Little bros, do still remember the hot TV series Descendants of the Sun?

 

 

The deepest impression to me is the looks of their first encounter -

The whole body is like being shocked by electricity, they couldn’t see anything else but each other.

This is the so called love at first sight, and the feeling of electric shock.

 

There is a kind of electric shock to make people frightened

Of course, not all of the electric shocks are so wonderful.

During the seasons of autumn and winter, there often appear such a scene in our life –

 

 

▶ When two people shake hands after meeting, when the fingers will suddenly feel the pricking like acupuncture after just touching each other, just like an electric shock.

 

▶ "Electric shock" occurs when you remove the sweater and jacket, and pull the door handle, with the "pa- pa" sound.

▶ Especially in winter, my hair will be like this –

 

 

We call the above phenomenon static.

Causes of statics

Simply speaking, any substance is composed of atoms.

Under normal conditions, the atomic number of atoms is the same as the number of electrons, the positive and negative charge have a balance, so there’s the phenomenon of non-charged externally.

 

However, when two different objects contact with each other, one of the objects lose some charge and another object gets this part of charge.

The original charge balance is broken, so there’s the electrostatic phenomena externally.

 

Then someone may ask, if any contact of different stuff can produce static electricity, so how about the air? As we rely on oxygen to survive, whether air contact can also produce static electricity?

The answer is yes.

Because the air is also composed of atomic combination, so it can be said that static electricity can occur at any time and place we live.

 

Static’s damage to the infrared touch screen

Nowadays, the function of various digital electronic products is getting more and more powerful, while the circuit board is getting smaller and smaller, with a higher integration degree, and the human-computer interaction has become normal.

 

 

Take the infrared touch screen as an example, as an interactive input device, there’ll surely exist the issue of the human body static.

 

According to tests:

When you feel the electric shock, the electrostatic voltage on your body is > 2000V

When you see the spark, then the electrostatic voltage on your body is > 5000V

But when you hear the "pa-pa" sound, congratulations, it has been up to 8000V!

 

 

Actually we do not have to worry too much, as the time of the static by the friction is very short, the amount of current generated is also very small, so generally it won’t cause danger to the human body.

 

But this short-term electric shock will damage the components on the circuit board of the infrared touch screen (e.g.: the heat generated by the current will lead to thermal failure of the device), and also very easily interfere the PCB board circuit, causing the product abnormalities, crash, and even other security issues.

 

 

So before a qualified infrared screen goes into the market, the national testing department will require it to conduct ESD (electrostatic discharge) test.

Where, requirements for the consumption level: the contact discharge needs to reach ± 4kV, and the air discharge needs to reach ± 8kV;

Requirements for the industrial grade: the contact discharge needs to reach ± 8kV, and the air discharge needs to reach ± 15kV;

 

This has put forward a higher demand for ESD design.

 

Next, my question is, during the whole process from infrared screens’ production to the delivery, how can ESD be designed to meet its standards?

 

 

Static Protection

Gu, production director of Shenzhen Zhenduodian Technology Co., Ltd. assumes that:

The work of electrostatic protection is a long-term system engineering, and the omission in any link may lead to failure to the work of electrostatic protection.

It is known that the infrared touch screen ESD performance by Zhenduodian Technology has reached industrial standards, and as a high-tech enterprise with six years and combining the R & D, production and sales of infrared touch screen, there’s no doubt for its ESD protection experience.

Gu had also generously shared with us some ESD protection experience:

 

 

"The reason why static electricity is particularly serious in the fall, is that the climate begins to get dry with a low humidity, dust in the air easily adhere to the surface of the object, to easily generate friction.”

"So, the production environment of the infrared screen is particularly important."

 

Forging of the dust-free plant

1. The production workshop floor applies the epoxy anti-static floor paint, so its surface is smooth, anti-moisture and wear-resisting, and the dust prevention is free from time, temperature, and humidity.

It can quickly excrete the electrostatic charge, to prevent accidents caused by static accumulation.

 

 

2. When entering the workshop, the operator must wear static electric hats, gloves, put on anti-static clothing and shoes, and meanwhile wear the static ring, thus the static can conduct from the human body to the earth, thus eliminating the human body static and also effectively inhibit the dust generated by the movement when personnel makes the operation.

 

 

"'For each daily matter, the working must be clean', it’s what every employee of Zhenduodian Technology has been doing to create a clean and tidy, bright and overall comfortable workshop environment. " stated by Gu, only production in such an environment, would reduce industrial injury accidents, and effectively prevent static electricity, thus to fundamentally improve the quality of operations.

 

3. In addition, a complete ESD working environment has certain requirements for the temperature and humidity, and generally, the humidity around 40% is the optimal.

Gu added that, air supply outlet on the wall is also set up in the workshop, and purification is often carried out in the dust-free workshop with the dirt catcher.

 

Summary:

In this issue, we’ve understood the importance of ESD operation area design in the production process of a qualified infrared screen in several aspects from the anti-static floor system, dust removal system, grounding system and the air temperature and humidity.

 

As Gu has always said, the establishment of ESD protection system is not the end, while it is just a start, what they need to do is often to detect the system, constantly discover imperfections and make the corresponding improvements.