Climate Chamber Tester

 

Thermal cycling test

Purpose

To determine the ability of the module to withstand thermal mismatch, fatigue and other stresses caused by repeated changes of temperature.

Apparatus

  1. a) A climatic chamber with automatic temperature control means for circulating the air inside and means to avoid condensation on the module during the test, capable of subjecting one or more modules to the thermal cycle in Figure shown in the following pages.
  2. b) Means for mounting or supporting the module(s) in the chamber, so as to allow free circulation of the surrounding air. The thermal conduction of the mount or support shall below, so that, for practical purposes, the module(s) are thermally isolated.
  3. c) Means for measuring and recording the temperature of the module(s) to an accuracy of±1 °C.
  4. d) Means for monitoring, throughout the test, the continuity of the internal circuit of each module.

Procedure

  1. a) Install the module(s) at room temperature in the chamber.
  2. b) Connect the temperature monitoring equipment to the temperature sensor(s). The temperature sensors shall be attached to the front or back surface of the module, near the middle. If more than one module is tested simultaneously, it will suffice to monitor the temperature of one representative sample.
  3. c) Close the chamber and, subject the module(s) to cycling between module temperatures of–40 °C ± 2 °C and +85 °C ± 2 °C, in accordance with the profile in Figure 4. The rate of change of temperature between the low and high extremes shall not exceed 100 °C/h and the module temperature shall remain stable at each extreme for a period of at least10 min. The cycle time shall not exceed 6 h. The number of cycles shall be as shown in the relevant blocks in Figure in the following pages.
  4. d) Throughout the test, record the module temperature and monitor the continuity of the modules.

Final measurements

After a minimum recovery time of 1 h, repeat test 10.1 and 10.3.

Requirements

– No evidence of major visual defects, as defined in Clause 7.

– Insulation resistance shall meet the same requirements as for the initial measurements.

– No open circuits during the course of the test.