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Static electricity is the imbalance of electrical charges which is generated when two materials are brought together and then separated. These imbalances of electrical charges are caused by electrons being stripped off the other material, causing the material that loses electrons becomes positively charged and the material that gains electrons becomes negatively charged. The process of where static electricity is generated is called Triboelectrification.
The polarity of charge on a material depends on the material type and its position in the Triboelectric Series.
When two materials are rubbed or come into contact and are separated, the material in the upper position in the Tribolelectric Series will become positively charged and that in the lower position in the Triboelectric Series becomes negatively charged.
The amount of static charges generated depends on several factors such as:
• Speed of motion
• Pressure applied from the motion
• Relative humidity of the ambient
• Surface area and surface roughness
Understanding static electricity and Electrostatic Discharge (ESD) is vital in combating the nuisance it caused in our daily lives whether at home, outside home or in our working areas. Static electricity and ESD pose greater danger particularly in working areas that deal with microelectronic devices which are sensitive towards ESD damage.
Common ESD experiences include static shock when touching the metal door knob, kid’s hair standing while passing through the slide in the playground and fire occurence at the gas pump station. Contrary to those ESD experiences encountered both at home and outside home, the ESD experience in the working area is totally different. Some ESD experiences in the working area may include high failure during final testing, low process yield or unexplained product return from customers.
All the ESD experiences happen are either due to accumulation of static electricity or the rapid discharge of the accumulated static electricity from the object of high electric potential to another object of lower electric potential. The discharge of static electricity between the two objects of different electric potential is called Electrostatic Discharge (ESD).
While we start to feel the presence of static electricity with at least 3000 volts, some electronic device such as Tunneling magneto –resistor (TMR) heads are susceptible to esd damage with a less than 10 volts Human Body Model (HBM) of static electricity.
The launch of ESD on campus program by ESD Association (ESDA) somewhere in Sept 2006 has caused ESD subject to gain more attention from universities around the globe. The ESD on campus program helps to produce graduates with ESD knowledge who are needed to support the growing number of electronics companies whether in semiconductor, disk drive or printed circuit assembly, around the world especially in the Far East region.
With that, it is explained why understanding Static Electricity and ESD is important in our daily lives.
