JP2008281576A - Conductive pattern inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further simply perform reliable status inspection of a conductive pattern. <P>SOLUTION: The electric conduction pattern inspection device 10 has a sensor electrode 18 electrostatically coupled to one end of an inspection object pattern 14; and an electricity supply electrode 16 electrostatically coupled to the other ends of all conductive patterns 14. AC signal is applied to the inspection object pattern via the electric supply electrode 16 and the sensor electrode 18, and a current value which flows between a power source 20 and the sensor electrode 18 is detected. Based on the current value detected, existence of disconnection or short circuiting of the conductive pattern is detected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a conductive pattern inspection apparatus that inspects the state of a conductive pattern formed on a substrate.

  As a method for inspecting the state of a conductive pattern formed on a substrate, a method of bringing a pin probe into contact with both ends of a conductive pattern is conventionally known. In this method, a current is supplied to one pin probe and a voltage value is detected by the other pin probe. Then, by detecting the resistance value of the conductive pattern from the detected value, disconnection or short circuit of the conductive pattern is detected.

  However, this method has a problem that the conductive pattern is damaged due to the contact of the pin probe and the pin probe must be exchanged according to the pitch of the conductive pattern.

  Therefore, Patent Document 1 discloses a circuit pattern inspection apparatus that inspects the state of a conductive pattern in a non-contact manner. This feeds an AC signal to the conductive pattern from a power supply electrode capacitively coupled to one end of the conductive pattern. Then, this signal is detected by two types of sensor electrodes capacitively coupled to the other end of the conductive pattern, and the state of the conductive pattern is inspected based on the detected signal.

  According to this, since it can test | inspect without contact, a pattern is not damaged and it is not necessary to replace | exchange a probe according to a pitch.

JP 2002-365325 A

  By the way, in this inspection apparatus, a fed signal forms a current path from the feeding electrode to the conductive pattern and from the conductive pattern to the ground. Therefore, the voltage value induced on the conductive pattern is very small and easily affected by noise. Therefore, a highly reliable inspection could not be performed. Further, it is necessary to supply a high voltage signal, and measures such as discharge are required.

  Therefore, an object of the present invention is to provide a conductive pattern inspection apparatus that can perform a simple and highly reliable inspection.

  A conductive pattern inspection apparatus according to the present invention is a conductive pattern inspection apparatus for inspecting the state of a plurality of conductive patterns arranged on a substrate, and includes a sensor electrode electrostatically coupled to the inspection target pattern, and an inspection target pattern A pair of power feeding electrodes electrostatically coupled to a pair of conductive patterns located on both sides of the pattern placement direction, the pair of power feeding electrodes arranged adjacent to the sensor electrode, and the pair of power feeding electrodes through the pair of power feeding electrodes, An application means for supplying an inspection voltage having a phase different by 180 degrees to a pair of conductive patterns, and a defect detection means for detecting a short circuit of the inspection target pattern based on a change in voltage induced in the sensor electrode. And

  Here, the substrate is preferably a glass substrate used for a liquid crystal display panel or the like, but may be another substrate as long as a plurality of conductive patterns are arranged in a row. Good. The conductive pattern includes a conductive pattern called a gate pattern, a Cs pattern, a data pattern, or the like.

  According to the present invention, the application rate of the AC signal to the conductive pattern is improved, and even a low-voltage AC signal can be inspected with high reliability. Therefore, a more reliable inspection can be performed more easily.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, a conductive pattern disposed on a glass substrate used particularly for a liquid crystal display panel or the like is an inspection target. However, the present invention is not limited to this, and other conductive patterns may be used as long as they have columnar conductive patterns that are independent of each other.

  FIG. 1 shows a schematic side view of a pattern inspection apparatus 10 according to an embodiment of the present invention, and FIG. 2 shows a schematic top view.

  The apparatus 10 inspects the state of the conductive pattern 14 disposed on the glass substrate 12. The glass substrate 12 is fixed on the base 24 by suction means (not shown). On the glass substrate 12, conductive patterns 14 are arranged in a plurality of rows. In a normal state, the conductive patterns 14 are independent from each other and do not contact the adjacent conductive patterns 14. Moreover, it arrange | positions at substantially equal pitch and the position of the both ends is substantially the same. However, even a glass substrate having conductive patterns with unequal pitches or unequal lengths can be accommodated by adjusting the sizes of two types of electrodes described later.

  Two types of electrodes 16 and 18 are provided above the glass substrate 12 with a predetermined space therebetween. The power supply electrode 16 is a conductive plate that is positioned above one end of the conductive pattern 14 during inspection. This has a width that covers the ends of all patterns, and is electrostatically coupled to one end of all conductive patterns 14. However, the feed electrode 16 may have another width as long as it covers two or more patterns. In that case, the feeding electrode 16 may be moved in accordance with the movement of the sensor electrode 18 described later in the Y direction.

  The sensor electrode 18 is a conductive plate having a pattern width of approximately one. This is positioned above the other end of the conductive pattern 14 to be inspected in the presence or absence of a defect such as a disconnection or a short circuit. Further, when detecting the defect position, the defect moves along the conductive pattern 14 to be inspected (in the X direction). This sensor electrode 18 is also electrostatically coupled to the conductive pattern 14. The positional information of the sensor electrode 18 when moving is sent to and stored in a control device (not shown).

  The power source 20 is an AC power source for applying an AC signal to the conductive pattern 14. Both ends of the power source 20 are connected to the sensor electrode 18 and the power feeding electrode 16. Therefore, the AC signal generated and output from the power supply 20 is applied to the conductive pattern 14 via the sensor electrode 18 and the power supply electrode 16 that are electrostatically coupled to the conductive pattern 14.

  Here, the voltage applied to the conductive pattern 14 is divided by the ratio of the capacitance of the electrodes 16 and 18 with respect to the conductive pattern 14. Since the capacitance of the sensor electrode 18 and the power supply electrode 16 is substantially equal to one pattern, the voltage applied to the conductive pattern 14 is about one half of the applied AC voltage. Therefore, the voltage can be applied efficiently, and the voltage of the signal output from the power source 20 can be a low voltage such as several volts to several tens of volts.

  A current detector 22 that detects a current value is provided between the power supply 20 and the sensor electrode 18. The current value detected by the current detector 22 is sent to the control device and stored together with the position information of the sensor electrode 18. For example, a transformer can be used for the current detector 22, and the detection sensitivity can be adjusted by adjusting the number of turns of the coil to be wound. Alternatively, the voltage drop of the resistor may be detected by a differential amplifier.

  Next, the principle of conductive pattern inspection in the pattern inspection apparatus 10 will be described. When inspecting for the presence or absence of defects (disconnection or short circuit) in the conductive pattern 14, the sensor electrode 18 is positioned above one end of the inspection target conductive pattern 14, and the power supply electrode 16 is positioned above the other end. Is output. The output AC signal is applied to the conductive pattern 14 via the sensor electrode 18 and the power supply electrode 16.

  When the conductive pattern 14 is a normal pattern without disconnection and short circuit, a closed circuit including the conductive pattern 14 is formed. Therefore, a current of a predetermined value (greater than 0) corresponding to the voltage of the applied signal and the resistance in the circuit flows through the conductive pattern 14. This current value is detected by the current detector 22.

  On the other hand, in the case of the disconnection pattern 14a having the disconnection A, no current flows. Therefore, the current detector 22 detects a current value of almost zero. Further, in the case of the short-circuit pattern 14b having the short-circuit B, the overall resistance value is decreased, and a current higher than that of the normal conductive pattern 14 is detected.

  Therefore, by moving the sensor electrode 18 in a direction orthogonal to the pattern (Y direction in FIG. 2), a current value as shown on the right side of FIG. 2 is obtained. That is, when the sensor electrode 18 is on the normal conductive pattern 14, a predetermined current value is obtained. When the sensor electrode 18 is on the disconnection pattern 14a, a substantially zero current value is obtained. When the sensor electrode 18 is on the short circuit pattern 14b, the predetermined value is obtained. Each higher current value is detected.

  The current value and the position information of the sensor electrode 18 are sent to the control device, and the control device specifies a conductive pattern having a short circuit and a disconnection based on the information. That is, the conductive pattern electrostatically coupled to the sensor electrode 18 when a current value of approximately 0 is detected is disconnected from the conductive pattern, and the conductive pattern is electrostatically coupled to the sensor electrode 18 when a current value equal to or greater than a predetermined value is detected. The conductive pattern is detected as a short-circuit pattern.

  At this time, as described above, an alternating current signal is applied to the conductive pattern 14 via substantially the same capacitance at both ends, so that a high current value can be detected even when a low voltage signal is applied. Therefore, it is difficult to be affected by noise and the like, and an accurate inspection can be performed even at a low voltage. In addition, since the voltage is low, it is not necessary to take measures against discharge and the inspection can be performed easily. Furthermore, it is possible to simultaneously inspect for disconnection and short-circuiting by moving the sensor electrode 18 once in the direction orthogonal to the conductive pattern 14.

  Next, the principle of detecting the position of the defect will be described with reference to FIGS. FIG. 3 is a diagram illustrating the principle of disconnection position detection, and FIG. 4 is a diagram illustrating the principle of short circuit position detection. The current values detected by the current detector 22 are shown on the lower side of the figure, respectively.

  When detecting a disconnection position or a short-circuit position, the sensor electrode 18 is moved along the disconnection pattern 14a or the short-circuit pattern 14b.

  When the sensor electrode 18 is moved along the disconnection pattern 14a, a current value as shown in the lower side of FIG. 3 is detected. That is, while the sensor electrode 18 is in front of the disconnection A (on the left side in the figure), no current flows, so a value of almost 0 is detected. When the sensor electrode 18 exceeds the disconnection position, a predetermined current value is detected. Further, as the power supply electrode 16 is further approached, the overall resistance value decreases, and the current value increases. The current value and the position information of the sensor electrode 18 are sent to the control device, and the control device detects the disconnection position based on the information. That is, the position of the sensor electrode 18 when the current value changes from approximately 0 to a predetermined value is detected as the disconnection position.

  On the other hand, when the sensor electrode 18 is moved along the short-circuit pattern 14b, a current value as shown in the lower side of FIG. 4 is detected. That is, the current value increases gently while the sensor electrode 18 is in front of the short circuit B, and becomes almost constant when the short circuit B is exceeded. Then, when the sensor electrode 18 is further brought closer to the power supply electrode 16 side, a gentle increase is started again. In the control device, the position of the sensor electrode 18 when the inflection point from the gradual increase to the constant occurs is detected as the short-circuit position.

  In this way, the defect position can be specified by moving the sensor electrode along the defective conductive pattern and detecting the current value at that time.

  In this embodiment, the sensor electrode 18 is moved, but the glass substrate 12 may be moved. Further, the detection of the defect position may be performed after completion of the defect presence inspection for all patterns, or may be performed every time a defect pattern is detected.

  Next, a case where a common bar is used as a power supply electrode will be described.

  In general, one end of all conductive patterns may be connected to the conductive pattern 14 by a conductive plate called a common bar in order to prevent damage to the conductive pattern due to static electricity. In the case of such a glass substrate, this common bar can be used as a feeding electrode.

  Specifically, an AC signal is applied to the conductive pattern 14 via the sensor electrode 18 and the common bar 30 as shown in FIG. At this time, power supply to the common bar 30 may be performed using, for example, a 1-pin contact probe. Since the common bar 30 is electrically and physically connected to one end of all patterns, the common bar 30 performs the same function as the above-described power supply electrode.

  Therefore, when the sensor electrode 18 is moved in the Y direction, the current value detected by the current detector 22 is as shown on the right side of FIG. That is, a current value that is substantially 0 on the disconnection pattern 14a and greater than a predetermined value is detected on the short-circuit pattern 14b. When detecting the position of the disconnection A or the short circuit B, the sensor electrode 18 may be moved along a defective conductive pattern.

  Thus, by using the common bar 30 as a power supply electrode, pattern inspection can be performed more easily. In addition, since the power supply to the conductive pattern 14 can be more reliably performed, more accurate inspection can be performed.

  Next, another embodiment will be described.

  FIG. 6 is a schematic top view of a pattern inspection apparatus 10 according to another embodiment. In this pattern inspection apparatus 10, a pair of first electrodes 32 provided at both ends of the pattern and a pair of second electrodes 34 provided on both side patterns of the inspection target pattern are used as power supply electrodes. Further, defect inspection is performed based on the voltage value at the sensor electrode 36 provided on the inspection target pattern.

  The pair of first electrodes 32 are conductive plates positioned above both ends of the conductive pattern 14 during inspection, and function as power supply electrodes for disconnection inspection. The first electrode 32 has a width that covers the ends of all the patterns, and is electrostatically coupled to the ends of all the conductive patterns 14. However, the first electrode 32 may have another width as long as it covers three or more patterns including the inspection target pattern and the conductive patterns on both sides thereof. In that case, the first electrode 32 may be moved in accordance with the movement of the sensor electrode 36 described later in the Y direction.

  The pair of second electrodes 34 are conductive plates positioned above both side patterns of the inspection target pattern at the time of inspection, and function as power supply electrodes for short circuit inspection. The second electrode 34 has substantially the same width as one pattern, and is electrostatically coupled to the conductive patterns 14 on both sides of the inspection target pattern. The second electrode 34 can be moved in accordance with the movement of a sensor electrode 36 described later.

  The sensor electrode 36 is a conductive plate having approximately one pattern width. This is positioned at a position shifted by a predetermined distance from the center of the conductive pattern 14 to be inspected in the presence or absence of a defect such as a disconnection or a short circuit. Further, when the defect position is detected, the defect moves along the conductive pattern 14 to be inspected. This sensor electrode 36 is also electrostatically coupled to the conductive pattern 14. The position information of the sensor electrode 36 at this time is sent to and stored in a control device (not shown).

  The first power supply 40 and the second power supply 42 generate and output alternating signals of the first frequency f1 and the second frequency f2, which are different frequencies. Both ends of the first power source 40 are connected to the pair of first electrodes 32, and both ends of the second power source 42 are connected to the pair of second electrodes 34. Therefore, the AC signals of the two frequencies f1 and f2 generated and output from the first power supply 40 and the second power supply 42 are applied to the conductive pattern 14 via the pair of first electrodes 32 and second electrodes 32, respectively. .

  Here, the capacitance formed between the pair of first electrodes 32 and the conductive pattern 14 is substantially equal at both ends. Therefore, the voltage of the first frequency f1 applied to the conductive pattern 14 is about one half of the applied AC voltage. Thereby, since a voltage can be applied efficiently, the voltage of the signal output from the power supply 40 may be a low voltage such as several volts to several tens of volts. In addition, since the capacitance formed by the pair of second electrodes 34 is substantially equal on both sides, the voltage of the signal output from the second power source 42 may be a low voltage such as several volts to several tens volts. Become. Both the first power source 40 and the second power source 42 are preferably grounded using a transformer.

  A voltage value detector 44 that detects a voltage value for each frequency is connected to the sensor electrode 36. This is composed of an amplifier 46 that amplifies the AC signal detected by the sensor electrode 36 and a discrimination filter 48 for extracting a signal for each frequency. Thereby, the voltage value for every frequency is detectable. A phase detector (not shown) that can determine the polarity of the detected signal is also provided.

  Next, the principle of conductive pattern inspection in the pattern inspection apparatus 10 will be described.

  When inspecting the presence or absence of a defect (disconnection or short circuit) in the conductive pattern 14, the sensor electrode 36 is positioned at a position shifted from the center of the conductive pattern 14 to be inspected, and an AC signal is output from the first power supply 40. This AC signal is applied to the conductive pattern 14 via the pair of first electrodes 32.

  Since the first power supply 40 is grounded at the midpoint, the voltage of the signal applied via the pair of first power supplies 40 is 180 degrees out of phase at both ends. Therefore, the voltage value induced in the normal conductive pattern 14 becomes almost zero at the center of the pattern due to cancellation, and gradually increases or decreases as it approaches both ends. Therefore, when the conductive pattern 14 is normal without disconnection and short circuit, the sensor electrode 36 is located at a position shifted from the center of the conductive pattern 14, and therefore a voltage of a predetermined value is applied to the sensor electrode. This voltage value is detected by a voltage value detector 44.

  On the other hand, in the case of the disconnection pattern 14 a having the disconnection A, there is no cancellation of the reverse-phase voltage applied from the left and right of the conductive pattern 14. Therefore, in the sensor electrode 36 shifted from the center position, the voltage value applied from one end is detected as it is (without phase cancellation). This voltage value is higher than the voltage value detected by the normal conductive pattern 14. Therefore, if a voltage having a frequency f1 higher than a predetermined voltage value is detected, it can be detected as a disconnection pattern.

  On the other hand, when inspecting the presence or absence of a short circuit, the sensor electrode 36 is positioned at a position shifted from the center of the inspection target conductive pattern 14, and an AC signal having the second frequency f <b> 2 is output from the second power source 42. When the conductive pattern 14 is normal without a short circuit, a voltage having a predetermined value of frequency f2 is applied to the sensor electrode 36. This voltage value is detected by a voltage value detector 44. On the other hand, in the case of the short-circuit pattern 14b with the short circuit B, the voltage applied from both sides is unbalanced, so that a voltage having a value higher than usual is detected. Therefore, if a voltage having a frequency f2 higher than a predetermined voltage value is detected, it can be detected as a short-circuit pattern.

  Therefore, by moving the sensor electrode 36 in a direction orthogonal to the pattern (Y direction in FIG. 6), a voltage value as shown on the right side of FIG. 6 is obtained. That is, the voltage value of the frequency f1 is a predetermined value when the sensor electrode 36 is on the normal conductive pattern 14, and a voltage value higher than the predetermined value is detected when the sensor electrode 36 is on the disconnection pattern 14a. On the other hand, the voltage value of the frequency f2 is a predetermined voltage value when the sensor electrode 36 is on the normal conductive pattern 14. When the sensor electrode 36 is on the short-circuit pattern 14b and only one of the pair of second electrodes 34 is on the other short-circuit pattern 14b, a voltage value higher than a predetermined value is detected.

  The current value and the position information of the sensor electrode 18 are sent to the control device, and the control device identifies a defective conductive pattern based on the information. That is, when a voltage value having a frequency f1 greater than or equal to a predetermined value is detected, a pattern electrostatically coupled to the sensor electrode 36 is detected as a disconnection pattern. Further, when a voltage value of a frequency f2 that is equal to or higher than a predetermined value is detected, a pattern that is electrostatically coupled to the sensor electrode 36 is detected as a short-circuit pattern.

  Note that the detection of the disconnection and the presence or absence of a short circuit may naturally be performed simultaneously. Since the voltage value detector 44 has the discrimination filter 48 for detecting the voltage value for each frequency, each voltage value can be detected even when the voltages of f1 and f2 are applied to the conductive pattern 14. Therefore, by moving the sensor electrode 36 and the second electrode 34, it is possible to simultaneously detect a short circuit and a disconnection.

  At this time, as described above, an AC signal is applied to the conductive pattern 14 through substantially the same capacitance at both ends, so that the signal application rate increases. Therefore, even if the signal is a low voltage, a sufficiently detectable voltage is induced. Even if the signal is a low voltage, it is difficult to be affected by noise and the like, and an accurate inspection is possible. In addition, since the voltage is low, it is not necessary to take measures such as discharge, and the inspection can be performed easily. Further, both the disconnection A and the short circuit B can be detected simultaneously by moving the sensor electrode 36 and the second electrode 34 once in the direction orthogonal to the conductive pattern 14.

  When the sensor electrode is just at the disconnection position or between the disconnection, the sensor electrode cannot detect the voltage value. However, in that case, a voltage value of 0 is detected instead of a predetermined voltage value. Therefore, a conductive pattern in which a voltage value of approximately 0 is detected can be detected as a disconnection pattern.

  In this embodiment, the power source is a midpoint ground, and the sensor electrode is positioned at a position shifted from the center. This is because a voltage value of 0 is reliably detected as abnormal. However, even if this is not done, since there is some change in the voltage value between the normal pattern and the defective pattern, the changed pattern may be detected as a defective pattern.

  Next, the principle of detecting the position of disconnection or short circuit will be described with reference to FIGS.

  FIG. 7 is a diagram illustrating the principle of disconnection position detection, and FIG. 8 is a diagram illustrating the principle of short circuit position detection. The voltage values detected by the voltage value detector 44 are respectively shown on the lower side of the figure.

  When detecting the disconnection position, the sensor electrode 36 is moved along the disconnection pattern 14a. In that case, a voltage value as shown in the lower side of FIG. 7 is detected. That is, while the sensor electrode 36 is in front of the disconnection A (left side in the figure), the voltage value of the signal applied from one side (left side in the figure) is detected. When the sensor electrode 36 exceeds the disconnection position, the phase changes by 180 degrees, and the voltage value of the signal applied from the opposite side (right side in the figure) is detected. Therefore, the polarity of the signal detected by the sensor electrode 36 is discriminated by the phase detector, and the position where the polarity is inverted can be detected as the disconnection position. The detection result and the position information of the sensor electrode 36 are sent to the control device, and the control device detects the disconnection position based on the information. That is, the position of the sensor electrode 36 when the voltage phase changes by 180 degrees is detected as the disconnection position.

  On the other hand, when the sensor electrode 36 is moved along the short-circuit pattern 14b, a voltage value as shown on the lower side of FIG. 8 is detected. That is, the voltage of the sensor electrode 36 is a predetermined voltage value before the short circuit B, and the balance is lost as it approaches the short circuit position. Therefore, when the sensor electrode 36 comes above the short circuit position, the peak rapidly rises and falls. Then, when the short circuit B is passed, the voltage value returns to the predetermined value again. That is, the peak of the voltage value is detected at the position of the short circuit B. The control device detects the position of the sensor electrode 36 when the peak voltage value is detected as a short-circuit position.

  As described above, the defect position can be specified by moving the sensor electrode along the defective conductive pattern and detecting the voltage value at that time.

  In this embodiment, the sensor electrode 36 is moved, but the glass substrate 12 may be moved. Further, the detection of the defect position may be performed after completion of the defect presence inspection for all patterns, or may be performed every time a defect pattern is detected. Further, when a common bar is connected to the conductive pattern 14, the common bar may be used as the first electrode.

  Next, a pattern inspection apparatus 10 which is another embodiment will be described.

  The pattern inspection apparatus 10 is used particularly for inspection of a gate pattern and a Cs pattern disposed on a glass substrate used for a liquid crystal display panel.

  In the manufacturing process of the liquid crystal display panel, first, a gate pattern and a Cs pattern are simultaneously disposed on the glass substrate 12. A plurality of gate patterns are conductive patterns arranged in rows on a glass substrate. The Cs pattern is a conductive pattern arranged alternately in a row. Since the distance between the gate pattern and the Cs pattern is extremely small (for example, several tens of μm), a short circuit is likely to occur. A pattern inspection apparatus 10 particularly suitable for this short circuit inspection will be described.

  FIG. 9 shows a schematic top view of the pattern inspection apparatus 10.

  On the glass substrate 12 to be inspected, a gate pattern 50 and a Cs pattern 52 are disposed adjacent to each other. The gate pattern 50 and the Cs pattern 52 are both connected at one end by common bars 54 and 58.

  Above the glass substrate 12, a gate electrode 56 and a Cs electrode 60 are provided as power supply electrodes. The sensor electrode 62 is provided on the conductive pattern to be inspected.

  The gate electrode 56 is a conductive plate provided at one end of the gate pattern 50 opposite to the gate common bar 54 at the time of inspection. This has a width that covers one end of the entire gate pattern 50, and is electrostatically coupled to one end of the entire gate pattern 50. However, other widths may be used as long as they cover one or more gate patterns including the gate pattern to be inspected. In that case, the sensor electrode 62 described later may be moved in accordance with the movement in the Y direction.

  The Cs electrode 60 is a conductive plate provided at one end of the Cs pattern 52 opposite to the Cs common bar 58 at the time of inspection. This is also electrostatically coupled to the Cs pattern 52 and has a width that covers one end of the entire Cs pattern 52. Of course, other widths may be used as long as they cover one or more Cs patterns including the target Cs pattern.

  The sensor electrode 62 is a conductive plate positioned above the gate pattern 50 or the Cs pattern 52 to be inspected at the time of inspection, and is electrostatically coupled to these. The sensor electrode 62 can move in the Y direction or the X direction at the time of inspection, and the position information at that time is sent to and stored in a control device (not shown).

  The sensor electrode 62 is provided with a voltage value detector 76, and the voltage value at the position of the sensor electrode 62 is detected. The detected voltage value is sent to the control device together with the position information of the sensor electrode 62 and stored.

  The voltage value detector 76 includes an amplifier 78 that amplifies an AC signal detected by the sensor electrode 62 and a discrimination filter 80 that extracts a signal for each frequency. Thereby, the voltage value for every frequency is detectable. A phase detector (not shown) that can determine the polarity of the detected signal is also provided.

  An AC signal having a frequency f1 is applied to the gate pattern 50 via the gate electrode 56 and the gate common bar 54. This is applied by a gate power source 64 having one end connected to the gate electrode 56 and the other end connected to the gate common bar 54. On the other hand, an AC signal having a frequency f2 is applied to the Cs pattern 52 by the Cs power source 66 via the Cs electrode 60 and the Cs common bar 58. The gate power supply 64 and the Cs power supply 66 are both grounded at the midpoint.

  Next, the detection principle of the short circuit A and the disconnection B between the gate pattern 50 and the Cs pattern 52 will be described. In this case, the sensor electrode 62 is positioned on the gate pattern 50 or Cs pattern 52 to be inspected. At this time, the sensor electrode 62 is preferably located at a position slightly deviated from the center of the pattern.

  In this state, AC signals of frequencies f1 and f2 are applied from the gate power supply 64 and the Cs power supply 66. The voltage value for each frequency in the sensor electrode 62 is detected by the voltage value detector 76.

  At this time, in the normal gate pattern 50 without the short circuit A or the disconnection B, the voltage of the frequency f1 (frequency of the gate power supply) is induced, but the voltage of the frequency f2 (frequency of the Cs power supply) is not induced. In addition, in the normal Cs pattern 52, a voltage of frequency f2 (frequency of the Cs power supply) is induced, but a voltage of frequency f1 (frequency of the gate power supply) is not induced.

  On the other hand, in the gate pattern 50a having the short circuit A, the voltage f2 is also induced together with the voltage f1. Further, even in the Cs pattern 52a having the short circuit A, voltages having both the frequency f1 and the frequency f2 are induced. That is, it can be determined that a short circuit has occurred in the gate pattern in which the voltage of frequency f2 (frequency of the power source for Cs) is induced and the Cs pattern in which the voltage of frequency f1 (frequency of the power source for gate) is induced.

  Next, the presence / absence detection of the disconnection B will be described. When detecting the presence or absence of the disconnection B, attention is paid to the detected voltage value. If the gate pattern 50 or the Cs pattern 52 is a normal pattern, a predetermined voltage value is detected. This is because reverse phase voltages are applied from both sides of the pattern. Since the voltage phase cancels out, the voltage value becomes almost zero at the center of the pattern and gradually increases (lowers) as it approaches both ends. Therefore, a predetermined voltage value (0 or more) is detected at the position of the sensor electrode 62 slightly deviated from the center.

  On the other hand, in the case of the broken patterns 50b and 52b, since there is no phase cancellation, a voltage value higher than a predetermined value is detected. That is, a pattern in which a voltage value higher than a predetermined value is detected can be detected as the disconnection patterns 50b and 52b.

  When the sensor electrode is just at the disconnection position or between the disconnection, the sensor electrode cannot detect the voltage value. However, in that case, a voltage value of 0 is detected instead of a predetermined voltage value. Therefore, a conductive pattern in which a voltage value of approximately 0 is detected can be detected as a disconnection pattern.

  By moving the sensor electrode 62 in the Y direction, a voltage value as shown on the right side of FIG. 9 is obtained. That is, when the sensor electrode 62 is on the Cs pattern 52a or the gate pattern 50a where the short circuit A occurs, a predetermined value is detected for both the voltage f1 and the frequency f2.

  On the other hand, when it is on the gate pattern 50b where the disconnection occurs, the voltage value of the frequency f1 becomes high. Further, when the line is on the Cs pattern 52b where the disconnection occurs, a voltage value having a high frequency f2 is detected.

  The voltage value and the position information of the sensor electrode 62 are sent to the control device, and the control device detects a short-circuit pattern and a disconnection pattern based on the information. That is, the Cs pattern 52 from which the voltage at the frequency f1 is detected or the gate pattern 50 from which the voltage at the frequency f2 is detected is detected as a short-circuit pattern. A pattern in which a voltage value higher than a predetermined value or 0 is detected is detected as a disconnection pattern.

  Next, a case where a defect position is detected will be described. When detecting the defect position, the sensor electrode 62 is moved along the defect pattern.

  When the sensor electrode 62 is moved along the short-circuit patterns 50a and 52a, the maximum voltage value is detected when the sensor electrode 62 comes above the short-circuit A (FIG. 10). On the other hand, when the sensor electrode 62 is moved along the disconnection patterns 50b and 52b, the phase is inverted by 180 degrees when the sensor electrode 62 comes above the disconnection B (FIG. 11). In the control device, the position of the short circuit or the disconnection is detected based on the voltage value (phase detection result) and the position information of the sensor electrode 62.

  Thus, according to the present embodiment, the signal application rate is high because the AC signal is applied from both ends of the pattern. Therefore, the detected signal is hardly affected by noise, and a highly accurate inspection is possible. In addition, since it is possible to inspect even with a low-voltage AC signal, it is possible to easily inspect without requiring countermeasures against discharge.

  Further, it is possible to easily detect a short circuit between the gate pattern and the Cs pattern that are likely to cause a short circuit. Furthermore, by moving the sensor electrode 62 in the Y direction, it is possible to perform a short circuit and a disconnection inspection at the same time.

  In the present embodiment, the glass substrate 12 with the gate common bar 54 is used, but the glass substrate 12 without the gate common bar 54 may naturally be used. When the gate common bar 54 is not provided, a pair of gate electrodes 56 that are electrostatically coupled to the ends of the gate pattern may be provided at both ends of the gate pattern 50.

  Next, another embodiment will be described with reference to FIG. This is also a pattern inspection apparatus 10 suitable for detecting a short circuit between the gate pattern and the Cs pattern.

  This is to detect the presence or absence of a defect based on the current value.

  In the pattern inspection apparatus 10, the sensor electrode 62 is connected to the middle point between the gate power source 64 and the Cs power source 66.

  Next, the presence / absence inspection for defects (short circuit or disconnection) using the pattern inspection apparatus 10 will be described.

  In this case, the sensor electrode 62 is positioned on the gate pattern 50 or Cs pattern 52 to be inspected. Then, an AC signal is applied to the gate pattern 50 and the Cs pattern 52 through the electrodes 56 and 60 and the common bars 54 and 58, respectively. At this time, the sensor electrode 62 is connected to the midpoint between the two power sources 64 and 66. In this case, two circuits IR and IL are formed by a line connecting the sensor electrode 62 and the power sources 64 and 66. The values of the currents flowing through the IR and IL are almost equal and reverse in a normal pattern without the short circuit A and the disconnection B. Therefore, in the case of a normal pattern, the current detectors 68 and 70 detect a substantially zero current value.

  However, when the sensor electrode 62 is on the pattern 50a, 52b in which the short circuit A occurs, the voltage balance is lost (the current values at IR and IL become unequal), so both current detectors 68, At 70, a high current value is detected. The current value at this time is stored in the control device together with the position information of the sensor electrode 62.

  A high current value is also detected when there is a disconnection B. However, in this case, the current detector for a pattern different from the pattern in which the disconnection B occurs has a current value of almost zero. That is, when the gate pattern is disconnected, the gate current detector 68 detects a high current value, and the Cs current detector 70 detects a substantially zero current value. On the other hand, when the Cs pattern is disconnected, the Cs current detector 70 detects a high current value, and the gate current detector 68 detects a substantially zero current value.

  Therefore, when a high current value is detected by both the gate current detector 68 and the Cs current detector 70, a short circuit occurs, and a high current value is obtained only by either the gate current detector 68 or the Cs current detector 70. When is detected, it can be determined that the wire is disconnected.

  Therefore, by moving the sensor electrode 62 in the Y direction, it is possible to perform a short circuit and a disconnection inspection at the same time.

  When specifying the disconnection position, the sensor electrode 62 may be moved along a pattern having a disconnection. Since voltages having opposite phases are applied from both sides of the pattern, the phases differ from each other at the disconnection position. Therefore, the disconnection position can be specified by observing the phase change with a phase detector (not shown) or the like. Further, since the current value is substantially 0 at the disconnection position, a position where a voltage value of approximately 0 is detected may be specified as the disconnection position.

  Thus, according to the present embodiment, the signal application rate is high because the AC signal is applied from both ends of the pattern. Therefore, the detected signal is hardly affected by noise, and a highly accurate inspection is possible. In addition, since inspection can be performed even with a low-voltage AC signal, it is possible to easily perform inspection without requiring measures such as discharge.

  Further, it is possible to easily detect a short circuit between the gate pattern and the Cs pattern that are likely to cause a short circuit.

  Next, another embodiment will be described with reference to FIG. This is for more easily detecting a short circuit between the gate pattern and the Cs pattern.

  This inspection apparatus 10 detects a short circuit between the gate pattern 50 having the lead electrode 82 and the Cs pattern 52 connected at one end by the common bar 58.

  Both ends of a power supply 64 that outputs and generates an AC signal are connected to a sensor electrode 62 and a common bar 58. The sensor electrode 62 is a conductive plate having substantially the same width as that of the extraction electrode. When a short circuit is detected, the sensor electrode 62 is positioned above the extraction electrode 82 connected to the conductive pattern to be inspected. Combined.

  One end of the power supply 64 is connected to the common bar 58 and the other end is connected to the sensor electrode 62. A current detector 68 for detecting a current value is provided between the common bar 58 and the power source 64.

  Next, the principle of short circuit detection in the pattern inspection apparatus 10 will be described. When detecting the presence or absence of a short circuit, the sensor electrode 62 is positioned above the extraction electrode 82 connected to the gate pattern 50 to be inspected. Then, an AC signal is output from the power supply 64. One end of the power supply 20 is connected to the common bar 58 and the other end is connected to the sensor electrode 62.

  At this time, the common bar 58 is electrically and physically connected to the Cs pattern 52. Further, the sensor electrode 62 is electrically connected to the gate pattern 50 through the extraction electrode 82. Therefore, when the gate pattern 50 and the Cs pattern 52 are not short-circuited, no current flows. Therefore, when the sensor electrode 62 is on a normal pattern, a current value of almost zero is detected.

  On the other hand, when the gate pattern 50 and the Cs pattern 52 are short-circuited, a current flows through the short-circuit portion A. Therefore, when the sensor electrode 62 is on a short-circuited pattern, a high current value is detected.

  Therefore, when the sensor electrode 62 is moved in the Y direction, a current value as shown on the right side of FIG. 13 is detected. That is, in the case of the normal gate pattern 50, a high current value is detected in the case of the gate pattern 50a in which the short-circuited gate pattern 50a is almost zero. The control device detects the presence or absence of a short circuit based on the current value at this time and the position information of the sensor electrode 62. That is, the gate pattern 50 electrically connected to the sensor electrode 62 when a high current value is detected is detected as a short-circuited pattern.

  Thus, according to the present embodiment, it is possible to detect the presence or absence of a short circuit with a single power source.

1 is a schematic side view of a pattern inspection apparatus that is an embodiment of the present invention. It is a schematic top view of the pattern inspection apparatus which is an Example of this invention. It is a figure which shows the principle of a disconnection position detection. It is a figure which shows the principle of a short circuit position detection. It is a schematic top view of the pattern inspection apparatus which is another Example. It is a schematic top view of the pattern inspection apparatus which is another Example. It is a figure which shows the principle of a disconnection position detection. It is a figure which shows the principle of a short circuit position detection. It is a schematic top view of the pattern inspection apparatus which is another Example. It is a figure which shows the principle of a short circuit position detection. It is a figure which shows the principle of a disconnection position detection. It is a schematic top view of the pattern inspection apparatus which is another Example. It is a schematic top view of the pattern inspection apparatus which is another Example.

Explanation of symbols

  10 pattern inspection device, 14 conductive pattern, 16 feeding electrode, 18, 36, 62 sensor electrode, 20, 40, 42, 64, 66 power supply, 22 current detector, 30 common bar, 32 first electrode, 34 second electrode, 44 voltage detector, 50 gate pattern, 52 Cs pattern, 56 gate electrode, 60 Cs electrode, 82 extraction electrode.

Claims (1)

A conductive pattern inspection apparatus for inspecting the state of a plurality of conductive patterns arranged on a substrate,
A sensor electrode electrostatically coupled to the pattern to be inspected;
A pair of power supply electrodes electrostatically coupled to a pair of conductive patterns located on both sides of the pattern arrangement direction of the inspection target pattern, a pair of power supply electrodes disposed adjacent to the sensor electrode;
Applying means for supplying an inspection voltage having a phase different by 180 degrees to the pair of conductive patterns via the pair of power supply electrodes;
Defect detection means for detecting a short circuit of the inspection target pattern based on a change in voltage induced in the sensor electrode;
A conductive pattern inspection apparatus comprising:

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