CN111668203A

CN111668203A - A kind of packaging method of high-power LED device and LED device thereof

Info

Publication number: CN111668203A
Application number: CN202010456522.8A
Authority: CN
Inventors: 张智聪; 孙钱
Original assignee: Suzhou Institute of Nano Tech and Nano Bionics of CAS
Current assignee: Suzhou Institute of Nano Tech and Nano Bionics of CAS
Priority date: 2020-05-26
Filing date: 2020-05-26
Publication date: 2020-09-15

Abstract

The invention relates to a packaging method for a high-power LED device, comprising the following steps: A. arranging an LED chip on a substrate; B. covering a lens ring on the substrate; C. filling the wafer with glue on the lens ring Bottom; D. Fix the optical glass on the top of the lens ring; E. Set an atomized layer on the light-emitting surface of the optical glass; F. Set a phosphor structure layer on the surface of the atomized layer. Correspondingly, the present invention also provides an LED device based on the packaging method. The packaging method of the high-power LED device provided by the invention improves the reflection efficiency of the bottom of the substrate, reduces the absorption of light by the substrate, thereby improves the light extraction efficiency, improves the adhesion of the phosphor structure layer, and prevents the fluorescent glue layer from falling off and fluorescent light. Delamination occurs between the adhesive layer and the optical glass.

Description

Packaging method of high-power LED device and LED device thereof

Technical Field

The invention relates to the technical field of LED packaging, in particular to a packaging method of a high-power LED device and the LED device.

Background

The high-power LED device is widely applied due to the advantages of high brightness and the like, the high-power LED device requires high power, small volume, high color rendering index, high light efficiency and the like, the traditional high-power LED device has nonuniform light emission, and fluorescent powder is directly filled, so that the concentration of the fluorescent powder at each angle is inconsistent, light spots exist, and the high-power LED generates a large amount of heat during working, so that the fluorescent powder generates phenomena such as attenuation, chromaticity drift and the like under high-temperature aerobic annular conditions.

The problem of facula can be solved to a certain extent to current remote excitation phosphor powder's scheme, but phosphor powder is direct attached to on the glass piece, and the heat that produces in the work of LED chip need distribute away through base plate and glass piece, and the heat on the glass piece can transmit to the phosphor layer on, and the temperature on phosphor layer reaches certain degree and will send out yellow and black, influences light-emitting efficiency and facula effect during the LED.

On the other hand, because the temperature of the glass sheet and the fluorescent powder layer is higher during operation, and the non-operating state is recovered to the normal temperature state, the difference between the expansion coefficients of the fluorescent powder and the glass sheet is larger, the fluorescent powder layer is easy to separate from the glass sheet or peel off during multiple expansion and contraction processes, and the service life of the fluorescent powder layer is influenced.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a packaging method of a high-power LED device, which has high heat dissipation efficiency, relieves the problem of blackening of fluorescent powder and increases the adhesive force of a fluorescent powder layer.

The invention also provides the LED device manufactured by the packaging method, which has high heat dissipation efficiency and high reliability and ensures the service life of the LED device.

In order to solve the technical problem, the invention provides a packaging method of a high-power LED device, which comprises the following steps:

A. arranging an LED wafer on a substrate;

B. covering a lens ring on a substrate, wherein the LED wafer is positioned in the lens ring;

C. filling wafer glue at the bottom of the lens ring, wherein the height of the wafer glue is smaller than that of the LED wafer;

D. fixing an optical glass on the top of the lens ring;

E. arranging an atomizing layer on the light-emitting surface of the optical glass;

specifically, silica gel is filled into a silica gel container of a machine table, the machine table forms the silica gel into a fog drop shape through high-pressure air, the fog drop-shaped silica gel is sprayed on the surface of the optical glass by a nozzle to form an atomizing layer, and therefore tiny bulges are formed on the surface of the optical glass;

in the atomization process, the pressure in the machine table is 1-5 atmospheric pressures, the nozzle moves back and forth above the optical glass at the moving speed of 10-50cm/s for 1-30 seconds;

F. and a fluorescent powder structure layer is arranged on the surface of the atomization layer.

Preferably, the wafer glue is a mixture of titanium dioxide and silica gel, and the weight ratio of the titanium dioxide to the silica gel is 0.1:1-0.8: 1.

Preferably, the light incident surface and the light emergent surface of the optical glass are planes, and the thickness of the light incident surface and the light emergent surface of the optical glass is 0.1-10 mm; or,

the light incident surface and/or the light emergent surface of the optical glass are cambered surfaces, and the maximum thickness of the optical glass is 0.5-20 mm.

Preferably, the thickness of the fluorescent powder structure layer is 0.03-3mm, the fluorescent powder structure layer is formed by mixing fluorescent powder and silica gel, and the particle diameter of the fluorescent powder is 5-30 μm;

the weight of the fluorescent powder accounts for 5-95% of the total weight of the fluorescent powder structure layer.

An LED device packaged by the packaging method of the high-power LED device comprises a substrate, an LED wafer arranged on the substrate, a lens ring covered on the substrate, wafer glue filled at the bottom of the lens ring, optical glass arranged at the top of the lens ring, an atomizing layer arranged on the optical glass and a fluorescent powder structure layer arranged on the atomizing layer;

the wafer glue is positioned around the LED wafer, and the height of the wafer glue is smaller than that of the LED wafer;

the optical glass is fixed on the lens ring through packaging glue.

Preferably, the substrate is a ceramic substrate, and a reflective layer is further disposed on the upper surface of the substrate.

Preferably, the LED chip is a blue light chip or an ultraviolet chip;

the LED wafer is an LED wafer with a vertical structure or an LED wafer with a flip-chip structure.

Preferably, the lens ring is made of copper or aluminum alloy, and the inner surface of the lens ring is provided with a lens reflecting layer.

Preferably, the inner surface of the top of the lens ring is further provided with a step structure, and the step structure and the lens ring form a concentric circle structure;

the optical glass is fixed on the step structure through packaging glue.

Preferably, the packaging adhesive is silica gel.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the packaging method of the high-power LED device, the wafer adhesive is arranged at the bottom of the substrate, so that the reflection efficiency of the bottom of the substrate is improved, and the absorption of the substrate to light is reduced, so that the light emitting efficiency is improved; and finally, the thermal conductivity coefficient of the silica gel is higher, so that heat is quickly dissipated through the atomizing layer, the fluorescent powder is prevented from blackening and yellowing at high temperature, and the reliability of the fluorescent powder structure layer is improved.

2. According to the LED device based on the packaging method, the wafer glue is arranged, so that the reflection efficiency of the bottom of the substrate is improved, the absorption of the substrate to light is reduced, the light emitting efficiency is improved, the adhesive force of the fluorescent powder structure layer is improved through the arrangement of the atomizing layer, and the phenomena that the fluorescent glue layer falls off and the fluorescent glue layer and the optical glass are layered are prevented. Thirdly, through the arrangement of the atomization layer, the expansion coefficient difference between the optical glass and the fluorescent powder structure layer is reduced, the adhesive force is further improved, and the service life of the LED device is prolonged; and finally, the thermal conductivity coefficient of the silica gel is higher, so that heat is quickly dissipated through the atomizing layer, the fluorescent powder is prevented from blackening and yellowing at high temperature, and the reliability of the fluorescent powder structure layer is improved.

Drawings

FIG. 1 is a flow chart of a method for packaging a high power LED device according to the present invention;

fig. 2 is a schematic structural diagram of an LED device provided by the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and preferred embodiments.

Fig. 1 is a flow chart of a packaging method of a high-power LED device according to the present invention, which is described in detail below with reference to the accompanying drawings.

As shown in fig. 1 and 2, the method for packaging a high power LED device comprises the following steps:

A. the LED chip 2 is arranged on the substrate 1, wherein the number of the LED chips 2 is one or more, the LED chips are arranged on the upper surface of the substrate 1, and the LED chips are blue light chips or ultraviolet chips, which can be LED chips with a vertical structure or LED chips with a flip-chip structure.

The substrate 1 is a ceramic substrate, specifically Al₂O₃The ceramic substrate, AlN ceramic substrate, or BeO ceramic substrate may be a metal substrate in other embodiments, and is not limited to this example.

In order to improve the reflection efficiency of the substrate 1 and improve the light extraction efficiency, the upper surface of the substrate 1 is further provided with a reflective layer, the reflective layer can be obtained by polishing, can be coated with a reflective coating, and can be further coated with a metal layer (such as a silver coating layer, an aluminum coating layer and the like).

B. The lens ring 3 is covered on the substrate 1 for mixing light, the LED chip 2 is located inside the lens ring 3, so that light emitted by the LED chip 2 is reflected and mixed for multiple times inside the lens ring 3, and light emitted by the LED device is ensured to be uniform, and specifically, the lens ring 3 is made of copper or aluminum alloy (such as Al-Si alloy and Al-Si-Mg alloy).

In order to facilitate the installation of the light emitting structure, a step structure is further arranged on the inner surface of the top of the lens ring 3, and the step structure and the lens ring 3 form a concentric circle structure.

In order to improve the reflection efficiency, the inner surface of the lens ring 3 is provided with a lens reflective layer, which may be obtained by polishing, or may be coated with a reflective coating, or may be coated with a metal layer (such as a silver coating layer, an aluminum coating layer, etc.), but is not limited to this embodiment.

It should be noted here that step B may be provided before step a as long as the placement of the LED chip is not affected.

C. And filling wafer glue 4 at the bottom of the lens ring 3, wherein the height of the wafer glue 4 is less than that of the LED wafer 2.

And filling wafer glue 4 at the bottom of the substrate 1 by a dispensing process or other processes, wherein the height of the wafer glue 4 is smaller than that of the LED wafer 2, so that the reflectivity of the substrate 1 is improved, the absorption of the substrate to light is reduced, and the brightness of the LED device is improved.

Specifically, the wafer glue 4 is a mixture of titanium dioxide and silica gel, and the weight ratio of the titanium dioxide to the silica gel is 0.1:1-0.8:1, specifically 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, and 0.8: 1.

It should be noted that if the ratio is too low, the amount of titanium dioxide is too small, which results in an insignificant light reflection effect and does not effectively prevent the light absorption around the wafer, and if the ratio is too high, the amount of titanium dioxide is too high, which results in the wafer glue not flowing.

D. And the optical glass 5 is fixed on the top of the lens ring 3, and the optical glass 5 is fixed on the step structure through the packaging adhesive 8, so that the light emitted by the LED wafer 2 can be transmitted out through the optical glass 5. The light emergent surface and the light incident surface of the optical glass 5 can be of a plane structure or an arc surface structure, and are specifically arranged according to actual needs. In this embodiment, when the light incident surface and the light emitting surface of the optical glass 5 are planes, the thickness thereof is 0.1 to 10mm, and when the light incident surface and/or the light emitting surface of the optical glass are arcs, the maximum thickness thereof is 0.5 to 20 mm.

Here, if the thickness of the optical glass is too low, the optical glass is too thin and easily broken, and the yield of mass production is low, which is limited by the threshold of mass production technology. If the thickness is too high, the light emitted from the wafer cannot be reflected, resulting in low light-emitting efficiency.

The encapsulation adhesive 8 may be silica gel, epoxy resin, or other encapsulation adhesive.

E. Set up atomizing layer 6 on optical glass 5's the plain noodles, it is concrete, pack into silica gel in the silica gel container of board with silica gel, the board passes through high-pressure air and forms the fog drop form with silica gel, and the silica gel of fog drop form is spouted by the nozzle on optical glass's surface forms one deck atomizing layer for optical glass surface forms small arch, increases the surface area, thereby increases surface adhesion, and in the atomizing process, the air pressure in the board is 1-5 atmospheric pressure, and the nozzle is in optical glass's top round trip movement, and the speed of moving is 10-50cm/s, and the time is 1-30 seconds.

It should be noted that the air pressure in the machine is too low, so that the silica gel cannot be sprayed out. The pressure is too high, so that the silica gel is sprayed out too thinly and cannot achieve the specified effect.

The machine is a silica gel spraying device, and can also be other spraying devices, and is not limited to this embodiment.

F. The surface of the atomizing layer 6 is provided with a fluorescent powder structure layer 7, the fluorescent layer structure layer 7 can be a fluorescent film, or fluorescent powder coating is carried out on the surface of the atomizing layer through a powder spraying process, wherein the thickness of the fluorescent powder structure layer is 0.03-3mm, specifically 0.5mm, 1mm, 1.5mm, 2mm and 2.5 mm. The particle diameter of the fluorescent powder is 5-30 μm, specifically 10 μm, 15 μm, 20 μm, and 25 μm. The fluorescent powder is formed by mixing fluorescent powder and silica gel, and the weight of the fluorescent powder accounts for 5-95% of the total weight of the fluorescent powder structure layer.

It should be noted here that the phosphor particles are too fine, and the efficiency of exciting the phosphor by the LED chip is low; the thickness of the fluorescent powder layer is too thin, and the LED light-emitting efficiency is high. The fluorescent powder particles are too large, and the LED wafer has high luminous efficiency of exciting the fluorescent powder; the fluorescent powder layer is too thick, which affects the light emitting efficiency of the LED.

It should be noted that, steps E and F may be set before step D, that is, after the matte layer and the phosphor structure layer are set on the optical glass, the optical glass is mounted on the lens ring, and the present invention is not limited to this embodiment.

According to the packaging method of the high-power LED device, the wafer adhesive 4 is arranged at the bottom of the substrate 1, so that the reflection efficiency of the bottom of the substrate 1 is improved, and the absorption of the substrate to light is reduced, so that the light emitting efficiency is improved, secondly, the atomizing layer is arranged between the fluorescent powder structural layer 7 and the optical glass, so that the adhesive force of the fluorescent powder structural layer 7 is improved, the phenomena that the fluorescent powder layer falls off and the fluorescent powder layer and the optical glass are layered are prevented, thirdly, the expansion coefficient difference between the optical glass 5 and the fluorescent powder structural layer 7 is reduced through the arrangement of the atomizing layer 6, the adhesive force is further improved, and the service life of the LED device is prolonged; and finally, the thermal conductivity coefficient of the silica gel is higher, so that heat is quickly dissipated through the atomizing layer, the fluorescent powder is prevented from blackening and yellowing at high temperature, and the reliability of the fluorescent powder structure layer is improved.

Correspondingly, as shown in fig. 2, the present invention further provides an LED device based on the above packaging method, specifically:

as shown in fig. 2, an LED device based on the packaging method of the high power LED device includes a substrate 1, an LED chip 2 disposed on the substrate 1, a lens ring 3 covering the substrate 1, a chip adhesive 4 filled at the bottom of the lens ring 3, an optical glass 5 disposed at the top of the lens ring 3, an atomizing layer 6 disposed on the optical glass 5, and a phosphor structure layer 7 disposed on the atomizing layer 6;

the wafer glue 4 is positioned around the LED wafer 2, and the height of the wafer glue 4 is smaller than that of the LED wafer 2;

the optical glass 5 is fixed on the lens ring 3 through a packaging adhesive 8.

The substrate 1 is used for mounting an LED chip, and is a ceramic substrate, specifically Al₂O₃The ceramic substrate, AlN ceramic substrate, or BeO ceramic substrate may be a metal substrate in other embodiments, and is not limited to this example.

The LED wafer 2 is arranged on the substrate 1 and used for providing a light source, and the light source is a blue light wafer or an ultraviolet wafer, which can be an LED wafer with a vertical structure or an LED wafer with a flip structure.

The lens ring 3 is covered on the substrate 1 and used for realizing light mixing, the LED chip 2 is located inside the lens ring 3, so that light emitted by the LED chip 2 is reflected and mixed for multiple times inside the lens ring 3, and light emitted by the LED device is ensured to be uniform, and specifically, the lens ring 3 is made of copper or aluminum alloy (such as Al-Si alloy and Al-Si-Mg alloy).

In order to facilitate the installation of the optical glass 5, the inner surface of the top of the lens ring 3 is further provided with a step structure, and the step structure and the lens ring 3 form a concentric circle structure.

The wafer glue 4 is filled at the bottom of the lens ring 3, and the height of the wafer glue 4 is smaller than that of the LED wafer 2, so that the light emitted by the LED wafer 2 can reach the inside of the lens ring 3 to be mixed, and the light emitting efficiency is ensured.

The optical glass 5 is arranged at the top of the lens ring 3 and fixed on the step structure through the packaging adhesive 8, so that light emitted by the LED wafer 2 can be transmitted out through the optical glass 5.

The light emergent surface and the light incident surface of the optical glass 5 can be in a plane structure or an arc surface structure, and are specifically arranged according to actual needs. In this embodiment, when the light incident surface and the light emitting surface of the optical glass 5 are planes, the thickness thereof is 0.1 to 10mm, and when the light incident surface and/or the light emitting surface of the optical glass 5 are arcs, the maximum thickness thereof is 0.5 to 20 mm.

The atomizing layer 6 is arranged on the optical glass 5 and used for improving the adhesive force of the fluorescent powder structure layer 7 and improving the reliability of the LED device. In this embodiment, the atomizing layer 6 is made of silica gel.

The fluorescent powder structure layer 7 is arranged on the surface of the atomization layer 6 and can be a fluorescent film or a mixture of fluorescent powder and silica gel. The thickness of the fluorescent powder structural layer 7 is 0.03-3mm, and the diameter of fluorescent powder particles is 5-30 μm.

According to the LED device based on the packaging method, the reflection efficiency of the bottom of the substrate 1 is improved through the arrangement of the wafer adhesive 4, the absorption of the substrate to light is reduced, so that the light emitting efficiency is improved, the adhesive force of the fluorescent powder structure layer 7 is improved through the arrangement of the atomizing layer 6, the phenomena that the fluorescent adhesive layer falls off and the fluorescent adhesive layer and the optical glass are layered are prevented, and the expansion coefficient difference between the optical glass 5 and the fluorescent powder structure layer 7 is reduced through the arrangement of the atomizing layer 6, so that the adhesive force is further improved, and the service life of the LED device is prolonged; finally, the thermal conductivity coefficient of the silica gel is high, so that heat can be quickly dissipated through the atomizing layer 6, the fluorescent powder is prevented from being blackened and yellowed at high temperature, and the reliability of the fluorescent powder structure layer 7 is improved.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims

1. a packaging method of high-power LED device, is characterized in that, comprises the following steps:

A. Set the LED chip on the substrate;

B. The lens ring is covered on the substrate, and the LED chip is located inside the lens ring;

C. Fill the bottom of the lens ring with wafer glue, and the height of the wafer glue is less than the height of the LED chip;

D. Fix the optical glass on the top of the lens ring;

E. An atomized layer is arranged on the light-emitting surface of the optical glass;

Specifically, the silica gel is put into the silica gel container of the machine, the machine forms the silica gel into droplets through high-pressure air, and the droplet-shaped silica gel is sprayed on the surface of the optical glass by the nozzle to form an atomized layer, so that an atomized layer is formed. The surface of the optical glass is formed with tiny protrusions;

During the atomization process, the pressure in the machine is 1-5 atmospheres, the nozzle moves back and forth above the optical glass, the moving speed is 10-50cm/s, and the time is 1-30 seconds;

F. A phosphor structure layer is arranged on the surface of the atomized layer.

2 . The packaging method of a high-power LED device according to claim 1 , wherein the wafer glue is a mixture of titanium dioxide and silica gel, and the weight ratio of the titanium dioxide and the silica gel is 0.1:1-0.8:1. 3 .

3 . The packaging method for a high-power LED device according to claim 1 , wherein the light incident surface and the light exit surface of the optical glass are planes, and the thickness thereof is 0.1-10 mm; or, 3 .

The light incident surface and/or the light exit surface of the optical glass are arc surfaces, and the maximum thickness thereof is 0.5-20 mm.

4. The encapsulation method of a high-power LED device according to claim 1, wherein the thickness of the phosphor structure layer is 0.03-3 mm, which is formed by mixing phosphor and silica gel, and the particle diameter of the phosphor is 5 mm. -30μm;

The weight of the phosphor accounts for 5-95% of the total weight of the phosphor structure layer.

5. An LED device packaged by the packaging method for a high-power LED device according to any one of claims 1-4, characterized in that it comprises a substrate, an LED chip arranged on the The lens ring on the substrate, the wafer glue filled on the bottom of the lens ring, the optical glass on the top of the lens ring, the fogging layer on the optical glass, and the fluorescent light on the fogging layer powder structure layer;

The chip glue is located around the LED chip, and its height is smaller than the height of the LED chip;

The optical glass is fixed on the lens ring through an encapsulant.

6 . The LED device according to claim 5 , wherein the substrate is a ceramic substrate, and the upper surface is further provided with a light-reflecting layer. 7 .

7. The LED device according to claim 5, wherein the LED chip is a blue light chip or an ultraviolet chip;

The LED chip is a vertical structure LED chip or a flip-chip structure LED chip.

8 . The LED device according to claim 5 , wherein the lens ring is made of copper or aluminum alloy, and the inner surface of the lens ring is provided with a lens reflective layer. 9 .

9 . The LED device according to claim 5 , wherein the top inner surface of the lens ring is further provided with a step structure, and the step structure and the lens ring form a concentric structure; 10 .

The optical glass is fixed on the step structure by an encapsulant.

10 . The LED device according to claim 5 , wherein the encapsulant is silica gel. 11 .