Method and apparatus for crushing electronic grade polysilicon

Abstract

The present application relates to the technical field of polycrystalline silicon crushing, and particularly relates to a method and device for crushing electronic-grade polycrystalline silicon, which comprises the following steps: obtaining a whole original electronic-grade polycrystalline silicon rod, and placing the whole original electronic-grade polycrystalline silicon rod which is not cut off in a heating area; determining heating conditions including a heating temperature and a power-on parameter according to a rod body parameter of the whole original electronic-grade polycrystalline silicon rod, a target crushing particle size and a cooling medium temperature; passing a current to the whole original electronic-grade polycrystalline silicon rod through an electrode which is electrically connected to the whole original electronic-grade polycrystalline silicon rod according to the power-on parameter, so that the whole original electronic-grade polycrystalline silicon rod is heated to the heating temperature; and transferring the whole original electronic-grade polycrystalline silicon rod after being heated to a cooling medium for quenching, so that the whole original electronic-grade polycrystalline silicon rod generates thermal shock cracks and is crushed. The present application can improve the yield of the target particle size product in the process of crushing electronic-grade polycrystalline silicon.

Description

Technical Field

[0001] This invention relates to the field of polycrystalline silicon crushing technology, and in particular to a method and equipment for crushing electronic-grade polycrystalline silicon. Background Technology

[0002] Electronic-grade polysilicon is typically produced through vapor deposition, resulting in large, rod-shaped materials. To meet the requirements of downstream processes such as cleaning, packaging, and feeding, the polysilicon rods need to be crushed into block-shaped silicon materials within a specific particle size range. Currently, polysilicon crushing methods mainly include manual crushing, mechanical crushing, and thermal crushing. Manual crushing is labor-intensive, while mechanical crushing can utilize equipment such as jaw crushers, roller crushers, and cone crushers. Thermal crushing typically utilizes the thermal stress generated when polysilicon is heated and then cooled to induce cracking.

[0003] Polycrystalline silicon is an intrinsically brittle material, and its fragmented particle size is related to factors such as the material's fracture strength, grain state, rod size, heating temperature, and cooling medium temperature. In actual production, electronic-grade polycrystalline silicon has high requirements for impurity control and particle size distribution. Excessively fine powder will cause losses, while excessively large pieces require further processing. Although existing crushing processes can crush polycrystalline silicon rods, the particle size distribution after crushing is still prone to fluctuation under different rod specifications and target particle size requirements, resulting in room for improvement in the yield of silicon material of the target particle size and the utilization rate of silicon rods.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the general background of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] This invention provides a method and equipment for crushing electronic-grade polycrystalline silicon, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for crushing electronic-grade polycrystalline silicon includes the following steps: Obtain the entire native electronic-grade polycrystalline silicon rod, and place the uncut entire native electronic-grade polycrystalline silicon rod in the heating area; Heating conditions are determined based on the rod body parameters, target crushing particle size, and cooling medium temperature of the entire native electronic-grade polycrystalline silicon rod. The heating conditions include the heating temperature and the electrical parameters used to bring the entire native electronic-grade polycrystalline silicon rod to the heating temperature. According to the energizing parameters, current is passed through the electrode electrically connected to the entire native electronic-grade polycrystalline silicon rod to heat the entire native electronic-grade polycrystalline silicon rod to the heating temperature. The heated whole native electronic-grade polycrystalline silicon rod is transferred to a cooling medium for rapid cooling, causing the whole native electronic-grade polycrystalline silicon rod to develop thermal shock cracks and break.

[0007] Furthermore, the entire native electronic-grade polycrystalline silicon rod retains conductive connection portions for growing the entire native electronic-grade polycrystalline silicon rod; According to the stated energizing parameters, current is supplied to the entire native electronic-grade polycrystalline silicon rod through electrodes electrically connected to it, including: Make the electrode contact the conductive connection portion; Current is supplied to the entire native electronic-grade polycrystalline silicon rod through the electrodes and the conductive connection.

[0008] Furthermore, the rod parameters include material parameters and dimensional parameters; Based on the rod parameters, target particle size, and cooling medium temperature of the entire native electronic-grade polycrystalline silicon rod, the heating conditions are determined, including the following steps: The critical thermal shock temperature difference required for the entire native electronic-grade polycrystalline silicon rod to generate thermal shock cracks is determined based on the material parameters. The target thermal shock temperature difference is determined based on the target crushing particle size and the critical thermal shock temperature difference. The heating temperature is determined based on the target thermal shock temperature difference and the temperature of the cooling medium. The energizing parameters are determined based on the dimensional parameters and the heating temperature.

[0009] Furthermore, determining the energizing parameters based on the dimensional parameters and the heating temperature includes the following steps: The volume of the entire native electronic-grade polycrystalline silicon rod is determined based on the aforementioned size parameters; The heating temperature is determined based on the volume, density, and specific heat capacity of the entire native electronic-grade polycrystalline silicon rod, as well as the heating temperature and the cooling medium temperature. The power parameters are determined based on the heating temperature.

[0010] Furthermore, the heated whole native electronic-grade polycrystalline silicon rod is transferred to a cooling medium for rapid cooling, including the following steps: Remove the support structure from the entire native electronic-grade polycrystalline silicon rod; The heated whole native electronic-grade polycrystalline silicon rod is then dropped into the cooling medium located below the heating area.

[0011] Furthermore, when the heated whole native electronic-grade polycrystalline silicon rod is transferred to a cooling medium for rapid cooling, the graphite base of the whole native electronic-grade polycrystalline silicon rod is separated from the rest of the whole native electronic-grade polycrystalline silicon rod by a partition provided in the cooling medium. After the entire native electronic-grade polycrystalline silicon rod is rapidly cooled, a mechanical force is applied to the entire native electronic-grade polycrystalline silicon rod with the thermal shock crack, causing the entire native electronic-grade polycrystalline silicon rod to further break along the thermal shock crack.

[0012] An electronic-grade polysilicon crushing device, applicable to the aforementioned electronic-grade polysilicon crushing method, comprising: Heating unit for holding an uncut whole native electronic-grade polycrystalline silicon rod; An electrode unit is used to be electrically connected to the entire native electronic-grade polycrystalline silicon rod and to pass current through the entire native electronic-grade polycrystalline silicon rod so that the entire native electronic-grade polycrystalline silicon rod is heated. Cooling unit, used to contain cooling medium; A transfer unit is used to transfer the heated whole native electronic-grade polycrystalline silicon rod from the heating unit to the cooling medium in the cooling unit, so that the whole native electronic-grade polycrystalline silicon rod will generate thermal shock cracks and break. A control unit, connected to the electrode unit, is used to determine heating conditions based on the rod body parameters, target crushing particle size, and cooling medium temperature of the entire native electronic-grade polycrystalline silicon rod, and to control the current output of the electrode unit according to the heating conditions. The heating conditions include heating temperature and energizing parameters for bringing the entire native electronic-grade polycrystalline silicon rod to the heating temperature.

[0013] Furthermore, the heating unit is disposed above the cooling unit, and the electrode unit is disposed on the heating unit; The transfer unit includes a movable support structure for supporting the entire native electronic-grade polycrystalline silicon rod and for allowing the heated native electronic-grade polycrystalline silicon rod to fall into the cooling medium when opened.

[0014] Furthermore, the electrode unit includes an adjustable electrode, which is disposed on the heating unit and is movable relative to the entire native electronic-grade polycrystalline silicon rod to connect with the conductive connection portion of the entire native electronic-grade polycrystalline silicon rod. The cooling unit is provided with a partition, which is used to separate the graphite base of the entire native electronic-grade polycrystalline silicon rod from the rest of the rod when the rod enters the cooling medium.

[0015] The technical solution of this invention can achieve the following technical effects: This invention determines the heating conditions based on the rod parameters, target particle size, and cooling medium temperature of the entire native electronic-grade polycrystalline silicon rod. The polycrystalline silicon rod is then heated by electricity according to these conditions, followed by rapid cooling and crushing. This establishes a correspondence between the heating process and the silicon rod specifications, target particle size requirements, and cooling conditions. Compared to methods relying solely on fixed empirical temperatures for thermal crushing, this invention improves the controllability of particle size distribution after crushing silicon rods of different specifications.

[0016] By passing current through electrodes to the entire native electronic-grade polycrystalline silicon rod, the polycrystalline silicon rod is heated by the current heating effect. The polycrystalline silicon rod itself participates in the heating, which can reduce the impact of insufficient heat transfer efficiency in external heating methods. This helps the silicon rod reach the set heating temperature and forms stable thermal shock conditions for subsequent rapid cooling.

[0017] Using whole, uncut, native electronic-grade polycrystalline silicon rods as the processing target reduces the disturbance to the native stress state inside the silicon rod caused by pre-cutting, hammering, and other treatments. This allows thermal shock cracks generated during rapid cooling to propagate within a relatively intact rod structure, which is beneficial for improving silicon rod utilization and silicon yield of the target particle size. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a process for crushing electronic-grade polycrystalline silicon. Figure 2 A schematic diagram of an electronic-grade polysilicon crushing device; Figure 3 This is a top view of the heating unit; Figure 4 Side view of the heating and cooling units; Figure 5 This is a schematic diagram of the load-bearing structure; Figure 6 This is a schematic diagram of the structure of the adjustable electrode and the graphite base. Figure 7 A graph showing the relationship between yield and thermal shock temperature difference in a process validation example; Figure 8 This is a current-temperature curve of the silicon rod in a process verification example.

[0020] Reference numerals: 1. Heating unit; 2. Electrode unit; 21. Adjustable electrode; 3. Cooling unit; 31. Partition; 4. Transfer unit; 41. Supporting structure; 5. Whole native electronic-grade polycrystalline silicon rod; 51. Graphite base. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] Example 1: like Figure 1 As shown, this application provides a method for crushing electronic-grade polycrystalline silicon, including the following steps: Obtain the entire native electronic-grade polycrystalline silicon rod and place the uncut native electronic-grade polycrystalline silicon rod in the heating area.

[0024] The whole native electronic-grade polycrystalline silicon rod can be a polycrystalline silicon rod produced by vapor deposition that has not yet undergone hammering, cutting, or segmented crushing. This polycrystalline silicon rod can be a U-shaped rod or other rod-shaped polycrystalline silicon material whose original overall structure has not been damaged. Compared to cutting the polycrystalline silicon rod into segments before thermal crushing, the whole native electronic-grade polycrystalline silicon rod has not undergone mechanical impact or cutting before entering the heating zone. The original stress state and grain structure inside the rod are less disturbed by external factors, facilitating more complete crack propagation through subsequent thermal shock.

[0025] In practice, the hatch above the heating area can be opened, and the entire virgin electronic-grade polycrystalline silicon rod can be placed into the heating area using a robotic arm, hoisting mechanism, or other clean transport mechanism. During transport, it is preferable to avoid direct contact between metal parts and the polycrystalline silicon rod body to reduce the introduction of metal impurities.

[0026] Furthermore, the heating conditions are determined based on the rod parameters of the entire native electronic-grade polycrystalline silicon rod, the target crushed particle size, and the temperature of the cooling medium; the heating conditions include the heating temperature and the electrical parameters used to bring the entire native electronic-grade polycrystalline silicon rod to the heating temperature.

[0027] The rod parameters can include the material and dimensional parameters of the entire native electronic-grade polycrystalline silicon rod. Material parameters can include one or more of the following: fracture stress, Poisson's ratio, elastic modulus, coefficient of thermal expansion, specific heat capacity, and density. Dimensional parameters can include one or more of the following: diameter, length, cross-sectional area, volume, and mass. The target crushing particle size can be determined based on downstream product requirements; for example, a particle size range of 10mm to 50mm can be used as the primary target particle size range, or a particle size range of 10mm to 100mm can be used as the acceptable product particle size range.

[0028] The cooling medium temperature refers to the temperature at which the cooling medium creates a thermal shock temperature difference when the heated, virgin electronic-grade polycrystalline silicon rod enters the cooling medium. The cooling medium can be water, or any other liquid medium that meets the cleanliness requirements of electronic-grade polycrystalline silicon and provides rapid cooling. Using water as the cooling medium results in lower process costs and a higher cooling rate, making it suitable for quickly establishing a temperature gradient between the surface and interior of the polycrystalline silicon rod.

[0029] According to the power-on parameters, current is passed through the electrodes that are electrically connected to the entire native electronic-grade polycrystalline silicon rod to heat the entire native electronic-grade polycrystalline silicon rod to the heating temperature.

[0030] This embodiment uses the current heating effect to heat the entire native electronic-grade polycrystalline silicon rod. When the current passes through the polycrystalline silicon rod, the polycrystalline silicon rod itself acts as a heat source, generating heat. Compared with external radiation heating, the heat transfer path is more direct, which helps to shorten the heating time and reduce energy consumption caused by insufficient heat transfer efficiency between the external heating device and the silicon rod.

[0031] The energizing parameters can include one or more of the following: current value, voltage value, energizing time, heating rate, power curve, or current control curve. In actual production, the energizing parameters can be set according to the target heating temperature, silicon rod size, equipment power, and heat loss. To reduce thermal shock to the equipment and ensure uniform heating of the silicon rod, the heating rate can be controlled to not exceed 20℃ / min. After the silicon rod reaches the heating temperature, it can be held at that temperature within the heating zone for a preset time, such as 5 minutes, to allow the surface and internal temperature of the silicon rod to become more uniform.

[0032] The heated virgin electronic-grade polycrystalline silicon rod is transferred to a cooling medium for rapid cooling, causing thermal shock cracks and breakage in the virgin electronic-grade polycrystalline silicon rod.

[0033] During rapid cooling, the surface temperature of the silicon rod drops rapidly, while the internal temperature decreases relatively slowly, creating a temperature difference between the surface and interior of the rod, and between different grains. This temperature difference generates tensile or shear stress at the grain boundaries. When the thermal stress reaches or exceeds the thermal shock resistance critical state of the polycrystalline silicon material, thermal shock cracks occur in the silicon rod. Because this embodiment uses a whole, native electronic-grade polycrystalline silicon rod for heating and rapid cooling, and the rod was not artificially broken into segments before rapid cooling, the thermal shock effect can propagate within a more intact rod structure, which is beneficial for increasing the proportion of the target particle size product after crushing.

[0034] This embodiment reduces the mechanical damage to the silicon rod body caused by processes such as removing the carbon head, removing the crossbeam, and pre-segmented crushing by "heating the entire native electronic-grade polycrystalline silicon rod as a whole and then rapidly cooling and thermally shocking it to break it up". This not only improves the utilization rate of the silicon rod, but also makes the thermal shock crack propagation process closer to the stress release process under the native structure of the whole rod.

[0035] Example 2: Based on Example 1, the entire native electronic-grade polycrystalline silicon rod retains conductive connection parts for growing the entire native electronic-grade polycrystalline silicon rod.

[0036] According to the energizing parameters, current is supplied to the entire native electronic-grade polycrystalline silicon rod through an electrode electrically connected to the entire rod, including: making the electrode contact with the conductive connection part; and supplying current to the entire native electronic-grade polycrystalline silicon rod through the electrode and the conductive connection part.

[0037] The conductive connection can be a graphite base formed or retained during the growth of the polycrystalline silicon rod. The entire native electronic-grade polycrystalline silicon rod typically has a relatively stable conductive connection with the graphite base; therefore, the graphite base can be used as a transitional conductive structure between the electrode and the polycrystalline silicon rod. This eliminates the need to separately process conductive clamping surfaces on the polycrystalline silicon rod body, reducing mechanical damage to the polycrystalline silicon rod body.

[0038] like Figure 6 As shown, the electrode can be inserted, socketed, or pressed into the graphite base. After the electrode contacts the conductive connection, current flows through the conductive connection into the polycrystalline silicon rod body, causing the polycrystalline silicon rod to heat up through its own resistance. The electrode position can be adjusted in the vertical and horizontal directions to accommodate polycrystalline silicon rods of different sizes or placement positions, ensuring stable contact between the electrode and the conductive connection.

[0039] Using conductive connectors for heating can also reduce the risk of edge chipping, local contamination, or unstable contact caused by electrodes directly clamping the polycrystalline silicon rod body.

[0040] Example 3: Based on Example 1, the rod parameters include material parameters and dimensional parameters.

[0041] Based on the rod parameters of the entire native electronic-grade polycrystalline silicon rod, the target crushing particle size, and the temperature of the cooling medium, the heating conditions are determined, including the following steps: The critical thermal shock temperature difference required for thermal shock cracking of the entire native electronic-grade polycrystalline silicon rod is determined based on material parameters; the target thermal shock temperature difference is determined based on the target crushing particle size and the critical thermal shock temperature difference; the heating temperature is determined based on the target thermal shock temperature difference and the cooling medium temperature; and the energizing parameters are determined based on dimensional parameters and heating temperature.

[0042] The critical thermal shock temperature difference can be understood as the temperature difference condition that can induce a sudden drop in the strength of a polycrystalline silicon rod and cause cracks when the rod is transferred from a heated state to a cooling medium. The critical thermal shock temperature difference is related to the fracture stress, Poisson's ratio, elastic modulus, and coefficient of thermal expansion of the polycrystalline silicon material itself.

[0043] In one specific implementation, the critical thermal shock temperature difference can be characterized by the thermal shock fracture parameter R, which can be determined according to the following relationship: ; Where R is the thermal shock fracture parameter, σ is the fracture stress, v is Poisson's ratio, E is the elastic modulus, and α is the coefficient of thermal expansion.

[0044] The coefficient of thermal expansion of polycrystalline silicon can be taken as... The fracture stress can be taken as 100 MPa to 200 MPa, Poisson's ratio as 0.22 to 0.26, elastic modulus as 150 GPa to 180 GPa, and specific heat capacity as 700 J / (kg·K). When the fracture stress is taken as 100 MPa, Poisson's ratio as 0.26, and elastic modulus as 180 GPa, the calculated thermal shock resistance fracture parameter is approximately 146.82℃. When the fracture stress is taken as 200 MPa, Poisson's ratio as 0.22, and elastic modulus as 150 GPa, the calculated thermal shock resistance fracture parameter is approximately 371.24℃.

[0045] This allows us to first determine the temperature range within which thermal shock fracture occurs, and then select the target thermal shock temperature difference based on the target particle size. If the goal is to increase the proportion of products with a particle size of 10mm to 50mm, a higher target thermal shock temperature difference can be selected based on experimental verification; if the goal is to reduce the proportion of excessively fine powder, the target thermal shock temperature difference can be appropriately reduced.

[0046] The heating temperature is determined based on the target thermal shock temperature difference and the temperature of the cooling medium.

[0047] For example, when the cooling medium temperature is 45℃ and the target thermal shock temperature difference is close to 400℃, the heating temperature can be set in the range of approximately 400℃ to 500℃. Experimental data from the technical disclosure shows that when the cooling medium temperature is 45℃, the yield of qualified particle sizes (10mm to 100mm) is relatively high when the heating temperature is around 400℃. As the heating temperature continues to increase, the proportion of particle sizes (10mm to 50mm) increases, but the proportion of fine powder (0mm to 10mm) may also increase. Therefore, the heating temperature can be selected based on the target product particle size range.

[0048] The power parameters are determined based on the size parameters and heating temperature.

[0049] Dimensional parameters may include the diameter, length, cross-sectional area, volume, or mass of the entire native electronic-grade polycrystalline silicon rod. For silicon rods with larger diameters or longer lengths, the energizing time can be appropriately extended, the target current increased, or the heating curve adjusted at the same target heating temperature; for silicon rods with smaller diameters or shorter lengths, the target current can be reduced or the energizing time shortened to avoid localized overheating.

[0050] In this way, the heating temperature is mainly determined by the target thermal shock temperature difference and the temperature of the cooling medium, while the power parameters are matched according to the silicon rod size and the heating temperature, so that whole native electronic-grade polycrystalline silicon rods of different specifications can reach a temperature state suitable for thermal shock breakage.

[0051] Example 4: Based on Example 3, the energizing parameters are determined according to the dimensional parameters and heating temperature, including the following steps: The equivalent heated dimensions of the entire native electronic-grade polycrystalline silicon rod are determined based on the size parameters; Based on the equivalent heated dimensions and heating temperature, determine the heating rate, target current, target voltage, and / or energizing time to heat the entire native electronic-grade polycrystalline silicon rod to the heating temperature. The energizing parameters are formed based on the heating rate, target current, target voltage, and / or energizing time.

[0052] The equivalent heated dimensions can be determined based on the diameter, length, cross-sectional area, volume, or mass of the entire native electronic-grade polycrystalline silicon ingot. Even if the target heating temperature is the same, the energizing process required to reach that temperature will differ for ingots of different specifications. Therefore, the energizing parameters can be adjusted based on the equivalent heated dimensions.

[0053] Specifically, when the diameter, length, or mass of the entire native electronic-grade polycrystalline silicon rod is large, the energizing time can be increased, the target current increased, or the output power increased to allow the entire native electronic-grade polycrystalline silicon rod to heat up to the heating temperature. When the diameter, length, or mass of the entire native electronic-grade polycrystalline silicon rod is small, the target current can be reduced, the energizing time shortened, or the output power reduced to avoid excessively rapid heating or localized overheating.

[0054] In one specific operation, the heating rate can be controlled to not exceed 20℃ / min. After the entire native electronic-grade polycrystalline silicon rod is heated to the heating temperature, it can be held in the heating zone for a preset time, such as 5 minutes, to make the surface temperature and internal temperature of the entire native electronic-grade polycrystalline silicon rod tend to be consistent. After the holding time is completed, the entire native electronic-grade polycrystalline silicon rod is then transferred to a cooling medium for rapid cooling.

[0055] By setting the parameters as described above, the energizing parameters can be matched with the specifications and heating temperature of the entire native electronic-grade polycrystalline silicon rod. For mass production processes, the heating temperature can be determined first based on the target crushed particle size and the temperature of the cooling medium. Then, the current control curve or energizing time can be set according to the silicon rod diameter, length, and equipment output capacity, thereby improving the consistency of the heating process and the stability of the crushed particle size distribution.

[0056] Example 5: Based on Example 1, the heated whole native electronic-grade polycrystalline silicon rod is transferred to a cooling medium for rapid cooling, including the following steps: Remove the support structure from the entire native electronic-grade polycrystalline silicon rod; allow the heated native electronic-grade polycrystalline silicon rod to fall into the cooling medium located below the heating area.

[0057] like Figure 2 and Figure 4 As shown, the heating area can be positioned above the cooling medium. After the entire native electronic-grade polycrystalline silicon rod is heated by electricity, the current can be cut off and the electrodes removed. Then, the support structure located at the bottom of the heating area can be moved, allowing the silicon rod to fall into the cooling medium by gravity.

[0058] By arranging the silicon rods vertically, the transfer time between the end of heating and the start of rapid cooling can be shortened, reducing the problem of a smaller thermal shock temperature difference caused by the silicon rods naturally cooling in the air. This allows for a more direct thermal shock condition between the heating temperature and the cooling medium temperature, improving process repeatability.

[0059] like Figure 5 As shown, the supporting structure can be a support member with a supporting slope. During the heating stage, the supporting structure supports the silicon rod, and during the rapid cooling stage, it moves away from the silicon rod, allowing the silicon rod to quickly enter the cooling medium. The contact area between the supporting structure and the silicon rod is preferably made of high-purity material or a high-purity material separator to reduce impurity contamination.

[0060] Example 6: Based on Example 1, when the heated whole native electronic-grade polycrystalline silicon rod is transferred to a cooling medium for rapid cooling, the graphite base of the whole native electronic-grade polycrystalline silicon rod is separated from the rest of the whole native electronic-grade polycrystalline silicon rod by a partition provided in the cooling medium.

[0061] After the entire native electronic-grade polycrystalline silicon rod is rapidly cooled, a mechanical force is applied to the entire native electronic-grade polycrystalline silicon rod with thermal shock cracks, causing the entire native electronic-grade polycrystalline silicon rod to further break along the thermal shock cracks.

[0062] like Figure 4 As shown, the partition can be positioned within the cooling medium near the electrode. When the heated, fully virgin electronic-grade polycrystalline silicon rod falls into the cooling medium, the graphite base is blocked or impacted in the opposite direction by the partition, separating from the silicon rod body and confining it to one side of the partition. This reduces the likelihood of the graphite base mixing into the qualified product area along with the silicon material, thus lowering the risk of graphite contamination.

[0063] The partition can be a partition plate, baffle, or a partition structure with a blocking function. The material of the partition can be selected according to the cooling medium environment and cleanliness requirements, such as using water-resistant, impact-resistant, and temperature-resistant materials, and a cleanliness isolation layer is set in the area in contact with polycrystalline silicon.

[0064] After rapid cooling, thermal shock cracks have formed inside the silicon rod. At this point, applying a small mechanical force to the silicon rod will cause it to further break along the cracks. This mechanical force can be a light tap, crushing, or vibration impact. Since the cracks have already formed, the mechanical force does not need to reach the strength required for traditional mechanical crushing, thus reducing the increase in fine powder caused by over-grinding. In the technical briefing, the experiment used approximately 10J of impact energy to assist in the crushing of the water-quenched silicon rod, while normal crushing of unquenched silicon material may require approximately 30J of impact energy.

[0065] Example 7: like Figures 2 to 6 As shown, this embodiment provides an electronic-grade polysilicon crushing device, applicable to the above-mentioned electronic-grade polysilicon crushing method, including: Heating unit 1 is used to hold an uncut whole native electronic-grade polycrystalline silicon rod 5; Electrode unit 2 is used to be electrically connected to the entire native electronic-grade polycrystalline silicon rod 5 and to pass current into the entire native electronic-grade polycrystalline silicon rod 5 so that the entire native electronic-grade polycrystalline silicon rod 5 is heated. Cooling unit 3 is used to contain the cooling medium; The transfer unit 4 is used to transfer the heated whole native electronic-grade polycrystalline silicon rod 5 from the heating unit 1 to the cooling medium in the cooling unit 3, so that the whole native electronic-grade polycrystalline silicon rod 5 will generate thermal shock cracks and break. The control unit, connected to the electrode unit 2, is used to determine the heating conditions based on the rod body parameters of the whole native electronic-grade polycrystalline silicon rod 5, the target crushed particle size and the temperature of the cooling medium, and to control the current output of the electrode unit 2 according to the heating conditions. The heating conditions include the heating temperature and the energizing parameters used to bring the whole native electronic-grade polycrystalline silicon rod 5 to the heating temperature.

[0066] Heating unit 1 can be a heating chamber, and cooling unit 3 can be a cooling chamber or a cooling water tank. Heating unit 1 and cooling unit 3 can be arranged in an upper and lower structure, so that the entire native electronic-grade polycrystalline silicon rod 5 can quickly enter the cooling medium after heating.

[0067] The heating unit 1 may have an openable upper structure and an openable bottom structure. When the upper structure is opened, it is convenient for a robotic arm or hoisting mechanism to place the entire native electronic-grade polycrystalline silicon rod 5 into the heating unit 1; when the bottom structure is opened, it is convenient for the heated silicon rod to fall into the cooling unit 3.

[0068] The bulkhead of heating unit 1 can be equipped with a circulating cooling structure, such as a circulating water system. The circulating water flow channel can adopt the form of a spiral baffle to reduce flow dead zones and improve heat transfer uniformity. The inner wall of heating unit 1 can be covered with high-purity quartz glass to isolate the silicon rod from the metal wall of the bulkhead and reduce impurity contamination in high-temperature environments.

[0069] The control unit can automatically calculate the heating temperature and power parameters based on the input silicon rod diameter, length, target particle size range, and cooling medium temperature. It can also call a preset current control curve for heating. By controlling the output of electrode unit 2 through the control unit, the repeatability of the thermal crushing process can be improved, and fluctuations caused by manual experience-based adjustments can be reduced.

[0070] Furthermore, the heating unit 1 is positioned above the cooling unit 3, and the electrode unit 2 is positioned on the heating unit 1; the transfer unit 4 includes a movable support structure 41 for supporting the entire native electronic-grade polycrystalline silicon rod 5, and for allowing the heated native electronic-grade polycrystalline silicon rod 5 to fall into the cooling medium when opened.

[0071] The supporting structure 41 may include multiple high-purity material bases, which are spaced apart along the length of the entire virgin electronic-grade polycrystalline silicon rod 5, for supporting the silicon rod during the heating stage. The high-purity material bases may be quartz bases or other materials that meet the cleanliness and temperature resistance requirements of electronic-grade polycrystalline silicon.

[0072] In one specific structure, the bottom of the heating unit 1 is provided with multiple triangular high-purity material bases, which are fixed to a movable base plate or the base plate of the heating unit 1. A buffer pad made of metal-coated high-temperature resistant elastic material can be provided between the base and the base plate to enable the support structure to withstand high temperatures and the weight of the silicon rod.

[0073] A high-purity material base allows for a distance between the silicon rod and the bottom of the heating unit 1, for example, more than 100mm. This reduces contact between the silicon rod and other components besides the support point, lowers the risk of contamination, and makes the circumferential heating environment of the silicon rod more uniform.

[0074] The movable support structure 41 remains closed or supported during the heating phase and opens during the rapid cooling phase. Since the cooling unit 3 is located below the heating unit 1, the silicon rod can enter the cooling medium without lateral transport, which helps to maintain the thermal shock temperature difference.

[0075] Furthermore, the electrode unit 2 includes an adjustable electrode 21, which is disposed on the heating unit 1 and is movable relative to the entire native electronic-grade polycrystalline silicon rod 5 to connect with the conductive connection portion of the entire native electronic-grade polycrystalline silicon rod 5.

[0076] The cooling unit 3 is provided with a partition 31, which is used to separate the graphite base 51 of the entire native electronic-grade polycrystalline silicon rod 5 from the rest of the entire native electronic-grade polycrystalline silicon rod 5 when the rod enters the cooling medium.

[0077] like Figure 6 As shown, the adjustable electrode 21 can form a socket-type contact with the graphite base 51. The adjustable electrode 21 has the ability to be adjusted in the vertical and horizontal directions, and can be used with silicon rods of different specifications and different positions of graphite base 51 to make the electrode in close contact with the graphite base 51 and reduce contact resistance fluctuations.

[0078] An insulating structure can be provided on the outside of the adjustable electrode 21, and a cooling jacket can be provided on the outside of the insulating structure. The insulating structure is used to reduce the risk of electrical connection between the electrode and other components of the heating unit 1, and the cooling jacket is used to reduce the temperature rise of the electrode during long-term energization. The cooling jacket can be made of stainless steel and cooled by circulating cooling water.

[0079] The cooling unit 3 may include an outer casing and an inner water tank. The outer casing may be made of stainless steel, and the inner water tank may be made of PP material to balance structural strength and corrosion resistance. A polycrystalline silicon plate may be laid at the bottom of the inner water tank as a heat insulation layer and a contact isolation layer to reduce contamination caused by direct contact between the silicon material and the bottom of the water tank.

[0080] The partition 31 is located at the bottom of the cooling unit 3 near the electrode. After the silicon rod is heated, it enters the cooling medium. The graphite base 51 can be separated from the silicon rod body by the partition 31. The graphite base 51 falls into one side of the partition 31, while the silicon rod body falls into the other side and is water-quenched and broken. This structure can simultaneously separate the graphite base 51 during the rapid cooling process, reducing the amount of subsequent manual sorting work.

[0081] Example 8: For process verification, to verify the influence of heating temperature and cooling medium temperature on the particle size distribution of the crushed material, a water quenching experiment was conducted. In the experiment, a whole native electronic-grade polycrystalline silicon rod was placed in the heating unit and the temperature was raised at a rate not exceeding 20℃ / min. Once the set temperature was reached, the rod was held in the heating unit for 5 minutes to allow the temperature inside and outside the silicon rod to become uniform. After holding, the silicon rod was rapidly immersed in water at 45℃ for quenching. After quenching, the silicon rod was removed and dried, surface cracks were observed, and then assisted crushing was performed with a small impact energy to statistically analyze the proportion of different particle size ranges.

[0082] The experimental results are shown in the table below:

[0083] The experimental results show that when the cooling medium temperature is 45℃, increasing the heating temperature from 100℃ to 400℃ significantly reduces the proportion of large particles larger than 100mm, while increasing the yield of qualified particle sizes from 10mm to 100mm. With further increases in heating temperature, the proportion of particles from 10mm to 50mm continues to increase, but the proportion of fine powder from 0mm to 10mm also rises. For a process target with a qualified particle size range of 10mm to 100mm, a higher yield is observed around 400℃. Figure 7 As shown; for process targets focusing on products with a fine powder range of 10mm to 50mm, the heating temperature can be appropriately increased based on the proportion of fine powder and production line requirements. Based on the temperature requirements for heating energy, the following optimal heating conditions within 30 minutes are derived: Figure 8 As shown.

[0084] The experimental results demonstrate that heating temperature, cooling medium temperature, and the resulting thermal shock temperature difference can affect crack propagation and final particle size distribution. By determining the heating conditions using the rod parameters, target crushing particle size, and cooling medium temperature as described in the claims, the energizing parameters can be adjusted according to different silicon rod specifications and product particle size requirements, thereby improving the ability to control crushing size.

[0085] In mass production processes, the critical thermal shock temperature difference can be calculated first based on material parameters, then the target thermal shock temperature difference can be selected based on the target crushing particle size, and the heating heat can be calculated in conjunction with the silicon rod size. For equipment with heat loss, a compensation coefficient can be set based on the theoretical heating heat, and then a current control curve can be generated. This preserves the original stress state of the entire native electronic-grade polycrystalline silicon rod, while also influencing crack propagation through temperature difference control, ultimately improving silicon rod utilization and target particle size product yield.

[0086] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A method for crushing electronic-grade polycrystalline silicon, characterized in that, Includes the following steps: Obtain the entire native electronic-grade polycrystalline silicon rod, and place the uncut entire native electronic-grade polycrystalline silicon rod in the heating area; Heating conditions are determined based on the rod body parameters, target crushing particle size, and cooling medium temperature of the entire native electronic-grade polycrystalline silicon rod. The heating conditions include the heating temperature and the electrical parameters used to bring the entire native electronic-grade polycrystalline silicon rod to the heating temperature. According to the energizing parameters, current is passed through the electrode electrically connected to the entire native electronic-grade polycrystalline silicon rod to heat the entire native electronic-grade polycrystalline silicon rod to the heating temperature. The heated whole native electronic-grade polycrystalline silicon rod is transferred to a cooling medium for rapid cooling, causing the whole native electronic-grade polycrystalline silicon rod to develop thermal shock cracks and break.

2. The method for crushing electronic-grade polycrystalline silicon according to claim 1, characterized in that, The entire native electronic-grade polycrystalline silicon rod retains conductive connection portions for growing the entire native electronic-grade polycrystalline silicon rod; According to the stated energizing parameters, current is supplied to the entire native electronic-grade polycrystalline silicon rod through electrodes electrically connected to it, including: Make the electrode contact the conductive connection portion; Current is supplied to the entire native electronic-grade polycrystalline silicon rod through the electrodes and the conductive connection.

3. The method for crushing electronic-grade polycrystalline silicon according to claim 1, characterized in that, The rod parameters include material parameters and dimensional parameters; Based on the rod parameters, target particle size, and cooling medium temperature of the entire native electronic-grade polycrystalline silicon rod, the heating conditions are determined, including the following steps: The critical thermal shock temperature difference required for the entire native electronic-grade polycrystalline silicon rod to generate thermal shock cracks is determined based on the material parameters. The target thermal shock temperature difference is determined based on the target crushing particle size and the critical thermal shock temperature difference. The heating temperature is determined based on the target thermal shock temperature difference and the temperature of the cooling medium. The energizing parameters are determined based on the dimensional parameters and the heating temperature.

4. The method for crushing electronic-grade polycrystalline silicon according to claim 3, characterized in that, Determining the energizing parameters based on the dimensional parameters and the heating temperature includes the following steps: The volume of the entire native electronic-grade polycrystalline silicon rod is determined based on the aforementioned size parameters; The heating temperature is determined based on the volume, density, and specific heat capacity of the entire native electronic-grade polycrystalline silicon rod, as well as the heating temperature and the cooling medium temperature. The power supply parameters are determined based on the heating temperature.

5. The method for crushing electronic-grade polycrystalline silicon according to claim 1, characterized in that, The heated whole native electronic-grade polycrystalline silicon rod is transferred to a cooling medium for rapid cooling, including the following steps: Remove the support structure from the entire native electronic-grade polycrystalline silicon rod; The heated whole native electronic-grade polycrystalline silicon rod is then dropped into the cooling medium located below the heating area.

6. The method for crushing electronic-grade polycrystalline silicon according to claim 1, characterized in that, When the heated whole native electronic-grade polycrystalline silicon rod is transferred to a cooling medium for rapid cooling, the graphite base of the whole native electronic-grade polycrystalline silicon rod is separated from the rest of the whole native electronic-grade polycrystalline silicon rod by a partition provided in the cooling medium. After the entire native electronic-grade polycrystalline silicon rod is rapidly cooled, a mechanical force is applied to the entire native electronic-grade polycrystalline silicon rod with the thermal shock crack, causing the entire native electronic-grade polycrystalline silicon rod to further break along the thermal shock crack.

7. An electronic-grade polycrystalline silicon crushing device, characterized in that, The method for crushing electronic-grade polycrystalline silicon applicable to any one of claims 1 to 6 includes: Heating unit for holding an uncut whole native electronic-grade polycrystalline silicon rod; An electrode unit is used to be electrically connected to the entire native electronic-grade polycrystalline silicon rod and to pass current through the entire native electronic-grade polycrystalline silicon rod so that the entire native electronic-grade polycrystalline silicon rod is heated. Cooling unit, used to contain cooling medium; A transfer unit is used to transfer the heated whole native electronic-grade polycrystalline silicon rod from the heating unit to the cooling medium in the cooling unit, so that the whole native electronic-grade polycrystalline silicon rod will generate thermal shock cracks and break. A control unit, connected to the electrode unit, is used to determine heating conditions based on the rod body parameters, target crushing particle size, and cooling medium temperature of the entire native electronic-grade polycrystalline silicon rod, and to control the current output of the electrode unit according to the heating conditions. The heating conditions include heating temperature and energizing parameters for bringing the entire native electronic-grade polycrystalline silicon rod to the heating temperature.

8. The electronic-grade polycrystalline silicon crushing equipment according to claim 7, characterized in that, The heating unit is disposed above the cooling unit, and the electrode unit is disposed on the heating unit; The transfer unit includes a movable support structure for supporting the entire native electronic-grade polycrystalline silicon rod and for allowing the heated native electronic-grade polycrystalline silicon rod to fall into the cooling medium when opened.

9. The electronic-grade polycrystalline silicon crushing equipment according to claim 7, characterized in that, The electrode unit includes an adjustable electrode, which is disposed on the heating unit and is movable relative to the whole native electronic-grade polycrystalline silicon rod to connect with the conductive connection portion of the whole native electronic-grade polycrystalline silicon rod. The cooling unit is provided with a partition, which is used to separate the graphite base of the entire native electronic-grade polycrystalline silicon rod from the rest of the rod when the rod enters the cooling medium.

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