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AuIn Alloy
Gold-Indium (AuIn) Alloy
A high-reliability solder alloy combining gold's exceptional conductivity with indium's ductility for advanced electronic applications.
The AuIn alloy is engineered for high-performance interconnects and advanced packaging. Typically composed of approximately 80% gold and 20% indium, it exhibits a melting point of around 450°C, very low electrical resistivity, and excellent thermal conductivity.
| Property | Value | Notes |
|---|---|---|
| Composition | Au ~80%, In ~20% | Eutectic ratio for superior conductivity and reliability |
| Melting Point | ~450°C | High enough for robust applications |
| Electrical Resistivity | ~10 µΩ·cm | Low resistivity for high-performance circuits |
| Thermal Conductivity | ~150 W/m·K | Efficient heat dissipation |
| Mechanical Strength | ~30 MPa | Offers enhanced durability for interconnects |
Conceptual 3D Microstructure
A simplified 3D model showing alternating clusters of gold and indium atoms.
Applications
High-Reliability Interconnects
Provides robust electrical and thermal connections in advanced circuits.
Advanced Packaging
Supports miniaturization and high-density integration in electronic assemblies.
Medical Devices
Enables reliable interconnects in critical biomedical equipment.
Aerospace Electronics
Used in high-reliability assemblies for advanced aerospace applications.
Element Breakdown
Symbol: Au
Atomic Number: 79
Key Role in AuIn: Provides superior electrical conductivity and corrosion resistance.
Fun Fact: Gold is one of the best electrical conductors known.
Symbol: In
Atomic Number: 49
Key Role in AuIn: Imparts ductility and helps form a reliable eutectic bond.
Fun Fact: Indium's softness makes it ideal for flexible electronic connections.
Performance Comparison: Melting Point
Comparison of melting points among popular solder alloys. The AuIn alloy's ~450°C melting point provides excellent reliability in high-temperature applications.
Advantages Over Traditional Solders
| Property | 63Pb/37Sn (Lead-Based) | SAC (Lead-Free) | AuIn Alloy | Bi-Sn |
|---|---|---|---|---|
| Melting Point (°C) | 183 | 217 | 450 | 138 |
| Electrical Resistivity (µΩ·cm) | 20 | 15 | 10 | -- |
| Thermal Conductivity (W/m·K) | 35 | 60 | 150 | -- |
| Mechanical Strength (MPa) | 26 | 40 | 30 | -- |
Manufacturing & Production
The AuIn alloy is produced by melting high-purity gold and indium under controlled conditions to achieve the eutectic composition. Although its high melting point requires specialized processing, it delivers outstanding conductivity and reliability for advanced interconnects.
Safety & Handling
- Molten AuIn must be handled with appropriate protective gear to avoid burns.
- Work in well-ventilated areas and follow standard safety protocols during processing.
- Gold and indium are relatively non-toxic; however, proper handling is still required.