METHOD AND DEVICE FOR PROVIDING THROUGH-OPENINGS IN A SUBSTRATE AND A SUBSTRATE PRODUCED IN SAID MANNER

摘要

The invention relates to a method and device for creating, by means of a laser beam, a plurality of recesses (5) in a substrate (2) which can be used as an interposer, and to a substrate (2) produced in said manner. According to the invention, a laser beam (3) is directed to the surface of a substrate (2). The duration of the effect of the laser beam (3) is extremely short such that the substrate (2) is only modified concentrically about the laser beam axis (Z) without it reaching a recess of the substrate material. Said laser beam (3) is initially diverted by a transmission medium (8) having a higher intensity-dependent refractive index than air, and subsequently reaching the substrate (2). As the intensity of the used pulsed laser is not constant but increases to a maximum over the temporal course of the single pulse, and then reduces, the refractive index also changes. The focus point (9a) of the laser beam (3) moves between the outer surfaces (11, 12) of the substrate (2) along the beam axis (Z) such that it reaches the desired modification along the beam axis (Z) without correcting the laser processing head (10) in the z-axis.