Ultra-low noise rigid-flex printed circuit board for cryogenic control module

Abstract

The utility model relates to a circuit board technical field, especially a kind of ultra-low-noise rigid-flexible combination circuit board for low-temperature control module, including two symmetrically arranged hard circuit boards, two the hard circuit boards between fixedly connected with two upper and lower corresponding soft circuit boards.The utility model has the advantages that the limiting protrusion of the heat-conducting pad bottom surface is embedded in the limiting recess of flexible frame and fixed by heat-conducting glue, ensuring that the heat-conducting pad is tightly attached to the flexible frame and reducing thermal resistance.The flexible partition effectively maintains the heat dissipation space between the soft circuit boards, cooperates with the efficient heat-conducting performance of the heat-conducting pad, forms a smooth heat dissipation path from the soft circuit board to the flexible frame, solves the problem of poor heat dissipation of traditional multi-layer stacked soft circuit boards, and the cooperation of the limiting protrusion and the limiting recess ensures the stable installation of the heat-conducting pad, avoids poor contact caused by vibration and other factors to affect heat dissipation, allows heat to be dissipated in time, guarantees the stability of the conductive layer of the soft circuit board, and further maintains the ultra-low-noise performance of the circuit board.

Description

Technical Field

[0001] This utility model relates to the field of circuit board technology, and in particular to an ultra-low noise rigid-flex circuit board for a low-temperature control module. Background Technology

[0002] Embedded rigid-flex circuit boards are composite electronic components that integrate rigid and flexible circuit boards through a single design. They are widely used in electronic devices with stringent requirements for space layout, signal transmission, and environmental adaptability. Through processes such as lamination and soldering, the boards are embedded into predetermined areas of a rigid substrate, forming a circuit board that combines rigid support with flexible bending capabilities. The rigid portion provides a stable mounting base, supporting components such as chips and capacitors while ensuring structural strength; the flexible portion possesses bendable and foldable characteristics, adapting to complex internal spatial arrangements and enabling circuit connections between different rigid modules.

[0003] In some existing rigid-flex circuit boards, to achieve multi-module interconnection, multiple layers of flexible circuit boards are often stacked between rigid circuit boards in the structural design. Although this layout can increase the connection density, it has significant heat dissipation defects. The flexible circuit board itself is composed of an insulating film and a conductive layer, and its thermal conductivity is relatively weak. The multi-layer stacking design results in narrow gaps between adjacent flexible circuit boards. When the equipment is working, the flexible circuit boards bend and twist with the movement of the equipment. The stacked flexible circuit boards are prone to contact and sticking together due to deformation, which will block the air gaps originally used for heat dissipation. Heat cannot be dissipated in time through air convection and will accumulate in the connection area between the flexible circuit board and the rigid circuit board, affecting the stability of the conductive layer of the flexible part. Utility Model Content

[0004] The purpose of this invention is to at least solve one of the aforementioned technical defects.

[0005] Therefore, one objective of this utility model is to provide an ultra-low noise rigid-flex circuit board for a low-temperature control module, so as to solve the problems mentioned in the background art and overcome the shortcomings of the prior art.

[0006] To achieve the above objectives, one embodiment of this utility model provides an ultra-low noise rigid-flex circuit board for a cryogenic control module, comprising two symmetrically arranged rigid circuit boards, two vertically corresponding flexible circuit boards fixedly connected between the two rigid circuit boards, both rigid circuit boards being electrically connected to the two flexible circuit boards, a flexible frame being provided between the two flexible circuit boards, a plurality of linearly arrayed flexible partitions being fixedly connected to the inner wall of the flexible frame, the plurality of flexible partitions being perpendicular to the flexible circuit boards, thermal pads being adhered to the top and bottom surfaces of the flexible frame, the sides of the two thermal pads away from the flexible frame being fixedly connected to the two flexible circuit boards respectively by adhesive, and a wear-resistant layer being embedded in the side of the flexible circuit boards away from the flexible frame.

[0007] Preferably, in any of the above solutions, the bottom surface of the thermal pad is fixedly connected to a limiting protrusion, and the top and bottom surfaces of the flexible frame are provided with limiting grooves that are adapted to the limiting protrusions. The limiting protrusions are bonded to the inner wall of the limiting grooves with thermally conductive adhesive.

[0008] Preferably, in any of the above embodiments, the substrate of the flexible circuit board is made of polyimide, and the conductor layer of the flexible circuit board is made of rolled copper.

[0009] Preferably, in any of the above solutions, the flexible frame is made of silicone, and the flexible partition is made of polyurethane elastomer.

[0010] Preferably, in any of the above embodiments, the thermal pad is a silicone-based thermal pad, and the interior of the thermal pad is filled with boron nitride particles.

[0011] Preferably, the wear-resistant layer is a parylene coating, as described in any of the above embodiments.

[0012] Compared with the prior art, the advantages and beneficial effects of this utility model are as follows: 1. The heat generated by the two flexible circuit boards during operation is transferred through thermal pads bonded to the top and bottom surfaces of the flexible frame. Boron nitride particles inside the thermal pads accelerate heat conduction. Flexible partitions on the inner wall of the flexible frame separate the two circuit boards, preventing them from contacting each other and blocking the heat dissipation gap due to bending or twisting, ensuring airflow and heat dissipation within the gap. Simultaneously, the limiting protrusions on the bottom surface of the thermal pads are embedded in the limiting grooves of the flexible frame and fixed with thermally conductive adhesive, ensuring a tight fit between the thermal pads and the flexible frame and reducing thermal resistance. The flexible partitions effectively maintain the heat dissipation space between the flexible circuit boards. Combined with the high thermal conductivity of the thermal pads, this forms a smooth heat dissipation path from the flexible circuit boards to the flexible frame, solving the problem of poor heat dissipation in traditional multi-layer stacked flexible circuit boards. The cooperation between the limiting protrusions and the limiting grooves ensures the thermal pads are securely installed, preventing poor contact due to vibration and other factors that could affect heat dissipation. This allows heat to dissipate promptly, ensuring the stability of the conductive layer of the flexible circuit board and maintaining the ultra-low noise performance of the circuit board.

[0013] 2. The flexible circuit board uses a polyimide substrate and a rolled copper conductor layer, maintaining good flexibility and conductivity during bending and torsion. The flexible frame is made of silicone, and the flexible partition is made of polyurethane elastomer. Both deform synchronously with the deformation of the flexible circuit board, reducing stress damage. The parylene coating wear-resistant layer on the side of the flexible circuit board away from the flexible frame provides protection when the flexible circuit board comes into contact with other components. The thermal pad is fixed to the flexible circuit board with adhesive, and the positioning of the limiting protrusions and limiting grooves ensures a stable connection of all components. The polyimide substrate and rolled copper conductor layer make the flexible circuit board less prone to damage under frequent deformation. The silicone flexible frame and polyurethane elastomer flexible partition buffer stress, reducing the risk of damage to the flexible circuit board. The parylene coating wear-resistant layer effectively resists friction and wear, extending the service life of the flexible circuit board. The stable connection of each component and the appropriate material selection improve the overall structural stability and durability of the circuit board, ensuring its long-term reliable operation in the cryogenic control module. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the assembly of this utility model; Figure 2 This is a schematic diagram of the structure of the flexible circuit board of this utility model; Figure 3 This is a schematic diagram of the structure at point A of this utility model.

[0015] In the diagram: 1-rigid circuit board, 2-flexible circuit board, 3-flexible frame, 4-flexible partition, 5-thermal pad, 6-wear-resistant layer, 7-limiting protrusion, 8-limiting groove. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited thereto.

[0017] like Figures 1 to 3 As shown, an ultra-low noise rigid-flex circuit board for a low-temperature control module includes two symmetrically arranged rigid circuit boards 1. Two vertically corresponding flexible circuit boards 2 are fixedly connected between the two rigid circuit boards 1. Both rigid circuit boards 1 are electrically connected to the two flexible circuit boards 2. A flexible frame 3 is provided between the two flexible circuit boards 2. A plurality of linearly arrayed flexible partition plates 4 are fixedly connected to the inner wall of the flexible frame 3. The plurality of flexible partition plates 4 are perpendicular to the flexible circuit boards 2. Thermal pads 5 are adhered to the top and bottom surfaces of the flexible frame 3. The sides of the two thermal pads 5 away from the flexible frame 3 are fixedly connected to the two flexible circuit boards 2 respectively by adhesive. A wear-resistant layer 6 is embedded on the side of the flexible circuit board 2 away from the flexible frame 3.

[0018] As an optional technical solution of this utility model, the bottom surface of the thermal pad 5 is fixedly connected with a limiting protrusion 7. The top and bottom surfaces of the flexible frame 3 are both provided with limiting grooves 8 that are adapted to the limiting protrusion 7. The limiting protrusion 7 is bonded to the inner wall of the limiting groove 8 by thermally conductive adhesive. The limiting protrusion 7 on the bottom surface of the thermal pad 5 is adapted to the limiting groove 8 of the flexible frame 3 and is fixed by thermally conductive adhesive. This can accurately position the relative position of the thermal pad 5 and the flexible frame 3, prevent the thermal pad 5 from shifting when the flexible circuit board 2 is bent or vibrated, ensure that the thermal pad 5 is always in close contact with the flexible circuit board 2 and the flexible frame 3, ensure the stability of the heat transfer path, and at the same time, the thermally conductive adhesive can also enhance the heat conduction effect.

[0019] As an optional technical solution of this utility model, the substrate of the flexible circuit board 2 is made of polyimide, and the conductor layer of the flexible circuit board 2 is made of rolled copper. The substrate of the flexible circuit board 2 is made of polyimide, which has excellent low temperature resistance and flexibility, can adapt to the working environment of low temperature control module and withstand frequent bending; the conductor layer is made of rolled copper, which has good conductivity and bending performance, can maintain stable electrical connection during the deformation of the flexible circuit board 2, reduce signal transmission loss, and meet the requirements of ultra-low noise.

[0020] As an optional technical solution of this utility model, the flexible frame 3 is made of silicone, and the flexible partition plate 4 is made of polyurethane elastomer. The flexible frame 3 is made of silicone, which has good flexibility and elasticity and can deform synchronously with the bending of the flexible circuit board 2, thus avoiding rigid pulling on the flexible circuit board 2. The flexible partition plate 4 is made of polyurethane elastomer, which has both elasticity and wear resistance. It can effectively separate the two flexible circuit boards 2 to ensure heat dissipation space, and reduce friction damage between them when the flexible circuit boards 2 deform, thus maintaining structural stability.

[0021] As an optional technical solution of this utility model, the thermal pad 5 is a silicone-based thermal pad, and the interior of the thermal pad 5 is filled with boron nitride particles. The flexibility of the silicone-based material allows it to fit tightly to the surface of the flexible circuit board 2 and the flexible frame 3, filling the tiny gaps to reduce thermal resistance. The boron nitride particles have good thermal conductivity and insulation, which can efficiently conduct the heat generated by the flexible circuit board 2, while avoiding the risk of short circuit caused by the thermal pad 5 conducting electricity.

[0022] As an optional technical solution of this utility model, the wear-resistant layer 6 is a parylene coating. The wear-resistant layer 6 is a parylene coating, which has extremely high wear resistance and chemical stability. It can tightly cover the surface of the flexible circuit board 2, effectively resist the friction generated by the contact between the flexible circuit board 2 and other components during use, protect the conductor layer and substrate of the flexible circuit board 2 from damage, extend the service life of the flexible circuit board 2, and at the same time not affect its electrical performance.

[0023] An ultra-low noise rigid-flex circuit board for a cryogenic control module, the working principle of which is as follows: 1): The heat generated when the two flexible circuit boards 2 are working is transferred through the thermal pads 5 that are bonded to the top and bottom surfaces of the flexible frame 3. The boron nitride particles inside the thermal pads 5 accelerate the heat conduction.

[0024] 2): The flexible partition plate 4 on the inner wall of the flexible frame 3 separates the two flexible circuit boards 2, preventing them from contacting each other and blocking the heat dissipation gap due to bending or twisting, and ensuring that air can circulate and dissipate heat in the gap.

[0025] 3): At the same time, the limiting protrusion 7 on the bottom surface of the thermal pad 5 is embedded in the limiting groove 8 of the flexible frame 3 and fixed by thermal adhesive to ensure that the thermal pad 5 and the flexible frame 3 are tightly attached to each other and reduce thermal resistance.

[0026] In summary, this low-temperature control module uses an ultra-low noise rigid-flex circuit board. The heat generated by the two flexible circuit boards 2 during operation is transferred through the thermal pads 5 bonded to the top and bottom surfaces of the flexible frame 3. The boron nitride particles inside the thermal pads 5 accelerate heat conduction. The flexible partition plate 4 on the inner wall of the flexible frame 3 separates the two flexible circuit boards 2, preventing them from contacting each other due to bending or twisting and blocking the heat dissipation gap, ensuring that air can circulate and dissipate heat within the gap. At the same time, the limiting protrusion 7 on the bottom surface of the thermal pad 5 is embedded in the limiting groove 8 of the flexible frame 3 and fixed with thermally conductive adhesive, ensuring that the thermal pad 5 and the flexible frame 3 are tightly attached, reducing thermal resistance. The flexible partition 4 effectively maintains the heat dissipation space between the flexible circuit boards 2. Combined with the high thermal conductivity of the thermal pad 5, it forms a smooth heat dissipation path from the flexible circuit board 2 to the flexible frame 3, solving the problem of poor heat dissipation in traditional multi-layer stacked flexible circuit boards. The cooperation between the limiting protrusion 7 and the limiting groove 8 ensures that the thermal pad 5 is installed firmly, avoiding poor contact due to vibration and other factors that may affect heat dissipation. This allows heat to dissipate in a timely manner, ensuring the stability of the conductive layer of the flexible circuit board 2, and thus maintaining the ultra-low noise performance of the circuit board. The flexible circuit board 2 uses a polyimide substrate and a rolled copper conductor layer, which can maintain good flexibility and conductivity when bent and twisted. The flexible frame 3 is made of silicone, and the flexible partition 4 is made of polyurethane elastomer. Both deform synchronously with the deformation of the flexible circuit board 2, reducing stress damage to the flexible circuit board 2. The parylene coating wear-resistant layer 6 on the side of the flexible circuit board 2 away from the flexible frame 3 provides protection when the flexible circuit board 2 comes into contact with and rubs against other components. The thermal pad 5 is fixed to the flexible circuit board 2 with adhesive, and the positioning of the limiting protrusion 7 and the limiting groove 8 ensures that the connection of each component is firm. The polyimide substrate and rolled copper conductor layer make the flexible circuit board 2 less prone to damage under frequent deformation. The flexible frame 3 made of silicone and the flexible partition plate 4 made of polyurethane elastomer can buffer stress and reduce the risk of damage to the flexible circuit board 2. The parylene coating wear-resistant layer 6 effectively resists friction and wear, extending the service life of the flexible circuit board 2. The stable connection of each component and the appropriate material selection improve the overall structural stability and durability of the circuit board, ensuring its long-term reliable operation in the low-temperature control module.

Claims

1. An ultra-low noise rigid-flex circuit board for a cryogenic control module, characterized in that: The device includes two symmetrically arranged rigid circuit boards (1), and two corresponding flexible circuit boards (2) are fixedly connected between the two rigid circuit boards (1). The two rigid circuit boards (1) are electrically connected to the two flexible circuit boards (2). A flexible frame (3) is provided between the two flexible circuit boards (2). A number of linear array flexible partition plates (4) are fixedly connected to the inner wall of the flexible frame (3). The number of flexible partition plates (4) are perpendicular to the flexible circuit boards (2). A heat-conducting pad (5) is bonded to the top and bottom surfaces of the flexible frame (3). The side of the two heat-conducting pads (5) away from the flexible frame (3) is fixedly connected to the two flexible circuit boards (2) by glue. A wear-resistant layer (6) is embedded on the side of the flexible circuit board (2) away from the flexible frame (3).

2. The ultra-low noise rigid-flex circuit board for a cryogenic control module according to claim 1, characterized in that: The bottom surface of the heat-conducting pad (5) is fixedly connected to a limiting protrusion (7), and the top and bottom surfaces of the flexible frame (3) are provided with limiting grooves (8) that are adapted to the limiting protrusions (7). The limiting protrusions (7) are bonded to the inner wall of the limiting grooves (8) by thermally conductive adhesive.

3. The ultra-low noise rigid-flex circuit board for a cryogenic control module according to claim 2, characterized in that: The substrate of the flexible circuit board (2) is made of polyimide, and the conductor layer of the flexible circuit board (2) is made of rolled copper.

4. The ultra-low noise rigid-flex circuit board for a cryogenic control module according to claim 3, characterized in that: The flexible frame (3) is made of silicone, and the flexible partition (4) is made of polyurethane elastomer.

5. The ultra-low noise rigid-flex circuit board for a cryogenic control module according to claim 4, characterized in that: The thermal pad (5) is a silicone-based thermal pad, and the interior of the thermal pad (5) is filled with boron nitride particles.

6. The ultra-low noise rigid-flex circuit board for a cryogenic control module according to claim 5, characterized in that: The wear-resistant layer (6) is a parylene coating.

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