A growth table for synthesizing diamond

Abstract

The utility model provides a kind of for synthetic diamond's growth platform belongs to chemical vapor deposition method preparation diamond technical field.Growth platform includes upper table, middle table and lower table, and middle table is enclosed with upper table and lower table to form upper cooling cavity and lower cooling cavity, and upper table and / or middle table are equipped with at least two spiral grooves extending in plane helical shape from center to periphery to form at least two spiral flow channels between upper table and middle table, each spiral flow channel forms upper cooling cavity, and the center end of each spiral flow channel corresponds and communicates with the center hole of middle table, and the position corresponding to the periphery end of each spiral flow channel on middle table is equipped with communication hole respectively.Because there are more than two spiral flow channels, compared with single spiral flow channel, in the case of same cooling area, the more the number of spiral flow channels, the shorter the length of single spiral flow channel, that is, the shorter the flow path of coolant, so that the temperature rise of coolant can be reduced, and the cooling and heat dissipation effect of coolant on growth platform is improved.

Description

Technical Field

[0001] This utility model relates to a growth stage for synthesizing diamond, belonging to the field of diamond preparation technology by chemical vapor deposition. Background Technology

[0002] Microwave plasma chemical vapor deposition (MPCVD) is the preferred method for preparing high-quality single-crystal diamond. The temperature required for single-crystal diamond growth has a significant impact on the synthesis quality and efficiency. Controlling the temperature and uniformity during the synthesis of single-crystal diamond wafers is particularly important for the efficient preparation of high-quality single-crystal diamond.

[0003] The growth of single-crystal diamond is carried out on a growth stage assembly, which includes a water-cooled stage and a growth substrate. Traditionally, the growth substrate is a solid molybdenum stage. This type of growth substrate alters its overall temperature and heat dissipation distribution by adjusting its combination (integral, double-layer, triple-layer, or multi-layer configurations using high thermal conductivity copper as the bottom layer) and structural form (purely solid, or with a centrally located annular groove), thereby ensuring the temperature and uniformity of the single-crystal diamond wafer. This method introduces limitations to temperature control. Each temperature test requires a shutdown to adjust the growth substrate combination until a suitable combination is achieved. Furthermore, under high power and high pressure conditions (where the growth temperature of single-crystal diamond is far higher than the required process temperature), relying solely on the growth substrate to transfer heat to the water-cooled stage is insufficient for temperature control.

[0004] In response, Chinese invention patent application CN116695099A discloses a liftable MPCVD growth stage. This growth stage includes a lower sealing plate, a lifting drive device, a first water-cooling assembly, and a second water-cooling assembly. A diamond growth stage is located on the top of the lower sealing plate. The diamond growth stage has a lifting channel and a positioning ring for placing a molybdenum support. The lifting drive device is connected to the positioning ring to control its movement within the lifting channel. The first water-cooling assembly includes a first lifting water pipe and a second lifting water pipe nested from the outside in. The bottoms of the two lifting water pipes are connected to a first water nozzle sleeve, and the tops are respectively connected to a first cooling water inlet plate and a first cooling water outlet plate. A sealing water plate is provided below the positioning ring. A first cooling water inlet chamber is formed between the first cooling water inlet plate and the sealing water plate, and a first cooling water outlet chamber is formed between the first cooling water inlet plate and the first cooling water outlet plate. Coolant enters the upper first cooling water inlet chamber through the second lifting water pipe, flows from the center to the surrounding area, and enters the lower first cooling water outlet chamber through the first connecting water hole on the first cooling water inlet plate. After converging from the surrounding area to the center, it is discharged through the annulus between the first lifting water pipe and the second lifting water pipe, thereby cooling the positioning ring.

[0005] The second water-cooling assembly includes a fourth cooling water pipe, a third cooling water pipe, and a connecting water pipe nested from the outside in. The lower ends of the three water pipes are connected to the second water nozzle sleeve, and the upper ends are respectively connected to the second cooling water outlet plate, the second cooling water inlet plate, and the diamond growth stage. The second cooling water inlet plate and the diamond growth stage form a second cooling water inlet chamber, and the second cooling water outlet plate and the second cooling water outlet plate form a second cooling water outlet chamber. The coolant enters the upper second cooling water inlet chamber through the annulus between the connecting water pipe and the third cooling water pipe, flows from the center to the periphery, and enters the lower second cooling water outlet chamber through the second connecting water hole on the second cooling water inlet plate. After converging from the periphery to the center, it is discharged through the annulus between the fourth cooling water pipe and the third cooling water pipe.

[0006] The aforementioned sealing water plate (i.e., the first upper stage), the first cooling water inlet plate (i.e., the first middle stage), and the first cooling water outlet plate (i.e., the first lower stage) constitute the growth stage for placing the molybdenum support (i.e., the molybdenum stage). The diamond growth stage (i.e., the second upper stage), the second cooling water inlet plate (i.e., the second middle stage), and the second cooling water outlet plate (i.e., the second lower stage) constitute the water-cooled stage. Both the growth stage and the water-cooled stage include an upper stage, a middle stage, and a lower stage, and are all indispensable growth stages for synthesizing diamond. Although the growth stage is equipped with a cooling water inlet cavity (i.e., the upper cooling cavity) and a cooling water outlet cavity (i.e., the lower cooling cavity), the upper cooling cavity, which plays a major role in heat dissipation, is a large open cavity with the shortest path for coolant flow. That is, after entering the large open cavity, the coolant will directly reach the connecting water hole (i.e., the connecting hole) on the middle stage and then flow into the lower cooling cavity, resulting in poor cooling effect on the growth stage.

[0007] Existing technologies include methods that use planar spiral flow channels. While this method extends the flow path of the coolant, the coolant flows in a single line. To achieve a larger cooling area, the number of spiral turns must be increased, which leads to an excessively long flow path. As the flow path progresses, the coolant temperature rises higher and the cooling effect deteriorates. Therefore, when applied to a growth platform, the overall cooling and heat dissipation effect is poor. Utility Model Content

[0008] The purpose of this invention is to provide a growth stage for synthesizing diamond, so as to solve the problem of poor cooling and heat dissipation of the growth stage in the prior art.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A growth stage for synthesizing diamond includes an upper stage, a middle stage, and a lower stage fixed together. The middle stage, together with the upper and lower stages, forms an upper cooling cavity and a lower cooling cavity. The middle stage is provided with a connecting hole that connects the upper and lower cooling cavities. The upper stage and / or the middle stage are provided with at least two spiral grooves extending in a planar spiral shape from the center to the periphery to form at least two spiral flow channels between the upper and middle stages. Each spiral flow channel together forms the upper cooling cavity. The center end of each spiral flow channel corresponds to and connects with the center hole of the middle stage. The middle stage is provided with connecting holes at positions corresponding to the periphery ends of each spiral flow channel.

[0010] The beneficial effects of the above technical solution are as follows: This utility model is an improved invention. When the coolant enters the upper cooling chamber through the central hole of the middle platform, it will be distributed into each spiral flow channel, flowing from the central end of the spiral flow channel to the outer end, and then entering the lower cooling chamber through the corresponding connecting hole, thus achieving cooling and heat dissipation for the growth stage. Alternatively, the coolant first enters the lower cooling chamber, then enters the outer end of each spiral flow channel in the upper cooling chamber through the connecting hole, flows from the outer end to the central end, and finally flows out through the central hole of the middle platform, achieving cooling and heat dissipation for the growth stage. Since there are two or more spiral flow channels, compared with a single spiral flow channel, under the same cooling area, the more spiral flow channels there are, the shorter the length of a single spiral flow channel, that is, the shorter the flow path of the coolant. This can reduce the temperature rise of the coolant and improve the cooling and heat dissipation effect of the coolant on the growth stage.

[0011] Furthermore, the middle platform and / or the lower platform are provided with an annular groove and at least two straight grooves connecting the central hole of the lower platform and the annular groove, so as to form an annular flow channel and at least two straight flow channels between the middle platform and the lower platform. The annular flow channel and each straight flow channel together form the lower cooling cavity. Each connecting hole corresponds vertically to the annular flow channel and has a distance to the intersection of the annular flow channel and any straight flow channel.

[0012] Furthermore, the outer ends of each spiral flow channel are evenly distributed in the same circumferential direction, the intersections of the annular flow channel and each straight flow channel are evenly distributed in the same circumferential direction, and the distances from each connecting hole to two adjacent intersections are equal.

[0013] Furthermore, the center of the middle platform and / or the lower platform is provided with a central converging groove communicating with the straight groove, so as to form a central converging cavity communicating with the straight flow channel between the middle platform and the lower platform.

[0014] Furthermore, the upper, middle, and lower stages are positioned using positioning pins.

[0015] Furthermore, the positioning pins include at least two circumferentially distributed inner positioning pins installed between the middle platform and the lower platform, and at least two circumferentially distributed outer positioning pins installed between the upper platform and the lower platform.

[0016] Furthermore, the center platform is provided with inner positioning holes for installing each inner positioning pin, and the inner positioning holes are arranged one-to-one on the radial inner side of the connecting hole.

[0017] Furthermore, the upper and lower platforms are fixedly connected near the outer circle by a plurality of circumferentially distributed screws. Both the upper and lower platforms are provided with screw mounting holes for installing the screws and external positioning holes for installing each external positioning pin. The external positioning holes are located between two adjacent screw mounting holes.

[0018] Furthermore, the upper and lower platforms are fixedly connected near the outer circle by multiple circumferentially distributed screws. A sealing ring is provided on the inner side of the screw connection position between the upper and lower platforms. The upper or lower platform is provided with a mounting groove for installing the sealing ring, and the mounting groove is located on the periphery of each spiral flow channel.

[0019] Furthermore, both the annular groove and the straight groove are set on the lower platform, the spiral groove is set on the upper platform, the middle platform is a flat plate structure, and the upper or lower platform is provided with a stepped groove for the middle platform to be embedded. Attached Figure Description

[0020] Figure 1 This is a front sectional view of the growth stage for synthesizing diamond according to this utility model in use. Figure 2 This is a perspective view of the growth stage for synthesizing diamond according to this utility model in use. Figure 3 This is a front sectional view of the growth stage for synthesizing diamond, as a water-cooled stage, according to the present invention. Figure 4 This is a front sectional view of the growth stage for synthetic diamond of this utility model in use as a growth substrate. Figure 5 for Figure 1 and Figure 2 Detailed structural diagram of the sealing device; Figure 6 This is an exploded view of the growth stage used in the synthesis of diamond according to this utility model, which serves as a growth substrate. Figure 7 This is an exploded view of the growth stage for synthesizing diamond, as a growth substrate, from another perspective.

[0021] In the diagram: 1. Cavity; 2. Cavity base plate; 3. Water-cooled stage assembly; 3-1. Copper disk; 3-2. Water distribution plate; 3-3. Antenna disk; 3-4. Sealing groove; 3-5. Fastening screw; 3-6. First sealing ring; 3-7. Copper disk connecting pipe; 3-8. Water distribution plate connecting pipe; 3-9. Antenna mast; 4. Growth base assembly; 4-1. Upper stage; 4-1-1. Spiral groove; 4-1-2. Upper outer positioning hole; 4-1-3. Threaded blind hole; 4-1-4. Mounting groove; 4-2. Middle stage; 4-2-1. Middle stage center hole; 4-2-2. Connecting hole; 4-2 -3. Inner positioning hole; 4-3. Lower platform; 4-3-1. Center hole of lower platform; 4-3-2. Annular groove; 4-3-3. Straight groove; 4-3-4. Center converging groove; 4-3-5. Lower inner positioning hole; 4-3-6. Lower outer positioning hole; 4-3-7. Screw through hole; 4-3-8. Step groove; 4-4. Second sealing ring; 4-5. Beryllium copper spiral tube; 4-6. Middle platform connecting pipe; 4-7. Lower platform connecting pipe; 5. Quartz ring; 6. Molybdenum platform; 7. Mode converter; 8. Spring; 9. Clamping ring threaded fitting; 10. Mounting frame; 10-1 11. Fixing ring; 11. First water collector; 11-1. First upper block; 11-2. First lower block; 11-3. First plug; 11-4. First nut cap; 11-5. First sealing ring; 11-6. Third sealing ring; 11-7. Fourth sealing ring; 11-8. Fifth sealing ring; 11-9. First lower connector; 11-10. First upper connector; 12. Second water collector; 12-1. Second upper block; 12-2. Second lower block; 12-2-1. Side threaded hole; 12-3. Second plug; 12-4. Second nut cap; 12- 5. Second sealing ring; 12-6. Sixth sealing ring; 12-7. Outer sealing ring; 12-8. Inner sealing ring; 12-9. Second lower connector; 12-10. Second upper connector; 12-11. Connecting bolt; 13. Sealing device; 13-1. Telescopic cover; 13-2. Upper collar; 13-3. Upper nut cap; 13-4. Upper sealing ring; 13-5. Lower collar; 13-6. Lower nut cap; 13-7. Lower sealing ring; 14. Lifting motor; 15. Displacement sensor; 16. Clamp; 17. Round flange; 18. Fixing bolt; 19. Base plate. Detailed Implementation

[0022] In view of the technical problems existing in the prior art, the basic inventive concept of this utility model is to set two or more spiral flow channels in the growth stage. Under the same cooling area, the length of each spiral flow channel is not very long, which shortens the flow path of the coolant and improves the cooling and heat dissipation effect.

[0023] The features and performance of this utility model will be further described in detail below with reference to the embodiments.

[0024] Embodiment of the growth stage for synthesizing diamond in this utility model: The growth stage for synthesizing diamond can be a growth base for placing a molybdenum stage, or a water-cooled stage for cooling the growth base. In the first embodiment, both the growth base and the water-cooled stage are improved growth stages, that is, both utilize the above-described inventive concept and have two or more spiral flow channels inside. In other embodiments, only the growth base may be an improved growth stage, while the water-cooled stage is the same as the prior art; conversely, only the water-cooled stage may be an improved growth stage, while the growth base is the same as the prior art.

[0025] like Figure 1 The image shows an MPCVD apparatus, which includes a chamber 1, a chamber base plate 2, a water-cooled stage assembly 3, and a growth stage assembly 4. The water-cooled stage assembly 3 includes a water-cooled stage and a connecting pipe that is connected to the water-cooled stage and extends downward. The growth stage assembly 4 includes a growth stage and a connecting pipe that is connected to the growth stage and extends downward. The top surface of the growth stage is used to place a molybdenum stage 6, on which single-crystal diamond is grown.

[0026] Combination Figure 1 and Figure 2 As shown, the water-cooled stage assembly 3 and the growth base assembly 4 are assembled together. The main body is located inside the cavity 1 and mounted on the quartz ring 5. The connecting pipe extends through the central hole of the cavity base plate 2 to the bottom of the cavity base plate 2. From top to bottom, the outside of the connecting pipe is equipped with a mode converter 7, a spring 8, and a threaded retainer 9. The mode converter 7 is located below the cavity base plate 2. The threaded retainer 9 is tightly mounted on the outermost tube of the connecting pipe by a retainer. By rotating the threaded sleeve, the spring 8 can be squeezed, thereby enabling the water-cooled stage assembly 3 to squeeze the quartz ring 5 and the cavity base plate 2, thus connecting them into one unit.

[0027] In this embodiment, both the water-cooled stage and the growth platform are improved growth platforms. First, taking the growth platform as an example, its structure will be described. For example... Figure 4 , Figure 6 and Figure 7 As shown, the growth platform includes an upper platform 4-1, a middle platform 4-2, and a lower platform 4-3 fixed together. An upper cooling cavity is formed between the middle platform 4-2 and the upper platform 4-1, and a lower cooling cavity is formed between the middle platform 4-2 and the lower platform 4-3. A connecting hole 4-2-2 is provided on the middle platform 4-2 to connect the upper and lower cooling cavities.

[0028] In this embodiment, the middle platform 4-2 is a flat plate structure. The upper platform 4-1 has two spiral grooves 4-1-1 extending in a planar spiral shape from the center to the periphery. The spiral grooves 4-1-1 are formed on the end face of the upper platform 4-1 facing the middle platform 4-2, forming two spiral flow channels between the upper platform 4-1 and the middle platform 4-2. The two spiral flow channels together form the aforementioned upper cooling cavity. The central end of each spiral flow channel (the end closer to the center of the middle platform) corresponds to and is connected to the central hole 4-2-1 of the middle platform. The middle platform 4-2 has connecting holes 4-2-2 at positions corresponding to the peripheral ends of each spiral flow channel (the ends farther from the center of the middle platform), that is, there are two connecting holes 4-2-2.

[0029] When the coolant enters the upper cooling chamber through the central hole 4-2-1 of the middle platform, it is distributed into various spiral channels. The coolant flows from the center end of each spiral channel to the outer edge, and then through the corresponding connecting hole 4-2-2 into the lower cooling chamber, thus cooling the growth substrate. Alternatively, the coolant first enters the lower cooling chamber, then through the connecting hole 4-2-2 into the outer edges of each spiral channel in the upper cooling chamber, flowing from the outer edges to the center end, and finally exiting through the central hole 4-2-1, again cooling the growth substrate. Since there are two or more spiral channels, compared to a single spiral channel, for the same cooling area, the more spiral channels there are, the shorter the length of a single spiral channel, meaning a shorter coolant flow path. This reduces the coolant temperature rise and improves the cooling effect on the growth substrate. Of course, the two spiral channels also increase the coolant flow rate, further enhancing the cooling effect on the growth substrate.

[0030] In this embodiment, the central ends of the two spiral channels are connected, and the two spiral channels are arranged symmetrically, that is, the two spiral channels have the same shape and length, and their outer ends are evenly distributed in the same circumferential direction, i.e., arranged at 180°. The flow capacity and heat dissipation effect of the two spiral channels are consistent. In other embodiments, depending on the specific dimensions of the upper platform 4-1 and the spiral groove 4-1-1, more than three spiral grooves 4-1-1 can be set to form more than three spiral channels. The shape and length of each spiral channel can be equal, and the outer ends can be evenly distributed in the same circumferential direction. Of course, they can also be unequal, in which case the outer ends are not evenly distributed. Furthermore, regardless of whether there are two spiral channels or three or more spiral channels, the central ends of each spiral channel do not need to be connected; they are separated, as long as the central end is connected to the central hole 4-2-1 of the middle platform, ensuring that the coolant can flow into each spiral channel through the central hole 4-2-1 of the middle platform, or that the coolant in each spiral channel can flow into the central hole 4-2-1 of the middle platform.

[0031] In other embodiments, the spiral groove can also be provided on the middle platform 4-2, located on the end face of the middle platform 4-2 facing the upper platform 4-1. In this case, the part of the upper platform 4-1 facing the middle platform 4-2 is flat, thus forming a spiral flow channel together with the spiral groove on the middle platform 4-2. Of course, in other embodiments, spiral grooves can also be provided on the opposite end faces of the upper platform 4-1 and the middle platform 4-2, with the spiral grooves on both sides communicating with each other to form a spiral flow channel.

[0032] In this embodiment, the lower platform 4-3 is provided with an annular groove 4-3-2 and two straight grooves 4-3-3 connecting the lower platform center hole 4-3-1 and the annular groove 4-3-2, so that the middle platform 4-2 and the lower platform 4-3 form an annular flow channel and two straight flow channels. The annular flow channel and the two straight flow channels together form the lower cooling cavity, and each connecting hole 4-2-2 corresponds vertically to the annular flow channel and has a distance from the intersection of the annular flow channel and any straight flow channel.

[0033] When the coolant in the upper cooling chamber enters the lower cooling chamber through the connecting hole 4-2-2, it first enters the annular flow channel, then flows along the annular flow channel to the straight flow channel, and then flows through the straight flow channel to the lower platform center hole 4-3-1, thus exiting the lower cooling chamber; or, the coolant entering the lower cooling chamber through the lower platform center hole 4-3-1 first splits into two straight flow channels, then flows into the annular flow channel, and flows along the annular flow channel to the position corresponding to the connecting hole 4-2-2 before entering the upper cooling chamber. In this way, the flow channel layout in the lower cooling chamber is relatively compact, achieving a certain degree of cooling and heat dissipation for the lower platform 4-3 and the middle platform 4-2, while the length of the flow channel is not very long, allowing the coolant to quickly flow out of the lower cooling chamber to be discharged to the external cooling system, or to quickly enter the upper cooling chamber from the lower cooling chamber.

[0034] In this embodiment, two straight grooves 4-3-3 extend in the same radial direction as the annular groove 4-3-2, making the two straight flow channels arranged at 180°. Thus, the intersections of the annular flow channel and each straight flow channel are evenly distributed in the same circumferential direction. Simultaneously, the distances from each connecting hole 4-2-2 to the two adjacent intersections are equal, meaning the line connecting the two connecting holes 4-2-2 intersects the two straight flow channels in a cross shape. This allows the coolant entering the annular flow channel from the upper cooling chamber to be diverted circumferentially to both sides. The coolant flows along equal-length paths on both sides to reach the straight flow channels, enabling rapid discharge of coolant from the lower cooling chamber. Alternatively, the coolant entering the lower cooling chamber from the lower platform center hole 4-3-1 is diverted by the two straight flow channels, and then further diverted upon reaching the annular flow channel. The diverted coolant flows along equal-length paths to reach the connecting hole 4-2-2, enabling rapid entry of coolant into the upper cooling chamber.

[0035] In other embodiments, depending on the number of spiral channels, for example, when there are three or more spiral channels, there are also three or more straight channels. The number of straight channels is equal to the number of spiral channels, and the straight channels are evenly distributed in a radiating pattern. That is, the intersections of the annular channels and the straight channels are evenly distributed in the same circumferential direction. The connecting holes are located between two adjacent intersections, ensuring that the distances to the two adjacent intersections are equal. In this case, the paths of the distributed coolant are also of equal length. Of course, in other embodiments, regardless of whether there are two or more spiral channels and three or more straight channels, the outer ends of each spiral channel may not be evenly distributed in the same circumferential direction, and the intersections of the annular channels and the straight channels may not be evenly distributed in the same circumferential direction. In this case, the distances to the connecting holes from the two adjacent intersections are not equal.

[0036] In other embodiments, both the annular groove and the linear groove can be disposed on the middle platform 4-2, located on the end face of the middle platform 4-2 facing the lower platform 4-3. In this case, the portion of the lower platform 4-3 facing the middle platform 4-2 is flat, thus forming an annular flow channel and a linear flow channel together with the annular groove and the linear groove on the middle platform 4-2. Of course, in other embodiments, annular grooves and linear grooves can also be disposed on the opposite end faces of the middle platform 4-2 and the lower platform 4-3, respectively, with the grooves on both sides communicating with each other to jointly form an annular flow channel and a linear flow channel.

[0037] Furthermore, such as Figure 7 As shown, in this embodiment, a central converging groove 4-3-4 communicating with the straight groove 4-3-3 is provided at the center of the lower platform 4-3, thereby forming a central converging cavity communicating with the straight flow channel between the middle platform 4-2 and the lower platform 4-3. This allows the coolant entering the lower cooling chamber from the upper cooling chamber to ultimately converge in the central converging cavity, facilitating coolant discharge; or, coolant entering the lower cooling chamber from the central hole 4-3-1 of the lower platform first diffuses into the central converging cavity and then flows to each straight flow channel, facilitating coolant distribution. In other embodiments, if the annular groove and the straight groove are only provided on the middle platform 4-2, the central converging groove is located at the center of the middle platform 4-2; or if the middle platform 4-2 and the lower platform 4-3 are respectively provided with an annular groove and a straight groove, then the center of the middle platform 4-2 and the lower platform 4-3 are also provided with a central converging groove. Of course, in other embodiments, the central converging groove 4-3-4 may not be provided, in which case there is no central converging cavity structure, and the straight flow channel directly communicates with the central hole 4-3-1 of the lower platform.

[0038] Furthermore, in this embodiment, the upper platform 4-1, the middle platform 4-2, and the lower platform 4-3 are positioned by positioning pins. This makes it easier to ensure the correct relative position of the three platforms when manufacturing the growth base, thereby ensuring the correct relative position of the spiral groove 4-1-1, the annular groove 4-3-2, the straight groove 4-3-3, and the connecting hole 4-2-2.

[0039] Specifically, the aforementioned positioning pins include two circumferentially distributed inner positioning pins installed between the middle platform 4-2 and the lower platform 4-3, and two circumferentially distributed outer positioning pins installed between the upper platform 4-1 and the lower platform 4-3. Correspondingly, combined with Figure 6 and Figure 7 As shown, the upper platform 4-1 has two upper outer positioning holes 4-1-2 for installing outer positioning pins, the middle platform 4-2 has two middle inner positioning holes 4-2-3 for installing inner positioning pins, and the lower platform 4-3 has two lower inner positioning holes 4-3-5 for installing inner positioning pins. Additionally, the lower platform 4-3 has two lower outer positioning holes 4-3-6 for installing outer positioning pins. The upper outer positioning holes 4-1-2, lower inner positioning holes 4-3-5, and lower outer positioning holes 4-3-6 are all blind holes, while the middle inner positioning hole 4-2-3 is a through hole. This ensures the integrity of the top surface of the upper platform 4-1 and the bottom surface of the lower platform 4-3, and prevents coolant leakage from the growth substrate.

[0040] By positioning the middle platform 4-2 and the lower platform 4-3, as well as the upper platform 4-1 and the lower platform 4-3, the relative positions of the three platforms are ensured to be correct, making it easier to avoid the spiral groove 4-1-1 when machining the positioning hole.

[0041] Furthermore, in this embodiment, the line connecting the two lower inner positioning holes 4-3-5 intersects the two straight grooves 4-3-3 in a cross shape, avoiding the straight grooves 4-3-3 to the greatest extent. At the same time, the middle inner positioning holes 4-2-3 are arranged one-to-one with each other on the radially inner side of the connecting hole 4-2-2. The two connecting holes 4-2-2, the two middle inner positioning holes 4-2-3, and the center hole 4-2-1 of the platform are located on the same straight line, which also serves as a clear indicator during assembly.

[0042] In other embodiments, the inner positioning hole 4-2-3, the connecting hole 4-2-2, and the center hole 4-2-1 of the platform may not be on the same straight line. That is, the inner positioning hole 4-2-3 is not radially inside the connecting hole 4-2-2. For example, there may be an angle between the line connecting the two inner positioning holes 4-2-3 and the line connecting the two connecting holes 4-2-2, such as 30° or 45°. Correspondingly, the line connecting the two lower inner positioning holes 4-3-5 is no longer perpendicular to the straight groove 4-3-3. In other embodiments, more than three inner and outer positioning pins may be provided respectively. Correspondingly, more than three upper outer positioning holes 4-1-2, lower inner positioning holes 4-3-5, lower outer positioning holes 4-3-6, and inner positioning holes 4-2-3 may be provided and evenly distributed around the circumference, as long as the spiral groove 4-1-1, the annular groove 4-3-2, and the straight groove 4-3-3 are avoided.

[0043] Furthermore, in this embodiment, the upper platform 4-1 and the lower platform 4-3 are fixedly connected near their outer circumference by multiple circumferentially distributed screws, with the middle platform 4-2 clamped between the upper platform 4-1 and the lower platform 4-3 for easy assembly and manufacturing. Correspondingly, both the upper platform 4-1 and the lower platform 4-3 are provided with screw mounting holes for installing the screws. The screw mounting hole on the upper platform 4-1 is a threaded blind hole 4-1-3, and the screw mounting hole on the lower platform 4-3 is a screw through hole 4-3-7. The upper outer positioning hole 4-1-2 and the threaded blind hole 4-1-3 are located on the same circumference and between two adjacent threaded blind holes 4-1-3. The lower outer positioning hole 4-3-6 and the screw through hole 4-3-7 are located on the same circumference and between two adjacent screw through holes 4-3-7, facilitating the machining and manufacturing of the positioning holes and the installation of the positioning pins.

[0044] In other embodiments, depending on the specific dimensions of the upper platform 4-1 and the lower platform 4-3, the lower outer positioning hole 4-3-6 and the screw through hole 4-3-7 may not be on the same circumference, but rather located inside or outside the circumference of the screw through hole 4-3-7, or even radially inside or outside a screw through hole 4-3-7. Similarly, the upper outer positioning hole 4-1-2 and the threaded blind hole 4-1-3 may also not be on the same circumference, but rather located inside or outside the circumference of the threaded blind hole 4-1-3, or even radially inside or outside a threaded blind hole 4-1-3. In other embodiments, when the positioning pin / positioning hole does not interfere with the spiral groove 4-1-1, the upper platform 4-1, the middle platform 4-2, and the lower platform 4-3 can be positioned using the same set of positioning pins, that is, each positioning pin simultaneously positions and engages with all three platforms, instead of indirectly achieving the positioning of the three platforms through a combination of two positioning pins. Of course, in other embodiments, positioning pins may not be used for positioning, and the placement position may be controlled manually or by machine during assembly.

[0045] Furthermore, combined Figure 4 , Figure 6 and Figure 7 As shown, in this embodiment, a second sealing ring 4-4 ​​is provided on the inner side of the screw connection position between the upper platform 4-1 and the lower platform 4-3 to ensure the sealing between the upper platform 4-1 and the lower platform 4-3 and prevent coolant leakage. Specifically, a mounting groove 4-1-4 for installing the second sealing ring 4-4 ​​is provided on the upper platform 4-1. The mounting groove 4-1-4 is located on the periphery of each spiral flow channel to ensure the sealing of the flow channel. In other embodiments, the mounting groove for installing the second sealing ring 4-4 ​​can also be provided on the lower platform 4-3. Of course, in other embodiments, if the upper platform 4-1, the middle platform 4-2, and the lower platform 4-3 are fixed by welding, the screws, screw mounting holes, the second sealing ring 4-4, and the mounting groove 4-1-4 can be omitted.

[0046] In this embodiment, the lower platform 4-3 is provided with a stepped groove 4-3-8, which is located on the upper outer side of the annular groove 4-3-2. The middle platform 4-2 is embedded in the stepped groove 4-3-8, so that the end faces of the upper platform 4-1, the middle platform 4-2, and the lower platform 4-3 are in contact, and the outer diameters of the upper platform 4-1 and the lower platform 4-3 are equal. In other embodiments, the stepped groove can also be provided on the upper platform 4-1, and the outer diameters of the upper platform 4-1 and the lower platform 4-3 are still equal. Of course, in other embodiments, multiple stepped grooves can also be provided on the upper platform 4-1, so that the middle platform 4-2 and the lower platform 4-3 are both embedded in the stepped grooves, and the bottom surface of the lower platform 4-3 is flush with the bottom surface of the upper platform 4-1; or multiple stepped grooves can be provided on the lower platform 4-3, so that the upper platform 4-1 and the middle platform 4-2 are both embedded in the stepped grooves, and the top surface of the upper platform 4-1 is flush with the top surface of the lower platform 4-3.

[0047] A downward-extending middle platform connector 4-6 is connected to the center hole 4-2-1 of the middle platform, and the middle platform connector 4-6 communicates with the upper cooling cavity; a downward-extending lower platform connector 4-7 is connected to the center hole 4-3-1 of the lower platform, and the lower platform connector 4-7 is nested outside the middle platform connector 4-6, and the annular space between the two communicates with the lower cooling cavity.

[0048] like Figure 4 As shown, the lower part of the lower stage pipe 4-7 and the middle stage pipe 4-6 are connected to the second water collector 12. A lifting drive device is connected below the second water collector 12 to control the vertical movement of the second water collector 12 and the growth substrate assembly 4, thereby changing the vertical height of the molybdenum stage 6 and the cooling effect of the water-cooled stage on the growth substrate. In this embodiment, the lifting drive device is a lifting motor 14; in other embodiments, it can also be a hydraulic cylinder or a pneumatic cylinder.

[0049] The second water collector 12 includes a second water collector body and a second plug 12-3 that is sealed and fixedly connected to the upper end of the second water collector body. The second water collector body includes a second upper block 12-1 and a second lower block 12-2. The second plug 12-3 is threaded to the upper end opening of the second upper block 12-1. A sixth sealing ring 12-6 is provided at the mating surface between the second plug 12-3 and the second upper block 12-1 to achieve a seal between the two.

[0050] The lower end of the lower connector 4-7 passes through the second plug 12-3 and extends into the second upper block 12-1. The second upper block 12-1 has a step, and the lower end of the lower connector 4-7 abuts against the step. A second nut cap 12-4 is threaded onto the top of the second plug 12-3, and the lower connector 4-7 passes through the second nut cap 12-4. A second sealing ring 12-5 is provided between the upper opening of the second plug 12-3 and the outer circumference of the lower connector 4-7. When the second nut cap 12-4 is tightened, it compresses the second sealing ring 12-5, achieving a seal between the second plug 12-3 and the lower connector 4-7, preventing liquid leakage from the second water collector 12. Simultaneously, the friction of the second sealing ring 12-5 creates a certain bonding force between the second water collector 12 and the lower connector 4-7.

[0051] A clamp 16 is fixedly connected to the second nut cover 12-4 for clamping and fixing it to the lower platform pipe 4-7 after the second nut cover 12-4 is installed. After the second nut cover 12-4 is tightened to achieve a seal between the second sealing ring 12-5 and the lower platform pipe 4-7, the rigid connection between the clamp 16 and the lower platform pipe 4-7 indirectly fixes the second water collector 12 to the lower platform pipe 4-7. Thus, when the lifting motor 14 drives the second water collector 12 to move up and down, the second water collector 12 can stably drive the lower platform pipe 4-7 to move up and down, preventing slippage of the connection position during the lifting process or water pressure fluctuations.

[0052] Below the second nut cap 12-4, a round flange 17 is fitted over the second plug 12-3. A clamp 16 is located above the second nut cap 12-4. The clamp 16 and the round flange 17 are fixedly connected by at least two fixing bolts 18 to clamp the second nut cap 12-4 between the clamp 16 and the round flange 17.

[0053] The clamp 16 comprises two separate clamping rings, which are fixedly connected by two locking bolts. During assembly, after the second nut cover 12-4 is installed, the fixing bolts 18 are first pre-tightened to give the two clamping rings and the round flange 17 an initial clamping force on the middle second nut cover 12-4, but not a complete clamping; otherwise, the positions of the two clamping rings will be fixed, and the lower platform pipe 4-7 cannot be clamped. Then, the locking bolts are installed on the two clamping rings. The gap between the fixing bolts 18 and the bolt holes on the clamping rings allows the two clamping rings to move relative to each other to clamp the outer circumference of the lower platform pipe 4-7. Of course, the fixing bolts 18 need to be tightened again during installation so that the clamp 16 clamps the lower platform pipe 4-7 while the clamp 16 and the round flange 17 also clamp the second nut cover 12-4. Alternatively, the locking bolts can be pre-tightened to give the two clamping rings an initial clamping force on the lower platform pipe 4-7, but not a complete clamping; then the fixing bolts 18 can be installed, and the locking bolts tightened simultaneously during installation.

[0054] Combination Figure 2 and Figure 4 As shown, a substrate 19 extending outwards is pressed between the bolt head of one of the fixing bolts 18 and the clamp 16. The growth stage assembly also includes a displacement sensor 15 and a mounting frame 10. A fixing ring 10-1 is provided on the mounting frame 10. The displacement sensor 15 is mounted on the fixing ring 10-1, and the measuring contact of the displacement sensor 15 presses against the substrate 19. Figure 2 (In the unassembled and unpressed state), when the growth platform moves up and down under the control of the lifting motor 14, the substrate 19 moves up and down accordingly, and the displacement sensor 15 can accurately record the values ​​of rising and falling.

[0055] like Figure 4 As shown, the lower end of the middle platform connector 4-6 extends through the lower platform connector 4-7, passes through the second upper block 12-1, and enters the second lower block 12-2. An inner sealing ring 12-8 is provided between the junction of the second upper block 12-1 and the second lower block 12-2 and the outer peripheral surface of the middle platform connector 4-6. Both the second upper block 12-1 and the second lower block 12-2 have flanges, which are fixedly connected by connecting bolts 12-11. When fixed, the end faces of the two blocks press against the inner sealing ring 12-8 to achieve a seal between the two blocks, as well as a seal between the middle platform connector 4-6 and the two blocks, preventing coolant in the second lower block 12-2 from entering the annulus between the middle platform connector 4-6 and the lower platform connector 4-7 through the gap between the middle platform connector 4-6 and the two blocks.

[0056] An outer sealing ring 12-7 is also provided between the end faces of the second upper block 12-1 and the second lower block 12-2. The outer sealing ring 12-7 is coaxially arranged outside the inner sealing ring 12-8, which enhances the sealing effect between the two blocks.

[0057] Furthermore, a second upper connector 12-10 is installed on the second upper block 12-1, communicating with the annular space between the middle platform connector 4-6 and the lower platform connector 4-7. A second lower connector 12-9 is installed on the second lower block 12-2, communicating with the middle platform connector 4-6. In this embodiment, the second lower connector 12-9 is a water inlet connector, and the second upper connector 12-10 is a water outlet connector, allowing the coolant to enter the middle platform connector 4-6 through the second lower connector 12-9, and then flow upward to the upper cooling chamber of the growth substrate. The coolant is distributed along each spiral flow channel, flowing from the center to the periphery, fully cooling the upper platform 4-1. Then, it enters the annular flow channel of the lower cooling chamber through the connecting hole 4-2-2 on the middle platform 4-2, and then flows along the annular flow channel into the straight flow channel, finally reaching the central converging chamber. It then flows downward through the annular space between the middle platform connector 4-6 and the lower platform connector 4-7 to the second water collector 12, and finally flows to the external cooling system through the second upper connector 12-10, thus achieving the cooling of the growth substrate. In other embodiments, the second lower connector 12-9 can also be a water outlet connector, in which case the second upper connector 12-10 is a water inlet connector.

[0058] The bottom surface of the second lower block 12-2 is provided with a bottom threaded hole, and the top output end of the lifting motor 14 is a screw, which is connected to the bottom threaded hole. At the same time, a side threaded hole 12-2-1 is provided on the side of the second lower block 12-2, which is perpendicular to the bottom threaded hole. A set screw is installed in the side threaded hole 12-2-1 to tighten the screw and prevent the connection between the lifting motor 14 and the second water collector block 12 from becoming loose.

[0059] The water-cooled stage in this embodiment is also an improved growth stage, such as... Figure 3 As shown, the water-cooled stage includes a copper disk 3-1, a water distribution plate 3-2, and an antenna disk 3-3. A sealing groove 3-4 is provided on the bottom surface of the copper disk 3-1 to achieve a seal with the quartz ring 5. The copper disk 3-1 also has an upward-facing upper groove and a downward-facing lower groove. The upper groove allows the growth substrate to sink into it, and a beryllium copper spiral tube 4-5 is installed on the outer periphery of the lower stage 4-3 of the growth substrate. Figure 4 As shown, the beryllium copper spiral tube 4-5 fits into the groove wall of the upper groove of the copper disk 3-1, serving to position and shield the microwaves. The upper groove of the copper disk 3-1 causes the growth stage to sink further relative to the surface of the water-cooled stage. This not only increases the possibility of matching the water-cooled stage surface with a higher or more varied molybdenum stage 6, but also results in a larger contact area between the sunken growth stage and the water-cooled stage, leading to better cooling.

[0060] The lower groove on the copper disk 3-1 is a stepped groove, and the water-dividing plate 3-2 is located in the stepped groove. The antenna disk 3-3 is fixed to the copper disk 3-1 by fastening screws 3-5, and the water-dividing plate 3-2 is pressed between the two. A first sealing ring 3-6 is provided between the antenna disk 3-3 and the copper disk 3-1 to achieve a seal between them.

[0061] The copper disk 3-1 is equivalent to the upper stage in the growth substrate, the water distribution plate 3-2 is equivalent to the middle stage in the growth substrate, and the antenna disk 3-3 is equivalent to the lower stage in the growth substrate. The water distribution plate 3-2 and the copper disk 3-1 form an upper cooling cavity, and the water distribution plate 3-2 and the antenna disk 3-3 form a lower cooling cavity. The water distribution plate 3-2 is provided with a connecting hole that connects the upper and lower cooling cavities. The flow channel design in the upper and lower cooling cavities is the same as that of the growth substrate, and will not be repeated here.

[0062] The bottom of the upper groove of the copper disk 3-1 has a through-hole, with a downward-extending copper disk connector 3-7 connected to the central hole. The connector 3-7 communicates with the upper groove. The center of the water distribution plate 3-2 has a central hole, with a downward-extending water distribution plate connector 3-8 connected to it. The connector 3-8 is nested outside the copper disk connector 3-7, forming an annular space between them, which communicates with the upper cooling cavity. The center of the antenna disk 3-3 has a central hole, with a downward-extending antenna rod 3-9 (i.e., the antenna disk connector) connected to it. The antenna rod 3-9 is nested outside the water distribution plate connector 3-8, also forming an annular space between them, which communicates with the lower cooling cavity.

[0063] The lower parts of the copper plate connector 3-7, the water distribution plate connector 3-8, and the antenna mast 3-9 are connected to a first water collector 11. The first water collector 11 includes a first water collector body and a first plug 11-3 that is sealed and fixedly connected to the lower end of the first water collector body. The first water collector body includes a first upper block 11-1 and a first lower block 11-2. The lower end of the antenna mast 3-9 extends into the first upper block 11-1 and is threadedly connected to the first upper block 11-1. A fifth sealing ring 11-8 is provided between the lower end face of the antenna mast 3-9 and the first upper block 11-1. After the two are tightened and fixed, the fifth sealing ring 11-8 is compressed to achieve a seal between the two.

[0064] The first upper block 11-1 and the first lower block 11-2 are connected by a threaded fit. The lower end of the water distribution plate pipe 3-8 extends through the antenna rod 3-9 and through the first upper block 11-1 into the first lower block 11-2. A fourth sealing ring 11-7 is provided between the junction of the first upper block 11-1 and the first lower block 11-2 and the outer circumference of the water distribution plate pipe 3-8. In this way, when the first upper block 11-1 and the first lower block 11-2 are tightened, both the two are fixedly connected and sealed. At the same time, the water distribution plate pipe 3-8 is sealed with the two blocks, preventing the annular space between the copper plate pipe 3-7 and the water distribution plate pipe 3-8 from communicating with the annular space between the water distribution plate pipe 3-8 and the antenna rod 3-9.

[0065] The first plug 11-3 is threaded to the lower end hole of the first lower block 11-2. A third sealing ring 11-6 is provided between the first plug 11-3 and the lower end face of the first lower block 11-2 to achieve a seal between the two.

[0066] The copper disc connector 3-7 extends out of the water distribution plate connector 3-8 and through the first plug 11-3. The lower part of the first plug 11-3 is threadedly connected to the first nut cap 11-4. The copper disc connector 3-7 passes through the first nut cap 11-4 and extends below the first nut cap 11-4. A first sealing ring 11-5 is provided between the lower end opening of the first plug 11-3 and the outer circumferential surface of the copper disc connector 3-7. When the first nut cap 11-4 is tightened, the first nut cap 11-4 compresses the first sealing ring 11-5, thereby achieving a seal between the first plug 11-3 and the copper disc connector 3-7, preventing liquid leakage from the annular space between the copper disc connector 3-7 and the water distribution plate connector 3-8.

[0067] In addition, a first lower connector 11-9 is installed on the first lower block 11-2, which is connected to the annular space between the copper plate pipe 3-7 and the water distribution plate pipe 3-8, and a first upper connector 11-10 is installed on the first upper block 11-1, which is connected to the annular space between the water distribution plate pipe 3-8 and the antenna mast 3-9. In this embodiment, the first lower connector 11-9 is a water inlet connector, and the first upper connector 11-10 is a water outlet connector. The coolant enters the annular space between the copper disk connector 3-7 and the water distribution plate connector 3-8 through the first lower connector 11-9, then flows upwards into the upper cooling chamber of the water-cooled platform. Through the flow distribution of the spiral channel, the coolant flows from the center to the periphery, effectively cooling the copper disk 3-1. Then, it enters the annular flow channel of the lower cooling chamber through the connecting hole on the water distribution plate 3-2, flows along the annular flow channel into the straight flow channel, and finally reaches the central converging chamber. It then flows downwards through the annular space between the water distribution plate connector 3-8 and the antenna mast 3-9 to the first water collector 11, and finally flows through the first upper connector 11-10 to the external cooling system, thus cooling the water-cooled platform. In other embodiments, the first lower connector 11-9 can also be a water outlet connector, in which case the first upper connector 11-10 is a water inlet connector.

[0068] like Figure 1 and Figure 2 As shown, the mounting frame 10 is fixed in position relative to the cavity 1, the first water collector 11 is fixed to the top of the mounting frame 10, and the lifting motor 14 is fixed to the bottom of the mounting frame 10. Furthermore, sealing devices 13 are provided at the lower end of the copper plate connecting pipe 3-7 and on the outside of the lower platform connecting pipe 4-7, such as... Figure 5 As shown, the sealing device 13 includes a telescopic cover 13-1 that covers the lower end of the copper disk connector 3-7 and the lower stage connector 4-7 and is retractable. The telescopic cover 13-1 is a bellows. The upper end of the telescopic cover 13-1 is provided with an upper connector that is sealed and fixed to the outer peripheral surface of the copper disk connector 3-7, and the lower end of the telescopic cover 13-1 is provided with a lower connector that is sealed and fixed to the outer peripheral surface of the lower stage connector 4-7, thereby sealing the gap between the lower stage connector 4-7 and the copper disk connector 3-7. Furthermore, when the lifting drive device controls the growth stage assembly 4 to move up and down, the telescopic cover 13-1 extends and retracts accordingly. Outside air can no longer enter the gap between the growth stage and the water-cooled stage through the gap between the lower stage connector 4-7 and the copper disk connector 3-7, ensuring the vacuum tightness of the sandwich formed by the inner circumference of the copper disk connector 3-7 and the outer circumference of the lower stage connector 4-7, thereby ensuring the vacuum tightness inside the MPCVD cavity during the lifting and lowering of the growth stage.

[0069] Specifically, the upper connector includes an upper collar 13-2 fixed to the upper end of the telescopic cover 13-1 and sleeved on the outside of the copper disc tube 3-7; an upper nut cap 13-3 sleeved on the outside of the copper disc tube 3-7 and threadedly connected to the upper part of the upper collar 13-2; and an upper sealing ring 13-4 located at the upper end opening of the upper collar 13-2 and pressed against the outer circumferential surface of the copper disc tube 3-7 by the upper nut cap 13-3. Through the tight contact between the upper sealing ring 13-4 and the outer circumferential surface of the copper disc tube 3-7, both sealing between the upper connector and the copper disc tube 3-7 are achieved, and a fixed connection between the upper connector and the copper disc tube 3-7 is achieved through static friction. This structure of the upper connector facilitates installation and facilitates sealing and fixing between the upper connector and the copper disc tube 3-7.

[0070] The lower connector includes a lower collar 13-5 fixed to the lower end of the telescopic cover 13-1 and sleeved on the outside of the lower platform pipe 4-7; a lower nut cap 13-6 sleeved on the outside of the lower platform pipe 4-7 and threaded to the lower part of the lower collar 13-5; and a lower sealing ring 13-7 located at the lower end opening of the lower collar 13-5 and pressed against the outer circumferential surface of the lower platform pipe 4-7 by the lower nut cap 13-6. The tight contact between the lower sealing ring 13-7 and the lower platform pipe 4-7 achieves both sealing between the lower connector and the lower platform pipe 4-7 and a fixed connection between the lower connector and the lower platform pipe 4-7 through static friction. This structure of the lower connector facilitates installation and enables sealing and fixation between the lower connector and the lower platform pipe 4-7.

[0071] In other embodiments, both the upper and lower connectors can be clamp structures, including two halves of a clamp ring. The two halves of the clamp ring clamp and fix the end of the telescopic cover 13-1 to the outer circumferential surface of the copper disc pipe 3-7 or the lower platform pipe 4-7, thus achieving both sealing and fixation. Of course, to improve the sealing effect, a sealing ring can also be added.

[0072] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. The patent protection scope of the present utility model shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present utility model shall also be included within the protection scope of the present utility model.

Claims

1. A growth stage for synthesizing diamond, the growth stage comprising an upper stage, a middle stage, and a lower stage fixed together, the middle stage forming an upper cooling chamber and a lower cooling chamber with the upper stage and the lower stage respectively, the middle stage having a connecting hole connecting the upper and lower cooling chambers, characterized in that, The upper platform and / or the middle platform are provided with at least two spiral grooves extending in a planar spiral shape from the center to the periphery to form at least two spiral flow channels between the upper platform and the middle platform. Each spiral flow channel together forms an upper cooling cavity. The center end of each spiral flow channel corresponds to and is connected to the center hole of the middle platform. A connecting hole is provided on the middle platform at a position corresponding to the periphery end of each spiral flow channel.

2. The growth stage for synthesizing diamond according to claim 1, characterized in that, in the middle The platform and / or the lower platform are provided with an annular groove and at least two straight grooves connecting the central hole of the lower platform and the annular groove, so as to form an annular flow channel and at least two straight flow channels between the middle platform and the lower platform. The annular flow channel and each straight flow channel together form a lower cooling cavity. Each connecting hole corresponds vertically to the annular flow channel and has a distance to the intersection of the annular flow channel and any straight flow channel.

3. The growth stage for synthesizing diamond according to claim 2, characterized in that, The outer ends of each spiral flow channel are evenly distributed in the same circumferential direction, the intersections of the annular flow channel and each straight flow channel are evenly distributed in the same circumferential direction, and the distances from each connecting hole to two adjacent intersections are equal.

4. The growth stage for synthesizing diamond according to claim 2, characterized in that, The middle platform and / or the lower platform are provided with a central converging groove communicating with the straight groove, so as to form a central converging cavity communicating with the straight flow channel between the middle platform and the lower platform.

5. The growth stage for synthesizing diamond according to any one of claims 1 to 4, characterized in that, The upper, middle, and lower stages are positioned using positioning pins.

6. The growth stage for synthesizing diamond according to claim 5, characterized in that, The positioning pins include at least two circumferentially distributed inner positioning pins installed between the middle platform and the lower platform, and at least two circumferentially distributed outer positioning pins installed between the upper platform and the lower platform.

7. The growth stage for synthesizing diamond according to claim 6, characterized in that, The platform is provided with inner positioning holes for installing each inner positioning pin. The inner positioning holes are arranged one-to-one on the radial inner side of the connecting hole.

8. The growth stage for synthesizing diamond according to claim 6, characterized in that, The upper and lower platforms are fixedly connected near the outer circle by multiple circumferentially distributed screws. Both the upper and lower platforms are provided with screw mounting holes for installing the screws and external positioning holes for installing each external positioning pin. The external positioning holes are located between two adjacent screw mounting holes.

9. The growth stage for synthesizing diamond according to any one of claims 1 to 4, characterized in that, The upper and lower platforms are fixedly connected near the outer circle by multiple circumferentially distributed screws. A sealing ring is provided on the inner side of the screw connection position between the upper and lower platforms. The upper or lower platform is provided with a mounting groove for installing the sealing ring, and the mounting groove is located on the periphery of each spiral flow channel.

10. The growth stage for synthesizing diamond according to any one of claims 2 to 4, characterized in that, Both the annular groove and the straight groove are located on the lower platform, while the spiral groove is located on the upper platform. The middle platform is a flat plate structure, and the upper or lower platform has a stepped groove for the middle platform to be embedded in.

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