Electronics in harsh environments - product verification and validation

The demand for robust electronics is continuously increasing, as electronics is used in almost any products and placed everywhere. The customer expects industrial products to operate at least 5 years without failures, no matter the location. In order to be able to design products which are robust against harsh environments, the specific conditions at the customers must be known and understood. Following, the requirements for the entire product and the single parts must be specified properly. The final product shall be able to pass robustness tests, such as aggressive gases, humidity and contamination. Requirements to the suppliers of single parts and components shall include cleanliness and lifetime data in harsh environments. Danfoss has developed a simple three step 'aggressive sub 3' test procedure for new products, which involves exposure in salt mist, aggressive gasses and cyclic humidity. These tests show good conformity with real life scenarios, but exact acceleration factors relative to the customer environment can not be established, since too many factors are unknown. However it is possible to make life tests with various stress levels and thereby determine acceleration factors for single or few stressors. Other 'must' tests are dust tests, condensing humidity tests and temperature cycling. It is also very important to analyze market feed-backs and thereby get more knowledge about the customers and the products, to be able to make ongoing improvements.