ESS (Environmental Stress Screening) Environmental Stress Screening Tests

Environmental stress scanning (ESS) refers to the process of forcing a newly manufactured or repaired product or component (usually an electronic product) to stresses such as thermal cycling and vibration, forcing hidden defects to manifest themselves as permanent or destructive failures. These tests are performed by exposing a newly manufactured product to environmental stresses to identify and eliminate hidden defects that arise during the manufacturing process.

Environmental stress screening testing is part of the manufacturing process and is performed on all manufactured products. Technically, this test method was originally developed by the military to reduce the number of defects that occur in the manufacturing process of complex electronic assemblies. The testing process includes many temperature and vibration cycles, often at extreme limits, from providing a basic check of the electronic system prior to shipment to applying much stronger environmental profiles.

The benefits of such screening depend on the maturity of the manufacturing process and more mature processes are expected to produce fewer defects.

A number of different methods exist for environmental stress screening (ESS) tests. Traditionally, these methods have been determined by requirements contained in military standards such as DOD-HDBK-344 Environmental stress screening of electronic equipment, and regulations published by the Institute of Environmental Science and Technology.

In general, the criteria taken into account in these tests are:

• thermal cycle display
  • temperature change rate
  • Temperature waiting time
  • temperature cycles
  • Equipment operation
  • Off during cooling
  • Equipment monitoring
  • Electrical test after shielding
• Random vibration
  • acceleration level
  • Frequency limits
  • Series or synchronously excited axes
  • Vibration time
  • power on/off
  • Equipment monitoring

Designed to help electronics manufacturers detect product defects and manufacturing defects, environmental stress screening testing is widely used in military and aerospace applications, less so for commercial products. These tests typically include:

• temperature changes
• Vibration tests
• Print tests
• Flexibility tests

Our organization also provides environmental stress screening testing services with its trained and expert staff and advanced technological equipment, among the numerous test, measurement, analysis and evaluation studies it provides for businesses in various sectors.