Investigations on the Anisotropically Conductive Adhesive for Flip-Chip Technology

• Main Authors: Wei-Liang Chen, 陳偉亮
• Other Authors: Kwang-Lung Lin
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/95566415443611010109

碩士 === 國立成功大學 === 材料科學及工程學系 === 88 === This work focus on the process of flip-chip technology using anisotropically conductive adhesive(ACA). A water pump was applied to produce a flux remove the bubble and thus obtain a smooth electroless deposition. ACA material has been investigated by scanning electronic microscopy(SEM). Energy dispersive spectroscopy(EDS) analysis reveals that ACA consists of nickel particle and spherical silica particle. It was found that 5 Vol% nickel particle and more than 70 Vol% silica are dispered in epoxy matrix. Silica can improve the characteristic of CET and moisture absorption. Differential scanning calorimetry(DSC) and thermogravimetry analysis(TGA) were used to characterize the thermal behavior of ACA. The nickel particle was seen to be deformed and contact with electrode during bonding process. At the same time, the cured epoxy of ACA protects the metallic contact from mechanical damage. The results indicate that the bare circuit might be electrically short, when bump height is 11μm because of the over-lap nickel particle. The bump coated with 1μm thickness of electroless gold can promote bonding condition to degrade the effect of the fine silica between the electrode and nickel particle. The result of high temperature, high humidity test at 85℃-85RH for 400hours reveals that moisture absorption of the ACA reduces the resistance. It also results in poor adhesion.