35% more compact inverters thanks to the combined use of SKiN and spring-contact technology / Greater system reliability achieved

SEMIKRON has successfully established its SKiN packaging technology and is now combining it with spring-contact technology for even better results. These two systems are used mainly in electric vehicle and wind turbine applications.  

SKiN technology is a flexible foil used in place of wire bonds and, in combination with sinter technology, can help double inverter power density, leading to a 35% reduction in inverter volume. This high power density requires space-saving and uncomplicated means of connecting the power components with the driver unit. The driver terminals thus use spring contacts affixed to the surface of the flexible foil. SEMIKRON looks back on ten years of experience with spring-contact technology, with more than 500 million SEMIKRON spring contacts in field applications today.  

Spring contacts are solder-free and affordable electrical connection technology. Module to PCB connection does not require sophisticated equipment – instead, the PCB is simply screwed onto the module, creating the electrical connections. A further benefit is that the connection can be easily undone at any time, resulting in service-friendly systems. Unlike solder joints featuring through-hole or press-fit technology, spring contacts are rather flexible as regards their positioning, facilitating PCB layout considerably. This delivers optimum, dynamic performance and removes the need for additional internal connections which might impair module reliability. The power terminals are not connected to the DC link using standard screw connections but are joined in a state-of-the-art laser welding process. This enables space-saving and reliable integration into the liquid-cooled inverter system. Thermal paste is responsible for around 30% of the overall thermal resistance in an electronic system, which is why it is a key factor in the electric and thermal dimensioning of a power electronics system. With SKiN technology, the thermal paste layer between the DCB and heat sink is replaced by a silver sinter layer, improving thermal conductivity between chip and heat sink by 35%.  

The key fields of application for SKiN technology in the future will be compact systems in the automotive and wind power sectors where liquid-cooled systems are used. The resultant compact, lightweight inverters will give our customers an important competitive edge. For instance, thanks to SKiN technology a 3 MW wind power converter can now fit in a single switch cabinet for the first time ever.    

About SKiN technology

Semikron recently unveiled a revolutionary new packaging solution for power electronics which does away entirely with bond wires, solder joints and thermal paste. The new SKiN technology replaces the wire bonds with a flexible foil, and the solder joints and thermal paste with sintered connections. The result is improved current carrying capacity and ten times the load cycling capability achievable with standard modules featuring limiting bond wires. This reliable and space-saving solution, which can reduce inverter volume by 35%, is ideal for inverters used in vehicle applications and wind turbines.     Figure: SKiN technology    


SEMIKRON is a leading global power semiconductor manufacturer. The German-based family enterprise employs 3900 people worldwide. A global network of 36 companies with production plants in Brazil, China, France, Germany, India, Italy, Korea, Slovakia, South Africa and USA guarantees fast and competent on-site customer care. SEMIKRON is a one-stop provider of chips, discrete semiconductors, transistor, diode and thyristor power modules, power assemblies and systems for markets such as industrial drives, wind and solar, hybrid and electric vehicles, the rail industry and power supply systems. SEMIKRON is the market leader in the field of diode/thyristor semiconductor modules, enjoying a 30% share of the worldwide market. (Source: IMS Research, The World Market for Power Semiconductor Discretes & Modules – 2011 Edition).

Our dedication to the hybrid and electric vehicle market is evident in the development and production of power semiconductors for this market, as well as in the majority take-over of Compact Dynamics GmbH, a development specialist for innovative control systems, the joint venture with drivetek, a provider for application-specific control technology, and the take-over of VePOINT, developing and producing inverters, DC/DC converters and chargers.