Power cycling: Realistic assessment of thermo-mechanical stresses

In power electronics products and battery cells, temperature changes lead to gap changes within the assembly. These thermally induced movements generate tensile and compressive forces that act directly on the thermal interface material (TIM). In addition, so-called CTE mismatch effects cause shear forces due to different temperature-related expansions of the TIM and the carrier material.

Elevated temperatures also promote oxidation processes, viscosity changes, and other aging effects in the TIM, which can lead to component failure in the long term.

With ZFW Power Cycling, these thermo-mechanical influences can be combined and examined in an application-oriented manner. Temperature cycles from a minimum of -40 °C to a maximum of 175 °C are realized. On this basis, qualitative and quantitative statements can be made about the change in thermal resistance as a function of the number of cycles.

The ZFW multiparameter test bench can test up to six samples or materials simultaneously, enabling reliable statistical evaluations.

Please contact us to discuss your requirements and create a customized power cycling test plan.

Microthermography makes thermal resistance visible

Thin bonding layers play a decisive role in the thermal performance of modern electronic systems, but can often only be characterized to a limited extent using conventional measurement methods.

In the current issue of ELEKTRONIKPRAXIS, we show how a microthermographic measurement method developed at ZFW closes this gap: High-resolution infrared thermography allows thermal resistances to be measured directly at thin interfaces and evaluated in detail for the first time.

The method enables a realistic evaluation of connection and interface technologies such as bonding, soldering, or sintering and provides reliable data for material selection, design decisions, and thermal simulations.

Read the technical article to learn how microthermography provides new insights into thermal transition resistances and why it is a crucial component for optimizing power electronic systems.