JP2009300659A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device which suppresses generation of EMI (Electro Magnetic Interference) noise and has a good display quality. <P>SOLUTION: In the display device 10, a GND (Ground) electrode 18 of a source substrate 22 is exposed in a prescribed portion of the source substrate 22, and a TCP (tape Carrier Package) 16 connected to the source substrate 22 is bent at 180° and a drive circuit 20 of the TCP 16 is provided on an exposed portion of the GND electrode 18, so that the GND electrode 18 and the drive circuit 20 are electrically connected. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display device.

  In general, a display device includes a display panel in which a thin film transistor substrate and a counter substrate are bonded to each other and a display medium layer is sandwiched between the substrates. With such a configuration, the amount of transmitted light is controlled according to the potential difference applied between the pixel electrode formed on the thin film transistor substrate and the common electrode formed on the counter substrate, and an image with a predetermined gradation is displayed on the display screen. Can be displayed. A driving circuit is electrically connected to the thin film transistor substrate in order to apply a voltage to both electrodes and hold the predetermined voltage in a predetermined pixel.

  In recent years, such display devices have been required to be thinner and smaller, and accordingly, circuit members constituting the drive circuit of the display device are also required to be thinner and smaller. Yes.

  From such a background, for example, a mounting method called TCP (Tape Carrier Package) as disclosed in Patent Document 1 has been developed. Here, FIG. 9 shows a plan view of the display device 100 configured by the conventional TCP mounting method. FIG. 10 is an enlarged plan view of the TCP 103 in FIG.

The display device 100 includes a display panel 101 and a printed circuit board 102 such as a source substrate, and these are connected by a TCP 103 constituted by a drive circuit 105 and a flexible flexible plastic substrate 104 such as polyimide. . A connection terminal 106 on the display panel 101 side and a connection terminal 107 on the printed circuit board 102 side are formed in the TCP 103.
JP 2006-23589 A

  As in the display device 100 shown in FIG. 9, in the configuration in which the drive circuit 105 is TCP-mounted and thereby the display panel 101 and the printed circuit board 102 are connected, digital signals such as a clock signal and an image data signal are The signal is input to the drive circuit 105 through a signal line wired on the printed circuit board 102.

  As described above, since the circuit member is required to be thin and small, the printed circuit board 102 is formed in an elongated thin plate-like rectangular shape. For this reason, signal lines through which high-frequency (high-speed) digital signals of several tens of MHz pass are closely connected. Furthermore, the wiring area of the reference potential wiring (ground (GND) electrode wiring) of the printed circuit board 102 tends to be thin and small in area. In this manner, the thin and thin rectangular printed circuit board 102 cannot sufficiently absorb EMI (Electro Magnetic Interference) noise generated by the influence of a clock signal or the like input from the system side by the GND electrode wiring, There is a problem in that the noise is propagated to the peripheral circuits and the display quality is adversely affected.

  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 suppresses the generation of EMI noise and has good display quality.

  A display device according to the present invention includes a display panel including a plurality of source lines and a plurality of gate lines provided so as to cross the plurality of source lines, and a drive circuit connected to the display panel and driving the display panel. And a printed circuit board that is connected to the TCP, inputs an external signal to the drive circuit, and is provided with a GND electrode, wherein the GND electrode of the printed circuit board is connected to the printed circuit board. The TCP electrode that is exposed at a predetermined portion and connected to the printed circuit board is bent 180 ° and the TCP drive circuit is provided on the exposed portion of the GND electrode, so that the GND electrode and the drive circuit are electrically connected. It is characterized by.

  Further, the display device according to the present invention is provided with a backlight on the back surface of the display panel, connected to the display panel and bent 180 °, and a GND electrode electrically connected to the TCP drive circuit And a printed circuit board provided with may be arranged on the side of the backlight.

  Further, in the display device according to the present invention, a bezel is provided around the display panel and the backlight, and the TCP and the printed circuit board disposed on the side of the backlight are pressed and fixed to the backlight side by the bezel. May be.

  In the display device according to the present invention, a conductive buffer member may be provided between the TCP drive circuit and the GND electrode of the printed circuit board.

  Furthermore, in the display device according to the present invention, the display panel may be a liquid crystal display panel.

  According to the present invention, it is possible to provide a display device that suppresses generation of EMI noise and has good display quality.

  Hereinafter, a configuration of a display device and a manufacturing method thereof according to an embodiment of the present invention will be described in detail with reference to the drawings. A liquid crystal display device will be described as an example of the display device. The present invention is not limited to the following embodiment.

(Embodiment 1)
(Configuration of the liquid crystal display device 10)
FIG. 1 is a sectional view of a liquid crystal display device 10 according to Embodiment 1 of the present invention. The liquid crystal display device 10 includes a liquid crystal display panel 11, a TCP 16, a source substrate 22 (printed circuit substrate), a backlight 12, and a bezel 15.

  The liquid crystal display panel 11 includes a thin film transistor substrate 13 on which a plurality of thin film transistors and the like are formed, a color filter substrate 14 that is disposed to face the thin film transistor substrate 13 and on which color filters and the like are formed, and the thin film transistor substrate 13 and the color filter substrate 14. And a liquid crystal layer provided therebetween.

  The thin film transistor substrate 13 and the color filter substrate 14 are formed in, for example, a rectangular shape and are not shown in the figure, but an alignment film is provided on the surface on the liquid crystal layer side and a polarizing plate on the surface opposite to the liquid crystal layer. Are provided. A frame-shaped sealing material made of epoxy resin or the like is disposed between the thin film transistor substrate 13 and the color filter substrate 14, and a liquid crystal material is sealed inside the sealing material, thereby forming a liquid crystal layer. Has been.

  Although not shown, the thin film transistor substrate 13 is provided in a region constituting the display portion so that a plurality of source lines and a plurality of gate lines extend so as to intersect with each other. Each of the thin film transistors is provided in a portion. Further, a plurality of pixel electrodes respectively connected to the thin film transistors are formed in a matrix on the thin film transistor substrate 13.

  The thin film transistor substrate 13 includes an excess region 21 provided by being formed in a larger area than the color filter substrate 14.

  In the surplus region 21, a plurality of lead wires drawn from the source line are formed, and the lead wires are electrically connected to the plurality of terminal pads on the surplus region 21.

  The TCP 16 is electrically connected to the terminal pad of the surplus region 21 through, for example, an anisotropic conductive film in which conductive particles are dispersed in an insulating adhesive.

  The TCP 16 includes an insulating film substrate 19 made of, for example, polyimide or polyethylene terephthalate, and the wiring formed on the surface of the film substrate 19 with a copper foil wire, a terminal on the liquid crystal display panel 11 side, and a source substrate 22. Side terminals are formed respectively. A drive circuit 20 electrically connected to the wiring is formed on the film substrate 19 of the TCP 16.

  The drive circuit 20 of the TCP 16 is composed of, for example, a source driver and a timing controller, and transmits an external signal or the like from the source substrate 22 to the liquid crystal display panel 11. The drive circuit 20 is formed in a substantially rectangular parallelepiped having a surface made of a conductive member.

  The source substrate 22 is configured by mounting various IC chips on an insulating substrate 17 formed of glass or resin. On the source substrate 22, a GND electrode 18 for defining a GND potential is formed in a pattern. As shown in FIG. 2, a plurality of rectangular openings 29 are formed in parallel on the surface of the source substrate 22, and the GND electrodes 18 patterned in the source substrate 22 are formed from the openings 29. Is exposed. The end portion of the film substrate 19 of the TCP 16 described above is connected to the back surface end portion of the source substrate 22, and the GND electrode 18 exposed on the surface of the source substrate 22 is further connected to the TCP 16 by bending the film substrate 19 by 180 °. The drive circuit 20 is in contact with the surface. Thereby, the GND electrode 18 of the source substrate 22 and the drive circuit 20 of the TCP 16 are electrically connected.

  The GND electrode 18 of the source substrate 22 and the drive circuit 20 of the TCP 16 may be in direct contact as described above, or a buffer such as a gasket in which a flexible resin member or the like is covered with a conductive film or the like. Members may be provided between them for electrical connection.

  The TCP 16 connected to the liquid crystal display panel 11 and bent 180 ° as described above, and the source substrate 22 provided with the GND electrode 18 electrically connected to the drive circuit 20 of the TCP 16 are the back surface of the thin film transistor substrate 13. The source substrate 22 is provided so as to overlap the side of the backlight 12 provided at the side so that the source substrate 22 is located on the backlight 12 side and the TCP 16 is located outside.

  The bezel 15 is disposed around the liquid crystal display panel 11 and the backlight 12, and is formed in a frame shape using a metal member or a resin member. As described above, the bezel 15 presses and fixes the TCP 16 and the source substrate 22 disposed on the side of the backlight 12 to the backlight 12 side.

(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. The following manufacturing method is merely an example, and the liquid crystal display device 10 according to the present invention is not limited to the one manufactured by the following method.

  First, an insulating substrate made of two pieces of glass or resin each having a thickness of, for example, about 0.4 mm is prepared. Next, on one insulating substrate, a plurality of source lines and a plurality of gate lines are provided so as to extend so as to cross each other, and a thin film transistor is formed at an intersection of each of these source lines and each gate line. Further, a pixel electrode is formed corresponding to each thin film transistor. In addition, a plurality of lead-out wires led out from the source lines and a plurality of terminal pads electrically connected to the lead-out wires are formed in a portion (rear surplus region 21) that is exposed when bonded to the color filter substrate 14. A thin film transistor substrate 13 is prepared.

  Next, a sealing material is applied and formed in a frame shape so as to surround the display region of the thin film transistor substrate 13. The sealing material is drawn by a dispenser using, for example, an epoxy adhesive. Next, on the other insulating substrate, for example, a counter electrode made of ITO, a color filter, and the like are formed, and the color filter substrate 14 is manufactured. Next, a predetermined amount of liquid crystal molecules is dropped onto a region surrounded by the sealing material on the thin film transistor substrate 13.

  Next, as shown in FIG. 3, the substrates are positioned and arranged so that the display area on the thin film transistor substrate 13 and the counter electrode on the color filter substrate 14 are opposed to each other, and are pressed with a predetermined pressure by a sealing material. After bonding, the sealing material is cured and bonded. Next, if necessary, the bonded substrate including the thin film transistor substrate 13 and the color filter substrate 14 is cut into a predetermined size. Further, the thin film transistor substrate 13 is formed in a larger area than the color filter substrate 14, and an excess region 21 is provided. Subsequently, a front polarizing plate and a rear polarizing plate having a thickness of, for example, 0.35 mm are bonded to the front and back surfaces of the bonded substrate, respectively, via an adhesive layer.

  Next, as shown in FIG. 4, the TCP 16 provided with the drive circuit 20 is electrically connected to the terminal pad of the surplus region 21 of the thin film transistor substrate 13 through an anisotropic conductive film. At this time, the TCP 16 is connected to the thin film transistor substrate 13 so that the drive circuit 20 faces the back side of the thin film transistor substrate 13.

  Subsequently, the GND electrode 18 is patterned, and a plurality of rectangular openings 29 are formed in parallel on the surface of the insulating substrate 17. The GND is patterned from the openings 29 into the insulating substrate 17. A source substrate 22 with the electrode 18 exposed is prepared.

  Next, as shown in FIG. 5, the source substrate 22 is electrically connected so that the exposed GND electrode 18 faces the back side of the thin film transistor substrate 13 at the end of the TCP 16 opposite to the thin film transistor substrate 13. .

  Subsequently, as shown in FIG. 6, the film substrate 19 of the TCP 16 is bent by 180 ° so that the GND electrode 18 exposed on the surface of the source substrate 22 is brought into contact with the surface of the drive circuit 20 of the TCP 16. TCP16 is arrange | positioned to the side of the backlight 12 planned installation position.

  Next, as shown in FIG. 7, the backlight 12 is provided on the back side of the thin film transistor substrate 13. Subsequently, a bezel 15 is provided around the liquid crystal display panel 11 and the backlight 12, and the TCP 16 and the source substrate 22 disposed on the side of the backlight 12 are pressed and fixed to the backlight 12 by the bezel 15. Thus, the liquid crystal display device 10 is completed.

(Embodiment 2)
Next, the liquid crystal display device 30 according to the second embodiment of the present invention will be described. The liquid crystal display device 30 is different from the first embodiment in the connection and arrangement configuration of the TCP 36 and the source substrate 42, and the configuration of each component itself is the same as that in the first embodiment.

  FIG. 8 is a cross-sectional view of the liquid crystal display device 30 according to the second embodiment of the present invention. The liquid crystal display device 30 includes a liquid crystal display panel 31, a TCP 36, a source substrate 42 (printed circuit board), a backlight 32, and a bezel 35.

  The liquid crystal display panel 31 includes a thin film transistor substrate 33 and a color filter substrate 34. The thin film transistor substrate 33 includes a surplus region 41 provided by being formed in a larger area than the color filter substrate 34.

  The TCP 36 is electrically connected to the surplus region 41 through an anisotropic conductive film. The TCP 36 includes a film substrate 39, and wirings formed of copper foil wires or the like, a liquid crystal display panel 31 side terminal, and a source substrate 42 side terminal are formed on the surface of the film substrate 39. A drive circuit 40 electrically connected to the wiring is formed on the film substrate 39 of the TCP 36.

  The source substrate 42 is configured by mounting various IC chips on an insulating substrate 37 formed of glass or resin. On the source substrate 42, a GND electrode 38 for defining the GND potential is patterned. A plurality of rectangular openings 49 are formed in parallel on the surface of the source substrate 42, and the GND electrode 38 patterned in the source substrate 42 is exposed from the openings 49. The end of the film substrate 39 of the TCP 36 described above is connected to the back surface end of the source substrate 42, and the GND electrode 38 exposed on the surface of the source substrate 42 is further connected to the TCP 36 by bending the film substrate 39 by 180 °. The drive circuit 40 is in contact with the surface. Thereby, the GND electrode 38 of the source substrate 42 and the drive circuit 40 of the TCP 36 are electrically connected.

  Note that the GND electrode 38 of the source substrate 42 and the drive circuit 40 of the TCP 36 may be in direct contact as described above, or a buffer such as a gasket in which a flexible resin member or the like is covered with a conductive film or the like. Members may be provided between them for electrical connection.

  The TCP 36 that is connected to the liquid crystal display panel 31 and bent 180 ° as described above, and the source substrate 42 that is provided with the GND electrode 38 that is electrically connected to the drive circuit 40 of the TCP 36 is the back surface of the thin film transistor substrate 33. The TCP 36 is provided on the side of the backlight 32 provided in the stack so that the TCP 36 is positioned on the backlight 32 side and the source substrate 42 is positioned on the outside.

  The bezel 35 is disposed around the liquid crystal display panel 31 and the backlight 32. As described above, the bezel 35 presses and fixes the TCP 36 and the source substrate 42 disposed on the side of the backlight 32 to the backlight 32 side.

  In the present embodiment, a display device related to an LCD (liquid crystal display) has been described. However, the display device is not limited to this, and for example, an organic EL (organic electro luminescence) or an inorganic EL (inorganic electro luminescence). Electrophoretic, PD (plasma display), PALC (plasma addressed liquid crystal display), FED (field emission display), or SED (surface-conduction electron-) It may be a display device related to an emitter display (surface electric field display) or the like.

(Function and effect)
Next, functions and effects of the liquid crystal display devices 10 and 30 according to the embodiment of the present invention will be described.

  In the liquid crystal display devices 10 and 30 according to the embodiment of the present invention, the GND electrodes 18 and 38 of the source substrates 22 and 42 are exposed at the openings 29 and 49 of the source substrates 22 and 42 and connected to the source substrates 22 and 42. The TCPs 16 and 36 are bent 180 ° and the drive circuits 20 and 40 of the TCPs 16 and 36 are provided on the exposed portions of the GND electrodes 18 and 38, so that the GND electrodes 18 and 38 and the drive circuits 20 and 40 are electrically connected. It is connected.

  According to such a configuration, the GND electrodes 18 and 38 of the source substrates 22 and 42 and the drive circuits 20 and 40 of the TCPs 16 and 36 are brought into direct contact without being connected to each other and are electrically connected. , 42, EMI (Electro Magnetic Interference) generated due to the influence of a clock signal or the like input from the system side is satisfactorily suppressed. Therefore, the display quality of the liquid crystal display devices 10 and 30 is improved.

  In addition, a wiring region for electrically connecting the GND electrodes 18 and 38 of the source substrates 22 and 42 and the drive circuits 20 and 40 of the TCPs 16 and 36 is not required, and the source substrates 22 and 42 can be formed more compactly. It becomes. For this reason, the liquid crystal display devices 10 and 30 as a whole can be made smaller.

  Further, the source substrate 22 provided with the TCPs 16 and 36 bent by 180 ° connected to the liquid crystal display panels 11 and 31 and the GND electrodes 18 and 38 electrically connected to the drive circuits 20 and 40 of the TCPs 16 and 36. , 42 are arranged on the sides of the backlights 12, 32, so that the TCPs 16, 36 and the source substrates 22, 42 can be accommodated in a compact manner, and the liquid crystal display devices 10, 30 can be made smaller. be able to.

  Further, since the TCPs 16 and 36 and the source substrates 22 and 42 disposed on the sides of the backlights 12 and 32 are pressed and fixed to the backlights 12 and 32 by the bezels 15 and 35, the TCPs 16 and 36 and the source substrates 22. , 42 can be provided more compactly and stably without causing positional displacement.

  If a conductive buffer member is provided between the drive circuits 20 and 40 of the TCPs 16 and 36 and the GND electrodes 18 and 38 of the source substrates 22 and 42, the drive circuit 20 is directly connected to the hard GND electrodes 18 and 38. , 40 can be satisfactorily prevented from damaging the drive circuits 20, 40 due to contact.

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

1 is a cross-sectional view of a liquid crystal display device according to Embodiment 1. FIG. It is a top view of TCP provided with the source substrate provided with the GND electrode exposed by the opening part, and the drive circuit which contacts a GND electrode. It is sectional drawing of the liquid crystal display panel in the manufacturing process of a liquid crystal display device. It is sectional drawing of the liquid crystal display panel to which TCP was connected in the manufacturing process of a liquid crystal display device. It is sectional drawing of the liquid crystal display panel with which the source substrate in the manufacturing process of a liquid crystal display device was connected to TCP. It is sectional drawing of the liquid crystal display panel by which the source substrate and TCP in the manufacturing process of a liquid crystal display device are arrange | positioned to the side of the backlight installation scheduled position. It is sectional drawing of the liquid crystal display panel and backlight in the manufacturing process of a liquid crystal display device. 6 is a cross-sectional view of a liquid crystal display device according to Embodiment 2. FIG. It is a top view of the display apparatus comprised by the conventional TCP mounting system. FIG. 10 is an enlarged plan view of the TCP in FIG. 9.

Explanation of symbols

10, 30 Liquid crystal display device
11, 31 LCD panel
12, 32 Backlight
15, 35 bezel
16, 36 TCP
18,38 GND electrode
20, 40 drive circuit
22, 42 Source substrate
29,49 opening

Claims (5)

A display panel comprising a plurality of source lines and a plurality of gate lines provided to cross the plurality of source lines, respectively;
TCP connected to the display panel and having a drive circuit for driving the display panel;
A printed circuit board connected to the TCP, for inputting an external signal to the drive circuit, and provided with a GND electrode;
A display device comprising:
The GND electrode of the printed circuit board is exposed at a predetermined portion of the printed circuit board, and the TCP connected to the printed circuit board is bent by 180 ° to provide the TCP drive circuit on the exposed portion of the GND electrode. Accordingly, the display device in which the GND electrode and the drive circuit are electrically connected. The display device according to claim 1,
A backlight is provided on the back of the display panel.
A TCP connected to the display panel and bent by 180 ° and a printed circuit board provided with the GND electrode electrically connected to the drive circuit of the TCP are arranged on the side of the backlight. Display device. The display device according to claim 2,
A bezel is provided around the display panel and the backlight.
The display device in which the TCP and the printed circuit board disposed on the side of the backlight are pressed and fixed to the backlight side by the bezel. The display device according to claim 1,
A display device in which a conductive buffer member is provided between the TCP drive circuit and the GND electrode of the printed circuit board. The display device according to claim 1,
The display device is a liquid crystal display panel.

Images