KR20110119916A - Led bare chip - Google Patents

Abstract

PURPOSE: An LED bare chip is provided to integrate a light emitting device and thermoelectric device by welding, thereby effectively emitting heat generated from the light emitting device. CONSTITUTION: A thermoelectric device layer(12) is placed on a substrate(11). A first semiconductor layer(13) is placed on the thermoelectric device layer. A light emitting layer(15) is placed on the first semiconductor layer. A second semiconductor layer(17) is placed on the light emitting layer. A second electrode(23) is placed on the second semiconductor layer.

Description

LED Bare Chip {LED BARE CHIP}

The present invention relates to a semiconductor light emitting device, and more particularly, to a technology for efficiently dissipating heat generated in a semiconductor light emitting device using the Peltier effect.

Light emitting diodes (hereinafter referred to as LEDs) are devices that realize light emission by electric field effect by depositing a compound semiconductor thin film on a substrate, and have recently been actively used as displays for lighting, communication, and various electronic devices.

Among various applications of LED, each researcher's efforts are very active in the field of back light unit (BLU) used in thin-film TV such as LCD and lighting field that can replace fluorescent lamp. In order to apply LEDs to these applications, studies on LED structures, materials, and packages are being actively conducted. The function expression of LED is the process of injecting electrons and holes and dissipating energy in the form of light when they are combined and dissociated. Multiple energy is then released as heat and the heat generated can be alleviated by a suitable heat sink in the manufacture of the package. However, there is currently no device that suppresses heat generation inside the LED chip, but for this purpose, an attempt is made to obtain high power while solving this through a change in arrangement and structure. If the heat reduction device is not perfect, the LED output is limited, the freedom of package design is reduced, and the light emission and extraction efficiency may be reduced by various structures.

In the manufacturing process of the light emitting device, an LED bare chip is proposed, in which a thermoelectric device and a light emitting device are joined to each other to integrate and emit heat generated from the light emitting device through the light emitting device.

In accordance with an aspect of the present invention, an LED bare chip includes: a substrate; A thermoelectric element layer formed on the substrate; And a light emitting part formed on the thermoelectric element layer to emit light; The thermoelectric element layer absorbs and emits heat generated from the light emitting part.

The thermoelectric element layer may include a heat dissipation unit bonded to the substrate; A plurality of P-type semiconductors and N-type semiconductors spaced apart from each other on the heat dissipation unit; And a cooling unit having the same material as that of the heat dissipating unit and formed on an upper surface of the P-type semiconductor and the N-type semiconductor and bonded to the lower surface of the light emitting unit, wherein the cooling unit absorbs heat generated from the light emitting unit to release the heat. Can be passed to wealth.

According to another aspect of the present invention, an LED bare chip includes a thermoelectric element layer disposed on a substrate; A first semiconductor layer positioned on the thermoelectric element layer and having an opening surface; An emission layer on the first semiconductor layer; A second semiconductor layer on the light emitting layer; A first electrode on the opening surface of the first semiconductor layer; And a second electrode on the second semiconductor layer.

The thermoelectric element layer may include a heat dissipation unit bonded on the substrate; A plurality of P-type semiconductors and N-type semiconductors spaced apart from each other on the heat dissipation unit; And a cooling unit having the same material as that of the heat dissipating unit and formed on top of the P-type semiconductor and the N-type semiconductor and bonded to the lower surface of the first semiconductor layer, wherein the cooling unit absorbs heat generated from the light emitting unit. It can be delivered to the heat dissipation unit.

The first semiconductor layer may be an n-type nitride semiconductor layer.

The light emitting layer may have a quantum well structure or a multi quantum well structure.

The light emitting layer may be made of one of InGaN / GaN, AlGaN, and AlInGaN.

The second semiconductor layer may be a p-type nitride semiconductor layer.

The first electrode may be an n-type electrode, and the second electrode may be a p-type electrode.

According to another aspect of the present invention, an LED bare chip includes a thermoelectric element layer disposed on a substrate; An adhesive layer on the thermoelectric element layer; A metal reflective layer on the adhesive layer; A first semiconductor layer on the metal reflective layer; An active layer positioned on the first semiconductor layer; A second semiconductor layer on the active layer; And an electrode pad formed on the second semiconductor layer.

The first semiconductor layer may be a P-type semiconductor layer, and the second semiconductor layer may be an N-type semiconductor layer.

According to the LED bare chip according to the embodiment of the present invention, the heat generated from the light emitting device can be released by bonding and integrating the light emitting device and the thermoelectric device in the manufacturing process of the LED bare chip.

1 is a cross-sectional view of an LED bare chip according to an embodiment of the present invention.
2 is a cross-sectional view of a thermoelectric element layer according to an exemplary embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to intention or custom of a user or an operator. Therefore, the definition should be made based on the contents throughout the specification.

1 is a cross-sectional view of an LED bare chip according to an embodiment of the present invention.

1 is a cross-sectional view of a horizontal LED bare chip according to an embodiment of the present invention.

The horizontal LED bare chip according to the exemplary embodiment of the present invention includes a substrate 11, a thermoelectric element layer 12 disposed on the substrate 11, and a light emitting part formed on the thermoelectric element layer 12. At this time, the thermoelectric element layer 12 is a plurality of P is spaced apart from each other on the top of the heat dissipation unit 110, the heat dissipation unit 110 formed on the substrate 11, as shown in Figure 2 coupled to the π type It is composed of the cooling material 120 formed on top of the P-type semiconductor and the N-type semiconductor (111, 1120) having the same material as the semiconductor, the N-type semiconductor (111, 112), the heat dissipation unit (110).

At this time, by forming the thermoelectric element layer 12 on the substrate 11 it is possible to reduce the number of masks and to reduce the manufacturing process of the LED bare chip. That is, in the case of configuring the LED bare chip and the thermoelectric element, the silicon on insulator (SOI) should be performed on the LED wafer and the thermoelectric element wafer. In the manufacturing process of the LED bare chip, the thermoelectric element layer 12 is placed on the substrate 11. ), The SOI process can be omitted.

When a current supplied from the outside flows in the heat dissipating part 110 of the thermoelectric element layer 12, radiation and absorption of heat occurs in the bonded region. In other words, electrons in heterogeneous semiconductors in the junction region have a difference in potential energy, electrons increase kinetic energy to change energy levels, and absorb ambient heat, resulting in a cooling effect.

A light emitting part is formed on the thermoelectric element layer 12, and the light emitting part has a structure as follows. That is, the first semiconductor layer 13 having an opening surface is located. Here, the first semiconductor layer 13 may be an n-type nitride semiconductor layer. The first semiconductor layer 13 may be positioned on a homogeneous substrate such as GaN, or may be disposed on a heterogeneous substrate 10 such as sapphire (Al 2 O 3), silicon (Si), silicon carbide (SiC), or the like.

Next, the light emitting layer 15 is positioned on the first semiconductor layer 13. In this case, the emission layer 15 may have an InGaN / GaN quantum well (QW) structure. In addition, materials such as AlGaN and AlInGaN may also be used as the light emitting layer 15.

In the light emitting layer 15, when an electric field is applied through an electrode, light is generated by the combination of an electron-hole pair. In addition, the light emitting layer 15 may have a plurality of quantum well structures (QW) as described above in order to improve luminance, thereby forming a multi quantum well (MQW) structure.

The second semiconductor layer 17 is positioned on the light emitting layer 15. The second semiconductor layer 17 may be a p-type nitride semiconductor layer.

In addition, the first electrode 21 is positioned on the opening surface of the first semiconductor layer 13, and the second electrode 23 is positioned on the second semiconductor layer 17. In this case, the first electrode 21 may be an n-type electrode, and the second electrode 23 may be a p-type electrode 62 to have a structure of a horizontal LED bare chip. .

As shown in FIG. 1, in a horizontal type LED bare chip, heat is generated more strongly than other parts in a portion 41 in which current is locally concentrated instead of being distributed throughout the LED bare chip. As such, the generated heat is released by the thermoelectric element layer 12. That is, heat generated in the first semiconductor layer 13 is absorbed by the cooling unit 120 of the thermoelectric element layer 12 and is released through the heat dissipation unit 110.

3 is a cross-sectional view of the LED bare chip according to another embodiment of the present invention.

3 is a cross-sectional view of a horizontal LED bare chip according to an embodiment of the present invention.

The horizontal LED bare chip according to the exemplary embodiment of the present invention includes a substrate 31, a thermoelectric element layer 25 disposed on the substrate 31, and a light emitting part formed on the thermoelectric element layer 25. At this time, the thermoelectric element layer 25 is a plurality of P is spaced apart from each other on top of the heat dissipation unit 110, the heat dissipation unit 110 formed on the substrate 31, as shown in Figure 2 are coupled to the π type It is composed of the cooling material 120 formed on top of the P-type semiconductor and the N-type semiconductor (111, 1120) and the same material as the type semiconductor, N-type semiconductor (111, 112), heat dissipation unit (110).

At this time, by forming the thermoelectric element layer 25 on the substrate 31, the number of masks can be reduced and the manufacturing process of the LED bare chip can be reduced. That is, in the case of configuring the LED bare chip and the thermoelectric element, respectively, a silicon on insulator (SOI) should be performed on the LED wafer and the thermoelectric element wafer. ), The SOI process can be omitted.

When a current supplied from the outside flows to the heat dissipating part 110 of the thermoelectric element layer 25, radiation and absorption of heat occur in the bonded region. In other words, electrons in heterogeneous semiconductors in the junction region have a difference in potential energy, electrons increase kinetic energy to change energy levels, and absorb ambient heat, resulting in a cooling effect.

A light emitting part is formed on the thermoelectric element layer 25, and the light emitting part has a structure as follows. That is, the adhesive layer 27 is positioned on the thermoelectric element layer 25, the metal reflective layer 24 is positioned on the adhesive layer 27, the first semiconductor layer 19 is positioned on the metal reflective layer 24, and the first semiconductor layer ( 19, the active layer 18 is positioned, the second semiconductor layer 16 is positioned on the active layer 18, and the electrode pad 33 is formed on the second semiconductor layer 16. In this case, the first semiconductor layer 19 may be a P-type semiconductor layer, and the second semiconductor layer 16 may be an N-type semiconductor layer.

Therefore, heat is generated by electrons and holes recombined and emit light in the active layer of the vertical LED bare chip. As such, the generated heat is released by the thermoelectric element layer 25.

So far, the present invention has been described with reference to the embodiments. Those skilled in the art will understand that the present invention may be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. Therefore, the scope of the present invention should not be limited to the above-described examples, but should be construed to include various embodiments within the scope and equivalents of the claims.

Claims (11)

Board;
A thermoelectric element layer formed on the substrate; And
A light emitting part formed on the thermoelectric element layer and emitting light; The thermoelectric element layer absorbs and emits heat generated from the light emitting portion, the LED bare chip. The method of claim 1,
The thermoelectric element layer,
A heat dissipation unit bonded on the substrate;
A plurality of P-type semiconductors and N-type semiconductors spaced apart from each other on the heat dissipation unit; And
It has the same material as the heat dissipation unit and includes a cooling unit formed on the upper portion of the P-type semiconductor and N-type semiconductor and bonded to the lower surface of the light emitting portion,
The cooling unit absorbs heat generated from the light emitting unit and transfers the heat to the heat emitting unit. A thermoelectric element layer located on the substrate;
A first semiconductor layer positioned on the thermoelectric element layer and having an opening surface;
An emission layer on the first semiconductor layer;
A second semiconductor layer on the light emitting layer;
A first electrode on the opening surface of the first semiconductor layer; And
And a second electrode disposed on the second semiconductor layer. The method of claim 3, wherein
The thermoelectric element layer is,
A heat dissipation unit bonded on the substrate;
A plurality of P-type semiconductors and N-type semiconductors spaced apart from each other on the heat dissipation unit; And
It has the same material as the heat dissipation portion and includes a cooling unit formed on the P-type semiconductor and the N-type semiconductor and bonded to the lower surface of the first semiconductor layer,
The cooling unit absorbs heat generated from the light emitting unit and transfers the heat to the heat emitting unit. The method of claim 3, wherein
And the first semiconductor layer is an n-type nitride semiconductor layer. The method of claim 3, wherein
The light emitting layer is a quantum well structure or multiple quantum well structure, LED bare chip. The method according to claim 6,
The light emitting layer is made of any one of InGaN / GaN, AlGaN, AlInGaN, LED bare chip. The method of claim 3, wherein
And the second semiconductor layer is a p-type nitride semiconductor layer. The method of claim 3, wherein
Wherein the first electrode is an n-type electrode and the second electrode is a p-type electrode. A thermoelectric element layer overlying the substrate;
An adhesive layer on the thermoelectric element layer;
A metal reflective layer on the adhesive layer;
A first semiconductor layer on the metal reflective layer;
An active layer positioned on the first semiconductor layer;
A second semiconductor layer on the active layer; And
And an electrode pad formed over said second semiconductor layer. The method of claim 10,
Wherein the first semiconductor layer is a P-type semiconductor layer, and the second semiconductor layer is an N-type semiconductor layer.

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