KR102047830B1 - Liquid Crystal Display And Lighting Inspection Method Thereof - Google Patents

Abstract

A liquid crystal display according to the present invention includes a display panel having a plurality of input pads connected to a plurality of data lines; A driver IC drive bumper for outputting a control signal for inspection; A first auto probe driving bumper and a second auto probe driving bumper for outputting a test data signal; In response to the inspection control signal, a plurality of first switches for switching electrical connections between odd output channels corresponding to odd input pads among the input pads, and even input pads among the input pads. A plurality of second switches for switching electrical connections between corresponding even output channels, a first inspection switch for connecting the first auto probe driving bumper to the odd output channels, and the second auto probe driving And a driver IC including a second test switch for connecting a bumper to the even output channels.

Description

Liquid Crystal Display And Lighting Inspection Method Thereof}

The present invention relates to a liquid crystal display device and a lighting inspection method thereof.

The liquid crystal display of the active matrix driving method displays a moving image using a thin film transistor (hereinafter referred to as TFT) as a switching element. The liquid crystal display device is applied to displays of portable information equipment, office equipment, computers, televisions, and the like.

The manufacturing process of the liquid crystal display device is divided into a substrate cleaning process, a substrate patterning process, an alignment film forming and rubbing process, a liquid crystal dropping and substrate bonding process, an inspection process, a repair process, a mounting process, and the like.

In the substrate cleaning process, foreign substances contaminated on the substrate surface of the liquid crystal display device are removed with the cleaning liquid. In the substrate patterning process, the substrate is divided into the patterning of the upper substrate (color filter array substrate) and the patterning of the lower substrate (TFT array substrate). A color filter, a common electrode, a black matrix, and the like are formed on the upper substrate. A signal line such as a data line and a gate line is formed on the lower substrate, a TFT is formed at an intersection of the data line and the gate line, and a pixel electrode connected to the TFT is formed in a pixel region between the data line and the gate line. In the alignment film forming and rubbing process, an alignment film is applied to each of the upper substrate and the lower substrate, and the alignment film is rubbed with a rubbing cloth or the like. In the liquid crystal dropping and substrate bonding process, the liquid crystal and the spacer are dropped, and then the upper substrate and the lower substrate are bonded to each other using a sealant. The inspection process includes an electrical lighting test performed after various signal wirings and pixel electrodes are formed on the lower substrate, and a defect inspection of each pixel. The repair process restores the substrate that is determined to be repairable by the inspection process. On the other hand, defective substrates that cannot be repaired in the inspection process are discarded. In the mounting process, a tape carrier package (hereinafter referred to as "TCP") on which a drive IC (Intergrated Circuit) is mounted is connected to a pad portion on a substrate. Such a drive IC may be directly mounted on a substrate by a chip on glass (COG) method in addition to the tape automated bonding method using the aforementioned TCP.

In the inspection process, an auto probe is used. The auto probe applies an electrical signal to the completed display panel to visually view a desired screen. The inspector detects spot defects, pre-defective defects, stains, and the like in the panel during the inspection through the auto probe to determine whether the panel is good or bad. The inspection method using an auto probe is similar to the Tr method in which a signal is applied to a panel through a single switching of a transistor to perform a test, and the probe pin is brought into contact with the panel's input pad 1: 1 by a real driver IC. There is a needle (needle) method for inspecting the panel, but in order to reduce the inspection time and inspection cost, the shorting bar method has been used a lot recently.

The shorting bar method short-circuits the signal wires of the display panel through the shorting bar and inspects it with a minimum pin contact. This method has several advantages, such as minimizing process consumable costs, no leaking due to pin contact misses, and no pad margin margins.

1 shows an example of a shorting bar method. FIG. 1 illustrates a first auto probe driving bump OBMP for supplying a test signal to the odd input pads electrically shorted by the first shorting bar SB1, and electrically shorted by the second shorting bar SB2. A second auto probe drive bump (EBMP) is shown for supplying a test signal to the even input pads. In the shorting bar method, after the inspection process is completed, additional work of opening the connection between the input pads and the shorting bar through laser trimming is necessary. The driver IC is mounted on the input pad part electrically separated from the shorting bar through the above-described mounting process.

Therefore, after the driver IC is mounted, the auto pad test can no longer be performed because the input pads and the shorting bar are disconnected. In other words, after laser trimming, the auto probe driving bumps cannot be used again and the auto probe can not be reexamined. As a result, if it is unclear whether the defects from the module process after the auto-probe inspection are only on the surface, or if the circuit portion and the mechanism portion are not clear, the liquid crystal module or board assembly should be separated to analyze the panel, circuit portion, and instrument portion, respectively. do. In the past, this unnecessary analysis wasted manpower, cost and time.

Accordingly, it is an object of the present invention to provide a liquid crystal display device and a lighting inspection method thereof which enable auto probe inspection even after laser trimming in a short bar method auto probe inspection.

In order to achieve the above object, a liquid crystal display according to an embodiment of the present invention includes a display panel having a plurality of input pads connected to a plurality of data lines; A driver IC drive bumper for outputting a control signal for inspection; A first auto probe driving bumper and a second auto probe driving bumper for outputting a test data signal; In response to the inspection control signal, a plurality of first switches for switching electrical connections between odd output channels corresponding to odd input pads among the input pads, and even input pads among the input pads. A plurality of second switches for switching electrical connections between corresponding even output channels, a first inspection switch for connecting the first auto probe driving bumper to the odd output channels, and the second auto probe driving And a driver IC including a second test switch for connecting a bumper to the even output channels.

The driver IC comprises: a data voltage generator for converting input digital video data into an image display data signal; A buffer unit having a plurality of buffers that buffer the image display data signal and supply the buffered data signal to the odd and even output channels; And a plurality of third switches configured to switch a current path between the buffer unit and the odd output channels and to switch a current path between the buffer unit and the even output channels in response to the inspection control signal. Equipped with.

The inspection control signal is generated in a first logic for the inspection process, and otherwise in a second logic; The first and second switches and the first and second inspection switches are turned on in response to the inspection control signal of the first logic, and the third switches are turned off; The first and second switches and the first and second inspection switches are turned off and the third switches are turned on in response to the inspection control signal of the second logic.

When the inspection control signal of the first logic is applied, the inspection data signal is input to the odd input pads through the odd output channels, and the inspection input signal is input to the even input pads through the even output channels. The data signal is input.

When the inspection control signal of the second logic is applied, the image display data signal is input to the input pads through the odd and even output channels.

According to an embodiment of the present invention, a display panel having a plurality of input pads connected to a plurality of data lines, and a method for checking lighting of a liquid crystal display including a driver IC having a plurality of output channels corresponding to the input pads, Outputting a control signal for inspection through a driver IC driving bumper; Outputting a test data signal through the first auto probe driving bumper and the second auto probe driving bumper; Switching the electrical connection between the odd output channels among the output channels corresponding to the odd input pads among the input pads by applying the test control signal to a plurality of first switches; Switching the electrical connection between the even output channels of the output channels corresponding to the even input pads among the input pads by applying the test control signal to a plurality of second switches; Applying the inspection control signal to a first inspection switch to connect the first auto probe driving bumper to the odd output channels; And applying the test control signal to a second test switch to connect the second auto probe driving bumper to the even output channels.

According to the present invention, even after laser trimming, the auto probe can be reexamined, and if it is not clear whether the panel is defective or the circuit and the mechanism are defective, the screen can be driven separately for the panel without having to separate the liquid crystal module or the board assembly. Through this, the present invention can save manpower, cost, time, etc., it is possible to analyze the defective object and location more efficiently.

1 is a view showing that a shorting bar is opened by laser trimming in a conventional shorting bar type auto probe inspection;
2 illustrates a liquid crystal display according to an exemplary embodiment of the present invention.
3 is a view showing a lighting test method before performing laser trimming.
4 is a view briefly showing a lighting test method after performing laser trimming.
5 is a diagram showing an internal configuration of a source driver IC capable of auto probe inspection through a switching action.
Fig. 6A shows the switching state of the switches when the inspection control signal is input to the first logic.
Fig. 6B shows the switching state of the switches when the inspection control signal is input to the second logic.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 2 to 6B.

2 shows a liquid crystal display according to an embodiment of the present invention.

2, a liquid crystal display according to an exemplary embodiment of the present invention includes a display panel 10, a timing controller 11, a data driver 12, and a gate driver 13.

The display panel 10 includes two glass substrates and a liquid crystal layer formed therebetween. In the display panel 10, a pixel array 10A arranged in a matrix form is formed by an intersecting structure of the signal lines 14 and 15.

Data lines 14, gate lines 15, TFTs, and a storage capacitor Cst are formed on a lower glass substrate of the display panel 10. The liquid crystal cell Clc is connected to the TFT and driven by an electric field between the pixel electrode 1 and the common electrode 2. The black matrix, the color filter, and the common electrode 2 are formed on the upper glass substrate of the display panel 10. The common electrode 2 is formed on the upper glass substrate in a vertical electric field driving method such as twisted nematic (TN) mode and vertical alignment (VA) mode, and has an in plane switching (IPS) mode and a fringe field switching (FFS) mode. In the same horizontal electric field driving method, the pixel electrode 1 is formed on the lower glass substrate. Polarizing plates are attached to each of the upper and lower glass substrates of the display panel 10 to form an alignment layer for setting a pre-tilt angle of the liquid crystal.

The timing controller 11 receives timing signals such as vertical / horizontal synchronization signals (Vsync, Hsync), data enable signals (Data Enable, DE), dot clock (DCLK), and the like, and the data driver 12 and the gate driver 13. Generates control signals (SDC, GDC) for controlling the operation timing. The timing controller 11 supplies digital video data RGB to the data driver 12.

The data driver 12 latches the digital video data RGB under the control of the timing controller 11. The data driver 12 generates the positive / negative analog data voltage according to the polarity control signal POL and supplies the digital video data RGB to the data lines 14 as a data signal for image display. The data driver 12 includes a plurality of source driver ICs (DICs) bonded to the display panel 10. The source driver IC (DIC) is provided with a plurality of output channels for outputting a data signal for image display. Output channels of the source driver IC (DIC) are electrically connected to the data lines 14 through input pads formed in the display panel 10. The source driver IC (DIC) includes a driver IC driving bumper (SBMP), a first auto probe driving bumper (OBMP), a second auto probe driving bumper (OBMP), and a plurality of switches as shown in FIGS. Ting-bar auto probe inspection enables auto probe inspection even after laser trimming.

The gate driver 13 sequentially supplies gate pulses to the gate lines 15 in response to gate timing control signals. The gate driver 13 may be mounted in a non-display area in which the image is not displayed on the display panel 10 according to a gate in panel (GIP) method. Shift registers of the gate driver 13 are formed together with the other TFTs of the display screen by the TFT process. The gate driver 13 may not be directly mounted on the display panel 10 according to a gate in panel (GIP) method, but may be implemented as a plurality of gate driver ICs bonded to the display panel 10. In this case, the configuration and method for the lighting test of the present invention can be applied to the gate driver IC as well as the source driver IC. Hereinafter, the lighting inspection method of the present application will be exemplarily described for the source driver IC.

3 shows a lighting test method before performing laser trimming, and FIG. 4 briefly shows a lighting test method after performing laser trimming.

FIG. 3 is a lighting test method of a shorting bar method before a source driver IC is attached. In FIG. 3, a first data supplying test data signal to the odd input pads electrically shorted by the first shorting bar SB1 is illustrated in FIG. 3. The auto probe drive bump OBMP and the second auto probe drive bump EBMP for supplying a test data signal to the even input pads electrically shorted by the second shorting bar SB2 are shown. Accordingly, the test data signal is commonly applied to the odd input pads through the first shorting bar SB1, and the test data signal is commonly applied to the even input pads through the second shorting bar SB2. do. The first and second shorting bars SB1 and SB2 may include input pads connected to red (R) liquid crystal cells, input pads connected to green (G) liquid crystal cells, and inputs connected to blue (B) liquid crystal cells. The pads may be different from each other. In this case, the inspection data patterns applied through the first and second shorting bars SB1 and SB2 may be implemented as R patterns, G patterns, B patterns, gray patterns, white patterns, and black patterns.

When the inspection process is completed in the shorting bar method of the present invention, the connection between the input pads and the shorting bar is opened as shown in FIG. 4 through laser trimming. The source driver IC is mounted on the input pad part electrically separated from the shorting bar through the above-described mounting process. In the conventional shorting bar method, since the input pads and the shorting bar are disconnected after the driver IC is mounted, the auto probe test can no longer be performed. However, the present invention provides laser trimming in the shorting bar method. Auto probe inspection is possible again afterwards.

To this end, according to the present invention, the control pin (CP), the first input pin (IP1), the second input pin (IP2) is installed in the source driver IC as shown in Figure 4, the test output from the driver IC drive bumper (SBMP) Control signal is applied to the control pin CP and the test data signals output from the first and second auto probe driving bumps OBMP and EBMP are input to the first input pin IP1 and the second input pin IP2. To apply.

For the inspection process, the inspection control signal switches a plurality of first switches to electrically short the odd output channels corresponding to the odd input pads of the input pads, and switches the plurality of second switches to switch among the input pads. Electrically shorts the even output channels corresponding to the even input pads. At this time, the inspection control signal switches the plurality of third switches to stop the normal image display data signal from being output from the source driver IC. In this state, the test data signal is applied to the odd input pads through the first input pin IP1 and to the even input pads through the second input pin IP1. The inspection data pattern after laser trimming may be implemented as a gray pattern, a white pattern, and a black pattern.

5 shows an internal configuration of a source driver IC (DIC) capable of auto probe inspection through a switching action. 6A shows a switching state of the switches when the inspection control signal is input to the first logic, and FIG. 6B shows a switching state of the switches when the inspection control signal is input to the second logic.

Referring to FIG. 5, a source driver IC (DIC) includes a data voltage generator 121, a buffer 122, and a switch array 123.

The data voltage generator 121 converts the input digital video data RGB into an image display data signal. The data voltage generator 121 may include a latch array, a gamma compensation voltage generator, a digital-analog converter, and the like.

The buffer unit 122 includes a plurality of buffers BUF to buffer the image display data signal generated by the data voltage generator 121 and to supply the same to the odd and even output channels CH1 to CHn.

The switch array 123 includes first switches SW1, second switches SW2, third switches SW3, a first test switch SWx, and a second test switch SWy. do.

The first switches SW1 correspond to the odd output channels CH1 corresponding to the odd input pads P1, P3,..., Pn-1 of the input pads P1 to Pn in response to the control signal for inspection. Switch between electrical connection between, CH3, ..., CHn-1). The first switches SW1 are connected between neighboring odd output channels CH1, CH3, ..., CHn-1.

The second switches SW2 correspond to the even output channels CH2 and CH4 corresponding to the even input pads P2, P4,..., And Pn among the input pads P1 to Pn in response to the test control signal. Switch the electrical connection between ..., CHn). The second switches SW2 are connected between neighboring even output channels CH2, CH4,..., CHn.

The third switches SW3 switch the current path between the buffer unit 122 and the odd output channels CH1, CH3,..., CHn-1 in response to the inspection control signal. Switch the current path between 122 and even output channels CH2, CH4, ..., CHn. The third switches SW3 are connected between the adjacent output channels CH1 to CHn.

The first inspection switch SWx connects the first auto probe driving bumper OBMP to the odd output channels CH1, CH3,..., CHn-1 in response to the inspection control signal. The second test switch SWy connects the second auto probe driving bumper EBMP to the even output channels CH2, CH4,..., CHn in response to the test control signal.

The inspection control signal may be generated in the first logic for the inspection process, or else may be generated in the second logic. Here, the first logic may be selected as a high logic and the second logic may be selected as a low logic, or vice versa.

In response to the inspection control signal of the first logic, the first and second switches SW1 and SW2 and the first and second inspection switches SWx and SWy are turned on, and the third switches SW3 are turned on. Can be turned off. To this end, an inspection control signal inverted through the inverter INV may be input to the control terminal of the third switches SW3. When the control signal for inspection of the first logic is applied, the odd output channels CH1, CH3, ..., CHn− are applied to the odd input pads P1, P3, ..., Pn-1 as shown in FIG. The test data signal is input through 1), and the test data signal is input through the even output channels CH2, CH4, ..., CHn to the even input pads P2, P4, ..., Pn. Is input. As can be seen from Figure 6a, the present invention is able to implement the auto probe inspection through the switching action.

Meanwhile, the first and second switches SW1 and SW2 and the first and second inspection switches SWx and SWy are turned off in response to the inspection control signal of the second logic and the third switches SW3. ) Can be turned on. When the control signal for inspection of the second logic is applied, the image display data signal is input to the input pads P1 to Pn through the output channels CH1 to CHn as shown in FIG. 6B, and as a result, the source driver IC Is driven normally.

As described above, according to the present invention, the auto probe can be reexamined even after laser trimming, and if it is not clear whether the panel is defective or the circuit part and the mechanism part are not clear, it is necessary to separately screen the panel without removing the liquid crystal module or the board assembly. It is possible to drive. Through this, the present invention can save manpower, cost, time, etc., it is possible to analyze the defective object and location more efficiently.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

10: display panel 11: timing controller
12: data driver 13: gate driver

Claims (10)

A display panel having a plurality of input pads connected to a plurality of data lines;
A driver IC drive bumper for outputting a control signal for inspection;
A first auto probe driving bumper and a second auto probe driving bumper for outputting a test data signal; And
A driver IC including a data voltage generator for converting input digital video data into a data signal for image display and a switch array for auto probe inspection;
The switch array of the driver IC
A plurality of first switches for switching electrical connection between odd output channels corresponding to odd input pads among the input pads in response to the inspection control signal;
A plurality of second switches for switching electrical connection between even output channels corresponding to even input pads among the input pads in response to the inspection control signal;
A first inspection switch for connecting the first auto probe driving bumper to the odd output channels in response to the inspection control signal; And
And a driver IC including a second inspection switch for connecting the second auto probe driving bumper to the even output channels in response to the inspection control signal. The method of claim 1,
The driver IC,
A data voltage generator for converting input digital video data into an image display data signal;
A buffer unit having a plurality of buffers that buffer the image display data signal and supply the buffered data signal to the odd and even output channels; And
In response to the inspection control signal, a plurality of third switches for switching the current path between the buffer unit and the odd output channels, and switching the current path between the buffer unit and the even output channels. A liquid crystal display device, characterized in that provided. The method of claim 2,
The inspection control signal is generated in a first logic for the inspection process, and otherwise in a second logic;
The first and second switches and the first and second inspection switches are turned on in response to the inspection control signal of the first logic, and the third switches are turned off;
The first and second switches, the first and second inspection switches are turned off, and the third switches are turned on in response to the inspection control signal of the second logic. . The method of claim 3, wherein
When the inspection control signal of the first logic is applied, the inspection data signal is input to the odd input pads through the odd output channels, and the inspection input signal is input to the even input pads through the even output channels. And a data signal is input. The method of claim 4, wherein
And when the control signal for inspection of the second logic is applied, the image display data signal is input to the input pads through the odd and even output channels. A liquid crystal display including a display panel having a plurality of input pads connected to a plurality of data lines, a driver IC having a data voltage generator for converting input digital video data into a data signal for image display, and a switch array for auto probe inspection. In the lighting test method of the device,
Outputting a control signal for inspection through a driver IC driving bumper;
Outputting a test data signal through the first auto probe driving bumper and the second auto probe driving bumper;
Switching an electrical connection between odd output channels among output channels corresponding to odd input pads of the input pads by applying the test control signal to a plurality of first switches belonging to the switch array;
Switching the electrical connection between the even output channels of the output channels corresponding to the even input pads of the input pads by applying the test control signal to a plurality of second switches belonging to the switch array;
Applying the inspection control signal to a first inspection switch belonging to the switch array to connect the first auto probe driving bumper to the odd output channels; And
And connecting the second auto probe driving bumper to the even output channels by applying the inspection control signal to a second inspection switch belonging to the switch array. . The method of claim 6,
Buffering an image display data signal corresponding to input digital video data through a buffer unit and supplying the image signal to the odd and even output channels; And
The inspection control signal is applied to a plurality of third switches to switch a current path between the buffer unit and the odd output channels and to switch a current path between the buffer unit and the even output channels. Lighting inspection method of the liquid crystal display device further comprising the step of. The method of claim 7, wherein
The inspection control signal is generated in a first logic for the inspection process, and otherwise in a second logic;
The first and second switches and the first and second inspection switches are turned on in response to the inspection control signal of the first logic, and the third switches are turned off;
The first and second switches, the first and second inspection switches are turned off, and the third switches are turned on in response to the inspection control signal of the second logic. How to check the lighting of. The method of claim 8,
When the inspection control signal of the first logic is applied, the inspection data signal is input to the odd input pads through the odd output channels, and the inspection input signal is input to the even input pads through the even output channels. A lighting test method of a liquid crystal display device, characterized in that a data signal is input. The method of claim 9,
And when the control signal for inspection of the second logic is applied, the image display data signal is input to the input pads through the odd and even output channels.

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