Schering Aktiengesellschaft

Rolf Rolff

Detlev Nitsche

Kurt Heymann

A method for measuring the density of a current during an electroplating process in an electroplating bath, wherein a voltage is measured by a voltmeter, positioned outside the bath, immediately between the outer surface of the item to be electroplated and the outer surface of an isolated metallic island.

Method of measuring current density in electroplating baths

A reference branch circuit includes a voltage divider. Each of at least one regulated branch circuits includes the collector-emitter circuit of a regulating transistor and a measuring resistance. Each regulated branch circuit is associated with a comparator, which compares voltage across the measuring resistance of the corresponding regulated branch circuit to a reference voltage appearing at a reference tap of the voltage divider in the reference branch circuit. Current passing through each regulated branch circuit is regulated to be equal to the current flowing through the reference branch circuit.

System for equalizing current flow in a plurality of branch circuits

A catalytic lacquer for the production of printed circuit boards using basic materials and metal deposition methods. The lacquer has the following composition: a binding agent based on synthetic or natural materials; water; a metal salt; a complex former; and a reducing agent. The binding agent may be a water soluble or dispersable compound. The metal salt may be a water soluble palladium, copper, silver, gold or nickel salt, preferably the sulphate. The complex former may be in the form of a compound forming stable complexes with metal ions. The reducing agent may be in the form of formaldehyde, hydrazine or its derivatives, boron compounds, sorbitols, phosphites, or hydrophosphites. The lacquer may also include an organic solvent or solvent mixture, preferably methylene chloride. A filler and stabilizer may also be included in the composition of the lacquer. The lacquer may be applied to base materials by means of silk screen printing, and then dried so that the metal seed layer is strengthened by the action of a metal deposition reduction bath.

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Berlin, Germany

Rolf Rolff