The study of micro-scale Cu Metallization on flexible interposer

• Main Authors: Kia-Wei Yang, 楊凱為
• Other Authors: Yu-Jung Huang
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/kwt332

碩士 === 義守大學 === 電子工程學系 === 104 === The ever-increasing market for portable electronic devices has resulted in an equally heavy demand for flexible substrate, flexible copper clad laminate (FCCL) being among the most popular. A typical FCCL construction includes a polyimide (PI) substrate, a thin metal tiecoat, a copper seedcoat, and a layer of electrodeposited copper. The low Cu/PI interface reliability is due to the fact that Cu cannot form a strong chemical bond with the constituent elements of the PI. In order to improve the interface adhesion strength, an additional tiecoat metal layer is generally deposited at the Cu/PI interface. Tiecoat materials include chromium and monel, a nickel based alloy. The purpose of the copper seedcoat is to provide sufficient electrical conductivity to permit electroplating to final copper thickness. For surface patterning on FCCL, it is usually performed by using photolithography and wet etching of the Cu layer. In order to fabricate flexible microelectronic devices, fabrication of metallization lines and metal electrodes on the flexible substrate is essential. For minimizing the size of device, the realization of metallization lines with the scale of a few micrometers on the flexible substrate is very important. In this study, pulse electroplating has been applied in order to metalize PI surfaces with Cu. The micro-scale fine patterns (<50μm) Cu metallization processes on PI substrate is described.