JP3322556B2 - Flat panel display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat display device such as a liquid crystal display device and a plasma display and a method of manufacturing the same, and more particularly, to an active matrix type liquid crystal display device having a switching element such as a thin film transistor (TFT) and the like. Suitable for manufacturing method.

[0002]

2. Description of the Related Art An active matrix type liquid crystal display device will be described as a conventional flat display device with reference to FIGS.

First, reference is made to FIG. The illustrated liquid crystal display device 70 includes an active matrix substrate 59,
And an opposing substrate 60 disposed opposing thereto. A liquid crystal layer (not shown) is sealed between the two substrates 59 and 60 to form a display area 51. On the active matrix substrate 59, a drive area 71 is provided around the display area 51.

[0004] In the driving area 71, COG (Chip o
n G1ass) method, a plurality of driving drivers 55 are mounted. A predetermined signal is sent from the driving driver 55 of the driving area 71 to the scanning wiring 53 and the signal wiring 54,
Switching element (not shown) provided in display area 51
Is driving. The driving drivers 55 are connected by a common wiring 52 provided in the driving area 71. The common wiring 52 is a wiring commonly used for connection of a power supply to the driving driver 55, signal transmission, and the like.

An FP (not shown) is connected to the driving driver 55.
C (F1exib1e Printed Circuit)
A drive current or a signal is input from the input terminal 58 via the common wiring 52 using t) or the like.

FIG. 8 is a sectional view taken along the line BB ′ of the driver region 71 of the active matrix substrate 59. As can be seen from FIG. 8, the common wiring 52 is provided in the driver area 71 on the active matrix substrate 59. The driving driver 55 is connected to the common wiring 52, the scanning wiring 53, or the signal wiring 54 via a bump 56 of the driving driver 55 and an anisotropic conductive film (hereinafter, referred to as ACF) 57.

[0007]

In recent years, regulations on EMI (unwanted radiation) have become stricter, and it is essential to reduce EMI of a display device. As a method for reducing the EMI of the display device, for example, Japanese Patent Application Laid-Open No. 6-37 shown in FIG.
As in the liquid crystal driving device disclosed in Japanese Patent Publication No. 478,
A method for reducing EMI by attaching a metal foil tape to a power supply wiring has been proposed.

However, in order to effectively use the above method, a metal foil tape must be attached to almost the entire driving area, which causes an increase in the cost of the display device. In addition, in the above-described method, when a metal foil tape is applied to the wiring, there is a high possibility that the wiring is damaged or disconnected, so that the non-defective rate of the display device is reduced. In addition, during the manufacturing process of the display device, when the display device being manufactured is moved, the wiring is moved in an exposed state, so that the wiring is likely to be disconnected during the movement of the display device, and a good display device is manufactured. The rate was falling.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide various kinds of insulating films (interlayer insulating films, color filters, etc.) used for forming a display device. On the common wiring,
An object of the present invention is to provide an inexpensive EMI countermeasure display device and a method of manufacturing the same, in which a conductive film is formed on the common wiring to achieve protection of the wiring and hardly increase the number of manufacturing steps.

[0010]

In order to solve the above-mentioned problems, a flat display device according to the present invention comprises a display area in which at least a plurality of scanning lines and a plurality of signal lines are formed, the scanning lines and the signal lines. And a driving area provided with a driving driver for transmitting a signal to at least one of a common wiring connecting the driving drivers or a common wiring connecting the driving driver and an external input terminal. Is covered with an insulating film, and a conductive film is formed on the insulating film, thereby achieving the above object.

The flat display device according to the present invention can suppress the generation of EMI with a simple structure due to the above structure. In addition, since the insulating film not only suppresses the generation of EMI but also serves to protect the common wiring, the reliability of the display device is improved.

The conductive film may be formed by patterning the same film as the pixel electrode.

The insulating film may be formed of the same film as an interlayer insulating film covering the scanning lines or the signal lines in the display area.

The conductive film may be connected to a GND wiring.

[0015] This makes it possible to further suppress the occurrence of EMI.

The method for manufacturing a flat panel display according to the present invention comprises:
On a substrate, a scan wiring is formed, an insulating film is provided over the scan wiring, and a signal wiring is formed so as to intersect with the scan wiring.
Forming a switching element in the vicinity of each intersection of the scanning wiring and the signal wiring; providing a common wiring for a driver on the substrate; and forming upper parts of the scanning wiring, the signal wiring and the switching element. Forming an interlayer insulating film on the common wiring, forming an insulating film covering the common wiring by patterning the interlayer insulating film, and forming a contact hole penetrating the interlayer insulating film in the interlayer insulating film. Forming a pixel electrode connected to the switching element through the contact hole on the interlayer insulating film, and forming a conductive film on the insulating film. This achieves the above object.

The method for manufacturing a flat panel display according to the present invention comprises:
EMI countermeasures can be taken without requiring an increase in the number of steps, and no cost increase occurs. In addition, the common wiring can be protected even during the manufacturing process, and the disconnection does not occur, so that the yield rate is improved.

[0018]

Embodiments of the present invention will be described below.

(Embodiment 1) FIG. 1 shows a configuration of a liquid crystal display device 15 provided with an active matrix substrate according to the present invention. FIG. 2 shows a cross section taken along line AA ′ of the liquid crystal display device 15.

First, the structure of the liquid crystal display device 15 will be described. On the active matrix substrate 9, TFT, M
A display area 1 in which switching elements (not shown) such as IMs are arranged in a matrix is provided. On the display area 1, a transparent counter substrate 10 such as a glass substrate is arranged at a predetermined interval, and a liquid crystal layer is provided between the counter substrate 10 and the active matrix substrate 9.

Display area 1 of active matrix substrate 9
A drive region 16 is provided in a region other than the above. The drive area 16 may be formed around the entire display area 1 of the active matrix substrate 9. The drive area 16 includes C
A plurality of driving drivers 5 mounted in the OG system are provided. The driving driver 5 sends a predetermined signal to the gate wiring 3 as a scanning wiring and the source wiring 4 as a signal wiring to drive a switching element. The driving drivers 5 are connected by a common wiring 2 provided in the driving area 16.

The driver 5 is supplied with a power supply voltage and a signal from the input terminal 8 via the common wiring 2a. The input terminal 8 is connected to a power supply via an unillustrated FPC or the like. The driving driver 5 is connected to the common wiring 2, 2 a, the gate wiring 3 or the source wiring 4 via the bump 6 and the ACF 7 of the driving driver 5. AC
A paste material or solder may be used instead of F.

The insulating film 11 and the conductive film 12 formed on the insulating film 11 are formed on an area 17 of the driving area 16 where the driving driver 5 is not provided and the common wiring 2 is provided. Is provided. In the present embodiment, the insulating film 11 is formed of an acrylic resin used as a material of an interlayer insulating film (not shown) formed in the display region 1. Further, the conductive film 12 is formed of ITO used as a material of a pixel electrode formed in the display region 1.

In the liquid crystal display device 15, the generation of EMI is suppressed, and the disconnection hardly occurs in the manufacturing process. Also,
By using a low-dielectric-constant insulating film such as an acrylic resin for the insulating film 11, deformation of the waveform of a signal passing through the common wiring 2 can be suppressed. Further, since the insulating film 11 protects the common wiring 2, even if the display device is used in a very severe environment such as high temperature and high humidity, for example, in a car, the performance does not deteriorate.

Next, a method of manufacturing the liquid crystal display device 15 will be described.

First, a tantalum film is formed to a thickness of 4000 Å by a CVD method on a transparent insulating substrate made of a glass substrate, and then patterned to form a gate wiring 3. Then, 2
Anodization was performed for a thickness of 2,000 angstroms.
By performing the anodic oxidation in this manner, the insulating property between the scanning wiring 1 and a semiconductor layer to be formed later is improved, and the additional capacitance (C
s) increases.

Thereafter, a gate insulating film (not shown) made of silicon nitride or the like (not shown) is formed to a thickness of 5000 angstroms by the CVD method on the gate wiring 3, and a Si semiconductor layer (not shown) is continuously formed on the gate insulating film. Then 10
After depositing a thickness of 00 Å, patterning is performed to form a channel portion. Then, n not shown
^A contact portion is formed by ⁺ Si or the like.

Next, Al is deposited at 1000 to 3 by the CVD method.
After the film is formed to a thickness of 000 angstroms, the source wiring 4 is formed by patterning. At this time, the mounting terminals of the common wiring 2 and the gate wiring 3 are also formed at the same time.

Next, an interlayer insulating film having a thickness of 3 μm is formed on the source wiring 4 using a photosensitive acrylic resin by spin coating. This interlayer insulating film also serves as the insulating film 11. The relative permittivity of the acrylic resin is about 3.4, which is lower than the relative permittivity of the inorganic film (the relative permittivity of silicon nitride commonly used as an insulating film is 8). Further, the acrylic resin has high transparency and can be easily formed into a thick film having a thickness of 3 μm by a spin coating method, a roll coating method, or a slot coating method. Therefore, by using an acrylic resin for the interlayer insulating film as described above, the parasitic capacitance between the source wiring and the pixel electrode can be reduced, and the parasitic capacitance between each source wiring 4 and the pixel electrode can be reduced. It is possible to further reduce the influence of crosstalk and the like on the display, and it is possible to obtain a good and bright display.

At this time, since the interlayer insulating film also serves as the insulating film 11, the insulating film 1 can be formed without increasing the manufacturing process.
1 is formed. Further, since the insulating film 11 has a low relative dielectric constant and can easily increase its thickness,
The capacitance on the common wiring 2 is suppressed, and signal delay and deformation of the signal waveform are suppressed. In addition, since an organic resin such as acryl is used to form a pinhole, leakage can be prevented. Further, even when a metal such as aluminum that easily forms a hillock is used for the common wiring 2, the insulating film 11 protects the common wiring 2, so that hillocks of the common wiring 2 can be prevented.

As described above, when a photosensitive acrylic resin is used, a photoresist coating step is not required for patterning, which is advantageous in terms of productivity.

In this embodiment, the acrylic resin used as the material of the interlayer insulating film is colored before application. The reason is that the acrylic resin colored before application is easily patterned, and can be made transparent by performing an overall exposure process after patterning. Such a transparent treatment of the resin can be performed not only optically but also chemically.

Next, on the interlayer insulating film, 15
After depositing to a thickness of 00 Å, patterning was performed to form a pixel electrode (not shown). At this time, the conductive film 12 for EMI countermeasure and the mounting terminal (the connection part of the driving driver 5 and the connection part of the input terminal 8) were formed at the same time. This allows EMI without any additional steps.
Countermeasures and protection of the common wiring 2 can be performed. Further, the connection resistance of the mounting terminal can be stabilized. At this time, it is more preferable to improve the adhesion between the interlayer insulating film and the pixel electrode and the adhesion between the insulating film 11 and the conductive film 12 by roughening the surface of the resin of the interlayer insulating film by ashing or the like.

Thereafter, an alignment film made of polyimide or the like is formed and a rubbing process is performed (not shown). At this time, the thickness of the interlayer insulating film is 3 μm, and since the interlayer insulating film is formed sufficiently thick, the surface of the interlayer insulating film is flattened,
No problem such as alignment disorder occurs. Thereafter, a liquid crystal display panel is completed by interposing a liquid crystal between the active matrix substrate 9 and a counter substrate 10 having a black matrix, a counter electrode, and a color filter (not shown).

Thereafter, the driving driver 5 is connected to the gate wiring 3 and the source wiring 4 by using the ACF 7, and the liquid crystal display device according to the first embodiment of the present invention is completed.

The first embodiment manufactured as described above
In the liquid crystal display device described above, a new process for EMI countermeasures is not required at all in the manufacturing process, so that the cost of the liquid crystal display device does not increase.

Further, the time during which the common wiring 2 is exposed on the substrate surface is reduced as compared with the conventional manufacturing process.
Because the probability of disconnection due to garbage etc. is greatly reduced,
The non-defective rate is greatly improved.

It is to be noted that the function of a color filter may be performed by dyeing the interlayer insulating film. Further, it is also possible to use a material other than acrylic resin as the material of the interlayer insulating film and the insulating film 11. As the material of the interlayer insulating film and the insulating film 11, it is preferable to use a material having a low relative dielectric constant and a high degree of transparency, specifically, a material having a transmittance of 90% or more in the incident light region. For example, polyamideimide (relative dielectric constant 3.5 to 4.0), polyarylate (3.0), polyetherimide (3.2), epoxy (3.5 to 4.0), polyimide with high transparency ( 3.0
To 3.4: for example, a combination of an acid dianhydride containing hexafluoropropylene and a diamine).

(Embodiment 2) A liquid crystal display device 25 of Embodiment 2 will be described with reference to FIGS. FIG. 3 is a sectional view taken along line AA ′ of FIG. Note that the same components as those of the liquid crystal display device 15 of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

In the liquid crystal display device 25 of the second embodiment, E
The anti-MI conductive film 22 covers the insulating film 11. In the liquid crystal display device 25, the EMI countermeasure conductive film 22 is connected to the electrically grounded wiring 23 (hereinafter referred to as GND wiring) formed on the active matrix substrate 9, so that a more effective EMI countermeasure is provided. Has been done. Of course, no cost increase occurs in the present embodiment. It is more effective to ground the drive driver 5, preferably the EMI countermeasure conductive film 11, and the metal bezel 24 (not shown in FIG. 4).

Third Embodiment FIG. 5 shows a liquid crystal display device 35 of a third embodiment. FIG. 5 corresponds to a cross-sectional view taken along line AA ′ of FIG. In the description of the present embodiment, the first embodiment
The same components as those of the liquid crystal display device 15 are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 5, in the liquid crystal display device 35, since the conductive film 32 for EMI countermeasures is connected to the GND wiring 23 formed on the active matrix substrate 9 and the driving driver 5, the ground area is reduced. Therefore, an electrically stable GND potential can be obtained, and effective EMI countermeasures are taken.

Of course, the liquid crystal display device 3 according to the present embodiment
Even with 5, no cost increase occurs. As in the second embodiment, it is more effective to ground the drive driver 5, preferably the EMI countermeasure conductive film 12, and a metal bezel (not shown).

(Embodiment 4) In this embodiment, the present invention is applied to a driver monolithic liquid crystal display device.

The driver monolithic liquid crystal display device is a TFT type liquid crystal display device and a TFT for a display electrode switch.
Is formed by integrally forming a driving driver in a peripheral portion of the display unit, that is, in a driving area. Here, de
Motor drive driver driver monolithic type liquid crystal display device
It is called a nolithic driver .

Hereinafter, the liquid crystal display device of the fourth embodiment will be described with reference to FIG.

A drive region is formed around a display region on the active matrix substrate 43 in which liquid crystal is sealed between a transparent counter substrate and an active matrix substrate 43 having TFTs as switching elements. Monolithic formed as drive driver in its drive area
The driver 40 sends a predetermined signal to a gate wiring and a source wiring formed on the active matrix substrate 43,
Driving TFT. The monolithic driver 40 is formed on the active matrix substrate 43 at the same time as the TFT, and the monolithic driver 40 itself is a portion that generates EMI and the like. Therefore, in order to suppress the occurrence of EMI and the like, it is necessary to cover not only the wires connecting the elements forming the monolithic driver 40 but also the elements.

The monolithic driver 40 supplies a power supply voltage and a signal from an input terminal using an FPC or the like (not shown). Then, an insulating film 41 is formed over substantially the entire driving region, and a conductive film 42 is formed on the insulating film 41.
Also in the present embodiment, the insulating film 41 is formed of an acrylic resin used as a material of an interlayer insulating film, and the conductive film 42 is formed of ITO used for a pixel electrode.

According to the above configuration, the generation of EMI is suppressed, and the failure of the driver during the manufacturing process hardly occurs. In addition, by using a low dielectric constant insulating film such as an acrylic resin for the insulating film 41, the driver monolithic can be used.
It is possible to suppress distortion of click portions of the signal (deformation of the signal waveform). Further, even when the display device is used in a very harsh environment such as in a car, the insulating film 41 can be used as a driver monolith.
Protect your chic .

As described above, the active matrix substrate of the display device of the present embodiment is configured.

In the manufacturing process of the active matrix substrate of the present embodiment, the insulating film 41 is formed simultaneously with the formation of the interlayer insulating film, as in the manufacturing process of the active matrix substrates of the first to third embodiments. Therefore, a new process for EMI countermeasures is not required at all in the manufacturing process, so that the liquid crystal display device of the present embodiment does not increase the cost.

The liquid crystal display of this embodiment is manufactured as follows.

First, a TF as a switching element is placed on a transparent active matrix substrate 43 made of glass or the like.
Semiconductor layers 44 and 45 serving as T and driver monolithic channel regions and source and drain regions are formed in a plane. Then, impurities are implanted into the portions of the semiconductor layers 44 and 45 that will be the source region and the drain region with an ion beam to form n ⁺ portions and p ⁺ portions, respectively. Here, the conductive film on one side for forming the driver capacitor and Cs is simultaneously formed.

Thereafter, a gate insulating film 46 made of silicon nitride or the like was formed on the semiconductor layers 44 and 45 to a thickness of 3000 angstroms by the CVD method. At this time, contact holes are naturally formed on the source and drain regions.

Thereafter, a gate wiring 47 made of aluminum is formed to a thickness of 4000 angstroms by a CVD method and then patterned. At this time, the capacitor and the conductive film on the other side of the Cs portion are simultaneously formed.

Thereafter, an insulating film 46 made of silicon nitride or the like is formed on the gate wiring 47 to a thickness of 3000 angstroms by the CVD method. At this time, contact holes are naturally formed on the source and drain regions.

Next, the source wiring 48 and the drain wiring 49
Is formed to a thickness of 3000 angstroms by CVD and patterned. At the same time, an external input terminal is also formed.

Next, a photosensitive acrylic resin having a thickness of 3 μm is formed as an interlayer insulating film on the source wiring 48 and the drain wiring 49 by a spin coating method. This interlayer insulating film also serves as the insulating film 41 in the driver region.

Since the interlayer insulating film also serves as the insulating film 41, an active matrix substrate can be formed without newly increasing a manufacturing process for forming the insulating film 41. Further, since the insulating film 41 has a low relative dielectric constant and can be easily thickened, the parasitic capacitance of the driver monolithic portion is suppressed, and signal delay and rounding are suppressed. In addition, when an organic resin such as acrylic is used as the material of the insulating film 41, pinholes are less likely to be formed in the insulating film 41.
Leaks are prevented. Further, even when a metal such as aluminum which easily forms a hillock is used for the wiring, the insulating film 41 can be used.
Cover the wiring to prevent hillocks.

When a photosensitive acrylic resin is used,
A photoresist coating step is not required for patterning, which is advantageous in terms of productivity. In the present embodiment, the acrylic resin used as the material of the interlayer insulating film is an acrylic resin colored before application. This is because the acrylic resin colored before application can be easily patterned, and can be made more transparent by subjecting the entire surface to an exposure treatment after panning. Such a transparent treatment of the resin,
Not only can it be done optically, but it can also be done chemically.

Next, on the interlayer insulating film, ITO is applied
After being deposited to a thickness of 00 Å, patterning is performed to form a pixel electrode. At this time, the EMI countermeasure conductive film 42 is formed at the same time. The EMI countermeasure conductive film 42 is also formed on the external input terminal. This makes it possible to form the insulating film 41 that suppresses EMI and protects the monolithic driver without increasing the number of steps. At this time, it is more preferable that the surface of the resin of the interlayer insulating film is roughened by ashing or the like, so that the adhesion between the interlayer insulating film and the pixel electrode and the conductive film 42 is improved.

Thereafter, an alignment film made of polyimide or the like is formed and rubbing is performed. At this time, by forming the interlayer insulating film sufficiently thick (for example, 3 μm), the surface was flattened, and no problem such as disorder in alignment occurred. Thereafter, a liquid crystal is sandwiched between the active matrix substrate and a counter substrate provided with a black matrix, a counter electrode, and a color filter to complete the liquid crystal display device of the fourth embodiment.

In the above manufacturing process, the time during which the monolithic driver is exposed to the substrate surface during the manufacturing process is reduced as compared with the conventional manufacturing process, so that the probability of disconnection due to dust or the like is greatly reduced. And the non-defective rate is greatly improved.

Here, it is needless to say that it is more effective to ground the EMI countermeasure conductive film to the GND wiring.

(Embodiment 5) In the liquid crystal display device of Embodiment 5, the EMI
The countermeasure conductive film is used as a power supply wiring. The power supply wiring formed in the drive region has + 3V, + 5V, + 12V, -8
It has a common wiring to which a DC voltage such as V is applied, and a GND wiring. Since no AC voltage is applied to the common wiring and the GND wiring, these wirings do not cause EMI. Therefore, these wirings can be formed in the EMI countermeasure conductive film.

In the present embodiment, the wiring on the active matrix substrate and the conductive film for EMI countermeasures form a two-layer power supply wiring, so that a reduction in resistance is achieved. If the width of the EMI countermeasure conductive film is made wider, the resistance can be further reduced.

Although the embodiments of the present invention have been described above, it is also possible to use, for example, a color filter or a gate insulating film as an insulating film in addition to the first to fifth embodiments.

The display devices according to the first to fifth embodiments are transmission type active matrix type liquid crystal display devices. However, the display device according to the present invention is not limited to the transmission type active matrix type liquid crystal display device, but may be a reflection type or DUTY type liquid crystal display device. , EL, and plasma display devices.

[0069]

As described above, in the flat display device according to the present invention, EMI can be suppressed with a simple structure. Further, since the insulating film protects the common wiring, the flat display device according to the present invention has high reliability.

Further, by connecting the conductive film to the GND wiring, the suppression of EMI can be further suppressed.

In the method of manufacturing a flat panel display device according to the present invention, EMI can be prevented without increasing the number of steps, and the cost does not increase. In addition, since the common wiring is protected during the manufacturing process, disconnection or the like does not occur, and the non-defective product rate is improved, so that the manufacturing cost is reduced.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a configuration of an active matrix substrate in a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line AA ′ of the liquid crystal display device of FIG.

FIG. 3 is a diagram for explaining the liquid crystal display device according to the second embodiment, and is a cross-sectional view taken along line AA ′ of FIG.

FIG. 4 is a diagram illustrating a liquid crystal display device according to a second embodiment.

5 is a diagram for explaining the liquid crystal display device of Embodiment 3, and is a diagram corresponding to a cross-sectional view taken along line AA ′ of the liquid crystal display device of FIG.

FIG. 6 is a diagram for explaining a drive driver in a liquid crystal display device according to a fourth embodiment.

FIG. 7 is a plan view showing a configuration of an active matrix substrate in a conventional liquid crystal display device.

8 is a sectional view of the liquid crystal display device of FIG. 7 taken along line BB '.

FIG. 9 is a diagram showing a liquid crystal driving device disclosed in Japanese Patent Application Laid-Open No. 6-37478.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 display area 2 common wiring 3 scanning wiring (gate wiring) 4 signal wiring (source wiring) 5 driver 6 bump 7 ACF 8 external input terminal 9 active matrix substrate 10 opposing substrate 11 insulating film 12 conductive film 51 display region 52 common Wiring 53 Scanning wiring (gate wiring) 54 Signal wiring (source wiring) 55 Driving driver 56 Bump 57 ACF 58 External input terminal 59 Active matrix substrate 60 Counter substrate

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-258660 (JP, A) JP-A-4-56924 (JP, A) JP-A-64-55535 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G02F 1/1345

Claims (2)

(57) [Claims] 1. A flat display comprising: a display area in which at least a plurality of scanning lines and a plurality of signal lines are formed; and a driving area in which a driving driver for sending a signal to the scanning line and the signal line is provided. an apparatus, common wiring or before connecting the driver for driving each other
Serial least one common line connecting the driver for driving an external input terminal is covered with the insulating film, is on the insulating film and the conductive film is formed, that the DC voltage is applied to the conductive film Characteristic flat display device. 2. The method according to claim 1, wherein the DC voltage is applied to the common wiring and the power supply.
2. The power supply circuit according to claim 1, which is provided by a GND wiring which is grounded.
4. The flat panel display according to claim 1.