JPH0365927A - Liquid crystal display panel inspection equipment and its inspection method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a liquid crystal display panel testing device for testing the quality of an active matrix type liquid crystal display panel, and a testing method thereof.

Conventional technology In recent years, as the number of picture elements in liquid crystal display devices has increased, the number of scanning lines has increased, and in the conventional simple matrix type liquid crystal display panel, the display contrast and response speed have decreased, so switching is required for each picture element. Active matrix type liquid crystal display panels in which elements are arranged are being used. The liquid crystal display panel has tens of thousands of thin film transistors (
(hereinafter referred to as TPT). With current technology, it is difficult to form all the TPTs and signal lines without defects, so after forming the liquid crystal display panel,
It is necessary to perform an inspection and determine whether it is good or bad. In addition, LCD panels that can be repaired detect defective modes and defective locations, and process them using lasers or other tools. From the above,
There is a need for a liquid crystal display panel inspection apparatus and inspection method that can inspect a liquid crystal display panel at high speed and detect defect modes and defect locations.

Hereinafter, a conventional liquid crystal display panel inspection apparatus will be described with reference to the drawings.

FIG. 8 is a block diagram of a conventional liquid crystal display panel inspection device. In FIG. 8, 801 is a liquid crystal display panel;
06 is the loading stand for the liquid crystal display panel, 802a,
802b is a probe; 803a, 803b is a probe positioning stage that positions the probe; 804 is a controller that controls the positioning stages 802a, 802b; 805 is a resistance meter.

The operation of the liquid crystal display panel inspection apparatus configured as described above will be explained. First, the liquid crystal display panel 801 is placed on a loading table 806, and its angle, position, etc. are adjusted and positioned. Next, the controller 804 transfers positioning signals such as X and Y coordinates to the positioning stages 803a and 803b. Positioning stage 803 a
, 803b move based on the positioning signal, and position the probes 802a, 802b to the gate signal line or the extraction electrode (not shown) of the source signal line of the liquid crystal display panel 801.

When the positioning is completed, a positioning completion signal is sent to the controller 804.

When the controller 804 recognizes the positioning completion signal,
A resistance value measurement start signal is sent to the resistance meter 805.

A resistance meter 805 measures the resistance value between the probes 802a and 802b. The measured resistance value is sent to the controller 804, and it is determined whether or not a defect occurs in the liquid crystal display panel based on the resistance value.

By the same operation as above, the probe is pressed against all the gate signal lines and source signal lines, and the liquid crystal display panel is inspected.

A conventional method for inspecting a liquid crystal display panel will be described below. FIG. 9 is an explanatory diagram of an inspection method using a conventional liquid crystal display panel inspection apparatus. In Figure 9, G1 to G
4 is a gate signal line, 81 to S are source signal lines, T M
r + ~TM, , TS, ~TS44 is a thin film transistor (hereinafter referred to as TPT) P, ~P44 is a pixel electrode,
901 is a source signal line S.

902 is a disconnection defect that occurred in the gate signal line G2, and 903 is a short circuit that occurred at the intersection of the gate signal line G2 and the source signal line S4 (hereinafter referred to as a cross short). In FIG. 9, the number of signal lines of the liquid crystal display panel is kept very small in order to facilitate the operation. The above also applies to the following drawings. Here, as an example of an inspection method, a method for inspecting disconnection defects in signal lines of a liquid crystal display panel will be described first.

The method for detecting disconnection of the source signal line is the probe 802a.

802b is positioned and pressed onto both sides of the source signal line Sl. Next, the resistance meter 805 is operated to measure the resistance value of the source signal line. If a break in the signal line occurs, the ohmmeter will measure a higher resistance than normal, allowing it to be detected. Similarly, probe 802 a
, 802b is moved to the source signal line S2, and the resistance value is measured with the resistance meter 805 to check for disconnection. By performing the above operations on all source signal lines, the source signal lines can be inspected for disconnection. Similarly, the probes 802 a and 802 are used to inspect the gate signal line for disconnection.
This can be done by pressing b into both ends of the gate signal line and measuring the resistance value. Since disconnection points 901 and 902 occur in the liquid crystal display panel 801 shown in FIG. 9, when the resistance values of the source signal line St and the gate signal line G2 are measured, high resistance values are measured. Defects can be detected.

Next, a cross-short inspection method will be explained. First, connect the probe 802a to the gate signal line G, and connect the probe 802a to the gate signal line G.
02b is pressed against the source signal line Sl.

Next, the resistance value between the probes 802 a and 802 b is measured using a resistance meter 805 . Next, the probe 802a is fixed, and the probe 802b is sequentially connected to the source signal line S.
! to Sn (where n is an integer) and measure the resistance value in each pressure contact state. When the measurement of the resistance value between each source signal line with respect to the gate signal line G is completed, the probe 80
2a to the gate signal line Gt, and similarly connect the probe 80 to the gate signal line Gt.
2b is pressed against the source signal line Sl to Sn, and the resistance value in each pressure-connected state is measured. By performing the above operation on all gate signal lines and source signal lines, the resistance value at each intersection is measured. Since a cross short 903 has occurred in the liquid crystal display panel shown in FIG. 9, the probe 802a is connected to the gate signal line G! When the probe 802b is pressed against the source signal line S4, a resistance value lower than usual is measured by the resistance meter 805, so that the cross short 903 can be detected.

Problems to be Solved by the Invention However, the conventional liquid crystal display panel inspection apparatus and method have the following problems.

First of all, since it is necessary to press the probe into contact with all the gate signal lines and source signal lines, there is a problem that positioning takes a long time and inspection time is long. Second,
In order to test for cross-shorts, two or more stages are required, one for positioning the probe on the gate signal line and the other for positioning the probe on the source signal line, which raises the problem of high equipment costs for the test equipment. . Thirdly, there is a problem in that while a signal line breakage test can detect a signal line breakage, the location of the breakage cannot be detected. The detection of the disconnection point means that the source signal line S
This is the detection that the disconnection 901 of , is between the gate signal lines G2 and G. If a disconnection point can be detected, the disconnection point can be corrected by depositing a conductive material on the disconnection point and making a connection using photo-CVD technology or the like, and the manufacturing yield can be greatly improved.

Means for Solving the Problems In order to solve the above problems, the liquid crystal display panel inspection apparatus of the present invention includes a plurality of probes that connect to one end of the source signal line of the liquid crystal display panel, and a plurality of probes that are connected to one end of the source signal line of the liquid crystal display panel. A positioning stage for positioning to the electrode, a switch for selectively applying voltage to the probe or switching the input state of voltage from the probe, and a circuit for controlling a scan drive IC that applies a signal to the gate signal line of the liquid crystal display panel. It is equipped with the following. Further, in the liquid crystal display panel inspection method of the present invention, in a liquid crystal display panel in which a plurality of TPTs are formed in one pixel, the first source signal line and the first A current path is formed between a second source signal line adjacent to the source signal line, and a defect in the signal line is detected in detecting the signal applied to the first source signal line from the second source signal line. It is something to detect.

Operation The liquid crystal display panel inspection device of the present invention has a scanning drive I.
Since a voltage is applied to the gate signal line by C, there is no need for broaching the gate signal line. Further, in the inspection method, a signal is applied from one end direction of a first source signal line, and detection is performed from the same one end direction of a source signal line adjacent to the source signal line. Therefore, a break in the signal line can be detected by probing from one end of the signal line without pressing probes against both ends of the signal line.

Embodiment Hereinafter, one embodiment of the liquid crystal display panel inspection apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a liquid crystal display panel inspection apparatus according to an embodiment of the present invention. In FIG. 1, 101 is a liquid crystal display panel;
102 is a gate scanning IC for applying a signal to a gate signal line formed on the liquid crystal display panel 101. A gate scanning IC 1103 controls the gate scanning IC and applies T to any gate signal line.
gate scanning tC control means capable of controlling the application position of the voltage that turns on the PT (hereinafter referred to as on voltage) and the voltage that turns off the TPT (hereinafter referred to as off voltage);
104 is a probe card; 105 is a probe bin attached to the probe card 104 and serves as a means for electrically connecting the liquid crystal display panel to a source signal line; 106 is a positioning means for positioning the probe bin 105 to the source signal line. For example, a prober movable in the X, Y, and Z axes is generally applicable. 108 is a signal generating means such as a DC power supply that generates a predetermined voltage; 107 is a state in which the voltage from the signal generating means is applied to the probe pin 105, and a signal from the probe pin 105 is applied to the next stage input terminal selection means. input/output switching means 109 consisting of an analog switch etc. for switching the state; input terminal selection means 109 consisting of an analog switch etc. having the function of selecting one input terminal from a plurality of input terminals and connecting it to an output terminal; 110 is a determining means for determining whether or not there is a defect in the liquid crystal display panel based on the output signal from the input terminal selecting means, and 111 is a control means for controlling each of the above-mentioned means. Furthermore, in order to understand the liquid crystal display panel inspection apparatus of the present invention, each block will be explained using FIGS. 2 to 7. First, FIG. 2 is a block diagram of the gate scanning IC control means 103. In FIG. 2, the DATA terminal is a terminal for outputting a data signal for causing the gate scanning IC to output an on voltage and an off voltage, and a clock (CLO) terminal.
The enable (CK) terminal is a terminal for latching the data signal and outputting a clock for shifting the on-voltage or off-voltage position of the gate scanning IC.
The terminal (NABLE) is a terminal for controlling all outputs of the gate scanning IC to OFF voltage output, and the SP terminal is a control terminal for shifting the output position of the ON voltage or OFF voltage of the gate scanning IC to the right or left. be. When the gate scanning IC control means receives the gate signal line number for outputting an on-voltage from the control means 111, it outputs data from the four output terminals and causes the designated gate signal line of the gate scanning IC to output an on-voltage. . FIG. 3 is a perspective view of the probe card 104 and probe bin 105 shown in FIG. 1. In FIG. 3, 301 is the probe pin 10
5 and the input terminal of the input/output switching means 107, 302 is a plate for mounting the probe card 104, and 303 is a screw for finely adjusting the position in the Z-axis direction (hereinafter referred to as Z-axis fine adjustment). 304 is a screw for finely adjusting the position in the X-axis direction (hereinafter referred to as an X-axis fine adjustment screw); 305 is a support column;
, connected to positioning means movable in the Z-axis direction. FIG. 4 shows the state of connection between the probe pin 105 and the lead line 401 of the source signal line of the liquid crystal panel. Although the number of probe pins 105 is five in the drawings, it is not limited to this, and usually ten or more probe pins are formed. FIG. 5 is a block diagram of the input/output switching means 107. In FIG. 5, X1 to X are input/output terminals to which the wiring 301 is connected, and Y, to Y are input terminal selection means 109.
The output terminals S, ~Ss connected to the input terminals of are analog switches. The analog switches SW, ~SW change the applied voltage E based on the switching signal from the control means 111.
are individually connected to input/output terminals Xn (n is an integer from 1 to 5) or to input/output terminals Yn (n is an integer from 1 to 5).

FIG. 6 is a block diagram of the input terminal selection means 109.

In FIG. 6, 601 is a buffer, and 602 is an analog switch that selects one output terminal from a plurality of input terminals.

The input terminal selection means 109 selects a predetermined Yn (n is an integer from 1 to 5) according to an input signal line selection signal from the control means lll.
Connect the terminal and the 00 terminal.

The operation of the liquid crystal display panel inspection apparatus of the present invention will be described below with reference to FIG. First, the control means 111 selects positioning data to the positioning means 106. The positioning means 106 moves based on the data and presses the probe pin 105 against the extraction electrode 401 of the liquid crystal display panel 401 to establish an electrical connection. Next, control means 1
11 sends a switching signal to the input/output switching means 107 and an input terminal selection signal to the input terminal selection means, applies a voltage to the first probe pin 105 located at the end, and applies a voltage to the first probe pin 105 located at the end. Adjacent second probe pin 10
5 manually, and the input terminal selection means 109 is set to ○. Control the state so that it can be output to the terminal. Next, the gate scanning IC control means 103 is controlled to apply an on-voltage to a predetermined gate signal line. At this time, the signal applied to the second probe bin is taken out from the 0° terminal, the determination means 110 determines whether there is a defect in the liquid crystal display panel, and the determination means 110 sends the result to the control means 111.

From now on, the same process as described above will be performed by applying a voltage to the second probe pin and controlling the switch so that a signal can be input from the third probe pin adjacent to the second probe pin. When the above-described processing is completed for all probe pins 105, the positioning means 106 is moved to press the probe pins 105 into contact with the extraction electrodes 401 of other source signal lines.

Hereinafter, an embodiment of the liquid crystal display panel inspection method of the present invention will be described with reference to the drawings. FIG. 7 is an explanatory diagram for explaining one embodiment of the liquid crystal display panel inspection method of the present invention. In FIG. 7, RI-R,l is a pickup resistor, 701.702 is a disconnection point of the signal line, and 70
3 is a cross short.

First, a method for inspecting a source signal line for disconnection will be explained. First, the probe pin 105 is pressed against the source signal line. Next, control switches SW1 and SWt, etc.
Apply voltage E to source signal line S, and source signal line S2.
Controls the zero-order gate scanning IC control means 103 that connects the output terminal Oo and the output terminal Oo, and applies an on-voltage to the gate signal lines G and 02, and an off-voltage to the other gate signal lines. Then, TM of the TFT and T S + + are turned on, and SW.

→S1→TM, →P, →TS, →S2→5W2-→O0
A current path is created. However, since there is a disconnection point 701, the above-mentioned current path cannot be established, and therefore only the ground potential is detected at 02. The determining means 110 compares the reference voltage manually applied to one terminal of the comparator with the potential,
The fact that a disconnection has occurred is sent to the control means 111.

Therefore, the control means 111 is controlled by the gate scanning IC control means 103.
is controlled, the on-voltage application position is shifted, and the on-voltage is applied to the gate signal lines G2 and G. Then, T of TFT
M, and TS, are turned on. When the above operations are performed in sequence and the on voltage is applied to the gate signal lines G3 and 64, sw,'→S2→TM,,→P21→TS,→
By creating a current path of S2→SW2→0°,
An output voltage is output to Oo.

From the above, it is possible to detect that there is a disconnection point between the gate signal lines G2 and G1. However, with only the above processing, the source signal line S.

It is not possible to distinguish between the above case where a disconnection occurs between the gate signal lines G and G4. This determination is made using the source signal line S.
When a voltage is applied to SW2 and the source signal line S3 is brought into the signal power state, and an on voltage is applied to the gate signal lines G1 and 02, SW2→52-T VBt-P, t-T
Sl! This can be determined from the fact that a current path of -+S x →S W3- Oo is not formed. While moving the probe, apply voltage to source signal line S2, input signal from S, apply voltage to source signal line S, input signal from S4, apply voltage to source signal line S4, S
By performing this on the signal input and all source signal lines from s, it is possible to detect disconnections and disconnection locations in the source signal lines. After turning on the TPT of the pixel farthest from the location and detecting the presence or absence of a disconnection in the source signal line, the disconnection location is detected.

Next, a method for detecting disconnection of the gate signal line will be described.

First, the probe pin 105 is pressed against the source signal line furthest from the gate scanning IC 102 . In the case of FIG. 7, source signal lines S, -S.

Press the probe pin onto the Note that an actual liquid crystal display panel has more than 200 source signal lines and 200 or more gate signal lines each. Next, switch S front 2 and SW3
etc., and the source signal line S.

Apply voltage E to source signal line S4 and output terminal ○. Connect with. Next, the gate scanning IC control means 103 is controlled to apply an on voltage to the gate signal lines G and 02 and an off voltage to the other gate signal lines.

Then, T M l 4 and TS are in the on state,
SWs →S s→T S ra-P ra-TM
A current path of +a=S a -S Wz→O0 is created, and the voltage is output as 00.6 Next, an on-voltage is applied to the gate signal lines G2 and G. However, the gate signal line G,
Since a disconnection point 702 has occurred in , the on-voltage is no longer transmitted. Therefore, T M z a is not turned on.

Therefore, SW3→S, →TS, →Pt4→TM8
4→S4→SW2→○. No current path occurs, and O0
A ground potential is output to the terminal. From the above, it is possible to detect that a disconnection has occurred in the gate signal line G3. The above operation is performed for all gate signal lines to detect disconnection of the gate signal line. Next, a voltage E is applied to the source signal line S, and the source signal line S is connected to the O0 terminal, and from now on, an on-voltage is applied to the gate signal line in which the disconnection has been detected to perform inspection. In other words, gate signal line G2
On-voltage is applied only to and 03. The above operations are performed sequentially while moving the probe pin. In the case of FIG. 7, when the voltage E is applied to the source signal line S3 and the source signal line St is connected to the 00 terminal, SW, →
S, →Ts! 2→P zz”T Mzt-S z →S
A current path Wz → Oo is generated, and a voltage is output to the 0° terminal. From the above, it can be detected that the curved portion of the gate signal line G3 occurs between the source signal lines S2 and 33.

Note that cross-short detection can also be easily performed at high speed. First, the gate scanning IC control means 103 is controlled to apply an off voltage to all gate signal lines. Next, probes are sequentially pressed against the source signal lines for inspection. At this time, SW1 to SW are controlled so that a signal is input from the source signal line. If there is no cross short in the source signal line to which the probe is pressed, the O0 terminal will be at ground potential.

When the probe is pressed into contact with the source signal line S4, a cross short 703 occurs, so an off voltage is output to the 0° terminal. Next, an on-voltage is applied to the gate signal line G+, and the on-voltage application position is sequentially moved in the direction of the gate signal line G4. Now, when an on-voltage is applied to the gate signal line Gz, the on-voltage is output to the 0° terminal. From the above, it can be detected that a cross short 703 has occurred at the intersection of the gate signal line G2 and the source signal line S4.

In the embodiments of the present invention, probe pins are used for connection to the source signal line, but the invention is not limited to this, and it goes without saying that, for example, a conductive rubber connector or the like may be used.

Further, although the probe pins are sequentially moved, it goes without saying that the positioning means 106 is not necessary if connections can be made to all the source signal lines of the liquid crystal display panel at once.

Furthermore, although the object to be inspected in the present invention is a liquid crystal display panel,
The present invention is not limited to this, and can be applied to, for example, inspection of a state before injection of liquid crystal, that is, a TFT array.

Effects of the Invention In the liquid crystal display panel inspection device and the inspection method of the present invention, a gate signal line is loaded with or has a scanning IC, and the gate signal line is turned on and off by controlling the IC. Apply voltage.

Therefore, it is only necessary to press the probe pin to the source signal line. Therefore, very high-speed inspection can be performed.

In addition, inspection for disconnections and cross-shorts in the gate signal line and the source signal line can be performed simply by pressing a probe pin into one end of the source signal line. Therefore, an inspection apparatus that conventionally required a plurality of positioning stages can be configured with one positioning stage, and the equipment cost of the inspection apparatus can be reduced.

In addition, although conventional inspections could not detect wire breaks,
According to the present invention, the disconnection can be easily detected and the broken line can be corrected, so that the manufacturing yield of liquid crystal display panels can be significantly improved.

[Brief explanation of drawings]

1, 2, 5, and 6 are block diagrams of an embodiment of the liquid crystal display panel inspection apparatus of the present invention, and FIG.
FIG. 4 is a partial perspective view of an embodiment of the liquid crystal display panel inspection apparatus of the present invention, FIG. 7 is an explanatory diagram showing an embodiment of the liquid crystal display panel inspection method of the present invention, and FIG. 8 is a conventional FIG. 9 is a block diagram of a liquid crystal display panel inspection apparatus, and FIG. 9 is an explanatory diagram of a conventional liquid crystal display panel inspection method. 101, 801...Liquid crystal display panel, 102.
...Gate scanning IC, 103... Gate scanning IC control means, 104... Probe card, 105.802 a, 802 b...
Probe pin, 106...Positioning means, 10
7... Input/output switching means, 108... Signal generation means, 109... Input terminal selection means, 1
10... Judgment means, 111... Control means, 301... Wiring, 302... Mounting on plate, 303... Z-axis fine adjustment. Screw, 304...
...XIdI? II adjustment screw, 305...Support column, 401...Leader line, SW, ~SWS
...changeover switch, XI-X, ...
...input/output terminal, Y1~Y, ...input terminal,
601...Buffer, 602...Analog switch, 701.702°901, 902...
...Disconnection point, 703.903...Cross short, R, -R,...Resistance, 803 a,
803 b...Positioning stage, 804...
...Controller, 805...Resistance meter, 8
06...Loading platform.

Claims (7)

[Claims] (1) A plurality of connecting means formed on the liquid crystal display panel for electrically connecting one end of the data signal line, and an electrical connection between the connecting means and the data signal line formed on the liquid crystal display panel. A positioning means for positioning to establish a connection, a signal generation means for generating a signal, a signal input means for inputting a signal, and a data signal line to which the connection means connects the signal generated by the signal generation means. and a circuit for applying a signal to the scanning signal line of the liquid crystal display panel. 1. An inspection apparatus for a liquid crystal display panel, comprising: a scanning circuit control means for controlling a scanning circuit. (2) The liquid crystal display panel inspection apparatus according to claim (1), wherein the liquid crystal display panel is an active matrix type liquid crystal display panel in which a plurality of switching elements are formed in one pixel. (3) Claim (3) characterized in that the positioning means is movable in at least one of the X direction, the Y direction, and the Z direction.
1) The liquid crystal display panel inspection device described above. (4) In a liquid crystal display panel in which a plurality of thin film transistors are formed in one pixel, by activating the plurality of thin film transistors, a first data signal line and a second data adjacent to the first data signal line are connected. By forming a current path between the signal lines and detecting the signal applied to the first data signal line from the second data signal line,
A method for inspecting a liquid crystal display panel, comprising detecting at least a disconnection defect in a scanning signal line and a data signal line formed on the liquid crystal panel. (5) Inspection of a liquid crystal display panel according to claim (4), characterized in that a plurality of thin film transistors of one pixel are put into an operating state by controlling a circuit that applies a signal to a scanning signal line of the liquid crystal display panel. Method. (6) Liquid crystal display panel inspection according to claim (4), characterized in that a signal is applied from one end direction of the first data signal line, and a signal is detected from the same one end direction of the second data signal line. Method. (7) The method for inspecting a liquid crystal display panel according to claim (4), wherein the inspection is carried out by sequentially moving the positions of the thin film transistors to be brought into operation.