A vapor space distribution self-adjusting evaporation boat for plating materials

Abstract

The application discloses a kind of evaporating boat of plating material vapor space distribution self-adjusting, the evaporating boat includes evaporating boat matrix, heat preservation layer, thermoelectric device, water-cooling coaming, energy storage device, film thickness monitoring device, height monitoring device, control module, height adjusting device, wherein water-cooling coaming, thermoelectric device, heat preservation layer, evaporating boat matrix are split type structure and one-to-one correspondence, sequentially from outside to inside layer distribution.The thermoelectric device can generate electric energy using the temperature difference between the heat preservation layer and the water-cooling coaming, which is stored in the energy storage device for driving the film thickness monitoring device, height monitoring device, control module, and height adjusting device.When the film thickness uniformity error of the plating roller exceeds the set value, the control module will analyze and calculate the film thickness data and distance data based on the self-adjusting algorithm, and feed back the calculation results to the height adjusting device. The height of the two end evaporating boat matrix blocks is adjusted to change the plating material vapor space distribution in the width direction of the plating film, and uniform plating is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of winding type evaporation coating machine, and relates to a plating material vapor space distribution self-adjusting evaporation boat. BACKGROUND

[0002] The evaporation boat in the vacuum coating machine plays a key role in the coating process, which is responsible for loading coating materials and evaporating them by heating. However, in the actual process, the plating material vapor and the evaporation boat substrate temperature often present uneven distribution, which may cause the "end effect" in the coating process, that is, the vapor amount at both ends is less than the middle, thereby causing the problem of uneven film thickness. In order to solve this problem and obtain a film with better uniformity, the common method at present is to adjust the distance between the evaporation boat and the coating roller or change the arrangement of the filling position of the evaporation boat. However, if the distance between the evaporation boat substrate and the coating roller is too small, it may cause the vapor amount to be too large, which may cause the risk of damage to the thin film. In addition, changing the arrangement of the filling position of the evaporation boat substrate on both sides may limit the width of the coating, and also cannot change the status of uneven coating.

[0003] Therefore, it is necessary to ensure that the plating material vapor space distribution and the evaporation boat temperature distribution are as uniform as possible, so as to ensure the uniformity of the film thickness and the stability of the coating quality. SUMMARY

[0004] The purpose of the present application is to provide an evaporation boat with a self-adjusting plating material vapor space distribution function, which aims to solve the problems existing in the current technology. The evaporation boat can ensure the uniformity of the evaporation boat temperature distribution in real time, and can improve the uniformity of the space distribution of the plating material vapor, thereby improving the thickness uniformity of the thin film.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following scheme: the present application provides a plating material vapor space distribution self-adjusting evaporation boat, which comprises an evaporation boat substrate, a thermoelectric device, a heat preservation layer, a water-cooled coaming, a film thickness monitoring device, a height adjusting device, an energy storage device, a height monitoring device and a control module. The evaporation boat substrate is of split structure and is distributed layer by layer from outside to inside.

[0006] In the evaporation process, because the heat preservation layer and the water-cooled coaming have a high temperature difference, a thermoelectric device can be added between the heat preservation layer and the water-cooled coaming. On the one hand, the thermoelectric device can generate electric energy, which can be stored for film thickness monitoring and evaporation boat substrate height adjustment, thereby improving the uniformity of the thin film. On the other hand, due to the different block heat conduction coefficients of the thermoelectric devices corresponding to the two ends and the middle position of the evaporation boat substrate, the heat dissipation amount of the evaporation boat substrate blocks is different, so that the temperature of the evaporation boat substrate blocks can be adjusted to realize the uniformity of the evaporation boat substrate temperature distribution.

[0007] The evaporation boat base blocks are longitudinally symmetrically distributed, and the height of the evaporation boat base blocks other than the middle evaporation boat base block is adjustable, and the adjustable height range and area of the adjustable height evaporation boat base blocks gradually increase from the middle to the ends.

[0008] Preferably, the evaporation area of the adjusted evaporation boat base accounts for 4-6%, 2-3%, and 1-3% of the total evaporation area, respectively.

[0009] The thermoelectric device material is a silicon-germanium alloy, lead telluride, bismuth telluride, bismuth selenide, or indium selenide, and the thermal conductivity of each thermoelectric device block is different by changing the proportion of alloy elements. The inner side of the thermoelectric device is connected to the heat preservation layer, and the outer side is connected to the water-cooled coaming, so that a temperature difference can be formed and electric energy can be generated by using the temperature difference. The thermal conductivity of the thermoelectric device blocks corresponding to the two ends and the middle position of the evaporation boat base is different, so that the heat dissipation process of the evaporation boat base blocks is different, the temperature of the evaporation boat base blocks can be adjusted, and the uniformity of the temperature distribution of the evaporation boat base is realized.

[0010] Preferably, the thermoelectric device adopts a silicon-germanium alloy material. The silicon-germanium alloy material has excellent thermoelectric conversion efficiency and can work reliably in the range of room temperature to 1000℃. Secondly, the thermal conductivity of the silicon-germanium alloy can be changed by adjusting the content of germanium. Generally, with the increase of the content of germanium, the thermal conductivity also increases accordingly. Therefore, when selecting a silicon-germanium alloy, the content of germanium can be adjusted according to specific needs to change its thermal conductivity. Between the heat preservation layer and the water-cooled coaming, different thermal conductivity thermoelectric devices are inserted. Such a design can optimize the heat conduction path and distribution by adjusting the position and thermal conductivity of the thermoelectric device. The thermoelectric device with higher thermal conductivity can be placed in the area with higher evaporation boat temperature to increase heat conduction and reduce the temperature of the area. The thermoelectric device with lower thermal conductivity is placed in the area with lower temperature to reduce heat conduction, so as to realize uniform temperature distribution.

[0011] The heat preservation layer is composed of multiple layers of heat preservation materials with consistent total thickness, but the thickness and type of the heat preservation material of each heat preservation layer block are different. The temperature of the outer side of the heat preservation layer is 500-600℃ during plating, and the heat source side of the thermoelectric device is connected to the outer side of the heat preservation layer.

[0012] The material of the water-cooled coaming is stainless steel, and the water-cooled pipeline is built-in, with the temperature maintained at 30-60℃. The cold source side of the thermoelectric device is connected to the inner side of the water-cooled coaming.

[0013] The material of the energy storage device is a lithium battery, which stores the electric energy generated by the thermoelectric device, and the energy storage device is embedded on the outer side of the water-cooled coaming.

[0014] The film thickness monitoring device, height monitoring device, control module, and height adjusting device can work by using the energy provided by the energy storage device.

[0015] The film thickness monitoring device is powered by the thermoelectric device to monitor the film thickness and feed the film thickness information to the height adjusting device through the control module, and the film thickness detection device can monitor the film thickness in different regions.

[0016] The height adjusting device adjusts the height of the evaporation boat according to the film thickness information obtained by the film thickness monitoring device, and adjusts the two ends of the evaporation boat base to the specified position through the motor drive.

[0017] Preferably, the height adjusting device is driven by a motor, and the height range of the two ends of the evaporation boat base during adjustment is 0-50mm due to the process limitation in vacuum evaporation.

[0018] The height monitoring device is used to monitor the height of the evaporation boat and the film coating roller, and adjust the specific distance between the evaporation boat and the film coating roller according to the height information during film coating.

[0019] The control module receives the film thickness data monitored by the film thickness monitoring device, calculates the height adjustment required by the end evaporation boat base block based on the relationship algorithm between the film thickness distribution uniformity and the distance between the evaporation boat base blocks, and transmits the height data to the height adjusting device to adjust the height of the end evaporation boat base.

[0020]

[0021] Again

[0022]

[0023] In the formula:

[0024]

[0025] In the formula: t is the film thickness, is the angle between the evaporation source normal and the evaporation position.

[0026] The beneficial effects of the present application are:

[0027] (1) The thermoelectric device involved in the present application can convert the temperature difference between the water-cooled surrounding plate and the thermal insulation layer into electrical energy and store it in the energy storage device, which can supply power to the film thickness monitoring device, the height detection device, the control module and the height adjusting device, thereby reducing energy consumption.

[0028] (2) The thermoelectric devices corresponding to the two ends and the middle position of the evaporation boat base have different block thermal conductivity, so that the temperature of the evaporation boat base block can be adjusted to realize the uniformity of the temperature distribution of the evaporation boat base.

[0029] (3) The control module analyzes the film thickness data monitored by the film thickness monitoring device and the distance data monitored by the height monitoring device, and feeds the calculation results to the height adjusting device to adjust the height of the evaporation boat base block at both ends, thereby achieving uniform film coating. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows.

[0031] Figure 1 A plan view of the evaporation boat for self-adjusting distribution of plating material vapor space provided by the present application;

[0032] Figure 2 A front view of the evaporation boat for self-adjusting distribution of plating material vapor space provided by the present application;

[0033] Figure 3 A left view of the evaporation boat for self-adjusting distribution of plating material vapor space provided by the present application. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings in the embodiments of the present application, and the described embodiments are only some of the embodiments of the present application.

[0035] The present application provides an evaporation boat for self-adjusting distribution of plating material vapor space to solve the problems in the prior art, which can save energy, improve film coating uniformity and simplify the process.

[0036] As shown in Figure 1 , Figure 2 and Figure 3 , the present application provides an evaporation boat for self-adjusting distribution of plating material vapor space. The evaporation boat structure is symmetrical, including a water-cooled baffle 1, a thermoelectric device 2, a thermal insulation layer 3, an evaporation boat base 4, a height adjusting device 7 and an energy storage device 5. The outer side of the evaporation boat base 4 is connected with the thermal insulation layer 3, and the thermoelectric device is inserted between the thermal insulation layer 3 and the water-cooled baffle 1. Among them, the thermoelectric devices 2 on both sides and the middle part have different thermal conductivities, and the thermal conductivity of the thermoelectric device in the middle part is larger than that on both sides. At the same time, the energy storage device 5 is connected to the water-cooled baffle 1 to store the electric energy generated by the thermoelectric device 2. The middle part of the evaporation boat 4 is a whole, while the two sides can be adjusted in height. When the film is not uniform, the control module will quickly feed the required height adjustment to the height adjusting device 7. The device can adjust the height of the evaporation boat on both sides according to the relationship between the film thickness and the source base distance. The adjustment mode adopts motor driving, and the number of revolutions and the pitch of the motor are used to accurately adjust the height.

[0037] In embodiment 1, the evaporation boat is made of graphite, the thermoelectric device is made of silicon-germanium alloy, the energy storage device is a common lithium battery, the heat insulation layer is a multi-layer heat insulation structure, each heat insulation layer is high-temperature ceramic, carbon fiber felt, ceramic fiber cotton and high-temperature ceramic, the size of each heat insulation layer is 15mm, 10mm, 5mm and 20mm, the cooling water is 2kg water pressure, the temperature is between 30-60℃, the evaporation boat is connected with a thermocouple, and the temperature of the evaporation boat can be monitored. We compare the evaporation coating equipment of the present application with the traditional evaporation coating equipment, keep the evaporation area of the evaporation boat of the present application and the traditional evaporation boat unchanged, the traditional evaporation boat does not have a self-adjusting function, evaporates copper on a 12μm PET substrate, the winding speed is 300m / min, and the evaporation width is 1.8m. First, we measure the temperature distribution of the evaporation boat of the two devices with an infrared thermometer before coating, and the results of the infrared thermometer show that the temperature distribution of the evaporation boat with the thermoelectric device is more uniform than that of the evaporation boat without the thermoelectric device. Next, the film is prepared according to the actual coating process, and when the film leaves the coating area during the coating stage, the display starts to display the film thickness of each area, and the height adjusting device also starts to work, the height of both sides of the evaporation boat gradually rises, and the height is constantly changed according to the increase of the coating time. After the coating is completed, the film prepared by the evaporation boat of different devices is sampled every 1000m, and the sheet resistance of 1m of the sample is detected by a sheet resistance meter, and the results show that the average value of the sheet resistance error of the 20 samples of the present application is 4‰, and the average value of the sheet resistance of the film evaporated by the traditional evaporation boat in the width direction is 4%.

[0038] In embodiment 2, the evaporation boat is made of graphite, the thermoelectric device is made of silicon-germanium alloy, the energy storage device is a common lithium battery, the heat insulation layer is a multi-layer heat insulation structure, each heat insulation layer is high-temperature ceramic, carbon fiber felt, ceramic fiber cotton and high-temperature ceramic, the size of each heat insulation layer is 15mm, 10mm, 5mm and 20mm, the cooling water is 2kg water pressure, the temperature is between 30-60℃, the evaporation boat is connected with a thermocouple, and the temperature of the evaporation boat can be monitored. Through the use of the evaporation boat of the present application, aluminum is evaporated on a 12μm PET substrate, the winding speed is 300m / min, the coating width is 1.8m, the thermoelectric device, the film monitoring device and the height monitoring device start to work to adjust the height of both ends of the evaporation boat during the coating stage, and the film after the coating is completed is sampled every 1000m, and the sheet resistance of 1m of the sample is detected by a sheet resistance meter, and the results show that the average value of the sheet resistance error of the film in the width direction is 5‰ in 20 samples.

[0039] In the embodiment 3, the evaporation boat is made of graphite material, the thermoelectric device is made of silicon germanium alloy, the energy storage device is made of common lithium battery, the heat preservation layer is made of multi-layer heat preservation structure, each heat preservation layer is high temperature ceramic, carbon fiber felt, ceramic fiber cotton, high temperature ceramic, the size of each heat preservation layer is 15mm, 10mm, 5mm, 20mm, the cooling water is 2kg water pressure, the temperature is between 30-60℃, the evaporation boat is connected with thermocouple, the temperature of the evaporation boat can be monitored. The evaporation boat is used to evaporate and deposit metal copper on the PET substrate with the thickness of 6μm, the winding speed is 300m / min, the film width is 1.8m, the film is taken every 1000m to take 1m sample, the square resistance is detected by the square resistance instrument, the results show that in 20 samples, the average error of the square resistance of the film in the width direction is 4.5‰.

[0040] In the embodiment 4, the process conditions are kept the same as those in the embodiment 1, only the film width is increased to 2.5m, the other conditions are unchanged, 20 samples are taken for testing, the results show that the average error of the square resistance of the film evaporated by the evaporation boat in the width direction is 4.2‰, while the average error of the square resistance of the film evaporated by the traditional evaporation boat in the width direction is 6.8‰.

[0041] In the embodiment 5, the process conditions are kept the same as those in the embodiment 2, only the film width is increased to 2.5m, the other conditions are unchanged, 20 samples are taken for testing, the results show that the average error of the square resistance of the film evaporated by the evaporation boat in the width direction is 5‰.

[0042] In the embodiment 6, the process conditions are kept the same as those in the embodiment 3, only the film width is increased to 2.5m, the other conditions are unchanged, 20 samples are taken for testing, the results show that the average error of the square resistance of the film evaporated by the evaporation boat in the width direction is 4.7‰.

[0043] In the embodiment 7, the process conditions are kept the same as those in the embodiment 1, only the film width is reduced to 0.6m, the other conditions are unchanged, 20 samples are taken for testing, the results show that the average error of the square resistance of the film evaporated by the evaporation boat in the width direction is 1.2‰, while the average error of the square resistance of the film evaporated by the traditional evaporation boat in the width direction is 3‰.

[0044] In the embodiment 8, the process conditions are kept the same as those in the embodiment 2, only the film width is reduced to 0.6m, the other conditions are unchanged, 20 samples are taken for testing, the results show that the average error of the square resistance of the film evaporated by the evaporation boat in the width direction is 2.08‰.

[0045] In the embodiment 9, the process conditions are kept the same as those in the embodiment 3, only the film width is reduced to 0.6m, the other conditions are unchanged, 20 samples are taken for testing, the results show that the average error of the square resistance of the film evaporated by the evaporation boat in the width direction is 1.81‰.

[0046] The above embodiments describe the preferred embodiments of the present application in detail, but the present application is not limited to the specific details in the above embodiments, and equivalent transformations or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

[0047] In addition, it should be noted that the various specific technical features described in the above specific embodiments, such as the thickness of the heat preservation layer, the cooling water pressure, the temperature of the water-cooled surrounding plate, the thickness of the substrate, the substrate material, the winding speed, the evaporation width, the evaporation material, the sampling parameters, etc., can be parameterized and combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present application will not further describe various possible combination manners, as long as they do not deviate from the idea of the present application, they should also be considered as disclosed content of the present application.

Claims

1. A vapor space distribution self-adjusting evaporation boat for plating material, characterized by, The evaporation boat is composed of 9 parts, including: evaporation boat base, heat preservation layer, thermoelectric device, water-cooled panel, energy storage device, film thickness monitoring device, height monitoring device, control module, height adjusting device; the water-cooled panel, the thermoelectric device, the heat preservation layer and the evaporation boat base are in a split structure and one-to-one correspondence, and are distributed layer by layer from outside to inside in turn; the evaporation boat is used according to the following steps: First, cooling water is supplied to the water-cooled panel, and then the evaporation boat base is heated; when the temperature difference between the heat preservation layer and the water-cooled panel reaches the working range of the thermoelectric device, the thermoelectric device starts to work and converts heat energy into electric energy, which is stored in the energy storage device; at the same time, the thermoelectric devices corresponding to the two ends and the middle position of the evaporation boat base have different block heat conduction coefficients, so that the heat dissipation of the evaporation boat base blocks is different, the temperature of the evaporation boat base blocks can be adjusted, and the uniform distribution of the temperature of the evaporation boat base is realized; during the coating process, the film thickness monitoring device can monitor the film thickness data of the coating roller in real time and transmit it to the control module, and the height monitoring device also transmits the distance data between the evaporation boat and the coating roller to the control module; when the film thickness uniformity error of the coating roller exceeds the set value, the control module will analyze and calculate the film thickness data and distance data based on the self-adjusting algorithm, and feed back the calculation results to the height adjusting device to adjust the height of the evaporation boat base blocks at both ends, change the coating material vapor space distribution in the coating width direction, and realize uniform coating.

2. The plating material vapor space distribution self-adjusting evaporation boat according to claim 1, wherein, The evaporation boat base blocks are distributed symmetrically along the longitudinal direction, and the height of the evaporation boat base blocks except the middle evaporation boat base block is adjustable; the adjustable height range and area of the adjustable height evaporation boat base blocks increase from the middle to the both ends.

3. The vapor space distribution self-regulating evaporation boat for plating material according to claim 1, wherein The heat preservation layer is composed of multiple layers of heat preservation materials with consistent total thickness, but the thickness and type of the heat preservation materials of each heat preservation layer block are different; the temperature of the outer side of the heat preservation layer during coating is 500-600℃.

4. The plating material vapor space distribution self-adjusting evaporation boat according to claim 1, wherein, The thermoelectric device material is silicon-germanium alloy, lead telluride, bismuth telluride, bismuth selenide and indium selenide; by changing the proportion of alloy elements, the heat conduction coefficients of each thermoelectric device block are different.

5. The plating vapor space distribution self-adjusting boat of claim 1, wherein, The material of each water-cooled panel block is stainless steel, and the water-cooled pipeline is built-in, with the temperature maintained at 30-60℃.

6. The plating material vapor space distribution self-adjusting evaporation boat according to claim 3 or 4 or 5, characterized in that, Except for the heat preservation layer block, the thermoelectric device block and the water-cooled panel block corresponding to the middle evaporation boat base block, the other heat preservation layer blocks, the thermoelectric device blocks and the water-cooled panel blocks can be adjusted in height together with the corresponding evaporation boat base blocks.

7. The process as claimed in claim 1, wherein the said process is characterized by, The material of the energy storage device is lithium battery, which stores the electric energy generated by the thermoelectric device.

8. The plating vapor space distribution self-adjusting boat of claim 1, wherein, The film thickness monitoring device, the height monitoring device, the control module and the height adjusting device can work by using the energy supplied by the energy storage device.

9. The plating vapor space distribution self-regulating boat of claim 1, wherein, The film thickness monitoring device can transmit the monitored film thickness data to the control module; the control module calculates the height adjustment required by the end evaporation boat base block based on the relationship algorithm between the film thickness distribution uniformity and the distance between each evaporation boat base block according to the height data of the evaporation boat base block monitored by the height monitoring device, and transmits the height data to the height adjusting device to adjust the height of the end evaporation boat base; the film thickness formula is wherein: ​ wherein: t is the film thickness, is the angle between the evaporation source normal and the evaporation position.

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