KR101418008B1 - Substrate for LED and LED heat-sink structure - Google Patents

Abstract

The present invention provides a substrate for an LED comprising a ceramic substrate, and a copper plate bonded to one or both surfaces of the ceramic substrate using a DCB (Direct Copper Bonding) method. , The LED substrate and the heat dissipation structure manufactured according to the present invention can increase the copper thickness compared with the conventional products and reduce the heat amount generated on the copper surface by raising the heat dissipating cross- Can be effectively controlled.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate,

The present invention relates to a substrate for an LED, an LED heat dissipation structure, and the like.

LEDs (light emitting diodes), a type of diode that emits light when the electric current is flowing, is very important to control the heat dissipated from the LED in watt-class LEDs and products with Φ8mm 50mA and above. Driving the LEDs requires 20% of the light and 80% of the heat, so it is necessary to control the heat so that the LEDs can not be used unless the heat is controlled. LEDs are semiconductor chips, which are very small in size, and the heat generated by the LEDs can take a long life.

LEDs are low power consumption devices with high power efficiency and can last for over 250,000 hours longer than known. However, since it is only possible to catch heat, it is preferable to use 50,000 hours as the actual heat dissipation technology.

If the temperature of the LED can be managed only 20 degrees or less, the lifetime of the LED may exceed 250,000 hours. However, how fast it dissipates its own heat is the key, and it is necessary to have a technology that can effectively control the heat dissipation at a reasonable cost. Especially, the heat dissipation characteristics of the LED at a high temperature of about 60 degrees is a factor directly related to the lifetime of the LED.

In addition, if the generated heat is not rapidly processed, the LED chip affects the peripheral circuits as well as the reliability of the product. Thermal shocks accumulated over a long period of time cause product problems. According to the related industry, more than 50% of LED failures are caused by heat generation, and the rest are caused by humidity, vibration, shock, dust, and the like.

Currently, trends in LED lighting products can be defined as four characteristics: high output, small size, light weight, and low cost. In other words, the output is stronger, the size is smaller and lighter, and the price is getting lower. This can be seen as a characteristic of LED lighting as it enters the commercialization stage from the research product stage.

With such trends, the density of heat generated by LEDs can not but increase. As the output of the LED increases, the heat is increasing more and more, but the heat transfer and emission space is getting smaller. Therefore, heat dissipation is a top priority in LED usage.

On the other hand, recently, increasing commercial value through cost reduction and design improvement has also become an important factor. Therefore, a different type of heat radiation function is required.

[Prior Art Document]
Japanese Unexamined Patent Application Publication No. 2011-119343 (published on June 16, 2011)

As a heat dissipation method that can be considered in the first place, a method of forming a heat dissipation structure by processing laser via holes in ceramics and forming copper through Ti-Cu sputtering, chemical Cu plating, and Cu-plating is considered. However, in this case, the thickness of copper is as thin as about 50 占 퐉, which causes a problem of poor heat dissipation characteristics.

The various embodiments of the present invention are intended to solve the above-mentioned problems, and one or more of the following problems are solved.

That is, the present invention provides an LED substrate and a heat dissipation substrate which can improve the thermal property by reducing the amount of heat generated on the copper surface by increasing the cross-sectional area of electrical conduction by increasing the thickness from 50 탆 to 500 탆, Structure. ≪ / RTI >

Another object of the present invention is to provide a substrate for an LED and a heat dissipation structure that can realize a low cost through a simplified process.

As means for solving the above problem,

The present invention relates to a ceramic substrate; And a copper plate bonded to one side or both sides of the ceramic substrate using DCB (Direct Copper Bonding) method.

Also, the thickness of the copper plate is in the range of 50 to 500 mu m.

Also, the ceramic substrate has a via hole filled with a conductive material.

Also, the diameter of the via hole is in the range of 0.01 to 1.0 mm.

Also, a copper plate formed on one or both surfaces of the ceramic substrate is etched to form a circuit pattern.

The circuit board is divided into an electrical connection portion for driving the LED and a heat dissipation portion for dissipating heat of the LED. The circuit board according to any one of Claims 1 to 3, .

Also, an LED is mounted on the heat dissipation part, and the electrical connection part and the LED are electrically connected by a wire.

In addition, the electrical connection part and the heat dissipation part all include an upper copper plate, a via hole filled with a conductive material, and a lower copper plate.

Also, the electrical connection portion and the heat dissipation portion are fabricated together in the same process.

The present invention also relates to a substrate for LED of the above-mentioned one; And an LED mounted on one surface of the LED mounting board.

The circuit board according to the present invention provides at least one or more of the following effects.

That is, the LED substrate and the heat dissipation structure manufactured according to the present invention can increase the copper thickness as compared with the conventional product, and the heat dissipation structure increases the heat dissipation cross- The heat can be effectively controlled.

1 is a schematic cross-sectional view illustrating an LED substrate and an LED heat dissipation structure according to an embodiment of the present invention.

Hereinafter, the LED substrate and the LED heat dissipation structure according to the present invention will be described in detail. Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be understood that the invention is not limited to the disclosed embodiments.

The present invention provides a substrate for an LED comprising a ceramic substrate, and a copper plate bonded to one or both surfaces of the ceramic substrate using a DCB (Direct Copper Bonding) method. The at least one copper plate serves as a heat sink. The DCB method can increase the thickness of the copper plate to about 300 to 500 mu m, which is structurally simpler than the conventional LED heat dissipation method, and can significantly improve the heat dissipation characteristic.

The ceramic substrate can be made of various materials and is not limited. For example, the ceramic substrate 10 may be made of a ceramic material such as alumina (Al2O3), aluminum nitride (AlN), silicon carbide (SiC), and silicon nitride (Si3N4). Further improvements in high reliability and thermal properties may be possible due to the wide variety of applicability of ceramic materials.

The copper plate is not limited, and a copper plate that can be used for DCB is used. The copper plate may be bonded to one or both surfaces of the ceramic substrate by the DCB method. The DCB junction method itself is well known, and is well known, thereby resulting. Exemplary DCB bonding schemes are performed at temperatures above the eutectic point of copper and oxygen. The initial Copper Sheet forms a thin oxide film and is heated to a temperature between 1065 ° C above the eutectic point and 1085 ° C, the melting point of the copper, in contact with the ceramic substrate during the process. Then, the pure copper remains in a solid state, and the eutectic mixture of copper and oxygen is formed into a liquid phase to have intimate properties with the ceramic, and the copper plate and the ceramic substrate are bonded to each other by wetting the surface of the ceramic substrate.

The thickness of the copper plate is not limited, but is preferably in the range of 50 to 500 mu m. When the thickness is less than 50 탆, the heat dissipation characteristics are poor. When the thickness exceeds 500 탆, a ceramic crack due to a difference in thermal expansion coefficient at the bonding interface between ceramic and copper may be caused.

The ceramic substrate may be formed with a via hole filled with a conductive material. By constructing the conductive via hole, both sides of the ceramic substrate can be energized through the via hole. The filling material of the via hole is not limited, but conductive paste, conductive powder and the like can be used. Meanwhile, the via hole can function to dissipate the heat generated from the LED to the opposite side of the ceramic substrate. For this purpose, the via hole can be filled with a material having better heat transfer characteristics than the ceramic substrate. In particular, a via hole of a heat dissipating portion described later can be filled with a material having a good heat dissipation property. The diameter of the via hole is not limited, but is preferably in the range of 0.01 to 1.0 mm. If the thickness is less than 0.01 mm, the resistance may be increased and the heat radiation characteristic may be deteriorated. If the thickness is more than 1.0 mm, the cost may increase due to the use of the filling material, and the degree of integration and substrate durability may be a problem.

1 is a schematic cross-sectional view illustrating an LED substrate and an LED heat dissipation structure according to an embodiment of the present invention. 1, copper patterns formed on one or both surfaces of the ceramic substrate 10 may be etched to form copper patterns 20, 30, 50, and 60. The etching method may use conventional photolithography methods and is not limited. The LED 70 may be mounted on the ceramic substrate 10 and the LED may be electrically connected to the copper pattern by wire or the like.

Meanwhile, the copper pattern may be divided into an electrical connection part A for driving the LED, and a heat dissipation part B for dissipating the heat of the LED. That is, the copper pattern 50 may be formed on the heat dissipation part B at the position where the LED 70 is mounted. The copper pattern 50 is bonded to the LED 70 to emit heat generated from the LED 70. For more effective heat dissipation, a via hole 40 and a copper plate (or copper pattern 60) on the other side may be formed. The heat generated by the LED 70 can be quickly dissipated by transferring the heat through the via hole 40 to the copper plate (or copper pattern) 60 formed on the other surface. In this case, the diameter of the via hole can be made larger than that of the via hole for energizing the via hole to perform the heat transfer function effectively. Preferably, the diameter of the heat-dissipating via-hole may be 1 to 10 times the diameter of the via hole for conducting electricity.

The copper pattern 20 of the electrical connection portion A for LED driving is formed adjacent to the position of the LED 70 and is energized by way of the LED 70 and the wire 80 or the like.

The electrical connection portion A and the heat dissipation portion B may include an upper copper plate, a via hole filled with a conductive material, and a lower copper plate. The term " copper plate " The electrical connection portion and the heat dissipation portion can be manufactured together in the same process. That is, the copper plate can be manufactured at the same time by joining by DCB, and can be produced together by etching at the same time even when forming a copper pattern. Also, via hole formation and conductive material filling can be performed together. Therefore, the heat radiating portion forming process can be simplified.

The LED heat dissipation structure according to another embodiment of the present invention provides an LED heat dissipation structure including an LED mounted on one side of the LED substrate (see FIG. 1). By mounting the LED on the heat dissipation unit, the heat dissipation can be more effectively performed, and a copper plate of sufficient thickness for heat dissipation can be formed, so that the heat dissipation cross-sectional area can be increased.

10: Ceramic substrate
20, 30, 50, 60: copper plate (copper pattern)
40:
70: LED
80: wire

Claims (10)

A ceramic substrate;
And a copper plate bonded to both surfaces of the ceramic substrate using DCB (Direct Copper Bonding) method,
The thickness of the copper plate is in the range of 300 to 500 mu m,
The copper plates on both sides are etched to form a circuit pattern,
The circuit pattern is divided into an electrical connection part for driving the LED and a heat dissipation part for dissipating heat of the LED which is not electrically connected to the external terminal,
Wherein the electrical connection portion and the heat dissipation portion include a patterned upper copper plate, a via hole filled with a conductive material, and a patterned lower copper plate.
delete The method according to claim 1,
Wherein the ceramic substrate has a via hole filled with a conductive material.
The method of claim 3,
And the diameter of the via hole is within a range of 0.01 to 1.0 mm.
delete delete The method according to claim 1,
Wherein an LED is mounted on the heat dissipation unit, and the LED and the electrical connection unit are energized with a wire.
delete The method according to claim 1,
Wherein the electrical connection portion and the heat dissipation portion are fabricated together in the same process.
A substrate for an LED as set forth in any one of claims 1, 3, 4, 7, and 9;
And an LED mounted on one surface of the LED mounting board.

Images