JP2002268081A - Manufacturing method of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably form a black spot without protruding an interlayer insulating film due to laser irradiation at the time of rescue of a liquid crystal display device and protruding an electrode (wiring) metal cut or contacted. I do. SOLUTION: An ultraviolet light laser having a wavelength of 355 nm is irradiated from the front side of a TFT array substrate to thereby cut and contact an interlayer insulating film 1.
5 is removed (FIG. 1 (a) -2, FIG. 1 (b) -2). Wavelength 10
By irradiating a laser beam of 64 nm from the front side of the TFT array substrate, the extraction portion 6a of the source electrode 6 is reliably cut (FIG. 1 (a) -3). Wavelength is 1064nm
The drain electrode 7 and the gate wiring 1 are brought into contact by irradiating the laser beam as described above from the back side of the TFT array substrate (FIG. 1 (b) -3).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method of manufacturing a liquid crystal display device for driving liquid crystal using a TFT array substrate on which a plurality of transistors are formed.

[0002]

2. Description of the Related Art In a reflection type liquid crystal display device, in order to display by reflection of external light, it is necessary to increase the reflectance so as to reflect incident external light as efficiently as possible.

As means for increasing the reflectivity, prevention of light propagation loss in a liquid crystal cell or an optical member and increase in the reflectivity of a reflector can be mentioned. As a method of reducing light propagation loss due to a liquid crystal cell or an optical member, a guest-host type display method without using a polarizing plate (Japanese Patent Laid-Open No. 7-146469) is focused on the fact that light transmission loss through a polarizing plate is the largest. Publication) and a single polarizing plate system in which one polarizing plate is used (Japanese Patent Laid-Open No.
No. 84252).

Further, as a method of increasing the reflectance at the reflector, a reflector is conventionally provided outside the liquid crystal cell, the reflector is provided inside the liquid crystal cell, and as a constituent material of the reflector, the reflectance is high and the electric resistance value is high. A method of forming a reflection electrode having both a function as a reflection plate and a function as an electrode using aluminum having a low thickness (Japanese Patent Laid-Open No. 8-101384) is disclosed.

Further, a method of providing a display using a liquid crystal cell having a light scattering function, a phase plate and a polarizing plate by providing irregularities on the surface of the reflective electrode (JP-A-5-217701), and Forming by melt method
No. 146087).

FIG. 3 shows a schematic cross section of an example of a conventional reflection type liquid crystal display device. This reflection type liquid crystal display device has a TFT array substrate in which a thin film transistor (hereinafter, referred to as a TFT) 24, an interlayer insulating film 15, a reflection electrode 11 and the like are formed on one glass substrate 12, and a glass substrate 12 on the other glass substrate. A liquid crystal layer 23 is sandwiched between a color filter 21 and a counter substrate on which a transparent electrode 22 is formed, and a retardation plate 25 and a polarizing plate 20 are provided outside the counter substrate.

This reflection type liquid crystal display device uses a combination of a single polarizing plate system in which a single polarizing plate 20 is provided and a system in which an uneven reflecting electrode 11 is provided in a liquid crystal cell. The surface is made to have a shape in which irregularities are regularly arranged, thereby imparting scattering properties to increase diffuse reflectance and improve visibility. The reflective electrode 11 is formed on the uneven interlayer insulating film 15, and passes through the drain contact hole 9 provided in the interlayer insulating film 15 to form a TFT.
24 and is electrically connected to the drain electrode 7. A voltage is applied to the uneven reflective electrode 11 by the switching operation of the TFT 24. The reflection electrode 11 acts as a pixel electrode to apply a voltage to the liquid crystal layer 23.

In general, in order to improve the yield of the manufacturing process on the TFT array substrate, a portion that becomes an image defect such as a point defect caused by a pattern defect portion on the TFT array substrate is removed after the manufacturing process of the TFT array substrate is completed. During the manufacturing process, pattern processing is performed by laser irradiation or the like to reduce defects.
Called rescue. ). Among these, a black spot processing is performed to process a pattern defect to be a bright spot and to make it visually inconspicuous.

[0009]

In a liquid crystal display device, in particular, a reflection type liquid crystal display device, a photosensitive acrylic resin is often used for the interlayer insulating film 15. In an array structure with this acrylic resin, an array pattern defect to be a bright spot occurs, and after the TFT array substrate is manufactured, when this portion is turned into a black spot, the acrylic resin or metal electrode is irradiated by laser irradiation. After scattering, the TFT array substrate and the opposing substrate are bonded to each other, and short-circuits with the transparent electrode 22 of the opposing substrate, so that normal display cannot be performed. This causes a problem in reliability. Less than,
This will be described in detail with reference to FIGS.

In FIG. 4, (a) is a plan view of a pixel on a TFT array substrate of a reflection type liquid crystal display device, and (b) is (a).
The cross-sectional view taken along the line AB or A'-B 'in FIG. 3C is a cross-sectional view taken along the line CD in FIG. 4, reference numeral 1 denotes a gate wiring, 2 denotes a common capacitance wiring, 3 denotes a source wiring, and 4 denotes an insulating film for preventing the source wiring 3 from causing a short circuit on the gate wiring 1 or the common capacitance wiring 2. ,
Reference numerals 6 and 7 denote a channel layer and a source electrode and a drain electrode of the TFT respectively; 8 a common capacitance electrode; 10 is a contact hole for connecting the common capacitance electrode 8 and the reflection electrode 11 to have the same potential (hereinafter referred to as a common capacitance electrode contact hole), and 11 has a function of a reflector. A reflective electrode which is a pixel electrode, 12 is a glass substrate, 13 is a gate insulating film, 14 is a contact layer for making ohmic contact between the source or drain electrode 6 and the channel layer 5, and 15 is a photosensitive acrylic resin Is an insulating film for preventing the leading portion 8a of the common capacitance electrode 8 from short-circuiting with the common capacitance wiring 2. Parts corresponding to those in FIG. 3 are denoted by the same reference numerals and are not shown in FIG.
3, the surface of the interlayer insulating film 15 is irregularly uneven as shown in FIG. 3, and the reflective electrode 11 is also formed unevenly along the surface.

The TFT array substrate is a glass substrate 12
A plurality of gate wirings 1 and source wirings 3 are arranged on the upper side so as to intersect with each other, TFTs are arranged at intersections of the gate wirings 1 and the source wirings 3, and each pixel surrounded by the gate wirings 1 and the source wirings 3 is provided. The reflection electrode 11 is arranged in the region. The common capacitance line 2 is provided in a direction parallel to the gate line 1, and the common capacitance electrode 8 is arranged so as to overlap the common capacitance line 2.

In the TFT, a part of the gate wiring 1 is used as a gate electrode, and the source electrode 6 and the source electrode 6 are sandwiched on the gate electrode via the gate insulating film 13 and the channel layer 5 and the contact layer 14 on the gate electrode. A drain electrode 7 is formed. The source electrode 6 is connected to the source wiring 3 via the lead portion 6a, and the drain electrode 7 is connected to the reflective electrode 11 via the drain contact hole 9 formed in the interlayer insulating film 15 thereon. Note that the channel layer 5 is a semiconductor layer made of amorphous silicon.

The gate wiring 1 and the common capacitance wiring 2 are simultaneously formed of the same material (for example, a laminated film of Ti and Al) on the glass substrate 12, and thereafter, a gate insulating film 13 is formed on the entire surface. After forming the source wiring 3, the TFT, the common capacitance electrode 8, and the contact holes 9, 10, the passivation insulating film 26 and the interlayer insulating film 15 are formed on the entire surface excluding the contact holes 9, 10, and the reflective electrode 11 is formed. The source electrode 6 and the drain electrode 7 are formed simultaneously with the source wiring 3 and the common capacitance electrode 8 using the same material (for example, a laminated film of Ti and Al).

In the region where the common capacitance electrode 8 is formed, the common capacitance wiring 2, the gate insulating film 13, the common capacitance electrode 8, the passivation insulating film 26, the interlayer insulating film 15, and the reflective electrode 11 are stacked in this order on the glass substrate 12. ing. Further, for example, in the region of the lead-out portion 8a of the common capacitance electrode 8 in the A′-B ′ portion, the common capacitance line 2 is not formed, On the substrate 12, a gate insulating film 13, a lead portion 8a of the common capacitance electrode 8, a passivation insulating film 26, and an interlayer insulating film 15 are laminated in this order. Further, the lead portion 8a of the common capacitance electrode 8 is connected to the reflection electrode 11 via the common capacitance electrode contact hole 10 formed in the interlayer insulating film 15 thereon. Here, the driving of the liquid crystal in the liquid crystal layer 23 of FIG. 3 is determined by the potential difference between the pixel electrode (reflection electrode 11) and the counter electrode (transparent electrode 22).
A common capacitance electrode 8 and a common capacitance line 2 are provided to hold the data until the FT scan is performed. The common capacitance line 2 is electrically connected to the counter electrode (transparent electrode 22), and the capacitance formed between the common capacitance electrode 8 and the common capacitance line 2 is the common capacitance line 2 (or the transparent electrode 2).
2) and the reflective electrode 11 (or the drain electrode 7) are connected in parallel with the capacitance of the liquid crystal.

In such an array structure, a pattern defect serving as a bright spot occurs, and after the completion of the array, the following two methods can be considered as a method of performing rescue and performing black point processing. One is a source electrode 6 and a drain electrode 7
This is the case where a film residue that causes a short circuit occurs. The lead-out portion 6a of the source electrode 6 in the portion AB in the drawing is cut by laser irradiation, the TFT and the source wiring 3 are separated, and furthermore, CD in the drawing. In this case, the drain electrode 7 is electrically contacted with the gate wiring 1 by laser irradiation. The other is a case where the common capacitance electrode 8 and the common capacitance line 2 are short-circuited, and the wiring (leading portion 8a) connecting the common capacitance electrode 8 and the common capacitance electrode contact hole 10 in the A′-B ′ portion in the drawing is formed by a laser. This is a case where the drain electrode 7 and the gate wiring 1 are electrically contacted by laser irradiation in the case of cutting by irradiation and laser irradiation in CD in the figure.

In any case, in the portion having the structure as shown in FIG. 4B, the lead portion 6a of the source electrode 6 or the lead portion 8a of the common capacitance electrode 8 is cut, and the structure as shown in FIG. It is necessary to contact the drain electrode 7 and the gate wiring 1 in a part.

A conventional YAG laser (wavelength is 1064n)
m) By irradiation, such a portion as the former stage (FIG. 4)
FIG. 5 is a cross-sectional view after laser irradiation when cutting (b) and FIG. 4 (c)).

FIGS. 5 (a) and 5 (b) correspond to FIG.
FIG. 4B shows a state in which the extraction portion 6a of the source electrode 6 is cut by laser irradiation, and FIG. 4C shows a state in which the drain electrode 7 and the gate wiring 1 are in contact.

In FIG. 5A, the interlayer insulating film 15 appears on the surface layer in a projecting manner by laser irradiation (17 in the figure), and the metal of the source electrode 6 or the common capacitance electrode 8 of the lead-out portion is also brought to the surface. It appears on the layer (16 in the figure). The protruding metal electrode 16 serves as a transparent electrode 22 (see FIG. 3) of the opposing substrate when the TFT array substrate and the opposing substrate are bonded to each other.
Short) or a non-aligned portion of the liquid crystal is formed in the protruding portion, so that it may not be possible to surely make a black spot.

In FIG. 5B, the gate wiring 1 and the drain electrode 7 can be brought into contact with each other by laser irradiation, but the interlayer insulating film 15 appears on the surface layer in a protruding manner (FIG. 5B). 17), the metal of the drain electrode 7 or the metal of the gate wiring 1 may also appear on the surface layer (16 in the figure), and as in the case of FIG. 3) or a non-aligned portion of the liquid crystal is formed in the protruding portion,
Black spots may not be reliably formed.

Regarding the protrusion (17) of the interlayer insulating film 15, when a laser beam having a long wavelength is irradiated, the laser power is absorbed by the metal layer below the interlayer insulating film 15, and When scattered, interlayer insulating film 15
Is also scattered together, and the interlayer insulating film 15 has a very large thickness of, for example, 2.5 to 3 μm, so that the protrusion becomes large. Note that the passivation insulating film 26 is much thinner than the interlayer insulating film 15.

In view of the above problems, the present invention makes it possible to surely make a black spot without projecting an interlayer insulating film or projecting a cut or contacted electrode (wiring) metal due to laser irradiation during rescue. It is an object of the present invention to provide a method for manufacturing a liquid crystal display device.

[0023]

In order to solve this problem, according to the present invention, in laser irradiation in rescue of a TFT array substrate, first, an interlayer insulating film or the like above a portion to be cut or contacted is removed by laser irradiation. Thereafter, cutting is further performed by laser irradiation and contact is made by laser irradiation.

According to the present invention, black spots can be formed without projecting into the surface layer of the interlayer insulating film by laser irradiation and without projecting into the surface layer of the cut or contacted electrode (wiring) metal. can do.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION
A light-transmitting substrate, a plurality of gate wirings and source wirings formed so as to intersect on the light-transmitting substrate, and a thin film transistor formed at each intersection of the gate wiring and the source wiring;
A thin film transistor comprising: an interlayer insulating film formed on the entire surface of the light-transmitting substrate including the thin film transistor, the gate wiring and the source wiring; and a pixel electrode formed on the interlayer insulating film in each region surrounded by the gate wiring and the source wiring. A source electrode and a drain electrode are formed through a gate insulating film and a channel layer thereover so as to sandwich a part of the gate wiring as a gate electrode and on the gate electrode, and a lead portion is formed on the source electrode. A TFT array substrate in which the source electrode is connected to the source wiring through the lead portion, the drain electrode is connected to the pixel electrode through a contact hole formed in the interlayer insulating film above the TFT array substrate, and a transparent electrode opposed to the pixel electrode is provided. A liquid crystal display device in which a liquid crystal layer is sandwiched between the liquid crystal display device and a counter substrate. A first step of removing an interlayer insulating film on a lead portion of a source electrode of the thin film transistor and an interlayer insulating film on a drain electrode of the thin film transistor by irradiation with laser light; A second step of separating the thin film transistor from the source wiring by removing the lead portion of the source electrode by laser light irradiation, and connecting the drain electrode and the gate electrode of the thin film transistor subjected to the first step by laser light irradiation And a third step of manufacturing the liquid crystal display device.

According to the first aspect of the present invention, after the interlayer insulating film at the portion to be cut or contacted is removed by laser irradiation, the lead portion of the source electrode is further reliably cut by laser irradiation, and the drain electrode is removed. By contacting the gate electrode, the protrusion of the interlayer insulating film due to laser irradiation during rescue, the protrusion of the metal of the cut-out lead portion of the source electrode, and the protrusion of the metal of the drain electrode and the gate electrode contacted are eliminated. Can be. Therefore, in a liquid crystal display device using such a TFT array substrate and sandwiching a liquid crystal layer between the TFT substrate and a counter substrate, a pixel portion having a pattern defect can be reliably turned into a black dot, and the yield of the liquid crystal display device can be reduced. It has the effect of being able to improve.

According to a second aspect of the present invention, in the first step, a laser beam having a wavelength of 355 nm is irradiated from the surface of the TFT array substrate on which the pixel electrode is formed, and in the second step, the wavelength is 1064 nm or 532 nm laser light is irradiated from the front side of the TFT array substrate.
2. The method for manufacturing a liquid crystal display device according to claim 1, wherein a laser beam of 064 nm or 532 nm is irradiated from the front surface side of the TFT array substrate. It is preferable to prevent the protrusion of the film, the protrusion of the metal of the cut-out lead portion of the source electrode, and the protrusion of the metal of the drain electrode and the gate electrode which are in contact.

According to a third aspect of the present invention, a light-transmitting substrate, a plurality of gate wirings and source wirings formed so as to intersect on the light-transmitting substrate, and each intersection of the gate wiring and the source wiring are formed. A thin film transistor; an interlayer insulating film formed on the entire surface of the light-transmitting substrate including the thin film transistor, the gate wiring and the source wiring; and a pixel electrode formed on the interlayer insulating film in each region surrounded by the gate wiring and the source wiring; A common capacitance electrode provided below the pixel electrode with an interlayer insulating film interposed therebetween, and the thin film transistor has a part of the gate wiring as a gate electrode, and the gate insulating film and the gate insulating film on the gate electrode so as to sandwich the gate electrode. A source electrode and a drain electrode were formed via the channel layer of the above, the source electrode was connected to the source wiring, and the drain electrode was formed on the interlayer insulating film thereon. A TFT array substrate connected to a pixel electrode through a first contact hole, a lead portion provided in the common capacitance electrode, and the lead portion connected to the pixel electrode through a second contact hole formed in an interlayer insulating film thereon; And a method of manufacturing a liquid crystal display device in which a liquid crystal layer is sandwiched between a pixel electrode and a counter substrate provided with a transparent electrode disposed to face the pixel electrode. A first step of removing an interlayer insulating film on a lead portion excluding a second contact hole portion connected to a pixel electrode and an interlayer insulating film on a drain electrode of a thin film transistor by laser light irradiation; The second step of separating the common capacitance electrode from the pixel electrode by removing the drawn-out portion of the common capacitance electrode subjected to the process by laser light irradiation, and the first step were performed. It is a manufacturing method of a liquid crystal display device which comprises a third step of connecting the drain electrode and the gate electrode of the film transistor by laser light irradiation.

According to the third aspect of the present invention, after the pixel electrode and the interlayer insulating film at the position where the common capacitance electrode is cut are removed by laser irradiation, the lead portion of the common capacitance electrode is further reliably cut by laser irradiation. In addition, after removing the interlayer insulating film at the place to be contacted by laser irradiation, the drain electrode and the gate electrode are further contacted by laser irradiation, so that the interlayer insulating film is projected or cut by laser irradiation at the time of rescue. The protrusion of the metal of the lead portion of the common capacitance electrode and the protrusion of the metal of the contacted drain electrode and gate electrode can be eliminated. Therefore, in a liquid crystal display device using such a TFT array substrate and sandwiching a liquid crystal layer between the substrate and a counter substrate, a short circuit occurs with a transparent electrode of the counter substrate, or a non-aligned portion of liquid crystal is generated in a protruding portion. Thus, the pixel portion having the pattern defect can be reliably turned into a black spot, and the yield of the liquid crystal display device can be improved.

According to a fourth aspect of the present invention, in the first step, a laser beam having a wavelength of 355 nm is irradiated from the surface side of the TFT array substrate on which the pixel electrodes are formed, and in the second step, the wavelength is 1064 nm or 532 nm laser light is irradiated from the front side of the TFT array substrate.
4. A method for manufacturing a liquid crystal display device according to claim 3, wherein a laser beam of 064 nm or 532 nm is irradiated from the front side of the TFT array substrate. It is preferable to eliminate the protrusion of the film, the protrusion of the metal of the cut-out lead portion of the common capacitance electrode, and the protrusion of the metal of the drain electrode and the gate electrode that are in contact.

According to a fifth aspect of the present invention, the surface of the interlayer insulating film below the pixel electrode is formed in an uneven shape so that the pixel electrode has a function as a reflector and the surface of the pixel electrode is formed in an uneven shape. The method for manufacturing a liquid crystal display device according to any one of claims 1 to 4, wherein a diffuse reflectance of the pixel electrode as a reflection plate is increased, and a liquid crystal display device with high display quality can be realized. It has the action of:

According to a sixth aspect of the present invention, there is provided the method of manufacturing a liquid crystal display device according to the fifth aspect, wherein the interlayer insulating film is made of a photosensitive acrylic resin. The processing step can be performed using a normal photolithography step apparatus.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device which performs the first, second and third steps in the method of manufacturing a liquid crystal display device according to any one of the first to sixth aspects. A liquid crystal display device manufactured using this device has an effect of increasing the manufacturing yield.

An eighth aspect of the present invention is a liquid crystal display device manufactured by using the apparatus for manufacturing a liquid crystal display device according to the seventh aspect, and has an effect that the production yield is high. .

According to a ninth aspect of the present invention, there is provided a liquid crystal display manufactured by the method for manufacturing a liquid crystal display device according to any one of the first to sixth aspects, wherein a part of the pixel is made black. This is an apparatus and has an effect that the production yield is high.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following first and second embodiments, a rescue method to be performed on a pixel portion having a pattern defect serving as a bright spot after the manufacturing process of the TFT array substrate shown in FIG. explain. The configuration as a liquid crystal display device is the same as that shown in FIG. In the TFT array substrate,
The surface on which the pixel electrode (here, the reflective electrode 11) exists is the front surface, and the surface on which the glass substrate 12 is present is the back surface.

(First Embodiment) FIG. 1 is a sectional view showing a rescue method according to a first embodiment of the present invention. The rescue method here is based on the source electrode 6
FIG. 1 (a) shows a case where a lead-out portion 6a of the source electrode 6 is cut off at a portion AB in FIG. FIG. 1B shows a step of electrically separating the TFT 3 from the TFT, and FIG. 1B shows a step of bringing the drain electrode 7 into contact with the gate wiring 1 at the portion CD in FIG. 4A. Things.

The step of cutting out the lead portion 6a of the source electrode 6 will be described first. Fig. 1 (a) -1 (same as Fig. 4 (b)) shows a cross-sectional view before laser irradiation.
There is a gate insulating film 13 on a glass substrate 12, a source electrode 6 to be cut, a passivation insulating film 26,
An interlayer insulating film 15 is provided. In such a structure, first, an ultraviolet laser having a wavelength of 355 nm (short wavelength) is irradiated from the surface side of the TFT array substrate to the laser irradiation portion 18 for cutting, so that the interlayer insulating film 1
5 and the passivation insulating film 26 are removed (FIG. 1).
(a) -2). At this time, even if the extraction portion 6a of the source electrode 6 to be cut may be partially removed, it cannot be reliably cut. Further, the interlayer insulating film 15 in the removed region,
The passivation insulating film 26 may be removed so as to leave a little.

Next, when the wavelength is 1064 nm or 532 n
By irradiating a laser beam having a long wavelength of m to the laser irradiation portion 18 for cutting from the front side of the TFT array substrate, the lead portion 6a of the source electrode 6 which could not be cut sufficiently earlier is reliably cut (FIG. 1). (a) -3).

Next, the step of bringing the drain electrode 7 into contact with the gate wiring 1 will be described. FIG. 1 (b) -1 (the same as FIG. 4 (c)) shows a cross-sectional view before laser irradiation. TFT is formed on the glass substrate 12,
The passivation insulating film 26 and the interlayer insulating film 1
5, the reflection electrode 11 is arranged. In such a structure, first, an ultraviolet laser having a wavelength of 355 nm (short wavelength) is irradiated to the contact laser irradiation site 19 from the front side of the TFT array substrate, and first, the interlayer insulating film 15 and the passivation insulating film 26 are removed. (FIG. 1 (b) -2).

Next, when the wavelength is 1064 nm or 532 n
By irradiating the laser beam for contact 19 from the front side of the TFT array substrate with a laser beam having a long wavelength of m, the drain electrode 7 is melted and brought into contact with the gate wiring 1 (FIG. 1 (b) -3). .

1 (a) -3 and FIG. 1 (b) -3 in which laser beams of the same wavelength can be used.
In the step of (a) -3, the lead portion 6a of the source electrode 6 is scattered, and in the step of FIG. 1 (b) -3, the drain electrode 7 is melted. This is because the power is increased and the laser power is reduced in the process of FIG. 1 (b) -3.

In the above description, FIGS. 1 (a) -1 to 1 (a) -3
1 and the processes of FIGS. 1 (b) -1 to 1 (b) -3 have been described separately. In practice, however, the process of FIG. 1 (a) -2 and the process of FIG. Can be performed continuously since only the irradiation location is different. The subsequent steps of FIG. 1 (a) -3 and FIG. 1 (b) -3 are performed separately.

Table 1 shows whether or not the black spotting process could be performed by changing the laser energy at the wavelength of 355 nm or 532 nm.

[0045]

[Table 1]

According to this, it was found that black spotting processing was possible in a certain laser energy range.

As described above, according to the present embodiment, after removing the interlayer insulating film 15 and the passivation insulating film 26 at the locations to be cut or contacted by laser irradiation, furthermore, the lead portion 6 of the source electrode 6 is further irradiated by laser irradiation.
a, and the drain electrode 7 is brought into contact with the gate wiring 1 by laser irradiation, thereby projecting the interlayer insulating film 15 by laser irradiation at the time of rescue as shown in FIG. The protrusion of the metal of the lead portion 6a and the protrusion of the metal of the drain electrode 7 and the gate wiring 1 contacted can be eliminated. Therefore, when such a TFT array substrate is used and a liquid crystal display device as shown in FIG. 3 is formed by sandwiching a liquid crystal layer between the TFT substrate and the counter substrate, the transparent electrode 22 (FIG. And the non-aligned portion of the liquid crystal does not occur in the protruding portion, and the pixel portion having the pattern defect can be reliably turned into a black dot, thereby improving the yield of the liquid crystal display device. Can be.

Since the laser light has a greater physical scattering property as the wavelength becomes shorter, it can remove any kind of film, and is suitable for removing only the surface layer.
However, it is difficult to completely remove and make contact.
Conversely, as the wavelength becomes longer, the thermal scattering property increases, and it is possible to completely remove and make contact. Therefore,
In the present embodiment, the metal film is removed or brought into contact for rescue. In the step of removing the insulating film above the metal film, short-wavelength laser light is irradiated (FIG. 1 (a) -2). , FIG. 1 (b) -2), and in the step of completely removing or contacting the metal film, long-wavelength laser light is irradiated (FIGS. 1 (a) -3, 1 (b) -3). .

(Second Embodiment) FIG. 2 is a cross-sectional view showing a rescue method according to a second embodiment for each process. The rescue method here is a case where the common capacitance electrode 8 and the common capacitance line 2 are short-circuited.
4A shows a step of cutting the lead-out portion 8a of the common capacitance electrode 8 at the portion A'-B 'in FIG. 4A and electrically separating the common capacitance electrode 8 from the reflection electrode 11. FIG. 2 (b) shows a step of contacting the drain electrode 7 and the gate wiring 1 at the portion CD in FIG. 4 (a).

The step of cutting out the lead portion 8a of the common capacitance electrode 8 will be described first. FIG. 2 (a) -1 shows a cross-sectional view before laser irradiation, and FIG.
The gate insulating film 13 has a common capacitance electrode 8 to be cut, a passivation insulating film 26, and an interlayer insulating film 15 disposed thereon. In such a structure,
First, an ultraviolet laser having a wavelength of 355 nm is irradiated to the cut laser irradiation portion 18 from the front surface side of the TFT array substrate, thereby removing the interlayer insulating film 15 and the passivation insulating film 26 at that portion (FIG. 2 (a)). ) -2).
At this time, even if the lead-out portion 8a of the common capacitance electrode 8 to be cut may be partially cut, it cannot be cut reliably. Further, the interlayer insulating film 15 and the passivation insulating film 26 in the removal region may be removed so as to remain a little.

Next, when the wavelength is 1064 nm or 532 n
By irradiating the laser beam of m to the cut laser irradiating portion 18 from the front surface side of the TFT array substrate, the lead portion 8a of the common capacitance electrode 8 which could not be sufficiently cut previously
(Fig. 2 (a) -3).

Next, the step of bringing the drain electrode 7 into contact with the gate wiring 1 will be described. FIG. 2 (b) -1 (same as FIG. 4 (c)) shows a cross-sectional view before laser irradiation. TFT is formed on the glass substrate 12,
The passivation insulating film 26 and the interlayer insulating film 1
5, the reflection electrode 11 is arranged. In such a structure, an ultraviolet laser having a wavelength of 355 nm
Irradiation is performed on the contact laser irradiation site 19 from the front side of the T array substrate, and first, only the interlayer insulating film 15 is removed (FIG. 2 (b) -2).

Next, when the wavelength is 1064 nm or 532 n
By irradiating a laser beam of m to the contact laser irradiation location 19 from the front side of the TFT array substrate, the drain electrode 7 is melted and brought into contact with the gate wiring 1 (FIG. 2 (b) -3).

In the above description, FIGS. 2 (a) -1 to 2 (a) -3
2 and the processes of FIGS. 2 (b) -1 to 2 (b) -3 have been described separately, but actually, the process of FIG. 2 (a) -2 and the process of FIG. Can be performed continuously since only the irradiation location is different. The subsequent steps of FIG. 2 (a) -3 and FIG. 2 (b) -3 are performed separately.

Table 2 shows whether or not the black spotting process could be performed by changing the laser energy at a wavelength of 355 nm or at a wavelength of 532 nm.

[0056]

[Table 2]

According to this, it was found that black spotting processing was possible within a certain laser energy range.

As described above, according to the present embodiment, after removing the interlayer insulating film 15 and the passivation insulating film 26 at the locations where the common capacitance electrodes 8 are to be cut off,
Further, the lead portion 8a of the common capacitance electrode 8 is irradiated with the laser.
After the interlayer insulating film 15 and the passivation insulating film 26 to be contacted are removed by laser irradiation, the drain electrode 7 and the gate wiring 1 are further contacted by laser irradiation, as shown in FIG. It is possible to eliminate the protrusion of the interlayer insulating film 15 due to laser irradiation at the time of rescue, the protrusion of the metal of the cut-out lead portion 8a of the common capacitance electrode 8, and the protrusion of the metal of the drain electrode 7 and the gate wiring 1 which are in contact. it can. Therefore, when such a TFT array substrate is used and a liquid crystal display device as shown in FIG. 3 is formed by sandwiching a liquid crystal layer between the TFT substrate and the counter substrate, the transparent electrode 22 (FIG. And the non-aligned portion of the liquid crystal does not occur in the protruding portion, and the pixel portion having the pattern defect can be reliably turned into a black spot, thereby improving the yield of the liquid crystal display device. Can be.

In the first and second embodiments,
As shown in FIG. 3, the surface of the interlayer insulating film 15 is formed in an uneven shape,
By forming the reflective electrode 11 thereon in a concavo-convex shape along with it, the diffuse reflectance is increased, and a liquid crystal display device with high display quality can be realized.

In the first and second embodiments,
By using a photosensitive acrylic resin for the interlayer insulating film 15 whose surface is uneven, a process of processing the interlayer insulating film 15 into an uneven shape can be performed by using a usual photolithography process apparatus.

The rescue method according to the present invention can be applied to a liquid crystal display device in which the common capacitance electrode 8 and the common capacitance line 2 are not provided.

[0062]

As described above, according to the present invention, in the laser irradiation in the rescue of the TFT array substrate, first, the interlayer insulating film or the like on the portion to be cut or contacted is removed by the laser irradiation, and then the laser irradiation is performed. By cutting, and making contact by laser irradiation, the protrusion of the interlayer insulating film to the surface layer,
Black spots can be obtained without projecting the cut or contacted electrode (wiring) metal to the surface layer.
Accordingly, an advantageous effect that the yield as a liquid crystal display device can be improved is brought about.

[Brief description of the drawings]

FIG. 1 is a process sectional view illustrating a method for manufacturing a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a process sectional view illustrating a method for manufacturing a liquid crystal display device according to a second embodiment of the present invention.

FIG. 3 is a structural sectional view of a reflective liquid crystal display device.

4A and 4B are a plan view and a cross-sectional view illustrating details of a TFT array substrate used in the liquid crystal display device of FIG.

FIG. 5 is a structural sectional view after rescue by a conventional method of manufacturing a liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gate wiring 2 Common capacitance wiring 3 Source wiring 4 Insulating film 5 Channel layer 6 Source electrode 7 Drain electrode 8 Common capacitance electrode 9 Drain contact hole 10 Common capacitance electrode contact hole 11 Reflection electrode 12 Glass substrate 13 Gate insulating film 14 Contact layer 15 Interlayer insulating film 16 Protruding metal electrode 17 Protruding interlayer insulating film 18 Laser irradiation place for cutting 19 Laser irradiation place for contact 20 Polarizer 21 Color filter 22 Transparent electrode 23 Liquid crystal layer 24 Thin film transistor (TFT) 25 Phase difference plate 26 Passivation insulation film

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yutaka Hanaki 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 2H092 JA26 JA34 JA37 JA41 JA46 JB07 JB22 JB31 JB57 JB69 KA05 KB22 KB24 KB25 MA46 MA47 MA52 NA15 NA29 PA08 PA10 PA11 5F033 GG04 QQ06 QQ53 RR21 VV15 XX36 5F110 AA27 BB01 CC07 DD02 HM17 HM19 NN02 NN03 NN72 NN80

Claims (9)

[Claims] A light-transmitting substrate; a plurality of gate wirings and source wirings formed so as to intersect on the light-transmitting substrate; a thin film transistor formed at each intersection of the gate wiring and the source wiring; An interlayer insulating film formed on the entire surface of the light-transmitting substrate including the thin film transistor, the gate wiring, and the source wiring; and a pixel electrode formed on the interlayer insulating film in each region surrounded by the gate wiring and the source wiring. Wherein the thin film transistor has a part of the gate wiring as a gate electrode, and forms a source electrode and a drain electrode on the gate electrode with the gate insulating film and a channel layer thereover so as to sandwich the gate electrode. A lead portion provided on the source electrode, connected to the source wiring through the lead portion, and the drain electrode is connected to the interlayer Manufacturing of a liquid crystal display device in which a liquid crystal layer is sandwiched between a TFT array substrate connected to the pixel electrode via a contact hole formed in an insulating film and a counter substrate provided with a transparent electrode arranged to face the pixel electrode The method according to claim 1, wherein, for a part of the pixel portion on the TFT array substrate, the interlayer insulating film on the lead portion of the source electrode of the thin film transistor, and the interlayer insulating film on the drain electrode of the thin film transistor, A first step of removing by irradiation, and a second step of separating the thin film transistor from the source wiring by removing the lead portion of the source electrode of the thin film transistor subjected to the first step by laser light irradiation. The drain electrode and the gate electrode of the thin film transistor subjected to the first step are irradiated with laser light. A method of manufacturing a liquid crystal display device, comprising a third step of connecting. A first step of irradiating a laser beam having a wavelength of 355 nm from the surface of the TFT array substrate on which the pixel electrode is formed, and a second step of applying a laser beam having a wavelength of 1064 nm or 532 nm to the TFT array substrate; 2. The liquid crystal display device according to claim 1, wherein the irradiation is performed from the front side of the TFT array substrate, and the third step is to irradiate laser light having a wavelength of 1064 nm or 532 nm from the front side of the TFT array substrate. Method. 3. A light-transmitting substrate, a plurality of gate wirings and source wirings formed on the light-transmitting substrate so as to intersect, a thin film transistor formed at each intersection of the gate wiring and the source wiring, An interlayer insulating film formed on the entire surface of the light-transmitting substrate including a thin film transistor, a gate wiring, and a source wiring; a pixel electrode formed on the interlayer insulating film in each region surrounded by the gate wiring and the source wiring; A common capacitance electrode provided below the pixel electrode with the interlayer insulating film interposed therebetween, wherein the thin film transistor has a part of the gate wiring as a gate electrode, and sandwiches the gate electrode and on the gate electrode. Forming a source electrode and a drain electrode via the gate insulating film and a channel layer thereover, connecting the source electrode to the source wiring, A drain electrode is connected to the pixel electrode through a first contact hole formed in the interlayer insulating film thereon, and a lead portion is provided in the common capacitance electrode, and the lead portion is formed in the interlayer insulating film thereon. Second
T connected to the pixel electrode through the contact hole of
A method for manufacturing a liquid crystal display device in which a liquid crystal layer is sandwiched between an FT array substrate and an opposing substrate provided with a transparent electrode arranged to oppose the pixel electrode, the method comprising: Removing the interlayer insulating film on the lead portion excluding the second contact hole portion of the common capacitance electrode connected to the pixel electrode, and removing the interlayer insulating film on the drain electrode of the thin film transistor by laser light irradiation. A first step of removing the common capacitor electrode and the pixel electrode by removing the lead-out portion of the common capacitor electrode subjected to the first step by irradiating a laser beam; A third step of connecting the drain electrode and the gate electrode of the thin film transistor subjected to the first step by laser light irradiation. Manufacturing method of a display device. 4. The first step is to irradiate a laser beam having a wavelength of 355 nm from the surface of the TFT array substrate on which the pixel electrode is formed, and the second step is to irradiate the laser beam having a wavelength of 1064 nm or 532 nm. 4. The method according to claim 3, wherein the irradiation is performed from the front side of the TFT array substrate, and the third step is to irradiate laser light having a wavelength of 1064 nm or 532 nm from the front side of the TFT array substrate. Method. 5. The pixel electrode has a function as a reflector,
5. The liquid crystal display device according to claim 1, wherein the surface of the interlayer insulating film below the pixel electrode is formed in an uneven shape so that the surface of the pixel electrode is formed in an uneven shape. Manufacturing method. 6. The method according to claim 5, wherein the interlayer insulating film is made of a photosensitive acrylic resin. 7. A manufacturing apparatus for a liquid crystal display device, which performs the processing of the first, second, and third steps in the method for manufacturing a liquid crystal display device according to claim 1. 8. A liquid crystal display device manufactured using the liquid crystal display device manufacturing apparatus according to claim 7. 9. A liquid crystal display device manufactured by the method for manufacturing a liquid crystal display device according to claim 1, wherein a part of pixels is blackened.