Method for increasing refractive index of trititanium pentoxide coating layer

Abstract

The invention discloses a method for increasing the refractive index of a trititanium pentoxide coating layer, which comprises the following steps: loading a substrate into vacuum coating equipment, and vacuumizing the vacuum coating equipment; when the vacuum degree reaches 2.5 * 10 <-3 > Pa and below, starting the high voltage of the electron gun; the temperature of the trititanium pentoxide is increased, when the temperature reaches 1850 DEG C or above, an electronic gun shielding cover is opened, the evaporation rate of the trititanium pentoxide is controlled to be smaller than or equal to 2.0 am / s, the flow rate of filled oxygen is controlled, and coating is conducted under the condition that the vacuum degree is not higher than 8.5 * 10 <-3 > Pa. By controlling the vacuum degree of the coating equipment, the evaporation rate of the trititanium pentoxide and the flow rate of the oxygen, the refractive index of the obtained trititanium pentoxide coating layer is obviously improved.

Description

Technical Field

[0001] The invention relates to the technical field of vacuum coating, and in particular to a method for improving the refractive index of a titanium pentoxide coating layer. Background Art

[0002] Titanium pentoxide (Ti3O5) is one of the optical coating materials. It is insoluble in water and has the advantages of high refractive index, low resistance, strong adhesion and not easy to splash. It is deposited by electron gun evaporation. The optical surface finish is good after film formation. Its application areas include filters, cold light source coatings, anti-reflection films, multi-layer films, etc.

[0003] However, the refractive index of the titanium pentoxide coating layer prepared by the existing electron gun evaporation method is low, resulting in the optical performance of the coating failing to meet the design requirements.

[0004] Therefore, the prior art needs to be further improved and enhanced. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for improving the refractive index of a titanium pentoxide coating layer, aiming to solve the problem that the refractive index of the titanium pentoxide coating layer prepared by the existing electron gun evaporation method is low.

[0006] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0007] A method for increasing the refractive index of a titanium pentoxide coating layer, comprising:

[0008] Loading the substrate into a vacuum coating device and performing a vacuum treatment on the vacuum coating device;

[0009] When the vacuum degree reaches 2.5*10 -3 When the voltage is Pa or below, the electron gun high voltage is started;

[0010] The temperature of titanium pentoxide is raised. When the temperature reaches 1850°C or above, the electron gun shield is opened, the evaporation rate of titanium pentoxide is controlled to be less than or equal to 2.0 am / s, and the flow rate of oxygen is controlled to be filled in a vacuum degree not higher than 8.5*10 -3 Pa coating conditions.

[0011] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0012] As a preferred technical solution, the method for improving the refractive index of the titanium pentoxide coating layer, wherein the vacuum coating equipment is evacuated, specifically comprising: starting a mechanical pump and a Roots pump, measuring the vacuum degree in the vacuum coating equipment, and when the vacuum degree reaches a first preset value, starting a cold pump to evacuate until the vacuum degree in the vacuum coating equipment reaches 2.5*10 -3 Pa and below.

[0013] As a preferred technical solution, in the method for improving the refractive index of the titanium pentoxide coating layer, the first preset value is 5.0*10Pa.

[0014] As a preferred technical solution, in the method for improving the refractive index of the titanium pentoxide coating layer, the flow rate of the oxygen is 35-45 sccm.

[0015] As a preferred technical solution, in the method for improving the refractive index of a titanium pentoxide coating layer, the substrate is a composite plate after transfer; and before coating the surface of the substrate, the substrate is first cleaned by an ion source.

[0016] As a preferred technical solution, the method for improving the refractive index of the titanium pentoxide coating layer, wherein the vacuum degree is not higher than 8.5*10 -3 The film is deposited under the condition of 2.50 Å / min Pa, and the thickness of the film is 280-320 nm.

[0017] As a preferred technical solution, in the method for improving the refractive index of the titanium pentoxide coating layer, the power of the titanium pentoxide target source is 2.1-2.2KW.

[0018] As a preferred technical solution, in the method for improving the refractive index of a titanium pentoxide coating layer, the evaporation rate of the titanium pentoxide is 1.8-2.0 am / s.

[0019] As a preferred technical solution, the method for improving the refractive index of the titanium pentoxide coating layer is as follows: the vacuum coating equipment is an I KS-2700 vacuum coating machine; and the electron gun is a 270°E type electron gun.

[0020] Beneficial effect: Compared with the prior art, the present invention significantly improves the refractive index of the obtained titanium pentoxide coating layer by controlling the vacuum degree of the coating equipment, the evaporation rate of titanium pentoxide and the flow rate of oxygen (the refractive index of the film layer measured by the spectrometer is N=2.23, and the refractive index of the existing process is N=2.0). DETAILED DESCRIPTION

[0021] The embodiment of the present application provides a method for improving the refractive index of a titanium pentoxide coating layer. To make the purpose, technical solution and effect of the present application clearer and more specific, the following examples are listed to further describe the present application in detail. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0022] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be an intermediate element. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0023] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with those in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as here.

[0024] It should be understood that the sequence number and size of each step in this embodiment do not mean the order of execution, and the execution order of each process is determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of this application. All instruments used are commercially available products.

[0025] The inventors have found through research that the conventional electron gun coating process is the evaporation vacuum coating of Ti3O5 film in a high vacuum environment, which is generally maintained at 1.5-2Pa, and the coating process is filled with O2. However, the refractive index of the obtained coating layer is low. In order to solve this technical problem, the inventors of the present invention provide a method for improving the refractive index of titanium pentoxide coating layer, comprising the following steps:

[0026] S10, loading the substrate into a vacuum coating device, and performing a vacuum treatment on the vacuum coating device.

[0027] Specifically, the vacuum coating equipment used can be a common vacuum equipment in this field, but the vacuum coating equipment is required to have a good vacuum degree, that is, the vacuum degree of the vacuum coating equipment must be able to meet the requirements of this technical solution. As for the specific structure and specific model of the vacuum coating equipment, no requirements are made here. As an example, the vacuum coating equipment used in the present invention is an I KS-2700 vacuum coating machine. The substrate is placed on the umbrella leaf of the vacuum coating machine. The umbrella leaf is a structure for supporting and evenly distributing the coating material. Close the machine furnace door, rotate the umbrella leaf frame, turn on the front group vacuum pump, and start the vacuum system. Mechanical pump EDARDS-NES750 + Roots pump EH4200, measure the vacuum degree.

[0028] Among them, the substrate used is a composite substrate that has been transferred. The transfer treatment of the substrate can ensure that the surface of the substrate has a high degree of flatness, which is crucial for obtaining a uniform film. An uneven surface may lead to uneven coating and affect product performance. The composite substrate may be composed of a variety of materials. The transfer treatment can ensure good compatibility between these materials and with the coating material to avoid delamination or peeling due to material incompatibility. During the vacuum coating process, both the substrate and the film will experience high temperatures. The composite substrate that has been transferred usually has good thermal stability and can withstand temperature changes during the coating process without deformation or damage.

[0029] S20, when the vacuum degree reaches 2.5*10 -3 Pa and below, start the electron gun high voltage.

[0030] Specifically, in step S10, the vacuum system is started. When the vacuum degree reaches 5.0*10Pa, the high vacuum valve is opened, the cold pump is pumped, and the PLOY COOLD deep cold is started to charge -135℃ refrigerant into the copper tube inside the machine. The copper tube captures water vapor and increases the vacuum degree. When the vacuum degree reaches 2.5*10 -3 Pa, start the electron gun high voltage. Among them, a mechanical pump is used in the initial vacuum stage, and a cold air pump is used for further vacuuming in the later stage. Through step-by-step vacuuming, most of the air and oil vapor can be removed first, reducing the pollution to the high vacuum environment. Step-by-step vacuuming can more effectively remove gases in the system, including gases that are difficult to pump such as water vapor, oil vapor, etc., thereby achieving a higher vacuum degree. During the vacuum coating process, the substrate and the coating material may be impacted by gas molecules. Step-by-step vacuuming can reduce this impact and protect the integrity of the material. High vacuum helps to achieve a more uniform and purer film. Step-by-step vacuuming helps to achieve the required vacuum degree, thereby improving the coating quality.

[0031] S30, heating the titanium pentoxide, and when the temperature reaches 1850°C or above, opening the electron gun shield, controlling the evaporation rate of the titanium pentoxide to be less than or equal to 2.0 am / s, controlling the flow rate of the oxygen, and -3 Pa coating conditions.

[0032] Specifically, when the vacuum degree reaches 2.5*10 -3 PaPa, start the 270°E electron gun high voltage, rotate the crucible, and the Ti3O5 crucible reaches the specified position. Gradually increase the electron gun current to 350mA, and the surface temperature of Ti3O5 in the crucible reaches 1850℃. Open the electron gun shielding cover, and the crystal controller monitors the Ti3O5 evaporation rate to be 2.0am / s. The APC controller is filled with process gas O2, and the O2 flow rate is 40sccm. At this time, the vacuum degree is 8.5*10 -3 Pa, and continue coating until the total thickness of the deposited film is 300nm.

[0033] The above technical solution provided by the present invention is further explained below through a specific preparation method.

[0034] Example 1

[0035] In the I KS-2700 vacuum coating machine, take the transferred composite board and load it onto the umbrella leaf. Close the machine furnace door, rotate the umbrella leaf frame, turn on the vacuum pump of the front stage group, start the vacuum pumping system, mechanical pump EDARDS-NES750 + Roots pump EH4200, measure the vacuum degree and draw it to 5.5*10Pa, open the high vacuum valve, pump the cold pump, start the PLOY COOLD deep cold and fill the -135℃ refrigerant into the copper tube inside the machine. The copper tube captures water vapor and increases the vacuum degree. When the vacuum degree reaches 2.5*10 -3 Pa, start the 270°E electron gun high voltage, rotate the crucible, and the Ti3O5 crucible reaches the specified position. Gradually increase the electron gun current to 350mA, and the surface temperature of Ti3O5 in the crucible reaches 1850℃. Open the electron gun shielding cover, and the crystal controller monitors the Ti3O5 evaporation rate to be 2.0am / s. The APC controller is filled with process gas O2, and the O2 flow rate is 40sccm. At this time, the vacuum degree is 8.5*10 -3 Pa, continuous coating, the total thickness of the deposited film is 300nm. The refractive index of the film measured by the spectrometer is N=2.23.

[0036] Example 2

[0037] In the I KS-2700 vacuum coating machine, take the transferred composite board and load it onto the umbrella leaf. Close the machine furnace door, rotate the umbrella leaf frame, turn on the vacuum pump of the front stage group, start the vacuum pumping system, mechanical pump EDARDS-NES750 + Roots pump EH4200, measure the vacuum degree and draw it to 5.0*10Pa, open the high vacuum valve, pump the cold pump, start the PLOY COOLD deep cooling and fill the -135℃ refrigerant into the copper tube inside the machine. The copper tube captures water vapor and increases the vacuum degree. When the vacuum degree reaches 2.2*10 -3 Pa, start the 270°E electron gun high voltage, rotate the crucible, and the Ti3O5 crucible reaches the specified position. Gradually increase the electron gun current to 400mA, and the surface temperature of Ti3O5 in the crucible reaches 1850℃. Open the electron gun shielding cover, and the crystal controller monitors the Ti3O5 evaporation rate to be 1.8am / s. The APC controller is filled with process gas O2, and the O2 flow rate is 35sccm. At this time, the vacuum degree is 8.5*10 -3 Pa, continuous coating, the total thickness of the deposited film is 250nm. The refractive index of the film measured by the spectrometer is N=2.18.

[0038] Example 3

[0039] In the I KS-2700 vacuum coating machine, take the transferred composite board and load it onto the umbrella leaf. Close the machine furnace door, rotate the umbrella leaf frame, turn on the vacuum pump of the front stage group, start the vacuum pumping system, mechanical pump EDARDS-NES750 + Roots pump EH4200, measure the vacuum degree and draw it to 5.0*10Pa, open the high vacuum valve, pump the cold pump, start the PLOY COOLD deep cold and fill the -135℃ refrigerant into the copper tube inside the machine. The copper tube captures water vapor and increases the vacuum degree. When the vacuum degree reaches 2.0*10 -3 Pa, start the 270°E electron gun high voltage, rotate the crucible, and the Ti3O5 crucible reaches the specified position. Gradually increase the electron gun current to 350mA, and the surface temperature of Ti3O5 in the crucible reaches 1850℃. Open the electron gun shielding cover, and the crystal controller monitors the Ti3O5 evaporation rate to be 1.8am / s. The APC controller is filled with process gas O2, and the O2 flow rate is 45sccm. At this time, the vacuum degree is 8.5*10 -3 Pa, continuous coating, the total thickness of the deposited film is 330nm. The refractive index of the film measured by the spectrometer is N=2.22.

[0040] Example 4

[0041] In the I KS-2700 vacuum coating machine, take the transferred composite board and load it onto the umbrella leaf. Close the machine furnace door, rotate the umbrella leaf frame, turn on the vacuum pump of the front stage group, start the vacuum pumping system, mechanical pump EDARDS-NES750 + Roots pump EH4200, measure the vacuum degree and draw it to 5.0*10Pa, open the high vacuum valve, pump the cold pump, start the PLOY COOLD deep cooling and fill the -135℃ refrigerant into the copper tube inside the machine. The copper tube captures water vapor and increases the vacuum degree. When the vacuum degree reaches 2.5*10 -3 Pa, start the 270°E electron gun high voltage, rotate the crucible, and the Ti3O5 crucible reaches the specified position. Gradually increase the electron gun current to 350mA, and the surface temperature of Ti3O5 in the crucible reaches 1850℃. Open the electron gun shielding cover, and the crystal controller monitors the Ti3O5 evaporation rate to be 2.2am / s. The APC controller is filled with process gas O2, and the O2 flow rate is 45sccm. At this time, the vacuum degree is 8.5*10 -3 Pa, continuous coating, the total thickness of the deposited film is 350nm. The refractive index of the film measured by the spectrometer is N=2.20.

[0042] Comparative Example

[0043] In the I KS-2700 vacuum coating machine, take the transferred composite board and load it onto the umbrella leaf, close the machine furnace door, rotate the umbrella leaf frame, turn on the front group vacuum pump, start the vacuum system, mechanical pump EDARDS-NES750, measure the vacuum degree and pump it to 5.0*10Pa, open the high vacuum valve, pump air with the cold pump, and start PLOY COOLD deep cold fills -135℃ refrigerant into the copper tube inside the machine, the copper tube captures water vapor, improves the vacuum degree, waits for the vacuum degree to reach 1.5Pa, starts the 270°E type electron gun high pressure, rotates the crucible, and the Ti3O5 crucible reaches the specified position, gradually increases the electron gun current to 350mA, the surface temperature of Ti3O5 in the crucible reaches 1850℃, opens the electron gun shield, the crystal controller monitors the Ti3O5 evaporation rate of 2am / s, the APC controller fills the process gas O2, the O2 flow rate is 40sccm, the vacuum degree is 2Pa, the coating continues, and the total thickness of the deposited film is 350nm. The spectrometer measures the refractive index of the film N=2.0.

[0044] The original process was used to test the solar radiation performance at 40°C dry heat, using a xenon lamp test device, setting the lamp tube irradiance at 340nm band to 0.55W / M2, wavelength range 300-800nm, maintaining for 20 hours, and then turning off the solar radiation source for 4 hours, this is one cycle; one test cycle is 3 cycles. The 2x2 size determination result is 5B, and the 1x1 size determination result is 4B. The results are as follows:

[0045] 1x1 2x2 Example 1 4B 5B Example 2 4B 5B Example 3 4B 5B Example 4 4B 5B Comparative Example 3B 4B

[0046] The above results show that the method provided by the present invention is helpful for improving the refractive index of the Ti3O5 material when coating the film to resist solar radiation.

[0047] In summary, the present invention provides a method for improving the refractive index of a titanium pentoxide coating layer, comprising: loading a substrate into a vacuum coating device, and evacuating the vacuum coating device; when the vacuum degree reaches 2.5*10 -3 Pa or less, start the electron gun high voltage; heat the titanium pentoxide, and when the temperature reaches 1850°C or above, open the electron gun shielding cover, control the evaporation rate of the titanium pentoxide to be less than or equal to 2.0am / s, control the flow rate of the oxygen, and keep the vacuum degree not higher than 8.5*10 -3 The film is plated under the condition of 1.50 Pa. The invention controls the vacuum degree of the film coating equipment, the evaporation rate of titanium pentoxide and the flow rate of oxygen, so that the refractive index of the obtained titanium pentoxide coating layer is significantly improved.

[0048] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for increasing the refractive index of a titanium pentoxide coating layer, characterized in that: include: Loading the substrate into a vacuum coating device and performing a vacuum treatment on the vacuum coating device; When the vacuum degree reaches 2.5*10 -3 When the voltage is Pa or below, the electron gun high voltage is started; The temperature of titanium pentoxide is raised. When the temperature reaches 1850°C or above, the electron gun shield is opened, the evaporation rate of titanium pentoxide is controlled to be less than or equal to 2.0 am / s, and the flow rate of oxygen is controlled to be filled in a vacuum degree not higher than 8.5*10 -3 Pa coating conditions.

2. The method for improving the refractive index of a titanium pentoxide coating layer according to claim 1, characterized in that: The vacuum coating equipment is subjected to vacuum treatment, specifically comprising: starting a mechanical pump and a Roots pump, measuring the vacuum degree in the vacuum coating equipment, and when the vacuum degree reaches a first preset value, starting a cold pump to evacuate air until the vacuum degree in the vacuum coating equipment reaches 2.5*10 -3 Pa and below.

3. The method for improving the refractive index of a titanium pentoxide coating layer according to claim 2, characterized in that: The first preset value is 5.0*10Pa.

4. The method for improving the refractive index of a titanium pentoxide coating layer according to claim 1, characterized in that: The flow rate of the oxygen gas is 35-45 sccm.

5. The method for improving the refractive index of a titanium pentoxide coating layer according to claim 1, characterized in that: The substrate is a composite plate after transfer; before coating the surface of the substrate, the substrate is firstly cleaned by ion source.

6. The method for improving the refractive index of a titanium pentoxide coating layer according to claim 1, characterized in that: The vacuum degree is not higher than 8.5*10 -3 The film is deposited under the condition of 2.5477 W / m2 Pa and the thickness of the film is 280-320 nm.

7. The method for improving the refractive index of a titanium pentoxide coating layer according to claim 1, characterized in that: The power of the titanium pentoxide target source is 2.1-2.2KW.

8. The method for improving the refractive index of a titanium pentoxide coating layer according to claim 1, characterized in that: The evaporation rate of the titanium pentoxide is 1.8-2.0 am / s.

9. The method for improving the refractive index of a titanium pentoxide coating layer according to claim 1, characterized in that: The vacuum coating equipment is an IKS-2700 vacuum coating machine; the electron gun is a 270°E type electron gun.