JP2565759B2 - Equipment for crushing polycrystalline silicon - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of use> The present invention relates to a device for pressing cylindrical polycrystalline silicon between high-purity silicon to crush it.

<Prior arts and problems> There are CZ method and FZ method for producing single crystal silicon from polycrystalline silicon. In CZ method, cylindrical polycrystalline silicon produced by Siemens method has an appropriate size. Crush into pieces and dissolve in a quartz crucible, attach seed crystals to the liquid surface and pull up. That is, in the CZ method, the purity and particle size distribution of the crushed polycrystals have an important influence on the obtained single crystal. Therefore, a method and apparatus for crushing a cylindrical polycrystal is extremely important.

Regarding the method and apparatus for crushing cylindrical or massive polycrystalline silicon, (1) cutting into an appropriate size with a device using a diamond blade, (2) utilizing the relatively brittle nature of silicon For example, mechanical crushing is performed by a crushing device such as a jaw crusher, (3) crushing is performed by rapidly cooling high temperature silicon and utilizing thermal stress. However, in the above means (1) and (2), it is inevitable that impurities are mixed in due to wear and damage of the equipment and materials, and a step of removing impurities is necessary. Further, in the method (2), it takes a long time to cut. Further, in the method (3), since the high temperature treatment (600 to 750 ° C.) is performed, the silicon is contaminated by the high temperature treatment apparatus or the high temperature treatment. There is also a problem that it is difficult to control the crushed particles. As described above, the conventional method of crushing requires a washing step of crushed silicon.

<Means for Solving Problems> In order to solve the problems of the above-mentioned conventional method, the present invention sandwiches cylindrical or lump polycrystal silicon between high-purity silicon and presses a variable pressure and angle mechanism. The polycrystalline silicon is crushed by pressing with a device having.

That is, according to the present invention, (1) a crushing surface that is formed by closely arranging cylindrical high-purity polycrystalline silicon in close contact with each other is provided, and a mechanism that moves and presses both crushing surfaces, Provided is a crushing device for polycrystalline silicon, which has a mechanism for changing the angle of the crushing surface, and presses the columnar or lumpy polycrystalline silicon charged between the crushing surfaces by the crushing surfaces. .

Further, according to the present invention, as a preferred embodiment thereof, (2) the supports are provided so as to face each other, and the column-shaped high-purity polycrystalline silicon is closely arranged in parallel to both the supports. A crushing surface is formed, and pressing means for moving the supporting body are respectively connected to the upper and lower portions of at least one supporting body, and the pressing means is pivotally attached to the supporting body in a tiltable manner. The crushing device according to (1) is provided in which both crushing surfaces are pressed by the pressing means and the inclination is adjusted.

<Detailed Description> The present invention will be specifically described with reference to the drawings. As shown in FIG. 1, between the crushing surfaces 10 and 11 formed of the columnar high-purity polycrystalline silicon 2 arranged in close contact with the support 7, the columnar or massive polycrystalline silicon to be crushed. 3 is thrown in. At this time, the particle size distribution of the polycrystalline silicon crushed pieces is controlled by adjusting the clearance 8 under the crushed surfaces 10 and 11. The crushing surfaces 10 and 11 of the support 7 are pressing mechanisms 4
The clearance 8 is movably supported by a, 4b and 6, and the clearance 8 is adjusted by fixing the crushing surface 11 in FIG. 1 and moving the crushing surface 10. After the polycrystalline silicon is charged, the upper pressing mechanism 4a of the crushing surface 11 is moved while the lower pressing mechanism 4b of the crushing surface 11 and the crushing surface 10 is fixed. This makes the second
As shown in FIG. 3B, the injected polycrystalline silicon is pressed and crushed on both crushing surfaces. Next, with the upper part of the crushing surface 10 fixed, the lower pressing mechanism 4b of the crushing surface 10 is moved to open the lower parts of both the crushing surfaces 10 and 11 as shown in FIG. Drop it into the receiver. After that, the upper part of the crushing surface 10 is opened as shown in FIG.
The clearance is adjusted as described above and the next pressure crushing step is started.

The cylindrical high-purity polycrystalline silicon used for forming the crushed surface in the present invention is manufactured by the Siemens method.

The pressure crusher of the present invention is shown in more detail in FIGS. 3 and 4. The device has a box-shaped frame 31. Inside the frame 31, a pair of supports 37, 38 are installed facing each other. The upper part of the one support 37 is connected to the pressing mechanism 44a, and the lower part of the support 37 is connected to the pressing mechanism 44b. As the pressing mechanisms 44a and 44b, appropriate means such as a hydraulic cylinder can be adopted. Both pressing mechanisms 44a and 44b are pivotally mounted so that the support 37 can be tilted. Meanwhile support 38
Is supported by a rod 36, and its inclination is finely adjusted by the rotation of the rod 36.

Cylindrical high-purity silicon 32 is juxtaposed on both opposing surfaces of both the supports 37, 38 to form crushed surfaces.
The cylindrical silicon 32 may be arranged vertically or horizontally. Further, cylindrical high-purity silicon 39 is provided between the both ends of the supports 37, 38 and the frame 31 so as to surround the side of the crushing surface.

On the other hand, above the supports 37, 38, there is provided a hopper 41 for introducing the polycrystalline silicon to be crushed, and below the supports 37, 38, the crushed polycrystalline silicon pieces are stored. A receiver 45 is provided.

In the above structure, when the crushed polycrystalline silicon is introduced between both crushed surfaces, the crushed polycrystalline silicon crushed pieces are crushed as shown in FIGS. 2 (A) to (D), and have a proper particle size. Becomes

<Effects of the Invention> Since the polycrystalline silicon particles obtained by the device of the present invention use high-purity silicon for the crushing surface, impurities are not mixed during crushing. Therefore, the step of removing impurities is unnecessary. Further, the time can be significantly shortened as compared with the conventional cutting method. Also, by adjusting the spacing of the crushing surface,
Polycrystalline silicon having an appropriate particle size can be obtained.

As described above, according to the present invention, it is possible to efficiently obtain high-purity polycrystalline silicon as a raw material for producing a CZ single crystal silicon with a desired particle size distribution.

<Example> Example 1 A crushing device of the present invention shown in FIGS.
A columnar polycrystalline silicon having a length of 250 mm was charged and the columnar polycrystalline silicon was pressed and crushed. When the clearance at the bottom of both crushed surfaces was 22 mm, the distribution of the particle shape of the crushed pieces dropped was as shown in Fig. 5. The crushing time and the yield of crushed polycrystalline silicon at this time are shown in Table 1.

Example 2 With the same apparatus and operating procedure as in Example 1, the crushed polycrystalline silicon having a size of 100 to 150 mm was pressed and crushed, and the particle size distribution when the clearance under both crushed surfaces is 38 mm is shown in FIG. It seemed. The yield of the crushed polycrystalline silicon and the crushing time at this time are shown in Table 1. In addition, the silicon obtained in both Examples 1 and 2 was free from contamination and did not require a washing step.

Comparative Example Cylindrical polycrystalline silicon (diameter 120 mm) was cut into a length of 185 mm with a conventional cutting device equipped with a diamond blade, and cutting time and yield were compared in Table 1. The obtained silicon was contaminated with water such as diamond blades and water at the time of cutting, and a washing step was required to use it for CZ method single crystal production.

[Brief description of drawings]

FIG. 1 is a schematic view of a cylindrical polycrystalline silicon pressing and crushing device according to the present invention, and FIGS. 2 (A), (B), (C) and (D).
Is a schematic view showing the operation sequence of the apparatus, FIG. 3 is a plan view of the apparatus, FIG. 4 is an elevation view of the apparatus, FIG. 5 is a particle size distribution of the crushed pieces of Example 1, and FIG. 6 is Example 2. It is a particle size distribution diagram of the crushed pieces in. 1 ... Polycrystalline silicon input port, 2,32,39 ... Cylindrical high-purity silicon, 3 ... Crushed polycrystalline silicon, 4a, 4b, 44a,
44b …… Pressing mechanism, 5,45 …… Silicon fragment receiver, 6,36
…… Rod, 7,37,38 …… Supporting body, 8 …… Clearing, 10,11 …… Crushing surface.

Claims (2)

(57) [Claims] 1. A crushing surface, which is formed by closely arranging cylindrical high-purity polycrystalline silicon closely in parallel, is provided, and a mechanism for moving and pressing both crushing surfaces and an angle of the crushing surface are changed. A crushing device for polycrystalline silicon, which has a mechanism and crushes cylindrical or lump-shaped polycrystalline silicon charged between both crushing surfaces by pressing with both crushing surfaces. 2. A crushing surface in which cylindrical high-purity polycrystalline silicon is closely arranged in parallel is formed on both of the supports, and the supports are provided so as to face each other. Pressing means for moving the supporting body are connected to the upper and lower portions of the supporting body, and the pressing means is pivotally attached to the supporting body so that both crushing surfaces are pressed and tilted by the pressing means. The crushing device according to claim 1, wherein