JPH0697249B2 - Inspection correction method and inspection correction apparatus for matrix type image display device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection correction method and an inspection correction device, and is particularly useful for inspection and correction of a matrix type image display device or a main part device for the same.

Conventional technology Due to recent advances in fine processing technology and material technology,
Although it is as small as 6 inches, it is possible to provide a television image by a liquid crystal panel, and a so-called active type with a built-in switching element for each pixel also guarantees a high contrast ratio, and an image quality almost equal to that of a CRT can be obtained. ing.

Such a liquid crystal panel is also called a matrix type image display device, because the provided screen is vertical (scanning).
This is because a large number of independent pixels are formed at the intersections of 120 to 480 scanning lines in the direction and 240 to 720 signal lines in the horizontal direction.

As is well known, since the pixel display device is an object that is identified by a highly sensitive sensor of human vision, there are very severe restrictions on various defects, not to mention line defects but point defects as well as CRTs. Compared with, it is a very difficult device, in other words, it has a low yield and is difficult to make.

The point defect inspection is equivalent to a full-bit inspection in the case of a memory, and generally depends on the device structure, but generally the inspection time is long and difficult. The fact is that the point defects are also inspected at the same time when the process is carried out, and an inspection machine that can effectively detect the point defects during the process has not been put into practical use, so will be omitted.

The line defect is literally a line defect, and the reason for its occurrence is clearly due to the following reasons. (1) The scanning line or the signal line is broken midway, (2) the electric signal has not reached the scanning line or the signal line, (3) the scanning line and the signal line are short-circuited, (4) The main cause is that a plurality of scanning lines or signal lines themselves are short-circuited.

At present, no rationalized inspection device is available on the market, and a deep needle (probe) is brought into contact with both ends of a scanning line or a signal line to determine whether or not there is a disconnection, and then a short circuit between adjacent lines is performed. A test such as judgment is performed on all the scanning lines and signal lines, and then a specific scanning line or signal line or a block in which several tens of scanning lines or signal lines are bundled and one signal line or scanning line are short-circuited. It is like a general scanning method to inspect.

It is needless to say that no line defect is allowed because it is an image display device, but it is obvious that the above-described procedure has poor productivity in the inspection process. Even if it is simply GO-NoGo quality judgment, in the high value-added active matrix image display device, it is necessary to repair the short-circuited portion by laser cutting to make it a good product, and for the disconnection, the present inventor However, as previously filed in Japanese Patent Application No. 61-145237, it is possible to improve the apparent yield by incorporating a relief line capable of supplying an electric signal from both ends only to the broken portion. In any case, precise address (location) specification is required for line defects,
Not only is it impossible to deal with the problem by measuring one line at a time, but it is completely useless if there is no line defect. Therefore, an inspection method for efficiently finding line defects is desired.

Means for Solving the Problems The present invention has been made in view of the above-mentioned current situation, and in applying a test signal to all terminals of a matrix-type image display device, a scanning line and a signal line are each divided into a plurality of blocks. Scanning by applying the same inspection signal to the plurality of scanning lines of one block on the scanning line side at the same time, and simultaneously applying the same inspection signal to the plurality of signal lines of one block on the signal line side The leak current in the line and the signal line is measured, the measurement is repeated between each block of the scanning line and the signal line, and when a short circuit between the scanning line and the signal line is detected, the measurement is performed in the corresponding block. An inspection signal is sequentially applied to precisely identify a short circuit portion between the scanning line and the signal line, and the stage carrying the matrix type image display device or the beam irradiation port of the laser is moved. Let me
It is a method for inspecting and correcting a matrix type image display device, which comprises irradiating a laser beam to two points of the scanning line or the signal line including the short-circuited portion, sandwiching the short-circuited portion, and fusing the scanning line or the signal line.

A means for applying inspection signals to all the scanning lines and signal lines of the matrix type image display device having scanning lines and signal lines divided into a plurality of blocks, and the same inspection signal for a plurality of scanning lines for each block. And an inspection signal source having means for simultaneously applying the same inspection signal to a plurality of signal lines for each block, and an inspection signal from the scanning signal source to a plurality of scanning lines for each block at the same time. In addition, the inspection signal is applied to a plurality of signal lines at the same time to measure the leak current in the scanning line and the signal line to detect the presence or absence of a short circuit, and if there is a short circuit, the inspection signal is scanned in the corresponding block. Means for precisely identifying the short-circuited portion by sequentially applying to the signal line and the signal line, and the scanning line of the short-circuited portion in the matrix type image display device identified by this means. Is a matrix type image including a laser for melting the signal line, and means for moving the beam irradiation port of the laser to irradiate the beam of the laser to an arbitrary position in the matrix type image display device. It is an inspection and correction device for a display device.

Function The number of inspections is reduced by supplying the same inspection signal to a plurality of terminals, and when a short circuit is found, precise identification is performed only within the block, so the inspection time is greatly shortened.

Embodiment Hereinafter, an inspection correction method and an inspection correction apparatus according to an embodiment of the present invention will be described with reference to the drawings.

In Fig. 1, for example, 480 scanning lines are divided into 8 blocks of 60 lines each (G1 to G8), and 720 signal lines are divided into 6 blocks of 120 lines each (S1 to S6). The matrix-type image display device 1 has terminals arranged in the peripheral portion. Reference numeral 2 denotes the image portion, and other electrode wires (common ground, transparent electrode on the color filter side, etc.) are omitted for simplicity. Scan line terminal group 3 (G1 to G8) and signal line terminal group 4
An inspection film 6 having (S1 to S6), for example, a polyimide resin base and a gold-plated copper foil terminal group 5
Is electrically contacted with the electrode terminal by means such as pressure contact.

FIG. 2 partially shows a connection diagram between the terminal group 5 and the measurement system, and shows the measurement of the leak current between the scanning line and the signal line, that is, the measurement for performing the short-circuit test. Reference numeral 9 is a shift register for driving the voltage generator 10, the output signal of which is the voltage generator.
10 is supplied to one input terminal 11 of the voltage generator 10, and the other input terminal 12 of the voltage generator 10 is supplied with the voltage V ₁ from the voltage source 14 by opening and closing the switch 13. The output 7 of the voltage generator 10 is supplied to the scanning line terminal group 3 through the deep needle terminal group 5. 15
Is a shift register for driving the analog switch 16, and its output is supplied to the switch terminal 17 of the analog switch 16. One terminal 18 of the analog switch 16 is connected to the terminal group 4 of the signal line through the deep needle terminal group 5 ', and the other terminal 19 is connected to the current meter 20. Another analog switch 21 is connected in parallel with the terminals 18 and 19 of the analog switch 16, and the switch is connected to the switch terminal 22.
By opening / closing 23, the voltage V ₂ is simultaneously supplied from the voltage source 24.

The measuring system shown in FIG. 2 refers to inspection according to the sequence shown in FIG. First, the first block G1 on the scanning line side and the first block S1 on the signal line side (60 ×
Collectively check for short circuits with (including 120 intersections). For that purpose, the switch 13 is closed and all the voltage generators 10 are turned on to supply a predetermined inspection voltage to all the scan electrodes in the first block G1 at the same time.
Analog switch by closing and applying inspection signal
All 21 should be made conductive. And with G1 block
The leak current I at the intersection occupied by the S1 block is measured by the current meter 20 and stored as necessary. When the measurement of the G1 block and the S1 block is completed, the block inspection is next performed between G1 and S2 in the same manner as described above, in the above-described example, 8 × 6 = 48 times. The inspection signal can be supplied to all terminals of the matrix type image display device. In each block inspection, the leak current is the specified value Io
If it is smaller than the above, it is a good product and the inspection is completed. When the value exceeds the specified value Io, a signal from the current meter 20 is received to identify the block where the leak exists.

Next, the precise identification of the leak location found by the block inspection will be described with reference to the sequence signal flow of FIG.

With the switches 13 and 23 for simultaneously operating the voltage generator 10 and the analog switch 21 kept open, the clock signal φ ₁ is applied to the shift register 9, and the voltage generator 10 keeps the predetermined time T ₁ , For example, while the inspection voltage is generated for 20 seconds, the voltages are sequentially applied to the 1st to 60th in the block. Then, while the inspection voltage is being supplied to the scanning line, the clock signal φ ₂ is applied to the shift register 15, and the analog switch 16 is kept in the conducting state for a predetermined inspection time T ₂ , for example, 0.1 seconds, while the block switch Scan sequentially from No. 1 to No. 80. In this way, the leak at the intersection formed by 60 × 80 = 4800 scanning lines and signal lines is checked. If the current meter 20 detects a current larger than the specified value, it is assumed that a short circuit exists, and the short circuit location is recognized by the count number after the precise identification of the clock signals φ ₁ and φ ₂ is started. It is.

The time setting depends on the measurement system, the noise environment, the stabilization time of the measuring instrument, etc., and it is not so difficult to reduce the time to about 1/10 of the above example.

Further, in the above example, only the leak measurement between the scanning line and the signal line is described, so the scanning line or the signal line does not need to have terminals at both ends, but if terminals are provided at both ends. For example, it is clear that adjacent short circuits between scanning lines or signal lines and disconnection of scanning lines or signal lines can be easily and precisely identified by the same idea as in the present invention.

Of course, the switches 13 and 14 in FIG. 2 can be electrically controlled, and it is easy to fully automate the above-described measurement / inspection by a sequence program prepared in advance. Further, although not shown, the output terminals of the voltage generator 10 and the analog switches 16 and 21 are prevented so that the scanning line or the signal line to be inspected is not charged up due to static electricity or noise and the element is destroyed depending on its polarity. It is important to connect an analog switch of appropriate impedance to the ground line. Of course, this analog switch is opened during inspection so that it does not interfere with measurement.

After the scanning line and the signal line is short-circuited is precisely identified, the scanning line or the signal line is melted by the laser, but in the present invention, in order to reliably release the short circuit,
It is claimed that the scanning line or the signal line including the short-circuited portion should be blown at two places sandwiching the short-circuited portion. This is the TFT
In an active image display device in which (thin film transistor) is incorporated in each pixel as a switch element, a part of the scanning line constitutes a gate electrode, and the short circuit between the gate electrode and the signal line is the short circuit between the scanning line and the signal line. It is based on the fact that it occurs with a much higher probability than.

In order to carry out the laser fusing, a positional accuracy on the order of μm is required, but in the present invention, the positional accuracy is secured by the positioning for bringing the deep needle means such as the inspection film into contact with the object to be inspected, and the scanning is performed. Since the intersecting position of the line and the signal line is clearly defined by the mask design, fully automatic laser fusing is possible if the location of the laser fusing is determined in advance. However, there is a possibility that the certainty of fusion cutting may decrease due to changes in laser power and spot size, or changes in the thickness of conductive paths such as scanning lines and signal lines that are about to be melted. It should be said that this is an incidental work that is sufficiently convincing.

In any case, a short circuit between the scanning line and the signal line can occur at any place in the image display unit, so the laser beam irradiation port or the matrix type image display device to be inspected or its main part device is carried. Needless to say, a mechanism such as a driving by a stepping motor is required to move the inspection stage to an arbitrary position.

Although it takes a little time to inspect, the method for inspecting all terminals by step feed is shown in FIG. 2 in which an inspection film is prepared on the scanning line and a minimum unit of 1 to 2 sheets on the scanning line side in FIG. Although it is rational in that many voltage generators and analog switches are not required, it is obvious from the gist of the present invention that such rationalization is regarded as an embodiment of the present invention.

It goes without saying that the matrix type image display device is not limited to the liquid crystal panel, and the switch element in the case of the active type is not limited to the TFT.

As described above, according to the present invention, a short circuit between a plurality of conductive paths that should originally be insulated, such as a scanning line and a signal line, is collectively inspected in a proper unit. Only when a leak is found, the leaks are measured one by one, the existence thereof is precisely identified, and an inspection / correction is performed such that the laser melts and the wire breaks. Therefore, it is clear that the higher the density and the large area, that is, the larger the number of inspections, the more efficient it is, and the smaller the number of short circuits, that is, the more the device manufacturing reaches the industrialized level, the higher the operation efficiency becomes. .

[Brief description of drawings]

FIG. 1 is a plan view showing an electrode terminal group and a test film used as a detector for the terminal group, which are arranged in a divided manner around a matrix-type image display device or a device for the same purpose.
FIG. 3 is a plan view also showing a circuit diagram of the measurement system according to the present invention, FIG. 3 is a sequence flow of the measurement system according to the present invention, and FIG. 4 is a time chart of a clock signal at the time of precise identification. 1 ... Matrix type image display device, 2 ... Image part, 3 ...
… Scanning line terminal group, 4 …… Signal line terminal group, 6 …… Inspection film, 9,15 …… Shift register, 10 …… Voltage generator, 13,23 …… Switch, 14,24 …… Voltage Source, 16,21 ……
Analog switch, 20 ... Electricity meter.

Claims (3)

[Claims] 1. When applying an inspection signal to all terminals of a matrix type image display device, a scanning line and a signal line are each divided into a plurality of blocks, and the scanning lines and the scanning lines of one block are simultaneously divided. The same inspection signal is applied, and simultaneously the same inspection signal is applied to the plurality of signal lines of one block on the signal line side to measure the leak current in the scanning line and the signal line, and the measurement is performed in the scanning. Repeated between each block of the line and the signal line, when a short circuit between the scanning line and the signal line is detected, the inspection signal is sequentially applied in the corresponding block so that the scanning line and the signal line Before the scanning line or the signal line including the short-circuited point is moved by performing precise identification of the short-circuited point and moving the stage carrying the matrix type image display device or the beam irradiation port of the laser. Inspection method of correcting matrix type image display device for fusing the scanning lines or the signal lines by irradiating a laser beam to the two positions sandwiching the short-circuited portion. 2. The matrix according to claim 1, further comprising a step of performing a re-inspection for confirming that the short-circuited portion is opened after the laser fusing of the short-circuited portion between the scanning line and the signal line. Method for inspection and correction of mold image display device. 3. A means for applying an inspection signal to all the scanning lines and signal lines of a matrix type image display device having scanning lines and signal lines divided into a plurality of blocks, and the same for a plurality of scanning lines for each block. Test signal source having a means for simultaneously applying the same test signal to a plurality of signal lines for each block, and a test from the scan signal source for a plurality of scan lines at the same time for each block. In addition to applying a signal, an inspection signal is applied to a plurality of signal lines at the same time to measure the leak current in the scanning line and the signal line to detect the presence or absence of a short circuit, and if there is a short circuit, the inspection is performed in the corresponding block. Means for precisely identifying a short circuit portion by sequentially applying a signal to a scanning line and a signal line, and the scanning of the short circuit portion in the matrix type image display device identified by this means Alternatively, a matrix type image including a laser for melting the signal line, and means for moving the beam irradiation port of the laser to irradiate the beam of the laser to an arbitrary position in the matrix type image display device Inspection and correction device for display device.