JP4255645B2 - Inspection method and inspection apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an element substrate inspection apparatus included in a semiconductor device and an inspection method using the same. More specifically, the present invention relates to a non-contact type inspection apparatus and an inspection method using the same.
[0002]
[Prior art]
In recent years, a technique for forming a thin film transistor (TFT) using a semiconductor film (having a thickness of about several to several hundred nm) formed on a substrate having an insulating surface has attracted attention. This is because the demand for an active matrix semiconductor display device which is one of the semiconductor devices has increased. The active matrix semiconductor display device typically includes a liquid crystal display, an OLED (Organic Light Emitting Device) display, and a DMD (Digital Micromirror Device).
[0003]
A TFT (crystalline TFT) using a semiconductor film having a crystal structure as an active layer has high mobility. Therefore, an active matrix semiconductor that displays high-definition images by integrating functional circuits on the same substrate. A display device can be realized.
[0004]
Incidentally, an active matrix semiconductor display device is completed through various manufacturing processes. For example, in the case of an active matrix liquid crystal display, a pattern forming process for forming a semiconductor film and forming a pattern, a color filter forming process for realizing colorization, an element substrate having an element including a semiconductor, and a counter electrode A cell assembly process for forming a liquid crystal panel by enclosing a liquid crystal between a counter substrate and a liquid crystal panel assembled in the cell assembly process, and driving parts and a backlight for operating the liquid crystal panel are attached, It mainly has a module assembly process to be completed as a liquid crystal display.
[0005]
Although there are some differences depending on the type of liquid crystal display, each of the above steps includes an inspection step. If a defective product can be identified at an early stage of the process before it is completed as a product, the subsequent process can be omitted for the panel. Therefore, the inspection process is a very effective means from the viewpoint of cost reduction.
[0006]
[Problems to be solved by the invention]
One inspection process included in the pattern formation process is a defect inspection after pattern formation.
[0007]
Defect inspection after pattern formation refers to a location where a malfunction occurs due to variation in the width of a semiconductor film, insulating film or wiring pattern (hereinafter simply referred to as a pattern), dust, or film formation failure after pattern formation. Thus, it is an inspection for detecting a location where the wiring is disconnected or short-circuited or for confirming whether a circuit or a circuit element to be inspected normally operates.
[0008]
Such defect inspection is mainly divided into an optical inspection method and a probe inspection method.
[0009]
The optical inspection method is an inspection method in which a pattern formed on a substrate is read by a CCD or the like and compared with a reference pattern to identify defects. The probe inspection method is an inspection method in which a minute pin (probe) is set up on a terminal on the substrate side, and a defect is identified by the magnitude of current or voltage between the probes. In general, the former is called a non-contact type inspection method, and the latter is called a stylus type inspection method.
[0010]
Any of the above methods can be used to detect defects in the element substrate. However, each inspection method has its disadvantages.
[0011]
In the optical inspection method, when the inspection is performed after the formation of the patterns of many layers is completed, it is difficult to identify the pattern formed in the lower layer, so that it is difficult to detect the defective portion. However, if the inspection is performed every time the pattern is formed, the inspection process itself becomes complicated, and the time required for the entire manufacturing process becomes longer. In the probe inspection method, since the probe is directly set on the wiring, the wiring may be damaged and fine dust may be generated. The dust generated in the inspection process is not preferable because it causes a decrease in the yield of the subsequent process.
[0012]
In view of the above problems, an object of the present invention is to establish a simpler inspection method that does not require a probe to be placed on the wiring, and to provide an inspection apparatus that uses the inspection method.
[0013]
[Means for Solving the Problems]
The present inventor has thought that even if a probe is not set up, an electromotive force is generated in the wiring of the element substrate by electromagnetic induction, thereby allowing a current to flow through the wiring.
[0014]
Specifically, an inspection substrate (inspection substrate) for inspecting the element substrate is separately prepared. The inspection substrate has a primary coil, and the element substrate to be inspected has a secondary coil.
[0015]
Note that both the primary coil and the secondary coil are formed by patterning a conductive film formed on a substrate. A coil provided with a conventional magnetic body is also possible. However, in the present invention, the primary coil and the secondary coil are not coils provided with a magnetic body at the center to form a magnetic path, and no magnetic body is provided at the center. A coil was used.
[0016]
Then, the primary coil included in the inspection substrate and the secondary coil included in the element substrate are overlapped with a certain interval, and an AC voltage is applied between the two terminals included in the primary coil, whereby the secondary coil is applied. An electromotive force is generated between two terminals of the coil. It should be noted that the smaller the interval, the better. The primary coil and the secondary coil forming unit should be as close as possible to control the interval.
[0017]
Then, an AC voltage, which is an electromotive force generated in the secondary coil, is rectified in the element substrate and then smoothed appropriately, whereby a DC voltage for driving a circuit or a circuit element included in the element substrate (hereinafter referred to as a DC voltage) , Called power supply voltage). Further, a signal for driving a circuit or a circuit element included in the element substrate (hereinafter referred to as an AC voltage) that is an electromotive force generated in the secondary coil is appropriately shaped by a waveform shaping circuit or the like. , Called a drive signal).
[0018]
Then, this drive signal or power supply voltage is input to the wiring of the element substrate.
[0019]
A circuit or a circuit element formed on the substrate is driven by a drive signal or a power supply voltage input to the lead wiring. When a circuit or a circuit element is driven, a weak electromagnetic wave or electric field is generated in the circuit or the circuit element. By monitoring information contained in the weak electromagnetic wave or electric field, it is possible to detect a part that is not operating normally from a large number of circuits or circuit elements.
[0020]
Note that information of an electromagnetic wave or an electric field can be collected in various dimensions such as frequency, phase, intensity, and time. In the present invention, any information of electromagnetic waves or electric fields is used as long as it is possible to detect a part that is not operating normally from a large number of circuits or circuit elements. It is possible.
[0021]
A known method can be used for monitoring weak electromagnetic waves or electric fields generated in circuits or circuit elements.
[0022]
According to the present invention, since the above configuration can detect a defective portion without directly setting a probe on the wiring, it is possible to prevent the yield of a subsequent process from being reduced due to fine dust generated by setting the probe. Can do. In addition, unlike the optical inspection method, the quality of all pattern forming steps can be determined in one inspection step, so that the inspection step is further simplified.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1A shows a top view of an inspection substrate for performing the inspection of the present invention. FIG. 1B shows a top view of an element substrate to be inspected by the inspection method. Note that in this embodiment mode, the inspection method of the present invention is described using an element substrate included in a liquid crystal display as an example. However, the inspection method of the present invention is not limited to a liquid crystal display and uses a semiconductor. Any semiconductor device formed as described above can be used.
[0024]
The inspection board shown in FIG. 1A is provided with a primary coil forming portion 101, an external input buffer 102, and a connector connection portion 103 on a substrate 100. In the present specification, the inspection substrate includes the substrate 100 and all circuits or circuit elements formed on the substrate 100.
[0025]
The element substrate illustrated in FIG. 1B is provided over a substrate 110 with a signal line driver circuit 111, a scan line driver circuit 112, a pixel portion 113, a lead-out wiring 114, a connector connection portion 115, a waveform shaping circuit, or a rectifier circuit 116. A secondary coil forming portion 117 and a coil wiring 118 are provided. Note that in this specification, the element substrate includes the substrate 110 and all circuits or circuit elements formed on the substrate 110. Note that the lead wiring 114 is a wiring for supplying a drive signal and a power supply voltage to the pixel portion and the driver circuit included in the element substrate.
[0026]
FPC or TAB or the like is connected to the connector connecting portion 115 in a step after the inspection step. The element substrate is cut along the dotted line AA ′ so that the coil wiring 118 is physically and electrically separated after the inspection process is completed.
[0027]
Next, the operation of the element substrate and the inspection substrate in the inspection process will be described. In order to make it easy to understand the signal flow in the inspection process, the configuration of the element substrate and the inspection substrate shown in FIG. 1 is shown in a block diagram in FIG. 2, and will be described with reference to FIGS.
[0028]
In the inspection board 203, an inspection AC signal is input from the signal source 201 or the AC power source 202 to the external input buffer 102 via the connector connected to the connector connection unit 103. The AC signal for inspection is buffered and amplified in the external input buffer 102 and input to the primary coil forming unit 101.
[0029]
In FIGS. 1A and 2, the input AC signal is buffered and amplified in the external input buffer 102 and then input to the primary coil forming unit 101. However, the present invention is limited to this configuration. Not. A direct AC signal may be directly input to the primary coil forming unit 101 without providing the external input buffer 102.
[0030]
In the primary coil forming unit 101, a plurality of primary coils are formed. An AC signal is input to each primary coil.
[0031]
On the other hand, the secondary coil forming portion 117 included in the element substrate 204 is formed with a plurality of secondary coils corresponding to the plurality of primary coils included in the primary coil forming portion 101. When an AC signal is input to the primary coil, an AC voltage that is an electromotive force is generated between two terminals of each secondary coil due to electromagnetic induction.
[0032]
The AC voltage generated in the secondary coil is supplied to the waveform shaping circuit 116a or the rectifier circuit 116b. The waveform shaping circuit 116a or the rectifier circuit 116b shapes or rectifies the AC voltage to generate a drive signal or a power supply voltage.
[0033]
The generated drive signal or power supply voltage is input to the lead wiring 114 via the coil wiring 118. The input drive signal, power supply voltage, or the like is supplied to the signal line driver circuit 111, the scan line driver circuit 112, and the pixel portion 113 through the lead wiring 114.
[0034]
Note that a plurality of pixels are formed in the pixel portion 113, and a pixel electrode is formed in each pixel. Note that the number of signal line driver circuits and scan line driver circuits is not limited to the numbers illustrated in FIGS.
[0035]
When a drive signal, a power supply voltage, or the like is input to the signal line driver circuit 111, the scan line driver circuit 112, and the pixel portion 113, each circuit or circuit element included in the signal line driver circuit 111, the scan line driver circuit 112, and the pixel portion 113 In this case, an electromagnetic wave or an electric field is generated.
[0036]
The strength of the electric field and electromagnetic wave generated in a circuit or circuit element having a defect is significantly different from the strength of the electric field and electromagnetic wave generated in a normal circuit or circuit element. Therefore, by monitoring the intensity of the electromagnetic wave and electric field generated in each circuit or circuit element, it is possible to locate the defect. In FIG. 2, the inspection unit 205 measures the intensity of the electric field or electromagnetic wave to detect a defective portion.
[0037]
In addition, the output of all the circuits to be inspected is input to a circuit dedicated to inspection (hereinafter referred to as inspection dedicated circuit), and the presence of defects is specified by measuring the strength of the electric field or electromagnetic wave generated in the dedicated inspection circuit. Or, the defective part itself may be specified.
[0038]
When using a test-dedicated circuit, a pixel dedicated to inspection (dummy pixel) that is not used for actual display is provided in the pixel portion, and the output of the circuit or circuit element is input to the test-dedicated circuit in the pixel dedicated to test. good. This is not limited to the pixel section, and it is not necessary to input all the circuits or circuit element outputs of the element substrate to the test-dedicated circuit. Select some of the circuits or circuit elements and use the output as the test-dedicated circuit. You may make it input. Alternatively, a dummy test-dedicated circuit or circuit element not used for actual driving may be formed, and the output of the test-dedicated circuit or circuit element may be input to the test-dedicated circuit.
[0039]
As a method for monitoring electromagnetic waves and electric fields, any method may be used as long as it has a sensitivity sufficient to detect a defect in a circuit or a circuit element.
[0040]
Next, detailed configurations of the primary coil forming unit and the secondary coil forming unit (hereinafter collectively referred to as a coil forming unit) will be described. FIG. 3 shows an enlarged view of the coil.
[0041]
The coil shown in FIG. 3 (A) is in a state of spiraling in a curved shape, and coil terminals 301 and 302 are formed at both ends of the coil. In addition, the coil shown in FIG. 3B is in a state of spiraling in a rectangular shape, and coil terminals 303 and 304 are formed at both ends of the coil.
[0042]
In addition, the coil used by this invention should just form the whole wiring which a coil has on the same plane, and the wiring which a coil has spirals. Therefore, when viewed from a direction perpendicular to the plane on which the coil is formed, the wiring of the coil may be curved or may have a cornered shape.
[0043]
Further, the number of turns of the coil, the line width, and the area occupied on the substrate can be appropriately set by the designer.
[0044]
Next, FIG. 4 shows a state in which the element substrate having the coil shown in FIG. 3A as the primary coil and the inspection substrate having the coil shown in FIG. Shown in (A). Reference numeral 205 denotes an FPC that connects the inspection board 203 to a signal source and an AC power source.
[0045]
As shown in FIG. 4A, the primary coil forming unit 101 included in the inspection substrate 203 and the secondary coil forming unit 117 included in the element substrate 204 are overlapped with each other with a certain interval. It is to be noted that the interval is preferably as small as possible, and it is preferable that the primary coil forming unit 101 and the secondary coil forming unit 117 included in the element substrate 204 be as close as possible to control the interval.
[0046]
The interval between the inspection substrate 203 and the element substrate 204 may be maintained by fixing both substrates, or the element substrate 204 is fixed, and a constant flow rate or pressure between the inspection substrate 203 and the element substrate 204 is maintained. Alternatively, the gas or liquid may be kept flowing.
[0047]
FIG. 4B shows an enlarged view of a portion where the primary coil forming part 101 and the secondary coil forming part 117 overlap. Reference numeral 206 denotes a primary coil, and 207 denotes a secondary coil.
[0048]
The primary coil 206 and the secondary coil 207 have the same winding direction of the wiring, but the present invention is not limited to this configuration. The winding direction of the primary coil and the secondary coil may be reversed.
[0049]
The distance between the primary coil and the secondary coil (L _gap ) Can be set as appropriate by the designer.
[0050]
Next, a detailed configuration of the waveform shaping circuit 116a shown in FIG. 2 will be described.
[0051]
FIG. 5 shows how the signal source 201, the primary coil forming unit 101, the secondary coil forming unit 117, and the waveform shaping circuit 116a shown in FIGS. 1 and 2 are connected. The primary coil forming unit 101 is provided with a plurality of primary coils 206. The secondary coil forming unit 117 is provided with a plurality of secondary coils 207.
[0052]
Each primary coil 206 receives an AC signal for inspection from the signal source 201. When an AC signal is input to the primary coil 206, an AC voltage as an electromotive force is generated in the corresponding secondary coil 207, and the AC voltage is applied to the waveform shaping circuit 116a.
[0053]
The waveform shaping circuit 116a is an electronic circuit used for forming or shaping an amount that changes with time, that is, a waveform such as voltage or current. In FIG. 5, resistors 501 and 502 and a capacitor 503 are included, and an integrated waveform shaping circuit 116a is configured by combining each circuit element. Of course, the waveform shaping circuit is not limited to the configuration shown in FIG. Further, similarly to the power supply circuit, the waveform shaping may be performed using a detection circuit using a diode. Specifically, the waveform shaping circuit 116a used in the present invention generates and outputs a clock signal (CLK), a start pulse signal (SP), and a video signal (Video Signals) from the input AC electromotive force. Note that the signal output from the waveform shaping circuit 116a is not limited to the signal described above, and is a signal that can generate an electromagnetic wave or an electric field that can identify a defective portion by monitoring in a circuit or a circuit element included in the element substrate. Any waveform signal may be used.
[0054]
The signal output from the waveform shaping circuit 116a is input to a circuit at a subsequent stage (in FIG. 1 and FIG. 2, the signal line driver circuit 111, the scanning line driver circuit 112, and the pixel portion 113).
[0055]
Next, a detailed configuration of the rectifier circuit 116b illustrated in FIG. 2 will be described.
[0056]
FIG. 6 shows how the AC power source 202, the primary coil forming unit 101, the secondary coil forming unit 117, and the rectifier circuit 116b shown in FIGS. 1 and 2 are connected. The primary coil forming unit 101 is provided with a plurality of primary coils 206. The secondary coil forming unit 117 is provided with a plurality of secondary coils 207.
[0057]
Each primary coil 206 receives an AC signal for inspection from the AC power source 202. When an AC signal is input to the primary coil 206, an AC voltage as an electromotive force is generated in the corresponding secondary coil 207, and the AC voltage is applied to the rectifier circuit 116b.
[0058]
In the present invention, the rectifier circuit means a circuit that generates a DC power supply voltage from a supplied AC voltage. The DC power supply voltage means a voltage maintained at a constant height.
[0059]
The rectifier circuit 116b illustrated in FIG. 6 includes a diode 601, a capacitor 602, and a resistor 603. The diode 601 rectifies the input AC voltage and converts it into a DC voltage.
[0060]
FIG. 7A shows the change over time of the AC voltage before rectification in the diode 601. Further, FIG. 7B shows a time change of the voltage after rectification. As can be seen by comparing the graph of FIG. 7A and the graph of FIG. 7B, after rectification, the voltage takes a value having zero or one polarity every half cycle. It is the voltage of the current.
[0061]
The pulsating voltage shown in FIG. 7B cannot be used as a power supply voltage. Therefore, normally, the pulsating flow is smoothed and converted into a DC voltage by storing electric charge in the capacitor. However, in order to form a large-capacity capacitor that can sufficiently smooth the pulsating flow using a thin film semiconductor, the area of the capacitor itself becomes very large, which is not practical. Therefore, in the present invention, after rectification, the pulsating voltages having different phases are synthesized (added) to smooth the voltages. With the above configuration, the pulsating flow can be sufficiently smoothed even when the capacitance of the capacitor is small, and further, the pulsating flow can be sufficiently smoothed without actively providing a capacitor.
[0062]
In FIG. 6, AC signals having different phases are input to the four primary coils, so that four pulsating voltages having different phases are output from the four diodes 601. Then, the four pulsating voltages are added to generate a DC power supply voltage whose height is kept substantially constant, and is output to a subsequent circuit.
[0063]
In FIG. 6, the power supply voltage is generated by adding four pulsating signals having different phases output from the four diodes 601, but the present invention is not limited to this configuration. The number of phase divisions is not limited to this, and any number of phase divisions may be used as long as the output from the rectifier circuit can be smoothed so that it can be used as a power supply voltage.
[0064]
FIG. 8 shows a time change of the power supply voltage obtained by adding a plurality of rectified signals. FIG. 8A shows an example in which one power supply voltage is generated by adding four pulsating voltages having different phases.
[0065]
Since the power supply voltage is generated by adding a plurality of pulsating flows, ripples that are components other than direct current exist. The ripple corresponds to the difference between the highest voltage and the lowest voltage of the power supply voltage. The smaller the ripple, the closer the power supply voltage is to DC.
[0066]
FIG. 8B shows a change in power supply voltage over time, which is obtained by adding eight pulsating voltages having different phases. It can be seen that the ripple is smaller than the time change of the power supply voltage shown in FIG.
[0067]
FIG. 8C shows a time change of the power supply voltage obtained by adding 16 pulsating voltages having different phases. It can be seen that the ripple is smaller than the time change of the power supply voltage shown in FIG.
[0068]
Thus, it can be seen that the ripples of the power supply voltage are reduced by adding many different pulsating flows having different phases, and the DC voltage is further increased. Therefore, the greater the number of phase divisions, the easier the power supply voltage output from the rectifier circuit is smoothed. Further, the larger the capacitance of the capacitor 602, the easier the power supply voltage output from the rectifier circuit is smoothed.
[0069]
The power supply voltage generated in the rectifier circuit 116b is output from the terminals 610 and 611. Specifically, a voltage close to ground is output from the terminal 610, and a power supply voltage having a positive polarity is output from the terminal 611. The polarity of the output power supply voltage can be reversed by connecting the anode and cathode of the diode in reverse. The anode 602 and the cathode of the diode 602 connected to the terminals 610 and 611 are connected in reverse to the diode 601 connected to the terminals 612 and 613. Therefore, a voltage close to 0 is output from the terminal 612, and a power supply voltage having a negative polarity is output from the terminal 613.
[0070]
Various circuits or circuit elements are formed on the element substrate, and the power supply voltage to be supplied to the circuits or circuit elements varies depending on the type or application of each circuit or circuit element. In the rectifier circuit shown in FIG. 6, the height of the voltage input to each terminal can be adjusted by adjusting the amplitude of the input AC signal. Furthermore, the height of the power supply voltage supplied to the circuit or the circuit element can be changed by changing the terminal connected by the circuit or the circuit element.
[0071]
The rectifier circuit used in the present invention is not limited to the configuration shown in FIG. The rectifier circuit used in the present invention may be any circuit that can generate a DC power supply voltage from an input AC signal.
[0072]
In this embodiment mode, an example in which an element substrate has a signal line driver circuit and a scan line driver circuit which are driver circuits has been described; however, the element substrate to be inspected in the present invention is not limited thereto. Even when the element substrate has only the pixel portion, the inspection can be performed using the inspection method of the present invention. Further, even in a single element called TEG or an evaluation circuit in which the single elements are combined, it is possible to inspect defects using the inspection method and inspection apparatus of the present invention.
[0073]
In addition, although an inspection method for an element substrate included in a liquid crystal display has been described in this embodiment mode, a semiconductor display device other than a liquid crystal display can also be inspected using the inspection method described in this embodiment mode. . Further, the semiconductor device is not limited to a semiconductor display device, and any semiconductor device that uses the characteristics of a semiconductor formed on a substrate can be inspected using the inspection method of the present invention. Note that the semiconductor device may be a semiconductor device using a semiconductor thin film formed over a glass substrate, or may be a semiconductor device formed on a single crystal silicon substrate.
[0074]
However, it is necessary to appropriately set the number and design of the primary coil and the secondary coil according to the type and standard of the semiconductor device. In addition, the waveform, frequency, and amplitude of the AC signal for inspection input to the primary coil forming unit also need to be appropriately set according to the type and standard of the semiconductor device.
[0075]
According to the present invention, since the above configuration can detect a defective portion without directly setting a probe on the wiring, it is possible to prevent the yield of a subsequent process from being reduced due to fine dust generated by setting the probe. Can do. In addition, unlike the optical inspection method, the quality of all pattern forming steps can be determined in one inspection step, so that the inspection step is further simplified.
[0076]
【Example】
Examples of the present invention will be described below.
[0077]
Example 1
In this embodiment, an example will be described in which an electric field generated in a circuit or a circuit element in an inspection process is detected using an electro-optic effect. Specifically, in this embodiment, an example in which measurement is performed using a Pockels cell will be described.
[0078]
The Pockels cell is one of electro-optic elements using the Pockels effect, which is one of the electro-optic effects. An electro-optical element is an element that utilizes an electro-optical effect in which a refractive index changes when an electric field is applied. Utilizing this property, an AC voltage or a pulse voltage can be applied to the crystal and used for light modulation, shutter, and generation and detection of circularly polarized light.
[0079]
FIG. 9A shows a state in which an element substrate 901 of a liquid crystal display and a Pockels cell 909 are overlaid.
[0080]
The element substrate 901 includes a secondary coil formation portion 902, a scanning line driving circuit 903, a pixel portion 904, and a signal line driving circuit 905. Then, an inspection drive signal and a power supply voltage are input to the scanning line driver circuit 903, the pixel portion 904, and the signal line driver circuit 905 by the AC voltage generated in the secondary coil formation unit 902.
[0081]
The Pockels cell 909 includes a first electrode 906, a second electrode 907, and a Pockels crystal 908 that is a ferroelectric crystal. A Pockels crystal 908 is sandwiched between the first electrode 906 and the second electrode 907, and the first electrode 906 and the second electrode 907 are disposed so as to be perpendicular to the optical axis direction of the Pockels crystal 908. ing.
[0082]
The first electrode 906 and the second electrode 907 are formed using a conductive material that transmits light. In FIG. 9A, indium tin oxide (ITO) is used, but the material of the first electrode and the second electrode is not limited to this in the present invention.
[0083]
A constant voltage is applied to the first electrode 906. In FIG. 9A, the first electrode 906 is grounded. The first electrode 906 and the second electrode 907 are arranged in parallel with the element substrate 901 and on the second electrode 907 side. Note that the second electrode 907 may be disposed so as to be in contact with the element substrate 901 or may be disposed at a certain interval. Further, a buffer material may be sandwiched between the second electrode 907 and the element substrate 901.
[0084]
In FIG. 9A, the Pockels cell 909 is arranged so as to overlap with the pixel portion 904. FIG. 9B shows a state of the Pockels cell 909 seen from the direction of the arrow in FIG.
[0085]
A plurality of signal lines 910 and scanning lines 911 are formed in the pixel portion 904, and a region surrounded by the signal lines 910 and the scanning lines 911 corresponds to the pixels 912. Each pixel 912 (912a, 912b) is provided with a pixel electrode 913 (913a, 913b).
[0086]
Of each pixel 912, assuming that a normal pixel without a defect is 912a and a defective pixel is 912b, the portion of the Pockels cell 909 that overlaps the pixel electrode 913a overlaps the pixel electrode 913b. The light transmittance in the direction of the arrow is different from that of the portion.
[0087]
This is because when the element substrate is arranged so as to be perpendicular to the optical axis of the ferroelectric crystal included in the Pockels cell, birefringence occurs in the ferroelectric crystal due to an electric field generated in the circuit or the circuit element. .
[0088]
The refractive index of the birefringence with respect to the polarized light having the electric field direction component is determined by the strength of the electric field. Therefore, in a plurality of circuits or circuit elements having the same structure and operating normally, an electric field having the same strength is generated, so that the ferroelectric crystal is refracted in a portion overlapping each circuit or circuit element. The rates are almost equal.
[0089]
However, the electric field generated in a defective circuit or circuit element is stronger or weaker than the electric field generated in other normal circuits or circuit elements. Therefore, the refractive index of the ferroelectric crystal in a portion overlapping with a defective circuit or circuit element is different from the refractive index of the ferroelectric crystal in a portion overlapping with another normal circuit or circuit element. Therefore, when the element substrate is viewed through the Pockels cell, a portion that overlaps a defective circuit or circuit element looks brighter or darker than a portion that overlaps a normal circuit or circuit element.
[0090]
Therefore, the light in the direction perpendicular to the element substrate of each pixel is separated using an optical system such as a polarization beam splitter, and the intensity is monitored to calculate the transmittance of the Pockels cell. Can be detected. In FIG. 9B, it can be seen that some kind of defect occurs in the pixel 912b. It should be noted that some arithmetic processing may be performed on the result of monitoring a plurality of times to detect a defective portion.
[0091]
In addition, the output of all circuits to be inspected is input to the inspection dedicated circuit, and the strength of the electric field generated in the inspection dedicated circuit is measured using an electro-optic element, so that the presence or absence of defects can be specified, The location itself may be specified. By using the inspection dedicated circuit, it is not necessary to monitor every circuit or circuit element to be inspected using the Pockels cell, and the inspection process can be simplified and speeded up.
[0092]
In the present embodiment, an example in which a defect in the pixel portion 904 is detected has been described. However, the present embodiment is not limited to this. By overlapping the Pockels cell 909 with the scanning line driver circuit 903 and the signal line driver circuit 905 and monitoring the refractive index, it is possible to detect the defective portion in the same manner. In addition, it is possible to detect defects such as disconnection and short circuit that occur in the lead wiring on the element substrate.
[0093]
Note that. As Pockels crystals, mainly NH _Four H ₂ PO _Four , BaTiO _Three , KH ₂ PO _Four (KHP), KD ₂ PO _Four (KDP), LiNbO _Three Crystals such as ZnO can be used. However, the Pockels crystals that can be used in this embodiment are not limited to those described above. Any crystal having the Pockels effect may be used.
[0094]
In this embodiment, a Pockels cell is used. However, the electro-optic element for sensing the magnitude of the electric field is not limited to this. Any electro-optic element that utilizes the phenomenon that its optical characteristics change when voltage is applied can be used in the inspection method or inspection apparatus of the present invention. Therefore, liquid crystal or the like can be used.
[0095]
(Example 2)
In this embodiment, the driving signal and power supply voltage for inspection will be described in more detail by taking the case of a liquid crystal display and an OLED display as examples.
[0096]
Since the number of primary coils and secondary coils varies depending on the structure of the pixel portion of the element substrate and the drive circuit, it is important to set the number according to the standard of each element substrate.
[0097]
FIG. 10 shows a configuration of an element substrate of a general liquid crystal display. The element substrate illustrated in FIG. 10 includes a signal line driver circuit 700, a scanning line driver circuit 701, and a pixel portion 702.
[0098]
A plurality of signal lines and a plurality of scanning lines are formed in the pixel portion 702, and a region surrounded by the signal lines and the scanning lines corresponds to a pixel. Note that FIG. 10 representatively shows only a pixel having one signal line 703 and one scanning line 704 among a plurality of pixels. Each pixel has a pixel TFT serving as a switching element and a pixel electrode 706 of a liquid crystal cell.
[0099]
A gate electrode of the pixel TFT 705 is connected to the scanning line 704. One of the source region and the drain region of the pixel TFT 705 is connected to the signal line 703 and the other is connected to the pixel electrode 706.
[0100]
The signal line driver circuit 700 includes a shift register 710, a level shifter 711, and an analog switch 712. A power supply voltage (Power supply) is applied to the shift register 710, the level shifter 711, and the analog switch 712. The shift register 710 is supplied with a clock signal (S-CLK) and a start pulse signal (S-SP) for the signal line driver circuit. Video signals (Video signals) are supplied to the analog switch 712.
[0101]
When the clock signal (S-CLK) and the start pulse signal (S-SP) are input to the shift register 710, a sampling signal that determines the sampling timing of the video signal is generated and input to the level shifter 711. The amplitude of the voltage of the sampling signal is increased in the level shifter 711 and input to the analog switch 712. The analog switch 712 samples the input video signal in synchronization with the input sampling signal and inputs it to the signal line 703.
[0102]
On the other hand, the scan line driver circuit includes a shift register 721 and a buffer 722. A power supply voltage (Power supply) is supplied to the shift register 721 and the buffer 722. The shift register 721 is supplied with a clock signal (G-CLK) and a start pulse signal (G-SP) for the scanning line driver circuit.
[0103]
When a clock signal (G-CLK) and a start pulse signal (G-SP) are input to the shift register 721, a selection signal for determining the timing for selecting a scanning line is generated and input to the buffer 722. The selection signal input to the buffer 722 is buffered and amplified and input to the scanning line 704.
[0104]
When the scanning line 704 is selected, the pixel TFT 705 whose gate electrode is connected to the selected scanning line 704 is turned on. Then, the sampled video signal input to the signal line is input to the pixel electrode 706 via the pixel TFT 705 that is turned on.
[0105]
As described above, when the signal line driver circuit 700, the scan line driver circuit 701, and the pixel portion 702 operate, an electric field or an electromagnetic wave is generated in each circuit or circuit element. By monitoring this electric field or electromagnetic wave using some means, a defective part can be detected.
[0106]
In the case of the element substrate shown in FIG. 10, S-CLK, S-SP, G-CLK, G-SP and a video signal are input to each circuit as drive signals for inspection. Note that the driving signal for inspection is not limited to the signal described above. Any signal related to driving can be used as a driving signal for inspection. For example, in addition to the signals described above, a signal for determining the timing for switching the scanning direction of the scanning line, a signal for switching the input direction of the selection signal to the scanning line, or the like may be input. However, it is important to input a signal that can detect whether a circuit or a circuit element is defective in a circuit to be inspected.
[0107]
In addition, when not all the circuits included in the element substrate are inspected but a part of the circuits to be inspected, it is possible to detect all the above-described defects if it is possible to detect a defective portion of the circuit. There is no need to input a drive signal. For example, when only the shift register 710 included in the signal line driver circuit 700 is to be inspected, only the inspection drive signals S-CLK and S-SP and the inspection power supply voltage for the shift register 710 are waveformd. It may be generated in the shaping circuit and the rectifier circuit and input to the shift register 710.
[0108]
Next, FIG. 11 shows a configuration of an element substrate of a general OLED display. Note that FIG. 11 illustrates an example of a driving circuit of an OLED display that displays an image using a digital video signal. The element substrate illustrated in FIG. 11 includes a signal line driver circuit 800, a scanning line driver circuit 801, and a pixel portion 802.
[0109]
A plurality of signal lines, a plurality of scanning lines, and a plurality of power supply lines are formed in the pixel portion 802, and a region surrounded by the signal lines, the scanning lines, and the power supply lines corresponds to a pixel. Note that FIG. 11 representatively shows only a pixel having one signal line 807, one scanning line 809, and one power supply line 808 among the plurality of pixels. Each pixel has a switching TFT 803 serving as a switching element, a driving TFT 804, a storage capacitor 805, and a pixel electrode 806 of an OLED.
[0110]
A gate electrode of the switching TFT 803 is connected to the scanning line 809. One of the source region and the drain region of the switching TFT 803 is connected to the signal line 807 and the other is connected to the gate electrode of the driving TFT 804.
[0111]
One of a source region and a drain region of the driving TFT 804 is connected to the power supply line 808 and the other is connected to the pixel electrode 806. A storage capacitor 805 is formed by the gate electrode of the driving TFT 804 and the power supply line 808. Note that the storage capacitor 805 is not necessarily formed.
[0112]
The signal line driver circuit 800 includes a shift register 810, a first latch 811, and a second latch 812. The shift register 810, the first latch 811 and the second latch 812 are each supplied with a power supply voltage (Power supply). The shift register 810 is supplied with a clock signal (S-CLK) and a start pulse signal (S-SP) for the signal line driver circuit. The first latch 811 is supplied with a latch signal (Latch signals) and a video signal (Video signals) for determining the latch timing.
[0113]
When a clock signal (S-CLK) and a start pulse signal (S-SP) are input to the shift register 810, a sampling signal that determines the sampling timing of the video signal is generated and input to the first latch 811.
[0114]
Note that the sampling signal from the shift register 810 may be buffered and amplified by a buffer or the like and then input to the first latch 811. Since many circuits or circuit elements are connected to the wiring to which the sampling signal is input, the load capacitance (parasitic capacitance) is large. This buffer is effective in preventing “dullness” of the rise or fall of the timing signal caused by the large load capacity.
[0115]
The first latch 811 has a plurality of stages of latches. In the first latch 811, the input video signal is sampled in synchronization with the input sampling signal, and is sequentially stored in the latch of each stage.
[0116]
The time until video signal writing is completed in all the latches of the first latch 811 is called a line period. Actually, the line period may include a period in which a horizontal blanking period is added to the line period.
[0117]
When one line period ends, a latch signal is input to the second latch 812. At this moment, video signals written and held in the first latch 811 are sent all at once to the second latch 812, and are written and held in the latches of all stages of the second latch 812.
[0118]
In the first latch 811 which has finished sending the video signal to the second latch 812, the video signal is sequentially written based on the sampling signal from the shift register 810.
[0119]
During the second line period, the video signal written and held in the second latch 812 is input to the source signal line.
[0120]
On the other hand, the scan line driver circuit includes a shift register 821 and a buffer 822. A power supply voltage (Power supply) is supplied to the shift register 822 and the buffer 822. The shift register 821 is supplied with a clock signal (G-CLK) and a start pulse signal (G-SP) for the scanning line driver circuit.
[0121]
When a clock signal (G-CLK) and a start pulse signal (G-SP) are input to the shift register 821, a selection signal for determining the timing for selecting a scanning line is generated and input to the buffer 822. The selection signal input to the buffer 822 is buffered and amplified and input to the scanning line 809.
[0122]
When the scanning line 809 is selected, the switching TFT 803 whose gate electrode is connected to the selected scanning line 809 is turned on. Then, the video signal input to the signal line is input to the gate electrode of the driving TFT 804 via the switching TFT 803 that is turned on.
[0123]
Switching of the driving TFT 804 is controlled based on 1 or 0 information included in the video signal input to the gate electrode. When the driving TFT 804 is on, the potential of the power supply line is applied to the pixel electrode. When the driving TFT 804 is off, the potential of the power supply line is not applied to the pixel electrode.
[0124]
Thus, when the signal line driver circuit 800, the scanning line driver circuit 801, and the pixel portion 802 operate, an electric field or an electromagnetic wave is generated in each circuit or circuit element. By monitoring this electric field or electromagnetic wave using some means, a defective part can be detected.
[0125]
In the case of the element substrate shown in FIG. 11, S-CLK, S-SP, G-CLK, G-SP, a latch signal, and a video signal are input to each circuit as drive signals for inspection. Note that the driving signal for inspection is not limited to the signal described above. Any signal related to driving can be used as a driving signal for inspection. For example, in addition to the signals described above, a signal for determining the timing for switching the scanning direction of the scanning line, a signal for switching the input direction of the selection signal to the scanning line, or the like may be input. However, it is important to input a signal that can detect whether a circuit or a circuit element is defective in a circuit to be inspected.
[0126]
In addition, when not all the circuits included in the element substrate are inspected but a part of the circuits to be inspected, it is possible to detect all the above-described defects if it is possible to detect a defective portion of the circuit. There is no need to input a drive signal. For example, when only the shift register 810 included in the signal line driver circuit 800 is to be inspected, only the inspection drive signals S-CLK and S-SP and the inspection power supply voltage for the shift register 810 have waveforms. It may be generated in the shaping circuit and the rectifier circuit and input to the shift register 810.
[0127]
When the power supply voltage is generated by adding a plurality of pulsating signals having different phases, the number of primary coils varies depending on the number of pulsating signals to be added.
[0128]
The inspection apparatus and inspection method of the present invention are not limited to the element substrate having the structure shown in FIGS. The inspection apparatus and inspection method of the present invention may be any semiconductor device that generates an electromagnetic wave or an electric field in each circuit or circuit element by inputting a drive signal and a power supply voltage in a non-contact manner. Can be used.
[0129]
This embodiment can be implemented by freely combining with the first embodiment.
[0130]
(Example 3)
In the present embodiment, a line for cutting the substrate after completion of the inspection will be described.
[0131]
FIG. 12 shows a top view of an element substrate to be inspected in the inspection method of the present invention. Note that in this embodiment mode, the inspection method of the present invention is described using an element substrate included in a liquid crystal display as an example. However, the inspection method of the present invention is not limited to a liquid crystal display and uses a semiconductor. Any semiconductor device formed as described above can be used.
[0132]
The element substrate shown in FIG. 12 has a signal line driver circuit 411, a scan line driver circuit 412, a pixel portion 413, a lead wiring 414, a connector connection portion 415, a waveform shaping circuit or a rectifier circuit 416, a secondary on the substrate 410. A coil forming portion 417 and a coil wiring 418 are provided. Note that in this specification, the element substrate includes the substrate 410 and all circuits or circuit elements formed on the substrate 410.
[0133]
FPC or TAB or the like is connected to the connector connecting portion 415 in a step after the inspection step.
[0134]
Then, after the inspection process is completed, the element substrate is cut along a dotted line BB ′ so that the drawing wiring 414 and the coil wiring 418 are physically and electrically separated. In the present embodiment, after part of the element substrate is cut, the secondary coil forming portion 417 remains on the substrate used in the semiconductor device. Since the secondary coil forming portion 417 and the lead wiring 414 are separated electrically and physically, even if the secondary coil forming portion 417 remains on the substrate, the operation of the completed semiconductor device is not necessary. It will not cause any trouble.
[0135]
Note that the coil wiring 418 is not necessarily cut off simultaneously with the cutting of the substrate. For example, it may be electrically disconnected with a laser or the like. The coil wiring 418 may be cut as long as the secondary coil forming portion 417 and the circuit or circuit element included in the element substrate can be electrically separated.
[0136]
Note that the waveform shaping circuit or the rectifier circuit 416 may also be left on the substrate used for the semiconductor device after cutting, or may be formed on the substrate not used for the semiconductor device.
[0137]
This embodiment can be implemented by freely combining with the configuration of Embodiment 1 or 2.
[0138]
(Example 4)
In this embodiment, when a plurality of display substrates are formed using a large element substrate, cutting of the substrate after completion of the inspection will be described.
[0139]
FIG. 13 shows a top view of a large element substrate before cutting according to this embodiment. In FIG. 13, nine display substrates are formed from one element substrate by cutting the element substrate along a line indicated by a dotted line. Note that, in this embodiment, an example in which nine display substrates are formed from one substrate is shown, but this embodiment is not limited to this number.
[0140]
At the time of cutting, the lead-out wiring and the coil wiring are cut and destroyed so as to be physically and electrically separated. In FIG. 13, the secondary coil forming portion 1001 is provided on the substrate not used for display after the element substrate is cut.
[0141]
An example different from FIG. 13 will be described with respect to how to cut a large substrate. FIG. 14 shows a top view of a large element substrate before cutting according to this embodiment. In FIG. 14, nine display substrates are formed from one element substrate by cutting the element substrate along a line indicated by a dotted line. Note that, in this embodiment, an example in which nine display substrates are formed from one substrate is shown, but this embodiment is not limited to this number.
[0142]
At the time of cutting, the lead-out wiring and the coil wiring are cut and destroyed so as to be physically and electrically separated. And in FIG. 14, the secondary coil formation part 1002 is provided on the cutting line of a board | substrate, and is cut | disconnected and destroyed after completion | finish of a test | inspection. Since the secondary coil forming portion is unnecessary after the inspection is completed, there is no problem in the operation of the completed semiconductor device.
[0143]
Note that the waveform shaping circuit or the rectifier circuit may be left on the substrate used for the semiconductor device after cutting, or may be formed on the substrate not used for the semiconductor device. Moreover, it may be destroyed after cutting.
[0144]
This embodiment can be implemented by freely combining with the configurations of the first to third embodiments.
[0145]
(Example 5)
In this embodiment, the order of the inspection process of the present invention will be described using a flowchart.
[0146]
FIG. 15 shows a flowchart of the inspection process of the present invention. First, after the manufacturing process before inspection is completed, a power supply voltage or a driving signal for inspection is input to a circuit or a circuit element included in the element substrate.
[0147]
Then, with the inspection power supply voltage or drive signal being input to the element substrate, the strength of the electromagnetic wave or electric field generated in the circuit or circuit element to be inspected on the element substrate is monitored by a known measurement method. .
[0148]
Then, the intensity of the generated electromagnetic wave or electric field is compared with a circuit element operating normally. At this time, the measured value may be compared between the same circuits or circuit elements, or the measured value may be compared with a value derived from a theoretical value calculated by simulation.
[0149]
Then, as a result of comparison, a circuit or a circuit element that is determined to have a significantly different electromagnetic wave or electric field strength is determined as a defective portion. Therefore, it is possible to simultaneously specify the presence / absence of a defective portion and its position. At this time, the criteria for determining the strength of the electromagnetic wave or electric field generated at the defective portion can be set as appropriate by a person who implements the present invention.
[0150]
If there is no defect, it is considered that the inspection is completed at this point, and the manufacturing process after the inspection process is started.
[0151]
If there is a defect, it is selected whether to remove the product from the process and not complete the product (lotout) or to identify the cause of the defect. In addition, when it is going to produce a some product from one large sized board | substrate, it becomes a lot-out after board | substrate cutting | disconnection.
[0152]
When the cause of the defect is specified and it is determined that repair (repair) is possible, after the repair, the inspection process of the present invention is performed again, and the above-described operation can be repeated. On the other hand, if it is determined that repair is impossible, the lot is out.
[0153]
The present embodiment can be implemented by freely combining with the configurations of the first to fourth embodiments.
[0154]
(Example 6)
In this embodiment, the coil used in the present invention and the connection between the terminal and the wiring (coil wiring) of the coil will be described in detail.
[0155]
In FIG. 16A, a coil 1601 is formed on the insulating surface, and an interlayer insulating film 1603 is formed on the insulating surface so as to cover the coil 1601. A contact hole is formed in the interlayer insulating film, and a coil wiring 1602 is formed on the interlayer insulating film so as to be connected to the coil 1601 through the contact hole.
[0156]
FIG. 16B is a cross-sectional view taken along dashed line CC ′ in FIG.
[0157]
In FIG. 16C, a coil wiring 1612 is formed on the insulating surface, and an interlayer insulating film 1613 is formed on the previous insulating surface so as to cover the coil wiring 1612. A contact hole is formed in the interlayer insulating film, and a coil 1611 is formed on the interlayer insulating film so as to be connected to the coil wiring 1612 via the contact hole.
[0158]
FIG. 16D is a cross-sectional view taken along dashed line DD ′ in FIG.
[0159]
Note that the method for manufacturing the coil used in the present invention is not limited to the above-described method. A spiral groove is formed by patterning the insulating film, and a conductive film is formed on the insulating film so as to cover the groove. Thereafter, the conductive film is polished by etching or CMP until the insulating film is exposed, so that the conductive film remains only in the groove. It is also possible to use the conductive film remaining in this groove as a coil.
[0160]
The present embodiment can be implemented by freely combining with the configurations of the first to fifth embodiments.
[0161]
(Example 7)
In the present embodiment, the configuration of an inspection apparatus for performing inspection using the inspection method of the present invention will be described.
[0162]
FIG. 17 shows a block diagram of the inspection board of the present invention. The inspection apparatus 1700 of the present invention shown in FIG. 17 includes an inspection substrate 1701, a signal source or AC power source 1702, and means for superimposing the inspection substrate 1701 and the element substrate 1703 at a predetermined interval (substrate fixing means 1704). And a means (inspection unit 1705) for measuring an electric field or electromagnetic wave generated in an inspection dedicated circuit included in the element substrate 1703 and specifying a defective portion.
[0163]
In this embodiment, the signal source or the AC power source 1702 is regarded as a part of the inspection device, but the inspection device of the present invention may not include the signal source or the AC power source 1702.
[0164]
An AC signal generated by the signal source or the AC power source 1702 is input to an external input buffer 1706 included in the inspection board 1701. The input AC signal is buffered and amplified in the external input buffer 1706 and input to the primary coil forming unit 1707 included in the inspection board 1701.
[0165]
A primary coil is formed in the primary coil forming portion 1707. Note that a secondary coil is formed in the secondary coil forming portion 1711 of the element substrate 1703.
[0166]
On the other hand, the inspection substrate 1701 and the element substrate 1703 are formed by the substrate fixing unit 1704 so that the primary coil included in the primary coil forming unit 1707 and the secondary coil included in the secondary coil forming unit 1711 overlap each other with a certain interval. Its position is determined.
[0167]
Then, a power supply voltage or a drive signal generated by an AC voltage generated in the secondary coil forming unit 1711 is input to a circuit or a circuit element 1712 included in the element substrate 1703. Note that a circuit for generating a power supply voltage or a drive signal included in the element substrate 1703 has already been described in detail in the embodiment of the invention, and thus description thereof is omitted here.
[0168]
Then, the measurement unit 1708 included in the inspection unit 1705 measures the strength of the electromagnetic wave or electric field generated in the circuit or the circuit element 1712. Data (measured values) digitized by measurement is sent to a calculation unit 1709 included in the inspection unit 1705.
[0169]
The calculation unit 1709 identifies a defective part based on the input data. Specifically, a circuit element in which the intensity of the generated electric field or electromagnetic wave is significantly different from the intensity of the electric field or electromagnetic wave generated in a normal circuit element is determined as a defective portion.
[0170]
The following method is mentioned as a method of comparing the intensity of the electric field or electromagnetic wave.
(1) A method of comparing the same circuit or the same circuit elements of the element substrate to be inspected.
(2) Separately prepare an element substrate having a circuit or a circuit element which is already known to be normal. Then, the intensity of the electromagnetic wave or electric field generated in the circuit or circuit element of the substrate is measured, and the data is stored in a memory or the like. And the method of measuring the electric field or electromagnetic wave which generate | occur | produces in the element board | substrate to be examined, and comparing with the data memorize | stored in memory.
(3) A method of comparing the distribution of the intensity of the electric field or electromagnetic wave depending on the position of the element substrate with the mask drawing.
[0171]
The above-described comparison method is only an example, and the present invention is not limited to this. It is only necessary to detect a circuit element in which the intensity of the generated electric field or electromagnetic wave is significantly different from the intensity of the electric field or electromagnetic wave generated in a normal circuit element.
[0172]
In the present embodiment, the defect portion is specified in the inspection unit 1705, but the inspection apparatus of the present invention is not limited to this configuration. Instead of the inspection unit 1705, a means for visualizing the strength of the electromagnetic wave or electric field may be provided so that the strength of the electromagnetic wave or electric field generated in the element substrate 1703 can be directly determined by the human eye.
[0173]
Note that outputs of all circuits or circuit elements to be inspected are input to the inspection dedicated circuit. The inspection dedicated circuit performs a logical operation process on a plurality of operation signals input from the inspection object, and outputs the operation state information (operation, non-operation or partial operation state) of the inspection object, and the output Means for amplifying.
[0174]
In this embodiment, the test-dedicated circuit outputs the first level signal only when the levels (voltage levels) of the input signals are almost the same, and even one signal having a different level is output. If there is, means for outputting a second level signal different from the first level signal, and means for amplifying the output.
[0175]
Then, the amplified output is input to a predetermined terminal (pad), and the presence of defects in all the circuits or circuit elements to be inspected is confirmed by measuring the intensity of the electric field or electromagnetic wave generated at the pad. Can do. Further, the smaller the number of circuits or circuit elements connected to one inspection-dedicated circuit, the more limited the range in which a defective portion exists. As the number of circuits or circuit elements connected to one inspection-dedicated circuit is larger, the presence or absence of defects in more circuits or circuit elements can be confirmed by one measurement.
[0176]
The present embodiment can be implemented by freely combining with the configurations of the first to sixth embodiments.
[0177]
【The invention's effect】
According to the present invention, since the above configuration can detect a defective portion without directly setting a probe on the wiring, it is possible to prevent the yield of a subsequent process from being reduced due to fine dust generated by setting the probe. Can do. In addition, unlike the optical inspection method, the quality of all pattern forming steps can be determined in one inspection step, so that the inspection step is further simplified.
[Brief description of the drawings]
FIG. 1 is a top view of an inspection substrate and an element substrate.
FIG. 2 is a block diagram of an inspection substrate and an element substrate.
FIG. 3 is an enlarged view of a coil.
FIG. 4 is a perspective view of an inspection substrate and an element substrate at the time of inspection.
FIG. 5 is a circuit diagram of a waveform shaping circuit.
FIG. 6 is a circuit diagram of a rectifier circuit.
FIG. 7 shows the change over time of a signal that has been rectified from an alternating current to become a pulsating flow.
FIG. 8 shows the change over time of a DC signal generated by adding pulsating currents.
FIG. 9 is a perspective view of an element substrate and a Pockels cell at the time of inspection, and a diagram of a pixel portion viewed through the Pockels cell.
FIG. 10 is a block diagram of an element substrate of a liquid crystal display.
FIG. 11 is a block diagram of an element substrate of an OLED display.
FIG. 12 is a top view of an element substrate.
FIG. 13 is a top view of a large element substrate.
FIG. 14 is a top view of a large element substrate.
FIG. 15 is a flowchart showing a flow of an inspection process according to the present invention.
FIG. 16 is a top view and a cross-sectional view of a coil.
FIG. 17 is a block diagram of an inspection apparatus.

Claims (24)

A plurality of primary coils formed on an inspection substrate and a plurality of secondary coils formed on an element substrate including a plurality of display substrates are overlapped with a certain interval, respectively.
AC voltages having different phases are applied to the plurality of primary coils,
The voltage generated in the plurality of secondary coils is rectified and then added to generate a DC voltage,
Applying the DC voltage to a plurality of circuit elements formed on the element substrate;
Collecting information on electric fields generated in the plurality of circuit elements;
From the collected information, among the plurality of circuit elements that the element substrate has, identify a circuit element having a defect,
The plurality of secondary coils are provided on a cutting line for dividing the plurality of display substrates, and are cut by leaving a part of each of the plurality of display substrates after completion of the inspection , inspection method according to claim Rukoto destroyed. A plurality of primary coils formed on an inspection substrate and a plurality of secondary coils formed on an element substrate including a plurality of display substrates are overlapped with a certain interval, respectively.
Applying an alternating voltage to the plurality of primary coils;
Generating a drive signal from voltages generated in the plurality of secondary coils;
Applying the drive signal to a plurality of circuit elements formed on the element substrate;
Collecting information on electric fields generated in the plurality of circuit elements;
From the collected information, among the plurality of circuit elements that the element substrate has, identify a circuit element having a defect,
The plurality of secondary coils are provided on a cutting line for dividing the plurality of display substrates, and are cut by leaving a part of each of the plurality of display substrates after completion of the inspection , inspection method according to claim Rukoto destroyed. A plurality of primary coils formed on an inspection substrate and a plurality of secondary coils formed on an element substrate including a plurality of display substrates are overlapped with a certain interval, respectively.
Applying an alternating voltage to the plurality of primary coils;
A voltage generated in the plurality of secondary coils is used to generate a drive signal in a waveform shaping circuit formed on the element substrate,
Applying the drive signal to a plurality of circuit elements formed on the element substrate;
Collecting information on electric fields generated in the plurality of circuit elements;
From the collected information, among the plurality of circuit elements that the element substrate has, identify a circuit element having a defect,
The plurality of secondary coils are provided on a cutting line for dividing the plurality of display substrates, and are cut by leaving a part of each of the plurality of display substrates after completion of the inspection , inspection method according to claim Rukoto destroyed. In any one of Claims 1 thru | or 3 ,
An inspection method, wherein wirings of the plurality of primary coils are formed on the same plane, and the wirings are spirally wound. In any one of claims 1 to 4, the means for collecting information of the electric field, inspection method, characterized in that the means for measuring the intensity of the electric field. 6. The inspection method according to claim 5 , wherein the means for measuring the strength of the electric field includes an electro-optic element. In claim 6 ,
The electro-optical element is a Pockels cell. A plurality of primary coils formed on an inspection substrate and a plurality of secondary coils formed on an element substrate including a plurality of display substrates are overlapped with a certain interval, respectively.
AC voltages having different phases are applied to the plurality of primary coils,
The voltage generated in the plurality of secondary coils is rectified and then added to generate a DC voltage,
Applying the DC voltage to a plurality of circuit elements formed on the element substrate;
Collecting information on electromagnetic waves generated in the plurality of circuit elements;
From the collected information, among the plurality of circuit elements that the element substrate has, identify a circuit element having a defect,
The plurality of secondary coils are provided on a cutting line for dividing the plurality of display substrates, and are cut by leaving a part of each of the plurality of display substrates after completion of the inspection , inspection method according to claim Rukoto destroyed. A plurality of primary coils formed on an inspection substrate and a plurality of secondary coils formed on an element substrate including a plurality of display substrates are overlapped with a certain interval, respectively.
Applying an alternating voltage to the plurality of primary coils;
Generating a drive signal from voltages generated in the plurality of secondary coils;
Applying the drive signal to a plurality of circuit elements formed on the element substrate;
Collecting information on electromagnetic waves generated in the plurality of circuit elements;
From the collected information, among the plurality of circuit elements that the element substrate has, identify a circuit element having a defect,
The plurality of secondary coils are provided on a cutting line for dividing the plurality of display substrates, and are cut by leaving a part of each of the plurality of display substrates after completion of the inspection , inspection method according to claim Rukoto destroyed. A plurality of primary coils formed on an inspection substrate and a plurality of secondary coils formed on an element substrate including a plurality of display substrates are overlapped with a certain interval, respectively.
Applying an alternating voltage to the plurality of primary coils;
A voltage generated in the plurality of secondary coils is used to generate a drive signal in a waveform shaping circuit formed on the element substrate,
Applying the drive signal to a plurality of circuit elements formed on the element substrate;
Collecting information on electromagnetic waves generated in the plurality of circuit elements;
From the collected information, among the plurality of circuit elements that the element substrate has, identify a circuit element having a defect,
The plurality of secondary coils are provided on a cutting line for dividing the plurality of display substrates, and are cut by leaving a part of each of the plurality of display substrates after completion of the inspection , inspection method according to claim Rukoto destroyed. In any one of claims 8 to 10, and means for collecting information of the electromagnetic wave, the inspection method, characterized in that the means for measuring the intensity of electromagnetic waves. In any one of Claims 8 thru | or 11 ,
An inspection method, wherein wirings of the plurality of primary coils are formed on the same plane, and the wirings are spirally wound. A plurality of primary coils formed on an inspection substrate and a plurality of secondary coils formed on an element substrate including a plurality of display substrates are overlapped with a certain interval, respectively.
AC voltages having different phases are applied to the plurality of primary coils,
The voltage generated in the plurality of secondary coils is rectified and then added to generate a DC voltage,
Applying the DC voltage to a plurality of circuit elements formed on the element substrate;
The outputs of the plurality of circuit elements are input to a test-dedicated circuit,
Collect information on the electric field generated at the terminals of the test-dedicated circuit,
From the collected information, among the plurality of circuit elements that the element substrate has, identify a circuit element having a defect,
The plurality of secondary coils are provided on a cutting line for dividing the plurality of display substrates, and are cut by leaving a part of each of the plurality of display substrates after completion of the inspection , inspection method according to claim Rukoto destroyed. A plurality of primary coils formed on an inspection substrate and a plurality of secondary coils formed on an element substrate including a plurality of display substrates are overlapped with a certain interval, respectively.
Applying an alternating voltage to the plurality of primary coils;
A voltage generated in the plurality of secondary coils is used to generate a drive signal in a waveform shaping circuit formed on the element substrate,
Applying the drive signal to a plurality of circuit elements formed on the element substrate;
The outputs of the plurality of circuit elements are input to a test-dedicated circuit,
Collect information on the electric field generated at the terminals of the test-dedicated circuit,
From the collected information, among the plurality of circuit elements that the element substrate has, identify a circuit element having a defect,
The plurality of secondary coils are provided on a cutting line for dividing the plurality of display substrates, and are cut by leaving a part of each of the plurality of display substrates after completion of the inspection , inspection method according to claim Rukoto destroyed. In claim 13 or claim 14 ,
The inspection dedicated circuit is:
When the output levels of the plurality of circuit elements are all the same, a first level signal is output. When the levels of at least one of the outputs of the plurality of circuit elements are different, the first level is output. First means for outputting a second level signal different from the second level signal;
Second means for amplifying the output from the first means,
An inspection method, wherein an output from the second means is input to the terminal. 16. The inspection method according to claim 13 , wherein the means for collecting electric field information is means for measuring electric field strength. 17. The inspection method according to claim 16 , wherein the means for measuring the strength of the electric field includes an electro-optic element. In claim 17 ,
The electro-optical element is a Pockels cell. A plurality of primary coils formed on an inspection substrate and a plurality of secondary coils formed on an element substrate including a plurality of display substrates are overlapped with a certain interval, respectively.
AC voltages having different phases are applied to the plurality of primary coils,
The voltage generated in the plurality of secondary coils is rectified and then added to generate a DC voltage,
Applying the DC voltage to a plurality of circuit elements formed on the element substrate;
The outputs of the plurality of circuit elements are input to a test-dedicated circuit,
Collect information on electromagnetic waves generated at the terminals of the test-dedicated circuit,
From the collected information, among the plurality of circuit elements that the element substrate has, identify a circuit element having a defect,
The plurality of secondary coils are provided on a cutting line for dividing the plurality of display substrates, and are cut by leaving a part of each of the plurality of display substrates after completion of the inspection , inspection method according to claim Rukoto destroyed. A plurality of primary coils formed on an inspection substrate and a plurality of secondary coils formed on an element substrate including a plurality of display substrates are overlapped with a certain interval, respectively.
Applying an alternating voltage to the plurality of primary coils;
A voltage generated in the plurality of secondary coils is used to generate a drive signal in a waveform shaping circuit formed on the element substrate,
Applying the drive signal to a plurality of circuit elements formed on the element substrate;
The outputs of the plurality of circuit elements are input to a test-dedicated circuit,
Collect information on electromagnetic waves generated at the terminals of the test-dedicated circuit,
From the collected information, among the plurality of circuit elements that the element substrate has, identify a circuit element having a defect,
The plurality of secondary coils are provided on a cutting line for dividing the plurality of display substrates, and are cut by leaving a part of each of the plurality of display substrates after completion of the inspection , inspection method according to claim Rukoto destroyed. In claim 19 or claim 20 ,
The inspection dedicated circuit is:
When the output levels of the plurality of circuit elements are all the same, a first level signal is output. When the levels of at least one of the outputs of the plurality of circuit elements are different, the first level is output. First means for outputting a second level signal different from the second level signal;
Second means for amplifying the output from the first means,
An inspection method, wherein an output from the second means is input to the terminal. The inspection method according to any one of claims 19 to 21 , wherein the means for collecting information on the electromagnetic wave is a means for measuring the intensity of the electromagnetic wave. In any one of Claim 13 thru | or Claim 22 ,
An inspection method, wherein wirings of the plurality of primary coils are formed on the same plane, and the wirings are spirally wound. 24. In any one of claims 1 to 23 ,
The said fixed space | interval is controlled by flowing gas or a liquid between the said board | substrate for an inspection and the said element substrate, The inspection method characterized by the above-mentioned.

Images