DYNALAS
1. Technical Principle
Laser soldering with eutectic preform is a precision joining technology based on the properties of eutectic alloys, and its core mechanisms include:
- Eutectic reaction: Utilizes the characteristic of eutectic alloys (e.g., AuSn, CuSn) to melt and rapidly solidify at a specific temperature, achieving welding with low heat input and high bonding strength;
- Precise laser energy control: Locally heats the preformed solder sheet through high-energy-density laser pulses (with typical values of 10⁶–10¹² W/cm²), avoiding thermal damage to sensitive components (e.g., chips, MEMS devices) caused by overall temperature rise;
- Vacuum/controlled atmosphere protection: Suppresses oxidation in a vacuum or inert gas environment, reducing the weld porosity rate (<5%).
2. Process Flow
3.技术优势
| Indicator | Traditional Reflow Soldering | Laser soldering with eutectic preform | 提升幅度 |
|---|---|---|---|
| Heat Input | >200J/mm² | <50J/mm² | Reduce by 75% |
| Heat-Affected Zone (HAZ) | >100μm | <10μm | Reduce by 90% |
Porosity Rate | 10-30% | <5% | Reduce by 80% |
Minimum Solder Joint Size | 50μm | 10μm | Reduce by 80% |
Applicable Material Combinations | Same Metal | Dissimilar Metals (e.g., Cu-Au) | Expanded Application |
4. Typical Application Scenarios
① Microwave/RF Device Packaging
- Chip-substrate interconnection: Welding of GaAs chips to Kovar carriers reduces thermal resistance by 40%;
- Hermetic sealing: AuSn eutectic soldering achieves a leak rate of <1×10⁻⁸ atm·cc/s, meeting military standards.
② New Energy Battery Modules
- Battery-module connection: Laser welding of Aluminum-Copper dissimilar materials achieves a contact resistance of <0.1 mΩ and tensile strength of >200 MPa;
- Thermal management components: Cu-Ni eutectic solder preforms are used in heat dissipation substrates, increasing thermal conductivity to 400 W/(m·K).
③ Aerospace Microsystems
- MEMS sensor packaging: Laser welding of titanium alloy and ceramic substrate achieves a vibration fatigue life of >10⁷ cycles;
- Optical fiber coupling module: Bonding of InGaAs laser and silicon optical waveguide results in a coupling efficiency of >85%.
5. Future Trends
① Intelligent Upgrade
- Integrated machine vision for real-time positioning (accuracy of ±0.1μm);
- Adaptive learning algorithm optimizes welding parameters (response time <10ms).
② Expansion of New Materials
- Development of low-temperature eutectic alloys (e.g., Bi-In with a melting point of 60°C) for flexible electronics;
- Nanoparticle-reinforced solders (Ag nanoparticles enhancing thermal conductivity by 30%).
③ Green Manufacturing
- Lead-free eutectic alloys (e.g., Sn-Bi-Cu) compliant with RoHS standards;
- Energy consumption reduced by 50% (achieved by replacing continuous lasers with pulsed lasers).