Siemens Aktiengesellschaft

Hans Juergen Mayer

Eddy Roelants

Hubert De Steur

Alexander Kilthau

Andre Kletti

Wei Pan

Marc Van Biesen

Otto M&auml;rten

Christian Overmann

Petra Mitzinneck

Martin Wehner

Werner Nieschler

Oliver Thuerk

When holes are being drilled in an electric circuit substrate, a laser beam is moved on concentric circular tracks in the region of the hole to be drilled. The transition from one circular track to the next takes place in each case on an arc that departs approximately tangentially from the circular track last traversed and nestles approximately tangentially against the circular track newly to be described in such a way that in each case the starting point of a new circular track is offset by a prescribed angle from the starting point of the preceding circular track.

Method for drilling holes in a substrate

A laser machining device can be used to direct two independent laser beams onto the same machining field in a single machining process. This can be achieved by using an at least partially reflective optical element, configured such that the first laser beam is essentially transmitted and the second laser beam is essentially reflected. The beam paths of the two laser beams are varied independently of each other by two deflection units before they strike the at least partially reflective optical element. This results in a large number of advantageous possibilities for the precise and continuous machining of materials.

Laser machining device

To calibrate the optical system of a laser machine having a laser source, a deflecting unit and an imaging unit, firstly a first sample plate is arranged in the focal plane of the imaging unit, with prescribed grid points being marked by the laser beam. After that, the marked points are measured by means of a camera, and their position values are compared with the prescribed position values of the target points, in order to derive first correction values from this and store them. After that, a second sample plate is arranged in a second calibrating plane, at a distance from the focal plane, and is targeted by the laser beam and provided with markings. The second sample plate is measured by the camera, and the measured positions of the markings are compared with the positions of the target points, in order to derive second correction values and store them. From the stored first and second correction values of the two planes, correction values can then be determined by interpolation for arbitrary target points in the spatial region between the focal plane and the second calibrating plane and be used for the activation of the deflecting unit.

Method of calibrating the optical system of a laser machine for processing electrical circuit substrates

In a method for the laser drilling of holes in a circuit substrate with the aid of a perforated mask, a laser beam is moved in the region of the perforated mask on a circular path. The center point of the region lies concentrically with respect to the set position of the respective hole in the mask. Further, the diameter of the region is smaller than the diameter of the hole. At the same time, the diameter of the laser beam spot is chosen to be large enough that it always covers the center point of the perforated mask during the circular motion. As a result, an energy distribution of the laser energy, which is as uniform as possible, is achieved in the region of the perforated mask.

Method of laser drilling

A steam generator has a preheater for preheating feed-water supplied from an external source, the preheater receiving its heat from the steam generator's heat exchanger. If the supply of feed-water to the steam generator is reduced while the heat exchanger maintains its heat output, the feed-water is overheated. To prevent this, some of the already heated feed-water in the steam generator is fed to the feed-water entering the preheater, this raising the feed-water's temperature relative to the temperature of the heat exchanger, reducing the rate of exchange of the heat from the heat exchanger to feed-water in the preheater, and by this control preventing overheating of the water in the preheater.

Growing community of inventors

Viernheim, Germany

Hans Juergen Mayer