KR20100067618A - Circuit pattern inspection device and circuit pattern inspection method thereof - Google Patents

Abstract

PURPOSE: An apparatus and a method for inspecting a circuit pattern are provided to detect a short circuit position on a conductive pattern by applying an inspection signal of one frequency with opposite wavelength to two conductive patterns which are shorted. CONSTITUTION: An inspection signal applying unit applies a first inspection signal and a second inspection signal to two adjacent conductive patterns formed on a substrate. A sensor moving unit(6) moves a sensing unit along an extended installation direction of a conductive pattern. A detector(5) outputs a detection signal by adding the reverse signals of the first and second inspection signals. A determining unit(16) determines the position of the conductive pattern below a preset threshold value by the reduction of the detection signal as the short failure position.

Description

Circuit pattern tester and circuit pattern test method {CIRCUIT PATTERN INSPECTION DEVICE AND CIRCUIT PATTERN INSPECTION METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit pattern inspection apparatus for detecting a short circuit defective position occurring in a circuit pattern formed in parallel and a circuit pattern inspection method thereof.

In general, a liquid crystal substrate of a liquid crystal display device has conductive patterns arranged in parallel in a straight line with the same fine line width for exchanging image signals or control signals, for example, for pixels arranged in a plurality of matrix shapes. Formed. In the manufacturing process, the defect inspection of a short circuit and a disconnection is performed about these electrically conductive patterns. Since this inspection has a fine line width and a large number of conductive patterns, electrical inspection such as conduction check is first performed instead of direct visual inspection.

As a method of this electrical inspection, Patent Document 1, for example, contacts probes made of metal to both ends of the conductive pattern, applies a test signal to the conductive pattern from the probe at one end side, and inspects the probe from the probe at the other end side. By detecting a signal, a contact inspection method (pin contact method) for conducting a conduction test of a conductive pattern or the like has been proposed. The application of the test signal is performed by contacting the tip of the probe to the terminals of the entire conductive pattern and sequentially passing a current through the conductive pattern. In this electrical inspection, it is determined that there is a disconnection failure when no inspection signal is detected from the conductive pattern of the inspection object, and that a short circuit failure is determined when the inspection signal is detected from a conductive pattern adjacent to the conductive pattern of the inspection object. do.

After conducting the electrical inspection, the conductive pattern in which the defect is detected is subjected to electrical inspection by moving the sensor along the pattern image, or visually inspected by using an optical microscope to specify a defective position on the conductive pattern. have.

[Patent Document 1] Japanese Patent Application Laid-open No. 62-269075

[Patent Document 2] Japanese Patent Application Laid-Open No. 2005-24518

In the above-described electrical inspection, when a defective position on the conductive pattern is specified, the probe is moved in contact or non-contact with these conductive patterns to detect a short circuit or disconnection from the change in the detection signal. In addition, in the case of specifying the defective position by visual observation, the image is taken while moving the camera and displayed on the monitor along the conductive pattern detected as defective, and the inspector judges.

The method of detecting a change in the detection signal while moving to a probe in contact with a conductive pattern that has been used in the prior art is concerned that damage to the pattern due to movement of the probe which is in contact with the miniaturization of the conductive pattern is likely to occur. The method of detection is preferred. As a technique for inspecting the inspection position in a non-contact manner, for example, Patent Document 2 discloses that a pattern is moved upward by using one AC inspection signal at one frequency or two AC inspection signals at different frequencies, thereby causing short circuit and disconnection. An inspection technique for inspecting is disclosed. In this inspection technique, the maximum voltage value is detected when the sensor is moved along the pattern and the sensor is positioned above the short circuit point of the pattern (see FIG. 10 in Patent Document 2). On the other hand, when the sensor moving above the disconnection point of a pattern is located, the inversion of a detection signal is detected (refer FIG. 11 in patent document 2).

In such a configuration, when using two different frequency test signals, an oscillation circuit must be provided for each, and two filters must be used to separate the detection signals even in the detection.

Therefore, this invention is a circuit pattern test | inspection apparatus and its circuit pattern test | inspection method which detect the short-circuit position on a conductive pattern by applying the test signal of one frequency whose waveform is opposite to two electrically conductive patterns shorted by the simple structure. The purpose is to provide.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a plurality of conductive patterns formed in a columnar shape on a substrate, wherein two adjacent conductive patterns are alternating current signals having the same frequency and the same waveform, and having 180 degrees out of phase with each other. A test signal applying unit for applying a first test signal and a second test signal to each sensor, and a sensor unit for capacitively coupling non-contact by spaced apart from each of the conductive patterns to detect the first test signal and the second test signal; A sensor moving part for moving the sensor part along the extending installation direction of the conductive pattern while being spaced apart from the conductive pattern by a predetermined distance, and the first test signal and the second test signal detected while the sensor part moves. A detection unit that adds an inverted signal and outputs it as a detection signal; and a threshold value less than or equal to a predetermined value by a decrease in the detection signal detected by the detection unit The circuit pattern inspection apparatus provided with the determination part which determines the position of the said conductive pattern which is made into the short circuit defective position of two adjacent conductive patterns is provided.

Moreover, the 1st test signal and the 2nd test signal which are the AC signal of the same frequency and the same waveform, and the phase shift | deviated 180 degree with respect to two adjacent conductive patterns among the some conductive pattern formed in the column shape on the board | substrate. Are applied to each of the two conductive patterns to detect the first and second inspection signals propagated through the two conductive patterns, and the phase of one of the detected detection signals or one of the inspection signals is inverted, and the other Provided is a circuit pattern inspection method for determining an inspection position at which an inspection signal and an inspection signal added together is equal to or less than a predetermined threshold value as a short-circuit failure position in the two conductive patterns.

According to the present invention, it is possible to provide a circuit pattern inspection apparatus which detects a short circuit position on a conductive pattern by applying a test signal of one frequency having opposite waveforms to two conductive patterns shorted in a simple configuration.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail with reference to drawings.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the example of block structure which shows the conceptual structure of the circuit pattern inspection apparatus which concerns on 1st Embodiment of this invention. In this embodiment, the probe contacts the conductive pattern to apply a test signal, and the sensor detects the test signal in a non-contact manner.

This circuit pattern inspection apparatus 1 is provided by capacitive coupling from an inspection signal applying unit 3 for applying an alternating inspection signal to a plurality of conductive patterns 2 formed in a columnar shape on a substrate and the conductive pattern 2. The sensor unit 4 for non-contact detection of the inspection signal, the detection unit 5 for performing signal processing on the inspection signal detected by the sensor unit 4 and outputting it as a detection signal, and the sensor unit 4 in three dimensions ( The XY surface serving as the substrate surface, the sensor moving unit 6 movable in the height adjustment Z-axis direction), the control unit 7 which performs control of the entire constituent unit and processing of the detection signal, and the detection result or user instruction It consists of the display part 8 to display, and the input part 9 which consists of a keyboard, a touch panel, etc. which input a user's instruction | indication, etc ..

In the present embodiment, the conductive patterns to be inspected are arranged linearly, for example, straight lines on the substrate (e.g., silicon substrate, glass substrate, etc.) and arranged in parallel at equal intervals with the same line width. In addition, if the sensor part mentioned later is equipped with the movement mechanism which can trace-trace along a conductive pattern, it does not need to be limited to the linear conductive pattern as shown in FIG.

The test signal applying unit 3 shifts the test signal generator 18 for generating an AC test signal (first test signal S1) having a predetermined frequency and amplitude from the test signal S1 by 180 degrees, that is, the phase. It consists of a phase shift part 19 which produces | generates the 2nd test signal S2 which inverted, and the 2 probes 23 and 24 which consist of metal for applying a test signal. These probes 23 and 24 are arranged side by side so as to be applied to the conductive pattern 2 to be inspected and the conductive pattern 2 adjacent thereto.

The inspection signal applying unit 3 applies the generated first inspection signal S1 to the conductive pattern 2a to be inspected, for example, from the probe 23 described later, and at the same time, by the phase shift unit 19. The second inspection signal S2 with the phase shifted is applied from the probe 24 described later to the conductive pattern 2b adjacent to the conductive pattern 2a to be inspected. These first test signal S1 and the second test signal S2 are signals of the same frequency (amplitude) and of the same waveform, and the second test signal S2 is 180 degrees out of phase with respect to the first test signal S1. The test signal is out of order.

The sensor part 4 is provided with the plate-shaped rectangular-shaped sensor electrodes 21 and 22 which have substantially the same width | variety as the line | wire width of the conductive pattern 2 at the support base at the same distance as the space | interval of a conductive pattern. These sensor electrodes 21 and 22 are arrange | positioned so that they may mutually oppose a conductive pattern and predetermined distance apart at the time of an inspection. As long as the sensor electrodes 21 and 22 can detect a test signal from the conductive pattern to be inspected and do not detect a test signal from adjacent conductive patterns, the shape, size, and the like need not be particularly limited.

The sensor moving part 6 is a moving mechanism for moving the sensor part 4 along the conductive pattern 2. Although the structure is not shown in figure, for example, the guide member along the extending direction (Y direction) of the conductive pattern 2, the movable part which supported the sensor part 4, and was provided in the guide member so that sliding was possible, and the movable part It is comprised by the drive source, such as a motor which pulls by a belt or a wire and slides. As a drive source, the structure which provided the linear motor directly in the guide member and integrated the movable part and the drive source may be sufficient. In addition, although not shown, the sensor moving part 6 is provided with the guide member and the movable part extended in the direction (X direction) which traverses the row of the conductive pattern 2, and moves the sensor part 4 to the Y direction. It is also possible to detect failure of disconnection and short circuit. That is, two guide members orthogonal to the X direction and the Y direction are provided so that the sensor unit 4 can move in two dimensions on the entire substrate surface. In addition, the sensor unit 4 is equipped with a distance measuring sensor, and according to the detected distance data, the sensor moving unit 6 moves the height (the conductive pattern 2 and the sensor electrode) of the sensor unit 4 to move. The height adjustment is performed so that the distances of the distances 21 and 22 are constant.

In addition, the sensor moving part 6 may mount the imaging mechanism which consists of an imaging element which picks up a detection location, and an imaging optical system, and can make a user visually.

The detection unit 5 removes unnecessary signal components including noise components from the amplifying circuit 11 which adds and amplifies the antiphase test signals detected by the sensor electrodes 21 and 22, respectively, and the amplified test signals. And a rectifying circuit 13 for rectifying the test signal passing through the filter and outputting a detection signal (analog signal) composed of smooth current voltage components. In addition, when the value of the test | inspection signal detected by the sensor electrodes 21 and 22 is small, and their addition value becomes a smaller value, each detected test signal is amplified as it is, it adds after performing a filter process, and adds The rectification of the teeth may be performed. In addition, when the test signal has a large ripple component due to the test environment or the test object, a smoothing circuit may be separately inserted at the output side of the rectifier circuit.

The detection signal by the detection part 5 is sent to the control part 7. The control unit 7 determines in advance the A / D conversion unit 14 that digitally processes the detection signal, the processing unit 15 having the arithmetic processing function and control function by the CPU, and the arithmetic processing detected signal. It is comprised by the determination part 16 which determines on a condition and determines a defective position (short position).

In addition, although this embodiment demonstrated the detection of the position of the short circuit location with respect to the conductive pattern in which the short circuit defect was already discovered, the circuit pattern inspection apparatus 1 has the presence or absence of the defect (short circuit and disconnection) of the first conductive pattern. It has a function of detecting. This applies a test signal to the target conductive pattern from the probe while moving across the column of the conductive pattern using the sensor unit, detects the test signal, and checks whether or not the detection signal is present and the detected signal value. In accordance with the degree of change, it is determined whether the conductive pattern is defective.

Next, with reference to FIG.2 (a)-(c), the principle to determine the defective position (short position) of the conductive pattern in this embodiment is demonstrated. FIG. 2A is a diagram schematically showing the positional relationship between the conductive pattern 2 and the sensor unit 4, and FIG. 2B is a diagram showing FIG. 2A as an equivalent circuit. (C) is a figure which shows the theoretical relationship between the sensor position on a conductive pattern, and a sensor output voltage. FIG. 2D is a diagram showing a relationship due to the actual measurement of the sensor position on the conductive pattern and the sensor output voltage.

Here, the conductive pattern 2a to be inspected is used, and the adjacent conductive pattern 2b shorted at the position P2 is used. The AC test signal S1 is applied to the conductive pattern 2a from the probe 23, and the AC test signal S2 is applied to the conductive pattern 2b from the probe 24. As described above, the AC test signal S1 and the AC test signal S2 are signals having the same frequency and the same waveform, and the phases are shifted by 180 degrees (the amplitude is inverted).

When the resistance component R1 of the conductive pattern 2a and the resistance component R2 of the conductive pattern 2b are approximately the same resistance value, the current I1 and the current I2 flowing in each conductive pattern are currents of the same current value (absolute value) with the inverted state. The sensor output decreases from the position P1 toward the position P2, and at position P2, I1 + I2 = 0. In actual detection, the phase of the sensor output of either one, for example, I2 is reversed, and the two sensor signals are in the same phase, and then the added value is obtained as a detection result.

This is because, at the position P1, the currents in the reverse direction via the position P2 flow in both of the conductive patterns 2a and 2b, but since the current value of the applied test signals S1 and S2 is larger, the sensor electrodes 21 and 22 are used. Each is detected as an output. However, as the sensor unit 4 moves toward the position P2, the detected sensor output decreases together, and at the position P2, the detected sensor output is theoretically obtained by the following equation. Is I = 0 (A), that is, output voltage 0 (V).

[Equation 1]

Even if it moves toward the position P3 after a short-circuit point, since the electric current of mutual test signals cancels each other, most test signals are not detected from the sensor electrodes 21 and 22. FIG. However, according to the actual measurement result, it may not become zero by the influence of the noise from the outside, etc., and may become constant at some minimum value.

The determination unit 16 determines the defective position (short position) by judging the calculated detection signal based on a predetermined condition. As the condition, for example, the position where the detected value is equal to or less than a predetermined threshold value is determined as a short-circuit point, compared with a predetermined value arbitrarily determined. The determination result is displayed on the display unit 8. In FIG.2 (c), it is determined that approximately 0V is a short circuit position. In practice, as shown in Fig. 2D, the position of the sensor output is sharply reduced and the position below the preset threshold is judged to be a short circuit position.

As described above, the present embodiment has two conductive patterns that are the inspection target and two conductive patterns that have the same frequency and the same waveform and are 180 degrees out of phase (inverted) with respect to the conductive pattern that is short-circuited by the solder bridge or the like. An inspection signal is applied to each, and the inspection portion is detected by moving the sensor portion above the conductive pattern in a non-contact manner. The detected test signals cancel each other as they approach the shorted point, and the detected values decrease sharply, and become approximately 0 depending on the situation. The location where the change of the detected value has occurred can be determined as the short circuit position. The waveform of the test signal may be not only a sine wave but also a square wave (pulse wave), and the waveform is not particularly limited as long as the phase of the phase is inverted and added to approximately zero. Moreover, also in frequency, what is easy to handle, such as a commercial frequency, is suitable, and it is more preferable if there exists a low cost component applicable to the frequency.

3 is a diagram illustrating a block configuration example showing a conceptual configuration of a circuit pattern inspection device according to a second embodiment.

In this embodiment, in addition to detecting a test signal from a conductive pattern in the above-described first embodiment in a non-contact manner, the probe on the application side applies a test signal in a non-contact manner with the conductive pattern. The configuration other than this is the same as that of 1st Embodiment mentioned above, attaches | subjects the same code | symbol as the code | symbol of the structural member shown in FIG. 1, and the detailed description is abbreviate | omitted. Moreover, also in this embodiment, after performing the defect inspection of a conductive pattern, detecting the position of the short circuit location with respect to the conductive pattern in which the short circuit defect was found is demonstrated, but the function which performs the first defect detection (short circuit and disconnection) is performed. Shall have.

The circuit pattern inspection device 1 of the present embodiment includes a test signal applying unit 31 for applying an AC test signal by capacitive coupling in a non-contact manner to a plurality of conductive patterns 2 formed on a substrate, and a sensor unit ( 4), the detection part 5, the sensor moving part 34, the control part 7, the display part 8, and the input part 9 are comprised.

In the present embodiment, the test signal applying unit 31 and the sensor moving unit 34 are different from the first embodiment described above.

The test signal applying unit 31 includes a test signal generation unit 18 for generating an AC test signal (first test signal S1) and a phase shift unit for generating a second test signal S2 in which the test signal S1 is inverted in phase. (19) and the application electrode part 31 which applies these test | inspection signals to the conductive pattern 2 of a test object non-contactedly.

In the application electrode portion 31, the application electrodes 32 and 33 having a width equal to or less than the width of the end of the conductive pattern or the electrode pad provided at the end thereof are spaced at the same interval as the arrangement interval of the conductive pattern 2. Is placed. The applied electrodes 32 and 33 have the same configuration as the sensor electrodes 21 and 22 except the size.

Like the sensor moving part 3 described above, the sensor moving part 34 is configured to be movable in three dimensions by using a guide member, a movable part, and a driving source, and the applied electrode part 31 and the sensor part 4 are moved. Synchronizing to move the conductive pattern while maintaining a uniform height in the direction crossing the conductive pattern (X direction), fixing the applied electrode portion 31 above the conductive pattern 2, and also moving the sensor portion 4 to the same conductivity It is comprised so that the upper direction along the pattern 2 can be moved, maintaining a uniform height.

The circuit pattern inspection apparatus configured as described above has the same effect as that of the first embodiment described above, and also applies the inspection signal to the conductive pattern 2 in a non-contact manner by using the application electrode portion 31, thereby providing a conductive pattern. The damage caused by the probe contact can be reduced. Moreover, since both the application electrode part 31 and the sensor part 4 are moved non-contacted by the moving mechanism, the application electrode for applying an inspection signal can be realized with at least two electrodes. Therefore, it becomes a simple structure with respect to the probe which requires the number equal to the number of electrically conductive patterns, For example, if a liquid crystal substrate for a large liquid crystal display screen is a test object, an apparatus cost can also be made low. In addition, even when the arrangement state (arrangement interval) of a conductive pattern is different, it can respond easily only by changing the program of a process part.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the example of block structure which shows the conceptual structure of the circuit pattern inspection apparatus which concerns on 1st Embodiment.

2A to 2D are diagrams for explaining the principle of determining a defective position of a conductive pattern.

FIG. 3 is a diagram showing a block configuration example showing a conceptual configuration of a circuit pattern inspection device according to a second embodiment. FIG.

<Explanation of symbols for the main parts of the drawings>

1: circuit pattern inspection device

2, 2a, 2b: conductive pattern

3, 31: inspection signal applying unit

4 sensor unit

5: detection unit

6, 34: sensor moving part

7: control unit

8: display unit

9: input unit

11: amplification circuit

12: bandpass filter

13: rectifier circuit

14: A / D converter

15 processing unit

16: judgment unit

18: test signal generator

19: phase shift unit

21, 22: sensor electrode

23, 24: probe

31: applied electrode portion

32, 33: applied electrode

Claims (4)

Among the plurality of conductive patterns formed in a columnar shape on the substrate, first and second test signals each having an AC signal having the same frequency and the same waveform and having a phase shift of 180 degrees with respect to two adjacent conductive patterns are respectively shifted. A test signal applying unit applied to the A sensor unit which is capacitively coupled to each of the conductive patterns in a non-contact manner to detect the first test signal and the second test signal; A sensor moving unit which moves the sensor unit along an extension installation direction of the conductive pattern in a state spaced apart from the conductive pattern by a predetermined distance; A detection unit which adds the inverted signal of the first test signal and the second test signal detected while the sensor unit is moved, and outputs it as a detection signal; The circuit pattern test | inspection provided with the determination part which determines the position of the said conductive pattern which became below the predetermined threshold by the decrease of the detection signal detected by the said detection part as the short-circuit defective position of two adjacent conductive patterns. Device. 2. The circuit pattern of claim 1, wherein the test signal applying unit includes at least two probes contacting a surface of an end portion of the conductive pattern to apply the first test signal and the second test signal. Inspection device. The test signal application unit according to claim 1, wherein the inspection signal applying unit has a width equal to or less than a width of an end portion of the conductive pattern, is disposed at an interval equal to an arrangement interval of the conductive pattern, and is spaced apart from above the conductive pattern to be non-contact. And at least two applying electrodes for capacitive coupling of the first test signal and the second test signal. Among the plurality of conductive patterns formed in a columnar shape on the substrate, first and second test signals each having an AC signal having the same frequency and the same waveform and having a phase shift of 180 degrees with respect to two adjacent conductive patterns are respectively shifted. Is authorized to Detecting first and second inspection signals propagating the two conductive patterns; The two conductive patterns may be used to invert the phase of one of the detected test signals or one of the detected test signals, and the test positions at which the value of the other test signal and the added test signal are equal to or less than a predetermined threshold. It determines with the short circuit defective position in the circuit pattern inspection method characterized by the above-mentioned.

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