquid crystal are sandwiched between the two light transmissive substrates. Bonding of the display panel to which the two light-transmitting substrates are bonded by irradiating ultraviolet light from the side where the light-shielding part is formed to the integrated display panel, curing the ultraviolet curable sealant In the apparatus, the display includes a stage having a plurality of vacuum suction holes formed, a surface having a light reflecting surface, and a through hole communicating with the vacuum suction holes on the stage. Since the panel is placed, in addition to the effect of the invention described in claim 1, the position of the through hole provided in the spacer and the position of the vacuum suction hole provided in the stage surface is adjusted. It is possible to display panel adsorbed immobilized on support, while ultraviolet irradiation, it is possible to avoid that the display panel deviates from the irradiation area of the ultraviolet by the vibration.

An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view showing a configuration of a display panel bonding apparatus according to the invention of this embodiment.
In the figure, 1 is a stage, 11 is a base constituting the stage 1, and 12 is a plurality of vacuum suctions connected to a vacuum line 7 for sucking and holding the liquid crystal panel 3 during light irradiation and supplied with vacuum. A hole 13 is a light reflecting surface that reflects light formed on the base 11, and 2 is a plurality of synthetic quartz glass that is bonded to the light reflecting surface 13 and has a predetermined height from the light reflecting surface 13. The light transmissive spacer 21, which communicates with the vacuum suction hole 12 of the stage 1, has a through hole for vacuum suction of the liquid crystal panel 3 placed on the upper part, 3 indicates a liquid crystal panel, and 31 indicates the liquid crystal panel 3. A color filter substrate 32, a TFT substrate 32 constituting the liquid crystal panel 3, a liquid crystal 33 filled between the substrates 31, 32, and an ultraviolet curable seal 34 for sealing the liquid crystal 33 and bonding the substrates 31, 32 together Agent, 35 is empty The black matrix 4 formed over the boundary region between the liquid crystal 33 and the ultraviolet curable sealant 34 on the lower surface of the filter substrate 31 is an ultraviolet ray on an undesired portion of the liquid crystal panel 3, for example, the liquid crystal 33 or the TFT substrate circuit element in the outline. 5 is an ultraviolet irradiation unit, 51 is a lamp that emits ultraviolet rays shown in a cross-sectional view perpendicular to the longitudinal direction, and 52 is a stage 1 that emits light from the lamp 51. A mirror 6 that reflects to the side, an electromagnetic valve 6 that switches the supply of vacuum to a desired vacuum suction hole 12 of the stage 1 according to the size and shape of the liquid crystal panel 3, and 7 is a vacuum line.

The light reflecting surface 13 of the stage 1 may be one in which the base 11 is made of a metal such as aluminum and the surface thereof is polished. Further, a metal plate or the like that reflects light may be placed on the base 11.
Further, the vacuum suction holes 12 provided in the stage 1 are limited to the minimum size and number in order to minimize the influence on the reflected light.
The spacers 2 provided on the stage 1 are attached by a light-transmitting adhesive (for example, silicon adhesive), and the number and interval of the spacers 2 to be attached depend on the size and weight of the liquid crystal panel to be processed. Is set.
The lamp 51 uses a rod-shaped high-pressure mercury lamp or metal halide lamp. The rod-shaped lamps are arranged in a number corresponding to the width of the workpieces so as to irradiate the entire surface of the liquid crystal panel 3 in a lump.
In the above description, the case where the light shielding mask 4 is used has been described. However, there is a case where light is irradiated without using the light shielding mask. In that case, the color filter formed on the color filter substrate 31 serves as a shading mask.

FIG. 2 is a diagram showing a detailed configuration of the stage 1 and the spacer 2 shown in FIG.
As shown in the figure, these are a stage 1 having a light reflecting surface 13 and a plurality of vacuum suction holes 12 formed on a base 11, and are attached to the light reflecting surface 13 and communicate with the vacuum suction holes 12. And a spacer 2 having a through hole 21.

A plurality of spacers 2 are prepared and attached to the surface of the stage 1 with the positions of the vacuum suction holes 12 of the stage 1 and the through holes 21 of the spacer being aligned. A UV permeable adhesive is used for attachment. The number and interval of the spacers 2 to be attached are set so as not to bend according to the size and weight of the liquid crystal panel 3.
In addition, the height of the spacer 2, that is, the distance from the lower surface of the liquid crystal panel 3 to the light reflecting surface 13 of the stage 1 is obtained in advance by experiments with suitable dimensions. That is, the curing experiment of the sealing agent 34 is performed by changing the distance between the liquid crystal panel 3 and the light reflecting surface 13 so that the sealing agent 34 applied to the shadow of the black matrix 35 has the highest curing height. As a result of experiments with several outline patterns, it was found that the distance between the lower surface of the liquid crystal panel 3 and the light reflecting surface 13 is suitably in the range of 2 mm to 8 mm (preferably about 4 mm).
The light reflecting surface 13 of the stage 1 is a portion that does not reflect light because the light reflected by the light reflecting surface 13 is applied to the ultraviolet curable sealing agent 34 under the black matrix 35 to cure the sealing agent 34. It is desirable that there is no portion that affects the amount of reflected light or the optical path, such as a step or a step. Therefore, it is necessary to keep the vacuum suction holes 12 provided on the surface of the stage 1 to the minimum necessary.
In addition, the spacer 2 is fixed to the surface of the stage 1 by using an adhesive having ultraviolet transmissivity, not fitting into a step or vacuum suction for the above-described reason.
In addition, as an adhesive agent to be used, for example, Hard Rock OP / UV manufactured by Denki Kagaku Kogyo Co., Ltd. is known and commercially available. Such an adhesive is used, for example, for bonding an optical lens such as a camera or binoculars, or a glass display stand.

  The vacuum suction holes 12 are divided into a plurality of groups according to the size of the liquid crystal panel 3 to be sucked, and a vacuum is supplied from a vacuum line 7 branched into each group. 2, in the case of a small liquid crystal panel 3 as shown by a one-dot chain line, as shown in FIG. 1, the electromagnetic valve A is turned on, and a vacuum is supplied only to the vacuum suction hole 12 near the center of the stage 1. As shown by the dotted line, if the liquid crystal panel 3 is large, both the electromagnetic valve A and the electromagnetic valve B are turned on and a vacuum is supplied to the entire vacuum suction hole 12 as shown in FIG.

Next, the operation of the display panel bonding apparatus according to the present invention will be described.
As shown in FIG. 1, the liquid crystal panel 3 to be bonded is placed on the stage 1 with the color filter substrate 31 on which the black matrix 35 is formed facing the ultraviolet irradiation unit 5 and the TFT substrate 32 facing the stage 1 side. Place. The liquid crystal panel 3 placed on the stage 1 is placed on a plurality of light transmissive spacers 2 mounted on the light reflecting surface 13. The plurality of spacers 2 keep the liquid crystal panel 3 at a constant distance from the lower surface of the liquid crystal panel 3 to the light reflecting surface 13 without bending.
When a vacuum is supplied from the vacuum line 7 to the stage 1, the vacuum is supplied to the through hole 21 of the spacer 2 through the vacuum suction hole 12 of the stage 1.
The liquid crystal panel 3 is held and fixed on the spacer 2 by the vacuum supplied to the through hole 21 of the spacer 2. Since the spacer 2 is fixed to the stage 1 with an adhesive, the liquid crystal panel 3 is fixed to the stage 1 via the spacer 2.
Ultraviolet light that cures the sealing agent 34 is irradiated from the ultraviolet irradiation unit 5 toward the liquid crystal panel 3. The light emitted from the ultraviolet irradiation unit 5 is diffused light, and the irradiated light includes many components that are obliquely incident on the liquid crystal panel 3 to be bonded, that is, the light reflecting surface 13 of the stage 1. It is.
As described above, the light shielding mask 4 may not be used.

A part of the ultraviolet rays obliquely incident on the liquid crystal panel 3 from the ultraviolet irradiation unit 5 is irradiated to the ultraviolet curable sealing agent 34 protruding from the black matrix 35, and this is cured. The black matrix 35 passes between the contours formed on the liquid crystal panel 3 and enters the light reflecting plate 13 with or without the light-transmitting spacer 2 and is reflected according to the incident angle. The ultraviolet curable sealant 34 applied under the film is irradiated to cure the ultraviolet curable sealant 34.
As described above, since the spacer 2 is light transmissive, the light reflected by the light reflecting surface 13 of the stage 1 does not become a shadow even if the spacer 2 overlaps the position of the ultraviolet curable sealant 34. The ultraviolet curable sealant 34 is irradiated.

It is sectional drawing which shows the structure of the bonding apparatus of the display panel which concerns on this invention. It is a figure which shows the detailed structure of the stage 1 and the spacer 2 which were shown in FIG. It is sectional drawing which shows an example of a liquid crystal panel (color liquid crystal panel). It is a figure which shows the liquid crystal panel in which the two glass substrates 101 and 102 were bonded together. It is sectional drawing which expanded and showed the structure of the sealing agent 109 vicinity of the liquid crystal panel shown in FIG. It is a figure for demonstrating the problem of the hardening method of the sealing agent described in the gazette.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stage 11 Base 12 Vacuum suction hole 13 Light reflection surface 2 Spacer 21 Through-hole 3 Liquid crystal panel 31 Color filter substrate 32 TFT substrate 33 Liquid crystal 34 UV curable sealant 35 Black matrix 4 Light shielding mask 5 Ultraviolet irradiation part 51 Lamp 52 Mirror 6 Solenoid valve 7 Vacuum line

Claims (2)

A light-shielding portion is formed on one of the two light-transmitting substrates, and the light-shielding portion is formed on the integrated display panel by sandwiching an ultraviolet curable sealant and a liquid crystal between the two light-transmitting substrates. In a bonding apparatus for a display panel that irradiates ultraviolet rays from the side on which the part is formed, cures the ultraviolet curable sealant, and bonds the two light transmissive substrates.
A display panel bonding apparatus comprising a stage having a light reflecting surface on the surface, and the display panel mounted on the stage via a light-transmitting spacer. A light-shielding portion is formed on one of the two light-transmitting substrates, and the light-shielding portion is formed on the integrated display panel by sandwiching an ultraviolet curable sealant and a liquid crystal between the two light-transmitting substrates. In a bonding apparatus for a display panel that irradiates ultraviolet rays from the side on which the part is formed, cures the ultraviolet curable sealant, and bonds the two light transmissive substrates.
The display panel is mounted via a light transmissive spacer having a stage having a plurality of vacuum suction holes and a surface having a light reflecting surface, and a through hole communicating with the vacuum suction hole is formed on the stage. A display panel laminating device characterized by being placed.

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