JP2007256770A - Liquid crystal panel and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal panel which is superior in moisture proofness by preventing water from infil;trating into a connection part between a leading electrode and a flexible printed circuit (FPC). <P>SOLUTION: In the liquid crystal panel including a liquid crystal cell having a liquid crystal interposed between a pair of substrates (1 and 15) and a FPC 5 connected to an end part of at least one of the pair of substrates, a laminate film 10 is disposed so as to cover the liquid crystal cell and the FPC 5 throughout, and the laminate film 10 has an opening 16, and an end part of the FPC 5 is led out of the laminate film 10 through the opening 16. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal panel that can be used as a display element or a light modulation element, and a method for manufacturing the same.

  In general, in a liquid crystal panel, a liquid crystal layer is sealed between a pair of substrates, pixels are formed by electrodes provided on the respective substrates so as to face each other through the liquid crystal layer, and an electric signal is applied to the pixels to By controlling the optical behavior, the amount of transmitted light is controlled and displayed. In order to apply an electrical signal to the electrodes forming this pixel, usually, a lead electrode for inputting / outputting electrical signals is provided at the non-display portion of at least one of the pair of substrates and at the end of the substrate. It has been. A flexible printed circuit board (FPC) for connecting to an external circuit is electrically connected to the lead electrode by a conductive adhesive. As the conductive adhesive, an anisotropic conductive film (ACF) having adhesiveness is used.

  However, if dirt adheres to the connection between the extraction electrode and the FPC, or if there is a gap at the connection interface between the extraction electrode and the FPC, when the liquid crystal panel is driven for a long time or in a high temperature and high humidity atmosphere. However, the electrode material is corroded in a part of the extraction electrode, causing a disconnection, and moisture enters the liquid crystal layer in the liquid crystal cell, resulting in unstable driving voltage.

  Therefore, in order to prevent moisture from entering the connecting portion between the extraction electrode and the FPC, an insulating resin is molded on the connecting portion, or the entire liquid crystal panel and a part of the FPC are covered by sputtering or CVD. For example, a thin insulating film is formed (see, for example, Patent Document 1).

International Publication No. WO03 / 003108 Pamphlet (pages 22-24, Fig. 6)

  However, just by molding an insulating resin at the connection portion between the extraction electrode and the FPC as in the prior art, there is a possibility that moisture may enter the adhesive interface with the insulating resin. In the method of forming a thin insulating film by the above method, there is a problem that the apparatus becomes large and the manufacturing method becomes complicated and troublesome.

  The present invention has been made in view of such a problem, and prevents moisture from entering the connection portion between the extraction electrode and the FPC, and further, moisture is introduced into the liquid crystal layer in the liquid crystal cell via a sealing material. An object of the present invention is to provide a liquid crystal panel that is prevented from entering and has excellent moisture resistance.

  A liquid crystal panel of the present invention includes a liquid crystal cell having a liquid crystal sandwiched between a pair of substrates, and a flexible printed circuit board connected to an end of at least one of the pair of substrates, the liquid crystal cell and the flexible substrate, The laminate film is disposed so as to cover the entire structure, and the laminate film has an opening, and the end of the flexible printed circuit board is led out of the laminate film from the opening. Preferably, at least one of the pair of substrates is a resin substrate.

  A method of manufacturing a liquid crystal panel according to the present invention includes a liquid crystal panel including a liquid crystal cell having a liquid crystal sandwiched between a pair of substrates, and a flexible printed circuit connected to an end of at least one of the pair of substrates. Prepared, a laminating step for sealing the liquid crystal cell and the flexible printed circuit board together with a laminate film, an opening forming step for forming an opening by providing a cut in a part of the laminate film, A deriving step of deriving an end portion of the flexible printed board opposite to an end portion connected to the substrate to the outside of the laminate film.

  In the laminating step, a release material is disposed at an end portion of the flexible substrate led out to the outside of the laminate film. Moreover, the derivation | leading-out process has the process of removing the mold release material and the laminate film on a mold release material, It is characterized by the above-mentioned.

  Alternatively, in the laminating process, the end of the flexible printed circuit board is folded to the liquid crystal cell side and sealed with the laminate film, and in the derivation process, the end of the flexible printed circuit board is pulled out to the outside of the laminated film. It is derived.

  Preferably, at least one of the pair of substrates is a resin substrate.

  As described above, according to the present invention, a simple type laminating film packing apparatus is used, which includes a liquid crystal cell and a part of an FPC connected to the liquid crystal cell, and can be wrapped while being sealed with a laminating film. Do not need. Furthermore, since the entire liquid crystal panel is covered with the laminate film, it is possible to prevent moisture from entering the liquid crystal cell. In addition, since the connection part between the lead electrode of the liquid crystal cell and the FPC can be completely covered with the laminate film, it is possible to prevent moisture from entering the interface of the connection part and produce a liquid crystal panel with excellent moisture resistance. can do. Therefore, even when the liquid crystal panel is operated for a long time in a high temperature and high humidity state, it is possible to prevent galvanic corrosion of the extraction electrode portion and perform stable display.

  In addition, since the end portion of the FPC that is not connected to the liquid crystal cell is not covered with the laminate film, the FPC and the external circuit can be easily connected. Furthermore, a liquid crystal panel using a flexible resin substrate has the advantage that the liquid crystal panel itself has flexibility. However, since the whole is covered with a laminate film, moisture resistance is maintained without losing flexibility, which is also a characteristic of the liquid crystal panel. Can increase the sex.

  In order to describe the present invention in more detail, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a plan view of a film liquid crystal display panel according to the present invention, and FIGS. 2 to 7 are cross-sectional views taken along line A-A 'shown in FIG.

[Example 1: FIGS. 1 to 4]
Example 1 of the present invention will be described. A liquid crystal panel according to an embodiment of the present invention is a reflective or transmissive liquid crystal panel used for a mobile phone, a small information device, a watch, or the like. The substrate used is a resin substrate and has flexibility. In this embodiment, the resin substrate is used for both of the pair of substrates. However, as a matter of course, a glass substrate may be used, or a resin substrate may be used for only one of the pair of substrates.

  First, a liquid crystal panel is prepared in which a flexible printed circuit board (FPC) on which a driving integrated circuit (IC) is mounted is connected to the end of a liquid crystal cell substrate by thermocompression bonding through an anisotropic conductive film. Next, a laminating process is performed in which the entire liquid crystal panel is covered with a laminating film that is a thermal adhesive film on which a gas barrier layer such as SiOx that is an insulating coating material is formed. At this time, not only the liquid crystal cell but also the end portion of the FPC not connected to the liquid crystal cell is sealed with a laminate film.

  As a device used for such a laminating process, a simple laminate packing device such as a commercially available one can be used. In addition, any apparatus can be used as long as it can cut a laminate film and thermocompress the periphery in accordance with the size of the liquid crystal panel.

  FIG. 1 shows a plan view of a liquid crystal panel laminated by a laminating process. Hereinafter, the configuration of a liquid crystal panel including a film liquid crystal cell and an FPC connected to each substrate of the film liquid crystal cell will be described with reference to FIG. The film liquid crystal cell has a first substrate 1 which is a resin substrate having a thickness of 0.1 to 0.12 mm having a large number of striped transparent electrodes 2 and a thickness 0 having a large number of striped transparent electrodes 2. A liquid crystal 9 is sealed by superimposing a second substrate 15, which is a resin substrate of 1 to 0.12 mm, through a sealing material 4. And it has the display area which consists of a pixel part which is the intersection of the transparent electrode 2 of the 1st board | substrate 1 and the transparent electrode 2 of the 2nd board | substrate 15. FIG.

  The end of the substrate where the first substrate 1 and the second substrate 15 of the film liquid crystal cell do not overlap is an area connected to the electrode wiring 6 of the FPC 5 and extends from the other substrate with a width of 1 to 3 mm. Yes. An extraction electrode from which the transparent electrode 2 is extracted as it is is formed at the end of the substrate. An anisotropic conductive film (ACF) 7 in which conductive particles are contained in an acrylic resin or an epoxy resin is disposed on the lead electrode at the end of the substrate, and the electrode wiring 6 of the FPC 5 is further disposed thereon. These are thermocompression-bonded, and the transparent electrode 2 of the film substrate and the electrode wiring 6 of the FPC are electrically connected via the conductive particles of the ACF 7.

  The FPC 5 is mounted with a driving integrated circuit (IC) 8 for sending an electric signal to the transparent electrode 2. Similar to the connection between the lead electrode and the electrode wiring 6 of the FPC 5, the IC 8 and the electrode wiring 6 of the FPC 5 are thermocompression bonded via the ACF 7 and are electrically connected by conductive particles.

  The entire liquid crystal panel including the film liquid crystal cell, the FPC 5 connected to the end of the substrate of the film liquid crystal cell, and the IC 8 mounted on the FPC 5 is covered and covered with the laminate film 10. As a method of covering the entire liquid crystal panel with the laminate film 10, a general laminate film packing apparatus or the like is used. For example, the entire liquid crystal panel is covered with the laminate film 10 from both sides, the periphery is thermocompression bonded, the laminate film 10 is adhered and sealed, and the periphery of the laminate film 10 is cut off according to the outer shape of the liquid crystal panel. Can do.

  FIG. 2 is a cross-sectional view taken along the line A-A ′ of FIG. As shown in FIG. 2, the first substrate 1 and the second substrate 15 are opposed to each other with a predetermined gap provided by a spacer 3, adhered by a sealant 4, and a liquid crystal layer 9 is sealed in the gap. The sealing part 12 is sealed with a sealing agent to ensure airtightness. As shown in FIG. 2, the laminated film 10 has a vapor-deposited film 13 such as SiOx, which is a gas barrier layer, formed on the surface thereof in order to improve moisture resistance.

In FIG. 2, since the electrode wiring 6 of the FPC 5 is completely covered with the laminate film 10, the electrode wiring 6 of the FPC 5 cannot be connected to another external circuit. Then, the derivation | leading-out process which derives | leads out the other edge part of FPC which is not connected with a film liquid crystal cell to the outer side of a laminate film next is performed.

  FIG. 3 is a cross-sectional view illustrating the derivation process. As shown in FIG. 3, a tape-shaped release material 14 is disposed at an end portion not connected to the liquid crystal cell of the FPC 5. The release material 14 is arranged on the electrode wiring 6 of the FPC 5 to be led out. Then, at the boundary position where the release material 14 is arranged, at the position 11 in FIG. 1, the laminate film is partially cut with a laser or a cutter to the depth of the upper part of the release material as shown in FIG. Part 16 is formed. This process is referred to as an opening forming process.

  Next, the release material 14 and the laminated film 10 thereon are removed. Since the opening 16 is formed, a part of the laminate film is separated, and the release material 14 is arranged on the end portion of the electrode wiring 6 of the FPC 5, so that the release material 14 and the laminate film 10 thereon can be easily attached. Can be removed. As shown in FIG. 4, the electrode wiring 6 of the FPC 5 is exposed and the end of the FPC 5 is led out to the outside of the laminate film 10. This process is referred to as a derivation process. Thus, since the end portion of the electrode wiring 6 of the FPC 5 is led out to the outside, it becomes easy to connect the electrode wiring 6 to an external circuit or the like.

  As shown in FIG. 4, the liquid crystal panel manufactured according to this example can prevent moisture from entering the liquid crystal cell because the entire liquid crystal panel is covered with the laminate film. Further, since the connection portion between the liquid crystal cell and the electrode wiring 6 of the FPC 5 and the connection portion between the electrode wiring 6 of the FPC 5 and the IC 8 are all covered with the laminate film, moisture can penetrate into the interface of these connection portions. Therefore, a liquid crystal panel excellent in moisture resistance can be manufactured.

[Example 2: FIGS. 5 to 7]
Next, another embodiment will be described with reference to FIGS. As shown in FIG. 5, the entire liquid crystal panel is covered with a laminate film 10 in a state where the electrode wiring 6 portion of the FPC 5 to be connected to an external circuit is folded to the liquid crystal cell side. The same process as in Example 1 can be used for the laminating process for covering with the laminating film 10. Note that a release material 14 is disposed on the electrode wiring 6 of the folded FPC 5.

  Next, a derivation step is performed for deriving the other end of the FPC 5 not connected to the film liquid crystal cell to the outside of the laminate film. FIG. 6 is a cross-sectional view illustrating the derivation process. As shown in FIG. 6, a part of the laminate film 10 is cut with a laser, a cutter, or the like to such a depth that the electrode wiring 6 of the FPC 5 is not broken, and the opening 16 is formed. This process is referred to as an opening forming process.

  Next, the end of the FPC 5 is pulled out from the opening 16, the release material 14 is removed, and the electrode wiring 6 of the FPC 5 is led out as shown in FIG. This process is referred to as a derivation process. Thus, since the electrode wiring 6 of the FPC 5 is led out, it becomes easy to connect the electrode wiring 6 to an external circuit or the like.

  As shown in FIG. 7, the liquid crystal panel manufactured according to the present embodiment has the entire liquid crystal cell covered with a laminate film, so that moisture can be prevented from entering the liquid crystal cell. Since the connection part between the electrode wiring 6 and the connection part between the electrode wiring 6 of the FPC 5 and the IC 8 are all covered with the laminate film, it is possible to prevent moisture from entering the interface of these connection parts and to prevent moisture. A liquid crystal panel with excellent properties could be manufactured.

  The FPC 5 and the IC 8 shown in FIG. 1 are connected and arranged separately on the two sides of the liquid crystal cell. However, the FPC 5 and the IC 8 may be mounted on the one side by drawing a transparent electrode. .

It is the figure which showed the top view of the liquid crystal panel of this invention. It is sectional drawing which showed the manufacturing process of the liquid crystal panel of this invention. It is sectional drawing which showed the manufacturing process of the liquid crystal panel of this invention. It is sectional drawing which showed the manufacturing process of the liquid crystal panel of this invention. It is sectional drawing which showed the manufacturing process of the liquid crystal panel of this invention. It is sectional drawing which showed the manufacturing process of the liquid crystal panel of this invention. It is sectional drawing which showed the manufacturing process of the liquid crystal panel of this invention.

Explanation of symbols

1 First substrate 2 Transparent electrode 3 Spacer 4 Sealing material 5 FPC
6 Electrode wiring 7 Anisotropic conductive film 8 IC
9 Liquid crystal 10 Laminate film 11 Cut part 12 Sealing part 13 Gas barrier layer 14 Release material (tape)
15 Second substrate 16 Opening

Claims (7)

In a liquid crystal panel comprising a liquid crystal cell sandwiching liquid crystal between a pair of substrates and a flexible printed circuit board connected to an end of at least one of the pair of substrates,
A laminate film is disposed so as to cover the entire liquid crystal cell and the flexible substrate. The laminate film has an opening, and an end of the flexible printed circuit board is led out of the laminate film from the opening. A liquid crystal panel characterized by that.   The liquid crystal panel according to claim 1, wherein at least one of the pair of substrates is a resin substrate. A liquid crystal panel comprising a liquid crystal cell having a liquid crystal sandwiched between a pair of substrates and a flexible printed circuit connected to an end of at least one of the pair of substrates is prepared. A laminating process for sealing while adhering with a laminating film;
An opening forming step of forming an opening by providing a cut in a part of the laminate film, and an end of the flexible printed board opposite to the end connected to the substrate from the opening. A method for producing a liquid crystal panel, comprising: a deriving step for deriving the laminate film to the outside.   4. The method for manufacturing a liquid crystal panel according to claim 3, wherein in the laminating step, a release material is disposed at an end portion of the flexible substrate led out to the outside of the laminate film.   The liquid crystal panel manufacturing method according to claim 4, wherein the deriving step includes a step of removing the release material and the laminate film on the release material. In the laminating step, the entire liquid crystal panel in a state where the end of the flexible printed circuit board is folded to the liquid crystal cell side is sealed while being closely adhered to the laminating film,
5. The method of manufacturing a liquid crystal panel according to claim 3, wherein, in the derivation step, an end portion of the flexible printed circuit board is pulled out and led out to the outside of the laminate film.   The method for manufacturing a liquid crystal panel according to claim 3, wherein at least one of the pair of substrates is a resin substrate.

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