JP2012122779A - Checkup method and checkup device for display panel boards, and checkup board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a checkup method for display panel boards suitable for reducing the number of probes required and the length of time taken for checkup.SOLUTION: A checkup method for display panel boards comprises a step of arranging over and facing a display panel board 200 a checkup board 101 provided with a plurality of checkup electrodes 111 arranged in a matrix; a step of causing by driving an active element T1 a capacitance formed of a pixel electrode 202 and the checkup electrodes 111 to hold an electric charge; and a step of causing a measuring circuit 102, electrically connected to the checkup electrodes 111, to measure via the checkup board 101 the electric charge held by the capacitance.

Description

  The present invention relates to a display panel substrate inspection method, inspection apparatus, and inspection substrate including a plurality of active elements arranged in a matrix and pixel electrodes connected to each of the active elements.

  As an image display device using a current-driven light emitting element, an organic EL display using an organic electroluminescence element (hereinafter referred to as an organic EL element) is known. Since this organic EL display has the advantages of good viewing angle characteristics and low power consumption, it attracts attention as a next-generation FPD (Flat Panel Display) candidate.

  Patent Document 1 discloses a method for detecting defective pixels in a manufacturing process of an organic EL display device.

  FIG. 15 is a circuit diagram showing a configuration of one pixel of an organic EL array substrate before assembling the organic EL panel disclosed in Patent Document 1 and an inspection apparatus for inspecting the pixel. This organic EL array substrate includes a drive transistor 2, a holding capacitor 3, a switching transistor 4, a gate line 5, and a data line 6.

  The drive transistor 2 is composed of, for example, a P-channel thin film transistor (TFT), and its source is connected to the common line 7. The holding capacitor 3 is connected between the gate of the drive transistor 2 and the common line 7. The switching transistor 4 is also composed of, for example, a P-channel thin film transistor (TFT), and its source is connected to the gate of the drive transistor 2, its gate is connected to the gate line 5, and its drain is connected to the data line 6.

  The parasitic capacitor 8 is a capacitance due to overlapping of gate and drain electrodes in a bottom gate and top contact structure using, for example, amorphous silicon as a channel layer. For example, in an organic EL having a top emission structure, it is shown in FIG. An ITO (indium tin oxide) film serving as an anode is formed on the organic EL array substrate, and the ITO film is structurally overlapped with the gate of the drive transistor 2.

  An inspection device 9 is connected to inspect the organic EL array substrate. The inspection device 9 includes an integrator 10, a switching element 16, a control circuit 17, a writing circuit 18, and a detection unit 19.

  The integrator 10 includes a differential amplifier 12 and an integration capacitor 14. The data line 6 of the organic EL array substrate is connected to the inverting input terminal of the differential amplifier 12 via the switching element 16. The control circuit 17 controls the potential GATE of the gate line 5 by a method described later. The write circuit 18 applies a predetermined potential to the data line 6 by a method described later. The detector 19 detects a defect on the EL array substrate based on the output of the integrator 10.

  In actual inspection, the integrator 10 is connected to each data line 6, the control circuit 17 is connected to all the gate lines 5, and the writing circuit 18 is connected to all the data lines 6.

  This inspection method includes a mode in which charges are written in the holding capacitor 3 and the parasitic capacitor 8, a mode in which the written charges are read, and a mode in which a defect is detected based on the read charges.

  Further, Patent Document 2 discloses a method of applying a charge to a TFT / LCD cell capacitor and measuring the charge held in the capacitor after a short time has elapsed.

Japanese Patent Laying-Open No. 2003-295790 (FIG. 1) JP-A-3-200121

  However, according to the conventional inspection methods disclosed in Patent Document 1 and Patent Document 2, a problem that a large number of probes, which are fine needles for connecting the substrate to be inspected, are required, and the inspection is speeded up. There is a problem that it cannot be done.

  In other words, in the prior art, data is written to each pixel through the data line of the substrate to be inspected, and data is read out through the data line of the substrate to be inspected, so that many fine probes are connected to the substrate to be inspected. This increases the cost of the inspection apparatus and increases the number of steps for connecting the probe to the substrate to be inspected.

  In addition, since data writing and data reading are performed through the same data line of the substrate to be inspected, data writing and data reading cannot be performed simultaneously or in parallel, and it is difficult to shorten the inspection time. is there.

  In particular, as the resolution is increased and the screen is increased, a large amount of probes are required, and it is difficult to apply the conventional method.

  In view of the above problems, an object of the present invention is to provide a display panel substrate inspection method, inspection apparatus, and inspection substrate that are suitable for reducing the number of probes connected to a substrate to be inspected and shortening the inspection time. .

  In order to solve the above problems, a display panel substrate inspection method according to an embodiment of the present invention includes a plurality of active elements arranged in a matrix and a pixel electrode connected to each of the active elements. An inspection substrate inspection method comprising: disposing an inspection substrate having a plurality of inspection electrodes arranged in a matrix on the display panel substrate opposite to each other; and driving the active element The charge formed in the capacitor formed by the pixel electrode and the inspection electrode, and the charge held in the capacitor by the measurement circuit electrically connected to the inspection electrode. Measuring through the substrate.

  According to this configuration, since the charge measurement (reading) is performed from the inspection substrate instead of the display panel substrate, it is not necessary to connect a probe for reading out charges to the display panel substrate, and the corresponding probe The number can be reduced. Further, since reading is performed from the substrate to be inspected, the number of needles connected to the inspection substrate can be reduced. There are few needles because the electrodes are not in contact. The step of holding the charge is mainly performed from the display panel substrate, and the step of measuring is performed from the inspection substrate. Therefore, the step of holding and the step of measuring can be performed separately on the two substrates, and the inspection time is reduced. It is possible to shorten the inspection time and speed up the inspection.

  According to the method for inspecting a display panel substrate in one embodiment of the present invention, the number of probes connected to the display panel substrate can be reduced. In addition, it is possible to shorten the inspection time and speed up the inspection.

It is a figure which shows the structure of a test | inspection apparatus, and a to-be-inspected board | substrate. It is a block diagram which shows the structural example of a to-be-inspected board | substrate. It is a block diagram which shows the structural example of a pixel circuit (display pixel). It is a general-view figure which shows the structure of the board | substrate for a test | inspection. It is a block diagram which shows the structure of the board | substrate for a test | inspection. It is a block diagram which shows the structure of a pixel circuit (inspection pixel). It is a flowchart which shows the manufacturing process of a display panel. It is a flowchart which shows the detail of an inspection process. It is a flowchart which shows the detail of a repair process. It is explanatory drawing of the capacity | capacitance formed with a pixel electrode and a test electrode. It is a time chart of an inspection process. It is operation | movement explanatory drawing in a test process (t1-t21). It is operation | movement explanatory drawing in a test process (t21-t22). It is operation | movement explanatory drawing in a test process (t22-t3). It is operation | movement explanatory drawing in a test process (t3-t4). It is operation | movement explanatory drawing in a test process (t4-t51). It is operation | movement explanatory drawing in a test process (t51-t71). It is operation | movement explanatory drawing in a test process (t71-t72). FIG. 5 is a diagram illustrating a configuration of a pixel circuit (display pixel) on a substrate to be inspected and a pixel circuit (inspection pixel) on a test substrate in Embodiment 2. It is explanatory drawing of the capacity | capacitance formed with a pixel electrode and a test electrode. It is a time chart of an inspection process. A specific example of a pixel circuit of a substrate to be inspected is shown. A specific example of a pixel circuit of a substrate to be inspected is shown. 10 is a diagram in which a plurality of inspection electrodes are opposed to one pixel electrode in Embodiment 3. FIG. It is explanatory drawing of the capacity | capacitance formed when several inspection electrode opposes one pixel electrode. It is a flowchart which shows the detail of an inspection process. It is a circuit diagram which shows the structure of the test | inspection circuit in a prior art.

  A display panel substrate inspection method according to an embodiment of the present invention is a display panel substrate inspection method including a plurality of active elements arranged in a matrix and pixel electrodes connected to each of the active elements. A step of disposing an inspection substrate having a plurality of inspection electrodes arranged in a matrix on the display panel substrate, and driving the active element to thereby form the pixel electrode and the A step of holding electric charge in a capacitor formed by the inspection electrode, and a step of measuring the electric charge held in the capacitor through the inspection substrate by a measurement circuit electrically connected to the inspection electrode Including.

  According to this configuration, since the charge measurement (reading) is performed from the inspection substrate instead of the display panel substrate, it is not necessary to connect a probe for reading out charges to the display panel substrate, and the corresponding probe The number can be reduced. Further, since reading is performed from the substrate to be inspected, the number of needles connected to the inspection substrate can be reduced. The step of holding the charge is mainly performed from the display panel substrate, and the step of measuring is performed from the inspection substrate. Therefore, the step of holding and the step of measuring can be performed separately on the two substrates, and the inspection time is reduced. It is possible to shorten the inspection time and speed up the inspection.

  Here, the area of the inspection electrode is smaller than the area of the pixel electrode, and in the disposing step, a plurality of inspection electrodes can be disposed to face one pixel electrode.

  According to this configuration, it is possible to inspect a plurality of types of display panels having pixel electrodes of different sizes. That is, the inspection substrate can be provided with versatility without depending on the size of the pixel electrode.

  Here, the method for inspecting the display panel substrate further includes the step of converting the amount of charges of a plurality of inspection electrodes facing one pixel electrode into a charge amount corresponding to the capacitance of the pixel electrode by weighted addition. Can be included.

  According to this configuration, when one pixel electrode and a plurality of inspection electrodes overlap, the charge amount corresponding to the pixel electrode can be calculated using the overlapping area of each inspection electrode as a weighting coefficient. .

  Here, the inspection substrate includes a plurality of switching thin film transistors corresponding to the plurality of inspection electrodes, a scanning line corresponding to one of a row and a column of the plurality of inspection electrodes arranged in a matrix, And a detection line corresponding to the other of the row and column of the plurality of inspection electrodes arranged in a matrix, and in the step of measuring the charge held in the capacitor, the switching thin film transistor includes the scanning line. By supplying a scanning signal through the terminal and connecting the inspection electrode to the measuring circuit through the detection line, the charge held in the capacitor can be measured.

  Here, the display panel substrate further includes a scanning line corresponding to one of a row and a column of the plurality of pixel electrodes arranged in a matrix, and a row of the plurality of pixel electrodes arranged in a matrix. A data line corresponding to the other of the columns; and a plurality of power lines for supplying power to the plurality of active elements, wherein the active element includes a first thin film transistor and a second thin film transistor, In the step of holding the pixel, a scanning signal is supplied to the first thin film transistor via the scanning line, a predetermined voltage is applied to the gate electrode of the second thin film transistor from the data line, and the pixel The electrode can be configured to retain electric charge by supplying current from the power supply line through the second thin film transistor.

  Here, the display panel substrate may be a substrate for an organic electroluminescence display device.

  In addition, an inspection apparatus for a display panel substrate according to an embodiment of the present invention is used for inspecting a display panel substrate including a plurality of active elements arranged in a matrix and pixel electrodes connected to the active elements. The inspection apparatus includes an inspection substrate and a control unit, and the inspection substrate includes a plurality of switching thin film transistors corresponding to the plurality of inspection electrodes, and the plurality of thin film transistors arranged in a matrix. A scanning line corresponding to one of the rows and columns of the inspection electrodes and a detection line corresponding to the other of the plurality of rows and columns of the plurality of inspection electrodes arranged in a matrix, and the control unit includes: By driving the active element in a state where an inspection substrate having a plurality of inspection electrodes arranged in a matrix is opposed to the display panel substrate. A charge formed in the capacitor formed by the pixel electrode and the inspection electrode is held, and the charge held in the capacitor is transferred to the measurement circuit electrically connected to the inspection electrode via the inspection substrate. To measure.

  Further, the inspection substrate for the display panel substrate in one embodiment of the present invention is an inspection of a display panel substrate including a plurality of active elements arranged in a matrix and pixel electrodes connected to each of the active elements. A plurality of switching thin film transistors corresponding to the plurality of inspection electrodes, and a scanning line corresponding to one of a row and a column of the plurality of inspection electrodes arranged in a matrix, A plurality of inspection electrodes arranged in a matrix on the display panel substrate, the detection line corresponding to the other of the row and column of the plurality of inspection electrodes arranged in a matrix When the active element is driven by arranging the substrate for use facing each other, electric charges are held in a capacitor formed by the pixel electrode and the inspection electrode, and the inspection is performed. By electrically connected to the measuring circuit to use electrodes, the charge held in the said capacitance is measured through the testing board.

  Here, the area of the inspection electrode is smaller than the area of the pixel electrode, and a plurality of inspection electrodes may be arranged to face one pixel electrode.

(Embodiment 1)
FIG. 1 is a diagram showing a configuration of an inspection apparatus and a substrate to be inspected according to Embodiment 1 of the present invention.

  The inspection apparatus 100 includes an inspection substrate 101, a measurement circuit 102, a control unit 103, a monitor 104, an operation unit 105, and a drive circuit 106. The inspection apparatus 100 inspects the substrate to be inspected (display panel substrate) 200 in a state in which the substrate to be inspected (display panel substrate) 200 and the substrate for inspection 101 are stacked so that the electrodes face each other.

  The inspected substrate (display panel substrate) 200 is a part of a display panel device before completion, and after completion, becomes a part of an organic EL display device, an inorganic EL display device, a liquid crystal display device, and the like.

  FIG. 2A is a block diagram illustrating a configuration example of the substrate to be inspected 200.

  The inspected substrate 200 includes a plurality of pixel circuits 201 arranged in a matrix of m rows and n columns, scanning lines SCAN (i) corresponding to the rows of the pixel circuits (display pixels) 201, and pixel circuits (display pixels). Data line DATA (j) corresponding to 201 columns.

  FIG. 2B is a block diagram illustrating a configuration example of the pixel circuit (display pixel) 201. As shown in the figure, the pixel circuit (display pixel) 201 includes an active element T1, a pixel electrode 202, and a holding circuit 203.

  The active element T1 is a thin film transistor (TFT), the scanning line SCAN (i) is connected to the gate, the data line DATA (i) is connected to one of the source and the drain, and the other of the source and the drain is connected to the other. Connected to the holding circuit 203.

  The pixel electrode 202 is one of two electrodes that seal the organic EL material or the liquid crystal, and the pixel electrode 202 is exposed at the inspection stage. In this state, the active element T1 and the pixel electrode 202 can detect defects in the matrix-shaped active element and the holding circuit.

  FIG. 3A is an overview diagram showing the configuration of the inspection substrate 101. The inspection substrate 101 is driven and controlled by the control unit 103 via the measurement circuit 102.

  FIG. 3B is a block diagram illustrating a configuration example of the inspection substrate 101. FIG. 3C is a block diagram illustrating a configuration of a pixel circuit (inspection pixel).

  3B and 3C, the inspection substrate 101 includes a plurality of switching thin film transistors T2 corresponding to the plurality of inspection electrodes 111 and a plurality of inspection electrodes 111 arranged in a matrix of M rows and N columns. The scanning line SCAN_RW (I) corresponding to one of the row and the column and the detection line DATA_RW (J) corresponding to the other of the row and the column of the plurality of inspection electrodes 111 arranged in a matrix are included.

  Here, an outline of the entire manufacturing process of the display panel device will be described.

  FIG. 4 is a flowchart showing the manufacturing process of the display panel device. As shown in the figure, first, a substrate to be inspected 200, which is in a state before completion, is manufactured as a display panel device (S100), a defective portion is detected by an inspection process by the inspection apparatus 100 (S200), and a repair process is performed. Repairable defects are repaired (S300), and the remaining manufacturing process is performed to complete the display panel device (S400). Thus, the inspection process is performed on the substrate to be inspected (display panel substrate) 200 in a state before completion as a display panel device.

  Next, the outline of the inspection process S200, that is, the inspection method of the substrate 200 to be inspected will be described.

  The inspection step S200 includes a plurality of active elements T1 arranged in a matrix, a pixel electrode 202 connected to each of the active elements T1, and a holding circuit 203 that controls the voltage of the pixel electrode. Inspection method.

  In the inspection step S200, a step of disposing an inspection substrate 101 including a plurality of inspection electrodes 111 arranged in a matrix on the display panel substrate 200 and driving an active element (T1). Thus, the step of holding the charge in the capacitance formed by the pixel electrode 202 and the inspection electrode 111 (S206 to S209) and the measurement circuit 102 electrically connected to the inspection electrode 111 held the capacitance. Measuring the charge through the inspection substrate 101 (S210).

  According to this, since the charge measurement (reading) is performed from the inspection substrate, it is not necessary to connect a probe for reading the charge to the display panel substrate, and the number of probes can be reduced accordingly. In addition, since the data is read from the substrate to be inspected, there are few needles. Since the electrodes are not in contact with each other, there is no physical damage to the electrodes on the substrate to be inspected. The step of holding the charge is mainly performed from the display panel substrate, and the step of measuring is performed from the inspection substrate. Therefore, the step of holding and the step of measuring can be performed separately on the two substrates, and the inspection time is reduced. It is possible to shorten the inspection time and speed up the inspection.

  Further, the inspection process will be described in detail with reference to FIGS. 5, 7, 8, and 9 </ b> A to 9 </ b> G.

  FIG. 5 is a flowchart showing details of the inspection process, that is, the inspection method of the substrate 200 to be inspected.

  First, the substrate to be inspected (display panel substrate) 200 is fixed (S201), the inspection substrate 101 is moved to the top of the substrate to be inspected 200 (S202), and the position of the inspection substrate 101 with respect to the substrate to be inspected 200 is adjusted. Then, the gap between the inspection substrate 101 and the substrate to be inspected 200 is adjusted (S204). At this time, the gap may be adjusted by the inspection apparatus 100 or may be adjusted by a spacer. The spacer may be provided on the inspection substrate side or may be provided on the inspection substrate. The gap is desirably in the micron order.

  After the gap adjustment, a capacitor C is formed by the pixel electrode 202 and the inspection electrode 111 as shown in FIG.

  Next, a needle for transmitting an operation signal for operating the inspected substrate 200 is brought into contact (S205), and the inspected substrate 200 and the drive circuit 106 are connected. It is desirable that the inspection substrate 101 is connected to the measurement circuit 102 in advance as shown in FIG. 3A.

  Further, as shown in FIG. 9A, the potentials of all the inspection electrodes of the inspection substrate 101 are fixed to a single potential Vo (S206, t1 to t21 in FIG. 8).

  Further, as shown in FIG. 9B, the inspection potential V1 is written to all the pixels of the inspected substrate 200 (S207, t21 to t22). The method of writing the test potential V1 at this time may be all the pixels at once, may be divided evenly or oddly in the row direction, may be divided evenly or oddly in the column direction, or a combination thereof.

  Furthermore, as shown in FIG. 9C, after writing to all the pixels of the inspected substrate 200 is completed (t22 to t3), as shown in FIG. 9D, all the inspection electrodes 111 of the inspection substrate 101 are brought into a floating state ( S208, t3 to t4). This period of the floating state is a period for amplifying a change in charge due to a defect. Assuming that the potential of the pixel electrode 202 after the elapse of this period is (V1−ΔV), ΔV is within the allowable range when there is no defect, and exceeds the allowable range when there is a defect.

  Further, as shown in FIG. 9E, the potentials of all the pixel electrodes of the substrate to be inspected 200 are fixed to a single potential (S209, t4 to t51).

  The following steps S210 and S211 (FIGS. 9F and 9G) are processes in units of one scanning row.

  Further, as shown in FIG. 9F, the electric charge stored in the inspection electrode of the inspection substrate is read (S210, t51 to t71).

  Further, as shown in FIG. 9G, when the read charge is out of the allowable range (absolute range or a value having a large difference from the surroundings), the position information is held in the memory together with the substrate information ( S211, t71 to t72). For example, when 10V (= V1) is written and 9.5V (= V1−ΔV) or more is measured, the allowable range is set. At this time, not only the charge outside the allowable range but also information on the charge in the normal range may be stored in the memory together with the position information. The above memory may be a memory in the measurement circuit 102 or a memory in the control unit 103.

  Further, if there remains an unmeasured scan line, the process proceeds to S210, and if not, the inspection process is terminated.

  Next, the repair process will be described.

  FIG. 6 is a flowchart showing details of the repair process.

  First, the position information is read from the memory (S301), the type of defect is determined or predicted from the position information, and it is determined whether the defect can be repaired or cannot be repaired (S302). If it is determined that the defect can be repaired, it is repaired (S303), and the inspected substrate 200 after the repair is passed again to the inspection process. On the other hand, if it is determined that repair is not possible, the board 200 to be inspected is discarded or reused (S304).

  As described above, according to the method for inspecting the display panel substrate 200 in the present embodiment, the charge is measured (read) from the inspection substrate, not from the display panel substrate. It is not necessary to connect a probe for reading out charges, and reading out from the inspected substrate can reduce the number of probes. There are few needles because the electrodes are not in contact. The step of holding the charge is mainly performed from the display panel substrate, and the step of measuring is performed from the inspection substrate. Therefore, the step of holding and the step of measuring can be performed separately on the two substrates, and the inspection time is reduced. It is possible to shorten the inspection time and speed up the inspection.

(Embodiment 2)
FIG. 10 is a diagram illustrating a configuration of the pixel circuit (inspection pixel) 110 of the inspection substrate in the second embodiment.

  In this figure, compared to FIG. 3C of the first embodiment, the thin film transistor T3 is added to have two thin film transistors per pixel circuit, and the number of scanning lines is increased from one to two for each row. The difference is that the number of data lines is increased from one to two for each column. Other than this, the second embodiment is the same as the first embodiment, so the description of the same points will be omitted and the following description will focus on the different points.

  In FIG. 3C, the function of writing (holding) the voltage to the inspection electrode 111 and the function of reading (measuring) the voltage from the inspection electrode 111 can function alternatively, but in FIG. Since there are two scanning lines and data lines for each pixel, the function of writing (holding) the voltage to the inspection electrode 111 and the function of reading (measuring) the voltage from the inspection electrode 111 can be controlled independently. It has become.

  FIG. 11A is an explanatory diagram of a capacitor formed by the pixel electrode and the inspection electrode. Compared with FIG. 7, the writing operation (holding voltage) to the inspection electrode 111 is controlled by the thin film transistor T <b> 2, the scanning line SCAN_W, and the data line DATA_W, and is read from the inspection electrode 111 (voltage is measured). The operation is configured to be controlled by the thin film transistor T3, the scanning line SCAN_R, and the data line DATA_R. That is, writing and reading can be controlled independently.

  FIG. 11B is a time chart of the inspection process. 8 shows almost the same timing as FIG. 8, but as can be seen from the configuration of FIG. 11A, the data line DATA_R for reading (voltage measurement) is not easily affected by the data line DATA_W for writing. The accuracy of measurement can be improved.

  In each embodiment, the pixel circuit (display pixel) 201 illustrated in FIG. 2B may have the configuration illustrated in FIG. 12A or 12B.

  FIG. 12A shows a specific example of a pixel circuit when the substrate to be inspected is used in an LCD display device. The holding circuit 203 in the figure is configured by a capacitive element Cs.

  FIG. 12B shows a specific example of a pixel circuit when the substrate to be inspected is used in an organic EL display device. The holding circuit 203 in the figure is composed of a capacitive element Cs and a thin film transistor TD.

(Embodiment 3)
In the first embodiment, the example in which the pixel electrode 202 and the inspection electrode 111 face each other on a one-to-one basis has been described. However, in this embodiment, the pixel electrode 202 and the inspection electrode 111 face each other on a one-to-many basis. An example will be described. That is, an example in which the area of the inspection electrode 111 is smaller than the area of the pixel electrode 202 will be described.

  FIG. 13A is an explanatory diagram illustrating an example in which a plurality of inspection electrodes face one pixel electrode in the third embodiment. In the figure, four inspection electrodes 111a to 111d partially overlap each other and face one pixel electrode 202.

  FIG. 13B is an explanatory diagram of a capacitor formed when a plurality of inspection electrodes face one pixel electrode. The capacitances of the four inspection electrodes 111a to 111d with respect to one pixel electrode 202 are Ca to Cd. The four capacitors are connected in parallel.

  FIG. 14 is a flowchart showing details of the inspection process. The figure differs from FIG. 5 in that step S221 is added between step S210 and step S211. Explanation of the same points will be omitted, focusing on different points.

  In step S221, the charges of a plurality of inspection electrodes opposed to one pixel electrode are weighted and added, thereby converting the charge amount corresponding to the capacitance of the pixel electrode.

  This conversion may be, for example, equation (1).

Qp = k * (Qa + Qb + Qc + Qd) + (lx * xo + ly * yo-lx * ly) / k (1)
k = d / ε (2)

 Here, Qp is the amount of charge obtained when the inspection electrodes having the same area as the pixel electrode 202 overlap. Qa is a measurement result (charge amount) from the inspection electrode 111a. Qb to Qd are the same except that the inspection electrodes are different.

  k is the gap d between the pixel electrode and the inspection electrode divided by the dielectric constant of the space between the pixel electrode and the inspection electrode.

  lx and ly are spaces between test electrodes, and xo and yo are pixel electrode sizes.

  According to the present embodiment, it is possible to inspect a plurality of types of display panels having different pixel electrode sizes with a single inspection substrate. That is, the inspection substrate can be provided with versatility without depending on the size of the pixel electrode.

  Note that although an example in which four inspection electrodes partially overlap one pixel electrode 202 has been described in Equation (1), this is a case where two or more inspection electrodes partially overlap one pixel electrode. Similarly, the number of terms can be converted in correspondence.

  The display panel inspection method, inspection apparatus, and inspection substrate according to the present invention have been described above based on the embodiments, but the present invention is not limited to the above-described embodiments. Other embodiments realized by combining arbitrary components in the embodiments, and modifications obtained by subjecting the embodiments to various modifications conceivable by those skilled in the art without departing from the gist of the present invention. It is included in the present invention.

  The method for producing an organic EL display device of the present invention is useful in technical fields such as flat-screen televisions and personal computer displays that require a large screen and high resolution.

DESCRIPTION OF SYMBOLS 100 Inspection apparatus 101 Inspection board 102 Measurement circuit 103 Control part 104 Monitor 105 Operation part 106 Drive circuit 110 Pixel circuit (inspection pixel)
111 Electrode for inspection 200 Substrate to be inspected (display panel substrate)
201 Pixel circuit (display pixel)
202 Pixel electrode 203 Holding circuit T1-T3, TD Thin film transistor

Claims (9)

A method for inspecting a display panel substrate, comprising a plurality of active elements arranged in a matrix and pixel electrodes connected to each of the active elements,
Disposing an inspection substrate provided with a plurality of inspection electrodes arranged in a matrix on the display panel substrate,
Holding the charge in a capacitor formed by the pixel electrode and the inspection electrode by driving the active element;
Measuring a charge held in the capacitor through the inspection substrate by a measurement circuit electrically connected to the inspection electrode. The area of the inspection electrode is smaller than the area of the pixel electrode,
2. The display panel substrate inspection method according to claim 1, wherein, in the arranging step, a plurality of inspection electrodes are arranged to face one pixel electrode. 3. The display panel substrate inspection method further includes:
The display panel substrate inspection method according to claim 1, further comprising the step of converting the amount of charge of a plurality of inspection electrodes facing one pixel electrode into a charge amount corresponding to the capacitance of the pixel electrode by weighted addition. The inspection substrate is:
A plurality of switching thin film transistors corresponding to the plurality of inspection electrodes;
A scanning line corresponding to one of a row and a column of the plurality of inspection electrodes arranged in a matrix;
A detection line corresponding to the other of the row and column of the plurality of inspection electrodes arranged in a matrix,
In the step of measuring the charge held in the capacitor, a scanning signal is supplied to the switching thin film transistor through the scanning line, and the inspection electrode is connected to the measuring circuit through the detection line. The method for inspecting a display panel substrate according to claim 1, wherein the electric charge held in the capacitor is measured. The display panel substrate further includes a scanning line corresponding to one of a row and a column of the plurality of pixel electrodes arranged in a matrix,
A data line corresponding to the other of the row and column of the plurality of pixel electrodes arranged in a matrix;
A plurality of power lines for supplying power to the plurality of active elements,
The active element includes a first thin film transistor and a second thin film transistor,
In the step of holding the charge in the capacitor, a scanning signal is supplied to the first thin film transistor via the scanning line, and a predetermined voltage is applied to the gate electrode of the second thin film transistor from the data line. The pixel electrode is charged with electric current when supplied from the power supply line via the second thin film transistor.
A method for inspecting a display panel substrate according to claim 1. The display panel substrate is a substrate for an organic electroluminescence display device,
The method for inspecting a display panel substrate according to claim 5. An inspection apparatus used for inspecting a substrate for a display panel including a plurality of active elements arranged in a matrix and pixel electrodes connected to each of the active elements,
The inspection apparatus includes an inspection substrate and a control unit,
The inspection board is
A plurality of switching thin film transistors corresponding to the plurality of inspection electrodes;
A scanning line corresponding to one of a row and a column of the plurality of inspection electrodes arranged in a matrix;
A detection line corresponding to the other of the row and column of the plurality of inspection electrodes arranged in a matrix,
The controller is
By driving the active element in a state where an inspection substrate having a plurality of inspection electrodes arranged in a matrix is opposed to the display panel substrate, the pixel electrode and the inspection are driven. Hold the charge in the capacitor formed by the electrode for
An inspection apparatus that causes a measurement circuit electrically connected to the inspection electrode to measure the charge held in the capacitor via the inspection substrate. An inspection substrate used for inspection of a display panel substrate including a plurality of active elements arranged in a matrix and pixel electrodes connected to each of the active elements,
A plurality of switching thin film transistors corresponding to the plurality of inspection electrodes;
A scanning line corresponding to one of a row and a column of the plurality of inspection electrodes arranged in a matrix;
A detection line corresponding to the other of the row and column of the plurality of inspection electrodes arranged in a matrix,
On the display panel substrate, an inspection substrate having a plurality of inspection electrodes arranged in a matrix is arranged to face each other.
By driving the active element, a charge is held in a capacitor formed by the pixel electrode and the inspection electrode,
A test substrate in which a charge held in the capacitor is measured via the test substrate by a measurement circuit electrically connected to the test electrode. The area of the inspection electrode is smaller than the area of the pixel electrode,
The inspection substrate according to claim 8, wherein a plurality of inspection electrodes are arranged to face one of the pixel electrodes.

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