Understanding Static electricity and Electrostatic Discharge (ESD)

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.

ESD Control Program plan

The main element in any ESD Control Program is the ESD Control Program plan itself.
What is an ESD Control Program plan? An ESD Control Program plan is basically a procedure that is written in a manner where it normally covers all the activities that involve in controlling the generation of static electricity and its electrostatic discharge.
The ESD Control plan does not have to be as thick as your Harry Porter story book as someone may think of. It usually covers a few tenths of pages.

Many electronic companies already have their own documentation system in place either their documents are stored online using a specific documentation system software or their documents are stored in hardcopy forms.

In both formats, the ESD control program plan should be written in a systematic approach. A systematic ESD Control Program plan or procedure should cover the following:

•Purpose :
•Scope :
•Organizational responsibilities :
•Activities and tasks :
•List of supportive documents used in the program :

The ESD Control Program plan should address each of the following requirements in the main body of the plan.

•Training plan
•Compliance Verification plan
•Grounding/ Equipotential Bonding system
•Personnel Grounding
•Packaging System
•ESD Protected area requirements
•Marking
•Equipments
•Handling

Full guidance on preparing the ESD Control Program plan can be obtained from
ANSI/ESD S20.20 standard. Other supportive documents that would help in preparing the ESD Control program plan include:

•ANSI/ESD S6.1 , Grounding
•ANSI/ESD STM97.1 , Floor materials and footwear – resistance measurement in combination with a person
•ANSI/ESD STM97.2 , Floor materials and footwear – voltage measurement in combination with a person
•ANSI/ESD S1.1 , Wrist straps
•ANSI/ESD S4.1 , Work surface – resistance measurements
•ANSI/ESD S7.1 , Floor materials – characterization of materials
•ANSI/ESD S541 , Packaging materials for ESD sensitive items
•ANSI/ESD STM2.1 , Garments
•ANSI/ESD STM3.1 , Ionization
•ANSI/ESD STM12.1 , Seating
•ANSI/ESD TR53 , Compliance verification of ESD protective equipment and materials
•ANSI/ESD STM13.1 , Electrical soldering/desoldering hand tools
•ANSI/ESD SP10.1 , Automated handling equipment

The ESD Control program plan or procedure should be prepared in a manner that it integrates and conforms to internal quality system requirements.

The ESD Control program plan is an important document for verifying the effectiveness of the ESD Control program in the organizations.

An example of ESD Control Program plan can be obtained here.

Running an ESD Control program

Most organizations across the globe already have some ESD controls in place.
If your company hired and assigned you as an ESD Coordinator to improve the existing ESD controls, then below are the few tips that are worth to consider helping you in your journey to setup and run a manageable ESD Control program.

• Support from Top Management: Support from Top Management is essential for running a successful ESD Control program. Support in terms of training provision for ESD Coordinator, ESD material and products provisions, following the ESD control rules in the organization are the few kind of support that the Top Management can do.
• Forming a team: Forming a team or an ESD Steering Committee which has members from different disciplines/departments such as Maintenance, Engineering, Quality, Purchasing, Production and Training is much encouraged. With the existence of members from different disciplines and departments, workload can be shared and ESD controls can be implemented without many obstacles.
• Periodic communication: From time to time, communication on ESD controls should be imparted through the organization communication channels. This is aimed to send a gentle reminder to the employees about the ESD rules that they tend to forget.
• Periodic inspection: From time to time, periodic inspection or audit on the ESD compliance in the organization should be carried out in a systematic manner to ensure continuous ESD protection.
• Integration with ISO 9000 requirements: The ESD Control program should be implemented and integrated with the ISO 9000 requirements. For example: ESD audit should be planned in an audit schedule and ESD materials should be evaluated and reevaluated.
• Continual improvements: Continual or gradual improvement is recommended to be taken either upon receiving customer feedback, audit findings or through technology changes.
• Continuous training provision: Continuous training provision to the employees of all levels is essential to ensure the ESD Control program is running as it is intended.
• Decision based on facts: To ensure the ESD Control program is cost effective and running effectively, any decision made has to be based on facts to prevent overspending.

ANSI/ESD S20.20 Registration

Organizations that already have their ESD Control Program setup based on ANSI/ESD S20.20 can prepare their plants to be certified by a 3rd party certification body such as DNV, BSI or QMI to name the few.

A list of 3rd party registrars or certification bodies is available in the ESDA website.

Certification against ANSI/ESD S20.20 helps to assure both the organizations and their customers that the products they are manufacturing or received by their customers meet the minimum requirements set by the ESD standard.

This also assures their products are continuously protected from ESD damage.

ESD Control Program Setup

Electrostatic Discharge Association (ESDA) developed and published ANSI/ESD S20.20 Standard for public use in 1999.

Since then, many organizations have referred to this Standard as a reference when establishing the ESD Control program.

ANSI/ESD S20.20 Standard guides an organization on how to setup the company ESD Control Program through its systematic approach detailing the ESD control requirements that are to be implemented and controlled in the organization.

The ANSI/ESD S20.20 Standard can be free downloaded from
the ESDA website.

What is an ESD Control Program?

An ESD Control Program is a plan or a system that administers the controls on electrostatic discharge.

It is aimed to provide continuous ESD protection for the ESD items that are manufactured by the organizations.