“Nippon Seisen manufacturer of ultrafine gas filters has developed a 3-layer media for less pressure loss of gas filter, in response to needs for enhancement of productivity, space saving and cost reduction in the production process of semiconductors.

The new filter media employs a sintered intermediate layer of different type in addition to the conventional media, forming a 3-layer structure to reduce pressure loss by about 40% than before. Comparing with other filters of the same shape, you can get a 1.4 times more flow rate. Namely, it enables a flow of 4000 m3/h with the conventional size of 3000 m3/h for bulk gas. Therefore, you can reduce the number of filter, attain compactness and save the cost.

In 1970 Nippon Seisen succeeded in making a micronized fiber of stainless steel. In the field of semiconductor gas filter, a stainless steel fiber with a diameter of 1 to 50 micrometer was formed into short fiber powders, which was sintered to make the media to assure a high trapping efficiency of 9N with 0.0025 micrometer particles.

The company has so far spent a lot of time to attain less pressure loss by such means as the pleating process which increases the surface area of media. The conventional media consisted of two layers, the supporting body and sintered compact to assure accuracy. After two years’ research, the technical team of the company has now made sure of the possibility of further reduction of pressure loss by adding the sintered compact of short fiber powders as an intermediate layer having different diameters of fiber and powder particle.

The company filed a patent application on the technique after assuring the specifications to increase the flowrate without any degradation of trapping efficiency.

Thanks to the supply to foundry requirements and the expanded production of NAND type flash memories from the second half of the year, the company forecasts better business result than expected at the beginning of the term.

Recovery of about 130% is expected in comparison with last year. Regarding a new product, they intend to make a presentation timely prior to planning of investment.”