TWI414089B - Method of packaging light emitting diode - Google Patents

Abstract

A method of packaging a light emitting diode includes providing a base with at least one concave defined thereon, bonding a corresponding light emitting diode chip in the bottom of the concave, coating glue on the light emitting diode chip, providing a mold to press the surface of the glue, and demoulding after the surface of the glue is flattened.

Description

Light emitting diode packaging method

The present invention relates to a method of packaging a semiconductor device, and more particularly to a method of packaging a light emitting diode.

The semiconductor light-emitting diode has been widely used in various fields, such as indicator lights, illumination lamps, display screens, etc., due to its high luminous efficiency, small size, light weight, and environmental protection.

Before applying the light-emitting diode to the above various fields, it is necessary to package the light-emitting diode wafer to protect the light-emitting diode wafer, thereby obtaining high luminous efficiency and long service life. The package of the light-emitting diode usually includes steps of solid crystal filling, potting, baking, and the like. Wherein, the solid crystal is to fix the LED chip in a recess of the package substrate; the glue is used to encapsulate the liquid encapsulation material with the LED package by injection or molding, and the LED is printed by the LED chip. The light can reach the external space through the encapsulating material and through the reflection of the inner wall of the groove.

However, in the process of curing the liquid encapsulating material, the surface of the encapsulating material after curing shrinks inward due to the surface tension, which causes the encapsulating layer to be concave, which affects the optical performance and appearance of the LED package structure.

In view of the above, it is necessary to provide a light emitting diode packaging method, and the light emitting diode package structure obtained by the packaging method has expected optical performance and appearance.

A light emitting diode packaging method includes:

Providing a package substrate having at least one receiving groove thereon;

Fixing the LED chip to the bottom of the accommodating groove;

Coating the encapsulant in the accommodating groove and covering the illuminating diode chip; and

After the mold is pressed onto the surface of the encapsulant to flatten the surface of the encapsulant, the mold is separated from the encapsulant.

The above packaging method presses the mold on the surface of the encapsulant, which can overcome the surface tension existing during the curing process of the encapsulant, thereby avoiding the concave surface of the encapsulant, and obtaining the LED package structure with the expected optical performance and appearance. .

Referring to FIG. 1, first, a package substrate 10 is provided. The package substrate 10 can be made of a material such as ceramic or the like which has good thermal conductivity. The package substrate 10 has a first surface 101 and an opposite second surface 102, which may be, for example, a top surface, and the second surface 102 may be, for example, a bottom surface. The top surface has at least one accommodating groove 12, and the accommodating groove 12 has an inner wall 121 which is inclined with respect to the surface of the package substrate 10. The accommodating groove 12 is for accommodating the illuminating diode chip 20. The number of accommodating grooves 12 can be changed according to the number and arrangement of the illuminating diode chips 20. The accommodating groove 12 may have an elliptical shape, a truncated cone shape or the like. Further, the circuit structure 14 is formed on the bottom surface, and the circuit structure 14 penetrates the package substrate 10 and is exposed to the bottom of the accommodating groove 12.

Next, the LED wafer 20 is fixed to the bottom of the accommodating groove 12. The LED device 20 is electrically connected to the circuit structure 14 on the package substrate 10. In this embodiment, the crystal chip 201 is used in a flip chip manner, for example, silver paste or the like, and the LED body 20 is printed. The two electrodes are connected to the circuit structure 14, respectively. In other embodiments, the LED array 20 can also be connected to the circuit structure 14 by means of die bonding. Preferably, the light emitting diode chip 20 is a blue light wafer.

Referring to FIG. 2 again, the encapsulant 30 is coated in the accommodating groove 12 and covers the illuminating diode chip 20. Preferably, the encapsulant 30 may further comprise phosphor powder, and a part of the blue light emitted by the LED chip 20 emits light and the other part of the blue light may be mixed into white light. Since the encapsulant 30 has a certain fluidity, the surface 301 of the encapsulant 30 tends to be concave due to the surface tension during the curing process. Therefore, after coating the encapsulant 30, the present invention provides a mold 40 before the encapsulant 30 is cured, so that the mold 40 is pressed against the surface 301 of the encapsulant 30, and the external force applied to the encapsulant 30 by the mold 40 is overcome. The surface tension of the encapsulant 30 makes the encapsulant 30 flat after curing, thereby ensuring the desired optical performance and appearance of the LED package structure.

In this embodiment, the surface of the mold 40 is convexly disposed downwardly, and the pressing arm 42 is pressed against the periphery of the surface 301 of the encapsulant 30 and abuts the inner wall 121 of the accommodating groove 12. Since the surface tension of the surface 301 of the encapsulant 30 is more concave due to the surface tension, it is pressed against the periphery of the surface 301 of the encapsulant 30, so that the encapsulant 30 is squeezed to the center portion, thereby destroying the encapsulant 30. The tendency of the recess.

Referring to FIG. 3 again, after the surface 301 of the adhesive 30 is flat and cured, the mold 40 is detached from the encapsulant 30 to obtain a light-emitting diode package structure. Preferably, the surface 301 of the encapsulant 30 is flush with the top of the accommodating groove 12. Further, a surface of the stamping arm 42 of the mold 40 that is in contact with the encapsulant 30 is further provided with a release film 50 to facilitate better separation from the encapsulant 30 during demolding.

It can be understood that when the mold 40 is pressed against the surface 301 of the encapsulant 30, it is not limited to the above-described embodiment of the peripheral surface 301 of the press-on encapsulant 30. Referring to FIG. 4, the mold 41 used in another embodiment of the present invention has a flat surface and is pressed against the entire surface 301 of the encapsulant 30, so that the surface 301 of the encapsulant 30 can be flattened. Further, in order to facilitate demolding, a layer of the release film 50 may be provided on the surface of the mold 41.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧Package substrate

101‧‧‧ first surface

102‧‧‧ second surface

12‧‧‧ accommodating slots

121‧‧‧ inner wall

14‧‧‧Circuit structure

20‧‧‧Light Diode Wafer

201‧‧‧Solid glue

30‧‧‧Package

301‧‧‧ surface

40, 41‧‧‧ mold

42‧‧‧press arm

50‧‧‧Dissecting film

FIG. 1 to FIG. 3 are schematic diagrams showing the steps of a method for packaging a light-emitting diode according to an embodiment of the present invention and a package structure of the light-emitting diode obtained by each step.

FIG. 4 is a schematic diagram showing the steps of a method for packaging a light emitting diode according to another embodiment of the present invention.

10‧‧‧Package substrate

121‧‧‧ inner wall

14‧‧‧Circuit structure

20‧‧‧Light Diode Wafer

30‧‧‧Package

301‧‧‧ surface

40‧‧‧Mold

42‧‧‧press arm

50‧‧‧Dissecting film

Claims (9)

A light emitting diode packaging method includes:
Providing a package substrate having at least one receiving groove thereon;
Fixing the LED chip to the bottom of the accommodating groove;
Coating the encapsulant in the accommodating groove and covering the illuminating diode chip;
The improvement consists in that the mold is pressed onto the surface of the encapsulant to smooth the surface of the encapsulant, and then the mold is separated from the encapsulant. The method of claim 2, wherein the surface of the mold is convexly provided with a pressing arm, and the pressing arm is pressed against the peripheral surface of the encapsulant and within the receiving groove. The walls are adjacent. The method of claim 2, wherein the surface of the press arm that is in contact with the encapsulant is provided with a release film. The method of claim 2, wherein the surface of the mold is flat and pressed against the entire surface of the encapsulant. The method of encapsulating a light-emitting diode according to claim 1 or 4, wherein a surface of the mold is provided with a release film. The method of claim 2, wherein the light emitting diode chip is a blue light wafer, the package rubber comprises a fluorescent powder, and the light emitting diode wafer emits a fluorescent powder. The emitted light is mixed with the emitted blue light to form white light. The method of claim 2, wherein the package substrate further comprises a circuit structure, and the LED array is electrically connected to the circuit structure when the LED is fixed to the bottom of the receiving groove. The method of claim 2, wherein the light-emitting diode wafer is fixed on the package substrate in a flip chip manner. The method of claim 2, wherein the surface of the encapsulant is flush with the top of the receiving groove.