Solderable layer system, its use and method for manufacturing same

US4385976A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Hans Schuster-Wolden · Herrsching am Ammersee, DE
• Helmut Freller · Westerburg, DE
• Hans Kruger · Birkenfeld, DE
• Wolfgang Welsch · Heidelberg, DE
• Andre Peetermans · Poing, DE
• Hans J. Rolke · Munich, DE
• Peter Schack · Nuremberg, DE

Key dates

• Filing date: Aug 23, 1982
• Grant date: May 31, 1983
• Expiry date: Aug 23, 2002

Classification

• Technology area (CPC H): Electricity
• CPC primary: H05K2201/0326
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

In order to bring about durable solder joints on transparent thin film electrodes which themselves are not solderable, the conductive layer is treated as follows. First, the conductive layer is applied in a vacuum and, more specifically, in the fully oxidized state, and then a solderable layer is generated on the conductive layer in the same vacuum. The electrode consists preferably of an indiumtin oxide and the solder layer consists of copper. The proposed coating technique is particularly simple since the solder layer requires neither an adhesion aid nor a corrosion protection layer. If it consists of copper, it can withstand without difficulty, if it is thick enough, even small thermal stresses such as occur for instance in the fabrication of liquid crystal displays with cementing frame. The layer system is particularly well suited for the electrode leads of electro-optical displays such as liquid crystal displays.