KR102493135B1 - Charge Plate Monitor with small charging plate based on network - Google Patents

Abstract

A network-based charge plate monitoring device having a small charge plate includes a charge plate including a top plate for collecting ions and a bottom plate as a counter electrode, and a high voltage for outputting a preset output voltage to the charge plate. A generator, a voltage balancing circuit having a potential parallel to the potential of the charging plate in order to proportionally measure the change in potential of the charging plate, an analog-to-digital converter having the potential of the voltage balancing circuit as an input signal, and an analog-to-digital converter It is characterized in that it comprises an embedded data processing unit for collecting output signals.

Description

Charge plate monitoring device having a network-based small charging plate {Charge Plate Monitor with small charging plate based on network}

The present invention relates to a charge plate monitoring device, and more particularly, to a network-based charge plate monitoring device having a small electrification plate.

As the industry advances, suppression and prediction technology for ESD (Electrostatic Discharge) in the system and electronics industry due to static electricity are emerging as major technologies with great industrial ripple effects.

In particular, as the understanding of the electrostatic discharge problem due to the high density and high integration of electronic circuits increases in the electronics industry, it is necessary to develop technologies and products for countermeasures and analysis of electrostatic disturbances in the electronics and semiconductor fields.

An equipment used as a countermeasure against electrostatic disturbance is an ionizer.

Since there are various types of ionizers and their characteristics and neutralization effects are different, it is necessary to understand and use the operation of the device and to investigate and review to select the appropriate device for the target electrostatic disturbance. The ionizer is classified into three types according to the ion generation method.

① Corona discharge type

By concentrating an electric field on the needle-shaped discharge electrode, the air is locally insulated, causing a corona discharge to generate air ions. When a (+) voltage is applied to the discharge needle, (+) ions are generated and (-) voltage When applied, (-) ions are generated. The corona discharge type ionizer can be divided into three types according to the method of applying high voltage to the discharge electrode part: an AC method, a DC method, and a pulsed DC method.

② radiation type

Radioactive isotopes such as polonium 210 emit alpha rays. Particles are helium nuclei composed of two protons and two neutrons, which ionize air molecules by colliding with them. When α-particles collide with air molecules, the air molecules eject their outer electrons and become positive ions. The released electrons are captured by other air molecules to form negative ions.

③ soft x-ray

As a type of electromagnetic wave with a very short wavelength, inelastic scattering occurs when photons collide with air molecules, and electrons are ejected from the air molecules, and the air molecules become positive ions. The ejected electrons are captured by separate air molecules and form negative ions.

The measurement items for the performance evaluation of the ionizer can be largely divided into four categories: Ion Balance/Offset Voltage, decay time (+/-), air flow, and amount of ions. Among them, discharge voltage, discharge time, and wind speed are designated as items to be measured in the standard, but standard test methods have not been established for the measurement of wind direction and ion amount. The time when the applied voltage of 1,000 V reaches 100 V using CPM (Charge Plate Monitor) is called Decay Time and can be calculated by subtracting T1 from measured T2. Figure 1 shows the decay time measurement method. .

To measure the performance of the ionizer, the charging plate to which the measurement method by the CPM (Charge Plate Monitor) recommended by the standard is applied is 150mm x 150mm. The total capacitance including is (20±2)pF

Currently, CPM (Charge Plate Monitor) using Oscillation Chopper type sensor is manufactured and sold. However, the measurement performance of the product has an error rate of less than 10%. Although many products have surface potential sensors using oscillation chopper type sensors and a number of static electricity measurement equipment, they have relatively large errors in measurement errors.

Korean Patent Registration No. 10-1629915 is a charge plate monitoring device, and the performance of the OCS (Oscilation Chopper Sensor) sensor shows the performance of the product.

In the performance evaluation of the ionizer, the evaluation is performed with the charge plate voltage (Ion Balance) and the decay time (Decay Time). In the case of most conventional electrostatic sensors distributed in Korea, most of them are products using surface potential sensors.

In order to measure the decay time, after the desired voltage is charged to the plate, the decay time by the ionizer is measured. However, the error of the conventional surface potential sensor increases due to the use environment and its own performance.

KR 10-1629915 B

The present invention has been proposed to solve the above technical problems, and monitors a charge plate having a network-based small charge plate capable of reducing measurement errors by using a voltage equalization circuit having a potential parallel to that of the charge plate. provide the device.

According to an embodiment of the present invention to solve the above problem, a charging plate including a top plate for collecting ions and a bottom plate as a counter electrode, and outputting a preset output voltage to the charging plate A high voltage generating unit for proportionally measuring the potential change of the charging plate, a voltage balancing circuit having a potential parallel to that of the charging plate, an analog-to-digital converter having the potential of the voltage balancing circuit as an input signal, and an analog-to-digital converter A charge plate monitoring device including an embedded data processing unit for collecting an output signal of a converter is provided.

In addition, in the present invention, it is characterized in that it further comprises a control computer that manages the database of the measurement data transmitted from the embedded data processing unit.

In the domestic market, most electrostatic measurement equipment consists of instruments utilizing surface potential sensors. However, it is not suitable for evaluating the performance of the ionizer. The reason is that the measurement of static decay time, which is one of the evaluation criteria, cannot be accurately evaluated.

To solve this problem, the charge plate monitoring device according to an embodiment of the present invention can reduce the measurement error to within 3% (30V) by using a voltage balancing circuit having a potential parallel to that of the charging plate.

1 is a diagram showing a method for measuring decay time (Decay Time)
2 is a block diagram of a charge plate monitoring device 1 according to an embodiment of the present invention.
3 is a design example and a live view of a charging plate
3a to 3c are detailed design examples of the charging plate
4 is an exemplary diagram of a high voltage drive circuit of a high voltage generating unit;
5 is an exemplary diagram of a reference voltage output circuit for implementing a voltage balancing circuit;
6 is an exemplary diagram of a voltage display circuit of a reference voltage output circuit and a voltage balance circuit;
7 is an exemplary diagram of a voltage distribution circuit of an analog-to-digital converter;
8 is an exemplary diagram of a noise removal circuit and a power shift circuit of an analog-to-digital converter.
9 is an exemplary diagram of a test measurement environment for measuring the potential of an electrification plate;

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings in order to describe in detail enough for those skilled in the art to easily implement the technical idea of the present invention.

FIG. 2 is a configuration diagram of a charge plate monitoring device 1 according to an embodiment of the present invention, FIG. 3 is a design example and a live view of a charging plate, and FIGS. 3A to 3C are detailed design examples of the charging plate. .

The charge plate monitoring device 1 according to the present embodiment includes only a simple configuration for clearly explaining the technical idea to be proposed.

2 to 3c, the charge plate monitoring device 1 includes a charging plate 100, a high voltage generator 200, a voltage equalization circuit 300, an analog-to-digital converter 400, and an embedded data processing unit 500. and a control computer 600.

The main operations of the charge plate monitoring device 1 configured as described above are as follows.

The charge plate monitoring device 1 is defined as a device used for performance evaluation of an electrostatic eliminator.

The charging plate 100 includes a top plate that collects ions and a bottom plate that is a counter electrode, and an insulator is provided between the top plate and the bottom plate. can

That is, the charging plate 100 is defined as a sensor that collects +/- ions generated from an electrostatic eliminator (ionizer) and displays the amount of charge through a measuring device.

After applying a high voltage of 1000V to the charging plate 100, the performance of the ionizer can be evaluated while measuring a decay time during which the voltage of the charging plate 100 decreases by the ionizer. A BNC connector may be connected to the charging plate 100 and may be configured to have a size of 25.4 mm x 25.4 mm.

The high voltage generator 200 outputs a preset output voltage to the charging plate 100 .

The high voltage generator 200 is preferably composed of a circuit having an output voltage range of at least +1,100V to -1,100V or more. That is, the high voltage generator 200 is configured to output ±1,100V voltage for measuring Decay Time (±1,000V -> ±100V).

The voltage balancing circuit 300 is configured to have a potential parallel to that of the charging plate 100 in order to proportionally measure a potential change of the charging plate 100 .

The analog-to-digital converter 400 converts an analog signal (voltage) into a digital signal by using the potential of the voltage balancing circuit 300 as an input signal.

The embedded data processing unit 500 collects digital output signals output from the analog-to-digital converter 400, and the control computer 600 manages the data transmitted from the embedded data processing unit 500 in a database. The embedded data processing unit 500 and the control computer 600 may be configured to exchange data through a wired or wireless communication network. For example, serial communication (RS-485, RS-232) may be used.

The control computer 600 may be connected to the plurality of embedded data processing units 500 through a network to receive and manage measurement data processed by the plurality of embedded data processing units 500 .

Since dozens of ionizers are installed in specific process equipment in the semiconductor process, many effects can be expected in terms of economy by enabling the performance evaluation of the ionizer to realize the activation of the smart factory in the control computer 600.

4 is an exemplary diagram of a high voltage drive circuit of a high voltage generator.

Referring to FIG. 4 , the high voltage drive circuit according to one example may be configured using a trigger method of a timer NE555 module. When the current flowing through the transistor Q13 exceeds a specific voltage, the timer NE555 module is triggered to switch the high voltage, and the output of the high voltage is controlled by the variable resistor VR4.

For reference, it may be configured to output a more accurate output voltage by adding a feedback circuit for the output voltage.

In addition, the high voltage transformer to be applied to the high voltage drive circuit can be composed of primary 15uH, secondary system voltage 6uH, high voltage winding 340mH, secondary output can be ±7.5V, ±1,200V or more.

5 is an exemplary diagram of a reference voltage output circuit for implementing a voltage balance circuit.

Referring to FIG. 5, when the voltage between the top plate collecting ions and the bottom plate, which is the counter electrode, is ±0.7V or more, the first step is to determine the polarity of the plate based on the output signal of the OPAMP. circuits can be constructed.

6 is an exemplary voltage display circuit diagram of a reference voltage output circuit and a voltage balance circuit.

Referring to FIG. 6 , a reference voltage output circuit and a high voltage circuit using an Op-amp are configured to configure a voltage switching circuit to express the ion voltage collected from the plate, and the output thereof can be checked.

Based on the output of the reference voltage, a high voltage output ±1,100v or higher voltage output was constructed using a transistor to balance the reference voltage. When the reaction speed of the transistor is balanced with the reference voltage, the voltage between the ground of the main power supply and the reference voltage circuit using the transistor can measure the voltage at which the voltage is in parallel with the ion voltage collected on the plate.

7 is an exemplary diagram of a voltage divider circuit of an analog-to-digital converter, and FIG. 8 is an exemplary diagram of a noise removal circuit and a power shift circuit of an analog-to-digital converter.

Referring to Figures 7 and 8, the output of the balance circuit is ±1,100v. However, in order to use the ADC input in the embedded system, the filter circuit and voltage distribution circuit must be configured. That is, a filter circuit design and a voltage divider circuit for appropriate noise removal are provided.

If a lot of noise is generated in the circuit, data with better performance can be secured by using the average value calculation program in the program of the embedded data processing unit 500 and applying it together with the filter circuit.

9 is an exemplary view of a test measurement environment for measuring a potential of an electrification plate.

Referring to FIG. 9 , power is supplied to a top plate to analyze data collected by a measurement circuit. The voltage supplied to the small charging plate 100 (DC Power Supplier) and the data detected by the measurement circuit were compared and reviewed, and the error of the measurement result was measured within ±0.2V on average.

During measurement, when there is a contact error between the measurement point and the signal ground, high voltage leakage of the system may occur, so a protection device and a circuit for removing noise may be additionally provided.

The charge plate monitoring device according to an embodiment of the present invention can reduce a measurement error to within 3% (30V) by using a voltage balance circuit having a potential parallel to that of the charging plate.

As such, those skilled in the art to which the present invention pertains will be able to understand that the present invention may be embodied in other specific forms without changing its technical spirit or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. The scope of the present invention is indicated by the following claims rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

100: battle plate
200: high voltage generator
300: voltage balancing circuit
400: analog digital converter
500: embedded data processing unit
600: control computer

Claims (2)

a charging plate including a top plate for collecting ions and a bottom plate serving as a counter electrode;
a high voltage generator outputting a preset output voltage to the charging plate;
a voltage balancing circuit having a potential parallel to that of the charging plate to proportionally measure a potential change of the charging plate;
an analog-to-digital converter using the potential of the voltage balancing circuit as an input signal; and
An embedded data processing unit for collecting an output signal of the analog-to-digital converter;
The voltage balancing circuit includes a reference voltage output circuit, but the reference voltage output circuit is configured to determine the polarity of the plate when the voltage between the top plate and the bottom plate is ±0.7V or more. A charge plate monitoring device comprising a circuit.
According to claim 1,
The charge plate monitoring device of claim 1, further comprising; a control computer that converts and manages the measurement data transmitted from the embedded data processing unit into a database.

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