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Laser soldering

Main advantage of laser soldering technique is flexibility under precise control.

All process parameters like energy intake, spot size and control parameters are individually matched to every soldering joint, thus achieving supreme connections even under challenging conditions.

Laser soldering is often applied as selective laser soldering, to solder parts that are heat-sensitive, small or hard to access with conventional joining techniques ( reflow or wave soldering ).

With more than 15 years of experience in laser technology we support your soldering application, feel free to contact us for a profound consulting on your process.

The use of a high-brightness diode laser and laser process controller LASCON enables you to control the soldering process by whats important – the right temperature at the right time

non-contact solderingadjustable spot size, minimum 100 micrometer
local, precise energy intakeexact temperature control
on-line quality control100% repeatability, traceability
easy automationvery low maintainance

Selective laser soldering is used in electronics industry to solder smd and through-hole components ( tht ) to printed circuit boards ( pcb ), as well as solar cells in pholtovoltaics industry.

The diagram below shows a soldering process, monitored and controlled by laser process controller LASCON.

The green curve in the diagram shows the target process temperature ( setpoint ). The red curve represents the actual temperature in the joint, measured by the integrated high-speed pyrometer. The black curve shows the laser power in percent, used to adjust the actual temperature to the target temperature.

The Controller Speed is up to 10 kHz, making real-time control possible. As you can clearly see the soldering temperature in the spot matches the target temperature during the three phases of the soldering process ( preheating, solder wire feeding, joint wetting ).

Initially, the pad is preheated to a temperature of 300°C.
After 1 second, LASCON® switches on the solder wire feeder. The solder wire feeder is switched off after approx 1.4 s. The Soldering temperature is controlled throughout the process and kept at the optimum preselected level. Laser power output varies, controlled by the laser process controller LASCON to attain the right process temperature.

The soldering process can be monitored on-line and controlled via preset process quality parameters, allowing an automatic pass/fail quality decision to be made.

As an alternative to welding with tin solder wire, laser soldering with soldering paste is also possible. The paste must be applied with a dispenser. Squirting is largely prevented due to an optimized temperature program.

Various points can be warmed up simultaneously or in succession using scanners

Press release ( in german ) for selective laser soldering in Productronic Magazine