BenchMaster have manufactured ESD top workbenches for over 10 years. Over this period of time BenchMaster have sought and continue to enhance the specification resulting in fully ESD functioning workbenches and meeting specification EN61340-5-1.
Why are ESD workbenches necessary?
The manufacturing process of circuit boards, micro chips and other sensitive electronic equipment can be negatively affected should electro static discharges occur. A relatively inexpensive microchip maybe part of a much more expensive piece of equipment and should the more expensive piece of equipment fail it has a high correction cost never minding loss of reputation etc. Electro static discharges can be eliminated with the BenchMaster ESD functioning workbench and associated equipment.
Be aware the initials ESD are also short for electro static discharge which can easily be confused with what BenchMaster offer which is an Electro Static Dissipative functioning workbench. It is the term dissipative (gradual dissipation of electro static) that is the most important aspect of a BenchMaster ESD functioning workbench.
How is electro static discharge overcome with the Benchmaster ESD functioning workbench?
The simple answer is that BenchMaster manufacture the workbench with electro static dissipative materials so it is ‘set up’ for immediate use once plugged into a standard earthed UK wall socket. If a number of workbenches are ordered it is possible to ‘link’ the earthing system but please check best solution with Benchmaster.
Dissipative properties allow a gradual discharge of static so it is unlikely to cause damage to electrical circuits whereas an immediate discharge significantly increases the risk of damage to circuits.
Key points of the BenchMaster ESD ready workbench specification
The frame is powder coated architectural black that offers a 10⁶ dissipative resistance and supported with suppliers’ certificate of conformity.
ESD laminate work surfaces supplied and tested in accordance with EN61340-5-1 and supported with suppliers’ certificate of conformity. Volume resistance RD 1 x 10⁴ – 1 x 10⁹ Ohm (EN 61340-5-1) measured dry with measurement voltage 100 V DC and cylindrical electrode 20-30°C and 20-50% relative humidity.
1200mm long x 600mm deep dissipative rubber mat earthed via 1 Mohm resistor and cable.
An earth bonding point with 3 studs each with 1 Mohm resistors attached to front left-hand frame under worktop plus earth cable and plug for use in standard UK earthed wall socket.
Adjustable wrist strap with 1 Mohm resistor and earth cable.
Whilst BenchMaster have supplier certification they test every ESD laminate work surface with a Megohmmeter to ensure all their worktop has correct dissipative properties in accordance with EN61340-5-1. All worktops are marked with a ‘proof of test’.
Declaration of Incorporation certificate to EN61340-5-1.
Bespoke solutions beyond the above specification-customers should advise what they require and BenchMaster usually have a solution.
What is static electricity?
As the name suggests static electricity is electricity at rest however some materials and humans cause electrons to become charged and so seeking routes to earth in what is described as an electro static discharge.
Electro static discharge has been around since the beginning of time- there can be few of us who have not experienced a static shock or the effects of tribocharging. Examples are getting out of a car, combing your dry hair with a plastic comb, rubbing a balloon against woollen clothes and/or removing clothing. It is like a tiny version of lightning and has become an issue with the development of solid-state electronics.
- 1) Electrostatic discharge occurs in a variety of forms:
- 2) Trouble shooting electronic equipment or human handling of printed circuit boards without using an electrostatic wrist strap.
- 3) Placement of synthetic materials (plastics, Styrofoam etc) on or near electronic equipment.
- 4) Rapid movement of air near electronic equipment such as compressed air to try and clean dirt off circuit boards.
While humans can feel some of these effects of static electricity it 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.
Humans are great generators of electrostatic charge and voltage, as we find with the common experience of electrostatic shocks. To feel a static shock, most people need at least about 3000-4000V on their body however it may only take 100V, or even less, to damage an electronic component. So if two objects that have different voltages approach each other closely enough or touch a charge is likely to pass from one object to the other in a rapid electro static 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 kilo watt range!
The heat from an electro static discharge event is extremely hot and whilst humans do not feel the heat when they feel a static shock; this same charge when released into an electronic device such as an expansion card can melt or vaporise small parts causing failure in the card. Many electronic devices are susceptible to low voltage electro static discharge events such as a hard drive that can be sensitive to as little as 10 volts.
An electro static discharge event can cause unseen damage to electronic components during manufacture. If the damaged component fails immediately, the result can be a circuit board that fail tests and requires rework which represents lost production and additional manufacturing costs. Worse than this is if a component becomes partially damaged and weakened so may remain within specification but has a change in characteristics and later fails when in use by the customer. This is a much more expensive type of failure.
Other terms used in connection with electro static.
Electro static discharge of electricity happens between two electrically charged objects with different electrical charges. This is caused by actual or close contact or a dielectric breakdown.
Anti-static is where the build up of static is prevented by ensuring an item is not insulted so can conduct electricity.
Dissipative is where electrical charges are allowed to slowly and in a controlled manner find their way to earth. This is what BenchMaster offer with their fully ESD functional workbenches.
Conductive is where electrical charges pass easily over or through materials.
Insulative materials prevent or limit the flow of electrical charges over or through materials so are difficult to earth.
Other useful information re on site usage of ESD workbenches but note it is the end user’s responsibility to ensure correct usage.
1. Ensure all operatives working in an ESD designated area are suitably trained and aware of ESD required standards.
2. Always wear a wrist strap and/or other personal grounding devices when working in an ESD designated area.
3. Avoid damaging ESD laminate worktops and paints with sharp objects as this can lead to loss of ESD protection.
4. Keep non-conductors and unnecessary materials away from an ESD designated areas.
5. All sensitive components must only be handled and/or transported in an ESD safe environment.