Flexible circuit board carrier structure for automated production

Abstract

The present application belongs to the technical field of circuit carrying, and particularly relates to a flexible circuit board carrying structure for automatic production, which comprises a polyimide base material coated with a nanoscale insulation layer on the surface, and two layers of copper foils symmetrically distributed and wrapped on the upper and lower sides of the polyimide base material. In the present application, side protrusions are linearly arrayed and clamped on both sides of the polyimide base material. When the base material and the copper foils are bent due to shearing force, the two side protrusions close to each other can contact each other and provide mechanical support, thereby enhancing the bonding strength and anti-layering capacity of the copper foils and the base material under repeated bending or temperature change stress. The recessed groove region formed between the side protrusions becomes the main bonding and fixing position of the insulation adhesive surface between the two copper foils. The three-dimensional support and local reinforcement adhesive structure enhances the bonding strength and anti-layering capacity of the copper foils and the base material under repeated bending or temperature change stress, and improves the mechanical reliability and service life of the product.

Description

Technical Field

[0001] This invention belongs to the field of circuit support technology, specifically relating to a flexible circuit board support structure for automated production. Background Technology

[0002] In current automated production systems for flexible printed circuit boards (FPCs), the commonly used load-bearing structures rely on polyimide substrates with flat surfaces or only simple positioning holes.

[0003] Although this type of structure achieves overall alignment through mechanical positioning holes during copper foil cladding and subsequent assembly, it is difficult to control the local bonding behavior between the copper foil and the substrate at the microscopic level.

[0004] Especially in high-speed, continuous production environments, copper foil is prone to slippage or local wrinkling during hot pressing and conveying, leading to the accumulation of line alignment deviations and affecting the accuracy and consistency of electrical connections.

[0005] Meanwhile, the uniformity of adhesive layer distribution on the surface of traditional flat substrates is significantly affected by process fluctuations, which can easily lead to problems such as uneven adhesive layer thickness and insufficient local adhesion. Under repeated bending or temperature stress, the copper foil and the substrate are prone to delamination and peeling, thereby reducing the mechanical reliability and service life of the product.

[0006] Furthermore, as electronic products move towards high-density integration and thinness, the width of FPC circuits continues to shrink, and the requirements for bonding accuracy have entered the micron level. Traditional structures are unable to achieve stable large-scale production without relying on manual intervention or complex auxiliary tooling. This not only limits the increase in production capacity, but also increases the complexity of process debugging and quality control.

[0007] To compensate for the deficiencies in alignment and bonding, existing processes often require increasing the amount of adhesive or introducing multi-layer positioning structures, resulting in material waste, increased costs, and cumbersome subsequent finishing and cleaning processes, which is not conducive to improving production cycle and resource efficiency.

[0008] These factors together restrict the promotion of FPC in high-reliability and high-precision application scenarios, and also hinder the deep integration and application iteration of intelligent manufacturing systems in the field of flexible electronics. Summary of the Invention

[0009] To address the aforementioned problems in the prior art, this invention provides a flexible circuit board support structure for automated production. The aim is to solve the technical problem in the prior art where delamination and peeling easily occur between the copper foil and the substrate under repeated bending or temperature stress, thereby reducing the mechanical reliability and service life of the product.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a flexible circuit board support structure for automated production, comprising: a polyimide substrate, a flexible material with a thickness of 0.15 mm, wherein the surface of the polyimide substrate is coated with a nanoscale insulating layer; two layers of copper foil, symmetrically distributed and covering the upper and lower sides of the polyimide substrate; side protrusions are linearly arrayed and snap-fitted onto both sides of the polyimide substrate for contact between the two side protrusions that come closer together due to bending when the polyimide substrate and the copper foil are subjected to shear force bending; the two ends of the side protrusions have semi-circular cross sections to provide the contact area between the two side protrusions; and a recessed groove is formed between the two side protrusions.

[0011] Furthermore, the polyimide substrate has multiple rectangular positioning holes arrayed on both sides for positioning during the production process.

[0012] Furthermore, both the polyimide substrate and the copper foil covering its surface are formed with through holes using a laser drilling process.

[0013] Furthermore, the copper foil surface is provided with a contact patch group, a connecting patch group, and an antenna layer.

[0014] Furthermore, the contact pad group includes six gold-plated contacts arranged according to the ISO78162 standard, and the contact surface is coated with nano-diamond; the back of the connecting pad group is provided with seven copper-based connecting pads, and is connected to the integrated circuit pins through die bonding wires; the antenna layer adopts an FPC structure and uses a copper-based etched antenna coil, and the antenna coil and the chip are flexibly connected through wire bonding technology.

[0015] Furthermore, the copper foil forms a groove when it covers the side protrusion and the recessed groove.

[0016] Furthermore, the area where the two copper foils adhere is provided with an insulating adhesive surface, and the two different insulating adhesive surfaces are bonded and fixed together by insulating adhesive, with most of the bonding and fixing points between the two insulating adhesive surfaces located between the recessed grooves.

[0017] Furthermore, the end of the side bump away from the polyimide substrate is designed as an end rounded surface to increase the contact area between the end of the side bump and the copper foil.

[0018] Furthermore, the polyimide substrate has contact arc grooves on the sides near the copper foil to reduce the difficulty of creating the through holes.

[0019] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, by linearly arraying and snapping side protrusions on both sides of the polyimide substrate, when the substrate and the copper foil are bent by shear force, the two side protrusions that are close to each other due to bending can contact each other and provide mechanical support, thereby enhancing the bonding strength and anti-delamination ability of the copper foil and the substrate under repeated bending or thermal stress. 2. In this invention, the recessed groove area formed between the side protrusions becomes the main bonding and fixing position of the insulating adhesive surface between the two copper foils. This three-dimensional support and locally reinforced bonding structure transforms the traditional uniform force on the surface into a synergistic effect of the side protrusions providing bending stiffness and the recessed groove area providing anchoring force, further enhancing the bonding strength and anti-delamination ability of the copper foil and the substrate under repeated bending or temperature stress, and improving the mechanical reliability and service life of the product. 3. In this invention, when the copper foil covers the side protrusions and the recessed grooves, it will naturally form corresponding forming grooves. This non-planar three-dimensional covering method provides additional physical constraints and guidance for the copper foil. During the hot pressing process of automated production, the contour of the side protrusions can effectively constrain the lateral slippage of the copper foil and suppress the generation of local wrinkles. 4. In this invention, the adhesive is actively guided and concentratedly applied to the recessed groove design area, which reduces the thickness fluctuation of the adhesive layer in the flat area and ensures the stability and uniformity of the bonding force. This structure actively controls the bonding behavior of the copper foil at the micro level, providing a guarantee for achieving high-precision and high-consistency alignment and connection of micron-level circuits. 5. In this invention, the side protrusion structure design, such as the end round surface and semi-circular cross-section, enhances local support while avoiding stress concentration, giving the load-bearing structure better flexibility and adaptive deformation capability when bent. The rectangular positioning hole array on both sides of the polyimide substrate, in conjunction with the visual recognition system of the production equipment, achieves precise automatic alignment. The regular microstructure formed by the side protrusions and recessed grooves facilitates precise positioning and processing in subsequent processes such as laser drilling, forming through holes and contact arc grooves 3, without relying on complex auxiliary tooling or excessive adhesives. This simplifies the production process, reduces sensitivity to process fluctuations, and significantly improves the stability, yield, and resource efficiency of flexible circuit boards in large-scale, high-speed, continuous automated production. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the present invention; Figure 2 This is a schematic diagram of the copper foil in this invention; Figure 3 This is an exploded view of the contact arc groove in this invention; Figure 4 This is an exploded view of the side protrusion in this invention.

[0021] Legend: 1. Polyimide substrate; 101. Copper foil; 2. Side protrusions; 3. Contact arc groove; 4. Forming a groove; 5. Insulating adhesive surface; 6. End round surface; 7. Recessed groove. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1: Please see Figure 1 Figure 4 This embodiment provides the following technical solution: a flexible circuit board support structure for automated production, comprising: a polyimide substrate 1, a flexible material with a thickness of 0.15 mm, the surface of the polyimide substrate 1 being coated with a nanoscale insulating layer; and two copper foils 101, symmetrically distributed and covering the upper and lower sides of the polyimide substrate 1.

[0024] Multiple rectangular positioning holes are arrayed on both sides of the polyimide substrate 1 for positioning during the production process.

[0025] Both the polyimide substrate 1 and the copper foil 101 covering its surface are formed with through holes by laser drilling.

[0026] The surface of copper foil 101 is provided with contact plate group, connecting plate group and antenna layer.

[0027] The contact pad assembly includes six gold-plated contacts arranged according to the ISO78162 standard, and the contact surface is coated with nano-diamond. The back of the connector assembly has seven copper-based connectors, which are connected to the integrated circuit pins via die bond wire bonding. The antenna layer adopts an FPC structure and uses a copper-based etched antenna coil. The antenna coil and the chip are flexibly connected via wire bonding technology.

[0028] Specifically, the polyimide substrate 1 is a flexible insulating material with a thickness of 0.15 mm and a nanoscale insulating layer coated on its surface, which is suitable for ultra-thin smart card packaging; Two layers of copper foil 101 are symmetrically distributed and completely cover the upper and lower surfaces of the polyimide substrate 1, together forming an integrated flexible carrier that can support contact and non-contact circuits. Rectangular positioning holes are used in conjunction with vision recognition systems or mechanical positioning devices during automated production processes to achieve precise alignment of the load-bearing structure throughout the entire process; The polyimide substrate 1 and the copper foil 101 covering its surface are both formed with micron-level through holes by laser drilling process to realize three-dimensional electrical connection between the upper and lower circuit layers and meet the requirements of high-density interconnection. The surface of copper foil 101 is provided with contact patch group, connecting patch group and antenna layer, which together form an integrated circuit module that supports dual interface communication. This structure is suitable for smart card strips and realizes the co-carrier design of contact interface and non-contact antenna. The nanodiamond coating on the contact pads gives them a contact life of over 200,000 cycles. The tensile strength of the connecting piece assembly shall not be less than 3N; The antenna layer is fabricated using flexible printed circuit board (FPC) technology and is a copper-based etched spiral antenna coil. The antenna coil is flexibly connected to the chip through wire bonding technology, and the antenna inductance is not less than 15μH.

[0029] Preferably, a highly flexible and highly insulating basic support structure is formed by setting a polyimide substrate 1 with a thickness of 0.15 mm and a surface coated with a nano-level insulating layer and two layers of copper foil 101 symmetrically covering its upper and lower sides, providing a physical carrier for subsequent functional integration.

[0030] Furthermore, by arraying multiple rectangular positioning holes on both sides of the polyimide substrate 1, a high-precision mechanical and visual positioning benchmark is provided for the transfer, alignment, lamination and subsequent processing of the entire load-bearing structure on the automated production line, which is a prerequisite for achieving efficient and precise automated production.

[0031] Meanwhile, by using laser drilling technology to form through holes on the polyimide substrate 1 and the copper foil 101 it covers, high-precision and high-reliability vertical electrical interconnection between double-sided and multi-layer circuits is achieved, meeting the requirements of high-density wiring.

[0032] Furthermore, a gold-plated contact pad group conforming to ISO78162 standard, a copper-based connecting pad group connected by die bonding wires, and a copper-based etched antenna layer with an FPC structure are integrated on the surface of copper foil 101. This enables the carrier structure to support both contact and contactless communication functions simultaneously, achieving a high degree of integration of the dual-interface smart card module and significantly improving the functionality and adaptability of the product.

[0033] Both sides of the polyimide substrate 1 are linearly arrayed with side protrusions 2 for contact between the two side protrusions 2 when the polyimide substrate 1 and the copper foil 101 are bent by shear force; the two ends of the side protrusions 2 are semi-circular to provide the contact area between the two side protrusions 2; a recessed groove 7 is formed between the two side protrusions 2.

[0034] Preferably, a core micro-reinforcement structure is constructed by linearly arraying and attaching side protrusions 2 to both sides of the polyimide substrate 1, making their two ends semi-circular, and forming recessed grooves 7 between adjacent side protrusions 2. When the load-bearing structure is subjected to shear force bending, the side protrusions 2 that move closer together due to bending can contact each other through their semi-circular end faces and provide direct mechanical support and restraint, effectively suppressing excessive local deformation. Meanwhile, the recessed groove 7 area provides space for the concentrated application of subsequent adhesives, thereby transforming the traditional overall surface stress mode into a reinforcement mode in which the side protrusion 2 supports and the recessed groove 7 anchors in synergy. This fundamentally and significantly improves the bending resistance, delamination resistance, and overall mechanical reliability between the copper foil 101 and the polyimide substrate 1.

[0035] The copper foil 101 forms a forming groove 4 when covering the side protrusion 2 and the recessed groove 7.

[0036] The end of the side bump 2 away from the polyimide substrate 1 is provided as an end round surface 6 to increase the contact area between the end of the side bump 2 and the copper foil 101.

[0037] Specifically, when the copper foil 101 covers the side protrusion 2 and the recessed groove 7, a forming groove 4 that is consistent with the contour of the substrate is formed. This structure provides lateral restraint for the copper foil 101 and suppresses its slippage and wrinkling during the hot pressing process. The end round surface 6 is used to increase the contact area between the end of the side protrusion 2 and the inner surface of the copper foil 101, reduce stress concentration, and improve bending reliability.

[0038] Preferably, since the copper foil 101 covers the surface of the substrate having the side protrusions 2 and the recessed grooves 7, it will naturally form a forming groove 4 that matches the contours of the side protrusions 2 and the recessed grooves 7. This three-dimensional conformal structure provides additional physical constraints for the copper foil 101, which can effectively constrain the lateral slippage and wrinkling of the copper foil 101 during production processes such as hot pressing and lamination. Furthermore, by setting the end of the side protrusion 2 away from the substrate as the end round surface 6, the contact area between the top of the side protrusion 2 and the inner surface of the copper foil 101 covering it is increased, the stress distribution is optimized, and the local stress concentration or damage to the copper foil 101 that may be caused by sharp edges is avoided, making the support contact smoother and more reliable.

[0039] The joint between the two copper foils 101 is set as an insulating adhesive surface 5. The two different insulating adhesive surfaces 5 are bonded and fixed together by insulating adhesive, and most of the bonding and fixing points between the two insulating adhesive surfaces 5 are located between the recessed grooves 7.

[0040] Specifically, the bonding and fixing area of ​​the insulating adhesive is mainly distributed in the area between the recessed grooves 7, forming local reinforced anchor points and improving the anti-delamination ability.

[0041] Preferably, the area where two copper foils 101 are bonded and fixed together with insulating adhesive is defined as insulating adhesive surface 5, and it is specifically stipulated that most of the bonding and fixing points between the two insulating adhesive surfaces 5 are located between the recessed grooves 7, thereby achieving precise application of adhesive and regional reinforcement. By concentrating the main adhesive force on the recessed groove 7 area enclosed by the side protrusion 2, which is less affected by shear, rather than the entire plane, the effectiveness and uniformity of the bond are significantly improved. This ensures that the adhesive layer can still provide a durable and stable anchoring force under repeated bending stress, and greatly enhances the interlayer bond strength.

[0042] Contact arc grooves 3 are provided on the sides of the polyimide substrate 1 near the copper foil 101 to reduce the difficulty of creating the through holes.

[0043] Specifically, the contact groove 3 is used to provide process tolerance when forming through holes by laser drilling, reduce drilling difficulty, and improve hole position accuracy and consistency.

[0044] Preferably, by opening a contact arc groove 3 on the side of the polyimide substrate 1 near the copper foil 101, an arc-shaped guiding and buffering structure is provided in advance at the position where laser drilling is required to form a through hole; This design reduces the processing difficulty of drilling holes in the polyimide substrate 1 after the laser beam penetrates the copper foil 101, which helps to obtain more regular and precise hole wall quality, reduce the heat-affected zone, and thus improve the processing yield of vias and the reliability of electrical interconnection. It is particularly suitable for the processing requirements of micron-level high-density interconnection.

[0045] Example 2: Please see Figure 1 Figure 4 In this embodiment, the staff used the equipment disclosed in this invention on the automated production line of an international smart card manufacturing company; To meet the stringent requirements of high reliability and ultra-long bending life for the new generation of dual-interface financial IC cards, its core flexible circuit module adopts the flexible circuit board support structure for automated production described in this invention.

[0046] In specific implementation, a DuPont Kapton polyimide film with a thickness of 0.15 mm is selected as the polyimide substrate 1. A 50 nm thick silicon dioxide insulating layer is pre-coated onto its surface using a vapor deposition process. On both long sides of the polyimide substrate 1, linearly arrayed side protrusions 2 are integrally formed using a precision mold hot-pressing process. Each side protrusion 2 has a width of 0.5 mm and a height of 0.2 mm. The center-to-center distance between adjacent side protrusions 2 is 1 mm. The two ends of each side protrusion 2 are machined into semicircles with a radius of 0.25 mm, and the top end, furthest from the substrate, is ground into an end rounded surface 6 with a radius of 0.1 mm. A recessed groove 7 with a width of 0.5 mm and a depth of 0.2 mm is naturally formed between adjacent side protrusions 2. Multiple rectangular positioning holes of 0.6 mm by 1.0 mm are also punched into the polyimide substrate 1 according to JEDEC standards.

[0047] The production process begins by symmetrically pressing two layers of 18-micron-thick rolled copper foil 101 onto the upper and lower surfaces of the pre-formed side protrusions 2 of the polyimide substrate 1 in a vacuum hot press. The hot pressing parameters are set at 180 degrees Celsius, 3 kg / cm², and 120 seconds. During this process, the soft copper foil 101, under the influence of heat and force, completely conforms to the contour of the substrate, tightly wrapping each side protrusion 2 and sinking into the recessed grooves 7, thus forming grooves 4 on the copper foil 101 that mirror the microstructure of the substrate surface. This three-dimensional conformal covering process utilizes the three-dimensional contour of the side protrusions 2 to provide effective lateral mechanical constraint on the copper foil 101. Online visual inspection confirms that the lateral slippage of the copper foil 101 relative to the substrate is controlled within ±5 microns, completely eliminating the micro-wrinkle phenomenon commonly found in traditional processes.

[0048] The next step is a localized reinforcement bonding process. Using a dispensing device, Henkel's Loctite series epoxy resin insulating adhesive is precisely applied to the insulating surfaces 5 of the upper and lower copper foils 101 where permanent bonding is required. The dispensing location is strictly controlled by the program, concentrating 80% of the adhesive within the areas of each recessed groove 7. The adhesive fills and cures in the recessed grooves 7, forming a series of reinforced anchor points spaced one millimeter apart, while the copper foil 101 area on top of the side protrusions 2 remains largely unadhesive. This design concentrates the bonding force in the recessed grooves 7, which are less affected by shear forces and are protected by the sidewalls of the side protrusions 2. Peel strength tests show an interlayer bond strength of 1.5 Newtons per centimeter, approximately 60% higher than traditional full-plane coating processes.

[0049] Next, high-density interconnect processing is performed. Using an ultraviolet laser drilling machine, holes are drilled at the locations where vias are needed. Since each preset hole location on the polyimide substrate 1 has a pre-etched contact groove 3 with a depth of 30 micrometers, this groove provides an ideal incident and heat dissipation interface for the laser beam, making drilling into the polyimide substrate 1 smoother after penetrating the copper foil 101. The final processed via diameter is stable at 75 micrometers, with smooth, carbon-free hole walls, achieving a highly reliable vertical electrical connection between the upper and lower circuit layers.

[0050] Finally, functional modules are constructed on the copper foil 101 surface after pattern etching. The contact pads are arranged with six contacts according to ISO 78162 standards. A nickel underlayer and a 0.3-micron-thick gold plating layer are deposited sequentially through electroplating, and a nano-diamond coating is applied to the gold layer surface, giving the contacts a wear resistance life exceeding 300,000 cycles. The connector pads consist of seven copper-based connectors, bonded to the die using 25-micron-diameter gold wires. The average wire bond pull force test result is higher than 4 grams. The antenna layer uses a spiral coil etched from copper foil 101, with a linewidth of 0.1 millimeters and a spacing of 0.1 millimeters. The inductance is designed to be 16 microhenries, and it is flexibly connected to the chip using two 30-micron-diameter aluminum wires via wedge bonding technology.

[0051] The fabricated flexible circuit module performed excellently in dynamic bending tests simulating real-world use. Under bending conditions with a radius of three millimeters, after more than 200,000 repeated bends, no delamination of the copper foil 101 from the substrate was observed. In temperature cycling tests ranging from -25°C to 85°C, its electrical connectivity and mechanical integrity remained unchanged after 1,000 cycles. This structure has been successfully applied to automated production lines for financial IC card stripes with a monthly capacity of tens of millions of cards, improving the overall yield of the final product by 2.5%. Due to its superior bending resistance, the smart card easily passed over 100,000 insertion / removal and torsion life tests, fully meeting the extreme requirements of the financial payment industry for high reliability and ultra-long service life.

[0052] The working principle of this invention is as follows: Step 1: A 0.15mm thick polyimide film is used as the polyimide substrate 1, and its surface is coated with a nanoscale insulating layer. Multiple side protrusions 2 are linearly arrayed along both edges of the polyimide substrate 1 using a snap-fit ​​or integrated molding process. The two ends of the cross-section of the side protrusions 2 are semi-circular, and recessed grooves 7 are naturally formed between adjacent side protrusions. Rectangular positioning holes are also arrayed on both sides of the polyimide substrate 1 for precise positioning during the production process.

[0053] Step 2: The upper and lower layers of copper foil 101 are symmetrically wrapped around the upper and lower surfaces of the polyimide substrate 1 with the side protrusions 2 installed. During the hot-pressing process, the soft copper foil 101, under the action of pressure and temperature, tightly wraps around each side protrusion 2 and sinks into the recessed groove 7, thereby naturally forming a forming groove 4 that perfectly matches the contour of the substrate surface. This process achieves three-dimensional conformal coverage of the copper foil 101.

[0054] The three-dimensional contour of the side bump 2 forms a physical constraint on the copper foil 101 covering it in the horizontal direction. In subsequent production transfer or hot pressing processes, it can effectively suppress lateral slippage and local wrinkling of the copper foil 101 caused by stress or process fluctuations, providing a basic guarantee for achieving high-precision alignment of micron-level circuits.

[0055] Step 3: In the area where the upper and lower copper foils 101 need to be bonded, i.e. the insulating adhesive surface 5, the insulating adhesive is selectively and concentratedly applied to the recessed groove 7 area, rather than the entire plane.

[0056] The adhesive fills and cures within the recessed groove 7, firmly anchoring the upper and lower copper foils 101 together in this area. Since the recessed groove 7 is a relatively recessed area protected by the sidewalls of the side protrusions 2, the adhesive joint formed here can more effectively resist the shear stress and peel stress that cause interlayer separation.

[0057] When the load-bearing structure is subjected to bending stress, the surface bonding of traditional planar structures is prone to overall failure. However, in this structure, the stress mode is transformed into the side protrusions 2 providing mechanical support against compression and bending, preventing excessive deformation; The adhesive joints within the recessed groove 7 provide anti-delamination anchoring force. Together, these elements disperse interlaminar stress and direct it to stronger structural areas, significantly enhancing resistance to delamination.

[0058] Step 4: When the flexible circuit board is repeatedly bent during operation, on the inner side of the bend, two adjacent side protrusions 2 will move closer to each other due to the deformation of the substrate. The semi-circular end face design increases the contact area, allowing them to make smooth contact and form a series of micro-supports to jointly bear the compressive stress, preventing the copper foil 101 from wrinkling or being excessively squeezed at the bend.

[0059] The end round surface 6 at the top of the side protrusion 2 is in surface contact with the inner wall of the copper foil 101 rather than in line contact, which optimizes the stress distribution and avoids fatigue fracture of the copper foil 101 that may be caused by sharp edges.

[0060] On the curved outer side, the recessed groove 7 between the side protrusions 2 provides deformation space, allowing the material to stretch within a certain range, while the adhesive inside continues to act as an anchor, resisting peeling forces.

[0061] Step 5: The rectangular positioning hole array on both sides of the polyimide substrate 1, in conjunction with the vision recognition system or mechanical positioning pins of the automated production line, ensures the positional accuracy of the load-bearing structure throughout the entire process of cutting, bonding, drilling, and assembly.

[0062] The pre-formed contact arc grooves 3 on the polyimide substrate 1 provide a guiding and buffering structure at locations where laser drilling is required to form interlayer vias. This reduces the difficulty of laser drilling, helps to obtain micropores with smoother walls and more precise positioning, and improves the reliability of high-density interconnects.

[0063] On this support structure, contact pads, connecting pads, and FPC antenna coils conforming to ISO78162 standards can be further formed on the copper foil 101 through pattern etching, so as to realize the high integration of dual interface functions of smart cards and other products.

[0064] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flexible circuit board support structure for automated production, characterized in that, include: A polyimide substrate (1) is a flexible material with a thickness of 0.15 mm. The surface of the polyimide substrate (1) is coated with a nanoscale insulating layer. Two copper foils (101) are symmetrically distributed and cover the upper and lower sides of the polyimide substrate (1). Side protrusions (2) are linearly arrayed and snapped onto both sides of the polyimide substrate (1) for contact between the two side protrusions (2) that come closer together due to bending when the polyimide substrate (1) and the copper foil (101) are bent by shear force. The cross-sections at both ends of the side protrusions (2) are semi-circular to provide the contact area between the two side protrusions (2). A recessed groove (7) is formed between the two side protrusions (2).

2. The flexible circuit board support structure for automated production according to claim 1, characterized in that: The polyimide substrate (1) has multiple rectangular positioning holes arranged in an array on both sides for positioning during the production process.

3. The flexible circuit board support structure for automated production according to claim 2, characterized in that: Both the polyimide substrate (1) and the copper foil (101) covering its surface are formed with through holes by laser drilling.

4. The flexible circuit board support structure for automated production according to claim 3, characterized in that: The copper foil (101) surface is provided with a contact plate group, a connecting plate group and an antenna layer.

5. The flexible circuit board support structure for automated production according to claim 4, characterized in that: The contact pad assembly includes six gold-plated contacts arranged according to ISO78162 standard, and the contact surface is coated with nano-diamond. The back of the connector assembly has seven copper-based connectors, which are connected to the integrated circuit pins via die bonding wires. The antenna layer adopts an FPC structure and uses a copper-based etched antenna coil. The antenna coil and the chip are flexibly connected via wire bonding technology.

6. The flexible circuit board support structure for automated production according to claim 1, characterized in that: The copper foil (101) forms a groove (4) when it covers the side protrusion (2) and the recess (7).

7. The flexible circuit board support structure for automated production according to claim 6, characterized in that: The joint between the two copper foils (101) is provided as an insulating adhesive surface (5). The two different insulating adhesive surfaces (5) are bonded and fixed together by insulating adhesive, and most of the bonding and fixing points between the two insulating adhesive surfaces (5) are located between the recessed grooves (7).

8. The flexible circuit board support structure for automated production according to claim 1, characterized in that: The end of the side protrusion (2) away from the polyimide substrate (1) is set as an end round surface (6) to increase the contact area between the end of the side protrusion (2) and the copper foil (101).

9. The flexible circuit board support structure for automated production according to claim 3, characterized in that: The polyimide substrate (1) has contact arc grooves (3) on the side near the copper foil (101) to reduce the difficulty of opening the through holes.

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