JP2882746B2 - Substrate transfer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate transfer apparatus for transferring a substrate such as a semiconductor wafer or a substrate for an optical disk, and more particularly to a technique for taking out a substrate from a cassette for storing substrates in multiple stages.

[0002]

2. Description of the Related Art The process of manufacturing a substrate such as a semiconductor wafer is divided into a plurality of processing steps such as photoresist coating and heat treatment, and the substrate is transferred between a cassette containing the substrate and each of the steps. . 2. Description of the Related Art Conventionally, a suction arm or the like provided with a suction device is used to take a substrate in and out of a cassette, and when taking out a substrate from the cassette, the suction arm is moved below the substrates stored in the cassette in multiple stages. Then, the lower surface of the substrate is suction-held by the suction arm, and is taken out from the cassette. However, since the lower surface of the substrate is directly suction-held by the suction arm or the like, there is a problem that traces of the suction portion and dust or the like adhering to the suction portion adhere to the lower surface of the substrate. Therefore, as a conventional substrate transfer device, for example, Japanese Utility Model 3-1
The device described in No. 8435 is known.

This substrate transfer device is composed of a roller-shaped pressing member provided at a tip of a pair of fixed arms, a roller-shaped pressing member provided at a tip of a movable arm, and the like. Is moved horizontally to a position directly below the substrate in the cassette, each arm is raised, and the end of the substrate is supported by three holding members of each arm. Then, the arm supporting the substrate is retracted and taken out of the cassette.

[0004]

However, in the above-described substrate transfer mechanism, an arm having a predetermined thickness longer than the size of the substrate is formed to support the end of the substrate. In some cases, there is a problem that the tip of the arm interferes with the substrate. Hereinafter, FIG.
0 and FIG. FIG. 10 (a)
Is a plan view showing the inside of the cassette C, and FIG.
FIG. 10A is a cross-sectional view taken along the line AA, and FIG. 11 is a diagram illustrating the operation of the conventional substrate transfer device.

In the cassette C, the space between the upper and lower substrates W is small in order to store as many substrates W as possible.
As shown in FIG. 0 (b), the substrate holding unit 100 on which the edge of the substrate W is placed supports the substrate W in a point contact state.
The tip is formed in a tapered shape inclined downward. On the other hand, in the initial stage before the substrate W is aligned, the substrates W are randomly stored in the cassette C, and
0 (a), the substrate support member 100 positions the orientation flat OF of the substrate W ₁ is a cassette C
May come to the position. In such a case, the cassette C
11B, the substrate W is not supported horizontally.
As shown in ( ₁₎ , the substrates W ₁ and W ₂ are tilted, and are held in a posture in which the substrates W ₁ and W ₂ are tilted forward on the opening 101 side where the substrate W is taken in and out.
As described above, when the arm 102 is caused to enter the horizontal direction between the substrates W ₁ and W ₂ held in the cassette in the forwardly inclined posture and the substrate W held horizontally, the distal end portion of the arm 102 is moved. there is a possibility of damaging the substrate W ₁ interferes with the front end portion of the substrate W _1. To avoid this, arm 102
Is lowered into the cassette C, the cassette C
Or give damage to the substrate W ₂ below in contact with the surface of the substrate W ₂ of the bottom in the back side, a problem particles are generated results of.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has as its object to provide a substrate transfer apparatus capable of taking out substrates stored in multiple stages in a cassette without interfering with an arm. And

[0007]

The present invention has the following configuration to achieve the above object. That is, in a substrate transport device that takes out the substrate from a cassette that stores substrates in multiple stages, and stores the substrate in the cassette,
An arm for supporting an end of the substrate, an elevating drive unit for elevating the arm, an advancing / retracting driving unit for advancing / retreating the arm, and the arm in the cassette
The arm is displaced by a small distance during the forward drive of
Raising displacement means for causing

[0008]

According to the present invention, the arm is driven forward by the forward / reverse drive means, and the arm is inserted into the cassette.
As a result, the arm is raised by a small distance in a horizontal posture by the ascending displacement means during the forward drive, so that the arm moves obliquely below the substrates stored in the cassette in a multi-stage manner. In a state where the arm has entered below the substrate, the arm is raised by the elevation drive means, and the substrate in the cassette is transferred onto the arm. Then, the arm on which the substrate is placed and held is moved backward by the forward / backward drive means, and the substrate is taken out of the cassette.

[0009]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. <First Embodiment> FIG. 1 is a perspective view showing a schematic configuration of a semiconductor manufacturing apparatus used by a substrate transfer apparatus according to a first embodiment of the present invention. This apparatus is an apparatus for performing various processes such as coating a resist on a semiconductor substrate (hereinafter, simply referred to as a “substrate”) W such as a silicon wafer. A storage part (hereinafter, referred to as an indexer) 1 and a substrate processing unit 2 for processing a substrate W
It is composed of

The indexer 1 comprises a plurality of cassettes C mounted in a row on a fixed base 3, and the cassettes C
And a substrate transfer device 4 for transferring the substrate W between the transfer position P and the transfer position P. In each cassette C, the substrates W can be stored in multiple stages.

As shown in the perspective view of FIG. 2 and the side view of FIG. 3, respectively, the substrate transporting device 4 is a Z-axis motor for lifting and lowering included in the lifting and lowering driving means of the present invention provided on the support table 10. 11 and an X-axis motor 12 for forward / backward movement included in forward / backward drive means.

The support table 10 is externally fitted to a pair of first guides 13 provided in parallel with the direction in which the cassettes C are arranged in parallel, and the first screw shaft 14 is driven to rotate by a Y-axis motor (not shown). Is screwed into. The support base 10 is configured to reciprocate along the direction in which the cassettes C are arranged side by side by driving a Y-axis motor (not shown), and to be able to stop at a position in front of a predetermined cassette C and at each of the aforementioned substrate transfer positions P. Have been.

A gate frame 15 is provided on the support base 10, and a pair of second guides 16 are provided upright on the support base 10 and the gate frame 15. An elevating support member 17 is externally fitted to the second guide 16, and a second screw shaft 18 is screwed to the elevating support member 17. The reversible Z-axis motor 11 described above is connected to the lower part of the second screw shaft 18 in an interlocking manner, so that the lifting support member 17 can be raised and lowered. In this embodiment, the Z-axis motor 1
Reference numeral 1 also has a function as a raising displacement means, and is controlled so as to raise the arm by a very small distance during the forward driving of the arm into the cassette C described later. The ascending distance during the forward drive of the arm is set according to the degree of forward inclination of the substrate W stored in the cassette C. For example, in this embodiment, the arm moves 240 mm toward the inside of the cassette C.
The Z-axis motor 11 is controlled so as to rise by 1 mm while moving forward.

A third guide 21 is provided on a lifting table 20 attached to the lifting support member 17 in a horizontal direction orthogonal to the direction in which the cassettes C are arranged, and a first pulley 22 is provided.
And the second pulley 23 are rotatably supported on the shaft.
An endless belt 24 is stretched over the first pulley 22 and the second pulley 23. Belt 24
The moving table 30 is mounted on the third guide 21. First pulley 2
The X-axis motor 12 capable of reversing the rotation is connected to the cassette 2 so that the movable table 30 can move forward and backward with respect to the cassette C.

A column 31 is erected on the movable table 30, and an arm 32 is cantilevered on the upper end of the column 31. As shown in FIG. 3, the arms 32 are formed at both ends in the X direction with a pair of stepped substrate support portions 33 and a pair of guide portions 34 for positioning the end surface of the substrate W, The end of the substrate W is supported by the pair of substrate support portions 33 and held horizontally between the pair of guide portions 34.

Next, the configuration of a control system of the substrate transfer device 4 will be described with reference to FIG. FIG. 4 is a block diagram showing a configuration of a control system of the substrate transfer device. Here,
Motor control in the X and Y directions will be described.

The operation unit 40 is constituted by a keyboard or the like, through which an operator inputs and sets information such as the type of substrate and the transfer conditions.

The CPU 41 stores a control program for the entire apparatus, for example, information on the scanning path of the substrate transfer apparatus 4 and the like. Further, during the forward drive of the arm 32 in the X direction, an amount of upward displacement for raising the arm 32 by a small distance in the Z direction is set.

The information input from the operation unit 40 is
X-axis and Z-axis motor controllers 42 and 43
Sent to X-axis, Z-axis motor controllers 42, 43
Is for controlling the driving of the X-axis and Z-axis motors 12 and 11 based on an instruction from the CPU 41.

Next, the operation of the substrate transfer device 4 will be described with reference to FIGS. Here, a case where the substrate W is taken out of the cassette C by the arm 32 will be described.

(1) First, when there is a start instruction from the operation unit 40, the CPU 41 gives a movement instruction to a Y-axis motor controller (not shown). As a result, the Y-axis motor is driven to rotate, and the support base 10 is moved in the Y direction, and is positioned in front of the predetermined cassette C.

(2) When the support base 10 is positioned in front of the predetermined cassette C, the CPU 41 next gives a movement instruction to the Z-axis motor controller 43, and the Z-axis motor 11
Is driven to rotate. Thus the elevation frame 20 is lifting in the Z direction, as shown in FIG. 5 (a), the high to the arm 32, opposite to the cassette C, and is located between substantially the desired substrate W ₂ and the substrate W ₁ Position

(3) With the arm 32 positioned, the CPU 41 gives a forward movement instruction to the X-axis motor controller 42 and the Z-axis motor controller 4
3 is given an instruction to move the arm 32 by a small distance in the Z direction. As a result, the arm 32
As shown in (b), it is raised by a small distance while being advanced to the cassette C side in a horizontal state. Then, the arm 32 enters from the gap between the substrate W ₁ and the substrate W _2, and the Z-axis motor 1 is moved in a state where the arm 32 is located immediately below the substrate W _2.
1 and the X-axis motor 12 are stopped.

(4) With the arm 32 positioned directly below the substrate W ₂ , the Z-axis motor 11 raises the arm 32 so that the substrate W ₂ in the cassette is picked up from below and transferred. The end of W ₂ is supported by the substrate support 33 of the arm 32. With the substrate W ₂ held horizontally on the arm 32, the X-axis motor 12 is driven to rotate backward and is retracted, so that the substrate W ₂ is taken out of the cassette C. The storage of the substrate W in the cassette C is performed in the reverse order.

<Second Embodiment> FIG. 6 is a plan view of a main part of a second embodiment, and FIG. 7 is a side view of FIG.
The apparatus is provided with a substrate detecting device for detecting a forward tilt state of the substrate W in the cassette C. In the figure, the portions denoted by the same reference numerals as those of the first embodiment described above,
And the like are the same as those of the first embodiment, and the description is omitted here.

The support arm 5 is formed on the base 3 of the indexer 1 in a U-shape so as to sandwich the cassette C so as to be movable up and down.
A light projecting optical sensor 51 is provided at one end of the support arm 50, and a light receiving optical sensor 52 is provided at the other end. The light projecting optical sensor 51 and the light receiving optical sensor 52 are opposed to each other via an opening 53 for taking in and out the substrate W of the cassette C and a window 54 on the back side, and are mounted horizontally. By measuring the light-shielding / light-transmitting timing based on the state of light reception by the light-receiving light sensor 52 with respect to the light projected through the light-projecting light sensor 51 while driving the support arm 50 up and down, the forward fall of the substrate W The optical sensor 55 is configured to detect the degree.
In other words, if the substrate W is in a horizontal state, the time of the light-shielding state is short, and the light-shielding time becomes longer as the degree of the forward fall of the substrate W increases. You can know.

Below the base 3, an elevating support member 58 attached to the support arm 50 via a support member 56,
A pair of upright fourth guides 57 is provided. The elevating support member 58 is externally fitted to the fourth guide 57, and a third screw shaft 59 is screwed to the elevating support member 58. A reversible z-axis motor 60 is connected to the lower part of the third screw shaft 59 in an interlocking manner so that the elevating support member 58 can be moved up and down. That is, the optical sensor 55 is configured to move in the parallel storage direction of the substrates W stored in the cassette C.

Next, the configuration of the control system of the second embodiment will be described with reference to FIG. FIG. 8 is a block diagram showing the configuration of the control system of the second embodiment. The CPU 61
By inputting a detection signal from the light-receiving optical sensor 52, the amount of forward tilt of each substrate W is calculated, and the amount of forward tilt of each substrate W is increased when the arm 32 is driven forward into the cassette C. This is for calculating the amount of displacement.

The RAM 62 stores the position information of the substrate W from the z-axis motor controller 63, which will be described later, in association with the amount of forward tilt of the substrate W in the position information.

When an instruction to detect the substrate W is input from the operation unit 40, the instruction information is sent to the optical sensors 51 and 52 via the CPU 61 and to the z-axis motor controller 63. The z-axis motor controller 63 is
This is for controlling driving of the z-axis motor 60 based on an instruction from the CPU 61. The z-axis motor 60 has a z-axis encoder 6 which is a rotary encoder for detecting a rotation angle.
4 is attached. z-axis motor controller 63
Detects the moving distance of the optical sensors 51 and 52 by counting the pulse signals from the z-axis encoder 64. The moving distance of the optical sensors 51 and 52 detected by the z-axis motor controller 63 is also given to the CPU 61.

The CPU 61 calculates the amount of forward tilting state of each substrate W in the cassette C from the moving distance of the optical sensors 51 and 52 and the light-shielding / light-transmitting timing signal sent from the light-receiving optical sensor 52. You. The calculated forward tilt state amount is temporarily stored in the RAM 62.

When the arm 32 is driven forward (see FIG. 5 (b)), the CPU 61 reads out the front falling state of the substrate W below the substrate W to be taken out from the RAM 62 and reads the front falling state amount from the amount of the front falling state. The amount of upward displacement of the arm 32 in the Z direction is calculated. That is, when the degree of the forward tilt of the lower substrate W is large, the amount of upward displacement is increased accordingly. The drive of the Z-axis motor 11 is controlled based on the calculated amount of displacement, and the substrate W is taken out from the cassette C in the same manner as in the first embodiment.

In the first embodiment, the CPU controls the upward displacement of the arm 32 when the arm 32 is driven forward. However, the present invention is not limited to this. Is also good. For example, as shown in FIG. 9, a pair of pins 7 protruding from both side surfaces of the movable table 70 are inserted into cam grooves 72 of a pair of guide plates 71 provided on both sides of the movable table 70.
3 is fitted and driven by a drive source (not shown) such as a belt drive.
The moving table 70 may be raised while moving forward.

[0034]

As is apparent from the above description, according to the substrate transfer apparatus of the present invention, even if the substrates in the cassette are stored in a forwardly inclined posture, the arm on which the substrates are placed is inserted into the cassette. Since it advances and enters while slightly ascending, interference between the substrate and the arm is avoided, and as a result, the substrate can be taken out without damaging the substrate and preventing generation of particles.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall schematic configuration of a semiconductor manufacturing apparatus using a substrate transfer device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the substrate transfer device.

FIG. 3 is a partially cutaway side view of the substrate transfer device.

FIG. 4 is a block diagram illustrating a configuration of a control system of the substrate transfer device.

FIG. 5 is a diagram illustrating the operation of the substrate transfer device.

FIG. 6 is a plan view showing a main part of a second embodiment.

FIG. 7 is a side view of FIG.

FIG. 8 is a block diagram illustrating a configuration of a control system of the second embodiment.

FIG. 9 is a perspective view showing a main part of another embodiment.

FIG. 10 is a diagram illustrating a state in which substrates are stored in a cassette.

FIG. 11 is a diagram illustrating an operation of a conventional substrate transfer device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Indexer 2 ... Substrate processing part 4 ... Substrate transfer apparatus 11 ... Z-axis motor (elevation drive means, ascending displacement means) 12 ... X-axis motor (forward / backward drive means) 32 ... Arm 40 ... Operating part 41 ... CPU C … Cassette W… Substrate

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kenji Fujita 322 Hashizushi Furukawacho, Fushimi-ku, Kyoto-shi, Kyoto Dainippon Screen Mfg. Co., Ltd. 322 Habushishi Furukawa-cho Dai Nippon Screen Manufacturing Co., Ltd. Inside the Rakusai Factory (56) References Hikaru 4-2037 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B65G 1 / 00-1/20 B65G 49/07 H01L 21/68

Claims (1)

(57) [Claims] 1. A substrate transfer apparatus for taking out a substrate from a cassette for storing substrates in multiple stages and storing the substrate in the cassette, an arm for supporting an end of the substrate, and a lifting drive means for raising and lowering the arm. Forward / backward drive means for moving the arm forward / backward; and the arm during forward drive of the arm into the cassette.
A substrate transfer device , comprising: an upward displacement means for upwardly displacing the system by a minute distance .