ANSI EIA 977 pdf free download

ANSI EIA 977 pdf free download.Test Method – Electronic P assive Components] Exposure to Atmospheric Sulfur.
3.5. Test Container – Any conveniently. -sized vessel of glass, polycarbonate, stainless steel (or any other material) that is not affected by sulfur vapor and elevated temperatures may be used as the test container. The size of the test samples will dictate the required size of the container. For small components such as chip resistors, a glass desiccator of 9 to 10L capacity will be sufficient. The vessel does not need to be hermetically sealed and may have a small vent opening (1 to 4 mm diameter hole) to allow equalization of pressure when elevated temperatures are present. 3.5.1. Large test containers – Larger vessels may be required to accommodate test boards and Printed Circuit Board Assemblies (PCAs). If a large test container is used and the silver coupon does not blacken (tarnish) from sulfur exposure within 24 hours (per the definition in Section 4.5), a larger diameter Petri dish and additional sulfur may be needed (Sections 5.1 and 5.2). 3.6 Convection Oven or Hot Plate – A convection oven or hot plate may be used to maintain the required temperature inside the test container. 3.7 Thermocouples – Thermocouples are used to monitor and control the temperature inside the test container. 3.8 Electrical Measurement Test Setup – A resistance bridge or multi-meter and appropriate test probes capable of providing component electrical measurements within specified tolerances. This setup shall apply 5% of the component s primary rating up to 50mW maximum (e.g., power for resistors, voltage for capacitors, current for inductors, etc.).4. GENERAL PROCEDURE 4.1. Choice of test procedure – The user and supplier must agree as to which of the two sets of test conditions will be applied, A or B. 4.2. Mounting – Unless otherwise specified in the individual specification or by customer request, test specimens shall be mounted to a printed wiring test board. If the components are to be placed as loose samples inside the test container, the surface of interest (typically those containing silver) should have unobstructed exposure to the sulfur environment. 4.3. Test sample documentation – All relevant parameters from the component placement and soldering operation shall be recorded, including but not limited to: solder and flux materials, soldering temperature or profile, and component placement method. 4.4. Test sample cleaning – After the components are soldered to the printed wiring board, the test specimens shall be cleaned in order to remove contamination that might affect the corrosion resistance results of the component itself. Cleaning requirements and conditions shall be adequate to remove all residual flux and ionic contamination. The cleaning requirements and conditions may be AABUS (as agreed by user and supplier). 4.5. Control sample – A silver coupon sample shall be suspended in the test container by a nylon line or other non-corroding material during the test to confirm the severity of the environment.ANSI EIA 977 pdf download.