JPH09306983A - Substrate carriage, substrate drawing and housing apparatus provided with the same and substrate transfer apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the deviation range of substrates by forming guides for arranging the substrates at first positioning parts, positioning the substrates near the center at second position parts and positioning the centers of the substrates at the bottoms of the second positioning parts to support the substrates. SOLUTION: The substrate carriage 31 is formed approximately rectangular on the whole and has a central protrudent part 31a which is flat at the top and side protrudent parts 31b which are disposed at both sides of the part 31a and have inside downwards inclined slops at the top ends with 26 parallel rows of reception grooves 31d, 31e cut into the top ends of each of the protrusions 31a, 31b along the entire length, allowing the lower peripheries of Si wafers to be fitted into the reception grooves 31d, 31e, thus arranging and supporting the wafers 10 with their principal faces oriented mutually parallel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate transfer operation in which a substrate such as a silicon wafer or a glass substrate for a liquid crystal which is aligned and accommodated in a cassette is taken out from the cassette and transferred to another cassette. And a substrate extraction / accommodation device that is installed in the substrate transfer device or the like and that performs a work of extracting and accommodating a substrate from a cassette,
The present invention relates to a substrate transfer device and a substrate pedestal to be provided in the substrate extraction / accommodation device for extracting and accommodating a substrate from a cassette.

[0002]

2. Description of the Related Art Conventionally, a substrate transfer device of this type is shown in FIG.

As shown in the figure, this conventional substrate transfer apparatus is provided with a pair of first traverse bases 2 of substantially the same shape which are horizontally arranged in parallel with each other, and are arranged in parallel with each traverse base 2. And a second traverse stand 3 disposed below the base. The first traverse base 2 and the second traverse base 3 are mutually connected and integrated,
This combined body is collectively referred to as the movable base 5. The movable base 5
Is driven by a base driving means (not shown) to move forward and backward (indicated by arrow F), and is appropriately positioned at a position indicated by a two-dot chain line and a solid line in the figure.

As shown in FIG. 7, each of the first traverse bases 2 is equipped with one first cassette 7 consisting of a small-sized, low-height self-standing cassette, and a second traverse base 3 is provided. Two second cassettes 8 are mounted on the top. Specifically, the first traverse table 2 is formed with an opening 2a that opens at one end side in the moving direction thereof, and the first cassette 7 is placed so that the bottom thereof corresponds to the opening 2a. To be done. And the second traverse stand 3
Has two openings 3a opened on one end side in the moving direction and another two openings 3a opened on the other end side.
b is formed, and the second cassette 8 is placed so that the bottom portion corresponds to the opening portion 3a on the one end side. The opening 3b on the other end side is formed so as to vertically coincide with the opening 2a provided on the first traverse base 2.

Reference numeral 2b in FIG. 7 is a positioning piece for engaging the lower end portion of the first cassette 7 on the first traverse table 2 and positioning the cassette 7. Although not shown, a similar positioning piece is provided on the second traverse table 3 to position the second cassette 8.

The movable base 5 and the base driving means (not shown) described above constitute a cassette positioning means for positioning the first cassette 7 and the second cassette 8 at predetermined positions.

The first cassette 7 and the second cassette 8 will be described.

In each of the first cassette 7 and the second cassette 8, a plurality of, for example, 26 silicon wafers 10, that is, substrates are arranged at equal intervals so that their main surfaces are substantially parallel to each other. Can be housed and held. The first cassette 7 is provided for cleaning the contained silicon wafers 10, and since it is immersed in various treatment liquids together with the silicon wafers 10, in order to avoid corrosion by the treatment liquids, Teflon, etc. It is molded with the required material.

On the other hand, the second cassette 8 is for transporting the silicon wafer 10 after the cleaning process to the subsequent step, and it is not necessary to consider the corrosion resistance and the like like the first cassette 7, and the comparison is made. It is made of a general material that is relatively inexpensive.

The shapes of the first cassette 7 and the second cassette 8 are as follows.

First, as shown in FIG. 7, the above-mentioned first cassettes 7 are arranged in parallel so as to correspond to two silicon wafers 10 on the left and right lower sides of the silicon wafer 10 to be held.
It is composed of a longitudinal substrate support member 7a of a book and a pair of flat side members 7b which are interposed between the end portions of the respective substrate support members 7a and interconnect the end portions.

As shown in FIG. 8, the substrate supporting member 7a.
Is made into a substantially cylindrical shape as a whole, and the silicon wafer 1
Support grooves 7d with which the outer peripheral portion of 0 is engaged are arranged in parallel in the longitudinal direction at equal pitches. As shown, the support groove 7d
Has a substantially trapezoidal cross-sectional shape, and in this embodiment, 26 threads are formed. Therefore, 26 silicon wafers 10 can be held, each silicon wafer 10
By being engaged with the support groove 7d, are aligned and held so that their main surfaces are substantially parallel to each other.

In contrast to the above, the second cassette 8 is shown in FIG.
As shown in FIG. 10 and FIG. 10, the upper part is opened for taking in and out the silicon wafers 10, and the inner wall is provided with the support grooves 8a in which the outer peripheral parts of the respective silicon wafers 10 are engaged. Each silicon wafer 10 has a support groove 8
By engaging with a, the main surfaces thereof are aligned and held so that their main surfaces are substantially parallel to each other. An overhanging portion 8b is formed on the upper end of the second cassette 8 so as to extend outward. This second cassette 8 is also a silicon wafer 1
It accommodates 26 sheets of 0.

An opening 8c is formed at the bottom of the second cassette 8. This opening 8c is for a substrate pedestal (described later) to pass through when the silicon wafer 10 is transferred from the first cassette 7 to the second cassette 8 as described later.

As shown in FIG. 7, the first cassette 7
The second cassette 8 and the second cassette 8 are mounted so that the respective bottom openings thereof correspond to the openings 2a and 3a formed in the first traverse table 2 and the second traverse table 3, respectively.

As shown in FIG. 7, the openings 2a, 3a of the first traverse base 2 and the second traverse base 3 are
A pair of substrate pedestals 15 are arranged at predetermined positions corresponding to 3b. These board pedestals 15 have the openings 2a,
The cassettes 3a, 3b and the first cassette 7 and the second cassette 8 can be inserted into the both cassettes through the bottom openings, and each of the silicon wafers 10 in each cassette can be received while being aligned. For details, refer to FIG. 7 and FIG.
As shown in FIG. 3, the substrate pedestal 15 is formed in a substantially rectangular plate shape as a whole, and the substrate pedestal 15 is formed in the center along the longitudinal direction.
The longitudinal projections 15a of the strips also have two longitudinal projections 15 on both sides.
b are formed parallel to each other. The central protrusion 15a has a flat upper end, and the upper ends of the protrusions 15b on both sides are inclined surfaces that incline downward toward the inside. The receiving grooves 15d and 15e shown in FIGS. 11 and 12 are juxtaposed along the entire length of the protrusions 15a and 15b, 26 rows each. Each receiving groove 15d, 15e
The outer peripheral portion of the silicon wafer 10 can engage with each other, whereby the respective silicon wafers 10 are aligned and supported so that their main surfaces are substantially parallel to each other.

As is apparent from FIG. 12, each of the receiving grooves 15d and 15e has a substantially Y-shaped cross section.

The substrate pedestals 15 are carried by pedestal driving means (not shown) and are driven to move up and down.
Thereby, the first cassette 7 and the second cassette 8
Is inserted into and removed from. The pedestal driving means and the substrate pedestal 15 constitute a substrate unloading / accommodating device for unloading the silicon wafer 10 from the first cassette 7 and accommodating it in the second cassette 8.

As shown in FIG. 7, above the substrate extracting / accommodating device, the silicon wafers 10 are once received from the ascending substrate receiving bases 15 and vice versa. Delivery means 18 is provided. As shown in the figure, the delivery means 18 includes two shafts 19 that are rotatably provided, and each of the shafts 19.
A drive means 20 for relatively rotating the arm and an arm member 2 attached to the tip of each shaft 19 in a suspended state.
1, a total of four support shafts 22, that is, substrate support members, which are connected to the free ends of the arm members 21, two at one end, and extend horizontally in parallel with each other; And a guide member 24 that supports the end portion and smoothly guides the end portion in the direction to be operated. FIG.
As shown in FIG. 5, each support shaft 22 has a support groove 22a with which the outer peripheral portion of the silicon wafer 10 engages, for example, 5
The two wafers are arranged side by side along the longitudinal direction, and support 52 sheets, that is, the silicon wafers 10 for two cassettes while maintaining the aligned state.

Next, the operation of the substrate transfer device having the above structure will be described. The following operations are controlled by a control unit including a microcomputer or the like included in the substrate transfer apparatus.

In FIG. 7, two first cassettes 7 containing the cleaned silicon wafers 10 are placed on the first traverse table 2, respectively. Also, two empty second cassettes 8 are placed on the second traverse table 3. Then, the movable base 5 composed of the first traverse base 2 and the second traverse base 3 is moved forward from the position indicated by the chain double-dashed line by the operation of the base driving means (not shown) to reach the position indicated by the solid line. . As a result, the two first cassettes 7 are positioned at a predetermined position, that is, immediately above each substrate pedestal 15.

In this state, the pedestal driving means (not shown) is activated to raise both substrate pedestals 15. Both board pedestal 1
5 is a second traverse stand 3 and a first traverse stand 2
The first cassette 7 is inserted through the bottom opening of the first cassette 7 through the openings 3b and 2a formed in the. Therefore, each silicon wafer 10 in the first cassette 7 is supported by the substrate pedestal 15 and extracted upward.
At this time, with respect to the delivery means 18 disposed above, both arm members 21 included in the delivery means 18 are rotated in the mutually separated directions, and two support shafts 22 each of which should support the silicon wafer 10 are provided. It is open.

The above-mentioned two substrate pedestals 15 are further raised together with the supported silicon wafers 10, reach the maximum raised position, and are stopped. In this state, the silicon wafers 10 are located between the support shafts 22. Then, the delivery means 18 is operated and the respective support shafts 22 are closed, that is, chucked. When this chucking operation is completed, both of the substrate supporters 15 are lowered. As a result, each silicon wafer 10 engages with the support groove 22a (see FIG. 13) formed in each support shaft 22, and each support shaft 2
Received by 2.

When both of the descending substrate pedestals 15 pass through the first cassette 7, the first traverse table 2 and the second traverse table 3 and reach the lowest position, the movable base 5 is moved back. It reaches the position shown by the chain double-dashed line in FIG. As a result, the first cassette 7 is detached from directly above the substrate pedestal 15, and the second cassette 8 is positioned directly above the substrate pedestal 15 instead.

After that, both of the above-mentioned board supports 15 are raised again. Therefore, the substrate pedestal 15 passes through the opening 3a of the second traverse table 3 and the second cassette 8 to reach the highest position. As a result, the silicon wafers 10 supported by the support shafts 22 of the transfer means 18 are slightly lifted by the substrate pedestals 15 and passed to the substrate pedestals 15. Then, each support shaft 22 is opened, that is, counter-chucked.

When this anti-chucking operation is completed, both substrate pedestals 15 are lowered together with each silicon wafer 10 held by them. Therefore, each of the silicon wafers 10 is stored in the second cassette 8 and only the two substrate holders 15 further descend to reach the lowest position.

[0027]

The substrate transfer device having the above-mentioned structure has the following problems.

As described above, the substrate pedestal 15 has two upper and lower portions.
Stepped receiving grooves 15d and 15e (see FIGS. 11 and 12) are formed, and the outer peripheral portions of the respective silicon wafers 10 are brought into alignment by engaging with the receiving grooves 15d and 15e. As is apparent from FIG. 12, these receiving grooves 15d and 15e are formed by connecting the taper portions 15g and 15h, which are introduction portions for aligning the silicon wafer 10, and the taper portions 15g and 15h, to the silicon wafer 10. It is composed of slit portions 15i and 15j which are positioned substantially at the center of the regular accommodation position. The center of the regular accommodation position is shown by a chain line 26.

Width w ₁ of the slit portions 15i, 15j
Is set to be slightly larger than the thickness t of the silicon wafer 10 for the purpose of facilitating the insertion / removal of the silicon wafer 10 into / from the slit portion and preventing the sliding. Therefore, as shown by the solid line in FIG.
The inner wall surfaces of i and 15j are engaged with each other at points a and b, and an inclination θ ₁ is generated. Due to this inclination, the upper end of the silicon wafer 10 is swung by s _{1 with} respect to the center 26 of the regular accommodation position.

Specifically, the silicon wafer 10 has a diameter D.
Is 8 (inch: inch) and the thickness t is 0.725 (m
m) and the width w ₁ of the slit portions 15i and 15j
Is 0.800 (mm), the deflection s ₁ is about 1.
It becomes 70 (mm). However, this numerical value changes depending on the size of the vertical distance vd ₁ between the engaging portions a and b of the silicon wafer 10 with respect to the slit portions 15i and 15j.

In addition to the fact that the value of the deflection s ₁ is marked with about, in addition to rounding off the value to the third decimal place after calculation, the outer peripheral portion of the silicon wafer 10 is tapered.
This means that it includes an error due to 0a.

As indicated by the chain double-dashed line in FIG. 12, the silicon wafer 10 has a deflection s _{1 in the} opposite direction.
The swing width 2s ₁ is about 3.40 (mm).

In the above structure, the slit portions 15i,
The difference between the width w _{1 of} 15j and the thickness t of the silicon wafer 10 (0.800 mm-0.725 mm = 0.075 mm)
Is not so large, the swing width 2s ₁ is small. Therefore, rattling in the state where the silicon wafers 10 are aligned on the substrate pedestal 15 is suppressed, and the delivery means 1
8 includes a support groove 22a of the support shaft 22 (see FIG.
Also, the swing of the silicon wafers when the respective silicon wafers 10 are engaged with each other, that is, the impact is not strong.

However, when a relatively thin silicon wafer is handled, the swing width 2s ₁ becomes considerably large, and the silicon wafer is severely rattled on the substrate pedestal 15, and the silicon wafer is passed to the support shaft 22. At times, a large impact may be applied, and particles (parti
cre) is a concern.

When the swing width 2s ₁ is large in this way, when the silicon wafers are accommodated in the second cassette 8, the supporting groove 8a formed in the cassette 8 (see FIGS. 9 and 10). The frictional force between the wall surface of the silicon wafer and the silicon wafer may increase, and particles may be generated.

The present invention has been made in view of the above points, and provides a substrate pedestal in which the swing width of a substrate to be supported is suppressed, and a substrate extraction / accommodation device and a substrate transfer device including the substrate pedestal. The purpose is to do.

The present invention also provides a substrate pedestal, a substrate extraction / accommodation device, and a substrate transfer device that can achieve other effects.

[0038]

In order to achieve the above object, the substrate pedestal according to the present invention forms an introducing portion for aligning the substrates in the first positioning portion, and the second positioning portion in the introduction portion. A means for positioning the substrate substantially at the center and for positioning the center of the substrate at the bottom of the second positioning portion is provided. In order to achieve the same object, the substrate extraction / accommodation apparatus according to the present invention can insert a substrate into a cassette that can be aligned and held so as to be substantially parallel to each other through the bottom opening of the cassette, and A substrate pedestal that receives the substrate in an aligned state, and a pedestal driving unit that carries the substrate pedestal and moves it so as to insert into and remove from the cassette, the substrate pedestal being a first positioning portion. Forming an introducing portion for aligning the substrates, and positioning the substrate substantially at the center by the second positioning portion,
Further, means for positioning the center of the substrate is provided at the bottom of the second positioning portion. Further, in order to achieve the same object, the substrate transfer apparatus according to the present invention is a cassette positioning means for positioning the first and second cassettes which can hold the substrates in parallel so that they are substantially parallel to each other at a predetermined position. A substrate pedestal that is provided at the predetermined position and can be inserted into the first and second cassettes through the bottom openings of the respective cassettes and that receives the substrates in an aligned state; And a delivery means for delivering the substrate to the substrate pedestal, and a substrate pedestal for delivering the substrate to the substrate pedestal. The positioning part forms an introducing part for aligning the substrates, the second positioning part positions the substrate substantially at the center, and the center of the substrate is positioned at the bottom of the second positioning part. It is provided with a means for. In addition, in order to obtain various other effects, the following configurations are adopted. That is, in the substrate pedestal of the present invention, the second positioning portion is a slit having a width slightly larger than the thickness of the substrate, and the means for positioning the center of the substrate is engaged with the outer peripheral edge of the substrate. It consists of a tapered portion. Further, in the substrate pedestal, the first positioning portion is a taper portion that is continuous with the opening of the slit portion. Then
In the substrate unloading / accommodating device, the cassette is provided with support grooves in parallel with which the outer peripheral portion of the substrate is engaged. Further, in the substrate transfer apparatus, the delivery means includes a substrate support member having support grooves arranged in parallel with the outer peripheral portion of the substrate for supporting the substrates in an aligned state, and the substrate support member. Support member driving means for driving the member to engage with and disengage from the substrate.
Further, in the substrate transfer apparatus, the thickness of the substrate is t, the width of the second positioning portion is w ₂ , and the vertical distance between the engaging portion of the substrate with respect to the second positioning portion and the means is vd. _2. The vertical distance from the engaging position of the substrate to the means to the approximate center of the substrate supporting member is vd.
_3, when the opening width of the support groove of the substrate support member and the _{b 3, b 3> (w} 2 -t) are made as vd ₃ / vd ₂ + t. Further, in the substrate transfer apparatus, the first and second cassettes are provided with support grooves arranged side by side so that the outer peripheral portions of the substrates are engaged with each other.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a main part of a substrate transfer apparatus as an embodiment of the present invention will be described. However, the substrate transfer apparatus according to the present invention is similar to FIG.
Since the substrate transfer device shown in FIG. 13 has the same structure as that of the device shown in FIG. 13, the description of the structure and operation of the device as a whole will not be repeated and will be omitted.

Further, in the following description and reference drawings, the same reference numerals are given to the same or corresponding components as those of the substrate transfer apparatus shown in FIGS. 7 to 13.

In the substrate transfer apparatus according to the present invention, the substrate pedestal 31 shown in FIG. 1 is used in place of the substrate pedestal 15 shown in FIGS. 7, 11, and 12.

As shown in the figure, the substrate pedestal 31 is also formed in a substantially rectangular plate shape as a whole, and has one long protrusion 31a in the center and two long protrusions 31b on both sides. It is formed in parallel. The upper end of the central protrusion 31a is flat, and the upper ends of the protrusions 31b on both sides are inclined surfaces that incline downward toward the inside. The receiving grooves 31d and 31 are provided at the upper ends of the protrusions 31a and 31b.
26 e are juxtaposed along the entire length. The lower outer peripheral portion of the silicon wafer 10 can be engaged with these receiving grooves 31d and 31e, whereby each silicon wafer 1
0s are aligned and supported so that their main surfaces are substantially parallel to each other.

As shown in FIG. 2, the receiving grooves 31d and 3 are formed.
1e has a substantially Y-shaped cross section, and is connected to tapered portions 31g and 31h serving as first positioning portions that form an introduction portion for aligning the silicon wafers 10, and the tapered portions 31g and 31h, respectively. Slits 31i and 31j as second positioning portions that are formed by positioning the silicon wafer 10 at the approximate center of the regular accommodation position.
And The center of the regular accommodation position is indicated by a dashed-dotted line 3
3 shows.

The slit portions 31i and 31j have a width w _{2 of which} is the thickness of the silicon wafer 10 for the purpose of facilitating the insertion / removal of the silicon wafer 10 into / from the slit portion and preventing sliding. t
It is set slightly larger than. Slit portion 31i,
Tapered portions 31m and 31n that engage with the outer peripheral edge of the silicon wafer 10 are provided at the bottom of 31j. The tapered portions 31m and 31n act as means for positioning the center of the silicon wafer 10 at the center 33 of the regular accommodation position.

The silicon wafer 10 is supported by the substrate pedestal 31 having the above structure as follows.

When the silicon wafer 10 enters the receiving grooves 31d and 31e as shown in FIG. 2, the outer peripheral edge of one side of the silicon wafer 10 contacts one wall surface of the taper portion 31m as shown in FIG. . Silicon wafer 10
Slides along this one wall surface, and as a result, the outer peripheral edges of both surfaces engage with both wall surfaces of the tapered portion 31m as shown in FIG. 4, and the lower portion of the silicon wafer 10 has a center 33.
Matches Immediately after or at the same time, as shown in FIG. 5, the silicon wafer 10 is tilted, and one side thereof has the slit 3
It engages with the inner wall surface of 1j at the position of h and stands still. The tilt angle at this time is indicated by θ _{2 in} FIG.

Further, in FIG. 5, the silicon wafer 1
The points of engagement of the outer peripheral edge of No. 0 with the tapered portion 31m are indicated by f and g.

Here, the dimensional relationship between the silicon wafer 10 and each part of the apparatus will be described with reference to FIGS.

As described above, the slit portions 31i, 3 of the receiving grooves 31d, 31e formed in the substrate support 31 are formed.
Since the width w _{2 of} 1j is slightly larger than the thickness t of the silicon wafer 10, the silicon wafer 10 has an inclination θ ₂ . Due to this inclination, the upper end portion of the silicon wafer 10 swings by s _{2 with} respect to the center 33 of the regular accommodation position. Specifically, the silicon wafer 10 has a diameter D of 8
(Inch: inch) and the thickness t is 0.725 (mm), and the width w ₂ of the slit portions 31i and 31j is 0.
If it is 800 (mm), this deflection s ₂ is about 1.03.
(Mm). However, this numerical value is the engagement points f and g of the silicon wafer 10 with respect to the taper portion 31m provided at the bottom of the lower slit portion 31i (see FIG. 5) and the engagement portion with respect to the inner wall surface of the upper slit portion 31j. It changes according to the set value of the vertical distance vd _{3 from} h.

The value of the above-mentioned deflection s ₂ is set to be about that the value of the third place below the decimal point is rounded off in the calculation, and the outer peripheral part of the silicon wafer 10 is tapered.
This is due to the inclusion of an error due to 0a.

As shown by the two-dot chain line in FIGS. 5 and 6,
Since the silicon wafer 10 may also have a shake s ₂ on the opposite side, the shake width 2s ₂ is about 2.06 (mm).

As described above, in the substrate transfer apparatus, the lower ends of the silicon wafer 10 are positioned by the tapered portions 31m and 31n without being offset from the center 33 of the regular accommodation position, and the upper end of the silicon wafer 10 is deflected. The width can be kept small.

Therefore, the backlash of the silicon wafer 10 on the substrate pedestal 31 is suppressed, and the delivery means 18 is provided.
(See FIG. 7) The support wafer 22 has a support groove 22a (see FIG. 13) provided with a support groove 22a. Kept in.

Since the swing width 2s ₂ of the silicon wafer 10 is small as described above, when the silicon wafer 10 is housed in the second cassette 8 shown in FIGS. 7, 9 and 10, it is formed in the cassette 8. The frictional force between the wall surface of the supported groove 8a and the silicon wafer 10 is also small, and this also prevents the generation of particles.

By the way, the dimension shown by symbol b ₃ in FIG. 6, that is, the opening width of the support groove 22a formed in the support shaft 22 of the delivery means 18 (see FIG. 7) satisfies the following equation. Is set to.

B ₃ > (w ₂ −t) vd ₃ / vd ₂ + t, where t: thickness of the silicon wafer 10 w ₂ : receiving grooves 31 d, 31 e formed in the substrate pedestal 31
Widths vd ₂ of the slit portions (second positioning portions) 31i, 31j of: the engaging portions h of the silicon wafer 10 with respect to the slit portions 31j (see FIG. 5) and the engaging portions f, g with respect to the tapered portion 31m (see FIG. 5). vertical distance between the reference) vd _3: the slit portion engaging portion f of the silicon wafer 10 with respect to 31m (the from see FIG. 5) support shaft 2
Vertical distance to center 22b of 2 (upper support shaft)

That is, in view of suppressing the swing width of the silicon wafer 10 to be small, the opening width b ₃ of the support groove 22a of the support shaft 22 is set to a necessary minimum value. As a result, even if the opening width b ₃ is small, the silicon wafer 10 can surely enter the support groove 22a.

The support groove 22a has a trapezoidal cross section, and the bottom width b ₂ thereof is smaller than the opening width b ₃ , but the bottom width b ₂ is set so as to satisfy the following equation. You may.

B ₂ > (w ₂ −t) vd ₃ / vd ₂ + t ...

That is, a slight inclination θ ₂ on the substrate pedestal 31.
When the support shaft 22 holds each of the silicon wafers 10 aligned with each other, the peripheral edge of the silicon wafer 10 is always within the width b ₂ . By doing so, it is also possible to prevent the outer periphery of the silicon wafer 10 from sliding on the sloped portion of the support groove 22a having a trapezoidal cross section, and to prevent generation of particles.

A method of deriving the above equation will be briefly described.

First, in FIG. 5, the deviation amount of the center of the silicon wafer 10 (deviation amount from the center 33) at the value of e, that is, at the level of the engaging portion h of the silicon wafer 10 with respect to the inner wall surface of the slit portion 31j. Think The engagement point h is located at a vertical distance vd ₂ from the engagement points f and g of the silicon wafer 10 with respect to the tapered portion 31m. Therefore, the engagement position h is located at a vertical distance vd ₃ from the engagement points f and g. The deviation amount e ₂ (not shown) at the center 22b of the shaft 22 is proportional to

E ₂ = e · vd ₃ / vd ₂ .

In the above-mentioned e, since the silicon wafer 10 is shifted from the center to one side within the width of the slit portion 31j,

[0065] Thus _{e = (w 2 -t) /} 2, is _{e 2 = (w 2 -t)} vd 3 / 2vd 2.

Since the silicon wafer 10 can be tilted to the opposite side with the center 33 as a boundary, and the above e ₂ is the amount of deviation of the center of the silicon wafer 10, the thickness t is 1 or less.
/ Add 2 one by on both sides (i.e. adding t) and that to give the _{(w 2 -t) vd 3 /} vd 2 + t. This value is the center 22b of the support shaft and 22.
Since it is the swing width of the silicon wafer 10 at the level, it is necessary to set as in the above formula in order to fit the silicon wafer 10 having this swing width into the opening width b ₃ of the support groove 22a of the support shaft 22.

In the present embodiment, the substrate pedestal 31
A first positioning part and a second positioning part provided in
Further, the means for providing the bottom of the second positioning portion for positioning the center of the silicon wafer 10 are respectively tapered portions 31g, 31h and slit portions 31i, 31.
Although the j and the tapered portions 31m and 31n are used, the form of each of these positioning portions and means is not limited to that of the present embodiment, but can be variously changed.

However, the taper portion and the slit portion are easy to form, and if these are combined to form the receiving grooves 31d and 31e having a Y-shaped cross section as in the present embodiment, the silicon wafer 10 is held and held. It is useful because it can be released smoothly.

[0069]

As described above, according to the present invention, in the substrate pedestal, the introduction portion for aligning the substrates is formed at the first positioning portion, and the second positioning portion substantially centers the substrate. And a means for positioning the center of the substrate on the bottom of the second positioning portion. With this configuration, the lower end of the substrate is positioned without being offset from the center of the regular accommodation position, and the swing width on the upper end side of the substrate can be suppressed to be small. Therefore, the rattling of the substrate on the substrate pedestal is suppressed, and when the substrate is engaged with the supporting groove of the substrate supporting member included in the transferring means, the swaying of the substrate, that is, the impact is small, and the generation of particles is generated. Is prevented,
The environment is kept clean. Further, since the swing width of the substrate is small, when the substrate is accommodated in the cassette, the frictional force between the wall surface of the support groove formed in the cassette and the substrate is small,
From this point as well, the generation of particles is prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state where a substrate pedestal according to the present invention supports a silicon wafer.

FIG. 2 is a vertical cross-sectional view of a part of the substrate pedestal, taken along the line BB in FIG.

FIG. 3 is a diagram for explaining the operation when the silicon wafer is engaged with the receiving groove of the substrate pedestal shown in FIGS. 1 and 2.

FIG. 4 is a diagram for explaining the operation when the silicon wafer is engaged with the receiving groove of the substrate pedestal shown in FIGS. 1 and 2.

5 is a diagram for explaining the operation when the silicon wafer is engaged with the receiving groove of the substrate pedestal shown in FIGS. 1 and 2. FIG.

FIG. 6 is a partial view showing a state in which a silicon wafer is engaged with the substrate pedestal shown in FIGS. 1 and 2 and a support shaft provided on the delivery means located above the substrate pedestal. It is a side view containing a cross section.

FIG. 7 is a perspective view of a conventional substrate transfer device.

8 is a plan view showing a longitudinal support member included in a (first) cassette handled by the substrate transfer apparatus shown in FIG. 7 and a part of a silicon wafer engaged with the longitudinal support member.

9 is a longitudinal sectional view of a (second) cassette handled by the substrate transfer apparatus shown in FIG.

FIG. 10 is a view taken along the line AA in FIG.

11 is a front view showing a substrate pedestal included in the substrate transfer device shown in FIG. 7 and a silicon wafer.

12 is a vertical cross-sectional view showing a state where a silicon wafer is engaged with a part of the receiving groove of the substrate pedestal shown in FIG.

13 is a side view showing a state in which a silicon wafer is engaged with a support shaft which is a part of the delivery means included in the substrate transfer device shown in FIG. 7.

[Explanation of symbols]

2 1st traverse stand 3 2nd traverse stand 5 Movable base 7 1st cassette 7a (It comprises in the 1st cassette 7)
Longitudinal support member 7d Support groove 8 (formed on the support member 7a) Second cassette 8a (Support groove formed on the second cassette 8) 10 Silicon wafer (substrate) 18 Delivery means 20 (The delivery means 18 has ) Driving means 22 Support shaft (included in the delivery means 18) (Substrate support member) 22a Support groove formed on the support shaft 31 Substrate pedestals 31d and 31e (Reception groove formed on the substrate pedestal 31) 31g, 31h (forms part of the receiving grooves 31d and 31e) Tapered part (first positioning part) 31i, 31j (forms part of receiving grooves 31d and 31e) Slit part (second positioning part) 31m (slit part) Tapered portion (provided at the bottom of 31i, 31j) (means for positioning the center of the silicon wafer 10 at the center 33 of the regular accommodation position) 33 ( Center of the regular accommodation position where the silicon wafer 10 should be positioned

Claims (9)

[Claims] 1. In a substrate pedestal to be arranged and supported so that the substrates are arranged substantially parallel to each other, a first positioning portion forms an introducing portion for aligning the substrates, and a second positioning portion forms the introduction portion. A substrate pedestal, characterized in that means is provided for positioning the substrate substantially at the center and for positioning the center of the substrate at the bottom of the second positioning portion. 2. The second positioning portion comprises a slit portion having a width slightly larger than the thickness of the substrate, and the means for positioning the center of the substrate comprises a taper portion which engages with an outer peripheral edge of the substrate. 1. The method according to claim 1, wherein
The board pedestal described. 3. The substrate pedestal according to claim 2, wherein the first positioning portion comprises a taper portion which is continuous with the opening portion of the slit portion. 4. A substrate pedestal that can be inserted through a bottom opening of the cassette into a cassette that can hold the substrates in a substantially parallel alignment, and that receives the substrates in an aligned state. In a substrate unloading / accommodating device having a pedestal driving means for carrying a pedestal and moving it to insert into and remove from the cassette, the substrate pedestal is for aligning the substrates at a first positioning portion. Substrate characterized by forming a lead-in portion, positioning the substrate at a substantially central portion by the second positioning portion, and providing a means for positioning the center of the substrate at the bottom portion of the second positioning portion. Withdrawal storage device. 5. The substrate extraction / accommodation device according to claim 4, wherein the cassette has a support groove provided in parallel with which an outer peripheral portion of the substrate is engaged. 6. A cassette positioning means for positioning first and second cassettes at predetermined positions, each of which is capable of holding the substrates in alignment so as to be substantially parallel to each other, and the first and second cassettes provided at the predetermined positions. A substrate pedestal that can be inserted into the second cassette through the bottom opening of each cassette and receives the substrates in an aligned state; and a substrate pedestal that carries the substrate pedestal and is inserted into each of the cassettes,
A substrate transfer apparatus comprising: a pedestal driving means for moving the substrate so that it can be pulled out; and a delivery means for delivering the substrate to the substrate pedestal, wherein the substrate pedestal has a first positioning portion for the substrate. Means for aligning the substrate at a substantially central portion by the second positioning portion, and for positioning the center of the substrate at the bottom portion of the second positioning portion. Substrate transfer device characterized by. 7. The delivery means includes a substrate support member having support grooves arranged in parallel with each other to engage an outer peripheral portion of the substrate to support each of the substrates in an aligned state, and the substrate support member. 7. The substrate transfer apparatus according to claim 6, further comprising: a supporting member driving unit that is driven to engage with and disengage from. 8. The thickness of the substrate is t, the width of the second positioning portion is w ₂ , the vertical distance between the engaging portion of the substrate with respect to the second positioning portion and the means is vd ₂ , and the means. When the vertical distance from the engagement position of the substrate to the substantial center of the substrate support member with respect to is vd ₃ and the opening width of the support groove of the substrate support member is b ₃ , b ₃ > (w ₂ −t) vd The substrate transfer device according to claim 7, wherein the substrate transfer device has a ratio of ₃ / vd ₂ + t. 9. The first and second cassettes are provided with supporting grooves arranged in parallel with each other to engage with the outer peripheral portion of the substrate, according to any one of claims 6 to 8. The substrate transfer apparatus described.