N6 precision nickel wire semiconductor bonding wire

1. Overview

N6 precision nickel wire is an ultra-fine, ultra-high-precision nickel-based alloy wire designed for semiconductor packaging bonding and military-grade microelectronic devices. Its core characteristics include purity ≥99.99%, diameter tolerance ±0.005mm, ultra-low surface roughness (Ra≤0.1μm) and excellent conductivity-strength balance, which is widely used in chip wire bonding, high-reliability sensors, aerospace micro-connections and other scenarios, and is the "invisible skeleton" in the field of precision electronics manufacturing.

2. Chemical composition and material characteristics

N6 nickel wire is based on high-purity electrolytic nickel (Ni≥99.99%), and the performance is optimized through strict impurity control

• 微量元素限制：碳（C）≤0.005%、硫（S）≤0.002%、氧（O）≤10ppm，避免晶界脆化与电迁移风险。
• Material Properties:
• High conductivity: Conductivity ≥ 15% IACS (for high-frequency signal transmission).
• Corrosion resistance: no oxidation and discoloration for 1000h in 85°C/85%RH humid and hot environment.
• Thermal stability: The coefficient of linear expansion in the range of -196°C~+350°C ≤13×10⁻⁶/°C, suitable for semiconductor thermal cycling conditions.

3. Physical and mechanical properties

1. Physical properties
2. Diameter range: 0.015–0.500mm (military grade up to 0.010mm±0.002mm).
3. Density: 8.90–8.92 g/cm³.
4. Melting Point: 1453–1455 °C.
5. Mechanical properties (take 0.025mm diameter as an example).
6. Tensile strength: 600–1000 MPa (adjustable, suitable for different bonding processes).
7. Elongation: 8–15% (to ensure fatigue resistance at the bonding point).
8. Fracture toughness: bending radius ≤ 0.1mm without breaking.

Fourth, the manufacturing process

The production of military-grade N6 nickel wire needs to break through the triple technical barriers of "ultra-fine, ultra-fine and ultra-clean":

1. Ultra-high purity smelting:
2. 真空电子束熔炼（EBM）结合区域熔炼（Zone Refining），杂质总量≤50ppm。
3. Nanoscale brushing:
4. Multi-mode diamond wire drawing die step by step reduction (single pass diameter reduction rate ≤10%), with real-time feedback from the online laser caliper, the tolerance control ± 0.005mm.
5. Surface Treatment:
6. 电解抛光（EP）去除微米级划痕，表面粗糙度Ra≤0.1μm；
7. Inert gas annealing (Ar/H₂ mixture) relieves internal stresses and improves ductility.
8. Clean Packaging:
9. Class 100 clean room rolling, vacuum anti-static packaging, particle contamination ≤ 0.1 pcs/m³.

Fifth, the field of application

1. Semiconductor packaging
2. Chip bonding wire: Replace gold wire for power devices (IGBT, SiC modules), reduce cost by 40% and improve conductivity;
3. 倒装焊（Flip Chip）：微凸点（Microbump）填充材料，适配5nm以下制程。
4. Military electronics
5. Radar TR component: high-frequency signal transmission line, phase stability ≤ 0.1°;
6. Aerospace sensors: radiation-resistant wires (resistant to 1×10⁶ Gy γ rays);
7. Fuze microconnection: anti-shock vibration (≥ 5000g acceleration does not fail).
8. Biomedical
9. Implantable electrode leads (ISO 10993 biocompatible certified)

6. Standards and certifications

• International standards: ASTM F72 (high purity nickel wire), MIL-DTL-24697C (military electronic wire).
• Chinese Standard: GB/T 5235-2020 (precision nickel and nickel alloy wire), GJB 548B (military specification for microelectronic devices).
• Industry certifications: IATF 16949 (Automotive Electronics), NADCAP (Aerospace Special Processes).
• Major manufacturers: TE Connectivity of the United States, Tanaka Precious Metals of Japan, and Powder Metallurgy Research Institute of Central South University of China.

7. Technological challenges and innovation directions

1. Breakthrough of extreme precision
2. Development of sub-micron nickel wire (diameter ≤0.005mm) to meet the packaging needs of quantum chips;
3. Research on atomic layer deposition (ALD) coating technology to achieve nanoscale insulation/anti-oxidation coatings.
4. Intelligent process upgrades
5. Artificial intelligence-driven dynamic optimization of wire drawing parameters (real-time control of tension and temperature);
6. Machine vision online defect detection (recognition rate≥ 99.99%).
7. Green manufacturing
8. Closed-circuit electrolyte circulation system reduces the discharge of heavy metal wastewater by 90%;
9. Hydrogen energy reduction replaces carbon thermal reduction and reduces CO₂ emissions

8. Summary

With the characteristics of "ultra-pure, ultra-precise and ultra-stable", N6 precision nickel wire has become a key medium connecting the microscopic electronic world and macroscopic functional devices. In the strategic context of semiconductor localization and independent and controllable military industry, its manufacturing technology continues to move towards atomic-level precision and intelligent production, and in the future, it may open up new application dimensions in cutting-edge fields such as 6G communication and brain-computer interface, and reshape the precision boundary of high-end manufacturing.