The electrostatic discharge safe environment at Hallmark Nameplate is designed to prevent electrical discharges from the body or from devices, both of which could impact the delicate electronic components we value so highly. Our ESD-Safe production environment ensures that components of your product remain safe through the assembly process and through packing for shipment to you.
It is true that electrostatic discharge has existed since the beginning of time. However, this natural phenomenon has grown into more and more of an issue with the widespread use of solid-state electronics.
Where does Electrostatic Discharge come from?
All materials, insulators and conductors alike, are sources of electrostatic discharge. They are lumped together in what is known as the “triboelectric series,” which defines the materials associated with positive or negative charges. Positive charges accumulate predominantly on human skin and animal fur, while negative charges are more common to synthetic materials, such as Styrofoam or plastic. The amount of electrostatic charge that can accumulate on any item is dependent on its capacity to store a charge.
How does Electrostatic Discharge damage electronic circuitry?
ESD is like a tiny version of lightening. As the current dissipates through an object, it’s seeking a low impedance path to ground to equalize potentials. In most cases, ESD currents will travel to the ground to via the metal chassis of a device. However, it’s well known that current will travel on every available path within reach. In some cases, one path may be between the PN junctions on integrated circuits to reach ground. This current flow will burn holes visible to the naked eye in an integrated circuit, with evidence of heat damage to the surrounding area. One ESD event will not disrupt equipment operation, however, repeated events will degrade equipment’s internal components over time.
How does Electrostatic Discharge occur?
ESD can occur in a variety of forms. One of the most common is through human contact with sensitive devices. Human touch is only sensitive on ESD levels that exceed 4,000V.
A recent investigation found that the human body and its clothing capable of storing between 500V and 2500V electrostatic during the normal workday. This is far above the level that damages circuits yet below the human perception threshold. Other sources of ESD damage to equipment include:
- Troubleshooting electronic equipment or handling of printed circuit boards without using an electrostatic wrist strap;
- Placement of synthetic materials (plastic, Styrofoam, etc.) on or near electronic equipment; and
- Rapid movement of air near electronic equipment (including using compressed air to blow dirt off printed circuit boards, circulating fans blowing on electronic equipment, or using an electronic device close to an air handling system).
In all of these scenarios, the accumulation of static charges may occur, but you may never know. Furthermore, a charged object does not necessarily have to contact the item for an ESD event to occur.
How is electrostatic voltage measured?
One of the most effective ways to identify potential ESD problem areas is to make measurements using an electrostatic voltmeter. This meter will effectively measure electrostatic voltage up to 30,000V on all conductors and insulators. It also will display whether the charge is negative or positive. This may help you determine the source of the electrostatic accumulation.
How is Electrostatic Discharge prevented?
Experience has shown that the following guidelines are helpful:
- Keep all synthetic materials at least four inches away from electronic equipment.
- When cleaning printed circuit boards, use a spray labeled as non-static forming.
- When troubleshooting electronic equipment, always wear a static wrist wrap that is grounded to the frame of the device. Also, wear the wrist strap when handling printed circuit boards.
- Treat carpets and floors with compounds that reduce the buildup of static charges.
- Use static floor mats where necessary.
- Make sure the grounding system for equipment has a low impedance for ESD currents to dissipate to an earthing reference.
Hallmark Nameplate does what it must do to maintain a safe environment for not just our employees, but also for the products we create and send to our clients. When you choose a company for your electronic assemblies, your first concerns should be quality, safety, and reliability. Hallmark Nameplate is passionate about all of these things, and design products with longevity and safety in mind. If you’re ready to start your next product with a leading industry group of experts, contact us at Hallmark Nameplate for more information about our electronic assemblies.