JP2004118089A - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display in which an auxiliary capacitance signal can be sent without delay to the input line for auxiliary capacitance signals, the input line separated from a FPC (flexible printed circuit) and present in the opposite side to the FPC over the display part, without disposing a plurality of FPCs. <P>SOLUTION: The liquid crystal display apparatus 100 is equipped with a square liquid crystal panel having a plurality of auxiliary capacitance lines and with an FPC 120 attached to the end of the liquid crystal panel 110 along one side line thereof. The liquid crystal panel 110 is provided with an input line 117 for auxiliary capacitance signals in the opposite side to the FPC 120 over the display part D. The FPC 120 includes: an FPC main body 121 attached to the end of the panel 110 along one side line of the panel 110; and an extended part 122 which is extended along the adjoining side lines of the side to which the FPC main body 121 is attached, and which is connected to the input line for auxiliary capacitance signals. The FPC is attached to only one side end of the liquid crystal panel while a FPC is not attached to each of the plurality of the side lines of the liquid crystal panel. However, the auxiliary capacitance signal can be sent without delay into the input line for auxiliary capacitance signals, the input line separated from the FPC main body and present in the opposite side to the FPC main body side over the display part. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a first substrate having a plurality of auxiliary capacitance lines, a second substrate provided to face the first substrate, and a liquid crystal layer provided to be sandwiched between the first and second substrates. The present invention relates to a liquid crystal display device comprising: a rectangular liquid crystal panel having the following formula: and a flexible printed circuit (FPC), which is attached along one side of the liquid crystal panel.
[0002]
[Prior art]
An active matrix liquid crystal display device includes an active matrix substrate, a counter substrate provided to face the active matrix substrate, and a liquid crystal layer provided to be sandwiched between the two substrates. It has a liquid crystal panel. In such a liquid crystal display device, an IC for driving a liquid crystal and an FPC for inputting a signal for operating the IC for driving the liquid crystal and a control signal directly to the liquid crystal panel are usually mounted on the liquid crystal panel.
[0003]
As a mounting structure of a liquid crystal driving IC, a mounting structure using a TCP (Tape Carrier Package) has been generally known. However, in recent years, from the viewpoint of low cost, high reliability, and thinness, a liquid crystal driving IC has been used. Some devices using a COG (Chip On Glass) system in which an IC is mounted on a liquid crystal panel with a bare chip are becoming available. Among them, a connection method is generally used in which a projection-like bump is formed on an electrode of a liquid crystal driving IC, and a liquid crystal panel and the liquid crystal driving IC are face-down bonded.
[0004]
As an example of such a configuration, Japanese Patent Application Laid-Open No. H11-163,097 discloses a method in which a driver is mounted by COG on a glass substrate of a liquid crystal display device, a double-sided FPC is arranged so as to surround the periphery of the glass substrate, and the double-sided FPC is connected. A technique is disclosed in which two L-shaped circuit boards are superimposed on a portion other than the display portion of a liquid crystal display device, thereby increasing the wiring resistance due to the miniaturization of the wiring on the liquid crystal display device and transmitting a drive signal to the liquid crystal display device. It is described that an increase in the area of the apparatus due to the extension of the FPC used for supplying is suppressed.
[0005]
Hereinafter, a conventional liquid crystal display device 100 'in which a liquid crystal driving IC is face-down bonded to a liquid crystal panel by a COG method will be described with reference to a schematic plan view of FIG.
[0006]
The liquid crystal panel 110 'of the liquid crystal display device 100' includes a liquid crystal driving source IC 113 'and a liquid crystal driving gate IC 114 along each of two mutually adjacent sides of the liquid crystal panel 110' outside the display section D '. In addition, an FPC 120 ′ is attached to one side of the liquid crystal panel 110 ′ along one side of the liquid crystal driving source IC 113 ′, and the FPC connection terminal portion 120 a ′ of the FPC 120 ′ is provided. It is electrically connected to an FPC connection terminal provided on the liquid crystal panel 110 '. The connection process of the liquid crystal driving source IC 113 ′, the liquid crystal driving gate IC 114 ′, and the FPC 120 ′ is as follows. First, an anisotropic conductive film (not shown) called an ACF (Anisotropic Conductive Film) is crimped to the liquid crystal panel 110 ′. Then, a method is generally adopted in which the IC 113 ′ for the liquid crystal driving source and the like are heated and pressed on the liquid crystal panel 110 ′ with a tool head having a pressing mechanism and a heating mechanism. The liquid crystal panel 110 'has a picture element configuration (not shown) in which storage capacitors are connected on a common bus line, and the common bus line is provided around the display section D' of the liquid crystal panel 110 '. Short-circuited to the connected auxiliary capacitance / counter signal input wiring 117 '. The FPC 120 'sends a power supply and an input signal to the liquid crystal driving source IC 113' and the liquid crystal driving gate IC 114 ', respectively, and sends an auxiliary capacitance / opposite signal to the auxiliary capacitance / opposite signal input wiring 117'. And wiring for the connection.
[0007]
[Patent Document 1]
Published Japanese Utility Model Application No. 5-29030
[Problems to be solved by the invention]
By the way, in recent years, as the display screen of the COG type liquid crystal display device 100 ′ has become larger and higher definition, the power supply and the delay of the input signal to the liquid crystal drive gate IC 114 ′ which is far from the FPC 120 ′ have been delayed. In addition, the delay of the control signal input via the storage capacitor / opposite signal input wiring 117 'has become an issue. Among them, the problem of delay of the power supply and the input signal to the liquid crystal drive gate IC 114 'can be avoided by adopting low resistance wiring and devising the drive method (picture element configuration). However, it is impossible to avoid the problem of signal delay input to the auxiliary capacitance line from the auxiliary capacitance / opposite signal input wiring 117 'on the opposite side to the FPC 120' side via the display unit D '. Will be reduced.
[0009]
As shown in FIG. 4, if the FPC 120 'is attached to two sides of the liquid crystal panel 110' corresponding to the liquid crystal driving source IC 113 'and the liquid crystal driving gate IC 114', respectively, the storage capacitor / counter signal input wiring 117 is provided. The problem of delay of the signal input to the auxiliary capacitance line from the 'is solved, and the display quality becomes no problem. However, in this case, a wiring for supplying a data signal or a gate signal to the display unit D ', an output bonding pad short-circuited to the wiring, a wiring on any side of the liquid crystal panel 110' on which the FPC 120 'is mounted, An area where an input wiring for inputting a signal and power to the liquid crystal driving source IC 113 ′ or the liquid crystal driving gate IC 114 ′, an input bonding pad short-circuited to the input wiring, an FPC input terminal for connecting the FPC 120 ′, and the like are provided. Need to be secured. Therefore, as shown in FIGS. 3 and 4, the FPC 120 ′ is attached to two mutually adjacent sides of the liquid crystal panel 110 ′, rather than the COG area width A when the FPC 120 ′ is attached to one side of the liquid crystal panel 110 ′. There is a problem that the COG region width A 'when each is attached is larger, and a narrower frame cannot be achieved, and a liquid crystal display module with high added value cannot be supplied.
[0010]
The present invention has been made in view of such a point, and an object of the present invention is to dispose an FPC only on one side of a liquid crystal panel, but use an FPC on a side opposite to the FPC through a display unit. It is an object of the present invention to provide a liquid crystal display device capable of transmitting an auxiliary capacitance signal to a separated auxiliary capacitance signal input wiring without delay.
[0011]
[Means for Solving the Problems]
According to the present invention, the FPC is provided with an extended portion extending along a side adjacent to the side on which the FPC of the liquid crystal panel is provided and connected to the auxiliary capacitance signal input wiring.
[0012]
Specifically, the present invention provides a first substrate having a plurality of auxiliary capacitance lines, a second substrate provided to face the first substrate, and a second substrate provided between the first and second substrates. A liquid crystal display device comprising: a rectangular liquid crystal panel having a liquid crystal layer provided; and an FPC attached to a side end along one side of the liquid crystal panel,
The liquid crystal panel is provided with an auxiliary capacitance signal input wiring to which a plurality of auxiliary capacitance lines of the first substrate are connected on a side opposite to the FPC side via a display unit,
The FPC includes an FPC main body attached to a side edge of the liquid crystal panel along one side thereof, and an auxiliary capacitance signal input wiring extending along a side adjacent to the side of the liquid crystal panel to which the FPC main body is attached. And an extension portion connected to the
[0013]
According to the above configuration, since the auxiliary capacitance signal can be sent to the auxiliary capacitance signal input wiring via the extension portion extending from the FPC main body, the FPC can be attached to each of the plurality of sides of the liquid crystal panel without mounting the FPC. Is attached to only one side edge of the liquid crystal panel, but sends an auxiliary capacitance signal without delay to the auxiliary capacitance signal input wiring separated from the FPC main body opposite to the FPC main body through the display unit Can be. Accordingly, by combining the problem of the delay of the power supply and the input signal by devising the low-resistance wiring and the driving method (picture element configuration), it is possible to achieve both high display quality and narrow frame.
[0014]
In the present invention, the FPC main body and the extension may be formed integrally. According to such a configuration, the number of connection points of the FPC may be small, so that the cost can be reduced by reducing the number of steps for connecting members and the number of members.
[0015]
In the present invention, the extension may be connected to only the auxiliary capacitance signal input wiring. According to such a configuration, the extension portion can be reduced to the minimum size, so that the cost can be reduced.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0017]
(Embodiment 1)
FIG. 1 shows a liquid crystal display device 100 according to Embodiment 1 of the present invention.
[0018]
The liquid crystal display device 100 includes an active matrix substrate (first substrate) 111, a counter substrate (second substrate) 112 provided opposite thereto, and a liquid crystal layer provided so as to be sandwiched between the two substrates. , And an FPC 120 attached to a side end along one long side of the liquid crystal panel 110.
[0019]
The active matrix substrate 111 of the liquid crystal panel 110 has a plurality of gate lines made of tantalum extending in parallel to the long side direction of the liquid crystal panel 110 on the inner surface of the insulating substrate made of glass, and each of the plurality of gate lines. And a plurality of auxiliary capacitance lines extending in parallel in the long side direction of the liquid crystal panel 110 between the gate lines are provided on the same layer. Further, a silicon nitride film is provided on the gate line and the auxiliary capacitance line, and a plurality of tantalum source lines extending in parallel in a short side direction of the liquid crystal panel 110 and a plurality of these source lines are provided thereon. And a source terminal connected to one end of each of them are provided on the same layer. That is, the gate lines and the source lines are provided so as to be orthogonally different from each other. The gate terminal and the source terminal are respectively connected to the electrode pads, and the gate terminal G (the right side of the liquid crystal panel 110 in FIG. 1) and the source terminal S (in FIG. 1) near the edge of the insulating substrate. The lower part of the liquid crystal panel 110 is formed.
[0020]
A thin film transistor is provided near each intersection between the plurality of gate lines and the plurality of source lines. In each region surrounded by the pair of gate lines and the pair of source lines, a pixel electrode made of ITO (Indium Tin Oxide), which is a transparent conductive film, is provided. This pixel electrode is connected to a source line and a gate line via a thin film transistor, respectively, and forms a storage capacitor by sandwiching a silicon nitride film as a dielectric between the pixel electrode and an auxiliary capacitor line.
[0021]
A protective film made of a silicon nitride film is provided on the thin film transistor, the source line, the gate line, the auxiliary capacitance line, and the pixel electrode, and an alignment film made of a rubbed polyimide is further provided thereon. Have been.
[0022]
On the opposite substrate 112 of the liquid crystal panel 110, a light-shielding film made of chromium and a color filter consisting of a color layer in which red, blue, and green pigments are dispersed in an acrylic resin are formed on the inner surface of an insulating substrate made of glass. A layer and an overcoat film made of an acrylic resin and covering the color filter layer are sequentially laminated. Further, a counter electrode made of ITO, which is a transparent conductive film, is provided on the overcoat film, and an alignment film made of rubbed polyimide is further provided thereon.
[0023]
The liquid crystal layer of the liquid crystal panel 110 is made of a nematic liquid crystal having electro-optical characteristics. The periphery of the liquid crystal layer is sealed by a seal member interposed between the two substrates. The seal member is provided along the contour of the counter substrate 112.
[0024]
A pair of liquid crystal driving source ICs 113 and a pair of liquid crystal driving gate ICs 114 are arranged in the source terminal portion S and the gate terminal portion G of the liquid crystal display panel 1 along the corresponding sides of the liquid crystal panel 110, respectively. Have been. The liquid crystal driving source IC 113 and the liquid crystal driving gate IC 114 have Au-plated bump electrodes (hereinafter referred to as bumps). The bumps are anisotropically formed on the electrode pads of the source terminal section S and the gate terminal section G. Are electrically connected via the conductive film. The anisotropic conductive film is obtained by dispersing conductive particles in an epoxy-based thermosetting insulating resin.
[0025]
The source terminal section S is provided with a source lead wiring 115 made of the same material as the source line, and one end of the source lead wiring 115 is connected to the electrode pad similarly to the source terminal. The bumps of the liquid crystal driving source IC 113 arranged in the source terminal section S are connected to the electrode pads to which the source terminals are connected, and also to the electrode pads to which the source wiring 115 is connected. The source wiring 115 extends toward the long side of the liquid crystal panel 110, and the other end forms an FPC connection terminal.
[0026]
Similarly, the gate terminal portion G is provided with a gate lead-out line 116 made of the same material as the gate line, and one end of the gate lead-out line 116 is connected to the electrode pad similarly to the gate terminal. I have. The bumps of the liquid crystal drive gate IC 114 arranged in the gate terminal portion G are connected to the electrode pad to which the gate terminal is connected and also to the electrode pad to which the gate routing wiring 116 is connected. The gate wiring 116 extends toward the long side of the liquid crystal panel 110, and the other end forms an FPC connection terminal.
[0027]
Outside the display section (display area) D where the pixel electrodes of the active matrix substrate 111 of the liquid crystal panel 110 are arranged in a matrix, an auxiliary capacitance / counter signal input wiring 117 is provided in an annular shape so as to surround the display section D. Have been. All auxiliary capacitance lines are electrically connected to the auxiliary capacitance / counter signal input wiring 117. The counter electrode is electrically connected to the storage capacitor / counter signal input wiring 117 via a carbon paste 118 interposed between the active matrix substrate 111 and the counter substrate 112. The storage capacitor / opposite signal input wiring 117 extends outward from both corners (lower right and lower left corners of the storage capacitor / opposite signal input wiring 117 in FIG. 1) adjacent to the source terminal portion S. , And its ends constitute FPC connection terminals. In addition, a wiring extends outward from one corner (the upper right corner of the storage capacitor / opposite signal input wiring 117 in FIG. 1) close to the gate terminal G, and the end constitutes an FPC connection terminal. ing. The wiring formed between the display section D and the source terminal section S is formed of tantalum in the same layer as the gate line, and the wiring formed between the display section D and the gate wiring is formed in the same layer as the source line. Is formed from tantalum.
[0028]
The FPC 120 is one in which a lead wiring made of copper foil is formed on a flexible base material such as a polyimide-based material, and the FPC main body 121 and the extension portion 122 are integrated. The FPC main unit 121 is provided along the outer side end of the liquid crystal driving source IC 113 in the source terminal unit S of the liquid crystal panel 110, and the FPC main unit side connection terminal unit 121a is connected to the source terminal unit S on the liquid crystal panel 110 side. Each FPC connection terminal is electrically connected via an anisotropic conductive film. The FPC main body side connection terminal portion 121a is connected to a routing line of the FPC main body 121. The extending portion 122 is formed in an elongated strip shape, and extends sideways from the FPC main body 121, bends at a right angle, extends along the short side of the liquid crystal panel 110, and again extends toward the liquid crystal panel 110. The extension-side connection terminal portion 122a at the tip is electrically connected to the FPC connection terminal of the gate terminal portion G via an anisotropic conductive film. . The extension portion side connection terminal portion 122a is connected to a lead wire of the extension portion 122.
[0029]
In the liquid crystal display device 100 having such a configuration, the gate signal is sequentially transmitted from the liquid crystal drive gate IC 114 to the gate line, whereby the thin film transistor of the pixel electrode 12 provided along the gate line to which the gate signal is transmitted is in a selected state. Then, a source signal is sent from the liquid crystal driving source IC 113 to the source line 6 to cause each pixel electrode 12 to hold a predetermined charge, thereby changing the alignment state of the liquid crystal molecules in the liquid crystal layer, thereby increasing the light transmittance. Is displayed by adjusting. A power supply, a gate signal, and a source signal are sent from the FPC main unit 121 of the FPC 120 to the liquid crystal drive gate IC 114 and the liquid crystal drive source IC 113. In addition, the auxiliary capacitance / opposite signal is sent from the FPC main body 121 to the storage capacitor / opposite signal input wiring 117 on the side close to the FPC main unit 121, and the extension unit 122 Sends an auxiliary capacity / counter signal.
[0030]
According to the liquid crystal display device 100 having the above configuration, the auxiliary capacitance / opposite signal can be sent to the auxiliary capacitance / opposite signal input wiring 117 via the extension portion 122 extending from the FPC main body 121. It is unnecessary to attach the FPC 120 to each of the plurality of sides, and although the FPC 120 is attached only to one side of the liquid crystal panel 110, the FPC main body on the opposite side to the FPC main body 121 side via the display unit D The auxiliary capacitance / opposite signal can be sent to the portion of the auxiliary capacitance / opposite signal input wiring 117 separated from the portion 121 without delay.
[0031]
Further, since the FPC 120 is attached to only one side edge of the liquid crystal panel 110 and the COG area width A can be reduced, both high display quality and narrow frame can be achieved.
[0032]
Next, a method for manufacturing the liquid crystal display device 100 according to the embodiment will be described.
[0033]
<Active matrix substrate forming process>
First, after a tantalum thin film is formed on an insulating substrate by a sputtering method, a gate line, a gate electrode connected thereto, a gate terminal and an electrode pad connected to an end of the gate electrode, an auxiliary capacitance line are formed by a photolithographic method. The auxiliary capacitance / counter signal input wiring 117 (only the wiring on the source terminal side) and the source and gate lead wirings 115 and 116 are formed.
[0034]
Next, a silicon nitride film, an intrinsic amorphous silicon film (ia-Si film), and an n + amorphous silicon film (n + -a-Si film) doped with impurities are sequentially formed by a plasma CVD method. Only the lamination film of the ia-Si film and the n + -a-Si film is formed in an island pattern.
[0035]
Next, after a tantalum thin film is formed by stacking by a sputtering method, a source wiring, a source electrode connected thereto, a drain electrode, an auxiliary capacitor / counter signal input wiring 117 (however, a wiring on a gate terminal side) are formed by a photolithographic method. Only), a source terminal connected to the source line and an electrode pad are formed. At this time, the portion of the storage capacitor / opposite signal input wiring 117 on the gate terminal side is connected to the storage capacitor / opposite signal input wiring on the source terminal side via a contact hole formed in the silicon nitride film on the terminal portion of the supplementary capacitance line. 117 and a corner of the display section D are electrically connected. Here, the drain electrode and the source electrode overlap with the laminated film of the ia-Si film and the n + -a-Si film having the island pattern.
[0036]
Next, a thin film transistor is formed by etching the n + -a-Si film therebetween using the drain electrode and the source electrode as a mask.
[0037]
Next, ITO as a transparent conductive film is formed by a sputtering method, and a pixel electrode is formed by a photolithographic method. At this time, the pixel electrode is electrically connected to the drain electrode.
[0038]
Next, after a silicon nitride film and an alignment film made of polyimide are formed so as to be laminated by a plasma CVD method, a rubbing treatment is performed on the surface thereof.
[0039]
<Counter substrate forming step>
After a light-shielding film, a color filter layer, a counter electrode, and an alignment film made of polyimide are sequentially formed on an insulating substrate, a rubbing process is performed on the surface.
[0040]
<Liquid crystal panel forming process>
After a sealing material is formed over the active matrix substrate 111 by a printing method and the counter substrate 112 is attached thereto, liquid crystal is injected and sealed between the two substrates by a decompression method to form a liquid crystal layer.
[0041]
<Drive IC and FPC mounting process>
The liquid crystal driving source IC 113 is positioned on the electrode pad forming portion of the source terminal portion S of the liquid crystal panel 110 with an anisotropic conductive film interposed therebetween, and a heating tool is pressed from above the liquid crystal driving source IC 113 to about 180 ° C. Then, the bumps of the liquid crystal driving source IC 113 and the electrode pads are connected via the anisotropic conductive film. Similarly, the liquid crystal drive gate IC 114 is connected at the gate terminal portion G.
[0042]
Next, the FPC connection terminal portion 4 of the FPC main body portion 121 of the FPC 120 is connected to each FPC connection terminal of the source terminal portion S via an anisotropic conductive film. Similarly, the extension portion side connection terminal portion 122a of the extension portion 122 of the FPC 120 is connected to the FPC connection terminal of the source terminal portion S via an anisotropic conductive film.
[0043]
(Embodiment 2)
FIG. 2 shows a liquid crystal display device 100 according to Embodiment 2 of the present invention. In addition, in the liquid crystal display device 100 in which parts having the same names as those in the first embodiment are denoted by the same reference numerals, the FPC 120 has an FPC main body part 121 and an extension part 122 which are separate bodies. In other words, the base portion 122b of the extension portion 122 overlaps the FPC body 121, and is fixed to the FPC body 121 at the overlapping portion by bonding or the like.
[0044]
Other configurations, operations, and effects are the same as those of the first embodiment.
[0045]
【The invention's effect】
As described above, according to the present invention, the auxiliary capacitance signal can be sent to the auxiliary capacitance signal input wiring via the extension portion extending from the FPC, so that the FPC can be attached to each of a plurality of sides of the liquid crystal panel. However, although the FPC is attached only to one side of the liquid crystal panel, the auxiliary capacitance signal input wiring separated from the FPC main body on the opposite side to the FPC main body via the display unit without delay. Can be sent.
[Brief description of the drawings]
FIG. 1 is a plan view of a liquid crystal display device according to Embodiment 1 of the present invention.
FIG. 2 is a plan view of a liquid crystal display device according to Embodiment 2 of the present invention.
FIG. 3 is a plan view of a conventional liquid crystal display device.
FIG. 4 is a plan view of another conventional liquid crystal display device.
[Explanation of symbols]
100, 100 'Liquid crystal display device 110, 110' Liquid crystal panel 111 Active matrix substrate 112 Counter substrate 113, 113 'Liquid crystal driving source IC
114,114 'Liquid crystal drive gate IC
115 Leading wiring for source 116 Leading wiring for gate 117, 117 'Auxiliary capacitance / counter signal input wiring 118 Carbon paste 120, 120' FPC
120a 'connection terminal portion 121 FPC main body portion 121a FPC main body side connection terminal portion 122 extension portion 122a extension portion side connection terminal portion 122b base end portion D, D' display portion G gate terminal portion S source terminal portion

Claims (3)

A rectangle having a first substrate having a plurality of auxiliary capacitance lines, a second substrate provided to face the first substrate, and a liquid crystal layer provided to be sandwiched between the first and second substrates. A liquid crystal panel, and a flexible wiring board attached to a side edge along one side of the liquid crystal panel,
The liquid crystal panel is provided with an auxiliary capacitance signal input wiring to which a plurality of auxiliary capacitance lines of the first substrate are connected on a side opposite to the flexible wiring substrate side via a display unit,
The flexible wiring board extends along a side of the liquid crystal panel along a side thereof and a side adjacent to the side of the liquid crystal panel to which the flexible wiring board body is mounted. A liquid crystal display device comprising: an extension portion connected to the auxiliary capacitance signal input wiring. The liquid crystal display device according to claim 1,
A liquid crystal display device, wherein the flexible wiring board main body and the extending portion are integrally formed. The liquid crystal display device according to claim 1,
The liquid crystal display device, wherein the extension portion is connected only to the auxiliary capacitance signal input wiring.

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