US20020085137A1 - Liquid-crystal display device with improved yield of production and method of fabricating the same - Google Patents
Liquid-crystal display device with improved yield of production and method of fabricating the same Download PDFInfo
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- US20020085137A1 US20020085137A1 US09/347,651 US34765199A US2002085137A1 US 20020085137 A1 US20020085137 A1 US 20020085137A1 US 34765199 A US34765199 A US 34765199A US 2002085137 A1 US2002085137 A1 US 2002085137A1
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- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 43
- 238000004519 manufacturing process Methods 0.000 title description 11
- 238000009413 insulation Methods 0.000 claims abstract description 76
- 239000010409 thin film Substances 0.000 claims abstract description 22
- 239000010408 film Substances 0.000 claims description 72
- 238000000034 method Methods 0.000 claims description 8
- 239000004065 semiconductor Substances 0.000 claims 10
- 239000011521 glass Substances 0.000 description 51
- 229910021417 amorphous silicon Inorganic materials 0.000 description 32
- 239000012535 impurity Substances 0.000 description 10
- 239000002245 particle Substances 0.000 description 10
- 239000002184 metal Substances 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 8
- 238000005530 etching Methods 0.000 description 7
- 238000007789 sealing Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 4
- 229910000542 Sc alloy Inorganic materials 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000000059 patterning Methods 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 125000006850 spacer group Chemical group 0.000 description 2
- 239000000463 material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
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Classifications
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1345—Conductors connecting electrodes to cell terminals
- G02F1/13458—Terminal pads
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
- G02F1/1362—Active matrix addressed cells
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1345—Conductors connecting electrodes to cell terminals
Definitions
- the present invention generally relates to liquid-crystal display devices and methods of fabricating the same, and more particularly to a Thin Film Transistor (TFT) liquid-crystal display device and a method of fabricating the same.
- TFT Thin Film Transistor
- liquid-crystal display devices for use with information processors such as computers are widely used because of their portable size and low power consumption.
- FIG. 1 shows a diagram of a conventional active-matrix-type liquid-crystal display device.
- a liquid-crystal display device 10 includes a first TFT glass base 11 having a plurality of TFTs and transparent pixel electrodes cooperating therewith and a second glass base 12 .
- a liquid-crystal layer 1 between the first TFT glass base 11 and the second glass base 12 is sealed by sealing members.
- the transparent pixel electrode may be selected turned ON through the TFT so that a orienting direction of liquid-crystal molecules is altered by the selected transparent pixel electrode.
- a polarization plate (not shown) is arranged in a cross Nicol state.
- molecule orientation films are provided inside of the TFT glass base 11 and the glass base 12 to suppress orienting directions of liquid-crystal molecules.
- FIG. 2 shows a part of the TFT glass base 11 under magnification.
- a plurality of pad electrodes 11 A supply scan signals and a plurality of scan electrodes 11 a are extend therefrom.
- a plurality of pad electrodes 11 B supply image signals and a plurality of signal electrodes 11 b are extended therefrom.
- the extending direction of the scan electrodes 11 a and that of signal electrodes 11 b cross each other.
- TFTs 11 C are provided at every point of intersection of the scan electrodes 11 a and signal electrodes 11 b .
- a transparent pixel electrode 11 D is provided to each TFT 11 C.
- a row of TFTs 11 C is selected by a scan signal from a corresponding scan electrode 11 a and then a particular transparent pixel electrode 11 D is operated by an image signal from a corresponding signal electrode 11 b.
- FIGS. 3A, 3B, 3 C and 3 D show sectional views illustrating production steps of a conventional liquid-crystal display device.
- every left side shows a display area including a TFT 11 C and every right side shows a terminal area including pad electrodes 11 A and 11 B.
- an Al—Nd or Al—Sc alloy pattern 22 A that is connected to the scan electrode 11 a is formed as a gate electrode 22 A on a glass base 21 corresponding to the first TFT glass base 11 in FIG. 1.
- terminal electrodes 22 B which are made up of an Al—Nd or Al—Sc alloy pattern, corresponding to the pad electrode 11 A or 11 B are formed.
- a gate insulation film 23 A that is made up of SiN is layered over the gate electrode 22 A.
- an n ⁇ type impurity doped amorphous silicon layer 24 A is layered over the gate insulation film 23 A.
- a channel mask film 25 A which is made up of SiN, is formed on an area corresponding to a channel region right above the gate electrode 22 A and is etched.
- an insulation film 23 B which is made up of the same composition (SiN) and thickness as the insulation film 23 A, is layered over the terminal electrodes 22 B and then an amorphous silicon layer 24 B, having the same thickness as the amorphous silicon layer 24 A, is layered over the insulation film 23 B.
- an n + type impurity doped amorphous silicon pattern 26 A is formed on the amorphous silicon layer 24 A and is adjoined with sides of the channel mask film 25 A.
- a metal is layered on the n + type impurity doped amorphous silicon pattern 26 A so that a source-drain of the TFT 11 C is constituted.
- the above metal can be constructed by Ti, Al and Ti layers.
- a mask film 27 A which is made up of SiN, is layered so as to cover over the n + type impurity doped amorphous silicon and metal pattern 26 A and the channel mask film 25 A on the gate insulation film 23 A.
- a contact hole 28 A is provided in the mask film 27 A at one side of the amorphous silicon pattern 26 A.
- a transparent pixel electrode 29 is provided at the contact hole 28 A and contacts the amorphous silicon pattern 26 A. The transparent pixel electrode 29 corresponds to the transparent pixel electrode 11 D in FIG. 2.
- a mask film 27 B corresponding to the mask film 27 A is layered on the insulation film 23 B. Then contact holes 28 B are formed to expose the terminal electrodes 22 B.
- IC devices 56 are connected to the terminal electrodes 22 B via the contact holes 28 B in the terminal area on a display panel 54 by tape automated bonding (TAB) leads (not shown).
- TAB tape automated bonding
- the second glass base covers and seals the display area on the TFT glass base 21 .
- FIG. 5 is a sectional view illustrating the conventional liquid-crystal display device after a cutting step.
- a first glass base 40 corresponding to the first TFT glass base 11 in FIG. 1, has a terminal area 47 including terminal electrodes 22 B and a display area 48 surrounded by the terminal area 47 .
- the first glass base 40 is sealed with a second glass base 49 , sealing members 42 and spacers (not shown) such that the first glass base 40 and the second glass base 49 face each other.
- the terminal area 47 is not covered with the second glass base 49 .
- the terminal area 47 is vulnerable to particles especially during the cutting step. In particular, when terminal electrodes 22 B in the terminal area 47 are damaged mechanically by the particles, the damage makes it impossible to connect the liquid-crystal display to external circuits so that functions as a liquid-crystal display are lost.
- TFT Thin Film Transistor
- a more specific object of the present invention is to provide a Thin Film Transistor (TFT) liquid-crystal display device and a method of fabricating the same that prevent particles from causing mechanical damages and improve yield of production of the same.
- TFT Thin Film Transistor
- a liquid-crystal display device including: a first glass base; a second glass base facing the first glass base in a condition in which a space is defined between the first glass base and the second glass base; a liquid-crystal layer filling the space between the first glass base and the second glass base, and being sealed inside the first glass base, the second glass base and supporting members; a display area that is a surface area of the first glass base and faces the second glass base, and that includes thin-film transistors; a terminal area having terminal electrodes that connect electrically to corresponding thin-film transistors respectively; and projections provided on the terminal area such that heights of the projections are equal to or more than those of the thin-film transistors.
- the projections are provided in the terminal area so as to prevent terminal electrodes from damages caused by particles.
- a method for producing a liquid-crystal display including the steps of: (a) forming a display area having thin-film transistors on a first glass base which surface faces a second glass base; and (b) forming a terminal area having terminal electrodes that connect electrically to the thin-film transistors respectively in a condition in which projections are provided in the terminal area and heights of the projections are substantially equal to or more than those of the thin film transistors.
- the projections are provided during the steps for producing the display area and the terminal area.
- the projections are made up of the same components as the thin-film transistors. Therefore, the projections can be provided without requiring any extra steps or any extra components.
- FIG. 1 shows a diagram of a conventional active-matrix-type liquid-crystal display device
- FIG. 2 shows a part of a TFT glass base 11 under magnification
- FIGS. 3A, 3B, 3 C and 3 D show sectional views illustrating production steps of a conventional liquid-crystal display device
- FIG. 4 shows a diagram illustrating a liquid-crystal display mounting IC devices
- FIG. 5 is a sectional view illustrating the conventional liquid-crystal display device after a cutting step
- FIGS. 6A, 6B, 6 C and 6 D are sectional views illustrating production steps of a liquid-crystal display device according to an embodiment of the present invention.
- FIG. 7 is a sectional view illustrating the liquid-crystal display according to the present invention.
- FIGS. 6A, 6B, 6 C and 6 D are sectional views illustrating production steps of a liquid-crystal display device according to an embodiment of the present invention.
- every left side shows a display area including a TFT 11 C and every right side shows a terminal area including pad electrodes 11 A and 11 B.
- an Al—Nd or Al—Sc alloy pattern 62 A that is connected to the scan electrode 11 a is formed as a gate electrode on a glass base 60 corresponding to the first TFT glass base 11 in FIG. 1.
- terminal electrodes 32 B corresponding to the pad electrode 11 A or 11 B are formed in the same manner as the conventional method.
- a conductive pattern 62 B is formed between the terminal electrodes 32 B as shown in FIG. 6A.
- a gate insulation film 63 A that is made up of SiN is layered over the gate electrode 62 A.
- an n ⁇ type impurity doped amorphous silicon layer 64 A is layered over the gate insulation film 63 A.
- a channel mask film 65 A which is made up of SiN, is formed on an area corresponding to a channel region right above the gate electrode 62 A with patterning.
- an insulation film 63 B which is made up of the same composition and thickness as the insulation film 63 A, is layered over the terminal electrodes 32 B and the conductive pattern 62 B at the same time as the insulation film 63 A is layered.
- an amorphous silicon layer 64 B a thickness of which is the same as that of the amorphous silicon layer 64 A, is layered over the insulation film 63 B at the same time as the amorphous silicon layer 64 A is layered.
- a channel mask film 65 B which is made up of the same composition and thickness as the channel mask film 65 A, is formed at the same time as 65 A is formed.
- an n + type impurity doped amorphous silicon pattern 66 A is formed on the amorphous silicon layer 64 A and is adjoined with both sides of the channel mask film 65 A.
- a metal is layered on the n + type impurity doped amorphous silicon pattern 66 A so that a source-drain of the TFT 11 C is constituted.
- the above metal can be constructed by Ti, Al and Ti layers.
- an n + type impurity doped amorphous silicon pattern 66 B is formed over the channel protection 65 B at the same time as the amorphous silicon pattern 66 A is formed.
- a metal is layered on the n + type impurity doped amorphous silicon pattern 66 B.
- the above metal can be constructed by Ti, Al and Ti layers.
- a mask film 67 A which is made up of SiN, is layered so as to cover over the n + type impurity doped amorphous silicon pattern 66 A, the channel mask film 65 A and the amorphous silicon layer 64 A. Then a transparent pixel electrode 69 A is provided with a contact hole 68 A opened on the amorphous silicon pattern 66 A.
- a mask film 50 B which is made up of SiN, is layered so as to cover over the amorphous silicon layer 66 B and amorphous silicon layer 64 B, and then a transparent pixel electrode 69 B is formed on the mask film 50 B and the amorphous silicon layer 66 B with patterning.
- a contact hole 39 B is provided on each terminal electrode 32 B.
- an etching stopper method in which a channel insulation film is used to protect from etching, is applied.
- a channel etching method in which an over etching is performed to a channel without a channel insulation film, can be applied.
- the conductive pattern 62 B is formed between two terminal electrodes 32 B.
- the amorphous silicon layer 24 B is formed on the insulation film 23 B that is provided on the TFT glass base 21 .
- the mask film 27 B is layered on the amorphous silicon layer 23 B after the etching step.
- a flat surface is formed between the two terminal electrodes 22 B.
- the present embodiment in the terminal area as shown in FIG.
- the conductive pattern 62 B is provided between the terminal electrodes 32 B, and the same films used in the display area are layered on the conductive pattern 62 B simultaneously with the steps performed in the display area. Therefore, the height from a surface of the TFT glass base 60 up to the top of the layers in the terminal area is eventually equal to or more than the height from the surface of the TFT glass base 60 up to the top of the layers at display area.
- the projection fits within a relatively small area of the conductive pattern 62 B. In the same steps for the display area, the projection between the terminal electrodes is provided with the same compositions as the devices on the display area. Therefore, any extra step and particular material for the projection are not required. Moreover, the projection is adjacent to the terminal electrodes so as to protect them from particles.
- a thickness of each film composing the projection is as follows: conductive pattern 62B 200 nm gate insulation film 63B 400 nm amorphous silicon layer 64B 40 nm insulation film 65B 400 nm n + type amorphous silicon 50 nm pattern 66B mask film 50B 300 nm transparent electrode 69B 100 nm
- the thickness of the n + type amorphous silicon pattern 663 includes a thickness of the metal constructed by Ti, Al and Ti layers.
- the total thickness of the projection is approximately 1500 nm (1.5 ⁇ m).
- FIG. 7 is a sectional view illustrating the liquid-crystal display according to the present invention.
- a first glass base 70 having a terminal area 76 including projections 75 and terminal electrodes 32 B and a display area 78 surrounded by the terminal area 76 , and a second glass base 79 are supported by sealing members 72 and spacers (not shown) and face each other.
- the height of the projection 75 provided between two terminal electrodes 32 B is approximately 1.5 ⁇ m.
- a distance between the first glass base 70 and the second glass base 79 is about 2 to 3 ⁇ m.
- devices on the display area can be protected from the particles by sealing with the second glass base and sealing members.
- contact with and damages to surfaces of the terminal electrodes, which are caused by the particles can be eliminated.
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Abstract
Description
- 1. Field of the Invention
- The present invention generally relates to liquid-crystal display devices and methods of fabricating the same, and more particularly to a Thin Film Transistor (TFT) liquid-crystal display device and a method of fabricating the same.
- 2. Description of the Related Art
- Recently, liquid-crystal display devices for use with information processors such as computers are widely used because of their portable size and low power consumption.
- Especially to realize high quality color display, an active matrix method that controls each pixel electrode is widely applied to liquid-crystal display devices.
- FIG. 1 shows a diagram of a conventional active-matrix-type liquid-crystal display device. Referring to FIG. 1, a liquid-crystal display device10 includes a first
TFT glass base 11 having a plurality of TFTs and transparent pixel electrodes cooperating therewith and asecond glass base 12. A liquid-crystal layer 1 between the firstTFT glass base 11 and thesecond glass base 12 is sealed by sealing members. In the liquid-crystal display device 10, the transparent pixel electrode may be selected turned ON through the TFT so that a orienting direction of liquid-crystal molecules is altered by the selected transparent pixel electrode. A polarization plate (not shown) is arranged in a cross Nicol state. Moreover, molecule orientation films are provided inside of theTFT glass base 11 and theglass base 12 to suppress orienting directions of liquid-crystal molecules. - FIG. 2 shows a part of the
TFT glass base 11 under magnification. - Referring to FIG. 2, on the
TFT glass base 11, a plurality of pad electrodes 11A supply scan signals and a plurality of scan electrodes 11 a are extend therefrom. Also, a plurality of pad electrodes 11B supply image signals and a plurality of signal electrodes 11 b are extended therefrom. The extending direction of the scan electrodes 11 a and that of signal electrodes 11 b cross each other. TFTs 11C are provided at every point of intersection of the scan electrodes 11 a and signal electrodes 11 b. Furthermore, a transparent pixel electrode 11D is provided to each TFT 11C. A row of TFTs 11C is selected by a scan signal from a corresponding scan electrode 11 a and then a particular transparent pixel electrode 11D is operated by an image signal from a corresponding signal electrode 11 b. - FIGS. 3A, 3B,3C and 3D show sectional views illustrating production steps of a conventional liquid-crystal display device. In these figures, every left side shows a display area including a TFT 11C and every right side shows a terminal area including pad electrodes 11A and 11B.
- Referring to FIG. 3A, in the display area, an Al—Nd or Al—
Sc alloy pattern 22A that is connected to the scan electrode 11 a is formed as agate electrode 22A on aglass base 21 corresponding to the firstTFT glass base 11 in FIG. 1. Simultaneously, in the terminal area on theglass base 21,terminal electrodes 22B, which are made up of an Al—Nd or Al—Sc alloy pattern, corresponding to the pad electrode 11A or 11B are formed. - Subsequently, in the display area in FIG. 3B, a
gate insulation film 23A that is made up of SiN is layered over thegate electrode 22A. Moreover, an n− type impurity dopedamorphous silicon layer 24A is layered over thegate insulation film 23A. Furthermore, achannel mask film 25A, which is made up of SiN, is formed on an area corresponding to a channel region right above thegate electrode 22A and is etched. - In the terminal area in FIG. 3B, an
insulation film 23B, which is made up of the same composition (SiN) and thickness as theinsulation film 23A, is layered over theterminal electrodes 22B and then anamorphous silicon layer 24B, having the same thickness as theamorphous silicon layer 24A, is layered over theinsulation film 23B. - In addition, in the display area in FIG. 3C, an n+ type impurity doped
amorphous silicon pattern 26A is formed on theamorphous silicon layer 24A and is adjoined with sides of thechannel mask film 25A. Moreover, a metal is layered on the n+ type impurity dopedamorphous silicon pattern 26A so that a source-drain of the TFT 11C is constituted. For example, the above metal can be constructed by Ti, Al and Ti layers. - Subsequently, in the display area in FIG. 3D, a
mask film 27A, which is made up of SiN, is layered so as to cover over the n+ type impurity doped amorphous silicon andmetal pattern 26A and thechannel mask film 25A on thegate insulation film 23A. In addition, acontact hole 28A is provided in themask film 27A at one side of theamorphous silicon pattern 26A. Furthermore, atransparent pixel electrode 29 is provided at thecontact hole 28A and contacts theamorphous silicon pattern 26A. Thetransparent pixel electrode 29 corresponds to the transparent pixel electrode 11D in FIG. 2. - Simultaneously with steps in the display area in FIG. 3D, in the terminal area in FIG. 3D, a mask film27B corresponding to the
mask film 27A is layered on theinsulation film 23B. Thencontact holes 28B are formed to expose theterminal electrodes 22B. As shown in FIG. 4, in a liquid-crystal display device 52,IC devices 56 are connected to theterminal electrodes 22B via thecontact holes 28B in the terminal area on adisplay panel 54 by tape automated bonding (TAB) leads (not shown). - The second glass base covers and seals the display area on the
TFT glass base 21. - Generally, to cut production cost, after a plurality of liquid-crystal displays are produced on a surface of a large glass base, the large glass base is cut into each liquid-crystal display so that a plurality of liquid-crystal display devices are completed.
- FIG. 5 is a sectional view illustrating the conventional liquid-crystal display device after a cutting step. Referring to FIG. 5, a
first glass base 40, corresponding to the firstTFT glass base 11 in FIG. 1, has aterminal area 47 includingterminal electrodes 22B and adisplay area 48 surrounded by theterminal area 47. Thefirst glass base 40 is sealed with asecond glass base 49, sealingmembers 42 and spacers (not shown) such that thefirst glass base 40 and thesecond glass base 49 face each other. Theterminal area 47 is not covered with thesecond glass base 49. Thus, theterminal area 47 is vulnerable to particles especially during the cutting step. In particular, whenterminal electrodes 22B in theterminal area 47 are damaged mechanically by the particles, the damage makes it impossible to connect the liquid-crystal display to external circuits so that functions as a liquid-crystal display are lost. - It is a general object of the present invention to provide a Thin Film Transistor (TFT) liquid-crystal display device and method of the same in which the above-mentioned problems are eliminated.
- A more specific object of the present invention is to provide a Thin Film Transistor (TFT) liquid-crystal display device and a method of fabricating the same that prevent particles from causing mechanical damages and improve yield of production of the same.
- The above objects of the present invention are achieved by a liquid-crystal display device including: a first glass base; a second glass base facing the first glass base in a condition in which a space is defined between the first glass base and the second glass base; a liquid-crystal layer filling the space between the first glass base and the second glass base, and being sealed inside the first glass base, the second glass base and supporting members; a display area that is a surface area of the first glass base and faces the second glass base, and that includes thin-film transistors; a terminal area having terminal electrodes that connect electrically to corresponding thin-film transistors respectively; and projections provided on the terminal area such that heights of the projections are equal to or more than those of the thin-film transistors.
- According to the present invention, the projections are provided in the terminal area so as to prevent terminal electrodes from damages caused by particles.
- The objects of the present invention are also achieved by a method for producing a liquid-crystal display including the steps of: (a) forming a display area having thin-film transistors on a first glass base which surface faces a second glass base; and (b) forming a terminal area having terminal electrodes that connect electrically to the thin-film transistors respectively in a condition in which projections are provided in the terminal area and heights of the projections are substantially equal to or more than those of the thin film transistors.
- According to the present invention, the projections are provided during the steps for producing the display area and the terminal area. In addition, the projections are made up of the same components as the thin-film transistors. Therefore, the projections can be provided without requiring any extra steps or any extra components.
- Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings, in which:
- FIG. 1 shows a diagram of a conventional active-matrix-type liquid-crystal display device;
- FIG. 2 shows a part of a
TFT glass base 11 under magnification; - FIGS. 3A, 3B,3C and 3D show sectional views illustrating production steps of a conventional liquid-crystal display device;
- FIG. 4 shows a diagram illustrating a liquid-crystal display mounting IC devices;
- FIG. 5 is a sectional view illustrating the conventional liquid-crystal display device after a cutting step;
- FIGS. 6A, 6B,6C and 6D are sectional views illustrating production steps of a liquid-crystal display device according to an embodiment of the present invention; and
- FIG. 7 is a sectional view illustrating the liquid-crystal display according to the present invention.
- FIGS. 6A, 6B,6C and 6D are sectional views illustrating production steps of a liquid-crystal display device according to an embodiment of the present invention. In these figures, every left side shows a display area including a TFT 11C and every right side shows a terminal area including pad electrodes 11A and 11B.
- Referring to FIG. 6A, in the display area, an Al—Nd or Al—
Sc alloy pattern 62A that is connected to the scan electrode 11 a is formed as a gate electrode on aglass base 60 corresponding to the firstTFT glass base 11 in FIG. 1. Simultaneously, in the terminal area on theglass base 60,terminal electrodes 32B corresponding to the pad electrode 11A or 11B are formed in the same manner as the conventional method. In addition toterminal electrodes 32B, in this embodiment, aconductive pattern 62B, a thickness of which is the same as that of theterminal electrodes 32B, is formed between theterminal electrodes 32B as shown in FIG. 6A. - Subsequently, in the display area in FIG. 6B, a
gate insulation film 63A that is made up of SiN is layered over thegate electrode 62A. Moreover, an n− type impurity dopedamorphous silicon layer 64A is layered over thegate insulation film 63A. Furthermore, achannel mask film 65A, which is made up of SiN, is formed on an area corresponding to a channel region right above thegate electrode 62A with patterning. - In the terminal area in FIG. 6B, an
insulation film 63B, which is made up of the same composition and thickness as theinsulation film 63A, is layered over theterminal electrodes 32B and theconductive pattern 62B at the same time as theinsulation film 63A is layered. Moreover, anamorphous silicon layer 64B, a thickness of which is the same as that of theamorphous silicon layer 64A, is layered over theinsulation film 63B at the same time as theamorphous silicon layer 64A is layered. Furthermore, achannel mask film 65B, which is made up of the same composition and thickness as thechannel mask film 65A, is formed at the same time as 65A is formed. - In addition, in the display area in FIG. 6C, an n+ type impurity doped
amorphous silicon pattern 66A is formed on theamorphous silicon layer 64A and is adjoined with both sides of thechannel mask film 65A. Moreover, a metal is layered on the n+ type impurity dopedamorphous silicon pattern 66A so that a source-drain of the TFT 11C is constituted. For example, the above metal can be constructed by Ti, Al and Ti layers. - In the terminal area in FIG. 6C, an n+ type impurity doped
amorphous silicon pattern 66B is formed over thechannel protection 65B at the same time as theamorphous silicon pattern 66A is formed. Also, a metal is layered on the n+ type impurity dopedamorphous silicon pattern 66B. For example, the above metal can be constructed by Ti, Al and Ti layers. When the patterning step is performed with etching, an exposed surface area of theamorphous silicon layer 64B under theamorphous silicon pattern 66B is removed. - Subsequently, in the display area in FIG. 6D, a
mask film 67A, which is made up of SiN, is layered so as to cover over the n+ type impurity dopedamorphous silicon pattern 66A, thechannel mask film 65A and theamorphous silicon layer 64A. Then a transparent pixel electrode 69A is provided with a contact hole 68A opened on theamorphous silicon pattern 66A. - Moreover, in the terminal area in FIG. 6D, a mask film50B, which is made up of SiN, is layered so as to cover over the
amorphous silicon layer 66B andamorphous silicon layer 64B, and then a transparent pixel electrode 69B is formed on the mask film 50B and theamorphous silicon layer 66B with patterning. Acontact hole 39B is provided on eachterminal electrode 32B. - In the etching step, an etching stopper method, in which a channel insulation film is used to protect from etching, is applied. Alternately, a channel etching method, in which an over etching is performed to a channel without a channel insulation film, can be applied.
- In this embodiment, during the above-mentioned steps for the terminal area, the
conductive pattern 62B is formed between twoterminal electrodes 32B. In the conventional method, between twoterminal electrodes 22B in the terminal area as shown FIG. 3D, theamorphous silicon layer 24B is formed on theinsulation film 23B that is provided on theTFT glass base 21. Moreover, the mask film 27B is layered on theamorphous silicon layer 23B after the etching step. Thus, a flat surface is formed between the twoterminal electrodes 22B. On the contrary, in the present embodiment, in the terminal area as shown in FIG. 6D, theconductive pattern 62B is provided between theterminal electrodes 32B, and the same films used in the display area are layered on theconductive pattern 62B simultaneously with the steps performed in the display area. Therefore, the height from a surface of theTFT glass base 60 up to the top of the layers in the terminal area is eventually equal to or more than the height from the surface of theTFT glass base 60 up to the top of the layers at display area. In addition, the projection fits within a relatively small area of theconductive pattern 62B. In the same steps for the display area, the projection between the terminal electrodes is provided with the same compositions as the devices on the display area. Therefore, any extra step and particular material for the projection are not required. Moreover, the projection is adjacent to the terminal electrodes so as to protect them from particles. - A thickness of each film composing the projection is as follows:
conductive pattern 62B200 nm gate insulation film 63B400 nm amorphous silicon layer 64B40 nm insulation film 65B 400 nm n+ type amorphous silicon 50 nm pattern 66B mask film 50B 300 nm transparent electrode 69B 100 nm - The thickness of the n+ type amorphous silicon pattern 663 includes a thickness of the metal constructed by Ti, Al and Ti layers.
- The total thickness of the projection is approximately 1500 nm (1.5 μm).
- In this manner, a plurality of liquid-crystal displays having the display area and terminal area are provided on a glass base. Then the glass base is cut into each piece of liquid-crystal display. How the present invention can protect the terminal electrodes from particles caused by cutting the glass base will now be described. FIG. 7 is a sectional view illustrating the liquid-crystal display according to the present invention.
- Referring to FIG. 7, in a liquid-
crystal display device 71, afirst glass base 70, having aterminal area 76 includingprojections 75 andterminal electrodes 32B and adisplay area 78 surrounded by theterminal area 76, and a second glass base 79 are supported by sealingmembers 72 and spacers (not shown) and face each other. - In FIG. 7, the height of the
projection 75 provided between twoterminal electrodes 32B is approximately 1.5 μm. In addition, a distance between thefirst glass base 70 and the second glass base 79 is about 2 to 3 μm. When a size of aparticle 74 caused by cutting glass bases is larger than a specification of a few μm distance between the terminal electrodes, the present invention can prevent the particle from causing contact with and damages to surfaces of the terminal electrodes. - As mentioned above, according to the present invention, devices on the display area can be protected from the particles by sealing with the second glass base and sealing members. In addition, contact with and damages to surfaces of the terminal electrodes, which are caused by the particles, can be eliminated.
- The present invention is not limited to the specifically disclosed embodiments, variations and modifications, and other variations and modifications may be made without departing from the scope of the present invention.
- The present application is based on Japanese Priority Application No. 10-192010 filed on Jul. 7, 1998, the entire contents of which are hereby incorporated by reference.
Claims (7)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP10-192010 | 1998-07-07 | ||
JP19201098A JP4017754B2 (en) | 1998-07-07 | 1998-07-07 | Liquid crystal display device and manufacturing method thereof |
Publications (2)
Publication Number | Publication Date |
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US20020085137A1 true US20020085137A1 (en) | 2002-07-04 |
US6459466B1 US6459466B1 (en) | 2002-10-01 |
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Application Number | Title | Priority Date | Filing Date |
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US09/347,651 Expired - Fee Related US6459466B1 (en) | 1998-07-07 | 1999-07-06 | Liquid-crystal display device with improved yield of production and method of fabricating the same |
Country Status (4)
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US (1) | US6459466B1 (en) |
JP (1) | JP4017754B2 (en) |
KR (1) | KR20000011559A (en) |
TW (1) | TW429367B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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US9575380B2 (en) | 2013-01-23 | 2017-02-21 | Mitsubishi Electric Corporation | Display panel including wiring protection pattern and display device |
Families Citing this family (8)
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US7411211B1 (en) | 1999-07-22 | 2008-08-12 | Semiconductor Energy Laboratory Co., Ltd. | Contact structure and semiconductor device |
KR100656915B1 (en) * | 2000-09-08 | 2006-12-12 | 삼성전자주식회사 | Signal transmission film, control signal part including and liquid crystal display including the film |
KR100715943B1 (en) * | 2001-01-29 | 2007-05-08 | 삼성전자주식회사 | Liquid crystal display device and method for manufacturing the same |
US7858451B2 (en) | 2005-02-03 | 2010-12-28 | Semiconductor Energy Laboratory Co., Ltd. | Electronic device, semiconductor device and manufacturing method thereof |
KR101405607B1 (en) * | 2012-11-27 | 2014-06-10 | 하이디스 테크놀로지 주식회사 | Liquid crystal display panel and manufacturing method thereof |
CN104834143A (en) * | 2015-06-03 | 2015-08-12 | 合肥京东方光电科技有限公司 | Array substrate, preparation method of array substrate and display device |
KR101694851B1 (en) * | 2016-06-14 | 2017-01-10 | 주식회사 코아메디텍 | Brassiere for pressing breast after mastectomy |
CN111025715A (en) * | 2019-12-10 | 2020-04-17 | Tcl华星光电技术有限公司 | Display panel and manufacturing method thereof |
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Publication number | Priority date | Publication date | Assignee | Title |
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JP3009438B2 (en) * | 1989-08-14 | 2000-02-14 | 株式会社日立製作所 | Liquid crystal display |
JPH07104315A (en) * | 1993-09-30 | 1995-04-21 | Sanyo Electric Co Ltd | Liquid crystal display device |
JP2864464B2 (en) * | 1994-12-22 | 1999-03-03 | 日本ビクター株式会社 | Reflective active matrix display panel and method of manufacturing the same |
GB2312543B (en) * | 1995-02-23 | 1999-06-30 | Citizen Watch Co Ltd | Liquid crystal display device and method of producing the same |
JPH08313922A (en) * | 1995-05-19 | 1996-11-29 | Rohm Co Ltd | Liquid crystal display device |
JP3663261B2 (en) * | 1995-10-05 | 2005-06-22 | 株式会社東芝 | Array substrate for display device and manufacturing method thereof |
US5835177A (en) * | 1995-10-05 | 1998-11-10 | Kabushiki Kaisha Toshiba | Array substrate with bus lines takeout/terminal sections having multiple conductive layers |
JP3720134B2 (en) * | 1996-08-29 | 2005-11-24 | シャープ株式会社 | Liquid crystal display device |
TW495635B (en) * | 1997-07-11 | 2002-07-21 | Hitachi Ltd | Liquid crystal display device |
-
1998
- 1998-07-07 JP JP19201098A patent/JP4017754B2/en not_active Expired - Fee Related
-
1999
- 1999-07-06 TW TW088111440A patent/TW429367B/en not_active IP Right Cessation
- 1999-07-06 US US09/347,651 patent/US6459466B1/en not_active Expired - Fee Related
- 1999-07-07 KR KR1019990027375A patent/KR20000011559A/en not_active Application Discontinuation
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9575380B2 (en) | 2013-01-23 | 2017-02-21 | Mitsubishi Electric Corporation | Display panel including wiring protection pattern and display device |
Also Published As
Publication number | Publication date |
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JP2000029061A (en) | 2000-01-28 |
US6459466B1 (en) | 2002-10-01 |
JP4017754B2 (en) | 2007-12-05 |
KR20000011559A (en) | 2000-02-25 |
TW429367B (en) | 2001-04-11 |
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