JP2000239094A - Crystal puller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make avoidable the breakage of a seed crystal or a holder therefor due to stress by limiting a housing part holding the seed crystal placed in the holder for seed crystal in a movable state in the axial direction with a supporting surface tapering off in a downward direction and by hanging the single crystal from the supporting surface. SOLUTION: A crystal block is joined with a seed crystal 7 held in the holder 2 for seed crystal through the neck part when a crystal is pulled. The holder 2 is provided with a bore 9 having a housing part 10 having a narrower part 11 in a lower section which has a supporting surface 12 directing itself upward so as to form a truncated cone. The seed crystal 7 has a head part 13 and it is placed above the surface 12. The height size of the head part 13 is smaller than that of the part 10 and therefore the head part 13 can move upward in the part 10 when force acts on the seed crystal 7 from its lower part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crystal pulling apparatus, comprising a seed crystal holder, which is connected to a vertically movable support mechanism. A support device is provided for supporting the crystal block, which can be moved synchronously with the crystal block, such that the crystal block is coupled via a neck to a seed crystal held by a seed crystal holder. About the format that is

[0002]

2. Description of the Related Art A crystal pulling apparatus of this type is shown, for example, in FIG. 6 of DE-2515850 and is described in detail in the description. The support device is designed to increase the length of the crystal block as it grows after the neck is pulled up, so that the total weight of the crystal block is not transmitted to the seed holder via the small diameter neck and from there to the further pulling shaft. Used to support heavier crystal blocks.

[0003] Instead of coupling the seed holder directly to the lifting shaft, as disclosed in said DE-2515850, the seed holder is often connected to the support mechanism by means of a rope, whereby: It can also be moved upward as the crystal grows.

In both the apparatus having the seed crystal holder fixed directly to the pulling shaft and the apparatus having the rope feed member, the supporting device is slightly moved relative to the seed crystal holder when it is applied to the crystal block. A problem arises in that it may move downward. The cause is
This may be due to undulations in the surface of the crystal block or to a method step in which the crystal is subjected to a compressive strain when the crystal is pulled. Movement of the support device downward relative to the seed holder may cause fracture stress at the seed neck, which may result in failure of the seed holder or the neck of the seed.

[0005]

An object of the present invention is to improve a crystal pulling apparatus of the type described at the outset,
It is an object of the invention to provide a device in which the danger of destruction caused by the movement of the support device relatively downwards with respect to the seed crystal holder can be avoided as much as possible.

[0006]

According to the present invention, in order to solve the above-mentioned problem, a seed crystal holder has a housing for holding a seed crystal movably in an axial direction. Is downwardly limited by the support surface,
The seed crystal was placed on the support surface from above.

[0007]

By configuring the seed crystal holder in this manner, the seed crystal is restricted within the seed crystal holder and can move upward when the support device moves downward when applied to the crystal block. It is. This avoids stress on the seed crystal and / or the seed crystal holder. This has eliminated the cause of the destruction in this area. Further, according to the present invention, the broken portion of the seed crystal and / or the neck portion is peeled off based on stress,
It is possible to prevent falling into the crucible as impurities. In addition, the free movement in the seed crystal holder according to the invention additionally avoids imbalances caused by bending, which prevents a reduction in the support of the crystal puller.

[0008] The support surface may be formed differently. In a very simple embodiment, the support surface is formed by a narrow part, in which the head of the seed crystal is mounted. This seed crystal must be inserted into the seed crystal holder from above in such an embodiment.

According to another feature of the invention, if the constriction is formed as a cone, the seed crystal is necessarily centered in the seed crystal after insertion.

If the support surface is provided on a support which engages with the reduced diameter portion of the seed crystal and which can be inserted as a separate component into the seed crystal holder, the insertion of the seed crystal from below or from the side Is possible.

In such an embodiment, the support is formed from two support plates inserted into the seed crystal holder, which engage the reduced diameter portion on opposite sides with respective semicircular notches. It is particularly simple if the two support plates are prevented from shifting in the radial direction by a locking sleeve which engages the seed crystal holder.

The invention is capable of various different embodiments. Two of these embodiments are shown in the drawings to further clarify the basic principles of the present invention.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a holder 1 according to the prior art, which has mainly a seed crystal holder 2 and a support device 3. The support 1 supports the crystal 4. This crystal 4 is composed of crystal blocks 5,
The crystal block 5 has a neck 6 when the crystal is pulled up.
To the seed crystal 7 via Seed crystal 7 itself is held in seed crystal holder 2. The seed crystal holder 2 is suspended by a rope 8 in this embodiment, and the rope 8 must be originally tensioned in order to support a part of the weight of the crystal 4 via the seed crystal 7. Must.
However, at the position shown, the rope is relaxed, whereby the seed crystal holder 2 is tilted and the neck 6 of the crystal block 5 is cut off from the seed crystal 7. Such disadvantages are:
For example, this occurs when the support device 3 slides downward relative to the seed crystal holder 2 when applied to the crystal block 5.

From the cross-sectional view of the seed crystal holder 2 shown in FIG. 2, it can be seen that the seed crystal holder 2 has a through hole 9 in which the accommodating portion 10 is provided. The housing 10 has a narrow section 11 in the lower section, the narrow section 11 having an upwardly directed support surface 12 formed by a cone. Seed crystal 7 has head portion 13, and head portion 13 of seed crystal 7 is placed on support surface 12. The head part 13 is not higher than the accommodation part 10, so that the seed crystal 7 can move upward in the accommodation part when a force acts from below.

FIG. 3 shows the seed crystal 7 pushed up inside the seed crystal holder 2. In this figure, it can be seen that the head part 13 is located in the upper section of the accommodation part 10.

The seed crystal holder 2 shown in FIGS. 4 to 6 is formed for a seed crystal 7 having a different structure from those of FIGS. Members functionally identical to FIGS. 2 and 3 are shown in FIGS.
In FIG. 6, the same member numbers are used. In this embodiment, the seed crystal 7 has a reduced diameter portion 14 below the head portion 13, and the support 15 is engaged with the reduced diameter portion 14. The support 15 is a support surface 12 for the head 13 of the seed crystal 7.
To form Since the seed crystal holder 2 is surrounded by the locking sleeve 16, the support 15 does not protrude sideways from the seed crystal holder 2. FIG. 4 shows the lower end of the pulling shaft of the support mechanism 17 above the seed crystal holder 2, and the seed crystal holder 2 is screwed to the support mechanism 17.

FIG. 5 shows the seed crystal 7 corresponding to FIG. 3 in a state of being pushed up inside the seed crystal holder 2.

In the enlarged cross-sectional view of FIG. 6, the support 15 consists of two support plates 18, 19 with semicircular notches 20, 21 inside the seed crystal holder 2, respectively. I understand. Each notch 20, 21 is a reduced diameter portion 14.
The support plates 18 and 19 are inserted into the slits 22 of the seed crystal holder 2 from each side so as to surround.

[Brief description of the drawings]

FIG. 1 is a schematic view of an important partial region of a crystal pulling apparatus according to the prior art.

FIG. 2 is a sectional view of a seed crystal holder according to the present invention into which a seed crystal has been inserted.

3 shows a sectional view of the seed crystal holder according to the invention according to FIG. 2 with the position of the seed crystal changed.

FIG. 4 is a sectional view of a second embodiment of a seed crystal holder according to the present invention into which a seed crystal has been inserted.

5 is a sectional view of the seed crystal holder according to the invention corresponding to FIG. 4 with the position of the seed crystal changed.

FIG. 6 is a horizontal sectional view of the seed crystal holder shown in FIGS. 4 and 5;

[Explanation of symbols]

1 holder, 2 seed crystal holder, 3 support device,
4 crystal, 5 crystal block, 6 neck,
7 seed crystals, 8 ropes, 9 holes, 10 storage units,
11 narrow part, 12 support surface, 13 head part,
14 diameter reduction part, 15 support base, 16 locking sleeve, 17 support mechanism, 18, 19 support plate, 20, 21 notch, 22 slit

Claims (5)

[Claims] 1. A crystal pulling apparatus, comprising: a seed crystal holder (2); wherein the seed crystal holder (2) is coupled to a vertically movable support mechanism; A support device (3) is provided for supporting a crystal block (5), which can move synchronously with the crystal block (5), said crystal block (5) being connected via a neck (6) to a seed crystal holder ( In a type adapted to be coupled to the seed crystal (7) held by 2), a seed crystal holder (2) for holding the seed crystal (7) movably in the axial direction. A receiving portion (10), the receiving portion (10) being limited downward by a support surface (12), and a seed crystal (7) being placed on the support surface (12) from above. A crystal pulling apparatus, characterized in that the crystal pulling apparatus is adapted to be used. 2. A support surface (12) is formed by a narrow portion (11), and a head portion (13) of a seed crystal (7) is placed on the narrow portion (11). 2. The crystal pulling apparatus according to claim 1, wherein 3. The crystal pulling device according to claim 2, wherein the constriction is formed as a cone. 4. A support (15) whose support surface (12) engages a reduced diameter portion (14) of a seed crystal (7), which can be inserted as a separate component into the seed crystal holder (2). The crystal pulling apparatus according to any one of claims 1 to 3, comprising: 5. Insertion into a seed crystal holder (2) in which a support (15) engages a reduced diameter section (14) on opposite sides with respective semicircular notches (20, 21). And the support plate (18, 19) is formed from the support plate (18, 19).
5. The crystal pulling device according to claim 4, wherein the device is prevented by a locking sleeve (16) engaging the seed crystal holder (2).