JPH09219436A - Apparatus for pencil spacing adjustment in pencil holder of semiconductor manufacturing apparatus for holding a plurality of pencils - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pencil spacing adjusting apparatus capable of adjusting the spacing between respective pencils with a simple structure. SOLUTION: In a pencil holder of a semiconductor manufacturing apparatus for holding a plurality of pencils, a central pencil fixing part 20a3 of pencil fixing parts provided in said pencil holder for holding a plurality of pencils is fixed, and a first set of pencil fixing parts 20a1 , 20a5 disposed at the uppermost and lowermost symmetric positions with respect to the pencil fixing part 20a3 and a second set of pencil fixing parts 20a2 , 20a4 disposed inner than the first pencil fixing parts are connected respectively by a pair of ball screws respectively in order to be driven, and a synchronizing apparatus is used to rotate these first and second set of ball screws 21a1 , 21a2 ; 21b1 , 21b2 at the speed ratio of 2:1 and the pencil fixing parts 20a1 , 20a2 , 20a4 , 20a5 are constructed so that they are moved symmetrically in the upper and lower sides respectively, keeping parallel relation with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a pencil gap adjusting device in a pencil holder for holding a plurality of pencils in a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art A conventional semiconductor manufacturing apparatus for forming a semiconductor single crystal on a material wafer has a structure as shown in FIG. In the figure, reference numeral 1 is a semiconductor manufacturing apparatus that forms a dust-free chamber, and 2 is a robot that is a transfer apparatus, which is also used as a finger for transferring a wafer, which is provided at the tip of an arm 3 of the robot 2. The wafer 5 as a material is transferred and loaded from the carrier stage 6 to the wafer storage groove or shelf 8 provided on the support column inside the boat 7 by the pencil 4, and the boat 7 that has completed the loading of the wafer 5 is not shown. The material wafer 5 is raised by the elevating means and is housed in the reactor 9 to perform the required heat treatment. Further, 10 is a control device of this semiconductor manufacturing apparatus, 11 is its operation panel, which are placed outside the dust-free chamber. It should be noted that a plurality of (usually 100 to 150) grooves or shelves 8 for storing wafers are provided on the support column inside the boat 7 shown in FIG. 5, and a cassette (not shown here) of the carrier stage 6 is provided. Grooves or shelves in which the wafers 5 are normally stacked and stored in 25 stages are formed therein. Therefore, when the wafer 5 is transferred by the pencil 4 provided at the tip of the arm 3 of the robot 2 as described above, a plurality of wafers (five in this example) are transferred at once. Here, FIG. 6 shows a vertical cross-sectional front view of a conventional one in which five pencils 4 are integrally fixed. 4a
_{1 to} 4a ₅ are five pencils, respectively, and these pencils 4a _{1 to} 4a ₅ are provided with screws 14a ₁ at the respective tip portions of the pencil fixing portions 13a _{1 to} 13a ₅ constituting the pencil holder 13c.
And 14a _{2 and the} like. Incidentally, 13b is a pencil holder, and 3 is a robot arm.

[0003]

By the way, since the five pencil holders for holding the pencil and the pencil fixing portion of the conventional semiconductor manufacturing apparatus are constructed as described above, there are the following problems. It was (1) Since the pitch of the wafer transfer pencil was fixed, for example, the wafer set pitch was 6.35 mm.
Wafers in the cassette are installed at a wafer pitch of 5.0
When it is placed on a 0 mm boat, it is necessary to replace it with a pencil holder having such an interval, and the work is complicated. (2) Therefore, a method of vertically moving a plurality of pencils by a vertically moving mechanism to set a variable pitch is disclosed in Japanese Patent Laid-Open No. 4-167.
Although it has been proposed as shown in Japanese Patent No. 538, this method requires a guide and a rail for vertical movement of a plurality of pencils, and therefore has a drawback that the structure becomes complicated, and a simple configuration is desired. It was An object of the present invention is to provide a device for adjusting a pencil interval in a pencil holder for holding a plurality of pencils in a semiconductor manufacturing apparatus, which solves the above-mentioned problems (problems) of a conventional one.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a device for adjusting a pencil interval in a pencil holder for holding a plurality of pencils of a semiconductor manufacturing apparatus according to the present invention holds a plurality of pencils in a semiconductor manufacturing apparatus. A pencil holder for use in a pencil holder for holding a plurality of pencils, wherein a central pencil fixing portion of a pencil fixing portion is fixed, and the pencil fixing portion is vertically symmetrical with the pencil fixing portion. And a second set of pencil fixing parts arranged on the inner side of the outermost pencil fixing part are connected and driven by respective pairs of ball screws. Using a synchronizer that rotates a pair of ball screws at a rotation ratio of 2: 1, fix each pencil fixing part vertically with the pencil. It was configured to move in. Here, in the synchronizing device, a motor with a reducer is attached to one of the four ball screws, and the ball screws provided in the pencil fixing portions of the first set and the second set have a diameter of 1: 2. A small pulley and a large pulley having a ratio are provided, and the timing belt is wound around the two to four pulleys and driven. Also, the above pulleys and timing belts are
It is desirable that gears are formed on the surfaces that come into contact with each other and that they are in mesh with each other. Further, in the above synchronizing device, a photo sensor is provided on a predetermined pulley, and a pulse proportional to the rotation speed of the pulley is output from the gear of the pulley facing the photo sensor, and the output pulse and the motor for driving the pulley are set. It is desirable to control the spacing of the pencil clamps by controlling the speed of the motor as compared to the speed-responsive input pulse. A pencil spacing adjusting device in a pencil holder for holding a plurality of pencils of a semiconductor manufacturing apparatus of the present invention has a plurality of pencil fixing portions, which fixes a central pencil fixing portion and is vertically symmetrical with the central pencil fixing portion. Since the outer first set and the inner second set of pencil fixing parts are connected and driven by using 2 to 4 ball screws respectively, move the pencil fixing parts up and down in parallel. You can Further, as a synchronizing device, a ball screw provided in each of the pencil fixing portions of the first set and the second set is provided with a small pulley and a large pulley having a radius of 1: 2, and four pulleys are provided with a timing belt. Since the first and second pencil fixing portions and the second pair of pencil fixing portions have a rotation ratio of 2: 1, they can be moved up and down by a ratio of 2: 1. The distance between the fixed parts can be changed arbitrarily. Further, a gear is formed on the surfaces of the pulley and the timing belt that are in contact with each other so as not to slip due to rotation so that they mesh with each other, and a photo sensor is provided on any one of the four pulleys. And output a pulse proportional to the rotation speed of the pulley from the gear of the pulley facing each other,
Since the speed of the motor is controlled by comparing this output pulse with the input pulse corresponding to the set speed of the motor for driving the pulley, the interval between the pencil fixing parts can be controlled by the number of pulses.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to an embodiment shown in FIGS. FIG. 1 is an enlarged view of a main part of a pencil holder of the present invention, in which FIG. 1A is a front view of the main part when each pencil fixing part is in close contact with the center, and FIG. The side view of FIG. (A), the same figure (C) is a front view of the main parts when the intervals of the respective pencil fixing parts are widened, and the same figure (D) is the side view of FIG. FIG. 3 is a schematic plan view showing the relationship between a small pulley, a large pulley, and a timing belt. 6A to 6E, the same components as those in the conventional example are denoted by the same reference numerals as those in FIG. 6, and the description thereof will be omitted. 20a _{1 to} 20a ₅ are pencil fixing parts used in the present invention, among which the pencil fixing part 20a ₁
And 20a ₅ are respectively the upper and lower outermost first set of pencil fixing parts, and the pencil fixing parts 20a ₂ and 20a ₄ are arranged inside the pencil fixing parts 20a ₁ and 20a ₅ , respectively.
Set of pencil fixing portion, pencil fixing portion 20a ₃ is arranged in an intermediate position of each pencil fixing portions 20a _2, 20a _4, it assumed to be fixed. 21a ₁ and 21a ₂ are a pair of ball screws connected by being screwed so as to be orthogonal to the first set of pencil fixing parts 20a ₁ and 20a ₅ , and at the same time, 21b ₁ and 21b ₂ are respectively the second set of pencil fixing parts. 20a ₂ and 20a ₄ are a pair of ball screws that are screwed in at right angles. Each ball screw 21a ₁ , 21a ₂ ,
As shown in FIG. 2, 21b ₁ and 21b ₂ are formed with screws which are turned upside down from the center, and are arranged so that the center of each screw is located at the center of the pencil fixing portion 20a ₃ . In the figure (E), 22a ₁ and 22a ₂ are small pulleys,
22b ₁ and 22b ₂ are large pulleys, respectively. Small pulleys 22a ₁ and 22a ₂ are provided on the shafts of the ball screws 21a ₁ and 21a ₂ , and the ball screws 21b ₁ and 21b ₂ are provided.
Large pulleys 22b ₁ and 22b ₂ are provided on the shafts of the respective. A timing belt 23 has four pulleys 22a.
It is wound around the outer circumferences of ₁ , 22a ₂ , 22b ₁ and 22b ₂ . Further, 24 is a motor, 25 is a speed reducer, and the motor 2
4 is for rotating the ball screw 21a ₁ via the speed reducer 25. 26 is a rotation angle detector consisting of a photo sensor is disposed to face the large pulley 22b _1, detects the gear formed on the large pulley 22b ₁ on the circumference out the output pulse, the rotation angle of the large pulley I am trying to detect. Here, the diameter of the small pulleys 22a ₁ and 22a ₂ is
It is assumed that the diameter is, for example, 1/2 times the diameter of the large pulleys 22b ₁ and 22b ₂ , and that when the small pulleys 22a ₁ and 22a ₂ make two revolutions, the large pulleys 22b ₁ and 22b ₂ make one revolution. . Also, the ball screws 21a ₁ and 21a ₂
Are paired and screwed into the pencil fixing portions 20a ₁ and 20a ₅ , respectively, while the ball screws 21b ₁ and 21b ₂ are also paired and screwed into the pencil fixing portions 20a ₂ and 20a ₄ , respectively, as shown in FIG. Each pulley 22a ₁ , 22
a _2, 22b _1, 22b synchronized by ₂ and the timing belt 23 is rotated taken. Therefore, the pencil fixing portions 20a ₁ and 20a ₅ move up and down with a large stroke, and the pencil fixing portions 20a ₂ and 20a ₄ move up and down with a small stroke, and the pencil spacing is centered on the pencil fixing portion 20a ₃ at the intermediate position. It is possible to move up and down so as to have an equal pitch. In addition, in FIGS. 1A to 1D, the shapes of the respective pencil fixing portions are illustrated in a simplified manner. FIG. 2 is an enlarged cross-sectional view showing the outermost first set of pencil fixing parts taken out. In FIG.
The same reference numerals are given to the same configurations as, and the description thereof will be omitted. A bearing 27 is provided below the ball screw 21a ₁ . Pencil fixing parts 20a ₁ and 20a ₅
Although not shown, the pencils 4a ₁ and 4a ₅ connected to the pencil are fixed to the respective pencil fixing portions with screws. Here, when the ball screw 21a ₁ is rotated, the ball screw 21a ₁ is configured to be turned upside down from the center. Therefore, for example, when the ball screw 21a ₁ is rotated clockwise, the pencil fixing portion 20a ₁ is Move up,
The pencil fixing portion 20a ₅ is downwardly directed to the pencil fixing portion 20a.
a ₁ and is adapted to move the distance moved, and if you rotate the ball screw 21a ₁ counterclockwise, the pencil fixing portions 20a ₁ and 20a ₅ in the direction approaching to each other to respectively lower and upper To be done. The second set of pencil fixing portions 20a ₂ and 20a ₄ arranged inside also has the same structure as that of FIG. 2, and by rotating the ball screws 21b ₁ and 21b ₂ clockwise or counterclockwise, the pencils are fixed. The fixed portions 20a ₂ and 20a ₄ are moved symmetrically with respect to the central pencil fixed portion 20a ₃ in parallel with the upward and downward directions at an equal pitch. Here, the relationship between the outermost first set of pencil fixing parts and the second set of pencil fixing parts arranged inside thereof is shown in FIGS. 3 (A) to 3 (C). For the sake of simplicity, FIG. 3 shows, in a plan view, the relationship between only the pencil fixing portions 20a ₁ and 20a ₂ arranged above the pencil fixing portions of the first set and the second set. That is, FIG. 3A shows an enlarged plan view of the pencil fixing portion 20a ₁ , FIG. 3B shows an enlarged plan view of the pencil fixing portion 20a ₂ , and FIG. 3C shows the pencil fixing portions 20a ₁ and 20a ₂ . It is a top view showing the state where it piled up. The first set of pencil fixing portions 20a ₁ is formed so as to have concave portions t ₁ and t ₂ in the body portion as shown in FIG.
On the other hand, the convex portion t ₃ the second set of pencil fixing portion 20a ₂ of the inner projecting not overlap when superimposed at the location of recess t _1, t ₂ in FIG. As shown in FIG. (B) (A) , T ₄ are formed. Therefore, when the pencil fixing portions 20a ₁ and 20a ₂ are arranged so as to overlap each other as shown in FIG. 3C, the ball screws 21a ₁ and 21a are attached to the non-overlapping portions A ₁ , A ₂ , B ₁ and B _{2. 2} and 21b ₁ and 21b ₂ are paired and screwed in the orthogonal direction. Although not shown, the other (lower) pencil fixing part 20a ₅ of the outermost first set and the pencil fixing part 20a ₄ of the second set inside thereof are the same as the above-mentioned pencil fixing parts 20a ₁ and 20a ₂ , respectively. Each of the ball screws 21a ₂ ,
21b ₂ is screwed. In addition, the pulley, timing belt, and
The output of the photo sensor and the control mechanism using them are shown in FIG.
Shown in 4A is an enlarged plan view of the pulley 22b ₁ , FIG. 4B is an enlarged front view of the timing belt, and FIG.
Is a pulse waveform of the number of rotations of the pulley measured by a photo sensor, and FIG. 6D is a circuit configuration diagram of a control mechanism that controls the motor according to the number of pulses. In FIG.
Reference numeral 2b ₁ denotes a large pulley, and a gear is formed on the outer periphery thereof, and a timing belt 23 shown in FIG. 2B also has a gear meshing with the gear on the surface in contact with the large pulley 22b ₁ . . Although not shown, the pulleys 22a ₁ and 22a
It is assumed that a ₂ and 22 b ₂ also have gears formed on their outer circumferences and mesh with the gears of the timing belt 23 in the same manner as in FIG. The photo sensor 26 can measure the rotation speed of the large pulley 22b ₁ as a pulse, and its output waveform is as shown in FIG. FIG. 2D shows an example of a motor control circuit. In the figure, reference numeral 24 is a motor, and 26 is a photo sensor, which outputs a pulse number proportional to the speed of the motor 24.
Reference numeral 31 is a setter for inputting the set speed of the motor 24 by the number of pulses. A comparator 32 compares the number of measured pulses from the photo sensor with the number of set pulses from the setter 31.
33 is a motor driver. In the above configuration, the motor 24 is controlled as follows based on the number of measurement pulses of the photo sensor 26. That is, each of the pencil fixing portions 20a _{1 to} 20
Calculate the rotation speed of the ball screw 21a ₁ from the interval between a ₅
The number of pulses of the large pulley 22b ₁ corresponding to the number of rotations is calculated and input to the setter 31, the motor 24 is rotated, the number of pulses is observed by the photosensor 26, and the current number of pulses and the setter 31 When the numbers of pulses are compared by the comparator 32 and become equal, a stop signal of the motor 24 is transmitted to the motor driver 33 and the motor 24 is controlled so as to stop, so that the intervals between the pencil fixing portions 20a _{1 to} 20a ₅ are reduced. Can be changed arbitrarily. In the above configuration, the motor 24 installed on the shaft of the ball screw 21a ₁
Rotating the ball screw 21a ₁ and the small pulley 22a ₁ provided on the shaft also rotate. The small pulley 22a ₁ is provided with a timing belt 23, and the other pulleys 22a ₂ , 22b ₁ and 22b ₂ also rotate at the same time. At this time, the small pulleys 22a ₁ and 22
The ratio of the radius between a ₂ and the large pulleys 22b ₁ and 22b ₂ is 1: 2.
Since going on, the large pulley 22b ₁ and 22b ₂ while the small pulley 22a ₁ and 22a ₂ rotates twice will be one revolution. Therefore, each pulley 22a ₁ , 22a ₂ , 2
2b ₁ and 22b ₂ rotation speed and each pencil fixing part 20a ₁ ,
Since the vertical parallel distances of 20a ₂ , 20a ₄ and 20a ₅ are proportional to each other, the pencil fixing portions 20a _{1 to} 20a ₅ can be moved in parallel vertically at equal intervals. Equidistant Thus, for example, even if the distance between the shelves in the cassette is transferred to the wafer boat spacing 5.00mm at 6.35 mm, by the above driving method, the interval between the pencil fixing portions 20a ₁ through 20a ₅ The wafer can be transferred by moving in parallel with. With such a structure, by rotating each ball screw clockwise or counterclockwise, each pencil fixing portion can be moved up and down without using any other guide, rail, holding arm or the like. Further, all the radii of the pulleys used in the present embodiment are the same, and the lead of the ball screw provided in the pencil fixing portion paired inside and the lead of the ball screw provided in the pencil fixing portion paired outside Even if the ratio is 1: 2, the same effect as the above method can be obtained. In the present embodiment,
To prevent overhang, the motor is equipped with a speed reducer to rotate the ball screw.However, if a soft start, soft stop control or a geared motor with a large reduction ratio is used, the ball screw may rotate in reverse due to the load. Disappear.

[0006]

Since the device for adjusting the pencil gap in the pencil holder for holding a plurality of pencils of the semiconductor manufacturing apparatus of the present invention is constructed as described above, it has the following excellent effects. (1) The intervals between the pencils can be changed with a simple structure that does not use guides, rails, holding arms, or the like. (2) Fix the central pencil, and install a large pulley on the ball screw provided on the inner pair of the paired pencil fixing portions of the second set, and on the outer pair of the first pair of pencil fixing portions. The number of rotations of the ball screw provided with the small pulley is small because the small pulleys are provided on each ball screw and the timing belts are wound around each of them, and one of the small pulleys is provided with a motor with a speed reducer for driving. Since the small pulley and the large pulley rotate at a ratio of 2: 1 in synchronization with, it is possible to widen or narrow the intervals while keeping the intervals of the pencils the same. (3) Furthermore, the interval between the pencils can be controlled accurately by the number of pulses from the rotation speed of the pulley based on the detection result of the photo sensor.

[Brief description of drawings]

FIG. 1 (A) is a front view of a main part when each pencil fixing part is closely attached to the center and a pencil pitch is a small pitch, and FIG. 1 (B) is a side view of the same part. (C) is a front view of a main part when the intervals between the pencil fixing parts are widened and the pencil intervals are set to a large pitch, (D) is a side view of (C), and (E) is a small pulley. FIG. 3 is a schematic plan view showing a relationship between a large pulley and a timing belt.

FIG. 2 is an enlarged cross-sectional view of a pair of pencil fixing portions.

FIG. 3 (A) shows a pair of outermost pencil fixing parts 2.
0a _{1 is} an enlarged plan view, FIG. 2B is an enlarged plan view of a pair of pencil fixing portions 20a ₂ arranged inside thereof, and FIG. 2C is a plan view when both pencil fixing portions are stacked. is there.

4 (A) is an enlarged plan view of a pulley 22b ₁ , FIG. 4 (B) is an enlarged plan view of a timing belt, and FIG. 4 (C).
Shows the output pulse waveform accompanying the rotation of the pulley 22b ₁ detected by the photosensor, and FIG. 7D shows the circuit for controlling the motor 24 by the number of the pulses.

FIG. 5 is a front view showing the outline of the overall configuration of a semiconductor manufacturing apparatus to which the present invention and the conventional one are applied.

FIG. 6 is a vertical sectional front view showing a pencil mounting portion of a conventional robot arm.

[Explanation of symbols]

4a ₁ to 4A _5: Pencil 20a _1, 20a _5: first set of pencil fixing portion 20a _2, 20a _4: second pair of pencil fixing portion 20a _3: Central pencil fixing portion 21a _1, 21a _2: first set Ball screws 21b ₁ and 21b ₂ : second set of ball screws 22a ₁ and 22a ₂ : small pulleys 22b ₁ and 22b ₂ : large pulley 24: motor 25: speed reducer 26: photo sensor 27: bearing 31: setter 32 : Comparator 33: Motor driver

Claims (4)

[Claims] 1. A pencil holder for holding a plurality of pencils in a semiconductor manufacturing apparatus, wherein a central pencil fixing portion of a pencil fixing portion provided in the pencil holders for holding a plurality of pencils is fixed, and the pencil fixing portion is fixed. And a first set of pencil fixing parts arranged on the outermost side and a second set of pencil fixing parts arranged on the inner side of the outermost pencil fixing part are respectively connected by a pair of ball screws. The first and second ball screws of the first set and the second set are rotated at a rotation ratio of 2: 1 by using a synchronizing device, and each pencil fixing part is moved vertically and in parallel with the pencil. An apparatus for adjusting a pencil interval in a pencil holder for holding a plurality of pencils in a semiconductor manufacturing apparatus, characterized in that. 2. The synchronizer according to claim 1, wherein a motor with a speed reducer is attached to one of the four ball screws, and the ball screws provided in each of the first and second pencil fixing portions have a pair of diameters. 2. A pencil holder for holding a plurality of pencils in a semiconductor manufacturing apparatus according to claim 1, wherein a small pulley and a large pulley having a ratio of 2 are provided, and a timing belt is wound around the two to four pulleys for driving. Device for adjusting pencil spacing. 3. Each of the pulleys and the timing belt comprises:
3. A device for adjusting a pencil interval in a pencil holder for holding a plurality of pencils in a semiconductor manufacturing apparatus according to claim 2, wherein gears are formed on surfaces that come into contact with each other so as to mesh with each other. 4. In the synchronizer, a photo sensor is provided on a predetermined pulley, and a pulse proportional to the rotation speed of the pulley is output from the gear of the pulley facing the photo sensor. 4. A plurality of semiconductor manufacturing apparatus according to claim 1, wherein the interval between the pencil fixing portions is controlled by controlling the speed of the motor as compared with the input pulse corresponding to the set speed of the motor. A device for adjusting the pencil spacing in a pencil holder for holding pencils.