多通道红外中长波芯片与双透镜集成组件封装技术

Multi⁃Channel Infrared Medium Long Wave Chip and Dual⁃Lens Integrated Component Packaging Technology

多光谱红外探测技术能丰富遥感载荷的图像信息,提高图像的反演精度,而多透镜和多波段探测器集成封装设计能缩小光学载荷体积,同时节约制冷资源。针对多波段探测器和低温光学透镜集成封装的特点,本文设计并研制了一种双透镜和多波段探测器集成的气密性封装组件结构。以航天某项目用多波段中长波红外组件为研究对象,对多波段中长波红外组件探测器的不同焦平面光学配准、低温滤光片支撑结构、透镜高精度光学配准和低温形变控制、防串扰和背景辐射杂散光抑制等进行了研究。通过3个红外焦平面拼接并与3波段滤光片和双透镜高精度光学配准、深低温下低形变的滤光片支架结构设计、透镜低温形变控制和组件低背景的杂散光抑制等关键技术,使组件的3波段不同焦平面探测器拼接精度优于±5μm,焦平面探测器与滤光片和透镜的光学配准精度偏差分别优于±8μm和±15μm,滤光片支架和透镜在低温下的形变得到改善,多波段间光谱串扰优于6%,串音低于5%,组件研制性能满足系统的光学成像质量和电学性能设计要求。研制后的组件通过1500 h老练试验以及鉴定级随机和正弦力学振动,已成功搭载载荷运用于某项目的光谱成像仪中。本文研究结果解决了多波段探测器与多透镜集成化封装中的高精度配准、低形变滤光片支撑、透镜光学配准和低温形变控制、防光学串扰和杂散光抑制等一系列问题。

Objective With the rapid development of infrared detection technology,it has been widely employed in medical,environmental,climate and meteorological monitoring,and space remote sensing.In comparison to traditional detection technology,infrared technology can be applied to complex and dynamic scenarios.For instance,it can be adopted to detect the complex marine environment and climate via ocean water color observation satellites.However,data acquired by infrared remote sensing satellites can be affected by factors like atmosphere and terrain to result in the inclusion of non-target imaging information and ultimately influence the accuracy of detection results.Meanwhile,satellites are being developed with hyperspectral,high spatial resolution,and high sensitivity capabilities to ensure high-precision observation in space remote sensing technology.The integration of multi-band and multi-channel infrared detection technology has emerged as a development trend to improve the retrieval accuracy of remote sensing satellite images.The packaging of multi-band infrared focal plane technology is crucial for the practical application of multi-band and multi-channel infrared detection technology.Additionally,the lens is often integrated with the infrared focal plane package in the same airtight component to minimize the size of the optical system and optimize the utilization of refrigeration resources,which puts forward higher packaging requirements.Therefore,we present a novel technology for the integrated packaging of multi-band and dual-lens components.Methods We focus on a multi-band mid-long wave infrared module employed in an aerospace project.Firstly,the pixel arrangement of the detector and the optical registration control technology of different focal planes are introduced(Fig.1).The structural design of the multi-band and dual-lens integrated package components is then explained(Fig.2).Meanwhile,we explore the low-deformation filter support design(Fig.3)and filter bonding process to minimize low-temperature deformation.Spectral crosstalk and spectral response of the components are calculated using tested spectral curves(Fig.4).The lens deformation under force and heat is analyzed separately(Fig.5),and a method for controlling the lens deformation is proposed(Fig.6).Additionally,the influence of lens deformation on the imaging quality of the optical system is compared under three different cases(Tables 1 and 2),with the analysis of stray light from the component background radiation is conducted(Fig.7).Finally,the packaging techniques lead to a package component with exceptional performance(Fig.8 and Table 4).Results and Discussions Based on the above analysis,our innovation can be categorized into three main aspects.Firstly,we focus on different focal plane splicing technology and optical registration.By utilizing fine-tuning technology for different focal planes of multi-channel infrared detectors and adjusting the coaxial lens,the accuracy deviation of the three-band detector with different focal planes and filters is improved to within±5μm,while the registration of the lens and detector is within±15μm.The results demonstrate that the spectral crosstalk is better than 6%,the spectral response is greater than 99%,and the electrical performance indicates a crosstalk lower than 5%.Secondly,we present a low-deformation filter bracket design and bonding process.Typically,the filter bracket and filter are bonded using adhesive,which inevitably leads to contact between the coating area near the edge of the filter and the glue,and thus forms a bonding surface.Additionally,the thermal properties of the filter substrate differ from those of the filter support material,causing the filter film layer to experience thermal stress when operating at low temperatures.Experimental results indicate that thermal mismatch-induced stress can alter the spectral characteristics of the filter,resulting in spectrum deformation.To mitigate low-temperature deformation of the filter bracket,we employ an alloy material with a low expansion coefficient for the filter bracket and add an isolation slot at the edge of the filter.Furthermore,the filter is fixed at both ends of the filter support frame using low-temperature resistant glue,with strict control over the applied amount of glue.These measures significantly improve the low-temperature deformation of the filter bracket.Finally,a technique for adjusting the image quality of an optical system is investigated by studying the deformation of the lens at low temperature under different inflation pressures.The assembled system is degassed using a vacuum and filled with N_(2) protective gas.The results reveal that by adjusting the pressure of N_(2),it is possible to improve the deformation of the lens center and the optical imaging quality for a small field of view.Our study introduces a novel approach to adjusting the imaging quality of optical systems.Conclusions An infrared package module integrating a multi-channel infrared detector and lens is designed and developed.The module focuses on key technologies such as multi-band splicing of different focal planes,control of optical lens profile and coaxial registration,low deformation control of the filter bracket,and suppression of anti-light string and stray light background radiation.The splicing accuracy of the three-band focal plane detector is better than±5μm,while the optical registration accuracy deviation between the focal plane detector and the filter and lens is better than±8 and±15μm respectively.The deformation of the filter bracket and lens is improved at low temperatures,and the effect of lens deformation on optical imaging quality can be disregarded.Optical crosstalk is kept below 6%,and the crosstalk itself is less than 5%.Our study successfully tackles the challenges of achieving high precision registration for multi-band and dual-lens integrated infrared detector assembly,low deformation control of the filter bracket,lens surface profile control,and the miniaturization and high performance of the crosstalk detector package.