DD207347A1 - ARRANGEMENT FOR MATERIAL TRANSMISSION BY MEANS OF LASER RADIATION - Google Patents

Abstract

The invention can be used anywhere where a highly accurate and uniform Rastermaterialabtragung to be achieved with a technical effort by targeted movement of the workpiece. The arrangement is characterized in that at least one of a rotatable polarization rotator with subsequent prism polarization group between the laser and the focusing optics is introduced with downstream workpiece.

Description

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Title of the invention ^

Arrangement for material removal by means of laser radiation

Applicability of the invention;

The invention relates to an arrangement for material removal by means of laser radiation. It can be used everywhere, where with a low technical effort by targeted movement of the workpiece a highly accurate and uniform Rastermaterialeabtragung, e.g. in the perforation of substrates for the purpose of chip separation, to be achieved. Furthermore, the invention can be used to create a dimple grid for defined surface matting or for welding thin metal parts.

Characteristic of the known technical solutions: Numerous methods and arrangements for material removal by means of laser radiation have become known, in which various partial bundles are generated by splitting a laser beam, which are focused on different locations of the workpiece to be machined.

Thus, a method for processing thin layers of electrical circuits with laser beams has become known in which a divergent bundle is generated from a parallel laser bundle and split and focused by a pacette lens arrangement into sub-beams of different directions (AS 1 765 145).

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Focussing the partially oblique light beams produces different foci with poor quality. A change in the intensity of the individual partial light bundles with each other is not possible.

It is also known to split the Laserstrahlenbiindel in two bundles on a partially reflecting mirror, which pass through each of a movable deflecting the Pokussierungsoptik in two different directions to each other and deliver two separate focal points in the cup level (AS 2 014 448). The design is very complicated and expensive, since the mirrors must be moved both translationally and rotationally. The sub-beams can receive different, non-variable intensities due to reflection differences of the mirrors.

Aim of the invention;

The invention pursues the goal of enabling a gradual material removal by means of laser radiation with a low technical outlay.

Explanation of the essence of the invention;

The invention has for its object to provide an arrangement for removal of material by means of laser radiation, which ensures a defined gradual removal of material with different partial beams with little technical effort and thereby allows a change in the intensities of the partial beams. This object is achieved in that at least one of a rotatable polarization rotator 2 with subsequent prism 3 existing polarization group * between the laser 1 and the Pokussierungsoptik 11 is inserted with downstream workpiece 12 · Here, the first rotatable polarization rotator 2 at unpolarized laser radiation from a polarizer and with polarized laser radiation from a Λ / 2 plate.

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According to the invention, it is advantageous that the prism is designed as Wollastön-Pristna.

Ausführungsbeispielt

The invention will be explained in more detail below with reference to an exemplary embodiment.

A laser 1 emits a light beam, which is split by two polarization groups 4 "consisting of a rotatable P polarization rotator 2 with subsequent prism 3 in partial beams 7, 8, 9» 10 and acts by a focusing optics 11 on the surface of a workpiece 12. If an unpolarized laser beam is emitted by the laser 1, then the first rotatable polarization rotator 2 consists of a polarization unit which linearly or partially polarizes the laser beam. When using a laser 1 with a polarized laser beam, an A / 2 plate is used for the rotatable polarization rotator 2.

The generated partial beams 5.6 are divided by the prism 3, preferably by a Wollaston prism, in two mutually perpendicular polarized partial beams. The different intensities of the partial beams are obtained by rotation of the plane of polarization by means of the polarization rotator 2. In accordance with the splitting angle of the prism 3 and the focal length of the Pokussierungsoptik 11 is obtained at a certain distance from each other on the surface of the workpiece 12, d. H. in the focal plane of the Pokussierungsoptik 11, four focal points, which cause a defined material removal at different intensity of the partial beams. In this case, the higher-energy partial beam on the material surface will produce a spot with a larger diameter.

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The e.g. The desired material removal method for dimple grid production is achieved after four steps by fourfold overlapping. For this purpose, the workpiece is shifted by precisely defined amounts. The surface profiles of the workpiece 12 thus obtained are shown on the drawing at 12a and 12b.

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Claims (3)

'"1 f * \ f Eri'indingjsansp ruGh: 1. Arrangement for material removal by means of laser radiation, in which a radiation path is arranged in the beam path of a laser and a workpiece is arranged in the focal plane of a focusing optic, characterized in that at least one of a rotatable polarization rotator (2) with subsequent prism (3) existing polarization group (4) is inserted between the laser (1) and the Pokafierungaoptik (11) with downstream workpiece (12) 2. Arrangement according to item 1, characterized in that the first rotatable polarization rotator (2) with unpolarized laser radiation consists of a polarizer and in the case of polarized laser radiation consists of an A / 2 plate. 3. Arrangement according to item 1, characterized in that the prism (3) is designed as a Wollaston prism · 3990