New Way® Air Bearings Launches Modular Conveyor Air Bearings to Support Flat Panel Display Manufacturing Processes
Aston, Pennsylvania, USA, May 24, 2005 – New Way® Air Bearings has introduced a line of three modular air bearing products specifically designed to meet the glass-handling requirements of the Flat Panel Display (FPD) manufacturing process. This line includes flat panel conveyor air bearings for floating glass in high speed applications, low airflow applications, and for applications under or near precision processes.
With Gen 6, 7, and 8 glass sizes, machine design challenges increase exponentially, creating significant obstacles to a simple scaling of Gen 4 and Gen 5 machines. The gantry width necessary to span these sizes – a Gen 7 gantry can exceed 2m in width – increases moving mass significantly, and requires extensive engineering to produce the stiff structures necessary to maintain settling times and system resonance at acceptable levels.
Further, a unit glass area of 4 m2 behaves quite differently than one of 1m2. With the more significant economic loss due to damage of panels this size, FPD manufacturers are demanding non-contact handling solutions. Wheels and rollers no longer enable world-class manufacturing operations. Nor will they allow manufacturers to meet ever-increasing yield and throughput improvement demands.
“Our Porous Media Air Bearing Solutions provide significant advantages for FPD manufacturing over conventional contact bearings or orifice-based air bearings, especially for coating or AOI applications in Gen-5 or higher manufacturing lines,” said Tim Claffey, New Way Vice President, Sales.
In their most basic form, New Way® Conveyor Air Bearings offer a superior, non-contact stationary glass chuck solution which also provides for lower initial costs and reduced operating expenditures. Segmented design allows a variety of array configuration alternatives to meet a wide range of machine designs. And discrete, independent mechanical adjustability allows for easier set-up and commissioning.
New Way® porous media technology provides for reduced external Clean Dry Air (CDA) consumption and virtually eliminates the disruptive air flow sources innate in extruded products using simple orifices or plate-and-nozzle systems. This is especially critical in a cleanroom environment where, unlike orifice applications which allow particles to flow unimpeded, New Way Conveyor Air Bearings can also act as a stop-gap filter, trapping any particles which may have escaped the filter system.
Further, New Way Conveyor Air Bearings provide greater stiffness, resulting in a more consistent fly height, and a reduction or elimination of the damage caused by the glass contacting the chuck. This, combined with the use of vacuum pre-loaded sections, allow these bearings to pull the glass into a flatter plane, reducing drooping or curling after coating applications.
“The superior stiffness of our air bearings provides for faster settling time and higher yield, without the scratching or breakage typical of competitive systems,” Claffey continued. “They also enable a higher process velocity, reliability and control, for significantly greater throughput. Yet operating costs are low, comparatively, due to the nature and function of the New Way porous media solution. What’s more, the larger the glass size, the bigger the advantage.”
Finally, the benefits defined reflect those for moving gantry applications. But one of the most significant benefits of New Way Conveyor Air Bearings is that they also offer new flat panel production options. They also provide manufacturers with the flexibility of designing machines with a fixed gantry and moving glass, for a continuous, inline process.
New Way High Speed FPD Conveyor Air Bearing
For improved non-contact control of Flat Panel Display glass at high manufacturing process speeds, New Way has developed a High Speed FPD Conveyor Air Bearing.
“As designers have tried to reduce or eliminate damage caused by the substrate contacting the chuck, they have increased the fly height, but the problem remains,” noted Drew Devitt, New Way Chairman and Chief Technology Officer. “That’s because a large air gap acts like an undamped spring, allowing waves to propagate, and increasing the probability of contact with the air chuck, resulting in scratches or glass fracture.”
“Although it might be counterintuitive, New Way has found that a lower air gap actually reduces the chance for contact, since the stiffness of an air film is inversely proportional to the air gap,” said Devitt. “Air gaps should be less than 50 microns for the best control of FPD glass. With our technology, that smaller air gap significantly reduces the probability of contact with the bearing surface, and the resulting scratches or glass fracture.”
A large vacuum area results in a smaller air gap, providing higher stiffness and improved damping. The large, attractive forces give excellent flattening ability for more reliable glass control. This, combined with the constant low pressure at the leading edge of the glass, prevents it from lifting off the conveyor and ‘sailing’ at high speeds.
New Way Low Airflow FPD Conveyor Air Bearing
New Way’s new Low Flow FPD Conveyor Air Bearing offers non-contact control optimized for low airflow requirements.
“The problem with high fly-heights – of greater than 50 microns – is that they typically result in low air film stiffness,” Devitt said. “That means you have less control, unless they’re supported with correspondingly high pressures and air flows. Either way, it’s going to cost you.”
To add control while optimizing air flow requirements, New Way applied its proprietary porous media solution. By plumbing most of the porous media face with low pressure air, and utilizing high pressure air only around the vacuum holes, flow requirements are greatly reduced.
The periodic high pressure areas, preloaded by the vacuum, create high stiffness points which stabilize the glass dynamics even at high air gaps and low air consumption. Because the pressurized air bleeds out of the entire bearing face, it provides a high margin of safety against glass touch-down.
Porous Media Precision Chucks
For non-contact control of FPD glass under or near precision processing applications, New Way introduced a Porous Media Precision Chuck. This chuck provides a much higher level of precision, stiffness, and damping than traditional air conveyors.
“Our Porous Media Precision Chucks are designed so that, with air pressure on, the flow through a vacuum hole is the same whether there is glass over it or not,” Devitt said. “As simple as this solution is, it also offers a number of additional advantages. For example, as the glass moves on, over and off of the chuck, the vacuum pressures and air gaps remain the same.”
The net result is that by moving the glass over an array of New Way® Precision Chucks, large, costly, substrate-sized vacuum chucks can eliminated. Further, the high pressure air exiting the gap prevents back-side damage to the glass or contamination by the bearing surface.
The Advantages of Porous Media
New Way’s modular air bearing products are inexpensive, robust, and easy to use. Unlike conventional orifice air bearings, New Way® Porous Media controls the airflow across the entire bearing surface through millions of holes in the material. More consistent air pressure distribution provides for superior performance, and the bearings still fly even after severe surface damage.
Porous media technology has been in use for 15 years in precision applications such as coordinate measuring machines, precision machine tools, and test equipment. One advantage is that the bearing does not damage the surface it runs on should the air supply be inadvertently lost. Having no friction or wear problems, and with no lubrication requirements, air bearings are ideal for applications in demanding environments that wreak havoc on traditional contact bearings.
For more sophisticated applications like the FPD marketplace, New Way Air Bearings are approved for use in Class-10 Clean Rooms, where the constant flow of air helps keep the dust and particles found even in that environment away from the bearing surface.
FPD Conveyor Bearings Part of a Broader Line of Standard New Way Air Bearing Products
These new FPD Conveyor Air Bearings are the latest additions to the complete line of porous media air bearing products from New Way Air Bearings, including flat air bearings, cylindrical air bushings, vacuum preloaded air bearings, radial air bearings, and air bearing stages.
New Way delivers total air bearing solutions starting at their website http://www.newwayairbearings.com/, which includes the specifications for the full product range, design and installation guides, mounting hardware, air specifications, technical support, and a full range of accessories.
For more information, contact Tim Claffey, VP Sales at 610.494.6700.
New Way Air Bearings
New Way® Air Bearings, Inc. is the market leader in the design and manufacture of modular air bearings and is the recognized provider of porous media air bearing solutions. Founded in 1994, New Way is located in Aston, Pennsylvania, USA, just fifteen minutes from Philadelphia International Airport.
High-resolution images of the New Way Flat Panel Display Conveyor Air Bearing products referenced in this release are available for use by the media. Contact Michael Wright, Director of Marketing, New Way Air Bearings at 610.364.3453 or by email at firstname.lastname@example.org.