What Factors Affect the Working Efficiency of Laser Soldering?

What Factors Affect the Working Efficiency of Laser Soldering?

Laser soldering offers excellent welding quality and high efficiency, making it highly popular among many manufacturers. So, what factors influence the efficiency of laser soldering? Let’s explore this together with Songsheng Optoelectronics.

                                                                                        Laser soldering technology offers broad applicability

Equipment Factors

Laser Power:
Power directly determines the heating rate and peak temperature during soldering. Insufficient power may prevent the solder from fully melting, leading to defects like cold joints and requiring rework, which reduces efficiency. Conversely, excessive power can cause solder splashing, overheating, or even damage to components, negatively affecting both quality and efficiency. For example, when soldering tiny electronic component leads, the power is typically set between a few watts and several tens of watts to avoid thermal damage.

Laser Wavelength:
Different materials exhibit varying absorption and reflection properties for different laser wavelengths. Selecting the appropriate wavelength enhances soldering efficiency and quality. For instance, certain solder alloys absorb specific wavelengths more effectively, allowing faster and more efficient melting.

Beam Spot Size:

The spot size influences energy density distribution. A smaller spot provides higher energy density, enabling finer soldering but requiring higher alignment precision and reducing efficiency due to limited coverage. A larger spot offers lower energy density, suitable for broader solder melting, but may cause unwanted heat effects on surrounding areas. If the spot is too large, precision for micro-soldering decreases, potentially requiring multiple adjustments and lowering efficiency.

Soldering Speed:
Speed is closely tied to soldering time. Excessive speed shortens laser exposure, leading to incomplete melting and rework, while overly slow speeds risk overheating and reduced productivity.

Equipment Stability:
Stable operation is critical for efficiency. Malfunctions or parameter fluctuations during soldering can result in inconsistent quality, necessitating downtime for maintenance or recalibration, thereby reducing overall productivity.

                                                                          Automotive components can be processed using laser soldering technology

Material Factors

Material Properties:
Different materials exhibit varying thermal conductivity and melting points, requiring adjusted soldering parameters. Improper material selection or mismatched parameters will compromise soldering quality and efficiency. For example, materials with high thermal conductivity require higher laser power or extended soldering duration to ensure complete solder melting.

Surface Condition:
Surface cleanliness and oxidation levels significantly impact soldering results. Contaminants 

like oil residues or oxides may cause defects (e.g., cold joints, poor adhesion), necessitating additional cleaning steps that reduce efficiency.

Process Parameter Settings

Soldering Duration:
The welding time directly affects outcomes. Duration must be calibrated based on material properties and joint requirements for each phase.

Solder Feed Volume:
Excessive solder may form balled joints, obscuring pin legs and requiring rework. Insufficient feed leads to weak connections, demanding reprocessing. For instance, automated laser soldering requires precise feed control tailored to joint size and geometry.

Preheating Temperature:
Preheating enhances efficiency and quality. Overheating oxidizes pads, causing poor solder wetting; insufficient preheating prolongs the time needed to reach optimal soldering temperature.

                                                                                 Benchtop Constant-Temperature Laser Soldering System

Environmental Factors

The working environment for laser soldering should remain stable to avoid the impact of temperature, humidity, and other environmental factors on the equipment. For example, in high-temperature environments, heat dissipation may be affected, leading to reduced laser power or equipment failure. In humid conditions, moisture may damage the equipment, affecting its performance and lifespan.

The use of inert gas (such as argon) for protection during soldering can prevent oxidation and spatter, thereby improving soldering quality. Improper gas shielding may result in oxidized solder joints, uneven surfaces, and other defects, requiring rework and reducing efficiency.

Operational Factors

The skill level of operators significantly influences soldering results. Proficiency in equipment operation and parameter adjustment is crucial for ensuring quality. Operators must undergo professional training to familiarize themselves with operational procedures and parameter settings to enhance efficiency.

Following standardized procedures is essential for maintaining soldering quality. For instance, pre-soldering cleaning and preparation, maintaining stable equipment and consistent parameters during soldering, and post-soldering inspection and testing are critical steps. Non-compliance with procedures may lead to quality issues, necessitating rework and reducing productivity.

Songsheng Optoelectronics Constant-Temperature Laser Soldering System

The system provides continuous 976nm infrared laser output. It consists of a CCD coaxial alignment system and a semiconductor laser, capable of importing various file formats to achieve precise soldering. With real-time temperature feedback and CCD coaxial alignment, the system ensures constant-temperature soldering and accurate positioning of precision components, guaranteeing high yield rates in mass production.

This product is suitable for PCB spot soldering, metal and non-metal material welding, sintering, heating, and more. It features high-precision, real-time temperature control, making it particularly ideal for highly sensitive, precision soldering applications. (We offer free sample testing for soldering evaluation.)

                                                                                     Structural Diagram of Constant-Temperature Laser Soldering System

Features of Constant-Temperature Laser Soldering System

1. High Precision Processing

o    Minimum laser spot diameter of 0.1mm enables soldering of micro-spaced mounted components and chip parts.

2. Localized Heating with Minimal Thermal Impact

o    Short-duration localized heating reduces thermal effects on the substrate and surrounding components.

o    Customizable heating profiles ensure consistent soldering quality for different lead types.

3. No Tip Wear, High Efficiency

o    Eliminates consumable soldering tips and heater replacements, enabling continuous high-efficiency operation.

4. Micron-Level Precision

o    Laser spot accuracy at micron scale with programmable time/power control, far surpassing traditional soldering irons.

o    Capable of soldering in spaces under 1mm.

5. Coaxial Multi-Optical Path & CCD Alignment

o    "What You See Is What You Get" visual positioning eliminates repeated calibration.

6. Non-Contact Process

o    No mechanical stress or electrostatic discharge (ESD) risks associated with contact soldering.

7. Green & Maintenance-Free

o    Laser as clean energy source requires no consumables, with simple maintenance and user-friendly operation.

8. Crack-Free Lead-Free Soldering

o    Ensures reliable lead-free joints without solder cracks.