CN110265387B

CN110265387B - LED packaging structure, backlight module and display device

Info

Publication number: CN110265387B
Application number: CN201910527349.3A
Authority: CN
Inventors: 韩继远; 孟长军
Original assignee: SKYWORTH OPTICAL-ELECTRONIC CO LTD
Current assignee: SKYWORTH OPTICAL-ELECTRONIC CO LTD
Priority date: 2019-06-18
Filing date: 2019-06-18
Publication date: 2021-05-07
Anticipated expiration: 2039-06-18
Also published as: CN110265387A

Abstract

The invention discloses an LED packaging structure, a backlight module and display equipment, and relates to the technical field of display equipment. The LED packaging structure comprises a support, a chip set and a reflecting layer, wherein a packaging groove is formed in the support; the chip group is arranged in the packaging groove, the chip group comprises a first chip positioned in the center of the packaging groove, and a second chip and a third chip are arranged around the first chip; the reflecting layer is arranged above the first chip. Among this LED packaging structure, be provided with three kinds of chips, wherein first chip can be for sending the blue light, wherein, red light and green glow can be sent respectively to second chip and third chip, second chip and third chip distribution are in the periphery of first chip, the blue light that first chip sent is to diffusion all around under the effect of reflector layer to mix with ruddiness and green glow and form white light, be favorable to improving the homogeneity that the tricolor mixes, avoid the color cast problem, improve display effect.

Description

LED packaging structure, backlight module and display device

Technical Field

The invention relates to the technical field of display equipment, in particular to an LED packaging structure, a backlight module and display equipment.

Background

Currently, in the field of flat panel display, liquid crystal televisions have become mainstream, and the proportion of the liquid crystal television including the LED backlight is increasing. The LED backlight has many advantages, such as no toxic mercury, environmental protection, excellent color gamut display, and good mechanical shock stability. With the improvement of living standard, people pay more and more attention to the performance of television colors, and color regression becomes a main task of display, so that wide-color-gamut televisions come into the sight of people.

At present, liquid crystal display technologies capable of realizing 100% NTSC color gamut coverage include a quantum dot scheme, an RGB three-color chip LED scheme, and a scheme in which a KSF phosphor is matched with a color film to thicken a panel, wherein the quantum dot technology is subject to stability and yield of materials, resulting in high cost and poor product reliability; the KSF phosphor technology can only be used with individual color film panel products to achieve 100% NTSC display effect, and has great limitations. In the early years, the production yield of red and green chips is low, the luminous efficiency is low, the RGB three-color chip technology is not widely applied to the backlight module all the time, and the RGB three-color chip LED technology is applied to the backlight module again due to the technical promotion of the red and green chips in recent years and the substantial reduction of the cost.

As shown in fig. 1 and 2, a package groove 11 ' is formed in the bracket 1 ', three color chips 2 ' are disposed in the package groove 11 ', and the three chips 2 ' are all soldered to the electrode connection regions 3 ' so as to be electrically connected to a circuit inside the bracket 1 '. In order to meet the requirements of white light emission and luminous brightness of the LED, the size of the packaged RGB chips is different. Because the diameter of the cup mouth of the packaging support 1 ' is 2.6mm, and the diameter of the bottom is 2.1mm, the three chips 2 ' must meet a certain size proportion when in the packaging groove 11 ', and meanwhile, the size needs to be ensured to be as large as possible, so that the brightness requirement of the LED is met. However, the RGB three-color chip LED currently used in the backlight module has the phenomenon that one side of the LED is reddish and the other side is cyan when emitting light, and particularly, after the secondary lens is added, the light spot still has the phenomenon that one side of the LED is reddish and the other side is cyan, which seriously affects the display effect of the backlight module.

Disclosure of Invention

One objective of the present invention is to provide an LED package structure that can emit uniform white light to eliminate the color cast problem.

In order to achieve the purpose, the invention adopts the following technical scheme:

an LED package structure comprising:

the bracket is provided with a packaging groove;

the chip set is arranged in the packaging groove and comprises a first chip positioned in the center of the packaging groove, a second chip arranged around the first chip and a third chip; and

and the reflecting layer is only arranged above the first chip.

At least two third chips and at least two second chips are arranged on the third chip and the second chips, and the third chips and the second chips are arranged in a staggered mode.

The first chip, the second chip and the third chip are respectively connected with the corresponding conductive paths.

Wherein, LED packaging structure still includes:

the lens is buckled on the bracket; and

a diffuser layer between the lens and the support.

The bottom of the lens is provided with a groove, and the diffusion layer is located in the groove.

The central axis of the diffusion layer, the central axis of the light incident surface of the lens and the central axis of the light emergent surface of the lens are overlapped.

The diffusion layer completely covers an irradiation surface formed on the lens by the light rays emitted by the chip set.

Wherein the thickness of the diffusion layer is 0.5-1 mm.

Another objective of the present invention is to provide a backlight module to eliminate the color cast problem.

a backlight module comprises the LED packaging structure.

It is a further object of the present invention to provide a display device that eliminates the color shift problem and improves the display effect.

a display device comprises the backlight module.

The invention has the beneficial effects that:

the invention provides an LED packaging structure, a backlight module and display equipment. Among this LED packaging structure, be provided with three kinds of chips, wherein first chip can be for sending the blue light, its center, ruddiness and green glow can be sent respectively to second chip and third chip, second chip and third chip distribution are in the periphery of first chip, the blue light that first chip sent is to diffusion all around under the effect of reflector layer, and mix with ruddiness and green glow and form white light, be favorable to improving the homogeneity that three-color light mixes, avoid the color cast problem, improve the display effect.

Drawings

FIG. 1 is a top view of a prior art LED package structure;

FIG. 2 is a cross-sectional view of a prior art LED package structure;

FIG. 3 is a top view of an LED package structure provided by the present invention;

FIG. 4 is a schematic structural diagram of an LED package structure provided by the present invention;

FIG. 5 is a cross-sectional view of an LED package structure provided by the present invention;

FIG. 6 is a schematic diagram of a refractive lens according to the present invention;

FIG. 7 is a cross-sectional view of a refractive lens provided in accordance with the present invention after assembly with a diffusion layer;

FIG. 8 is a schematic structural diagram of a reflective lens provided in accordance with the present invention;

FIG. 9 is a cross-sectional view of a reflective lens provided in accordance with the present invention after assembly with a diffuser layer;

fig. 10 is a schematic diagram of light propagation in the LED package structure provided by the present invention.

Wherein:

1', a bracket; 11', a packaging groove; 2', a chip; 3', an electrode connecting region;

1. a support; 11. a packaging groove; 21. a first chip; 22. a second chip; 23. a third chip; 31. a first conductive connection region; 32. a second conductive connection region; 33. a third conductive connection region; 4. a reflective layer; 5. a lens; 51. a light incident surface; 52. a light-emitting surface; 6. a diffusion layer; 7. a substrate.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "secured" are to be construed broadly and encompass, for example, both fixed and removable connections; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in direct contact with the second feature but being in contact with the second feature by another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

The present embodiment provides a display device which may be a device having an image display function such as a television, a monitor, an advertisement machine, or the like. The display device comprises a display panel and a backlight module. The backlight module provides a uniform surface light source for the display panel so as to meet the display requirement.

The backlight module comprises a back plate, a light source and an optical component. The back plate is used as a supporting structure of the backlight module and is used for fixing the light source and the optical assembly. Light emitted by the light source passes through the optical assembly and then is formed on the display panel, and the light source is a surface light source.

In this embodiment, the light source may be an LED package structure. As shown in fig. 3, the LED package structure includes a support 1, a chip, and a package layer (not shown). Be provided with encapsulation groove 11 on support 1, support 1 is inside can form the electrically conductive route through the mode of pre-buried sheetmetal, and the part of sheetmetal stretches into in the encapsulation, forms the electrically conductive joining region of being connected with the chip electricity, and the chip contacts with the electrically conductive joining region to communicate chip and electrically conductive route. The encapsulation layer is disposed over the chip to seal and protect the chip so as to fix the chip in the encapsulation groove 11.

Because of the working requirement of the backlight module, the light source in the backlight module needs to emit white light, in the prior art, three chips are placed in the packaging groove 11, and the three color lights emitted by the three chips are mixed to form white light. Due to the requirement of the brightness of the light source, the sizes of the three chips need to have a certain proportion, so that three color lights with different brightness are mixed to form white light meeting the requirement. The LED packaging structure has the color cast problem, even if secondary lens light mixing is used in a matched mode, the serious color cast problem still exists, and the display effect of the backlight module is seriously influenced.

In order to solve the above problem, as shown in fig. 3 to 5, the LED package structure includes a chip set having a plurality of chips, the chip set includes a first chip 21 located in the package slot 11, and a second chip 22 and a third chip 23 disposed around the first chip 21, and a reflective layer 4 is disposed above the first chip 21. Alternatively, the first chip 21 may be a chip emitting blue light, and the second chip 22 and the third chip 23 may be chips emitting red light and green light. When the LED packaging structure works, blue light emitted by the first chip 21 diffuses around under the action of the reflecting layer 4, and is mixed with red light emitted by the second chip 22 and green light emitted by the third chip 23 to form white light, so that the uniformity of three-color light mixing is improved, monochromatic light is prevented from being directly emitted, the color cast problem is solved, and the display effect is improved.

Alternatively, the first chip 21 may be a blue LED chip, the second chip 22 may be a red LED chip, and the third chip 23 may be a green LED chip. The first chip 21, the second chip 22, and the third chip 23 may be configured to emit blue light, red light, and green light.

Alternatively, the first chip 21, the second chip 22 and the third chip 23 may be light emitting diodes in a forward, flip or vertical structure, and the bottom of the light emitting diodes is fixed in the package groove 11 by die attach adhesive or solder.

In order to make the emergent light of each part of the LED packaging structure be uniform white light, more than two second chips 22 and more than two third chips 23 can be arranged, and the third chips 23 and the second chips 22 are arranged on the periphery of the first chip 21 in a staggered mode, so that the light of three colors is distributed in each direction of the first chip 21, and the three color light can be better mixed.

In this embodiment, two second chips 22 and two third chips 23 are provided. By providing two second chips 22 and two third chips 23, the sizes of the second chips 22 and the third chips 23 can be increased as much as possible under the condition that the size of the package slot 11 is constant, so that the LED package structure has sufficient brightness.

Alternatively, the reflective layer 4 may cover the top surface of the first chip 21, and may be a white film layer made of silicon dioxide, which is beneficial to improving the reflectivity of the reflective layer 4.

Alternatively, the first chip 21, the second chip 22, and the third chip 23 may each be a rectangular parallelepiped structure emitting light in five planes. The reflective layer 4 is disposed above the first chip 21, so that light emitted from the top surface of the first chip 21 can be reflected to the periphery of the first chip 21 through the reflective layer 4, so as to be mixed with red light and green light around the first chip 21. The light emitted from the remaining four sides of the first chip 21 is directly mixed with the red and green light. Through setting up first chip 21, second chip 22 and third chip 23 for the cuboid structure that has five light emitting surfaces, be favorable to improving LED packaging structure's light luminance.

Optionally, the top surface of the sealing layer is not higher than 90% of the depth of the package groove 11, so that the emergence of light rays is not affected on the basis of ensuring the packaging effect of the chip.

In the prior art, a better light mixing effect is obtained by controlling the size proportion of a three-color chip. However, the size ratio of the chip is limited by the brightness requirement and the space in the package slot 11, and the light mixing effect cannot be ensured on the basis of ensuring the brightness.

In order to solve the above problem, in this embodiment, three conductive paths are disposed in the support 1, and the first chip 21, the second chip 22 and the third chip 23 are respectively connected to the corresponding conductive paths, so that the first chip 21, the second chip 22 and the third chip 23 are respectively and independently controlled, and the intensity of blue light, red light and green light is controlled by controlling the operating currents of the first chip 21, the second chip 22 and the third chip 23, thereby achieving an ideal light mixing effect. Compare among the prior art, obtain the light luminance of different intensity through the size proportion of chip, the current of three kinds of chips is adjusted through the adjustment to this embodiment, can adjust the proportion of blue light, red light and green light, realizes mixing white light, and the size of chip is unrestricted, and it is more convenient, nimble to adjust.

Specifically, referring to fig. 3, three independent metal sheets may be embedded in the support 1, and one end of each metal sheet extends out of the support 1 to serve as a conductive pin of the LED package structure. Each metal sheet is connected with a conductive connection area exposed on the bottom surface of the packaging groove 11, and the conductive connection area can be the metal sheet itself or other conductive structures electrically connected with the metal sheet. The three conductive connection areas are a first conductive connection area 31 connected to the first chip 21 by gold wire or solder, a second conductive connection area 32 connected to the second chip 22, and a third conductive connection area 33 connected to the third chip 23.

Alternatively, the metal sheet may be made of copper, aluminum or silver, and the surface of the metal sheet may be plated with a silver layer or a nickel layer. The holder 1 may be made of a white material having a high reflectance such as Electro Magnetic Compatibility (EMC), Sheet Molding Compound (SMC), Polyphosphoric Acid (PPA), and 1, 4-cyclohexanedimethanol terephthalate (PCT), or ceramic, which is advantageous for light to be emitted out of the holder 1.

In order to facilitate the connection of the plurality of second chips 22 and the plurality of third chips 23 with the corresponding conductive connection regions, the second conductive connection regions 32 and the third conductive connection regions 33 each include an arc-shaped segment centered on the first chip 21, and the second chips 22 and the third chips 23 distributed on the periphery of the first chip 21 are at least partially disposed in the corresponding conductive connection regions to facilitate the electrical connection.

The LED packaging structure further comprises a lens 5, the lens 5 covers the support 1, and light emitted by the chip is emitted out through the lens 5, so that the mixing effect of the light and the uniformity of diffusion are improved.

Alternatively, the lens 5 may be a refractive lens 5 as shown in fig. 6 and 7, or may be a reflective lens 5 as shown in fig. 8 and 9. After the light rays are emitted through the refraction type lens 5 or the reflection type lens 5, circular or oval light spots are formed, the light spots have a certain diffusion angle, and uniform surface light sources can be formed through the light spots.

The bottom of the lens 5 is provided with an inner concave area, the inner wall of the inner concave area forms a light incident surface 51, the top surface of the lens 5 forms a light emergent surface 52, light enters the lens 5 from the light incident surface 51, and is refracted or reflected by the lens 5 to be emitted from the light emergent surface 52, so that light spots with uniform brightness are formed.

Alternatively, the lens 5 may be made of optical grade Polymethyl Methacrylate (PMMA), Polycarbonate (PC), Polystyrene (PS), or glass.

For further improvement to the light diffusion effect, be provided with diffusion barrier 6 between lens 5 and the support 1, light further mixes, the diffusion back through diffusion barrier 6, carries out the secondary diffusion in reentrant lens 5, is favorable to improving the homogeneity of light and the mixed effect of three-colour light.

Alternatively, the diffusion layer 6 may be made of transparent optical grade organic glass (PMMA), Polycarbonate (PC), Polystyrene (PS) or glass doped with organic or inorganic diffusion particles. The diffusion layer 6 may be, but not limited to, a circular shape, as long as the light emitted from the chip can be diffused by the diffusion layer 6 and then enter the lens 5.

In order to improve the position accuracy of the light spot formed by the light emitted from the chip passing through the lens 5, the central axis of the light incident surface 51, the central axis of the light emitting surface 52 and the central axis of the diffusion layer 6 are overlapped.

In order to ensure that all light rays can pass through the diffusion layer 6, the diffusion layer 6 completely shields the light incident surface 51 of the lens 5, and the diffusion layer 6 completely covers the irradiation surface formed on the lens 5 by the light rays emitted by the chip set, so that light rays are prevented from being missed.

Optionally, the thickness of the diffusion layer 6 may be 0.5-1mm, and the diffusion effect on light rays can be ensured within this range, and the loss of light rays can also be reduced, which is beneficial to improving the brightness of the LED package structure.

Optionally, the bottom of the lens 5 may also be provided with a groove, and the diffusion layer 6 is accommodated in the groove, which is beneficial to improving the fixing effect of the diffusion layer 6, reducing the size of the LED package structure, and making the structure more compact.

Alternatively, the diffusion layer 6 can be formed by injection molding or extrusion molding, and the processing is convenient and the cost is low.

As shown in fig. 10, the LED package structure further includes a substrate 7, one or more supports 1 may be disposed on the substrate 7, and each support 1 is disposed with a chip set and a lens 5. When the LED package structure works, blue light (dotted line shown in fig. 10) generated by the first chip 21 diffuses toward the periphery thereof, and is mixed with red light and green light emitted by the second chip 22 and the third chip 23 on the periphery, and the mixed light enters the lens 5 for secondary diffusion after passing through the diffusion layer 6, so as to form light spots with uniform brightness.

In other embodiments, the first chip 21, the second chip 22 and the third chip 23 may also adopt other color combinations to obtain the required light mixing effect.

The above description is only a preferred embodiment of the present invention, and for those skilled in the art, the present invention should not be limited by the description of the present invention, which should be interpreted as a limitation.

Claims

1. An LED package structure, comprising:

the device comprises a support (1), wherein a packaging groove (11) is formed in the support (1);

the chip set is arranged in the packaging groove (11) and comprises a first chip (21) positioned in the center of the packaging groove (11), a second chip (22) and a third chip (23) which are arranged around the first chip (21), at least two third chips (23) and at least two second chips (22) are arranged, and the third chips (23) and the second chips (22) are arranged in a staggered mode;

a reflective layer (4), the reflective layer (4) being disposed only above the first chip (21); and

the chip packaging structure is characterized in that three conductive paths are arranged in the support (1), the first chip (21), the second chip (22) and the third chip (23) are respectively connected with the corresponding conductive paths, each conductive path comprises a first conductive connection area (31) connected with the first chip (21) through a gold wire or soldering tin, a second conductive connection area (32) connected with the second chip (22) and a third conductive connection area (33) connected with the third chip (23), the second conductive connection area (32) and the third conductive connection area (33) respectively comprise arc sections with the first chip (21) as a circle center, and the second chip (22) and the third chip (23) distributed on the periphery of the first chip (21) are at least partially arranged in the corresponding conductive connection areas.

2. The LED package structure of claim 1, wherein the LED package structure further comprises:

the lens (5) is buckled on the bracket (1); and

a diffuser layer (6), the diffuser layer (6) being located between the lens (5) and the support (1).

3. The LED package structure according to claim 2, characterized in that the bottom of the lens (5) is provided with a groove, the diffusion layer (6) being located in the groove.

4. The LED package structure of claim 2, wherein a central axis of the diffusion layer (6), a central axis of the light incident surface (51) of the lens (5), and a central axis of the light emitting surface (52) of the lens (5) coincide.

5. The LED package structure of claim 2, wherein said diffusion layer (6) completely covers the illuminated surface of said chip set on said lens (5) from which light is emitted.

6. The LED package structure according to claim 2, characterized in that the thickness of the diffusion layer (6) is 0.5-1 mm.

7. A backlight module comprising the LED package structure of any one of claims 1-6.

8. A display device comprising the backlight module of claim 7.