How can Electrostatic Discharge (ESD) be Controlled?

ESD also known as Electro-Static Discharge is the discharge of electric Current from a statically charged Body to a neutral body / Oppositely charged body. Typically, we do experience Electrostatic Discharge in our day-to-day life, ex. Getting a shock when a woollen cloth is touched, it is considered as harmless. But, when it comes to working on sensitive electronics, ICs , chips or even flammable liquids like petroleum, it can cause tremendous harm.

How is Static Charge Formed

Static charges are formed when two surfaces rub against each other. You must have done this magic once in your life, where you rub a comb on your head and attract pieces of paper. This is all done because of static charges. When comb is rub on the head, it gets negatively charged while hairs get positively charged (because it loses electrons to the comb). This is how static charges are formed.

Methods of detection of Static Charges

There are several methods by which static charges can be detected. Only if the need is for detection, we can use natural methods. But if there is a need of detection with the magnitude, we would need some very sophisticated instruments for that. The methods include:

Natural methods

By Bringing the charged object to a neutral body, we can see that it starts attracting towards the charged body. For Eg. When a charged comb is placed near a water stream, it bends towards it.

Using an Electroscope

An Electroscope is a very simple apparatus for detecting static charges. It includes a thin conducting wire piercing through a cork into a glass bottle. The end of the wire inside the bottle is curved with two thin foil sheets being pierced in it and separated by some distance.

When a charged body touches the end of the wire outside the bottle, the charges transfer straight into the bottle and upto the foil sheets. The sheets then starts getting repelled from each other, since both are getting same charges. This indicates the detection of charged body.

Using metering devices

There are some devices that not only can detect but also can find out magnitude of charge. Static meters can measure the charges in kilo-volts by just touching it to the object. Another advanced device can measure the charges without even touching! It uses laser technology to collect the information about charges. Devices like Simco Ion FMX-004 meter are used to measure the charges.

Advantages / Disadvantages

The disadvantages of static charges include:

• Static charges are dangerous for environments having volatile inflammable materials. These charges can ignite the material putting the site under risk of fire.
• The charges are main reason behind the loss of electronic components like chips, SMDs, Motherboards etc , due to a phenomena called ESD.
• If accumulated in large quantities, the shocks produced can be fatal to human life also.

Though, static charges are mostly seen as problem causers, they are not that always. Modern technology has found ways to make them work in our favour also. Thus, their advantages are:

• Static charges are used for printing. Yes, that’s right. Laser printers use static electricity extensively to print toner powder on paper.
• The touch screen technology we are using today in mobile phones, tablets, laptops etc. use static charge to detect the intensity and location of the touch.
• Air filters and dust removers purify air due to static electricity. They do so by polarising the air. This causes pollutants to attract towards filters, thus separating them out of the air.

What is Electro Static Discharge (ESD)?

Electro Static Discharge (ESD) is a phenomenon in which static charges are discharged in the form of electric current. It happens from a charged body to a neutral body or between two oppositely charged bodies.

When a body becomes so charged that the potential difference between the two bodies goes higher than the limit of the breakdown voltage (relative permittivity) of the in-between medium, the electric field rips-off the electrons from the molecules of the medium, thus forming a conductive way between the bodies. This completes the circuit and discharge of electric charges occurs. The best example of ESD is the Lightning in the sky.

Ways to control ESD

ESD can be quite mischievous to our trade and business. This can destroy our valuable and expensive electronic products in no time and that too without letting us know. To control this unwanted process to happen, we can:

• Using proper grounding systems can prevent ESD to happen. When excess static charges are grounded, the possibility of ESD gets eliminated. So, connect your apparatus to the ground.
• Using Anti-Static products like Anti-Static Mats, tiles, ESD apparels like gloves. If anyone cannot afford these, ESD wristbands can also work for that. Use antistatic bags to store expensive products.
• Increasing humidity levels of environment discourages the phenomenon. Dry places are more prone to ESD than wet and humid places.

Conclusion

We have seen that ESD can cause harm to our valuable and important equipments, cause them to misbehave, shorten their lives or worse can make them inactive. Taking proper measures against the beforehand can save our items from being destroyed. As the saying goes ‘prevention is better than cure’, there is no harm investing in the preventive measures against them.