ESD protection guide
ESD Protection Guide
ESD stands for Electrostatic Discharge. It refers to the transfer of electrical charge between two objects caused by direct contact or a difference in electrical potential between them. ESD can occur in a variety of environments and can be caused by various factors, such as friction, separation, or induction. When electrical discharge occurs in electronic devices, it can cause damage to the delicate components and circuits, potentially leading to failure or malfunctions. ESD is a major concern in the electronics industry, and measures are taken to prevent and control it, including the use of ESD-safe materials and practices, such as grounding and the use of ESD-safe workstations and equipment.
Our aim is to help you understand what ESD protection is and what methods you can use to minimise the risk of electrostatic damage to sensitive components. We will also answer several common questions around the wider issue of ESD-aware electronics handling.
By the end of this guide, you should have a clear view of exactly what ESD protection means in practice. You will also be aware of various methods and products used for effective electrostatic discharge protection, as well as the types of training required to improve ESD control handling procedures.
What is ESD Protection?
ESD protection is the process of helping to guard sensitive electronic devices and components against the potentially damaging effects of electrostatic discharge. Wherever you are in direct physical contact with electronics, circuitry and other high-tech assemblies, you will need to be aware of the potential impact of ESD events.
In short, ESD is effectively like a mini lightning strike on an electrical device. Depending on the amount of energy released and the sensitivity of the assembly involved, some ESD events can be entirely harmless. However, they can also cause a wide range of problems: reliability and performance issues, minor latent damage to individual components, melting/burnout, or even catastrophic failure of entire systems.
There are many facets to covering all the ESD protection basics. These include:
ESD control products
ESD-safe clothing and workwear
ESD protection training, and approved component handling techniques
What Causes Electrostatic Discharge?
ESD is caused by two surfaces, items or bodies that are at different levels of electrostatic charge coming into close enough contact with each other. When one is positively charged and the other negative - typically because of gradual charge build-up through friction - the protons and electrons that carry these charges will attempt to balance each other out by rapidly exchanging at the point of contact.
On a small scale, this is exactly what happens when you get a little shock from touching a doorknob or handrail, for example. On a much larger scale, it is also what is going on when you see thunder and lightning. Not only can ESD interfere with or irreparably damage sensitive electrical components even at fairly low charges, but it can also cause sparking that will ignite atmospheric gases at high enough concentrations.
Electronic components, devices and other products that are potentially vulnerable to the effects of ESD will usually be labelled as such. Rather than there being just one anti-static symbol to look out for, there are three main ESD-related symbols you ought to recognise when handling these types of products and circuits.
ESD Susceptibility Symbol
This is perhaps the most common one you will encounter on product packaging or in the workplace. Often highlighted in bright yellow or orange, it depicts a hand reaching into a triangle with a line drawn through it. This indicates that a device or assembly is likely to suffer damage from ESD events and advises caution along with proper ESD control measures when handling the item.
ESD Protective Symbol
This symbol looks like the susceptibility mark at first glance, but the differences are important. In this case, the hand reaching into the triangle has no slash through it, and instead, there is a bubble or arc depicted around and above the image. This indicates that a product is ESD Protective, meaning it offers at least one electrostatic discharge control feature designed to lower the risk of an ESD event.
ESD Common Point Ground Symbol
This symbol indicates the location of a common point ground - in other words, a device that has already been properly grounded, and which can be used to discharge any buildup of electrostatic harmlessly. Individuals handling an ESD-susceptible component should be able to connect themselves safely to this grounding point before making contact, and thus minimize the risk of an ESD event.
EPA, ESD Protected Area
If you want to avoid damage to electronics, component handling should take place in an EPA. An EPA is a defined space where all surfaces, objects, people and ESD Sensitive Devices (ESDS) are kept at the same electrical potential. This is achieved by simply using ‘groundable’ materials (i.e. materials with an electrical resistance typically of less than 109 ohms) for covering all surfaces, for containers and for tools. All surfaces, products and people are bonded to Ground, which means connecting them with a resistance of < 1 gigohm. Movable items (such as containers and tools) are bonded by virtue of standing on a bonded surface or being held by a bonded person. Everything that does not readily dissipate charge (an insulator), should be excluded from the EPA, except for when process essential, in which case Ionisation can be used.
An EPA could be anywhere from just one workstation, a room, or a whole factory floor. It can even be portable, perhaps in a field service situation.
ESD Control Products
Among the most widely used and most popular products are some relatively basic items, such as anti-static bags and ESD wristbands. Depending on the criticality of minimizing the risk of static build-up and discharge, you can build a much larger ESD control system involving dozens of related products.Below, you will find some of the most common ESD control products. You can contact Emt4u and we will help guide you to make sure your ESD Protection project will be successful.