DIN EN 60749-4:2017-11

The suitability of semiconductor components for different applications also depends on the climatic and mechanical environmental influences to which these components are exposed. The DIN EN 60749 series of standards contains a large number of different test procedures for this purpose. This part of DIN EN 60749 describes the test procedure for constant damp heat with highly accelerated stress test for the purpose of evaluating the reliability of non-hermetic packaged semiconductor devices in humid environments. The HAST test procedure uses more stringent conditions for temperature, humidity and electrical stress in order to accelerate the penetration of moisture through the outer protective materials (compression molding compound or potting compound) or along the physical interfaces between the outer protective material and the metallic component connections that pass through it. The stress generally activates the same failure mechanisms as in the test procedure with constant heat and constant humidity according to DIN EN 60749-5. The test results of the long-term test procedure at constant humidity take precedence over those of the HAST test procedure. The present test procedure is destructive. This edition includes the following significant technical changes with respect to the previous edition DIN EN 60749-4:2003: a) clarification of requirements for temperature, relative humidity and duration detailed in Table 1; b) recommendations that current limiting resistor(s) be placed in the test set-up to prevent test board or DUT damage; c) allowance of additional time-to-test delay or return-to-stress delay. The responsible committee is DKE/K 631 "Halbleiterbauelemente" ("Semiconductor devices") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.