TWI469314B - Method of manufacturing light emitting diodes - Google Patents

Description

Method for manufacturing light emitting diode

The present invention relates to a method of manufacturing a light-emitting diode.

As a new generation of third-generation light source, the light-emitting diode light source is generally favored by the market because of its long working life, energy saving and environmental protection. Moreover, the current light-emitting module composed of a light-emitting diode can generate a high-power, high-brightness light source. Therefore, it will replace the existing light sources such as traditional incandescent lamps extensively and revolutionarily, and become the main light source that meets the theme of energy conservation and environmental protection. However, in the manufacture of the light-emitting diode, the light-emitting diode wafer is first cut into a plurality of light-emitting diode wafer monomers, and then the plurality of light-emitting diode wafer monomers are placed one by one on a bottom plate, and then The LED package is packaged into a light-emitting diode in a single package, but the packaging method has low production efficiency, and it is difficult to achieve large-scale automated production, which is disadvantageous for cost reduction and largely hinders illumination. The popularity of diodes.

With the development of technology, an array package method in which all of the light-emitting diode chips are connected to the substrate at one time is gradually begun, that is, a plurality of arrays of light-emitting diode chips are simultaneously pressed into a layer coated with conductive paste. The bottom plate is such that all of the light-emitting diode wafers are simultaneously electrically connected to the bottom plate. However, since the light-emitting diode wafer is arranged in a dense array, when the light-emitting diode wafer is pressed into the conductive paste, the conductive particles in the conductive paste may be squeezed to Adjacent light-emitting diode wafers in the gap between adjacent light-emitting diode wafers There is a risk that the conductive particles will be turned on because they are in contact with each other, and there is a risk of short circuit. As the size of the light-emitting diode package is decreasing toward volume, adjacent light-emitting diode chips in the array package are getting closer and closer, and the gap between adjacent light-emitting diode chips is getting smaller and smaller. The risk of a short circuit between the light emitting diode chips is increased.

In view of the above, it is necessary to provide a method of manufacturing a light-emitting diode that can prevent mutual conduction between light-emitting diode wafers in an array package method.

A method for manufacturing a light-emitting diode, comprising the steps of: providing a light-emitting diode wafer, the light-emitting diode wafer comprising a substrate and an epitaxial layer grown from the substrate; and the light-emitting diode crystal The circular epitaxial layer is cut into a plurality of mutually separated light-emitting diode wafers, a gap is formed between adjacent light-emitting diode wafers; an insulating layer is disposed in a gap between adjacent light-emitting diode wafers; a bottom plate, the bottom plate is coated with a conductive paste, and the substrate and the LED body are inverted, so that each of the light emitting diode chips is connected with the conductive glue of the bottom plate, and the insulating layer blocks adjacent light emitting a conductive paste between the diode wafers; and coating the light emitting diode wafer with a light transmissive material to obtain a light emitting diode; wherein the insulating layer has a height higher than a top surface of the light emitting diode wafer The insulating layer penetrates into the conductive paste.

Compared with the conventional manufacturing method, in the manufacturing method of the above-mentioned light-emitting diode, an insulating layer is disposed between adjacent light-emitting diode wafers, and the insulating layer blocks the conductive adhesive between adjacent light-emitting diode wafers. Therefore, the risk of short circuit caused by the conduction of the conductive glue when the adjacent light-emitting diode chip is connected to the bottom plate is avoided.

10‧‧‧Light Emitting Diode Wafer

11‧‧‧Substrate

12‧‧‧ Epilayer

13‧‧‧Light Emitter Wafer

14‧‧‧ gap

15‧‧‧Insulation

16‧‧‧ solder balls

21‧‧‧floor

22‧‧‧Conductive adhesive

30, 40‧‧‧Lighting materials

111‧‧‧Upper surface

132‧‧‧ top surface

134‧‧‧ bottom

212‧‧‧ positive

224‧‧‧ conductive particles

1 is a flow chart of a preferred embodiment of a method of fabricating a light-emitting diode of the present invention.

2 is a light emitting diode wafer provided in the first step shown in FIG. 1.

3 is a schematic view showing the epitaxial layer of the light-emitting diode wafer shown in FIG. 2 cut into a plurality of light-emitting diode wafers.

4 is a schematic view showing the filling of an insulating layer in the gap of the LED array of the LED array shown in FIG.

FIG. 5 is a schematic view showing the placement of a solder ball on the light-emitting diode wafer shown in FIG.

FIG. 6 is a schematic view showing the LED array shown in FIG. 5 inverted and bonded to the substrate.

FIG. 7 is a schematic view showing the light-emitting diode wafer array shown in FIG. 6 fixed to the bottom plate.

FIG. 8a is a schematic view showing a single package of the light-emitting diode wafer shown in FIG. 7 by using a light-transmitting material.

FIG. 8b is a schematic view showing the light-emitting diode wafer shown in FIG. 7 integrally packaged by using a light-transmitting material.

FIG. 8c is a schematic view showing the substrate on the light-emitting diode wafer shown in FIG. 7 and then packaged with a light-transmitting material.

Referring to FIG. 1, a method for fabricating a light-emitting diode of the present invention includes the following steps. First, as shown in FIG. 2, a light-emitting diode wafer 10 is provided. The LED wafer 10 includes a substrate 11 and an epitaxial layer 12 grown from the substrate 11. The material of the substrate 11 may be sapphire, ruthenium or tantalum carbide. In the present embodiment, the substrate 11 is sapphire, and the epitaxial layer 12 is grown upward from the upper surface 111 of the sapphire substrate 11. The epitaxial layer 12 is a semiconductor constituting a p-n junction, and the material of the epitaxial layer 12 may be gallium arsenide, gallium arsenide, aluminum gallium arsenide or the like.

Next, as shown in FIG. 3, the epitaxial layer 12 of the light-emitting diode wafer 10 is cut into a plurality of light-emitting diode wafers 13. Each of the LED chips 13 includes a top surface 132 and a bottom surface 134. The bottom surface 134 of the LED wafer 13 is closely connected to the upper surface 111 of the sapphire substrate 11. The plurality of light emitting diode chips 13 are spaced apart from each other and arranged in an array. A gap 14 is formed between the adjacent two LED chips 13.

Next, as shown in FIG. 4, an insulating layer 15 is filled in the gap 14 between the LED chips 13, and the insulating layer 15 can be cured by light-transmitting photoresist under the action of light. The insulating layer 15 spaces the adjacent two LED chips 13 apart. The insulating layer 15 is perpendicular to the upper surface 111 of the sapphire substrate 11, and the height of the insulating layer 15 is slightly higher than the top surface 132 of the LED substrate 13.

Again, as shown in FIG. 5, a solder ball 16 is disposed on each of the positive and negative electrodes of the top surface 132 of each of the LED chips 13, so that each of the LED chips 13 can be connected to the outside by the solder balls 16. Electrical connection.

Further, as shown in FIG. 6 and FIG. 7, a bottom plate 21 provided with a circuit is provided, and a front surface 212 of the bottom plate 21 is coated with a layer of conductive adhesive 22, which may be an anisotropic conductive paste. The conductive paste 22 includes a resin adhesive and conductive particles 224 discretely distributed in the resin adhesive. The conductive paste 22 functions as a conductive layer by the conductive particles 224 therein.

The sapphire substrate 11 and the LED substrate 13 are inverted, so that the top surface 132 of the LED wafer 13 faces downward, and the top of the LED wafer 13 and the insulating layer 15 are pressed into the conductive paste 22 . Internally, the conductive paste 22 is extruded to cause the conductive paste 22 to be electrically conductive in the direction of force (ie, the vertical direction), so that the solder balls 16 on the LED chip 13 are electrically conductive and the adhesive film 22 and the bottom plate 21 Circuit connection.

When the conductive paste 22 on the bottom plate 21 is pressed by the light-emitting diode wafer 13 when pressed, stress is generated in the lateral direction (ie, the horizontal direction) of the conductive paste 22, and is generated from the light-emitting diode wafer 13. The tendency of the peripheral overflow, but because the insulating layer 15 is disposed in the gap 14 between the adjacent two light-emitting diode wafers 13, and the insulating layer 15 has a height higher than the top surface 132 of the light-emitting diode wafer 13, the insulating layer 15 can penetrate into the conductive adhesive 22 and block the conductive adhesive 22 between the adjacent light-emitting diode wafers 13, thereby preventing the overflowing conductive adhesive 22 from flowing to the side of the adjacent light-emitting diode wafer 13 The conductive particles 224 are prevented from being filled into the gaps 14 of the array of LEDs 13 to avoid the risk of short-circuiting by turning on the adjacent two-emitting diode chips 13.

Again, the conductive paste 22 is heated and cured at a high temperature to bond the light-emitting diode wafer 13 to the bottom plate 21 integrally. Then, as shown in FIG. 8a, each of the light-emitting diode chips 13 is covered with a light-transmitting material 30 to isolate the light-emitting diode chip 13 from the outside. The light transmissive material 30 can be made of high light transmission, high mechanical strength and strong moisture resistance such as epoxy resin, acrylic or silicone. Finally, the bottom plate 21 is cut so that each of the light-emitting diode chips 13 on the bottom plate 21 is separated from each other, and each of the light-emitting diode chips 13 forms a light-emitting diode. In addition, the insulating layer 15 located between the adjacent light-emitting diode chips 13 also has the effect of packaging, which ensures that each light-emitting diode package is intact after the cutting is completed.

Referring to FIG. 8b, all of the LED chips 13 may be integrally packaged by the light transmissive material 40 during packaging, so that all the LED chips 13 are integrally packaged together.

In FIGS. 8a and 8b, the light transmissive materials 30, 40 enclose the substrate 11 together with the light emitting diode chip 13. In addition, as shown in FIG. 8c, the sapphire substrate 11 of the bottom surface 134 of the LED chip 13 may be removed before packaging, and then each of the LED chips 13 may be packaged or all LEDs respectively. Wafer 13 integrated package in one .

In the above method for manufacturing a light-emitting diode, an insulating layer 15 is provided between adjacent light-emitting diode chips 13, and the insulating layer 15 blocks the conductive paste 22 between the adjacent light-emitting diode chips 13 and blocks The conductive particles 224 are filled into the gaps 14 between the adjacent light-emitting diode chips 13, thereby avoiding the risk of short circuit caused by the conductive paste 22 being turned on when the adjacent light-emitting diode chips 13 are connected to the bottom plate 21. .

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.

Claims (9)

A method for manufacturing a light-emitting diode, comprising the steps of: providing a light-emitting diode wafer, the light-emitting diode wafer comprising a substrate and an epitaxial layer grown from the substrate; and the light-emitting diode crystal The circular epitaxial layer is cut into a plurality of mutually separated light-emitting diode wafers, a gap is formed between adjacent light-emitting diode wafers; an insulating layer is disposed in a gap between adjacent light-emitting diode wafers; a bottom plate, the bottom plate is coated with a conductive paste, and the substrate and the LED body are inverted, so that each of the light emitting diode chips is connected with the conductive glue of the bottom plate, and the insulating layer blocks adjacent light emitting a conductive paste between the diode wafers; and coating the light emitting diode wafer with a light transmissive material to obtain a light emitting diode; wherein the insulating layer has a height higher than a top surface of the light emitting diode wafer The insulating layer penetrates into the conductive paste. The method for manufacturing a light-emitting diode according to claim 1, wherein the insulating layer is cured by a photoresist under the action of light. The method for manufacturing a light-emitting diode according to claim 1, wherein the bottom plate is provided with a circuit, and the top surface of the light-emitting diode chip is provided with a solder ball, and the light-emitting diode chip passes through The solder ball is electrically connected to the conductive paste of the bottom plate. The method for manufacturing a light-emitting diode according to claim 1, wherein the conductive paste is an anisotropic conductive paste. The method for manufacturing a light-emitting diode according to claim 1, wherein the conductive paste is cured by heat and then the light-emitting diode wafer is connected to the bottom plate. The method for manufacturing a light-emitting diode according to claim 1, wherein the light-transmitting material All of the light-emitting diode chips are integrally wrapped, so that all of the light-emitting diode chips are integrally packaged together. The method for manufacturing a light-emitting diode according to claim 1, wherein the light-transmitting material covers each of the light-emitting diode wafers so that each of the light-emitting diode wafers becomes an independent package. The method of manufacturing a light-emitting diode according to any one of claims 1 to 7, wherein the light-transmitting material coats the substrate together with the light-emitting diode wafer. The method for producing a light-emitting diode according to any one of claims 1 to 7, wherein the substrate is removed before the light-emitting diode wafer is coated with the light-transmitting material.