Thick film pyroelectric sensitive element and preparation method thereof

Abstract

The invention belongs to the technical field of electronic materials and components, and particularly relates to a thick film pyroelectric sensitive element and a preparation method thereof. The thick film pyroelectric infrared sensitive element comprises a top electrode, a heat sensitive layer and a bottom electrode. The top electrode is used as a common electrode, and the thickness of the infrared radiation absorbing surface of the top electrode is 10-500 nm. The heat sensitive layer is arranged between the top electrode and the bottom electrode and is prepared by compounding pyroelectric ceramic powder and organic pyroelectric polymers, and the thickness of the heat sensitive layer is 1-100 um. The bottom electrode is used for leading out pyroelectric response signals, and the thickness of the bottom electrode is 10 nm to 1 um. According to different types of pyroelectric infrared sensitive element, the top electrode and the bottom electrode of the infrared sensitive element are imaged. The thick film pyroelectric sensitive element is applied to safety burglary prevention, human body detection and the like in the civilian field. The thick film pyroelectric sensitive element has the advantages of being good in thermal insulation effect, more sensitive to weak environment temperature change, higher in sensitivity, simple in manufacturing technology, low in cost, capable of facilitating batch processing and beneficial to industrialization production.

Description

technical field [0001] The invention belongs to the technical field of electronic materials and components, and more specifically relates to a pyroelectric infrared sensitive component and a preparation method thereof. Background technique [0002] Pyroelectric infrared detector is a heat-sensitive detector designed according to pyroelectric effect, which converts infrared radiation signal into electrical signal, because it works at room temperature without refrigeration, low power consumption, light weight, and wide spectral response range , easy imaging, and high cost performance have become one of the current research hotspots in the field of infrared detection technology. As the core component of infrared detection technology, pyroelectric infrared detectors have been widely used in various security and anti-theft, human detection, etc. in the civilian field, various thermal sights, guided missiles, etc. Heat leakage and corrosion, and even disease diagnosis in the medi...

AI Technical Summary

Problems solved by technology

The first single crystal forms such as triglyceride sulfate (TGS) and lithium tantalate (LiTaO 3 ) etc. have high pyroelectric coefficients and high sensitivity, but the cost of single crystal materials is high and the manufacturing process is difficult

The second type is ceramic blocks prepared by thinning technology, such as barium strontium titanate (BST), etc. Although ceramic devices have good pyroelectric performance, ceramic sensitive components not only have high requirements for thinning technology, but also because ceramics Sensitive components have large heat capacity, which leads to a significant decrease in device performance, especially high-frequency performance

The third type of ceramic film type, such as lead zirconate titanate (PZT) and lead lanthanum titanate (PLT), reduces the heat capacity of the device through the use of thin film technology, and has the characteristics of excellent performance and fast response speed. However, the film deposition conditions and device The compatibility of micromachining technology is poor, and the performance of the device is greatly affected by the thermal insulation structure

The structure of the thermal insulation layer is mostly porous SiO 2 , Polyimide PI and other low thermal conductivity materials are set between the substrate and the heat sensitive element to reduce the longitudinal conduction of heat; this structure is relatively simple, but there are steps between the multilayer structures, metal interconnections Process compatibility is not high, and it is not easy to achieve full integration of devices

The microbridge structure and the air gap structure are to remove the non-sensitive element part (such as the substrate, etc.) of the device through various etching methods (such as wet etching, dry etching) to form a heat insulation structure. Although the heat insulation effect is good, However, the production cost is high, the process is complicated, and the mechanical shock resistance is weak.

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