Light emitting diode module for surface mount technology and method of manufacturing the same
Provided is a light emitting diode (LED) in which a side surface of a reflective metal layer has a predetermined angle, and occurrence of cracks in a conductive barrier layer formed on the reflective metal layer can be prevented. Also, an LED module using LEDs is disclosed. A reflection pattern electrically connected to a second semiconductor layer is partially exposed by patterning a first insulating layer. Accordingly, a first pad is formed through the partially opened first pad region. Also, a conductive reflection layer electrically connected to a first semiconductor layer forms a second pad region formed by patterning a second insulating layer. A second pad is formed on the second pad region.
1. A light emitting diode (LED) module comprising:
an LED unit having a stacked structure including a first semiconductor layer, an active layer, a second semiconductor layer, and a reflection pattern that are formed over a substrate, and including a mesa region exposing at least a portion of a surface of the first semiconductor layer;
a first insulating layer formed over selected portions of the stacked structure to expose the mesa region, the first insulating layer patterned on the reflection pattern to form a first pad region;
a conductive reflection layer formed over the first insulating layer and the first semiconductor layer exposed in the mesa region;
a second insulating layer formed over the conductive reflection layer, the second insulating layer patterned on the conductive reflection layer to form a second pad region;
a first pad formed over the first pad region; and
a second pad formed over the second pad region.
2. The LED module of claim 1 , wherein the patterned first insulating layer exposes selective portions of the reflection pattern.
3. The LED module of claim 1 , wherein the patterned second insulating layer exposes selective portions of the conductive reflection layer.
4. The LED module of claim 1 , wherein when a wavelength of light generated in the active layer is λ, a thickness of the first insulating layer is an integer multiple of λ/4.
5. The LED module of claim 1 , wherein the reflection pattern comprises:
a reflective metal layer formed over the second semiconductor layer and configured to reflect light; and
a conductive barrier layer configured to cover the reflective metal layer and extend over the second semiconductor layer.
6. The LED module of claim 3 , wherein an area of the exposed reflection pattern is greater than an area of the exposed conductive reflection layer.
7. The LED module of claim 3 , wherein the first and second pad regions include holes and the number of holes in the first pad region is equal to or greater than the number of holes in the second pad region.
8. The LED module of claim 3 , wherein an area of the first pad is greater than an area of the second pad.
9. The LED module of claim 5 , wherein the conductive barrier layer has a thickness depending on an underlying layer.
10. The LED module of claim 5 , wherein a side surface of the reflective metal layer forms an inclined angle of about 5° to about 45° with respect to a surface of the second semiconductor layer.
11. A method of manufacturing a light emitting diode (LED) module, comprising:
forming a stacked structure including a first semiconductor layer, an active layer, a second semiconductor layer, and a reflective pattern;
forming a first insulating layer over selected portions of the stacked structure to expose portions of the reflection pattern and portions of the first semiconductor layer, wherein the exposed portions of the reflection pattern and the first insulating layer over the reflection pattern define a first pad region;
forming a conductive reflection layer over the first insulating layer to electrically connect with the exposed portions of the first semiconductor layer, and expose the first pad region;
forming a second insulating layer over the conductive reflection layer to expose portions of the reflection pattern and portions of the conductive reflection layer, wherein the exposed portions of the conductive reflection layer and the second insulating layer over the conductive reflection layer define a second pad region; and
forming a first pad over the first pad region and forming a second pad over the second pad region.
12. The method of claim 11 , wherein the forming of the stacked structure includes:
forming the first semiconductor layer, the active layer, and the second semiconductor layer over the substrate;
etching the second semiconductor layer and the active layer to form a mesa region exposing at least a portion of a surface of the first semiconductor layer;
forming a photoresist pattern on the mesa region, the photoresist pattern having an overhang structure;
forming a reflective metal layer on a surface of the second semiconductor layer exposed by the photoresist pattern; and
forming a conductive barrier layer over the reflective metal layer, wherein the conductive barrier layer extends over the second semiconductor layer.
13. The method of claim 11 , wherein an area of the reflection pattern exposed through the first pad region is greater than an area of the conductive reflection layer exposed through the second pad region.
14. The method of claim 11 , wherein, the forming of the first insulating layer includes forming the first insulating layer on a side surface of the LED module to have a thickness of an integer multiple of λ/4, when a wavelength of light generated in the active layer λ.
15. A light emitting diode (LED) module comprising:
a stacked structure including a first semiconductor layer, an active layer, a second semiconductor layer, and a reflection pattern that are formed over a substrate;
a first pad region formed over the reflection pattern to include a first insulation layer patterned to expose at least a portion of the reflection pattern;
a conductive reflection layer formed over the stacked structure;
a second pad region formed over the conductive reflection layer to include a second insulation layer patterned to expose at least a portion of the conductive reflection layer;
a first pad disposed over the first pad region to electrically connect the first pad region to the second semiconductor layer; and
a second pad disposed over the second pad region to electrically connect the second pad region to the first semiconductor layer.
16. The LED module of claim 15 , wherein a size of the first pad is greater than a size of the second pad.
17. The LED module of claim 15 , wherein the first and second pad regions include holes defined by the pattered first and second insulation layers, respectively, and the number of the holes in the first pad region is greater than the number of the holes in the second pad region.
18. The LED module of claim 15 , wherein the active layer, the second semiconductor layer, and the reflection pattern have an inclined sidewall.
19. The LED module of claim 15 , comprising:
a pad barrier layer formed over at least one of the first pad of the second pad.
20. The LED module of claim 15 , comprising:
a phosphor layer disposed over at least one surface of the substrate.