Bromine- and Chlorine-Induced Degradation of Gold-Aluminum Bonds
Authors: Lue, Min-Hsien; Huang, Chen-Town; Huang, Sheng-Tzung; Hsieh, Ker-Chang
Source: Journal of Electronic Materials, Volume 33, Number 10, 1 October 2004 , pp. 1111-1117(7)
Abstract:The presence of bromine (Br) in flame retardant epoxies accelerates the degradation of gold-aluminum wire bonds. This experiment tests degradation by adding 5 wt.% 2,6-dibromophenol to the regular molding compound and holding thermal aging at 175°C and 205°C in ovens for up to 1,008 h. The intermetallic degrading microstructure was examined at different aging times. In order to better understand the mechanism behind the degradation, bulk Au4Al and Au5Al2 single-intermetallic phases were prepared and reacted with molding compound at 205°C. The reactions were analyzed by a JEOL (Japan Electron Optics Ltd., Tokyo) Superprobe JXA-8900R under wavelength-dispersive spectrometry of x-ray mode. A similar chloride degrading study was performed by adding Tetrachlorobisphenol A to the regular molding compound. The results show that Br attacked the Au4Al phase first and then the Au5Al2 phase. The chloride reacted with the Au4Al phase only.
Document Type: Research Article
Publication date: October 1, 2004