Rigid-flex circuit board processing device and rigid-flex combined board windowing manufacturing method

Abstract

The application discloses a rigid-flex circuit board processing device and a rigid-flex combined board windowing manufacturing method. The rigid-flex circuit board processing device comprises: a machine table capable of fixing a circuit board, the circuit board having a flexible area with a protective film fixed on the surface; a depth control unit connected to the machine table, comprising a driving member, a processing spindle and an ultrasonic transducer, the processing spindle having a working state, the driving member being used for driving the processing spindle in the working state to move in the flexible area and controlling the feeding depth of the processing spindle on the flexible area; when the ultrasonic transducer is in a first working mode, the processing spindle in the working state is used for cutting the flexible area, and the ultrasonic transducer can drive the processing spindle to vibrate within an amplitude of less than or equal to 15 microns along the feeding direction of the processing spindle. The integrated ultrasonic vibration auxiliary cutting realizes high-quality depth control processing of the flexible area of the rigid-flex circuit board, suppresses the tearing, burr and delamination defects of the polyimide film, and significantly improves the processing consistency and product yield.

Description

Technical Field

[0001] This invention relates to the field of circuit board manufacturing technology, and in particular to a rigid-flex circuit board processing apparatus, and a method for creating a window in a rigid-flex bonded board applied to the rigid-flex circuit board processing apparatus. Background Technology

[0002] Rigid-flex circuit boards are widely used in aerospace, medical electronics, and consumer electronics fields because they combine the mechanical support of rigid boards with the spatial bending capability of flexible boards.

[0003] During the manufacturing process, the surface of the flexible area is covered with a polyimide film to protect the copper circuitry and provide insulation and bending resistance. The flexible area covered with the polyimide film and other flexible materials needs to be milled in depth to create windows such as solder pads and gold fingers.

[0004] However, in the mechanical control and deep processing of such composite materials with alternating soft and hard phases, flexible materials such as polyimide films have high toughness and low strength. Traditional continuous cutting can easily cause material tearing, burrs, and separation between the polyimide film and the circuit board. Furthermore, the polyimide film and its intermediate adhesive layer are prone to adhering to the cutting edge of the cutting head during the cutting process, forming built-up edge, which aggravates the wear of the cutting head and deteriorates the processing quality, seriously affecting the product yield and reliability. Summary of the Invention

[0005] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a rigid-flex circuit board processing device that integrates ultrasonic vibration-assisted cutting, a densely distributed micro-storage groove structure on the cutter head surface, and closed-loop adaptive control. This achieves high-quality, controlled-depth processing of the flexible region of rigid-flex circuit boards. During processing, it can synergistically utilize chip storage and friction reduction effects with high-frequency intermittent cutting, effectively suppressing polyimide film tearing, burrs, and delamination defects, and significantly improving processing consistency, cutter head life, and product yield.

[0006] The present invention also proposes a method for fabricating a window in a rigid-flex circuit board applied to the above-mentioned rigid-flex circuit board processing apparatus.

[0007] The rigid-flex circuit board processing apparatus according to the present invention includes: The machine is capable of fixing a circuit board, the circuit board having a flexible area, and a protective film is fixed to the surface of the flexible area; A depth control unit is connected to the machine tool. The depth control unit includes a drive unit, a machining spindle, and an ultrasonic transducer. The machining spindle has a working state. The drive unit is used to drive the machining spindle in the working state to move in the flexible region and control the feed depth of the machining spindle in the flexible region. The ultrasonic transducer is connected to the machining spindle and has a first working mode. When the ultrasonic transducer is in the first working mode, the machining spindle in the working state performs cutting machining on the flexible area. Along the feed direction of the machining spindle, the ultrasonic transducer can drive the machining spindle to vibrate within an amplitude of less than or equal to 15 micrometers.

[0008] The rigid-flex circuit board processing apparatus according to the present invention has at least the following beneficial effects: By integrating the ultrasonic transducer into the processing spindle of the depth control unit, when the ultrasonic transducer is in the first working mode, the ultrasonic transducer can apply a high-frequency micro-amplitude vibration of less than or equal to 15 micrometers to the processing spindle in the working state along the feed direction of the processing spindle, so that a high-frequency intermittent cutting effect is formed between the cutting head and the protective film of the flexible area, dividing the continuous cutting process into instantaneous impact separation action, significantly reducing the peak cutting force per unit time, and avoiding the tearing of the protective film and burrs caused by continuous stretching. This technology addresses defects such as interlayer separation between the flexible and non-flexible regions, improving the machining quality and product yield of controlled-depth milling grooves. Specifically, the amplitude controlled within 15 micrometers along the feed direction allows vibration energy to act directly on the cutting direction, ensuring cutting efficiency while avoiding impact damage to the extremely thin remaining flexible region, thus ensuring safe and stable machining of the fragile transition area. Furthermore, the first operating mode allows the ultrasonic transducer to be activated only when machining the flexible region, and can be turned off or put into standby mode when not machining or machining the rigid region of the circuit board, meeting the differentiated machining needs of the flexible and rigid regions of the circuit board.

[0009] According to some embodiments of the present invention, the rigid-flex circuit board processing apparatus further includes a current detector and an acceleration detector. The current detector is used to detect the operating current value of the processing spindle, and the acceleration detector is used to detect the vibration acceleration value of the processing spindle. The ultrasonic transducer is configured to adjust vibration parameters based on the operating current value and the vibration acceleration value.

[0010] According to some embodiments of the present invention, the vibration parameters of the rigid-flex circuit board processing apparatus include vibration frequency, vibration amplitude and vibration mode, wherein the vibration frequency is 20KHz to 40KHz, the vibration amplitude is 3μm to 8μm and the vibration mode is a pulse modulation mode.

[0011] According to some embodiments of the present invention, the rigid-flex circuit board processing apparatus includes a processing spindle comprising a cutting head having a plurality of spaced-apart storage slots configured to store lubricating oil and / or debris generated during cutting by the cutting head.

[0012] According to some embodiments of the rigid-flex circuit board processing apparatus of the present invention, the storage tank is hemispherical, the diameter of the storage tank is 5μm to 10μm, and the maximum depth of the storage tank is less than or equal to 5μm.

[0013] According to some embodiments of the present invention, in the rigid-flex circuit board processing apparatus, the surface of the cutting head has a nanocomposite coating, and the storage groove is arranged in the nanocomposite coating.

[0014] According to some embodiments of the present invention, the rigid-flex circuit board processing apparatus includes an oil reservoir connected to the machine base, an ultrasonic transducer having a second working mode, and a processing spindle having a clean state. The drive unit can drive the tool head of the machining spindle, which is in a clean state, to be placed in the oil reservoir. The ultrasonic transducer, which is in the second working mode, operates at full power to drive the machining spindle to vibrate and clean the tool head.

[0015] According to some embodiments of the present invention, the rigid-flex circuit board processing apparatus includes a temperature detection sensor for detecting the temperature of the surface of the machine tool in contact with the circuit board. The machine tool has a liquid cooling channel that allows liquid to flow. The flow rate of the liquid increases or decreases based on the detection value of the temperature detection sensor to drive the temperature of the machine tool surface to be maintained within a preset range.

[0016] The method for fabricating a window in a rigid-flex PCB according to the present invention is applied to the rigid-flex circuit board processing apparatus of the present invention; the method for fabricating a window in a rigid-flex PCB includes the following steps: Feeding: The circuit board is fixed to the surface of the machine tool, and the protective film of the flexible area is arranged facing the side of the processing spindle; Window opening processing: After loading, before the drive component drives the processing spindle to move to the preset position of the flexible area, or after the drive component drives the processing spindle to move to the preset position of the flexible area, the ultrasonic transducer enters the first working mode, and the drive component and the processing spindle cooperate to perform window opening processing on the flexible area.

[0017] The method for manufacturing a rigid-flexible bonded board with a window according to the present invention has at least the following beneficial effects: by fixing the circuit board to the machine surface and facing the machining spindle in the feeding step, the ultrasonic transducer can enter the first working mode before or after the driving component drives the machining spindle to a preset position in the windowing machining step, providing a flexible choice for the timing of ultrasonic vibration intervention. Thus, the cutting head can be excited with high-frequency micro-vibration before contacting the workpiece, avoiding the initial damage to the flexible protective film such as polyimide film caused by the impact load during the start of conventional cutting, and realizing high-quality, low-damage windowing of the polyimide film protective film in the flexible transition zone.

[0018] According to the method for manufacturing a rigid-flex PCB with a window according to the present invention, the rigid-flex PCB processing device includes a temperature detection sensor, which is used to detect the temperature of the surface of the machine tool in contact with the PCB, and the machine tool has a liquid cooling channel that can supply liquid flow. The machine is connected to an oil storage box, and the ultrasonic transducer has a second working mode. The method for manufacturing a window in a rigid-flexible composite plate also includes the following steps: Temperature control: Before the window is opened for processing, the liquid is circulated into the liquid cooling channel at a preset speed; During the window opening process, when the temperature detection sensor detects that the temperature of the machine surface is greater than 45°C, the operating power of the liquid pump is increased to increase the speed at which the liquid passes through the liquid cooling channel. When the temperature sensor detects that the temperature rise on the surface of the machine is greater than 0.5℃ / min, the cooler cools the liquid to reduce the temperature of the liquid passing through the liquid cooling channel; When the temperature sensor detects that the temperature of the machine surface is less than 35°C, the liquid is circulated into the liquid cooling channel at a preset speed. Spindle cleaning: Before and after window opening, the drive unit drives the cutting head of the machining spindle to move into the oil reservoir. The ultrasonic transducer enters the second working mode and operates at full power to drive the machining spindle to vibrate and clean the cutting head.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the rigid-flex circuit board processing device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the circuit board to be processed by the rigid-flex circuit board processing device according to an embodiment of the present invention; Figure 3 This is an enlarged schematic diagram of the cutting head of the machining spindle of the rigid-flex circuit board machining apparatus according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the control of the rigid-flex circuit board processing device according to an embodiment of the present invention; Figure 5 This is a flowchart of a method for fabricating a window in a rigid-flex circuit board using a rigid-flex circuit board processing apparatus according to an embodiment of the present invention.

[0021] Explanation of icon numbers: Machine 100; Liquid cooling aisle 101; Circuit board 200; Flexible area 210; Protective film 211; Depth control unit 300; drive unit 310; machining spindle 320; tool head 3201; storage tank 32011; current detector 321; acceleration detector 322; ultrasonic transducer 330; Oil reservoir 400. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0023] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0024] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0025] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0026] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0027] Therefore, such as Figures 1 to 4 As shown, the rigid-flex PCB processing apparatus proposed in this invention includes a machine base 100 capable of fixing a PCB 200 and a depth control unit 300 connected to the machine base 100 for router processing of the PCB 200. The PCB 200 has a flexible region 210, and a protective film 211 is fixed to the surface of the flexible region 210. A common protective film 211 is a polyimide film. Specifically, the depth control unit 300 includes a drive unit 310, a processing spindle 320, and an ultrasonic transducer 330. The processing spindle 320 has a working state of rotating a cutting head 3201. The drive unit 310 is used to drive the processing spindle 320 in the working state to move within the flexible region 210 and control the feed depth of the processing spindle 320 into the flexible region 210. Understandably, the machine tool 100 fixes the circuit board 200 by vacuum adsorption or adhesive fixation, and then identifies the processing position of the circuit board 200 through preset positioning holes or by additional visual recognition. Common methods for fixing the circuit board 200 during processing can be referenced, and will not be elaborated further here. Additionally, the drive unit 310 can be a common three-axis robot consisting of three linear modules, capable of driving the processing spindle 320 to move in the X, Y, and Z axes; this will not be elaborated further here.

[0028] Furthermore, the ultrasonic transducer 330 is connected to the machining spindle 320. The ultrasonic transducer 330 has a first working mode. When the ultrasonic transducer 330 is in the first working mode, the machining spindle 320 in the working state cuts the flexible region 210. Along the feed direction of the machining spindle 320, the ultrasonic transducer 330 can drive the machining spindle 320 to vibrate within an amplitude of less than or equal to 15 micrometers.

[0029] It should be noted that by integrating the ultrasonic transducer 330 into the machining spindle 320 of the depth control unit 300, when the ultrasonic transducer 330 is in the first working mode, the ultrasonic transducer 330 can apply a high-frequency micro-amplitude vibration of less than or equal to 15 micrometers to the machining spindle 320 in the feed direction of the machining spindle 320, so that a high-frequency intermittent cutting effect is formed between the tool tip 3201 and the protective film 211 of the flexible area 210, dividing the continuous cutting process into instantaneous impact separation actions, significantly reducing the peak cutting force per unit time, and avoiding tearing of the protective film 211, burrs, and contact with the flexible area caused by continuous stretching. Defects such as interlayer separation between 210 layers are eliminated, improving the machining quality and product yield of the controlled depth milling groove. Among them, the amplitude controlled within 15 micrometers along the feed direction allows the vibration energy to act directly on the cutting direction, ensuring cutting efficiency while avoiding impact damage to the remaining thin flexible area 210, ensuring safe and stable machining of the fragile transition area. In addition, the setting of the first working mode allows the ultrasonic transducer 330 to be activated only when machining the flexible area 210, and can be turned off or put into standby when not machining or machining the rigid area of ​​the circuit board 200, realizing the differentiated machining needs of the flexible area 210 and the rigid area of ​​the circuit board 200.

[0030] Refer to Figure 4 In some embodiments of the present invention, the rigid-flex circuit board processing apparatus includes a current detector 321 and an acceleration detector 322. The current detector 321 detects the operating current value of the processing spindle 320, and the acceleration detector 322 detects the vibration acceleration value of the processing spindle 320. The ultrasonic transducer 330 is configured to adjust vibration parameters based on the operating current value and the vibration acceleration value. It is understood that in the controlled-depth windowing processing of rigid-flex boards, the cutter head 3201 needs to repeatedly traverse the boundary between the rigid region and the flexible region 210. The polyimide film in the flexible region 210 has high toughness and low strength, and traditional continuous cutting easily causes material tearing, burrs, and interlayer separation.

[0031] In response, the current detector 321 can sense changes in the drive current of the machining spindle 320 in real time, thus sensitively reflecting the dynamic fluctuations of the cutting load. It is understandable that when the tool tip 3201 moves from the rigid zone to the flexible transition zone, the abrupt change in material properties will cause a significant change in current. Meanwhile, the acceleration detector 322 directly monitors the vibration acceleration of the machining spindle 320, providing accurate feedback on the actual output effect of the ultrasonic transducer vibration.

[0032] Accordingly, the ultrasonic transducer 330 automatically adjusts the vibration parameters based on the comprehensive judgment of the two detection signals, enabling the device to adapt to changes in cutting conditions. This overcomes the defect of traditional open-loop control depth milling processes, which are prone to overcutting or damaging internal circuits when entering the flexible zone 210 due to the inability to sense load changes in real time.

[0033] Optionally, vibration parameters include vibration frequency, vibration amplitude, and vibration mode. In some machining applications, the vibration frequency is 20kHz to 40kHz, which can effectively excite a high-frequency intermittent cutting effect, causing high-frequency periodic separation between the tool tip 3201 and the polyimide film, breaking the macroscopic continuous chips into microscopic fragments. For the fragile transition zone with a remaining thickness of less than 0.2mm, in some machining applications, the vibration amplitude is 3μm to 8μm, providing sufficient impact energy to break the chips while avoiding impact damage to the extremely thin flexible layer due to excessive amplitude. The vibration mode is a pulse modulation mode, which achieves intermittent vibration output by adjusting the duty cycle, further optimizing the time distribution of cutting force and reducing cutting heat accumulation and temperature rise of the tool tip 3201. Through the synergistic effect of these three factors, the peak cutting force is significantly reduced, significantly suppressing tearing, burr, and delamination defects of the polyimide film, while improving machining stability and the service life of the tool tip 3201.

[0034] In controlled-depth milling of rigid-flexible plates, the polyimide film and its intermediate bonding layer tend to adhere to the cutting edge of the tool tip 3201 during cutting, forming built-up edge, which exacerbates tool tip 3201 wear and deteriorates machining quality. (Refer to...) Figure 3 In some embodiments of the present invention, the cutting head 3201 has a plurality of spaced storage grooves 32011, which are configured to store lubricating oil and chips during cutting by the cutting head 3201, so that the cutting head 3201 has self-lubricating and self-cleaning functions.

[0035] Understandably, the storage groove 32011, acting as a miniature oil reservoir, carries and gradually releases lubricating oil, forming a lubricating film between the cutting head 3201 and the workpiece to be cut. This effectively reduces the coefficient of friction and cutting force. Simultaneously, after the chips from high-frequency intermittent cutting are broken up, the storage groove 32011 captures and promptly collects them, preventing chip buildup at the cutting edge. By reducing friction and optimizing chip removal, adhesion and cold welding between the cutting head 3201 and the workpiece are reduced. This helps suppress tearing defects in the polyimide film caused by adhesion and stretching, and effectively extends the service life of the cutting head 3201. Understandably, the storage groove 32011 of the cutting head 3201 is designed for optimized cutting of the flexible region 210 and can be combined with conventional milling settings. Corresponding lubricant nozzles and chip removal nozzles can be installed on the outer periphery of the machining spindle 320; details will not be elaborated here.

[0036] Optionally, refer to Figure 3The storage groove 32011 is hemispherical, with a diameter of 5μm to 10μm and a maximum depth of less than or equal to 5μm, designed as a micro-nano textured structure. It is easy to understand that the hemispherical structure, compared to shapes such as squares or cones, is more conducive to the uniform storage and slow release of lubricating oil. Furthermore, the rounded bottom edge is less prone to stress concentration, avoiding problems such as coating peeling or micro-cracks in the substrate caused by stress concentration at the microstructure edge during cutting. The optimized combination of a diameter of 5μm to 10μm and a depth of less than or equal to 5μm ensures that a sufficient number of oil and chip storage points can be formed within a limited cutting edge area, without affecting the structural strength of the cutting edge 3201 substrate or the sharpness of the cutting edge.

[0037] In some manufacturing applications, the surface of the cutting tip 3201 has a nanocomposite coating, and the storage groove 32011 is arranged on the nanocomposite coating, realizing the organic integration of hard coating and micro / nano texture. It should be noted that the nanocomposite coating, such as diamond-like carbon or titanium nitride-based coating, endows the surface of the cutting tip 3201 with high hardness, low coefficient of friction and good chemical stability, providing basic wear-resistant protection and friction reduction functions, while the storage groove 32011 can be constructed with periodic micro / nano structures on this coating through femtosecond laser etching technology.

[0038] Understandably, the nanocomposite coating on the cutting tool 3201 significantly improves its performance in high-speed cutting, achieving a hardness of up to 45 GPa, reducing the coefficient of friction by 30%, increasing its lifespan by 3 to 5 times, and lowering the cutting temperature by 250°C. The coating itself reduces the adhesion tendency to the chip contact surface. Furthermore, the arrangement of micro-nano structured storage grooves 32011 allows the cutting tool 3201 to maintain good sharpness and stable cutting performance for extended periods when cutting flexible materials such as polyimide films, while simultaneously reducing the need for frequent tool changes due to coating peeling or tool dulling.

[0039] Refer to Figure 1 In some embodiments of the present invention, the machine tool 100 is connected to an oil reservoir 400, wherein the ultrasonic transducer 330 has a second operating mode, and the machining spindle 320 is in a clean state. In application, the drive unit 310 can drive the cutter head 3201 of the machining spindle 320 in the clean state to be placed in the oil reservoir 400. The ultrasonic transducer 330 in the second operating mode operates at full power to drive the machining spindle 320 to vibrate and clean the cutter head 3201, further giving the cutter head 3201 an automatic cleaning function.

[0040] By utilizing the cavitation effect of ultrasound in liquids, the high-pressure micro-jet and localized high temperature generated by the instantaneous collapse of cavitation bubbles near the surface of the cutting head 3201 effectively remove cutting residues, built-up edge, and lubricating grease adhering to the cutting edge of the cutting head 3201 and the storage groove 32011, achieving efficient online cleaning of the cutting head 3201. Combined with the aforementioned micro-nano structured storage groove 32011, a complete cleaning cycle is formed. During machining, the storage groove 32011 stores oil to reduce friction and collects debris; after machining, it is restored to a clean state through ultrasonic cavitation cleaning. This allows the cutting head 3201 to be reused in optimal condition for the next machining operation, avoiding the degradation of machining quality caused by contamination of the cutting head 3201. It also eliminates the need for manual disassembly and cleaning, reducing downtime losses and improving the automation level and continuous operation capability of the equipment.

[0041] In addition, the manufacturing of rigid-flex plates requires extremely high precision. The interlayer alignment tolerance between the rigid and flexible regions 210 of the rigid-flex plate needs to be controlled within ±25μm, and any deformation caused by temperature will directly affect the processing accuracy.

[0042] In this regard, refer to Figure 1 In some embodiments of the present invention, the rigid-flex circuit board processing apparatus includes a temperature detection sensor. Specifically, the temperature detection sensor is used to detect the temperature of the surface of the machine tool 100 in contact with the circuit board 200. Matching this, the machine tool 100 has a liquid cooling channel 101, which allows liquid flow. The liquid flow rate increases or decreases based on the detected value of the temperature detection sensor, thereby maintaining the surface temperature of the machine tool 100 within a preset range. This closed-loop temperature control mechanism effectively suppresses thermal deformation of the machine tool 100 caused by accumulated cutting heat or fluctuations in ambient temperature, ensuring the positioning accuracy and flatness of the circuit board 200 during processing. This provides stable conditions for long-term continuous processing and the production of high-precision rigid-flex boards that are sensitive to temperature, thereby improving the consistency of depth control cutting and the yield of finished products.

[0043] Refer to Figure 5 The method for fabricating a window in a rigid-flex PCB according to an embodiment of the present invention is applied to a rigid-flex circuit board processing apparatus according to an embodiment of the present invention, wherein the method for fabricating a window in a rigid-flex PCB includes the following steps: S100, Loading: The circuit board 200 is fixed on the surface of the machine tool 100, and the protective film 211 of the flexible area 210 is arranged facing the side of the machining spindle 320. S200, Window opening processing: After loading S100, before the drive unit 310 drives the processing spindle 320 to move to the preset position of the flexible area 210, or after the drive unit 310 drives the processing spindle 320 to move to the preset position of the flexible area 210, the ultrasonic transducer 330 enters the first working mode, and the drive unit 310 and the processing spindle 320 cooperate to perform window opening processing on the flexible area 210.

[0044] In the loading step S100, the circuit board 200 is fixed to the surface of the machine tool 100 and the protective film 211 is facing the machining spindle 320. In the window opening machining step S200, the ultrasonic transducer 330 can enter the first working mode before or after the driving component 310 drives the machining spindle 320 to move to the preset position. This provides a flexible choice for the timing of ultrasonic vibration intervention, so that the cutter head 3201 can be excited to generate high-frequency micro-vibration before contacting the workpiece. This avoids the initial damage to the flexible protective film 211 such as polyimide film caused by the impact load during the start of conventional cutting. This achieves high-quality, low-damage window opening of the polyimide film protective film 211 in the flexible transition area.

[0045] Furthermore, The method for fabricating windows in rigid-flexible composite panels also includes the following steps: S201, Temperature Control: Before the S200 is processed by opening the window, the liquid is circulated into the liquid cooling channel 101 at a preset speed; In the window opening process S200, when the temperature detection sensor detects that the temperature on the surface of the machine tool 100 is greater than 45°C, the operating power of the liquid pump is increased to increase the speed at which the liquid passes through the liquid cooling channel 101. When the temperature sensor detects that the temperature rise on the surface of the machine tool 100 is greater than 0.5℃ / min, the cooler cools the liquid to reduce the temperature of the liquid passing through the liquid cooling channel 101. When the temperature sensor detects that the surface temperature of the machine 100 is less than 35°C, the liquid is circulated into the liquid cooling channel 101 at a preset speed. S300 Spindle Cleaning: Before and after window opening S200, the drive unit 310 drives the cutting head 3201 of the machining spindle 320 to move into the oil reservoir 400. The ultrasonic transducer 330 enters the second working mode. The ultrasonic transducer 330 moves at full power to drive the machining spindle 320 to vibrate and clean the cutting head 3201.

[0046] To address this, before the S200 window-opening process, the liquid is circulated into the liquid cooling channel 101 at a preset speed to bring the machine tool 100 to thermal equilibrium. During the S200 window-opening process, graded control is implemented based on feedback from the temperature detection sensor. When the temperature is greater than 45°C, the power of the liquid pump is increased to improve the flow rate and enhance heat dissipation. When the temperature rise rate is greater than 0.5°C / min, the cooler is activated to actively cool the liquid. When the temperature is less than 35°C, the preset flow rate is restored to maintain stability. This graded and segmented control strategy ensures the precise stability of the surface temperature of the machine tool 100 and suppresses the impact of thermal deformation on machining accuracy.

[0047] In addition, the spindle cleaning S300 step is performed before and after the window opening process S200, so that the cutter head 3201 is cleaned by ultrasonic vibration in the oil reservoir 400, ensuring that each window opening is performed with the cutter head 3201 in a sharp state. By organically integrating active temperature control with the automatic cleaning function of the 3201 cutter head into standardized operating procedures, batch-to-batch quality fluctuations caused by thermal deformation or contamination of the 3201 cutter head are effectively reduced, improving the yield and consistency of mass production.

[0048] Other configurations and operations of the rigid-flexible plate window manufacturing method according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0049] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A rigid-flex circuit board processing device, characterized in that, include: The machine is capable of fixing a circuit board, the circuit board having a flexible area, and a protective film is fixed to the surface of the flexible area; A depth control unit is connected to the machine tool. The depth control unit includes a drive unit, a machining spindle, and an ultrasonic transducer. The machining spindle has a working state. The drive unit is used to drive the machining spindle in the working state to move in the flexible region and control the feed depth of the machining spindle in the flexible region. The ultrasonic transducer is connected to the machining spindle and has a first working mode. When the ultrasonic transducer is in the first working mode, the machining spindle in the working state performs cutting machining on the flexible area. Along the feed direction of the machining spindle, the ultrasonic transducer can drive the machining spindle to vibrate within an amplitude of less than or equal to 15 micrometers.

2. The rigid-flex circuit board processing apparatus according to claim 1, characterized in that: The rigid-flex circuit board processing device further includes a current detector and an acceleration detector. The current detector is used to detect the operating current value of the processing spindle, and the acceleration detector is used to detect the vibration acceleration value of the processing spindle. The ultrasonic transducer is configured to adjust vibration parameters based on the operating current value and the vibration acceleration value.

3. The rigid-flex circuit board processing apparatus according to claim 2, characterized in that: The vibration parameters include vibration frequency, vibration amplitude, and vibration mode. The vibration frequency is 20KHz to 40KHz, the vibration amplitude is 3μm to 8μm, and the vibration mode is a pulse modulation mode.

4. The rigid-flex circuit board processing apparatus according to claim 1, characterized in that: The machining spindle includes a cutting head having a plurality of spaced-apart storage slots configured to store lubricating oil and / or chips generated during cutting by the cutting head.

5. The rigid-flex circuit board processing apparatus according to claim 4, characterized in that: The storage tank is hemispherical, with a diameter of 5μm to 10μm and a maximum depth of 5μm or less.

6. The rigid-flex circuit board processing apparatus according to claim 4, characterized in that: The surface of the blade has a nanocomposite coating, and the storage groove is arranged in the nanocomposite coating.

7. The rigid-flex circuit board processing apparatus according to claim 1, characterized in that: The machine tool is connected to an oil storage box, the ultrasonic transducer has a second working mode, and the machining spindle has a clean state. The drive unit can drive the tool head of the machining spindle, which is in a clean state, to be placed in the oil reservoir. The ultrasonic transducer, which is in the second working mode, operates at full power to drive the machining spindle to vibrate and clean the tool head.

8. The rigid-flex circuit board processing apparatus according to claim 1, characterized in that: The rigid-flex circuit board processing apparatus includes a temperature detection sensor for detecting the temperature of the surface of the machine tool in contact with the circuit board. The machine tool has a liquid cooling channel that allows liquid to flow. The flow rate of the liquid increases or decreases based on the detection value of the temperature detection sensor to keep the temperature of the machine tool surface within a preset range.

9. A method for manufacturing windows in a rigid-flexible composite plate, characterized in that: Applied to the rigid-flex circuit board processing apparatus as described in any one of claims 1 to 8; the method for fabricating a window in the rigid-flex board includes the following steps: Feeding: The circuit board is fixed to the surface of the machine tool, and the protective film of the flexible area is arranged facing the side of the processing spindle; Window opening processing: After loading, before the drive component drives the processing spindle to move to the preset position of the flexible area, or after the drive component drives the processing spindle to move to the preset position of the flexible area, the ultrasonic transducer enters the first working mode, and the drive component and the processing spindle cooperate to perform window opening processing on the flexible area.

10. The method for manufacturing a window in a rigid-flexible composite plate according to claim 9, characterized in that, The rigid-flex circuit board processing device includes a temperature detection sensor for detecting the temperature of the surface of the machine tool in contact with the circuit board. The machine tool has a liquid cooling channel that allows liquid to flow. The machine is connected to an oil storage box, and the ultrasonic transducer has a second working mode. The method for manufacturing a window in a rigid-flexible composite plate also includes the following steps: Temperature control: Before the window is opened for processing, the liquid is circulated into the liquid cooling channel at a preset speed; During the window opening process, when the temperature detection sensor detects that the temperature of the machine surface is greater than 45°C, the operating power of the liquid pump is increased to increase the speed at which the liquid passes through the liquid cooling channel. When the temperature sensor detects that the temperature rise on the surface of the machine is greater than 0.5℃ / min, the cooler cools the liquid to reduce the temperature of the liquid passing through the liquid cooling channel; When the temperature sensor detects that the temperature of the machine surface is less than 35°C, the liquid is circulated into the liquid cooling channel at a preset speed. Spindle cleaning: Before and after window opening, the drive unit drives the cutting head of the machining spindle to move into the oil reservoir. The ultrasonic transducer enters the second working mode and operates at full power to drive the machining spindle to vibrate and clean the cutting head.

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