Reliability testing is an activity to ensure that the product maintains its functional reliability during the expected life of the product under all the environments of expected use, transportation and storage. It is to expose the product to natural or artificial environmental conditions to experience its effects, in order to evaluate the function of the product under the environmental conditions of actual use, transportation and storage, and to analyze and study the degree of influence of environmental factors and the effect mechanism. Through the use of various environmental test equipment to imitate the conditions of high temperature, low temperature, high temperature water humidity, and sudden changes in humidity in the climate environment, to speed up the reaction of the product in the operating environment, to verify whether it has reached the expectations in R&D, planning, and manufacturing. The quality target is used to evaluate the entire product to confirm the reliability and life of the product.

The reliability test items required for SMT lead-free solder joints are:

1. Vibration test

2. Shock test

3. Thermal shock test

4. HALT test

5. Thermal and humidity test

Basically, after the above tests, the reliability of lead-free solder joints can be checked.