KR102651854B1 - Display Panel - Google Patents

Abstract

The present invention provides a flexible display panel that can prevent deformation or damage due to heat by providing a protective pattern made of metal on a flexible substrate made of plastic.
In addition, the present invention provides a display panel that has an inspection pattern on a flexible substrate, allowing easy identification of a location impacted by an external force.

Description

Display Panel {Display Panel}

The present invention relates to a display panel, in which a display area is provided at the center of a flexible display panel and a non-display area is provided at the edge.

As the information society develops, the demand for display devices for displaying images is increasing in various forms, and various types of display devices such as liquid crystal display devices, plasma display devices, and organic light emitting display devices are being used.

Additionally, among display devices, mobile devices such as smart phones and tablets, and medium to large-sized devices such as smart televisions provide touch-based input processing according to user convenience and device characteristics.

And as research on foldable display devices that can be folded or unfolded, or rollable display devices that can be rolled up or unfolded, is being conducted, technology for flexible plastic display panels is growing.

However, while the plastic display panel of these display devices has the advantage of being thin, light, and flexible, it is easily damaged by small external forces during the manufacturing process such as lifting, moving, and aligning the display panel, and the location of the damage must be determined. It has a problem that is difficult to do. In addition, since the display panel is made of plastic, it is weak to heat and is easily deformed during heat treatment, so it is time to develop technology to overcome the limitation.

The present invention aims to solve this problem, and more specifically, the purpose of the present invention is to provide a display panel that can prevent the flexible display panel from being easily damaged or deformed in a process that requires heat treatment.

In order to solve this problem, the present invention provides a flexible display panel that can prevent deformation or damage due to heat by providing a protective pattern made of metal on a flexible substrate made of plastic.

In addition, the present invention provides a display panel that has an inspection pattern on a flexible substrate, allowing easy identification of a location impacted by an external force.

According to the flexible display panel of the present invention,

First, by providing a protective pattern on the flexible substrate, it is possible to prevent the substrate from being deformed due to thermal deformation in the LLO process.

Second, this prevents the distance between alignment marks from expanding due to thermal deformation.

Third, there is no increase in manufacturing time because the protection pattern or inspection pattern is not performed in a separate process.

Fourth, the inspection pattern has the effect of shortening the time to inspect the location of disconnections or cracks caused by external forces.

Figure 1 is a partial enlarged view showing a state in which a protection pattern is provided at the edge of a display panel according to a first embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view showing the protection pattern of the display panel shown in FIG. 1.
Figure 3 is a cross-sectional view showing another embodiment according to the protection pattern of the present invention.
Figure 4 is a perspective view showing a state in which a test pattern is provided on a display panel according to a second embodiment of the present invention.
Figure 5 (a) is a reference diagram showing the amount of elongation and stress due to thermal expansion of a substrate without a conventional protection pattern, and Figure 5 (b) is a reference diagram showing the amount of elongation and stress due to thermal expansion of a substrate provided with a protection pattern of the present invention. This is a reference diagram indicating stress.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily implement them. It should be noted that the drawing numbers indicated on the configuration in the attached drawings are the same as possible when indicating the same configuration in other drawings. Additionally, in describing the present invention, if it is determined that a detailed description of a related known function or known configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Additionally, some features presented in the drawings are enlarged, reduced, or simplified for ease of explanation, and the drawings and their components are not necessarily drawn to appropriate scale. However, those skilled in the art will easily understand these details.

Figure 1 is a partial enlarged view showing a state in which a protection pattern is provided at the edge of the display panel according to the first embodiment of the present invention, and Figure 2 is an enlarged cross-sectional view showing the protection pattern of the display panel shown in Figure 1. am.

Referring to Figures 1 and 2, the display panel 110 according to the first embodiment of the present invention includes a flexible substrate 111 and a protection pattern 120.

First, the display panel 110 displays an image through a pixel array in which subpixels are arranged in a matrix form. The basic pixel may be composed of at least three subpixels capable of expressing white by mixing colors among white (W), red (R), green (G), and blue (B) subpixels. For example, basic pixels include subpixels of R/G/B combination, subpixels of W/R/G combination, subpixels of B/W/R combination, and subpixels of G/B/W combination. or may be composed of subpixels of a W/R/G/B combination.

In addition, it is equipped with a power supply unit and uses an input voltage to generate and output various driving voltages required for display devices such as a timing controller, gate driver, data driver, and display panel. For example, the power supply includes the driving voltage of the digital circuit supplied to the data driver and timing controller, the driving voltage of the analog circuit supplied to the data driver, and the gate-on voltage (gate high voltage) and gate-off voltage used in the gate driver. (gate low voltage) etc. are generated and supplied. The power supply unit generates a plurality of driving voltages (EVDD, EVSS) and reference voltages required when driving the display panel and supplies them to the display panel through a data driver.

The timing controller receives image data and basic timing control signals from an external system. The system may be any one of a computer, a TV system, a set-top box, or a portable terminal such as a tablet or mobile phone. Basic timing control signals may include a dot clock, data enable signal, vertical synchronization signal, horizontal synchronization signal, etc.

The timing controller provides data control signals and gate control that controls the driving timing of the data driver and gate driver, respectively, using basic timing control signals supplied from the outside and timing setting information (start timing, pulse width, etc.) stored in the internal register. Signals are generated and supplied.

The flexible substrate 111 can be bent, bent, twisted, folded, or rolled by external force. For example, the display panel may be a display panel manufactured on a thin, flexible substrate that can be bent, bent, folded, or rolled like paper, while maintaining the display characteristics of a conventional flat panel display.

To implement a flexible display device, the substrate may include glass or polyimide (PI). In addition, any material that has insulating properties and is flexible, such as PEN (Polyethylene Naphthalate) or PET (Polyethylene Terephthalate), can be used. Additionally, the substrate may be made of either a transparent or opaque material.

The flexible substrate 111 may be a wiring board on which the first electrode is disposed, and therefore the first electrode may be located on the substrate. The insulating layer may be disposed on the substrate where the first electrode is located, and the auxiliary electrode may be located in the insulating layer. In this case, an insulating layer is stacked on a substrate to form a single wiring board. More specifically, the insulating layer is made of an insulating and flexible material such as polyimide (PI), PET, or PEN, and can be integrated with the substrate to form one substrate.

And the display panel 110 includes a display area (AA) where an image is implemented and a non-display area (NA) where the image is not displayed, and the protective pattern 120 is formed in the non-display area (NA) in the process of printing these electrodes. NA) can be printed on

As shown in FIG. 2, the protection patterns 120 are arranged side by side on both edges of the flexible substrate 111. At this time, the substrate 111 has a substantially rectangular shape and includes long sides on both sides with long sides and short sides on both sides with short sides, and the long sides and short sides are arranged in a perpendicular direction to each other.

At this time, the protection pattern 120 includes an inner pattern 121 arranged long along the long side direction D1, an outer pattern 123 arranged side by side on the outside of the inner pattern 121, and an inner pattern 121 and an outer pattern. It includes a connection pattern (122) connecting (123).

That is, protection patterns 120 are disposed along the longitudinal direction on the long sides facing each other on both sides of the flexible substrate 111. At this time, the protection pattern 120 on one side of the substrate is the inner pattern 121 and the connection pattern. (122) and the outer pattern (123). Accordingly, the same protection pattern 120 is provided on the other side of the substrate 111.

At this time, because more thermal deformation occurs in the flexible substrate 111 toward the long side direction D1, it is preferable that the protection pattern 120 is disposed in the long side direction D1 to prevent this. A protective pattern can be provided in both water and short-sided directions.

The protection pattern 120 may have a connection pattern 122 connecting the inner pattern 121 and the outer pattern 123 in a honeycomb pattern structure. The honeycomb pattern structure is applied to a structure that absorbs shock because hexagonal holes are formed and the specific compressive strength is extremely high. In addition, since the inner pattern 121 and the outer pattern 123 are arranged side by side in the long side direction D1, thermal deformation can be sufficiently reduced in the laser lift off (Laser Lift Off (LLO)) process.

Although not shown in the drawing, the inner pattern 121 is formed to have a smaller width or thickness than the outer pattern 123 so that the outer pattern 123 disposed on the outermost edge of the flexible substrate 111 is more resistant to thermal deformation. can be designed.

In addition, in the flexible substrate 111, the position of the alignment mark (AM) may shift due to thermal deformation during the LLO process, and the protection pattern 120 prevents the error from gradually increasing due to this. There may also be possible effects.

Figure 3 is a cross-sectional view showing another embodiment according to the protection pattern of the present invention.

In Figure 3, another embodiment of the protection pattern 220 is shown, and a plurality of protection patterns 220 are arranged side by side on one side of the flexible substrate 111.

That is, the protection pattern 220 is provided with an inner protection pattern (220a) and an outer protection pattern (220b) side by side, and each protection pattern includes an inner pattern (221), a connection pattern (222), and an outer pattern (223). do. Therefore, compared to the protection pattern of the first embodiment described above, there is an effect of being able to withstand tensile stress more firmly. Here, tensile stress represents a state in which an external force acts in the direction in which the flexible substrate is stretched by heat.

Although not shown in the drawing, the protection pattern 220 has been described as having a pair of structures arranged with an inner protection pattern 220a and an outer protection pattern 220b. However, a plurality of protection patterns may be arranged side by side. In addition, patterns (not shown) may be provided between the inner protection pattern 220a and the outer protection pattern 220b to connect them in the long side direction, short side direction, or diagonal direction.

Figure 4 is a perspective view showing a state in which an inspection pattern is provided on a flexible display panel according to a second embodiment of the present invention.

Referring to FIG. 4, the flexible display panel 310 according to the second embodiment of the present invention includes an inspection pattern 311 in the non-display area (NA). The inspection pattern 311 may be made in the same process as the protection pattern of the first embodiment described above. Additionally, when the inspection pattern 311 is provided together with the protection pattern, it is preferably disposed outside the protection pattern.

In the inspection pattern 311, a first long-side inspection area 311a and a second long-side inspection area 311b are placed on both long-side edges of the flexible substrate 111, and a short-side inspection area 311c is placed on the short-side edge. do. Therefore, the test pattern 311 is largely divided into a first long-side test area 311a, a second long-side test area 311b, and a short-side test area 311c. At this time, as shown in FIG. 4, the short side inspection area 311c cannot be located in the portion where the pad area PA of the flexible substrate 111 is disposed, so it is located on the short side opposite to the pad area PA. .

And the inspection pattern 311 includes a first pattern 321 disposed in a portion where the long side and the short side are adjacent within the first long side inspection area 311a, and a second pattern 321 located in the center of the first long side inspection area 311a. It includes a pattern 322 and a third pattern 323 opposite to the first pattern 321 centered on the second pattern 322, and a fourth pattern 324 is located in the short-side inspection area 311c. A fifth pattern 325 is located in a portion where the long side and the short side are adjacent within the second long side inspection area 311b, and a sixth pattern 326 is located in the center of the second long side inspection area 311b. And, it includes a seventh pattern 327 facing the opposite side of the fifth pattern 325 centered on the sixth pattern 326.

In each of the first to seventh patterns 321 to 327, resistance lines connected to each other are arranged side by side along the edges of the flexible substrate 111. The resistance line has a roughly parallelogram shape, and both ends are connected to a sensor unit (not shown) that detects disconnection or cracks through a pad unit (PA). For example, the first patterns 321 to 7th patterns 327 are each connected to the sensor unit, and when a disconnection or crack is suspected due to an impact on one part, the first patterns 321 to 7th patterns ( 327) By examining the resistance of adjacent patterns, it is possible to determine whether a disconnection or crack has occurred. Of course, as the number of patterns increases, more precise disconnection or crack locations can be detected, but the number of patterns is not limited to this. In addition to the parallelogram shape, the resistance line can be applied in various shapes as long as it has a structure that can detect the location of a disconnection or crack in the first to seventh patterns 321 to 327.

In FIG. 4 , resistance lines are positioned so as to overlap each other, like facing parallelograms, between the fifth pattern 325 and the sixth pattern 326.

One of the first to seventh patterns 321 to 327 and the other adjacent pattern are arranged to overlap each other in a direction D2 perpendicular to the edge length direction.

In other words, the direction (D2) perpendicular to the edge direction can be judged as the direction (D2) in which the external force flows, and if the resistance line is not placed in at least one part of the direction (D2)3 in which the external force flows, the external force Since there are parts where disconnection cannot be determined, the patterns are arranged so that at least some areas overlap between them so that there is no resistance line between one pattern and the other and the empty space can be minimized or deleted.

Therefore, when a drivetrain defect occurs due to a disconnection or crack, it is possible to shorten the time to check and inspect it.

Figure 5 (a) is a reference diagram showing the amount of elongation and stress due to thermal expansion of a substrate without a conventional protection pattern, and Figure 5 (b) is a reference diagram showing the amount of elongation and stress due to thermal expansion of a substrate provided with a protection pattern of the present invention. This is a reference diagram indicating stress.

Referring to Figure 5, in the conventional structure as shown in (a), the elongation amount was 0.11139 mm and the stress level was 8.7735 Mpa, and as shown in (b), the display panel of the present invention had an elongation amount of 0.079977 mm and a stress level of 1.9106 Mpa. appeared.

Therefore, it can be confirmed that the length change and stress in the long side direction are significantly reduced by the protection pattern of the present invention.

Therefore, according to the flexible display panel of the present invention, by providing a protective pattern on the flexible substrate, it is possible to prevent the substrate from being deformed due to thermal deformation in the LLO process, thereby preventing the distance between alignment marks from being expanded or contracted due to thermal deformation. This can be prevented, and since the protection pattern or inspection pattern is not performed in a separate process, there is no increase in manufacturing time, and the inspection pattern has the effect of shortening the time to inspect the location of disconnection or cracks caused by external force.

In the above, specific embodiments have been described with reference to the drawings to illustrate the technical idea of the present invention. However, the present invention is not limited to the same configuration and effect as the specific embodiments as described above, and various modified examples are within the scope of the present invention. It can be implemented within the limits of . Therefore, such modifications should also be considered to fall within the scope of the present invention, and the true technical protection scope of the present invention should be determined by the technical spirit of the patent claims described later.

110: display panel
120, 220: Protection pattern
130: Inspection pattern

Claims (12)

A flexible substrate formed to be long along the long side and divided into a display area and a non-display area disposed around the display area; and
A protection pattern provided in the non-display area on the upper surface of the flexible substrate and provided along the long side direction,
The flexible substrate includes long sides that have a first length and are located on both sides facing each other, and short sides that are arranged in a direction perpendicular to the long side and have a second length shorter than the first length and are located on both sides facing each other; ,
The protection pattern includes an inner pattern disposed along the first longitudinal direction of the long side, an outer pattern disposed outside the inner pattern, and a connection pattern connecting the inner pattern and the outer pattern in a honeycomb structure. Display panel. In claim 1,
The protection pattern is,
A display panel arranged side by side on both edges of the flexible substrate. delete delete In claim 1,
A display panel in which the inner pattern has a smaller width or thickness than the outer pattern. In claim 1,
The protection pattern is,
A plurality of display panels arranged side by side on one edge of the flexible substrate. In claim 1,
The display panel further includes an inspection pattern provided in the non-display area on the upper surface of the flexible substrate and provided outside the protection pattern. In claim 7,
The test pattern is,
A first long side inspection area, a second long side inspection area, respectively disposed at the long side edges facing each other, and
A display panel divided into at least one short-side inspection area disposed at an edge of the short-side. In claim 8,
The test pattern is,
A first pattern in which the first long-side inspection area and the second long-side inspection area are adjacent to the short-side inspection area within the first long-side inspection area and the second long-side inspection area, respectively;
A second pattern corresponding to the center portion of the first long side inspection area and the second long side inspection area,
A display panel each including a third pattern located opposite to the first pattern with respect to the second pattern. In claim 9,
The first pattern, second pattern, and third pattern are,
Includes one or a plurality of interconnected resistance lines arranged side by side along the length direction of the edge of the flexible substrate within each set inspection area,
A display panel wherein the resistance line and other adjacent resistance lines are arranged to overlap each other in a direction perpendicular to the longitudinal direction of the edge. A flexible substrate formed to be long along the long side and divided into a display area and a non-display area disposed around the display area; and
A plurality of inspection patterns provided in the non-display area on the upper surface of the flexible substrate and arranged to be spaced apart from each other along the long side direction,
The flexible substrate includes long sides that have a first length and are located on both sides facing each other, and short sides that are arranged in a direction perpendicular to the long side and have a second length shorter than the first length and are located on both sides facing each other; ,
Each of the plurality of inspection patterns includes an inner pattern disposed along the first longitudinal direction of the long side, an outer pattern disposed outside the inner pattern, and a connection pattern connecting the inner pattern and the outer pattern in a honeycomb structure. A display panel comprising: In claim 11,
The display panel further includes a protection pattern provided in the non-display area on the upper surface of the flexible substrate and disposed inside the inspection pattern.