Surface metallization of PTFE and PTFE composites by ion implantation for low-background electronic substrates in rare-event detection experiments  

作　　者：Shao-Jun Zhang Yuan-Yuan Liu Sha-Sha Lv Jian-Ping Cheng Bin Liao Pan Pang Zhi Deng Li He 

机构地区：[1]College of Nuclear Science and Technology,Beijing Normal University,Joint Laboratory of Jinping Ultra-low Radiation Background Measurement of Ministry of Ecology and Environment Beijing Normal University,Key Laboratory of Beam Technology of Ministry of Education,Beijing Normal University,Beijing,100875,China [2]Beijing Radiation Center,Beijing,100875,China [3]Department of Engineering Physics,Key Laboratory of Particle and Radiation Imaging of Ministry of Education,Tsinghua University,Beijing,100084,China [4]Joint Research Center,Nuctech Company Limited,Beijing,100084,China

出　　处：《Nuclear Science and Techniques》2022年第7期37-47,共11页核技术（英文）

基　　金：supported by the National Natural Science Foundation of China(Nos.12141502 and 12005017).

摘　　要：Polytetrafluoroethylene(PTFE)is a low-background polymer that is applied to several applications in rare-event detection and underground low-background experiments.PTFE-based electronic substrates are important for reducing the detection limit of high-purity germanium detectors and scintillator calorimeters,which are widely applied in dark matter and 0υββdetection experiments.The traditional adhesive bonding method between PTFE and copper is not conducive to working in liquid nitrogen and extremely low-temperature environments.To avoid adhesive bonding,PTFE must be processed for surface metallization owing to the mismatch between the PTFE and copper conductive layer.Low-background PTFE matrix composites(m-PTFE)were selected to improve the electrical and mechanical properties of PTFE by introducing SiO_(2)/TiO_(2) particles.The microstructures,surface elements,and electrical properties of PTFE and m-PTFE were characterized and analyzed following ion implantation.PTFE and m-PTFE surfaces were found to be broken,degraded,and cross-linked by ion implantation,resulting in C=C conjugated double bonds,increased surface energy,and increased surface roughness.Comparably,the surface roughness,bond strength,and conjugated double bonds of m-PTFE were significantly more intense than those of PTFE.Moreover,the interface bonding theory between PTFE and the metal copper foil was analyzed using the direct metallization principle.Therefore,the peel strength of the optimized electronic substrates was higher than that of the industrial standard at extremely low temperatures,while maintaining excellent electrical properties.

关 键 词：Surface modification Polytetrafluoroethylene Ion implantation Surface metallization Low temperature resistance 

分 类 号：TQ317[化学工程—高聚物工业] TB332[一般工业技术—材料科学与工程]