JP2002130942A - Drying method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device of completely drying an object to be dried such as a shipping box and the like used for storing a semiconductor wafer having a complicated structure and transporting it for a short time. SOLUTION: An object to be dried is allowed to rotate during revolution in a method of allowing the object to be dried to revolve and drying it by a centrifugal force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for drying an object, and more particularly, to a method for storing and transporting an object having a complicated structure, in particular, a semiconductor wafer such as a silicon wafer, a photomask, and the like. The present invention relates to a drying method and apparatus suitable for washing and drying a plastic case in an industry requiring cleanliness.

[0002]

[Related Art] Semiconductor wafers such as silicon are generally
A slicing step of slicing the single crystal ingot to obtain a thin disk-shaped wafer, a chamfering step of chamfering the outer periphery of the wafer obtained in the slicing step to prevent cracking and chipping, and flatten the wafer. A lapping process for forming a wafer, an etching process for removing processing distortion remaining on the chamfered and wrapped wafer, a polishing (polishing) process for mirror-polishing the wafer, and a cleaning process for cleaning the polished wafer. The dried semiconductor wafer is stored in a shipping box made of plastic or the like and transported from a wafer maker to a device maker.

[0003] Usually, the shipping box is cleaned by a wet method in order to prevent particles from adhering to the semiconductor wafer during transportation. At the end of wet cleaning, water droplets adhere to the plastic surface.To dry it, a method of drying and dehydrating by placing the shipping box in a clean oven and spending time at a certain temperature or higher is generally used. ing.

[0004]

However, the above method is inefficient because the time required for drying is long. Further, if the drying temperature is increased to shorten the time, problems such as deformation of the shipping box may occur. Other methods of drying the shipping box include air drying,
There are methods such as microwave drying, air blow, air knife, vacuum drying, vacuum drying, infrared drying, and organic solvent drying, but all of these methods require a long time for drying.

[0005] Also, by rotating the shipping box,
After removing water droplets by centrifugal force, a method of removing remaining water droplets by air blow is also considered, but since the shipping box itself is a combination of parts consisting of several points with complex shapes, it can be rotated or blown with an air knife. At present, the dropped water drops remain on some parts and cannot be completely removed.

The present invention has been made in view of the above points, and provides a method and an apparatus for completely drying a material to be dried such as a shipping box used for transporting and transporting a semiconductor wafer having a complicated structure in a short time. The purpose is to:

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, a drying method of the present invention is a method of revolving an object to be dried and drying by centrifugal force, wherein the object to be dried is rotated during revolution. Features. According to this drying method,
Water droplets can be reliably removed even from a dried object having a complicated shape such that water subjected to centrifugal force does not escape due to its structure. Also, by drying at room temperature, a cooling time after drying is not required as compared with a method of drying in an oven, so that when drying in an oven, the drying time which took about one hour is only several minutes, The drying efficiency is significantly improved.

In the drying method of the present invention, it is preferable that the material to be dried is rotated continuously or intermittently, that is, continuously or intermittently during the revolution, and in particular, it is inverted at least once (180).
(Rotation). This makes it possible to reliably remove water droplets by a simpler operation.

In the drying method of the present invention, when rotating a plurality of objects to be dried, it is preferable that each of the objects is rotated in synchronization. By doing so, it is possible to avoid breaking the balance of revolution during centrifugal dehydration.

[0010] In the drying method of the present invention, the revolution speed is 3
It is preferably set to 00 to 800 rpm. Revolution speed is 3
If the rotation speed is less than 00 rpm, the time required for drying becomes long, and the efficiency becomes extremely poor. Also,
If the revolving speed is higher than 800 rpm, it may cause a failure of the apparatus, which is not preferable.

[0011] In the drying method of the present invention, a shipping box for accommodating a semiconductor wafer can be given as an object to be dried suitably. The present invention is particularly suitable for drying a shipping box having a complicated structure.

A drying apparatus according to the present invention is characterized in that a spin drying apparatus for revolving an object to be dried and drying it by centrifugal force is provided with a rotation holding member for rotating the object to be dried. According to this apparatus, the drying method of the present invention can be easily realized.

In the drying apparatus according to the present invention, if a plurality of the above-mentioned rotation holding members are provided, and each rotation holding member is configured to rotate in synchronization with each other, it is possible to perform a revolution without breaking the balance.

In the drying apparatus according to the present invention, if the rotation axes of the plurality of rotation holding members are arranged axially symmetrically with respect to the rotation axis of the spin drying apparatus, the rotation can be performed without breaking the balance.

The revolving speed of the spin dryer is 300 to
It is preferable to control in the range of 800 rpm.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings, but modifications other than those shown in the drawings may be adopted without departing from the technical idea of the present invention.

FIG. 1 is a perspective explanatory view showing one embodiment of a drying apparatus according to the present invention, in which a main dewatering tank is shown in a transparent state. FIG. 2 is a partially transparent side view of FIG. 1 showing the rotation drive mechanism in a transparent state.

1 and 2, reference numeral 10 denotes a drying apparatus according to the present invention. The drying device 10 has a base 12 and a main dewatering tank 14 which is attached to the base 12 and has a hollow interior, similarly to a conventionally known spin drying device. 1
Reference numeral 6 denotes a main shaft provided at the center of the lower surface of the base 12.
By rotating the main shaft 16 by a motor or the like (not shown), the base 12 and the main dewatering tub 14 can be rotated.

On the upper surface of the base 12, a rotation holding member for holding and rotating the object to be dried, for example, the shipping box B, for example, a plurality of (four in the illustrated example) sub-dehydration tanks 18 are rotatably mounted. I have. The auxiliary dewatering tub 18 is formed in a cylindrical shape which is opened up and down, and a large number of small dewatering holes 20 are formed in a side wall thereof. The material of the sub-dehydration tub 18 is not particularly limited, but vinyl chloride resin, stainless steel, or the like is preferably used. When the base 12 is rotated by the rotation of the main shaft 16, these sub-dehydration tubs 18 rotate the rotation axis of the main shaft 16 to the revolving shaft 17 of the sub-dehydration tub 18.
Revolves as

As shown in FIG. 2, a stepping motor or a similar rotation driving mechanism 2 is provided inside the base 12.
2 are installed. The drive shaft 24 of the rotation drive mechanism 22
a is connected to one of the auxiliary dewatering tanks 18 and has a drive pulley P1 attached thereto.

Reference numerals 24b and 24b denote driven shafts provided inside the base portion 12 in correspondence with the drive shafts 24a. The driven shafts 24b and 24b are connected to the remaining auxiliary dewatering tanks 18 and have driven pulleys P2 and P2 attached thereto. The driven pulley P2 is connected to the drive pulley P1 by a pulley belt V. When the rotation drive mechanism 22 is driven to rotate the drive shaft 24a and the drive pulley P1, the driven pulley P2 and the driven shaft 24b rotate via the pulley belt V. The driven shaft 24b and the driven pulley P2 are provided three each in the examples of FIGS. 1 and 2, but FIG. 2 shows only two of them.

When the drive shaft 24a and the driven shaft 24b rotate, the plurality of sub-dehydration tanks 18 connected to the drive shaft 24a and the driven shaft 24b also rotate (rotate) at the same time. That is, all of the plurality of sub-dehydration tanks 18 are simultaneously rotated in synchronization. In this case, each sub-dehydration tub 18 rotates on its own rotation axis of the drive shaft 24 a and the driven shaft 24 b as the rotation axis 25 of the sub-dehydration tub 18. In FIG. 2, reference numeral 26 denotes a balancer for balancing the weight with the rotation drive mechanism 22.
The base 12 is provided at a position opposite to the position where the rotation drive mechanism 22 is installed. Further, it is preferable that two to four sub-dewatering tubs 18 are arranged symmetrically with respect to the revolving shaft 17 from the viewpoint of rotational balance.

As shown in FIG. 3, a guide rail 28 is provided on the inner peripheral wall surface of the sub-dehydration tub 18 in a vertical direction. A parts holding cartridge 30 is detachably inserted into the sub-dehydration tub 18 via the guide rail 28.

The part holding cartridge 30 holds the object to be dried, for example, the parts of the shipping box B, that is, the lid B1, the inner cassette B2, the outer box B3, and the like, and can be inserted and stored in the auxiliary dewatering tank 18. Any shape may be used. For example, as shown in FIG. 3, each of the parts B1 to B3 may be held in a plurality of holding holes 32 in the longitudinal direction of the long plate-shaped main body.

Since the drying apparatus 10 of the present invention has the above-described configuration, when drying the material to be dried, for example, the shipping box B, the centrifugal force generated by the rotation of the main dewatering tank 14 acts on the dried material. The object B to be dried revolved by rotating the auxiliary dewatering tank 18 containing the dried material B
Can be changed to remove all the water droplets present on all surfaces of the object B to be dried.

Hereinafter, the case where the shipping box B is further dried will be described. First, as shown in FIG. 3, each part of the shipping box B, for example, the lid B1, the inner cassette B2, and the outer box B3 is held and fixed to the holding hole 32 of the part holding cartridge 30 by, for example, a belt or the like. The parts holding cartridge 30 is inserted through the guide rail 28 into the sub-dehydration tub 18 and the parts B1 to B3 are stored.

Next, by rotating the main shaft 16, the base 12, the main dewatering tub 14, and the sub dewatering tub 18 are rotated, and at the same time, each of the parts B1 to B3 is also rotated. The rotation accompanying the rotation of the base 12 revolves around the auxiliary dewatering tub 18 and each part, B1 to B3, and centrifugal force acts on each part, B1 to B3 due to this revolution.
Due to this centrifugal force, water droplets attached to the parts B1 to B3 are removed, and are discharged to the outside as a drain D as shown in FIG. Here, the rotation speed of the base 12 and the main dewatering tub 14 is set to about 300 rpm to 800 rpm.

When the rotation speed of the base 12 and the main dewatering tub 14 has sufficiently reached this range, each sub dewatering tub 18 starts to rotate while keeping the revolution speed approximately as shown in FIG. The operation of this rotation is as follows.

Each part B1 to B of the shipping box B
The water droplets adhering to the surface of No. 3 are centrifugally applied to each part B1
In order to separate from water droplets B3, if there is a shipping box B itself in the direction in which the centrifugal force acts, it will hinder the separation of water droplets. In such a case, since water droplets are trapped in a so-called bag structure, dehydration by centrifugal force alone is no longer possible.

In order to avoid this situation, a state in which the shipping box B itself does not exist in the direction in which the centrifugal force acts by rotating each of the parts B1 to B3 of the shipping box B, that is, the direction in which the water drops separate, is realized. By doing so, water droplets adhering to all surfaces of the parts B1 to B3 are separated from the object to be dried. Here, various methods of rotation are conceivable, and inverting only once during revolving,
This is the simplest method. In addition, the secondary dewatering tank may be rotated continuously or intermittently (continuously or intermittently) while the main dewatering tank is revolving or during a certain period of time. Such a method is particularly effective when the structure is complicated like the shipping box B.

Each part B1 to B
3 with respect to the rotation shaft 25, so that the left and right balance can be maintained even during rotation, and the parts B1 to B3 during centrifugal dehydration.
In order to avoid breaking the rotation balance due to the rotation of
It is preferable that parts having the same shape and weight are provided in the same direction in the sub-dehydration tank 18 symmetrical to the revolving shaft 17.

[0032]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which, of course, should not be construed as limiting.

(Example 1) As shown in FIG.
The shipping box B containing a silicon wafer having a diameter of 300 mm was dried using a drying apparatus having four 8s arranged. The lid B1, upper part of the inner cassette B2, and parts of the outer box B3 are placed in the upper part, the middle part, and the lower part of the parts holding cartridge 30 inserted into each sub-dehydration tank 18. Each sub-dehydration tank 18 has a total of four sets of shipping box B parts B
1 to B3 are similarly stored. The revolving speed of the main dewatering tub 14 is set to 600 rpm and rotated for 2 minutes, and then the sub-dewatering tub 18 is inverted (180 ° rotation) to continue the rotation for another 2 minutes. After the rotation for a total of 4 minutes, the rotation of the main dewatering tub 14 is stopped, and the shipping box B placed in the sub dewatering tub 18
Of all the parts B1 to B3 were visually inspected. As a result, water drops on the surface of the shipping box could not be confirmed.

(Comparative Example 1) A 300 mm shipping box B was dried under the same conditions as in the example except that the spin-drying tub was rotated for 4 minutes without inverting the sub spin-drying tub 18. As a result, water droplets adhered to the inside of the lid B1, the groove of the inner cassette B2, and the inside of the outer box B3, and drying was incomplete.

Although the embodiment of the present invention has been described above, the present invention is not limited to the embodiment, and it goes without saying that various modifications can be made without departing from the scope of the invention. Absent. For example, in the above embodiment,
The sub-dehydration tub 18 was used as an example of the rotation holding member. However, if the object to be dried can be held and rotated, it is not particularly necessary to store the material in the sub-dehydration tub, and the part holding cartridge is held by the holding frame. Alternatively, a structure in which the rotation holding members are separated from each other by partition walls may be employed to prevent mutual interference. In addition, if the whole balance is maintained, it is not necessary to rotate each of them in synchronization.

[0036]

According to the present invention, in a method of revolving an object to be dried and drying by centrifugal force, the object to be dried is rotated during the revolution so that water subjected to the centrifugal force does not escape from the structure. Water droplets can be reliably removed even from an object to be dried having such a complicated shape. Further, by drying at room temperature, a cooling time after drying is not required as compared with a method of drying in an oven, so that drying efficiency is significantly improved.

[Brief description of the drawings]

FIG. 1 is a perspective explanatory view showing one embodiment of a drying apparatus of the present invention in a state where a main dewatering tank is seen through;

FIG. 2 is a partially transparent side view of FIG. 1 showing a rotation driving mechanism in a transparent state;

FIG. 3 is a perspective explanatory view showing a case where each part of a shipping box is held and fixed to a sub-dewatering tank of the drying apparatus of the present invention using a part holding cartridge, with a main dewatering tank part shown in a transparent state.

FIG. 4 shows shipping in the sub-dehydration tub when the sub-dehydration tub is inverted (180 ° rotation) during the rotation drying process of the drying apparatus of the present invention, that is, during the revolution of the sub-dehydration tub during the revolution of the sub-dehydration tub. It is a top view explanatory view showing the direction of each part of the box,
(A) shows before inversion, (b) shows during inversion, and (c) shows after inversion.

[Description of Signs] 10: Drying device, 12: Base, 14: Main dewatering tank, 16:
Main shaft, 17: revolving shaft, 18: auxiliary dewatering tank, 20: small hole for dewatering, 22: rotation drive mechanism, 24a: drive shaft, 24b: driven shaft, 25: rotation shaft, 28: guide rail, 30: parts holding Cartridge, 32: holding hole, B: shipping box, B1: lid, B2: inner cassette, B3:
Outer box, D: drain, P1: drive pulley, P2: driven pulley, V: pulley belt.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3L113 AA04 AB08 AC63 AC68 BA34 CB34 DA10 DA24

Claims (10)

[Claims] 1. A method of revolving an object to be dried and drying it by centrifugal force, wherein the object to be dried is rotated during its revolution. 2. The drying method according to claim 1, wherein the object to be dried is inverted at least once during revolution. 3. The drying method according to claim 1, wherein the object to be dried is rotated continuously or intermittently during revolution. 4. When rotating a plurality of objects to be dried,
4. The method according to claim 1, wherein each of them is rotated in synchronization.
4. The drying method according to any one of 3. 5. The revolving speed of the object to be dried is 300 to 80.
The drying method according to any one of claims 1 to 4, wherein the drying method is set to 0 rpm. 6. The shipping object according to claim 1, wherein the object to be dried is a shipping box for storing a semiconductor wafer.
The drying method according to any one of the above. 7. A spin dryer for revolving an object to be dried and drying it by centrifugal force, comprising a rotation holding member for holding and rotating the object to be dried. 8. The drying apparatus according to claim 7, wherein a plurality of the rotation holding members are provided, and each rotation holding member rotates in synchronization. 9. The drying apparatus according to claim 8, wherein the rotation axes of the plurality of rotation holding members are arranged axially symmetrically with respect to the revolution axis of the spin dryer. 10. The revolving speed of the spin dryer is 30.
The drying device according to any one of claims 7 to 9, wherein the drying device is controlled in a range of 0 to 800 rpm.