Height-adjustable crucible table structure

Abstract

The utility model discloses a crucible table structure with adjustable height, which relates to the technical field of vacuum coating, and comprises a crucible table and a supporting piece, the supporting piece is connected with the crucible table through a lifting structure, the supporting piece can move along the axial direction of the crucible table in a positioning way, and the supporting piece can move axially relative to the crucible table when the liquid level in a crucible descends; according to the utility model, the lifting structure drives the supporting piece to move upwards relative to the crucible table and drives the crucible to move upwards, so that the distance between the liquid level of a coating material and the substrate is kept constant, and the thickness of a film from the liquid level of the coating material to the surface of the substrate is kept at a constant value, so that the uniformity of coating and film forming on the substrate is ensured; the optical performance of a film on the substrate is improved, the coating quality of the substrate is improved, the lifting speed of the supporting piece can be flexibly adjusted according to the liquid level descending speed of different coating materials, the coating efficiency is improved, and the device is simple in structure, low in cost and convenient to install, implement, popularize and use.

Description

Technical Field

[0001] The utility model relates to the technical field of vacuum coating, in particular to a crucible table structure with adjustable height. Background Art

[0002] During the vacuum coating process, the coating material is heated by an electron beam and evaporated onto the surface of the substrate. The coating material is placed in a crucible. Patent Application No. 201810668967.5 discloses an adjustable structure for the evaporation source position, including a crucible table and an electron gun arranged in a vacuum coating chamber. The crucible table is used to carry the crucible containing the coating material, and the electron gun is used to evaporate the coating material contained in the crucible. The crucible table and the electron gun are installed on a reference adjustment base, and a rotation driving device is arranged on the reference adjustment base. The rotation driving device adjusts the evaporation positions of the crucible table and the electron gun in the vacuum coating chamber by driving the reference adjustment base to rotate. The adjustment structure in this technical solution realizes the adjustment of the evaporation source position in the vacuum coating chamber, can flexibly adjust the process according to the coating product, and achieves a better coating effect; it can realize the switching of the crucible points, especially facilitating the sequential evaporation of multiple coating materials and improving the coating efficiency. However, under the heating of the electron beam, the surface layer of the coating material melts to form a liquid surface. As the coating material is evaporated, the liquid surface of the coating material gradually drops, and the distance from the substrate gradually increases, resulting in a decrease in the film thickness reaching the substrate surface. For a thin film system, the film thickness varies, and the difference may be as large as 100 - 200 nm. It is difficult to correct this error with relatively regular tooling values, resulting in a relatively large impact on the optical properties of the thin film. Therefore, the utility model discloses a crucible table structure with adjustable height to solve the above problems. Summary of the Utility Model

[0003] Based on this, in order to solve the above technical problems, it is necessary to provide a crucible table structure with adjustable height. After the liquid surface on the surface of the coating material evaporates and drops, the lifting structure drives the support member to move upward relative to the crucible table, thereby driving the crucible to move upward, so that the liquid surface level on the surface of the coating material is maintained at a constant position, the distance between the liquid surface of the coating material and the substrate is kept constant, and the film thickness of the liquid surface of the coating material reaching the substrate surface is at a constant value, so as to ensure the uniformity of the film formation on the substrate, reduce the difference in the coating thickness on the substrate, facilitate the correction of the thickness error, improve the optical properties of the thin film on the substrate, and further improve the coating quality of the substrate. Moreover, it can flexibly adjust the lifting speed of the support member according to the liquid surface drop speed of different coating materials, improve the coating efficiency, and has a simple structure, low cost, is convenient for installation and implementation, and is easy to popularize and use.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0005] A crucible table structure with adjustable height, which includes a crucible table and a support member. The support member is connected to the crucible table through a lifting structure, and the support member can be axially positioned and moved along the crucible table. When the liquid level in the crucible drops, the support member can move axially relative to the crucible table.

[0006] As a preferred embodiment of the crucible table structure with adjustable height provided by the present utility model, both the crucible table and the support member are annular structures, and the outer diameter of the support member is the same as the outer diameter of the crucible table.

[0007] As a preferred embodiment of the crucible table structure with adjustable height provided by the present utility model, a plurality of circumferentially distributed crucible support points are fixed on the top surface of the support member.

[0008] As a preferred embodiment of the crucible table structure with adjustable height provided by the present utility model, when the coating material evaporates, the height of the support member rising axially relative to the crucible table per unit time is the same as the height of the liquid level drop in the crucible.

[0009] As a preferred embodiment of the crucible table structure with adjustable height provided by the present utility model, the lifting structure includes a disc, a spring and a locking member. A plurality of circumferentially distributed directional sliding grooves are provided on the crucible table. A disc is slidably connected in the directional sliding groove. A locking member is fixedly connected to the opening of the directional sliding groove. The disc and the locking member are connected by a spring.

[0010] As a preferred embodiment of the crucible table structure with adjustable height provided by the present utility model, a sleeve is fixedly connected to the inner wall of the directional sliding groove. The diameter of the sleeve is the same as the diameter of the disc, and the disc is slidably connected to the sleeve.

[0011] As a preferred embodiment of the crucible table structure with adjustable height provided by the present utility model, the locking member includes a threaded portion, a positioning portion and a rotating portion integrally provided from bottom to top. The threaded portion is threadedly connected to the inner wall of the upper port of the directional sliding groove, and the positioning portion is positioned and fitted with the upper surface of the crucible table.

[0012] As a preferred embodiment of the crucible table structure with adjustable height provided by the present utility model, a positioning through hole is provided on the locking member. A positioning rod is fixedly connected between the disc and the support member, and the positioning rod is slidably connected to the positioning through hole.

[0013] As a preferred embodiment of the crucible table structure with adjustable height provided by the present utility model, a circumferentially distributed support table is fixedly connected to the top surface of the crucible table, and the top surface of the support table is higher than the top surface of the locking member.

[0014] As a preferred embodiment of the height-adjustable crucible table structure provided by the present utility model, a boss is provided on the bottom top surface of the crucible table, and a plurality of through holes are provided around the boss.

[0015] Compared with the prior art, the present utility model has the following beneficial effects:

[0016] For the height-adjustable crucible table structure provided by the present utility model, after the liquid level on the surface of the coating material evaporates and drops, the lifting structure drives the support member to move upward relative to the crucible table, thereby driving the crucible to move upward, so that the liquid level on the surface of the coating material remains at a constant position, the distance between the liquid level of the coating material and the substrate remains constant, and the film thickness of the coating material reaching the surface of the substrate is at a constant value, so as to ensure the uniformity of the film formed on the substrate, reduce the difference in the coating thickness on the substrate, facilitate the correction of the thickness error, improve the optical performance of the film on the substrate, and further improve the coating quality of the substrate. Moreover, it can flexibly adjust the lifting speed of the support member according to the liquid level drop speed of different coating materials, improve the coating efficiency, and has a simple structure, low cost, is convenient for installation and implementation, and is convenient for popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the solutions in the present utility model, the following will briefly introduce the drawings required for use in the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a three-dimensional schematic diagram of the overall structure of the height-adjustable crucible table structure provided by the present utility model;

[0019] Figure 2 It is a cross-sectional schematic diagram of the overall structure of the height-adjustable crucible table structure provided by the present utility model;

[0020] Figure 3 It is a connection schematic diagram of the support member and the lifting structure of the height-adjustable crucible table structure provided by the present utility model;

[0021] Figure 4 It is an exploded schematic diagram of the lifting structure of the height-adjustable crucible table structure provided by the present utility model;

[0022] Figure 5 It is a schematic diagram of the locking member structure of the height-adjustable crucible table structure provided by the present utility model.

[0023] The reference numerals in the drawings are explained as follows:

[0024] 1. Crucible table; 2. Support member; 3. Crucible support point; 4. Support table; 5. Boss; 6. Through hole; 7. Lifting structure; 8. Disc; 9. Spring; 10. Locking member; 101. Threaded portion; 102. Positioning portion; 103. Rotating portion; 104. Positioning through hole; 11. Orienting chute; 12. Sleeve; 13. Positioning rod. Detailed implementation manner

[0025] In order to enable those skilled in the art of the present technology to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0026] As described in the background art, under electron beam heating, the surface layer of the coating material melts to form a liquid surface. As the coating material is evaporated, the liquid surface of the coating material gradually descends, and the distance from the substrate gradually increases, resulting in a decrease in the thickness of the thin film reaching the substrate surface. For a thin film system, the film thickness varies, and the difference may be as large as 100 - 200 nm. It is very difficult to correct this error with relatively regular tooling values, resulting in a relatively large impact on the optical properties of the thin film.

[0027] To solve this technical problem, the present utility model provides a crucible table structure with adjustable height, which is applied to the field of vacuum coating.

[0028] Specifically, please refer to Figures 1-5 , the crucible table structure with adjustable height specifically includes a crucible table 1 and a support member 2. The support member 2 is connected to the crucible table 1 through a lifting structure 7, and the support member 2 can axially position and move along the crucible table 1. When the liquid level in the crucible drops, the support member 2 can axially move relative to the crucible table 1.

[0029] The height-adjustable crucible table structure provided by the present utility model, after the liquid level on the surface of the coating material evaporates and drops, the lifting structure 7 drives the support member 2 to move upward relative to the crucible table 1, thereby driving the crucible to move upward, so that the liquid level on the surface of the coating material remains at a constant position, the distance between the liquid level of the coating material and the substrate remains constant, and the film thickness at which the liquid level of the coating material reaches the surface of the substrate is at a constant value, so as to ensure the uniformity of the film formation on the substrate, reduce the difference in the coating thickness on the substrate, facilitate the correction of the thickness error, improve the optical performance of the film on the substrate, and further improve the coating quality of the substrate. Moreover, it can flexibly adjust the lifting speed of the support member 2 according to the liquid level drop speed of different coating materials, improve the coating efficiency, and has a simple structure, low cost, is convenient for installation and implementation, and is easy to promote and use.

[0030] In order to enable those skilled in the art to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the drawings.

[0031] It should be noted that, without conflict, the embodiments in the present utility model and the features and technical solutions in the embodiments can be combined with each other.

[0032] It should be noted that similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0033] Please refer to Figures 1-5 , which provides a height-adjustable crucible table structure, which includes a crucible table 1 and a support member 2. Both the crucible table 1 and the support member 2 are annular structures, and the outer diameter of the support member 2 is the same as the outer diameter of the crucible table 1. A plurality of circumferentially distributed crucible support points 3 are fixed on the top surface of the support member 2. The crucible for containing the coating material is placed on the support member 2, and the support member 2 is used to support the crucible. The support member 2 is connected to the crucible table 1 through a lifting structure 7 and the support member 2 can axially position and move along the crucible table 1. When the liquid level in the crucible drops, the support member 2 can axially move relative to the crucible table 1. During the coating process, the liquid level on the surface of the coating material drops, and the lifting structure 7 drives the support member 2 to move upward to perform an upward compensation for the drop of the liquid level of the coating material, and always keep the liquid level of the coating material at a constant position to ensure the uniformity of the film formation.

[0034] In order to ensure that the liquid level of the coating material remains at a constant position, when the coating material evaporates, the unit upward height of the support member 2 relative to the crucible table 1 in the axial direction is the same as the drop height of the liquid level in the crucible, and the unit is selected as seconds.

[0035] The top surface of the crucible table 1 is fixedly connected with circumferentially distributed support platforms 4. The top surface of the support platform 4 is higher than the top surface of the locking member 10. The support platform 4 supports the support member 2. A boss 5 is provided on the bottom top surface of the crucible table 1, and a plurality of through holes 6 are provided around the boss 5. A cooling system is installed at the bottom of the crucible table 1.

[0036] Install the structure of the crucible table 1 in the vacuum coating machine, and an electron beam evaporation system is arranged on one side of the crucible table 1. A heating system is arranged on the side wall of the vacuum coating machine. Other structures of the vacuum coating machine are all existing conventional technologies and will not be described separately here.

[0037] Further optimize the height-adjustable crucible table structure provided in Embodiment 1. Specifically, as Figures 2-4 shown, the lifting structure 7 includes a disc 8, a spring 9 and a locking member 10. Six circumferentially distributed directional sliding grooves 11 are provided on the crucible table. A disc 8 is slidably connected in the directional sliding groove 11. A locking member 10 is fixedly connected at the opening of the directional sliding groove. The disc 8 and the locking member 10 are connected by a spring 9, and the support member 2 is elastically connected to the crucible table 1. After the crucible carrying the coating material is placed on the support member 2, the spring 9 is compressed so that the support member 2 is at the lowest position. According to Hooke's law, within the elastic limit, the elastic force of the spring 9 is proportional to the elongation (or compression) of the spring 9. Adjust the spring constant of the spring 9 so that within a unit time, the recovery length of the spring 9 is consistent with the drop height of the liquid level on the upper surface of the coating material in the crucible, so as to achieve the upward compensation of the liquid level of the coating material in the crucible.

[0038] The inner wall of the directional sliding groove 11 is fixedly connected with a sleeve 12. The diameter of the sleeve 12 is the same as the diameter of the disc 8. The disc 8 is slidably connected with the sleeve 12. The sleeve 12 is made of stainless steel and is a seamless steel pipe to reduce friction.

[0039] Further optimize the height-adjustable crucible table structure provided in Embodiment 2. Specifically, as Figure 2 、 5 shown, the locking member 10 includes a threaded portion 101, a positioning portion 102 and a rotating portion 103 which are integrally arranged from bottom to top. The threaded portion 101 is threadedly connected with the inner wall of the upper port of the directional sliding groove 11. The positioning portion 102 is positioned and attached to the upper surface of the crucible table 1. The positioning portion 102 is circular and has a diameter larger than the diameter of the directional sliding groove 11. The rotating portion 103 is a hexagonal structure, which is convenient for rotating and installing the locking member 10. The inner wall of the upper port of the directional sliding groove 11 is provided with internal threads, and the threaded portion 101 is threadedly connected with the internal threads of the directional sliding groove 11.

[0040] Moreover, a positioning through-hole 104 is provided on the locking member 10. The positioning through-hole 104 penetrates through the threaded portion 101, the positioning portion 102 and the rotating portion 103. A positioning rod 13 is fixedly connected between the disc 8 and the support member 2. The positioning rod 13 is slidably connected with the positioning through-hole 104. By using the guiding function provided by the positioning rod 13, the support member 2 is enabled to move along the axial direction of the support member 2 and the crucible table 1. Threaded heads are provided at both ends of the positioning rod 13, and the threaded heads are threadedly connected with both the disc 8 and the support member 2, which is convenient for disassembly and replacement.

[0041] The working principle of the height-adjustable crucible table structure provided by the present utility model: The crucible carrying the coating material is placed on the support member 2. The vacuum coating machine is started. After the coating material liquefies and evaporates on the upper surface, the liquid level drops, and at the same time the weight decreases. Under the action of the spring 9, the support member 2 rises to perform a rising compensation for the drop of the liquid level, so that the liquid level on the surface of the coating material remains at a constant position, and the distance between the liquid level of the coating material and the substrate remains constant, so that the film thickness of the liquid level of the coating material reaching the surface of the substrate is at a constant value, so as to ensure the uniformity of the film formation on the substrate, reduce the difference in the coating thickness on the substrate, facilitate the correction of the thickness error, improve the optical performance of the film on the substrate, and further improve the coating quality of the substrate. Moreover, it can flexibly adjust the lifting speed of the support member 2 according to the liquid level drop speed of different coating materials, improve the coating efficiency, and has a simple structure, low cost, is convenient for installation and implementation, and is convenient for popularization and use.

[0042] Taking a 1.5-meter vacuum coating machine as an example, specific description is as follows.

[0043] In a 1.5-meter vacuum coating machine, the distance from the evaporation source to the substrate position directly above is about 1000 mm; for a super multi-layer thin film system, taking high refractive index Ti 3 O 5 as an example, the thickness of a certain layer is 130 nm, the film formation rate is 3.5 Å / s, and the coating time is about 360 s; after coating this layer, Ti 3 O 5 the liquid level drops by about 2 mm (measured actually). That is, after the liquid level drops, the distance from the evaporation point to the substrate increases to 1002 mm. Regarding the evaporation source as a point light source, it emits light according to a certain divergence angle, and assuming that the connection line between the substrate and the evaporation source is perpendicular to the horizontal axis, the substrate is horizontally placed on the umbrella frame. Let A represent the film thickness obtained at a distance of 1000 mm, and B represent the film thickness obtained at a distance of 1002 mm. According to the basic formula of brightness, A:B = (1002:1000) 2≈1.004, that is, after the liquid level drops by 2 mm, the film thickness decreases by 0.4%. In many multi-layer thin film systems with relatively high sensitivity, the impact brought by this 0.4% can sometimes be fatal. Use the lifting structure to control the rise of the support member. For example, give compensation at a rising speed of 2 mm / 360 s ≈ 5.5 μm / s. The support member rises 5.5 μm per second. Control the spring constant so that the rising height of the support member per second is greater than 5.5 μm, keeping the liquid level of the coating material at a certain level all the time.

[0044] In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "connection", "fixation", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or communication with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0045] Obviously, the embodiments described above are only part of the embodiments of the present utility model, rather than all embodiments. The accompanying drawings show the preferred embodiments of the present utility model, but do not limit the patent scope of the present utility model. The present utility model can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present utility model more thorough and comprehensive. Although the present utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing specific embodiments, or perform equivalent replacements for some of the technical features. Any equivalent structure directly or indirectly using the content of the specification and drawings of the present utility model in other related technical fields shall be within the scope of the patent protection of the present utility model by the same token.

Claims

1. A crucible table structure with adjustable height, characterized in that: The invention comprises a crucible table and a support member, wherein the support member is connected to the crucible table by a lifting structure and the support member can be positioned and moved along the axial direction of the crucible table, and when the liquid level in the crucible drops, the support member can move axially relative to the crucible table, the crucible table and the support member are both annular structures, and the outer diameter of the support member is the same as the outer diameter of the crucible table, and a plurality of circumferentially distributed crucible support points are fixed on the top surface of the support member.

2. The crucible table structure with adjustable height according to claim 1, characterized in that: When the coating material evaporates, the rising height per unit time of the support member relative to the axial direction of the crucible table is the same as the falling height of the liquid level in the crucible.

3. The crucible table structure with adjustable height according to claim 1, characterized in that: The lifting structure includes a disc, a spring and a locking piece. The crucible table is provided with a plurality of circumferentially distributed directional slide grooves, in which a disc is slidably connected, and a locking piece is fixedly connected to the opening of the directional slide groove. The disc and the locking piece are connected by a spring.

4. The crucible table structure with adjustable height according to claim 3, characterized in that: A sleeve is fixedly connected to the inner wall of the directional sliding groove, the diameter of the sleeve is consistent with the diameter of the disc, and the disc is slidably connected to the sleeve.

5. The height-adjustable crucible table structure according to claim 3, characterized in that: The locking member comprises a threaded portion, a positioning portion and a rotating portion which are integrally arranged from bottom to top, the threaded portion is threadedly connected to the inner wall of the upper port of the directional chute, and the positioning portion is positioned and fitted to the upper surface of the crucible table.

6. A crucible table structure with adjustable height according to claim 3 or 4, characterized in that: The locking member is provided with a positioning through hole, a positioning rod is fixedly connected between the disc and the supporting member, and the positioning rod is slidably connected with the positioning through hole.

7. The crucible table structure with adjustable height according to claim 1, characterized in that: The top surface of the crucible table is fixedly connected with circumferentially distributed support tables, and the top surface of the support tables is higher than the top surface of the locking piece.

8. The crucible table structure with adjustable height according to claim 1, characterized in that: The bottom top surface of the crucible table is provided with a boss and a plurality of through holes are provided around the boss.

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