CN111326644A - A kind of LED device and its packaging method - Google Patents

Abstract

The application discloses an LED device, comprising a substrate; a circuit layer on the upper surface of the substrate; an LED chip connected to the circuit layer through a fixing part; A protective layer, and the protective layer is a protective layer superimposed by any one of a silicon dioxide layer, a silicon nitride layer, a silicon monoxide layer, and a silicon oxynitride layer, or any combination; an encapsulation part. The protective layer distributed on the upper surface of the circuit layer, the surface of the LED chip, and the surface of the fixing part not only has corrosion resistance and low water absorption, but also has very high stability, low shrinkage, high adhesion, and the packaging part. It has good compatibility, improves the sealing and moisture resistance of LED devices, and solves the problem of metal migration. In addition, the present application also provides an LED device packaging method with the above advantages.

Description

A kind of LED device and its packaging method

technical field

The present application relates to the field of LED technology, and in particular, to an LED device and a packaging method thereof.

Background technique

Light-emitting diodes, or LEDs for short, have the characteristics of energy saving, environmental protection, long life and small size, and are widely used in various fields such as indication, display, decoration, backlight, general lighting and urban night scenes.

At present, during the packaging process of LED devices, after the wire bonding process is completed, a layer of conformal paint or a siloxane waterproof layer is sprayed on the surface of the substrate, the surface of the LED chip and the surface of the coating layer, and then the molding process is performed. The welding wire uses thermal ultrasonic pressure resonance under high temperature to make the conductive wire and the electrode on the LED chip conductive, and the electrode on the LED chip will be damaged, because the density of the waterproof layer material is difficult to control and the adhesion is unstable etc., making the air tightness and moisture resistance of the LED device insufficient. When water vapor enters the LED device, the electrode after welding will undergo electrolysis under the action of water vapor and negative voltage to generate metal ions, that is, metal migration will occur, which will cause the electrode to fall off. LED device dead light.

Therefore, how to solve the above technical problems should be the focus of those skilled in the art.

SUMMARY OF THE INVENTION

The purpose of this application is to provide an LED device and a packaging method thereof, so as to solve the problem of metal migration and improve the air tightness and moisture resistance of the LED device.

In order to solve the above technical problems, the present application provides an LED device, including:

substrate;

a circuit layer on the upper surface of the substrate;

an LED chip connected to the circuit layer through a fixing part;

A protective layer distributed on the upper surface of the circuit layer, the surface of the LED chip, and the surface of the fixing portion, and the protective layer is a silicon dioxide layer, a silicon nitride layer, a silicon monoxide layer, and an oxynitride. Any one of the silicon layers or any combination of superimposed protective layers;

Packaging Department.

Optionally, the thickness of the protective layer ranges from 0.5 μm to 2 μm, inclusive.

Optionally, the LED chip is a chip with a PV layer on the upper surface.

Optionally, when the LED chip is a positive LED chip, it also includes:

a wire for electrically connecting the electrode of the LED chip and the circuit layer;

Correspondingly, the protective layer is distributed on the upper surface of the circuit layer, the surface of the LED chip, the surface of the fixing portion, and the surface of the wire.

Optionally, the encapsulation part is any one of a silicone encapsulation part, a modified epoxy resin encapsulation part, and an epoxy glue cake encapsulation part.

Optionally, the substrate is any one of a ceramic substrate, an aluminum nitride substrate, a BT plate, and a metal plate.

The present application also provides a method for packaging an LED device, comprising:

prepare the substrate;

making a circuit layer on the upper surface of the substrate;

Using the fixing part to fix the LED chip on the upper surface of the circuit layer;

A protective layer is formed on the upper surface of the circuit layer, the surface of the LED chip, and the surface of the fixing portion to obtain an LED device precursor;

The LED device precursor is compression-molded and packaged with an encapsulant to obtain an LED device.

Optionally, forming a protective layer on the upper surface of the circuit layer, the surface of the LED chip, the surface of the wire, and the surface of the fixing portion includes:

Using any one of physical vapor deposition method, chemical vapor deposition method, oxidation method, sol-gel method, liquid deposition method, the upper surface of the circuit layer, the surface of the LED chip, the surface of the wire . A protective layer is formed on the surface of the fixing part.

Optionally, when the LED chip is a positive LED chip, after the LED chip is fixed on the upper surface of the circuit layer by the fixing portion, the method further includes:

The electrodes of the LED chip and the circuit layer are welded with wires;

Correspondingly, forming a protective layer on the upper surface of the circuit layer, the surface of the LED chip, and the surface of the fixing portion includes:

A protective layer is formed on the upper surface of the circuit layer, the surface of the LED chip, the surface of the fixing portion, and the surface of the wire.

An LED device provided by the present application includes a substrate; a circuit layer located on the upper surface of the substrate; an LED chip connected to the circuit layer through a fixing part; distributed on the upper surface of the circuit layer, the LED A protective layer on the surface of the chip and the surface of the fixing portion, and the protective layer is any one of a silicon dioxide layer, a silicon nitride layer, a silicon monoxide layer, and a silicon oxynitride layer or any combination of superimposed protection layer; encapsulation part.

It can be seen that the LED device in this application not only includes a substrate, a circuit layer, a fixing part, an LED chip, and a packaging part, but also includes a protective layer distributed on the upper surface of the circuit layer, the surface of the LED chip, and the surface of the fixing part. It is a protective layer superimposed by any one or any combination of silicon dioxide layer, silicon nitride layer, silicon monoxide layer, silicon oxynitride layer, and the protective layer not only has corrosion resistance and low water absorption, but also has excellent High stability, low shrinkage, high adhesion, good compatibility with the packaging part, improve the sealing and moisture resistance of LED devices, solve the problem of metal migration, effectively protect the electrodes of LED chips, and improve the life of LED devices In addition, the protective layer can also protect the circuit layer from being polluted. In addition, the present application also provides an LED device packaging method with the above advantages.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present application or the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only For some embodiments of the present application, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of an LED device provided by an embodiment of the application;

FIG. 2 is a flowchart of a method for packaging an LED device provided by an embodiment of the present application;

FIG. 3 is a flowchart of another LED device packaging method provided by an embodiment of the present application;

FIG. 4 is a comparison result of a salt water test between the LED device in the prior art and the LED device in the present application.

Detailed ways

In order to make those skilled in the art better understand the solution of the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

Many specific details are set forth in the following description to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and those skilled in the art can do so without departing from the connotation of the present invention. Similar promotion, therefore, the present invention is not limited by the specific embodiments disclosed below.

As mentioned in the background section, in the prior art, the surface of the substrate, the surface of the LED chip and the surface of the coating are sprayed with a conformal paint or a siloxane waterproof layer, whose compactness is difficult to control and the adhesion is unstable, which makes the LED device The air tightness and moisture resistance are not enough. When water vapor enters the LED device, the electrode after welding will undergo electrolysis under the action of water vapor and negative voltage to generate metal ions, that is, metal migration occurs, which will cause the electrode to fall off and the LED device to die.

In view of this, the present application provides an LED device. Please refer to FIG. 1 , which is a schematic structural diagram of an LED device provided by an embodiment of the present application. The LED device includes:

substrate 1;

a circuit layer 2 located on the upper surface of the substrate 1;

The LED chip 3 connected to the circuit layer 2 through the fixing part 4;

The protective layer 6 is distributed on the upper surface of the circuit layer 2, the surface of the LED chip 3, and the surface of the fixing portion 4, and the protective layer 6 is a silicon dioxide layer, a silicon nitride layer, an oxide Any one of the silicon layer, the silicon oxynitride layer or the protective layer 6 superimposed in any combination;

package part 7 .

Preferably, the protective layer 6 is a single silicon dioxide layer, the single-layer protective layer 6 is easy to produce, requires low production equipment, and thus reduces the cost, and the silicon dioxide layer has high transparency, which will not affect the LED device. luminous properties are affected.

It should be pointed out that the lower surface of the substrate 1 is also distributed with a circuit layer 2 to achieve conduction. The type of the substrate 1 is not specifically limited in this application, for example, the substrate 1 is any one of a ceramic substrate 1 , an aluminum nitride substrate 1 , a BT (Bismaleimide Triazine) plate, and a metal plate. Similarly, the number of the LED chips 3 is not specifically limited in this application, and it depends on the situation.

The LED chip 3 includes a substrate, a buffer layer, an N-type gallium nitride layer, an active layer, an N-type gallium nitride layer, an ITO (Indium Tin Oxides, indium tin oxide) layer, and electrodes, which are sequentially stacked from bottom to top. It is well known to those skilled in the art and will not be described in detail here. Among them, the LED chip 3 has positive and negative electrodes.

It should be noted that the installation type of the LED chip 3 is not specifically limited in this embodiment. Depending on the situation, it can be either a front-mounted LED chip or a flip-chip LED chip; The size of the chip 3 is also not specifically limited, depending on the situation. When the LED chip 3 is a positive LED chip, it further includes: a wire 5 for electrically connecting the electrode of the LED chip 3 and the circuit layer 2; correspondingly, the protective layer 6 is distributed on the circuit layer 2 , the surface of the LED chip 3 , the surface of the fixing portion 4 , and the surface of the wire 5 . At this time, the fixing portion 4 may be insulating glue or conductive silver glue, wherein, when the fixing portion 4 is conductive silver glue, the number of wires 5 is only one. When the LED chip 3 is a flip-chip LED chip, there is no need to provide the wire 5, and the solder paste fixing part of the fixing part 4 is now. Further, the solder paste fixing part is a eutectic solder paste fixing part or a low temperature solder paste fixing part.

Optionally, the wire 5 is a conductive wire such as gold wire, copper wire, alloy copper wire, silver wire, aluminum wire or the like.

It should be noted that, in this embodiment, the encapsulation portion 7 is not specifically limited, and can be set by itself. For example, the encapsulation part 7 is any one of a silicone encapsulation part, a modified epoxy resin encapsulation part, an epoxy glue cake encapsulation part, and an epoxy glue.

In addition to the substrate 1 , the circuit layer 2 , the fixing part 4 , the LED chip 3 , and the packaging part 7 , the LED device in this application also includes the upper surface of the circuit layer 2 , the surface of the LED chip 3 , and the surface of the fixing part 4 . The protective layer 6, the protective layer 6 is any one of the silicon dioxide layer, the silicon nitride layer, the silicon monoxide layer, the silicon oxynitride layer or the protective layer 6 superimposed in any combination, the protective layer 6 not only has corrosion resistance It also has very high stability, low shrinkage, high adhesion, good compatibility with the packaging part 7, improves the sealing and moisture resistance of LED devices, solves the problem of metal migration, and effectively The electrodes of the LED chip 3 are protected, and the lifespan of the LED device is improved. In addition, the protection layer 6 can also protect the circuit layer 2 from being polluted.

Preferably, in an embodiment of the present application, the thickness of the protective layer 6 ranges from 0.5 micrometers to 2 micrometers, including the endpoint value, so as to avoid the thickness of the protective layer 6 being too thin. The electrodes have insufficient moisture-proof protection and poor resistance to metal migration. At the same time, it avoids that the thickness of the protective layer 6 is too thick, wastes raw materials, increases costs, and generates additional stress to the electrodes of the LED chip 3 .

On the basis of any of the above embodiments, in an embodiment of the present application, the LED chip 3 is an LED chip 3 having a PV (passivation, passivation) layer on the upper surface. Specifically, the PV layer is located on the surface of the ITO layer and the electrode of the LED chip 3, which can further enhance the air tightness of the LED device and avoid contamination of the ITO layer and the electrode by contaminants.

Referring to FIG. 2, the present application further provides a method for packaging an LED device, the method comprising:

Step S101: Prepare the substrate.

In this embodiment, the type of the substrate to be prepared is not limited, and may be any one of a ceramic substrate, a mirror-surface aluminum substrate, a BT plate, and a metal plate.

Step S102 : forming a circuit layer on the upper surface of the substrate.

Step S103 : using the fixing part to fix the LED chip on the upper surface of the circuit layer.

Specifically, a die-bonding process is used to fix the LED chip on the upper surface of the circuit layer.

Step S104 : forming a protective layer on the upper surface of the circuit layer, the surface of the LED chip, and the surface of the fixing portion to obtain an LED device precursor.

Preferably, the thickness of the protective layer is controlled between 0.5 micrometers and 2 micrometers, including the endpoint value, to avoid the thickness of the protective layer being too thin, insufficient protection of the electrode moisture resistance of the LED chip after wire bonding, and poor resistance to metal migration, while avoiding protection. If the thickness of the layer is too low, it wastes raw materials, increases the cost, and also generates additional stress to the electrodes of the LED chip.

Optionally, using any one of physical vapor deposition, chemical vapor deposition, oxidation, sol-gel, and liquid deposition, the upper surface of the circuit layer, the surface of the LED chip, the A protective layer is formed on the surface of the wire and the surface of the fixing portion. Wherein, the temperature is controlled between 100°C and 180°C when making the protective layer.

Further, chemical vapor deposition methods include atmospheric pressure chemical vapor deposition methods, low pressure chemical vapor deposition methods, plasma enhanced chemical vapor deposition methods, photochemical vapor deposition methods, and the like.

Step S105 : performing compression molding on the LED device precursor with an encapsulant to obtain an LED device.

The encapsulant can be any one of transparent liquid silica gel, modified epoxy resin, solid epoxy cake, and liquid epoxy. It is well known to those skilled in the art and will not be described in detail. Here, the liquid epoxy adhesive is taken as an example for specific description. After mixing A and B evenly, use a vacuum defoaming machine to stir in sections for 3 min to 8 min, and degas for 1 min to 4 min. Inject into 120℃～140℃ mold for high temperature molding to obtain LED device.

It should be pointed out that there are generally a large number of LED chips on the substrate, and a cutting process is required after lamination and packaging. After cutting, the performance of the LED devices is tested and packaged.

Referring to FIG. 3, the present application further provides another method for packaging an LED device. When the LED chip is a positive LED chip, the method includes:

Step S201: Prepare the substrate.

Step S202 : forming a circuit layer on the upper surface of the substrate.

Step S203 : using the fixing part to fix the LED chip on the upper surface of the circuit layer.

Step S204: Use wires to weld the electrodes of the LED chip and the circuit layer.

Specifically, when the fixing part is insulating glue, the positive electrode of the LED chip is electrically connected to the circuit layer through the conductive wire, and the negative electrode of the LED chip is electrically connected to the circuit layer through the conductive wire; when the fixing part is conductive silver When glue is applied, a conductive wire can be used to electrically connect the positive electrode or the negative electrode of the LED chip to the circuit layer.

Step S205 : forming a protective layer on the upper surface of the circuit layer, the surface of the LED chip, the surface of the fixing portion, and the surface of the wire to obtain an LED device precursor.

Step S206 : performing compression molding and packaging on the LED device precursor with an encapsulant to obtain an LED device.

In order to verify the performance of the LED device in this application, the results of experimental comparison with the LED device in the prior art are as follows.

1. Reverse pressure verification under high temperature and high humidity environment:

Experimental conditions: 85℃/85%RH, V _F =-10V;

LED devices in the prior art: 1000H light decay -12%;

LED device in this application: 1000H light decay -5%.

2. Salt water experiment:

Experimental conditions: saturated concentration NaCl solution, temperature 50 ℃, point measurement every 24h;

LED device experiment quantity: 300pcs;

Please refer to FIG. 4 for the comparison result between the LED device in the prior art and the LED device in the present application.

3. The light board is lit to refresh the temperature and humidity cycle experiment:

3.1 Number of experiments:

The number of LED devices in the prior art is 46000pcs and 2 light boards;

The number of LED devices in this application is 46000pcs and 2 light boards;

3.2 Experimental conditions:

Step 1. LED device patch

Step 2.Reflow: (260℃±5℃) 3 times

Step 3.TS: -5℃/0%OFF 2H→25℃/95%ON 2H→-5℃/0%OFF2H; 10 rounds in total.

Step 4. HTHH dynamic: temperature 85℃; humidity 85%RH; time 168H;

3.3 Statistics of experimental results:

LED device light board in the prior art: 6pcs dead light, 2pcs of which is migration;

The LED device light board in this application: no abnormality such as dead light.

It can be seen from the above experimental results that, compared with the LED device in the prior art, the LED device in the present application is significantly improved in sealing performance and moisture resistance, and the metal migration phenomenon is significantly improved.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts of the various embodiments may be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

The LED device and the packaging method thereof provided by the present application have been introduced in detail above. Specific examples are used herein to illustrate the principles and implementations of the present application, and the descriptions of the above embodiments are only used to help understand the methods and core ideas of the present application. It should be pointed out that for those of ordinary skill in the art, without departing from the principles of the present application, several improvements and modifications can also be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims (9)

1. A LED device, characterized in that, comprising: substrate; a circuit layer on the upper surface of the substrate; an LED chip connected to the circuit layer through a fixing part; A protective layer distributed on the upper surface of the circuit layer, the surface of the LED chip, and the surface of the fixing portion, and the protective layer is a silicon dioxide layer, a silicon nitride layer, a silicon monoxide layer, and an oxynitride. Any one of the silicon layers or any combination of superimposed protective layers; Packaging Department. 2 . The LED device of claim 1 , wherein the thickness of the protective layer ranges from 0.5 μm to 2 μm, inclusive. 3 . 3. The LED device according to claim 2, wherein the LED chip is a chip with a PV layer on the upper surface. 4. The LED device according to any one of claims 1 to 3, characterized in that, when the LED chip is a positive LED chip, further comprising: a wire for electrically connecting the electrode of the LED chip and the circuit layer; Correspondingly, the protective layer is distributed on the upper surface of the circuit layer, the surface of the LED chip, the surface of the fixing portion, and the surface of the wire. 5 . The LED device according to claim 4 , wherein the encapsulation part is any one of a silicone encapsulation part, a modified epoxy resin encapsulation part, and an epoxy glue cake encapsulation part. 6 . 6. The LED device according to claim 5, wherein the substrate is any one of a ceramic substrate, an aluminum nitride substrate, a BT plate, and a metal plate. 7. A method for packaging an LED device, comprising: prepare the substrate; making a circuit layer on the upper surface of the substrate; Using the fixing part to fix the LED chip on the upper surface of the circuit layer; A protective layer is formed on the upper surface of the circuit layer, the surface of the LED chip, and the surface of the fixing portion to obtain an LED device precursor; The LED device precursor is compression-molded and packaged with an encapsulant to obtain an LED device. 8 . The LED device packaging method according to claim 7 , wherein the forming a protective layer on the upper surface of the circuit layer, the surface of the LED chip, and the surface of the fixing portion comprises: 8 . Using any one of physical vapor deposition method, chemical vapor deposition method, oxidation method, sol-gel method, liquid deposition method, the upper surface of the circuit layer, the surface of the LED chip, the surface of the fixed part Make a protective layer on the surface. 9 . The LED device packaging method according to claim 8 , wherein when the LED chip is a positive LED chip, after the LED chip is fixed on the upper surface of the circuit layer by the fixing portion, the LED chip is further mounted on the circuit layer. 10 . include: Use wires to weld the electrodes of the LED chip and the circuit layer; Correspondingly, forming a protective layer on the upper surface of the circuit layer, the surface of the LED chip, and the surface of the fixing portion includes: A protective layer is formed on the upper surface of the circuit layer, the surface of the LED chip, the surface of the fixing portion, and the surface of the wire.

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