Curved surface circuit processing device and method

Abstract

The invention belongs to the field of aeronautical manufacturing, and particularly relates to a curved surface circuit machining device and method. According to the device, a device conveying device, a smoke exhaust device, a six-axis mechanical arm, a pneumatic dispensing machine and a three-axis motion platform are mounted in a closed box body; a traditional process of surface metallization, circuit etching, solder coating, surface mounting and welding is simplified into a process of wire direct writing, surface mounting and welding. The core of the method is that the conductive ink is used as a conductive circuit and a device solder at the same time, adaptive manufacturing of a complex three-dimensional structure can be realized by adopting the conductive ink based on a micro-pen direct writing technology, and the forming precision of the circuit can reach 90 microns; the conductivity of the conducting circuit manufactured through direct writing can reach 8.4 * 10 < 6 > S / m; the integrated manufacturing device can realize automatic operation of curved circuit direct writing, device patch fixing and sintering connection, and can adapt to the manufacturing requirements of various complex curvature structures. Device connection and circuit manufacturing are synchronously carried out, and the manufacturing efficiency is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of aerospace manufacturing, specifically relating to a surface circuit processing device and method, which is applied to the direct writing manufacturing of surface circuits in complex curved three-dimensional circuits and the connection of micro-devices in the circuit. Background Technology

[0002] With the increasing complexity, three-dimensionality, and greenness of electronic products, electronic additive manufacturing technology has the advantages of high material utilization, good adaptability to complex structures, and green environmental protection compared with traditional circuit etching and printing technology. Among them, conductive ink printing direct writing technology can meet the application requirements of curved circuit manufacturing due to its high forming accuracy and maskless characteristics. At the same time, conductive ink can also be used for sintering connection of components and circuits, realizing the simultaneous connection of components and circuit manufacturing, which greatly improves the efficiency of electronic manufacturing.

[0003] Traditional circuit manufacturing technologies typically include processes such as wire preparation, solder coating, component placement, and component soldering, with most mature processes designed for planar PCBs. In recent years, with the development of conformal electronics technology, circuit manufacturing technologies for curved surfaces have gradually emerged.

[0004] There is an urgent need for an integrated device suitable for the manufacturing of curved circuits and the connection of micro-devices to meet the needs of integrated manufacturing of curved electronics. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that traditional circuit manufacturing technology has many processes, low manufacturing efficiency, and cannot complete the preparation of curved circuits on a single set of equipment. The present invention proposes a curved circuit processing device and method.

[0006] This invention proposes a curved circuit processing device. The device comprises a component conveying device, a fume extraction device, a six-axis robotic arm, a pneumatic dispensing machine, and a three-axis motion platform, all housed in a closed enclosure. The three-axis motion platform has a heating pad on which a workpiece is placed. A direct-writing device is formed by the pneumatic dispensing machine and a dispensing syringe. The six-axis robotic arm clamps the dispensing syringe and extrudes conductive ink onto the workpiece surface, forming conductive ink lines. The six-axis robotic arm grips a clamping jaw with a central air pressure pipe and two side hot air pipes. When the clamping jaw grasps a micro-device, the air pressure pipes provide negative pressure for adsorption. When the clamping jaw fixes the micro-device onto the conductive ink lines, the air pressure pipes provide positive pressure. After mounting the micro-device via the hot air pipes, it is pre-sintered and then cured as a whole by the heating pad, forming conductive ink lines.

[0007] Advantageously, the device conveying device includes a first traction wheel, a conveying wheel group, a sealing film traction wheel, and a second traction wheel. The micro-device strip is mounted on the first traction wheel and the second traction wheel and supported by the conveying wheel group. The sealing bag on the surface of the micro-device strip is torn open and fixed to the sealing bag traction wheel.

[0008] Advantageously, the pneumatic dispensing machine is pressurized by an external air pump connected to the air circuit interface.

[0009] Advantageously, the gripper employs a gripping scheme that combines mechanical clamping with vacuum adsorption.

[0010] Advantageously, the enclosed enclosure has a base and also includes a monitoring system, an interactive panel, and a control cabinet, the monitoring system being used to observe the processing in real time.

[0011] Advantageously, the conductive ink is selected from conductive silver ink, conductive copper ink, or conductive carbon paste.

[0012] The present invention also proposes a method for fabricating curved circuits, using the aforementioned curved circuit fabrication apparatus, the method comprising the following steps: S1. Prepare the direct writing device; S2. Mount the micro-device strip onto the device transport device; S3. Place the workpiece on the heating pad of the three-axis motion platform and fix it. Adjust the needle tip position and coordinates of the dispensing syringe through the six-axis robotic arm. Set the motion program and direct writing speed of the dispensing syringe and run it for trial until there is no motion interference. S4. Turn on the exhaust device, set the dispensing process and extrusion pressure, and use the six-axis robotic arm to drive the dispensing syringe to form conductive ink lines on the workpiece surface. S5. Replace the dispensing syringe at the end of the six-axis robotic arm with a gripper, and use the gripper to transfer the micro-device and pre-sinter it to the designated patch position on the workpiece. S6. Adjust the temperature of the heating pad and set the heating time to sinter the conductive ink circuit into a conductive circuit. The micro-device and the conductive ink circuit are sintered simultaneously.

[0013] Advantageously, in S1, conductive ink is loaded into a dispensing syringe, a dispensing needle of appropriate specification is selected according to the design of the direct-write conductive circuit, the dispensing syringe is fixed to the end of the six-axis robotic arm, and the air circuit connection between the dispensing syringe and the pneumatic dispensing machine and the external air pump is checked to ensure that the connection is complete.

[0014] Advantageously, in S2, the microdevice strip is mounted on the first traction wheel and the second traction wheel, and supported by the transmission wheel set, and the sealing bag on the surface of the microdevice strip is torn open and fixed to the sealing bag traction wheel.

[0015] Advantageously, in S5, the micro-device is held by the gripper claw, and the micro-device is picked up by adjusting the air pressure in the air pressure pipe to a negative pressure state. After transfer and mounting, the air pressure in the central air path pipe is adjusted to a positive pressure state to press the micro-device. The hot air blown out by the hot air pipe initially realizes the pre-sintering of the micro-device and the conductive ink circuit.

[0016] Beneficial effects: Significantly simplifies the manufacturing process of curved circuits, reducing the traditional "surface metallization-circuit etching-solder coating-surfacing-soldering" process to "direct writing of conductors-surfacing-soldering". Its core lies in using conductive ink as both conductive circuitry and device solder. Based on micropen direct writing technology, conductive ink enables the adaptive manufacturing of complex three-dimensional structures, achieving a circuit forming accuracy of up to 90μm; the conductivity of the conductive circuits manufactured through direct writing can reach 8.4×10⁶ S / m; the integrated manufacturing device automates the direct writing of curved circuits, device surface mounting, and sintering connections, and can adapt to the manufacturing needs of various complex curvature structures.

[0017] The conductive ink printing direct writing technology features high forming precision and no mask template, which can meet the application requirements of curved circuit manufacturing. At the same time, conductive ink can also be used for sintering connection of components and circuits, realizing the simultaneous connection of components and circuit manufacturing, which greatly improves manufacturing efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the curved surface circuit processing device of the present invention; Figure 2 ad is a schematic diagram of the curved surface circuit processing of the present invention; Figure 3 A linewidth diagram of a silver conductor circuit manufactured by direct writing using the processing apparatus of the present invention; Figure 4 A statistical chart of the conductivity of silver conductive circuits; Figure 5 This is a sample drawing of a curved circuit. Figure 6 This is a sample diagram of the connection between curved circuits and devices.

[0019] 1. Box base; 2. First traction wheel; 3. Micro-device strip; 4. Conveyor wheel assembly; 5. Sealing membrane traction wheel; 6. Monitoring system; 7. Second traction wheel; 8. Smoke exhaust device; 9. Six-axis robotic arm; 10. Circuit cable; 11. Air interface; 12. Pneumatic dispensing machine; 13. Interactive panel; 14. Control cabinet; 15. Heating pad; 16. Three-axis workpiece motion platform; 17. Dispensing syringe; 18. Workpiece; 19. Conductive ink circuit; 20. Pneumatic pipeline; 21. Gripping jaws; 22. Hot air pipeline; 23. Micro-device; 24. Conductive circuit. Detailed Implementation The curved surface circuit processing device and method of the present invention are designed to solve the problem of integrated manufacturing of surface circuits and functional devices for complex curved surface structures. The following description, in conjunction with specific embodiments and accompanying drawings, further illustrates the device and its applicability.

[0020] The curved surface circuit processing device of the present invention, as shown in the figure Figure 1 As shown, it specifically includes: The base of the enclosure 1 is equipped with a device or system support, including a component conveying device, a monitoring system 6, a smoke exhaust device 8, a six-axis robotic arm 9, a pneumatic dispensing machine 12, an interactive panel 13, a control cabinet 14, a three-axis motion platform 16, and circuit cables 10, as well as physical isolation between people and machines during operation.

[0021] The device conveying device is used for mounting the micro-device strip 3, peeling off the sealing film, and conveying the micro-device to the designated feeding position. It includes a first traction wheel 2, a conveying wheel group 4, a sealing film traction wheel 5, and a second traction wheel 7.

[0022] Monitoring system 6 is mainly used for real-time observation of the processing process.

[0023] The smoke exhaust device 8 is mainly used to absorb and exhaust the smoke generated by the decomposition of internal organic matter during the sintering of conductive ink.

[0024] The six-axis robotic arm 9 is used for manufacturing curved circuits. The actuators include the installation, posture control, and multi-degree-of-freedom motion of the dispensing syringe 17 and the gripper 21.

[0025] A direct-writing device is composed of a pneumatic dispensing machine 12 and a dispensing syringe 17. The pneumatic dispensing machine 12 is pressurized by an external air pump connected to the air circuit interface 11. The air pressure forces the conductive ink in the dispensing syringe 17 out of the needle and onto the surface of the workpiece 18, forming a conductive ink line 19. The dispensing syringe 17 is fixed to the end of the six-axis robotic arm 9, forming an air circuit connection with the pneumatic dispensing machine 12 and the air pump.

[0026] The clamping claw 21 has a pneumatic pipe 20 in the middle and hot air pipes 22 on both sides for gripping, mounting, and pre-sintering the micro-device 23. To accommodate different types of devices and ensure a high success rate for picking up and mounting, a combination of mechanical clamping and vacuum adsorption is used. First, the clamping claw 21 holds both ends of the micro-device 23, and then a negative pressure suction force is applied to the micro-device 23 through the central hole of the clamping claw 21. The hot air pipes 22 are used for local heating of the micro-device 23 after mounting, realizing the pre-sintering of the micro-device 23 on the conductive ink circuit 19.

[0027] The three-axis motion platform 16 is used for placing and adjusting the posture of the workpiece to be processed. Its surface has a heating pad 15, which is used to heat the entire workpiece.

[0028] The process of manufacturing curved circuits based on the curved circuit processing device of the present invention is as follows: Figure 2 As shown, it includes the following: S1. Load conductive ink into dispensing syringe 17, select a dispensing needle of appropriate specification according to the design of direct writing conductive circuit, fix dispensing syringe 17 on the end clamp of six-axis robotic arm 9, and check whether the air circuit connection between dispensing syringe 17, pneumatic dispensing machine 12 and external air pump is complete. Conductive inks can be selected from conductive silver inks, conductive copper inks, conductive carbon pastes, etc., with conductive silver inks being preferred. The viscosity characteristics of the inks preferably satisfy the requirement that the viscosity value is higher than 10 Pa·s when the shear rate is 1 s⁻¹.

[0029] S2. Install the micro-device strip 3 on the first traction wheel 2 and the second traction wheel 7, and support it through the transmission wheel group 4. Tear open the sealing bag on the surface of the micro-device strip 3 and fix it on the sealing bag traction wheel 5. S3. Place and fix the workpiece 18 on the heating pad 15 of the three-axis motion platform 16. Adjust the needle tip position and coordinates of the dispensing syringe 17 using the six-axis robotic arm 9, positioning it above the starting point of the direct writing line on the workpiece surface and maintaining a suitable dispensing height. Set the motion program and direct writing speed of the dispensing syringe 17, and test run it according to the set direct writing path to check whether there is any motion interference between the workpiece 18 and the mechanical tooling during the entire direct writing process. If there are no problems, proceed to the next step; otherwise, readjust and set. S4. Turn on the exhaust device 8, set the dispensing process program and the corresponding extrusion pressure, and after adjusting the dispensing syringe 17 to the starting position by the six-axis robotic arm 9, a uniform and complete conductive ink line 19 is formed on the surface of the workpiece. The preferred dispensing process is pneumatic extrusion dispensing. The main process parameters include extrusion pressure, direct writing speed, and dispensing height. The preferred extrusion pressure is 10-60 Psi, the preferred direct writing speed is 1-20 mm / s, and the preferred dispensing height is 100-200 μm. For direct writing, a needle size of 27 G-34 G is preferred to meet the direct writing requirements of circuits of different sizes.

[0030] S5. Replace the dispensing syringe 17 at the end of the six-axis robotic arm 9 with a gripping claw 21. The gripping claw 21 transfers the micro-device 23 according to the set motion program and fixes it to the designated placement position of the workpiece. During gripping, the air pressure in the air pressure pipe 20 is adjusted to be lower than the negative pressure state to maintain the suction state of the micro-device 23. After transfer and placement, the air pressure in the central air pipe 20 is adjusted to form a clamping force on the device. At the same time, the hot air blown out by the hot air pipe 22 on the outside of the gripping device initially achieves the pre-sintering of the micro-device 23 and the conductive ink line 19, achieving the purpose of preliminary curing. The preferred hot air temperature is 100-150 ℃.

[0031] S6. Adjust the temperature of the heating pad 15 and set the heating time to sinter the conductive ink line 19 into a conductive line 24; simultaneously, the micro-device 23 and the conductive ink line 19 are further sintered to enhance the connection between the conductive line and the micro-device. At this point, the direct-write fabrication of the curved circuit and the surface mount connection of the micro-device are completed, thus completing the fabrication of the curved circuit.

[0032] The preferred workpiece heating temperature is 200-300 ℃, and the preferred heating time is 20-40 min.

[0033] Example 1 Conductive silver ink was selected as the direct-write ink and placed in the dispensing syringe. The viscosity of the conductive silver ink was 12 Pa·s (shear rate of 1 s⁻¹). A 34G dispensing needle with an inner diameter of approximately 60 μm was selected. The air circuit connection and external pressure were checked. Fix the planar workpiece on a 3-axis motion platform, adjust the position of the dispensing needle so that it is about 100 μm above the workpiece surface, set the robot arm motion program and the dispensing machine working program, set the direct writing speed to 1 mm / s and the extrusion pressure to 10 Psi.

[0034] After the aforementioned preparatory work is completed, both the dispensing machine and the robotic arm are activated simultaneously to complete the drawing of the conductive ink circuit, such as... Figure 3 The scanning electron microscope image shows the linewidth characteristics of the direct-write pattern, achieving a linewidth accuracy of 90 μm.

[0035] Set the heating pad temperature to 300 ℃ and the heating time to 30 min. Turn on the exhaust device and wait for the direct-write circuit to sinter and form.

[0036] Using the four-probe method, the conductivity of the directly written conductive silver layer was measured and statistically analyzed to reach 8.4 × 10⁶ S / m. Figure 4 As shown.

[0037] Example 2 Conductive silver ink was selected as a direct-write ink and placed in a dispensing syringe. The viscosity of the conductive silver ink was 20 Pa·s (shear rate of 1 s⁻¹). A 32G dispensing needle with an inner diameter of approximately 110 μm was selected. The air circuit connection and external pressure were checked.

[0038] Fix the frustum-shaped workpiece on a 3-axis motion platform, adjust the position of the dispensing needle so that its height from the surface of the workpiece at the starting point of direct writing is about 100 μm, set the robot arm motion program and the dispensing machine working program, set the direct writing speed to 15 mm / s and the extrusion pressure to 30 Psi.

[0039] Once the aforementioned preparations are completed, both the dispensing machine and the robotic arm are activated simultaneously to complete the drawing of the conductive ink circuit.

[0040] Set the heating pad temperature to 200 ℃ and the heating time to 40 min. Turn on the exhaust device and wait for the direct-write circuitry to sinter and form. Figure 5 It is a blocky conductive pattern on the side surface of a frustum-shaped workpiece.

[0041] Example 3 Conductive silver ink was selected as a direct-write ink and placed in a dispensing syringe. The viscosity of the conductive silver ink was 12 Pa·s (shear rate of 1 s⁻¹). A 27G dispensing needle with an inner diameter of approximately 210 μm was selected. The air circuit connection and external pressure were checked.

[0042] Fix the concave spherical workpiece on a 3-axis motion platform, adjust the position of the dispensing needle so that its height from the surface of the workpiece at the starting point of direct writing is about 100 μm, set the robot arm motion program and the dispensing machine working program, set the direct writing speed to 15 mm / s and the extrusion pressure to 30 Psi.

[0043] Select LED surface mount devices with a 0805 package size and place them in the device transport platform.

[0044] Once the aforementioned preparations are completed, both the dispensing machine and the robotic arm are activated simultaneously to complete the drawing of the conductive ink circuit.

[0045] Replace with a micro-device clamping device, turn on the fume extraction device, set the robotic arm motion program and the clamping device's motion commands, and place it close to the central air duct. Set the air pressure in the central air duct of the placement nozzle to 0.8 atmospheres to further pick up the placement device and transfer it to the workpiece surface to be placed. Turn on the hot air duct outside the clamping device, set the blown hot air temperature to 150℃, wait for about 1 minute, adjust the air pressure in the central air duct to 1-2 MPa to form a clamping force on the placement device, wait for about 2 minutes, release the clamping jaws, and complete the initial curing connection of the placement device to the circuit.

[0046] Set the heating pad temperature to 200℃ and the heating time to 40 minutes, then wait for the direct-write circuitry to sinter and form. Figure 6 This is a sample drawing of the part produced in this embodiment.

[0047] Taking a conical substrate with a bottom diameter of approximately φ500mm and a height of approximately 500mm as an example, the time required to complete the fabrication of wires and the mounting of 100 devices using traditional manufacturing methods is as follows: 1 day for surface metallization coating + 1 day for laser etching (including transport and clamping time) + solder dotting for device mounting + placement + thermoforming, averaging 1 minute per device, for a total time of approximately 1.6 hours and approximately 2.5 days. The time required to fabricate curved circuits using this method is: 5 hours for direct circuit writing + 4 hours for placement and pre-sintering + 1 hour for overall sintering, for a total time of approximately 0.5 days. The method of this invention reduces the time to 1 / 5 compared to the traditional method. Since the surface coating and etching processes are eliminated, the cost will also be significantly reduced.

Claims

1. A curved surface circuit processing device, characterized in that: The device is housed in a closed enclosure and includes a component conveying device, a fume extraction device (8), a six-axis robotic arm (9), a pneumatic dispensing machine (12), and a three-axis motion platform (16). The three-axis motion platform (16) has a heating pad (15) on which a workpiece (18) is placed. The pneumatic dispensing machine (12) and the dispensing syringe (17) form a direct writing device. The six-axis robotic arm (9) clamps the dispensing syringe (17) and squeezes conductive ink onto the surface of the workpiece (18) to form conductive ink lines (19). The six-axis robotic arm (9) then moves the clamping jaws (21) to... The clamping claw (21) has a pneumatic pipe (20) in the middle and hot air pipes (22) on both sides. When the clamping claw (21) grasps the micro device (23), the pneumatic pipe (20) provides suction force with negative pressure. When the clamping claw (21) fixes the micro device (23) on the conductive ink line (19), the pneumatic pipe (20) provides pressure with positive pressure. After the micro device (23) is mounted by the hot air pipe (22), it is pre-sintered and then cured as a whole by the heating pad (15). The conductive ink line (19) forms a conductive line (24).

2. The curved surface circuit processing apparatus according to claim 1, characterized in that: The device conveying device includes a first traction wheel (2), a conveying wheel group (4), a sealing film traction wheel (5), and a second traction wheel (7). The micro-device strip (3) is mounted on the first traction wheel (2) and the second traction wheel (7) and supported by the conveying wheel group (4). The sealing bag on the surface of the micro-device strip (3) is torn open and fixed on the sealing bag traction wheel (5).

3. The curved surface circuit processing apparatus according to claim 1, characterized in that: The pneumatic dispensing machine (12) is pressurized by an external air pump connected through the air circuit interface (11).

4. The curved surface circuit processing apparatus according to claim 1, characterized in that: The gripper (21) adopts a gripping scheme that combines mechanical gripping and vacuum adsorption.

5. The curved surface circuit processing apparatus according to claim 1, characterized in that: The enclosed enclosure has a base (1), and also includes a monitoring system (6), an interactive panel (13), and a control cabinet (14). The monitoring system (6) is used to observe the processing in real time.

6. The curved surface circuit processing apparatus according to claim 1, characterized in that: The conductive ink is selected from conductive silver ink, conductive copper ink, or conductive carbon paste.

7. A method for fabricating curved circuits, using the curved circuit fabrication apparatus as described in any one of claims 1-6, characterized in that, The method includes the following steps: S1. Prepare the direct writing device; S2. Mount the micro-device strip (3) onto the device transport device; S3. Place the workpiece (18) on the heating pad (15) of the three-axis motion platform (16) and fix it. Adjust the needle tip position and coordinate of the dispensing syringe (17) through the six-axis robotic arm (9), set the motion program and direct writing speed of the dispensing syringe (17) and run it for trial until there is no motion interference. S4. Open the exhaust device (8), set the dispensing process and extrusion pressure, and use the six-axis robotic arm (9) to drive the dispensing syringe (17) to form conductive ink lines (19) on the workpiece surface. S5. Replace the dispensing syringe (17) at the end of the six-axis robotic arm (9) with a gripper (21), and transfer the micro-device (23) through the gripper (21) and pre-sinter it to the designated patch position of the workpiece. S6. Adjust the temperature of the heating pad (15) and set the heating time so that the conductive ink line (19) is sintered into a conductive line (24), and the micro device (23) and the conductive ink line (19) are sintered synchronously.

8. The method for fabricating curved circuits according to claim 7, characterized in that: In S1, conductive ink is loaded into the dispensing syringe (17). According to the design of the direct-write conductive circuit, a suitable dispensing needle is selected. The dispensing syringe (17) is fixed at the end of the six-axis robotic arm (9). Check whether the air circuit connection between the dispensing syringe (17), the pneumatic dispensing machine (12), and the external air pump is complete.

9. The method for fabricating curved circuits according to claim 7, characterized in that: In S2, the microdevice strip (3) is installed on the first traction wheel (2) and the second traction wheel (7), and supported by the transmission wheel group (4). The sealing bag on the surface of the microdevice strip (3) is torn open and fixed on the sealing bag traction wheel (5).

10. The method for fabricating curved circuits according to claim 7, characterized in that: In S5, the micro-device (23) is clamped by the clamping claw (21), and the micro-device (23) is sucked up by adjusting the air pressure in the air pressure pipe (20) to a negative pressure state. After the transfer and mounting, the air pressure in the central air path pipe (20) is adjusted to a positive pressure state to press the micro-device (23). The hot air blown out by the hot air pipe (22) initially realizes the pre-sintering of the micro-device (23) and the conductive ink circuit (19).

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