A furnace bottom insulation device for the hot zone of a Czochralski single crystal furnace

Abstract

This utility model relates to a furnace bottom insulation device for a Czochralski single crystal furnace, belonging to the field of single crystal furnace ingot production technology. It includes an insulation body composed of an insulation felt, an insulation cover, and a shield. The insulation cover is mounted on the upper surface of the insulation felt, and the shield is mounted on the upper surface of the arc-shaped insulation cover. The insulation body has vertically arranged gas channels, electrode channels, and support rod channels. The support rod channels are located in the middle of the insulation body, and the gas channels are symmetrically arranged on both sides of the support rod channels. An extension cylinder is installed inside the gas channels. The electrode channels are located at the edge of the insulation body and are adapted to the electrodes on the heater in the hot zone. The shield has a spliced ​​arc-shaped structure composed of multiple shield bodies. Through holes are opened in the middle of the shield and the insulation cover. A downwardly recessed isolation groove is provided in the through hole of the shield, and a circular hole for the support rod to pass through is provided in the middle of the isolation groove. This device has a simple structure, is easy to use, effectively increases the furnace bottom insulation performance, and achieves the purpose of reducing the power consumption of the single crystal furnace.

Description

Technical Field

[0001] This utility model relates to a furnace bottom insulation device, specifically a furnace bottom insulation device for the hot zone of a Czochralski single crystal furnace, belonging to the field of single crystal furnace ingot production technology. Background Technology

[0002] In recent years, the production of monocrystalline silicon wafers has increased significantly and steadily. This growth is due to two main reasons: firstly, the increasing international demand for low-end and inexpensive silicon materials; and secondly, the rapid development of equipment manufacturing and the strong demand for various information appliances and communication products. As a result, the market demand for semiconductor devices and silicon materials is very large. Monocrystalline silicon rods are the raw materials for producing monocrystalline silicon wafers. With the rapid increase in the demand for monocrystalline silicon wafers, the market demand for monocrystalline silicon rods is also showing a rapid growth trend.

[0003] In the manufacturing process of monocrystalline silicon rods, the monocrystalline furnace is the main equipment. The monocrystalline furnace is generally composed of a heater, a heat preservation cylinder, a graphite electrode, a graphite support bowl, and a graphite support rod. In the production process of straightening monocrystalline furnace, in addition to the cost of raw materials and crucibles, electricity consumption is also a major part of the production cost. With increasingly fierce competition in the photovoltaic monocrystalline market, cost reduction has become an effective measure to increase market competitiveness.

[0004] In existing technologies, a curing felt is placed at the bottom of the furnace, and 5 to 12 layers of soft felt are placed on top of the curing felt to provide sufficient heat insulation. Although this method can meet the heat insulation requirements of the thermal field and reduce energy consumption, in the actual crystal pulling process, the soft felt will pulverize at high temperatures due to the insulation fibers, especially at the exhaust vents and the electrode holes at the bottom of the furnace. The pulverization of the soft felt will gradually reduce its heat insulation performance, resulting in large fluctuations in the main power during the crystal pulling process, which will cause certain difficulties to the crystal pulling process. Moreover, the current mainstream single crystal furnace thermal field is a 36-inch thermal field, and its internal space is basically saturated. It is difficult to achieve the goal of reducing energy consumption by increasing the proportion of thermal insulation material in the thermal field under this thermal field condition.

[0005] Currently, patent CN202164376U describes a thermal field device for reducing energy consumption in single crystal furnaces, including a furnace bottom plate and a furnace bottom pressure plate. An insulating pressure plate is installed on the furnace bottom pressure plate, and an insulating felt is installed between the insulating pressure plate and the furnace bottom pressure plate. This fully utilizes the unused space between the furnace bottom pressure plate and the heater feet to reduce energy consumption through heat preservation. However, the insulating pressure plate in this thermal field device is relatively thin, and its planar structure cannot adapt to the shape of the crucible bottom, so its heat preservation performance needs to be improved. If the insulating pressure plate and the furnace bottom pressure plate are damaged, they need to be replaced, which is troublesome to repair and replace. The lack of protection at the opening of the heater feet will affect the insulating felt.

[0006] Therefore, developing a furnace bottom insulation device for the hot zone of a Czochralski single crystal furnace that can overcome the above defects has become a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0007] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a furnace bottom heat preservation device for the hot zone of a Czochralski single crystal furnace. The device has a simple structure, is easy to use, and effectively increases the heat preservation performance of the furnace bottom, thereby reducing the power consumption of the single crystal furnace.

[0008] To solve the above technical problems, this utility model provides a furnace bottom insulation device for the hot zone of a Czochralski single crystal furnace, which is installed at the furnace bottom and includes an insulation body. The insulation body is composed of an insulation felt, an insulation cover and a shield. The insulation felt is provided with an insulation cover on its upper surface. The upper surface of the insulation cover is a concave arc-shaped structure. The upper surface of the arc-shaped insulation cover is covered with a shield.

[0009] The insulation body is vertically provided with gas channels, electrode channels and support rod channels along the axis of the insulation body. The support rod channels are located in the middle of the insulation body for the support rods of the single crystal furnace to pass through. The gas channels are symmetrically arranged on both sides of the support rod channels. An extension cylinder is provided in the gas channel. The extension cylinder is connected to the gas guide cylinder set at the bottom of the furnace. Multiple electrode channels are located at the edge of the insulation body and are adapted to the electrodes on the heater in the hot field for the placement of electrodes.

[0010] The shield is a spliced ​​arc structure made up of multiple shield bodies. The shield and the heat insulation cover have through holes in the middle. The shield has a downwardly recessed isolation groove in the through hole, and the middle of the isolation groove has a round hole for the support rod to pass through.

[0011] The further defined technical solution of this utility model is:

[0012] Furthermore, in the aforementioned furnace bottom insulation device for the hot zone of the Czochralski single crystal furnace, an electrode cover is provided in the electrode channel. The electrode cover consists of a vertical protective wall and a horizontal protective wall connected to each other. The vertical protective wall is set to fit the electrode channel of the insulation body and covers the exposed parts of the insulation cover, shield and insulation felt in the electrode channel. The horizontal protective wall is set horizontally in the electrode channel and is flush with the bottom of the insulation felt. Electrode holes for electrodes to pass through are opened on the horizontal protective wall.

[0013] Technically, this utility model provides an electrode cover within the electrode channel to cover the exposed insulation felt, effectively protecting the insulation felt at the electrode and preventing leakage. This prevents the insulation felt at the electrode hole from pulverizing and gradually reducing its insulation properties, which in turn leads to significant fluctuations in the main applied power during crystal pulling, posing a certain degree of difficulty to the crystal pulling process. The electrode cover effectively solves the above problems.

[0014] Preferably, the baffle is composed of four baffle bodies spliced ​​together.

[0015] In terms of technical benefits, this utility model is constructed by splicing together the cover plate body, which facilitates installation and disassembly, and allows for individual replacement and maintenance, thus saving costs.

[0016] In the aforementioned furnace bottom insulation device for the Czochralski single crystal furnace, the extended cylinder is located at the splicing point of the shield body, and the upper surface of the extended cylinder is flush with the surface of the shield body.

[0017] In terms of technical benefits, the extended cylinder of this utility model facilitates the installation, disassembly, and replacement of the extended cylinder at the splicing point, improving work efficiency. The flat surface will not affect the crucible, ensuring stable heat preservation.

[0018] Preferably, the number of layers of the thermal insulation felt is set to 8.

[0019] Technically, this invention maintains the same total height of the thermal field and the same distance between the lid and the container, but by increasing the number of insulation layers, it can improve the insulation effect.

[0020] The beneficial effects of this utility model are:

[0021] This utility model is equipped with corresponding gas channels, electrode channels and support rod channels, and is equipped with corresponding extension tubes, electrode covers and isolation grooves. This split connection structure means that when it is damaged during use, only some damaged parts need to be replaced. It is easy to install, disassemble and maintain, thereby reducing the cost of using the thermal field.

[0022] After the bottom insulation of the single crystal furnace is installed, an insulation felt is installed to enhance the bottom insulation performance. Since the insulation felt is a flat needle-punched soft felt, an arc-shaped insulation cover is installed at the bottom to make full use of the furnace space. The insulation cover effectively prevents the insulation felt from pulverizing. A spliced ​​baffle is set on the insulation cover to protect it and allow for individual replacement and maintenance. The arc structure also ensures the flow of argon gas. To adapt to the crucible lifting device support rod of the single crystal furnace and prevent the soft felt from leaking out, an isolation groove is installed. To ensure the flow of argon gas and protect the soft felt at the gas guide hole, an extension cylinder is installed above the original gas guide cylinder at the bottom of the furnace. To protect the insulation felt at the electrode and prevent the insulation felt at the electrode from leaking out, an electrode cover is installed. Compared with the original furnace bottom insulation, this utility model can enhance the insulation performance, reduce the power consumption of single crystal furnace crystal pulling and equal diameter operation, and reduce the power consumption of single crystal furnace. The actual reduction in furnace platform crystal pulling and equal diameter operation power is 4 kW. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the furnace bottom insulation device for the Czochralski single crystal furnace of this utility model;

[0024] Figure 2 This is a schematic diagram showing the operation of the furnace bottom insulation device in the Czochralski single crystal furnace.

[0025] Figure 3 for Figure 1 Schematic diagram of the structure of the central insulation cover;

[0026] Figure 4 for Figure 1 Schematic diagram of the structure of the central isolation channel;

[0027] Figure 5 for Figure 1 Schematic diagram of the middle shield;

[0028] Figure 6 for Figure 1 Schematic diagram of the structure of the middle electrode cover;

[0029] Figure 7 for Figure 1 A schematic diagram of another type of electrode cover;

[0030] Figure 8 for Figure 1 Schematic diagram of the structure of the long cylinder in the middle;

[0031] In the diagram: 1-Insulation felt, 2-Insulation cover, 3-Isolation trough, 4-Electrode cover, 41-Vertical protective wall, 42-Horizontal protective wall, 6-Blinding plate, 7-Extended cylinder, 8-Lifting device, 9-Air guide cylinder. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them; the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example 1

[0033] See Figure 1-3 This embodiment provides a furnace bottom insulation device for the hot zone of a Czochralski single crystal furnace, which is installed at the furnace bottom and includes an insulation body. The insulation body consists of an insulation felt 1, an insulation cover 2, and a shield 6. The insulation felt 1 is provided with 8 layers, and the insulation cover 2 is provided on its upper surface. The upper surface of the insulation cover 2 has a concave arc-shaped structure to ensure a safe distance when the crucible is at the lower limit position while argon gas is flowing. The upper surface of the arc-shaped insulation cover 2 is covered with a shield 6. The shield 6 is adapted to the bottom arc-shaped insulation and is designed in an arc shape to ensure a safe distance when the crucible is at the lower limit position while argon gas is flowing.

[0034] The thickness of the curved structure of the insulation cover is 10-100mm, with the thickest part being 100mm and the thinnest part being 10mm. Designing the insulation cover to have a certain thickness can extend its service life to a certain extent and increase the protection of the insulation felt.

[0035] See Figure 1 , Figure 2 and Figure 8 The insulation body is vertically provided with gas channels, electrode channels and support rod channels along the axis of the insulation body. The support rod channel is located in the middle of the insulation body for the support rod of the single crystal furnace to pass through. Two gas channels are symmetrically arranged on both sides of the support rod channel. An extension cylinder 7 is provided in the gas channel. The extension cylinder 7 is connected to the gas guide cylinder 9 set at the bottom of the furnace. The extension cylinder is extended above the gas guide cylinder to adapt to the bottom arc insulation and protect the insulation felt. The extension cylinder 7 is located at the splice of the baffle body. The upper surface of the extension cylinder 7 is flush with the surface of the baffle body. Four electrode channels are located at the edge of the insulation body and are adapted to the electrodes on the heater in the hot field for the placement of electrodes.

[0036] See Figure 1 , Figure 4 and Figure 5 The shield 6 is a spliced ​​arc structure composed of four shield bodies. The shield 6 and the insulation cover 2 have through holes in the middle. The shield 6 has a downwardly recessed isolation groove 3 in the through hole. The isolation groove extends into the through hole of the insulation cover and reaches the surface of the insulation felt. That is, there is a hole in the middle of the insulation cover that directly holds the isolation groove. In this way, the isolation groove and the insulation cover both fall on the same surface of the insulation felt. The middle of the isolation groove 3 has a round hole for the support rod to pass through.

[0037] See Figure 6 and 7 The electrode channel is designed according to the structure of the electrode feet on the heater, and the shape may vary. The electrode cover 4 inside the electrode channel is designed according to the structure of the electrode channel. The electrode cover 4 consists of a vertical protective wall 41 and a horizontal protective wall 42 connected to each other. The vertical protective wall 41 is set to fit the electrode channel of the heat preservation body and covers the exposed parts of the heat preservation cover 2, the shield 6 and the heat preservation felt 1 in the electrode channel. The horizontal protective wall 42 is set horizontally in the electrode channel and is flush with the bottom of the heat preservation felt 1. The horizontal protective wall 42 has electrode holes for the electrodes to pass through.

[0038] In addition to the embodiments described above, this utility model may have other implementations. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by this utility model.

Claims

1. A furnace bottom insulation device for the hot zone of a Czochralski single crystal furnace, disposed at the furnace bottom, characterized in that: The insulation body is composed of an insulation felt (1), an insulation cover (2) and a shield (6). The insulation felt (1) has the insulation cover (2) on its upper surface. The upper surface of the insulation cover (2) is a concave arc-shaped structure. The shield (6) is provided on the upper surface of the arc-shaped insulation cover (2). The insulation body is vertically provided with a gas channel, an electrode channel and a support rod channel along the axial direction of the insulation body. The support rod channel is located in the middle of the insulation body for the support rod of the single crystal furnace to pass through. The two gas channels are symmetrically arranged on both sides of the support rod channel. An extension tube (7) is provided in the gas channel. The electrode channel is located at the edge of the insulation body for the placement of electrodes. The shield (6) is an arc-shaped structure made up of multiple shield bodies. The shield (6) and the heat insulation cover (2) have through holes in the middle. The shield (6) has a downwardly recessed isolation groove (3) in the through hole. The isolation groove (3) has a round hole in the middle for the support rod to pass through.

2. The furnace bottom insulation device for the Czochralski single crystal furnace according to claim 1, characterized in that: The electrode channel is provided with an electrode cover (4). The electrode cover (4) is composed of a vertical protective wall (41) and a horizontal protective wall (42) connected to each other. The vertical protective wall (41) is set to fit the electrode channel of the heat insulation body and covers the exposed parts of the heat insulation cover (2), the shield (6) and the heat insulation felt (1) in the electrode channel. The horizontal protective wall (42) is set horizontally in the electrode channel and is flush with the bottom of the heat insulation felt (1). The horizontal protective wall (42) has an electrode hole for the electrode to pass through.

3. The furnace bottom insulation device for the Czochralski single crystal furnace according to claim 2, characterized in that: The extension tube (7) is located at the splice of the baffle body, and the upper surface of the extension tube (7) is flush with the surface of the baffle body.

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