JP2008187156A - Substrate detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass substrate detection device that detects the presence or non-presence of the glass substrate on a sample stage not only at any time but also irrespective of the quality or thickness of the glass substrate in addition to a light volume incident to a sensor. <P>SOLUTION: This invention relates to a substrate detection device wherein detection is carried out in such a manner that a light emitting position and a light receiving position are rectilinearily arranged by using a high rectilinearity transmitting sensor such as a laser beam sensor and by focusing on the light reflective index. In the foregoing method, the device is turned on (ON) since the light receiving volume is great when light is not blocked by the shielding materials, and turned off (OFF) since the light receiving volume is small when the light is blocked by them. More specifically, the light receiving volume is reduced since the glass reflective index light distribution path is displaced in such a shielding material whose material quality is transmissive like glass. Therefore, the device detects the presence or non-presence of the shielding materials based on the reduced light receiving volume, and is turned off (OFF) if it is found that they are present. Further, the device enables substrate detection since the light receiving volume is not reduced if the displacement of the shielding position is not so great as expected and if in the light path. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a glass substrate detection device that detects the presence or absence of a glass substrate in devices that handle glass substrates.

A method for detecting the presence or absence of a conventional glass substrate will be described below.
FIG. 3 is a diagram showing a conventional glass substrate transfer robot and a sample stage on which the glass substrate transferred by the transfer robot is placed. The sample stage in FIG. 3 is provided, for example, in a dimension measurement apparatus that measures the line width, line interval, and the like of a pattern fixed on the sample stage and formed on a glass substrate.

  Reference numeral 1 denotes a glass substrate which is an object to be inspected, 2 a substrate cram table (sample table) on which the glass substrate 1 is placed and fixed, and 3 a relative movement of the measurement point of the glass substrate 1 in the X-axis direction. X-axis moving stage 4 is a Y-axis moving stage for relatively moving the measurement point area of the glass substrate 1 in the Y-axis direction, 5 is an anti-vibration table for the substrate clamp table 2, 6 is an illumination power source, and 7 is An XY movement control unit for controlling the movement of the X-axis movement stage 3 and the Y-axis movement stage 4, 8 is an optical microscope, 9 is a light guide for inputting the output light of the illumination power source 6 as epi-illumination of the optical microscope 8, and 11 is an optical Inspection objective lens of the microscope 8, 10 is a revolver for switching the inspection objective lens 11 of the optical microscope 8 to a desired magnification, 12 is a reflection sensor, 13 is an optical axis (Z-axis) moving stage, and 14 is an enlargement of the optical microscope 8. Gala A camera that captures a reflected light image of a measurement point area on the substrate 1 and outputs it as a video signal, 15 controls the entire measuring apparatus to measure the line width, and calculates the line width and the like from the video signal output from the measurement camera 14 A measurement control unit for measuring dimensions, 16 is a monitor for displaying display information given from the measurement control unit 15, 17 is a transfer arm, 18 is linked to the transfer arm 17, and is used to load the glass substrate 1 and transfer it to the substrate clamp table. It is a substrate transfer hand. The camera 14 is, for example, a CCD (Charge Coupled Device) camera.

  The glass substrate 1 to be transferred is transferred from the substrate transfer hand 18 to the substrate clamp table 2 by the transfer arm 17. The conveyed glass substrate 1 is subjected to predetermined processing by a dimension measuring device. In order for the dimension measuring apparatus to start predetermined processing, it must first be recognized that the glass substrate has been transported and placed at a predetermined position on the substrate clamp table 2.

A method of carrying and placing (fixing) will be described with reference to FIGS. FIG. 4 is a diagram for explaining a conventional substrate clamping method. FIG. 5 is a diagram for explaining a conventional substrate transfer method.
In FIG. 5, after the Y-axis moving stage 4 and the X-axis moving stage 3 are moved to the substrate receiving preparation position, the substrate receiving pins 191, 192, Each of 193 and 194 is raised, and the glass substrate 1 on the substrate transport hand 18 is lifted upward.
Thereafter, the substrate transport hand 18 moves parallel to the left side and retracts.

  The substrate receiving pins 191, 192, 193, and 194 are lowered to deliver the glass substrate 1 to the substrate clamp table 2. The substrate plane maintaining pins 2001, 2002,..., 2099, 2100 are attached to the substrate clamp table 2 and maintain the flatness of the entire substrate.

Next, in FIG. 4, the substrate reference surfaces 101 and 102 (indicated by bold lines) of the glass substrate 1 are pressed against the reference rollers 201, 202, and 211 to fix the glass substrate 1. That is, the glass substrate 1 is pushed by the pressing rollers 203, 204, 212 in the direction of an arrow (an arrow drawn next to the pressing rollers 203, 204, 212) (for example, the pressing force is 2N), and the reference roller Press against 201, 202, 211. The reference rollers 201, 202, and 211 can hold a force (for example, 5N) that does not lose the force of the pressing rollers 203, 204, and 212. In this state, the back surface of the glass substrate 1 shown in FIG. 5 is sucked and held by suction pads 2201 to 2212 (indicated by black circles in FIG. 5) provided on the substrate clamp table 2.
After the substrate is attracted, the pressing rollers 203, 204, and 212 are retracted to the outside by releasing the substrate pressing. The reference rollers 201, 202, 211 are also retracted to the outside.

  Thus, in an inspection apparatus such as an automatic line width measuring apparatus, for example, center position coordinates 1121 to 1128 of a measurement point area to be measured are registered in advance with reference to the substrate reference planes 101 and 102 shown in FIG. Then, when measuring the glass substrate 1 which is an object to be inspected, the data is read, and the line width of the wiring pattern at the position is measured.

  As shown in FIG. 3, the glass substrate 1 of the object to be inspected is back-surface sucked and fixed by suction pads 2201 to 2212 attached to the substrate clamp table 2 after the presence or absence of the substrate is confirmed by the reflection sensor 12. The The substrate clamp table 2 is below the Y-axis moving stage 4 and the X-axis moving stage 3 disposed on the vibration isolation table 5, and can move the optical microscope 8 in a plane (in the X-axis direction and the Y-axis direction). An arbitrary position (measurement point area) in the substrate 2 is observed with the optical microscope 8.

  FIG. 2 is a partial cross-sectional view of FIG. 3 for explaining the reflection sensor 12 in more detail. As shown in FIG. 2, the reflection sensor 12 outputs light from the sensor light emitting unit 121, reflects on the back side of the glass substrate 1, and enters the sensor light receiving unit 122. At this time, when the material of the glass substrate 1 is bare glass, only about 4% of the output light from the sensor light emitting unit 121 enters the light receiving unit 122. The sensor sensitivity of the light receiving unit 122 can be adjusted. However, if the sensor sensitivity is increased in order to compensate for the small amount of received light, the tolerance for noise is reduced.

The illumination power supply 6 introduces the output light into the optical microscope 8 by the light guide 9. The introduced light is applied to the inspection object 1 through the inspection objective lens 11. The irradiated light is reflected and reflected by the glass substrate surface in the measurement point area, and the reflected light passes through the inspection objective lens 11 and is captured by the camera 14 via the intermediate lens.
A zooming mechanism (revolver) 10 switches the inspection objective lens 11 according to the purpose, and changes the magnification of the optical microscope 8.

  The optical axis (Z-axis) moving stage 13 moves the entire optical microscope 8 equipped with the inspection objective lens 11 in the optical axis (Z-axis) direction in order to maintain the focal length of the inspection objective lens 11.

The above-described substrate positioning method is described in Patent Document 1, for example.
JP 2004-186681 A

  In the above-described prior art, whether the substrate receiving pins 191, 192, 193, and 194 have received the glass substrate 1 is determined by lowering and placing on the sample stage, and then checking the presence or absence of the substrate with the reflection sensor 12. Since it is not known when the hand 18 is put on, there is a drawback that the judgment is delayed.

The reflection sensor outputs light from the sensor light emitting unit, reflects on the back side of the glass substrate, and enters the sensor light receiving unit. At this time, when the material of the glass substrate is bare glass, only a part of the output light from the sensor light emitting part enters the light receiving part. Although it is possible to adjust the sensor sensitivity of the light receiving section, there is a drawback that the tolerance for noise is lowered.
In addition, the position of the glass substrate needs to exactly match the surface position of the substrate clamp table.
The object of the present invention is to solve the above-mentioned problems and to detect the presence or absence of the glass substrate on the sample stage at any point in time, regardless of the material and thickness of the glass substrate or to the amount of light incident on the sensor. It is an object of the present invention to provide a glass substrate detection device capable of detecting the presence or absence of a substrate.

In order to achieve the above object, the glass substrate detection apparatus of the present invention uses a highly linear transmission sensor such as a laser beam, and arranges the light emitting position and the light receiving position in a straight line, paying attention to the refractive index of light. However, when there is no obstruction, the amount of received light is large so that it is turned on (ON), and when there is an obstruction, the amount of received light is small so that it is off (OFF).
In other words, in the case of an obstructing material such as glass, the refractive index spectral path of the glass is shifted, so that the amount of received light is reduced. Therefore, the presence or absence of an obstruction can be determined by the decrease in the amount of received light, and it is turned off when it is clear that there is an obstruction. Further, if the blocking position does not deviate so much and is within the optical path, the amount of received light is not reduced and detection is possible.
That is, the substrate detection apparatus of the present invention receives a light emitting unit that irradiates transmitted light obliquely with respect to a substrate placed on the device, and light that has passed through the substrate in a device that handles a substantially transparent substrate. A light receiving unit is provided to measure the amount of light received when the substrate is on the sample stage and when the substrate is not, and determine whether the substrate is present in the device according to the difference in the amount of received light.

According to the present invention, in a substrate such as an LCD (Liquid Crystal Device) substrate, various films are formed on the surface of the substrate in the manufacturing process, but it can be applied to all types of substrates in the entire manufacturing process. Become.
Furthermore, the presence / absence of the substrate can always be detected from when the substrate is received by a device such as a dimension measuring device until it is unloaded.

One embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram for explaining an embodiment of the present invention. FIG. 1 (a) is a cross-sectional view for explaining a glass substrate detection device for detecting the presence or absence of a glass substrate of the present invention, and FIG. 1 (b) is for explaining an optical path between a sensor light emitting part and a sensor light receiving part. FIG. 1C is a sectional view specifically explaining the optical path of light passing through the glass substrate 1 of FIG. FIG. 1A is used, for example, in a line width measuring apparatus as shown in FIG.
In FIG. 1 (a), 1 is a glass substrate, 2 is a substrate clamp base, 17 is a transfer arm, 18 is a substrate transfer hand, 121 'is a sensor light emitting unit, 122a is a light path when it goes straight, 122b is when it is refracted It is an optical path. The light output from the sensor light-emitting unit 121 ′ is preferably highly linear, such as a laser beam.

FIG. 1A shows a state in which the glass substrate 1 is carried onto the substrate clamp table 2 by the transfer arm 17 and the substrate transfer hand 18.
1 (b) and 1 (c), in the state shown in FIG. 1 (a), light passes through the glass substrate 1 from the sensor light emitting part 121 ′ provided on the substrate clamp table 2 to the sensor light receiving part 122 ′. Explain the situation.

The refractive index in the air is 1, the refractive index of the glass substrate 1 is 1.55, and light incident on the glass substrate 1 from the air at an angle of 45 degrees is bent at an angle θ degree. That is,
1 × sin45 = 1.55 × sinθ
sin θ = sin 45 ÷ 1.55
= 0.707 / 1.55
= 0.456
∴ θ = 27 ° When the thickness of the glass substrate 1 is 0.5 mm, the deviation X0 from the straight optical path is X0 = 0.5 mm × tan 45 = 0.5 mm
Xg = 0.5 mm × tan 27 = 0.5 mm × 0.51 = 0.25 mm
X0-Xg = 0.25mm
Z = 0.25 mm × sin 45 = 0.25 mm × 0.707 = 0.18 mm

  The optical path difference between the optical paths 122b and 122a is 0.18 mm, and the center of light is set to be the center of the aperture of the sensor light receiving unit 122 ′ in air, and the sensitivity at that time is 100%. When shielded by a 5 mm glass substrate, the amount of light received by the sensor light receiving unit 122 ′ is about half in the case of a sensor light receiving unit with a deviation of 0.18 mm and a diameter of 1 mm. Become.

From the above principle, the presence of glass can be recognized from the time when the glass comes above the sample clamp table 2 by the transfer arm 17 to the position where the glass is clamped on the sample clamp table 2 as shown in FIG.
The sensor light receiving unit may measure the amount of light received and determine whether or not there is a substrate depending on whether or not a predetermined threshold value is exceeded. A plurality of threshold values may be provided to determine the thickness and quality of the substrate in addition to the presence or absence of the substrate.

As another embodiment of the present invention, the total reflection mirror 123 is arranged, and the arrangement as shown in FIG.
FIG. 6 is a diagram for explaining another embodiment of the present invention. Light that has passed through the glass substrate 1 from the sensor light emitting portion 121 ′ is reflected by the total reflection mirror 123, and passes through the glass substrate 1 again to be used as a sensor. The distance (X0-Xg in FIG. 1) at which the light receiving position can be clearly identified by passing through the light receiving portion 122 ″ and being refracted twice is doubled.
By repeating this, the present invention can be applied even to a thin glass substrate or a glass substrate made of a material having a small refractive index.

As described above, according to the embodiment,
(1) Although a glass substrate forms a various film | membrane on the glass surface at a manufacturing process, it can respond to all types of board | substrates.
(2) The presence of glass can be detected from when the apparatus receives the glass substrate until it is unloaded.

  In the above embodiment, the object to be measured is a transparent glass substrate. However, the present invention can be applied to any substrate that transmits light even in a small amount and has a refractive index different from that of air or other media, and may be in a vacuum or liquid other than in air, and in an atmosphere other than air. It is obvious that it may be.

Sectional drawing for demonstrating one Example of this invention. The fragmentary sectional view for demonstrating the reflection sensor 12 in detail. The figure which shows the mounting base of the glass substrate which the conveyance robot of the conventional glass substrate and a conveyance robot convey. The figure for demonstrating the conventional board | substrate clamp method. The figure for demonstrating the conventional board | substrate conveyance method. Sectional drawing for demonstrating one Example of this invention.

Explanation of symbols

  1: Glass substrate, 2: Substrate cram table, 3: X-axis movement stage, 4: Y-axis movement stage, 5: Vibration isolation table, 6: Illumination power supply, 7: XY movement control unit, 8: Optical microscope, 9: Light guide, 10: Revolver, 11: Inspection objective lens, 12: Reflection sensor, 13: Optical axis (Z-axis) moving stage, 14: Camera, 15: Measurement control unit, 16: Monitor, 17: Transfer arm, 18: Substrate transport hand, 101, 102: Substrate reference surface, 121, 121 ′: Sensor light emitting unit, 122, 122 ′, 122 ″: Sensor light receiving unit, 191-194: Substrate receiving pin, 201, 202, 211: Reference roller 203, 204, 212: Pressing roller, 1121-1128: Center position coordinates of measurement point area, 1911, 1921, 1931, 1 41: Hole, 2001,2002, ‥‥‥, 2099,2100: substrate plane maintains pins, 2201-2212: suction pad.

Claims (1)

In a device that handles a substantially transparent substrate, a light emitting unit that irradiates transmitted light obliquely with respect to the substrate placed on the device, and a light receiving unit that receives light that has passed through the substrate are provided. A substrate detection apparatus that measures the amount of light received when the substrate is on the sample stage and determines whether the substrate is present in the device according to the difference in the amount of received light.

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