KR20090078566A - Apparatus for edge defect of glass substrate and monitoring process - Google Patents

Abstract

An apparatus for inspecting edges of a glass substrate and an inspecting method thereof are provided to enhance efficiency of an inspection process by detecting correctly edge defects of the glass substrate or a panel. An apparatus for inspecting edges of a glass substrate includes a working table(111), a plurality of alignment inspecting cameras(124), a plurality of line scan cameras(125), and a transfer unit. A substrate(10) is loaded on the working table. The alignment inspecting cameras are used for photographing images of alignment marks(11) which are formed on the glass substrate. The line scan cameras are used for inspecting the edges of the glass substrate. The transfer unit controls a position of the working table.

Description

Apparatus for edge defect of glass substrate and monitoring process

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate edge inspection apparatus, and more particularly, to a substrate edge inspection apparatus and method capable of inspecting an edge state of a substrate more precisely by including an alignment inspection camera and a line scan camera.

A glass substrate is a screen which forms an image from a liquid crystal of a terminal, attached to a television (TV), a monitor of a computer, etc. Typical examples include cathode ray tube (CRT), projection, plasma display panel (PDP), liquid crystal display (LCD), and organic light emitting diode (OLED).

CRT (Cathode Ray Tube) refers to a cathode ray tube, also known as a brown tube, refers to a device for displaying an image by converting an electrical signal into an optical image by emitting an electron beam (beam) to a fluorescent surface. CRT is one of the most widely used in conventional televisions and monitors. It is cheaper than projection, LCD, and PDP, so it is economically less expensive, and it has better image quality than projection, PDP and LCD. However, for example, it is difficult to enjoy large screens because it is not easy to produce more than 34 inches.

Projection is classified into three types: CRT (Cathode Ray Tube) projection, LCD (Liquid Crystal Display) projection, and DLP (Digital Lighting Processing) projection.

CRT projection is the earliest projection method where a small CRT is placed below the screen to reflect it on the screen. Compared to other projection methods, the price is lower, but the picture quality is not good. It has the disadvantage of being thick, relatively large in volume, and having a narrow viewing angle. However, since it has been developed for a long time, it is said to be the safest in terms of stability.

LCD projection is a method of replacing CRT, which is a conventional driving method, with LCD. More than three times brighter and sharper than CRT projection. LCD projection has the overall smaller advantage over CRT projection, but the image quality is lower due to the lower contrast ratio. DLP projection has the best brightness and image quality among the projection types. By adopting a driving method that constructs the screen with reflections through numerous tiny mirrors, the screen is not only clean and delicate, but also the lightest and thinnest among the projections. However, due to its excellent image quality and small volume, it is the most economically burdensome. On the other hand, the three types of projections introduced above have a disadvantage in that the lamps need to be replaced periodically because all the images are blurred over time.

Plasma Display Panel (PDP) utilizes the phenomenon of plasma, which is a mixture of ions and electrons. Plasma refers to a state in which positive charges (ions) and negative charges (electrons) are mixed in almost the same amount and pretend to be close to free particles while maintaining electrical neutrality. Plasma emits strong and beautiful light like aurora as the internal gas is activated when the strong voltage is applied to the positive electrode and the negative electrode in the vacuum state and then returns to the stable original state as time passes.

The display using the image is called PDP. PDP is very thin, so it is also suitable for wall-mounting. It has the advantage that almost no afterimage remains even in the video system, and the color is excellent. However, there is a drawback that not only generates a lot of heat but also consumes relatively high power compared to other things.

LCD (Liquid Crystal Display) refers to a liquid crystal (Liquid Crystal) between the two glass substrates. Since LCDs are produced by semiconductor processes, they have advantages over PDPs in terms of resolution. For example, if you connect your computer to the PDP and then reduce the screen size, the text will be hard to read on the PDP, but this is less because the LCD has a higher resolution. However, LCD has a disadvantage of slow response speed. The response speed problem is that a liquid substance called a liquid crystal does not react in nanoseconds to polarize while changing direction by a current signal. In addition, LCDs are still economically expensive compared to PDPs.

Organic Light Emitting Diodes (OLEDs) are considered to be next-generation displays that will replace the aforementioned LCDs. Its high energy efficiency and bright brightness make it suitable for the display of small home appliances. OLED, also called organic EL, is made by emitting light by applying electric field with its own light emitting method. It boasts vivid color, light structure and fast response speed.

On the other hand, the size of the screen employed as a display device in the past was mostly about 14 to 30 degrees. In recent years, however, they prefer large screens of 40 or more for wider viewing. Therefore, the size of the glass substrate used is gradually increasing in size.

The glass substrate goes through a molding process of forming a glass substrate through raw materials, and is then released as a product in a state that satisfies basic specifications through a cutting process of cutting to a corresponding standard and a polishing process of polishing a corresponding part. Of course, in addition to the cutting and polishing process, it also involves an inspection process or a repair process if necessary.

Many defects can occur in the glass substrate due to various factors from the first molding of the glass substrate to the final product release. One of the defects is the so-called edge defect of the glass substrate, which occurs at the edge, which is the end face of the glass substrate. Edge defect means that the edges of glass substrates are not parallel and have a rugged state. Depending on the degree of edge defects, repair may be performed through a repair process. .

In the prior art, however, inspection of edge defects on glass substrates has been relied only on visual inspection of the inspector. This visual inspection requires a considerable amount of skill and experience of the inspector, and subject to the subjective measurement criteria of the inspector.

Another way to improve visual inspection is to use a sensor to inspect edge defects. However, the method by the sensor not only has to stop the glass substrate being transported in the process, but also cannot inspect the entire edge of the glass substrate and detects a minute defect. Thus, a technique for inspecting edge defects of a glass substrate using a camera without using a sensor is disclosed in Korean Patent Laid-Open No. 10-2004-0005103.

However, the disclosed technology also loads the glass substrate of the inspection object in a separate inspection table, and then inspects the corresponding position through the camera, thereby inevitably decreasing the inspection efficiency. In other words, as described above, the glass substrate in the process is stopped and the glass substrate being transferred is stopped for the edge defect inspection under the situation that the glass substrate is gradually enlarged and the process work is continuously performed in-line through automation. Transferring to the system for inspection is a factor that can drastically reduce the productivity of glass substrates.

The present invention devised to solve the problems of the prior art as described above is provided with an alignment inspection camera and a line scan camera, it is possible to determine the defect of the substrate by more precisely check the alignment inspection and the state of the substrate It is an object of the present invention to provide a substrate edge inspection apparatus and method.

The object of the present invention is a work table for loading a substrate; A plurality of alignment inspection cameras for photographing an image of an alignment mark formed on the substrate; A plurality of line scan cameras for inspecting an edge surface of the substrate; And a conveying means for controlling the position of the work table.

Another object of the present invention is to load a substrate on a work table; Obtaining an image of a plurality of alignment marks formed on the substrate using an alignment inspection camera; Calculating substrate information including a standard specification, a rotation angle, and coordinates of the substrate from the alignment mark image; Correcting the position of the substrate using the substrate information; Obtaining an edge image of the substrate using a line scan camera while moving the work table uniaxially; And determining whether the substrate is in a good or bad state by using the edge image.

Accordingly, the substrate edge inspection apparatus and method of the present invention have a remarkable and advantageous effect of more precisely inspecting edge defects of a substrate or panel using an alignment inspection camera and a line scan camera.

The terms or words used in this specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best describe their invention. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of an edge substrate edge inspection apparatus according to the present invention.

The substrate edge inspection apparatus 100 includes a loading unit 110 for loading a substrate 10 and a inspection unit 120 having a plurality of cameras for inspecting an alignment mark and an edge surface of the substrate 10. And a control unit 130 for controlling the loading unit 110 and the inspection unit 120.

The loading unit 110 according to the present invention includes a work table 111 for supporting a substrate, a clamp (not shown) for fixing the substrate, and a transfer member 112 for moving the plate 111 to an appropriate position. . The transfer member 112 includes a linear motor (not shown) and a rotating device (not shown) to move or rotate the loading unit 110 on which the substrate is loaded on the X, Y, and rotation axes. The linear motor is operated by power supplied from a power source (not shown).

The inspection unit 120 according to the present invention includes upper and lower illumination sources 122 and 123, a plurality of alignment inspection cameras 124, and a line scan camera 125.

Alignment inspection camera 124 according to the present invention after taking the image of the alignment mark 11 formed on the substrate, and transmits the alignment mark image to the computer. The line scan camera 125 is for monitoring the edge state of the substrate 10.

The alignment inspection camera 124 and the line scan camera 125 according to the present invention are formed in one unit.

The alignment inspection camera 124 and the line scan camera 125 formed integrally are provided at both sides of the substrate 10. Inside the substrate on which the alignment mark 11 is formed, the alignment inspection camera 124 is provided on the substrate 10. The line scan camera 125 is positioned outside of the substrate 10 on which the edge surface is formed by cutting.

The camera has illumination sources 122 and 123 to supply the illumination necessary for the alignment of the substrate 10 and the edge inspection of the substrate 10.

Information related to the position of the substrate 10 collected through the alignment inspection camera 124 and the line scan camera 125, the alignment state of the substrate 10, and the size of the substrate 10 may be transmitted to the computer through the interface 160. 170).

The transfer member 112 for adjusting the position of the substrate 10 according to the present invention is connected to the computer 170 via the PLC controller 160 and the interface 150.

 Hereinafter, a method of inspecting a substrate edge according to the present invention will be described with reference to FIG. 2.

The substrate 10 or panel on which the semiconductor process is performed is loaded on the work table 111 by a robot arm (not shown). The substrate loaded on the work table is fixed by a clamp (not shown) with vacuum adsorption. At the same time, the setting values of all the devices constituting the test apparatus are initialized (S210).

When the position of the substrate 10 loaded on the work table 111 is fixed, the work table 111 is moved by the operation of the transfer member 112 to move the substrate 10 to an appropriate position according to the input set value. To align (S220). To check the positional alignment of the substrate 10, the inspection unit 120 approaches the substrate 10. When light is irradiated from the illumination sources 122 and 123 positioned below or above the substrate 10 by the lighting control unit 140, the alignment inspection camera 124 provided in the inspection unit 120 is aligned to the substrate 10. The image of the mark 11 is photographed. Since the alignment marks 11 are formed in plural along the edge of the substrate, the transfer member 112 is operated to capture all the alignment marks 11. The alignment mark 11 image is transmitted to the computer 170 through the interface 150 (S230). The computer 170 reads the alignment mark image to calculate the size, rotation angle and coordinates of the substrate.

If the calculated value does not match the previously set value, for example, if the alignment of the substrate 100 is not good (S230), the computer 170 transmits a correction signal for correcting the position to the PLC controller 160. . The PLC controller 160 receiving the signal operates the transfer member 112 including the linear motor (not shown) and the rotating device (not shown) to realign the position of the substrate 10.

If there is damage to the alignment mark, the computer can judge the substrate as defective and terminate the inspection.

According to one embodiment of the invention, it is preferable that the alignment inspection camera 124 checks the alignment mark 11 of the substrate 10 in order to confirm the position of the rearranged substrate.

If the alignment is good, the line scan camera 125 for edge inspection of the substrate 10 is activated.

The line scan camera 125 may photograph a partial region where the edge of the substrate 10 and the pattern inside the substrate are formed. When AC power is supplied to the linear motor (not shown) constituting the conveying member 112, the work table 111 moves uniaxially, and the line scan camera 125 inspects the edge state of the substrate 10. (S250). At this time, the line scan camera 125 photographs the state (S261) of the edge of the substrate, the surface state (S262) near the edge and the state (S263) of the pattern, and sends the information to the computer (S250).

  The computer 170 checks the state of the edge surface, the surface, and the pattern of the substrate 10 based on the information input from the line scan camera 125. If everything is judged to be good (S270), by operating the conveying member to rotate the work table 111 by 90 degrees, the alignment inspection and the edge inspection carried out previously. When the inspection is completed, the substrate is moved to the next process by the robot arm.

If any one is determined to be defective (S280), the computer completes inspection of the substrate.

Although the present invention has been shown and described with reference to the preferred embodiments as described above, it is not limited to the above embodiments and those skilled in the art without departing from the spirit of the present invention. Various changes and modifications will be possible.

1 is a substrate edge inspection apparatus according to the present invention,

2 is a flow chart of a substrate edge inspection method according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: Substrate 11: Alignment Mark

110: loading unit 111: work table

120: inspection unit 122,123: lighting source

124: alignment inspection camera 125: line scan camera

130: control unit 140: lighting control unit

150: interface 160: PLC control unit

170: computer

Claims (7)

A work table for loading a substrate; A plurality of alignment inspection cameras for photographing an image of an alignment mark formed on the substrate; A plurality of line scan cameras for inspecting an edge surface of the substrate; And Transfer means for controlling the position of the work table Substrate edge inspection device comprising a. The method of claim 1, And a computer for outputting a correction signal for correcting the position of the substrate by reading the information of the alignment mark image photographed by the alignment inspection camera. The method of claim 1, And a PLC controller for sending a signal to the transfer means to receive the correction signal and adjust the position of the substrate. The method of claim 1, Located at the top / bottom of the substrate to irradiate light to the substrate edge inspection apparatus including a top / bottom illumination source for detecting it. Loading the substrate onto a work table; Obtaining an image of a plurality of alignment marks formed on the substrate using an alignment inspection camera; Calculating substrate information including any one of a standard specification, a rotation angle, and coordinates of the substrate from the alignment mark image; Correcting the position of the substrate using the substrate information; Obtaining an edge image of the substrate using a line scan camera while moving the work table uniaxially; And Determining whether the substrate is in good or bad condition using the edge image. Inspection method of the substrate edge comprising a. The method of claim 5, Checking the surface and pattern state of the substrate using the line scan camera. The method of claim 5, wherein the calculating of the substrate information including the standard specification, the rotation angle and the coordinates of the substrate from the alignment mark image, If the alignment mark is damaged, ending the inspection of the substrate.

Images