JP2005079126A - Optical fiber sensor head, its manufacturing process and wafer detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber sensor head, its manufacturing process and a wafer detector capable of detecting an object accurately while reducing the size. <P>SOLUTION: One side face of a body case 31 in the arranging direction of the forward end parts of optical fibers F1 and F2 serves as a detection surface 31A, and a light projecting window 32 and a light receiving window 33 are formed in the detection surface 31A along the inserting direction of the optical fiber. A light projecting reflective member 39 for reflecting light from the light projecting optical fiber F1 and introducing the light to the light projecting window 32 is provided in front of the forward end face of the light projecting optical fiber F1 and a light receiving reflective member 43 for reflecting light passed through the light receiving window 33 and introducing the light into the light receiving optical fiber F2 is provided in front of the forward end face of the light receiving optical fiber F2. The light receiving reflective member 43 is disposed ahead of the light projecting reflective member 39 in the inserting direction of the optical fiber. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical fiber sensor head, a manufacturing method thereof, and a wafer detection apparatus.
[0002]
[Prior art]
As disclosed in the following Patent Document 1 and the like, conventionally, there is a side view type optical fiber sensor head. For example, as shown in FIG. 8, the optical fibers 1 and 2 for projecting and receiving light, and one side surface of each of the tip portions thereof being inserted and parallel to the arrangement direction of the tip portions are detection surfaces. The main body case 3 is 3A. The light emitted from the front end surface of the light projecting optical fiber 1 is turned 90 degrees by a reflecting portion (not shown) disposed in front of the light projecting optical fiber 1 and is projected to the light projecting window 4 formed on the detection surface 3A. It is guided and irradiated from here toward a predetermined detection area. Then, for example, the light reflected by the reflector 6 disposed opposite to the light and entering the light receiving window 5 formed on the detection surface 3A is a reflecting portion (not shown) disposed in front of the front end surface of the light receiving optical fiber 2. )), The direction is changed by 90 degrees and the light is incident on the front end surface of the light receiving optical fiber 2. That is, the conventional optical fiber sensor has a configuration in which the light projection window 4 and the light receiving window 5 are arranged in parallel in a direction orthogonal to the insertion direction of the optical fibers 1 and 2.
[0003]
[Patent Document 1]
Japanese Patent No. 3400749
[0004]
[Problems to be solved by the invention]
By the way, this type of side view type sensor may be used in a detection device for each wafer 7 in which a plurality of sensors are arranged at predetermined intervals. Specifically, the above-described optical fiber sensor head is provided at one arm tip of a bifurcated arm (not shown) for wafer transfer with the detection surface 3A facing the other arm tip, and the detection surface 3A. The reflector 6 is arranged at the tip of the other arm so as to face the head.
[0005]
In this case, the bifurcated arm needs to enter the gap between the wafers 7 when the wafer is transferred. Accordingly, the optical fiber sensor head is provided so that the insertion direction of the optical fibers 1 and 2 is along the approach direction of the bifurcated arm (arrow direction in FIG. 8) so that the derived optical fibers 1 and 2 do not get in the way. That is, as shown in the figure, the arrangement direction of the light projecting window 4 and the light receiving window 5 is positioned so as to be orthogonal to the wafer 7. In this case, the amount of incident light entering the light receiving window 5 varies relatively depending on where the wafer 7 is positioned in front of the light projecting window 4 and the light receiving window 5, and the amount of light transmitted through the light receiving optical fiber 2 varies. There is a problem that the wafer cannot be detected accurately based on the above. Further, since the optical fiber sensor head has a configuration in which the light projection window 4 and the light reception window 5 are arranged along the thickness direction of the wafer 7, the thickness is required correspondingly, which is an obstacle to downsizing of the apparatus.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical fiber sensor head, a manufacturing method thereof, and wafer detection capable of accurately detecting an object to be detected while achieving downsizing. The device is on offer.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an optical fiber sensor head according to a first aspect of the present invention includes a light projecting optical fiber, a light receiving optical fiber, and a main body case into which each end portion of the optical fiber is inserted. Irradiating the light emitted from the distal end surface of the light projecting optical fiber toward a predetermined detection area outside the main body case, while receiving the light returning from the detection area toward the main body case. In the optical fiber sensor head configured to be incident on the distal end surface of the optical fiber for use, the main body case is formed with a pair of through holes arranged in parallel to each other, and one in the direction in which the pair of through holes are arranged. A side surface is a detection surface directed toward the detection region side, and tip portions of the light projecting and light receiving optical fibers are inserted into the pair of through holes from one end side, respectively. The detection surface, while passing through the through hole closer to the detection surface of the pair of through holes, from the detection surface, on the front side of the tip portion of the optical fiber inserted into the through hole A first light passage that communicates with a through hole farther from the first light passage, and the first light passage along the insertion direction of the optical fiber at a position ahead of the first light passage in the insertion direction of the optical fiber. And a second light passage that communicates with the through hole closer to the detection surface from the detection surface, and the optical fiber is inserted into the through hole far from the detection surface. The light that is inserted from the other end opposite to the optical fiber and reflects the light emitted from the optical fiber so as to pass through the first light passage, and the light that enters the first light passage is reflected by the optical fiber. A first reflecting member is provided for reflection on the tip side. And inserted into the through hole closer to the detection surface from the other end side opposite to the side where the optical fiber is inserted, and the light emitted from the optical fiber passes through the second light passage. It is characterized in that a second reflecting member is provided that reflects the light passing through the second light passage and reflects the light incident from the second light passage path toward the front end surface of the optical fiber.
[0008]
According to a second aspect of the present invention, in the optical fiber sensor head according to the first aspect, the light receiving optical fiber is inserted into a through hole closer to the detection surface, and light is projected to a through hole farther from the detection surface. It is characterized in that the optical fiber for use is inserted.
[0009]
According to a third aspect of the present invention, in the optical fiber sensor head according to the first or second aspect, the first and second light passages are fitted with a light transmissive cover at least at an opening end on the detection surface side. It is characterized in that it is configured.
[0010]
According to a fourth aspect of the present invention, there is provided a method of manufacturing an optical fiber sensor head, comprising: a light projecting optical fiber; a light receiving optical fiber; and a body case into which each end portion of the optical fiber is inserted. While irradiating the light emitted from the distal end surface of the optical fiber toward a predetermined detection region outside the main body case, the light returning from the detection region to the main body case side is irradiated with the light of the light receiving optical fiber. In the method of manufacturing an optical fiber sensor head configured to be incident on a distal end surface, the optical fiber sensor head has a pair of through holes formed in the body case, the pair of through holes being arranged in parallel to each other. One side surface in the arrangement direction of the holes is a detection surface directed toward the detection region side, and the end portions of the light projecting and light receiving optical fibers are arranged from one end side to the pair of through holes. Each of the pair of through-holes closer to the detection surface is inserted into the main body case from the detection surface on the front side of the tip portion of the optical fiber inserted into the through-hole. A first optical passage that communicates with the through hole far from the detection surface while penetrating the hole, and along the insertion direction of the optical fiber at a position ahead of the first optical passage in the insertion direction of the optical fiber. A second light passage that is aligned with the first light passage and communicates with the through hole closer to the detection surface from the detection surface is formed, and the through hole far from the detection surface has the The optical fiber is inserted from the other end opposite to the side where the optical fiber is inserted, and the light emitted from the optical fiber is reflected so as to pass through the first optical passage, and enters from the first optical passage. The emitted light is directed to the end face side of the optical fiber. A first reflecting member to be emitted, and is inserted into the through hole closer to the detection surface from the other end side opposite to the side where the optical fiber is inserted, and the light emitted from the optical fiber And a second reflecting member for reflecting the light incident from the second light passing path toward the tip end side of the optical fiber. And a step of providing both the second reflecting members with respect to the respective through holes so as to be rotatable about a rotation axis along the axial direction of the through holes, and the light from the light projecting optical fiber is Light that is irradiated from one of the first and second light passages toward the detection region and returned from the detection region through the other light passage is incident on the light receiving optical fiber. The step of rotating and adjusting both the reflecting members, and the front in this adjusted state And a step of positioning and fixing the reflecting members.
[0011]
A wafer detection apparatus according to a fifth aspect of the present invention is a wafer detection apparatus for detecting the presence or absence of each wafer in a cassette in which a plurality of wafers are accommodated at intervals, and enters between the wafers. 4. The optical fiber sensor head according to claim 1, which is provided in a transport unit that transports each wafer, and is disposed in the transport unit so as to face a detection surface of the optical fiber sensor head. A reflector that reflects the light from the optical fiber sensor head and returns it to the optical fiber sensor head side; and a light projecting device that makes the light incident on the base end face of the light projecting optical fiber derived from the optical fiber sensor head Means and a light receiving means for receiving light from the base end face of the light receiving optical fiber led out from the optical fiber, the optical fiber sensor head and the reflector, Based on a change in the amount of light received by the light receiving means, which changes depending on the presence or absence of a wafer that may be present between the optical fiber sensor head and the reflector. It is characterized in that the detection operation is performed.
[0012]
According to a sixth aspect of the present invention, in the wafer detection apparatus according to the fifth aspect of the present invention, the light projection window is configured to irradiate light having a width wider than parallel light, and the light projection of the optical fiber sensor head. It is emitted from the optical fiber for light, reflected by one of the first and second reflecting members, and passes through one of the first and second light passages corresponding thereto. On the optical path of the light to be reflected, and at least one of the optical path of the light reflected by the other reflecting member corresponding to the other light passing path and guided to the distal end surface of the optical fiber for light reception, A light beam stop means for restricting light irradiated to the detection region from the light projecting optical fiber from being reflected by another wafer surface located above or below the detection target wafer and entering the light receiving optical fiber. Is provided Having the features the time.
[0013]
[Action and effect of the invention]
<Invention of Claim 1>
According to this configuration, the first and second light passages that function as a light projecting unit and a light receiving unit that irradiate light toward the detection region and receive light from the detection region are optical fibers on the detection surface. Therefore, the optical fiber sensor head can be arranged in a narrow space without obstructing the optical fiber. Further, for example, even when a wafer is detected as described above, the alignment direction of the light projection window and the light reception window can be arranged in a posture along the approach direction of the bifurcated arm, and the optical fiber insertion direction As compared with the conventional configuration in which the light projection window and the light reception window are arranged in parallel to each other, the wafer can be detected more accurately.
[0014]
<Invention of Claim 2>
According to this configuration, since the optical fiber closer to the detection surface is the optical fiber for receiving light, the optical fiber farther from the detection surface is received from the light receiving window than the configuration using the optical fiber for receiving light. The optical path to the reflective member can be shortened, and the decrease in the amount of received light can be suppressed accordingly.
[0015]
<Invention of Claim 3>
According to this configuration, the light projecting window and the light receiving window have a configuration in which the light transmissive cover is fitted to the opening formed on the detection surface, so that even when used in an environment where dust or the like exists, It can be prevented that dust or the like adheres to the reflecting member and the light reflectance is lowered.
[0016]
<Invention of Claim 4>
For example, in the manufacturing stage, the optical axis directions of light projection and light reception can be adjusted by rotating both reflection members. Here, unlike the present invention, for example, the first reflecting member inserted into the through hole far from the detection surface is arranged in front of the second reflecting member inserted into the through hole closer to the detection surface. And the structure which forms the optical passageway connected to a detection surface corresponding to them can also be considered. However, in this configuration, for example, when performing the rotation adjustment of the reflection member closer to the detection surface, the optical path connecting the detection member and the reflection member far from the detection surface is blocked by the operator's hand. There is a problem that the optical axis cannot be adjusted.
[0017]
On the other hand, in this configuration, the second reflecting member inserted into the through hole closer to the detection surface is more optical fiber than the first reflecting member inserted into the through hole far from the detection surface. It is the structure located ahead in the insertion direction. Therefore, even when any of the reflecting members is rotated, the optical axis adjustment operation can be performed without blocking the light projecting / receiving light path.
[0018]
<Invention of Claim 5>
Even when a wafer is detected as described above, the direction in which the light projecting window and the light receiving window are arranged can be arranged in a posture along the approach direction of the bifurcated arm, and the direction orthogonal to the optical fiber insertion direction. Compared to the conventional configuration in which the light projection window and the light receiving window are arranged in parallel, the apparatus can be downsized and the wafer can be detected accurately.
[0019]
<Invention of Claim 6>
Since the diffused light is emitted from the light projection window, the light projection of the optical fiber sensor head is possible even when used as, for example, a retroreflective type optical fiber sensor in which a triangular prism is arranged oppositely, compared to the case where parallel light is emitted. It becomes easy to dispose the optical fiber sensor head and the triangular prism so that the light irradiated from the window and reflected by the triangular prism is returned to the light receiving window of the optical fiber sensor head. In addition, the influence of reflection on the surface of the wafer to be detected can be suppressed by the light iris diaphragm means, thereby improving the accuracy of wafer detection.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to FIGS.
1. Configuration of this embodiment
In FIG. 1, reference numeral 10 denotes a rack, which has a housing shape that opens to the side, and a plurality of concave grooves 12 that extend in the horizontal direction are formed on a pair of opposed inner side surfaces 11, 11 in the vertical direction. It is formed at intervals. Then, a plurality of disk-shaped wafers W are passed between the inner side surfaces 11 and 11 with their edges engaged with the concave grooves 12 of the inner side surfaces 11 and 11, thereby A plurality of wafers W are accommodated with a predetermined gap in the vertical direction.
[0021]
A hand 13 (corresponding to a transfer unit) for taking out a desired wafer W from the rack 10 has a U-shape as a whole as shown in FIG. 1, and both tip portions 13A, 13A of the U-shape are rack 10. Oriented in the direction of insertion. The hand 13 is attached to a robot arm (not shown) on the base end side, for example, and first moves to a position where the front end portion of the wafer W is interposed between both the tip portions 13A and 13A. When the detection device detects the wafer W, it moves to the lower side of the wafer W and operates to lift and transfer the wafer W.
[0022]
<Overall configuration of wafer detection apparatus>
In the wafer detection apparatus according to the present embodiment, light obtained by projecting and receiving optical fibers F1 and F2 from a main body case 31 in which a light projection window 32 and a light reception window 33 for performing light projection and reception are formed. A fiber sensor head (hereinafter referred to as “sensor head 30”) and a control unit 20 connected to the light projecting and receiving optical fibers F1 and F2 are configured.
[0023]
<Configuration of control unit>
For example, as shown in FIG. 2A, the electric circuit unit 21 in the control unit 20 is provided with an operation indicator lamp 22 for displaying the operation of the control unit 20, and a light projecting unit composed of an LED (light emitting diode). An element 23 and a light receiving element 24 made of, for example, a photodiode are provided. The light projecting optical fiber F 1 is connected to the light projecting element 23, and the light receiving optical fiber F 2 is connected to the light receiving element 24.
[0024]
The electrical configuration of the electrical circuit unit 21 is as shown in FIG. The light projecting element 23 is driven by a light projecting element driving circuit 25 and is lit in a predetermined cycle, for example. Light from the light projecting element 23 enters the body case 31 of the sensor head 30 through the light projecting optical fiber F1. It is guided and emitted from the projection window 32 of the main body case 31. The light that has entered the light receiving window 33 of the main body case 31 from a predetermined detection region is guided to the control unit 20 side through the light receiving optical fiber F <b> 2 and is incident on the light receiving element 24. The light reception signal from the light receiving element 24 is amplified by the detection circuit 26, and the detection operation of the wafer W is performed according to the intensity of the received light. This detection operation is performed based on a change in the light incident on the light receiving element 24, and outputs a detection signal to the output circuit 27 on the assumption that the wafer W exists when it falls below a predetermined level. Based on this, the output circuit 27 turns on the operation indicator lamp 22 and outputs a signal to an external circuit (for example, the controller of the robot arm) (not shown).
[0025]
<Configuration of sensor head>
The configuration of the sensor head 30 will be described with reference to FIG. In the figure, the upper part of the drawing is assumed to be the front and the lower part of the drawing is assumed to be the rear.
The main body case 31 of the sensor head 30 has a flat rectangular tube shape as a whole, and detection is such that one surface (the right surface in the figure) of a narrow set of side surfaces of two opposing side surfaces faces the detection region. It is a surface 31A. On the front end side of the detection surface 31A, as will be described later, a light receiving window 33 and a light projection window 32 are formed in this order from the front end of the detection surface 31A along the longitudinal direction (front-rear direction) of the main body case 31. Has been.
[0026]
The body case 31 is formed with a pair of through-holes 34 and 35 extending along the entire length in the longitudinal direction side by side along the arrangement direction (left-right direction) of both side surfaces of the narrow group. That is, one through-hole 34 (hereinafter, sometimes referred to as “light-receiving side through-hole 34”) is formed near the detection surface 31A in the narrow set of side surfaces, and the other through-hole 35 (hereinafter referred to as “projection”). The light-side through-hole 35 ”may be arranged closer to the side surface different from the detection surface 31A in the narrow set of side surfaces.
[0027]
Among these, the tip portion of the light projecting optical fiber F1 is inserted into the through hole 35 (light projecting side through hole 35) far from the detection surface 31A from the rear. On the other hand, the distal end portion of the light receiving optical fiber F2 is inserted into the through hole 34 (light receiving side through hole 34) closer to the detection surface 31A from the rear.
[0028]
At each tip portion of each of the optical fibers F1, F2, the outer coating is peeled off to expose the core wire S, and the core wire S is fitted into an annular sleeve 36, respectively. The sleeve 36 is fixed to the inner wall surfaces of the through holes 34 and 35 with, for example, an adhesive. The front end of the sleeve 36 is a small-diameter portion 36A whose inner diameter is smaller than that of the other portion, and the tips of the cores S of the optical fibers F1, F2 are locked to the rear surface of the small-diameter portion 36A. With such a configuration, the optical axis directions of the optical fibers F1 and F2 are positioned.
[0029]
A light projecting lens member 37 is inserted in front of the sleeve 36 in the light projecting side through hole 35 so as to be in contact with the front end surface of the sleeve 36. The light emitted from the light projecting optical fiber F <b> 1 passes through the light projecting lens member 37 and is changed to spread light according to the characteristics of the light projecting lens member 37. That is, the spread of the light beam emitted from the projection window 32 can be adjusted according to the characteristics of the projection lens member 37.
[0030]
Similarly, a light receiving lens member 38 is inserted in front of the sleeve 36 in the light receiving side through hole 34 so as to contact the front end surface of the sleeve 36. The light that has entered the light receiving window 33 passes through the light receiving lens member 38, so that light having a light amount corresponding to the characteristics of the light receiving lens member 38 is collected and enters the light receiving optical fiber F <b> 2. That is, it is possible to adjust the light receiving range that enters the light receiving window 33 from the detection region and enters the light receiving optical fiber F2 according to the characteristics of the light receiving lens member 38.
[0031]
Next, at the front end portion of the light projecting side through-hole 35, the light reflecting member 39 having a reflecting surface 39A that transmits the light projecting lens member 37 and reflects light substantially at a right angle and guides it to the detection surface 31A side. Is fitted. Further, a wall sandwiched between the light projecting side through hole 35 and the light receiving side through hole 34 and a wall sandwiched between the light receiving side through hole 34 and the detection surface 31A are lateral to the reflecting surface 39A of the light projecting reflecting member 39. Insertion holes 40 and 41 are formed in the respective positions, and the reflected light from the light projecting reflection member 39 is emitted to the outside through these insertion holes 40 and 41. Therefore, the insertion hole 41 functions as the light projection window 32. Hereinafter, the insertion hole 41 may be referred to as a light projection window 32.
[0032]
Further, an insertion hole 42 is also formed at a position in front of the light projection window 32 on the wall sandwiched between the light receiving side through hole 34 and the detection surface 31A. The light receiving side through-hole 34 is disposed in front of the light projecting reflecting member 39 and reflects light entering the insertion hole 42 from the detection region at a substantially right angle to receive the light receiving lens member 38. A light-receiving reflective member 43 having a reflective surface 43A leading to is fitted. Therefore, the insertion hole 42 functions as the light receiving window 33. Hereinafter, the insertion hole 42 may be referred to as a light receiving window 33.
[0033]
In each of the reflection members 39 and 43, the portion fitted into each of the through holes 34 and 35 has a cylindrical shape, and the portion of each of the through holes 34 and 35 to which the reflection members 39 and 43 are fitted is correspondingly formed. The cross section is circular. Accordingly, the reflecting members 39 and 43 are attached so as to be rotatable about the optical axes of the corresponding optical fibers F1 and F2 in a state of being fitted to the front end portions of the through holes 34 and 35, respectively. Then, by rotating the reflecting members 39 and 43, the directions of the reflecting surfaces 39A and 43A are changed, and the light is emitted from the light projection window 32 in the light emitting direction (optical axis center direction) and incident on the light receiving window 33. The light receiving direction can be adjusted. In addition, after the adjustment, the reflecting members 39 and 43 are fixed with, for example, an adhesive. Further, knobs 39B and 43B having diameters larger than those of the other portions are provided on the opposite side of the reflecting surfaces 39A and 43A among the reflecting members 39 and 43, respectively.
[0034]
<Sensor head arrangement and reflector>
As shown in FIG. 5, the sensor head 30 is accommodated in one tip portion 13 </ b> A of the hand 13. Specifically, the sensor head 30 is screwed via a fixing portion 44 protruding from the main body case 31 with the detection surface 31A facing the other tip portion 13A side of the hand 13. On the other hand, a reflector 50 is disposed on the other tip portion 13 </ b> A of the hand 13 so as to face the detection surface 31 </ b> A of the sensor head 30. In this reflector 50, for example, as shown in FIG. 6B, the reflecting surface 51 has a corner cube structure, and the light projected toward the reflecting surface 51 can be returned to the light projecting position. , So-called regressive reflection type. A fixing portion 53 is provided behind the reflecting surface 51 as shown in FIG. 3A, and is screwed to the hand 13 through the fixing portion 53.
[0035]
2. Operation of wafer detector
As shown in FIG. 5, the light from the light projecting element 23 of the control unit 20 is emitted from the front end surface through the light projecting optical fiber F <b> 1, and is narrowed down to a light beam having a predetermined width by the light projecting lens member 37. Then, the direction is changed at a right angle by the reflecting surface 39 </ b> A of the light reflecting reflection member 39, and the light is irradiated from the light projecting window 32 toward the reflector 50. Of the light reflected by the reflector 50, the light that has entered the light receiving window 33 is also turned at a right angle by the reflecting surface 43 A of the light receiving reflecting member 43 and converged by the light receiving lens member 38. Then, the converged light enters the front end surface of the light receiving optical fiber F2, passes through the light receiving optical fiber F2, and is received by the light receiving element 24 of the control unit 20. Here, if the wafer W is interposed between the sensor head 30 and the reflector 50, the amount of light received by the light receiving element 24 is reduced, and the detection signal is output to the output circuit 27 because the wafer W exists because it is below a predetermined level. Based on this, the output circuit 27 turns on the operation indicator lamp 22 and outputs a signal to an external circuit.
[0036]
In the present embodiment, as shown in FIG. 7, the light emitted from the light projection window 32 is reflected by the upper and lower wafers W ′ sandwiching the wafer W to be detected, enters the light receiving window 33, and finally receives light. The light beam is narrowed by the light projecting lens member 37 and the light receiving lens member 38 so as not to enter the front end surface of the optical fiber F2 (corresponding to the configuration of claim 6). Therefore, in the present embodiment, the light projecting lens member 37 and the light receiving lens member 38 correspond to “light beam diaphragm means”. Such a configuration can be realized not only by adjusting the characteristics of the light projecting lens member 37 and the light receiving lens member 38 but also by adjusting the opening diameters of the light projecting window 32 and the light receiving window 33.
[0037]
3. Effects of this embodiment
According to the above configuration, the light projecting window 32 and the light receiving window 33 are arranged side by side in the direction along the insertion direction of the optical fibers F1 and F2, so that the optical fibers F1 and F2 do not get in the way. 13 can be made thin enough to enter between the wafers W. In addition, the sensor head 1 can perform light projection and reception toward the end surface of the wafer W with the alignment direction of the light projection window 32 and the light reception window 33 aligned with the surface of the wafer W. Compared to the conventional configuration in which the light projecting window and the light receiving window are arranged in the orthogonal direction, the wafer can be detected more accurately.
[0038]
In addition, in the above-described conventional configuration, since each reflecting member is provided side by side in the direction in which the light projecting window and the light receiving window are arranged, the optical axis of the light projected from the light projecting window 32 according to the width dimension of the reflecting member. And the pitch interval with the optical axis of the light received by the light receiving window is widened. However, in the present embodiment, the optical axis of the light projected from the light projection window 32 and the light reception window are received without being limited by the width dimension of each of the reflecting members 39 and 43 as compared with the conventional configuration. The pitch interval with the optical axis of the light can be reduced as much as possible.
[0039]
In the present embodiment, since the optical fiber closer to the detection surface 31A is the light receiving optical fiber F2, the optical fiber farther from the detection surface 31A is received than the configuration in which the optical fiber F2 for light reception is used. The optical path from the window to the light receiving reflection member can be shortened, and a decrease in the amount of received light can be suppressed accordingly (corresponding to the configuration of claim 2).
[0040]
Further, the light receiving reflection member 43 corresponding to the optical fiber F2 closer to the detection surface 31A is inserted into the optical fibers F1 and F2 than the light reflection reflecting member 39 corresponding to the optical fiber F1 farther from the detection surface 31A. It is the structure located ahead in the direction. Accordingly, even when any of the reflecting members 39 and 43 is operated to rotate, the optical axis adjustment work can be performed without causing a problem that the light path of the light projecting / receiving light is blocked by the operator's hand or the like (claim). Corresponding to the configuration of item 4).
[0041]
In the present embodiment, the reflecting members 39 and 43 are rotatably provided in the through-holes 34 and 35 in the manufacturing stage. Therefore, the reflecting members 39 and 43 are rotated to project and receive light. The reflecting members 39 and 43 can be positioned and fixed after adjusting the optical axis direction.
[0042]
<Other embodiments>
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.
(1) Contrary to the above embodiment, the optical fiber closer to the detection surface 31A is the light receiving optical fiber F2, and the optical fiber far from the detection surface 31A is the projecting optical fiber F1. Also good. If it is this structure, the optical path from the reflection member for light projection to a light projection window can be shortened, and the light emission amount fall can be suppressed by that much.
[0043]
(2) Some wafers are coated with, for example, an oxide film or a nitride film that absorbs light in a certain wavelength band. In the above embodiment, in order to detect a wafer having such a low light reflectance, A mirror reflection type sensor in which the reflectors 50 are arranged to face each other is provided. However, the present invention is not limited to this, and the present invention is applied to a so-called reflective sensor that detects a wafer based on the presence or absence of reflected light on the surface of the detected object without using the reflector 50 if the light reflectance of the detected object is high. You may apply.
[0044]
(3) In the above embodiment, the light projection window 32 and the light reception window 33 are simply the insertion holes 41 and 42. This is because wafer detection is normally performed in a clean room that is almost free of dust and the like, and when used in an environment where dust or the like is present, the insertion holes 41 and 42 may be sealed with a transparent cover. (Equivalent to the structure of claim 3).
[0045]
(4) The “reflector” referred to in the present invention may be a triangular prism or a simple reflector in addition to the reflector 50 having the corner cube type structure.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a rack and a hand in which wafers are stored according to an embodiment of the present invention.
FIG. 2 is a configuration diagram of the control unit.
FIG. 3 is a sectional view of a sensor head.
FIG. 4 is a side view and a top view of a sensor head.
FIG. 5 is a simplified diagram showing a sensor head and a reflector housed in the hand.
FIG. 6 is a top view of the reflector and a view seen from the reflecting surface side.
FIG. 7 is a schematic diagram showing the relationship between the light beam of the projected light and the wafer.
FIG. 8 is a perspective view showing a conventional sensor head.
[Explanation of symbols]
10 ... Rack
23 ... Projection element (projection means)
24. Light receiving element (light receiving means)
30 ... Sensor head (optical fiber sensor head)
31 ... Body case
31A: Detection surface
32 ... Floodlight window
33 ... Light receiving window
37 ... Projection lens member
38. Light receiving lens member
39 ... Reflective member for light projection
43 ... Reflective member for light reception
50 ... Reflector (reflector)
F1: Optical fiber for light projection
F2: Optical fiber for receiving light
W ... Wafer (wafer to be detected)
W '... wafer

Claims (6)

A light projecting optical fiber; a light receiving optical fiber; and a main body case into which each front end portion of the optical fiber is inserted, and the light emitted from the front end surface of the light projecting optical fiber. In the optical fiber sensor head configured to irradiate the light toward the main body case from the detection region while irradiating the external predetermined detection region, the optical fiber sensor head is configured to enter the front end surface of the light receiving optical fiber. The body case is formed with a pair of through-holes arranged in parallel to each other, and one side surface in the direction in which the pair of through-holes are aligned is a detection surface directed toward the detection region side,
The end portions of the light projecting and receiving optical fibers are respectively inserted into the pair of through holes from one end side,
In the main body case, on the front side of the tip portion of the optical fiber inserted into the through-hole, while passing through the through-hole closer to the detection surface of the pair of through-holes, the detection surface A first light passage that communicates with a through-hole far from the detection surface, and the first light passage along the insertion direction of the optical fiber at a position in front of the first light passage in the insertion direction of the optical fiber. A second light passage that is aligned with the path and communicates with the through hole closer to the detection surface from the detection surface, respectively.
The through hole far from the detection surface is inserted from the other end opposite to the side where the optical fiber is inserted, so that the light emitted from the optical fiber passes through the first light passage. And a first reflecting member that reflects the light incident from the first light passage to the tip end side of the optical fiber is provided,
The through hole closer to the detection surface is inserted from the other end side opposite to the side where the optical fiber is inserted, so that light emitted from the optical fiber passes through the second light passage. And an optical fiber sensor head, wherein a second reflecting member is provided for reflecting the light incident on the second light passage path toward the tip end side of the optical fiber. 2. The optical fiber according to claim 1, wherein the light receiving optical fiber is inserted into a through hole closer to the detection surface, and a light projecting optical fiber is inserted into a through hole far from the detection surface. The sensor head. 3. The optical fiber sensor according to claim 1, wherein the first and second light passage paths are configured by fitting a light-transmitting cover at least at an opening end on the detection surface side. 4. head. A light projecting optical fiber; a light receiving optical fiber; and a main body case into which each front end portion of the optical fiber is inserted, and the light emitted from the front end surface of the light projecting optical fiber. A method of manufacturing an optical fiber sensor head configured to irradiate a predetermined external detection area while allowing light that has returned from the detection area to the main body case side to be incident on a distal end surface of the light receiving optical fiber. In
The optical fiber sensor head is
The main body case is formed with a pair of through holes arranged in parallel to each other, and one side surface in the direction of arrangement of the pair of through holes is a detection surface directed toward the detection region side,
The end portions of the light projecting and receiving optical fibers are respectively inserted into the pair of through holes from one end side,
In the main body case, on the front side of the tip portion of the optical fiber inserted into the through-hole, while passing through the through-hole closer to the detection surface of the pair of through-holes, the detection surface A first light passage that communicates with a through-hole far from the detection surface, and the first light passage along the insertion direction of the optical fiber at a position in front of the first light passage in the insertion direction of the optical fiber. A second light passage that is aligned with the path and communicates with the through hole closer to the detection surface from the detection surface, respectively.
The through hole far from the detection surface is inserted from the other end opposite to the side where the optical fiber is inserted, so that the light emitted from the optical fiber passes through the first light passage. And a first reflecting member that reflects the light incident from the first light passage to the tip end side of the optical fiber is provided,
The through hole closer to the detection surface is inserted from the other end side opposite to the side where the optical fiber is inserted, so that light emitted from the optical fiber passes through the second light passage. And a second reflecting member that reflects the light incident from the second light passage to the tip end side of the optical fiber is provided.
Providing the first and second reflecting members so as to be rotatable with respect to the respective through-holes around a rotation axis along the axial direction of the through-hole;
Light from the light projecting optical fiber is irradiated from one of the first and second light passages toward the detection region, and returns from the detection region through the other light passage. Rotating both the reflecting members so that the incident light enters the light receiving optical fiber;
And a step of positioning and fixing the reflecting members in the adjusted state. A wafer detection device for detecting the presence or absence of each wafer in a cassette in which a plurality of wafers are stored at intervals,
The optical fiber sensor head according to any one of claims 1 to 3, wherein the optical fiber sensor head is provided in a transfer unit that enters between the wafers and transfers the wafers.
A reflector that is disposed in the transport section so as to face the detection surface of the optical fiber sensor head, reflects light from the optical fiber sensor head, and returns the optical fiber sensor head to the optical fiber sensor head side;
A light projecting means for causing light to enter the base end face of the light projecting optical fiber derived from the optical fiber sensor head;
Light receiving means for receiving light from the base end face of the light receiving optical fiber derived from the optical fiber,
The optical fiber sensor head and the reflector are arranged so as to sandwich the end face side of each wafer, and change depending on the presence or absence of a wafer that can exist between the optical fiber sensor head and the reflector. A wafer detection apparatus that performs the wafer detection operation based on a change in the amount of light received by the light receiving means. The light projecting window is configured to irradiate light that is wider than parallel light, and is emitted from the light projecting optical fiber of the optical fiber sensor head. Corresponding to the light path of light passing through one of the first and second light paths corresponding to the light reflected by one of the reflecting members and from the other light path. The light irradiated to the detection region from the light projecting optical fiber is detected on at least one of the light paths reflected by the other reflecting member and guided to the tip surface of the light receiving optical fiber. 6. A wafer detection device according to claim 5, further comprising a light aperture stop means for restricting light reflected from another wafer surface above or below the target wafer and entering the light receiving optical fiber. apparatus.

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