WO2015109577A1

WO2015109577A1 - Led and preparation method therefor

Info

Publication number: WO2015109577A1
Application number: PCT/CN2014/071505
Authority: WO
Inventors: 裴小明; 曹宇星
Original assignee: 上海瑞丰光电子有限公司
Priority date: 2014-01-26
Filing date: 2014-01-26
Publication date: 2015-07-30

Abstract

An LED and a preparation method therefor. The LED comprises a flip chip (1) of a horizontal structure and transparent encapsulation glue (5) for coating the flip chip (1) of the horizontal structure. The transparent encapsulation glue (5) located on each side face of the flip chip (1) of the horizontal structure has well-distributed and uniform thickness. The LED has high reliability and simple structure.

Description

LED and preparation method thereof

Technical field

The invention belongs to the technical field of LEDs, and in particular relates to an LED and a preparation method thereof.

Background technique

The LED product (no phosphor excitation, only the wafer emits a certain half-wavelength light) is packaged by fixing the LED on the support by means of die bonding or eutectic soldering, and connecting the positive electrode of the wafer with a gold wire. The positive electrode of the holder, the negative electrode of the wafer is connected to the negative electrode of the holder, and the transparent cup is filled in the holder cup. When filling the transparent plastic, it is necessary to work on a single bowl, which is inefficient. In addition, a large amount of dispensing equipment is required, the utilization rate of the packaging glue is low, and material waste is serious. Moreover, the connection of the wafer and the support electrode by the gold wire has certain reliability hazards, which limits the application of the LED product to some extent. In summary, the current LED products have the disadvantages of large preparation investment, low efficiency, and low reliability.

technical problem

It is an object of embodiments of the present invention to provide an LED having a simple structure and high reliability.

Technical solution

Embodiments of the present invention are achieved by an LED comprising a horizontal structure flip chip and a transparent encapsulant for covering the horizontal structure flip chip, and a transparent encapsulant located on each side of the horizontal structure flip chip The thickness is uniform and consistent.

Beneficial effect

In the embodiment of the invention, the horizontal structure flip chip is covered with a transparent adhesive, and the thickness of the transparent adhesive on each side of the horizontal structure flip chip is uniform and uniform, and the LED thus formed can be directly soldered to the application end without a conventional LED. The bracket package has a simple application process and no thermal resistance and reliability at the package level, which greatly reduces the preparation cost of the LED product, improves the reliability of the LED, and has a simple structure.

DRAWINGS

1 is a schematic structural view of a horizontal structure flip chip according to an embodiment of the present invention;

2 is a schematic structural view of an LED made of the horizontal structure flip chip shown in FIG. 1 (the upper surface is a flat surface);

3 is a schematic structural view of an LED made of the horizontal structure flip chip shown in FIG. 1 (the upper surface is a roughened surface);

4 is a schematic structural view of an LED made of the horizontal structure flip chip shown in FIG. 1 (the upper surface is a curved surface);

FIG. 5 is a flowchart of implementing an LED manufacturing method according to an embodiment of the present invention; FIG.

Figure 6 is a state diagram of the horizontal structure flip chip placed on the platform;

Fig. 7 is a view showing a state in which a transparent encapsulant is coated on the stage shown in Fig. 3.

Embodiments of the invention

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The implementation of the present invention will be described in detail below with reference to specific embodiments.

As shown in FIG. 1 to FIG. 4, an LED provided by an embodiment of the present invention includes a horizontal structure flip chip 1 and a transparent encapsulant 5 for covering the horizontal structure flip chip 1. The flip chip 1 is disposed on the horizontal structure. (or called flip chip) The transparent encapsulant on each side is uniform and uniform in thickness. It should be noted that the horizontal structure flip chip can emit visible light of a desired color without exciting the phosphor, and the electrode is located on the bottom surface. The LED thus formed can be directly soldered to the application end through the electrode of the wafer, without the need of a conventional LED bracket package, the application process is simple, the thermal resistance and reliability of the package layer are not greatly reduced, the manufacturing cost of the LED product is greatly reduced, and the LED is improved. Reliability and simple structure.

Generally, the side of the transparent encapsulant 5 is flat, and the angle between the transparent encapsulant 5 and the upper surface of the transparent encapsulant is greater than or equal to 90°, which will make the LED light uniform. The top surface of the transparent encapsulant 5 is parallel to the plane of the bottom surface of the flip-chip 1 of the horizontal structure, as shown in FIGS. 2 to 4. In addition, the top surface of the transparent encapsulant 5 may also be a roughened surface or a curved surface to enhance the light extraction rate, as shown in FIGS.

FIG. 5 shows an implementation flow of an LED preparation method according to an embodiment of the present invention, which is described in detail below.

In step S101, a plurality of horizontal structure flip chips are positioned on the same platform, and a transparent encapsulant covering each horizontal structure flip chip is disposed on the platform.

In the embodiment of the present invention, a plurality of horizontal structure flip-chips 1 are first positioned on the same platform 4, and a transparent encapsulant 5 covering the horizontal structure flip-chips 1 is disposed on the platform 4, as shown in FIGS. It should be noted that the lower surface of the horizontal structure flip chip 1 is provided with two electrodes, one of which is a positive electrode and the other of which is a negative electrode, both of which are in surface contact with the stage 4, as shown in FIG. Here, the plurality of horizontal structure flip-chips 1 on the same platform 4 are coated with the transparent encapsulant 5, the efficiency is high, the transparent encapsulant 5 coating device is small, and the transparent encapsulant 5 is highly utilized.

When the transparent encapsulant 5 is applied, the horizontal structure flip chip 1 is positioned by an adsorption device having a plurality of micropores 40, as shown in FIG. After the openings of all the micro holes 40 are covered by the horizontal structure flip chip 1, the cavity 41 of the adsorption device is evacuated, thereby positioning the horizontal structure flip chip 1 on the same platform 4, and then The platform 4 is simultaneously coated with a transparent encapsulant 5 on a plurality of horizontal structure flip-chips 1. The transparent encapsulation coating is carried out on a platform having the function of fixing the wafer by vacuum adsorption, and the process method is simple and easy to implement. Specifically, the adsorption device has a plurality of micropores 40, a cavity 41 communicating with each micropore 40, and a valve 42 for sealing the cavity 41. The platform 4 is supported by the base 10, the cavity 41 is surrounded by the platform 4 and the base 10. The valve 42 is disposed between the base 10 and the platform 4, and the micro-hole 40 is disposed on the platform 4, such that The adsorption device has a simple structure and a relatively low cost. Preferably, the micropores have a diameter of 30 to 50 μm to enhance the adsorption of the horizontal structure flip chip.

In step S102, after the upper surface molding operation of the transparent encapsulant is performed and cured, each LED is cut.

In the embodiment of the invention, the upper surface of the transparent encapsulant 5 can be flattened by natural leveling, centrifugal rotation or mold forming. After the transparent encapsulant 5 is cured, each LED is cut out 6, as shown in Figure 7. Specifically, the transparent package film 7 (including the horizontal structure flip chip 1) is first removed from the platform 4, and the transparent package film 7 is divided by physical cutting to make each LED 6 are all covered by a transparent encapsulant of the same thickness. To enhance each LED 6 photon take-out rate, enhance the brightness of the LED product, and roughen the upper surface of the transparent package film 7 before cutting. During laser cutting, the side surface of the transparent encapsulant 5 is flattened, and the angle between the upper surface of the transparent encapsulant is greater than or equal to 90°, so that the intersecting surfaces are not collapsed, as shown in FIGS. 2 to 4. The surface of the horizontal structure flip chip 1 is evenly coated with the transparent encapsulant 5 to realize the wafer level transparent encapsulant coating, which greatly reduces the material waste of the transparent encapsulation coating process in the conventional package, thereby reducing the production of the LED product. Preparation costs.

In addition, the embodiment of the present invention can also perform an upper surface molding operation on the transparent encapsulant 5 to finally make each LED The top surface of 6 is formed into a curved surface for increasing the light extraction rate, as shown in FIG.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

An LED, comprising: a horizontal structure flip chip and a transparent encapsulant for covering the horizontal structure flip chip; the transparent encapsulant on each side of the horizontal structure flip chip has a uniform thickness Consistent.
The LED according to claim 1, wherein the transparent encapsulant has a flat side and an angle of 90° or more with an upper surface of the transparent encapsulant.
The LED of claim 2 wherein the top surface of the transparent encapsulant is a plane parallel to the bottom surface of the horizontal structure flip chip.
The LED of claim 3 wherein the top surface of the transparent encapsulant is a roughened surface.
The LED according to claim 2, wherein the top surface of the transparent encapsulant is a curved surface for increasing the light extraction rate.
An LED preparation method, characterized in that the method comprises the following steps:

Positioning a plurality of horizontal structure flip-chips on the same platform, and disposing a transparent encapsulant covering the horizontal structure flip chip on the platform;

After the surface of the transparent encapsulant is molded and cured, each LED is cut.
The method according to claim 6, wherein the upper surface of the transparent encapsulant is roughened before cutting.
The method according to claim 6, wherein the side of the transparent encapsulant is flattened when cutting, and the angle between the upper surface of the transparent encapsulant is greater than or equal to 90°.