Environmental testing in a high-power constant temperature and humidity chamber.

Our company conducts "rubber thermal aging tests" that help evaluate the properties of materials in actual usage environments. Using a method compliant with JIS K6257 (Method for determining thermal aging characteristics of vulcanized rubber and thermoplastic rubber), rubber test pieces are suspended in a gear oven to create specimens with varying heat treatment times. Additionally, tensile tests are performed on heated natural rubber (NR) to investigate changes in mechanical properties, while hardness is measured simultaneously. Changes in the characteristics of the rubber are also examined, confirming that rubber elasticity is lost and the material becomes harder with heating.

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.

Our company conducts environmental testing using a constant temperature and humidity chamber with a front glass window and a camera, allowing us to capture and monitor the operational status, such as screen displays, during the tests. During environmental testing using equipment like constant temperature and humidity chambers, monitoring the condition of the test subjects with loggers (for voltage, current, resistance, temperature, etc.) is widely practiced. However, monitoring the operational status of equipment during testing can be difficult unless the test equipment is equipped with dedicated external outputs. For samples where monitoring with loggers is challenging, we combine a constant temperature and humidity chamber with a front glass window option, a camera, and monitoring software to conduct environmental tests while capturing and monitoring the condition of the test equipment.

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.