High Density Interconnection and Packaging Chemical Engineering in 21st Century

点击翻译按钮获取中文摘要

Electrodeposited bumps are the indispensable micro-connectors for high density interconnection in the latest microelectronics applications. For the higher frequency circuit, shorter interconnection length by bumps in required in order to reduce the reflection noise. Ball grid array (BGA) of solder bumps is necessary for high pin count chips in order to reduce the their packaging size. Bumps can also be used as a new testing method for bare chips of high pin counts. Another application is the interconnection between liquid crystal display (LCD) and driver chips, which are mostly interconnected with tape automated bonding (TAB). The bumps act as micro connectors of TAB technology and conduct digital signals from the chips to the LCD pixels.The bumps are electrodeposited onto the dot shaped cathode of 10 to 200μm in diam. The cathode, or photolithography patterns, are patterned by photomask and photoresist. The control of electrodeposited bump shape, as well as the uniformity in their height, is important for obtaining proper interconnection reliability.The research summarized three topics on shape evolution of bumping. The effect of high aspect ratio cavity for CSP and flip chip, the effect of additive and interference effect of neighbor bumps.Furthermore, we have organized the Packaging Process Engineering Division in the Society of the Chemical Engineering. Forty companies and ten university have already joined our division.