TW506145B - High Luminescence LED having transparent substrate flip-chip type LED die - Google Patents

Abstract

A high luminescence LED having transparent substrate flip-chip type LED die is disclosed, which comprises a base substrate, a flip-chip type LED die having transparent substrate, a covering substrate. The center region of the covering substrate has a hole which is formed by surrounding the tilted sidewall. The flip-chip type LED die is accommodated in the hole in the center region. The base substrate is separated into two parts by a middle insulation region, which is connected to the two electrodes of the LED die respectively. The base substrate is formed by material with high thermal conductivity and high electrical conductivity for large current conduction and heat dissipation. A transparent resin or epoxy is used to fill the hole in the center region, and encapsulate the LED die. Since light can direct transmit through it, or is reflected back from the LED die, or is reflected from the sidewall of the hole for redirection and then exits out of the covering substrate from the hole in the center region, therefore high-intensity light can be emitted.

Description

506145 V. Description of the invention (υ Field of the invention The present invention relates to a light-emitting diode, and more particularly to a high-brightness light-emitting diode with flip-chip light-emitting diode grains. BACKGROUND OF THE INVENTION Low power consumption, small size, and long service life 'are currently widely used in home appliances audio indicators, mobile phone backlights, light-emitting diode signage, automotive third brake lights and other applications. In recent years, due to New light-emitting diode materials such as indium gallium indium (A 1 G a I η Ρ) and indium gallium nitride (A 1 G a I η Ν) have been successfully developed, so that the brightness of the light-emitting diode can be further improved. Enhancement. Therefore, it is possible to replace traditional incandescent light bulbs with light emitting diodes in many applications. At present, the application of light emitting diodes can be seen in applications such as traffic lights, car taillights and direction lights. In the future, with light emitting diodes The increase in body brightness is more likely to further replace the current common lighting sources such as fluorescent tubes and power-saving bulbs. The operating current of a general light-emitting diode is 20 mA, and the operating voltage is 2 to 3.5 volts. The operating power of a light-emitting diode is 40 to 70 milliwatts. That is, at the operating power of 40 to 70 milliwatts, the currently most efficient light-emitting diode can only produce brightness of only The spectrum of 1 ~ 5 lumens (1 ume η). Generally, the luminosity required for lighting is about several thousand lumens. Therefore, hundreds of light-emitting diodes need to be assembled to meet the requirements of lighting. This is caused by large cost or volume.

Page 4 506145 V. Description of the invention (2) The small point of view is that it cannot meet the actual requirements. Increasing the operating current of the light emitting diode is one of the methods to solve its brightness problem. For example, if the operating current of the light emitting diode can be increased to 100 mA, its brightness can also be increased by 5 times. In this way, the number of light-emitting diodes required to produce the same brightness is only one-fifth of the original. However, the current light-emitting diode (its structure is shown in Figures 5A and 5B) under high operating current, its brightness will not increase proportionally with the increase of operating current, and its service life will be affected. As shown in FIG. 5B, the base substrate of the conventional light-emitting diode is usually made of a material such as a PC board or alumina ceramic, and the material of these base substrates has poor thermal conductivity. Traditional light-emitting diodes have high operating currents that significantly reduce their service life due to poor heat dissipation. As shown in FIG. 5A, the bracket of the conventional light-emitting diode is made of Kovar alloy or copper metal. However, the bracket is too thin and does not significantly contribute to its heat dissipation. SUMMARY OF THE INVENTION The present invention is used to increase the light output power of a conventional light emitting diode. A first object of the present invention is to provide a new light emitting diode structure for increasing its operating current. According to the above object, the present invention provides a light emitting diode having a transparent substrate cladding light emitting diode crystal grain. Wherein, a base substrate is divided into two parts by an insulating region, and the two parts are respectively connected with the light emitting diode.

Page 5 506145 V. Description of the invention (3) The positive electrode and the negative electrode of the bulk grain are connected. The base substrate is made of a substance with good electrical and thermal conductivity, and is used to conduct electric current and effectively dissipate the thermal energy generated by the light emitting diode. A second object of the present invention is to provide a new light emitting diode structure for preventing light from being lost due to absorption by the light emitting diode itself, so as to achieve the purpose of increasing light output power. The present invention provides a cover substrate having a hole in the center. The flip-chip light-emitting diode grains are located in a hole in the center of the cover substrate. The cover substrate may include a white high reflectivity material, or a layer of white high reflectivity material may be coated on the inner wall of the central hole. The central hole is filled with a transparent resin, and the transparent resin forms a convex lens, and the light emitting diode die is encapsulated and covered. In order for those skilled in the art to understand the purpose, characteristics and effects of the present invention, the following specific embodiments are described in conjunction with the accompanying drawings to explain the present invention in detail, as follows: Detailed description of the invention The first figure A cross-sectional view showing a light emitting diode according to a preferred embodiment of the present invention. The light-emitting diode includes a base substrate 11, a flip-chip type light-emitting diode μ particles 16 ′, a cover substrate 17, and a convex lens 18 made of transparent resin or epoxy resin. Among them, the base substrate 丨 has an insulating region i g, which is used to separate the base substrate 11 into two non-conducting parts.

Page 6 506145 V. Description of the invention (4) The base substrate 11 is covered by a plurality of metal layers above and below, respectively, which are respectively labeled as metal layer 12, metal layer 13, metal layer 14, metal layer 1 5 ° Among them, the 'metal layer' 2 and the metal layer 13 are in contact with the n-pole of the flip-chip light-emitting diode crystal of the transparent substrate, respectively, and the metal layer 4 and the metal layer 15 are connected to an external circuit. The base substrate, in addition to fixing the light emitting diode die i 6 ′, also has a function of conducting current and assisting the light emitting diode die 16 to dissipate heat. Therefore, the material used for the base substrate 11 must have high electrical conductivity and high thermal conductivity. The thermal conductivity of metallic copper is 398 (W / m-K), and its electrical conductivity is very good ', so it is one of the most suitable materials for the base substrate 11. The thermal conductivity of metallic aluminum is 240 (W / m-K), which is also one of the most suitable materials for the base substrate 11. Although the thermal conductivity of silicon is only about one third of that of metallic copper, it is also one of the more suitable materials for the base substrate 11 because it is easy to prepare. The second figure shows the structure of a flip-chip light emitting diode crystal with a transparent substrate. The light-emitting diode grain shown in Fig. 2 is a nitrided steel gallium light-emitting diode that can emit blue light. The light-emitting diode die includes a sapphire substrate 31, a gallium nitride buffer layer 3, an n-type gallium nitride layer 3, an indium gallium nitride active layer 3, and a p-type nitride. Gallium layer 3 5. The indium gallium nitride active layer 3 4 is a light emitting layer of a light emitting diode. In this embodiment, the indium gallium nitride active layer 34 may also be an aluminum gallium indium nitride active layer. A p-type electrode layer 36 is connected below the P-type gallium nitride layer 35. An n-type electrode layer 37 is connected below the n-type nitrided chain layer 3 3. Among them, the area of the n-type electrode layer y is relatively small, and only a part of the n-type gallium nitride layer is contacted. The area of the p-type electrode layer 36 is relatively large, and it can be connected to most p-type gallium nitride layers.

Page 7 506145 V. Description of Invention (5)-Touch. The P-type electrode layer 36 has excellent light reflectivity, and can reflect light generated by the indium gallium nitride f-type layer 34. The p-type electrode layer 36 and the n-type electrode layer 37 can be bonded to the metal layer 12 and the metal layer 丨 3 of the base substrate 11 by a conductive bonding agent such as gold or a gold-tin alloy. The cover substrate 17 can be made of a white material with high reflectivity. A hole is provided in the center of the cover substrate 17 and its size is sufficient to fit a flip-chip light-emitting diode crystal 16. Among them, the inner wall of the hole is inclined, and can reflect the lateral light emitted by the light-emitting polar crystal grains. The cover substrate 7 can also be made of a light-absorbing material. At this time, the inner wall of the hole must be coated with a white light-reflective layer with high reflectivity, which can achieve the effect of reflecting the lateral light emitted by the light-emitting diode grains. . As shown in FIG. 1, the cover substrate 7 can be bonded to the base substrate 11 through a bonding layer. The central hole of the cover substrate 7 is filled with resin or epoxy resin 18, and the light emitting diode die 6 is covered and encapsulated. The convex lens system made of transparent resin can collect the light emitted by the light-emitting diode crystal grains and make the light directional. According to the present invention, the flip-chip type light emitting diode crystal system uses a transparent substrate. The light generated by the light-emitting diode can be directly transmitted through the transparent substrate, or can be reflected by the p-type electrode layer and the inner wall of the central hole of the cover substrate, and then transmitted through the front teeth. The third figure shows the situation in which the light generated by the active layer in the above-mentioned light emitting diode passes through and reflects out of the central hole of the substrate. The above-mentioned light-emitting diode can thus reduce the proportion of its light absorbed, and greatly improve its light-emitting efficiency. The above base substrate is made of a material with very good thermal conductivity. The heat energy produced by the light emitting diode grains can be efficiently dissipated to increase the light emitting diode.

Fifth, the use of the base body of the invention description body, the diode can be the junction of the fourth grain: photodiode p-type filled η-type phosphating ohmic contact. Η-type 5 7 〇η -type 5 6 is part of the face of 5 6 with p. GaInO can be combined. Although it is used to limit the spirit and range

⑹ Shun Qiu. The distance between the decano-plate and the active luminescent layer of the present invention is equivalent to that of a winged active light-emitting layer, and the "light-emitting layer is rapidly and efficiently produced at high currents to operate under the operating current of a branch." T: 4: Another new type has a transparent substrate. Flip-chip type light-emitting diode. Its light-emitting diode system is a gallium indium emitting limit: a2!:; Chemical; 'Sapphire substrate 51,-on the gallium indium limit two, marriage active layer 53, one layer 55. s 54 η-type indium gallium phosphide or gallium aluminum phosphide = gallium indium ohmic contact layer 55 is connected with an η-type electrode ru = layer 57 and can also be used as a -light reflecting layer. P-type electricity: layer The ytterbium indium lower limiting layer 52 is connected. In this case, the Bu electrode is small and only contacts the η-type electrode layer 57 of the ρ _ -type aluminum gallium indium lower indium limiting layer 5 2. It is in contact with most of the η-type phosphorus contact layer 55. The ρ-type electrode layer and the η-type electrode layer 57 are bonded to the metal layer 12 and the metal layer 13 of the base substrate 11. The disclosure is as above, but it is not the present invention. Anyone who is familiar with this technique can make various changes and decorations without departing from the scope of the present invention. The various decorations are within the scope of the patent application attached to the present invention. 506145 V. Description of the invention (7) 1111111 Page 10 506145 Simple illustration of the diagram Simple illustration of the first diagram A cross-sectional view of a preferred embodiment of a high-brightness light-emitting diode with polar crystal grains. The second image shows a cross-sectional view of a flip-chip light-emitting diode crystal with an indium gallium nitride active layer. The third image shows light emission The light generated by the active layer in the diode is transmitted, reflected, and guided out of the hole covering the center of the substrate. The fourth figure shows a cross-sectional view of a flip-chip light-emitting diode with an aluminum gallium indium phosphide active layer. Figure 5 shows a conventional light-emitting diode structure. Figure 5B shows a cross-sectional view of the light-emitting diode grains of the traditional light-emitting diode shown in Figure 5A. Main component number 11 Base substrate 12 Metal layer 13 metal layer 14 metal layer 15 metal layer 1 6 fip ip-chiptype 1 ight emitting diode chip

506145 Brief description of drawings 17 Cover substrate 18 Convex lens 19 I Inuiating region 31 Sapphire substrate 32 GaN buffer layer 33 n-type GaN layer (n_type GaN layer) 34 inGaN active layer (inGaN active layer) 3 5 p -type GaN layer (p — type GaN layer) 3 6 p -type electrode layer (p — Type electrode) 3 7 n-type electrode 51 sapphire substrate 5 2 p-type AlGalnP lower confining layer 5 3 scales A 1 G a I η P active 1 ayer 54 n-type AlGalnP upper confining layer 55 n-type gallium indium ohmic contact layer ( n-type InGaP ohmic contact layer) 5 6 p-type electrode 5 7 n-type electrode

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Claims (1)

506145 VI. Application for patent scope 1. A light-emitting diode, comprising: a base substrate, which is made of a material with good electrical and thermal conductivity, and is divided into two non-conducting parts by a middle insulation region; A cover substrate is adhered to the base substrate, and has a hole area in the center, and the hole is surrounded by an inclined side wall; a flip-chip light emitting diode crystal is bonded to the base substrate Received in a hole in the central region, the flip-chip type light emitting diode grain has a transparent substrate; A transparent substance is filled in the hole in the central region, and the flip-chip light emitting diode is encapsulated therein. 2. The light-emitting diode according to item 1 of the scope of patent application, wherein the cover substrate is formed of a white high-reflectivity substance. 3. The light-emitting diode according to item 1 of the patent application scope, wherein the inclined sidewall is coated with a white high-reflectivity substance. 4. The light-emitting diode according to item 1 of the scope of patent application, wherein the transparent substance forms a convex lens. 5. The light-emitting diode according to item 1 of the scope of patent application, wherein the base substrate is formed of a broken material. 6. The light-emitting diode according to item 1 of the scope of patent application, wherein the base substrate is formed of a copper material. 7. The light-emitting diode according to item 1 of the scope of patent application, wherein the base substrate is formed of a material. 8. The light-emitting diode according to item 1 in the scope of the patent application, wherein the crystal of the flip-chip light-emitting diode is an aluminum gallium-indium-phosphorus indium-crystal light-emitting diode. Page 13 506145 6. Scope of patent application Grain. 9. The light-emitting diode according to item 1 of the scope of the patent application, wherein the flip-chip light-emitting diode crystal grains are a vaporized Ming Su-yin flip-chip light-emitting diode crystal. 10. The light-emitting diode according to item 1 in the scope of the patent application, wherein the flip-chip light-emitting diode grain is an indium gallium nitride flip-chip light-emitting diode. Page 14