KR20080092522A - Inspection apparatus of a circuit substrate - Google Patents

Abstract

An inspection apparatus of a circuit board is provided to inspect a short-circuit of a fine pattern by applying AC power through a pin probe block at one side of the fine pattern and measuring an electrical variation through a capacitive non-contact sensor at the other side of the fine pattern. A capacitive non-contact sensor(50) measures voltage at one end of a pattern electrode(15) in a non-contact method. A plurality of pin probes(40) are in contact with the pattern electrode at the other end of the pattern electrode. A selector(30) selects the pin probes. A control unit(60) applies AC power to the pin probes selected by the selector and determines a short-circuit of the pattern electrode in contact with the selected pin probes based on output voltage of the capacitive non-contact sensor.

Description

Inspection device for circuit boards {INSPECTION APPARATUS OF A CIRCUIT SUBSTRATE}

1 to 2 are diagrams showing an inspection apparatus of a circuit board according to the present invention.

Figure 3 is an exemplary use of the inspection apparatus of the circuit board according to the present invention.

4 is a view showing a waveform measured by the inspection apparatus of the circuit board according to the present invention.

   -Explanation of symbols for the main parts of the drawings-

10: circuit board 15: pattern electrode

20: AC power supply 30: selector

40: pin probe 50: capacitive non-contact sensor

60: control unit 70: display unit

80: key input unit

The present invention relates to an inspection apparatus for a circuit board, and more particularly, an electrical change value applied by an AC power supply through a pin probe block on one side of a fine pattern printed on the circuit board and measured by a capacitive non-contact sensor on the other side. The present invention relates to a circuit board inspection apparatus capable of inspecting a short circuit through a fine pattern.

Currently used image display devices include a cathode ray tube (CRT), a liquid crystal display (LCD), a plasma display panel (PDP), and the like, which are flat panel display devices.

Among the image display devices, the cathode ray tube has superior performance to other devices in terms of image quality and brightness. However, there are disadvantages in that they are not suitable for applications requiring a large screen because they are bulky and heavy.

On the other hand, the flat panel display device has an advantage that the volume and weight is very small compared to the cathode ray tube, and its use is gradually increasing, and research on the display device as a next generation display device is being actively conducted.

In general, PDP (Plasma Display Panel) is neon by putting a gas such as Ne + Ar, Ne + Xe between the upper glass and the lower glass and the glass sealed by the partition between them It refers to an electronic display device that emits light to use as display light.

Accordingly, the plasma display displays various characters or patterns by forming a discharge intersection between the vertical pattern electrodes and the horizontal pattern electrodes of the upper glass and the lower glass that face each other by discharging cells.

Therefore, PDP has been widely used for FA (factory automation) because it is possible to display large size with clear light emission, but now it is widely used for OA (office automation) such as personal computer with small size, light weight and high performance of display device. As display panel is not only high display quality but also fast response speed, demand is increasing rapidly as it is adopted as wall-mounted TV.

In addition, since liquid crystals are easy to handle and have inherent characteristics in which the arrangement of crystals changes depending on whether or not an external electric field is present, display elements using liquid crystals, for example, ferroelectric liquid crystal devices (FLCDs) and twisted nematic (TN) -LCDs. , STN (Super Twisted Nematic) -LCD, Thin Film Transistor (TFT) -LCD, Plastic (LCD), Electro Luminescence (EL).

In general, driving driver ICs for driving such flat panel display panels are directly mounted in a chip on glass (COG) form or a tape carrier package (TCP) pre-assembled in a flexible PCB (FPC) or tape substrate (TS). To be mounted.

In the case of 42-inch PDP, the line width and pitch of one electrode pattern are 50 μm and 300 μm, respectively, and the electrode pattern pitch of TFT-LCD panel is also about 70 μm. Electrode patterns on circuit boards with ICs are also becoming finer and more multi-pinned.

As the electrode patterns formed on the TS circuit board are miniaturized and multi-pinned, the contact probes cannot be sufficiently spaced to press-contact the both ends of the pattern electrodes. Circuit board is inspected by a non-contact method.

In this non-contact inspection apparatus, one side of the pattern electrode contacts a plurality of pin probes, and the other side of the pattern electrode is disposed with a capacitive non-contact sensor to selectively input an inspection signal to the pattern electrode through the plurality of pin probes, and to perform electrostatic Open circuit inspection is performed using the values measured at the capacitive non-contact sensor.

The short circuit test performs a short circuit test by measuring resistance between adjacent pin probes in a plurality of pin probes.

As such, when the short circuit of the pattern electrode is inspected by the resistance between the pattern electrodes, a measuring device capable of measuring a few MΩ is needed to check the short circuit caused by fine contaminants between the patterns. AC inductance change due to the change in dielectric constant due to the problem that can not be easily detected.

The present invention was created to solve the above problems, an object of the present invention is to apply an AC power supply through the pin probe block on one side of the fine pattern printed on the circuit board and to measure through the capacitive non-contact sensor on the other side The present invention provides an inspection apparatus for a circuit board capable of inspecting a short circuit of a fine pattern through an electrical change value.

The circuit board inspection apparatus according to the present invention for achieving the above object is a circuit board inspection apparatus for inspecting a short circuit to the pattern electrode of the circuit board, the electrostatic for measuring the voltage in a non-contact at one end of the pattern electrode The capacitive type non-contact sensor, a plurality of pin probes which are pressed in contact with the pattern electrode at the other end of the pattern electrode, a selector for selecting the plurality of pin probes, and a plurality of pin probes are selected through the selector to apply AC power. And a controller configured to determine a short circuit of the pattern electrode in contact with the selected pin probe based on the output voltage measured by the capacitive non-contact sensor.

In the present invention, the selector is characterized by grounding a plurality of unselected pin probes.

In the present invention, the selector is characterized by plotting a plurality of unselected pin probes.

In the present invention, the capacitive non-contact sensor is characterized in that it is in a fixed position.

In the present invention, the capacitive non-contact sensor is characterized in that it corresponds to all of the pattern electrode of the circuit board.

In the present invention, the control unit is characterized in that it is determined that the short-circuit when the voltage measured by the capacitive contactless sensor is measured higher than the normal value.

According to the present invention, the capacitive type non-contact sensor is fixed to one end of the pattern electrode of the circuit board, and the capacitive electrode is applied when the AC power is applied while selecting a plurality of pin probes contacting the pattern electrode of the other end through the selector. If a high value is measured by judging the change of the voltage value measured from the type non-contact sensor, the short circuit can be checked by judging that it is a short circuit.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings, and the same parts as in the prior art use the same reference numerals and names. In addition, the present embodiment is not intended to limit the scope of the present invention, but is presented by way of example only and those skilled in the art will be capable of many modifications within the technical spirit of the present invention.

1 and 2 are block diagrams showing an inspection apparatus of a circuit board according to the present invention.

As shown here, a capacitive type non-contact sensor 50 for measuring a voltage in a non-contact manner at one end of the pattern electrode 15 printed on the circuit board 10 and a pattern at the other end of the pattern electrode 15 A plurality of pin probes 40 in pressure contact with the electrode 15, a selector 30 for selecting the plurality of pin probes 40, and a plurality of pin probes 40 are selected through the selector 30. The control unit 60 and the control unit for determining a short circuit of the pattern electrode 15 in contact with the selected pin probe 40 on the basis of the output voltage measured by the capacitive non-contact sensor 50 while applying the AC power source 20. The display unit 80 for displaying the operation state and the measurement state of the 70, and the key input unit 90 for inputting a command to the control unit 70.

An unselected pin probe among the plurality of pin probes 40 in the selector 30 may be kept in a floating state as shown in FIG. 1 to contact the pattern electrode 15 for short-circuit inspection. It is also possible to keep the plurality of pin probes 40 that are not in the ground state.

Figure 3 is an exemplary use of the inspection apparatus of the circuit board according to the present invention.

The circuit board 10 shown here is a tape substrate (TS), and the pattern electrode 15 is continuously formed on the tape, and a driving IC (not shown) for driving the panel is mounted at the center thereof.

In this circuit board 10, the capacitive non-contact sensor 50 is fixed on the pattern electrode 15 in the center where the driving IC is to be mounted, and the plurality of pin probes 40 are pressed by the other side of the pattern electrode 15, respectively. In this state, the AC power source 20 is selectively applied to the pattern electrode 15 selectively through the selector 30.

The waveform measured by the inspection apparatus of such a circuit board is shown in FIG.

At this time, after applying the AC power supply 10 to the normal pattern electrode 15 by the pin probe 40 as shown in (a), the voltage value VPP_N measured by the capacitive contactless sensor 50 may be determined as a normal value. When the pattern electrode 15 is shorted with the adjacent pattern electrode 15 as shown in (b), the pattern electrode 15 contacted by the pin probe 40 and the shorted pattern electrode 15 are connected to one pattern electrode ( 15, the surface area of the pattern electrode 15 is increased, and the impedance due to the capacitance between the pattern electrode 15 and the capacitive type non-contact sensor 50 is reduced, and thus the pattern electrode 15 is reduced. The total impedance, which is the sum of the impedance of the impedance and the capacitance between the pattern electrode 15 and the capacitive contactless sensor 50, is reduced, so that the value measured by the capacitive contactless sensor 50 is greater than the normal value. Large VPP_S value is measured.

In this way, the capacitive non-contact sensor 50 is fixedly positioned at one side of the pattern electrode 15 to correspond to the plurality of pattern electrodes 15, and the plurality of pin probes 40 contacting the pattern electrode 15 at the other side are selectors. When the AC power source 20 is selectively applied through 30 to measure the voltage by the AC power source 20 through the capacitive type non-contact sensor 50, the voltage is higher than the voltage value measured by the normal pattern electrode 15. Is determined to be short-circuited and displayed.

In addition, a control command is input through the key input unit 90 to control the processing state of the control unit 70.

As described above, the present invention applies an AC power supply through a pin probe block on one side of a fine pattern printed on a circuit board, and checks a short circuit of the fine pattern through an electrical change value measured by a capacitive non-contact sensor on the other side. There is an advantage to this.

Claims (6)

In the circuit board inspection apparatus for inspecting a short circuit to the pattern electrode of the circuit board, A capacitive non-contact sensor for measuring a voltage in a non-contact manner at one end of the pattern electrode; A plurality of pin probes which are in pressure contact with the pattern electrode at the other end of the pattern electrode; A selector for selecting the plurality of pin probes, A control unit which selects the plurality of pin probes through the selector and applies an AC power, and determines a short circuit of the pattern electrode in contact with the selected pin probe based on the output voltage measured by the capacitive contactless sensor; Inspection device for a circuit board comprising a. 2. The apparatus of claim 1, wherein the selector grounds the plurality of unselected pin probes. The apparatus of claim 1, wherein the selector floats the plurality of pin probes that are not selected. 2. The apparatus of claim 1, wherein the capacitive non-contact sensor is in a fixed position. The apparatus of claim 1, wherein the capacitive non-contact sensor corresponds to a plurality of pattern electrodes of the circuit board. The apparatus of claim 1, wherein the controller determines that the voltage is shorted when the voltage measured by the capacitive contactless sensor is measured to be higher than a normal value.

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