Evaporation source and evaporation device

Abstract

The utility model relates to the technical field of vacuum coating equipment, and discloses an evaporation source and an evaporation device, the evaporation source comprises a loose part and a compact part, the surface of the loose part comprises a non-evaporation surface and an evaporation surface used for bearing evaporation materials, the compact part is coated outside the non-evaporation surface, or the compact part is coated outside at least one surface of the loose part, and the non-evaporation surface is coated outside the evaporation surface. The uncoated part on the surface of the loose part forms an evaporation surface; the structure of the compact part can prevent the evaporation material carried in the evaporation source from flowing out; the large specific surface area of the loose part increases the contact area between the evaporation source and the evaporation material, so that heat generated after the evaporation source is powered on can be more widely dispersed into the evaporation material, the structure of the loose part can help gas generated by evaporation of the evaporation material to be discharged more quickly, the heating uniformity of the evaporation source is improved, and the evaporation efficiency is improved. The sputtering phenomenon of the evaporation material is reduced, the utilization rate of the evaporation material is improved, and the preparation cost of the thin film is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of vacuum coating equipment, in particular to an evaporation source and a evaporation device. Background Art

[0002] Vacuum evaporation is a widely used thin film preparation technology that plays an important role in many fields such as optics, semiconductors, display panels, and new energy. During the vacuum evaporation process, the evaporation source (such as an evaporation boat, an evaporation dish, a crucible, etc.) is placed in a vacuum environment, and the evaporation material (such as metals, organic matter, etc., which can be liquid or solid) carried inside the evaporation source is evaporated or sublimated into gaseous particles by precisely controlling the heating conditions, and then attached to the surface of the workpiece to be plated to form a uniform and dense film.

[0003] The existing evaporation device uses an evaporation source with a resistance heating method. Its heating mechanism is to directly heat the evaporation material by generating heat after it is powered on. Since the heat distribution of the resistance heating element is often subject to factors such as its geometric shape, material properties, and current density, the temperature distribution of the surface in contact with the evaporation source and the evaporation material after power is turned on is uneven, and the evaporation material may be locally overheated, resulting in splashing, resulting in low utilization of the evaporation material and high film preparation costs. Utility Model Content

[0004] The utility model discloses an evaporation source, which is used to solve the technical problem that the existing evaporation source adopting a resistance heating heating method has poor heating uniformity and leads to high film preparation cost.

[0005] The first aspect of the utility model provides an evaporation source, comprising a loose part and a dense part;

[0006] The surface of the loose portion includes a non-evaporation surface and an evaporation surface for carrying the evaporation material;

[0007] The dense portion is coated outside the non-evaporation surface.

[0008] Optionally, the loose portion and the dense portion are integrally formed.

[0009] Optionally, an evaporation groove for containing the evaporation material is provided on the loose portion, and the evaporation surface is arranged around the evaporation groove.

[0010] Optionally, the evaporation surface is a concave structure whose surface is lower than the surface of the dense part.

[0011] Optionally, two mounting positions for cooperating with electrodes of a vapor deposition device are formed on opposite sides of the dense portion.

[0012] Optionally, the loose part and the dense part are made of the same material.

[0013] Optionally, the dense portion is made of silicon carbide.

[0014] Optionally, the loose portion is a mesh foam structure.

[0015] The second aspect of the utility model provides an evaporation source, comprising a loose part and a dense part;

[0016] The dense part is coated on at least one surface of the loose part;

[0017] The uncovered portion of the surface of the loose portion forms an evaporation surface for carrying the evaporation material.

[0018] A third aspect of the utility model provides an evaporation device, comprising an evaporation source as described in any one of the above items.

[0019] It can be seen from the above technical solutions that the utility model has the following advantages:

[0020] The utility model provides an evaporation source and an evaporation device, wherein the evaporation source includes a loose part and a dense part, the surface of the loose part includes a non-evaporation surface and an evaporation surface for carrying the evaporation material, the dense part is coated outside the non-evaporation surface, or the dense part is coated outside at least one surface of the loose part, and the uncoated part of the surface of the loose part forms the evaporation surface. In the utility model, the structure of the dense part can prevent the evaporation material carried in the evaporation source from flowing out; the larger specific surface area of ​​the loose part increases the contact area between the evaporation source and the evaporation material, so that the heat generated by the evaporation source after power is turned on can be more widely dispersed into the evaporation material, and when the local temperature of the loose part is too high, it may cause the evaporation material in the area to evaporate too quickly and generate a large amount of gas, and the gas that cannot be discharged in time will affect the heat transfer in the evaporation material, and the structure of the loose part can make the gas be discharged faster, thereby improving the uniformity of heating of the evaporation source, reducing the splashing phenomenon of the evaporation material, improving the utilization rate of the evaporation material, and reducing the preparation cost of the film. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 This is a schematic diagram of the structure of an evaporation source provided in an embodiment of the utility model;

[0023] Figure 2 The figure is a schematic diagram of the cross-sectional structure of an evaporation source provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0024] The utility model discloses an evaporation source and an evaporation device, which solves the technical problem that the heating temperature uniformity of the evaporation source using the existing resistance heating method is poor, resulting in high film preparation cost.

[0025] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0027] Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0028] See also Figures 1 to 2 , an evaporation source provided in the first embodiment of the utility model comprises a loose part 1 and a dense part 2;

[0029] The surface of the loose portion 1 includes a non-evaporation surface and an evaporation surface for carrying the evaporation material;

[0030] The dense portion 2 covers the non-evaporation surface of the loose portion 1 .

[0031] It should be noted that the loose portion 1 is a solid part with a loose structure. The loose structure refers to a structure containing a large number of ordered or disordered pores, such as an irregular honeycomb structure, an ordered porous structure, etc. It is preferably a reticular foam structure. The pores of the reticular foam structure are connected in a network, and there are no closed or nearly closed holes. This structural feature provides a larger specific surface area and higher pore connectivity, which is conducive to the rapid penetration, flow and exchange of the evaporation material, making the heating more uniform, and the relatively open structure makes it difficult for the evaporation material to remain in the loose portion 1 after the evaporation is completed, thereby improving the utilization rate of the evaporation material and reducing the difficulty of cleaning the evaporation source. The structural parameters of the loose portion 1, such as the porosity and pore size range, are not specifically limited, and can be adjusted according to factors such as the characteristics of the material used, the manufacturing process, and actual needs, and combined with a limited number of experiments.

[0032] The pores in the loose portion 1 give the loose portion 1 a larger specific surface area, increasing the contact area between the evaporation source and the liquid evaporation material, so that the heat generated by the evaporation source after power is turned on can be more widely dispersed into the evaporation material; when the local temperature of the loose portion 1 is too high, the evaporation material in this area may evaporate too quickly and generate a large amount of gas to form bubbles. The bubbles that cannot be discharged in time will affect the heat transfer in the evaporation material, and the pores in the loose portion 1 provide an additional rising channel for the bubbles, which can discharge the gas faster; the capillary action of the pores in the loose portion 1 will prompt the liquid evaporation material to enter the gap between the bubbles and the pore wall, reduce the adhesion of the bubbles in the pores, and help the bubbles to leave the pores faster; in the pores in the loose portion 1, the liquid evaporation material is forced to flow through a tortuous and complex channel, which enhances the disturbance of the evaporation material, promotes the occurrence of convection, and makes the various parts of the liquid absorb heat more evenly, which can also help the bubbles to be discharged. The various features of the above-mentioned loose portion 1 improve the uniformity of heating of the evaporation source, improve the uniformity of heating of the evaporation source, reduce the splashing phenomenon of the evaporation material, improve the utilization rate of the evaporation material, and reduce the preparation cost of the thin film.

[0033] The dense part 2 is a solid part with a dense structure. The dense structure refers to a structure in which the units constituting the structure are arranged closely, have no gaps between each other, or have small gaps and are not interconnected. The dense part 2 can be coated on the outside of the loose part 1 in a layered, shell-like form; the loose part 1 should have at least one evaporation surface for carrying the evaporation material, and the dense part 2 is wrapped around the non-evaporation surface of the loose part 1. The evaporation material added to the evaporation source is received by the pores of the loose part 1 and diffuses rapidly in the loose part along the pores. The evaporated gaseous evaporation material is released from the evaporation surface; the liquid level of the evaporation material should not exceed the highest position of the dense part 2 to prevent the evaporation material from flowing out through the pores in the loose part 1.

[0034] Although the loose part 1 and the dense part 2 are made of different materials, they can be made of the same material or different materials; the evaporation source needs to be heated to a certain temperature to evaporate the evaporation material, so the loose part 1 and the dense part 2 should be made of heat-resistant materials with a melting point much higher than the heating temperature and can remain stable in a long-term high-temperature environment; in addition, since the evaporation source provided by the utility model adopts a resistance heating heating method, in order for the evaporation source to generate heat after power is turned on, at least the dense part 2 must be made of a conductive material, and the loose part 1 can be made of a material with good thermal conductivity, and the dense part 2 generates heat to heat the evaporation material carried by the loose part 1; the loose part 1 and the dense part 2 can also be made of the same or different conductive materials, and both the loose part 1 and the dense part 2 can generate heat after power is turned on, thereby improving the heating efficiency.

[0035] Furthermore, there is a difference between the contact area between the dense part 2 and the evaporation material and the contact area between the loose part 1 and the evaporation material, resulting in poor uniformity in heating at the interface between the dense part 2 and the loose part 1. Therefore, the loose part 1 and the dense part 2 can respectively use two conductive materials with different resistivities. For example, when the contact area between the dense part 2 and the evaporation material is smaller than the contact area between the loose part 1 and the evaporation material, the resistivity of the conductive material used in the loose part 1 is greater than the resistivity of the conductive material used in the dense part 2. A person skilled in the art can estimate the contact area between the loose part and the evaporation material by the size, shape and specific surface area of ​​the loose part, estimate the contact area between the dense part and the evaporation material by the porosity and pore size of the loose part, and the size and shape of the dense part, and obtain the best conductivity combination through a limited number of experiments.

[0036] Specifically, the dense portion 2 is preferably made of silicon carbide, which has good electrical conductivity and heat resistance, high heating efficiency, can reach the heating temperature more quickly, and is not easily deformed even when exposed to a high temperature environment for a long time; in a more specific embodiment, the dense portion 2 is silicon carbide with a dense structure, and the loose portion 1 is a silicon carbide material with a loose mesh material.

[0037] In a preferred embodiment, the loose portion 1 and the dense portion 2 are integrally formed.

[0038] It is understandable that during the evaporation process, the evaporation source needs to be precisely fixed at a specific position in the evaporation device to ensure that the evaporation source remains stable throughout the evaporation process and does not move due to its own gravity, shaking caused by the evaporation of the internal evaporation material, or external disturbances, so as to ensure the uniformity of the coating thickness, precise pattern alignment and repeatability of the evaporation process; therefore, if the loose part 1 and the dense part 2 are assembled separately, it is difficult to ensure the stability of the connection between the loose part 1 and the dense part 2 under a high temperature environment; in this preferred embodiment, in order to reduce the difficulty of making and producing the one-piece evaporation source, the loose part 1 and the dense part 2 are preferably made of the same material; the one-piece molding of the loose part 1 and the dense part 2 can be achieved by double injection molding, 3D printing, directional solidification and other technologies, and the specific molding technology can be selected according to the type of material used and the target structural morphology, and is not specifically limited here.

[0039] In a preferred embodiment, an evaporation tank 3 for containing evaporation materials is provided on the loose portion 1, and an evaporation surface is arranged around the evaporation tank 3, that is, the bottom surface and all side surfaces of the evaporation tank 3 are loose structures.

[0040] or,

[0041] The evaporation surface is a concave structure whose surface is lower than the surface of the dense part 2, that is, the bottom surface of the concave structure is a loose structure.

[0042] It can be understood that the evaporation groove 3 or the recessed structure formed by the evaporation surface of the loose part 1 enables the loose part 1 to carry more liquid evaporation materials, and can also carry evaporation materials that are originally solid; when the evaporation process is carried out, the solid evaporation material filaments are fed into the evaporation groove 3 or the recessed structure from one side of the evaporation source and are heated, melted and evaporated.

[0043] Furthermore, part or all of the side surfaces of the evaporation tank 3 are inclined toward the outside of the tank relative to the bottom surface of the evaporation tank. The inclined side surfaces can help the evaporation material flow to the bottom of the tank, reduce the adhesion or residue of the evaporation material on the inner side surface of the tank, and reduce the difficulty of cleaning caused by the right angle or acute angle between the side surface and the bottom surface; further, the side surface of the evaporation tank 3 can be connected to the bottom surface at a curved surface.

[0044] In a preferred embodiment, since most evaporation devices use a clamping device that uses a clamp as an electrode to fix the evaporation source, in order to ensure the uniformity of the force applied by the clamp and the heating of the evaporation source when it is powered on, two mounting positions for cooperating with the electrodes of the evaporation device are formed on opposite sides of the dense portion 2.

[0045] Furthermore, before the evaporation source reaches the operating temperature, the resistance between the two mounting positions should be less than 1Ω. According to Joule's law, under the same voltage, a smaller resistance can generate more heat energy in the same time, so that the evaporation source heats up to the operating temperature faster and improves the heating efficiency of the evaporation source.

[0046] The utility model provides an evaporation source in the second embodiment, comprising a loose part and a dense part;

[0047] The dense part covers at least one surface of the loose part;

[0048] The uncovered portion of the surface of the porous portion forms an evaporation surface for supporting the evaporation material.

[0049] It can be understood that the loose part is the entity part with a loose structure, and the dense part is the entity part with a dense structure. The dense part can be coated on the outside of the loose part in the form of layers, shells, etc. Technical personnel in the relevant field can clearly understand that for the convenience and conciseness of description, the specific features of the loose structure and dense structure described in this embodiment can refer to the corresponding descriptions in the aforementioned embodiments, and will not be repeated here.

[0050] The pores in the loose part give the loose part a larger specific surface area, increasing the contact area between the evaporation source and the liquid evaporation material, so that the heat generated by the evaporation source after power is turned on can be more widely dispersed into the evaporation material; when the local temperature of the loose part is too high, the evaporation material in this area may evaporate too quickly and generate a large amount of gas to form bubbles. The bubbles that cannot be discharged in time will affect the heat transfer in the evaporation material, and the pores in the loose part provide an additional rising channel for the bubbles, which can discharge the gas faster; the capillary action of the pores in the loose part will prompt the liquid evaporation material to enter the gap between the bubbles and the pore wall, reduce the adhesion of the bubbles in the pores, and help the bubbles to leave the pores faster; in the pores in the loose part, the liquid evaporation material is forced to flow through tortuous and complex channels, which enhances the disturbance of the evaporation material, promotes the occurrence of convection, makes the various parts of the liquid absorb heat more evenly, and also helps the bubbles to be discharged. The above-mentioned characteristics of the loose part improve the uniformity of heating of the evaporation source, improve the uniformity of heating of the evaporation source, reduce the splashing phenomenon of the evaporation material, improve the utilization rate of the evaporation material, and reduce the preparation cost of the film.

[0051] The dense part is coated on at least one surface of the loose part, but does not completely cover the entire surface of the loose part. The uncovered part of the surface of the loose part forms an evaporation surface for carrying the evaporation material. The evaporation material added to the evaporation source is received by the pores of the loose part and rapidly diffuses in the loose part along the pores. The evaporated gaseous evaporation material is released from the evaporation surface. The coating of the dense part can prevent the evaporation material from flowing out through the pores in the loose part. At the same time, the liquid level of the evaporation material should not exceed the highest position of the dense part.

[0052] Although the loose part and the dense part are made of different materials, they can be made of the same material or different materials; the evaporation source needs to be heated to a certain temperature to evaporate the evaporation material, so the loose part and the dense part should be made of heat-resistant materials with a melting point much higher than the heating temperature and capable of remaining stable in a long-term high-temperature environment; in addition, since the evaporation source provided by the utility model adopts a resistance heating heating method, in order for the evaporation source to generate heat after power is turned on, at least the dense part must be made of a conductive material, and the loose part can be made of a material with good thermal conductivity, and the evaporation material carried by the loose part is heated by the heat generated by the dense part; the loose part and the dense part can also be made of the same or different conductive materials, and both the loose part and the dense part can generate heat after power is turned on, thereby improving the heating efficiency.

[0053] Furthermore, there is a difference between the contact area between the dense part and the vapor deposition material and the contact area between the loose part and the vapor deposition material, resulting in poor heating uniformity at the junction of the dense part and the loose part. Therefore, the loose part and the dense part can respectively use two conductive materials with different resistivities. For example, when the contact area between the dense part and the vapor deposition material is smaller than the contact area between the loose part and the vapor deposition material, the resistivity of the conductive material used in the loose part is greater than the resistivity of the conductive material used in the dense part. A technician in this field can estimate the contact area between the loose part and the vapor deposition material by the size, shape and specific surface area of ​​the loose part, estimate the contact area between the dense part and the vapor deposition material by the porosity and pore size of the loose part, and the size and shape of the dense part, and obtain the optimal conductivity combination after a limited number of experiments.

[0054] Specifically, the dense part is preferably made of silicon carbide, which has good conductivity and heat resistance, high heating efficiency, can reach the heating temperature more quickly, and is not easily deformed even when exposed to high temperature for a long time. In a more specific embodiment, the dense part is silicon carbide with a dense structure, and the loose part is a silicon carbide material with a loose mesh material.

[0055] In a preferred embodiment, the loose part and the dense part are integrally formed.

[0056] It is understandable that during the evaporation process, the evaporation source needs to be precisely fixed at a specific position in the evaporation device to ensure that the evaporation source remains stable throughout the evaporation process and does not move due to its own gravity, shaking caused by the evaporation of the internal evaporation material, or external disturbances, so as to ensure the uniformity of the coating thickness, precise pattern alignment and repeatability of the evaporation process; therefore, if the loose part and the dense part are assembled separately, it is difficult to ensure the stability of the connection between the loose part and the dense part under a high temperature environment; in this preferred embodiment, in order to reduce the difficulty of making and producing the one-piece evaporation source, the loose part and the dense part are preferably made of the same material; the one-piece molding of the loose part and the dense part can be achieved by double injection molding, 3D printing, directional solidification and other technologies, and the specific molding technology can be selected according to the type of material used and the target structural morphology, and is not specifically limited here.

[0057] In a preferred embodiment, an evaporation tank for containing evaporation materials is provided on the loose part, and the evaporation surface is arranged around the evaporation tank, that is, the bottom surface and all side surfaces of the evaporation tank are loose structures.

[0058] or,

[0059] The evaporation surface is a concave structure whose surface is lower than the surface of the dense part, that is, the bottom surface of the concave structure is a loose structure.

[0060] It can be understood that the evaporation groove or the recessed structure formed by the evaporation surface of the loose part enables the loose part to carry more liquid evaporation materials, and can also carry evaporation materials that are originally solid; when performing evaporation processing, the solid evaporation material filaments are fed into the evaporation groove or the recessed structure from one side of the evaporation source and are heated, melted and evaporated.

[0061] Furthermore, part or all of the side surfaces of the evaporation tank are inclined toward the outside of the tank relative to the bottom surface of the evaporation tank. The inclined side surfaces can help the evaporation material flow to the bottom of the tank, reduce the adhesion or residue of the evaporation material on the inner side surfaces of the tank, and reduce the difficulty of cleaning caused by the right angle or acute angle between the side surfaces and the bottom surface; further, the side surfaces of the evaporation tank can be curved at the connection with the bottom surface.

[0062] In a preferred embodiment, since most evaporation devices use the clamping device of the clamping jaws as electrodes to fix the evaporation source, in order to ensure the uniformity of the force applied by the clamping jaws and the heating of the evaporation source when it is powered on, two mounting positions for cooperating with the electrodes of the evaporation device are formed on opposite sides of the dense portion.

[0063] Furthermore, before the evaporation source reaches the operating temperature, the resistance between the two mounting positions should be less than 1Ω. According to Joule's law, under the same voltage, a smaller resistance can generate more heat energy in the same time, so that the evaporation source heats up to the operating temperature faster and improves the heating efficiency of the evaporation source.

[0064] A third embodiment of the present invention provides an evaporation device, comprising an evaporation source as described in any of the above embodiments.

[0065] It can be understood that the evaporation device also includes at least two electrodes, which are connected to the evaporation source to supply power to the evaporation source. Specifically, the two electrodes can be connected to the evaporation source respectively through two mounting positions on the evaporation source; the evaporation device should also include a fixing device for fixing the evaporation source, such as a clamping device that uses a clamp as an electrode to fix the evaporation source.

[0066] The above is a detailed introduction to an evaporation source and an evaporation device provided by the present invention. For a person skilled in the art, according to the idea of ​​the embodiments of the present invention, there may be changes in the specific implementation method and the scope of application. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. An evaporation source, characterized in that: Includes loose part and dense part; The surface of the loose portion includes a non-evaporation surface and an evaporation surface for carrying the evaporation material; The dense portion is coated outside the non-evaporation surface.

2. The evaporation source according to claim 1, characterized in that: The loose portion and the dense portion are integrally formed.

3. The evaporation source according to claim 1, characterized in that: The loose portion is provided with an evaporation groove for containing the evaporation material, and the evaporation surface is arranged around the evaporation groove.

4. The evaporation source according to claim 1, characterized in that: The evaporation surface is a concave structure whose surface is lower than the surface of the dense part.

5. The evaporation source according to claim 1, characterized in that: Two mounting positions for cooperating with electrodes of a vapor deposition device are formed on opposite sides of the compact portion.

6. The evaporation source according to claim 1, characterized in that: The loose part and the dense part are made of the same material.

7. The evaporation source according to claim 1 or 6, characterized in that: The dense part is made of silicon carbide.

8. The evaporation source according to claim 1, characterized in that: The loose part is a mesh foam structure.

9. An evaporation source, characterized in that: Includes loose part and dense part; The dense part is coated on at least one surface of the loose part; The uncovered portion of the surface of the loose portion forms an evaporation surface for carrying the evaporation material.

10. A vapor deposition device, characterized in that: The method comprises the evaporation source according to any one of claims 1 to 9.

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