CN109459886B

CN109459886B - Backlight module, manufacturing method and display device

Info

Publication number: CN109459886B
Application number: CN201811289396.0A
Authority: CN
Inventors: 林宗伟
Original assignee: Xiamen Tianma Microelectronics Co Ltd
Current assignee: Xiamen Tianma Microelectronics Co Ltd
Priority date: 2018-10-31
Filing date: 2018-10-31
Publication date: 2021-11-02
Anticipated expiration: 2038-10-31
Also published as: CN109459886A

Abstract

The invention relates to the technical field of display, and discloses a backlight module, a manufacturing method and a display device, which are used for improving the brightness of gaps among LED devices of a Mini LED surface light source, further improving the starry problem of the Mini LED surface light source and improving the display effect, wherein the backlight module comprises: the LED display device comprises a substrate and a plurality of LED devices arranged on one side of the substrate, wherein the LED devices are arranged in a matrix; the packaging glue is used for carrying out multi-surface packaging on the plurality of LED devices; the fluorescent layer is positioned on one side, far away from the substrate, of the packaging adhesive; wherein the refractive index of the fluorescent layer is smaller than that of the packaging adhesive.

Description

Backlight module, manufacturing method and display device

Technical Field

The invention relates to the technical field of display, in particular to a backlight module, a manufacturing method and a display device.

Background

The Mini LED is a new branch of the display screen, and the display screen with 0.5-1.2 mm pixel particles can be realized through tens of micron-sized LED crystals. Mini LED adopts the straight following formula to give out light, considers cost and the problem of beating, and the chip quantity is better less more, and this just leads to necessarily having great gap between the chip, and gap between the chip is because there is not luminous body, and the light intensity is more weak, can present the dark space, and the positive light intensity of chip is stronger simultaneously, is the bright space to lead to the actual display effect of Mini LED area light source to have bright and dark alternate sky problem, influence display effect.

Disclosure of Invention

The embodiment of the invention provides a backlight module, a manufacturing method and a display device, which are used for improving the brightness of gaps among LED devices of a Mini LED surface light source, further improving the starry problem of the Mini LED surface light source and improving the display effect.

In one aspect, an embodiment of the present invention provides a backlight module, including:

the LED display device comprises a substrate and a plurality of LED devices arranged on one side of the substrate, wherein the LED devices are arranged in a matrix;

the packaging glue is used for carrying out multi-surface packaging on the plurality of LED devices;

the fluorescent layer is positioned on one side, far away from the substrate, of the packaging adhesive;

wherein the refractive index of the fluorescent layer is smaller than that of the packaging adhesive.

Optionally, a transparent adhesive layer is filled between the packaging adhesive and the fluorescent layer; the refractive index of the transparent adhesive layer is smaller than that of the packaging adhesive, and the refractive index of the transparent adhesive layer is larger than that of the fluorescent layer.

Optionally, a light mixing distance between adjacent LED devices in the plurality of LED devices is less than or equal to a sum of the thickness of the fluorescent layer and the thickness of the transparent adhesive layer.

Optionally, a light mixing distance between the adjacent LED devices is H, a distance between the packaged adjacent LED devices along the direction in which the LED devices are arranged on the substrate is L, and a maximum light emitting angle of each LED device is Φ, which satisfies a condition of tan (90 ° - Φ/2)) -2H/L.

Optionally, diffusion particles are added in the fluorescent layer and/or the transparent adhesive layer.

Optionally, the diffusion particles are titanium dioxide or silicon dioxide.

Optionally, the fluorescent layer includes a transparent adhesive and a fluorescent material doped in the transparent adhesive.

Optionally, the refractive index of the packaging adhesive is 1-1.8.

Optionally, the refractive index of the transparent adhesive layer is 1-1.8.

Optionally, the refractive index of the fluorescent layer is 1-1.8.

In a second aspect, an embodiment of the present invention provides a display device, including the backlight module according to the first aspect.

In a third aspect, an embodiment of the present invention provides a method for manufacturing a backlight module, including:

the method comprises the following steps of (1) printing a plurality of LED devices on a substrate with wiring completed, and enabling the LED devices to be arranged in a matrix;

packaging a plurality of surfaces, which are not contacted with the substrate, of the plurality of LED devices by using glue by adopting a chip packaging process to form packaging glue;

and a fluorescent layer is formed on one side of the packaging adhesive, which is far away from the substrate, wherein the refractive index of the fluorescent layer is smaller than that of the packaging adhesive.

In the embodiment of the invention, the backlight module comprises a substrate and a plurality of LED devices arranged on one side of the substrate, wherein the LED devices are arranged in a matrix; this backlight unit carries out the multiaspect encapsulation to a plurality of LED devices through the encapsulation glue, then glues the one side of keeping away from the base plate with the fluorescent layer setting at the encapsulation to the refracting index through setting up the fluorescent layer is less than the refracting index that the encapsulation was glued, increases the luminous angle of LED device, thereby has promoted the luminance in space between the LED device, and then has improved the starry sky problem of Mini LED area source, and has promoted the display effect of Mini LED.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention.

FIG. 1 is a front view of a Mini LED direct type lighting in the prior art;

FIG. 2 is a side view of a Mini LED direct type lighting in the prior art;

fig. 3 is a schematic view of a backlight module according to an embodiment of the invention;

FIG. 4 is a schematic diagram of a birefringent structure provided by an embodiment of the present invention;

FIG. 5 is a schematic view of another backlight module according to an embodiment of the present invention;

FIG. 6 is a schematic view of another refractive structure provided in accordance with an embodiment of the present invention;

fig. 7 is a schematic diagram of a light mixing distance in the backlight module according to the embodiment of the invention;

FIG. 8 is a schematic view of another backlight module according to an embodiment of the present invention;

FIG. 9 is a flowchart of a method for manufacturing a backlight module according to an embodiment of the invention;

fig. 10 is a schematic view of a display device according to an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the technical solutions of the present invention. All other embodiments obtained by a person skilled in the art without any inventive work based on the embodiments described in the present application are within the scope of the protection of the technical solution of the present invention.

In the prior art, when the Mini LED adopts direct illumination as shown in fig. 1 and 2, the chip, i.e., the chip in fig. 1 and 2, has strong front light intensity and is an obvious bright area, and the gap between the chips has no illuminant and has weak light intensity and is an obvious dark area, so that the problem of starry sky with alternate bright and dark light exists in the actual display effect of the Mini LED area light source, and the display effect is affected.

Therefore, the invention provides a backlight module which comprises a substrate and a plurality of LED devices arranged on one side of the substrate, wherein the LED devices are arranged in a matrix; this backlight unit carries out the multiaspect encapsulation to a plurality of LED devices through the encapsulation glue, then glues the one side of keeping away from the base plate with the fluorescent layer setting at the encapsulation to the refracting index through setting up the fluorescent layer is less than the refracting index that the encapsulation was glued, increases the luminous angle of LED device, thereby has promoted the luminance in space between the LED device, and then has improved the starry sky problem of Mini LED area source, and has promoted the display effect of Mini LED.

The backlight module provided by the embodiment of the invention is further described with reference to the accompanying drawings.

As shown in fig. 3, the backlight module provided in the embodiment of the present invention includes a substrate 30 and a plurality of LED devices 31 disposed on one side of the substrate 30, where the plurality of LED devices 31 are arranged in a matrix, and it should be noted that, in practical applications, the specific number of the LED devices 31 may be flexibly selected according to practical needs without limitation.

In the embodiment of the present invention, the LED device 31 may be a Mini LED device, where the Mini LED refers to a light emitting diode that uses tens of micron-sized LED crystals and can realize a display screen with 0.5-1.2 mm pixel particles; the LED device 31 may be other types of LED devices having a starry problem, such as a small pitch LED, a Micro LED, and the like, and in the embodiment of the present invention, the LED device 31 is specifically taken as a Mini LED device as an example to further describe the backlight module in the embodiment of the present invention.

The backlight module of the embodiment of the present invention further includes a packaging adhesive 32 for performing multi-surface packaging on the plurality of LED devices 31 disposed on the substrate 30, wherein the packaging adhesive 32 can select a packaging adhesive with high light transmittance and high refractive index, so as to increase the luminous flux of the LED devices 31, such as a silicon gel.

In practical applications, the LED device 31 generally includes six surfaces, and the LED device 31 is disposed on one side of the substrate 30 through one surface, so that the other five surfaces of the LED device 31 can be encapsulated by the encapsulation glue 32, so that light emitted by the LED device 31 can be further scattered when passing through the encapsulation glue 32 with high light transmittance and high refractive index, in the embodiment of the present invention, the other four surfaces, or three surfaces, or two surfaces of the LED device 31 can also be encapsulated by the encapsulation glue 32, and of course, all six surfaces of the LED device 31 can also be encapsulated by the encapsulation glue 32. In the embodiment of the present invention, in order to furthest increase the light emitting angle of the LED device 31, for example, the other five surfaces of each of the LED devices 31 are simultaneously packaged by using the packaging adhesive 32, so that light emitted from each of the LED devices 31 can be further scattered when passing through the packaging adhesive 32 with high light transmittance and high refractive index.

Alternatively, in the embodiment of the present invention, for convenience of description, n1 is used to represent the refractive index of the encapsulant 32, where the refractive index refers to the ratio of the propagation speed of light in vacuum to the propagation speed of light in a medium, and then the refractive index n1 of the encapsulant 32 may range from 1 to 1.8, for example, the refractive index n1 may be set to 1, may be set to a value of 1.45, may also be set to 1.8, and so on.

In the embodiment of the present invention, the backlight module further includes a fluorescent layer 33, as shown in fig. 3, the fluorescent layer 33 is located on a side of the package adhesive 32 away from the substrate 30, and for convenience of description, n3 is used to indicate a refractive index of the fluorescent layer 33, in order to further increase a light emitting angle of the LED device 31, a refractive index n3 of the fluorescent layer 33 is smaller than a refractive index n1 of the package adhesive 32, so that a birefringent structure as shown in fig. 4 can be formed.

In fig. 4, the dotted line indicates a normal line, an angle formed by the light emitted from the LED device 31 and the normal line after passing through the encapsulant 32 having high light transmittance and high refractive index n1 is a in fig. 4, when the light emitted from the LED device 31 is further scattered from the encapsulant 32 having high refractive index n1 to the fluorescent layer 33 having a refractive index lower than the refractive index n1 of the encapsulant 32, an angle formed by the light emitted from the LED device 31 and the normal line is b in fig. 4, since the refractive index n3 of the fluorescent layer 33 is smaller than the refractive index n1 of the encapsulant 32, that is, the light emitted from the LED device 31 passes through the birefringent structure in which the refractive index decreases in order, the light emission angle of the light emitted from the LED device 31 can be increased from the birefringent structure shown in fig. 4 by the light from the optically dense medium to the optically sparse medium, and thus the brightness of the gap between the adjacent LED devices 31 is improved, thereby improving the problem of starry sky and improving the display effect.

Alternatively, in the embodiment of the present invention, the value of the refractive index n3 of the fluorescent layer 33 is in a range of 1 to 1.8, for example, n3 may be set to 1, set to 1.3, set to 1.5, or set to 1.8, etc., but the refractive index n3 of the fluorescent layer 33 satisfies the condition that the refractive index of the fluorescent layer 33 is smaller than the refractive index n1 of the encapsulant 32, for example, when the refractive index n1 of the encapsulant 32 is set to 1.45, the refractive index n3 of the fluorescent layer 33 may be set to 1, and may also be set to 1.2, etc., which is smaller than 1.45 and is greater than or equal to 1.

Alternatively, in the embodiment of the present invention, the fluorescent layer 33 includes a transparent adhesive and a fluorescent material doped in the transparent adhesive, such as a fluorescent powder, wherein the transparent adhesive may be an adhesive with high light transmittance, and in practical applications, the fluorescent layer 33 may also be called a fluorescent film or a fluorescent film layer.

Alternatively, in the embodiment of the present invention, as shown in fig. 5, the backlight module in the embodiment of the present invention may further include a transparent adhesive layer 34, where the transparent adhesive layer 34 is filled between the encapsulation adhesive 32 and the fluorescent layer 33, a refractive index of the transparent adhesive layer 34 is smaller than a refractive index of the encapsulation adhesive 32, and the refractive index of the transparent adhesive layer 34 is greater than the refractive index of the fluorescent layer 33, in fig. 5, n1 represents the refractive index of the encapsulation adhesive 32, n2 represents the refractive index of the transparent adhesive layer 34, and n3 represents the refractive index of the fluorescent layer 33, so that the refractive indexes of the encapsulation adhesive 32, the transparent adhesive layer 34, and the fluorescent layer 33 in the backlight module satisfy a condition that n1> n2> n3, that is, the refractive indexes of the encapsulation adhesive 32, the transparent adhesive layer 34, and the fluorescent layer 33 are sequentially decreased.

As shown in fig. 6, which is a schematic view of an emitting structure formed when refractive indexes of the encapsulant 32, the transparent adhesive layer 34 and the fluorescent layer 33 in the backlight module satisfy the condition of n1> n2> n3, in fig. 6, an angle c represents an angle formed by the LED device 31 after passing through the encapsulant 32 and a normal line, an angle d represents an angle formed by the LED device 31 after passing through the encapsulant 32 and a normal line, and an angle e represents an angle formed by the LED device 34 after passing through the fluorescent layer 33 and a normal line, because the refractive index n1 of the encapsulant 32 is greater than the refractive index n2 of the transparent adhesive layer 34, that is, the LED device 31 emits light from the optically dense medium to the optically sparse medium, the angle d is greater than the angle c, so that the light emitting angle is increased, further, the refractive index n2 of the transparent adhesive layer 34 is greater than the refractive index n3 of the fluorescent layer 33, and the light further propagates from the optically dense medium to the optically sparse medium, the angle e is larger than the angle d, so that the light emitting angle of light is further increased, and thus, the light emitting structure in fig. 6 can further increase the light emitting angle of light, so that the light emitting angle of the LED device 31 can be further increased, and the brightness of the gaps between the LED devices 31 can be further improved, thereby further improving the problem of starry sky and improving the display effect.

Alternatively, in the embodiment of the present invention, the refractive index n2 of the transparent adhesive layer 34 is in a range of 1 to 1.8, for example, the refractive index n2 of the transparent adhesive layer 34 may be set to 1, or set to 1.3, or set to 1.4, set to 1.5, or set to 1.8, and the like, and the refractive index of the selected transparent adhesive layer 34 satisfies the conditions of being smaller than the refractive index of the encapsulation adhesive 32 and being larger than the refractive index of the fluorescent layer 33.

In an optional manner, in the embodiment of the invention, in order to further reduce the problem of starry sky of the Mini LED area light source, a light mixing distance between adjacent LED devices in a plurality of LED devices in the backlight module may be set to be less than or equal to the sum of the thickness of the fluorescent layer and the thickness of the transparent adhesive layer, therefore, the intersection point of the light rays corresponding to the maximum light-emitting angle emitted by the adjacent LED devices falls into the position of the fluorescent layer or the transparent adhesive layer, namely, the light emitted by the adjacent LED devices can illuminate the gap between the adjacent LED devices in the substrate, thereby eliminating the dark area, therefore, the problem of starry sky of the Mini LED surface light source can be reduced, the display effect of the Mini LED surface light source is further improved, and the light mixing distance between the adjacent LED devices in the plurality of LED devices in the backlight module is smaller than or equal to the sum of the thickness of the fluorescent layer and the thickness of the transparent adhesive layer.

The light mixing distance refers to a vertical distance from an intersection point of light rays corresponding to the maximum light emitting angle of the adjacent LED devices to the light emitting upper surface of the adjacent LED devices after packaging, wherein the light emitting upper surface of the LED devices after packaging refers to a surface which is far away from the substrate and deviates from the surface of the LED devices arranged on one side of the substrate.

For example, as shown in fig. 7, a light ray 1 is a light ray corresponding to the maximum light emitting angle of one of the adjacent LED devices, a light ray 2 is a light ray corresponding to the maximum light emitting angle of the other of the adjacent LED devices, an intersection point where the light ray 1 intersects with the light ray 2 is an intersection point 1 in fig. 7, L in fig. 7 represents a distance between the packaged adjacent LED devices in the arrangement direction of the LED devices on the substrate, and H in fig. 7 represents a light mixing distance between the adjacent LED devices, so that the light mixing distance H is a vertical distance from the intersection point 1 to L, that is, a vertical distance from the intersection point of the light ray corresponding to the maximum light emitting angle of the adjacent LED device to the light emitting upper surface of the packaged adjacent LED device.

In fig. 7, t represents the sum of the thickness of the fluorescent layer and the thickness of the transparent adhesive layer, so in the embodiment of the present invention, H may be set to be smaller than t or equal to t, for example, the light mixing distance H shown in fig. 7 is equal to the sum t of the thickness of the fluorescent layer and the thickness of the transparent adhesive layer, so that the intersection point of the light corresponding to the maximum light emitting angle of the adjacent LED device falls into the position of the fluorescent layer or the transparent adhesive layer, that is, the light emitted by the adjacent LED device can illuminate the gap between the adjacent LED devices in the substrate, thereby eliminating the dark region, so that the problem of starry sky of the Mini LED surface light source can be reduced, and the display effect of the Mini LED surface light source can be further improved.

As shown in fig. 7, L is used to represent the distance between the adjacent packaged LED devices along the arrangement direction of the LED devices on the substrate, the maximum light emitting angle of each LED device is assumed to be Φ, and H is the light mixing distance, i.e. the vertical distance from the intersection of the light rays corresponding to the maximum light emitting angle of the adjacent LED devices to the light emitting upper surface of the adjacent packaged LED devices, then, in the inventive embodiment, the distance L between the maximum light emitting angle of the LED devices and the adjacent packaged LED devices along the arrangement direction of the LED devices on the substrate, the intersection of the light rays corresponding to the maximum light emitting angle of the adjacent LED devices, and the vertical distance H from the intersection of the light rays corresponding to the light emitting upper surface of the adjacent packaged LED devices, i.e. the light mixing distance, satisfy the condition of tan (90 ° -2) 2H/L, thereby further increasing the maximum light emitting angle of the LED devices, and further improving the problem of the small Mini LED area light source, and the display effect of the Mini LED surface light source is improved.

Alternatively, in the embodiment of the present invention, as described above, when the light mixing distance between adjacent LED devices in the plurality of LED devices in the backlight module is set to be less than or equal to the sum of the thickness of the fluorescent layer and the thickness of the transparent adhesive layer, the light emitted by the adjacent LED devices can illuminate the gap between the adjacent LED devices in the substrate, so as to eliminate the dark region.

For example, as shown in fig. 8, n1 represents the refractive index of the encapsulation adhesive, n2 represents the refractive index of the transparent adhesive layer, n3 represents the refractive index of the fluorescent layer, Φ represents the maximum light-emitting angle of the LED device, β represents the angle between the light corresponding to the maximum light-emitting angle of the LED device and the distance L between the adjacent LED devices after encapsulation along the arrangement direction of the LED devices on the substrate, H represents the light mixing distance, and t represents the sum of the thickness of the fluorescent layer and the thickness of the transparent adhesive layer, then, when the light mixing distance between the adjacent LED devices in the plurality of LED devices in the backlight module is equal to the sum of the thickness of the fluorescent layer and the thickness of the transparent adhesive layer, the above parameters satisfy the following formula (1):

then, the following formula (2) can be derived from formula (1):

H＝(L/2)·[√[1-(cosβ)^2]/cosβ]

(L/2) · √ {1- [ n1/n2 · sin (φ/2) ] ^2}/[ n1/n2 · sin (φ/2) ] (equation 2)

Then, the formula (2) pushes to the formula (3):

n2/n1＝√{sin(φ/2)^2+[H/(L/2)·sin(φ/2)]^2}

sin (phi/2) · V [1+ (H (L/2)) ^2] (equation 3)

That is, when H is equal to t, as shown in formula (3), n2/n1 ═ sin (Φ/2) · v [1+ (t/(L/2)) ^2], indicating that the light mixing distance H between adjacent LED devices in the plurality of LED devices in the backlight module is equal to the sum t of the thickness of the fluorescent layer and the thickness of the transparent adhesive layer, in the embodiment of the present invention, the light mixing distance H between adjacent LED devices in the plurality of LED devices in the backlight module may be equal to less than the sum t of the thickness of the fluorescent layer and the thickness of the transparent adhesive layer, and therefore, the formula (3) can be deduced to formula (4):

n2/n1≤sin(φ/2)·√[1+(t/(g/2))^2](4)

formula (4) represents that the light mixing distance H between adjacent LED devices in the plurality of LED devices in the backlight module is less than or equal to the sum t of the thickness of the fluorescent layer and the thickness of the transparent adhesive layer, wherein fig. 8 is a schematic diagram that the light mixing distance H in the backlight module is less than the sum t of the thickness of the fluorescent layer and the thickness of the transparent adhesive layer.

When t is 0.15mm, L is 1.3mm, and phi is 120 degrees, the value n2/n1 of the ratio of the refractive index n1 of the packaging adhesive to the refractive index n2 of the transparent adhesive layer can be obtained by the formula (4) and is less than or equal to 0.955, therefore, when the refractive index of the packaging adhesive is set to satisfy that n1 is more than n2 to form a double-folding layer, the light-emitting angle is enlarged, n2/n1 can be set to be less than or equal to 0.955, so that light emitted by adjacent LED devices can illuminate gaps between adjacent LED devices in the substrate, and further eliminate dark regions, and then based on that n1 is more than n2 and n2/n1 is less than or equal to 0.955, the refractive index n3 of the fluorescent layer less than n2 is set, so that the light-emitting angle of the LED devices can be further increased, and the gaps between adjacent LED devices can be eliminated, and further eliminate the dark regions, thereby further solving the problem of starry sky and improving the display effect.

Alternatively, in the embodiment of the present invention, in order to further increase the light emitting angle of the LED device 31, diffusion particles may be added to the fluorescent layer in the backlight module, or diffusion particles may be added to the transparent adhesive layer, or diffusion particles may be added to both the fluorescent layer and the transparent adhesive layer in the backlight module, where the added diffusion particles may be titanium dioxide, or silicon dioxide.

The diffusion particles added in the fluorescent layer or/and the transparent adhesive layer can further increase the scattering of light transmitted to the fluorescent layer or/and the transparent adhesive layer, and further increase the light emitting angle of the LED devices 31, so that the brightness of gaps among the LED devices 31 can be further improved, the starry sky problem can be further improved, and the display effect can be improved.

Based on the same inventive concept, an embodiment of the present invention further provides a method for manufacturing a backlight module, as shown in fig. 9, including:

step 101: the method comprises the following steps of (1) printing a plurality of LED devices on a substrate with wiring completed, and enabling the plurality of LED devices to be arranged in a matrix;

step 102: packaging a plurality of surfaces, which are not contacted with the substrate, of the plurality of LED devices by using glue by adopting a chip packaging process to form packaging glue;

step 103: and a fluorescent layer is formed on one side of the packaging adhesive, which is far away from the substrate, wherein the refractive index of the fluorescent layer is smaller than that of the packaging adhesive.

In the embodiment of the present invention, a plurality of LED devices may be mounted on a substrate with a finished wiring, that is, a die bonding operation is performed, so that the plurality of LED devices are arranged in a matrix on the substrate, and then a Chip packaging process is used to Package a plurality of surfaces of the plurality of LED devices that are not in contact with the substrate with glue to form a packaging glue, wherein the Chip packaging process may specifically be a CSP (Chip Scale Package) process or other Chip packaging processes.

Or the other five surfaces of the plurality of LED devices except the surface used for printing the parts on the wiring-finished substrate can be firstly sealed by a chip packaging process such as a CSP process and glue packaging, namely CSP packaging, so that packaging glue is formed on the five surfaces, then the plurality of LED devices after sealing glue are fixedly crystallized on the substrate, and a fluorescent layer is formed on one side of the packaging glue, which is far away from the substrate, or all the LED surfaces are filled with transparent glue by processes such as injection molding, film pressing, spraying and the like to form a transparent glue layer, namely sealing glue, after the plurality of LED devices after sealing glue are fixedly crystallized on the substrate, and finally the fluorescent layer is finished by processes such as injection molding, film pressing, spraying and the like or a separated fluorescent film is directly arranged on the mini LED surface.

Based on the same inventive concept, an embodiment of the present invention provides a display apparatus, which includes a backlight module provided in an embodiment of the present invention, and the display apparatus may be a display apparatus such as a liquid crystal panel, a liquid crystal display, a liquid crystal television, or a mobile device such as a mobile phone, a tablet computer, a notebook, a smart watch, a smart bracelet, a VR/AR glasses, as shown in fig. 10, which is a top view of the mobile phone provided in the embodiment of the present invention, wherein the display screen includes the backlight module in the embodiment of the present invention, the backlight module includes a substrate and a plurality of LED devices disposed on one side of the substrate, the plurality of LED devices are arranged in a matrix, the plurality of LED devices are multi-surface encapsulated by an encapsulation adhesive, and the fluorescent layer is disposed on a side of the encapsulation adhesive away from the substrate, wherein a refractive index of the fluorescent layer is smaller than a refractive index of the encapsulation adhesive, so that, the luminous angle of the LED device can be increased, the brightness of gaps among the LED devices is improved, and therefore the problem of starry sky is improved, and the display effect of the display screen is improved. Since the display device provided by this embodiment includes the backlight module described in the above embodiments, the display device also has the advantages associated with the backlight module, and the implementation of the display device can refer to the above embodiments of the backlight module, and repeated details are omitted.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

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.

Claims

1. A backlight module is characterized in that the backlight module comprises:

the packaging glue is used for carrying out multi-surface packaging on the plurality of LED devices, wherein the packaging glue is formed by adopting a chip packaging process and using glue for sealing;

2. The backlight module as claimed in claim 1, wherein a transparent adhesive layer is filled between the encapsulation adhesive and the phosphor layer; the refractive index of the transparent adhesive layer is smaller than that of the packaging adhesive, and the refractive index of the transparent adhesive layer is larger than that of the fluorescent layer.

3. The backlight module as claimed in claim 2, wherein a light mixing distance between adjacent ones of the plurality of LED devices is less than or equal to a sum of a thickness of the fluorescent layer and a thickness of the transparent adhesive layer.

4. The backlight module of claim 3, wherein: the light mixing distance between the adjacent LED devices is H, the distance between the adjacent LED devices after packaging along the arrangement direction of the LED devices on the substrate is L, and the maximum light-emitting angle of each LED device is phi, so that the condition that tan (90-phi/2) is 2H/L is met.

5. The backlight module as claimed in any one of claims 2 to 4, wherein diffusion particles are added in the fluorescent layer and/or the transparent adhesive layer.

6. The backlight module of claim 5, wherein the diffusing particles are titanium dioxide or silicon dioxide.

7. The backlight module as claimed in claim 2, wherein the phosphor layer comprises a transparent adhesive and a phosphor material doped in the transparent adhesive.

8. The backlight module as claimed in claim 1, wherein the refractive index of the encapsulant is 1-1.8.

9. The backlight module as claimed in claim 2, wherein the refractive index of the transparent adhesive layer is 1 to 1.8.

10. The backlight module as claimed in claim 1, wherein the refractive index of the phosphor layer is 1 to 1.8.

11. A display device comprising a backlight module according to any one of claims 1-10.

12. A method for manufacturing a backlight module is characterized by comprising the following steps: