KR102506079B1 - Pad and display panel and flat display device therewith - Google Patents

Abstract

Disclosed is a pad unit, a display panel and a display device having the same. The disclosed invention includes: a plurality of electrodes provided in an area where a panel and a driving unit are bonded to a panel for electrical connection between the panel and the driving unit; and a protective film provided in a section where no electrode is provided, and at least one of the plurality of electrodes is provided to have a length different from that of other adjacent electrodes.
According to the present invention, the connection between the exposed metal parts of the electrodes is structurally blocked by designing the lengths of the electrodes in the region where there is a high possibility of agglomeration of the conductive balls protruding out of the region where the bonding is performed, thereby reducing the bonding process. It is possible to effectively suppress the occurrence of a short in

Description

Pad and display panel and display device having the same {PAD AND DISPLAY PANEL AND FLAT DISPLAY DEVICE THEREWITH}

The present invention relates to a pad, a display panel and a display device having the same, and more particularly, a pad provided for connecting a display panel and a driver providing a signal for driving the display panel, and a display panel and display having the same. It's about the device.

As we enter the full-fledged information age, the display field that visually expresses electrical information signals has developed rapidly. Device) has been developed and is rapidly replacing the existing cathode ray tube (CRT).

Specific examples of such a flat panel display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), and a flat panel display device such as an organic light emitting diode (OLED). can be heard

Among the above flat panel display devices, an organic light emitting device (hereinafter referred to as “OLED”) is a self-emitting device and can be lightweight and thin because it does not require a backlight used in a liquid crystal display device, which is a non-light emitting device.

In addition, OLED has an excellent viewing angle and contrast ratio compared to liquid crystal display devices, is advantageous in terms of power consumption, can be driven at low DC voltage, has a fast response speed, is resistant to external shocks because the internal components are solid, and has a range of operating temperatures. It also has a wide advantage, and in particular, because the manufacturing process is simple, there is an advantage that the production cost can be reduced more than the existing liquid crystal display.

1 is a diagram schematically showing the structure of a general OLED.

Referring to FIG. 1, the OLED 10 is composed of an array substrate 1 on which driving and switching thin film transistors (DTr and STr) and an organic light emitting diode (E) are formed, and an encapsulation substrate 2 for encapsulation. do.

Here, the array substrate 1 is divided into a display area AA for displaying images and a non-display area NA surrounding the edge of the display area AA. A gate line GL is formed, and a data line DL extending in a second direction crossing the first direction to define the pixel area P along with the gate line GL is formed. A power wiring (PL) is formed to be spaced apart from (DL) and to apply a power voltage.

Further, in each pixel region P, a switching thin film transistor STr connected to the gate line GL and the data line DL is formed at an intersection, and the switching thin film transistor STr is a driving thin film. It is connected to the transistor DTr and the storage capacitor StgC, and the driving thin film transistor DTr is connected between the power line PL and the organic light emitting diode E.

In addition, the data driving unit 30 is formed in the non-display area NA outside the display area AA, and the gate driving unit 20 is formed at one edge perpendicular to the edge where the data driving unit 30 is formed. The pixel area P is divided and scanned.

In addition, a power supply line 40 for supplying power to each electrode of the organic light emitting diode E is formed at the other edge of the non-display area NA perpendicular to the edge where the data driver 30 is formed. The data driving units 20 and 30 and the power supply line 40 process signals provided from the outside through the pad unit PA of the non-display area NA.

A pad electrode (PAD) to be electrically connected to the film-type FPC (60) is formed in the pad portion (PA), and the gate and data driver portions (20, 30) are components that generate various control signals and data signals. It includes a printed circuit board (PCB) to be mounted, and a driving integrated circuit (Driving IC) connected to the OLED and the printed circuit board and applying a signal to the wiring of the OLED.

Here, the driving integrated circuit mounting method is divided into a Tape Automated Bonding (TAB) method and a Chip On Glass (COG) method. These methods are rapidly developing as the use of OLED expands.

In the TAB method, the array substrate 1 and the electrodes of the driving integrated circuit are bonded through an ILB (Inner Lead Bonding) process and an OLB (Outer Lead Bonding) process in which a eutectic alloy connection is made between the film to which the metal wire is attached and the electrode of the driving integrated circuit. method of bonding. The ILB process is a process of connecting film leads and electrodes of the driving integrated circuit with bumps, and the OLB process is a process of bonding the leads of the TAB package bonded to the electrodes to the OLED through the ILB process.

In addition to the TAB method, there is a COG (Chip On Glass) method in which the driver integrated circuit is directly mounted on the array substrate 1 .

The COG method directly adheres the drive integrated circuit to the array substrate 1 only with bumps and an anisotropic conductive film (ACF) without using the film used in the TAB method, and has a simpler structure than the TAB method. It has the advantage of reducing the volume.

The anisotropic conductive film is a material in the form of a double-sided tape in which a heat-hardened adhesive and fine conductive balls are mixed for adhesion and conduction. In general, an anisotropic conductive film is placed between a flexible printed circuit (FPC) type connection board and a pad electrode (PAD) and pressurized at a high temperature using a pressure tool, thereby connecting the pad electrode (PAD) and the electrode of the connection board. They are electrically connected by the conductive balls and physically connected to each other by adhesive.

According to the bonding between the pad part (PA) and the connecting substrate made using such an anisotropic conductive film, the conductive ball pushed out to the end of the pad part (PAD) during the process of pressurization using a pressure tool is applied to the pad part (PA). Agglomeration may occur at the end of (PAD).

In this way, when the conductive balls agglomerate at the end of the pad part PA, the agglomerated conductive balls connect metal parts such as exposed ITO of the pad electrode PAD adjacent to each other, causing a short circuit. This can be.

In addition, generally, the pad electrode PAD is formed so that the interface between the portion covered with the protective layer and the portion exposed to the metal such as ITO forms a straight line, whereas pressure used for bonding between the pad portion PA and the connection substrate is formed. The shape of the boundary surface of the tool does not match this and has a shape in which warpage has occurred to some extent.

As a result, a tolerance is generated between the metal exposed portion of the pad electrode PAD, that is, the area to be pressed by the pressure tool and the area to be pressed by the pressure tool, and due to this, a portion of the pad portion PA is properly bonded. Areas that cannot be achieved arise.

Such bonding defects mainly occur on both sides of the pad part PA, and on both sides of the pad part PA where bonding defects occur, short circuits occur due to aggregation of conductive balls, or In the subsequent cleaning process, the possibility of occurrence of defects due to the cleaning agent penetrating through both sides of the pad part PA increases.

The present invention relates to a pad having an improved structure and a display panel and a display having the same to suppress short circuit or bonding failure due to aggregation of electrode balls in a bonding process between a pad and a connecting substrate using a pressure tool. Its purpose is to provide a device.

A pad according to one aspect of the present invention includes: a plurality of electrodes provided in an area where the display panel and the drive unit are bonded to the display panel for electrical connection between the display panel and the drive unit; and a protective film provided in a section where the electrode is not provided, wherein at least one of the plurality of electrodes is provided to have a length different from that of the other adjacent electrodes.

In addition, a display panel according to another aspect of the present invention includes: a display area provided with wires for defining pixels; a non-display area provided to surround the display area; and a plurality of pads provided in an area in the non-display area where the non-display area and the drive unit are bonded for electrical connection between the wiring and the driver, the pads being arranged along a width direction of the pad. a plurality of electrodes; and a protective film provided in a section where the electrode is not provided, wherein at least one of the plurality of pads includes the electrode having a length different from that of the electrode of another adjacent pad, or a plurality of the electrodes provided on the pad. At least one of them is provided to have a length different from that of the other adjacent electrodes.

Also, a display device according to another aspect of the present invention includes: a driving unit generating a signal transmitted to a wire defining a pixel; and a display area provided with the wiring, a non-display area provided to surround the display area, and an area where the non-display area and the driving unit are bonded to the non-display area for electrical connection between the wiring and the driving unit. A display panel including a plurality of pads provided on a display panel, wherein the pads include: a plurality of electrodes arranged along a width direction of the pads; and a protective film provided in a section where the electrode is not provided, wherein at least one of the plurality of pads has the electrode having a length different from that of the electrode of another adjacent pad or a plurality of the electrodes provided on the pad. At least one of them is provided to have a length different from that of the other adjacent electrodes.

According to the pad of the present invention, and the display panel and display device including the pad, the lengths of the electrodes in the area where the agglomeration of the conductive balls protruding out of the area where bonding is made are differentiated and the exposed metal parts of the electrode are separated. By structurally blocking the connection, it is possible to effectively suppress the occurrence of a short during the bonding process.

In addition, the present invention differentially designs the length of electrodes for each pad so that all of the electrodes to be bonded are included in the pressing area of the pressing tool, so that short circuits occur due to bonding defects or bonding defects occur on the side of the pad during the bonding process. It provides an effect of enabling efficient bonding while suppressing the bonding.

1 is a diagram schematically showing the structure of a general OLED.
2 is a diagram illustrating a separated state of a display panel and a driving unit of a display device according to an embodiment of the present invention.
3 is a diagram illustrating a coupled state of a display panel and a driving unit of a display device according to an embodiment of the present invention.
4 is a cross-sectional view schematically showing a coupling structure of a display panel and a driving unit of a display device according to an embodiment of the present invention.
5 is a view showing a first example of a pad according to an embodiment of the present invention.
FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5 .
7 is a view showing a second example of a pad according to an embodiment of the present invention.
8 is a view showing a third example of a pad according to an embodiment of the present invention.
9 is a view showing a fourth example of a pad according to an embodiment of the present invention.
10 is a view showing a fifth example of a pad according to an embodiment of the present invention.

Hereinafter, an embodiment of a pad according to the present invention, a display panel including the same, and a display device will be described with reference to the accompanying drawings. For convenience of description, thicknesses of lines or sizes of components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of a user or operator. Therefore, definitions of these terms will have to be made based on the content throughout this specification.

FIG. 2 is a view showing a separated state of a display panel and a driver of a display device according to an embodiment of the present invention, and FIG. 3 shows a coupled state of a display panel and a driver of a display device according to an embodiment of the present invention. it is a drawing 4 is a cross-sectional view schematically showing a coupling structure of a display panel and a drive unit of a display device according to an embodiment of the present invention, and FIG. 5 is a view showing a first example of a pad according to an embodiment of the present invention, 6 is a cross-sectional view along line VI-VI of FIG. 5;

Referring to FIGS. 2 to 4 , a display device 300 according to an embodiment of the present invention includes a driving unit 100 and a display panel 200 .

The driver 100 generates a signal transmitted to a wire L for defining a pixel. The driving unit 100 includes substrates 110 and 120 having circuit patterns and a driving IC (not shown) mounted on the substrates 110 and 120 .

The substrates 110 and 120 include an S-PCB 110 on which a driving integrated circuit is mounted, and a COF 120 connecting the S-PCB 110 and the display panel 200 .

The S-PCB 110 is a single-layer or multi-layered wiring pattern, and a hard printed circuit board (PCB), which is difficult to bend or fold, is applied, or a flexible, flexible It may be provided in a form to which a flexible printed circuit board (FPCB) is applied.

The COF 120 is provided with a single layer or multiple layers of wiring patterns, and is provided in a form in which a chip is mounted on a film that can be bent or folded by itself.

The display panel 200 includes a display area 210 where an image is displayed, and a non-display area 220 provided to surround the display area 210 .

In the display area 210, various types of wiring, for example, a plurality of gate lines GL and data lines DL for defining a pixel area, and a power line (not shown) for applying a power voltage may be provided. .

Also, the non-display area 220 is a portion on which an image is not displayed, and corresponds to a border portion surrounding the display area 210 .

In the non-display area 220, an extension line LL extending from the wiring of the display area 210 to the non-display area 220, and a pad to which the COF 120 of the driver 100 and the extension line LL are connected. 230 is provided.

The pad 230 is provided in the non-display area 220, provided in an area provided for electrical connection between wiring and the driver 100, that is, an area where bonding between the non-display area 220 and the COF 120 is made. do.

A plurality of electrodes 231 are provided on the pad 230, and an extension line LL extending a wiring of the display area 210 to the non-display area 220 is connected to each electrode 231 provided as described above. .

In the non-display area 220 , a plurality of pads 230 are spaced apart at predetermined intervals along the width direction or length direction of the display panel 200 . In each pad 230, a plurality of electrodes 231 are disposed spaced apart from each other by a predetermined interval along the direction in which the plurality of pads 230 are arranged.

Each electrode 231 is made of a conductive material that can be electrically connected by contacting the wiring of the COF 120, and in this embodiment, each electrode 231 is illustrated as being made of a transparent electrode material such as ITO.

A passivation layer 233 is covered on the pad 230 and is formed in a section where the plurality of electrodes 231 are not provided. The protective layer 233 may be formed by depositing or coating an insulating material such as silicon oxide (SiO 2 ) on a region of the display panel 200 where the pad 230 is provided.

The pad 230 formed as described above may be electrically connected to the driving unit 100 through an anisotropic conductive film 150 .

The anisotropic conductive film 150 may be provided in a form including an insulating film and a conductive ball, and is disposed between the electrode 231 of the pad 230 and the COF 120 .

The connection work between the driver 100 and the pad 230, that is, the bonding work, is carried out by a pressing tool in a state where the anisotropic conductive film 150 is placed between the electrode 231 of the pad 230 and the COF 120. As the (T) is pressed at a high temperature, the electrode 231 of the pad 230 and the electrode of the COF 120 are physically connected to each other by an insulating film and electrically connected by a conductive ball. .

Referring to FIG. 5 , the pad 230 is provided in a form divided into a conductive region (A) in which a plurality of electrodes 231 are formed and an insulating region (B) covered with a protective film 233. The conductive region (A) At least one of the plurality of electrodes 231 forming the is provided to have a different length from the other adjacent electrodes 231.

That is, the pad 230 includes a plurality of electrodes 231 , and includes at least one electrode 231 whose length is different from that of another adjacent electrode 231 .

In this embodiment, each electrode 231 is exemplified as being formed to have a length different from that of other adjacent electrodes 231 .

During bonding to form a connection between the drive unit 100 and the pad 230, a conductive ball is placed at the end of the electrode 231, that is, in the area where bonding is performed, during the process of pressurization using a pressurizing tool (T; see FIG. 7). A phenomenon of being pushed out may occur.

In this way, the conductive balls pushed out to the outside of the bonding area can be united at the protruded position to connect the exposed metal parts of the two adjacent electrodes 231, which causes a short circuit at the electrode 231 part of the pad 230. may be the cause of it.

According to this embodiment, since all of the electrodes 231 are formed to have a different length from the other adjacent electrodes 231, even if the conductive balls are agglomerated at the end of one of the electrodes 231, due to this, the two adjacent electrodes (231) will not be connected to each other.

That is, as shown in FIGS. 5 and 6, even if the agglomeration of the conductive balls occurs and the exposed metal part of any one electrode 231 is connected to the agglomerated conductive ball at the corresponding position, any one electrode ( The conductive ball connected to the exposed metal portion of 231) only contacts the protective film 233 of the insulating region B, and is not connected to the exposed metal portion.

As the connection between the two adjacent electrodes 231 by the agglomerated conductive balls is blocked, it is possible to structurally block the occurrence of a short circuit due to the agglomerated conductive balls.

7 is a view showing a second example of a pad according to an embodiment of the present invention, and FIG. 8 is a view showing a third example of a pad according to an embodiment of the present invention. 9 is a view showing a fourth example of a pad according to an embodiment of the present invention, and FIG. 10 is a view showing a fifth example of a pad according to an embodiment of the present invention.

According to the display panel 200a as shown in FIG. 7 , one of the plurality of pads 230a includes a plurality of electrodes 231 having a different length from the electrodes 231 provided on the other adjacent pads 230a. A dog pad 230d is provided.

Compared to the above-described embodiment in which the lengths of two adjacent electrodes 231 within one pad are differentially designed, in this embodiment, the length of the electrodes 231 for each pad 230a is differentially designed. do.

As an example, the display panel 200a is arranged so that the outermost pad 230a along the pad arrangement direction includes the electrode 231 having a shorter length than the electrodes 231 provided on the other pads 230a. It may be provided in a form including a plurality of pads 230a.

In the bonding process between the pad 230a and the COF 120, the pressure using the pressure tool T may be performed for each area where each pad 230a is located, but usually one pressure tool T is provided on the display panel. Most of the plurality of pads 230a are made in the form of applying pressure to the entirety.

In order to effectively bond the pad 230a and the COF 120 (see FIG. 4 ), the pressure tool T used for bonding the pad 230a and the COF 120 includes a plurality of electrodes provided on the pad 230a. (231) It should be provided in a form that can cover the entire area.

Considering the characteristics of a bonding operation in which the pad 230a and the COF 120 are pressed at once only by the upward and downward movement of the pressing tool T, the pressing tool T is partially attached to the electrode 231 or the electrode 231. This is because when provided in a form that does not cover a part of, the corresponding part is out of the pressing area of the pressing tool (T) so that bonding of the corresponding part is not properly performed, which may cause bonding failure.

Therefore, the pressure tool T used for bonding between the pad 230a and the COF 120 has a boundary surface between the conductive region A and the insulating region B on the plurality of electrodes 231 provided on the pad 230a. It is provided to form a shape consistent with the shape connecting the boundary line (hereinafter referred to as the "conductive section boundary line") between the boundaries or to form a form slightly protruding from the boundary line toward the insulation section (B).

However, in actual work sites, due to tolerances generated during the manufacturing process, storage, and use of the pressure tool T, it frequently occurs that the shape of the interface of the pressure tool T has a somewhat warped shape. , In this case, it is common that the interface of the pressure tool T is curved in a convex shape at its center.

The boundary surface of the pressure tool T is relatively concave in the direction from the boundary line of the conductive section to the conductive section A, compared to the central portion where the end portion located on the outer side along the electrode arrangement direction is convex. .

Considering this, in the present embodiment, the pad 230a disposed at the outermost part along the pad arrangement direction includes the electrode 231 having a shorter length than the electrode 231 provided on the other pads 230a ( 230a) constitutes the electrode 231 arrangement structure.

Through this, since the entirety of the plurality of electrodes 231 provided on the pad 230a can be included in the pressing area of the pressing tool T, there is no bonding area between the pad 230a and the COF 120. Bonding can be effectively performed.

As another example, the display panel 200b, as shown in FIG. 8, has a pad 230b disposed on a side biased in one direction along the pad arrangement direction, more specifically, on a side biased toward the outer side along the pad arrangement direction. It may be provided in a form including a plurality of pads 230b arranged to include electrodes 231 having shorter lengths than electrodes 231 provided on other pads 230b.

At this time, the electrodes 231 included in each pad 230b are formed to have a different length from the electrodes 231 included in the other adjacent pads 230b, but have the same length within the same pad 230b. can be formed

In this case, since the shape of the electrode 231 only needs to be changed for each pad 230b, the shape of the electrode 231 can be formed relatively easily.

As another example, as shown in FIG. 9 , in the plurality of electrodes 231 respectively provided on the plurality of pads 230c provided in the display panel 200c, the conduction section boundary line is the boundary of the pressure tool T. It may be provided in a form that forms a shape corresponding to the shape and is connected.

That is, each of the plurality of electrodes 231 provided on the plurality of pads 230c is provided with a length such that the boundary line of the conductive section is connected in a shape corresponding to the shape of the boundary surface of the pressure tool T.

According to the form provided in this way, since the forming area of the conductive section A is more similar to the pressing area of the pressure tool T, the entirety of the plurality of electrodes 231 provided on the pad 230c is the pressure tool ( T) is more likely to be completely included in the pressing area, so that bonding between the pad 230c and the COF 120 (see FIG. 4) can be more effectively achieved.

As an example, the plurality of electrodes 231 respectively provided on the plurality of pads 230c may be provided so that the boundary line of the conductive section is connected in a stepped shape.

That is, a length difference of more than a predetermined length between each electrode 231 provided on the pad 230c and another electrode 231 adjacent thereto, for example, a length difference of more than the size of the conductive balls gathered at the end side of the electrode 231, An arrangement state of the electrodes 231 provided on the pad 230c may be determined.

As the shape of the pad 230a and the electrodes 231 provided thereon are determined in this way, the exposed metal parts of the two adjacent electrodes 231 are located at positions spaced apart by a distance greater than or equal to the size of the agglomerated conductive balls. Due to the connection of the electrode 231 by the ball, it is possible to more effectively suppress the occurrence of a short circuit.

As another example, as shown in FIG. 10 , in the plurality of electrodes 231 provided on the plurality of pads 230d provided in the display panel 200d, the conductive section boundary line has a curved shape of “∪” shape. It may be arranged to form and connect.

In this case, since each end of the plurality of electrodes 231 forms a continuous curved shape, the operation of forming the shape of the plurality of electrodes 231 can be performed relatively easily.

According to the pad as described above, and the display panel and display device including the same, the lengths of the electrodes 231 in the region where the probability of aggregation of the conductive balls protruding out of the region where bonding is made are differentiated, and the electrodes 231 By structurally blocking the connection between the exposed metal parts, it is possible to effectively suppress the occurrence of a short during the bonding process.

In addition, according to the pad of the present invention and the display panel and display device having the same, the length of the electrode 231 for each pad is set so that the entire electrode 231 to be bonded can be completely included in the pressing area of the pressing tool T. By differentially designing, there is an effect of enabling efficient bonding while suppressing the occurrence of a short due to a bonding failure or a bonding failure on the side of the pad during the bonding process.

The present invention has been described with reference to the embodiments shown in the drawings, but this is only exemplary, and those skilled in the art can make various modifications and equivalent other embodiments. will understand Therefore, the true technical protection scope of the present invention should be determined by the claims below.

100: driving unit
110: S-PCB
120: COF
130: driving integrated circuit
150: anisotropic conductive film
200,200a,200b,200c,200d : Display panel
210: display area
220: non-display area
230,230a,230b,230c,230d: pad
231: electrode
233: protective film
A: Challenge area
B: Insulation area
L: Wiring
LL: extension line
T : Pressing tool

Claims (8)

a plurality of electrodes provided in an area where the display panel and the driving unit are bonded to the display panel for electrical connection between the display panel and the driving unit; and
A protective film partially disposed on the plurality of electrodes;
Ends of the plurality of electrodes are located on the same line, the plurality of electrodes have an insulating section in which the protective film is disposed and a conductive section in which the protective film is not disposed, and the length of at least one conductive section among the plurality of electrodes is A pad, different from the length of the conductive section of the other adjacent said electrode.
According to claim 1,
A pad in which the length of the conductive region of each said electrode is different from the length of the conductive region of the adjacent other said electrode.
According to claim 1,
The plurality of electrodes are provided so that the length of the conductive section of the electrode becomes shorter toward the outer side along the arrangement direction of the plurality of electrodes.
a display area in which wires for defining pixels are provided;
a non-display area provided to surround the display area; and
A plurality of pads provided in an area where the non-display area and the drive unit are bonded in the non-display area for electrical connection between the wiring and the drive unit;
the pad,
a plurality of electrodes arranged along the width direction of the pad; and
A protective film partially disposed on the plurality of electrodes;
Ends of the plurality of electrodes are located on the same line, and the plurality of electrodes have an insulating region in which the protective film is disposed and a conductive region in which the protective film is not disposed,
A display panel comprising: electrodes having a length of a conductive section shorter than a length of a conductive section of the electrodes included in other pads as the pad is disposed on a side inclined toward an outer side along an arrangement direction of the plurality of pads.
delete delete delete a driving unit generating signals transmitted to wires defining pixels; and
A display area provided with the wiring, a non-display area provided to surround the display area, and an area where the non-display area and the driving unit are bonded to the non-display area for electrical connection between the wiring and the driving unit. Including a display panel including a plurality of pads provided,
the pad,
a plurality of electrodes arranged along the width direction of the pad; and
A protective film partially disposed on the plurality of electrodes;
Ends of the plurality of electrodes are located on the same line, and the plurality of electrodes have an insulating region in which the protective film is disposed and a conductive region in which the protective film is not disposed,
A display device comprising: electrodes having a length of a conductive section shorter than a length of a conductive section of the electrodes included in other pads as the pad is disposed on a side inclined toward an outer side along an arrangement direction of the plurality of pads.

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