TW201041185A - LED chip for increasing front light emitting rate and its fabricating method - Google Patents

Abstract

Disclosed is a LED chip for increasing front light emitting rate, having a main light-emitting surface, a mounting surface, a plurality of laterals between the main light-emitting surface and the mounting surface, and a light emitting structure inside. Therein, the laterals and the mounting surface are coarsened to increase the diffuse-reflecting rate of non-front surfaces. Accordingly, there can be to increase the front light emitting rate from the main light-emitting surface, and even more to increase the mounting strength at the mounting surface. A method for fabricating the LED chip is also disclosed.

Description

201041185 VI. Description of the Invention: [Technical Field] The present invention relates to a semiconductor device for light emission, and more particularly to a light-emitting diode structure and a method of fabricating the same. [Prior Art] Ο

With the continuous development of technology, modern lighting equipment has gradually evolved from traditional light bulbs and fluorescent lamps to light-emitting diodes as light-emitting devices. Light Emitting Diode (LED) is a luminescent semiconductor component that can directly convert electrical energy into light energy with high efficiency. It has a long service life, low power consumption, small size, and is not easily damaged. The advantages that traditional light sources cannot compare with. With the successful development of high-intensity light-emitting diodes in recent years, light-emitting diodes have only been used in the past for indicator lights and instrument displays, and have evolved to become backlights for liquid crystal displays, and then extended to electronic lighting and public displays, such as Car lights, large video walls, and even the lighting inside the projector. The side surface and the wall surface formed by cutting in the conventional light-emitting diode crystal grain are designed as a flat surface, and the light emitted by the light-emitting diode causes the light to escape, and the light of the folded-back light has a refractive loss, which cannot be effectively concentrated on the front surface. Therefore, it is known that the luminous efficiency of the light-emitting diode grains is relatively low, and the relatively concentrated light output intensity cannot be achieved. In addition, conventional light-emitting diode dies are typically laser-processed to achieve separation by laser. However, the high-energy laser light leaves a black-focus ring laser # on the side of the light-emitting diode crystal #, so that the light emitted by the light-emitting diode crystal grains is blocked or absorbed, thereby affecting the luminous efficiency. 201041185 SUMMARY OF THE INVENTION In order to solve the above problems, the present invention increases the positive (four) (four) (four) in the provision method, can increase the non-positive body grain structure and its manufacturing side, the man's reflectivity, and the light collection surface is emitted, Light flat 隹 ♦ ^ field fr field set main hair road - to achieve greater light intensity. The second objective is to provide a light-emitting diode structure that increases the front light output rate.

strength.苒 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再 再The present invention does not disclose a light-emitting diode solar granule structure which increases the front light-emitting rate, and has a main hair ray, a joint surface, a light-emitting surface of the cable, and the joint surface. A plurality of sides and a illuminating structure are formed such that the sides and the bonding surface are roughened to increase the diffuse reflectance of the non-j surface. The purpose of this month and the resolution of its technical problems can be further realized by the following technical measures. In the foregoing light-emitting diode structure, the roughness of the sides and the bonding surface may be greater than the main light-emitting surface. In the foregoing light-emitting diode structure, the light-emitting diode structure may be a flip-chip type and include an epitaxial substrate, and the light-emitting structure is a semiconductor layer 'the main light-emitting surface system Formed on the epitaxial substrate, the bonding surface is provided with a plurality of electrodes. In the light-emitting diode structure of the light-emitting diode, the light-emitting diode die 4 201041185 may be in a wafer-level package and include an epitaxial substrate and an encapsulating resin. The epitaxial substrate is sealed to form the light-emitting structure, and the main light-emitting surface is formed on the encapsulating resin and provided with a plurality of electrodes. In the foregoing light-emitting diode structure, the side faces may be formed with a roughened ring near the periphery of the joint surface. The present invention also discloses a method for fabricating the above-described light-emitting diode crystal grain structure which increases the front light-emitting rate. First, a light-emitting diode wafer system has a main light-emitting surface, a joint surface, and a plurality of light-emitting structures. Next, the main light emitting surface of the light emitting diode wafer is attached to a cutting carrier film. Thereafter, performing a back-cutting step of cutting the light-emitting diode wafer from the bonding surface to form a plurality of light-emitting diodes having a corresponding light-emitting structure, the main light-emitting surface a plurality of sides between the joint surface and the joint surface. Finally, a sand blasting step is performed under the protection of the cutting carrier to cause the sides and the bonding surface to be roughened relative to the main light emitting surface to increase the non-frontal diffuse reflectance. It can be seen from the above technical solutions that the light-emitting diode structure and the manufacturing method thereof for increasing the front light-emitting rate of the present invention have the following advantages and effects: 1. The side and the bonding of the light-emitting diode structure can be The surface is roughened as one of the technical means to increase the non-frontal diffuse reflectance, and concentrate the light from the main light emitting surface to achieve the effect of light focusing and achieve a large light output intensity. 5 201041185

The bonding surface of the solar particle structure can be roughened as a technical hand by the light-emitting diode crystal, and can be used to increase the surface adhesion strength. The position of the roughening ring formed by the crystal structure of the light-emitting diode can be used as one of the technical means to push one, 1-±

TfX further increases the surface adhesion strength, and avoids emitting light to the side. The site φ A &&&&&&&&&&&&&&&&& ή Λ 乂 Increases the brightness of the light and reduces the heat of the grain. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described in detail with reference to the accompanying drawings. The method is implemented, so only the components and combinations related to the case are displayed. 'The components displayed in the stomach are not drawn in proportion to the actual number, shape and size of the actual implementation. Some ratios of scales are exaggerated or other Simplify the process to provide a clearer description. The actual number, shape and size ratio of the implementation is an optional design, and the detailed component layout may be more complicated. 〇 According to a first embodiment of the present invention, a light-emitting diode structure which increases the front light-emitting rate is illustrated by a cross-sectional view of the second embodiment. The light emitting diode structure 100 has a main light emitting surface m, a bonding surface 112, a plurality of side surfaces 11 3 between the main light emitting surface ln and the bonding surface 112, and a light emitting structure 〇2〇, wherein The side faces U3 and the joint faces 112 are roughened to increase the non-frontal diffuse reflection rate. The so-called diffuse reflection (or diffuse) means that when a pair of parallel incident light hits a rough surface, the surface of the 201041185 is uneven, so the incident rays are parallel to each other, and the reflection directions of the points are inconsistent, causing reflection. The light is randomly reflected in different directions inside the light-emitting diode structure 100. Specifically, the «light-emitting diode structure 1 〇〇 is a plurality of light-emitting diode dies formed by dicing a light-emitting diode wafer 1 如 (as shown in FIG. 3A ) One of the structures 100, the process of which is described later. In this embodiment, as shown in FIG. 1, the light-emitting diode structure 100 can be a flip-chip type and include an epitaxial substrate 130, and the light-emitting structure 120 is a semiconductor laminate. . The epitaxial substrate 13 can be a transparent sapphire substrate or other wafer-applied carrier. The material of the epitaxial substrate 130 may be alumina (A12 03), such as a sapphire substrate. The light emitting structure ι2 is a semiconductor stack and may include a first N-type gallium nitride (n_GaN), a second N-type gallium nitride, and a multiple quantum well structure (MQWs, multiple quantum)

WellS) and a P-type gallium nitride (P-GaN) can be formed using a wafer process deposition or/and a development etch technique. The epitaxial substrate 13 should have high light transmittance.

As a flip-chip type, the main light-emitting surface should be formed on the epitaxial substrate 130 as a main surface for light emission. The opposite surface of the main light-emitting surface is the joint surface 112 to be surface-bonded to be fixed to the carrier, such as a lead frame having a mirror structure or an intermediate type circuit carrier. The joint surface 112 is provided with a plurality of electrodes 141 and 142. The electrodes 141, 142 may be -N-type electrodes 141^pM 7 201041185 poles 142, respectively. The material of the N-type electrode 141 and the P-type electrode 142 may be chromium gold (Cr/Au). When there is a voltage difference between the N-type electrode 141 and the p-type electrode 142, the current in the light-emitting diode can easily flow from the P-pole (positive electrode) to the n-pole (negative electrode), so that the light-emitting structure 12 generates a light source. Most of the light source generated by the light emitting structure 120 can penetrate the epitaxial substrate 130 and be guided to the outside. Compared with the conventional non-clad-type light-emitting diode structure, the electrodes Ο I41 and 142 facing the bonding surface 112 do not block the main light-emitting surface 111, and the emitted light is not blocked and the loss is large. Part of the amount of light. As shown in Fig. 1, the side faces 113 and the joint faces 112 are roughened to increase the diffuse reflectance. When the light emitting diode structure 100 emits light from the light emitting structure 120, the light will have a diffuse reflection effect on the roughened side 113 and the bonding surface 112, and the light is further concentrated by the main light emitting surface. U1 is emitted to achieve the effect of light focusing and achieve a large light output intensity. Preferably, the side faces 113 are formed with a roughened ring 151 near the periphery of the joint surface 112. The roughened ring 151, referred to herein as a rough, toroidal surface, has a greater roughness than the roughness of the joint surface 112 and the remaining surfaces of the side surfaces 113 beyond the roughened ring 151. In addition, when the light emitting diode structure 00 is mounted on a carrier such as a lead frame or a printed circuit board, the roughened bonding surface 112 can be used to increase the surface adhesion strength and avoid emitting light to the sides ι3 It is absorbed by the black-focused laser marks (position corresponding to the roughened ring 丨5丨) to increase the brightness of the light and reduce the grain heat. In this embodiment, the roughening ring 151 is formed on a side edge of the light emitting structure 120. Referring to the process flow chart of FIG. 2 and the cross section of FIG. 3A to FIG. 3E, the present invention further describes the manufacturing method of the light-emitting diode structure 1 以 to illustrate the light-emitting diode crystal of the present invention. Structure 1 is concretely implementable and demonstrates its efficacy. As shown in FIG. 2, the manufacturing method of the present invention comprises the following steps: "Stepping up the light-emitting diode wafer", "attaching the main light-emitting surface of the light-emitting diode wafer to the cutting carrier film" Step 2, Step 3 of "Back Cutting", Step 4 of "Expanding the Cutting Carrier Film", and Step 5 of "Sandblasting". Step 4 "Expanding the cut carrier film" is an optional step. First, go to step 1. A light-emitting diode wafer 10 is provided as shown in Figure 3A. The light-emitting diode wafer 1 is composed of a plurality of the above-described uncut light-emitting diode crystal structures 100. The LED wafer 10 has a plurality of cross-interleaved scribe lines n to define the locations at which the LED structures 100 are formed. Then go to step 2. Referring to FIG. 3A, the main light-emitting surface ill of the photo-polar body B is attached to a cutting carrier film. The cutting carrier film 20 may have a stretchable stretch characteristic, and may be selected from One of UV tape taPe), thermal tape or blue tape. After that, go to step 3. See Figure 3B for a back 9 201041185

a cutting step of cutting the light-emitting diode wafer 10 by cutting the bonding surface [n] and cutting the light-emitting diode wafer 10 by using a laser cutting blade 3 to form the corresponding light-emitting structures The light-emitting diode has a grain structure of 1 Å. Preferably, the laser light does not cut through the cutting carrier film 2g, and: a plurality of isolated light-emitting diode grain structures 1 〇〇 still adhere to the cutting film 20, and the subsequent cutting is not affected. The film expansion step of the carrier film 2〇. In detail, as shown in Fig. 3C, after the back-cutting step 3, the side faces i 13 of the light-emitting diode structure 100 are exposed. In the present embodiment, after the back-cutting step 3, the side faces 113 of each of the light-emitting diode structure 1 are formed with a blackened annular laser mark 152 near the periphery of the bonding surface 112. . In detail, the annular laser mark 152 is formed by cutting the light-emitting diode wafer 10 when the high-energy laser light causes rapid heating to cut and melt the light-emitting diode wafer 1 . The damage generated on the track u leaves an annular laser mark. The annular laser mark 152 causes the light-emitting rays of the light-emitting diode structure to be broadcast, thereby affecting the luminous efficiency. The position of the annular laser mark 152 corresponds to the position of the above-described roughening ring 15丨. Since the above-described back-cutting step 3 is laser cutting, the annular laser trace 52 can be used as the outline of the roughened ring 151. Further, the surface black focus of the roughened ring 151 is simultaneously removed in the subsequent blasting step 5 to form the roughened ring 1 5 i. Thereafter, step 4 is preferably performed. Referring to FIG. 3D, a film expanding step is performed on the cutting carrier film 20 to expand a gap between the side faces 3 of the light emitting diode structure 1 以便 to facilitate the 201041185 Side 113 is sandblasted. In this step 4, the squeezing and stretching platform (not shown) stretches the cutting carrier film 20 to increase the gap between the luminescent diode structures (10). However, this step 4 can be omitted, and w will affect the process of the case. Finally, go to step 5. Referring to Figure 3, a beak sand (iron step under the protection of the cutting carrier 20 is applied to make the side faces U3 and the bonding face 112 thicker relative to the main light emitting face " Sewing 'to increase the non-frontal diffuse reflectance. In the blasting step, the surface black coke of the roughened ring 151 is simultaneously removed to make it transparent. In this step, one or more blastings may be utilized. The head 4 喷 blasting the joint surface US and the side surfaces 113, that is, performing a destructive processing operation on the joint surface 112 and the side surfaces 113, using the accelerated fine abrasive sand particles to the joint surface 112 The surface impact of the side surfaces 113 causes the joint surface 112 and the side surfaces 113 to have a granulation-like depression to form a matte surface or an erosive surface, so that the joint surface 112 and the side surfaces 11 3 are roughened. In order to increase the non-frontal diffuse reflectance, the roughness of the side faces 3 and the joint surface 112 may be greater than the main light emitting surface 11 and the light emitting diode grain structure 1 is emitted by the light emitting structure. When the light is shining, the light that is emitted will be on the roughened side 113, the The mouth surface 112 and the roughening ring 151 generate diffuse reflection, and concentrate the light from the main light-emitting surface 111 to achieve the effect of light focusing and achieve a large light-emitting intensity. The preferred step is: loss of 201041185 or reducing the viscosity of the cutting carrier film 20 to the main light-emitting surface 1U, so as to take out the light-emitting diode structure 100. Specifically, the loss or reduction of the cutting carrier film 20 The viscous method may include an ultraviolet light irradiation or a heating process to reduce the viscosity of the cutting carrier film 2, so that the cutting carrier film 10 can be stripped and separated from the main light-emitting surface lu, thereby obtaining a single separation. The light-emitting diodes have a grain structure of 1 〇〇. Please refer to the second figure, the side surfaces n3 of the light-emitting diode structure 单1 在 are close to the periphery of the joint surface 112. The roughened ring 15 1 is formed by sandblasting, and the side turns 13 and the joint surface 112 are roughened. Therefore, the original black focal ring-shaped laser mark 1 52 has been sandblasted. Instead of black focus, and formed into a rougher surface. As shown in FIG. 4A, the side faces 3 of the light-emitting diode structure 1 that have not been subjected to the sandblasting step have a blackened annular laser mark 152. As shown in FIG. 4B, After the blasting step, the annular black laser traces 15 2 having the blackening are formed into the light-transmissive roughening ring 15 1 ' and the side surfaces 113 of the light-emitting diode grain structures i 〇〇 The bonding surface 112 (including the electrodes 141, 142) is roughened to have a predetermined surface roughness. When the light emitting diode structure 100 emits light from the light emitting structure 120, the emitted light will be The roughened side surface 113 and the joint surface 112 generate diffuse reflection, and even the roughened ring 151 has the effect of enhancing diffuse reflection and increasing surface adhesion strength. Therefore, the light can be more concentrated from the main light-emitting surface 111 to achieve the effect of light focusing and to achieve a large light-emitting intensity. 12 201041185, in the second embodiment of the present invention, another light-emitting one-pole crystal structure for increasing the front light-emitting rate is disclosed in the wearing diagram of the first figure, which is the same as the first embodiment. The main components will be denoted by the same symbols and have the same or similar functions and effects, and will not be further described herein. The light emitting diode structure 200 has a main light emitting surface connected to the surface 112, a plurality of side surfaces 113 between the main light emitting surface U1 and the bonding surface ι 2, and a light emitting structure 120, wherein the side surfaces in and The joint surface 112 is roughened to increase the non-frontal diffuse reflectance. In this embodiment, the LED structure 2 can be a wafer level package and includes an epitaxial substrate 13A and a package resin 260. The encapsulation resin 26 is formed on the Lei The crystal substrate 13 is formed on the epitaxial substrate 130 to seal the light-emitting structure 120', and the main light-emitting surface is formed on the encapsulating resin 260 and is provided with a plurality of electrodes 141, 142'. . The encapsulating resin 260 can be formed on the epitaxial substrate 13 by a molding technique or a printing technique, and seals the light emitting structures 120 and the electrodes 141 and 142 to provide a fixing and protection effect, and at the same time, let the light heat outward. transfer. The encapsulating resin 26 may be a light transmissive material, and an epoxy resin or silicone rubber may be used as the material. The encapsulating resin 260 may further comprise a fluorescent material, a astigmatism material or a pigment, and is used in combination with the light-emitting diode structure to emit light of different colors. As shown in Fig. 5, since the side faces 113 and the joint faces 112 are 13 201041185, they are roughened surfaces which can increase the diffuse reflectance, and the roughened surface systems can be achieved through a sand blasting step. As shown in FIG. 6, during the blasting process, the main light-emitting surface ill of the light-emitting diode structure 200 is attached to the cutting carrier film 20, and the blasting heads 4 are used to The joint surface 112 and the side surfaces 113 are sandblasted to cause granulation-like depression and coarsening of the joint surface 112 and the side surfaces 113, so that the diffuse reflectance of the non-front surface can be increased. When the light emitting diode structure 2 发出 emits light from the luminescent structure 120, the light will have a diffuse reflection effect on the roughened side 113 and the bonding surface 112, and the light is further concentrated by the The main light-emitting surface 111 is emitted to achieve the effect of light focusing and to achieve a large light-emitting intensity. Preferably, the side surfaces 113 are formed near the periphery of the joint surface 112 to form a roughening ring 15 which is light transmissive and has a roughness greater than the joint surface 112 for increasing the surface adhesion strength and enhancing the side surface. Diffuse reflection effect, which in turn increases the brightness of the light and reduces the heat of the grain. In this embodiment, the roughening ring 151 is formed on a side edge of the epitaxial substrate 130. The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Although the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the present invention. Any simple modifications, equivalent changes and modifications made by those skilled in the art without departing from the technical scope of the present invention are still within the technical scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS 14 201041185 FIG. 1 is a schematic cross-sectional view showing a crystal structure of a light-emitting diode which increases a front surface light transmittance according to a first embodiment of the present invention. Fig. 2 is a flow chart showing a method of manufacturing a light-emitting diode grain structure for increasing front side light transmittance according to a first embodiment of the present invention. 3A to 3E are cross-sectional views showing the elements of the light-emitting diode structure in which the front light-emitting rate is increased in accordance with the first embodiment of the present invention. 4A to 4B are partial cross-sectional enlarged views of the light-emitting diode structure of the front side light-emitting rate according to the first embodiment of the present invention before and after blasting. Fig. 5 is a schematic cross-sectional view showing a crystal structure of a light-emitting diode which increases the front surface light-emitting rate according to a second embodiment of the present invention. Fig. 6 is a cross-sectional view showing the element of the light-emitting diode structure in which the front side light-emitting rate is increased in the sand blasting step according to the second embodiment of the present invention. [Description of main component symbols] 1 Providing a light-emitting diode wafer 2 Attaching the main light-emitting surface of the light-emitting diode wafer to the cutting carrier film 3 Back-cutting 4 Spreading the cutting carrier film 5 Sandblasting 15 201041185 Cutting road spraying Sand head side 10 Light-emitting diode wafer 11 20 Cutting carrier film 30 Laser cutting blade 40 1 00 Light-emitting diode grain structure 111 Main light-emitting surface 112 Bonding surface 113 120 Light-emitting structure 130 Epitaxial substrate 141 Electrode 142 Electrode 151 Roughening ring 152 annular laser mark 200 light-emitting diode grain structure 260 encapsulation resin

16

Claims (1)

201041185 VII. Patent application scope: A light-emitting diode structure having a front light-emitting rate, which has a main light-emitting surface, a joint surface, a plurality of sides between the main light-emitting surface and the joint surface, and a A light-emitting structure in which the sides and the joint surface are roughened to increase non-frontal diffuse reflectance. According to the scope of the patent application 帛1, the illuminating luminescence of the front side is Ο Ο 晶粒 晶粒 晶粒 晶粒 晶粒 Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο 。 Ο Ο 。 。 。 。 。 3. A light-emitting diode structure having a front light-emitting rate according to the first aspect of the patent application, wherein the light-emitting diode grain structure is a flip-chip type and includes an epitaxial substrate, and the light-emitting structure is In the case of a semiconductor stack, the main light emitting surface is formed on the epitaxial substrate, and the bonding surface is provided with a plurality of electrodes. 4. The luminescent diode dies structure according to the first aspect of the patent application, wherein the luminescent diode structure is a wafer level package type and includes an epitaxial substrate and a package. a resin, the encapsulating resin is formed on the epitaxial substrate to seal the light emitting structure. The main light emitting surface is formed on the encapsulating resin and provided with a plurality of electrodes. 5. A light-emitting diode structure having a front light-emitting rate according to the first aspect of the patent application, wherein the sides are formed with a roughened ring near the periphery of the joint surface. 6. A fabrication of a light-emitting diode structure for increasing front light output. 17 201041185 Method, comprising: providing a light-emitting diode wafer having a main light-emitting surface, a joint surface, and a plurality of light-emitting structures; Attaching the main light emitting surface of the light emitting diode wafer to the cutting carrier film; Performing a back-cutting step of cutting the light-emitting diode wafer from the bonding surface to form a plurality of light-emitting diode structures having corresponding light-emitting structures, wherein the main light-emitting surface is bonded to the main light-emitting surface a plurality of sides between the faces; and performing a sandblasting step 'under the protection of the cutting carrier film to roughen the sides and the bonding face relative to the main light emitting face to increase non-frontal diffuse reflectance . a method for fabricating a light-emitting diode grain structure according to the sixth aspect of the patent application, wherein the light-emitting diode grain structure is a flip-chip type and includes an epitaxial substrate, and the light emission The structure is a semiconductor stack. The main light emitting surface is formed on the crystal substrate, and the bonding surface is provided with a plurality of electrodes. a method for fabricating a light-emitting diode structure according to the sixth aspect of the patent application, wherein the light-emitting diode structure is a wafer-level package type and includes a remote crystal substrate and a An encapsulating resin is formed on the crucible substrate to seal the light emitting structure encapsulating resin. The main light emitting surface is formed thereon and a plurality of electrodes are disposed. 18 201041185 9. Illumination for increasing the front light emission rate according to item 6 of the patent application scope - a method for manufacturing a diode grain structure, wherein the sides are close to each other. A roughening ring is formed around the joint surface. 'In the method of manufacturing a polar body grain structure according to the sixth aspect of the patent application scope, the above-described back-cutting step is laser cutting' while forming the contour of the roughening ring, and At the same time, the surface black focus of the roughened ring was removed. According to the sixth aspect of the patent application, the method for manufacturing the front-end light-emitting illuminating-polar body grain structure, after the above-mentioned back-cutting step and before the blasting step, further comprises: stepping into the θ-diffusion step of the cutting load To enlarge the gap between the sides of the light-emitting diode dies. 〇 19