A flexible array pressure sensor

Abstract

The application provides a flexible array pressure sensor, which comprises a plurality of sensitive elements, a flexible plate and a flexible packaging structure; the flexible plate comprises arrayed pads; the flexible packaging structure comprises a flexible packaging shell and potting glue; the plurality of sensitive elements are welded on the arrayed pads; the flexible plate is arranged in the flexible packaging shell; and the potting glue is filled in a slotted structure at a lower end of the flexible packaging shell, so as to solidify the sensitive elements, the flexible plate and the flexible packaging shell into an integral whole.

Description

Technical Field

[0001] This invention belongs to the field of pressure sensor technology, and specifically relates to a flexible array pressure sensor. Background Technology

[0002] With the development of technology, pressure sensors have been widely used in many fields. Sensors used in the aerospace field often require the measurement of distributed surface pressure. For example, drones and spacecraft experience aerodynamic pressure on their wing surfaces or control surfaces during flight. Achieving distributed measurement of surface aerodynamic pressure is crucial for assessing the structural strength and lifespan of such equipment. Traditional pressure sensors suffer from the following problems:

[0003] (1) Large size and difficult to implement distributed pressure measurement Traditional pressure sensors consist of a pressure inlet, housing, sensing element, circuit board, and connectors. The sensors are relatively large, and in actual use, it is necessary to drill a threaded hole at the pressure measurement point and then tighten the sensor pressure inlet to the measurement point. This installation method not only damages the airfoil or control surface, affecting the structural strength, but also affects the aerodynamic pressure distribution at the measurement point, making accurate measurement impossible. Furthermore, due to the large size of the product, it can only achieve single-point pressure measurement and does not meet the requirements of distributed pressure measurement.

[0004] (2) Low frequency response Traditional piezoresistive pressure sensors have complex manufacturing processes for their sensing elements. They employ an internal silicone oil-encapsulated isolation structure, transmitting external environmental pressure to the silicon piezoresistive sensing chip via a corrugated diaphragm and silicone oil. Due to the response delay of the transmission medium, the sensing chip responds slowly to the measured pressure. Therefore, traditional pressure sensors cannot achieve dynamic pressure measurements above 1kHz. The complex surface aerodynamic pressures experienced by drones, spacecraft, and other aircraft during atmospheric flight necessitate the measurement of high-frequency dynamic pressure. High-frequency dynamic pressure sensors are used to measure pressure parameters in ground-based wind tunnel tests of these aircraft.

[0005] (3) The anti-interference capability of analog signal transmission is weak. Traditional pressure sensors transmit data using analog signals such as voltage and current. During transmission, they are susceptible to electromagnetic interference, which can lead to signal distortion or decreased accuracy. This is especially true in distributed array pressure testing, where the analog signal transmission from multiple sensors requires multiple wires, which are not only heavy but also subject to signal interference. Traditional signal transmission methods cannot achieve reliable transmission of distributed pressure measurement signals. Summary of the Invention

[0006] The technical problem solved by this invention is to overcome the shortcomings of traditional sensors and provide a flexible array pressure sensor that can achieve attached assembly and distributed pressure measurement.

[0007] This invention provides a flexible array pressure sensor, comprising a plurality of sensitive elements, a flexible plate, and a flexible packaging structure; the flexible plate includes an array of pads; the flexible packaging structure includes a flexible packaging shell and a potting compound; the plurality of sensitive elements are soldered onto the array of pads; the flexible plate is arranged inside the flexible packaging shell; the potting compound fills a slotted structure at the lower end of the flexible packaging shell to cure the sensitive elements, the flexible plate, and the flexible packaging shell into a whole.

[0008] Furthermore, the sensitive element includes a sintering base, a piezoresistive chip, bonding gold wires, a top cover, protective adhesive, and gold needles; the sintering base and the gold needles are fixed by a glass sintering process; the piezoresistive chip is fixed in the chip mounting slot of the sintering base, receives external pressure, and outputs a differential voltage signal; the gold needles are connected to the electrodes on the piezoresistive chip through the bonding gold wires to transmit the differential voltage signal to the outside; the top cover has a circular ring structure and is fixed to the sintering base by welding; the protective adhesive is injected through the central hole of the top cover to ensure a sealed and waterproof property.

[0009] Furthermore, the flexible board also includes a pad reinforcement substrate, traces, and ribbon pads; the pad reinforcement substrate is arranged at the bottom of the arrayed pads and the ribbon pads to improve the regional structural strength; the traces are made of copper foil and are arranged on the flexible board to achieve mutual isolation between electrical signals; the ribbon pads are used to realize the input of external power supply and the output of measurement signals. The flexible board includes a signal layer, an insulating layer, a power supply layer, and a ground layer; the signal layer is used to transmit measurement signals; the power supply layer and the ground layer are used to supply power to the sensitive element; the insulating layer is used to isolate conductive areas and prevent short circuits.

[0010] Furthermore, a pressure measurement method using a flexible array pressure sensor includes two steps: (1) Pressure measurement signals are acquired based on a microcontroller and a multi-channel ADC chip; (2) Pressure measurement signals are processed based on embedded software.

[0011] Furthermore, step (2) includes the following steps: 1) Determine if the multi-channel ADC chip is ready; 2) Determine if the data conversion is complete; 3) Determine whether the trigger flag of the data sending task is set.

[0012] Further, step 1) includes the following steps: Initialize the microcontroller system clock and pin configuration; send control commands via SPI to determine if the multi-channel ADC chip is in a ready state; if so, enable the continuous conversion mode of the multi-channel ADC chip, convert the acquired array pressure measurement signal into multiple 16-bit pressure values, initialize the moving average filter module queue, and start the timer and enable interrupts; if not, continue to determine if the multi-channel ADC chip is in a ready state.

[0013] Further, step 2) includes the following steps: A timer sets up a 1ms time slice to continuously poll the flag of the data conversion task to determine whether all the collected pressure measurement signals have been converted into 16-bit pressure values. If so, the converted 16-bit pressure values ​​are read and stored, the data is filtered using FIFO and moving average, and the filtered pressure values ​​are converted into the corresponding pressure values ​​according to the formula. If not, the data conversion continues.

[0014] Furthermore, step 3) includes the following steps: By querying the cumulative number of time slices, the test data is packaged and sent to the host computer periodically. The data sending protocol requires sending packaged data once every 20ms. It is determined whether the cumulative number of time slices has reached 20. If so, the trigger flag of the sending task is set, and the test data is packaged and sent to the host computer. If not, proceed to step 2.

[0015] The advantages of this invention compared to the prior art are as follows: a) This invention provides a flexible array pressure sensor, and innovatively designs a thin pressure sensing element suitable for flexible array pressure testing, achieving a wide temperature range and high precision; the sensor's operating temperature range can reach up to 125℃, the sensing element adopts a full-bridge structure, and the bottom shell adopts a stainless steel structure, eliminating the influence of curved surface bending on measurement accuracy, with a comprehensive measurement accuracy of no more than 0.5%FS and nonlinearity of no more than 0.1%.

[0016] b) This invention provides a flexible array pressure sensor with the advantage of being able to be attached for assembly; the sensor thickness is no more than 5mm, it can realize absolute pressure measurement, the range covers 0-1Mpa, the array density is no more than 1doc / cm2, and the number of measurement points can be freely expanded according to actual testing needs, realizing flexible attachment installation and high-precision measurement of array pressure in the measured area.

[0017] c) This invention provides a flexible array pressure sensor, and innovatively proposes a digital circuit and software design method adapted to the array pressure sensor, which can realize high-precision transmission of multiple detection signals; the array signal is acquired based on a scheme of microprocessor, multi-channel ADC chip and analog switch, and the measurement data of the array sensitive element is normalized by the processor and then uniformly packaged and sent to the host computer. Digital transmission improves the anti-interference capability, and the host computer can display the pressure distribution map of the measured point in real time. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the sintering base for the sensitive element of the flexible array pressure sensor according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the bonding of the sensitive element of the flexible array pressure sensor according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the internal packaging structure of the sensitive element of the flexible array pressure sensor according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the flexible plate structure of the flexible array pressure sensor according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the arrayed packaging structure of a flexible array pressure sensor according to an embodiment of the present invention; Figure 6 This is a flowchart of the data processing software for a flexible array pressure sensor according to an embodiment of the present invention.

[0019] Among them: 11-Sintering base; 12-Piezoresistive chip; 13-Gold bonding wire; 14-Top cover; 15-Protective adhesive; 21-Arrayed pads; 22-Pad-reinforced substrate; 23-Trace; 24-Flexible board; 25-Package pads; 31-Flexible packaging shell; 32-Potent. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0021] Example 1 This invention provides a flexible array pressure sensor, comprising a plurality of sensitive elements, a flexible plate, and a flexible packaging structure; the flexible plate includes an array of pads 21; the flexible packaging structure includes a flexible packaging shell (31) and a potting compound 32; the plurality of sensitive elements are soldered onto the array of pads 21; the flexible plate is arranged inside the flexible packaging shell 31; the potting compound 32 fills the slotted structure at the lower end of the flexible packaging shell 31, for curing the sensitive elements, the flexible plate, and the flexible packaging shell 31 into a whole.

[0022] The sensitive element includes a sintering base 11, a piezoresistive chip 12, a bonding gold wire 13, a top cover 14, a protective adhesive 15, and gold needles. The sintering base 11 and the gold needles are fixed by a glass sintering process. The piezoresistive chip 12 is fixed in the chip mounting slot of the sintering base 11, receives external pressure, and outputs a differential voltage signal. The gold needles are connected to the electrodes on the piezoresistive chip 12 through the bonding gold wire 13 to transmit the differential voltage signal to the outside. The top cover 14 is a ring structure and is fixed to the sintering base 11 by welding. The protective adhesive 15 is injected through the central hole of the top cover 14 to ensure a sealed and waterproof property.

[0023] The flexible board also includes a pad-reinforcing substrate 22, traces 23, and ribbon pads 25; the pad-reinforcing substrate 22 is arranged at the bottom of the arrayed pads 21 and the ribbon pads 25 to improve the structural strength of the area; the traces 23 are made of copper foil and are arranged on the flexible board to achieve mutual isolation between electrical signals; the ribbon pads 25 are used to realize the input of external power supply and the output of measurement signals; The flexible board includes a signal layer, an insulating layer, a power supply layer, and a ground layer; the signal layer is used to transmit measurement signals; the power supply layer and the ground layer are used to supply power to the sensitive element; the insulating layer is used to isolate conductive areas and prevent short circuits.

[0024] A pressure measurement method using a flexible array pressure sensor includes two steps: (1) Pressure measurement signals are acquired based on a microcontroller and a multi-channel ADC chip; (2) Pressure measurement signals are processed based on embedded software.

[0025] Step (2) includes the following steps: 1) Determine if the multi-channel ADC chip is ready; 2) Determine if the data conversion is complete; 3) Determine whether the trigger flag of the data sending task is set.

[0026] Step 1) includes the following steps: Initialize the microcontroller system clock and pin configuration; send control commands via SPI to determine if the multi-channel ADC chip is in a ready state; if so, enable the continuous conversion mode of the multi-channel ADC chip, convert the acquired array pressure measurement signal into multiple 16-bit pressure values, initialize the moving average filter module queue, and start the timer and enable interrupts; if not, continue to determine if the multi-channel ADC chip is in a ready state.

[0027] Step 2) includes the following steps: A timer sets up a 1ms time slice to continuously poll the flag of the data conversion task to determine whether all the collected pressure measurement signals have been converted into 16-bit pressure values. If so, the converted 16-bit pressure values ​​are read and stored, the data is filtered using FIFO and moving average, and the filtered pressure values ​​are converted into the corresponding pressure values ​​according to the formula. If not, the data conversion continues.

[0028] Step 3) includes the following steps: By querying the cumulative number of time slices, the test data is packaged and sent to the host computer periodically. The data sending protocol requires sending packaged data once every 20ms. It is determined whether the cumulative number of time slices has reached 20. If so, the trigger flag of the sending task is set, and the test data is packaged and sent to the host computer. If not, proceed to step 2.

[0029] Example 2 The flexible array pressure sensor consists of two parts: hardware and software. The hardware mainly includes the sensing element, the FPC flexible board, and the flexible packaging structure, while the software is the array sensor signal processing method.

[0030] 1. Array Sensitive Element Structure Design Technology The sensitive element includes a sintering base 11, a piezoresistive chip 12, a gold bonding wire 13, a top cover 14, and a protective adhesive 15.

[0031] The sintering base 11 has a height of 2mm and an outer diameter of no more than 8mm. The sintering base is manufactured using a glass-metal sintering process. The gold lead pins and the sintering base 11 are fixed together by the glass sintering process to achieve sealing of the measurement medium and conduction of electrical signals. There are 5 gold lead pins, which correspond to the 5 electrodes of the piezoresistive chip 12, and the electrodes are defined as IN-, IN-, OUT+, IN+, and OUT-.

[0032] The piezoresistive chip 12 is fixed in the chip mounting slot of the sintering base 11 by adhesive bonding. The silicon-based piezoresistive chip 12, which is manufactured using MEMS technology, directly bears pressure. The chip has an absolute pressure package structure. A Wheatstone bridge is etched on the chip surface. When the chip is under pressure, the resistance of the bridge arm of the Wheatstone bridge changes due to the piezoresistive effect, and the bridge outputs a differential voltage signal.

[0033] The bonding wire 13 is made of gold. The Wheatstone bridge electrode on the piezoresistive chip 12 and the gold pin of the sintering seat 11 are electrically connected through the gold wire ball bonding process. The gold pin of the sintering seat 11, the piezoresistive chip 12 and the bonding wire 13 are connected as one unit. The signal is transmitted from the piezoresistive chip to the outside world through the gold pin.

[0034] The top cover 14 is a circular structure made of stainless steel. The central hole of the top cover is used to transmit the medium pressure. The top cover 14 and the sintering seat 11 are fixed by laser welding. The weld penetration depth is required to be no less than 0.5mm. After assembly, the height of the whole machine is no more than 3.2mm. The top cover 14 ensures the reliable fixation of the piezoresistive chip 12 and the bonding gold wire 13.

[0035] The protective adhesive 15 is injected through the center hole of the top cover 14 to fix the piezoresistive chip 12, the bonding gold wire 13, and the lead pins. After curing, the protective adhesive 15 ensures the product's sealing and waterproof properties. After curing, the protective adhesive 15 ensures excellent force transmission performance and has extremely low temperature stress over a wide temperature range (-50℃ to +125℃), which will not affect the zero-point temperature stability and sensitivity temperature stability of the pressure chip, enabling high-precision measurement.

[0036] The sensing element eliminates the traditional silicone oil and corrugated diaphragm dielectric isolation structure, so pressure is no longer transmitted through the medium. The piezoresistive chip 12 can sense high-frequency pneumatic pressure, and the structure is simple and reliable.

[0037] 2. Flexible Array FPC Circuit Board Design Technology The FPC flexible board mainly consists of sensitive element pads 21, pad reinforcement substrate 22, traces 23, flexible board 24, and ribbon cable pads 25.

[0038] The sensitive element pads 21 are distributed in an M×N array. The distribution size of each solder point on the sensitive element pads 21 is perfectly matched with the distribution size of the sensitive element pins. During assembly, the positions of the lead pins of the sensitive element and the solder points on the pads correspond one-to-one, and the sensitive element is soldered to the pads 21.

[0039] The pad reinforcement substrate 22 enhances the structural strength of the area at the bottom of the sensitive element pad 21 and the cable pad 25 by filling with reinforcement material.

[0040] The trace 23 is embedded in a flexible thin plastic board and can be bent and folded at will with the flexible circuit board. The material of trace 23 is copper foil, which adopts a dynamically bendable rolled copper process. The base insulating material is evenly distributed on the outside of the copper foil to ensure mutual insulation and non-interference between different signals.

[0041] The flexible board 24 is designed as a multilayer FPC board, including a signal layer, an insulating layer, a power supply layer, and a ground layer. The signal layer transmits measurement signals, while the power supply and ground layers supply power to the sensitive components. The insulating layer is achieved by coating polyimide films on both sides of the conductive layer. The function of the insulating layer is to isolate the conductive layer, prevent short circuits and interference, and provide electrical insulation performance for the circuit board.

[0042] The ribbon cable pad 25 enables external power input and measurement signal output.

[0043] 3. Flexible packaging structure assembly technology The flexible packaging structure consists of a flexible packaging shell 31 and a potting compound 32.

[0044] The flexible encapsulation shell 31 is fabricated using a 3D printing process with molding materials. M×N array openings are distributed on the upper end of the shell 31. After the pressure-sensitive element and the flexible plate are welded together, they are embedded into the holes of the flexible encapsulation shell 31. The top cover of the sensitive element is flush with the upper surface of the flexible encapsulation shell 31. The lower end of the flexible shell has a groove structure. The groove is filled with potting compound 32. The silicone flows naturally in the filling groove. After curing, the flexible encapsulation shell 31 and the pressure-sensitive element are integrated into one package. The silicone is elastic and can be bent according to the overall structure.

[0045] 4. Overall assembly process technology (1) First, the sensitive element is pressure tested using a calibration fixture.

[0046] (2) The calibrated sensitive elements are soldered to the corresponding pads on the flexible board, and the sensitive elements distributed in the M×N array are powered uniformly on the flexible board.

[0047] (3) The flexible board is embedded into the flexible packaging structure, and the sensitive elements distributed in the M×N array are correspondingly assembled into the M×N array openings at the top of the flexible packaging structure.

[0048] (4) Fill the back of the flexible packaging structure with potting silicone. The potting adhesive flows naturally and is cured to ensure that the sensitive components, flexible board and flexible packaging structure are cured into one.

[0049] 5. Software Design Methods for Arrayed Signals The scheme based on microprocessor, multi-channel ADC chip and analog switch realizes the acquisition of array signal. The measurement data of array sensitive element is normalized by processor and then uniformly packaged and transmitted to host computer.

[0050] The software flow is as follows: First, the microprocessor system clock and function pins are configured. Then, control commands are sent via serial port to determine whether the arrayed ADC is in a ready state. Once ready, a command is sent to enable continuous conversion mode for the ADC. The microprocessor reads and stores the pressure value after conversion. An internal circular queue is established to perform FIFO and moving average filtering on the data. A 1ms time-base interrupt is established internally. By accumulating 20 data transmissions and continuously polling the flag bits of multiple tasks within a 1ms time slice, time-division multiplexing of the CPU can be achieved, effectively improving efficiency.

[0051] Example 3 A sensitive element was designed for the flexible array pressure sensor, eliminating the need for traditional corrugated diaphragms and silicone oil filling structures. It primarily consists of a sensitive chip, a sintered base 11, and a housing. The overall outer diameter is 8mm and the height is 3.2mm. The array sensitive element has five electrical nodes, arranged clockwise as IN-, IN-, OUT+, IN+, OUT-. The sintered base 11 is manufactured using a glass-metal sintering process. The metal pins of the sintered base are gold-plated to 1.3-5.7µm to ensure good solderability; the other end of the pins is burr-free for easy insertion, ensuring concentricity between the pins and the holes; the withstand voltage between the glass insulator and the base is greater than 20MPa, and the insulation resistance is greater than 500MΩ / 500V; the operating temperature range is -55℃ to 150℃. The housing is made of 316L stainless steel and is connected to the sintered base via laser welding.

[0052] After the sintering base 11 and the outer shell are laser welded together, the sensitive chip electrode and the bonding gold wire 13 are still exposed to the environment. The solution involves using a dispensing machine to fill the sensitive chip with sealant. Dielectric fluorosilicone MISG09A / B is a sealant specifically developed for pressure sensors, possessing advantages such as waterproofing, corrosion resistance, and low stress. Current test results show that MISG09A / B adhesive has excellent temperature stability, ensuring a thermal hysteresis of <0.25% (-55℃~125℃) in a single dispensing process, with a pass rate greater than 80%.

[0053] The sensitive element is soldered to the corresponding pad on the flexible board, and the power supply and array pressure measurement signal are read through the flexible board.

[0054] The arrayed packaging structure isolates the flexible board from the external environment. The flexible board for welding sensitive components is embedded in the arrayed packaging structure, and Dq552J-127 glue is applied to the back to solidify the flexible board and the packaging structure into one unit.

[0055] Hardware acquisition of array pressure measurement signals is implemented using the STM32F030F4P6 microcontroller and the AD7606 multi-channel ADC chip. For miniaturization and low cost considerations, the main control circuit uses the STM32F030 series microcontroller. The STM32F030F4P6, the smallest in the STM32F030 series, has only 20 pins, a chip size of 6.4mm × 4.4mm, 16KB of flash memory and 4KB of RAM, and integrates I2C, SPI, and UART serial communication modules to meet the design requirements. The AD7606 is a 16-bit synchronous sampling analog-to-digital data acquisition system (DAS) with 8 acquisition channels. On-chip integration includes analog input clamping protection, a second-order anti-aliasing filter, a track-and-hold amplifier, a 16-bit charge-redistribution successive approximation ADC core, digital filters, a 2.5V reference voltage source and buffer, and high-speed serial and parallel interfaces.

[0056] Embedded software based on a microcontroller is used to implement multi-channel data acquisition, digital filtering, normalization processing, and packet transmission. The software flow is as follows: First, the STM32F030F4P6 system clock and pin configuration are initialized. Then, a control command is sent via SPI to determine whether the AD7606 is in a ready state. Once ready, a command is sent to enable the AD7606 to start continuous conversion mode. The STM32F030F4P6 reads and stores the converted 16-bit pressure value. An internal circular queue is established for FIFO and moving average filtering of the data. In the main program loop, the measured value is read and converted into the corresponding pressure and temperature values ​​according to the formula. The trigger flag of each task is polled periodically. When the corresponding task flag is set, the corresponding task is started immediately, such as data fault diagnosis, filtering, data framing, and transmission, while the trigger flag is reset. The software design employs a basic timer to establish a 1ms time base signal and enables update event interrupts. Every 1ms, the time base interrupt decrements the trigger time setting of each task by 1 and polls the flag bits of each task. When the trigger time setting of each task reaches 0, the task flag bit is immediately set. Upon detecting the flag bit, the main loop immediately executes the corresponding task and simultaneously resets the task flag bit. For example, according to a generalized product technical protocol, the sensor needs to send a frame of measurement data every 20ms. Therefore, the trigger time setting of the data transmission task, Uart_Send_Tim, can be set to 20. Every 1ms, the Uart_Send_Tim setting is decremented by 1. When it reaches 0, the data transmission task is triggered, and the setting is reset to 20. Establishing a 1ms time base interrupt and transmitting data 20 times cumulatively, instead of directly setting the timer interrupt time to 20ms, is to expand the microcontroller's functionality. Establishing a 1ms time slice and continuously polling the flag bits of multiple tasks enables time-sharing multiplexing of the CPU, effectively improving efficiency, which is currently the mainstream microcontroller main program architecture.

[0057] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flexible array pressure sensor, characterized in that, The device includes several sensitive elements, a flexible board, and a flexible packaging structure. The flexible board includes an array of pads (21). The flexible packaging structure includes a flexible packaging shell (31) and a potting compound (32). The several sensitive elements are soldered onto the array of pads (21). The flexible board is arranged inside the flexible packaging shell (31). The potting compound (32) is filled in the slotted structure at the lower end of the flexible packaging shell (31) to solidify the sensitive elements, the flexible board, and the flexible packaging shell (31) into a whole.

2. The flexible array pressure sensor according to claim 1, characterized in that, The sensitive element includes a sintering base (11), a piezoresistive chip (12), a bonding gold wire (13), a top cover (14), a protective adhesive (15), and gold needles; the sintering base (11) and the gold needles are fixed by a glass sintering process; the piezoresistive chip (12) is fixed in the chip mounting slot of the sintering base (11), receives external pressure, and outputs a differential voltage signal; the gold needles are connected to the electrodes on the piezoresistive chip (12) through the bonding gold wire (13) to transmit the differential voltage signal to the outside; the top cover (14) is a ring structure and is fixed to the sintering base (11) by welding; the protective adhesive (15) is injected through the central hole of the top cover (14) to ensure a sealed and waterproof property.

3. The flexible array pressure sensor according to claim 1, characterized in that, The flexible board also includes a pad reinforcement substrate (22), traces (23), and ribbon pads (25); the pad reinforcement substrate (22) is arranged at the bottom of the arrayed pads (21) and the ribbon pads (25) to improve the structural strength of the area; the traces (23) are made of copper foil and are arranged on the flexible board to achieve mutual isolation between electrical signals; the ribbon pads (25) are used to realize the input of external power supply and the output of measurement signals; The flexible board includes a signal layer, an insulating layer, a power supply layer, and a ground layer; the signal layer is used to transmit measurement signals; the power supply layer and the ground layer are used to supply power to the sensing element; The insulating layer is used to isolate conductive areas and prevent short circuits.

4. A pressure measurement method using a flexible array pressure sensor according to any one of claims 1 to 3, characterized in that, It includes two steps: (1) Pressure measurement signals are acquired based on a microcontroller and a multi-channel ADC chip; (2) Pressure measurement signals are processed based on embedded software.

5. The pressure measurement method of the flexible array pressure sensor according to claim 4, characterized in that, Step (2) includes the following steps: 1) Determine if the multi-channel ADC chip is ready; 2) Determine if the data conversion is complete; 3) Determine whether the trigger flag of the data sending task is set.

6. The pressure measurement method of the flexible array pressure sensor according to claim 5, characterized in that, Step 1) includes the following steps: Initialize the microcontroller system clock and pin configuration; send control commands via SPI to determine if the multi-channel ADC chip is in a ready state; if so, enable the continuous conversion mode of the multi-channel ADC chip, convert the acquired array pressure measurement signal into multiple 16-bit pressure values, initialize the moving average filter module queue, and start the timer and enable interrupts; if not, continue to determine if the multi-channel ADC chip is in a ready state.

7. The pressure measurement method of the flexible array pressure sensor according to claim 5, characterized in that, Step 2) includes the following steps: A timer sets up a 1ms time slice to continuously poll the flag of the data conversion task to determine whether all the collected pressure measurement signals have been converted into 16-bit pressure values. If so, the converted 16-bit pressure values ​​are read and stored, the data is filtered using FIFO and moving average, and the filtered pressure values ​​are converted into the corresponding pressure values ​​according to the formula. If not, the data conversion continues.

8. The pressure measurement method of the flexible array pressure sensor according to claim 5, characterized in that, Step 3) includes the following steps: By querying the cumulative number of time slices, the test data is packaged and sent to the host computer periodically. The data sending protocol requires sending packaged data once every 20ms. It is determined whether the cumulative number of time slices has reached 20. If so, the trigger flag of the sending task is set, and the test data is packaged and sent to the host computer. If not, proceed to step 2.

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