Dangers of Static Electricity for PCB

Static electricity can be a serious risk to sensitive electric parts in many different industries and is particularly problematic when handling Printed Circuit Boards (PCBs). The damage caused by a small static discharge can permanently destroy the PCB and require costly repairs, downtime for your plant due to the loss of production, or even the complete failure of the equipment. If preventive actions are taken, the risk of static discharge to the PCBs can be reduced, helping to ensure the reliability and safety of the electronic devices you manufacture.

The Science Behind Static Electricity

To grasp electrostatic discharge in electronic devices, it is important to learn about how static electricity works. When two materials come together causing friction, they can become electrically charged and will have a lack of balance of charge due to this process. For example, if someone walks over a carpeted floor and comes in contact with an electronic device, the result can be an electrostatic discharge (ESD) of thousands of volts in only a few seconds.

In printed circuit boards (PCBs), static electricity poses a more serious risk than with any other type of electronic device. Because PCBs are comprised of tiny, complicated parts and undertake complex tasks when built up, static electricity can cause an electrical short (misconduct) in microchips, semiconductors and many other physical parts that are vulnerable within a PCB that, in turn, may ultimately result in failures of a PCB. Therefore, strict care should be taken during the production, testing, and assembly of PCBs for protection from static electricity.

Examples of Static Electricity Dangers

The following are examples of how static electricity can cause harm to PCBs through their use in everyday life by understanding how static electricity affects their circuits.

Two handling problems in manufacturing/inspection of PCBs can result in ESD damage resulting in product defects, thus producing low quality product due to damage to the PCB.

When assembly line equipment (conveyors, tools, etc.) are not properly grounded, they may produce static electricity which can cause damage to circuit boards prior to their installation.

Static electricity can develop as a result of improper packaging during shipping and delivery. If PCBs are not held in ESD-safe containers, they are at risk for static discharge.

Mishandled Storage: When circuit board assemblies (CBA) have no ESD protection, CBAs are more susceptible to accumulating harmful electrical charge when stored incorrectly or without protection.

The Human Element: Workers who do not wear gloves that are ESD safe can accidentally transfer electrostatic discharge (ESD) from their hands directly onto the printed circuit board (PCB) and cause degradation of the PCB’s function.

Is Static Electricity Bad for Electronics?

Yes, static electricity can damage electronics. Electronic circuits are inherently fragile, so a small discharge can cause major issues with total failure or decreased life expectancy. Additionally, ESD may not only cause the device to stop working altogether but may also cause an “invisible” defect that will cause the device to work intermittently and/or poorly.

As the trend towards utilizing smaller parts, and relying on more advanced technologies in manufacturing, has grown, the need to protect against electrostatic discharge (ESD) has also increased dramatically. In industries such as telecommunications aerospace automotive electronics and consumer electronics, providing protective measures for printed circuit boards (PCBs) from static electricity is essential rather than optional.

Are PCBs ESD Sensitive?

Definitely. PCB’s (Printed Circuit Board) are made of interrelated electronic parts (such as diodes transistors capacitors and resistors) and the corresponding electric field is very close to the PCB materials used to build PCBs. When an ESD (Electrostatic Discharge) occurs it may interfere with many of the sensitive electronic components used on a PCB, potentially causing some of them to immediately fail or create some other type of latent defect that will not be discovered until later. These latent defects may surface later on and be of significant concern to manufacturers and actually cause great distress to users.

To illustrate, high-speed digital designs usually have ultra-thin traces plus densely packed IC’s, which makes them very susceptible to static electricity. The risk of ESD increases because production volume rises as well as electronic design becoming more dense.

How to Protect PCB from ESD?

The bright side is that it’s manageable to protect your PCBs from ESD Damage as many manufacturers and users have appropriate preventative tools or techniques to help keep electronic devices and the parts inside them working correctly.

1. Use of ESD Trays for PCB

The ESD trays are intended to provide protection for the PCB from damage that could occur from transporting, storing and or handling PCB’s. The ESD tray will utilize either a conductive or dissipative material that will help absorb any static electricity. Using ESD trays will decrease the risk of an unintentional static discharge during production and distribution for manufacturers.

2. Store PCBs in ESD Bins

High-quality ESD bins for PCB must be used when circuit boards are not being used. The bins are essential for an uninterrupted manufacturing process with large numbers of components able to be safely stored in an ESD controlled environment.

3. Cleaning with ESD Brushes

For optimal performance of a printed circuit board (PCB), regular maintenance must be conducted using your everyday cleaning tools. An electrostatic discharge (ESD) brush is preferable due to its ability to not produce static build-up during the cleaning process as well as effectively removing contaminating materials. A non-ESD brush will usually produce some amount of electrical discharge, increasing the chance that you could cause damage to the circuit board because of it.

4. Safeguard Transportation with ESD Boxes

Electrical ESD packing boxes for Electrostatic Discharge are used during transport and handling of PCBs. ESD boxes are strong boxes that prevent static buildup and provide protection from dangers due to electrostatic field discharges (EFD). The sensitive electrical components contained in these boxes are kept from accidental contact with static electricity.

5. Maintain ESD-Safe Workspaces

PCBs are at risk from static electricity, and therefore, anti-static mats, wrist straps and grounding systems must be considered essential protection methods. Using these tools will help to mitigate the chances of unintentional ESD discharge and create a safer workplace for employees and their environments. ESD-safe conveyors for sensitive PCB assemblies also provide an invaluable means of transferring PCBs between production lines while eliminating static damage.

Best Practices for ESD Management in PCB Processes

To create an Electrostatic Discharge (ESD) safe work environment there are multiple elements that need to be considered. Below are some basic best practices that will provide the most protection for your PCB’s.

Training your employees on how to properly and safely handle sensitive electronic components will help keep your entire organization protected against Electrostatic Discharge (ESD).

Continuous Audits: Ensure compliance with ESD control measures as required by the industry and conduct regular audits accordingly.

ESD Supplies: There are various ESD products (trays, bins, brushes, boxes, etc.) that should be used frequently in both products made, to produce and perform maintenance.

Humidity levels on production floors should remain at optimal levels. Excessively dry conditions create the potential for the formation of static electricity.

Testing Practices: Conduct routine testing of sensitive components to identify and resolve potential ESD-related failure points.

The Costs of Ignoring Static Electricity Risks

The failure of implementing ESD protection methods can cause negative monetary impacts for all involved; the business which produces or sells the ESD-sensitive product and the end-user who receives such a product. They may incur high costs to replace or repair damaged products, suffer from less reliable product output, and incur damage to their reputation. In industries with significant output levels of products that must work reliably, there is more significant long-term impact if there is a total or partial ESD failure, such as loss of customers or loss of market share.

Building a Proactive ESD Strategy

An ESD-safe Work Environment and utilizing ESD tools are the best ways to combat static electricity proactively. Using high-quality ESD trays for PCB’s is a great investment in your PCB protection program. Also, creating ESD training programs, performing regular inspections, and implementing ESD-safe conveyors or workspaces in your manufacturing setup creates measurable benefits, such as fewer product failures and greater product reliability.

When companies wish to remain competitive they must also consider ESD issues as part of their successful business strategy. The implementation of ESD safety measures can greatly reduce risk, offer greater protection for investments, and provide quality products to the end user if considered in a holistic manner.

Staying ahead in electronics manufacturing is based on innovation, a strong foundation of quality control and how to protect yourself from risks such as static electricity.

In conclusion, protecting printed circuit boards (PCBs) against static electricity requires consistent diligence and appropriate investment into static electricity safe tools such as ESD trays, ESD bins, ESD boxes, ESD brushes and ESD conveyors. Manufacturers, distributors and service technicians should continually assess the need to protect their products from potential damage due to static electricity by prioritizing static electricity protection so that they can maintain the reliability of their products throughout their life. By implementing the procedures suggested in this article you will reduce risks and contribute to a more efficient method of handling PCBs in any environment.