Siemens Aktiengesellschaft

Siemens S.a.

Hubert De Steur

Marcel Heerman

Eddy Roelants

Jacky Vanhumbeeck

Guido Heyneman

Wolfgang Pernegger

Jozef Van Puymbroeck

Hans Juergen Mayer

Egon Bussmann

Chris Vandenbossche

Wei Pan

Johannes Helder

Luc Boone

Laurent Danneels

Johan Helder

Marc De Vogelaere

Lothar M&uuml;ller

Andre Kletti

Marcel Heermann

Alexander Kilthau

Stefan Lesjak

Martin Wehner

Petra Mitzinneck

Friedbert Roth

Mark Van Biesen

Mladen Polgar

Oliver Thuerk

S&eacute;bastian Edm&eacute;

Bruno Flamme

Otto M&auml;rten

Marc Van Biesen

Christian Overmann

For the laser drilling of organic materials, in particular for making blind holes in dielectric layers, a frequency-doubled Nd-vanadate laser with the following parameters is used: 

Method and device for laser drilling organic materials

A method and an apparatus are for rapidly processing dielectric substrates using laser beams. A pulsed laser beam having a pulse repetition frequency greater than approximately 50 kHz and having pulse lengths shorter than approximately 200 ns is used for this purpose. Given a suitable choice of the parameters which characterize the processing laser beam, it is possible to ensure both a high throughput of bored holes and a high hole quality. With the use of a Q-switched CO laser, a wavelength of approximately 9.2 &mgr;m and a pulse energy of approximately 0.7 mJ are used. As a result, by way of example, 500 holes per second can be bored into an LCP substrate having a thickness of 0.4 mm. The high throughput and the simultaneously high hole quality are a consequence of the wavelength chosen, the short pulse lengths, the high repetition rate and the pulse energy that is likewise high compared with conventional laser processing apparatuses in the area of electronic fabrication.

Method and apparatus for laser processing

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.

Method for producing a trench structure in a polymer substrate

A method and device can be used to pattern both regions of a printed circuit board which are provided for coarse conductor structures and regions which are provided for relatively fine conductor structures of the printed circuit board. In each case, this can be done via laser processing. Both regions are firstly coated with a continuous metallization layer and covered with an etch resistor. The coarse conductor structures are predefined with a laser beam with a relatively long wavelength by exposing the metal surfaces which are not required. In addition, the fine conductor structures are also pre-shaped by processing the etch resist with a laser beam with a relatively short wavelength. Then, in a common etching process, all the exposed surface regions of the metal layer are etched away so that only the coarse and fine conductor track structures which are covered by the remaining etch resist are left. As a result of the removal of the rest of the etch resist, the surfaces of the conductor tracks which are produced are then exposed.

Method and apparatus for structuring printed circuit boards

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 method and device for the laser drilling of laminates includes the use of a frequency-doubled Nd vanadate laser. The laser includes the following parameters: pulse width<40 ns, pulse frequency&gE;30 kHz for the metal layer and &gE;20 kHz for the dielectric layer, and wavelength&equals;532 nmn. Such a laser is used for the laser drilling of laminates which have at least one metal layer and at least one dielectric layer including an organic material.

Method and device for laser drilling laminates

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

The invention relates to a method for describing a predetermined desired course ( ) with a beam of particles or waves, wherein a movable beam-directing device influences the direction of the beam, so that the latter describes an actual course ( ). The deviation of the actual course ( ) from the desired course due to inertia is minimized by specifying a corrected desired course ( ), which describes diversions at the point of direction changes. The invention also relates to the use of this method for laser structuring or for writing guard plates or dial plates.

Method for describing a predetermined desired course with a beam consisting of particles or waves and use of this method

A method and arrangement for calibrating a laser processing machine for processing workpieces. The present invention ensures a fast and reproducible method and arrangement for calibrating a laser processing machine by measuring a position of a predetermined test pattern on a test plate while taking into account any imaging errors caused by the deflection unit.

Method and device for calibrating a workpiece laser-processing machine

To drill micro-holes in a multi-layer substrate having a first metal layer and at least one second metal layer, and having a dielectric layer arranged between two metal layers, use is made of a solid-state laser. The beam of the laser, in a first operation, ablates the first metal layer and, in a second operation, ablates the dielectric layer down to the second metal layer. In the first operation, the laser beam is set to a repetition frequency of at least 15 kHz, focused onto the first metal layer and moved in a circle corresponding to the diameter of the desired hole, in such a number of passes until this metal layer is cut through. Then, in the second operation, the laser beam is set to a preferably lower repetition frequency, directed out of focus onto the dielectric layer exposed in the hole and moved, with a circumferential velocity which is higher compared with the first operation, in one or more concentric circles, until the dielectric layer is ablated in the hole region. The effective energy density in the second operation is selected, by setting the defocusing and the circumferential velocity, in such a way that the effective energy density lies below the threshold for ablation of the second metal layer.

Method for drilling micro-holes with a laser beam

For the laser machining of organic materials, a laser with the below listed parameters is used. The laser has a wavelength of 300 nm to 1200 nm, a pulse width of <50 ns and a pulse frequency of >20 kHz. To increase a degree of absorption and consequently the machining rate, additives with good absorption of the laser beam with the respectively chosen wavelength are admixed with the organic materials.

Method for the laser machining of organic materials

The invention relates to a method for producing interconnections with electrically conductive cross connections between the top and the bottom part of a substrate and interconnections having such cross connections. The substrate (S ) is given a slanted, roof-shaped or convex contour (K ) in the area of at least one front face and/or in the area of at least one inner wall of a recess. After metallizing the substrate (S ), printed-board conductor-shaped cross connections (Q) are produced in the area of the above-mentioned contours (K ) simultaneously with laser structuring of printed board conductors (L) on the top part (0) and the bottom part (U) of the substrate (S ).

Wiring arrangements having electrically conductive cross connections and method for producing same

In order to form metallic conductor patterns having connection regions that can be soldered and/or bonded on electrically insulating substrates, firstly a metalization is applied to the substrate and is then removed again, at least in those regions adjoining the desired conductor pattern. There then follows the electrolytic deposition of a final surface which can be soldered and/or bonded to the connection regions. Clean-room conditions are not necessary.

Method for forming metal conductor patterns on electrically insulating substrates and supports

An analysis system for determining total copper content in waste-water, as from a galvanizing system, comprises periodically taking samples from such waste-water, acidifying such samples with a metalliferous acid containing a metal which forms a strong cyanogen complex and which exhibits a larger electro-negative potential than copper, such as Pd, reducing cupric ions to cuprous ions, adjusting the pH of the resulting sample solution, adding a copper color-forming reagent, such as bathocuprione disulfonic acid salt, and determining the color content by colorimetry. In order to determine a reagent value, a prepared waste-water sample can be subjected to colorimetry before and after addition of the color-forming reagent.

Analysis system for determining copper content in waste water

A circuit arrangement is disclosed for determining the end point in an amperometric titration, in which the current between a working electrode and a counter electrode is measured as a function of the total volume of the titration agent added in volume units. The working electrode is operated with a constant polarization voltage with respect to a reference electrode and a closed-loop control is provided for holding the polarization voltage prescribed between the working electrode and the reference electrode at a constant. The prescribed rated value voltage is compared to the actual value voltage identified between the working electrode and the reference electrodes. The reference value voltage is prescribed with the assistance of a reference value generator, the actual value voltage is identified in a high resistance manner with the assistance of an impedance transformer and the reference value/actual value deviation is compensated by way of a summing integrator.

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Drongen, Belgium

Hubert De Steur