1. Field of the Invention
The present invention relates to a light emitting diode (LED) package, and more specifically, to a LED package having a fence of a phosphor resin member and a manufacturing method thereof.
2. Discussion of the Background
Generally, an LED package has a structure in which an LED chip for generating light by p-n junction is mounted on an inner space of a package body. The package body is open in a light emission direction of the LED chip through an open portion of the package body, and the light generated from the LED chip is emitted outwards through the open portion. Further, the LED package includes a lens (specifically, a molding lens) for covering the LED chip in order to increase the light emission efficiency within a predetermined directional angle range of the light. The lens is formed to cover the open portion of the package body and to be convex from the open portion of the package body.
In case of the LED package, there has been a light loss problem that a substantial amount of the light generated from the LED chip is not emitted outwards through the lens but dissipated within the lens. Such a light loss results from the existence of the light which is not directed toward the lens covering the open portion but toward a side and/or a bottom of the package body and the light which collides with the lens and then is not emitted outwards but returns back.
Accordingly, many studies have been conventionally continued to increase the amount of the light directed toward the lens. As the results of the studies, a conventional technology in which an inner wall of a package body is slanted and the slanted inner wall is coated with a reflective material has been disclosed. Such a technology has been disclosed in Korean Patent No. 613064 filed by the applicant and then registered. According to the conventional technology, the inner wall coated with the reflective material causes the light, which is not directed toward the lens or which collides with the lens and then returns back, to be reflected, thereby contributing to reducing the light loss of the LED package more or less.
However, since the LED chip and the reflective inner wall are far away from each other and both ends of the open portion of the package body and the reflective inner wall are adjacent with each other, there is an enormous amount of light which is not under the influence of the reflective inner wall. Furthermore, in order to improve the light emission efficiency using the reflective inner wall in the conventional LED package, the reflective inner wall must be designed in an expanding manner, which may prevent a compact size and structure of the LED package.
Meanwhile, an LED package which includes a molding lens made of resin containing a powder-type phosphor material has been disclosed. When the light generated from the LED chip is emitted outwards through the molding lens, the intrinsic color of the light itself generated from the LED chip is mixed with the color generated from the phosphor material, so that the LED package makes it possible to implement the light having an adjusted light emission color (for example, white color). However, since the phosphor material is non-uniformly distributed in a broad region of the molding lens of such an LED package, it is difficult to realize homogeneous color mixing. Furthermore, there is a problem in that the phosphor material non-uniformly distributed in the molding lens may cause the light of the LED chip to be scattered.
To solve this problem, a LED package technology, in which besides the molding lens, a phosphor resin member for encapsulating the LED chip is provided in the molding lens, has been conventionally proposed. However, according to the conventional manufacturing of the LED package, it is difficult to allow the phosphor resin member to be formed in the shape of a homogeneous lens having excellent light emission efficiency. That is, when liquefied resin containing a powder-type phosphor material is dotted on the LED chip to form the phosphor resin member, it is difficult to obtain the curved surface shaped like a homogeneous lens due to the flowability of the liquefied resin. In addition, when an enormous amount of LED packages is manufactured, there is a limitation in that the homogeneous lens-shaped phosphor resin member having no chromatic aberration is repeatedly reproduced.
USPTO Backgrounds
USPTO Backgrounds