By Dr Jeremy Smallwood, Electrostatic Solutions Ltd. How to use The ESD Guide. The ESD Guide gives an introduction to the main requirements of the EN 61340-5-1 Electrostatics. Protection of electronic devices from electrostatic phenomena – General Requirements and it’s User Guide EN 61340-5-2. We’ve also included some.

A Guide to ESD

Actian Electronic Software Distribution This site allows you to download enterprise software, patches, documentation, database drivers, patches, and enterprise evaluation editions. Enterprise editions are subject to your signed software license agreement from Actian or (if none) the license included with the product. The Electronic System Design Alliance (ESD Alliance), a SEMI Technology Community, an international association of companies providing goods and services throughout the semiconductor design ecosystem, is a forum to address technical, marketing, economic and legislative issues affecting the entire industry. This minimum design value, as measured by a MM tester, is well above any voltage remaining on all properly grounded machines in an ESD protected manufacturing environment. In essence, meeting a safe value for HBM (and CDM) is sufficient for production of ICs without needing to evaluate MM as an additional qualification. Actian Electronic Software Distribution This site allows you to download enterprise software, patches, documentation, database drivers, patches, and enterprise evaluation editions. Enterprise editions are subject to your signed software license agreement from Actian or (if none) the license included with the product.

By Dr Jeremy Smallwood, Electrostatic Solutions Ltd

How to use The ESD Guide

The ESD Guide gives an introduction to the main requirements of the EN 61340-5-1 Electrostatics. Protection of electronic devices from electrostatic phenomena – General Requirements and it’s User Guide EN 61340-5-2. We’ve also included some background information as to the principles behind these standards.

These documents are now standards in Europe and have replaced EN100015. They are available in the UK as BS EN 61340-5-1:2001 and BS EN 61340-5-2:2001. (See 'Where to get' at the end of this article). These two BS ENs are technically identical to the original IEC documents. IEC 61340-5-1 & 2 are expected to remain in their current form until 2005.

Whilst The ESD Guide gives many of the key requirements and recommendations, it is not comprehensive and we recommend that you obtain copies of the 61340-5-1 & -2 documents for full guidance.

Esd Electronic System Design Driver Handbook

What is ESD?

ESD stands for ElectroStatic Discharge.

Static electricity is an everyday phenomenon - there can be few of us who have not experienced a static shock after walking across a room and touching the door knob, or on getting out of a car.

Other static nuisance effects include the cling of some fabrics to the body, the sticking of a plastic document cover, or the attraction of dust to a TV or computer screen.

While we can feel some of these effects, static electricity is normally present at lower levels that we cannot feel, hear or see, but may nevertheless damage sensitive electronic components. It can build up rapidly on objects, in unexpected ways, to produce surprisingly high voltages.

If two objects that have different voltages approach each other closely enough, charge may pass from one object to the other in a fast electrostatic discharge. While this only lasts a microsecond or less, the peak discharge current can be several Amps and the peak power can be in the kiloWatt range!

Why worry about ESD?

ESD can cause unseen damage to electronic components during manufacture of electronic assemblies and equipment. If the damaged component fails immediately, the result can be a board that fail tests and requires rework. This represents lost production and additional manufacturing costs.

Worse than this, a component may be partially damaged and weakened. It may suffer a change or drift in characteristics. It may remain within specification, but fail later when in use by a customer. It has been estimated that 90% of damaged devices may be discovered in this way. This is the most expensive type of failure, as it represents:

q Customer dissatisfaction, and the possibility of loss of product reputation and future sales

q Customer service personnel and facility cost

q Engineers time, possibly for on-site repair with travel, and parts replacement

Analysis of non-conforming or defective devices showed that 60-75% were damaged by EOS (electrical overstress) or ESD. This rises to 90% for newer technologies. About 70% of these failures were attributed to damage from incorrectly grounded people.

Toshikazu Namaguchi, Hideka Uchida.

EOS/ESD Symposium EOS-20 1998 pp 245-251

In manual assembly most ESD arises from charged personnel, if they are not grounded.

Most people do not feel an ESD shock unless they are charged to over 4000 V (the sensitivity threshold varies between people, and even over parts of the body!). This voltage is quite common in the uncontrolled environment - how many of us have not felt the occasional electrostatic shock in everyday life?

Overview of 61340-5-1 & 2

The IEC 61340-5-1 Technical Report Protection of electronic devices from electrostatic phenomena – General Requirements was developed from earlier Standards including EN100015. It is accompanied by a User Guide IEC61340-5-2, which gives a lot of additional information to help the non-specialist implement IEC61340-5-1. As a IEC documents, they have world-wide applicability and are planned to be developed into full world-wide IEC standards in the future.

In Europe, the 61340-5-1&2 documents have been adopted by CENELEC to replace EN100015. We recommend that the guidance given by the 61340-5-1 General Requirements document is considered mandatory, while the additional guidance given by the 61340-5-2 User Guide may be considered to be recommendations.

Parts of 61340-5-1 may be found on technical grounds to be unnecessary or irrelevant to a particular installation or processes, and may be omitted. Where only partial compliance is required in this way, this should be made clear to all who use or audit your ESD facilities. A good way to achieve this would be to document it in an in-house ESD Programme or the EPA Certificate of Conformance.

IEC61340-5-1 specifies general requirements for the design, use and control of a protected area so that electrostatic sensitive devices (ESDS), having sensitivity of 100V (Human Body Model test) or higher, can be handled with minimal risk of damage from procurement through to end of life. The Technical Report covers:

q Signs and markings

q The electrostatic protected area (EPA) including requirements for protective equipment, construction of the EPA, working practices, and field work

q Protective packaging

q Training requirements

q Quality responsibilities

q Periodic Audit instructions

An Annex describes test methods to be used to verify the performance of equipment, materials and packaging for use in protection of ESDS.

The Technical Report does not cover health and safety requirements, and compliance with local regulations and practices should always be observed in this respect.

The Technical Report warns that special care may be required in implementing static damage prevention measures under the following conditions:

q Low humidity. The electrostatic properties of materials are very dependent on atmospheric humidity. A controlled humidity of 50 %rh suits most circumstances. If humidity reduces below 20 %rh, ensure that selected materials and equipment will perform effectively under operational conditions.

q Clean room conditions. Some current materials and techniques in use for ESD protection are not suitable for use in clean rooms (class 100 or tighter).

q Where high voltages may be present. If high voltages greater than 250VAC or 500VDC are present then take particular care to consider safety requirements.

Definitions

Key elements in an ESD Program

Principles of electros