CN219032460U

CN219032460U - Graphite accessory of single crystal furnace

Info

Publication number: CN219032460U
Application number: CN202223593706.2U
Authority: CN
Inventors: 杨振远; 白俊鹏; 马长庆; 丁光明
Original assignee: Hebei Jingcarbon Technology Co ltd
Current assignee: Hebei Jingcarbon Technology Co ltd
Priority date: 2022-12-31
Filing date: 2022-12-31
Publication date: 2023-05-16
Anticipated expiration: 2032-12-31

Abstract

The utility model relates to a graphite accessory of a single crystal furnace, which comprises a spiral graphite body, wherein cylindrical extension parts are integrally connected to two ends of the graphite body, a circular ring-shaped ring seat is integrally connected to the outside of the extension parts, a plurality of graphite connecting pieces are connected to the ring seat, a step structure is arranged between the ring seat and the extension parts, and each graphite connecting piece comprises a stud and a nut matched with the stud. The graphite fitting of the single crystal furnace adopts the graphite body with the spiral structure, the heat productivity is larger, and the graphite fitting is of a smooth spiral structure, so that a region with lower temperature does not exist, the heat distribution in a thermal field is more uniform, and the drawing quality and the qualification rate of the single crystal silicon rod are improved.

Description

Graphite accessory of single crystal furnace

Technical Field

The utility model relates to a graphite accessory of a single crystal furnace, and belongs to the technical field of graphite products.

Background

In the solar photovoltaic industry, the quality of single crystals is directly related to the quality of single crystals, and qualified thermal fields can grow high quality single crystals. Therefore, there are very important factors in the Czochralski single crystal process to create good thermal field conditions. Graphite is a carrier for single crystal growth. The graphite is mainly prepared from high-purity graphite and an isostatic pressing graphite workpiece in a Czochralski crystal growing furnace (called a single crystal furnace for short).

According to practical conditions, the size of the graphite thermal field is divided according to the diameter of the crucible. Currently common graphite thermal fields range from phi 12 to phi 28, and generally include graphite crucibles, graphite support rods, graphite trays, heat shields, draft tubes, graphite compression rings, heaters, graphite electrodes, and the like. The graphite support rod and the graphite tray together form a support body of the graphite crucible, and are required to be firmly combined with the lower shaft. The heat shield is divided into an upper shield, a middle shield and a lower shield. The heat shield is formed by wrapping graphite carbon felt outside the heat preservation cylinder, and the number of layers of the wrapping graphite carbon felt is determined according to the situation. The graphite compression ring is a circular ring-shaped graphite sheet consisting of a plurality of circular arcs and is placed at the contact position of the cover plate and the furnace wall, so that heat and gas are prevented from passing through a gap between the fireplace and the cover plate. The heater is an important component in the thermal field and is a direct heater. The temperature can reach 1600 ℃ or more when the temperature is high. Common heaters have a cylindrical, cup-like, etc. shape. Typically, the heater is made of high purity graphite. The graphite electrode functions to stably fix the heater and transmit current through other devices.

The existing heater for graphite thermal fields is usually manufactured by processing whole graphite, most of the heater is of a cylindrical structure, a plurality of graphite blocks (equivalent to equivalent resistance) which are mutually connected are separated into graphite cylinders through a plurality of staggered separation grooves, the resistance value of the graphite cylinders is variable by changing the number of the graphite blocks, and different heating values are realized. For example, the patent name "a sleeve type graphite heater" (application number: CN 202010668575.6).

The disadvantage of the above heater is that there are areas of lower temperature, especially the notches, grooves bottoms, edges, etc., near the dividing grooves, which are evident from the ir thermography, where there are dark areas.

The existence of these dark areas causes the heater to heat the graphite thermal field, which may cause non-uniformity of some areas in the thermal field, thereby affecting the drawing quality and yield of the single crystal silicon rod.

Disclosure of Invention

Aiming at the defects existing in the prior art, the utility model provides a graphite accessory of a single crystal furnace, which has the following specific technical scheme:

the utility model provides a single crystal growing furnace graphite accessory, includes spiral helicine graphite body, the both ends integral connection of graphite body has cylindric extension, the outside integral connection of extension has the annular ring seat of circle, the ring seat is connected with a plurality of graphite connecting pieces, be provided with step structure between ring seat and the extension, graphite connecting piece includes double-screw bolt, with double-screw bolt assorted nut.

As an improvement of the technical scheme, a wire groove is formed in the inner wall of the graphite body along the spiral line of the graphite body.

As an improvement of the technical scheme, the depth of the wire groove is 3-5 mm, and the width of the wire groove is 2-3 mm.

As an improvement of the technical scheme, the inner wall of the extension part is provided with an internal thread, and the rotation direction of the internal thread is opposite to that of the graphite body.

As an improvement of the technical scheme, the end, connected with the extension part, of the ring seat is the head end of the ring seat, the tail end surface of the ring seat is provided with at least three fan-shaped open grooves, and the depth of the open grooves is sequentially reduced from the outer periphery of the ring seat to the inner periphery of the ring seat.

As an improvement of the technical scheme, five open slots are arranged, and the central angle corresponding to the open slots is 37 degrees.

As an improvement of the technical scheme, the tail end of the ring seat is also provided with screw holes matched with the studs.

The graphite fitting of the single crystal furnace adopts the graphite body with the spiral structure, the heat productivity is larger (compared with that of a common cylinder), and the graphite fitting is of a smooth spiral structure, so that a region with lower temperature does not exist, the heat distribution in a thermal field is more uniform, and the drawing quality and the qualification rate of a single crystal silicon rod are improved.

Drawings

FIG. 1 is a schematic structural diagram of a graphite fitting for a single crystal furnace according to the present utility model;

FIG. 2 is a schematic diagram of the connection of the graphite body and the ring base according to the present utility model;

FIG. 3 is a schematic view of the tail end of the ring seat according to the present utility model.

Detailed Description

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

In the description of the present utility model, it is to be noted that, unless otherwise indicated, the meaning of "plurality" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front," "rear," "head," "tail," and the like are used as an orientation or positional relationship based on that shown in the drawings, merely to facilitate description of the utility model and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the utility model. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

Example 1

As shown in fig. 1, the graphite fitting of the single crystal furnace comprises a spiral graphite body 10, cylindrical extending parts 11 are integrally connected to two ends of the graphite body 10, a circular ring-shaped ring seat 20 is integrally connected to the outside of the extending parts 11, a plurality of graphite connecting pieces are connected to the ring seat 20, a step structure is arranged between the ring seat 20 and the extending parts 11, and each graphite connecting piece comprises a stud 31 and a nut 32 matched with the stud 31.

The graphite body 10, the extension 11, the ring seat 20, the stud 31 and the nut 32 are all made of graphite by processing.

Since the graphite body 10 has a spiral structure, the heat generation amount is larger (than that of a normal cylindrical shape) like a cylindrical coil spring. Compared with the common cylindrical graphite heater, the cylindrical graphite heater has no abrupt separation grooves and is of a smooth spiral structure, so that a region with lower temperature does not exist.

The extension 11 serves as a transition portion connecting the graphite body 10 and the ring seat 20. The ring holder 20 may be connected to an electrode of a graphite thermal field by a graphite connection.

The outer diameter of the ring seat 20 is larger than the outer diameter of the extension 11, thus forming a stepped structure; thereby improving the stability of installation.

Example 2

Based on embodiment 1, as shown in fig. 2, the inner wall of the graphite body 10 is provided with a wire groove 101 along the spiral line of the graphite body 10.

The provision of the wire grooves 101 can further increase the heat generation amount. Heat is concentrated in the vicinity of the spiral-shaped graphite body 10, and heat waves are more easily formed, thereby improving uniformity of heat distribution in a thermal field.

Further, the depth of the wire groove 101 is 3-5 mm, and the width of the wire groove 101 is 2-3 mm.

The depth and width of the wire slot 101 are too large, the processing difficulty is increased sharply, and the qualification rate is reduced remarkably. The depth and width of the slot 101 are too small, and the effect of increasing the heat generation amount is limited.

Example 3

Based on embodiment 1, the inner wall of the extension 11 is provided with an internal thread having a direction opposite to that of the graphite body 10.

The provision of the internal thread allows the inner wall of the extension 11 to have a spiral groove, which can further increase the heat generation amount. And, the heat waves formed by the graphite body 10 can form opposite impact, so that the uniformity of heat distribution in the thermal field is better.

Example 4

Based on embodiment 1, as shown in fig. 3, the end of the ring seat 20 connected with the extension portion 11 is the head end of the ring seat 20, and the tail end surface of the ring seat 20 is provided with at least three fan-shaped open slots 22, and the depth of the open slots 22 decreases from the outer periphery of the ring seat 20 to the inner periphery of the ring seat 20.

The pattern enclosed by one circular arc and two radiuses passing through the two ends of the circular arc is called a sector. The sector shape is the sector shape.

The provision of the open slot 22 facilitates the flow of the air flow in the thermal field, and the variation in depth of the open slot 22 facilitates the formation of a pressure differential, accelerating the flow of the air flow, thereby providing better flowability in the thermal field and more uniform heat distribution.

The fan-shaped open slot 22 provides a better acceleration flow effect than a rectangular slot. The meaning of the groove with the arc-shaped structure at the two sides is not much different from that of the rectangular groove.

Example 5

Based on embodiment 4, as shown in fig. 3, the open slots 22 are provided with five, and the central angle corresponding to the open slots 22 is 37 °.

Due to the size limitation of the thermal field, the open slot 22 is preferably provided with five. If the number of the regions is six, the remaining area becomes small, and the stability of the thermal field becomes poor.

Similarly, if the central angle corresponding to the open slot 22 is too large, the effect of accelerating the air flow is poor; if too small, it will act like a rectangular slot. Therefore, through many experiments, the central angle corresponding to the final open groove 22 is preferably 37 °.

Example 6

The tail end of the ring seat 20 is also provided with a screw hole 23 matched with the stud 31. The stud 31 is screwed with the screw hole 23, then screwed with the screw hole on the electrode again by using the stud 31, and then reinforced by using the nut 32.

In the above embodiment, the graphite fitting of the single crystal furnace adopts the graphite body 10 with a spiral structure, the heat productivity of the graphite body is larger (than that of a common cylinder), and the graphite fitting is of a smooth spiral structure, so that a region with lower temperature does not exist, the heat distribution in a thermal field is more uniform, and the drawing quality and the qualification rate of the single crystal silicon rod are improved (the qualification rate is improved from 86.3% to 95.7%).

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims

1. The utility model provides a single crystal growing furnace graphite accessory which characterized in that: including heliciform graphite body (10), the both ends integral connection of graphite body (10) has cylindric extension (11), the outside integral connection of extension (11) has annular ring seat (20), ring seat (20) are connected with a plurality of graphite connecting pieces, be provided with step structure between ring seat (20) and extension (11), graphite connecting piece includes double-screw bolt (31), with double-screw bolt (31) assorted nut (32).

2. The single crystal furnace graphite fitting according to claim 1, wherein: the inner wall of the graphite body (10) is provided with a wire groove (101) along the spiral line of the graphite body (10).

3. The single crystal furnace graphite fitting according to claim 2, wherein: the depth of the wire groove (101) is 3-5 mm, and the width of the wire groove (101) is 2-3 mm.

4. The single crystal furnace graphite fitting according to claim 1, wherein: the inner wall of the extension part (11) is provided with an internal thread, and the rotation direction of the internal thread is opposite to that of the graphite body (10).

5. The single crystal furnace graphite fitting according to claim 1, wherein: the end of the ring seat (20) connected with the extension part (11) is the head end of the ring seat (20), the tail end surface of the ring seat (20) is provided with at least three fan-shaped open grooves (22), and the depth of the open grooves (22) is sequentially reduced from the outer periphery of the ring seat (20) to the inner periphery of the ring seat (20).

6. The single crystal furnace graphite fitting according to claim 5, wherein: five open slots (22) are arranged, and the central angle corresponding to the open slots (22) is 37 degrees.

7. The single crystal furnace graphite fitting according to claim 1, wherein: the tail end of the ring seat (20) is also provided with a screw hole (23) matched with the stud (31).