TWI425681B - Method for manufacturing led - Google Patents

Description

Light-emitting diode manufacturing method

The invention relates to a method for manufacturing a diode, in particular to a method for manufacturing a light-emitting diode.

Light-emitting diodes have been used in more and more occasions due to their high luminous efficiency, low energy consumption, and no pollution. They have a tendency to replace traditional light sources.

Conventional single light-emitting diodes are typically obtained by cutting a single piece of light-emitting diode substrate. The light-emitting diode substrate is composed of a substrate provided with metal electrodes on the upper and lower surfaces, a light-emitting chip fixed on the surface of the substrate, and a package covering the wafer. A plurality of holes penetrating the upper and lower metal electrodes are formed on the substrate, and an insulating material (usually green paint) abutting the metal electrodes is covered over the holes. The purpose of the insulating material is to support the package during the subsequent molding process, preventing it from falling into the hole and affecting the subsequent cutting of the hole.

However, the conventional insulating material is formed directly on the surface of the upper metal electrode, and it needs to occupy a considerable portion of the upper metal electrode area, resulting in less remaining area for wire bonding, which causes trouble for the subsequent gold wire bonding process. . Moreover, the reflectivity of the insulating material is low, and the light that is irradiated onto the surface of the insulating material by the light-emitting chip cannot be effectively reflected, which directly affects the light-emitting brightness of the light-emitting diode. In addition, the mechanical strength of such an insulating material is limited, and it may still collapse during the molding process of the package to cause sealing. The body falls into the hole, which affects the product yield.

Therefore, it is necessary to provide a method for manufacturing a light-emitting diode, which has a high product yield.

A method for manufacturing a light emitting diode includes the steps of: providing a substrate having a first metal layer and a second metal layer respectively formed on the upper and lower surfaces, wherein the first metal layer and the second metal layer are each divided into a plurality of independent trenches by a plurality of trenches The substrate has a plurality of through holes penetrating through the first metal layer and the second metal layer, and the inner wall surface of each of the through holes forms a metal connection layer connecting the first metal layer and the second metal layer; and the insulation is filled in each through hole a material; forming a metal strengthening layer on each surface of the insulating material; providing a plurality of light emitting wafers, electrically connecting the respective light emitting wafers to two adjacent first metal layers; forming a continuous package covering the light emitting wafers on the surface of the metal strengthening layers; A plurality of independent light-emitting diodes are formed by cutting the substrate along each of the through holes.

Since the metal reinforcing layer is formed on the surface of the insulating material of the through hole, the mechanical strength can be enhanced, so that the insulating material does not collapse when the package is formed, thereby improving the yield of the product.

10‧‧‧Substrate

100‧‧‧ trench

12‧‧‧through hole

20‧‧‧First metal layer

30‧‧‧Second metal layer

40‧‧‧Metal connection layer

50‧‧‧Insulation materials

60‧‧‧Metal strengthening layer

70‧‧‧Lighting chip

80‧‧‧ Gold wire

90‧‧‧Package

Figure 1 shows the first step in the fabrication of the light-emitting diode of the present invention.

Figure 2 shows the second step in the fabrication of the light-emitting diode of the present invention.

Figure 3 shows the third step in the fabrication of the light-emitting diode of the present invention.

Figure 4 is a plan view of Figure 3.

Figure 5 shows the fourth step in the fabrication of the light-emitting diode of the present invention.

Figure 6 is a plan view of Figure 5.

Figure 7 shows the fifth step in the fabrication of the light-emitting diode of the present invention.

Figure 8 shows the sixth step in the fabrication of the light-emitting diode of the present invention.

Figure 9 shows the seventh step in the fabrication of the light-emitting diode of the present invention.

Figure 10 shows the eighth step in the fabrication of the light-emitting diode of the present invention.

The invention discloses a method for manufacturing a light-emitting diode, the steps of which are as follows: First, a substrate 10 is provided as shown in FIG. The substrate 10 can be made of a material such as plastic, tantalum or ceramic, and has a flat top surface and a bottom surface.

Then, as shown in FIG. 2, a first metal layer 20 and a second metal layer 30 are respectively formed on the top surface and the bottom surface of the substrate 10 by electroplating or evaporation. The first metal layer 20 and the second metal layer 30 respectively cover the entire top surface and the bottom surface of the substrate 10, and the two are parallel to each other. The material of the first metal layer 20 and the second metal layer 30 may be selected from metal materials having better conductivity such as aluminum, copper, and silver.

Thereafter, a plurality of through-holes 12 distributed in a matrix are formed on the substrate 10 by drilling or otherwise as shown in FIGS. 3-4. The through holes 12 all penetrate the first metal layer 20 and the second metal layer 30 vertically.

Subsequently, as shown in FIG. 5-6, a plurality of parallel trenches 100 are formed on the first metal layer 20 and the second metal layer 30, so that the first metal layer 20 and the second metal layer 30 are both divided by the trenches 100. For multiple independent strips. Each trench 100 is located between two adjacent vias 12 and exposes the top surface of the substrate 10. At the same time, a metal connection layer 40 connecting the first metal layer 20 and the second metal layer 30 is formed on the inner wall surface of each of the through holes 12. Due to the connection of the metal connection layer 40, the first metal layer 20, the second metal layer 30 and the metal connection layer 40 on the left side of each via hole 12 together form a first pin (not labeled), and the first metal layer 20 on the right side. The second metal layer 30 and the metal connection layer 40 together form a second pin (not shown).

Then, the insulating material 50 is filled in each of the through holes 12 as shown in FIG. The insulating material 50 can be a green mask or other suitable insulating material. The insulating material 50 fills only the upper portion of the through hole 12 and leaves the lower portion of the through hole 12 to facilitate the subsequent cutting process. The top surface of the insulating material 50 is flush with the top surface of the first metal layer 20, and the bottom surface is higher than the bottom surface of the substrate 10.

Thereafter, a metal reinforcing layer 60 is formed on each of the insulating material 50 and the top surface of the first metal layer 20 as shown in FIG. The metal strengthening layer 60 may be made of a material such as gold, silver, copper, aluminum, or the like, and is preferably gold in this embodiment to protect the first metal layer 20 from oxidation. The metal strengthening layer 60 completely covers the top surface of the insulating material 50 and partially covers the top surface of the first metal layer 20. The adjacent metal strengthening layers 60 are separated by the trenches 100 to avoid shorting. The top surface of the first metal layer 20 is only partially exposed to a portion of the adjacent trench 100 due to being partially covered by the metal strengthening layer 60.

Subsequently, an illuminating wafer 70 is attached to the top surface of each of the metal reinforced layers 60 as shown in FIG. The luminescent wafer 70 can adopt gallium nitride, indium gallium nitride, aluminum indium gallium nitride, gallium phosphide Made of semiconductor luminescent materials. The luminescent wafer 70 is fixed to the metal reinforced layer 60 at a position corresponding to the first pin by an adhesive (not shown). The illuminating wafers 70 are respectively connected to the adjacent two metal reinforced layers 60 through the two gold wires 80. One of the gold wires 80 is connected to the position of the corresponding first pin on the metal reinforced layer 60 where the luminescent wafer 70 is located, and the other gold wire is connected. 80 is connected to the position of the corresponding second pin on the adjacent metal strengthening layer 60.

Then, the package 90 is formed on the substrate 10. The package 90 is made of a transparent material such as epoxy resin, polycarbonate, or polymethyl methacrylate. The package body 90 may be doped with phosphor powder (not shown) to change the color of the light emitted from the light-emitting wafer 70. The phosphor powder can be made of a fluorinated material such as yttrium aluminum garnet, phthalate compound, nitride, oxynitride, etc., depending on actual needs. The package body 90 covers the top surface of the metal strengthening layer 60, the exposed first metal layer 20, and the top surface of the substrate 10, thereby isolating the luminescent wafer 70 from the external environment. Due to the support of the metal strengthening layer 60, the pressure resistance of the insulating material 50 is enhanced, so that it is difficult to collapse during the molding of the package 90. Further, since the insulating material 50 is filled inside the through hole 12, the thickness thereof is larger than that of the insulating material bonded to the upper metal layer in the prior art, and the mechanical strength thereof can be further improved.

Finally, the substrate 10 is cut along the inner wall of each of the through holes 12 to be separated into a plurality of independent light-emitting diodes as shown in FIG.

Since the metal strengthening layer 60 itself can conduct electricity, the gold wire 80 can be directly struck on the metal strengthening layer 60, so that the problem that the wire bonding is inconvenient due to the too small wire bonding area does not occur. Moreover, the higher reflectivity of the metal strengthening layer 60 can effectively reflect the light emitted by the light-emitting chip 70, thereby improving the light-emitting brightness of the light-emitting diode.

It can be understood that the metal strengthening layer 60 can also cover only the surface of each insulating material 50 to completely expose the top surface of the first metal layer 20, and the light emitting wafer 70 can be directly fixed on the first metal layer 20 and the gold wire 80 is It is struck on the adjacent first metal layer 20. Of course, the metal strengthening layer 60 can also completely cover the top surface of each of the insulating material 50 and the first metal layer 20. The light-emitting chip 70 and the wire bonding position are the same as those of the foregoing partial covering. In addition, the light-emitting chip 70 can also be directly fixed on the top surface of the substrate 10 exposed in the trench 100, and then connected to the first pin and the second pin through the gold wire 80. Of course, the light-emitting chip 70 can also be directly fixed to the surfaces of the first pin and the second pin by flip-chip, thereby avoiding the use of the gold wire 80.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art will be included in the following claims.

10‧‧‧Substrate

100‧‧‧ trench

12‧‧‧through hole

20‧‧‧First metal layer

30‧‧‧Second metal layer

40‧‧‧Metal connection layer

50‧‧‧Insulation materials

60‧‧‧Metal strengthening layer

70‧‧‧Lighting chip

80‧‧‧ Gold wire

90‧‧‧Package

Claims (10)

A method for manufacturing a light emitting diode includes the steps of: providing a substrate on which upper and lower surfaces respectively form a first metal layer and a second metal layer, wherein the first metal layer and the second metal layer are each divided into a plurality of independent regions by a trench, and the substrate a plurality of through holes penetrating through the first metal layer and the second metal layer are formed, and a metal connection layer connecting the first metal layer and the second metal layer is formed on the inner wall surface of each of the through holes; and each of the through holes is filled with an insulating material; Forming a metal strengthening layer on the surface of each insulating material, the adjacent metal strengthening layers are separated by the grooves; providing a plurality of light emitting chips, electrically connecting the respective light emitting chips to the adjacent two first metal layers; forming on the metal strengthening layer A continuous package covering the light-emitting wafer; the substrate is cut along the through hole to form a plurality of independent light-emitting diodes. The method of manufacturing a light-emitting diode according to claim 1, wherein a top surface of the insulating material is flush with a top surface of the first metal layer. The method of manufacturing a light-emitting diode according to claim 2, wherein the bottom surface of the insulating material is higher than the bottom surface of the substrate. The method of manufacturing a light-emitting diode according to claim 1, wherein the metal strengthening layer further covers the first metal layer. The method for producing a light-emitting diode according to any one of claims 1 to 4, wherein the light-emitting wafer is fixed on the metal reinforcing layer. A method of manufacturing a light-emitting diode according to any one of claims 1 to 4, wherein Each of the light-emitting wafers is connected to an adjacent two metal-reinforced layer by a two gold wire. The method for manufacturing a light-emitting diode according to any one of claims 1 to 4, wherein the through holes and the grooves are alternately distributed on the substrate. The method of manufacturing a light-emitting diode according to any one of claims 1 to 4, wherein the insulating material comprises green lacquer. The method for producing a light-emitting diode according to any one of claims 1 to 4, wherein the metal strengthening layer is made of gold. A method for manufacturing a light emitting diode includes the steps of: providing a substrate on which upper and lower surfaces respectively form a first metal layer and a second metal layer, wherein the first metal layer and the second metal layer are each divided into a plurality of independent regions by a trench, and the substrate a plurality of through holes penetrating through the first metal layer and the second metal layer are formed, and a metal connection layer connecting the first metal layer and the second metal layer is formed on the inner wall surface of each of the through holes; and each of the through holes is filled with an insulating material; Forming a metal strengthening layer on the surface of each insulating material, the metal strengthening layer further covering the first metal layer; providing a plurality of light emitting chips, electrically connecting each of the light emitting chips to the adjacent two first metal layers; forming a cover light on the metal strengthening layer a continuous package of the wafer; the substrate is cut along the through hole to form a plurality of independent light emitting diodes.