JPH0316661A - Dustless air ionizing device - Google Patents

Abstract

PURPOSE:To suppress the generation of the static electricity in a clean room and to obviate the generation of dust from needle-like electrodes by providing a fine particle depositing device having the needle like electrodes onto an air supplying path to a filter for capturing fine particles and installing the supply port of the air supplying path near the needle-like electrodes of an ion generator. CONSTITUTION:The gas in the clean room 1 is fed from an air suction port 14 of the air supplying path 13 into the ion generator 10 having the needle-like electrodes 16 as the fine particle depositing device to deposit the superfine particles in the gas on the fine particles. The gas deposited with the fine particles is sent to a membrane filter 9, by which the fine particles in the gas are captured. Finally, the gas from which the fine particles are captured is supplied from the supply port 15 near to the needle like electrodes 8 of the ion generator 7. The air of the extremely high cleanliness in which the superfine particles do not exist is supplied near the needle-like electrodes 8 of the ion generator 7. The deposition of the fine particles on the needle-like electrodes 8 is obviated even if the ion generator 7 operates.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an air ionization device used in a clean room, and particularly to a dust-free air ionization device.

[Prior Art] Static electricity has conventionally been generated in clean rooms for semiconductor manufacturing due to the low humidity environment and the tendency of plastic containers for transporting wafers and semiconductor elements to become electrically charged. This static electricity causes dust to adhere to the wafer surface and destroys ICs and semiconductor elements on the wafer, reducing the yield of products. Moreover, with the recent increase in the density of semiconductor devices, ultra-high cleanliness in clean rooms is desired, and the resistance to static electricity of semiconductor devices is also decreasing, making production failures caused by static electricity increasingly problematic. .

Therefore, as a measure to eliminate static electricity in a clean room, a method of neutralizing the electric charge of a charged body using ions has been proposed.

That is, as shown in FIG. 3, the clean room l is
A high-performance filter 5 and an ion generator 2 for feeding clean air are installed on the ceiling. This ion generator 2 generates corona discharge by applying positive and negative high voltages to positive and negative needle electrodes 3, respectively. Then, the air around the needle electrode 3 is ionized into positive and negative ions, the positive and negative ions 4 are transported by a uniform flow from a high-performance filter 5, and the electric charge on the charged body 6 is neutralized with ions 4 of opposite polarity. It is supposed to be done. According to such an ion generator 2,
Even for materials such as semiconductors, which have high electrical resistance and are difficult to ground and leak electric charge, it is possible to reliably neutralize them electrically, preventing the generation of static electricity in a clean room. I can do it.

[Problems to be Solved by the Invention] However, the above conventional techniques have the following problems.

That is, conventionally, in the ion generator 2, dust consisting of fine particles of 0.03 to 0.1 μm has been generated from the needle electrode 3.

Claims (1)

[Scope of Claims] A clean room having an air purifying device that supplies clean air, comprising an ion generator that supplies ions from a discharge electrode to the clean room, an inlet that sucks gas in the clean room, and the ion generator. A gas supply path having a supply port for supplying gas is formed near the discharge electrode, a filter for collecting fine particles in the gas is installed in the gas supply path, and a gas supply path to the filter is further provided with A dust-free air ionization device characterized by the above-mentioned features, in which a particulate precipitation device having a discharge electrode and depositing ultrafine particles in a gas as fine particles is installed.