Siemens Aktiengesellschaft

Stefan Lesjak

Hubert De Steur

Eddy Roelants

Wei Pan

Sebastien Edme

For processing electric circuit substrates, a laser source with a diode-pumped. quality-controlled, pulsed solid-state laser is used. The laser is able to emit laser radiation with a wavelength between 266 nm and 1064 nm, a pulse repetition rate between 1 kHz and 1 MHz and a pulse length of 30 ns to 200 ns with an average laser power between 1 W and around 5 W. Pre-specified operating modes can be set via a controller, depending on an area of application, with the appropriate different combinations of laser power and repetition rate. Thus, the same laser can optionally be used to perform a drilling operation, an etch removal operation or an exposure operation. Using a galvo mirror deflector unit that can also be controlled via the deflection unit, the laser beam may be deflected on the substrate in accordance with the relevant operating mode.

Arrangement and method for processing electrical substrates using lasers

In order to produce a trench structure having steep sidewalls free of residues in an, in particular, glass-fiber-reinforced substrate, the substrate is provided with a conformal mask having cutouts corresponding to the trench structure to be produced. In this case, the laser beam is guided over the cutouts of the mask in such a way that the low-energy edge regions of the laser beam are shielded and that proportion of the laser beam which impinges on the polymer surface, at each point, has an energy density above a threshold at which the substrate material including a glass fiber reinforcement that is possibly present is completely removed.

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Ettlingen, Germany

Stefan Lesjak