The Design Challenges Involved in Miniaturization of Electromechanical Relays


52nd IEEE Holm Conference on Electrical Contacts

Dr. Morton Antler Lecture


Dr. Werner Johler, Senior Member IEEE

Tyco Electronics Logistics AG – Werk AXICOM Au

Seestr. 295

CH 8804 Au – Waedenswil, Switzerland


Electromechanical relays have been extremely successful on the market in the past years. They are reliable, robust, cost efficient and easy to use devices. This is astonishing as it has been told since semiconductor devices appeared on the market almost 50 years ago that electromechanical relays will disappear.

Reasons for this success are mainly the innovations the relay industry was able to introduce into new designs and to meet the needs of the electronic industry, telecommunication and automotive industry.

The major challenges have been the miniaturization of the relays, increasing the switching capability and reducing cost and make the products environmentally friendly at the same time.

When electromechanical relays are miniaturized following topics are of special interest and those are discussed:

-    Contact reliability at reduced contact forces and contact breaking forces

-    Prevention of internal and external contaminations – protection of relays

-    Handling material transfer and contact erosion at reduced contact gaps

-    Improving dielectric and isolation characteristics, while reducing creepage and clearance distances

-    Thermal characteristics caused by heat dissipation and increased ambient temperatures

-    Extended lifetime and switching capability

-    Increased reliability expectations from users

-    Limitations given by manufacturing

Introducing new technologies and new approaches to relay design will enable innovations in relay technology also in the future




WERNER JOHLER Werner Johler received his Ph.D. degree in electrical engineering from the Technical University of Vienna, Austria in 1988 and his MBA in 2003.

From 1984 to 1988 he was a scientific staff member at the Institute of Switchgear at the Technical University of Vienna. Since 1988 he has been with Tyco Electronics AXICOM in Au, Switzerland. He is Director for AXICOM relays. He has been Chairman of the Technical Committee TC94 “All or nothing relays” within CENELEC since 1999, member of the Board of Directors of IRSTC (International Relay and Switch Technology Conference) since 2002 (former NARM) and member of the board of the Swiss Information Technology Society since 2003. He received the Scientific Award from the state of Vorarlberg, Austria in 2004 and the Albert Keil Award from VDE in 2005.

He has published more than 60 papers on relay technology, miniaturization of electromechanical devices, contact physics and reliability of electromechanical relays