JP5975869B2 - Manufacturing method of liquid crystal display device - Google Patents

Description

  The present invention relates to a liquid crystal display device and a method for manufacturing the same.

  For example, a liquid crystal display device is formed by bonding a silicon substrate having a pixel electrode formed on the surface thereof and a glass substrate having a counter electrode formed on the surface opposite thereto with a peripheral adhesive at predetermined positions and intervals. A liquid crystal display panel called LCOS (Liquid Crystal On Silicon) in which liquid crystal is sealed in the gap is mounted on a circuit board, and a potential difference is applied between the pixel electrode and the counter electrode through the circuit board to thereby align the liquid crystal. Various displays are obtained by controlling.

  FIG. 5 is a cross-sectional view showing a conventional liquid crystal display device. The first substrate 2 is, for example, a silicon substrate, and a plurality of pixel electrodes 5 are formed on one surface, and an alignment film 8 is formed thereon. The second substrate 3 is, for example, a glass substrate. A counter electrode (transparent electrode) 7 is formed on one surface, and an alignment film 8 is formed thereon. The first substrate 2 and the second substrate 3 are bonded to each other at a predetermined interval and in a positional relationship shifted in the horizontal direction via a sealing material 4 including a spacer (not shown) having a predetermined size. A liquid crystal display panel 1 is configured by enclosing the liquid crystal 10.

  The liquid crystal display panel 1 is mounted on the circuit board 9 with the first substrate 2 facing down, and the pixel electrodes 5 formed on the first substrate 2 are connected to the electrode pads 12 on the circuit board 9 by wires 11. The counter electrode 7 electrically connected and formed on the second substrate 3 is electrically connected with the electrode pad 13 and the conductive resin 14 (for example, silver paste) on the circuit board 9 disposed at a position facing the counter electrode 7. The pixel electrodes 5 and the counter electrode 7 are connected to each other and supplied with different potentials.

  FIG. 6 is a cross-sectional view for explaining a foreign matter removal method in liquid crystal according to the prior art, showing (A) a state before removal of foreign matter and (B) a state after removal of foreign matter. In the liquid crystal display device according to the prior art, if there is a foreign substance 15 in the liquid crystal 10, the liquid crystal 10 does not partially exist due to the foreign substance 15, and light modulation cannot be performed in that part, and display defects may occur. is there. In this case, for example, the display function can be recovered by irradiating the foreign material 15 with the laser 16 through the second substrate 3 and removing (vaporizing) the foreign material 15. (For example, see Patent Document 1)

JP-A-8-304802

  In the prior art, foreign matter can be removed by irradiating the foreign matter with a laser, but at the same time, the pixel electrode around the foreign matter may be damaged by the laser. In this case, voltage can be applied to the liquid crystal even if the foreign matter is removed. As a result, there is a problem that display defects cannot be eliminated.

  The present invention has been made in view of the above problems, and provides a liquid crystal display device that can remove a foreign substance in liquid crystal that causes a display defect and can reliably restore the display function, and a method for manufacturing the same. The purpose is to provide.

A first substrate having a pixel electrode; and a second substrate having a counter electrode opposite to the pixel electrode, wherein the first substrate and the second substrate are bonded together with a sealing material at a predetermined position and interval. A method of manufacturing a liquid crystal display device in which a liquid crystal is sealed in a space formed by forming the pixel electrode by laminating a plurality of electrode films, and an electrode located in a lower layer of the plurality of electrode films simultaneously melting point of the membrane and the step of configuring to be higher than the melting point of the electrode film positioned in the upper layer, by irradiating a laser foreign matter that exists around the upper surface of the pixel electrode to remove the foreign matter, the pixel a method of manufacturing a liquid crystal display device having a step you remove the electrode film positioned on the upper layer of the plurality of electrode films constituting the electrode.

  It can be set as the manufacturing method of the liquid crystal display device which has the process of fluidizing and filling the said liquid crystal in the space formed by removing the said electrode film located in an upper layer with the said laser.

  According to the present invention, since the pixel electrode has a multilayer structure, even if the upper pixel electrode is damaged by a laser when removing foreign matter, a voltage can be applied to the liquid crystal by the lower pixel electrode. Can be reliably recovered.

Sectional drawing which shows the liquid crystal display device by Example 1 of this invention It is sectional drawing for demonstrating the manufacturing method of the liquid crystal display device by Example 1 of this invention, (A) The state before foreign material removal, (B) The state after foreign material removal Sectional drawing which shows the liquid crystal display device by Example 2 of this invention It is sectional drawing for demonstrating the manufacturing method of the liquid crystal display device by Example 2 of this invention, (A) The state before foreign material removal, (B) The state after foreign material removal Sectional drawing which shows the liquid crystal display device by a prior art It is sectional drawing for demonstrating the manufacturing method of the liquid crystal display device by a prior art, (A) The state before foreign material removal, (B) The state after foreign material removal

  FIG. 1 is a sectional view showing a liquid crystal display device according to Embodiment 1 of the present invention. The liquid crystal display device 1 includes a first substrate 2 and a second substrate 3. The first substrate 2 is, for example, a silicon substrate. A pixel electrode (5, 6) having a multilayer structure formed by laminating a plurality of electrode films is formed on one surface, and the liquid crystal 10 is aligned thereon. An alignment film 8 is formed for this purpose. The second substrate 3 is, for example, a glass substrate. A counter electrode (transparent electrode) 7 is formed on one surface, and an alignment film 8 for aligning the liquid crystal 10 is further formed thereon. The first substrate 2 and the second substrate 3 are bonded to each other by a sealing material 4, and the liquid crystal 10 is sealed in the gap between the two substrates formed thereby. The back surface of the first substrate 2 and the top surface of the circuit substrate 9 are bonded to each other with a double-sided tape (not shown). In this state, the electrode pads 12 on the circuit substrate 9 and the pixel electrodes (5, 6) on the first substrate 2 Are electrically connected by the wire 11, and the counter electrode 7 on the second substrate 3 and the electrode pad 13 on the circuit substrate 9 are electrically connected by the conductive resin 14, whereby the liquid crystal display device 1 is configured. Yes.

  Here, the present embodiment is different from the prior art in that the pixel electrode on the first substrate 2 is configured by laminating a plurality of electrode films. In this embodiment, the pixel electrode is the first pixel electrode. 5 and the second pixel electrode 6. Of the stacked electrode films, the second pixel electrode 6 located in the lower layer has the same width and thickness as the first pixel electrode 5 located in the upper layer, and is made of a material having a higher melting point than the first pixel electrode 5. As the combination thereof, for example, Al is used as the first pixel electrode 5, and any one of W, Ti, and Mo is used as the second pixel electrode 6. Although the pixel electrode has a two-layer structure here, it can also have a structure of three or more layers. Even in this case, the relationship between the melting points of each pixel does not change, and the material having a higher melting point as the lower electrode film is formed. Consists of. Further, the width, thickness, material, and the like of the first pixel electrode 5 and the second pixel electrode 6 are not limited to the above configuration, and other configurations can be appropriately selected.

  2A and 2B are cross-sectional views for explaining a method of manufacturing the liquid crystal display device according to the first embodiment of the present invention, showing (A) a state before removing foreign matter and (B) a state after removing foreign matter. As shown in FIG. 2A, when there is a foreign substance 15 in the liquid crystal 10, the liquid crystal 10 does not exist partially due to the foreign substance 15, and light modulation cannot be performed in that part, resulting in a display defect. There is. In this case, for example, as shown in FIG. 2B, the foreign material 15 is irradiated with the laser 16 through the second substrate 3, and the foreign material 15 is removed (vaporized). At this time, even if the upper-layer first pixel electrode 5 (and the alignment film 8 thereon) is removed by the laser when the foreign matter 15 is removed, the second pixel electrode 6 exists in the lower layer, so that at least the second pixel A voltage can be applied to the liquid crystal 10 between the electrode 6 and the counter electrode 7. Note that the liquid crystal display device 1 is a reflective liquid crystal display device, and the illumination light is incident from the second substrate 3 side. Therefore, even if the second pixel electrode 6 exists below the first pixel electrode 5, the first pixel The reflection of light by the electrode 5 is not hindered.

  In addition, after the irradiation of the laser 16, the liquid crystal 10 is heated to an isotropic phase transition temperature or more to reduce the viscosity of the liquid crystal 10 to be fluidized, and the laser irradiation portion (the space after removing the foreign matter) is filled with the liquid crystal 10. By doing so, the display function can be recovered more effectively.

  FIG. 3 is a sectional view showing a liquid crystal display device according to Embodiment 2 of the present invention. The difference from the liquid crystal display device in Example 1 is that an insulating film 17 is formed between the first pixel electrode 5 and the second pixel electrode 6. The insulating film 17 is made of, for example, transparent silicon oxide or silicon nitride. The first pixel electrode 5 and the second pixel electrode 6 penetrate a part of the insulating film 17 and are electrically connected to each other.

  4A and 4B are cross-sectional views for explaining a method of manufacturing a liquid crystal display device according to Embodiment 2 of the present invention, showing (A) a state before removing foreign matter and (B) a state after removing foreign matter. In the second embodiment, similarly to the first embodiment, the foreign matter 15 in the liquid crystal 10 is irradiated with the laser 16 through the second substrate 3 to remove (vaporize) the foreign matter 15. At this time, when the uppermost alignment film 8 and the lower first pixel electrode 5 disappear together with the foreign matter 15, the uppermost layer becomes the insulating film 17, but the second pixel electrode 6 and the counter electrode 7 are interposed via the insulating film 17. A voltage can be applied to the liquid crystal 10. Note that the liquid crystal display device 1 is a reflective liquid crystal display device, and the illumination light is incident from the second substrate 3 side. Therefore, even if the insulating film 17 and the second pixel electrode 6 exist below the first pixel electrode 5. The reflection of light by the first pixel electrode 5 is not hindered.

  In addition, after the irradiation of the laser 16, the liquid crystal 10 is heated to an isotropic phase transition temperature or more to reduce the viscosity of the liquid crystal 10 to be fluidized, and the laser irradiation portion (the space after removing the foreign matter) is filled with the liquid crystal 10. By doing so, the display function can be recovered more effectively.

  In the configuration of this embodiment, since the insulating film 17 is interposed between the first pixel electrode 5 and the second pixel electrode 6, when the first pixel electrode 5 disappears by the laser 16, the second pixel electrode 6. Can take less damage. That is, the reflectance of the pixel electrode (second pixel electrode 6) that is important in the reflective liquid crystal display device is not impaired.

DESCRIPTION OF SYMBOLS 1 Liquid crystal display device 2 1st board | substrate 3 2nd board | substrate 4 Seal material 5 1st pixel electrode 6 2nd pixel electrode 7 Counter electrode (transparent electrode)
8 Alignment film 9 Circuit board 10 Liquid crystal 11 Wire 12 Electrode pad 13 Electrode pad 14 Conductive resin 15 Foreign material 16 Laser 17 Insulating film

Claims (2)

A first substrate having a pixel electrode; and a second substrate having a counter electrode opposite to the pixel electrode, wherein the first substrate and the second substrate are bonded together with a sealing material at a predetermined position and interval. A method for manufacturing a liquid crystal display device in which liquid crystal is sealed in a space formed by:
The pixel electrode is configured by stacking a plurality of electrode films, and the melting point of the electrode film located in the lower layer of the plurality of electrode films is configured to be higher than the melting point of the electrode film located in the upper layer. When,
At the same time to remove the foreign matter by irradiating a laser foreign matter exists on the upper surface periphery of the pixel electrode, the step remove the electrode film positioned on the upper layer of the plurality of electrode films constituting the pixel electrode When,
A method for manufacturing a liquid crystal display device, comprising: The electrode film positioned on the upper layer in a space formed by removing by said laser, a method of manufacturing a liquid crystal display device according to claim 1, characterized in that it comprises a step of filling the liquid crystal by fluidizing .

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