SCS is excited to announce a brand new video series discussing real-life ESD problems and solutions.  This is a great educational resource for anybody new to ESD or just wanting to learn more about best practices.

Each episode will focus on one issue commonly found in an ESD Protected Area – at the same time we will present solutions so you know how to tackle the problem should you ever face it in your own factory.

A new episode will be published each week so make sure you subscribe to our YouTube channel to get notified when a new video is available. Episodes 1 and 2 are now live so don’t waste a second longer and catch-up now:

Welcome back to “A Minute with Miranda.” This week we will be covering how to properly wear a wrist strap.

ANSI/ESD S20.20 requires seated personnel to be connected to the grounding / equipotential bonding system via a wrist strap. The total resistance of the Wrist Strap System needs to be less than 3.5 x 10^7 ohms. The key to a wrist strap is the intimate contact of the band to the skin and that the coil cord is connected to ground. Wrist straps need to be tested at least daily before handling any ESD sensitive devices.

Operators can choose between elastic and metal wristbands. Elastic wristbands are comfortable to wear and easy to adjust. Metal wristbands generally last longer and are easier to clean. View the full range of SCS Wrist Straps here.

Welcome back to “A Minute with Miranda.” This week we will be covering how to perform the Rtt and Rtg test on an ESD Worksurface Mat.

Before using a worksurface mat in an EPA environment, you need to verify that the mat will meet the ANSI/ESD S20.20 Worksurface Requirements.
For both the Rtt and Rtg test the worksurface should test between 1 x 106 to less than 1 x 109 ohms. The test should be performed in accordance to the ANSI/ESD S4.1 Standards.

SCS worksurface mats meet the ANSI/ESD STM4.1 and ANSI/ESD S20.20 required limit of 1 x 10^6 to less than 1 x 10^9 ohms for Rtt and Rtg and the recommendations of ANSI/ESD S4.1.

View our complete SCS Static Worksurface mat offering here.

Welcome back to “A Minute with Miranda.” This week we will be covering how to launder your ESD Smocks.

SCS Static Control Smocks should be laundered periodically for proper operation. Smocks should be washed by hand or with a standard household washing machine using cold or warm water with a non-ionic liquid detergent. Avoid using bleach, fabric softeners or dry detergents as these can contaminate the conductive fibers and make the garment insulative .

After washing the smocks they should either be hung dry or tumbled dry at low heat. High heat can degrade the conductive fibers within the garment and degrade the ESD properties.

With normal wearing and washing conditions, SCS Static Control Smocks will maintain their ESD properties for a minimum of 100 washings.

SCS Smocks meet the requirement for Groundable Static Control Garment System per ANSI/ESD S20.20 required limit of less than 3.5 x 107 ohm Rtg tested per ANSI/ESD STM2.1 and ESD TR53.

To learn more about SCS Smocks, click here.

Welcome back to “A Minute with Miranda.” This week we will be covering ESD Worksurface Mats.

SCS worksurface mats serve two purposes for an ESD worksurface in an EPA:

  • they provide a surface that does not generate a static charge and
  • they remove charges from all charged conductors, which include ESD susceptible devices and assemblies, that are placed on the surface.

SCS worksurface mats are constructed from either dissipative 2 layer rubber or 3 layer vinyl material and are available in both rolls and mat kits.

We can also quote custom sizes SCS worksurface mats meet ANSI/ESD STM4.1 ANSI/ESD S20.20 required limit of 1 x 106 to less than 1 x 109 ohms for Rtt and Rtg and the recommendations of ANSI/ESD S4.1

For more information on SCS Worksurface matting, check out our Selection Guide here.

The best way to keep electrostatic sensitive devices (ESDs) from damage is to ground all conductive objects and remove insulators from your ESD Protected Area (EPA). This is not always possible because some insulators are “process-essential” and are necessary to build or assemble the finished product. The only way to control charges on these necessary non-conductive items is the use of ionization systems.

However, if an ionizer is out of balance, instead of neutralizing charges, it will produce primarily positive or negative ions. This results in placing an electrostatic charge on items that are not grounded, potentially discharging and causing ESD damage to nearby sensitive items.

It is therefore essential to regularly clean your ionizers and verify they function correctly. Below we have put together a list of tasks you need to perform with your ionizers on a regular basis.

Maintenance

All ionization devices will require periodic maintenance for proper operation. Maintenance intervals for ionizers vary widely depending on the type of ionization equipment and use environment. Critical clean room uses will generally require more frequent attention. It is important to set-up a routine schedule for ionizer service. Routine service is typically required to meet quality audit requirements.” (ESD Handbook TR20.20 section 5.3.6.7 Maintenance / Cleaning)

EIA-625, recommends checking ionizers every 6 months, but this may not be suitable for many programs particularly since an out-of-balance may exist for months before it is checked again. ANSI/ESD S20.20 section 6.1.3.1 Compliance Verification Plan Requirement states: “Test equipment shall be selected to make measurements of appropriate properties of the technical requirements that are incorporated into the ESD program plan.

Under normal conditions, an ionizer will attract dirt and dust (especially on the emitter points). To maintain optimum neutralization efficiency and operation, cleaning should be performed on a regular basis.

1. Case

Wipe the case with a soft cloth and deionized water. Fully squeeze the wiping cloth or sponge to remove any excess liquid. If a stronger cleaning solution is required, dab a soft cloth with mixture of isopropyl alcohol and deionized water (70% IPA and 30% DI water).

2. Emitter Points

The emitter points should be cleaned using specific emitter point cleaners or a swab dampened with Isopropyl alcohol. Below are general instructions on how to clean emitter points. However, each unit is slightly different so always refer to the ionizer’s manual.

  1. Turn the unit OFF and unplug the power cord.
  2. Open the top screen by loosening the screw and swinging the grill to one side.
  3. Clean the emitter points using the an emitter point cleaner or a swab dampened with Isopropyl alcohol.
  4. Re-attach the top screen.
  5. Plug in the power cord and turn the unit ON.
  6. Verify the performance of the ionizer by using a charged plate monitor or ionization test kit (see below).

Cleaning of Emitter Points using SCS 9110-NO as an example

With normal handling, the emitter points should not require replacement during the life of the unit.

Verification

Per ESD TR53 section 5.3.6.7.1 “The best practice is to measure the offset voltage and discharge times, clean the unit, including emitter points and air filters if present, offset voltage to zero (if adjustable), and then repeat offset voltage and discharge time testing. If the unit does not meet offset voltage specifications or minimum established discharge time limits, further service is indicated. Manufacturers should provide details on service procedures and typical service intervals.

Most companies will assign a number or otherwise identify each ionizer and setup a Compliance Verification / Maintenance / Calibration schedule. If the ionizers all test good, the data can justify lengthening the calibration period. If ionizers require adjustment, the calibration period should be shortened. Although ESD TR53 does not advise a test frequency, JESDD625-A (Revision of EIA-625) recommends ionizers be tested semi-annually, noting to use “S3.1 except the number of measurement points and locations may be selected based on the application.

Verification should be performed in accordance with the ESD Association ionization standard ANSI/ESD STM3.1.

Below are general instructions on how to verify your ionizer’s offset voltage and discharge time. Always refer to the User Guide accompanying your Charge Plate Monitor or Ionization Test Kit for proper operation and setup.

1. Testing Ionizer Offset Voltage:

The required limit per ANSI/ ESD S20.20 is less than ± 35 volts. Check your ionizer’s operating manual or consult with the ionizer manufacturer to determine what the offset voltage should be for your ionizer.

Charge Plate Monitor (CPM)

  1. Position the ionizer and charge plate monitor as shown below.
  2. Set the CPM to Decay/Offset mode.
  3. Set the CPM to decay and offset voltage mode with a starting charge at either + or – 1 KV and a stopping charge at either + or -100 Volts.
  4. Start the decay/offset test sequence on the CPM. This will take a few seconds.
  5. Record the decay time, and offset voltage as displayed on the CPM.

Positioning your Charge Plate Monitor for Overhead and Benchtop Ionizers

Ionization Test Kit

  1. Zero the charge plate by touching it with a grounded object. This can either be the finger of a grounded person or some other item which is connected to electrical ground. In either case, zeroing the charge plate should make the display on the field meter read zero.
  2. Hold the meter approximately one foot (30.5 cm) in front of the ionizer.
  3. Monitor the display. The value displayed is the offset balance of the ionizer, which is the difference between the number of positive and negative ions being emitted.
Testing Ionizer Offset Voltage using the SCS 718A Air Ionizer Test Kit

2. Testing Ionizer Discharge Time:

The required limit per ANSI/ESD S20.20 is “user defined”. Please refer to the ionizer’s operating manual or consult with the ionizer manufacturer to determine what this discharge time should be.

Charge Plate Monitor (CPM)

  1. Set the CPM to Decay/Offset mode.
  2. Set the CPM to decay and offset voltage mode with a starting charge at either + or – 1 KV and a stopping charge at either + or -100 Volts.
  3. Start the decay/offset test sequence on the CPM. This will take a few seconds.
  4. Record the decay time, and offset voltage as displayed on the CPM.

Ionization Test Kit

  1. After charging the plate of the ionization test kit, hold the field meter approximately one foot (30.5 cm) away from the ionizer.
  2. Monitor the display of the meter to see how quickly the 1.1 kV charge is dissipated to 0.1 kV.
  3. The speed at which this occurs (the discharge time) indicates how well the ionizer is operating.
  4. Repeat this procedure for both a positively and a negatively charged plate.

Some ionizers offer adjustment options (e.g. trim pots) which allow modification of the offset voltage.

However, if your ionizer is out of balance (and cannot be adjusted) or if the discharge time is out of specification, the ionizer will require service/repair by an authorized company.

Conclusion

Ionization is one of the best methods of removing charges from insulators and as a result plays an important role in controlling ESD.

Remember though: ionizers require periodic cleaning of emitter pins and verifying of the offset voltage and discharge time. Otherwise, instead of neutralizing charges, the ionizer will primarily produce positive or negative ions. The ionizer will therefore place an electrostatic charge on items that are not grounded, potentially discharging and causing ESD damage to nearby sensitive items.

Setting up an ESD-safe workstation is often more challenging than it first appears. There are many methods of controlling ElectroStatic Discharge (ESD), and typically, it requires a combination of these to curb all static problems. Unfortunately, there is no single method that will fill all requirements.

Wrist straps and work surface mats are probably the most familiar to everyone, draining charges from operators as well as from the product being worked on. But what if the static charge in question is on an insulator? Electronic products, by nature, will normally consist of conductors and insulators. Insulators at the workstation can be found on the product itself, tools being used, tapes for masking, even circuit boards. A static charge on an insulator cannot be drained by grounding, as you could with a conductive material.

Ionization

To effectively remove charges from insulators, we need to make the surrounding air more conductive. We have all seen a balloon cling to a wall because of a static charge, and we know that, after a period of time, it will drop. That is because the air is somewhat conductive and the charge eventually drains off. The problem with this concept is that it takes too long. The more conductive the air is, the faster the charge will be neutralized.


A balloon “stuck” on a wall by static charge.

The method most frequently used to increase the conductivity of the air is ionization.

Ionizers are useful in preventing electrostatic charge generation, ElectroStatic Discharge, ElectroStatic Attraction, as well as preventing equipment latch-up. Per ANSI/ESD S20.20 section 6.2.3.1. Protected Areas Requirement states: “Ionization or other charge mitigating techniques shall be used at the workstation to neutralize electrostatic fields on all process essential insulators if the electrostatic field is considered a threat.”

How do Ionizers work?

Most ESD workstations will have some insulators (e.g. product plastic housing) or isolated conductors (e.g. PCB board components not in contact with ESD worksurface) that cannot be removed or replaced. These should be controlled using ionization.

Ionizers create great numbers of positively and negatively charged ions. Fans help the ions flow over the work area. If there is a static charge present on an item in the work area, it will be reduced and neutralized by attracting opposite polarity charges from the air.

Ionization can neutralize static charges on an insulator in a matter of seconds, thereby reducing their potential to cause ESD damage.


Electronic enclosures are process-essential insulators

The charged ions created by an ionizer will:

  • neutralize charges on process required insulators,
  • neutralize charges on non- essential insulators,
  • neutralize isolated conductors and
  • minimize triboelectric charging.

How does Ionization fit into an ESD Control Program?

Ionization is just one component of your ESD Control Program. Before utilizing ionization, you should follow the fundamental principles of ESD Control:

  • Ground all conductors (including people) using conventional grounding methods (e.g. wrist straps or footwear/flooring system).
  • Remove all insulators, e.g. coffee cups, food wrappers etc.

“Air ionization is not a replacement for grounding methods. It is one component of a complete static control program. Ionizers are used when it is not possible to properly ground everything and as backup to other static control methods. In clean rooms, air ionization may be one of the few methods of static control available.” (ESD Handbook ESD TR20.20 Ionization, section 5.3.6.1 Introduction and Purpose / General Information)

  • Ionizers can be critical to reduce induction charging caused by process necessary insulators
  • Ionizers can be critical in eliminating charges on isolated conductors like devices on PCBs
  • Ionization can reduce ElectroStatic Attraction (ESA) and charged particles clinging and contaminating products.

The SCS Ionizer 9110-NO in Use

It is recommended to use ionizers with feedback mechanisms, so you’re notified if the offset voltage is out of balance.

Ionizers should be pieces of equipment that have serial numbers and are included in the company’s maintenance and calibration schedules. This is particularly critical to ensure that the offset voltage or balance is within acceptable limits. Otherwise, instead of neutralizing charges the out of balance ionizer will charge insulators and isolated conductors. The user, depending on the value and function of their products, must determine the appropriate frequency of maintenance and calibration.

Summary

The best way to keep electrostatic sensitive devices (ESDs) from damage is to ground all conductive objects and remove insulators. This is not always possible because some insulators are “process-essential” and are necessary to build or assemble the finished product. The only way to control charges on these necessary non-conductive items is the use of ionization systems. Applications include:

  • eliminating charges on process essential insulators,
  • neutralizing workstations where ESDS are handled,
  • removing charged particulates to create a static free work area.

For more information and to select the right ionizer for your application, check out our Ionizer Selection Guide.

Photo by Priscilla Du Preez on UnsplashAll US based SCS and Desco Industries locations will be closed for the holiday on Thursday, November 22nd and Friday, November 23rd in observance of the Thanksgiving holiday.

Customer service, production, shipping, and all other departments will be closed. No orders will be processed for the day. Normal operations will resume on Tuesday November 26, 2018.

We wish you a safe and happy Thanksgiving!

 

In today’s connected world, we are surrounded by home monitoring networks, fitness trackers and other smart systems. They all use an IoT platform to keep us up to-date with the current temperature in our house or the number of steps we have taken in a day. There are many different applications of IoT: Consumer, Commercial, Industrial, and Infrastructure, but is there a way to use this incredibly smart technology to improve ESD Control? Let’s take a look!

What Is The Internet of Things (IoT)?

The Internet of Things (IoT) is used everywhere today – from medical devices, to vehicles, to homes and more! Simply put, IoT:

  • Connects “things” in the physical world to the internet using sensors.
  • Collects data for these “things” via sensors.
  • Analyses the collected data and provides a deeper insight into the “things”.

Another broad definition provided for IoT is:

The Internet of Things (IoT) is the network of physical devices, vehicles, home appliances, and other items embedded with electronics, software, sensors, actuators, and connectivity which enables these things to connect and exchange data, creating opportunities for more direct integration of the physical world into computer-based systems, resulting in efficiency improvements, economic benefits, and reduced human exertions.” [Source]

 

Iot History-min.jpgThe history of IoT [Source]

 

What Is The Industrial Internet of Things (IIoT)?

As mentioned previously, there are many different applications for IoT, but The Industrial Internet of Things (IIoT) applies specifically to manufacturing and industrial processes.

It has slightly different requirements compared to consumer IoT products but the principle is the same: smart machines (incorporating various sensors) accurately and consistently capture and analyze real-time data allowing companies to pick-up problems as soon as (or even before) they appear.

 

Internet of Things (IoT) and Industry 4.0

IoT helped push the 3rd industrial revolution (machine automation) one step further. “Cyber Physical Systems (CPS) dominate the manufacturing floor, linking real objects with information processing, and virtual objects via the internet. The goal is to converge Operational Technology (OT) and Information Technology (IT).” [Source]

The 4th industrial revolution is also referred to as “Industry 4.0”. “At the very core Industry 4.0 includes the (partial) transfer of autonomy and autonomous decisions to cyber-physical systems and machines, leveraging information systems”. [Source]

Industry-4.0-shutterstock_524444866_pk_cut.jpgIndustry 4.0 as fourth industrial revolution [Source]

So, how can companies use the power of IoT and create accessible, real-time feedback on the status of their ESD Control Protected Area (EPA) and ESD control items?

 

Industry 4.0 IoT Platforms in ESD Control

ESD damages can be extremely costly – especially when it comes to latent defects that are not detected until the damaged component is installed in a customer’s system. Conventional ESD control programs incorporate periodic verification checks of ESD control products to detect any issues that could result in ESD events and ESD damage. The problem is that ESD control products (and the EPA as a whole) are not constantly monitored.

Take an ionizer for example: if a company uses ionization to handle process-essential insulators, the ionizers need to be fully reliable at all times. If an ionizer passes one check but is found to be out of balance at the next, the company faces a huge problem: nobody knows WHEN exactly the ionizer failed or if contributed to a charged insulator potentially causing ESD damage.

The Industry 4.0 IoT platform will be a game changer when it comes to creating a reliable and dependable ESD control program. Sensors collecting vital ESD information like field voltage, Electromagnetic Interference (EMI), temperature, humidity etc. in an EPA will help detect potential threats in real-time allowing supervisors to act even before an ESD threat occurs.

 

Advantages of Internet of Things (IoT) in ESD Control

Here is a (by no means exhaustive) list of advantages, IoT can bring to ESD Control:

Collecting Data

The day in an EPA can be busy. Taking the time to capture and record measurements of ionizers, wrist straps, work surfaces, automated processes etc. can be disruptive and is prone to errors. IoT allows data to be collected automatically without any input from users. This helps to increase the accuracy of data and allows operators and supervisors more time focusing on their actual jobs.

Smart-Factory.pngCollecting data is the first step to managing processes – more information

Analyzing Data

Supervisors have all the essential data in one place right in front of them and can make informed decisions; they can provide feedback and give suggestions in case of an ESD emergency. IoT allows to pinpoint areas of concern and prevent ESD events.

24/7 Monitoring

IoT continuously monitors processes and provides a real-time picture of them – no manual checks required. If a potential threat is detected, warnings will show-up immediately. There is no need to worry about potentially damaging sensitive devices because the next scheduled check of ionizers, wrist straps etc. has not been completed yet.

Cutting Costs

The number one reason for adapting an ESD control program is to reduce costs by:

  • Enhancing quality and productivity,
  • Increasing reliability,
  • Improving customer satisfaction,
  • Lowering repair, rework and field service costs and
  • Reducing material, labor and overhead costs.

Reduced Workload and Increased Productivity

IoT pushes all the above even further with the additional benefits of:

  • Reduced workload for operators: Data is collected remotely without any input from users. Operators are not disrupted in their day-to-day activities.
  • Reduced workload for supervisors: Supervisors don’t have to collect and analyze data from personnel testers, field meters, monitors etc. The system does it for them and will highlight any issues.
  • Further increases in productivity and cost reductions: An ESD program can be managed better and with fewer resources.

 

SMT-Line-Layout.jpgStatic Management Program (SMP): the next generation of ESD Process Control – more information

 

Conclusion

IoT will no doubt change ESD control and the way EPAs are monitored. Quantifiable data allows companies to see trends, become more proactive and improve the efficiency of their ESD process control system. IoT will support organizations’ efforts to make more dependable products, improve yields, increase automation and provide a measurable return on investment. Not only will this benefit users and supervisors, but the company as a whole.

SCS Static Management Program (SMP) is the only smart ESD system on the market that continuously monitors your entire ESD process control system throughout all stages of manufacturing. SMP captures data from SCS workstation, equipment and ESD event continuous monitors and provides a real-time picture of critical manufacturing processes.

For more information on how to continuously monitor your ESD control program and/or improve an existing program, request a free ESD/EOS Assessment or SMP demo at your facility by one of our knowledgeable local representatives to evaluate your ESD program and answer any ESD questions!

 

Resources:

Bill McCabe: Quick History of the Internet of Things..
Margaret Rouce: industrial internet of things (IIoT)
Michelle Lam: ESD Control in the World of IoT
Ian Wright: What Is Industry 4.0, Anyway?
Pascal Kriesche: Humans vs. machines – who will manage the factory of the future?
Industry 4.0 Resource: Industry 4.0: the fourth industrial revolution – guide to Industry 4.0

Have you ever walked across a car park on a bright cold winter’s day only to get zapped by your car’s door handle? It’s commonly known that these ‘zaps’ are much more common in cold dry weather. It begs the question: if there are less ‘zap, will using air humidifiers in a manufacturing environment prevent ESD damage of sensitive components? Let’s find out!

 

Humidity

Humidity describes the amount of water vapor in the air. There are 3 main measurements of humidity with the most common one being the relative humidity (RH). It is expressed in percent and describes “how much humidity there is in the air, compared to how much there could be. Meteorologists often use the relative humidity as a measurement to describe the weather at various places.” [Source]

At 0% the air is completely dry; at 100% it is so moist that mist or dew can form. The optimum relative humidity level is somewhere between 40% and 60%:

  • A lower relative humidity increases charge generation as the environment is drier.
  • If the humidity level is too high, condensation can form on surfaces.

 

Charge Generation and ElectroStatic Discharge (ESD)

The simple separation of two surfaces generates an ElectroStatic charge. Examples:

  • Unwinding a roll of tape
  • Gas or liquid moving through a hose or pipe
  • A person walking across a floor with heels and soles contacting and separating from the floor

 

Walking across a floor generates ElectroStatic charges.
Walking across a floor generates ElectroStatic charges.

 

The amount of static electricity generated varies and is affected by materials, friction, area of contact and the relative humidity of the environment. A higher charge is generated at low humidity or in a dry environment.

Once an item has generated a charge, it will want to come into balance. If it is in close enough proximity to a second item, there can be a rapid, spontaneous transfer of electrostatic charge. This is called discharge or ElectroStatic Discharge (ESD).

Going back to our earlier example of getting a zap from your car’s door handle:

  1. Charge generation: you walk across the car park with your soles contacting and separating from the floor. A charge is built-up on you.
  2. ElectroStatic Discharge (ESD): you touch the door handle. Charges move from your body to your car until both are balanced out.

 

Impact of relative humidity on ESD

Many people will notice a difference in the ability to generate static electricity when the air gets dryer (relative humidity decreases). Relative humidity (RH) directly affects the ability of a surface to store an electrostatic charge. “With a humidity level of 40% RH, surface resistance is lowered on floors, carpets, table mats and other areas. … the moisture in the air forms a thin protective “film” on surfaces that serves as a natural conductor to dissipate electric charges. When humidity drops below 40% RH, this protection disappears, and normal employee activities lead to objects being charged with static electricity.” [Source]

ESD Damage on an integrated circuit. No Magnification, 400x magnification, 5,000x magnification.

In an electronics manufacturing environment lower humidity may result in lower output from production due to an increase in ESD events during manufacturing processes.

 

Air Humidification and ESD

Air humidifiers are used to add moisture to the air and are commonly used in drier environments to keep humidity at a constant (optimum) level. Given that a lower humidity level increases the risk of ESD events, the obvious questions are:

  1. Can air humidifiers replace normal ESD Control measures?
  2. Are air humidifiers required for complete ESD protection?

Let’s address both questions:

  • Let’s be very clear about one thing here: air humidifiers cannot replace ESD Control measures.

As explained further above, ESD is caused by two items that are at a different electrostatic equipotential and want to equalize their charges. Adding moisture to the air using humidifiers will not stop this discharge from happening. The only thing you may achieve is a reduction in the number of ESD events. BUT: they will still happen; just walking across a carpet will generate a charge on an operator. If they then touch an ESD sensitive component, discharge will still occur and may damage the component. No humidifier will prevent this.

The only way to control electrostatic charges on a person or object is through ESD grounding – this will ensure any charges generated dissipate to earth:

For more information on how to create a ESD workstation and how to correctly ground all elements, have a look at this post.

Wrist-Strap.jpg
Grounding of an operator using a wrist strap

  • Low air humidity can increase the number of ESD events so it may make sense to keep a factory at a higher humidity level. However, there are many other factors that come into play when choosing the ‘right’ humidity for a manufacturing environment. The recommended humidity range is usually determined by the specifications of the devices and components being assembled. Increasing the humidity in an electronics manufacturing facility can help to reduce ESD events but increased humidity can lead to other unwanted quality issues in an electronics manufacturing environment such as corrosion, soldering defects and the popcorn effect on moisture sensitive devices.

A normal range for humidity in electronics manufacturing is between 30% RH and 70% RH. Some facilities try to maintain a constant moderate RH (~50%), whereas other environments may want lower % RH due to corrosion susceptibility to humidity sensitive parts.
And remember: you will not eliminate ESD by using humidifiers and keeping humidity levels at a higher level. You need an ESD Control Program in place to avoid ESD and associated damages.

 

Conclusion

Air humidification can help reduce the number of ESD events in an electronics manufacturing environment but at the same time there are other factors (e.g. moisture sensitivity of components) that need to be considered.

A lower relative humidity level increases charge generation as the environment is drier. This will result in more ESD events which can potentially damage sensitive components. The only way to protect sensitive components from ESD damage is by having proper ESD control measures in place and connecting operators, objects and surfaces to ground. This will ensure each element is kept at the same electrical potential and any electrostatic discharge is being removed to ground.

For more information on how to get your ESD control program off the ground or improve an existing program, request a free ESD/EOS Assessment at your facility by one of our knowledgeable local representatives to evaluate your ESD program and answer any ESD questions!