行波管折叠波导慢波结构UV-LIGA制备技术中的电铸工艺  

Electroforming Process for Preparation of TWTs Folded Waveguide Slow-Wave Structure Using UV-LIGA Technology

作　　者：谢云竹 姜琪 李兴辉[1] 潘攀[1] Xie Yunzhu;Jiang Qi;Li Xinghui;Pan Pan(National Key Laboratory of Science and Technology on Vacuum Electronics,The 12th Research Institute,China Electronics Technology Group Corporation,Beijing 100015,China)

机构地区：[1]中国电子科技集团公司第十二研究所微波电真空器件国家级重点实验室,北京100015

出　　处：《微纳电子技术》2023年第11期1850-1856,共7页Micronanoelectronic Technology

基　　金：国家自然科学基金重点项目(61831001)。

摘　　要：UV-LIGA是制作行波管(TWT)折叠波导慢波结构的一项重要技术,能够满足行波管对于慢波结构小尺寸、高精度和低表面粗糙度的加工要求。简要介绍了采用UV-LIGA技术制备340 GHz折叠波导慢波结构的工艺流程,主要包括在铜基底上通过光刻工艺制备厚胶膜结构、在厚胶膜结构中进行高精度电铸以及将半封闭铜电铸窄通道中胶膜去除等。对大深度窄缝结构精密电铸工艺进行了详细研究,分析对比脉冲波及三角波的电铸结果,优化工艺参数并尝试工艺组合。结果表明,采用三角波电铸,狭缝和胶膜边缘厚度差为40μm;采用脉冲波和三角波电铸结合方法,得到的电铸结构表面平整,狭缝和胶膜边缘厚度差减小至15μm。最终制备的折叠波导慢波结构与基底结合良好,表面无缺陷,高温处理后无裂纹、无鼓泡,窄边尺寸精度优于2μm,能够满足行波管的应用需求。UV-LIGA is an important technology for the preparation of folded waveguide slowwave structures in traveling wave tubes(TWTs),and can meet the processing requirements of slow-wave structures for small size,high accuracy and low surface roughness.The fabrication process of 340 GHz folded waveguide slow-wave structure using UV-LIGA technology was briefly introduced.The main processes include the preparation of thick photoresist film structures on copper substrate by the photolithography process,high precision electroforming in thick photoresist film structures,and the removal of photoresist film from semi-closed narrow channels in copper electroforming structures.The precision electroforming process of large depth and narrow slit structures was researched in detail.The electroforming results of pulse wave and triangular wave were analyzed and compared.The process parameters were optimized and process combination was attempted.The results indicate that the thickness difference of the slit structure and the photoresist film edge is 40μm by triangular wave electroforming.By combining pulse wave electroforming and triangle wave electroforming,the surface of the electroforming structure is flat and the thickness difference of the slit structure and the photoresist film edge can be reduced to 15μm.The final prepared folded waveguide slow-wave structure is well combined with the substrate,and there are no defects on the surface,no cracks and bubbles after high temperature treatment,and the narrow side dimensional accuracy is better than 2μm,which can meet the application requirements of TWTs.

关 键 词：UV-LIGA工艺 行波管(TWT) 折叠波导 直流电铸 脉冲波电铸 三角波电铸 

分 类 号：TN305[电子电信—物理电子学] TH703[机械工程—仪器科学与技术]