WO2022007132A1

WO2022007132A1 - Tft array substrate, display apparatus, and method for preparing tft array substrate

Info

Publication number: WO2022007132A1
Application number: PCT/CN2020/109926
Authority: WO
Inventors: 蔡振飞
Original assignee: 武汉华星光电半导体显示技术有限公司
Priority date: 2020-07-10
Filing date: 2020-08-19
Publication date: 2022-01-13
Also published as: CN111864107A

Abstract

Provided are a TFT array substrate, an AMOLED display apparatus, and a method for preparing a TFT array substrate. A light conversion layer is arranged on a TFT array substrate, light of three primary colors is emitted by means of combining a monochrome light-emitting layer with the light conversion layer, and incident ambient light is absorbed by means of the light conversion layer. By means of the AMOLED display apparatus of the present invention, the aim of preventing the reflection of ambient light without the need for a polarizer is achieved, the light emission efficiency of an OLED device and the brightness of the AMOLED display apparatus are improved, power consumption is reduced, and costs are also saved.

Description

TFT array substrate, display device and preparation method of TFT array substrate

technical field

The present application relates to the field of display technology, and in particular, to a TFT array substrate, an AMOLED display device using the TFT array substrate, and a preparation method of the TFT array substrate.

Background technique

Active-Matrix Organic Light Emitting Diode (AMOLED) display devices have the advantages of wide color gamut, fast color change reflection rate, and low energy consumption. When displaying a device, the display panel will reflect ambient light to human eyes, which affects the display effect and user experience.

In order to avoid the reflection of ambient light, the prior art usually adopts the practice of adding polarizers, as shown in FIG. 1 , the thin film transistor (Thin Film Transistor (TFT) substrate 10 includes a substrate 100, an emission anode 105, a signal line 106, and a light-emitting layer 107 that are sequentially arranged on the sink 100 along the light-emitting direction. A layer of linear polarizers 101 and four layers are arranged on the TFT substrate 10 1/4 circular polarizer 102, when ambient light 301 passes through linear polarizer 101, ambient light 301 is filtered into linear polarized light 302 in a single direction, and then passes through circular polarizer 103 of 1/4 wave plate, it becomes It is the circularly polarized light 303 with a phase deflection of 45°. The circularly polarized light irradiates the signal line of the substrate or the reflective anode 105 in the pixel opening area and is reflected back, and passes through the circular polarizer 103 of the 1/4 wave plate again. At this time, the phase of the light is transformed by 90 °, the linear polarizer 302 can no longer be passed through, so that the ambient light cannot reach the human eye, so that the ambient light can be prevented from being emitted to the human eye by the organic light emitting diode (Organic Light Emitting Diode, OLED) substrate.

However, the current polarizer is expensive, and its light transmittance is only 40%~50%. While filtering the ambient light, it will also affect the light emitted by the OLED device. As a result, the brightness of the AMOLED display device will be reduced, and the luminous efficiency of the OLED device will be reduced. When the impact is reached, the power consumption during use is increased.

technical problem

The existing OLED devices have low luminous efficiency and high power consumption.

technical solutions

The invention provides a TFT array substrate, an AMOLED display device, and a preparation method of the TFT array substrate. By arranging a light conversion layer on the TFT array substrate, the monochromatic light-emitting layer and the light conversion layer are combined to emit three primary colors of light, and the light is converted by light. The layer absorbs incident ambient light.

beneficial effect

The combination of the monochromatic light-emitting layer and the light conversion layer is adopted to reduce the reflection of the TFT substrate to ambient light, and the incident ambient light is absorbed by the light conversion layer, so as to achieve the purpose of preventing the reflection of ambient light without a polarizer, and improve the luminescence of the OLED device. Efficiency and brightness of AMOLED display devices, reducing AMOLED The power consumption of the display device, and the AMOLED device also saves costs by eliminating the polarizer.

Description of drawings

1 is a schematic cross-sectional view of a TFT array substrate in the prior art;

2 is a schematic cross-sectional view of a TFT array substrate provided by the present application;

FIG. 3 is a schematic flowchart of a method for preparing a TFT array substrate provided by the present application.

BEST MODE FOR CARRYING OUT THE INVENTION

In some embodiments, as shown in FIG. 2, the monochromatic light emitting layer 201 is a blue OLED, the first monochromatic light is blue light, the second monochromatic light is red light, the third monochromatic light is green light, and the third monochromatic light is green light. A light emitting area 210 emits blue light, the first light conversion area 213 is a green light conversion area, and the second light conversion area 214 is a red light conversion area. The monochromatic light emitting layer 201 cooperates with the light conversion layer 203 to emit three primary colors of red, green and blue. Light.

Due to the large loss of ambient light when passing through the blue OLED, using the blue OLED as the monochromatic light emitting layer 201 can further absorb the ambient light and avoid the reflection of the ambient light; it should be noted that the monochromatic light emitting layer 201 can also use the Green light OLED or red light OLED, when red light OLED is used as monochromatic light emitting layer 201, the corresponding light conversion layer 203 is green light conversion layer and blue light conversion layer, when green light OLED is used as monochromatic light emitting layer 201, The corresponding light conversion layers 203 are red light conversion layers and blue light conversion layers.

In order to further enhance the absorption of the ambient light 301 by the TFT substrate 20 and avoid the reflection of ambient light, referring to FIG. 2 , in some embodiments, a non-ferrous metal layer is provided on the surface of the signal line 202 to absorb the ambient light irradiated on the surface of the signal line 202 301, the non-ferrous metal layer may use chromium or a chromium-containing alloy.

When the light conversion sheet 203 is arranged in the TFT substrate 20 and the non-ferrous metal layer is arranged on the surface of the signal line 202, most of the ambient light 301 irradiated on the TFT substrate 20 can be absorbed, but some ambient light 301 is still irradiated to The signal line 202 and the reflective anode 205 in the pixel opening area are reflected; in order to further reduce the reflection of the ambient light 301, in some embodiments, as shown in FIG. 2, the TFT array substrate 20 further includes a light shielding layer 204, the signal line 202 and The light-shielding layer 204 is correspondingly arranged, and the signal line 202 and the light-shielding layer 204 are arranged in sequence along the light-emitting direction; the ambient light 301 is reflected after irradiating the signal line 202 and the reflective anode 205 in the pixel opening area, and the reflected ambient light is reflected by the light-shielding layer 204 The shading further reduces the reflection of the ambient light 301; in order to ensure a good shading effect, the shading layer 204 needs to have a certain thickness, and the thickness may be 100 nanometers to 150 nanometers.

In some embodiments, the material of the light-shielding layer 204 is black resin. It can be understood that the light-shielding layer 204 can also be made of other materials that can better absorb light, such as alloys containing chromium; of course, the light-shielding layer 204 is made of black resin. The manufacturing cost of the display device can be reduced.

In order to enable the light shielding layer 204 to better shield the ambient light reflected from the signal line 202 and the reflective anode 205 in the pixel opening area, in some embodiments, the width of the light shielding layer 204 is greater than the width of the signal line 202. The layer 204 covers the signal line 202, which can ensure that the light reflected from the signal line 202 and the reflective anode 205 in the pixel opening area can be completely blocked by the light shielding layer 204; it should be noted that the light shielding layer 204 can not be too wide, if it is too wide It will block the light emitted by the OLED and affect the brightness of the display device; on the premise of not affecting the light emission of the OLED, increasing the width of the light-shielding layer 204 so that it can completely cover the signal line 202 is to reduce the reflection of the TFT substrate 20 for ambient light. advantageous.

In order to make the surface of the TFT substrate 20 flat and prevent moisture and oxygen in the air from eroding into the interior of the TFT substrate 20 , in some embodiments, as shown in FIG. 2 , the TFT array substrate 20 further includes a protective resin layer 206 . To prevent the protective resin layer from affecting the brightness of the AMOLED display device, the light transmittance of the protective resin layer needs to be greater than 95%. It is understandable that the greater the light transmittance of the protective resin layer, the smaller the impact on the brightness of the AMOLED display device.

Due to the small light exit angle of the AMOLED display device, there will be glare problems when viewing the display device at certain angles in daily use. In order to prevent glare, in some embodiments, as shown in FIG. 2 , the TFT array substrate is further Two elliptical polarizers 208 are attached, and the elliptical polarizer 208 can increase AMOLED The exit angle of the light emitted by the display device plays the role of anti-glare.

The embodiment of the present application also provides a method for preparing a TFT array substrate, and the method for preparing the TFT array substrate includes the following steps:

S101 , fabricating a monochromatic light-emitting layer 201 for emitting a first monochromatic light, and fabricating at least one signal line 202 between different light-emitting regions of the monochromatic light-emitting layer 201 .

The monochromatic light-emitting layer 201 includes a first light-emitting region 210 , a second light-emitting region 211 and a third light-emitting region 212 .

In the embodiment of the present invention, after the backplane of the TFT array substrate is completed, the monochromatic light-emitting layer 201 is fabricated by evaporation method, and the evaporation method is cheaper than the traditional FFM (Fine Metal Mask, fine metal mask) method. , and the use of evaporation method helps to reduce the distance between pixels, thereby improving the pixels (Pixels Per Inch, PPI) of the AMOLED display device, so that the display effect of the AMOLED display device is better.

S102 , encapsulating the monochromatic light-emitting layer 201 to form an encapsulation layer 207 .

In the embodiment of the present invention, after the monochromatic light-emitting layer is formed by evaporation, plasma-enhanced chemical vapor deposition (Plasma Enhanced Chemical Vapor Deposition) is adopted. Chemical Vapor Deposition, PECVD) and ink jet printing (Ink Jet Printing, IJP) process to encapsulate the light-emitting layer to form the encapsulation layer 207; PECVD is to ionize the gas containing the atoms of the film by means of microwave or radio frequency, etc., to form a plasma locally , and the plasma chemical activity is very strong, it is easy to react, so the desired film can be easily deposited on the substrate, the use of PECVD process can reduce costs, improve productivity, and can improve the uniformity of the packaging layer; IJP process is through micron The high-grade printing nozzle sprays the material solution onto the substrate, and the IJP process can effectively save raw materials and reduce costs.

S103 , forming the light conversion layer 203 on the encapsulation layer 207 .

The light conversion layer 203 includes a first light conversion area 213 and a second light conversion area 214, the second light conversion area 214 corresponds to the third light emitting area 212, the first light conversion area 213 corresponds to the second light emitting area 211, and the second light conversion area 214 corresponds to the third light emitting area 212. The conversion area 214 is used to convert the received first monochromatic light into the second monochromatic light, and the first light conversion area 213 is used to convert the received first monochromatic light into the third monochromatic light, the first monochromatic light , the second monochromatic light and the third monochromatic light are different.

S104 , after the light conversion layer 203 is formed on the encapsulation layer 207 , a light shielding layer 204 is formed in the region of at least one signal line 202 .

In some embodiments of the present invention, the light shielding layer 204 is formed in the routing area of the signal line 202 by a photolithography process, which can effectively block and absorb the ambient light reflected from the signal line 202 and the reflective anode 205 in the pixel opening area, further reducing the For the reflection of ambient light 301, the material of the light-shielding layer 204 can be non-ferrous metal chromium or chromium-containing alloy. Non-ferrous metal chromium or chromium-containing alloy has a good absorption effect on light. Resins are more environmentally friendly than using chromium-containing metals, and at the same time cost less.

S105, coating a protective resin layer on the light conversion layer and the light shielding layer.

In some embodiments of the present invention, in order to prevent air and water vapor from entering the interior of the TFT substrate and causing erosion of its internal components, a protective resin layer 206 is coated on the light conversion layer 203 and the light shielding layer 204. While protecting the TFT substrate, it also makes the surface of the TFT substrate flat. In order not to affect the light emitted by the light-emitting layer 201 and not reduce the brightness of the AMOLED display device, the light transmittance of the material used in the protective resin layer 206 needs to be 95%. From the above, it can be understood that the higher the light transmittance of the material, the smaller the influence of the protective resin layer 206 on the brightness of the AMOLED display device.

S106, attaching two elliptically polarizers on the protective resin layer.

In some embodiments of the present invention, in order to increase the exit angle of the light emitted by the AMOLED display device and prevent glare to the human eye, two elliptically polarizers 208 are pasted on the protective resin layer 206 by a bonding method. On the protective resin layer 206, two elliptical polarizers 208 can increase the exit angle of the light emitted by the light emitting layer 201, thereby effectively preventing glare.

Embodiments of the present invention

First, an embodiment of the present application provides a TFT array substrate. As shown in FIG. 2 , the AMOLED display device includes a TFT array substrate 20 , and the TFT array substrate 20 includes a substrate 200 , a monochromatic light-emitting layer 201 , a signal line 202 and a light conversion layer 203, the signal line 202 is arranged between the monochromatic light emitting layers 201, the monochromatic light emitting layer 201 and the light conversion layer 203 are arranged in sequence along the light emitting direction, and the monochromatic light emitting layer 201 includes a first light emitting area 210, a second light emitting area 211 and a third light emitting area 201. In the light emitting area 212, the light conversion layer 203 includes a first light conversion area 213 and a second light conversion area 214, the second light conversion area 214 corresponds to the third light emitting area 212, and the first light conversion area 213 corresponds to the second light emitting area 211 , the second light conversion area 214 is used to convert the received first monochromatic light into the second monochromatic light, and the first light conversion area 213 is used to convert the received first monochromatic light into the third monochromatic light, so The first monochromatic light, the second monochromatic light and the third monochromatic light are different; the light emitted by the monochromatic light-emitting layer 201 will be converted into wavelengths after passing through the light conversion layer, and its brightness will not be lost basically, but Since the ambient light 301 is white light, when the ambient light 301 passes through the light conversion layer, the light conversion layer 203 will only reflect the light of the wavelength corresponding to its color, and the light of other wavelengths will be absorbed by the light conversion layer 203 , thereby reducing the ambient light 301 The effect of reflection, and the use of monochromatic devices for the light-emitting layer also reduces the manufacturing cost of the display device.

The embodiments of the present application also provide a method for preparing a TFT array substrate, and the method for preparing a TFT array substrate includes the following steps:

making a monochromatic light-emitting layer for emitting first monochromatic light, the monochromatic light-emitting layer comprising a first light-emitting region, a second light-emitting region and a third light-emitting region;

Making at least one signal line between different light-emitting regions of the single-color light-emitting layer;

Encapsulate the monochromatic light-emitting layer to form an encapsulation layer;

A light conversion layer is formed on the encapsulation layer, the light conversion layer includes a first light conversion area and a second light conversion area, the second light conversion area corresponds to the third light emitting area, the first light conversion area The conversion area corresponds to the second light-emitting area, the second light conversion area is used for converting the received first monochromatic light into the second monochromatic light, and the first light conversion area is used for converting the received first monochromatic light into the second monochromatic light. The monochromatic light is converted into a third monochromatic light, and the first monochromatic light, the second monochromatic light and the third monochromatic light are different.

As shown in FIG. 3 , FIG. 3 is a flowchart of an embodiment of a method for preparing a TFT array substrate in an embodiment of the present application, and the method includes:

S103 , forming the light conversion layer 203 on the encapsulation layer 207 .

Industrial Applicability

S103 , forming the light conversion layer 203 on the encapsulation layer 207 .

In the embodiment of the present invention, after the monochromatic light emitting layer 201 is encapsulated, the light conversion layer 203 is formed on the encapsulation layer 207 by printing, and the light conversion layer 203 is used to cooperate with the monochromatic light emitting layer 201 to form red, green and blue Three primary colors of light; in actual production, photolithography can also be used to form the light conversion layer 203, but the photolithography method is used to form the light conversion layer 203, which is difficult to manufacture and difficult to mass-produce. The conversion layer 203 has the advantages of being simple to manufacture and saving materials; the material of the light conversion layer 203 can be made of quantum dot material. The quantum dot material is an inorganic material with a wide absorption spectrum and a narrow emission spectrum, which is good for ambient white light. and can meet the requirements of AMOLED display devices for high color gamut.

S106, attaching two elliptically polarizers on the protective resin layer.

Claims

A TFT array substrate, wherein the TFT array substrate comprises a monochromatic light-emitting layer for emitting a first monochromatic light, at least one signal line and a light conversion layer;

The monochromatic light-emitting layer and the light-conversion layer are arranged in sequence along the light-emitting direction of the monochromatic light-emitting layer, the light-conversion layer includes a first light-conversion area and a second light-conversion area, and the monochromatic light-emitting layer includes a first light-emitting area , a second light emitting area and a third light emitting area, the second light conversion area corresponds to the third light emitting area, the first light conversion area corresponds to the second light emitting area, the second light conversion area used to convert the received first monochromatic light into second monochromatic light, the first light conversion area is used to convert the received first monochromatic light into a third monochromatic light, the first monochromatic light , the second monochromatic light is different from the third monochromatic light;

The at least one signal line is disposed between two different light-emitting regions in the single-color light-emitting layer.
The TFT array substrate according to claim 1, wherein the first monochromatic light is green light, the second monochromatic light is red light, and the third monochromatic light is blue light.
The TFT array substrate according to claim 1, wherein the first monochromatic light is red light, the second monochromatic light is green light, and the third monochromatic light is blue light.
The TFT array substrate according to claim 1, wherein the first monochromatic light is blue light, the second monochromatic light is red light, and the third monochromatic light is green light.
The AMOLED display device according to claim 4, wherein a non-ferrous metal layer is provided on the surface of the signal line.
The TFT array substrate according to claim 4, wherein the TFT array substrate further comprises a light shielding layer, the signal lines and the light shielding layer are arranged correspondingly, and the signal lines and the light shielding layer are arranged along the single The light emitting directions of the colored light emitting layers are set in sequence.
The TFT array substrate according to claim 6, wherein the material of the light shielding layer is black resin.
The TFT array substrate according to claim 6, wherein the material of the light shielding layer is a chromium-containing alloy.
The TFT array substrate according to claim 6, wherein the thickness of the light shielding layer is 100-150 nanometers.
The TFT array substrate according to claim 6, wherein the width of the light shielding layer is greater than the width of the signal line.
The TFT array substrate according to claim 1, wherein the TFT array substrate further comprises a protective resin layer, the protective resin layer covers the light conversion layer, and the light transmittance of the protective resin layer is greater than 95%.
The TFT array substrate according to claim 1, wherein the TFT array substrate further comprises two elliptical polarizers, the light conversion layer and the elliptical polarizer are arranged in sequence along the light emitting direction of the monochromatic light emitting layer.
An AMOLED display device, wherein the AMOLED display device includes a TFT array substrate, and the TFT array substrate includes a monochromatic light-emitting layer for emitting a first monochromatic light, at least one signal line, and a light conversion layer;

The monochromatic light-emitting layer and the light-conversion layer are arranged in sequence along the light-emitting direction of the monochromatic light-emitting layer, the light-conversion layer includes a first light-conversion area and a second light-conversion area, and the monochromatic light-emitting layer includes a first light-emitting area , a second light emitting area and a third light emitting area, the second light conversion area corresponds to the third light emitting area, the first light conversion area corresponds to the second light emitting area, the second light conversion area used to convert the received first monochromatic light into second monochromatic light, the first light conversion area is used to convert the received first monochromatic light into a third monochromatic light, the first monochromatic light , the second monochromatic light is different from the third monochromatic light;

The at least one signal line is disposed between two different light-emitting regions in the single-color light-emitting layer.
The AMOLED display device according to claim 13, wherein the first monochromatic light is green light, the second monochromatic light is red light, and the third monochromatic light is blue light.
The AMOLED display device according to claim 13, wherein the first monochromatic light is red light, the second monochromatic light is green light, and the third monochromatic light is blue light.
The AMOLED display device according to claim 13, wherein the first monochromatic light is blue light, the second monochromatic light is red light, and the third monochromatic light is green light.
The AMOLED display device according to claim 16, wherein a non-ferrous metal layer is provided on the surface of the signal line.
The AMOLED display device according to claim 16, wherein the TFT array substrate further comprises a light shielding layer, the signal lines and the light shielding layer are arranged correspondingly, and the signal lines and the light shielding layer are arranged along the single The light emitting directions of the colored light emitting layers are set in sequence.
A method for preparing a TFT array substrate, comprising the following steps:

making a monochromatic light-emitting layer for emitting first monochromatic light, the monochromatic light-emitting layer comprising a first light-emitting region, a second light-emitting region and a third light-emitting region;

Making at least one signal line between different light-emitting regions of the single-color light-emitting layer;

Encapsulate the monochromatic light-emitting layer to form an encapsulation layer;

A light conversion layer is formed on the encapsulation layer, the light conversion layer includes a first light conversion area and a second light conversion area, the second light conversion area corresponds to the third light emitting area, the first light conversion area The conversion area corresponds to the second light-emitting area, the second light conversion area is used for converting the received first monochromatic light into the second monochromatic light, and the first light conversion area is used for converting the received first monochromatic light into the second monochromatic light. The monochromatic light is converted into a third monochromatic light, and the first monochromatic light, the second monochromatic light and the third monochromatic light are different.
The method of claim 19, wherein after forming a light conversion layer on the encapsulation layer, the method comprises:

forming a light shielding layer on the at least one signal line area;

Coating a protective resin layer on the light conversion layer and the light shielding layer;

Two elliptically polarizing plates are attached on the protective resin layer.