阅读说明：本技术 一种显示装置 (Display device ) 是由 李富琳 于 2020-06-10 设计创作，主要内容包括：本发明公开了一种显示装置,包括：微型发光二极管灯板,微型发光二极管灯板上包括反光层,反光层靠近开口的区域的厚度小于反光层远离开口的区域的厚度,以对微型发光二极管附近的反光层进行减薄处理,避免微型发光二极管在焊接过程中搭接在反光层而不能被拉正的问题,提高微型发光二极管的焊接良率；同时,反光层在除开口附近以外的区域还具有较大的厚度,由此来保证反光层的大部分区域具有较高的反射率,从而保证大部分光线均可以被有效反射,使得微型发光二极管灯板的出光效率不被影响。(The invention discloses a display device, comprising: the miniature LED lamp panel comprises a reflecting layer, the thickness of a region of the reflecting layer close to the opening is smaller than that of a region of the reflecting layer far away from the opening, so that the reflecting layer close to the miniature LED is thinned, the problem that the miniature LED cannot be pulled right due to the fact that the miniature LED is lapped on the reflecting layer in the welding process is avoided, and the welding yield of the miniature LED is improved; simultaneously, the reflector layer still has great thickness in the region except that near the opening, guarantees from this that most regions of reflector layer have higher reflectivity to guarantee that most light all can be effectively reflected, make the luminous efficacy of miniature emitting diode lamp plate not influenced.)

1. A display device, comprising:

a display panel for image display;

the miniature light-emitting diode lamp panel is positioned at the light incident side of the display panel and used for providing backlight;

the miniature LED lamp plate includes:

a circuit board for providing a driving signal;

the micro light-emitting diode is positioned on the circuit board;

the light reflecting layer is positioned on the surface of one side of the circuit board close to the micro light-emitting diode and is provided with an opening for exposing the micro light-emitting diode;

the thickness of the area of the light reflecting layer close to the opening is smaller than that of the area of the light reflecting layer far away from the opening.

2. The display device according to claim 1, wherein the material used for the light reflecting layer is white ink.

3. The display device of claim 2, wherein the thickness of the area of the light reflecting layer adjacent to the opening is less than half the height of the micro light emitting diode.

4. The display device according to claim 3, wherein a region of the light-reflecting layer adjacent to the opening is a first region, and a region other than the first region is a second region;

the thickness of the first region is 20-40 μm; the thickness of the second region is 50 μm to 80 μm.

5. The display device according to claim 4, wherein the first region is an annular region, an outer contour of the first region is a circle, and an inner contour of the first region is a rectangle.

6. The display device according to claim 5, wherein a diameter size of an outer contour of the first region is 2 to 5 times a maximum size of an inner contour of the first region.

7. The display device according to claim 5, wherein the circuit board is rectangular in shape, and the micro light emitting diodes are rectangular in shape;

the short side direction of the micro light-emitting diode is parallel to the long side direction of the circuit board, and the long side direction of the micro light-emitting diode is parallel to the short side direction of the circuit board.

8. The display device according to claim 7, wherein a length of a side of the opening parallel to a long side direction of the micro light emitting diode is 1.1 to 1.4 times a length of a long side of the micro light emitting diode;

the length of the side of the opening parallel to the short side direction of the micro light-emitting diode is 1.3-1.7 times of the length of the short side of the micro light-emitting diode.

9. The display device of claim 5, wherein the micro light emitting diode lamp panel further comprises:

the packaging layer covers the surface of one side of the miniature light-emitting diode, which is far away from the circuit board, and the packaging layer is provided with a dot matrix pattern covering the miniature light-emitting diode;

the edge of the packaging layer is positioned in the outer contour of the first area; or the edge of the packaging layer is coincided with the outer contour of the first area.

10. The display device of claim 5, wherein the micro light emitting diode lamp panel further comprises:

and the whole packaging layer covers the surfaces of the miniature light-emitting diodes and the side, which deviates from the circuit board, of the reflecting layer.

Technical Field

The invention relates to the technical field of display, in particular to a display device.

Background

The liquid crystal display screen has the advantages of low power consumption, small volume, low radiation and the like as the current mainstream display screen. The liquid crystal display panel is a non-self-luminous panel and needs to be matched with a backlight module for use.

The micro Light Emitting Diode (Mini LED) has become a current hotspot in the liquid crystal display technology as a backlight, which is different from the traditional liquid crystal display backlight scheme adopting a side-in type Light guide plate, and a huge amount of Mini LEDs are adopted as the backlight source, so that not only can the backlight be thinned, but also more refined dynamic control can be realized, and the dynamic contrast of the liquid crystal display is improved.

The surface of the existing Mini LED lamp panel is provided with a layer of reflective material, and the reflectivity and the thickness of the reflective material are in positive correlation. When the thickness of the reflecting material is larger, the reflectivity of the reflecting material is high, but the welding yield of the Mini LED is influenced; when the thickness of the reflecting material is smaller, the welding yield of the Mini LED can be improved, but the reflectivity of the Mini LED is lower, so that the light emitting efficiency is influenced.

Disclosure of Invention

In some embodiments of the invention, the display device comprises a micro light-emitting diode lamp panel, the micro light-emitting diode lamp panel comprises a reflecting layer, the thickness of the area of the reflecting layer close to the opening is smaller than that of the area of the reflecting layer far away from the opening, so as to thin the reflecting layer near the micro light-emitting diode, avoid the problem that the micro light-emitting diode is overlapped on the reflecting layer in the welding process and cannot be pulled forward, and improve the welding yield of the micro light-emitting diode; simultaneously, the reflector layer still has great thickness in the region except near the opening, guarantees from this that most regions of reflector layer have higher reflectivity to guarantee that most light all can be effectively reflected, make the luminous efficacy of miniature emitting diode lamp plate not influenced.

In some embodiments of the invention, the thickness of the area of the light reflecting layer close to the opening is less than half of the height of the micro light emitting diode, so that the problem that the micro light emitting diode is turned over at the edge lapped on the light reflecting layer can be avoided.

In some embodiments of the invention, the area of the light reflecting layer close to the opening is a first area, the area except the first area is a second area, and the thickness of the first area of the light reflecting layer is 20-40 μm, so that poor welding of the micro light emitting diode caused by overlarge thickness of the light reflecting layer at the edge of the opening is avoided; the thickness of the second area of the light reflecting layer is 50-80 μm, so that the reflectivity of the light reflecting layer in the second area is ensured to be more than 95%.

In some embodiments of the present invention, the first region is an annular region, an outer contour of the first region is a circle, and an inner contour of the first region is a rectangle.

In some embodiments of the invention, the outer contour of the first region has a diametrical dimension 2-5 times the largest dimension of the inner contour of the first region. Therefore, even if the circuit board has the problem of expansion and shrinkage, the micro light-emitting diode at most contacts the first area of the reflecting layer in the welding process, can be pulled right in the reflow welding process, and the problem of poor welding can not occur.

In some embodiments of the present invention, the circuit board is rectangular, and the micro light emitting diode is also rectangular. Because the expansion and shrinkage of the circuit board in the long edge direction are larger, in order to ensure the welding yield of the micro light-emitting diode, the long edge of the micro light-emitting diode is arranged to be parallel to the short edge of the circuit board, and the short edge of the micro light-emitting diode is arranged to be parallel to the long edge of the circuit board.

In some embodiments of the invention, the expansion and shrinkage of the circuit board in the long side direction is relatively large, the offset of the opening of the light reflecting layer along with the circuit board is relatively large, the long side direction of the circuit board is parallel to the short side direction of the micro light-emitting diode, and the length of the side of the opening parallel to the short side direction of the micro light-emitting diode is set to be 1.3-1.7 times of the length of the short side of the micro light-emitting diode, so that the micro light-emitting diode can be ensured to fall in the opening range in the short side direction in the welding process.

In some embodiments of the invention, the expansion and shrinkage of the circuit board in the short side direction is relatively small, the offset of the opening of the light reflecting layer along with the circuit board is relatively small, the short side direction of the circuit board is parallel to the long side direction of the micro light-emitting diode, and the length of the long side of the opening parallel to the long side direction of the micro light-emitting diode is set to be 1.1-1.4 times of the length of the long side of the micro light-emitting diode, so that the micro light-emitting diode can be ensured to fall in the opening range in the long side direction in the welding process.

In some embodiments of the present invention, the encapsulation layer has a dot pattern covering the micro light emitting diode, and the encapsulation layer is used for encapsulating and protecting the micro light emitting diode, so that an excessive size does not need to be set, and an edge of the encapsulation layer may be located within an outer contour of the first area, or the edge of the encapsulation layer may coincide with the outer contour of the first area.

In some embodiments of the invention, the whole packaging layer covers the surfaces of the miniature light-emitting diodes and the side of the light reflecting layer, which is far away from the circuit board, so that the packaging efficiency of the miniature light-emitting diode lamp panel is improved on the basis of ensuring the welding yield of the miniature light-emitting diodes.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic cross-sectional structure diagram of a display device according to an embodiment of the present invention;

fig. 2 is a schematic cross-sectional view of a backlight module according to an embodiment of the invention;

FIG. 3 is a graph of the thickness of a light-reflecting layer versus reflectivity according to an embodiment of the present invention;

FIG. 4 is a second schematic cross-sectional view illustrating a backlight module according to an embodiment of the present invention;

fig. 5 is a schematic top view of a miniature led lamp panel according to an embodiment of the present invention;

fig. 6 is a schematic partial enlarged view of a miniature led lamp panel according to an embodiment of the present invention;

fig. 7 is a third schematic cross-sectional view of a backlight module according to an embodiment of the invention.

The backlight module comprises a backlight module 100, a display panel 200, a back panel 11, a micro light emitting diode lamp panel 12, a diffusion plate 13, an optical diaphragm 14, a circuit board 121, a micro light emitting diode 122, a light reflecting layer 123, a packaging layer 124, a first area S1, a second area S2 and a k opening.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, the present invention is further described with reference to the accompanying drawings and examples. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their repetitive description will be omitted. The words expressing the position and direction described in the present invention are illustrated in the accompanying drawings, but may be changed as required and still be within the scope of the present invention. The drawings of the present invention are for illustrative purposes only and do not represent true scale.

The liquid crystal display mainly comprises a backlight module and a liquid crystal display panel. The liquid crystal display panel does not emit light, and brightness display needs to be realized by a light source provided by the backlight module.

The display principle of the liquid crystal display is that liquid crystal is placed between two pieces of conductive glass, and the electric field effect of liquid crystal molecule distortion is caused by the driving of an electric field between two electrodes so as to control the transmission or shielding function of a backlight source, thereby displaying an image. If a color filter is added, a color image can be displayed.

Fig. 1 is a schematic cross-sectional structure diagram of a display device according to an embodiment of the present invention.

Referring to fig. 1, the display device includes: the backlight module 100 is used for providing backlight to the display panel 200, and the display panel 200 is used for displaying images.

The backlight module 100 is generally disposed at the bottom of the display device, and has a shape and size corresponding to those of the display device. When applied to the field of televisions or mobile terminals, the backlight module generally takes a rectangular shape.

The backlight module in the embodiment of the invention adopts the direct type backlight module, is used for uniformly emitting light rays in the whole light emitting surface, and provides light rays with sufficient brightness and uniform distribution for the display panel, so that the display panel can normally display images.

The display panel 200 is located at the light-emitting side of the backlight module 100, and the shape and size of the display panel are generally matched with those of the backlight module. In general, the display panel 200 may be configured in a rectangular shape including a top side, a bottom side, a left side and a right side, wherein the top side is opposite to the bottom side, the left side is opposite to the right side, the top side is connected to one end of the left side and one side of the right side, and the bottom side is connected to the other end of the left side and the other end of the right side.

The display panel 200 is a transmissive display panel, which can modulate the transmittance of light, but does not emit light by itself. The display panel 200 has a plurality of pixel units arranged in an array, and each pixel unit can independently control the transmittance and color of light incident to the pixel unit from the backlight module 100, so that the light transmitted by all the pixel units forms a displayed image.

Fig. 2 is a schematic cross-sectional view of a backlight module according to an embodiment of the invention.

Referring to fig. 2, along the light-emitting direction of the light in the backlight module, the backlight module sequentially includes: the backlight module comprises a back plate 11, a micro light-emitting diode lamp panel 12, a diffusion layer 13 and an optical diaphragm 14.

The back plate 11 is located at the bottom of the backlight module and has supporting and bearing functions. The back plate 11 is typically a rectangular structure, the shape of which is adapted to the shape of the display device when applied to a contoured display device. The back panel 11 includes a top side, a bottom side, a left side, and a right side. Wherein the antenna side is opposite to the ground side, the left side is opposite to the right side, the antenna side is connected with one end of the left side and one side of the right side respectively, and the ground side is connected with the other end of the left side and the other end of the right side respectively.

The material of the back plate 11 is aluminum, iron, aluminum alloy or iron alloy. The back plate 11 is used for fixing the edge positions of the miniature led lamp panel 12 and supporting and fixing the diffusion plate 13, the optical diaphragm 14 and other components, and the back plate 11 also plays a role in heat dissipation of the miniature led lamp panel 12.

In the embodiment of the present invention, the backlight module is a direct type backlight module, and the micro led lamp panel 12 is located on the back plate 11. In general, the whole of the micro led lamp panel 12 may be square or rectangular, with a length of 200mm-800mm and a width of 100mm-500 mm.

According to the size of the display device, a plurality of miniature light-emitting diode lamp panels 12 can be arranged, and backlight is provided between the miniature light-emitting diode lamp panels 12 in a splicing mode. In order to avoid the optical problem caused by splicing the miniature light-emitting diode lamp panels 12, the splicing seams between the adjacent miniature light-emitting diode lamp panels 12 are as small as possible, and even seamless splicing is realized.

The micro light emitting diodes in the micro light emitting diode lamp panel 12 are used as a backlight source, and compared with the traditional light emitting diodes, the light emitting diode lamp panel has a smaller size, can realize more refined dynamic control, and improves the dynamic contrast of the display device.

Referring to fig. 2, the miniature led lamp panel 12 specifically includes: a circuit board 121, micro light emitting diodes 122, a light reflecting layer 123 and an encapsulation layer 124.

The circuit board 121 is located on the back plate 11, and the shape of the circuit board 121 is the same as the overall shape of the micro led lamp panel 12. In general, the circuit board 121 has a plate shape, and has a rectangular or square shape as a whole. The length of the circuit board 121 is 200mm-800mm, and the width is 100mm-500 mm.

In the embodiment of the present invention, the Circuit Board 121 may be a Printed Circuit Board (PCB), where the PCB includes an electronic Circuit and an insulating layer, and the insulating layer exposes a pad of the electronic Circuit, on which the micro light emitting diode 122 is soldered, and covers the rest of the electronic Circuit.

Alternatively, the circuit board 121 may also be an array substrate formed by fabricating a thin film transistor driving circuit on a substrate, and the surface of the array substrate has a connection electrode connected to the thin film transistor driving circuit for soldering the micro light emitting diode 122.

The substrate or base plate of the circuit board 121 may be made of FR4 or glass. Alternatively, the substrate or the substrate base plate of the circuit board 121 may be made of a flexible material to form a flexible display device.

The circuit board 121 is used for providing a driving electrical signal for the micro light emitting diode 122. The micro light emitting diode 122 and the circuit board 121 are separately manufactured, the surface of the circuit board 121 includes a plurality of bonding pads for soldering the micro light emitting diode 122, the micro light emitting diode 122 is transferred to the bonding pads after the manufacturing, and the micro light emitting diode 122 is soldered on the circuit board 121 through processes such as reflow soldering, so that the micro light emitting diode 122 can be driven to emit light by controlling an input signal of the circuit board 121.

The micro light emitting diodes 122 are located on the circuit board. The electrodes of the micro leds 122 are soldered to the exposed pads of the circuit board 121, so as to electrically connect the two.

The micro light emitting diode 122 is different from a general light emitting diode, and is specifically referred to as a micro light emitting diode chip. The small size of the micro-leds 122 is advantageous for controlling the dynamic light emission of the backlight module to a smaller sub-area, which is advantageous for improving the contrast of the image. In the embodiment of the present invention, the size of the micro light emitting diode 122 is below 500 μm.

The micro led lamp panel 12 may include only one color of micro leds 122, and may also include multiple colors of micro leds 122, which is not limited herein.

The reflective layer 123 is disposed on a surface of the circuit board 121 near the micro light emitting diodes 122. The reflective layer 123 has the same shape as the circuit board 121, and the reflective layer 123 includes a plurality of openings for exposing the micro light emitting diodes 122.

The reflective layer 123 is a protective layer on the surface of the circuit board 121, and has functions of protecting the circuit board and diffusely reflecting incident light. In the embodiment of the present invention, the light reflecting layer 123 may be coated on the surface of the circuit board 121 by using a material with light reflecting property such as white ink, and then the position where the pad for soldering the micro light emitting diode 122 is exposed by etching or the like, so as to form an opening for exposing the micro light emitting diode 122.

The reflective layer 123 has a property of reflecting light, so that light emitted from the micro led lamp panel 12 to one side of the back plate 11 or light reflected back to one side of the back plate by an element in the backlight module can be reflected by the reflective layer 123 to the light emitting side again, thereby improving the utilization efficiency of the light source.

The encapsulation layer 124 covers the surface of the micro light emitting diode 122 on the side away from the circuit board 121. The encapsulation layer 124 is used for encapsulating and protecting the micro light emitting diode 122 and blocking foreign matters from entering the interior of the micro light emitting diode 122. In the embodiment of the invention, the encapsulation layer 124 may be made of a transparent colloid material, such as a transparent silicone, a modified silicone, or an epoxy resin. The encapsulation layer 124 may be applied by spot coating or full coating.

The diffusion plate 13 is located on the light-emitting side of the micro led lamp panel 12, and the shape of the diffusion plate 13 is the same as that of the micro led lamp panel 12. The diffuser plate 13 may be provided in a rectangular or square shape in a general case.

The diffuser 13 functions to scatter incident light, making the light passing through the diffuser 13 more uniform. The diffusion plate 13 is provided with scattering particle materials, and light incident to the scattering particle materials can be refracted and reflected continuously, so that the effect of scattering the light is achieved, and the effect of light uniformization is achieved.

The thickness of the diffusion plate 13 is 1.5mm-3mm, which has higher haze and more uniform effect, and the diffusion plate 13 can be processed by an extrusion process, and the material used for the diffusion plate 13 is generally selected from at least one of polymethyl methacrylate (PMMA), Polycarbonate (PC), polystyrene material (PS) and polypropylene (PP).

The optical film 14 is located on one side of the diffusion plate 13 away from the micro led lamp panel 12, and the optical film 14 is disposed in a whole layer, and has the same shape as the micro led lamp panel 12, and may be disposed in a rectangular or square shape in general.

The optical film 14 can be disposed to adapt the backlight module to various practical applications.

When the micro led 122 in the micro led lamp panel 12 is a blue micro led, the optical film 14 includes a quantum dot layer or a fluorescent layer.

The quantum dot layer comprises a red quantum dot material and a green quantum dot material, the red quantum dot material emits red light under the excitation of blue light, the green quantum dot material emits green light under the excitation of the blue light, and the red light, the green light and the transmitted blue light which are emitted by excitation are mixed to form white light for emitting.

The fluorescent layer comprises fluorescent materials which are stimulated to emit red light and green light, and the stimulated red light, the green light and the transmitted blue light are mixed into white light to be emitted.

In addition, the optical film 14 may further include a prism sheet, which can change the exit angle of light, thereby changing the viewable angle of the display device.

The optical film 14 may further include a reflective polarizer, which is a brightness enhancement film, and can improve the brightness of the backlight module, improve the utilization efficiency of light, and make the emergent light have polarization property, thereby omitting the use of the polarizer under the lcd panel.

In the conventional direct type backlight module, the LEDs are usually adopted as the backlight source, and the backlight module is provided with the perforated reflector plate in order to improve the light extraction rate, while the backlight module in the embodiment of the invention adopts the Mini LEDs, compared with the conventional backlight module, the number of the Mini LEDs is large, and generally reaches ten thousand Mini LEDs, so that if the whole reflector plate is adopted, the number of the perforated reflector plate is greatly increased, the mounting difficulty is increased, and the efficiency is reduced.

In view of this, in the embodiment of the invention, the surface of the circuit board 121 is coated with the reflective layer 123 with a relatively high reflectivity, the reflective layer 123 is usually white ink, the relationship between the reflectivity and the thickness of the white ink is shown in fig. 3, the reflectivity and the thickness of the white ink (referred to as white oil for short) are in a positive correlation, the larger the thickness of the white oil is, the higher the reflectivity is, and the smaller the thickness of the white oil is, the lower the reflectivity is. If the reflectance of the white ink layer is required to be 95% or more, the thickness of the white ink layer is required to be 50 μm to 55 μm or more.

The micro leds 122 are usually fabricated separately from the circuit board 121, and the micro leds need to be transferred to the circuit board 121 to be fabricated into the micro led lamp panel 12 by soldering.

Firstly, the solder paste is printed on the circuit board 121, and usually, the solder paste is printed through a steel mesh, and an opening is formed in the steel mesh at a position corresponding to the pad for soldering the Mini LED, and then the solder paste falls on the pad of the circuit board 121 through the opening of the steel mesh in the process of printing the solder paste. Then, the micro light emitting diode 122 is transferred to a bonding pad of the circuit board 121, and after being heated at a high temperature in a reflow furnace, the solder paste is melted and then solidified, and the micro light emitting diode 122 is soldered on the circuit board 121 through the solder paste.

In the soldering process of the micro led 122, the position of the bonding pad is shifted due to the expansion and contraction of the circuit board, at this time, the edge of the micro led 122 may be lapped on the white ink (white oil for short) layer beside the bonding pad, and if the thickness of the white oil is thinner, the micro led 122 can be pulled right in the solder paste melting process, so that the final soldering yield is not affected. However, if the thickness of the white oil is thick (for example, 50 μm), the micro light emitting diode 122 is not easily pulled right after the solder paste is melted, and the micro light emitting diode 122 may be turned over, which may affect the bonding yield. However, the use of a thinner white oil will reduce the reflectivity of the white oil, thereby affecting the light extraction efficiency.

In view of the above problem, referring to fig. 2, the embodiment of the invention provides an opening k at a position of the light reflecting layer 123 corresponding to the micro light emitting diode 122, thereby exposing the micro light emitting diode. And thinning the area S of the light reflecting layer 123 close to the opening k, so that the thickness of the area of the light reflecting layer 123 close to the opening k is smaller than that of the area of the light reflecting layer 123 far away from the opening k. The reflecting layer 123 has a smaller thickness in the area close to the opening k, so that the problem that the micro light-emitting diode 122 cannot be pulled right due to the fact that the reflecting layer 123 is lapped on the micro light-emitting diode 122 in the welding process is avoided, and the welding yield of the micro light-emitting diode 122 is improved; meanwhile, the reflective layer 123 still has a large thickness in most of the areas far away from the opening k, so that it is ensured that most of the areas of the reflective layer 123 have a high reflectivity, and most of the light can be effectively reflected, so that the light-emitting efficiency of the miniature led lamp panel 12 is not affected.

In the embodiment of the present invention, as shown in fig. 2, the area of the reflective layer 123 near the opening k may be set to be a stepped structure, so that the thicknesses of the reflective layer 123 in different areas may be flexibly set, thereby adjusting the reflectivity of the reflective layer 123.

In order to avoid the problem of the micro light emitting diode 122 turning over during the soldering process, the thickness of the area of the light reflecting layer 123 close to the opening is less than half of the height of the micro light emitting diode 122.

The structure of the display device according to the embodiment of the present invention will be specifically described below by taking the example of dividing the light-reflecting layer 123 into two regions.

Fig. 4 is a second schematic cross-sectional structure diagram of the backlight module according to the embodiment of the invention, and fig. 5 is a schematic top-view structure diagram of the micro light-emitting diode lamp panel according to the embodiment of the invention. Referring to fig. 4 and 5, the light-reflecting layer 123 includes a first region S1 near the opening k and a second region S2 except the first region, and the thickness of the first region S1 of the light-reflecting layer 123 adjacent to the micro light-emitting diode 122 is smaller than that of the second region S2, so as to thin the first region S1 near the micro light-emitting diode 122, avoid the problem that the micro light-emitting diode 122 is overlapped on the light-reflecting layer and cannot be pulled forward in the welding process, and improve the welding yield of the micro light-emitting diode; meanwhile, the reflective layer 123 has a larger thickness in the second region S2 except for the first region S1 near the opening k, so that the second region S2 of the reflective layer has a higher reflectivity, and most of light can be effectively reflected, so that the light extraction efficiency of the micro light-emitting diode lamp panel is not affected.

The height of the micro-leds 122 is about 100 μm, and when the thickness of the light reflecting layer near the bonding pads exceeds more than half of the height of the micro-leds 122, the micro-leds 122 are liable to flip at the edge overlapping the light reflecting layer 123, and in order to avoid the above problem, the embodiment of the present invention sets the thickness of the first region S1 of the light reflecting layer 123 to be less than half of the height of the micro-leds 122.

The height of the micro light emitting diode 122 is about half 50 μm to 80 μm, and the thickness of the first region S1 of the light reflecting layer 123 near the opening k may be set in the range of 20 μm to 40 μm. The other areas of the light reflecting layer 123 except the first area S1 need to have higher reflectivity, and according to the relation between the reflectivity and the thickness shown in fig. 3, the thickness of the second area S2 is set to be 50 μm-80 μm, so that the reflectivity of the light reflecting layer 123 in the second area S2 can be ensured to reach more than 95%.

Fig. 6 is a partially enlarged view of the miniature led lamp panel according to the embodiment of the present invention.

Referring to fig. 5 and 6, in the embodiment of the present invention, the first region S1 is an annular region, the outer contour of the first region S1 may be set to be circular, and the inner contour of the first region S1 is the shape of the opening k, and the opening k is normally set to be rectangular.

Since the resin material generally used for the substrate of the circuit board 121 has a problem of expansion and contraction after the processes such as the respective process steps and the transportation, the embodiment of the present invention sets the diameter d of the outer contour of the first area S1 to be 2 to 5 times the maximum dimension S of the inner contour of the first area S1 in consideration of the expansion and contraction dimension. Therefore, even if the circuit board has the problem of expansion and contraction, the micro light-emitting diode 122 at most contacts the first area S1 of the reflecting layer in the welding process, can be pulled right in the reflow welding process, and the problem of poor welding can not occur.

In the embodiment of the present invention, the circuit board 121 is rectangular, and the micro light emitting diode 122 is also rectangular. Referring to fig. 5, the long sides of the circuit board are parallel to the x-direction and the short sides of the circuit board are parallel to the y-direction. Because the expansion and contraction amount of the circuit board in the long side direction x is larger, in order to ensure the welding yield of the micro light-emitting diode 122, the long side of the micro light-emitting diode 122 is arranged to be parallel to the short side of the circuit board, and the short side direction of the micro light-emitting diode 122 is arranged to be parallel to the long side direction of the circuit board.

The expansion and contraction amount of the circuit board in the long side direction x is relatively large, so that the offset generated by the opening k of the light reflecting layer 123 along with the circuit board is relatively large, and the long side direction x of the circuit board is parallel to the short side direction of the micro light emitting diode 122, therefore, the length of the side of the opening k parallel to the short side direction of the micro light emitting diode 122 is set to be 1.3-1.7 times of the length of the short side of the micro light emitting diode 122, and the micro light emitting diode 122 can be ensured to fall in the range of the opening k in the short side direction in the welding process.

The expansion and contraction amount of the circuit board in the short side direction y is relatively small, so that the offset generated by the opening k of the light reflecting layer 123 along with the circuit board is relatively small, and the short side direction y of the circuit board is parallel to the long side direction of the micro light emitting diode 122, therefore, the length of the long side of the opening k parallel to the long side direction of the micro light emitting diode 122 is set to be 1.1-1.4 times of the length of the long side of the micro light emitting diode 122, and the micro light emitting diode 122 can be ensured to fall in the range of the opening k in the long side direction in the welding process.

When the micro light emitting diode 122 is packaged by using the packaging adhesive, two forms of dispensing and whole layer gluing can be adopted. The glue dispensing and packaging mode can save packaging glue materials and reduce the cost; and the whole layer of gluing mode has higher packaging efficiency.

Referring to fig. 4 and 5, in the embodiment of the invention, the encapsulation layer 124 covers only the surface of the micro light emitting diode 122 on the side away from the circuit board 121, and the encapsulation layer 124 has a dot pattern covering the micro light emitting diode 122.

The shape of the encapsulation layer 124 is naturally formed by dispensing glue on the surface of the micro light emitting diode 122 and then performing diffusion, curing, etc., and the outer contour is generally similar to a circle, and since the encapsulation layer 124 serves to encapsulate and protect the micro light emitting diode, an excessive size does not need to be set, and the edge of the encapsulation layer 124 may be located within the outer contour of the first region S1, or the edge of the encapsulation layer 124 may coincide with the outer contour of the first region S1.

Fig. 7 is a third schematic cross-sectional view of a backlight module according to an embodiment of the invention.

Referring to fig. 7, in another embodiment of the present invention, the encapsulation layer 124 entirely covers the micro light emitting diodes 122 and the surface of the reflection layer 123 facing away from the circuit board 121. Therefore, the packaging efficiency of the miniature light-emitting diode lamp panel is improved on the basis of ensuring the welding yield of the miniature light-emitting diode.

According to the first invention concept, the thickness of the area of the reflecting layer close to the opening is smaller than that of the area of the reflecting layer far away from the opening, so that the reflecting layer near the micro light-emitting diode is thinned, the problem that the micro light-emitting diode is overlapped on the reflecting layer in the welding process and cannot be pulled forward is avoided, and the welding yield of the micro light-emitting diode is improved; simultaneously, the reflector layer still has great thickness in the second region except that near the opening, guarantees from this that most region of reflector layer has higher reflectivity to guarantee that most light all can be effectively reflected, make the luminous efficacy of miniature emitting diode lamp plate not influenced.

According to the second inventive concept, the thickness of the area of the light reflecting layer close to the opening is less than half of the height of the micro light emitting diode, so that the problem that the micro light emitting diode is turned over at the edge overlapped with the light reflecting layer can be avoided.

According to the third inventive concept, the area of the light reflecting layer close to the opening is a first area, the area except the first area is a second area, and the thickness of the first area of the light reflecting layer is 20-40 μm, so that poor welding of the micro light emitting diode caused by overlarge thickness of the light reflecting layer at the edge of the opening is avoided; the thickness of the second area of the light reflecting layer is 50-80 μm, so that the reflectivity of the light reflecting layer in the second area is ensured to be more than 95%.

According to a fourth inventive concept, the outer contour of the first region has a diameter size 2-5 times the maximum size of the inner contour of the first region. Therefore, even if the circuit board has the problem of expansion and shrinkage, the micro light-emitting diode at most contacts the first area of the reflecting layer in the welding process, can be pulled right in the reflow welding process, and the problem of poor welding can not occur.

According to the fifth inventive concept, the circuit board is rectangular in shape, and the micro light emitting diode is also rectangular in shape. Because the expansion and shrinkage of the circuit board in the long edge direction are larger, in order to ensure the welding yield of the micro light-emitting diode, the long edge of the micro light-emitting diode is arranged to be parallel to the short edge of the circuit board, and the short edge of the micro light-emitting diode is arranged to be parallel to the long edge of the circuit board.

According to the sixth inventive concept, the expansion and contraction amount of the circuit board in the long side direction is relatively large, the offset of the opening of the light reflecting layer along with the circuit board is relatively large, the long side direction of the circuit board is parallel to the short side direction of the micro light-emitting diode, the length of the side of the opening parallel to the short side direction of the micro light-emitting diode is set to be 1.3-1.7 times of the length of the short side of the micro light-emitting diode, and the micro light-emitting diode can be ensured to fall in the opening range in the short side direction in the welding process. The expansion and shrinkage of the circuit board in the short side direction are relatively small, the offset of the opening of the reflecting layer along with the circuit board is relatively small, the short side direction of the circuit board is parallel to the long side direction of the micro light-emitting diode, the length of the long side of the opening parallel to the long side direction of the micro light-emitting diode is set to be 1.1-1.4 times of the length of the long side of the micro light-emitting diode, and the micro light-emitting diode can be ensured to fall in the opening range in the long side direction in the welding process.

According to the seventh inventive concept, the encapsulation layer has a dot pattern covering the micro light emitting diode, and the encapsulation layer is used for encapsulating and protecting the micro light emitting diode, so that an excessive size does not need to be set, and the edge of the encapsulation layer can be located within the outer contour of the first area, or the edge of the encapsulation layer is overlapped with the outer contour of the first area.

According to the eighth invention concept, the whole packaging layer covers the surfaces of the miniature light-emitting diodes and the side of the reflecting layer, which is far away from the circuit board, so that the packaging efficiency of the miniature light-emitting diode lamp panel is improved on the basis of ensuring the welding yield of the miniature light-emitting diodes.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.