Evaporation boat for vacuum coating machine

Abstract

The utility model relates to the technical field of vacuum coating, in particular to an evaporation boat for a vacuum coating machine, which comprises a heating layer, the heating layer is used for providing a heat source for an evaporation layer, the top of the heating layer is provided with a groove for placing the evaporation layer, and two ends of the heating layer are connected with poles; the evaporation layer is used for melting and evaporating a coating material, the top of the evaporation layer is provided with a containing part for containing the coating material, and the two ends of the containing part are provided with feeding ports; limiting strips are arranged at the two ends of the evaporation boat cover body respectively, and vent holes are evenly distributed in the evaporation boat cover body. According to the evaporation boat, waste of coating materials can be reduced, the coating uniformity is improved, and the service life of the evaporation boat can be effectively prolonged.

Description

Technical Field

[0001] The present application relates to the field of vacuum coating technology, and in particular to an evaporation boat for a vacuum coating machine. Background Art

[0002] As an alternative material to traditional lithium battery aluminum foil, composite aluminum current collectors have become a new development trend for lithium-ion battery current collectors with their high safety, light weight and lower thickness. With the gradual improvement of the process technology of metallized composite current collectors, composite aluminum current collectors with PET as the main matrix have begun to be used in lithium battery terminals in batches. The preparation method of aluminum composite current collectors, the current mainstream process route in the industry is to deposit a layer of aluminum with a thickness of 0.5-1.5μm on a polymer matrix by vacuum evaporation. In the aluminum evaporation process, the evaporation carrier has always been a point with extremely high cost and difficult operation. At high temperatures, aluminum liquid has extremely high activity and will react with most metals and compounds. After continuous optimization and screening, the industry has adopted the external heating mode based on boron nitride crucibles and the electric heating mode of ceramic evaporation boats as the two mainstream solutions. Since the electric heating method of evaporation boats has the advantages of easy operation and low cost, it has a broader development prospect.

[0003] The main components of the ceramic evaporation boat are boron nitride, titanium diboride, aluminum nitride and a small amount of additives. Titanium diboride provides the evaporation boat with electrical conductivity and a certain resistivity to achieve the purpose of electric heating. Boron nitride makes the evaporation boat have better machinability and heat shock resistance. Boron nitride can also react with aluminum liquid to form a protective layer of aluminum nitride, reducing the corrosion rate of the boat; the addition of aluminum nitride increases the evaporation boat's resistance to aluminum liquid corrosion and thermal shock. The two biggest problems of the evaporation boat are boat corrosion and aluminum liquid splash; the principle of boat corrosion is that at high temperature, liquid aluminum reacts with boron nitride and other components to loosen the titanium diboride and aluminum nitride components on the surface, and combined with the scouring of aluminum liquid dripping, pits are formed on the boat surface, shortening the life of the evaporation boat. After research, it was found that there are four main reasons for the splash of aluminum liquid in the evaporation boat: First, the components of the evaporation boat itself react with the aluminum liquid to produce gas and other by-products, causing splashing; second, the temperature difference between the aluminum liquid and the surface of the evaporation boat is large, and the unstable surface of the aluminum liquid will cause the aluminum liquid to expand to the high temperature zone, and the instantaneous temperature difference will cause splashing; third, with the use of the evaporation boat, titanium diboride and side reaction impurities are washed to the edge of the aluminum liquid, forming loose granular crystals, which have poor bonding strength with the boat body and are prone to splashing; fourth, as the corrosion pits of the evaporation boat become larger, the temperature distribution difference on the surface of the boat body increases. Aluminum liquid splashing will cause aluminum metal bumps on the membrane surface, and even burn through the base film to form pinholes in severe cases. At the battery end, on the one hand, it will cause coating and rolling belt breakage, reducing the process yield; on the other hand, it is easy to cause diaphragm puncture, increase the short circuit rate of the process, and cause the risk of self-discharge. Utility Model Content

[0004] In order to overcome the problems in the prior art, the present application provides an evaporation boat for a vacuum coating machine.

[0005] The present application provides an evaporation boat for a vacuum coating machine using the following technical solution:

[0006] An evaporation boat for a vacuum coating machine comprises a heating layer, which is used to provide a heat source for the evaporation layer, a groove for placing the evaporation layer is provided on the top of the heating layer, and poles are connected at both ends; an evaporation layer, which is used to melt and evaporate the coating material, a receiving portion for placing the coating material is provided on the top of the evaporation layer, and feed ports are provided at both ends of the receiving portion; an evaporation boat cover, limit strips are respectively provided at both ends of the evaporation boat cover, and ventilation holes are evenly distributed on the evaporation boat cover.

[0007] By adopting the above technical solution, the evaporation boat in the present application is divided into two layers, the lower layer is a heating layer for providing a heat source to heat the evaporation layer, and the upper layer is an evaporation layer for placing the coating material and melting and evaporating under the action of the heating layer, wherein the feed ports at both ends of the evaporation layer are used to introduce the coating material. The vent holes evenly distributed on the evaporation boat cover on the top of the evaporation layer can effectively prevent the coating material in the evaporation layer from splashing to the outside when boiling, reduce the waste of coating materials, and improve the uniformity of the coating.

[0008] Preferably, the evaporation layer and the feed port are integrally formed or connected by welding.

[0009] Preferably, the accommodation portion is a pit formed on the surface of the evaporation layer, and the pit is located between the two poles.

[0010] By adopting the above technical solution, the evaporation layer and the feed ports at both ends are designed as a whole, so that the heating layer heats the evaporation layer more evenly, and the accommodating portion on the evaporation layer is a pit arranged on the surface of the evaporation layer, which facilitates the feed ports to feed from both ends.

[0011] Preferably, buffer platforms are provided on both sides of the accommodating portion, wherein an anti-overflow barrier layer is provided on the peripheral edge of the buffer platform.

[0012] Preferably, the bottom surface of the feed port is inclined upward from the bottom surface of the accommodating portion, and buffer platforms with anti-overflow barrier layers identical to those of the accommodating portion are installed on both sides of the feed port.

[0013] By adopting the above technical solution, the buffer platforms on both sides of the accommodating part are used to cool the overflowed high-temperature coating liquid, and are blocked by the anti-overflow barrier layer on the outer edge, effectively inhibiting the high-temperature coating liquid from contacting the heating layer and causing damage to the heating layer.

[0014] Preferably, the heating layer and the evaporation layer are both in the form of rectangular parallelepiped, wherein the depth of the groove on the heating layer is 3-5 mm, and the depth of the accommodation portion on the evaporation layer is 1-2 mm.

[0015] Preferably, the bottom of the evaporation layer is embedded in the groove of the heating layer, and the top opening of the evaporation layer is provided with limiting grooves adapted to the evaporation boat cover and distributed along the length direction of the evaporation layer.

[0016] By adopting the above technical solution, the groove on the heating layer is used to accommodate the evaporation layer, and the accommodating portion on the evaporation layer can store the coating material, wherein the limiting groove arranged at the top opening of the evaporation layer is used to place the evaporation boat cover.

[0017] Preferably, the depth of the limiting groove is greater than the height of the limiting strip, and an overflow groove through-hole connecting the accommodating portion and the buffer platform is provided at the bottom of the limiting groove.

[0018] By adopting the above technical solution, the overflow groove provided at the bottom of the limiting groove can guide the liquid splashed and overflowed when the coating liquid boils from the overflow groove perforation to the buffer platform.

[0019] In summary, the present application includes at least one of the following beneficial technical effects:

[0020] 1. This application cancels the electric heating function of the evaporation layer, reduces the corrosion rate of the evaporation boat body, and the evaporation layer is heated by the bottom heating layer to ensure the consistency of the surface temperature of the evaporation boat;

[0021] 2. The evenly distributed ventilation holes on the evaporation boat cover on the top of the evaporation layer in the present application can effectively prevent the coating material in the evaporation layer from splashing to the outside when boiling, reduce the waste of coating material, and improve the uniformity of coating. In addition, in conjunction with the buffer platforms on both sides of the evaporation layer, the high-temperature coating liquid overflowing from the evaporation layer can be cooled, reducing the generation of crystals such as titanium diboride on the surface of the traditional evaporation boat, which can effectively increase the service life of the evaporation boat. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of an evaporation boat for a vacuum coating machine;

[0023] Figure 2 It is a schematic diagram of the explosion structure of a heating layer, an evaporation layer and an evaporation boat cover in an evaporation boat for a vacuum coating machine;

[0024] Figure 3 yes Figure 2 Enlarged view of point A in the middle.

[0025] Explanation of the reference numerals: 1. heating layer; 11. groove; 12. pole; 2. evaporation layer; 21. accommodating portion; 211. feed port; 22. limiting groove; 221. overflow groove perforation; 3. evaporation boat cover; 31. limiting strip; 32. vent; 4. buffer platform; 41. anti-overflow barrier layer. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1-3This application is described in further detail.

[0027] The embodiment of the present application discloses an evaporation boat for a vacuum coating machine.

[0028] Reference Figure 1 , Figure 2 and Figure 3 An evaporation boat for a vacuum coating machine includes a heating layer 1, the heating layer 1 is used to provide a heat source for the evaporation layer 2, a groove 11 for placing the evaporation layer 2 is provided on the top of the heating layer 1, and poles 12 are connected at both ends; the evaporation layer 2, the evaporation layer 2 is used for melting and evaporation of the coating material, a receiving portion 21 for placing the coating material is provided on the top of the evaporation layer 2, and feed ports 211 are provided at both ends of the receiving portion 21; the evaporation boat cover 3, the two ends of the evaporation boat cover 3 are respectively provided with limit strips 31, and the evaporation boat cover 3 is evenly distributed with vents 32. The evaporation boat in the present application is divided into two layers, the lower layer is the heating layer 1 for providing a heat source to heat the evaporation layer 2, and the upper layer is the evaporation layer 2 for placing the coating material and melting and evaporating under the action of the heating layer 1, wherein the feed ports 211 at both ends of the evaporation layer 2 are used to introduce the coating material. The vent holes 32 evenly distributed on the evaporation boat cover 3 on the top of the evaporation layer 2 can effectively prevent the coating material in the evaporation layer 2 from splashing to the outside when boiling, thereby reducing the waste of coating material and improving the uniformity of coating.

[0029] Reference Figure 1 , Figure 2 and Figure 3 The evaporation layer 2 and the feed port 211 are integrally formed. The receiving portion 21 is a pit opened on the surface of the evaporation layer 2, and the pit is located between the two poles 12. The evaporation layer 2 and the feed ports 211 at both ends are designed as a whole, so that the heating layer 1 heats the evaporation layer 2 more evenly, and the receiving portion 21 on the evaporation layer 2 is a pit set on the surface of the evaporation layer 2, which facilitates the feed port 211 to feed from both ends.

[0030] Reference Figure 1 , Figure 2 and Figure 3 , buffer platforms 4 are provided on both sides of the accommodating portion 21, wherein an anti-overflow barrier layer 41 is provided on the peripheral edge of the buffer platform 4. The bottom surface of the feed port 211 is inclined upward from the bottom surface of the accommodating portion 21, and buffer platforms 4 with anti-overflow barrier layers 41, which are the same as those of the accommodating portion 21, are installed on both sides of the feed port 211. The buffer platforms 4 on both sides of the accommodating portion 21 are used to cool the overflowed high-temperature plating liquid, and are blocked by the anti-overflow barrier layer 41 on the peripheral edge, effectively inhibiting the high-temperature plating liquid from contacting with the heating layer 1 and causing damage to the heating layer 1.

[0031] Reference Figure 1 , Figure 2 and Figure 3, the heating layer 1 and the evaporation layer 2 are both rectangular parallelepiped, wherein the groove 11 on the heating layer 1 is 3mm deep, and the receiving portion 21 on the evaporation layer 2 is 1mm deep. The bottom of the evaporation layer 2 is embedded in the groove 11 of the heating layer 1, and the top opening of the evaporation layer 2 is provided with a limiting groove 22 adapted to the evaporation boat cover 3 distributed along the length direction of the evaporation layer 2. The groove 11 on the heating layer 1 is used to accommodate the evaporation layer 2, and the receiving portion 21 on the evaporation layer 2 can store the coating material, wherein the limiting groove 22 provided at the top opening of the evaporation layer 2 is used to place the evaporation boat cover 3.

[0032] Reference Figure 1 , Figure 2 and Figure 3 The depth of the limiting groove 22 is greater than the height of the limiting strip 31, and an overflow groove through-hole 221 is provided at the bottom of the limiting groove 22 to connect the accommodating portion 21 and the buffer platform 4. The overflow groove provided at the bottom of the limiting groove 22 can guide the liquid splashed and overflowed when the coating liquid boils from the overflow groove through-hole 221 to the buffer platform 4.

[0033] Working principle: During operation, the electrode column 12 is energized to heat the heating layer 1 of the evaporation boat to 1700°C, and the aluminum wire is fed into the receiving portion 21 from the feed port 211 of the evaporation layer 2, and the aluminum wire is melted and evaporated to perform coating.

[0034] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An evaporation boat for a vacuum coating machine, characterized in that: include A heating layer (1), the heating layer (1) being used to provide a heat source for the evaporation layer (2), a groove (11) for placing the evaporation layer (2) being provided on the top of the heating layer (1), and poles (12) being connected at both ends; An evaporation layer (2), the evaporation layer (2) being used for melting and evaporating the coating material, a receiving portion (21) for placing the coating material being provided at the top of the evaporation layer (2), and feed ports (211) being provided at both ends of the receiving portion (21); The evaporation boat cover (3) has limit strips (31) at both ends thereof, and vent holes (32) are evenly distributed on the evaporation boat cover (3).

2. The evaporation boat for a vacuum coating machine according to claim 1, characterized in that: The evaporation layer (2) and the feed port (211) are integrally formed or connected by welding.

3. The evaporation boat for a vacuum coating machine according to claim 1, characterized in that: The accommodating portion (21) is a pit formed on the surface of the evaporation layer (2), and the pit is located between the two poles (12).

4. The evaporation boat for a vacuum coating machine according to claim 3, characterized in that: Buffer platforms (4) are provided on both sides of the accommodating portion (21), wherein an anti-overflow barrier layer (41) is provided on the peripheral edge of the buffer platform (4).

5. The evaporation boat for a vacuum coating machine according to claim 2 or 4, characterized in that: The bottom surface of the feed port (211) is inclined upward from the bottom surface of the accommodating portion (21), and buffer platforms (4) with an anti-overflow barrier layer (41) similar to the accommodating portion (21) are installed on both sides of the feed port (211).

6. The evaporation boat for a vacuum coating machine according to claim 1, characterized in that: The heating layer (1) and the evaporation layer (2) are both in the form of rectangular parallelepipeds, wherein the depth of the groove (11) on the heating layer (1) is 3-5 mm, and the depth of the accommodation portion (21) on the evaporation layer (2) is 1-2 mm.

7. The evaporation boat for a vacuum coating machine according to claim 6, characterized in that: The bottom of the evaporation layer (2) is embedded in the groove (11) of the heating layer (1), and the top opening of the evaporation layer (2) is provided with a limiting groove (22) adapted to the evaporation boat cover (3) and distributed along the length direction of the evaporation layer (2).

8. The evaporation boat for a vacuum coating machine according to claim 7, characterized in that: The depth of the limiting groove (22) is greater than the height of the limiting strip (31), and an overflow groove through-hole (221) connecting the accommodating portion (21) and the buffer platform (4) is provided at the bottom of the limiting groove (22).

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