KR20220004002A - Light emitting device - Google Patents

Abstract

Disclosed is a light emitting device exhibiting high heat dissipation efficiency. The light emitting device comprises: a light emitting structure; a first contact electrode and a second contact electrode placed on the light emitting structure and making ohmic contact with first and second conductive-type semiconductor layers, respectively; an insulating layer placed on the light emitting structure and insulating the first contact electrode and the second contact electrode; a first bulk electrode and a second bulk electrode placed on the light emitting structure and electrically connected to the first contact electrode and the second contact electrode, respectively; an insulating support including a first opening and a second opening that cover side surfaces and parts of upper surfaces of the first bulk electrode and the second bulk electrode and partially expose the upper surfaces of the first bulk electrode and the second bulk electrode; and a first pad electrode and a second pad electrode filling, at least in part, the first opening and the second opening, respectively. An area of a region exposed by the first and second openings among the upper surfaces of the first and second bulk electrodes is smaller than a horizontal cross-sectional area of each of the first bulk electrode and the second bulk electrode.

Description

Light emitting device {LIGHT EMITTING DEVICE}

The present invention relates to a light emitting device, and more particularly, to a light emitting device having improved heat dissipation efficiency and mechanical stability.

Recently, as the demand for a small high-power light emitting device increases, the demand for a large-area flip-chip type light emitting device having excellent heat dissipation efficiency is increasing. The electrode of the flip chip light emitting device is directly bonded to the secondary substrate, and since a wire for supplying external power to the flip chip light emitting device is not used, heat dissipation efficiency is very high compared to that of the horizontal light emitting device. Therefore, even when a high-density current is applied, heat can be effectively conducted to the secondary substrate side, and thus the flip-chip type light emitting device is suitable as a high output light emitting source.

In addition, for miniaturization and high output of the light emitting device, a process of packaging the light emitting device in a separate housing is omitted and the demand for a chip scale package using the light emitting device itself as a package is increasing. In particular, since the electrode of the flip-chip type light emitting device can function similarly to the lead of the package, the flip chip type light emitting device can be usefully applied even in such a chip scale package.

When such a chip-scale package type device is used as a high-power light emitting device, a high-density current is applied to the chip-scale package. When a high-density current is applied, heat generated from the light emitting chip increases as much, and accordingly, the heat dissipation efficiency of the high power light emitting device becomes a big factor influencing the reliability of the light emitting device. Therefore, a high-power chip-scale package having high heat dissipation efficiency and excellent mechanical stability and high reliability is required.

An object of the present invention is to provide a light emitting device capable of effectively dissipating heat and having a mechanically stable structure.

A light emitting device according to an aspect of the present invention includes: a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer positioned between the first and second conductivity type semiconductor layers; first and second contact electrodes positioned on the light emitting structure and in ohmic contact with the first and second conductivity-type semiconductor layers, respectively; an insulating layer disposed on the light emitting structure and insulating the first contact electrode and the second contact electrode; first and second bulk electrodes positioned on the light emitting structure and electrically connected to the first and second contact electrodes, respectively; an insulating support covering side surfaces and partial upper surfaces of the first and second bulk electrodes, and including first and second openings for partially exposing upper surfaces of the first and second bulk electrodes; and a first pad electrode and a second pad electrode each at least partially filling the first and second openings; The area is smaller than the horizontal cross-sectional area of the first and second bulk electrodes, respectively.

Accordingly, a light emitting device having improved mechanical stability and heat dissipation characteristics may be provided.

A separation distance between the first and second bulk electrodes may be smaller than a separation distance between the first and second openings.

Furthermore, the separation distance between the first and second bulk electrodes may be 100 μm or less.

In addition, a separation distance between the first and second openings may be 80 μm or more.

The insulating support may include a lower insulating support covering side surfaces of the first and second bulk electrodes, and an upper insulating support covering a portion of upper surfaces of the first and second bulk electrodes, wherein the lower and upper insulating supports include They may be formed of the same material or may be formed of different materials.

Also, the upper insulating support may cover an interface between the first bulk electrode and the lower insulating support and an interface between the second bulk electrode and the lower insulating support.

The lower and upper insulating supports may be formed of different materials, and the upper insulating support may include photoresist or photosolder resist.

The upper surface of the first pad electrode, the upper surface of the second pad electrode, and the upper surface of the insulating support may be positioned side by side at the same height.

The insulating layer may include a first insulating layer and a second insulating layer, the first insulating layer may partially cover the second contact electrode, and the first contact electrode may partially cover the first insulating layer. and the second insulating layer may include a third opening and a fourth opening partially covering the first contact electrode to partially expose the first contact electrode and the second contact electrode.

The first bulk electrode may be electrically connected to the first contact electrode through the third opening, and the second bulk electrode may be electrically connected to the second contact electrode through the fourth opening.

The light emitting device may further include a connection electrode positioned between the second contact electrode and the second bulk electrode.

An upper surface of the connection electrode may be formed of the same material as that of the first contact electrode.

Also, an upper surface of the connection electrode may be positioned at the same height as an upper surface of the first contact electrode.

The light emitting structure may include one or more holes partially exposing the first conductivity-type semiconductor layer, and the first contact electrode may be electrically connected to the first conductivity-type semiconductor layer through the one or more holes. .

A light emitting device according to another aspect of the present invention includes: a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer positioned between the first and second conductivity type semiconductor layers; first and second contact electrodes positioned on the light emitting structure and in ohmic contact with the first and second conductivity-type semiconductor layers, respectively; an insulating layer disposed on the light emitting structure and insulating the first contact electrode and the second contact electrode; first and second bulk electrodes positioned on the light emitting structure and electrically connected to the first and second contact electrodes, respectively; and an insulating support having first and second openings covering side surfaces and partial upper surfaces of the first and second bulk electrodes and partially exposing upper surfaces of the first and second bulk electrodes. and a separation distance between the first and second openings may be greater than a separation distance between the first and second bulk electrodes.

The second conductivity-type semiconductor layer may be a p-type semiconductor layer, and the area of the upper surface of the second bulk electrode exposed by the second opening is equal to that of the portion where the second bulk electrode and the second contact electrode are in contact. may be larger than the area.

In addition, the first conductivity-type semiconductor layer may be an n-type semiconductor layer, and an area of a portion of the upper surface of the first bulk electrode exposed by the first opening is a portion in which the first bulk electrode and the first contact electrode are in contact. may be smaller than the area of

A horizontal cross-sectional area of the first bulk electrode may be greater than a horizontal cross-sectional area of the second bulk electrode.

A light emitting device according to another aspect of the present invention includes: a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer positioned between the first and second conductivity type semiconductor layers; first and second contact electrodes positioned on the light emitting structure and in ohmic contact with the first and second conductivity-type semiconductor layers, respectively; an insulating layer disposed on the light emitting structure and insulating the first contact electrode and the second contact electrode; first and second bulk electrodes positioned on the light emitting structure and electrically connected to the first and second contact electrodes, respectively; and an insulating support having first and second openings covering side surfaces and partial upper surfaces of the first and second bulk electrodes and partially exposing upper surfaces of the first and second bulk electrodes. and the insulating support is located between the first and second bulk electrodes and on a portion of the upper surfaces of the first and second bulk electrodes on the upper side surfaces of the first and second bulk electrodes facing each other.

The insulating support may be positioned on some upper surfaces of the first and second bulk electrodes on the outer side surfaces of the first and second bulk electrodes and on the outer side surfaces of the first and second bulk electrodes.

According to embodiments of the present invention, it is possible to provide a light emitting device including an insulating support including an upper insulating support and a lower insulating support, and covering the side surfaces and some upper surfaces of the bulk electrodes. Accordingly, a light emitting device having high heat dissipation efficiency, excellent mechanical stability, and low probability of contamination by external factors such as moisture may be provided.

1 and 2 are cross-sectional and plan views for explaining a light emitting device according to an embodiment of the present invention.
3 is a cross-sectional view for explaining a light emitting device according to another embodiment of the present invention.
4 and 5 are cross-sectional and plan views for explaining a light emitting device according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art to which the present invention pertains. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. In addition, when one component is described as being “on” or “on” another component, each component is different from each component as well as when each component is “immediately above” or “directly on” the other component. It includes the case where another component is interposed between them. Like reference numerals refer to like elements throughout.

1 and 2 are cross-sectional and plan views for explaining a light emitting device according to an embodiment of the present invention. FIG. 1 shows a cross-section of a region corresponding to line I-I' in FIG. 2 .

1 and 2 , the light emitting device 100 includes a light emitting structure 120 , a first contact electrode 130 , a second contact electrode 140 , insulating layers 150 and 160 , first and second It includes bulk electrodes 171 and 173 and an insulating support 180 . Furthermore, the light emitting device 100 may further include a growth substrate (not shown), a wavelength converter (not shown), and a connection electrode 145 .

The light emitting structure 120 includes a first conductivity type semiconductor layer 121 , an active layer 123 located on the first conductivity type semiconductor layer 121 , and a second conductivity type semiconductor layer ( 125) may be included. The first conductivity type semiconductor layer 121 , the active layer 123 , and the second conductivity type semiconductor layer 125 may include a IIIV series compound semiconductor, for example, a nitride such as (Al, Ga, In)N. It may include a based semiconductor. The first conductivity-type semiconductor layer 121 may include an n-type impurity (eg, Si), and the second conductivity-type semiconductor layer 125 may include a p-type impurity (eg, Mg). have. Also, vice versa. The active layer 123 may include a multiple quantum well structure (MQW).

The light emitting structure 120 may include a region in which the second conductivity type semiconductor layer 125 and the active layer 123 are partially removed and the first conductivity type semiconductor layer 121 is partially exposed. For example, as illustrated, the light emitting structure 120 penetrates through the second conductivity type semiconductor layer 125 and the active layer 123 and exposes the first conductivity type semiconductor layer 121 through at least one hole 120a. ) may be included. In addition, a plurality of holes 120a may be formed, and the shape and arrangement of the holes 120a are not limited to those illustrated. In addition, in the region where the first conductivity-type semiconductor layer 121 is partially exposed, the second conductivity-type semiconductor layer 125 and the active layer 123 are partially removed to form the second conductivity-type semiconductor layer 125 and the active layer ( 123) may be provided.

In addition, the light emitting structure 120 may further include a roughness R formed by increasing the roughness of the lower surface thereof. The roughness (R) may be formed using at least one of wet etching, dry etching, and electrochemical etching, for example, PEC etching or an etching method using an etching solution containing KOH and NaOH, etc. Thus, the roughness (R) can be formed. As the roughness R is formed, it may include protrusions and/or concave portions in a μm to nm scale formed on the surface of the first conductivity type semiconductor layer 121 . By forming roughness on the surface of the light emitting structure 120 , extraction efficiency of the light emitting device may be improved.

In addition, the light emitting structure 120 may further include a growth substrate (not shown) positioned under the first conductivity type semiconductor layer 121 . The growth substrate is not limited as long as it is a substrate capable of growing the light emitting structure 120 . For example, the growth substrate may be a sapphire substrate, a silicon carbide substrate, a silicon substrate, a gallium nitride substrate, an aluminum nitride substrate, or the like. The growth substrate may be separated and removed from the light emitting structure 120 using a known technique.

The second contact electrode 140 is positioned on the second conductivity-type semiconductor layer 125 and may be in ohmic contact with the second conductivity-type semiconductor layer 125 . In addition, the second contact electrode 140 may at least partially cover the upper surface of the second conductivity-type semiconductor layer 125 , and further, may be disposed to entirely cover the upper surface of the second conductivity-type semiconductor layer 125 . have. In addition, the light emitting structure 120 may be formed to cover the upper surface of the second conductivity type semiconductor layer 125 as a single body in the remaining region except for the position where the hole 120a is formed. Accordingly, current may be uniformly supplied to the entire light emitting structure 120 , and current dispersion efficiency may be improved. However, the present invention is not limited thereto.

The second contact electrode 140 may include a material capable of making an ohmic contact with the second conductivity-type semiconductor layer 125 , for example, a metal material and/or a conductive oxide.

When the second contact electrode 140 includes a metal material, the second contact electrode 140 may include a reflective layer and a cover layer covering the reflective layer. As described above, the second contact electrode 140 may be in ohmic contact with the second conductivity type semiconductor layer 125 and may function to reflect light. Accordingly, the reflective layer may include a metal capable of forming an ohmic contact with the second conductivity-type semiconductor layer 125 while having high reflectivity. For example, the reflective layer may include at least one of Ni, Pt, Pd, Rh, W, Ti, Al, Mg, Ag, and Au. In addition, the reflective layer may include a single layer or multiple layers.

The cover layer may prevent mutual diffusion between the reflective layer and other materials, and may prevent other materials from diffusing into the reflective layer from damaging the reflective layer. Accordingly, the cover layer may be formed to cover a lower surface and a side surface of the reflective layer. The cover layer may be electrically connected to the second conductivity-type semiconductor layer 125 together with the reflective layer, thereby serving as an electrode together with the reflective layer. The cover layer may include, for example, Au, Ni, Ti, Cr, or the like, and may include a single layer or multiple layers.

Meanwhile, when the second contact electrode 140 includes a conductive oxide, the conductive oxide may be ITO, ZnO, AZO, IZO, or the like. When the second contact electrode 140 includes a conductive oxide, it may cover the upper surface of the second conductive type semiconductor layer 125 having a larger area than when the second contact electrode 140 includes a metal. That is, the separation distance from the upper edge of the hole 120a to the second contact electrode 140 may be relatively shorter when the second contact electrode 140 is formed of a conductive oxide. In this case, the shortest distance from the portion where the second contact electrode 140 and the second conductivity-type semiconductor layer 125 contact to the portion where the first contact electrode 130 and the first conductivity-type semiconductor layer 121 contact Since can be relatively shorter, the forward voltage (V _f ) of the light emitting device 100 can be reduced.

In addition, when the second contact electrode 140 includes ITO, the first insulating layer 150 includes SiO ₂ , and the first contact electrode 130 includes Ag, ITO/SiO2/Ag stack structure An omnidirectional reflector comprising a may be formed.

The insulating layers 150 and 160 may include a first insulating layer 150 and a second insulating layer 160 . Also, the insulating layers 150 and 160 may partially cover the first and second contact electrodes 130 and 140 . Hereinafter, the first insulating layer 150 will be described first, and the contents related to the second insulating layer 160 will be described later.

The first insulating layer 150 may partially cover the upper surface of the light emitting structure 120 and the second contact electrode 140 . Also, the first insulating layer 150 may cover the side surface of the hole 120a and partially expose the first conductivity type semiconductor layer 121 exposed to the hole 120a. The first insulating layer 150 may include an opening positioned in a portion corresponding to the hole 120a and an opening exposing a portion of the second contact electrode 140 . The first conductivity-type semiconductor layer 121 and the second contact electrode 140 may be partially exposed through the openings.

The first insulating layer 150 may include an insulating material, for example, SiO ₂ , SiN _x , MgF _{2 ,} or the like. Furthermore, the first insulating layer 150 may include multiple layers, and may include a distributed Bragg reflector in which materials having different refractive indices are alternately stacked.

When the second contact electrode 140 includes a conductive oxide, the first insulating layer 150 includes a distributed Bragg reflector to improve the luminous efficiency of the light emitting device 100a. In addition, unlike this, the second contact electrode 140 includes a conductive oxide, and by forming the first insulating layer 150 with a transparent insulating oxide (eg, SiO ₂ ), the second contact electrode 140, An omnidirectional reflector formed by a stacked structure of the first insulating layer 150 and the first contact electrode 130 may be formed.

Furthermore, unlike illustrated, the first insulating layer 150 may further cover at least a portion of the side surface of the light emitting structure 120 . The degree to which the first insulating layer 150 covers the side surface of the light emitting structure 120 may vary depending on whether chip unit isolation is performed in the manufacturing process of the light emitting device. That is, as in the present embodiment, the first insulating layer 150 may be formed to cover only the upper surface of the light emitting structure 120 . On the other hand, after individualizing the wafer into chip units in the manufacturing process of the light emitting device 100 , When the first insulating layer 150 is formed, the first insulating layer 150 may cover the side surface of the light emitting structure 120 .

The first contact electrode 130 may partially cover the light emitting structure 120 , and through the hole 120a and the opening of the first insulating layer 150 positioned at a portion corresponding to the hole 120a, the first contact electrode 130 may be formed. It may be in ohmic contact with the conductive semiconductor layer 121 . The first contact electrode 130 may be formed to entirely cover a portion other than a partial region of the first insulating layer 150 . Also, the first contact electrode 130 may be electrically insulated from the second contact electrode 140 by the first insulating layer 150 .

Since the first contact electrode 130 is formed to entirely cover the upper surface of the light emitting structure 120 except for a partial region, current dissipation efficiency may be further improved. In addition, since the first contact electrode 130 may cover a portion not covered by the second contact electrode 140 , light may be reflected more effectively to improve the luminous efficiency of the light emitting device 100 .

The first contact electrode 130 may make an ohmic contact with the first conductivity-type semiconductor layer 121 and may serve to reflect light. Accordingly, the first contact electrode 130 may be formed of a single layer or multiple layers, and may include a highly reflective metal layer such as an Al layer. The highly reflective metal layer may be formed on an adhesive layer such as Ti, Cr, or Ni. However, the present invention is not limited thereto, and the first contact electrode 130 may include at least one of Ni, Pt, Pd, Rh, W, Ti, Al, Mg, Ag, and Au.

Also, unlike the drawings, the first contact electrode 130 may be formed to cover the side surface of the light emitting structure 120 . When the first contact electrode 130 is also formed on the side surface of the light emitting structure 120 , the light emitted from the side surface from the active layer 123 is reflected upward to increase the ratio of light emitted to the upper surface of the light emitting device 100 . can

Meanwhile, the light emitting device 100 may further include a connection electrode 145 .

The connection electrode 145 may be positioned on the second contact electrode 140 , and may be electrically connected to the second contact electrode 140 through the opening of the first insulating layer 150 . Furthermore, the connection electrode 145 may electrically connect the second contact electrode 140 and the second bulk electrode 173 to each other. In addition, the connection electrode 145 may be formed to partially cover the first insulating layer 150 , and may be spaced apart from the first contact electrode 130 and insulated from each other.

The upper surface of the connection electrode 145 may be formed to have substantially the same height as the upper surface of the first contact electrode 130 . Also, the connection electrode 145 may be formed in the same process as the first contact electrode 130 . Accordingly, the connection electrode 145 and the first contact electrode 130 may include the same material. However, the present invention is not limited thereto, and the connection electrode 145 and the first contact electrode 130 may include different materials.

The second insulating layer 160 may partially cover the first contact electrode 130 , the first opening 160a partially exposing the first contact electrode 130 , and the second contact electrode 140 . A second opening 160b partially exposed may be included. One or more of the first and second openings 160a and 160b may be formed, respectively.

The second insulating layer 160 may include an insulating material, for example, SiO ₂ , SiN _x , MgF _{2 It} may include. Furthermore, the second insulating layer 160 may include multiple layers, and may include a distributed Bragg reflector in which materials having different refractive indices are alternately stacked.

The first bulk electrode 171 and the second bulk electrode 173 may be positioned on the light emitting structure 120 , and the first bulk electrode 171 and the second bulk electrode 173 may each have a first contact electrode ( 130 ) and the second contact electrode 140 . In particular, each of the first bulk electrode 171 and the second bulk electrode 173 may directly contact the first and second contact electrodes 130 and 140 to be electrically connected to each other. In this case, the first bulk electrode 171 and the second bulk electrode 173 may be electrically connected to the first and second contact electrodes 130 and 140 through the first and second openings 160a and 160b, respectively. .

The first bulk electrode 171 and the second bulk electrode 173 may have a thickness of several tens of μm or more, for example, about 70 to 80 μm. Since the bulk electrodes 171 and 173 have a thickness in the above-described range, the light emitting device itself may be used as a chip scale package.

The first bulk electrode 171 and the second bulk electrode 173 may be formed of a single layer or multiple layers, and may include a material having electrical conductivity. For example, each of the first bulk electrode 171 and the second bulk electrode 173 may include Cu, Pt, Au, Ti, Ni, Al, Ag, or the like. Alternatively, it may include sintered metal particles and a non-metallic material interposed between the metal particles.

On the other hand, the separation distance Y between the first bulk electrode 171 and the second bulk electrode 173 may be formed to be less than a predetermined value, and the predetermined value is the light emitting device 100 mounted on a separate substrate. It may be the minimum value between the electrode pads exposed on the mounting surface of the light emitting device 100 required when doing this. Specifically, for example, when soldering is used to mount a predetermined light emitting device on a separate secondary substrate, the distance between the electrode pads exposed on the mounting surface of the predetermined light emitting device is generally about 250 to prevent short circuit. It is required to be greater than or equal to ㎛. In addition, when eutectic bonding is used to mount a predetermined light emitting device on a separate secondary substrate, the distance between electrode pads exposed on the mounting surface of the predetermined light emitting device is generally about approx. It is required to be 80 µm or more. According to the present embodiment, the separation distance Y between the first bulk electrode 171 and the second bulk electrode 173 may be less than or equal to this predetermined value, for example, may be less than or equal to about 250 µm, and may be less than or equal to about 100 µm. and, further, it may be about 80 μm or less. By setting the separation distance Y between the first bulk electrode 171 and the second bulk electrode 173 to a predetermined value or less, the horizontal cross-sectional area and volume of the first bulk electrode 171 and the second bulk electrode 173 are relative can be made larger, so that heat generated when the light emitting device 100 is driven can be effectively dissipated. In this regard, it will be described later in further detail.

In addition, the first bulk electrode 171 and the second bulk electrode 173 may have different volumes, and the horizontal cross-sectional area of the first bulk electrode 171 is greater than the horizontal cross-sectional area of the second bulk electrode 173 . can be large In this case, the first conductivity-type semiconductor layer 121 may be an n-type semiconductor layer, and the second conductivity-type semiconductor layer 125 may be a p-type semiconductor layer. In general, heat generated when the light emitting device 100 is driven is more concentrated on the first bulk electrode 171 serving as an n-type electrode than on the second bulk electrode 173 serving as a p-type electrode. Accordingly, the heat dissipation efficiency of the light emitting device 100 may be improved by making the horizontal cross-sectional area of the first bulk electrode 171 larger than the horizontal cross-sectional area of the second bulk electrode 173 .

The insulating support 180 is positioned on the light emitting structure 120 and partially covers side surfaces of the bulk electrodes 171 and 173 and upper surfaces of the bulk electrodes 171 and 173 . In addition, the insulating support 180 may include a third opening 180a and a fourth opening 180b that partially expose the top surfaces of the first bulk electrode 171 and the second bulk electrode 173 .

The insulating support 180 may include a lower insulating support 181 and an upper insulating support 183 , and the lower insulating support 181 may surround the side surfaces of the bulk electrodes 171 and 173 , and may include upper insulating support. The support 183 may partially cover the upper surfaces of the bulk electrodes 171 and 173 . Also, the upper insulating support 183 may cover the interface between the lower insulating support 181 and the bulk electrodes 171 and 173 .

The insulating support 180 has electrical insulation and covers side surfaces of the first and second bulk electrodes 171 and 173 to effectively insulate them from each other. At the same time, the insulating support 180 may serve to support the first bulk electrode 171 and the second bulk electrode 173 .

The upper surfaces of the bulk electrodes 171 and 173 are partially covered by the upper insulating support 183 , and the areas of the exposed portions 171a and 173a among the upper surfaces of the first and second electrodes 171 and 173 are respectively the second The horizontal cross-sectional area of the first bulk electrode 171 and the horizontal cross-sectional area of the second bulk electrode 173 may be smaller than that of the second bulk electrode 173 . In particular, the upper insulating support 183 may be positioned on top surfaces of the bulk electrodes 171 and 173 around side surfaces of the first bulk electrode 171 and the second bulk electrode 173 opposite to each other. Therefore, the separation distance X between the exposed upper surface 171a of the first bulk electrode 171 and the exposed upper surface 173a of the second bulk electrode 173 is the first bulk electrode 171 and the second bulk electrode. (173) is greater than the separation distance (Y).

Specifically, the light emitting device 100 is formed by forming a conductive material (eg, solder, conductive adhesive, eutectic material, etc.) between the exposed upper surfaces 171a and 173a and a separate substrate. ) and the separate substrate, the light emitting device 100 can be mounted on the separate substrate. In order to prevent an electrical short from occurring between the bulk electrodes 171 and 173 by the conductive material formed for adhesion, the separation distance X between the exposed upper surfaces 171a and 173a as described above is a predetermined value. It is required to be more than a number. According to the present invention, the insulating support 180 is formed to partially cover the upper surfaces of the bulk electrodes 171 and 173 , so that the exposed upper surface 171a of the first bulk electrode 171 and the second bulk electrode 173 are exposed. ) may be formed so that the separation distance X between the exposed upper surfaces 173a is greater than the separation distance Y between the first bulk electrode 171 and the second bulk electrode 173 . Accordingly, the separation distance X is formed to be greater than a predetermined value that can prevent an electrical short from occurring between the bulk electrodes 171 and 173, and at the same time, the separation distance Y between the bulk electrodes 171 and 173 ) may be formed below a predetermined value to prevent an electrical short from occurring between the bulk electrodes 171 and 173 . Accordingly, it is possible to improve the heat dissipation efficiency of the light emitting device 100 and effectively prevent an electric short from occurring during the mounting process of the light emitting device 100 .

The separation distance X between the exposed upper surface 171a of the first bulk electrode 171 and the exposed upper surface 173a of the second bulk electrode 173 is not limited, but the light emitting device 100 is separately separated by soldering. The separation distance (X) may be about 250 μm or more when mounted on a substrate of can However, the present invention is not limited thereto.

In addition, in the upper insulating support 183 , the separation distance X between the exposed upper surface 171a of the first bulk electrode 171 and the exposed upper surface 173a of the second bulk electrode 173 is formed to be greater than or equal to a predetermined value. It is sufficient if the bulk electrodes 171 and 173 are disposed in the upper peripheral region of the side opposite to each other, and the arrangement of the bulk electrodes 171 and 173 in the other regions is not limited. For example, as shown in FIGS. 1 and 2 , the insulating support 180 positioned between the first and second bulk electrodes 171 and 173 may have a 'T' cross-section. Further, the insulating support 180 covering the outer side surfaces of the first and second bulk electrodes 171 and 173 may have a 'L' shape in its cross section.

In addition, the insulating support 180 and the bulk electrodes 171 and 173 may be formed of different materials. In particular, the insulating support 180 may include an insulating polymer and/or an insulating ceramic, and the bulk electrodes (171, 173) may include a metallic material. Accordingly, peeling or cracking may occur at the interface between the insulating support 180 and the bulk electrodes 171 and 173, and damage due to stress and strain that may occur due to bonding of different materials may occur. When the insulating support 180 and/or the bulk electrodes 171 and 173 are damaged, the light emitting structure 120 may be contaminated, and further, cracks may occur in the light emitting structure 120 , and thus the light emitting device 100 . ) may be less reliable. According to embodiments of the present invention, the insulating support 180 is formed to partially cover the side surfaces of the bulk electrodes 171 and 173 and the upper surfaces of the bulk electrodes 171 and 173, so that the insulating support 180 and Mechanical stability between the bulk electrodes 171 and 173 may be improved. Accordingly, the reliability of the light emitting device 100 may be improved.

In addition, since the mechanical stability of the light emitting device 100 is improved, it is possible to prevent the light emitting structure 120 from being damaged in the process of separating the growth substrate (not shown) from the light emitting structure 120 .

Furthermore, the lower insulating support 181 and the upper insulating support 183 may be formed of the same material or different materials.

When the lower insulating support 181 and the upper insulating support 183 are formed of the same material, the insulating support 180 may include, for example, a material such as EMC (Epoxy Molding Compound) or a Si resin. . In addition, the insulating support 180 may include light reflective and light scattering particles such as _{TiO 2 particles.}

When the lower insulating support 181 and the upper insulating support 183 are formed of different materials, the upper insulating support 183 may be formed of a material having low brittleness and/or low hygroscopicity compared to the lower insulating support 181. can For example, the lower insulating support 181 may include a material such as EMC (Epoxy Molding Compound) or Si resin, and the upper insulating support 183 may include a photoresist (PR) and/or a photo-solder resist (PSR). It may contain substances such as

Since the upper insulating support 183 is formed of a material having a relatively low brittleness, the probability of cracking or cracking is lower than that of the lower insulating support 181 , and thus between the lower insulating support 181 and the bulk electrodes 171 and 173 . Penetration of external contaminants through the interface can be prevented. In addition, since the upper insulating support 183 is formed of a material having a relatively low hygroscopicity, it is possible to prevent external contaminants from penetrating through the interface between the lower insulating support 181 and the bulk electrodes 171 and 173 . For example, when the lower insulating support 181 is formed of a material with high hygroscopicity such as EMC, the light emitting device 100 can be more effectively protected from moisture by the upper insulating support 183 formed of a material such as PSR. have. In particular, when the upper insulating support 183 is formed to cover the interface between the lower insulating support 181 and the bulk electrodes 171 and 173 , the above-described light emitting device 100 protection function can be more effectively exhibited.

Meanwhile, an area of the exposed upper surface 171a of the first bulk electrode 171 may be smaller than an area of a region where the first bulk electrode 171 and the first contact electrode 130 come into contact, and the second bulk electrode 173 ), an area of the exposed upper surface 173a may be greater than an area of a region where the second bulk electrode 173 and the second contact electrode 140 contact each other. In this case, the horizontal cross-sectional area of the first bulk electrode 171 may be greater than the horizontal cross-sectional area of the second bulk electrode 173 .

That is, the heat dissipation efficiency of the light emitting device 100 may be improved by making the horizontal cross-sectional area of the first bulk electrode 171 larger than the horizontal cross-sectional area of the second bulk electrode 173 . At the same time, the area of the exposed upper surface 171a of the first bulk electrode 171 and the second bulk electrode 173 are greater than the ratio between the horizontal cross-sectional area of the first bulk electrode 171 and the horizontal cross-sectional area of the second bulk electrode 173 . By lowering the ratio between the areas of the exposed upper surfaces 173a, the areas of the upper surfaces 171a and 173a exposed to the surface on which the light emitting device 100 is mounted may be substantially similar. Accordingly, the light emitting device 100 with improved heat dissipation efficiency can be provided without changing the process of mounting the light emitting device 100 on a separate substrate.

In some embodiments, unlike illustrated, the insulating support 180 may cover up to the side surface of the light emitting structure 120 , and in this case, the light emission angle of the light emitted from the light emitting structure 120 may vary. For example, when the insulating support 180 further covers at least a portion of the side surface of the light emitting structure 120 , some of the light emitted to the side of the light emitting structure 120 may be reflected to the lower surface of the light emitting structure 120 . . In this way, by adjusting the region in which the insulating support 180 is disposed, the light emission angle of the light emitting device 100 can be adjusted.

On the other hand, the light emitting device 100 may further include a wavelength conversion unit (not shown), the wavelength of the light emitted from the light emitting structure 120 by the wavelength conversion unit is converted to a light emitting device capable of implementing various colors of light. (100) may be provided. For example, when the wavelength converter includes phosphors emitting red and green light and blue light is emitted from the light emitting structure 120 , the light emitting device 100 may emit white light. Accordingly, a miniaturized high-power wafer-level white light emitting device can be provided.

The disposition position of the wavelength converter is not limited, and for example, may be formed on the lower surface of the light emitting structure 120 , and further, may be formed to further cover the side surface of the light emitting structure 120 .

3 is a cross-sectional view for explaining a light emitting device according to another embodiment of the present invention.

The light emitting device 200 of FIG. 3 is substantially similar to the light emitting device 100 described with reference to FIGS. 1 and 2 , and is different in that it further includes a first pad electrode 191 and a second pad electrode 193 . there is Hereinafter, the light emitting device 200 of the present embodiment will be described with a focus on differences, and detailed description of the same configuration will be omitted.

1 and 2 , the light emitting device 100 includes a light emitting structure 120 , a first contact electrode 130 , a second contact electrode 140 , insulating layers 150 and 160 , first and second It includes bulk electrodes 171 and 173 , an insulating support 180 , a first pad electrode 191 , and a second pad electrode 193 . Furthermore, the light emitting device 100 may further include a growth substrate (not shown), a wavelength converter (not shown), and a connection electrode 145 .

The first pad electrode 191 and the second pad electrode 193 may be positioned on the first bulk electrode 171 and the second bulk electrode 173 , respectively, and the third electrode of the insulating support 180 , respectively. The opening 180a and the fourth opening 180b may be at least partially filled. Accordingly, the first pad electrode 191 and the second pad electrode 193 form the exposed upper surface 171a of the first bulk electrode 171 and the exposed upper surface 173a of the second bulk electrode 173, respectively. can be covered Accordingly, the separation distance between the first and second pad electrodes 191 and 193 is the separation distance (X) between the exposed upper surface 171a of the first bulk electrode 171 and the exposed upper surface 173a of the second bulk electrode 173 . ) can be matched.

Also, as illustrated, upper surfaces of the first pad electrode 191 and the second pad electrode 193 may be positioned flush with the upper surface of the insulating support 180 at substantially the same height. In this case, the upper surface of the light emitting device 100 may be formed to be substantially flat.

The first and second pad electrodes 191 and 193 may be formed using a method such as plating to fill the openings of the insulating support 180 . Thereafter, the first and second pad electrodes 191 and 193 and the insulating support 180 are partially removed using a physical and/or chemical method, for example, lapping or CMP, by using this method to partially remove the first pad electrode ( 191 ) and the upper surface of the second pad electrode 193 may be formed to be parallel to the upper surface of the insulating support 180 at substantially the same height.

The first pad electrode 191 and the second pad electrode 193 may include a conductive material, particularly, a metallic material, for example, Ni, Pt, Pd, Rh, W, Ti, Al, Au, Sn. , Cu, Ag, Bi, In, Zn, Sb, Mg, Pb, and the like. The first and second pad electrodes 191 and 193 may include substantially the same material as the bulk electrodes 171 and 173 or may be formed of different materials. The first and second pad electrodes 191 and 193 may be formed using a deposition or plating method, for example, may be formed using electroless plating.

Since the light emitting device 200 further includes the first and second pad electrodes 191 and 193 , the upper surface of the light emitting device 200 (the light emitting device 200 may be a surface on which the light emitting device 200 is mounted on a separate substrate) is generally flat. can be formed. Accordingly, the process of mounting the light emitting device 200 on a separate substrate may be facilitated.

In addition, in the process of separating the growth substrate (not shown) from the light emitting structure 120 during the manufacturing process of the light emitting device 200 , when there is a step on the surface opposite to the surface on which the growth substrate is located, light is emitted during separation of the growth substrate The probability that a crack or breakage occurs in the structure 120 is increased. According to the present embodiment, the surface positioned opposite to the surface on which the growth substrate is positioned is formed to be substantially flat by the first and second pad electrodes 191 and 193, so that the light emitting structure 120 is attached to the light emitting structure 120 in the process of separating the growth substrate. It can prevent damage from occurring. Accordingly, the yield of the light emitting device 200 manufacturing process may be improved, and reliability of the manufactured light emitting device 200 may be improved.

4 and 5 are cross-sectional and plan views for explaining a light emitting device according to another embodiment of the present invention.

The structure of the light emitting structure 120 of the light emitting device 300 of this embodiment is different from that of the light emitting device 200 of FIGS. 1 and 2 . Accordingly, there is a difference in the mutual structural relationship of the other remaining components, and the following will be described in detail focusing on the difference. A detailed description of the same configuration will be omitted.

4 (a) is a plan view of the light emitting device according to the present embodiment, (b) is a plan view for explaining the position of the hole (120h) and the first opening (160a) and the second opening (160b), , FIG. 5 is a cross-sectional view showing a cross section of a region corresponding to line IIII in FIGS. 4A and 4B.

4 and 5 , the light emitting device 300 includes a light emitting structure 120 , a first contact electrode 130 , a second contact electrode 140 , insulating layers 150 and 160 , first and second It includes bulk electrodes 171 and 173 and an insulating support 180 . Furthermore, the light emitting device 300 may further include a growth substrate (not shown), a wavelength converter (not shown), a first pad electrode 191 , and a second pad electrode 193 .

The light emitting structure 120 may include a region in which the second conductivity type semiconductor layer 125 and the active layer 123 are partially removed and the first conductivity type semiconductor layer 121 is partially exposed. For example, as shown, the light emitting structure 120 has a plurality of holes 120h penetrating through the second conductivity type semiconductor layer 125 and the active layer 123 to expose the first conductivity type semiconductor layer 121 . may include The holes 120h may be positioned substantially regularly throughout the light emitting structure 120 . However, the present invention is not limited thereto, and the arrangement shape and number of the holes 120h may be variously modified.

In addition, the shape in which the first conductivity type semiconductor layer 121 is exposed is not limited to the shape of the hole 120h. For example, the exposed region of the first conductivity-type semiconductor layer 121 may be formed in the form of a line or a complex of holes and lines.

The second contact electrode 140 may be positioned on the second conductivity-type semiconductor layer 125 to make an ohmic contact. The second contact electrode 140 may be disposed to entirely cover the upper surface of the second conductivity-type semiconductor layer 125 , and further, may be formed to almost completely cover the upper surface of the second conductivity-type semiconductor layer 125 . have. The second contact electrode 140 may be formed as a single body throughout the light emitting structure 120 . In this case, the second contact electrode 140 may include opening regions corresponding to positions of the plurality of holes 120h. can Accordingly, current may be uniformly supplied to the entire light emitting structure 120 , and current dispersion efficiency may be improved.

However, the present invention is not limited thereto, and the second contact electrode 140 may be formed of a plurality of unit units.

The first insulating layer 150 may partially cover the upper surface of the light emitting structure 120 and the second contact electrode 140 . The first insulating layer 150 may cover side surfaces of the plurality of holes 120h, and may include openings for partially exposing the first conductivity-type semiconductor layer 121 positioned on the lower surface of the holes 120h. Accordingly, the opening may be positioned to correspond to a position where the plurality of holes 120h are disposed. Also, the first insulating layer 150 may include an opening exposing a portion of the second contact electrode 140 . Furthermore, the first insulating layer 150 may further cover at least a portion of the side surface of the light emitting structure 120 .

The first contact electrode 130 may partially cover the light emitting structure 120 , and through the openings of the holes 120h and the first insulating layer 150 positioned at portions corresponding to the holes 120h, the first contact electrode 130 may It may be in ohmic contact with the conductive semiconductor layer 121 . Also, unlike the drawings, the first contact electrode 130 may be formed to cover the side surface of the light emitting structure 120 .

The second insulating layer 160 may partially cover the first contact electrode 130 , the first opening 160a partially exposing the first contact electrode 130 , and the second contact electrode 140 . A second opening 160b partially exposed may be included. One or more of the first and second openings 160a and 160b may be formed, respectively. In addition, the openings 160a and 160b may be located at opposite sides of each other to be biased, respectively.

The first bulk electrode 171 and the second bulk electrode 173 may be positioned on the light emitting structure 120 , and the first bulk electrode 171 and the second bulk electrode 173 may each have a first contact electrode ( 130 ) and the second contact electrode 140 .

Meanwhile, the separation distance Y between the first bulk electrode 171 and the second bulk electrode 173 may be formed to be less than or equal to a predetermined value, for example, may be less than or equal to about 250 µm, and further, may be less than or equal to about 80 µm. In addition, the first bulk electrode 171 and the second bulk electrode 173 may have different volumes, and the horizontal cross-sectional area of the first bulk electrode 171 is greater than the horizontal cross-sectional area of the second bulk electrode 173 . can be large

The insulating support 180 is positioned on the light emitting structure 120 and partially covers side surfaces of the bulk electrodes 171 and 173 and upper surfaces of the bulk electrodes 171 and 173 . In addition, the insulating support 180 may include a third opening 180a and a fourth opening 180b that partially expose the top surfaces of the first bulk electrode 171 and the second bulk electrode 173 . The insulating support 180 may include a lower insulating support 181 and an upper insulating support 183 , and the lower insulating support 181 may surround the side surfaces of the bulk electrodes 171 and 173 , and may include upper insulating support. The support 183 may partially cover the upper surfaces of the bulk electrodes 171 and 173 . Also, the upper insulating support 183 may cover the interface between the lower insulating support 181 and the bulk electrodes 171 and 173 .

The upper surfaces of the bulk electrodes 171 and 173 are partially covered by the upper insulating support 183 , and the areas of the exposed portions 171a and 173a among the upper surfaces of the first and second electrodes 171 and 173 are respectively the second The horizontal cross-sectional area of the first bulk electrode 171 and the horizontal cross-sectional area of the second bulk electrode 173 may be smaller than that of the second bulk electrode 173 . In particular, the upper insulating support 183 may be positioned on top surfaces of the bulk electrodes 171 and 173 around side surfaces of the first bulk electrode 171 and the second bulk electrode 173 opposite to each other. Therefore, the separation distance X between the exposed upper surface 171a of the first bulk electrode 171 and the exposed upper surface 173a of the second bulk electrode 173 is the first bulk electrode 171 and the second bulk electrode. (173) is greater than the separation distance (Y).

The separation distance X between the exposed upper surface 171a of the first bulk electrode 171 and the exposed upper surface 173a of the second bulk electrode 173 is not limited, but the light emitting device 100 is separately separated by soldering. The separation distance (X) may be about 250 μm or more when mounted on a substrate of can However, the present invention is not limited thereto.

Furthermore, the lower insulating support 181 and the upper insulating support 183 may be formed of the same material or different materials.

In particular, when the lower insulating support 181 and the upper insulating support 183 are formed of different materials, the upper insulating support 183 is made of a material having low brittleness and/or low hygroscopicity compared to the lower insulating support 181 . can be formed. For example, the lower insulating support 181 may include a material such as EMC (Epoxy Molding Compound) or Si resin, and the upper insulating support 183 may include a photoresist (PR) and/or a photo-solder resist (PSR). It may contain substances such as

Meanwhile, an area of the exposed upper surface 171a of the first bulk electrode 171 may be smaller than an area of a region where the first bulk electrode 171 and the first contact electrode 130 come into contact, and the second bulk electrode 173 ), an area of the exposed upper surface 173a may be greater than an area of a region where the second bulk electrode 173 and the second contact electrode 140 contact each other. In this case, the horizontal cross-sectional area of the first bulk electrode 171 may be greater than the horizontal cross-sectional area of the second bulk electrode 173 .

The first pad electrode 191 and the second pad electrode 193 may be positioned on the first bulk electrode 171 and the second bulk electrode 173 , respectively, and the third electrode of the insulating support 180 , respectively. The opening 180a and the fourth opening 180b may be at least partially filled. Accordingly, the first pad electrode 191 and the second pad electrode 193 form the exposed upper surface 171a of the first bulk electrode 171 and the exposed upper surface 173a of the second bulk electrode 173, respectively. can be covered Accordingly, the separation distance between the first and second pad electrodes 191 and 193 is the separation distance Y between the exposed upper surface 171a of the first bulk electrode 171 and the exposed upper surface 173a of the second bulk electrode 173 . ) can be matched. Also, as illustrated, upper surfaces of the first pad electrode 191 and the second pad electrode 193 may be positioned flush with the upper surface of the insulating support 180 at substantially the same height. In this case, the upper surface of the light emitting device 100 may be formed to be substantially flat.

In the above, various embodiments of the present invention have been described, but the present invention is not limited to each of the above-described embodiments and features. The invention changed through the combination and substitution of technical features described in the embodiments is also included in the scope of the present invention, and various modifications and changes are possible within the scope without departing from the technical spirit of the claims of the present invention.

Claims (13)

a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer positioned between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer;
a first contact electrode and a second contact electrode positioned on the light emitting structure and in ohmic contact with the first conductivity-type semiconductor layer and the second conductivity-type semiconductor layer, respectively;
an insulating layer disposed on the light emitting structure and insulating the first contact electrode and the second contact electrode;
first and second bulk electrodes positioned on the light emitting structure and electrically connected to the first and second contact electrodes, respectively;
first and second pad electrodes electrically connected to the first and second bulk electrodes, respectively;
a first insulating support covering side surfaces of the first and second bulk electrodes and exposing upper surfaces of the first and second bulk electrodes; and
a second insulating support covering side surfaces of the first pad electrode and the second pad electrode;
The first insulating support and the second insulating support are formed of different materials,
A light emitting device in which the width of the second insulating support between the first and second pad electrodes is wider than the width of the first insulating support between the first and second bulk electrodes.
The method according to claim 1,
The insulating layer includes a first opening and a second opening partially exposing the first contact electrode and the second contact,
A distance between the first bulk electrode and the second bulk electrode is smaller than a distance between the first and second openings.
3. The method according to claim 2,
A distance between the first bulk electrode and the second bulk electrode is 250 μm or less.
3. The method according to claim 2,
A distance between the first opening and the second opening is 80 μm or more.
The method according to claim 1,
The second insulating support is a light emitting device covering an interface between the first bulk electrode and the first insulating support and an interface between the second bulk electrode and the first insulating support.
The method according to claim 1,
The light emitting structure includes one or more holes partially exposing the first conductivity-type semiconductor layer,
The first contact electrode is a light emitting device electrically connected to the first conductivity-type semiconductor layer through the one or more holes.
The method according to claim 1,
The first conductivity type semiconductor layer, the active layer and the second conductivity type semiconductor layer include a IIIV series compound semiconductor,
The first conductivity-type semiconductor layer includes an n-type impurity,
The second conductivity type semiconductor layer is a light emitting device including a p-type impurity.
The method according to claim 1,
The first contact electrode is a light emitting device formed to cover a side surface of the light emitting structure and a portion of the light emitting structure not covered by the second contact electrode.
The method according to claim 1,
Each of the first bulk electrode and the second bulk electrode includes at least one of Cu, Pt, Au, Ti, Ni, Al, and Ag.
10. The method of claim 9,
The first bulk electrode and the second bulk electrode have a thickness of 80 μm or less.
The method according to claim 1,
A light emitting device in which a horizontal cross-sectional area of the first bulk electrode is larger than a horizontal cross-sectional area of the second bulk electrode.
The method according to claim 1,
The first insulating support is a light emitting device including at least one of EMC (Epoxy Molding Compound) and Si resin.
The method according to claim 1,
The outer surface of the first insulating support and the outer surface of the second insulating support are located in parallel with the light emitting device.

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