Double-sided LED chip

Abstract

The present invention provides a double-sided light-emitting LED chip, which is a double-sided light-emitting LED chip that emits light toward the upper side and the lower side of a P-N junction respectively, and is an LED chip that utilizes the electroluminescent effect of a P-N junction including a P layer and an N layer arranged below the P layer. The double-sided light-emitting LED chip is characterized in that it emits light toward the upper side of the P layer and the lower side of the N layer respectively. According to the present invention, it can be used as a single chip for fields requiring double-sided light emission, and can achieve miniaturization of applicable equipment, improve power efficiency, and have the effect of reducing manufacturing costs. In addition, the double-sided light-emitting LED chip manufactured according to the present invention can be manufactured by batch processing, so no separate packaging process is required. In addition, the double-sided light-emitting LED chip according to the present invention has the effect of improving light efficiency by reducing the total internal reflection of light generated by the LED.

Description

Technical Field

[0001] The present invention relates to a double-sided light-emitting LED chip, and more particularly to a double-sided light-emitting LED chip that emits light toward an upper side and a lower side respectively as a single LED chip. Background Art

[0002] The existing LED chip emits light in only one direction based on the PN bonding surface. Therefore, in order to emit light from both sides by using the existing LED chip, the LED chips must be mounted on each surface, which causes problems of increased thickness, severe power consumption, and increased manufacturing costs.

[0003] (Prior art literature)

[0004] (Patent Document)

[0005] Prior art document 1: Korean Patent Publication No. 10-2012-0040972 (publication date: April 30, 2012)

[0006] Prior art document 2: Korean patent number 10-1342418 (grant date: December 11, 2013) Summary of the invention

[0007] Technical issues

[0008] The technical problem of the present invention is to provide a structure of a double-sided light-emitting LED chip.

[0009] Another technical problem of the present invention is to provide a method for manufacturing the double-sided light-emitting LED chip.

[0010] Solutions to the problem

[0011] In order to solve the above technical problems, the present invention provides a double-sided light-emitting LED chip, which is an LED chip that utilizes the electroluminescent effect of a PN junction including a P layer and an N layer arranged below the P layer. The double-sided light-emitting LED chip is characterized in that it emits light toward the upper direction of the P layer and the lower direction of the N layer respectively.

[0012] Effects of the Invention

[0013] According to the present invention, a single chip can be used in fields requiring double-sided light emission, and can realize miniaturization of applicable equipment, improve power efficiency, and have the effect of reducing manufacturing costs.

[0014] Furthermore, the double-sided light-emitting LED chip manufactured according to the present invention can be manufactured by a batch process, and thus does not require a separate packaging process.

[0015] Also, the double-sided light-emitting LED chip according to the present invention has the effect of improving light efficiency by reducing the total internal reflection of light generated by the LED. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. 1 is a perspective view showing a double-sided light-emitting LED chip according to a first embodiment of the present invention.

[0017] Figure 2 FIG. 1 is a cross-sectional view showing a double-sided light-emitting LED chip according to a first embodiment of the present invention.

[0018] Figure 3 It is a perspective view showing the shape of a double-sided light-emitting LED chip according to the first embodiment of the present invention being separated and vertically cut.

[0019] Figure 4 FIG. 1 is a cross-sectional view showing a PN junction according to a first embodiment of the present invention.

[0020] Figure 5 FIG. 1 is a cross-sectional view showing a P-direction light emitting portion according to a first embodiment of the present invention.

[0021] Figure 6 FIG. 1 is a cross-sectional view showing an N-directional light emitting portion according to a first embodiment of the present invention.

[0022] Figure 7 FIG. 1 is a plan view showing an N-directional ohmic contact electrode according to a first embodiment of the present invention.

[0023] Figure 8 It is a cross-sectional view showing the connection relationship between the PN junction, the P-direction light emitting portion and the N-direction light emitting portion according to the first embodiment of the present invention.

[0024] Fig. 9 FIG. 1 is a flow chart showing a method for manufacturing a double-sided light-emitting LED chip according to a first embodiment of the present invention.

[0025] Fig.10 FIG. 1 is a cross-sectional view showing a first step of forming a PN junction according to a first embodiment of the present invention.

[0026] Fig.11 FIG. 1 is a flow chart showing the second step of forming a P-direction light emitting portion according to the first embodiment of the present invention.

[0027] Fig.12 FIG. 1 is a cross-sectional view showing a P-direction mesa etching step according to the first embodiment of the present invention.

[0028] Fig.13 is a cross-sectional view showing a separation etching step according to the first embodiment of the present invention.

[0029] Fig.141 is a cross-sectional view showing a P-direction insulation processing step according to the first embodiment of the present invention.

[0030] Fig.15 1 is a cross-sectional view showing a step of forming a P-directional ohmic contact electrode according to the first embodiment of the present invention.

[0031] Fig.16 FIG. 1 is a flow chart showing the P-direction selective gold plating steps according to the first embodiment of the present invention.

[0032] Fig.17 FIG. 1 is a cross-sectional view showing a step of forming a P-direction seed metal according to the first embodiment of the present invention.

[0033] Fig.18 1 is a cross-sectional view showing a step of forming a P-type photoresist according to the first embodiment of the present invention.

[0034] Fig.19 1 is a cross-sectional view showing a P-directional gold plating step according to the first embodiment of the present invention.

[0035] Fig. 20 1 is a cross-sectional view showing a P-type photoresist removal step according to the first embodiment of the present invention.

[0036] Fig.21 1 is a cross-sectional view showing a step of forming a P-connecting electrode according to the first embodiment of the present invention.

[0037] Fig. 22 FIG. 1 is a cross-sectional view showing a step of forming a P-connecting electrode having a branch structure according to another embodiment of the present invention.

[0038] Fig.23 FIG. 1 is a plan view showing a P-connection electrode having a branch structure according to another embodiment of the present invention.

[0039] Fig.24 FIG. 1 is a cross-sectional view showing a step of forming a P-oriented encapsulation material layer according to the first embodiment of the present invention.

[0040] Fig.25 is a cross-sectional view showing a third step of applying an adhesive and attaching a supporting substrate according to the first embodiment of the present invention.

[0041] Fig.26 is a cross-sectional view showing a fourth step of separating the substrate according to the first embodiment of the present invention.

[0042] Fig. 27 1 is a cross-sectional view showing a fifth step of flipping the chip array from top to bottom according to the first embodiment of the present invention.

[0043] Fig.28FIG. 1 is a flow chart showing a sixth step of forming an N-directional light emitting portion according to the first embodiment of the present invention.

[0044] Fig.29 FIG. 4 is a cross-sectional view showing an N-directional mesa etching step according to the first embodiment of the present invention.

[0045] Fig.30 1 is a cross-sectional view showing an N-directional insulation process step according to the first embodiment of the present invention.

[0046] Fig.31 1 is a cross-sectional view showing a step of forming an N-directional ohmic contact electrode according to the first embodiment of the present invention.

[0047] Fig.32 FIG. 1 is a flow chart showing the steps of N-directional selective gold plating according to the first embodiment of the present invention.

[0048] Fig.33 FIG. 1 is a cross-sectional view showing a step of forming an N-directional seed metal according to the first embodiment of the present invention.

[0049] Fig.34 1 is a cross-sectional view showing a step of forming an N-directional photoresist according to the first embodiment of the present invention.

[0050] Fig.35 1 is a cross-sectional view showing an N-directional gold plating step according to the first embodiment of the present invention.

[0051] Fig.36 1 is a cross-sectional view showing an N-directional photoresist removal step according to the first embodiment of the present invention.

[0052] Fig.37 2 is a cross-sectional view showing a step of forming an N-connecting electrode according to the first embodiment of the present invention.

[0053] Fig.38 1 is a cross-sectional view showing a step of forming an N-directional encapsulation material layer according to the first embodiment of the present invention.

[0054] Fig.39 FIG. 1 is a cross-sectional view showing a double-sided light-emitting LED chip after removing the adhesive and the supporting substrate according to the first embodiment of the present invention.

[0055] Fig.40 FIG. 1 is a cross-sectional view showing a double-sided light-emitting LED chip according to a second embodiment of the present invention.

[0056] Fig.41 1 is a flow chart showing step 2-1 of forming a P-direction light emitting portion according to the second embodiment of the present invention.

[0057] Fig.42FIG. 4 is a cross-sectional view showing a second P-direction insulation processing step according to the second embodiment of the present invention.

[0058] Fig.43 1 is a flow chart showing step 6-1 of forming an N-directional light emitting portion according to the second embodiment of the present invention.

[0059] Fig.44 1 is a cross-sectional view showing a step of forming a second N-directional ohmic contact electrode according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0060] The best way to implement the present invention is a double-sided light-emitting LED chip, which is an LED chip that utilizes the electroluminescent effect of a PN junction 10 including a P layer P and an N layer N arranged below the above-mentioned P layer P. The above-mentioned double-sided light-emitting LED chip is characterized in that it emits light toward the upper direction of the above-mentioned P layer P and the lower direction of the above-mentioned N layer N respectively.

[0061] The terms used in this specification are briefly described, and then the embodiments of the present invention are specifically described. Although the terms used in this specification are selected from general terms currently used as widely as possible in consideration of the functions in the present invention, the terms used herein may vary according to the intentions of ordinary technicians in the field or precedents, the emergence of new technologies, etc. In addition, in certain cases, some terms mentioned in the description of the present invention have been arbitrarily selected by the applicant, and their detailed meanings are described in the relevant parts of the specification here. Therefore, what is needed is to define the terms used in this specification based on the meaning of each term therein and the entire content in the present invention, rather than by simple term names.

[0062] Before describing the present invention in detail, in this specification, "upper side" refers to the upper direction in the drawings, and "lower side" refers to the lower direction in the drawings.

[0063] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0064] Figure 1 FIG. 1 is a perspective view showing a double-sided light-emitting LED chip according to a first embodiment of the present invention.

[0065] The double-sided LED chip according to the present invention has light-emitting surfaces in the upper direction and the lower direction, respectively, and the shape of the light-emitting surface can be different according to the design. In this embodiment, the description is based on having a square light-emitting surface. According to the present invention, the double-sided LED chip performs double-sided light emission from one surface along the vertical direction through upper side light emission (Emit 1) and lower side light emission (Emit 2).

[0066] Figure 2FIG. 1 is a cross-sectional view of a double-sided light emitting LED chip according to a first embodiment of the present invention. The double-sided light emitting LED chip according to the present invention is formed by stacking a P-type semiconductor, an N-type semiconductor, and electrodes.

[0067] Below, refer to Figures 3 to 9 The structure of the double-sided light-emitting LED chip according to the first embodiment of the present invention is described in detail.

[0068] Figure 3 The double-sided LED chip according to the first embodiment of the present invention is separated and cut vertically into a three-dimensional diagram. According to the present invention, the double-sided LED chip includes a PN junction 10, a P-connecting portion 20 and an N-connecting portion 30. Figure 4 For a detailed description of the PN junction 10, refer to Figure 5 The P-connecting portion 20 will be described in detail. Figure 6 The N-direction connection portion 30 will be described in detail.

[0069] Figure 4 The cross-sectional view of the PN junction 10 according to the first embodiment of the present invention is shown. The PN junction 10 includes a P layer P, an active layer A and an N layer N, and is configured to emit light through an electroluminescent effect. Specifically, the PN junction 10 includes an N layer N, an active layer A and a P layer P, wherein the N layer N is formed of an N-type semiconductor and has a predetermined first thickness, the active layer A is arranged on the upper surface of the N layer (N) with a predetermined second thickness, and the P layer P is formed of a P-type semiconductor on the upper surface of the active layer (A) and has a predetermined third thickness.

[0070] The P layer P is a layer composed of a P-type semiconductor using holes as a charge transporter, and its material may vary depending on the optical characteristics of the target LED chip. In this specification, the description is based on P-GaN.

[0071] The active layer A is a layer that emits light by combining electrons and holes, and in this specification, description is made based on the case of being formed of an InGaN or GaN layer.

[0072] The N layer N is a layer composed of an N-type semiconductor using free electrons as a charge transporter, and its material may vary depending on the optical characteristics of the target LED chip. In this specification, N-GaN is used as a reference for the description.

[0073] On the other hand, in the PN junction 10, heat is generated together with the light-emitting effect. Therefore, the PN junction 10 may have a mesa structure to promote heat generation by increasing the surface area of ​​each layer. Here, the "mesa structure" refers to a structure in which the surface of each layer is carved to a predetermined depth to form a plurality of islands, and the edge portion of each island is a vertical cliff or slope. According to the first embodiment of the present invention, the PN junction includes a P-oriented mesa structure PMS formed on the surface of the P layer and an N-oriented mesa structure NMS formed on the surface of the N layer.

[0074] The P-direction mesa structure PMS is a mesa structure formed by carving from the upper surface of the P layer P to a predetermined depth of the N layer N, forming a plurality of P-direction islands 110. The number of the P-direction islands 110 may vary according to the design. Since the P-direction mesa structure PMS is carved from the upper surface of the P layer P through the active layer A to a predetermined depth of the N layer N, the heat generated in each layer can be effectively released.

[0075] The N-oriented mesa structure NMS is a mesa structure formed by carving from the lower surface of the N layer N to a predetermined depth, and forms a plurality of N-oriented islands 120. The number of the N-oriented islands 120 may vary according to the design. Since the thickness of the N layer N is generally thicker than that of the P layer P, the N-oriented mesa structure NMS is formed only in the N layer N.

[0076] In addition, when the side of the PN junction 10 and the side of the P-oriented mesa structure PMS are bonded to a member formed of metal, the charge moves through the above-mentioned member instead of the P layer P, the active layer A and the N layer, so there is a problem that the normal function of the LED chip may be disturbed. In order to prevent this, a P-oriented insulating portion 210 and an N-oriented insulating portion 220 may be provided.

[0077] The P-direction insulating portion 210 has a film-like structure provided on the outer surface of the PN junction 10 and the outer surface of the P-direction mesa structure PMS. Silicon dioxide (SiO2) or silicon nitride (SiN x ) can be used as the material of the P-direction insulating portion 210.

[0078] The N-type insulating portion 220 has a film-like structure that is provided in contact with the lower surface of the P-type insulating portion 210 to insulate the edge of the N-type layer N. Silicon dioxide (SiO2) or silicon nitride (SiN x ) can be used as the material of the N-directional insulating portion 220.

[0079] The P-direction insulating portion 210 and the N-direction insulating portion 220 are disposed to be in contact with each other, thereby having an effect that the PN junction 10 is insulated so that only the upper surface of the P layer P and the upper surface of the N layer N are exposed.

[0080] Figure 51 is a cross-sectional view of a P-direction connection portion 20 according to a first embodiment of the present invention. The P-direction connection portion 20 is configured to be disposed on the upper surface of the P layer P, connect the electrode to the P layer P, protect the upper surface of the PN junction 10, and convert the P-direction luminescent color. Specifically, the P-direction connection portion 20 includes a P-direction ohmic contact electrode 310, a P connection electrode 610, and a P-direction encapsulation material layer 710.

[0081] The P-direction ohmic contact electrode 310 is configured to form an ohmic contact with the P layer P. Specifically, the P-direction ohmic contact electrode 310 is formed by being deposited with a predetermined thickness on the upper surface of the P layer P and the upper surface of the P-direction insulating portion 210, and forms an ohmic contact with each P-direction island 110. Indium tin oxide (ITO), nickel aluminum alloy, nickel platinum alloy, etc. can be used as the P-direction ohmic contact electrode 310 according to the present embodiment.

[0082] The P-direction encapsulation material layer 710 is configured to protect the upper surface of the PN junction 10 and convert the P-direction luminous color. Specifically, the P-direction encapsulation material layer 710 is arranged on the upper surface of the P-direction ohmic contact electrode 310 to convert the color of the transmitted light. However, since the P connection electrode 610 must be connected to the P-direction ohmic contact electrode 310, the P-direction encapsulation material layer 710 is arranged on the upper surface of the P-direction ohmic contact electrode 310, and is formed so that the upper surface edge of the P-direction ohmic contact electrode 310 is exposed. The material of the P-direction encapsulation material layer 710 can be a mixture of ordinary phosphor and silicon, or silicon, phosphor in glass (PIG) ​​or remote phosphor (Remote Phosphor).

[0083] The P connection electrode 610 is configured to be connected to the P-direction ohmic contact electrode 310 to serve as an anode. Specifically, the P connection electrode surrounds the side of the P-direction encapsulation material layer 710 and is connected to the upper surface edge of the P-direction ohmic contact electrode 310. In addition, the P connection electrode 610 serves as a reflector to prevent light from escaping through the side of the P-direction encapsulation material layer 710. As a material for the P connection electrode 610, one of alloys or metals such as Ti / Ag, Ti / Al, Ti / Au, Ag, Al, Cu, Ni, Ti / Al / Ni / Au or Cr / Ni / Au can be used.

[0084] On the other hand, due to the characteristics of the materials, the PN junction 10, the P-direction ohmic contact electrode 310 and the P-direction packaging material layer 710 are easily damaged, and the P-connection electrode 610 is set thinner, so it cannot play a role in protecting the P-direction packaging material layer 710. In order to solve this problem, the P-direction connection part 20 may include a P-direction support metal part 510. Specifically, the P-direction support metal part 510 is arranged on the outer side of the P-direction insulating part 210, the P-direction ohmic contact electrode 310 and the P-connection electrode 610 to protect the structure of the PN junction 10 and the P-direction connection part 20. As the P-direction support metal part 510, one of the metals such as Cu, CuW, Ni or Au can be used.

[0085] Furthermore, a P-direction seed metal 410 may be provided to form the P-direction support metal portion 510. Specifically, the P-direction seed metal 410 is coated on the outer side surfaces of the P-direction insulating portion 210 and the P-direction ohmic contact electrode 310 in a thin film, so that the P-direction support metal portion 510 may be formed by means of an electroplating process of the P-direction seed metal 410.

[0086] Figure 6 1 is a cross-sectional view showing an N-direction connection portion 30 according to a first embodiment of the present invention. The N-direction connection portion 30 is configured to be disposed on the lower surface of the N layer N to connect the electrode to the N layer N, protect the lower surface of the PN junction 10, and convert the N-direction luminescent color. Specifically, the N-direction connection portion 30 includes an N-direction ohmic contact electrode 320, an N-connection electrode 620, and an N-direction encapsulation material layer 720.

[0087] The N-direction ohmic contact electrode 320 is configured to form an ohmic contact with the N-layer N. Specifically, the N-direction ohmic contact electrode 320 is formed by depositing with a predetermined thickness on the lower surface of the N-layer PN and the lower surface of the N-direction insulating portion 220, and forms an ohmic contact with each N-direction island 120. On the other hand, unlike the P-direction ohmic contact electrode 310, an opaque alloy material such as Ti / Al / Ni / Au or Cr / Ni / Au can be used as the N-direction ohmic contact electrode 320. Therefore, the N-direction ohmic contact electrode 320 has an N-direction branch structure NBS to expose a portion of the lower surface of the N-layer N. Here, the "branch structure" refers to a structure including an edge portion and a branch portion extending from the edge portion to the inner direction.

[0088] Figure 7 FIG. 2 is a plan view showing an N-directional ohmic contact electrode 320 according to a first embodiment of the present invention. Figure 7, the N-direction branch structure NBS will be described in detail: an N-ohm edge portion 321 in the form of a square edge is formed at the edge portion of the lower surface of the N layer N, and an N-ohm branch portion 322 extending from the above-mentioned N-ohm edge portion 321 in the inner direction and branching into a plurality of branches is formed in each N-direction mesa structure NMS. The N-ohm edge portion 321 is configured to be connected to the N connection electrode 620 to be described below, and the N-ohm branch portion 322 is configured to extend from the above-mentioned N-ohm edge portion 321 and connect to the N-direction mesa structure NMS so as to widen the contact area with the N layer N.

[0089] However, in Figures 2 to 6 In the figure, although for the sake of simplicity, the three N-oriented mesa structures NMS and the three N-ohmic branches 322 are provided, and the relative width of each N-oriented mesa structure NMS relative to the entire PN junction 10 is shown as a reference, in fact, Figure 7 As shown, a greater number of N-oriented mesa structures NMS and N ohmic branch portions 322 may be provided, and each of the N-oriented mesa structures NMS may have a relatively fine width relative to the entire PN junction 10 .

[0090] The N-direction encapsulation material layer 720 is configured to protect the lower surface of the PN junction 10 and convert the N-direction luminous color. Specifically, the N-direction encapsulation material layer 720 is arranged on the lower surface of the N-direction ohmic contact electrode 320 to convert the color of the transmitted light. However, since the N connection electrode 620 must be connected to the N-direction ohmic contact electrode 320, the N-direction encapsulation material layer 720 is arranged on the lower surface of the N-direction ohmic contact electrode 320, so that the lower surface edge of the N-direction ohmic contact electrode 320 is exposed. The lower edge is formed to be exposed. The material of the N-direction encapsulation layer 720 can be a mixture of ordinary phosphor and silicon, or silicon, phosphor in glass (PIG) ​​or remote phosphor (Remote Phosphor).

[0091] The N connection electrode 620 is configured to be connected to the N-direction ohmic contact electrode 320 to serve as a cathode. Specifically, the N connection electrode surrounds the side of the N-direction encapsulation material layer 720 and is connected to the lower surface edge of the N-direction ohmic contact electrode 320. In addition, the N connection electrode 620 serves as a reflector to prevent light from escaping through the side of the N-direction encapsulation material layer 720. As a material for the N connection electrode 620, one of alloys or metals such as Ti / Ag, Ti / Al, Ti / Au, Ag, Al, Cu or N can be used.

[0092] On the other hand, due to the characteristics of the materials, the N-direction ohmic contact electrode 320 and the N-direction packaging material layer 720 are easily damaged, and the N-connection electrode 620 is set thinner, so there is a possibility that it cannot play a role in protecting the N-direction packaging material layer 720. In order to solve this problem, the N-direction connection part 30 may include an N-direction support metal part 520. Specifically, the N-direction support metal part 520 is set on the outer side of the N-direction ohmic contact electrode 320 and the N-connection electrode 620 to protect the structure of the N-direction connection part 30. As the N-direction support metal part 520, one of the metals such as Cu, CuW, Ni or Au can be used.

[0093] In addition, in order to form the N-direction support metal portion 520, an N-direction seed metal 420 may be provided. Specifically, the N-direction seed metal 420 is coated on the outer side surface of the N-direction ohmic contact electrode 320 and the lower surface of the N-direction insulating portion 220 in a thin film, so that the N-direction support metal portion 520 may be formed by an electroplating process of the N-direction seed metal 420.

[0094] Figure 8 The cross-sectional view is a view showing the connection relationship between the PN junction 10, the P-connection portion 20 and the N-connection portion 30 according to the first embodiment of the present invention. The P-connection portion 20 is configured to be arranged on the upper surface of the P layer P to connect the electrode to the P layer P, protect the upper surface of the PN junction 10, and convert the P-light emission color. The N-connection portion 30 is configured to be arranged on the lower surface of the N layer N to connect the electrode to the N layer N, protect the lower surface of the PN junction 10, and convert the N-light emission color. As a result, the LED chip composed of a single PN junction 10 emits light on both sides through the P-connection portion 20 and the N-connection portion 30.

[0095] Below, refer to Figures 9 to 44 A method for manufacturing a double-sided light-emitting LED chip according to a first embodiment of the present invention is described in detail.

[0096] Fig. 9 FIG. 1 is a flow chart showing a method for manufacturing a double-sided light-emitting LED chip according to a first embodiment of the present invention.

[0097] According to the present invention, the manufacturing method of the double-sided light-emitting LED chip includes: a first step (S100), forming a PN junction 10 on the upper surface of the substrate; a second step (S200), forming a P-direction connecting portion 20; a third step (S300), applying an adhesive and attaching a supporting substrate; a fourth step (S400), separating the substrate; a fifth step (S500), inverting the top and bottom of the chip array; a sixth step (S600), forming an N-direction LED structure; a seventh step (S700), removing the supporting substrate and the adhesive; and an eighth step (S800), cutting the chip array into individual chips.

[0098] Fig.101 is a cross-sectional view showing a first step ( S100 ) of forming a PN junction on the upper surface of a substrate Sub1 according to the first embodiment of the present invention.

[0099] The first step (S100) is a step of forming semiconductor layers for LEDs on the upper surface of the substrate Sub1, and forming the N layer N, the active layer A and the P layer P in the order of the N layer N, the active layer A and the P layer P on the upper surface of the substrate Sub1. Each layer of the N layer N, the active layer A and the P layer P can be formed by epitaxial growth (EPI growth) using equipment such as metal-organic chemical vapor deposition (MOCVD).

[0100] The substrate Sub1 is a substrate on which a semiconductor is grown to form an LED, and is made of a single crystal substrate such as sapphire (Al2O3), Si or SiC, etc. In this description, a sapphire substrate having a predetermined thickness is used as a reference.

[0101] Fig.11 1 is a flowchart showing the second step ( S200 ) of forming the P-direction connecting portion 20 according to the first embodiment of the present invention.

[0102] The second step (S200) is a step of forming an electrode structure and a packaging material structure on the upper surface of the P layer. Specifically, the second step (S200) includes a P-direction mesa etching step (S210), an isolation etching step (S220), a P-direction insulation treatment (passivation) step (S230), a P-direction ohmic contact electrode 310 forming step (S240), a P-direction selective gold plating step (S250), a P-direction connection electrode 610 forming step (S260) and a P-direction packaging material layer 710 forming step (S270).

[0103] Fig.12 2 is a cross-sectional view showing the P-direction mesa etching step ( S210 ) according to the first embodiment of the present invention.

[0104] The P-oriented mesa etching step (S210) is a step for forming a P-oriented mesa structure PMS, that is, a step of engraving from the upper surface of the P layer P to a predetermined depth of the N layer N. Specifically, by a dry etching method such as reactive-ion etching (RIE) or inductively coupled plasma etching (ICP), a portion corresponding to a predetermined pattern is engraved from the upper surface of the P layer P to a predetermined first depth. In this embodiment, the mesa structure of forming a plurality of P-oriented islands 110 is used as a reference for description.

[0105] Fig.13 2 is a cross-sectional view showing the separation etching step (S220) according to the first embodiment of the present invention.

[0106] The separation etching step (S220) is a step of etching and removing the individual chips in order to manufacture multiple chips by horizontally and vertically separating the P layer P, the active layer A and the N layer N. The accompanying drawings of this specification show a single chip in an array (Array) composed of multiple chips, wherein the outside of the single chip is separated and removed by etching. In the following, the substrate portion exposed by the separation etching step will be described as a separation portion. In the separation etching step, a dry etching method such as reactive-ion etching (RIE) or inductively coupled plasma etching (ICP) can be used.

[0107] Fig.14 2 is a cross-sectional view showing the P-direction insulation processing step ( S230 ) according to the first embodiment of the present invention.

[0108] The P-direction insulation processing step (S230) is a step of forming the P-direction insulation portion 210. Specifically, an insulation film is deposited with a predetermined fourth thickness on the entire surface of the substrate Sub1 and the chip, and then the insulation film corresponding to the portion of each P-direction island 110 is removed so that the upper surface of each P-direction island 110 is exposed.

[0109] Fig.15 2 is a cross-sectional view showing the step ( S240 ) of forming the P-directional ohmic contact electrode 310 according to the first embodiment of the present invention.

[0110] The step of forming the P-direction ohmic contact electrode 310 (S240) is a step of forming the P-direction ohmic contact electrode 310 on the upper surface of the PN junction 10. Specifically, the P-direction ohmic contact electrode 310 is deposited on the upper surface of the PN junction 10 with a predetermined fifth thickness, and the formed P-direction ohmic contact electrode 310 is in contact with the upper surface of each P-direction island 110.

[0111] Fig.16 1 is a flow chart showing the P-direction selective gold plating step ( S250 ) according to the first embodiment of the present invention.

[0112] The P-direction selective gold plating step (S250) is a step of forming the P-direction supporting metal portion 510. Specifically, the P-direction selective gold plating step (S250) includes a P-direction seed metal 410 forming step (S251), a P-direction photoresist 511 forming step (S252), a P-direction gold plating step (S253) and a P-direction photoresist removing step (S254).

[0113] Fig.17 1 is a cross-sectional view showing the step ( S251 ) of forming the P-direction seed metal 410 according to the first embodiment of the present invention.

[0114] The step (S251) of forming the P-direction seed metal 410 is a step of coating the seed metal required for the electroplating process used in the P-direction gold plating step (S253) described below. Specifically, after the seed metal is coated on the upper surface of the substrate and the PN junction 10, the portion corresponding to the upper surface of the PN junction 10 is removed by etching and lifting off processes. Therefore, the upper surface of the P-direction ohmic contact electrode 310 is exposed.

[0115] Fig.18 2 is a cross-sectional view showing the step ( S252 ) of forming the P-type photoresist 511 according to the first embodiment of the present invention.

[0116] The step of forming the P-direction photoresist 511 (S252) is a step of forming the P-direction photoresist 511 by selective gold plating of photolithography. Specifically, the photoresist 511 is formed on the upper surface of the PN junction 10 so that the upper surface portion of the PN junction 10 is not gold plated. Therefore, only the P-direction seed metal 410 is exposed.

[0117] Fig.19 1 is a cross-sectional view showing a P-directional gold plating step according to the first embodiment of the present invention.

[0118] The P-direction gold plating step (S253) is a step of forming the P-direction support metal portion 510 by means of an electroplating process through the exposed P-direction seed metal 410. Specifically, through the electroplating process, the P-direction support metal portion 510 is formed only on the exposed P-direction seed metal 410 portion, and the photoresist 511 is used to prevent the PN junction 10 from being damaged during the electroplating process.

[0119] Fig. 20 2 is a cross-sectional view showing the P-type photoresist removal step (S254) according to the first embodiment of the present invention.

[0120] The P-direction photoresist removal step (S254) is a step of removing the photoresist 511 used for the selective gold plating. Therefore, the upper surface of the P-direction ohmic contact electrode 310 is exposed again.

[0121] Fig.21 2 is a cross-sectional view showing the step ( S260 ) of forming the P connection electrode 610 according to the first embodiment of the present invention.

[0122] The step of forming the P connection electrode 610 (S260) is a step of forming the P connection electrode 610 connected to the P-direction ohmic contact electrode 310. Specifically, the P connection electrode 610 is formed to be in contact with the upper surface edge of the P-direction ohmic contact electrode 310 and in contact with the inner side wall of the P-direction support metal portion 510. In addition, it is preferably formed to be exposed with a predetermined width on the upper surface of the P-direction support metal portion 510 so as to be easily connected to a power source.

[0123] On the other hand, since the P-direction ohmic contact electrode 310 has a high resistance, charge transfer with the P-connection electrode 610 may not be easy, and thus the P-connection electrode 610 may have a P-direction branch structure PBS for increasing the contact area with the P-direction ohmic contact electrode 310. Here, as described in the N-direction branch structure NBS, the "branch structure" refers to a structure including an edge portion and a branch portion extending from the edge portion toward the inner direction.

[0124] Fig. 22 A cross-sectional view showing a step (S260') of forming a P connection electrode 610' having a branch structure according to another embodiment of the present invention, Fig.23 FIG. 1 is a plan view showing a P connection electrode 610' having a branch structure according to another embodiment of the present invention. Fig. 22 In the figure, although for the sake of simplicity, the three P electrode branch portions 612 are provided, and the relative width of each P electrode branch portion 612 relative to the entire PN junction 10 is shown as a reference, in fact, Fig.23 As shown, a greater number of P-electrode branches 612 may be provided, and each of the P-electrode branches 612 may have a relatively fine width relative to the entire PN junction 10 .

[0125] Reference Fig. 22 and Fig.23, the P-direction branch structure PBS is described in detail: the P-electrode edge portion 611 is formed to be in contact with the upper surface edge of the P-direction ohmic contact electrode, and is in contact with the inner side wall and the upper surface of the P-direction electroplated metal. In addition, a P-electrode branch portion 612 is formed on the upper surface of the P-direction ohmic contact electrode 310, which extends from the above-mentioned P-electrode edge portion 611 inwardly and branches into a plurality of branches. The P-electrode edge portion 611 and the P-electrode branch portion 612 are respectively formed to be in contact with the P-direction ohmic contact electrode 310, so that charge transfer becomes easy. In addition, when the P-direction branch structure PBS and the N-direction branch structure NBS are symmetrically arranged, the diffusion effect is increased.

[0126] Fig.24 2 is a cross-sectional view showing the step ( S270 ) of forming the P-oriented encapsulation material layer 710 according to the first embodiment of the present invention.

[0127] The P-direction encapsulation material layer 710 forming step (S270) is a step of forming the P-direction encapsulation material layer 710 on the upper surface of the P-direction ohmic contact electrode 310. Specifically, the P-direction encapsulation material layer 710 is formed by applying an encapsulation material in a space surrounded by the P-direction ohmic contact electrode 310 and the P connection electrode 610.

[0128] Fig.25 2 is a cross-sectional view showing the third step ( S300 ) of applying the adhesive G and attaching the supporting substrate Sub2 according to the first embodiment of the present invention.

[0129] The third step S300 of applying adhesive G and attaching support substrate Sub2 is a step of attaching support substrate Sub2 to the upper surface of P-direction connection part 20 for the steps to be described below. As support substrate Sub2, one of glass, silicon, metal and ceramic can be used.

[0130] Fig.26 4 is a cross-sectional view showing a fourth step ( S400 ) of separating the substrate Sub1 according to the first embodiment of the present invention.

[0131] The fourth step ( S400 ) of removing the substrate is a step of separating and removing the substrate Sub1 in order to form the N-direction connection portion 30 on the lower surface of the N layer N. The substrate Sub1 can be separated by laser lift-off and chemical lift-off methods.

[0132] Fig. 27 1 is a cross-sectional view showing a fifth step ( S500 ) of flipping the top and bottom of the chip array according to the first embodiment of the present invention.

[0133] The fifth step (S500) of reversing the chip array is a step of reversing the chip array to facilitate the formation of the N-direction connection portion 30. Hereinafter, the reversed N-layer N direction is defined as the upper side, and the reversed P-layer P direction is defined as the lower side.

[0134] Fig.28 1 is a flowchart showing the sixth step ( S600 ) of forming the N-direction connecting portion 30 according to the first embodiment of the present invention.

[0135] The sixth step (S600) is a step of forming an electrode structure and a packaging material structure on the upper surface of the N layer. Specifically, the sixth step (S600) includes an N-direction mesa etching step (S610), an N-direction insulation treatment (passivation) step (S620), an N-direction ohmic contact electrode 320 forming step (S630), an N-direction selective gold plating step (S640), an N-direction connection electrode 620 forming step (S650) and an N-direction packaging material layer 720 forming step (S660).

[0136] Fig.29 4 is a cross-sectional view showing the N-directional mesa etching step ( S610 ) according to the first embodiment of the present invention.

[0137] The N-direction mesa etching step (S610) is a step for forming an N-direction mesa structure NMS, that is, a step for engraving a predetermined depth from the upper surface of the N layer N. Specifically, a portion corresponding to a predetermined pattern is engraved at a predetermined second depth from the upper surface of the N layer N by a dry etching method such as reactive-ion etching (RIE) or inductively coupled plasma etching (ICP). In this embodiment, the mesa structure of forming a plurality of N-direction islands 120 is used as a reference for description.

[0138] Fig.30 FIG. 5 is a cross-sectional view showing the N-directional insulation processing step ( S620 ) according to the first embodiment of the present invention.

[0139] The N-direction insulation processing step (S620) is a step of forming the N-direction insulation part 220. Specifically, an insulation film is deposited with a predetermined fourth thickness on the entire surface of the substrate Sub1 and the chip, and then the insulation film corresponding to the portion of the upper surface of each N layer N is removed, so that the upper surface of each N layer N is exposed. Unlike the case of the P-direction insulation part 210, the insulation film is not formed on the N-direction mesa structure NMS.

[0140] Fig.311 is a cross-sectional view showing the step ( S630 ) of forming the N-directional ohmic contact electrode 320 according to the first embodiment of the present invention.

[0141] The step of forming the N-direction ohmic contact electrode 320 (S630) is a step of forming the N-direction ohmic contact electrode 320 on the upper surface of the PN junction 10. Specifically, the N-direction ohmic contact electrode 320 is deposited on the upper surface of the PN junction 10 with a predetermined fifth thickness, and is formed to have the above-mentioned N-direction branch structure NBS, so that each N-direction ohmic branch portion 322 is connected to the N-direction mesa structure NMS.

[0142] Fig.32 FIG. 6 is a flow chart showing the N-directional selective gold plating step ( S640 ) according to the first embodiment of the present invention.

[0143] The N-direction selective gold plating step (S640) is a step of forming the N-direction supporting metal portion 520. Specifically, the N-direction selective gold plating step (S640) includes an N-direction seed metal (420) forming step (S641), an N-direction photoresist 521 forming step (S642), an N-direction gold plating step (S643) and an N-direction photoresist removing step (S644).

[0144] Fig.33 1 is a cross-sectional view showing the step ( S641 ) of forming the N-directional seed metal 420 according to the first embodiment of the present invention.

[0145] The N-direction seed metal 420 forming step (S641) is a step of coating the seed metal required for the electroplating process used in the N-direction gold plating step (S643) to be described below. Specifically, after the seed metal is coated on the upper surface of the substrate and the PN junction 10, the portion corresponding to the upper surface of the PN junction 10 is removed by etching and liftoff processes. Therefore, the upper surfaces of the N-direction ohmic contact electrode 320 and each N-direction island 120 are exposed.

[0146] Fig.34 1 is a cross-sectional view showing the step (S642) of forming the N-directional photoresist 521 according to the first embodiment of the present invention.

[0147] The step of forming the N-direction photoresist 521 (S642) is a step of forming the N-direction photoresist 521 by selective gold plating of photolithography. Specifically, the photoresist 521 is formed on the upper surface of the PN junction 10 so that the upper surface portion of the PN junction 10 is not gold plated. Therefore, only the N-direction seed metal 420 is exposed.

[0148] Fig.35 2 is a cross-sectional view showing the N-directional gold plating step (S643) according to the first embodiment of the present invention.

[0149] The N-direction gold plating step (S643) is a step of forming the N-direction support metal portion 520 by means of an electroplating process through the exposed N-direction seed metal 420. Specifically, through the electroplating process, the N-direction support metal portion 520 is formed only on the exposed N-direction seed metal 420 portion, and the photoresist 521 is used to prevent the PN junction 10 from being damaged during the electroplating process.

[0150] Fig.36 1 is a cross-sectional view showing the N-directional photoresist removal step (S644) according to the first embodiment of the present invention.

[0151] The N-directional photoresist removal step (S644) is a step of removing the photoresist 521 used for the selective gold plating. Therefore, the upper surface of the N-directional ohmic contact electrode 320 and the upper surface of each N-directional island 120 are exposed again.

[0152] Fig.37 1 is a cross-sectional view showing a step of forming the N-connection electrode 620 according to the first embodiment of the present invention ( S650 ).

[0153] The step (S650) of forming the N connection electrode 620 is a step of forming the N connection electrode 620 connected to the N-direction ohmic contact electrode 320. Specifically, the N connection electrode 620 is formed to be in contact with the upper surface of the N-ohmic edge portion 321 and to be in contact with the inner side wall of the N-direction support metal portion 520. In addition, it is preferably formed to be exposed with a predetermined width on the upper surface of the N-direction support metal portion 520 so as to be easily connected to a power source.

[0154] Fig.38 4 is a cross-sectional view showing the step ( S660 ) ​​of forming the N-directional encapsulation material layer 720 according to the first embodiment of the present invention.

[0155] The N-directional encapsulation material layer 720 forming step (S660) is a step of forming the N-directional encapsulation material layer 720 on the upper surface of the N-directional ohmic contact electrode 320 and the upper surface of the N layer N. Specifically, the N-directional encapsulation material layer 720 is formed by applying an encapsulation material in a space surrounded by the N-directional ohmic contact electrode 320, the N layer N, and the N connection electrode 620.

[0156] The seventh step ( S700 ) of removing the support substrate Sub2 and the adhesive G is a step of re-exposing the P-direction connection portion 20 by removing the support substrate Sub2 and the adhesive G attached to the lower surface of the P-direction connection portion 20 in order to form the N-direction connection portion 30 .

[0157] The eighth step (S800) of separating a single chip by cutting the chip array is a step of cutting and separating the plurality of chips forming the array, respectively. Each single chip can be cut by a laser scribing process or a dicing process.

[0158] Fig.39 The cross-sectional view of the double-sided LED chip after removing the adhesive and the support substrate according to the first embodiment of the present invention is shown. After the seventh step (S700) and the eighth step (S800) described above, a single double-sided LED chip is completed.

[0159] On the other hand, at the same time, as a second embodiment of the present invention, a double-sided light-emitting LED chip with a flat structure without a P-oriented mesa structure PMS and / or an N-oriented mesa structure NMS can be provided. Specifically, as a second embodiment of the present invention, a double-sided light-emitting LED chip can be provided in which the N layer N, the active layer A and the P layer P are arranged in a planar structure without a mesa structure, and each P-oriented island 110 and each N-oriented island are not formed.

[0160] Below, refer to Figures 40 to 44 The second embodiment of the present invention will be described in detail.

[0161] Fig.40 FIG. 2 is a cross-sectional view showing a double-sided light-emitting LED chip according to a second embodiment of the present invention. Fig.39 The double-sided light-emitting LED chip according to the first embodiment shown in the figure is different in that a deformed P-direction insulating portion 210' is provided to exclude the insulating film formed on the P-direction mesa structure PMS in the P-direction insulating processing step (S230) according to the first embodiment. In addition, the N-direction ohmic branch portion 322 formed on the N-direction mesa structure NMS in the N-direction ohmic contact electrode 320 forming step (S630) according to the first embodiment is formed as a deformed N-direction branch structure NBS' connected to the N upper surface of the N layer, instead of being formed on the N-direction mesa structure NMS.

[0162] Fig.41The flowchart is a flowchart showing the step 2-1 (S200') of forming the P-direction light-emitting portion 20' according to the second embodiment of the present invention. The step 2-1 (S200') is a step that replaces the second step (S200) of the first embodiment. In the second step (S200), the P-direction mesa etching step (S210) is excluded, and the P-direction insulation processing step (S230) is replaced by a deformed P-direction insulation processing step (S230'). In addition, as in the first embodiment, it includes a separation etching step (S220), a P-direction ohmic contact electrode 310 forming step (S240), a P-direction selective gold plating step (S250), a P-direction connection electrode 610 forming step (S260) and a P-direction packaging material layer 710 forming step (S270).

[0163] Fig.42 A cross-sectional view showing the second P-direction insulation processing step (S230') according to the second embodiment of the present invention. The second P-direction insulation processing step (S230') is characterized in that the insulation film formed on the P-direction mesa structure PMS in the P-direction insulation processing step (S230) of the above-mentioned first embodiment is excluded. According to the second embodiment of the present invention, since the mesa structure is not formed, only the chip separation portion is subjected to insulation treatment. Specifically, after the insulation film is deposited on the entire surface of the substrate Sub1 and the chip with a predetermined fourth thickness, the insulation film corresponding to the portion of the upper surface of the P layer P is removed.

[0164] Fig.43 The flowchart of the 6-1 step (S600') of forming the N-direction connection portion 30 according to the second embodiment of the present invention is shown. The 6-1 step (S600') is a step that replaces the 6th step (S600) of the above-mentioned first embodiment. In the above-mentioned 6th step (S600), the N-direction mesa etching step (S610) is excluded, and the N-direction ohmic contact electrode 320 forming step (S630') is replaced by the deformed N-direction ohmic contact electrode 320' forming step (S630). In addition, as in the first embodiment, it includes the N-direction insulation treatment step (S620), the N-direction selective gold plating step (S640), the N-connection electrode 620 forming step (S650) and the N-direction packaging material layer 720 forming step (S660).

[0165] Fig.44 1 is a cross-sectional view showing a deformed N-direction ohmic contact electrode 320' forming step (S630') according to a second embodiment of the present invention. In the deformed N-direction ohmic contact electrode 320' forming step (S630'), the N-direction ohmic contact electrode 320 in the N-direction ohmic contact electrode 320 forming step (S630) of the first embodiment is formed into a deformed N-direction branch structure NBS' connected to the N upper surface of the N layer, instead of being formed in the N-direction mesa structure NMS.

[0166] Industrial Applicability

[0167] According to the present invention, a single chip can be used in fields requiring double-sided light emission, and can realize miniaturization of applicable equipment, improve power efficiency, and have the effect of reducing manufacturing costs.

[0168] Furthermore, the double-sided light-emitting LED chip manufactured according to the present invention can be manufactured by a batch process, and thus does not require a separate packaging process.

[0169] Also, the double-sided light-emitting LED chip according to the present invention has the effect of improving light efficiency by reducing the total internal reflection of light generated by the LED.

Claims

1. A double-sided light-emitting LED chip, which is an LED chip utilizing the electroluminescent effect of a PN junction (10) including a P layer (P) and an N layer (N) disposed below the P layer (P), wherein the double-sided light-emitting LED chip is characterized in that: The light is emitted toward the upper side of the P layer (P) and the lower side of the N layer (N), respectively. A P-connecting portion (20) is provided on the upper surface of the P layer (P). An N-direction connection portion (30) is provided on the lower surface of the N layer (N). The P-connecting portion (20) provides power connection to the P layer (P). The N-direction connection portion (30) provides power connection to the N layer (N). The PN junction (10) is protected from external environment by the P-connection part (20) and the N-connection part (30). The P-connecting portion (20) includes a P-connecting electrode (610) disposed on the upper surface of the P layer (P). The P layer (P) is connected to a power source from the upper side through the P connection electrode (610). The N-direction connection portion (30) includes an N-connection electrode (620) disposed on the lower surface of the N layer (N). The N layer (N) is connected to a power source from the bottom through the N connection electrode (620). It includes a P-direction insulating portion (210) and an N-direction insulating portion (220), The P-direction insulating portion (210) is formed as a thin film with a predetermined thickness on the outer side of the PN junction (10) and the upper surface edge of the P layer (P). The N-direction insulating portion (220) is formed as a thin film with a predetermined thickness on the lower surface of the P-direction insulating portion (210) and the lower surface edge of the N layer (N). The P-direction connecting portion (20) comprises: A P-oriented ohmic contact electrode (310), wherein the P-oriented ohmic contact electrode (310) is disposed between the P layer (P) and the P connection electrode (610) and forms an ohmic contact between the P layer (P) and the P connection electrode (610); as well as A P-direction supporting metal portion (510), the P-direction supporting metal portion (510) being arranged on the outer side of the P-direction insulating portion (210), the P-direction ohmic contact electrode (310) and the P-connecting electrode (610) to protect the structure of the PN junction (10) and the P-direction connecting portion (20), The N-direction connection portion (30) includes an N-direction ohmic contact electrode (320), which is disposed between the N layer (N) and the N connection electrode (620) and forms an ohmic contact between the N layer (N) and the N connection electrode (620).

2. The double-sided light-emitting LED chip according to claim 1, characterized in that: The P layer (P) includes at least one P-oriented mesa structure (PMS), and the at least one P-oriented mesa structure (PMS) is formed by carving from the upper surface of the P layer (P) to a predetermined depth of the N layer (N). The N layer (N) includes at least one N-oriented mesa structure (NMS), and the at least one N-oriented mesa structure (NMS) is formed by engraving a predetermined depth on the lower surface of the N layer (N).

3. The double-sided light-emitting LED chip according to claim 1, characterized in that: The N-directional ohmic contact electrode (320) has a branch structure (BS).

4. The double-sided light-emitting LED chip according to claim 1, characterized in that: The P connection electrode (610) has a wall having a predetermined upward height along the edge from the upper surface of the P layer (P), The N connection electrode (620) has a wall having a predetermined downward height along the edge from the lower surface of the N layer (N), The P connection electrode (610) is used as a reflector for P-directional light emission. The N connection electrode (620) is used as a reflector for N-directional light emission.

5. The double-sided light-emitting LED chip according to claim 4, characterized in that: The P-direction connection portion (20) includes a P-direction encapsulation material layer (710), and the P-direction encapsulation material layer (710) is arranged in a space surrounded by the upper surface of the P layer (P) and the P connection electrode (610) to protect the P layer (P) and convert the P-direction luminescent color. The N-direction connection part (30) includes an N-direction packaging material layer (720), and the N-direction packaging material layer (720) is arranged in a space surrounded by the upper surface of the N layer (N) and the N connection electrode (620) to protect the N layer (N) and convert the N-direction luminescent color.

6. The double-sided light-emitting LED chip according to claim 1, characterized in that: It also includes a supporting metal part (500), and the supporting metal part (500) is plated on the outer side surfaces of the PN junction (10), the P-direction connecting part (20) and the N-direction connecting part (30).

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