International Business Machines Corporation

Hans J Trumpp

Johann Greschner

Friedrich W Schwerdt

Harald Bohlen

Peter Nehmiz

Helmut Engelke

Reinhold Muhl

A method of improving the adhesion between a synthetic substrate and metallized layers deposited thereon. A glass resin layer is spin-coated onto an epoxide substrate. The glass layer is covered by a photoresist layer which is roughened by reactive ion etching. The roughened contour of the photoresist layer is transferred via reactive ion etching to form a perforation pattern in the glass layer. The substrate is then etched vertically and horizontally to produce recesses in the substrate having overhanging walls. A thin copper layer is sputtered onto the substrate and copper conductors are sputtered onto the thin copper layer, the copper layers filling the recesses. The recesses and overhangs form mortices in the substrate, and the copper layers within the recess form tenons which fittingly engage with the mortices to produce adhesion between the substrate and the metallized layers in the order of 1000 n/m.

Synthetic substrate with adhesive metal layer

Method of making adhesive metal layers on substrates of synthetic

A process for producing printed circuit boards having metallic conductor structures embedded in the insulating substrate and whose front and back sides are conductively connected by means of plated through holes. The first steps of the process comprise producing a matrix on an epoxy resin substrate consisting of a lift-off layer, an aluminum barrier layer and a positive photoresist layer. A negative image of the desired conductor pattern is then generated in the photoresist layer using conventional photolithographic techniques. The negative image is etched into the barrier layer and the lift-off layer such that an undercut occurs under the barrier layer. Subsequently, vertical trenches are etched into the epoxy resin substrate. After drilling of the through holes, an activating layer of copper is deposited by means of magnetic field enhanced cathode sputtering on the surfaces of the trenches, the through holes and the barrier layer. The lift-off layer, together with the barrier layer covering it, is removed by immersion in a suitable solvent, and copper conductors are subsequently grown in the etched conductor trenches.

Process for producing printed circuit boards with metallic conductor

For mutually aligning (registering) mask and substrate in X- or corpuscular ray lithography, an electron beam (16) is used which extends collaterally to the exposure beam (ion beam or X-ray) and which is suppressed during the actual exposure process. For coupling the electron beam to the exposure beam path, a magnetic field (7) is used. The accurate relative position of mask and substrate is determined during alignment by tilting the electron beam. Fine alignment during exposure is effected by suitably tilting the ion beam or shifting the substrate relative to the X-ray. The mask (10) used for exposure consists of a very thin silicon layer with a pattern area (M) and a registration area (R) spatially separated therefrom. The registration area consists of a plurality of openings, the pattern area of blind holes.

Mask and system for mutually aligning objects in ray exposure systems

Growing community of inventors

Stuttgart, Germany

Hans J Trumpp