Capacitive PIR pyroelectric sensor

Abstract

The invention discloses a capacitive PIR pyroelectric sensor, which comprises a metal shell, a metal base, a power supply pin, a signal pin, an infrared filter, a light transmission clamping plate, a light diffusion sheet, a ceramic substrate, an infrared inductor capacitor, an inductor bracket capacitor, a circuit board and an MOS (Metal Oxide Semiconductor) tube, and is characterized in that the inductor bracket capacitor is provided with a rectangular ceramic substrate; a U-shaped infrared sensitive material is printed on the ceramic substrate, and an infrared inductor is formed through a sintering process; and the inductor and the support capacitor form an infrared inductor capacitor with an asymmetric polar plate structure. The light diffusing sheet refracts or reflects an infrared signal passing through the infrared filter to the inductor capacitance plate, a power supply of the PIR pyroelectric sensor is input through the power supply pin, and an infrared induction signal is amplified by the MOS tube and output through the middle signal pin. According to the capacitive PIR pyroelectric sensor provided by the invention, the sensitivity and reliability of the sensor are remarkably improved by optimizing the structure of the inductor, improving the manufacturing process and adopting the advanced packaging technology.

Description

Technical Field

[0001] The present invention relates to a capacitive PIR (passive infrared) pyroelectric sensor, and more particularly to a structural design and manufacturing method thereof. The sensor is suitable for use in the fields of security, smart home, etc., and is used to detect infrared radiation changes of a human body or other objects. Background Art

[0002] Existing PIR pyroelectric sensors have certain limitations in terms of sensitivity, signal processing and anti-interference capabilities. Traditional sensors usually use simple sensor structures and relatively rough manufacturing processes, resulting in unstable performance, especially in complex environments. In addition, the packaging method and material selection of existing sensors also affect their durability and reliability.

[0003] In order to solve the above problems, the present invention proposes a novel capacitive PIR pyroelectric sensor, which significantly improves the sensitivity and reliability of the sensor by optimizing the structure of the sensor, improving the manufacturing process and adopting advanced packaging technology. Summary of the invention

[0004] In order to solve the above technical problems, this application has the following technical solutions:

[0005] U-shaped infrared sensitive material: This material is sintered on a ceramic substrate to form an asymmetric plate infrared sensing capacitor (5-1U and 5-2U). The U-shaped material has a width of 0.5mm to 2mm and a thickness of 0.05-0.15mm, and is optimized for best performance.

[0006] Diffuser design: The diffuser is located below the infrared filter, which refracts or reflects the infrared signal passing through the filter to the sensor capacitor plate, significantly improving the reception efficiency of the infrared signal.

[0007] MOS tube amplifies the signal: MOS tube is used to amplify the infrared sensing signal and output it through the intermediate signal pin to ensure high-fidelity transmission of the signal.

[0008] Metal shell and inert gas packaging: The metal shell is welded and sealed in a closed environment, and the sensor is simultaneously filled with protective inert gas (such as argon or nitrogen) to improve the durability and stability of the sensor.

[0009] Ceramic substrate and capacitor structure: U-shaped infrared sensitive material is printed on the ceramic substrate to form a new asymmetric plate infrared sensor capacitor, and the two ends are connected through the bottom electrode and supported by the sensor bracket capacitor.

[0010] The present invention provides a capacitive PIR pyroelectric sensor, comprising the following components and features:

[0011] Metal casing: used to protect internal components and prevent external interference.

[0012] Metal base: supports the entire sensor and provides pin connections.

[0013] Power pins and signal pins: used to input power and output signals.

[0014] Infrared filter: Improves infrared transmittance and filters unnecessary light.

[0015] Light pass card board: fix the infrared filter and diffuser.

[0016] Diffuser: refracts or reflects the infrared signal passing through the infrared filter to the capacitor plate of the sensor.

[0017] Ceramic substrate: serves as the basis for the inductor support capacitor.

[0018] Infrared sensor capacitor: It is formed by sintering U-shaped infrared sensitive material on a ceramic substrate.

[0019] Induction body bracket capacitor: connected to the U-shaped infrared capacitor plate, located at both ends of the ceramic substrate.

[0020] Circuit board: connect the power pin and signal pin, and install MOS tube for signal amplification.

[0021] MOS tube: used to amplify infrared sensing signals.

[0022] Specific features:

[0023] The inductor support capacitor is provided with a rectangular ceramic substrate;

[0024] The ceramic substrate is printed with a U-shaped infrared sensitive material, which is sintered on the ceramic substrate to form an infrared sensor;

[0025] 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;

[0026] The induction body support capacitor is connected to the U-shaped infrared capacitor plate and is located at both ends of the ceramic substrate;

[0027] The infrared sensor and the bracket capacitors are composed of asymmetric plate infrared sensor capacitors 5-1U and 5-2U;

[0028] The diffuser refracts or reflects the infrared signal passing through the infrared filter onto the capacitor plate of the induction body;

[0029] The power supply of the PIR pyroelectric sensor is input through the power pin, and the infrared sensing signal is amplified by the MOS tube and output through the intermediate signal pin.

[0030] Preferably, wherein:

[0031] 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;

[0032] The infrared filter adopts a coated single crystal silicon wafer to improve the infrared transmittance.

[0033] Preferably, wherein:

[0034] 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.

[0035] 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.

[0036] Preferably, wherein:

[0037] 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;

[0038] The interdigital spacing of the U-shaped symmetrical structure is 0.2 mm to 0.8 mm to optimize the capacitance performance.

[0039] Preferably, wherein:

[0040] The U-shaped symmetrical capacitor plate is printed with a protective film underneath and sintered on a ceramic substrate;

[0041] The U-shaped symmetrical capacitor has a rectangular groove in the middle plate and semicircular grooves in the middle of the two side plates.

[0042] 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;

[0043] The protective film is made of specific materials (such as silicon nitride or zirconium oxide) to improve durability and stability.

[0044] Preferably, wherein:

[0045] 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;

[0046] The inductor support capacitor connection electrodes are made of highly conductive materials (such as copper or silver) to improve the reliability of electrical connection.

[0047] Preferably, wherein:

[0048] The power pins and signal pins are led out from the bottom of the metal base and arranged in a circle, and the distance from the pins to the center of the metal base is 2.54 mm;

[0049] The pins are gold-plated to improve corrosion resistance and electrical conductivity.

[0050] Preferably, wherein:

[0051] The manufacturing method and steps of the pyroelectric inductor of the sensor include:

[0052] Step 1: Grind the pyroelectric inductor ceramic powder, filter it with a 500-mesh steel mesh, and prepare the inductor slurry;

[0053] Step 2: Printing a conductive paste with a thickness of 0.5-12 μm on a ceramic plate to make in-body electrodes;

[0054] Step 3: Print the bottom protective film of the pyroelectric inductor on the ceramic and dry and cure at 160°C;

[0055] 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;

[0056] Step 5: Sintering the ceramic substrate of the pyroelectric inductor at a temperature of 1000°C-1200°C for 6 hours;

[0057] Step 6: Sputtering metal on the surface of the U-shaped capacitor plate to form a silver electrode;

[0058] Step 7: 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;

[0059] Step 8: Make the inductor end electrodes and weld the inductor bracket capacitors;

[0060] Step 9: Laser cut the ceramic plate, clean the surface of the sensor, and form a pyroelectric ceramic sensitive unit chip;

[0061] Step 10: Solder the pyroelectric ceramic sensor chip to the circuit board, located in the center of the circuit board.

[0062] Preferably, wherein:

[0063] 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;

[0064] 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;

[0065] The metal shell is made of anti-corrosion material to improve durability.

[0066] Preferably, wherein:

[0067] 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;

[0068] The MOS tube is located at the signal pin at the edge of the circuit board and adopts a low-noise design to improve the signal amplification effect;

[0069] The circuit board adopts a single-layer or multi-layer design to enhance electromagnetic compatibility and heat dissipation performance.

[0070] Beneficial Effects

[0071] In summary, due to the adoption of the above technical solution, the capacitive PIR pyroelectric sensor of the present invention has the following advantages:

[0072] 1. High sensitivity: By optimizing the sensor structure and material selection, the receiving efficiency of infrared signals is significantly improved.

[0073] 2. Stable signal processing: Using advanced signal amplification technology and anti-interference design to ensure the stability of signal processing.

[0074] 3. Reliable manufacturing process: Detailed manufacturing steps and parameter control ensure the high quality and consistency of the products.

[0075] 4. Durable packaging: The use of anti-corrosion materials and inert gas sealing improves the durability and reliability of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 It is one of the overall structural schematic diagrams of the capacitive PIR pyroelectric sensor of the present invention.

[0077] Figure 2 This is the second schematic diagram of the overall structure of the capacitive PIR pyroelectric sensor of the present invention.

[0078] Figure 3 It is a schematic diagram of the structure of the power supply and signal pins of the present invention.

[0079] Figure 4 It is a schematic diagram of the position structure of the metal housing filter of the present invention.

[0080] Figure 5 It is a structural schematic diagram of the capacitive PIR pyroelectric sensor diffuser of the present invention.

[0081] Figure 6It is a schematic structural diagram of the U-shaped infrared sensitive material of the present invention.

[0082] Figure 7 It is a schematic diagram of the internal structure of the capacitive PIR pyroelectric sensor of the present invention.

[0083] Figure 8 It is a schematic diagram of the inductive body capacitance structure of the capacitive PIR pyroelectric sensor of the present invention.

[0084] Fig. 9 The invention discloses a packaging structure, a signal processing circuit and an equivalent circuit diagram of the sensor. DETAILED DESCRIPTION

[0085] See also Figure 1-Figure 8 , which is a specific embodiment of a PIR pyroelectric sensor described in this application.

[0086] like Figure 1-Figure 8 As shown, the capacitive PIR pyroelectric sensor 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 1-1 and 1-3, circuit board pads 1-1-1 and 1-3-1; a signal pin 1-2, 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 and a MOS tube 11. The specific positions and connection relationships of each component are as follows:

[0087] Metal housing 3: used to protect internal components and provide electromagnetic shielding.

[0088] Metal base 2: Fixes the sensor and provides mechanical support.

[0089] Power pin and signal pin 1: used for input power and output signal respectively.

[0090] Infrared filter 10: installed at the top window of the metal housing, used to filter light in non-infrared bands.

[0091] Diffuser 8: located below the infrared filter, used for refracting or reflecting infrared signals.

[0092] Ceramic substrate 6: carries U-shaped infrared sensitive material to form an infrared sensing body capacitor.

[0093] Induction body support capacitors 5-1 and 5-2: support the infrared induction body capacitors and electrically connect them.

[0094] Circuit board 4: integrated signal processing circuit, including MOS tube 11 and other necessary electronic components.

[0095] U-shaped infrared sensitive material:

[0096] like Figure 5 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 induction 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 PIR pyroelectric sensor is input by the power pin 1-1, and the infrared sensing signal is amplified by the MOS tube 11 and output through the intermediate signal pin 1-2.

[0097] Capacitive PIR pyroelectric sensor structure design:

[0098] 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.

[0099] 2. Infrared filter 10: Use coated single crystal silicon wafer to improve infrared transmittance.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 6. Circuit board and MOS tube 11: The circuit board 4 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 MOS tube is located at the signal pin at the edge of the circuit board and adopts a low-noise design.

[0104] Infrared ceramic capacitor manufacturing method:

[0105] 1. Grind the pyroelectric inductor ceramic powder: filter it with a 500-mesh steel mesh and prepare the inductor slurry.

[0106] 2. Make in-body electrodes: Print conductive paste with a thickness of 0.5-12μm on a ceramic plate.

[0107] 3. Printing bottom protective film: Print the bottom protective film of the pyroelectric inductor on the ceramic and dry and cure at 160℃.

[0108] 4. Printing pyroelectric inductor ceramic slurry: forming a U-shaped capacitor plate with a thickness of 0.05-0.15mm.

[0109] 5. Sintering ceramic substrate: temperature 1000℃-1200℃, time 6 hours.

[0110] 6. Metal sputtering: Silver electrodes are formed on the surface of the U-shaped capacitor plates.

[0111] 7. Polarization treatment: polarization temperature 135℃, voltage 1.5~6KV / mm, time 5-10min.

[0112] 8. Welding electrodes: make the inductor end electrodes and weld the inductor bracket capacitor.

[0113] 9. Laser cutting and cleaning: cutting ceramic plates, cleaning the surface of the sensor, and forming pyroelectric ceramic sensitive unit chips.

[0114] 10. Welding chip: Weld the pyroelectric ceramic sensitive element chip to the circuit board, located in the center of the circuit board.

[0115] 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.

[0116] 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.

[0117] The external infrared signal is directly irradiated or reflected by the filter 10 and the diffuser 8 to the sensing capacitor 5-1U and 5-2U plates. The sensing signal is input to the circuit board through the bracket capacitors 5-1 and 5-2, and is amplified by the MOS tube 11 and output to the signal pin 1-2.

[0118] 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.

[0119] 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.

[0120] 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 the change in ambient temperature. The finger spacing of the U-shaped symmetrical structure is 0.2mm to 0.8mm. The U-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.

[0121] 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 middle plate of the U-shaped symmetrical structure capacitor has a rectangular groove, and there are semicircular grooves in the middle of the two side plates. The resistance of the U-shaped symmetrical structure capacitor plate after polarization is 160Ω 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 capacitance performance. The use of metal electrodes made of highly conductive materials ensures good electrical connection and reduces resistance.

[0122] like Figure 8 , Figure 7As 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.

[0123] like Figure 8 , Figure 7 As shown in the figure, the power pin 1-1 and signal pin 1-2 of the sensor are led out from the bottom of the metal base and arranged in a circular pattern. The distance from the pin to the center of the metal base is 2.54mm. The circular arrangement of the pin design can simplify installation and wiring, and facilitate automated production. Gold plating can effectively prevent pin corrosion and ensure long-term and reliable electrical connection. The standardized pin spacing (2.54mm) meets industry standards and is easy to be compatible with other devices.

[0124] The present invention provides a method and steps for manufacturing a capacitive PIR pyroelectric sensor inductor, including:

[0125] Step 1: Grind the pyroelectric inductor ceramic powder, filter it with a 500-mesh steel mesh, and prepare the inductor slurry;

[0126] Step 2: Printing a conductive paste with a thickness of 0.5-12 μm on a ceramic plate to make in-body electrodes;

[0127] Step 3: Print the bottom protective film of the pyroelectric inductor on the ceramic and dry and cure at 160°C;

[0128] 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;

[0129] Step 5: Sintering the ceramic substrate of the pyroelectric inductor at a temperature of 1000°C-1200°C for 6 hours;

[0130] Step 6: Sputtering metal on the surface of the U-shaped capacitor plate to form a silver electrode;

[0131] Step 7: 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;

[0132] Step 8: Make the inductor end electrodes and weld the inductor bracket capacitors;

[0133] Step 9: Laser cut the ceramic plate, clean the surface of the sensor, and form a pyroelectric ceramic sensitive unit chip;

[0134] Step 10: Solder the pyroelectric ceramic sensor chip to the circuit board, located in the center of the circuit board.

[0135] like Figure 1 , Figure 2 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.

[0136] like Figure 5-Figure 8 As shown, the sensor circuit board 4 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 MOS tube 11 is located at the signal pin at the edge 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. MOS tubes with low-noise design can improve signal amplification effects and reduce noise interference. The position design of the MOS tube 11 is convenient for wiring and heat dissipation. The 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.

[0137] It can be seen from the above embodiments that the present application has the following beneficial effects:

[0138] 1. High sensitivity: By optimizing the sensor structure and material selection, the receiving efficiency of infrared signals is significantly improved.

[0139] 2. Stable signal processing: Using advanced signal amplification technology and anti-interference design to ensure the stability of signal processing.

[0140] 3. Reliable manufacturing process: Detailed manufacturing steps and parameter control ensure the high quality and consistency of the products.

[0141] 4. Durable packaging: The use of anti-corrosion materials and inert gas sealing improves the durability and reliability of the sensor.

[0142] 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 capacitive PIR pyroelectric sensor, comprising a metal housing, a metal base, a power pin, a signal pin, an infrared filter, a light pass card, a diffuser, a ceramic substrate, an infrared induction body capacitor, an induction body bracket capacitor, a circuit board and a MOS tube, 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 power supply of the PIR pyroelectric sensor is input through the power pin, and the infrared sensing signal is amplified by the MOS tube and output through the intermediate signal pin.

2. The capacitive PIR pyroelectric sensor 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 capacitive PIR pyroelectric sensor 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 capacitive PIR pyroelectric sensor 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 capacitive PIR pyroelectric sensor 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. 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 PIR pyroelectric sensor 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 capacitive PIR pyroelectric sensor according to claim 1, characterized in that: The power pins and signal pins are led out from the bottom of the metal base, arranged in a circle, and the distance from the pins to the center of the metal base is 2.54 mm; The pins are gold-plated to improve corrosion resistance and electrical conductivity.

8. The capacitive PIR pyroelectric sensor 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 capacitive PIR pyroelectric sensor 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 capacitive PIR pyroelectric sensor 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 MOS tube is located at the signal pin at the edge 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.

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