1 / 5

Triboelectric charging occurs when two materials make contact and separate

What is ESD and where does it come from? – Triboelectric Charging. Triboelectric charging occurs when two materials make contact and separate Electrons from one material are transferred to another leaving one positively charged and the other negatively charged.

garret
Download Presentation

Triboelectric charging occurs when two materials make contact and separate

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. What is ESD and where does it come from? – Triboelectric Charging • Triboelectric charging occurs when two materials make contact and separate • Electrons from one material are transferred to another leaving one positively charged and the other negatively charged. • The nature of the materials will determine who losses or gains electrons • The build up of static electricity is determined by several factors such as: area of contact, the speed of separation, relative humidity, and chemistry of the materials, surface work function, etc. *Table from ESDA

  2. ESD Standards – Human Body Model, MIL-STD • Based on Skin-to-Metal Contact • e.g. Person touches pin of IC, discharging directly to pins • Used in Military Standard (883E) test specification • Addresses the Manufacturing/Production environment; testing is done directly on the IC • Circuit Model: Discharge VoltagePeak Current 500V 0.33A 1,000V 0.67A 2,000V 1.33A 4,000V 2.67A 8,000V 5.33A

  3. ESD Standards – IEC 61000-4-2 • Based on Metal-to-Metal Contact • e.g. Person with tool/key in hand discharges to I/O port • Used in IEC 61000-4-2 test specification • Addresses the user-environment; testing is done at the application or system level • Circuit Model: Discharge VoltagePeak Current 2,000V 7.5A 4,000V 15.0A 6,000V 22.5A 8,000V 30.0A

  4. ESD Standards – IEC 61000-4-2 Waveform • IEC 61000-4-2, continued • Discharge VoltageFirst PeakCurrent, 30nsCurrent, 60ns • 2,000 V7.5 A 4 A 2 A • 4,000 V 15.0 A 8 A 4 A • 6,000 V 22.5 A 12 A 6 A • 8,000 V 30.0 A 16 A 8 A • Specified current values, per discharge voltage Most all manufacturers test to 8kV or higher!

  5. Comparing the Two Specifications – IEC 61000-4-2 vs. Human Body Model Peak current Peak current Discharge VoltageHuman Body ModelIEC 61000-4-2 500 V 0.33 A 1,000 V 0.67 A 2,000 V 1.33 A 7.5 A 4,000 V 2.67 A 15.0 A 8,000 V 5.33 A 30.0 A • The key here is that a chipset that survives Human Body Model testing (in the manufacturing environment) is not guaranteed to survive in the field, where the exposure to ESD will be much more severe. • Different models yield much different peak current values; ultimately electrical stresses on the chipset are very different. • ESD levels in the field far exceed the values that can be generated in the manufacturing environment.

More Related