密封电子元器件与装置多余物检测发展综述

As critical components in aerospace systems, sealed electronic components and devices have high precision, reliability, and complexity. One of the major variables affecting their high reliability is the issue of loose remainders, which are almost impossible to avoid altogether. Therefore, mitigating the impact of loose remainders is necessary. With the rapid development of aerospace technology, loose remainder detection techniques have been improved and refined. This paper comprehensively discusses preventive and control methods, detection techniques, and detection standards for loose remainders. Moreover, future competitive points, challenges, and prospects for PIND (particle impact noise detection) products and technologies are presented. Firstly, the definition of loose remainders from external sources is introduced. Loose remainders can be categorized into macroscopic and microscopic loose remainders by size. The preliminary classification is introduced according to historical aerospace events that led to launch delays or failures by loose remainders. The main categories are loose remainders remaining or obstructing internal engine pipes, loose remainders causing inadequate sealing or valve closure, and loose remainders leading to electrical control failures. Secondly, the paper focuses on preventing and controlling loose remainders. There are three approaches for controlling and preventing loose remainders: (1) Cause-and-effect diagram representation; (2) Discovery and trace-back investigation methods; (3) Control process and functional integration methods. Five methods are often used to detect loose remainders: microscopic inspection, radiographic inspection, MATRA inspection, particle impact noise detection (PIND) method, and direct extraction and identification method. The history and development of the PIND method is discussed from the detection aspects of small-sized components and medium-to-large-sized devices. With increasing demands and specialized applications, intelligent detection data algorithms, high reliability of products, diverse functionalities, and customization have become new competitive points. Furthermore, innovation and development in loose remainder detection technologies are crucial. Finally, standards and future development related to loose remainders and the PIND method are discussed. An overview loose remainder detection's overall status and future development is presented.