Special-shaped curved surface cross-scale three-dimensional integrated splicing structure and method

Abstract

The invention discloses a special-shaped curved surface cross-scale three-dimensional integrated splicing structure and method, and relates to the technical field of curved surface integrated manufacturing, the special-shaped curved surface cross-scale three-dimensional integrated splicing structure comprises a mounting base and a plurality of miniature flexible suction cups connected to the mounting base, and a suction cup array formed after the miniature flexible suction cups are connected to the mounting base is determined according to the shape of a flexible film component. And each flexible film component is adsorbed by a plurality of micro flexible suckers. High-precision, low-heat-loss and low-insertion-loss interconnection between film components is achieved, the aim of cross-scale three-dimensional integrated splicing on the special-shaped curved surface is achieved, the integration precision of the film can be effectively improved, and the integration stress of the film is reduced.

Description

Technical Field

[0001] The present invention relates to a method for cross-scale three-dimensional integrated splicing of special-shaped curved surfaces, and the technical field is curved surface integrated manufacturing technology. Background Art

[0002] Flexible functional electronic films generally consist of flexible substrate materials, fine metal structures and semiconductor devices. The fine metal structures are plated on the surface of the flexible substrate materials and welded to the semiconductor devices to form an electronic circuit structure with certain electrical functions, which has broad application prospects in the aerospace field, such as: spacecraft skins, spacecraft electromagnetic protection, etc. In these application fields, the integration of flexible functional films cannot affect the self-performance of the integration / protection target (hereinafter referred to as "target"), so conformal integration is required. However, the integration targets, such as spacecraft, present the characteristics of "special-shaped" and "curved surfaces", so the film can neither be in-situ manufactured on the target surface nor can the overall manufacturing and integration of special-shaped films be completed.

[0003] Currently, the commonly used complex structure curved surface integrated packaging technologies mainly include conductive adhesive interconnection technology, low-temperature eutectic solder interconnection technology, and surface printing and mounting technology based on nano-sintering, etc. Conductive adhesive interconnection is an interconnection process based on organic polymerization reaction, which can achieve high-conductivity interconnection of various material devices on different structure surfaces under the condition of relatively low process temperature (<200°C), but it has problems such as poor structural stability, low mechanical reliability, and easy misalignment of the structure during the curing process. Solder and nano-ink printing interconnection technologies have lower requirements for the surface roughness and flatness of the substrate, the diffusion and chemical reactions are relatively sufficient, the residual stress of the solder joints is small, the bonding strength is high, and the structural integrity and reliability are good; however, they have problems such as insufficient electro-thermal transmission performance of the connection joints, many large-size volatile voids, etc., and are prone to deformation, cracking, and falling off during service or aging, and it is difficult to take into account the requirements of complex structure integration in terms of shape, accuracy, and service performance. Summary of the Invention

[0004] The technical problem solved by this application is: overcoming the deficiencies of the prior art, providing a special-shaped curved surface cross-scale three-dimensional integrated splicing structure and method, establishing a rigid directional adsorption structure and an array constraint model considering space interference, breaking through the in-situ array vacuum synchronous suction and adaptive conformal transfer technology, clarifying the non-equilibrium three-dimensional forming mechanism of cross-scale butt welds, and realizing the process-stress collaborative design and tissue performance synchronous regulation of the integrated structure of the protection components.

[0005] Based on the difficult problems of curved surface integrated manufacturing, this technology proposes a method of first preparing small flexible film components in pieces and then performing cross-scale three-dimensional integrated splicing of the flexible film components on special-shaped curved surfaces.

[0006] The technical solutions provided by this application are as follows:

[0007] A special-shaped curved surface cross-scale three-dimensional integrated splicing structure, comprising a mounting base and a plurality of micro flexible suction cups connected to the mounting base. The suction cup array formed after the plurality of micro flexible suction cups are connected to the mounting base is determined according to the shape of the flexible film element, and each flexible film element is adsorbed by a plurality of micro flexible suction cups; the micro flexible suction cups are used to transfer the flexible film element to the surface of the target curved surface.

[0008] Further, each of the micro flexible suction cups includes a movable connecting rod, a vacuum suction cup and a pneumatic clamping device. A plurality of through holes are provided on the mounting base, and a movable connecting rod is slidably connected in each through hole. Both ends of the movable connecting rod are located on both sides of the mounting base. One end of the movable connecting rod is ball-jointed with a vacuum suction cup, and the other end is provided with a limiting portion. The diameter of the limiting portion is larger than the diameter of the through hole. The vacuum suction cup is used to adsorb the flexible film element; the pneumatic clamping device is connected to the mounting base and is used to clamp the movable connecting rod so that the movable connecting rod is relatively fixed to the mounting base.

[0009] Further, the pneumatic clamping device is controlled by a solenoid valve, and all the pneumatic clamping devices are driven by the same controller and controlled by a pulse width modulation signal to achieve fine adjustment of flow rate and pressure.

[0010] Further, the mounting base is connected with a five-axis robotic arm, and the five-axis robotic arm is used to drive the mounting base to move.

[0011] Further, the maximum area of each flexible film element can reach 1500 cm 2 , and the diameter range of the vacuum suction cup is between 0.05 and 1 cm.

[0012] A special-shaped curved surface cross-scale three-dimensional integrated splicing method, which is spliced according to the special-shaped curved surface cross-scale three-dimensional integrated splicing structure described in any one of the above, comprising:

[0013] S1. Decompose the model of the flexible film to obtain the model of the small-sized flexible film element, and prepare the small-sized flexible film element according to the model of the flexible film element; each flexible film element includes a sub-flexible substrate and a sub-electrical structure located on one surface of the sub-flexible substrate, and a fine metal pad array structure is prepared at the edge of the flexible film element. The fine metal pad array structure includes a plurality of pads, and the pads are connected to the sub-electrical structure on the surface of the flexible film element;

[0014] S2. Spray a thin layer of curable adhesive on the surface of the target curved surface;

[0015] S3. Use a suction cup array to adsorb a single flexible film component and drive the flexible film component to move to a preset position on the target curved surface, and place the flexible film component on the surface of the target curved surface. At this time, the flexible film component is bonded to the target surface through a cured adhesive;

[0016] S4. Repeat S3 until all flexible film components are transferred to the target curved surface;

[0017] S5. Use the method of laser pulse induced micro-droplets to perform segmented continuous deposition between the pads that need to be connected between the flexible film components.

[0018] Further, in S3, using a suction cup array to adsorb a single flexible film component and drive the flexible film component to move to a preset position on the target curved surface includes:

[0019] Make the pneumatic clamping device in a state of loosening the movable connecting rod, so that the entire mounting base moves towards the direction close to the flexible film component until it is visually recognized that all vacuum suction cups are attached to the flexible film component, and then control the pneumatic clamping device to clamp the movable connecting rod; control the movement of the mounting base to drive the flexible film component to move to a preset position on the target curved surface, and press down the micro flexible suction cup and then release the adsorption of the flexible film component.

[0020] Further, in S1, chemically roughen the back surface of the prepared flexible film component.

[0021] Further, the cured adhesive is a nitrile group-containing polyarylether adhesive.

[0022] In summary, the present application includes at least the following beneficial technical effects:

[0023] (1) The present invention uses a dynamic flexible suction cup array to achieve conformal transfer of segmented electronic film components, which can effectively improve the integration accuracy of the film and reduce the integration stress of the film.

[0024] (2) The present invention uses the technology of laser micro-droplet three-dimensional docking and interconnection to achieve high-precision, low thermal loss, and low insertion loss interconnection between film components, and realizes the goal of cross-scale three-dimensional integrated splicing on a special-shaped curved surface.

[0025] (3) By combining high-resolution characterization technology with high-precision simulation technology, the optimal process parameters of laser micro-droplet three-dimensional integrated interconnection are extracted, and the feasibility of the cross-scale three-dimensional integrated splicing technology for special-shaped curved surfaces is verified. Brief Description of the Drawings

[0026] Figure 1 It is a schematic diagram of the directional adsorption structure and the suction cup array;

[0027] Figure 2Schematic diagram of the process for low-stress transfer of components using a suction cup;

[0028] Figure 3 Schematic diagram of the adhesive spraying process;

[0029] Figure 4 Schematic diagram of the three-dimensional interconnection process of laser-induced micro-droplets and the weld interface morphology;

[0030] Figure 5 Schematic diagram of the three-dimensional interconnection process of laser-induced micro-droplets;

[0031] Figure 6 Schematic diagram of the specific structure of the micro flexible suction cup.

[0032] Explanation of the reference numerals in the attached drawings: 1. Micro flexible suction cup; 11. Movable connecting rod; 12. Vacuum suction cup; 13. Pneumatic clamping device;

[0033] 2. Installation base; 3. Five-axis robotic arm; 4. Flexible film component; 5. Surface of the target curved surface. Specific implementation manner

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will further describe in detail the disclosed implementation manners of the present invention in conjunction with the accompanying drawings.

[0035] This application embodiment discloses a method for cross-scale three-dimensional integrated splicing of a special-shaped curved surface, aiming at the cross-scale three-dimensional integrated splicing of a flexible electronic functional film on a special-shaped target curved surface, and establishing an orientation adsorption structure and an array model considering spatial interference, as Figure 1 shown. Using the vacuum adaptive conformal transfer technology and automated equipment, the in-situ array synchronous suction and non-deformation conformal transfer of the flexible film component 4 are realized, as Figure 2 shown. Using a high-precision spraying equipment to selectively spray a thin layer of photocurable adhesive on the surface 5 of the target curved surface, as Figure 3 shown, and using the optimal adhesive component and curing process window to complete the high-precision positioning and bonding curing of the component on the target special-shaped curved surface structure. Using the low-stress connection process for the cross-scale butt weld of the special-shaped curved surface, the three-dimensional forming of metal micro-droplets in the butt weld between components is realized under the condition of energy-structure non-equilibrium, as Figure 4 shown.

[0036] As Figure 1 and Figure 2As shown, the adsorption structure array includes a mounting base 2 and a plurality of micro flexible suction cups 1 connected to the mounting base 2. The plurality of micro flexible suction cups 1 form a suction cup array on the mounting base 2. The suction cup array includes a square array, a circular array, etc. According to the shape requirements of the flexible film component, the size and array shape of the suction cup array are determined. For example, when the curved surface is arc-shaped, the micro flexible suction cups 1 form a circular array consistent with the shape of the curved surface. The mounting base 2 is connected to the driving structure. In this embodiment, the driving structure is a five-axis robotic arm 3.

[0037] As Figure 6 shown, each micro flexible suction cup 1 includes a movable connecting rod 11, a vacuum suction cup 12 and a pneumatic clamping device 13. A plurality of through holes are formed in the mounting base 2, and a movable connecting rod 11 is slidably connected in each through hole. Both ends of the movable connecting rod 11 are located on both sides of the mounting base 2. One end of the movable connecting rod 11 is ball-jointed with a vacuum suction cup 12, and the other end is provided with a limiting portion. The diameter of the limiting portion is larger than the diameter of the through hole to prevent the movable connecting rod 11 from slipping out of the through hole. The vacuum suction cup 12 is used to adsorb the flexible film component; the pneumatic clamping device 13 is connected to the mounting base 2 and is used to relatively fix the movable connecting rod 11 and the mounting base 2.

[0038] The pneumatic clamping device 13 includes a solenoid valve and a controller. All pneumatic clamping devices are driven by the same controller and controlled by a pulse width modulation signal to achieve fine adjustment of flow rate and pressure.

[0039] The maximum area of each flexible film component can reach 1500 cm 2 , the diameter range of the vacuum suction cup 12 is between 0.05 and 1 cm, and the diameter of the movable connecting rod 11 is 0.5 to 2 cm. The size of each flexible film component is small, and the film material has a certain stiffness, making the whole relatively not easy to deform. Combined with the above-mentioned micro size of the vacuum suction cup 12, each micro flexible suction cup 1 can adjust its accurate position following the surface shape of the flexible film component. The micro flexible suction cup 1 drives the flexible film component to move to the target curved surface, and after pressing down the micro flexible suction cup 1, the adsorption to the flexible film component is released; during this process, the micro flexible suction cup 1 can make the pressing degree between each part of the flexible film component and the target curved surface highly consistent, ensuring the bonding effect of the flexible film component.

[0040] Each flexible film component is adsorbed by a plurality of micro flexible suction cups 1, so that each micro flexible suction cup can suck the flexible film component under low stress, enabling the flexible film component to receive uniform suction force, minimizing the deformation of the electronic film component during the transfer process, and achieving conformal coating of the flexible film component on the target curved surface.

[0041] The specific technical solution is as follows:

[0042] (1) Spray a photocurable adhesive on the target surface.

[0043] (2) Design a dynamic flexible suction cup array to achieve conformable and non-destructive adsorption and fixation of heterogeneous and flexible components, and complete the high-precision and adaptive conformal transfer, positioning, and pasting of flexible film components.

[0044] (3) Based on a multi-axis linkage displacement platform and a high-power ultra-short pulse laser, adopt the laser pulse-induced micro-droplet three-dimensional docking and interconnecting technology. As Figure 5 shown, control the high-precision segmented continuous deposition of metal micro-droplets in the element gaps to achieve in-situ solder coating and low-stress synchronous connection of a specific fine metal pad array structure.

[0045] A method for cross-scale three-dimensional integrated splicing of heterogeneous curved surfaces, specifically including:

[0046] The base material of the flexible film is a flexible substrate material represented by polyimide. First, decompose the model of the flexible film to obtain the models of small-sized flexible film components. Prepare small-sized flexible film components according to the models of the flexible film components. Each flexible film component includes a sub-flexible base and a sub-electrical structure located on one surface of the sub-flexible base. And a fine metal pad array structure is prepared at the edge of the flexible film component. The fine metal pad array structure includes multiple pads, and the pads are connected to the sub-electrical structure on the surface of the flexible film component. Thus, through the welding between the pads at the edges of adjacent flexible film components, the sub-electrical structures on the flexible film components are connected to form the entire electrical structure on the flexible film. The sizes of different flexible film components may be different, and the flexible film components need to be integrated on a three-dimensional curved surface, so it is called: cross-scale three-dimensional integrated splicing. The integrated splicing target surface of the flexible film has the characteristics of a large size and a heterogeneous curved surface. The first step of this technical solution is to achieve the bonding between the components and the target, and the second step is to achieve the highly reliable interconnection between the components.

[0047] (1) Spray a thin layer of curable adhesive 6 on the surface 5 of the target curved surface, as Figure 3As shown, the flexible film components are adsorbed through the directional adsorption structure and the array model, and driven to move to the preset position on the target surface, and bonded to the target surface through the curing adhesive. The back surface of the flexible film component (the surface where the sub-electrical structure is not provided on the sub-flexible substrate) is its bonding surface with the target. The bonding surface is chemically roughened to reduce its surface tension, so that it self-fills at the bonding interface between the component and the target, realizing high-reliability and high-precision bonding between the two. The adhesive has process characteristics such as room-temperature glue application operation, small influence of curing temperature on the thermal deformation of the polyimide film, bonding strength to the polyimide film not less than the tensile strength of the polyimide film body, Tg not less than 150 °C, and small curing shrinkage. Under this requirement, a nitrile-group-containing polyarylether adhesive is selected. This adhesive has an aromatic ring and a flexible alkane as the main chain. The flexible alkane chain makes the softening point of the adhesive low, with good operability at room temperature and certain self-adhesion. The side groups of the adhesive are reactive active groups such as nitrile groups and amino groups, which can provide strong adhesion to the polyimide film.

[0048] (2) The polyimide film material cannot be thermocompression spliced. To ensure the flatness of the connection between components on the target surface, splicing is carried out along the length direction of the film material in a butt joint manner. The edges of the components are prepared with a fine metal pad array structure. The laser pulse-induced microdroplet three-dimensional butt joint interconnection technology is used to control the high-precision segmented continuous deposition of metal microdroplets between the pads that need to be welded and connected on the flexible film components, as Figure 5 shown. The in-situ solder coating and low-stress synchronous connection of a specific fine metal pad array structure are realized. The laser pulse-induced microdroplet three-dimensional butt joint interconnection technology is jointly realized based on a multi-axis linkage displacement platform and a high-power ultra-short pulse laser.

[0049] The morphological, dimensional, contact angle and other structural feature changes of the microdroplet continuous deposition structure and the butt joint weld gap interface at different stages are characterized by a laser confocal microscope and microarea sectioning technology, and the shape evolution process of the microdroplets and the butt joint gap at each stage of continuous deposition is restored. The dynamic change process of the temperature field in the butt joint area between components under the comprehensive spatio-temporal effect of continuous transient concentrated heat sources is tested and analyzed, a metal microdroplet continuous heat source model and a local heat-flow model of the butt joint weld are constructed, and the energy state and temperature distribution law of the component butt joint interface under the action of continuous microdroplet heat flow are obtained.

[0050] On the other hand, microscopic characterization techniques such as SEM, TEM, and EBSD are used to analyze the microscopic organizational structure of the butt joint, and the influence law of the energy input change caused by the dynamic temperature change on the droplet solidification process and the organizational structure of the solder joints is obtained.

[0051] Extract the mapping relationship between different process parameters (transfer angle, speed, micro-droplet size, gap size, stacking spacing, etc.) and the interface temperature distribution law. Optimize the in-situ integration process parameters according to the results, control the micro-droplet stacking structure and tissue composition of the weld, and achieve high-performance structure-process collaborative design and synchronous regulation of tissue properties.

[0052] The content not described in detail in the specification of this application belongs to the well-known technology of those skilled in the art.

[0053] The above has described this application in detail in combination with specific implementation manners and exemplary examples, but these descriptions should not be construed as limitations on this application. Those skilled in the art understand that without departing from the spirit and scope of this application, various equivalent substitutions, modifications or improvements can be made to the technical solutions of this application and their implementation manners, and these all fall within the scope of this application. The protection scope of this application is subject to the appended claims.

Claims

1. A special-shaped curved surface cross-scale three-dimensional integrated splicing structure, characterized in that: It includes an installation base (2) and a plurality of micro flexible suction cups (1) connected to the installation base (2). The suction cup array formed after the plurality of micro flexible suction cups (1) are connected to the installation base (2) is determined according to the shape of the flexible film component. Each flexible film component (4) is adsorbed by a plurality of micro flexible suction cups (1). The micro flexible suction cup (1) is used to transfer the flexible film component (4) onto the surface of the target curved surface.

2. The special-shaped curved surface cross-scale three-dimensional integrated splicing structure according to claim 1, wherein: Each of the micro flexible suction cups (1) includes a movable connecting rod (11), a vacuum suction cup (12) and a pneumatic clamping device (13). A plurality of through holes are formed in the installation base (2), and a movable connecting rod (11) is slidably connected in each through hole. The two ends of the movable connecting rod (11) are respectively located on both sides of the installation base (2). One end of the movable connecting rod (11) is ball-jointed with the vacuum suction cup (12), and the other end is provided with a limiting part. The diameter of the limiting part is larger than the diameter of the through hole. The vacuum suction cup (12) is used to adsorb the flexible film component. The pneumatic clamping device (13) is connected to the installation base (2) and is used to clamp the movable connecting rod (11) so that the movable connecting rod (11) is relatively fixed to the installation base (2).

3. The heterogeneous curved surface cross-scale three-dimensional integrated splicing structure according to claim 2, wherein: The pneumatic clamping device (13) is controlled by a solenoid valve. All pneumatic clamping devices are driven by the same controller and are controlled by a pulse width modulation signal to achieve fine adjustment of flow rate and pressure.

4. A special-shaped curved surface cross-scale three-dimensional integrated splicing structure according to claim 1, characterized in that: The installation base (2) is connected with a five-axis robotic arm (3), and the five-axis robotic arm (3) is used to drive the installation base (2) to move.

5. A special-shaped curved surface cross-scale three-dimensional integrated splicing structure according to claim 1, characterized in that: The maximum area of each of the flexible film components can reach 1500 cm 2 , and the diameter range of the vacuum chuck (12) is between 0.05 and 1 cm.

6. A method for splicing heterogeneous curved surfaces across scales and integrating them three-dimensionally, characterized in that, When splicing according to the special-shaped curved surface cross-scale three-dimensional integrated splicing structure according to any one of claims 1-5, it includes: S1. Decompose the model of the flexible film to obtain the model of the small-sized flexible film component. Prepare the small-sized flexible film component according to the model of the flexible film component. Each flexible film component includes a sub-flexible substrate and a sub-electrical structure located on one side surface of the sub-flexible substrate. And a fine metal pad array structure is prepared at the edge of the flexible film component. The fine metal pad array structure includes a plurality of pads, and the pads are connected to the sub-electrical structure on the surface of the flexible film component. S2. Spray a thin layer of curable adhesive on the surface of the target curved surface. S3. Use the suction cup array to adsorb a single flexible film component and drive the flexible film component to move to a preset position on the target curved surface, and place the flexible film component on the surface of the target curved surface. At this time, the flexible film component is bonded to the target surface through the curable adhesive. S4. Repeat S3 until all flexible film components are transferred to the target curved surface. S5. Use the method of laser pulse-induced micro droplets to perform segmented continuous deposition between the pads that need to be connected between the flexible film components.

7. The special-shaped curved surface cross-scale three-dimensional integrated splicing structure according to claim 6, characterized in that In step S3, using the suction cup array to adsorb a single flexible film component and drive the flexible film component to move to a preset position on the target curved surface includes: Put the pneumatic clamping device (13) in a state of releasing the movable connecting rod (11), so that the entire mounting base (2) moves towards the flexible film component until it is visually recognized that all vacuum suction cups (12) are attached to the flexible film component, and then control the pneumatic clamping device (13) to clamp the movable connecting rod (11); control the movement of the mounting base (2) to drive the flexible film component to move to a preset position on the target curved surface, and press down the micro flexible suction cup (1) and then release the adsorption of the flexible film component.

8. A method for assembling a special-shaped curved surface across scales in a three-dimensional integrated manner according to claim 6, characterized in that: In S1, chemically roughen the back surface of the prepared flexible film component.

9. A method for splicing heterogeneous curved surfaces across scales and three-dimensionally integrating according to claim 6, characterized in that: The curing adhesive is a nitrile group-containing polyarylether adhesive.

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