Bump-Fabrication Technologies for Micro-LED Display: A Review
Review article, 2025
Micro Light Emitting Diode (Micro-LED) technology, characterized by exceptional brightness, low power consumption, fast response, and long lifespan, holds significant potential for next-generation displays, yet its commercialization hinges on resolving challenges in high-density interconnect fabrication, particularly micrometer-scale bump formation. Traditional fabrication approaches such as evaporation enable precise bump control but face scalability and cost limitations, while electroplating offers lower costs and higher throughput but suffers from substrate conductivity requirements and uneven current density distributions that compromise bump-height uniformity. Emerging alternatives include electroless plating, which achieves uniform metal deposition on non-conductive substrates through autocatalytic reactions albeit with slower deposition rates; ball mounting and dip soldering, which streamline processes via automated solder jetting or alloy immersion but struggle with bump miniaturization and low yield; and photosensitive conductive polymers that simplify fabrication via photolithography-patterned composites but lack validated long-term stability. Persistent challenges in achieving micrometer-scale uniformity, thermomechanical stability, and environmental compatibility underscore the need for integrated hybrid processes, eco-friendly manufacturing protocols, and novel material innovations to enable ultra-high-resolution and flexible Micro-LED implementations. This review systematically compares conventional and emerging methodologies, identifies critical technological bottlenecks, and proposes strategic guidelines for industrial-scale production of high-density Micro-LED displays.
dip soldering
ball mounting
Micro-LED
electroplating
photosensitive conductive polymers
bump fabrication
electroless plating
evaporation
high-density interconnects
Author
Xin Wu
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Fuzhou University
Xue Qi Zhu
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Fuzhou University
Shuaishuai Wang
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Fuzhou University
Xuehuang Tang
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Fuzhou University
Taifu Lang
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Fuzhou University
Victor Belyaev
State University of Education
Aslan Abduev
State University of Education
Alexander Kazak
State University of Education
Chang Lin
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Fuzhou University
Qun Yan
Fuzhou University
Jie Sun
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Fuzhou University
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Materials
19961944 (eISSN)
Vol. 18 8 1783Subject Categories (SSIF 2025)
Other Electrical Engineering, Electronic Engineering, Information Engineering
Energy Engineering
Other Materials Engineering
DOI
10.3390/ma18081783