CN108461616B - Packaging method of thermoelectric separation heat dissipation structure for high-power L ED - Google Patents

Abstract

The invention discloses a packaging method of a thermoelectric separation heat dissipation structure for a high-power L ED, which comprises a heat dissipation substrate, an insulating layer and a copper foil layer which are sequentially arranged on the heat dissipation substrate, wherein a notch A is formed in the insulating layer and a notch B is formed in the copper foil layer through a milling process, a L ED packaging structure is arranged in the notch A and the notch B which are matched with the L ED packaging structure, a L ED base is connected with the heat dissipation substrate, and a L ED chip arranged on the L ED base is electrically connected with the copper foil layer through an electrode.

Description

A kind of packaging method of thermoelectric separation heat dissipation structure for high-power LED

technical field

The invention relates to the technical field of heat dissipation of high-power LEDs, in particular to a packaging method of a thermoelectric separation heat dissipation structure for high-power LEDs.

Background technique

With the rapid development of science and technology, people have higher and higher requirements for the luminous power of street lighting. As an excellent semiconductor optoelectronic device, LED has become an ideal solid-state energy-saving lighting source for a new generation due to its advantages of small size, low power consumption, long service life and environmental protection. With the development of LEDs to high light intensity and high power, the problem of heat dissipation of LEDs has become increasingly prominent. The problem of heat dissipation affects the light output characteristics of the LED and the life of the device, and is a key issue in high-power LED packaging. If the heat dissipation of the package is poor, the temperature of the chip will rise, resulting in uneven stress distribution, shortened life, and reduced phosphor conversion efficiency, resulting in a decrease in chip light extraction efficiency.

At present, the problem of heat dissipation is the main factor limiting the development of LEDs. Narendran et al. have confirmed through experiments that the LED lifespan decreases exponentially with the increase of the LED chip junction temperature, and it may fail at any time when the extreme temperature is exceeded. Therefore, the problem of heat dissipation is a major technical bottleneck faced by the entire high-power LED industry.

In the prior art, high-power LED lamp beads are directly packaged on traditional aluminum-based copper clad boards (copper foil, insulating layer and aluminum plate in sequence from top to bottom). Low heat dissipation efficiency and poor heat dissipation will increase the temperature of the chip, cause uneven stress distribution, shorten the lifespan, and decrease the conversion efficiency of phosphors, resulting in a decrease in the light extraction efficiency of the chip.

Therefore, in view of the defects of the prior art, it is necessary to propose a technical solution to solve the technical problems existing in the prior art.

SUMMARY OF THE INVENTION

In view of this, it is indeed necessary to provide a packaging method for a high-power LED with a thermoelectric separation heat dissipation structure with good heat dissipation performance, thereby greatly reducing the thermal resistance of the high-power LED and solving the bottleneck problem of heat dissipation of the high-power LED.

In order to solve the technical problems existing in the prior art, the technical scheme of the present invention is as follows:

A packaging method for a high-power LED with a thermoelectric separation heat dissipation structure, characterized in that it comprises the following steps:

A composite heat-dissipating substrate is formed by plating copper on the upper and lower sides of the double-sided anodized aluminum plate;

The upper surface of the composite heat dissipation substrate is sequentially covered with an insulating layer and a copper foil layer and pressed together to form a copper clad laminate;

On the upper surface of the CCL, the copper foil and insulating layer corresponding to the LED base are milled off to form a gap A and a gap B;

A copper layer is arranged in the insulating layer position milled from the notch A;

The LED chip is placed on the LED base to form an LED package structure, and the base is placed on the copper clad plate prepared in the above steps to directly connect the base to the composite heat dissipation substrate, thereby forming a thermoelectric separation heat dissipation structure.

As a preferred technical solution, an insulating layer and a copper foil layer are sequentially arranged on the composite heat dissipation base, a part of the insulating layer material is removed by a milling process to expose the heat dissipation substrate and a gap A is formed, and a milling process is performed on both sides of the gap A by a milling process. Removing part of the copper foil layer material exposes the insulating layer and forms a gap B.

By adopting the above technical solution, through the structural improvement, the LED package structure can be directly fitted with the gap A and the gap B. Since the LED heat dissipation base is directly connected to the heat dissipation substrate, the heat generated by the LED chip can be directly conducted to the heat dissipation substrate On the top, the high thermal resistance insulating layer in the traditional heat dissipation substrate is avoided, and the thermal resistance of the high-power LED is greatly reduced.

As a preferred technical solution, the LED package structure is arranged in the matching gap A and gap B, so that the LED base is physically connected to the composite heat dissipation substrate, and the LED chip disposed on the LED base is electrically connected to the copper foil layer through electrodes. ;

The composite heat dissipation substrate includes a composite aluminum layer and a composite copper layer disposed on both sides of the composite aluminum layer.

As a preferred technical solution, the copper layer and the insulating layer have the same thickness and are connected to the LED base by welding.

In the above technical solution, a copper layer with the same thickness as the insulating layer is electroplated on the gap A where the insulating layer is milled off. This copper plating will be packaged with the ceramic heat dissipation base of the LED chip, which solves the problem of insufficient soldering height of the flux. , Aluminum is not easy to weld.

As a preferred technical solution, the copper layer is disposed in the notch A by electroplating.

As a preferred technical solution, one side of the composite heat dissipation substrate is provided with an LED base, and the other side is provided with a heat sink.

As a preferred technical solution, the heat sink is connected to the composite heat dissipation substrate by welding.

In the above technical solution, the heat dissipation substrate is made of copper plating on the upper and lower sides of the aluminum plate. At the same time, the packaging method between the substrate and the LED lamp beads and the connection method between the substrate and the heat sink are improved, and the thermal resistance of the high-power LED is greatly reduced.

At the same time, the copper on the lower surface of the composite board and the radiator of the LED lamp are directly welded by soldering, which not only solves the inability of aluminum to solder tin, but also improves the traditional high thermal resistance connection method using bolts, thermal conductive silicon or phase change materials. , Direct welding can greatly reduce the thermal resistance of high-power LEDs.

As a preferred technical solution, the composite copper layer is provided on the composite aluminum layer by means of electroplating.

As a preferred technical solution, the composite copper layer is provided on the composite aluminum layer in a laminated manner.

As a preferred technical solution, the LED base is an LED ceramic heat dissipation base.

Compared with the prior art, by adopting the structure of the present invention, the heat generated by the LED chip can be directly conducted to the heat-dissipating substrate, avoiding the high thermal resistance insulating layer in the traditional heat-dissipating substrate, and greatly reducing the thermal resistance of the high-power LED; At the same time, the packaging method between the substrate and the LED lamp beads and the connection method between the substrate and the heat sink are improved, which greatly reduces the thermal resistance of the high-power LED. In addition, the copper on the lower surface of the substrate and the radiator of the LED lamp are directly welded by soldering, which not only solves the problem of aluminum's resistance to soldering, but also improves the traditional high thermal resistance connection method using bolts, thermal conductive silicon or phase change materials. Direct soldering can greatly reduce the thermal resistance of high-power LEDs.

Description of drawings

Figure 1 is a schematic diagram of the structure of the copper clad laminate.

FIG. 2 is a schematic structural diagram of a heat dissipation substrate in the present invention.

FIG. 3 is a schematic view of the structure of the copper clad laminate of the present invention.

Figure 4 is a schematic diagram of milling off the copper foil and insulating layer at one time.

FIG. 5 is a schematic diagram of the structure after electroplating a layer of copper on the notch of one milling process.

FIG. 6 is a schematic diagram of the structure of the copper foil being milled off twice.

FIG. 7 is a schematic diagram after the LED and the heat sink are packaged on the thermoelectrically separated heat dissipation substrate.

Numerals in the figure: 1 is the copper foil layer, 2 is the insulating layer, 3 is the heat dissipation substrate, 31 is the composite copper layer, 32 is the composite aluminum layer, 4 is the copper layer on the gap A, 5 is the solder liquid, 601 is the electrode, 602 is the LED chip, 603 is the base, 604 is the silicon layer, 7 is the solder resist layer, 8 is the solder liquid, 9 is the heat sink, A is the primary milling notch, and B is the secondary milling notch.

The following specific embodiments will further illustrate the present invention in conjunction with the above drawings.

Detailed ways

The technical solutions provided by the present invention will be further described below with reference to the accompanying drawings.

1-7, the present invention provides a packaging method of a thermoelectric separation heat dissipation structure for a high-power LED, including the following steps:

The first step: copper-plating the upper and lower sides of the double-sided anodized aluminum plate to form a composite heat dissipation substrate. as shown in picture 2.

The second step: cover the upper surface of the composite heat dissipation substrate with an insulating layer and a copper foil layer in turn, and then press them together. As shown in Figure 3.

Step 3: Once milling, mill off the copper foil layer and insulating layer corresponding to the LED base on the upper surface of the copper clad laminate. As shown in Figure 4.

Step 4: At the position of the milled insulating layer, electroplate a copper layer with the same thickness as the insulating layer. As shown in Figure 5.

Step 5: Second milling, and then milling off a part of the copper foil gap on both sides to increase the distance between the copper foil and the copper plating in the fourth step, increase the arc voltage, and prevent breakdown. As shown in Figure 6.

Using the thermoelectric separation heat dissipation substrate produced by the above steps, the upper surface is connected to the base of the LED chip, and the lower surface is connected to the radiator through solder liquid and flux. As shown in Figure 7.

In a preferred embodiment, the thermoelectric separation heat dissipation structure realized by the above process specifically includes a heat dissipation substrate 3, an insulating layer 2 and a copper foil layer 1 sequentially arranged on the heat dissipation substrate 3, and the insulating layer 2 is successively formed on the insulating layer 2 by a milling process. A gap A is formed in the copper foil layer 1 and a gap B is formed in the copper foil layer 1; the LED package structure is arranged in the matching gap A and gap B, so that the LED base 603 is connected with the heat dissipation substrate 3, and is arranged in the The LED chip 602 of the LED base 603 is electrically connected to the copper foil layer 1 through the electrode 601 .

By adopting the above technical solution, through the structural improvement, the LED package structure can be directly fitted with the gap A and the gap B. Since the LED heat dissipation base is directly connected to the heat dissipation substrate, the heat generated by the LED chip can be directly conducted to the heat dissipation substrate. On the top, the high thermal resistance insulating layer in the traditional heat dissipation substrate is avoided, and the thermal resistance of the high-power LED is greatly reduced.

In a preferred embodiment, the heat dissipation substrate 3 is a composite substrate, comprising a composite aluminum layer 32 and a composite copper layer 31 disposed on at least one side of the composite aluminum layer 32 , the composite copper layer 31 and the LED base 603 Connect by welding.

In a preferred embodiment, the composite aluminum layer 32 is provided with a composite copper layer 31 on both sides, an LED base 603 is provided on one side, and a heat sink 9 is provided on the other side.

In a preferred embodiment, the heat sink 9 is connected to the composite copper layer 31 by welding.

In a preferred embodiment, the thermoelectric separation heat dissipation structure for high-power LEDs provided by the present invention is a composite heat dissipation substrate formed by copper plating on the upper and lower sides of double-sided anodized aluminum, and then sequentially covered with an insulating layer and copper foil, and after one milling, Copper plating, secondary milling, and then forming gaps A and B. On the gap A where the insulating layer is milled, a layer of copper with the same thickness as the insulating layer is electroplated. This copper plating will be packaged with the ceramic heat dissipation base of the LED chip. At the same time, the heat generated by the LED chip is directly conducted to the composite heat dissipation substrate, avoiding the high thermal resistance insulating layer in the traditional heat dissipation substrate, and greatly reducing the thermal resistance of high-power LEDs. In addition, the copper on the lower surface of the composite heat dissipation substrate and the heat sink of the LED lamp are directly welded by soldering, which not only solves the insufficiency of soldering of aluminum, but also improves the high thermal resistance connection of traditional bolts, thermal conductive silicon or phase change materials. method, direct welding can greatly reduce the thermal resistance of high-power LEDs.

Preferably, in one milling, the copper foil layer and the insulating layer corresponding to the ceramic heat dissipation base of the LED chip are milled off on the upper surface of the copper clad laminate to expose the copper on the upper surface of the composite board.

Preferably, in the second washing, on the basis of the first milling, a part of the copper foil is milled off from the middle to both sides, so as to increase the distance between the copper clad layer and the copper plated layer, increase the arc voltage, and prevent breakdown.

7 is a schematic diagram of the heat dissipation substrate of the present invention after the LED and the heat sink are encapsulated. The working principle is: the heat dissipation path of the LED is that the heat generated by the LED chip 602 of the LED passes through the solder layer 8, the copper layer 4, the composite copper layer 31, The composite aluminum layer 32 , the composite copper layer 31 , the solder liquid, the flux 5 , and finally the heat is dissipated to the outside through the radiator 9 . The conductive paths of the present invention are: the LED electrode 601 , the LED chip 602 of the LED, and the LED electrode 601 . The separation of heat dissipation and conduction in space is achieved.

In order to overcome the defects of the prior art, the present invention also proposes a thermoelectric separation heat dissipation packaging method for high-power LEDs,

The descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (3)

1. A packaging method of a thermoelectric separation heat dissipation structure for high-power L ED is characterized by comprising the following steps:

copper plating is carried out on the upper surface and the lower surface of the aluminum plate subjected to double-sided anodic oxidation to form a composite heat dissipation substrate; the composite heat dissipation substrate comprises a composite aluminum layer and composite copper layers arranged on two sides of the composite aluminum layer;

sequentially covering an insulating layer and a copper foil layer on the upper surface of the composite heat dissipation substrate and laminating the insulating layer and the copper foil layer together to form a copper-clad plate;

milling a copper foil and an insulating layer corresponding to the L ED base on the upper surface of the copper-clad plate to form a notch A and a notch B;

arranging a copper layer in the position of the insulation layer milled out of the notch A;

arranging L ED chips on L ED bases to form a L ED packaging structure, and arranging the bases on the copper-clad plate prepared in the above step to directly connect the bases with the composite heat dissipation substrate, so as to form a thermoelectric separation discrete thermal structure;

sequentially arranging an insulating layer and a copper foil layer on a composite radiating substrate, removing partial insulating layer materials through a milling process to expose the radiating substrate and form a gap A, and removing partial copper foil layer materials through the milling process on two sides of the gap A to expose the insulating layer and form a gap B;

l ED packaging structure is arranged in the gap A and the gap B matched with the LED packaging structure, so that the L ED base is physically connected with the composite heat dissipation substrate, and the L ED chip arranged on the L ED base is electrically connected with the copper foil layer through electrodes;

the copper layer is equal to the insulating layer in thickness and is connected with an L ED base in a welding mode;

the composite heat dissipation substrate is characterized in that an L ED base is arranged on one surface of the composite heat dissipation substrate, and a radiator is arranged on the other surface of the composite heat dissipation substrate and is connected with the composite heat dissipation substrate in a welding mode;

a composite copper layer is disposed on the composite aluminum layer in an electroplated or laminated manner.

2. The method for packaging a high power L ED with a thermoelectric separation and heat dissipation structure, as recited in claim 1, wherein the copper layer is disposed in the gap A by electroplating.

3. The method for packaging a high power L ED with a thermoelectric separation heat dissipation structure as recited in claim 1 or 2, wherein the L ED base is a L ED ceramic heat dissipation base.

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