Film thickness measuring device for vacuum coating

Abstract

The invention relates to the technical field of film thickness measuring devices, in particular to a film thickness measuring device for vacuum coating, which comprises a device body provided with a crystal oscillator seat for placing a crystal oscillator probe and a driving source for driving the crystal oscillator seat to rotate, and is characterized in that the device body comprises a cooling assembly fixedly arranged in a coating chamber; the cooling assembly covers the outer side of the crystal oscillator seat, a cooling flow channel filled with cooling liquid is arranged in the cooling assembly, the cooling flow channel is connected with external cooling equipment to realize circulating cooling, the cooling assembly comprises a cooling lower cover communicated with the cooling flow channel, and the cooling lower cover is provided with an opening communicated with the coating chamber. The influence of temperature fluctuation on the frequency of the crystal oscillator is effectively suppressed in an active cooling mode, the precision of film thickness measurement is improved, the opening design of the cooling lower cover ensures that the crystal oscillator can be exposed in a film coating environment during measurement, and the dual functions of cooling and communicating the crystal oscillator with the film coating environment are achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of film thickness measuring devices, in particular to a film thickness measuring device for vacuum coating. BACKGROUND

[0002] The filter is used for selecting specific wavelength light to pass in the optical imaging system, and the optical performance of the filter is determined by the surface coating layer. The filter coating is formed by depositing specific optical material on the surface of the filter layer by layer through the vacuum coating technology, and the thickness of the film layer directly affects the optical characteristics of the filter.

[0003] In order to accurately control the thickness of the film layer, the industry generally uses the crystal vibration frequency monitoring method. The crystal vibration piece is placed in the coating chamber, and the film layer raw material will adhere to the surface of the crystal vibration piece during the deposition process, which causes the mass of the crystal vibration piece to increase, and then the inherent vibration frequency of the crystal vibration piece is linearly attenuated. By monitoring the frequency change of the crystal vibration piece and combining the film material density and other parameters conversion, the cumulative thickness of the film layer per unit time can be accurately obtained, so as to realize the accurate control of the coating process.

[0004] The current mainstream crystal vibration measurement adopts a rotary multi-probe structure, including a rotating seat, a fixed seat and a driving source. The rotating seat is rotatably installed in the coating chamber, the fixed seat is fixedly installed in the coating chamber, the rotating seat is driven to rotate by the driving source, a plurality of crystal vibration probes are placed on the rotating seat, each crystal vibration probe is internally provided with a crystal vibration piece, a through hole is formed in the fixed seat and is opposite to the crystal vibration probe, the surface of the crystal vibration piece is exposed to the coating environment through the through hole, and the film material is adhered to the surface of the crystal vibration piece through the through hole. The crystal vibration probe monitors the change of the vibration frequency of the crystal vibration piece in real time. When the film layer deposited on the surface of the crystal vibration piece reaches the preset thickness or the performance attenuation reaches the critical value, the driving source is started to drive the rotating seat to rotate, so that the next non-working crystal vibration probe is aligned with the through hole position to continue the measurement, thereby prolonging the overall monitoring period.

[0005] However, the film layer raw material needs to be converted into gaseous film material by heating source, and this process will produce a large amount of radiant heat, which will cause the temperature inside the coating chamber to fluctuate. The temperature change will interfere with the stability of the vibration frequency of the crystal vibration piece, so that the frequency change cannot accurately reflect the actual thickness of the film layer, causing measurement deviation.

[0006] Therefore, a film thickness measuring device for vacuum coating is needed to solve the problem that the temperature fluctuation in the vacuum coating process causes the frequency fluctuation of the crystal vibration piece, thereby affecting the film thickness measurement accuracy. SUMMARY

[0007] In order to realize the water cooling of other structures of the crystal vibration probe to indirectly realize the stable control of the temperature of the crystal vibration piece, the application provides a film thickness measuring device for vacuum coating.

[0008] The application provides a vacuum coating film thickness measuring device. The application provides a vacuum coating film thickness measuring device.

[0009] The cooling assembly is wrapped outside the crystal oscillator seat to provide a relatively stable low-temperature environment for the crystal oscillator seat and its internal structure, effectively isolates the radiant heat interference in the coating chamber caused by the heating source, reduces the frequency fluctuation of the crystal oscillator caused by heat, and effectively removes the heat around the crystal oscillator seat and the crystal oscillator probe through the external cooling device to circulate and cool the cooling liquid in the cooling flow channel, thereby maintaining the stability of the working temperature of the crystal oscillator.

[0010] Optionally, the cooling assembly further comprises a cooling outer wall and a cooling upper cover, the two ends of the cooling outer wall are respectively connected with the cooling upper cover and the cooling lower cover, and the cooling outer wall, the cooling upper cover and the cooling lower cover jointly form a heat insulation cavity.

[0011] The cooling outer wall, the cooling upper cover and the cooling lower cover jointly form a heat insulation cavity to further block the conduction path of external heat to the crystal oscillator seat, and cooperate with the circulating cooling liquid in the cooling flow channel to form a double temperature control structure of active cooling and passive heat insulation, thereby significantly improving the thermal stability of the environment around the crystal oscillator seat.

[0012] Optionally, the cooling lower cover is internally provided with a cooling flow channel in communication with the interior of the cooling outer wall, and the cooling flow channel is arranged around the periphery of the opening.

[0013] By adopting the above technical scheme, the cooling flow channel is in communication with the interior of the cooling outer wall, so that the cooling liquid in the interior of the cooling lower cover can continuously circulate, the cooling flow channel is arranged around the periphery of the opening, and when the gaseous film material passes through the opening and is attached to the surface of the crystal oscillator piece, the cooling flow channel cools the peripheral area of the opening, thereby pre-cooling the gaseous film material about to be attached to the surface of the crystal oscillator piece, reducing the initial temperature of the gaseous film material when deposited on the surface of the crystal oscillator piece, and thereby reducing the temperature fluctuation of the crystal oscillator piece.

[0014] Optionally, the device body further comprises a temperature measuring element, the temperature measuring element penetrates through the cooling upper cover and extends to the periphery of the crystal oscillator probe, and the temperature measuring element monitors the temperature of the periphery of the crystal oscillator probe and dynamically adjusts the external cooling device.

[0015] By adopting the above technical scheme, the temperature measuring element can monitor the temperature change of the periphery of the crystal oscillator probe in real time and feed back data to the outside, and the external cooling device dynamically adjusts the flow of the cooling liquid according to the feedback data, so as to accurately control the temperature around the crystal oscillator probe, ensure that the crystal oscillator piece is always in the best temperature range, thereby maintaining the high stability of the frequency of the crystal oscillator piece, and further improving the accuracy of film thickness measurement.

[0016] Optionally, the opening is provided with a tapered flow guide surface, and the tapered flow guide surface is inwardly tapered from the outer edge of the opening.

[0017] By adopting the above technical scheme, the tapered flow guide surface can effectively guide the gaseous film material to flow in a specific direction, reduce the risk of opening blockage caused by the deposition of gaseous film material on the edge of the opening, and the tapered structure can make the gaseous film material more concentratedly guide to the surface of the crystal oscillator piece, improve the deposition efficiency and uniformity, and at the same time, compared with the straight wall structure, the tapered flow guide surface further increases the contact area between the gaseous film material and the inner wall of the opening, enhances the heat exchange effect of the gaseous film material, and helps to further reduce the temperature of the gaseous film material.

[0018] Optionally, a support column is installed between the cooling upper cover and the device body, the crystal oscillator seat is connected with the driving source through a rotating shaft, the rotating shaft penetrates through the cooling upper cover and is fixedly connected with the crystal oscillator seat, and the support column is rotatably sleeved outside the rotating shaft.

[0019] By adopting the above technical scheme, the support column is installed between the cooling upper cover and the device body to provide stable support for the whole cooling assembly, the rotating shaft penetrates through the cooling upper cover and is fixedly connected with the crystal oscillator seat to realize the rotating movement of the crystal oscillator seat under the driving of the driving source, and the support column is rotatably sleeved outside the rotating shaft to provide radial limiting and support for the rotating shaft.

[0020] Optionally, the rotating shaft is internally provided with a gas passage in communication with an external gas source, an outlet end of the gas passage is located between the crystal oscillator seat and the cooling lower cover, and the outlet end of the gas passage is provided with a micro gas port, and the micro gas port outputs inert gas in a circumferential direction to isolate residual gaseous film material between the crystal oscillator seat and the cooling lower cover.

[0021] By adopting the above technical solution, the crystal oscillator seat rotates in the cooling assembly, and there is a small gap between the crystal oscillator seat and the cooling lower cover. Most of the gaseous film material entering from the opening adheres to the surface of the crystal oscillator piece, but a small amount of residual gaseous film material may enter the gap and adhere to the surface of other non-working crystal oscillator pieces, which affects the temperature of other crystal oscillator pieces and causes interference with subsequent film thickness measurement. By introducing inert gas into the gas passage in the rotating shaft, the inert gas is sprayed out of the micro gas port in a circumferential direction to form a uniform air curtain barrier between the crystal oscillator seat and the cooling lower cover, effectively blocking the residual gaseous film material from entering the gap. As the rotating shaft continues to rotate, the disturbance and discharge of the residual gaseous film material are enhanced, and the risk of jamming between the crystal oscillator seat and the cooling lower cover due to deposition of gaseous film material is also reduced, ensuring smooth rotation of the crystal oscillator seat.

[0022] Optionally, the crystal oscillator seat is provided with a first coating, and the inner wall of the cooling lower cover is provided with a second coating corresponding to the first coating. The first coating is used to emit thermal radiation to the second coating, and the second coating is used to absorb the thermal radiation emitted by the first coating. A thermal radiation shielding structure is formed between the first coating and the second coating.

[0023] By adopting the above technical solution, the thermal radiation of the crystal oscillator seat is transmitted to the second coating through the first coating, achieving efficient radiation heat exchange, reducing the accumulation of heat in the crystal oscillator seat, and avoiding measurement deviation of the film layer caused by local temperature rise. The thermal radiation shielding structure between the first coating and the second coating effectively directs the heat of the crystal oscillator seat to the cooling lower cover, and the cooling lower cover further dissipates heat through the cooling flow channel and the cooling cycle, thereby maintaining the temperature of the crystal oscillator seat stable.

[0024] In summary, the present application has at least one of the following beneficial technical effects: 1. The device effectively suppresses the influence of temperature fluctuation on the frequency of the crystal oscillator piece through active cooling, significantly improves the accuracy of film thickness measurement, and the opening design of the cooling lower cover of the cooling assembly ensures that the crystal oscillator piece can be exposed to the coating environment during measurement, so that the gaseous film material can be deposited on the surface of the crystal oscillator piece smoothly. During the non-measurement period, the crystal oscillator piece is effectively shielded by the cooling assembly to avoid pre-heating, thereby reducing the influence of heat accumulation on the frequency stability of the crystal oscillator piece. The cooling lower cover is in communication with the cooling flow channel, and has the dual functions of cooling and connecting the crystal oscillator piece with the coating environment. 2. The cooling flow channel is in communication with the cooling outer wall, so that the cooling liquid inside the cooling lower cover can continuously circulate, the cooling flow channel is arranged around the opening, when the gaseous film material passes through the opening and adheres to the surface of the crystal vibration piece, the cooling flow channel cools the surrounding area of the opening, thereby pre-cooling the gaseous film material about to adhere to the surface of the crystal vibration piece, reducing the initial temperature when the gaseous film material is deposited on the surface of the crystal vibration piece, thereby reducing the temperature fluctuation of the crystal vibration piece; 3. By introducing inert gas into the gas channel inside the rotating shaft, and spraying it through the micro gas port, a uniform air curtain barrier is formed between the crystal vibration seat and the cooling lower cover, effectively blocking the residual gaseous film material from entering the gap. With the continuous rotation of the rotating shaft, the disturbance and discharge of the residual gaseous film material are enhanced, and the risk of jamming between the crystal vibration seat and the cooling lower cover due to deposition of gaseous film material is also reduced, ensuring smooth rotation of the crystal vibration seat. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The structure of the embodiment of the present application is a schematic diagram for showing the overall structure of the device body; Figure 2 The cross-sectional view of the embodiment of the present application is used to show the structure inside the device body; Figure 3 The partial cross-section of the embodiment of the present application is used to show the specific structure of the cooling assembly; Figure 1 Figure 4 The partial cross-section of the embodiment of the present application is used to show the specific structure of the cooling flow channel; Figure 2 Figure 5 The control flow chart in the embodiment of the present application.

[0026] Reference signs: 1, device body; 111, signal line; 112, temperature measuring element; 113, external cooling equipment; 2, crystal vibration seat; 211, first mounting layer; 221, second mounting layer; 231, crystal vibration probe; 241, crystal vibration piece; 3, cooling flow channel; 4, cooling assembly; 411, cooling upper cover; 421, cooling outer wall; 422, water inlet pipe; 423, water outlet pipe; 431, cooling lower cover; 432, opening; 433, connecting hose; 434, cooling flow channel; 5, heat insulation cavity; 6, support column; 7, rotating shaft; 711, gas channel; 712, external gas source; 713, micro gas port; 8, driving source. DETAILED DESCRIPTION

[0027] The following will be described in detail in combination with the Figures 1-5 The present application will be further described in detail.

[0028] Embodiment: A vacuum coating film thickness measuring device, referring to Figure 1 and Figure 2 ​​, including the device body 1, the device body 1 is installed on the crystal oscillator seat 2, the cooling assembly 4 is fixedly installed on the device body 1, and the cooling assembly 4 is wrapped outside the crystal oscillator seat 2, the crystal oscillator seat 2 is isolated from the high-temperature environment in the coating chamber, the cooling assembly 4 is provided with a cooling flow channel 3 inside, the cooling flow channel 3 is connected with the external cooling equipment 113 outside the device body 1, the cooling liquid is transported into the cooling flow channel 3 through the external cooling equipment 113, the cooling liquid circulates in the cooling flow channel 3, continuously absorbs the heat conducted by the crystal oscillator seat 2 and is discharged to the outside, a plurality of crystal oscillator probes 231 are placed in the crystal oscillator seat 2, the cooling assembly 4 includes a cooling lower cover 431, the cooling lower cover 431 is located below the crystal oscillator probe 231, the cooling lower cover 431 is provided with an opening 432 penetrating the inside and outside of the cooling lower cover 431, the device body 1 is also provided with a driving source 8, the crystal oscillator seat 2 is in transmission connection with the driving source 8, and the crystal oscillator seat 2 is further provided with a plurality of crystal oscillator probes 231 Figure 3 , the crystal oscillator seat 2 is driven by the driving source 8 to rotate, so that the crystal oscillator chip 241 on the crystal oscillator probe 231 is aligned with the opening 432 in turn, each crystal oscillator chip 241 is communicated with the coating chamber in turn to facilitate smooth film thickness measurement, when a certain crystal oscillator chip 241 completes measurement, the driving source 8 controls the crystal oscillator seat 2 to rotate to the next crystal oscillator chip 241 aligned with the opening 432, and the next round of film thickness measurement is continued, the measurement efficiency and precision are improved, and meanwhile, the performance of the crystal oscillator chip 241 is prevented from being reduced due to the influence of high temperature, the cooling lower cover 431 is communicated with the cooling flow channel 3, and has the functions of cooling and connecting the crystal oscillator chip 241 with the coating chamber.

[0029] Reference Figure 2 and Figure 3The cooling assembly 4 further comprises a cooling upper cover 411 and a cooling outer wall 421, the cooling upper cover 411 and the cooling outer wall 421 are respectively located above and on the side of the crystal oscillator seat 2, the cooling outer wall 421 is in communication with the cooling upper cover 411 and the cooling lower cover 431, so that the cooling liquid in the cooling flow channel 3 can fully cover the upper, lower and side surfaces of the crystal oscillator seat 2, forming a full-range thermal isolation barrier, the cooling upper cover 411, the cooling outer wall 421 and the cooling lower cover 431 jointly constitute a heat insulation cavity 5, so that the crystal oscillator seat 2 is in a stable environment, the cooling lower cover 431 is internally provided with a cooling flow channel 434 in communication with the cooling flow channel 3, the cooling flow channel 434 is annularly distributed on the side of the opening 432, while the gaseous film material is attached to the surface of the crystal oscillator piece 241 through the opening 432, the gaseous film material transmits heat to the inner wall of the opening 432, the cooling flow channel 434 continuously carries away the heat accumulated in the opening 432 area, thereby effectively reducing the temperature of the gaseous film material attached to the surface of the crystal oscillator piece 241, thereby reducing the film thickness measurement error caused by the influence of the gaseous film material temperature on the crystal oscillator piece 241, and improving the data accuracy, the inner wall of the opening 432 is provided with a tapered flow guide surface, the shape of the opening 432 is in a tapered shape, guiding the gaseous film material to enter and uniformly attach to the surface of the crystal oscillator piece 241, reducing the accumulation of the gaseous film material at the inlet end of the opening 432, avoiding airflow turbulence and uneven film layer distribution caused by accumulation, and the tapered flow guide surface can also increase the contact area of the gaseous film material and the inner wall of the opening 432, further strengthening the heat conduction efficiency.

[0030] Reference Figure 2 and Figure 3 The cooling assembly 4 is installed on the device body 1 through a support column 6, one end of the support column 6 is fixed to the top surface of the cooling upper cover 411, the other end is connected to the inner wall of the device body 1, the crystal oscillator seat 2 and the driving source 8 are drivingly connected through a rotating shaft 7, in this embodiment, the driving source 8 comprises a motor, the output end of the driving source 8 is fixedly connected with the rotating shaft 7, the rotating shaft 7 is rotatably installed in the support column 6 through a bearing, ensuring that the crystal oscillator seat 2 rotates stably, and the rotating shaft 7 is arranged inside the support column 6, so that the structure is more compact, and the space in the film plating chamber is effectively saved, and the connection between the rotating shaft 7 and the cooling upper cover 411 is provided with a sealing bearing and a waterproof sealing ring, so that the cooling liquid in the cooling flow channel 3 cannot leak along the rotating shaft 7, and the stability of the temperature inside the heat insulation cavity 5 is enhanced.

[0031] Reference Figure 2 and Figure 3When different crystal vibration pieces 241 are switched for measurement, the driving source 8 drives the crystal vibration seat 2 to rotate at a preset frequency, and a gap exists between the crystal vibration seat 2 and the cooling lower cover 431 to ensure smooth rotation of the crystal vibration seat 2. The rotating shaft 7 is internally provided with a gas passage 711, and an external gas source 712 is externally installed. The gas outlet end of the gas passage 711 is located at the gap between the crystal vibration seat 2 and the cooling lower cover 431. The end of the rotating shaft 7 is provided with a plurality of micro gas ports 713 distributed in the circumferential direction. One end of the gas passage 711 is in communication with the external gas source 712, and the other end is connected with the gap between the crystal vibration seat 2 and the cooling lower cover 431 through the micro gas ports 713. The external gas source 712 continuously introduces inert gas into the gap through the gas passage 711 and the micro gas ports 713. During the deposition of the gaseous film material, most of the gaseous film material is attached to the surface of the crystal vibration piece 241, and a small part of the scattered gaseous film material enters the gap between the crystal vibration seat 2 and the cooling lower cover 431. The inert gas forms a dynamic gas seal barrier in the gap, effectively blocking the scattered gaseous film material from attaching to the surfaces of other crystal vibration pieces 241 that are not being measured. On the one hand, this avoids premature contamination of the non-working crystal vibration pieces 241, ensuring the accuracy of the measurement of each crystal vibration piece 241. On the other hand, it avoids the influence of gaseous film material on the temperature of other crystal vibration pieces 241 and the temperature around the measured crystal vibration piece 241, thereby maintaining the stability of the thermal environment around the crystal vibration piece 241 and further reducing measurement errors.

[0032] Reference Figure 2 and Figure 3 The crystal vibration seat 2 includes a first mounting layer 211 and a second mounting layer 221. The first mounting layer 211 is detachably mounted on the second mounting layer 221. The first mounting layer 211 mounts the main structure of the crystal vibration probe 231. The second mounting layer 221 is provided with a plurality of stepped holes for placing a plurality of crystal vibration pieces 241. After all the crystal vibration pieces 241 are measured, the second mounting layer 221 can be detached from the first mounting layer 211 and replaced with new crystal vibration pieces 241 for overall maintenance and batch replacement. The upper surface of the first mounting layer 211 is coated with a first coating layer, and the lower surface of the cooling lower cover 431 is coated with a second coating layer. The first coating layer is a high-temperature and high-radiation coating layer containing yttrium oxide and zirconium oxide, which can effectively and continuously emit thermal radiation to the cooling lower cover 431. The second coating layer is a metal composite absorption coating layer with high thermal absorption rate and rapid heat conduction characteristics, which can efficiently receive the heat radiated by the first coating layer and quickly transfer it to the cooling flow channel 3 inside the cooling lower cover 431, thereby reducing the ambient temperature of the crystal vibration piece 241.

[0033] Reference Figure 2 and Figure 3The cooling outer wall 421 is connected with an inlet pipe 422 and an outlet pipe 423. The inlet pipe 422 is connected with the output end of the external cooling device 113, and the outlet pipe 423 is connected with the return end of the external cooling device 113, forming a closed circulation loop. The cooling lower cover 431 is rotatably installed on the cooling outer wall 421. When the crystal vibration piece 241 is replaced, the cooling lower cover 431 can be independently rotated around the rotating shaft, so that the second mounting layer 221 can be taken out from the bottom for replacing the crystal vibration piece 241, avoiding interference with the upper structure. In combination with Figure 4 The cooling lower cover 431 is provided with two connecting hoses 433 at the rotating shaft. One end of one of the connecting hoses 433 is connected with the inlet end of the cooling flow channel 434 in the cooling lower cover 431, and the other end is connected with the cooling outer wall 421 near the inlet pipe 422. One end of the other connecting hose 433 is connected with the outlet end of the cooling flow channel 434 in the cooling lower cover 431, and the other end is connected with the cooling outer wall 421 near the outlet pipe 423. The connecting hoses 433 can be freely stretched and contracted synchronously with the cooling lower cover 431, ensuring that the cooling flow channel 3 is always unblocked during rotation. The connection between the cooling lower cover 431 and the cooling outer wall 421 is provided with a sealing structure, thereby ensuring the airtightness and thermal stability of the heat insulation cavity 5.

[0034] Referring to Figure 1 and Figure 2 The device body 1 further comprises a signal line 111 and a temperature measuring element 112. The signal line 111 is fixed on the device body 1, in combination with Figure 3 One end of the signal line 111 extends to the side of the crystal vibration probe 231 and is electrically connected with the crystal vibration probe 231. The end of the signal line 111 is lower than the top end of the crystal vibration probe 231. With the rotation of the crystal vibration seat 2, the signal line 111 is always stably electrically connected with the crystal vibration probe 231. The other end of the signal line 111 is electrically connected with an external signal processing system, and the frequency response signal of the crystal vibration piece 241 is transmitted in real time, ensuring the continuity and accuracy of the measurement data.

[0035] Referring to Figure 1 and Figure 2 The temperature measuring element 112 is fixedly installed on the device body 1. One end of the temperature measuring element 112 is electrically connected with a temperature measuring system outside the coating chamber, and the other end penetrates through the cooling upper cover 411 and extends to the side of the crystal vibration probe 231. With the rotation of the crystal vibration seat 2, the temperature measuring element 112 monitors the temperature change near each crystal vibration piece 241 in real time. The end of the temperature measuring element 112 is higher than the crystal vibration probe 231, avoiding interference or collision with the crystal vibration probe 231 during the rotation of the crystal vibration seat 2, ensuring the safety and stability of the measurement process, in combination with Figure 5The temperature measuring element 112 feeds back the temperature data to the external temperature measuring system after monitoring the temperature change around the crystal probe 231, the temperature measuring system analyzes and processes the received signals, judges whether the temperature of the crystal sheet 241 is in the ideal measurement range, and transmits the judgment result to the control system in real time, if the temperature exceeds the preset threshold, the control system automatically adjusts the flow of the cooling liquid in the cooling channel 3 to dynamically balance the temperature around the crystal sheet 241, and ensure that the working temperature is always stable in the optimal measurement range, forming a closed-loop control system from the temperature measuring module-temperature control module-cooling module-crystal module, and realizing high-precision regulation and control of the temperature field of the crystal sheet 241 during the coating process.

[0036] The implementation principle of the embodiment of the application is that the cooling assembly 4 covers the crystal holder 2 in all directions through the cooling upper cover 411, the cooling outer wall 421 and the cooling lower cover 431, the external cooling device 113 delivers cooling liquid to the cooling channel 3 through the water inlet pipe 422, and cooperates with the heat radiation heat exchange between the first mounting layer 211 of the crystal holder 2 and the cooling lower cover 431 to double high-efficiency remove the heat of the crystal holder 2. The annular cooling flow channel 434 around the opening 432 of the cooling lower cover 431 can also absorb the heat transferred by the gaseous film material in a targeted manner, further stabilizing the temperature environment of the crystal sheet 241; the driving source 8 drives the crystal holder 2 to rotate stably through the rotating shaft 7, the inert gas is introduced into the gap between the crystal holder 2 and the cooling lower cover 431 through the gas passage 711 in the rotating shaft 7, a dynamic gas seal is formed, and the temperature influence around the crystal sheet 241 is further reduced; the signal line 111 is stably connected with the crystal probe 231 at all times, and transmits the frequency response signal to the external system in real time, the temperature measuring element 112 monitors the temperature around the crystal sheet 241 and feeds back, if the temperature exceeds the threshold, the control system automatically adjusts the flow of the cooling liquid, dynamically balances the temperature, when the crystal sheet 241 is replaced, the cooling lower cover 431 can be independently rotated, the second mounting layer 221 can be detached, the connecting hose 433 ensures that the cooling channel 3 is unobstructed during rotation, and the sealing structure maintains the airtightness and thermal stability of the heat insulation cavity 5.

[0037] The above are preferred embodiments of the application, and do not limit the protection scope of the application, therefore: any equivalent changes made according to the structure, shape, principle of the application should be covered within the protection scope of the application.

Claims

1. A device for measuring film thickness in vacuum coating, comprising a device body (1), wherein a crystal oscillator base (2) for placing a crystal oscillator probe (231) and a drive source (8) for driving the crystal oscillator base (2) to rotate are mounted on the device body (1), characterized in that: The device body (1) includes a cooling assembly (4) fixedly installed in the coating chamber. The cooling assembly (4) covers the outside of the crystal oscillator base (2). The cooling assembly (4) has a cooling channel (3) filled with coolant inside. The cooling channel (3) is connected to an external cooling device (113) to achieve circulating cooling. The cooling assembly (4) includes a cooling lower cover (431) communicating with the cooling channel (3). The cooling lower cover (431) has an opening (432) communicating with the coating chamber. The driving source (8) drives the crystal oscillator base (2) to rotate so that the crystal oscillator plate (241) of the crystal oscillator probe (231) is aligned with the opening (432) in sequence.

2. The device for measuring film thickness in vacuum coating according to claim 1, characterized in that: The cooling assembly (4) further includes a cooling outer wall (421) and a cooling upper cover (411). The two ends of the cooling outer wall (421) are respectively connected to the interior of the cooling upper cover (411) and the cooling lower cover (431). The cooling outer wall (421), the cooling upper cover (411) and the cooling lower cover (431) together form a heat insulation cavity (5).

3. The device for measuring film thickness in vacuum coating according to claim 2, characterized in that: The cooling lower cover (431) is provided with a cooling channel (434) that communicates with the interior of the cooling outer wall (421), and the cooling channel (434) is arranged around the opening (432).

4. The device for measuring film thickness in vacuum coating according to claim 2, characterized in that: The device body (1) also includes a temperature measuring element (112), which penetrates the cooling cover (411) and extends to the periphery of the crystal oscillator probe (231). The temperature measuring element (112) monitors the temperature around the crystal oscillator probe (231) and dynamically adjusts the external cooling device (113).

5. The device for measuring film thickness in vacuum coating according to claim 1, characterized in that: The opening (432) is provided with a tapered guide surface, which tapers inward from the outer edge of the opening (432).

6. The device for measuring film thickness in vacuum coating according to claim 2, characterized in that: A support column (6) is installed between the cooling cover (411) and the device body (1). The crystal oscillator (2) is connected to the drive source (8) through a rotating shaft (7). The rotating shaft (7) passes through the cooling cover (411) and is fixedly connected to the crystal oscillator (2). The support column (6) is rotatably sleeved outside the rotating shaft (7).

7. The device for measuring film thickness in vacuum coating according to claim 6, characterized in that: The rotating shaft (7) is provided with a gas channel (711) that communicates with an external gas source (712). The gas outlet of the gas channel (711) is located between the crystal oscillator (2) and the cooling lower cover (431). The gas outlet of the gas channel (711) is provided with a miniature gas port (713). The miniature gas port (713) outputs inert gas circumferentially to isolate the residual gaseous film between the crystal oscillator (2) and the cooling lower cover (431).

8. The device for measuring film thickness in vacuum coating according to claim 1, characterized in that: The crystal oscillator base (2) is provided with a first coating, and the inner wall of the cooling lower cover (431) is provided with a second coating corresponding to the first coating. The first coating is used to emit thermal radiation to the second coating, and the second coating is used to absorb the thermal radiation emitted by the first coating. A thermal radiation shielding structure is formed between the first coating and the second coating.

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