Abstract: Disclosed is a valve having a housing with a valve seat for a two-piece flap which is rotatably mounted on a drive shaft. An annular piston seal and an adjacent cover disk are disposed between the first part and the second part of the two-piece flap so as to revolve therearound. The diameter of the cover disk is smaller than the diameter of the annular piston seal which is embodied as a metal ring that is provided with a gap. The invention also relates to the use of the valve as a gas recirculation valve.

Abstract: To drill holes in an electric circuit substrate with the help of a laser beam, the drilling being performed by a circular motion of the laser beam within the area of the intended drill hole, the movement of the laser beam is created via two in-line deflection units. The first deflection unit, which preferably contains galvomirrors, triggers the jump of the laser beam from a drill position to the respective next drill position and the centering within the respective drill position. The second deflection unit, which preferable contains piezoelements, modulates a continuous circular motion onto the laser beam. In doing so the laser is only turned on if the first deflection unit is at a standstill.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: When a laser beam is focussed onto a substrate for the purpose of substrate processing, the optical units such as beam expander, deflecting unit, and optical imaging device prescribe the range of depth of focus in which it is possible to work with a minimum spot size. The difficulty of boring thin holes, especially in thick substrates, is overcome with a second laser beam that is widened via a second beam expander and likewise focused onto the substrate via the deflecting unit and the optical imaging device. The position and the length of the second range of depth of focus can be varied by selecting the magnification of the second beam expander or by maladjustment. Thin holes can also be bored into thick substrates by using the two laser beams one after another.