The structure and operation of a galvo scanner
A galvo scanner is based on what are known as galvanometers. These are fast-responding, rotatable electric motors with integrated position control. Small mirrors are mounted on their rotors, which precisely deflect the laser beam.
Control is via an analogue signal, typically in the range of ±10 V. This signal specifies the desired mirror position. At the same time, an integrated sensor – usually an optical or capacitive rotary encoder – continuously measures the actual position.
The system operates on a closed-loop control principle:
- The target position is specified
- The actual position is being measured
- Deviations are corrected in real time
This enables the mirror to be positioned extremely quickly and with a high degree of precision, which is crucial for reproducible processes.
2D galvo scanner with X- and Y-axis control
In practice, 2D galvo scanners are frequently used. In this case, two mirrors are used to deflect the laser beam:
- A mirror controls the movement along the X-axis
- a second mirror deflects the beam along the Y-axis
The mirrors move only within a small angular range, typically up to ±20°. Despite this small angle, the laser beam is significantly deflected on the machining surface.
To ensure a constant focus position across the entire processing field, a so-called F-theta lens is often used. This ensures that the laser beam remains precisely focused on a flat surface, regardless of the deflection angle.
Why are galvo scanners crucial for laser brazing processes?
In electronics manufacturing, the Galvo scanner is specifically used to direct laser energy precisely and quickly onto the solder joint. This makes it possible to make processes significantly more efficient and reproducible.
EUTECT uses this technology in particular in laser brazing processes, where the laser serves as the heat source. Applications such as the so-called ‘laser knife’ also benefit from the precise beam guidance.
The advantages at a glance:
- high-precision positioning of the laser beam
- Fast cycle times thanks to dynamic deflection
- reproducible energy input
- Optimised solder joint quality in complex assemblies
In some cases, the use of a galvo scanner even makes it possible to dispense with additional mechanical movements or conventional soldering processes.
Find out more about our cycle time-optimised Laser Knife technology here:
Practical applications
Thanks to the contactless and highly dynamic control of the laser beam, even demanding soldering tasks can be carried out reliably. Controlled energy input is a decisive advantage, particularly when working with sensitive or complex assemblies.
The combination of rapid control, precise positioning and constant focusing ensures that processes run smoothly whilst meeting high quality standards.
Precision as the key to process optimisation
A galvo scanner is a key component of modern laser systems. By precisely controlling the laser beam, it enables efficient, accurate and repeatable processes in electronics manufacturing.
At EUTECT, we make targeted use of this technology to optimise laser brazing processes and achieve the highest quality standards.
