JP3418663B2 - Manufacturing method of liquid crystal display device and inspection method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a manufacturing method and a testing method thereof of the liquid crystal display equipment BACKGROUND OF THE INVENTION, and more particularly to a manufacturing method and a testing method thereof of the liquid crystal display equipment in which a color filter is formed on the TFT substrate side.

[0002]

2. Description of the Related Art In recent years, active matrix type liquid crystal display devices using thin film transistors as switching elements for driving liquid crystal have been actively developed.

As an example, a schematic plan view of a liquid crystal display device is shown in FIG. A gate driver 32, a source driver 33, and a TFT (Th
The inFilm Transistor) array unit 34 is arranged. The gate driver 32 includes a shift register 32a and a buffer 32b. The source driver 33 includes a shift register 33a and a buffer 33.
b and an analog switch 39 for sampling the video line 38. In the TFT array section 34, a plurality of parallel gate bus lines 116 extending from the gate driver 32 are arranged. From the source driver 33, a plurality of source bus lines 120 are arranged orthogonal to the gate bus lines 116. An additional capacitance common line 114 is arranged in parallel with the gate bus line 116. The TFT 35, the pixel 36, and the additional capacitance 37 are provided in a rectangular area surrounded by the two gate bus lines 116, the source bus line 120, and the additional capacitance common wiring 114. The gate electrode of the TFT 35 is connected to the gate bus line 116, and the source electrode is connected to the source bus line 120. TFT35
The liquid crystal is sealed between the pixel electrode connected to the drain electrode of the pixel and the counter electrode on the counter substrate to form the pixel. Further, the additional capacitance common wiring 114 is connected to an electrode having the same potential as the counter electrode.

Usually, on the inner surface of the counter substrate, a black matrix for preventing light leakage from the gaps between the pixel electrodes and a red color filter, a green color filter and a blue color filter corresponding to each pixel electrode are provided. The counter electrode is formed by a transparent conductive film on the upper surface thereof. As described above, when the black matrix and the color filter are formed on the counter substrate, there is a displacement in bonding when the TFT substrate and the counter substrate are bonded together, so that it is necessary to form the black matrix larger by that amount. The aperture ratio decreases. Further, when forming a color filter on the counter substrate, it is necessary to form a color filter having a high dimensional accuracy, so that, for example, a photolithography process is required, resulting in a high cost.

In order to solve this problem, Japanese Patent Laid-Open No. 5-5
It is considered to form a color filter on the TFT substrate side as shown in Japanese Patent Publication No. 874. This is because R (red) on the pixel electrode without using the photolithography process,
G, (green), B, and (blue) electrodeposition color filters are formed. In this conventional example, a scanning voltage is sequentially applied to a gate bus line to apply a voltage to a pixel electrode, and in synchronization with this, a voltage for forming an electrodeposition color filter on a data line corresponding to a predetermined pixel electrode. Is being applied. In this way, each time the gate bus lines are sequentially selected, the voltage is applied from the source bus line to only a predetermined pixel electrode among the pixel electrodes connected to the selected gate bus line, and the pixel to which the voltage is applied is applied. An electrodeposition color filter is formed on the electrodes.

[0006]

In the above-mentioned conventional example, it is necessary to sequentially apply signals to the gate bus line and the source bus line, and therefore it is necessary to operate the gate driver and the source driver. for that reason,
Many signals had to be input to these drivers.

Particularly, in the driver integrated liquid crystal display device in which the driver is formed on the same substrate as the TFT array,
Since the driver is formed of polycrystalline silicon, which has a lower mobility than single crystal, a plurality of series of shift registers are provided to reduce the operating frequency of each shift register as disclosed in Japanese Patent Publication No. 5-22917. However, a driver integrated liquid crystal display device has been realized even with polycrystalline silicon. For example, the mobility of polycrystalline silicon is 100 to 1
Signal line 800 with an element of about 50 (cm2 / v.sec)
In order to drive more than one liquid crystal display device, it is necessary to provide at least 4 series, preferably 8 series or more shift registers. FIG. 7 shows an example in which four series of shift registers 331 to 334 are provided in the source driver 33 to reduce the operating frequency of each shift register. Figure 7
In, the gate driver 32 and the source driver 33 are connected to the TFT array section 34. Each of the shift registers 331 to 331 provided in the source driver 33
Every four lines 334 are connected to the source bus line via the analog switch 39. Further, for example, three video lines 38 are connected to the analog switch 39. In the four series of shift registers 331 to 334, for example, at least the start pulse SP, the clock signal CK1, and / CK1 which is an inverted signal of the clock signal CK1 need to be input to the shift register 331. At least the start pulse SP, the clock signal CK2, and the clock signal CK
It is necessary to input / CK2 which is an inverted signal of 2, and the same applies to other shift registers. Therefore,
In the case of the shift register 8 series, it is necessary to input 2 × 8 = 16 (pieces) signals only with the clock signal for the shift register, and the device for signal input becomes complicated. Similarly, the gate driver 32 also has a start pulse SPG, a clock signal GCK, and the clock signal GC.
The inverted signal / GCK of K is input.

When a color filter is formed by a driver for driving a liquid crystal display device, after the expensive driver is connected to the substrate, the driver is damaged by static electricity in a subsequent process, for example, a rubbing process. There is a problem that the driver needs to be removed, and this driver cannot be used in an actual liquid crystal display device.

The present invention has been made in order to solve the problems of the prior art as described above, and a color filter can be simply provided by a small signal input without using a driver for driving a liquid crystal display device. formed a liquid crystal display equipment was
And a method for inspecting the same.

[0010]

Method of manufacturing a liquid crystal display device according to claim 1, wherein the SUMMARY OF THE INVENTION The present invention includes at least a gate bus line, a source bus line, a switching element array, and the pixel electrode, the switching element array A liquid crystal display including a first substrate including a source driver and a gate driver for operating and a second substrate on which a counter electrode is formed, and a liquid crystal sandwiched between the first and second substrates. In the method of manufacturing a device, the step of forming the switching element array, the step of forming the source driver, the gate driver, and the color filter forming driver in the same step on the first substrate, and the color filter forming driver. And a step of inputting a signal to form a color filter on the pixel electrode.

A method for inspecting a liquid crystal display device according to a second aspect of the present invention includes at least a gate bus line, a source bus line, a switching element array, a pixel electrode, and a source driver for operating the switching element array. And a gate driver, and a second substrate having a counter electrode formed thereon, wherein a liquid crystal is sandwiched between the first and second substrates. A driver for operating the switching element array is arranged at one end of the bus line, and a color filter forming driver is arranged at the other end of the bus line, and the switching element is formed by the color filter forming driver. It is characterized by inspecting a driver for operating the array for defects.

The operation of the above configuration will be described below.

According to the present invention, at least a gate bus line, a source bus line, a switching element array,
A first substrate having a pixel electrode and a source driver and a gate driver for operating the switching element array; and a second substrate having a counter electrode formed between the first substrate and the second substrate. In a method of manufacturing a liquid crystal display device in which liquid crystal is sandwiched between two, the step of forming the switching element array, the source driver, the gate driver, and the color filter forming driver are formed in the same step on a first substrate. The method is characterized by including a step and a step of inputting a signal to the color filter forming driver to form a color filter on the pixel electrode. Therefore, a driver IC for forming a color filter is provided.
It is not necessary to dispose on the substrate, and the color filter can be formed more easily. Further, since the step of connecting the color filter forming driver to the substrate can be omitted, it is possible to simplify the process and eliminate defects when connecting the color filter forming driver. In addition, an external driver I for forming a color filter
Since C is not required, the cost can be reduced accordingly.

According to the present invention, at least a gate bus line, a source bus line, a switching element array,
A first substrate having a pixel electrode and a source driver and a gate driver for operating the switching element array; and a second substrate having a counter electrode formed between the first substrate and the second substrate. In a method for inspecting a liquid crystal display device in which a liquid crystal is sandwiched between, a driver for operating the switching element array is arranged at one end of the bus line, and a color filter is formed at the other end of the bus line. Since a driver is arranged and the driver for operating the switching element array is inspected by the color filter forming driver, a special inspection device for inspecting the driver defect is required. Instead, a color filter forming driver can be used instead, making defect inspection easy and quick. Ukoto can. If there is a defect in the source driver or the gate driver, it is not necessary to send this to a subsequent process, so that the process loss can be eliminated. In addition, depending on the type of defect, the defect can be corrected and made good.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

(Embodiment 1) FIG. 1 shows a layout diagram of one pixel in Embodiment 1 of the present invention, and FIG. 2 shows a sectional view taken along the line AA in FIG. Hereinafter, the present invention will be described with reference to FIGS. 1 and 2.

As in the conventional example, a polycrystalline silicon thin film 11 serving as an active layer is formed on the insulating substrate 10 at a thickness of 40 nm to 80 nm.
Formed with a thickness of. Next, sputtering method or CV
The gate insulating film 13 is formed of SiO2 or Si by using the D method.
It was formed with Nx to a thickness of 80 nm. Next, 1 × 10 ¹⁵ (c
m ⁻² ) to reduce the resistance of this portion. The shaded area serves as the lower electrode of the additional capacitor. Next, the additional capacitance upper electrode 14 and the gate electrode 16 were formed using Al or polycrystalline silicon.

Next, in order to determine the conductivity type of this thin film transistor, the gate electrode 16 is arranged from above the gate electrode 16.
Using as a mask, phosphorus ions are implanted at 1 × 10 ¹⁵ (cm ⁻² ) to form a non-doped channel portion 12 in the active layer below the gate electrode 16, and a region other than the channel portion 12 is made as a high-concentration impurity region. . In the active layer of the TFT, a low-concentration impurity region or a non-doped region may be provided in the vicinity of the channel portion 12 so that the leak current is small when the TFT is off. Next, after forming the first interlayer insulating film 15 on the entire surface, contact holes 18 and contact holes 19 were provided. Next, the source bus line 20 or the source and drain electrodes 21 extended from the source bus line 20 were formed using a low-resistance metal such as Al. Next, the second interlayer insulating film 24 is formed. In this embodiment, a transparent photosensitive organic film is formed by spin coating. Further, in the first embodiment, since this liquid crystal panel is used as a transmissive liquid crystal display device, a transparent acrylic resin is used as the material of the second interlayer insulating film 24, not a colored organic material. .
Since the relative permittivity of the second interlayer insulating film 24 is as small as 4 or less and the film thickness is 2 μm or more, it is not affected by the electric field from below the insulating film. This makes it possible to suppress reverse tilt of the liquid crystal material when a voltage is applied to the liquid crystal layer.

Next, a contact hole 23 was formed on the drain electrode 21, and a pixel electrode 25 was formed of a transparent conductive film material such as ITO so as to cover the contact hole 23. The pixel electrode 25 is formed at least in the opening of the liquid crystal panel.

Next, this substrate is dipped in an R (red) electrodeposition solution, and an electrodeposition voltage is applied to the R pixel electrode to form an R electrodeposition color filter 30R on the pixel electrode. Then, similarly, the G (green) electrodeposition color filter 30G and the B (blue) electrodeposition color filter (not shown) are formed. A color filter was formed by the driver IC.

FIG. 3 shows an example in which the color filter forming driver 40 is arranged in order to form the color filters of the stripe arrangement in the first embodiment. In the final step, the gate driver 32 and the source driver 33 are connected to the TFT array section 34. In the first embodiment, the color filter forming driver 40 is connected to the TFT array section 34 on the side opposite to the source driver 33. ing. The TFT array unit 34 includes a gate driver 3
A plurality of parallel gate bus lines 116 extending from 2 are arranged, and from the source driver 33, a plurality of source bus lines 120 are arranged orthogonal to the gate bus lines 116. The color filter forming driver 40 is
One series of shift registers 41 and signal input terminals 43 (R for forming three series of R, G, B color filters
, 44 (for G), 45 (for B), and a sampling switch 42 for the color filter forming signal.
Every three signal input terminals are connected to the source bus line via the sampling switch 42.

When forming an R color filter, T
The ON voltage is sequentially applied to the gate electrodes of the pixel TFTs of the FT array section 34. When the pixel array of the TFT array section 34 is connected to the same bus line with a single color filter like a stripe array, the ON voltage may be simultaneously applied to the gate electrodes of the pixel TFTs. Also at this time,
Shift register 4 of color filter forming driver 40
1 is operated, 5V is applied to the R signal input terminal 43, and 0 is applied to the other two signal input terminals 44 and 45.
V is being applied. This operation is sequentially performed for G and B to form R, G and B electrodeposited color filters.

The color filter forming driver 40 does not have to have the performance required to drive the liquid crystal display device, and may operate at a low speed, for example. Therefore, the color filter can be formed using an inexpensive driver. It is desirable that the color filter forming driver 40 has a high breakdown voltage in consideration of being attached to and detached from the substrate and being used multiple times. Further, the color filter forming driver 40 may be arranged on the side opposite to the gate driver. The color filter forming driver 40 may be arranged independently on the source side or the gate side, or may be arranged on both sides. Further, a driver for driving each bus line may be arranged on the opposite side of the bus line on which the color filter forming driver 40 is arranged.

On the other hand, at least a counter electrode made of ITO is formed on the counter substrate. After that, the TFT substrate and the counter substrate are subjected to alignment treatment and bonded, and then liquid crystal is sealed between the substrates to form a liquid crystal panel.

As described above, since the color filter is formed by electrodeposition, the color filter is not displaced with respect to the pixel electrode. Even if the width of the bus line is narrowed as in a small and high-definition liquid crystal panel, this electrodeposition color filter can be formed in the same pattern as the pixel electrode 25, so that separation between adjacent color filters can be prevented. Since it can be performed on the line, the display quality is not deteriorated because the color filter is not arranged in the opening of the liquid crystal panel. Also, if there is a disconnection or malfunction of the thin film transistor on this TFT substrate,
A normal color filter is not formed on the pixel electrode. Therefore, after the color filter is formed, the presence or absence of a defect in the TFT substrate can be known by examining the color filter, so that the inspection of the color filter can also serve as the inspection step of the TFT substrate. Here, since it is not necessary to send the TFT substrate in which a defect is found to a subsequent process, it is possible to detect the presence or absence of a defect earlier than the conventional inspection after the liquid crystal panel is assembled, which is excellent in that there is no process loss. There is.

Embodiment 2 FIG. 4 shows a driver-integrated liquid crystal display device in which a color filter forming driver 40 is arranged to form a stripe-arranged color filter. In the driver integrated liquid crystal display device, the monolithic driver and the color filter forming driver 40 are completed at the time of forming the pixel electrode, and the color filter can be formed using the color filter forming driver. Above the TFT array section 34, four series of shift registers 3 as in the conventional example.
The source driver 33 is configured by 31 to 334, and at the same time, the color filter forming driver 40 is disposed below the TFT array section 34. The color filter forming driver 40 is a series of shift registers 41.
And signal input terminals 43 (for R), 44 (for G) and 45 (for B) for forming color filters of three series of R, G and B, and a sampling switch 42 for the signal for forming color filters. . Every three signal input terminals are connected to the source bus line 12 via the sampling switch 42.
It is connected to 0.

When forming an R color filter, TF
The ON voltage is sequentially applied to the gate electrodes of the pixel TFTs of the T array section 34. When the pixel array of the TFT array unit 34 is a stripe array and a single color filter is connected to the same bus line, the ON voltage may be simultaneously applied to the gate electrodes of the pixel TFTs. Also at this time,
While operating the shift register 41, 5V is applied to the R signal input terminal 43, and 0V is applied to the other two signal input terminals 44 and 45. This operation is sequentially performed for G and B to form R, G and B electrodeposited color filters.

As described above, since the operation speed of the shift register for driving the liquid crystal display device is not required to form the color filter, the operation of the shift register may be performed at a low speed, and therefore, it is used for forming the color filter. A plurality of series of shift registers is not necessary, and one series of shift registers may be provided. Therefore, since it is necessary to operate the shift register only for one series, the clock signal is also the clock signal C.
Only two lines, LK and an inverted signal / CLK of the clock signal CLK are required. By providing the color filter forming driver 40, the number of input signals can be significantly reduced.

It is also possible to inspect the source driver and the source bus line by the color filter forming driver 40. An example of the inspection method will be described with reference to FIGS. 4 and 5.

By operating the source driver 33, the signal S1 is applied to the first source bus line 120, the signal S2 is applied to the second source bus line 120, the signal S3 is applied to the third source bus line 120, and the fourth source bus line 120 is applied. Then, the signal S4 is sequentially output. At the same time, the shift register 41 of the color filter forming driver 40 is operated to output a signal to the gate electrode of the sampling switch 42 at the same timing as the signals S1 to S4.

If there is no defect in the source driver 33 and the source bus line 120, the signal input terminal 43 is used.
To the signal input terminal 44 with the waveform of the signal 44P.

On the other hand, for example, when the pulse of the signal S4 is not output from the source driver 33, the signal 43
Since the second pulse output to P is not output and is output to the signal input terminal 43 in the waveform as shown by 43P ', the defective portion can be specified. Furthermore, by examining the formation state of the color filter on the pixel electrode, it is possible to further identify whether the bus line is defective or the source driver is defective.

In the second embodiment, the case where the color filter forming driver 40 is formed on the source bus line has been described, but the present invention is not limited to this, and may be formed on the gate bus line. It may be formed on both the source bus line and the gate bus line.

In the first and second embodiments,
Although polycrystalline silicon is used as the semiconductor layer and the coplanar type is used as the structure of the TFT, the present invention is not limited to this, and other semiconductor materials may be used as the semiconductor layer. Other structure such as an inverted stagger type may be adopted as the structure. Further, although the electrodeposition method is used as the color filter forming method in the first and second embodiments, for example, the micelle electrolysis method can be used as another method.

[0035]

According to the present invention, at least a gate bus line, a source bus line, a switching element array,
A first substrate having a pixel electrode and a source driver and a gate driver for operating the switching element array; and a second substrate having a counter electrode formed between the first substrate and the second substrate. In a method of manufacturing a liquid crystal display device in which liquid crystal is sandwiched between two, the step of forming the switching element array, the source driver, the gate driver, and the color filter forming driver are formed in the same step on a first substrate. The method is characterized by including a step and a step of inputting a signal to the color filter forming driver to form a color filter on the pixel electrode. Therefore, a driver IC for forming a color filter is provided.
It is not necessary to dispose on the substrate, and the color filter can be formed more easily. Further, since the step of connecting the color filter forming driver to the substrate can be omitted, it is possible to simplify the process and eliminate defects when connecting the color filter forming driver. In addition, an external driver I for forming a color filter
Since C is not required, the cost can be reduced accordingly.

The present invention includes at least a gate bus line, a source bus line, a switching element array,
A first substrate having a pixel electrode and a source driver and a gate driver for operating the switching element array; and a second substrate having a counter electrode formed between the first substrate and the second substrate. In a method for inspecting a liquid crystal display device in which a liquid crystal is sandwiched between, a driver for operating the switching element array is arranged at one end of the bus line, and a color filter is formed at the other end of the bus line. Since a driver is arranged and the driver for operating the switching element array is inspected by the color filter forming driver, a special inspection device for inspecting the driver defect is required. Instead, a color filter forming driver can be used instead, making defect inspection easy and quick. Ukoto can. If there is a defect in the source driver or the gate driver, it is not necessary to send this to a subsequent process, so that the process loss can be eliminated. In addition, depending on the type of defect, the defect can be corrected and made good.

Further, since the color filter formed by the color filter forming driver is an electrodeposition color filter, the color filter can be accurately formed on the pixel electrode by an extremely simple process without using an expensive photolithography process. Forming can take place. Furthermore, pixel defects can be easily inspected.

Therefore, with simplification of the production process,
It is possible to improve the product throughput and further improve the production yield.

[Brief description of drawings]

FIG. 1 is a plan view of one pixel of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of one pixel of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 3 is a circuit diagram showing a configuration of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 4 is a circuit diagram showing a configuration of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 5 is a signal waveform diagram when a defect is inspected in the liquid crystal display device according to the second embodiment of the present invention.

FIG. 6 is a circuit diagram showing a configuration of a conventional liquid crystal display device.

FIG. 7 is a circuit diagram showing a configuration of a conventional liquid crystal display device.

[Explanation of symbols]

10 Insulating substrate 11 Polycrystalline silicon thin film 12 channel section 13 Gate insulating film 14 Additional capacitance upper electrode 15 First interlayer insulating film 16 gate electrode 18 contact holes 19 contact holes 20 Source bus line 21 drain electrode 23 Contact holes 24 Second interlayer insulating film 25 pixel electrodes 26 color filters 40 Color filter forming driver

Claims (2)

(57) [Claims] 1. A gate bus line, a source bus line, a switching element array, a pixel electrode,
A first substrate having a source driver and a gate driver for operating the switching element array and a second substrate having a counter electrode formed thereon are provided, and liquid crystal is sandwiched between the first and second substrates. Manufacture of liquid crystal display devices
In the method, the a step of forming the switching element array saws
Driver, gate driver, and color filter formation
Of forming the driver for the same on the first substrate in the same step
And input signals to the color filter forming driver.
And forming a color filter on the pixel electrode.
A method of manufacturing a liquid crystal display device , comprising: 2. A gate bus line and a source bus
A spline, a switching element array, a pixel electrode,
Source for operating the switching element array
A first substrate including a driver and a gate driver, and
And a second substrate on which a counter electrode is formed.
Inspection of liquid crystal display device in which liquid crystal is sandwiched between second substrates
In the method, the switching element array is provided at one end of the bus line.
Driver is placed to operate the
At the other end of the bus line, dry for color filter formation
The color filter forming driver and the switch
The driver for operating the array.
Method of inspecting a liquid crystal display device you characterized by査.