JP3863976B2 - Board inspection equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate inspection apparatus used for defect inspection of, for example, a glass substrate of a liquid crystal display (LCD).
[0002]
[Prior art]
Conventionally, defect inspection of a substrate to be inspected, such as a glass substrate used in an LCD, is a macro observation in which illumination light is applied to the surface of the inspected substrate and a defect portion such as a scratch on the substrate surface is observed from an optical change of the reflected light. In some cases, micro-observation is switched by magnifying and observing a defect portion detected by macro observation.
[0003]
Conventionally, a metal halide lamp composed of a point light source is used as a light source for macro observation, and the surface of the substrate to be inspected is irradiated with the light from the metal halide lamp through a Fresnel lens as convergent light. The inspector visually finds the optical change of the reflected light at the substrate to observe the defect on the substrate surface.
[0004]
[Problems to be solved by the invention]
However, according to such a macro observation light source using a metal halide lamp, it is possible to detect scratches and dirt on the surface of the inspected substrate that can be detected from the optical change of the reflected light on the surface of the inspected substrate. Since the film unevenness on the substrate to be inspected cannot be detected, there is a problem that the macro observation is not perfect and the defect inspection cannot be performed with high accuracy.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a substrate inspection apparatus capable of performing macro observation with high accuracy on a substrate to be inspected.
[0005]
[Means for Solving the Problems]
The substrate inspection apparatus of the present invention includes a macro observation illumination light source including a point light source provided above the apparatus main body and a line light source that emits a specific wavelength at which interference occurs due to the film of the substrate to be inspected. An inspection substrate holding portion that holds the substrate to be inspected, and a rotational drive that rotates in the front-rear direction to tilt or swing the inspection substrate holding portion. And a Fresnel lens that is provided in an illumination optical path between the macro observation light source and the inspected substrate holder, and converts illumination light from the point light source and the line light source into convergent light, and the macro observation light source and the provided illumination optical path between the inspection substrate holder, is converted to the scattering state to scatter the illuminating light from the linear light source that has passed through the Fresnel lens by the Fresnel lens Characterized by comprising a liquid crystal filter capable electrically switched to the transmission state for transmitting the converged light from the point light source.
[0007]
According to the present invention, convergent light from a point light source and scattered light from a line light source that emits light of a specific wavelength can be selectively applied to the surface of the substrate to be inspected by switching the liquid crystal filter. Thus, scratches and dirt on the surface of the substrate to be inspected can be detected, and film unevenness of the substrate to be inspected can also be detected by scattered light from the line light source.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 and 2 show a schematic configuration of a substrate inspection apparatus to which an embodiment of the present invention is applied. In the figure, reference numeral 1 denotes an apparatus main body, and a holder 2 is disposed in the apparatus main body 1 as a substrate to be inspected. The holder 2 is used to place and hold a large substrate to be inspected such as a glass substrate used in an LCD.
[0010]
The holder 2 is rotatably supported at the front ends of the pair of arms 3 at both side surface intermediate portions. These arms 3 are arranged in the vertical direction as shown in FIG. 3, and their base end portions are individually connected to the movable portions 401 of the pair of ball screws 4 with guides so as to be rotatable.
[0011]
These guide-equipped ball screws 4 move the movable portion 401 in the vertical direction along the guide by the rotation of a ball screw (not shown). A vertical driving force is applied to the holder 2 via the arm 3 by the movement of the movable portion 401. I try to let them. Further, as shown in FIG. 4, these guided ball screws 4 are provided with pulleys 5, 5, respectively, and a belt 6 is bridged between the pulleys 5, 5, and the pulley 5 of one guided ball screw 4. As shown in FIG. 3, the pulley 501 directly connected to the shaft is connected to the rotating shaft of the motor 8 via the belt 7, and the ball screws with guides are connected via the belts 7 and 6 and the pulleys 501 and 5 by the rotation of the motor 8. The four ball screws are simultaneously rotated so that the vertical driving forces acting on the intermediate portions on both sides of the holder 2 are equal to each other.
[0012]
In FIG. 4, reference numeral 9 denotes a relay pulley for adjusting the tension of the belt 6 between the pulleys 5 and 5.
A pair of guided ball screws 4 that support the holder 2 via the arm 3 are provided on the common base 10. As shown in FIGS. 4 and 5, the base 10 is provided so as to be movable via a guide 11 with respect to a pair of rails 102 provided in parallel to the fixing portion 101 on the apparatus main body 1 side at a predetermined interval. ing. In addition, an air cylinder 12 is provided between the pair of rails 102 of the fixing portion 101 on the apparatus main body 1 side, and the base 10 is moved along the pair of rails 102 by the air cylinder 12. That is, the pair of ball screws 4 with guides provided on the common base 10 support the holder 2 via the arm 3, in front (left side in the figure) and rear (right side in the figure) of the apparatus body 1 shown in FIG. It can be reciprocated within a predetermined range in each direction.
[0013]
On the other hand, the holder 2 is provided with front fulcrum receiving portions 13 on both sides of the end corresponding to the front of the apparatus main body 1 among both ends sandwiching the support portion by the arm 3 as shown in FIG. 1 A rear fulcrum receiving portion 14 is provided on both sides of the end corresponding to the rear. Furthermore, a fulcrum part 15 corresponding to the front fulcrum receiving part 13 and a fulcrum part 16 corresponding to the rear fulcrum receiving part 14 are provided on the base 10. In this case, the fulcrum part 15 corresponding to the front fulcrum receiving part 13 is provided at a position slightly higher than the fulcrum part 16 corresponding to the rear fulcrum receiving part 14.
[0014]
Here, the front fulcrum receiving portion 13 provided in the holder 2 rotatably accommodates the receiving portion main body 133 via a bearing 132 in the hollow portion of the cylindrical receiving portion case 131 as shown in FIG. ing. The receiving portion main body 133 has a receiving hole portion 134 in the front, and is inserted through the shaft 135 so as to be movable in the axial direction. When a fulcrum shaft 151 of a fulcrum portion 15 described later is inserted into the receiving hole portion 134. In this state, the fulcrum shaft 151 is rotatably supported and the shaft 135 is pushed in so that the sensor 136 detects the insertion state of the fulcrum shaft 151. On the other hand, as shown in FIGS. 6A and 6B, the fulcrum part 15 is provided with a movable part 152 having a fulcrum shaft 151 movably along the guide 153. The movable part 152 is provided with a movable shaft 155 of the air cylinder 154. , The fulcrum shaft 151 is moved by the air cylinder 154 via the movable part 152 so as to be able to advance and retreat, and can be inserted into and removed from the receiving hole part 134 of the fulcrum receiving part 13. Here, FIG. 6A shows a state in which the fulcrum shaft 151 of the fulcrum part 15 has retreated and has come out of the receiving hole part 134 of the fulcrum receiving part 13, and FIG. 7 shows that the fulcrum shaft 151 of the fulcrum part 15 has advanced. The state inserted in the receiving hole part 134 of the fulcrum receiving part 13 is shown.
[0015]
The rear fulcrum receiving part 14 and the fulcrum part 16 are also configured in the same manner as the front fulcrum receiving part 13 and the fulcrum part 15 described above, and are not described here.
[0016]
A metal highland lamp 17 and a sodium lamp 18 used as illumination for macro observation of the surface of the substrate to be inspected are provided above the apparatus main body 1.
In this case, the metal highland lamp 17 is composed of a point light source, and is mainly for obtaining convergent light by the Fresnel lens 20. The sodium lamp 18 is a linear light source and is used to obtain scattered light by scattering light having a specific wavelength of about 589 nm, which is likely to cause interference, with the liquid crystal filter 21. Further, since it is desirable to use the sodium lamp 18 in a state in which the sodium lamp 18 is always lit in terms of stability and durability, it is possible to switch light irradiation and cutoff using a shutter (not shown).
[0017]
A reflection mirror 19 is arranged to face the metal halide lamp 17 and the sodium lamp 18. The mirror 19 is provided with an inclination of 45 ° so as to reflect light from the metal halide lamp 17 and the sodium lamp 18 and enter the Fresnel lens 20. The Fresnel lens 20 is provided with a liquid crystal filter 21.
[0018]
The liquid crystal filter 21 can obtain a shutter operation for switching between a transparent state and a scattering state of light, is always opaque, and is switched to transparent when the power is turned on. In the opaque state, the light from the sodium lamp 18 Is scattered to irradiate the holder 2 at the time of macro observation as a surface light source, and in a transparent state, the light from the metal halide lamp 17 is transmitted through the Fresnel lens 20 so that the convergent light is observed at the time of macro observation. The holder 2 is irradiated.
[0019]
A backlight 22 incorporating a fluorescent lamp is provided behind the apparatus body 1. The backlight 22 is used for micro observation illumination, and an ND filter 23 for preventing reflection of external light is provided on the surface of the backlight 22.
[0020]
Further, a light source 24 composed of a fluorescent lamp or the like used as macro observation illumination on the back surface of the substrate to be inspected is provided in the lower front portion of the apparatus main body 1.
In front of the apparatus main body 1 shown in FIG. 1, guide rails (not shown) are provided along both side edges of the front surface of the apparatus main body 1, and an observation unit support portion 25 is disposed so as to cross the front surface of the apparatus main body 1 left and right. The observation unit support 25 is provided so that the front surface of the apparatus body 1 can be moved along the guide rail in the Y-axis direction in the figure, that is, in the vertical direction of the surface of the substrate to be inspected on the holder 2 raised in front of the apparatus body 1. Yes.
[0021]
The observation unit support unit 25 supports the stereomicroscope 26 so as to be movable. In this case, the stereomicroscope 26 can move along the observation unit support portion 25 in the X-axis direction shown in the drawing orthogonal to the movement direction of the observation unit support portion 25 on the front surface of the apparatus main body 1, that is, in the left-right direction on the inspected substrate surface. Thus, the entire surface of the substrate to be inspected on the holder 2 can be micro-observed.
[0022]
Further, an X scale 271 and a Y scale 272 are provided on the respective side edges in the X direction and the Y direction in front of the apparatus main body 1. These X scale 271 and Y scale 272 are for detecting the position coordinates of the stereomicroscope 26. In this case, the position coordinates of the stereomicroscope 26 are made to correspond to the substrate surface to be inspected of the holder 2, so The position coordinate data of the stereomicroscope 26 on the inspection board can be collected.
[0023]
Next, the operation of the embodiment configured as described above will be described.
First, when performing macro observation of the surface of the substrate to be inspected, a state in which the substrate to be inspected is placed on the holder 2 and the front fulcrum receiving portion 13 of the holder 2 is supported by the fulcrum portion 15 as shown in FIG. Then, the arm 3 is moved downward by the ball screw 4 with guide. In this case, as shown in FIG. 7, the fulcrum part 15 advances the fulcrum shaft 151 through the movable part 152 by the air cylinder 154 and inserts the fulcrum shaft 151 into the receiving hole part 134 of the fulcrum receiving part 13.
[0024]
In this state, the holder 2 is held horizontally or at a predetermined angle, preferably 30 to 45 °. Next, when the metal halide lamp 17 is turned on and the liquid crystal filter 21 is turned on at the same time to switch to the transparent state, the light from the metal halide lamp 17 is reflected by the reflection mirror 19 and converges to the convergence point F through the Fresnel lens 20. As a light to be irradiated, the surface of the substrate to be inspected on the holder 2 is irradiated. As a result, macro observation for inspecting defects such as scratches and dirt on the surface of the substrate to be inspected is performed by searching for an optically changed portion of the reflected light on the surface of the substrate to be inspected by the inspector.
[0025]
Next, instead of the metal halide lamp 17, a shutter (not shown) of the sodium lamp 18 is opened to emit light from the sodium lamp 18, and the liquid crystal filter 21 is turned off to switch to the opaque state (scattering state). Then, this time, the light from the sodium lamp 18 is scattered by the opaque liquid crystal filter 21 and irradiated onto the holder 2 during macro observation as a surface light source. Also in this case, the inspector visually observes the surface of the substrate to be inspected, but the sodium lamp 18 here generates light of a specific wavelength that is likely to cause interference. It is possible to detect defects such as film unevenness on the substrate to be inspected. In this backside macro observation, the arm 3 can be moved upward to tilt the holder 2 at a predetermined angle, or the arm 3 can be moved up and down to swing the holder 2.
[0026]
Next, when performing macro observation of the back surface of the substrate to be inspected, the arm 3 is slightly moved downward by the ball screw 4 with guide. Then, since the holder 2 supports the front fulcrum receiving part 13 by the fulcrum part 15, the holder 2 rotates slightly counterclockwise around the fulcrum part 15, and the rear fulcrum receiving part 14 faces the fulcrum part 16. Is located. Then, from this state, the rear fulcrum receiving part 14 is supported by the fulcrum part 16 in accordance with the operation shown in FIG. In addition, after the sensor (corresponding to the sensor 136 shown in FIG. 7) detects that the rear fulcrum receiving part 14 is supported by the fulcrum part 16, the support by the fulcrum part 15 of the front fulcrum receiving part 13 is released. To do. In this case, as shown in FIG. 6A, the fulcrum shaft 151 is retracted by the air cylinder 154 via the movable portion 152, and the fulcrum shaft 151 is extracted from the receiving hole portion 134 of the fulcrum receiving portion 13.
[0027]
Next, the arm 3 is moved upward by the ball screw 4 with guide. In this case, as shown in FIG. 3 and FIG. 4, the ball screw of each guided ball screw 4 is simultaneously rotated through the belts 7 and 6 and the pulleys 501 and 5 by the rotation of the motor 8, An upward driving force equal to is applied. Then, the holder 2 rotates clockwise around the fulcrum portion 16 and is raised to the position shown in (2A) of FIG.
[0028]
Next, as shown in FIG. 5, the air cylinder 12 is urged to move the common base 10 provided with the guided ball screw 4 to the front of the apparatus main body 1 along the rail 102. At this time, the arm 3 is also rotated around the support portion of the movable portion 401 of the ball screw 4 with guide. Thereby, the holder 2 is moved to the front position of the apparatus main body 1 shown in (2B) of FIG. Thereafter, when the light source 24 at the lower front of the apparatus main body 1 is turned on, the light from the light source 24 is irradiated on the back surface of the substrate to be inspected on the holder 2. Macro observations are performed to inspect defects such as dirt and dirt.
[0029]
Next, in order to perform micro observation of the surface of the substrate to be inspected, the guided ball screw 4 can be used from the macro observation state of the surface of the substrate to be inspected in which the front fulcrum receiving portion 13 of the holder 2 shown in FIG. To move the arm 3 upward. In this case, as shown in FIG. 3 and FIG. 4, the ball screw of each guided ball screw 4 is simultaneously rotated through the belts 7 and 6 and the pulleys 501 and 5 by the rotation of the motor 8, An upward driving force equal to is applied. Then, the holder 2 is rotated counterclockwise around the fulcrum 15 and is raised to the front position of the apparatus main body 1 shown in (2F) in the order of (2C), (2D), and (2E) in FIG. It is done.
[0030]
From this state, when the backlight 22 behind the apparatus main body 1 is turned on, the light of the backlight 22 is irradiated from the back of the substrate to be inspected on the holder 2. In this state, the inspector performs micro observation for inspecting defects such as scratches on the surface of the substrate to be inspected using the stereomicroscope 26.
[0031]
In this case, by moving the observation unit support 25 in the Y direction while moving the stereomicroscope 26 in the X direction along the observation unit support 25, the stereomicroscope 26 can be scanned over the entire surface of the inspected substrate. Then, micro observation is performed. In addition, when a microscopic observation finds a scratch or the like on the surface of the substrate to be inspected by the stereomicroscope 26, when a confirmation operation is performed, the position coordinates of the stereomicroscope 26 on the substrate to be inspected at this time are the X scale 271, It is detected by the Y scale 272 and can be collected as position coordinate data.
[0032]
Accordingly, in this manner, the front fulcrum receiving portion 13 of the holder 2 is supported by the fulcrum portion 15 and the holder 2 is positioned downward by the ball screw 4 with guide, and the holder 2 is held horizontally. In the transparent state 21, the light from the metal halide lamp 17 is irradiated as convergent light onto the surface of the substrate to be inspected on the holder 2 through the Fresnel lens 20, and in the scattering state (opaque operation) of the liquid crystal filter 21, the sodium lamp Since the light from 18 can be scattered and irradiated onto the surface of the substrate to be inspected on the holder 2 as a surface light source, the substrate to be inspected by the converged light of the metal halide lamp 17 by switching between the transparent state and the scattering state of the liquid crystal filter 21. It can detect scratches and dirt on the surface, and also detects film irregularities on the substrate to be inspected by the scattered light of the sodium lamp 18. It can, with respect to the substrate to be inspected can be performed with high accuracy macro observation.
[0033]
Further, by using scattered light from the sodium lamp 18 that generates light of a specific wavelength that is likely to cause interference, it is possible to effectively detect film unevenness on the surface of the substrate to be inspected.
[0034]
【The invention's effect】
As described above, according to the present invention, convergent light from a point light source and scattered light from a line light source that emits light of a specific wavelength are selectively applied to the surface of the substrate to be inspected by switching between the liquid crystal filter and the illumination switching means. Therefore, it is possible to detect scratches and dirt on the surface of the substrate to be inspected with the convergent light from the point light source , and to detect film irregularities on the substrate to be inspected with the scattered light from the line light source. It can be performed. Further, by using a linear light source that emits a specific wavelength at which interference easily occurs, it is possible to effectively detect film unevenness of the substrate to be inspected.
[Brief description of the drawings]
FIG. 1 is a front view showing a schematic configuration of an embodiment of the present invention.
FIG. 2 is a side view showing a schematic configuration of an embodiment.
FIG. 3 is a diagram showing a schematic configuration of a drive unit in a vertical direction of a holder used in one embodiment.
FIG. 4 is a diagram showing a schematic configuration of a drive unit of a ball screw with guide used in one embodiment.
FIG. 5 is a diagram showing a schematic configuration of a base provided with a ball screw with guide used in one embodiment.
FIG. 6 is a diagram showing a schematic configuration of a fulcrum receiving part and a fulcrum part used in one embodiment.
FIG. 7 is a diagram showing a schematic configuration of a fulcrum receiving part and a fulcrum part used in one embodiment.
[Explanation of symbols]
1 ... the device body,
2 ... Holder,
3 ... arm,
4 ... Ball screw with guide,
401 ... movable part,
5, 501 ... pulley,
6, 7 ... belt,
8 ... motor,
9 ... Relay pulley,
10 ... Base,
101 ... Fixing part,
102 ... Rail,
103 ... fixed part,
11 ... Guide,
12 ... Air cylinder,
13 ... Front fulcrum receiving part,
131 ... receiving part case,
132 ... bearings,
133 ... the receiving body,
134 ... receiving hole part,
135 ... axis,
14: Rear fulcrum receiving part,
15, 16 ... fulcrum part,
151 ... fulcrum shaft,
152 ... movable part,
153 ... Guide,
154 ... Air cylinder,
155 ... movable shaft,
17 ... Metal halide lamp,
18 ... Sodium lamp,
19 ... Mirror,
20 ... Fresnel lens,
21 ... Liquid crystal filter,
22 ... Backlight,
23 ... ND filter,
24. Light source,
25 ... Observation unit support,
26 ... Stereo microscope,
271, 272 ... Scale.

Claims (4)

An illumination light source for macro observation comprising a point light source provided above the apparatus main body and a line light source that emits a specific wavelength at which interference occurs due to the film of the substrate to be inspected;
An inspection substrate holding unit that is provided below the macro observation illumination light source in the apparatus body and holds the inspection substrate;
A rotation drive unit that rotates in the front-rear direction to tilt or swing the inspected substrate holding unit;
A Fresnel lens that is provided in an illumination optical path between the macro observation light source and the inspected substrate holder, and converts illumination light from the point light source and the line light source into convergent light;
The scattering state is provided in an illumination optical path between the macro observation light source and the inspected substrate holding unit, and scatters the illumination light from the line light source that has passed through the Fresnel lens, and converted by the Fresnel lens. A liquid crystal filter that can be electrically switched to a transmissive state that transmits convergent light from a point light source ;
A substrate inspection apparatus comprising: A reflection mirror that directs illumination light emitted from the point light source and the line light source toward the inspected substrate holder is disposed above the Fresnel lens, and the line is outside the illumination light path of the point light source reflected by the reflection mirror. The substrate inspection apparatus according to claim 1, wherein a light source is disposed . The line light source includes a sodium lamp that emits a specific wavelength that causes interference due to a film of the substrate to be inspected, and has a shutter that blocks irradiation light to the substrate to be inspected in a lighting state. The substrate inspection apparatus according to claim 1 or 2. Macro observation for illuminating the back surface of the inspected substrate with the inspected substrate holding portion set up so as to be movable to the front position of the apparatus main body, and the inspected substrate holding portion being moved to the front position The substrate inspection apparatus according to claim 1 , wherein a light source is provided at a lower front portion of the apparatus main body.

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