卫星展开机构用热刀切割器大气失效机理分析

Atmospheric Failure Mechanism of Thermal Knife Used in Satellite Deployment Components

目的分析图案化电阻Pt薄膜在大气环境下使用寿命下降的原因。方法基于此,选取现有型号热刀切割器图案化电阻薄膜,制备不同厚度Pt/Ti膜,重点考察大气环境下薄膜表界面形貌、成分、晶体结构随温度的变化规律及其对电阻率特性以及力学性能影响。结果大气高温下,Ti过渡层从底层扩散至表面与Pt形成合金,部分Ti扩散至表面被氧化,合金化与氧化导致薄膜电阻率先升高后降低。同时,充当Pt薄膜与基底之间“黏合剂”的Ti过渡层扩散耗尽,导致Pt薄膜与氮化硅基底结合力降低。结论以上因素最终导致了图案化薄膜热刀大气高温环境下切割寿命下降。

The work aims to analyze the reasons for the decrease in service life of patterned resistive Pt thin films in atmospheric environments.Based on this,existing models of patterned resistance films of thermal knives were selected to prepare Pt/Ti films with different thickness.The changes of surface morphology,composition and crystal structure of the films with temperature in the atmospheric environment and their effects on resistivity and mechanical properties were investigated.It was found that at high atmospheric temperature,the Ti transition layer diffused from the bottom to the surface to form alloys with Pt,and part of Ti diffused to the surface to be oxidized,resulting in the trend of first increase and then decrease of the film resistance.At the same time,the Ti transition layer acting as the"adhesive"between the Pt film and the substrate,was exhausted by diffusion,resulting in a decrease in the binding force between the Pt film and the silicon nitride substrate.The above factors ultimately lead to the reduction in the cutting life of the thermal knife with patterned films as the core when used at high temperature in the atmospheric environment.