On-line full wavelength detection system and method for continuous vacuum coating

Abstract

The application discloses an online full-wavelength detection system for continuous vacuum coating, a transfer unit is used for conveying a coated sample to a next vacuum coating unit, the transfer unit can convey the coated sample to a specified position of a detection module, and light emitted by a light source module enters a light collecting mechanism after passing through the coated sample. The application can satisfy online full-wavelength detection of continuous coating, can detect optical performance changes after coating in real time, and then adjust optical coating parameters to achieve ideal optical coating effect. The method can greatly improve the yield of multilayer continuous coating. Meanwhile, the second window of the light collecting mechanism and the first window of the light source module are arranged to be inclined at a specified angle, so that reflected light on the upper surface and the lower surface of the coated sample can be effectively prevented from entering the integrating sphere, background interference is effectively reduced, sensitivity is improved, and the optical differences of the coated sample after coating of each layer can be effectively found, so that parameter guidance for the next layer of coating is provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vacuum coating, in particular to an online full-wavelength detection system and method for continuous vacuum coating. BACKGROUND

[0002] Vacuum coating technology is a technology that uses physical and chemical reactions in a vacuum environment to evaporate a specific material (such as metal, silicon, carbon, etc.) onto a surface to form a thin film. Vacuum coating technology can change the physical properties of the surface, such as optical properties, electrical properties, thermal properties, etc., thereby improving the performance of the material.

[0003] Through vacuum coating technology, various optical properties of the lens can be significantly improved, but various conditions during the coating process will affect the coating thickness, so the coating thickness of the lens needs to be detected to effectively guide the subsequent coating process. Therefore, quality inspection equipment that can detect the coating thickness appears on the market, such as CN113248157A "Coating process of optical glass", which records "step S4, after the vacuum coating unit is operated, the coated optical glass is conveyed to the quality inspection unit by the conveying unit, and after the quality inspection unit detects that it is qualified, it is transmitted to the qualified unit." However, this method needs to be detected after being filled with air, and the product detected by the quality inspection unit is the final product. In order to meet higher performance requirements, one layer of coating often cannot meet the requirements, and usually several layers to dozens of layers of coating need to be continuously coated, so detecting only the final coating thickness cannot effectively guide production.

[0004] At the same time, the thickness of each coating during continuous vacuum coating is smaller, and each layer of coating is usually only tens to hundreds of nanometers thick, so the precision requirement of the detection equipment is very high. Therefore, a high-precision detection system is needed to monitor the optical performance status or film thickness of the lens after each coating in real time in a vacuum environment. SUMMARY

[0005] In view of the above problems, the present application aims to provide an online full-wavelength detection system and method for continuous vacuum coating.

[0006] To achieve this technical purpose, the present application provides an online full-wavelength detection system for continuous vacuum coating, which comprises one or more vacuum coating units arranged in sequence for continuous coating in a vacuum chamber, and a transfer unit and a detection module are further provided outside the vacuum coating unit for conveying the coated sample to the next vacuum coating unit.

[0007] The detection module is composed of a light source module, a collimating mechanism, a light collecting mechanism, and a spectrometer. The transfer unit can convey the coated sample to a specified position between the light source module and the light collecting mechanism. The light emitted by the light source module enters the light collecting mechanism after passing through the coated sample.

[0008] As preferred, the transmission unit is also located inside the vacuum chamber, the light source module and the light collecting mechanism are both arranged outside the vacuum chamber, the vacuum chamber is provided with a first window and a second window, the first window is provided with a first lens with a sealing rubber ring, and the second window is provided with a second lens with a sealing rubber ring, the light emitted by the light source module enters the vacuum chamber through the first lens, and the light collecting mechanism can collect the corresponding light passing through the second lens.

[0009] Wherein the first lens and the second lens are not parallel.

[0010] As preferred, the vacuum chamber is provided with a first mounting groove and a second mounting groove in periscope structure, wherein the emitting optical fiber of the light source module is arranged at the bottom of the first mounting groove, and the light collecting optical fiber of the light collecting mechanism is arranged at the bottom of the second mounting groove, and the emitting optical fiber and the light collecting optical fiber are both located outside the vacuum chamber.

[0011] The first lens is located at the lower side of the first mounting groove, and the second lens is located at the lower side of the second mounting groove, and the minimum distance between the first lens and the second lens is less than or equal to 20 cm.

[0012] As preferred, the light emitted by the light source module is perpendicular to the surface of the coated sample, and the side of the first lens and the second lens close to the coated sample is arranged away from the nearest vacuum coating unit.

[0013] A detection method using an online full-wavelength detection system for continuous vacuum coating, after the coated sample completes the coating of the corresponding layer in a certain vacuum coating unit, the coated sample enters the detection module for detection, and the specific steps are as follows:

[0014] S1, installation, the light source module and the light collecting mechanism are installed at the designated position on one side of the vacuum coating unit, the angle of the light emitted by the light source module is adjusted to be perpendicular to the surface of the coated sample, the light collecting mechanism is adjusted to be aligned with the center of the light, and the airtightness of the light source module and the light collecting mechanism is ensured to be good;

[0015] S2, debugging, fine-tuning the first lens and the second lens to the appropriate angle;

[0016] S3, online detection, obtaining the initial information of the coated sample before coating, the coated sample is conveyed to the i-th vacuum coating unit by the transmission unit, the i-th layer of coating is completed according to the specified parameters, and then the transmission unit conveys the coated sample above the light collecting mechanism of the i-th detection module, and the full-wavelength gradient spectrum N i of the coated sample at this time is obtained by the spectrometer, and the film thickness of the corresponding i-th layer is calculated;

[0017] S4, comparative analysis, comparing the full-wavelength gradient spectrum N i with the full-wavelength gradient spectrum N i-1If the spectrum fluctuation is abnormal or the film thickness exceeds the threshold value, it indicates that the i-th vacuum coating unit has an abnormal parameter and needs to be debugged; if the spectrum changes or the film thickness meets the setting, the film coating continues to the i+1-th vacuum coating unit.

[0018] Preferably, the film thickness of the i-th layer is calculated by acquiring the film thickness data of each layer in front of the i-th layer of the same sample according to the transmission and coating time sequence. If one or more layers do not collect film thickness data through the detection unit, the theoretical design film thickness value is called to participate in the operation.

[0019] Preferably, a shielding piece is placed on the light inlet, and a coated sample is placed on the transmission unit between the first lens and the second lens. After starting the light source module, a strong light spot appears on the shielding piece, a first weak light spot is reflected on the upper surface of the coated sample, and a second weak light spot is reflected on the lower surface of the coated sample, ensuring that the strong light spot falls on the position that can be collected by the light inlet.

[0020] The motion direction of the first lens and the coated sample forms an angle α, and the motion direction of the second lens and the coated sample forms an angle β. The angle α of the first lens is adjusted so that the first weak light spot does not appear on the light inlet position. The angle β of the second lens is adjusted so that the second weak light spot does not appear on the light inlet position, and finally the shielding piece on the light inlet is removed.

[0021] Preferably, when the center of the light emitted by the light source module coincides with the center of the light inlet, the angle α satisfies h1*tan2α is greater than D0, and the angle β satisfies h2*tan2β+h3*tan2β is greater than D0,

[0022] Wherein h1 is the distance from the intersection of the light and the first lens to the center of the light inlet, h2 is the distance from the coated sample to the center of the light inlet, and h3 is the vertical distance from the intersection of the light and the second lens to the surface of the coated sample. D0 is the radius of the light inlet.

[0023] Preferably, the coated sample is provided with a metal frame on the outside, and a light transmission groove is formed in a specified position on the metal frame.

[0024] In step S3, when the metal frame of the coated sample passes through the test position of the detection module, data is automatically collected once to obtain the dark spectrum.

[0025] Or add a light blocking piece in the detection module through the transmission unit at irregular times to obtain the dark spectrum.

[0026] Preferably, in step S3, when the light transmission groove of the metal frame of the coated sample passes through the detection position of the detection unit, data is automatically collected once to obtain the reference spectrum.

[0027] Or collect data at irregular times in the detection interval of the coated sample to automatically store the reference spectrum.

[0028] The beneficial effects of this invention are that it can meet the requirements of online full-wavelength detection for continuous coating, and can detect changes in optical performance after coating in real time. This allows for the adjustment of optical coating parameters to achieve the ideal optical coating effect, and the method can significantly improve the yield of multi-layer continuous coating. At the same time, the second window of the light-collecting mechanism and the first window of the light source module are tilted at a specified angle, which can effectively prevent reflected light from the upper and lower surfaces of the coated sample from entering the integrating sphere, thereby effectively reducing background interference, improving sensitivity, and effectively detecting the differences in optical properties of the coated sample after each layer of coating, providing parameter guidance for the next layer of coating. Attached Figure Description

[0029] Figure 1 This is a reference optical path diagram for the first weak light spot of the present invention;

[0030] Figure 2 This is a reference optical path diagram for the second weak light spot of the present invention;

[0031] Figure 3 This is a schematic diagram of the structure of the present invention;

[0032] Figure 4 This is a flowchart of the detection process of the present invention. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0034] like Figures 1-4 As shown, a specific embodiment of the present invention is an online full-wavelength detection system for continuous vacuum coating, including one or more vacuum coating units 1 arranged sequentially for continuous coating within a vacuum chamber 4. A transfer unit and a detection module 3 for transporting the coating sample to the next vacuum coating unit 1 are also provided on the outside of the vacuum coating unit 1. The detection module 3 is composed of a light source module 301, a collimation mechanism, a light-collecting mechanism 302, and a spectrometer. The transfer unit can transport the coating sample 2 to a designated position between the light source module 301 and the light-collecting mechanism 302. The light emitted by the light source module 301 passes through the coating sample 2 and enters the light-collecting mechanism 302.

[0035] The transmission unit is also located inside the vacuum chamber 4, the light source module 301 and the light collecting mechanism 302 are arranged outside the vacuum chamber 4, the vacuum chamber 4 is provided with a first window 401 and a second window 402, the first window 401 is provided with a first lens 403 with a sealing rubber ring, the second window 402 is provided with a second lens 404 with a sealing rubber ring 5, the light emitted by the light source module 301 enters the vacuum chamber 4 through the first lens 403, and the light collecting mechanism 302 can collect the corresponding light passing through the second lens 404; wherein the first lens 403 and the second lens 404 are not parallel.

[0036] The vacuum chamber 4 is provided with a first mounting groove 405 and a second mounting groove 406 in a periscope structure, wherein the emitting optical fiber of the light source module 301 is arranged at the bottom of the first mounting groove 405, and the light collecting optical fiber of the light collecting mechanism 302 is arranged at the bottom of the second mounting groove 406, the emitting optical fiber and the light collecting optical fiber are located outside the vacuum chamber 4, the end face of the emitting optical fiber is opposite to the light inlet of the integrating sphere and is parallel to the surface of the coated sample 2, and the integrating sphere is connected with the light collecting optical fiber to enter the spectrometer; the first lens 403 is located at the lower side of the first mounting groove 405, the second lens 404 is located at the lower side of the second mounting groove 406, and the minimum distance between the first lens 403 and the second lens 404 is less than or equal to 20 cm. The light collecting mechanism 302 is provided with an integrating sphere; the outside of the sample 2 to be coated is wrapped with a metal frame, and a light passing groove is formed in a specified position of the metal frame.

[0037] Since the light source module and the light collecting mechanism of the present application are actually outside the vacuum chamber, the first lens and the second lens mounted on the vacuum chamber are needed for separation; since the first lens and the second lens are introduced, measurement errors may be caused by reflected light, therefore, the first lens and the second lens of the present application are arranged to be not parallel. At the same time, through the periscope design, when the light source module and the light collecting mechanism are placed outside the vacuum chamber, the distance between the light source module and the light collecting mechanism can still be small, usually not more than 20 cm, which can reduce the design difficulty of the collimated light path, and is beneficial to improve the light energy collection efficiency. Under normal circumstances, the width and height of the vacuum chamber are more than 100 cm, so the distance between the light source module, the light collecting mechanism and the coated sample is usually large, and the energy collection efficiency is not high. The periscope structure of the present application makes the light source emitting and collecting modules not need to be placed in the vacuum chamber, which greatly reduces the requirements of equipment selection.

[0038] The light emitted by the light source module is perpendicular to the surface of the coated sample, and the side of the first lens and the second lens close to the coated sample is arranged to be away from the nearest vacuum coating unit, which can effectively reduce the influence of the light entering the light collecting mechanism of the detection unit during vacuum coating, and reduce the measurement error.

[0039] Embodiment one

[0040] A detection method, the specific steps are as follows:

[0041] S1, installation, install the light source module and the light collecting mechanism on the designated position of one side of the vacuum coating unit, adjust the angle of the light emitted by the light source module to be perpendicular to the surface of the coating sample, adjust the light collecting mechanism to be aligned with the center of the light, and ensure that the light source module and the light collecting mechanism have good airtightness;

[0042] S2, debugging, fine-tune the first window and the second window to the appropriate angle; place a shielding piece (which can be white paper) on the light collecting port, and place a coating sample on the transmission unit between the first window and the second window, after starting the light source module, a strong light spot appears on the shielding piece, a first weak light spot is reflected on the upper surface of the coating sample, and a second weak light spot is reflected on the lower surface of the coating sample, and the strong light spot is ensured to fall on the position that can be collected by the light collecting port;

[0043] The first window and the coating sample form an angle α with the direction of movement, and the second window and the coating sample form an angle β with the direction of movement, the angle α of the first window is fine-tuned so that the first weak light spot does not appear on the light collecting port, the angle β of the second window is fine-tuned so that the second weak light spot does not appear on the light collecting port, and finally the shielding piece on the light collecting port is removed.

[0044] In order to facilitate the debugging of step S2, the angles of the first window and the second window need to be analyzed in advance according to the installation environment, when the center of the light emitted by the light source module coincides with the center of the light collecting port, the angle α needs to satisfy: h1*tan2α is greater than D0, and the angle β needs to satisfy: h2*tan2β+h3*tan2β is greater than D0; wherein the thicknesses of the first window, the second window and the coating sample are all small, so their thicknesses are ignored, and therefore the changes in refraction distance caused by the above three materials are ignored.

[0045] Wherein h1 is the distance from the intersection point of the light and the first window to the center of the light collecting port, h2 is the distance from the coating sample to the center of the light collecting port, h3 is the vertical distance from the intersection point of the light and the second window to the surface of the coating sample, and D0 is the radius of the light collecting port.

[0046] S3, online detection, input the initial information of the coating sample before coating, the coating sample is conveyed to the i-th vacuum coating unit by the transmission unit, the i-th layer of coating is completed according to the specified parameters, and then the transmission unit conveys the coating sample to above the light collecting mechanism of the i-th detection module, and the full-wavelength gradient spectrum N i is obtained by the spectrometer.

[0047] When the metal frame of the sample to be plated passes through the test position of the detection module, the dark spectrum is automatically acquired once; or the dark spectrum is acquired by adding a light blocking piece in the detection module through the transmission unit at irregular times. When the light transmission groove of the metal frame of the sample to be plated passes through the detection position of the detection unit, the reference spectrum is automatically acquired once; or the reference spectrum is automatically acquired by collecting data in the detection interval of the sample to be plated.

[0048] S4, comparative analysis, compare the full-wavelength gradient spectrum N i with the full-wavelength gradient spectrum N i-1 If the spectrum fluctuates abnormally, it indicates that the i-th vacuum coating unit needs to be debugged; if the spectrum change meets the setting, the sample continues to be transported to the i+1-th vacuum coating unit for continuous coating.

[0049] The existing coating detection system usually detects the transmittance and other optical parameters of the sample after coating is completed. This method is suitable for use in the case of fewer coating layers, for example, CN113248157B “Coating process of optical glass” records in paragraph 0090 that “the quality inspection unit can be composed of a film thickness measuring instrument, a film flatness measuring instrument, and a light transmittance instrument for film thickness.” It can be seen that this method is only suitable for testing after coating is completed, and cannot meet the needs of online real-time monitoring of continuous coating. If the number of coating layers reaches more than ten, an abnormality in a vacuum coating unit may cause a batch of products to be abnormal, and it is difficult to find out which vacuum coating unit has an abnormality after all the coating is completed, so the debugging and repair are difficult.

[0050] Therefore, real-time online analysis systems have appeared on the market, such as CN113776442A “Spectrum detection device, film thickness real-time monitoring method and system, and vacuum coating machine”, which sets the detection unit in the coating chamber for real-time monitoring, which is used to monitor the coating state of the lens surface at different times in the same vacuum coating unit. Vacuum coating mainly includes three ways: evaporation coating, sputtering coating, and ion plating. However, sputtering coating will produce glow due to high voltage, and plasma itself will also emit light, which will interfere with the detection in the vacuum coating unit.

[0051] The detection system of the present application can analyze and acquire the full-wavelength gradient spectrum of the coated sample immediately after each layer of coating is completed, and the change curve of the light intensity of the coated sample at each wavelength position in the specified wavelength range can be directly observed according to the spectrum. The spectrum can effectively guide the production personnel to judge the change of the spectrum after each layer of coating.

[0052] In the product debugging stage, if the performance of the final product does not meet the standard, the spectrum of each layer of coating can be called to compare and find the abnormal vacuum coating unit, and only the parameter adjustment of the vacuum coating unit is needed, which can greatly save the debugging time and increase the debugging speed.

[0053] In the product production stage, if an abnormality occurs in a vacuum coating unit, the spectrum can provide real-time feedback in the first time, if the error is small, the error can be compensated by subsequent coating parameter adjustment, if the error is large and exceeds the threshold, the abnormality can be found in time and the machine is stopped for maintenance, which can greatly reduce the probability of defective products, and can effectively avoid finding the abnormality after the completion of the coating program of dozens of layers, thereby greatly reducing the production cost.

[0054] The above is only a preferred embodiment of the present application, and is not used to limit the present application, any slight modification, equivalent replacement and improvement of the above embodiment according to the technical essence of the present application shall be included in the protection scope of the technical scheme of the present application.

Claims

1. A method of detection, characterized by: The application relates to an on-line full-wavelength detection system for continuous vacuum coating, which comprises one or more vacuum coating units arranged in sequence for continuous coating in a vacuum chamber, characterized in that a transfer unit and a detection module are further arranged outside the vacuum coating units for conveying the coating sample to the next vacuum coating unit; the detection module is composed of a light source module, a collimating mechanism, a light collecting mechanism and a spectrometer; the transfer unit can convey the coating sample to a specified position between the light source module and the light collecting mechanism; the light emitted by the light source module enters the light collecting mechanism after passing through the coating sample; and the coating sample is detected by the detection module after completing coating of a corresponding layer in a certain vacuum coating unit. The transfer unit is also located inside the vacuum chamber, the light source module and the light collecting mechanism are arranged outside the vacuum chamber, a first window and a second window are arranged on the vacuum chamber, a first lens with a sealing rubber ring is arranged on the first window, a second lens with a sealing rubber ring is arranged on the second window, the light emitted by the light source module enters the vacuum chamber through the first lens, and the light collecting mechanism can collect corresponding light passing through the second lens; wherein the first lens and the second lens are not parallel. A periscope type first mounting groove and a second mounting groove are arranged on the vacuum chamber, an emitting optical fiber of the light source module is arranged at the bottom of the first mounting groove, a light collecting optical fiber of the light collecting mechanism is arranged at the bottom of the second mounting groove, and the emitting optical fiber and the light collecting optical fiber are located outside the vacuum chamber; the light emitted by the light source module is perpendicular to the surface of the coating sample, and the side of the first lens and the second lens close to the coating sample is arranged in a direction away from the nearest vacuum coating unit. The specific steps are as follows: S1, installation, the light source module and the light collecting mechanism are installed at a specified position on one side of the vacuum coating unit, the angle of the light emitted by the light source module is adjusted to be perpendicular to the surface of the coating sample, the light collecting mechanism is adjusted to be aligned with the center of the light, and the airtightness of the light source module and the light collecting mechanism is ensured to be good; S2, debugging, the first lens and the second lens are finely adjusted to reach a proper angle; a shielding piece is placed on the light collecting port, a coating sample is placed on the transfer unit between the first lens and the second lens, and after the light source module is started, a strong light spot appears on the shielding piece, a first weak light spot reflected by the upper surface of the coating sample and a second weak light spot reflected by the lower surface of the coating sample appear, and the strong light spot is ensured to fall on the position that can be collected by the light collecting port; The first lens and the coating sample form an angle alpha with the motion direction, the second lens and the coating sample form an angle beta with the motion direction, the angle alpha of the first lens is finely adjusted so that the first weak light spot does not appear on the position of the light collecting port, the angle beta of the second lens is finely adjusted so that the second weak light spot does not appear on the position of the light collecting port, and finally the shielding piece on the light collecting port is taken out; S3, online detection, obtaining initial information of the coated sample before coating, the coated sample is transported to the i-th vacuum coating unit by the transfer unit, the i-th layer of coating is completed according to the specified parameters, and then the transfer unit transports the coated sample to the top of the light collecting mechanism of the i-th detection module, and the full wavelength gradient spectrum N of the coated sample at this time is obtained by the spectrometer i , and the film thickness of the i-th layer is calculated; the film thickness of the i-th layer needs to obtain the film thickness data of each layer in front of the i-th layer of the same sample through the transfer and coating time sequence, if one or more layers do not collect film thickness data through the detection unit, the theoretical design film thickness value is called to participate in the operation; S4, comparative analysis, comparing the full wavelength gradient spectrum N i with the full wavelength gradient spectrum N i-1 If the spectrum fluctuation is abnormal or the film thickness exceeds the threshold value, it indicates that the i-th vacuum coating unit parameter is abnormal and needs to be debugged; if the spectrum changes or the film thickness meets the setting, the conveying continues to the i+1-th vacuum coating unit for continuous coating. In order to facilitate the debugging of step S2, the angle of the first window and the second window needs to be analyzed in advance according to the installation environment, when the center of the light emitted by the light source module coincides with the center of the light collecting port, the angle alpha needs to satisfy h1*tan2alpha greater than D0, and the angle beta needs to satisfy h2*tan2beta+h3*tan2beta greater than D0. Wherein h1 is the distance from the intersection point of the light and the first lens to the center of the light inlet, h2 is the distance from the coated sample to the center of the light inlet, wherein h3 is the vertical distance from the intersection point of the light and the second lens to the surface of the coated sample, and D0 is the radius of the light inlet.

2. The method of claim 1, wherein: The first lens is located at the lower side of the first mounting groove, the second lens is located at the lower side of the second mounting groove, and the minimum distance between the first lens and the second lens is less than or equal to 20 cm.

3. The method of claim 1, wherein: The outer side of the coated sample is provided with a metal frame, and a light transmission groove is formed at a specified position on the metal frame. In step S3, when the metal frame of the coated sample passes through the test position of the detection module, one data is automatically collected to obtain the dark spectrum. Or add a light blocking piece in the detection module through the transmission unit at irregular time to obtain the dark spectrum.

4. The method of claim 3, wherein: In step S3, when the light transmission groove of the metal frame of the coated sample passes through the detection position of the detection unit, one data is automatically collected to obtain the reference spectrum. Or collect data at irregular time in the detection interval of the coated sample to realize automatic storage of the reference spectrum.

Images