Electroless deposition of high-uniformity nickel microbumps with ultrahigh resolution of 8 μm pitch for monolithic Micro-LED display
Journal article, 2024

Micro-light-emitting diode (Micro-LED) displays have attracted growing attention due to their unsurpassed properties that satisfy the requirements of reality/virtual reality (AR/VR) displays. A crucial procedure of monolithic integration technology in high-density microdisplays is the interconnection process, which is intimately associated with the quality of the display device. Microfluidic electroless interconnection (MELI), an innovative low-temperature and pressure-free chip-stacking approach that eliminates the warpage-induced issues and cracking damage of the chip caused by thermo-compression bonding (TCB), holds great promise as a technology for establishing interconnections between the CMOS driver and Micro-LED. However, the requirement for the consistency of the microbump arrays and the risk of creating bridges is significantly intensified with smaller gaps in stacked chips, which restricts the application range of MELI to high-density interconnects. This paper analyzes the feasibility of further lowering the stand-off height of stacked chips in ultrafine pitch interconnects by optimizing the bump preparation process. The plasma modification time and surfactant concentration during the bump preparation process have been investigated. The result indicated that microbump arrays with a uniformity of less than 3% could be successfully manufactured by employing a 7-min plasma treatment and incorporating optimal surfactants, which catalyzes the implementation of the subsequent vertical interconnection process and eventually enhances yields of Micro-LEDs.

Ultrafine pitch

High uniformity

Micro-LED display

Electroless plating

Ni microbumps

Author

Yu Lu

Fuzhou University

Chang Lin

Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China

Fuzhou University

Liang Tian

Fuzhou University

Shuaishuai Wang

Fuzhou University

Kaixin Zhang

Fuzhou University

Taifu Lang

Fuzhou University

Yang Li

Fuzhou University

Qiwei Li

Fuzhou University

Tianxi Yang

Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China

Zhonghang Huang

Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China

Jie Sun

Fuzhou University

Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Qun Yan

Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China

Fuzhou University

Materials Science in Semiconductor Processing

1369-8001 (ISSN)

Vol. 175 108263

Subject Categories

Other Materials Engineering

Other Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1016/j.mssp.2024.108263

More information

Latest update

3/14/2024