Preparation method of composite ceramic coating and evaporation boat

Abstract

The invention discloses a preparation method of a composite ceramic coating and an evaporation boat. The preparation method comprises the following steps: S1, arranging a first mask on a boat substrate, and covering the bottom of a groove with a protection layer to prepare an upper coating; s2, preparing a bonding layer on the surface of the boat substrate; s3, preparing a first insulating layer on the surface of the bonding layer; s4, the first mask is removed, a second mask is arranged, and the coverage area of the second mask is smaller than that of the first mask; s5, preparing a conductive layer on the exposed area of the boat substrate and the surface of the first insulating layer; and S6, preparing a second insulating layer on the surface of the conductive layer. According to the invention, the conductive layer and the boat substrate are connected to effectively form a path through a multiple mask technology, so that the interior of the composite ceramic layer is heated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of evaporation boat, and particularly relates to a composite ceramic coating preparation method and an evaporation boat. BACKGROUND

[0002] In the field of thin film deposition, in the resistance evaporation process of metals such as gold, silver, tin, copper, aluminum and alloys thereof, the film material is usually placed in a boat made of high-melting-point metals such as tungsten and molybdenum, heated to a molten state and then evaporated into a film. Due to high current, high temperature, surface tension of liquid metal and other reasons, the molten liquid metal is easy to overflow and splash in the boat, the film plating process is unstable, the noble metal film material is wasted, and the product yield is low.

[0003] We plan to use a ceramic coating to break the surface tension between the boat and the liquid metal. However, the ceramic is not easy to be directly and firmly combined with the boat substrate. At the same time, since the ceramic itself is insulating and has much lower thermal conductivity than metal, the thermal expansion and contraction effect caused by large temperature difference under high current and high temperature can easily cause the ceramic coating to be detached from the boat substrate. SUMMARY

[0004] To solve the above problems, the application provides a composite ceramic coating preparation method and an evaporation boat. Through multiple masking techniques, the conductive layer is connected with the boat substrate to effectively form a path, thereby heating the inside of the composite ceramic layer.

[0005] The technical scheme provided by the application is as follows: On the one hand, a composite ceramic coating preparation method includes the following steps: S1: A first mask is arranged on the boat substrate to cover and protect the bottom of the groove to avoid preparing the upper coating; S2: A bonding layer is prepared on the surface of the boat substrate; S3: A first insulating layer is prepared on the surface of the bonding layer; S4: The first mask is removed, and a second mask is arranged, the covering area of the second mask being smaller than that of the first mask; S5: A conductive layer is prepared on the exposed area of the boat substrate and the surface of the first insulating layer; S6: A second insulating layer is prepared on the surface of the conductive layer.

[0006] In some embodiments, the method further includes step S7: repeating steps S4-S6 to prepare the conductive layer and the insulating layer for multiple cycles.

[0007] In some embodiments, before step S1, the boat substrate is sandblasted to remove residual stains and grease in the metal boat forming process.

[0008] In some embodiments, the material of the bonding layer is nickel or chromium or an alloy thereof, the preparation process of the bonding layer is plasma spraying, and the prepared thickness is 100 nm-0.1 mm.

[0009] In some embodiments, the material of the first and second insulating layers is ceramic, the preparation process is plasma spraying, and the prepared thickness is 0.1 mm-2 mm.

[0010] In some embodiments, the material of the first and second insulating layers is aluminum oxide.

[0011] In some embodiments, the material of the conductive layer is a metal element or an alloy, the preparation process is plasma spraying, and the prepared thickness is 100 nm-0.1 mm.

[0012] In another aspect, an evaporation boat for use in the above-mentioned composite ceramic coating preparation method comprises a boat body and a composite ceramic coating arranged on the inner side of the side wall of the boat body.

[0013] In summary, the present application has the following advantages: (1) The present application effectively forms a path by connecting the conductive layer to the boat substrate through multiple masking techniques, thereby heating the inside of the composite ceramic layer.

[0014] (2) The evaporation boat of the present application effectively breaks the surface tension between the molten liquid metal film material and the boat substrate material by using a ceramic insulating layer, greatly inhibiting the overflow of the film material. By inserting a conductive layer in the ceramic insulating layer, the temperature inside the ceramic insulating layer is increased, reducing the temperature difference between it and the boat substrate, effectively preventing the ceramic film layer from falling off due to high temperature during the process. At the same time, this structure also reduces the temperature difference between the bottom of the evaporation boat and the ceramic coating covering the side wall, inhibiting the splashing of the film material.

[0015] (3) The bonding layer, insulating layer and conductive layer of the present application can all be prepared by plasma spraying process, which can be realized by different spray guns of the same equipment, avoiding the problems of impurity pollution and long process preparation time caused by switching of process equipment. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a flow chart of the method of the present application; Figure 2 is a schematic diagram of step S1; Figure 3 is a schematic diagram of steps S2-S3; Figure 4 is a schematic diagram of step S4; Figure 5 is a schematic diagram of steps S5-S6; Figure 6A schematic diagram of the composite ceramic coating structure prepared for Example 1; Figure 7 A schematic diagram of the composite ceramic coating structure prepared for Example 2; Figure 8 A schematic diagram of the side view structure of the evaporation boat; Figure 9 A physical diagram of the evaporation boat prepared by the method of the present application.

[0017] The reference signs are as follows: 1, boat base; 2, first mask; 3, bonding layer; 4, first insulating layer; 5, second mask; 6, conductive layer; 7, second insulating layer; 8, boat body; 9, composite ceramic coating. DETAILED DESCRIPTION

[0018] In order to deepen the understanding of the present application, the present application will be further described in conjunction with examples below, which are only used to explain the present application and do not constitute a limitation on the protection scope of the present application.

[0019] Example 1 Please refer to Figures 1-5 The present embodiment provides a preparation method of a composite ceramic coating, which constructs a composite coating with a multi-layer structure on the surface of a metal base of an evaporation boat, including a bonding layer 3, an insulating layer, and a conductive layer 6 multi-layer structure, thereby significantly improving the heating performance, structural stability, and service life of the evaporation boat, including the following steps: Before starting the entire preparation process, the boat base 1 needs to be sandblasted first to remove the residual stains and grease in the metal boat forming process, so as to ensure the adhesion of the composite ceramic coating 9. The material of the boat base 1 is a high-melting-point metal, which can use tungsten, molybdenum, and the like, and their alloys. In the present embodiment, the boat base 1 is prepared by using tungsten material.

[0020] S1: A first mask 2 is arranged on the boat base 1 to protect the conductive legs at the bottom of the groove and both ends of the boat from being prepared with the upper coating. The coating in the present embodiment does not have high requirements on the size accuracy, and the first mask 22 can select a metal mask block or directly coat a metal film as a mask.

[0021] S2: A bonding layer 3 is prepared on the surface of the boat base 1. The bonding layer 3 should be selected from a material that has good bonding effect with the boat base 1 and the ceramic coating at the same time. In the present embodiment, the material of the bonding layer 3 is selected as nickel-chromium alloy, and 0.1 mm is prepared as the bonding layer 3 by ion plating. Of course, in other embodiments, nickel and chromium elements can also be selected. Since the ceramic and the boat base 1 are not easy to be directly and firmly combined, the bonding layer 3 is specially arranged to improve the bonding force between the ceramic and the boat base 1.

[0022] S3: Further prepare a first insulating layer 4 on the surface of the bonding layer 3, in this embodiment, the insulating layer uses aluminum oxide as a ceramic insulating layer, and the insulating layer is prepared to be 1 mm thick using a plasma spraying process.

[0023] S4: Since the ceramic is inherently insulating and has a much lower thermal conductivity than metal, it is prone to delamination between the ceramic coating and the boat substrate 1 due to the thermal expansion and contraction effect caused by a large temperature difference at high current and high temperature. Therefore, a thin conductive layer 6 needs to be prepared in the ceramic insulating layer to suppress the temperature difference between the two and prevent delamination.

[0024] In order to enable the conductive layer 6 to form a conduction with the metal substrate of the boat, after the first insulating layer 4 is prepared, the first mask 2 is removed, and a second mask 5 is set, the second mask 5 covers a smaller area than the first mask 2, providing an opening area for subsequent local deposition of the conductive layer 6, and ensuring that part of the boat substrate 1 can be exposed to form a conduction with the conductive layer 6.

[0025] S5: Prepare a conductive layer 6 on the exposed area of the boat substrate 1 and the surface of the first insulating layer 4, the material of the conductive layer 6 is a metal element or an alloy, in this embodiment, ultra-fine high-purity gold powder is used, and the conductive layer 6 is prepared by a plasma spraying process, the thickness of the conductive layer 6 should be adjusted through experiments, and in this embodiment, it is preferably 500 nm.

[0026] S6: Prepare a second insulating layer 7 on the surface of the conductive layer 6, to obtain a composite ceramic coating 9 as shown in Figure 4 , in this embodiment, the preparation process and material of the second insulating layer 7 are the same as those of the first insulating layer 4, and the thickness of the second insulating layer 7 is also about 1 mm.

[0027] In this embodiment, the ceramic insulating layer effectively breaks the surface tension between the molten liquid metal film and the evaporated boat substrate material, greatly suppressing the overflow of the film.

[0028] In this embodiment, the conductive layer 6 is inserted in the ceramic insulating layer, which improves the temperature inside the ceramic insulating layer and reduces the temperature difference between the ceramic insulating layer and the evaporated boat substrate, effectively preventing the ceramic film from falling off caused by high temperature in the process. At the same time, this structure also reduces the temperature difference between the bottom of the evaporated boat and the ceramic coating covering the sidewall, and suppresses the splashing problem of the film.

[0029] Further, in this embodiment, the bonding layer 3, the insulating layer, and the conductive layer 6 can all be prepared by a plasma spraying process at the same time, which can be realized by different spray guns of the same equipment, avoiding the problems of impurity pollution and long process preparation time caused by switching of process equipment.

[0030] Embodiment 2 Please refer to Figure 6 , 7The embodiment is different from embodiment 1 in that it has multiple conductive layers 6, that is, only steps S4-S6 in embodiment 1 need to be repeated to prepare the conductive layer 6 and the insulating layer in multiple cycles. The number of conductive layers 6 can be adjusted according to the actual application requirements. Of course, it is found in multiple tests that in the case of increasing the number of conductive layers 6, the thickness of each insulating layer needs to be reduced to ensure the use effect of the evaporation boat.

[0031] In the embodiment, the conductive layer 6 is connected to the boat base 1 through multiple mask techniques to effectively form a path, thereby more uniformly heating the inside of the composite ceramic layer and reducing the temperature difference between the composite ceramic layer and the evaporation boat base 1, effectively preventing the ceramic film layer from falling off caused by high temperature in the process.

[0032] Embodiment 3, Please refer to Figure 8 、 9 The embodiment provides an evaporation boat prepared by using the composite ceramic coating preparation method, which comprises a boat body 8 and a composite ceramic coating 9. The composite ceramic coating 9 is arranged on the inner side of the side wall of the boat body 8. In use, the ceramic insulating layer effectively breaks the surface tension between the molten liquid metal film material and the evaporation boat base material, and greatly inhibits the overflow of the film material.

[0033] It should be noted that the implementation not shown or described in the drawings or the specification is known to those skilled in the art, and is not described in detail. In addition, the definitions of the elements and methods described above are not limited to the specific structures, shapes or methods mentioned in the embodiments.

[0034] It should be further noted that the directional terms mentioned in the embodiments, such as "up", "down", "front", "back", "left", "right", "inside" and "outside", are only with reference to the direction of the drawings and are not intended to limit the protection scope of the present application.

[0035] The above description shows and describes the preferred embodiments of the present application. As mentioned above, it should be understood that the present application is not limited to the forms disclosed herein and should not be considered as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the inventive concept described herein by the above teachings or related art or knowledge. Any modification and change made by those skilled in the art without departing from the spirit and scope of the present application shall be within the protection scope of the appended claims of the present application.

Claims

1. A method of making a composite ceramic coating, characterized by, The method comprises the following steps: S1: setting a first mask (2) on the boat base (1) to cover the groove bottom and protect it from being coated; S2: preparing a bonding layer (3) on the surface of the boat base (1); S3: preparing a first insulating layer (4) on the surface of the bonding layer (3); S4: removing the first mask (2) and setting a second mask (5), wherein the covering area of the second mask (5) is smaller than that of the first mask (2); S5: preparing a conductive layer (6) on the exposed area of the boat base (1) and the surface of the first insulating layer (4); S6: preparing a second insulating layer (7) on the surface of the conductive layer (6).

2. The method of claim 1, wherein The method further comprises the following step S7: repeating steps S4-S6 to prepare the conductive layer (6) and the insulating layer in multiple cycles.

3. The method of claim 1, wherein the ceramic coating is a composite ceramic coating. Before step S1, the boat base (1) is sandblasted to remove the residual stains and grease in the metal boat forming process.

4. The method of claim 1, wherein The bonding layer (3) is made of nickel or chromium or an alloy thereof, and is prepared by plasma spraying with a thickness of 100 nm-0.1 mm.

5. The method of claim 1, wherein The first insulating layer (4) and the second insulating layer (7) are made of ceramic and are prepared by plasma spraying with a thickness of 0.1 mm-2 mm.

6. The method of claim 1, wherein The first insulating layer (4) and the second insulating layer (7) are made of aluminum oxide.

7. The method of claim 1, wherein the ceramic coating is a composite ceramic coating. The conductive layer (6) is made of a metal element or an alloy and is prepared by plasma spraying with a thickness of 100 nm-0.1 mm.

8. A boat for use in the method of claim 1-7, wherein, The boat body (8) and the composite ceramic coating (9) are included, and the composite ceramic coating (9) is arranged on the inner side of the side wall of the boat body (8).

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