A flip-chip light emitting diode and lighting device

Abstract

The present invention provides a flip-chip light-emitting diode and a lighting device, wherein the first connecting electrode or the second connecting electrode of the light-emitting diode located on the first insulating layer has an electrode through hole, and the electrode through hole is filled with a second insulating layer. When a pin is used to act on the center of the light-emitting diode, the pin acts on the area where the electrode through hole is located, and directly acts on the second insulating layer. Since the metal is removed from the electrode through hole, the second insulating layer is prevented from being pulled and damaged when the pin acts on the metal electrode, and the chip failure problem caused by the rupture of the insulating layer is further avoided. At the same time, the present invention further improves the electrode arrangement, so as to achieve better expansion of the current, disperse the current diffusion distribution, make the light-emitting diode chip emit light evenly, and further improve the light-emitting brightness and reliability of the light-emitting diode chip.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor light emitting devices, and in particular to a flip-chip light emitting diode and a lighting device. Background Art

[0002] Flip chips have the advantages of no wire bonding, high light efficiency, and good heat dissipation, and are widely concerned and developed as a future development trend. The light-emitting surface of the flip chip is a sapphire substrate. The current flip-chip light-emitting diode chip needs to form an Ag reflector or a DBR reflector on the epitaxial layer as a reflective layer. Although the reflectivity of the DBR reflector is lower than that of the Ag reflector, its material is an insulating oxide material with stable chemical properties and high reliability in long-term use.

[0003] The flip-chip light-emitting diode with DBR reflector as the reflective layer can be further divided into two types. One type is suitable for small-sized chips, where the DBR reflective layer serves as an insulating protective layer, and the first pad and the second pad are directly formed on the surface of the DBR; the other type is suitable for large-sized chips, where an electrode layer with opposite electrical properties (such as the first electrode and the second electrode) is formed on the DBR reflective layer, and there is also an insulating layer on the electrode layer, such as a silicon oxide layer as an insulating layer, which also serves as a protective layer, and then the first pad and the second pad are arranged on the silicon oxide layer, which are electrically connected to the first electrode and the second electrode respectively. The second type of large-sized chip is more suitable for use in high-power lighting, backlighting, automotive and other fields.

[0004] For the second type of chip, during the chip transfer process, a pin is needed to act on the insulating layer between the first pad and the second pad of the chip to achieve the transfer. Due to the brittleness of the insulating layer, if the thickness of the insulating layer is insufficient at the location where the pin is placed, the insulating layer may easily break. Even if a stress buffer layer, such as a metal layer, is provided, the metal layer may easily tear the insulating layer, causing the chip to fail during use. Figure 1 As shown in FIG. 1 , when the ejector pin 30 is pressed against the middle area of ​​the light-emitting diode, since there is a first electrode 11 below the action area of ​​the ejector pin 30, the first electrode 11 will bend and deform under the pressure of the ejector pin 30, thereby pulling the second insulating layer 104, especially causing deformation or even cracks in the second insulating layer, such as Figure 2 As shown, the crack will cause the seal to fail, and the incoming water vapor will cause faults such as short circuits, ultimately leading to damage to the light-emitting diode.

[0005] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are described in the background technology section of the present application. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a flip-chip light emitting diode, which is used to solve the problem in the prior art that the electrode damages the insulating layer when the ejector pin acts.

[0007] In order to achieve the above-mentioned object and other related objects, the present invention provides a flip-chip light emitting diode, the light emitting diode comprising:

[0008] light emitting epitaxial layer;

[0009] A first insulating layer, covering the light-emitting epitaxial layer and around the sidewalls, wherein the first insulating layer has a plurality of through holes;

[0010] A first connection electrode and a second connection electrode having opposite electrical properties, which are located on the first insulating layer and are filled into the through holes of the first insulating layer to be electrically connected to the light-emitting epitaxial layer;

[0011] a second insulating layer, wherein the second insulating layer covers the light-emitting epitaxial layer and around the sidewalls thereof, and covers the first connecting electrode, the second connecting electrode and the first insulating layer;

[0012] Among them, the first connecting electrode or the second connecting electrode has an electrode through hole, the bottom of the electrode through hole is the first insulating layer, and the second insulating layer is also filled to the electrode through hole; and looking down at the light-emitting diode from top to bottom, the electrode through hole is located in the center of the light-emitting diode.

[0013] Optionally, the electrode through hole is circular, and its radius is 10-100 microns.

[0014] Optionally, the second insulating layer has a thickness of 0.1 to 1.5 microns.

[0015] Optionally, the thickness of the first insulating layer is greater than 2 microns.

[0016] Optionally, it further comprises a first pad and a second pad, which are located on the second insulating layer and fill in a plurality of through holes of the second insulating layer to electrically connect the first connecting electrode and the second connecting electrode respectively.

[0017] Optionally, it also includes a first contact electrode and a second contact electrode; a plurality of the first contact electrodes and a plurality of the second contact electrodes are located under the first insulating layer, the first connecting electrode fills in a through hole of the first insulating layer to connect the plurality of the first contact electrodes, and the second connecting electrode fills in a through hole of the first insulating layer to connect the plurality of the second contact electrodes.

[0018] Optionally, when looking down at the light emitting diode from above, the first connecting electrode is arranged around the second connecting electrode.

[0019] Optionally, the second connecting electrode is in the shape of two relatively wide regions and a relatively narrow region between the two relatively wide regions, and the relatively narrow region connects the two relatively wide regions.

[0020] Optionally, the relatively narrow area of ​​the second connecting electrode is located at the center of the light emitting diode and is formed with the electrode through hole for the ejector action area.

[0021] Optionally, the first connection electrodes and the second connection electrodes are both symmetrically distributed along a central axis.

[0022] Optionally, at least 50% of the vertical projection area of ​​the first pad falls within the one relatively wide area of ​​the second connecting electrode, and at least 50% of the vertical projection area of ​​the second pad falls within another relatively wide area of ​​the second connecting electrode.

[0023] Optionally, the light-emitting epitaxial layer includes a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer stacked in sequence.

[0024] Optionally, the first contact electrode and the second contact electrode are both dispersed in multiple locations; the first contact electrode includes multiple locations on the first conductive type semiconductor layer located at the periphery of the light-emitting epitaxial layer and multiple locations on the surface of the first conductive type semiconductor layer located in the holes inside the light-emitting epitaxial layer; the second contact electrode is in multiple locations, located on the second conductive type semiconductor layer.

[0025] The present invention also provides a lighting device, comprising the light emitting diode as described above.

[0026] As described above, the present invention provides a flip-chip light-emitting diode and a lighting device, wherein the first connecting electrode or the second connecting electrode of the light-emitting diode located on the first insulating layer has an electrode through hole, and the electrode through hole is filled with the second insulating layer. When a pin is used to act on the center of the light-emitting diode, the pin acts on the area where the electrode through hole is located, and directly acts on the second insulating layer. Since the metal is removed from the electrode through hole, the second insulating layer is prevented from being pulled and damaged when the pin acts on the metal electrode, and the chip failure problem caused by the rupture of the insulating layer is further avoided. At the same time, the present invention also makes further improvements to the electrode arrangement, so as to achieve better expansion of the current, disperse the current diffusion distribution, make the light-emitting diode chip emit light evenly, and further improve the light-emitting brightness and reliability of the light-emitting diode chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of a light emitting diode in the prior art.

[0028] Figure 2 The electron microscope photograph showing cracks generated by the action of a ejector pin in the prior art.

[0029] Figure 3 It is a schematic diagram showing the structure of the light emitting diode in the present invention.

[0030] Figure 4 It is a top view schematic diagram showing the division of the light emitting diode into the first area and the second area in the present invention.

[0031] Figure 5 A schematic top view of forming a transparent conductive layer in the second region is shown.

[0032] Figure 6 A schematic top view of forming a first contact electrode and a second contact electrode is shown.

[0033] Figure 7 A schematic top view of forming a first interconnection electrode and a second interconnection electrode is shown.

[0034] Figure 8 A schematic top view of forming a first pad and a second pad is shown.

[0035] Component number description

[0036] 11. First electrode

[0037] 12 First pad

[0038] 21. Second electrode

[0039] 22 Second pad

[0040] 23 Transparent conductive layer

[0041] 24 Barrier layer

[0042] 30 Electrode through hole

[0043] 50 Ejector pin

[0044] 101 Substrate

[0045] 102 Light-emitting epitaxial layer

[0046] 103 First insulation layer

[0047] 104 Second insulation layer

[0048] 110 First countertop

[0049] 111 first contact electrode

[0050] 112 first connection electrode

[0051] 211 second contact electrode

[0052] 212 second connection electrode

[0053] 100 District 1

[0054] 200 District 2

[0055] 1001 First Outer Zone

[0056] 1002 First inner zone

[0057] 2001 Second Subdivision

[0058] 2002 Central District

[0059] 1021 first conductive type semiconductor layer

[0060] 1023 Active layer

[0061] 1022 second conductivity type semiconductor layer DETAILED DESCRIPTION

[0062] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0063] For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional view showing the device structure will not be partially enlarged according to the general scale, and the schematic view is only an example, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional space dimensions of length, width and depth should be included.

[0064] For ease of description, spatial relational terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatial relational terms are intended to include other directions of the device in use or operation in addition to the directions depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or there can be one or more intervening layers. As used herein, "between..." means including the end point values.

[0065] In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0066] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and therefore the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0067] Embodiment 1

[0068] like Figure 3 As shown, the present invention provides a flip-chip light emitting diode, specifically comprising:

[0069] Light emitting epitaxial layer 102;

[0070] A first insulating layer 103, covering the light-emitting epitaxial layer 102 and around the sidewalls, wherein the first insulating layer 103 has a thickness of more than 1 micron and has a plurality of through holes;

[0071] A first connection electrode 112 and a second connection electrode 212 having opposite electrical properties are located on the first insulating layer 103 and are filled into through holes of the first insulating layer 103 to be electrically connected to the light-emitting epitaxial layer 102;

[0072] A second insulating layer 104, wherein the second insulating layer 104 covers the light-emitting epitaxial layer 102 and the sidewall thereof, and covers the first connecting electrode 112, the second connecting electrode 212 and the first insulating layer 103, wherein the second insulating layer has a plurality of through holes, and the thickness of the second insulating layer 104 is between 0.1 and 1.5 microns;

[0073] The first pad 12 and the second pad 22 are located on the second insulating layer 104 and are filled into a plurality of through holes of the second insulating layer 104 to electrically connect the first connection electrode 112 and the second connection electrode 212 respectively;

[0074] Among them, the connecting electrode 112 or the second connecting electrode 212 has an electrode through hole 30, the bottom of the electrode through hole 30 is the first insulating layer 103, and the second insulating layer 104 is also filled into the electrode through hole 30; and looking down at the light-emitting diode from top to bottom, the electrode through hole 30 is located in the center of the light-emitting diode.

[0075] Specifically, the light-emitting epitaxial layer 102 includes a first conductive type semiconductor layer 1021, an active layer 1023, and a second conductive type semiconductor layer 1022 stacked in sequence, the first electrode 11 is electrically connected to the first conductive type semiconductor layer 1021, the second electrode 21 is electrically connected to the second conductive type semiconductor layer 1022, the first electrode 11 includes a first connection electrode 112 and a first contact electrode 111, and the second electrode 21 includes a second connection electrode 212 and a second contact electrode 211. The light-emitting epitaxial layer 102 is formed on a substrate 101, and the substrate can be made of a transparent material, a semi-transparent material, or a non-transparent material. For example, it can be any one of silicon carbide, silicon, magnesium aluminum oxide, magnesium oxide, gallium nitride, and sapphire. In this embodiment, the substrate 101 is preferably a sapphire substrate. The upper surface of the substrate 101 can have a patterned structure (i.e., the protrusion shown in the figure), and the patterned structure can improve the external light extraction efficiency and the crystal quality of the epitaxial layer constituting the light-emitting epitaxial layer 102. As an example, the patterned structure on the upper surface of the substrate 101 may be formed into various shapes, such as a cone, a triangular pyramid, a hexagonal pyramid, a quasi-cone, and the like.

[0076] As an example, the first conductive type semiconductor layer 1021 and the second conductive type semiconductor layer 1022 have different conductive types, which can be n-type or p-type. For example, the first conductive type semiconductor layer 1021 is n-type and the second conductive type semiconductor layer 1022 is p-type. The active layer 1023 is a light-emitting layer where radiation recombination occurs, and can be a single quantum well layer or a multi-quantum well layer. The light-emitting wavelength of the active layer 1023 can be in the visible light range, such as red light, green light, blue light, or in the invisible light range, such as infrared light, which is not limited here. In this embodiment, the first conductive type semiconductor layer 1021 is n-type and the second conductive type semiconductor layer 1022 is p-type. Naturally, the first electrode 11 is an n-electrode and the second electrode 21 is a p-electrode.

[0077] The first electrode 11 is electrically connected to the first mesa 110 on the surface of the first conductive type semiconductor layer 1021. The first mesa 110 is also called MESA, which is a common structure in light-emitting diodes. It is usually obtained by etching the active layer 1023 and a part of the second conductive type semiconductor layer 1022 after the epitaxy is completed. The first mesa 110 removes part of the second conductive type semiconductor layer 1022 and the active layer 1023, exposing a part of the upper surface of the first conductive type semiconductor layer 1021. There can be multiple first mesas 110, and the first mesa 110 can be located inside the light-emitting epitaxial layer 102, or located at the edge area of ​​the light-emitting epitaxial layer 102, or located at both the inside and edge areas of the light-emitting epitaxial layer 102 to be used as an electrode connection.

[0078] Further, the first electrode 11 includes a first contact electrode 111 and a first connection electrode 112, and the second electrode 21 includes a second contact electrode 211 and a second connection electrode 212. As an example, the first contact electrode 111 and the second contact electrode 211 can be metal electrodes, for example, one or any combination of nickel, gold, chromium, titanium, platinum, palladium, chromium, iridium, aluminum, tin, indium, tin, copper, cobalt, iron, rhodium, zirconium, tungsten, and molybdenum; or transparent conductive materials, such as indium tin oxide (ITO), indium zinc oxide (IZO), aluminum-doped zinc oxide transparent conductive glass (AZO), etc. As a preferred embodiment, the first contact electrode 111 and the second contact electrode 211 both include a bottom layer (for example, Cr), a reflective layer (for example, Al) on the bottom layer, and a protective layer (for example, Ti, Pt, or Ni, etc.) on the reflective layer. The bottom layer can ensure the ohmic contact effect between the contact electrode and the light-emitting epitaxial layer 102, and the thickness of the bottom layer is within 10nm, thereby avoiding the influence on the reflectivity. There may be a plurality of the first contact electrode 111 and the second contact electrode 211 , and power supply to each contact electrode is achieved through the first connection electrode 112 and the second connection electrode 212 .

[0079] The first connection electrode 112 and the second connection electrode 212 may be a single layer or multiple layers made of at least one material selected from titanium, copper, chromium, nickel, gold, platinum, aluminum, titanium nitride, tantalum nitride or tantalum. A plurality of the first contact electrodes 111 and a plurality of the second contact electrodes 211 are located under the first insulating layer 103. The first connection electrode 112 is filled into the through hole of the first insulating layer 103 to connect the plurality of the first contact electrodes 111. The second connection electrode 212 is filled into the through hole of the first insulating layer 103 to connect the plurality of the second contact electrodes 211. The electrode through hole 30 is located at the portion of the first connection electrode 112 or the second connection electrode 212 located on the upper surface of the first insulating layer. Preferably, the first connection electrode 112 and the second connection electrode 212 have a reflective metal layer, which can effectively reflect the light radiated from the active layer 1023, and the reflective metal layer is, for example, an aluminum layer.

[0080] Specifically, the first connecting electrode 112 or the second connecting electrode 212 has an electrode through hole, the bottom of the electrode through hole is the first insulating layer 103, and the second insulating layer 104 fills the electrode through hole; and looking down at the light-emitting diode from top to bottom, the electrode through hole is located in the center of the light-emitting diode, and the electrode through hole is preferably circular or square, with a radius of 10-100μm, for example, a radius of 10-50 radii, preferably a radius of 35μm. When a pin is used to act on the center of the light-emitting diode, the pin acts on the area where the electrode through hole is located, and directly acts on the second insulating layer. Since the metal is removed from the electrode through hole, it avoids the second insulating layer 104 from being pulled and damaged when the pin acts on the metal electrode (the first electrode 11 or the second electrode 21), further avoiding the chip failure problem caused by the rupture of the insulating layer.

[0081] At the same time, the first connection electrode 112 and the second connection electrode 212 are almost entirely located above the light-emitting epitaxial layer 102, and the first connection electrode 112 and the first connection electrode 212 have a reflective metal layer, which can effectively reflect the light radiated from the active layer 1023. By opening a hole in the first connection electrode 112 or the second connection electrode 212, the area of ​​the metal electrode above the first insulating layer 103 sacrificed by the ejector action area can be minimized, thereby improving the brightness.

[0082] Furthermore, a blocking layer 24 and a transparent conductive layer 23 are provided between the second electrode 21 and the light-emitting epitaxial layer 102 (second conductive type semiconductor layer 1022), and the blocking layer 24 is sandwiched between the light-emitting epitaxial layer 102 and the transparent conductive layer 21. The second contact electrode 211 corresponds to the blocking layer 24 (also called CB, i.e., current block) up and down, that is, the projection of the second contact electrode on the blocking layer 24 is located inside the blocking layer 24; the blocking layer is used to block the current to prevent the current from crowding directly under the second electrode 21, so that the current is scattered; the transparent conductive layer 23 is used as a channel for the current to flow through. Through such a design, the current flows through the transparent conductive layer 23 through the entire surface of the second conductive type semiconductor layer 1022, avoiding current crowding, and ensuring that the current is expanded as much as possible on the surface of the second conductive type semiconductor layer 1022 to improve the light-emitting efficiency. As an example, the blocking layer 24 can be SiO2, Si3N4, SiON or a composite structure thereof. The transparent conductive layer 23 may include at least one of indium tin oxide (ITO), zinc-doped indium tin oxide (ZITO), zinc indium oxide (ZIO), gallium indium oxide (GIO), zinc tin oxide (ZTO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), and gallium-doped zinc oxide (GZO). In this embodiment, the transparent conductive layer 2340 is preferably an ITO (indium tin oxide semiconductor transparent conductive film) layer formed by evaporation or sputtering process.

[0083] Further, the first insulating layer 103 has a reflective function, which is used to reflect the light emitted by the active layer 1023 so that the light is emitted from the substrate surface. The first insulating layer 103 can be a DBR or ODR (Ag reflector) structure. As an example, the first insulating layer 103 includes at least one of SiO2, SiN, SiOxNy, TiO2, Si3N4, Al2O3, TiN, and AlN. In this embodiment, the DBR structure is taken as an example. DBR (distributed Bragg reflection) is also called a distributed Bragg reflector. It is a periodic structure composed of two materials with different refractive indices arranged alternately in an ABAB manner. For example, it can be an alternating arrangement of TiO2 and SiO2. When the first insulating layer 103 is a DBR layer, the thickness is preferably more than 1 micron. Similar to the first insulating layer 103, the second insulating layer 104 also has a reflective function and can be a DBR or ODR (Ag reflector) structure. In addition, the first insulating layer 103 and the second insulating layer 104 must also have good insulating properties to block different conductive materials in the light emitting diode, such as P metal and N metal.

[0084] Furthermore, the first pad 12 and the second pad 22 may include an adhesion layer, a reflective layer, a stress buffer layer, a eutectic layer and a surface layer from bottom to top, wherein the adhesion layer is preferably a chromium or titanium layer, which is used for the adhesion of the first pad 12 and the second pad 22 to the second insulating layer 104; the reflective layer is preferably an aluminum layer, and the stress buffer layer may be a repeated stack of titanium / aluminum / titanium / aluminum / titanium / aluminum. The eutectic layer may be a combination of a nickel layer and a platinum layer, or the more preferred eutectic layer is a nickel layer, which can ensure sufficient eutectic ability, but its stress is relatively large, so the aforementioned stress buffer layer is required. In addition, the nickel layer can play a barrier role when the pad is welded to the circuit board, preventing the welding material from damaging the underlying reflective layer and stress buffer layer during welding; the surface layer may be a tin layer or a gold-tin layer or a gold layer to prevent surface oxidation.

[0085] Embodiment 2

[0086] This embodiment also provides a flip-chip light emitting diode. Based on the structure of the first embodiment, this embodiment mainly improves the electrode arrangement. The specific structure of the light emitting diode includes:

[0087] See also Figure 4 Combined with Figure 3 , for the sake of easy understanding, the light-emitting diode is divided into regions. When looking down at the light-emitting diode from above, the light-emitting diode includes a first region 100 and a second region 200. The first region 100 includes a first outer region 1001 and a first inner region 1002. The first outer region 1001 surrounds the periphery of the second region 200. The second region 200 includes two second sub-regions 2001 arranged along a first direction and a central region 2002 connecting adjacent second sub-regions 2001. The first inner region 1002 is arranged on both sides of the central region 2002 along a second direction, and the first direction is perpendicular to the second direction. The first region 100 is used to form the first connecting electrode 112, and the second region 200 is used to form the second connecting electrode 212. The first connecting electrode 112 is arranged around the second connecting electrode 212.

[0088] See also Figure 6 , Figure 7 Combined with Figure 3, the first conductive type semiconductor layer 1021 of the first area 100 is formed with a first mesa 110, and the first contact electrode 111 includes a plurality of places of the first conductive type semiconductor layer located at the periphery of the light emitting epitaxial layer (i.e., the first outer partition 1001) and a plurality of places of the surface of the first conductive type semiconductor layer located in the hole inside the light emitting epitaxial layer (i.e., the first inner partition 1002). The first contact electrode 111 and the second contact electrode 211 are both dispersed in a plurality of places; the second contact electrode 211 is in a plurality of places, presenting a circular or elliptical shape, and is located on the second conductive type semiconductor layer. A plurality of the first contact electrodes 111 are located around the second contact electrode 211, and most of the first contact electrodes 111 are located at the edge.

[0089] The second connection electrode 212 is formed by connecting two relatively wide areas (i.e., two second sub-areas 2001) and a relatively narrow area in the middle (i.e., the central area 2002); the relatively narrow area is located at the center of the light-emitting diode and is formed with the electrode through hole 30 for the ejector action area. The first connection electrode 112 and the second connection electrode 212 are both symmetrically distributed along a central axis, corresponding to Figure 7 The left-right symmetrical distribution shown in is conducive to the uniformity of current dispersion.

[0090] The second sub-area 2001 is formed with a plurality of second contact electrodes 211 arranged in an array, and the second connection electrode 212 covers the second area 200 except the second branch 1122 to electrically connect the second contact electrodes 211. The second connection electrode 212 located in the central area 2002 is formed with the electrode through hole 30, and the electrode through hole 30 is preferably circular.

[0091] Further, see Figure 5 Combined with Figure 3 The blocking layer 24 is formed on the second conductive type semiconductor layer 1022 of the second area 200, and the second contact electrode 211 corresponds to the blocking layer 24 up and down, that is, the projection of the second contact electrode on the blocking layer 24 is located inside the blocking layer 24; a transparent conductive layer 23 is formed on the second conductive type semiconductor layer 1022 of the second area 200 and the blocking layer 24; the transparent conductive layer 23 is located between the second conductive type semiconductor layer 1022 and the second contact electrode 211.

[0092] Specifically, as a preferred solution, most of the first contact electrodes 111 are elliptical.

[0093] Specifically, as a preferred solution, the second contact electrodes 211 are all circular and evenly distributed so that the current can be evenly spread. Preferably, the light emitting diode is a square chip, and every four second contact electrodes 211 are combined to form a square pattern.

[0094] It should be understood that the first contact electrode 111 and the second contact electrode 211 do not contact each other, and the first connection electrode 112 and the second connection electrode 212 do not contact each other.

[0095] Further, see Figure 8 Combined with Figure 3 , at least 50% of the vertical projection area of ​​the first pad 12 and at least 50% of the vertical projection area of ​​the second pad 22 fall into two relatively wide areas (i.e., the second sub-area 2001) of the second connecting electrode 212 respectively. The first pad and the second pad also have symmetry, which ensures the stability of the pads when they are soldered to the circuit substrate of the application end, and avoids skewing due to uneven surface heights of the two pads. Naturally, the first pad 12 is electrically connected to the first connecting electrode 112, and the second pad 22 is electrically connected to the second connecting electrode 212.

[0096] Specifically, the steps of preparing the light emitting diode include:

[0097] First, the active layer 1023 and the second conductive type semiconductor layer 1022 located in the first area 100 are etched to form a first table 110 exposing the first conductive type semiconductor layer 1021, and then a plurality of the barrier layers 24 are formed on the second conductive type semiconductor layer 1022 in the second area 200. The barrier layers 24 are preferably circular and arranged in an array, such as Figure 4 As shown;

[0098] Next, a transparent conductive layer 23 is formed on the second conductive type semiconductor layer 1022 of the second region 200 and the barrier layer 24. Figure 5 As shown;

[0099] Next, a plurality of first contact electrodes 111 are formed on the first mesa 110 of the first region 100, and a second contact electrode 211 is formed on the transparent conductive layer 23. The second contact electrode 211 corresponds to the barrier layer 24 in the vertical direction. Figure 6 As shown;

[0100] Next, the first insulating layer 103 is formed, and a first connecting electrode 112 and a second connecting electrode 212 are formed on the first insulating layer 103. The first connecting electrode 112 and the second connecting electrode 212 are filled into the through holes of the first insulating layer 103 to form interconnections between the plurality of first contact electrodes 111 and the plurality of second contact electrodes 211, respectively. Figure 7 As shown;

[0101] Next, a second insulating layer 104 is formed, and a first pad 12 and a second pad 22 are formed on the second insulating layer 104. The first pad 12 and the second pad 22 are filled into the through hole of the second insulating layer 104 to form an electrical connection with the first connection electrode 112 and the second connection electrode 212, respectively. Figure 8 shown.

[0102] In this embodiment, multiple first contact electrodes 111 are located around the second contact electrode 211, and most of the first contact electrodes 111 are located at the edge, multiple second contact electrodes 211 are located in a relatively central area, and the first connection electrode 112 is arranged around the second connection electrode 212. The reasonable arrangement of the first electrode and the second electrode can achieve better current expansion, disperse the current diffusion distribution, make the light-emitting diode chip emit light evenly, and further improve the light-emitting brightness of the light-emitting diode chip.

[0103] It should be noted that the electrode design in this embodiment is only a preferred solution. The electrode design of the light emitting diode in the present invention is not limited to the structure in this embodiment, and other configurations are also possible.

[0104] In summary, the present invention provides a flip-chip light-emitting diode and a lighting device, wherein the first connecting electrode or the second connecting electrode of the light-emitting diode located on the first insulating layer has an electrode through hole, and the electrode through hole is filled with the second insulating layer. When a pin is used to act on the center of the light-emitting diode, the pin acts on the area where the electrode through hole is located, and directly acts on the second insulating layer. Since the metal is removed from the electrode through hole, the second insulating layer is prevented from being pulled and damaged when the pin acts on the metal electrode, and the chip failure problem caused by the rupture of the insulating layer is further avoided. At the same time, the present invention also makes further improvements to the electrode arrangement, so as to achieve better expansion of the current, disperse the current diffusion distribution, make the light-emitting diode chip emit light evenly, and further improve the brightness and reliability of the light-emitting diode chip.

[0105] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A flip-chip light emitting diode, characterized in that: The light emitting diode comprises: light emitting epitaxial layer; A first insulating layer, covering the light-emitting epitaxial layer and around the sidewalls, wherein the first insulating layer has a plurality of through holes; A first connection electrode and a second connection electrode having opposite electrical properties, which are located on the first insulating layer and are filled into the through holes of the first insulating layer to be electrically connected to the light-emitting epitaxial layer; a second insulating layer, wherein the second insulating layer covers the light-emitting epitaxial layer and around the sidewalls thereof, and covers the first connecting electrode, the second connecting electrode and the first insulating layer; Among them, the first connecting electrode or the second connecting electrode has an electrode through hole, the bottom of the electrode through hole is the first insulating layer, the second insulating layer also fills the electrode through hole and contacts the first insulating layer, and the electrode through hole is only filled with the second insulating layer; and looking down at the light-emitting diode from top to bottom, the electrode through hole is located in the center of the light-emitting diode.

2. The light emitting diode according to claim 1, characterized in that: The electrode through hole is circular, and its radius is 10-100 microns.

3. The light emitting diode according to claim 1, characterized in that: The thickness of the second insulating layer is 0.1-1.5 microns.

4. The light emitting diode according to claim 1, characterized in that: The thickness of the first insulating layer is greater than 2 micrometers.

5. The light emitting diode according to claim 1, characterized in that: Also includes: The first pad and the second pad are located on the second insulating layer and are filled into a plurality of through holes of the second insulating layer to electrically connect the first connection electrode and the second connection electrode respectively.

6. The light emitting diode according to claim 1, characterized in that: It also includes a first contact electrode and a second contact electrode; a plurality of the first contact electrodes and a plurality of the second contact electrodes are located under the first insulating layer, the first connecting electrode fills in a through hole of the first insulating layer to connect the plurality of the first contact electrodes, and the second connecting electrode fills in a through hole of the first insulating layer to connect the plurality of the second contact electrodes.

7. The light emitting diode according to claim 6, characterized in that: Looking down at the light emitting diode from above, the first connecting electrode is arranged around the second connecting electrode.

8. The light emitting diode according to claim 7, characterized in that: The second connection electrode is in the shape of two relatively wide regions and a relatively narrow region between the two relatively wide regions, and the relatively narrow region connects the two relatively wide regions.

9. The light emitting diode according to claim 7, characterized in that: The relatively narrow area of ​​the second connecting electrode is located at the center of the light emitting diode and is formed with the electrode through hole for the ejector action area.

10. The light emitting diode according to claim 7, characterized in that: The first connection electrodes and the second connection electrodes are both symmetrically distributed along a central axis.

11. The light emitting diode according to claim 8, characterized in that: It also includes a first solder pad and a second solder pad, which are located on the second insulating layer and fill a plurality of through holes in the second insulating layer to electrically connect the first connecting electrode and the second connecting electrode respectively; at least 50% of the vertical projection area of ​​the first solder pad falls into one relatively wide area of ​​the second connecting electrode, and at least 50% of the vertical projection area of ​​the second solder pad falls into another relatively wide area of ​​the second connecting electrode.

12. The light emitting diode according to claim 6, characterized in that: The light emitting epitaxial layer includes a first conductive type semiconductor layer, an active layer and a second conductive type semiconductor layer stacked in sequence.

13. The light emitting diode according to claim 12, characterized in that: The first contact electrode and the second contact electrode are both dispersed in multiple locations; the first contact electrode includes multiple locations on the first conductive type semiconductor layer located at the periphery of the light-emitting epitaxial layer and multiple locations on the surface of the first conductive type semiconductor layer located in the holes inside the light-emitting epitaxial layer; the second contact electrode is in multiple locations, located on the second conductive type semiconductor layer.

14. A lighting device, characterized in that: It comprises a light emitting diode as described in any one of claims 1 to 13.

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