Electroless Deposition of 4 μm High Ni/Au Bumps for 8 μm Pitch Interconnection
Journal article, 2022
We propose that electroless plating is a superb approach to preparing metallic bumps with an ultrafine pitch for the integration of a micro light-emitting diode (micro-LED). Electroless plating does not suffer from lift-off-related issues, which are ubiquitous in thermal evaporation. Besides, it can result in much more uniform bumps than electroplating because the bump height is not affected by the current distribution. This study reports ultrafine pitch Ni/Au bumps fabricated by electroless nickel immersion gold (ENIG) plating. Furthermore, cheap metals iron and nickel are selected to catalyze the electroless nickel process. The results indicate that uniform and consistent Ni/Au bumps can be obtained through the iron sheet and nickel layer method. Besides, no voids and impurities are found inside the bumps, which is beneficial for the following interconnection process. Moreover, the change in Ni bump height values with the electroless plating time is also provided.
interconnection
activation
ultrafine pitch
electroless plating
Ni/Au bumps
Author
Liang Tian
Fuzhou University
Chang Lin
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Fuzhou University
Kui Pan
Fuzhou University
Yu Lu
Fuzhou University
Liying Deng
Fuzhou University
Zhonghang Huang
Fuzhou University
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Tianxi Yang
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Fuzhou University
Yongai Zhang
Fuzhou University
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Jie Sun
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Fuzhou University
Qun Yan
Rich Sense Electronics Technology Co.
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Fuzhou University
ACS Applied Electronic Materials
26376113 (eISSN)
Vol. 4 10 4966-4971Subject Categories
Other Physics Topics
Metallurgy and Metallic Materials
Condensed Matter Physics
Areas of Advance
Materials Science
DOI
10.1021/acsaelm.2c00974