Investigation of Electrical Properties and Reliabilities of Chip-on-Glass（COG）with Compliant Bumps

• Main Authors: Chung Kuang Lin, 林宗寬
• Other Authors: Chih Chen
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/63069413656528339922

碩士 === 國立交通大學 === 材料科學與工程系所 === 95 === Non conductive film（NCF）is widely adopted by flat panel display（FPD）industry in chip-on-glass（COG）bonding method it provides low processing temperature and low product cost. As revealed by four-point test, the contact resistances of bumps subjected to six thermal cycles between 30~100oC raised form 1.6 to 2.5Ω, which is lower than 5Ω as require by the reliability standard. The resistance increment is largely resulted form the change of contact resistance. For the COG joint subjected to thermal storage test at 80 oC for 1000hours, the resistance raises from 0.48 to 1.26Ω while in the sample, the resistance raises from 0.73 to 1.52Ω; all test results fit the reliability requirements. But the reason of increment is not only NCF material degradation cause, but also the bump is elastically. Therefore elastic bump resile caused the resistance to increase after pressing. Consequently I used another two samples which is not thermal aging compared to test samples, the results were show bump resistances increasing about 65%, its come form elastic bumps itself. The best current stressing of COG was 65mA at room temperature. The failure position took place in aluminum wire on glass. Observed the resistance to decrease in 45mA, may be the contact was perfectly between Au surface and ITO after temperature increasing. The resistances of NCF of COG were above 109Ω all accorded with reliability range after 85 oC 85% humidity and 30V or 40V bias test. The resistance of NCF sometimes increased and decreased may be cased by NCF absorbing vapor or the resistance of measurement is higher than instrumental analysis. Therefore the increase or decrease of resistances of NCF was caused possibility by instrumental noise.