The power silicon in SKiiP 4 modules can be operated at a junction temperature of up to 175°C. To ensure that these high temperatures can be used reliably, the semiconductor chips are not soldered to the ceramic substrate but are joined using sinter technology, meaning that higher operating temperatures are possible with no reduction in – or in some cases even increased – reliability. The sinter bond is a thin silver layer that has a lower thermal resistance than a solder bond. The high melting point of silver prevents premature material fatigue. Power cycling is two to three times greater than that of soldered base-plate modules. In practice this means greater reliability in the field, as well as lower service costs.

A solder-free pressure contact system uses mechanical pressure to press the direct-bonded copper (DBC) substrate to the heat sink without soldering. This results in a homogenous pressure distribution with a thermal connection between the ceramic substrates carrying the semiconductor chips and the heat sink. Thermal resistance is 40 percent lower than standard modules and thermal cycling capability is five times higher than a module with base plate.

The integrated gate driver in the SKiiP 4 sets new standards of reliability and functionality. The digital driver guarantees safe isolation between the primary and secondary side for both switching signals and all measurement parameters, such as temperature and DC link voltage. Users therefore do not need to add complex and costly circuit components to provide safe isolation. The SKiiP driver features a CANopen diagnosis channel – a first in a power module – which enables access to an error memory, allowing errors in the SKiiP 4 to be quickly identified and saved for later diagnosis.

Today, many decentralised power supply systems are monitored for errors remotely. The CANopen interface facilitates the integration of diagnosis functions into the remote monitoring system. Even without direct integration of the CAN interface into the controller, this feature is very useful for on-site service and maintenance.

A range of settings in the SKiiP 4 driver can be adjusted. For example, the switching threshold can be adapted to the given application for DC link voltage monitoring purposes.

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