A micro / nano-scale imprinting device for forming FPC solder resist layers

Abstract

This invention proposes a micro / nano-scale imprinting FPC solder resist layer forming device, relating to the field of circuit board solder resist layer forming technology. It includes a forming base with a limiting base mounted on it. An imprinting head is positioned directly above the limiting base and driven by a servo electric cylinder. The limiting base has a groove, within which a rigid base is installed. A vacuum adsorption assembly is mounted inside the forming base, and a forming placement cavity is located inside the rigid base. From top to bottom, a PI thin film layer, a silicone layer, and a carbon fiber heating film layer are sequentially arranged at the bottom of the forming placement cavity. Micro / nano patterns are etched on the imprinting head, and a PDMS elastic layer is located at the lower end of the imprinting head. This invention, through the cooperation of the PI thin film layer, silicone layer, carbon fiber heating film layer, and microporous array, can adsorb, flatten, and preheat the FPC substrate before imprinting, fundamentally compensating for the deformation of the flexible substrate and providing a stable and flat reference plane for high-precision imprinting.

Description

Technical Field

[0001] This invention relates to the field of solder resist forming technology for printed circuit boards, and in particular to a micro-nano scale embossing device for forming solder resist layers in FPCs. Background Technology

[0002] With the rapid development of electronic technology, flexible printed circuit boards (FPCs) have become an indispensable key component in modern electronic products. Due to their excellent flexibility, lightweight, and high integration, FPCs are widely used in smartphones, tablets, wearable devices, automotive electronics, medical devices, and other high-tech products.

[0003] The solder mask layer in flexible printed circuit boards (FPCs) is used to define pads, form solder bridges, and provide electrical insulation and surface protection. As device pitch continues to shrink and trace density increases, solder mask patterns are transitioning from the traditional hundreds of micrometers to even smaller micro-nano scales, placing higher demands on pattern edge integrity, linewidth / spacing uniformity, interlayer adhesion, and surface defect control. Existing processes for FPC solder mask molding mainly include: screen printing + thermosetting, inkjet photopolymerization, dry film lamination + exposure and development, and the recently developed molding or roll-forming nanoimprinting. Because FPCs are thin, soft, and easily warped flexible substrates...

[0004] However, due to the susceptibility of flexible substrates to curling memory, uneven tension, and local thickness differences, it is difficult to simultaneously achieve effective adsorption, flattening, and uniform preheating before imprinting / curing. This results in residual air gaps at the interface, local bulges, and thermal drift, leading to incomplete replication, dimensional drift, and alignment errors. Furthermore, during the imprinting process, devices relying solely on single-stage actuation such as motors or cylinders are often open-loop or low-resolution controls, making it difficult to provide fine-grained compensation for contact transitions, final surface pressure, and thermally induced micro-displacements during the micro-nano pattern replication stage. This easily leads to uneven surface pressure distribution and detail collapse. Moreover, traditional step-by-step processes separate imprinting and curing, requiring workpieces to be transported outside the cavity, which easily introduces pattern dragging, particle contamination, and secondary alignment errors, affecting yield and consistency. Therefore, this invention proposes a micro-nano-level imprinting FPC solder resist layer forming device to solve the problems existing in the prior art. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a micro-nano-scale imprinted FPC solder resist forming device. This micro-nano-scale imprinted FPC solder resist forming device provides a high-efficiency and high-precision solution through highly integrated structural design and functional reuse, which can solve the problems in the prior art.

[0006] To achieve the objectives of this invention, the following technical solution is provided: a micro / nano-scale imprinting FPC solder resist layer forming device, comprising a forming base, the forming base having a U-shaped cross-section, and a limiting base mounted on the forming base. An imprinting head is provided directly above the limiting base, and the imprinting head is driven by a servo electric cylinder. The servo electric cylinder is fixedly connected to the forming base via a bracket. The limiting base has a groove, and a rigid base is installed in the groove. A vacuum adsorption component is installed on the inner side of the forming base, and the input end of the vacuum adsorption component communicates with the groove. A forming placement cavity is provided on the inner side of the rigid base. From top to bottom, a PI film layer, a silicone layer, and a carbon fiber heating film layer are sequentially provided at the bottom of the forming placement cavity. Micropore arrays are provided on the rigid base, the PI film layer, the silicone layer, and the carbon fiber heating film layer.

[0007] The output end of the servo electric cylinder is equipped with an upper imprinting seat. A sealing cover is installed on the outside of the upper imprinting seat, and a connecting shell is installed on the inside of the upper imprinting seat. A piezoelectric ceramic displacement device is installed on the inside of the connecting shell, and the output end of the piezoelectric ceramic displacement device is connected to the imprinting head. Micro-nano patterns are etched on the imprinting head, and a PDMS elastic layer is provided at the lower end of the imprinting head.

[0008] A further improvement is that: the inner side of the upper imprint seat is provided with a connecting cavity, and an elastic compensation layer is installed on the inner side of the connecting cavity. The elastic compensation layer is in contact with the connecting shell. Spring limiting pins are installed on both sides of the upper imprint seat. One end of the spring limiting pin extends into the connecting shell and is connected to the connecting shell by a thread.

[0009] Further improvements include: positioning pins are installed on the limiting base, and several sets of positioning pins are evenly distributed; positioning plates are installed on both sides of the upper imprint seat, and positioning holes adapted to the positioning pins are opened on the positioning plates; ultraviolet curing lamps are installed on the inner side of the positioning plates, and the irradiation range of the ultraviolet curing lamps covers the molding placement cavity.

[0010] A further improvement is that: the upper part of the molding base is provided with a first mounting cavity, and two sets of first vacuum pumps arranged symmetrically are installed inside the first mounting cavity. Sealed air extraction ports are installed on both sides of the sealing cover, and the sealed air extraction ports on both sides are connected to the input ends of the two sets of first vacuum pumps through air supply hoses.

[0011] A further improvement is made in that: the molding base is provided with an annular fixing strip, the outer side of the annular fixing strip is fitted with a first sealing ring, the outer side of the first sealing ring is in contact with the inner side of the sealing cover, the molding base is provided with an annular groove, the inner side of the annular groove is provided with a second sealing ring, the lower end of the second sealing ring is connected to the molding base through a spring telescopic member, and several sets of spring telescopic members are evenly provided.

[0012] A further improvement is made in that: the vacuum adsorption assembly includes a second vacuum pump, the lower part of the molding base is provided with a second mounting cavity, the inner side of the second mounting cavity is fixedly connected to the second vacuum pump through a bracket, the molding base is provided with a connecting through hole, the inner cavity of the connecting through hole communicates with the groove, and the lower end of the connecting through hole is threaded with a sealing connector, the sealing connector is connected to the input end of the second vacuum pump through a relay hose.

[0013] A further improvement is made in that: a circulating water pipe is embedded in the inner side of the limiting base, the circulating water pipe is arranged in a U-shape, a circulating water tank is installed in the inner side of the second mounting cavity, and a circulating water pump is installed in the outer side of the circulating water tank. The two ends of the circulating water pump are respectively connected to the circulating water tank and the circulating water pipe through pipes, and one end of the circulating water pipe is connected to the circulating water tank through a pipe.

[0014] A further improvement is that the upper end of the sealing cover is sealed to the upper impression seat, a digital vacuum gauge is installed on the sealing cover, and a transparent observation window is installed on the front side of the sealing cover.

[0015] A further improvement is that a three-way solenoid valve is installed on both the gas delivery hose and the relay hose, with one end of the three-way solenoid valve connected to the outside.

[0016] A further improvement is that when the lower end of the sealing cover contacts the molding base, the imprint head contacts the material placed in the rigid base.

[0017] The beneficial effects of this invention are as follows:

[0018] (1) The present invention forms a multi-layer composite structure in a rigid base by combining a PI thin film layer, a silicone layer, a carbon fiber heating film layer and a micropore array. Combined with a vacuum adsorption component, the FPC substrate can be adsorbed, flattened and preheated before imprinting, which fundamentally compensates for the deformation of the flexible substrate and provides a stable and flat reference plane for high-precision imprinting.

[0019] (2) This invention combines a servo electric cylinder drive with a piezoelectric ceramic displacement device in a macro-micro two-stage drive configuration, which has both large stroke motion capability and nanometer-level fine adjustment function, ensuring that the imprint head can accurately apply the required pressure. At the same time, the PDMS elastic layer can adapt to the micro-undulations of the FPC surface, effectively release stress concentration, protect the precision circuit, and ensure the uniform distribution of imprint pressure.

[0020] (3) By integrating a UV curing lamp inside the sealed cover, this invention achieves seamless connection and in-situ execution of the imprinting and pre-curing processes, completely avoiding pattern damage, contamination, and secondary alignment problems caused by workpiece handling in traditional step-by-step processes, thereby improving production efficiency. In addition, by using a dual vacuum method to extract air from the chamber and adsorb FPC before imprinting, residual air bubbles in the solder resist ink are effectively eliminated, improving the imprinting yield. Attached Figure Description

[0021] Figure 1 This is a front view structural diagram of the present invention.

[0022] Figure 2 This is a front view schematic diagram of the rigid base structure of the present invention.

[0023] Figure 3 This is a front view schematic diagram of the connection structure between the connecting shell and the impression head of the present invention.

[0024] Figure 4 This is a partially enlarged schematic diagram of point A in the present invention.

[0025] Figure 5 This is a top view of the limiting base of the present invention.

[0026] Figure 6 This is a top view schematic diagram of the circulating water pipe of the present invention.

[0027] Figure 7 This is a front view schematic diagram of the present invention in its working state.

[0028] Figure 8 This is a partially enlarged schematic diagram of section B of the present invention.

[0029] The components include: 1. Molding base; 2. Limiting base; 3. Imprint head; 4. Servo electric cylinder; 5. Rigid base; 6. Molding placement cavity; 7. PI film layer; 8. Silicone layer; 9. Carbon fiber heating film layer; 10. Micropore array; 11. Upper imprint seat; 12. Sealing cover; 13. Connecting shell; 14. Piezoelectric ceramic displacement device; 15. PDMS elastic layer; 16. Elastic compensation layer; 17. Spring limiting pin; 18. Positioning pin; 19. Positioning plate; 20. UV curing lamp; 21. First mounting cavity; 22. First UV curing lamp. 23. Empty pump; 24. Sealed air extraction port; 25. Gas delivery hose; 26. Annular fixing strip; 27. First sealing rubber ring; 28. Annular groove; 29. ​​Second sealing rubber ring; 30. Spring telescopic component; 31. Second vacuum pump; 32. Second mounting cavity; 33. Connecting through hole; 34. Sealed connector; 35. Relay hose; 36. Circulating water pipe; 37. Circulating water tank; 38. Circulating water pump; 39. Digital display vacuum gauge; 40. Transparent observation window; 41. Three-way solenoid valve; 42. PLC controller; 43. Light shield. Detailed Implementation

[0030] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0031] according to Figures 1-8 As shown, this embodiment proposes a micro-nano scale imprinted FPC solder resist layer forming device, including a forming machine base 1. The cross-section of the forming machine base 1 is U-shaped. More specifically, the U-shape is vertically arranged, not horizontally arranged.

[0032] A limiting base 2 is installed on the forming base 1. An impression head 3 is positioned directly above the limiting base 2 and is driven by a servo electric cylinder 4. The servo electric cylinder 4 is fixedly connected to the forming base 1 via a bracket, forming a stable support frame. Specifically, an upper impression seat 11 (fixed via a flange) is installed at the output end of the servo electric cylinder 4, ensuring direct and unbiased force transmission. Thus, under the action of the servo electric cylinder 4, the entire upper assembly (upper impression seat 11, sealing cover 12, impression head 3, etc.) is driven to perform a large-stroke (e.g., greater than 15cm) lifting motion, achieving a rapid transition between the initial open state (facilitating loading and unloading) and the final closed working state. After closing, the servo electric cylinder 4 can output and maintain a stable reference pressure, providing a foundation for subsequent precision imprinting.

[0033] A sealing cover 12 is installed on the outer side of the upper impression base 11. The upper end of the sealing cover 12 is sealed to the upper impression base 11 using sealing screws and O-rings, forming an inverted "bell jar" structure. Correspondingly, when the lower end of the sealing cover 12 contacts the forming base 1, a sealed chamber is formed. This chamber can be evacuated to remove air and prevent the solder resist ink from generating bubbles during the printing process, which is crucial for ensuring yield.

[0034] A connecting shell 13 is installed inside the upper impression holder 11, and a piezoelectric ceramic displacement device 14 is installed inside the connecting shell 13. The output end of the piezoelectric ceramic displacement device 14 is connected to the impression head 3. Specifically, its output end is directly connected to the top center of the impression head 3 through a high-rigidity, low-inertia connector (usually made of ceramic or hardened steel). After the servo electric cylinder 4 completes macroscopic positioning and provides reference pressure, the piezoelectric ceramic displacement device 14 begins to work. It can generate nanometer-level resolution (e.g., 0.1 nm) and millisecond-level micro-telescopic displacements (strokes are typically in the micrometer range) according to the control signal.

[0035] Furthermore, micro- and nano-patterns (e.g., 50nm linewidth solder resist trenches) are etched onto the imprint head 3 (made entirely of epoxy resin, Shore D hardness 80) using laser direct writing. A PDMS (polydimethylsiloxane) elastic layer 15 (40µm thick, Shore A hardness 15) is located at the lower end of the imprint head 3, forming a composite structure of a "rigid pattern carrier and flexible buffer layer." The imprint head 3, acting as the pattern carrier, has the core function of faithfully transferring the etched micro- and nano-patterns onto the solder resist ink of the FPC. During this process, the low elastic modulus of the PDMS elastic layer 15 (approximately 0.1–1MPa) allows it to deform synchronously with the minute undulations of the FPC surface (e.g., height difference in line bending areas ≤1µm) during imprinting. When the imprint head 3 contacts the raised area of ​​the FPC, the PDMS elastic layer 15 is compressed (compression rate ≤10%), dispersing the localized concentrated pressure to the surrounding area (pressure deviation reduced from ±20% to ±5%), preventing the copper foil from breaking due to excessive local pressure (>2MPa). When there are recessed areas in the FPC, the PDMS elastic layer 15 fills the recessed gaps through its own rebound (filling depth ≤50µm), ensuring complete contact between the imprint head pattern and the solder resist ink, avoiding uneven or missing ink filling. Furthermore, the high elasticity of the PDMS elastic layer 15 (elongation at break ≥500%) allows it to form "surface contact" rather than "point contact" when in contact with the FPC. Combined with its ultra-low shear modulus (≤0.5MPa·cm), it can evenly distribute the total pressure applied by the imprint head (0.5~2MPa) to the FPC surface (contact area ratio ≥95%), further reducing the risk of localized stress concentration.

[0036] This composite design of "rigid pattern carrier and flexible buffer layer" not only ensures high-fidelity transfer of micro and nano patterns (linewidth deviation ≤ ±5nm), but also effectively solves the imprinting problems of fragile and uneven FPC copper foil (copper foil breakage rate ≤ 0.1%).

[0037] When the lower end of the sealing cover 12 contacts the molding base 1, the imprint head 3 contacts the material placed in the rigid base 5. The sealing cover 12 also provides a coarse positioning effect. Specifically, when the device performs the imprinting action, the sealing cover 12 moves vertically downward under the push of the servo electric cylinder 4 until its lower end face makes rigid contact with the upper surface of the molding base 1 (the contact pressure is guaranteed by the control accuracy of the servo electric cylinder 4, with a deviation ≤ ±0.05mm). At this time, the imprint head 3 inside the sealing cover 12 moves downward synchronously until the lower end face of the imprint head 3 contacts the surface of the material (FPC substrate, copper foil layer, and solder resist ink) in the rigid base 5, thus providing a clear starting position (error ≤ ±0.2mm) for the subsequent piezoelectric ceramic displacement device 14 to drive the imprint head 3 to contact the material (fine positioning).

[0038] The upper part of the molding base 1 is provided with a first mounting cavity 21. Two sets of first vacuum pumps 22 are symmetrically arranged inside the first mounting cavity 21. Sealed air extraction ports 23 are installed on both sides of the sealing cover 12. The sealed air extraction ports 23 on both sides are connected to the input ends of the two sets of first vacuum pumps 22 through air supply hoses 2301. At the same time, a digital display vacuum gauge 37 is installed on the sealing cover 12 to monitor the vacuum degree inside the sealing cover 12 in real time (accuracy ±0.1kPa, range -10~0kPa), and the value is displayed on the LED display screen (e.g. -7.5kPa). A transparent observation window 38 (sealed connection) is installed on the front side of the sealing cover 12. Furthermore, a light shield 41 is installed on the front side of the sealing cover 12 through a hinge to block the transparent observation window 38 when not being observed. After the lower end of the sealing cover 12 contacts the forming base 1, the first vacuum pump 22 is started, and both pumps work simultaneously with a total pumping speed of 200 L / s. Then, air in the chamber is extracted through the gas supply hose 2301 (for example, the initial air pressure is atmospheric pressure of 101 kPa). The digital vacuum gauge 37 displays the vacuum level change in real time (for example, it drops to -8 kPa within 30 seconds), and finally stabilizes at the target vacuum level (such as -8 to -10 kPa). By using vacuum extraction, the possibility of residual air during the printing process is avoided, which would affect the pattern transfer accuracy.

[0039] The limiting base 2 has a groove, and a rigid base 5 is installed in the groove. The inner wall of the groove is ground to ensure a tight fit with the rigid base 5. The rigid base 5 is fixedly connected to the limiting base 2 by bolts, limiting the displacement of the rigid base 5 in the X / Y / Z axis directions (deviation ≤ ±0.1mm). The inner side of the rigid base 5 has a molding placement cavity 6, the size of which matches the FPC substrate. From top to bottom, the bottom of the molding placement cavity 6 has a PI film layer 7, a silicone layer 8, and a carbon fiber heating film layer 9, which are bonded together with epoxy resin adhesive (thickness 0.05mm, shear strength ≥2MPa) to form a composite structure of "rigid support and functional layer". Micropore arrays 10 are provided on the rigid base 5, PI film layer 7, silicone layer 8, and carbon fiber heating film layer 9. Furthermore, the PI film layer 7 (thickness 25µm, temperature resistance ≥300℃, surface energy ≈30mN / m) serves as the reference contact surface. Its high flatness (Ra≤0.1µm) ensures that the FPC substrate (PI / copper foil) is placed without tilting (flatness deviation ≤±5µm). The lower surface of the PI film layer 7 (the side in contact with the silicone layer 8) is etched with a micropore array 10 (pore diameter 100μm, spacing 2mm), and the pore depth ≤10µm (to avoid penetrating the PI film). This is used for the transfer of adsorption force in the vacuum adsorption component (the vacuum pressure is uniformly applied to the non-circuit area of ​​the FPC through the micropores). The silicone layer 8 (thickness 80µm, Shore A hardness 115, elastic modulus 0.3MPa) is used to absorb the rigid contact stress between the FPC substrate and the rigid base 5 (to prevent the Cu foil circuit from breaking due to excessive local pressure). Correspondingly, the upper and lower surfaces of the silicone layer 8 (the sides in contact with the PI film layer 7 and the carbon fiber heating film layer 9) are etched with micropore arrays 10 (pore diameter 50µm, spacing 1mm), with a pore depth ≤20µm. The micropore arrays of the silicone layer 8 are staggered with those of the PI film layer 7 (offset ≤0.5mm) to avoid concentrated adsorption forces (to prevent local deformation of the FPC). The carbon fiber heating film layer 9 (thickness 0.3mm, power density 50W / m², temperature resistance ≥200℃) has its heating power (range 0~50W) adjusted via an external power supply (wire through-hole connection), thereby regulating the temperature within the molding cavity 6. A micropore array 10 (pore diameter 25µm, spacing 0.5mm) with a depth ≤15µm is etched on the upper surface of the carbon fiber heating film layer 9 (the side in contact with the silicone layer 8), partially overlapping with the micropore array 10 of the silicone layer 8 (overlap rate ≥30%). This ensures the conductivity of the heating film (avoiding micropores from damaging the circuit) and enhances the heat transfer efficiency to the FPC. The carbon fiber heating film layer 9 is made of dense carbon fiber woven fabric (porosity ≤5%), and the micropore array 10 is etched on its upper surface using laser etching, allowing air to pass freely through. The micropore array 10 of the rigid base 5 adopts a through-hole design, completely overlapping with the micropore array 10 of the silicone layer 8.

[0040] Meanwhile, the rigid base 5 has wire through holes on its side, which are used to allow external power supply equipment to control the working state of the carbon fiber heating film layer 9 via wire connection. Correspondingly, the micropore array 10 is used to cooperate with the subsequent vacuum adsorption component, that is, the vacuum adsorption component is installed on the inner side of the molding base 1, and the input end of the vacuum adsorption component is connected to the groove.

[0041] The vacuum adsorption assembly includes a second vacuum pump 29. A second mounting cavity 30 is provided in the lower part of the forming base 1. The inner side of the second mounting cavity 30 is fixedly connected to the second vacuum pump 29 via a bracket. The forming base 1 has a connecting through hole 31, the inner cavity of which communicates with a groove. A sealing connector 32 is threaded onto the lower end of the connecting through hole 31. The sealing connector 32 is connected to the input end of the second vacuum pump 29 via a relay hose 33. During operation, the second vacuum pump 29 operates, rapidly extracting air from the groove of the forming base 1. This air is then applied to the FPC substrate through the microporous array 10 (total adsorption area ≥90%) of the rigid base 5, PI film layer 7, silicone layer 8, and carbon fiber heating film layer 9. The FPC substrate is uniformly adsorbed within the forming placement cavity 6 (contact pressure ≥0.1MPa), ultimately providing a stable, uniform, and controllable environment for micro / nano-level solder resist lamination.

[0042] Furthermore, a temperature sensor can be integrated on the rigid base 5 for temperature monitoring.

[0043] The upper impression seat 11 has a connecting cavity on its inner side, and an elastic compensation layer 16 is installed inside the connecting cavity. The elastic compensation layer 16 contacts the connecting shell 13. Spring limiting pins 17 are installed on both sides of the upper impression seat 11. One end of the spring limiting pin 17 extends into the connecting shell 13 and is connected to the connecting shell 13 by threads. The spring limiting pin 17 (composed of a limiting pin and a spring, with one end of the spring connected to the upper impression seat 11 and the other end connected to the limiting pin; when the limiting pin is pulled out, the spring is stretched and generates a corresponding traction force) facilitates the disassembly and installation of the connecting shell 13 (corresponding to the impression head 3). Furthermore, when one end of the spring limiting pin 17 is inserted into the connecting shell 13, the operator can rotate it to connect it by threads, thereby achieving a transition from elastic pre-tightening to rigid locking.

[0044] Furthermore, the elastic compensation layer 16 is compressed under imprinting pressure (0.5~2MPa) (e.g., the thickness is reduced from 10mm to 8mm), during which local pressure is distributed to the entire bottom surface of the connecting shell 13 (contact area ratio ≥95%), ensuring that the force on the piezoelectric ceramic and the imprinting head is uniform.

[0045] Positioning pins 18 are installed on the limiting base 2, and several sets of positioning pins 18 are evenly arranged. In this embodiment, four sets of positioning pins 18 are evenly arranged. Positioning plates 19 are installed on both sides of the upper imprint seat 11, and positioning holes adapted to the positioning pins 18 are opened on the positioning plates 19. Ultraviolet curing lamps 20 are installed on the inner side of the positioning plates 19, and the irradiation range of the ultraviolet curing lamps 20 covers the molding placement cavity 6. When the lower end of the sealing cover 12 contacts the molding base 1, the positioning plate 19 contacts the limiting base 2, and at this time, the positioning pins 18 pass through the positioning holes at the corresponding positions. During operation, pressing is performed, and after the pressing is complete, the vacuum environment is discharged. Then, the servo electric cylinder 4 drives the upper imprint seat 11 to move upward. At this time, the movement is not fully unfolded. It is moved to a position where the irradiation range of the ultraviolet curing lamps 20 can cover the molding placement cavity 6, that is, its light spot can completely cover the entire FPC workpiece in the molding placement cavity 6. The UV curing lamp 20 is activated to initially cure the imprinted solder resist layer (UV-curable solder resist ink). Since the workpiece is not moved, the pattern does not undergo rheology or displacement, exhibiting excellent shape retention. A brief irradiation then causes the ink to solidify from a liquid state (reaching approximately 70% curing), sufficient to fix the pattern shape. Afterward, the entire pattern is fully unfolded (the upper imprinting seat 11 moves upward to its highest position), and the operator removes the imprinted FPC for further processing. The engagement of the positioning pin 18 and the positioning hole again provides a positioning effect. Simultaneously, after mold closing, together with the sealing cover 12, they form an extremely rigid overall frame, providing a stable mechanical environment for subsequent nanoscale imprinting.

[0046] The molding base 1 is provided with an annular fixing strip 24. A first sealing ring 25 is attached to the outer side of the annular fixing strip 24, and the outer side of the first sealing ring 25 contacts the inner side of the sealing cover 12. An annular groove 26 is provided on the molding base 1, and a second sealing ring 27 is provided on the inner side of the annular groove 26. The lower end of the second sealing ring 27 is connected to the molding base 1 through a spring telescopic member 28, and several sets of spring telescopic members 28 are evenly provided. The cooperation of the first sealing ring 25 and the second sealing ring 27 enhances the sealing performance at the connection between the sealing cover 12 and the molding base 1.

[0047] A circulating water pipe 34 is embedded inside the limiting base 2. The circulating water pipe 34 is U-shaped. A circulating water tank 35 is installed inside the second mounting cavity 30, and a circulating water pump 36 is installed outside the circulating water tank 35. The two ends of the circulating water pump 36 are connected to the circulating water tank 35 and the circulating water pipe 34 respectively through pipes. One end of the circulating water pipe 34 is connected to the circulating water tank 35 through a pipe. During the imprinting process, the carbon fiber heating film layer 9 generates heat, which is conducted downward to the rigid base 5 and the limiting base 2. The circulating water pipe 34 is embedded inside the limiting base 2 as a heat exchanger. Deionized water is then filled into the circulating water tank 35 and circulated by the circulating water pump 36 to remove the heat absorbed by the limiting base 2, thereby reducing the negative impact of the internal heat source.

[0048] Both the gas supply hose 2301 and the relay hose 33 are equipped with three-way solenoid valves 39, one end of which is connected to the outside. This device also includes a PLC controller 40, used to connect to and control all electronic components within the device. Furthermore, the three-way solenoid valve 39 is used to open and close according to control commands (manual operation or program programming) from the PLC controller 40 to release the corresponding vacuum environment.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the present invention without departing from its framework and scope of application, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A micro / nano-scale imprinting FPC solder resist layer forming device, comprising a forming base (1), the forming base (1) having a U-shaped cross section, and a limiting base (2) mounted on the forming base (1), an imprinting head (3) being provided directly above the limiting base (2), and the imprinting head (3) being driven by a servo electric cylinder (4), the servo electric cylinder (4) being fixedly connected to the forming base (1) via a bracket, characterized in that: The limiting base (2) is provided with a groove, and a rigid base (5) is installed in the groove. A vacuum adsorption component is installed on the inner side of the molding base (1). The input end of the vacuum adsorption component is connected to the groove. A molding placement cavity (6) is provided on the inner side of the rigid base (5). A PI film layer (7), a silicone layer (8) and a carbon fiber heating film layer (9) are provided sequentially from top to bottom at the bottom of the molding placement cavity (6). A micropore array (10) is provided on the rigid base (5), the PI film layer (7), the silicone layer (8) and the carbon fiber heating film layer (9). The output end of the servo electric cylinder (4) is equipped with an upper imprint seat (11), the outer side of the upper imprint seat (11) is equipped with a sealing cover (12), and the inner side of the upper imprint seat (11) is equipped with a connecting shell (13). The inner side of the connecting shell (13) is equipped with a piezoelectric ceramic displacement device (14), and the output end of the piezoelectric ceramic displacement device (14) is connected to the imprint head (3). The imprint head (3) is etched with micro-nano patterns, and the lower end of the imprint head (3) is provided with a PDMS elastic layer (15).

2. The micro / nano-scale imprinting FPC solder resist layer forming device according to claim 1, characterized in that: The upper imprint seat (11) has a connecting cavity on its inner side, and an elastic compensation layer (16) is installed on the inner side of the connecting cavity. The elastic compensation layer (16) is in contact with the connecting shell (13). Spring limiting pins (17) are installed on both sides of the upper imprint seat (11). One end of the spring limiting pin (17) extends into the connecting shell (13) and is connected to the connecting shell (13) by a thread.

3. The micro / nano-scale imprinting FPC solder resist layer forming device according to claim 1, characterized in that: The limiting base (2) is equipped with positioning pins (18), and the positioning pins (18) are evenly arranged in several groups. The upper imprint seat (11) is equipped with positioning plates (19) on both sides, and the positioning plates (19) are provided with positioning holes that are compatible with the positioning pins (18). The inner side of the positioning plate (19) is equipped with an ultraviolet curing lamp (20), and the irradiation range of the ultraviolet curing lamp (20) covers the molding placement cavity (6).

4. The micro / nano-scale imprinting FPC solder resist layer forming device according to claim 1, characterized in that: The upper part of the molding base (1) is provided with a first mounting cavity (21). Two sets of first vacuum pumps (22) are installed on the inner side of the first mounting cavity (21). Sealed air extraction ports (23) are installed on both sides of the sealing cover (12). The sealed air extraction ports (23) on both sides are connected to the input ends of the two sets of first vacuum pumps (22) through air supply hoses (2301).

5. The micro / nano-scale imprinting FPC solder resist layer forming device according to claim 1, characterized in that: The molding base (1) is provided with an annular fixing strip (24). A first sealing ring (25) is attached to the outer side of the annular fixing strip (24). The outer side of the first sealing ring (25) is in contact with the inner side of the sealing cover (12). An annular groove (26) is provided on the molding base (1). A second sealing ring (27) is provided on the inner side of the annular groove (26). The lower end of the second sealing ring (27) is connected to the molding base (1) through a spring telescopic member (28). Several sets of spring telescopic members (28) are evenly provided.

6. The micro / nano-scale imprinting FPC solder resist layer forming device according to claim 4, characterized in that: The vacuum adsorption assembly includes a second vacuum pump (29). The lower part of the molding base (1) is provided with a second mounting cavity (30). The inner side of the second mounting cavity (30) is fixedly connected to the second vacuum pump (29) through a bracket. The molding base (1) is provided with a connecting through hole (31). The inner cavity of the connecting through hole (31) is connected to the groove. The lower end of the connecting through hole (31) is threaded with a sealing connector (32). The sealing connector (32) is connected to the input end of the second vacuum pump (29) through a relay hose (33).

7. The micro / nano-scale imprinting FPC solder resist layer forming device according to claim 6, characterized in that: The inner side of the limiting base (2) is embedded with a circulating water pipe (34), which is arranged in a U-shape. The inner side of the second mounting cavity (30) is equipped with a circulating water tank (35), and the outer side of the circulating water tank (35) is equipped with a circulating water pump (36). The two ends of the circulating water pump (36) are respectively connected to the circulating water tank (35) and the circulating water pipe (34) through pipes. One end of the circulating water pipe (34) is connected to the circulating water tank (35) through a pipe.

8. The micro / nano-scale imprinting FPC solder resist layer forming device according to claim 1, characterized in that: The upper end of the sealing cover (12) is sealed to the upper imprint seat (11), a digital vacuum gauge (37) is installed on the sealing cover (12), and a transparent observation window (38) is installed on the front side of the sealing cover (12).

9. The micro / nano-scale imprinting FPC solder resist layer forming device according to claim 6, characterized in that: Both the gas delivery hose (2301) and the relay hose (33) are equipped with a three-way solenoid valve (39), one end of which is connected to the outside.

10. The micro / nano-scale imprinting FPC solder resist layer forming device according to claim 1, characterized in that: When the lower end of the sealing cover (12) contacts the molding base (1), the imprint head (3) contacts the material placed in the rigid base (5).

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