Directional transfer and low-temperature interconnect packaging of nano metal materials

Purpose This paper aims to systematically review the directional transfer and low-temperature interconnect packaging of nano metal materials, analyze their sintering mechanism, transfer methods and interconnection performance, overcome the reliability bottleneck of traditional interconnection materials in high-temperature and high-power environments and promote their application in three-dimensional integrated packaging and high-density packaging. Design/methodology/approach Through literature review and analysis, the sintering mechanism of nanometal materials is sorted out, and the reported transfer technologies, including magnetron sputtering, pulsed laser deposition, liquid bridge transfer, micro-contact printing, selective wetting and electrohydrodynamic jet printing, are compared and investigated in terms of transfer accuracy, pattern resolution and interconnection performance. Findings Nano metal can be sintered at low temperature to form high-strength interconnection structures with high electrical and thermal conductivity and high-temperature resistance due to the small size effect and high surface activity. Different transfer techniques exhibit different performance in terms of resolution, uniformity and alignment accuracy, among which magnetron sputtering and pulsed laser deposition are suitable for high-coverage deposition, while liquid bridge transfer and selective wetting are suitable for patterned transfer. Originality/value This review provides a systematic comparison and performance evaluation of directional transfer and low-temperature interconnect packaging of nano metal materials, points out the limitations of current transfer technologies in terms of precision, efficiency and reliability and proposes that future research should focus on process optimization, defect control and the study of multi-physical field coupling mechanisms, providing theoretical support and technical references for high-density interconnect packaging.