A potting method for an aircraft engine data storage module

Abstract

The present invention discloses a method for encapsulating an aircraft engine data storage module. The present invention divides the internal cavity into two parts through a circuit board assembly, and provides a grounding surface on the housing of the circuit board assembly. Furthermore, the present invention is supplemented by an aluminum alloy cavity structure, an airtight electrical connector, and a sealing gasket with shielding performance, thereby achieving the purpose of good electromagnetic shielding performance and strong anti-electromagnetic interference capability. The present invention adopts a two-step method to encapsulate the interior of the data storage module, and controls the encapsulating compound to maintain a certain gap with the inner wall of the metal housing, thereby avoiding deformation of the encapsulating compound in low-pressure and large temperature difference environments, reducing the stress on the circuit board caused by deformation, improving the stability of the data storage module, and solving the problem that the internal data storage module is easily deformed and leads to performance degradation in low-pressure, large temperature difference, strong vibration impact, and complex electromagnetic environments.

Description

Technical Field

[0001] The present invention relates to the technical field of aviation data storage potting, and more particularly to a potting method for an aviation engine data storage module. Background Art

[0002] The aircraft engine data storage module is a data storage device used in aircraft engines to store information related to the auxiliary power unit. It interacts with the electronic controller through a control cable and is mainly composed of a shell, a cover, an electrical connector, a circuit board assembly, an electromagnetic interference filter, a sealing ring and a potting compound.

[0003] In the prior art, data storage modules are often potted as a whole to prevent the external environment from affecting internal electronic components and improve product reliability. For example, CN201920329170.2 discloses a potted micro-aviation storage module comprising a main control motherboard, a storage daughterboard, an intermediate structural member, a connector, and a structural member housing. The main control motherboard is located below the intermediate structural member and is bonded together with phase-change thermal grease. The storage daughterboard is located above the intermediate structural member and is bonded together with phase-change thermal grease. The main control motherboard, intermediate structural member, and storage daughterboard are integrally installed in the structural member housing and potted with a two-component epoxy resin adhesive. This patent uses an aluminum alloy structure, with the daughterboard and motherboard integrally potted, which increases the product's robustness and reliability, making it suitable for a variety of complex and harsh environments. The aluminum alloy and chip are bonded together to resist strong external impacts and electromagnetic radiation, facilitating heat dissipation. When the NAND flash reaches the maximum number of erase and write cycles, the storage module can be directly replaced, making the entire module easy to repair and replace. The installation environment of the storage module in the aircraft engine is even more severe. It needs to withstand low pressure, strong vibration and shock, and a complex electromagnetic environment. As shown in the above patent, it uses a one-time potting method, filling the entire interior of the shell with potting glue and sealing the bottom of the shell with a cover plate. In the low pressure, strong vibration and shock, and complex electromagnetic environment, the following problems will occur:

[0004] 1. Low air pressure at high altitudes causes the potting compound inside the product housing to deform, which in turn causes expansion and compression of the circuit boards. This uneven force distribution can easily cause deformation of the circuit boards, impacting their functionality. Furthermore, as flight altitudes change, the temperature difference between altitude and ground level increases. The potting compound inside the storage module can shrink significantly due to the drop in temperature, further stressing the circuit boards, causing deformation and damage. Consequently, aircraft engine data storage modules have a high failure rate and low reliability and durability.

[0005] 2. In the existing technology, integral potting is more commonly used. In the curing process, integral potting will generate certain stress. During the high and low temperature cycle test, the circuit board will be squeezed and deformed, affecting its function.

[0006] Therefore, it is necessary to improve the data storage module and the potting method to enhance the stability of the aircraft engine data storage module in low pressure, strong vibration and complex electromagnetic environments. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a potting method for an aircraft engine data storage module in view of the shortcomings of the existing aircraft engine data storage module, such as high failure rate, low reliability and durability.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A method for encapsulating an aircraft engine data storage module, the aircraft engine data storage module comprising a housing, a circuit board assembly, an electrical connector, and an electromagnetic interference filter; the housing being provided with an electrical connector mounting hole, an electromagnetic interference filter fixing member being provided within the housing, a grounding surface the size of the circuit board assembly being provided on the inner wall of the housing, a fixing through hole for the circuit board assembly being provided on the grounding surface, and a removable cover being provided on the back of the housing.

[0010] The aviation engine data storage module filling step includes:

[0011] S1. Install the electrical connector and EMI filter in the housing. Place the housing on a horizontal device with the cover facing upward. Inject potting compound into the lower space within the housing, ensuring a certain gap between the upper surface of the potting compound and the lower surface of the ground plane.

[0012] S2. Then, securely seal the circuit board assembly to the ground plane on the inner wall of the housing, dividing the interior of the housing into two independent, non-interconnected spaces. Before the potting compound cures, rotate the housing and place it on a horizontal device, with the potted portion facing upward. After the potting compound hardens, a certain gap exists between the upper surface of the potting compound and the inner wall of the housing.

[0013] S3. Then, place the housing on a horizontal device with the potted space facing downward. Pot along the circuit board assembly, ensuring that the potting glue height does not exceed the mounting surface of the cover and the housing, and that there is a certain gap between the cover and the housing. After the potting glue hardens, seal the cover.

[0014] Furthermore, the shell adopts an aluminum alloy structure. Aluminum alloy not only has good strength, but also is a conductive material and can shield the internal interference of external electromagnetic signals.

[0015] Furthermore, the electrical connector is an airtight electrical connector, and a sealing gasket with electromagnetic shielding performance is provided between the electrical connector and the housing to prevent electromagnetic leakage from gaps between the mounting holes, thereby further improving the electromagnetic shielding performance of the housing.

[0016] Furthermore, the certain gap between the potting compound and the inner wall of the shell is 1-3 mm, which can provide sufficient expansion space for the potting compound to deform under low pressure, thereby avoiding expansion and deformation of the shell.

[0017] Furthermore, the mounting hole and the mounting plane of the shell are in the same plane as the cover surface on the back side of the shell.

[0018] Furthermore, a sealing member is provided between the cover plate and the housing.

[0019] Furthermore, the potting compound is subjected to vacuum degassing to prevent bubbles in the potting compound from expanding under low pressure after solidification, thereby increasing the expansion rate of the potting compound and reducing the volume change rate of the potting compound.

[0020] Furthermore, the potting compound utilizes room temperature vulcanized silicone rubber. Vulcanized silicone rubber does not require heating or pressurization at room temperature and has a relatively fast vulcanization time, effectively preventing damage to components caused by high vulcanization temperatures. It also provides protection against moisture, corrosion, and shock. After vulcanization, room temperature vulcanized silicone rubber exhibits excellent anti-stick properties and minimal shrinkage during vulcanization, preventing the potting compound from squeezing or damaging components during curing and shrinkage.

[0021] Furthermore, the raw materials of the room temperature vulcanized silicone rubber include two-component room temperature vulcanized methyl silicone rubber, ethyl orthosilicate and dibutyltin dilaurate, and the mass ratio thereof is 100:4-6:2-3.

[0022] Furthermore, the hardening temperature is no higher than 60° C., and the hardening time is 12-24 hours.

[0023] Compared with the prior art, the beneficial effects are:

[0024] The present invention divides the internal cavity into two parts through a circuit board assembly, and provides a grounding surface on the shell of the circuit board assembly, supplemented by an aluminum alloy cavity structure, an airtight electrical connector and a sealing gasket with shielding performance, so as to achieve the purpose of good electromagnetic shielding performance and strong anti-electromagnetic interference ability.

[0025] The present invention adopts a two-step method to potting the inside of the data storage module, and controls the potting glue to maintain a certain gap with the inner wall of the metal shell, thereby avoiding the deformation of the shell by the potting glue under low pressure and temperature change environment, reducing the stress on the circuit board caused by the deformation of the shell, and improving the stability of the data storage module. In addition, the present invention leaves a certain gap in both independent spaces to ensure that the potting glue in each space is evenly deformed to the gap on both sides, avoiding the potting glue in one space from squeezing and deforming the circuit board assembly. The present invention adopts a method of improving the hardening degree of glue by using room temperature silicone rubber and a suitable ratio of potting glue raw materials, which can meet the requirements of low pressure and large temperature change environments, and avoid the problem of easy deformation inside the data storage module and resulting in performance degradation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of the aviation engine data storage module in the embodiment;

[0027] Figure 2 Schematic diagram of the structure of the aviation engine data storage module in the embodiment;

[0028] Figure 3 A schematic diagram of the circuit board assembly and the housing ground plane in the embodiment;

[0029] Figure 4 Schematic diagram of encapsulation of an aircraft engine data storage module in an embodiment;

[0030] Among them, 1 is a shell, 2 is a circuit board assembly, 3 is an electromagnetic interference filter, 4 is a cover, 5 is an electrical connector, 6 is a sealing gasket, 7 is a sealing ring, 8 is a grounding surface, 9 is a potting compound, and 10 is a gap. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] It should be noted that if there are directional indications (such as up, down, left, right, front, and back) in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly. If there are descriptions of "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features.

[0033] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "provided with," "connected," etc., should be understood in a broad sense. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical connection or an electrical connection; it may refer to a direct connection or an indirect connection through an intermediate medium; it may refer to internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0034] Example 1

[0035] like Figure 1-3 This embodiment provides an aircraft engine data storage module comprising an aluminum alloy housing 1, a circuit board assembly 2, an electrical connector 5, and an electromagnetic interference filter 3. The electrical connector 5 is mounted on the aluminum alloy housing 1 and provided with a mounting hole for the electrical connector 5. The electromagnetic interference filter 3 is fixed to an electromagnetic interference filter 3 fixture on the inner wall of the aluminum alloy housing 1. A closed ground plane 8 is provided on the inner wall of the aluminum alloy housing 1, and a through-hole for fixing the circuit board assembly 2 is provided on the ground plane 8. The circuit board assembly 2 cooperates with the ground plane 8 on the inner wall of the aluminum alloy housing 1 to divide the interior space of the aluminum alloy housing 1 into two independent, non-interconnected spaces. A removable cover plate 4 is provided on the back of the aluminum alloy housing 1. The cover plate 4, the mounting holes of the housing 1, and the mounting plane are aligned.

[0036] Example 2

[0037] like Figure 4 This embodiment provides a potting method for the aviation engine data storage module according to the embodiment 1, and the specific steps include:

[0038] S1. Install the electromagnetic interference filter 3 and electrical connector 5 on the aluminum alloy housing 1. Place the aluminum alloy housing 1 on a horizontal device with the cover plate 4 facing upward. Inject potting compound into the lower space within the aluminum alloy housing 1, ensuring a certain gap between the upper surface of the potting compound 9 and the grounding surface of the circuit board assembly 2.

[0039] S2. Then, securely attach the circuit board assembly 2 to the ground plane 8 on the inner wall of the aluminum alloy housing 1, dividing the interior of the aluminum alloy housing 1 into two independent, non-interconnected spaces. Before the potting compound 9 cures, rotate the aluminum alloy housing 1 and place it on a horizontal device, with the potted portion facing upward. After the potting compound hardens, a gap should remain between the upper surface of the potting compound 9 and the inner wall of the aluminum alloy housing 1.

[0040] S3. Reverse the orientation of the aluminum alloy housing 1 and place it on a horizontal device, so that the potted space with the electromagnetic interference filter 3 and one end of the electrical connector 5 is at the bottom, and the unpotted space with the cover plate 4 is at the top. Input potting glue 9 along the circuit board assembly 2, and control the height of the potting glue 9 not to exceed the installation surface of the cover plate 4 and the housing 1. There is a certain gap between the potting glue 9 and the cover plate 4. After the potting glue 9 hardens, seal the cover plate 4.

[0041] This embodiment adopts a two-step method to potting the interior of the data storage module, and controls the potting compound 9 to maintain a certain gap with the inner wall of the aluminum alloy shell 1, thereby preventing the potting compound 9 from expanding the shell 1 under low pressure, reducing the deformation of the circuit board caused by the deformation of the shell 1, and improving the stability of the data storage module.

[0042] Example 3

[0043] like Figure 1-3 This embodiment provides an aircraft engine data storage module comprising an aluminum alloy housing 1, a circuit board assembly 2, an electrical connector 5, and an electromagnetic interference filter 3. The aluminum alloy housing 1 not only has good strength, but aluminum alloy is also a conductive material, which can shield internal interference from external electromagnetic signals. The electrical connector 5 is mounted on the aluminum alloy housing 1 and has a mounting hole for the electrical connector 5. The electrical connector 5 is hermetically sealed, with a shielding gasket 6 provided between the electrical connector 5 and the mounting hole of the aluminum alloy housing 1. This prevents external electromagnetic interference from leaking through the gap between the electrical connector 5 and the components within the aluminum alloy housing 1, thereby improving electromagnetic shielding capabilities. The electromagnetic interference filter 3 is fixed to an electromagnetic interference filter 3 fixture on the inner wall of the aluminum alloy housing 1. A closed grounding surface 8 is provided on the inner wall of the aluminum alloy housing 1, with through holes for fixing the circuit board assembly 2. The circuit board assembly 2 cooperates with the grounding surface 8 on the inner wall of the aluminum alloy housing 1 to divide the interior of the aluminum alloy housing 1 into two independent, non-interconnected spaces. A detachable cover plate 4 is provided on the back of the aluminum alloy housing 1 , and a sealing ring 7 is provided between the cover plates 4 . The surface of the cover plate 4 , the mounting hole of the housing 1 and the mounting plane are in the same plane.

[0044] The present invention divides the internal cavity into two parts through the circuit board assembly 2, and provides a grounding surface 8 on the shell 1 of the circuit board assembly 2, and is supplemented by an aluminum alloy cavity structure, an airtight electrical connector 5 and a sealing gasket 6 with shielding performance, so as to achieve the purpose of good electromagnetic shielding performance and strong anti-electromagnetic interference ability.

[0045] Example 4

[0046] like Figure 4 This embodiment provides a potting method for the aviation engine data storage module according to the third embodiment, and the specific steps include:

[0047] S1. Install the electromagnetic interference filter 3 and the electrical connector 5 on the aluminum alloy shell 1, place the aluminum alloy shell 1 on a horizontal device with one end of the cover plate 4 facing upward, and connect a through hole of the circuit board assembly 2 on the ground surface to the lower space inside the aluminum alloy shell 1.

[0048] S2. After fully mixing two-component room temperature vulcanized methyl silicone rubber RTV107, ethyl orthosilicate, and dibutyltin dilaurate in a mass ratio of 100:4-6:2-3, place the mixture in a vacuum pump and start the pump to remove bubbles in the potting compound 9.

[0049] S3. To the lower space within the aluminum alloy shell 1 ( Figure 4In the area A shown in FIG, , that is, the space where the electromagnetic interference filter 3 is provided, a potting compound 9 is injected, and a gap 10 of 1-3 mm is maintained between the upper surface of the potting compound 9 and the grounding surface of the fixed circuit board assembly 2. The through hole into which the potting compound 9 is injected is then sealed. The direction of the aluminum alloy housing 1 is reversed and placed on a horizontal device with the potting portion facing upward. The vulcanization temperature is controlled below 60° C. and the housing is left to harden and solidify. After solidification, a certain gap exists between the upper surface of the potting compound 9 and the inner wall of the aluminum alloy housing 1.

[0050] S4. Then, the aluminum alloy housing 1 is placed on a horizontal device in a reverse direction, that is, the space at one end of the potted portion, which is provided with the electromagnetic interference filter 3 and the electrical connector 5 ( Figure 4 The A area shown in FIG is below, including the cover plate 4, the unsealed space ( Figure 4 As shown in area B in the figure, room temperature vulcanized silicone rubber is input along the circuit board assembly 2, and the height of the potting glue 9 is controlled not to exceed the installation surface of the cover plate 4 and the housing 1, and a gap 10 of 1-3 mm is maintained between the potting glue 9 and the cover plate 4. The vulcanization temperature is controlled below 60°C and it is left to stand for 24 hours to harden and solidify.

[0051] S5. The potting glue 9 should be completely vulcanized. Check that there are no cavities or large bubbles in the potting glue 9, and that there is no potting glue 9 in the non-potting area. Cover with the sealing ring 7 and the cover plate 4 to complete the filling of the aircraft engine data storage module.

[0052] This embodiment adopts a two-step method to potting the interior of the data storage module, and controls the potting compound 9 to maintain a certain gap with the inner wall of the aluminum alloy shell 1, thereby preventing the potting compound 9 from expanding the shell 1 under a low-pressure environment, reducing the deformation of the circuit board caused by the deformation of the shell 1. At the same time, the storage module of the present invention improves the stability of the data storage module.

[0053] Furthermore, this embodiment uses room temperature silicone rubber and a suitable ratio of potting glue 9 raw materials to improve the hardening degree of the glue, which can meet the requirements of low pressure and large temperature changes, and avoid the problem of deformation inside the data storage module causing performance degradation.

[0054] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A potting method for an aircraft engine data storage module, characterized in that: The aircraft engine data storage module includes a housing, a circuit board assembly, an electrical connector, and an electromagnetic interference filter. The housing is provided with an electrical connector mounting hole, an electromagnetic interference filter fixing member is provided inside the housing, a grounding surface the size of the circuit board assembly is provided on the inner wall of the housing, a fixing through hole for the circuit board assembly is provided on the grounding surface, and a removable cover is provided on the back of the housing; The aviation engine data storage module filling step includes: S1. Install the electrical connector and EMI filter in the housing. Place the housing on a horizontal device with the cover facing upward. Inject potting compound into the lower space within the housing, ensuring a certain gap between the upper surface of the potting compound and the lower surface of the ground plane. S2. The circuit board assembly is then secured to the ground plane on the inner wall of the housing, dividing the interior of the housing into two independent, non-interconnected spaces. Before the potting compound cures, the housing is rotated and placed on a horizontal device, with the potted portion facing upward. After the potting compound hardens, a gap exists between the upper surface of the potting compound and the inner wall of the housing. S3. Then, place the housing on a horizontal device with the potted space facing downward. Pot along the circuit board assembly, ensuring that the potting glue height does not exceed the mounting surface of the cover and the housing, and that there is a certain gap between the cover and the housing. After the potting glue hardens, seal the cover.

2. The method for encapsulating an aircraft engine data storage module according to claim 1, characterized in that: The shell adopts an aluminum alloy structure.

3. The method for encapsulating an aircraft engine data storage module according to claim 1, characterized in that: The electrical connector is a sealed electrical connector, and a sealing gasket with shielding performance is provided between the electrical connector and the shell.

4. The method for encapsulating an aircraft engine data storage module according to claim 1, characterized in that: The certain gap is 1-3 mm.

5. The method for encapsulating an aircraft engine data storage module according to claim 1, characterized in that: The mounting hole and the mounting plane of the shell are in the same plane as the cover surface on the back side of the shell.

6. The method for encapsulating an aircraft engine data storage module according to claim 1, characterized in that: A sealing member is provided between the cover plate and the shell.

7. The method for encapsulating an aircraft engine data storage module according to claim 1, characterized in that: The potting glue is vacuum-debubbled.

8. The method for encapsulating an aircraft engine data storage module according to claim 1, characterized in that: The potting compound is room temperature vulcanized silicone rubber.

9. The method for encapsulating an aircraft engine data storage module according to claim 8, characterized in that: The raw materials of the room temperature vulcanized silicone rubber include two-component room temperature vulcanized methyl silicone rubber RTV107, ethyl orthosilicate and dibutyltin dilaurate, and the mass ratio thereof is 100:4-6:2-3.

10. The method for encapsulating an aircraft engine data storage module according to claim 9, characterized in that: The hardening temperature is no higher than 60° C. and the hardening time is 12-24 hours.

Images