阅读说明：本技术 一种铸锭加热器及铸锭炉 (Ingot casting heater and ingot casting furnace ) 是由 张涛 陈旭光 肖贵云 白枭龙 陈骏 金浩 于 2019-10-17 设计创作，主要内容包括：本申请公开了一种铸锭加热器,包括侧部加热器及顶部加热器；所述侧部加热器设置在所述铸锭加热器的热场的四边,在所述热场内部的四个拐角处无连接,通过电极引出所述热场之外后互相电连接；所述顶部加热器设置在所述铸锭加热器的热场的顶部。本申请中在侧面设置了四个在热场内部互不接触的加热器,取消了热场内拐角处的连接器,避免了由于拐角处厚度难以控制带来的热场不均匀的风险,可以解决目前热场中存在的某个角过热,导致硅锭表面鼓包开裂、杂质位错多等质量问题；同时侧部加热器在热场内拐角处无连接,解决了拐角处对坩埚尺寸的限制,高质量晶体所占比例更多,提高生产效率。本申请还提供了一种具有上述有益效果的铸锭炉。(The application discloses an ingot casting heater, which comprises a side heater and a top heater; the side heaters are arranged on four sides of a thermal field of the ingot casting heater, are not connected at four corners in the thermal field, and are electrically connected with each other after being led out of the thermal field through electrodes; the top heater is arranged on the top of the thermal field of the ingot heater. In the application, the four heaters which are not in contact with each other in the thermal field are arranged on the side surface, the connector at the corner in the thermal field is cancelled, the risk of uneven thermal field caused by difficulty in controlling the thickness at the corner is avoided, and the quality problems of bulging cracking on the surface of a silicon ingot, more impurity dislocation and the like caused by overheating at a certain corner in the existing thermal field can be solved; meanwhile, the side heater is not connected at the corner in the thermal field, so that the limitation of the corner on the size of the crucible is solved, the proportion of high-quality crystals is more, and the production efficiency is improved. The application also provides an ingot furnace with the beneficial effects.)

1. An ingot casting heater is characterized by comprising a side heater and a top heater;

the side heaters are arranged on four sides of a thermal field of the ingot casting heater, are not connected at four corners in the thermal field, and are electrically connected with each other after being led out of the thermal field through electrodes;

The top heater is arranged on the top of the thermal field of the ingot heater.

2. The ingot heater of claim 1, wherein the electrodes of the side heater comprise a lead-out electrode and a merge electrode;

Wherein the lead-out electrode inside the thermal field is a graphite electrode or a C/C electrode; the current electrode outside the thermal field is at least one of a graphite electrode, a C/C electrode, a copper foil or a water-cooled copper electrode.

3. The ingot heater of claim 1, wherein the side heater is divided into a side upper heater and a side lower heater along a height of the ingot heater.

4. the ingot heater of claim 3, wherein the side upper heater and the side lower heater are electrically connected to each other after being led out of the thermal field by a lead-out electrode.

5. The ingot heater of claim 1, wherein the top heater is a serpentine top heater or a disc top heater.

6. the ingot heater of claim 5, wherein the disc-shaped top heater is configured to generate heat with a decreasing power from the center to the periphery.

7. The ingot heater of claim 1, wherein the side heater is a graphite heater or a C/C composite heater.

8. The ingot heater of claim 1, wherein the side heater is in the form of a curved elongated plate or a linear elongated plate.

9. An ingot furnace, characterized in that the ingot furnace comprises the ingot furnace heater of any one of claims 1 to 8.

Technical Field

the application relates to the field of crystal silicon ingots, in particular to an ingot heater and an ingot furnace.

background

Crystalline silicon is the basis of today's silicon semiconductor technology and solar power generation technology. The existing crystal silicon ingot casting technology can be summarized as that firstly, a crucible filled with high-purity silicon materials is put into a polycrystalline ingot casting furnace, and the crucible is electrified and heated by a heater to melt the silicon materials into silicon melt. And then, the bottom temperature of the silicon melt is reduced by taking measures of descending the crucible away from the hot zone, lifting the side heat insulation cage to leave a gap or enhancing the heat dissipation at the bottom and the like, so that the bottommost silicon melt forms a certain supercooling part and forms a temperature difference in the silicon melt, and then crystal nucleation and growth are started, and finally a silicon ingot is grown.

At present, heaters of a polycrystal ingot furnace are generally distributed around a crucible, five surfaces of the top and the side of the crucible are heated, the side heaters at least comprise four heating plates, the heating plates are distributed on four sides of a thermal field, corner parts in the thermal field are connected by using corner connecting plates, and the connecting plates can also play a role of heating resistors after being electrified. However, in actual operation, due to the fact that errors are prone to exist in the design, processing and installation processes, and due to the fact that the difference between the thicknesses and connection modes of the corner connecting plate and the edge heater, the distributed resistance between electrodes is prone to being inconsistent, heating temperatures of four sides of the heater during operation are inconsistent, the temperature in a thermal field is uneven, the phenomenon that the temperature of one side or one corner is overheated exists, melt convection is abnormal, a crystal growth interface is bent, impurity segregation is inconsistent, and the consistency of seed crystal retention height is affected when the seed crystal is adopted to prepare polycrystal or similar single crystal. In the specific production, the problems of bulging and cracking of a silicon ingot, uneven resistivity, poor crystal quality, low percent of pass and the like can be caused. In addition, the corner connecting plates of the side heaters also limit the diagonal size of the crucible and the silicon ingot, thereby limiting further increase in the size of the crucible and the silicon ingot. Therefore, how to design the heater so that the thermal field is more uniform and solve the problem of limited space of the heater is a problem to be solved by those skilled in the art.

Content of application

The application aims at providing an ingot casting heater and an ingot casting furnace to solve the problems of uneven thermal field and limited space in the prior art.

In order to solve the technical problem, the application provides an ingot casting heater, which comprises a side heater and a top heater;

The side heaters are arranged on four sides of a thermal field of the ingot casting heater, are not connected at four corners in the thermal field, and are electrically connected with each other after being led out of the thermal field through electrodes;

The top heater is arranged at the top of the thermal field of the ingot casting heater.

Optionally, in the ingot heater, the electrodes of the side heater include a lead-out electrode and a confluence electrode;

wherein the lead-out electrode inside the thermal field is a graphite electrode or a C/C electrode; the current electrode outside the thermal field is at least one of a graphite electrode, a C/C electrode, a copper foil or a water-cooled copper electrode.

Alternatively, in the ingot heater, the side heater may be divided into a side upper heater and a side lower heater in a height direction of the ingot heater.

Alternatively, in the ingot heater, the side upper heater and the side lower heater are electrically connected to each other after being led out of the thermal field through a lead-out electrode.

optionally, in the ingot heater, the top heater is a serpentine top heater or a disc top heater.

Optionally, in the ingot heater, the heat generation power of the disc-shaped top heater is gradually reduced from the center to the periphery.

optionally, in the ingot heater, the side heater is a graphite heater or a C/C composite heater.

Alternatively, in the ingot heater, the side heater may have a curved elongated plate shape or a straight elongated plate shape.

The application also provides an ingot furnace, the ingot furnace includes any kind of ingot heater of above-mentioned.

The ingot casting heater provided by the application comprises a side heater and a top heater; the side heaters are arranged on four sides of a thermal field of the ingot casting heater, are not connected at four corners in the thermal field, and are led out of the thermal field through electrodes and then are connected with each other; the top heater is arranged on the top of the thermal field of the ingot heater. In the application, four heaters which are not in contact with each other in a thermal field are arranged on the side surface, connecting plates at corners are omitted, the connection of the heaters at the side parts is connected from the inside of the thermal field to the outside of the thermal field, the risk of uneven thermal field caused by the connection of heating plates at the corners is avoided, the quality problems of bulging cracking on the surface of a silicon ingot, more impurity dislocation and the like caused by overheating of a certain edge or a certain corner in the existing thermal field can be solved, and the consistency of seed crystal retention height can be kept when the seed crystal is adopted to prepare polycrystal or single-like crystal; in addition, the corner connecting plate at the corner in the thermal field is eliminated, the available space in the thermal field is increased, a larger crucible can be used for filling more silicon materials, and a silicon ingot with larger size is produced, so that the temperature distribution of each point in the space is more uniform, the proportion of high-quality crystals in the middle part is more, the product quality is improved, and the production cost is reduced. The application also provides an ingot furnace with the beneficial effects.

Drawings

For a clearer explanation of the embodiments or technical solutions of the prior art of the present application, the drawings needed for the description of the embodiments or prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic top view of one embodiment of an ingot heater provided herein;

FIG. 2 is a schematic front view of one embodiment of an ingot heater provided herein;

FIG. 3 is a schematic top view of another embodiment of an ingot heater provided herein;

FIG. 4 is a schematic front view of another embodiment of an ingot heater provided herein;

FIG. 5 is a schematic top view of yet another embodiment of an ingot heater provided herein;

FIG. 6 is a schematic elevation view of yet another embodiment of an ingot heater provided herein;

FIG. 7 is a schematic top view of yet another embodiment of an ingot heater provided herein;

Fig. 8 is a schematic front view of a still further embodiment of the ingot heater provided by the present application.

Detailed Description

In order that those skilled in the art will better understand the disclosure, the following detailed description will be given with reference to the accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

the core of the present application is to provide an ingot heater, one embodiment of which is schematically shown in fig. 1 in a top view and fig. 2 in a side view, and is referred to as a first embodiment, and comprises a side heater 200 and a top heater 100;

The side heaters 200 are arranged at four sides of a thermal field of the ingot casting heater, are not connected at four corners in the thermal field, and are electrically connected with each other after being led out of the thermal field through electrodes;

The top heater 100 is disposed on top of the thermal field of the ingot heater.

further, the electrodes of the side heater 200 include a lead-out electrode and a confluent electrode;

Wherein the lead-out electrode inside the thermal field is a graphite electrode or a C/C electrode; the current electrode outside the thermal field is at least one of a graphite electrode, a C/C electrode, a copper foil or a water-cooled copper electrode. The graphite or C/C composite material has good conductivity, controllable resistance change along with temperature change, good high temperature resistance, low cost and easy obtainment, and can resist high temperature in the process of casting crystal silicon ingots. In particular, the electrode material connecting the side heater 200 at the outer corners of the thermal field is preferably copper. The copper has good conductivity and is suitable for being used in the environment with lower temperature.

the thermal field inside and the thermal field outside described in the present application refer to the thermal field inside and the thermal field outside that use a thermal insulation material as a boundary.

It should be noted that the connection mode of the electrode for leading the side heater out of the thermal field at the outer corner of the thermal field may be a method of connecting two electrodes and then connecting the two electrodes to an external power supply electrode, or an equivalent connection method of connecting the two electrodes to the external power supply electrode respectively.

The ingot heater provided by the application comprises a side heater 200 and a top heater 100; the side heaters 200 are arranged at four sides of a thermal field of the ingot heater, and no connection is formed at four corners in the thermal field; the top heater 100 is disposed on top of the thermal field of the ingot heater. In the application, the four heaters which are not in contact with each other in the thermal field are arranged on the side surface, and the connector at the corner is cancelled, so that the risk of nonuniformity of the thermal field caused by the connecting plates at the corner is avoided, the quality problems of bulging and cracking on the surface of the silicon ingot, more impurity dislocation and the like caused by overheating of a certain edge or a certain corner in the existing thermal field can be solved, the integrity and the quality of the obtained silicon ingot are improved, and the consistency of the seed crystal retention height can be kept when the seed crystal is adopted to prepare polycrystal or single-like crystal; in addition, after the limitation of the connecting plates at the corners to the space is cancelled, the available space in the heat field can be increased, a larger crucible is used for filling more silicon materials, and a silicon ingot with larger size is produced, so that the temperature distribution of each point in the space is more uniform, the proportion of high-quality crystals in the middle is more, the product quality is improved, and the production cost is reduced.

On the basis of the first embodiment, the side heater 200 is further limited to obtain a second embodiment, which is shown in fig. 3 in a schematic top view structure and fig. 4 in a side view structure, and includes the side heater 200 and the top heater 100;

the side heaters 200 are arranged at four sides of a thermal field of the ingot casting heater, are not connected at four corners in the thermal field, and are electrically connected with each other after being led out of the thermal field through electrodes;

The top heater 100 is arranged on top of the thermal field of the ingot heater;

the side heater 200 is divided into a side upper heater 201 and a side lower heater 202 in the height direction of the ingot heater.

the difference between the present embodiment and the above embodiments is that the present embodiment further divides the side heater 200 into two parts, and the rest of the structure is the same as that of the above embodiments, and therefore, the detailed description thereof is omitted.

Further, the side upper heater 201 and the side lower heater 202 are electrically connected to each other after being extracted from the thermal field by lead-out electrodes. The technical feature means that the lead-out electrodes are respectively connected with the side upper heater 201 and the side lower heater 202, extend out of the thermal field, and then are combined into one electrode, so that the side upper heater 201 and the side lower heater 202 which are positioned at the same side are electrically connected.

in the present embodiment, the side heater 200 is divided into the side upper heater 201 and the side lower heater 202 along the height direction of the ingot heater, and since the polysilicon grows upward from the bottom with lower temperature in the crystal growth process, that is, in the process of silicon ingot growth, a temperature gradient is required, while the side heater in the prior art is a whole, it is difficult to design different powers in the crystal growth direction according to different temperature requirements, and is not beneficial to polysilicon growth; in reverse view of the side heater 200 of the present application, the heating power of the side upper heater 201 can be made larger than that of the side lower heater 202 by dividing into two parts, so that a controllable temperature gradient is formed. Compared with the prior art, the controllability of the temperature gradient is enhanced, the problems that the cooling capacity is reduced, the crystal growth speed is slowed down, and the dislocation multiplication speed is increased due to the reasons of lateral heating, latent heat release of crystal growth and the like in the later crystal growth period are avoided, the energy waste is avoided, and the cost is reduced.

On the basis of the first embodiment, the top heater 100 is further limited to obtain a third embodiment, and fig. 5 and 6 are top and front views of the third embodiment, including the side heater 200 and the top heater 100;

The side heaters 200 are arranged at four sides of a thermal field of the ingot casting heater, are not connected at four corners in the thermal field, and are electrically connected with each other after being led out of the thermal field through electrodes;

The top heater 100 is arranged on top of the thermal field of the ingot heater; the top heater 100 is a disc-shaped top heater 100 which is easy to process and has good installation symmetry, so that the unevenness of a thermal field caused by non-design factors is avoided, and the quality of the prepared silicon ingot is further improved.

Specifically, the top heaters 100 are distributed in a disc spoke shape; the top heater 100 may also be distributed in concentric circles with an increasing distance, and the heating power thereof is gradually reduced from the center to the periphery.

In the present embodiment, it is defined that the center heating power of the top heater 100 is greater than the edge heating power. In the prior art, the heating power of each part of the top heater 100 is the same, and the growth of polysilicon is generally completed at the center of the top heater, and then the high-temperature silicon melt at the four corners is gradually solidified to complete corner crystal growth. The corner crystal growth has long time consumption, high energy consumption and poor crystal quality, therefore, the edge heating power of the top heater 100 is reduced in the application, the corner temperature is slightly lower than the central temperature, the growth of the corner crystal can be promoted, and the silicon ingot with a smooth growth interface is obtained, namely, the top heater 100 in the application can pertinently change the heating power of the center and the periphery of the top, change the shape of the solid-liquid growth interface of the middle and later periods of the long crystal, improve the quality of the upper crystal in the silicon ingot, and reduce the corner crystal growth and the whole operation time.

On the basis of the first embodiment, the side heater 100 is further limited to obtain a fourth embodiment, which is shown in fig. 7 in a schematic top view structure and fig. 8 in a side view structure, and includes a side heater 200 and a top heater 100;

the side heaters 100 are arranged at four sides of a thermal field of the ingot casting heater, are not connected at four corners in the thermal field, and are electrically connected with each other after being led out of the thermal field through electrodes;

the side heater is made of C/C materials and adopts a linear long plate-shaped design.

The difference between the present embodiment and the first embodiment is that the present embodiment defines that the material of the side heater 100 is C/C, and the shape of the side heater is a straight long plate, and the rest of the structure is the same as the above embodiments, and will not be described herein again.

In the present embodiment, a C/C material is used. Because the C/C material has higher resistance, better strength and larger toughness than graphite, a plurality of thin linear long plate-shaped C/C heaters can be connected in parallel to be used as side heaters. As the thickness of the heater is reduced, the space for placing the crucible in the thermal field is enlarged, the advantage of the space without connection of the side heater at the corner in the thermal field can be exerted to the greatest extent, and the crucible with larger size can be used for casting silicon ingots with larger size and higher weight, so that the overall quality of the silicon ingots is improved, the production efficiency is improved, and the cost is reduced. In addition, the linear heater is easier to machine and form, and is easier to operate in terms of installation and maintenance, which can lead to cost reduction.

the application also provides an ingot furnace, the ingot furnace includes any kind of ingot heater of above-mentioned. The ingot furnace comprises the ingot heater, wherein the ingot heater comprises a side heater 200 and a top heater 100; the side heaters 200 are arranged at four sides of a thermal field of the ingot heater, are not connected at four corners inside the thermal field, and are connected after being led out from the thermal field through electrodes. The top heater 100 is disposed on top of the thermal field of the ingot heater. In the application, the four heaters which are not in contact with each other in the thermal field are arranged on the side surface, and the connecting plates at the corners are cancelled, so that the risk of nonuniformity of the thermal field caused by the connecting plates at the corners is avoided, the quality problems of bulging cracking on the surface of the silicon ingot, more impurity dislocation and the like caused by overheating of a certain edge or a certain corner in the existing thermal field can be solved, and the integrity and the quality of the obtained silicon ingot are improved; in addition, the limitation of a connector at a corner to the space is cancelled, the available space in a thermal field is increased, a larger crucible can be used for filling more silicon materials, and a silicon ingot with larger size is produced, so that the temperature distribution of each point in the space is more uniform, the proportion of high-quality crystals in the middle part is more, the product quality is improved, and the production cost is reduced.

The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

It is to be noted that, in the present specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

the ingot heater and the ingot furnace provided by the application are described in detail above. The principles and embodiments of the present application are explained herein using specific examples, which are provided only to help understand the method and the core idea of the present application. It should be noted that, for those skilled in the art, it is possible to make several improvements and modifications to the present application without departing from the principle of the present application, and such improvements and modifications also fall within the scope of the claims of the present application.