Continuous evaporation method and apparatus

Abstract

The application discloses a continuous evaporation method and device, comprising: providing an evaporator for accommodating and melting a once-added evaporation target material and forming a vapor; providing an external target material source capable of continuously providing a molten target material liquid with a temperature not lower than a target material melting point; providing a communication pipeline in communication with the external target material source to form a communication structure, and controlling a maximum liquid level in the communication pipeline to be higher than a liquid level in the evaporator to form a filling of the external target material molten liquid in the communication pipeline, thereby providing a target material input channel to the evaporator, and a preheating zone is arranged in the communication pipeline to heat the supplemented target material to a temperature, and a pipeline corresponding to the maximum liquid level in the communication pipeline is arranged at an output end of the preheating zone; and controlling an input liquid level of the external target material source to make the molten liquid liquid level in the crucible assembly stable. The application can continuously supplement the preheated molten target material liquid based on a crucible heating mode, reduce metal liquid temperature fluctuation, and prolong evaporation processing time.

Description

Technical Field

[0001] This invention relates to the field of current collector technology, and in particular to a continuous vapor deposition method and equipment. Background Technology

[0002] The most common method for uniformly coating metals, especially aluminum, is high-vacuum belt evaporation. Currently, when selecting a crucible as the heat source for evaporation, induction heating is generally chosen. The operation typically involves placing the metal target in the crucible beforehand, melting the metal target through induction heating, and then evaporating the molten target under vacuum to coat the substrate surface.

[0003] Based on the crucible method, the amount of contents in the crucible is related to the crucible volume. Therefore, in actual vapor deposition operations, it is necessary to calculate the amount of target material in the crucible. In the vapor deposition process of composite current collectors, considering the need to maintain a vacuum environment in the vapor deposition chamber, the chamber is generally not opened to add target material before the vapor deposition is completed. Therefore, the length of the vapor-deposited base film is also limited.

[0004] To address the aforementioned technical problems, existing technologies, such as Chinese Patent Publication No. CN212451608U, disclose a crucible capable of continuous wire feeding. This crucible includes a crucible body with a recessed cavity at its top. The crucible also includes a nested pot, a crucible lid, and a wire feeding clearance channel. The nested pot, which mates with the recessed cavity, is snap-fitted to the crucible body. The nested pot includes a pot cavity and a pot opening communicating with the pot cavity. The crucible lid, which mates with the nested pot and is used to seal the pot opening, is placed over the pot opening of the nested pot. A wire feeding clearance channel communicating with the pot cavity is provided in the middle of the crucible lid.

[0005] This patent is essentially similar to the vapor deposition method of an evaporation boat. The aluminum wire is fed into the heating chamber of the crucible, and the molten aluminum dripping down will cause the temperature of the molten metal to fluctuate, affecting the evaporation rate. In particular, the relatively high temperature of the molten metal in the crucible is mainly concentrated in the upper part, which may also aggravate the splashing of the molten metal.

[0006] Therefore, further improvements are needed. Summary of the Invention

[0007] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, one objective of this invention is to provide a continuous vapor deposition method that, based on crucible heating, allows for the continuous replenishment of preheated molten target material, reducing temperature fluctuations in the molten metal and extending the length of the vapor deposition process.

[0008] The technical solution of the present invention is as follows:

[0009] A continuous vapor deposition method, comprising:

[0010] An evaporator is provided for containing and melting the vapor deposition target material added in one step and forming vapor, with the vapor deposition temperature set to T0;

[0011] It provides an external target material source, which can continuously supply molten target material liquid with a temperature T1 not lower than the melting point of the target material;

[0012] A connecting pipe is provided to form a communicating vessel structure with an external target material source, and the maximum liquid level in the connecting pipe is controlled to be higher than the liquid level in the evaporator, so as to form a filling of the external target material molten liquid in the connecting pipe, thereby providing a target material input channel to the evaporator. A preheating zone is set in the connecting pipe to heat the supplemented target material to temperature T2; the pipe corresponding to the maximum liquid level in the connecting pipe is set at the output end of the preheating zone.

[0013] Control the input liquid level of the external target material source to ensure a stable liquid level in the crucible assembly.

[0014] Furthermore, the temperature T2 is close to the vapor deposition temperature T0.

[0015] Furthermore, the output end of the connecting pipe is fed into the crucible assembly from above the opening of the crucible assembly, or connected to its internal space from the upper side of the evaporator.

[0016] Furthermore, a hot overflow zone is provided, which is set at the output end of the preheating zone and controlled to be higher than the liquid level of the target material source. The height difference is H, forming a barrier for the low-temperature molten liquid, so that the high-temperature molten liquid or its vapor and condensate after passing through the preheating zone can pass through the pipeline of the hot overflow zone, which plays the role of screening higher-temperature molten fluid.

[0017] Furthermore, the diameter of the heat overflow zone is 0.1-0.5 times the inner diameter of the pipe connected to it.

[0018] Furthermore, the liquid level control method of the target material source is to control the wire feed amount so that the height difference between it and the hot overflow zone is within the range of -H-0mm.

[0019] Furthermore, H≤10mm.

[0020] Furthermore, the liquid level in the preheating zone is lower than the liquid level at the inlet and / or outlet of the connecting pipe.

[0021] An apparatus for continuous vapor deposition, comprising:

[0022] The evaporation chamber provides a vacuum negative pressure environment for vapor deposition;

[0023] The conveying mechanism provides guide rollers for transporting the substrate material to be processed and allows for tension adjustment;

[0024] Also includes:

[0025] An evaporator, with a first heating component externally provided for heating the target material inside the evaporator;

[0026] A feeding device is used to continuously supply an external target material source, which contains molten vapor deposition solution;

[0027] The connecting pipeline is connected to the feeding device to form a communicating vessel structure. The maximum liquid level in the connecting pipeline is higher than the liquid level in the evaporator. A preheating pipeline is set on the connecting pipeline to form a preheating zone to further heat the replenished molten target material. The high-level pipeline is located at the output end of the preheating pipeline and extends into the evaporator.

[0028] Furthermore, the feeding device includes a liquid storage container and a feeding assembly for replenishing the target material. A second heating assembly is provided outside the liquid storage container for heating and melting the target material raw material.

[0029] Furthermore, the connecting pipeline includes an input pipeline connected to the liquid storage container and an output pipeline connected to the evaporator, with a preheating pipeline connected between the input and output pipelines.

[0030] Furthermore, the height difference between the bottom of the inner wall of the high-level pipeline and the stable liquid level in the target material source is H.

[0031] Furthermore, the height difference H ≤ 10mm.

[0032] Furthermore, the diameter of the elevated pipeline is 0.1-0.5 times the inner diameter of the pipeline it connects to.

[0033] Furthermore, the height of the preheating pipeline is lower than that of the input pipeline and / or output pipeline.

[0034] Furthermore, the output end of the high-level pipeline extends to below the liquid surface inside the crucible body.

[0035] The beneficial effects of this invention are as follows: Based on the continuous vapor deposition method of this application, continuous long-term vapor deposition operation can be achieved after one feeding, which improves the defect of limited vapor deposition length in large-capacity vapor deposition containers such as crucibles, and can also avoid the influence of direct wire feeding on the temperature of the system inside the container, and reduce a series of problems caused by aluminum liquid dripping due to wire feeding. Attached Figure Description

[0036] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0037] Figure 1 This is a flowchart of the continuous vapor deposition method proposed in this invention;

[0038] Figure 2This is a schematic diagram of the structure of the first embodiment;

[0039] Figure 3 This is a schematic diagram of the second embodiment.

[0040] In the diagram: 1-Crucible body; 2-Liquid storage container; 21-Liquid level control module; 3-Connecting pipeline; 31-Input pipeline; 32-Preheating pipeline; 33-Output pipeline; 34-High-level pipeline. Detailed Implementation

[0041] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0042] Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0043] Reference Figure 1 A continuous vapor deposition method, comprising:

[0044] S1 provides an evaporator, such as a crucible assembly, for containing and melting the vapor deposition target material added at one time and forming vapor, with the vapor deposition temperature set to T0;

[0045] S2 provides an external target material source that can continuously supply molten target material liquid with a temperature T1 not lower than the melting point of the target material.

[0046] S3 provides a connecting pipe to form a communicating vessel structure with the external target material source, and controls the maximum liquid level in the connecting pipe to be higher than the liquid level in the evaporator, so as to fill the external target material molten liquid in the connecting pipe, thereby providing a target material input channel to the evaporator; and a preheating zone is set in the connecting pipe to heat the supplemented target material to temperature T2, and the pipe corresponding to the maximum liquid level in the connecting pipe is set at the output end of the preheating zone; the temperature T2 is preferably close to the evaporation temperature T0 to further reduce the impact on the molten liquid in the evaporator container;

[0047] S4 controls the input liquid level of the external target material source to ensure a stable liquid level in the crucible assembly for continuous vapor deposition.

[0048] Further integration Figure 1 and Figure 2 This embodiment also discloses an apparatus for continuous vapor deposition, based on conventional vapor deposition equipment, which includes an evaporation chamber that provides a vacuum negative pressure environment for vapor deposition; and a related conveying mechanism that provides a set of guide rollers for the transfer of the substrate material (base film) to be processed and tension adjustment.

[0049] Also includes:

[0050] In this embodiment, the evaporator is configured as a crucible body 1, with a first heating component on its exterior for heating the crucible body 1. The crucible can be made of commercially available conventional materials, such as graphite or metal, and the corresponding heating component can be an induction coil. For crucibles made of ceramic or other materials, external resistance heating can also be used, such as using a heating coil at the bottom or a coil surrounding the bottom. Based on the heating method, if induction coil heating is selected, the crucible body 1 can be placed on a support base at a suitable height.

[0051] The feeding device is used to provide a replenishment source for external target material. It contains molten vapor deposition liquid and includes a liquid storage container 2 and a feeding assembly for replenishing the target material. A second heating assembly is provided outside the liquid storage container 2 to heat the molten target material. The second heating assembly is similar to the first heating assembly and is reasonably set based on the material of the liquid storage container. The feeding assembly can continuously supply the target material.

[0052] The connecting pipe 3 is connected to the feeding device and forms a communicating vessel structure. The maximum liquid level in the connecting pipe is higher than the liquid level in the evaporator, thereby providing a target material input channel to the evaporator. A preheating pipe 32 is set on the connecting pipe 3 to form a preheating zone, which further heats the replenished molten target material.

[0053] In this embodiment, the connecting pipeline 3 includes an input pipeline 31 connected to the liquid storage container 2 and an output pipeline 33 connected to the crucible body 1. A preheating pipeline 32 connects the input pipeline 31 and the output pipeline 33. The preheating pipeline 32 is equipped with a surrounding induction coil as a heating element. The preheating pipeline can be made of graphite, but other high-temperature resistant metal pipelines are also acceptable. The pipeline is heated by eddy currents generated by the induction heating coil, thereby achieving the preheating purpose. Each pipeline can be mechanically connected to the corresponding vessel (e.g., through threads or appropriate interference fits, and sealed with metal gaskets or other sealing components).

[0054] Furthermore, the output end of the connecting pipe enters the crucible assembly from above the opening of the crucible assembly and can extend further below its liquid surface to reduce the impact of molten liquid droplets on the liquid inside the crucible assembly; the connecting pipe can also connect to the internal space of the crucible assembly from the upper side of the crucible assembly; the liquid level of the external target material source is basically flush with the maximum height of the high-level pipe 34 of the connecting pipe; the liquid level of the preheating pipe 32 is preferably lower than the liquid level of the input end and / or output end of the connecting pipe, so as to fully preheat the lower temperature evaporation solution input in the input pipe.

[0055] Furthermore, a liquid level control module 21 is set up, which is configured as an ultrasonic liquid level sensor. Based on the sensor, the start and stop of the wire feeding motor are controlled to feed the wire. By setting the wire feeding speed, the liquid level in the storage container is controlled.

[0056] Because of the preheating pipe 32 and the online wire feeding assembly, continuous wire feeding is possible, ensuring that molten vapor deposition solution is always present inside the storage container. This allows for continuous delivery of the vapor deposition solution and increases the length of the substrate to be vapor-deposited. Since continuous wire feeding is used, the volumes of the storage container 2 and the crucible body 1 can be appropriately reduced, increasing work efficiency. Furthermore, by controlling the height of the storage container 2 to be basically the same as or not higher than that of the high-level pipe 34, the molten liquid in the high-level pipe 34, after being heated to a higher temperature by the preheating pipe 32, expands in volume (in conjunction with the evaporation gas generated by the molten liquid), thus generating a pushing effect. This facilitates the flow of the high-temperature molten liquid through the high-level pipe 34, thereby acting as a barrier. The diameter D2 of the high-level pipe 34 is smaller than the diameter D1 of the output pipe 33 connected to it, which amplifies the pushing effect; preferably, D2 = 0.2-0.5D1.

[0057] In this embodiment, the liquid storage container 2 can also be further configured as a crucible and heated by induction heating. The material input into the liquid storage container 2 is continuously fed into the vapor-deposited metal wire through the wire feeding assembly. The wire feeding assembly structure is an existing conventional device (such as the wire feeding structure in patent number CN209602628U). Other controllable feeding structures, such as screw feeding and conveyor feeding equipment, are used to transport granular or powdery metal materials.

[0058] Further reference Figure 3 The main difference is:

[0059] A hot overflow zone is provided, which is formed at the output end of the preheating zone, that is, a raised high-level pipe 34 is provided. The height difference between the bottom of its inner wall and the liquid level of the liquid storage container 2 is H (H≤10mm), thereby forming a barrier for the low-temperature molten liquid. This allows the high-temperature molten liquid or its vapor / condensate after passing through the preheating zone to overflow into the crucible assembly through the pipe of the hot overflow zone, thereby playing the role of screening higher-temperature molten fluid.

[0060] The diameter of the high-level pipe 34 corresponding to the heat overflow zone is 0.1-0.5 times the inner diameter of the pipe connected to it (such as the output pipe 33) to amplify the volume expansion caused by the temperature rise, making it easier for the high-temperature molten liquid to flow.

[0061] Furthermore, at this point, the liquid level control method of the target material source is to control the wire feeding amount so that the height difference between it and the hot overflow zone is within the range of -H-0mm; a negative value indicates that its height is not higher than the height of the hot overflow zone pipe (lower inner wall), thereby making the connecting pipe form a flow barrier for the melt, and relatively low temperature fluids are not easy to pass through this area.

[0062] The value of the height difference H should be selected by taking into account the change in molten liquid density caused by temperature rise, pipe diameter, accuracy of liquid level control, and vacuum degree. It should generally not exceed 10 mm, and preferably be 3-8 mm.

[0063] In this application, the structures and connections not described in detail are all prior art, and their structures and principles are well known, so they will not be described in detail here.

[0064] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0065] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0066] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A continuous vapor deposition method, characterized in that, The method includes: An evaporator is provided for containing and melting the vapor deposition target material added in one step and forming vapor, with the vapor deposition temperature set to T0; It provides an external target material source, which can continuously supply molten target material liquid with a temperature T1 not lower than the melting point of the target material; A connecting pipe is provided to form a communicating vessel structure with an external target material source, and the maximum liquid level in the connecting pipe is controlled to be higher than the liquid level in the evaporator, so as to form a filling of the external target material molten liquid in the connecting pipe, thereby providing a target material input channel to the evaporator. A preheating zone is set in the connecting pipe to heat the supplemented target material to temperature T2; the pipe corresponding to the maximum liquid level in the connecting pipe is set at the output end of the preheating zone. Control the input liquid level of the external target material source to ensure a stable liquid level in the crucible assembly; A hot overflow zone is provided, which is located at the output end of the preheating zone and is controlled to be higher than the liquid level of the target material source. The height difference is H, forming a barrier for the low-temperature molten liquid, so that the high-temperature molten liquid or its vapor and condensate after passing through the preheating zone can pass through the pipeline of the hot overflow zone, which plays the role of screening higher-temperature molten fluid. The liquid level of the target material source is controlled by controlling the wire feeding amount so that the height difference between the bottom of the inner wall of the high-level pipeline and the height of the hot overflow zone is within the range of -H-0mm; wherein, H≤10mm.

2. The continuous vapor deposition method as described in claim 1, characterized in that, Temperature T2 is close to the vapor deposition temperature T0.

3. The continuous vapor deposition method as described in claim 1, characterized in that, The output end of the connecting pipe enters the crucible assembly from above the opening of the crucible assembly, or connects to its internal space from the upper side of the evaporator.

4. The continuous vapor deposition method according to any one of claims 1-3, characterized in that, The liquid level in the preheating zone is lower than the liquid level at the inlet and / or outlet of the connecting pipe.

5. An apparatus for continuous vapor deposition, comprising: The evaporation chamber provides a vacuum negative pressure environment for vapor deposition; The conveying mechanism provides guide rollers for transporting the substrate material to be processed and allows for tension adjustment; Its characteristic is that it further includes: An evaporator, with a first heating component externally provided for heating the target material inside the evaporator; A feeding device is used to continuously supply an external target material source, which contains molten vapor deposition solution; The connecting pipeline is connected to the feeding device to form a communicating vessel structure. The maximum liquid level in the connecting pipeline is higher than the liquid level in the evaporator. A preheating pipeline is set on the connecting pipeline to form a preheating zone to further heat the replenished molten target material. The connecting pipeline includes an input pipeline connected to the liquid storage container and an output pipeline connected to the evaporator. The preheating pipeline is connected between the input pipeline and the output pipeline. The high-level pipeline is set at the output end of the preheating pipeline and extends into the evaporator. A hot overflow zone is provided, which is located at the output end of the preheating zone and is controlled to be higher than the liquid level of the target material source. The height difference is H, forming a barrier for the low-temperature molten liquid, so that the high-temperature molten liquid or its vapor and condensate after passing through the preheating zone can pass through the pipeline of the hot overflow zone, which plays the role of screening higher-temperature molten fluid. The liquid level of the target material source is controlled by controlling the wire feeding amount so that the height difference between the bottom of the inner wall of the high-level pipeline and the height of the hot overflow zone is within the range of -H-0mm; wherein, H≤10mm.

6. The apparatus for continuous vapor deposition as described in claim 5, characterized in that, The feeding device includes a liquid storage container and a feeding assembly for replenishing the target material. A second heating assembly is installed outside the liquid storage container for heating and melting the target material raw material.

7. The apparatus for continuous vapor deposition as described in claim 5, characterized in that, The diameter of the elevated pipeline is 0.1-0.5 times the inner diameter of the pipeline it connects to.

8. The apparatus for continuous vapor deposition as described in any one of claims 5-7, characterized in that, The output end of the high-level pipeline extends to below the liquid surface inside the crucible body.

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