CN207116432U - A kind of high voltage LED chip structure of CSP encapsulation - Google Patents

Abstract

The utility model discloses a CSP-packaged high-voltage LED chip structure, which comprises a flip-chip high-voltage LED chip, a fluorescent adhesive layer, and a packaging substrate. The flip-chip high-voltage LED chip is welded on the packaging substrate, and each high-voltage chip includes a plurality of sub-chips. , each sub-chip is separated by an isolation deep trench, and each sub-chip includes an n-type GaN, an active layer, a p-type GaN layer, a current diffusion layer, and an n-electrode and a p-electrode on the p-type GaN mesa, wherein The n-electrode is connected to the n-type GaN slope through the metal conductive layer on the side wall of the deep trench. The metal conductive layer is separated from the sub-chip by an insulating layer, and the n-electrode and p-electrode of each sub-chip are connected to the substrate electrode pad and interconnection respectively. wire bonding. The utility model has the advantages of small CSP packaging volume and low requirement for high-voltage chip power supply, can further increase the reliability of the electrical connection between the sub-chips of the high-voltage chip, and increase the area of the light-emitting layer of the chip under the same chip area.

Description

A CSP packaged high voltage LED chip structure

technical field

The invention relates to a chip structure of a high-voltage LED chip, in particular to a CSP-packaged high-voltage LED chip, which belongs to the field of semiconductor LED chip manufacturing and packaging.

Background technique

Semiconductor lighting light-emitting diode (LED) has many advantages such as high luminous efficiency, long life, environmental protection, and energy saving. It is known as a revolutionary technology in the new solid-state light source era in the 21st century, and is called the fourth-generation green light source.

CSP, that is, chip-scale packaging device, refers to controlling the package volume and flip chip volume to be the same or the package volume is not greater than 20% of the flip chip volume. In the LED field, CSP packaging is small in size and high in flexibility. Its application The scope is getting wider and wider. In addition, with the in-depth development of LED in the field of lighting, traditional low-voltage LEDs are increasingly exposed to inherent disadvantages, including short life of the driving power supply, low conversion efficiency, poor heat dissipation of low-voltage LEDs, and inability to work under high currents. In order to solve the above problems, high-voltage LED chips have been born in recent years. This high-voltage LED chip integrates multiple sub-chips in series on the same chip. These sub-chips are directly completed during the chip manufacturing process and have low power requirements. , high light efficiency and other advantages; the flip-chip high-voltage LED chip emits light from the substrate sapphire, and the packaging process uses the eutectic welding method to align and weld the electrodes on the front of the chip and the electrode pads on the substrate without using gold. The electrodes are connected by wires, which increases the stability of the package. In addition, the heat generated by the high-voltage LED light-emitting layer of the flip-chip structure is directly transmitted to the substrate, which has a better heat dissipation effect. Therefore, the high-voltage chip packaged by CSP not only reduces the volume of the package, but also has the advantages of high-voltage LED chips compared with traditional low-voltage chips.

In the Chinese Invention Patent Application Publication No. CN 105633240, a CSP packaged chip structure and manufacturing method are disclosed. The loss of light-emitting area is reduced by using n-type GaN slope sidewalls to form n-electrodes, but it only produces common low-voltage CSP packaged chips. For LED chips, the manufacturing process involves two slope-forming processes.

In the Chinese invention patent application publication number CN 103855149, a flip-chip high-voltage light-emitting diode and its manufacturing method are disclosed. The interconnection between the sub-chips is completed on the flip-chip substrate, which solves the problem caused by the interconnection line crawling through the deep trench. The problem of poor reliability, but the metal conductive layer is made on the side of the sub-chip in the vertical structure, it is easy to form a metal film with uneven thickness, and it is easy to cause an open circuit when high current passes.

Contents of the invention

The purpose of the present invention is to provide a CSP-packaged high-voltage LED chip structure and manufacturing method to solve the inherent disadvantages exposed by traditional low-voltage LEDs in CSP packages in the prior art, including short life of the driving power supply, low conversion efficiency, and heat dissipation. At the same time, it improves the reliability of the electrical interconnection between traditional flip-chip high-voltage LED sub-chips, and maximizes the area of the light-emitting layer under the same chip area.

In order to achieve the above object, the present invention adopts the following technical solutions: a CSP packaged high-voltage LED chip and its manufacturing method, including a flip-chip high-voltage LED chip, fluorescent glue, and a packaging substrate. The flip-chip high-voltage LED chip is welded on the packaging substrate. Each high-voltage chip includes a plurality of sub-chips, each sub-chip is separated by an isolation deep trench, and each sub-chip includes an n-type GaN, an active layer, a p-type GaN layer, a current spreading layer, and an n-electrode and a p-electrode, The n-electrode is connected to the n-type GaN slope through the metal conductive layer on the side wall of the deep trench, and the metal conductive layer is isolated from the sub-chip by an insulating layer covered on the shoe slope of the isolation deep trench. The n-electrode and the p The electrodes are respectively welded to the electrode pads of the substrate and the interconnection wires, and the fluorescent adhesive layer is located on the upper side of the flip chip.

Further, the metal conductive layer, the n-electrode, and the p-electrode are all made of Ag, Ni, Al and other metals with good conductivity and reflective properties, which can be a single-layer metal structure, or a multi-layer metal structure or an alloy layer composed of them;

Further, the current spreading layer can be an ITO film, or a metal film or other conductive films;

Further, the insulating layer may be composed of silicon nitride, silicon oxide, or aluminum nitride, or may be a combination of these materials or a DBR structure;

Further, both the n-electrode and the p-electrode are located on the p-type GaN mesa, they are electrically isolated, and the n-electrode and the current spreading layer are isolated by an insulating layer;

Further, the packaging substrate is provided with electrical interconnection lines and electrode pads between the sub-chips;

Further, after the electrodes of the flip-chip high-voltage LED chip are bonded to the electrode pads of the packaging substrate and the interconnection wires, the substrate is lifted off by laser, and a phosphor layer and a protective adhesive layer are sprayed on the n-type GaN;

Further, the package substrate is made of AlN, Si or metal material, and the substrate material is electrically isolated from the electrode pads and interconnection lines of the substrate by an insulating layer.

Description of drawings

Fig. 1 is the structural representation of the high-voltage LED chip of CSP package of the present invention;

Fig. 2 is the fabrication flowchart of the high-voltage LED chip of CSP package in one embodiment of the present invention;

3 is a perspective view of a high-voltage LED chip before packaging in an embodiment of the present invention;

4-10 are structural schematic diagrams of each step in the manufacturing process of the CSP-packaged high-voltage LED chip of the present invention;

Detailed ways

In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be described in more detail below with reference to the accompanying drawings. All the features, methods, or steps disclosed in this specification can be combined in any way, except for mutually exclusive features or steps. Unless stated otherwise, any feature disclosed in this specification may be replaced by other equivalent features, and each feature is only one example of equivalent or similar features, unless stated otherwise.

Referring to Fig. 1 to Fig. 10, the first embodiment of a high-voltage LED chip structure in a CSP package disclosed by the present invention includes: an n-type GaN layer 2, an active layer 3, a p-type GaN layer 4, a current spreading layer 5, The deep trench 6, the insulating layer 7, the metal conductive layer 8, the n-electrode 9a and the p-electrode 9b, the packaging substrate 10, the substrate electrode pad 11 and the fluorescent glue layer 12 are isolated. The isolation deep trench 6 separates the high-voltage chip epitaxial layer into two or more sub-chips, each sub-chip has independent p-electrodes and n-electrodes, and the insulating layer 7 isolates the metal conductive layer 8 from the p-type GaN, The metal conductive layer 8 and the p-electrodes 9a and n-electrodes 9b are metals with better conductivity and reflection properties such as Ag, Ni, Al, etc., and can adopt a single-layer metal structure or a multi-layer metal structure; The outer sidewall of the interval is sloped by a deep isolation trench 8, and an insulating layer 7 is formed on it, and a metal conductive layer 8 is formed on the slope of the n-type GaN layer 2, and extends to the p-type along the insulating layer 7 on the slope. An n-electrode is formed on the GaN layer 4 , and the n-electrode and the p-electrode are respectively welded to corresponding electrode pads 11 of the substrate. After the high-voltage chip is welded to the electrode pad of the substrate, the substrate is peeled off by laser lift-off method, and phosphor powder and a protective adhesive layer 12 are sprayed on the exposed n-type GaN layer 2 .

The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the inventions. The aspects of the specific embodiments should be considered as illustrative only and not restrictive. Accordingly, the scope of the invention is indicated by the appended claims rather than by the foregoing description. All changes that fall within the equivalent meaning and scope of the scope of the patent application shall be deemed to fall within the scope of the patent application.

Claims (5)

1. A high-voltage LED chip structure of CSP packaging, comprising a high-voltage LED chip, fluorescent glue, and a packaging substrate, is characterized in that the LED high-voltage chip is flip-chip welded on the packaging substrate, and each high-voltage chip includes a plurality of sub-chips, each The chiplets are separated by isolation deep trenches, and each chiplet includes an n-type GaN layer, an active layer, a p-type GaN layer, a current spreading layer, and an n-electrode and a p-electrode, wherein the n-electrode extends to the n-electrode through the metal conductive layer. On the slope of the GaN-type GaN, the metal conductive layer is isolated from the sidewall of the p-type GaN and the active layer through the insulating layer; the n-electrode and the p-electrode are both located on the p-type GaN and electrically isolated, and the n-electrode and the p-electrode correspond to the packaging substrate Electrode pads and interconnection wires are soldered together. 2. the high-voltage LED chip structure of CSP package according to claim 1, it is characterized in that described n electrode, p electrode and metal conductive layer adopt Ag, Al, Ni three kinds of conductivity and reflectivity all better metals, It adopts a single-layer metal structure or a multi-layer metal structure. 3. The CSP-packaged high-voltage LED chip structure according to claim 1, characterized in that the current diffusion layer can be an ITO film or a metal film. 4. The CSP-packaged high-voltage LED chip structure according to claim 1, characterized in that the insulating layer can be made of silicon nitride, silicon oxide or aluminum nitride, or can be a DBR structure composed of these materials. 5. The high-voltage LED chip structure of CSP package according to claim 1, characterized in that phosphor powder and a protective glue layer are formed by spraying on n-type GaN after peeling off the substrate.