DE19608375A1 - Single crystal pulling apparatus permits rapid and shudder-free closure of the opening at lock chamber base - Google Patents

Abstract

In a single crystal pulling apparatus having a pulling element (4), which pulls the crystal upwards from the melt surface in a vacuum chamber (3) into a lock chamber (6), and a valve disc (7), which swivels between the lock chamber and the vacuum chamber to effect vacuum-tight separation of the chambers, the valve disc (7) is articulated to a longitudinally displaceable shaft (29) which is swivel mounted in a vertical sleeve (30) held by the lock chamber (6). A transverse bore in the upper part of the shaft (29) receives a crossbar (31) which has, at one end, a roller (32) with a rotational axis parallel to but offset from the longitudinal axis of the crossbar and which is fixed, at the other end, to a handle (33). The handle permits turning of the crossbar (31) about its longitudinal axis as well as swivelling of the shaft (29), together with the connected valve disc (7), about the vertical axis (17) of the shaft (29), while the roller (32) rolls on the upper horizontal peripheral edge (34) of the sleeve (30).

Description

The invention relates to a device for pulling of single crystals from a be in a crucible sensitive melt under vacuum or under Shielding gas at reduced pressure, using the crucible arranged in a vacuum chamber and through the Heat radiation from a heating element is heatable and with a pulling element above the melt is provided with which the crystal of the Melt surface from up to into one Lock chamber can be pulled out, as well as with a Valve plate between the lock chamber and the vacuum chamber is pivotable and the vacuum tight separation of the lock chamber from the vacuum Chamber allowed.

Usually in the lock chamber on Hanging crystal after closing the seed Lock between the lock chamber and the Va  vacuum chamber from a special handling system by one provided on the lock chamber gripped side opening, then from the vaccinated separated and finally with the help of the handling stems from this lockable by a flap Opening from the side of the lock chamber drive.

Closing the between the vacuum chamber and the lock chamber provided opening happens usually with the help of a valve cover, the with the help of a hydraulic cylinder vertically and with another hydraulic cylinder horizontally is movable. Such lock constructions However, are expensive to manufacture, too their space requirement is large, since this is a larger one Number of items is required.

The object of the present invention is to achieve reasons, a device of the aforementioned Type so that for the purpose of removal of the finished crystal the opening at the bottom part the lock chamber or in the vacuum chamber above half of the melting pot quickly and shake can be closed without stanchions. The lock is supposed to also be inexpensive to manufacture and without complex hydraulic or electronic drive be get along.

According to the invention, this object is achieved by that the valve plate is articulated on a shaft, those in a lock chamber, vertically aligned sleeve can be swiveled and rotated  is mounted, in the upper part of the shaft a bore extending transversely to it Gag is arranged at one end Slider or a roller is rotatably mounted, whose axis of rotation parallel to the longitudinal axis of the Kne bels, but runs a distance from it, and the other end firmly with a handpiece connected, which is both turning the toggle about its longitudinal axis as well as pivoting the Wave around a vertical axis with the ver bound valve cover allowed, the roll on the upper one, run in a horizontal plane rolls the edge of the sleeve.

Further details and features can be found in Pa claims described and characterized in more detail net.

The invention allows a wide variety of designs opportunities for; one of them is in the an hanging drawings shown in more detail demonstrate:

Fig. 1 is a longitudinal section with a chamber disposed therein and the pipe piece on the housing of senkammer Schleu fixed lifting and pivoting apparatus by a locks as well as lock chamber cover and the valve plate,

Fig. 2 shows the longitudinal section through the lifting and pivoting device according to FIG. 1 and

Fig. 3 is a plan view of the device of FIG. 2 and

Fig. 4 shows the perspective view of the device according to FIGS. 1 and 2 highly schematic.

The device consists essentially of the lock chamber 6 with flap or chamber door 12 , the laterally arranged on the lock chamber 6 lifting and swiveling device 16 with lifting arm 21 and valve cover 7 , the four on the valve cover 7 four bolts 14 , 14 '; 15 , 15 ', the supported on the support bolt or resting profile sections or support strips 8 , 9 , the up on the lock chamber door 12 on hooks 22 , 23 hanging pipe or support sleeve 13 and the supported on the cylindrical side wall part of the vacuum chamber 3 vacuum chamber cover.

In the device described here is a support device in Ge stalt the profile blanks 8, 9 from heat-resistant gem and for contact with the crystal 5 suitable material on the valve plate 7 on accordingly provided support bolts 14 , 14 'when charging. 15 , 15 'abge sets and brought into the open position. Then the pipe section 13 , also made of heat-resistant and suitable for contact with the crystal 5 , is hung on the inside of the lock door 12 on the hooks 22 , 23 provided for this purpose and pivoted into the middle of the lock chamber when it is closed.

The pulling process is carried out in the usual manner, with the growing crystal 5 being automatically drawn into the tube piece 13 with the aid of the pulling element 4 . After driving through the Ventilöff opening 37 , this can be closed. Who who when swiveling the valve plate 7, the pro filschnnitte or support strips 8 , 9 in corre sponding recesses 10 , 11 of the pipe section 13 leads. During the subsequent lowering of the Ventiltel lers 7 , the profile cuts 8, 9 automatically center in the recesses 10 , 11 and are finally from the bolts 14 , 14 '; 15 , 15 'abgeho ben. Now the feed is moved downwards until the crystal tip dips into the recesses 18 , 19 of the profile blanks 8 , 9 . The position of the crystal tip is monitored in the sight glass 24 of the lock door 12 or with the aid of a light barrier.

The lifting and pivoting device 16 consists of the sleeve 30 mounted in the housing part 28 with a shaft or bushing 29 which is rotatably and pivotably held therein and which is provided at its upper end with a transverse bore in which a toggle 31 is rotatably held. This gag 31 is at its one end with a roller 32 or a rolling body which is rotatably gela in a pin whose longitudinal axis D 1 is arranged parallel to the longitudinal axis D 2 of the gag 31 . The opposite end of the toggle 31 is provided with a handpiece 33 , which is used for easy handling of the toggle 31 or the shaft or bush 29 connected to it. The gag 31 is also provided with a lock 35 in the form of a spring-loaded pin 36 . This Ar retention 35 makes it possible to prevent the lever 31 from rotating about its longitudinal axis D 2. On the other hand, the bolt 36 of the lock 35 in its upper position, then the toggle can be rotated in the direction of arrow G, with the result that the rolling element or the roller 32 lifts the shaft 29 into an upper position, thereby simultaneously the valve plate 7 is raised, which is connected to the shaft 23 via the support arm 21 . If the toggle 31 is pivoted in the direction of the arrow H, the valve 7 also moves out of the area of the lock opening 37 .

Reference list

3 vacuum chamber
4 pulling element
5 crystal
6 lock chamber
7 valve plates
8 profile cut, support bar
9 profile cut, support strip
10 recess
11 recess
12 lock chamber door
13 pipe section, support sleeve
14 , 14 ' bolts, support bolts
15 , 15 ′ bolts, support bolts
16 lifting and swiveling device
17 swivel axis
18 frustoconical depression
19 frustoconical depression
20 vacuum chamber covers
21 lifting arm
22 hooks
23 hooks
24 sight glass
25 seed crystal holder
26 opening
27 lasers
28 Housing of the swivel device
29 shaft, socket
30 sleeve
31 gags
32 roll
33 handpiece
34 sleeve edge
35 lock
36 bolts
37 lock opening

Claims (3)

1. Apparatus for pulling single crystals from a melt located in a crucible under vacuum or under a protective gas at reduced pressure, the crucible being arranged in a vacuum chamber ( 3 ) and being heatable by the heat radiation of a heating element and wherein a pulling element ( 4 ) is provided above the melt, with which the crystal ( 5 ) can be pulled upwards from the melt surface into a lock chamber ( 6 ), and with a valve plate ( 7 ), which is located between the lock chamber ( 6 ) and the vacuum chamber ( 3 ) is pivotable and the vacuum-tight separation of the lock chamber ( 6 ) from the vacuum chamber ( 3 ), characterized in that the valve plate ( 7 ) is articulated to a shaft ( 29 ) which is in one of the lock chamber ( 6 ) held, vertically aligned sleeve ( 30 ) is pivotally and longitudinally displaceable, wherein in the upper part of the shaft ( 29 ) in a bore extending transversely to a Kn ebel ( 31 ) is arranged, at one end a roller ( 32 ) is rotatably mounted, the axis of rotation (D¹) parallel to the longitudinal axis (D²) of the toggle ( 31 ), but offset by a dimension (a) to it, and the other end of which is firmly connected to a handpiece ( 33 ) which both rotates the toggle ( 31 ) about its longitudinal axis (D²) and swivels the shaft ( 29 ) together with the valve cover ( 7 ) connected to it around the vertical axis ( 17 ) of the shaft ( 29 ), the roller ( 32 ) rolling on the upper horizontal peripheral edge ( 33 ) of the sleeve ( 30 ). 2. Device according to claim 1, characterized in that the movable on the housing ( 28 ) of the lock chamber ( 6 ) mounted shaft ( 29 ) has a locking device ( 35 ), the bolt ( 36 ) with a recess or recess of the toggle ( 31 ) cooperates and a rotation of the toggle ( 31 ) about its longitudinal axis (D²) he enables or blocks. 3. Device according to claims 1 and 2, characterized in that the rolling element or the roller ( 32 ) rolls in a backdrop which is cut into the side wall of the fixed sleeve ( 30 ) at its upper end.