JP2561015Y2 - Polycrystalline silicon storage container - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container for accommodating polycrystalline silicon to be shipped as a product. The present invention relates to a storage container that is free from problems such as breakage of bags, is convenient to handle, and has high transport and storage reliability.

[0002]

2. Description of the Related Art In the production of polycrystalline silicon, usually, polycrystalline silicon grown in a rod shape of about 1 to 2 m is cut into chunks called chunks having a length of about 200 mm.
The chunk is further crushed into a small mass called a lamp, and is subjected to etching cleaning to remove an oxide film on the surface, and then shipped as a product. In this case, polycrystalline silicon used as a semiconductor material needs to have extremely high purity. Therefore, the polycrystalline silicon shipped as a product is not contaminated from the outside,
Shipped in bags of high polymer material such as polyethylene.

Conventionally, washed lamp-shaped polycrystalline silicon is directly packed in a bag and shipped. In many cases, a sharp crushed end protrudes from the outer surface of the polycrystalline silicon. There is a problem in that the bag is broken by directly touching the storage bag, contaminants enter from the outside, and fine breakage of the bag adheres to contaminate the product. Further, in the conventional manufacturing process, since the lamp-shaped polycrystalline silicon is manually bagged after being cleaned, it is recontaminated, requires a lot of manpower, and the work efficiency is low.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the conventional bagging operation, and is hardly damaged even when polycrystalline silicon having a sharp crushed end is accommodated. It is an object of the present invention to provide a storage container that prevents re-contamination in a series of operation steps leading to and improves the operation efficiency.

[0005]

According to the present invention, there is provided a polycrystalline silicon container having the following structure. (1) An inner basket for accommodating massive polycrystalline silicon, and an outer bag for accommodating the inner cage, wherein the inner cage has a hole diameter smaller than the average outer diameter of the projection of the crushed end of the polycrystalline silicon. A washing basket having a large number of liquid passage holes is also used, while the outer bag is sealed in a state in which a lump of polycrystalline silicon that has undergone a washing step is housed in an inner basket. container. The container of the present invention includes the following aspects. (2) The container according to (1), wherein the inner cage is formed by a mesh member having a hole diameter smaller than the average outer diameter of the projection at the crushed end of the polycrystalline silicon. (3) The container according to (1) or (2), wherein a rib forming a space between the inner basket and the outer bag is formed on an outer surface of the inner basket. (4) The inner cage is formed so as to be able to be hung with the opening part upward so as to wash the polycrystalline silicon while being housed in the inner cage, and the inner cage is housed with the washed polycrystalline silicon. The storage container according to the above (1), (2) or (3), which is housed in an outer bag, the upper end of the outer bag is heat-sealed, or the opening of the outer bag is closed by a lid material.

[0006] Generally, a shipping container is used to shield and protect the contents from the outside. On the other hand, the cleaning basket used in the cleaning step is such that the polycrystalline silicon inside can easily come into contact with the cleaning liquid. , Which are used for different purposes. In addition, the former is of a closed type with respect to the outside, but the latter is of an open type and has no commonality. Therefore, conventionally, a container for shipping and a washing basket are not used at all. In the present invention, the shipping container is formed by the outer bag and the inner basket, so that the inner basket can be used also as the washing basket.

The shape of the inner basket may be a box shape with an open top, or a cylindrical shape. In addition, from the viewpoint of ease of handling, a shape that can be stood still with the opening facing upward is preferable. The external dimensions are appropriately determined according to the amount and size of the polycrystalline silicon lump to be accommodated. Further, a material having sufficient strength according to the shape and size of the inner cage and having corrosion resistance to the cleaning liquid is selected. Note that a metal material is not preferable because it becomes a contamination source of polycrystalline silicon.

[0008] As an example of the inner basket, a polypropylene inner size of 170 mm accommodating a silicon lamp of 5 kg.
A square-shaped basket of × 170 mm × 200 mm is presented. Polypropylene is a material that has corrosion resistance to a cleaning liquid (mixed acid of hydrofluoric acid and nitric acid), withstands high temperatures in a drying step after cleaning, and that is less contaminated with silicon. In general, a rectangular package is used from the viewpoint of volumetric efficiency, and a suitable storage capacity of about 5 kg is appropriate from the viewpoint of workability.

Since the above-mentioned inner basket is also used as a washing basket, it is required that the washing liquid enter and exit well when immersed in the washing liquid, and that the liquid drains well. For this purpose, a large number of liquid passage holes having a large hole diameter may be provided on the side wall and the bottom surface. However, as described above, a sharp crushed end is often projected on the surface of the contained polycrystalline silicon. If the liquid passage hole is large, there is a concern that the crushed end protrudes to the outside and damages the outer bag.Therefore, the diameter of the crushed end protrudes to the outside and does not damage the outer bag. A liquid passage hole having a smaller hole diameter than the outer diameter is provided. Normally, the end face angle of the crushed end is 45 ° to 60 °, so in the case of an inner basket having a capacity of 3 kg, a round hole having a diameter of 3 mm to 4 mm or a short side 3
Any rectangular or square liquid passage hole having a size of 4 mm to 4 mm may be used. When the liquid passage hole is enlarged, a rib or the like may be protruded from the outer surface of the inner cage to form a space between the inner cage and the outer bag. Depending mesh member with a pore size suitable for vent inlet hole may be formed inner basket and appropriate number bored the liquid passing hole well or plate member be formed above the cage. In order to improve the flow of the cleaning liquid, the area of the liquid passage hole provided in the bottom surface of the inner cage should be 15% in terms of the area ratio of the entire bottom surface.
It should be about. If the area of the liquid passage hole is too large, small pieces of polycrystalline silicon flow out in the washing step, and the strength of the bottom surface is insufficient, which is not preferable.

[0010] As a preferred embodiment, the inner basket is formed so that it can be hung with its opening upward. For example, hooks are provided on both sides of the inner cage, or projections for engaging the hooks are provided. In addition, the inner basket is put into the outer basket that can be freely suspended, and after being subjected to the cleaning process in this state, the inner basket is taken out of the outer basket, and the silicon lamp is housed in the outer bag as the inner basket. May be.
By performing a series of operations from the washing step to the loading into the outer bag after washing in a state where the inner basket is suspended, continuous and efficient operations can be performed. Also suitable for automation.

The outer bag is sealed with an inner basket containing polycrystalline silicon inserted therein. The sealing method is not limited. For example, the upper end of the outer bag may be hermetically sealed by heat welding, or the opening may be covered with a lid member, and the entire periphery thereof may be heat-sealed or hermetically sealed with an adhesive.
As the material of the outer bag, polyethylene which is less likely to be contaminated by silicon and which is easily heat-welded is generally used.

[0012]

1 to 3 show a specific example of a container according to the present invention.
Shown in In FIG. 1, an inner basket 10 made of polypropylene is used.
It has a rectangular shape with a slightly rectangular base. On both sides of the inner basket 10, eight rows of liquid passage holes 11 each having a diameter of 3 mm to 4 mm are provided vertically and horizontally, and 36 liquid passage holes each having a diameter of 3 to 4 mm are provided on the bottom surface. The inner basket 10 is placed in an outer bag 12 made of polyethylene, and the upper opening 13 of the outer bag 12 is closed with its center aligned.

The container shown in FIG. 2 has an inner basket 1 similar to that shown in FIG.
0 is placed in an outer bag 12 made of polyethylene, and its upper end opening is covered with a lid 14 made of polyethylene.
Is thermally sealed to the opening edge of the outer bag 12 and sealed. The inner basket 10 is provided with a liquid passage hole 11 as in the case of FIG.

The container shown in FIG. 3 is formed by an outer bag 17 having the same shape as a cylindrical polypropylene inner cage 16, and a peripheral surface of the inner cage 16 is similar to that of the inner cage 10 shown in FIG. Are formed in six rows and 21 rows. The bottom surface is provided with 25 round holes having a diameter of 4 mm. The upper end opening of the outer bag 17 is covered with a circular lid 18, and the periphery of the lid 18 is adhered to the outer bag 17.

[0015]

[Effect of the Invention] The storage container of the present invention is formed of an outer bag and an inner basket, and since the inner basket also serves as a cleaning basket, the crushed polycrystalline silicon is housed in the inner basket for cleaning. Since it can be dried and packed in an outer bag as it is, there is no problem of recontamination after washing, and a series of operations from washing to packing for shipping can be performed continuously, so work efficiency is improved. Is greatly improved. Also,
Since the crushed polycrystalline silicon is housed in an inner basket and packed in a bag, there is no danger that the sharp crushed end directly contacts the outer bag and breaks it, so that the reliability is high.

[Brief description of the drawings]

FIG. 1 is a perspective view of a container according to the present invention.

FIG. 2 is a perspective view of the container according to the present invention.

FIG. 3 is a perspective view of the container according to the present invention.

[Explanation of symbols]

 10, 16-Inner basket 11-Liquid hole 12, 17-Outer bag 14, 18-Lid material 13-Top opening 15-Peripheral edge

Claims (4)

(57) [Scope of request for utility model registration] 1. An inner basket for accommodating massive polycrystalline silicon, and an outer bag for accommodating the inner cage, wherein the inner cage is smaller than an average outer diameter of a projection at a crushed end of the polycrystalline silicon. A washing basket having a large number of liquid holes with a hole diameter is also used,
A container for storing polycrystalline silicon, wherein the outer bag is sealed in a state where bulk polycrystalline silicon having undergone a washing step is stored in an inner basket. 2. The container according to claim 1, wherein the inner cage is formed by a mesh member having a hole diameter smaller than the average outer diameter of the projection at the crushed end of the polycrystalline silicon. 3. A rib forming a space between the inner basket and the outer bag is formed on the outer surface of the inner basket.
The storage container according to 1. 4. The inner basket is formed so as to be able to be suspended with its opening side upward so as to wash the polycrystalline silicon while being housed in the inner cage, and the inner cage contains the washed polycrystalline silicon. The container according to claim 1, wherein the container is housed in an outer bag in a state, an upper end of the outer bag is heat-sealed, or an opening of the outer bag is closed by a lid material.