Application Photo of Surface Resistance Test Kit
A significant increase in the discipline of implementing the fundamentals of ESD control noted in ANSI/ESD S20.20 Foreword, calls for:
- Ground all conductors in the EPA including people
- Remove all insulators from the EPA or use ionizers for process necessary insulators
- Package ESD sensitive items going outside the EPA in packaging that provides electrostatic discharge shielding
We encourage developing a hatred for insulators. The alternatives are:
Remove the insulative item from the EPA
- Substitute the item with an ESD protective version (such as tape, document holders, material handling containers, plastic bottles, etc.)
- Periodically treat insulative surface with a topical antistat
- Neutralize electrostatic charges using ionization
Other ESD Control Items
Other EPA ESD control items to add to the ESD control program might include shelving, mobile equipment (carts), gloves, and/or seating.
Improve Compliance Verification Plan
- Consider greater frequency of internal audits per ESD TR53
- Use of computer data collection system for wrist straps and footwear testing, continuous monitors, and ionizers
- Use of ground continuous monitors for worksurfaces and other ESD elements
- Test ionizers more frequently, consider self monitoring ionizers, consider computer based data collection
- Increased testing using static field meter to verify that automated processes (like auto insertion, tape and reel, etc) are not generating charges above acceptable limits.
Application Photo of Volt Meter and Software in Factory STM97.2 Testing Voltage Charge on Person (Photograph courtesy of TREK, INC.)
- ESD awareness training for all in the EPA or who may come into the EPA including suppliers
- Testing to verify comprehension and training adequacy
- Training on the proper use of test equipment
- Training on proper compliance verification test procedures
Application Photo CD-ROM ESD Training
Just to maintain a company’s current level of quality and reliability may require a substantial improvement in a company’s ESD control program. Now is the time for improvement as ESD sensitivity withstand voltages continue to get lower and companies may soon be handling class 0A HBM items. To combat HBM failures improved personnel grounding is required. For example, heel grounders should be replaced with full coverage foot grounders. However, most failures are CDM. To combat CDM failures, ionization should be added or improved, and conductive surfaces should be covered with dissipative material. In general, disciple should be enhanced implementing ESD control fundamentals, compliance verification testing should be increased, and training should be improved.
From published article “Now is the Time for ESD Control Programs to be Improved” by Fred Tenzer and Gene Felder. See full article at InCompliance Magazine- September 2012
Our thanks to Conformity Magazine Published in December 2004 issue
Accurate process evaluation provides real answers
Provided by the ESD Association
by Stephen Halperin, in collaboration with Ron Gibson
“We need to spend HOW MUCH?”
Recently, a company experienced several large losses due to electrostatic discharge (ESD) and had a very unhappy customer on their hands. The manufacturing vice president now faced a substantial expenditure for new ESD loss prevention equipment. The company’s first step had been to hire an ESD consultant who recommended the purchase of several thousands of dollars in ionization equipment and monitoring instruments for several of the company’s facilities.
The troubled VP read the report several times looking for justification of the expense. However, the report did not define how the recommended equipment would meet the VP’s specific needs. Other than describing how ionization reduced electrostatic charge after it is generated and that the instruments could confirm that a discharge occurred, the report did not identify the actual cause of the process problem. No ESD measurements were described. There were no details related to cause of product loss, device sensitivity concerns, value issues, process and handling details, examination and description of existing controls, or rationale for how the recommended tools would solve the problem in question. The report was clearly based on the consultant observing the process of a single manufacturing environment. In effect, the report made a purchasing recommendation based on a “blanket” opinion, not on facts specific to the needs of the company or their customer. Such an approach typically makes a bad situation worse. While the recommended tools may have been very useful for investigating a process or for solving defined problems, they are expensive Band Aids“ when used in undefined problem situations.
Today’s electronic manufacturing environment demands that minimal ESD controls be in place to provide fundamental protection for electrostatic discharge sensitive (ESDS) devices. When basic ESD controls are employed and losses still occur, manufacturing and quality managers face more difficult problems., In assessing the problem, companies struggle with a variety of major questions concerning a specialized technology, while having minimal information and available skills. To avoid the risk of making the wrong investment decision without solving the initial problem, management needs a way to select and implement the most effective ESD controls that fit their financial situation, solve their specific problems, and provide a respectable return on their investment.
To continue reading Enhancing Profits with Effective ESD Control Click Here
by Rick Cardinale, Bird Electronic
Bird Electronic, founded in 1942 by J. Raymond Bird, soon became a leader in radio frequency instrumentation. Today, Bird also has moved into digital instrumentation test equipment.
With the development of digital instrumentation came the increased need for controls to prevent ESD events. Improving ESD protection has been an ongoing process since the late 1980s. In 1997, the company determined that an automated PCB production line would be installed and that the entire manufacturing area should be protected against ESD.
This decision led to an evaluation of ESD protective flooring. In 1998, 20,000 square feet of conductive floor tile were installed in the main production area. To help brighten the area, white tile was selected. The floor resistance measured less than 1.0 × 10^6 ohms.
A bright, high-gloss appearance was part of the selection criterion for the floor. While the electrical properties were unchanging, by 1999, the floor was starting to dull. It was being maintained like a regular tile floor. No waxes or finishes were used; however, the tile manufacturer did recommend using buffing pads.
After consulting with the tile manufacturer and the installer, maintenance was increased to sweeping clean and damp mopping two times per week and buffing once per month. Monthly floor maintenance was $1,700 per month, a $20,400 annual expenditure.
In late 1999, the maintenance schedule was modified to add more buffing since this was the only way to keep the floor shiny. The floor now was swept and damp mopped weekly and buffed twice per month. The floor was clean and shiny, but the cost went up 41% to $2,400 per month, a $28,800 annual expenditure.
Click Here to continue reading Reducing Floor Maintenance Costs while Improving ESD Performance