JPH07232802A - Substrate conveying device - Google Patents

Abstract

PURPOSE:To provide a substrate conveying device capable of extracting substrates stored in a cassette without interfering with an arm. CONSTITUTION:A lifting support member 17 is close-fitted externally to a second guide 16 installed erectedly on a support frame 10 and a gate frame 15 and screwed onto a second screw shaft 18, and a reversal Z-axis motor 11 is connected interlockingly to the lower side of the second screw shaft 18./ Also a third guide 21 and an endless belt 24 installed tensely on the first and second pulleys 22 and 23 connected interlockingly to a reversal X-axis motor 12 are arranged on a lifting table 20 for the lifting support member 17, and a moving table 30 is installed on the belt 24 and close-fitted externally to the third guide 21. Then an arm 32 is supported on the moving table 30 at one side through a column 31, and the arm 32 is raised slightly by the drive control of the X- and Z-axis motors 12 and 11 of a CPU during the forward driving of the arm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate transfer device 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 the substrate 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 process steps such as photoresist coating and heat treatment. The substrate is carried between a cassette containing the substrate and each step. . Conventionally, a suction arm or the like equipped with a suction device is used to load and unload a substrate into and from a cassette, and when the substrate is taken out from the cassette, this suction arm is moved below the substrates stored in multiple stages in the cassette. Then, the lower surface of the substrate is suction-held by this 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 or dust attached to the suction portion adheres to the lower surface of the substrate. Therefore, as a conventional substrate transfer apparatus, for example, the actual fairness 3-1
The device described in 8435 is known.

This substrate transfer apparatus is composed of a roller-shaped pressing member provided at the tips of a pair of fixed arms and a roller-shaped pressing member provided at the tips of movable arms. After horizontally advancing to just below the substrate in the cassette, each arm is raised, and the end portion of the substrate is supported by the three pressing members of each arm. Then, the arm supporting the substrate is retracted and taken out from the cassette.

[0004]

However, in the above-described substrate transfer mechanism, since the arm having a predetermined thickness longer than the size of the substrate is formed to support the end portion of the substrate, the substrate can be stored in the cassette. In some cases, there is a problem that the tip of the arm interferes with the substrate. Below, Figure 1
0, with reference to FIG. Figure 10 (a)
Is a plan view showing the inside of the cassette C, and FIG.
FIG. 10A is a sectional view taken along the line AA of FIG. 10A, and FIG. 11 is a diagram showing an operation of the conventional substrate transfer apparatus.

Since the cassette C accommodates as many substrates W as possible, the space between the upper and lower substrates W is narrow, and the cassette C shown in FIG.
As shown in 0 (b), the substrate holding unit 100 on which the end portion of the substrate W is placed supports the substrate W in a point contact state.
The tip is formed in a tapered shape with a downward inclination. On the other hand, in the initial stage before the substrates W are aligned, the substrates W are randomly stored in the cassette C.
As shown in 0 (a), the position of the orientation flat OF of the substrate W ₁ is the substrate supporting member 100 of the cassette C.
May come to the position of. In such a case, cassette C
The substrate W is not horizontally supported in the inside of FIG.
As shown in FIG. 5, 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 toward the opening 101 side where the substrate W is taken in and out.
As described above, when the arm 102 is horizontally moved between the substrates W ₁ and W ₂ held in a tilted posture in the cassette and the substrate W held horizontally, the tip 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, the arm 102
Lowering the entry position of cassette C into cassette C
There is a problem that the lower substrate W ₂ is in contact with the surface of the lower substrate W ₂ on the back side of the substrate and scratches the lower substrate W ₂ , or particles are generated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a substrate transfer device which can take out substrates stored in multiple stages in a cassette without interfering with the arms. And

[0007]

The present invention has the following constitution in order to achieve the above object. That is, in a substrate transfer device that takes out the substrates from a cassette that stores the substrates in multiple stages and stores the substrates in the cassette,
An arm that supports the end portion of the substrate, an elevating and lowering drive unit that elevates and lowers the arm, a forward and backward drive unit that advances and retracts the arm, and the arm while the arm is entering the cassette. And an ascending displacement means for ascending and displacement by a minute distance in a horizontal posture.

[0008]

According to the present invention, the arm is driven forward by the forward / backward drive means, and the arm is lifted in the horizontal posture by a minute distance while the arm is moved forward by the lifting and displacing means. It enters below the board while rising diagonally. With the arm entering below the substrate, the arm is raised by the elevating and lowering drive means, and the substrate in the cassette is transferred onto the arm. Then, the arm holding the substrate is retracted by the forward / backward drive means, and the substrate is taken out from the cassette.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. <First Embodiment> FIG. 1 is a perspective view showing a schematic structure 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 kinds of processing such as resist coating on a semiconductor substrate (hereinafter, simply referred to as “substrate”) W such as a silicon wafer, and is roughly classified into an unprocessed substrate W and a processed substrate W. A storage part (hereinafter referred to as an indexer) 1 and a substrate processing part 2 for processing a substrate W
It consists of and.

The indexer 1 includes a plurality of cassettes C mounted in a line 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. The substrates W can be stored in each cassette C in multiple stages.

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

The support base 10 is externally fitted to a pair of first guides 13 provided in parallel with the juxtaposed direction of the cassettes C, and is also driven by a first screw shaft 14 which is rotationally driven by a Y-axis motor (not shown). It is screwed to. The support base 10 is configured to reciprocate along the direction in which the cassettes C are arranged in parallel by driving a Y-axis motor (not shown), and can be stopped in front of a predetermined cassette C and at each of the substrate transfer positions P described above. Has been done.

A gate type 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 type 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 Z-axis motor 11 capable of forward and reverse movements is interlockingly connected to the lower portion of the second screw shaft 18 so that the elevation support member 17 can be elevated and lowered. Further, in this embodiment, the Z-axis motor 1
1 also has a function as an ascending / displacement means, and is controlled so as to elevate the arm by a minute distance during the forward drive of the arm into the cassette C described later. The ascending distance of the arm during forward drive is set according to the degree of forward tilt of the substrate W stored in the cassette C. For example, in the present embodiment, the arm is 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.

On the lift table 20 attached to the lift support member 17, a third guide 21 is provided in the horizontal direction orthogonal to the direction in which the cassettes C are arranged side by side, and the first pulley 22 is provided.
And a second pulley 23 are rotatably supported.
An endless belt 24 is stretched over the first pulley 22 and the second pulley 23. Belt 24
The movable table 30 is attached to the third guide 21, and the movable table 30 is externally fitted to the third guide 21. First pulley 2
The forward and reverse X-axis motor 12 described above is interlocked and connected to the cassette 2 so that the movable table 30 can be moved forward and backward with respect to the cassette C.

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

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

The operation unit 40 is composed of a keyboard or the like, and the operator inputs and sets information such as the type of the substrate and conveyance conditions through the operation unit 40.

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

Information input from the operation unit 40 is stored in the CPU.
X-axis and Z-axis motor controllers 42, 43 via 41
Sent to. X-axis and Z-axis motor controllers 42 and 43
Is for driving and controlling 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. The case where the substrate W is taken out from the cassette C by the arm 32 will be described here.

(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 rotationally driven, the support base 10 is moved in the Y direction, and it is positioned in front of the predetermined cassette C.

(2) When the support base 10 is positioned in front of a predetermined cassette C, the CPU 41 next gives a movement instruction to the Z-axis motor controller 43 to cause the Z-axis motor 11 to move.
Is driven to rotate. As a result, the elevating table 20 moves up and down in the Z direction, and as shown in FIG. 5A, the arm 32 faces the cassette C and is positioned substantially between the desired substrates W ₂ and 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
A movement instruction for raising the arm 32 in the Z direction by a minute distance is given to 3. As a result, the arm 32 is
As shown in (b), while being advanced to the cassette C side in the horizontal state, it is raised by a minute distance. Then, the arm 32 enters through the gap between the substrate W ₁ and the substrate W _2, and the Z-axis motor 1 is positioned with the arm 32 positioned directly 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 to pick up the substrate W ₂ in the cassette and transfer the substrate W ₂ from below. The end portion of W ₂ is supported by the substrate support portion 33 of the arm 32. With the substrate W ₂ held horizontally on the arm 32, the substrate W ₂ is taken out from the cassette C by driving the X-axis motor 12 to rotate in the reverse direction and retract the substrate. The substrate W is stored in the cassette C in the reverse order of the above.

<Second Embodiment> FIG. 6 is a plan view of an essential part of the second embodiment, and FIG. 7 is a side view of FIG.
This is provided with a substrate detection device that detects the forward tilted state of the substrate W in the cassette C. In the figure, the parts indicated by the same reference numerals as the above-described first embodiment device, and the substrate transfer device 4
The other parts have the same configuration as the first embodiment device, and therefore the description thereof is omitted here.

On the base 3 of the indexer 1, a support arm 5 is formed in a U-shape so as to sandwich the cassette C and is movable up and down.
0 is provided, a light projecting optical sensor 51 is provided at one end of the support arm 50, and a light receiving photosensor 52 is provided at the other end. The light projecting optical sensor 51 and the light receiving optical sensor 52 are mounted horizontally, facing each other through an opening 53 for loading and unloading the substrate W of the cassette C and a window 54 on the back side. While the support arm 50 is being driven up and down, the timing of light blocking and light transmission is measured based on the light receiving state of the light receiving optical sensor 52 with respect to the light projected through the light projecting optical sensor 51. The optical sensor 55 is configured to detect the degree.
That is, if the substrate W is in the horizontal state, the time in the light-shielded state is short, and the light-shielding time becomes longer as the degree of the front-tilt of the substrate W increases. I can know.

Below the base 3, an elevating and lowering support member 58 attached to the support arm 50 through a support member 56,
A pair of upright fourth guides 57 is provided. An 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 z-axis motor 60 capable of reversing the forward direction and the reverse direction is interlockingly connected to the lower portion of the third screw shaft 59 so that the elevating and lowering 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 device will be described with reference to FIG. FIG. 8 is a block diagram showing the configuration of the control system of the second embodiment device. The CPU 61
By inputting the detection signal from the light-receiving optical sensor 52, the forward tilt state amount of each substrate W is calculated, and the forward tilt state amount of each substrate W is raised from the forward tilt state amount into the cassette C during forward drive. The amount of displacement is calculated.

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

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 the z-axis motor controller 63. The z-axis motor controller 63 is
This is for driving and controlling the z-axis motor 60 based on an instruction from the CPU 61. The z-axis motor 60 includes 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 movement distances of the optical sensors 51 and 52 detected by the z-axis motor controller 63 are 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 distances of the optical sensors 51 and 52 and the timing signals of light shielding and light transmission sent from the light receiving optical sensor 52. It The calculated amount of forward leaning state is temporarily stored in the RAM 62.

When the arm 32 is driven forward (see FIG. 5B), the CPU 61 reads from the RAM 62 the forward tilt state of the substrate W below the substrate W to be taken out, and from the forward tilt state amount, The amount of upward displacement of the arm 32 in the Z direction is calculated. That is, when the degree of forward tilt of the lower substrate W is high, the amount of upward displacement is increased accordingly. Then, the Z-axis motor 11 is drive-controlled based on the calculated amount of ascending 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 described above, the CPU controls the upward displacement of the arm 32 during forward drive, but the present invention is not limited to this, and as a modification thereof, a cam mechanism is provided in parallel in the X-axis direction. Good. For example, as shown in FIG. 9, in the cam grooves 72 of the pair of guide plates 71 provided on both sides of the moving table 70, the pair of pins 7 projectingly provided on both side surfaces of the moving table 70.
3 is fitted, and by a drive source such as a belt drive (not shown),
Alternatively, the moving table 70 may be raised while being moved forward.

[0034]

As is apparent from the above description, according to the substrate transfer apparatus of the present invention, even if the substrate in the cassette is stored in a forwardly inclined posture, the arm for mounting the substrate is placed in the cassette. Since it moves forward while slightly moving upward, the 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 the generation of particles.

[Brief description of drawings]

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

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

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

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

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

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

FIG. 7 is a side view of FIG.

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

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

FIG. 10 is a diagram showing a substrate storage state in a cassette.

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

[Explanation of symbols]

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

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenji Fujita, Fukumi-ku, Kyoto City, Kyoto Prefecture 322 Furukawa-cho, Futami-cho, Japan Rakusai Factory, Dainippon Screen Mfg. Co., Ltd. (72) Yoshiji Oka, Hatsushi-shi, Fushimi-ku, Kyoto 322 Furukawacho Dainippon Screen Mfg. Co., Ltd. Rakusai Factory

Claims (1)

[Claims] 1. A substrate transfer device for taking out the substrates from a cassette for accommodating the substrates in multiple stages and for accommodating the substrates in the cassette, and an arm for supporting an end portion of the substrate, and an elevating and lowering driving means for elevating the arm. And forward and backward drive means for moving the arm forward and backward, and ascending and displacing means for upwardly displacing the arm in a horizontal posture by a minute distance while the arm is entering the cassette. A substrate transfer device.