KR102081815B1 - Method and apparatus for testing a tft panel - Google Patents

Abstract

Disclosed is a thin film translator (TFT) panel test method. The TFT panel at least includes a display area and a neighboring area surrounding the display area. The display area includes a first display side and a second display side facing the first display side, and the neighboring area includes a plurality of functional test pads. The method includes the following steps of: providing a plurality of probes and at least one sensing part; placing the probes on the functional test pads to input a set of electric signals into the functional test pads; and placing at least one sensing part on a sensing position adjacent to the first display side and receiving sensing signals along the first display side through a non-contacting method.

Description

TFT panel test method and apparatus {METHOD AND APPARATUS FOR TESTING A TFT PANEL}

FIELD OF THE INVENTION The present invention relates to test methods and test apparatus, and more particularly, to a method and apparatus for testing thin film transistor panels in a production line.

A typical TFT LCD device, such as the Thin Film Transistor (TFT) Liquid Crystal Display (LCD) device 1 of FIG. 1A, has a backlight module 3 at the back, a color filter substrate 5 at the front, and an intermediate Is composed of a TFT substrate 10. The light emitting devices 301/302 disposed at both ends of the backlight module 3 may emit light simultaneously in different directions. These lights become a plurality of parallel lights upwards through different paths in a combination of reflection and refraction, and sequentially pass through the TFT substrate 10 and the color filter substrate 5.

The TFT substrate 10 has a TFT array formed on a glass substrate. The TFT array consists of circuit lines in the longitudinal directions and the TFT transistors formed therebetween, and is manufactured through multilayer processes. Such as a so-called open-short test on the TFT substrate 10 at the front of the production line, so that any defects present in the TFT array can be identified and timely repaired or reworked when necessary. You need to perform a test.

At present, TFT elements of high pixel-density TFT panels no longer provide space for placing test pads used for input or output of test signals to minimize the area occupied by each pixel. . Therefore, the existing probing methods are no longer applicable and are replaced by non-contacting methods for open-short test.

FIG. 1B shows an example of an open-short test according to the prior art performed on a TFT substrate 10 having a circuit line 12 on its surface. Referring to FIG. 1B, the distances on the surface of the TFT substrate 10 on which signal sensing heads 11 and 13 for transmitting and receiving sensing signals respectively (see black arrows indicating the direction of signal transmission) are tested. Placed with DP (eg 100-150 micrometers). Test signals shown as waveforms on the surface of the TFT substrate 10 are transmitted from left to right along the circuit line 12. The received signal is processed by the magnifier 14 before being analyzed. In FIG. 1B, the signal change SC occurs when a defect 17 is present in the circuit line 12, and the received signal can be used to determine whether the circuit line 12 is acceptable.

In the above technical solution, the non-contact method usually uses capacity coupling. However, capacitive couplings at each end can lead to significant signal reductions in terms of intensity and resolution, and can cause difficulties in subsequent analysis. In addition, the non-contact method through capacitive coupling is applied only to the display area test of the TFT panel, thereby limiting the test range. For peripheral areas, such as gate drive on array (GOA) or gate drive on panel (GOP) areas, the driving IC circuit line from the final assembly to the functional test phase. Can't test them If a defect exists in the driver IC circuit, and the defect is not found and not repaired in a timely manner immediately after the circuit production process, the repair process after the final assembly step is much more expensive in terms of time and materials.

Thus, there is a need to develop new devices and methods for testing thin film transistor (TFT) panels in production lines, particularly for testing driving IC circuit lines prior to final assembly.

According to one aspect of the invention, a method of testing a thin film transistor (TFT) panel is disclosed. The TFT panel includes at least a display area and a peripheral area surrounding the display area, the display area including a first display side and a second display side opposite the first display side, the peripheral area being a plurality of Functional test pads. The method comprises: providing a plurality of probes and at least one sensing unit; Placing a plurality of probes on the plurality of functional test pads to input a set of electrical signals to the plurality of functional test pads; Disposing a sensing unit at a sensing position adjacent the first display side and receiving the sensing signal in a non-contacting method along the first display side.

According to another aspect of the present invention, an apparatus for testing a TFT panel is disclosed. The TFT panel includes at least a display area and a peripheral area surrounding the display area. The display area includes a first display side and a second display side opposite the first display side, and the peripheral area includes a plurality of functional test pads. The apparatus includes a plurality of probes configured to input a set of electrical signals to a plurality of functional test pads; And at least one sensing unit disposed at a specific sensing position adjacent to the first display side and receiving sensing signals in a non-contact manner along the first display side.

According to another aspect of the present invention, an open-short test is performed on a matrix panel including at least an display area including an edge and a peripheral area surrounding the display area. A method is disclosed. The display area includes a shorting bar circuit disposed on the display area and having a plurality of longitudinal conducting lines and a plurality of transverse conducting lines, the peripheral area Includes a plurality of functional test pads. The method includes inputting a set of electrical signals to the plurality of functional test pads by a contacting method; And receiving the sensing signal in a non-contact manner at a sensing position adjacent to an edge of the display area.

The apparatus and method described above are applicable to automatic testing in production lines such as TFT panel manufacturing. Accordingly, the present invention has industrial applicability.

The objects and advantages of the present invention will become more readily apparent to those skilled in the art after reviewing the following detailed description and the accompanying drawings.

1A shows a typical TFT LCD device
1B shows an example of an open-short test performed on a TFT substrate according to the prior art.
2A and 2B illustrate a TFT panel test method and apparatus according to an embodiment of the present invention.
3 is a diagram illustrating an embodiment of detecting electronic signals by a non-contact method using a first coupling unit according to the present invention.
4 shows a shorting bar circuit on a TFT substrate.

The invention will be explained in more detail with reference to the following examples. It should be noted that the following description of the preferred embodiments has been presented for purposes of illustration and description only, and is not intended to be limiting to the precise form disclosed.

2A and 2B illustrate a method and apparatus for testing a thin film transistor (TFT) panel according to an embodiment of the present invention. 2B shows an example of an entire glass substrate 100 that includes several portions, such as four portions, which will be separate TFT substrates 200 after being separated from the glass substrate 100. One skilled in the art can design a predetermined number of different regions for a TFT substrate on a single glass substrate according to different applications for simultaneously manufacturing multiple TFT circuits.

2A shows one of the predetermined portions for manufacturing the TFT substrate 200 on the glass substrate 100 to introduce the TFT panel test method and apparatus according to the present invention. The TFT substrate 200 surrounds the display area and at least one display area 210 including a first display side 213, a second display side 217, and a third display side 215. Surrounding area. The peripheral region includes a first peripheral side 230, a second internal circuit line including a first internal circuit line region 231, a first driver IC 233, and a first external circuit line region 235. Second peripheral side 270 and third internal circuit line region 251 including region 271, second driver IC 273 and second external circuit line region 275, third driver IC 253. And a third peripheral side 250 including a third external circuit line region 255. The plurality of functional test signal input pads 2351, 2751, and 2551 may include a first external circuit line region 235, a second external circuit line region 275, and a third external circuit line region ( 255) respectively. According to the existing design, the functional test signal input pads 2351, 2751 and 2551 should be used for signal input when performing the functional test in a subsequent backend process after the TFT LCD device is fully assembled. .

Those skilled in the art will appreciate that the display area 210 of the TFT substrate 200 includes transverse and longitudinal conducting lines in which criss-crossly are arranged, and a TFT matrix array. ) Is formed of a plurality of thin film transistors, and each of the plurality of thin film transistors is positioned near a cross section of the lateral and longitudinal conductive lines on the substrate 200. Referring to FIG. 2A, the first display side 213 faces the second display side 217, and the first display side 213, the second display side 217 and the third display side 215 are respectively. It is located adjacent to the first peripheral side 230, the second peripheral side 270, and the third peripheral side 250.

According to the conventional test method described above, the sensing devices with the transmitting and sensing elements are arranged and open-sided on two opposing sides, for example, each of the first and second display sides 213 and 217 of FIG. 2A. Perform an open-short test. Both sensing devices can be placed adjacent to each end of the transverse conducting line and can move up or down simultaneously to sequentially test each of the transverse conducting lines. In order to improve test efficiency, a pair of sensing devices, each consisting of two sensing elements and two transmitting elements, can be employed to simultaneously perform a test on a pair of lateral conducting lines.

According to one embodiment of the invention, after finishing each layer, such as PEP1, PEP3 or PEP5, on the TFT substrate 200 in the production line, a plurality of probes for inputting the set of electrical test signals (S1 to S13) Probes 41 may be disposed on the plurality of functional test pads 2351, respectively, and sense signals (not shown) along vertical or longitudinal edges of the display area 210. To sequentially receive the first sensing unit 31 and the second sensing unit 32 from two opposite sides of the display area 210 (eg, the first display side 213 and the second display). Each of the side surfaces 217. For example, referring to the left portion of FIG. 2A, a person of ordinary skill in the art may include a first including a first internal circuit line region 231, a first driver IC 233, and a first external circuit line region 235. The production quality of the circuit lines on the peripheral side 230 can be detected by analyzing the signals collected from the first sensing unit 31, and likewise, the production quality of the lateral conducting lines in the display area 210 is It can be seen that it can be detected by analyzing the signals collected from the second sensing unit 32 moving along the second display side 217.

According to an embodiment of the present invention, the electrical test signals S1, S2 through S13 may include an initiating signal ST, a clock CK / XCK, a common grounding end voltage VSS, and an operation. Various details and combinations, such as working voltage VDD and the like. Therefore, the present invention can perform an open-short test immediately after completion of each layer of the TFT substrate 200, and when defects are found in the tested circuits, timely preparation for rework or repair can be achieved. Reduce effectively.

One embodiment described above is, for example, inputting the sets of signals S1 to S13 into the functional test pads 2251 on the first peripheral side 230, respectively. Similarly, to sequentially receive sensing signals (not shown) along the vertical or longitudinal edges of display area 210, a set of signals S1 through S13 are functional test pads on second peripheral side 270. And a first sensing unit 31 and a second sensing unit 32, respectively, on the first display side 213 and the second display side 217 of the display area 210. can do. Referring to the right part of FIG. 2A, a person of ordinary skill in the art may include a second peripheral side surface 270 including a second internal circuit line region 271, a second driving IC 273, and a second external circuit line region 275. The production quality of the circuit lines on) can be detected by analyzing the signals collected from the second sensing unit 32, and likewise, the production quality of the lateral conducting lines in the display area 210 is determined by the first display side ( It can be appreciated that it can be detected by analyzing signals collected from the first sensing unit 31 moving along 213.

Alternatively, a plurality of probes for inputting electrical test signals (not shown) for the purpose of inspecting longitudinal conducting lines in the display area 210 and circuit lines on the third peripheral side 250. Can be disposed on the plurality of functional test pads 2551 on the third external circuit line region 255, respectively, and sense signals (not shown) along the horizontal or transverse edges of the display region 210. ) To sequentially receive the first sensing unit 31 and the second sensing unit 32 from the two opposite sides of the display area 210 (eg, the third display side 215 and the third display). On the side facing the side 215).

According to an embodiment of the present invention, the first sensing unit 31 includes a first coupling unit 311 and a second coupling unit 312, and a second sensing unit 32 includes another set of first coupling portions 321 and second coupling portions 322. The first coupling units 311 and 321 may receive signals through electromagnetic coupling, and the second coupling units 312 and 322 may receive signals through capacity coupling. . The device configuration of the first coupling section 311, 321 differs from the device configuration of the second coupling section 312, 322 because of different ways of non-contacting signal coupling. According to one embodiment of the invention, the pair of first and second detectors 31 and 32 perform inspection of the circuit lines sequentially in each predetermined area with respect to the TFT substrate 200 on the glass substrate 100. To be employed. According to other embodiments of the present invention, in order to increase the efficiency, a plurality of pairs of first and second sensing units 31 and 32 are arranged in a plurality of predetermined areas of the TFT substrate 200 on the glass substrate 100. Is used to simultaneously check circuit lines.

3 is a diagram illustrating an embodiment of detecting electronic signals by a non-contact method using a first coupling unit according to the present invention. The first coupling part 311 is used as an example for explaining the concept. Those skilled in the art will appreciate that other first coupling portions may have the same structure and features and need not be described repeatedly. In FIG. 3, the first coupling portion 311 includes a set of coils 311A arranged in a concentric manner, an outer conductive line 311B connected to the outer coil, and an inner conductive line 311C connected to the inner coil. Include. Claim When the first coupling unit 311 is placed on top of the metal plate 61, the set (311A) of the coils is eddy current (eddy current) to occur at a position corresponding to the first engagement portion 311 located at the (I _Eddy) The magnetic field E can be detected along the direction perpendicular to the metal plate 61, and a voltage V is generated between the outer and inner conductive lines 311B and 311C, so that the outer and inner conductive lines 311B can be detected. , 311C) may detect a sensing current (I _sensor ). In other embodiments, the second coupling portions 312 and 322 can also be composed of electromagnetic coupling devices, and vice versa.

The present invention has the advantage of a contact method for directly inputting a signal for inspection, thereby avoiding problems such as signal deviation or distortion due to the process of signal coupling, The input signal quality is much better than that of the electrical test signals input by the non-contact schemes described in the prior art methodology. Therefore, the test method and apparatus of the TFT substrate according to the present invention can have an advantageous testing effect.

4 is a diagram illustrating an example of a shorting bar circuit on a TFT substrate. Shorting bar circuits are widely used in TFT substrate design circuits. In FIG. 4, on the TFT substrate 401, a plurality of odd-numbered data lines Data O and even-numbered data lines Data E arranged side by side in a vertical direction or a longitudinal direction in the vertical direction. ), A plurality of odd-numbered gate lines (Gate O) and even-numbered gate lines (Gate E) and ground lines (COM) disposed adjacent to each other along a horizontal direction or a transverse direction. The common constitutes a shorting bar circuit. The structure of the shorting bar circuit can be used for further inspection of the circuit lines, since such circuit structure becomes the standard of circuit design in common TFT substrate configurations.

In particular, the combination of the vertical data lines Data O, Data E and the horizontal gate lines Gate O, Gate E are transverse and longitudinal conductive lines arranged crosswise on the TFT substrate 200 in FIG. 2A. The odd-numbered data lines Data O, the even-numbered data lines Data E, the odd-numbered gate lines Gate O, and the even-numbered gate lines Gate E are connected to each other. . If different electrical signals flow through two adjacent gate lines Gate O and Gate E, there will be voltage differences between them. Thus, unexpected micro-defects, such as bad insulation or particle contamination, can cause currents to cause signal changes. Referring again to FIG. 2A, according to one embodiment of the present invention, a plurality of probes 41 may input electrical signals S1, S2... Into the functional test pads 2351, 2551 or 2771. When there is a voltage difference between any two adjacent conductive lines under test. Based on this configuration, the test capability of the open-short test on the TFT matrix array in the display region 210 of the TFT substrate can be significantly improved.

Based on the above description, the sensing signals received by the sensing elements 31, 32 are passed through the electrical signals S1 passing through the conductive lines of the peripheral region 230, 250, 270 or the display region 210 under test. To S13), and are obtained by non-contact schemes at the other end of the conductive lines under test. According to the examples shown in FIG. 2, sensing signals received by the first sensing element 31 disposed adjacent to the functional test signal input pads 2351 are conductive lines disposed on the first peripheral side 230. May reflect defects present within. Likewise, sensing signals received by the second sensing element 32 disposed remote from the functional test signal input pads 2351 can reflect defects present in the horizontal conductive lines disposed in the display area 210. have. In some embodiments, Automatic Optical Inspection devices are employed to verify the location and type of defects.

Compared to the non-contact schemes in signal input and output according to the prior art, which requires both emitting and receiving elements at each end of the TFT substrate 10 under test, the present invention uses low cost probes for inputting a test signal. The sensing elements 31, 32 are therefore only required for the receiving elements and thus have the added advantage of low cost and low volume for manufacturing devices.

Examples

1. at least a display area and a peripheral area surrounding the display area, the display area including a first display side and a second display side opposite the first display side, the peripheral area comprising a plurality of functional test pads In one embodiment, a TFT panel test method includes providing a plurality of probes and at least one sensing unit; Placing a plurality of probes on the plurality of functional test pads to input a set of electrical signals to the plurality of functional test pads; And placing the sensing unit at a sensing position adjacent to the first display side and receiving the sensing signals in a non-contact manner along the first display side.

2. The method of embodiment 1, wherein the peripheral region comprises a first peripheral side adjacent to the first display side and a second peripheral side near the second display side and the plurality of functional test pads are disposed on the first peripheral side and The detection signals show test results that show whether there are line defects in the surrounding area.

3. The method of the above-described embodiments, wherein the peripheral region includes a drive IC circuit and a line circuit region, and the non-contact scheme includes one of an electromagnetic coupling and a capacitive coupling.

4. The method of embodiment 1, wherein the TFT panel comprises a shorting bar circuit disposed on the display area and comprising a plurality of longitudinal conductive lines and a plurality of transverse conductive lines, wherein the set of electrical signals is provided with a plurality of functions. When input to the test pads, there is a voltage difference between two adjacent longitudinal conducting lines or two adjacent transverse conducting lines under test.

5. at least a display area and a peripheral area surrounding the display area, the display area including a first display side and a second display side opposite the first display side, the peripheral area including a plurality of functional test pads A TFT panel test apparatus comprising: a plurality of probes for inputting a set of electrical signals into a plurality of functional test pads; And at least one sensing unit disposed at a specific sensing position adjacent to the first display side and receiving sensing signals in a non-contact manner along the first display side.

6. The apparatus of embodiment 5, wherein the peripheral area comprises a first peripheral side adjacent to the first display side and a second peripheral side adjacent to the second display side and the plurality of functional test pads are disposed on the first peripheral side and The sensing signals represent test results showing whether there is a line defect in the peripheral area, the peripheral area includes a driving IC circuit and a line circuit area, and the non-contact method includes one of an electromagnetic coupling and a capacitive coupling.

7. a shorting bar circuit comprising a display area comprising at least an edge and a peripheral area surrounding the display area, the display area comprising a plurality of longitudinal conductive lines and a plurality of transverse conductive lines and disposed on the display area And wherein the peripheral area comprises a plurality of functional test pads, the method of performing an open-short test on a matrix panel comprising: inputting a set of electrical signals to the plurality of functional test pads by a contact method; step; And receiving the sensing signals in a non-contact manner at a sensing position adjacent the edge of the display area.

While the present invention has been described with respect to what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment. On the contrary, the intention is to cover various modifications and similar arrangements falling within the spirit and scope of the appended claims consistent with the broadest interpretation so as to encompass all such modifications and similar structures.

1: TFT LCD device
3: backlight module
5: color filter substrate
10, 200, 401: TFT substrate
11, 13: signal detection head
12: circuit line
14: Magnifier
17: Defect
31: first detection unit
32: second detection unit
41: probe
61: metal plate
100: glass substrate
210: display area
213: first display side
215: third display side
217: second display side
230: first peripheral side
231: first internal circuit line region
233: first driving IC
235: first external circuit line region
250: third peripheral side
251: third internal circuit line region
253: third drive IC
255: third external circuit line region
270: second peripheral side
271: second internal circuit line region
273: second drive IC
275: second external circuit line region
301 and 302: light emitting element
311 and 321: first coupling part
311A: set of coils
311B: external conductive line
311C: internal conductive line
312, 322: second coupling portion
2351, 2551, 2751: Function test signal input pad

Claims (7)

At least a display area and a peripheral area surrounding the display area, the display area including a first display side and a second display side opposite the first display side, the peripheral area being a plurality of A thin film transistor (TFT) substrate test method prior to final assembly process, comprising functional test pads of
Providing a plurality of probes and at least one sensing unit;
Placing the plurality of probes in the plurality of functional test pads to input a set of electrical signals to the plurality of functional test pads; And
Disposing the sensing unit at a sensing position adjacent to the first display side and receiving sensing signals in a non-contacting method along the first display side,
The peripheral region includes a first peripheral side adjacent to the first display side and a second peripheral side adjacent to the second display side, wherein the plurality of functional test pads are disposed at the first peripheral side and And the sensing signals represent test results showing whether there is a line defect in the peripheral region, and wherein the non-contacting method includes electromagnetic coupling. The method according to claim 1,
And the peripheral region comprises a driver IC circuit and a line circuit region. The method according to claim 1,
The TFT substrate includes a shorting bar circuit including a plurality of longitudinal conducting lines and a plurality of transverse conducting lines and disposed on the display area. And there is a voltage difference between two adjacent longitudinal conducting lines or two adjacent transverse conducting lines under test when the set of electrical signals is input to the plurality of functional test pads. At least a display area and a peripheral area surrounding the display area, the display area including a first display side and a second display side opposite the first display side, the peripheral area being a plurality of A thin film transistor (TFT) substrate test device prior to final assembly process, comprising functional test pads, comprising:
A plurality of probes for inputting a set of electrical signals to the plurality of functional test pads; And
At least one sensing unit disposed at a specific sensing position adjacent the first display side and receiving sensing signals along the first display side in a non-contacting method,
The peripheral region includes a first peripheral side adjacent to the first display side and a second peripheral side adjacent to the second display side, wherein the plurality of functional test pads are disposed at the first peripheral side and And the sensing signals indicate test results indicating whether there is a line defect in the peripheral area, and wherein the non-contact method includes an electromagnetic coupling. The method according to claim 4,
And the peripheral region comprises a driving IC circuit and a line circuit region. delete delete

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