Application of three-box thermal shock test chamber

Temperature shock testing usually involves the rapid transfer of a product from one extreme temperature (e.g., high temperature) to another (e.g., low temperature) to evaluate its ability to withstand drastic changes in temperature.

“Passing through ambient temperature” refers to the use of a three-box thermal shock test chamber where the product passes through the ambient temperature zone (usually referred to as 20~25°C) before entering the target temperature zone when changing between high and low temperatures.

Especially when meeting the requirements of international standards such as IEC 60068 and MIL-STD, by setting up an intermediate room temperature chamber in the thermal shock test chamber, the time and temperature distribution of the product transitioning to room temperature can be accurately controlled and the consistency of the test can be effectively improved.

I. Why pass room temperature?

1. Simulate the real use of the environment

Three-box thermal shock test chamber can simulate a more realistic real-world environment. In many actual working conditions, products from high temperature to low temperature or vice versa, often first through a “normal temperature transition” process.

For example, electronic products may go from ambient to extreme temperatures during transportation or power-up, and “passing through ambient” can be more relevant to real-world scenarios.

Research in the journal Microelectronics Reliability points out that ambient temperature transition plays a significant buffering role in IC package stress management (Wong et al., 2018).

To achieve the simulation effect, the thermal shock test chamber provides adjustable temperature recovery paths to achieve gradient control of temperature stress.

2.Avoiding Thermal Shock Damage to Product Structure

Certain materials (e.g., ceramics, glass, welded joints) are prone to thermal expansion and contraction stress concentrations under drastic temperature differences, resulting in cracking, deformation, or failure.

Normal temperature transition can slow down the stress concentration and reduce the risk of damage.

According to the IEEE Transactions on Components, Packaging and Manufacturing Technology, brittle material interfaces are more prone to peeling when the temperature difference exceeds 80℃.

The application of thermal shock test chamber in this scenario can significantly reduce the failure rate, especially in the structure of complex composite products.

3. Improve the repeatability and safety of the test

Two-box thermal shock test chamber only high-temperature tank and low-temperature tank, directly from the high temperature to jump to the low temperature (or vice versa) impact is too fast, and can easily lead to uncontrollable risks, such as damage to the equipment, condensate generation and so on.

Three-box thermal shock test chamber, support for high temperature → room temperature → low temperature path automatically switch to realize the whole process of closed-loop control, to ensure that each impact path is consistent.

4. In line with certain international standards or industry specifications

MIL-STD or IEC standards, some tests specify that the temperature change path needs to include room temperature to ensure that the test results are representative.

Thermal shock test chamber can be accurately programmed to control the temperature change path according to MIL-STD-883J 1010.8 and IEC 60068-2-14, etc. TEMAK Thermal Shock Test Chamber supports PLC programming and data export, which is convenient for verification and tracking.

II. Comparison with “without ambient temperature”

When setting the conversion mode of the thermal shock test chamber, it can be customized according to the needs of product testing, whether “through the normal temperature” path, to increase flexibility in the test configuration. The three-box thermal shock test chamber is particularly suitable for “through the room temperature” environmental simulation test, its high-frequency valves and air duct switching design to optimize the conversion efficiency and temperature field stability.III.Whether “through the room temperature” selection basis

Product use: consumer electronics is more often used “through the room temperature”, military or aviation is more suitable for extreme impact. Thermal shock test chamber in consumer electronics, military level equipment can realize thousands of tests, covering all types of product verification needs.

Structural materials: Brittle materials are more suitable for “passing through room temperature” using a three-box thermal shock test chamber to minimize damage. Thermal shock test chamber temperature control accuracy (± 1 ℃) and wind speed uniformity to ensure that the temperature gradient control, suitable for brittle materials impact reliability assessment.

Customer or standard requirements: in accordance with the IEC, MIL, JEDEC and other specifications to determine the TEMAK thermal shock test chamber generally support the standard preset program, remote import standard template function, to facilitate the laboratory quickly get started.

Test purpose: to simulate the actual use, or to verify the limit of endurance.Thermal shock test chamber not only supports the conventional temperature shock, but also supports the limit rate (> 50 ℃ / min) liquid nitrogen assisted system, to adapt to the needs of higher-order verification.

The three-box thermal shock chamber is used to simulate scenarios closer to daily life, then ☞ two-box thermal shock test chamber commonly used in which scenarios, what are the structural advantages?