Love not only goes through the stomach, but also seems to be able to discharge itself electrically. After all, there is a rumor in the relevant circles that an (older) computer - as they say: old barns burn well - had a crush on a shapely young lady years ago. Every time she walked through the room, all the lights started flashing and flickering. As it turned out, however, it wasn't the lady herself but her nylon underwear that was causing the computer problems - we'll leave aside how that was discovered.
True or not true, this anecdote should at least provide some material for discussion among feminists. Electronic manufacturing is probably less about love and more about damage to components and assemblies and, more recently, the resulting defects in the finished device. This can make your hair stand on end from time to time, as is indeed possible when visiting one of the many science museums. But you have to stand on a well-insulating surface and never move away from it too soon.
What is experienced as fun in the museum is bitterly serious on the production line and a real nuisance at home on the sofa. Wherever ESD protection has been neglected or overlooked, the infamous spark can occur or an unnoticed discharge can occur, which can then damage the product.
It doesn't take much to cause damage to the most sensitive components. While people only feel the discharge from around a few thousand volts, components and devices can be damaged by far less. The discharge is typically very fast, lasting only a few nanoseconds, and this is one of the problems. This is because the short time ensures that the current is very high for a short time, which suddenly generates a lot of heat locally.
But it's not just the production department that is now worried. The Internet is full of inquiries about whether a cell phone, for example, can be damaged by ESD. What about the touch-sensitive button or the screen?
To understand the whole process a little better, let's go back in history. In 1671, Otto von Guericke [1] sent a sulphur sphere he had been experimenting with to Gottfried Wilhelm Leibniz [2]. Mr. Leibniz used it to produce the first artificially generated electric spark and thus gave the starting signal for further research into electricity. (It is not known whether the Egyptians and Greeks had already achieved this with amber). Two small devices were developed from this sphere: the induction machine and the Van de Graaff generator, which could be played with extensively in physics lessons.
Fig. 2: A girl holds her hand to a Van de Graaff in the Science City of Dhapa, Kolkata.
This charges her with high voltage, and as the charge in her hair repels each other, it stands on end
Fig. 3: Van de Graaff generator from 2013 for school lessons
Fig. 4: Diagram of a simple Van de Graaff generator
Fig. 5: Under the influence of a charged body, a charge separation occurs on a neutral body: InfluenceWhilethe Van de Graaff utilizes the triboelectric effect, influence machines rely on the spatial displacement of electric charges through the influence of an electric field.
However, both are based on the principle of frictional electricity, according to which when certain substances (e.g. sulphur, glass, wood and rubber) are separated, one becomes negatively charged and the other positively charged.
Although the industry has dealt extensively with the problem of electrical discharge during production, the attitude in the design of devices must also slowly change, because it is finally becoming known that the consumer poses the greatest danger to his beloved cell phone [3]. Since such instruments - and not just cell phones - contain ESD-sensitive components, the device can fail simply by touching it, as the increasing number of reports on the Internet now demonstrate.
More and more people are wondering why some of the buttons or sockets on their device have suddenly given up the ghost. It is not unlikely that, as the devil would have it, a discharge has bypassed the protective circuit, if it is still present at all. Statistical surveys indicate that typically around a third of all consumer failures are due to ESD damage [4]. However, detection is very time-consuming and therefore expensive. At normal magnification, nothing can usually be seen. Microscopes with 1000× or 1500× magnification may make something visible, but layers often have to be removed and etching carried out before the fault can be diagnosed as ESD damage [5].
The normal consumer is often unaware of what is happening. If they walk over a plastic carpet or loll on a sofa, they can become charged due to friction, which can be favored by several factors. Low humidity and the material can intensify the effect and his clothes can become charged to several thousand volts.
The problem has to do with the ever smaller products and the ever smaller structures in the processors, as this has prompted manufacturers to eliminate the previously planned protective circuits in the chips for reasons of space. The costs incurred as well as the space on the silicon chips can hardly be compensated for by other measures.
As the devices are then exposed to higher ESD incidents at the user's premises than in largely controlled production, this has proven to be a shortcoming.
Most IC manufacturers test their products in accordance with MIL-STD-883, Method 3015: Human Body Model (HBM), as this test method relates directly to production, and so 500 V is used in the test. Of course, you could also use a more stringent protocol, such as that recommended by the International Electrotechnical Commission (IEC), IEC 61000-4-2. Then you can get down to business with at least 8,000 V.
An IC that passes the MIL-STD may well fail the IEC if ESD protection is not also included, whereby the trend for the test voltage is slowly being corrected upwards: 20,000 V or even 30,000 V?
As this is becoming an increasingly precarious situation that could damage the reputation of major brand names, designers need to come up with something quickly. There are known measures, but new ones must be considered [6], especially as the designer must protect the device against both negative and positive ESD events.
We'll leave the details to the designer [7], but the idea of enclosing the entire device in a Faraday cage would be feasible, although modern devices are not usually encased in metal. The effectiveness of such a cage is demonstrated by airplanes that are struck by lightning.
If lightning strikes an airplane, people inside remain safe because the electric field strength is considerably lower inside than outside due to the metal casing. However, near openings in the metal shell, an external field penetrates into the shielded space.
Fig. 6: The world's largest electrostatic generator in the Teylers Museum in Haarlem, Netherlands
Fig. 7: Friction electrifying machine with glass sphere
References
[1] 1602 - 1686.
[2] 1646 - 1716.
[3] Phillip Havens, Chad Marak; May 2, 2014.
[4] Sanjay Agarwal; February 6, 2014.
[5] http://slideplayer.com/slide/5807601/ (Retrieved: March 20, 2025).
[6] Jerry Twomey; Protect Your Fortress From ESD; August 9, 2012.
[7] Ken Michaels; Electrostatic Discharge: Causes, Effects, and Solutions; September 1, 1999.
