阅读说明：本技术 一种电极共面led基板及其制备方法 (Electrode coplanar LED substrate and preparation method thereof ) 是由 李国强 于 2021-06-11 设计创作，主要内容包括：本发明提供一种电极共面LED基板及其制备方法,该电极共面LED基板包括：绝缘衬底；贯穿所述绝缘衬底的P型引出电极和N型引出电极；以及位于所述绝缘衬底一侧的导电粘结层。制备方法包括以下步骤：在所述绝缘衬底上制备贯穿所述绝缘衬底的电极通道；在所述电极通道内形成P型引出电极一和N型引出电极一；在所述绝缘衬底一侧形成粘结层。本发明可实现LED芯片电极制备于同侧,避免了以往制作电极而损失一部分发光面积,有效提升了芯片的光输出功率。(The invention provides an electrode coplanar LED substrate and a preparation method thereof, wherein the electrode coplanar LED substrate comprises: an insulating substrate; the P-type extraction electrode and the N-type extraction electrode penetrate through the insulating substrate; and a conductive adhesive layer on one side of the insulating substrate. The preparation method comprises the following steps: preparing an electrode channel penetrating through the insulating substrate on the insulating substrate; forming a P-type extraction electrode I and an N-type extraction electrode I in the electrode channel; and forming an adhesive layer on one side of the insulating substrate. The invention can realize that the electrodes of the LED chip are prepared on the same side, thereby avoiding the loss of part of the light-emitting area caused by the previous electrode manufacturing and effectively improving the light output power of the chip.)

1. An electrode coplanar LED substrate, comprising: the method comprises the following steps: an insulating substrate; the P-type extraction electrode and the N-type extraction electrode penetrate through the insulating substrate; and a conductive adhesive layer on one side of the insulating substrate.

2. The electrode coplanar LED substrate as set forth in claim 1, wherein: the thickness of the insulating substrate is 50-500 mu m.

3. The electrode coplanar LED substrate as set forth in claim 1, wherein: the P-type leading-out electrode and the N-type leading-out electrode are made of at least one of Al, Cu, Ti, Cr, Ag, Au and Pt or ITO conductive non-metallic materials.

4. The electrode coplanar LED substrate as set forth in claim 1 or 3, wherein: and a metal seed layer is arranged on the inner surface of the through hole which is used for penetrating through the P-type extraction electrode and the N-type extraction electrode on the insulating substrate.

5. The electrode coplanar LED substrate as set forth in claim 4, wherein: the metal seed layer is Au or Cu.

6. The electrode coplanar LED substrate as set forth in claim 1, wherein: the thickness of the conductive bonding layer is 500 nm-10 mu m.

7. The electrode coplanar LED substrate as set forth in claim 1 or 6, wherein: the conductive bonding layer is made of at least one of Ni, Au, Sn and Ti.

8. The method for preparing an electrode coplanar LED substrate as claimed in any one of claims 1 to 7, wherein the method comprises the following steps: the method comprises the following steps:

preparing an electrode channel penetrating through the insulating substrate on the insulating substrate;

forming a P-type extraction electrode and an N-type extraction electrode in the electrode channel;

and forming a conductive bonding layer on one side of the insulating substrate.

9. The method for preparing an electrode coplanar LED substrate as claimed in claim 8, wherein: the preparation method further comprises the following steps: and before the first P-type extraction electrode and the first N-type extraction electrode are formed in the electrode channel, a plating metal seed layer is formed on the inner surface of the first P-type extraction electrode and the first N-type extraction electrode.

Technical Field

The invention relates to the technical field of LED manufacturing, in particular to an electrode coplanar LED substrate and a preparation method thereof.

Background

With the ever-expanding market share of LED lighting, the requirements for lighting performance such as lighting efficiency of LEDs are higher and higher, and the demand for large-power and even ultra-large-size LED chips in the market becomes more and more mainstream from the common household lighting lamps to the street lamps and headlight systems requiring higher power. The first problem that is faced first by super-power, super-sized LEDs is current crowding. The embedded electrode structure LED chip has many advantages compared with the chip of the traditional structure: the current expansibility is better, the conductivity is better, the heat dispersion is better and the light extraction rate is higher.

The prior art chip with the embedded electrode structure still has some problems, because a low-resistance silicon substrate with an extremely simple structure is adopted, the P type electrode and the N type electrode can not be arranged on the same substrate, the P type electrode can only be arranged on the upper surface of the chip, namely, the P type electrode and the N type electrode are respectively arranged on the bottom surface of the top of the chip, and the P type electrode arranged on the top ensures that the chip can sacrifice a light emitting area with a certain area and the P type electrode can also shield part of light, therefore, the light output efficiency of the LED can be improved, and how to improve the position of the P type electrode structure on the premise of not losing the light emitting area of the active area is a technical difficulty in designing a more reasonable embedded LED chip substrate.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide an electrode coplanar LED substrate and a preparation method thereof. The manufacturing of the electrode coplanar LED substrate is a new idea, firstly, deep space etching is carried out on an insulating substrate, then, a conductive electrode penetrating through the substrate is prepared through a sputtering electroplating method, and then, a bonding layer is prepared on one side of the substrate, so that the preparation of the electrode coplanar substrate is realized. The preparation of the electrode coplanar LED chip is to adopt a bonding process to align and bond the chip with two electrodes positioned on the same side and the electrode coplanar substrate, so that the preparation of the electrode coplanar LED chip is realized, the phenomenon that the luminous area of a part of the chip is lost due to the manufacture of the electrode with the traditional structure is avoided, and the light output power of the chip is effectively improved. The technical scheme of the invention is as follows:

in a first aspect, the present invention provides an electrode coplanar LED substrate comprising: an insulating substrate; the P-type extraction electrode and the N-type extraction electrode penetrate through the insulating substrate; and a conductive adhesive layer on one side of the insulating substrate.

Further, the thickness of the insulating substrate is 50-500 mu m. The insulating substrate can be made of insulating easily-processed materials such as a high-resistance Si substrate, a sapphire substrate and an organic high polymer material.

Furthermore, the P-type extraction electrode and the N-type extraction electrode are made of at least one of Al, Cu, Ti, Cr, Ag, Au and Pt or ITO conductive non-metallic materials.

Optionally, a metal seed layer is disposed on the insulating substrate and on an inner surface of the through hole penetrating through the P-type extraction electrode and the N-type extraction electrode.

Preferably, the metal seed layer is Au or Cu.

Further, the thickness of the conductive bonding layer is 500 nm-10 μm.

Preferably, the conductive adhesive layer is made of at least one of Ni, Au, Sn, and Ti.

In a second aspect, the invention provides a method for preparing the electrode coplanar LED substrate, comprising the following steps:

preparing an electrode channel penetrating through the insulating substrate on the insulating substrate;

forming a P-type extraction electrode and an N-type extraction electrode in the electrode channel;

and forming an adhesive layer on one side of the insulating substrate.

Further, the preparation method further comprises the following steps: and before the first P-type extraction electrode and the first N-type extraction electrode are formed in the electrode channel, a plating metal seed layer is formed on the inner surface of the first P-type extraction electrode and the first N-type extraction electrode.

Preferably, the electroplated metal seed layer is gold or copper.

Compared with the prior art, the invention has the following advantages:

the electrode coplanar LED substrate provided by the invention has the advantages that the electrode of the LED chip can be prepared on the same side, the loss of part of the light emitting area caused by the conventional electrode preparation is avoided, and the light output power of the chip is effectively improved, and the insulating substrate is adopted, so that the electrode insulating isolation layer does not need to be prepared in a deep hole to independently open the P-type electrode and the N-type electrode, and the preparation of the insulating isolation layer on the inner wall of the aperture with the depth of only 2-10 microns and 50-500 microns is a very complicated process in the prior art, so that the electrode coplanar LED substrate preparation technology can greatly improve the light emitting efficiency of the conventional LED chip.

Drawings

Fig. 1 is a cross-sectional view of an electrode coplanar LED substrate of the present invention.

Fig. 2 is a cross-sectional view of an LED chip (with a base) employing an electrode coplanar LED substrate of the present invention.

Fig. 3 is a cross-sectional view of the alignment key of fig. 1 and 2 with the substrate peeled away.

Fig. 4 is a cross-sectional view of a complete electrode coplanar LED chip employing the electrode coplanar LED substrate of the present invention.

Fig. 5 is a top view of a complete electrode coplanar LED chip employing the electrode coplanar LED substrate of the present invention.

Fig. 6 is a schematic structural diagram of a conventional LED chip.

In FIGS. 1-6, 110-insulating substrate; 111-a conductive adhesive layer; 112-P type extraction electrode; 113-N type extraction electrodes; 101-a growth substrate; a 102-N type GaN layer; 103-InGaN/GaN multi-quantum well layer; 104-P type GaN layer; 105-P contact mirror metal and protective layer; 106-an insulating layer; 107-a first bonding layer; 108-a columnar N electrode; 109-columnar P-electrode, 11, conventional LED chip substrate; 12, an N-type buffer layer of the traditional LED chip; 13, a conventional LED chip N-type layer; 14, a conventional LED chip negative electrode; 15, traditional LED chip active area quantum well; 16, conventional LED chip P-type layer; 17, a conventional LED chip transparent conductive layer; and 18, a conventional LED chip positive electrode.

Detailed Description

In the description of the present invention, it is to be noted that those whose specific conditions are not specified in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturers. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The present invention will now be described in further detail with reference to the following figures and specific examples, which are intended to be illustrative, but not limiting, of the invention.

Example 1

Referring to fig. 1, the present embodiment provides an electrode coplanar LED substrate, including: an insulating substrate 110; a P-type extraction electrode 112 and an N-type extraction electrode 113 penetrating the insulating substrate 110; and a conductive adhesive layer 111 on one side of the insulating substrate 110. In this embodiment, the insulating substrate 110 is a high-resistance Si substrate with a thickness of 400 μm. The thickness of the conductive adhesive layer 111 is 8 μm, and the material is Au. The P-type extraction electrode 112 and the N-type extraction electrode 113 are made of Cu, a metal seed layer with a thickness of 2000A is arranged on the surface of the P-type extraction electrode and the N-type extraction electrode, and the metal seed layer is made of Au. The preparation method of the electrode coplanar LED substrate comprises the following steps:

(1) taking a high-resistance silicon wafer substrate 110 with the thickness of 400 microns, and etching a plurality of deep holes with the depth of 120 microns by adopting a deep silicon etching process;

(2) then, sputtering a layer of gold with the thickness of 2000A to the deep holes by adopting a sputtering method;

(3) carrying out an electroplating copper process in the hole, and respectively electroplating a P-type electrode Pad112 and an N-type electrode Pad 113;

(4) then preparing a gold bonding layer 111 with the thickness of 8 microns in a patterning mode through an electron beam evaporation and stripping process;

(5) mechanically thinning the back surface of the high-resistance silicon substrate 110 until the deep silicon etching hole is exposed;

(6) and sputtering and electroplating the through hole exposed from the thinning surface of the high-resistance silicon substrate 110 again to ensure normal metal connection in the hole, and then preparing the electrode Pad of the thinning surface through an electron beam evaporation and patterning process to finish the preparation of the coplanar electrode LED substrate.

In addition, the insulating substrate can also be made of insulating easily-processed materials such as a sapphire substrate and an organic polymer material, the thickness of the insulating substrate is only 50-500 mu m, the thickness of the substrate is suitable for being beneficial to the conductivity of the finally formed LED chip, if the thickness of the substrate is lower than 50 mu m, the substrate is too thin and is not beneficial to the electroplating formation of a P-type electrode and an N-type electrode in the later period, and if the thickness of the substrate is too high, the difficulty of a deep silicon etching process is increased. The P-type extraction electrode and the N-type extraction electrode can also be made of at least one of Al, Ti, Cr, Ag, Au and Pt or ITO conductive non-metallic materials. The thickness of the conductive bonding layer is 500 nm-10 μm, and the material can also be Ni, Sn or Ti.

Example 2

Referring to fig. 2-5, the present embodiment provides an electrode coplanar LED chip, including the electrode coplanar LED substrate of the structure described in embodiment 1 and the LED chip of the structure shown in fig. 2. The LED chip structure is shown in fig. 2, and comprises, from top to bottom, a first bonding layer 107, a columnar P electrode 109, a columnar N electrode 108, an insulating layer 106, a P contact mirror metal and protective layer 105, a P-type GaN layer 104, an InGaN/GaN multi-quantum well layer 103, an N-type GaN layer 102, and a growth substrate 101. The embedded columnar N electrode 108 radially penetrates through the insulating layer 106, the P-type GaN layer 104 and the InGaN/GaN multi-quantum well layer 103 from top to bottom, and finally penetrates into the N-type GaN layer 102 to form ohmic contact with the N-type GaN layer; the insulating layer 106 extends into the hole diameter to form insulating protection on the inner wall of the columnar N electrode 108; the top of the pillar-shaped P electrode 109 penetrates the insulating layer 106 to be electrically connected to the P contact mirror metal and the passivation layer 105. The LED chip is aligned and bonded with the substrate of embodiment 1 by a bonding technique, the columnar P electrode 109 is correspondingly bonded with the P-type extraction electrode 112 on the substrate, and the first bonding layer 107 is bonded with the conductive bonding layer 111 on the substrate, so that the electrical connection between the LED chip and the substrate is realized, and a brand new electrode coplanar LED chip is obtained. The performance parameters of the electrode coplanar LED chip of the present embodiment are shown in Table 1.

Table 1 electrode coplanar LED chip performance parameters for example 2

Comparative example 1

This comparative example provides a detailed description of a conventional LED chip, and fig. 6 is a schematic structural diagram of a conventional LED chip in which, as shown in fig. 6, an N-type buffer layer 12, an N-type layer 13, an active region quantum well 15, a P-type layer 16, a transparent conductive layer 17, a positive electrode 18, and a negative electrode 14 are provided on a substrate 11. The general process flow of the conventional LED chip is as follows: manufacturing a substrate, and performing structural design, buffer layer growth, N-type GaN layer growth, multi-quantum well luminescent layer growth, P-type GaN layer growth, annealing, detection (optical fluorescence and X-ray), structural design, mask processing, photoetching, ion etching, N-type electrodes (film plating, annealing and etching), P-type electrodes (film plating, annealing and etching), scribing, chip sorting, grading and the like. Since the conventional LED chip production process has been developed quite well, only an example of the general process flow is illustrated here, and it is well known to those skilled in the art that some details of the process may be changed during the specific production. The performance of the LED chip of the structure reaches the limit at present, and the performance of the LED chip prepared by the substrate is shown in a comparison table 1.

In summary, the electrode coplanar LED substrate provided by the present invention not only can realize that the electrodes of the LED chip are prepared on the same side, thereby avoiding a part of the light emitting area loss caused by the previous electrode preparation, and effectively improving the light output power of the chip, but also can prepare the insulating isolation layer of the electrode in the deep hole without preparing the insulating isolation layer of the electrode in the deep hole to make the P-type electrode and the N-type electrode independently open, and the preparation of the insulating isolation layer on the inner wall of the aperture with the depth of only 2-10 micrometers and the depth of 50-500 micrometers is a very complicated process in the previous art, so the preparation technology of the electrode coplanar LED substrate and the LED chip greatly simplifies the process difficulty, and improves the productivity.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.