Side view light emitting diode package

Abstract

A side view LED package for a backlight unit includes a package body having a cavity with an inclined inner sidewall, first and second lead frames arranged in the package body, the cavity of the package body exposing a portion of at least one of the first and second lead frames placed in a bottom of the cavity to outside, a light emitting diode chip mounted on the bottom of the cavity to be electrically connected to the first and second lead frames, and a transparent encapsulant arranged in the cavity surrounding the light emitting diode chip. The cavity has a depth larger than a mounting height of the light emitting diode chip and not exceeding six times of the mounting height. The height of the sidewall is shortened to improve beam angle characteristics of emission light, increase light quantity, and prevent a molding defect of the sidewall.

Description

CLAIM OF PRIORITY[0001]This application claims the benefit of Korean Patent Application No. 2005-113834 filed on Nov. 25, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a high power Light Emitting Diode (LED) package, particularly, in which the height of a sidewall is shortened to improve beam angle characteristics of emission light, increase light quantity, and prevent a molding defect of the sidewall.[0004]2. Description of the Related Art[0005]A Liquid Crystal Display (LCD) does not have a light source of its own, and thus requires an external illumination, which is generally referred to as a backlight unit. The backlight unit illuminates the LCD from the back and uses a Cold Cathode Fluorescent Lamp (CCFL) or an LED as a light source.[0006]FIGS. 1 and 2 show a general backlight unit 1 in use for the LCD. Referring to FIGS...

AI Technical Summary

Benefits of technology

The present invention provides a side view LED package with improved beam angle characteristics, increased light quantity, and prevention of molding defects of the sidewall. The package includes a package body with a cavity, first and second lead frames, a light emitting diode chip, and a transparent encapsulant. The cavity has a depth that is larger than the mounting height of the chip and does not exceed six times the mounting height. The invention also includes an approach to reduce the height of the wires and design a cavity suitably for the filling process of transparent and encapsulating liquid resin. The technical effects of the invention include improved beam angle characteristics, increased light quantity, and prevention of molding defects of the sidewall.

Problems solved by technology

First, this restricts the beam angle α of the light emitted out of the LED package 10. When the beam angle α is smaller, the backlight unit 1 should use the more LED packages 10.

Second, as can be seen from FIG. 5, when light beams L generated from the LED chip 12 are emitted in the direction of arrow A, a partial light beam L1 collides against a sidewall 17 of the LED package 10. When collided against the side wall 17, the light beam 17 is lost due to for example absorption / scattering. This reduces the entire light quantity emitted out of the LED package 10. The light quantity decreases more when the sidewall 17 is higher, that is, the cavity depth d in FIG. 4 is larger.

Third, the higher sidewall 17 may cause more easily a molding defect such as a void in an upper or lower portion of the sidewall 17. This may take place particularly in a portion designated with the reference sign I in FIG. 3. With the molding defect, the LED package 10 is degraded in performance, and sometimes, should be discarded.

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