22-05-2019 | By Nnamdi Anyadike
The use of air ionisers to eliminate the build-up of static charges on non-conductors in the workplace or at home is growing as electronic components become ever more static electricity-sensitive. Air ionisers work by flooding the atmosphere with positive and negative ions. These ions are attracted to ions of the opposite polarity on a charged surface. And as a result, the static electricity that has built up on products, equipment and surfaces is neutralised. One example where specialised industrial ionisers are in use is in the semi-conductor industry.
Another example is in the print trade where friction between the rollers and paper generates static, causing the paper to cling and not move correctly through the machine. Here an ‘ionising bar’ is often fitted just above the rollers to ‘spray’ them with the appropriate polarity of ions. Key supplier companies include: Panasonic, SMC, Shanghai Anping Static Technology Co. Ltd, Haug Biel AG, ElectroStatics, Inc., Gordon Brush Mfg. Co., Inc., Meech Static Eliminators, Nex Flow Air Products Corp. and Electro Static Technology.
SMC Germany GmbH recently announced the launch of its new ioniser series for the removal of static electricity. The IZN10E ioniser series weighs in at 80 grams, which is 40 grams less than its predecessor IZN10 series. It is also up to 10 mm shorter. Their low weight, shorter dimensions and narrow design make the IZN10E series ideal for applications where space is at a premium. The series’ customisation versatility is also a major strength. Tobias Hartherz, Product Management SMC Germany explained, "Existing connection cables and also the plug connections are compatible despite the reduced dimensions and can therefore be used without any problems even during retrofitting." He continued, “If you want to reduce static electricity over long distances up to a maximum of 500 mm, you can use the variant with high flow. These models can very well hold the ion balance in the range of ± 15 volts.”
The Japanese company Panasonic has updated its line of static sensing and reduction sensors. The EF-S1 series of sensors, formerly Sunx, are high-frequency AC ionisers that offer extremely fast charge reduction by emitting a highly balanced ion stream directly to sensitive parts before static discharge has a chance to damage them. The EF-S1HS electrostatic sensor head continuously monitors static, even while the production lines are running. The company said, “Static electricity is not visible, so measurement of surface potentials, while the production line is running, using the EF-S1 series provides a new way to assess its levels accurately so that it can be constantly managed.” The devices come with an easy-to-read 2-colour (red and green) dual display where current values and threshold values can be viewed at a glance. The sensor head weighs 90gramms allowing for ease of installation.
A major supplier of ion bar static eliminators to world markets is the Shanghai based Anping Static Technology Co. This Hi-Tech enterprise, specialising in researching and manufacturing DC ionisers, was set up in 1999. And its 20W AP-AB1108 ion bar static eliminator is now widely used in electronics, plastics, chemicals, printing, textiles, optical and other industries. The company is also on the council of the China Electronics Industry Association Anti-static Equipment Branch where it is developing more advanced products.
In the US, ElectroStatics, Inc. offers a range of static control equipment and contamination controls, ionisation equipment, instrumentation for static measuring and testing, static bars, power supplies, converting accessories and more. Gordon Brush Mfg. Co., Inc. also supplies a range of ESD and clean room products. Meanwhile, Meech Static Eliminators, which claims to have pioneered the industrial use of Pulsed DC technology for static control, now has over 4,500 systems in use in the plastics, converting, printing and packaging industries. Nex Flow’s line of air moving, air amplification, air conveying and air cooling products also includes static control technology while Electro Static Technology™ designs and manufactures custom OEM configured static dissipative brushes for a broad range of applications such as printers, copiers, graphic arts and packaging equipment.
The US based independent trade association, the Electrostatic Discharge Association (ESDA), offers device stress testing certification for product upgrades. Arnold Steinman, a consultant in electrostatics, static charge control, and ionization and an ESDA certified ESD programme manager said, “Today’s 300 mm wafers are expected to be replaced with 450 mm wafers over the next decade. In disk drives, we have seen ever increasing storage density in smaller and smaller packages.” In manufacturing, the smaller device features mean that smaller particles have the potential to cause defects, as they are more easily attracted to charged surfaces.
Technology changes have made the control of static charge levels on and around the product critically important and this trend is likely to increase. Smaller device geometries and the magneto-resistive (MR) heads of disk drives require control of static charge to very low levels. An ESD Technology Roadmap provided by the ESD Association has now been published giving insights into device technology trends and likely future ESD sensitivity.