Press Release Back Number(2005)

Development of the Industry's First "Far-Infrared Plate Heater for Vacuum Furnaces"
- For Use in the Production of Next-Generation Displays -

April 4, 2005
Chubu Electric Power Co., Inc.

In partnership with Noritake Co., Limited, we have developed the industry's first "Far-Infrared Plate Heater for Vacuum Furnaces" for use in the production of TV and computer displays. A far-infrared plate heater that emits far-infrared rays is suitable for the heating of planar objects.

A display production process includes the heat treatment of glass substrates. As heating-temperature variations on the surface may cause unevenness in a screen display, it is important to convey an equal amount of heat to every part of the product. However, with a conventional heating method using infrared lamps or in which the entire furnace wall is heated, it is difficult to evenly heat an entire surface with a large area.

Moreover, next-generation displays such as organic EL (electro-luminescence) displays and FED (field emission displays) use light-emitting materials whose performance decreases when they are exposed to water or oxygen. Therefore, it is necessary to perform heat treatment in a vacuum.

We have developed a heater that can heat substrates evenly in a vacuum. By providing glass seals to create a vacuum for heat treatment and increasing the density of the heating wires around the heater's external surface, from which heat escapes easily, we have made it possible to control temperatures so as to convey heat evenly to every part of the product. We have also succeeded in reducing the thickness of the plate heater to 20 mm. This has enabled the construction of a multistage furnace (a shelf-style furnace in which several heaters and glass substrates are placed alternately) capable of heat-treating twice as many substrates at one time compared to conventional furnaces.

To reduce the time required for the heater to cool after performing heat treatment in a vacuum, we equipped the heater itself with a cooling function. This shortens the production-process time to one-third that of a conventional process. As a result of these features, initial costs can be reduced by approximately half, and operating costs to one-fifth to one-tenth those of conventional systems. This newly developed technology is also applicable to 8th-generation glass substrates (2.2 m x 2.4 m).

This new heater was put on the market today through Noritake Co., Limited. We are planning to exhibit this product at the "15th FPD R&D and Manufacturing Technology Expo & Conference" to be held from April 20 to 22 at Tokyo Big Sight.

Main features of the "Far-Infrared Plate Heater for Vacuum Furnaces"