JP4177222B2 - Liquid crystal display device and inspection method thereof - Google Patents

Description

  The present invention relates to a liquid crystal display device using a COG method in which a driving IC is mounted on a peripheral portion of one of two insulating substrates stacked via a liquid crystal layer, and an inspection method thereof. Is.

  With the development of an advanced information society, the field of liquid crystal display devices has made remarkable progress. In order to further spread the liquid crystal display device, it is important to reduce the price by improving productivity. In a conventional liquid crystal display device, a driver LSI for driving a switching element in a pixel is supplied in the form of TCP (Tape Carrier Package), and two of the insulating substrates stacked via liquid crystal are One electrode substrate provided on the peripheral edge of the surface of one insulating substrate was connected using an ACF (Anisotropic Conductive Film). Note that TCP is a circuit board formed by bonding a copper foil to a polyimide film and then using a photolithographic technique. A driver LSI having Au bumps is formed on a flexible substrate in which Sn is plated on the circuit. Connected and mounted with eutectic alloy. ACF is a film in which plastic particles covered with Ni / Au plating or Ni particles are dispersed in an insulating resin such as epoxy.

In this method, when a display defect such as a line defect is found in the lighting inspection after the TCP is connected to the peripheral edge of the substrate, it is connected to the oscilloscope at the exposed copper foil at the tip of the TCP output terminal row. By connecting the stylus and measuring the output waveform from the driver LSI, it is easy to determine whether the cause of the display failure is the driver LSI side, or the wiring or switching element formed on the substrate I was able to.
Further, by analyzing the measured waveform of the driver LSI, the cause of the failure of the driver LSI has been elucidated, the yield of non-defective products of the driver LSI can be improved, and an inexpensive liquid crystal display element can be provided.

  On the other hand, in recent years, a COG (Chip On Glass) method has been adopted as a cheaper manufacturing method of liquid crystal display elements. A method of connecting a driver LSI and an external circuit using a COG method at an electrode terminal portion of a general liquid crystal display device will be described. First, ACF is affixed on the electrode terminal formed on the peripheral part of the electrode substrate surface. Next, after a plurality of bump electrodes made of Au formed on the back surface of the driver LSI and the electrode terminals are aligned with high accuracy, thermocompression bonding is performed using a heating and pressing tool. The conditions at this time are a heating temperature of 170 to 200 degrees Celsius, a time of 10 to 20 seconds, and a pressure of 30 to 100 Pa. As a result, the conductive particles of ACF sandwiched between the bump electrodes and the electrode terminals of the driver LSI conduct only in the vertical direction. In the horizontal direction, insulation is maintained because an insulating epoxy resin exists around the conductive particles. As a result, the driver LSI is directly mounted on the electrode terminal. Further, the connection between the electrode terminal and the FPC (flexible wiring board) for transmitting the drive signal and power from the external circuit board to the driver LSI is performed in the same manner.

Japanese Patent Laying-Open No. 2003-167265 (pages 4-7, FIG. 1)

In a liquid crystal display device using a conventional COG method, a solution when a display defect of a line defect occurs in a lighting inspection after mounting a driver LSI is disclosed in Patent Document 1. In this patent document 1, when a cross wiring that intersects with a source line array via a gate insulating film is arranged at the peripheral portion of the electrode substrate surface, and a display defect of a line defect occurs in a lighting inspection after mounting a driver LSI. Measure the output waveform of the driver LSI by irradiating the YAG laser from the back side of the substrate to connect the source wiring and cross wiring to the cross section of the source wiring and cross wiring, connecting the source wiring and cross wiring, and applying the probe and needle connected to the oscilloscope As a result, the cause of the display failure was investigated.
However, in the method of Patent Document 1, since the cross wiring electrode is on the glass substrate, there is a problem that the probe and the needle are not reliably in contact with each other, and the glass may be broken in some cases.

The present invention has been made in order to solve the above-mentioned problems, and in the case where a display defect occurs in a lighting inspection after the driver LSI is mounted, a liquid crystal that can easily investigate the cause of the display defect. The first object is to obtain a display device.
It is a second object of the present invention to obtain a liquid crystal display inspection method that can easily determine the cause of a display failure when a display failure occurs in a lighting inspection after the driver LSI is mounted.

In the liquid crystal display device according to the present invention, in the liquid crystal display device having the display unit in which the liquid crystal layer is sandwiched between the electrode substrate and the counter substrate disposed to face the electrode substrate, the peripheral portion of the electrode substrate Output wiring electrode terminals respectively disposed on the display unit, a plurality of output wirings for supplying a driving signal to the display unit, the plurality of output wirings disposed so as to intersect with each other through an insulating film, and a cross wiring electrode cross wire, is disposed on the periphery of the electrode substrate while have a plurality of output bumps coupled to the output wiring electrode terminal, the drive IC for outputting a driving signal to the output line, and connected to the cross wiring electrodes of cross wire A flexible wiring board having a monitor wiring and a measurement pad connected to the monitor wiring,
The probe connected to the measuring device is brought into contact with the measuring pad of the flexible wiring board.
In the inspection method for a liquid crystal display device according to the present invention, a display in which a liquid crystal layer is sandwiched between an electrode substrate provided with a plurality of output wirings and a counter substrate arranged to face the electrode substrate. Liquid crystal display device inspection method for identifying a cause when a display failure occurs in a liquid crystal display device in which a portion is driven by a driving IC joined to an output wiring electrode terminal of an output wiring arranged on the peripheral portion of the electrode substrate In the step of identifying the address of the output wiring related to the occurrence of the display defect, the cross wiring arranged to intersect the plurality of output wirings and the intersection of the electrode wiring of the identified address intersect A process of irradiating a laser from the back side to connect the output wiring of the specified address and the cross wiring, and a measurement pad provided on the flexible wiring board connected to the cross wiring. Alternatively, the probe connected to the measuring device is brought into contact with the measurement pad provided on the circuit board connected to the flexible wiring board, and the output waveform and output voltage from the driving IC flowing on the output wiring of the specified address are obtained. It includes a measuring step.

Since the present invention is configured as described above, the following effects can be obtained.
In a liquid crystal display device having a display unit in which a liquid crystal layer is sandwiched between an electrode substrate and a counter substrate disposed so as to face the electrode substrate, output wiring electrode terminals disposed on the periphery of the electrode substrate are respectively A plurality of output wirings for supplying a driving signal to the display unit, crossing the plurality of output wirings through an insulating film and having cross wiring electrodes, coupled to output wiring electrode terminals, respectively is disposed on the periphery of the electrode substrate while have a plurality of output bumps which are, connected to the output driving IC wiring for outputting a drive signal, and the cross wire of cross wire connected to the electrode the monitor lines and the monitor lines A flexible wiring board having a measured pad,
Since the probe connected to the measuring device is in contact with the measurement pad of the flexible wiring board, the output waveform and output voltage from the drive IC flowing on the output wiring are measured by the probe that is in contact with the measurement pad of the flexible wiring board. It is possible to easily investigate the cause of display defects without damaging the electrode substrate.
In addition, an output unit in which a liquid crystal layer is sandwiched between an electrode substrate provided with a plurality of output wirings and a counter substrate disposed so as to face the electrode substrate is disposed at the peripheral portion of the electrode substrate. In an inspection method of a liquid crystal display device for identifying a cause when a display failure occurs in a liquid crystal display device driven by a driving IC bonded to an output wiring electrode terminal of the wiring, an address of an output wiring related to the occurrence of the display failure Irradiating laser from the back side of the electrode substrate to the intersection where the cross wiring arranged to intersect the plurality of output wirings and the output wiring of the specified address intersects, The step of connecting the output wiring and the cross wiring, and the measurement pad provided on the flexible wiring board connected to the cross wiring or the circuit board connected to the flexible wiring board A measurement pad provided on the measuring device is brought into contact with a probe connected to the measuring device, and the output waveform and output voltage from the driving IC flowing on the output wiring of the specified address are measured. The probe connected to the measuring device can be brought into contact with the measuring pad on the measuring pad or the circuit board, and the output waveform and output voltage from the driving IC that flows on the output wiring can be measured. It is possible to easily investigate the cause.

Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 is a plan view showing an electrode terminal portion of a liquid crystal display device according to Embodiment 1 of the present invention.
In FIG. 1, an electrode substrate 1 and a counter substrate 2 having an end 2a are arranged to face each other with a liquid crystal layer interposed therebetween. A driver LSI 3 (driving IC) is mounted on the periphery of the electrode substrate 1. A source wiring row 4a including a source wiring 4 (output wiring) is arranged on the peripheral edge of the electrode substrate 1, and each source electrode terminal 4b (output wiring electrode terminal) is provided to form a source electrode terminal block 4c. Yes. Cross wirings 5 are arranged so as to cross the source electrode terminal 4b with a gate insulating film interposed therebetween, and cross wiring electrodes 5b and 5c are provided at both ends of the cross wiring 5 respectively. An input wiring 8 of the driver LSI 3 is formed at the outermost end of the electrode substrate 1, an LSI electrode 8a connected to an input bump of the driver LSI 3 is provided at one end thereof, and the other end is provided with an LSI electrode 8a. An FPC electrode 8b connected to an FPC (flexible wiring board) is provided.

2 is a partial cross-sectional view showing an electrode terminal portion of the liquid crystal display device according to Embodiment 1 of the present invention, and is a partial cross-sectional view cut along AA in FIG.
In FIG. 2, 1-5, 2a, 4b, 8, 8a, 8b are the same as those in FIG. The driver LSI 3 is provided with an input bump 3a connected to the LSI electrode 8a and an output bump 3b connected to the source electrode terminal 4b. The source wiring 4 and the cross wiring 5 intersect via the gate insulating film 6, and a passivation film 7 is disposed on the source wiring 4. The FPC 9 has a copper foil 9b connected to the FPC electrode 8b.

In the first embodiment, a liquid crystal display in which a transistor having an inverted staggered structure using amorphous silicon (hereinafter referred to as a-Si) is used as a semiconductor layer and a driver LSI is mounted on a peripheral portion of an electrode substrate using a COG method. The apparatus will be described. First, the structure of the liquid crystal display device will be briefly described.
The liquid crystal display device includes a display unit in which a plurality of liquid crystal display elements are formed with a liquid crystal layer sandwiched between an electrode substrate 1 and two opposing substrates 2 which are two opposing insulating substrates. In the display portion of the electrode substrate, a plurality of gate wirings and source wirings 4, thin film transistors which are switching elements arranged near their intersections, pixel electrodes connected to the thin film transistors, and the like are arranged in a matrix. . In addition, a counter electrode made of a transparent conductive film, a color filter layer for color display, a black matrix disposed between pixels, and the like are formed on the display portion of the counter substrate. The electrode substrate and the counter electrode are connected to each other by a sealing material overlapped with a liquid crystal layer and a spacer.

Next, the configuration will be described in more detail with reference to FIGS.
An electrode terminal portion is formed on a peripheral portion located on the outer periphery of the display portion of the electrode substrate 1, and a driver LSI 3 that is a driving IC for driving the liquid crystal display element is mounted thereon.
Next, the source side electrode terminal portion will be described.
On the peripheral edge of the electrode substrate 1, a source wiring row 4 a including a source wiring 4 that is a plurality of output wirings connected to a plurality of liquid crystal display elements of the display section is arranged. A source electrode terminal 4 b to which the output bump 3 b of the driver LSI 3 is joined is provided at the tip of the source wiring 4. Therefore, the same number of source electrode terminals 4b as the plurality of output bumps 3b of the driver LSI 3 are arranged close to each other to constitute a source electrode block 4c. Further, one cross wiring 5 is disposed between the LSI electrode 8a row and the source electrode terminal 4b row of the driver LSI 3.

The cross wiring 5 is formed of a metal layer different from that of the source wiring 4. In the first embodiment, the cross wiring 5 is formed of the same metal layer as the gate wiring. For this reason, the cross wiring 5 intersects with the source wiring row 4 b via the gate insulating film 6. Further, the cross wiring 5 is provided with cross wiring electrodes 5b and 5c which can be FPC-connected at the tip portions on both sides thereof. The cross wiring electrodes 5b and 5c are not covered with the gate insulating film 6 and the passivation film 7, but are exposed from these insulating films.
Furthermore, the input wiring 8 of the driver LSI 3 formed of the same metal layer as the source wiring row 4a is disposed at the outermost end on the peripheral edge of the electrode substrate 1. One end of the input wiring 8 is provided with an LSI electrode 8a for connection to a plurality of input bumps 3a of the driver LSI 3, and the other end is supplied with a drive signal and power from the external circuit board to the driver LSI 3. An FPC electrode 8b connected to an FPC (flexible wiring board) 9 is formed.

FIG. 3 is a partial cross-sectional view illustrating a method for mounting a driver LSI in the liquid crystal display device according to Embodiment 1 of the present invention.
In FIG. 3, 1 to 9b are the same as those in FIG. The ACF 10 is composed of conductive particles 10a and an epoxy resin 10b, and is affixed on the electrode terminal. The insulating resin 11 is provided so as to prevent corrosion of the wiring portion between the driver LSI 3 and the FPC 9.
FIG. 4 is a plan view showing the FPC and circuit board of the liquid crystal display device according to Embodiment 1 of the present invention.
In FIG. 4, the FPC 9 is provided with a monitor wiring 9d connected to the cross wiring electrode and a measurement pad 9e. The circuit board 19 connected to the FPC 9 has a circuit wiring 19a connected to the monitor wiring 9d and a measurement. A pad 19b and an interface connector 19c are provided.

FIG. 5 is a three-dimensional view showing a method of assembling the liquid crystal display device according to Embodiment 1 of the present invention.
In FIG. 5, a front frame 21 and a backlight 22 are arranged with the driver LSI mounted liquid crystal panel 20 interposed therebetween, and the driver LSI mounted liquid crystal panel 20 and the circuit board 19 are connected by the FPC 9.
FIG. 6 is a partial cross-sectional view for explaining an inspection method when a display defect occurs in the liquid crystal display device according to Embodiment 1 of the present invention.
In FIG. 6, the laser 13 is irradiated to the intersection 12 between the source wiring 4 and the cross wiring 5.

FIG. 7 is a partial plan view for explaining an inspection method when a display defect occurs in the liquid crystal display device according to Embodiment 1 of the present invention.
In FIG. 7, an address number 15 is assigned to an intersection 12 between the source wiring 4 and the cross wiring 5.
FIG. 8 is a partial plan view for explaining an inspection method when a plurality of display defects occur in the liquid crystal display device according to Embodiment 1 of the present invention.
In FIG. 8, source wirings 400, 401, 402, 403 and source electrode terminals 400b, 401b, 402b, 403b forming the short-circuit portions 14a, 14b are shown.

Next, among the method for manufacturing the liquid crystal display device in the first embodiment, a method for manufacturing an electrode substrate will be described.
First, a metal film such as Cr, Al, Ta, Ti, and Mo is formed on a transparent insulating substrate such as glass (for example, trade name AN635) by sputtering, patterned by photolithography, and cross wiring 5 and cross wiring The electrodes 5b and 5c, the gate electrode and gate terminal electrode of the display portion, the electrode terminal for capturing an external input signal, and the like are formed simultaneously. Next, for example, SiN is formed using plasma CVD to form a gate insulating film. Subsequently, a-Si serving as a channel layer and N + type a-Si serving as a contact layer are successively formed on the gate electrode and the gate insulating film, and then patterned to drive each liquid crystal display element in the display portion. A thin film transistor is formed.

Further, after forming a metal film such as Cr, Al, and Mo by sputtering, patterning is performed, and the drain electrode of the display portion, the source wiring 4 and the source electrode terminal 4b, the source wiring row 4a of the electrode terminal portion, and the external input signal Are simultaneously formed. Subsequently, ITO is formed by sputtering and then patterned to form pixel electrodes. At the same time, ITO is formed on the gate electrode, the source electrode terminal 4b of the electrode terminal portion, and the LSI electrode 8a and the FPC electrode 8b portion of the input wiring 8, and the electrode terminal formed of a wiring material such as Cr or Al is exposed. By doing so, an oxide film is formed and conduction failure with the ACF 10 is prevented.
Finally, in order to prevent a DC component from entering the liquid crystal layer, a passivation film 7 is formed by depositing SiN or the like by plasma CVD. Thereafter, the passivation film 7 is removed from the gate electrode, the source electrode terminal 4b, the LSI electrode 8a of the input wiring 8, and the FPC electrode 8b, thereby exposing the ITO. Thereby, the electrode substrate 1 in Embodiment 1 is completed.
Note that the description of the manufacturing method of the counter substrate 2 and the assembly process of injecting the liquid crystal by overlapping and bonding the electrode substrate 1 and the counter substrate 2 are omitted here.

Next, a method for mounting the driver LSI 3 will be described with reference to FIG.
First, the ACF 10 is affixed on the electrode terminal formed on the peripheral edge of the electrode substrate 1 surface. Next, after aligning the plurality of bump electrodes made of Au formed on the back surface of the driver LSI 3 and the electrode terminals of the electrode substrate 1 with high precision, thermocompression bonding is performed using a heating and pressing tool. The conditions at this time are a heating temperature of 170 to 200 ° C., a time of 10 to 20 seconds, and a pressure of 30 to 100 Pa. As a result, the conductive particles 10a of the ACF 10 sandwiched between the bump electrodes of the driver LSI 3 and the electrode terminals of the electrode substrate 1 conduct only in the vertical direction. That is, the input bump 3a and the LSI electrode 8a, and the output bump 3b and the source electrode terminal 4b are electrically connected. In the horizontal direction, insulation is maintained because the insulating epoxy resin 10b exists around the conductive particles 10a.

  Subsequently, the connection between the FPC 9 and the FPC electrode 8b is similarly performed using the ACF 10. The FPC 9 is composed of a polyimide film having a thickness of about 30 to 70 μm, a copper foil 9b having a thickness of 8 to 25 μm, and a polyimide solder resist, and is connected to the cross wiring electrodes 5b and 5c as shown in FIG. It has a monitor wiring 9d and a measurement pad 9e. Finally, insulative resin 11 is applied to prevent corrosion of the wiring portion between driver LSI 3 and FPC 9. As the insulating resin 11, silicone resin, acrylic resin, fluororesin, urethane resin or the like is mainly used, and is applied using a dispenser.

Next, a method for assembling the liquid crystal display device will be briefly described with reference to FIG.
The above-described driver LSI-equipped liquid crystal panel 20 is mounted on a backlight 22 serving as a planar light source, the front frame 21 is fitted from the front surface of the driver LSI-equipped liquid crystal panel 20, and the circuit board 19 is connected to the monitor wiring 9 d of the FPC 9. The circuit board 19 includes a circuit wiring 19a connected to the FCP monitor wiring 9d, and includes an interface connector 19c which is an output terminal for outputting signals from the measurement pad 19b and the circuit wiring 19a to the outside.

Next, an inspection method when a display defect occurs in the liquid crystal display device according to Embodiment 1 will be described with reference to FIGS.
With respect to the liquid crystal display panel after the driver LSI 3 and the FPC 9 are mounted, signals are sequentially input from the signal generator to the respective source wirings 4, where a predetermined video signal cannot be obtained on the display unit, that is, there is a display defect such as a line defect. The generated address is specified by the address generation function of the signal generator.
Next, as shown in FIG. 6, the YAG laser 13 is irradiated from the back surface side of the electrode substrate 1, that is, the glass substrate side, to the intersection 12 between the source wiring 4 and the cross wiring 5 corresponding to the address. The gate insulating film 6 is pierced by the heat of the laser 13, and the source wiring 4 and the cross wiring 5 are short-circuited to be electrically connected. At this time, in order to ensure reliable conduction, it is desirable to divide the laser irradiation into several times.

In addition, as shown in FIG. 7, it is also effective to secure a sufficient irradiation area by forming the wiring width of the intersection 12 of the source wiring 4 and the cross wiring 5 wider than the other portions. Further, the address number 15 of each source wiring 4 may be written in the immediate vicinity of the intersection 12 in order to easily determine the laser irradiation part. The address number 15 can be formed using a source wiring material, a gate wiring material, a-Si, or the like. Instead of the address number 15, it may be written as a dot or a symbol.
The cross wiring 5 is connected to the monitor wiring 9d of the FPC 9 and the circuit wiring 19a of the circuit board 19, and a probe and a needle connected to a measuring instrument such as an oscilloscope and a digital multimeter are brought into contact with the measurement pads 9e and 19b. The output waveform from the output bump 3b of the driver LSI 3 connected to the source electrode terminal 4b of the source wiring 4 that is a defect occurrence location is used to measure the FPC 9 or the circuit board 19 via the cross wiring 5 and the FPC 9 and the circuit board 19. Measurement is made with the pads 9e and 19b to find out the cause of the defect.

  Specifically, the lighting inspection is performed again with the probe and the needle connected to the measurement device such as the oscilloscope and the digital multimeter in contact with the measurement pads 9e and 19b of the FPC 9 or the circuit board 19, and the oscilloscope Based on the output waveform displayed and the voltage value displayed on the digital multimeter, whether the cause of the failure is an abnormality on the driver LSI 3 side, disconnection of the wiring formed on the electrode substrate 1 or abnormality of the TFT, etc. Identify.

In the first embodiment, the cross wiring electrodes 5b and 5c are provided on both sides of the cross wiring 5, but only one side may be provided. However, it is desirable that the cross wiring electrodes connected to the FPC of the cross wiring 5 are provided at a plurality of locations in case a plurality of display defects occur.
For example, an inspection method when two display defects occur will be described with reference to FIG. As shown in FIG. 8, when a line defect occurs in the two source wirings 400 and 403, on the cross wiring 5 between the source wiring 400 and the source wiring 403 and the other source wirings 401 and 402 and the cross wiring 5. A portion other than the crossing portion with, for example, a portion indicated by X in FIG. As a result, the cross wiring 5 is divided into two, and the cross wiring electrodes 5b and 5c are provided at the respective end portions.
Subsequently, the YAG laser 13 is irradiated from the glass substrate side to the intersections of the source wirings 400 and 403 and the cross wiring 5, that is, the intersections 14a and 14b of the address number 15 of 100 and 103, and the gate insulating film 6 is applied. A hole to be pierced is formed, and the source wirings 400 and 403 and the cross wiring 5 are short-circuited, respectively.

  Thereafter, a lighting inspection was performed in a state where probes and needles connected to measurement devices such as an oscilloscope and a digital multimeter were in contact with the measurement pads 9e and 19b of the FPC 9 or the circuit board 19 and connected to the source electrode 4. The output waveform displayed on the oscilloscope from the output bump 3b of the driver LSI 3 and the voltage value displayed on the digital multimeter are observed to identify the cause of the failure.

A plurality of cross wirings 5 may be formed in preparation for further disconnection.
Alternatively, the cross wiring 5 may be branched in the middle, and the cross wiring electrodes 5b and 5c may be provided at the respective tip portions.
Further, the cross wiring electrodes 5 b and 5 c may be provided at a place other than the tip of the cross wiring 5.
Furthermore, even if the cross wiring 5 is not a straight line, its effectiveness is not reduced.
In the first embodiment, the cross wiring 5 is formed between the input bump row of the driver LSI 3 and the terminal row of the output bump row in order to cope with the narrow frame of the liquid crystal display device. Any position may be used as long as it intersects the wiring row. For example, it may be formed between the driver LSI 3 and the end of the counter substrate 2.

As described above, according to the first embodiment, in the liquid crystal display device adopting the COG method, the source wiring row 4a and the gate insulating film 6 are crossed on the peripheral portion of the electrode substrate surface 1, and the both sides thereof are arranged. The cross wiring electrodes 5b and 5c connected to the FPC are arranged at the tip and connected to the FPC 9 and the measurement pads 9e and 19b of the circuit board 19, so that a line defect or the like is detected in the lighting inspection after the driver LSI 3 is mounted. When a display failure occurs, the YAG laser 13 is irradiated from the back side of the substrate to the intersection 12 between the source wiring 4 and the cross wiring 5 where the failure occurs, and the source wiring 4 and the cross wiring 5 are connected to each other. 19 probes 9e and 19b are brought into contact with probes and needles connected to measuring instruments such as oscilloscopes and digital multimeters. It is possible to measure the output waveform and the output voltage from the driver LSI3 flowing over a source wiring of a place.
As a result, the cause of the display failure can be easily determined, and a liquid crystal display device with high productivity and low cost can be obtained.
Since the cross wiring 5 can be formed at the same time as the gate wiring, by arranging the cross wiring 5 between the input bump row and the output bump row of the driver LSI 3, a place where the cross wiring 5 is arranged is newly provided. Since it is not necessary to ensure, it can respond to the narrow frame of a liquid crystal display device.

Embodiment 2. FIG.
Next, an example in which cross wiring is applied to a liquid crystal display device in which a plurality of subordinately connected driver LSIs 3 are mounted on one side on the peripheral edge of the electrode substrate will be described.
FIG. 9 is a plan view showing the source-side electrode terminal portion of the liquid crystal display device according to Embodiment 2 of the present invention.
9, 1, 2, 5b, 5c, 8, 8a, and 8b are the same as those in FIG. In FIG. 9, two subordinately connected driver LSIs indicated by a dotted line in the drawing, that is, a first driver LSI 31 and a second driver LSI 32 are mounted on one side on the peripheral edge of the surface of the electrode substrate 1. Among them, the first driver LSI 31 located at the extreme end is supplied with a drive signal and power from the external circuit board via the FPC 9. The electrode substrate 1 corresponding to the long side portion of the first driver LSI 31 is provided with the power supply power supply electrode row 3c, the electrode substrate 1 corresponding to one short side portion is provided with the input signal line input electrode row 3d, and the other side. An output electrode array 3e for outputting an input signal to the second driver LSI 32 is disposed on the electrode substrate 1 corresponding to the short side portion, and a second driver LSI 32 that is subordinately connected to the first driver LSI 31. The electrode substrate 1 corresponding to is provided with an input electrode array 3f for inputting an input signal, and these input electrode array and output electrode array are used as input bumps and output bumps of the first and second driver LSIs. Each is joined.
In FIG. 9, a connection wiring row 16 a including a plurality of connection wirings 16 for connecting the output electrode row of the first driver LSI 31 and the input electrode row of the second driver LSI 32 is provided on the peripheral portion of the electrode substrate surface. Has been placed. The connection wiring row 16 a is formed of the same material as that of the source wiring 4. Further, a cross wiring 5 is disposed between the output electrode array 3 e of the first driver LSI 31 and the input electrode array 3 f of the second driver LSI 32.

The cross wiring 5 is formed of a metal layer different from that of the connection wiring row 16a. In the second embodiment, the cross wiring 5 is formed of the same material as the gate wiring. Therefore, the cross wiring 5 intersects with the connection wiring row 16a via the gate insulating film 6, and cross wiring electrodes 5b and 5c for FPC connection are provided at the tip portions on both sides thereof. The cross wiring electrodes 5b and 5c are not covered with the gate insulating film 6 and the passivation film 7, but are exposed from these insulating films.
In addition, the wiring width at the intersection of the cross wiring 5 and the connection wiring row 16a is formed wider than the wiring width of the other portions.

Furthermore, a number, a symbol, or a signal name indicating the address of each connection wiring 16 of the connection wiring row 16a may be written near the intersection of the connection wiring row 16a and the cross wiring 5.
Note that the method for forming the electrode substrate 1, the method for mounting the driver LSI 3, and the method for assembling the liquid crystal display device in the second embodiment are the same as those in the first embodiment, and thus the description thereof is omitted.

Next, an inspection method when a display defect occurs in the liquid crystal display device according to the second embodiment will be briefly described.
In the lighting inspection after mounting the first driver LSI 31, the second driver LSI 32, and the FPC, when a display defect such as a line defect occurs, particularly when a display defect occurs in all the blocks of the second driver LSI 32, it relates to the defect occurrence location. The connection wiring 16 that connects the output electrode array 3e of the first driver LSI 31 to the input electrode array 3f of the second driver LSI 32 is specified.
Next, the YAG laser 13 is irradiated from the glass substrate side on the back surface of the electrode substrate to the intersection between the connection wiring 16 and the cross wiring 5 to connect the connection wiring 16 and the cross wiring 5. Thereafter, the probe LSI and the needle connected to the measurement device such as an oscilloscope and a digital multimeter are brought into contact with the measurement pads 9e and 19b on the FPC 9 and the circuit board 19, thereby causing the driver LSI 3 to flow on the connection wiring at the failure occurrence location. The cause of the failure is identified from the output waveform and output voltage from.

  Thus, according to the second embodiment, a plurality of driver LSIs are cascade-connected, and it is possible to easily detect a defect in the connection wiring that connects these driver LSIs.

Embodiment 3 FIG.
Next, an example in which a connection between a plurality of parallel cross wirings is applied to the liquid crystal display device according to the first embodiment will be described.
10 is a plan view showing a source-side electrode terminal portion of a liquid crystal display device according to Embodiment 3 of the present invention.
10, 1-5, 2a, 4a-4c, 5b, 5c, 8, 8a, 8b are the same as those in FIG. In FIG. 10, the cross wiring 5 a is provided in parallel to the cross wiring 5.
FIG. 11 is a partial cross-sectional view showing an electrode terminal portion of a liquid crystal display device according to Embodiment 3 of the present invention, and is a partial cross-sectional view cut along BB in FIG.
In FIG. 11, 1-9, 2a, 3a, 3b, 4b, 8a, 8b, 9b are the same as those in FIG. A cross wiring 5a is provided.

FIG. 12 is a partial plan view for explaining an inspection method when a plurality of display defects occur in the liquid crystal display device according to Embodiment 3 of the present invention.
12, 5, 14a, 14b, 15, 400, 401, 402, 403, 400b, 401b, 402b, and 403b are the same as those in FIG. In FIG. 12, a cross wiring 5 and a cross wiring 5a arranged in parallel are provided. Intersections 12a (first intersection) and 12c (second intersection) of the cross wirings 5, 5a and the source wiring are provided. ) And crossing short-circuit portions 14c and 14d are arranged.
The liquid crystal display device according to the third embodiment is almost the same as that of the first embodiment, and the difference is that there are a plurality of parallel cross wirings 5 and 5a and the cross wirings are connected to each other.

In the third embodiment, one of the two cross wirings 5 and 5a is arranged between the LSI electrode 8a row and the source electrode terminal 4b row of the driver LSI 3, and the other cross wiring 5a is arranged in parallel. Are arranged between the output bump row of the driver LSI 3 and the liquid crystal display element, and the cross wirings are connected to each other.
The cross wirings 5 and 5 a are formed of the same material as the gate wiring, and intersect the source wiring row 4 a via the gate insulating film 6. The cross wirings 5 and 5a are provided with FPC connecting cross wiring electrodes 5b and 5c at the tip portions on both sides thereof. The cross wiring electrodes 5b and 5c are not covered with the gate insulating film 6 and the passivation film 7, but are exposed from these insulating films.

An input wiring 8 of the driver LSI 3 formed of the same metal layer as that of the source wiring row 4a is disposed at the outermost end on the peripheral edge of the electrode substrate 1. One end of the input wiring 8 is provided with an LSI electrode 8a for connection to a plurality of input bumps 3a of the driver LSI, and the other end is supplied with drive signals and power from the external circuit board to the driver LSI 3. FPC electrodes 8b for connecting to an FPC 9 (flexible wiring board) for the purpose are formed.
As shown in FIG. 12, the wiring width at the intersection between the cross wirings 5 and 5a and the source wiring 4 is formed wider than the wiring width of the other portions.

Furthermore, a number or a symbol indicating an address may be written in the vicinity of the intersection between the source wiring 4 and the cross wirings 5 and 5a.
The method for forming the electrode substrate, the method for mounting the driver LSI 3 and the method for assembling the liquid crystal display device in the third embodiment are the same as those in the first embodiment, and thus the description thereof is omitted.

Next, an inspection method when a display defect occurs in the liquid crystal display device according to the third embodiment will be described with reference to FIG.
With respect to the liquid crystal display panel after the driver LSI 3 and the FPC 9 are mounted, signals are sequentially input from the signal generator to the respective source wirings 4, where a predetermined video signal cannot be obtained on the display unit, that is, there is a display defect such as a line defect. The generated address 100 is specified by the address generation function of the signal generator. By irradiating the YAG laser from the back side of the electrode substrate, that is, the glass substrate side, to the intersection 12 a between the source wiring 400 corresponding to the address 100 and the cross wiring 5, the short circuit portion 14 a is formed. The wiring 5 is electrically connected. At this time, it is desirable to divide the laser irradiation into several times in order to ensure reliable conduction. Subsequently, the source wiring 400 corresponding to the address 100 is irradiated with a YAG laser from the back side of the electrode substrate 1 at a position indicated by Z between the source electrode terminal 400b and the intersecting portion 12c, and is melted and cut.

Further, a probe and a needle connected to a measuring device such as an oscilloscope and a digital multimeter are brought into contact with the FPC 9 connected to the cross wiring 5 and the measurement pads 9e and 19b on the circuit board 19 to indicate a defect occurrence point. The output waveform from the output bump 3 a of the driver LSI 3 connected to the source electrode terminal 400 b of the source wiring 400 is sent from the measurement pads 9 e and 19 b of the FPC 9 or the circuit board 19 through the cross wirings 5, 5 a and the FPC 9 and the control board 19. taking measurement.
Thereby, it is possible to easily determine whether the cause of the display failure is on the driver LSI 3 side, or on the wiring or switching element portion formed on the substrate.
Finally, the source wiring 4 is cut and needs to be repaired. As a repair method, a YAG laser is applied to the back surface of the electrode substrate at the intersection 12c between the source wiring 400 corresponding to the address 100 and the cross wiring 5a disposed between the output bump row of the driver LSI 3 and the liquid crystal display element. By irradiating from the side, as shown in FIG. 12, a short circuit portion 14c is formed, and the source wiring 400 and the cross wiring 5a are short-circuited and electrically connected. As a result, the output of the driver LSI can be transmitted to the liquid crystal display element via the cross wirings 5 and 5a.

Specifically, the driver LSI 3 and the electrode substrate 1 are separated, and the probe and the needle connected to the measurement device such as an oscilloscope and a digital multimeter are in contact with the measurement pads 9e and 19b of the FPC 9 or the circuit board 19. A lighting inspection is performed again, and the cause of the failure is an abnormality on the driver LSI 3 side based on the output waveform displayed on the oscilloscope and the voltage value displayed on the digital multimeter, or the wiring formed on the electrode substrate 1 is disconnected. Alternatively, it is completely specified whether the TFT is abnormal.
Although the case where there is one display defect address has been described, when there are two defect addresses, the YAG laser is irradiated from the back side of the electrode substrate at the X and Y positions in FIG. If the wiring 5a is blown and cut, the cause of the failure can be similarly identified.

  According to the third embodiment, a plurality of cross wirings are provided, and it is completely specified whether the cause of the failure is an abnormality on the driver LSI side, a disconnection of the wiring formed on the electrode substrate, or an abnormality of the TFT. can do.

In the above description of the third embodiment, the cross wirings are connected to each other. However, a plurality of cross wirings are provided independently, and the monitor wirings 9d of the FPCs 9 connected to the cross wirings are connected to each other. The same effect can be obtained by connecting the circuit wirings 19a of the circuit board 19 respectively connected to the monitor wiring 9a.
In the first to third embodiments, the source side electrode terminal portion has been described as an example. However, the present invention is also applicable to the gate side electrode terminal portion. In that case, the cross wiring may be formed of the same metal film as the source wiring and disposed so as to cross the gate wiring row through the gate insulating film.

It is a top view which shows the electrode terminal part of the liquid crystal display device by Embodiment 1 of this invention. It is a fragmentary sectional view which shows the electrode terminal part of the liquid crystal display device by Embodiment 1 of this invention. It is a fragmentary sectional view explaining the method for mounting the driver LSI in the liquid crystal display device according to the first embodiment of the present invention. It is a top view which shows FPC and a circuit board of the liquid crystal display device by Embodiment 1, 2, 3 of this invention. It is a three-dimensional view showing an assembly method of a liquid crystal display device according to the first, second and third embodiments of the present invention. It is a fragmentary sectional view explaining the inspection method when the display defect generate | occur | produces in the liquid crystal display device by Embodiment 1 of this invention. It is a partial top view explaining the test | inspection method when the display defect generate | occur | produces in the liquid crystal display device by Embodiment 1 of this invention. It is a fragmentary top view explaining the test | inspection method when the some display defect generate | occur | produces in the liquid crystal display device by Embodiment 1 of this invention. It is a top view which shows the source side electrode terminal part of the liquid crystal display device by Embodiment 2 of this invention. It is a top view which shows the source side electrode terminal part of the liquid crystal display device by Embodiment 3 of this invention. It is a fragmentary sectional view which shows the electrode terminal part of the liquid crystal display device by Embodiment 3 of this invention. It is a fragmentary top view explaining the test | inspection method when the some display defect generate | occur | produces in the liquid crystal display device by Embodiment 3 of this invention.

Explanation of symbols

1 electrode substrate, 2a end, 2 counter substrate, 3 driver LSI,
3a Input bump, 3b Output bump, 3c Power supply system electrode array,
3d input electrode array, 3e output electrode array, 3f input electrode array, 4 source wiring,
4a source wiring line, 4b source electrode terminal,
4c source electrode terminal block, 5, 5a cross wiring,
5b, 5c Cross wiring electrode, 6 Gate insulating film, 7 Passivation film,
8 input wiring, 8a LSI electrode, 8b FPC electrode, 9 FPC,
9b Copper foil, 9d Monitor wiring, 9e Measurement pad, 10 ACF,
10a conductive particles, 10b epoxy resin, 11 insulating resin,
12, 12a, 12c intersection, 13 laser,
14, 14a, 14b, 14c, 14d Short-circuit part, 15 Address number,
16 connection wiring, 16a connection wiring row, 19 circuit board, 19a circuit wiring,
19b measurement pad, 19c interface connector,
20 LCD panel with driver LSI, 21 front frame,
22 backlight, 31 first driver LSI,
32 second driver LSI, 400, 401, 402, 403 source wiring,
400b, 401b, 402b, 403b Source electrode terminals.

Claims (19)

In a liquid crystal display device having a display unit in which a liquid crystal layer is sandwiched between an electrode substrate and a counter substrate disposed so as to face the electrode substrate, output wiring electrode terminals disposed on a peripheral portion of the electrode substrate A plurality of output wirings each for supplying a driving signal to the display unit; a cross wiring arranged to cross the plurality of output wirings via an insulating film and having a cross wiring electrode; and the output wiring electrode terminal to be arranged on the periphery of the electrode substrate while have a plurality of output bumps coupled respectively, it said output drive IC outputs a drive signal to the wiring, and the cross-wired monitor lines to cross line electrodes And a flexible wiring board having a measurement pad connected to the monitor wiring,
A liquid crystal display device, wherein a probe connected to a measuring device is brought into contact with a measuring pad of the flexible wiring board.   2. The liquid crystal display device according to claim 1, wherein the cross wiring is formed so that a wiring width at an intersection with the output wiring is wider than other portions.   3. The liquid crystal display device according to claim 1, wherein the output wiring is formed so that a wiring width at a crossing portion with the cross wiring is wider than other portions.   4. The liquid crystal display device according to claim 1, wherein an address of the output wiring is expressed near an intersection of the output wiring and the cross wiring. 5.   The driving IC has a plurality of input bumps to which an input signal is input, and the cross wiring is disposed between the plurality of output bumps and the plurality of input bumps of the driving IC. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a liquid crystal display device. In a liquid crystal display device having a display unit in which a liquid crystal layer is sandwiched between an electrode substrate and a counter substrate arranged to face the electrode substrate, the display unit is driven based on an input signal input from the outside. And two driving ICs connected in cascade via a plurality of output electrodes formed on the peripheral edge of the electrode substrate and a plurality of input electrodes respectively connected to the plurality of output electrodes, the two driving ICs A plurality of connection wirings on the electrode substrate for connecting the plurality of output electrodes to the plurality of input electrodes, and a cross having the cross wiring electrodes arranged so as to cross the plurality of connection wirings through an insulating film A flexible wiring board having wiring, a monitor wiring connected to the cross wiring electrode of the cross wiring, and a measurement pad connected to the monitor wiring;
A liquid crystal display device, wherein a probe connected to a measuring device is brought into contact with a measuring pad of the flexible wiring board.   7. The liquid crystal display device according to claim 6, wherein the cross wiring is formed so that a wiring width at a crossing portion with the connection wiring is wider than other portions.   8. The liquid crystal display device according to claim 6, wherein the connection wiring is formed so that a wiring width at an intersection with the cross wiring is wider than other portions.   9. The liquid crystal display device according to claim 6, wherein an address of the connection wiring is expressed near an intersection of the connection wiring and the cross wiring.   The liquid crystal display device according to claim 6, wherein the cross wiring is disposed between the plurality of output electrodes and the plurality of input electrodes.   11. The liquid crystal display device according to claim 1, wherein the cross wiring electrode is formed at one end of the cross wiring.   The liquid crystal display device according to any one of claims 1 to 11, wherein a plurality of the cross wirings are arranged, and the plurality of cross wirings are connected to each other.   The plurality of cross wirings are arranged, and a plurality of monitor wirings of the flexible wiring board are provided so as to be connected to the plurality of cross wirings, respectively, and the plurality of monitor wirings are connected to each other. The liquid crystal display device according to claim 1.   A circuit board having a circuit wiring connected to the monitor wiring of the flexible wiring board and a measurement pad connected to the circuit wiring; a plurality of the cross wirings are arranged; and the monitor wiring of the flexible wiring board is a plurality of the monitoring wirings A plurality of circuit wirings are provided so as to be connected to the respective cross wirings, and a plurality of circuit wirings of the circuit board are provided to be connected to the plurality of monitor wirings, respectively, and the plurality of circuit wirings are connected to each other. The liquid crystal display device according to any one of claims 1 to 11.   14. The liquid crystal according to claim 1, further comprising a circuit board having a circuit wiring connected to a monitor wiring of the flexible wiring board and a measurement pad connected to the circuit wiring. Display device.   16. The liquid crystal display device according to claim 14, wherein the circuit board has an interface connector to which the circuit wiring is connected to the outside when connected to the flexible wiring board.   A display unit in which a liquid crystal layer is sandwiched between an electrode substrate provided with a plurality of output wirings and a counter substrate disposed to face the electrode substrate, and the output disposed on the peripheral portion of the electrode substrate. In the inspection method of a liquid crystal display device for specifying the cause when a display failure occurs in a liquid crystal display device driven by a driving IC bonded to an output wiring electrode terminal of the wiring, the output wiring related to the occurrence of the display failure Irradiating a laser from the back side of the electrode substrate to the intersection where the cross wiring arranged to cross the plurality of output wirings and the output wiring of the specified address intersect, A step of connecting the output wiring of the specified address and the cross wiring, and a measurement pad provided on the flexible wiring board connected to the cross wiring or the flexible wiring board; A probe connected to a measurement device is brought into contact with a measurement pad provided on a circuit board connected to a sibling wiring board, and an output waveform and an output voltage from the driving IC flowing on the output wiring of the specified address are obtained. A method for inspecting a liquid crystal display device, comprising a step of measuring. A display unit in which a liquid crystal layer is sandwiched between an electrode substrate in which a plurality of driving ICs that are subordinately connected by a plurality of connection wirings are arranged at a peripheral portion and a counter substrate that is arranged to face the electrode substrate In the liquid crystal display device inspection method for specifying the cause when a display failure occurs in the liquid crystal display device driven by the plurality of driving ICs, the step of specifying the address of the connection wiring related to the occurrence of the display failure Then, a laser beam is irradiated from the back side of the electrode substrate to the crossing portion where the cross wiring arranged so as to cross the plurality of connection wirings and the connection wiring of the specified address intersect, and the specified address A step of connecting the connection wiring and the cross wiring, and a measurement pad provided on the flexible wiring board connected to the cross wiring or the flexible wiring board. A step of contacting a probe connected to a measurement device with a measurement pad provided on the circuit board, and measuring an output waveform and an output voltage from the drive IC flowing on the connection wiring of the specified address. An inspection method for a liquid crystal display device.   A display unit in which a liquid crystal layer is sandwiched between an electrode substrate provided with a plurality of output wirings and a counter substrate disposed to face the electrode substrate, and the output disposed on the peripheral portion of the electrode substrate. In the inspection method of a liquid crystal display device for specifying the cause when a display failure occurs in a liquid crystal display device driven by a driving IC bonded to an output wiring electrode terminal of the wiring, the output wiring related to the occurrence of the display failure The step of specifying the address of the first crossing the one of the plurality of cross wirings arranged to cross the plurality of output wirings and the output wiring of the specified address crossing each other A step of irradiating a laser beam from the back side of the electrode substrate to the crossing portion to connect the output wiring of the specified address of the first crossing portion and the cross wiring, and forming the first crossing portion The output wiring between the second intersection and the first intersection where the output wiring of the specified address intersects another cross wiring arranged on the center side of the electrode substrate from the loss wiring. A step of irradiating and cutting a laser from the back side of the electrode substrate, a measurement pad provided on a flexible wiring substrate connected to the cross wiring, or a measurement pad provided on a circuit substrate connected to the flexible wiring substrate A step of contacting a probe connected to a measuring device and measuring an output waveform and an output voltage from the driving IC flowing on the output wiring of the specified address, and the electrode substrate at the second intersection And a step of irradiating a laser from the back side of the second cross section to connect the output wiring of the specified address at the second intersection and the cross wiring. Inspection method of a display device.

Images