Flexible high-voltage pulse generator based on micro pulse transformer network

Abstract

The invention discloses a flexible high-voltage pulse generator based on a micro pulse transformer network, belongs to the technical field of high-voltage pulse power supplies, and is suitable for wearable and flexible electronic systems. The generator takes a rigid-flexible coupling composite substrate as a carrier, a plurality of micro pulse transformers are integrated in a device bearing area of the composite substrate, and high-voltage pulse output is realized by constructing a pulse transformer network; aiming at the problems of limited magnetic performance, insufficient insulation distance and reduced output capability of a micro pulse transformer under the conditions of flexibility and low-height integration, the invention adopts a transformer network collaborative boosting mode, and realizes high-voltage output on the premise of not obviously increasing the size of a single device. By means of the structure, miniaturized high-voltage pulse generation can be achieved on the flexible substrate with the limited thickness, and good mechanical flexibility, electrical reliability and integration adaptability are achieved.

Description

Technical Field

[0001] This invention relates to the field of high-voltage pulse power supply technology, specifically to a flexible high-voltage pulse generator based on a micro-pulse transformer network. Background Technology

[0002] Flexible plasma technology, as an emerging interdisciplinary research field, has shown significant potential in medical treatment, wound repair, and sterilization. With the rapid development of flexible electronics and wearable devices, electronic systems are gradually evolving from rigid planes towards lightweight, flexible, and adhesive designs. Against this backdrop, low-temperature plasma based on dielectric barrier discharge, in particular, is considered one of the core technologies for future wearable medical and bioelectronic systems because it can generate non-equilibrium plasma at ambient pressure, enabling gentle, non-contact application to biological tissues. However, the key to achieving flexible plasma discharge across the entire system lies in its power supply system, which needs to strike a balance between miniaturization, flexibility, and safety. This has become the main bottleneck currently restricting the practical application of flexible plasma devices.

[0003] Traditional high-voltage pulse power supplies struggle to achieve high voltage levels, high rise time performance, and long-term stable operation on flexible substrates. Existing high-voltage pulse power supplies typically employ multi-stage Marx generators or large step-up transformers, resulting in large size, heavy weight, and high device stacking height, which fails to meet the requirements of flexible electronic devices such as wearable plasma medical devices for thinness and portability. Furthermore, directly integrating high-voltage power supplies onto composite substrates presents three major challenges: first, aging and performance degradation of the flexible substrate due to heat generated by high-voltage devices; second, easy detachment of solder joints and breakage of wires when the substrate is bent; and third, difficulty in ensuring high-voltage insulation within confined spaces.

[0004] Meanwhile, traditional high-voltage pulse power supplies mostly employ rigid magnetic core transformers and discrete circuit structures, resulting in large size, heavy weight, and fixed form, making them unsuitable for wearable environments. Furthermore, flexibility significantly alters the internal electric field distribution, heat accumulation, and mechanical stress of the system, leading to problems such as decreased insulation performance, partial discharge, and conductor fatigue. Therefore, establishing a pulse power supply system with high output capability and flexible adaptability is of great significance.

[0005] Against this backdrop, to overcome existing shortcomings, this invention, starting from the wearable requirements of flexible plasma loads, proposes a flexible high-voltage pulse power supply scheme based on a micro-pulse transformer as its core. The flexible high-voltage pulse generator uses a micro-pulse transformer as the core boost unit for high-voltage output. High-voltage pulse output is achieved through the collaborative operation of multiple micro-pulse transformers. These micro-pulse transformers are integrated within the device-bearing area of ​​a rigid-flexible coupled composite substrate. Due to constraints on the thickness, bendability, and reliability of the composite substrate, a single micro-pulse transformer faces technical difficulties under integrated conditions, including limitations on core height, number of winding turns, and insulation distance, leading to a decrease in boost capacity and pulse performance. To overcome these integration difficulties, the multiple micro-pulse transformers are constructed into a pulse transformer network. Through networked collaborative boosting, high-voltage pulse output is achieved without significantly increasing the size of individual devices, thus enabling the flexible high-voltage pulse generator to achieve high-voltage output functionality on the composite substrate. Theoretically, this structure can reduce the primary-side voltage stress of a single transformer while maintaining the output voltage level, achieving modular and thin-layer design suitable for embedding in composite substrates. This invention aims to overcome the technical bottleneck of traditional rigid power supplies being unable to stably boost voltage and operate safely in flexible wearable environments. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the prior art. This invention provides a flexible high-voltage pulse generator based on a micro-pulse transformer network. This generator solves mechanical and heat dissipation problems through a "rigid-flexible coupling" structural design and achieves extreme miniaturization of the circuit through a "hybrid cascaded topology", thereby stably outputting kilovolt-level high-voltage pulses in an ultra-thin and flexible form.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A flexible high-voltage pulse generator based on a micro-pulse transformer network is disclosed. The generator employs a structure combining single-stage Marx pulse generation with a distributed IPOS pulse transformer network, integrated onto a rigid-flexible coupled composite substrate to achieve high-voltage pulse output under flexible conditions and system miniaturization. The generator includes:

[0009] The rigid-flexible coupling composite substrate is not a single flexible board, but consists of a continuous flexible dielectric layer and multiple discontinuous rigid reinforcing layers bonded to specific areas of the flexible dielectric layer by an adhesive process. The rigid reinforcing layers are defined as device bearing areas, used to install core components and provide mechanical support. The flexible dielectric layers without rigid reinforcing layers are defined as flexible deformation areas, used to bear bending stress.

[0010] A DC boost module is located in the device's carrying area as a pre-regulator unit, configured to convert the input low-voltage DC power into a DC voltage of a preset voltage level, providing a stable energy reference for the subsequent stage.

[0011] A single-stage Marx pulse modulation module is disposed in the device carrier area, and its input terminal is electrically connected to the output terminal of the DC boost module. The single-stage Marx pulse modulation module does not contain a multi-stage voltage multiplier structure, but only includes a single set of energy storage capacitors and switching devices. Only a single set of energy storage capacitors and a single-stage switching device are needed to complete the pulse switching. It is configured to modulate the DC voltage into a primary pulse voltage, and the amplitude of the primary pulse voltage output is equal to the DC voltage.

[0012] An IPOS pulse transformer network comprises N high-turn-ratio, low-profile E-core miniature pulse transformers, wherein the number of miniature pulse transformers is... Furthermore, using surface mount technology, the components are respectively disposed on multiple discontinuous rigid reinforcement layers of the rigid-flexible coupling composite substrate. The primary windings are connected in parallel and electrically connected to the output terminal of the single-stage Marx pulse modulation module. The secondary windings are connected in series to form a high-voltage output terminal, which is used to boost and superimpose the primary pulse voltage to output a high-voltage pulse voltage. The secondary series connection line in the IPOS topology is located in the flexible deformation region. The magnetic core of the micro pulse transformer is made of low-profile E-type or planar high-frequency power ferrite material, limiting the height of a single device to no more than 5mm. Utilizing its characteristics of short magnetic circuit, low leakage flux, and low loss, it achieves fast magnetic flux response under high-frequency pulse conditions, and meets the magnetic flux requirement by increasing the cross-sectional area of ​​the magnetic core rather than the height. Each micro pulse transformer is configured with a high turns ratio of 1:20 to 1:50. Its primary winding adopts a low-turns design, and high permeability magnetic core material is used to ensure sufficient excitation inductance under low-turns conditions.

[0013] A control unit is located in the device carrying area, and its output terminal is connected to the control terminal of the single-stage Marx pulse modulation module through a signal line arranged in the flexible deformation area, for providing PWM timing control signals to the single-stage Marx pulse modulation module.

[0014] The drive module, located in the device carrier area, has its input connected to the output of the control unit and its output connected to the switching device in the single-stage Marx pulse modulation module. This module possesses upper and lower bridge arm bootstrapping drive capabilities and is configured to receive PWM signals and generate high-frequency alternating positive and negative drive signals to provide trigger waveforms for subsequent switching devices. To suppress high... To mitigate the interference, the driver-level wiring adopts a short-loop layout, and decoupling capacitors are deployed near the chip.

[0015] An auxiliary power supply module is located in the device's carrying area. Its input terminal is connected to an external power supply, and its output terminal is connected to the control unit and the drive module, respectively, to provide them with a stable low-voltage operating power supply.

[0016] Along the longitudinal extension direction of the rigid-flexible coupling composite substrate, the control unit, DC boost module, and IPOS pulse transformer network are distributed sequentially according to potential levels, implementing a strict high- and low-voltage physical partitioning layout, dividing the circuit into three independent electromagnetic functional areas: a low-voltage control area, a power conversion area, and a high-voltage output area. The structural arrangement of the rigid-flexible coupling composite substrate is as follows: the components of the DC boost module, single-stage Marx pulse modulation module, and IPOS pulse transformer network are all soldered onto the conductive pads corresponding to the rigid reinforcement layer, avoiding direct bending torque on the components. The cascaded electrical connection lines between the modules are arranged in the flexible deformation area, and the wires connecting the modules adopt a serpentine routing process, utilizing geometric redundancy to release tensile stress and prevent open circuits.

[0017] Furthermore, the rigid-flexible coupling composite substrate exhibits a specific lamination process structure in the vertical direction, which includes, from top to bottom: a surface immersion gold conductive layer, a polyimide dielectric layer, a bottom immersion gold conductive layer, and a local reinforcement layer.

[0018] Furthermore, the top-layer gold conductive layer retains a continuously laid copper foil reference ground plane in the device bearing area corresponding to the low-voltage part of the transformer primary side. The continuously laid copper foil covers the area of ​​the DC boost module, the single-stage Marx pulse modulation module, the control module, the drive module, the auxiliary power module, and the area where the traces of the above modules are located. The copper foil coverage ratio is not less than 50% of the overall device bearing area. The thickness of the reinforcing layer is 0.2mm-0.5mm, and its edges are chamfered to prevent puncturing the flexible cover film.

[0019] Furthermore, through the laminated structure, the rigid-flexible coupling composite substrate is divided into a rigid device bearing area with a four-layer structure including a reinforcing layer and a flexible deformation area with only the first three layers and no reinforcing layer.

[0020] Furthermore, the lamination process is achieved through the following material selection and process steps:

[0021] Step S1: Material selection for the flexible dielectric layer:

[0022] The polyimide dielectric layer and the conductive layer substrate above and below it are made of high temperature resistant and corona resistant PI copper clad laminate as raw material. The PI is adhesive-free polyimide, which eliminates the high thermal resistance and easy aging problems caused by traditional adhesive layers by utilizing the characteristics of adhesive-free substrate.

[0023] Step S2, Treatment of the conductive layer:

[0024] The copper foil on the surface and bottom of the raw material is etched to form a circuit pattern; a chemical immersion gold surface treatment process is applied to the conductive pads on the device carrier area to form a surface and bottom immersion gold conductive layer; the bottom immersion gold conductive layer retains a large area of ​​complete copper foil in the rigid device carrier area as a common ground plane and auxiliary heat dissipation layer for the circuit; the conductive pads on the surface of the device carrier area are treated with a chemical immersion gold surface treatment process.

[0025] Step S3, reinforcement layer bonding:

[0026] The local reinforcement layer is made of FR4 fiberglass board or steel sheet and is attached to the back of the device bearing area by hot pressing or bonding process; the reinforcement layer covers the projection area of ​​DC boost, Marx modulation and transformer network, and serves as a mechanical support platform and heat sink for the components; the power devices on the front are thermally connected to the bottom copper foil.

[0027] Furthermore, the parameters of the DC boost module and the single-stage Marx pulse modulation module are matched as follows: the DC boost module is configured to boost the input voltage to the DC bus voltage; the module integrates a current detection loop, is configured with a feedback resistor voltage divider network for adjusting the output voltage, and suppresses the start-up impact through soft start and overcurrent limiting functions.

[0028] Furthermore, the energy storage capacitor in the single-stage Marx pulse modulation module is a surface-mount high-voltage multilayer ceramic capacitor, and the switching device is a MOSFET including a fast-charging diode. Its working logic is as follows: when the switch is turned on, the DC boost module charges the energy storage capacitor through the fast-charging diode; when the drive signal is switched, the switch quickly connects the energy storage capacitor in series to the primary side of the transformer, so that the primary side obtains a pulse voltage with instantaneous amplitude increase.

[0029] Furthermore, the single-stage Marx pulse modulation module utilizes the DC bus voltage and requires only a single energy storage capacitor and a single-stage switching device to complete the pulse switching, avoiding the stacking of capacitor arrays and complex isolation drive circuits in multi-stage Marx circuits.

[0030] Furthermore, the miniaturized assembly process of the IPOS pulse transformer network involves surface mount technology (SMT) to solder the miniature pulse transformer onto the rigid device carrier area. The spacing between adjacent high-voltage traces in the secondary-side series connection lines of the IPOS topology is set by calculating the dielectric breakdown field strength, and the copper plating around the traces is removed to ensure that no dielectric breakdown or creepage flashover occurs between high-voltage nodes when the substrate bends, causing local electric field distortion. The minimum creepage distance between adjacent high-voltage traces is determined by considering the surface flashover field strength characteristics of the PI dielectric. Based on the following formula:

[0031]

[0032] in, For safety reasons, This represents the peak value of the pulse voltage across the secondary side of a single transformer. The threshold value for surface flashover field strength in flexible PI dielectric materials.

[0033] Compared with the prior art, the present invention has the following significant advantages:

[0034] (1) This invention provides a flexible high-voltage pulse generator based on a micro pulse transformer network, which realizes the extreme miniaturization and thinning of the high-voltage power supply: This invention improves the reference voltage through a "DC boost module", so that a "single-stage Marx" can meet the driving requirements, eliminating the need for multi-stage capacitor stacking; combined with the distributed layout of the "IPOS transformer network", the height of a single high-voltage transformer is reduced to zero; this topology combination enables the power supply to be integrated on a substrate with a thickness of only a few millimeters, and the individual device height does not exceed 5mm.

[0035] (2) This invention provides a flexible high-voltage pulse generator based on a micro pulse transformer network, which solves the mechanical reliability problem on the composite substrate: through the rigid-flexible coupling design of the "device carrying area" and the "flexible deformation area"; the serpentine wiring process further ensures the reliability of the electrical connection under repeated bending and torsion conditions.

[0036] (3) This invention provides a flexible high-voltage pulse generator based on a micro pulse transformer network, which solves the problems of improving insulation and heat dissipation performance under high frequency and high voltage: the use of adhesive-free PI material avoids the aging and failure of traditional adhesives under high voltage; the rigid reinforcement layer combined with the bottom gold copper foil design effectively disperses the hot spots of power devices; the edge chamfering treatment and reasonable creepage distance design ensure the beneficial effect of insulation safety of the system during dynamic deformation. Attached Figure Description

[0037] Figure 1 This is a logical architecture diagram of the technical solution of an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0039] Figure 3 This is the overall circuit diagram of an embodiment of the present invention;

[0040] Figure 4 This is a peripheral circuit diagram based on a boost converter chip according to an embodiment of the present invention;

[0041] Figure 5This is a first-level Marx circuit diagram according to an embodiment of the present invention;

[0042] Figure 6 This is a driving circuit diagram based on a half-bridge chip according to an embodiment of the present invention;

[0043] Figure 7 This is a circuit diagram of the PWM module according to an embodiment of the present invention;

[0044] Figure 8 This is a power supply circuit diagram of the power module according to an embodiment of the present invention;

[0045] Figure 9 This is the high-voltage pulse output voltage waveform of an embodiment of the present invention;

[0046] Figure 10 This is a schematic diagram of the PCB top and bottom layer assembly according to an embodiment of the present invention. Detailed Implementation

[0047] 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.

[0048] A flexible high-voltage pulse generator based on a micro-pulse transformer network is disclosed. The generator employs a structure combining single-stage Marx pulse generation with a distributed IPOS pulse transformer network, integrated onto a rigid-flexible coupled composite substrate to achieve high-voltage pulse output under flexible conditions and system miniaturization. The generator includes:

[0049] The rigid-flexible coupling composite substrate is not a single flexible board, but consists of a continuous flexible dielectric layer and multiple discontinuous rigid reinforcing layers bonded to specific areas of the flexible dielectric layer by an adhesive process. The rigid reinforcing layers are defined as device bearing areas, used to install core components and provide mechanical support. The flexible dielectric layers without rigid reinforcing layers are defined as flexible deformation areas, used to bear bending stress.

[0050] A DC boost module is located in the device's carrying area as a pre-regulator unit, configured to convert the input low-voltage DC power into a DC voltage of a preset voltage level, providing a stable energy reference for the subsequent stage.

[0051] A single-stage Marx pulse modulation module is disposed in the device carrier area, and its input terminal is electrically connected to the output terminal of the DC boost module. The single-stage Marx pulse modulation module does not contain a multi-stage voltage multiplier structure, but only includes a single set of energy storage capacitors and switching devices. Only a single set of energy storage capacitors and a single-stage switching device are needed to complete the pulse switching. It is configured to modulate the DC voltage into a primary pulse voltage, and the amplitude of the primary pulse voltage output is equal to the DC voltage.

[0052] IPOS pulse transformer network, including A high turns ratio, low profile E-type magnetic core miniature pulse transformer, wherein the number of miniature pulse transformers Furthermore, using surface mount technology, the components are respectively disposed on multiple discontinuous rigid reinforcement layers of the rigid-flexible coupling composite substrate. The primary windings are connected in parallel and electrically connected to the output terminal of the single-stage Marx pulse modulation module. The secondary windings are connected in series to form a high-voltage output terminal, which is used to boost and superimpose the primary pulse voltage to output a high-voltage pulse voltage. The secondary series connection line in the IPOS topology is located in the flexible deformation region. The magnetic core of the micro pulse transformer is made of low-profile E-type or planar high-frequency power ferrite material, limiting the height of a single device to no more than 5mm. Utilizing its characteristics of short magnetic circuit, low leakage flux, and low loss, it achieves fast magnetic flux response under high-frequency pulse conditions, and meets the magnetic flux requirement by increasing the cross-sectional area of ​​the magnetic core rather than the height. Each micro pulse transformer is configured with a high turns ratio of 1:20 to 1:50. Its primary winding adopts a low-turns design, and high permeability magnetic core material is used to ensure sufficient excitation inductance under low-turns conditions.

[0053] A control unit is located in the device carrying area, and its output terminal is connected to the control terminal of the single-stage Marx pulse modulation module through a signal line arranged in the flexible deformation area, for providing PWM timing control signals to the single-stage Marx pulse modulation module.

[0054] The drive module, located in the device carrier area, has its input connected to the output of the control unit and its output connected to the switching device in the single-stage Marx pulse modulation module. This module possesses upper and lower bridge arm bootstrapping drive capabilities and is configured to receive PWM signals and generate high-frequency alternating positive and negative drive signals to provide trigger waveforms for subsequent switching devices. To suppress high... To mitigate the interference, the driver-level wiring adopts a short-loop layout, and decoupling capacitors are deployed near the chip.

[0055] An auxiliary power supply module is located in the device's carrying area. Its input terminal is connected to an external power supply, and its output terminal is connected to the control unit and the drive module, respectively, to provide them with a stable low-voltage operating power supply.

[0056] Along the longitudinal extension direction of the rigid-flexible coupling composite substrate, the control unit, DC boost module, and IPOS pulse transformer network are distributed sequentially according to potential levels, implementing a strict high- and low-voltage physical partitioning layout, dividing the circuit into three independent electromagnetic functional areas: a low-voltage control area, a power conversion area, and a high-voltage output area. The structural arrangement of the rigid-flexible coupling composite substrate is as follows: the components of the DC boost module, single-stage Marx pulse modulation module, and IPOS pulse transformer network are all soldered onto the conductive pads corresponding to the rigid reinforcement layer, avoiding direct bending torque on the components. The cascaded electrical connection lines between the modules are arranged in the flexible deformation area, and the wires connecting the modules adopt a serpentine routing process, utilizing geometric redundancy to release tensile stress and prevent open circuits.

[0057] Furthermore, the rigid-flexible coupling composite substrate exhibits a specific lamination process structure in the vertical direction, which includes, from top to bottom: a surface immersion gold conductive layer, a polyimide dielectric layer, a bottom immersion gold conductive layer, and a local reinforcement layer.

[0058] Furthermore, the top-layer gold conductive layer retains a continuously laid copper foil reference ground plane in the device bearing area corresponding to the low-voltage part of the transformer primary side. The continuously laid copper foil covers the area of ​​the DC boost module, the single-stage Marx pulse modulation module, the control module, the drive module, the auxiliary power module, and the area where the traces of the above modules are located. The copper foil coverage ratio is not less than 50% of the overall device bearing area. The thickness of the reinforcing layer is 0.2mm-0.5mm, and its edges are chamfered to prevent puncturing the flexible cover film.

[0059] Furthermore, through the laminated structure, the rigid-flexible coupling composite substrate is divided into a rigid device bearing area with a four-layer structure including a reinforcing layer and a flexible deformation area with only the first three layers and no reinforcing layer.

[0060] Furthermore, the lamination process is achieved through the following material selection and process steps:

[0061] Step S1: Material selection for the flexible dielectric layer:

[0062] The polyimide dielectric layer and the conductive layer substrate above and below it are made of high temperature resistant and corona resistant PI copper clad laminate as raw material. The PI is adhesive-free polyimide, which eliminates the high thermal resistance and easy aging problems caused by traditional adhesive layers by utilizing the characteristics of adhesive-free substrate.

[0063] Step S2, Treatment of the conductive layer:

[0064] The copper foil on the surface and bottom of the raw material is etched to form a circuit pattern; a chemical immersion gold surface treatment process is applied to the conductive pads on the device carrier area to form a surface and bottom immersion gold conductive layer; the bottom immersion gold conductive layer retains a large area of ​​complete copper foil in the rigid device carrier area as a common ground plane and auxiliary heat dissipation layer for the circuit; the conductive pads on the surface of the device carrier area are treated with a chemical immersion gold surface treatment process.

[0065] Step S3, reinforcement layer bonding:

[0066] The local reinforcement layer is made of FR4 fiberglass board or steel sheet and is attached to the back of the device bearing area by hot pressing or bonding process; the reinforcement layer covers the projection area of ​​DC boost, Marx modulation and transformer network, and serves as a mechanical support platform and heat sink for the components; the power devices on the front are thermally connected to the bottom copper foil.

[0067] Furthermore, the parameters of the DC boost module and the single-stage Marx pulse modulation module are matched as follows: the DC boost module is configured to boost the input voltage to the DC bus voltage; the module integrates a current detection loop, is configured with a feedback resistor voltage divider network for adjusting the output voltage, and suppresses the start-up impact through soft start and overcurrent limiting functions.

[0068] Furthermore, the energy storage capacitor in the single-stage Marx pulse modulation module is a surface-mount high-voltage multilayer ceramic capacitor, and the switching device is a MOSFET including a fast-charging diode. Its working logic is as follows: when the switch is turned on, the DC boost module charges the energy storage capacitor through the fast-charging diode; when the drive signal is switched, the switch quickly connects the energy storage capacitor in series to the primary side of the transformer, so that the primary side obtains a pulse voltage with instantaneous amplitude increase.

[0069] Furthermore, the single-stage Marx pulse modulation module utilizes the DC bus voltage and requires only a single energy storage capacitor and a single-stage switching device to complete the pulse switching, avoiding the stacking of capacitor arrays and complex isolation drive circuits in multi-stage Marx circuits.

[0070] Furthermore, the miniaturized assembly process of the IPOS pulse transformer network involves surface mount technology (SMT) to solder the miniature pulse transformer onto the rigid device carrier area. The spacing between adjacent high-voltage traces in the secondary-side series connection lines of the IPOS topology is set by calculating the dielectric breakdown field strength, and the copper plating around the traces is removed to ensure that no dielectric breakdown or creepage flashover occurs between high-voltage nodes when the substrate bends, causing local electric field distortion. The minimum creepage distance between adjacent high-voltage traces is determined by considering the surface flashover field strength characteristics of the PI dielectric. Based on the following formula:

[0071]

[0072] in, For safety reasons, This represents the peak value of the pulse voltage across the secondary side of a single transformer. The threshold value for surface flashover field strength in flexible PI dielectric materials.

[0073] To further illustrate the technical solution of the present invention, the following embodiments are used for further explanation:

[0074] This embodiment provides a miniaturized flexible high-voltage pulse generator based on a rigid-flexible coupling composite substrate. Designed specifically for wearable plasma medical devices, this generator has an overall physical size of only 62mm × 25mm × 4.5mm, achieving kilovolt-level high-voltage pulse output while meeting the requirements for flexible bending.

[0075] A flexible high-voltage pulse generator based on a micro-pulse transformer network, the generator comprising:

[0076] The flexible dielectric layer is made of 50μm thick adhesive-free polyimide (PI) double-sided copper-clad laminate. Compared with adhesive-based substrates, adhesive-free PI has higher heat resistance and high-frequency dielectric stability, preventing dielectric aging under high-voltage pulses.

[0077] Furthermore, in the core areas of the circuit layout (including the Boost chip, Marx switch, and the bottom of the transformer), a 0.3mm thick FR4 fiberglass board is bonded using a hot-pressing process. These FR4 areas are defined as device support areas, providing mechanical flatness for the fragile ceramic capacitors and transformers and blocking the transmission of bending stress. In the connection areas between the rigid islands, no reinforcing layer is provided, preserving the original flexibility of the PI substrate, and these are defined as flexible deformation areas. This area is used to withstand the dynamic bending of the system during wear.

[0078] Furthermore, the conductive layer on the substrate surface is a 20μm electrolytic copper foil, with a chemical immersion gold treatment to reduce high-frequency skin effect losses. On the back conductive layer, a large, intact immersion gold copper foil layer is retained as a common ground plane and heat sink. The power devices on the front side (such as MOSFETs and transformers) are thermally connected to the underlying copper foil, thereby rapidly dissipating heat laterally and preventing localized overheating that could damage the PI substrate. A schematic diagram of the overall structure is shown below. Figure 2 As shown.

[0079] In terms of miniaturization of circuit topology, this invention abandons the bulky traditional multi-stage Marx structure and adopts a pulse forming circuit with DC boost, single-stage modulation, and an IPOS network. The overall circuit diagram is as follows. Figure 3 As shown.

[0080] The DC-DC boost module uses the high-efficiency XL6007 boost control chip. This chip integrates a 400kHz switching device and current sensing loop, enabling stable voltage boosting with relatively small magnetic components. The module consists of an input filter, inductor, XL6007 switching transistor, Schottky diode, and output capacitor. The XL6007 drives the power switch via an internal oscillator to control the inductor's energy storage and release process, thereby boosting the 5–12 V input voltage to 50 V to provide DC voltage for the subsequent Marx circuit. The boost stage incorporates a feedback resistor voltage divider network to regulate the output voltage and suppresses startup surges through soft-start and overcurrent limiting functions. The DC-DC boost module circuit diagram is shown below. Figure 4 As shown.

[0081] To minimize the PCB footprint, this embodiment abandons the multi-level Marx structure and adopts a single-level topology, such as... Figure 5 As shown in the diagram, the circuit uses an N-channel MOSFET (NCEP02T10D) as the high-speed switching device. This device has low on-resistance and short reverse recovery time, effectively reducing losses during pulse discharge. In this embodiment, the first-stage Marx uses a single-stage structure, including a storage capacitor, a fast-charging diode, and a switching circuit composed of the NCEP02T10D. When the switch is on, the output of the preceding Boost stage charges the storage capacitor; when the drive signal switches, the switch quickly connects the storage capacitor in series to the primary side of the transformer, enabling the primary side to obtain a pulse voltage with instantaneous amplitude boost. The advantages of using a single-stage Marx are its simple structure, low loss, and ability to achieve significant pulse enhancement with fewer components, making it very suitable for space-constrained applications on composite substrates.

[0082] The driver module uses the EG3013 half-bridge driver chip, which has the bootstrap driving capability of both the upper and lower bridge arms and is suitable for driving medium-power MOSFETs. The driver circuit is as follows: Figure 6 As shown. In this embodiment, the EG3013 is used to generate a high-frequency alternating positive and negative drive signal to provide a trigger waveform for the subsequent first-stage Marx switch. The input side of the EG3013 is provided with a PWM signal by the controller, and automatic dead-time adjustment can prevent bridge arm cross-conduction. Its output side drives the MOSFET gates required by the subsequent pulse conversion network, enabling the system to operate stably in a frequency range of tens to hundreds of kHz. To suppress interference caused by high dv / dt, the driver stage wiring adopts a short-loop layout, and decoupling capacitors are deployed near the chip to improve drive stability.

[0083] The control module uses an STC8G1K08A microcontroller as the core controller of the system. The control module circuit is as follows: Figure 7As shown. The STC8G1K08A boasts high processing speed, and its I / O timing can be precisely controlled at nanosecond-level drive edges, ensuring consistency in pulse output shape and width. To ensure stable power supply for the microcontroller, the system is equipped with an AMS1117 linear regulator to stabilize the auxiliary voltage to 5V, providing reliable power to the STC controller and driver stage. The power supply circuit is as follows. Figure 8 As shown.

[0084] This pulse generator uses TTRN-052S miniature pulse transformers to form a high-voltage output network. The internal magnetic core of this type of device is an E-type ferrite structure, which has a short magnetic circuit, low leakage flux, and low loss, facilitating rapid flux response under high-frequency pulse conditions. The E-type magnetic core itself has the advantages of compact structure and high winding window utilization, significantly reducing the overall size of a single transformer and providing conditions for dense arrangement on a composite substrate. This embodiment uses three TTRN-052S miniature pulse transformers to form an IPOS network. These transformers use low-profile E-type magnetic cores, with a single unit height of only 4mm. In terms of circuit connection, the primary windings of the three transformers are connected in parallel to effectively reduce the primary inductance and increase the current rise rate, while the secondary windings are connected in series. The turns ratio of a single transformer is 1:20. When a 50V pulse is input to the primary side, the three transformers, when connected in series, can output a high-voltage pulse of approximately 3.6kV. The output voltage waveform is as follows: Figure 9 As shown.

[0085] Regarding the layout and interconnect process coordination, the PCB top and bottom layer assembly diagrams are as follows: Figure 10 As shown, the component layout on the PCB strictly adheres to the principle of rigid-flexible coupling. The miniature pulse transformer network is positioned close to the MARX switch to minimize the high-voltage pulse transmission path. A reasonable spacing isolation design reduces coupling interference between the high-voltage and control low-voltage areas, ensuring excellent electrical performance even under flexible bending and dynamic wearable conditions. Three miniature transformers are linearly spaced along the width of the substrate, each with independent FR4 reinforcement underneath, and a 5mm flexible deformation zone is left between them. In the flexible deformation zone connecting the secondary sides of each transformer, the high-voltage conductors employ an S-shaped meandering routing structure. When the substrate bends or twists, the S-shaped routing releases tensile stress through in-plane geometric deformation, preventing copper foil breakage. Simultaneously, the creepage distance of the high-voltage conductors in the flexible deformation zone was rigorously calculated and parameterized. Based on the output voltage of approximately 1.2kV on the secondary side of a single transformer and the maximum potential difference of 3.6kV after series connection, combined with the surface flashover characteristics of PI material, the minimum spacing between adjacent high-voltage nodes was set. Calculate and set the safety factor according to the formula. With a voltage rating of 1.5, the flashover field strength on the PI surface is approximately 0.5 kV / mm. In actual design, the minimum net spacing of the secondary side series traces is controlled to be above 3.6 mm, and the copper pour around the traces is removed to ensure insulation safety under dynamic bending.

[0086] The overall layout is clear, compact, and fully functional, taking into account both high-voltage output capability and the mechanical adaptability of the flexible platform, enabling this miniaturized circuit to meet the integration requirements of wearable plasma devices.

[0087] Those skilled in the art should understand that, unless otherwise specified, the meanings of the technical and scientific terms used herein are consistent with the general understanding of the relevant technical field. Furthermore, terms defined in general dictionaries should be understood in the context of the technical background in this field and should not be interpreted in an overly idealized or formalistic manner divorced from practical application scenarios.

[0088] The above embodiments have described in detail the main concept, technical solution, and technical effects of the present invention. It should be noted that the above content is merely illustrative and not intended to limit the scope of protection of the present invention. Any equivalent modifications, substitutions, or optimizations based on the present invention without departing from its core principles are within the scope of the present invention.

Claims

1. A flexible high-voltage pulse generator based on a micro-pulse transformer network, characterized in that, The generator employs a structure combining single-stage Marx pulse generation with a distributed IPOS pulse transformer network, integrated onto a rigid-flexible coupling composite substrate to achieve high-voltage pulse output under flexible conditions and system miniaturization. The generator includes: The rigid-flexible coupling composite substrate is not a single flexible board, but consists of a continuous flexible dielectric layer and multiple discontinuous rigid reinforcing layers bonded to specific areas of the flexible dielectric layer by an adhesive process. The rigid reinforcing layers are defined as device bearing areas, used to install core components and provide mechanical support. The flexible dielectric layers without rigid reinforcing layers are defined as flexible deformation areas, used to bear bending stress. A DC boost module is located in the device's carrying area as a pre-regulator unit, configured to convert the input low-voltage DC power into a DC voltage of a preset voltage level, providing a stable energy reference for the subsequent stage. A single-stage Marx pulse modulation module is disposed in the device carrier area, and its input terminal is electrically connected to the output terminal of the DC boost module. The single-stage Marx pulse modulation module does not contain a multi-stage voltage multiplier structure, but only includes a single set of energy storage capacitors and switching devices. Only a single set of energy storage capacitors and a single-stage switching device are needed to complete the pulse switching. It is configured to modulate the DC voltage into a primary pulse voltage, and the amplitude of the primary pulse voltage output is equal to the DC voltage. IPOS pulse transformer network, including A high turns ratio, low profile E-type magnetic core miniature pulse transformer, wherein the number of miniature pulse transformers Furthermore, using surface mount technology, the components are respectively disposed on multiple discontinuous rigid reinforcement layers of the rigid-flexible coupling composite substrate. Their primary windings are connected in parallel and electrically connected to the output terminal of the single-stage Marx pulse modulation module. Their secondary windings are connected in series to form a high-voltage output terminal, used to boost and superimpose the primary pulse voltage to output a high-voltage pulse voltage. The secondary series connection line in the IPOS topology is located in the flexible deformation region. The core of the micro-pulse transformer is made of low-profile E-type or planar high-frequency power ferrite material, limiting the height of a single device to no more than 5mm. Utilizing its short magnetic circuit, low leakage flux, and low loss characteristics, it achieves rapid magnetic flux response under high-frequency pulse conditions, and meets the magnetic flux requirement by increasing the core cross-sectional area rather than the height. Each micro-pulse transformer is configured with a high turns ratio of 1:20 to 1:

50. Its primary winding adopts a low number of turns design and uses a high permeability magnetic core material to ensure sufficient excitation inductance under the condition of low number of turns; A control unit is located in the device carrying area, and its output terminal is connected to the control terminal of the single-stage Marx pulse modulation module through a signal line arranged in the flexible deformation area, for providing PWM timing control signals to the single-stage Marx pulse modulation module. The drive module, located in the device carrier area, has its input connected to the output of the control unit and its output connected to the switching device in the single-stage Marx pulse modulation module. This module possesses upper and lower bridge arm bootstrapping drive capabilities and is configured to receive PWM signals and generate high-frequency alternating positive and negative drive signals to provide trigger waveforms for subsequent switching devices. To suppress high... To mitigate the interference, the driver-level wiring adopts a short-loop layout, and decoupling capacitors are deployed near the chip. An auxiliary power supply module is located in the device's carrying area. Its input terminal is connected to an external power supply, and its output terminal is connected to the control unit and the drive module, respectively, to provide them with a stable low-voltage operating power supply. Along the longitudinal extension direction of the rigid-flexible coupling composite substrate, the control unit, DC boost module, and IPOS pulse transformer network are distributed sequentially according to potential levels, implementing a strict high- and low-voltage physical partitioning layout, dividing the circuit into three independent electromagnetic functional areas: a low-voltage control area, a power conversion area, and a high-voltage output area. The structural arrangement of the rigid-flexible coupling composite substrate is as follows: the components of the DC boost module, single-stage Marx pulse modulation module, and IPOS pulse transformer network are all soldered onto the conductive pads corresponding to the rigid reinforcement layer, avoiding direct bending torque on the components. The cascaded electrical connection lines between the modules are arranged in the flexible deformation area, and the wires connecting the modules adopt a serpentine routing process, utilizing geometric redundancy to release tensile stress and prevent open circuits.

2. The flexible high-voltage pulse generator based on a micro-pulse transformer network according to claim 1, characterized in that, The rigid-flexible coupling composite substrate exhibits a specific lamination process structure in the vertical direction, which includes, from top to bottom: a surface gold conductive layer, a polyimide dielectric layer, a bottom gold conductive layer, and a local reinforcement layer.

3. A flexible high-voltage pulse generator based on a micro-pulse transformer network according to claim 2, characterized in that, The top-layer immersion gold conductive layer retains a continuously laid copper foil reference ground plane in the device bearing area corresponding to the low-voltage part of the transformer primary side. The continuously laid copper foil covers the area of ​​the DC boost module, the single-stage Marx pulse modulation module, the control module, the drive module, the auxiliary power module, and the area where the traces of the above modules are located. The copper foil coverage ratio is not less than 50% of the overall device bearing area. The thickness of the reinforcement layer is 0.2mm-0.5mm, and its edges are chamfered to prevent puncturing the flexible cover film.

4. A flexible high-voltage pulse generator based on a micro-pulse transformer network according to claim 2, characterized in that, The rigid-flexible coupling composite substrate is divided into a rigid device bearing area with a four-layer structure including a reinforcing layer and a flexible deformation area with only the first three layers and no reinforcing layer through the laminated structure.

5. A flexible high-voltage pulse generator based on a micro-pulse transformer network according to claim 2, characterized in that, The lamination process is achieved through the following material selection and process steps: Step S1: Material selection for the flexible dielectric layer: The polyimide dielectric layer and the conductive layer substrate above and below it are made of high temperature resistant and corona resistant PI copper clad laminate as raw material. The PI is adhesive-free polyimide, which eliminates the high thermal resistance and easy aging problems caused by traditional adhesive layers by utilizing the characteristics of adhesive-free substrate. Step S2, Treatment of the conductive layer: The copper foil on the surface and bottom of the raw material is etched to form a circuit pattern; a chemical immersion gold surface treatment process is applied to the conductive pads on the device carrier area to form a surface and bottom immersion gold conductive layer; the bottom immersion gold conductive layer retains a large area of ​​complete copper foil in the rigid device carrier area as a common ground plane and auxiliary heat dissipation layer for the circuit; the conductive pads on the surface of the device carrier area are treated with a chemical immersion gold surface treatment process. Step S3, reinforcement layer bonding: The local reinforcement layer is made of FR4 fiberglass board or steel sheet and is attached to the back of the device bearing area by hot pressing or bonding process; the reinforcement layer covers the projection area of ​​DC boost, Marx modulation and transformer network, and serves as a mechanical support platform and heat sink for the components; the power devices on the front are thermally connected to the bottom copper foil.

6. A flexible high-voltage pulse generator based on a micro-pulse transformer network according to claim 1, characterized in that, The parameters of the DC boost module and the single-stage Marx pulse modulation module are matched as follows: the DC boost module is configured to boost the input voltage to the DC bus voltage; the module integrates a current detection loop, is configured with a feedback resistor voltage divider network for adjusting the output voltage, and suppresses the start-up impact through soft start and overcurrent limiting functions.

7. A flexible high-voltage pulse generator based on a micro-pulse transformer network according to claim 1, characterized in that, The energy storage capacitor in the single-stage Marx pulse modulation module is a surface-mount high-voltage multilayer ceramic capacitor, and the switching device is a MOSFET including a fast-charging diode. Its working logic is as follows: when the switch is turned on, the DC boost module charges the energy storage capacitor through the fast-charging diode; when the drive signal is switched, the switch quickly connects the energy storage capacitor in series to the primary side of the transformer, so that the primary side obtains a pulse voltage with instantaneous amplitude increase.

8. A flexible high-voltage pulse generator based on a micro-pulse transformer network according to claim 1, characterized in that, The single-stage Marx pulse modulation module utilizes the DC bus voltage and requires only a single energy storage capacitor and a single-stage switching device to complete the pulse switching, avoiding the stacking of capacitor arrays and complex isolation drive circuits in multi-stage Marx circuits.

9. A flexible high-voltage pulse generator based on a micro-pulse transformer network according to claim 1, characterized in that, The miniaturized assembly process of the IPOS pulse transformer network involves surface mount technology (SMT) soldering the miniature pulse transformers onto the rigid device carrier area. The spacing between adjacent high-voltage traces in the secondary-side series connection lines of the IPOS topology is set by calculating the dielectric breakdown field strength, and copper plating around the traces is removed to ensure that no dielectric breakdown or creepage flashover occurs between high-voltage nodes when the substrate bends, causing local electric field distortion. The minimum creepage distance between adjacent high-voltage traces is determined based on the surface flashover field strength characteristics of the PI dielectric. Based on the following formula: in, For safety reasons, This represents the peak value of the pulse voltage across the secondary side of a single transformer. The threshold value for surface flashover field strength in flexible PI dielectric materials.

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