阅读说明：本技术 一种无电学接触的全彩化μLED微显示器件及其制造方法 (Full-color mu LED micro-display device without electrical contact and manufacturing method thereof ) 是由 张永爱 陈诗瑶 郭太良 周雄图 吴朝兴 林志贤 孙磊 严群 于 2019-10-16 设计创作，主要内容包括：本发明涉及一种无电学接触的全彩化μLED微显示器件及其制造方法。包括设置于透明下基板表面的反射层、下驱动电极,设置于透明上基板表面的扩散层、上驱动电极,设置于上、下驱动电极之间的蓝光μLED晶粒和波长下转换发光层,以及控制模块和彩色滤光膜；上、下驱动电极和所述蓝光μLED晶粒无电学接触,控制模块与上、下驱动电极电学连接,所述控制模块提供交变驱动信号控制μLED晶粒激发出第一光源,经波长下转换发光层转化为第二光源,第一、第二光源经反射层和扩散层后,经彩色滤光膜实现全彩化μLED微显示。本发明可有效地避免全彩μLED器件中三基色μLED芯片复杂制作工艺,及发光芯片与驱动芯片复杂Bonding和巨量转移工艺,缩短μLED显示制作周期,降低制作成本。(The invention relates to a full-color mu LED micro-display device without electrical contact and a manufacturing method thereof. The device comprises a reflecting layer and a lower driving electrode which are arranged on the surface of a transparent lower substrate, a diffusion layer and an upper driving electrode which are arranged on the surface of a transparent upper substrate, a blue light mu LED crystal grain and a wavelength down-conversion luminescence layer which are arranged between the upper driving electrode and the lower driving electrode, a control module and a color filter film; the upper and lower driving electrodes are not in electrical contact with the blue mu LED crystal grains, the control module is electrically connected with the upper and lower driving electrodes, the control module provides an alternating driving signal to control the mu LED crystal grains to excite a first light source, the mu LED crystal grains are converted into a second light source through the wavelength down-conversion light-emitting layer, and the first and second light sources realize full-color mu LED micro-display through the color filter film after passing through the reflecting layer and the diffusion layer. The invention can effectively avoid the complex manufacturing process of the tricolor mu LED chip in the full-color mu LED device, the complex Bonding and mass transfer process of the light-emitting chip and the driving chip, shorten the mu LED display manufacturing period and reduce the manufacturing cost.)

1. A full-color μ LED micro-display device without electrical contact, comprising: a transparent lower substrate, a transparent upper substrate, a blue light mu LED crystal grain, a wavelength down-conversion luminescent layer, a control module, a frame body connecting the transparent upper substrate and the transparent lower substrate, an exhaust port arranged on the transparent upper substrate, a color filter film arranged on the transparent upper substrate, a reflecting layer arranged on the surface of the transparent lower substrate, a diffusion layer arranged on the surface of the transparent upper substrate, a lower driving electrode arranged above the transparent upper substrate, an upper driving electrode arranged below the transparent upper substrate,

the upper driving electrode and the lower driving electrode are respectively arranged at two sides of the blue light mu LED crystal grain, and the wavelength down-conversion light-emitting layer is arranged between the upper driving electrode, the lower driving electrode and the blue light mu LED crystal grain; the upper driving electrode, the lower driving electrode and the blue light mu LED crystal grain are not in direct electrical contact to form an independent space; the control module is respectively electrically connected with the upper driving electrode and the lower driving electrode, the control module provides alternating driving signals for the upper driving electrode and the lower driving electrode, a driving electric field is formed between the upper driving electrode and the lower driving electrode, the driving electric field controls the electron and the hole of the mu LED crystal grain to be combined and emit a first light source, the first light source is converted into a second light source through the wavelength down-conversion light-emitting layer, and the first light source and the second light source are mixed into a uniform third light source through the reflecting layer and the diffusion layer; the third light source realizes full-color mu LED micro display through the color filter film.

2. The full-color mu LED micro-display device without electrical contact as claimed in claim 1, wherein the color filter is disposed on the upper surface of the transparent upper substrate and corresponding to the upper driving electrode; the color filter film sequentially forms an R unit for red light display, a G unit for green light display and a B unit for blue light display along the direction of the upper driving electrode; the R unit, the G unit and the B unit are arranged at equal intervals and are directly filled with black barriers adjacently.

3. The full-color mu LED micro-display device without electrical contact of claim 1, wherein the blue mu LED die is formed by connecting a plurality of blue mu LED chips in series along a vertical direction, or by connecting a plurality of blue mu LED chips in parallel along a horizontal direction, or by randomly stacking a plurality of blue mu LED chips.

4. The device of claim 3, wherein the blue μ LED chip comprises p-type semiconductor material, light emitting structure and n-type semiconductor material stacked in a vertical direction to form a semiconductor junction.

5. The device of claim 4, wherein the semiconductor junction comprises a single semiconductor junction, a combination of one or more of multiple semiconductor junctions; the thickness of the P-type semiconductor material is 1nm-2.0 mu m, the thickness of the light-emitting structure is 1nm-1.0 mu m, and the thickness of the N-type semiconductor material is 1nm-2.5 mu m.

6. The full-color micro-display device with no electrical contact of the mu LED of claim 1, wherein the upper driving electrode is composed of a plurality of line electrodes parallel to each other and arranged on the surface of the upper transparent substrate along the horizontal direction of the mu LED die; the lower driving electrode is composed of a plurality of mutually parallel line electrodes, is arranged on the surface of the lower transparent substrate along the vertical direction of the mu LED crystal grains, is mutually vertical to the upper electrode and the lower electrode, and can form an independent space by the interval between the upper electrode and the lower electrode.

7. The full-color mu LED micro-display device without electrical contact of claim 1, wherein the wavelength down-conversion luminescent layer can be disposed on the surface of the upper driving electrode and the lower driving electrode, or can be disposed on the outer surface of the mu LED die, or can be mixed with and coated on the mu LED die, and is disposed in the independent space formed by the upper driving electrode and the lower driving electrode; the wavelength down-conversion luminescent layer is a yellow quantum dot material, or can be a yellow fluorescent powder material, or can be a mixed material of the yellow quantum dot and the yellow fluorescent powder; the wavelength down-conversion light-emitting layer excites a second light source with longer wavelength under the irradiation of the first light source light emitted by the blue light mu LED crystal grain, and the second light source is yellow light.

8. A full-colour μ LED micro-display device without electrical contact as claimed in claim 1, wherein the control module is capable of providing an alternating voltage of amplitude and polarity varying with time; the waveform of the alternating voltage is one or more of a sine wave, a triangular wave, a square wave and a pulse; the frequency of the alternating voltage is 1Hz-1000 MHz.

9. A method of fabricating a full colour micro-LED device based on an electrical contact according to any of claims 1-8, characterized by the following steps:

step S1, providing a transparent upper substrate with a vent, and depositing a diffusion layer and an upper driving electrode on one surface of the transparent upper substrate in sequence by using a physical vapor deposition or chemical vapor deposition or printing or ink-jet printing method; the diffusion layer mixes the first light source and the second light source to form a third light source which emits light uniformly; the upper driving electrode is a transparent electrode, and the material of the transparent electrode comprises graphene, indium tin oxide, carbon nano tubes, silver nano wires, copper nano wires and a combination thereof;

step S2, preparing a color filter film on the surface of the transparent upper substrate by using a photoetching or silk-screen printing method, wherein R units, G units and B units of the color filter film correspond to the upper driving electrodes one by one; the R unit, the G unit and the B unit are arranged at equal intervals, and black barriers are directly filled adjacently;

step S3, providing a transparent lower substrate, depositing a reflective layer and a lower driving electrode on the surface of the transparent lower substrate by physical vapor deposition or chemical vapor deposition or printing or ink-jet printing; the reflecting layer reflects the first light source, the second light source and the third light source mixed by the first light source and the second light source back, so that the efficiency of the device is improved; the material of the lower driving electrode comprises gold, silver, aluminum, copper and alloy or laminated structure thereof;

step S4, coating the frame sealing body on the periphery of the transparent lower substrate by using a screen printing or ink-jet printing or blade coating method;

step S5, providing a wavelength down-conversion luminescent layer: coating a layer of wavelength down-conversion luminescent layer on the surfaces of the upper driving electrode and the lower driving electrode by using a screen printing or ink-jet printing or spraying or spin coating method;

step S6, providing a blue μ LED die: coating a layer of blue light mu LED chip on the surface of the conversion luminescent layer under the wavelength by using an ink-jet printing or blade coating or spraying method;

step S7, aligning the upper and lower transparent substrates for packaging, degassing through the exhaust port, and sealing;

step S8, providing a control module; the control module is respectively electrically connected with the upper driving electrode and the lower driving electrode, the control module provides alternating driving signals for the upper driving electrode and the lower driving electrode, a driving electric field is formed between the upper driving electrode and the lower driving electrode, the driving electric field controls the electron and hole combination of the mu LED crystal grains and emits a first light source, the first light source is converted into a second light source through the wavelength down-conversion light emitting layer, the second light source is mixed into a uniform third light source through the reflecting layer and the diffusion layer, and the uniform third light source is converted into red light, green light and blue light through the color filter film to realize full-color mu LED micro-display.

10. A method of fabricating a full colour micro-LED device based on an electrical contact according to any of claims 1-8, characterized by the following steps:

step S1, providing a transparent upper substrate with a vent, and depositing a diffusion layer and an upper driving electrode on one surface of the transparent upper substrate in sequence by using a physical vapor deposition or chemical vapor deposition or printing or ink-jet printing method; the diffusion layer mixes the first light source and the second light source to form a third light source which emits light uniformly; the upper driving electrode is a transparent electrode, and the material of the transparent electrode comprises graphene, indium tin oxide, carbon nano tubes, silver nano wires, copper nano wires and a combination thereof;

step S2, preparing a color filter film on the surface of the transparent upper substrate by using a photoetching or silk-screen printing method, wherein R units, G units and B units of the color filter film correspond to the upper driving electrodes one by one; the R unit, the G unit and the B unit are arranged at equal intervals, and black barriers are directly filled adjacently;

step S3, coating the frame sealing body on the periphery of the transparent lower substrate by using a screen printing or ink-jet printing or blade coating method;

step S4, providing a transparent lower substrate, depositing a reflective layer and a lower driving electrode on the surface of the transparent lower substrate by physical vapor deposition or chemical vapor deposition or printing or ink-jet printing; the reflecting layer reflects the first light source, the second light source and the third light source mixed by the first light source and the second light source back, so that the efficiency of the device is improved; the material of the lower driving electrode comprises gold, silver, aluminum, copper and alloy or laminated structure thereof;

step S5, providing a blue mu LED die;

step S6, providing a wavelength down-conversion luminescent layer: uniformly mixing the wavelength down-conversion luminescence layer and the blue light mu LED chip, mixing and coating the mu LED crystal grains and the wavelength down-conversion luminescence layer together, and arranging the mixture on the surface of the lower driving electrode by using a screen printing or ink-jet printing or spraying or spin coating method;

step S7, aligning the upper and lower transparent substrates for packaging, degassing through the exhaust port, and sealing;

step S8, providing a control module; the control module is respectively electrically connected with the upper driving electrode and the lower driving electrode, the control module provides alternating driving signals for the upper driving electrode and the lower driving electrode, a driving electric field is formed between the upper driving electrode and the lower driving electrode, the driving electric field controls the electron and hole combination of the mu LED crystal grains and emits a first light source, the first light source is converted into a second light source through the wavelength down-conversion light emitting layer, and the second light source is converted into red light, green light and blue light through the reflecting layer and the diffusion layer and then is converted into the red light, the green light and the blue light through the color filter film to realize full-color mu LED micro-display.

Technical Field

The invention relates to the field of integrated semiconductor display, in particular to a full-color mu LED micro-display device without electrical contact and a manufacturing method thereof.

Background

In the field of flat panel display technology, micron-scale LED display (abbreviated as μ LED display) refers to the formation of a micron-scale pitch LED array after traditional LEDs are miniaturized to achieve ultra-high density pixel resolution. Compared with OLED and LCD, the mu LED display has the advantages of low power consumption, high brightness, ultrahigh definition, high color saturation, faster response speed, longer service life, higher working efficiency and the like; in addition, the mu LED display is the only display device which can integrate driving, light emitting and signal transmission and has high light emitting efficiency and low power consumption, and realizes a super large scale integrated light emitting unit. Due to the fact that two technical characteristics of the LCD and the LED are integrated, the performance of the product is far higher than that of the existing TFT-LCD and OLED, and the product can be widely applied to the fields of flexible display, vehicle-mounted display, transparent display, large-area display, wearable display, AR/VR and the like. However, due to the problems of size and quantity, the micron-sized LED integration has a series of technical difficulties in bonding, transferring, driving, colorizing and the like.

At present, full-color mu LED display generally carries out epitaxial growth on a GaN or GaAs substrate through Metal Organic Chemical Vapor Deposition (MOCVD), red, green and blue mu LED chips with three primary colors are prepared through a plurality of processes, and are bound on a circuit substrate through the mu LED chips with the three primary colors and a driving chip by utilizing a chip transfer and bonding process to form full-color mu LED display pixels, the technology needs to realize accurate electrical contact between a driving electrode and a driving module in the mu LED chips through accurate alignment and bonding, and needs to pick up, place and assemble a huge amount of mu LED crystal grains; in the aspect of colorization technology, the method can also be realized by a color conversion method, an optical prism synthesis method, a method for emitting light with different wavelengths by controlling the structure and the size of the LED, and the like. The color conversion of blue light LED + red green quantum dots is the mainstream technical route for realizing full-color mu LED display at present, in the prior art, the realization of Micro-LED full-color display by using the quantum dot technology is a common process optimization means, and the prior art and the preparation scheme are more. Chinese patents CN106356386A, CN108257949A, and CN109256455A fill red quantum dots and green quantum dots units in a blue μ LED chip to realize full-color display, but the blue μ LED chip needs to make a cathode and an anode, the quantum dots need to be patterned, and the μ LED chip is transferred by a large amount and then bonded with a driving electrode chip, so that the blue μ LED chip can be driven to emit light after the electrode contacts with the driving electrode chip, thereby realizing full-color display, resulting in a longer manufacturing period of the μ LED device and high manufacturing cost.

In summary, the invention provides a full-color mu LED micro-display without electrical contact, wherein an upper driving electrode and a lower driving electrode in the device are not in electrical contact with a p-type semiconductor layer and an n-type semiconductor layer in a mu LED crystal grain, a control module is respectively electrically connected with the upper driving electrode and the lower driving electrode to provide alternating driving signals for the upper driving electrode and the lower driving electrode, a driving electric field is formed between the upper driving electrode and the lower driving electrode, the alternating driving electric field controls the electron and hole of the mu LED crystal grain to be combined and emit a first light source, the first light source excites a wavelength down-conversion light-emitting layer second light source, the first light source and the second light source are converted into a uniform third light source after passing through a reflecting layer and a diffusion layer, and the third light source is converted into red light, green light and blue light through a color filter film to realize the full-color mu LED micro-display. The invention can avoid the complex manufacturing process of the tricolor chip in the mu LED light-emitting device, the complex bonding (bonding) of the light-emitting chip and the driving chip and the huge transfer process of the mu LED chip, effectively reduce the manufacturing period and the manufacturing cost of the mu LED device, and is expected to greatly improve the market competitiveness of full-color mu LED display.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a full-color mu LED display device without electrical contact and huge transfer, wherein an upper driving electrode, a lower driving electrode and a blue light mu LED crystal grain of the device are not directly electrically contacted to form an independent space; the control module is respectively electrically connected with the upper driving electrode and the lower driving electrode, provides alternating driving signals for the upper driving electrode and the lower driving electrode, forms a driving electric field between the upper driving electrode and the lower driving electrode, and under the control of the driving electric field, electrons and holes of the mu LED crystal grains are combined and emit a first light source, the first light source is converted into a second light source through a wavelength down-conversion light-emitting layer, and the first light source and the second light source are mixed into a uniform third light source through a reflecting layer and a diffusion layer; the third light source realizes full-color mu LED micro display through the color filter film. The full-color mu LED display device without the electrical contact and the huge transfer can effectively avoid the complex manufacturing process of a red/green/blue tricolor mu LED chip, simultaneously avoid the complex bonding process and the huge transfer process of a mu LED light-emitting chip and a driving chip, effectively shorten the manufacturing period of the mu LED, reduce the manufacturing cost of mu LED display and hopefully greatly improve the market competitiveness of the full-color mu LED display.

In order to achieve the purpose, the technical scheme of the invention is as follows: a full-color μ LED micro-display device without electrical contact, comprising: a transparent lower substrate, a transparent upper substrate, a blue light mu LED crystal grain, a wavelength down-conversion luminescent layer, a control module, a frame body connecting the transparent upper substrate and the transparent lower substrate, an exhaust port arranged on the transparent upper substrate, a color filter film arranged on the transparent upper substrate, a reflecting layer arranged on the surface of the transparent lower substrate, a diffusion layer arranged on the surface of the transparent upper substrate, a lower driving electrode arranged above the transparent upper substrate, an upper driving electrode arranged below the transparent upper substrate,

the upper driving electrode and the lower driving electrode are respectively arranged at two sides of the blue light mu LED crystal grain, and the wavelength down-conversion light-emitting layer is arranged between the upper driving electrode, the lower driving electrode and the blue light mu LED crystal grain; the upper driving electrode, the lower driving electrode and the blue light mu LED crystal grain are not in direct electrical contact to form an independent space; the control module is respectively electrically connected with the upper driving electrode and the lower driving electrode, the control module provides alternating driving signals for the upper driving electrode and the lower driving electrode, a driving electric field is formed between the upper driving electrode and the lower driving electrode, the driving electric field controls the electron and the hole of the mu LED crystal grain to be combined and emit a first light source, the first light source is converted into a second light source through the wavelength down-conversion light-emitting layer, and the first light source and the second light source are mixed into a uniform third light source through the reflecting layer and the diffusion layer; the third light source realizes full-color mu LED micro display through the color filter film.

In an embodiment of the invention, the color filter film is disposed on the upper surface of the transparent upper substrate and corresponds to the upper driving electrode; the color filter film sequentially forms an R unit for red light display, a G unit for green light display and a B unit for blue light display along the direction of the upper driving electrode; the R unit, the G unit and the B unit are arranged at equal intervals and are directly filled with black barriers adjacently.

In an embodiment of the present invention, the blue μ LED die is formed by connecting a plurality of blue μ LED chips in series in a vertical direction, or by connecting a plurality of blue μ LED chips in parallel in a horizontal direction, or by stacking a plurality of blue μ LED chips arbitrarily.

In an embodiment of the invention, the blue mu LED chip includes a p-type semiconductor material, a light emitting structure and an n-type semiconductor material, and the p-type semiconductor material, the light emitting structure and the n-type semiconductor material are stacked in a vertical direction to form a semiconductor junction.

In one embodiment of the present invention, the semiconductor junction comprises one or more of a single semiconductor junction, a semiconductor junction, and a multiple semiconductor junction; the thickness of the P-type semiconductor material is 1nm-2.0 mu m, the thickness of the light-emitting structure is 1nm-1.0 mu m, and the thickness of the N-type semiconductor material is 1nm-2.5 mu m.

In an embodiment of the present invention, the upper driving electrode is composed of a plurality of line electrodes parallel to each other, and is disposed on the surface of the upper transparent substrate along a horizontal direction of the μ LED die; the lower driving electrode is composed of a plurality of mutually parallel line electrodes, is arranged on the surface of the lower transparent substrate along the vertical direction of the mu LED crystal grains, is mutually vertical to the upper electrode and the lower electrode, and can form an independent space by the interval between the upper electrode and the lower electrode.

In an embodiment of the present invention, the wavelength down-conversion luminescent layer may be disposed on the surfaces of the upper driving electrode and the lower driving electrode, or may be disposed on the outer surface of the μ LED die, or may be mixed and coated with the μ LED die, and disposed in an independent space formed by the upper driving electrode and the lower driving electrode; the wavelength down-conversion luminescent layer is a yellow quantum dot material, or can be a yellow fluorescent powder material, or can be a mixed material of the yellow quantum dot and the yellow fluorescent powder; the wavelength down-conversion light-emitting layer excites a second light source with longer wavelength under the irradiation of the first light source light emitted by the blue light mu LED crystal grain, and the second light source is yellow light.

In one embodiment of the invention, the control module may provide an alternating voltage of varying amplitude and polarity over time; the waveform of the alternating voltage is one or more of a sine wave, a triangular wave, a square wave and a pulse; the frequency of the alternating voltage is 1Hz-1000 MHz.

The invention also provides a method for manufacturing the full-color mu LED micro-display device based on the electrical contact, which is realized by the following steps:

step S1, providing a transparent upper substrate with a vent, and depositing a diffusion layer and an upper driving electrode on one surface of the transparent upper substrate in sequence by using a physical vapor deposition or chemical vapor deposition or printing or ink-jet printing method; the diffusion layer mixes the first light source and the second light source to form a third light source which emits light uniformly; the upper driving electrode is a transparent electrode, and the material of the transparent electrode comprises graphene, indium tin oxide, carbon nano tubes, silver nano wires, copper nano wires and a combination thereof;

step S2, preparing a color filter film on the surface of the transparent upper substrate by using a photoetching or silk-screen printing method, wherein R units, G units and B units of the color filter film correspond to the upper driving electrodes one by one; the R unit, the G unit and the B unit are arranged at equal intervals, and black barriers are directly filled adjacently;

step S3, providing a transparent lower substrate, depositing a reflective layer and a lower driving electrode on the surface of the transparent lower substrate by physical vapor deposition or chemical vapor deposition or printing or ink-jet printing; the reflecting layer reflects the first light source, the second light source and the third light source mixed by the first light source and the second light source back, so that the efficiency of the device is improved; the material of the lower driving electrode comprises gold, silver, aluminum, copper and alloy or laminated structure thereof;

step S4, coating the frame sealing body on the periphery of the transparent lower substrate by using a screen printing or ink-jet printing or blade coating method;

step S5, providing a wavelength down-conversion luminescent layer: coating a layer of wavelength down-conversion luminescent layer on the surfaces of the upper driving electrode and the lower driving electrode by using a screen printing or ink-jet printing or spraying or spin coating method;

step S6, providing a blue μ LED die: coating a layer of blue light mu LED chip on the surface of the conversion luminescent layer under the wavelength by using an ink-jet printing or blade coating or spraying method;

step S7, aligning the upper and lower transparent substrates for packaging, degassing through the exhaust port, and sealing;

step S8, providing a control module; the control module is respectively electrically connected with the upper driving electrode and the lower driving electrode, the control module provides alternating driving signals for the upper driving electrode and the lower driving electrode, a driving electric field is formed between the upper driving electrode and the lower driving electrode, the driving electric field controls the electron and hole combination of the mu LED crystal grains and emits a first light source, the first light source is converted into a second light source through the wavelength down-conversion light emitting layer, the second light source is mixed into a uniform third light source through the reflecting layer and the diffusion layer, and the uniform third light source is converted into red light, green light and blue light through the color filter film to realize full-color mu LED micro-display.

The invention also provides a method for manufacturing the full-color mu LED micro-display device based on the electrical contact, which is realized by the following steps:

step S1, providing a transparent upper substrate with a vent, and depositing a diffusion layer and an upper driving electrode on one surface of the transparent upper substrate in sequence by using a physical vapor deposition or chemical vapor deposition or printing or ink-jet printing method; the diffusion layer mixes the first light source and the second light source to form a third light source which emits light uniformly; the upper driving electrode is a transparent electrode, and the material of the transparent electrode comprises graphene, indium tin oxide, carbon nano tubes, silver nano wires, copper nano wires and a combination thereof;

step S2, preparing a color filter film on the surface of the transparent upper substrate by using a photoetching or silk-screen printing method, wherein R units, G units and B units of the color filter film correspond to the upper driving electrodes one by one; the R unit, the G unit and the B unit are arranged at equal intervals, and black barriers are directly filled adjacently;

step S3, coating the frame sealing body on the periphery of the transparent lower substrate by using a screen printing or ink-jet printing or blade coating method;

step S4, providing a transparent lower substrate, depositing a reflective layer and a lower driving electrode on the surface of the transparent lower substrate by physical vapor deposition or chemical vapor deposition or printing or ink-jet printing; the reflecting layer reflects the first light source, the second light source and the third light source mixed by the first light source and the second light source back, so that the efficiency of the device is improved; the material of the lower driving electrode comprises gold, silver, aluminum, copper and alloy or laminated structure thereof;

step S5, providing a blue mu LED die;

step S6, providing a wavelength down-conversion luminescent layer: uniformly mixing the wavelength down-conversion luminescence layer and the blue light mu LED chip, mixing and coating the mu LED crystal grains and the wavelength down-conversion luminescence layer together, and arranging the mixture on the surface of the lower driving electrode by using a screen printing or ink-jet printing or spraying or spin coating method;

step S7, aligning the upper and lower transparent substrates for packaging, degassing through the exhaust port, and sealing;

step S8, providing a control module; the control module is respectively electrically connected with the upper driving electrode and the lower driving electrode, the control module provides alternating driving signals for the upper driving electrode and the lower driving electrode, a driving electric field is formed between the upper driving electrode and the lower driving electrode, the driving electric field controls the electron and hole combination of the mu LED crystal grains and emits a first light source, the first light source is converted into a second light source through the wavelength down-conversion light emitting layer, and the second light source is converted into red light, green light and blue light through the reflecting layer and the diffusion layer and then is converted into the red light, the green light and the blue light through the color filter film to realize full-color mu LED micro-display.

Compared with the prior art, the invention has the following beneficial effects:

the upper and lower driving electrodes in the full-color mu LED micro-display device are not in electrical contact with the p-type semiconductor layer and the n-type semiconductor layer in the mu LED crystal grain, so that the complex manufacturing process of a mu LED chip and the complex bonding (bonding) and transferring process of the mu LED light-emitting chip and the driving chip can be effectively avoided, the manufacturing period of the mu LED is shortened, and the manufacturing cost of mu LED display is reduced;

the control module provided by the invention is respectively electrically connected with the upper driving electrode and the lower driving electrode, provides alternating driving signals for the upper driving electrode and the lower driving electrode, and forms a driving electric field between the upper driving electrode and the lower driving electrode;

and thirdly, the alternating driving electric field controls the electron and the hole of the mu LED crystal grain to be combined and emit a first light source, the first light source excites the wavelength to convert a second light source of a light emitting layer, the first light source and the second light source are converted into a uniform third light source through the reflecting layer and the diffusion layer, and the third light source is converted into red light, green light and blue light through the color filter film to realize full-color mu LED micro display, so that the manufacturing process and the manufacturing cost of full-color mu LED micro display without optical contact are effectively improved, and the method has important significance for full-color mu LED display development and application.

Drawings

Fig. 1 is a schematic structural view of a full-color μ LED micro-display without electrical contact according to a first embodiment of the present invention and fig. 1.

Fig. 2 is a schematic structural diagram of a first embodiment of the invention, in which μ LED chips are arbitrarily placed.

FIG. 3 is a flow chart of a method for manufacturing a full-color μ LED micro-display without electrical contact according to a first embodiment of the present invention.

Fig. 4 is a schematic diagram of a full-color μ LED micro-display without electrical contact according to a first embodiment of the present invention.

Fig. 5 is a schematic structural diagram of a full-color μ LED micro-display without electrical contact according to a second embodiment of the present invention.

Fig. 6 is a schematic structural diagram of a μ LED chip according to a second embodiment of the present invention.

FIG. 7 is a flow chart of a second embodiment of the present invention for manufacturing a full-color μ LED micro-display without electrical contact.

FIG. 8 is a schematic diagram of a full-color μ LED micro-display without electrical contact according to a second embodiment of the present invention.

In the figure: 100 is a transparent lower substrate, 200 is a transparent upper substrate, 110 is a reflective layer, 210 is a diffusion layer, 120 is a lower driving electrode, 220 is an upper driving electrode, 300 is a wavelength down-conversion light emitting layer, 400 is a mu LED chip, 401 is an n-type semiconductor material, 402 is a p-type semiconductor material, 403 is a light emitting structure, 500 is a frame body, 600 is an exhaust port, 700 is a color filter film, 701 is an R unit, 702 is a G unit, 703 is a B unit, 704 is a black barrier layer, 800 is a control module, 111 is a first light source, 112 is a second light source, 113 is a third light source, 11 is red light, 12 is green light, and 13 is blue light.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to specific embodiments and accompanying drawings. In the figures, the thicknesses of layers and regions are exaggerated for clarity, but as a schematic illustration should not be considered to reflect strictly the geometric scaling. Here, the reference drawings are intended as an idealized embodiment of the present invention, and embodiments of the present invention should not be considered limited to the specific shapes of regions shown in the drawings, but include resulting shapes such as manufacturing-induced deviations. In the present embodiment, the rectangular or round shape is used for illustration, but this should not be construed as limiting the scope of the present invention. The size and the undulation period of the barrier rib undulation pattern in this embodiment have a certain range, and the size and the undulation period of the undulation pattern can be designed according to actual needs in actual production. It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The invention provides a full-color mu LED micro-display device without electrical contact, which comprises: the LED module comprises a transparent lower substrate, a transparent upper substrate, blue light mu LED crystal grains, a wavelength down-conversion light-emitting layer, a control module, a sealing frame body, an exhaust port and a color filter film, wherein the sealing frame body is connected with the transparent upper substrate and the transparent lower substrate; the reflective layer and the lower driving electrode are arranged on the surface of the lower substrate, and the diffusion layer and the upper driving electrode are arranged on the surface of the transparent upper substrate;

the upper driving electrode and the lower driving electrode are arranged on two sides of the blue light mu LED crystal grain, the wavelength down-conversion luminescent layer is arranged between the upper driving electrode and the blue light mu LED crystal grain, and the wavelength down-conversion luminescent layer is arranged between the lower driving electrode and the blue light mu LED crystal grain; the upper driving electrode, the lower driving electrode and the blue mu LED crystal grain are not in direct electrical contact to form an independent space; the control module is respectively electrically connected with the upper driving electrode and the lower driving electrode, the control module provides alternating driving signals for the upper driving electrode and the lower driving electrode, a driving electric field is formed between the upper driving electrode and the lower driving electrode, the driving electric field controls the electron and the hole of the mu LED crystal grain to be combined and emit a first light source, the first light source is converted into a second light source through the wavelength down conversion light emitting layer, and the first light source and the second light source are mixed into a uniform third light source through the reflecting layer and the diffusion layer; the third light source realizes full-color mu LED micro display through the color filter film.

As shown in fig. 1, a full-color μ LED micro-display device without electrical contact is provided in a first embodiment of the present invention, comprising: the light filter comprises a transparent lower substrate 100, a transparent upper substrate 200, blue light mu LED crystal grains, a wavelength down-conversion luminescent layer 300, a control module 800, a sealing frame body 500 and an exhaust sealing and separating port 600 which are connected with the upper transparent substrate and the lower transparent substrate, and a color filter film 700; a reflective layer 110 and a lower driving electrode 120 disposed on the lower substrate surface, and a diffusion layer 210 and an upper driving electrode 220 disposed on the transparent upper substrate surface; it is also characterized in that the method comprises the following steps,

the upper driving electrode 210 and the lower driving electrode 110 are disposed at two sides of the blue μ LED die 400, the wavelength down-conversion light-emitting layer 300 is disposed between the upper driving electrode 210 and the blue μ LED die 400, and the wavelength down-conversion light-emitting layer 300 is disposed between the lower driving electrode 110 and the blue μ LED die 400; there is no direct electrical contact between the upper driving electrode 210, the lower driving electrode 110 and the blue mu LED die 400, forming an independent space; the control module 800 is electrically connected to the upper driving electrode 210 and the lower driving electrode 110, respectively, the control module 600 provides an alternating driving signal for the upper driving electrode 210 and the lower driving electrode 110, and forms a driving electric field between the upper driving electrode 210 and the lower driving electrode 110, the driving electric field controls the electron and the hole of the μ LED die 400 to be combined and emit a first light source 111, the first light source 111 is excited by the wavelength down-conversion light emitting layer to be a second light source 112, the first light source 111 and the second light source 112 are mixed to be a third light source 113, and the third light source 113 passes through the reflective layer and the diffusion layer and then is converted into red light 11, green light 12, and blue light 13 through the color filter film 700 to realize full-color μ LED micro-display.

Referring to fig. 2 and fig. 3, the present invention provides a method for manufacturing a full-color μ LED micro-display device without electrical contact, comprising the following steps:

step S1: providing a transparent upper substrate 200 with a vent 600, and sequentially depositing a diffusion layer 210 and an upper driving electrode 220 on one surface of the transparent upper substrate 200 by physical vapor deposition or chemical vapor deposition or printing or inkjet printing; the diffusion layer 210 mixes the first light source 111 and the second light source 112 to become a third light source 113 which emits light uniformly; the upper driving electrode 220 is a transparent electrode, and the material of the transparent electrode may be, but is not limited to, graphene, indium tin oxide, carbon nanotubes, silver nanowires, copper nanowires, and combinations thereof;

step S2: preparing a color filter film 700 on the surface of the transparent upper substrate 200 by using a photolithography or screen printing method, wherein the R unit 701, the G unit 702 and the B unit 703 of the color filter film correspond to the upper driving electrodes 220 one by one; the R cells, G cells, and B cells are arranged at equal intervals, and the black barrier 704 is directly filled adjacent to each other.

Step S3: providing a transparent lower substrate 100, and depositing a reflective layer 110 and a lower driving electrode 120 on the surface of the transparent lower substrate 100 by physical vapor deposition or chemical vapor deposition or printing or inkjet printing. The reflective layer reflects the first light source 111, the second light source 112, and the third light source 113 formed by mixing the first light source 111 and the second light source, so that the efficiency of the device is improved; the material of the lower driving electrode may be, but not limited to, gold, silver, aluminum, copper, and alloys or stacked structures thereof.

Step S4: coating the frame sealing body 500 around the transparent lower substrate 200 by using a screen printing or ink-jet printing or blade coating method,

step S5: a wavelength down-conversion luminescent layer 300 is provided. The wavelength down-conversion light-emitting layer excites a second light source with longer wavelength under the irradiation of the first light source light emitted by the blue light mu LED crystal grain, and the second light source is yellow light; the wavelength down-conversion light-emitting layer can be arranged on the surfaces of the upper driving electrode and the lower driving electrode, can also be arranged on the outer surface of the mu LED crystal grain, can also be mixed and coated with the mu LED crystal grain, and is arranged in an independent space formed by the upper driving electrode and the lower driving electrode; the wavelength down-conversion luminescent layer is a yellow quantum dot material, can also be a yellow fluorescent powder material, and can also be a mixed material of the yellow quantum dot and the yellow fluorescent powder. This embodiment preferably applies the yellow phosphor 400 on the surfaces of the lower driving electrode 120 and the upper driving electrode 220 by using a printing process.

Step S6: a blue mu LED die is provided. The blue light mu LED crystal grain is formed by connecting a plurality of blue light mu LED chips in series along the vertical direction, can also be formed by connecting a plurality of blue light mu LED chips in parallel along the horizontal direction, and can also be formed by randomly stacking a plurality of blue light mu LED chips; the blue light mu LED chip comprises a p-type semiconductor material, a light-emitting structure and an n-type semiconductor material (the p-type semiconductor material, the light-emitting structure and the n-type semiconductor material can adopt organic materials, inorganic materials or high molecular materials), and the p-type semiconductor material, the light-emitting structure and the n-type semiconductor material are stacked in the vertical direction to form a semiconductor junction; the semiconductor junctions may include, but are not limited to, single semiconductor junctions (pn junctions), semiconductor junctions (pnp, npn junctions), multiple semiconductor junctions, and combinations thereof. The thickness of the P-type semiconductor material is 1nm-2.0 mu m, the thickness of the light-emitting structure is 1nm-1.0 mu m, and the thickness of the N-type semiconductor material is 1nm-2.5 mu m. In this embodiment, a plurality of blue μ LED chips 400 are preferably randomly stacked to form a μ LED die, the P-type semiconductor material 402 has a thickness of 0.2 μm, the light emitting structure 403 has a thickness of 0.1 μm, and the n-type semiconductor material 401 has a thickness of 0.4 μm, as shown in fig. 3.

Step S7: the upper and lower transparent substrates 100, 200 are aligned and sealed, and then removed from the package through the exhaust port 600.

Step S8: a control module 800 is provided. The control module 800 is electrically connected to the upper driving electrode 210 and the lower driving electrode 110, respectively, the control module 800 provides an alternating driving signal for the upper driving electrode 210 and the lower driving electrode 110, and forms a driving electric field between the upper driving electrode 210 and the lower driving electrode 110, the driving electric field controls the electron and hole of the μ LED die to be combined and emit a first light source 111, the first light source is converted into a second light source 112 through 111 the wavelength down-conversion light emitting layer, the second light source is mixed into a uniform third light source 113 through the reflective layer and the diffusion layer, and the uniform third light source 113 is converted into red light 11, green light 12 and blue light 13 through the color filter film 700, so as to realize full-color μ LED micro-display.

Referring to fig. 4, the working principle of a full-color μ LED micro-display device without electrical contact provided by the present invention is as follows: when the control module 800 applies an ac signal, the P-type semiconductor material 402 in the μ LEDs 400 provides holes to diffuse into the light emitting structure 403, the n-type semiconductor material 401 provides electrons to diffuse into the light emitting structure 403, and the electrons and the holes are recombined in the light emitting structure 403 to emit the first light source 111; the first light source 111 excites the yellow quantum dot light emitting layer 300 on the surfaces of the upper driving electrode 220 and the lower driving electrode 110 to emit a second light source 112, and the first light source 111 and the second light source 112 are mixed into a uniform third light source 113 after passing through the reflecting layer 110 and the diffusion layer 210; the third light source 113 is changed into red light 11, green light 12 and blue light 13 through the color filter film 700 to realize full-color micro-LED display.

As shown in fig. 5, a full-color μ LED micro-display device without electrical contact is provided in a second embodiment of the present invention, comprising: the light filter comprises a transparent lower substrate 100, a transparent upper substrate 200, blue light mu LED crystal grains, a wavelength down-conversion luminescent layer 300, a control module 800, a sealing frame body 500 and an exhaust sealing and separating port 600 which are connected with the upper transparent substrate and the lower transparent substrate, and a color filter film 700; a reflective layer 110 and a lower driving electrode 120 disposed on the lower substrate surface, and a diffusion layer 210 and an upper driving electrode 220 disposed on the transparent upper substrate surface;

the upper driving electrode 210 and the lower driving electrode 110 are disposed at two sides of the blue μ LED die 400, the wavelength down-conversion light-emitting layer 300 is disposed between the upper driving electrode 210 and the blue μ LED die 400, and the wavelength down-conversion light-emitting layer 300 is disposed between the lower driving electrode 110 and the blue μ LED die 400; there is no direct electrical contact between the upper driving electrode 210, the lower driving electrode 110 and the blue mu LED die 400, forming an independent space; the control module 800 is electrically connected to the upper driving electrode 210 and the lower driving electrode 110, respectively, the control module 600 provides an alternating driving signal for the upper driving electrode 210 and the lower driving electrode 110, and forms a driving electric field between the upper driving electrode 210 and the lower driving electrode 110, the driving electric field controls the electron and hole of the μ LED die 400 to be combined and emit a first light source 111, the first light source is converted into a second light source 112 through the wavelength down-conversion light emitting layer, and the second light source is converted into red light 11, green light 12 and blue light 13 through the color filter film 700 after passing through the reflective layer and the diffusion layer, so as to realize full-color μ LED micro-display.

Referring to fig. 6 and 7, the present invention provides a method for manufacturing a full-color μ LED micro-display device without electrical contact, comprising the following steps:

step S1: providing a transparent upper substrate 200 with a vent 600, and sequentially depositing a diffusion layer 210 and an upper driving electrode 220 on one surface of the transparent upper substrate 200 by physical vapor deposition or chemical vapor deposition or printing or inkjet printing; the diffusion layer 210 mixes the first light source 111 and the second light source 112 to become a third light source 113 which emits light uniformly; the upper driving electrode 220 is a transparent electrode, and the material of the transparent electrode may be, but is not limited to, graphene, indium tin oxide, carbon nanotubes, silver nanowires, copper nanowires, and combinations thereof;

step S2: preparing a color filter film 700 on the surface of the transparent upper substrate 200 by using a photolithography or screen printing method, wherein the R unit 701, the G unit 702 and the B unit 703 of the color filter film correspond to the upper driving electrodes 220 one by one; the R cells, G cells, and B cells are arranged at equal intervals, and the black barrier 704 is directly filled adjacent to each other.

Step S3: coating the frame sealing body 500 around the transparent lower substrate by using a screen printing or ink-jet printing or blade coating method,

step S4: providing a transparent lower substrate 100, and depositing a reflective layer 110 and a lower driving electrode 120 on the surface of the transparent lower substrate 100 by physical vapor deposition or chemical vapor deposition or printing or inkjet printing. The reflective layer reflects the first light source 111, the second light source 112, and the third light source 113 formed by mixing the first light source 111 and the second light source, so that the efficiency of the device is improved; the material of the lower driving electrode may be, but not limited to, gold, silver, aluminum, copper, and alloys or stacked structures thereof.

Step S5: a blue mu LED die is provided. The blue light mu LED crystal grain is formed by connecting a plurality of blue light mu LED chips in series along the vertical direction, can also be formed by connecting a plurality of blue light mu LED chips in parallel along the horizontal direction, and can also be formed by randomly stacking a plurality of blue light mu LED chips; the blue light mu LED chip comprises a p-type semiconductor material, a light-emitting structure and an n-type semiconductor material, wherein the p-type semiconductor material, the light-emitting structure and the n-type semiconductor material are stacked along the vertical direction to form a semiconductor junction; the semiconductor junctions may include, but are not limited to, single semiconductor junctions (pn junctions), semiconductor junctions (pnp, npn junctions), multiple semiconductor junctions, and combinations thereof. The thickness of the P-type semiconductor material is 1nm-2.0 mu m, the thickness of the light-emitting structure is 1nm-1.0 mu m, and the thickness of the N-type semiconductor material is 1nm-2.5 mu m. In this embodiment, a plurality of blue μ LED chips 400 are preferably randomly stacked to form a μ LED die, the thickness of the P-type semiconductor material 402 is 0.2 μm, the thickness of the light emitting structure 403 is 0.1 μm, and the thickness of the n-type semiconductor material 401 is 0.4 μm.

Step S6: a wavelength down-conversion luminescent layer 300 is provided. The wavelength down-conversion light-emitting layer excites a second light source with longer wavelength under the irradiation of the first light source light emitted by the blue light mu LED crystal grain, and the second light source is yellow light; the wavelength down-conversion light-emitting layer can be arranged on the surfaces of the upper driving electrode and the lower driving electrode, can also be arranged on the outer surface of the mu LED crystal grain, can also be mixed and coated with the mu LED crystal grain, and is arranged in an independent space formed by the upper driving electrode and the lower driving electrode; the wavelength down-conversion luminescent layer is a yellow quantum dot material, can also be a yellow fluorescent powder material, and can also be a mixed material of the yellow quantum dot and the yellow fluorescent powder. In this embodiment, the yellow phosphor 300 and the blue μ LED chip 400 are preferably uniformly mixed, the μ LED chip and the wavelength down-conversion luminescent layer are mixed and coated together, and the mixture is disposed on the surface of the lower driving electrode 120 by using a screen printing or ink-jet printing or spray coating or spin coating method.

Step S7: the upper and lower transparent substrates 100, 200 are aligned and sealed, and then removed from the package through the exhaust port 600.

Step S8: a control module 800 is provided. The control module 800 is electrically connected to the upper driving electrode 210 and the lower driving electrode 110, respectively, the control module 800 provides an alternating driving signal for the upper driving electrode 210 and the lower driving electrode 110, and forms a driving electric field between the upper driving electrode 210 and the lower driving electrode 110, the driving electric field controls the electron and hole of the μ LED die to be combined and emit a first light source 111, the first light source is converted into a second light source 112 through the wavelength down-conversion light emitting layer 111, and the second light source is converted into red light 11, green light 12 and blue light 13 through the color filter film 700 after passing through the reflective layer and the diffusion layer, so as to realize full-color μ LED micro-display.

Referring to fig. 8, the working principle of a full-color μ LED micro-display device without electrical contact is as follows: when the control module 800 applies an alternating signal, holes are provided by the P-type semiconductor material 402 in the plurality of μ LED chips 400 to be diffused to the light emitting structure 403, electrons are provided by the n-type semiconductor material 401 to be diffused to the light emitting structure 403, and the electrons and the holes are recombined in the light emitting structure 403 to emit the first light source 111; the first light source 111 excites the yellow fluorescent powder luminescent layer 300 on the surface of the mu LED chip 400 to emit a second light source 112, and the first light source 111 and the second light source 112 are mixed into a uniform third light source 113 after passing through the reflecting layer 110 and the diffusion layer 210; the third light source 113 is changed into red light 11, green light 12 and blue light 13 through the color filter film 700 to realize full-color micro-LED display.

The above are preferred embodiments of the present invention, and all changes made according to the technical scheme of the present invention that produce functional effects do not exceed the scope of the technical scheme of the present invention belong to the protection scope of the present invention.