CN117055265A - Backlight module, preparation method thereof and display device - Google Patents

Abstract

The embodiment of the disclosure discloses a backlight module, a preparation method thereof and a display device. In an embodiment, the backlight module comprises a substrate, a reflective layer, a plurality of light emitting units, a plurality of first structures and a plurality of lenses, wherein the reflective layer is arranged on the substrate, the reflective layer is provided with a plurality of first openings, the first structures are provided with through holes, the light emitting units are arranged in the first openings and in the through holes, and the lenses are arranged on one side, far away from the substrate, of the first structures and cover the light emitting sides of the light emitting units. According to the embodiment, the light homogenizing effect can be effectively improved on the basis of guaranteeing the waterproof vapor packaging effect of the light-emitting units, so that the design with larger space between the light-emitting units is possible under the condition that the backlight brightness and the light homogenizing effect requirements are met, the consumption of the light-emitting units is reduced, and the cost is reduced.

Description

Backlight module, preparation method thereof and display device

Technical Field

The present disclosure relates to the field of display technology. More particularly, the invention relates to a backlight module, a preparation method thereof and a display device.

Background

In the related art, an inactive Light Emitting display device such as a liquid crystal display device (Liquid Crystal Display, LCD) generally uses a matrix LED (Light-Emitting Diode) or COB (Chip on Board), i.e., an LED Chip is directly mounted on a substrate such as a PCB Board with driving wires embedded therein, as a Backlight unit (BLU) of a display panel. The COB backlight module has a problem of poor light uniformity, if the number of light emitting units such as LEDs is increased, the pitch of the light emitting units is reduced, and although the light uniformity effect can be improved, the product cost including the BOM cost (consumable cost) of the light emitting units is increased, and the power consumption of the backlight module is increased.

Disclosure of Invention

The disclosure provides a backlight module, a manufacturing method thereof and a display device, which are used for solving at least one of the problems existing in the prior art.

In order to achieve the above purpose, the present disclosure adopts the following technical scheme:

the first aspect of the present disclosure provides a backlight module, including a substrate and a reflective layer, a plurality of light emitting units, a plurality of first structures and a plurality of lenses that are located on the substrate, the reflective layer has a plurality of first openings, the first structures have through holes, the light emitting units are located in the first openings and in the through holes, and the lenses are disposed in the first structures far away from one side of the substrate and cover the light emitting sides of the light emitting units.

Optionally, a surface of the first structure on a side away from the substrate is flush with a surface of the light emitting unit on a side away from the substrate.

Optionally, the light emitting surface of the lens has a concave portion.

Optionally, the concave portion is located at the center of the light-emitting surface of the lens.

Optionally, the first structure is located within the first opening.

Optionally, the orthographic projection of the first structure on the substrate covers the orthographic projection of the lens on the substrate.

Optionally, the material of the first structure is white glue.

A second aspect of the present disclosure provides a display device, including a display panel and a backlight module provided in the first aspect of the present disclosure.

A third aspect of the present disclosure provides a method for manufacturing a backlight module, including

Forming a reflective layer having a plurality of first openings on a substrate;

a light emitting unit is arranged in the first opening;

forming a plurality of first structures with through holes, and enabling the light emitting units to be located in the through holes;

and a lens covering the light emitting side of the light emitting unit is arranged on one side of the first structure away from the substrate.

Optionally, the material of the first structures is white glue, and forming the first structures with the through holes includes forming the first structures with the through holes through a printing process.

The beneficial effects of the present disclosure are as follows:

according to the technical scheme, the uniform light effect can be effectively improved on the basis of guaranteeing the waterproof vapor packaging effect of the light-emitting unit, so that the design with larger space between the light-emitting units is possible under the condition that the backlight brightness and the uniform light effect requirements are met, the consumption of the light-emitting units is reduced, and the cost is lowered.

Drawings

The following describes in further detail the specific embodiments of the present disclosure with reference to the drawings.

Fig. 1 is a schematic partial cross-sectional view of a backlight module according to the related art.

Fig. 2 is a schematic partial cross-sectional view of another backlight module according to the related art.

Fig. 3 is a schematic partial cross-sectional view of a backlight module according to an embodiment of the disclosure.

Fig. 4 is a schematic partial top view of the backlight module shown in fig. 3.

Fig. 5 shows another partial top view of the backlight module shown in fig. 3.

Fig. 6 shows a schematic view of a light homogenizing effect of the backlight module shown in fig. 3.

Fig. 7 illustrates a schematic view of a light homogenizing effect of the backlight module shown in fig. 1.

Fig. 8 illustrates a schematic view of a light homogenizing effect of the backlight module shown in fig. 2.

Fig. 9 is another schematic partial cross-sectional view of a backlight module according to an embodiment of the disclosure.

Fig. 10 illustrates an overall cross-sectional view of the backlight module shown in fig. 3.

Detailed Description

As used in this disclosure, "formed on … …," "formed on … …," and "disposed on … …" may mean that one layer is formed directly on or disposed on another layer, or that one layer is formed indirectly on or disposed on another layer, i.e., that other layers are present between the two layers.

It should be noted that although the terms "first," "second," etc. may be used herein to describe various elements, components, elements, regions, layers and/or sections, these elements, components, elements, regions, layers and/or sections should not be limited by these terms. Rather, these terms are used to distinguish one component, member, element, region, layer and/or section from another. Thus, for example, a first component, a first member, a first element, a first region, a first layer, and/or a first portion discussed below may be referred to as a second component, a second member, a second element, a second region, a second layer, and/or a second portion without departing from the teachings of the present disclosure.

In this disclosure, unless otherwise indicated, the term "co-layer disposed" is used to mean that two layers, components, members, elements, or portions may be formed by the same manufacturing process (e.g., patterning process, etc.), and that the two layers, components, members, elements, or portions are generally formed of the same material. For example, the two or more functional layers are arranged in the same layer, meaning that the functional layers arranged in the same layer may be formed using the same material layer and the same manufacturing process, so that the manufacturing process of the display substrate may be simplified.

In the present disclosure, unless otherwise indicated, the expression "patterning process" generally includes the steps of coating of photoresist, exposure, development, etching, stripping of photoresist, and the like. The expression "one patterning process" means a process of forming a patterned layer, feature, component, etc. using a single mask.

The COB backlight module generally adopts hemispherical protection glue to perform vapor-proof encapsulation on a light-emitting unit such as an LED, and the light intensity directly above the light-emitting unit and the light intensity at the periphery are weak, so that the problem of poor light uniformity exists. If the number of light emitting units such as LEDs is increased and the pitch of the light emitting units is reduced, although the uniform light effect can be improved, the product cost including the BOM cost (consumable cost) of the light emitting units is increased and the power consumption of the backlight module is increased.

In the related art, two solutions are proposed for the problem of poor light uniformity of the COB backlight module. The solution is to design the top of the hemispherical protection glue to have a concave portion, for example, as shown in fig. 1, the backlight module of the solution includes a substrate 101, a reflective layer 102 located on the substrate 101, a plurality of light emitting units 103 such as LEDs, and a plurality of hemispherical protection glue 104 with concave portions at the top, where the reflective layer 102 has a plurality of first openings, the light emitting units 103 are located in the first openings, and the hemispherical protection glue 104 with concave portions at the top covers (covers) the light emitting units 103 to perform moisture-proof packaging on the light emitting units 103, so that the light emitting angle of the light emitting units 103 can be increased by the concave design of the top of the hemispherical protection glue 104, and the uniform light effect is improved, however, due to the influence of the dispensing process, the hemispherical protection glue 104 with concave portions at the top manufactured by the dispensing method has the problem that the shape uniformity (or shape stability) is poor, and the shape uniformity of the hemispherical protection glue 104 with concave portions at the top corresponding to each light emitting unit 103 cannot be realized, resulting in uneven uniform light effect at each position of the backlight module. Another solution is a hemispherical protection glue combined lens, for example, as shown in fig. 2, the backlight module of this solution includes a substrate 201, a reflective layer 202 located on the substrate 201, a plurality of light emitting units 203 such as LEDs, a plurality of hemispherical protection glue 204 and a plurality of lenses 205, where the reflective layer 202 has a plurality of first openings, the light emitting units 203 are located in the first openings, the hemispherical protection glue 204 covers (covers) the light emitting units 203 to perform moisture-proof packaging, the lens 205 formed by injection Molding (Molding) covers (covers) the hemispherical protection glue 204 to increase the light emitting angle of the light emitting units 103, and the light-homogenizing effect is improved, but the problem that the uniformity (or the shape stability) of the shape of the hemispherical protection glue 204 manufactured by dispensing is poor is still existed, in addition, the improvement of the light-homogenizing effect by the hemispherical protection glue 204 is a detrimental factor, and the light-homogenizing effect is influenced by the shape of the hemispherical protection glue 204 and the lens 205. It can be seen that both the above solutions in the related art have limited improvement of the dodging effect, and it is difficult to reach higher standards.

In view of the foregoing, an embodiment of the disclosure provides a backlight module, for example, as shown in fig. 3, including a substrate 301, a reflective layer 302 disposed on the substrate 301, a plurality of light emitting units 303, a plurality of first structures 304, and a plurality of lenses 305, wherein the reflective layer 301 has a plurality of first openings, the first structures 304 have through holes, the light emitting units 303 are disposed in the first openings and in the through holes, and the lenses 305 are disposed on a side of the first structures 304 away from the substrate 301 and cover a light emitting side of the light emitting units 303.

According to the backlight module provided by the embodiment, the side surface of the light-emitting unit 303 is subjected to the vapor-proof packaging through the first structure 304, the light side (top surface) of the light-emitting unit 303 is subjected to the vapor-proof packaging through the lens 305, the overall vapor-proof packaging of the light-emitting unit 303 is realized, and the oxidation corrosion risk of the light-emitting unit, which is possibly caused by the fact that the packaging is not tight enough due to the fact that the vapor-proof packaging is carried out only through the lens, is avoided. Furthermore, since the combination of the first structure 304 and the lens 305 realizes a good packaging effect, the embodiment does not need to set a protective adhesive that affects the light-homogenizing effect due to the fact that the morphology cannot be precisely controlled, and adverse effects of the protective adhesive on the light-homogenizing effect are avoided. In summary, the backlight module provided in this embodiment can effectively improve the light-homogenizing effect on the basis of ensuring the waterproof vapor packaging effect of the light-emitting unit 303, so that the design with a larger Pitch (Pitch) of the light-emitting unit 303 is possible under the condition of meeting the backlight brightness and light-homogenizing effect requirements, thereby reducing the usage amount of the light-emitting unit 303 and lowering the cost.

The light emitting unit 303 is, for example, an LED, and further, the LED is, for example, a MiniLED, and the LED may be a blue LED or a white LED. The substrate 301 is internally provided with driving wires, and the driving chip of the backlight module can drive the LEDs after die bonding to emit light through the driving wires.

For example, the first structure 304 having the through-hole may be referred to as a dam, which surrounds the light emitting unit 303. In order to ensure the brightness of the backlight module, the material of the first structure 304 may be a reflective material, and the first structure 304 made of the reflective material may be referred to as a reflective dam.

The lens 305 may be, for example, a dodging lens. The light emitting side of the light emitting unit 303, that is, the side of the light emitting unit 303 away from the substrate 301, for example, as shown in fig. 3, a lens 305, which is, for example, a light uniformizing lens, covers the light emitting side of the light emitting unit 303, that is, covers the light emitting unit 303 to uniformize the light emitted therefrom.

In a possible implementation, for example as shown in fig. 3, a surface of the first structure 304 on a side facing away from the substrate 301 is flush with a surface of the light emitting unit 303 on a side facing away from the substrate 301, i.e. a top surface of the first structure 304 is flush with a top surface of the light emitting unit 303, for example as shown in fig. 3.

Therefore, the side surface of the light-emitting unit 303 can be completely encapsulated through the first structure 304, and the first structure 304 can not cause loss to the light-emitting of the light-emitting unit 303 while playing a role in preventing water vapor encapsulation, so that the light-emitting brightness of the light-emitting unit 303 is ensured, and the backlight brightness and the light-homogenizing effect can be ensured.

In one possible implementation, as shown in fig. 3, the light-emitting surface of the lens 305 has a concave portion.

For example, as shown in fig. 3, the light exit surface (top surface) of the lens 305, which is a light homogenizing lens, is convex as a whole, and the light entrance surface (bottom surface) is concave. For example, the design of the top recess of the lens 305 of the light homogenizing lens can further increase the light emitting angle of the light emitting unit 303 and enhance the light homogenizing effect, so that the distance (Pitch) between the light emitting units 303 can be further increased, the Pitch to OD can reach 4:1, and the usage amount of the light emitting units 303 can be further reduced under the condition that the backlight requirement is met, wherein the OD

The (Optical Distance) is the Distance from the substrate 301 to the upper Optical film.

In one possible implementation, for example, as shown in fig. 3, the concave portion is located at the center of the light-emitting surface of the lens 305.

For example, as shown in fig. 3, the center of the light exit surface of the lens 305, that is, the center of the top surface of the lens 305, adopts a design in which the concave portion is, for example, the center of the light exit surface of the lens 305 of the light equalizing lens, so that the light equalizing effect can be further ensured.

In one possible implementation, such as shown in fig. 3, the front projection of the first structure 304 onto the substrate 301 covers the front projection of the lens 305 onto the substrate 301.

For example, as shown in fig. 3, the diameter of the first structure 304 is larger than that of the lens 305, and the front projection of the first structure 304 on the substrate 301 covers the front projection of the lens 305 on the substrate 301, so that the annular bottom surface of the lens 305 is ensured to be completely attached to the first structure 304, thereby ensuring that the attachment of the lens 305, such as a light homogenizing lens, is smoother, and further ensuring the light homogenizing effect.

Illustratively, in the direction perpendicular to the substrate 301, the shape of the first structure 304 may be formed as desired in a circular shape having a through hole at the center, for example, as shown in fig. 4, or in a square shape having a through hole at the center, for example, as shown in fig. 5, as long as the attachment of the lens 305 on the first structure 304 can be satisfied, it being understood that the shape and size of the through hole are designed according to the shape and size of the light emitting unit 303.

In one possible implementation, the material of the first structure 304 is a reflective material, in particular white glue.

The white glue has high reflectivity and can ensure the brightness of the backlight module, for example, the white glue is silicon white glue. The first structure 304 made of white glue can be prepared by adopting high-precision printing equipment to control the glue amount and overflow phenomenon of the glue through a printing process, so that the size and appearance of the first structure 304 accord with design, for example, the thickness design that the top surface of the first structure 304 is flush with the top surface of the light-emitting unit 303.

In one possible implementation, the material of the reflective layer 302 is white oil.

The white oil has high reflectivity, and can ensure the brightness of the backlight module, for example, the white oil can be resin (such as epoxy resin, polytetrafluoroethylene resin), titanium dioxide (TiO ₂ ) And an organic solvent (e.g., dipropylene glycol methyl ether) or the like, the reflective layer 302 having the first opening, which is white oil, may be formed by an exposure process or a screen printing process.

Fig. 6 shows a schematic view of the light-homogenizing effect of one light-emitting unit 303 of the backlight module provided in this embodiment, fig. 7 shows a schematic view of the light-homogenizing effect of one light-emitting unit 103 of the backlight module with the hemispherical protection glue designed to have a concave portion in the top of the hemispherical protection glue shown in fig. 1, and fig. 8 shows a schematic view of the light-homogenizing effect of one light-emitting unit 203 of the backlight module with the hemispherical protection glue combined lens shown in fig. 2. As can be seen from the comparison between fig. 6, fig. 7 and fig. 8, the backlight module design scheme provided by the embodiment can greatly improve the light homogenizing effect. Furthermore, the backlight module provided in this embodiment can effectively increase the Pitch (Pitch) of the light emitting units 303, and can reach Pitch to OD of 4:1, whereas, for example, the backlight module shown in fig. 1 in which the top of the hemispherical protection glue is designed to have a concave portion and the backlight module shown in fig. 2 in which the hemispherical protection glue is combined with a lens cannot reach Pitch to OD of 4:1, and at most, can only reach Pitch to OD of 3:1.

Referring to table 1, taking a 75inch substrate 301 as an example, when the Pitch to OD ratio is increased from 3:1 to 4:1, the usage of the light emitting units of the LEDs, for example, can be reduced by about 40% in the specifications of OD6 (OD is 6 mm), OD10 (OD is 10 mm), and OD22 (OD is 22 mm), and therefore, the backlight module provided in this embodiment can effectively reduce the usage of the light emitting units 303 of the LEDs, reduce the cost of the backlight module, and save the power consumption of the backlight module.

TABLE 1

In the Pitch column of table 1, 17.93×17.84 is taken as an example, and the Pitch in the X direction and the Pitch in the y direction of the LEDs are 17.93mm and 17.84mm, respectively.

In one possible implementation, unlike that shown in fig. 3, the first structure 904 is located within a first opening of the reflective layer 902, as shown in fig. 9.

Because the flatness of the reflective layer 902, for example, made of white oil, is lower than that of the substrate 301, the first structure 904 provided in this implementation manner is located in the first opening of the reflective layer 902, and the first structure 904 is directly fabricated on the substrate 301 with high flatness, so that the flatness of the first structure 904 can be further ensured, and the lens 305 is more flat and has better light-homogenizing effect. In addition, the material consumption of the reflective layer 902, such as white oil, can be saved, and the cost can be further reduced.

For example, as shown in fig. 9, the first structure 904 is located in the first opening of the reflective layer 902, and there is no overlap between the front projection of the first structure 904 on the substrate 301 and the front projection of the reflective layer 902 on the substrate 301. Further, as shown in fig. 9, the first structure 904 abuts against the side surface of the reflective layer 902, and there is no gap between the two side surfaces, so as to further ensure the brightness of the backlight module and avoid light loss.

In a specific example, the backlight module provided in this embodiment further includes other films, for example, as shown in fig. 10, and in addition to the structure shown in fig. 3, the backlight module provided in this embodiment further includes a supporting layer and an optical film material located on a side of the supporting layer far away from the substrate 301, where the supporting layer includes a plurality of supporting columns (supporters) 1001, the supporting columns 1001 are located in gaps between the light emitting units 303, and the optical film material includes, for example, a diffusion plate 1002, a quantum dot film 1003, a diffusion sheet 1004, and a composite film 1005 that are sequentially stacked in a direction from the substrate 301 to the substrate 301, where OD (Optical Distance) is a distance from the substrate 301 to the diffusion plate 1002.

The first structure 304 and the reflective layer 302 are used for reflecting the light that does not enter the diffusion plate 1002 so as to make the light enter the diffusion plate 1002, so that light loss is avoided and light brightness is ensured. In the optical film material, the diffusion plate 1002 and the diffusion sheet 1004 are mainly used for eliminating a lamp shadow of the light emitted from the light emitting unit 303, improving uniformity of a display screen, the composite film 1005 is mainly used for improving brightness of backlight, and the quantum dot film 1003 is used for converting blue light into white light through blue light excitation when the light emitting unit 303 such as a blue light LED is used. The support column 1001 is used for providing a certain light mixing distance and eliminating a lamp shadow.

Another embodiment of the present disclosure provides a method for manufacturing a backlight module, including

Forming a reflective layer having a plurality of first openings on a substrate;

a light emitting unit is arranged in the first opening;

forming a plurality of first structures with through holes, and enabling the light emitting units to be located in the through holes;

and a lens covering the light emitting side of the light emitting unit is arranged on one side of the first structure away from the substrate.

For example, the first structure may be referred to as a dam, and the plurality of first structures having through holes are formed such that the light emitting units are positioned in the through holes, i.e., the dams surrounding the light emitting units are formed.

In one possible implementation, a side surface of the first structure remote from the substrate is flush with a side surface of the light emitting unit remote from the substrate.

In one possible implementation manner, the light emitting surface of the lens provided in the preparation method provided in this embodiment has a concave portion.

In one possible implementation manner, the lens concave portion provided in the preparation method provided in this embodiment is located at the center of the light-emitting surface of the lens.

In one possible implementation manner, the orthographic projection of the first structure on the substrate provided in the preparation method provided in this embodiment covers the orthographic projection of the lens on the substrate.

In a possible implementation manner, in the manufacturing method provided by this embodiment, the material of the first structure is white glue, and the forming the plurality of first structures with through holes includes forming the plurality of first structures with through holes through a printing process.

The white glue has high reflectivity and can ensure the brightness of the backlight module, for example, the white glue is silicon white glue. The first structure is formed through the printing process, and the control of the glue amount and the overflow phenomenon of the glue by adopting high-precision printing equipment can be realized, so that the size and the appearance of the first structure accord with the design, for example, the thickness design that the top surface of the first structure is flush with the top surface of the light-emitting unit.

In a possible implementation manner, in the preparation method provided by this embodiment, the material of the reflective layer is white oil, and the forming the reflective layer with the plurality of first openings on the substrate includes forming the reflective layer with the first openings on the substrate through an exposure process or a screen printing process.

In one possible implementation manner, in the preparation method provided in this embodiment, the first structure is located in the first opening of the reflective layer when the first structure is formed by sizing the first opening when the reflective layer having the plurality of first openings is formed on the substrate.

Another embodiment of the present disclosure provides a display device, including a display panel and a backlight module provided by the foregoing embodiments.

For example, the display device provided in this embodiment is a liquid crystal display device, and the display panel included in the display device is a liquid crystal display panel. The backlight module is, for example, a direct type backlight module, and light emitted from a light emitting unit of the direct type backlight module is incident to the liquid crystal display panel through the optical film material.

The liquid crystal display panel comprises a color film substrate, an array substrate arranged opposite to the color film substrate, and a liquid crystal layer arranged between the color film substrate and the array substrate. The array substrate and the color film substrate are bonded together through the frame sealing glue, and the liquid crystal layer is formed in a closed area surrounded by the frame sealing glue.

The color film substrate comprises a first substrate, a black matrix layer and a color resistance layer, wherein the black matrix layer and the color resistance layer are formed on the first substrate, the first substrate comprises sub-pixel areas which are arranged in an array, the black matrix layer is provided with a plurality of openings corresponding to the sub-pixel areas, and the color resistance layer comprises a plurality of blue color resistance layers, a plurality of red color resistance layers and a plurality of green color resistance layers which are respectively arranged in the openings.

The Array substrate may also be referred to as an Array substrate or a TFT substrate, and includes a second substrate, a plurality of scan lines (or Gate lines) extending in a first direction (e.g., a row direction) and a plurality of Data lines (Data lines) extending in a second direction (e.g., a column direction) formed on the second substrate. The plurality of scanning lines and the plurality of data lines are intersected to define sub-pixel areas arranged in an array mode, and it is understood that the sub-pixel areas on the array substrate are in one-to-one correspondence with the sub-pixel areas on the color film substrate, and the one-to-one correspondence is understood that orthographic projection of the sub-pixel areas on the array substrate on the second substrate coincides with orthographic projection of the sub-pixel areas on the color film substrate on the second substrate. Each sub-pixel region of the array substrate is provided with a pixel electrode and a Thin Film Transistor (TFT), wherein a gate electrode of the thin film transistor is connected with a scan line, a first electrode (e.g., a source electrode) is connected with a data line, and a second electrode (e.g., a drain electrode) is connected with a pixel electrode belonging to the same sub-pixel region. For example, the array substrate further includes a common electrode, and a first insulating layer between the data line and the common electrode and a second insulating layer between the common electrode and the pixel electrode. For example, the pixel electrode and the common electrode are Indium Tin Oxide (ITO) electrodes or Indium Zinc Oxide (IZO) electrodes, respectively.

The liquid crystal molecules of the liquid crystal layer are twisted under the action of a driving electric field formed between the pixel electrode and the common electrode to control the polarization direction of incident light, and the transmittance of the incident light is controlled under the cooperation of two polarizers respectively arranged at the light inlet side and the light outlet side of the liquid crystal display panel, so that color display is realized by combining the color resistance layer.

The display device provided in this embodiment may be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, and a navigator, which is not limited in this embodiment.

It should be apparent that the foregoing examples of the present disclosure are merely illustrative of the present disclosure and not limiting of the embodiments of the present disclosure, and that various other changes and modifications may be made by one of ordinary skill in the art based on the foregoing description, and it is not intended to be exhaustive of all embodiments, and all obvious changes and modifications that come within the scope of the present disclosure are intended to be embraced by the technical solution of the present disclosure.

Claims (10)

1. The backlight module is characterized by comprising a substrate, a reflecting layer, a plurality of light-emitting units, a plurality of first structures and a plurality of lenses, wherein the reflecting layer is arranged on the substrate, the reflecting layer is provided with a plurality of first openings, the first structures are provided with through holes, the light-emitting units are arranged in the first openings and are positioned in the through holes, and the lenses are arranged on one side, far away from the substrate, of the first structures and cover the light-emitting sides of the light-emitting units.

2. A backlight module according to claim 1, wherein a side surface of the first structure remote from the substrate is flush with a side surface of the light emitting unit remote from the substrate.

3. The backlight module according to claim 1, wherein the light-emitting surface of the lens has a concave portion.

4. A backlight module according to claim 3, wherein the recess is located at the center of the light-emitting surface of the lens.

5. A backlight module according to claim 1, wherein the first structure is located in the first opening.

6. A backlight module according to claim 5, wherein the orthographic projection of the first structure on the substrate covers the orthographic projection of the lens on the substrate.

7. A backlight module according to claim 1, wherein the material of the first structure is white glue.

8. A display device comprising a display panel and a backlight module according to any one of claims 1-7.

9. A preparation method of a backlight module is characterized by comprising the following steps of

Forming a reflective layer having a plurality of first openings on a substrate;

a light emitting unit is arranged in the first opening;

forming a plurality of first structures with through holes, and enabling the light emitting units to be located in the through holes;

and a lens covering the light emitting side of the light emitting unit is arranged on one side of the first structure away from the substrate.

10. The method of manufacturing according to claim 9, wherein the material of the first structures is white glue, and the forming the plurality of first structures having the through holes includes forming the plurality of first structures having the through holes by a printing process.