Human body infrared sensing module

Abstract

The invention discloses a human body infrared sensing module which comprises a metal shell, a metal base, a power pin, a signal pin, an infrared filter, a light 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] The present invention relates to a human infrared sensor module, in particular to a capacitive PIR (pyroelectric) sensor module with high sensitivity, high stability and intelligent functions, which is suitable for the fields of smart home, security monitoring, automation equipment, etc. Background Art

[0002] The existing human infrared sensing module mainly relies on traditional pyroelectric materials and structural design, and has 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: easily affected by background noise, with a high false alarm rate.

[0006] Complex manufacturing process: Multiple steps are required during the production process, and it is difficult to ensure consistency.

[0007] In order to solve the above problems, the present invention proposes a new type of human infrared sensing module, which introduces new materials, optimizes the structural design, and integrates the infrared sensor and the digital chip into a sensor shielding cover to process the sensing signal, thereby significantly improving the performance and reliability of the module. Summary of the invention

[0008] In order to solve the above technical problems, this application has the following technical solutions:

[0009] 1 Technical issues:

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

[0011] 2 Technical solutions:

[0012] The present invention provides a human infrared sensor module, comprising a metal shell, a metal base, a power pin, a signal pin, an infrared filter, a light pass card, a diffuser, a ceramic substrate, an infrared sensor capacitor, a sensor bracket capacitor, a circuit board and a digital signal processing chip. The characteristics are:

[0013] U-shaped infrared sensitive material:

[0014] Adopting new composite ferroelectric ceramic material, it has higher pyroelectric coefficient and lower temperature drift characteristics.

[0015] The material width is 0.5mm to 2mm, the thickness is 0.05-0.15mm, and the surface is specially microstructured to enhance the infrared absorption efficiency.

[0016] Asymmetric plate infrared sensor capacitor:

[0017] The asymmetric plate infrared sensing capacitor (5-1U and 5-2U) adopts a unique double-layer structure design, in which the inner layer is a high dielectric constant material and the outer layer is a low dielectric constant material to optimize the capacitance performance and response speed.

[0018] Adaptive temperature compensation circuit:

[0019] The infrared sensing body capacitor and the sensing body bracket capacitor 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 Algorithm:

[0021] The digital signal processing chip has built-in intelligent algorithms, high-precision AD signal processing, differential signal input method, strong anti-interference ability, and can analyze and filter background noise in real time to improve the accuracy and sensitivity of human body detection.

[0022] Digital signal processing chip functions:

[0023] The chip voltage range is 1.2-5V, the power consumption is 10uA, and the operating temperature is -25-85°. Pin definition: 1: OEN photoresistor enable terminal (20%-80% VDD); 2: SENS sensitivity pin (0-1 / 2VDD); 3: ONTIME trigger delay time adjustment pin, 16-speed delay time selection; 4: REL sensor output pin, output TTL high and low level; 5: VSS power ground; 6: VDD sensor power supply pin. The human infrared sensor module can be divided into 3-pin, 4-pin and 6-pin packaging forms according to the usage. The signal processing is all completed in the shielded tube shell, which has stronger anti-RF interference ability.

[0024] Infrared filter:

[0025] It uses coated single crystal silicon wafers and combines multi-layer interference filtering technology to significantly improve infrared transmittance and selectivity.

[0026] Diffuser design:

[0027] There are semicircular grooves on the surface of the diffuser. The upper and lower pieces are deflected 90° and compounded together, forming staggered corrugated reflective surfaces in the horizontal and vertical directions inside. The spacing is 0.1mm to 0.5mm, and a gradient refractive index design is adopted, which helps to further improve the reception efficiency and uniform distribution of infrared signals.

[0028] Improved manufacturing methods:

[0029] High dielectric constant ferroelectric ceramic elements are introduced into the sintering process to improve the performance and stability of pyroelectric materials.

[0030] Anti-corrosion and protective measures:

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

[0032] Specific features also include:

[0033] A human infrared sensor module, comprising a metal shell, a metal base, a power pin, a signal pin, an infrared filter, an optical card, a diffuser, a ceramic substrate, an infrared sensor capacitor, a sensor bracket capacitor, a circuit board and a digital signal processing chip, characterized in that:

[0034] The inductor support capacitor 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 0.5 mm to 2 mm and a thickness of 0.05-0.15 mm;

[0037] The induction body support capacitor is connected to the U-shaped infrared capacitor plate and is located at both ends of the ceramic substrate;

[0038] The infrared sensor and the bracket capacitors are composed of asymmetric plate infrared sensor capacitors 5-1U and 5-2U;

[0039] The diffuser refracts or reflects the infrared signal passing through the infrared filter onto the capacitor plate of the induction body;

[0040] The infrared sensor capacitor and the sensor bracket capacitor constitute a capacitive PIR pyroelectric sensor;

[0041] The digital signal processing chip has an input end connected to the induction body bracket capacitor, and the induction control signal is output by 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, thereby 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 card, embedded in the top window of the metal shell, fixed by black resin glue, and encapsulated in the metal shell of the sensor;

[0045] The infrared filter adopts a coated single crystal silicon wafer to improve the infrared transmittance.

[0046] Preferably, wherein:

[0047] The diffuser has a semicircular groove on its surface, and the upper and lower pieces are deflected 90 degrees and combined together to form an interlaced corrugated reflective surface in the horizontal and vertical directions.

[0048] The spacing between 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 is a U-shaped symmetrical structure, with fingers 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 interdigital spacing of the U-shaped symmetrical structure is 0.2 mm to 0.8 mm to optimize the capacitance performance.

[0052] Preferably, wherein:

[0053] The U-shaped symmetrical capacitor plate is printed with a protective film underneath and sintered on a ceramic substrate;

[0054] The U-shaped symmetrical capacitor has a rectangular groove in the middle plate and semicircular grooves in the middle of the two side plates. Laser etching technology is used to form a precise microstructure to enhance mechanical strength and stability.

[0055] After the U-shaped symmetrical structure capacitor plate is polarized, it is welded to the inductive support capacitor through the 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 induction body support capacitor is rectangular, concave in the middle, and the electrodes at both ends are respectively connected to the infrared induction body capacitor plate and the auxiliary fixing end, and are welded on the ceramic substrate;

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

[0060] Preferably, wherein:

[0061] The digital signal processing chip is an 8-pin SMD package and is located directly below the ceramic plate forming the infrared sensor;

[0062] The signal pins can be used to set the signal trigger mode, sensing sensitivity and delay time of the sensing module through external circuits; the pins are gold-plated to improve corrosion resistance and conductivity;

[0063] The power pin, signal pin, 6-pin or 4-pin are connected to the external circuit through the metal base.

[0064] Preferably, wherein:

[0065] The manufacturing method and steps of the pyroelectric inductor of the sensor include:

[0066] Step 1: Grind the pyroelectric inductor ceramic powder, filter it with a 500-mesh steel mesh, and prepare the inductor slurry;

[0067] Step 2: Printing a conductive paste with a thickness of 0.5-12 μm on a ceramic plate to make in-body electrodes;

[0068] Step 3: Print the bottom protective film of the pyroelectric inductor on the ceramic and dry and cure at 160°C;

[0069] Step 4: Printing a pyroelectric inductor ceramic slurry with a thickness of 0.05-0.15 mm on the bottom protective film to form a U-shaped capacitor plate;

[0070] Step 5: Sintering the ceramic substrate of the pyroelectric inductor at a temperature of 1000°C-1200°C for 6 hours;

[0071] Step 6: Sputtering metal on the surface of the ∪-shaped capacitor plate to form a silver electrode;

[0072] Step 7: polarize the ceramic pyroelectric inductor, polarization temperature: 135°C, voltage: 1.5-6KV / mm, time: 5-10min;

[0073] Step 8: Make the inductor end electrodes and weld the inductor bracket capacitors;

[0074] Step 9: Laser cut the ceramic plate, clean the surface of the sensor, and form a pyroelectric ceramic sensitive unit chip;

[0075] Step 10: Solder the pyroelectric ceramic sensor chip to the circuit board, located in the center of the circuit board.

[0076] Preferably, wherein:

[0077] The edge of the metal shell cap brim has a positioning end, which is located in the center of the metal base device identification end;

[0078] The metal shell is welded and sealed in a closed environment, and a protective inert gas (such as argon or nitrogen) is simultaneously filled into the sensor;

[0079] The metal shell is made of anti-corrosion material to improve durability.

[0080] Preferably, wherein:

[0081] The circuit board is made of glass fiber or ceramic material, with a thickness of 0.1-1.6 mm, and is connected to the power pin and the signal pin;

[0082] The circuit board is provided with resistor and capacitor components, and the digital signal processing chip is located in the center of the circuit board;

[0083] The circuit board adopts a single-layer or multi-layer design to enhance electromagnetic compatibility and heat dissipation.

[0084] 3 Beneficial effects

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

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

[0087] 2. High stability: Adaptive temperature compensation circuit ensures stable performance under different ambient temperatures.

[0088] 3. Strong anti-interference ability: The digital chip and signal processing are inside the shielded shell, which has stronger anti-RF interference ability.

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

[0090] 5. Chip wide voltage, low power consumption: power supply voltage 1.2-5V, current 10uA. BRIEF DESCRIPTION OF THE DRAWINGS

[0091] Figure 1 This is one of the overall structural schematic diagrams of the human infrared sensor module of the present invention.

[0092] Figure 2 This is the second overall structural schematic diagram of the human infrared sensor module of the present invention.

[0093] Figure 3 It is a structural schematic diagram of the power supply and signal control pins of the present invention.

[0094] Figure 4 It is a schematic diagram of the position structure of the metal housing filter of the present invention.

[0095] Figure 5It is a structural schematic diagram of the diffuser of the human body infrared sensor module of the present invention.

[0096] Figure 6 It is a structural schematic diagram of the integrated position of the human body infrared sensor module assembly of the present invention.

[0097] Figure 7 It is a schematic structural diagram of the U-shaped infrared sensitive material of the present invention.

[0098] Figure 8 It is a schematic diagram of the internal structure of the human infrared sensor module of the present invention.

[0099] Fig. 9 The invention discloses a 6-pin packaging structure, an equivalent circuit and a circuit diagram for use of a human infrared sensor module.

[0100] Fig.10 The invention discloses a 4-pin packaging structure, an equivalent circuit and a circuit diagram for use of a human infrared sensor module.

[0101] Fig.11 The invention discloses a 3-pin packaging structure, an equivalent circuit and a circuit diagram for use of a human infrared sensor module.

[0102] Fig.12 It is a trigger mode and output level timing diagram of the human infrared sensor module of the present invention. DETAILED DESCRIPTION

[0103] See also Figure 1-Figure 12 , which is a specific embodiment of a human infrared sensing module described in this application.

[0104] The human infrared sensing module in this embodiment includes a metal shell 3, a metal shell brim edge positioning end 3-1, and 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, a signal output pin REL 1-4, a signal input pin ONE 1-1, a signal input pin SENS1-2, a signal input pin ONTIME 1-3, and a 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 bracket capacitors 5-1 and 5-2, a circuit board 4, a resistor and capacitor element 11, and a digital signal processing chip 12.

[0105] 1. Structure

[0106] The human infrared sensor module of the present invention mainly includes the following parts:

[0107] Metal housing and base: provide mechanical support and protection, while having good electromagnetic shielding performance.

[0108] Power pin and signal pin: connect to external circuit to realize power supply and signal transmission.

[0109] Infrared filter and diffuser: used to filter and disperse infrared signals respectively to improve sensing accuracy.

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

[0111] Inductor bracket capacitor: Connect the inductor capacitor to optimize capacitor performance.

[0112] Circuit board and digital signal processing chip: realize signal processing and intelligent control.

[0113] 2. Manufacturing method

[0114] The manufacturing method of the present invention comprises the following steps:

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

[0116] Printing a conductive paste with a thickness of 0.5-12 μm on a ceramic plate to make in-vivo electrodes for the sensor;

[0117] Print the bottom protective film of the pyroelectric inductor on the ceramic and dry and cure at 160℃;

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

[0119] Sintering the ceramic substrate of the pyroelectric inductor, temperature: 1000℃-1200℃, time: 6 hours;

[0120] Metal is sputtered on the surface of the U-shaped capacitor plate to form a silver electrode;

[0121] Polarize the ceramic pyroelectric inductor at a temperature of 135°C, a voltage of 1.5-6KV / mm, and a time of 5-10 minutes;

[0122] Make the inductor end electrodes and weld the inductor support capacitors;

[0123] Laser cut the ceramic plate, clean the surface of the sensor, and form a pyroelectric ceramic sensitive unit chip;

[0124] Solder the pyroelectric ceramic sensitive element chip on the circuit board, located in the center of the circuit board;

[0125] Rare earth element doping is introduced during the sintering process to improve the performance and stability of pyroelectric materials.

[0126] 3 Working Principle

[0127] The working principle of the present invention is as follows:

[0128] Infrared signal acquisition: The infrared filter and diffuser work together to guide the external infrared signal to the sensor capacitor plate.

[0129] Capacitance change detection: The capacitive PIR pyroelectric sensor composed of the infrared sensing body capacitance and the sensing body bracket capacitance detects the capacitance change and generates an electrical signal.

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

[0131] Temperature Compensation: Temperature compensation circuit ensures stable sensing performance at different ambient temperatures.

[0132] like Figure 1-Figure 11 As shown, the capacitive human infrared sensor module in this embodiment includes a metal shell 3, a metal shell brim edge positioning end 3-1, and 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, a signal output pin REL 1-4, a signal input pin ONE 1-1, a signal input pin SENS1-2, a signal input pin ONTIME 1-3, and a circuit board pad 1-2-1; an infrared filter 10, a light pass card 9, a diffuser 8, a ceramic substrate 6, U-shaped infrared sensor capacitors 7-1 and 7-2, sensor bracket capacitors 5-1 and 5-2, a circuit board 4, a resistor and capacitor element 11, and a digital signal processing chip 12. The specific positions and connection relationships of each component are as follows:

[0133] Metal housing 3: used to protect internal components and provide electromagnetic shielding.

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

[0135] Power 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 housing, used to filter light in non-infrared bands.

[0137] Diffuser 8: located below the infrared filter, used for refracting or reflecting infrared signals.

[0138] Ceramic substrate 6: carries U-shaped infrared sensitive material to form an infrared sensing body capacitor.

[0139] Induction body support capacitors 5-1 and 5-2: support the infrared induction body capacitors and electrically connect them.

[0140] Circuit board 4: digital signal processing chip 12, including resistor and capacitor components 11 and other necessary electronic components.

[0141] U-shaped infrared sensitive material:

[0142] like Figure 7 As shown, the U-shaped infrared sensitive material is sintered on the ceramic substrate 6 to form an infrared sensing body capacitor. The material width is 0.5mm to 2mm, the thickness is 0.05-0.15mm, and it is optimized to achieve the best performance. The U-shaped structure helps to increase the surface area of ​​the material, thereby enhancing the infrared absorption capacity. The sensing body bracket capacitor is connected to the U-shaped infrared capacitor body plate, located at both ends of the ceramic substrate, and the two bracket capacitors have the same capacitance. The symmetrical U-shaped infrared ceramic body and the bracket capacitor 5 form a new set of sensing capacitors 5-1U and 5-2U, so that the reversely connected capacitor plates have asymmetry to enhance the sensitivity of the sensing signal. The external infrared signal passes through the infrared filter through the diffuser 8 and refracts or reflects the infrared signal to the sensing body capacitor plate. The power supply of the human infrared sensing module is input by the 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 structure design:

[0144] 1. Metal shell 3 and base 2: The metal shell is made of anti-corrosion material, and an infrared filter and a diffuser are embedded in the top window, fixed by black resin glue and encapsulated in the sensor.

[0145] 2. Infrared filter 10: Use coated single crystal silicon wafer to improve infrared transmittance.

[0146] 3. Diffuser 8: There are semicircular grooves on the surface. The upper and lower pieces are deflected 90 degrees and combined together. The internal horizontal and vertical directions form staggered corrugated reflective surfaces with a spacing of 0.1mm to 0.5mm.

[0147] 4. Ceramic substrate 6 and inductive capacitors 5-1U and 5-2U: U-shaped infrared sensitive material is printed on the ceramic substrate and sintered to form an infrared inductive body with a finger spacing of 0.2 mm to 0.8 mm.

[0148] 5. Induction body bracket capacitor 5-1, 5-2: rectangular design, concave in the middle, electrodes at both ends are respectively connected to the infrared induction body capacitor plate and the auxiliary fixing end, and are welded on the ceramic substrate 6.

[0149] 6. Circuit board and digital signal processing chip 12: The circuit board 4 is made of glass fiber or ceramic material with a thickness of 0.1-1.6 mm, and is connected to the power pin and the signal pin; the 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 it with a 500-mesh steel mesh and prepare the inductor slurry.

[0152] 2. Make in-body electrodes: Print conductive paste with a thickness of 0.5-12μm on a ceramic plate.

[0153] 3. Printing bottom protective film: Print the bottom protective film of the pyroelectric inductor on the ceramic and dry and cure at 160℃.

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

[0155] 5. Sintering ceramic substrate: temperature 1000℃-1200℃, time 6 hours.

[0156] 6. Metal sputtering: silver electrodes are formed on the surface of the ∪-shaped capacitor plates.

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

[0158] 8. Welding electrodes: make the inductor end electrodes and weld the inductor bracket capacitor.

[0159] 9. Laser cutting and cleaning: cutting ceramic plates, cleaning the surface of the sensor, and forming pyroelectric ceramic sensitive unit chips.

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

[0161] like Figure 4 , Figure 6 As shown, the infrared filter 10 and the diffuser 8 are located on the upper and lower surfaces of the light pass card 9, embedded in the top window of the metal shell 3, 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 to reduce interference.

[0162] The infrared filter 10 uses a coated single crystal silicon wafer, which can significantly improve the transmittance of infrared rays, thereby improving the sensitivity of the sensor. The fixing method ensures that the filter and the diffuser will not shift or fall off during use, ensuring long-term stable working performance.

[0163] The external infrared signal is directly irradiated or reflected to the sensing capacitor 5-1U and 5-2U plates through the filter 10 and the diffuser 8. The sensing signal is input to the circuit board through the bracket capacitors 5-1 and 5-2, and is output by the digital signal processing chip 12 through the REL signal pin.

[0164] like Figure 5 As shown in the figure, the diffuser has semicircular grooves on its surface, and the upper and lower pieces are deflected 90° and combined together, forming staggered corrugated reflective surfaces in the horizontal and vertical directions. This changes the refraction angle of infrared rays on the ceramic inductive capacitor and improves the inductive sensitivity. The spacing of the corrugated reflective surfaces is 0.1mm to 0.5mm, which helps to improve the reception efficiency of infrared signals.

[0165] The design of semicircular grooves and corrugated reflective surfaces can effectively disperse and reflect infrared rays, increasing the sensor's ability to receive infrared rays from different directions. Appropriate spacing selection can optimize the reflection effect and ensure maximum signal reception. The composite structure enables the sensor to receive infrared signals at multiple angles, improving the detection range and accuracy.

[0166] like Figure 8 As shown, the infrared sensor capacitor is a U-shaped symmetrical structure, with fingers distributed in the center of the ceramic substrate 6, which effectively receives external incident signals. The two ends are reversely connected to the sensor bracket capacitor through the bottom electrode to offset the interference signal caused by changes in ambient temperature. The finger spacing of the U-shaped symmetrical structure is 0.2mm to 0.8mm. The ∪-shaped symmetrical structure and the specific finger spacing design can optimize the capacitor performance and improve the response speed and sensitivity of the sensor. The connection method of the bottom electrode ensures good contact between the capacitor and the circuit and enhances reliability. The symmetrical structure provides better mechanical support and reduces 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 structure capacitor plate and sintered on a ceramic substrate. The protective film is made of specific materials (such as silicon nitride or zirconium oxide) to improve durability and stability. The use of a protective film can prevent the capacitor from being affected by the external environment and extend its service life. The selection of specific materials improves corrosion resistance and mechanical strength. The U-shaped symmetrical structure capacitor has a rectangular groove in the middle plate, and there are semicircular grooves in the middle of the two side plates. The resistance of the ∪-shaped symmetrical structure capacitor plate after polarization is 160Q each, and it is welded to the inductor bracket capacitor through metal electrodes at both ends. The specific plate structure design can optimize the electric field distribution and improve the capacitor performance. The use of metal electrodes made of highly conductive materials ensures good electrical connection and reduces resistance.

[0168] like Figure 5-Figure 8 As shown, the inductor support capacitor is rectangular with a depression in the middle. The electrodes at both ends are respectively connected to the infrared inductor capacitor plate and the auxiliary fixed end, and are welded on the ceramic substrate 6. The inductor support capacitor 5-1 and 5-2 connection electrodes are made of highly conductive materials (such as copper or silver) to improve the reliability of the electrical connection. The rectangular structure and the depression in the middle design can adjust the inductor plate area and resistance value as needed, so that the inductor has higher sensitivity and reliability. The selection of highly conductive materials ensures low resistance connection and improves the reliability of signal transmission. The welding process ensures long-term stable electrical connection.

[0169] The digital signal processing chip 12 is an 8-pin SMD package, located directly below the ceramic plate that forms the infrared sensor, and is led out from the bottom of the metal base. It is arranged in a circle, and the distance from the pin to the center of the metal base is. The signal pin can set the signal trigger mode, sensing sensitivity and delay time of the sensing module through an external circuit. The pin is gold-plated to improve corrosion resistance and conductivity. The power pin, signal pin, 6-pin, 4-pin and 3-pin are connected to the external circuit through the metal base.

[0170] The functions of the digital signal processing chip include: chip voltage range 1.2-5V, power consumption 10uA, operating temperature -25-85°. The pin functions are: 1: OEN photoresistor enable terminal (20%-80% VDD); 2: SENS sensitivity pin (0-VDD); 3: ONTIME trigger delay time adjustment pin, 16 delay time selection; 4: REL sensor output pin, output TTL high and low level; 5: VSS power ground; 6: VDD sensor power supply pin. Human infrared sensor module, can provide accessories Fig. 9 , Attachment Fig.10 and attached Fig.11 Available in 3-pin, 4-pin and 6-pin packages.

[0171] The digital signal processing chip has built-in intelligent algorithms, high-precision AD signal processing, differential signal input method, strong anti-interference ability, and can analyze and filter background noise in real time to improve the accuracy and sensitivity of human body detection.

[0172] The chip uses two differential high input impedance input terminals as the sensor sensitive element input. The 16-bit high-precision AD converter converts the voltage signal generated by the sensitive element into a digital signal. The digital signal output by the AD converter is filtered through a secondary bandpass filter to effectively filter out low-frequency and high-frequency noise interference caused by various reasons. All signal processing is completed in the shielded tube shell, which has a stronger ability to resist radio frequency interference. The sensitivity threshold and timing time can be adjusted by an external voltage divider resistor. It has an illuminance sensor input terminal, which can control the sensor to work when the ambient illuminance is lower than the set illuminance.

[0173] Trigger mode functions:

[0174] like Fig.12 As shown in the figure, under normal detection conditions, when the infrared signal received by the sensor exceeds the internal trigger threshold, a counting pulse will be generated. After receiving 2 pulses within 4 seconds, the sensor REL pin will output a high level to indicate that there is a signal. In addition, as long as the received signal amplitude exceeds 5 times the trigger threshold, only one pulse is needed to trigger REL to output a high level. If the trigger signal is received continuously, the maintenance time of the REL high level will be delayed from the last effective trigger to the end of the delay time determined by the ONTIME terminal.

[0175] Sensitivity adjustment function:

[0176] like Figure 9-12 As shown in the figure, the SENS pin sets different voltages through an external resistor network to set the comparison thresholds of different signals. When grounded, the sensor comparison threshold is the lowest, and the sensor sensitivity is the highest, that is, the sensing distance may be the farthest; the input voltage exceeding 1 / 2VDD will select the maximum threshold, and the sensor sensitivity is the lowest, that is, the sensing distance may be the shortest. The sensing distance of the sensor is related to the voltage on the SENS pin, the Fresnel lens, and different sensitivity settings.

[0177] Delay time adjustment

[0178] like Fig. 9 -- Fig.12 As shown in the figure, the delay time is the duration of the sensor outputting a high level after reaching the comparison threshold. The input voltage of the ONTIME pin determines the time the REL pin maintains a high level after the sensor is triggered. Each time a trigger signal is received, the delay time will be recalculated. The delay time is 1-3000 seconds.

[0179] The manufacturing method and steps of the capacitive human infrared sensor module sensor of the present invention include:

[0180] Step 1: Grind the pyroelectric inductor ceramic powder, filter it with a 500-mesh steel mesh, and prepare the inductor slurry;

[0181] Step 2: Printing a conductive paste with a thickness of 0.5-12 μm on a ceramic plate to make in-body electrodes;

[0182] Step 3: Print the bottom protective film of the pyroelectric inductor on the ceramic and dry and cure at 160°C;

[0183] Step 4: Printing a pyroelectric inductor ceramic slurry with a thickness of 0.05-0.15 mm on the bottom protective film to form a U-shaped capacitor plate;

[0184] Step 5: Sintering the ceramic substrate of the pyroelectric inductor at a temperature of 1000°C-1200°C for 6 hours;

[0185] Step 6: Sputtering metal on the surface of the ∪-shaped capacitor plate to form a silver electrode;

[0186] Step 7: polarize the ceramic pyroelectric inductor, polarization temperature: 135°C, voltage: 1.5-6KV / mm, time: 5-10min;

[0187] Step 8: Make the inductor end electrodes and weld the inductor bracket capacitors;

[0188] Step 9: Laser cut the ceramic plate, clean the surface of the sensor, and form a pyroelectric ceramic sensitive unit chip;

[0189] Step 10: Solder the pyroelectric ceramic sensor chip to the circuit board, located in the center of the circuit board.

[0190] like Figure 1-Figure 8 As shown, the sensor metal shell 3 has a positioning end 3-1 on the brim, which is located in the center of the metal base device identification end 2-1. The metal shell is welded and sealed in a closed environment, and a protective inert gas (such as argon or nitrogen) is simultaneously filled into the sensor. The metal shell 3 is made of anti-corrosion material to improve durability. The design of the positioning end is convenient for installation and identification, ensuring the accuracy and consistency of the sensor during installation. Sealing and filling with inert gas can prevent internal components from moisture and oxidation, and extend the service life. The selection of anti-corrosion materials improves the durability of the shell and adapts to various harsh environments.

[0191] like Figure 5-Figure 8 As 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 pin and the signal pin; the digital signal processing chip 12 is located in the center of the circuit board, and adopts a low-noise design to improve the signal amplification effect; the circuit board adopts a single-layer or multi-layer design to enhance electromagnetic compatibility and heat dissipation performance. Selecting appropriate materials and thicknesses can ensure the mechanical strength and electrical properties of the circuit board. Glass fiber or ceramic materials have good insulation and heat resistance. Low-noise design can improve signal amplification effect and reduce noise interference. The position design of chip 12 is convenient for wiring and heat dissipation. Single-layer or multi-layer design can optimize electromagnetic compatibility and heat dissipation performance according to needs, ensuring that the sensor works stably in a complex electromagnetic environment.

[0192] It can be seen from the above embodiments that the present application has the following beneficial effects:

[0193] 1. High sensitivity: New ferroelectric ceramic composite materials and special microstructure processing significantly improve infrared absorption efficiency.

[0194] 2. High stability: Adaptive temperature compensation circuit ensures stable performance under different ambient temperatures.

[0195] 3. Strong anti-interference ability: The digital chip and signal processing are inside the shielded shell, which has stronger anti-RF interference ability.

[0196] 4. Simplified manufacturing process: Improved manufacturing methods increase production efficiency and product consistency.

[0197] 5. Chip wide voltage, low power consumption: power supply voltage 1.2-5V, current 10uA.

[0198] The above description shows and describes several preferred embodiments of the present application, but as mentioned above, for ordinary technicians in this field, the specific embodiments are only illustrative descriptions of the present invention. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concepts and technical solutions of the present invention, or the concepts and technical solutions of the present invention are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. A human infrared sensor module, comprising a metal shell, a metal base, a power pin, a signal pin, an infrared filter, a light pass card, a diffuser, a ceramic substrate, an infrared sensor capacitor, a sensor bracket capacitor, a circuit board and a digital signal processing chip, characterized in that: The inductor support capacitor 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 0.5 mm to 2 mm and a thickness of 0.05-0.15 mm; The induction body support capacitor is connected to the U-shaped infrared capacitor plate and is located at both ends of the ceramic substrate; The infrared sensor and the bracket capacitors are composed of asymmetric plate infrared sensor capacitors 5-1U and 5-2U; The diffuser refracts or reflects the infrared signal passing through the infrared filter onto the capacitor plate of the induction body; The infrared sensor capacitor and the sensor bracket capacitor constitute a capacitive PIR pyroelectric sensor; The digital signal processing chip has an input end connected to the induction body bracket capacitor, and the induction control signal is output by 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, thereby improving the accuracy and sensitivity of human body detection.

2. The human infrared sensor module according to claim 1, characterized in that: The infrared filter and diffuser are located on the upper and lower sides of the optical card, embedded in the top window of the metal shell, fixed by black resin glue, and encapsulated in the metal shell of the sensor; The infrared filter adopts a coated single crystal silicon wafer to improve the infrared transmittance.

3. The human infrared sensor module according to claim 1, characterized in that: The diffuser has a semicircular groove on its surface, and the upper and lower pieces are deflected 90 degrees and combined together to form an interlaced corrugated reflective surface in the horizontal and vertical directions. The spacing between 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 sensor module according to claim 1, characterized in that: The infrared sensor capacitor is a U-shaped symmetrical structure, with fingers distributed in the center of the ceramic substrate, and the two ends are connected to the sensor support capacitor through the bottom electrode; The interdigital spacing of the U-shaped symmetrical structure is 0.2 mm to 0.8 mm to optimize the capacitance performance.

5. The human infrared sensor module according to claim 1 or 4, characterized in that: The U-shaped symmetrical capacitor plate is printed with a protective film underneath and sintered on a ceramic substrate; The U-shaped symmetrical capacitor has a rectangular groove in the middle plate and semicircular grooves in the middle of the two side plates. Laser etching technology is used to form a precise microstructure to enhance mechanical strength and stability. After the U-shaped symmetrical structure capacitor plate is polarized, it is welded to the inductive support capacitor through the metal electrodes at both ends; The protective film is made of specific materials (such as silicon nitride or zirconium oxide) to improve durability and stability.

6. The human infrared sensor module according to claim 1, characterized in that: The induction body support capacitor is rectangular, concave in the middle, and the electrodes at both ends are respectively connected to the infrared induction body capacitor plate and the auxiliary fixing end, and are welded on the ceramic substrate; The inductor support capacitor connection electrodes are made of highly conductive materials (such as copper or silver) to improve the reliability of electrical connection.

7. The human infrared sensor module according to claim 1, characterized in that: The digital signal processing chip is an 8-pin SMD package and is located directly below the ceramic plate forming the infrared sensor; The signal pins can respectively set the signal trigger mode, sensing sensitivity and delay time of the sensing module through external circuits; The pins are gold-plated to improve corrosion resistance and electrical conductivity; The power pin, signal pin, 6-pin or 4-pin are connected to the external circuit through the metal base.

8. The human infrared sensor module according to claim 1, characterized in that: The manufacturing method and steps of the pyroelectric inductor of the sensor include: Step 1: Grind the pyroelectric inductor ceramic powder, filter it with a 500-mesh steel mesh, and prepare the inductor slurry; Step 2: Printing a conductive paste with a thickness of 0.5-12 μm on a ceramic plate to make in-body electrodes; Step 3: Print the bottom protective film of the pyroelectric inductor on the ceramic and dry and cure at 160°C; Step 4: Printing a pyroelectric inductor ceramic slurry with a thickness of 0.05-0.15 mm on the bottom protective film to form a U-shaped capacitor plate; Step 5: Sintering the ceramic substrate of the pyroelectric inductor at a temperature of 1000°C-1200°C for 6 hours; Step 6: Sputtering metal on the surface of the U-shaped capacitor plate to form a silver electrode; Step 7: polarize the ceramic pyroelectric inductor, polarization temperature: 135°C, voltage: 1.5-6KV / mm, time: 5-10min; Step 8: Make the inductor end electrodes and weld the inductor bracket capacitors; Step 9: Laser cut the ceramic plate, clean the surface of the sensor, and form a pyroelectric ceramic sensitive unit chip; Step 10: Solder the pyroelectric ceramic sensor chip to the circuit board, located in the center of the circuit board.

9. The human infrared sensor module according to claim 1, characterized in that: The edge of the metal shell cap brim has a positioning end, which is located in the center of the metal base device identification end; The metal shell is welded and sealed in a closed environment, and a protective inert gas (such as argon or nitrogen) is simultaneously filled into the sensor; The metal shell is made of anti-corrosion material to improve durability.

10. The human infrared sensor module according to claim 1, characterized in that: The circuit board is made of glass fiber or ceramic material, with a thickness of 0.1-1.6 mm, and is connected to the power pin and the signal pin; The circuit board is provided with resistor and capacitor components, and the digital signal processing chip is located in the center of the circuit board; The circuit board adopts a single-layer or multi-layer design to enhance electromagnetic compatibility and heat dissipation performance.

Images