JP2007219300A - Display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display apparatus whose manufacturing efficiency is excellent, while a size of the apparatus is reduced. <P>SOLUTION: A liquid crystal display apparatus 10 comprises: a thin film transistor (TFT) substrate 20 including an IC mounting area 30 on which a driver IC 40 for driving display is mounted, and a display area 31 in which a display section is formed; and a flexible printed circuit (FPC) substrate 12 connected to an FPC connection area 32 between the IC mounting area 30 and the display area 31 on the TFT substrate 20. The FPC substrate 12 is provided so that a face of a side connected to the TFT substrate 20 faces the substrate and extends to the display area 31 side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device.

  2. Description of the Related Art Conventionally, COG (Chip on glass) mounting in which a display driving chip component is directly provided on a substrate of a display device such as a liquid crystal display device is known. COG mounting is a technique for mounting a driver semiconductor chip directly on a liquid crystal glass. Here, FIG. 4 shows a plan view of the liquid crystal display device 100 on which general COG mounting is performed.

  The liquid crystal display device 100 includes a liquid crystal display panel 103 composed of a thin film transistor (TFT) substrate 101 and a color filter (CF) substrate 102, a flexible printed circuit board 104 connected to the liquid crystal display panel 103, a backlight (not shown), and the like. It consists of

  The liquid crystal display panel 103 includes, on the TFT substrate 101, in order from the inside to the outside of the substrate, a display region 105 for forming a display portion, an IC mounting region 106 for mounting a display portion driver IC 109, and a surface. An FPC connection area 107 for connecting the flexible printed circuit board 104 provided with each element 110 is formed.

In addition, as a technology related to the COG mounting structure of a display device provided with such a flexible printed circuit board, Patent Document 1 includes a drive IC, an anisotropic conductive film, and a glass substrate. A plurality of function bumps and dummy bumps are provided, the dummy bumps are distributed at the four corners of the driving IC, and the plurality of function conductive pads and dummy conductive pads on the glass substrate have the same positions corresponding to the function bumps and dummy bumps on the driving IC, respectively. COG mounting in which the drive IC function bumps and glass substrate function conductive pads, or the drive IC dummy bumps and glass substrate dummy conductive pads are electrically connected via an anisotropic conductive film. A structure-related invention is disclosed. And according to this, it is described that a COG mounting structure with excellent electrical connection can be provided.
JP 2005-26682 A

  However, in the conventional liquid crystal display device 100 shown in FIG. 4 and the liquid crystal display device shown in Patent Document 1, the flexible printed circuit board 104 is formed so as to be drawn out from the end of the panel, so as shown in FIG. In addition, the flexible printed circuit board 104 must be bent inward in designing a module such as miniaturization of the apparatus. For this reason, it is necessary to consider necessary dimensions for bending, such as a dividing margin and a mounting margin (d shown in FIG. 5), and there is a problem that manufacturing efficiency is deteriorated. Here, the division margin means that it is difficult to divide the substrate substantially in size when dividing the substrate. In this case, the dimensional margin is taken in advance from the end of the substrate to the bending start position of the flexible printed circuit board 104 (horizontal portion). In addition, the mounting margin defines the mounting accuracy with a certain amount of error because it is difficult to substantially center the connection position when crimping to the board. A dimensional margin taken in advance from the end portion of the substrate to the bending start position of the flexible printed circuit board 104 (horizontal portion) assuming a case of deflection.

  Furthermore, when the device is modularized by bending the flexible printed circuit board 104 extending outward, there is a problem that the thickness of the device increases correspondingly, and it is difficult to reduce the size of the display device.

  The present invention has been made in view of such various points, and an object of the present invention is to provide a display device that has good manufacturing efficiency and enables downsizing of the device.

  A display device according to the present invention includes a substrate having an IC mounting region on which a display driver IC is mounted and a display region for forming a display unit, and an FPC connection region between the IC mounting region and the display region on the substrate. A flexible printed circuit board connected to the flexible printed circuit board, wherein the flexible printed circuit board is provided such that a surface connected to the printed circuit board faces the substrate and extends to the display region side. And

  According to such a configuration, the flexible printed circuit board provided on the substrate is electrically connected to the display driver IC on the substrate, and extends from the connection region to the inside of the substrate (display region side). Provided. Therefore, as in the conventional structure shown in FIG. 5 in which the flexible printed board is extended outward, bent from there, and pulled back toward the apparatus, it is not necessary to take a dividing margin and a mounting margin of the flexible printed board with respect to bending. Therefore, manufacturing efficiency is improved. Moreover, since the flexible printed circuit board can be accommodated inside the apparatus without being bent, the thickness of the bent portion of the flexible printed circuit board does not occur. For this reason, the display device can be miniaturized.

  The display device according to the present invention further includes another substrate provided to face the substrate in the display region on the substrate, and the thickness of the other substrate is less than twice that of the flexible printed circuit board. There may be.

  According to such a configuration, in the display device configured with two opposing substrates, the flexible printed circuit board provided on one substrate is not folded on the other board provided in the display region. It is pulled out and rides on the other board. At this time, since the thickness of the other substrate is twice or less than that of the flexible printed circuit board, the level difference generated when the flexible printed circuit board rides on the other circuit board is reduced. Therefore, it is possible to suppress the flexible printed board from being damaged by rubbing with the other board at the step.

  Furthermore, in the display device according to the present invention, the display driving driver IC is provided so as to extend along one side of the substrate, and the flexible printed circuit board is provided with a plurality of elements on at least one surface. The plurality of elements may be provided so as to extend along the display driving driver IC on the flexible printed circuit board.

  According to such a configuration, since the plurality of elements of the flexible printed circuit board are provided so as to extend along the display driving driver IC, the area of the flexible printed circuit board in the direction extending to the display area can be reduced. Can do. Accordingly, a reduction in display area can be suppressed.

  As described above, according to the present invention, it is possible to provide a display device that has good manufacturing efficiency and enables downsizing of the device.

  Hereinafter, a display device according to an embodiment of the present invention will be described in detail with reference to the drawings. Further, a liquid crystal display device will be described as a display device. The present invention is not limited to the following embodiment.

(Embodiment)
(Configuration of the liquid crystal display device 10)
1 and 2 are a cross-sectional view and a plan view of a liquid crystal display device 10 according to an embodiment of the present invention, respectively.

  The liquid crystal display device 10 includes a liquid crystal display panel 11, a flexible printed circuit board 12 connected to the liquid crystal display panel 11, a backlight 13, and the like.

  The liquid crystal display panel 11 includes a TFT substrate 20 and a CF substrate 21 bonded together with a sealing material, and a liquid crystal (not shown) accommodated between both substrates, and includes an IC mounting area 30, a display area 31, and And an FPC connection area 32 between the IC mounting area 30 and the display area 31.

  The TFT substrate 20 is formed of a transparent substrate such as glass or quartz. The TFT substrate 20 has a region (projected region 33) that projects to one side with respect to the CF substrate 21. In the overhang area 33, an IC mounting area 30 and an FPC connection area 32 are provided in this order from the outside to the inside. On the inner side (liquid crystal side) of the TFT substrate 20, a plurality of pixel electrodes arranged in a matrix (not shown) and a plurality of data lines extending to the overhanging region 33 in gap portions between the pixel electrodes are formed. . The pixel electrode is made of a transparent conductive material such as ITO (Indium Tin Oxide).

  In the IC mounting area 30, a display driving driver IC 40 for driving each display element of the display unit is formed. The display driver IC 40 is COG-mounted so as to extend along the side of the TFT substrate 20. The display driver IC 40 supplies a data signal to the data line, and is mounted on the TFT substrate 20 via an anisotropic conductive film in which conductive particles are dispersed in an adhesive. That is, the portion of the data line extending to the protruding region 33 and the display driving driver IC 40 are electrically connected through the conductive particles in the anisotropic conductive film.

  The CF substrate 21 is formed of a transparent substrate such as glass or quartz. The CF substrate 21 has a fine pattern (not shown) formed of three primary colors of red (R), green (G), and blue (B) formed on a transparent substrate. These fine patterns are provided with a black matrix (not shown) as a border for obtaining contrast. In addition to the combination of RGB, complementary colors of cyan, magenta, and yellow may be used as constituents of the fine pattern. The CF substrate 21 is bonded to the TFT substrate 20 with a sealing material, and liquid crystal is provided between the two substrates. The region having the liquid crystal is the display region 31 and constitutes the display portion of the CF substrate 21 and the TFT substrate 20.

  As for the flexible printed circuit board 12, the vicinity of one side edge part is between the IC mounting area 30 and the display area 31 (FPC connection area 32) in the projecting area 33 of the TFT substrate 20 through the anisotropic conductive film. It is connected. As shown in FIG. 3, the flexible printed circuit board 12 is provided so that the surface connected to the FPC connection region 32 faces the TFT substrate 20 and extends toward the display region 31. The flexible printed circuit board 12 is provided with elements 50 such as wiring and electronic components on the surface of a flexible film base formed of polyimide or the like. These elements 50 are provided on the flexible printed circuit board 12 so as to extend along the display driving driver IC 40 in the IC mounting region 30.

  As shown in the plan view (FIG. 1) of the flexible printed circuit board 12 formed in this way, the elements 50 are arranged along one side of the circuit board, and the width direction (direction extending to the display region 31). ) Can be formed short.

  The thickness of the flexible printed circuit board 12 is formed to be less than half of the thickness of the substrate (CF substrate 21) extending from the opposing substrate (TFT substrate 20) to the upper surface. For this reason, the flexible printed circuit board 12 can draw a smooth curve without being bent, and can exceed the stepped portion of the CF substrate 21 existing when climbing on the CF substrate 21. Further, when the flexible printed circuit board 12 is mounted on the TFT substrate 20 at the time of manufacture, interference of the CF substrate 21 is suppressed, and the CF substrate 21 and the display driving driver IC 40 can be easily crimped and fixed.

  The backlight unit 13 includes a light guide plate 60, a lens sheet 61 provided on the surface of the light guide plate 60, and a cold cathode tube (rod light source 62) disposed below the light guide plate 60.

  The rear surface of the light guide plate 60 is formed in a prism shape. This prism shape is repeatedly formed so as to be aligned in a certain direction. As a material constituting the light guide plate 60, a transparent resin material such as a polycarbonate resin or an epoxy resin can be used in addition to an acrylic resin.

  The lens sheet 61 is provided on the surface of the light guide plate 60 so that light from the light guide plate 60 enters. The lens sheet 61 is configured by forming a plurality of cones made of an acrylic resin or the like on a base made of a polyester film or the like.

  The rod-shaped light source 62 is a linear light source formed in a rod shape. The rod-shaped light sources 62 are arranged in parallel in a certain direction below the light guide plate 60.

(Manufacturing method of the liquid crystal display device 10)
Next, a manufacturing method of the liquid crystal display device 10 according to the embodiment of the present invention will be described in detail.

  First, first and second glass substrates each having a thickness of about 0.7 mm are prepared.

  Next, on the first glass substrate, for example, a TFT array using low-temperature polysilicon as an active layer, a pixel electrode, a display driver IC 40, and the like are formed. At this time, the pixel electrode is formed in the display area 31 of the liquid crystal display panel 11 and the display driving driver IC 40 is formed to extend to the end of the first glass substrate with a predetermined distance from the display area 31. 11 are formed around the display area 31.

  Subsequently, a sealing material is applied and formed in a frame shape so as to surround the display region 31. The sealing material is drawn by a dispenser using, for example, an epoxy adhesive. At this time, the connection electrode portion extends to the outside of the sealing material.

  Next, on the second glass substrate, for example, a counter electrode made of ITO, a color filter, and the like are formed at positions corresponding to the display region 31.

  Next, a predetermined amount of liquid crystal molecules is dropped onto a region surrounded by the sealing material on the first glass substrate.

  Next, the first and second glass substrates are positioned and pressed at a predetermined pressure so that the display area 31 on the first glass substrate and the counter electrode on the second glass substrate are opposed to each other. After bonding, the sealing material is cured and bonded.

  Next, the first and second glass substrates are polished and thinned by etching or the like so that the thickness thereof is, for example, 0.2 mm or less.

  Next, if necessary, the bonded substrate made of the first and second glass substrates is cut into a predetermined size. For example, by using a harmonic UV-YAG laser for cutting, the cut surface can be made smooth to prevent cracks in the glass substrate. The cutting is not limited to the laser, and a mechanical cutting method may be used.

  Next, a polarizing plate having a thickness of, for example, 0.35 mm is bonded to the surface of the bonded substrate through an adhesive layer, and the liquid crystal display panel 11 configured by bonding the TFT substrate 20 and the CF substrate 21 is manufactured. .

  Next, the side end portion of the flexible printed circuit board 12 is connected between the IC mounting area 30 and the display area 31 in the overhang area 33 of the TFT substrate 20 by an anisotropic conductive film. At this time, the surface of the flexible printed circuit board 12 connected to the FPC connection area 32 faces the TFT substrate 20 and extends toward the display area 31, and the elements 50 such as the mounted wiring and electronic components are mounted. Are connected along the display driver IC 40.

  Next, a light guide plate 60 provided with a lens sheet 61 on the front surface is prepared, and a rod-like light source 62 is arranged below the light guide plate 60 to form a backlight 13 unit, which is used as the back surface of the liquid crystal display panel 11 (TFT substrate 20). The liquid crystal display device 10 is manufactured.

  In the present embodiment, a TFT type liquid crystal display panel is used as the liquid crystal display panel 11. However, the present invention is not limited to this. For example, the STN type liquid crystal display panel 11 constituting a passive matrix display is used. Also good.

  Further, in the present embodiment, the display device related to an LCD (liquid crystal display) is shown, but PD (plasma display), PALC (plasma addressed liquid crystal display) is shown. ), Organic EL (organic electroluminescence), inorganic EL (inorganic electroluminescence), FED (field emission display), or SED (surface-conduction electron-emitter display) It may be.

(Function and effect)
Next, operational effects will be described.

  The liquid crystal display device 10 according to this embodiment includes a TFT substrate 20 having an IC mounting region 30 on which a display driver IC 40 is mounted and a display region 31 for forming a display unit, and an IC mounting region 30 on the TFT substrate 20. And a flexible printed circuit board 12 connected to an FPC connection area 32 between the display area 31 and the flexible printed circuit board 12, the surface of the flexible printed circuit board 12 connected to the TFT substrate 20 being a substrate It is provided to extend to the display area 31 side.

  According to such a configuration, the flexible printed circuit board 12 provided on the TFT substrate 20 is electrically connected to the display driving driver IC 40 on the TFT substrate 20, and the inside of the TFT substrate 20 (display) from the connection region. It is provided to extend to the region 31 side). For this reason, it is not necessary to take a dividing margin and a mounting margin of the flexible printed circuit board with respect to the bending as in the conventional structure in which the flexible printed circuit board is extended outward, bent from there, and pulled back toward the apparatus. Therefore, manufacturing efficiency is improved. Moreover, since the flexible printed circuit board can be accommodated inside the apparatus without being bent, the thickness of the bent portion of the flexible printed circuit board does not occur. For this reason, the liquid crystal display device can be miniaturized.

  In the liquid crystal display device 10 according to the present embodiment, the thickness of the CF substrate 21 may be twice or less that of the flexible printed circuit board 12.

  According to such a configuration, in the liquid crystal display device 10 composed of the two substrates 20 and 21 facing each other, the flexible printed circuit board 12 provided on the TFT substrate 20 is replaced with the CF substrate provided in the display region 31. It is pulled out without being bent on 21 and rides on the CF substrate 21. At this time, since the thickness of the CF substrate 21 is not more than twice that of the flexible printed circuit board 12, the level difference generated when the flexible printed circuit board 12 rides on the CF substrate 21 is reduced. Therefore, it is possible to suppress the flexible printed board 12 from being damaged by rubbing with the CF board 21 at the step.

  Furthermore, in the liquid crystal display device 10 according to the present embodiment, the display driving driver IC 40 is provided so as to extend along one side of the TFT substrate 20, and the flexible printed circuit board 12 is provided with a plurality of elements 50. The plurality of elements 50 may be provided so as to extend along the display drive driver IC 40 on the flexible printed circuit board 12.

  According to such a configuration, since the plurality of elements 50 of the flexible printed circuit board 12 are provided so as to extend along the display driving driver IC 40, the area of the flexible printed circuit board 12 extending in the direction extending to the display region 31 is reduced. can do. Accordingly, a reduction in display area can be suppressed.

  As described above, the present invention is useful for display devices.

1 is a cross-sectional view of a liquid crystal display device 10 according to an embodiment of the present invention. 1 is a plan view of a liquid crystal display device 10 according to an embodiment of the present invention. 4 is a cross-sectional view of an overhang region 33 in the TFT substrate 20 of the liquid crystal display device 10 according to the embodiment of the present invention. FIG. It is a top view of the conventional common liquid crystal display device. It is sectional drawing of the protrusion area | region 33 in the TFT substrate 101 of the conventional common liquid crystal display device 100. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Liquid crystal display device 11 Liquid crystal display panel 12 Flexible printed circuit board 13 Backlight 20 TFT substrate 21 CF board 30 IC mounting area 31 Display area 32 FPC connection area 33 Overhang area 40 Driver IC for display drive
50 element 60 light guide plate 61 lens sheet 62 rod-shaped light source

Claims (3)

A substrate having an IC mounting area on which a display driver IC is mounted and a display area for forming a display unit;
A flexible printed circuit board connected to an FPC connection area between the IC mounting area and the display area on the board;
A display device comprising:
The flexible printed circuit board is a display device provided such that a surface connected to the substrate faces the substrate and extends toward the display region. The display device according to claim 1,
In addition to having another substrate provided to face the substrate in the display area on the substrate,
The other substrate is a display device whose thickness is twice or less that of the flexible printed circuit board. The display device according to claim 1,
The display driving driver IC is provided so as to extend along one side of the substrate,
The flexible printed circuit board is provided with a plurality of elements on at least one surface,
The display device, wherein the plurality of elements are provided so as to extend along the display driving driver IC on the flexible printed board.

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