CN102479909B - Light emitting diode - Google Patents

Abstract

A light-emitting diode, including a base, a first pin and a second pin on the mounting base, and a light-emitting chip electrically connected to the first pin and the second pin, the base includes a base and is formed on the base An annular reflective cup on the base, the light-emitting chip is arranged on the surface of the base, the inner wall of the reflective cup surrounds the light-emitting chip, and the inner wall of the reflective cup is covered with a protective film. Since the light-emitting diode adopts a protective film to protect the reflective cup of the base, the reflective cup is not affected by the light-emitting chip, so problems such as yellowing and embrittlement caused by light irradiation on the reflective cup can be prevented.

Description

led

technical field

The invention relates to a semiconductor element, in particular to a light emitting diode.

Background technique

Light-emitting diodes have been used in more and more occasions due to their advantages of high light efficiency, low energy consumption, and no pollution, and have a tendency to replace traditional light sources.

Light-emitting diodes emit light by exciting their light-emitting chips with electric current. According to the selected materials, the chip of the light-emitting diode can radiate various corresponding visible and invisible light, covering the range from ultraviolet to infrared. For ultraviolet light-emitting chips, it can be used with RGB (red, green and blue) three-color phosphors to synthesize white light for lighting, and can also be used alone to achieve sterilization, purification, detection, curing and other purposes.

The LED base is usually made of synthetic polymer materials such as PPA (polypropylene adipate) or PMMA (polymethyl methacrylate), which is low in manufacturing cost and easy to shape. However, these materials are less resistant to certain light, and are prone to yellowing or even brittle cracking after long-term exposure, resulting in a reduction in the service life of the LED.

Contents of the invention

Therefore, it is necessary to provide a light-emitting diode that is not prone to yellowing and brittleness.

A light-emitting diode, including a base, a first pin and a second pin on the mounting base, and a light-emitting chip electrically connected to the first pin and the second pin, the base includes a base and is formed on the base An annular reflective cup on the base, the light-emitting chip is arranged on the surface of the base, the inner wall of the reflective cup is arranged around the light-emitting chip, and the inner wall of the reflective cup is covered with a protective film.

Since the light-emitting diode adopts a protective film to protect the reflective cup of the base, the reflective cup can not be affected by the light-emitting chip, so the problems of yellowing and embrittlement caused by light irradiation on the reflective cup can be prevented.

The present invention will be further described below in conjunction with specific embodiments with reference to the accompanying drawings.

Description of drawings

FIG. 1 is a schematic cross-sectional view of a light emitting diode according to an embodiment of the present invention.

Description of main component symbols

pedestal 10 base 11 reflective cup 12 first pin 20 2nd pin 30 Wiring section 22, 32 contact section 24, 34 Connection section 26, 36 Light emitting chip 40 Gold Line 42 protective film 50 The first protective film 51 Second protective film 52 package body 60 Phosphor particles 70 reflective particles 80

Detailed ways

Please refer to FIG. 1 , which shows a light emitting diode according to an embodiment of the present invention. The light-emitting diode includes a base 10, a first pin 20 and a second pin 30 respectively fixed on opposite ends of the base 10, a light-emitting chip 40 mounted on the first pin 20, and a protective cover covering the inner surface of the base 10. The film 50 and the package body 60 covering the light emitting chip 40 .

The base 10 includes a base 11 and a reflection cup 12 formed on the base 11 . The reflecting cup 12 is annular, and a recess (not shown) is formed in the middle thereof. Both the first pin 20 and the second pin 30 are made of metal material, bent into a U-shape, and respectively passed through opposite ends of the base 11 of the base 10 . The first pin 20 and the second pin 30 are separated from each other to avoid short circuit. Both the first pin 20 and the second pin 30 include contact sections 24, 34 located on the bottom surface of the base 11, wiring sections 22, 32 located on the top surface of the base 11 and exposed in the recess, and connecting contact sections 24, 34 and wiring sections. 22,32 connecting sections 26,36. The contact sections 24, 34 are used to connect with an external circuit (not shown) to input electric energy into the LED. The wiring segments 22 and 32 are used to electrically connect with the light emitting chip 40 to drive the light emitting chip 40 to emit light. The connection section 22 , 32 is parallel to the contact section 24 , 34 and perpendicular to the connection section 26 , 36 . The base 10 can be integrally made of LCP (Liquid Crystal Polymer, i.e. liquid crystal polymer) material, and can also be manufactured separately for different materials, such as the reflection cup 12 of the base 10 is made of LCP material, and the base 11 It is a silicon substrate, a plastic substrate or a ceramic substrate. In addition, during production, the LCP material may be mixed with plastic (Plastic) particles, ceramic (Ceramic) particles or a highly volatile solution.

The above-mentioned light-emitting chip 40 is accommodated in the reflective cup 12 of the base 10, and fixed on the surface of the connection section 22 of the first pin 20, which is made of semiconductor compound materials such as gallium nitride and indium gallium nitride. become. The light emitting chip 40 can emit various visible light or invisible light after being powered on, such as yellow light, blue light and ultraviolet light. The light-emitting chip 40 is respectively connected to the connection sections 22 and 32 of the first pin 20 and the second pin 30 through two gold wires 42 to achieve electrical conduction. Of course, the light-emitting chip 40 can also be directly fixed on the surface of the connection segments 22 and 32 of the first pin 20 and the second pin 30 in a flip-chip manner, without using the gold wire 42 .

The protective film 50 includes a first protective film 51 covering the inner wall surface of the reflection cup 12 , and a second protective film 52 attached on the top surface of the base 11 . The first protective film 51 covers the entire inner wall surface of the reflective cup 12 . The second protective film 52 is arranged around the light-emitting chip 40 and extends from the surface of the first pin 20 to the surface of the second pin 30 to cover the exposed between the first pin 20 and the second pin 30 base 11 top surface. The protective film 50 is a reflective film, which is preferably made of titanium dioxide, and can also be made of glass or ceramic materials such as silicon dioxide and silicon nitride. In this embodiment, the protective film 50 covers the surface of the base 10 that is directly exposed to the irradiation range of the light-emitting chip 40 correspondingly. In other embodiments, it can be understood that, according to specific circumstances, the protective film 50 may only include the first protective film 51 covering the inner side wall of the reflective cup 12, or only include the first protective film 51 attached to the top surface of the base 11. The second protective film 52. Through the reflection of the protective film 50 , the light emitted by the light-emitting chip 40 toward the base 10 can be effectively reflected and finally emitted, thereby improving light utilization efficiency. Moreover, the protective film 50 made of the above materials has a high reflectivity for ultraviolet light, so it can effectively reflect the ultraviolet rays in the light emitted by the light-emitting chip 40, thereby protecting the base 10 located on the back of the reflective film 50. . In particular, when the base 10 is made of the above-mentioned LCP material, its resistance to ultraviolet light is relatively low, so the protective effect of the protective film 50 is more needed. Due to the high reflectivity of the protective film 50 (up to 99%), only a very small amount of light is transmitted through the protective film 50 to reach the surface of the base 10, thereby ensuring that the base 10 is basically not affected by light. Yellowing or brittleness. In addition, the base 10 made of LCP material has better heat resistance, which can further prolong the service life of the base 10 .

The package body 60 fills the recessed portion of the reflective cup 12 to protect the light-emitting chip 40 located in the recessed portion. The package body 60 is made of transparent materials such as polycarbonate or polymethyl methacrylate. Phosphor particles 70 may be uniformly doped in the package body 60 . The phosphor particles 70 can be made of phosphor materials such as yttrium aluminum garnet, nitride, oxynitride, silicate, etc., depending on the actual light color requirement.

In order to further improve light utilization efficiency and allow more light to irradiate phosphor particles 70 , reflective particles 80 are also doped in the package body 60 . The reflective particles 80 can be made of mica, titanium dioxide, zinc oxide and other materials with high reflectivity to light, and the particle size is between 0.1 μm and 0.3 μm. Through the reflection of the reflective particles 80 , the optical path of the light that does not pass through the phosphor particles 70 can be changed so that it has a certain probability to irradiate the phosphor particles 70 . Therefore, the light extraction efficiency of the light emitting diode is correspondingly improved.

Claims (9)

1. A light-emitting diode, comprising a base, first pins and second pins on the mounting base, and a light-emitting chip electrically connected to the first pins and the second pins, the base includes a base and forms In the annular reflective cup on the base, the light-emitting chip is arranged on the surface of the base, and the inner wall of the reflective cup is arranged around the light-emitting chip. It is characterized in that: the inner wall of the reflective cup is covered with a protective film, Another protective film is provided on the surface of the base corresponding to the light-emitting chip, and the other protective film covers the surface of the substrate exposed between the first pin and the second pin. The protective film and the other protective film will directly The surface of the base exposed to the irradiation range of the light-emitting chip is correspondingly covered, and the protective film and the other protective film are reflective films. 2. The light-emitting diode according to claim 1, wherein the other protective film is disposed around the light-emitting chip. 3. The light emitting diode according to claim 2, characterized in that: the first pin and the second pin are spaced apart. 4. The light emitting diode according to claim 1, further comprising a packaging body covering the light emitting chip, and the packaging body is filled in the reflective cup. 5. The light emitting diode according to claim 4, characterized in that phosphor particles are doped in the package. 6 . The light emitting diode according to claim 4 , wherein reflective particles are doped in the package, and the reflective particles are made of titanium dioxide, mica or zinc oxide. 7. The light emitting diode as claimed in claim 1, wherein the protective film and another protective film are made of titanium dioxide. 8. The light emitting diode according to any one of claims 1 to 7, characterized in that the base is integrally made of liquid crystal polymer material. 9. The light emitting diode according to any one of claims 1 to 7, characterized in that: the reflective cup is integrally made of liquid crystal polymer material.