JP5701818B2 - Defect inspection apparatus, defect inspection method, defect inspection program, and recording medium - Google Patents

Description

  The present invention relates to a defect inspection apparatus for inspecting defects in wiring formed on a substrate.

  Conventionally, in a manufacturing process of a liquid crystal panel or the like, after a semiconductor element such as a TFT (thin film transistor), a wiring, a circuit, etc. are formed on a transparent substrate, an array inspection for inspecting the semiconductor element or the wiring for a defect due to a short circuit or disconnection Has been done.

  Usually, in the array inspection, a probe is brought into contact with an end portion of a wiring, and the presence or absence of a short circuit is inspected by conducting a continuity test that measures the electrical resistance at both ends of the wiring or between the adjacent wirings. However, even if such a continuity test alone can identify the presence or absence of a defect such as a wiring, the position of the defect may not be identified. For this reason, there is a need for a technique for identifying not only the presence / absence of a defect but also the position of the defect.

  On the other hand, for example, Patent Document 1 discloses an inspection apparatus that uses a fact that a defective portion of a substrate generates heat by energization to identify a heat generating portion appearing in an infrared image obtained by imaging the substrate as a defective portion.

JP-A-6-207914 (published July 26, 1994)

  In the inspection based on the infrared image as described above, it is possible to identify the defective portion, but it is impossible to monitor that the voltage is normally applied to the substrate in the above-described conduction inspection. For this reason, even if there is a defect, if the voltage is not normally applied to the substrate due to an abnormality in the power supply system etc., heat will not be generated at the defective part, so the heat generating part will also be detected by infrared image Can not do it.

  In the first place, since the frequency of occurrence of such defects is not high, it can be said that there are no defects on the majority of substrates. However, since the case as described above is also assumed, the fact that the defect is not specified does not always directly relate to the fact that there is no defect. In addition, regardless of whether or not voltage application to the substrate is normal, no heat generation occurs unless there is a defect on the substrate. Therefore, the presence or absence of a defect cannot be determined only by looking at the infrared image.

  For example, FIG. 11A shows a state of the substrate 201 when inspecting a defect in the active area 202 where the thin film transistor is formed in the substrate 201 to be inspected. In the substrate 201, when a voltage is normally applied to the substrate 201, a defective portion in the active area 202 appears as a heat generation portion F in the infrared image. Further, as shown in FIG. 11B, when there is no defective portion on the substrate 201, there is no portion that generates heat when the voltage is normally applied to the substrate 201. Such a heat generation point F is not detected. Further, when no voltage is applied to the substrate 201, as shown in FIG. 11C, the heat generation point F as shown in FIG. 11A is not detected regardless of the presence or absence of a defective portion.

  Therefore, when no voltage is applied, the substrate including the defective portion is not substantially inspected. If a substrate including a defective part is used as a non-defective product in a state where it has not been substantially inspected in this way, the product in which the substrate is incorporated becomes a defective product as a result. It was. Therefore, in the defect inspection of the board | substrate by an infrared image, the improvement of reliability was calculated | required.

  The present invention has been made in view of the above problems, and an object thereof is to provide a highly reliable defect inspection apparatus.

  In order to solve the above-described problem, the defect inspection apparatus according to the present invention is an infrared camera that images a substrate including a region to be inspected having a plurality of wirings, and a voltage applying unit that applies a voltage to the wirings of the substrate. In the infrared image obtained by imaging with the infrared camera, the presence or absence of the application of the voltage to the inspection area is determined based on the presence or absence of heat generation of the heat generating portion provided on the substrate and generating heat by the application of the voltage. Voltage application determination means for determining, and defect detection means for detecting, as a defect, a heat generation location in the inspection area based on the infrared image, when energization to the inspection area is determined by the voltage application determination means. It is characterized by having.

  In order to solve the above-described problem, a defect inspection method according to the present invention applies a voltage application process for applying a voltage to the wiring of a substrate including a region to be inspected having a plurality of wirings, and the substrate using an infrared camera. Based on the presence / absence of heat generation of a heat generating portion provided on the substrate and generating heat by applying a voltage to the substrate in an infrared image obtained by imaging with a substrate imaging process and imaging by the infrared camera, to the inspection area A voltage application determination process for determining the presence or absence of the application of the voltage, and when the energization to the inspection area is determined by the voltage application determination process, a heat generation location in the inspection area is determined based on the infrared image. And a defect detection process for detecting as a defect.

  In the above configuration, when the voltage is correctly applied to the substrate by the voltage applying means (voltage applying process), the heat generating portion generates heat. In this state, since the heat generating portion appears as a heat generation location in the infrared image captured by the infrared camera (substrate imaging process), the voltage is applied to the inspection area by the voltage application determining means (voltage application determining process). Is determined. Then, when a defect such as a short circuit has occurred in the inspection region, the heat generation location in the inspection region is detected as a defect based on the infrared image by the defect detection means (defect detection processing).

  On the other hand, when the voltage is not correctly applied to the substrate, the heat generating portion does not generate heat. In this state, since the heat generating portion does not appear as a heat generating portion in the infrared image, it is determined by the voltage application determination means (voltage application determination processing) that no voltage is applied to the inspection region.

  In this way, by determining whether or not a voltage is applied to the inspection region, it is possible to appropriately inspect the inspection region using the infrared image in a state where the voltage is applied to the inspection region. it can. Therefore, it is possible to avoid the inconvenience that a correct inspection result cannot be obtained by performing the defect inspection even though the voltage is not applied to the inspection region.

  In the defect inspection apparatus, it is preferable that the heat generating portion is a protection circuit that protects the wiring. Moreover, it is preferable that the said protection circuit consists of two switching elements which make a diode ring structure connected between the two said adjacent wiring.

  In the configuration described above, it is not necessary to newly provide a circuit or the like serving as a heat generating portion on the substrate. Thus, an existing mask can be used as a mask for manufacturing the substrate. Therefore, since it is not necessary to prepare a new mask including the new circuit as described above, it is possible to perform an energization inspection of the region to be inspected at a reduced cost.

  Alternatively, in the defect inspection apparatus, the plurality of substrates are formed on a mother substrate, and the heat generating portion is provided in a non-substrate region of the mother substrate where the substrate is not formed, and generates heat by applying the voltage. It is preferable that the heat generating wiring be used. The heating wiring is preferably made of gold or copper.

  In the above configuration, by using the heat generating wiring provided in the non-substrate region as the heat generating portion, it is not necessary to separately provide a circuit or the like used as the heat generating portion on the substrate. Further, since the heat generating wiring is formed in the non-substrate region, when the substrate is separated from the mother substrate, the non-substrate region including the heat generating wiring is separated. Therefore, the heat generation wiring does not affect the divided substrate.

  The defect inspection program of the present invention is a program for causing a computer to function as each process in the defect inspection method. The recording medium of the present invention is a computer-readable recording medium on which the defect inspection program is recorded. These defect inspection programs and recording media are also included in the technical scope of the present invention.

  By being configured as described above, the defect inspection apparatus according to the present invention has an effect that it is possible to more reliably confirm the application of a voltage to a substrate to be inspected for defects by an infrared image.

It is a perspective view which shows the structure of the external appearance of the defect inspection apparatus which concerns on Embodiments 1-3 of this invention. (A) is a top view which shows the structure of the TFT substrate which the said defect inspection apparatus inspects, and (b) is a top view which expands and shows a part of structure of the wiring in the said TFT substrate. It is a circuit diagram which shows the structure of the protection circuit provided in the said TFT substrate. It is a clear plan view showing a configuration of a probe frame provided in the defect inspection apparatus. It is a block diagram which shows the structure of the control system in the said defect inspection apparatus. It is a flowchart which shows the procedure of operation | movement of the said defect inspection apparatus. (A)-(c) is a figure which shows the test result by the electricity supply test method of the TFT substrate which concerns on Embodiment 2 of this invention. (A), (b) is a figure which shows the other test result by the electricity supply test method of the TFT substrate which concerns on Embodiment 2 of this invention. (A) is a top view which shows the structure of the mother board | substrate used for the electricity supply inspection method which concerns on Embodiment 3 of this invention, (b) is a top view which expands and shows a part of the said mother board | substrate. (A), (b) is a figure which shows the test result by the electricity supply test method which concerns on Embodiment 3. FIG. (A)-(c) is a figure which shows the test result by the conventional defect inspection apparatus.

  Embodiments according to the present invention will be described below with reference to FIGS.

[Embodiment 1]
[Mechanical structure of defect inspection system]
FIG. 1 is a perspective view schematically showing a configuration of a defect inspection apparatus 100 common to the first to third embodiments of the present invention.

  In the following description, the X direction, the Y direction, and the Z direction are used to indicate directions. The Z direction is a vertical direction, and the X direction, the Y direction, and the Z direction are orthogonal to the other two directions.

  As shown in FIG. 1, the defect inspection apparatus 100 is an apparatus for inspecting defects such as wiring in a plurality of TFT substrates 2 (substrates) formed on a mother substrate 1. The defect inspection apparatus 100 includes a probe frame 3, a first infrared camera 4, a second infrared camera 5, an optical camera 6, a base 7, an alignment stage 8, a camera moving device 9, a probe moving device 10, and mounts 11 to 14. I have.

  An alignment stage 8 is installed on the base 7. The mother substrate 1 is placed on the alignment stage 8. The base 7 has guide rails 7 a and 7 b provided on both sides of the alignment stage 8. One guide rail 7 a is arranged on each side of the alignment stage 8 so that each longitudinal direction is along the X direction. Further, one guide rail 7b is disposed on both sides of the alignment stage 8 and on the outer side of the guide rail 7a in parallel with the guide rail 7a.

  The guide rail 7a is provided as a track for guiding the probe moving device 10 in the X direction. The guide rail 7b is provided as a track for guiding the camera moving device 9 in the X direction.

  The alignment stage 8 is provided with a position adjusting device (not shown). With this position adjusting device, the wiring forming surface of the mother substrate 1 placed on the alignment stage 8 is parallel to the X direction and the Y direction. As described above, the position of the mother substrate 1 is adjusted. The mother substrate 1 includes a plurality of TFT substrates 2 used for liquid crystal panels. In the present embodiment, one mother substrate 1 includes eight TFT substrates 2 arranged in a matrix of 4 (X direction) × 2 (Y direction).

  The camera moving device 9 is installed so as to be movable on the guide rail 7b. The camera moving device 9 has a pair of leg portions 9a, a beam portion 9b, and a guide rail 9c.

  The leg portions 9 a are disposed on the guide rail 7 b so as to face each other on both sides of the alignment stage 8. Both ends of the beam portion 9b are connected to the upper end of the leg portion 9a. The leg portion 9a and the beam portion 9b constitute a gantry.

  The guide rail 9c is arrange | positioned so that the longitudinal direction may follow the Y direction on the side surface of the beam part 9b. Mounts 11 to 13 are attached to the guide rail 9c so as to be movable in the Y direction.

  The mount 11 has a frame 11a, and four first infrared cameras 4 are mounted on the frame 11a. Each first infrared camera 4 is mounted on a mount 11 that is moved by a camera moving device 9, so that the first infrared camera 4 can move in the X direction and the Y direction while maintaining a constant distance from the TFT substrate 2.

  The mount 12 has one second infrared camera 5 mounted thereon, and moves the second infrared camera 5 in the Z direction (vertical direction). The mount 13 carries one optical camera 6 and moves the optical camera 6 in the Z direction. The second infrared camera 5 and the optical camera 6 can be moved in the X direction, the Y direction, and the Z direction by being mounted on the mounts 12 and 13 that are moved by the camera moving device 9, respectively.

  The first infrared camera 4 is a camera (thermo viewer) that performs imaging with infrared rays in order to detect the heat generation state of each TFT substrate 2 on the mother substrate 1. The first infrared camera 4 is provided for macro measurement, and the field of view is expanded to about 520 mm × 405 mm.

  Similar to the first infrared camera 4, the second infrared camera 5 is a camera (thermo viewer) that performs imaging with infrared rays in order to detect the heat generation state of each TFT substrate 2. The second infrared camera 2 is provided for micro measurement, has a small field of view of 32 mm × 24 mm, and can perform high-resolution imaging.

  The optical camera 6 is a camera that takes images of the TFT substrate 2 and the probe frame 3 in order to adjust the position when the probe frame 3 is arranged around the TFT substrate 2 to be inspected. In addition, the optical camera 6 may be used for the purpose of photographing the TFT substrate 2 in order to monitor the state of the TFT substrate 2.

  The probe moving device 10 is installed so as to be movable on the guide rail 7a. The probe moving device 10 has a pair of leg portions 10a, a slide rail 10b, and a guide rail 10c.

  The leg portions 10a are arranged on the guide rail 7a so as to face each other on both sides of the alignment stage 8. The leg portion 10a has a moving direction defined by the guide rail 7a, and is configured to be able to move on the guide rail 7a. Further, although not shown, the leg portion 10a is equipped with a power supply device that generates a voltage to be applied to the TFT substrate 2.

  The slide rail 10b has two rail portions extending in the Y direction and a support portion supported by the leg portion 10a. The rail portions are arranged in parallel and hold the mount 14 on which the probe frame 3 is mounted on both sides so as to be slidable in the Y direction.

  Two guide rails 10c are provided on the side surface of the leg portion 10a on the alignment stage 8 side so that the longitudinal direction thereof is along the Z direction. The guide rail 10c supports the slide rail 10b with a support portion so as to move the slide rail 10b in the Z direction.

  The probe frame 3 can be moved in the X direction by the leg 10a, moved in the Y direction by the slide rail 10b, and moved in the Z direction by the guide rail 10c.

[Configuration of TFT substrate]
FIG. 2A is a plan view showing the configuration of the TFT substrate 2, and FIG. 2B is an enlarged plan view showing a part of the configuration of the wiring in the TFT substrate 2. As shown in FIG. FIG. 3 is a circuit diagram showing a configuration of a protection circuit provided on the TFT substrate 2.

  As shown in FIG. 2A, the TFT substrate 2 is provided with an active area 21, a peripheral circuit portion 22, and terminal portions 23 and 24.

  The active area 21 (inspected area) is an area for displaying an image, and is composed of a plurality of pixel portions 211 arranged in a matrix as shown in FIG. The pixel portion 211 is provided such that a plurality of scanning lines 212 (wiring) and a plurality of signal lines 213 (wiring) provided around the pixel portion 211 intersect each other. In the pixel portion 21, switching elements made of TFTs (thin film transistors) (not shown) are formed at respective intersections of the scanning lines 212 and the signal lines 213, and are arranged in a matrix.

  As shown in FIG. 2B, the peripheral circuit unit 22 is formed with a peripheral circuit 221 (source driver, gate driver, etc.) for driving the liquid crystal panel, a protection circuit 222, wiring for connecting each circuit, and the like. Has been. FIG. 2B shows a gate driver to which the scanning line 212 is connected and a source driver to which the signal line 213 is connected as the peripheral circuit 221.

  The protection circuit 222 is provided on the TFT substrate 2 between the adjacent scanning lines 212 and between the adjacent signal lines 213. All the protection circuits 222 are similarly configured.

  As shown in FIG. 3, the protection circuit 222 has a diode ring structure in which two diode-connected switching elements (semiconductor elements) 222a and 222b are connected in opposite directions and in parallel.

  In the switching element 222a of the protection circuit 222, the source and the gate are short-circuited. The switching element 222a functions as a diode because the source and the gate are short-circuited. The source and gate of the switching element 222a are electrically connected to the drain of the switching element 222b and one of the wirings of the scanning line 212 and the signal line 213. The drain of the switching element 222a is electrically connected to a wiring adjacent to the wiring to which the source and gate are connected, and is connected to the source and gate of the switching element 222b. On the other hand, the switching element 222b is short-circuited between the source and the gate. The switching element 222b functions as a diode because the source and the gate are short-circuited.

  When the charge is generated in the scanning line 212, the protection circuit 222 configured as described above releases the charge to the adjacent scanning line 212 via the switching element 222a or the switching element 222b. Similarly, when a charge is generated in the signal line 213, the protection circuit 222 releases the charge to the adjacent signal line 213 through the switching element 222a or the switching element 222b.

  As described above, when a high voltage due to static electricity is applied to one of the scan line 212 and the signal line 213, the protective circuit 222 causes charge to flow into another adjacent line, and the electric field concentrates on the specific line. Can be avoided. Therefore, it is possible to prevent the occurrence of defects in the TFT substrate 2 due to electrostatic breakdown.

  The terminal portion 23 is provided at two opposing peripheral portions on the source driver side of the TFT substrate 2. The terminal portion 24 is provided at two opposing peripheral portions on the gate driver side of the TFT substrate 2. As shown in FIG. 2B, the terminal portion 23 includes a terminal 231 including a plurality of gate driver side input terminals and various connection terminals. On the other hand, the terminal unit 24 includes a terminal 241 including a plurality of source driver side input terminals and various connection terminals. The source driver side input terminal is a terminal for inputting various signals to the source driver for outputting data to the signal line 213 in the peripheral circuit 221. The gate driver side input terminal is a terminal for inputting various signals to the gate driver for outputting the scanning signal to the scanning line 212 in the peripheral circuit 221.

[Configuration of probe frame]
FIG. 4 is a plan view showing the configuration of the probe frame 3. FIG. 5 is a block diagram illustrating a configuration of a control system of the defect control apparatus 100.

  As shown in FIGS. 4 and 5, the probe frame 3 includes a frame portion 31, a plurality of probe needles 32, and a voltage application portion 33.

  The frame portion 31 has a shape corresponding to the outer peripheral edge portion of the TFT substrate 2 so that the shape of the inner edge portion surrounds the TFT substrate 2 shown in FIG. The frame portion 31 is arranged so that the TFT substrate 2 to be inspected is located in a region opened inside thereof. Moreover, the frame part 31 incorporates the voltage application part 33 shown in FIG.

  Each probe needle 32 is provided on the inner edge portion of the frame portion 31 so as to protrude inward. Each probe needle 32 is arranged at a position corresponding to each terminal of the terminal portions 23 and 24 installed on the TFT substrate 2.

  Accordingly, when the probe frame 3 is moved so that the TFT substrate 2 to be inspected is located in the region inside the frame portion 31, the terminals 231 and 241 of the probe needles 32 and the terminal portions 23 and 24 of the TFT substrate 2 are detected. And contact. Further, the active area 21 and the peripheral circuit portion 22 are covered with the probe frame 3 in a state where the probe needles 32 and the terminals 231 and 241 are in contact with each other because the TFT substrate 2 is located in the region inside the frame portion 31. It exposes without.

  The voltage application unit 33 (voltage application means) applies the voltage obtained from the power supply device described above to one or a plurality of wires connected to each probe needle 32. The voltage application unit 33 is individually connected to each probe needle 32 via a switching relay (not shown). Thereby, the voltage application unit 33 can selectively apply a voltage to one or more desired wirings among the wirings connected to each probe needle 32.

[Configuration of control system for defect inspection system]
FIG. 5 is a block diagram showing the configuration of the control system of the defect inspection apparatus 100.

  As shown in FIG. 5, the defect inspection apparatus 100 includes a control unit 51 and a data storage unit 52 that are provided for performing control as a control system. Further, the defect inspection apparatus 100 includes a gantry moving mechanism 53, a probe moving mechanism 54, a camera moving mechanism 55, a probe frame 3, and an infrared camera 4 as control targets.

  The gantry moving mechanism 53 is configured by a motor, a gear, or the like (not shown), and moves the gantry composed of the leg portion 9a and the beam portion 9b of the camera moving device 9 in the X direction along the guide rail 7b. It is. The gantry moving mechanism 53 is built in the leg portion 9a.

  The probe moving mechanism 54 is a mechanism configured by a motor, a gear, or the like (not shown). The probe moving mechanism 54 moves the probe moving device 10 in the X direction along the guide rail 7a. The probe moving mechanism 54 moves the probe frame 3 in the Y direction along the slide rail 10b. Further, the probe moving mechanism 54 moves the probe frame 3 in the Z direction along the guide rail 10c. A portion of the probe moving mechanism 54 that moves the probe moving device 10 in the X direction is built in the leg 10 a of the probe moving device 10.

  The camera moving mechanism 55 is configured by a motor, a gear, or the like (not shown), and moves the mounts 11 to 13 along the guide rail 9c in the Y direction. Further, the camera moving mechanism 55 moves the second infrared camera 5 attached to the mount 12 in the Z direction and moves the optical camera 6 attached to the mount 13 in the Z direction. In the camera moving mechanism 55, a portion for moving the mounts 11 to 13 is built in the beam portion 9 b of the camera moving device 9, a portion for moving the second infrared camera 5 is built in the mount 12, and a portion for moving the optical camera 6. Is built in the mount 13.

  The control unit 51 controls operations of the gantry moving mechanism 53, the probe moving mechanism 54, the camera moving mechanism 55, the voltage applying unit 33, the first and second infrared cameras 4 and 5, and the optical camera 6. Further, the control unit 51 determines the presence / absence of voltage application to the TFT substrate 2, the determination of the defect, and the specification of the defect position based on the infrared image data from the first infrared camera 4 and the second infrared camera 5. Therefore, the control unit 51 includes a position control unit 511, a voltage control unit 512, an imaging control unit 513, a voltage application determination unit 514, and a defect position specifying unit 515.

  The position control unit 511 controls operations of the gantry moving mechanism 53, the probe moving mechanism 54, and the camera moving mechanism 55. The position controller 511 controls the movement of the first and second infrared cameras 4 and 5, the optical camera 6 and the probe frame 3 in the X direction and the Y direction by controlling the operations of the mechanisms 53 to 55. Further, the position control unit 511 controls the movement of the probe frame 3, the second infrared camera 5, and the optical camera 6 in the Z direction.

  The voltage control unit 512 controls the operation of the voltage application unit 33 and the above-described power supply device and switching relay. Thereby, as described above, a desired voltage is selectively applied to one or a plurality of desired wirings among the wirings connected to each probe needle 32.

  The imaging control unit 513 controls the operations of the first infrared camera 4 and the second infrared camera 5 to capture an infrared image (thermo viewer image) of the TFT substrate 2. In addition, the imaging control unit 513 gives the data of the infrared image from the first infrared camera 4 and the second infrared camera 5 to the data storage unit 52 for storage.

  The voltage application determination unit 514 (voltage application determination unit) determines whether or not the voltage application by the voltage application unit 33 is correctly performed based on the data of the infrared image stored in the data storage unit 52. . Specifically, the voltage application determination unit 514 applies this energization when a voltage from the voltage application unit 33 is applied to a wiring or circuit (energization inspection unit) used for voltage application determination in the TFT substrate 2. The presence / absence of voltage application is determined based on the presence / absence of heat generation in the inspection unit.

  The energization inspection unit (heat generation unit) is connected to the terminals 231 and 241 described above, and is configured to generate heat when a voltage is applied from the voltage application unit 33. Therefore, the voltage application determination unit 514 determines that the voltage is normally applied if the above-described energization inspection unit generates heat. Further, the voltage application determination unit 514 determines that no voltage is applied if the above-described energization inspection unit is not generating heat, and informs the inspection operator of this using means such as a display. Further, the voltage application determination unit 514 stores the determination result in the data storage unit 52.

  The determination of voltage application by the voltage application determination unit 514 will be described in detail in Embodiments 1 and 2 described later.

  The defect position specifying unit 515 (defect detection means) determines whether or not there is a defect in the active area 21 of the TFT substrate 2 based on the infrared image data stored in the data storage unit 32, and if there is a defect. The defect is detected. Specifically, the defect position specifying unit 515 determines the presence / absence of a heat generation point in the active area 21 based on data of a portion corresponding to the active area 21 of the infrared image data, and if there is a heat generation point, the heat generation point Specify the position of. Further, the defect position specifying unit 515 causes the data storage unit 52 to store data (defect position data) regarding the position of the specified defect.

  The defect position specifying unit 515 performs the specifying process only when the voltage application determining unit 514 has determined that normal voltage application has been obtained.

  The data storage unit 52 stores data necessary for the control process of the control unit 51 and data generated in the process of performing the control process. In addition, the data storage unit 52 acquires and stores infrared image data necessary for determination processing by the voltage application determination unit 514 and the defect position specification unit 515 via the control unit 51. Further, the data storage unit 52 stores data about the position of the defect obtained as a result of the specifying process by the defect position specifying unit 515 for each TFT substrate 2.

  Each block of the control unit 51 is realized by software (defect inspection program) using a CPU as follows. That is, this defect inspection program causes the computer to function as each of the above blocks, thereby executing each process in the defect inspection method described later. Or each said block may be implement | achieved by the process by the program using DSP (Digital Signal Processor). Alternatively, each block of the control unit 51 may be configured by hardware logic.

  The program code (execution format program, intermediate code program, source program) of the above software may be recorded on a recording medium recorded so as to be readable by a computer. The object of the present invention can also be achieved by supplying the recording medium to the defect inspection apparatus 100 and reading and executing the program code recorded on the recording medium by the CPU.

  Examples of the recording medium include magnetic tapes such as magnetic tapes and cassette tapes, magnetic disks such as floppy (registered trademark) disks / hard disks, and optical disks such as CD-ROM / MO / MD / BD / DVD / CD-R. Can be used. In addition, as the recording medium, a card system such as an IC card (including a memory card) / optical card or a semiconductor memory system such as a mask ROM / EPROM / EEPROM (registered trademark) / flash ROM can be used. .

  Moreover, the defect inspection apparatus 100 may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. As this communication network, for example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication network, etc. can be used. It is. In addition, a wired medium or a wireless medium can be used as a transmission medium constituting the communication network. Examples of the wired medium include IEEE 1394, USB, power line carrier, cable TV line, telephone line, ADSL line, and the like. Examples of the wireless medium include infrared rays such as IrDA and remote control, Bluetooth (registered trademark), 802.11 wireless, HDR, mobile phone network, satellite line, terrestrial digital network, and the like.

  The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

[Operation of defect inspection system]
Here, an operation (defect inspection method) at the time of defect detection processing by the defect inspection apparatus 100 will be described.

  FIG. 6 is a flowchart showing an operation of the operation of the defect inspection apparatus 100.

  First, the position adjustment (alignment) of the mother substrate 1 placed at a predetermined position is performed on the alignment stage 8, and the inspection starts in this state.

  The probe moving device 10 moves the probe frame 3 to a position corresponding to the TFT substrate 2 to be inspected, and the camera moving device 9 moves the first infrared camera 4, the second infrared camera 5, and the optical camera 6 to the probe frame. It moves like 3 (step S1). At this time, the position control unit 511 controls the operations of the gantry moving mechanism 53, the probe moving mechanism 54, and the camera moving mechanism 55. Thereby, when the probe frame 3 moves to the TFT substrate 2 to be inspected and is arranged around the TFT substrate 2, the probe needle 32 of the probe frame 3 is in the terminal portions 23 and 24 of the TFT substrate 2. Contact the terminals 231 and 241.

  Next, the voltage application unit 33 applies a voltage to the TFT substrate 2 (step S2, voltage application process). At this time, the voltage control unit 512 controls the operation of the voltage application unit 33 so that the voltage application unit 33 applies a voltage to the terminals 231 and 241 of the terminal units 23 and 24 in the TFT substrate 2.

  In this state, the first infrared camera 4 and the second infrared camera 5 image the entire TFT substrate 2 (step S3, substrate imaging process). At this time, the imaging control unit 514 controls the operations of the first infrared camera 4 and the second infrared camera 5. Thereby, the first infrared camera 4 and the second infrared camera 5 capture the entire area of the inspection target area including the active area 21 and the peripheral circuit portion 22 of the TFT substrate 2 by one imaging process. The infrared image data from the first infrared camera 4 and the second infrared camera 5 obtained by this imaging is stored in the data storage unit 52.

  Then, the voltage application determination unit 514 confirms the presence / absence of heat generation in the energization inspection unit used for voltage application determination in the TFT substrate 2 based on the infrared image data (step S4, voltage application determination processing). . At this time, in the state where the voltage from the voltage application unit 33 is normally applied to the TFT substrate 2, the voltage is also applied to the current inspecting unit via the terminals 231 and 241 of the terminal units 23 and 24. The energization inspection unit generates heat. In addition, since the voltage from the voltage application unit 33 is not normally applied to the TFT substrate 2 due to an abnormality in the power supply system such as the power supply device, the voltage application unit 33, and the voltage application wiring, the voltage is not applied to the conduction inspection unit. The energization inspection part does not generate heat.

  In step S4, when the voltage application determination unit 514 confirms the heat generation of the energization inspection unit (YES), the voltage application unit 33 applies a voltage to the TFT substrate 2 to be inspected in the same manner as in step S2 (step S5). . In this state, the first infrared camera 4 and the second infrared camera 5 image the entire TFT substrate 2 in the same manner as in step S3 (step S6). The infrared image data from the first infrared camera 4 and the second infrared camera 5 obtained by this imaging is stored in the data storage unit 52.

  Thereafter, the defect position specifying unit 515 confirms the presence or absence of a heat generation location in the active area 21 of the TFT substrate 2 based on the infrared image data stored in the data storage unit 52 (step S7). At this time, since the voltage from the voltage application unit 33 is normally applied to the TFT substrate 2, the voltage is applied to the active area 21 via the terminals 231 and 241 of the terminal units 23 and 24. When a defect such as a short circuit occurs in any one of the scanning lines 212, the signal lines 213, the adjacent scanning lines 212, and the adjacent signal lines 213 in the active area 21, the defective portion generates heat by application of a voltage. Further, when no defect occurs in the active area 21, no heat is generated.

  In step S7, when the defect position specifying unit 515 confirms the heat generation in the active area 21 (YES), the defect position specifying unit 515 detects the heat generation point as a defect point and specifies the position of the defect point (step S8, defect detection process). And the defect position specific | specification part 515 memorize | stores the information about the position of the specified defect in the data storage part 32 (step S9).

  Further, the control unit 51 determines whether or not the inspection has been completed for all the TFT substrates 2 in the mother substrate 1 being inspected (step S10). Here, when it is determined that there is an uninspected TFT substrate 2, the control unit 51 returns to the process of Step S1 and inspects the next TFT substrate 2. If the control unit 51 determines that there is an uninspected TFT substrate 2, the inspection process for the mother substrate 1 is finished.

  In step S4, if the voltage application determination unit 514 does not confirm the heat generation of the energization inspection unit (NO), the voltage application determination unit 514 notifies the inspection operator that the voltage is not normally applied to the TFT substrate 2. (Step S11), the inspection process ends.

  Thus, the inspection operator can confirm the abnormality of the power supply system, and if the abnormality is found, can cope with the recovery of the power supply system. Here, in the infrared image, voltage non-application can be easily confirmed because there is no heat generation in the energization inspection unit, but by notifying, voltage non-application can be more reliably confirmed.

  In step S7, if the defect position specifying unit 515 does not confirm heat generation in the active area 21 (NO), the process proceeds to step S10.

[Effects of defect inspection equipment]
As described above, in the defect inspection apparatus 100 according to the present embodiment, the TFT substrate 2 has the conduction inspection unit. The energization inspection unit is a portion to which a voltage is applied simultaneously with the active area 21, and generates heat when the voltage is applied. As a result, when the energization inspection unit generates heat by voltage application, it can be confirmed that the voltage is correctly applied to the active area 21. In addition, when the voltage application does not generate heat in the energization inspection unit, it can be confirmed that no voltage is applied, and it is considered that some abnormality has occurred in the power supply system from the power supply device to the energization inspection unit.

  As described above, by checking the presence / absence of energization in the active area 21, it is possible to appropriately inspect the defect in the active area 21 using the infrared image in a state where the energization to the active area 21 is ensured. Therefore, it is possible to avoid the inconvenience that a correct inspection result cannot be obtained by performing a defect inspection even though the active area 21 is in a non-energized state. Therefore, it is possible to improve the reliability of the inspection and improve the direct rate.

[Realization 2]
As the second embodiment of the present invention, the above-described energization inspection unit will be specifically specified and described.

  FIGS. 7A to 7C are diagrams showing the inspection results obtained by the current inspection method for the TFT substrate 2 according to the second embodiment. FIGS. 8A and 8B are diagrams illustrating other inspection results obtained by the current-carrying inspection method for the TFT substrate 2.

  In the present embodiment, the protection circuit 222 (diode ring structure) in the peripheral circuit unit 22 described above is used as the energization inspection unit. The protection circuit 222 (heating unit) configured as described above generates heat when a current flows by applying a high voltage. Conventionally, since such heat generation is detected as a defect even though it is not an original defect, a portion such as the protection circuit 222 that constantly generates heat when energized has been excluded from the inspection target.

  In the present embodiment, such a protection circuit 222 is used as an energization inspection unit. As a result, as shown in FIG. 7A, when a voltage is applied to the TFT substrate 2, the protection circuit 222 in the peripheral circuit section 22 generates heat. This appears as a heat generation point F1 in the infrared image. Therefore, it can be seen that in this state, the voltage is normally applied also to the active area 21.

  When there is a defect in the active area 21 of the TFT substrate 2, the portion generates heat, so that a heat generation portion F2 appears in the infrared image as shown in FIG. 7B. On the other hand, when there is no defect in the active area 21 of the TFT substrate 2, the portion does not generate heat, so that the heat generation portion F2 as described above does not appear in the infrared image as shown in FIG. 7C.

  When no voltage is applied to the TFT substrate 2 due to some abnormality, the protection circuit 222 does not generate heat as shown in FIG. For this reason, it turns out that abnormality has arisen in the application of a voltage. In this case, as shown in FIG. 8B, regardless of whether or not there is a defect in the active area 21, the heat generation point F2 as described above does not appear in the infrared image. Therefore, when the state shown in FIG. 8A can be confirmed, the inspection can be interrupted to take measures against the abnormality of the power supply system.

  As described above, by using the protection circuit 222 as the energization inspection unit, it is not necessary to newly provide a circuit or the like serving as the energization inspection unit on the TFT substrate 2. Thereby, an existing mask can be used as a mask for manufacturing the TFT substrate 2. Therefore, since it is not necessary to prepare a new mask including the new circuit as described above, it is possible to perform an energization inspection of the TFT substrate 2 (active area 21) at a reduced cost.

[Realization 3]
Subsequently, as the third embodiment of the present invention, the above-described energization inspection unit will be specifically specified and described.

  FIG. 9A is a plan view showing the configuration of the mother substrate 1 used in the method for inspecting the current of the TFT substrate 2 according to Embodiment 3 of the present invention, and FIG. 9B is an enlarged view of a part of the mother substrate 1. It is a top view shown. FIGS. 10A and 10B are diagrams showing the inspection results obtained by the energization inspection method for the TFT substrate 2 according to the third embodiment.

  In FIG. 9A, the mother substrate 1 is depicted as having two TFT substrates 2 for the sake of convenience.

  In the present embodiment, as shown in FIGS. 9A and 9B, check pads 101 and 102 provided in the non-substrate region 1a of the mother substrate 1 and the heat generation wiring 103 are used as a current inspecting unit.

  The non-substrate region 1 a is a region where the TFT substrate 2 is not formed on the mother substrate 1 and is provided as a margin for dividing the TFT substrate 2. The check pads 101 and 102 are arranged outside the dividing line (outline of the TFT substrate 2) at an interval in the non-substrate region 1a. While voltage is applied to the check pad 101, the check pad 102 is connected to ground. The heat generation wiring 103 is formed in a straight line so that both ends thereof are connected to the check pads 101 and 102, respectively. The material for forming the heat generating wiring 103 may be any conductive material that generates heat when a current flows. For example, Au (gold) or Cu (copper) is suitable.

  Here, the probe frame 3 separately includes a probe needle 32 for applying a voltage to the check pad 101 so that the voltage is also applied to the check pad 101 when a voltage is applied to the TFT substrate 2. Have. Alternatively, the mother substrate 1 may have wiring extending from the terminal portions 23 and 24 of the TFT substrate 2 to the check pad 101 in the non-substrate region 1a.

  Here, the first infrared camera 4 and the second infrared camera 5 described above also capture the non-substrate region 1a corresponding to the TFT substrate 2 to be inspected.

  In the above configuration, when the power supply system is functioning normally, when a voltage is applied to the TFT substrate 2, the voltage is also applied to the heat generation wiring 103 between the check pads 101 and 102. In this case, as shown in FIG. 10A, the heat generation wiring 103 (heat generation portion) generates heat, and therefore, in the infrared image, the heat generation wiring 103 appears linearly as a heat generation portion in the non-substrate region 1a.

  On the other hand, when the power supply system is not functioning normally, no voltage is applied to the TFT substrate 2, and thus no voltage is applied to the heat generation wiring 103. In this case, as shown in FIG. 10B, the heat generation wiring 103 does not generate heat, so that no heat generation portion appears in the non-substrate region 1a in the infrared image.

  As described above, by using the check pads 101 and 102 and the heat generation wiring 103 provided in the non-substrate region 1a as the conduction inspection unit, it is not necessary to separately provide a circuit or the like used as the conduction inspection unit on the TFT substrate 2.

  In addition, since the check pads 101 and 102 and the heat generation wiring 103 are formed in the non-substrate region 1a outside the dividing line, the non-substrate region 1a is disconnected when the TFT substrate 2 is divided from the mother substrate 1. Therefore, the check pads 101 and 102 and the heat generation wiring 103 do not affect the TFT substrate 2 after the division.

[Additional Notes]
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The defect inspection apparatus according to the present invention can be suitably used for a defect inspection apparatus that inspects defects such as wiring formed on a substrate used in a display panel such as a liquid crystal panel or a substrate such as a solar battery panel.

1 Mother substrate 1a Non-substrate region 2 TFT substrate (substrate)
3 Probe frame 4 First infrared camera (infrared camera)
5 Second infrared camera (infrared camera)
21 Active area (inspected area)
22 peripheral circuit part 23 terminal part 24 terminal part 32 probe needle 33 voltage application part (voltage application means)
212 Scan lines (wiring)
213 Signal line (wiring)
222 Protection circuit (heat generating part)
222a Switching element 222b Switching element 512 Voltage control unit 514 Voltage application determination unit (voltage application determination means)
515 Defect position specifying part (defect detection means)
100 Defect inspection apparatus 101 Check pad 102 Check pad 103 Heat generation wiring (heat generation part)
231 terminal 241 terminal

Claims (5)

An infrared camera for imaging a substrate including a region to be inspected having a plurality of wirings;
Voltage applying means for applying a voltage to the wiring of the substrate;
In the infrared image obtained by imaging with the infrared camera, the presence or absence of the application of the voltage to the inspection area is determined based on the presence or absence of heat generation of the heating part provided on the substrate and generating heat by the application of the voltage. Voltage application determination means for
When the energization to the inspection area is determined by the voltage application determination means, the defect detection means for detecting a heat generation location in the inspection area as a defect based on the infrared image ,
The defect inspecting apparatus , wherein the heat generating part is a protection circuit for protecting the wiring . The defect inspection apparatus according to claim 1 , wherein the protection circuit includes two switching elements having a diode ring structure connected between two adjacent wirings. A voltage application process for applying a voltage to the wiring of the substrate including a region to be inspected having a plurality of wirings;
A substrate imaging process for imaging the substrate using an infrared camera;
Presence / absence of application of the voltage to the region to be inspected based on presence / absence of heat generation of a heat generating part provided on the substrate and generating heat by applying voltage to the substrate in an infrared image obtained by imaging by the infrared camera Voltage application determination processing for determining
A defect detection process for detecting a heat generation location in the inspection area as a defect based on the infrared image when the energization to the inspection area is determined by the voltage application determination process ,
The defect inspecting method , wherein the heat generating part is a protection circuit for protecting the wiring . A defect inspection program for causing a computer to execute each process in the defect inspection method according to claim 3 . A computer-readable recording medium on which the defect inspection program according to claim 4 is recorded.

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