KR101611517B1 - Led light module with improved reliability - Google Patents

Abstract

The present invention relates to an LED lighting module, and more particularly, to an LED lighting module having a structure that not only supports a substrate when using a ceramic substrate, but also has improved light uniformity, thermal conductivity, and heat radiation characteristics.

Description

[0001] LED LIGHT MODULE WITH IMPROVED RELIABILITY [0002]

The present invention relates to an LED lighting module, and more particularly, to an LED lighting module having improved reliability through a structure that not only supports a substrate when using a ceramic substrate, but also has improved light uniformity, thermal conductivity, and heat dissipation characteristics.

In general, LED (Light Emitting Diode) is a semiconductor device that emits light when current flows, and converts electrical energy into light energy with a PN junction diode made of GaAs or GaN optical semiconductor. Such an LED can irradiate light of high efficiency with low voltage and can be used in various electronic devices such as home appliances, all-optical palm, and display.

The LED lighting module generally includes a substrate or printed circuit board including a conductive layer and an insulating layer. The insulating layer may be an insulating material such as a thermosetting resin or the like and may have a certain degree of thermal conductivity. However, in the case of the LED lighting module, the thermal conductivity in the vertical direction should be excellent. However, even if the insulating layer is made of a material having thermal conductivity, since the thermal conductivity in the vertical direction is not excellent, There is a problem of increasing the defective rate of the LED lighting module due to the thermal stress.

In the case of resin used for LED lighting module, the thermal stability is lowered in a relatively high temperature environment. Therefore, there is a growing demand for the development of an LED lighting module which does not use the resin in the lighting module. The role of the resin in the LED lighting module is to maintain the insulation between the electrode and the substrate, and to strengthen the adhesion in the repeated extreme temperature change environment of light emission and extinction. Therefore, it is most important to maintain the adhesion force between the substrate and the electrode. Thus, the adhesion between the two materials is a very important property that determines the long-term reliability of the illumination. Especially, it is very important in the development of high power high power module required in high power lighting. For high power lighting modules, the heat generated by the LED light source is very high and the temperature is high. As a result, the thermal stress received by the substrate when the luminaire is turned on / off is inevitably very large. This rapid change in temperature occurs very frequently when the resin used can not withstand thermal stresses, rendering the module unable to function normally.

The manufacturing of the lighting module excluding the use of such a resin often uses metals having excellent thermal stability and oxidation stability, thereby exposing the surface of these modules to the surface of the module. In the case of white light emission, since the phosphor is used, the light reflected by the phosphor is large, and the light is reflected back to the outside of the module. Therefore, the problem of reducing the reflectance due to the use of a metal having a low reflectance should be solved.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an LED lighting module using a substrate made of a ceramic material and having improved reliability through a structure having improved light uniformity, thermal conductivity, and heat dissipation characteristics without including an insulating layer.

It is another object of the present invention to provide an illumination module having a structure capable of uniformizing thermal distribution throughout a COB (Chip On Board) to improve light uniformity.

It is another object of the present invention to provide a lighting module having a structure capable of preventing the substrate from being damaged during soldering.

Another object of the present invention is to provide a lighting module having a structure in which a substrate of a ceramic material is supported to form a thin substrate.

The object of the present invention is not limited to the above-mentioned objects, and although not explicitly mentioned, the object of the invention which can be recognized by a person skilled in the art from the description of the detailed description of the invention .

In order to accomplish the objects of the present invention described above, first, the present invention provides a ceramic substrate, A positive slug layer and a negative slug layer formed on the substrate and including at least two electrode layers formed on the substrate and a reflective layer covering the electrode layer, the spacers being spaced apart from each other by a predetermined distance; Two or more LED chips formed on the reflective layer of the (+) slug layer or the (-) slug layer with P-type and n-type electrodes; And a metal protective layer formed on the lower surface of the substrate.

In a preferred embodiment, the metal protective film has a thickness of 10 nm to 50 탆.

In a preferred embodiment, the metal protective film is made of at least one of copper (Cu) and aluminum (Al).

In a preferred embodiment, the metal protective layer is formed by any one of bonding, plating, and sputtering.

In a preferred embodiment, the thickness of the substrate and the metal protective film are inversely proportional to each other.

In a preferred embodiment, the ceramic material comprises at least one of aluminum nitride (AlN), aluminum oxide (AlOx), and silicon nitride (SiN).

In a preferred embodiment, the electrode layer is made of copper (Cu).

In a preferred embodiment, the reflective layer comprises at least one of silver (Ag), nickel (Ni), and gold (Au).

In a preferred embodiment, the reflective layer is a Ni / Ag layer or a Ni / Au / Ag layer.

In a preferred embodiment, the LED chip comprises a vertical LED chip or a horizontal LED chip.

The present invention has the following effects.

First, the LED lighting module of the present invention improves the reliability of the LED lighting module by using the substrate of the ceramic material and improving the light uniformity, thermal conductivity, and heat dissipation characteristics without including the insulation layer.

Further, the LED lighting module of the present invention has a structure capable of improving the uniformity of light by uniformizing thermal distribution in the entire COB.

Further, the LED lighting module of the present invention can prevent the substrate from being damaged during soldering.

In addition, the LED lighting module of the present invention can support a substrate of ceramic material to form a thin substrate.

These technical advantages of the present invention are not limited to the above-mentioned technical scope, and even if not explicitly mentioned, the effect of the invention which can be recognized by a person skilled in the art from the description of the concrete contents for carrying out the invention Of course.

1 is a schematic view of a lighting module using a vertical LED chip according to a first embodiment of the present invention.
2 is a detailed view of a vertical LED chip included in the LED lighting module of FIG.
3 is a schematic view of a lighting module using a horizontal LED chip according to a second embodiment of the present invention.
4 is a detailed view of a horizontal LED chip included in the LED lighting module of FIG.
5 is a schematic view of a lighting module using a horizontal LED chip according to a third embodiment of the present invention.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Also, in certain cases, there may be a term selected arbitrarily by the applicant, in which case the meaning thereof will be described in detail in the description of the corresponding invention. Accordingly, the terms used in the present invention should not be construed to be mere terms, but should be interpreted based on the ordinary meanings of the terms and contents described throughout the specification of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

1 is a schematic view of a lighting module using a vertical LED chip according to a first embodiment of the present invention, and is a detailed view of a vertical LED chip included in the LED lighting module of FIG.

1 and 2, the LED lighting module 100 according to the present invention includes a substrate 110, a positive slug layer 121, a negative slug layer 123, an LED chip 130, A wire 140 and a metal protective film 150.

First, since the LED lighting module according to the present invention does not need to include an insulating layer made of a thermosetting resin or the like by using a ceramic substrate, the manufacturing process of the LED lighting module is simplified, Can enjoy.

Accordingly, the substrate 110 is not limited as long as it is made of a ceramic material, but is preferably a ceramic material having a high thermal conductivity. That is, it is necessary to reduce the thermal resistance of the ceramic substrate in order to cope with the increase in the current density and the heat generation density due to the high output of the semiconductor device.

A substrate made of a ceramic material having such high thermal conductivity characteristics and containing at least one of aluminum nitride (AlN), aluminum oxide (AlOx) and silicon nitride (SiN) may be used. A substrate made of aluminum nitride (AlN), aluminum oxide (AlOx), or silicon nitride (SiN) can have a very high insulating property, and can have heat resistance, corrosion resistance, and high thermal conductivity.

Due to the ceramic substrate, it is possible to improve the electrical stability of the LED lighting module and to reduce the defective rate of the LED lighting module due to thermal stress due to the high heat conduction characteristic and improve the heat radiation characteristic of the LED lighting module itself.

In particular, the LED lighting module 100 according to the present invention can protect the ceramic material substrate 110 by further forming a metal protective film 150 below the ceramic material substrate 110. That is, if a metal protective film is formed on the lower part of the ceramic substrate, it is possible not only to support the substrate but also to prevent the substrate from being broken during soldering. More specifically, soldering is formed on the (+) and (-) slug layers. In this case, the high heat applied for soldering is transmitted very quickly in the slag layer, which is a metal. However, the underlying ceramic substrate, especially the aluminum oxide substrate, does not have a sufficiently high thermal conductivity to rapidly transfer such heat, so that very high thermal stress is applied between the aluminum oxide substrate and the slug layer. These transverse thermal stresses cause cracking or cracking of stressed aluminum oxide substrates rather than metals. This difficulty in the manufacturing process can be sufficiently solved by introducing the metal protective film of the present invention. In addition, the metal protective film of the present invention not only optimizes the overall heat dissipation characteristics of the module by rapidly transferring heat and thermal stress received from the aluminum oxide substrate to the outside, thereby improving the uniformity of heat distribution in the LED module, .

The metal protective film 150 is not limited as long as it is a metal having excellent heat conduction characteristics, but may be Cu, Al, or an alloy thereof. The thickness of the metal protective layer 150 may be in the range of 10 nm to 50 占 퐉. If the thickness of the ceramic substrate is thin, the thickness of the ceramic substrate is preferably thick and thin if the thickness of the ceramic substrate is sufficiently thick.

For example, when aluminum nitride (AlN) is used, it is required to have excellent heat conduction characteristics. However, when expensive materials are used, if the substrate is formed thin and the metal protective film is thickly formed, Thereby reducing the thermal stress of the substrate, thereby further improving reliability. In addition, if such a structure is provided, the manufacturing cost is remarkably reduced, and the LED lighting module can be produced at a lower cost.

On the other hand, when using aluminum oxide (AlOx) as a ceramic material in the conventional LED structure, the required characteristics such as thermal conductivity characteristics are remarkably lowered, which is almost 20 times cheaper than aluminum nitride, There was no problem. However, in the LED lighting module having the structure in which the metal protective film 150 is formed on the bottom of the ceramic substrate 110 as in the present invention, even if aluminum oxide is used as the ceramic material, There is an advantage in that reliability higher than that obtained by the configured LED lighting module can be secured.

In the present invention, the metal protective layer 150 may be formed by any known method under the substrate 110 of the ceramic material. For example, a bonding, plating or sputtering method may be used. Particularly, when metal is deposited on the ceramic material substrate 110 by the sputtering method to form the metal protective film 150, not only the substrate 110 and the metal protective film 150 have strong adhesive force but also consider heat release and thermal stress So that the thickness can be precisely controlled so as to have an optimum thickness. Therefore, it is preferable that the metal protective layer 150 is formed by a sputtering method.

As described above, according to the present invention, there is an advantage that the high thermal conductivity and the electrical insulating property that the substrate 110 should have can be adjusted as desired by the user.

The (+) slug layer 121 and the (-) slug layer 123 may be formed on the substrate 110 and spaced apart from each other and arranged alternately or adjacent to each other. (+) Slug layer 121 and a (-) slug layer 123 are formed, and each of the slug layer 121 and the slug layer 123 may be formed as a pair, and any one of them may be formed.

Each of the positive slug layer 121 and the negative slug layer 123 includes electrode layers 125a and 125b formed on the substrate 110 and reflection layers 127a and 127b covering the electrode layers 125a and 125b. .

The electrode layers 125a and 125b may be formed of a copper (Cu) layer, although not limited thereto.

The reflective layers 127a and 127b include a layer made of at least one of silver (Ag), nickel (Ni), and gold (Au). For example, the reflective layers 127a and 127b may be formed of a silver (Ag) layer. For example, the reflective layers 127a and 127b may be formed of a nickel (Ni) layer. For example, the reflective layers 127a and 127b may be formed of a gold (Au) layer.

Or the reflective layers 127a and 127b may be composed of a composite layer of at least two or more of a silver (Ag) layer, a nickel (Ni) layer, and a gold (Au) layer. For example, the reflective layers 127a and 127b may be formed of a Ni / Ag layer or a Ni / Au / Ag layer. In this case, the silver (Ag) layer is made to be the top layer of the reflective layers 127a and 127b.

The reflective layers 127a and 127b may be formed by a general plating or vapor deposition method.

The reflective layers 127a and 127b serve to protect the electrode layers 125a and 125b from corrosion and external contamination. In addition, the reflective layers 127a and 127b may reflect light emitted from the LED chip 130 to be described later, thereby contributing to an increase in the amount of light of the LED lighting module.

The LED chip 130 may include a vertical LED chip or a horizontal LED chip.

For example, when the LED chip 130 is implemented as a vertical LED chip, the LED chip 130 includes a light emitting structure as shown in FIG. 2, and a p-type electrode 131 and a p- an n-type electrode 139 is formed. The light emitting structure is also called an epi layer, and a p-type GaN-based semiconductor layer (p-GaN layer 133), an active layer 135 and an n-type GaN based semiconductor layer (n-GaN layer 137) Layered semiconductor layer. In this case, the p-GaN layer 133, the active layer 135 and the n-GaN layer 137 are formed of Al x In y Ga (1-xy) N composition formula (0? X? 1, 0? X? 1, y < = 1), and may be formed through a known nitride deposition process such as a metal organic chemical vapor deposition (MOCVD) process. And a multi quantum well layer in which an active layer quantum well layer and a barrier layer are repeatedly formed. A p-type electrode 131 is formed on the p-GaN layer 133 of the light emitting structure and an n-type electrode 139 is formed on the n-GaN layer 137. A supporting layer 132 may be formed on the p-GaN layer 133 to cover the p-type electrode 131. The support layer 132 protects the p-type electrode 131 and supports the vertical LED chip 130 when the vertical LED chip is formed on the substrate 110.

The support layer of the vertical LED chip 130 stacked on the electrode layer 125a, the reflection layer 127b and the reflection layer 127b constituting the (+) slug layer 121 are all made of a conductive material. Also, the n-type electrode is connected to the (-) slug layer 123, which is also a conductive material, by the bonding wire 140. Accordingly, when an external power source is connected to the (+) slug layer 121 and the (-) slug layer 123, current flows through the light emitting structure to emit light in the active layer.

In addition, the LED lighting module according to the first embodiment of the present invention may further include a phosphor (not shown) applied to the upper surface of the LED chip, though not shown in the figure. The phosphor may be applied only to the surface of the LED chip where all of the LED chip is coated or the light is emitted from the LED chip. The color of the light emitted by applying the phosphor can be adjusted. For example, when a yellow phosphor is coated on a blue LED chip, an LED lighting module in which white light is emitted can be obtained.

Accordingly, the LED lighting module according to the first embodiment of the present invention includes a substrate 110 that does not include a general insulating layer, and the substrate 110 itself has a high thermal conductivity made of a ceramic material, The metal protective layer 150 is further formed on the lower portion of the LED lighting module 110, thereby improving the thermal conductivity and heat dissipation characteristics of the LED lighting module, thereby remarkably reducing the defective rate of manufacturing the LED lighting module due to thermal stress.

In addition, since the slug layers 121 and 123 include the reflection layer 127, light reflected from the phosphors coated on the LED chip 130 during white light emission can be reflected to the outside of the module, The light quantity of the lighting module 100 itself is increased, and the efficiency of the LED lighting module can be improved.

FIG. 3 is a schematic view of a lighting module using a horizontal LED chip according to a second embodiment of the present invention, and FIG. 4 is a detailed view of a horizontal LED chip included in the LED lighting module of FIG.

FIG. 3 shows a case where the LED chip includes the horizontal LED chip, not the vertical LED chip, in the embodiment of FIG. 1, and FIG. 4 is a detailed view of the horizontal LED chip used in FIG.

3 and 4, the LED lighting module 100 according to the second embodiment of the present invention includes a substrate 110, (+) slug layers 121a and 121b, (-) slug layers 123a and 123b , Horizontal LED chips 130a and 130b, a bonding wire 140, and a metal protective film 150. [

The detailed description of each component is the same as or similar to that shown in FIG. 1, and therefore, detailed description thereof will be omitted. However, in this embodiment, the connection of the bonding wires 140 due to the use of the horizontal type LED chips and the horizontal type LED chips is different from that of FIG.

The structure of the horizontal flat LED chip 130 shown in FIG. 4 is also the same as that of a known horizontal flat type LED chip, but will be briefly described below.

A first horizontal LED chip 130a is formed on the first (+) slug layer 121a. First, a substrate 132 of the first horizontal LED chip 130a is formed. An n-type gallium nitride Type semiconductor layer (n-GaN layer) 137 is formed on part of the n-type GaN layer, an active layer 335 on the other part of the n-type electrode 139 and the active layer 335, a p-GaN layer 133, and a p-type electrode 131 are sequentially stacked.

And the second horizontal LED chip 130b having the same configuration is formed in the second (-) slug layer 123b.

Therefore, the p-type electrode 131 of the first horizontal LED chip 130a is connected to the first (-) slug layer 123a by the bonding wire 141, and the n-type electrode 131 of the first horizontal LED chip 130a is connected to the n- Type electrode 139 is connected to the p-type electrode of the second horizontal LED chip 130b by the bonding wire 142 and the n-type electrode of the second horizontal LED chip 130b is connected to the second (- (123b) and the bonding wire (143).

5 is a schematic view of a lighting module using a horizontal LED chip according to a third embodiment of the present invention. The LED lighting module 100 of FIG. 5 is the same as the corresponding component of FIG. 3 except that a plurality of horizontal LED chips 130a to 130e are formed after a single slag layer 121a is formed long. Therefore, the same description will be omitted here.

Accordingly, when the first through fifth horizontal LED chips 130a through 130e are formed on the (+) slug layer 121a, the first horizontal LED chip 130a is connected to the bonding wire 140, The p-type electrode of the second horizontal LED chip 130b is connected to the first slug layer 123a by the bonding wire 141 and the n-type electrode of the first horizontal LED chip 130a is connected to the p- And the bonding wire 142 is connected to the electrode.

The n-type electrode of the second horizontal type LED chip 130b is connected to the p-type electrode of the third horizontal type LED chip 130c by the bonding wire 143. The n-type electrode of the third horizontal type LED chip 130c is connected to the n- Is connected to the p-type electrode of the fourth horizontal LED chip 130d by the bonding wire 144.

The n-type electrode of the fourth horizontal type LED chip 130d is connected to the p-type electrode of the fifth horizontal type LED chip 130e by the bonding wire 145, and the n-type electrode of the fifth horizontal type LED chip 130d Is connected to the second (-) slug layer 123b by a bonding wire 146.

Although several embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various modifications may be made without departing from the spirit or scope of the present invention . The scope of the invention will be determined by the appended claims and their equivalents.

100: LED lighting module 110: substrate
(+) Slug layer 123, 123a, 123b: (-) slug layer
130, 130a, 130b, 130c, 130d, 130e: LED chip
140: bonding wire 150: metal shield

Claims (10)

A ceramic substrate;
A (+) slug layer and a (-) slug layer which are formed on the substrate and include at least two electrode layers formed on the substrate and a reflective layer covering the electrode layer, the spacers being spaced apart from each other by a predetermined distance;
Two or more LED chips formed on the reflective layer of the (+) slug layer or the (-) slug layer with P-type and n-type electrodes; And
And a metal protective layer formed under the substrate,
Wherein the reflective layer is a nickel (Ni) / silver (Ag) layer or a nickel (Ni) / gold (Au) / silver (Ag) layer.
The method according to claim 1,
Wherein the metal protective film has a thickness of 10 nm to 50 占 퐉.
The method according to claim 1,
Wherein the metal protective film is made of at least one of copper (Cu) and aluminum (Al).
The method according to claim 1,
Wherein the metal protective layer is formed by any one of bonding, plating, and sputtering.
The method according to claim 1,
Wherein the thickness of the substrate and the metal protective film are inversely proportional to each other.
The method according to claim 1,
Wherein the ceramic material is at least one of aluminum nitride (AlN), aluminum oxide (AlOx), and silicon nitride (SiN).
The method according to claim 1,
Wherein the electrode layer is made of copper (Cu).
delete delete The method according to claim 1,
Wherein the LED chip comprises a vertical LED chip or a horizontal LED chip.

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