CN101355125A - LED wafer packaging method - Google Patents

Abstract

The present invention provides an LED chip packaging method, which uses a bracket carrying an LED chip to be placed in a mold, and a silicone lens covering the LED chip is formed on the bracket by a low-speed and low-pressure injection method. The present invention will not affect the gold wire used in wire bonding, so the quality yield can be ensured. Moreover, through such a mechanized production process, the use of manpower can be greatly reduced, thereby reducing costs and improving production efficiency.

Description

LED chip packaging method

technical field

The invention relates to an LED chip packaging method, in particular to a LED chip packaging method capable of mass production and shortening the process time.

Background technique

LED has the advantages of small size, long life, and low power consumption, so it is widely used in 3C product indicators and display devices. In view of this, in order to improve the competitiveness in the market, LED-related industries are all seeking to improve production yield and reduce production costs, so as to improve their own advantages. Currently, LED chip packaging structures generally include the following two types. Please refer to FIG. 1, as shown in the figure, it is to form at least one higher LED chip placement table 12 on a support 10 (the metal part is 101, and the plastic part is 102) made of metal and plastic, at least An LED chip 14 is placed on the LED chip placement table 12, and a lens 16 is covered on the LED chip 14. At this time, because the LED chip 14 is closer to the lens 16, it needs to be used for air extraction on one side, and the other side The glue filling method is to inject glue between the lens 16 and the LED chip 14 to form a hermetic package. However, under such a process method, it is very easy to cause air bubbles in the injected sealant due to simultaneous pumping, which will affect the luminous effect. Moreover, the process speed is quite slow. For example, the step of placing the lens on the LED chip , needs to be completed manually, etc., which makes the cost of the entire LED chip manufacturing process relatively high. Furthermore, please refer to FIG. 2, which is a schematic diagram of another embodiment of the prior art. Compared with FIG. There is no need for pumping, and there will be no bubble problem and the advantage of faster process speed. However, in the structure in FIG. 2 , because the step of placing the lens 16 on the LED chip 14 still needs to be completed manually, there are still problems such as human error and labor cost. Moreover, under such a structure, when the LED emits light, it is far away from the lens, so the luminous efficiency is poor.

Contents of the invention

The main purpose of the present invention is to provide a LED chip packaging method, which can form a silicone lens covering the LED chip on the LED bracket in a low-speed and low-pressure manner without damaging the gold wires bonded by wire bonding, so as to save manpower Advantages of cost, mass production and shortened process time.

Another object of the present invention is to provide an LED chip packaging method, which uses an automated production method to avoid unavoidable human errors when a large amount of manpower is used.

In order to achieve the above object, the present invention provides a LED chip packaging method, which includes firstly providing a bracket with an LED chip that has been bonded to the bracket by wire bonding; coating a silicone and plastic material on the surface of the bracket. Mixture; place the bracket in a mold, and inject a liquid silicone into the heating mold at a low speed, and inject the liquid silicone into the mold to reach 70% of the total volume of the silicone in the mold. When 95%, the pressure in the mold is reduced to below 20 Bar; and the bracket formed with the lens is taken out from the mold and packaged to complete the LED chip package.

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

The present invention injects liquid silica gel into the mold in which the bracket has been placed in a low-speed and low-pressure manner, and when the liquid silica gel is injected into the mold to about 70% to 95% of the total volume of the liquid silica gel that can be accommodated in the mold, the liquid silica gel in the mold is The pressure is reduced to a low pressure below 20Bar to form a silicone lens covering the LED chip on the bracket without causing damage to the gold wire, achieving the advantages of saving labor costs, mass production and shortening the process time. In addition, the mold of the present invention is applicable to the placement table with protruding LED chips or without protruding LED chip placement table, without changing the mold.

Description of drawings

Fig. 1 is a schematic diagram of an embodiment of LED chip packaging in the prior art;

2 is a schematic diagram of another embodiment of LED chip packaging in the prior art;

Fig. 3 is a flow chart of steps of the present invention;

4A and 4B are schematic diagrams of placing different forms of brackets in molds for low-pressure injection molding of silicone lenses according to the present invention;

FIG. 5 is a schematic diagram of a silicone lens formed on a bracket after using the LED chip packaging method of the present invention.

【Description of figure number】

10 brackets

101 metal parts

102 plastic part

12LED chip placement table

14 LED chips

16 lenses

20 LED chips

22LED bracket

24 dies

242 male mold

244 master mold

26 LED chip placement table

30 lenses

Detailed ways

Below in conjunction with accompanying drawing and embodiment, the specific embodiment of the present invention is described in further detail:

Please refer to FIG. 3, which is a flow chart of the steps of the LED chip packaging method of the present invention. First, as described in step S1, a bracket is provided, which is a bracket made of metal and plastic as in the prior art, and has at least one LED Chip placement table, the LED chip placement table can be set as the protrusion shown in FIG. 1 of the prior art or as shown in FIG. 2 without protrusion.

Furthermore, as described in step S2, the LED chip is fixed on the bracket by using the heat-conducting glue by using the surface-mounting technology, and wires such as gold wires are used for bonding (not shown in the figure) to connect the LED chip and the bracket; continue, as in step As described in S3, evenly coat the entire bracket with a coupling agent made of metal, such as plimer, which is a kind of silica gel and plastic material; as described in step S4, please refer to FIG. The support 22 is placed in the silicone injection mold 24 designed by adopting male and female molds 242, 244 as shown in Figure 4A, vacuumized, and injects liquid silicone with a very low injection pressure, such as two mixed with a ratio of 1:1. Dosage form of liquid silicone, heated to 110 ℃ ~ 150 ℃ mold, and when the liquid silicone is injected into the mold to reach 70% ~ 95% of the total volume of the silicone in the mold, the best is 80% full , so that the pressure in the mold drops below 20Bar, preferably below 15Bar, to prevent the gold wire from breaking and bending.

In addition, it should be emphasized that a group of molds of the present invention is composed of several structural molds as shown in Figure 4A. Therefore, during production, a group of molds will be able to simultaneously bond several surfaces with LED chips. Perform low-pressure injection of silicone. Furthermore, the mold of the present invention can be applied to the LED frame 22 with protruding LED chip placement platform 26 or without protruding LED chip placement platform 26 without changing the mold, as shown in FIG. 4A and FIG. 4B .

Again as described in step S5, after cooling, take out the bracket 22 with the lens formed on the surface, as shown in Figure 5, and perform an appearance inspection on the bracket 22 with the silicone lens 30, such as whether the lens floats, bubbles, Water streaks, lack of lens material, foreign objects, surface abnormalities or scratches, edge cracks, broken wires, and burrs to prevent exposed silicone; Finally, as described in step S6, remove unnecessary parts around the bracket, such as burrs and metal frames etc., and conduct electrical testing and packaging, and complete the LED chip packaging of the present invention.

The present invention injects liquid silica gel into the mold in which the bracket has been placed in a low-speed and low-pressure manner, and when the liquid silica gel is injected into the mold to about 70% to 95% of the total volume of the liquid silica gel that can be accommodated in the mold, the liquid silica gel in the mold is The pressure is reduced to a low pressure below 20Bar to form a silicone lens covering the LED chip on the bracket without causing damage to the gold wire, achieving the advantages of saving labor costs, mass production and shortening the process time. In addition, the mold of the present invention is applicable to the placement table with protruding LED chips or without protruding LED chip placement table, without changing the mold.

The above disclosures are only a few specific embodiments of the present invention, however, the present invention is not limited thereto, and any changes conceivable by those skilled in the art shall fall within the protection scope of the present invention.

Claims (9)

1, a kind of LED chip encapsulation method is characterized in that, comprises the following steps: providing a bracket on which an LED chip has been wire-bonded with the bracket; Coating a coupling agent of silica gel and plastic material on the surface of the bracket; The bracket is placed in a mold, and a liquid silicone is injected into the heated mold at a low speed, and the liquid silicone is injected into the mold to reach 70% of the total volume of the silicone in the mold. %～95%, the pressure in the mold is reduced to below 20 bars (Bar); and The LED bracket formed with the silicone lens is taken out from the mold and packaged to complete the LED chip package. 2. The LED chip packaging method according to claim 1, wherein the bracket includes a metal part and a plastic part. 3. The LED chip packaging method according to claim 1, wherein the liquid silicone is a two-component liquid silicone, and the mixing ratio of each component is 1:1. 4. The LED chip packaging method according to claim 1, characterized in that the mold is maintained at a heating temperature of 110°C-150°C. 5. The LED chip packaging method according to claim 1, characterized in that, when the liquid silicone is injected into the mold to reach 80% of the total volume of the silicone that can be accommodated in the mold, the pressure in the mold is reduced to below 15 Bar . 6. The LED chip packaging method according to claim 1, wherein the mold is designed with a separable male mold and a female mold. 7. The LED chip packaging method as claimed in claim 1, wherein the bracket has a protruding LED chip placement platform. 8. The LED chip packaging method as claimed in claim 1, further comprising an inspection step before packaging. 9. The LED chip packaging method according to claim 8, characterized in that the inspection step includes whether there are air bubbles, foreign matter, water marks, lack of material, etc., and whether the silicone lens is broken.

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