IEC 60747-5-13-2021 pdf Semiconductor devices – Part 5-13: Optoelectronic devices – Hydrogen sulphide corrosion test for LED packages

4 Test apparatus General 4.1 The test apparatus consists of a climatic system, test enclosure, gas delivery system and means for measuring gas concentration, detailed in IEC 60068-2-60:2015, Annex B. Details of design and construction are optional but shall be such that the conditions specified for the method are fulfilled throughout the working volume and shall comply with the following requirements: water droplets or aerosols shall not be injected into the test enclosure; air and water used shall be sufficiently clean in order not to affect performance of the test; the test atmosphere shall flow through the enclosure in such a manner as to ensure uniform test conditions within the working volume; the sampling point for gas analyses shall be in the working volume of the test enclosure; the exhaust gases shall be treated in accordance with the relevant regulatory stipulations; the wet bulb pod shall be placed in the test chamber in such a manner not to exceed 0,1 % of the cross-section of the test chamber. 4.2 Test jig If jigs are used to set specimens under test, the jigs shall be made of corrosion-free materials (e.g. UPVC tube, PTFE, glass, etc.). The jigs shall also allow air to pass through easily enough so that the wind speed in the test enclosure is not influenced significantly. 4.3 Test setup If multiple specimens are tested, each specimen shall be set in the same posture. See Figure 1 as an example. The distance between specimens should be 10 mm or more. Corrosive materials or objects including corrosive materials (e.g. silver) other than the test specimens shall not be set in the test enclosure.
7 Method 7.1 Initial measurements The relevant specification may require that, before and after test, a luminous/radiant flux measurement be carried out in combination with an electric measurement. Unless otherwise specified in the relevant specification, the luminous/radiant flux measurement and the electric measurements shall be conducted in accordance with IEC 60747-5-6 or CIE 127. 7.2 Procedure Prior to the commencement of the test, it shall be established by suitable measurements that stable conditions for the concentration of hydrogen sulphide and nitrogen dioxide, temperature, and relative humidity have been achieved. Periodic checks for temperature and relative humidity shall be made during the test to ensure that these conditions are maintained. Care shall be taken that the specimens are placed in a way so that they do not come in contact with each other, that they do not cover or shield each other from the test atmosphere, and that they do not shield air flow in the test chamber significantly.