Here, in Electricite De France, our field return shows that ESD/EOS represent around 30% of our root causes of failure. It is the feature that one can find in much papers (ex : Component Quality and Reliability, Intel 1992). Discussions with other users lead to the same conclusions. The point is to know if the cause is an ESD or an EOS. We have no idea for our equipment. However, it seems to be possible to identify the signature of both causes even if their are very similar (???). You'll find some interesting datas in "ESD in Silicon integrated circuits" (A. Amerasekera, Ed. Wiley, 1995). some other field data from other technetters...? Chris [log in to unmask] on 11/04/2001 16:39:00 Pour : [log in to unmask]@hub cc : (ccc : Christophe CROCOMBETTE/ERMEL/DER/EDFGDF/FR) Objet : Re: [TN] ESD consequences As with many things the consequences of creating ESD damage depends on what you do and who you do it to. [From our ESD Awareness Training .] Problem #1 with ESD. Our day-to-day activities produce tremendous charges. Electrostatic voltage (v) Static generation process at 10 to 20% RH at 65 to 95% RH Walking on carpet 35,000 1,500 Walking on vinyl flooring 12,000 250 Worker sitting at a work bench 6,000 700 Handling a vinyl envelope used for work instructions 7,000 600 Picking-up a sandwich plastic bag from a bench 20,000 1,200 Sitting at polyurethane cushioned bench 18,000 1,500 . And the level of charge generated varies with the relative humidity (RH) level. This variability caused by humidity helps explain why we seem to get more "carpet shocks" in the winter, when the air is dry, than in the summer, when the air is moist. This is because most common insulating materials such as wood, fabric, paper, or masonry contain a certain amount of moisture, which is dependent on the relative humidity of the air. To some extent, the moisture content, in turn, affects the conductivity of these materials and their ability to hold static charges. Relative humidity Conductivity Higher >50% More conductive Lower <30% More insulating Logically, it would follow that high humidity would be an effective means of controlling static electricity. High humidity: . Still allows generation of unacceptable charges, even though not a large as low humidity. . Contributes to other problems including oxidation and soldering difficulties. . Is uncomfortable and expensive to generate. Problem #2 with ESD. We can not easily see, smell or feel ESD. Perception Body's electrostatic voltage (volts) Not felt when touched at the back of the finger Below 500 Slight sensation when touched at back of finger Above 1,000 Not felt on index finger when touching Below 2,500 Slight sensation on index finger when touching Below 3,000 Audible discharge Above 5,000 Visible spark Above 10,000 Problem #3 with ESD. Electronic components are very sensitive. Components can be easily damaged by voltages that we can not sense. The breakdown voltage is the voltage level that causes damage to the component. Device type Breakdown voltage (v) Device type Breakdown voltage (v) VMOS 30 to 1,800 Bipolar transistor 380 to 7,000 GaAsFET 100 to 300 Junction FET 140 to 10,000 EPROM 100 OP AMP 190 to 2,500 CMOS RAM 250 to 2,000 ECL 500 to 1,500 Schottky diode 300 to 2,500 SCR 680 to 1,000 Schottky TTL 100 to 2,500 Film resistor 300 to 3,000 Note that at 1/4 of the breakdown voltage shown, these parts can still be damaged even though they may pass the manufacturers' specifications when tested, but the damage may cause them to fail earlier than normal in the field. Problem #4 with ESD. Electrostatic discharge events are often imperceptible, causing: Delayed Failure. Electrostatic discharge may damage a device or change its characteristics without causing immediate failure. The device may pass inspection, move into the market, then fail during its initial period of use. Difficulty In Identifying Discharge Site. Humans generally cannot perceive electrostatic discharges of under 3000V, while semiconductor devices can sustain damage from electrostatic voltages as low as 100V. It is often very difficult to locate the process at which electrostatic problems are occurring. Result of these problems: ESD causes billions of dollars in damage each year. ----- Original Message ----- From: Bissonnette, Jean-Francois To: [log in to unmask] Sent: Wednesday, April 11, 2001 5:10 AM Subject: [TN] ESD consequences Hello Technetters, I'm looking for statistics on ESD consequences on electronic equipment. Such as % of field failures due to ESD and that kind of stuff. Anyone as a good source to suggest?? Thanks! JF WABTEC CORPORATION CONFIDENTIALITY NOTE The content contained in this e-mail transmission is legally privileged and confidential information intended only for the use of the individual or entity named herein. 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