High-temperature-resistant small optical system packaging structure and packaging method

Abstract

The application provides a high-temperature-resistant small optical system packaging structure and a packaging method, and relates to the technical field of optical system packaging. The packaging method first uses high-temperature-resistant ceramics to prepare a high-temperature-resistant ceramic packaging structure base, and then sequentially stacks small optical systems and bonds the small optical systems on the high-temperature-resistant ceramic packaging structure base; then, in a water-free and oxygen-free environment, an indium-based sealing ring is used to complete the welding between the high-temperature-resistant ceramic packaging shell, the indium-based sealing ring and the high-temperature-resistant ceramic packaging structure base at low temperature. The low-temperature welding has small thermal damage to the devices in the small optical system, small residual thermal stress, good physical system airtightness, and the obtained packaging structure can maintain high stability and airtightness in a high-temperature environment. The packaging structure base and the packaging shell of the packaging structure both use high-temperature-resistant ceramics, and the overall thermal expansion of the packaging structure is consistent, so that damage caused by inconsistent stress when working in a high-temperature environment is avoided.

Description

Technical Field

[0001] This invention relates to the field of optical system packaging technology, and in particular to a high-temperature resistant miniature optical system packaging structure and packaging method. Background Technology

[0002] In optical systems, the stability and hermeticity of the packaging structure are critical factors, and the quality of component packaging directly determines the performance of the optical system. Component packaging performed at room temperature is prone to aging and decomposition of the packaging materials when operating in high-temperature environments. Furthermore, under high-temperature conditions, the different coefficients of thermal expansion at the contact surfaces of different packaging materials can easily lead to significant thermal mismatch, resulting in residual thermal stress and directly reducing packaging reliability.

[0003] Currently, plastic-encapsulated electronic components cannot withstand high-temperature environments, while metal-encapsulated electronic components are large and bulky, making them unsuitable for various applications. Although high-temperature / low-temperature co-fired ceramic substrates can be used for hermetically sealed packaging of high-temperature microsystems, their low circuit precision makes them unsuitable for the miniaturization and integration requirements of high-temperature microsystems. In high-temperature environments, traditional packaging structures may not maintain stability and may exhibit hermeticity issues.

[0004] In some applications, such as atomic clock physics systems or other high-precision optical systems, it is necessary to package optical components and related devices into a miniaturized structure while maintaining high stability and hermeticity at high temperatures. However, existing packaging technologies suffer from insufficient stability and poor hermeticity at high temperatures, failing to meet the requirements for long-term use.

[0005] In view of this, it is necessary to design an improved high-temperature resistant miniature optical system packaging structure and packaging method to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a high-temperature resistant miniature optical system packaging structure and packaging method. This packaging method selects a lightweight, high-temperature resistant, corrosion-resistant, and low-thermal-expansion coefficient high-temperature ceramic packaging shell and structural base as packaging materials. The packaging shell and structural base are made of the same packaging material, ensuring consistent thermal expansion of the overall packaging structure and avoiding damage caused by inconsistent stress during operation in high-temperature environments. The packaging structure base and packaging shell are prepared by welding high-temperature resistant ceramic using indium-based sealing rings in an anhydrous and oxygen-free environment. The indium-based sealing rings require low welding temperatures, resulting in minimal thermal damage to other components in the miniature optical system, low residual thermal stress, and good hermeticity of the physical system, enabling long-term operation. The resulting packaging structure maintains high stability and hermeticity in high-temperature environments.

[0007] To achieve the above-mentioned objectives, this invention provides a high-temperature resistant miniature optical system packaging method, comprising the following steps:

[0008] S1, Laser drilling is performed on the ceramic plate to form small-diameter through holes, followed by surface cleaning treatment;

[0009] S2, a Ti / Cu metal layer is deposited on the surface of the ceramic plate obtained in step S1 using a sputtering deposition process as a seed layer;

[0010] S3 uses photolithography and development processes to form a mask pattern, then uses electroplating to fill through holes and thicken the surface copper layer, then uses surface grinding to level the electroplated copper layer, and finally uses surface treatment technology to form a Ni / Au layer.

[0011] S4, remove the dry film and etch the seed layer to obtain a high-temperature resistant ceramic encapsulation structure base;

[0012] S5. Attach the small optical system to the high-temperature ceramic encapsulation structure base with glue.

[0013] S6, place the high-temperature resistant ceramic packaging shell, the high-temperature resistant ceramic packaging structure base with a small optical system obtained in step S5, and the indium-based sealing ring into the vacuum chamber.

[0014] S7. In an anhydrous and oxygen-free environment, open the vacuum-packed indium-based sealing ring, place the indium-based sealing ring on the Ni / Au layer of the high-temperature ceramic packaging structure base, and then cover the high-temperature ceramic packaging shell on the high-temperature ceramic packaging structure base with the indium-based sealing ring placed on it; heat to the welding temperature to completely melt the indium-based sealing ring, thus completing the welding between the high-temperature ceramic packaging shell, the indium-based sealing ring, and the high-temperature ceramic packaging structure base.

[0015] As a further improvement of the present invention, step S7 includes the following process: using a vacuum pump to extract the air from the vacuum chamber, and then filling the vacuum chamber with a protective gas to form an anhydrous and oxygen-free environment to prevent oxidation of the indium-based sealing ring; opening the vacuum-packed indium-based sealing ring in the protective gas atmosphere, and then covering the high-temperature ceramic packaging shell onto the high-temperature ceramic packaging structure base containing the indium-based sealing ring; subsequently, using a vacuum pump to extract the protective gas from the vacuum chamber, controlling the vacuum degree to be less than 10 Pa; and then heating to the welding temperature using a heating stage in the vacuum chamber to completely melt the indium-based sealing ring, thus completing the welding between the high-temperature ceramic packaging shell, the indium-based sealing ring, and the high-temperature ceramic packaging structure base.

[0016] As a further improvement of the present invention, in step S7, the welding temperature is 180-200℃. In practical applications, the specific welding temperature can be adjusted according to the equipment status.

[0017] As a further improvement of the present invention, the protective gas is high-purity nitrogen or high-purity argon.

[0018] As a further improvement of the present invention, the miniature optical system includes a laser source, an optical lens, a light-atom interaction chamber, a heating and temperature control component, a support frame, and a photoelectric signal acquisition device that are stacked and bonded together in sequence.

[0019] As a further improvement of the present invention, in step S1, the diameter of the through hole is 100 μm.

[0020] As a further improvement of the present invention, in step S1, the surface cleaning treatment includes the following process: soaking in acetone and anhydrous ethanol in sequence and ultrasonically vibrating to clean the surface of the ceramic plate, and drying the surface with dry nitrogen gas to remove organic contaminants from the surface of the ceramic plate.

[0021] To achieve the above-mentioned objectives, the present invention also provides a high-temperature resistant miniature optical system packaging structure prepared using the aforementioned scheme, comprising a high-temperature resistant ceramic packaging structure base, a miniature optical system bonded to the high-temperature resistant ceramic packaging structure base, a high-temperature resistant ceramic packaging shell covering the high-temperature resistant ceramic packaging structure base, and an indium-based sealing ring connecting the high-temperature resistant ceramic packaging structure base and the high-temperature resistant ceramic packaging shell; the contact surface between the high-temperature resistant ceramic packaging structure base and the indium-based sealing ring is formed with a Ni / Au layer through surface treatment technology.

[0022] The beneficial effects of this invention are:

[0023] The packaging structure obtained by this invention can maintain high stability and airtightness in high-temperature environments. Low-temperature welding causes less thermal damage to devices in small optical systems, results in less residual thermal stress, and provides good airtightness of the physical system.

[0024] This invention discloses a method for packaging a high-temperature resistant miniature optical system. First, a high-temperature resistant ceramic packaging structure base is fabricated using high-temperature resistant ceramic. Then, a miniature optical system, formed by stacking components sequentially, is bonded to the high-temperature resistant ceramic packaging structure base. Next, in an anhydrous and oxygen-free environment, an indium-based sealing ring is used to weld the high-temperature resistant ceramic packaging shell, the indium-based sealing ring, and the high-temperature resistant ceramic packaging structure base at low temperatures. Low-temperature welding causes minimal thermal damage to the components in the miniature optical system, results in low residual thermal stress, and provides good hermeticity of the physical system. The resulting packaging structure maintains high stability and hermeticity even at high temperatures. Since both the packaging structure base and the packaging shell are made of high-temperature resistant ceramic, the overall thermal expansion of the packaging structure is consistent, avoiding damage caused by inconsistent stress during operation in high-temperature environments.

[0025] 1. This invention uses high-temperature resistant ceramics to prepare the packaging structure base and packaging shell. Based on the high-temperature resistance and corrosion resistance of high-temperature resistant ceramics, the use of high-temperature resistant ceramics to prepare the packaging structure base and packaging shell can achieve high airtightness and high reliability of the physical system in high-temperature environments, and can meet the requirements of long-term use.

[0026] 2. In this invention, both the base and the housing of the encapsulation structure are made of high-temperature resistant ceramics, and the overall thermal expansion of the encapsulation structure is consistent, avoiding damage caused by inconsistent stress when working in a high-temperature environment.

[0027] 3. The packaging method provided by the present invention utilizes an indium-based sealing ring to weld high-temperature resistant ceramics to prepare the packaging structure base and packaging shell during the physical system packaging process. The indium-based sealing ring requires a low welding temperature, resulting in less thermal damage to other devices in the small optical system, less residual thermal stress, good airtightness of the physical system, and the ability to operate for a long time.

[0028] 4. This invention utilizes MEMS processes such as sputtering deposition and photolithography to fabricate electrical connection pins in the high-temperature resistant ceramic packaging structure base, achieving high circuit precision and meeting the requirements for miniaturization and integration of high-temperature microsystems.

[0029] 5. The miniature optical system of this invention is flexible and can be adjusted according to specific optical system requirements, making it applicable to fields such as atomic clocks and magnetometers. Correspondingly, the high-temperature resistant ceramic encapsulation shell is flexible in size and shape, with different heights, and can be adjusted according to the size of the miniature optical system, thereby reducing the volume and weight of the physical system and enabling higher structural density for each component. Attached Figure Description

[0030] Figure 1 This is a perspective view of the high-temperature resistant miniature optical system packaging structure of the present invention.

[0031] Figure 2 This is a schematic diagram of the internal structure of the high-temperature resistant miniature optical system packaging structure of the present invention.

[0032] Figure 3 This is a schematic diagram of the fabrication process for a high-temperature resistant ceramic encapsulation structure base.

[0033] Figure 4 This is a schematic diagram of the high-temperature resistant miniature optical system packaging device used in this invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0036] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0037] Existing packaging technologies suffer from insufficient stability and poor airtightness in high-temperature environments, failing to meet the requirements for long-term use.

[0038] Please see Figures 2 to 4 As shown, to solve the challenges of packaging and miniaturizing optical systems under high-temperature conditions, this invention provides a high-temperature resistant miniaturized optical system packaging method, comprising the following steps:

[0039] S1, Laser drilling is performed on the ceramic plate to form a small-diameter through hole of 100um, and then the surface is cleaned.

[0040] The surface cleaning process includes the following steps: soaking the ceramic plate in acetone and anhydrous ethanol in sequence and then ultrasonically vibrating it to clean the surface. The surface is then dried with nitrogen gas to remove organic contaminants from the ceramic plate surface.

[0041] S2, a Ti / Cu metal layer is deposited on the surface of the ceramic plate obtained in step S1 using a sputtering deposition process as a seed layer;

[0042] S3 uses photolithography and development processes to form a mask pattern, then uses electroplating to fill through holes and thicken the surface copper layer, then uses surface grinding to level the electroplated copper layer, and finally uses surface treatment technology to form a Ni / Au layer.

[0043] S4, remove the dry film and etch the seed layer to obtain the high-temperature resistant ceramic packaging structure base 1; the dry film is the photoresist applied in the previous stage.

[0044] S5, the small optical system is glued to the high-temperature ceramic encapsulation structure base 1;

[0045] The small optical system, designated as small optical system 4, comprises a laser source 41, a support frame 42, optical lenses, a light-atomic interaction chamber 45, a heating and temperature control component 46, and a photoelectric signal acquisition device 47, all sequentially stacked and bonded together with adhesive. The optical lenses include an attenuator 43 and a quarter-wave plate 44. The adhesive used can be EPO-TEK 353ND.

[0046] S6, place the high-temperature resistant ceramic packaging shell 3, the high-temperature resistant ceramic packaging structure base with a small optical system obtained in step S5, and the indium-based sealing ring 2 into the vacuum chamber 51.

[0047] Please see Figure 4 As shown, the vacuum chamber 51 provides an anhydrous and oxygen-free environment. Inside the vacuum chamber 51 are a heating stage 55, a housing clamping seat 52 positioned above the heating stage 55, a three-dimensional moving platform 53 connected to the housing clamping seat 52, a vacuum pump 54, an air inlet 57, a gas cylinder 56 connected to the air inlet 57, and a sample inlet 58. The gas cylinder 56 contains a protective gas, such as high-purity nitrogen or high-purity argon, or other inert gases.

[0048] S7. In an anhydrous and oxygen-free environment, open the vacuum-packed indium-based sealing ring, place the indium-based sealing ring on the Ni / Au layer of the high-temperature ceramic packaging structure base, and then cover the high-temperature ceramic packaging shell on the high-temperature ceramic packaging structure base with the indium-based sealing ring; heat to the welding temperature to completely melt the indium-based sealing ring, and complete the welding between the high-temperature ceramic packaging shell, the indium-based sealing ring, and the high-temperature ceramic packaging structure base.

[0049] Specifically, step S7 includes the following process: using a vacuum pump 54 to extract the air from the vacuum chamber 51, and then filling the vacuum chamber 51 with a protective gas to create an anhydrous and oxygen-free environment to prevent oxidation of the indium-based sealing ring 2; opening the vacuum-packed indium-based sealing ring 2 in the protective gas atmosphere, and then covering the high-temperature ceramic package shell 3 onto the high-temperature ceramic package structure base 1 containing the indium-based sealing ring 2; subsequently, using the vacuum pump 54 to extract the protective gas from the vacuum chamber 51, controlling the vacuum degree to be less than 10 Pa; then heating to the welding temperature using the heating stage 55 inside the vacuum chamber 51, so that the indium-based sealing ring is completely melted, completing the welding between the high-temperature ceramic package shell, the indium-based sealing ring, and the high-temperature ceramic package structure base.

[0050] The welding temperature is 180-200℃. Indium-based sealing rings require low welding temperatures, resulting in less thermal damage to other components in small optical systems, less residual thermal stress, good hermeticity of the physical system, and the ability to operate for extended periods.

[0051] Please see Figures 1 to 2As shown, this invention provides a high-temperature resistant miniature optical system packaging structure, including a high-temperature resistant ceramic packaging structure base 1, a miniature optical system 4 bonded to the high-temperature resistant ceramic packaging structure base 1, a high-temperature resistant ceramic packaging shell 3 covering the high-temperature resistant ceramic packaging structure base 1, and an indium-based sealing ring 2 connecting the high-temperature resistant ceramic packaging structure base 1 and the high-temperature resistant ceramic packaging shell 3. The contact surface between the high-temperature resistant ceramic packaging structure base 1 and the indium-based sealing ring 2 is formed with a Ni / Au layer through surface treatment technology.

[0052] This invention selects high-temperature resistant ceramic as the encapsulation material. High-temperature resistant ceramic has high-temperature resistance and corrosion resistance. Using high-temperature resistant ceramic to prepare the encapsulation structure base and encapsulation shell can achieve high airtightness and high reliability of the physical system in high-temperature environments, meeting the requirements of long-term use. Furthermore, the high-temperature resistant ceramic encapsulation structure base 1 and the high-temperature resistant ceramic encapsulation shell 3 are made of the same material, and the overall thermal expansion is consistent, avoiding damage caused by inconsistent stress when working in high-temperature environments.

[0053] This invention uses an indium-based sealing ring 2 and welds a high-temperature resistant ceramic base 1 and a high-temperature resistant ceramic packaging shell 3 in an anhydrous and oxygen-free environment. The resulting packaging structure can maintain high stability and airtightness in a high-temperature environment.

[0054] The high-temperature resistant miniature optical system packaging method provided by the present invention will be described below with reference to specific embodiments.

[0055] Example 1

[0056] A method for packaging a high-temperature resistant miniature optical system mainly includes the following steps:

[0057] S1. Laser drilling is performed on the ceramic plate to form through holes with a diameter of 100um; then the ceramic plate is surface cleaned by immersing it in acetone and anhydrous ethanol and ultrasonic vibration in sequence, cleaning the surface of the ceramic plate, and then drying the surface with dry nitrogen to remove organic contaminants from the surface of the ceramic plate.

[0058] S2, a Ti / Cu metal layer is deposited on the surface of the ceramic plate obtained in step S1 using a sputtering deposition process as a seed layer;

[0059] S3, a mask pattern is formed using photolithography and development processes, and then through-hole filling and surface copper layer thickening are performed using electroplating processes; then, the electroplated copper layer is leveled by surface grinding, and a Ni / Au layer is formed by surface treatment technology;

[0060] S4, remove the dry film and etch the seed layer to complete the preparation of the high-temperature resistant ceramic packaging structure base 1;

[0061] S5. Following the installation sequence of laser light source 41, support frame 42, optical lens (attenuator 43, 1 / 4 wave plate 44), light and atom interaction gas chamber 45, heating temperature control component 46, and photoelectric signal acquisition device 47, a small optical system 4 is obtained by bonding with adhesive glue, and the small optical system 4 is then glued to the high temperature resistant ceramic encapsulation structure base 1.

[0062] S6, place the high-temperature resistant ceramic packaging shell 3, the high-temperature resistant ceramic packaging structure base (including a small optical system), and the indium-based sealing ring 2 into the vacuum chamber 51 through the sample inlet 58;

[0063] S7, the high-temperature ceramic packaging structure base (including a small optical system) is installed in the groove of the heating stage 55, and the high-temperature ceramic packaging shell 3 is installed on the shell clamping seat 52; the vacuum pump 54 extracts the air in the vacuum box 51, and the high-purity nitrogen protective gas in the gas cylinder 56 is filled into the vacuum box 51 to form an anhydrous and oxygen-free environment to prevent oxidation of the indium-based sealing ring; the indium-based sealing ring in the vacuum packaging is opened in the protective gas atmosphere and placed on the Ni / Au layer of the high-temperature ceramic packaging structure base. The high-temperature ceramic packaging shell 3 is moved to the high-temperature ceramic packaging structure base 1 with the indium-based sealing ring 2 placed on it by the three-dimensional moving platform 53.

[0064] Vacuum pump 54 extracts the protective gas from vacuum chamber 51, achieving a vacuum level of less than 10 Pa. Heating table 55 heats the gas to a welding temperature of 180-200℃. After the indium-based sealing ring completely melts, the welding between the high-temperature ceramic package shell, the indium-based sealing ring, and the high-temperature ceramic package structure base is completed.

[0065] Comparative Example 1

[0066] The main difference between Comparative Example 1 and Example 1 is that a vacuum chamber was not used in step S7, i.e., an indium-based sealing ring was not used in an anhydrous and oxygen-free environment. The rest is largely the same as Example 1 and will not be repeated here.

[0067] Experiments show that if an indium-based sealing ring is not used in a vacuum chamber environment, the ring is prone to oxidation in the atmosphere, resulting in poor sealing performance of the entire package and even causing the entire device to fail.

[0068] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A high-temperature-resistant small optical system packaging method, characterized in that, The method comprises the following steps: S1, laser drilling is performed on a ceramic plate to form through holes with a diameter of 100 um, and then surface cleaning treatment is performed; S2, a Ti / Cu metal layer is deposited on the surface of the ceramic plate obtained in step S1 as a seed layer by using a sputtering plating process; S3, a mask pattern is formed by using a photoetching and developing process, and then through hole filling and surface copper layer thickening are performed by using an electroplating process, and then the electroplated copper layer is flattened by surface grinding, and a Ni / Au layer is formed by surface treatment technology; S4, the dry film is removed and the seed layer is etched to obtain a high-temperature-resistant ceramic packaging structure base; S5, a small optical system is bonded to the high-temperature-resistant ceramic packaging structure base by using glue; S6, a high-temperature-resistant ceramic packaging shell, the high-temperature-resistant ceramic packaging structure base with the small optical system obtained in step S5, and an indium-based sealing ring are placed in a vacuum box; S7, in a water-free and oxygen-free environment, the vacuum-packaged indium-based sealing ring is opened, the indium-based sealing ring is placed on the Ni / Au layer of the high-temperature-resistant ceramic packaging structure base, and then the high-temperature-resistant ceramic packaging shell is placed on the high-temperature-resistant ceramic packaging structure base with the indium-based sealing ring; heating to a welding temperature to completely melt the indium-based sealing ring, and welding between the high-temperature-resistant ceramic packaging shell, the indium-based sealing ring and the high-temperature-resistant ceramic packaging structure base is completed. In step S7, the process comprises the following steps: air in the vacuum box is pumped out by using a vacuum pump, and then protective gas is filled into the vacuum box to form a water-free and oxygen-free environment to prevent the indium-based sealing ring from being oxidized; the vacuum-packaged indium-based sealing ring is opened in the protective gas atmosphere, and then the high-temperature-resistant ceramic packaging shell is placed on the high-temperature-resistant ceramic packaging structure base with the indium-based sealing ring; subsequently, the protective gas in the vacuum box is pumped out by using a vacuum pump, and the vacuum degree is controlled to be less than 10 Pa; then the heating table in the vacuum box is used to heat to a welding temperature to completely melt the indium-based sealing ring, and welding between the high-temperature-resistant ceramic packaging shell, the indium-based sealing ring and the high-temperature-resistant ceramic packaging structure base is completed.

2. The high-temperature-resistant small optical system package method according to claim 1, wherein In step S7, the welding temperature is 180-200 ℃.

3. The high-temperature-resistant small optical system package method according to claim 1, wherein The protective gas is high-purity nitrogen or high-purity argon.

4. The high-temperature-resistant small optical system package method according to claim 1, wherein The small optical system comprises a laser light source, optical lenses, a light-atom interaction gas chamber, a heating and temperature control assembly, a support frame and a photoelectric signal collector which are sequentially stacked and bonded.

5. The high-temperature-resistant small optical system package method according to claim 1, wherein In step S1, the surface cleaning treatment comprises the following steps: the surface of the ceramic plate is cleaned by sequentially immersing and ultrasonic oscillating in acetone and anhydrous ethanol, and the surface is dried by dry nitrogen to remove organic contamination on the surface of the ceramic plate. ​ 6. A high-temperature-resistant small optical system package structure, characterized in that, The packaging method of any one of claims 1-5 is adopted to obtain a packaging structure, which comprises a high-temperature-resistant ceramic packaging structure base, a small optical system adhered to the high-temperature-resistant ceramic packaging structure base, a high-temperature-resistant ceramic packaging shell arranged on the high-temperature-resistant ceramic packaging structure base, and an indium-based sealing ring connecting the high-temperature-resistant ceramic packaging structure base and the high-temperature-resistant ceramic packaging shell; and a contact surface between the high-temperature-resistant ceramic packaging structure base and the indium-based sealing ring is formed with a Ni / Au layer through a surface treatment technology.

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