JPH11145256A - Thin type board detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a constitution of an irradiation means by generating fan-shaped beam flux which converges in the thickness direction of a thin type board and disperses in the width direction and irradiating an outer edge end face of a thin type board. SOLUTION: An irradiation means 11 projects light L1 of a light emitting source 11a and generates a fan-shaped beam flux L2 which converges in a thickness direction of a thin type board and disperses in a width direction (w) of a thin type board 2. Then, the beam flux L2 is cast on a thin type board outer edge end face 21 by a lens 11b (a columnar rod lens whose axis is arranged on a horizontal surface at right angles to an optical axis of a light emitting source 11a). A photosensitive means 12 consists of a plurality of photosensitive parts 12A, 12A arranged to hold the irradiation means 11 between. Each photosensitive part 12A converges reflection light L3 by a converging lens 12a and the converged light L4 is converted to an electric signal by a photosensitive lens 12b. Since the fan-shaped beam flux 12 is generated by one lens 11b and irradiates an outer edge face of a thin type board, a constitution of an irradiation means can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin substrate detecting apparatus for detecting the presence of a thin substrate such as a semiconductor wafer or a glass substrate.

[0002]

2. Description of the Related Art As an example of a system for transporting a thin substrate by using a transport robot, there is provided irradiation means for irradiating the outer edge of the thin substrate, and light receiving means capable of receiving reflected light from the outer edge of the thin substrate. Using a thin substrate detection device that detects the presence or absence of a thin substrate based on whether or not reflected light is received by the means, and confirming the presence of the thin substrate to be conveyed by the thin substrate detection device, There is known a system for executing the transfer of a sheet.

Here, the conventional thin substrate detecting device comprises two sets of irradiating means and light receiving means, and one of the irradiating means irradiates a predetermined position on the outer edge of the thin substrate and reflects the light reflected from the outer edge of the thin substrate at this time. Is received by one of the light receiving means, and the other irradiation means irradiates a predetermined position on the outer edge of the thin substrate different from the predetermined position, and the reflected light of the outer edge of the thin substrate at this time is received by the other light receiving means. It is configured.

[0004]

However, according to the conventional thin substrate detecting apparatus, the irradiating means is provided with a function of irradiating two different positions on the outer edge of the thin substrate. There is a problem that it is complicated.

SUMMARY OF THE INVENTION In view of the above problems, it is a main object of the present invention to provide a thin substrate detecting device capable of simplifying the structure of an irradiation means.

[0006]

A thin substrate detecting apparatus according to the present invention comprises: irradiating means for irradiating an outer edge of a thin substrate; and light receiving means capable of receiving reflected light from the outer edge of the thin substrate. In a thin substrate detecting apparatus for detecting the presence or absence of a thin substrate based on whether or not the reflected light is received by the means, the irradiating means includes a light emitting source, and light from the light emitting source is incident, and a thickness direction of the thin substrate. And a lens for irradiating the outer edge of the thin substrate with the light beam, and generating a fan-shaped light beam that diverges in the width direction of the thin substrate, and the light receiving unit sandwiches the irradiation unit. It is characterized by comprising a plurality of light receiving units arranged.

Here, when the thin substrate is a disk-shaped semiconductor wafer having an orientation flat or a notch, the irradiating means does not pass the optical axis of the semiconductor wafer through the center position of the semiconductor wafer. The light receiving sections at both ends of the plurality of light receiving sections of the light receiving section can receive reflected light even when one end of the orientation flat of the semiconductor wafer is positioned on the optical axis of the irradiation section. It is preferable to be arranged in a proper range.

Further, it is desirable that the thin substrate detecting device is provided in a transfer robot.

[0009]

According to the thin substrate detecting apparatus of the present invention, a fan-shaped light beam is generated by one lens, and this light beam irradiates the outer edge of the thin substrate. Can be achieved. In addition, since the light beam that irradiates the outer edge of the thin substrate has a width in the width direction of the thin substrate, the angle of spread of the reflected light at the outer edge of the thin substrate is large. Therefore, even when the light receiving means is set at a position which is relatively large, the light receiving means can sufficiently receive the reflected light, and the detection rate increases. Furthermore, since the light beam irradiating the outer edge of the thin substrate is converged in the thickness direction of the thin substrate, the thin substrate is erroneously detected by irradiating the outer edge of another thin substrate adjacent in the thickness direction by mistake. Can be prevented.

In the case where the thin substrate is a disc-shaped semiconductor wafer having an orientation flat or a notch, the irradiation means may be
The semiconductor wafer is arranged so that its optical axis does not pass through the center position of the semiconductor wafer. Thus, when the optical axis of the irradiation unit passes through the center position of the semiconductor wafer, much of the light emitted from the irradiation unit is reflected by the outer edge of the semiconductor wafer, returns to the irradiation unit, and is received by the light receiving unit. Although the detection rate decreases due to the decrease in the amount, the light receiving amount of the light receiving means increases due to the configuration in which the optical axis of the irradiation means does not pass through the center position of the semiconductor wafer as described above. Can be improved. This is particularly effective when the outer edge of the semiconductor wafer is coated with an Al film or a SiO ₂ film or the like and is close to a mirror surface.

When the light receiving portions at both ends of the plurality of light receiving portions of the light receiving portion are positioned at one end of the orientation flat of the semiconductor wafer on the optical axis of the irradiation portion, in other words, the light receiving amount of the light receiving portion is minimized by the orientation flat. Even if it can be
By arranging the semiconductor wafer in a range where the reflected light can be received, the positional relationship of the semiconductor wafer with respect to the thin substrate detection device, for example, the distance (working distance W · D) between the semiconductor wafer and the thin substrate detection device, Even if the position of the orientation flat is not constant, reflected light can be received, so that the detection rate of the presence or absence of the semiconductor wafer can be improved.

Further, by providing the thin substrate detecting device in the transfer robot, the following effects are produced as compared with the case where the thin substrate detecting device is provided for each cassette for storing semiconductor wafers, for example. In other words, when a thin substrate detecting device is provided for each cassette for storing semiconductor wafers, the number of thin substrate detecting devices corresponding to the number of cassettes is required, and the installation space is increased, and the semiconductor wafer to be transported is also required. Although a dedicated drive mechanism for moving the thin substrate detection device according to the position is required, when the thin substrate detection device is provided in a transport robot, the thin substrate detection device is commonly used for each cassette. Since it can be used, one thin substrate detection device is sufficient, the installation space is reduced, and the drive mechanism of the transfer robot can be used to move the thin substrate detection device.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing a basic configuration of a thin substrate detecting apparatus according to one embodiment, and FIG. 2 is a side view showing an irradiation unit.

In FIG. 1 and FIG. 2, a thin substrate detecting device 1 includes an irradiating means 11 for irradiating an outer edge 21 of a thin substrate 2 (in this embodiment, a semiconductor wafer, but may be a glass substrate). And a light receiving means 12 capable of receiving the reflected light from the thin substrate outer edge 21. The presence or absence of the thin substrate 2 is detected based on whether or not the light receiving means 12 receives the reflected light.

The irradiating means 11 receives a light source 11a (semiconductor laser in this embodiment) and light L1 from the light source 11a, and receives light L1 from the light source 11a in the thickness direction of the thin substrate 2 (perpendicular to the drawing).
And a lens 11b that irradiates the thin substrate outer edge 21 with the light beam L2 (in this embodiment, the axis is horizontal and the light is emitted). (A cylindrical rod lens arranged perpendicular to the optical axis of the light L1 of the light source 11a). The irradiating means 11 includes a rectangular stop 11c for cutting unnecessary light and removing noise light.

The light receiving means 12 comprises a plurality of light receiving sections 12A, 12A arranged with the irradiation means 11 interposed therebetween. Each light receiving section 12A is formed by a condenser lens 12a for condensing the reflected light L3 and a condenser lens 12a. A light receiving element 12b that receives the collected light L4 and converts it into an electric signal.
Each light receiving unit 12A includes a filter 12c for transmitting only light in the same wavelength region as the laser wavelength of the semiconductor laser 11a and removing external light.

According to the thin substrate detecting apparatus 1 according to the present embodiment, a fan-shaped light beam L2 is formed by one lens 11b.
Is generated, and this light beam L2 irradiates the thin substrate outer edge 21, so that the configuration of the irradiating means 11 can be simplified. Further, since the light beam L2 irradiating the thin substrate outer edge 21 has a spread in the width direction w of the thin substrate 2, the spread angle of the reflected light L3 on the thin substrate outer edge 21 is large, and therefore, Even if the thin substrate 2 is set at a position (for example, a position shown by a two-dot chain line in FIG. 1) which is relatively largely deviated from a reference position (a position shown by a solid line in FIG. 1),
Can sufficiently receive the reflected light L3, and the detection rate increases. Further, since the light beam L2 irradiating the outer edge 21 of the thin substrate is converged in the thickness direction t of the thin substrate 2, the outer edge of another thin substrate adjacent in the thickness direction t is erroneously illuminated. Can be prevented from being erroneously detected.

Further, when the thin substrate detecting device 1 is provided on a transfer robot (not shown), the following effects are obtained as compared with the case where the thin substrate detecting device 1 is provided for each cassette for storing semiconductor wafers, for example. Occurs. That is, in the case where the thin substrate detecting devices 1 are provided for each cassette for storing semiconductor wafers, the number of thin substrate detecting devices 1 corresponding to the number of cassettes is required, the installation space is enlarged, and the semiconductor to be transported is increased. Although a dedicated drive mechanism for moving the thin substrate detecting device 1 according to the position of the wafer is required, when the thin substrate detecting device 1 is provided in a transfer robot, Since a single thin substrate detection device 1 is sufficient because it can be used in common for a cassette, the installation space is reduced, and a drive mechanism of a transfer robot can be used to move the thin substrate detection device 1.

In the above embodiment, the lens 11
Although a rod lens having a cylindrical shape is used as b, the shape is not limited to a cylindrical shape as long as the lens can generate the above-mentioned fan-shaped light beam L2, such as a columnar lens having a semicircular cross section.

FIG. 3 is a plan view of a thin substrate detecting apparatus according to another embodiment of the present invention.

In FIG. 3, the thin substrate detecting device 1 is configured by arranging an irradiating unit 11 and a light receiving unit 12 on a housing 100.

The irradiating means 11 includes the irradiating means 1 shown in FIG.
Similarly to 1, the light source 11a (semiconductor laser) is disposed in front of the light source 11a, the light of the light source 11a is incident thereon, and the light is focused in the thickness direction of the semiconductor wafer 2 (the direction perpendicular to the drawing); A special lens 11b such as a rod lens, a cylindrical lens, or a toroidal lens that generates a fan-shaped light beam diverging in the width direction of the semiconductor wafer 2 and irradiates the semiconductor wafer outer edge 21 with the light beam.
And The irradiating means 11 includes a rectangular stop 11c for cutting unnecessary light and removing noise light.

As shown in FIG. 3, the irradiating means 11 adjusts the optical axis L 2 _O of the fan-shaped light beam to the center position O of the semiconductor wafer 2.
It is arranged not to pass through. Accordingly, when the optical axis L2 _O illumination means 11 is configured so as to pass through the center position O of the semiconductor wafer 2, much of the light emitted from the illumination means 11 is reflected by the outer end face 21 of the semiconductor wafer 2 Returning to the irradiation means 11, the light receiving means 12A, 12B, 12C, 1
Although the detection rate decreases due to the decrease in the amount of light received by the 2D and 12E, the optical axis L of the irradiation unit 11 is reduced as described above.
By configuring so that 2 _O does not pass through the center position O of the semiconductor wafer 2, the light receiving means 12A, 12B, 12C, 1
The amount of received light of 2D and 12E increases, and the detection rate can be improved. In particular, the outer edge 21 of the semiconductor wafer 2
This is effective when the film is coated with an L film or a SiO ₂ film or the like and is in a state close to a mirror surface.

The light receiving means 12 includes a plurality of light receiving sections 12A, 12B, 12C, 12
D, 12E, and each light receiving section 12A, 12B, 12
C, 12D and 12E are a condenser lens 12a for condensing the reflected light L3 and light L4 condensed by the condenser lens 12a.
And a light receiving element 12b that receives the light and converts it into an electric signal. Further, each of the light receiving sections 12A, 12B, 12C, 1
2D and 12E are provided with the semiconductor laser 11a as required.
And a filter 12c (FIG. 1) for transmitting only light in the same wavelength region as the laser wavelength and removing external light.

Here, the plurality of light receiving sections 12 of the light receiving means 12
A, 12B, 12C, 12D, both ends of the light receiving portion 12A of 12E, 12E, even if the one end 22a of the orientation flat 22 of the semiconductor wafer 2 is positioned on the optical axis L2 _O illumination means 11, the reflected light It is arranged in a range where light reception of L3 is possible.

[0027] That is, as shown by the solid line in FIG. 4, one of the light receiving unit 12A, when one end 22a of the orientation flat 22 of the semiconductor wafer 2 is positioned on the optical axis L2 _O illumination means 11, the edge of the orientation flat 22 Angle θ ₁ between the virtual line VL extending vertically from the portion 22a and the optical axis L3 of the light receiving portion 12A.
Are arranged so as to coincide with the angle θ ₂ between the virtual line VL and the optical axis L 2 _O of the irradiation unit 11, and the other light receiving unit 12 E is disposed on the semiconductor wafer 2 as shown by a broken line in FIG. One end 22b of the orientation flat 22 is connected to the optical axis L2 _{O of the} irradiation unit 11.
When positioned above, the angle θ ₁ ′ between the virtual line VL extending vertically from the end 22b of the orientation flat 22 and the optical axis L3 of the light receiving unit 12E is equal to the virtual line VL and the optical axis L2 of the irradiation unit 11. It is arranged so as to match the angle θ ₂ ′ with _O.

By arranging the light receiving portions 12A and 12E at both ends in this manner, the orientation flat 22 of the semiconductor wafer 2 is formed.
If the end 22a, 22b is positioned on the optical axis L2 _O illumination means 11, in other words, in a case where the light receiving unit 12A by orientation flat 22, 12B, 12C, 12D, the received light amount of the entire 12E can be minimized also, it is possible to detect the presence or absence of the semiconductor wafer 2, and when the end portion 22a of the orientation flat 22, 22b is not located on the optical axis L2 _O of the illumination means 11, the light receiving portion 12A at both ends, inner 12E Since the amount of light received by the other light receiving units 12B, 12C, and 12D located at
The presence or absence of the semiconductor wafer 2 can be detected by 12D.

[Brief description of the drawings]

FIG. 1 is a plan view showing a basic configuration of a thin substrate detection device according to an embodiment of the present invention.

FIG. 2 is a side view illustrating a configuration of an irradiation unit.

FIG. 3 is a plan view of a thin substrate detection device according to another embodiment of the present invention.

FIG. 4 is an explanatory diagram for explaining a positional relationship between a semiconductor wafer and light receiving units at both ends in the same apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Thin substrate detection device 11 Irradiation means 11a Light emitting source (semiconductor laser) 11b Lens 11c Aperture 12 Light receiving means 12A, 12B, 12C, 12D, 12E Light receiving part 12a Condensing lens 12b Light receiving element 12c Filter 2 Thin substrate (semiconductor wafer or glass) Substrate) 21 Outer edge end face 22 Orientation flat 22a, 22b End L1 Light from light source L2 Fan-shaped light beam L2 _O Optical axis L3 Reflected light L4 Light condensed by condensing lens O Center position of semiconductor wafer VL Virtual line θ ₁ , θ ₁ 'The angle between the virtual line extending vertically from the end of the orientation flat and the optical axis of the light-receiving unit θ ₂ , θ ₂ ' The angle between the virtual line and the optical axis of the irradiation means w Width direction of the thin substrate t Thickness direction of thin substrate

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seinosuke Mizuno 28, Kitaimaji Setona, Onishi-shi, Aichi Pref.

Claims (7)

[Claims] 1. An irradiating means for irradiating an outer edge of a thin substrate, and a light receiving means capable of receiving reflected light from the outer edge of the thin substrate, wherein the light is thinned based on whether or not the reflected light is received by the light receiving means. In the thin substrate detecting device for detecting the presence or absence of a substrate, the irradiating means includes a light emitting source, and light from the light emitting source is incident, converges in a thickness direction of the thin substrate, and diverges in a width direction of the thin substrate. A lens that generates a fan-shaped light beam and irradiates the thin substrate outer edge with the light beam; wherein the light receiving unit includes a plurality of light receiving units arranged with the irradiation unit interposed therebetween. Thin substrate detection device. 2. The semiconductor wafer according to claim 1, wherein the thin substrate is a disc-shaped semiconductor wafer having an orientation flat or a notch, and the irradiating means is arranged such that an optical axis of the thin wafer is positioned at a center of the semiconductor wafer. The light receiving sections at both ends of the plurality of light receiving sections of the light receiving section, even when one end of the orientation flat of the semiconductor wafer is positioned on the optical axis of the irradiation section, A thin substrate detection device which is arranged in a range where light can be received. 3. The light receiving unit at both ends of the plurality of light receiving units of the light receiving unit, wherein one end of the orientation flat of the semiconductor wafer is located on the optical axis of the irradiation unit. A thin substrate detection device, wherein an angle formed between an imaginary line extending perpendicularly from the portion and an optical axis of the light receiving section matches the angle formed between the imaginary line and the optical axis of the irradiation means. . 4. The thin substrate detecting device according to claim 1, wherein the thin substrate detecting device is provided in a transfer robot. 5. The light-emitting device according to claim 1, wherein the light-emitting source is configured by a semiconductor laser, the lens is configured by a rod lens, and each of the light-receiving units is A thin substrate detection device comprising: a condenser lens for condensing the reflected light; and a light receiving element for receiving the light condensed by the condenser lens and converting the light into an electric signal. 6. The thin substrate detecting device according to claim 5, wherein the light receiving unit includes a filter that can transmit only light in the same wavelength region as the laser wavelength of the semiconductor laser. 7. The thin substrate detecting device according to claim 5, wherein the irradiating means includes a rectangular stop.