High sensitivity sensor packaging structure with rigid-flex decoupling and multi-physical field interference resistance

Abstract

The application discloses a rigid-flexible decoupling type high-sensitivity sensor packaging structure resisting multi-physical field interference. The core bearing assembly is composed of a supporting base and a conductive functional layer; an interface damping layer is arranged on the inner wall of the shell frame; upper and lower buffer lines are respectively arranged on the bottom surface of the suspension guide groove and the inner surface of the cover plate and are attached to the upper and lower surfaces of the core bearing assembly; positioning ribs are arranged on the inner side of the shell frame and are in interference fit with the positioning grooves on the core bearing assembly, and the height of the positioning ribs is greater than the height of the buffer lines, so that the path decoupling of static positioning and dynamic energy consumption is realized. The edge of the cover plate is provided with a main sealing fit, the end of the positioning rib is provided with an interlocking buckle, and the inner wall of the shell is provided with an embedded structure, forming a three-in-one protection. The application has compact structure and feasible process, can significantly reduce the wideband vibration transmission rate while ensuring submicron positioning accuracy, and is suitable for precision measurement scenes with strict requirements on accuracy and reliability. The design realizes effective attenuation of wideband mechanical vibration while ensuring static submicron positioning accuracy, and simultaneously considers efficient heat dissipation, electromagnetic shielding and long-term air-tight reliability.

Description

Technical Field

[0001] This invention relates to the field of precision electronic packaging technology, specifically to an integrated packaging structure that provides a stable working environment for high-sensitivity sensors, suitable for precision measurement scenarios sensitive to mechanical vibration, temperature fluctuations, and electromagnetic interference. Background Technology

[0002] In precision measurement and photoelectric detection systems, the detection accuracy of the core sensing element is highly dependent on its packaging structure's ability to isolate external environmental stresses. The intrusion of multiple physical fields, such as mechanical vibration, temperature cycling, and electromagnetic noise, can easily lead to signal drift, decreased signal-to-noise ratio, and long-term reliability degradation. Existing packaging technologies often simply combine rigid positioning and flexible damping, resulting in a common problem of incompatibility between positioning accuracy and vibration isolation. While fully rigid packaging can provide sub-micron level positioning accuracy, it transmits external mechanical energy to the sensing element with almost no attenuation under broadband vibration, leading to increased dynamic noise. Although fully flexible suspended packaging can isolate high-frequency vibrations, it lacks a definite positioning reference in static conditions, making it prone to uncontrollable displacement under gravity or low-frequency inertial forces, similarly affecting measurement accuracy. Therefore, there is an urgent need for an integrated packaging solution that combines rigid positioning, flexible damping, efficient heat dissipation, and electromagnetic compatibility. Summary of the Invention

[0003] (a) Technical problems to be solved This invention aims to solve the conflict between rigid constraints and flexible damping functions in existing packaging technologies, and provides a high-sensitivity sensor packaging structure with rigid-flexible decoupling to resist multi-physical field interference. Through structural co-design, it achieves effective attenuation of broadband mechanical vibrations while ensuring static sub-micron positioning accuracy, and also takes into account efficient heat dissipation, electromagnetic shielding, and long-term hermetic reliability.

[0004] (II) Technical Solution A rigid-flexible decoupled high-sensitivity sensor packaging structure resistant to multi-physics interference includes: • Core support component: It consists of a core support substrate (101) and a conductive functional layer (102) wrapped around it; • Interface damping layer (103): formed on the inner wall of the outer shell frame (104) to support the microstructure; • Outer frame (104): It has an assembly window at the bottom and a suspension guide groove (107) on the inner wall. • Cover plate (110): Used to close the assembly window; The specific composition of the rigid-flexible synergistic structure is as follows: The bottom surface of the suspension guide groove (107) is provided with an upper buffer texture (111), and the inner surface of the cover plate (110) is provided with a lower buffer texture (111c). The two are respectively attached to the upper and lower surfaces of the core bearing component. The upper and lower buffer textures are formed on the surface of the interface damping layer, and their geometric shape is a periodic array of protrusions or concentric ring waves.

[0005] The inner side of the outer frame (104) is provided with a positioning rib (107b), and the core bearing component is provided with a positioning groove (102a) that engages with the positioning rib (107b). The two achieve deterministic mechanical positioning without gaps through an interference fit. The height of the positioning rib (107b) is greater than the height of the upper buffer groove (111) and the lower buffer groove (111c), and the height difference is 0.03 to 0.10 mm.

[0006] Unlike the conventional approach of simply superimposing rigid constraints and flexible damping in traditional packaging, where functions mutually restrict each other, this invention spatially separates the positioning ribs and buffer patterns. By setting the height of the positioning ribs to be greater than the height of the buffer patterns, the core load-bearing component in a static assembly state is preferentially contacted and interference-locked by the positioning ribs, achieving sub-micron-level deterministic positioning. When dynamic vibration or temperature deformation causes inertial forces or thermal stresses to exceed the static friction limit of the rigid contact surface, the buffer patterns intervene, dissipating energy through viscoelastic hysteresis and interface micro-slippage. Thus, the static positioning chain and the dynamic energy dissipation chain are decoupled in physical path, resolving the common contradiction between high-precision positioning and broadband vibration isolation.

[0007] In terms of functional adaptation structure, the outer shell frame (104) or the cover plate (110) is provided with a light-transmitting window (103b) for providing an input or output window for optical signals to the sensor chip inside the package. Both the outer shell frame (104) and the cover plate (110) are made of high thermal conductivity insulating material to form an efficient heat conduction path.

[0008] Furthermore, the edge of the cover plate (110) is provided with a main sealing fit (M), which is pressed against the interface damping layer (103) to form a full-circle airtight seal. The end of the positioning rib (107b) is provided with an interlocking buckle (N), which interlocks with the bottom of the positioning groove (102a) to prevent loosening. The inner wall of the outer shell frame (104) is provided with a fitting structure (Q), in which the outer edge of the cover plate (110) is embedded to achieve radial locking.

[0009] Furthermore, the suspension guide groove (107) is provided with lateral guide ribs (111b) on its front and rear side walls, and the inner surface of the cover plate (110) is provided with lateral guide ribs (111d). The two are symmetrical and are used for assembly guidance. The height of the lateral guide ribs (111b, 111d) is the same as the height of the positioning rib (107b).

[0010] Furthermore, the non-cooperating region of the interface damping layer (103) is provided with a microcavity region (W), which is a periodically arranged array of microcavities used to dissipate vibration energy.

[0011] Furthermore, an upper buffer gap (Cavity-1) is left between the upper buffer pattern (111) and the upper surface of the core support component, a lower buffer gap (Cavity-2) is left between the lower buffer pattern (111c) and the lower surface of the core support component, and a lead wire hole (Cavity-3) is provided at the bottom of the cover plate (110).

[0012] Furthermore, when the total thickness of the core load-bearing component is relatively thin, an annular groove (107a) can be used instead of the positioning rib (107b). The annular groove is formed on the inner wall of the outer shell frame (104), and the side wall of the core load-bearing component is provided with a corresponding protruding rib. The two are interference-fitted to achieve three-way positioning.

[0013] Optionally, to enhance electromagnetic shielding effectiveness, a conductive closed ring can be installed around the cover plate to form a Faraday cage structure with the conductive functional layer. For signal extraction or venting, oblique through holes can be opened on the side wall of the outer frame, with an insulating layer inside the holes and a sealing fixing body filled within.

[0014] (III) Beneficial Effects Compared with the prior art, the present invention has the following beneficial effects: 1. Clear rigid-flexible decoupling mechanism. By spatially separating the positioning ribs and the buffer strips, and setting the former to be taller than the latter, a nonlinear mechanical interface of "static rigidity prioritizing positioning and dynamic flexibility lag-initiating" is achieved. In the static state, the interference-fit positioning ribs provide sub-micron-level zero displacement constraint; in the dynamic state, when external excitation exceeds a threshold, the buffer strip intervenes to dissipate energy. The functional interface between the two is clear, and the load transmission path is separated, fundamentally solving the core contradiction of mutual constraint between high-precision positioning and wide-frequency vibration isolation in traditional packaging.

[0015] 2. Balancing positioning and vibration isolation. Based on finite element simulation analysis, the static offset is at the sub-micron level, and the broadband vibration transmissibility is significantly reduced compared to traditional rigid packaging.

[0016] 3. High thermal reliability. Utilizing a material system with matched coefficients of thermal expansion, it exhibits low interfacial thermal stress under temperature cycling, resulting in good long-term stability.

[0017] 4. Simple process and low cost. Microstructures can be achieved through conventional processes such as imprinting, etching, and dispensing, without the need for complex microfabrication, ensuring a secure and controllable supply chain.

[0018] 5. Structural strength and sealing performance have been theoretically verified. Based on Hertzian contact theory, a mechanical analysis of the interference fit between the positioning ribs and the positioning grooves was performed. The theoretical value of the contact stress obtained is far lower than the bending strength of the ceramic material used, and the structure has no risk of crushing or cracking. Based on the sealing compression ratio analysis, the compression of the interface damping layer in the assembled state was theoretically calculated and is within the ideal working range for the elastomeric material to achieve reliable sealing. Based on tolerance accumulation analysis, the height difference remains effective even under the worst-case machining tolerance combination, and the rigid-flexible decoupling mechanism will not fail. Attached Figure Description

[0019] Figure 1 This is a three-dimensional exploded view of the cubic configuration packaging structure of the present invention.

[0020] Figure 2 This is a schematic diagram of the core load-bearing components and cover plate structure.

[0021] Figure 3 This is a structural diagram of the core load-bearing components (101+102) and their upper and lower buffer gaps (Cavity-1, Cavity-2). Detailed Implementation

[0022] Example 1 (Standard Configuration) The core support component consists of a core support substrate (101) and a conductive functional layer (102) wrapped around it. The core support substrate is made of a high-insulation, high-rigidity structural ceramic material, preferably alumina ceramic or aluminum nitride ceramic. The conductive functional layer is formed on the surface of the core support substrate by physical vapor deposition or electroplating, and its material is selected from metals or alloys with a coefficient of thermal expansion matching that of the core support substrate.

[0023] Both the outer frame (104) and the cover plate (110) are made of a highly thermally conductive insulating material, preferably aluminum nitride ceramic. The inner wall of the outer frame is coated with an elastomeric material to form an interface damping layer (103), preferably fluorosilicone rubber, which has stable damping characteristics and a low gas release rate in a wide temperature range of -55°C to 125°C.

[0024] A positioning rib (107b) is provided on the bottom surface of the suspension guide groove (107), and a corresponding positioning groove (102a) is provided on the core load-bearing component. An interference fit is used between the two to achieve deterministic positioning of the core load-bearing component in three translational directions. An upper buffer texture (111) is formed on the surface of the interface damping layer on the bottom surface of the suspension guide groove, and a lower buffer texture (111c) is formed on the surface of the interface damping layer on the inner surface of the cover plate. The height of the positioning rib is greater than the height of the buffer texture.

[0025] The light-transmitting window (103b) is located on the inside of the cover plate, corresponding to the optically sensitive area of ​​the sensor chip. All inner and outer edges and corners of the housing frame, core load-bearing components, and cover plate are designed with rounded corners to reduce stress concentration and facilitate cleaning.

[0026] The cover plate (110) has a main sealing fit (M) at its edge, which is pressed tightly against the interface damping layer to form a full-circle airtight seal. The end of the positioning rib (107b) is provided with an interlocking buckle (N), which interlocks with the bottom of the positioning groove (102a) to prevent loosening. The inner wall of the outer shell frame (104) is provided with a fitting structure (Q), in which the outer edge of the cover plate is embedded to achieve radial locking.

[0027] Lateral guide ribs (111b) are provided on the front and rear side walls of the suspension guide groove (107), and lateral guide ribs (111d) are provided on the inner surface side edge of the cover plate. The two are symmetrical and are used for assembly guidance. The non-coupling area of ​​the interface damping layer is provided with a microcavity region (W), which is a periodically arranged microcavity array.

[0028] An upper buffer gap (Cavity-1) is left between the upper buffer pattern (111) and the upper surface of the core support component, and a lower buffer gap (Cavity-2) is left between the lower buffer pattern (111c) and the lower surface of the core support component. A lead hole (Cavity-3) is provided at the bottom of the cover plate for vertical lead-out of signal lines.

[0029] As a further optimization, the outer frame can adopt a five-sided one-piece molding structure to reduce the number of splicing seams. Angled through holes can be opened in the side walls of the outer frame to balance air pressure.

[0030] Example 2 (Thinner Configuration) When the total thickness of the core load-bearing component is relatively thin, an annular groove (107a) is used instead of the raised positioning rib (107b). The annular groove is formed on the inner wall of the outer shell frame, and the side wall of the core load-bearing component is provided with a corresponding raised rib. The two are interference-fitted to achieve three-way positioning. The remaining structure and materials are the same as in Embodiment 1.

Claims

1. A rigid-flexible decoupled high-sensitivity sensor packaging structure resistant to multi-physics interference, characterized in that, include: The core support component consists of a core support substrate (101) and a conductive functional layer (102) wrapped around it; An interface damping layer (103) is formed on the inner wall surface of the outer shell frame (104). The interface damping layer (103) has a light-transmitting part (103b), the light-transmitting part (103b) has the same thickness as the interface damping layer (103), and has the function of transmitting light of a specific wavelength. The outer frame (104) has an assembly window at its bottom and a suspension guide groove (107) formed on its inner wall by the interface damping layer (103). Cover plate (110) for closing the assembly window; in, The bottom surface of the suspension guide groove (107) is provided with an upper buffer texture (111), and the inner surface of the cover plate (110) is provided with a lower buffer texture (111c). The two are respectively attached to the upper and lower surfaces of the core bearing component. The surface of the interface damping layer (103) is formed with positioning ribs (107b), and the surface of the conductive functional layer (102) is provided with positioning grooves (102a). The positioning grooves engage with the positioning ribs (107b) to form an interference fit. The height of the positioning rib (107b) is greater than the height of the upper buffer strip (111) and the lower buffer strip (111c).

2. The packaging structure according to claim 1, characterized in that, The outer frame (104) and the cover plate (110) are both made of high thermal conductivity insulating material; the interface damping layer (103) is made of elastomeric material; the upper buffer texture and the lower buffer texture are formed on the surface of the interface damping layer.

3. The packaging structure according to claim 1, characterized in that, The height of the positioning rib (107b) is 0.03 to 0.10 mm higher than the height of the upper buffer strip (111) and the lower buffer strip (111c); the interference of the interference fit is 0.01 to 0.05 mm.

4. The packaging structure according to claim 1, characterized in that, All inner and outer edges and corners of the outer shell frame (104), core load-bearing components and cover plate (110) are designed with rounded corners; the outer shell frame (104) is cubic or cylindrical in shape.

5. The packaging structure according to claim 1, characterized in that, The interface damping layer (103) has an annular groove (107a) at the slot, and the side wall of the core bearing component is provided with a corresponding protruding rib. The annular groove and the protruding rib are interference fit. The annular groove (107a) has a flat shape design, fully retains the limiting and buffering functions, and is used to replace the positioning rib (107b), which is suitable for thin core bearing components.

6. The packaging structure according to claim 1, characterized in that, The bottom of the cover plate (110) is provided with a lead hole (Cavity-3), which penetrates the cover plate and the corresponding lower buffer pattern (111c) for vertical signal line lead-out.

7. The packaging structure according to claim 1, characterized in that, The cover plate (110) has a main sealing fit (M) at its edge, which is pressed together with the interface damping layer (103) to form a full circle of airtightness; the cover plate (110) has a U-shaped groove (N), the end of the positioning rib (107b) is fitted into the U-shaped groove (N), and a preset assembly gap is provided between the outer wall of the positioning rib (107b) and the inner wall of the U-shaped groove (N), so that the overall positioning and anti-loosening is achieved through the concave-convex fit between the two; the inner wall of the outer shell frame (104) has a fitting groove (Q), and the outer edge of the cover plate (110) is embedded in the fitting groove to achieve radial locking.

8. The packaging structure according to claim 1, characterized in that, The non-cooperating region of the interface damping layer (103) is provided with a microcavity region (W), which is a periodically arranged microcavity array.

9. The packaging structure according to claim 1, characterized in that, An upper buffer gap (Cavity-1) is left between the upper buffer pattern (111) and the upper surface of the core bearing component, and a lower buffer gap (Cavity-2) is left between the lower buffer pattern (111c) and the lower surface of the core bearing component.

10. The packaging structure according to claim 1, characterized in that, The suspension guide groove (107) has lateral guide ribs (111b) on its front and rear side walls, and the cover plate (110) has lateral guide ribs (111d) on its inner surface side edge. The two are symmetrical and are used for assembly guidance. The height of the lateral guide ribs (111b, 111d) is the same as the height of the positioning rib (107b).

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