JP5893436B2 - Tip position specifying method and tip position specifying device for specifying the tip position of a line area displayed as an image, and position specifying method and position specifying device for specifying the position of a short-circuit defect - Google Patents

Description

  The present invention relates to a tip position specifying method and tip position specifying device that specify the tip position of an image-displayed line region, and a position specifying method and position specifying device that specify the position of a short-circuit defect.

  As an image processing apparatus, a method for detecting a tip position of a long side of a rectangular area in order to obtain a width (line width) of the rectangular area, that is, a short side of the rectangular area, by defining the line area as an elongated rectangular area There is.

Patent Document 1 discloses a method for extracting a rectangular edge by differentiation and applying a Hough transform to obtain a long and narrow rectangular area in order to obtain a narrow parallel line pair (a pair of long sides of a rectangular area). Has been. The Hough transform includes an image scanning unit and a storage unit called a voting box. A straight line with a certain slope through a point in the image is associated with one of the ballot boxes. However, straight lines passing through different points are linked to the same ballot box if the slope and intercept are equal. First, assume that the image scanning unit sequentially scans the entire input image, and a pixel at a certain coordinate (i, j) has a value I _ij . At that time, the image scanning unit increments the value of the ballot box associated with all straight lines passing through the coordinates (i, j) by I _ij . When scanning of the entire image is completed, the values of all ballot boxes are examined, and a straight line corresponding to a ballot box having a value larger than a predetermined value is selected as a straight line to be detected. Finally, a logical product is obtained for each pixel of the straight line and the original image, and a line segment is extracted from the image.

  Patent Document 2 also discloses a method for performing line segment extraction processing using Hough transform.

JP 62-84391 (published April 17, 1987) Japanese Patent Laid-Open No. 9-97331 (published on April 8, 1997)

  By the way, a so-called thermo inspection device is known in which a current is passed through a wiring formed on a panel and the panel is photographed with an infrared camera to inspect for the presence of a short-circuit defect in the wiring. When obtaining a heat generating part (part containing a short-circuit defect), if the heat generation is low, the heat generating part will not have a well-formed rectangle, the outer shape may be uneven, the heating line width may change, Is divided. Therefore, even if the Hough transform is performed on the pixel group extracted by edge extraction using the method of Patent Document 1 in the thermo inspection apparatus, it is difficult to obtain the parallel line pair. In addition, when an image having a lot of noise is used, direction detection may be erroneously performed. As a result, the shorter side (straight line end) of the correct rectangle may not be obtained. This means that the wiring including the short-circuit defect cannot be specified accurately, and further, when the short-circuit defect is repaired, the repair process is hindered.

  The present invention has been made in view of the above-mentioned problems, and the object thereof can be applied to a thermo inspection apparatus without any problem, and the tip position of a straight line (line region) can be specified with high accuracy. Another object of the present invention is to provide a tip position specifying method and tip position specifying device for specifying a tip position of an image-displayed line region, and a position specifying method and a position specifying device for specifying the position of a short-circuit defect.

Therefore, in order to solve the above problem, the tip position specifying method for specifying the tip position of the image-displayed line region according to the present invention is:
The line area displayed as an image is defined as a rectangular area, a first projection profile is created along the long side of the rectangular area for the image of the inspection area including the rectangular area, and the peak position of the first projection profile A second projection profile is created along the short side of the rectangular area displayed in the image for a local area of a plurality of pixels centered on, and the profile value less than a predetermined threshold is obtained by scanning the second projection profile. It is characterized in that it includes a specifying step of specifying, as the tip position, the position of a pixel that first shows a profile value less than the predetermined threshold when it is determined that a certain number of pixels are continuous.

  According to the above configuration, the image is projected in the direction orthogonal to the longitudinal direction of the line area, that is, in the short side direction of the rectangular area, and the position of the pixel continuously below the predetermined threshold in the projection result is determined. This is identified and used as the tip position of the line area.

  As a result, the conventional method of identifying the tip position of a line region using the Hough transform for detecting line segments in any direction may cause many false detections when applied to the entire image with a lot of background noise. By adopting the configuration of the present invention, it is possible to specify the tip position of the line segment after selecting the region including the line segment from the entire image, and thus it is possible to specify the tip position with high accuracy.

  Therefore, when obtaining the heat generation part (part containing a short-circuit defect) of the wiring using the thermo inspection device, it is converted into one-dimensional data by projecting an image in the short side direction by adopting the above configuration. In the case of low heat generation, the heat generation portion does not become a well-formed rectangle, and even if the outer shape is uneven or the heat generation line width is changed, according to the above configuration, the length of the line region By projecting an image in the direction orthogonal to the direction, that is, in the short side direction of the rectangular area, the position of the short-circuit defect (the tip of the line area) can be accurately detected.

In addition to the above configuration, one form of the method for specifying the tip position of the image-displayed line region according to the present invention is as follows.
The images used for the first projection profile and the second projection profile may be binarized images.

  According to said structure, even if it uses the binarized image, a front-end | tip position can be pinpointed accurately.

Moreover, in order to solve the above-mentioned problem, according to the present invention, the short-circuit defect location method is:
A position specifying method for specifying a position of a short-circuit defect in a wiring formed on a substrate,
A voltage applying step of applying a predetermined voltage to the wiring;
A measuring step of continuously measuring a temperature of at least a part of the region of the semiconductor substrate to which a voltage is applied in the voltage applying step using an infrared camera;
A determination step of determining whether a temperature rise value derived by subtracting the temperature value of the semiconductor substrate before applying the voltage from the temperature value measured in the measurement step is equal to or greater than a threshold value;
The display image of the line area corresponding to the wiring including the pixel for which the temperature rise value is determined to be equal to or greater than the threshold and the pixel for which the temperature increase value is less than the threshold in the determination step is defined as a rectangular area, and the image of the inspection area including the rectangular area In contrast, a first projection profile parallel to the long side of the rectangular region is created, and a plurality of pixel local regions centered on the peak position of the first projection profile are parallel to the short side of the rectangular region. A second projection profile is created, and when the second projection profile is scanned and a profile value less than a predetermined threshold value is determined to be continuous for a certain number of pixels, the predetermined threshold value is the first of the consecutive pixels. And a specific step of setting a position of a pixel that shows a profile value less than the position of the short-circuit defect.

  According to said structure, the area | region containing a line segment is selected from the whole image, and an image is projected to a short side direction with respect to the area | region containing the selected line segment. This projection process can convert two-dimensional data into one dimension. That is, the projection profile created by projecting the image in the short side direction is one-dimensional data of only the line segment and only the background in the short side direction, and therefore, only the line segment and only the background are cut by scanning. That is, the tip position (defect position) of the line segment can be specified with high accuracy. Therefore, since the defect has low heat generation, the temperature change is insufficient, and it is difficult to specify whether or not it is a defect by the defect detection method using the difference image of the infrared image. However, the defect position can be identified with high accuracy by using numerical data such as a projection profile value without using a method that relies on visual observation.

In addition, in order to solve the above-described problem, the tip position specifying device for specifying the tip position of the line area displayed as an image according to the present invention is:
The line area displayed as an image is defined as a rectangular area, a first projection profile is created along the long side of the rectangular area for the image of the inspection area including the rectangular area, and the peak position of the first projection profile A second projection profile is created along the short side of the rectangular area displayed in the image for a local area of a plurality of pixels centered on, and the profile value less than a predetermined threshold is obtained by scanning the second projection profile. When it is determined that a certain number of pixels are continuous, it is characterized by comprising a specifying means for specifying, as the tip position, the position of a pixel that first shows a profile value less than the predetermined threshold value.

  According to the above configuration, the image is projected in the direction orthogonal to the longitudinal direction of the line area, that is, in the short side direction of the rectangular area, and the position of the pixel continuously below the predetermined threshold in the projection result is determined. This is identified and used as the tip position of the line area.

  As a result, the tip position can be specified with higher accuracy than the conventional method of specifying the tip position of the line region using the Hough transform.

In addition, in order to solve the above-described problem, the short-circuit defect location device according to the present invention is:
A position specifying device for specifying a position of a short-circuit defect of wiring formed on a substrate,
Voltage applying means for applying a predetermined voltage to the wiring;
An infrared camera for photographing the above wiring;
Measuring means for measuring the temperature of at least a part of the substrate including the wiring using the infrared camera;
It is determined whether or not a temperature rise value derived by subtracting the temperature value of the semiconductor substrate before applying the voltage from the temperature value measured by the measuring means is equal to or greater than a threshold value. The display image of the line area corresponding to the wiring including the pixels determined to be above and the threshold value is defined as a rectangular area, and the length of the rectangular area with respect to the image of the inspection area including the rectangular area Creating a first projection profile parallel to the side, creating a second projection profile parallel to the short side of the rectangular region for a local region of a plurality of pixels centered on the peak position of the first projection profile; When the second projection profile is scanned and it is determined that the profile value less than the predetermined threshold is continuous for a certain number of pixels, the image that first shows the profile value less than the predetermined threshold among the continuous pixels. The position is characterized by comprising, specifying means for the position of the short-circuit defect.

  According to the above configuration, since the defect has low heat generation, the temperature change is insufficient, and it is difficult to specify whether the defect is a defect in the defect detection method using the difference image of the infrared image. Even in this case, the defect position can be specified with high accuracy by using numerical data such as a projection profile value without using a method that relies on visual observation.

  According to the present invention, it is possible to provide a method for specifying the tip position of an image-displayed line region and a method for specifying a position of a short circuit defect, which can specify the position with high accuracy.

1 is a block diagram illustrating a configuration of a wiring defect detection device according to an embodiment of the present invention, and a perspective view illustrating a configuration of a mother substrate having a liquid crystal panel. It is a perspective view which shows the structure of the wiring defect detection apparatus which concerns on embodiment of this invention. It is a top view of the liquid crystal panel and probe which concern on embodiment of this invention. It is a flowchart which shows the wiring defect detection method which concerns on embodiment of this invention. It is a schematic diagram which shows the defect of the pixel part which concerns on embodiment of this invention. It is a figure which shows the image imaged with the wiring defect detection method which concerns on embodiment of this invention, and its binarized image. It is a figure which shows the 1st projection profile and the 2nd projection profile which are produced with the wiring defect detection method concerning the embodiment of the present invention. It is a schematic diagram which shows the short circuit path | route used in embodiment of this invention.

  FIG. 1 to FIG. 8 show an embodiment of a method for specifying the position of the tip of a line region according to the present invention and a method for specifying a position of a short circuit defect in a liquid crystal panel, which is an embodiment of a method of specifying a position of a short circuit defect. The description will be given with reference.

  In the following, the configuration of a wiring defect detection device that realizes a method for specifying the position of a short circuit defect in a wiring will be described, and then the method for specifying the position of a short circuit defect will be described.

(1) Configuration of Wiring Defect Detection Device FIG. 1A is a block diagram showing a configuration of a wiring defect detection device 100 that realizes a method for specifying a position of a short circuit defect in wiring according to the present embodiment. FIG. 7B is a perspective view of the mother substrate 1 (semiconductor substrate) that is a target for which a wiring defect is detected using the wiring defect detection apparatus 100.

  The wiring defect detection apparatus 100 can detect defects such as wiring in a plurality of liquid crystal panels 2 (semiconductor substrates) formed on the mother substrate 1 shown in FIG. Therefore, as shown in FIG. 1A, the wiring defect detection apparatus 100 includes a probe 3 for conducting electrical connection with the liquid crystal panel 2, a probe moving unit 4 for moving the probe 3 onto each liquid crystal panel 2, and an infrared image. An infrared camera 5 for acquisition, a camera moving unit 6 for moving the infrared camera 5 on the liquid crystal panel 2, and a control unit 7 for controlling the probe moving unit 4 and the camera moving unit 6 are provided.

  The probe 3 is connected to a resistance measuring unit 8 for measuring the resistance between the wirings of the liquid crystal panel 2 and a voltage applying unit 9 for applying a voltage between the wirings of the liquid crystal panel 2. The resistance measuring unit 8 and the voltage applying unit 9 are controlled by the control unit 7.

  The control unit 7 is connected to a data storage unit 10 that stores resistance values between wirings and image data.

  FIG. 2 is a perspective view of the wiring defect detection apparatus 100. As shown in FIG. 2, the wiring defect detection apparatus 100 is configured such that an alignment stage 11 is installed on a base, and the mother substrate 1 can be placed on the alignment stage 11. The alignment stage 11 on which the mother substrate 1 is placed is adjusted in parallel with the XY coordinate axes of the probe moving unit 4 and the camera moving unit 6. At this time, for the position adjustment of the alignment stage 11, an optical camera 12 provided above the alignment stage 11 for confirming the position of the mother substrate 1 is used.

  The probe moving means 4 is slidably installed on a guide rail 13 a disposed outside the alignment stage 11. Guide rails 13b and 13c are also installed on the main body side of the probe moving means 4, and the mount portion 14a is installed so as to be able to move in the XYZ coordinate directions along these guide rails 13. A probe 3 corresponding to the liquid crystal panel 2 is mounted on the mount portion 14a.

  The camera moving means 6 is slidably installed on a guide rail 13d disposed outside the probe moving means 4. Further, guide rails 13e and 13f are also installed on the main body of the camera moving means 6, and the three mount portions 14b, 14c, and 14d are separately moved along the guide rails 13 in the XYZ coordinate directions. can do.

  In the present embodiment, there are two types of infrared cameras 5 provided in the wiring defect detection device 100. One is an infrared camera 5a for macro measurement, and the other is an infrared camera 5b for micro measurement. The infrared camera 5a for macro measurement is mounted on the mount 14c, the infrared camera 5b for micro measurement is mounted on the mount 14b, and the optical camera 16 is mounted on the mount 14d.

  The infrared camera 5a for macro measurement is an infrared camera capable of macro measurement with a field of view extended to about 520 × 405 mm. The infrared camera 5a for macro measurement is configured by combining, for example, four infrared cameras in order to widen the field of view. That is, the field of view per macro measurement infrared camera is approximately ¼ that of the mother board 1. The infrared camera 5b for micro measurement is an infrared camera capable of micro measurement capable of high-resolution imaging although the field of view is as small as about 32 × 24 mm.

  The camera moving means 6 may be equipped with a laser irradiation device for correcting a defective portion by adding a mount portion. By mounting the laser irradiation device, the defect can be continuously corrected by irradiating the defect with a laser after specifying the position of the defect.

  The probe moving means 4 and the camera moving means 6 are installed on separate guide rails 13a and 13d, respectively. Therefore, it is possible to move above the alignment stage 11 in the X coordinate direction without interfering with each other. As a result, the infrared cameras 5 a and 5 b and the optical camera 16 can be moved onto the liquid crystal panel 2 while the probe 3 is in contact with the liquid crystal panel 2.

  FIG. 3A is a plan view of one liquid crystal panel 2 among the plurality of liquid crystal panels 2 formed on the mother substrate 1. As shown in FIG. 3A, each liquid crystal panel 2 includes a pixel portion 17 in which a TFT is formed at each intersection where the scanning line and the signal line intersect, and a driving circuit that drives the scanning line and the signal line, respectively. A portion 18 is formed. Terminal portions 19 a to 19 d are installed at the edge of the liquid crystal panel 2, and the terminal portions 19 a to 19 d are connected to the wiring of the pixel portion 17 or the drive circuit portion 18.

  FIG. 3B is a plan view of the probe 3 (voltage applying means) for conducting with the terminal portions 19 a to 19 d installed on the liquid crystal panel 2. The probe 3 has a frame-like shape that is almost the same size as the liquid crystal panel 2 shown in FIG. 3A, and a plurality of probes corresponding to the terminal portions 19 a to 19 d installed on the liquid crystal panel 2. Needles 21a to 21d are provided.

  The probe needles 21a to 21d are individually connected to the resistance measuring unit 8 and the voltage applying unit 9 shown in FIG. 1A through switching relays (not shown). Can do. For this reason, the probe 3 can selectively connect a plurality of wires connected to the terminal portions 19a to 19d, or can connect the plurality of wires together.

  The probe 3 has a frame shape that is substantially the same size as the liquid crystal panel 2. Therefore, when the positions of the terminal portions 19 a to 19 d and the probe needles 21 a to 21 d are aligned, the positions can be confirmed using the optical camera 16 from the inside of the frame of the probe 3.

  As described above, the wiring defect detection apparatus 100 includes the probe 3 and the resistance measuring unit 8 connected to the probe 3, and connects the probe 3 to the liquid crystal panel 2 to connect each wiring as described later. The resistance value and the resistance value between adjacent wirings can be measured.

  Then, the temperature of the liquid crystal panel 2 is measured using the infrared camera 5 before and after applying a predetermined voltage between the wirings of the liquid crystal panel 2 or between the wirings via the probe 3. Specifically, the liquid crystal panel 2 is imaged with a moving image using the infrared camera 5 before and after applying the voltage. A moving image obtained by imaging is stored in the data storage unit 10.

  The moving image stored in the data storage unit 10 is subjected to data processing in the control unit 7, and a temperature value for each pixel is calculated. This temperature value is also stored in the data storage unit 10.

  Further, the control unit 7 calculates a difference image from the image before voltage application and the image after voltage application stored in the data storage unit 10, and based on the heat generated by voltage application for each pixel of the imaged data. Calculate the temperature rise value. Thus, this “pixel of imaged data” is expressed as “data pixel”. In the present embodiment, when the calculated temperature rise value exceeds a preset temperature rise threshold within a preset time (number of frames) threshold, the corresponding data pixel is connected to the wiring connected to the defective portion. Judge that it corresponds. Therefore, a linear image corresponding to the wiring is specified from the data pixels exceeding the temperature rise threshold, and the tip position of the linear image is specified. This tip position is a defective part.

(2) Wiring Defect Detection Method Defect detection performed using the wiring defect detection apparatus 100 will be described in detail below. The wiring defect detection method of this embodiment is
(I) a voltage applying step of applying a predetermined voltage to the wiring formed on the liquid crystal panel 2;
(Ii) a measurement step of continuously measuring the temperature of at least a part of the liquid crystal panel 2 to which a voltage is applied in the voltage application step using the infrared camera 5 for a certain period of time;
(Iii) a determination step of determining whether or not a temperature rise value derived by subtracting the temperature value of the liquid crystal panel 2 before voltage application from the temperature value measured in the measurement step is equal to or greater than a threshold value;
(Iv) A display image of a line area corresponding to the wiring is defined as a rectangular area with respect to an image including a pixel in which the temperature increase value is determined to be equal to or higher than the threshold value and a pixel determined to be lower than the threshold value in the determination step. A first projection profile along the long side of the rectangular area is created for the image of the inspection area including the rectangular area, and a plurality of local areas centered on the peak position of the first projection profile are created. First, when a second projection profile is created along the short side of the rectangular area where the image is displayed, and the second projection profile is scanned and it is determined that profile values less than a predetermined threshold are continuous for a certain number of pixels A specifying step of specifying, as the tip position, the position of a pixel that indicates a profile value less than the predetermined threshold value;
including.

  FIG. 4 is a flowchart of a wiring defect detection method using the wiring defect detection apparatus 100 according to the present embodiment.

  In the wiring defect detection method of the present embodiment, wiring defect detection is sequentially performed on the plurality of liquid crystal panels 2 formed on the mother substrate 1 shown in FIG. .

  In step S1, the mother substrate 1 is placed on the alignment stage 11 of the wiring defect detection apparatus 100 shown in FIG. 2, and the position of the substrate is adjusted so as to be parallel to the XY coordinate axes.

  In step S2, the probe 3 is moved by the probe moving means 4 shown in FIG. 2 to the upper part of the liquid crystal panel 2 to be detected on the mother substrate 1 whose position has been adjusted in step S1, and the probe needles 21a to 21d are moved to the liquid crystal. It contacts the terminal portions 19a to 19d of the panel 2.

  In step S3, following step S2, corresponding to various defect detection modes, wiring for resistance inspection or between wirings is selected, and the probe needle 21 to be conducted is switched.

  Here, various defect detection modes will be described with reference to FIGS. 5A to 5C schematically show the positions of the defect portions 23 (short-circuit defects) generated in the pixel portion 17 as an example.

  FIG. 5A shows, for example, in a liquid crystal panel in which the wiring X and the wiring Y intersect vertically like the scanning line and the signal line, the defective portion 23 in which the wiring X and the wiring Y are short-circuited at the intersection. Is shown. The probe needle 21 to be conducted is switched to the pair of 21a and 21d or the pair of 21b and 21c shown in FIG. 3, and the resistance value between the wirings is measured 1: 1 with respect to the wirings X1 to X10 and the wirings Y1 to Y10. Thus, the presence or absence of the defective portion 23 can be specified.

  FIG. 5B shows a defective portion 23 that is short-circuited between adjacent wiring lines X such as a scanning line and an auxiliary capacitance line. Such a defective portion 23 is obtained by switching the probe needle 21 to be conducted to a pair of the odd number 21b and the even number 21d and measuring the resistance value between the adjacent wires X1 to X10. The wiring with the part 23 can be specified.

  FIG. 5C shows a defective portion 23 that is short-circuited between adjacent wirings Y such as a signal line and an auxiliary capacitance line. Such a defective portion 23 is obtained by switching the probe needle 21 to be electrically connected to a pair of the odd number 21a and the even number 21c and measuring the resistance value between the adjacent wires Y1 to Y10. The wiring with the portion 23 can be specified.

  In step S4, the probe needle 21 switched in step S3 is conducted, and the resistance value between the selected wirings or wirings is measured and acquired. The acquired resistance value is stored in the data storage unit 10.

  In step S5, the resistance value acquired in step S4 is compared with the wiring of the panel (reference panel) having no defect or the resistance value between the wirings stored in advance in the data storage unit 10. Here, when the resistance value acquired in step S4 is the same as the resistance value between the wirings of the panel having no defect stored in advance in the data storage unit 10 or between the wirings, the process proceeds to step S23. When the resistance value acquired in step S4 is the same as the resistance value between the wiring of the panel having no defect or between the wirings, it can be specified that there is no defect in this detection mode. On the other hand, in step S5, when the resistance value acquired in step S4 is not the same as the resistance value between the wirings of the panel having no defect and stored in advance in the data storage unit 10, the process proceeds to step S6. If the resistance value acquired in step S4 is not the same as the resistance value between the wirings of the panel having no defects and stored in advance in the data storage unit 10, there is a defect between the wirings or the wirings in this detection mode. It can be identified that there is a possibility. If there is a possibility that a defect exists, it is necessary to perform infrared detection.

  For example, as shown in FIG. 5A, when a defect 23 occurs at a location where the wiring X and the wiring Y intersect, an abnormality is detected in the wiring X4 and the wiring Y4 by the resistance inspection between the wirings. The position up to the defect portion 23 can be specified. Therefore, in the case of the defect portion 23 shown in FIG. 5A, it is not always necessary to specify the position by infrared detection. That is, if a resistance inspection is performed for every combination of the wiring X and the wiring Y, the position can be specified, so that infrared detection is not necessary. However, since the number of combinations is enormous, it takes a long time. For example, in the case of a full high-definition liquid crystal panel, since there are 1080 lines X and lines Y 1920, the total number of combinations is about 2.70 million. If a resistance test is performed for each such combination, the tact time becomes long and the detection processing capability is greatly reduced, which is not realistic. Therefore, the number of resistance inspections can be reduced by combining all the combinations of the wiring X and the wiring Y into several and performing a resistance inspection. For example, if a resistance test is performed between the wiring X grouped together and the wiring Y grouped together, the number of times of resistance testing is only one. However, a short circuit between wirings can be detected by resistance inspection, but the position cannot be specified. Therefore, it is necessary to specify the position of the defect portion 23 by infrared detection.

  On the other hand, as shown in FIG. 5 (b) or FIG. 5 (c), when a defective portion 23 occurs between adjacent wirings, there is a defective portion between a pair of wirings, for example, the wiring X3 and the wiring X4. Can be identified. However, since the position of the defect portion 23 cannot be specified in the length direction of the wiring, it is necessary to specify the position of the defect portion 23 by infrared detection.

  Since the resistance inspection between adjacent wirings is enormous, it takes a long time. For example, in the case of a full high-definition liquid crystal panel, the number of resistance inspections between adjacent wires X is 1079, and the number of resistance inspections between adjacent wires Y is 1919. In the case of resistance inspection between adjacent wirings X as in the case of FIG. 5B, if resistance inspection is performed between all X odd numbers and all X even numbers, the number of resistance inspections is only one. Times. In the case of resistance inspection between adjacent wirings Y as in FIG. 5C, if resistance inspection is performed between all Y odd numbers and all Y even numbers, the number of resistance inspections is only one. Times. However, a short circuit between wirings can be detected by resistance inspection, but the position cannot be specified. Therefore, it is necessary to specify the position of the defect portion 23 by infrared detection.

  Therefore, in step S6 (voltage application step), the voltage value applied to the wiring by infrared detection for the liquid crystal panel 2 is set based on the resistance value stored in the data storage unit 10 in step S4. Specifically, in step S6, an applied voltage V (volt) proportional to the square root of the resistance value acquired in step S4 is applied to the liquid crystal panel 2. That is, in step S6, the applied voltage V (volt) is changed to the following formula (1);

And set.

  Here, the calorific value J (joule) per unit time is expressed by the following formula (2):

From the above formulas (1) and (2), the calorific value J per unit time is represented by the following formula (3);

It is expressed.

  That is, by applying an applied voltage V (volt) proportional to the square root of the resistance value to the liquid crystal panel 2 based on the formula (1), the heat generation amount per unit time can be made constant.

  Therefore, the resistance value of the short-circuit path including the defect 23 varies greatly depending on the type of substrate or the cause of the short-circuit on the substrate, such as the occurrence location of the defect 23. However, if step S6 of this embodiment is performed, per unit time The calorific value of can be made constant.

  In the present embodiment, the resistance test and the voltage value setting based on the resistance value obtained by the resistance test are performed. However, the present invention is not limited to this, and the resistance test is not performed. The predetermined voltage value may be applied to the liquid crystal panel in the following steps. However, if the wiring board to be inspected is a comparatively large one as in this embodiment, a wiring board without a short-circuit defect is obtained by conducting a resistance inspection and inspecting in advance for the presence or absence of a short-circuit defect. In addition, it is possible to omit the infrared detection between the wirings and between the wirings, which can contribute to shortening the inspection work time.

  In step S7, before applying a voltage based on the voltage value set in step S6 to the liquid crystal panel 2, a moving image of the liquid crystal panel 2 that does not generate heat is read using the infrared camera 5. More specifically, the control unit 7 shown in FIG. 1 measures the temperature of the liquid crystal panel 2 that does not generate heat by using the infrared camera 5, and stores the measured temperature value data in the computer. The data is read into the memory and stored in the data storage unit 10.

  In step S8 (voltage application step, measurement step), first, a voltage based on the voltage value set in step S6 is applied to the liquid crystal panel 2. Then, the infrared camera 5 is used to read a moving image of the liquid crystal panel 2 that has generated heat after the voltage is applied. More specifically, the control unit 7 shown in FIG. 1 measures the temperature value of the liquid crystal panel 2 that is generating heat using the infrared camera 5, and stores the measured temperature value data as image data. The data is read into the computer memory and stored in the data storage unit 10. Here, the adjustment of the applied voltage is performed by the control unit 7 controlling the voltage application unit 9.

  In step S9 (determination step), the control unit 7 calculates a temperature increase threshold value from the moving image before voltage application read in step S7. Here, a method for calculating the temperature increase threshold in the present embodiment will be described with reference to FIG.

  As shown in FIG. 6, the temperature rise threshold value is obtained by integrating the moving images between adjacent frames of the moving image (9 frames) of the liquid crystal panel 2 that is not generating heat before voltage application. To create a background image (signed (not absolute value)), and using the average value and standard deviation of the histogram of this background image, the following equation (4);

Is set.

  For example, if n is set large, the temperature rise threshold value is increased from the equation (4), so that background noise can be reduced. In this embodiment, the temperature rise threshold is calculated by setting n to 4, and the temperature rise threshold is set to about 0.1 (ΔK).

  However, the present invention is not limited to n = 4 in formula (4).

  In step S10 (determination step), the control unit 7 calculates a reference temperature value for each data pixel of the moving image of the liquid crystal panel 2 that has not been heated and is read in step S7 before voltage application. Here, the reference temperature value is a temperature value corresponding to the background image created by the method shown in FIG.

  In step S11 (determination step), the control unit 7 calculates a temperature increase value for each data pixel of the moving image of the liquid crystal panel 2 that has generated heat since the voltage read in step S8 is applied. Here, the temperature rise value is expressed by the following equation (5):

Is calculated from

  In step S12 (determination step), it is determined whether or not the temperature increase value has exceeded a preset temperature increase threshold value.

  In step S13 (specific process), a data image including the pixel whose temperature rise value is determined to be greater than or equal to the threshold value in step S12 and the image including the pixel determined to be less than the threshold value is converted into a binarized image. Here, Fig.6 (a) shows the infrared image after heat_generation | fever. In FIG. 6A, there are a plurality of portions indicating that heat is generated. In the liquid crystal panel 2, the heat generation portion is on the wiring line leading to the defect portion 23 and in the vicinity thereof. The defective part 23 itself does not generate heat. On the other hand, FIG. 6B is a binarized image of the captured image shown in FIG. In this binarized image, since it is difficult to separate the defect and the background, a large amount of background noise remains, and the position of the defect portion 23 cannot be accurately specified directly from the binarized image. Therefore, in the present embodiment, it is possible to accurately specify the position of the defect portion 23 by subsequent steps.

  In step S14, the linear image comprised by the pixel from which the temperature rise value was judged to be more than a threshold value from the binarized image produced in step S13 is specified. FIG. 6B shows a linear image. Here, in this embodiment, this line is defined as a rectangular region having a pair of long sides and a pair of short sides. That is, the line is considered to have a certain length (that is, the line width) in the direction perpendicular to the extending direction.

  In step S15, the extending direction of the long side of the rectangular area specified in step S14 is detected. The extending direction of the wiring of the liquid crystal panel 2 is recorded in advance in the data recording unit as information, and the extending direction is efficiently identified by comparing the information with the captured image. At the time of step S15, the length of the long side and the length of the short side can be determined only by specifying the extending direction of the long side of the pair of long sides and the pair of short sides constituting the rectangular region. I do not know the position (ie, the edge of the long side) and its length.

  In step S16, a certain range including the rectangular area specified in step S15 is specified as an inspection area. The certain range is a partial area in the post-macrothermographic image corresponding to the area determined as the active area of the inspection target cell by the thermo inspection apparatus.

  In step S17, an X-axis projection profile (first projection profile) is created by taking the X axis parallel to the long side of the rectangular area specified in step S15 for the image of the inspection area specified in step S16. . FIG. 7A shows a projection profile result in the X direction.

  In step S18, a projection peak position (a portion surrounded by a broken line in FIG. 7A) is specified from the X-direction projection profile created in step S17.

  In step S19, a local region of a plurality of pixels centering on the peak position specified in step S18 is specified. FIG. 7B shows the local region.

  In step S20, a projection profile (second projection profile) in the Y direction perpendicular to the X axis is created for the image of the local region identified in step S19. FIG. 7B shows a projection profile result in the Y direction.

  In step S21, when the Y-direction projection profile created in step S20 is scanned and profile values less than the threshold value continue for a certain number of pixels, the position coordinates (in FIG. 7B) of the first pixel among the consecutive pixels. A location surrounded by a broken line) is specified as the position of the defect portion 23. Here, the threshold value can be set by a value obtained by dividing the projection profile value by the number of projections = (0.0 to 1.0). Further, the fixed pixel can be set at 5 to 10 pix.

  In this way, the presence or absence of a defect in each data pixel is determined by the control unit 10.

  In step S22, it is determined whether or not the detection has been completed for all the data pixels in the liquid crystal panel 2 being detected. If detection has not been completed for all data pixels in the liquid crystal panel 2 being detected, the process returns to step S11, and detection is started for the next data pixel to be detected. On the other hand, when the detection is completed for all the data pixels in the liquid crystal panel 2 being detected, the process proceeds to the next step S23.

  In step S23, it is determined whether or not the detection is completed in all the detection modes in the liquid crystal panel 2 being detected. Here, in the liquid crystal panel 2 being detected, if the detection is not completed in all the detection modes, the process returns to step S3, the connection of the probe 3 is switched so as to correspond to the next detection mode, and the defect detection is repeated. It is. On the other hand, in the liquid crystal panel 2 being detected, when the detection is completed in all the detection modes, the process proceeds to the next step S24.

  The above-described detection mode indicates a detection method (voltage application method) corresponding to the type of the defect portion 23 as shown in FIG. That is, the detection method corresponding to the short-circuit defect between the wiring X and the wiring Y in FIG. 5A, the detection method corresponding to the short-circuit defect between the wirings X in FIG. 5B, and FIG. These are three detection modes which are detection methods corresponding to short-circuit defects between the wires Y.

  In step S24, it is determined whether or not the defect detection has been completed for all of the liquid crystal panels 2 for the mother substrate 1 being detected. Here, when the defect detection is not completed in all the liquid crystal panels 2, the process returns to step S2, the probe is moved to the next liquid crystal panel 2 to be detected, and the defect detection is repeated. On the other hand, when the defect detection is completed in all of the liquid crystal panels 2, the wiring defect detection is completed.

(3) Effects of this embodiment According to this embodiment, an image is projected in a direction orthogonal to the longitudinal direction of the line area, that is, in the short side direction of the rectangular area, and a predetermined threshold value is continuously obtained in the projection result. The position of a pixel that is less than the specified value is specified, and this is used as the tip position of the line area. As a result, the conventional method of identifying the tip position of a line region using the Hough transform for detecting line segments in any direction may cause many false detections when applied to the entire image with a lot of background noise. If the configuration of this embodiment is adopted, the tip position can be specified with high accuracy because the tip position of the line segment can be specified after selecting the region including the line segment from the entire image.

  In other words, the Hough transform of the conventional method is a method in which line segments in all directions are detected, and thus many false detections occur when applied to the entire image with much background noise. On the other hand, in the method of the present embodiment, the condition that the line segment to be detected is only in two directions, horizontal and vertical (in the thermo inspection apparatus, alignment correction is performed so that the inclination of the substrate is eliminated before inspection. The substrate wiring is formed on the substrate. The heat generation of the board wiring is observed only in two directions, horizontal or vertical, because they are arranged in parallel to each other. Therefore, the tip position of the line segment can be specified while suppressing the influence of background noise as compared with the conventional method. The region including the line segment is selected from the entire image based on the first projection profile data, and the tip position of the line segment is specified from the selected region based on the second projection profile data.

Further, according to the method of the present embodiment, the image is not a well-rectified rectangle, and the image is displayed in the short side direction even when the outer shape is uneven or the heating line width is changed. Since it is converted into one-dimensional data by projection, the heating line width is about 3 to 5 pix (2.54 to 4.24 mm), with the condition that the heating line width is within the short side width of the rectangular region. Therefore, within this range, the short side width of the rectangular area can be controlled. In the case where the heating line is divided, the tip position (defect position) is specified by connecting the regions divided by the closing of the image and then performing the above-described first and second projection profiles. can do.
(4) Modification In this modification, the apparatus similar to the apparatus in the above embodiment is used, and the applied voltage V (volt) is set as follows so as to differ from the embodiment.

  In the above-described embodiment, in step S6, the applied voltage V (volt) proportional to the square root of the resistance value acquired in step S4 is applied to the liquid crystal panel 2. On the other hand, in this modification, an applied voltage V (volt) proportional to the resistance value acquired in step S4 is applied to the liquid crystal panel 2 (FIG. 1B and FIG. 2).

  Specifically, in step S6 of the present embodiment, the applied voltage V (volt) is changed to the following formula (6);

And set. Here, the current I (ampere) is expressed by the following formula (7);

It becomes. That is, the current can be made constant by appropriately determining the applied voltage.

  Here, the resistance value R of the wiring formed on the substrate is expressed by the following equation (8);

The electrical resistivity ρ and the cross-sectional area A are constants determined by the type and location of the wiring. Therefore, the resistance value R / L = ρ / A of the wiring per unit length is also a constant. That is, if the number assigned to each wiring type and location is i, the resistance value r (i) per unit length of the wiring i is given by the following equation (9):

It is expressed.

  Therefore, the calorific value of the wiring i per unit length of the wiring i is expressed by the following formula (10) from the above formulas (2), (7) and (9):

It becomes.

  Here, FIG. 8 is a diagram for explaining the short-circuit path, and is an example of an electrical wiring diagram of the thin film transistor substrate. In the thin film transistor substrate of FIG. 8, scanning lines (wirings) 31 to 35 and signal lines (wirings) 41 to 45 are arranged in a grid pattern on a glass substrate, and thin film transistors and transparent pixel electrodes (not shown) are connected to each intersection. This is a substrate on which 5 × 5 pixels are formed as a whole. A thin film transistor substrate and a common electrode substrate (not shown) are arranged in parallel and a liquid crystal is sealed between them, which is a liquid crystal panel. Further, as shown in FIG. 8, the leading end portions of the scanning lines 31p to 35p of the scanning line are commonly connected to the thin film transistor substrate by the common line 30 to prevent electrostatic breakdown. The same applies to the signal lines. In the thin film transistor substrate shown in FIG. 8, a short-circuit portion 50 is formed between the scanning line 33 and the signal line 43. In such a thin film transistor substrate, considering the case where the short-circuit path is divided as lead line 33p → scan line 33 → short-circuit point 50 → signal line 43 → lead line 43p, the scan line 33 and signal per unit length are considered. The heat generation amount of the line 43 can be made constant.

  Accordingly, the scanning line 33 and the signal line 43 can be stably recognized from the infrared image by appropriately determining the constant m in advance regardless of the magnitude of the electrical resistance of the short-circuited portion.

  Then, by further analyzing the recognized wiring portion and specifying a portion where the scanning line 33 and the signal line 43 are short-circuited, the short-circuited portion can be specified. If the resistance value at the short-circuited portion is high, the amount of heat generated at the short-circuited portion increases, and therefore the short-circuited portion can be easily identified from the infrared image.

  Further, in order to determine the voltage based on the resistance value of the wiring, the control unit 7 may execute the process of calculating the above expression (1) each time. Alternatively, the relationship between the resistance value and the voltage may be stored in advance as a table, and the control unit 7 may refer to this table each time and determine the voltage from the resistance value.

  As mentioned above, although embodiment and the modification which concern on this invention were described, this invention is not limited to said embodiment and modification. Various modifications are possible within the scope of the claims.

  The present invention can be used for detecting the wiring state of a semiconductor substrate having wiring such as a liquid crystal panel.

1 Mother board (board)
2 Liquid crystal panel (substrate)
3 Probe (voltage application means)
4 Probe moving means 5, 5a, 5b Infrared camera 6 Camera moving means 7 Control unit (measuring means, specifying means)
8 Resistance measurement unit 9 Voltage application unit (voltage application means)
DESCRIPTION OF SYMBOLS 10 Data storage part 11 Alignment stage 12, 16 Optical camera 13a, 13b, 13c, 13d, 13e, 13f Guide rail 14a, 14b, 14d, 14d Mount part 17 Pixel part 18 Drive circuit part 19a, 19b, 19c, 19d Terminal part 21a, 21b, 21c, 21d Probe part 23 Defective part (wiring short circuit)
30, 40a, 40b Common lines 31, 32, 33, 34, 35 Scan lines 31p, 32p, 33p, 34p, 35p Scan line leader lines 41, 42, 43, 44, 45 Signal lines 41p, 42p, 43p, 44p, 45p Signal line lead line 50 Short circuit point 100 Wiring defect detection device

Claims (7)

A tip position specifying method for specifying a tip position of a line area displayed as an image,
The line area displayed as an image is defined as a rectangular area, a first projection profile is created along the long side of the rectangular area for the image of the inspection area including the rectangular area, and the peak position of the first projection profile A second projection profile is created along the short side of the rectangular area displayed in the image for a local area of a plurality of pixels centered on, and the profile value less than a predetermined threshold is obtained by scanning the second projection profile. A tip position specifying method including a specifying step of specifying, as the tip position, a pixel position that first shows a profile value less than the predetermined threshold value when it is determined that a certain number of pixels are continuous.   The tip position specifying method according to claim 1, wherein images used for the first projection profile and the second projection profile are binarized images. A position specifying method for specifying a position of a short-circuit defect in a wiring formed on a substrate,
A voltage applying step of applying a predetermined voltage to the wiring;
A measuring step of continuously measuring a temperature of at least a part of the region of the semiconductor substrate to which a voltage is applied in the voltage applying step using an infrared camera;
A determination step of determining whether a temperature rise value derived by subtracting the temperature value of the semiconductor substrate before applying the voltage from the temperature value measured in the measurement step is equal to or greater than a threshold value;
The display image of the line area corresponding to the wiring including the pixel for which the temperature rise value is determined to be equal to or greater than the threshold and the pixel for which the temperature increase value is less than the threshold in the determination step is defined as a rectangular area, and the image of the inspection area including the rectangular area In contrast, a first projection profile parallel to the long side of the rectangular region is created, and a plurality of pixel local regions centered on the peak position of the first projection profile are parallel to the short side of the rectangular region. A second projection profile is created, and when the second projection profile is scanned and a profile value less than a predetermined threshold value is determined to be continuous for a certain number of pixels, the predetermined threshold value is the first of the consecutive pixels. And a specifying step of setting a position of a pixel exhibiting a profile value less than the position of the short-circuit defect. The position specifying method according to claim 3, further comprising a voltage applying unit that applies the voltage and an alignment adjusting step that adjusts a position of the substrate with respect to the infrared camera before the voltage applying step. A tip position specifying device for specifying the tip position of a line area displayed as an image,
The line area displayed as an image is defined as a rectangular area, a first projection profile is created along the long side of the rectangular area for the image of the inspection area including the rectangular area, and the peak position of the first projection profile A second projection profile is created along the short side of the rectangular area displayed in the image for a local area of a plurality of pixels centered on, and the profile value less than a predetermined threshold is obtained by scanning the second projection profile. A tip position specifying device comprising a specifying means for specifying, as the tip position, the position of a pixel that first shows a profile value less than the predetermined threshold when it is determined that a certain number of pixels are continuous. . A position specifying device for specifying a position of a short-circuit defect of wiring formed on a substrate,
Voltage applying means for applying a predetermined voltage to the wiring;
An infrared camera for photographing the above wiring;
Measuring means for measuring the temperature of at least a part of the substrate including the wiring using the infrared camera;
It is determined whether or not a temperature rise value derived by subtracting the temperature value of the semiconductor substrate before applying the voltage from the temperature value measured by the measuring means is equal to or greater than a threshold value. The display image of the line area corresponding to the wiring including the pixels determined to be above and the threshold value is defined as a rectangular area, and the length of the rectangular area with respect to the image of the inspection area including the rectangular area Creating a first projection profile parallel to the side, creating a second projection profile parallel to the short side of the rectangular region for a local region of a plurality of pixels centered on the peak position of the first projection profile; When the second projection profile is scanned and it is determined that the profile value less than the predetermined threshold is continuous for a certain number of pixels, the image that first shows the profile value less than the predetermined threshold among the continuous pixels. Position, position specifying device which is characterized by comprising a specifying means for the position of the short circuit defects. An alignment stage for placing the substrate;
The position specifying device according to claim 6, further comprising an alignment adjusting unit that adjusts a position of the substrate with respect to the voltage applying unit and the infrared camera.