The laser helical drilling system consists of a beam rotator (hollow shaft motor) and optical components for laser beam displacement and tilting. The laser beam is rotated around the optical axis by the image rotator so that the laser beam is guided along a helical path relative to the workpiece surface. The image rotator (Dove prism) is mounted in a high-precision hollow shaft motor. If the laser beam is deflected or tilted relative to the optical axes, bores with different bore diameters and adjustable conicity can be produced. By using intuitive software, the target parameters of diameter and taper can be precisely set.
The use of a Dove prism provides an unrivaled process advantage in that the optical rotation of the laser beam relative to its position on the helical path achieves qualitative independence from the laser beam profile and thus a consistently round drilling result can be achieved. In addition, the optical rotation speed is twice as high as the mechanical rotation speed of the hollow shaft, which contributes to process efficiency.
1 Sec./hole
0,3 Sec./hole
0,5 Sec./hole
< 1 μm
- 5 μm
> 30 μm
negligible
5 μm
20 μm
50:1
10:1
10:1
-14°~15°
3-15°
3-8°
< 0,2 µm
2 µm
10 µm
> 0,95
~ 0.65
0,75
The quality requirements for aperture size and gap width in precision drilling and cutting have increased immensely due to the technological trend towards miniaturization.
In this context, high-precision helical drilling optics (HDO) was invented, which, in combination with ultra-short laser beams, offers the best processing technology for metallic and non-metallic materials. In addition, HDO offers the flexibility and process stability of defined drilling diameters and conicity for micro-drilling and kerfing.
Since its first introduction to the global market in 2008, helical drilling technology has undergone several optical and system developments to make it suitable for current and future higher processing requirements.
Today's seventh generation HDO v7 can be used in three different wavelength ranges: UV, green and IR. In addition, the HDO v7 successfully uses a modular design where the rotating core module and the observation module are separated for processing and the interface has been standardized to allow full integration into various processing systems.
The HDO v7 is emerging as a key device for a variety of applications for micro-holes in high-value products such as turbine blades and functional surfaces.
> 30:1
> 0.94
< ± 2 µm
± 15°
With helical drilling technology, holes with a diameter of 10 µm can be produced in material thicknesses of 100 µm. The maximum achievable aspect ratio depends on the material thickness.
Examples
Material thickness: 0.1 mm - aspect ratio: 10:1
Material thickness: 1 mm - aspect ratio: 30:1
Material thickness: 3 mm - aspect ratio: 50:1
Positive and negative tapers with maximum wall angles of +/-15° can be achieved. Cylindrical holes with high aspect ratios are also possible in all materials.
In combination with an ultra-short pulsed laser beam source, even sensitive materials can be processed regardless of the material.
Laser helical drilling is limited to the production of round holes. With the addition of a precise planar axis system, contour cuts can be made and thus complex structures such as rectangular profiles or gear profiles with adjustable cutting walls can be produced.
For the best possible drilling quality, we recommend using an ultra-short pulsed laser beam source with pulse durations of less than 15 ps. In terms of wavelength, IR (1010-1070 nm) laser beam sources as well as VIS (510-540 nm) or UV (340-360 nm) can be used.
The HDO consists of the rotation module and the focusing module. The rotation module can be fixed statically and placed horizontally in the machine, while the focusing module (weight approx. 4 kg) can be mounted on a braked Z-axis to set the focus for various components.