Light-emitting element package and its application

Abstract

To provide a light-emitting element package.SOLUTION: A light-emitting element package includes a printed circuit board having a front surface and a rear surface, at least one light-emitting element provided on the front surface and emitting light in a direction toward the front surface, and a molding layer provided on the printed circuit board and surrounding the light-emitting element. The light-emitting element includes a light-emitting structure provided on the printed circuit board, a substrate provided on the light-emitting structure, and a number of bump electrodes provided between the light-emitting structure and the printed circuit board. The molding layer may cover an upper surface of the substrate and may have a microscopic uneven part on a surface of the molding layer that is exposed to the outside.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a light-emitting element package and an application to which the same is applied. [Background technology]

[0002] In recent years, a variety of devices using light-emitting diodes (LEDs) have been developed. Examples of devices that use light-emitting diodes as a light source include general lighting and display devices. Each device using light-emitting diodes is obtained by forming individually grown red (R), green (G), and blue (B) light-emitting diode (LED) structures on a final substrate.

[0003] For such light-emitting diodes to be applied to a variety of devices, they need to have a simple structure and be easy to manufacture. [Overview of the project] [Problems that the invention aims to solve]

[0004] One embodiment of the present invention aims to provide a light-emitting element package and its applications that have a simple structure and a simple manufacturing method. [Means for solving the problem]

[0005] A light-emitting element package according to one embodiment of the present invention includes a printed circuit board having a front and a back surface, at least one light-emitting element provided on the front surface and emitting light in a direction toward the front surface, and a molding layer provided on the printed circuit board and surrounding the light-emitting element, wherein the light-emitting element includes a light-emitting structure provided on the printed circuit board, a substrate provided on the light-emitting structure, and a number of bump electrodes provided between the light-emitting structure and the printed circuit board. The molding layer covers the upper surface of the substrate, and the surface exposed to the outside of the molding layer may be provided with fine irregularities.

[0006] In one embodiment of the present invention, the fine uneven surface can be manufactured by at least one of plasma treatment, micro-sandblasting, pattern transfer, dry polishing, and wet etching.

[0007] In one embodiment of the present invention, the molding layer may have a substantially flat upper surface.

[0008] In one embodiment of the present invention, the molding layer can reflect, scatter, or absorb a portion of the external light.

[0009] In one embodiment of the present invention, the molding layer may be filled in at least a portion of the space between the light-emitting structure and the printed circuit board.

[0010] In one embodiment of the present invention, the molding layer may have an external light reflectance, external light scattering rate, or external light absorption rate of about 50% or more.

[0011] In one embodiment of the present invention, the molding layer may have a black color.

[0012] In one embodiment of the present invention, the printed circuit board includes upper electrodes provided on the front surface, lower electrodes provided on the back surface, and via electrodes connecting the upper electrodes to the lower electrodes, and each bump electrode may be connected to the corresponding upper electrode.

[0013] In one embodiment of the present invention, the distance between two adjacent lower electrodes may be greater than the distance between two adjacent upper electrodes.

[0014] In one embodiment of the present invention, the light-emitting elements may be provided in multiple units. For example, four of the light-emitting elements may be provided, and each light-emitting structure of the light-emitting elements may be sequentially stacked on the substrate, emitting light in different wavelength bands, and including multiple epitaxial stacks in which the light-emitting regions overlap each other.

[0015] In one embodiment of the present invention, the plurality of epitaxial stacks may include a first epitaxial stack that emits a first light, a second epitaxial stack provided on the first epitaxial stack that emits a second light in a different wavelength band than the first light, and a third epitaxial stack provided on the second epitaxial stack that emits a third light in a different wavelength band than the first and second light.

[0016] In one embodiment of the present invention, each of the first to third epitaxial stacks may include a p-type semiconductor layer, an n-type semiconductor layer, and an active layer provided between the p-type semiconductor layer and the n-type semiconductor layer.

[0017] In one embodiment of the present invention, each bump electrode may include a first bump electrode connected to the p-type semiconductor layer of the first epitaxial stack, a second bump electrode connected to the p-type semiconductor layer of the second epitaxial stack, a third bump electrode connected to the p-type semiconductor layer of the third epitaxial stack, and a fourth bump electrode connected to each of the n-type semiconductor layers of the first to third epitaxial stacks.

[0018] In one embodiment of the present invention, each light-emitting element includes a first to fourth light-emitting element, each lower electrode includes a first to sixth scan pad and a first and second data pad, the first light-emitting element may be connected to the first to third scan pads and the first data pad, the second light-emitting element may be connected to the first to third scan pads and the second data pad, the third light-emitting element may be connected to the fourth to sixth scan pads and the first data pad, and the fourth light-emitting element may be connected to the fourth to sixth scan pads and the second data pad.

[0019] In one embodiment of the present invention, in each light-emitting element, each of the bump electrodes includes first to fourth bump electrodes, first to third scan signals are applied to the first to third bump electrodes, and a data signal may be applied to the fourth bump electrode.

[0020] In one embodiment of the present invention, the molding layer may be formed by a vacuum laminate method.

[0021] In one embodiment of the present invention, the light-emitting element package can be adopted in a display device or a vehicle lighting device. In this case, it may include a base substrate and at least one light-emitting element package provided on the base substrate.

[0022] The light-emitting element package according to one embodiment of the present invention is manufactured by forming each light-emitting element, arranging each light-emitting element on a printed circuit board, forming a molding layer on the printed circuit board by a vacuum laminate method so as to cover each light-emitting element, forming fine concavo-convex portions on the surface of the molding layer by treating the surface exposed outside the molding layer, cutting the printed circuit board and the molding layer, and forming a light-emitting element package. Further, the molding layer covers the upper surface of the substrate and includes a material that reflects, scatters, or absorbs a part of external light. [[ID=1​​​​​​​​​​​​​​​​​ [Figure 2b] This is a cross-sectional view along the line A-A' in Figure 2a. [Figure 3a] This is a plan view sequentially showing a method for manufacturing a light-emitting element according to one embodiment of the present invention. [Figure 3b] This figure sequentially shows a method for manufacturing a light-emitting element according to one embodiment of the present invention, and is a cross-sectional view taken along the line A-A' in Figure 3a. [Figure 4a] This is a plan view sequentially showing a method for manufacturing a light-emitting element according to one embodiment of the present invention. [Figure 4b] This figure sequentially shows a method for manufacturing a light-emitting element according to one embodiment of the present invention, and is a cross-sectional view taken along the line A-A' in Figure 4a. [Figure 5a] This is a plan view sequentially showing a method for manufacturing a light-emitting element according to one embodiment of the present invention. [Figure 5b] This figure sequentially shows a method for manufacturing a light-emitting element according to one embodiment of the present invention, and is a cross-sectional view taken along the line A-A' in Figure 5a. [Figure 6a] This is a plan view sequentially showing a method for manufacturing a light-emitting element according to one embodiment of the present invention. [Figure 6b] This figure sequentially shows a method for manufacturing a light-emitting element according to one embodiment of the present invention, and is a cross-sectional view taken along the line A-A' in Figure 6a. [Figure 7a] This is a plan view sequentially showing a method for manufacturing a light-emitting element according to one embodiment of the present invention. [Figure 7b] This figure sequentially shows a method for manufacturing a light-emitting element according to one embodiment of the present invention, and is a cross-sectional view taken along the line A-A' in Figure 7a. [Figure 8a] This diagram sequentially shows the manufacturing method of a light-emitting element package. [Figure 8b] This diagram sequentially shows the manufacturing method of a light-emitting element package. [Figure 8c] This diagram sequentially shows the manufacturing method of a light-emitting element package. [Figure 8d] This diagram sequentially shows the manufacturing method of a light-emitting element package. [Figure 8e] This diagram sequentially shows the manufacturing method of a light-emitting element package. [Figure 9a] These are scanning electron microscope (SEM) images showing the molding layer with and without plasma treatment. [Figure 9b] These are scanning electron microscope (SEM) images showing the molding layer with and without plasma treatment. [Figure 10a] This is a cross-sectional view sequentially showing the process of forming fine irregularities on the surface of a molding layer using an imprint mold. [Figure 10b] This is a cross-sectional view sequentially showing the process of forming fine irregularities on the surface of a molding layer using an imprint mold. [Figure 10c] This is a cross-sectional view sequentially showing the process of forming fine irregularities on the surface of a molding layer using an imprint mold. [Figure 10d] This is a cross-sectional view sequentially showing the process of forming fine irregularities on the surface of a molding layer using an imprint mold. [Figure 10e] This is a cross-sectional view sequentially showing the process of forming fine irregularities on the surface of a molding layer using an imprint mold. [Figure 11a] This is a plan view showing a light-emitting element package according to one embodiment of the present invention, and a top view showing that four light-emitting elements are mounted in a matrix on a single printed circuit board. [Figure 11b] Figure 11a is a rear view of the light-emitting element package shown. [Figure 12] Figures 11a and 11b are circuit diagrams of the light-emitting element package. [Figure 13] This is a schematic cross-sectional view showing the manufacture of a light source module by mounting a large number of light-emitting element packages onto a base substrate for application in display devices, vehicle lighting systems, and the like. [Figure 14] This is a conceptual plan view showing how a light-emitting element package according to one embodiment of the present invention can be applied to a display device. [Figure 15] This is a plan view showing an enlarged view of the P1 portion of Figure 14. [Modes for carrying out the invention]

[0025] The present invention is subject to various modifications and may take many forms; therefore, specific embodiments are illustrated in the drawings and described in detail in the text. However, this should not be understood as limiting the present invention to any particular disclosure, but rather as including all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the present invention.

[0026] Preferred embodiments of the present invention will be described in more detail below with reference to the attached drawings.

[0027] The present invention relates to a light-emitting element, and more particularly, to a light-emitting element that emits light. The light-emitting element of the present invention can be used as a light source in a variety of devices.

[0028] Figure 1 is a cross-sectional view showing a light-emitting element according to one embodiment of the present invention.

[0029] Referring to Figure 1, a light-emitting element according to one embodiment of the present invention includes a light-emitting structure consisting of a plurality of sequentially stacked epitaxial stacks. The light-emitting structure is provided on a substrate 11.

[0030] The substrate 11 is provided in the shape of a plate having a front and a back.

[0031] The multiple epitaxial stacks included in the light-emitting structure are provided in groups of two or more, and each can emit light in different wavelength bands. That is, multiple epitaxial stacks are provided, and each has the same or different energy bands. In this embodiment, the light-emitting structure is shown to consist of three layers in which epitaxial stacks are sequentially stacked on the front surface of the substrate 11, so the multiple epitaxial stacks are stacked in the order of the third epitaxial stack 40, the second epitaxial stack 30, and the first epitaxial stack 20 from the front surface of the substrate 11.

[0032] The substrate 11 may be formed of a light-transmitting insulating material.

[0033] The material of the substrate 11 may be one of several growth substrates on which an epitaxial stack, i.e., a third epitaxial stack 40, can be grown, provided on the front surface of the substrate 11. In one embodiment of the present invention, the substrate 11 may be sapphire (Al2O3), silicon carbide (SiC), gallium nitride (GaN), indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN), aluminum nitride (AlN), gallium oxide (Ga2O3), or a silicon substrate (Si).

[0034] Each epitaxial stack emits light toward the back of the substrate 11 (downward in Figure 1). At this time, the light emitted from one epitaxial stack travels toward the back of the substrate 11 while passing through other epitaxial stacks located in the optical path.

[0035] In this embodiment, the first epitaxial stack 20 can emit first light, the second epitaxial stack 30 can emit second light, and the third epitaxial stack 40 can emit third light. Here, the first to third lights may be the same or different from each other. In one embodiment of the present invention, the first to third lights may be color light in the visible light wavelength band.

[0036] In one embodiment of the present invention, the first to third lights may be light in different wavelength bands having progressively shorter wavelengths. That is, the first to third lights may have the same or different wavelength bands, and may be light in the short wavelength band having higher energy from the first light to the third light. In this embodiment, the first light may be red light, the second light may be green light, and the third light may be blue light.

[0037] However, the first to third lights may be light in different wavelength bands having progressively longer wavelengths, or they may be light in different wavelength bands arranged irregularly regardless of wavelength length. In one embodiment, the first light may be red light, the second light may be blue light, and the third light may be green light.

[0038] In a light-emitting structure according to one embodiment of the present invention having the structure described above, each epitaxial stack is independently connected to a signal line to which a light-emitting signal is applied, thereby driving each epitaxial stack independently. As a result, a variety of colors can be realized by determining whether or not light is emitted from each epitaxial stack. Furthermore, since epitaxial stacks emitting light of different wavelengths are formed by superimposing them vertically, it is possible to form them in a small area.

[0039] More specifically, in a light-emitting laminate according to one embodiment of the present invention, a third epitaxial stack 40 is provided on the substrate 11, a second epitaxial stack 30 is provided on the third epitaxial stack 40 with a second adhesive layer 63 in between, and a first epitaxial stack 20 is provided on the second epitaxial stack 30 with a first adhesive layer 61 in between.

[0040] The first and second adhesive layers 61 and 63 may be made of a non-conductive material and may include a light-transmitting material. For example, an optically clear adhesive may be used for the first and second adhesive layers 61 and 63. However, the embodiment of the present invention is not limited thereto, and the first and second adhesive layers 61 and 63 may be optically transparent to a specific wavelength. For example, the first and second adhesive layers 61 and 63 may be color filters that exhibit a predetermined color by transmitting only a specific wavelength. The color can be selected from a variety of colors and may be, for example, red, blue, or green, or a different color.

[0041] The third epitaxial stack 40 includes an n-type semiconductor layer 41, an active layer 43, and a p-type semiconductor layer 45 arranged sequentially from bottom to top. The n-type semiconductor layer 41, the active layer 43, and the p-type semiconductor layer 45 of the third epitaxial stack 40 may include a semiconductor material that emits blue light. A third p-type contact electrode 45p is provided on the upper part of the p-type semiconductor layer 45 of the third epitaxial stack 40.

[0042] The second epitaxial stack 30 includes a p-type semiconductor layer 35, an active layer 33, and an n-type semiconductor layer 31 arranged sequentially from bottom to top. The p-type semiconductor layer 35, the active layer 33, and the n-type semiconductor layer 31 of the second epitaxial stack 30 may include a semiconductor material that emits green light. A second p-type contact electrode 35p is provided at the bottom of the p-type semiconductor layer 35 of the second epitaxial stack 30.

[0043] The first epitaxial stack 20 includes a p-type semiconductor layer 25, an active layer 23, and an n-type semiconductor layer 21 arranged sequentially from bottom to top. The p-type semiconductor layer 25, the active layer 23, and the n-type semiconductor layer 21 of the first epitaxial stack 20 may include a semiconductor material that emits red light. A first p-type contact electrode 25p may be provided at the bottom of the p-type semiconductor layer 25 of the first epitaxial stack 20.

[0044] A first n-type contact electrode may be provided on top of the n-type semiconductor layer 21 of the first epitaxial stack 20. The first n-type contact electrode 21n may consist of a single layer or multiple layers of metal. For example, a variety of materials including metals such as Al, Ti, Cr, Ni, Au, Ag, Sn, W, and Cu, or alloys thereof, can be used for the first n-type contact electrode 21n.

[0045] In this embodiment, the first to third p-type contact electrodes 25p, 35p, and 45p may be made of a transparent conductive material so as to transmit light.

[0046] In this embodiment, common wiring may be connected to the n-type semiconductor layers 21, 31, and 41 of the first to third epitaxial stacks 20, 30, and 40. Here, common wiring is wiring to which a common voltage is applied. In addition, light emission signal wiring may be connected to the p-type semiconductor layers 25, 35, and 45 of the first to third epitaxial stacks 20, 30, and 40, respectively, via p-type contact electrodes 25p, 35p, and 45p. More specifically, a common voltage S may be applied to the first n-type contact electrode 21n and the second and third n-type semiconductor layers 31 and 41 via common wiring. C When a light is applied, the emission of light signals is applied to the p-type contact electrodes 25p, 35p, and 45p of the first to third epitaxial stacks 20, 30, and 40 via the emission signal wiring, thereby controlling the emission of light from the first to third epitaxial stacks 20, 30, and 40. Here, the emission signals are the first to third emission signals S corresponding to each of the first to third epitaxial stacks 20, 30, and 40. R S G S B Includes. In one embodiment of the present invention, the first light emission signal S R This is red light, second light emission signal S G This is green light, the third light emission signal S B This could be a signal corresponding to the emission of blue light.

[0047] According to the above-described embodiments, the first to third epitaxial stacks 20, 30, 40 are driven by light emission signals applied to each epitaxial stack. That is, the first epitaxial stack 20 is driven by the first light emission signal S R and the second epitaxial stack 30 is driven by the second light emission signal S G and the third epitaxial stack 40 is driven by the third light emission signal S B . Here, the first, second, and third light emission signals S R , S G , S B are applied to the first to third epitaxial stacks 20, 30, 40 independently of each other. As a result, the first to third epitaxial stacks 20, 30, 40 are driven independently. The light emitting laminate can finally provide light of various colors and various light amounts by a combination of the first to third lights emitted downward from the first to third epitaxial stacks 20, 30, 40.

[0048] In the above-described embodiments, it has been described that a common voltage is supplied to the n-type semiconductor layers 21, 31, 41 of the first to third epitaxial stacks 20, 30, 40 and a light emission signal is applied to the p-type semiconductor layers 25, 35, 45 of the first to third epitaxial stacks 20, 30, 40. However, embodiments of the present invention are not limited thereto. In other embodiments of the present invention, a common voltage may be supplied to the p-type semiconductor layers 25, 35, 45 of the first to third epitaxial stacks 20, 30, 40 and a light emission signal may be applied to the n-type semiconductor layers 21, 31, 41 of the first to third epitaxial stacks 20, 30, 40.

[0049] In the present invention, a light-emitting laminate having the structure described above provides light in a region where parts of different light are superimposed, rather than different light being realized on separate planes, thus enabling miniaturization and integration of light-emitting elements. According to the present invention, by superimposing parts of light-emitting elements that embody different light in a single region, a laminate is provided, and as a result, full color can be realized in a significantly smaller area compared to existing inventions. This makes it possible to manufacture high-resolution devices even in a small area. Furthermore, in a light-emitting laminate having the structure described above, if epitaxial stacks that emit light in the same wavelength band are stacked instead of each epitaxial stack that emits light in different wavelength bands, it is possible to manufacture light-emitting devices with diverse control over light intensity.

[0050] In one embodiment of the present invention, a light-emitting laminate is constructed by sequentially stacking multiple epitaxial stacks on a single substrate, then forming contact portions on the multiple epitaxial stacks through a minimal number of steps, and connecting wiring portions. Furthermore, compared to existing methods for manufacturing display devices in which individual color light-emitting elements are manufactured separately and individually mounted, the present invention simplifies the manufacturing process significantly because it only requires mounting a single light-emitting laminate instead of multiple light-emitting elements.

[0051] Since the light-emitting element according to one embodiment of the present invention can be realized in various forms, specific embodiments will be described with reference to Figures 2a and 2b.

[0052] Figure 2a is a plan view specifically showing a light-emitting element according to one embodiment of the present invention, and Figure 2b is a cross-sectional view along the line A-A' in Figure 2a.

[0053] Referring to Figures 2a and 2b, a light-emitting element according to one embodiment of the present invention includes a substrate 11, a light-emitting structure provided on the substrate and including a plurality of epitaxial stacks, and bump electrodes 20bp, 30bp, 40bp, and 50bp provided on the light-emitting structure. The light-emitting structure includes a third epitaxial stack 40, a second epitaxial stack 30, and a first epitaxial stack 20 stacked on the substrate 11.

[0054] Each of the first to third epitaxial stacks 20, 30, and 40 includes a p-type semiconductor layer, an n-type semiconductor layer, and an active layer provided between the p-type and n-type semiconductor layers. In the drawings, the n-type semiconductor layer, p-type semiconductor layer, and active layer of each epitaxial stack are shown as a single-layer epitaxial stack.

[0055] A third p-type contact electrode 45p, a second adhesive layer 63, and a second p-type contact electrode 35p are sequentially provided on the third epitaxial stack 40. The second p-type contact electrode 35p is in direct contact with the second epitaxial stack 30.

[0056] A first adhesive layer 61 and a first p-type contact electrode 25p are sequentially provided on the second epitaxial stack 30. The first p-type contact electrode 25p is in direct contact with the first epitaxial stack 20.

[0057] A first n-type contact electrode 21n is provided on the first epitaxial stack 20. The first n-type semiconductor layer 21 may have a structure in which a part of its upper surface is recessed, and the first n-type contact electrode 21n may be provided in the recessed portion.

[0058] A single-layer or multi-layer insulating film is provided on the substrate 11 on which the first to third epitaxial stacks 20, 30, and 40 are stacked. In one embodiment of the present invention, a first insulating film 81 and a second insulating film 83 covering the stack of the first to third epitaxial stacks 20, 30, and 40 may be provided on the sides and parts of the top surface of the first to third epitaxial stacks 20, 30, and 40. The first and / or second insulating films 81 and 83 may be made of a variety of intrinsic and inorganic insulating materials, and their material and form are not limited. For example, the first and / or second insulating films 81 and 83 may be provided as a silicon oxide film, a silicon nitride film, Al2O3, or DBR (distributed Bragg reflector). Alternatively, the first and / or second insulating films 81 and 83 may be black-colored organic polymer films.

[0059] Each pixel is provided with contacts for connecting wiring to the first to third epitaxial stacks 20, 30, and 40. The contacts include a first contact 20C for supplying a light-emitting signal to the first epitaxial stack 20, a second contact 30C for supplying a light-emitting signal to the second epitaxial stack 30, a third contact 40C for supplying a light-emitting signal to the third epitaxial stack 40, and a fourth contact 50C for applying a common voltage to the first to third epitaxial stacks 20, 30, and 40. In one embodiment of the present invention, the first to fourth contacts 20C, 30C, 40C, and 50C can be provided in various positions when viewed from a planar perspective.

[0060] The first to fourth contact portions 20C, 30C, 40C, and 50C may each include the first to fourth pads 20pd, 30pd, 40pd, and 50pd, and the first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp, respectively.

[0061] The first to fourth pads 20pd, 30pd, 40pd, and 50pd are each separated from and insulated from one another.

[0062] Each of the first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp may be separated from each other and insulated, and may be provided in a region that overlaps with the first to third epitaxial stacks 20, 30, and 40, i.e., in the light emission region. Each of the first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp may be formed along the edges of the first to third epitaxial stacks 20, 30, and 40, thereby covering each side of the active layer of the first to third epitaxial stacks 20, 30, and 40.

[0063] The first contact portion 20C includes a first pad 20pd and a first bump electrode 20bp that are electrically connected to each other. The first pad 20pd is provided on the first p-type contact electrode 25p of the first epitaxial stack 20 and is connected to the first p-type contact electrode 25p via a first contact hole 20CH provided in the first insulating film 81. At least a portion of the first bump electrode 20bp overlaps with the first pad 20pd. In the region where the first bump electrode 20bp overlaps with the first pad 20pd, the first bump electrode 20bp is connected to the first pad 20pd via a first through-hole 20ct, with the second insulating film 83 in between.

[0064] The second contact portion 30C includes a second pad 30pd and a second bump electrode 30bp that are electrically connected to each other. The second pad 30pd is provided on the second p-type contact electrode 35p and is connected to the second p-type contact electrode 35p via a second contact hole 30CH formed in the first insulating film 81. At least a portion of the second bump electrode 30bp overlaps with the second pad 30pd. In the region where the second bump electrode 30bp overlaps with the second pad 30pd, the second bump electrode 30bp is connected to the second pad 30pd via a second through-hole 30ct, with the second insulating film 83 in between.

[0065] The third contact portion 40C includes a third pad 40pd and a third bump electrode 40bp that are electrically connected to each other. The third pad 40pd is provided on the third p-type contact electrode 45p and is connected to the third p-type contact electrode 45p via a third contact hole 40CH formed in the first insulating film 81. At least a portion of the third bump electrode 40bp overlaps with the third pad 40pd. In the region where the third bump electrode 40bp overlaps with the third pad 40pd, the third bump electrode 40bp is connected to the third pad 40pd via a third through-hole 40ct, with the second insulating film 83 in between.

[0066] The fourth contact portion 50C includes a fourth pad 50pd and a fourth bump electrode 50bp that are electrically connected to each other. The fourth pad 50pd is connected to the first to third epitaxial stacks 20, 30, and 40, respectively, via the first n-type contact electrode 21n and first to third subcontact holes 50CHa, 50CHb, and 50CHc provided on the first n-type contact electrode 21n and second and third n-type semiconductor layers of the first to third epitaxial stacks 20, 30, and 40. Here, the third n-type semiconductor layer of the third epitaxial stack 40 is exposed by removing a portion of its upper surface, and the fourth pad 50pd is connected to the third n-type semiconductor layer of the third semiconductor layer.

[0067] More specifically, the fourth pad 50pd is connected to the first epitaxial stack 20 via a first sub-contact hole 50CHa provided on the first n-type contact electrode of the first epitaxial stack 20, connected to the second epitaxial stack 30 via a second sub-contact hole 50CHb provided on the second n-type semiconductor layer of the second epitaxial stack 30, and connected to the third epitaxial stack 40 via a third sub-contact hole 50CHc provided on the third n-type semiconductor layer of the third epitaxial stack 40. The fourth bump electrode 50bp overlaps with the fourth pad 50pd in at least a portion thereof. In the region where the fourth bump electrode 50bp overlaps with the fourth pad 50pd, the fourth bump electrode 50bp is connected to the fourth pad 50pd via a fourth through-hole 50ct, with the second insulating film 83 in between.

[0068] In one embodiment of the present invention, although not shown, the substrate 11 may be further provided with wiring sections (see Figure 5) that correspond to the first to fourth contact sections 20C, 30C, 40C, and 50C and are electrically connected to each of the first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp, and / or driving elements such as thin-film transistors connected to the wiring sections. For example, the first to third epitaxial stacks 20, 30, and 40 may be connected to first to third light emission signal wiring that supplies light emission signals to each of the first to third epitaxial stacks 20, 30, and 40 via the first to third bump electrodes 20bp, 30bp, and 40bp, and to common wiring that supplies a common voltage to each of the first to third epitaxial stacks 20, 30, and 40 via the fourth bump electrode 50bp. In this embodiment, the first to third light emission signal wiring may correspond to first to third scan wiring, and the common wiring may correspond to data wiring.

[0069] Figures 3a to 7b sequentially show a method for manufacturing a light-emitting element according to one embodiment of the present invention, where Figures 3a, 4a, 5a, 6a, and 7a are plan views, and Figures 3b, 4b, 5b, 6b, and 7b are cross-sectional views along the line A-A' in Figures 3a, 4a, 5a, 6a, and 7a.

[0070] Referring to Figures 3a and 3b, a light-emitting structure is formed on the substrate 11. In the light-emitting structure, the third epitaxial stack 40, the third p-type contact electrode 45p, the second adhesive layer 63, the second p-type contact electrode 35p, the second epitaxial stack 30, the first adhesive layer 61, the first p-type contact electrode 25p, the first epitaxial stack 20, and the first n-type contact electrode 21n can be grown sequentially through various processes such as chemical vapor deposition, metal-organic chemical vapor deposition, and molecular beam deposition.

[0071] The light-emitting structure can be patterned into various shapes, taking into account the overall wiring connection structure and other factors. For example, it may be formed in a polygonal shape when viewed from a planar perspective, taking into account the positions of each contact hole, each through hole, and each pad as described above.

[0072] According to one embodiment, through the etching process, a portion of the first to third epitaxial stacks 20, 30, 40 and the first to third p-type contact electrodes 25p, 35p, 45p are etched, and the upper surfaces of the positions where the first to fourth contact holes 20CH, 30CH, 40CH, 50CH (see Figures 4a and 4b) are formed can be exposed.

[0073] Referring to Figures 4a and 4b, the first insulating film 81 may be conformally formed on vertically stacked light-emitting structures. The first insulating film 81 may include an oxide, such as silicon oxide and / or silicon nitride.

[0074] The first insulating film 81 is partially removed by patterning, resulting in the formation of the first to fourth contact holes 20CH, 30CH, 40CH, and 50CH.

[0075] The first contact hole 20CH is positioned on the first p-type contact electrode 25p, exposing a portion of the first p-type contact electrode 25p. The second contact hole 30CH is positioned on the second epitaxial stack 30, exposing a portion of the second p-type contact electrode 35p. The third contact hole 40CH is positioned on the third p-type contact electrode 45p, exposing a portion of the third p-type contact electrode 45p. The fourth contact hole 50CH includes the first to third subcontact holes 50CHa, 50CHb, and 50CHc, each of which is positioned on the first n-type contact electrode 21n, the second n-type semiconductor layer of the second epitaxial stack 30, and the third n-type semiconductor layer of the third epitaxial stack 40, exposing a portion of the first n-type contact electrode 21n, the second n-type semiconductor layer of the second epitaxial stack 30, and the third n-type semiconductor layer of the third epitaxial stack 40.

[0076] Referring to Figures 5a and 5b, the first to fourth pads 20pd, 30pd, 40pd, and 50pd are formed on the first insulating film 81 on which the first to fourth contact holes 20CH, 30CH, 40CH, and 50CH are formed. Various conductors, including metals, can be used as the conductive film material for forming the first to fourth pads 20pd, 30pd, 40pd, and 50pd. For example, the first to fourth pads 20pd, 30pd, 40pd, and 50pd may consist of at least one of Ni, Ag, Au, Pt, Ti, Al, and Cr.

[0077] The first to fourth pads 20pd, 30pd, 40pd, and 50pd are formed to overlap with the portions in which the first to fourth contact holes 20CH, 30CH, 40CH, and 50CH are formed. Here, the fourth pad 50pd may be formed to overlap simultaneously with the portions in which the first to third sub-contact holes 50CHa, 50CHb, and 50CHc are formed.

[0078] Referring to Figures 6a and 6b, a second insulating film 83 may be conformally formed on the first insulating film 81. The second insulating film 83 may contain an oxide, such as silicon oxide and / or silicon nitride.

[0079] The second insulating film 83 is partially removed by patterning, resulting in the formation of first to fourth through-holes of 20ct, 30ct, 40ct, and 50ct.

[0080] The first to fourth through-holes 20ct, 30ct, 40ct, and 50ct are positioned on the first to fourth pads 20pd, 30pd, 40pd, and 50pd, respectively, exposing a portion of the first to fourth pads 20pd, 30pd, 40pd, and 50pd.

[0081] Referring to Figures 7a and 7b, first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp are formed on the second insulating film 83, which has first to fourth through holes 20ct, 30ct, 40ct, and 50ct formed on it.

[0082] The first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp are formed to overlap with the portions where the first to fourth through holes 20ct, 30ct, 40ct, and 50ct are formed, respectively. As a result, the first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp are connected to the first to fourth pads 20pd, 30pd, 40pd, and 50pd, respectively, via the first to fourth through holes 20ct, 30ct, 40ct, and 50ct.

[0083] The first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp may have a larger area than the corresponding first to fourth pads 20pd, 30pd, 40pd, and 50pd. Furthermore, when viewed from a planar perspective, the first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp may overlap, at least in part, with the light-emitting regions from the first to third epitaxial stacks 20, 30, and 40.

[0084] The first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp may be formed by a plating method using a variety of metals. The first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp may further include a seed layer for forming a metal layer in the plating process. A variety of metals, such as those containing Cu, Ni, and Ti, can be used for the seed layer, and the seed layer can be varied depending on the metal material to be plated.

[0085] When the first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp are formed by a plating method, it is possible to form the upper surfaces of the first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp flat. The light-emitting structure has an upper step due to etching or other means to form a contact structure for connection with external wiring, but when connecting with other elements, the step can make electrical connection between other elements and the light-emitting structure difficult when forming a general metal layer. However, when formed by a plating method, it is possible to form each electrode having a flat upper surface even on a light-emitting structure made of an epitaxial layer with a large step. In addition, although the plated first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp may themselves have a flat upper surface, additional polishing may be performed on the upper surfaces of the first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp to increase the flatness.

[0086] The first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp are not particularly limited as long as they are used as wiring materials in semiconductor devices, but may be made of metals and / or metal alloys such as SnAg, Sn, CuSn, CuN, CuAg, Sb, Ni, Zn, Mo, and Co. In one embodiment of the present invention, the first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp may be made of Sn alone, or of Cu / Ni / Sn. When the first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp are made of Cu / Ni / Sn, internal diffusion of impurities into the light-emitting structure can be minimized, and in particular, by using Cu as the material for each bump electrode, penetration of Sn into the light-emitting structure can be prevented.

[0087] The first to fourth bump electrodes 20bp, 30bp, 40bp, and 50bp can be formed using a plating method, and then their strength can be increased through an additional heat treatment process, namely a reflow process.

[0088] In one embodiment of the present invention, the light-emitting element having the structure described above can be realized as a package and function as a single light-emitting element package by being mounted on another device, such as a printed circuit board. As a result, various additional wirings can be provided to create a structure that facilitates mounting on other devices.

[0089] Figures 8a to 8e sequentially illustrate the manufacturing method of a light-emitting device package. In Figures 8a to 8e, for the sake of explanation, the first to third epitaxial stacks are simplified and shown as the light-emitting structure 10, and the first to fourth pads and first to fourth bump electrodes are also simplified and shown as pad pd and bump electrode bp. In particular, although the light-emitting structure 10 is simplified in the drawings as having a flat top surface, it actually has a structure with steps and / or slopes on its top surface.

[0090] In one embodiment of the present invention, a light-emitting element package can be formed by mounting at least one light-emitting element 110 on a printed circuit board 11p on which wiring and the like are formed. The light-emitting element package may include a particularly large number of light-emitting elements 110.

[0091] Referring to Figure 8a, a printed circuit board 11p is prepared, and a number of light-emitting elements 110 are arranged on the printed circuit board 11p.

[0092] The printed circuit board 11p has wiring and electrodes formed on it for electrical connections between various elements, and at least one light-emitting element 110 may be mounted on the surface of the printed circuit board 11p. The printed circuit board 11p can be provided in various forms depending on the arrangement of its wiring, but in this embodiment, for the sake of explanation, electrodes are shown to be provided on the front, back, and between the front and back of the board 11. However, the arrangement of the wiring on the printed circuit board 11p is not limited to this. In one embodiment of the present invention, the printed circuit board 11p may or may not be flexible.

[0093] In one embodiment of the present invention, the printed circuit board 11p has a front and a back surface. Each upper electrode 11pa is provided on the front surface of the printed circuit board 11p, each lower electrode 11pc is provided on the back surface, and each via electrode 11pb is provided that penetrates the front and back surfaces of the printed circuit board 11p and connects each upper electrode 11pa and each lower electrode 11pc. The front surface of the printed circuit board 11p is the surface on which each light-emitting element 110 is mounted. In one embodiment of the present invention, each upper electrode 11pa of the printed circuit board 11p is formed at a position corresponding to each bump electrode bp of each light-emitting element 110 that will be attached later.

[0094] Each wiring and / or electrode on the printed circuit board 11p may be surface-treated with ENIG (Electroless Nikel Immersion Gold). For example, in one embodiment of the present invention, each upper electrode 11pa in particular may be surface-treated with ENIG. When each wiring and / or electrode on the printed circuit board 11p is treated with ENIG, it can be easily connected to each bump electrode bp of each light-emitting element 110 while partially melting at high temperatures.

[0095] Each light-emitting element 110 is attached to a carrier substrate 11c and positioned on top of the printed circuit board 11p. The carrier substrate 11c is for transporting each light-emitting element 110, and has an adhesive layer 13 formed on one surface, which causes each light-emitting element 110 to adhere to the carrier substrate 11c. The adhesive layer 13 may be a silicon-based polymer that has strong heat resistance while allowing each light-emitting element 110 to be attached and detached, and may be manufactured in the form of a tape or sheet and provided on the underside of the carrier substrate 11c. The adhesive layer 13 can be prepared to have sufficient adhesive strength to allow each light-emitting element 110 to adhere stably to the carrier substrate 11c, and sufficient adhesive strength to allow each light-emitting element 110 to be easily separated when attached to the printed circuit board 11p. That is, the adhesive strength of the adhesive layer 13 to the light-emitting element 110 may be smaller than the adhesive strength between each light-emitting element 110 and the printed circuit board 11p.

[0096] Each light-emitting element 110 can be attached to the lower part of the carrier substrate 11c in an inverted configuration, with the substrate 11 positioned at the top and the light-emitting structure 10 at the bottom. Here, the light-emitting element 110 attached to the carrier substrate 11c has an inverted configuration in which the back surface of the substrate 11 is attached to the adhesive layer 13 on the carrier substrate 11c, with the substrate 11 on the upper side and the light-emitting structure 10 on the lower side. Each light-emitting element 110 is arranged separately on the printed circuit board 11p while attached to the carrier substrate 11c.

[0097] Referring to Figure 8b, each light-emitting element 110 is attached to the printed circuit board 11p, and the carrier substrate 11c and adhesive layer 13 are removed. Each light-emitting element 110 attached to the carrier substrate 11c can be pressed from top to bottom so that each bump electrode bp contacts the corresponding upper electrode 11pa of the printed circuit board 11p. The pressing step may be performed at a high temperature, so that a portion of each upper electrode 11pa on the printed circuit board 11p melts and connects to each bump electrode bp of each light-emitting element 110. The carrier substrate 11c is later removed, but the adhesive layer 13 on the carrier substrate 11c has a weaker adhesive force than the adhesive force between each bump electrode bp of each light-emitting element 110 and each upper electrode 11pa of the printed circuit board 11p, so that the carrier substrate 11c can be easily separated from each light-emitting element 110.

[0098] As each bump electrode bp is attached to each upper electrode 11pa of the printed circuit board 11p, the overall structure is arranged in the following order from bottom to top: printed circuit board 11p, each bump electrode bp, each pad pd, light-emitting structure 10, and substrate 11. Light from the light-emitting structure 10 travels from the light-emitting structure 10 toward the back of the substrate 11 (upward in the drawing), and as a result, the direction toward the front of the printed circuit board 11p becomes the direction from which the light is emitted.

[0099] Referring to Figure 8c, a molding layer 90 is formed on the printed circuit board 11p on which each light-emitting element 110 is mounted. The molding layer 90 has the property of transmitting at least a portion of light and reflecting, scattering, and / or absorbing a portion of the external light. The molding layer 90 covers at least a portion of the light-emitting elements 110 and prevents external light from being reflected in a specific direction, particularly in a direction visible to the user, by reflecting, scattering, and / or absorbing a portion of the external light in various directions. In addition, the molding layer 90 covers at least a portion of the light-emitting elements 110 and prevents damage to the light-emitting elements 110 from external moisture and / or physical shock, thereby increasing the reliability of the light-emitting elements 110.

[0100] The molding layer 90 is provided to reflect, scatter, and / or absorb a portion of the external light in various directions, and in particular, the molding layer 90 may have a black color. However, it may also have a color other than black, as long as it can reflect, scatter, and / or absorb a portion of the external light in various directions to the greatest extent possible to prevent reflection of external light toward the user.

[0101] To prevent reflection of external light in a specific direction, the molding layer 90 is formed to surround at least a portion of the light-emitting element 110, and in particular to cover the back surface of the substrate 11 within the light-emitting element 110. In one embodiment of the present invention, the molding layer 90 is formed to cover the back surface of the substrate 11, thereby preventing external light from being reflected by the back surface of the substrate 11 and visible to the user. To prevent such reflection of external light in a specific direction, the molding layer 90 can reflect, scatter, or absorb about 50% or more of the external light in various directions. In one embodiment of the present invention, the molding layer 90 can reflect, scatter, or absorb about 80% or more of the external light.

[0102] The molding layer 90 may be formed with a thickness that allows for maximum light emission from the light-emitting structure 10 toward the back side (i.e., upward direction) of the substrate 11. For example, when the molding layer 90 is provided on the back side of the light-emitting structure 10, it may be formed with a thickness that transmits 50% or more of the light from the light-emitting structure, or it may be provided with a thickness such that the height from the back side of the light-emitting structure 10 is 100 micrometers or less. Alternatively, the height of the molding layer 90 from the back side of the light-emitting structure 10 may be less than the thickness of the light-emitting element.

[0103] The molding layer 90 is formed not only on the back side of the substrate 11, but can also cover the sides of the light-emitting element 110, i.e., the sides of the substrate 11 and the sides of the light-emitting structure 10. By covering the sides of the light-emitting element 110 with the molding layer 90, at least a portion of the light emitted through the sides of the light-emitting element 110 can be absorbed by the molding layer 90. This prevents the light emitted from the light-emitting structure 10 from mixing with light emitted from adjacent light-emitting structures 10.

[0104] In one embodiment of the present invention, the molding layer 90 may be made of an organic polymer that absorbs light. In one embodiment of the present invention, the molding layer 90 may further contain an organic / inorganic filler in addition to the organic polymer, or it may not contain an organic / inorganic filler. For example, if the molding layer 90 contains a filler, the filler may be an inorganic filler. A variety of inorganic fillers can be used, for example, silica, alumina, etc.

[0105] Furthermore, the molding layer 90 fills at least a portion of the space between the light-emitting structure 10 and the printed circuit board 11p. That is, the molding layer 90 can fill the empty space between the light-emitting structure 10, where each bump electrode bp is provided, and the printed circuit board 11p. By filling the space between the light-emitting structure 10 and the printed circuit board 11p with the molding layer 90, the heat generated from the light-emitting structure 10 can be effectively dispersed. As a result, the heat dissipation characteristics of each light-emitting element 110 are improved.

[0106] In one embodiment of the present invention, the molding layer 90 can be manufactured by various methods such as lamination, coating, chemical vapor deposition, printing, and transfer molding. During the manufacture of the molding layer 90, various thinning processes may be used, including additional steps to planarize the surface of the molding layer 90. For example, to planarize the surface of the molding layer 90, squeegeeing may be performed after coating and before the material of the molding layer 90 hardens, or pressure planarization may be performed using a flat plate. Alternatively, after the material of the molding layer 90 hardens, polishing or lapping may be performed on the surface.

[0107] In one embodiment of the present invention, the molding layer 90 can be formed by a transfer molding method, thereby obtaining a flat upper surface for the molding layer 90. The transfer molding method may be performed through injection molding, in which a certain unit of package on which light-emitting elements are mounted is placed on a molding die, and then resin that has been liquefied in a solid state is injected into the inside of the die under pressure to form the product.

[0108] Among the methods for planarizing the surface of the molding layer 90, the lamination method may be a vacuum lamination method performed in a vacuum. In this case, the molding layer 90 may be formed from an organic polymer sheet in film form, or it may be formed by placing the organic polymer sheet on a printed circuit board 11p on which each light-emitting element 110 is mounted, and then heating and pressurizing it in a vacuum atmosphere. The organic polymer sheet can become partially fluid at high temperature and pressure, and such fluidity allows it to fill the areas between each light-emitting element 110 and the spaces between each light-emitting element 110 and the printed circuit board 11p. The organic polymer sheet is then cured.

[0109] In one embodiment of the present invention, the molding layer 90 is formed by a vacuum lamination method, thereby obtaining a flat upper surface for the molding layer 90. Conventionally, the molding layer 90 was formed using a process in which an organic polymer material was applied and then cured. In this case, a difference in upper surface height occurred between the area on which each light-emitting element 110 was mounted and the area on which each light-emitting element 110 was not mounted. This difference in upper surface height causes non-uniformity of the light emitted from each light-emitting element 110. However, according to one embodiment of the present invention, by forming the upper surface of the molding layer 90 flat, the uniformity of light is increased regardless of the position of each light-emitting element 110.

[0110] In addition, the molding layer 90 stably holds each light-emitting element 110, thus increasing the rigidity of the light-emitting element package. In particular, the molding layer 90 can fill the space between the printed circuit board 11p and each light-emitting element 110, which can increase the adhesive strength between the printed circuit board 11p and each light-emitting element 110. As a result, the overall rigidity of the light-emitting element package is further increased.

[0111] Referring to Figure 8d, the surface of the molding layer 90 is textured, and fine irregularities 91 are formed on the surface exposed to the outside of the molding layer 90. The fine irregularities 91 are for diffuse reflection, and by diffusely reflecting external light from the outside through the fine irregularities 91, the amount of external light reflected into the user's field of view is further minimized. When the light-emitting element package is used in various applications such as lighting and display devices, the substrate 11 of the light-emitting element is positioned opposite the user's line of sight, so it is necessary to minimize the amount of light reflected by the substrate 11. Thus, by forming additional fine irregularities 91 in addition to the molding layer 90 which has light scattering, light reflecting, and light absorbing properties, glare to the user due to the reflection of external light is further reduced.

[0112] In one embodiment of the present invention, the molding layer may further contain fillers such as silica or alumina, so that after texturing, each of these filler particles may be exposed on the surface of the molding layer. In this case, the random exposure of each filler particle on the surface can further improve the degree of scattering of external light.

[0113] There are various methods for forming the fine irregularities 91. In one embodiment of the present invention, the surface of the molding layer 90 can be etched using plasma.

[0114] Figures 9a and 9b are SEM images showing the surface of the molding layer with and without plasma treatment, respectively.

[0115] As can be seen in Figure 9a, after plasma treatment, numerous fillers are randomly exposed to the outside on the surface of the molding layer. These numerous fillers are exposed to the external surface at varying sizes and frequencies, which can significantly increase the scattering effect of external light by the fillers.

[0116] In contrast, Figure 9b shows that the number of fillers exposed on the surface is significantly smaller when plasma treatment is not performed compared to when plasma treatment is performed. This confirms that fine irregularities can be easily formed on the surface of the molding layer using plasma treatment.

[0117] Analysis of the components before and after plasma treatment revealed no change in the composition of the molding layer, indicating that fine irregularities can be formed without modification of the molding layer.

[0118] In one embodiment of the present invention, in addition to plasma treatment, the surface can be roughened and fine irregularities formed by micro-sandblasting. When using micro-sandblasting, fine particles of several micrometers to tens of micrometers in size are sprayed onto the surface of the molding layer at high pressure, and after cleaning the surface of the molding layer with ultrasonic cleaning or the like, it is dried to form fine irregularities on the surface of the molding layer. Alternatively, methods such as dry polishing or wet etching of the surface of the molding layer 90 may be used alone or in combination with the above-described methods.

[0119] According to one embodiment of the present invention, by using an imprint mold on which a fine uneven pattern is formed, a fine uneven portion can be formed on the surface of the molding layer by transferring the fine uneven pattern to the surface of the molding layer.

[0120] Figures 10a to 10e are cross-sectional views sequentially showing the process of forming fine irregularities on the surface of a molding layer using an imprint mold.

[0121] Referring to Figure 10a, first, a master mold MM is manufactured. The master mold MM has the same pattern (indicated by 91) as the fine irregularities that will be transferred to the surface of the molding layer, and is used to subsequently form the reverse pattern on the imprint mold IMP.

[0122] Referring to Figure 10b, the imprint mold IMP material is applied to the master mold MM, the imprint mold IMP is cured, and then the imprint mold IMP is separated from the master mold MM. As a result, the reverse pattern of the fine irregularities on the master mold MM (indicated as 91R) is formed on the underside of the imprint mold IMP.

[0123] Referring to Figure 10c, the imprint mold IMP with the inverted pattern 91R is placed on top of the molding layer 90, and then pressurized from top to bottom.

[0124] Referring to Figure 10d, the pressurization of the imprint mold IMP transfers the inverse pattern 91R of the imprint mold IMP to the upper surface of the molding layer 90, and after the transfer, the imprint mold IMP is separated from the molding layer 90.

[0125] Referring to Figure 10e, fine irregularities 91 are formed on the upper surface of the molding layer 90 from which the imprint mold IMP has been removed.

[0126] According to this embodiment, the shape of the micro-relief portion of the final molding layer is determined by the shape of the micro-relief pattern on the master mold. This allows the shape, density, etc., of the micro-relief pattern on the master mold to be varied as needed. As a result, the shape and density of the micro-relief portion of the molding layer can be controlled, and ultimately, the degree of scattering of external light by the micro-relief portion on the upper surface of the molding layer can be easily adjusted.

[0127] Referring again to Figure 8e, after the molding layer 90 having fine irregularities is formed, the printed circuit board 11p and each light-emitting element 110 are cut to be included in the light-emitting element package at an appropriate size, thereby forming the light-emitting element package. At this time, the light-emitting elements 110 may be cut so that they are individually separated and included, or they may be cut to a large area so that a large number of light-emitting elements 110 are included. The number and area of ​​each light-emitting element 110 at the time of cutting may be set in different shapes depending on the device on which each light-emitting element 110 will be mounted later.

[0128] In a light-emitting element package, the number of individual light-emitting elements mounted on a printed circuit board forming a single light-emitting element package can be varied. Figure 11a is a plan view showing a light-emitting element package according to one embodiment of the present invention, and is a top view showing that four light-emitting elements are mounted in a matrix on a single printed circuit board. Figure 11b is a rear view of the light-emitting element package shown in Figure 11a. Figure 12 is a circuit diagram of the light-emitting element package shown in Figures 11a and 11b.

[0129] Referring to Figures 11a, 11b, and 12, the light-emitting element package 110D includes a printed circuit board 11p and four light-emitting elements 110 mounted on the printed circuit board 11p in a 2x2 configuration. However, the number and arrangement of the light-emitting element packages 110D are not limited to this and can be arranged in various matrix configurations, such as 1x1, 3x3, 4x4, etc. Each light-emitting element 110 has a structure in which first to third epitaxial stacks are stacked vertically, as described above. Thus, each of the first to third epitaxial stacks corresponds to a light-emitting diode that generates light. For example, the first to third epitaxial stacks may correspond to a first light-emitting diode that emits red light, a second light-emitting diode that emits green light, and a third diode that emits blue light, respectively.

[0130] First, referring to Figure 12, the first to sixth scan lines SC1, SC2, SC3, SC4, SC5, SC6 and the first and second data lines DT1, DT2 are connected to the four light-emitting elements in order to drive them. If the four light-emitting elements are designated as the first to fourth light-emitting elements 110p, 110q, 110r, and 110s, then the first light-emitting element 110p is connected to the first to third scan lines SC1, SC2, SC3 and the first data line DT1, and the second light-emitting element 110q is connected to the first to third scan lines SC1, SC2, SC3 and the second data line DT2. Then, the third light-emitting element 110r is connected to the fourth to sixth scan lines SC4, SC5, SC6 and the first data line DT1, and the fourth light-emitting element 110s is connected to the fourth to sixth scan lines SC4, SC5, SC6 and the second data line DT2.

[0131] The three light-emitting diodes (LEDs) contained in each of the first to fourth light-emitting elements 110p, 110q, 110r, and 110s selectively emit light in response to data signals input via the data wiring when a scan signal is supplied via the scan wiring. Each diode is connected between the scan wiring and the data wiring, and when a voltage greater than or equal to a threshold voltage is applied between the p-type semiconductor layer and the n-type semiconductor layer, it emits light with a brightness corresponding to the magnitude of the applied voltage. In other words, the emission of light from each LED can be controlled by adjusting the voltage of the scan signal applied to the scan wiring and / or the data signal applied to the data wiring. As an example, during each frame period, each LED emits light with a brightness corresponding to the input data signal. Each LED that receives a data signal corresponding to the black brightness displays black by not emitting light during the corresponding frame period.

[0132] In one embodiment of the present invention, by providing six scan lines and two data lines in this manner, the first to fourth light-emitting elements 110p, 110q, 110r, and 110s can be driven individually.

[0133] For this purpose, each light-emitting element is mounted at a corresponding position on the printed circuit board 11p. Referring again to Figures 11a and 11b, each upper electrode 11pa is provided on the front surface of the printed circuit board 11p at a position corresponding to each light-emitting element 110. That is, one light-emitting element 110 has four bump electrodes bp, and the printed circuit board 11p is provided with four upper electrodes 11pa for each light-emitting element 110. The four bump electrodes bp of each light-emitting element 110 are connected to the four upper electrodes 11pa in a one-to-one superimposed arrangement.

[0134] In one embodiment of the present invention, of the first to fourth bump electrodes of the first light-emitting element 110, the first to third bump electrodes are connected to the first to third scan lines, respectively, and the fourth bump electrode is connected to the first data line. Of the first to fourth bump electrodes of the second light-emitting element 110, the first to third bump electrodes are connected to the first to third scan lines, respectively, and the fourth bump electrode is connected to the second data line. Of the first to fourth bump electrodes of the third light-emitting element 110, the first to third bump electrodes are connected to the fourth to sixth scan lines, respectively, and the fourth bump electrode is connected to the first data line. Of the first to fourth bump electrodes of the fourth light-emitting element 110, the first to third bump electrodes are connected to the fourth to sixth scan lines, respectively, and the fourth bump electrode is connected to the second data line.

[0135] A total of eight lower electrodes are arranged on the back of the printed circuit board 11p. The eight lower electrodes correspond to the first to sixth scan pads that supply scan signals to the first to sixth scan wirings, and the first and second data pads that supply data signals to the first and second data wirings. For example, if the eight lower electrodes formed on the back of the printed circuit board 11p are designated as the first to eighth lower electrodes 11pc_1, 11pc_2, ..., 11pc_8, then the first to sixth lower electrodes 11pc_1, 11pc_2, ..., 11pc_6 correspond to the first to sixth scan pads, and the seventh and eighth lower electrodes 11pc_7, 11pc_8 correspond to the first and second data pads. However, the arrangement and order of the first to sixth scan pads and the first and second data pads are not limited and can be arranged on the back of the printed circuit board 11p in various forms and areas, and may be set in a different order.

[0136] In one embodiment of the present invention, the distance between two adjacent lower electrodes may be greater than the distance between two adjacent upper electrodes. When forming a light-emitting element package, each lower electrode of the printed circuit board can function as a connecting electrode for electrical connection with other electronic elements when the light-emitting element package is mounted on other electronic elements. Therefore, by forming a relatively wide gap between two adjacent lower electrodes, the light-emitting element package can be mounted on other electronic elements more easily.

[0137] As described above, the light-emitting element package according to one embodiment of the present invention uses a printed circuit board with a simple structure, and each individually driveable light-emitting element can be easily mounted on the printed circuit board. Furthermore, when driving four light-emitting elements, only eight input terminals (i.e., eight lower electrodes) may be provided, so it is possible to drive a large number of light-emitting elements with a simple structure.

[0138] According to one embodiment of the present invention, the light-emitting element package can be applied to other devices in various forms, such as using a single element as a light source, or mounting multiple light-emitting element packages onto a base substrate to form a module, and then using that module as a light source. Examples of devices using the light-emitting element package include display devices, living room lighting devices, vehicle lighting (vehicle headlights, lamps, taillights, etc.), and various decorative lighting devices.

[0139] Figure 13 is a schematic cross-sectional view showing the manufacture of a light source module by mounting a large number of light-emitting element packages 110D on a base substrate 110b for application in display devices, vehicle lighting devices, and the like.

[0140] Referring to Figure 13, a base substrate 110b with each wiring formed on it can be prepared, and a large number of light-emitting element packages 110D can be mounted on the base substrate 110b. The base substrate 110b may or may not be flexible.

[0141] Each wiring on the base substrate 110b is provided to correspond to each bottom electrode of each light-emitting element package 110D. Each wiring on the base substrate 110b may be connected to each bottom electrode of the light-emitting element package via each connecting electrode 11s. In one embodiment of the present invention, each connecting electrode 11s may be provided in the form of solder.

[0142] As shown in Figure 13, when each light-emitting element package is mounted on a base substrate, if a defect occurs in any one of the light-emitting element packages, it can be easily repaired by replacing only that package with a good one.

[0143] Figure 14 is a conceptual plan view showing how a light-emitting element package according to one embodiment of the present invention can be applied to a display device, and Figure 15 is a plan view showing an enlarged view of portion P1 of Figure 14.

[0144] Referring to Figures 14 and 15, the light-emitting element according to one embodiment of the present invention can be used as a pixel in a display device capable of expressing a variety of colors. A large number of light-emitting elements may be mounted on a base substrate in the form of each of the light-emitting element packages 110D described above.

[0145] A display device 100 according to one embodiment of the present invention displays arbitrary visual information, such as text, video, photograph, two-dimensional or three-dimensional images, etc.

[0146] The display device 100 can be provided in a variety of shapes, including a closed polygon with straight sides such as a rectangle, a circle or ellipse with curved sides, and a semicircle or semiellipse with both straight and curved sides. In one embodiment of the present invention, the display device is shown to be provided in a rectangular shape.

[0147] The display device 100 has a plurality of pixels for displaying an image. Each pixel is the smallest unit for displaying an image and can be embodied as a single light-emitting element. Thus, in this embodiment, each pixel is represented by 110. Each pixel 110 includes a light-emitting element with the structure described above and can emit white light and / or color light.

[0148] In one embodiment of the present invention, each pixel is a first pixel 110 that emits red light R , the second pixel 110 emits green light G , and a third pixel 110 that emits blue light B Includes the first to third pixels 110 R , 110 G , 110 B These can correspond to the first to third epitaxial stacks of the light-emitting element described above.

[0149] Pixels 110 (1st to 3rd pixels) R , 110 G , 110 BThe light emitted is not limited to this; at least two pixels may emit light of the same color, or they may each emit light of a different color, such as yellow, magenta, or cyan, which are different colors from those mentioned above.

[0150] Each pixel 110 is arranged in a matrix. Here, the arrangement of each pixel 110 in a matrix does not mean that each pixel 110 is arranged precisely in a single line along the rows and columns, but rather that while the overall arrangement follows the rows and columns, the detailed positions may change, such as in a zigzag arrangement.

[0151] According to this embodiment, lighting devices of various sizes can be easily manufactured simply by mounting a large number of light-emitting element packages onto a base substrate. For example, a large-area display device can be easily manufactured using a large number of light-emitting element packages. Furthermore, if the base substrate or printed circuit board is flexible, the display device may also be flexible, making it easy to manufacture display devices of various forms, such as rollable display devices, foldable display devices, and curved display devices.

[0152] Although the above has been described with reference to preferred embodiments of the present invention, a person skilled in the art or a person with ordinary knowledge in the art will understand that the present invention can be modified and altered in various ways without departing from the spirit and technical domain of the invention as described in the claims below.

[0153] Therefore, the technical scope of the present invention should not be limited to what is described in the detailed description of the specification, but should be defined by the claims.

Claims

1. A printed circuit board having a front and a back, A first epitaxial stack, a second epitaxial stack, and a third epitaxial stack are provided on the front surface and emit light, A molding layer provided on the printed circuit board, surrounding the first epitaxial stack, the second epitaxial stack, and the third epitaxial stack, The invention includes a plurality of bump electrodes provided between the first epitaxial stack, the second epitaxial stack, and the third epitaxial stack and the printed circuit board, The first epitaxial stack emits the first light, The second epitaxial stack emits a second light in a different wavelength band than the first light, The third epitaxial stack emits a third light having a different wavelength band from the first and second light, Each of the first epitaxial stack, the second epitaxial stack, and the third epitaxial stack is provided with an inclined upper surface. Type 1 semiconductor layer, Type 2 semiconductor layer, The active layer provided between the first type semiconductor layer and the second type semiconductor layer, The first type semiconductor layer of the first epitaxial stack has a portion of its surface that is recessed, and a contact electrode is provided in the recessed portion. A light-emitting module in which the molding layer contains a filler, and the thickness of the molding layer on each epitaxial stack is less than the thickness of each epitaxial stack.

2. The light-emitting module according to claim 1, wherein the molding layer includes fine irregularities provided on the upper surface of the molding layer.

3. The light-emitting module according to claim 2, wherein the molding layer has a black color.

4. The light-emitting module according to claim 1, wherein the molding layer is provided between the front surface and the first epitaxial stack, the second epitaxial stack, and the third epitaxial stack.

5. The light-emitting module according to claim 4, wherein the molding layer is provided between the plurality of bump electrodes.

6. The light-emitting module according to claim 1, wherein the first epitaxial stack, the second epitaxial stack, and the third epitaxial stack are driven independently.

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