阅读说明：本技术 一种tft阵列基板及其显示面板 (TFT array substrate and display panel thereof ) 是由 明星 曹中涛 于 2019-08-12 设计创作，主要内容包括：本发明提供了一种TFT阵列基板,其定义有显示区和弯折区。其包括衬底层和设置于其上的功能层,其中所述功能层中包括有绝缘层和金属层。其中所述弯折区的所述功能层中通过开深孔设置有填充层,所述金属层在所述弯折区包括第一金属层、第二金属层和第二栅极层。其中所述第一金属层设置在所述填充层的侧端部上,并通过过孔与所述第二栅极层相接；其中所述第二金属层设置在位于所述第一金属层的外侧位置的所述绝缘层上。本发明提供了一种TFT阵列基板,其弯折区采用新的金属层走线结构设计,避免了其第一金属层在所述弯折区的走线经过OILD填充层的两孔开口之间,从而有效的降低其后续因过度蚀刻而断线的风险。(The invention provides a TFT array substrate, which is defined with a display area and a bending area. The metal-based touch screen comprises a substrate layer and a functional layer arranged on the substrate layer, wherein the functional layer comprises an insulating layer and a metal layer. And the functional layer of the bending region is provided with a filling layer through a deep hole, and the metal layer comprises a first metal layer, a second metal layer and a second gate layer in the bending region. Wherein the first metal layer is disposed on the lateral end portions of the fill layer and meets the second gate layer through vias; wherein the second metal layer is disposed on the insulating layer at a position outside the first metal layer. The invention provides a TFT array substrate, wherein a bending area of the TFT array substrate adopts a new metal layer routing structure design, so that the situation that the routing of a first metal layer in the bending area passes through two hole openings of an OILD filling layer is avoided, and the risk of line breakage caused by over-etching in the follow-up process is effectively reduced.)

1. a TFT array substrate is defined with a display area and a bending area; the metal-based touch screen comprises a substrate layer and a functional layer arranged on the substrate layer, wherein the functional layer comprises an insulating layer and a metal layer; wherein a filling layer is arranged in the functional layer of the bending region through the deep hole, wherein the filling layer also extends outwards from the side end of the upper opening thereof to the side end of the edge of the deep hole;

The metal layer comprises a first metal layer, a second metal layer and a second gate layer in the bending region, wherein an insulating layer in the functional layer is arranged among the second gate layer, the first metal layer and the second metal layer;

wherein the first metal layer is disposed on the lateral end portions of the fill layer and meets the second gate layer through vias; wherein the second metal layer is disposed on the insulating layer at a position outside the first metal layer.

2. The TFT array substrate of claim 1; the metal layer further comprises a first gate layer in the bending region, a gate insulating layer is arranged between the first gate layer and the second gate layer, and the insulating layer arranged between the second gate layer and the first metal layer is an interlayer dielectric layer.

3. The TFT array substrate of claim 2; the insulating layer arranged between the first metal layer and the second metal layer is a first flat layer, and a part of the interlayer dielectric layer is covered under the side end part of the filling layer.

4. The TFT array substrate of claim 2; wherein the second metal layer is connected to the first gate layer by a via.

5. The TFT array substrate of claim 4; the second metal layer is connected with the transit metal layer through a via hole, and the transit metal layer is connected with the first grid layer through a via hole.

6. The TFT array substrate of claim 1; the functional layer of the bending region further comprises a buffer layer, the buffer layer is arranged on the substrate layer, and the filling layer penetrates through the buffer layer downwards and enters the substrate layer.

7. The TFT array substrate of claim 6; wherein the substrate layer comprises a PI layer and a barrier layer disposed thereon, wherein the bottom of the filler layer passes through the barrier layer to a surface of the PI layer.

8. The TFT array substrate of claim 1; the metal-clad laminate is characterized in that the insulating layer between the first metal layer and the second metal layer in the bending area is a first flat layer, and the second metal layer is covered with a second flat layer.

9. A display panel; characterized in that it comprises a TFT array substrate according to claim 1.

10. a display panel according to claim 9; wherein the display panel is a flexible AMOLED display panel.

Technical Field

The invention relates to the technical field of flat panel display, in particular to a TFT array substrate and a display panel thereof.

Background

As is known, with the continuous development of display technology, flat panel display devices have become mainstream display devices in the market. Among them, the OLED (Organic Light-Emitting Diode) display panel developed in the industry has been widely used due to its advantages of Light weight, self-luminescence, wide viewing angle, low driving voltage, high Light-Emitting efficiency, low power consumption, and fast response speed, and is considered to be a next-generation mainstream display panel replacing the liquid crystal display panel.

further, in addition to the above advantages, the OLED display device has a particularly important characteristic, i.e., bendability. This flexible feature has made it an absolute advantage in portability, and thus, has been the focus of research and development in the industry.

Taking the flexible folded AMOLED as an example, the adopted LTPS process flow generally includes 10-15 processes, which is 2-3 Mask process steps more than the rigid AMOLED. The extra process steps are mainly to etch the inorganic thin film functional layer with poor stress and poor flexibility in the non-displayed bending area at the periphery by photoetching and Dry process to form two deep holes (DH1, DH2) which are communicated up and down, and then fill the deep holes with organic PI materials with good flexibility to form a filling layer (OILD), thereby being beneficial to the bending property of the inorganic thin film functional layer.

As shown in fig. 5 and 6, a schematic structural diagram of a TFT array substrate used in a conventional flexible AMOLED is shown. As shown in fig. 5 and 6, the TFT array substrate defines a display region 100 'and a bending region 110'. In the display area 100 ', a common TFT device function layer is disposed, and in the bending area 110', metal layers are disposed to be used as a Data Line (Data Line) and a Vdd Line (Vdd Line), respectively, where the Data Line is generally implemented by using the first metal layer (SD1)104 'of the display area used as a source and a drain, and the Vdd Line is generally implemented by using the second metal layer (SD2) 106'.

According to the LTPS process flow commonly used in the art, referring to fig. 5-8, in the peripheral bending region 110 ' of the display panel, the filling layer 102 ' formed by the filled organic PI material covers a portion of the region at the hole edge of the filled upper first deep hole (DH1) and forms the symmetrically arranged side end, i.e. at the position 130 ' in fig. 5 and 7. In order to avoid the shortness caused by the first metal layer (SD1)104 ' remaining at the edge of the filler layer 102 ', the currently adopted method in the industry is to design the transition of the first metal layer 104 ' used as the data trace of the kink region 110 ' on the coverage area of the end of the oil layer 102 ', and only open an oil hole at the transition.

However, this structure has a problem that, as shown in fig. 7, at the position of the frame line region 130 ', since the oil layer 102 ' at both sides is provided with an opening, the middle of the frame line region is higher, which makes it difficult to release the bending stress, and on the other hand, when the subsequent first metal layer (SD1)104 ' is etched, the first metal layer 104 ' is at a risk of over-etching the line due to the higher position, which can be referred to as a circled portion 150 ' in fig. 8.

Therefore, there is a need to develop a new TFT array substrate to overcome the defects of the prior art.

Disclosure of Invention

One aspect of the present invention is to provide a TFT array substrate, wherein a bending region of the TFT array substrate is designed to have a new metal layer routing structure, so as to prevent a first metal layer from passing between two hole openings of an oil id filling layer during routing of the first metal layer in the bending region, thereby effectively reducing a risk of line breaking caused by over-etching.

The technical scheme adopted by the invention is as follows:

A TFT array substrate is defined with a display area and a bending area. The metal-based touch screen comprises a substrate layer and a functional layer arranged on the substrate layer, wherein the functional layer comprises an insulating layer and a metal layer. The functional layer of the bending region is provided with a filling layer through a deep hole, wherein the filling layer further extends out of the side end part of the edge of the deep hole from the side end part of the upper opening of the filling layer, the metal layer comprises a first metal layer, a second metal layer and a second gate layer in the bending region, and an insulating layer in the functional layer is arranged among the second gate layer, the first metal layer and the second metal layer. Wherein the first metal layer is disposed on the lateral end portions of the fill layer and meets the second gate layer through vias; wherein the second metal layer is disposed on the insulating layer at a position outside the first metal layer.

Further, in various embodiments, the metal layer further includes a first gate layer in the bending region, wherein a gate insulating layer is disposed between the first gate layer and a second gate layer, and the insulating layer disposed between the second gate layer and the first metal layer is an interlayer dielectric layer. Wherein in various embodiments, the interlayer dielectric layer may be a double-layer stacked structure, that is, including a first interlayer dielectric layer and a second interlayer dielectric layer, wherein the insulating layer between the second gate layer and the first metal layer is typically, but not limited to, the second interlayer dielectric layer.

Further, in various embodiments, the insulating layer disposed between the first metal layer and the second metal layer is a first flat layer, wherein a part of the interlayer dielectric layer is covered under a side end portion of the filling layer.

further, in various embodiments, the second metal layer is connected to the first gate layer by a via.

Further, in various embodiments, a relay metal layer is further disposed between the second metal layer and the first gate layer, the second metal layer is connected to the relay metal layer through a via, and the relay metal layer is connected to the first gate layer through a via. Wherein the transfer metal layer is preferably a first metal layer formed when the first metal layer is patterned.

Further, in various embodiments, the functional layer of the kink region further includes a buffer layer disposed on the substrate layer, wherein the filling layer penetrates the buffer layer downward into the substrate layer.

Further, in various embodiments, wherein the substrate layer comprises a PI layer and a barrier layer disposed thereon, wherein the bottom of the filler layer passes through the barrier layer to a surface of the PI layer.

Further, in various embodiments, the insulating layer between the first metal layer and the second metal layer in the bending region is a first flat layer, and the second metal layer is covered with a second flat layer.

Further, another aspect of the present invention provides a display panel including the TFT array substrate according to the present invention.

Further, in various embodiments, the display panel is a flexible AMOLED display panel.

Compared with the prior art, the invention has the beneficial effects that: the invention relates to a TFT array substrate, which adopts a novel bending area routing structure, and the routing position of an original first metal layer and the routing position of an original second metal layer in a bending area are changed into the routing position of the original second metal layer by replacing the routing positions of the original first metal layer and the original second metal layer in the bending area, so that the positions are replaced by a first flat layer, and the problem of easy wire breakage caused by the fact that the routing of the original first metal layer in the bending area passes through two hole openings of an OILD filling layer is solved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

fig. 1 is a cross-sectional structural view of a TFT array substrate according to an embodiment of the present invention;

Fig. 2 is a plan view of the TFT array substrate shown in fig. 1, in which only a plan view of a bending region thereof is shown;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;

FIG. 4 is a cross-sectional view taken along line B-B of FIG. 2;

Fig. 5 is a cross-sectional structural view of a TFT array substrate according to the related art, at the position of a first metal layer;

Fig. 6 is a schematic cross-sectional structure view of the TFT array substrate shown in fig. 5, at the position of the second metal layer thereof;

Fig. 7 is a plan view of the TFT array substrate shown in fig. 5, in which only the plan structure of the bending region thereof is shown; and

Fig. 8 is a sectional view taken along line a '-a' of fig. 7.

Detailed Description

The following describes a TFT array substrate and a display panel thereof in further detail with reference to the accompanying drawings and embodiments.

Referring to fig. 1, one embodiment of the invention provides a TFT array substrate, which defines a display area 100 and a bending area 110.

the TFT array substrate includes a substrate layer 101, where the substrate layer 101 may specifically be a double-layer-stack structure design using a double PI substrate structure, i.e., a PI layer combined with a Barrier layer (Barrier), but is not limited thereto. A Buffer layer (Buffer)1011 is disposed on the substrate layer 101.

In the display area 100, a TFT device function layer is disposed on the buffer layer 1011, and includes a metal layer and an insulating layer, where the metal layer specifically includes an Active layer (Active)103, a first gate layer (GE1)105, a second gate layer (GE2)107, and a first metal layer (SD1)104 serving as a source drain layer. The insulating layers are disposed between different metal layers, which specifically include a first gate insulating layer (GI1)1031, a second gate insulating layer (GI2)1032, a first interlayer dielectric layer (ILD1)1051, and a second interlayer dielectric layer (ILD2) 1071. Wherein the metal layers and the insulating layers can adopt a single-layer structure or a laminated structure as required. A passivation layer (PV) may be further disposed on the first metal layer 104 to protect the first metal layer 104 from external moisture, so that the service life of the first metal layer is reduced due to the moisture.

Further, a first flat layer (PLN1)1091 and a second flat layer (PLN1)1092 are disposed on the second interlayer dielectric layer 1071, and a second metal layer (SD2)106 and an anode metal layer (ANO)109 are disposed in the two flat layers. The second metal layer 106 and the anode metal layer 109 are connected by a via, and the second metal layer 106 is also connected to the first metal layer 104 by a via.

in the bending region, the structure is different from that of the display region because the bending function is required. The buffer layer 1011 disposed on the substrate layer 101 is disposed with a filling layer (oil) 102, which is filled with an organic material, specifically an organic PI material, so as to better realize the bending at the position.

Further, the filling layer 102 penetrates through the second interlayer dielectric layer (ILD2)1071, the first interlayer dielectric layer (ILD1)1051, the second gate insulating layer (GI2)1032 and the first gate insulating layer (GI1)1031 provided in the bending region 110 and downward penetrates through the buffer layer 1011 to the inside of the substrate layer 101, and specifically may penetrate through a barrier layer in the substrate layer 101 to reach the surface of the PI layer thereof, but is not limited thereto.

Further, although the filling layer 102 is formed by filling a Deep Hole (DH), it is not limited to an in-hole filling structure, and it has an upper opening 1022 formed on the surface of the deep hole, and then two symmetrically disposed side end portions 1021 covering the underlying interlayer functional layer are protruded outward at the side edges of the deep hole, wherein the side end portions 1021 are disposed on the second interlayer dielectric layer (ILD2)1071, and the side end portions 1021 and the upper opening 1022 can be filled by the first flat layer 1091.

Further, the bending region may also be disposed with a metal layer for use as a Data Line (Data Line) or a Vdd Line (Vdd Line), which includes a first gate layer, a second gate layer, a first metal layer and a second metal layer, and specific routing positions of the metal layers will be described below. Moreover, the position relationship of the first metal layer and the second metal layer in the bending region 110 is also an important aspect of the present invention. The following description will focus on the drawings.

in order to overcome the problem of easy breakage, the invention adopts a transposition design scheme, in which the routing position of the first metal layer is changed and arranged at the routing position of the original second metal layer, and the routing position of the original second metal layer is changed and arranged at the routing position of the original first metal layer.

specifically, referring to fig. 1 in combination with fig. 2 to 4, a first metal layer (SD1)1050 of the bending region is disposed on an end 1021 of the filling layer 102 of the bending region, and extends inward into the upper opening 1022 of the filling layer; and, it is electrically connected to the kink-region second gate layer 1070 through a via, a kink-region second metal layer 1060 is disposed outside the kink-region first metal layer 1040, and the kink-region second metal layer 1060 is electrically connected to the kink-region first gate layer 1050 downward through a transition first metal layer 1041. Furthermore, the metal layers disposed in the bending region 110 are symmetrically distributed along two sides of the filling layer 102.

Comparing the positions of the first metal layer (SD1) and the second metal layer (SD2) shown in fig. 1 of the present invention with the positions of the first metal layer and the second metal layer shown in fig. 5 and 6 of the prior art, the present invention converts the position relationship between the first metal layer 1040 and the second metal layer 1060 in the bending region, so that the routing position of the original first metal layer is converted to the routing position of the original second metal layer, and the routing position of the original second metal layer is converted to the routing position of the original first metal layer. Therefore, the first metal layer and the second metal layer are arranged at intervals from top to bottom between the layers, and after the first metal layer and the second metal layer are interchanged, the OILD hole does not exist on the wiring edge of the first metal layer, the problem that the position between the two holes is higher does not exist, and therefore the risk of over-etching and wire breaking is effectively reduced.

Further, another embodiment of the present invention provides a display panel using the TFT array substrate according to the present invention.

The technical scope of the present invention is not limited to the contents described in the above description, and those skilled in the art can make various changes and modifications to the above-described embodiments without departing from the technical spirit of the present invention, and these changes and modifications should fall within the scope of the present invention.