diffusion furnace

Abstract

This utility model discloses a diffusion furnace, comprising: a furnace body with a heating chamber formed inside, the heating chamber including a first cavity segment and a second cavity segment arranged sequentially along a first direction; a resistance heating element arranged in the first cavity segment; and an electromagnetic heating element arranged in the second cavity segment. The diffusion furnace of this application has an electromagnetic heating element arranged inside the second cavity segment. Through electromagnetic heating, targeted heating of the solar cell can be achieved, thereby effectively increasing the temperature of the solar cell during the high-temperature propulsion stage without adjusting the internal process temperature of the cavity. This helps to increase the diffusion junction depth and avoids affecting the lifespan of the quartz element.

Description

Technical Field

[0001] This utility model belongs to the technical field of solar cell manufacturing equipment, specifically relating to a diffusion furnace. Background Technology

[0002] Boron diffusion is a core technology for manufacturing high-efficiency N-type solar cells. It involves doping boron atoms into a silicon wafer to form a PN junction, enabling the separation of photogenerated carriers and current output. The boron diffusion process mainly includes low-temperature deposition and high-temperature propulsion. Low-temperature deposition oxidizes and deposits the boron source onto the cell surface, while high-temperature propulsion drives the deposited boron atoms to diffuse deeper into the silicon lattice, forming a PN junction and optimizing the junction depth and concentration distribution.

[0003] The junction depth of boron diffusion is positively correlated with the process temperature during the high-temperature propagation stage. In the existing technology, resistance heating furnaces are commonly used for boron diffusion. In order to increase the junction depth of boron diffusion, the process temperature must be increased. However, increasing the process temperature will lead to a significant reduction in the life of quartz parts, resulting in higher costs. Utility Model Content

[0004] The purpose of this invention is to provide a diffusion furnace to solve the technical problem in the prior art where resistance heating furnaces are used for boron diffusion processes. In order to increase the junction depth of boron diffusion, the process temperature must be increased, but the lifespan of quartz parts is significantly reduced after the process temperature is increased.

[0005] To achieve the above objectives, this application provides a diffusion furnace, comprising:

[0006] The furnace body has a heating chamber inside, and the heating chamber includes a first cavity section and a second cavity section arranged sequentially along a first direction;

[0007] A resistance heating element is arranged within the first cavity section;

[0008] An electromagnetic heating element is arranged in the second cavity.

[0009] In one or more embodiments, the heating cavity further includes a third cavity disposed on the side of the second cavity away from the first cavity;

[0010] The resistance heating element is also arranged in the third cavity section.

[0011] In one or more embodiments, the resistance heating element is also arranged within the second cavity.

[0012] In one or more embodiments, the resistance heating element includes a plurality of resistance heating wires arranged on the cavity wall of the heating cavity.

[0013] In one or more embodiments, the resistance heating wire extends along the first direction, and a plurality of the resistance heating wires are arranged in a ring at intervals on the cavity wall of the heating chamber.

[0014] In one or more embodiments, the electromagnetic heating element includes a plurality of electromagnetic emission plates arranged on the cavity wall of the heating cavity.

[0015] In one or more embodiments, the electromagnetic emission plates extend along the first direction, and a plurality of the electromagnetic emission plates are arranged in a ring-shaped interval on the cavity wall of the heating chamber.

[0016] In one or more embodiments, the furnace body includes a shell and an insulation layer arranged sequentially from the outside to the inside.

[0017] In one or more embodiments, the wall of the heating chamber is formed with a receiving groove, and the resistance heating element and / or the electromagnetic heating element is embedded in the receiving groove.

[0018] In one or more embodiments, the furnace body includes a detachably connected furnace opening section and a furnace middle section;

[0019] The first cavity is formed inside the furnace opening section, and the second cavity is formed inside the furnace middle section.

[0020] In one or more embodiments, a plug-in structure is arranged at one end of the furnace middle section near the furnace opening section, and a matching plug-in structure is arranged at the end of the furnace opening section. The plug-in structure and the matching plug-in structure cooperate to position the furnace opening section and the furnace middle section.

[0021] In one or more embodiments, the furnace body further includes a furnace tail section located on the side of the furnace middle section opposite to the furnace opening section, the furnace tail section being detachably connected to the furnace middle section, and the heating chamber further includes a third cavity section formed inside the furnace tail section;

[0022] The resistance heating element is also arranged in the third cavity section.

[0023] In one or more embodiments, at least one end of the furnace middle section is provided with a plug-in structure, and the end of the furnace mouth section and / or the end of the furnace tail section is provided with a mating plug-in structure that matches the plug-in structure.

[0024] The advantages of this utility model, which differ from existing technologies, are:

[0025] The diffusion furnace of this application has an electromagnetic heating element arranged inside the second cavity section. Electromagnetic heating can achieve targeted heating of the solar cell, thereby effectively increasing the temperature of the solar cell during the high-temperature propulsion stage without adjusting the process temperature inside the cavity. This helps to increase the diffusion junction depth and avoids affecting the lifespan of the quartz component. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a graph showing the relationship between the process temperature and the diffusion junction depth of boron diffusion.

[0028] Figure 2 This is a cross-sectional structural schematic diagram of one embodiment of the diffusion furnace of this application;

[0029] Figure 3 These are temperature change curves of silicon wafers and quartz components under electromagnetic heating;

[0030] Figure 4 yes Figure 2 Schematic diagram of the cross-sectional structure of the middle AA surface;

[0031] Figure 5 yes Figure 2 Schematic diagram of the cross-sectional structure of the middle BB surface;

[0032] Figure 6 This is a cross-sectional structural schematic diagram of another embodiment of the diffusion furnace of this application;

[0033] Figure 7 yes Figure 6 Schematic diagram of the cross-sectional structure of the C-plane;

[0034] Figure 8 yes Figure 6 Schematic diagram of the cross-sectional structure of the DD plane;

[0035] Figure 9 This is a cross-sectional structural schematic diagram of another embodiment of the diffusion furnace of this application;

[0036] Figure 10 This is a cross-sectional structural schematic diagram of another embodiment of the diffusion furnace of this application.

[0037] Explanation of key figure labels:

[0038] Furnace body 100; Shell 101; Insulation layer 102; Receiving groove 103; Furnace opening section 104; Middle section of furnace 105; Tail section of furnace 106; Plug-in structure 107; Annular protrusion 1071; Interlocking plug-in structure 108; Groove 1081;

[0039] Heating chamber 200; First chamber section 201; Second chamber section 202; Third chamber section 203;

[0040] Resistance heating element 300; resistance heating wire 301;

[0041] Electromagnetic heating element 400; electromagnetic emission plate 401. Detailed Implementation

[0042] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0043] Increasing the junction depth in boron diffusion helps optimize carrier transport paths, improve contact interfaces, and enhance process robustness, directly improving the voltage, fill factor, and conversion efficiency of solar cells. The diffusion junction depth in the boron diffusion process is positively correlated with the process temperature during the high-temperature advancement phase; please refer to [link to relevant documentation]. Figure 1 , Figure 1 This is a graph showing the relationship between the process temperature and the diffusion junction depth of boron diffusion. (For example...) Figure 1 As shown, the junction depth of boron diffusion gradually increases as the process temperature gradually increases.

[0044] Existing boron diffusion furnaces generally employ resistance heating. To further increase the diffusion junction depth, the only solution is to raise the process temperature. However, increasing the process temperature significantly reduces the lifespan of the quartz components. Specifically, during long-term experiments, the applicant discovered that when the process temperature exceeds 1000℃, the lifespan of the quartz components decreases from over 6 months to less than 3 months, leading to higher costs and hindering cost reduction and efficiency improvement.

[0045] To address the aforementioned issues, the applicant has developed a novel diffusion furnace that achieves targeted heating of silicon wafers by introducing electromagnetic heating. This furnace can increase the diffusion junction depth without increasing the furnace's process temperature, thereby improving efficiency.

[0046] Specifically, please refer to Figure 2 , Figure 2 This is a cross-sectional structural schematic diagram of one embodiment of the diffusion furnace of this application.

[0047] like Figure 2 As shown, the diffusion furnace includes a furnace body 100, and a heating chamber 200 is formed inside the furnace body 100. The heating chamber 200 includes a first cavity section 201 and a second cavity section 202 arranged sequentially along a first direction x.

[0048] The first cavity 201 is equipped with a resistance heating element 300, and the second cavity 202 is equipped with an electromagnetic heating element 400.

[0049] Understandably, the solar cell can be sequentially inserted into the first cavity 201 and the second cavity 202. A low-temperature deposition process is carried out inside the first cavity 201. At this time, the temperature inside the first cavity 201 is maintained at a low temperature of 800~830℃ by resistance heating. The boron precursor inside the cavity is oxidized and deposited on the surface of the silicon wafer.

[0050] After the low-temperature deposition process is completed, the solar cell can enter the second cavity 202 for a high-temperature propulsion process. The second cavity 202 uses electromagnetic heating. Since silicon is a semiconductor material, its resistivity decreases at high temperatures. Therefore, the alternating electromagnetic field induces eddy currents inside the silicon wafer, directly generating Joule heating, thus achieving rapid heating of the silicon wafer. The quartz component used to support the solar cell is an insulator, so it cannot generate eddy currents, and its heating rate is significantly lower than that of the silicon wafer. This achieves targeted heating of the silicon wafer, significantly increasing the temperature of the silicon wafer while maintaining a constant process temperature inside the cavity. This leads to an increase in the diffusion junction depth and avoids the reduced lifespan caused by excessively high temperatures in the quartz component.

[0051] To further verify the above principle, the applicant conducted electromagnetic heating experiments with the same power on silicon wafers and quartz components. Specifically, during the experiment, the applicant used texturized silicon wafers (textured wafers), diffusion-processed silicon wafers (diffused wafers), and quartz blocks as samples, and electromagnetically heated them with the same 1.4 kW electromagnetic power, recording the temperature changes of the samples. Figure 3 , Figure 3 These are temperature change curves of silicon wafers and quartz components under electromagnetic heating.

[0052] like Figure 3 As shown, under the same electromagnetic power, the heating rate of the texturing sheet and the diffuser sheet is significantly higher than that of the quartz block, verifying the targeted heating principle of this application.

[0053] The structure of the diffusion furnace in this embodiment is described in detail below. Please refer to [link / reference]. Figure 4 and Figure 5 , Figure 4 yes Figure 2 Schematic diagram of the cross-sectional structure of plane AA in the middle. Figure 5 yes Figure 2Schematic diagram of the cross-sectional structure of the middle BB plane.

[0054] like Figure 4 and Figure 5 As shown, in this embodiment, the furnace body 100 includes a shell 101 and an insulation layer 102 arranged sequentially from the outside to the inside, thereby reducing heat loss during heating. In one embodiment, the shell 101 may be made of stainless steel, and the insulation layer 102 may be made of alumina fiber.

[0055] like Figure 4 As shown, in this embodiment, the resistance heating element 300 includes a plurality of resistance heating wires 301 arranged on the cavity wall of the heating cavity 200. The resistance heating wires 301 can be infrared heating wires, alloy heating wires, silicon carbide heating rods, graphite heating rods, PTC ceramic heating rods, etc., all of which can achieve the effect of this embodiment.

[0056] In this embodiment, the resistance heating wire 301 extends along the first direction x, and multiple resistance heating wires 301 are arranged in a ring at intervals on the cavity wall of the heating chamber 200, thereby ensuring the uniformity of heating throughout the first cavity section 201. Of course, in other embodiments, the resistance heating wire 301 can also be arranged in other ways, such as in a ring, or multiple resistance heating wires 301 can be arranged sequentially at intervals along the first direction x, etc., as long as the uniform arrangement of the resistance heating wire 301 inside the first cavity is ensured, the effect of this embodiment can be achieved.

[0057] like Figure 5 As shown, in this embodiment, the electromagnetic heating element 400 includes a plurality of electromagnetic emitting plates 401 arranged on the cavity wall of the heating cavity 200. The electromagnetic emitting plate 401 can be a coil-type electromagnetic emitting plate 401, specifically a synchronous induction type, an asynchronous induction type, a planar spiral coil type, etc., all of which can achieve the effect of this embodiment.

[0058] In this embodiment, the electromagnetic emission plate 401 extends along the first direction x, and multiple electromagnetic emission plates 401 are arranged in a ring at intervals on the cavity wall of the heating cavity 200, thereby ensuring the uniformity of electromagnetic signals throughout the second cavity segment 202. Of course, in other embodiments, the electromagnetic emission plates 401 can also be arranged in other ways, such as in a ring, or multiple electromagnetic emission plates 401 can be arranged sequentially at intervals along the first direction x, etc., as long as the uniformity of electromagnetic signals throughout the second cavity segment 202 can be ensured, the effect of this embodiment can be achieved.

[0059] In the above embodiment, only an electromagnetic heating element 400 is arranged inside the second cavity 202. In another embodiment, to improve the heating rate inside the second cavity 202, a resistance heating element 300 may also be arranged inside the second cavity 202. Please refer to [link to relevant documentation]. Figure 6 , Figure 6 This is a cross-sectional structural schematic diagram of another embodiment of the diffusion furnace of this application.

[0060] like Figure 6 As shown, the second cavity section 202 of the diffusion furnace is equipped with both resistance heating elements 300 and electromagnetic heating elements 400, thereby improving the heating rate. Specifically, the resistance heating wire 301 and the electromagnetic emission plate 401 can be arranged alternately in a ring to ensure the uniformity of the heating rate at each location.

[0061] Furthermore, in Figure 4 and Figure 5 In the illustrated embodiment, the resistance heating wire 301 and the electromagnetic emission plate 401 protrude from the cavity wall of the heating chamber 200, causing the electromagnetic signal and heat to dissipate outwards, which is detrimental to improving heating efficiency. To solve this problem, please refer to... Figure 7 and Figure 8 , Figure 7 yes Figure 6 A cross-sectional view of the C-plane. Figure 8 yes Figure 6 A schematic diagram of the cross-sectional structure of the DD plane.

[0062] like Figure 7 and Figure 8 As shown, in this embodiment, the inner wall of the insulation layer 102 is also provided with a receiving groove 103. The resistance heating wire 301 and the electromagnetic emission plate 401 are embedded in the receiving groove 103, so that electromagnetic signals and heat can be emitted radially along the heating cavity 200, which effectively improves the heating efficiency and optimizes the internal layout.

[0063] It should be noted that in this embodiment, the furnace body 100 includes a shell 101 and an insulation layer 102, and the receiving groove 103 is arranged on the inner wall of the insulation layer 102. In other embodiments, when the furnace body 100 adopts other structures, the receiving groove 103 can also be arranged on the innermost inner wall, which can also achieve the effect of this embodiment.

[0064] In addition, in this embodiment, the resistance heating element 300 includes a plurality of resistance heating wires 301, and the electromagnetic heating element 400 includes a plurality of electromagnetic emission plates 401; in other embodiments, when the resistance heating element 300 and the electromagnetic heating element 400 adopt other heating elements commonly used in the art, they can also adopt an embedded installation method, and both can achieve the effect of this embodiment.

[0065] In the above embodiments, the heating chamber 200 includes a first cavity section 201 and a second cavity section 202. The solar cell sequentially passes through the first cavity section 201 and the second cavity section 202 to complete the boron diffusion process. Afterward, the solar cell directly leaves the diffusion furnace through the second cavity section 202, which results in an excessively high temperature gradient, potentially affecting the performance of the solar cell. To solve this problem, please refer to [link to relevant documentation]. Figure 9 , Figure 9 This is a cross-sectional structural schematic diagram of another embodiment of the diffusion furnace of this application.

[0066] like Figure 9 As shown, in this embodiment, the heating cavity 200 also includes a third cavity section 203, which is located on the side of the second cavity section 202 away from the first cavity section 201, and a resistance heating element 300 is also arranged inside the third cavity section 203.

[0067] Specifically, in this embodiment, the structure and arrangement of the resistance heating element 300 inside the third cavity 203 are the same as those of the resistance heating element 300 inside the first cavity 201, that is, it includes a plurality of resistance heating wires 301 arranged in a ring at intervals; in other embodiments, the structure and arrangement of the resistance heating element 300 inside the third cavity 203 may also be different from those of the resistance heating element 300 inside the first cavity 201, and all of these can achieve the effect of this embodiment.

[0068] Understandably, the solar cells that have undergone the high-temperature propulsion process can enter the third cavity 203. The third cavity 203 can maintain a relatively low temperature of 750~780℃, which allows for a cooling process on the solar cells that have undergone the high-temperature propulsion process. After the cooling process, the solar cells can be removed from the diffusion furnace, effectively reducing the temperature gradient.

[0069] In all the above embodiments, the furnace body 100 is a one-piece structure, which requires replacement of the entire unit when partial damage occurs, resulting in high costs. The applicant has found in long-term experiments that the furnace opening and tail positions of the furnace body 100 experience greater thermal shock, thus the damage rate at these positions is much higher than that at the middle of the furnace body 100.

[0070] To reduce the replacement cost of furnace body 100 after damage, please refer to Figure 10 , Figure 10 This is a cross-sectional structural schematic diagram of another embodiment of the diffusion furnace of this application.

[0071] like Figure 10 As shown, in this embodiment, the furnace body 100 adopts a segmented design and includes a furnace mouth section 104, a furnace middle section 105 and a furnace tail section 106 arranged sequentially along the first direction x. The furnace mouth section 104 and the furnace middle section 105 are detachably connected, and the furnace middle section 105 and the furnace tail section 106 are detachably connected.

[0072] The first cavity 201 can be formed inside the furnace opening section 104, the second cavity 202 can be formed inside the furnace middle section 105, and the third cavity 203 can be formed inside the furnace tail section 106, thereby facilitating the arrangement and maintenance of the heating elements.

[0073] In this embodiment, the furnace mouth section 104 and the furnace middle section 105, as well as the furnace middle section 105 and the furnace tail section 106, can be fixed by any detachable connection method commonly used in the art, such as bolt fixing, clamp fixing, buckle fixing, etc., all of which can achieve the effect of this embodiment, and will not be elaborated here.

[0074] To ensure the positioning accuracy between the furnace opening section 104, the middle section 105, and the tail section 106, in this embodiment, both ends of the middle section 105 are provided with plug-in structures 107, and the ends of the furnace opening section 104 and the tail section 106 are provided with mating plug-in structures 108 that match the plug-in structures 107. The plug-in structures 107 and the mating plug-in structures 108 cooperate to achieve positioning.

[0075] Specifically, in this embodiment, the plug-in structure 107 includes a ring of annular protrusions 1071 arranged on the end face of the insulation layer 102 in the middle section 105 of the furnace, and the mating plug-in structure 108 includes a ring of grooves 1081 arranged on the end face of the insulation layer 102 in the furnace opening section 104 and the end face of the insulation layer 102 in the furnace tail section 106. The shape of the grooves 1081 matches the annular protrusions 1071, thereby achieving axial positioning of the three.

[0076] Of course, in other embodiments, the plug-in structure 107 and the mating plug-in structure 108 can also adopt other mating locking structures commonly used in the art, or the plug-in structure 107 can also be a groove 1081, and the mating plug-in structure 108 can also be a matching annular protrusion 1071, etc., all of which can achieve the effect of this embodiment.

[0077] It should be noted that this embodiment only exemplifies the configuration in which the furnace body 100 is composed of a detachably connected furnace opening section 104, a furnace middle section 105, and a furnace tail section 106. In other embodiments, the furnace body 100 may also be composed only of the detachably connected furnace opening section 104 and furnace middle section 105. Alternatively, the furnace middle section 105 and furnace tail section 106 may be integrally formed, with the furnace opening section 104 and furnace middle section 105 being detachably connected. Alternatively, the furnace middle section 105 and furnace opening section 104 may be integrally formed, with the furnace tail section 106 and furnace middle section 105 being detachably connected. Alternatively, the plug-in structure 107 may be arranged only at one end of the furnace middle section 105, and so on. These will not be elaborated further here.

[0078] The segmented structure of the furnace body 100 allows for individual replacement of the furnace mouth section 104 and / or the furnace tail section 106 when damaged, eliminating the need to replace the entire furnace body 100 and significantly reducing costs.

[0079] The following details a boron diffusion process applicable to the diffusion furnace of this embodiment, specifically including:

[0080] 1. Load the silicon wafer into the quartz boat and enter the first cavity 201, and control the internal temperature of the first cavity 201 to 750℃;

[0081] 2. Evacuate the heating chamber 200 to 700Pa to maintain a low-pressure environment, and then evacuate it again to 100Pa to further purify the atmosphere inside the furnace.

[0082] 3. Control the temperature inside the first cavity 201 to gradually rise to 780℃, and perform a sealing test;

[0083] 4. The temperature inside the first cavity 201 is raised to 800℃, and oxygen is introduced to form a thin oxide layer on the surface of the silicon wafer;

[0084] 5. Three-stage deposition was used, with boron source gas introduced during each deposition and impurity gas purged after each deposition. The deposition temperatures for the three stages were 810℃, 820℃, and 830℃, respectively.

[0085] 6. Adjust the quartz boat into the second cavity 202. The internal temperature of the second cavity 202 is 917℃. Purge with nitrogen and then keep it at 917℃.

[0086] 7. The second chamber 202 is heated to 995℃ and kept at that temperature, while oxygen is introduced simultaneously to achieve boron diffusion and surface oxidation;

[0087] 8. Adjust the quartz boat into the third cavity 203. The temperature inside the third cavity 203 is controlled at 780℃, and then gradually reduced to 750℃. Remove the quartz boat from the furnace body 100.

[0088] Based on the diffusion furnace described above, by arranging an electromagnetic heating element 400 inside the second cavity section 202, the solar cell can be targeted for heating through electromagnetic heating. This effectively increases the temperature of the solar cell during the high-temperature propulsion stage without adjusting the process temperature inside the cavity, which helps to increase the diffusion junction depth and avoids affecting the lifespan of the quartz component.

[0089] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this disclosure. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0090] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A diffusion furnace characterized by comprising: include: The furnace body has a heating chamber inside, which includes a first cavity section and a second cavity section arranged sequentially along a first direction. A resistance heating element is arranged within the first cavity section; An electromagnetic heating element is arranged in the second cavity.

2. The diffusion furnace according to claim 1, characterized by The heating cavity further includes a third cavity section arranged on the side of the second cavity section opposite to the first cavity section; The resistance heating element is also arranged in the third cavity section.

3. The diffusion furnace according to claim 1, characterized by The resistance heating element is also arranged in the second cavity.

4. The diffusion furnace according to any one of claims 1 to 3, characterized in that, The resistance heating element includes a plurality of resistance heating wires arranged on the cavity wall of the heating chamber.

5. The diffusion furnace according to claim 4, characterized by The resistance heating wire extends along the first direction, and a plurality of the resistance heating wires are arranged in a ring at intervals on the cavity wall of the heating chamber.

6. The diffusion furnace of claim 1, wherein The electromagnetic heating element includes several electromagnetic emission plates arranged on the cavity wall of the heating chamber.

7. The diffusion furnace according to claim 6, characterized in that, The electromagnetic emission plates extend along the first direction, and a plurality of the electromagnetic emission plates are arranged in a ring at intervals on the cavity wall of the heating chamber.

8. The diffusion furnace of claim 1, wherein The furnace body includes a shell and an insulation layer arranged sequentially from the outside to the inside; and / or, The heating chamber has a receiving groove formed in its cavity wall, and the resistance heating element and / or the electromagnetic heating element are embedded in the receiving groove.

9. The diffusion furnace of claim 1, wherein The furnace body includes a detachably connected furnace opening section and a furnace middle section; The first cavity is formed inside the furnace opening section, and the second cavity is formed inside the furnace middle section.

10. The diffusion furnace according to claim 9, characterized in that, A plug-in structure is arranged at one end of the furnace middle section near the furnace mouth section, and a matching plug-in structure is arranged at the end of the furnace mouth section. The plug-in structure and the matching plug-in structure cooperate to position the furnace mouth section and the furnace middle section.

11. The diffusion furnace of claim 9, wherein The furnace body also includes a furnace tail section located on the side of the furnace middle section opposite to the furnace opening section, the furnace tail section being detachably connected to the furnace middle section, and the heating chamber also includes a third chamber section formed inside the furnace tail section; The resistance heating element is also arranged in the third cavity section.

12. The diffusion furnace of claim 11, wherein At least one end of the middle section of the furnace is provided with a plug-in structure, and the end of the furnace opening section and / or the end of the furnace tail section are provided with a matching plug-in structure that matches the plug-in structure.

Images