WO2006078045A1

WO2006078045A1 - Circuit pattern inspection device and method thereof

Info

Publication number: WO2006078045A1
Application number: PCT/JP2006/301077
Authority: WO
Inventors: Hiroshi Hamori; Shuji Yamaoka; Shogo Ishioka
Original assignee: Oht Inc.
Priority date: 2005-01-19
Filing date: 2006-01-18
Publication date: 2006-07-27
Also published as: TW200632351A; JP4417858B2; TW201323901A; KR20070097113A; KR101175384B1; JP2006200992A; TWI407126B; CN101107535A

Abstract

There are provided a circuit pattern inspection device and method thereof capable of detecting the open state of a conductive pattern on a substrate. A power supply unit (12) for supplying an inspection signal in a non-contact way is arranged at one end of the conductive pattern and an open sensor (13) for detecting the inspection signal in a non-contact way is arranged at the other end of the conductive pattern. Furthermore, a noise sensor (19) is arranged in a non-contact way on a conductive pattern located at a distance of several patterns from the aforementioned conductive pattern and at the end of the same side as the open sensor (13). A signal containing the inspection signal and a noise detected by the open sensor (13) and a signal containing only noise not mixed with the inspection signal detected by a noise sensor are inputted to a differential amplifier (20), where the noise as a signal of the same phase component is removed. Thus, it is possible to surely inspect the conductive patterns arranged on a string shape on the substrate in a non-contact way.

Description

Description: Circuit pattern inspection apparatus and method

The present invention relates to a circuit pattern inspection apparatus and method, and more particularly, to a circuit pattern inspection apparatus and method that can inspect the quality of a conductive pattern formed on a glass substrate. Background art

As a typical method for inspecting a circuit pattern formed on a substrate, a pin contact method conventionally used is, for example, as described in Patent Document 1, for a substrate to be inspected. Metal pin probes are set up at all terminals, and electrical signals are sent to the conductive pattern via these probes. Therefore, there is an advantage that a good S / N ratio (signal-to-noise ratio) can be obtained for the inspection signal, but there is a risk of damaging the product to be inspected and its pattern.

This pin contact type inspection confirms that the inspection signal supplied to the conductive pattern to be inspected has normally passed through the conductive pattern. In addition, the inspection probe is connected to the conductive pattern adjacent to the conductive pattern to be inspected. There is also a method for determining the short-circuit state between the conductive pattern to be inspected and the adjacent pattern by determining whether a signal is also detected from the other end of the adjacent pattern. is there.

Patent Document 1 Japanese Patent Application Laid-Open No. 6 2-2 6 9 0 7 5

In addition to the pin contact method described above, the pin signal is supplied only to the inspection signal supply side for supplying and detecting the inspection signal to the conductive pattern to be inspected. There is a non-contact / contact combination method in which the probe is brought into direct contact and the inspection signal is detected in a non-contact state via capacitive coupling between the conductive pattern and the sensor on the other end side. Furthermore, a non-contact method in which a continuity test is performed in a non-contact state on both the signal supply side and the detection side via capacitive coupling has been used.

However, in a field where an inspection system for inspecting circuit patterns is installed, various equipment and devices are usually operating around the system, so they become noise sources and There is a lot of external noise. In such an environment, common-mode noise is constantly superimposed on the ground line. Servo motors used by the inspection system itself are also sources of noise. Conventional inspection systems, especially those that employ the non-contact method described above, handle very weak signals. For example, when conducting open detection of a conductive pattern, the quality of the pattern is determined based on a slight level difference between the detection signal level when the conductive pattern is not open and the detection signal level when there is an open location. Judgment is being made. At this time, not only the external noise is applied to the pattern to be inspected but also superimposed on the measurement signal, which adversely affects the stability and accuracy of the pattern inspection. As a result, it becomes difficult to distinguish between the sensor detection signal and noise, and a problem arises in terms of the reliability of the detection result.

Therefore, since conventional inspection apparatuses continuously detect signals from adjacent conductive patterns, it is impossible to avoid various noises from appearing on the detection signal. It is softly removed using a differentiation circuit.

In this way, noise countermeasures are very important for improving the accuracy of inspections. Therefore, the prevention of external noise and the outflow of noise to the outside of the device Even if various filters are installed for the purpose of prevention, the multiple response patterns cannot be scanned at high speed due to the slow response speed of the filter. Therefore, the influence on the inspection speed and inspection time becomes large, so it is not possible to add a fill evening.

Furthermore, even if only the stage or sensor head on which the test object is placed is connected to the ground, the ground level fluctuates due to noise, so the effect on the inspection is further increased. Disclosure of the invention

The present invention has been made in view of the above-described problems. An object of the present invention is to provide a circuit pattern inspection apparatus and method that can improve the accuracy of detecting a conductive pattern even in a noisy environment. It is.

As a means for achieving this object and solving the above-mentioned problems, for example, the following configuration is provided. That is, the present invention is a circuit pattern inspection apparatus for inspecting the state of a conductive pattern arranged on a substrate, and a signal supply means for supplying an inspection signal to a first part of a conductive pattern to be inspected. A first detection means capable of detecting a first signal from a second portion of the conductive pattern to be inspected, and a second from a conductive pattern at least 4 to 5 patterns apart from the conductive pattern to be inspected. A second detection means capable of detecting a signal of the first signal, a difference means for obtaining a difference between the first signal and the second signal, and a change in the difference signal obtained by the difference means. And an identification means for identifying pass / fail.

The present invention also provides a circuit pattern inspection apparatus for inspecting the state of a conductive pattern arranged on a substrate, the signal supply means for supplying an inspection signal to a first part of the conductive pattern to be inspected, and the inspection Target conductive pattern First detection means capable of detecting the first signal from the second part of the sensor and second detection capable of detecting the second signal from the conductive pattern separated from the conductive pattern to be inspected by a predetermined distance. Means, difference means for obtaining a difference between the first signal and the second signal, and identification means for identifying the quality of the conductive pattern based on a change in the difference signal obtained by the difference means. It is characterized by this.

For example, the difference means removes the second signal that is the noise signal from the first signal in which the noise signal is superimposed on the inspection signal. Further, the identification means identifies a disconnection state of the conductive pattern based on the signal from which the noise signal has been removed.

For example, further comprising: means for positioning and moving the signal supply means, the first detection means, and the second detection means so as to sequentially scan the conductive pattern to be inspected. .

For example, by the scanning, the inspection signal is supplied to the conductive pattern and the inspection signal is detected from the conductive pattern in the vicinity of the tips of all the patterns at one end of the conductive pattern. . In addition, for example, the signal supply means includes a plate member facing the conductive pattern at a constant interval, and supplies the inspection signal in a non-contact manner through capacitive coupling between the plate member and the conductive pattern. For example, each of the first detection means and the second detection means includes a plate member facing the conductive pattern at a constant interval, and through capacitive coupling between the plate member and the conductive pattern. It is characterized by detecting signals without contact.

Furthermore, as another means for solving the above-mentioned problem, for example, the following configuration Prepare for the completion. That is, the present invention is a circuit pattern inspection method in a circuit pattern inspection apparatus for inspecting the state of a conductive pattern arranged on a substrate, and a step of supplying an inspection signal to a first part of a conductive pattern to be inspected And a first detection step for detecting a first signal from a second portion of the conductive pattern to be inspected, and a conductive pattern that is at least 4 to 5 away from the conductive pattern to be inspected. A second detection step for detecting the second signal, a difference calculation step for obtaining a difference between the first signal and the second signal, and a change in the difference signal obtained in the difference calculation step. And an identification step for identifying whether the pattern is good or bad.

Furthermore, the present invention is a circuit pattern inspection method in a circuit pattern inspection apparatus for inspecting the state of a conductive pattern arranged on a substrate, and supplies an inspection signal to a first part of the conductive pattern to be inspected A first detection step of detecting a first signal from a second portion of the conductive pattern to be inspected, and a second signal from a conductive pattern spaced a predetermined distance from the conductive pattern to be inspected A second detection step for detecting; a difference calculating step for obtaining a difference between the first signal and the second signal; and whether the conductive pattern is good or bad based on a change in the difference signal obtained in the difference calculating step. And an identification step for identifying. For example, in the difference calculating step, the second signal that is the noise signal is removed from the first signal in which a noise signal is superimposed on the inspection signal. Further, for example, the identifying step is characterized in that the disconnection state of the conductive pattern is identified based on the signal from which the noise signal has been removed.

For example, the signal supply unit, the first detection unit, and the second detection unit are further configured to sequentially scan the conductive pattern to be inspected. A step for positioning and moving the step is provided.

For example, by the scanning, the inspection signal is supplied to the conductive pattern and the inspection signal is detected from the conductive pattern in the vicinity of the tips of all the patterns at one end of the conductive pattern. . For example, the signal supply means includes a plate member facing the conductive pattern at a constant interval, and supplies the inspection signal in a non-contact manner through capacitive coupling between the plate member and the conductive pattern. To do.

In addition, for example, each of the first detection unit and the second detection unit includes a plate member that is opposed to the conductive pattern at a constant interval, and is not connected via capacitive coupling between the plate member and the conductive pattern. A signal is detected by contact. Brief Description of Drawings

FIG. 1 is a block diagram showing the overall configuration of a substrate inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of signal measurement results in the substrate inspection apparatus according to the present embodiment.

FIG. 3 is a diagram equivalently showing a measurement circuit of the substrate inspection apparatus according to the present embodiment.

FIG. 4 is a diagram showing an example of a noise signal waveform and a measurement signal waveform in which noise is superimposed on the inspection signal.

FIG. 5 is a flowchart showing an inspection procedure in the substrate inspection apparatus according to the present embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. To do. FIG. 1 is a block diagram showing the overall configuration of the substrate inspection apparatus according to the present embodiment. The inspection target of the substrate inspection apparatus shown in FIG. 1 is, for example, a liquid crystal display panel or an evening type panel. Here, a large number of conductive patterns 2 a to 2 arranged in rows on a glass substrate 3. Check h for pass / fail (disconnected state of conductive pattern and presence / absence of short circuit between patterns). These conductive patterns are, for example, row-shaped conductive patterns in the above-described panel before bonding, and for example, chromium, silver, aluminum, ITO, etc. are used as the conductive material.

Note that these conductive patterns 2a to 2h to be inspected have a configuration in which both ends are independent from each other and separated from adjacent conductive patterns as shown in FIG. The inspection target is not limited to the conductive pattern having such a configuration. For example, it is possible to inspect the quality of a common pattern (comb-like pattern) in which one end of the pattern is connected to each other. Further, the pattern may be a curved pattern instead of a line. In the board inspection apparatus shown in FIG. 1, the control unit 15 is, for example, a microprocessor that controls the entire apparatus, and comprehensively controls the inspection sequence. In R O M 18, control procedures including a board inspection procedure described later are stored as a computer program. R A M I 7 is a memory used as a work area for temporarily storing control data, inspection data, and the like.

One end of the conductive pattern to be inspected (conductive pattern 2a in the example of substrate inspection shown in Fig. 1) is a power supply unit 1 capable of supplying an AC inspection signal of a predetermined frequency to the conductive pattern 2a in a non-contact manner. 2 is positioned, and the other end of the conductive pattern 2 a is an open sensor 1 for detecting whether the pattern is good or not in a non-contact manner, that is, whether the pattern is in an open state (also called a disconnected state). 3 is arranged. Furthermore, the open sensor 13 is connected to the adjacent conductive pattern (4 patterns away from the conductive pattern 2 e in the example shown in FIG. 1) at a predetermined distance (several patterns) away from the conductive pattern 2 a. A noise sensor 19 is placed on the same end as the one where it is placed. In this board inspection apparatus, the noise sensor 19 and the open sensor 13 are the same in size, thickness, etc., and the ground resistance is also in the same state.

In the board inspection device shown in Fig. 1, for example, noise originating from other devices and mecha-sound noise of the inspection device are external noise 1 1 a to 1 1 c from various directions at various levels. Will come in. These noises affect not only the specific patterns of the conductive patterns 2a to 2h, but also the patterns, and these patterns flow as noise currents.

Therefore, in the substrate inspection apparatus according to the present embodiment, in order to detect the noise current flowing in the pattern, in addition to the open sensor 1 3, the pattern in which the open sensor 1 3 is arranged and a predetermined interval (for example, 4 to 5 pattern intervals) A noise sensor 19 is arranged in a non-contact manner at the end of a conductive pattern that is far away. In the example shown in FIG. 1, the noise current of the conductive pattern 2 e is detected by the noise sensor 19.

The distance between the noise sensor 1 9 and the open sensor 1 3 can be reduced by the differential amplifier 2 0 placed immediately after the open sensor 1 3 and the noise sensor 1 9 to eliminate the influence of external noise and the like on the detection signal. Set as follows. Specifically, the optimum distance between the noise sensor 19 and the open sensor 13 varies depending on the size of the substrate inspection device itself, the pattern interval of the conductive pattern to be inspected, the pattern width, the material, etc. As an initial value, keep at least 4-5 patterns apart, and adjust as necessary.

The weak signals detected by the open sensor 1 3 and noise sensor 1 9 Amplified by a differential amplifier (amplifier) 20. The amplifier 20 is composed of, for example, an operational amplifier (op amp) or the like in order to amplify a minute signal with a predetermined amplification degree. In the present embodiment, the amplifier 20 is arranged immediately after the open sensor 13 and the noise sensor 19, thereby eliminating the influence of external noise and the like on the detection signal itself.

The power supply unit 12 is connected to a signal generation unit 10 that is an oscillator of the inspection signal. In this embodiment, for example, a high-frequency signal of 20.0 kHz is supplied to the power supply unit 12. Is output. Further, as described above, the power feeding unit 12 includes a flat plate plate for supplying an AC signal to the conductive pattern 2 in a non-contact manner. Therefore, the inspection signal is supplied to the conductive pattern through capacitive coupling between the power feeding unit 12 and the conductive pattern. Then, the inspection signal supplied to the conductive pattern reaches the open sensor 13 through the capacitive coupling between the conductive pattern and the open sensor 13.

The drive unit 16 receives the control signal from the control unit 15 and moves the entire stage 14 on which the inspection target is mounted at a predetermined speed in a predetermined direction, thereby supplying the power supply unit 1 2 and the open sensor 1. 3 and the noise sensor 19 can sequentially scan the conductive pattern to be inspected in a non-contact state. Therefore, the drive unit 16 moves the stage 14 in a predetermined direction on the m order.

In this embodiment, it is described that the stage 14 on which the inspection object is placed is moved. Instead of moving the stage 14, for example, the power feeding unit 12, the open sensor 13, and the noise A unit that integrates the sensor 19 may be moved in a predetermined direction so that a conductive pattern or the like to be inspected can be sequentially scanned.

In other words, power feeding unit 1 2, open sensor 1 3 and noise sensor 1

9 is arranged at one end of the conductive pattern or in the vicinity thereof as described above. However, for example, the drive control of the stage 14 is performed so as to move in the direction indicated by the arrow in FIG. In this way, the conductive patterns 2a to 2h arranged in a row on the substrate 3 are sequentially scanned, and their open states are individually inspected.

An output signal from the amplifier 20 is sent to the signal processing unit 21. The signal processing unit 21 performs a conversion process such as a waveform process for converting the amplified AC signal into a DC level signal, or an analog signal into a digital signal. Then, the control unit 15 compares the result obtained by processing by the signal processing unit 21 with a reference value set in advance, and determines whether or not the processing result is equal to or greater than the reference value. The determination result is sent from the control unit 15 to the display unit 25.

The display unit 25 is composed of, for example, CRT, a liquid crystal display, and the like, and visually displays in a format that allows the inspector to understand the quality of the inspection target (conductive pattern) that is the determination result sent from the control unit 15. If there is a defect in the conductive pattern, the position of the conductive pattern on the substrate is also displayed. The display of the inspection result is not limited to the visible display, and may be output in a format such as sound. Also, visual display and sound may be mixed.

Next, the inspection principle in the substrate inspection apparatus according to this embodiment will be described. As described above, the open sensor 13 is capacitively coupled to the conductive pattern to be inspected, and detects the inspection signal (alternating current signal) flowing through the conductive pattern as the strength of the detection signal level. For this reason, the power supply unit 1 2 moves in the direction of the arrow shown in Fig. 1, and the open sensor 1 3 moves in the same direction by the same distance. Extract changes.

When the power feeding unit 12 is scanned at the positions facing each conductive pattern, an inspection signal proportional to the corresponding area between the flat plate plate of the power feeding unit 12 and the conductive pattern can be supplied to the conductive pattern. Then, the conductive path to which the inspection signal is supplied If there is no disconnection (open state) in the turn, the inspection signal is detected by the open sensor 1 3, but when the power feeding unit 1 2 is between the conductive patterns by scanning, the inspection signal supplied to the conductive pattern is The output of the open sensor 1 3 decreases because it becomes negligible. In other words, the voltage level detected by the open sensor 13 decreases (for example, see Figure 2).

In addition, when there is an open part in the conductive pattern to be inspected, the inspection AC signal supplied from the power supply unit 1 2 does not reach the open sensor 1 3 and is detected by the open sensor 1 3 as described later. The voltage level decreases. For this reason, if a large drop in the output voltage level from the open sensor 13 is detected, it can be determined that there is a break in the conductive pattern at that position.

On the other hand, paying attention to noise coming to the inspection board from the outside, those noises are applied to all the conductive patterns including the conductive pattern to be inspected, so the open sensor 13 is supplied from the power feeding unit 12 Both the detected inspection signal and noise will be detected. On the other hand, since the inspection signal does not flow through the conductive pattern immediately below the noise sensor 19, it detects only the noise on the conductive pattern.

Therefore, in the board inspection apparatus according to the present embodiment, as shown in FIG. 1, the signal detected by the open sensor 13 from the inspection target pattern (this signal contains both inspection signals and noise) and The signal detected by the noise sensor 19 from the conductive pattern to which no inspection signal is supplied (only noise) is input to the positive input terminal (+) and negative input terminal (-) of the differential amplifier 20 for example. .

Since these noises are included in all conductive patterns including the conductive pattern to be inspected as described above, they become in-phase component signals with respect to the positive and negative input terminals of the differential amplifier 20. So, by differential amplifier 2 0 These differences are taken and noise is removed from the detection signals from the sensors 13. The principle of noise removal using a differential amplifier, open sensor, etc. will be described later using mathematical formulas.

Therefore, as shown in Fig. 1, an open sensor 13 is arranged, and the normal voltage detection value (that is, how the continuous signal in a non-defective product changes) is measured in advance, and a voltage different from that in the inspection process. If the value (signal change) is obtained, it can be determined that the conductive pattern is open. In this way, it is possible to accurately detect the presence or absence of disconnection of the conductive pattern with a simple configuration.

FIG. 2 shows an example of the inspection result in the substrate inspection apparatus according to the present embodiment. The vertical axis is the output voltage (m V p p) from the sensor, and the horizontal axis is the movement distance (/ m) of the sensor (or stage). Fig. 2 (a) shows the measured waveform when the output of the sensor (open sensor 1 3) is not passed through the differential amplifier, and Fig. 2 (b) shows the detection output by the open sensor 1 3. This is the output voltage waveform when the noise signal is removed by the differential amplifier.

As shown in Fig. 2 (a), it is difficult to identify the defective part from the signal waveform with the noise superimposed on it, but with the symbols A, B, C, D, and E in Fig. 2 (b). In the area shown, a significant waveform change (decrease in signal level) was detected. In this way, by arranging the differential amplifier 2 0 immediately after the open sensor 1 3 and the noise sensor 1 9 to eliminate the influence of external noise etc. on the detection signal, the normal and open locations of the conductive pattern (conductive The detection results differ greatly depending on whether the pattern is disconnected. Therefore, it can be seen that the defective part can be easily identified and recognized in the substrate inspection apparatus according to the present embodiment.

Note that the measurement conditions of the waveform shown in Fig. 2 are the gears between the sensor and the conductive pattern. In this case, the sensor is set to 50 jum, the moving speed of the sensor is 30 mm, second, the applied voltage is 3 220 V, and the distance between the sensors is 1550 mm.

Next, noise removal in the differential amplifier 20 will be described in detail using mathematical expressions. FIG. 3 equivalently shows a measurement circuit of the substrate inspection apparatus according to the present embodiment including the differential amplifier 20. FIG. 4 (a) shows an example of the noise signal waveform, and FIG. (b) shows an example of a measurement signal waveform in which noise is superimposed on the inspection signal.

In FIG. 3, _{V l} is a noise signal, v ₂ is a measurement signal, resistance Ri is the resistance of noise sensor 19, and resistance R ₂ is the resistance of open sensor 13. Now, assuming that the voltage at point P is v ₃ , all the current to the negative input terminal (one) flows through the feedback resistor R _f , so ii = if, that is,

Vein ~ ^V 3 3- ^V out ("1)

Is established.

Also, the voltage v _{s at} point Q is υ _ς = (υ- +, 2)

c ^m

It becomes.

The voltage between point P and point Q is virtually 0, that is, v ₃ = v _8, so

It becomes.

From these equations (3) and (4),

Is established.

Therefore, the output voltage v from Equation (5). Organizing _ut , υ,

It becomes.

In equation (6) above,

If R _s = R _f ,

Thus, the noise signal V i can be removed from the measurement signal v ₂ . That is, only the noise signal is reduced from the measurement signal due to the common-mode rejection ratio (CMRR) of the differential amplifier 20. Next, an inspection procedure and the like in the substrate inspection apparatus according to this embodiment will be described. FIG. 5 is a flowchart showing an inspection procedure in the substrate inspection apparatus according to the present embodiment. In step S1 of FIG. 5, the glass substrate (inspection substrate) on which the conductive pattern to be inspected is formed is conveyed to a predetermined position of the substrate inspection apparatus along a conveyance path (not shown). In step S 2, the inspection substrate is held and positioned by the substrate mounting stage 14 described above.

This board-mounted stage 14 is configured so that three-dimensional position control is possible by four-axis control of XYZ 0 angle. . For example, the open sensor 13 is positioned so as to be near the right end of the conductive pattern 2a which is the innermost side of the conductive pattern shown in FIG.

After positioning the inspection board to the measurement position in this way, in step S 3, for example, the signal generation unit 10 is controlled by the control unit 15, and the above-described high-frequency signal (inspection signal) of 200 kHz ) Is supplied to the power feeding section 1 2. In step S5, the signal processing unit 21 performs the above-described waveform processing, signal conversion processing, and the like. In subsequent step S6, the control unit 15 stores these processing results in the memory (R A M I 7).

In step S7, it is determined whether processing and inspection have been completed for all conductive patterns to be inspected. This determination is made, for example, based on whether or not the movement distance of the inspection substrate matches the distance obtained by adding up the total of all the conductive pattern widths and the total of the pattern intervals. Therefore, if the result of determination in step S7 is that processing / inspection of all conductive patterns has not been completed, the control unit 15 determines that the next conductive pattern to be inspected is the open sensor 1 3 in step S8. The drive unit 16 is controlled to move the inspection board by a predetermined distance so that it is positioned directly below (specifically, The open sensor 13 is controlled so as to move relatively in the direction of the arrow in FIG. 2 by the distance between the centers of adjacent row-shaped conductive patterns).

After that, the control unit 15 returns the process to step S5 and performs the same process as described above. As a result, the above-described waveform processing and the like are continuously executed for the conductive pattern to be inspected, and the processing results corresponding to each pattern are sequentially stored in R A M I 7.

In this way, in the inspection procedure in FIG. 5, the procedure from step S5 to step S8 is performed while the inspection substrate is moved while maintaining the state where the inspection signal is supplied to the power feeding unit (the state of step S3). That is, the unit 5 sequentially scans the conductive pattern to be inspected. This movement of the inspection board is stopped while the inspection board is moved by a predetermined distance (Step S 8) and the sensor output signal processing (Step S 5) and the processing result are stored (Step S 6). The sensor output signal is processed (Step S 5) and the processing result is stored (Step S 6) while the inspection board is moved a predetermined distance (Step S 8). You may move. In particular, in order to shorten the inspection time, the procedure from step S5 to step S8 is effective if the inspection board is moved continuously without stopping.

On the other hand, when all the conductive patterns to be inspected have been inspected, that is, when the movement distance of the inspection board matches the sum of the total conductive pattern width and the total pattern interval (Step S In step S9), the processing result stored in RAM 17 is analyzed in step S9, and the quality of the inspection object is determined based on the analysis result. Specifically, the result obtained by processing the sensor output signal is compared with a reference value, and if it is greater than or equal to the reference value, it is determined that the conductive pattern is not open.

In step S10, if it is determined that the detection signal levels at the respective conductive pattern positions are all within the predetermined range, it is determined that all the conductive patterns are normal. In step S 12, the control unit 15 controls the display unit 25 to display that the inspection object is a non-defective product.

In this way, when the inspection target is a non-defective product, the inspection board is lowered to the transfer position, placed on the transfer path, and transferred to the next stage. When performing continuous inspection, the process returns to step S1, and the substrate to be inspected next is transported to a predetermined position of the substrate inspection apparatus.

However, if the detection signal level at the position of the conductive pattern is not within the predetermined range even at one location, it is determined that the conductive pattern is defective, and the control unit 15 checks the display unit 25 in step S 1 3. Control to display that the target is defective. Then, the inspection substrate is lowered to the transfer position and placed on the transfer path and transferred to the next stage, or the defective substrate is removed from the transfer path.

The arrangement of the conductive pattern to be inspected on the board is shown on the board.

The present invention is not limited to the example in which only the pattern shown in 1 is provided, and the inspection method of the present invention can be applied to a case where a plurality of sets of inspection patterns are arranged on the same substrate.

In the above-described embodiment, the presence or absence of the open state of the conductive pattern to be inspected is determined based on the detection signals from the open sensor 1 3 and the noise sensor 1 9. It is also possible to detect a short circuit between each other.

For example, in the board inspection apparatus shown in FIG. 1, the above-mentioned pattern is adjacent to the conductive pattern in which the power feeding section 12 is disposed, and the end portion on the opposite side of the power feeding section 12 is disposed in a non-contact manner. Open sensor 1 A short sensor having the same function as 3 is arranged. Even in this case, since the short sensor is capacitively coupled to the conductive pattern to be inspected, if the adjacent conductive patterns are short-circuited, the inspection from the power feeding section 12 A signal is applied to the pattern in a short circuit condition.

For this reason, the inspection signal flowing through the short-circuit point is detected by the short sensor as the strength of the detection signal level. That is, the short sensor detects the short-circuit current as a higher level inspection signal. The signal detected by the short sensor and the signal detected by the noise sensor 19 are input to the positive input terminal (+) and negative input terminal (one) of the differential amplifier (op amp), respectively, and are amplified. As a result, when there is a short circuit between adjacent conductive patterns, a difference occurs in the intensity of the detection signal compared to the normal state. As described above, the noise signal is applied to all conductive patterns.

Since the signal is in-phase with respect to the positive and negative input terminals of the differential amplifier, the differential amplifier takes the difference between these signals and removes noise from the detection signal of the short sensor. Note that the short sensor may detect a signal from, for example, at least two column-shaped conductive patterns adjacent to the column-shaped conductive pattern to be inspected.

Similarly to the open sensor in the above embodiment, the short sensor is moved in the direction of the arrow shown in FIG. It is possible to extract changes in detection results.

As described above, when inspecting the quality of conductive patterns arranged in a row on a substrate in a non-contact manner, a power feeding unit that supplies an inspection signal to one end of the conductive pattern is arranged, and the conductive pattern An open sensor for detecting the inspection signal is placed at the other end, and a noise sensor is placed at the end on the same side as the open sensor is placed in a conductive pattern several distances away from the conductive pattern. The signal that mixed the inspection signal and noise detected by the open sensor from the inspection target pattern and the noise sensor A noise-only signal detected from the conductive pattern and not mixed with the inspection signal is input to the differential amplifier.

In this case, since these noise signals are in-phase component signals with respect to the positive and negative input terminals of the differential amplifier, only the noise signal is easily removed from the detection signal by taking the difference with the differential amplifier. It is possible to eliminate the influence of noise and improve the detection accuracy of the open state of the conductive pattern.

In addition, since the response speed is significantly faster than when noise is removed by adding a filter, multiple patterns to be inspected can be scanned at high speed, resulting in a significant reduction in inspection speed and inspection time. The defective part of the conductive pattern can be reliably detected. Industrial applicability

According to the present invention, it is possible to accurately and reliably detect the quality of a conductive pattern on a substrate to be inspected.

In addition, according to the present invention, the inspection speed of the conductive pattern can be increased.

Claims

The scope of the claims

1. A circuit pattern inspection apparatus for inspecting the state of a conductive pattern arranged on a substrate,

A signal supply means for supplying an inspection signal to the first portion of the conductive pattern to be inspected;

A first detection means capable of detecting a first signal from a second part of the conductive pattern to be inspected;

Second detection means capable of detecting a second signal from a conductive pattern separated from the conductive pattern to be inspected by at least 4 to 5 patterns; a difference between the first signal and the second signal Difference means for obtaining

A circuit pattern inspection apparatus comprising: an identification unit that identifies the quality of the conductive pattern based on a change in the difference signal obtained by the difference unit.

2. A circuit pattern inspection device for inspecting the state of a conductive pattern arranged on a substrate,

A second detection means capable of detecting a second signal from a conductive pattern spaced a predetermined distance from the conductive pattern to be inspected;

Difference means for obtaining a difference between the first signal and the second signal;

A circuit pattern inspection apparatus comprising: identification means for identifying the quality of the conductive pattern based on a change in the difference signal obtained by the difference means.

3. The difference unit according to claim 1 or 2, wherein the difference means removes the second signal that is the noise signal from the first signal in which the noise signal is superimposed on the inspection signal. The circuit pattern inspection apparatus described.

4. The circuit pattern inspection apparatus according to claim 3, wherein the identification unit identifies a disconnection state of the conductive pattern based on the signal from which the noise signal has been removed.

5. The apparatus further comprises means for positioning and moving the signal supply means, the first detection means, and the second detection means so as to sequentially scan the conductive pattern to be inspected. The circuit pattern inspection apparatus according to claim 1 or 2.

6. By the scanning, the inspection signal is supplied to the conductive pattern and the inspection signal is detected from the conductive pattern in the vicinity of the tips of all patterns at one end of the conductive pattern. The circuit pattern inspection device according to claim 5.

7. The signal supply means includes a plate member opposed to the conductive pattern at a predetermined interval, and supplies the inspection signal in a non-contact manner through capacitive coupling between the plate member and the conductive pattern. The circuit pattern inspection apparatus according to claim 6.

8. Each of the first detection means and the second detection means includes a plate member that is opposed to the conductive pattern at a constant interval, and is not connected via capacitive coupling between the plate member and the conductive pattern. 7. The circuit pattern inspection apparatus according to claim 6, wherein the signal is detected by contact.

9. A circuit pattern inspection method in a circuit pattern inspection apparatus for inspecting the state of a conductive pattern arranged on a substrate,

Supplying an inspection signal to the first portion of the conductive pattern to be inspected; A first detection step of detecting a first signal from a second portion of the conductive pattern to be inspected;

A second detection step of detecting a second signal from a conductive pattern at least 4 to 5 away from the conductive pattern to be inspected;

A difference calculating step for obtaining a difference between the first signal and the second signal, and an identification step for identifying the quality of the conductive pattern based on a change in the difference signal obtained in the difference calculating step. Circuit pattern inspection method.

1 0. A circuit pattern inspection method in a circuit pattern inspection apparatus for inspecting the state of a conductive pattern arranged on a substrate, comprising:

Supplying an inspection signal to the first portion of the conductive pattern to be inspected;

A first detection step of detecting a first signal from a second portion of the conductive pattern to be inspected;

A second detection step of detecting a second signal from a conductive pattern spaced a predetermined distance from the conductive pattern to be inspected;

A difference calculating step for obtaining a difference between the first signal and the second signal; and an identification step for identifying the quality of the conductive pattern based on a change in the difference signal obtained in the difference calculating step. Circuit pattern inspection method.

11. The difference calculation step, wherein the second signal that is the noise signal is removed from the first signal in which a noise signal is superimposed on the inspection signal. 10. Circuit pattern inspection method described in 10.

1 2. The identification step may identify a disconnection state of the conductive pattern based on a signal from which the noise signal has been removed. The circuit pattern inspection method described.

Further comprising the step of positioning and moving the signal supply means, the first detection means, and the second detection means so as to sequentially scan the conductive pattern to be inspected. Item 9. The circuit pattern inspection method according to Item 10 or Item 10.

14. Supplying the inspection signal to the conductive pattern and detecting the inspection signal from the conductive pattern for the vicinity of the tips of all patterns at one end of the conductive pattern by the scanning. The circuit pattern inspection method according to claim 13.

15. The signal supply unit includes a plate member facing the conductive pattern at a predetermined interval, and supplies the inspection signal in a non-contact manner through a capacitive coupling between the plate member and the conductive pattern. The circuit pattern inspection method according to claim 14.

16. Each of the first detection means and the second detection means includes a plate member facing the conductive pattern at a constant interval, and is in non-contact via capacitive coupling between the plate member and the conductive pattern. The circuit pattern inspection method according to claim 14, wherein a signal is detected by the method.

17. A computer-readable recording medium that stores a computer program for realizing the circuit pattern inspection method according to any one of claims 9 to 16 by computer control.

1 8. A computer program sequence for realizing the circuit pattern inspection method according to any one of claims 9 to 16 by computer control.