LED electrode and chip

Abstract

The utility model discloses an LED electrode and a chip. The LED electrode comprises a first adhesion layer, a functional layer, a conductive layer, a spacing layer and a bonding wire layer, wherein the first adhesion layer is used for adhering to an epitaxial structure; the functional layer is used for protecting the first adhesion layer; the functional layer comprises a single-layer structure or a multi-layer structure, when the functional layer is of the multi-layer structure, a metal medium of the functional layer is at least two of Ti, Pt, Ni, W, W alloy and Al-Cu alloy, and the thickness of the functional layer is 1-5 microns; when the functional layer is of a single-layer structure, the metal medium of the functional layer is one of Ti or Ni metal films, and the thickness of the functional layer is # imgabs0 #. According to the utility model, the spacing layer is arranged between the conductive layer and the bonding wire layer to separate the conductive layer from the bonding wire layer, so that the problems of poor eutectic and too small thrust value between the bonding wire layer and the bonding wire under the bonding wire condition of normal pressure and within 200 DEG C are avoided, and the service life of the bonding wire layer is prolonged. And therefore, the practical application problems of off-line, poor contact and the like are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor devices, in particular to an LED electrode and a chip. Background Art

[0002] The traditional LED chip structure includes epitaxy, current blocking layer (CBL), transparent conductive layer (TCL), electrode (PAD), protective layer (PSV) and other structures. Among them, the electrode structure includes adhesion layer, reflective layer, protective layer and welding wire layer in sequence, and the metal used in the traditional welding wire layer is all precious metal Au.

[0003] At present, the use of precious metal Au in the conductive layer of the electrode structure has the following disadvantages: the price of metal Au is high, and the absorption rate of blue light is high, which reduces the luminous efficiency of white light LEDs. At the same time, in order to avoid the phenomenon of gold and aluminum dissolving in the LED chip during the application process, metal Cu is used to replace the precious metal Au.

[0004] However, in the field of LED applications, packaging wires are mostly made of Ag alloy wires, Au wires or Cu-Au wires to ensure the reliability of LED chips. In the current structure, the wire layer and the conductive layer are generally in direct contact, so under the existing normal pressure and 200°C wire bonding conditions, Cu-Au is prone to practical application problems such as wire debonding and poor contact. Utility Model Content

[0005] Based on this, the purpose of the utility model is to provide an LED electrode and chip, aiming to solve the practical application problems such as Cu-Au being easily debonded and having poor contact, because there is no interlayer between the welding wire layer and the conductive layer under the existing normal pressure and welding conditions within 200°C.

[0006] To achieve the above object, the utility model is implemented through the following technical solution: an LED electrode, the LED electrode comprising:

[0007] A first adhesive layer for adhering to the epitaxial structure, a functional layer for protecting the first adhesive layer, a conductive layer for conducting electricity, a spacer layer for blocking, and a wire bonding layer for packaging are sequentially stacked on the LED chip;

[0008] Wherein, the functional layer includes a single-layer structure or a multi-layer structure. When the functional layer is a multi-layer structure, its metal medium is at least two of Ti, Pt, Ni, W, W alloy, and Al-Cu alloy, and its thickness is 1 μm to 5 μm;

[0009] When the functional layer is a single-layer structure, the metal medium is a Ti or Ni metal film, and the thickness is

[0010] In summary, according to an LED electrode proposed by the utility model, a spacer layer is provided between the conductive layer and the welding wire layer to separate the two, thereby preventing Cu from diffusing into Au. Under the conditions of normal pressure and welding wire within 200°C, problems such as poor eutectic and too small thrust value occur between the welding wire layer and the welding wire, which leads to practical application problems such as decoupling and poor contact. Specifically, the LED electrode includes a substrate, a surface of which is provided with an epitaxial structure and an electrode provided on the epitaxial structure, and the electrode includes a first adhesion layer, a functional layer, a conductive layer, a spacer layer and a welding wire layer sequentially stacked on the transparent conductive layer. The functional layer is used to protect the first adhesion layer from contacting the welding wire layer to avoid aging failure. The metal medium used to form the welding wire layer is Au, and the metal medium used to form the conductive layer is Cu. The spacer layer is provided between the welding wire layer and the conductive layer to isolate Cu and Au to avoid mutual dissolution of Cu and Au, thereby causing the welding wire layer to be decoupled. Affecting the wire bonding in packaging applications.

[0011] Furthermore, the first adhesion layer includes a Cr film, a Ti film or a Ni film. When the first adhesion layer is a Cr film, its thickness is When the adhesion layer is a Ti or Ni film, its thickness is

[0012] Furthermore, the thickness of the welding wire layer is

[0013] Furthermore, the metal medium of the spacer layer is Ti or Pt, and the metal thickness of the spacer layer is

[0014]

[0015] Furthermore, the conductive layer has a thickness of 0.5 μm to 3.5 μm.

[0016] The utility model also provides an LED chip, which includes an epitaxial structure, which includes a patterned sapphire substrate and an N-type semiconductor layer stacked in sequence on the substrate, a multi-quantum well light-emitting area and a P-type semiconductor layer stacked in sequence on part of the N-type semiconductor layer, a current blocking layer and a transparent conductive layer arranged on the P-type semiconductor layer, an N electrode arranged above the N-type semiconductor and a P electrode arranged above the transparent conductive layer, and the P electrode and the N electrode both include the above-mentioned LED electrode.

[0017] Furthermore, the current blocking layer includes one or more transparent insulating materials of SiO2, Al2O3, TiO2 or Ti3O5.

[0018] Furthermore, the transparent conductive layer includes ITO or IZO transparent conductive material.

[0019] Furthermore, the N-type semiconductor layer and the P-type semiconductor layer are covered with a second protective layer, and the metal medium of the second protective layer includes one or more insulating materials such as SiO2, Al2O3, TiO2, Ti3O5 or SiN.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0022] Figure 1 This is a schematic diagram of the structure of an LED electrode provided in one embodiment of the utility model;

[0023] Figure 2 Schematic diagram of the electrode structure.

[0024] Component symbol description:

[0025] Substrate 1, patterned sapphire substrate 2, N-type semiconductor layer 3, multi-quantum well light-emitting area 4, P-type semiconductor layer 5, current blocking layer 6, transparent conductive layer 7, electrode 8, first adhesion layer 8A, functional layer 8B, conductive layer 8C, spacer layer 8D, welding wire layer 8E, second protective layer 9. DETAILED DESCRIPTION

[0026] In order to make the purpose, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. Several embodiments of the utility model are given in the accompanying drawings. However, the utility model can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the utility model more thorough and comprehensive.

[0027] It should be noted that when an element is referred to as being "fixed on" another element, it may be directly on the other element or there may also be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right", "upper", "lower" and similar expressions used herein are for illustrative purposes only and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model.

[0028] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0029] See also Figure 1-Figure 2 , which is a schematic diagram of the structure of an LED electrode 8 provided in one embodiment of the utility model, comprises a substrate 1, an epitaxial structure arranged on the substrate 1, and an electrode 8 arranged on the epitaxial structure, wherein:

[0030] The epitaxial structure includes a patterned sapphire substrate 2 and an N-type semiconductor layer 3 stacked in sequence on a substrate 1, a multi-quantum well light-emitting region 4 and a P-type semiconductor layer 5 stacked in sequence on a portion of the N-type semiconductor layer 3, and a current blocking layer 6 and a transparent conductive layer 7 arranged on the P-type semiconductor layer 5.

[0031] The substrate 1 is provided with a first serrated interlocking portion on the side facing the N-type semiconductor layer 3, and correspondingly, the N-type semiconductor layer 3 is provided with a second serrated interlocking portion used in conjunction with the first interlocking portion on the side facing the substrate 1. The patterned sapphire substrate 2 is provided between the substrate 1 and the N-type semiconductor layer 3. In order to enhance the degree of interlocking, the patterned sapphire substrate 2 is also provided in a serrated shape to prevent the substrate 1, the patterned sapphire substrate 2 and the N-type semiconductor layer 3 from moving relative to each other. The multi-quantum well light-emitting region 4 is provided on a portion of the N-type semiconductor layer 3 to leave space for installing the electrode 8, and the P-type semiconductor layer 5 is stacked on the multi-quantum well light-emitting region 4.

[0032] Further, the current blocking layer 6 is etched on the exposed P-type semiconductor shape, which is arranged at the center of the P-type semiconductor shape, and can be composed of one or more transparent insulating materials such as SiO2, Al2O3, TiO2 (or Ti3O5), and the selection of transparent materials avoids blocking the pattern of the multi-quantum well light-emitting area 4. The transparent conductive layer 7 is arranged on the P-type semiconductor layer 5, which is stacked on the P-type semiconductor layer 5 and covers the current blocking layer 6. Similarly, the transparent conductive layer 7 can be a transparent conductive material such as ITO, IZO, etc., to avoid blocking the pattern of the multi-quantum well light-emitting area 4.

[0033] Furthermore, the electrode 8 includes an N electrode 8 disposed above the N-type semiconductor and a P electrode 8 disposed above the transparent conductive layer 7, and the P electrode 8 and the N electrode 8 have the same structure. The electrode 8 includes a first adhesion layer 8A, a functional layer 8B, a conductive layer 8C, a spacer layer 8D and a welding wire layer 8E stacked in sequence on the epitaxial structure. In this embodiment, the first adhesion layer 8A is obtained by compounding an adhesion layer and a reflective layer. The adhesion layer can be a metal film such as Cr, Ti, Ni, etc. When the first adhesion layer 8A is a Cr film, its thickness is When the adhesion layer is a Ti or Ni film, its thickness is The metal medium of the reflective layer can be one or more highly reflective metals such as Al, Ag or Mg.

[0034] Preferably, in this embodiment, the functional layer 8B is an optional layer. When the functional layer 8B is a protective laminate, the functional layer is a multilayer structure, and its metal medium can be at least two of Ti, Pt, Ni, W, W alloy, and Al-Cu alloy, and its thickness is 1 μm to 5 μm. The traditional protective layer is generally Ti / Pt / Ti / Pt / Ti / Pt or Ni / Pt / Ni / Pt / Ni / Pt laminate, which can effectively protect the first adhesion layer 8A.

[0035] When the functional layer 8B is the second adhesion layer, it is a single-layer structure, and its metal medium can be a Ti or Ni metal film with a thickness of Only one layer of Ti or Ni is left, and Pt is omitted to save costs. At the same time, when making the LED electrode 8, there is no need to frequently switch the target source to improve production capacity. The protective layer in the traditional structure is abandoned, the electrode 8 structure can be simplified, and costs can be saved.

[0036] It should be emphasized that the metal medium used to form the bonding wire layer 8E is Au, and the thickness of the bonding wire layer 8E is The metal medium used to form the conductive layer 8C is Cu, and the thickness of the conductive layer 8C is 0.5 μm to 3.5 μm; the spacer layer 8D is provided between the bonding wire layer 8E and the conductive layer 8C to isolate Cu and Au, and the metal medium of the spacer layer 8D can be Ti or Pt, and the metal thickness of the spacer layer 8D is By setting a spacer layer 8D between the conductive layer 8C and the welding wire layer 8E to separate the two, it is avoided that under the welding conditions of normal pressure and within 200°C, there will be problems such as poor eutectic and too small thrust value between the conductive layer 8C and the welding wire layer 8E, which will lead to practical application problems such as derailment and poor contact.

[0037] In addition, the N-type semiconductor layer 3 and the P-type semiconductor layer 5 are also covered with a second protective layer 9, and the metal medium of the second protective layer 9 can be one or more insulating materials such as SiO2, Al2O3, TiO2 (or Ti3O5), SiN, etc., to protect the LED electrode chip.

[0038] In summary, according to an LED electrode proposed by the utility model, a spacer layer is provided between the conductive layer and the welding wire layer to separate the two, thereby preventing Cu from diffusing into Au. Under the conditions of normal pressure and welding wire within 200°C, problems such as poor eutectic and too small thrust value occur between the welding wire layer and the welding wire, which leads to practical application problems such as decoupling and poor contact. Specifically, the LED electrode includes a substrate, a surface of which is provided with an epitaxial structure and an electrode provided on the epitaxial structure, and the electrode includes a first adhesion layer, a functional layer, a conductive layer, a spacer layer and a welding wire layer sequentially stacked on the transparent conductive layer. The functional layer is used to protect the first adhesion layer from contacting the welding wire layer to avoid aging failure. The metal medium used to form the welding wire layer is Au, and the metal medium used to form the conductive layer is Cu. The spacer layer is provided between the welding wire layer and the conductive layer to isolate Cu and Au to avoid mutual dissolution of Cu and Au, thereby causing the welding wire layer to be decoupled. Affecting the wire bonding in packaging applications.

[0039] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0040] The above-mentioned embodiments only express several implementation methods of the utility model, and the descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. An LED electrode, characterized in that: The LED electrode comprises: A first adhesive layer for adhering to the epitaxial structure, a functional layer for protecting the first adhesive layer, a conductive layer for conducting electricity, a spacer layer for blocking, and a wire bonding layer for packaging are sequentially stacked on the LED chip; Wherein, the functional layer comprises a single-layer structure or a multi-layer structure. When the functional layer is a multi-layer structure, its thickness is 1 μm to 5 μm; When the functional layer is a single-layer structure, the metal medium is a Ti or Ni metal film, and the thickness is 2. The LED electrode according to claim 1, characterized in that: The first adhesion layer includes a Cr film, a Ti film or a Ni film. When the first adhesion layer is a Cr film, its thickness is When the adhesion layer is a Ti or Ni film, its thickness is 3. The LED electrode according to claim 1, characterized in that: The thickness of the bonding wire layer is 4. The LED electrode according to claim 1, characterized in that: The metal medium of the spacer layer is Ti or Pt, and the metal thickness of the spacer layer is 5. The LED electrode according to claim 1, characterized in that: The conductive layer has a thickness of 0.5 μm to 3.5 μm.

6. An LED chip, characterized in that: The LED chip includes an epitaxial structure, which includes a substrate, a patterned sapphire substrate and an N-type semiconductor layer stacked in sequence on the substrate, a multi-quantum well light-emitting region and a P-type semiconductor layer stacked in sequence on part of the N-type semiconductor layer, a current blocking layer and a transparent conductive layer arranged on the P-type semiconductor layer, an N-electrode arranged above the N-type semiconductor and a P-electrode arranged above the transparent conductive layer, and the P-electrode and the N-electrode both include the LED electrode as described in any one of claims 1 to 5.

7. The LED chip according to claim 6, characterized in that: The current blocking layer includes any one of SiO2, Al2O3, TiO2 or Ti3O5 transparent insulating materials.

8. The LED chip according to claim 7, characterized in that: The transparent conductive layer includes ITO or IZO transparent conductive material.

9. The LED chip according to claim 7, characterized in that: The N-type semiconductor layer and the P-type semiconductor layer are also covered with a second protective layer, and the metal medium of the second protective layer includes any one of SiO2, Al2O3, TiO2, Ti3O5 or SiN insulating materials.

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