JP2011221313A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost liquid crystal display device by eliminating the necessity for expensive components, such as a silver paste or a gold ball, that provide an electrical conduction between an array substrate and a counter substrate as well as a process of producing such components.SOLUTION: The display device comprises: a connection pad arranged outside a display area; a board arranged outside the display area; a connection electrode which is arranged on the board, abuts on a counter electrode, and is electrically connected to the connection pad.

Description

  The present invention relates to a conductive material for electrically connecting an array substrate and a counter substrate, and a display device and a manufacturing method for reducing the paste process.

  In recent years, a silver paste or gold ball is used in a conductive portion (hereinafter referred to as a transfer portion) of a liquid crystal display device in order to keep conduction between both the array substrate and the counter substrate and to maintain an arbitrary space (hereinafter referred to as a gap). For example, a technique of mixing an expensive conductive material with a sealing material or the like is used. However, since this technique increases the manufacturing cost, a technique for reducing the manufacturing cost by replacing the part with another material constituting the existing liquid crystal display device has been studied.

JP 2005-84231 A

  However, if a technique for mixing a conductive material such as silver paste or gold ball with a seal material or the like is not used, it becomes difficult to establish conduction at the transfer section, or the manufacturing process for gap management increases. There was a disadvantage in terms.

  The present invention includes a first substrate including a plurality of wirings and a plurality of pixel electrodes disposed on the wirings and constituting a display area, a second substrate including a counter electrode facing the pixel electrodes, In a display device comprising a columnar spacer disposed between the first substrate and the second substrate in the display region, the first substrate includes a connection pad disposed outside the display region, A display device comprising: a pedestal disposed outside the display region; and a connection electrode disposed on the pedestal and in contact with the counter electrode and electrically connected to the connection pad. The above-mentioned problem is solved by providing

  The present invention eliminates the need for an expensive silver paste or gold ball material for applying electrical continuity between the array substrate and the counter substrate, and a process for coating and forming them, thereby contributing to a reduction in manufacturing cost.

It is a perspective view which shows the display apparatus by this invention. It is an enlarged plan view showing a color filter on array type liquid crystal display device according to the present invention. FIG. 2 is an enlarged cross-sectional view taken along line AA of a color filter on array type liquid crystal display device according to the present invention. It is an enlarged plan view showing a liquid crystal display device according to the present invention having a color filter on a counter substrate. It is the expanded sectional view cut | disconnected along the AA line of the liquid crystal display device by this invention which has a color filter in a counter substrate.

  Embodiments of a liquid crystal display device according to the present invention will be described below with reference to the drawings. A color filter on array (hereinafter referred to as COA) type liquid crystal display device will be described as an example.

  An embodiment of a display device according to the present invention will be described with reference to FIGS. Moreover, the same part is shown with the same code | symbol.

  FIG. 1 is a perspective view showing a display device according to the present invention, and FIG. 2 is an enlarged plan view of a COA substrate of the display device of FIG. FIG. 3 is an enlarged sectional view taken along line AA of the liquid crystal display device according to the present invention of the color filter on array type.

  The liquid crystal display device includes a COA substrate (that is, a first substrate) 110 having a display region 25, a counter substrate (that is, a second substrate) 120 that is disposed opposite to the COA substrate 110 with a predetermined gap, and a display region 25. And a backlight unit 13 composed of an LED or the like serving as a light source is disposed on the lower surface of the COA substrate 110.

  The COA substrate 110 includes a substrate 10 made of glass or the like, a multilayer thin film formed on the substrate 10, and an alignment film (not shown) that does not interfere with the transfer unit 50 described later. On the substrate 10, a plurality of signal lines and scanning lines are arranged in a lattice pattern via multilayer thin films. Auxiliary capacitance lines are arranged along each scanning line, and are made of a transparent conductive material such as Indium-Tin-Oxide (hereinafter referred to as ITO) so as to substantially correspond to the pixel openings on the squares formed by the auxiliary capacitance lines and the signal lines. Pixel electrodes 30 constituting the display area 25 are provided.

  A switching element for controlling the pixel electrode 30 is formed at each intersection of the scanning line and the signal line, and an organic insulating film 24 which is a part of a multilayer thin film is coated on the switching element.

  The organic insulating film 24 is colored with one of R, G, and B resists to form a first colored layer 24a, a second colored layer 24b, and a third colored layer 24c.

  A pixel electrode 30 is disposed on each colored layer 24a, 24b, 24c. The pixel electrode 30 is electrically connected to the switching element through the through holes 15 formed in the colored layers 24a, 24b, and 24c.

  Here, a thin film transistor 14 (hereinafter referred to as TFT) composed of a gate electrode 14b, a source electrode 14a, and a drain electrode 14c is used as the switching element. The gate electrode 14b is electrically connected to the scanning line, and the source electrode 14a is electrically connected to the signal line.

  When a voltage is applied to the gate electrode 14b connected to the scan line, the source electrode 14a and the drain electrode 14c are brought into conduction, and the TFT 14 is turned on for a certain period. During this period, a signal necessary for image display is supplied from the signal line and written at a predetermined timing. The drain electrode 14 c is electrically connected to the pixel electrode 30 through the through holes 15 formed in the colored layers 24 a, 24 b and 24 c of the organic insulating film 24.

  The distance between the COA substrate 110 and the counter substrate 120 is held by the columnar spacer 31. The columnar spacer 31 is made of a resist resin different from the colored layers 24a, 24b, and 24c, and is arbitrarily set at a height of 2 to 6 μm.

  The counter substrate 120 includes a transparent substrate 21 made of glass or the like, and is disposed to face the COA substrate 110. The counter substrate 120 includes a transparent electrode 22 made of ITO and an alignment film.

  The COA substrate 110 and the counter substrate 120 are joined using a sealant 26 in a frame region that is the periphery of the display region 25, and the liquid crystal layer 70 is formed in a region surrounded by the COA substrate 110, the counter substrate 120, and the sealant 26. Is formed. In addition, the COA substrate 110 and the counter substrate 120 can be electrically connected by the transfer unit 50 at the time of bonding.

  The sealing material 26 seals the liquid crystal layer 70, and a black matrix layer (hereinafter referred to as BM layer) 27 is disposed inside the sealing material 26 as a light shielding layer. Further, a transfer unit 50 described later is disposed on the transfer pad 51 of the COA substrate 110 outside the seal material 26.

  Polarizers (not shown) are respectively disposed on the surfaces of the COA substrate 110 and the counter substrate 120 that are opposite to the liquid crystal layer 70 side.

  Hereinafter, the transfer unit 50 which is a characteristic part of the present embodiment will be described in detail. The same parts are denoted by the same reference numerals.

  A first colored layer 24a is formed on a connection pad (hereinafter referred to as transfer pad) 51 on the COA 110 substrate, and at the same time, a first pedestal (hereinafter referred to as transfer pedestal) 52 made of the same material is made smaller than the area of the transfer pad 51. A single layer is formed. This is because, if the transfer pedestal 52 becomes larger than the area of the transfer pad 51, a connection electrode (hereinafter referred to as a transfer electrode) 54 to be covered thereafter cannot be electrically connected to the transfer pad 51. At this time, the area ratio of the transfer pedestal 52 is preferably about 50% with respect to the transfer pad 51, but is not limited thereto. This is possible as long as conduction between a transfer pad 51 (to be described later) and a transfer electrode 54 made of a transparent electrode can be obtained. Moreover, in the said embodiment, although the 1st colored layer 24a was used for the transfer base 52, it is not limited to this. That is, although the second colored layer 24b or the third colored layer 24c can be used, it is desirable that the material is the same as the underlying colored layer of the columnar spacer 31 formed in the display region 25. Furthermore, since a general liquid crystal display device has 1 to 4 transfer portions 50, it is possible to use a mixed arrangement of the first colored layer 24a, the second colored layer 24b, and the third colored layer 24c.

  Thereafter, the columnar spacer 31 is formed of a resist resin different from the colored layers 24a, 24b, and 24c, and at the same time, a second base 53 (hereinafter referred to as a transfer spacer) 53 made of the resist resin is also formed on the transfer base 52 by 10 μm × 20 μm. A large number are formed at an arbitrary pitch in size. The size of the transfer spacer 53 can be other than 10 μm × 20 μm, but it is desirable that the size of the transfer spacer 53 is approximately the same as the size of the columnar spacer 31 in the display region 25. In order to keep the gap uniform or the like, it is desirable to form two or more transfer spacers 53, but this is not a limitation. That is, even one is possible. However, when the number of transfer spacers 53 is one, it is desirable to increase the size of the transfer spacers 53 in order to increase the contact area with the counter substrate 120. As a result, the total height of the transfer pedestal 52 and the transfer spacer 53 on the transfer pad 51 is the same as the total height of the colored layer 24 and the columnar spacer 31 in the display area 25. Thereafter, the pixel electrode 30 is formed, and at the same time, the transfer electrode 54 is formed of the same material as the pixel electrode 30 so as to cover all of the transfer pad 51, the transfer pedestal 52, and the transfer spacer 53. As a result, the transfer unit 50 can be electrically connected to the transfer pad 51 while having almost the same height as the gap control height of the display region 25. Thereafter, the alignment film and the sealing material 26 are arranged so as not to interfere with the transfer unit 50, and the COA substrate 110 and the counter substrate 120 are bonded to each other. As a result, conduction between the two substrates can be obtained via the transfer electrode 53.

  By such an apparatus and method, a low-cost liquid crystal display device can be obtained without the need for expensive materials such as silver paste and gold balls that have been used conventionally, or the process of applying and forming silver paste and gold balls on the transfer portion 50. Can be provided.

  In addition, this invention is not limited to the said embodiment itself, In the stage of implementation, it can change and implement a component within the range which does not deviate from the summary.

  In the above embodiment, the present invention has been described by taking the COA structure as an example. However, the present invention can also be applied to a liquid crystal display device having a color filter on a counter substrate. This will be described with reference to FIGS. 4 and 5, for example. FIG. 4 is an enlarged plan view of a color filter of a liquid crystal display device having a structure having a color filter on a counter substrate. FIG. 5 is an enlarged cross-sectional view taken along the line AA shown in FIG. 1 of the liquid crystal display device having a structure having a color filter. The transfer part 50 which is a characteristic part of the present invention is formed from the counter substrate 21 in the same procedure as in the case of the color filter-on-array structure described above. That is, the transfer pedestal 52 is simultaneously formed on the counter substrate 21 with the same material as one of the colored layers of the color filter 24, and then the transfer spacer 53 is simultaneously formed with the same material as the spacer 31.

  A transfer electrode 54 is formed so as to cover the transfer pedestal 52 and the transfer spacer 53 and can be electrically connected to the transfer pad 51 formed on the array substrate 130.

  Note that various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

DESCRIPTION OF SYMBOLS 10 ... Substrate 11 ... Scanning line 12 ... Signal line 13 ... Backlight 14 ... Switching element (thin film transistor)
14a ... Source electrode 14b ... Gate electrode 14c ... Drain electrode 15 ... Through hole 16 ... Auxiliary capacitance line 21 ... Transparent substrate 22 ... Transparent electrode (ITO electrode)
24 ... Colored layer 24a ... First colored layer 24b ... Second colored layer 24c ... Third colored layer 25 ... Display region 26 ... Sealing material 27 ... Black matrix (BM) layer 30 ... Pixel electrode 31 ... Columnar spacer 34 ... Alignment film 50 ... Transfer portion 51 ... Transfer pad 52 ... Transfer base 53 ... Transfer spacer 54 ... Transfer electrode 70 ... Liquid crystal layer 110 ... Color filter on array substrate 120 ... Opposite Substrate 130 ... Array substrate 140 ... Color filter substrate

Claims (4)

A first substrate comprising a plurality of wirings and a plurality of pixel electrodes arranged on the wirings and constituting a display region;
A second substrate having a counter electrode facing the pixel electrode;
Columnar spacers disposed between the first substrate and the second substrate in the display area,
In a display device comprising:
The first substrate is
A connection pad arranged outside the display area;
A pedestal arranged outside the display area;
A connection electrode disposed on the pedestal and in contact with the counter electrode, and electrically connected to the connection pad;
A display device comprising: Further, the first substrate includes an insulating film formed on the plurality of wirings,
The pedestal comprises a first pedestal formed on the connection pad and a second pedestal formed on the first pedestal,
The insulating film and the first pedestal are simultaneously formed of the same material,
The columnar spacer and the second pedestal are simultaneously formed of the same material,
The display device according to claim 1, wherein the pixel electrode and the connection electrode are formed of the same material at the same time.   The display device according to claim 2, wherein a height of the columnar spacer and a height of the second pedestal are substantially equal. A first substrate comprising a plurality of wirings and a plurality of pixel electrodes arranged on the wirings and constituting a display region;
A second substrate comprising a plurality of colored layers, and a counter electrode formed on the colored layer and facing the pixel electrode;
Columnar spacers disposed between the first substrate and the second substrate in the display area,
In a display device comprising:
The first substrate is
A connection pad disposed outside the display area;
The second substrate is
A first pedestal arranged outside the display area;
A second pedestal formed on the first pedestal;
A connection electrode disposed on the first and second pedestals to contact the connection pad and electrically connected to the counter electrode;
With
One of the colored layers and the first pedestal are formed of the same material at the same time,
The columnar spacer and the second pedestal are simultaneously formed of the same material,
The display device according to claim 1, wherein the counter electrode and the connection electrode are formed of the same material at the same time.

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