Sanyo Electric Co., Ltd.

Hirofumi Iinuma

Motoyuki Tsuihiji

Masahiro Iseki

Hiroyuki Umezawa

Tsuyoshi Rakuma

Mineo Ikematsu

Daizo Takaoka

Takeshi Kanai

Atuyumi Ishikawa

Object of the preferred embodiment is to remove sol-form microparticles and nitrogen components contained in CMP wastewater. Sol-form microparticle components contained in CMP wastewater are removed by a filtration treatment using a filter device, having a gel-form second filter. Also, nitrogen components in the CMP wastewater are removed by an electrochemical treatment using electrode. The filtration treatment and the electrochemical treatment can be carried out in individual tanks or can be carried out in the same tank. By performing the filtration treatment and the electrochemical treatment in the same tank, a space-saving water treatment device can be provided.

Water treatment device and water treatment method using the same

A filtering method is directed to a wastewater of CMP process, which includes sub-micrometer particles suspended as colloid. The wastewater is filtered by a gel membrane formed on a surface of plastic filter. A coagulant or a pH adjuster is added to the wastewater so that the sub-micrometer particles are coagulated to form the gel membrane.

Filtering method of a colloidal solution

Techniques for recycling waste particles may include solidifying particles, which were generated by machining a crystal ingot into a wafer or by machining a semiconductor wafer, into a cake, and melting the cake, for example, into an ingot.

Method of fabricating a semiconductor device

A filtration device is provided in which wastewater, in the form of a colloidal solution containing microparticles, is guided to tank, circulated, and filtrated using a second filter. The device includes a gel film that is formed by suction on the surface of a first filter. The suction pressure in this process is made extremely weak to maintain the filtration capacity while extending intervals prior to clogging of second filter . Furthermore, a filtration device is realized with which the gel film of second filter that becomes adsorbed onto the surface of first filter can be separated readily by stopping the suction and filtration can be continued again thereafter.

Filtration device

Waste water generated by processing a semiconductor is filtered to be cleaned. Removable matters trapped by a first filter film are used as a second filter film. Filtering capciity is maintained by applying an external force such as bubbles to the second filter film. When removable matters are mixed with the filtered water, the filtered water is recirculated again to the tank in which the waste water is stored, and after it is checked that a desired inclusion rate has been reached filtration is started again.

A fluid is filtered by first preparing a filter which includes a base filter and solid substances provided on the base filter, such that the solid substances differ from objects within the fluid to be filtered that are removed by the filter. The objects of filtration are filtered by supplying the fluid to the filter. During filtration, a force is applied to the filter to move the solid substances and objects deposited on the filter. The application of such force thus allows continuous filtration through the filter. The force can take the form of application of rising bubbles, a mechanical vibration or sonic waves to the filter. The filtration method is useful in processing fluid waste from mechanical processes, such as CMP steps.

Method of filtering a fluid

Removables trapped by a first filter film are used as a second filter film and clogging of the first filter film is prevented, and an external force such as bubbles is applied to the second filter film to maintain filtering capacity. And when removables are mixed with the filtered water, the filtered water is recirculated again to the tank in which the wastewater is stored, and after it is checked that a desired inclusion rate has been reached filtration is started again.

According to the apparatus, removables trapped by a first filter film are used as a second filter film , and clogging of the first filter film is prevented, and an external force such as bubbles is applied to the second filter film to maintain filtering capacity. And when removables are mixed with the filtered water, the filtered water is recirculated again to the tank in which the wastewater is stored, and after it is checked that a desired inclusion rate has been reached filtration is started again.

Apparatus for filtering a fluid

This method provide a method for fabricating a semiconductor device in which waste water generated by a step of processing a semiconductor is filtered to be clean. In the method, removables,trapped by a first filter film,are used as a second filter film,, and clogging of the first filter film,is prevented, and an external force such as bubbles is applied to the second filter film,to maintain filtering capacity. And when removables are mixed with the filtered water, the filtered water is recirculated again to the tank in which the waste water is stored, and after it is checked that a desired inclusion rate has been reached filtration is started again.

A heat exchanger having an improved and substantially uniform heat exchange efficiency, provided with a plurality of plate fins each of which has tube inserting bores arranged in a staggered manner, and heat transfer tubes inserted through these bores, a plurality of each of the fins which are between the tubes being cut doubly to a small width and raised so as to form louver elements so that the louver elements cross a flow of the air stream. The root portions of the louver elements are positioned so as to surround the inserted portions of the tubes, the louver elements consisting of central louver elements formed on both sides of the center line of the row of the tubes, and a plurality of rows of divisional louver elements formed on both sides of the central louver elements with base portions left on the regions of the fin which are on a line crossing the mentioned center line, and the length of the divisional louver elements in the outside rows farthest away from the center line is set substantially equal to the distance between the louver elements in each row and the length of the divisional louver elements in the inside rows.

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Oizumi-machi, Japan

Hirofumi Iinuma