QLSn4020 is a high-quality, preformed tin-based solder preform. It is particularly suitable for formic acid reflow or vacuum soldering processes, offering simple and highly efficient operation. It features excellent wetting properties, resistance to thermal cycling, and high-low temperature shock characteristics, making it ideal for large-area soldering between AMB substrates and heat sinks.
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Indicators
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Performance
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Test Method
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| Appearance | Silver-gray | Silver-gray |
| Melting Temperature | 215-220℃ | |
| Density | 7.4g/cm3 | |
| Hardness | 35VHN | |
| Resistivity | 14 μΩ·cm | |
| Wetting Angle | 35° | |
| Surface Tension | 490 | 260℃/N2 |
| Tensile Strength | 86 MPa | Cylindrical tensile specimen (φ 5 mm), 1mm/min strain rate |
| Elongation | 17% | |
| Coefficient of Thermal Expansion | 19.7*10-6/℃ |
• Preformed solders feature high purity, low impurity content, uniform microstructure, and no segregation.
• Simple processing technology with low void ratio after soldering.
• Excellent wetting properties and refined microstructure of solder joints.
• Outstanding resistance to thermal cycling and high‑low temperature shock.
• Superior crack propagation resistance and stable interfacial microstructure.
