Static Control Tips and Tricks

ESD Controls – Prevent, Dissipate, Improve!

by admin on June 8, 2010

In the workplace, ESD can often be a dangerous and costly cause of device failures. So, let’s take action to correct this matter. According to SiliconFarEast.com, a semiconductor manufacturing reference, there are three major categories of ESD controls: (1) prevention of static charge build-up, (2) safe dissipation of any charge build-up, and (3) improvements in the awareness of ESD-sensitive products.

Although the first two categories are similar, some charge build-up can be avoided altogether by using the proper materials. For instance, ionizers will neutralize newly generate charges and will therefore prevent charge build-up. Also, avoid equipment with moving parts that can also generate new charges.

On a similar note, safe dissipation is important when it comes to controlling ESD. Because not all charge build-up can be prevented, it needs somewhere to go without being damaging to the static sensitive device. Accordingly, a proper grounding system should be in effect within a factory environment, allowing charges to flow to the ground. In addition, properly grounded garments (such as the wrist strap to the left) add protection.

Thirdly, improvements can always be made to assist in the control of ESD. Training and retraining of ESD precautions is of utmost importance, especially to individuals working on the production line. Afterwards, a standard ESD audit of the manufacturing line is necessary to maintain ESD compliance. Also, ESD-sensitive items need to be identified, along with their respective levels of sensitivity.

Save yourself time, money, and stress by taking these simple ESD control measures. Remember… Prevent, Dissipate, Improve!

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Learn About ESD from a 1987 Training Video

by admin on May 19, 2010

Problems caused by static electricity date back hundreds of years. In the 1400s, precautions had to be taken to prevent black powder from igniting and in the 1860s, paper mills grounded equipment to dissipate static electricity. ESD became a big issue several decades ago when electrical devices became faster, smaller and more susceptible to electrostatic discharge.

Here’s part one of a Apple training video from 1987. It appears the goal of the video (which is separated into four parts for YouTube) is to educate Apple employees on how to protect static sensitive devices by shielding devices, grounding themselves and keeping all plastic/synthetic materials away.

The Shocking Truth – Part 2

The Shocking Truth – Part 3

The Shocking Truth – Part 4

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Wearing Gloves or Finger Cots to Handle PCBs

by admin on July 24, 2009

One would think it is common sense to wear gloves or finger cots when holding, inspecting, etc… printed circuit boards, but unfortunately it’s not uncommon to see manufacturers whose employees do not regularly wear hand protection.

We found a great video (it’s really just audio in a video player) talking about the subject of wearing gloves while handling PCBs. The video is fairly short (7 minutes) but the two guys are experienced and knowledgeable plus they’re easy to listen to and very personable. If you’d rather not listen to the Assembly Brothers, below is a recap of what they had to say.

Wearing ESD-safe gloves protects boards from ESD but the gloves also protect boards from contaminants, and this simple step is often overlooked. Both dirt and oil are typically present on our hands at any given time, and handling a PCB with bare hands will transfer the dirt and/or oil to the board. The addition of the containments can cause a myriad of board problems including weaker solder joints. Fluxes do not reliably remove the contaminants; they’ll remove oxides but not dirt, oil, etc…

Bottom line: EVERYONE who touches a PCB should be wearing gloves or cots of some sort. On top of wearing hand protection, you have to wear the gloves correctly…cutting the finger tips from gloves for better dexterity defeats the purpose of wearing any hand protection.

For those that do track defects, you will definitely see an improvement if wearing gloves or some sort of hand protection is mandated.

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All-Spec Stat-Crete Installation Instructions: Part 2

by admin on March 5, 2009

Two weeks ago we posted part 1 of the All-Spec Stat-Crete Installation Instructions. The second part is below.

How to Install 2-Part Epoxy Paint on Concrete Floors

1. Using a degreaser, deep clean the existing concrete floor

Apply a degreaser solution with a watering can or mop; continue with the manufacturer’s instructions for cleaning the floor. Be sure to remove all of the solution using a mop or wet-vac.

2. Etch with Prepare, a concrete acid etching solution

Use clean water to uniformly dampen the area to be etched. Mix one part Prepare (etching solution) with one part cold water and evenly apply with a watering can and then spread with a deck brush. Let the solution sit on the floor for approximately five minutes or until the foaming stops (see foaming picture to the right). Scrub the floor with a buffing machine and a staggered bristle zim-grit or nylo-grit type brush or deck brush to ensure deep cleaning. Remove the etching solution with a wet-vac and rinse using a mop or watering can and clean water. Thoroughly remove all rinse water and make sure all equipment used is completely rinsed with clean water.

Note: Prepare contains hydrochloric acid and other chemicals…be sure to take the necessary safety precautions including proper ventilation. Do not use Prepare on marble, terrazzo, limestone, or other calcium containing surfaces.

3. Coat the floor with Stat-Crete dissipative epoxy

Add the premeasured catalyst to the epoxy base and gently stir until the two have been thoroughly mixed; let the mixture stand for five minutes. Note: make sure you mix only what is needed since the catalyzed Stat-Crete should be used within six hours of mixing.

Using a short nap roller, apply a thin coat of the Stat-Crete and let dry for five to seven hours. Apply a second coat and let dry for 12 hours before allowing light foot traffic. Complete curing of the floor will take about five to seven days.

Below are a couple things to keep in mind when applying Stat-Crete to concrete.

  • If you are applying Stat-Crete to a concrete floor that has been coated in the past. Strip any areas that still have the old coating.  After washing, etching, and rising, allow the floor to dry completely before applying the Stat-Crete.
  • If you are applying Stat-Crete to a new concrete floor, sweep and thoroughly wash the area. Then using Prepare, etch and rinse the floor. It is important to note that new concrete floors should be given at least 30 days to cure and it is recommended to avoid applying Stat-Crete to floors colder than 60°F.

4. Seal & protect with Stat-Seal

Apply one or two thin even coats, allowing Stat-Seal to dry for approximately 30-45  minutes (depending on humidity and temperature) between coats. Wait two hours between the last coat of Stat-Seal and the first coat of Stat-Coat for the best results.

5. Finish with Stat-Coat

Apply thin, even coats of Stat-Coat using a synthetic mop; let dry for 30-45 minutes. For best results, apply three to five coats of the finish; preferably not in high humidity or high temperatures.

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All-Spec Stat-Crete Installation Instructions: Part 1

by admin on February 19, 2009

This is part one of a three part series with instructions on how to install All-Spec’s new Stat-Crete 2-part epoxy paint.

Here are a few features of the dissipative epoxy paint:

  • Surface resistivity: <107 Ohms2 Max/Cm2 @ 40% relative humidity
  • Static decay rate of <0.2 seconds using FTMS 101B, method 4046
  • Works on a wide range of concrete and ceramic surfaces
  • Resistant to abrasion and many chemicals and solvents
  • Available in a variety of sizes and colors

How to Install 2-Part Epoxy Paint on Existing Tile Floor

1. Remove existing finish with the All-Spec Eliminator floor stripper, a cold water floor stripper

Using cold water, mix 16 ounces per gallon of the floor stripper for routine stripping, 32 ounces for medium build-up or 128 ounces for heavy build-up. Mop on the solution and let stand for five minutes. Using a wet vacuum or automatic scrubber remove the finish; be sure to remove any residual floor finish by light rinsing or mopping. Let the floor completely dry before applying Stat-Crete.

Note: All-Spec Eliminator is not for use on older linoleum tile floors or asphalt tile. The stripper may remove the dye, especially from dark colored tiles.

2. Create a conductive floor using the All-Spec Stat-Crete epoxy paint

Add the pre-measured catalyst to the epoxy base and stir until the catalyst has been completely mixed in. Let the mixture stand for five minutes. Using a short nap roller, apply a thin, uniform layer of the dissipative epoxy. Allow the first coat to dry for 5-7 hours before applying a second coat. It is important to mix only the amount needed for immediate use and the paint should be used with six hours of initial mixing. Freshly painted floors can withstand light traffic after 12 hours of curing but maximum durability wont be achieved until five to seven days after painting.

Note: Avoid using this paint in areas that are frequently exposed to standing water.

3. Seal and Protect Dissipative Floor with All-Spec’s Stat-Seal

Vacuum the floor to remove any loose dirt or dust; then wash the floor with All-Spec’s Stat-Clean. Once the floor is dry, apply thin uniform coats and allow the sealer/finish to dry for about 30 minutes before allowing people to walk on the floor.

4. Maximize ESD protection with All-Spec’s Stat-Coat, a static dissipative floor finish

In temperatures of 60°F or warmer, use a synthetic finish mop to apply thin, uniform coats of the finish. Optimum appearance is achieved by waiting 30-45 minutes between each of the three to five recommended coats of finish. Avoid application in high humidity as this can extend drying times.

To maintain dissipative properties, sweep the floor everyday with an untreated mop to remove any sand or dirt that may scratch the floor. Damp mopping the floors on a regular basis is also a good idea to remove any substances that could decrease the conductive properties of the coating.

If you have any questions about All-Spec’s Stat-Crete, please contact our customer service by phone (1-800-537-0351) or email customer service.

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