Strain measurement in thermal shock testing

We would like to present the results of strain measurements conducted by attaching strain gauges and thermometers to the surfaces of power modules, both in the mounted state on a circuit board and in the unmounted state. In the mounted module, a slight delay in temperature change was observed, and correspondingly, the change in strain also appeared to be delayed. This is believed to be due to the slower transfer of heat to the module when it is mounted. At Aites, we conduct temperature cycle tests and temperature-humidity cycle tests, during which we can simultaneously measure the strain occurring in the mounted components. Please feel free to consult with us.

We would like to introduce the results of our investigation into the behavior of strain during moisture absorption and drying using a strain gauge. It was observed that the material expands when it absorbs moisture due to humidification, contracts when it dries due to dehumidification, and the strain returns to the state before humidification. Regarding FR-1, it is presumed that the chemical structure of the material changed due to hydrolysis, which is why it did not return to its original state.

We would like to introduce the "strain measurement in thermal shock testing" conducted by our company. A sample with strain gauges attached was set up in the thermal shock testing device, and the wiring of the strain gauges was connected to an external data logger to record strain data in real time during the test. For two types of copper-clad laminates, the strain behavior during the thermal shock test was observed, and it was noted that significant strain occurred with changes in temperature. It was found that FR-1 exhibited greater strain compared to FR-4.