CN114284420A

CN114284420A - Light emitting unit, manufacturing method thereof and light emitting assembly

Info

Publication number: CN114284420A
Application number: CN202111617888.XA
Authority: CN
Inventors: 孙平如; 谭青青
Original assignee: Shenzhen Jufei Optoelectronics Co Ltd
Current assignee: Shenzhen Jufei Optoelectronics Co Ltd
Priority date: 2021-12-27
Filing date: 2021-12-27
Publication date: 2022-04-05

Abstract

The invention relates to a light-emitting unit, a manufacturing method thereof and a light-emitting component, wherein lenses on miniature flip LED chips are manufactured through a mold, the consistency of the lenses can be ensured, the manufacturing process is simple, the efficiency is high, and the cost is low; the light conversion particles for converting the color of the light emitted by the miniature flip LED chip are arranged in each lens, so that the use of a QD film can be omitted, the uniformity of the light emission can be improved, the cost can be reduced, and the structure of the display module can be simplified; when the light-emitting unit is used for manufacturing light-emitting components such as a display module and the like, the light-emitting unit can be directly and fixedly arranged on the circuit board and electrically connected with the circuit board, and the manufacturing process is simple and efficient; the manufactured display module does not need a QD film any more, and has simple structure and low cost; and the lens consistency of each used light-emitting unit is good, so that the light color of the light-emitting component is more uniform, and the display quality is higher.

Description

Light emitting unit, manufacturing method thereof and light emitting assembly

Technical Field

The invention relates to the field of light emitting, in particular to a light emitting unit, a manufacturing method thereof and a light emitting assembly.

Background

Ultra-high definition video is the development direction in the future, and the Mini LED and the Micro LED can be used as backlight and direct display. The Mini LED can be controlled in an area as a backlight of an LCD (Liquid Crystal Display), can greatly improve the peak brightness, the contrast and the image reducibility of a Liquid Crystal screen, and can also reduce the power consumption.

The process of the backlight manufactured by the existing blue light Mini LED backlight module is shown in fig. 1, and includes:

s101: the blue Mini LED chip 12 and the circuit board 11 are prepared, and solder paste or flux is applied to the circuit board 11.

S102: and accurately placing the electrodes of the blue Mini LED chips 12 downwards at the positions of solder paste and soldering flux on the circuit substrate 11, and reflowing and fixing the blue Mini LED chips 12 to be communicated with a circuit in a nitrogen protection reflow soldering furnace.

S103: transparent glue 14 is dispensed above the blue Mini LED chip 12 by a dispenser 13.

S104: and forming the blue Mini LED backlight module with the transparent lens 15 after the transparent adhesive 14 is molded.

When the blue light Mini LED backlight module manufactured in the prior art is used for manufacturing a display screen, a QD (Quantum Dots) film needs to be arranged on the blue light Mini LED backlight module to convert the color of blue light emitted by the blue light Mini LED chip 12, and the QD film is expensive; meanwhile, the blue light contains high-energy long-wave ultraviolet UVA and low-wavelength blue light spectrum, so that colloidal molecular chains of the transparent adhesive 14 are easily damaged, the transparent adhesive 14 is easy to yellow and crack and even break away to lose efficacy, and the reliability of the product is reduced. In addition, the transparent lens 15 formed by dispensing through the dispenser 13 is limited by the poor consistency of the shape and the size of the transparent lens 15 formed on each blue Mini LED chip 12 caused by the dispensing process, so that the blue Mini LED backlight module generates uneven light color and is difficult to repair.

Therefore, how to solve the problems of poor consistency of the transparent lens on the existing blue light Mini LED backlight module, high cost, poor reliability of the display screen manufactured by adopting the blue light Mini LED backlight module, and uneven generated light color is a technical problem which needs to be solved urgently at present.

Disclosure of Invention

In view of the above-mentioned deficiencies of the related art, an object of the present invention is to provide a light emitting unit, a manufacturing method thereof, and a light emitting assembly, which are used to solve the problems of poor uniformity of transparent lenses on the existing blue-light Mini LED backlight module, high cost, poor reliability of a display screen manufactured by using the blue-light Mini LED backlight module, and uneven light color.

A method for manufacturing a light emitting unit comprises the following steps:

providing a mold and an LED chip assembly; a plurality of lens cavities which are mutually isolated are formed on the mould; the LED chip assembly comprises a chip bearing substrate and a plurality of miniature flip LED chips which are detachably and fixedly arranged on the bearing substrate, wherein one side of each miniature flip LED chip provided with an electrode is fixedly arranged on the bearing substrate, and the distribution of the miniature flip LED chips on the bearing substrate is in one-to-one correspondence with the distribution of the lens die cavities on the die;

filling liquid colloid into each lens mold cavity, wherein light conversion particles are mixed in the colloid;

aligning and pressing the miniature flip LED chips on the bearing substrate and the lens mold cavity on the mold, wherein each miniature flip LED chip is respectively embedded into the colloid in the corresponding lens mold cavity;

curing the colloid, and forming a lens covered on the miniature flip LED chip after the colloid is cured and molded;

and removing the mold and the bearing substrate to obtain a plurality of light-emitting units, wherein each light-emitting unit comprises one miniature flip LED chip and the lens covered on the miniature flip LED chip.

In an embodiment, the filling of the liquid colloid into each lens cavity includes:

filling liquid colloid into each lens mold cavity, wherein the filled colloid is flush with the lens mold cavity;

the contraposition and pressing of the miniature flip-chip LED chip on the bearing substrate and the lens mold cavity on the mold comprises the following steps:

aligning and pressing the miniature flip LED chip on the bearing substrate and the lens mold cavity on the mold until one surface of the bearing substrate, on which the miniature flip LED chip is fixedly arranged, is attached to the cavity opening of the lens mold cavity;

and obtaining separated single light-emitting units after removing the mould and the bearing substrate.

filling liquid colloid into each lens cavity, wherein the filled colloid overflows each lens cavity, and the colloid overflowing the lens cavities forms a flat adhesive layer on each lens cavity;

aligning and pressing the miniature flip LED chip on the bearing substrate and the lens mold cavity on the mold until one surface of the bearing substrate, on which the miniature flip LED chip is fixedly arranged, is attached to the flat adhesive layer;

after the colloid is solidified and molded, the colloid positioned between the lenses forms an extension layer for connecting the lenses.

In one embodiment, the removing the mold and the carrier substrate includes:

removing the mold and then removing the bearing substrate;

after removing the mold, before removing the carrier substrate, or after removing the carrier substrate, further comprising:

and cutting the extension layer according to a preset rule to obtain separated light-emitting unit groups, wherein one light-emitting unit group comprises at least one light-emitting unit.

In an embodiment, the cutting the extension layer according to the preset rule includes at least one of:

cutting along the extension layer and an interface region of the lens adjacent to the extension layer;

the cutting is performed along the middle area of the extension layer between two adjacent rows and/or two columns of the lenses.

In one embodiment, the carrier substrate is a glass substrate, and the providing the LED chip assembly includes:

providing a glass substrate;

and adhering one side of the miniature flip LED chip provided with the electrode to the glass substrate through an adhesive film.

In an embodiment, the providing the mold comprises:

a mold made of glass is provided, and the plurality of lens cavities are distributed in an array on the mold.

In an embodiment, the light conversion particles include phosphor and/or quantum dot particles, and before filling the liquid colloid into each lens cavity, the method further includes preparing the colloid;

the preparing the colloid comprises the following steps: phosphor and/or quantum dot particles are mixed into the colloid.

Based on the same inventive concept, the light-emitting unit is also provided, and the light-emitting unit is manufactured by the manufacturing method of the light-emitting unit.

Based on the same inventive concept, a manufacturing method of the light emitting assembly is also provided, which comprises the following steps:

providing a circuit board, wherein the circuit board is provided with welding pads corresponding to the electrodes of the miniature flip LED chip respectively;

the light-emitting unit manufactured by the light-emitting unit manufacturing method is arranged on the circuit board, and the electrodes of the micro flip LED chip of the light-emitting unit are correspondingly and electrically connected with the bonding pads.

The invention provides a light-emitting unit, a manufacturing method thereof and a light-emitting component, wherein a plurality of lens die cavities which are mutually isolated are formed on a die, one sides of a plurality of miniature flip LED chips, which are provided with electrodes, are fixedly arranged on a bearing substrate, and the distribution of the miniature flip LED chips on the bearing substrate corresponds to the distribution of the lens die cavities on the die one by one; firstly, filling liquid colloid mixed with light conversion particles in a lens die cavity, then aligning and laminating a miniature flip LED chip on a bearing substrate and the lens die cavity on a die, and forming a lens covering the miniature flip LED chip after the colloid is solidified and molded, wherein the lens at least has the following advantages:

the lenses on the miniature flip LED chips are manufactured through the molds, so that the consistency of the shapes and the sizes of the lenses can be ensured, the manufacturing process is simple, mature and reliable, and the manufacturing efficiency is high, cost is low;

the lenses are internally provided with light conversion particles for converting the color of light emitted by the miniature flip LED chip, so that the use of a QD film can be omitted when the lenses are applied to a display module, the uniformity of light emission can be improved, the cost can be reduced, and the structure of the display module can be simplified; meanwhile, when the blue LED chip is adopted as the miniature flip LED chip, the blue light emitted by the miniature flip LED chip can be converted into other colors by the light conversion particles, and the long-wave ultraviolet UVA and the low-wave blue light spectrum of the blue light are prevented from damaging the molecular chains of the colloid forming the lens, so that the colloid forming the lens is prevented from yellowing and cracking and even breaking away from failure, and the reliability of the product can be improved;

when the light-emitting unit is used for manufacturing light-emitting components such as a display module and the like, the light-emitting unit can be directly and fixedly arranged on the circuit board and electrically connected with the circuit board, and the manufacturing process is simple and efficient; the manufactured display module does not need a QD film any more, and has simple structure and low cost; and the lens consistency of each used light-emitting unit is good, so that the light color of the light-emitting component is more uniform, and the display quality is higher.

Drawings

FIG. 1 is a schematic view illustrating a conventional backlight module;

fig. 2 is a schematic flow chart of a method for manufacturing a light-emitting unit according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating a manufacturing process of a light emitting unit according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a micro flip-chip LED chip according to an embodiment of the present invention;

FIG. 5 is a schematic view of a glue being flush with a lens cavity according to an embodiment of the present invention;

fig. 6 is a first schematic structural diagram of a light emitting unit according to an embodiment of the present invention;

fig. 7 is a schematic diagram of light emitting from a light emitting unit according to an embodiment of the invention;

FIG. 8 is a schematic diagram of another process for fabricating a light-emitting unit according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of a gel-overflowing lens cavity provided by an embodiment of the present invention;

FIG. 10 is a first schematic view of a cutting operation according to an embodiment of the present invention;

FIG. 11 is a schematic view of the light-emitting unit cut in FIG. 10;

FIG. 12 is a second schematic diagram of a cutting operation according to an embodiment of the present invention;

FIG. 13 is a schematic view of the light-emitting unit cut in FIG. 12;

FIG. 14 is a third schematic view of a cut provided by an embodiment of the present invention;

fig. 15 is a schematic view of the luminous element groups obtained after cutting in fig. 14;

fig. 16 is a schematic diagram illustrating a distribution of light emitting cells in a light emitting cell group according to an embodiment of the present invention;

FIG. 17 is a fourth schematic view of a cut provided by an embodiment of the present invention;

fig. 18 is a schematic view of the luminous element groups obtained after cutting in fig. 17;

fig. 19 is a schematic diagram illustrating a distribution of light emitting cells in another light emitting cell group according to an embodiment of the present invention;

FIG. 20 is a schematic flow chart illustrating a method for fabricating a light emitting device according to an embodiment of the present invention;

FIG. 21 is a first schematic view illustrating a manufacturing process of a light emitting device according to an embodiment of the present invention;

FIG. 22 is a second schematic view illustrating a manufacturing process of a light emitting device according to an embodiment of the present invention;

fig. 23 is a third schematic view illustrating a manufacturing process of a light emitting device according to an embodiment of the present invention.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In the related art, the consistency of the transparent lens on the blue Mini LED backlight module is poor, and the display screen manufactured by the blue Mini LED backlight module has high cost, poor reliability and uneven generated light color.

Based on this, the present invention intends to provide a solution to the above technical problem, the details of which will be explained in the following embodiments.

For convenience of understanding, the following description of the present embodiment first takes a manufacturing method of a light emitting unit as an example, please refer to fig. 2, which includes but is not limited to:

s201: a mold and an LED chip assembly are provided.

The present embodiment provides a mold having a plurality of lens cavities formed therein that are isolated from one another. In one example, the mold has a top surface and a bottom surface opposite the top surface, and the mold has an upper end near the top surface and a lower end near the bottom surface. A plurality of lens cavities are formed in the upper end of the mold, with the bottom of each lens cavity being adjacent to the bottom surface of the mold and the top of each lens cavity, i.e., the opening of each lens cavity, being at the top surface of the mold. In this embodiment, the shape and size of the lens cavity may be specifically set according to the shape and size of the lens to be formed. The type of lens to be formed in the present embodiment can be flexibly set according to the requirement, and for example, the lens can be, but is not limited to, a refractive lens, and can also be a dome-type lens thereof. In this embodiment, the lens function can be used to increase the light-emitting angle, that is, functionally, the lens in this embodiment can be a wide-angle lens.

It should be understood that the mold in this embodiment may be made of various materials. In one example, the material for facilitating the separation of the colloid may be used, for example, in an application example, the providing of the mold may include a mold made of glass (e.g., borosilicate glass), the glass mold has low cost, is convenient to manufacture, and is easy to separate from the colloid, for example, the colloid may be separated from the glass mold during the thermal curing process, so that the use of a release agent during the releasing process may be omitted, thereby improving the manufacturing efficiency and reducing the cost. Of course, in other application examples, a mold made of other materials may be used, and a mold release agent may be used according to the requirements, and the mold release agent in this application example may be, but is not limited to, organic oil, liquid paraffin, vaseline, 201 ointment, No. 4 high temperature grease, and the like. It should be understood that in some application scenarios, when a glass mold is used, a mold release agent may also be employed to further facilitate subsequent mold release operations.

In this example, the distribution of the plurality of lens cavities on the mold can also be flexibly configured, for example, in some application examples, the plurality of lens cavities can be distributed in an array, or can be distributed in other manners, such as a row, a column colloid distribution, or a single row/single column distribution; of course, they may be distributed in irregular shapes, such as randomly distributed, etc. The method can be flexibly set according to application requirements.

The LED chip assembly provided by the embodiment comprises a chip bearing substrate and a plurality of miniature flip LED chips which are detachably and fixedly arranged on the bearing substrate. In this embodiment, one side of the micro flip-chip LED chip (i.e., the bottom surface of the micro flip-chip LED chip) where the electrodes are disposed is fixedly disposed on the carrier substrate, and the distribution of the micro flip-chip LED chips on the carrier substrate corresponds to the distribution of the lens cavities on the mold one-to-one. It should be understood that the Micro flip LED chip in the present embodiment may include, but is not limited to, at least one of a flip Mini LED chip and a flip Micro LED chip. In addition, the light emitting color of the micro flip LED chip in this embodiment can be flexibly set according to the application requirement, for example, a blue light micro flip LED chip can be used, a green light or red light flip LED chip can also be used, and the like.

The chip carrier substrate in this embodiment has at least the following effects, on one hand, the carrier substrate can be used for carrying a plurality of miniature flip-chip LED chips, and on the other hand, the carrier substrate can utilize the weight of the carrier substrate to ensure the smoothness after die assembly (that is, the carrier substrate can be used as an upper die, and the die is used as a lower die) in the subsequent die assembly process with the die, so that the consistency and yield of the manufactured lens covering each miniature flip-chip LED chip are improved. And it should be understood that, in an application example of the present embodiment, one micro flip-chip LED chip on the carrier substrate may be arranged to correspond to one lens cavity on the mold, that is, the micro flip-chip LED chip corresponds to one lens cavity. Of course, in other application examples, two or three or more micro flip-chip LED chips on the carrier substrate may be disposed according to requirements to correspond to one lens mold cavity, that is, one lens mold cavity may be disposed with a plurality of micro flip-chip LED chips, so as to meet the diversified requirements of different application scenarios.

In this embodiment, the material of the carrier substrate may be the same as that of the mold, for example, in an application example, providing the LED chip assembly includes: providing a glass substrate; and adhering one side of the miniature flip LED chip provided with the electrode to the glass substrate through an adhesive film. Of course, the carrier substrate in this embodiment is not limited to a glass substrate, and an aluminum substrate, an iron substrate, a ceramic substrate, or the like having a certain weight may be used.

In this embodiment, the fixing mode that the miniature flip-chip LED chip is detachably fixed on the bearing substrate can be flexibly set. For example, an adhesive layer (for example, but not limited to, a thermal adhesive) may be disposed on one side of the carrier substrate, and the micro flip-chip LED chip is bonded through the adhesive layer. For another example, in some examples, an adhesive film layer, such as a blue film, may be disposed on one side of the carrier substrate, through which the micro flip-chip LED chip is adhered to the carrier substrate.

S202: and filling liquid colloid into each lens mold cavity, wherein the colloid is mixed with light conversion particles.

In the present embodiment, the light conversion particles mixed in the colloid may include, but are not limited to, at least one of phosphor and quantum dot particles. For example, in some application examples, the phosphor may be mixed in the gel, and the type of the mixed phosphor may be flexibly set according to the light emitting color of the micro flip-chip LED chip and the desired target light color (i.e., the light color obtained after the conversion by the phosphor). For example, in some application scenarios, when the light emitting color of the micro flip-chip LED chip is blue and the target light color is white light, the disposed phosphors may include various phosphors that convert the blue light into the white light, such as YAG yellow phosphor. The fluorescent powder is adopted in the application example, so that the cost is low, the universality is good, and the requirement on the light-emitting quality can be met. In another application example, quantum dot particles can be mixed in the colloid, and the type of the mixed quantum dot particles can also be flexibly set according to the light emitting color of the specifically adopted miniature flip-chip LED chip and the required target light color. Of course, in another application example, the phosphor and the quantum dot particles may be mixed in the colloid, and the types of the mixed phosphor and quantum dot particles may also be flexibly set according to the light emitting color of the specifically adopted micro flip LED chip and the required target light color, which is not described in detail herein. Of course, it should be understood that in some application scenarios where the light-emitting color of the micro flip-chip LED chip does not need to be converted, the light conversion particles may not be disposed in the colloid in the embodiment, that is, the colloid may directly adopt transparent glue.

The material of the colloid in this embodiment can be flexibly set, for example, a thermosetting colloid or a thermoplastic colloid can be used. In some specific application scenarios, the colloid may be, but is not limited to, a resin adhesive or an epoxy adhesive, and the details are not repeated here.

In this embodiment, the manner of filling the liquid colloid into each lens cavity may be flexibly adopted, for example, but not limited to, the manners of glue injection and dispensing, silk screen printing, and the like may be flexibly adopted. In addition, in the embodiment, the colloid is injected into the lens mold cavities on the molds, and the colloid is directly injected into the lens mold cavities through the openings of the lens mold cavities, so that no additional glue injection opening is required to be formed in the mold, and the mold has the advantages of simple structure, low cost, high injection efficiency and good controllability.

S203: and aligning and pressing the miniature inverted LED chips on the bearing substrate with the lens mold cavity on the mold, and respectively embedding the miniature inverted LED chips into the colloid in the corresponding lens mold cavity.

In some application examples of this embodiment, can be with the accent of lens die cavity up, directly with the miniature flip-chip LED chip on the carrier substrate with the lens die cavity on the mould after counterpointing, place the carrier substrate on the mould to can directly utilize the weight of carrier substrate to realize the pressfitting, can guarantee the planarization of compound die simultaneously, and then guarantee the uniformity and the yields of follow-up lens that makes. In the application example, the bearing substrate and the die do not need to be pressed by additional pressure equipment, so that the manufacturing process can be further simplified, the manufacturing cost is reduced, and the manufacturing efficiency is improved.

S204: and curing the colloid, and forming a lens covered on the miniature flip LED chip after the colloid is cured and molded.

In this embodiment, the manner in which the gel is cured may be set according to the particular type of gel employed. For example, when the colloid is a thermosetting colloid or a thermoplastic colloid, the colloid can be cured by, but not limited to, heating.

S205: and removing the mold and the bearing substrate to obtain a plurality of light-emitting units, wherein each light-emitting unit comprises a miniature flip LED chip and a lens covered on the miniature flip LED chip.

In this embodiment, when removing the mold and the carrier substrate, the mold may be removed first, then the carrier substrate may be removed, or the carrier substrate may be removed first, then the mold may be removed, or both the removal steps may be performed simultaneously. The light-emitting unit obtained in the embodiment comprises a miniature flip LED chip and a lens covered on the miniature flip LED chip, and the lens on the miniature flip LED chip is manufactured through a mold, so that the consistency of the shape and the size of each lens can be ensured, the manufacturing process is simple, mature and reliable, and the manufacturing efficiency is high, cost is low; the lenses are internally provided with light conversion particles for converting the color of light emitted by the miniature flip LED chip, so that the use of a QD film can be omitted when the lenses are applied to a display module, the uniformity of light emission can be improved, the cost can be reduced, and the structure of the display module can be simplified; meanwhile, when the miniature flip LED chip adopts a blue LED chip, blue light emitted by the miniature flip LED chip can be converted into other colors by the light conversion particles, and the long-wave ultraviolet UVA and the low-wave blue light spectrum of the blue light are prevented from damaging the molecular chains of colloid forming the lens, so that the colloid forming the lens is prevented from yellowing and cracking and even breaking away from failure, and the reliability of the product can be improved.

For ease of understanding, the present embodiment will be described below with two exemplary methods for manufacturing a light emitting unit.

Example one:

in this example, the filling of the liquid colloid into each lens cavity in S202 may include: and filling liquid colloid into each lens mold cavity, wherein the filled colloid is flush with the lens mold cavity. The step S203 of aligning and pressing the micro flip-chip LED chip on the carrier substrate and the lens cavity on the mold includes: and aligning and pressing the miniature flip LED chip on the bearing substrate and the lens mold cavity on the mold until one surface of the bearing substrate, on which the miniature flip LED chip is fixedly arranged, is attached to the cavity opening of the lens mold cavity. In this example, the liquid colloid filled in each lens cavity is flush with the lens cavity, so that after the colloid is solidified and the mold and the bearing substrate are removed, a single separated light-emitting unit can be directly obtained without performing a cutting step, thereby further simplifying the manufacturing process, improving the manufacturing efficiency and reducing the manufacturing cost.

For ease of understanding, the present embodiment is described below with reference to a specific manufacturing example. The manufacturing process is shown in fig. 3, which includes but is not limited to:

s301: a mould 2 is provided. The mould 2 in this example is made of a peng silica glass. The mold 2 is provided with a plurality of lens cavities 21. The lens cavity 21 in this example is a wide angle lens cavity. The lens cavities 21 in this example may be distributed in an array on the mold.

S302: an LED chip assembly is provided. The LED chip assembly in this example comprises a carrier substrate 3, and a flip-chip Mini LED chip 4 detachably fixed on the carrier substrate 3. As shown in fig. 4, the flip Mini LED chip 4 includes a chip body 41 and an electrode 42, the electrode 42 is disposed on a bottom surface of the chip body 41, and a top surface of the chip body 41 is used as a main light emitting surface of the flip Mini LED chip 4. In some examples, the flip Mini LED chip 4 may only emit light from the top surface, or from the top surface and at least one side surface. In this example, a Distributed Bragg Reflector (DBR) may not be disposed on the light emitting surface of the flip Mini LED chip 4, so that the cost can be further reduced, the light emitting efficiency of the flip Mini LED chip 4 can be improved, and the test can improve at least 15% of the light emitting efficiency, thereby improving the brightness and greatly reducing the cost. Of course, in some application examples, the flip Mini LED chip 4 provided with the DBR layer may also be used. It should be understood that the flip Mini LED chip 4 in this example may also be replaced with a Micro LED chip. For ease of understanding, the present example is illustrated with the flip Mini LED chip 4 as a blue LED chip.

S303: a liquid colloid 50 in which light conversion particles are mixed is injected into each lens cavity 21.

In this example, the colloid may be prepared by mixing phosphor and/or quantum dot particles into the colloid and then filling the liquid colloid 50 into each lens cavity 21 by, but not limited to, a molding press or a dispenser. In this example, the lens cavity 21 is filled with a liquid gel 50 flush with the lens cavity 21 (i.e., flush with the top surface of the mold 2). For example, referring to FIG. 5, the maximum depth within the lens cavity 21 is H1 and the maximum height of the filled gel 50 is H1. Of course, it may also be slightly below the top surface of the mould 2. In this example, to ensure that the filled liquid gel 50 is flush with the lens cavity 21, excess gel that may overflow the lens cavity 21 may be removed by, but not limited to, a spatula. For ease of understanding, the present example is illustrated with the light conversion particles being yellow phosphor 52.

S304: and aligning and pressing the inverted Mini LED chip 4 on the bearing substrate 3 and the lens mold cavity 21 on the mold 2 until one surface of the bearing substrate 3 fixedly provided with the inverted Mini LED chip 4 is attached to the cavity opening of the lens mold cavity 21 (namely, attached to the top surface of the mold 2).

S305: the carrier substrate 3 and the mold 2 are placed together in an oven and heated, and the glue 50 is cured to form the lens 53. Of course, it should be understood that the present example is not limited to heating by an oven.

S306: the mold 2 is removed to obtain a plurality of light emitting units detachably fixed on the carrier substrate 3.

S307: the carrier substrate 3 is removed to obtain a plurality of light emitting cells separated from each other as shown in fig. 6. One light emitting unit includes a flip Mini LED chip 4 and a lens 51 covering the flip Mini LED chip 4, and the lens 51 includes yellow phosphor 52. The light emitted by the inverted Mini LED chip 4 enters the lens 51 and is converted by the yellow fluorescent powder 52 in the lens to emit white light.

In this example, the liquid colloid 50 filled in each lens cavity 21 is flush with the lens cavity 21, so that after the colloid 50 is solidified and the mold 2 and the carrier substrate 3 are removed (see step S307), a separate single light-emitting unit can be directly obtained without performing a cutting step, thereby further simplifying the manufacturing process, improving the manufacturing efficiency, and reducing the manufacturing cost. Referring to fig. 7, the light-emitting schematic diagram of a single light-emitting unit manufactured in this example is shown, and compared with the light-emitting angle (less than 140 °) of the LED chip on the backlight module shown in fig. 1, the light-emitting angle of the light-emitting unit in this example can reach 165 ° or more, so when a display module is manufactured by using the light-emitting unit, the distance between chips can be increased, the emitted white light is more uniform, and an ultra-high-definition LCD television (display or the like) does not need a quantum film any more, and the cost can be greatly reduced.

Example two:

in this example, the filling of the liquid colloid into each lens cavity in S202 may include: and filling liquid colloid into each lens cavity, wherein the filled colloid overflows from each lens cavity, and the colloid overflowing from the lens cavity forms a flat adhesive layer on each lens cavity. The step S203 of aligning and pressing the micro flip-chip LED chip on the carrier substrate and the lens cavity on the mold includes: aligning and pressing the miniature flip LED chip on the bearing substrate and the lens mold cavity on the mold until one surface of the bearing substrate, on which the miniature flip LED chip is fixedly arranged, is attached to the flat adhesive layer; since the liquid-state colloid filled in each lens cavity is connected into a whole by the flat adhesive layer formed on each lens cavity in this example, after the colloid is cured and molded, the colloid (i.e., the flat adhesive layer) positioned between the lenses is formed into an extension layer connecting the lenses, that is, a plurality of light emitting units connected into a whole by the extension layer can be obtained. In this example, the plurality of light emitting cells connected as a whole can be cut flexibly according to the requirement, for example, the individual light emitting cells can be obtained by cutting the individual light emitting cells, or the light emitting cell group can be obtained by cutting the individual light emitting cells as units, or by cutting the individual light emitting cells as units of 2 × 1, 2 × 2, 3 × 1, 3 × 2, 3 × 3, 4 × 4, or the like. Of course, in some examples, the cutting step may not be performed, and a predetermined number of light emitting units connected as a whole may be directly obtained. Therefore, the method for manufacturing the light emitting unit can directly manufacture a plurality of light emitting units which are connected into a whole, can selectively cut the light emitting units according to requirements to obtain light emitting unit groups meeting different requirements, and can improve the coverage area of the circuit board when the light emitting unit groups are arranged on the circuit board to manufacture the light emitting component, so that the protection performance of the circuit board is improved, and the reliability of the circuit board is further improved.

In some application scenarios in this example, when the cutting step needs to be performed, the mold may be removed first, and then the carrier substrate may be removed; and after the mould is removed and before the bearing substrate is removed, or after the bearing substrate is removed, cutting the extension layer between the lenses according to a preset rule to obtain separated light-emitting unit groups, wherein one light-emitting unit group comprises at least one light-emitting unit. The cutting of the extension layer using the preset rule in this example may include, but is not limited to, at least one of:

cutting along the extension layer and the boundary region of the lens adjacent to the extension layer;

the cut is made along the middle region of the extended layer between two adjacent rows and/or columns of lenses.

For ease of understanding, the present embodiment is described below with reference to a specific manufacturing example. The manufacturing process is shown in fig. 8, which includes but is not limited to:

s401: a mould 2 is provided. The mould 2 in this example is also made of peng silica glass. The mold 2 is provided with a plurality of lens cavities 21, which will not be described in detail herein.

S402: an LED chip assembly is provided. The LED chip assembly in this example comprises a carrier substrate 3, and a flip-chip Mini LED chip 4 detachably fixed on the carrier substrate 3. The Mini LED chip 4 is flipped as shown in fig. 4, and will not be described herein.

S403: a liquid colloid 50 in which light conversion particles are mixed is injected into each lens cavity 21.

In this example, the liquid colloid 50 filled in the lens cavities 21 is higher than the lens cavities 21 (i.e., higher than the top surface of the mold 2), that is, the filled colloid 50 overflows each lens cavity 21, and the colloid 50 overflowing the lens cavities 21 forms a flattening layer 501 on each lens cavity 21 and between each lens cavity 21. For example, referring to fig. 9 in conjunction with fig. 5, the maximum depth of the lens cavity 21 is H1, the maximum height of the filled encapsulant 50 is H2, and the thickness of the planarization layer 501 is the difference between H2 and H1. In this example, to ensure the flatness of the filled flat adhesive layer 501, the flat adhesive layer 501 may be planarized by, but not limited to, a doctor blade. For ease of understanding, the present example also illustrates the light conversion particles as yellow phosphor 52. It should be understood that the phosphor or the light conversion particles in this example can be flexibly set according to the target light color and the light emitting color of the Mini LED chip used, and are not described in detail herein.

S404: the inverted Mini LED chip 4 on the carrier substrate 3 is aligned and pressed with the lens cavity 21 on the mold 2 until the face of the carrier substrate 3 on which the inverted Mini LED chip 4 is fixedly disposed is attached to the flat adhesive layer 501.

S405: the carrier substrate 3 and the mold 2 are put into an oven and heated, and the glue 50 is cured to form the lenses 53 and the extension layers 531 connecting the lenses 53. Of course, it should be understood that the present example is not limited to heating by an oven.

S406: the mold 2 is removed to obtain a plurality of light-emitting units detachably fixed on the carrier substrate 3, and the plurality of light-emitting units are connected into a whole through the extension layer 531.

In this example, when a plurality of integrally connected light emitting units are flexibly cut according to requirements to obtain a required light emitting unit group, the flexible cutting can be also performed as shown above. For ease of understanding, the present embodiment is described below in terms of several cutting examples.

Cutting example one: referring to fig. 9 and 10, a single light-emitting unit (of course, a plurality of light-emitting units may be used as an example as required) is used as a unit, cutting is performed along the boundary region (the position indicated by the cutting line a0 in fig. 10) between the extension layer 531 and the lens 53 adjacent to the extension layer 531, the structure of the light-emitting unit obtained after cutting is shown in fig. 11, the extension layer 531 between adjacent lenses 53 is removed after cutting, and the cutting surface 532 is formed into a vertical plane, and the area of the cutting surface 532 can further enrich the light-emitting angle of the lens 53 relative to the light-emitting unit shown in fig. 6.

Example two cutting: referring to fig. 12 and 13, a single light emitting unit is used as a unit, cutting is performed along a middle region (a position indicated by a cutting line a1 in fig. 12) of the extension layer 531 between two adjacent lenses 53, the structure of the light emitting unit obtained after cutting is shown in fig. 13, the extension layer 531 between the adjacent lenses 53 is remained after cutting, and compared with the light emitting unit shown in fig. 6, the remained extension layer 531 forms an extension part of the lens 53, which can not only further enrich the wide angle of the lens 53, but also improve the bonding area between the light emitting unit and the circuit board, and improve the bonding strength and density between the light emitting unit and the circuit board.

Cutting example three: referring to fig. 14 to 16, 2 × 2 light emitting units are used as a unit, and the cutting is performed along the middle region (the position indicated by the cutting line a2 in fig. 14 and 16) of the extension layer 531 of the lens 53 between two corresponding adjacent rows and two columns, and the structure of the light emitting unit obtained after the cutting is shown in fig. 15, where the extension layer 531 between the adjacent lenses 53 is remained after the cutting, and the light emitting unit group obtained after the cutting includes 4 light emitting units distributed in an array, as compared with the light emitting unit shown in fig. 6, therefore, the transfer efficiency of the light emitting unit can be increased exponentially, the manufacturing cost of the subsequent light emitting assembly can be reduced, and the coverage area between the light emitting unit group and the circuit board can be further increased, that is, the bonding strength and density between the light emitting unit group and the circuit board can be further increased.

Example four cuts: referring to fig. 17 to 19, with 3 × 3 light emitting units as a unit, cutting is performed along a middle region (a position indicated by a cutting line a3 in fig. 17 and 19) of the extension layer 531 of the lens 53 between two corresponding adjacent rows and two columns, and the structure of the light emitting unit obtained after cutting is as shown in fig. 18, where the extension layer 531 between the adjacent lenses 53 is also retained after cutting, and compared with the light emitting unit shown in fig. 6, the light emitting unit group obtained after cutting includes 9 light emitting units distributed in an array, which can further double the transfer efficiency of the light emitting unit, reduce the manufacturing cost of the subsequent light emitting assembly, and improve the bonding strength and density between the two light emitting unit groups and the circuit board.

As can be seen from the above cutting examples, the cutting of the light emitting unit in the embodiment can be flexibly performed according to specific application requirements, and is not limited to the several cutting manners of the above examples, which is not described herein again.

In this embodiment, after the light emitting units are manufactured, the electrical property of each light emitting unit or each light emitting unit group is measured by a spectroscope, and the voltage, the wavelength (color coordinate), and the luminous flux are separated into BINs and then wound for post-processing mounting. In the embodiment, the lenses on the miniature flip LED chips are manufactured through the die, so that the consistency of the shapes and the sizes of the lenses can be ensured, the manufacturing process is simple, mature and reliable, and the manufacturing efficiency is high and low; and each lens is internally provided with light conversion particles for converting the color of light emitted by the miniature flip LED chip, so that the use of a QD film can be omitted when the lens is applied to a display module, the uniformity of light emission can be improved, the cost can be reduced, and the structure of the display module can be simplified; meanwhile, when the miniature flip LED chip adopts a blue LED chip, blue light emitted by the miniature flip LED chip can be converted into other colors by the light conversion particles, and the long-wave ultraviolet UVA and the low-wave blue light spectrum of the blue light are prevented from damaging the molecular chains of colloid forming the lens, so that the colloid forming the lens is prevented from yellowing and cracking and even breaking away from failure, and the reliability of the product can be improved. In particular, the reliability of light emitting components, such as but not limited to display modules, manufactured by using the light emitting unit can be improved.

For ease of understanding, the present embodiment will be described below by taking the example of fabricating a light emitting assembly by using the light emitting units shown in the above examples, which is shown in fig. 20, and includes but is not limited to:

s2001: and providing a circuit board, wherein the circuit board is provided with welding pads corresponding to the electrodes of the miniature inverted LED chip respectively.

When the light emitting assembly in the embodiment is a display assembly, the circuit board can be various display back boards; when the light emitting module is a lighting module, the circuit board may be various lighting circuit boards.

In this embodiment, the circuit board may be, but is not limited to, a conductive metal substrate, and the two may be made of the same material or different materials. For example, the circuit board may be at least one of, but not limited to, an aluminum substrate, a copper substrate, a silver substrate, or a conductive alloy substrate. It should be understood that in the present embodiment, at least one of the circuit boards may be replaced by a non-metal substrate and a corresponding conductive layer disposed thereon. For example, in some examples, an equivalent replacement may be made with a substrate body having an insulating body and a composite substrate having corresponding conductor lines disposed within the substrate body. The substrate body may be made of a rigid material, such as but not limited to a phenolic paper laminated board, an epoxy paper laminated board, a polyester glass mat laminated board, an epoxy glass cloth laminated board, a BT resin board, or a glass board; the substrate body may also be made of a flexible material, such as but not limited to a polyester film, a polyimide film, or a fluorinated ethylene propylene film. In the present embodiment, a single-layer substrate may be used as the circuit board, or a composite-layer substrate including at least two sub-substrates may be used.

S2002: the light-emitting unit is arranged on the circuit board, and the electrodes of the miniature flip LED chip of the light-emitting unit are correspondingly and electrically connected with the bonding pads.

In this embodiment, the electrodes of the micro flip-chip LED chip and the pads can be electrically connected by, but not limited to, solder or conductive adhesive. When soldering is performed by solder in this example, a solder paste may be used, and a solder alloy containing lead, such as a tin-lead (Sn-Pb) alloy, a tin-lead-bismuth (Sn-Pb-Bi) alloy, a tin-lead-silver (Sn-Pb-Ag) alloy, or the like; lead-free solder alloys, such as tin-silver (Sn-Ag) alloys, tin-bismuth (Sn-Bi) alloys, tin-zinc (Sn-Zn) alloys, tin-antimony (Sn-Sb), tin-silver-copper (Sn-Ag-Cu) alloys, and tin-bismuth-silver (Sn-Bi-Ag) alloys, can also be used. In the case of bonding by a conductive adhesive in this example, the conductive adhesive used has both conductive and adhesive properties. When the conductive adhesive is classified as a conductive filler, the conductive adhesive used may include, but is not limited to, conductive silver adhesive, copper powder conductive adhesive, nickel carbon conductive adhesive, silver copper conductive adhesive, and the like.

For the convenience of understanding, the following description will be made with reference to a light emitting assembly as a backlight assembly, and with reference to several manufacturing examples of the backlight assembly.

Manufacturing an example I: as shown in fig. 21, the method includes:

s2101: a white light emitting unit 71 (the light emitting unit shown in fig. 6 is used in this example, and the description will be given by taking the light emitting unit emitting white light as an example) and a circuit board 6 are prepared, and the circuit board 6 in this example includes a substrate and solder paste printed on the substrate.

S2102: the white light emitting unit 71 is accurately attached to the substrate printed with the solder paste, and is molded after reflow soldering to obtain the backlight module. The backlight module manufactured by the example at least has the following advantages:

the large-visual-angle white light emitting unit is adopted, so that the maintenance is convenient, a QD film is not needed in the backlight module, and the cost is reduced;

the white light emitting unit is pasted on the substrate after light splitting, so that the light color is uniform;

the white light emitting unit contains less UVA and blue light components, the service life of the lens is long, and the reliability is better;

the white light emitting unit with large viewing angle is adopted, so that the distance between the light emitting units can be increased, the number of the light emitting units can be reduced, and the cost is further reduced.

Preparation example two: as shown in fig. 22, the method comprises the following steps:

s2201: a white light emitting unit 72 (the light emitting unit shown in fig. 13 is used in the present example, and the description will be given taking the light emitting unit emitting white light as an example) and a circuit board 6 are prepared, and the circuit board 6 in the present example includes a substrate and solder paste printed on the substrate.

S2202: the white light emitting unit 72 is accurately attached to the substrate printed with the solder paste, and is molded after reflow soldering to manufacture the backlight module. The backlight module manufactured by the example has the advantages that the light-emitting angle of the light-emitting unit is richer, and the display quality can be further improved; and the bonding area between the light-emitting unit and the substrate is larger, so that the bonding strength and the sealing property between the light-emitting unit and the substrate can be further improved, and the overall strength and the protective performance of the light-emitting unit are improved.

Preparation example three: as shown in fig. 23, the method comprises:

s2301: a white light emitting unit 73 (the light emitting unit shown in fig. 18 is used in the present example, and the description will be given taking the light emitting unit emitting white light as an example) and a circuit board 6 are prepared, and the circuit board 6 in the present example includes a substrate and solder paste printed on the substrate.

S2302: the white light emitting unit 73 is accurately attached to the substrate printed with the solder paste, and is molded after reflow soldering to manufacture the backlight module. The backlight module manufactured by the example has the advantages that the transfer efficiency of the light-emitting unit is higher, for example, the transfer efficiency can be nine times that of the backlight module manufactured by the first manufacturing example and the second manufacturing example, and the manufacturing cost can be further reduced; and the bonding area between the light-emitting unit and the substrate can be further improved, the bonding strength and the sealing property between the light-emitting unit and the substrate can be further improved, and the overall strength and the protective performance of the light-emitting unit are improved.

It should be understood that the light emitting assembly provided in this embodiment can be widely applied to electronic devices with display screens, such as mobile phones, notebook computers, tablet computers, intelligent wearing, eye protection products, vehicle terminals, advertisement display terminals, and the like, and also can be widely applied to various lighting devices for indoor lighting and outdoor lighting, and the details are not repeated here.

It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.

Claims

1. A method of fabricating a light emitting cell, comprising:

2. The method of claim 1, wherein filling each lens cavity with a liquid gel comprises:

3. The method of claim 1, wherein filling each lens cavity with a liquid gel comprises:

4. The method of claim 3, wherein removing the mold and the carrier substrate comprises:

removing the mold and then removing the bearing substrate;

5. The method of claim 4, wherein the cutting the extension layer according to the predetermined rule comprises at least one of:

6. The method of any of claims 1-5, wherein the carrier substrate is a glass substrate, and wherein providing the LED chip assembly comprises:

providing a glass substrate;

7. The method of fabricating a light emitting cell according to any of claims 1-5, wherein the providing a mold comprises:

8. The method of any of claims 1-5, wherein the light conversion particles comprise phosphor and/or quantum dot particles, and wherein the preparing the gel before filling the liquid gel into each of the lens cavities;

9. A light-emitting unit produced by the method for producing a light-emitting unit according to any one of claims 1 to 8.

10. A method of making a light emitting assembly, comprising:

disposing a light emitting cell fabricated by the light emitting cell fabrication method according to any one of claims 1 to 8 on the circuit board, and electrically connecting the electrodes of the micro flip LED chip of the light emitting cell to the pads in correspondence.