JP2009059631A - Static eliminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a static eliminator which can destaticize suitably, while it is prevented that an object to be destaticized becomes a nonconforming item due to reverse-charge. <P>SOLUTION: In a console 33, a screen capable of selecting one of three-staged allowable charged voltage levels, one of three-staged distance levels, or with or without of a nozzle 18 is displayed, and an allowable charged voltage level according to an allowable charged voltage of the object W to be destaticized, a distance level corresponding to a distance L between the object W to be destaticized and a discharge needle 17, or with or without of the nozzle 18 are made to be selected. A control part 31 reads out a frequency associated with combination of the allowable charged voltage level, of the distance level, and of with or without of the nozzle 18 selected in the console 33 from a memory part 34, and the frequency is made to be memorized as the command frequency in a work memory 32 in the control part 31. Then, as for the control part 31, high voltages of positive polarity and high voltages of negative polarity are alternately applied to the discharge needle 17 by the command frequency memorized in the work memory 32. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a static eliminator.

Conventionally, positive and negative ions are alternately generated by applying a positive and negative high voltage at a predetermined frequency to the discharge needle, and these positive and negative ions are irradiated to a static elimination target such as an integrated circuit, etc. There is a static elimination device that electrically neutralizes the static elimination object. By the way, when the distance between the static elimination object and the discharge needle is short, the ions quickly reach the static elimination object. Therefore, if the period of irradiating ions of the same polarity is long (frequency is low), the static elimination object is There is a risk of electrostatic discharge due to charging (reverse charging) to the polarity of ions irradiated from the static eliminator. On the other hand, when the distance between the static elimination object and the discharge needle is long, it takes time for the ions to reach the static elimination object, so it is necessary to irradiate ions of the same polarity for a long time. Therefore, in the static eliminator described in Patent Document 1, the frequency is set high when the distance between the static elimination object and the discharge needle is short, and when the distance between the static elimination object and the discharge needle is long. By setting it low, the static elimination object is suitably neutralized.
JP 2000-58290 A

  By the way, the allowable voltage (the maximum voltage at which the static elimination object is not damaged by electrostatic discharge caused by charging or the voltage such as the voltage determined so that the dust adsorbed on the static elimination object by charging does not exceed a predetermined amount) is Depending on the material, size, etc., it differs for each static elimination object. For this reason, a static elimination object with a low permissible voltage may be damaged due to, for example, electrostatic discharge caused by reverse charging, or a circuit formed on the static elimination object may be short-circuited due to adhesion of dust, etc. It is easy to become. However, in the static eliminator described in Patent Document 1, the frequency is set according to the distance between the static elimination object and the discharge needle. Therefore, when the distance between the static elimination object and the discharge needle is long, the frequency is set. Is set to be low, and there is a risk that a static elimination object with a small allowable charging voltage may become a nonconforming product due to electrostatic discharge due to reverse charging.

  Therefore, it is conceivable that the frequency is set to be high by arranging the static elimination device and the static elimination object so that the distance between the static elimination object and the discharge needle becomes short. However, depending on the use environment of the user, the static eliminator and the static eliminator cannot be arranged so that the distance between the static eliminator and the discharge needle is shortened.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a static eliminator capable of suitably eliminating static electricity while preventing the static elimination object from becoming an incompatible product due to reverse charging. is there.

  In order to achieve the above object, the invention described in claim 1 includes a discharge needle, a high voltage generation circuit for generating a positive high voltage and a negative high voltage, the positive high voltage and the negative electrode. In a static eliminator comprising a control means for alternately applying a high voltage with a predetermined command frequency to the discharge needle and a frequency setting means for setting the command frequency, a plurality of preset The first selection means capable of selecting one allowable band voltage level according to the allowable band voltage of the object to be neutralized from the allowable band voltage levels, and frequencies respectively associated with the plurality of allowable band voltage levels. Stored in the storage means, wherein the frequency setting means reads out a frequency associated with the allowable band voltage level selected in the first selection means from the storage means, and reads the frequency into the command frequency. As It was to be constant.

  According to this configuration, in the first selection means, one allowable band voltage level corresponding to the allowable band voltage of the static elimination object is selected from the plurality of allowable band voltage levels. Then, the frequency associated with the allowable band voltage level is read from the storage means by the frequency setting means, and the frequency is set as the command frequency. In the storage means, for example, a higher frequency is associated and stored as the allowable band voltage level is smaller. Therefore, since the higher frequency is set as the command frequency as the allowable band voltage of the static elimination object is smaller, the voltage generated in the static elimination object due to reverse charging can be kept low. Therefore, even a static elimination object with a low allowable voltage is prevented from becoming a non-conforming product due to electrostatic discharge or the like, and the static elimination is suitably performed.

  According to a second aspect of the present invention, in the static eliminator according to the first aspect, one distance level corresponding to a distance between the static elimination object and the discharge needle is selected from a plurality of preset distance levels. Second selectable selectable means, wherein the storage means stores frequencies respectively associated with the combinations of the plurality of permissible voltage levels and the plurality of distance levels, and the frequency setting means The frequency associated with the combination of the allowable band voltage level selected by the first selection means and the distance level selected by the second selection means is read from the storage means, and the frequency is calculated. The command frequency is set.

  According to this configuration, the frequency setting means causes the frequency associated with the combination of the allowable band voltage level selected by the first selection means and the distance level selected by the second selection means to be stored from the storage means. It is read out and the frequency is set as the command frequency. Then, the storage means has, for example, a frequency obtained by adding a frequency corresponding to the distance level to a frequency associated with each allowable band voltage level so as to increase as the allowable band voltage level decreases. Each level is associated with each combination. Also, the greater the distance level, the greater the frequency added to the frequency associated with the allowable band voltage level. For this reason, when the distance between the static elimination object and the discharge needle is short, the command frequency is set higher, so that the voltage generated in the static elimination object due to reverse charging can be kept lower. It is more reliably suppressed that the product becomes a non-conforming product, and the static elimination is suitably performed.

  According to a third aspect of the present invention, in the static eliminator according to the second aspect, the ion generated by the discharge needle is supplied to the static eliminator and the nozzle is detachable, and the nozzle is provided in the static eliminator. And a third selection means capable of selecting whether or not the plurality of allowable voltage levels, the plurality of distance levels, and the presence or absence of the nozzle. The frequencies associated with each other are stored, and the frequency setting means includes the allowable band voltage level selected by the first selection means, the distance level selected by the second selection means, and the first The frequency associated with the combination with the presence / absence of the nozzle selected by the selection unit is read from the storage unit, and the frequency is set as the command frequency. It was.

  When the nozzle is provided, if the nozzle is charged, ions generated by the discharge needle disappear by discharging the nozzle, so that the charge cannot be efficiently removed. Therefore, when a nozzle is provided, it is necessary to increase the command frequency so that the nozzle is not charged. In this regard, according to the configuration, the frequency setting means selects the allowable band voltage level selected by the first selection means, the distance level selected by the second selection means, and the third selection means. The frequency associated with the combination of the presence or absence of the nozzles is read from the storage means, and the frequency is set as the command frequency. The storage means, for example, a frequency obtained by adding a frequency according to the distance level and a frequency according to the presence or absence of the nozzle to a frequency associated with each allowable band voltage level so as to increase as the allowable band voltage level decreases. Are associated with each combination of the allowable voltage level, the distance level, and the presence or absence of a nozzle. In addition, when the nozzle is provided in the static eliminator, the frequency according to the presence or absence of the nozzle is increased based on the selected allowable voltage level and distance level, and the nozzle is provided in the static eliminator. If not, the frequency based on the selected allowable voltage level and the distance level is not changed. Therefore, when the nozzle is provided in the static eliminator, the frequency setting means has the nozzle provided in the static eliminator in order to set a frequency higher than the frequency based on the selected allowable band voltage level and the distance level as the command frequency. Even if it is a case, the ion produced | generated with the discharge needle will not lose | disappear by discharging a nozzle, but the charge removal object is discharged efficiently.

  ADVANTAGE OF THE INVENTION According to this invention, the static elimination apparatus which can be neutralized suitably can be provided, preventing that the static elimination object becomes a nonconforming product by reverse charging.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
FIG. 1 is a block circuit diagram of the static eliminator 11. The static eliminator 11 is used to electrically neutralize the static elimination target object W by irradiating the static elimination target object W such as an integrated circuit with positive and negative ions. The AC power supply 12 of the static eliminator 11 is connected to a positive high voltage generation circuit 14 that generates a positive high voltage via a low voltage side switch 13a, and generates a negative high voltage via a low voltage side switch 13b. The negative high voltage generation circuit 15 is connected.

  The positive high voltage generation circuit 14 includes a transformer 21 connected to the low voltage side switch 13 a and a voltage doubler rectifier circuit 22 connected to the transformer 21. The transformer 21 boosts the voltage applied from the AC power supply 12 to a voltage corresponding to the turn ratio and outputs the boosted voltage to the voltage doubler rectifier circuit 22. The voltage doubler rectifier circuit 22 rectifies the voltage boosted by the transformer 21 into a positive DC voltage and outputs a voltage with a predetermined magnification (for example, twice). In this way, the positive high voltage generation circuit 14 outputs a positive high voltage. Similarly, the negative high voltage generation circuit 15 includes a transformer 23 connected to the low-voltage side switch 13b and a voltage doubler rectifier circuit 24 connected to the transformer 23. The negative high voltage generation circuit 15 boosts the voltage applied by the AC power supply 12 by the transformer 23 and outputs the boosted voltage to the voltage doubler rectifier circuit 24. By setting the voltage to the negative magnification, a negative high voltage is output. In the present embodiment, the voltage doubler rectifier circuits 22 and 24 are configured as so-called Cockcroft-Walton type voltage doubler rectifier circuits.

  The output terminal of the positive high voltage generation circuit 14 is connected to the discharge needle 17 via the high voltage side switch 16a, and the output terminal of the negative high voltage generation circuit 15 is connected to the discharge needle 17 via the high voltage side switch 16b. ing. A cylindrical nozzle 18 is detachably provided on the distal end side of the discharge needle 17. When the high-voltage side switch 16 a is turned on, a positive high voltage generated by the positive high voltage generation circuit 14 is applied to the discharge needle 17, and positive ions are generated in the discharge needle 17. Further, when the high-voltage side switch 16 b is turned on, the negative high voltage generated by the negative high voltage generation circuit 15 is applied to the discharge needle 17, and negative ions are generated in the discharge needle 17. And the ion produced | generated in the discharge needle 17 is irradiated to the static elimination object W through the nozzle 18. FIG. Note that the high-voltage side switches 16a and 16b are configured by field-effect transistors whose breakdown voltage is increased by including silicon carbide as a semiconductor component, for example, so that high voltage switching can be performed at high speed. .

  The low-voltage side switches 13a and 13b and the high-voltage side switches 16a and 16b are connected to a control unit 31 as control means and frequency setting means. The low voltage side switch 13a and the high voltage side switch 16a, and the low voltage side switch 13b and the high voltage side switch 16b are complementarily turned on and off by the control signal S from the control unit 31. For example, when the control signal S of the control unit 31 is at the H level, the low-voltage side switch 13a and the high-voltage side switch 16a are turned on, and the low-voltage side switch 13b and the high-voltage side switch 16b are turned off. High voltage is applied. On the other hand, when the control signal S of the control unit 31 is at the L level, the low pressure side switch 13a and the high voltage side switch 16a are turned off, and the low pressure side switch 13b and the high voltage side switch 16b are turned on. High voltage is applied.

  Further, the control unit 31 is provided with a work memory 32 composed of a volatile memory. The work memory 32 stores a cycle (hereinafter referred to as a command frequency) for switching the output level of the control signal S, that is, for switching on and off the low-pressure switches 13a and 13b and the high-voltage switches 16a and 16b. Then, the control unit 31 switches on / off of the low-voltage side switches 13a and 13b and the high-voltage side switches 16a and 16b according to the command frequency, so that a positive high voltage and a negative high voltage are supplied to the discharge needle 17. On the other hand, it is applied alternately at the command frequency.

  Furthermore, the control unit 31 is connected with a console 33 as first, second and third selection means and a storage unit 34 as storage means including a nonvolatile memory. The console 33 includes, for example, a display screen composed of a liquid crystal display or the like, and a touch panel arranged on the surface of the display screen. The console 33 displays characters on the display screen according to a signal from the control unit 31, and the characters, etc. Is detected and a signal is output to the control unit 31.

  In the storage unit 34, for example, allowable band voltage levels (allowable band voltage levels “high”, “medium”, and “small”) hierarchized in three stages according to the allowable band voltage of the static elimination object W, and static elimination A distance level (distance level “large”, “medium”, “small”) hierarchized in three stages according to the distance L between the object W and the discharge needle 17 is stored. Further, the storage unit 34 stores frequencies associated with respective combinations of allowable band voltage levels and distance levels. Specifically, as shown in FIG. 2, the storage unit 34 has a frequency and nozzle corresponding to the distance level to the frequency associated with each allowable band voltage level so as to increase as the allowable band voltage level decreases. A frequency obtained by adding a frequency corresponding to the presence / absence of 18 is associated with each combination of the allowable band voltage level, the distance level, and the presence / absence of the nozzle 18. The frequency according to the distance level is higher as the distance level is smaller, and is 0 when the distance level is the maximum (in this embodiment, the distance level is “large”), and is associated with the allowable band voltage level. A frequency lower than the specified frequency is not set as the command frequency. In addition, when the nozzle 18 is provided in the static eliminator 11, the frequency corresponding to the presence or absence of the nozzle 18 is increased based on the selected allowable voltage level and distance level. 11 is not changed, the frequency based on the selected allowable band voltage level and the distance level is not changed. On the console 33, three levels of permissible voltage levels, three levels of distance levels, and the presence / absence of the nozzle 18 are displayed in a selectable manner.

Next, the setting of the command frequency will be described.
The console 33 displays a screen that allows selection of three levels of permissible voltage levels, three levels of distance levels, and whether or not the nozzle 18 is present, and allows the user to select a permissible voltage level according to the permissible voltage of the object to be neutralized W. The distance level corresponding to the distance L between the charge removal object W and the discharge needle 17 and the presence or absence of the nozzle 18 are selected. Then, the control unit 31 reads the frequency associated with the combination of the allowable band voltage level, the distance level, and the presence / absence of the nozzle selected by the console 33 from the storage unit 34, and reads the frequency from the work memory in the control unit 31. 32 is stored as a command frequency. Then, by the control unit 31, a positive high voltage and a negative high voltage at a frequency according to the allowable band voltage of the charge removal object W, the distance L between the charge removal object W and the discharge needle 17, and the presence or absence of the nozzle 18. Are alternately applied to the discharge needle 17.

  For this reason, according to the allowable band voltage of the static elimination object W, the higher the positive band voltage level, the higher the positive voltage and the negative high voltage are alternately applied to the discharge needle 17. The Accordingly, when the allowable band voltage of the static elimination object W is low, the command frequency is set high, so that the voltage generated in the static elimination object W due to reverse charging can be suppressed low, and thus the static elimination object W is electrostatically discharged. It is suppressed that it becomes a nonconforming product by such as. Further, depending on the distance L between the static elimination object W and the discharge needle 17, the higher the frequency, the higher the positive voltage and the negative high voltage with respect to the discharge needle 17. Applied. Therefore, when the distance L between the static elimination object W and the discharge needle 17 is short, the command frequency is set higher, so that the voltage generated in the static elimination object W due to reverse charging can be suppressed to a lower level. The object W is more reliably suppressed from becoming a nonconforming product due to electrostatic discharge or the like.

  In the case where the nozzle 18 is provided, the command frequency is set to be higher so that the nozzle 18 is prevented from being charged. Therefore, ions generated by the discharge needle 17 can neutralize the nozzle 18. The static elimination object W is neutralized efficiently without disappearing. In this manner, when the nozzle 18 is provided, it is possible to irradiate ions locally, so that the bottom of the groove formed in the static elimination object W is suitably eliminated. In addition, since it becomes possible to irradiate ion over a wide range when the nozzle 18 is removed, the static elimination object W is neutralized. And since the nozzle 18 is detachable with respect to the static elimination apparatus 11, it can discharge suitably according to the static elimination object W. FIG.

As described above, according to the present embodiment, the following effects can be obtained.
(1) On the console 33, a screen capable of selecting three levels of permissible voltage levels, three levels of distance levels, and the presence or absence of the nozzle 18 is displayed. The distance level corresponding to the distance L between the static elimination object W and the discharge needle 17 and the presence or absence of the nozzle 18 are selected. The control unit 31 reads out the frequency associated with the combination of the allowable band voltage level, the distance level, and the presence / absence of the nozzle 18 selected by the console 33 from the storage unit 34, and reads the frequency from the work memory 32 in the control unit 31. Is stored as a command frequency. The control unit 31 alternately applies a positive high voltage and a negative high voltage to the discharge needle 17 at a command frequency stored in the work memory 32. The storage unit 34 has a frequency obtained by adding a frequency according to the distance level and a frequency according to the presence / absence of the nozzle 18 to a frequency associated with each allowable band voltage level so as to increase as the allowable band voltage level decreases. , The permissible voltage level, the distance level, and the presence / absence of the nozzle 18 are associated with each other. For this reason, in accordance with the allowable band voltage of the static elimination object W, a positive high voltage and a negative high voltage are alternately applied to the discharge needle 17 at a higher frequency as the allowable band voltage level is lower. . Accordingly, when the allowable band voltage of the static elimination object W is low, the command frequency is set high, so that the voltage generated in the static elimination object W due to reverse charging can be suppressed low, and thus the static elimination object W is electrostatically discharged. Therefore, it is possible to eliminate static electricity appropriately. Further, depending on the distance L between the static elimination object W and the discharge needle 17, the higher the frequency, the higher the positive voltage and the negative high voltage with respect to the discharge needle 17. Applied. Therefore, when the distance L between the static elimination object W and the discharge needle 17 is short, the command frequency is set higher, so that the voltage generated in the static elimination object W due to reverse charging can be suppressed lower. It is possible to more reliably suppress the object W from becoming a non-conforming product due to electrostatic discharge or the like, and it is possible to perform static elimination appropriately.

  (2) In the case where the nozzle 18 is provided, the command frequency is set to be higher so that the nozzle 18 is prevented from being charged. Therefore, the ions generated by the discharge needle 17 discharge the nozzle 18. By doing so, the static elimination object W can be neutralized efficiently without disappearing.

In addition, you may implement this embodiment in the following aspects.
In the present embodiment, the frequencies associated with the combination of the allowable band voltage level, the distance level, and the presence or absence of the nozzle 18 are stored in the storage unit 34, and the allowable band voltage level, the distance level, and the nozzle selected by the console 33 are stored. Although the frequency associated with the combination of the presence or absence of 18 is read out and used as the command frequency, the present invention is not limited to this. For example, the frequency corresponding to the combination of the allowable band voltage level and the distance level is stored in the storage unit 34, and the frequency corresponding to the combination of the allowable band voltage level and the distance level selected by the console 33 is read out. When the nozzle 18 is provided, a frequency that is increased by adding a predetermined value to this frequency may be used as the command frequency.

  In the present embodiment, the storage unit 34 has three levels of permissible voltage levels corresponding to the permissible voltage of the static elimination object W and three levels of distance levels corresponding to the distance L between the static elimination object W and the discharge needle 17. Are stored, and an allowable voltage level corresponding to the allowable voltage of the static elimination object W and a distance level corresponding to the distance L between the static elimination object W and the discharge needle 17 are selected from these. However, the present invention is not limited to this, and the allowable voltage level and the distance level stored in the storage unit 34 may be any number of levels as long as they are two or more levels.

  In the present embodiment, the frequency corresponding to each combination of the allowable band voltage level, the distance level, and the presence / absence of the nozzle 18 is stored in the storage unit 34. However, the present invention is not limited to this, and a plurality of allowable band voltage levels and distances are stored. You may memorize | store the frequency each matched with the combination of the level in the memory | storage part 34. FIG. In addition, the frequency associated with the combination of the plurality of allowable band voltage levels and the presence / absence of the nozzle 18 may be stored in the storage unit 34, and the frequency associated with only the allowable band voltage level may be stored in the storage unit 34. May be. Even in this case, the positive high voltage and the negative high voltage are alternately applied to the discharge needle 17 at a frequency corresponding to the allowable band voltage of the static elimination object W. Can be suitably eliminated while suppressing non-conforming product due to electrostatic discharge or the like.

  In the present embodiment, the high voltage side switches 16a and 16b are configured by field effect transistors in which the allowable band voltage is increased by including silicon carbide as a semiconductor component. However, the present invention is not limited to this, and high voltage switching can be performed at high speed. If possible, other switching elements may be used, for example, a bipolar transistor in which silicon carbide is contained in the semiconductor component. Further, the switching of the high voltage may be performed at a high speed by arranging a plurality of switching elements in parallel without using the switching element having an increased allowable band voltage.

  In the present embodiment, the voltage doubler rectifier circuits 22 and 24 are configured as Cockcroft-Walton type voltage doubler rectifier circuits. However, the present invention is not limited thereto, and may be configured as a so-called Billard type voltage doubler rectifier circuit.

-In this embodiment, although the nozzle 18 was provided in the static elimination apparatus 11, it is not restricted to this but the nozzle 18 does not need to be provided.
In the present embodiment, AC voltage is supplied to the positive high voltage generation circuit 14 and the negative high voltage generation circuit 15 by the AC power source 12, but the present invention is not limited to this, and the voltage from the DC power source is converted into AC voltage by the inverter. The positive high voltage generation circuit 14 and the negative high voltage generation circuit 15 may be supplied.

  In this embodiment, air may be generated by a fan or the like, and ions may be sprayed on the static elimination object W by the air.

The block circuit diagram of a static elimination apparatus. The wave form diagram which shows the relationship between an allowable band voltage level and a frequency.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Static elimination apparatus, 13a, 13b ... Low voltage side switch, 14 ... Positive high voltage generation circuit, 15 ... Negative high voltage generation circuit, 16a, 16b ... High voltage side switch, 17 ... Discharge needle, 18 ... Nozzle, 31 ... Control part, 33 ... Console, 34 ... Storage, L ... Distance, W ... Static removal object.

Claims (3)

A discharge needle,
A high voltage generation circuit for generating a positive high voltage and a negative high voltage;
Control means for alternately applying the positive high voltage and the negative high voltage to the discharge needle at a predetermined command frequency;
In a static eliminator comprising a frequency setting means for setting the command frequency,
A first selection unit capable of selecting one allowable band voltage level corresponding to the allowable band voltage of the static elimination object from a plurality of preset allowable band voltage levels;
Storage means for storing frequencies respectively associated with the plurality of allowable band voltage levels,
The frequency setting unit reads a frequency associated with the allowable band voltage level selected by the first selection unit from the storage unit, and sets the frequency as the command frequency. . A second selection means capable of selecting one distance level corresponding to the distance between the static elimination object and the discharge needle from a plurality of preset distance levels;
The storage means stores a frequency associated with each combination of the plurality of allowable band voltage levels and the plurality of distance levels,
The frequency setting means stores a frequency associated with a combination of the allowable band voltage level selected by the first selection means and the distance level selected by the second selection means from the storage means. The static eliminator according to claim 1, wherein the charge is read and the frequency is set as the command frequency. A nozzle that supplies ions generated by the discharge needle to the static elimination object and is detachable;
Third selection means capable of selecting whether or not the nozzle is provided in the static eliminator,
The storage means stores a frequency associated with each combination of the plurality of permissible voltage levels, the plurality of distance levels, and the presence or absence of the nozzle,
The frequency setting means includes the allowable band voltage level selected by the first selection means, the distance level selected by the second selection means, and the nozzle selected by the third selection means. 3. The static eliminator according to claim 2, wherein a frequency associated with a combination of presence / absence of data is read from the storage unit, and the frequency is set as the command frequency.

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