KR101163645B1 - High power led module and method for manufacturing the same - Google Patents

Abstract

By directly attaching the LED element and the heat sink using a thermally conductive material (TIM), it is possible to provide a high brightness or high power LED module with a minimum heat conduction path. The heat sink is formed to have a cup-shaped reflecting portion and a concave portion on a surface thereof, an insulating layer and a metal layer are formed on the concave portion of the formed heat sink, and the LED element is formed on the reflecting portion of the formed heat sink by using a TIM. Attach, and connect the LED element and the metal layer through a conductive wire. Therefore, the heat dissipation efficiency of the LED module is improved and the reliability of the LED product is achieved.

LED, high power, heat sink, heat dissipation

Description

High power light emitting diode module and its manufacturing method {HIGH POWER LED MODULE AND METHOD FOR MANUFACTURING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode (LED) module, and more particularly, to a high output or high brightness LED module for improving heat dissipation efficiency of an LED and a method of manufacturing the same.

LED is a semiconductor device that emits light when a voltage is applied in the forward direction, and is widely used in display devices such as electronic displays. Recently, many researches have been conducted on high brightness (HB) LEDs for lighting that can replace lighting devices such as incandescent and fluorescent lamps.

Generally, high brightness LEDs mean LEDs of 1W or more per unit and narrowly mean LEDs for general lighting. The light efficiency (lm / W) of LEDs was already available at the level of incandescent lamps in the early 1990s, and has been steadily increasing so far.

Currently, high brightness LEDs have a problem of increasing the efficiency of heat dissipation as input power increases, which is closely related to the heat dissipation problem. In other words, high-brightness LEDs cause significant temperature rises during operation, which increase the LED light efficiency and lifespan, thereby reducing the reliability of the LEDs. This heat dissipation problem is not only an LED chip (chip), but also an important problem in the module, package (package) and the final product including the same, and various researches for solving this problem are being actively conducted.

1 shows a structure of a conventional general high brightness LED module.

As shown in FIG. 1, the conventional LED module includes an LED device 10, a transparent lens 20 for molding the LED device 10, a wire 30 and a lead frame 40 for electrical connection, and an LED device ( A die bonding layer 50 for mounting 10), a heat slug 60 for heat dissipation, a solder pad 70, and the like are formed on the substrate.

As a substrate, a metal core printed circuit board (MC-PCB) composed of a dielectric layer 80 and a metal layer 90 is widely used. Eutectic solder (Au-Sn) or silver epoxy (silver epoxy) are widely used.

A heat sink 110 is bonded to the bottom of the substrate for heat dissipation, and a thermal interface material (TIM) 100 for bonding the heat sink 110 to the metal layer 90 of the substrate. ) Is used.

Aluminum is mainly used as a material of the heat sink 110, and a phase change material (PCM) or silver paste may be used as the material of the TIM 100.

One of the heat dissipation features of the LED module is that most of the heat is transferred to the bottom of the LED element and released because the heat emission is limited by the phosphor or transparent lens above the LED element. That is, the heat dissipation of the LED module depends on the phenomenon that heat is conducted downward of the LED element.

In the case of the conventional LED module described above, the LED element 10-die bonding layer 50-heat slug 60-solder pad 70-substrate 80, 90-TIM 100-heat sink 110 In order of), a thermal path is formed.

As such, the various layers formed between the LED element 10 and the heat sink 110 all act as resistors for heat dissipation of the LED element, thereby reducing heat dissipation efficiency. In other words, the conventional LED module has a structure in which heat is transferred through a very complicated layer, and the materials constituting each layer act as heat radiating resistors connected in series. have.

In order to solve such problems of the conventional heat transfer structure, a technique for reducing thermal resistance by applying a technology such as a multichip on aluminum metal plate (MOAMP) or a chip on board (COB) has been developed. Since materials of various materials such as an insulating layer and a metal layer still exist in the heat dissipation path of the LED, there is a limit in increasing the efficiency of heat dissipation.

The present invention is to solve the heat dissipation problem of the conventional LED module, by providing a high brightness or high power LED module having a minimum heat conduction path, thereby improving the heat dissipation efficiency of the LED module, stabilizing and manufacturing the life of the LED product To achieve a reduction in costs.

In order to achieve the above object, the manufacturing method of the LED module including the LED element according to the present invention, using a metal, the upper surface has a cup-shaped reflecting portion, and the heat between the recessed portion located between the reflecting portion Forming a sink, forming an insulating layer in a recess of the formed heat sink, forming a metal layer on the insulating layer, and a heat conductive material (TIM) on the reflecting portion of the formed heat sink. Attaching the LED device by using the method, and connecting the LED device and the metal layer through a conductive wire.

In addition, the manufacturing method of the LED module according to the present invention, may further comprise the step of forming a phosphor layer on the reflective portion of the molded heat sink.

On the other hand, to achieve the above object, the LED module according to the present invention is formed of a metal material, the heat sink having a cup-shaped reflection portion on the upper surface, and a recess formed between the reflection portion, and a thermally conductive material ( TIM), an LED element directly adhered onto the reflecting portion of the heat sink, an insulating layer formed on the recess of the heat sink, and formed on the insulating layer, and connected to the LED element through a conductive wire. It includes a metal layer.

In addition, the LED module according to the present invention may further include a phosphor layer formed on the reflecting portion of the heat sink.

In addition, the heat sink is preferably made of aluminum or copper.

The LED module according to the present invention can minimize the thermal resistance in the LED module by mounting the LED element directly to the heat sink. That is, by minimizing the heat conduction path from the LED element to the heat sink, it is possible to maximize the heat dissipation efficiency of the LED module.

In addition, since the insulating layer, the substrate, and the like are not required, the manufacturing cost of the LED module can also be reduced.

Therefore, high output and high brightness of the LED module for lighting can be achieved, and the reliability and product life of the LED product can be improved.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the present invention will be described.

(First Example )

2 schematically shows an LED module having a heat dissipation structure according to a first embodiment of the present invention.

As shown in FIG. 2, the LED module according to the present invention has a structure in which the LED device 200 is directly mounted on the metal heat sink 250. Between the LED element 200 and the heat sink 250, a TIM 240 for joining them is formed.

TIM 240 is also electrically insulating as a thermally conductive material. The TIM 240 is a thermal grease, a thermal epoxy adhesive, a thermally conductive silicone pad, a thermally conductive adhesive tape, a graphite sheet, a thermally conductive phase, and a PCM. Change Material).

The heat sink 250 is formed with a cup-shaped reflector 251 for adjusting the directivity angle of the light emitted from the LED element 200, and a recess 252 in which the insulating layer 230, which will be described later, is formed. . The LED device 200 is bonded to the center of the reflector 251.

In order to further improve reflection performance, a phosphor layer (not shown) may be further formed on the cup-shaped reflection part 251. In addition, an epoxy dome (not shown) may be formed on the reflector 251 to further improve directivity. The heat sink 250 is preferably made of copper or aluminum having high thermal conductivity.

In addition, a conductive wire 210 is connected to the metal layer 220 on the heat sink 250 so as to connect an electrical power source to the LED device 200. The metal layer 220 to which the conductive wire 210 is connected is insulated from the heat sink 250 by the insulating layer 230. The insulating layer 230 may use an oxide-based dielectric material.

The LED module according to the present invention is a chip on heat-sink (COH) structure in which the LED device 200 is directly attached to the heat sink 250 as described above, thereby minimizing thermal resistance in the LED module. As indicated by arrows in FIG. 2, heat dissipation efficiency can be significantly increased by achieving a heat conduction path in which the number of thermal resistors from the LED element 200 to the heat sink 250 is reduced to one.

Next, a manufacturing method of the LED module according to the first embodiment of the present invention will be described with reference to FIG. 3.

First, a heat sink 250 having a cup-shaped reflector 251 capable of freely adjusting the directivity angle of the light emitted from the LED element 200 and a recess 252 on which the insulating layer 230 is to be formed is formed. (Step 1). The recess 252 of the heat sink may be formed using a dry etching method or a wet etching method, or may be formed using a mechanical cutting method. In addition, if necessary, phosphors may be adhered to the cup-shaped reflector 251 of the heat sink 250, or an epoxy dome may be bonded to improve directivity.

Next, an insulating layer 230 is formed in the recess 252 on the surface of the molded heat sink 250 (step 2). The insulating layer 230 may be formed by anodizing using an oxide-based material, or by a deposition method such as chemical vapor deposition or sputtering.

Next, the metal layer 220 is formed on the insulating layer 230 (step 3).

The metal layer 220 may be formed using an electron beam deposition method or a sputtering method.

Next, the LED device 200 is attached onto the molded heat sink 250 using the appropriate TIM 240 material (step 4).

Next, the LED device 200 and the metal layer 220 are connected through the conductive wire 210, so that electric power can be applied to the LED device 200 (step 5).

By using the same method as described above, an LED module having a chip on heat-sink (COH) structure with a minimum heat conduction path between the LED element 200 and the heat sink 250 can be manufactured.

(Second Example )

4 schematically shows an LED module having a heat dissipation structure according to a second embodiment of the present invention.

The LED module according to the second embodiment of the present invention differs from the first embodiment only in that a recess is not formed on the surface of the heat sink 250, and the others are the same as the first embodiment. That is, as shown in FIG. 4, the insulating layer 230 is formed on the surface of the heat sink 250, and the metal layer 220 is formed thereon.

5 shows a method of manufacturing the LED module according to the second embodiment.

As shown in FIG. 5, the method of manufacturing the LED module according to the second embodiment includes only the first step of forming the heat sink 250 and the second step of forming the insulating layer 230. Other manufacturing methods (steps 3 to 5) are the same as in the first embodiment. That is, in the first step, the heat sink 250 is formed to have only the reflector 251, and in the second step, the insulating layer 230 is formed on the surface of the heat sink 250. To form the insulating layer 230, a chemical vapor deposition or sputtering method may be used.

In the manufacturing method of the LED module according to the second embodiment of the present invention, like the first embodiment, a LED module having a COH structure with a minimum heat conduction path between the LED element 200 and the heat sink 250 can be manufactured. .

Although the present invention has been described with reference to the above-described preferred embodiments and the accompanying drawings, different embodiments may be constructed within the spirit and scope of the invention. Therefore, the scope of the present invention is defined by the appended claims, and should be construed as not limited to the specific embodiments described herein.

1 is a schematic view showing the structure of a conventional LED module.

2 is a schematic view showing the structure of an LED module according to a first embodiment of the present invention.

3 is a flowchart illustrating a method of manufacturing the LED module according to the first embodiment of the present invention.

4 is a schematic diagram showing the structure of an LED module according to a second embodiment of the present invention.

5 is a flowchart illustrating a method of manufacturing an LED module according to a second embodiment of the present invention.

Claims (8)

In the manufacturing method of the LED module including the LED (Light Emitting Diode) device, Forming a heat sink using a metal, the heat sink having a cup-shaped reflection portion and a recess spaced from the reflection portion on an upper surface thereof; Forming an insulating layer on a recess of the molded heat sink; Forming a metal layer on the insulating layer; Attaching the LED element on the reflective portion of the formed heat sink using a thermal conductive material (TIM); And connecting the LED element and the metal layer through a conductive wire. delete The method of claim 1, And forming a phosphor layer on the reflecting portion of the molded heat sink. The method of claim 1, The recess of the heat sink is formed using a dry etching method or a wet etching method. A heat sink formed of a metal material and having a cup-shaped reflecting portion and a recess spaced from the reflecting portion on an upper surface thereof; An LED element directly bonded onto the reflecting portion of the heat sink by using a thermal conductive material (TIM), An insulating layer formed in a recess of the heat sink; And a metal layer formed on the insulating layer and connected to the LED element through a conductive wire. delete The method of claim 5, And a phosphor layer formed on the reflecting portion of the heat sink. The method of claim 5, The heat sink is an LED module, characterized in that the aluminum or copper material.

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