TWI423488B - Light emitting diode package structure - Google Patents

Description

Light emitting diode package structure

The present invention relates to a package structure, and more particularly to a light emitting diode package structure.

In the process of fabricating the LED package structure, the wafer is cut to obtain a plurality of light-emitting diode units separated from each other, and then the LED units are disposed on the carrier, wherein The light-emitting diode unit is fixed to the carrier by an adhesive. In order to enable the light emitted by the LED unit to be effectively reflected to improve the luminous efficiency, a translucent adhesive must be selected, so that the selection of the adhesive is limited, and the non-heat dissipation is not used. The light-transmitting adhesive reduces the heat dissipation efficiency of the LED package structure.

In addition, a reflective layer may be disposed between the bottom surface of the light-emitting diode unit and the adhesive, so that the light emitted by the light-emitting diode unit can be effectively reflected by the reflective layer to improve luminous efficiency. Although this method can make the selection of the adhesive more flexible, separately arranging the reflective layer on the back surface of the plurality of light-emitting diode units increases the processing time and difficulty, and increases the manufacturing cost. Furthermore, if the reflective layer is first disposed on the uncut wafer during the manufacturing process, and then the wafer and the reflective layer are cut, the manufacturing process can be simplified, but the in-wafer components are shielded by the reflective layer. However, the problem of reduced cutting accuracy may occur, or a large cutting space must be reserved, resulting in unnecessary useless space and increasing the cost of the product.

The invention provides a light emitting diode package structure, which is convenient in production.

The invention provides a light emitting diode package structure, which comprises a first substrate, a plurality of light emitting diode units independently of each other, a second substrate, a plurality of driving circuits independent of each other, and a plurality of electrical connecting members. The light emitting diode units are co-made on the first substrate. The driving circuit is fabricated on the second substrate. Each of the electrical connectors is connected to one of the light emitting diode units and a corresponding driving circuit thereof.

In an embodiment of the invention, the electrical connector comprises a plurality of bonding wires, and the LED unit is electrically connected to the corresponding driving circuit through the bonding wire by a wire bonding technique.

In an embodiment of the invention, the electrical connector comprises a plurality of conductive bumps, and the LED unit is electrically connected to the corresponding driving circuit through the conductive bumps by a flip chip bonding technique.

In an embodiment of the invention, the LED package structure further includes a carrier that provides a bearing surface, and the first substrate and the second substrate are disposed on the bearing surface.

In an embodiment of the invention, the LED package further includes an encapsulant disposed on the carrying surface and covering the LED unit on the first substrate and the driving circuit on the second substrate.

In an embodiment of the invention, the LED package further includes a reflective layer disposed between the first substrate and the carrier.

In an embodiment of the invention, the material of the reflective layer comprises aluminum, silver, copper or aluminum, nickel, titanium, silver, gold, copper, and ruthenium composite materials.

In an embodiment of the invention, the LED package further includes an adhesive disposed between the first substrate and the carrier or between the second substrate and the carrier.

In an embodiment of the invention, the adhesive material comprises silver glue or tin.

In an embodiment of the invention, the LED package structure further includes a control component electrically connected to the driving circuit to modulate the light emitting state of the LED unit.

In an embodiment of the invention, the LED package structure further includes a reflective layer disposed on an upper surface of each of the driving circuits.

In an embodiment of the invention, the material of the reflective layer comprises aluminum, silver or copper.

Based on the above, the plurality of light emitting diode units of the present invention are integrally formed on the first substrate and integrated with the first substrate, and the plurality of driving circuits are commonly fabricated on the second substrate and the second The substrate has an integrated structure, so that it is not necessary to cut the first substrate and the second substrate during the manufacturing process, and the manufacturing process of the light-emitting diode structure can be simplified, and the manufacturing cost can be reduced.

The above described features and advantages of the present invention will be more apparent from the following description.

1 is a top view of a light emitting diode package structure according to an embodiment of the invention Figure. 2 is a partial perspective view of the light emitting diode package structure of FIG. 1. Referring to FIG. 1 and FIG. 2 , the LED package structure 100 of the present embodiment includes a first substrate 110 , a plurality of LED units 120 independently of each other, a second substrate 130 , and a plurality of driving circuits 140 that are independent of each other. And a plurality of electrical connectors 150. The LED unit 120 is fabricated on the first substrate 110 to form an integrated structure with the first substrate 110. The driving circuit 140 is formed on the second substrate 130 to form an integrated structure with the second substrate 130. Each of the electrical connectors 150 is connected to one of the LED units 120 and its corresponding driving circuit 140, so that the LED units 120 are respectively connected to the driving circuits 140 and are adapted to be driven by the driving circuit 140. Glowing.

In this way, the first substrate 110 and the second substrate 130 do not need to be cut during the process of fabricating the LED package structure 100, and the manufacturing process of the LED structure 100 can be simplified, and the manufacturing cost can be reduced.

In detail, the electrical connector 150 of the embodiment is, for example, a bonding wire, and the LED unit 120 is electrically connected to the corresponding driving circuit 140 through the bonding wire by a wire bonding technique. The light emitting diode package structure 100 further includes a carrier 160. The carrier 160 provides a bearing surface 162, and the first substrate 110 and the second substrate 130 are disposed on the bearing surface 162. The carrier 160 of the present embodiment is, for example, a circuit substrate. However, the present invention is not limited thereto. In other embodiments, the lead frame may be replaced by a lead frame. In addition, in the embodiment, the LED package structure 100 further includes a control component 170 electrically connected to the driving circuit 140 to modulate the illumination state of the LED unit 120. For example, The light-emitting diode unit 120 is controlled to emit light by the control element 170, or the light-emitting intensity of each of the light-emitting diode units 120 is adjusted.

3 is a partial side elevational view of the light emitting diode package structure of FIG. 1 along direction D. Referring to FIG. 1 and FIG. 3 , in the embodiment, the LED package 100 further includes an encapsulant 180 disposed on the bearing surface 162 and covering the LED on the first substrate 110 . The unit 120 and the driving circuit 140 and the electrical connector 150 on the second substrate 130 protect the LED unit 120, the driving circuit 140 and the electrical connector 150.

Referring to FIG. 3, in the embodiment, the LED package structure 100 further includes a reflective layer 190a and a reflective layer 190b. The reflective layer 190a is disposed between the first substrate 110 and the carrier 160, and the reflective layer 190b is disposed on the reflective layer 190b. The upper surface of the drive circuit 140. Thereby, the light emitted by the LED unit 120 can be reflected by the reflective layer 190a and the reflective layer 190b to improve the luminous efficiency of the LED package structure 100. The material of the reflective layer 190a and the reflective layer 190b includes, for example, aluminum, silver, or copper, and is disposed on the upper surfaces of the first substrate 110 and the driving circuit 140, for example, by plating, vapor deposition, or vacuum sputtering. However, the present invention does not limit the materials of the reflective layer 190a and the reflective layer 190b. In other embodiments, it may be other suitable reflective materials.

Since the first substrate 110 and the second substrate 130 do not have to be cut during the process of fabricating the LED package structure 100 of the present embodiment, the configuration of the reflective layer 190a and the reflective layer 190b is not generated by the first substrate 110 or the The elements in the two substrates 130 are shielded by the reflective layer 190a or the reflective layer 190b to affect the cutting accuracy. In addition, since the first substrate 110 and the second substrate 130 of the embodiment are not cut into a plurality of portions separated from each other, the reflective layer 190a can be more conveniently disposed on the first substrate 110, and can be more convenient. The reflective layer 190b is disposed on the upper surface of the driving circuit 140.

The first substrate 110 and the second substrate 130 of the present embodiment are fixed to the carrier 160 by, for example, an adhesive 50a and an adhesive 50b. In detail, the adhesive 50a is glued between the reflective layer 190a and the carrier 160, and the adhesive 50b is glued between the second substrate 130 and the carrier 160. It is to be noted that, since the light-emitting diode package structure 100 of the present embodiment is respectively disposed with the reflective layer 190a and the reflective layer 190b over the adhesive 50a and the adhesive 50b, the light emitted by the light-emitting diode unit 120 has not yet reached the adhesive. The 50a and the adhesive 50b are reflected upward by the reflective layer 190a and the reflective layer 190b. Therefore, the light transmittance of the adhesive 50a and the adhesive 50b has no influence on the luminous efficiency of the LED package 100. Therefore, the material of the adhesive 50a and the adhesive 50b can be a non-transparent material having better heat dissipation, so that the light-emitting diode package structure 100 has better heat dissipation efficiency, thereby improving the light-emitting diode package structure 100. Photoelectric conversion efficiency. For example, a composite layer of aluminum, nickel, titanium, silver, gold, copper, and tantalum may be disposed between the adhesive 50a and the first substrate 120 (the heat transfer coefficient is about 50 to 1000 times that of the transparent silicone, and is suitable for Gluing with silver glue and solder paste), and a layer of aluminum, nickel, titanium, silver, gold, copper and ruthenium may be disposed between the adhesive 50b and the second substrate 130 to make the adhesive 50a and the adhesive 50b. The material can be made of silver glue (heat transfer coefficient is about 10~50 times that of transparent silicone) or tin (heat transfer coefficient is about 50~200 times of transparent silicone), so that the first substrate 110 and the carrier 160 are between There is a small temperature difference between the two substrates 130 and the carrier 160 (for example, 1 ° C). However, the present invention is not limited thereto. In other embodiments, the adhesive 50a and the adhesive 50b may be other suitable materials. It should be noted that the aluminum, nickel, titanium, silver, gold, copper, and tantalum composite multilayer structure disposed between the adhesive 50a and the first substrate 120 may be the reflective layer 190a, that is, the reflective layer 190a. The material can be nickel, titanium, silver, gold, copper or tantalum composite materials.

Considering the adhesion capability of each material and the maturity of mass production, the composite multilayer structure disposed between the adhesive 50a and the first substrate 120 and the composite multilayer structure disposed between the adhesive 50b and the second substrate 130 are composed of And the order of plating can be aluminum / titanium / nickel / silver, aluminum / titanium / nickel / gold, copper / nickel / silver, copper / nickel / gold, copper / tin, copper / nickel / silver / tin, copper / nickel / Gold/tin, aluminum/titanium/nickel/silver/tin or aluminum/titanium/nickel/gold/tin.

4 is a partial side elevational view of a light emitting diode package structure according to another embodiment of the present invention. Please refer to FIG. 4 , the difference between the LED package structure 200 of the present embodiment and the LED package structure 100 of FIG. 1 to FIG. 3 is that the LED unit 220 is electrically connected to the flip chip bonding technology. Corresponding drive circuits 240 are provided. In detail, in the embodiment, the electrical connector 250 is, for example, a conductive bump, the second substrate 230 is disposed on the bearing surface 262 of the carrier 260, and the first substrate 210 is disposed above the second substrate 230. The LED unit 220 of the first substrate 210 is electrically connected to the driving circuit 240 disposed on the second substrate 230 through the conductive bumps. The carrier 260 of the present embodiment is, for example, a circuit substrate. However, the present invention is not limited thereto. In other embodiments, the lead frame may be replaced by a lead frame.

In more detail, in the embodiment, the LED package structure 200 further includes a reflective layer 290 disposed on an upper surface of the driving circuit 240. Thereby, the light emitted by the LED unit 220 can be reflected by the reflective layer 290 to improve the luminous efficiency of the LED package structure 200. The material of the reflective layer 290 includes, for example, aluminum, silver, or copper, and is disposed on the upper surface of the driving circuit 240, for example, by electroplating, vapor deposition, or vacuum sputtering. However, the present invention does not limit the material of the reflective layer 290. In other embodiments, it may be other suitable reflective materials.

Since the second substrate 230 does not have to be cut during the process of fabricating the LED package structure 200 of the present embodiment, the configuration of the reflective layer 290 does not cause the cutting accuracy to be affected by the components in the second substrate 230 being reflected by the reflective layer 290. The problem and save the extra space needed for cutting.

The second substrate 230 of the present embodiment is fixed to the carrier 260 by, for example, an adhesive 60, wherein the adhesive 60 is glued between the reflective layer 290 and the carrier 260. The light emitted by the LED unit 220 is reflected upward by the reflective layer 290 before it reaches the adhesive 60. Therefore, the light transmittance of the adhesive 60 has no influence on the luminous efficiency of the LED package structure 200. Therefore, the material of the adhesive 60 can be a non-transparent material having better heat dissipation, so that the light-emitting diode package structure 200 has better heat dissipation efficiency, thereby improving the photoelectric conversion efficiency of the LED package structure 200. . For example, a composite layer of aluminum, nickel, titanium, silver, gold, copper, and tantalum may be disposed between the adhesive 60 and the second substrate 230 (the heat transfer coefficient is about 50 to 1000 times that of the transparent silicone, and is suitable for Glue with silver glue and solder paste), so that the adhesive glue 60 can be made of silver glue (heat transfer coefficient is about 10~50 times that of transparent silicone) or tin (heat transfer coefficient is about 50~200 times that of transparent silicone) The second substrate 230 and the carrier 260 may have a small temperature difference (for example, 1 ° C). However, the invention is not limited thereto. In other embodiments, the adhesive 60 may be other suitable materials.

Considering the adhesion capability of each material and the maturity of mass production, the composite multilayer structure disposed between the adhesive 60 and the second substrate 230 may be composed of aluminum/titanium/nickel/silver, aluminum/titanium. /nickel/gold, copper/nickel/silver, copper/nickel/gold, copper/tin, copper/nickel/silver/tin, copper/nickel/gold/tin, aluminum/titanium/nickel/silver/tin or aluminum/titanium / Nickel / Gold / Tin.

In addition, the LED package 200 further includes an encapsulant 280 disposed on the bearing surface 162 between the first substrate 210 and the second substrate 230 and covering the LEDs on the first substrate 210. The body unit 220, the driving circuit 240 on the second substrate 230, and the electrical connector 250 protect the LED unit 220, the driving circuit 240, and the electrical connector 250.

In summary, the plurality of light emitting diode units of the present invention are integrally formed on the first substrate and integrated with the first substrate, and the plurality of driving circuits are commonly fabricated on the second substrate. The second substrate has an integrated structure, so that it is not necessary to cut the first substrate and the second substrate during the manufacturing process, and the manufacturing process of the light emitting diode structure can be simplified, and the manufacturing cost can be reduced. In addition, since the first substrate and the second substrate do not have to be cut during the manufacturing process of the LED package structure of the present invention, the components in the first substrate or the second substrate are not shielded by the reflective layer, thereby affecting the cutting accuracy. Sexual problem. In addition, since the first substrate and the second substrate are not cut into a plurality of portions separated from each other, the reflective layer can be more conveniently disposed on the first substrate and the second substrate.

Furthermore, a reflective layer is disposed between the adhesive and the light emitting diode unit, so that the light emitted by the light emitting diode unit is reflected by the reflective layer before reaching the adhesive, so that the light transmittance of the adhesive is for the light emitting The luminous efficiency of the polar package structure has no effect. Therefore, the material of the adhesive can be selected from a non-transparent material having better heat dissipation, so as to improve the heat dissipation efficiency of the LED package structure, thereby enabling the LED package structure to have better photoelectric conversion efficiency. .

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

50a, 50b, 60. . . Adhesive

100, 200. . . Light emitting diode package structure

110, 210. . . First substrate

120, 220. . . Light-emitting diode unit

130, 230. . . Second substrate

140, 240. . . Drive circuit

150, 250. . . Electrical connector

160, 260. . . vehicle

162, 262. . . Bearing surface

170. . . control element

180, 280. . . Encapsulant

190a, 190b, 290. . . Reflective layer

1 is a top plan view of a light emitting diode package structure according to an embodiment of the invention.

2 is a partial perspective view of the light emitting diode package structure of FIG. 1.

3 is a partial side elevational view of the light emitting diode package structure of FIG. 1 along direction D.

4 is a partial side elevational view of a light emitting diode package structure according to another embodiment of the present invention.

100. . . Light emitting diode package structure

110. . . First substrate

120. . . Light-emitting diode unit

130. . . Second substrate

140. . . Drive circuit

150. . . Electrical connector

160. . . vehicle

162. . . Bearing surface

170. . . control element

180. . . Encapsulant

Claims (12)

A light emitting diode package structure comprising: a first substrate; a plurality of independent light emitting diode units independently fabricated on the first substrate; a second substrate; and a plurality of independent driving circuits On the second substrate; and a plurality of electrical connectors, each of the electrical connectors connecting one of the light emitting diode units and the corresponding driving circuit. The LED package structure of claim 1, wherein the electrical connectors comprise a plurality of bonding wires, and the LED devices are electrically connected through the bonding wires by wire bonding technology. To each of the corresponding drive circuits. The light emitting diode package structure of claim 1, wherein the electrical connectors comprise a plurality of conductive bumps, and the light emitting diode units are transparent to the conductive bumps by a flip chip bonding technique. Electrically connected to the respective corresponding driving circuits. The light emitting diode package structure of claim 1, further comprising a carrier, wherein a bearing surface is provided, and the first substrate and the second substrate are disposed on the bearing surface. The LED package structure of claim 4, further comprising an encapsulant disposed on the bearing surface and covering the LED unit and the second substrate on the first substrate The drive circuits on the above. The light emitting diode package structure of claim 4, further comprising a reflective layer disposed between the first substrate and the carrier. The light-emitting diode package structure according to claim 6, wherein the material of the reflective layer comprises aluminum, silver, copper or aluminum, nickel, titanium, silver, gold, copper and ruthenium composite materials. The illuminating diode package structure of claim 4, further comprising an adhesive disposed between the first substrate and the carrier or between the second substrate and the carrier. The light emitting diode package structure of claim 8, wherein the adhesive material comprises silver glue or tin. The illuminating diode package structure of claim 1, further comprising a control component electrically connected to the driving circuits to modulate the illuminating state of the illuminating diode units. The light emitting diode package structure of claim 1, further comprising a reflective layer disposed on an upper surface of each of the driving circuits. The light emitting diode package structure according to claim 11, wherein the material of the reflective layer comprises aluminum, silver or copper.