JPH11109886A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a counter electrode connection part for conducting and connecting between substrates from being exposed to outdoor air and to prevent a connection terminal from being disconnected by electric corrosion by providing the counter electrode connection part at the inner part hermetically sealed with an adhesive. SOLUTION: A TFT substrate 1 and a counter substrate 2 are stuck through a thin gap by seal material 3 provided at the periphery, and hermetically sealed by a sealing material 32 after liquid crystal is injected from an injection hole 31 in space between the substrates 1 and 2. The counter electrode signal input terminal 81 of a common electrode 7 is formed continuously to the array of input terminals 8 on the substrate 1. A 1st counter electrode connection terminal 83 is provided in an inside area from the material 3 on the substrate 1, and connected to the counter electrode signal input terminal through a leading wire 82. Meanwhile, a part of the electrode 7 is led out to the vicinity of the corner part of the substrate 2 in the inside area from the material 3, and set as a 2nd counter electrode connection terminal 71. The terminals 83 and 71 are connected by the conductive adhesive 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a display device using an optical member such as a liquid crystal.

[0002]

2. Description of the Related Art A set of substrates on which predetermined electrode wirings are formed is attached with a small gap, and a liquid crystal is sealed in the small gap to constitute a capacitor using a liquid crystal as a dielectric layer as a display pixel. A liquid crystal display device (LCD) or an organic EL display device using an organic electroluminescence (EL) whose light emission amount can be controlled by a current amount as a display element has advantages of small size, thinness, and low power consumption. In the field of equipment, practical use as a display has been promoted. In particular, in an LCD, an active matrix type in which a thin film transistor (TFT) is formed as a switching element to control writing and holding of a display signal voltage in each display pixel capacitor can perform high-definition display. Has become.

FIG. 5 is a plan view of a conventional liquid crystal display device. (1) TFT substrate located on the other side of the paper,
(2) is a counter substrate located in front of the sheet, and (3) is a TFT.
A sealing material for bonding the substrate (1) and the counter substrate (2), and is made of a thermosetting adhesive such as an epoxy resin.
Between the TFT substrate (1) and the opposing substrate (2), there is a slit supported by a spacer (not shown), and the sealing material (3) is partially cut away to form an injection hole (31). It has become. Liquid crystal is injected into the internal gap from the injection hole (31), and the injection hole (31) is sealed with a sealing material (32).

The TFT substrate (1) is formed by forming a TFT using polycrystalline silicon (p-Si) as a channel layer on a substrate. On the substrate (1), a plurality of gate lines (GL) and drain lines (DL) crossing each other are formed, and pixels TF formed at these crossings are formed.
A display region (4) composed of a pixel electrode (PX) connected to T (SE) and a pixel TFT (SE), and a gate for supplying a scanning signal to the pixel TFT (SE) around the display region (4). A driver (5) and a drain driver (6) for supplying a display signal voltage to the pixel TFT (SE) in synchronization with scanning by the gate driver (5) are formed. These drivers (5, 6) are displayed in the display area (4)
And a CMOS composed of a p-Si TFT having the same structure as that of the CMOS. Since the operation speed of the p-Si TFT is sufficiently fast,
As described above, not only the pixel TFT (SE) but also a peripheral driver for driving the pixel TFT (SE) can be configured, and a driver-incorporated LCD in which the driver is formed in a display panel is realized. (8) is a signal input terminal of these drivers (5, 6), to which an FPC equipped with a signal processing circuit is connected.

The counter electrode (2) has a common electrode (7) integrally formed corresponding to the display area (4). The display pixel capacitance is such that the liquid crystal and the common electrode (7) are
X). A part of the common electrode (7) is drawn out to a corner of the counter substrate (2) to serve as a second counter electrode connection terminal (71). Also, TF
The T-substrate (1) is provided with a counter electrode signal input terminal (81) for the common electrode (7), and is formed in a region corresponding to the second counter electrode connection terminal (71) by a lead wire (82). The first and second counter electrode connection terminals (71, 83) are connected to a conductive material formed by mixing conductive particles in a resin as an adhesive. They are connected by an adhesive (9) to form a counter electrode connecting portion.

FIG. 6 shows a structure of a pixel TFT (SE) formed on a TFT substrate (1). On the substrate (10),
In the TFT substrate (1) such as Cr, Ta, Ti, etc., a gate electrode (11) made of a first conductive layer having a relatively moderate resistance is formed, and a gate insulating material made of SiNx or / and SiO2 or the like is covered thereover. A film (12) is formed. On the gate insulating film (12), p-Si (13) is formed. The p-Si (13) has a gate electrode (1
Lightly doped (LD) regions (LD) containing impurities such as phosphorus and arsenic at a low concentration using an implantation stopper (14) of SiO2 or the like patterned in the shape of 1).
D), and source and drain regions (S, D) which also contain impurities at a high concentration are formed outside thereof. Immediately below the injection stopper (14) is an intrinsic layer containing substantially no impurities, and is formed in a channel region (CH).
It has become. These p-Si (13) are covered with Si
An interlayer insulating film (15) made of Nx or the like is formed, and a TFT substrate (1) made of Al, Mo, or the like is formed on the interlayer insulating film (15).
A source electrode (16) and a drain electrode (17) made of a second conductive layer having a relatively low resistance are formed therein, and each of the source region (16) and the drain region (17) is formed through a contact hole formed in the interlayer insulating film (15). S) and the drain region (D). On the entire surface covering this TFT, SOG (SPIN
ON GLASS), BPSG (BORO-PHOSPHO SILICATE GLAS
S), a flattening insulating film (18) such as an acrylic resin is formed. An ITO (indi) is formed on the planarizing insulating film (18).
um tinoxide) and a liquid crystal driving pixel electrode (1) comprising a third conductive layer having relatively high resistance in the TFT substrate (1).
9) is formed, and is connected to the source electrode (16) via a contact hole formed in the planarizing insulating film (18).

FIG. 6 shows a pixel TFT (SE) provided in a display region and connected to a pixel electrode (19), in which the source / drain and LD regions (S, D, LD) are doped. Is an N-ch TFT using an element exhibiting an N-type conductivity such as phosphorus or arsenic as an impurity, but in the peripheral portion, an N-ch TFT having a similar structure is used.
In addition, a CMOS is formed by P-ch TFTs using boron or the like as source and drain regions (S, D) to constitute drivers (5, 6).

FIG. 7 is an enlarged sectional view of the vicinity of the counter electrode connecting portions (71, 83, 9). The substrate (1) which is the TFT substrate (1)
0) and a substrate (20), which is the opposing substrate (2), are bonded together with a small gap, and are bonded at their ends with a sealing material (3). Liquid crystal is sealed inside the substrate (10), the substrate (20) and the sealing material (3). A connection end pedestal (21) made of the same first conductive layer as the gate electrode (11) of the TFT, that is, Cr, is formed on the end of the substrate (10) in order to enhance the adhesion to the substrate. I have. On this, it is mainly composed of the same second conductive layer as the source and drain electrodes (16, 17) of the TFT, that is, Al.
As shown in FIG. 5, a lead line (82), which has been bypassed between layers by the same first conductive layer as that of the gate electrode (11), ie, Cr, is isolated from the outside air as shown in FIG. From (81), the sealing material (3) is once drawn inward, is again drawn out of the sealing material (3), and forms a connection end (27) integrated therewith. The gate insulating film (12) and the interlayer The connection is made through a contact hole formed in the insulating film (15). Furthermore, since it is exposed on this side to establish a connection with the counter electrode side, in order to enhance resistance to outside air, a connection end made of the same third conductive layer as the pixel electrode (19), that is, ITO is used. A contact film (29) is formed, and a planarizing insulating film (1) is formed.
8) through the contact hole opened in the connection end (2)
7). These connection end pedestal (21), connection end (27), and connection end contact film (29) constitute a first counter electrode connection terminal (83).

The other substrate (20) which is the opposite substrate (2)
A second counter electrode connecting terminal (71) integral with the common electrode (7) made of ITO is formed on the end of the sealing material (3) by being drawn out from the inner region to the outer region. Thus, the counter electrode connection portions (71, 83, 9) are provided outside the sealing material (3).

[0010]

As can be seen from FIGS. 5 and 7, the first counter electrode connecting terminal (83) and the second counter electrode connecting terminal (71) are sealed inside by a sealing material (3). It is formed by being pulled out from the outside. That is, the counter electrode connecting portions (71, 83, 9) are in a state of being exposed to the outside air. For this reason, in the first counter electrode connection terminal (83), a connection end contact film (29) made of highly resistant ITO is connected to the connection end (27) so that the connection end (27) made of low-resistance Al is not exposed to the outside. 27) It has a structure coated on top. That is, Al having low resistance and suitable for wiring but having low resistance is not exposed to moisture, foreign matter and the like.

However, Al and ITO are extremely liable to cause a battery reaction, and if there is a case where the film coverage is poor at any one place, the connection end contact film (29) is still required for a long time. Moisture penetrates from the gap between the metal and the flattening insulating film (18) to cause an electric contact, and Al is melted as shown by X in FIG. Once such melting corrosion has begun, the speed of melting increases, and the connection end (27) may be disconnected from the lead wire (82), increasing the resistance of the counter electrode connection and furthermore, the problem of poor connection of the counter electrode. Will be invited.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and includes a pixel electrode for modulating an optical member and a transistor element for supplying a display signal voltage to the pixel electrode. A first substrate, a second substrate on which a common electrode for modulating an optical member is formed, a peripheral adhesive for bonding these two substrates at a peripheral edge, the first substrate, the second substrate and the second substrate. An optical member sandwiched by the adhesive; a signal input terminal of the common electrode provided in an outer region of the adhesive on the first substrate; and a lead wire provided on the first substrate. A first connection terminal connected to the signal input terminal, a second connection terminal provided on the second substrate and connected to the common electrode,
In a display device having a conductive adhesive for conductively connecting the first connection terminal and the second connection terminal, the display device includes a first connection terminal, a second connection terminal, and the conductive adhesive. The counter electrode connecting portion is provided inward from the peripheral edge adhesive, and the lead-out line is formed from at least a relatively low-resistance second conductive layer partially bypassed between layers by a relatively middle-resistance first conductive layer. And the first connection terminal is configured to include at least the second conductive layer integrated with the wiring.

[0013] In particular, the first connection terminal is formed on the second conductive layer by the same third electrode as the pixel electrode having relatively high resistance.
Is formed by laminating the conductive layers. Thus, the second conductive layer constituting the counter electrode connection portion exposed on the first substrate is prevented from being exposed to the outside air inside the space sealed by the adhesive, so that the first connection terminal is electrically connected. Disconnection due to touch is prevented.

A first substrate on which a pixel electrode for modulating an optical member and a transistor element for supplying a display signal voltage to the pixel electrode are formed, and a common electrode for modulating the optical member are formed. And the second substrate
A peripheral adhesive for bonding a plurality of substrates at a peripheral edge;
A substrate, an optical member sandwiched between the second and the adhesives, a signal input terminal of the common electrode provided in an outer region of the adhesive on the first substrate, A first connection terminal provided on the second substrate and connected to the signal input terminal by a lead wire; a second connection terminal provided on the second substrate and connected to the common electrode; and the first connection terminal. And a conductive adhesive for conductively connecting the second connection terminal and the second connection terminal. In the display device, the first connection terminal, the second connection terminal, and the counter electrode connection portion including the conductive adhesive are provided. The lead wire is provided outside the peripheral edge adhesive, and a part of the lead wire is a relatively medium resistant first wire.
A connection line formed of at least a relatively low-resistance second conductive layer bypassed between layers by the conductive layer, and the first connection terminal is formed of at least the same first conductive layer as the wiring line It is.

[0015] In particular, the leading wire mostly passes through the inside from the peripheral adhesive and is drawn out of the adhesive near the counter electrode connecting portion and connected to the first connection terminal. The structure is such that an interlayer connection is made from the second conductive layer to the first conductive layer integral with the first connection terminal in the vicinity of the counter electrode connecting portion inside the adhesive.

In particular, the first connection terminal is formed on the first conductive layer by the same third electrode as the pixel electrode having relatively high resistance.
Is formed by laminating the conductive layers. This increases the resistance of the counter electrode connection exposed to the outside,
Disconnection of the first connection terminal due to electric contact is prevented.

[0017]

FIG. 1 is a plan view of a liquid crystal display according to an embodiment of the present invention. (1) is p-SiT
A plurality of gate lines (GL) and drain lines (DL) intersected with each other on a TFT substrate on which an FT is formed.
A display area (4) in which pixel electrodes (PX) and pixel TFTs (SE) connected to the pixel electrodes (PX) are arranged in a matrix at intersections with the pixel electrodes (PX), and pixel TFTs (SE) around the display area (4)
A gate driver (5) and a drain driver (6). These drivers (5, 6) are constituted by CMOS inverters of TFTs having the same structure as the pixel TFT (SE). Substrate (1)
Are provided with signal input terminals (8) of these drivers (5, 6). Further, (2) is a counter substrate on which a common electrode (7) is formed, and the TFT substrate (1) and the counter substrate (2) are adhered to each other with a gap by a sealing material (3) provided on the periphery. Injection hole (3
Liquid crystal is injected from 1) and sealed with a sealing material (32).

On the TFT substrate (1), a counter electrode signal input terminal (81) of the common electrode (7) is formed continuously with the arrangement of the input terminals (8). Then, the first counter electrode connection terminal (83) is a sealing material (3) on the TFT substrate (1).
It is provided in a region inside the inner side and is connected to a counter electrode signal input terminal (81) by a lead wire (82). On the other hand, a part of the common electrode (7) is drawn out near the corner of the substrate (2) in a region inside the sealing material (3) to serve as a second counter electrode connection terminal (71). . These first
Counter connection terminal (83) and second counter connection terminal (71)
Is connected by a conductive adhesive (9) in which conductive particles obtained by applying gold plating to particles of glass fiber, plastic, or the like are mixed in a resin as an adhesive.

FIG. 2 is an enlarged cross-sectional view of the vicinity of the counter electrode connecting portion made of the first counter electrode connecting terminal (83), the second counter electrode connecting terminal (71), and the conductive adhesive (9). On the edge of the substrate (10), which is the TFT substrate (1), the same as the gate electrode (11) of the TFT having relatively medium resistance in the TFT substrate (1) in order to enhance the adhesion to the substrate. A first conductive layer, that is, a connection end pedestal (21) made of Cr is formed thereon, on which the source and drain electrodes (16, 17) of a TFT having relatively low resistance in the TFT substrate (1) are mainly formed.
And a connection end (2) integral with the lead-out line (82) which has been bypassed between layers by Cr as the first conductive layer at a wiring intersection (not shown).
7) a gate insulating film (12) and an interlayer insulating film (15)
Are connected via contact holes opened in the holes. Furthermore, since it is exposed on the substrate surface in order to establish a connection with the counter electrode side, a relatively high resistance pixel electrode (19) is provided in the TFT substrate (1) in order to increase the resistance. And a connection end contact film (29) made of the same third conductive layer, ie, ITO, is formed.
8) through the contact hole opened in the connection end (2)
7). The connection end pedestal (21), the connection end (27) and the connection end contact film (29) constitute a first counter electrode connection terminal (83).

The other substrate (20) which is the opposite substrate (2)
A second counter electrode connecting terminal (71) is integrally formed from the common electrode (7) made of ITO. These two substrates (10, 20) are opposed to each other with a small gap, are adhered to each other by a sealing material (3) and are bonded together, and the inner thin portion hermetically sealed by these substrates (10, 20) and the sealing material (3). Liquid crystal (10) in the gap
Is sealed.

In the present invention, as is clear from FIGS. 1 and 2, the first counter electrode connection terminal (83) on the TFT substrate (1) (10) side and the second counter electrode connection terminal (83) on the counter substrate (2) (20) side. The counter electrode connecting portion (71) and the counter electrode connecting portion made of a conductive adhesive (9) for connecting the first counter electrode connecting terminal (83) and the second counter electrode connecting terminal (71) are made of a sealing material (3). ), And a lead-in wire (8) drawn from the counter electrode input terminal (81) to the inside of the sealing material (3).
2) is connected to the counter electrode input terminal (81). For this reason, especially, the connection end (27) made of low-resistance Al constituting the first counter electrode connection terminal (83) is not exposed to the outside air, and the contact end (27) is melted and corroded by the electric contact. ) Is prevented from breaking.

Further, as another embodiment, the first counter electrode connection terminal (83) can be constituted only by the connection end (27), or only by the connection end (27) and the connection end pedestal (21). It is. Also in this case, since the first counter electrode connection terminals (27, 21) are provided inside the space sealed by the sealing material (3), the connection ends (27) made of Al are exposed on the substrate (10). Even if the connection is made, it does not come into contact with the outside air, and disconnection of the connection end (27) due to electric contact is prevented. Further, the resistance at the counter electrode can be reduced by not using the connection end contact film (29) made of ITO having a relatively high resistance.

FIG. 3 is a plan view of a liquid crystal display according to a second embodiment of the present invention. In the present embodiment, the first counter electrode connection terminal (84) is provided outside the seal member (3), and is once drawn into the region inside the seal member (3) from the counter electrode signal input terminal (81), Again, the leading wire (82) drawn out of the sealing material (3)
Is connected to the counter electrode signal input terminal (81).
Further, the second counter electrode connection terminal (71) is also integrally pulled out from the common electrode (7) outside the sealing material (3). That is, the first and second counter electrode connection terminals (8
4, 71) and a counter electrode connecting portion made of a conductive adhesive material (9) for connecting them are provided in a region outside the sealing material (3).

FIG. 4 is an enlarged sectional view showing the vicinity of the first counter electrode connecting terminal (84). The substrate (1) which is the TFT substrate (1)
A connection end (31) made of a first conductive layer, i.e., Cr, is formed on the end of the substrate (0). Since the connection end (31) is exposed on the substrate surface for connection with the counter electrode side, In order to increase the resistance to the outside air, the same third conductive layer as the pixel electrode (19), that is, the connection end contact film (2) made of ITO is used.
9) is formed, and is connected to the connection end (31) through contact holes formed in the gate insulating film (12), the interlayer insulating film (15), and the planarizing insulating film (18).
The connection end (31) and the connection end contact film (29)
Constitutes a first counter electrode connection terminal (84).
The lead line (82) is mainly composed of the second conductive layer or A
1 and is routed to the edge of the substrate (10) by the first conductive layer, that is, Cr, at the wiring intersection (not shown), and is routed to the edge of the substrate (10) again. The lead wire (41) made of the first conductive layer is connected to the lead wire (41) through the contact hole opened in (15), and is further led out integrally to the outside of the sealing material (3) to be connected to the leading end (31). It has become.

In the present invention, the counter electrode connecting portions (71, 8)
4, 9) are provided in a region outside the sealing material (3). That is, the first counter electrode connection terminal (84) is exposed to the outside air, and is easily contaminated by moisture, foreign matter, and the like. However, the first counter electrode connection (84)
Is a connection end (31) made of a first conductive layer that is more resistant to Al, that is, Cr, and a connection end contact film (2) made of a third conductive layer that is made of ITO, which is more resistant, that covers the connection end (31).
Because of the configuration of 9), no electric contact is caused, and the disconnection of the connection end (31) is prevented.

Further, according to the present invention, the interlayer connection between the leading line (82) made of the lower resistance second conductive layer and the leading line (41) made of the higher resistance first conductive layer is formed. As shown in FIG. 4, it is provided in a sealed area inside from the sealing material (3). For this reason, the second conductive layer having low resistance does not come into contact with the outside air, and it is possible to prevent the lead-out wirings (82, 41) from being disconnected by the electric contact. In addition, such a lead line (3
Although the interlayer connection of (4, 41) is provided inside the sealing material (3) in the drawing, the present invention is not limited to this, and is provided in a region immediately below the sealing material (3). It is also possible. Also in this case, the routing line (8
The goal of 2) is isolated from the outside air to prevent illumination.

Further, in the present invention, the counter electrode connecting portions (84, 7)
Since (1) and (9) can be provided outside the sealing material (3), the degree of freedom in layout design is increased.

[0028]

According to the present invention, in a display device comprising a pair of electrode substrates whose peripheral edges are bonded by an adhesive with an optical member interposed therebetween, a counter electrode connecting portion for electrically connecting the substrates is sealed by the adhesive. Since the counter electrode connecting portion is provided inside, the counter electrode connecting portion does not come into contact with the outside air, and disconnection of the counter electrode connecting terminal due to electric contact is prevented.

Further, since the counter electrode connecting portion is formed of the same conductive layer as the electrode having relatively high resistance, disconnection of the counter electrode connecting terminal due to electric contact can be prevented. Further, since the counter electrode connecting portion can be provided outside the adhesive, the degree of freedom in wiring design is increased.

[Brief description of the drawings]

FIG. 1 is a plan view of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 3 is a plan view of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a main part of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 5 is a plan view of a conventional liquid crystal display device.

FIG. 6 is a partial cross-sectional view of a conventional liquid crystal display device.

FIG. 7 is a partial cross-sectional view of a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 TFT substrate 2 Counter substrate 3 Sealing material 4 Display area 5 Gate driver 6 Drain driver 7 Common electrode 8 Input terminal 9 Conductive adhesive material 31 Injection hole 71 Second counter electrode connection terminal 82, 83, 84 First counter electrode connection terminal

Claims (5)

[Claims] A first substrate on which a pixel electrode for modulating the optical member and a transistor element for supplying a display signal voltage to the pixel electrode are formed; and a common electrode for modulating the optical member is formed. A second substrate, a peripheral adhesive for bonding these two substrates at a peripheral edge, an optical member sandwiched between the first substrate, the second and the adhesive, and A signal input terminal of the common electrode provided in an outer region of the adhesive; a first connection terminal provided on the first substrate and connected to the signal input terminal by a lead wire; A display device comprising: a second connection terminal provided on a substrate and connected to the common electrode; and a conductive adhesive material for conductively connecting the first connection terminal and the second connection terminal. A first connection terminal, the second connection terminal; The connection terminal and the counter electrode connecting portion made of the conductive adhesive are provided inside from the peripheral adhesive, and the lead-out line is at least relatively low, at least partly bypassed between layers by a relatively moderately resistant first conductive layer. The display device, comprising: a second conductive layer having resistance; and the first connection terminal being composed of the second conductive layer integrated with at least the wiring. 2. The method according to claim 1, wherein the first connection terminal is formed by laminating a third conductive layer, which is the same as the pixel electrode having relatively high resistance, on the second conductive layer. The display device according to claim 1. 3. A first substrate on which a pixel electrode for modulating an optical member and a transistor element for supplying a display signal voltage to the pixel electrode are formed, and a common electrode for modulating the optical member is formed. A second substrate, a peripheral adhesive for bonding these two substrates at a peripheral edge, an optical member sandwiched between the first substrate, the second and the adhesive, and A signal input terminal of the common electrode provided in an outer region of the adhesive; a first connection terminal provided on the first substrate and connected to the signal input terminal by a lead wire; A display device comprising: a second connection terminal provided on a substrate and connected to the common electrode; and a conductive adhesive material for conductively connecting the first connection terminal and the second connection terminal. A first connection terminal, the second connection terminal; The counter electrode connecting portion made of a continuation terminal and the conductive adhesive is provided outside the peripheral edge adhesive, and at least a part of the lead-out line is detoured between layers by a first conductive layer having relatively moderate resistance. A display device, wherein the first connection terminal is connected by a lead line made of a second conductive layer having extremely low resistance, and the first connection terminal is made of the same first conductive layer as at least the lead line. 4. The leading wire is mostly passed inside from the peripheral adhesive and is led out of the adhesive near the counter electrode connection portion to be connected to the first connection terminal. And an interlayer connection from the second conductive layer to the first conductive layer integral with the first connection terminal near the counter electrode connection portion inside the adhesive. Item 3. The display device according to Item 3. 5. The first connection terminal is characterized in that a third conductive layer, which is the same as the pixel electrode having relatively high resistance, is laminated on the first conductive layer. The display device according to claim 3 or 4, wherein