10 Myths of Electro Static Discharge ( ESD ) in Electronic Manufacturing
Although most people may have heard about electrostatic discharge (ESD), they may nevertheless entertain perceptions that are not accurate. In fact, even people who work in manufacturing sometimes succumb to misinformation (or a lack of knowledge) about ESD.
Because electrostatic discharge is such an important and prevalent phenomenon, everyone needs to know about these myths.
What Are Ten Such Myths?
1) Electrostatic discharge is a relatively-modern problem.
Actually, going back into the 1400s, care had to be taken to protect against black-powder mishaps at munitions facilities. Forts in the Caribbean and in Europe, therefore, instituted early forms of ESD control.
2) ESD is only an issue with PCB, explosives and sawdust facilities.
In reality, most manufacturing facilities have to keep an eye on ESD, especially in regards to electronic products/equipment.
3) ESD problems are a rare phenomenon.
Many times items are damaged or disrupted by ESD and, because no outward signs are present, people remain unaware of the damage. These disruptions are very common.
4) Discharging fingers/tools before using them obviates any potential ESD mishaps.
Unless the user are perfectly still, the human body (and tools) can rebuild a charge. This is not a suitable (per se) control option.
5) Once products are mounted on circuit boards, ESD mishaps cannot occur.
Just because components are mounted on circuit boards does not remove ESD dangers. In fact, charges may be more easily channeled to sensitive parts once circuit boards are involved.
6) Only circuit boards with complementary metal oxide semi-conductor (CMOS) are subject to ESD issues.
While most circuit boards contain CMOS-components, all circuit boards are susceptible (in one way or another) to ESD damage
7) One has to touch an item to transmit an ESD to it.
Actually, all that is needed is bringing the item near an electrostatic field to create potential ESD problems.
8) An item that passes a peremptory test after a potential ESD incident is probably okay.
Actually, damage as a result of ESD can manifest itself later or in ways that may be difficult to detect with any measuring device.
9) A printed wiring board (PWB) permanently protects a circuit board.
Actually, while the withstand-voltage may be increased with a PWB, it is no guarantee that ESD will not be a problem.
10) Grounded metal can provide a safe haven from ESD.
Static discharge can still reach or build on items mounted on or sitting on grounded metal.
Yet another myth is that there isn’t much you can do against ESD. Actually, a number of effective products can be used to protect against ESD, including anti-ESD wrist straps, mats, chairs, casters, sealed barrier bags, non-conducting materials, etc.
While it may be impossible to completely protect against ESD, precautions can be taken which greatly reduce chances for mishaps. By knowing what to do and not succumbing to popular myths, you can help reduce the chances for ESD damage to sensitive, expensive equipment and components.