What is the difference between laser solder paste and regular solder paste?

The difference between laser solder paste and ordinary solder paste is mainly reflected in its composition, soldering mechanism, performance advantages and application areas, the following is a more detailed analysis:

Ingredient composition

Laser Solder Paste: Specially designed for use in the laser soldering process, the core of the paste contains highly fine, low oxidised solder powders which are able to absorb the laser energy more efficiently.In addition, the fluxes in laser solder pastes are formulated differently, designed with special solvents, active agents and other substances suitable for fast soldering, and may incorporate specific photosensitive materials or additives to enhance their responsiveness and efficiency to laser energy.These additives may also include special flux components for improved solder quality.

Common Solder Paste: consists primarily of micron-sized tin powder, flux, and possibly active agents and rosin resins.The primary function of the flux is to remove oxides, prevent re-oxidation, and provide good wetting properties for conventional reflow or wave soldering processes.Common solder pastes are formulated to focus more on stability and reliability at conventional heating rates.

Soldering Mechanisms

Laser Soldering Solder Paste: relies on the high energy density of the laser beam to heat the solder paste above the melting point in a very short period of time for fast, precise soldering.The laser soldering process is usually non-contact, reducing the impact of physical stress on the soldered area and enabling finer solder joints.

Normal Solder Paste: Soldering is achieved by heating the solder paste to a molten state at a slower rate of rise through a heat source such as a heating plate, hot air gun or soldering iron.The process may involve more physical contact and heat transfer, and soldering speed and accuracy may be limited by the performance of the heat source.The substrate, chip and solder joint need to reach a synchronised temperature, and the substrate chip requires high temperature resistance.

Performance Advantages

Laser soldering of solder paste:

High precision: precise control of the laser beam results in accurate soldering positions and small solder joint sizes.

Fast welding: High laser energy density and fast heating speed shorten the welding cycle.

Low heat-affected zone: the heat input of laser welding is small, and there is little thermal damage to the surrounding materials.

High reliability: the welded joint formed has high strength and thin and uniform intermetallic compound layer.

Common solder paste:

Cost-effective: suitable for mass production at relatively low cost.

Mature process: widely used in the manufacture of various electronic devices, mature and stable technology.

Flexibility: Adaptable to different shapes and sizes of soldered parts.

Areas of application

Laser Solder Paste: Suitable for applications requiring high soldering accuracy and reliability, such as chip packaging of high-end electronic products, soldering of micro-pitch components, precision components of aerospace and medical equipment, etc.

Ordinary solder paste: widely used in manual soldering of electronic components in consumer electronics, automotive electronics, communication equipment and other fields, as well as reflow soldering and wave soldering processes in automated production lines.

Overall, laser soldering solder paste and ordinary solder paste have their own characteristics in terms of composition, soldering mechanism, performance and application areas, and the choice of which solder paste to use depends on the specific soldering needs, process conditions and cost-effective considerations.