JP4565341B2 - Static eliminator - Google Patents

Description

  The present invention relates to a static eliminator, and more particularly, to a static eliminator that removes static electricity generated in a clean room of a semiconductor manufacturing factory.

  In manufacturing factories of semiconductors, especially manufacturing factories of semiconductor devices whose performance and integration are increasing and flat panel displays whose size is increasing, the destruction of devices due to static electricity and the adhesion of dust are problematic. In order to prevent these static electricity disturbances, a static eliminator is used that reduces the generated potential by ionizing and supplying air.

By the way, in recent years, due to the downsizing of the manufacturing apparatus, it has become difficult to secure an installation space necessary for the static eliminator in the manufacturing apparatus. Therefore, in Patent Document 1, an ion generating device is provided at a position away from the manufacturing apparatus, and the ions generated by the ion generating apparatus are transported to a static elimination place, thereby greatly reducing the installation space in the manufacturing apparatus. An ion transport type static eliminator has been proposed. This static eliminator mixes positive ions and negative ions, which are separately conveyed, at the position of the charged body, and sprays a gas with adjusted ion balance on the charged body.
JP 2000-21596 A

  However, the static eliminator of Patent Document 1 has a problem that it cannot cope with static elimination at a plurality of locations. That is, in Patent Document 1, when a plurality of ion gas supply ends are provided in order to perform charge removal at a plurality of locations, a difference occurs in the distance of the ion transport path to each supply end. The inner surface of the ion transport path is positively or negatively charged by friction with air, and each ion receives a force from the inner surface of the transport path to increase or decrease the transport speed. Therefore, there arises a problem that positive and negative ions cannot be controlled to a desired balance.

  Further, Patent Document 1 has a problem that it is difficult to shorten the charge removal time, and the charged object cannot be quickly discharged. That is, Patent Document 1 cannot measure the surface potential of a charged object and cannot supply ions (-ion or + ion) having a reverse polarity with respect to the charge (+ or-) of the charged object. For this reason, it is difficult to shorten the static elimination time, for example, there is a problem that it is difficult to neutralize a charged object conveyed on the line.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a static eliminator that can surely eliminate a plurality of static elimination locations and reduce the static elimination time.

In order to achieve the above object, the invention according to claim 1 is provided at a position of a positive ion generator for ionizing a gas into positive ions, a negative ion generator for ionizing a gas into negative ions, and an object to be neutralized. And at least one supply end unit, a positive ion transport line connecting the positive ion generator and the supply end unit, and transporting a gas ionized by the positive ion generator to the supply end unit, and the negative ions A negative ion transport line that connects the generator and the supply end unit and transports the gas ionized by the negative ion generator to the supply end unit, the supply end unit of the positive ion transport line A positive ion control unit that adjusts the number of positive ions in the gas connected to the tip and a negative ion in the gas connected to the tip of the negative ion transport line Negative ion control unit for adjusting a said positive ion control unit in gas was adjusted positive ion number, a mixing unit which mixes the gas was adjusted negative ion number in the negative ion control unit, a mixing gas And an injection port that injects toward the object to be neutralized.

  According to the first aspect of the present invention, since the positive ion control unit and the negative ion control unit are provided in the supply end unit provided at the position of the object to be neutralized, the gas controlled to have a desired ion balance is injected from the injection port. can do. That is, according to the present invention, even if the number of ions in the positive ion transport line or the negative ion transport line is increased or decreased, the ion balance is controlled by the control unit at the tip of each transport line. Can be sprayed on the object to be discharged, and the object to be discharged can be reliably discharged.

  In addition, according to the first aspect of the present invention, since the ion balance is controlled for each supply end unit, even when a plurality of supply end units are provided, it is possible to reliably perform static elimination at each supply end unit. . Therefore, according to the first aspect of the invention, it is possible to reliably cope with a case where there are a plurality of objects to be discharged.

  Furthermore, according to the first aspect of the present invention, since the positive ion generator and the negative ion generator are connected to the supply end unit via the transport line, the ion generator is disposed at a position away from the supply end. It can be installed even when the installation space around the object to be discharged is small.

  According to a second aspect of the present invention, in the first aspect of the present invention, the positive ion control unit reduces the positive ions in the gas by applying a negative voltage to the wall surface of the tube through which the gas passes. The number of ions is adjusted, and the negative ion control unit adjusts the number of negative ions by reducing the number of negative ions in the gas by applying a positive voltage to the wall surface of the tube through which the gas passes. To do.

  According to the second aspect of the present invention, the number of ions can be adjusted with high accuracy by reducing the number of ions.

  According to a third aspect of the present invention, in the first aspect, the positive ion control unit and the negative ion control unit have a flow rate adjusting means for adjusting a flow rate of gas passing therethrough, and the flow rate is adjusted by the flow rate adjusting means. By adjusting the number of ions, the number of ions contained in the gas is adjusted.

  According to the invention described in claim 3, since the number of ions is adjusted by the gas flow rate, the number of ions can be controlled more quickly. Therefore, the static elimination time can be further shortened.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the supply end unit includes a surface potential meter that measures a surface potential of the object to be discharged, and a measurement by the surface potential meter. And a control means for controlling the positive ion control unit and / or the negative ion control unit based on a value.

  According to the invention described in claim 4, since the surface potential of the object to be discharged is measured and the amount of ions is controlled based on the measured value, the gas blown to the object to be discharged is suitable for the surface potential of the object to be discharged. The ion balance can be controlled, and the object to be discharged can be reliably discharged.

The invention according to claim 5 is the invention according to any one of claims 1 to 4,
The supply end unit controls the positive ion control unit and / or the negative ion control unit based on an ion balance sensor that measures an ion balance in the vicinity of the object to be neutralized, and a measurement value of the ion balance sensor. And means.

  According to the fifth aspect of the present invention, the ion balance in the vicinity of the object to be neutralized is measured, and the amount of ions is controlled based on the measured value. It can spray on a static elimination object and can neutralize the static elimination object reliably. In particular, by combining the invention of claim 5 with the invention of claim 4, it is possible to more reliably remove the charge to be removed.

  According to the present invention, since the ion control unit is provided in the supply end unit provided at the position of the object to be neutralized, the ion balance is not affected by the ion transport line, and the desired ion balance is accurately controlled. The gas thus discharged can be blown against the object to be discharged. Further, according to the present invention, since the supply end unit and the ion generator are connected by the transport line, the ion generator can be installed at a position away from the supply end, and the installation space around the object to be discharged is reduced. Can be installed even in narrow spaces.

  Hereinafter, preferred embodiments of a static eliminator according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 schematically shows the configuration of the static eliminator of the present embodiment. The static eliminator 10 shown in the figure is an apparatus for neutralizing two objects to be neutralized 12X and 12Y. In this embodiment, the number of objects to be neutralized is two, but the number of objects to be neutralized is not limited to this, and may be one or three or more. In addition, the object to be neutralized may be a strip that continuously travels, and in this case as well, neutralization may be performed at one place or at a plurality of places.

  As shown in FIG. 1, the static eliminator 10 mainly includes an ion generator 14 and supply end units 16X and 16Y provided for the respective objects to be neutralized 12X and 12Y.

  The ion generator 14 includes a positive ion generator 14A and a negative ion generator 14B. A gas supply pipe 20A from a clean room (not shown) is connected to the casing 18A of the positive ion generator 14A, and air from the clean room is supplied. Similarly, a gas supply pipe 20B from a clean room (not shown) is connected to the casing 18B of the negative ion generator 14B, and air from the clean room is supplied. The positive ion generator 14A and the negative ion generator 14B include DC high-voltage power supplies 22A and 22B and discharge needles 24A and 24B connected to the DC high-voltage power sources 22A and 22B, respectively. Configured to ionize to negative ions.

  A duct 26A (corresponding to a positive ion transport line) is connected to the positive ion generator 14A, and positive ionized gas is transported through the duct 26A. The duct 26A branches in the middle and is connected to the supply end units 16X and 16Y.

  A duct 26B (corresponding to a negative ion transport line) is connected to the negative ion generator 14B, and negative ionized air is supplied through the duct 26B. The duct 26B branches in the middle and is connected to the supply end units 16X and 16Y.

  The supply end units 16X and 16Y are arranged in the vicinity of the objects to be neutralized 12X and 12Y, and include a positive ion balance control unit 28A (hereinafter referred to as a positive control unit) and a negative ion balance control unit 28B (hereinafter referred to as negative control). Unit). The front end of the duct 26A is connected to the positive control unit 28A, and the front end of the duct 26B is connected to the negative control unit 28B.

  FIG. 2 schematically shows the configuration of the supply end unit 16X. Hereinafter, the supply end unit 16X will be described, but the supply end unit 16Y is configured similarly.

  As shown in FIG. 2, the positive control unit 28A includes a tubular charging unit 30A insulated by an insulator 34A, and a DC power source 32A connected to the charging unit 30A. The direct current power supply 32A applies a negative voltage to the charging unit 30A, and is configured to freely adjust the voltage. The positive control unit 28A extinguishes positive ions of air sent through the duct 26A by bringing them into contact with the tube wall of the charging unit 30A to which a voltage is applied. In addition, the positive control unit 28A adjusts the number of positive ions to be supplied and the number of positive ions to be supplied by increasing or decreasing the surface potential of the charging unit 30A. For example, by increasing the voltage of the charging unit 30A, the number of positive ions that disappear upon contact with the charging unit 30A is increased, and the number of supplied positive ions is decreased. Conversely, by decreasing the voltage of the charging unit 30A, the number of positive ions that disappear upon contact with the charging unit 30A is decreased, and the number of positive ions supplied is increased. Thereby, the number of positive ions passing through the positive control unit 28A can be adjusted, and the supply amount of positive ions to the object to be neutralized 12X can be adjusted.

  Similarly, the negative control unit 28B includes a tubular charging unit 30B insulated by an insulator 34B, and a DC power source 32B connected to the charging unit 30B. The direct current power source 32B is configured to apply a positive voltage to the charging unit 30B, and the voltage can be freely adjusted. The negative control unit 28B extinguishes the negative ions of the air sent through the duct 26B by bringing them into contact with the charging unit 30B to which a voltage is applied. Further, the negative control unit 28B adjusts the number of negative ions to be extinguished by adjusting the surface potential of the charging unit 30B, thereby adjusting the number of negative ions to be supplied. For example, by increasing the voltage of the charging unit 30B, the number of negative ions that disappear in contact with the charging unit 30B is increased, and the number of supplied negative ions is decreased. Conversely, by decreasing the voltage of the charging unit 30B, the number of negative ions that disappear upon contact with the charging unit 30B is decreased, and the number of supplied negative ions is increased. Thereby, the number of negative ions passing through the negative control unit 28B can be adjusted, and the supply amount of negative ions to the object to be neutralized 12X can be adjusted.

  The positive control unit 28A and the negative control unit 28B are connected to the mixing unit 36. Although the configuration of the mixing unit 36 is not particularly limited, the mixing unit 36 is configured to uniformly mix the ionized air from the positive control unit 28A and the ionized air from the negative control unit 28B. A nozzle 38 is provided at the tip of the mixing unit 36. The nozzle 38 is arranged toward the object to be neutralized 12X. Thereby, the ionized air mixed by the mixing unit 36 can be injected toward the to-be-eliminated object 12X.

  A probe 40 that measures the surface potential of the object to be discharged 12X is provided in the vicinity of the object to be discharged 12X. The probe 40 is connected to a surface potential meter 44 in the computing device 42, and the surface potential meter 44 receives a surface potential measurement value signal from the probe 40 and outputs the signal to the computing unit 46. . The computing unit 46 computes an ion balance suitable for the surface potential of the object to be neutralized 12X based on the measured surface potential value. The calculation unit 46 is connected to the positive control unit 28A and the negative control unit 28B, and outputs the calculated result to the positive control unit 28A and the negative control unit 28B. The positive control unit 28A and the negative control unit 28B adjust the number of positive ions and the number of negative ions based on the received calculation signal. Thereby, the air of the ion balance suitable for the surface potential of the to-be-charged object 12X can be sprayed from the nozzle 38 and blown to the to-be-charged object 12X, and the to-be-charged object 12X can be reliably discharged.

  According to the static eliminator 10 configured as described above, the positive control unit 28A and the negative control unit 28B are provided in the supply end unit 16X (or 16Y) provided in the vicinity of the static elimination object 12X (or 12Y). The gas ejected from the nozzle 38 can be reliably adjusted to a desired ion balance. That is, according to the static eliminator 10, even if the number of ions is increased or decreased in the ducts 26A and 26B that are long conveyance paths, the number of ions is adjusted by the positive control unit 28A and the negative control unit 28B provided at the ends of the ducts 26A and 26B. Therefore, it is possible to inject air that is reliably adjusted to a desired ion balance. Therefore, the charge removal object 12X (or 12Y) can be reliably discharged. Further, according to the present embodiment, since the positive control unit 28A and the negative control unit 28B are provided in the supply end units 16X and 16Y, the discharged objects 12X and 12Y are securely attached to the supply end units 16X and 16Y. Static neutralization is possible. Therefore, even in the case of a plurality of objects to be discharged 12X and 12Y, the objects to be discharged 12X and 12Y can be discharged simultaneously.

  Further, according to the present embodiment, since the ion balance is adjusted in the supply end units 16X and 16Y provided in the vicinity of the objects to be neutralized 12X and 12Y, the time required for the neutralization can be shortened. That is, compared with the case where the amount of ions is adjusted by the positive ion generator 14A or the negative ion generator 14B, the static elimination time can be shortened by the transport time in the ducts 26A and 26B.

  Further, according to the present embodiment, the positive control unit 28A and the negative control unit 28B reduce ions by charging the tube walls of the charging units 30A and 30B, so that the number of ions can be controlled with high accuracy. it can.

  Further, according to the present embodiment, the surface potential of the objects 12X and 12Y to be removed is measured by the surface potential meter 44, and the ion balance of the jet air is controlled based on the measured value. Ion balance air suitable for the surface potential of 12Y can be blown onto the objects to be neutralized 12X and 12Y, and the time for static elimination can be further shortened.

  Further, according to the static eliminator 10, since the positive ion generator 14A and the negative ion generator 14B are connected to the supply end units 16X and 16Y by the ducts 26A and 26B, the ion generators 14A and 14B are connected to the supply end units 16X and 16Y. It can arrange | position in the position away from. Therefore, a wide installation space is unnecessary around the objects to be neutralized 12X and 12Y, and the static eliminator 10 of the present embodiment can be installed even in a narrow installation space.

  In the above-described embodiment, the number of ions is controlled by decreasing the number of ions in the positive control unit 28A and the negative control unit 28B. However, the method for controlling the number of ions is not limited to this. As shown in FIG. 3, dampers 48A and 48B may be provided in the positive control unit 28A and the negative control unit 28B, respectively, and the air flow rate supplied to the mixing unit 36 may be adjusted by the dampers 48A and 48B. By adjusting the air flow rate in this way, the number of ions supplied to the mixing unit 36 can be increased or decreased, and the ion balance of air ejected from the nozzle 38 can be adjusted.

  In the above-described embodiment, the ion balance of the air to be blown is adjusted based on the surface potential of the objects to be discharged 12X and 12Y. However, the ion balance around the objects to be discharged 12X and 12Y is measured, and this ion balance is measured. Based on the above, the ion balance of air to be blown may be controlled. FIG. 4 shows an example in which an ion balance sensor 50 is provided in the vicinity of the nozzle 38 and the ion balance of air blown from the nozzle 38 is controlled based on the measured value of the ion balance sensor 50. The ion balance sensor 50 in FIG. 4 is a sensor that measures the positive / negative balance at the supply end, and this ion balance sensor 50 is connected to the detection unit 52 in the arithmetic unit 42. Upon receiving the measurement value signal from the ion balance sensor 50, the detection unit 52 calculates a control amount for adjusting to an appropriate ion balance, and outputs the calculated value to the positive control unit 28A and the negative control unit 28B. . The positive control unit 28A and the negative control unit 28B control the positive and negative ion amounts based on this calculated value. Thereby, the air ejected from the nozzle 38 is controlled to a desired ion balance. As described above, if the air ejected from the nozzle 38 is feedback-controlled, the charge to be removed 12X (or 12Y) can be removed more accurately.

  FIG. 5 is an example in which the ion balance of air ejected from the nozzle 38 is adjusted based on both the surface potential of the object 12X (or 12Y) and the ion balance around the object 12X (or 12Y). . The probe 40 shown in the figure is provided in the vicinity of the object to be discharged 12X, and the surface potential of the object to be discharged 12X is measured by a surface potential meter 44 connected to the probe 40. The ion balance sensor 50 is provided in the vicinity of the nozzle 38, and the ion balance of the air ejected from the nozzle 38 is measured by the detection unit 52 connected to the ion balance sensor 50. The surface potential meter 44 and the detection unit 52 are connected to the calculation unit 46, and the calculation unit 46 has an ion balance suitable for the surface potential of the object 12 </ b> X (or 12 </ b> Y) based on the measurement value of the surface potential meter 44. The calculation result is output to the positive control unit 28A and the negative control unit 28B, and control is performed so that air having a desired ion balance is ejected from the nozzle 38. On the other hand, the calculation unit 46 feedback-controls the positive control unit 28A and the negative control unit 28B based on the measurement value of the ion balance sensor 50 so that the jet air from the nozzle 38 has a desired ion balance. Thereby, the air of ion balance adjusted with high accuracy with respect to the surface potential of the object to be discharged 12X (or 12Y) can be blown to the object to be discharged 12X (or 12Y), and the object to be discharged 12X (or 12Y). Can be quickly and accurately performed.

  In the above-described embodiment, both the positive control unit 28A and the negative control unit 28B are provided in the supply end units 16X and 16Y to adjust both the positive ion amount and the negative ion amount. Instead, one of the positive control unit 28A and the negative control unit 28B may be provided to adjust one of the positive ion amount and the negative ion amount.

The figure which shows typically the structure of the static elimination apparatus which concerns on this invention The figure which shows the supply end unit of FIG. The figure which shows a control unit different from FIG. The figure which shows the supply end unit which has a control means different from FIG. The figure which shows the supply end unit which has a control means different from FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Static elimination apparatus, 12X, 12Y ... Electrostatic discharge object, 14 ... Ion supply part, 14A ... Positive ion generator, 14B ... Negative ion generator, 16X, 16Y ... Supply end unit, 26A, 26B ... Duct, 28A ... Positive Ion control unit, 28B ... negative ion control unit, 36 ... mixing unit, 38 ... nozzle, 40 ... probe, 42 ... computing device, 44 ... surface potential meter, 46 ... computing unit, 50 ... ion balance sensor, 52 ... detection unit

Claims (5)

A positive ion generator for ionizing gas into positive ions;
A negative ion generator for ionizing gas into negative ions;
At least one supply end unit provided at the position of the object to be neutralized;
A positive ion transport line for connecting the positive ion generator and the supply end unit, and transporting a gas ionized by the positive ion generator to the supply end unit;
A negative ion transport line for connecting the negative ion generator and the supply end unit, and transporting a gas ionized by the negative ion generator to the supply end unit;
The supply end unit comprises:
A positive ion control unit that is connected to the tip of the positive ion transport line and adjusts the number of positive ions in the gas;
A negative ion control unit that is connected to a tip of the negative ion transport line and adjusts the number of negative ions in the gas;
A mixing unit for mixing the gas was adjusted positive ions number in the positive ion control unit, and a gas regulating negative ion number in the negative ion control unit,
An injection port for injecting the mixed gas toward the object to be discharged;
A static eliminator characterized by comprising: The positive ion control unit adjusts the number of positive ions by reducing the positive ions in the gas by applying a negative voltage to the wall of the tube through which the gas passes,
The negative ion control unit adjusts the number of negative ions by reducing a negative ion in the gas by applying a positive voltage to a wall surface of a tube through which the gas passes. Static neutralizer.   The positive ion control unit and the negative ion control unit have flow rate adjusting means for adjusting a flow rate of gas passing therethrough, and adjusting the number of ions contained in the gas by adjusting the flow rate with the flow rate adjusting means. The static eliminator according to claim 1. The supply end unit is
A surface potential meter for measuring the surface potential of the object to be neutralized;
Control means for controlling the positive ion control unit and / or the negative ion control unit based on the measured value of the surface potential meter;
The static eliminator according to claim 1, comprising: The supply end unit is
An ion balance sensor for measuring an ion balance in the vicinity of the object to be neutralized;
Control means for controlling the positive ion control unit and / or the negative ion control unit based on the measured value of the ion balance sensor;
5. The static eliminator according to claim 1, comprising:

Images