Processing and Properties of Single-Crystal Copper Wire.

The effects of drawing parameters and annealing process on the properties and microstructure of single crystal copper wire are studied using a wire-drawing machine, heat-treatment equipment, microcomputer-controlled electronic universal tester, resistance tester, and scanning electron microscope. The results show that, after drawing the single-crystal copper wire with a single-pass deformation of 14%, the grains elongate along the tensile direction, tensile strength increases from 500.83 MPa to 615.5 Mpa, and resistivity changes from 1.745 × 10-8 Ω·m to 1.732 × 10-8 Ω·m. After drawing at a drawing rate of 500 m/min, the degree of grain refinement increases and tensile strength increases from 615.5 Mpa to 660.26 Mpa. When a copper wire of Φ0.08 mm is annealed, its tensile strength decreases from 660.26 Mpa to 224.7 Mpa, and elongation increases from 1.494% to 19.87% when the annealing temperature increases to 400 °C. When the annealing temperature increases to 550 °C, the tensile strength and elongation decrease to 214.4 MPa and 12.18%, respectively.

Research Progress of Palladium-Plated Copper Bonding Wire in Microelectronic Packaging.

Wire-bonding technology is the most commonly used chip interconnection technology in microelectronic packaging. Metal bonding wire is the key material for wire bonding and plays an important role in the reliability of electronic devices. In recent years, palladium-plated copper (PdCu) bonding wire has been widely used because of its low cost, good electrical and thermal conductivity, the fact that it is not easy to oxidize, and its high reliability. Therefore, it is necessary to review its research progress. In this paper, the preparation and application of palladium-plated copper bonding wire are reviewed. Firstly, the preparation methods of electroplating, electroless plating, and direct plating are introduced. Secondly, the factors affecting the distribution of Pd in free air balls and bonding interfaces, the effect of Pd on the formation and growth of intermetallic compounds in PdCu wire, stitch bond, and reliability of PdCu wire are summarized and analyzed in the application process. Finally, its development prospect is prospected. Hopefully, this review can help readers to have a comprehensive understanding of the preparation and application of palladium-plated copper bonding wires, and can accelerate the promotion of its application in more fields in the future.

Study on the Effect of Cold Deformation and Heat Treatment on the Properties of Cu-Ag Alloy Wire.

The effects of various drawing parameters and annealing processes on the structure and properties of Cu-Ag wires, containing 1 wt% silver, were investigated using specialized equipment including fine wire-drawing machines, very fine wire-drawing machines, heat treatment equipment, tensile testing machines, microcomputer-controlled electronic universal testers, resistance testers, and scanning electron microscopes. The results revealed that continuous drawing of Cu-1%Ag alloy wires led to elongation of the grains, resulting in a uniform and tightly fibrous microstructure. Moreover, the tensile strength of the alloy wire increased from 670 MPa to 783.9 MPa after a single pass with a deformation of 14%. Subsequently, when the wire was drawn at a speed of 500 m/min, the tensile strength further increased to 820.1 MPa. After annealing the Փ0.08 mm Cu-1% Ag alloy wire, an increase in annealing temperature up to 500 °C resulted in the wire's tensile strength decreasing from 820.1 MPa to 377.5 MPa. Simultaneously, the elongation increased from 1.94% to 15.21%, and the resistivity decreased from 1.931 × 10-8 Ω·m to 1.723 × 10-8 Ω·m. Additionally, when annealing was conducted at a rate of 80 m/min, the wire resistivity dropped to 1.635 × 10-8 Ω·m.