One of the most important requirements in recent years has been the long-term reliability of the circuit substrate. The foremost reason for this is due to the demanding operating conditions in the automobile sector. Factors such as temperature and vibration are important influencing variables in this respect. The increased service life of the vehicle also demands longer-term reliability of electronic components. Other areas of industry such as avionics, medical engineering and industrial electronics are following this trend. Besides the thermo-mechanical resilience of the interlayer connections, the resistance to creepage currents and short-circuits under humid operating conditions are being focused on.
KSG Leiterplatten GmbH takes an active role in this development and is involved in focussed collaboration in appropriate research projects. This is evidenced by, among other things, the brisk collaboration with the expert groups within the ZVEI, for example in the working group for „circuit board reliability“.
The company is also committed to development: numerous projects are involved with the adaptation of the production processes and the materials deployed in close collaboration with the supply industry. The objective is to recognise the complex relationship between the fatigue behaviour of the bonding and the manufacturing technologies and process parameters and/or the materials deployed. Based on these results, measures for optimising the processes will be derived. The same applies to the clarification and prevention of migration phenomena under simulated operating loads.
This process is accompanied by a continuous expansion of the metrological equipment in the reliability laboratory. Within the scope of the BMWi funded project „contact“ an online resistance measuring station has been set up by means of which sheath damage under temperature fluctuation stress can be revealed with a detection threshold of under 3%. After completion of the examination, an informed prognosis on the service life of a circuit board can be made for the first time taking into account the technology and materials used.
A further measurement station for measuring leakage currents and insulation resistances for the evaluation of circuit board structures under humid load conditions was commissioned at the start of 2014. In this regard, for SIR and CAF evaluations, load voltages of between 5 and 200V are possible to create climatic stress within the range of 10-98°C / 10-90% relative humidity.