TWI423477B - Light emitting diode apparatus and method for enhancing luminous efficiency thereof - Google Patents

Description

Light-emitting diode device and method for improving luminous efficiency thereof

The invention relates to a light-emitting diode device, in particular to a light-emitting diode device which changes the shape of a substrate to increase the contact area with the phosphorescent material, so as to improve luminous efficiency.

Improving the luminous efficiency of light-emitting diodes is the focus of recent research. When the light-emitting diode is turned on, the light beam from the active layer diverges around. Part of the beam can be used effectively, and part of the beam is absorbed by the substrate. As shown in Figure 1. The conventional light emitting diode 10 is composed of a sapphire substrate 102, an LED die 104, and a package 106. The LED die 104 is epitaxially formed on the sapphire substrate 102 and generates a light beam. The die 104 and the sapphire substrate 102 are encapsulated and protected within the package 106. The arrows in the figure show the beams emitted from the LED dies 104. Obviously, the beam diverges in all directions. The solid arrow indicates that the light beam is emitted directly from the light emitting diode 10 that provides effective light. At the same time, dotted and dashed arrows indicate that the light beam is emitted toward the sapphire substrate 102.

The dotted arrow indicates that the light beam is isolated in the sapphire substrate 102, which does not contribute to the light emission of the light-emitting diode 10, mainly due to the phenomenon of total internal reflection caused by the absorption of the sapphire substrate 102. On the other hand, the dotted arrow indicates that the light beam has a chance to be released without being absorbed by the sapphire substrate 102. There is a need for an improved sapphire substrate 102 to enable more of the light beam trapped within the sapphire substrate.

In order to solve the above problems, U.S. Patent No. 6,791,119 discloses an improved substrate structure. As shown in FIG. 2, the light emitting diode includes a substrate having first and second opposing faces through which optical radiation of a predetermined wavelength can be transmitted. The substrate has a patterned cross section. A plurality of pedestals extend from the first surface of the substrate toward the second side. When a voltage is applied to the diode region on the second side, the diode region emits light of a predetermined wavelength range to the substrate. The mounting support on the diode region (opposite the substrate) is used to support the diode region. Therefore, after the voltage is applied to the diode region, the light emitted from the diode region to the substrate is emitted from the first surface. The first side of the substrate can include a plurality of grooves to define a plurality of triangular pedestals in the substrate. The slots may include side walls or sloping bottoms. The first side of the substrate may also include an array of via holes. The through holes may include tapered sidewalls or a bottom.

U.S. Patent No. 6,791,119 teaches that the improvement in luminous efficiency results in the formation of a slope due to the difference in the size of the first and second opposing faces. However, the design of the above-mentioned U.S. Patent No. 6,791,119 is mainly applicable to a light-emitting diode which is not encapsulated by a phosphorescent material, and thus is not easy to perform.

In order to overcome the above disadvantages and improve the luminous efficiency of the light-emitting diode, the present invention proposes to increase the contact area between the light-emitting diode substrate and the phosphor to improve the luminous efficiency. The present invention appears to be easier to implement than conventional techniques.

The purpose of the present application is to provide a light emitting diode device having improved luminous efficiency, comprising a light emitting diode die for providing a first light beam; a substrate having a trapezoidal cross section for supporting a light emitting diode die, first The light beam is transparent to the light beam; and the package body containing phosphorescent material and encapsulating the light emitting diode die and the substrate for fixing the light emitting diode die and the substrate, and providing the second when the phosphorescent material is excited by the first light beam beam.

According to the present invention, the substrate has grooves on its trapezoidal slope.

According to the present invention, the trench is subjected to plasma etching, sputter etching, ion beam etching, reactive ion etching, and laser cutting. Or mechanical cutting to form.

According to the present invention, the substrate is a sapphire substrate.

According to the present concept, the substrate is subjected to electron beam lithography, laser beam direct writing, gray-scale lithography, diamond ruling, and focused ion beam polishing. Ion beam milling) or laser ablation.

According to the concept of the present invention, the package is made of epoxy resin, silicone, polyetherimide, fluorocarbon polymer, polymethylmethacrylate (PMMA), Polycarbonate (PC), or Cycloolefin copolymer (COC).

Another object of the present invention is to provide a method for improving the luminous efficiency of a light-emitting diode device, comprising the steps of: a) forming a substrate having a trapezoidal cross section; b) generating a light-emitting diode crystal on the substrate; c) by emitting light The diode die provides a first beam; d) the package substrate, the light emitting diode die and the phosphor; and e) the phosphor is provided by the first beam to provide a second beam.

According to the present invention, the invention further includes the step of forming a plurality of grooves on the slope of the trapezoid.

According to the present invention, the grooves are formed by plasma etching, sputter etching, ion beam etching, reactive ion etching, laser cutting or mechanical cutting.

According to the present invention, the forming step is performed by electron beam etching, laser beam direct writing, gray scale etching, diamond cutting, focused ion beam milling or laser sputtering.

According to the present invention, the substrate is a sapphire substrate.

According to the concept of the present invention, the encapsulation step consists of epoxy resin, silicone, polyetherimide, fluorocarbon polymer, polymethyl methacrylate (PMMA), poly Carbonate (PC) or cyclic olefin copolymer (COC) is used.

Another object of the present invention is to provide a method for improving the luminous efficiency of a light-emitting diode device, comprising the steps of: a) generating a light-emitting diode crystal on a substrate; b) forming a substrate having a trapezoidal cross section; c) emitting light The diode die provides a first beam; d) the package substrate, the light emitting diode die and the phosphor; and e) the phosphor is excited by the first beam to provide a second beam.

According to the present concept, the invention further includes the step of forming a plurality of grooves on the trapezoidal slope.

According to the present invention, the grooves are formed by plasma etching, sputter etching, ion beam etching, reactive ion etching, laser cutting or mechanical cutting.

According to the present invention, the forming step is performed by electron beam etching, laser beam direct writing, gray scale etching, diamond cutting, focused ion beam milling or laser sputtering.

According to the present invention, the substrate is a sapphire substrate.

According to the concept of the present invention, the encapsulation step consists of epoxy resin, silicone, polyetherimide, fluorocarbon polymer, polymethyl methacrylate (PMMA), poly Carbonate (PC) or cyclic olefin copolymer (COC) is used.

Two embodiments embodying the features and advantages of the present invention are described in detail in the following description. The present invention is capable of various modifications in the various aspects of the invention and the invention is not intended to limit the invention.

First embodiment

3 and 4 illustrate a first embodiment of the present invention. In FIG. 3, the light emitting diode device 20 includes a substrate 202, a light emitting diode die 204, and a package 206. The light emitting diode die 204 can provide a first beam of light. The cross section of the substrate 202 is trapezoidal. The substrate 202 is used to support the light emitting diode die 204, so that the first light beam can penetrate the light emitting diode die 204. In this embodiment, the substrate 202 is a sapphire substrate. The package 206 contains a phosphor 2062 and is packaged with a light-emitting diode die 204 and a substrate 202 to fix the LED die 20 and the substrate 202 to provide a second beam when the phosphor 2062 is excited by the first beam. . In fact, the combination of the first beam and the second beam excites white light that is visible to the naked eye.

In contrast to the conventional technique of FIG. 1, the substrate 202 has a trapezoidal cross section and is not triangular. Assuming that both the heights of the substrates 102 and 202 are the same as the upper surface dimensions, the contact area of the substrate 202 with the phosphor 2062 in the package 206 is greater than the contact area of the substrate 102 in FIG. The structure of the substrate 202 can improve luminous efficiency.

The method of forming the light-emitting diode device 20 and combining light includes the following steps. First, a substrate 202 having a trapezoidal cross section is formed, and then a light emitting diode die 204 is formed on the substrate 202. The order in which the steps are formed and generated can be reversed. In other words, the light-emitting diode die 204 is formed on the substrate 202, and then the substrate 202 having a trapezoidal cross-section is formed.

The first light beam is provided by the light emitting diode die 204, and the substrate 202, the light emitting diode die 204, and the phosphor 2062 are packaged. Finally, the phosphor 6206 is excited by the first beam to provide a second beam. The combination of the first and second beams produces white light.

In this embodiment, the slope of the substrate 202 is formed by electron beam lithography, and laser beam direct writing, gray-scale lithography, and diamond cutting may also be used. (diamond ruling), focused ion beam milling, laser ablation, and the like. The package 206 is made of an epoxy resin, but is not limited to an epoxy resin. The package 206 may also be a silicone, a polyetherimide, a fluorocarbon polymer, a polymethyl methacrylate (PMMA), a polycarbonate (PC), or a cyclic olefin copolymer ( COC) to make.

According to the present invention, the cross section of the substrate 202 is trapezoidal. Therefore, the lower surface of the substrate 202 need not be larger than the upper surface. Please refer to Figure 4. The cross section of the substrate 202 is still trapezoidal, but its upper surface is larger than the lower surface. The contact area between the substrate 202 and the phosphor 6206 in the package 206 is thus increased, and the luminous efficiency is improved.

Second embodiment

5 to 7 illustrate a second embodiment of the present invention. As shown in FIG. 5, the light emitting diode device 30 includes a substrate 302, a light emitting diode die 304, and a package 306. The light emitting diode die 304 can provide a first beam of light. The substrate 302 has a trapezoidal cross section for supporting the light emitting diode die 304, so that the first light beam can penetrate the light emitting diode die 304. In the present embodiment, the substrate 302 is a sapphire substrate, which is the same as the first embodiment. The package 306 contains a phosphor 3062 and is packaged with a light emitting diode die 304 and a substrate 302 to fix the LED die 304 and the substrate 302 to provide a second beam when the first beam excites the phosphor 3062.

Unlike the first embodiment, the substrate 302 has a slot 3022 on the trapezoidal ramp 3024. The trench 3022 is formed by plasma etching. In practice, sputter etching, ion beam etching, reactive ion etching, laser cutting, or mechanical cutting may also be used. the same. The groove 3022 can increase the contact area of the substrate 302 with the phosphor 3062.

Similarly, if the heights of the substrates 102 and 302 are the same as the upper surface, the contact area of the substrate 302 with the phosphor 3062 in the package 306 is larger than the contact area of the substrate 102 in FIG. The structure of the substrate 302 can improve luminous efficiency.

In the present embodiment, the slope surface 3024 of the substrate 302 is formed by electron beam lithography, and laser beam direct writing, gray-scale lithography, and diamond can also be used. Diamond ruling, focus ion beam milling or laser ablation. The package 306 is made of an epoxy resin. As with the first embodiment, the package 306 is not limited to epoxy resin, but may also be silicone, polyetherimide, fluorocarbon polymer, polymethyl methacrylate. (PMMA), polycarbonate (PC), or cyclic olefin copolymer (COC).

According to the present invention, the cross section of the substrate 302 is trapezoidal. Therefore, the lower surface of the substrate 302 need not be larger than the upper surface. Please refer to Figure 6. The upper surface of the substrate 302 is larger than the lower surface thereof, but its cross section is still trapezoidal. The contact area between the substrate 302 and the phosphor 3062 in the package 2306 is thus increased, and the luminous efficiency is also improved.

It should be noted that any non-vertical ramp 3024 can be used with the present invention, and it is not limited that both ramps 3024 have slots 3022. As shown in Figure 7, an asymmetric trapezoid having a groove 3022 on a single ramp 3024 is also suitable for use in the present invention.

Although the present invention has been disclosed above by way of example, it is not intended to limit the invention. To the contrary, the scope of the invention is defined by the scope of the appended claims. quasi.

10. . . Light-emitting diode

102. . . Sapphire substrate

104. . . LED die

106. . . Package

20. . . Light-emitting diode device

202. . . Substrate

204. . . Light-emitting diode grain

206. . . Package

2062. . . Phosphorescence

30. . . Light-emitting diode device

302. . . Substrate

3022. . . groove

3024. . . Slope

304. . . Light-emitting diode grain

306. . . Package

3062. . . Phosphorescence

FIG. 1 illustrates a conventional light emitting diode of the prior art.

2 illustrates another modified light emitting diode in the prior art.

Figure 3 illustrates a first embodiment of the present invention.

Figure 4 illustrates another aspect of the first embodiment.

Figure 5 illustrates a second embodiment of the present invention.

Figure 6 illustrates another aspect of the second embodiment.

Figure 7 illustrates a combination of the first and second embodiments.

20. . . Light-emitting diode device

202. . . Substrate

204. . . Light-emitting diode grain

206. . . Package

2062. . . Phosphorescence

Claims (15)

A light emitting diode device having improved luminous efficiency, comprising: a light emitting diode die for providing a first light beam; a substrate having a trapezoidal cross section for supporting the light emitting diode die, the first light beam may be The substrate is light transmissive, the trapezoidal slope surface of the substrate has a plurality of grooves extending vertically to the inside of the substrate; and the package body containing the phosphor and encapsulating the light emitting diode die and the substrate for fixing the light The diode die and the substrate provide a second beam when the first beam excites the phosphor. The light-emitting diode device of claim 1, wherein the grooves are subjected to plasma etching, sputter etching, ion beam etching, reactive ion etching. Reactive ion etching, laser cutting or mechanical cutting is formed. The light-emitting diode device of claim 1, wherein the substrate is a sapphire substrate. The light emitting diode device of claim 1, wherein the substrate is subjected to electron beam lithography, laser beam direct writing, and gray scale etching. (gray-scale lithography), diamond ruling, focus ion beam milling or laser ablation. The light-emitting diode device of claim 1, wherein the package is made of epoxy resin, silicone, polyetherimide, fluorocarbon polymer, Made of polymethyl methacrylate (PMMA), polycarbonate (PC), or cyclic olefin copolymer (COC). A method for improving luminous efficiency of a light emitting diode device, comprising the steps of: forming a substrate having a trapezoidal cross section; forming a plurality of grooves extending vertically to the inside of the substrate on a trapezoidal slope surface of the substrate; generating a light emitting light on the substrate a polar body grain; providing a first light beam by the light emitting diode die; encapsulating the substrate, the light emitting diode die and the phosphor; and exciting the phosphor by the first light beam to provide a first Two beams. The method of claim 6, wherein the grooves are formed by plasma etching, sputter etching, ion beam etching, reactive ion etching, laser cutting or mechanical cutting. The method of claim 6, wherein the forming step is performed by electron beam etching, laser beam direct writing, gray scale etching, diamond ruling, focused ion beam milling, or laser sputtering. The method of claim 6, wherein the substrate is a sapphire substrate. The method of claim 6, wherein the encapsulating step comprises an epoxy resin, a silicone, a polyetherimide, a fluorocarbon polymer, and a polymethacrylic acid. Methyl ester (PMMA), polycarbonate (PC), or cyclic olefin copolymer (COC) is used. A method for improving luminous efficiency of a light-emitting diode device, comprising the steps of: generating a light-emitting diode crystal on a substrate; forming the substrate having a trapezoidal cross-section; forming a vertical extension on the trapezoidal slope of the substrate to the inside of the substrate a plurality of slots; providing a first light beam by the light emitting diode die; encapsulating the substrate, the light emitting diode die and phosphor; and exciting the phosphor by the first light beam to provide The second beam. The method of claim 11, wherein the slots are Plasma etching, sputter etching, ion beam etching, reactive ion etching, laser cutting or mechanical cutting. The method of claim 11, wherein the forming step is performed by electron beam etching, laser beam direct writing, grayscale etching, diamond cutting, focused ion beam milling, or laser ablation. The method of claim 11, wherein the substrate is a sapphire substrate. The method of claim 11, wherein the encapsulating step is an epoxy resin, a silicone, a polyetherimide, a fluorocarbon polymer, a polymethyl group. Methyl acrylate (PMMA), polycarbonate (PC), or cyclic olefin copolymer (COC) is used.