KR20150081798A - Method of inspecting display cells - Google Patents

Abstract

A method to inspect display cells on a substrate is capable of obtaining inspection images about a plurality of display cells formed on a substrate by using an inspecting device, and automatically determining the quality of the display cells based on the inspection images. An inspection image about an indeterminable display cell among the display cells is transmitted to an inspection server, and the quality of the indeterminable display cell is manually determined through inspection on the inspection image, transmitted to the inspection server, with naked eyes. Moreover, the manually determined result is transmitted to the inspection device, and the automatically-determined result and the manually-determined result are integrated and transmitted to a process management server.

Description

Method of inspecting display cells < RTI ID = 0.0 >

Embodiments of the present invention are directed to a method of inspecting display cells. More particularly, to a method of optically inspecting a plurality of display cells formed on a mother substrate (hereinafter, referred to as 'substrate') such as OLED (Organic Light Emitting Device) cells.

The OLED device used as a flat panel display device is widely used in portable display devices, smart phones, tablet PCs, and the like, as well as being widely used as a next-generation display device due to its large size, having a wide viewing angle, excellent contrast and high response speed . In particular, the OLED device has advantages such as brightness, driving voltage, response speed, etc., and is capable of multi-coloring as compared with an inorganic light emitting display device.

In the manufacturing process of the OLED device, a TFT (Thin Film Transistor) layer is formed on the substrate through various film forming processes and etching processes, and on the TFT layer, a lower electrode and an organic layer (for example, a hole transport layer, Transport layer) and an upper electrode may be formed. Then, the OLED device can be completed by sealing the TFT layer and the substrate on which the organic light emitting layer is formed using an encapsulating substrate.

In particular, a plurality of OLED cells may be formed on the substrate, and after the sealing process is completed, individual OLED cells may be individualized through a cutting process to complete the OLED device.

Meanwhile, after the sealing process is completed, an inspection process for OLED cells formed on the substrate may be performed. In the inspection process, a function test of the TFT layer, a correction circuit inspection, an image quality inspection, a spectral inspection, an image inspection, and the like may be performed by applying an inspection signal to the OLED cells. However, since the inspecting process is performed after the sealing process is completed as described above, the loss due to the defective OLED devices in the inspecting process may be increased.

In order to solve the above problems, Japanese Unexamined Patent Application Publication No. 10-2006-0017586 discloses a method of performing the TFT array function test before performing the cell process after the TFT array forming process, -0046645 and 10-2011-0096382 disclose a method for measuring the thickness of the thin film layers during or after forming each thin film layer of OLED cells.

However, even if the function test for the TFT array and / or the thickness measurement for the thin film layers forming the organic light emitting layer are performed as described above, since the final inspection processes must be additionally performed after the sealing process is performed, There is a possibility that the productivity of the apparatus is deteriorated.

In Korean Patent Application No. 10-2012-0120865 filed by the present applicant, in order to solve the above-mentioned problems, it is possible to perform an inspection process on display cells such as a plurality of OLED cells formed on a substrate before a sealing process An apparatus for inspecting display cells is disclosed, and an apparatus for inspecting the display cells is being continuously researched and developed.

Meanwhile, the inspection apparatus for the display cells may perform optical inspection of OLED cells formed on the substrate. For this purpose, the inspection apparatus includes an inspection camera for inspecting image quality such as color tone, brightness and the like for the OLED cells, a spectroscope for measuring wavelength, luminance, luminance, color coordinates, color temperature and the like of each OLED cell, And a fluorescent microscope for checking the alignment accuracy of the thin film patterns formed on the substrate. The optical inspection of the OLED cells may be performed automatically using a reference value and / or a reference image.

However, in the process of automatically performing the image quality check, it may happen that automatic determination can not be performed on the display cells due to spots, haze, cracks, or the like. If an error is generated in the automatic determination process as described above, the inspection process may be stopped until a follow-up action is taken by the operator, thereby greatly reducing the operation rate of the display cell inspection apparatus.

It is an object of the present invention to provide a display cell inspection method capable of improving the operation rate of the display cell inspection apparatus by preventing the inspection process from being stopped by an automatic judgment error in the display cell inspection apparatus.

According to embodiments of the present invention, a method of inspecting display cells comprises the steps of: obtaining inspection images for a plurality of display cells formed on a substrate using an inspection apparatus; The method comprising the steps of: automatically judging whether a display cell is a display cell or not; transmitting a test image for a display cell which is not judged in the display cells to an inspection server; Manually transmitting the manual determination result to the inspection apparatus, and transmitting the automatic determination result and the manual determination result to the process management server.

According to embodiments of the present invention, it is possible to determine whether the image quality of the display cells is within a predetermined range in the automatic determination step and the manual determination step.

According to embodiments of the present invention, a spectroscopic inspection of the display cells may be performed together while performing the automatic determination of the display cells.

According to embodiments of the present invention, the step of generating the alarm signal after transmitting the inspection image to the inspection server may be further performed.

According to embodiments of the present invention, after the automatic determination step is performed, an alignment accuracy check may be performed between patterns constituting the display cells.

According to embodiments of the present invention, the alignment accuracy inspection can be performed by a fluorescence microscope.

According to embodiments of the present invention, the steps may be performed between a cell process for forming the display cells on the substrate and an encapsulation process for encapsulating the display cells.

According to embodiments of the present invention, if the visual inspection is delayed, the substrate may be temporarily stored in the buffer chamber of the inspection apparatus and an inspection process for the subsequent substrate may be performed.

According to embodiments of the present invention, the inspection images can be obtained with an inspection signal applied to the inspection pads of the display cells using the probe card.

According to embodiments of the present invention, the display cells may be arranged to have a plurality of rows and columns on the substrate, and the probes of the probe card may be arranged in a row or column direction of the display cells, Can be contacted simultaneously with the cells.

According to embodiments of the present invention, the inspection signal can be sequentially applied to the display cells contacted with the probes of the probe card, and the inspection images can be sequentially obtained according to the application of the inspection signal.

According to embodiments of the present invention, merging the inspection images for the display cells to generate the entire image of the substrate, and transmitting the entire image of the substrate to the inspection server.

According to embodiments of the present invention, the entire image of the substrate may be transmitted to the process management server together with the integrated automatic determination result and the manual determination result.

According to the exemplary embodiments of the present invention as described above, it is possible to perform manual inspection of a cell that can not be automatically determined during the automatic inspection of display cells such as OLED cells formed on a substrate, The image may be transmitted to the inspection server and subsequently the inspection process for subsequent cells may be performed continuously.

In addition, even if the manual judgment by the operator is delayed, the substrate on which the uncertain cell is generated can be temporarily stored in the buffer chamber and the inspection process for the subsequent substrate can be continuously performed.

As a result, the apparatus for inspecting the display cells can be prevented from being stopped by the automatic judgment error, whereby the operation rate of the inspection apparatus can be greatly improved.

1 is a schematic diagram for explaining OLED cells formed on a substrate.
2 is a schematic block diagram illustrating an inline process facility to which an apparatus for testing display cells is connected.
FIG. 3 is a schematic block diagram illustrating an apparatus for testing the display cells shown in FIG. 2. FIG.
4 is a flowchart illustrating a method of testing display cells according to an exemplary embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail below with reference to the accompanying drawings showing embodiments of the invention. However, the present invention should not be construed as limited to the embodiments described below, but may be embodied in various other forms. The following examples are provided so that those skilled in the art can fully understand the scope of the present invention, rather than being provided so as to enable the present invention to be fully completed.

When an element is described as being placed on or connected to another element or layer, the element may be directly disposed or connected to the other element, and other elements or layers may be placed therebetween It is possible. Alternatively, if one element is described as being placed directly on or connected to another element, there can be no other element between them. The terms first, second, third, etc. may be used to describe various items such as various elements, compositions, regions, layers and / or portions, but the items are not limited by these terms .

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Furthermore, all terms including technical and scientific terms have the same meaning as will be understood by those skilled in the art having ordinary skill in the art, unless otherwise specified. These terms, such as those defined in conventional dictionaries, shall be construed to have meanings consistent with their meanings in the context of the related art and the description of the present invention, and are to be interpreted as being ideally or externally grossly intuitive It will not be interpreted.

Embodiments of the present invention are described with reference to schematic illustrations of ideal embodiments of the present invention. Thus, changes from the shapes of the illustrations, e.g., changes in manufacturing methods and / or tolerances, are those that can be reasonably expected. Accordingly, the embodiments of the present invention should not be construed as being limited to the specific shapes of the areas illustrated in the drawings, but include deviations in the shapes, the areas described in the drawings being entirely schematic and their shapes Is not intended to illustrate the exact shape of the area and is not intended to limit the scope of the invention.

FIG. 1 is a schematic structural view for explaining OLED cells formed on a substrate, FIG. 2 is a schematic structural view for explaining an inline processing facility to which an apparatus for inspecting display cells is connected, and FIG. 3 is a cross- Fig. 5 is a schematic configuration diagram for explaining an apparatus for testing display cells shown in Fig.

Referring to FIGS. 1 to 3, an apparatus 100 for testing display cells according to an exemplary embodiment of the present invention may be used to electrically and optically inspect display cells such as OLED cells 20. FIG.

Specifically, the inspection apparatus 100 of the OLED cells 20 uses a cell process for forming a plurality of OLED cells 20 on the substrate 10 and an encapsulation substrate (not shown) in the manufacturing process of the OLED device May be used to inspect the electrical and optical characteristics of the OLED cells 20 during the sealing process for sealing the OLED cells 20. [

In particular, as shown in FIG. 2, the inspection apparatus 100 according to an embodiment of the present invention may be connected to an in-line process facility for manufacturing the display cells 20. For example, the testing apparatus 100 may be connected between the cell processing facility 30 for the cell process and the sealing process facility 40 for the sealing process. For example, the cell processing facility 30 and the sealing process facility 40 may have a cluster shape, and the substrate 10 may be transferred between the cell processing facility 30 and the sealing process facility 40 An in-line substrate transfer device 50 may be disposed. According to an embodiment of the present invention, the inspection apparatus 100 may be connected to the in-line substrate transfer apparatus 50 between the cell process facility 30 and the sealing process facility 40, 30 may be used to perform electrical and optical inspection processes on OLED cells 20 formed on the substrate 10.

The substrate 10 can be transferred from the cell processing facility 30 to the inspection apparatus 100 via the in-line substrate transfer apparatus 50 and the inspection and inspection process And then transferred to the sealing process facility 40 through the in-line substrate transfer device 50.

As described above, since the electrical and optical inspection process for the substrate 10 can be performed after the cell process and before the sealing process, the defect rate of the OLED cells 20 can be greatly reduced, It is possible to omit subsequent processes for the OLED cells 20 determined to be the OLED cells 20, thereby greatly reducing the manufacturing cost of the OLED cells 20. [

The cell process includes forming a plurality of OLED cells 20 on a substrate 10, forming a TFT array layer on the substrate 10 and forming an organic emission layer on the TFT array layer Lt; / RTI > For example, the organic light emitting layer may include a lower electrode layer, a hole transporting layer, a light emitting layer, an electron transporting layer, an upper electrode layer, and the like. 1, the OLED cells 20 formed on the substrate 10 in the cell process each have a plurality of test pads 22 electrically connected to the TFT array layer .

The sealing process may be performed after the cell process by sealing the OLED cells 20 by bonding the substrate 10 on which the OLED cells 20 are formed and the sealing substrate.

The inspection apparatus 100 may include an inspection chamber 102 providing a space for performing electrical and optical inspection processes on the OLED cells 20. [ That is, the substrate 10 can be transferred from the cell processing facility 30 to the inspection chamber 102 and then transferred from the inspection chamber 102 to the sealing process facility 40 after the inspection process is performed. .

According to an embodiment of the present invention, the inspection apparatus 100 may include a substrate transfer module 200 for transferring the substrate 100 between the inspection chamber 102 and the inline process facility. The substrate transfer module 200 includes a substrate transfer chamber 202 connected to the inspection chamber 102 and a substrate transfer chamber 202 disposed within the substrate transfer chamber 202 for transferring the substrate 100 between the inspection chamber 102 and the in- And a substrate transfer robot 204 for transferring the substrate.

The substrate transfer robot 202 may be connected between the inspection chamber 102 and the inline substrate transfer apparatus 50 and the substrate transfer robot 204 may be connected to the inline substrate transfer apparatus 50 And the substrate 10 can be transferred from the inline substrate transfer robot 52 provided in the substrate processing apparatus 100. [

The substrate 10 may be transferred into the substrate transfer chamber 202 by the inline substrate transfer robot 52 and may be transferred to the inline substrate transfer robot 52 And a substrate alignment unit 210 for aligning the substrate 10 transferred by the substrate transfer robot 204 and transferring the substrate 10 to the substrate transfer robot 204.

Although not shown, a buffer chamber (not shown) for temporarily storing the substrate 10 may be connected to the substrate transfer chamber 202.

In the inspection chamber 102, a substrate stage 110 for supporting the substrate 10 may be disposed. The substrate 10 may be transferred into the inspection chamber 102 with the front surface of the OLED cells 20 facing downward and the substrate stage 110 may be configured to adsorb the backside of the substrate 10 A plurality of vacuum holes may be provided. Also, although not shown in detail, the substrate stage 110 can move the substrate 10 in the horizontal and vertical directions by the stage driving unit, and can also rotate the substrate 10.

A probe card 120 for inspecting the OLED cells 20 formed on the substrate 10 may be disposed below the substrate stage 110. The probe card 120 may include probes for contact with the OLED cells 20 and the substrate stage 110 may be positioned between the probes of the probe card 120 and the OLED cells 20 So that it can be moved in the vertical direction.

The probe card 120 may be disposed on the card stage 122 and the probe card 120 may be electrically connected to an electrical inspection unit (not shown) for providing an electrical inspection signal to the OLED cells 20 Can be connected.

Meanwhile, the inside of the inspection chamber 102 may be formed with an inert gas, for example, a nitrogen gas atmosphere to prevent the substrate 10 from coming into contact with outside air during the inspection process.

The electrical inspection unit may perform an electrical characteristic inspection of the OLED cells 20 to which the inspection signal is applied through the probe card 120.

In addition, the inspection apparatus 100 may perform optical inspection of the OLED cells 20 to which the inspection signal is applied. For this purpose, the inspection apparatus 100 may include an optical inspection unit 130 for the optical inspection. Although not shown in detail, the optical inspection unit 130 includes an inspection camera 132 for inspecting image quality such as color tone, brightness, etc. of the OLED cells 20, A spectroscope 134 for measuring color temperature and the like, and a fluorescence microscope 136 for inspecting an alignment state of thin film patterns formed on the substrate 10, and the like.

The electrical inspection may be performed sequentially or simultaneously with the OLED cells 20 in contact with the probes of the probe card 120 and the optical inspection may be performed sequentially with respect to the OLED cells 20 . For this, the optical inspection unit 130 may include driving units for moving the inspection camera 132, the spectroscope 134, and the fluorescence microscope 136.

According to an embodiment of the present invention, optical inspection of the OLED cells 20 may include image quality inspection, spectroscopy and fluorescence microscopy for the OLED cells 20. [ In particular, the image quality inspection and the spectroscopic inspection may be performed together, and the fluorescence microscopy inspection may be performed after the image quality inspection and the spectroscopic inspection are completed. For example, the image quality inspection and spectroscopy can be performed in a state where the OLED cells 20 are lighted by applying an inspection signal to the OLED cells 20 using the probe card 120, The probe card 120 may not be used for the microscopic examination.

4 is a flowchart illustrating a method of testing display cells according to an exemplary embodiment of the present invention.

Referring to FIG. 4, first, in step S100, inspection images for the OLED cells 20 formed on the substrate 10 are obtained. The inspection images are applied to the OLED cells 20 after the probes of the probe card 120 contact the inspection pads 22 of the OLED cells 20, Can be obtained in the lighted state.

In particular, the inspection images can be obtained by the inspection camera 132. [ 1, the OLED cells 20 may be disposed on the substrate 10 in the form of a plurality of rows and columns, and the probes of the probe card 120 may be arranged in the row direction or the column direction Lt; RTI ID = 0.0 > OLED cells 20 < / RTI >

The inspection signal may be sequentially applied to the OLED cells 20 in contact with the probes of the probe card 120, and the inspection images may be sequentially obtained according to the application of the inspection signal.

Subsequently, in step S110, a positive judgment of the OLED cells 20 is automatically performed based on the obtained inspection images. The automatic ON / OFF determination of the OLED cells 20 can be automatically performed by the control unit 104 of the inspection apparatus 100. For example, it is possible to determine whether the image quality of the OLED cells 20 is within a predetermined range. That is, it can be determined whether the color tone and brightness of the OLED cells 20 are uniformly within a preset range. If the image quality of the OLED cells 20 is out of the predetermined range, It can be judged to be defective.

The inspection images may be sequentially acquired by the inspection camera 132, and the automatic determination step S110 may be sequentially performed on the sequentially obtained inspection images.

On the other hand, when the OLED cells 20 have defects such as spots, haze, and cracks in the automatic determination step performed by the controller 104, the automatic determination may be impossible.

If an error occurs in the automatic determination step as described above, the inspection image for the OLED cell 20, which can not be determined, may be transmitted to the inspection server (not shown) in step S120. In step S130, The naked eye of the OLED cell 20 which can not be judged can be judged manually by visual inspection of the image.

The visual inspection may be performed by a skilled worker, and it may be determined whether the image quality of the OLED cell 20 is within a predetermined range in the manual determination step. Also, although not shown, when the inspection image of the OLED cell 20 which can not be determined as described above is transmitted to the inspection server, the inspection server can generate an alarm signal so that the operator can immediately recognize the inspection image. For example, the alarm lamp may be turned on or an alarm sound may be generated.

Meanwhile, the operator can request the control unit 104 of the inspection apparatus 100 to determine the defect information of the OLED cell 20 which can not be determined, and the control unit 104 can detect defect information of the OLED cell, , Coordinates at which defects are detected, and the like to the inspection server.

According to an embodiment of the present invention, the inspection process for the substrate 10 can be continuously performed irrespective of the inspection image transmission step for the OLED cells 20 and the manual determination step by the operator, have. That is, the determination of the unidentifiable OLED cell 20 can be temporarily held, and the automatic determination of the next OLED cells 20 can continue.

As a result, since the inspection process for the OLED cells 20 can be continuously performed regardless of whether the OLED cell 20 is not judged, the operation of the inspection apparatus 100 may not be stopped. The operating rate of the inspection apparatus 100 can be greatly improved.

In step S140, the manual determination result may be transmitted to the testing apparatus 100. In step S150, the automatic determination result may be transmitted to the OLED cell 20, The manual determination result made by the operator can be integrated and transmitted to the process management server (not shown).

Meanwhile, the spectroscopic inspection of the OLED cells 20 may be performed while the automatic determination of the image quality of the OLED cells 20 is performed. For example, if the test signal is applied to one of the OLED cells 20 to turn on the OLED cell 20, the test image acquisition for the lit OLED cell 20 and the acquisition of the test image for the spectrometer 134 Spectroscopy can be done sequentially.

According to an embodiment of the present invention, after the automatic determination step for the OLED cells 20 is completed, the determination of the OLED cells 20 may be performed on the OLED cells 20, An alignment accuracy check can be performed.

Specifically, an inspection pattern (not shown) for checking the alignment accuracy between the thin film patterns constituting the OLED cells 20 may be provided on the substrate 10, And observing with a fluorescence microscope 136. In particular, the Pixel Position Accuracy (PPA) for each of the pixels constituting the OLED cells 20 can be checked in the alignment accuracy test. As an example, an enlarged image of the inspection pattern can be obtained by the fluorescence microscope, and the alignment accuracy check can be made automatically by comparing the enlarged image with a reference image. Meanwhile, the inspection pattern may be provided on the substrate 10 separately from the OLED cells 20, or alternatively, may be provided in the OLED cells 20, respectively.

According to an exemplary embodiment of the present invention, when the visual inspection by the operator is not performed even after both the image quality inspection and the spectral inspection and the alignment accuracy inspection are performed on the OLED cells 20 on the substrate 10, It is possible to temporarily store the substrate 10 in the buffer chamber connected to the substrate transfer chamber 202 of the inspection apparatus 100 and subsequently perform the inspection process for the subsequent substrate .

The temporary storage of the substrate 10 may be manually performed by the operator, and the automatic determination result and the manual determination result may be transmitted to the process control server 40 and then transferred to the subsequent sealing process facility 40.

On the other hand, in the case where the manual inspection is performed on a part of the OLED cells 20 due to defects generated on the substrate 10, in order to determine the distribution, frequency, and tendency of the defects, An image may be required. Although not shown, according to an embodiment of the present invention, merging the inspection images of the OLED cells 20 to produce a full image of the substrate 10, and transmitting the entire image to the inspection server More steps can be performed.

The entire image of the substrate 10 can be reviewed by the operator at the inspection server. Also, according to an embodiment of the present invention, the entire image of the substrate 10 may be transmitted to the process management server together with the automatic determination result and the manual determination result.

According to embodiments of the present invention as described above, manual inspection by a worker is performed on cells that can not be automatically judged while performing automatic inspection on display cells such as OLED cells 20 formed on the substrate 10 The inspection image can be transmitted to the inspection server so that it can be performed, and then the inspection process for subsequent cells can be successively performed.

In addition, even if the manual judgment by the operator is delayed, the substrate 10 on which the uncertain cell is generated can be temporarily stored in the buffer chamber and the inspection process for the subsequent substrate can be continuously performed.

As a result, the apparatus 100 for inspecting the display cells can be prevented from being stopped by the automatic judgment error, thereby greatly increasing the operation rate of the testing apparatus 100. [

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

10: substrate 20: OLED cell
22: test pad 100: test device
102: Inspection chamber 104:
110: substrate stage 120: probe card
122: card stage 130: optical inspection section
132: inspection camera 134: spectroscope
136: Fluorescence microscope 200: Substrate transport module
202: substrate transfer chamber 204: substrate transfer robot

Claims (13)

Obtaining inspection images for a plurality of display cells formed on a substrate using an inspection apparatus;
Automatically determining whether the display cells are charged based on the inspection images;
Transmitting an inspection image for a display cell which is not judged among the display cells to an inspection server;
Manually judging whether the display cell can not be judged by visual inspection of the inspection image transmitted to the inspection server;
Transmitting the manual determination result to the testing apparatus; And
And transmitting the automatic determination result and the manual determination result to the process management server. 2. The method of claim 1, wherein the automatic determination step and the manual determination step determine whether the image quality of the display cells is within a predetermined range. 2. The method of claim 1, wherein spectroscopic inspection of the display cells is performed during the automatic determination of the display cells. The method of claim 1, further comprising: generating an alert signal after transmitting the test image to an inspection server. 2. The method of claim 1, wherein after the automatic determination step is performed, an alignment accuracy check is performed between patterns constituting the display cells. 6. The method of claim 5, wherein the alignment accuracy check is performed by a fluorescence microscope. 2. The method of claim 1, wherein the steps are performed between a cell process to form the display cells on the substrate and an encapsulation process to encapsulate the display cells. The method of claim 1, wherein if the visual inspection is delayed, the substrate is temporarily stored in a buffer chamber of the inspection apparatus and an inspection process for a subsequent substrate is performed. 2. The method of claim 1, wherein the inspection images are acquired with an inspection signal applied to the inspection pads of the display cells using a probe card. 10. The display device of claim 9, wherein the display cells are arranged to have a plurality of rows and columns on the substrate, and the probes of the probe card are simultaneously in contact with the display cells in a row or column in the row direction or the column direction of the display cells Lt; RTI ID = 0.0 > 1, < / RTI > 11. The method of claim 10, wherein the test signals are sequentially applied to display cells contacted with probes of the probe card, and the test images are sequentially acquired according to application of the test signals. How to. 2. The method of claim 1, further comprising: merging inspection images for the display cells to produce a full image of the substrate; And
≪ / RTI > further comprising transmitting an entire image of the substrate to the inspection server. 13. The method of claim 12, wherein an entire image of the substrate is transmitted to the process management server together with the integrated automatic determination result and the manual determination result.

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