JPH1041370A - Variable pitch wafer transfer hand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the change of the vertical pitch of wafers mounted on fingers in a simple structure, by contacting driven nodes of lift fingers to eccentric cams to set the cam strokes to the product of the pitch difference by the number of steps of the fingers. SOLUTION: The wafer transfer hand functions as follows. Driven nodes J1 -J4 of lift fingers F1 -F4 , except a reference finger F0 contact to eccentric camps C1 -C4 due to self weights. The vertical pitch of wafers is changed from a standard pitch P1 to a narrow pitch P2 and the wafers are transferred at once. The cam strokes e1 -e4 are set to the product of the pitch difference d to be changed by the number of steps of the fingers F1 -F4 . The cams C1 -C4 are rotated to move the finger F1 -F4 up and down to change the vertical pitch of the wafers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable-pitch wafer transfer hand in a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art In a semiconductor manufacturing apparatus, a carrier stage apparatus is used to carry a wafer W into the apparatus. In this carrier stage device, as shown in FIG. 11, a plurality of carrier stands 53 are mounted on a carrier column 51 via a carrier table 52 at equal intervals in the circumferential direction, and a large number of wafers W are horizontally mounted. The wafer carrier 54 housed in the state is placed on the carrier stand 53, and the carrier column 51 is rotated by a set angle by a driving means, and the wafer transfer mounted on the distal end of the arm 55 at the distal end of the articulated robot R is moved. The configuration is such that the wafer W in the wafer carrier 54 is taken out by the mounting hand 56 and transferred to the wafer boat 57 by the operation of the articulated robot R. At this time, in order to improve the throughput, a plurality of (usually five) wafers W are simultaneously placed at the standard pitch P ₁ (6.3).
5 mm) from the wafer carrier 54 side, the narrow pitch P
₂ (4.76mm or 5.2mm) wafer boat 5
The method of transferring to the 7 side is performed. For this purpose, it is necessary to provide the wafer transfer hand 56 with a mechanism for changing the vertical pitch of the plurality of wafers W.

Conventionally, as this kind of wafer transfer hand,
There is one described in JP-A-7-37966.
The technology disclosed in this publication is described in “Pitch Conversion Plate (5)
A drive source (8) includes a wafer holding plate mounting block (4) on one surface (9A) or the other surface (9B) of the variable groove (9).
2. A wafer variable pitch wafer holder characterized in that it can cope with two types of wafer pitches by pressing. ". However, the technique described in this publication uses a pneumatic cylinder as a driving source for changing the pitch of a wafer, and therefore has a disadvantage that the impact during operation is large and the stability is lacking. Furthermore, semiconductors are usually manufactured in clean rooms. That is, since this type of wafer transfer hand is used in a clean room, it is necessary to reduce the impact.

[0004] Another technique is disclosed in Japanese Patent Laid-Open No. 7-106.
The technology described in Japanese Patent Publication No. 403 is disclosed. In this technique, an arm is attached to each movable body of a ball screw which is threaded in a direction opposite to each other, and the movable body is steplessly rotated in the opposite direction by the same amount by rotating the ball screw by a predetermined amount. It is a configuration of moving. However, in this method, since a ball screw is used, the device becomes complicated and large. Moreover, it is expensive. Further, the pitch of the wafers on the wafer boat 57 side is limited, and in most cases, only the two types of pitches (4.76 mm or 5.2 mm) need to be supported.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention has a simple structure in which a vertical pitch of each wafer placed on each finger is reduced in a hand for transferring a plurality of wafers at a time. The task is to be able to make changes in the

[0006]

In order to solve this problem, the present invention adopts a method in which a wafer is mounted on a plurality of fingers arranged in multiple stages, and among these fingers, other than the reference finger. The lifting fingers can be individually raised and lowered in a cantilevered state with respect to the frame, and each of the follower sections of the lifting fingers is in contact with the eccentric cam by its own weight, and is narrow from the standard pitch wafer carrier side. When transferring wafers to the wafer boat side of the pitch, the pitch in the vertical direction of the wafers placed on the plurality of fingers is changed to change the pitch of the plurality of wafers at once. A mounting hand, wherein each cam stroke of the eccentric cam is a value obtained by multiplying a difference in pitch to be changed by each step number of the lifting finger, and the eccentric cam is rotated. By raising and lowering the lifting finger is that you can change the vertical pitch of the wafer other than that for the wafer reference finger.

The vertical pitch of each elevating finger with respect to the reference finger of the variable-pitch wafer transfer hand is
The standard pitch is set in advance. Therefore, the pitch of the plurality of wafers placed on each finger is set to a standard pitch. The variable-pitch wafer transfer hand is moved to the standard-pitch wafer carrier side, and each wafer on the wafer carrier side is mounted on the reference finger and each elevating finger of the variable-pitch wafer transfer hand and taken out. When the eccentric cam is rotated by 180 ° in this state, each elevating finger is raised by the operation of each eccentric cam, and the vertical pitch of each elevating finger with respect to the reference finger is changed to a narrow pitch. That is, the pitch of each wafer placed on each finger is changed to a narrow pitch. The variable-pitch wafer transfer hand is moved to the narrow-pitch wafer boat side to store each wafer. Thereafter, the eccentric cam is rotated 180 ° in the opposite direction to lower each lifting finger to set a standard pitch.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to examples. Figure 1 is a plan view of the variable pitch wafer transfer hand according to the present invention, FIG 2 is also a side view, FIG. 3 is a X ₁ -X ₁ cross-sectional view of FIG. In this embodiment, the vertical pitch of the five wafers is set to the standard pitch P ₁ (6.35 mm).
Described as the wafer transfer hand for changing to one (4.76 mm) of the narrow pitch P ₂ from. 1 to 3
As shown in the frame 1 of the wafer transfer hand according to the present invention, a pair of frame 3a erected on the upper surface of the base 2 and the base 2, consists 3b and the reference bracket B ₀ Metropolitan . The pair of frames 3a and 3b have an inverted U-shape,
In addition, the base 2 is divided into two substantially at the center in the longitudinal direction. Reference bracket B ₀ is fixedly provided straddling frame body 3a, 3b top surface of. A rectangular and plate-shaped reference finger F ₀ is attached to the reference bracket B ₀ in a form protruding forward from the frame 1.
Below the reference finger F _0, the reference finger F ₀ first to fourth lifting fingers forming a substantially the same shape as the F ₁ to F ₄ are in this order, moreover reference finger F ₀
It is arranged in a shape that substantially overlaps with. As described below,
Reference finger F ₀ and each lifting finger F ₁ to F
₄ are those whose base ends are the reference bracket B ₀ and the first to
It is fixed to the fourth lifting brackets B _{1 to} B ₄ and is supported in a cantilever state. The cantilevered portion of each finger F ₀ to F ₄ is not a wafer placing portion, the circular groove 10 corresponding to the circular wafer W is provided in these portions. The reference finger F ₀ and each lifting finger F _{1 1}
Vertical pitch of the wafers W placed on the F ₄ is preset to the standard pitch P ₁ (6.35mm).

[0009] As shown in FIGS. 1 and 4, a substantially central portion of the frame 1, along the direction perpendicular to the longitudinal direction of the reference finger F ₀ described above, the cam shaft 4 is disposed. The vicinity of both ends of the camshaft 4 is supported by slide bearings 5 mounted on a pair of frames 3a and 3b constituting the frame 1, respectively. As described above, since the set of frames 3a and 3b is divided into two, the camshaft 4 can be removed by removing one of the frames 3a and 3b from the base 2. A gear 6 is attached to an end of the camshaft 4 protruding from the frame 3a on one side. Similarly, a dog 7 is attached to an end of the camshaft 4 projecting from the frame 3b on the other side. Also, this camshaft 4
From one end to the other end in the axial direction,
Fourth eccentric cam C ₁ -C ₄ a is mounted so as to be integrated with this order. A geared motor M is disposed on the upper surface of the base 2 inside the pair of frames 3a, 3b along the axial direction of the camshaft 4. A gear 8 is mounted on the geared motor M, and meshes with the gear 6 of the camshaft 4 described above. By operating the geared motor M, the camshaft 4 rotates in a predetermined direction.

As shown in FIGS. 1 to 3, a proximity switch 9 is provided in a vertical direction opposite to a dog 7 attached to the end of the camshaft 4. When the camshaft 4 is rotated by operating the geared motor M, the dog 7 is simultaneously rotated about the axis of the camshaft 4. When the dog 7 is detected by any of the proximity switches 9, the operation of the geared motor M stops. That is,
The angle at which the camshaft 4 rotates is approximately 180 °. 1 to 3, reference numeral 11 denotes a switch bracket for holding each proximity switch 9.

The configuration of the _first to _fourth lifting fingers F _{1 to} F ₄ will be described with reference to FIGS. As shown in FIG. 6, each of the lifting brackets B _{1 to} B _1
4 is substantially lying they form a "L" shape, the base end portion of each lifting finger F ₁ to F ₄ are attached to their horizontal step portion 12 in a front view. The support portions 13 provided in a direction perpendicular to the step portions 12 are individually attached to the guide rails G _{1 to} G ₄ . As shown in FIG. 4, these four guide rails G _{1 to} G ₄ are provided on the inner side of the front part of a pair of frames 3 a and 3 b constituting the frame 1 by two in the vertical direction. Installed in parallel. As shown in FIGS. 3 and 5, each lift finger F ₁ to F ₄ is disposed turned multistage so each other do not interfere. As described above, the first to fourth lifting fingers F _{1 to} F ₄ are respectively connected to the lifting brackets B _{1 to} B
Is attached in the state of cantilever ₄ through the respective guide rails G ₁ ~G _4.

[0012] Figure 4 to as shown in FIG. 7, the lift bracket B ₁ each of the rear follower portion of .about.B ₄ J ₁
Through J ₄ are provided, each of the lower surface is in contact with the eccentric cam C ₁ -C _4. Each of the follower sections J _{1 to} J ₄
The eccentric cams C _{1 to} C _{4 on} the camshaft 4 are arranged alternately according to the mounting positions. Therefore, the follower portions J ₁ through J ₄ What happened without the interference, lifting the finger F ₁ to F ₄ of the first to fourth that are fixed to each lift bracket B ₁ .about.B ₄ is individually lifting It is possible. Each follower portions J ₁ through J ₄ by respective own weight, the eccentric cam C ₁
It is pressed against the respective cam surfaces of the -C _4. Furthermore, each follower joint J
The upper part of the ₁ through J ₄ have are provided spring support hole H ₁ to H _4, these spring support hole H ₁ ~
Compression springs S _{1 to} S ₄ are respectively mounted on H ₄ . The upper ends of the compression springs S _{1 to} S ₄ are regulated by a reference bracket B ₀ constituting the frame 1. Therefore, the follower portions J ₁ through J ₄ is by the urging force of the compression spring S ₁ to S ₄ described above and its own weight, and is more strongly pressed against the respective cam surface of the eccentric cam C ₁ -C ₄ .

Referring to FIG. 8, reference finger F ₀
And the vertical pitch of the wafer W placed on each lifting finger F ₁ to F _4, a description will be given of the principle of changing from the standard pitch P ₁ in the pitch P _2. Since the reference finger F ₀ of the uppermost stage is fixed, in the vertical direction of each lifting finger F ₁ to F ₄ (or each lifting finger F ₁ to F ₄ are each lift bracket B ₁ .about.B ₄ attached) Change the pitch. To change the pitch of the reference finger F first for ₀ lifting the finger F _1, the difference in the elevating finger F ₁ and the standard pitch P ₁ and a narrow pitch P ₂ d (i.e., d = P ₁ -P ₂ ) Only need to be raised. Then, in order to change the second pitch of the lifting finger F ₂ with respect to the reference finger F ₀ is, if raising the elevating finger F ₁ by twice the difference d between the standard pitch P ₁ and a narrow pitch P ₂ Good. Similarly, in order to change the third pitch of the lifting finger F ₃ of the reference finger F ₀ is the finger F ₃ descending該昇only 3 times the difference d between the standard pitch P ₁ and a narrow pitch P _2, also ,
Fourth lifting finger F _{4 with} respect to reference finger F ₀
In order to change the pitch of the lifting finger F ₄
Should be increased by four times the difference d between the standard pitch P ₁ and the narrow pitch P ₂ . Standard pitch P ₁ and the narrow pitch P described above
_The number multiplied by the difference d from ₂ is the number of stages of the _first to _fourth lifting fingers F1 to F4.

The camshaft 4 will be described. As shown in FIGS. 9 and 10, each of the eccentric cams C ₁ to C _{1 is} attached to the cam shaft 4 from one end of the cam shaft 4.
₄ are installed. Each eccentric amount of the eccentric cam C ₁ -C _4, is set as follows. The difference d of the pitch the eccentricity of the eccentric cam C ₁ with respect to the axial center 4a of the cam shaft 4, and the
0.5 times. The cam shaft 4 to 180 ° rotated by the geared motor M, the cam stroke e ₁ of the eccentric cam C ₁ is twice the eccentricity described above, i.e., is d. Similarly, the eccentric amount of the eccentric cam C _2, by setting the difference d of the pitch described above, the cam stroke e ₂ is twice of the above-mentioned eccentricity, i.e., 2d. Similarly, the eccentric amount of the eccentric cam C _3, is set to 1.5 times the difference d of the pitch described above, the cam stroke e ₃ is twice the above-mentioned eccentricity, i.e., 3d. Similarly, if the eccentric amount of the eccentric cam C ₄ is set to twice the pitch difference d, the cam stroke e ₄ becomes twice the eccentric amount, ie, 4 times.
d. As described above, each of the cam stroke e ₁ to e ₄ of the eccentric cam C ₁ -C ₄ is obtained by multiplying the difference d of the pitch to be changed and the number of stages of lifting the finger F ₁ to F ₄ values, i.e. d , 2d, 3d, and 4d.

When the camshaft 4 is rotated, the eccentric cam C
₁ -C ₄ rotates, lift bracket B ₁ .about.B respective follower portions J ₁ through J ₄ of ₄ rises by the cam stroke e ₁ to e ₄ of the eccentric cam C ₁ -C _4. As described above, the eccentric cam C
Since ₁ Each cam stroke e ₁ to e ₄ of -C ₄ are each d, 2d, 3d, 4d, reference finger F ₀
First lift finger F ₁ immediately below the rises by the height d. Similarly, the _second to fourth lifting fingers F ₂ to F disposed below the first lifting finger F _1.
4 rises by 2d, 3d, 4d respectively. As a result, each of the _first to _fourth lifting fingers F _{1 to} F ₄ has a narrow pitch P ₂ (4.76 mm) with respect to the reference finger F ₀ .
Is set to That is, the pitch of the wafer W placed on each of the fingers F _{0 to} F ₄ is narrower than the pitch P ₂ (4.76).
mm). To set the lifting fingers F _{1 to} F ₄ to the standard pitch P ₁ (6.35 mm) again, the camshaft 4 may be rotated 180 ° in the opposite direction.

As described above, the camshaft 4 can be removed by removing one of the pair of frames 3a and 3b. Therefore, by replacing the camshaft 4, a single pitch-variable wafer transfer hand can be used with a narrow pitch other than 4.76 mm (for example, 5.2 mm).
Is also possible.

[0017]

In the variable-pitch wafer transfer hand according to the present invention, a plurality of lifting fingers are arranged in multiple stages below the reference finger, and each driven joint provided at the rear of each lifting finger is provided. Each is in contact with the eccentric cam. In addition, each cam stroke of the eccentric cam is a value obtained by multiplying the difference in pitch to be changed by the number of steps of the lifting finger. Therefore, by rotating these eccentric cams, the vertical pitch of each elevating finger with respect to the reference finger can be changed. That is, the pitch of each wafer of the lifting fingers with respect to the wafer of the reference finger can be changed. Further, each of the above-described driven joint portions is constantly urged downward by its own weight and a compression spring. Therefore, each lifting finger can be raised and lowered more reliably. The mechanism for raising and lowering each lifting finger simply rotates the eccentric cam, and can be realized at low cost. Further, by replacing the eccentric cam, it is possible to cope with a pitch having a different size.

[Brief description of the drawings]

FIG. 1 is a plan view of a variable-pitch wafer transfer hand according to the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is a sectional view taken along line X ₁ -X ₁ of FIG. 2;

FIG. 4 is a sectional view taken along line X ₂ -X ₂ of FIG. 2;

FIG. 5 is a sectional view taken along line X ₃ -X ₃ of FIG. 4;

6 is an exploded view showing the mounting state of each lift bracket B ₁ .about.B ₄ and the guide rail G ₁ ~G _4.

FIG. 7 is a sectional view taken along line X ₄ -X ₄ of FIG. 4;

FIG. 8 shows each lifting finger F on which a wafer W is mounted.
The pitch of _{1 ~F 4,} narrow pitch P ₂ from the standard pitch P ₁
It is explanatory drawing for changing into.

FIG. 9 is a front view of the camshaft 4;

FIG. 10 is a sectional view taken along line X ₅ -X ₅ of FIG. 9;

[11] The wafer W from the standard pitch wafer carrier 54 side of P _1, is a diagram showing a state of transferring the wafer boat 57 side of the narrow pitch P _2.

[Explanation of symbols]

C ₁ -C _4: eccentric cam d: the difference between the pitch e ₁ to e _4: cam stroke F _0: reference finger F ₁ to F _4: lifting finger J ₁ through J _4: follower portion P _1: standard pitch P ₂ : Narrow pitch S _{1 to} S ₄ : Compression spring W: Wafer 1: Frame 4: Cam shaft 54: Wafer carrier 57: Wafer boat

Claims (4)

[Claims] 1. A wafer is mounted on a plurality of fingers arranged in multiple stages, and among these fingers, lifting fingers other than a reference finger can be individually raised and lowered in a cantilever state with respect to a frame. At the same time, each follower section of the lifting finger is in contact with the eccentric cam by its own weight, and when transferring wafers from the standard pitch wafer carrier side to the narrow pitch wafer boat side, the plurality of A variable-pitch wafer transfer hand for transferring a plurality of wafers at a time by changing a vertical pitch of a wafer mounted on a finger, wherein each cam stroke of the eccentric cam is changed. A value obtained by multiplying the pitch difference by the number of stages of the lifting fingers is obtained, and the eccentric cam is rotated to raise and lower each of the lifting fingers. Variable pitch wafer transfer hand, characterized in that the changeable vertical pitch of the wafer other than that for. 2. A compression spring is mounted between each of the follower members of the lifting finger and the frame, and each of the follower members is constantly biased by an eccentric cam. The variable-pitch wafer transfer hand according to claim 1. 3. The variable-pitch wafer transfer hand according to claim 1, wherein each of the eccentric cams is integrally attached to a camshaft. 4. The variable-pitch wafer transfer hand according to claim 3, wherein the camshaft is replaceable.