An evaporation device

Abstract

The application relates to an evaporation device, which comprises a main body and a cover body composed of an outer cover, a middle cover and an inner cover arranged in sequence; a crucible and a heating mechanism are arranged in the main body; first and second flow spaces are formed between the inner cover and the middle cover and between the middle cover and the outer cover; an evaporation hole of the inner cover and a communication port of the middle cover are arranged in an axial dislocation mode, and a non-straight-viewing zigzag exhaust path is constructed. The evaporation device physically intercepts splashing liquid drops by means of the dislocation structure, prevents the splashing liquid drops from escaping and damaging the smoothness of a film layer, simultaneously buffers and mixes air flow by means of multi-stage flow spaces, and makes the exhaust air flow more stable and uniform, so that the film quality defects caused by the splashing liquid drops and uneven air flow distribution are effectively solved, and the uniformity of film coating and the film forming quality are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of vacuum coating technology, and more particularly to an evaporation apparatus. Background Technology

[0002] Vacuum evaporation coating technology is widely used in the manufacturing industries of semiconductors, optoelectronic devices, display panels and precision optical instruments. Its basic principle is to heat the material to be coated to vaporization using an evaporation source in a high vacuum environment, so that the evaporated particles are deposited on the substrate surface to form a thin film.

[0003] In existing vacuum coating processes, the evaporation source is the core component determining the coating quality. Currently, conventional evaporation methods mainly include resistance heating evaporation and electron beam evaporation. Among these, resistance heating using a tungsten-molybdenum boat is a common method. This involves using a high-melting-point metal (such as tungsten or molybdenum) to form a boat shape, directly applying electricity to generate Joule heat to melt and evaporate the material inside the boat. Another common method uses a ceramic crucible to hold the material to be evaporated, and an electron gun emits an electron beam to directly bombard the material surface for heating and evaporation.

[0004] However, the aforementioned existing technologies have many drawbacks in practical applications. First, evaporation is unstable. Traditional direct heating elements (such as metal boats) are prone to thermal deformation during repeated high-temperature thermal cycles, leading to changes in the geometry of the evaporation source and thus affecting the stability of the evaporation rate. Most critically, existing evaporation structures often result in surface quality defects in the thin film. During material melting or evaporation, droplet splashing points are easily generated, directly bombarding the substrate. Furthermore, the distribution of the evaporation gas flow is often uneven, resulting in poor uniformity of the deposited film and severely affecting its smoothness. Therefore, a novel evaporation device is urgently needed to solve these problems. Summary of the Invention

[0005] The purpose of this invention is to provide an evaporation device with a stable structure that can effectively intercept splashes and optimize airflow distribution.

[0006] The technical solution adopted by the present invention to solve the above problems is: an evaporation device, comprising:

[0007] The main body includes:

[0008] The outer casing includes a first receiving space and a first opening communicating with the first receiving space;

[0009] A crucible disposed within the first accommodating space, the crucible including a second accommodating space for accommodating the material to be evaporated, the second accommodating space extending along the axial direction of the crucible to the surface of the crucible to form a second opening, the second opening communicating with the first opening;

[0010] A heat insulation layer is disposed between the outer shell and the crucible;

[0011] A heating mechanism, at least partially disposed in the first accommodating space and located between the insulation layer and the crucible, is used to heat the crucible;

[0012] The lid includes an outer lid, a middle lid, and an inner lid arranged sequentially from the outside to the inside; the outer lid has a discharge port; the middle lid has a connecting port corresponding to the discharge port, and a second flow space for evaporation gas flow is formed between the middle lid and the outer lid; the inner lid has an evaporation hole, and a first flow space for evaporation gas flow is formed between the inner lid and the middle lid; the projection of the evaporation hole on the axial direction of the crucible is offset from the projection of the connecting port on the axial direction of the crucible.

[0013] When the evaporation device is in operation, the vaporization gas generated by the vaporization of the material to be evaporated in the crucible passes sequentially through the evaporation hole, the first flow space, the connecting port and the second flow space, and is discharged from the evaporation device from the discharge port.

[0014] Preferably, the first opening of the outer shell is provided with an annular overlapping member, and the crucible is mounted on the outer shell through the annular overlapping member, so that the outer wall of the crucible and the inner wall of the insulation layer are kept apart; both the outer shell and the insulation layer are provided with a first through hole for the heating mechanism to pass through, and an insulating member is provided in the first through hole, and the heating mechanism passes through the insulating member at least partially and extends to the outside of the main body.

[0015] Preferably, the evaporation apparatus further includes a floating vortex mechanism, the floating vortex mechanism comprising:

[0016] A valve seat is disposed on the middle cover and located at the communication port. The valve seat has a valve body space in the shape of a frustum or a cone. A first valve port communicating with the first flow space is opened on the side of the valve body space near the inner cover. A second valve port communicating with the second flow space is opened on the side of the valve body space near the outer cover. The diameter of the second valve port is larger than the diameter of the first valve port.

[0017] The valve core is in the shape of a frustum or a cone that matches the shape of the valve body space. The valve core is at least partially movable within the valve body space. The outer wall of the valve core is provided with a plurality of spiral guide grooves evenly distributed in the circumferential direction. The spiral guide grooves extend along the axial direction of the valve core, and the extension direction of the spiral guide grooves extends from the end of the valve core near the inner cover to the end of the valve core away from the inner cover.

[0018] Specifically, when the pressure of the evaporating gas flow in the first flow space is less than the first preset pressure value, the valve core blocks the valve body space under the action of gravity; when the pressure of the evaporating gas flow is greater than the first preset pressure value, the valve core is lifted by the evaporating gas flow and rotates using the spiral guide groove, and the evaporating gas flow enters the second flow space through the gap between the valve core and the inner wall of the valve body space.

[0019] Preferably, an annular raceway is formed on the end face of the valve core away from the inner cover, and the center of the annular raceway is collinear with the central axis of the valve core;

[0020] The evaporation device further includes a plurality of guide components disposed between the outer cover and the middle cover, the guide components being distributed at circumferential intervals along the annular raceway; each guide component includes:

[0021] A fixing tube, one end of which is connected to the outer cover and the other end of which is positioned toward the middle cover;

[0022] A counterweight rod is movably inserted into the fixed tube and at least partially protrudes and extends beyond the end of the fixed tube facing the middle cover.

[0023] A limiting member is provided at one end of the counterweight rod extending outside the fixed tube. A spherical groove is provided in the limiting member, and an opening communicating with the spherical groove is provided on the side of the limiting member near the annular raceway.

[0024] A ball bearing is disposed within the spherical groove, and the ball bearing is at least partially exposed through the opening in the spherical groove and rolls against the annular raceway.

[0025] When the evaporation device is in operation, the counterweight rod uses its own weight to apply a downward resisting force to the annular raceway through the ball bearings.

[0026] Preferably, the evaporation apparatus further includes a heat-conducting element, the heat-conducting element comprising:

[0027] A heating element is disposed within the first flow space and surrounding the bottom of the valve seat or surrounding the communication opening of the middle cover;

[0028] A heat transfer section, one end of which is connected to the heating section, and the other end of which extends into the first accommodating space and is disposed near the outer wall of the crucible.

[0029] Preferably, the heating element is an annular structure coaxially arranged with the communication port.

[0030] Preferably, the evaporation apparatus further includes a differential separation mechanism, the differential separation mechanism comprising:

[0031] A spacer ring is provided at the top of the inner cover;

[0032] A push rod is provided on the top of the inner cover, one end of which is fixed to the inner cover, and the other end extends to the first valve port and is directly opposite the bottom of the valve core; the coefficient of thermal expansion of the push rod is less than that of the spacer ring.

[0033] At a first preset temperature, the end of the push rod away from the inner cover abuts against the end of the valve core near the inner cover, raising the valve core relative to the valve seat to a first target height, thereby forming an exhaust gap between the side of the valve core and the inner wall of the valve body space. At a second preset temperature higher than the first preset temperature, after the spacer ring expands due to heat, the end of the spacer ring away from the inner cover abuts against the side of the middle cover near the inner cover, raising the middle cover to a second target height, so that the inner wall of the valve body space fits against the side of the valve core, and the second target height is greater than the first target height.

[0034] Preferably, a movable gap is provided between the side of the middle cover away from the inner cover and the side of the outer cover close to the middle cover, the movable gap being at least equal to the second target height; a counterweight is provided within the movable gap, the counterweight being disposed on the side of the middle cover away from the inner cover, and applying pressure to the middle cover in the direction of the inner cover using its own weight.

[0035] Preferably, the bottom center of the middle cover is provided with a protrusion extending toward the inner cover, and the center of the protrusion is provided with a groove for inserting the top rod; the spacer ring is sleeved on the outer periphery of the protrusion, and the inner diameter of the spacer ring is greater than the outer diameter of the protrusion at the first preset temperature, so as to allow the spacer ring and the middle cover to undergo relative thermal expansion displacement.

[0036] Preferably, the spacer ring is made of alumina ceramic material, and the push rod is made of tungsten or carbon composite material; the valve core is frustum-shaped, the end face of the valve core near the inner cover is an abutting plane, and the top end of the push rod abuts against the abutting plane at the first preset temperature.

[0037] The beneficial effects of the embodiments of the present invention are as follows:

[0038] 1. Due to the adoption of a cover structure consisting of an outer cover, a middle cover, and an inner cover arranged in sequence, and by utilizing the first flow space formed between the inner cover and the middle cover, and the second flow space formed between the middle cover and the outer cover, and by misaligning the projection of the evaporation hole on the inner cover onto the crucible axis with the projection of the connecting port on the middle cover onto the same axis, a non-direct-view tortuous exhaust path is constructed. Therefore, the problem of film surface quality defects caused by the direct bombardment of the substrate by molten droplets and uneven distribution of evaporation gas flow in the prior art is effectively solved. This achieves the physical interception and blocking of splashed droplets by the misaligned structure, preventing them from escaping through the outlet and damaging the film surface finish. At the same time, the multi-stage flow space is used to fully buffer and mix the evaporation gas flow, making the discharged gas flow more stable and uniform, significantly improving the uniformity of the coating and the film quality.

[0039] 2. Due to the adoption of a floating vortex mechanism, which includes a matching frustum-shaped or conical valve seat and a valve core with a spiral guide groove on the outer wall, and is supplemented by a guide assembly containing a counterweight rod and balls located between the outer cover and the middle cover, and an annular raceway on the top of the valve core, the problem of droplet splashing caused by the rupture of internal bubbles or uneven heating in the early stage of material melting, which damages the surface smoothness of the film, is effectively solved in the prior art. This allows the valve core to automatically seal the valve body space to physically isolate splashing droplets in the early stage of low-pressure melting by using the gravity of the valve core. After the evaporation pressure increases, the spiral guide groove converts the straight airflow into a vortex to drive the valve core to spin. Centrifugal force is used to remove adhering impurities and homogenize the evaporation airflow. At the same time, the guide assembly uses the cooperation of the balls and the raceway to convert sliding friction into rolling friction, which limits the vertical jump of the valve core and prevents its rotational deviation, ensuring the dynamic stability of the valve core in the pneumatic suspension state, and significantly improving the surface quality and uniformity of the coating.

[0040] 3. Due to the use of heat-conducting components, the heat extended to the first accommodating space and close to the outer wall of the crucible is conducted to the annular heating part located in the first flow space and surrounding the bottom of the valve seat or the connecting port. Therefore, it effectively solves the technical problem in the prior art that the temperature of the cover plate of a traditional covered crucible is usually lower than that of the bottom of the crucible, which causes steam to condense at the outlet, gradually block the channel, and change the evaporation distribution. In this way, the heat of the heating area is directionally transported to the steam outlet area through the thermal bridge effect, which compensates for the heat loss at the cover and forces the temperature at the valve seat and the connecting port to be maintained at a high level (such as above the melting point of the material). This physically eliminates the conditions for steam condensation and scaling, and ensures the long-term unobstructed flow of the evaporation channel and the stability of the evaporation airflow distribution.

[0041] 4. By employing a differential separation mechanism that includes spacers and push rods with different coefficients of thermal expansion (the push rod coefficient is smaller than that of the spacer), and supplemented by the movement gap and counterweight, the relative displacement control of the valve core and valve seat is achieved by utilizing the difference in axial dimensional changes of the spacer and push rod under temperature changes. Therefore, it effectively solves the technical problem of mechanical jamming (cold welding) of the valve core and valve seat caused by the solidification of residual metal vapor and surface diffusion welding during the cooling process after evaporation when using a precision anti-splash valve structure in the prior art. Furthermore, it realizes that during the cooling process, by utilizing the physical characteristic that the shrinkage of the spacer is greater than that of the push rod, the middle cover (valve seat) descends relative to the push rod. This uses the huge thermal stress difference to force the push rod to lift the valve core, physically shearing or destroying the metal adhesion layer that may form between the valve core and valve seat. While preventing the equipment from locking up, it automatically resets the device to a normal temperature standby state with an exhaust gap, ensuring the reusability of the evaporation source. Attached Figure Description

[0042] Figure 1 A schematic cross-sectional view of an evaporation apparatus according to an embodiment of this application is shown.

[0043] Figure 2 A schematic exploded view of an evaporation apparatus according to an embodiment of this application is shown.

[0044] Figure 3 An exploded cross-sectional view of an evaporation apparatus according to an embodiment of this application is shown.

[0045] Figure 4 A schematic exploded view of a cover according to an embodiment of this application is shown.

[0046] Figure 5 A schematic exploded cross-sectional view of a cover according to an embodiment of this application is shown.

[0047] Figure 6 A schematic structural diagram of a valve core according to an embodiment of this application is shown.

[0048] Figure 7 A schematic exploded view of a guide assembly according to an embodiment of this application is shown.

[0049] Figure 8 A schematic structural diagram of an evaporation apparatus according to an embodiment of this application is shown.

[0050] The components are as follows: 1. Main body; 110. Outer shell; 120. Insulation layer; 130. Crucible; 2. Cover; 210. Outer cover; 211. Discharge port; 220. Middle cover; 221. Connecting port; 230. Inner cover; 231. Evaporation hole; 232. Protrusion; 2321. Groove; 240. Counterweight; 3. Insulating component; 4. Heating mechanism; 5. Annular overlapping component; 6. Guide assembly; 610. Fixing tube; 620. Counterweight rod; 630. Limiting component; 640. Ball bearing; 7. Floating vortex mechanism; 710. Valve seat; 711. Valve body space; 720. Valve core; 721. Spiral guide groove; 722. Annular raceway; 8. Differential separation mechanism; 810. Spacer ring; 820. Top rod; 9. Heat-conducting component; 910. Heating section; 920. Heat transfer section. Detailed Implementation

[0051] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0052] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0053] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0054] Existing vacuum coating processes suffer from unstable evaporation sources. Traditional direct heating elements (such as metal boats) are prone to thermal deformation during repeated high-temperature thermal cycling, altering the geometry of the evaporation source and affecting the stability of the evaporation rate. Furthermore, existing evaporation structures are prone to generating droplet splashes during material melting or evaporation, directly bombarding the substrate. The distribution of the evaporation gas flow is often uneven, resulting in poor uniformity of the deposited film, severely impacting its smoothness and easily leading to quality defects on the film surface.

[0055] To address the aforementioned problems, a preferred embodiment of this application provides an evaporation apparatus. This embodiment provides a physical vapor deposition evaporation apparatus that can significantly improve the quality of film deposition, and is particularly suitable for preparing thin films of high-purity semiconductor or metallic materials such as germanium, silicon, aluminum, copper, gold, silver, and tellurium. The apparatus mainly consists of three parts: a main body 1, a heating mechanism 4, and a cover 2. These parts, through a compact and ingenious structural arrangement, together construct an evaporation source that is splash-proof and has a uniform flow field. Please refer to [link / reference] for details. Figures 1 to 8 .

[0056] The main body 1 includes an outer shell 110, a crucible 130, and a heat insulation layer 120. The outer shell 110 includes a first accommodating space and a first opening communicating with the first accommodating space. The crucible 130 is disposed within the first accommodating space and includes a second accommodating space for accommodating the material to be evaporated. The second accommodating space extends axially along the surface of the crucible 130 to form a second opening, which communicates with the first opening. The heat insulation layer 120 is disposed between the outer shell 110 and the crucible 130. A heating mechanism 4 is at least partially disposed in the first accommodating space and located between the heat insulation layer 120 and the crucible 130, for heating the crucible 130. The cover 2 includes an outer cover 210, a middle cover 220, and an inner cover 230 arranged sequentially from the outside to the inside. The outer cover... The outer cover 210 has a discharge port 211; the middle cover 220 has a connecting port 221 corresponding to the discharge port 211, and a second flow space for evaporation gas flow is formed between the middle cover 220 and the outer cover 210; the inner cover 230 has an evaporation hole 231, and a first flow space for evaporation gas flow is formed between the inner cover 230 and the middle cover 220; the projection of the evaporation hole 231 on the axial direction of the crucible 130 and the projection of the connecting port 221 on the axial direction of the crucible 130 are misaligned; wherein, when the evaporation device is in working condition, the evaporation gas flow generated by the vaporization of the material to be evaporated in the crucible 130 passes sequentially through the evaporation hole 231, the first flow space, the connecting port 221 and the second flow space, and is discharged from the evaporation device from the discharge port 211.

[0057] Specifically:

[0058] The main body 1 is the base of the evaporation device, which mainly includes the outer shell 110, the insulation layer 120 and the crucible 130.

[0059] The outermost protective structure of the device, housing 110, defines the first accommodating space. In this embodiment, housing 110 preferably adopts a rigid graphite structure, and its bottom and sidewalls are coated with an alumina heat-resistant insulating layer to enhance heat resistance and insulation. A first opening is provided at the top of housing 110, which serves as a channel for installing internal components and for the outward output of evaporative gas flow. Furthermore, to achieve precise temperature control, a mounting hole for installing a high-temperature thermocouple may be provided at the center of the bottom of housing 110.

[0060] The crucible 130 is disposed inside the first accommodating space of the outer shell 110, and it is the core container that directly holds the material to be evaporated. The interior of the crucible 130 defines a second accommodating space, and the crucible 130 extends upward along the axial direction (i.e., the height direction) until its surface forms a second opening, which communicates with the first opening of the outer shell 110.

[0061] Depending on the chemical properties of the material to be evaporated, the crucible 130 can be made of a ceramic material with good chemical stability, such as aluminum nitride, aluminum oxide, or boron nitride; or a graphite substrate combined with a coating (such as thermally sprayed aluminum oxide, yttrium oxide, aluminum nitride, or chromium nitride coating) can be used to prevent the crucible 130 from reacting with the material to be evaporated at high temperatures.

[0062] Furthermore, to address the issue of thermal expansion mismatch, expansion gaps are provided between the crucible 130, the outer shell 110, and the insulation layer 120. Simultaneously, the bottom of the crucible 130 does not directly contact the outer shell 110, but is placed on an insulating ring 810 (not shown in the figure) made of boron nitride, serving a dual function of support and insulation.

[0063] An insulation layer 120 is filled or disposed between the inner wall of the outer shell 110 and the outer wall of the crucible 130. In this embodiment, the insulation layer 120 is preferably made of alumina fiber felt. The insulation layer 120 plays a crucial role; on the one hand, it reduces heat transfer to the outer shell 110, protecting it from damage due to excessive heat, and also reduces the heat radiation from the outer shell 110 to the vacuum chamber; on the other hand, it locks heat around the crucible 130, improving thermal efficiency and ensuring a uniform temperature distribution within the crucible 130. The bottom of the insulation layer 120 also has through holes for thermocouples to pass through.

[0064] The heating mechanism 4 is disposed within the first accommodating space and located between the insulation layer 120 and the crucible 130. In this embodiment, tungsten stranded wire is preferably used as the resistance heating element of the heating mechanism 4, and the crucible 130 is radiantly heated by the Joule heat generated by the current.

[0065] To prevent short circuits, a boron nitride insulating layer is wrapped around the inlet and outlet positions where the tungsten stranded wire passes through the insulation layer 120 and the outer shell 110 to isolate the graphite outer shell 110, and annular boron nitride isolation rings are provided at the inlet and outlet positions.

[0066] In some other embodiments, the heating mechanism 4 may also employ induction heating (such as a water-cooled copper coil) or microwave heating.

[0067] The cover 2 is the core improvement of this embodiment, and it is placed over the opening of the main body 1. Unlike the traditional single-layer cover, the cover 2 of this embodiment adopts a three-layer structure stacked from the outside to the inside: outer cover 210, middle cover 220 and inner cover 230, which together form a splash-proof labyrinth structure.

[0068] The inner cover 230 is the first layer structure closest to the crucible 130. The inner cover 230 is placed over the opening of the crucible 130 and is preferably made of graphite. The inner cover 230 has a plurality of evaporation holes 231. In this embodiment, the evaporation holes 231 are specifically opened in the edge area of ​​the inner cover 230.

[0069] The middle cover 220 is the second layer structure, located between the inner cover 230 and the outer cover 210, and is preferably made of graphite. A connecting opening 221 is provided on the middle cover 220; in this embodiment, the connecting opening 221 is located at the center. A certain gap is maintained between the middle cover 220 and the inner cover 230 below, thus forming an independent first flow space.

[0070] The outer cover 210 is the third layer structure, located on the outermost layer, and is furthest from the crucible 130. The final discharge port 211 (i.e., the central hole) is opened on it.

[0071] The outer cover 210 adopts a composite structure, with an outer layer of rigid graphite and an inner layer of thin molybdenum sheet. The high reflectivity of the molybdenum sheet can effectively reflect heat and prevent evaporating substances from condensing and clogging between the cover body 2.

[0072] Connection method: Considering that the internal vapor pressure is higher than the external pressure during evaporation, the outer cover 210 is connected to the outer shell 110 by threads to ensure pressure resistance and safety.

[0073] Flow space: There is also a gap between the outer cover 210 and the middle cover 220 below, forming a "second flow space".

[0074] The most critical structural feature of this embodiment lies in the non-direct-view design of the flow channel. Specifically, the projection of the edge evaporation hole 231 on the inner cover 230 onto the axial direction of the crucible 130 is misaligned with the projection of the central connecting port 221 on the middle cover 220 onto the same axial direction. This means that if viewed from the outside through the discharge port 211, the line of sight will be blocked by the solid portion of the middle cover 220 or the inner cover 230, making it impossible to directly see the surface of the molten liquid inside the crucible 130. This misaligned design ensures that the solid portion of the inner cover 230 is directly opposite the connecting port 221 of the middle cover 220, or the solid portion of the middle cover 220 is directly opposite the evaporation hole 231 of the inner cover 230.

[0075] The operation of this evaporation device is a combination of thermodynamic evaporation and fluid dynamic rectification.

[0076] The device is mounted on the resistance evaporation source of the coating machine, and the electrodes are clamped by copper busbars. To reduce the deformation of the tungsten wire under stress, a buffer structure (such as a graphite sheet or zirconium oxide sheet in combination with alumina felt) is provided at the bottom of the device.

[0077] The current is gradually increased, and the temperature is monitored by the bottom thermocouple. The heating mechanism 4 operates, melting and vaporizing the material to be evaporated in the crucible 130, generating a high-temperature evaporation gas flow with a certain pressure. In the early stage of material melting or when the heating power fluctuates, the surface of the melt may burst, producing droplet splashes.

[0078] The evaporating airflow, carrying potential splash droplets, enters the first flow space through the evaporation holes 231 at the edge of the inner cover 230. Because the edge evaporation holes 231 are misaligned with the central connecting port 221 above, the high-speed jetting droplets (with greater momentum, making them difficult to change direction abruptly with the airflow) directly impact the lower surface of the middle cover 220 and are intercepted. Meanwhile, the gaseous evaporating molecules diffuse, collide, and mix within the first flow space, then bypass the obstacles and flow towards the central connecting port 221. During this process, the airflow not only filters out large droplets but also undergoes its first homogenization.

[0079] The pre-homogenized airflow passes through the central connecting port 221 of the middle cover 220 and enters the second flow space. Here, due to the heat reflection effect of the inner molybdenum sheet of the outer cover 210, the ambient temperature is maintained, preventing vapor condensation. The airflow expands and mixes again here, further eliminating airflow pulsation and density differences. Ultimately, this forms a very smooth, homogeneous, and droplet-free pure evaporation airflow, which exits from the outlet 211 of the outer cover 210 and is directed towards the substrate for deposition.

[0080] The evaporation apparatus of this embodiment is suitable for physical vapor deposition processes under high vacuum conditions. It is applicable to the evaporation of various metals (such as gold, silver, and aluminum) or non-metallic materials that require high film quality. It is particularly suitable for materials that are prone to sputtering during melting, as well as for precision optical coating or semiconductor manufacturing scenarios with strict requirements for film thickness uniformity and surface finish.

[0081] In this embodiment, the present invention employs a cover body 2 structure consisting of an outer cover 210, a middle cover 220, and an inner cover 230 stacked sequentially, and constructs a first flow space and a second flow space between the layers. Simultaneously, it creatively misaligns the evaporation holes 231 on the inner cover 230 with the connecting port 221 on the middle cover 220 in the axial direction, creating a non-direct-viewing labyrinthine tortuous exhaust path. Therefore, it effectively solves the technical problems in the prior art where the traditional straight-through structure causes molten droplets to easily splash and directly bombard the substrate, resulting in film defects, and where the evaporating gas flow is directly ejected without buffering, leading to poor film uniformity. Furthermore, it achieves the physical interception and blocking of splashing high-kinetic-energy droplets using a misaligned solid structure, preventing them from escaping through the outlet 211. At the same time, the multi-stage flow space forces the evaporating gas flow to undergo multiple expansions, buffering, and mixing, eliminating turbulence and pulsation of the gas flow, making the discharged gas flow more stable and the density distribution more uniform, significantly improving the surface smoothness and thickness uniformity of the final deposited film.

[0082] Please see Figures 2 to 5 In some embodiments, because the crucible 130 and the outer shell 110 have different coefficients of thermal expansion, an annular overlapping member 5 is provided at the first opening of the outer shell 110 to accommodate the different coefficients of thermal expansion. The crucible 130 is mounted on the outer shell 110 through the annular overlapping member 5, so that the outer wall of the crucible 130 and the inner wall of the insulation layer 120 are kept apart. Both the outer shell 110 and the insulation layer 120 have a first through hole for the heating mechanism 4 to pass through. An insulating member 3 is provided in the first through hole, and the heating mechanism 4 passes through the insulating member 3 at least partially and extends to the outside of the main body 1.

[0083] In this embodiment, a thermal adaptation and electrical insulation structure was specially designed to address the differences in thermal expansion behavior between different components of the evaporation device under high-temperature operating conditions.

[0084] To address the potential stress damage caused by the difference in thermal expansion coefficients between the crucible 130 (typically ceramic) and the outer shell 110 (typically graphite), an annular overlapping member 5 is provided at the first opening of the outer shell 110 (i.e., at the top edge of the outer shell 110). This annular overlapping member 5 is a high-temperature resistant insulating ring with a certain thickness and load-bearing capacity, and its shape matches the opening shape of the outer shell 110. The crucible 130 is not directly and rigidly fixed inside the outer shell 110, but rather overlaps the upper surface of the annular overlapping member 5 through its top edge structure, thereby achieving a framed or suspended installation. This framed installation method, combined with the size design of the annular overlapping member 5, ensures that the outer wall of the crucible 130 and the inner wall of the insulation layer 120 are not tightly fitted, but always maintain a gap of a predetermined width (i.e., an expansion buffer gap). This gap exists during cold assembly, and its width is calculated to accommodate the maximum radial thermal expansion of the crucible 130 at its highest operating temperature.

[0085] To allow external power to be introduced into the housing to drive the heating mechanism 4, first through holes are provided on the side walls or bottom of the outer casing 110 and at the corresponding insulation layer 120 locations for the heating mechanism 4 (such as electrode rods or heating wire leads) to pass through. To prevent short circuits between the conductive heating mechanism 4 and the potentially conductive outer casing 110 (such as graphite casing 110), an insulating element 3 is tightly embedded in the first through hole. This insulating element 3 is preferably a tubular or sleeve-shaped ceramic insulator with an inner diameter slightly larger than the diameter of the heating mechanism 4 and an outer diameter that matches the first through hole. The conductive portion of the heating mechanism 4 passes at least partially through the hollow tube of the insulating element 3 and extends to the outside of the main body 1 to connect to the power source.

[0086] During the startup and heating process of the device, both the crucible 130 and the outer shell 110 will expand in volume as the temperature rises rapidly. Since the coefficients of thermal expansion of the materials of the crucible 130 (such as alumina or boron nitride) and the outer shell 110 (such as graphite) are often different (typically, the expansion rate of the crucible 130 may be greater or less than that of the outer shell 110), the dimensional changes in the radial and axial directions will differ. At this time, the radial expansion of the crucible 130, supported by the annular overlapping member 5, will be directly released through the gap between its outer wall and the inner wall of the insulation layer 120, thereby preventing the crucible 130 from compressing the insulation layer 120 or the outer shell 110 due to thermal expansion, and preventing the resulting mechanical stress from causing the crucible 130 to crack or the outer shell 110 to deform. Simultaneously, the annular overlapping member 5, acting as an intermediate medium, allows a small amount of relative sliding between the crucible 130 and the outer shell 110 on the contact surface, further releasing thermal stress. In terms of electrical aspects, the insulating component 3 always physically isolates the energized heating mechanism 4 from the outer casing 110, ensuring that even under high temperature and high pressure conditions, the current only flows in the heating circuit, eliminating the safety hazard of the outer casing 110 being energized.

[0087] The structure of this embodiment is particularly suitable for vacuum coating environments with high temperatures (e.g., above 1000 degrees Celsius) and extremely high requirements for thermal stability. It is suitable for scenarios where the thermal properties of the crucible 130 and the support (shell 110) materials differ significantly. Simultaneously, this structure requires a stable installation environment to ensure that the crucible 130, mounted on the annular connecting member 5, naturally settles and remains centered under gravity.

[0088] In optional embodiments, the annular overlap member 5 may be made of boron nitride, zirconium oxide, or high-purity alumina ceramic, utilizing its excellent high-temperature insulation and compressive strength. The insulating member 3 may be a one-piece long ceramic tube penetrating the outer shell 110 and the insulation layer 120; or it may be a separate combined structure, respectively embedded in the insulation layer 120 and the outer shell 110. The width of this gap can be adjusted according to the specific crucible 130 size and operating temperature, for example, a larger gap can be reserved in large evaporation sources.

[0089] In this embodiment, by employing the technical means of setting an annular overlapping member 5 at the opening of the shell to support the crucible 130 and reserving an expansion gap, and setting an insulating member 3 at the passage of the heating mechanism 4, the problems of crucible 130 being crushed or shell 110 being deformed due to mismatch in the thermal expansion coefficients of different material components in the prior art, as well as the technical problems of heating electrodes being prone to short circuit breakdown with shell 110 at high temperatures, are effectively solved. Thus, while ensuring the electrical safety of the equipment, the structural stability and service life of the evaporation source under repeated hot and cold cycles are significantly improved, and the damage rate of core components is reduced.

[0090] To address the issue of droplet splashing during the initial melting stage of materials due to the rupture of internal air bubbles or uneven heating, please refer to [link to relevant documentation]. Figure 1 , Figure 4 , Figure 5 and Figure 6In some embodiments, a floating vortex mechanism 7 is specifically provided at a key node in the airflow channel of the evaporator. This floating vortex mechanism 7 mainly consists of a precisely fitted valve seat 710 and a valve core 720, forming a pneumatically self-regulating dynamic valve system. The valve seat 710 is mounted on the middle cover 220 and located at the communication port 221. The valve seat 710 has a frustum-shaped or conical valve body space 711 inside. A first valve port communicating with the first flow space is opened on the side of the valve body space 711 near the inner cover 230, and a second valve port communicating with the second flow space is opened on the side of the valve body space 711 near the outer cover 210. The diameter of the second valve port is larger than that of the first valve port. The valve core 720 is frustum-shaped or conical, matching the shape of the valve body space 711, and is at least partially movable within the valve body space 711. The outer wall of the valve core 720 has several evenly distributed circumferentially oriented... The spiral guide groove 721 extends axially along the valve core 720, and the extension direction of the spiral guide groove 721 extends from the end of the valve core 720 near the inner cover 230 to the end of the valve core 720 away from the inner cover 230; wherein, when the pressure of the evaporating gas flow in the first flow space is less than a first preset pressure value, the valve core 720 blocks the valve body space 711 under the action of gravity; when the pressure of the evaporating gas flow is greater than the first preset pressure value, the valve core 720 is lifted by the evaporating gas flow and rotates using the spiral guide groove 721, and the evaporating gas flow enters the second flow space through the gap between the valve core 720 and the inner wall of the valve body space 711.

[0091] The valve seat 710 is the stator part of the mechanism, which is set on the middle cover 220 and located at the communication port 221, and serves to support and limit the flow. The valve seat 710 defines a specific valve body space 711, which has a geometric shape of frustum or cone (i.e., inverted cone structure) that is larger at the top and smaller at the bottom.

[0092] The valve body space 711 has two openings in the vertical direction. A first valve port is provided on the side near the inner cover 230 (i.e., the bottom), which directly communicates with the first flow space between the inner cover 230 and the middle cover 220, serving as the inlet for the evaporative airflow. A second valve port is provided on the side near the outer cover 210 (i.e., the top), which communicates with the second flow space between the middle cover 220 and the outer cover 210, serving as the outlet for the airflow.

[0093] Based on the inverted conical geometry, the diameter of the upper second valve port is significantly larger than that of the lower first valve port. This design creates an outwardly expanding slope on the inner wall of the valve seat 710, providing a spatial basis for the floating of the valve core 720 and flow regulation.

[0094] The valve core 720 is the moving part of the mechanism, and its overall appearance is frustum-shaped or conical, which is highly matched with the shape of the valve body space 711 inside the valve seat 710. The valve core 720 is movably placed (i.e. not fixedly connected) in the valve body space 711 and sits on the inner wall of the valve seat 710 by its own weight.

[0095] In the initial state, the outer wall of the valve core 720 is tightly fitted with the inner wall of the valve seat 710, forming a surface seal or a line seal.

[0096] The spiral guide grooves 721 are the most crucial feature of the valve core 720. Several (e.g., three, four, or more) spiral guide grooves 721, evenly distributed circumferentially, are formed on the conical outer wall of the valve core 720. These guide grooves are not straight grooves, but extend spirally along the axial direction of the valve core 720. Specifically, the extension direction is: starting from the end of the valve core 720 near the inner cover 230 (bottom / small end), spiraling upwards towards the end away from the inner cover 230 (top / large end). These guide grooves, like miniature turbine blades, can convert linear airflow into rotational power.

[0097] The operation of the floating swirl mechanism 7 is a passive adaptive process based on differential pressure control, mainly divided into two stages: gravity blocking and aerodynamic swirl.

[0098] In the gravity-sealing stage (anti-splash state), during the initial heating phase, the material to be evaporated has just begun to melt, resulting in a low evaporation rate and low pressure of the evaporating gas flow within the first flow space (less than the first preset pressure value). At this time, the upward gas thrust on the valve core 720 is insufficient to overcome its own gravity. Therefore, the valve core 720 falls naturally under the influence of gravity, tightly adhering to the inner wall of the valve seat 710, thus sealing the valve body space 711.

[0099] At this time, if an air bubble bursts in the crucible 130, the splashed droplets will be physically blocked by the tightly pressed valve core 720 and will not be able to pass through the connecting port 221 to enter the upper space, thus effectively protecting the surface smoothness of the film.

[0100] During the pneumatic swirl stage (working state), as the temperature rises, the material vaporizes violently, and the pressure of the evaporating gas flow in the first flow space increases sharply (greater than the first preset pressure value). The high-pressure gas flow acts on the bottom of the valve core 720, and the resulting thrust overcomes the gravity of the valve core 720, pushing the valve core 720 upward.

[0101] Because the valve seat 710 is an inverted cone shape that is wider at the top and narrower at the bottom, when the valve core 720 rises, an annular flow gap is formed between the side wall of the valve core 720 and the inner wall of the valve seat 710. The greater the airflow, the higher the valve core 720 is pushed up, and the larger the gap becomes, thus achieving adaptive flow regulation.

[0102] When the high-speed airflow passes through the spiral guide groove 721 on the side wall of the valve core 720, the airflow generates a tangential force on the groove wall. This force drives the valve core 720 to rotate at high speed around its central axis. The high-speed rotating valve core 720 not only forms a stable vortex in the passing airflow, which helps the airflow to be fully mixed and uniform before entering the second flow space, but also the centrifugal force generated by the rotation can dislodge tiny impurities that may adhere to the surface of the valve core 720, thus playing a self-cleaning role.

[0103] This mechanism is suitable for high-vacuum, high-temperature physical vapor deposition environments. The valve core 720 and valve seat 710 must be made of materials with similar coefficients of thermal expansion (preferably the same material, such as high-purity graphite) to prevent uneven expansion at high temperatures from causing the valve core 720 to jam or resulting in excessive clearance. Furthermore, this mechanism relies on gravity for repositioning; therefore, the evaporation unit must be installed vertically to ensure that the valve core 720's axis aligns with the direction of gravity.

[0104] Although the embodiments describe a frustum shape, in some scenarios with extremely high sealing requirements, the bottom of the valve core 720 can be designed as a spherical cone to achieve better self-centering. Furthermore, the depth, pitch, and number of the spiral guide grooves 721 can be adjusted according to the viscosity of the evaporating material and the required steam flow rate. For high-flow-rate evaporation sources, the guide grooves can be deepened or the number of grooves increased.

[0105] In this embodiment, because the present invention employs a floating swirling mechanism 7 comprising an inverted conical valve seat 710 and a valve core 720, and a spiral guide groove 721 uniformly distributed circumferentially is formed on the side wall of the valve core 720, it effectively solves the technical problems in the prior art where droplets splash and damage the film surface due to bubble rupture or uneven heating in the early stage of material melting, as well as the uneven distribution of evaporation gas flow. Thus, it realizes the automatic sealing of the splash channel by gravity at low pressure, and the conversion of the straight air flow into a swirling flow to drive the valve core 720 to spin during high-pressure evaporation. This ensures the smoothness of the film surface through physical interception and homogenizes the evaporation gas flow through pneumatic swirling flow, significantly improving the film quality.

[0106] Furthermore, to ensure that the floating valve core 720 maintains a stable rotational posture under high-speed airflow and to prevent it from tilting, swaying, or deviating from its predetermined trajectory while suspended, this embodiment specifically provides a rotational guiding and stabilizing mechanism between the top of the valve core 720 and the outer cover 210. Please refer to... Figures 5 to 6The rotary guide stabilizing mechanism mainly consists of an annular raceway 722 on the top of the valve core 720 and several guide components 6 disposed below the outer cover 210. The center of the annular raceway 722 is collinear with the central axis of the valve core 720, and the guide components 6 are distributed circumferentially along the annular raceway 722. Each of the guide components 6 includes a fixed tube 610, a counterweight rod 620, a limiting member 630, and a ball bearing 640. One end of the fixed tube 610 is connected to the outer cover 210, and the other end is disposed towards the middle cover 220. The counterweight rod 620 is movably inserted into the fixed tube 610 and at least partially protrudes and extends beyond the end of the fixed tube 610 facing the middle cover 220. The limiting member 630 is disposed at the end of the counterweight rod 620 extending beyond the fixed tube 610. The limiting member 630 has a spherical groove, and an opening communicating with the spherical groove is provided on the side of the limiting member 630 near the annular raceway 722. The ball bearing 640 is disposed in the spherical groove, and at least partially exposes the spherical groove through the opening and rolls against the annular raceway 722. When the evaporation device is in operation, the counterweight rod 620 uses its own weight to apply a downward resisting force to the annular raceway 722 through the ball bearings 640.

[0107] On the end of the valve core 720 away from the inner cover 230 (i.e., the top surface of the valve core 720), a continuous groove 2321, namely an annular raceway 722, is precision machined. The geometric center of this annular raceway 722 is strictly collinear with (i.e. concentrically set) the central axis of rotation of the valve core 720, serving as a reference trajectory for rotation guidance. The cross-sectional shape of the annular raceway 722 is typically designed as an arc or V-shape that matches the curvature of the ball 640. This cross-sectional design restricts the radial movement of the ball 640, ensuring the uniqueness of the trajectory of the ball 640 as it rolls within it.

[0108] Within the space between the outer cover 210 and the middle cover 220 of the evaporator, several sets (e.g., three or four sets) of guide components 6 are provided. These guide components 6 are distributed circumferentially along the annular raceway 722, preferably evenly and symmetrically distributed (e.g., three sets of components are distributed in an equilateral triangle) to apply a uniform circumferential balancing force to the valve core 720 using multi-point constraints.

[0109] Each guide component 6 is a constant force clamping unit designed based on the principle of gravity, specifically including a fixed tube 610, a counterweight rod 620, a limiting component 630, and a ball bearing 640.

[0110] The fixing tube 610 serves as the mounting base and guide housing 110 of the component. One end of the fixing tube 610 is fixedly connected to the inner surface of the outer cover 210, and the other end extends vertically downward toward the middle cover 220. The fixing tube 610 has a smooth receiving cavity inside, which provides a guide channel for the vertical lifting and lowering of the counterweight rod 620.

[0111] The counterweight 620 is the core force-applying component. It is movably inserted into the receiving cavity of the fixed tube 610 and is designed with a clearance fit to ensure that the counterweight 620 can slide freely up and down along the axial direction of the fixed tube 610 without jamming. The length of the counterweight 620 is designed so that it at least partially protrudes and extends beyond the end of the fixed tube 610 facing the middle cover 220. In order to provide sufficient downforce within a limited volume, the counterweight 620 is made of a high-temperature resistant and high-density material, such as tungsten, molybdenum, or their alloys.

[0112] A limiting member 630 is located at the lower end (i.e., the end) of the counterweight rod 620 extending beyond the fixing tube 610, and is used to mount the ball bearing 640. The limiting member 630 has a finely machined spherical groove, the inner diameter of which is slightly larger than the diameter of the ball bearing 640 to allow the ball bearing 640 to rotate freely within it. Simultaneously, the limiting member 630 has an opening (reduced opening structure) on its side (bottom surface) near the annular raceway 722, communicating with the spherical groove. The diameter of this opening is smaller than the diameter of the ball bearing 640, which both prevents the ball bearing 640 from falling out and allows a portion of the ball bearing 640 to be exposed outside the limiting member 630 through this opening.

[0113] The ball bearing 640 is disposed within a spherical groove and is typically made of high-temperature resistant ceramic (such as silicon nitride, zirconium oxide) or hard alloy material. The exposed portion of the ball bearing 640 is directly embedded in the annular raceway 722 at the top of the valve core 720, forming a rolling contact relationship with the raceway surface through point or line contact.

[0114] The working process of this rotary guide stabilizing mechanism is a process of dynamic constraint using constant gravity.

[0115] When the evaporator is not operating or the airflow is low, the valve core 720 is in a low position. At this time, the counterweight rod 620 in the guide assembly 6 slides downward along the fixed tube 610 under its own weight, and the lower limiting member 630 presses the ball 640 tightly into the annular raceway 722 at the top of the valve core 720. This continuous gravitational contact restricts the radial degree of freedom of the valve core 720, ensuring that the valve core 720 is always located on the central axis of the device and preventing its initial position from deviating.

[0116] When the high-pressure evaporative gas flow lifts the valve core 720 and drives it to rotate, the valve core 720 will generate an upward axial displacement. At this time, the top surface of the valve core 720 pushes the ball 640 upward, which in turn drives the limiting member 630 and the counterweight rod 620 to slide upward along the fixed tube 610. No matter how high the counterweight rod 620 is lifted, its own weight is always vertically downward, acting on the annular raceway 722 through the ball 640, forming a constant and continuous downward resisting force.

[0117] Since the ball 640 can rotate freely in the spherical groove of the limiting member 630, when the valve core 720 rotates at high speed, the ball 640 and the annular raceway 722 experience rolling friction, which greatly reduces the resistance to relative motion and ensures that the rotation speed of the valve core 720 is not affected.

[0118] If airflow fluctuations cause the valve core 720 to tilt or become eccentric (e.g., one side higher than the other), since the guide components 6 are symmetrically distributed, the raised side of the valve core 720 will push up the corresponding counterweight rod 620, and the gravity of the counterweight rod 620 will immediately generate a reverse restoring torque. At the same time, on the lowered side of the valve core 720, the corresponding counterweight rod 620 will also lower to maintain contact, preventing the valve core 720 from derailing. This mechanism is like a gravity-adaptive dynamic bearing, forcibly pressing the valve core 720 back to a horizontal and centered position, ensuring its smooth, suspended rotation.

[0119] This rotary guide stabilizing mechanism is particularly suitable for physical vapor deposition (PVD) environments with ultra-high temperatures (e.g., above 1800 degrees Celsius) and extremely high vacuum requirements. In such environments, conventional elastic elements (such as metal springs) are prone to high-temperature creep, stress relaxation, or even annealing failure, resulting in a loss of elastic clamping force. This solution utilizes constant gravity as the driving force; the weight of the counterweight rod 620 does not change with temperature increases, making it particularly suitable for such extreme conditions. Simultaneously, the thermal expansion coefficients of the materials of the fixing tube 610 and the counterweight rod 620 must match to prevent slippage and jamming due to uneven expansion at high temperatures.

[0120] In this embodiment, an annular raceway 722 collinear with the central axis is opened at the top of the valve core 720. This is combined with several gravity guide components 6 on the outer cover 210, including a counterweight rod 620 movably inserted into the fixed tube 610 and ball bearings 640. The counterweight rod 620's own weight applies a continuous downward abutting force to the annular raceway 722 through the ball bearings 640. Therefore, the technical problem in the prior art where the floating valve core 720 easily tilts, shakes, or even deviates from its predetermined rotation trajectory under high-speed airflow, leading to sealing failure or jamming, is effectively solved. This achieves the restriction of the valve core 720's degrees of freedom using multi-point gravity rolling contact, converting sliding friction into low-resistance rolling friction. This ensures that the valve core 720 always rotates stably and at high speed around the central axis in a high-temperature pneumatic suspension state. Simultaneously, the constant gravity characteristic ensures the long-term operational reliability of the device in ultra-high temperature environments.

[0121] To address the common problem in traditional evaporation sources where the cover plate temperature is lower than the crucible bottom temperature (130°C), leading to condensation and scaling at the steam outlet, this embodiment integrates a passive directional heat conduction system, namely heat-conducting component 9, within the evaporation device. Please refer to... Figures 1 to 5 The heat-conducting component 9 is designed as a highly efficient thermal bridge structure, mainly composed of an upper heating part 910 and a lower heat transfer part 920 integrally formed or tightly connected. The heating part 910 is disposed within the first flow space and surrounds the bottom of the valve seat 710 or surrounds the communication port 221 of the middle cover 220. One end of the heat transfer part 920 is connected to the heating part 910, and the other end extends into the first accommodating space and is disposed near the outer wall of the crucible 130. Furthermore, the heating part 910 is a ring structure coaxially arranged with the communication port 221, and the heat-conducting component 9 is made of a high-temperature resistant, high-thermal-conductivity material.

[0122] The heating element 910 is disposed within the first flow space formed between the inner cover 230 and the middle cover 220. In terms of spatial layout, the heating element 910 is constructed as a ring structure, and this ring structure is coaxially aligned with the communication port 221 on the middle cover 220 and the valve seat 710 mounted thereon. The heating element 910 tightly surrounds the bottom outer periphery of the valve seat 710 or directly adheres to the edge region of the communication port 221. This surrounding design aims to ensure that heat can be evenly radiated or conducted to the entire valve seat 710 area, eliminating localized cold spots.

[0123] The heat transfer section 920 serves as a heat transport channel. One end is physically connected to (or integrated with) the heating section 910 located above, while the other end extends downward, passing through a pre-reserved hole or gap in the inner cover 230, and extending into the first accommodating space within the outer shell 110 of the main body 1. The lower end of the heat transfer section 920 extends to the area near the outer wall of the crucible 130, or directly to the high-temperature radiation core area of ​​the heating mechanism 4 (such as tungsten stranded wire).

[0124] To achieve extremely low heat transfer loss, the heat-conducting component 9 is made entirely of high-melting-point, high-thermal-conductivity materials, such as high-temperature ceramics and directional pyrolytic graphite.

[0125] The working principle of the heat-conducting component 9 in this embodiment is based on the thermodynamic directional conduction mechanism, aiming to break the natural thermal gradient distribution:

[0126] When the evaporation device is started, the heating mechanism 4 at the bottom begins to operate, bringing the crucible 130 area to an extremely high evaporation temperature. At this time, the lower end of the heat transfer section 920, which extends to the high-temperature zone, acts as a heat absorption end, absorbing a large amount of radiant heat from the heating mechanism 4 and conductive heat from the outer wall of the crucible 130. Due to the extremely high thermal conductivity of the heat-conducting component 9, this heat is rapidly and with minimal loss conducted upwards along the heat transfer section 920 to the heating section 910 at the top.

[0127] After the heat reaches the heating section 910, the annular structure acts as a heat release end, forcibly transferring the heat to the connecting port 221 of the middle cover 220 and the valve seat 710. This active heat compensation mechanism forcibly raises the temperature of the valve seat 710 area, keeping it consistently above the melting point of the material to be evaporated. Therefore, when high-temperature steam flows through this area, the valve port surface does not have the temperature difference conditions necessary for physical condensation, preventing the steam from liquefying or depositing here. This physically eliminates scaling and clogging, ensuring the long-term unobstructed flow of the evaporation channel.

[0128] The heat-conducting component 9 also forms a key synergistic effect with the precision valve structure. Because the heat-conducting component 9 ensures that the valve seat 710 is in a high-temperature dry state (i.e., no liquid metal condensation on the surface), the valve core 720 and the valve seat 710 can be designed with extremely high precision to prevent splashing, without worrying about sticking and jamming caused by liquid metal seeping into the gap and solidifying after cooling.

[0129] This structure is suitable for all vacuum evaporation sources that rely on bottom heating and are prone to condensation due to temperature differences at the top. It is particularly suitable for evaporation processes of metal materials with high melting points and temperature-sensitive vapor pressure. Since the heat-conducting component 9 is directly in the high-temperature zone, its material must be heat-resistant and not produce volatile impurities under vacuum.

[0130] In practice, the heat-conducting component 9 can be a directional pyrolytic graphite bushing that is tightly attached to the outer wall of the ceramic crucible 130; or it can be an array of vertically arranged molybdenum heat-conducting rods embedded in the side wall of the ceramic crucible 130. An interference fit can be used between the heating part 910 and the valve seat 710 to reduce the contact thermal resistance, or a high-temperature resistant heat-conducting putty can be coated on the contact surface.

[0131] In this embodiment, by employing a heat-conducting element 9 comprising an annular heating part 910 surrounding the valve seat 710 and a heat transfer part 920 extending to the high-temperature zone of the outer wall of the crucible 130, the technical problems in the prior art, such as steam condensing and scaling at the outlet and blocking the channel due to the temperature of the cover plate area being lower than that of the bottom of the crucible 130, as well as precision valves sticking and jamming due to condensate, are effectively solved. This allows for the forced increase of the valve seat 710 temperature to above the melting point through directional heat conduction, physically eliminating condensation conditions, ensuring the stability of evaporation distribution, and making high-precision anti-splash sealing possible, thus avoiding the risk of mechanical jamming during operation.

[0132] To address the issue of cold welding jamming that easily occurs in precision valve structures after high-temperature evaporation and cooling, and to balance the conflict between low-temperature exhaust and high-temperature sealing, this embodiment integrates a differential separation mechanism 8 based on the difference in material thermal expansion properties within the cover 2 component of the evaporator. (See also...) Figures 1 to 5The differential separation mechanism 8 includes a spacer ring 810 disposed on the top of the inner cover 230 and a push rod 820 disposed on the top of the inner cover 230. One end of the push rod 820 is fixed to the inner cover 230, and the other end extends to the first valve port and is directly opposite the bottom of the valve core 720. The coefficient of thermal expansion of the push rod 820 is less than that of the spacer ring 810. At a first preset temperature, the end of the push rod 820 away from the inner cover 230 abuts against the end of the valve core 720 near the inner cover 230, raising the valve core 720 relative to the valve seat 710 to a first target height, thereby forming an exhaust gap between the side of the valve core 720 and the inner wall of the valve body space 711. At a second preset temperature higher than the first preset temperature, after the spacer ring 810 expands due to heat, the end of the spacer ring 810 away from the inner cover 230 abuts against the side of the middle cover 220 near the inner cover 230, raising the middle cover 220 to a second target height, so that the inner wall of the valve body space 711 fits against the side of the valve core 720, and the second target height is greater than the first target height. Furthermore, a movable gap is provided between the side of the middle cover 220 away from the inner cover 230 and the side of the outer cover 210 close to the middle cover 220, the movable gap being at least equal to the second target height; a counterweight 240 is provided in the movable gap, the counterweight 240 being disposed on the side of the middle cover 220 away from the inner cover 230, and applying pressure to the middle cover 220 in the direction of the inner cover 230 using its own weight.

[0133] The core of this differential separation mechanism 8 lies in using the difference in dimensional changes between two materials with different coefficients of thermal expansion to generate relative displacement.

[0134] The push rod 820 is a low-expansion element, located at the top center of the inner cover 230. One end (lower end) of the push rod 820 is firmly fixed to the inner cover 230 as a positional reference; the other end (upper end) extends vertically upward, passing through the space between the inner cover 230 and the middle cover 220, reaching the first valve port, and directly facing the bottom plane of the upper valve core 720. Crucially, the push rod 820 is made of a material with a low coefficient of thermal expansion (e.g., tungsten or carbon composite material), meaning its length increases less with increasing temperature.

[0135] The spacer ring 810 is a high-expansion element, also located on top of the inner cover 230, surrounding the outer periphery of the push rod 820 or located at the edge of the inner cover 230. As a structural component supporting the middle cover 220, the spacer ring 810's lower end supports the inner cover 230, and its upper end supports the middle cover 220. The spacer ring 810 is made of a material with a high coefficient of thermal expansion (e.g., alumina ceramic), meaning that under the same temperature rise, its axial elongation is significantly greater than that of the push rod 820.

[0136] To ensure that the middle cover 220 can move up and down in sync with the expansion and contraction of the spacer ring 810 without becoming suspended or lagging behind, a movement gap is provided between the side of the middle cover 220 away from the inner cover 230 (i.e., the top of the middle cover 220) and the side of the outer cover 210 near the middle cover 220 (i.e., the inner wall of the bottom of the outer cover 210). The height of this movement gap is precisely calculated and must be at least equal to or greater than the theoretical stroke of the middle cover 220 in its maximum expansion state. A high-temperature resistant counterweight 240 is installed within this movement gap. The counterweight 240 is designed as a ring-shaped block structure, placed on the top plane of the middle cover 220, and located within the movement gap. Its material is preferably a high-temperature resistant and high-density material such as tungsten, molybdenum, or high-density graphite. Using the weight of the counterweight 240 itself, a continuous gravitational pressure (i.e., gravity preload) is applied to the middle cover 220 in the direction of the inner cover 230. This force ensures that the middle cover 220 is always pressed tightly against the spacer ring 810, so that the lifting and lowering movement of the middle cover 220 is strictly synchronized with the thermal expansion and contraction of the spacer ring 810.

[0137] The working principle of this differential separation mechanism 8 is a fully automatic temperature-displacement timing control process that does not require electronic sensors, mapping process steps to temperature changes:

[0138] During the low-temperature exhaust stage (first preset temperature, such as room temperature), when the device is at room temperature or just beginning to be evacuated, the length of the push rod 820 is designed to be slightly longer than the combined height of the spacer ring 810 support. Therefore, the end of the push rod 820 away from the inner cover 230 (the top) will pass through the valve port and directly abut against the bottom of the valve core 720, forcibly pushing the valve core 720 upward relative to the valve seat 710 by a preset distance (first target height).

[0139] At this point, an exhaust gap is artificially created between the side of the valve core 720 and the inner wall of the valve body space 711. This allows water vapor and organic gases adsorbed inside the crucible 130 and on the surface of the material to be smoothly discharged in the early stage of preheating, preventing impurities from being trapped inside the crucible 130 and contaminating the subsequent film.

[0140] During the heating and locking phase (transitioning to the second preset temperature), the device temperature gradually increases as the heating mechanism 4 operates. At this time, both the spacer ring 810 and the push rod 820 are thermally expanding. However, due to the large coefficient of thermal expansion of the spacer ring 810, its elongation rate is much faster than that of the push rod 820.

[0141] The heated and expanded spacer ring 810 pushes the middle cover 220 (valve seat 710) upwards. During this process, the counterweight 240 on top of the middle cover 220 is also lifted, and its gravity constantly presses the middle cover 220 downwards, ensuring that the middle cover 220 rises smoothly. When the temperature rises to a certain level (before the material melts), the expansion increment of the spacer ring 810 exceeds the initial protrusion of the push rod 820. At this time, the height to which the middle cover 220 is lifted (the second target height) exceeds the height to which the push rod 820 lifts the valve core 720.

[0142] In contrast, the push rod 820 retracts below the valve seat 710. The valve core 720, no longer supported by the push rod 820, falls back under gravity, its side re-fitting tightly against the inner wall of the valve body space 711. At this point, the device enters a sealed state, preventing splashing of liquid droplets during subsequent material melting.

[0143] During the cooling and weld breaking stage (shutdown for temperature reduction), heating stops when evaporation ends, and the device begins to cool. Due to its large coefficient of thermal expansion, the spacer ring 810 contracts faster than the push rod 820.

[0144] As the spacer ring 810 shortens rapidly, the counterweight 240 located above the middle cover 220 uses its own weight to overcome the friction that may exist between the middle cover 220 and the guide component, forcibly pushing the middle cover 220 down along with the spacer ring 810. Meanwhile, the push rod 820 retracts more slowly, and relatively speaking, the top of the push rod 820 protrudes out of the valve seat 710 again.

[0145] At some point during the cooling process, the push rod 820 presses against the bottom of the valve core 720 again. As the middle cover 220 continues to descend under the weight of the counterweight 240, the push rod 820 applies a significant mechanical lifting force to the valve core 720. This force is sufficient to physically shear or destroy the microscopic cold weld or adhesive layer formed between the valve core 720 and the valve seat 710 due to the condensation of metal vapor, forcibly pushing the valve core 720 open and allowing the device to automatically return to its room-temperature exhaust state, ready for the next use.

[0146] This differential separation mechanism 8 is suitable for vacuum evaporation environments with significant temperature cycling (from room temperature to temperatures above 1000 degrees Celsius). In such environments, conventional elastic elements cannot maintain their performance over long periods, while this solution utilizes gravity reset, unaffected by temperature. The materials of the push rod 820 and the spacer ring 810 must have significantly different thermal expansion properties and stable performance, preventing high-temperature creep. Simultaneously, the counterweight 240 must be made of a material with a melting point higher than the operating temperature and that does not volatilize in a vacuum.

[0147] In this embodiment, a differential separation mechanism 8 comprising a low-thermal-expansion-coefficient push rod 820 and a high-thermal-expansion-coefficient spacer ring 810 is employed, along with a high-temperature resistant counterweight 240 positioned within the moving gap between the outer cover 210 and the middle cover 220. The relative position of the valve core 720 and the middle cover 220 is controlled by utilizing the dimensional differences between the spacer ring 810 and the push rod 820 at different temperatures. Furthermore, the constant gravity of the counterweight 240 replaces the elastic element to drive the middle cover 220 to reset. Therefore, this effectively solves the timing conflict between low-temperature exhaust and high-temperature sealing in existing technologies, as well as the mechanical jamming problem where the valve core 720 and valve seat 710 cannot be reopened due to metal vapor solidification after high-temperature evaporation and cooling. Simultaneously, it avoids the risk of elastic element failure in ultra-high temperature environments. This achieves fully automatic timing operation without electronic control and reliable reset by forcibly breaking cold weld adhesions using thermal shrinkage stress differences, significantly improving the reusability and process stability of the equipment.

[0148] Furthermore, to address the potential for mutual compression, cracking, or structural failure of the various precision components within the evaporator under high-temperature conditions due to differences in their thermal expansion coefficients, this embodiment features a targeted design for the mating structure and key materials of the cover assembly 2. Please refer to [link / reference]. Figure 5 The bottom center of the middle cover 220 is provided with a protrusion 232 extending towards the inner cover 230, and the center of the protrusion 232 has a groove 2321 for the insertion of the top rod 820; the spacer ring 810 is sleeved on the outer periphery of the protrusion 232, and the inner diameter of the spacer ring 810 is larger than the outer diameter of the protrusion 232 at the first preset temperature, so as to allow the spacer ring 810 and the middle cover 220 to undergo relative thermal expansion displacement. The spacer ring 810 is made of alumina ceramic material, and the top rod 820 is made of tungsten or carbon composite material; the valve core 720 is frustoconical, and the end face of the valve core 720 near the inner cover 230 is an abutment plane, and the top end of the top rod 820 abuts against the abutment plane at the first preset temperature.

[0149] At the bottom center of the middle cover 220, a protrusion 232 extending downwards (i.e., towards the inner cover 230) is integrally formed or fixedly connected. This protrusion 232 serves as a positioning reference for the connection between the middle cover 220 and the lower component. A groove 2321 (or through-hole channel) is provided at the central axis of the protrusion 232 for the top rod 820 to pass through or be inserted. A support spacer ring 810 is fitted onto the outer periphery of the protrusion 232. A key design feature is the allowance for tolerance: at room temperature (i.e., the first preset temperature) and during the initial heating phase, the inner diameter of the spacer ring 810 is designed to be significantly larger than the outer diameter of the protrusion 232. This means that there is a pre-defined annular radial gap (thermal expansion buffer gap) between the inner wall of the spacer ring 810 and the outer wall of the protrusion 232.

[0150] The spacer ring 810 is made of alumina ceramic material. Alumina ceramic not only has excellent high-temperature insulation and compressive strength, but also has a relatively high coefficient of thermal expansion among ceramic materials, which can provide sufficient thermal actuation stroke.

[0151] The push rod 820 is made of tungsten or carbon composite material. These materials have extremely high melting points and extremely low coefficients of thermal expansion, ensuring dimensional stability at high temperatures and serving as a "stationary" reference.

[0152] The valve core 720 is designed in a frustum shape (i.e., a truncated cone). Unlike the pointed cone bottom, in this embodiment, the end of the valve core 720 near the inner cover 230 (i.e., the bottom) is machined into a flat abutment surface. The top end of the mating push rod 820 is designed to make stable contact with this surface (such as a flat or arc surface). At a first preset temperature (such as room temperature), the top end of the push rod 820 directly abuts against the abutment surface at the bottom of the valve core 720, thereby lifting the valve core 720.

[0153] When the device is heated, both the middle cover 220 (typically made of graphite) and the spacer ring 810 (made of alumina) undergo radial expansion. Since the coefficient of thermal expansion of alumina is generally greater than that of graphite, or their heating rates differ, if they are tightly fitted together, the inner protrusion 232 may crack the outer spacer ring 810, or the outer spacer ring 810 may clamp the inner protrusion 232. In this embodiment, as the temperature rises, the protrusion 232 of the middle cover 220 expands outward. Because a sufficient radial clearance is provided, the expansion of the protrusion 232 is absorbed by this clearance and will not contact or compress the inner wall of the spacer ring 810. This makes the spacer ring 810 and the middle cover 220 "decoupled" in the radial direction, without interfering with each other, maintaining force transmission only in the axial direction.

[0154] The push rod 820 pushing the valve core 720 is a mechanical transmission process. If the bottom of the valve core 720 is pointed, and the push rod 820 is also pointed, it is extremely difficult for the two to align, and they are prone to slippage under airflow turbulence. By designing the bottom of the valve core 720 as a contact surface, the contact area is increased. Even if the push rod 820 or the valve core 720 experiences a slight lateral thermal displacement at high temperatures, the tip of the push rod 820 can still fall within the plane range of the bottom of the valve core 720, ensuring the reliability and stability of the lifting action and guaranteeing that the exhaust clearance is always maintained.

[0155] This structure is suitable for precision vacuum equipment with large temperature differences and sensitivity to structural stress. It is particularly suitable for applications where dissimilar materials (such as ceramics and metals, or ceramics and graphite) must be used. The required clearance must be precisely calculated to cover the maximum differential expansion throughout the entire process from room temperature to the maximum evaporation temperature.

[0156] In this embodiment, by adopting a structure in which a protrusion 232 is provided at the bottom of the middle cover 220 and a radial gap is reserved for the fitting of the spacer ring 810, and the frustum-shaped valve core 720 at the bottom of the plane abuts against the low expansion coefficient push rod 820, the problem of high-temperature structural expansion and cracking caused by the mismatch of thermal expansion coefficients of dissimilar materials in the prior art is effectively solved, as well as the technical problem of unstable contact and easy slippage between the push rod 820 and the valve core 720 under high temperature and airflow disturbance. Thus, while ensuring the structural integrity and lifespan of the device, the mechanical transmission stability and reliability of the valve core 720 lifting mechanism are ensured throughout the entire temperature range.

[0157] The above description is merely illustrative of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not depart from the content of this specification or exceed the scope defined by the claims, all of which should fall within the protection scope of this invention.

Claims

1. An evaporation apparatus, characterized in that, include: The main body includes: The outer casing includes a first accommodating space and a first opening communicating with the first accommodating space; A crucible disposed within the first accommodating space, the crucible including a second accommodating space for accommodating the material to be evaporated, the second accommodating space extending along the axial direction of the crucible to the surface of the crucible to form a second opening, the second opening communicating with the first opening; A heat insulation layer is disposed between the outer shell and the crucible; A heating mechanism, at least partially disposed in the first accommodating space and located between the insulation layer and the crucible, is used to heat the crucible; The lid includes an outer lid, a middle lid, and an inner lid arranged sequentially from the outside to the inside; the outer lid has a discharge port; the middle lid has a connecting port corresponding to the discharge port, and a second flow space for evaporation gas flow is formed between the middle lid and the outer lid; the inner lid has an evaporation hole, and a first flow space for evaporation gas flow is formed between the inner lid and the middle lid; the projection of the evaporation hole on the axial direction of the crucible is offset from the projection of the connecting port on the axial direction of the crucible. The floating vortex mechanism includes: A valve seat is disposed on the middle cover and located at the communication port. The valve seat has a valve body space in the shape of a frustum or a cone. A first valve port communicating with the first flow space is opened on the side of the valve body space near the inner cover. A second valve port communicating with the second flow space is opened on the side of the valve body space near the outer cover. The diameter of the second valve port is larger than the diameter of the first valve port. The valve core is in the shape of a frustum or a cone that matches the shape of the valve body space. The valve core is at least partially movable within the valve body space. The outer wall of the valve core is provided with a plurality of spiral guide grooves evenly distributed in the circumferential direction. The spiral guide grooves extend along the axial direction of the valve core, and the extension direction of the spiral guide grooves extends from the end of the valve core near the inner cover to the end of the valve core away from the inner cover. When the evaporation device is in operation, the vaporization gas generated by the vaporization of the material to be evaporated in the crucible passes sequentially through the evaporation hole, the first flow space, the connecting port and the second flow space, and is discharged from the evaporation device from the discharge port.

2. The evaporation apparatus according to claim 1, characterized in that, The first opening of the outer shell is provided with an annular overlapping member, and the crucible is mounted on the outer shell through the annular overlapping member, so that the outer wall of the crucible and the inner wall of the insulation layer are kept apart; both the outer shell and the insulation layer are provided with a first through hole for the heating mechanism to pass through, and an insulating member is provided in the first through hole. The heating mechanism passes through the insulating member at least partially and extends to the outside of the main body.

3. An evaporation apparatus according to claim 1 or 2, characterized in that, When the pressure of the evaporating gas flow in the first flow space is less than the first preset pressure value, the valve core blocks the valve body space under the action of gravity; when the pressure of the evaporating gas flow is greater than the first preset pressure value, the valve core is lifted by the evaporating gas flow and rotates using the spiral guide groove, and the evaporating gas flow enters the second flow space through the gap between the valve core and the inner wall of the valve body space.

4. An evaporation apparatus according to claim 3, characterized in that: An annular raceway is provided on the end face of the valve core away from the inner cover, and the center of the annular raceway is collinear with the central axis of the valve core. The evaporation device further includes a plurality of guide components disposed between the outer cover and the middle cover, the guide components being distributed at circumferential intervals along the annular raceway; each guide component includes: A fixing tube, one end of which is connected to the outer cover and the other end of which is positioned toward the middle cover; A counterweight rod is movably inserted into the fixed tube and at least partially protrudes and extends beyond the end of the fixed tube facing the middle cover. A limiting member is provided at one end of the counterweight rod extending outside the fixed tube. A spherical groove is provided in the limiting member, and an opening communicating with the spherical groove is provided on the side of the limiting member near the annular raceway. A ball is disposed within the spherical groove, and the ball is at least partially exposed through the opening in the spherical groove and rolls against the annular raceway. When the evaporation device is in operation, the counterweight rod uses its own weight to apply a downward resisting force to the annular raceway through the ball bearings.

5. An evaporation apparatus according to claim 3, characterized in that, It also includes a heat-conducting component, which includes: A heating element is disposed within the first flow space and surrounding the bottom of the valve seat or surrounding the communication opening of the middle cover; A heat transfer section, one end of which is connected to the heating section, and the other end of which extends into the first accommodating space and is disposed near the outer wall of the crucible.

6. An evaporation apparatus according to claim 5, characterized in that, The heating element is a ring structure coaxially arranged with the communication port.

7. An evaporation apparatus according to claim 5, characterized in that, It also includes a differential separation mechanism, which comprises: A spacer ring is provided at the top of the inner cover; A push rod is provided on the top of the inner cover, one end of which is fixed to the inner cover, and the other end extends to the first valve port and is directly opposite the bottom of the valve core; the coefficient of thermal expansion of the push rod is less than that of the spacer ring. At a first preset temperature, the end of the push rod away from the inner cover abuts against the end of the valve core near the inner cover, raising the valve core relative to the valve seat to a first target height, thereby forming an exhaust gap between the side of the valve core and the inner wall of the valve body space. At a second preset temperature higher than the first preset temperature, after the spacer ring expands due to heat, the end of the spacer ring away from the inner cover abuts against the side of the middle cover near the inner cover, raising the middle cover to a second target height, so that the inner wall of the valve body space fits against the side of the valve core, and the second target height is greater than the first target height.

8. An evaporation apparatus according to claim 7, characterized in that, A movable gap is provided between the side of the middle cover away from the inner cover and the side of the outer cover close to the middle cover, the movable gap being at least equal to the second target height; a counterweight is provided within the movable gap, the counterweight being located on the side of the middle cover away from the inner cover, and applying pressure to the middle cover in the direction of the inner cover using its own weight.

9. An evaporation apparatus according to claim 7, characterized in that, The bottom center of the middle cover has a protrusion extending toward the inner cover, and the center of the protrusion has a groove for inserting the top rod; the spacer ring is sleeved on the outer periphery of the protrusion, and the inner diameter of the spacer ring is greater than the outer diameter of the protrusion at the first preset temperature, so as to allow the spacer ring and the middle cover to undergo relative thermal expansion displacement.

10. An evaporation apparatus according to claim 7, characterized in that, The spacer ring is made of alumina ceramic material, and the push rod is made of tungsten or carbon composite material; the valve core is frustum shaped, and the end face of the valve core near the inner cover is an abutting plane, and the top end of the push rod abuts against the abutting plane at the first preset temperature.

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