High performance gold free electrical contacts for hearing aids

Present day low power electrical contacts systems are based on the heavy use of costly gold coatings. The multi-layered contact systems are typically made on a substrate with a layer of Nickel followed by a layer of Gold with thickness depending on the application and exposure conditions. Main issues with the reliability of electrical contacts are the corrosion and wear, which limits the freedom to reduce the gold layer thickness. The goal of the HIPEC project is to develop electrical contact systems without the use of gold, while providing good corrosion and tribological performance.

The focus of the project is to understand the corrosion reliability issues of the present day gold coated contacts in detail, including the involved failure mechanisms. Investigation will address problems with materials combinations including substrate material and coating as well as the loss of electrical contact due to fretting corrosion. A special focus will be on the contacts used for hearing aids applications.  
Further, HIPEC project will focus on developing new contact systems without the use of Gold, while using an under layer of materials that passivate easily followed by a hard, wear resistant layer of conducting coating synthesized by PVD based processes. The aim of the new contact material combination will be to provide greater freedom for substrate choice together with building high performance contacts with necessary electrical properties without the use of gold.

Project partners:

Elplatek A/S

Widex A/S

Tribology Center, DTI

 

This project is funded by Danish Agency for Science, Technology, and Innovation, Ministry of Science, Innovation, and higher education.