The circumstances that cause stress failure are important for manufacturers and end users to understand. Electrical damage may occur on many electronic components by electrical overstress (EOS) or electrostatic discharge (ESD).
In some components, the two types of failures can look similar or identical. This document discusses ESD safety practices with a focus on Indium Gallium Nitride (InGaN) light emitting diodes (LEDs). InGaN LEDs are the new generation of blue and green devices. They are extremely sensitive to ESD damage.m Damaged devices can appear dim, dead, short, or with low Vf or Vr. Avago Technologies’ InGaN LEDs are classified as “Class 1x” and “Class 2”.
Other examples of “Class 1x” devices include unprotected MOS, junction field effect devices, and low power thin film resistors. For a more detailed explanation and general application of ESD sensitive devices, please review Avago Technologies document, A-5951-1589-1, Workmanship Specification for ESD control. It can be obtained through your local Avago Technologies representative or from www.avagotech.com.
1.1 Terms and Definitions
Antistatic: This term refers to the prevention of triboelectric charge generation. It is not a material type. Materials can be treated with an antistatic agent to reduce the generation of static charges. This property is not dependent upon material resistivity.
Charged Device Model (CDM): A mathematical representation which imitates the consequences of a part becoming charged by handling or improper packaging and is then being discharged. Since contact resistances are typically low in these cases, large, short duration currents can result, e.g. 10 amps for 1 ns (nanosecond).
Conductive: A physical property of material to allow charge movement. Charges move more freely in highly conductive materials. A static shielding enclosure (Faraday cage) requires use of conductive material. Defining standards are outlined in the Workmanship Specification for ESD Control.
Dissipative: A physical property of a material which allows charge movement. Dissipative materials conduct charges less freely than conductive materials. Defining standards are outlined in the Workmanship Specification for ESD Control.