KR101217175B1

KR101217175B1 - Apparatus for inspecting substrate and method of inspecting substrate

Info

Publication number: KR101217175B1
Application number: KR1020100038573A
Authority: KR
Inventors: 최상진
Original assignee: 엘아이지에이디피 주식회사
Priority date: 2010-04-26
Filing date: 2010-04-26
Publication date: 2012-12-31
Also published as: KR20110119083A

Abstract

There is a need for an inspection method that is more reliable than spraying steam onto the substrate surface to inspect the substrate. The substrate inspection method according to the present invention for solving this problem, (a) irradiating light to the substrate inside the inspection chamber, (b) cooling the substrate so that water vapor condenses on the substrate surface and (c) Inspecting the defect of the substrate through the light reflected from the substrate where the water vapor has condensed.

Description

Substrate Inspection Device and Substrate Inspection Method {APPARATUS FOR INSPECTING SUBSTRATE AND METHOD OF INSPECTING SUBSTRATE}

The present invention relates to an apparatus for inspecting a workpiece and a method for inspecting a workpiece, and more particularly, to a substrate inspection apparatus and a substrate inspection method.

The liquid crystal display may be a combination of a CS (column space) layer, an RGB layer, a BM (Black Matrix) layer, a transparent electrode layer, a glass layer, and the like. For each layer (hereinafter, referred to as a substrate), a process of inspecting whether there are spots or flaws (for example, the state of the alignment layer or the flaw of the glass surface) may be performed.

One method of performing such inspection is to inject steam onto a substrate to observe conditions such as water droplet formation.

On the other hand, in the conventional substrate inspection method, the inspector visually inspects to detect the presence of stains or foreign substances on the substrate of the liquid crystal display device.

That is, it is directly visually determined whether a defect exists on the surface of the substrate through the light reflected by irradiating light onto the substrate.

However, according to this method, the set conditions of the inspection apparatus may be different for each inspector, and accordingly, a difference in inspection quality may occur.

In addition, there is a problem that the test takes a long time because it depends on the manual work of the inspector.

Because of these problems, the need for automation of inspection work that relies on manual labor is emerging.

There is a need for an inspection method that is more reliable than spraying steam onto the substrate surface to inspect the substrate.

In addition, there is a need for a substrate inspection apparatus and a substrate inspection method capable of a faster, more accurate and efficient automatic inspection.

Technical problems of the present invention are not limited to the above-mentioned technical problems, and other technical problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

Substrate inspection method according to the present invention for solving the above problems, (a) irradiating light to the substrate inside the inspection chamber; (b) cooling the substrate such that water vapor condenses on the substrate surface; And (c) inspecting the defect of the substrate through the light reflected from the substrate on which water vapor is condensed.

The method may further include supplying water vapor in the step (b) or before the step (b) to increase the water vapor pressure.

The method may further include increasing the internal temperature of the test chamber and supplying water vapor in step (b) or before step (b) to increase the water vapor pressure.

In addition, the step (b) may be characterized in that for cooling the first region which is a part of the substrate.

In addition, when water vapor condenses on the first region, the substrate may be moved to cool the second region, which is another part of the substrate.

In addition, the step (c), (c1) receiving the light reflected from the substrate condensed water vapor through a camera to obtain image information, (c2) based on the acquired image information of the substrate Checking for defects.

In addition, the step (c2) may include determining a region of the substrate having a non-condensing degree of water vapor as a defect of the substrate.

In addition, whether the degree of condensation of water vapor is uneven may include determining whether there is an area in which the brightness change is greater than or equal to a set value in the image information.

In addition, the method may further include heating the substrate to remove condensation.

A substrate inspection apparatus according to the present invention for solving the above problems, the light source for irradiating light to the substrate; A substrate cooling unit cooling the substrate such that water vapor condenses on the surface of the substrate; And a camera that receives the light reflected from the substrate.

The apparatus may further include a steam supply unit supplying steam to the substrate.

The apparatus may further include a defect determination unit that determines a defect of the substrate based on the image information obtained through the camera.

The apparatus may further include a controller for moving any one side of the substrate and the substrate cooling unit to change a region where water vapor is condensed.

The apparatus may further include a heater for heating the substrate to remove moisture condensed on the surface of the substrate.

In the case of forming a fine droplet layer by directly injecting steam onto the substrate surface, a non-uniform fine droplet layer is often formed in a region where the amount of injection is large. In addition, in the steam injection process, water droplets of different sizes may pop out to form a non-uniform water droplet layer. However, through the configuration of the present invention, there is an effect that can form a uniform fine droplet layer by causing a condensation phenomenon on the surface of the substrate without the process of spraying steam.

In addition, in the case of directly injecting steam, the configuration of the device is very complicated to apply to a large substrate, and when the device injecting steam is located on the upper surface of the substrate, particles are generated in the steam injector itself, thereby preventing substrate defects. There is a problem that can be caused. However, through the configuration of the present invention as the substrate cooling portion is located on the lower surface of the substrate there is an effect that the particle generation is suppressed, it is very easy to apply to inspection of large substrates.

In the case of a large-area substrate, there is an effect that the inspection can be performed by cooling some regions, performing inspections, and cooling the next region without having to cool the entire area.

The technical effects of the present invention are not limited to the above-mentioned effects, and other technical effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a schematic configuration diagram of a substrate inspection apparatus according to an embodiment of the present invention.
2 is a schematic block diagram of a substrate inspection apparatus according to an embodiment of the present invention.
3 is a temperature-vapor pressure graph showing the steam condensation result of the substrate inspection apparatus according to the embodiment of the present invention.
4 is a schematic structural diagram of a substrate inspection apparatus according to another embodiment of the present invention.
5 is a flowchart illustrating a method of inspecting a substrate according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present embodiment is not limited to the embodiments disclosed below, but can be implemented in various forms, and only this embodiment makes the disclosure of the present invention complete, and the scope of the invention to those skilled in the art. It is provided for complete information. Shapes of the elements in the drawings may be exaggerated parts for a more clear description, elements denoted by the same reference numerals in the drawings means the same element.

1 is a schematic configuration diagram of a substrate inspection apparatus according to an embodiment of the present invention.

2 is a schematic block diagram of a substrate inspection apparatus according to an embodiment of the present invention.

Figure 3 is a temperature-vapor pressure graph showing the steam condensation result of the substrate inspection apparatus according to an embodiment of the present invention.

As shown in FIG. 1 and FIG. 2, the substrate inspection apparatus according to the present embodiment includes an inspection chamber 101, a light source 110, a reflector 120, a camera 140, a substrate stage 131a, and substrate cooling. The unit 132a, the substrate heater 133a, the inspection chamber heater 150, the water vapor supply unit 160, the power supply unit 170, the storage unit 180, the display unit 190, and the controller 200 are included.

The inspection chamber 101 isolates the inside and the outside of the inspection chamber and prevents foreign substances such as dust from being introduced into the interior.

The light source 110 irradiates light onto the substrate. A metal halide lamp may be used for the light source 110, and other xenon lamps, mercury lamps, krypton lamps, halogen lamps, fluorescent lamps, etc. may be used, and lamps having optical characteristics similar to those of other metal halide lamps may be used. In addition, a sodium lamp or the like may be used, but other types of lamps capable of irradiating light similar to the optical characteristics of the sodium lamp may be used.

The reflector 120 is provided in the optical path of the light irradiated from the light source 110, and may reflect the light to guide the substrate S.

The camera 140 receives light reflected from the substrate and acquires image information of the substrate. The image information of the substrate may be an image photographing the substrate surface, a graphic computer file, graph information about image characteristics (brightness, change in brightness, color, etc.).

The substrate stage 131a may load and support the substrate S and may horizontally move, vertically move, and rotate the substrate stage 131a by the substrate stage control unit 204.

The substrate cooling unit 132a may include a refrigerant passage through which the refrigerant flows, thereby cooling the substrate S. As shown in FIG. The substrate may be cooled to a temperature such that water vapor may condense on the surface of the substrate at room temperature.

3, when the water vapor pressure is V1, if the temperature is lowered from T1 to T2 (path ①), water vapor may condense. The substrate cooling unit 132a may serve to cause a phenomenon of the path ① of FIG. 3.

Returning to FIG. 1, an evaporator (not shown) and a condenser (not shown) necessary for cooling the refrigerant may be separately provided outside the inspection chamber 101. The substrate stage 131a may move while the substrate cooling unit 132a is fixed at a predetermined position below the substrate stage 131a so as to change the region to be cooled.

In another embodiment, the substrate stage 131a may be fixed at a predetermined position and the substrate cooling unit 132a may move to change the region to be cooled.

In another embodiment, the substrate cooling unit may be inserted into the substrate stage so as to be slidable in the horizontal direction in the substrate plane to change the region to be cooled.

The substrate heater 133a may be installed at one side or both sides of the substrate cooling unit 132a to heat the substrate stage 131a and the substrate S to rapidly evaporate fine droplets condensed on the substrate surface.

The inspection chamber heater 150 may increase the internal temperature of the inspection chamber 101. Heat generated from the light source may also contribute to an increase in the internal temperature of the inspection chamber.

The water vapor supply unit 160 may increase the water vapor pressure by supplying water vapor into the inspection chamber 101.

By increasing the internal temperature of the inspection chamber 101, the saturated steam pressure can be increased. Accordingly, more water vapor may be supplied to the air inside the chamber through the water vapor supply unit 160.

For example, when rising from T2 to T1 in FIG. 3, the saturated steam pressure may rise from V1 to V3. In addition, assuming that the current water vapor pressure at V2 is V0, increasing the temperature to T1 may increase the water vapor pressure up to about V3.

When the actual water vapor pressure is V1 and the temperature is T1, the temperature must be lowered to T2 to cause condensation of water vapor (path ①). However, if the actual water vapor pressure is V2 and the temperature is T1, condensation of water vapor will occur even if the temperature is lowered to T3 only (path ②).

As a result, if the temperature inside the inspection chamber is high and the water vapor pressure is high, condensation of water vapor easily occurs even if the substrate is cooled slightly.

For example, if the current state is water vapor pressure V0 and the temperature is T3, increase the temperature to T1 (path ③), supply water vapor to V2 (path ④), and decrease the temperature to T3 (path ②). ) Condensation of water vapor occurs.

The storage unit 180 may store image information and other related data about the substrate.

The display 190 may provide the inspector with image information of the substrate and other related images or information.

The controller 200 is a part for controlling (position, angle, motion, etc.) each of the above-described components, and includes a light source controller 201, a camera controller 202, a reflector controller 203, and a substrate stage controller 204. And a defect determination unit 205 and a central control unit 206.

Each individual control unit may include a mechanical configuration of an actuator, a robotic arm, or the like, and a circuit portion for controlling the mechanical configuration.

The defect determining unit 205 determines whether there is a defect in the substrate through the acquired image information. The region where the degree of condensation of water vapor is uneven in the acquired image information may be determined as a defect in the substrate. Areas with surface defects or foreign matters have a large amount of condensation and may condense into larger droplets.

There may be various ways of determining whether the degree of condensation is non-uniform, and as an example, adjusting the brightness of the acquired image information, removing noise, and a section in which the degree of change in brightness exceeds a set value. May be determined as a defect.

The central control unit 206 controls the operation of each of the above components as a whole and performs the necessary calculations.

4 is a schematic structural diagram of a substrate inspection apparatus according to another embodiment of the present invention. For convenience of description, components substantially the same as those described above will be omitted.

As shown in FIG. 4, the substrate inspection apparatus according to the present embodiment includes an inspection chamber 101, a light source 110, a reflector 120, a camera 140, a substrate stage 131b, a substrate cooling unit 132b, The substrate heater 133b, the inspection chamber heater 150, and the steam supply unit 160 are included.

The substrate cooling unit 132b may be installed in the substrate stage 131b to cool the substrate. The substrate cooling unit 132b may be provided as a refrigerant passage installed in the substrate stage.

In another embodiment, the coolant flow path may be provided to include a plurality of unit flow paths so that the refrigerant flow paths can be divided into a plurality of areas. Accordingly, in the case where the cooling area of the substrate is to be changed, the unit channel may be separately controlled.

The substrate heater 133b may be installed in the substrate stage 131b and may heat the substrate to remove water droplets condensed on the substrate surface.

5 is a flowchart illustrating a method of inspecting a substrate according to an embodiment of the present invention. As an example, each step is listed in order, but may be implemented differently from the order described below unless the order of each step is explicitly defined in the claims.

As shown in FIG. 5, first, a step S10 of irradiating light onto a substrate may be performed.

In addition, the step of increasing the temperature of the test chamber and supplying the steam to increase the steam pressure (S20) may be performed.

In addition, the step S30 of cooling the first region of the substrate may be performed to condense water vapor on the surface of the substrate.

In addition, when water vapor condenses in the first region, a step (S40) of moving the substrate to cool the second region of the substrate may be performed. That is, in the case of a large-area substrate, the inspection may be performed by cooling some regions, performing inspections, and cooling the next region without cooling the entire area.

In addition, the step S50 of receiving the light reflected from the vapor condensed substrate through the camera to obtain image information may be performed. That is, the inspector may acquire image information through a camera instead of performing a visual inspection.

In addition, an operation (S60) of inspecting a defect of the substrate may be performed based on the acquired image information. That is, the inspector may inspect the defect through the image information obtained indirectly through the camera, instead of performing the visual inspection directly, or may inspect the defect automatically by computer processing for processing the image information.

Step S60 may include determining a region having a brightness change greater than or equal to a set value in the acquired image information as a defect.

Meanwhile, the method may further include heating the substrate to remove water vapor condensed on the substrate surface. That is, a step of quickly removing moisture on the surface of the substrate by using a heater may be performed so that the substrate inspection using the fine droplet layer may be quickly completed and then another kind of substrate inspection may be performed.

One embodiment of the invention described above and shown in the drawings should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art will be able to modify the technical idea of the present invention in various forms. Accordingly, such improvements and modifications will fall within the scope of the present invention as long as they are obvious to those skilled in the art.

Claims

(a) irradiating light onto the substrate inside the inspection chamber;
(b) cooling the substrate such that water vapor condenses on the substrate surface; And
(c) inspecting the defect of the substrate through the light reflected from the substrate where water vapor has condensed;
In the step (c), (c1) receiving light reflected from the substrate condensed with water vapor through a camera to obtain image information, and (c2) detecting defects in the substrate based on the acquired image information. Inspecting,
Wherein (c2) is a substrate inspection method comprising the step of determining the region of the condensation degree of the water vapor is a defect of the substrate.

The method of claim 1,
And supplying water vapor into the inspection chamber to increase the water vapor pressure.

The method of claim 1,
And increasing the internal temperature of the inspection chamber and supplying water vapor to increase the water vapor pressure.

The method of claim 1,
The step (b) is a substrate inspection method, characterized in that for cooling the first area which is a part of the substrate.

5. The method of claim 4,
And when the water vapor condenses on the first region, moving the substrate to cool the second region, which is another part of the substrate.

The method of claim 1,
The condensation degree of the water vapor is non-uniform whether the substrate inspection method comprising the step of determining whether there is a region of the brightness change is greater than a set value in the image information.

The method of claim 1,
And heating the substrate to remove condensed moisture.

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