How to Control Working Temperature and Time in Laser Solder Paste Welding?

How to Control Working Temperature and Time in Laser Solder Paste Welding?

日期：2025-05-20    

Factors Affecting the Optimal State of Laser Solder Paste

  The optimal temperature and duration for laser solder paste are crucial for welding quality. Our experiments and research show that the ideal temperature and time depend on multiple factors, including the composition of the solder paste, the type and thickness of materials being welded, and environmental conditions.

  For most common solder pastes，the optimal working temperature range for laser soldering is typically between 200°C and 250°C. Within this range, the solder paste maintains good fluidity, ensuring complete wetting of the welding surface and formation of a uniform solder layer. If the temperature is too low, the fluidity of the solder paste deteriorates, potentially leading to weak joints or cold soldering defects. Conversely, if the temperature is too high, excessive volatilization of the solder paste may occur, generating fumes and harmful gases that can compromise the working environment and operator safety.

Finished Product Illustration of Solder Paste Welding for Digital Accessories Back Cable Flexible PCB

  Secondly, the welding duration is another critical factor affecting welding quality. Generally speaking, the welding time should be determined based on the thickness of the materials being welded and the wettability of the laser solder paste. For thinner materials, the laser welding time can be relatively shorter to avoid excessive heating that may cause material deformation or charring. For thicker materials, however, a longer laser welding time is required to ensure the solder paste can fully penetrate into the material and form a robust welded connection.

  When selecting the optimal temperature and duration, the requirements of the laser welding process must also be considered. For instance, in the case of precision electronic devices or micro-components, the laser must maintain an extremely small heat-affected zone during welding to prevent thermal damage to surrounding components. Therefore, under such circumstances, it is necessary to opt for lower welding temperatures and shorter welding times, coupled with precise laser control to ensure welding accuracy and reliability.

  For different brands and models of laser solder paste, the optimal temperature and duration may also vary. Hence, in practical applications, the ideal temperature and time must be determined based on the specific solder paste specifications and experimental results. Additionally, strict control over the storage and usage of the solder paste is essential to ensure its performance stability and reliability.

SMD Capacitor Laser Solder Paste Welding Animation

  Additionally, attention must be paid to the impact of the welding environment on quality. Environmental factors such as air humidity, ambient temperature, and wind speed may affect solder paste volatilization and welding performance. Therefore, during laser welding operations, strict environmental control is essential to ensure process stability and reliability.

Songsheng Optoelectronics Laser Constant-Temperature Soldering System

The system integrates three core technologies:

1. Real-time temperature feedback system

2. CCD coaxial alignment system

3. Semiconductor laser unit

Featuring a proprietary PID online temperature regulation system, it achieves:

• Precise constant-temperature soldering control

• Real-time high-precision temperature monitoring (±1°C)

• Exceptional soldering yield (99.95% @3σ) and repeatability

Ideal Applications:

• Temperature-sensitive micro-components:

o    Micro speakers/motors

o    Precision connectors

o    Electronic modules

o    Camera assemblies

Technical Advantages:

• 15μs ultra-fast temperature response

• Adaptive power adjustment (10-500W)

• Non-contact thermal measurement (IR sensor)

Conclusion

  Determining optimal laser solder paste parameters (temperature/duration) requires comprehensive evaluation of multiple variables. Only through continuous process optimization and practical verification can operation-specific parameters be established to ensure consistent, reliable soldering quality.

Furthermore, ongoing research into advanced soldering technologies and materials remains essential to address increasingly complex and diversified industrial requirements.