Human body infrared sensing module

Abstract

The utility model discloses a human body infrared sensing module, which comprises a metal shell, a metal base, a power supply pin, a signal pin, an infrared optical filter, an optical transmission clamping plate, a light diffusion sheet, a ceramic substrate, an infrared sensing body capacitor, a sensing body support capacitor, a circuit board and a digital signal processing chip. The capacitive PIR pyroelectric sensor is characterized in that a U-shaped infrared sensitive material is printed on the ceramic substrate, the material is sintered on the ceramic substrate to form an infrared inductor, the infrared inductor and an inductor support capacitor form a capacitive PIR pyroelectric sensor, a digital signal processing chip is integrated on a circuit board and packaged in a metal shell and a metal base, and the digital signal processing chip is connected with the metal shell and the metal base. By optimizing the structural design and integrating an intelligent algorithm, the sensitivity, stability and anti-interference capability of the module are remarkably improved, and the module is suitable for the fields of smart home, security monitoring, automation equipment and the like.

Description

Technical Field

[0001] This utility model relates to a human infrared sensing module, specifically a capacitive PIR (pyroelectric) sensor module with high sensitivity, high stability, and intelligent functions, suitable for smart homes, security monitoring, automation equipment, and other fields. Background Technology

[0002] Existing human infrared sensing modules mainly rely on traditional pyroelectric materials and structural designs, which have the following problems:

[0003] Low sensitivity: Traditional pyroelectric materials result in insufficient sensing sensitivity.

[0004] Large temperature drift: The sensing performance is unstable under different ambient temperatures.

[0005] Poor anti-interference ability: It is easily affected by background noise and has a high false alarm rate.

[0006] Complex manufacturing process: The production process requires multiple steps, and it is difficult to ensure consistency.

[0007] To address the aforementioned issues, this invention proposes a novel human infrared sensing module. By introducing new materials and optimizing the structural design, the infrared sensor and digital chip are integrated and packaged within a sensor shield to process the sensing signal, significantly improving the module's performance and reliability. Utility Model Content

[0008] To solve the above-mentioned technical problems, this application provides the following technical solution:

[0009] 1. Technical issues:

[0010] This invention aims to solve the problems of low sensitivity, large temperature drift, poor anti-interference ability and complex manufacturing process of existing human infrared sensing modules, and to provide a high-performance, high-stability and intelligent human infrared sensing module.

[0011] 2. Technical Solution:

[0012] This utility model provides a human infrared sensing module, including a metal shell, a metal base, power pins, signal pins, an infrared filter, an optical passband, a diffuser, a ceramic substrate, an infrared sensor capacitor, a sensor support capacitor, a circuit board, and a digital signal processing chip. Its features are:

[0013] U-shaped infrared-sensitive material:

[0014] A novel composite ferroelectric ceramic material is used, which has a higher pyroelectric coefficient and lower temperature drift characteristics.

[0015] The material has a width of 0.5mm to 2mm and a thickness of 0.05-0.15mm. Its surface is treated with a special microstructure to enhance infrared absorption efficiency.

[0016] Asymmetric plate infrared sensor capacitance:

[0017] The asymmetric plate infrared sensor capacitors (5-1U and 5-2U) employ a unique double-layer structure design, with the inner layer being a high dielectric constant material and the outer layer being a low dielectric constant material, to optimize capacitor performance and response speed.

[0018] Adaptive temperature compensation circuit:

[0019] The infrared sensor capacitor and the sensor support capacitor together form a capacitive PIR pyroelectric sensor, and integrate an adaptive temperature compensation circuit, which can maintain stable sensing performance under different ambient temperatures.

[0020] Intelligent Algorithms:

[0021] The digital signal processing chip incorporates intelligent algorithms, high-precision AD signal processing, differential signal input, and strong anti-interference capabilities. It can analyze and filter background noise in real time, improving the accuracy and sensitivity of human body detection.

[0022] Digital signal processing chip functions:

[0023] The chip has a voltage range of 1.2-5V, power consumption of 10uA, and an operating temperature range of -25-85°C. Pin definitions: 1: OEN photoresistor enable pin (20%-80%VDD); 2: SENS sensitivity pin (0-1 / 2VDD); 3: ONTIME trigger delay time adjustment pin, 16 delay time options; 4: REL sensor output pin, outputs TTL high / low levels; 5: VSS power ground; 6: VDD sensor power supply pin. This human infrared sensor module is available in 3-pin, 4-pin, and 6-pin packages depending on the application. All signal processing is completed within the shielded package, providing stronger resistance to radio frequency interference.

[0024] Infrared filter:

[0025] A coated monocrystalline silicon wafer is used, combined with multilayer interference filtering technology, to significantly improve infrared transmittance and selectivity.

[0026] Astigmatism filter design:

[0027] The surface of the diffuser has semi-circular grooves, and the upper and lower pieces are deflected 90° and combined together. The interior forms an interlaced corrugated reflective surface in the horizontal and vertical directions with a spacing of 0.1mm to 0.5mm. It also adopts a gradient refractive index design, which helps to further improve the reception efficiency and uniform distribution of infrared signals.

[0028] Improved manufacturing methods:

[0029] Introducing high dielectric ferroelectric ceramic elements into the sintering process enhances the performance and stability of the pyroelectric material.

[0030] Corrosion prevention and protection measures:

[0031] The metal casing is welded and sealed in a closed environment, and the sensor is simultaneously filled with a protective inert gas (such as argon or nitrogen). An anti-corrosion coating is applied to the surface of the casing to improve durability and protection.

[0032] Specific features also include:

[0033] A human infrared sensing module includes a metal casing, a metal base, power pins, signal pins, an infrared filter, an optical passband, a diffuser, a ceramic substrate, an infrared sensor capacitor, a sensor support capacitor, a circuit board, and a digital signal processing chip, characterized in that:

[0034] The capacitor in the sensor support is provided with a rectangular ceramic substrate;

[0035] The ceramic substrate is printed with a U-shaped infrared-sensitive material, which is sintered on the ceramic substrate to form an infrared sensor.

[0036] The U-shaped infrared sensitive material has a width of 0.5mm to 2mm and a thickness of 0.05-0.15mm;

[0037] The sensor support is capacitively connected to the U-shaped infrared capacitor electrode plate, located at both ends of the ceramic substrate.

[0038] The infrared sensor and the support capacitor together form an asymmetric plate infrared sensor capacitor with capacities of 5-1U and 5-2U.

[0039] The aforementioned diffuser will refract or reflect the infrared signal passed through the infrared filter onto the capacitor plate of the inductive element;

[0040] The infrared sensor capacitor and the sensor support capacitor together form a capacitive PIR pyroelectric sensor.

[0041] The digital signal processing chip has its input terminal connected to the capacitor of the sensor support, and the sensing control signal is output from the signal pin of the metal base.

[0042] The digital signal processing chip has a built-in intelligent algorithm that can analyze and filter background noise in real time, improving the accuracy and sensitivity of human body detection.

[0043] Preferably, wherein:

[0044] The infrared filter and diffuser are located on the upper and lower sides of the optical pass card, embedded in the top window of the metal shell, fixed with black resin glue, and encapsulated inside the metal shell of the sensor.

[0045] The infrared filter is made of coated monocrystalline silicon wafer to improve infrared transmittance.

[0046] Preferably, wherein:

[0047] The surface of the diffuser has a semi-circular groove, and the upper and lower pieces are deflected by 90° and combined together, forming an interlaced corrugated reflective surface in the horizontal and vertical directions inside.

[0048] The spacing of the corrugated reflective surfaces is 0.1 mm to 0.5 mm, which helps to improve the reception efficiency of infrared signals.

[0049] Preferably, wherein:

[0050] The infrared sensor capacitor has a U-shaped symmetrical structure with forks distributed in the center of the ceramic substrate, and the two ends are connected to the sensor support capacitor through the bottom electrode.

[0051] The interdigitation distance of the U-shaped symmetrical structure is 0.2 mm to 0.8 mm to optimize capacitor performance.

[0052] Preferably, wherein:

[0053] The U-shaped symmetrical capacitor body plates are printed with a protective film and sintered on a ceramic substrate.

[0054] The U-shaped symmetrical capacitor has a rectangular groove in the middle plate and a semi-circular groove in the middle of the two side plates; a precision microstructure is formed by laser etching technology to enhance mechanical strength and stability.

[0055] After the U-shaped symmetrical capacitor plate is polarized, it is welded to the inductor support capacitor through metal electrodes at both ends.

[0056] The protective film is made of specific materials (such as silicon nitride or zirconium oxide) to improve durability and stability.

[0057] Preferably, wherein:

[0058] The sensor support capacitor is rectangular with a concave center, and the electrodes at both ends are respectively connected to the infrared sensor capacitor plate and the auxiliary fixing end, and are welded to the ceramic substrate.

[0059] The capacitor connection electrodes of the inductor support are made of highly conductive materials (such as copper or silver) to improve the reliability of the electrical connection.

[0060] Preferably, wherein:

[0061] The digital signal processing chip is an 8-pin surface mount package located directly beneath the ceramic electrode plate that forms the infrared sensor.

[0062] The signal pins can be configured via external circuitry to set the signal triggering mode, sensing sensitivity, and delay time of the sensing module.

[0063] The pins are gold-plated to improve corrosion resistance and conductivity.

[0064] The power pin, signal pin, 6-pin or 4-pin are connected to external circuits via a metal base.

[0065] Preferably, wherein:

[0066] The method and steps for manufacturing the pyroelectric inductor of the sensor include:

[0067] Step 1: Grind the pyroelectric inductor ceramic powder, filter it with a 500-mesh steel screen, and prepare the inductor slurry;

[0068] Step 2: Print a conductive paste with a thickness of 0.5-12μm on a ceramic plate to fabricate the inductive body electrode;

[0069] Step 3: Print the pyroelectric inductor underlayer protective film on the ceramic and dry and cure at 160°C;

[0070] Step 4: Print a pyroelectric inductor ceramic paste with a thickness of 0.05-0.15mm on the bottom protective film to form a U-shaped capacitor plate;

[0071] Step 5: Sinter the ceramic substrate of the pyroelectric inductor at a temperature of 1000°C-1200°C for 6 hours.

[0072] Step 6: Sputter metal onto the surface of the U-shaped capacitor plate to form a silver electrode;

[0073] Step 7: Polarize the ceramic pyroelectric inductor at a polarization temperature of 135℃, a voltage of 1.5~6KV / mm, and a time of 5-10min.

[0074] Step 8: Fabricate the terminal electrodes of the inductor and weld the capacitor to the inductor support.

[0075] Step 9: Laser-cut ceramic plate, clean the surface of the sensor, and form a pyroelectric ceramic sensing unit chip;

[0076] Step 10: Solder the pyroelectric ceramic sensing element chip onto the circuit board, located at the very center of the circuit board.

[0077] Preferably, wherein:

[0078] The metal outer shell has a positioning end on the brim, which is located at the exact center of the metal base device's identification end;

[0079] The metal casing is welded and sealed in a closed environment, and the sensor is simultaneously filled with a protective inert gas (such as argon or nitrogen).

[0080] The metal casing is made of corrosion-resistant material to improve durability.

[0081] Preferably, wherein:

[0082] The circuit board is made of glass fiber or ceramic material with a thickness of 0.1-1.6mm, and connects power pins and signal pins;

[0083] The circuit board is equipped with resistors and capacitors, and the digital signal processing chip is located at the center of the circuit board.

[0084] The circuit board employs a single-layer or multi-layer design to enhance electromagnetic compatibility and heat dissipation. Beneficial effects

[0085] This invention achieves the following beneficial effects by introducing new materials, optimizing structural design, and integrating intelligent algorithms:

[0086] 1. High sensitivity: Novel ferroelectric ceramic composite materials and special microstructure treatment significantly improve infrared absorption efficiency.

[0087] Second: High stability: The adaptive temperature compensation circuit ensures stable performance under different ambient temperatures.

[0088] Third: Strong anti-interference capability: The digital chip and signal processing are shielded in the housing, which has a stronger anti-radio frequency interference capability.

[0089] 4. Simplified manufacturing process: Improved manufacturing methods have increased production efficiency and product consistency.

[0090] 5. Wide voltage range and low power consumption: power supply voltage 1.2-5V, current 10uA. Attached Figure Description

[0091] Figure 1 This is one of the overall structural schematic diagrams of the human infrared sensing module of this utility model.

[0092] Figure 2 This is the second schematic diagram of the overall structure of the human infrared sensing module of this utility model.

[0093] Figure 3 This is a schematic diagram of the power supply and signal control pins of this utility model.

[0094] Figure 4 This is a schematic diagram of the position and structure of the metal shell filter of this utility model.

[0095] Figure 5 This is a schematic diagram of the astigmatism plate of the human infrared sensing module of this utility model.

[0096] Figure 6 This is a structural schematic diagram of the integrated location of the human infrared sensing module component of this utility model.

[0097] Figure 7 This is a schematic diagram of the structure of the U-shaped infrared sensitive material of this utility model.

[0098] Figure 8 This is a schematic diagram of the internal structure of the human infrared sensing module of this utility model.

[0099] Figure 9 This utility model discloses the 6-pin package structure, equivalent circuit, and usage circuit diagram of the human infrared sensing module.

[0100] Figure 10 This utility model discloses the 4-pin package structure, equivalent circuit, and usage circuit diagram of the human infrared sensing module.

[0101] Figure 11 This utility model discloses the 3-pin package structure, equivalent circuit, and usage circuit diagram of the human infrared sensing module.

[0102] Figure 12 This is a timing diagram showing the trigger mode and output level of the human infrared sensing module of this utility model. Detailed Implementation

[0103] See Figures 1-12 This is a specific embodiment of a human infrared sensing module described in this application.

[0104] In this embodiment, the human infrared sensing module includes a metal shell 3, a metal shell brim positioning end 3-1, a metal shell top window 3-2; a metal base 2, a metal base identification end 2-1; power pins 1-5 and 1-6, circuit board pads 1-1-1 and 1-3-1; signal output pin REL 1-4, signal input pin ONE 1-1, signal input pin SENS 1-2, signal input pin ONTIME 1-3, circuit board pad 1-2-1; an infrared filter 10, an optical pass card 9, a diffuser 8, a ceramic substrate 6, U-shaped infrared sensor capacitors 7-1 and 7-2, sensor support capacitors 5-1 and 5-2, a circuit board 4, resistive and capacitive components 11, and a digital signal processing chip 12.

[0105] 1. Structural Composition

[0106] The human infrared sensing module of this utility model mainly includes the following parts:

[0107] Metal casing and base: Provide mechanical support and protection, while also offering excellent electromagnetic shielding performance.

[0108] Power supply pins and signal pins: Connect to external circuits to provide power and transmit signals.

[0109] Infrared filters and diffusers: These are used to filter and disperse infrared signals, respectively, to improve sensing accuracy.

[0110] Ceramic substrate and infrared sensor capacitor: The core sensing element adopts a new ferroelectric ceramic composite material and a double-layer structure design.

[0111] Sensor support capacitor: Connects the sensor capacitor to optimize capacitor performance.

[0112] Circuit boards and digital signal processing chips: Enable signal processing and intelligent control.

[0113] 2 Manufacturing method

[0114] The manufacturing method of this utility model includes the following steps:

[0115] Grind the pyroelectric inductor ceramic powder, filter it with a 500-mesh steel screen, and prepare the inductor slurry;

[0116] Conductive paste with a thickness of 0.5-12μm is printed on a ceramic plate to fabricate the inductive body electrode;

[0117] A pyroelectric inductor underlayer protective film is printed on ceramic and dried and cured at 160°C.

[0118] A pyroelectric inductor ceramic paste with a thickness of 0.05-0.15mm is printed on the bottom protective film to form a U-shaped capacitor plate;

[0119] Ceramic substrate for sintering pyroelectric inductors, temperature: 1000°C-1200°C, time: 6 hours;

[0120] Metal is sputtered onto the surface of the U-shaped capacitor plates to form silver electrodes;

[0121] The ceramic pyroelectric inductor is polarized at a temperature of 135℃, a voltage of 1.5~6KV / mm, and a time of 5-10min.

[0122] Fabricate the terminal electrodes of the inductor and weld the capacitor to the inductor support.

[0123] Laser cutting of ceramic plates, cleaning of the sensor surface, and formation of pyroelectric ceramic sensing unit chips;

[0124] The pyroelectric ceramic sensing element chip is soldered onto the circuit board, located at the very center of the circuit board.

[0125] Introducing rare earth elements into the sintering process enhances the performance and stability of pyroelectric materials.

[0126] 3. Working Principle

[0127] The working principle of this utility model is as follows:

[0128] Infrared signal acquisition: Infrared filters and diffusers work together to guide external infrared signals to the capacitor plates of the sensor.

[0129] Capacitance change detection: A capacitive PIR pyroelectric sensor, composed of an infrared sensor capacitor and a sensor support capacitor, detects capacitance changes and generates an electrical signal.

[0130] Signal processing: The digital signal processing chip receives electrical signals, analyzes and processes them through built-in intelligent algorithms, and finally outputs control signals.

[0131] Temperature compensation: The temperature compensation circuit ensures stable sensing performance under different ambient temperatures.

[0132] like Figures 1-11 As shown, the capacitive human infrared sensor module in this embodiment includes a metal casing 3, a metal casing brim positioning end 3-1, a metal casing top window 3-2; a metal base 2, a metal base identification end 2-1; power pins 1-5 and 1-6, circuit board pads 1-1-1 and 1-3-1; signal output pin REL 1-4, signal input pin ONE 1-1, signal input pin SENS 1-2, signal input pin ONTIME 1-3, circuit board pad 1-2-1; an infrared filter 10, an optical pass-through card 9, a diffuser 8, a ceramic substrate 6, U-shaped infrared sensor capacitors 7-1 and 7-2, sensor support capacitors 5-1 and 5-2, a circuit board 4, resistive and capacitive components 11, and a digital signal processing chip 12. The specific positions and connections of each component are as follows:

[0133] Metal casing 3: Used to protect internal components and provide electromagnetic shielding.

[0134] Metal base 2: Fixes the sensor and provides mechanical support.

[0135] Power supply pin and signal pin 1: used for input power and output signal, respectively.

[0136] Infrared filter 10: Installed at the top window of the metal casing, used to filter non-infrared light.

[0137] Diffuser 8: Located below the infrared filter, used to refract or reflect infrared signals.

[0138] Ceramic substrate 6: Supports U-shaped infrared sensitive material to form an infrared sensor capacitor.

[0139] Sensor support capacitors 5-1 and 5-2: support the infrared sensor capacitor and are electrically connected to it.

[0140] Circuit board 4: Digital signal processing chip 12, including resistors and capacitors 11 and other necessary electronic components.

[0141] U-shaped infrared-sensitive material:

[0142] like Figure 7 As shown, a U-shaped infrared sensitive material is sintered on a ceramic substrate 6 to form an infrared sensor capacitor. The material width is 0.5mm to 2mm and the thickness is 0.05-0.15mm, optimized for best performance. The U-shaped structure helps increase the surface area of ​​the material, thereby enhancing infrared absorption. The sensor support capacitor connects to the U-shaped infrared capacitor plates at both ends of the ceramic substrate. The two support capacitors have the same capacitance. The symmetrical U-shaped infrared ceramic body and the support capacitor 5 form a new set of sensing capacitors 5-1U and 5-2U, making the reverse-connected capacitor plates asymmetrical to enhance the sensitivity of the sensing signal. The external infrared signal diffuser 8 refracts or reflects the infrared signal passing through the infrared filter onto the sensor capacitor plates. The power supply for the human infrared sensing module is input through power pin 1-1, and the infrared sensing signal is output by the digital signal processing chip 12 through the REL signal pin.

[0143] Capacitive human infrared sensor module structural design:

[0144] 1. Metal casing 3 and base 2: The metal casing is made of corrosion-resistant material. An infrared filter and a diffuser are embedded in the top window and fixed and encapsulated in the sensor with black resin glue.

[0145] 2. Infrared filter 10: A coated monocrystalline silicon wafer is used to improve infrared transmittance.

[0146] 3. Astigmatism plate 8: The surface has a semi-circular groove, and the upper and lower plates are rotated 90° and combined together. The interior forms an interlaced wavy reflective surface in the horizontal and vertical directions, with a spacing of 0.1mm to 0.5mm.

[0147] 4. Ceramic substrate 6 and sensor capacitors 5-1U and 5-2U: U-shaped infrared sensitive material is printed on the ceramic substrate, and after sintering, it forms an infrared sensor with a finger-to-finger spacing of 0.2mm to 0.8mm.

[0148] 5. Sensor support capacitors 5-1 and 5-2: rectangular design with a recessed middle, and the electrodes at both ends are respectively connected to the infrared sensor capacitor plate and the auxiliary fixing end, and are welded to the ceramic substrate 6.

[0149] 6. Circuit board and digital signal processing chip 12: Circuit board 4 is made of glass fiber or ceramic material with a thickness of 0.1-1.6mm and connects power supply pins and signal pins; chip 12 is located in the center of the circuit board and adopts a low noise design.

[0150] Infrared ceramic capacitor manufacturing method:

[0151] 1. Grind the pyroelectric inductor ceramic powder: filter with a 500-mesh steel mesh and prepare the inductor slurry.

[0152] 2. Fabrication of the internal electrode of the sensor: Print a conductive paste with a thickness of 0.5-12μm on a ceramic plate.

[0153] 3. Printing the underlying protective film: Printing the pyroelectric inductor underlying protective film on the ceramic and drying and curing it at 160°C.

[0154] 4. Printing pyroelectric inductor ceramic paste: forming U-shaped capacitor plates with a thickness of 0.05-0.15mm.

[0155] 5. Sintering ceramic substrate: Temperature 1000°C-1200°C, time 6 hours.

[0156] 6. Metal sputtering: forming silver electrodes on the surface of the U-shaped capacitor plates.

[0157] 7. Polarization treatment: polarization temperature 135℃, voltage 1.5~6KV / mm, time 5-10min.

[0158] 8. Welding electrodes: Fabricate the terminal electrodes of the inductor and weld the capacitor of the inductor support.

[0159] 9. Laser cutting and cleaning: Cutting ceramic plates and cleaning the surface of the sensor to form a pyroelectric ceramic sensing unit chip.

[0160] 10. Welding the chip: Weld the pyroelectric ceramic sensing element chip onto the circuit board, located in the center of the circuit board.

[0161] like Figure 4 , Figure 6As shown, the infrared filter 10 and the diffuser 8 are located on the upper and lower sides of the light transmission plate 9, and are embedded in the top window of the metal shell 3. They are fixed by black resin glue and encapsulated in the metal shell of the sensor. The filter 10 is flush with the top surface of the metal shell 3. The black resin glue not only plays a fixing role, but also absorbs excess light and reduces interference.

[0162] The infrared filter 10 uses a coated monocrystalline silicon wafer. The choice of coated monocrystalline silicon wafer can significantly improve the transmittance of infrared light, thereby enhancing the sensitivity of the sensor. The fixing method ensures that the filter and diffuser will not shift or fall off during use, guaranteeing long-term stable working performance.

[0163] External infrared signals are directly or reflected onto the plates of sensing capacitors 5-1U and 5-2U through the filter 10 and the diffuser 8. The sensing signals are input to the circuit board through the support capacitors 5-1 and 5-2, and output by the digital signal processing chip 12 through the REL signal pin.

[0164] like Figure 5 As shown, the diffuser surface has semi-circular grooves, with two pieces offset by 90° and combined together, forming an alternating corrugated reflective surface in the horizontal and vertical directions inside. Changing the refraction angle of infrared light on the ceramic sensor capacitor improves the sensing sensitivity. The spacing of the corrugated reflective surfaces is 0.1mm to 0.5mm, which helps improve the reception efficiency of infrared signals.

[0165] The semi-circular groove and corrugated reflective surface design effectively disperse and reflect infrared light, increasing the sensor's ability to receive infrared light from different directions. Appropriate spacing optimizes the reflection effect, ensuring maximum signal reception. This composite structure enables the sensor to receive infrared signals from multiple angles, improving detection range and accuracy.

[0166] like Figure 8 As shown, the infrared sensor capacitor has a U-shaped symmetrical structure with its forks distributed at the center of the ceramic substrate 6, effectively receiving external incident signals. The two ends are connected in reverse to the capacitor supported by the sensor via bottom electrodes, canceling out interference signals caused by changes in ambient temperature. The fork spacing of the U-shaped symmetrical structure ranges from 0.2mm to 0.8mm. This U-shaped symmetrical structure and specific fork spacing design optimize capacitor performance, improving the sensor's response speed and sensitivity. The connection method of the bottom electrodes ensures good contact between the capacitor and the circuit, enhancing reliability. The symmetrical structure provides better mechanical support, reducing performance fluctuations caused by vibration or temperature changes.

[0167] like Figure 8 , Figure 7 As shown, a protective film is printed under the U-shaped symmetrical capacitor plates and sintered onto a ceramic substrate.

[0168] The protective film uses specific materials (such as silicon nitride or zirconium oxide) to improve durability and stability. The use of the protective film prevents the capacitor from being affected by the external environment, extending its service life. The selection of specific materials improves corrosion resistance and mechanical strength. The U-shaped symmetrical capacitor has a rectangular groove in the middle plate and semi-circular grooves in the middle of the two side plates. After polarization, each plate of the U-shaped symmetrical capacitor has a resistance of 160Ω, and the two ends are welded to the inductor support capacitor via metal electrodes. The specific plate structure design optimizes the electric field distribution and improves capacitor performance. The use of highly conductive metal electrodes ensures good electrical connection and reduces resistance.

[0169] like Figures 5-8 As shown, the sensor support capacitor is rectangular with a recessed center. Its two electrodes are connected to the infrared sensor capacitor plate and the auxiliary fixing end, respectively, and are soldered onto the ceramic substrate 6. The electrodes connecting the sensor support capacitors 5-1 and 5-2 are made of highly conductive materials (such as copper or silver) to improve the reliability of the electrical connection. The rectangular structure and recessed center design allow for adjustment of the sensor plate area and resistance as needed, resulting in higher sensitivity and reliability. The selection of highly conductive materials ensures a low-resistance connection, improving the reliability of signal transmission, and the soldering process ensures a long-term stable electrical connection.

[0170] The digital signal processing chip 12 is an 8-pin surface-mount package, located directly beneath the ceramic electrode forming the infrared sensor, extending from the bottom of a metal base. The pins are arranged in a circular pattern, with a distance of [distance missing] from the center of the metal base. The signal pins can be configured via external circuitry to set the signal trigger mode, sensitivity, and delay time of the sensing module. The pins are gold-plated to improve corrosion resistance and conductivity. The power pin, signal pin, pins 6, 4, and 3 are connected to the external circuitry via the metal base.

[0171] The digital signal processing chip features include: a chip voltage range of 1.2-5V, power consumption of 10uA, and an operating temperature range of -25-85°C. Pin functions include: 1: OEN photoresistor enable pin (20%-80%VDD); 2: SENS sensitivity pin (0-VDD); 3: ONTIME trigger delay time adjustment pin, with 16 delay time options; 4: REL sensor output pin, outputting TTL high and low levels; 5: VSS power ground; 6: VDD sensor power supply pin. A human infrared sensing module can be provided with... Figure 9 Appendix Figure 10 and attached Figure 11 Available in 3-pin, 4-pin, and 6-pin package forms.

[0172] The digital signal processing chip incorporates intelligent algorithms, high-precision AD signal processing, differential signal input, and strong anti-interference capabilities. It can analyze and filter background noise in real time, improving the accuracy and sensitivity of human body detection.

[0173] The chip employs two differential high-impedance input terminals as the sensor's sensitive element inputs. A 16-bit high-precision AD converter converts the voltage signal generated by the sensitive element into a digital signal. A two-stage bandpass filter then filters the digital signal output from the AD converter, effectively filtering low-frequency and high-frequency noise interference from various sources. All signal processing is completed within a shielded housing, providing stronger resistance to radio frequency interference. The sensitivity threshold and timing can be adjusted via external voltage divider resistors. It also features a light intensity sensor input terminal, allowing the sensor to operate when the ambient light level is below a set threshold.

[0174] Trigger mode functionality:

[0175] like Figure 12 As shown, under normal detection conditions, when the infrared signal received by the sensor exceeds the internal trigger threshold, a counting pulse is generated. After receiving two pulses within 4 seconds, the sensor's REL pin will output a high level to indicate the presence of a signal. Furthermore, if the received signal amplitude exceeds five times the trigger threshold, only one pulse is needed to trigger the REL to output a high level. If trigger signals are received consecutively, the high-level REL signal is maintained for a delay from the start of the last valid trigger until the delay time determined by the ONTIME pin.

[0176] Sensitivity adjustment function:

[0177] like Figures 9-12 As shown, the SENS pin uses an external resistor network to set different voltages to adjust the comparison thresholds for different signals. When grounded, the sensor comparison threshold is lowest, resulting in the highest sensor sensitivity and potentially the longest sensing distance. Input voltages exceeding 1 / 2 VDD will select the maximum threshold, at which point the sensor sensitivity is lowest, resulting in the shortest possible sensing distance. The sensor's sensing distance is related to the voltage on the SENS pin, the Fresnel lens, and the different sensitivity settings.

[0178] Delay time adjustment

[0179] like Figures 9-12 As shown, the delay time is the duration of the high-level output after the sensor reaches the comparison threshold. The input voltage of the ONTIME pin determines the time for the REL pin to remain high after the sensor is triggered. The delay time is recalculated each time a trigger signal is received, and the delay time is 1-3000 seconds.

[0180] The manufacturing method and steps of the capacitive human infrared sensing module sensor of this utility model include:

[0181] Step 1: Grind the pyroelectric inductor ceramic powder, filter it with a 500-mesh steel screen, and prepare the inductor slurry;

[0182] Step 2: Print a conductive paste with a thickness of 0.5-12μm on a ceramic plate to fabricate the inductive body electrode;

[0183] Step 3: Print the pyroelectric inductor underlayer protective film on the ceramic and dry and cure at 160°C;

[0184] Step 4: Print a pyroelectric inductor ceramic paste with a thickness of 0.05-0.15mm on the bottom protective film to form a U-shaped capacitor plate;

[0185] Step 5: Sinter the ceramic substrate of the pyroelectric inductor at a temperature of 1000°C-1200°C for 6 hours.

[0186] Step 6: Sputter metal onto the surface of the U-shaped capacitor plate to form a silver electrode;

[0187] Step 7: Polarize the ceramic pyroelectric inductor at a polarization temperature of 135℃, a voltage of 1.5~6KV / mm, and a time of 5-10min.

[0188] Step 8: Fabricate the terminal electrodes of the inductor and weld the capacitor to the inductor support.

[0189] Step 9: Laser-cut ceramic plate, clean the surface of the sensor, and form a pyroelectric ceramic sensing unit chip;

[0190] Step 10: Solder the pyroelectric ceramic sensing element chip onto the circuit board, located at the very center of the circuit board.

[0191] like Figures 1-8 As shown, the sensor's metal housing 3 has a positioning end 3-1 on its cap edge, located at the center of the metal base device identification end 2-1. The metal housing is welded and sealed in a closed environment, and the sensor is simultaneously filled with a protective inert gas (such as argon or nitrogen). The metal housing 3 is made of corrosion-resistant material to improve durability. The positioning end design facilitates installation and identification, ensuring the accuracy and consistency of the sensor during installation. Sealing and filling with inert gas prevent internal components from getting damp and oxidizing, extending service life. The choice of corrosion-resistant material improves the durability of the housing and adapts to various harsh environments.

[0192] like Figures 5-8As shown, the sensor circuit board 4 of the human infrared sensing module is made of glass fiber or ceramic material with a thickness of 0.1-1.6mm, connecting the power supply pins and signal pins. The digital signal processing chip 12 is located in the center of the circuit board and adopts a low-noise design to improve signal amplification. The circuit board adopts a single-layer or multi-layer design to enhance electromagnetic compatibility and heat dissipation performance. Choosing appropriate materials and thicknesses ensures the mechanical strength and electrical performance of the circuit board. Glass fiber or ceramic materials have good insulation and heat resistance. The low-noise design can improve signal amplification and reduce noise interference. The placement of chip 12 facilitates wiring and heat dissipation. The single-layer or multi-layer design can optimize electromagnetic compatibility and heat dissipation performance according to requirements, ensuring stable operation of the sensor in complex electromagnetic environments.

[0193] As can be seen from the above embodiments, the beneficial effects of this application are:

[0194] 1. High sensitivity: Novel ferroelectric ceramic composite materials and special microstructure treatment significantly improve infrared absorption efficiency.

[0195] Second: High stability: The adaptive temperature compensation circuit ensures stable performance under different ambient temperatures.

[0196] Third: Strong anti-interference capability: The digital chip and signal processing are shielded in the housing, which has a stronger anti-radio frequency interference capability.

[0197] 4. Simplified manufacturing process: Improved manufacturing methods have increased production efficiency and product consistency.

[0198] 5. Wide voltage range and low power consumption: power supply voltage 1.2-5V, current 10uA.

[0199] The foregoing description illustrates and describes several preferred embodiments of this application. However, as mentioned above, for those skilled in the art, the specific embodiments are merely exemplary descriptions of this utility model. Obviously, the specific implementation of this utility model is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of this utility model, or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of this utility model.

Claims

1. A human infrared sensing module, comprising a metal casing, a metal base, power pins, signal pins, an infrared filter, an optical passband, a diffuser, a ceramic substrate, an infrared sensor capacitor, a sensor support capacitor, a circuit board, and a digital signal processing chip, characterized in that: The capacitor in the sensor support is provided with a rectangular ceramic substrate; The ceramic substrate is printed with a U-shaped infrared-sensitive material, which is sintered on the ceramic substrate to form an infrared sensor. The U-shaped infrared sensitive material has a width of 0.5mm to 2mm and a thickness of 0.05-0.15mm; The sensor support is capacitively connected to the U-shaped infrared capacitor electrode plate, located at both ends of the ceramic substrate. The infrared sensor and the support capacitor together form an asymmetric plate infrared sensor capacitor with capacities of 5-1U and 5-2U. The aforementioned diffuser will refract or reflect the infrared signal passed through the infrared filter onto the capacitor plate of the inductive element; The infrared sensor capacitor and the sensor support capacitor together form a capacitive PIR pyroelectric sensor. The digital signal processing chip has its input terminal connected to the capacitor of the sensor support, and the sensing control signal is output from the signal pin of the metal base. The digital signal processing chip has a built-in intelligent algorithm that can analyze and filter background noise in real time, improving the accuracy and sensitivity of human body detection.

2. The human infrared sensing module according to claim 1, characterized in that: The infrared filter and diffuser are located on the upper and lower sides of the optical pass card, embedded in the top window of the metal shell, fixed with black resin glue, and encapsulated inside the metal shell of the sensor. The infrared filter is made of coated monocrystalline silicon wafer to improve infrared transmittance.

3. The human infrared sensing module according to claim 1, characterized in that: The surface of the diffuser has a semi-circular groove, and the upper and lower pieces are deflected by 90° and combined together, forming an interlaced corrugated reflective surface in the horizontal and vertical directions inside. The spacing of the corrugated reflective surfaces is 0.1 mm to 0.5 mm, which helps to improve the reception efficiency of infrared signals.

4. The human infrared sensing module according to claim 1, characterized in that: The infrared sensor capacitor has a U-shaped symmetrical structure with forks distributed in the center of the ceramic substrate, and the two ends are connected to the sensor support capacitor through the bottom electrode. The interdigitation distance of the U-shaped symmetrical structure is 0.2 mm to 0.8 mm to optimize capacitor performance.

5. The human infrared sensing module according to claim 4, characterized in that: The U-shaped symmetrical capacitor body plates are printed with a protective film and sintered on a ceramic substrate. The U-shaped symmetrical capacitor has a rectangular groove in the middle plate and a semi-circular groove in the middle of the two side plates; a precision microstructure is formed by laser etching technology to enhance mechanical strength and stability. After the U-shaped symmetrical capacitor plate is polarized, it is welded to the inductor support capacitor through metal electrodes at both ends. The protective film is made of silicon nitride or zirconium oxide to improve durability and stability.

6. The human infrared sensing module according to claim 1, characterized in that: The sensor support capacitor is rectangular with a concave center, and the electrodes at both ends are respectively connected to the infrared sensor capacitor plate and the auxiliary fixing end, and are welded to the ceramic substrate. The capacitor connection electrodes of the inductor support are made of copper or silver to improve the reliability of the electrical connection.

7. The human infrared sensing module according to claim 1, characterized in that: The digital signal processing chip is an 8-pin surface mount package located directly beneath the ceramic electrode plate that forms the infrared sensor. The signal pins can be configured via external circuitry to set the signal triggering mode, sensing sensitivity, and delay time of the sensing module. The pins are gold-plated to improve corrosion resistance and conductivity. The power pin, signal pin, 6-pin or 4-pin are connected to external circuits via a metal base.

8. The human infrared sensing module according to claim 1, characterized in that: The metal outer shell has a positioning end on the brim, which is located at the exact center of the metal base device's identification end; The metal casing is welded and sealed in a closed environment, and the sensor is simultaneously filled with a protective inert gas, which is argon or nitrogen. The metal casing is made of stainless steel or nickel-plated metal to improve durability.

9. The human infrared sensing module according to claim 1, characterized in that: The circuit board is made of glass fiber or ceramic material with a thickness of 0.1-1.6mm, and connects power pins and signal pins; The circuit board is equipped with resistors and capacitors, and the digital signal processing chip is located at the center of the circuit board. The circuit board is designed with a single or multiple layers to enhance electromagnetic compatibility and heat dissipation.

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