CN218069892U

CN218069892U - Eutectic flip LED chip

Info

Publication number: CN218069892U
Application number: CN202222342398.XU
Authority: CN
Inventors: 孙山峰
Original assignee: Wuxi Xinshijia Semiconductor Technology Co ltd
Current assignee: Wuxi Xinshijia Semiconductor Technology Co ltd
Priority date: 2022-09-02
Filing date: 2022-09-02
Publication date: 2022-12-16
Anticipated expiration: 2032-09-02

Abstract

The utility model relates to a semiconductor device technical field just discloses an eutectic flip-chip LED chip, including the sapphire substrate, the bottom of sapphire substrate is provided with N type gallium nitride layer, the bottom on N type gallium nitride layer is provided with P type gallium nitride layer, the bottom on P type gallium nitride layer is provided with multilayer metal, the bottom of multilayer metal is provided with the tin ball. According to the eutectic flip LED chip, the solder balls are directly prepared on the bonding pads of the multilayer metal to replace gold-tin alloy, so that the cost is reduced; when the solder ball is affected by high temperature and melts, the multilayer metal and the PCB can be welded and fixed, and key points of solder paste or solder paste brushing are not needed in the die bonding process, so that the process is simplified; the solder ball has low cost, can be made to have a thickness of more than 4um, has enough welding metal and high welding yield.

Description

Eutectic flip LED chip

Technical Field

The utility model relates to a semiconductor device technical field specifically is an eutectic flip-chip LED chip.

Background

The LED chip is a solid semiconductor device, is a core component of an LED lamp, namely a P-N junction, and has the main functions of: the electric energy is converted into light energy, the main material of the chip is monocrystalline silicon, the semiconductor wafer is composed of two parts, one part is a P-type semiconductor, holes are dominant in the P-type semiconductor, the other end is an N-type semiconductor, electrons are mainly on the side, when the two semiconductors are connected, a P-N junction is formed between the two semiconductors, when current is applied to the wafer through a lead, the electrons are pushed to a P region, the electrons and the holes are combined in the P region, and then the energy is emitted in the form of photons.

There are two main technologies for flip-chip LED chips.

The first method is that the metal on the surface of a chip bonding pad is pure gold, solder paste needs to be placed on a PCB bonding pad in the die bonding process, the solder paste is used for connecting an LED chip and the PCB after high temperature, the thickness of the pure gold on the surface of the chip bonding pad is 1.2 microns, and the cost is high; the soldering process needs to be performed with solder paste or brushed with solder paste, the process is complex, the solder paste between the bonding pads is easy to be connected with short circuit, and the production yield is low.

The second is that the chip bonding pad adopts gold-tin alloy, the soldering flux is coated on the PCB bonding pad in the die bonding process and volatilizes after high temperature, the gold-tin alloy is connected with the LED chip and the PCB, the thickness of the gold-tin alloy is generally more than 4 microns, and the cost is high; the thickness of the gold-tin alloy is only 4um, the amount of welding metal is small, insufficient welding, desoldering and large welding cavity are easy to occur, and the yield is low.

SUMMERY OF THE UTILITY MODEL

Technical problem to be solved

The utility model provides a not enough to prior art, the utility model provides an eutectic flip-chip LED chip possesses improvement LED flip-chip eutectic welding performance, reduces advantages such as eutectic pad cost of preparation, has solved pure gold welding in-process and need some tin cream or brush tin cream, and the technology is complicated, and the short circuit is connected easily to the tin cream between the pad, and the production yield is low, and gold tin alloy welded metal volume is few, appears rosin joint easily, desolders, the welding is hollow big, the problem that the yield is low.

(II) technical scheme

In order to achieve the above object, the utility model provides a following technical scheme: the utility model provides an eutectic flip-chip LED chip, includes the sapphire substrate, the bottom of sapphire substrate is provided with N type gallium nitride layer, the bottom on N type gallium nitride layer is provided with P type gallium nitride layer, the bottom on P type gallium nitride layer is provided with multilayer metal, the bottom of multilayer metal is provided with the tin ball.

Preferably, the bottom on P type gallium nitride layer is provided with spacing frame, multilayer metal is located spacing frame's inside, spacing frame's bottom is located the below of multilayer metal, the lateral surface of multilayer metal and spacing frame's inside wall fixed connection.

Preferably, the bottom of sapphire substrate is provided with stop gear, stop gear includes first movable sleeve, second movable sleeve and connecting plate, the bottom fixedly connected with fixed plate of connecting plate, stop gear's quantity is four, and four stop gear are evenly respectively at the side surface on N type gallium nitride layer and P type gallium nitride layer.

Preferably, the first movable sleeve is movably sleeved with the second movable sleeve, the second movable sleeve is movably sleeved with the connecting plate, and the top of the first movable sleeve is bonded with the bottom of the sapphire substrate.

Preferably, the size of the N-type gallium nitride layer is the same as that of the P-type gallium nitride layer, and the side surface of the first movable sleeve is overlapped with the side surfaces of the N-type gallium nitride layer and the P-type gallium nitride layer.

Preferably, the number of the multilayer metals is four, and the four multilayer metals are uniformly distributed at the bottom of the P-type gallium nitride layer.

Compared with the prior art, the utility model provides an eutectic flip-chip LED chip possesses following beneficial effect:

1. according to the eutectic flip LED chip, the solder balls are directly prepared on the bonding pads of the multilayer metal to replace gold-tin alloy, so that the cost is reduced; the die bonding process does not need to use solder paste or brush solder paste, so that the process is simplified; the tin ball is low in cost, can be made to be more than 4 mu m thick, is enough for welding metal, and is high in welding yield.

2. This eutectic flip-chip LED chip through set up spacing frame on the multilayer metal side surface, makes the tin ball when melting, can be located spacing frame's inside, is difficult for flowing other positions, and can carry on spacingly to the device through setting up four stop gear, prevents that it from appearing the skew condition when carrying out solid brilliant operation.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.

The structure, proportion, size and the like shown in the present specification are only used for matching with the content disclosed in the specification, so as to be known and read by people familiar with the technology, and are not used for limiting the limit conditions which can be implemented by the present invention, so that the present invention has no technical essential significance, and the modification of any structure, the change of proportion relation or the adjustment of size all fall within the scope which can be covered by the technical content disclosed by the present invention without affecting the efficacy and the purpose which can be achieved by the present invention.

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a front view of the present invention;

FIG. 3 is a front sectional view of the present invention;

fig. 4 is a sectional view of the structure of the limiting mechanism of the present invention.

Wherein: 1. a sapphire substrate; 2. an N-type gallium nitride layer; 3. a P-type gallium nitride layer; 4. a plurality of layers of metal; 5. tin balls; 6. a limiting frame; 7. a first movable sleeve; 8. a second movable sleeve; 9. a connecting plate; 10. and (5) fixing the plate.

Detailed Description

In order to make the technical means, the creation features, the achievement purposes and the functions of the invention easy to understand, the invention is further explained below with reference to the specific embodiments, but the following embodiments are only the preferred embodiments of the invention, not all. Based on the embodiments in the implementation, other embodiments obtained by those skilled in the art without any creative work belong to the protection scope of the present invention. The experimental procedures in the following examples were carried out in a conventional manner unless otherwise specified, and materials, reagents and the like used in the following examples were commercially available unless otherwise specified.

Referring to fig. 1-4, an eutectic flip-chip LED chip includes a sapphire substrate 1, an N-type gallium nitride layer 2 fixedly connected to the bottom of the sapphire substrate 1, a P-type gallium nitride layer 3 fixedly connected to the bottom of the N-type gallium nitride layer 2, a plurality of layers of metal 4 fixedly connected to the bottom of the P-type gallium nitride layer 3, and solder balls 5 fixedly connected to the bottoms of the plurality of layers of metal 4.

Further, the bottom on P type gallium nitride layer 3 is provided with spacing frame 6, spacing frame 6's quantity is four, multilayer metal 4 is located spacing frame 6's inside, spacing frame 6's bottom is located multilayer metal 4's below, multilayer metal 4's side surface and spacing frame 6's inside wall fixed connection, when carrying out the solid brilliant to the device, need place it on the PCB board, melt under the high temperature condition as tin ball 5, make the LED chip move down, and spacing frame 6 and PCB board contact, tin ball 5 melts the back simultaneously and is located spacing frame 6's inside, avoid tin ball 5 to melt outside outflow.

Further, the bottom of sapphire substrate 1 is provided with stop gear, stop gear includes first movable sleeve 7, second movable sleeve 8 and connecting plate 9, the bottom fixedly connected with fixed plate 10 of connecting plate 9, stop gear's quantity is four, four stop gear evenly respectively in the side surface on N type gallium nitride layer 2 and P type gallium nitride layer 3, can carry out all-round spacing to the LED chip through four stop gear, prevent that it from appearing the skew condition when solid brilliant.

Further, the first movable sleeve 7 is movably sleeved with the second movable sleeve 8, the second movable sleeve 8 is movably sleeved with the connecting plate 9, the top of the first movable sleeve 7 is bonded with the bottom of the sapphire substrate 1, the first movable sleeve 7 can move on the second movable sleeve 8, the second movable sleeve 8 can move on the connecting plate 9, the first movable sleeve 7 can be fixed through the sapphire substrate 1 and prevented from moving downwards, when the solder balls 5 are melted, the sapphire substrate 1 moves downwards and drives the first movable sleeve 7 to move downwards, when the top of the second movable sleeve 8 is lapped with the bottom of the sapphire substrate 1, the second movable sleeve 8 can be driven to move downwards together, and the LED chip is not prone to position offset.

Further, the size of a dimension of the N-type gallium nitride layer 2 is the same as that of the P-type gallium nitride layer 3, the side surface of the first movable sleeve 7 is in lap joint with the side surfaces of the N-type gallium nitride layer 2 and the P-type gallium nitride layer 3, the fixing plate 10 and the PCB are fixed, the limiting mechanism is prevented from moving, the LED chip can be limited through the first movable sleeve 7, and the welding effect is improved.

Furthermore, the number of the multilayer metals 4 is four, the four multilayer metals 4 are uniformly distributed at the bottom of the P-type gallium nitride layer 3, and the LED chip is enabled to have better welding effect and better stability through the four multilayer metals 4, so that the shedding condition is not easy to occur.

The utility model discloses a use as follows:

when the device is used, the device is required to be subjected to die bonding, soldering flux is coated on a PCB pad firstly, then the device is prevented from being arranged on the PCB, the solder balls 5 are located at the PCB pad and are in contact with the soldering flux, then the solder balls 5 are subjected to high-temperature treatment, the soldering flux is volatilized, meanwhile, the solder balls 5 are melted in the limiting frame 6, and the solder balls 5 are melted and connected with the multilayer metal 4 and the PCB, so that the welding effect is realized.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the description in the above embodiments and the description is only preferred examples of the present invention, and is not intended to limit the present invention, and that the present invention can have various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications all fall into the scope of the claimed invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. An eutectic flip-chip LED chip, comprising a sapphire substrate (1), characterized in that: the bottom of sapphire substrate (1) is provided with N type gallium nitride layer (2), the bottom on N type gallium nitride layer (2) is provided with P type gallium nitride layer (3), the bottom on P type gallium nitride layer (3) is provided with multilayer metal (4), the bottom of multilayer metal (4) is provided with tin ball (5).

2. The eutectic flip LED chip of claim 1, wherein: the bottom on P type gallium nitride layer (3) is provided with spacing frame (6), multilayer metal (4) are located the inside of spacing frame (6), the bottom of spacing frame (6) is located the below of multilayer metal (4), the inside wall fixed connection of side surface and spacing frame (6) of multilayer metal (4).

3. The eutectic flip LED chip of claim 1, wherein: the bottom of sapphire substrate (1) is provided with stop gear, stop gear includes first movable sleeve (7), second movable sleeve (8) and connecting plate (9), the bottom fixedly connected with fixed plate (10) of connecting plate (9), stop gear's quantity is four, and four stop gear evenly distributed are at the side surface on N type gallium nitride layer (2) and P type gallium nitride layer (3).

4. The eutectic flip LED chip of claim 3, wherein: the first movable sleeve (7) is movably sleeved with the second movable sleeve (8), the second movable sleeve (8) is movably sleeved with the connecting plate (9), and the top of the first movable sleeve (7) is bonded with the bottom of the sapphire substrate (1).

5. The eutectic flip LED chip of claim 3, wherein: the size of N type gallium nitride layer (2) is the same with P type gallium nitride layer (3), the side surface of first movable sleeve (7) and the side surface overlap joint of N type gallium nitride layer (2) and P type gallium nitride layer (3).

6. The eutectic flip LED chip of claim 1, wherein: the number of the multilayer metals (4) is four, and the four multilayer metals (4) are uniformly distributed at the bottom of the P-type gallium nitride layer (3).