JPH06329206A - Wafer cassette, band for carrying wafer cassette and shape detecting device theerefor - Google Patents

Abstract

PURPOSE:To obtain a wafer cassette capable of reducing generation of dust during handling process including transport by providing a cassette part for storing a plurality of wafers, a box for storing the cassette part and a shock absorbing means for absorbing vibration applied to the box. CONSTITUTION:A wafer cassette has a wafer storing space for storing a plurality of wafers 42 by arranging them concentrically and a cassette part 43 provided with a guide groove engaging with a part of the peripheryl of the wafer for deciding position of the wafer and a box 44 for storing the cassette part on the inwall of a body. A cassette member 43 is stored floatably in the box 44 via a shock absorbing means consisting of a plurality of coil springs and the like. Thereby, vibration transmitted to the wafer 42 stored in the cassette part 43 can be prevented by absorbing the vibration applied to the box 44 by the shock absorbing means and attenuating it before transmission to the cassette part 43 and damage of the wafer 42 and generation of dust can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a wafer cassette for storing a plurality of semiconductor wafers, a hand for carrying the wafer cassette, and a device for detecting the shape of the wafer cassette.

[0002]

2. Description of the Related Art Generally, in manufacturing a semiconductor, a wafer is transferred between manufacturing apparatuses that execute respective manufacturing processes. A predetermined number of wafers are stored in the wafer cassette, and the wafers are transferred by a predetermined transfer device while being stored in the wafer cassette. Then, by using the wafer cassette, it is possible to efficiently carry a large number of wafers.

Techniques relating to wafer cassettes and the transportation of wafer cassettes are disclosed in the following documents, for example. (1) JP-A-62-57882 (2) JP-A-63-150932 (3) JP-A-63-203464 (4) JP-A-1-155640 (5) JP-A-2- In Japanese Patent Laid-Open No. 72650, a cam member for holding the wafer cassette at an inclination and supporting it on one wall surface of the wafer cassette is provided in Document (1). Document (2) discloses a technique using a shape memory alloy as a means for opening and closing the fingers of a hand. Further, in the document (3), a shock absorber is attached between a carriage that conveys a wafer cassette and a loading platform on the carriage. In reference (4), the fingers for holding the wafer cassette are provided with a finger for vertical placement and a finger for horizontal rising. And
Document (5) discloses a technique of detecting the attitude state of a wafer by a presence sensor and a distance measuring sensor when the wafer is unloaded from the cassette.

[0004]

By the way, each of the techniques disclosed in the above-mentioned documents has the following problems. When the hand opening / closing mechanism is provided to hold the wafer cassette as in Reference (2), the opening / closing mechanism causes dust generation. Further, if a mechanism for sandwiching the cassette with the fingers of the hand is adopted to hold the wafer cassette as in Reference (4), dust is easily generated because the finger and the edge of the cassette rub against each other.

Further, when the attitude state of the wafer in the wafer cassette is detected as in Reference (5), there is no information obtained when the wafer is inserted. Moreover, since the surface of the silicon wafer is generally a mirror surface, a general sensor for detecting scattered light cannot be used. Therefore, the sensors that can detect the wafer are limited, and it is difficult to reduce the cost of the sensor.

Further, if a vibration isolation mechanism is attached to the side of the transport vehicle as in Reference (3), the trolley device becomes large in size, and a large space for the transport vehicle to travel must be secured. Further, when vibration occurs in the manufacturing apparatus when the wafer cassette is transferred to the manufacturing apparatus side, it is necessary to provide another vibration isolation mechanism.

It is an object of the invention of each claim to provide a wafer cassette, a wafer cassette transfer hand, and a wafer cassette shape detecting device which generate little dust.

[0008]

In order to achieve the above-mentioned object, the invention of claim 1 adds a cassette part for accommodating a plurality of wafers, a box for accommodating this cassette part, and this box. It is a wafer cassette provided with a shock absorbing means for absorbing vibration.

Further, according to the invention of claim 2, a plurality of wafers are accommodated in the main body, and the wafers are pivotally supported by the main body to guide the wafers when the wafers are accommodated in the main body and are rotated while being accommodated in the main body. And a wafer guide for holding the wafer.

According to the invention of claim 3, a wafer cassette transfer hand comprising a finger to be inserted into the wafer cassette and a deformable portion which can be freely expanded and contracted and is deformed when expanded to engage with the wafer cassette. Is.

Further, the invention of claim 4 comprises a cassette elevator for raising and lowering the wafer cassette, and a detector for detecting the shape of the wafer cassette by entering the wafer cassette as the wafer cassette is raised and lowered. This is a wafer cassette shape detection device. And according to these inventions, dust generation can be prevented.

[0012]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3 show a first embodiment of the present invention, and reference numeral 1 in FIG. 1 denotes a wafer cassette transfer hand (hereinafter referred to as a hand). In this hand 1, a hand base 2 is connected to the tip of a movable arm 3, and two fingers 4, 4 are vertically provided on the hand base 2. The arm 3 moves the hand base 2 to an arbitrary position, and the hand base 2 changes its posture with respect to the arm 3.

The fingers 4 and 4 are formed in a cylindrical shape having the same diameter, and their lengths (projection amounts) are also set to be equal.
Furthermore, the fingers 4 and 4 are fixed to the hand base 2,
They run parallel to each other. The distance between the fingers 4 and 4 is always constant.

A deformable portion 5 is provided at the tip of each finger 4. The deformable portion 5 is made of a material having appropriate elasticity and has a space for introducing a fluid therein. A predetermined fluid is arbitrarily introduced into and discharged from the deformable portion 5, and the deformable portion 5 freely expands and contracts according to the change in the internal pressure. The fluid is supplied from the hand base 2 and guided to the deforming portion 5 through the finger 4. Here, the fluid may be a gas or a liquid.

FIG. 2 shows the wafer cassette 6 held by the hand 1. This wafer cassette 6 is
It has a main body 7 for accommodating a plurality of wafers (not shown), and a flange portion 8 formed on the opening edge of the main body 7. A space 9 for housing a wafer is formed in the main body 7 so that a plurality of wafers can be concentrically arranged and housed. A plurality of guide grooves 10 are formed on the inner wall of the main body 7 to engage with a part of the peripheral edge of the wafer to determine the attitude of the wafer. Then, the wafers are held by the grooves 10 while keeping a predetermined interval.

As the structure for holding the wafer by the main body 7, various general structures can be adopted. Further, in FIG. 2, the illustration of the wafer is omitted in order to simplify the drawing.

The flange portion 8 projects laterally of the main body 7, that is, in a direction perpendicular to the wafer arrangement direction. Further, the thickness of the flange portion 8 is set to be larger than the diameter of the fingers 4 and 4 of the hand 1. The flange portion 8 is formed with holes 11 for inserting fingers. These holes 11, 1
1 extend parallel to each other, and the side surface 12 of the flange portion 8,
12 has a perfect circular opening.

Next, the operation of the above-mentioned hand 1 will be described. First, the hand 1 brings the hand base 2 close to the wafer cassette 6 and faces the flange portion 8. Further, the fingers 4 and 4 are concentrically directed to the holes 11 and 11 of the flange portion 8, and the hand base 2 is brought closer to the flange 8,
As shown in FIG. 3, the fingers 4 and 4 are inserted into the holes 11 and 11. At this time, the deformed portions 5 and 5 of the fingers 4 and 4 are contracted.

Next, the deformed portions 5 and 5 expand and the holes 11 and
It deforms according to the shape of the peripheral portion of the outlet of 11. The deforming portions 5 and 5 are engaged with the wafer cassette 6,
Locks on hand 1. Then, the arm 3 moves while holding the wafer cassette 6, and the wafer cassette 6 is conveyed to a predetermined position (for example, a manufacturing apparatus in the next step).

When the wafer cassette 6 is released, the deformed portions 5 and 5 contract and the fingers 4 and 4 are pulled out from the holes 11 and 11. Here, the mutual diameter of each finger 4 and each hole 11 is
The wafer cassette 6 is set so as not to rattle when the finger 4 is inserted into the hole 11.

That is, in the hand 1 described above, the deformed portions 5 and 5 formed on the fingers 4 and 4 are expanded to expand the wafer cassette 6.
The wafer cassette 6 can be held without opening and closing the fingers 4 and 4. Therefore, the opening / closing mechanism is unnecessary, and dust generation due to the opening / closing mechanism can be prevented. Further, since the opening / closing mechanism can be omitted, the hand 1
Can be miniaturized.

Since the wafer cassette 6 is held by inserting the fingers 4 and 4 into the holes 11 and 11,
As long as 1 and 11 can be formed, the shape of the wafer cassette itself is not limited. Therefore, it is possible to hold wafer cassettes of various shapes.

In this embodiment, the deformed portions 5 and 5 are provided at the tips of the fingers 4 and 4, but the fingers 4 and 4 are made of a material that can expand and contract. Even if 4 is expanded, the same effect can be obtained.

If the manufacturing apparatus is provided with the fingers 4 and 4, the wafer cassette 6 can be held on the manufacturing apparatus. 4 to 6 show a second embodiment of the present invention,
Reference numeral 21 in FIG. 4 is a wafer cassette shape detection device (hereinafter referred to as a detection device). The detection device 21 is combined with the wafer transfer device 22 and detects the shape of the guide grooves 34 ... Of the wafer cassette 23 prior to the work of storing the wafers in the wafer cassette 23. Here, in this embodiment, as the wafer transfer device 22, various devices having a general hand can be adopted, and therefore the wafer transfer device 22 is schematically shown in FIG.

The detector 21 has a cassette elevator 24 and a detector 25. In the cassette elevator 24, a cassette stage (hereinafter referred to as a stage) 26 is attached to a main body 28 via lifting bodies 27, 27 (only one of which is shown). It can move up and down freely with the lifting bodies 27, 27. A circular hole 29 is formed in the center of the stage 26, and a column 30 vertically provided on the main body 28 passes through the circular hole 29.

A detector 25 is provided at the upper end of the column 30. The detection unit 25 has four optical distance sensors (hereinafter referred to as distance sensors) 31, ..., which are arranged radially at equal intervals. Each distance sensor 31
Emits detection light and receives reflected light of this detection light. Then, the distance sensor 31 detects the distance to the object based on the relationship between the detected light and the reflected light. As the distance sensor 31, various general ones can be used.

FIG. 5 shows the wafer cassette 23.
The wafer cassette 23 has concentric circular detection unit passage holes 32, 32 concentrically opened. Then, the wafer cassette 23 is placed sideways on the stage 26 of the inspection device 21 and moved up and down by the cassette elevator 24.

As the stage 26 moves up and down, as shown by an arrow A, the detecting section 25 enters the wafer cassette 23 through the detecting section passage hole 32. Each distance sensor 31 ...
As shown in FIG. 6, the inner wall 33 of the wafer cassette 23 is irradiated with the detection light and receives the reflected light. And stage 26
Is moved to scan the inner wall 33 of the wafer cassette 23 with the detection light, and based on the detection results of the distance sensors 31 ...
The shapes of the guide grooves 34 ... Of the wafer cassette 23 are detected.

The wafer transfer device 22 is driven based on the detection result of the detector 25, and the wafer is inserted into a predetermined guide groove. Also, when the wafer is unloaded, the detection result of the detection unit 25 is used, and the wafer transfer device 22 is driven based on the information on the shape of the wafer cassette 23. The movement path of the wafer is determined so that the wafer does not come into contact with the wafer cassette 23 as much as possible.

That is, in the detecting device 21 as described above, the shape of the wafer cassette 23 is detected prior to the insertion / unloading of the wafer. Therefore, after the shape of the wafer cassette 23 is recognized, the insertion / unloading of the wafer is performed. It can be performed. Therefore, the wafer can be prevented from rubbing against the wafer cassette 23, and dust generation can be reduced. As a result, highly reliable wafer transfer becomes possible.

If the detection unit passage hole 32 is provided, it is possible to detect the shapes of different types of wafer cassettes. Since it is not necessary to provide a sensor on the hand of the carrier, the carrier can be downsized.

In addition, the wafer cassette 2 is loaded and unloaded each time.
By detecting the shape of No. 3, the contact between the wafer and the wafer cassette 23 can be prevented regardless of the deterioration of the shape of the guide grooves 34.

By combining the detection unit 25 with the hand unit of the transfer device and moving the wafer cassette up and down, the same effect as that of this embodiment can be obtained. 7 to 10 show a third embodiment of the present invention, and the reference numeral 41 in each drawing shows a wafer cassette. This wafer cassette 41
Is a cassette part 43 for accommodating a plurality of wafers 42 ...
And a box 44 that covers the cassette portion 43, and buffer means 45 ... Is provided between the cassette portion 43 and the box 44. The box 44 is formed in a rectangular shape, and the upper portion 46 is open. The doorway 47 of the cassette unit 43 is exposed from the upper portion 46 of the box 44.

The buffering means 45 are arranged on the side and bottom of the box 44, and are connected to the side and bottom of the cassette 43. Then, the buffering means 45 ... Supports the cassette portion 43 in a floating state in the box 44. Here, as the buffering means 45, various general buffering means such as a coil spring can be adopted.

The wafer cassette 41 is placed on the pedestal 49 of the manufacturing apparatus 48 as shown in FIG. Box 44
Positioning holes 50 and 51 are provided at the bottom of the base, and the guides 51 and 51 and the magnet 52 projecting from the pedestal 49 are
It is inserted into these positioning holes 50 and 51. Guide 5
1, 51 receive the cassette part 43 between each other. Further, the magnet 52 attracts a magnetic plate 53 (for example, an iron plate) attached to the cassette unit 43.

That is, the wafer cassette 4 as described above
1, the cassette unit 43 is housed in the box 44, and the buffer unit 4 is provided between the cassette unit 43 and the box 44.
.. are provided, the vibration acting on the box 44 is absorbed by the buffer portion 45 and is attenuated before being transmitted to the cassette portion 43. Therefore, it is possible to prevent the vibration from being transmitted to the wafers stored in the cassette unit 43 without adding a vibration damping function to the transfer device or the manufacturing device. Further, it is possible to prevent the wafer from being damaged or dust.

Further, even when the operator directly conveys the wafer cassette 41, it is possible to prevent the vibration from being transmitted to the wafer. Furthermore, since it is not necessary to add a vibration isolation mechanism to the transport device, the transport device can be downsized.

Although not shown, the first box 44
If the finger insertion holes 11 of the embodiment are provided and the lengths and intervals of the fingers 4 and 4 are appropriately changed, the hand 1 of the first embodiment can be used.

In this embodiment, a coil spring or the like is used as the buffer portion 45.
Even if a viscous fluid is filled between the cassette portion 43 and the box 44, the vibration acting on the box 44 can be absorbed.

Further, if the upper portion 46 of the box 44 is sealed, the dustproof effect is further enhanced. 11 to 14 show a fourth embodiment of the present invention, and the reference numeral 61 in FIG. 11 denotes a wafer cassette. The wafer cassette 61 has a main body 63 for accommodating a plurality of wafers 62, and a wafer guide 64 for guiding and holding each wafer.

The wafer guide 64 is composed of an arcuate rod body, and is pivotally supported by the main body 63 at an intermediate portion in the longitudinal direction as shown in FIG. Further, as shown in FIG. 13, a pair of wafer guides 64 holds the wafer 62 in contact with the outer peripheral surface of the wafer 62.

The wafer cassette 6 includes a wafer guide 6
4 are formed to receive the elongated holes 65 ... As shown in FIG. 14, the wafer guide 64 has a trapezoidal cross section, and the other part of the wafer guide 64 freely engages with and disengages from the engagement groove 66 formed in the inner wall of the main body 63.

Next, the operation of the wafer cassette 61 will be described. First, as shown in FIG. 12, when the wafer 62 is not housed in the main body 63, the state of the wafer guide 64 is free, and the wafer guide 64 freely rotates about the pivot point 67. In this case, the front side portion of the wafer guide 64 (the portion near the opening 68 of the wafer cassette 61) 69 has entered the elongated hole 65, and the rear side portion 70 projects into the wafer cassette 61. There is.

On the other hand, when the wafer 62 is stored in the main body 63 as shown in FIG. 13, the wafer guide 64 is pushed by the wafer 62 as the wafer 62 enters the main body 63. Then, the wafer guide 64 guides the wafer 62 while rotating around the pivot point 67, and the portion 70 on the back side of the wafer guide 64 engages with the engagement groove 66.
At this time, the front side portion 69 of the wafer guide 64 projects into the main body 63.

As a result, each wafer 62 is sandwiched by the two wafer guides 64, 64 and held so as not to move easily. That is, in this wafer cassette 61, since it is held by the wafer guide 64, the vibration of the wafer 62 can be prevented. Therefore, it is possible to prevent the wafer 62 from being damaged or generating dust when the transfer device transfers the wafer cassette.

Further, even when the operator directly conveys the wafer cassette 61, it is possible to prevent the vibration from being transmitted to the wafer 62. Further, since it is not necessary to add a vibration isolation mechanism to the transfer device, the transfer device can be downsized.

In the present embodiment, the wafer guides 64 are used to prevent the vibration of the wafer. However, for example, the wafer guides 64 are omitted and a viscous fluid is applied to the engaging groove 65 of the main body 63. Even if filled, it is considered that the vibration of the wafer 62 can be similarly prevented. In this case, when the wafer 62 is unloaded, the viscous fluid is discharged from the engagement groove 65.

[0048]

As described above, the invention of claim 1 is
It is a wafer cassette provided with a cassette part for accommodating a plurality of wafers, a box for accommodating the cassette part, and a damping means for absorbing vibration applied to the box.

In the invention of claim 2, a plurality of wafers are accommodated in the main body, and when the wafers are pivotally supported by the main body and the wafers are accommodated in the main body, the wafers are rotated while being guided to be accommodated in the main body. And a wafer guide for holding the wafer.

According to the third aspect of the present invention, the wafer cassette hand is provided with a finger to be inserted into the wafer cassette, and a deformable portion which can be freely expanded and contracted and is deformed when expanded to engage with the wafer cassette. Is.

Further, the invention of claim 4 comprises a cassette elevator for raising and lowering the wafer cassette, and a detector for detecting the shape of the wafer cassette by entering the wafer cassette as the wafer cassette is raised and lowered. This is a wafer cassette shape detection device. Therefore, according to these inventions, there is an effect that dust generation can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing a carrying hand according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a wafer cassette according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a state where the wafer cassette is held by a hand.

FIG. 4 is a configuration diagram showing a shape detection device according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a wafer cassette according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a state of shape detection.

FIG. 7 is a configuration diagram showing a wafer cassette of a third embodiment of the present invention.

FIG. 8 is a plan view of a wafer cassette according to a third embodiment of the present invention.

FIG. 9 is a sectional view of a wafer cassette according to a third embodiment of the present invention.

FIG. 10 is a sectional view showing a state where the wafer cassette is placed in the manufacturing apparatus.

FIG. 11 is a perspective view showing a wafer cassette according to a fourth embodiment of the present invention.

FIG. 12 is a sectional view showing an empty state of a wafer cassette according to a fourth embodiment of the present invention.

FIG. 13 is a sectional view showing a state where wafers are stored in a wafer cassette according to a fourth embodiment of the present invention.

FIG. 14 is a sectional view showing a wafer guide and an engagement groove.

[Explanation of symbols]

1 ... Wafer cassette transport hand, 4, 4 ... Fingers, 5, 5
Deformation section, 6 ... Wafer cassette, 21 ... Wafer cassette shape detection device, 23 ... Wafer cassette, 24 ... Cassette elevator, 25 ... Detection section, 41 ... Wafer cassette, 4
2 ... Wafer, 43 ... Cassette part, 44 ... Box, 45
... buffer means, 61 ... wafer cassette, 62 ... wafer, 6
3 ... Main body, 64 ... Wafer guide.

Claims (4)

[Claims] 1. A wafer cassette comprising: a cassette unit for storing a plurality of wafers; a box for storing the cassette unit; and a cushioning unit for absorbing a vibration applied to the box. 2. A body for accommodating a plurality of wafers and a wafer accommodated in the body, which is pivotally supported by the body and rotates while guiding the wafer when the wafer is accommodated in the body. A wafer cassette having a wafer guide for holding. 3. A wafer cassette transfer hand comprising a finger to be inserted into a wafer cassette and a deformable portion which can be expanded and contracted and is deformed when expanded to engage with the wafer cassette. 4. A wafer cassette shape comprising: a cassette elevator for raising and lowering a wafer cassette; and a detection unit for entering the wafer cassette as the wafer cassette is raised and lowered and detecting the shape of the wafer cassette. Detection device.