Low temperature and pressureless Cu-to-Cu direct bonding by green synthesized Cu nanoparticles

Die-Attach Bonding with Etched Micro Brass Metal Pigment Flakes for High-Power Electronics Packaging

“…The presence of Cu chlorides and Cu oxides in the flakes after etching is undesirable during sintering because Cu oxides are diffusion barriers and Cu chlorides have high melting points, over 400 °C, and do not decompose during the sintering process if at low temperatures, as in the present study. PEG600 was selected in the present study not only as a binding solvent but also as a reducing agent as it is known to have a reducing effect on Cu oxides. − Therefore, a reducing atmosphere like H 2 , forming gas, or formic acid-enriched N 2 was not necessary.…”

“…The developed binder mixture of α-terpineol and PEG600 allowed a predrying step at 120 °C Therefore, eqs and can take place. Moreover, PEG600 is known to have reducing effects on Cu oxides. − Two different reducing mechanisms are proposed: the reducing effect of Zn and the reducing effect of PEG600. However, with the low concentration of Zn in the flakes, the effect of PEG600 is dominating.…”

Study on the preparation of ascorbic acid reduced ultrafine copper powders in the presence of different protectants and the properties of copper powders based on methionine protection

“…1–5 Further conductive patterns with high uniformity and high electrical conductivity can be realized by printed electronics, which is considered to be the most promising alternative to silver in the future and has received widespread attention. 6–9 However, the smaller particle sizes, narrower distribution, higher activity, and easy oxidization pose inevitable limitations on the preparation and storage of the ultrafine copper powder particles. 10 Although various methods exist for preparing ultrafine copper powder particles including physical and chemical methods, wet chemical synthesis is considered to be the more desirable method for industrial applications due to its strong controllability of particle size morphology.…”