Laser Soldering process in the Application of LDS Capacitor Welding

Laser Soldering process in the Application of LDS Capacitor Welding

LDS (Laser Direct Structuring) is a process that deposits metal on plastic surface to form precise circuits, widely used in the field of electronic manufacturing. This technology enables the sealing and protection of components with complex geometric shapes without the need of chemical solvents or treatments, ensuring no surface damage. The LDS process can directly create fine dimensional conductive structures, antennas, switches, connectors, and sensors, thereby achieving miniaturization and lightweight design.

Illustration of LDS Chip Capacitor Soldering

A special structural requirement involves closely spaced soldering areas on both sides, requiring the chip capacitor to bridge and simultaneously solder to both circuit terminals. The solder fillets on both sides of the capacitor must be uniform, and the substrate must remain free from thermal damage.

Since the LDS-printed plating layer is only a few tens of microns thick and the underlying plastic cannot withstand high temperatures, traditional methods such as manual soldering or hot-bar soldering cannot ensure precise temperature control or high yield. Therefore, a ow-temperature solder paste constant – temperature soldering process must be employed for this welding application.

Animated GIF of Chip Capacitor Solder Paste Welding Process

The fundamental principle of laser solder paste welding involves dispensing solder paste onto predefined welding areas using a jetting system, followed by concentrating laser energy through an optical system to rapidly melt the solder paste. The molten solder then forms a strong bond with the soldering materials before cooling and solidifying into a reliable solder joint.

This process requires precise control of laser energy and focal positioning to ensure consistent and high-quality solder joints.

Illustration of Songsheng Optoelectronics Automatic Solder Paste Dispensing & Constant-Temperature Laser Soldering System

Features of Songsheng Optoelectronics' System:

• Compact Design: Highly integrated precision dispensing valve, laser module, and worktable minimize footprint.

• Coaxial CCD Vision & Monitoring: Real-time soldering alignment correction ensures precision and automated production.

• Patented Temperature Feedback: Self-tuning PID control directly regulates solder joint temperature for consistent yield.

• Non-Contact Process: Eliminates mechanical stress, enables rapid heating, and reduces thermal impact.

• Coaxial Optical Integration: Laser, CCD, temperature sensing, and guidance light share one axis, solving multi-beam alignment challenges and simplifying calibration.

• Proprietary Software: User-friendly constant-temperature laser soldering software supports customizable parameter adjustment.

• Modular Architecture: Independent optical, motion, and control modules enhance stability and maintenance efficiency.

This system integrates precision dispensing, laser soldering, temperature feedback, and control into a unified solution. Real-time temperature monitoring guarantees soldering quality and reliability, delivering robust solder joints. It is ideal for precision components such as IT devices, PCB connectors, and wire assemblies, offering exceptional performance in FPC mounting, LDS antennas, pins, and contact points.