JP2010212076A - Static eliminator and method for setting discharge stop timing in static eliminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a static eliminator which does not remain electrostatic charge on a workpiece when a discharge operation of corona discharge is stopped. <P>SOLUTION: The static eliminator 14 has an instruction device 12 for inputting permission or non-permission of the discharge operation of corona discharge at stopping of the discharge operation of a static electricity elimination system 10 including the static eliminator 14, a detection section 14a for detecting permission or non-permission of the discharge operation, and a discharge standstill-time processing section 14c for stopping the corona discharge when detecting non-permission of the discharge operation by the detection section 14a during the corona discharge. The discharge standstill-time processing section 14c can adjust a standstill time so as to stop the discharge operation of the corona discharge at timing when the workpiece is not at an electrified state if the corona discharge is to be stopped. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a static eliminator that applies positive and negative high voltage pulses to an electrode needle, generates positive and negative ions from the electrode needle by corona discharge, and neutralizes a charged workpiece, and a discharge stop timing setting method.

  The static eliminator neutralizes positive and negative charges charged on the workpiece by ejecting positive and negative ions to the workpiece, and neutralizes the workpiece. Patent Document 1 proposes an ion balance adjustment method for positive and negative ions in a static elimination space in which a static elimination device neutralizes the workpiece.

JP 2007-149419 A

  In the static eliminator described above, positive and negative high voltage pulses are applied to the electrode needle, and positive and negative ions are generated by corona discharge generated at the tip of the electrode needle. In this case, in order to perform the corona discharge, the positive and negative high voltage pulses are alternately switched and applied. In the static elimination space, there is a change in the amplitude of the potential according to the pulse width of the positive and negative high voltage pulses. For this reason, when the discharge operation of the corona discharge is stopped, the polarity corresponding to the amplitude of the potential generated when the discharge is stopped remains. The remaining polarity affects the ion balance in the static elimination space after the discharge operation of the corona discharge is stopped, and the work is left charged. Therefore, in the conventional static eliminator, it is necessary to remove the charge remaining on the workpiece surface with the static eliminator brush when the discharge operation is stopped in static erasure of electronic components such as semiconductor integrated circuits that are sensitive to static electricity failure. This is annoying in this respect.

  The present invention has been made to solve the above-described problems, and provides a static elimination device that does not leave a charge remaining on a workpiece in a static elimination space when the discharge operation of the corona discharge is stopped, and a method for setting a discharge stop timing. The purpose is to do.

In order to achieve the above object, a static eliminator according to the present invention applies positive and negative high voltage pulses with a fixed period to an electrode needle, generates positive and negative ions from the electrode needle by corona discharge, and eliminates static electricity on a workpiece. In the static eliminator to perform,
A detector for detecting non-permission of discharge operation during corona discharge;
When the non-permission of the discharge operation is detected by the detection unit, a discharge operation stop time processing unit that stops the discharge operation of the corona discharge;
Have
The discharge operation stop processing unit stops the corona discharge discharge operation at a timing at which the workpiece is not charged when the corona discharge discharge operation is stopped.

  In addition, the discharge stop timing setting method in the static eliminator according to the present invention applies positive and negative high voltage pulses with a constant period to the electrode needle, generates positive and negative ions from the electrode needle by corona discharge, In the method for setting the discharge stop timing in the static eliminator to be performed, the step of detecting non-permission of the discharge operation during the corona discharge, and the discharge operation of the corona discharge is stopped when the non-permission of the discharge operation is detected A discharge operation stop processing step, and in the discharge operation stop processing step, when the discharge operation of the corona discharge is stopped, the discharge operation of the corona discharge is stopped at a timing at which the workpiece is not charged. It is characterized by making it.

  According to each of the above-described inventions, when the non-permission of the corona discharge discharge operation is detected, the application of the high voltage pulse to the electrode needle is immediately continued without stopping, and the charging due to the corona discharge discharge operation remains. It is made to stop at the timing not to let it.

  As a result, the ion balance in the static elimination space is balanced, and the discharge operation of the static elimination device can be stopped without causing any charge to remain on the workpiece in the static elimination space.

  Furthermore, the static eliminator according to the present invention further includes a potential sensor that detects a charge amount of the work, and the discharge operation stop time processing unit determines the timing at which the work is not charged by the potential sensor. The timing is such that the charge amount is minimized.

  Further, in the static eliminator according to the present invention, when the discharge operation stop time processing unit stops the discharge operation of the corona discharge, the high voltage pulse is held while holding the voltage of the high voltage pulse causing the corona discharge. The discharge operation of the corona discharge is stopped after gradually reducing the pulse width of the pulse.

  Furthermore, in the static eliminator according to the present invention, when the discharge operation stop time processing unit stops the discharge operation of the corona discharge, the high voltage pulse is held while holding the voltage of the high voltage pulse causing the corona discharge. The discharge operation of the corona discharge is stopped after setting the pulse repetition frequency to be higher than the frequency of the fixed period.

  Further, in the static eliminator according to the present invention, when the discharge operation stop time processing unit stops the discharge operation of the corona discharge, the high voltage pulse is held while holding the voltage of the high voltage pulse causing the corona discharge. The discharge operation of the corona discharge is stopped after the pulse repetition frequency is gradually increased from the constant cycle frequency.

  According to the present invention, when the discharge operation of the corona discharge is stopped, the balance between positive and negative ions in the static elimination space can be balanced, and no charge remains on the work in the static elimination space.

FIG. 1 is a schematic diagram of a static elimination system including a static elimination device according to the first embodiment. FIG. 2 is a flowchart of a discharge stop process in the static eliminator of FIG. FIG. 3 is a time chart of the static eliminator. FIG. 4 is a schematic diagram of a charge removal system including a charge removal apparatus according to the second embodiment. FIG. 5 is a charge amount map according to the static eliminator of FIG. FIG. 6 is a flowchart of a discharge stop process in the static eliminator of FIG. FIG. 7 is a schematic diagram of a charge removal system including a charge removal device according to the third embodiment. FIG. 8 is an example of a charge amount map according to the third embodiment. FIG. 9 is a schematic diagram of a charge removal system including a charge removal apparatus according to the fourth embodiment. FIG. 10 is a schematic diagram of a discharge stop process in the static eliminator according to the fourth embodiment. FIG. 11 is an example of a charge amount map according to the fourth embodiment. FIG. 12 is a flowchart of a discharge stop process in the static eliminator according to the fourth embodiment. FIG. 13 is an example of a charge amount map according to the fifth embodiment. FIG. 14 is an example of a charge amount map according to the sixth embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a method for setting a discharge stop timing in a static eliminator according to the present invention will be described in detail with reference to the accompanying drawings by giving a preferred embodiment in relation to the static eliminator that implements this.

  FIG. 1 is a schematic diagram of a charge removal system 10 including a charge removal device 14 according to a first embodiment that is configured not to leave a charge on a work W in a charge removal space Sp when a discharge operation of corona discharge is stopped.

  The static eliminator system 10 includes a command device 12, a static eliminator 14 that generates corona discharge, a positive high voltage generator 16a, a negative high voltage generator 16b, a positive electrode needle 18a, and a negative electrode needle 18a. It has an electrode needle 18b and a potential sensor 20 that detects a charge amount C on the surface of the workpiece W.

  The command device 12 is an external input device, and in this case, is constituted by a sequencer. The command device 12 outputs a discharge operation permission signal SON when connected to the high level side of the voltage + Vcc, and outputs a discharge operation non-permission signal SOFF when connected to the low level side of the ground.

  The static eliminator 14 includes a detection unit 14a, a discharge command generation unit 14b, and a discharge operation stop time processing unit 14c.

  Here, the detection unit 14a detects a signal (a discharge operation permission signal SON or a discharge operation non-permission signal SOFF) from the command device 12, and when the discharge operation permission signal SON is detected, a drive signal to the discharge command generation unit 14b. When Sd1 is sent and the discharge operation non-permission signal SOFF is detected, the drive signal Sd2 is sent to the discharge operation stop time processing unit 14c.

  When receiving the drive signal Sd1, the discharge command generator 14b sends discharge commands V1c and V2c at the time of discharge to the positive high voltage generator 16a and the negative high voltage generator 16b.

  The positive high voltage generator 16a and the negative high voltage generator 16b apply high voltage pulses Vp and Vm according to the received discharge commands V1c and V2c to the electrode needle 18a and the electrode needle 18b, respectively.

  When the discharge operation stop processing unit 14c receives the drive signal Sd2, the discharge operation stop processing unit 14c controls the discharge command generation unit 14b to perform a corona discharge stop processing described later.

  The potential sensor 20 installed in the vicinity of the surface of the workpiece W sends out the charge amount C detected on the surface of the workpiece W to the discharge operation stop time processing unit 14c.

  In FIG. 1, for easy understanding, a positive ion 22 is indicated by adding a character “+” in a circle, and a negative ion 24 is indicated by adding a character “−” in the circle. Is written.

  The static elimination system 10 according to the first embodiment is basically configured and operates as described above. Next, the flowchart of the static elimination procedure by the static elimination system 10 shown in FIG. 2 and the static elimination device shown in FIG. The detailed operation will be described with reference to the time chart of the charge removal procedure according to FIG.

  In step S1, the detection unit 14a determines whether or not a discharge operation permission signal SON has been sent from the command device 12 based on an operation of the command device 12 such as a user. In step S1, when the detection unit 14a receives the discharge operation permission signal SON (time point t1), the drive signal Sd1 for driving the discharge command generation unit 14b is sent to the discharge command generation unit 14b.

  In step S2, based on receipt of the drive signal Sd1, the discharge command generator 14b generates positive and negative discharge commands V1c and V2c having a constant cycle Tp whose waveforms are shown in FIG. 3, and each of them is a positive high voltage generator 16a. And sent to the negative high voltage generator 16b.

  In this case, the positive high voltage generation unit 16a and the negative high voltage generation unit 16b respectively receive positive and negative high voltage pulses Vp and Vm (see FIG. 3) having a fixed period according to the received positive and negative discharge commands V1c and V2c. Apply to the electrode needles 18a, 18b.

  During the generation of the discharge commands V1c and V2c, in the next step S3, the detector 14a determines whether or not the discharge operation non-permission signal SOFF is sent from the command device 12, and receives the discharge operation non-permission signal SOFF. At (time t2), the transmission of the drive signal Sd1 to the discharge command generation unit 14b is stopped, while the drive signal Sd2 is transmitted to the discharge operation stop time processing unit 14c.

  Upon receiving the drive signal Sd2, the discharge operation stop time processing unit 14c performs the discharge operation stop time processing Sa in steps S4 to S6 for controlling the stop timing of the discharge command generation unit 14b.

  In step S <b> 4, the discharge operation stop time processing unit 14 c takes in the charge amount C detected by the potential sensor 20.

  In step S5, it is determined whether the captured charge amount C is below a preset threshold Cth, that is, whether | C | <Cth is satisfied.

  When it is determined that the charge amount C has fallen below the threshold Cth (time point t3), in step S6, the discharge operation stop time processing unit 14c stops the generation of the discharge commands V1c and V2c by the discharge command generation unit 14b (simultaneous point t3). ). Thereby, corona discharge through the electrode needles 18a and 18b is stopped. In the time chart of FIG. 3, the delay time td on the waveform of the charge amount C is a time corresponding to the ion transmission delay time from the electrode needles 18a and 18b to the workpiece W (the potential sensor 20).

  As described above, the static eliminator system 10 including the static eliminator 14 according to the first embodiment applies positive and negative high voltage pulses Vp and Vm having a constant period Tp to the electrode needles 18a and 18b, and from the electrode needles 18a and 18b by corona discharge. Positive and negative ions are generated to neutralize the workpiece W. In this case, the static elimination system 10 includes a command device 12 that inputs a discharge operation permission signal SON that indicates permission of a corona discharge discharge operation or a discharge operation permission signal SOFF that indicates that a corona discharge discharge operation is not permitted, and a discharge operation permission. A detection unit 14a for detecting the signal SON or the discharge operation non-permission signal SOFF, and a discharge operation stop time processing unit 14c for stopping the corona discharge when the detection unit 14a detects the discharge operation non-permission signal SOFF during the corona discharge. And a potential sensor 20 for detecting the charge amount C of the workpiece W, and the discharge operation stop time processing unit 14c has a small value so that the workpiece W is not charged when the discharge operation of the corona discharge is stopped. The discharge operation of the corona discharge is stopped at the timing when the charge amount C (| C | <Cth) is reached.

  In this way, the discharge is not stopped immediately at the timing (time t2) when the command device 12 inputs the discharge operation non-permission signal SOFF to the detection unit 14a, but after that (after time t2). Since the application of the positive and negative high voltage pulses Vp and Vm to the electrode needles 18a and 18b is continued, the discharge operation of the corona discharge can be stopped at a timing that does not leave any charge (| C | <Cth). it can.

  That is, in the static eliminator 10 including the static eliminator 14 of the first embodiment, when the discharge operation of the corona discharge is stopped, the ion balance in the static eliminator space Sp is balanced, and the workpiece W in the static eliminator space Sp is charged. It can be made not to remain.

  FIG. 4 is a schematic diagram of a charge removal system 10a including a charge removal device 14A according to the second embodiment that is configured so that no charge remains on the workpiece W in the charge removal space Sp when the discharge operation of the corona discharge is stopped.

  The neutralization system 10a according to the second embodiment is different from the neutralization system 10 according to the first embodiment in that the potential sensor 20 is omitted and the discharge operation stop time processing unit 14c is changed to a discharge operation stop time processing unit 14ca. Differently, the other components are the same as the components of the static elimination system 10.

  The discharge operation stop time processing unit 14ca includes a timer 26 as a timing unit and a charge amount map storage unit 28 for storing a charge amount map 30 (charge amount characteristic) shown in FIG.

  The timer 26 is a preset down timer (preset down counter) that measures the time from when the discharge operation stop time processing unit 14ca receives the drive signal Sd2 to when the discharge operation is stopped. The timer 26 is set with a preset time Tpreset read from the charge amount map 30 by the discharge operation stop time processing unit 14ca that has received the drive signal Sd2.

  As shown in FIG. 5, the charge amount map 30 represents the relationship between the timing of the discharge commands V1c and V2c and the charge amount C, and is measured in advance and stored in the charge amount map storage unit 28.

  Next, the operation of the static eliminator 14A of the second embodiment will be described based on the flowchart of FIG.

  Since the processing of steps S1 to S3 is the same as that of the first embodiment, a description thereof will be omitted.

  The discharge operation stop process Sa in steps S4 to S6 in the first embodiment is replaced with the discharge operation stop process Sb in steps S7 to S11 in the second embodiment.

  In step S3, at the timing when the discharge operation stop processing unit 14ca receives the drive signal Sd2 sent from the detection unit 14a (time t2 in FIG. 5), the discharge operation stop processing unit 14ca stops the discharge command generation unit 14b. A discharge operation stop process Sb in steps S7 to S11 for controlling the timing is performed.

  In step S7, the discharge operation stop time processing unit 14ca reads the charge amount C0 corresponding to the time point t2 on the charge amount map 30, and the time point t3 when the charge amount C0 first falls below a preset threshold Cth after the time point t2. Is read as a preset time Tpreset.

  In step S8, the discharge operation stop time processing unit 14ca sets the read preset time Tpreset in the timer 26 as an initial value of the count value T.

  In step S9, the timer 26 determines whether or not the count value T has become 0.

  When the count value T is not 0, the count value T is decreased by the unit time “1” in step S10 (T ← T−1), and when it is determined in step S9 that the count value T is 0 (FIG. 5 at time t3), in step 11, the discharge operation stop time processing unit 14ca stops the generation of the discharge commands V1c and V2c in the discharge command generation unit 14b (simultaneous point t3 in FIG. 5). Thereby, corona discharge stops.

  As described above, the static eliminator 10a including the static eliminator 14A according to the second embodiment includes the discharge operation permission signal SON that indicates permission of the corona discharge discharge operation or the discharge operation non-permission signal SOFF that indicates that the corona discharge discharge operation is not permitted. , A detection unit 14a for detecting a discharge operation permission signal SON or a discharge operation non-permission signal SOFF, and a corona discharge when the discharge unit non-permission signal SOFF is detected by the detection unit 14a during corona discharge. A discharge operation stop processing unit 14ca that stops the discharge operation, and the discharge operation stop processing unit 14ca discharges the corona discharge at a timing at which the workpiece W is not charged when the discharge operation of the corona discharge is stopped. The operation is stopped.

  In this way, the discharge is not stopped immediately at the timing (time t2) when the command device 12 inputs the discharge operation non-permission signal SOFF to the detection unit 14a, but after that (after time t2). Since the application of the positive and negative high voltage pulses Vp and Vm to the electrode needles 18a and 18b is continued, the discharge operation of the corona discharge can be stopped at a timing (| C | <Cth) at which charging does not remain. it can.

  That is, also in the static elimination system 10a including the static eliminator 14A of the second embodiment, when the discharge operation of the corona discharge is stopped, the ion balance in the static elimination space Sp is balanced, and the workpiece W in the static elimination space Sp is charged. Can be prevented from remaining.

  FIG. 7 is a schematic diagram of a charge removal system 10b including a charge removal device 14A2 according to the third embodiment configured to prevent the charge W from remaining in the work W in the charge removal space Sp when the discharge operation of the corona discharge is stopped.

  The static elimination system 10b of the third embodiment includes a high voltage generation unit 16, an electrode needle 18, and a ground electrode 32. A positive or negative high voltage pulse is applied to the electrode needle 18, and the ground electrode 32 is interposed between the ground electrode 32 and the ground electrode 32. Corona discharge is generated at the tip of the electrode needle 18 by utilizing the potential difference.

  The neutralization system 10b according to the third embodiment differs from the neutralization systems 10 and 10a according to the first and second embodiments in that the number of electrode needles 18 is one.

  The static eliminator 14A2 includes a detection unit 14a, a discharge command generation unit 14ba, and a discharge operation stop time processing unit 14cb.

  Here, when the drive signal Sd1 is sent from the detection unit 14a to the discharge command generation unit 14ba, the discharge command generation unit 14ba sends the discharge command V3c at the time of discharge to the high voltage generation unit 16.

  The high voltage generator 16 applies positive and negative high voltage pulses Vpn to the electrode needle 18 in accordance with the received discharge command V3c.

  The discharge operation stop time processing unit 14 cb includes a timer 26 and a charge amount map storage unit 28 that stores a charge amount map 34.

  FIG. 8 shows the contents of the charge amount map 34 of the static eliminator 14A2 of the third embodiment. As shown in the charge amount map 34, the discharge command V3c output from the discharge command generation unit 14ba has a pulse waveform in which positive and negative square waves are repeated for a certain period Tp.

  The flowchart explaining the operation of the static eliminator 14A2 of the third embodiment can share the flowchart of FIG.

  The static eliminator system 10b according to the third embodiment includes a command device 12 that inputs a discharge operation permission signal SON that indicates permission of the discharge operation of corona discharge or a discharge operation non-permission signal SOFF that indicates non-permission of the discharge operation of corona discharge; Detection unit 14a for detecting discharge operation permission signal SON or discharge operation non-permission signal SOFF, and discharge operation stop process for stopping corona discharge when detection unit 14a detects discharge operation non-permission signal SOFF during corona discharge 14cb, and when the discharge operation stop processing unit 14cb stops the discharge operation of the corona discharge, the discharge operation of the corona discharge is stopped at a timing at which the workpiece W is not charged. .

  In this way, the discharge is not stopped immediately at the timing (time t2) when the command device 12 inputs the discharge operation non-permission signal SOFF to the detection unit 14a, but after that (after time t2). Since the application of the positive and negative high voltage pulse Vpn to the electrode needle 18 is continued, the discharge operation of the corona discharge can be stopped at a timing (| C | <Cth) at which charging does not remain.

  That is, also in the static elimination system 10b including the static elimination device 14A2 of the third embodiment, when the discharge operation of the corona discharge is stopped, the ion balance in the static elimination space Sp is balanced, and the workpiece W in the static elimination space Sp is charged. Can be prevented from remaining.

  FIGS. 9 and 10 are schematic views of a charge removal system 10c including a charge removal device 14A3 according to the fourth embodiment, which is configured so that no charge remains on the workpiece W in the charge removal space Sp when the discharge operation of the corona discharge is stopped. .

  The static eliminator system 10c including the static eliminator 14A3 according to the fourth embodiment is different from the static eliminator 10b including the static eliminator 14A2 according to the above-described third embodiment with respect to the discharge operation stop time processing unit 14cb of the static eliminator 14A2. And a discharge operation stop processing unit 14cc capable of sending a stop signal Sstop, and a discharge command generation unit 14ba being changed to a discharge command generation unit 14bb capable of arbitrarily generating a pulse width of a discharge command. About the component, it is the same as that of the static elimination system 10b containing static elimination apparatus 14A2 and static elimination apparatus 14A2.

  In this case, when the drive signal Sd1 is sent from the detection unit 14a to the discharge command generation unit 14bb, the discharge command generation unit 14bb sends out the discharge command V3c described in the third embodiment as shown in FIG.

  When the drive signal Sd2 is sent from the detection unit 14a to the discharge operation stop time processing unit 14cc (t2 in FIG. 11), the discharge operation stop time processing unit 14cc stops at the discharge command generation unit 14bb at time t4 in FIG. A preprocessing signal Spr is transmitted.

  At this time, the discharge command generator 14bb generates the discharge command V4c (details will be described later) simultaneously with receiving the pre-stop processing signal Spr from the discharge operation stop time processing unit 14cc (time t4 in FIG. 11).

  Here, in the static elimination systems 10d and 10e including the static elimination devices 14A3 of Examples 5 and 6 to be described later, the discharge command V4c is changed to the discharge commands V5c and V6c, respectively.

  The discharge operation stop time processing unit 14 cc includes a timer 26 and a charge amount map storage unit 28 that stores a charge amount map 36.

  FIG. 11 shows a charge amount map 36 stored in the static eliminator 14A3 according to the fourth embodiment, which is configured so that no charge remains in the workpiece W in the static elimination space Sp when the discharge operation of the corona discharge is stopped.

  Here, the discharge command V4c means that the application of the positive and negative high voltage pulses Vpn to the electrode needle 18 is started in the repetition time of the constant cycle Tp / 2, and the middle of the repetition time of the constant cycle Tp / 2 (in FIG. 11). The discharge command is such that the application is stopped at tr1, tr2, t5) and the application pause time is provided, and the pause time widths R1, R2, and R3 in FIG. 11 gradually increase in time width (R1 <R2 < R3).

  That is, the charge amount map 36 represents the relationship between the charge amount C and the discharge command V3c and the discharge command V4c described above from the time point t0 to t4, which is a predetermined period Tp before the time point t4, and is stored. In the time range, the charge amount (Cr1, Cr2, Cr3,...) For each repetition time Tp / 2 first falls below the threshold Cth (| Crx | <Cth, x = 1, 2, 3,...) Time (FIG. 11). In this case, the range is up to Cr3, time t5), measured in advance, and stored in the charge amount map storage unit 28.

  The charge amount map 36 in FIG. 11 is illustrated by using an example in which the charge amount C at the time point t4 in FIG. 11 at which the stop preprocessing signal Spr is sent is a negative peak value, but at the time point t4. The charge amount C may be a positive peak value. In this case, the charge amount C is axisymmetric with respect to FIG. 11 with respect to C = 0.

  Next, the operation of the static eliminator 14A3 of the fourth embodiment will be described based on the flowchart of FIG.

  Since the processing of steps S1 to S3 is the same as that of the first embodiment, a description thereof will be omitted.

  The discharge operation stop time process Sa in steps S4 to S6 in the first embodiment is replaced with the discharge operation stop time process Sc in steps S12 to S21 in the fourth embodiment.

  In step S3, when the discharge operation stop processing unit 14cc receives the drive signal Sd2 sent from the detection unit 14a (at time t2 in FIG. 11), the discharge operation stop processing unit 14cc stops the discharge command generation unit 14bb. A discharge operation stop process Sc in steps S12 to S21 for controlling the timing is performed.

  In step S12, the discharge operation stop processing unit 14cc presets the time t2 on the charge amount map 36 and the time until t4 in FIG. 11 when the electrode needle 18 first applies one high voltage pulse after t2. Read as time Tpreset1.

  In step S13, the discharge operation stop time processing unit 14cc sets the read preset time Tpreset1 in the timer 26 as an initial value of the count value T.

  In step S14, the timer 26 determines whether or not the count value T has reached the value 0.

  When the count value T is not 0, the count value T is decreased by the unit time “1” in step S15 (T ← T−1), and when the count value T is determined to be 0 in step S14 (FIG. 11 at time t4), in step S16, the discharge operation stop time processing unit 14cc sends a pre-stop processing signal Spr.

  In step S17-1, the discharge command generation unit 14bb receives the pre-stop processing signal Spr from the discharge operation stop time processing unit 14cc, and switches the discharge command from V3c to V4c.

  In step S17-2, simultaneously with step S17-1, the discharge operation stop time processing unit 14cc reads the time from time t4 to t5 on the charge amount map 36 as the preset time Tpreset2.

  In step S18, the discharge operation stop time processing unit 14cc sets the read preset time Tpreset2 in the timer 26 as an initial value of the count value T.

  In step S19, the timer 26 determines whether or not the count value T has reached the value 0.

  When the count value T is not 0, the count value T is decreased by the unit time “1” in step S20 (T ← T−1), and when it is determined in step S19 that the count value T is 0 (FIG. 11 at time t5), in step S21, the discharge operation stop time processing unit 14cc stops the generation of the discharge command V4c in the discharge command generation unit 14bb (simultaneous point t5 in FIG. 11). Thereby, corona discharge stops.

  The charge amount map 36 according to the static eliminator 14A3 of the fourth embodiment is based on the high voltage pulse Vpn that causes corona discharge when the discharge operation stop time processing unit 14cc stored in the charge amount map 36 stops the corona discharge discharge operation. The discharge operation of the corona discharge can be stopped after gradually reducing the pulse width of the high voltage pulse Vpn while maintaining the voltage.

  Thereby, also in the static elimination system 10c including the static elimination apparatus 14A3 of the fourth embodiment, when the discharge operation of the corona discharge is stopped, the ion balance in the static elimination space Sp is balanced, and the work W in the static elimination space Sp is balanced. It is possible to prevent charging from remaining.

  FIG. 13 shows a charge amount map 38 related to the charge removal system 10d including the charge removal device 14A3 according to the fifth embodiment, which is configured not to leave charge on the workpiece W in the charge removal space Sp when the discharge operation of the corona discharge is stopped. .

  The neutralization system 10d according to the fifth embodiment can use the configuration illustrated in FIGS. 9 and 10 of the neutralization system 10c according to the fourth embodiment described above and the flowchart illustrated in FIG.

  Here, the discharge operation stop time processing unit 14 cc includes a timer 26 and a charge amount map storage unit 28 for storing a charge amount map 38.

  In this case, when the drive signal Sd1 is sent from the detection unit 14a to the discharge command generation unit 14bb, the discharge command generation unit 14bb sends the discharge command V3c.

  When the drive signal Sd2 is sent from the detection unit 14a to the discharge operation stop time processing unit 14cc (t2 in FIG. 13), the discharge operation stop time processing unit 14cc stops at the discharge command generation unit 14bb at time t4 in FIG. A preprocessing signal Spr is transmitted.

  At this time, the discharge command generation unit 14bb generates a discharge command V5c, which will be described later, simultaneously with receiving the pre-stop processing signal Spr from the discharge operation stop time processing unit 14cc (time t4 in FIG. 13).

  Here, the discharge command V5c is a command for generating a pulse waveform in which a positive and negative square wave repeats at a constant cycle Tp2, which is shorter than the constant cycle Tp in V3c, that is, at a high frequency.

  The charge amount map 38 represents the relationship between the charge command C and the discharge command V3c from time t0 to time t4, and the discharge command V5c from time t4 to t5, which is a fixed period Tp before time t4, and V5c is The stored time range starts at time t4, and the charge amount (Cr1, Cr2,...) For each repetition time period Tp2 at which generation of a negative peak value discharge command is completed first falls below the threshold Cth (| Crx | < Cth, x = 1, 2,...) Range (Cr8 in FIG. 13, time point t5), measured in advance, and stored in the charge amount map storage unit 28.

  Note that the charge amount map 38 in FIG. 13 is illustrated using an example in which the charge amount C at the time point t4 in FIG. 13 at which the stop pre-processing signal Spr is sent is a positive peak value, but at the time point t4. The charge amount C may be a negative peak value. In this case, the charge amount C is axisymmetric with respect to FIG. 13 with respect to C = 0.

  The charge amount map 38 according to the static eliminator system 10d of the fifth embodiment includes a high voltage pulse Vpn that causes corona discharge when the discharge operation stop time processing unit 14cc stored in the charge amount map 38 stops the corona discharge discharge operation. The discharge operation of the corona discharge can be stopped after setting the repetition frequency of the pulse width of the high voltage pulse Vpn to a high repetition frequency with a period Tp2 shorter than the constant period Tp while maintaining the voltage.

  Thereby, also in the static elimination system 10d including the static elimination device 14A3 of the fifth embodiment, when the discharge operation of the corona discharge is stopped, the ion balance in the static elimination space Sp is balanced, and the workpiece W in the static elimination space Sp is balanced. It is possible to prevent charging from remaining.

  FIG. 14 shows a charge amount map 40 according to the charge removal system 10e including the charge removal device 14A3 of the sixth embodiment configured to prevent the charge from remaining on the workpiece W in the charge removal space Sp when the discharge operation of the corona discharge is stopped. .

  The neutralization system 10e according to the sixth embodiment can use the configuration illustrated in FIGS. 9 and 10 and the flowchart illustrated in FIG. 12 of the neutralization system 10c according to the fourth embodiment described above.

  Here, the discharge operation stop time processing unit 14 cc includes a timer 26 and a charge amount map storage unit 28 that stores a charge amount map 40.

  In this case, when the drive signal Sd1 is sent from the detection unit 14a to the discharge command generation unit 14bb, the discharge command generation unit 14bb sends the discharge command V3c.

  When the drive signal Sd2 is sent from the detection unit 14a to the discharge operation stop time processing unit 14cc (t2 in FIG. 14), the discharge operation stop time processing unit 14cc stops at the discharge command generation unit 14bb at time t4 in FIG. A preprocessing signal Spr is transmitted.

  At this time, the discharge command generation unit 14bb generates a discharge command V6c, which will be described later, at the same time when the pre-stop processing signal Spr is received from the discharge operation stop time processing unit 14cc (time t4 in FIG. 14).

  Here, the discharge command V6c is a command for generating a pulse waveform that repeats positive and negative square waves while gradually decreasing the cycle from the constant cycle Tp of V3c, that is, gradually increasing the frequency.

  The charge amount map 40 in FIG. 14 is illustrated by using an example in which the charge amount C at the time point t4 in FIG. 14 at which the stop preprocessing signal Spr is sent is a negative peak value, but at the time point t4. The charge amount C may be a positive peak value. In this case, the charge amount C is axisymmetric with respect to FIG. 14 with respect to C = 0.

  The charge amount map 40 related to the charge removal system 10e including the charge removal device 14A3 of the sixth embodiment causes corona discharge when the discharge operation stop time processing unit 14cc stored in the charge amount map 40 stops the discharge operation of the corona discharge. While maintaining the voltage of the high voltage pulse Vpn, the discharge operation of the corona discharge can be stopped after the repetition frequency of the high voltage pulse Vpn is gradually increased from the frequency of the constant period Tp.

  Thereby, also in the static elimination system 10e including the static elimination apparatus 14A3 of Example 6, when the discharge operation of the corona discharge is stopped, the ion balance in the static elimination space Sp is balanced, and the workpiece W in the static elimination space Sp is balanced. It is possible to prevent the charge from remaining.

10, 10a, 10b, 10c, 10d, 10e ... neutralization system 12 ... command device 14, 14A, 14A2, 14A3 ... neutralization device 14a ... detection unit 14b, 14ba, 14bb ... discharge command generation unit 14c, 14ca, 14cb, 14cc ... Discharge operation stop processing unit 16, 16a, 16b ... High voltage generation unit 18, 18a, 18b ... Electrode needle 20 ... Potential sensor 26 ... Timer 28 ... Charge amount map storage unit 30, 34, 36, 38, 40 ... Charge amount Map 32 ... Ground electrode

Claims (6)

In the static eliminator that applies positive and negative high voltage pulses of a certain period to the electrode needle, generates positive and negative ions from the electrode needle by corona discharge, and neutralizes the workpiece.
A detector for detecting non-permission of discharge operation during corona discharge;
When the non-permission of the discharge operation is detected by the detection unit, a discharge operation stop time processing unit that stops the discharge operation of the corona discharge;
Have
The discharging operation stop processing unit stops the corona discharge discharging operation at a timing at which the workpiece is not charged when the corona discharge discharging operation is stopped. In the static elimination apparatus of Claim 1,
A potential sensor for detecting the amount of charge of the workpiece;
The discharging operation stop processing unit sets a timing at which the workpiece is not charged to a timing at which a charge amount of the workpiece by the potential sensor is minimized. In the static elimination apparatus of Claim 1,
When the discharge operation stop processing unit stops the discharge operation of the corona discharge, the pulse width of the high voltage pulse is gradually reduced while maintaining the voltage of the high voltage pulse that causes the corona discharge. A discharging device for stopping the corona discharge later. In the static elimination apparatus of Claim 1,
When the discharge operation stop processing unit stops the discharge operation of the corona discharge, the repetitive frequency of the high voltage pulse is set to the frequency of the constant period while holding the voltage of the high voltage pulse causing the corona discharge. The discharging operation of the corona discharge is stopped after a higher frequency is set. In the static elimination apparatus of Claim 1,
When the discharge operation stop processing unit stops the discharge operation of the corona discharge, the repetitive frequency of the high voltage pulse is set to the frequency of the constant period while holding the voltage of the high voltage pulse causing the corona discharge. The discharge operation of the corona discharge is stopped after the frequency is gradually increased from 1. In the setting method of the discharge stop timing in the static eliminator that applies positive and negative high voltage pulses of a certain period to the electrode needle, generates positive and negative ions from the electrode needle by corona discharge, and neutralizes the workpiece,
Detecting non-permission of the discharge operation during the corona discharge;
Discharge operation stop processing step for stopping the discharge operation of the corona discharge when detecting non-permission of the discharge operation;
Have
In the discharge operation stop processing step, when stopping the corona discharge discharge operation, the discharge operation of the corona discharge is stopped at a timing at which the workpiece is not charged. Setting method.

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