Here is the abstract you requested from the IMAPS_2007 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|The Resin Core Bump Technology for COG Application|
|Keywords: Advanced Packaging, Fine Pitch Flip Chip, COG|
|COG technology has been widely used to LCD modules over 20 years. In accordance with higher definition in LCD, the conventional COG technology, with electro-plated gold bumps and ACF interconnection, is hard to achieve ultra fine pitch interconnections less than 20um pitches, because of its bump structure and interconnection principals. We developed the Resin Core Bump structure and its interconnection technology for COG applications. Especially it is designed using NCF, the Resin Core Bump is free from conductive particle shortage problem. The bump structure consists resin core and thin film electrode. The resin core has the same function that the conductive particles are in ACF. Using thin film electrode, it has ultra fine pitch capability up to 10um pitch. In addition, it is designed to have the compatibility of conventional bonding facilities. The bondability to glass substrate is investigated with 40um pitch test sample. The contact resistance of individual interconnects is measured using the four-point probe method in 13 point in a chip. The electrical measurement results show 42% of the conventional COG structure and its uniformity resulted in 27%. Interconnection reliabilities of thermal cycle and electrical migration test are investigated. In a thermal cycle test (from -40 to 85 deg. C), the contact resistivity of conventional structure raises 38ohm, but the Resin Core Bump structure raises 3ohm maximum. The Resin Core Bump technology enables ultra fine pitch interconnection and gives excellent reliability for the LCD modules.|
|Shuichi Tanaka, Assistant Manager
Seiko Epson Corporation
Suwa-gun, Nagano 399-0295,