Siemens Aktiengesellschaft

Ernst Andrascek

Hans Hadersbeck

Alfred Groeber

Friedhelm Wallenhorst

The present invention provides an improved electroplating apparatus having an electroplating cell equipped with an anode, cathode and diaphragm ring. The electroplating cell is suspended in an electrolytic bath. The cell is composed of a plastic tube whose lower opening is covered by an anode surface and whose upper opening is covered by a wafer holder for holding the semiconductor wafer. The electroplating apparatus further includes an activated carbon filtering aimed at the levelling effect.

Electroplating apparatus for producing humps on chip components

A method for producing a copper platform on integrated circuits formed on a semiconductor wafer wherein an aluminum layer is back-sputtered over the circuits to provide contact surfaces thereon, followed by sputtering on successive layers of titanium and copper on the aluminum layer. A copper platform is electrolytically built up above the aluminum layer and thereafter the copper layer is etched away. The copper platform is then metallized by electroless deposition, and finally the titanium layer is etched away.

Method of producing copper platforms for integrated circuits

A chemical gilding bath is formulated on the basis of an alkaline, aqueous solution of an alkali gold cyanide complex and has a reducing agent and a stabilizing agent therein. The reducing agent is an organic compound containing at least one enol group within the molecular structure thereof, such as ascorbic acid or salts thereof. The pH value of the bath is adjusted by a buffer solution so as to range between about 7.5 to 12 and preferably is about 8.

Chemical gilding bath

A flexible printed circuit board has conductors on opposite sides thereof which are through-contacted by die-punching the board to form an angularly-displaced tongue portion about which solder is flowed to contact both conductors. A terminal pin is optionally inserted through the board to connect a component, the pin being engaged by the angularly-displaced tongue to ensure reliable mechanical and electrical contact in the soldered joint. The through-contact is formed with a bevel-faced die in conjunction with a cutting plate.

Flexible through-contacted printed circuits

A process is provided for improving the solderability of electric circuit boards with conductor paths composed of copper or copper alloys, in which, at least at the locations to be soldered, the conductor paths are cleansed in a first solution and are thereby deoxidized, and are then activated in a second solution.

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Munich, Germany

Ernst Andrascek