Airtight packaging process of miniaturized laser gyroscope assembly

Abstract

The present application relates to the technical field of laser gyro, especially to a kind of air-tight packaging process of miniaturized laser gyro assembly.The air-tight packaging process of miniaturized laser gyro assembly of the present application includes the following steps: installing bidirectional electrical switching terminal on the side of each resonant cavity shell in miniaturized laser gyro assembly;using sealing glue and structural glue to seal the upper cover plate of each resonant cavity shell;after outer wrapping coating treatment, high-temperature baking treatment is carried out on each resonant cavity shell.It can solve the technical problem that air-tight packaging of miniaturized embedded laser gyro assembly is difficult, and realize low-cost air-tight packaging of miniaturized laser gyro assembly.

Description

Technical Field

[0001] This invention relates to the field of laser gyroscope technology, and more particularly to a hermetically sealed packaging process for a miniaturized laser gyroscope assembly. Background Technology

[0002] As a new generation of inertial sensors, laser gyroscopes are ideal components for inertial navigation, guidance, and control systems, and are finding increasingly widespread applications in aviation, aerospace, and other fields. To meet market demands for miniaturized and low-cost laser gyroscopes, a miniaturized embedded laser gyroscope assembly integrating three-axis laser gyroscopes has been developed. Compared to traditional IMU (Inertial Measurement Unit) assemblies, this assembly offers advantages such as small size, light weight, low cost, and low power consumption, meeting the requirements of new unmanned platforms, underwater / torpedo weapons, and land-based and airborne weapon platforms for small-volume, low-cost, and low-power inertial navigation equipment.

[0003] Miniaturized laser gyroscope components contain a three-axis laser gyroscope resonant cavity. To ensure reliable long-term operation, the component needs to be filled with nitrogen and hermetically sealed. To enhance market competitiveness, miniaturized laser gyroscope components are designed for extreme miniaturization and low cost. Traditional hermetically sealed electrical connectors cannot be used. Due to insufficient thickness for machining sealing rope mounting grooves, the cover cannot be hermetically sealed with sealing ropes. This renders traditional hermetically sealed processes for laser gyroscopes unsuitable for this type of product.

[0004] Therefore, in order to address the above issues, the industry urgently needs a hermetically sealed packaging process for miniaturized laser gyroscope components. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] The technical problem to be solved by the present invention is to provide a hermetically sealed assembly process for miniaturized laser gyroscope components, thereby solving the technical problem of the high difficulty in hermetically sealing miniaturized embedded laser gyroscope components.

[0007] (II) Technical Solution

[0008] To solve the above-mentioned technical problems, the present invention provides a hermetically sealed packaging process for a miniaturized laser gyroscope assembly, comprising the following steps:

[0009] A bidirectional electrical adapter terminal is installed on the side of each resonant cavity housing within the miniaturized laser gyroscope assembly;

[0010] The top cover of each of the resonant cavity housings is sealed with sealant and structural adhesive;

[0011] After the outer coating treatment, each of the resonant cavity shells is subjected to high-temperature baking treatment.

[0012] Furthermore, the installation of bidirectional electrical adapter terminals on the side of each resonant cavity housing within the miniaturized laser gyroscope assembly specifically involves:

[0013] Multiple mounting slots for mounting the corresponding bidirectional electrical adapter terminals are machined on the side of each resonant cavity mounting housing, and a set width of mounting position is reserved around each mounting slot.

[0014] Furthermore, a row of first terminals for welding all the wires of the laser gyroscope resonator cavity inside the assembly is reserved on the inner side of the bidirectional electrical adapter terminal, and another row of second terminals for welding the corresponding wires of the external circuit control board of the assembly is reserved on the outer side.

[0015] Furthermore, during soldering, the first terminal is first soldered using conventional solder wire, and then the second terminal is soldered using low-temperature solder wire.

[0016] Furthermore, the inner and outer sides of the bidirectional electrical adapter terminal are connected by a via, and the diameter of the via is smaller than a first preset value.

[0017] Furthermore, the sealing of the upper cover plate of each resonant cavity housing using sealant and structural adhesive specifically involves:

[0018] The interface of the upper cover plate of each of the resonant cavity housings is filled with the sealant, and then all the gaps of each upper cover plate are wrapped with the structural adhesive.

[0019] Furthermore, the structural adhesive must be de-bubbled before use.

[0020] Furthermore, the amount of gas released from the structural adhesive is lower than the second preset value.

[0021] (III) Beneficial Effects

[0022] The above-described technical solution of the present invention has the following advantages:

[0023] The hermetic assembly process of the miniaturized laser gyroscope assembly of the present invention utilizes bidirectional electrical adapter terminals and the processing technology of sealant and structural adhesive to achieve low-cost hermetic assembly of miniaturized laser gyroscope assemblies. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the hermetically sealed assembly process of the miniaturized laser gyroscope assembly of the present invention. Detailed Implementation

[0025] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] See Figure 1 This invention provides a hermetically sealed assembly process for a miniaturized laser gyroscope assembly, which may include the following steps:

[0029] S100. A bidirectional electrical adapter terminal is installed on the side of each resonant cavity housing within the miniaturized laser gyroscope assembly.

[0030] Specifically, the small laser gyroscope assembly contains a 3-axis laser gyroscope resonant cavity, which is installed in three embedded housings of the main body assembly. The dithering, frequency stabilization, and ignition wires assembled in the laser gyroscope resonant cavity need to pass through the housing and connect to the system's control circuit board to achieve the functions of power supply, control, and signal transmission.

[0031] In cases where traditional airtight electrical connectors cannot be used, corresponding bidirectional electrical adapter terminal mounting slots are machined on the side of each resonant cavity mounting housing for mounting bidirectional electrical adapter terminals. A 0.5mm wide mounting space is left around each side of the mounting slot for mounting electrical adapter terminals and applying sealant.

[0032] On the inner side of the bidirectional electrical adapter terminal, a row of first terminals is reserved for welding all the wires of the laser gyroscope resonator cavity inside the component. On the outer side, another row of second terminals, which are connected internally and externally, is reserved for welding the corresponding wires of the external circuit control board of the component. During welding, the first terminal is first welded with conventional solder wire, and then the second terminal is welded with low-temperature solder wire. The temperature of the soldering iron is strictly controlled to avoid the risk of the inner wires detaching when welding the outer wires. The inner and outer sides of the bidirectional electrical adapter terminal are connected by a via, and the diameter of the via is smaller than a first preset value. Considering the impact of temperature transfer during internal and external welding on the solder joint, a very small via design is adopted to reduce the welding temperature transfer.

[0033] S200. Seal the top cover plate of each of the resonant cavity housings using sealant and structural adhesive.

[0034] Specifically, because the thickness of the upper cover plate for mounting the resonant cavity housing is only 1mm, it is impossible to machine grooves for installing the sealing ropes, rendering traditional sealing methods unusable. To solve this problem, special structural adhesive and sealant are used to seal all gaps in the upper cover plate. Sealing silicone rubber is used to fill the interface of the upper cover, and then the special structural adhesive is used to wrap all gaps in the upper cover. This structural adhesive must be treated with a vacuum coating machine to remove air bubbles before application.

[0035] S300. After the outer coating treatment, each of the resonant cavity shells is subjected to high-temperature baking treatment.

[0036] The low-cost hermetic sealing process for miniaturized laser gyroscope components of the present invention is mainly aimed at miniaturized products that cannot use traditional electrical connectors and sealing ropes due to size, weight and cost limitations. It can effectively solve the problem of low-cost hermetic electrical connection for such products.

[0037] An airtightness testing platform was built to verify the airtightness of the product using the hermetically sealed packaging process employed in this invention.

[0038] A temporary testing platform was set up, utilizing a vacuum pump, valves, silicon tubes, and sealed tubing to construct a vacuuming and leak detection platform. During operation, the product to be tested was first fixed at the testing point. The valves and vacuum pump were then opened to evacuate the gas pressure inside the sealed tubing (including the product to be tested) to 10. -5 The pressure is measured in Pascals, then the valve is closed. The vacuum level changes throughout the sealed tube are monitored over a long period using a silicon tube to assess the sample's sealing performance. It should be noted that under normal circumstances, the shell is filled with approximately one atmosphere of nitrogen, resulting in a very small pressure difference between the inside and outside of the shell. -5 Detecting leaks under Pa conditions is an extremely stringent experimental procedure.

[0039] Leak testing was performed on three products packaged using the above process, and the results are shown in Table 1 below:

[0040] Table 1 Product Leak Detection Results

[0041] 1# 4.5Pa 5.3Pa 5.2Pa 2# 3.4Pa 5.7Pa 5.8Pa 3# 5.8Pa 6.1Pa 6.4Pa

[0042] It can be seen that in 10 -5 After being pressurized under vacuum conditions for 48 hours, the internal air pressure of the three products changed very little, proving the feasibility and reliability of this hermetically sealed packaging process.

[0043] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A hermetically sealed packaging process for a miniaturized laser gyroscope assembly, characterized in that, The process includes the following steps: A bidirectional electrical adapter terminal is installed on the side of each resonant cavity housing within the miniaturized laser gyroscope assembly; The top cover of each of the resonant cavity housings is sealed with sealant and structural adhesive; After the outer coating treatment, each of the resonant cavity shells is subjected to high-temperature baking treatment; Specifically, the installation of bidirectional electrical adapter terminals on the side of each resonant cavity housing within the miniaturized laser gyroscope assembly is as follows: Multiple mounting slots for mounting the corresponding bidirectional electrical adapter terminals are machined on the side of each resonant cavity mounting housing, and a set width of mounting position is reserved around each mounting slot. A row of first terminals is reserved on the inner side of the bidirectional electrical adapter terminal for welding all the wires of the laser gyroscope resonator cavity inside the assembly, and another row of second terminals, which are connected to the outside, is reserved on the outer side for welding the corresponding wires of the external circuit control board of the assembly.

2. The hermetically sealed packaging process for the miniaturized laser gyroscope assembly according to claim 1, characterized in that, During soldering, the first terminal is first soldered using conventional solder wire, and then the second terminal is soldered using low-temperature solder wire.

3. The hermetically sealed packaging process for the miniaturized laser gyroscope assembly according to claim 1, characterized in that, The inner and outer sides of the bidirectional electrical adapter terminal are connected by a via, and the diameter of the via is smaller than a first preset value.

4. The hermetically sealed packaging process for the miniaturized laser gyroscope assembly according to claim 1, characterized in that, The method of sealing the upper cover plate of each resonant cavity housing with sealant and structural adhesive is as follows: the interface of the upper cover plate of each resonant cavity housing is filled with sealant, and then all the gaps of each upper cover plate are wrapped with structural adhesive.

5. The hermetically sealed packaging process for the miniaturized laser gyroscope assembly according to claim 1, characterized in that, The structural adhesive must be de-bubbled before use.

6. The hermetically sealed packaging process for the miniaturized laser gyroscope assembly according to claim 5, characterized in that, The amount of gas released from the structural adhesive is lower than the second preset value.

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