Oxidation resistant copper die-bonding material for metal joining in semiconductor devices

An oxidation-resistant copper-based microelectronic joining paste comprising:

• 10-60% copper metal particles;
• 30-80% copper nanoparticles;
• 10-20 wt % solvents;
• 0.1-5 wt % additives;
• wherein the copper metal particles include flake-shaped copper particles, spherical-shaped copper particles, plate-shaped copper particles, or a combination thereof;
• wherein the copper nanoparticles are subdivided into a first group and a second group, the first group comprises copper nanoparticles having particle sizes in a range of 10 nm to 80 nm, and the second group comprises copper nanoparticles having particle sizes in a range of 100 nm to 200 nm;
• and
• wherein the solvent comprises both amino and hydroxyl functional groups as anti-agglomeration agent and reducing agent for preventing oxidation of copper nanoparticles.