Device and method for material processing by means of laser radiation

A device for material processing by means of laser radiation, said device comprising a source of laser radiation emitting pulsed laser radiation for interaction with the material;

• optics focusing the pulsed processing laser radiation to a center of interaction in the material;
• a scanning unit shifting the positions of the center of interaction within the material, wherein each processing laser pulse interacts with the material in a zone surrounding the center of interaction assigned to said laser pulse so that material is separated in the zones of interaction;
• and a control unit which controls the scanning unit and the source of laser radiation such that a cut surface is produced in the material by sequential arrangement of zones of interaction, wherein the control unit controls the source of laser radiation and the scanning unit such that adjacent centers of interaction are located at a spatial distance a ≦10 μm from each other.

A device for material processing by means of laser radiation, said device comprising a source of laser radiation emitting pulsed laser radiation for interaction with the material;

• optics focusing the pulsed processing laser radiation to a center of interaction in the material along an optical axis;
• a scanning unit shifting the positions of the center of interaction within the material, wherein each processing laser pulse interacts with the material in a zone surrounding the center of interaction assigned to said laser pulse so that material is separated in the zones of interaction;
• and a control unit which controls the scanning unit and the source of laser radiation such that a cut surface is produced in the material by sequential arrangement of zones of interaction, wherein the control unit controls the source of laser radiation and the scanning unit such that the cut surface comprises two portions located adjacent to each other along the optical axis and irradiates these at least partially with processing laser radiation pulses applied within a time interval t≦5 s.

A method of material processing by means of laser radiation, wherein pulsed laser radiation is generated, is focused on centers of interaction for interaction in the material, and the position of the centers of interaction in the material is shifted, each processing laser pulse interacting with the material in a zone surrounding the center of interaction assigned to said laser pulse, so that material is separated in the zones of interaction and a cut surface is formed in the material by a plurality of zones of interaction, wherein merely a perforation of the material is generated in the cut surface, whereby not all of the zones of interaction located within the cut surface adjoin or overlap each other and, thus, material bridges in which the material remains connected remain between regions in which the material is being separated,

• wherein the cut surface comprises an additional surface portion, the additional surface portion being produced at a processing laser pulse fluence F>3 J/cm2, and wherein the additional surface portion surrounds the cut surface.

A method of material processing by means of laser radiation, wherein pulsed laser radiation is generated, is focused on centers of interaction for interaction in the material, and the position of the centers of interaction in the material is shifted, each processing laser pulse interacting with the material in a zone surrounding the center of interaction assigned to said laser pulse, so that material is separated in the zones of interaction and a cut surface is formed in the material by a plurality of zones of interaction, wherein merely a perforation of the material is generated in the cut surface, whereby not all of the zones of interaction located within the cut surface adjoin or overlap each other and, thus, material bridges in which the material remains connected remain between regions in which the material is being separated,

• wherein the cut surface is composed of at least a first and a second partial cut surface, the cut surface and the additional surface portion being provided with different numbers and/or strengths of material bridges.

A method of material processing by means of laser radiation, wherein pulsed laser radiation is generated and focused to centers of interaction in the material and the positions of the centers of interaction in the material are shifted, each processing laser pulse interacting with the material in a zone surrounding the center of interaction assigned to said laser pulse, so that material is separated in the zones of interaction, and a cut surface is produced in the material by sequential arrangement of zones of interaction, wherein adjacent zones of interaction are located at a spatial distance a ≦10 μm.

A method of material processing by means of laser radiation, wherein pulsed laser radiation is generated, focused to centers of interaction in the material and the positions of the centers of interaction in the material are shifted, each processing laser pulse interacting with the material in a zone surrounding the center of interaction assigned to said laser pulse, so that material is separated in the zones of interaction, and a cut surface is produced in the material by sequential arrangement of zones of interaction, wherein the zones of interaction are illuminated with pulses each having a fluence F of less than 5 J/cm2;

• wherein the cut surface comprises an additional set surface portion, the additional surface portion being produced at a processing laser pulse fluence F>3 J/cm2.

A method of material processing by means of laser radiation, wherein pulsed laser radiation is generated, focused to centers of interaction in the material and the positions of the centers of interaction in the material are shifted, each processing laser pulse interacting with the material in a zone surrounding the center of interaction assigned to said laser pulse, so that material is separated in the zones of interaction, and a cut surface is produced in the material by sequential arrangement of zones of interaction, wherein the zones of interaction are illuminated with pulses each having a fluence F of less than 5 J/cm2;

• wherein the fluence of each processing laser pulse is above a threshold value M given as
• M=3.3 J/cm2−(2.4 J/cm2)/(1+(a/r2)2)
• wherein a is the spatial spacing of the centers of interaction and r is a parameter, with 3 μm≦r≦10 μm.

A method of material processing by means of laser radiation, wherein pulsed laser radiation is generated, is focused on centers of interaction for interaction in the material, and the position of the centers of interaction in the material is shifted, each processing laser pulse interacting with the material in a zone surrounding the center of interaction assigned to said laser pulse, so that material is separated in the zones of interaction and a cut surface is formed in the material by a plurality of zones of interaction, wherein merely a perforation of the material is generated in the cut surface, whereby not all of the zones of interaction located within the cut surface adjoin or overlap each other and, thus, material bridges in which the material remains connected remain between regions in which the material is being separated;

• wherein the cut surface comprises an additional cut surface portion, the additional surface portion being produced at a processing laser pulse fluence F>3 J/cm2.