ESD Systems’ ESD Technical Newsletter
Issue 4, October 1998: Volume 1
Sender : ESD SYSTEMS, 19 Brigham Street #9, Marlboro, MA 01752-3170
Phone : 508-485-7390
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IN THIS ISSUE:
IC INVENTOR SEES 'CONTINUOUS CHANGE'
Article Summary from "Kilby: 'The changes are tremendous' "
Source: EE TIMES, Issue 1028, Wednesday, September 30, 1998,http://www.eet.com
Jack Kilby, inventor of the Integrated Circuit (IC) "integrated phase-shirt oscillator" while at Texas Instruments in 1958 shared the title of first IC inventor with the late Robert Noyce then from Fairchild.
The state of today's semiconductor industry is the result of a cumulative effort from tens of thousands of the worlds best engineers and scientist working for over 30 years.
The evolution of semiconductor manufacturing has gone from a few large companies with broad product offerings to a large number of smaller groups that specialize in various areas of business such as CAD specialist, packaging specialist, and photomask specialist.
Electronic function cost reduction has been tremendous, from over $10 for a single Silicon transistor in 1958 to a reduction of well over a million. Reductions in electronic prices are happening faster than the reduction in the costs of manufacturing. This cost difference needs to be offset by an increase in volume and an increase in ESD Control practices or there will be trouble, as some of us have seen recently.
Change is a big part of this business. The transistor went through six completely different designs between 1950 and 1960.
Electronics are everywhere in our lives, from are automobiles to our neckties, there is an ever growing expansion of usage for these devices which will further drive the need for ESD Control.
The cost of an IC is expected to continue to decrease with time. Conversely, the growth in electronic based products is expected to continue to increase. This product growth is primarily from an ever-increasing number of smaller discrete products that form larger devices like the Personal Computer.
Kilby ascertains that the PC industry slowdown is the fault of Mr. Gate. As in the past, the development of new software programs for new applications begat the need for faster and more powerful PCs, but this development has tapered off and coincides with the need for more powerful PCs.
What will revive this industry is to come up with new functions for PCs that will increase the number of people who think they need a PC as well as to increase the need for more sophisticated PCs.
NEPCON WEST 1999, ANAHEIM, CA
NEPCON West '99is the World's leading source for electronics manufacturing solutions.
With nearly 1,000 global companies exhibiting in over 300,000 net square feet of space, display the newest and best technological advances in electronic manufacturing. Attendees of over 31,000 industry professionals including engineers and managers involved with designing, manufacturing, testing and servicing of electronic products attend NEPCON. Attendees also include corporate managers and general managers responsible for development/management at OEMs and contract manufacturers. Industry buyers from more than 50 countries now attend NEPCON West.
As the World's leading source for electronics manufacturing solutions, NEPCON continues to meet the growing needs of the electronics manufacturing industry. From design through assembly, the solutions-oriented conference and special events provides practical information and address the questions every member of the electronics manufacturing team wants answered.
We encourage you to stop by the ESD Systems exhibit to learn more about our wide-variety of Electrostatic Discharge (ESD) Control products. This is a great opportunity to meet some of our ESD Systems’ team. We look forward to seeing you there.
For More Information:Contact NEPCON at Reed Exhibition Companies, 383 Main Avenue, Norwalk, CT 06852-6059. Via Telephone: (800) 467-5656 or surf to http://nepcon.reedexpo.com/west/index.html
ESD Q&A CORNER
The following questions and answers are selected from our FAQ WEB Page:http://www.esdsystems.com/esd_q&a.htm concerning ESD Floors and grounding.
Q1: Much of our manufacturing floor is covered with dissipative tiles, but a small area is not covered. The floor of the plant is concrete and I was wondering if this is sufficiently dissipative? Would it help to have a conductive coating such as a conductive wax applied to it? - Anonymous, Scientific Atlanta Canada, Burnaby, Canada
A1: Concrete alone does not constitute a sufficient ESD floor. Even on the ground floor, where ground water may seep up through the pours and make the concrete conductive, you will always have inconsistent dry or dead spots. A conductive wax would definitely help. We prefer to refer to wax as floor finish, since there is no wax in the finish and wax is insulative. Before coating the concrete, you will want to seal the concrete (only if you are on the ground floor) to avoid water from causing adhesion problems and to increase the coverage of the floor finish (by decreasing the porosity of the floor). Other solutions include, coating the bare concrete with conductive paint, using conductive tiles or matting, installing conductive carpet or just marking off the area as non-ESD safe
Q2: I have some benches on carpet, can I get away with ESD mats and ground straps? - Anonymous, Campbell, CA
A2: Assuming the carpet is insulative and non-antistatic, you'll need to protect the benches by placing them and the work area on grounded ESD floor mats, extending at least 3 feet from the working area. In addition, the bench tops should also provide protection by using grounded ESD bench mats anywhere you work or store ESD sensitive components. You want to ensure that theESD bench mats are dissipative so they don't cause ESD events. Depending on activity, ground straps should be used on both the feet (left and right) and one wrist (or smock) per person. Minimum protection (once floor and bench mats are installed) is to employ a wrist strap and a CPG (common point ground) placed near the front of the bench (for easy and immediate access).
Q3: If we are using a wrist strap and floor mats, would it also be necessary to require heel grounders? If heel grounders are used, is a floor coating necessary? - Richard, Santa Clarita, CA
A3: If the personnel are mobile and walking around with sensitive devices, then Absolutely, use Foot Grounders. Foot Grounders add additional safety to your processes when handling ESD sensitive devices. If you move ESD Sensitive products or devices between workstations, then the carts or people should be grounded via Foot Grounders or shoes (people), drag chains (carts) and used in conjunction with a properly grounded floor. Using a grounded floor mat or applying Statproof® Floor Finish are very good ideas around the sensitive areas because they also tend to have excellent antistatic properties that limit tribocharging. To fully utilize safe ESD practices when mobile personnel are necessary, then a complete ESD floor covering in conjunction with ESD Footwear is highly advised.
PRODUCT UPDATES (NEW!)
ESD Systems NEW Full-Line Product Color Catalog is OUT! You can get your own personal copy by filling out our on-line request form found at:http://www.esdsystems.com/default.asp?PageNo=CATALOG-REQUEST This 68 page catalog includes a large selection of ESD Control products from one source for your convenience. ESD Systems has developed another patent for the Foot Grounder, which includes better continuity rubber cups. Remember that ESD Systems (formerly Plastic Systems) had the 'first' Patent on the Foot Grounder.
New Items Include:
Topics: ESD Floors and Ground (gleaned from paper http://www.esdsystems.com/whtpaper/wp_floorcare.asp)
ESD (electrostatic discharge) is a growing problem in this electronic age. A simple touch from a person in a non-static controlled environment can damage an electrical component with charges up to 35,000 volts of electricity. To combat this, static control solutions are needed.
Taking care of static generated on the floor is a key place to start any ESD control program. Static starts to build on people as they walk around. As more and more companies are relying on their employees to be more mobile due to the changing work requirements and space issues, static control needs to start from the floor up. This increases the effectiveness of other static control devices, such as the wrist strap, by fighting static at the source.
So how does your company stack up?Does your floor provide proper grounding for mobile employees, equipment and visitors? By answering the following "self test" questions, you can evaluate your company based on your needs and requirements for ESD floor protection.
Does your company manufacture, handle, transport, test or repair static sensitive devices?
Does your company manufacture, build, test or repair these devices on the shop floor?
Do your employees wear heel grounders or ESD shoes?
Do your employees walk ungrounded while handling or transporting ESD sensitive devices?
Are your ESD sensitive parts stored in areas that require employees to be mobile to kit them?
Are your ESD sensitive devices kitted and/or transported on pushcarts?
Do you use pushcarts that are grounded with a drag chain?
Do assemblers need to disconnect their wrist strap to retrieve, move, or test ESD sensitive devices?
Are your assemblers and operators grounded using an ESD chair?
Do you use ESD safe chairs that ground using a drag chain?
If you answered YES to ANY of these above questions, you are in danger of damaging components sensitive to ESD and may want to allow your floor to ground your ESD carts, chairs, mobile assemblers and operators.
So, what steps can be taken to help reduce this problem of static generation? ESD Floor protection can help stop this problem. Depending on your existing floor, it may be possible to easily gain ESD protection from existing vinyl, concrete, sealed floor surfaces and carpeting with little investment. This is where ESD floor finish comes in.
ESD Floor Finish
Good ESD floor finishes will provide the ability to ground mobile personnel and eliminate the static charges generated by walking across the floor. They are easy to apply and are easily plugged into an existing floor finish program. Ninety percent of the cost of maintaining a floor is labor, changing your current floor finish to a good ESD floor finish (at about the cost of $0.02 more per square foot (sqft). in material cost) will give an ESD safe and grounded floor. There are several ESD finishes out on the market today. To help you select the right ESD finish for you, here are some tips and questions you can ask:
No-zinc finishes are great finishes for companies that have policy or are environmentally reducing their companies waste discharge of metals that are found in shampoo, cleaners and finishes. With non-zinc floor finishes you will typically sacrifice gloss and durability as the elimination of the zinc cross linker. A quality no-zinc finish will minimize these sacrifices. The tips mentioned above also apply for no-zinc finishes.
Good ESD floor finishes will provide most floors with the ability to ground mobile personnel and eliminate the static charges generated by walking across the floor. They are easy to apply and are easily plugged into an existing floor finish program.
Good quality floor finish will remain in service from 3 months to 6 months depending on floor traffic, type and frequency. In one years time for high traffic you could expect to use 6 coats in total, three initial coats plus three individual coats every three months. For low traffic areas, you could expect four coats total in one year, three initial coats and one single coat after six months. Periodic testing will always tell you how the ESD floor finish is performing electrically and if it needs maintenance. As the finish wears away, the resistance will increase depending on the thickness of the finish on the floor.
Grounding a floor finish is easy. Some finishes may not require grounding depending on the square footage covered (see below). Finish and or paints can be grounded by connecting a ground wire, flat wire or copper strip from a grounded outlet (connect to the center screw or to the box itself) running the wire down the wall and extended enough to get good contact to the floor. It can be bolted, screwed or adhered to the floor or to a plate that in turn is bolted or adhered to the floor. Look to get 2+ square inches of contact from the wire, copper pad or flat wire that is bolted to the floor. This surface is then finished over to connect it and ground to the floor finish. This may be needed every 20’ along the perimeter or as RTG (resistance to ground) readings indicate. Some finishes are able to drain a 5000 volt charge to zero in less that .1 seconds (per FTMS 101C method 4046) and not require actual hard ground points. These finishes usually require at least a square footage of 50 or greater.
How do you know if floor finish is right for you? Depending on your existing floor, you may be able to gain ESD protection by using floor finish on your floors to allow you to properly ground your employees and equipment. If you are choosing vinyl tile, concrete, or carpeting, you should consider ESD floor finish as an option. These floor materials, and their applications, are illustrated here:
Existing Vinyl Tile:
Vinyl tiles, commonly referred to as VC tile (vinyl composite tile), and comes in 1-foot square tiles that are installed directly on concrete or sub flooring. These tiles are large static generators and need to be finished with a good protective ESD floor finish to fight static generation.
If your vinyl tile is an ESD tile, you may still want to finish it with a good protective ESD finish. ESD tile companies have discouraged the use of ESD floor finish primarily because they have marketed the tiles as not requiring an ESD finish. It turns out that an ESD vinyl tile left bare will become scratched and stained over time. This is fine if the appearance of the floor is not a concern but if you are looking for a nice glossy floor the ESD tile needs a protective ESD finish on top. Floor tiles without a protective finish tend to become scratched and dull due to floor traffic. ESD floor finish helps prevents this. It is just a whole lot easier to maintain a floor finish than to sand or bleach out scratches and stains on tile. Good quality Floor finishes will remain in service for 3 to 6 months depending on floor traffic, type and frequency. In one years time for high traffic you could expect to use 6 coats in total, three initial coats plus one individual coat every three months. For Low traffic areas, you could expect four coats total in one year, three initial coats and one single coat after six months.
If you have concrete floor that is in good shape you have the option of applying an ESD finish to its surface to provide an ESD safe floor. Floor finish can be applied right onto a concrete surface as long as its clean, dry and level. Concrete may be sealed prior to applying of a floor finish to fill in the surface pores and gain more coverage of the floor finish. For concrete with moisture concerns, a sealer with moisture barrier properties will protect the surface adhesion of a paint or finish from separating due to moisture. Painting the concrete is also an option and can provide a uniform color in addition to sealing the porous surface and increasing the coverage of the floor finish. Good quality Floor finishes will remain in service for 3 to 6 months depending on floor traffic, type and frequency. In one years time for high traffic you could expect to use 6 coats in total, three initial coats plus one individual coat every three months. For Low traffic areas, you could expect four coats total in one year, three initial coats and one single coat after six months.
Carpeting is another flooring material that creates large static charges on the people and objects that move across it. Carpets can be treated with a spray-on 50/50 mixture of 18% solid polymer based ESD finish and water. This treatment will adhere to the carpet fibers and give it static dissipative as well as non-triboelectric properties. Even carpets that are rated as anti-static can be treated to bring their high resistance range (> 1011 ohms) down below 109 ohms. Carpets by nature are more difficult to clean and keep clean. The spray treatment can be done after the carpet has been cleaned or vacuumed, two or three times as needed, each time letting it dry for an hour or letting it sit overnight. This treatment will wear due to traffic and cleaning cycles and may require reapplying every three to six months depending on traffic type and frequency. Testing can be done with an ohmmeter using 5lb probes to verify its resistance.
Conclusion: As we look at all the different floor types, floor finish makes a great solution to controlling the static charge generation.
This is a free monthly newsletter, which specializes on issues in static control in the workplace.
Need your own copy? Want to subscribe to this Newsletter? All you or your colleague(s) need to do is simply fill out the subscription form athttp://www.esdsystems.com/forms/esdmail.asp
This Newsletter is never sent unsolicited. To unsubscribe from this mailing, simply reply to this e-mail and include in the subject field the following:UNSUBSCRIBE ESD_Newsletters
Let us know what you think. Tell us what you would like to see in future issues. Want to contribute articles or other related information to our Newsletter? Send your comments to email@example.com