Our Circuit Boards are in Danger in the Winter!
Okay, technically circuit boards are in danger all the time, but more so in the winter. Why? Because it’s easier to shock them. And when circuit boards get shocked, they can fail immediately or start doing crazy, bad things. There are two main culprits when it comes to electrostatic discharge (ESD) damage and the first is: you. Yes, you and your habits when handling circuit boards. The second is mother nature and her affinity for changing seasons. But first, the basics:
(Remember, this is simplified to retain your attention.) Electrostatic discharge (ESD) happens when two electrically charged objects have a sudden flow of electricity between them. You can rub almost any two objects together and one will get positively charged and the other negatively, for example: the simple act of unwinding tape, and some objects hold charges longer and stronger than others. This is where YOU come in- by utilizing best practices, you can minimize the risk you pose to your boards. On the flip side, your new knowledge will allow you to maximize the shocks you bestow on your loved ones. For instance, you (a being who holds a lot of positive charge) could wear a polyester shirt (a material that likes to hold negative charges) and shuffle across the carpet in your socks to the unsuspecting human on the couch…ZAP!
Where does mother nature come in? Well, she likes to decrease the humidity in the winter, and decreased relative humidity lengthens the amount of time an object will hold a charge. Simplified, moisture in the air or on surfaces acts like a film through which charges can dissipate. Are you a numbers person? Okay, here’re a few examples:
Walking on carpet: 35,000 volts at 15% RH versus 1,500 volts at 65% RH
Walking on vinyl tile: 12,000 volts at 15% RH versus 250 volts at 65% RH
So, now you’re convinced ESD is a problem in winter...but what can you do about it!? Make it super humid! Just kidding, don’t do that unless you want to deal with corrosion and other side effects. You can shoot for some middle ground, like 40%, with an air humidifier, but you’ll want to take other steps, too. The following are anti-static devices and when combined are quite effective at drastically reducing the threat of ESD:
For all of our ESD prevention, assessment and detection products, you’ll find a feature in the description that states something like this: “Meets ANSI/ESD S20.20…” or “In accordance with ANSI/ESD S20.20…” What does this mean, exactly? In order to meet the need for standard level products in the electronics industry, the ESD Association established the ANSI/ESD S20.20, which helps organizations design, implement and maintain an ESD program to protect all ESD-sensitive electrical parts, assemblies and equipment. There are eight steps to follow in order to become S20.20 compliant, and we’ll go over each one of them:
1. Training
All personnel who handle or even just come into contact with ESD sensitive items most have initial and recurrent ESD awareness and prevention training.
2. Product Qualification
This is conducted during the initial selection of ESD control items to ensure that all of the chosen ESD control items meet the plan requirements. This list of these items should be included on your ESD Control Plan, a controlled document approved by upper management.
3. Compliance Verification
The compliance verification plan identifies electrical properties needing checked, measurement limits, and test frequencies per manufacturer and industry recommendations.
4. Grounding/Equipotential Bonding Systems
In this step, you connect ESDS items, personnel and other conductors to the same electrical potential. The 3rd-wire AC electrical equipment ground is the preferred, recommended ground reference.
5. Personnel Grounding
The two options for grounding here are either wrist straps or heel grounders. If person will be seated, wrist straps must be the product of choice. A flooring system must also be installed if heel grounders are used.
6. ESD Protected Area (EPA) Requirements
You must handle ESDS items, parts, assemblies and equipment without ESD protective packaging in an EPA Protected Area with clear boundaries. The plans for these must evolve to keep pace with costs, device sensitivities and the way they are manufactured.
7. Packaging Systems
Define ESD protective packing requirements for both inside and outside the EPA. When you are moving ESD susceptible devices outside the protected area, you must package and enclose the device in an ESD shielding bag.
8. Marking
Mark ESDS items in accordance with other customer contracts, purchase orders, drawings or other documentation.
]]>We’ve harped on it time and time again: Electrostatic Discharge (ESD) prevention is so important! Electronic build-up that is undetectable to humans still has the capability to damage or even destroy your electrical equipment.
If not properly maintained, ESD damage can really set you back in terms of production cost and time. In fact, the ESD Association estimates that the cost of losses due to ESD ranges between half a billion dollars to $5 billion each year. This is because ESD damage can be tricky to detect. Some devices stop working altogether (known as catastrophic failure) while others experience partial damage over time that cause an overall drop in efficiency (known as a latent defect).
If there were a way to save yourself cost and labor in the long run, would you do it? Of course you would! The good news is that there are ways to save cost and labor when it comes to ESD prevention, and it starts with detection. Here are three of our most recommended products for detecting, measuring and monitoring ESD events so you can ensure that the ESD control program you have in place is working:
The SCS CTM082 both detects and counts ESD events for control program troubleshooting and improvement. The four-digit display counts the number of ESD events that have occurred at or above the alarm threshold and resets every time the power is turned off. Get as close as you can to the suspected source of the ESD event and use the indicator to detect and measure its relative strength. When the strength of an event exceeds the set threshold, the LED will turn red. Shop the SCS CTM082 here.
2. SCS CTM048-21 ESD Events Sensor Meter
This user-friendly and portable meter serves as a measuring instrument for most ESD signals and measures the magnitude of ESD events. It can also estimate the magnitude for CDM, HBM and MM models. The device’s touch screen allows users to easily navigate through the features and the speaker and headphone alarm outputs allow you to use it in a noisy place. The microsSD card within the device can log data and then be exported to an Excel sheet for quick analysis. Buy the SCS CTM048-21 here.
3. SCS 770063 EM Aware Monitor, Field & Ionization, Ethernet Output
The SCS 770063 is compatible with the SCS Static Management Program (SMP) and through it, collects data including ESD event count, changes in the static voltage field and ionizer performance. Because of this, it is able to identify problematic environments and qualify tools for handling ESD-sensitive devices. This monitor, as well as all the products listed, meets the requirements of S20.20, which states that continuous monitoring should be considered or even mandated. The data collected by device allows you to see overall trends and improve the efficiency and quality of your ESD control. Shop the SCS 770063 here.
As always, if you have questions about any of the products listed, be sure to contact us and we'd be happy to help!
]]>Think back to the times you spent hours working on a school project or typing a term paper before it was due. The hard work and meticulous planning was worth the perfected final result. Now imagine it being the due date and right before you submit it you close out of the document without saving any of the work or drop the 3D model you crafted on the floor, smashing it to pieces. You can probably imagine that feeling of devastation you would have felt when you realized the project you spent so long on is now suddenly useless.
Why waste hours of your life working on your electronic components if you’re going to expose them to moisture and meet the same fate as that school project? If you’re storing your electronics in damp, dark or humid environments, you just might end up with a final result that is just as useless. There are ways to avoid this, though, and there are products that you can buy that will ensure your components stay in top condition.
Here are a few of our recommendations:
Moisture barrier bags are comprised of multiple layers of plastic and aluminum that are designed to keep out moisture. They are one of the most effective packing solutions for sensitive components and protect against humidity, moisture, oxygen, grease or other airborne contaminants that could cause damage. The bags feature a vacuum seal that also protect against damage due to other events such as ESD (Electrostatic Discharge) and EMI (Electromagnetic Interference). Check out the moisture barrier bags that GoKimco offers here.
2. Humidity Indicator Cards
Humidity Indicator Cards, or HIC’s, are cards that indicate humidity levels inside sealed packaging. They contain a moisture-sensitive chemical that will change color if a great enough humidity level is detected. The SCS 6HIC200 6-Spot Humidity Cards respond to various levels of humidity with a visible color change from blue to pink. Each can contains 200 cards, which is a great value for your purchase. Pair these with your moisture barrier bags to provide the best protection for moisture sensitive items.
3. Desiccant Packs
Desiccant packs are used alongside humidity indicator cards and placed inside moisture barrier bags to absorb moisture. Packs come in many different sizes and in addition to absorbing moisture, can also absorb gas, vapor or odor. The porous pouch allows moisture to seep through and be absorbed by the desiccant inside. The Desco 13844 Desiccant Packs are reusable and can be reactivated by oven drying. Even when saturated by moisture, the desiccant pack remains dry. Together, the moisture barrier bags, humidity indicator cards and desiccant packs make up what’s known as a “dry package”.
Conformal coating is a protective chemical that can protect sensitive electronics from moist environments and electrical shorts by creating a barrier of insulation. Although not designed to be a total sealant, conformal coatings will also allow moisture trapped in PCBs to escape. There are different ways to apply a conformal coating including dipping, spraying and brushing. The ACL 8690 Acrylic Conformal Coating Spray is applied by spraying and has an operating temperature of -75 degrees F to 270 degrees F, so check it out.
Those are our most recommended products for moisture control for your sensitive electronic components so you can rest assured knowing that your best work will be preserved and protected against any sort of environment. Have questions? Contact us here.
]]>ESD Flooring, or electrostatic discharge flooring, serves as way for electricity that accumulates on a person to be controlled and discharged into a ground point. Why is this important? Think about how many times you can remember the shock of static electricity after touching a metal door handle or even another person. To you, the transfer of electricity and the shock you feel from it can be jarring and even quite painful. To a printed circuit board or any other sensitive electronic component, the electrostatic transfer could damage or even destroy the parts you’ve worked so hard to create. In addition, working in flammable environments without ESD flooring could put you at risk for spark creation and explosions, causing injury or even death in some cases.
There are a variety of different ESD floor types to choose from including vinyl tiles, carpet tiles, rubber flooring, epoxy flooring, mats and floor finish. The type of flooring you decide upon will depend on your desired price point and the floor’s anti-static property levels and conductivity. Regardless of which floor type you go with, however, there will be some sort of maintenance required since the build up of dirt or dust on an ESD floor could prevent the static from dissolving properly into the ground.
The cleaning process can vary depending on which ESD floor you choose. For example, carpet and rubber only require simple maintenance in the form of vacuuming and steam cleaning for the carpet and mopping for the rubber. Vinyl is the most difficult to maintain, requiring regular buffing. It’s important to note that the process of cleaning ESD floors is not the same as cleaning the regular floors that you might have in your house. Many household products contain silicone, which leaves a residue behind and weakens the integrity of your ESD surface.
If your ESD floors are already treated with an ESD finish, the maintenance process could be made easier and your floors might be preserved longer. GoKimco offers several different ESD-safe finishes that are designed to provide high performance static control on any sealed or hard surface. These finishes have a durable, non-slip formulation and a high resistance to abrasion, all for an affordable price. You can find more information about these products here. We understand that the process of deciding whether you need an ESD finish might be confusing if you’re not sure which ESD floor you wish to choose yet. If you have any questions about the maintenance or cleaning process, be sure to contact us and we’ll be happy to assist.
]]>- Homogeneous (Vinyl and Rubber)
Offering differing electrical performance, static mats can be made from solid sheets, suspended particles, or multiple layers.- Homogeneous – Used for tables or floors and made of more durable material.
- Three Layer – Used for tables and have excellent electrical properties.
- Two Layer Vinyl – Used for tables and provide a low cost solution.
- Two Layer Rubber – Chemical resistant, heat/solder tolerant, and have excellent electrical properties.
Although most people may have heard about electrostatic discharge (ESD), they may nevertheless entertain perceptions that are not accurate. In fact, even people who work in manufacturing sometimes succumb to misinformation (or a lack of knowledge) about ESD.
Because electrostatic discharge is such an important and prevalent phenomenon, everyone needs to know about these myths.
What Are Ten Such Myths?
1) Electrostatic discharge is a relatively-modern problem.
Actually, going back into the 1400s, care had to be taken to protect against black-powder mishaps at munitions facilities. Forts in the Caribbean and in Europe, therefore, instituted early forms of ESD control.
2) ESD is only an issue with PCB, explosives and sawdust facilities.
In reality, most manufacturing facilities have to keep an eye on ESD, especially in regards to electronic products/equipment.
3) ESD problems are a rare phenomenon.
Many times items are damaged or disrupted by ESD and, because no outward signs are present, people remain unaware of the damage. These disruptions are very common.
4) Discharging fingers/tools before using them obviates any potential ESD mishaps.
Unless the user are perfectly still, the human body (and tools) can rebuild a charge. This is not a suitable (per se) control option.
5) Once products are mounted on circuit boards, ESD mishaps cannot occur.
Just because components are mounted on circuit boards does not remove ESD dangers. In fact, charges may be more easily channeled to sensitive parts once circuit boards are involved.
6) Only circuit boards with complementary metal oxide semi-conductor (CMOS) are subject to ESD issues.
While most circuit boards contain CMOS-components, all circuit boards are susceptible (in one way or another) to ESD damage
7) One has to touch an item to transmit an ESD to it.
Actually, all that is needed is bringing the item near an electrostatic field to create potential ESD problems.
8) An item that passes a peremptory test after a potential ESD incident is probably okay.
Actually, damage as a result of ESD can manifest itself later or in ways that may be difficult to detect with any measuring device.
9) A printed wiring board (PWB) permanently protects a circuit board.
Actually, while the withstand-voltage may be increased with a PWB, it is no guarantee that ESD will not be a problem.
10) Grounded metal can provide a safe haven from ESD.
Static discharge can still reach or build on items mounted on or sitting on grounded metal.
Conclusion:
Yet another myth is that there isn’t much you can do against ESD. Actually, a number of effective products can be used to protect against ESD, including anti-ESD wrist straps, mats, chairs, casters, sealed barrier bags, non-conducting materials, etc.
While it may be impossible to completely protect against ESD, precautions can be taken which greatly reduce chances for mishaps. By knowing what to do and not succumbing to popular myths, you can help reduce the chances for ESD damage to sensitive, expensive equipment and components.
]]>Modern electronics are more prone to suffering damage through electrostatic discharge (ESD) than their technological predecessors.
One reason for this is LCD TVs, mobile phones and other high-tech gadgets feature chip-sets below the 130 nanometer value. Electronic components in these devices are best suited for DC voltages less than 3.3 volts. Even worse, ESD protection requirements for these devices are 500 volts instead of the standard 8 kilo-volts.
How can you combat these ESD deficiencies? It starts with modifying internal components so ESD damage can be kept to a minimum.
A circuit board designer can employ four diffferent strategies for boosting ESD protection in an LCD circuit board:
Where an ESD device is located and how it is laid out is key to enhancing ESD protection. Both the LESD and LGND can increase the clamping voltage with a minor length increase. Taking each trace length from 0.5 centimeters to 1 centimeter, for example, can boost the overall clamping voltage by as much as 75 percent.
Putting the ESD device as close to the ESD point of entry as possible is an essential step. This makes the ratio of LPORT to LIC smaller. The LIC is non-linear, so it will create a buffer to the ESD pulse by making the voltage drop as it nears the IC.
Buffer resistors are needed if on-chip ESD structures are exposed to too much current. Adding 10Ω worth of buffering resistance can reduce peak current flow by as much as 50 percent.
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