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Why Static Electricity Matters When it Comes to Working Inside Computers
Much as static electricity gets quite a mention across online forums, it continues to receive lackluster and divided attention in many computer repair shops and homes. We treat it cursorily arguing/hiding in the excuse that electrostatic discharge (ESD) related failures never happen, by citing fault-free years of fiddling inside computers with success!
This is wrong. Whereas the degree of ESD damage will depend on a number of factors, climate included, its effects on computer assembly should not be ignored.
To illustrate the importance Silicon Valley attaches to static electricity, personnel working in close contact with sensitive integrated circuitry have to discharge all kinds of static build up in dedicated containment. Only then can they touch electronic parts in the assembly rooms.
- Electrostatic Discharge and Electrical Overstress Guide
Guide: Overview of electrostatic discharge (ESD) and electrical overstress (EOS) with preventative measures and strategies for eliminating damage.
And yes, ESD effects may not manifest themselves immediately most of the time. A component that survives ESD exposure the first time may still escape even after two or more exposures.
However, latent damage to integrated circuits and other printed circuit board (PCB) traces and junctions may happen and go unnoticed for days or months.
The constant data related errors and computer breakdown largely unknown to the tech guys but the user should be the tell-tell sign.
Assuming we do not follow up on the behavior of every computer we handle - which is true most of the time, except in enterprise setups, - we probably never get to know about these hiccups.
And this will leave us with false diagnosis when the computer in question is shipped back days or months later with different problems! In a typical diagnosis stereotype, something else will have caused memory and other errors. The blame will fall squarely on incompatible hardware, shipping slip-ups, driver issues or factory defect!
As much as the above diagnosis could be true, defective PCB arising from previous exposure could be reason enough.
How often do you blame computer failure on electrostatic discharge?
Understanding the Buildup of Static Electricity
We generate electrostatic charge when we walk or rub on synthetic material and other insulating objects. The constant movement of shoes on carpets facilitate the transfer of mainly electrons to the body, creating an imbalance of positive and negative charges.
The human skin allows for free flow of electrical charge because it is a conductor object. In a situation where the body is electrically isolated from the earth or other conductive objects, say synthetic carpet or shoe soles, it will accumulate vast amounts of charge, with every additional friction as we walk along. The body becomes a capacitor of sorts because it accumulates more of this energy along the way.
Static electricity is basically a state of imbalance of positive (proton) and negative (electron) charges on an object. This object can be anything human or other material like a hat or a cup.
As noted above, the imbalance is caused when the charges move from one object to another because of physical contact.
Any accumulated charge in excess of 3,000 will lead to a spark when the human body touches a grounded object. The discharge from the body to the next conductive object will lead to the balancing of negative and positive charges, amidst the apparent electrostatic shock.
The human body is actually capable of absorbing and subsequently discharging anything up to 20,000 volts, which is more than enough to zap a circuit board at point of contact.
We need to note that any charge in excess of 50 volts can also initiate latent damage to a printed circuit board!
The Role of Conductors and Insulators
It is important to know the kind of objects in and around the workplace, in relationship to the human body, which can trigger the buildup of static electricity. Maybe that way we can start implementing precautionary measures.
There is no better way to do this than to understand the role of conductors and insulators.
Conductors are materials that allow free flow of electrical charge.
The human body is a conductor of electricity and therefore capable of allowing free movement of electrostatic charge within it.
Like other conductors, it can accumulate vast voltages of electrostatic charge, especially when blocked from dissipating the same due to insulator obstruction i.e. when enclosed within insulating objects like shoes, clothes and surfaces.
This charge will, however, flow freely to another conductor when the body interfaces with it directly, say a printed board circuit.
In addition to the human body, below are some popular conductors through which electricity can flow freely:
- Dirty water
- Humid air
- Human body
Insulators are materials that do not allow free flow of electricity.
Unlike the conductive human body, insulators prefer to hold on tightly to electrons within them but will lose a few when rubbed upon by other objects, say when shoes repeatedly rub on a carpet.
The more the human body walks and rubs against insulators, the bigger the friction, and the more likely the ‘few’ charges will jump ship from the insulating carpet and shoes to the conducting body or vice versa.
Popular insulating materials include:
- Pure water
- Dry cotton
- Dry paper
- Dry wood
- Dry air
How You Can Prevent Electrostatic Charge from Zapping Printed Circuit Boards
Now that you know how different materials react in order to generate electrostatic charge, it is time to figure out how to dissipate these charges correctly without causing damage to memory chips, disk drives, motherboards and other printed circuit boards in the workshop.
Remember that most tips to help discharge electric buildup revolve around grounding the human body or related objects. Grounding helps neutralize the negative and positive charges.
As a rule of thumb, you should never touch the innards of the computer before grounding yourself.
This can be done by using resources available around us or with the aid of recommended antistatic contraptions. A lot of antistatic tools are available online and in local stores around the world.
Each of the tips illustrated below should work in tandem with the others to provide the best possible results. But again, anyone of them is better than nothing when it is the only option.
• Use Localised Grounding at Home
If you are unable to reach for standard grounding contraptions, you may want to use the only grounding resource available in the workshop – your body and the earth.
To do this, touch the metallic frame on the casing of the computer (the unpainted parts) whose three prong power cable is connected to an earthed power outlet. Make sure the electricity source is turned off at the mains.
Then you can use the other hand to remove and install components inside your desktop computer.
As for laptop computer or other mobile devices, make sure to neutralize the positive and negative charges in your body elsewhere before taking it apart.
Of course, you are better off using antistatic gear explained below for better protection of your laptop.
Do you ever feel guilty touching the innards of a computer, wondering if you may fry someting?
• Use Anti-Static Gear for the Body
You are much safer using one of the anti-static gear listed below when probing inside the computer.
You can choose from one of these contraptions which you attach directly to your body and grounded outlet:
- antistatic wrist wrap
- antistatic finger cots
- antistatic belt
- antistatic heel straps
- antistatic shoes
- antistatic smock
• Ground the Workshop Table and Floor
To complete the above set of antistatic body gear, you may want to set up a workshop floor and table which are static safe.
Go for antistatic mat or tiles and this way you may have the fun of going around barefoot!
If a plain floor is what you have in mind, then install wooden tiles without painting, but if painting is a must, then go for Total ground conductive paint.
And just in case you cannot do away with that pricey carpet, you may want to rethink purchasing an antistatic mat.
For the workshop table, the first option is usually the antistatic table mat which should be more than enough to hold electronic components.
If, however, a plain table is all you can afford, install a wooden one. Beware though that careless placement of materials on its top may help generate unwanted static charge. But again it is better than plastic, vinyl and fiber glass tops.
In the same vein, do not use conductive stainless steel as a working surface. Steel as a surface emits low electrical resistance which may permit rather fast and transient-like discharge of static electricity.
• If Necessary, Humidify the Air
Humidity is the moisture content found in the air. Humidity can be helpful in neutralizing the charge buildup in floors, carpets, plastics and other insulating objects, through the conductive air.
Likewise, unwanted charges on the body will also dissipate most of the time into humid air if it is dense enough.
The higher the humidity density in the air, the less the effects of static electricity.
The state of weather in different countries determine the density of humidly in the air. For example, Summer, unlike Winter will ensure denser humidity, and geographical areas near the Equator, Northern Asia and the Americas tend to have higher humidity density than the cold and dry geographical locations.
If you live in geographical locations with less humidity, consider available options to help pacify the air.
- Use humidifier products
- Plant crops around the house or workshop
- Boil water (just joking, but actually works)
• Use Appropriate Clothing
While clothes hide nakedness and give us warmth, some actually exacerbate levels of electrostatic charge. Because of the constant friction against the body, synthetic clothes will transfer and facilitate the buildup of electrostatic charge onto the human body.
This buildup will be transferred to printed circuit boards when we touch them using our naked hands.
Top of the list of synthetic clothes are nylons and a variety of smocks.
To reduce instances of ESD buildup in your body, always wear cotton based clothes.
• Use Static Protective Packaging
Not every packaging is suitable for storage of electronic components.
Generic plastic bags should not be used to carry RAM, disk drives and other electronic parts.
Whenever storing or transporting computer components, ensure they are wrapped securely in antistatic packaging.
• Ground Workshop Tools
Finally, time to consider the tools we use to fix the computer: assembly and disassembly mainly. Handy tools like screwdrivers, screws, tweezers, plastic containers, brushes, soldering heat guns, air blowers etc are a collection of conductors and insulators.
Unfortunately, they are always shoveled together regardless. This kind of set up will make the different parts generate abundance of negative or positive charges.
To prevent ESD damage try to store them safely and dissipate electrostatic charges in them whenever using them.
Beware of air blowers which are capable of generating static charge during the process of blowing dirt out of the computer.