Humidity temperature cycle

The humidity test is designed to determine the effects of humidity on the product and assure that the product will meet published specifications while being subjected to high humidity conditions. This is an accelerated test to uncover failure modes in components, assemblies and process, which may appear in the field during normal service, while keeping test time at a minimum. Performance tests are made at various intervals of the test duration and each test must pass for the design to meet the requirements of this section.

Hygroscopic materials (e.g., printed circuit boards, molded plastics, sealed components, etc.) will absorb moisture proportional to the applied vapor pressure and time of application. Excessive moisture penetration may cause swelling of material or contamination actions, destroying functional ability as well as causing leakage paths between sensitive circuits, result when moisture reacts with trapped chemicals from construction processes causing corrosion or severe etching of metal surfaces. In some cases dendritic growth can cause short circuits or high voltage flashover between closely spaced traces or pin spacings. The following humidity test is designed to accelerate the occurrence of these failure mechanisms if they exist.

Temperature Environmental test

The purpose of temperature environmental test is that the good are shipped by various types of carriers and experience a wide range of storage temperatures, depending on the customer environment, hence the need for this kind of testing. Further, certain components and assemblies are sensitive to these temperature extremes and could be weakened due to induced stresses. Therefore, it is important that a logical sequence of testing be followed in order to observe these effects and assure the product’s performance under various temperature conditions and after temperature extremes have been applied.

(Note: This test didn’t include the humidity.)