WO2007013774A1

WO2007013774A1 - Light emitting device package structure, method of manufacturing the light emitting device package structure, and method of manufacturing light emitting device adopting the same

Info

Publication number: WO2007013774A1
Application number: PCT/KR2006/002970
Authority: WO
Inventors: Byoung Jae Park; Yong Ho Jung; Jin Yeol Yoo
Original assignee: Sailux, Inc.; Gold Mountain Electronics Co., Ltd.
Priority date: 2005-07-28
Filing date: 2006-07-28
Publication date: 2007-02-01
Also published as: KR100628987B1

Abstract

Provided are a light emitting device package structure, a method of manufacturing the light emitting device package structure, and a method of manufacturing a light emitting device adopting the same. The light emitting device package structure includes first and second plate-shaped auxiliary support pieces each having a first thickness; a heat-dissipating portion used to mount a light emitting device chip and formed upwardly higher than the first and second auxiliary support pieces at the center of the first and second auxiliary support pieces; a plurality of auxiliary leads having the same thicknesses as the auxiliary support pieces, connected between each of the auxiliary support pieces and a side surface of the heat-dissipating portion, and each having a first bent portion formed therebetween; and main leads having the same thicknesses as the auxiliary support pieces, extending in parallel with the auxiliary leads to be spaced apart from the heat-dissipating portion, the main leads each having a second bent portion that is extended from the auxiliary support pieces toward the heat-dissipating portion, wherein the heat-dissipating portion, the auxiliary support pieces and the main leads are integrally formed of a conductive metallic material. According to the light emitting device package structure and the manufacturing method thereof, a metal plate whose central part is thicker than its peripheral part is integrally formed with a heat-dissipating portion through perforating or bending, followed by molding and cutting process to form connection leads thereby facilitating and simplifying the manufacturing process.

Description

LIGHT EMITTING DEVICE PACKAGE STRUCTURE, METHOD OF MANUFACTURING THE LIGHT EMITTING DEVICE PACKAGE STRUCTURE, AND METHOD OF MANUFACTURING LIGHT EMITTING DEVICE ADOPTING THE

SAME

Technical Field

[1] The present invention relates to a light emitting device package structure, a method of manufacturing the light emitting device package structure, and a method of manufacturing a light emitting device adopting the same, and more particularly, to a light emitting device package structure which can be easily manufactured and has a heat- dissipating structure suitable for high-output applications, a method of manufacturing the light emitting device package structure, and a method of manufacturing a light emitting device adopting the same. Background Art

[2] With the recent introduction of a structure capable of creating and radiating white light using fluorescent substance, the application range of a light emitting diode ("LED") has been extended to the field of illumination capable of substituting for conventional lighting, let alone a simple light-emitting display function. Thus, research has been steadily undertaken on an LED for high-output applications such as lighting.

[3] As the temperature increases over rated operating temperature, the life span and light emitting efficiency of an LED, which is one of semiconductor devices, are reduced. As a result, to improve the output of the LED, there is a need for a heat- dissipating structure capable of operating at as low an operating temperature as possible by effectively dissipating heat generated in the LED.

[4] However, a conventional LED is constructed such that a plate-shaped lead frame has an LED chip mounted thereon. Since heat dissipation is made through the lead frame, the conventional LED has poor heat-dissipation capability and is thus difficult to apply to high-output applications.

[5] To address these problems, development of a variety of LED package structures having a large heat-dissipation plate is under way. However, most of known LED package structures are constructed such that a heat-dissipation plate and a lead frame are separately formed and then assembled to each other, resulting in complexity in the manufacturing process.

Disclosure of Invention Technical Problem

[6] To solve the above problems, the present invention provides a light emitting device package structure that is easy to manufacture while improving heat-dissipation capability, a method of manufacturing the light emitting device package structure, and a method of manufacturing a light emitting device adopting the same. Technical Solution

[7] According to an aspect of the present invention, there is provided a light emitting device package structure comprising: first and second plate-shaped auxiliary support pieces each having a first thickness; a heat-dissipating portion used to mount a light emitting device chip and formed upwardly higher than the first and second auxiliary support pieces at the center of the first and second auxiliary support pieces; a plurality of auxiliary leads having the same thicknesses as the auxiliary support pieces, connected between each of the auxiliary support pieces and a side surface of the heat- dissipating portion, and each having a first bent portion formed therebetween; and main leads having the same thicknesses as the auxiliary support pieces, extending in parallel with the auxiliary leads to be spaced apart from the heat-dissipating portion, the main leads each having a second bent portion that is extended from the auxiliary support pieces toward the heat-dissipating portion, wherein the heat-dissipating portion, the auxiliary support pieces and the main leads are integrally formed of a conductive metallic material.

[8] Preferably, the bottom surface of the heat-dissipating portion and the bottom surface of the auxiliary support pieces are parallel with each other, and the second bent portion is constructed to have a vertical portion and a second horizontal portion, the vertical portion being bent to a predetermined length upward at an end of a first horizontal portion that is extended by predetermined distance from each of the auxiliary support pieces toward the heat-dissipating portion, and the second horizontal portion being horizontally bent from the top end of the vertical portion toward the heat- dissipating portion.

[9] The light emitting device package structure may further comprise a chip mounting portion whose inner diameter gradually decreases toward a lower position at the center of the heat-dissipating portion to mount the LED chip.

[10] More preferably, the light emitting device package structure further comprises a molding cap including portions of the auxiliary leads and the main leads in view of the heat-dissipating portion, the molding cap formed through molding such that the bottom surface of the heat-dissipating portion, the top surface of the second horizontal portion of each of the main leads, the chip mounting portion, and the bottom surface of the first horizontal portion are exposed outside. [11] According to another aspect of the present invention, there is provided a method of manufacturing a light emitting device package structure, the method comprising: forming auxiliary leads and main leads by performing a perforating process on a base frame having a base portion with a first thickness and a heat-dissipating portion formed a predetermined length higher than the base portion at the center of the base portion, the perforating process performed on the base portion of the base frame, the auxiliary leads connected between either end of the base portion and the heat-dissipating portion, and the main leads each having one end isolated from the heat-dissipating portion and the other end connected to the end of the base portion; and forming a first bent portion and a second bent portion, the first bent portion formed by bending the auxiliary leads upwardly by a predetermined length so as to protrude in a height length of the heat-dissipating portion, and the second bent portion formed such that there are provided a vertical portion formed by bending the main leads upwardly at a position spaced apart a predetermined distance from the end of the base portion toward the heat-dissipating portion and a second horizontal portion that is horizontally bent at the upper end of the vertical portion toward the heat-dissipating portion.

[12] In addition, the method may further comprise forming a molding cap including a portion of the heat-dissipating portion and portions of the auxiliary leads, the molding cap formed through molding such that the second horizontal portion, and the chip mounting portion are exposed outside, and forming cutting the main leads and the auxiliary leads exposed outside from the molding cap.

[13] According to still another aspect of the present invention, there is provided a method of manufacturing a light emitting device, the method comprising: forming auxiliary leads and main leads by performing a perforating process on a base frame having a base portion with a first thickness and a heat-dissipating portion formed a predetermined length higher than the base portion at the center of the base portion, the heat-dissipating portion having a chip mounting portion formed at the center of its top surface, the perforating process performed on the base portion of the base frame, the auxiliary leads connected between either end of the base portion and the heat- dissipating portion, and the main leads each having one end isolated from the heat- dissipating portion and the other end connected to the end of the base portion; forming a first bent portion and a second bent portion, the first bent portion formed by bending the auxiliary leads upwardly by a predetermined length so as to protrude in a height length of the heat-dissipating portion, and the second bent portion formed such that there is provided a vertical portion formed by bending the main leads upwardly at a position spaced apart a predetermined distance from the end of the base portion toward the heat-dissipating portion, and a second horizontal portion that is horizontally bent at the upper end of the vertical portion toward the heat-dissipating portion; forming a molding cap including a portion of the heat-dissipating portion and portions of the auxiliary leads, the molding cap formed through molding such that the second horizontal portion, and the chip mounting portion are exposed outside; and mounting a light emitting diode (LED) chip on the chip mounting portion and wire-bonding the LED chip and the second horizontal portion to each other.

[14] According to a further aspect of the present invention, there is provided a method of manufacturing a light emitting device, the method comprising: forming auxiliary leads and main leads by performing a perforating process on a base frame having a base portion with a first thickness and a heat-dissipating portion formed a predetermined length higher than the base portion at the center of the base portion, the heat- dissipating portion having a chip mounting portion formed at the center of its top surface, the perforating process performed on the base portion of the base frame, the auxiliary leads connected between either end of the base portion and the heat- dissipating portion, and the main leads each having one end isolated from the heat- dissipating portion and the other end connected to the end of the base portion; forming a first bent portion and a second bent portion, the first bent portion formed by bending the auxiliary leads upwardly by a predetermined length so as to protrude in a height length of the heat-dissipating portion, and the second bent portion formed such that there is provided a vertical portion formed by bending the main leads upwardly at a position spaced apart a predetermined distance from the end of the base portion toward the heat-dissipating portion, and a second horizontal portion that is horizontally bent at the upper end of the vertical portion toward the heat-dissipating portion; mounting a light emitting diode (LED) chip on the chip mounting portion and wire-bonding the LED chip and the second horizontal portion to each other; and forming a molding cap formed by molding a transparent material, including portions of the auxiliary leads and the main leads in view of the heat-dissipating portion.

Brief Description of the Drawings

[15] FIG. 1 is a perspective view of a light emitting device package structure according to an embodiment of the present invention; [16] FIG. 2 is a perspective view of a base frame for forming the light emitting device package structure shown in FIG. 1 ; [17] FIG. 3 is a plan view of a structure resulting after primarily processing the base frame shown in FIG. 2; [18] FIG. 4 is a perspective view of a light emitting device according to an embodiment of the present invention, to which a molding cap as a modified example of the light emitting device package structure of FIG. 1 is applied ; [19] FIG. 5 is a perspective view illustrating a state in which an LED chip is mounted on a light emitting device package structure according to the present invention; and

[20] FlG. 6 is a perspective view illustrating a state in which a molding cap is formed on the light emitting device package structure of FlG. 1 and a lead is then cut. Best Mode for Carrying Out the Invention

[21] Hereinafter, a light emitting device package structure which can be easily manufactured and has a heat-dissipating structure suitable for high-output applications, a method of manufacturing the light emitting device package structure, and a method of manufacturing a light emitting device adopting the same, will be described in detail with reference to the attached drawings.

[22] FlG. 1 is a perspective view of a light emitting device package structure according to an embodiment of the present invention.

[23] Referring to FlG. 1, a light emitting device package structure 100 includes a heat- dissipating portion 110, auxiliary support pieces 121a and 121b, main leads 131a and 131b, and auxiliary leads 141a and 141b.

[24] The heat-dissipating portion 110 is formed of a substantially rectangular shape and has a chip mounting portion 111 whose inner diameter gradually decreases toward a lower position at a center of the heat-dissipating portion 110. The chip mounting portion 111 is used as an area where the LED chip is mounted.

[25] A thickness of the heat-dissipating portion 110 is greater than that of the auxiliary support piece 121a, 121b and determined in consideration of heat-dissipation capability of an LED chip to which the heat-dissipating portion 110 is to be applied to.

[26] The auxiliary support piece 121a, 121b has a thickness e.g., a first thickness.

[27] The auxiliary support pieces, i.e., a first and a second auxiliary support pieces,

121a and 121b, are spaced a predetermined distance apart from the left and right side of the heat-dissipating portion 110 to support the auxiliary leads 141a and 141b and the main leads 131a and 131b. The first and second auxiliary support pieces 121a and 121b are removed together with some of the main leads 131a and 131b and the auxiliary leads 141a and 141b after forming a molding cap 310, which will later be described.

[28] The auxiliary leads 141a and 141b have the same thicknesses as the auxiliary support pieces 121a and 121b and connected between each of the auxiliary support pieces 121a and 121b and the heat-dissipating portion 110 in a strip shape.

[29] The auxiliary leads 141a and 141b have a first bent portion 142 formed therebetween to a predetermined length upward.

[30] The first bent portion 142 of the auxiliary leads 141a and 141b adjusts a gap between a second horizontal portion 134 of each of the main leads 131a and 131b and the heat-dissipating portion 110, which will later be described later. [31] The main leads 131a and 131b have the same thicknesses as the auxiliary support pieces 121a and 121b.

[32] The main leads 131a and 131b are spaced apart from the auxiliary leads 141a and

141b, and have a second bent portion that is extended from the auxiliary support pieces 121a and 121b toward the heat-dissipating portion 110.

[33] The second bent portion has a vertical portion 133 that is bent to a predetermined length upward at an end of a first horizontal portion 132 that is extended by predetermined distance from each of the auxiliary support pieces 121a and 121b toward the heat-dissipating portion 110, and the second horizontal portion 134 that is horizontally bent from the top end of the vertical portion 133 toward the heat-dissipating portion 110.

[34] Here, the top surface of the second horizontal portion 134 is used for facilitating wire-bonding and the first horizontal portion 132 or the bottom surface is used for electrical connection with external circuitry.

[35] The aforementioned light emitting device package structure 100 is preferably coated with a material having high reflectivity. Preferably, the light emitting device package structure 100 is formed of is primarily coated with a nickel (Ni) and then secondarily coated with silver on the nickel-coated layer, thereby forming a multi- coated layer.

[36] A method of manufacturing the light emitting device package structure 100 will now be described.

[37] First, a base frame 101 having such a shape as shown in FIG. 2 is prepared.

[38] The base frame 101 has a base portion 120 with a first thickness and a heat- dissipating portion 110 formed a predetermined length higher than the base portion 120 at the center of the base portion 120.

[39] The base frame 101, which has a hat-like shape, may be formed by rolling, roll forming or extruding.

[40] In addition, the base frame 101 is made of a material having superior heat and electric conductivity, e.g., copper or a copper alloy.

[41] Referring to FIG. 3, a perforating process is performed on the base frame 101 to form the above-described auxiliary support pieces 121a and 121b, the main leads 131a and 131b, and the auxiliary leads 141a and 141b. That is to say, the perforating process is performed so that an auxiliary lead formation slot 103 and a main lead isolation groove 104 are formed through the base frame 101. Then, the chip mounting portion 111 is formed at the center of the heat-dissipating portion 110.

[42] Although not shown, in order to facilitate cutting portions to be cut after forming a molding cap followed by forming the auxiliary leads 141a and 141b and the main leads 131a and 131b, cutting guide grooves may also be formed in the perforating process. [43] Then, the perforated base frame 101, as shown in FlG. 3, is constructed to have a structure shown in FlG. 1 by bending the auxiliary leads 141a and 141b and the main leads 131a and 131b. That is to say, the auxiliary leads 141a and 141b are bent such that they protrude by a predetermined length in a height direction of the heat- dissipating portion 110. In addition, ends of the main leads 131a and 131b adjacent to the heat-dissipating portion 110 are bent such that there are provided a vertical portion 133 extending upwardly and a second horizontal portion 134 extending from an upper end of the first vertical portion 133 horizontally toward the heat-dissipating portion 110. Here, each of the auxiliary leads 141a and 141b has a first bent portion 142 to an appropriate height with respect to the top surface of the heat-dissipating portion 110.

[44] In order to improve reflection efficiency from light emitted from an internal surface of the LED chip to be mounted on the chip mounting portion 111 and wire-bondability, plating treatment is performed. A portion subjected to the plating treatment may include at least the chip mounting portion 111, and the main leads 131a and 131b. In consideration of working efficiency, the overall light emitting device package structure 100 formed of a metallic material, other than the molding cap, may be subjected to the plating treatment.

[45] Preferably, the light emitting device package structure 100 is primarily plated with nickel (Ni) and then secondarily plated with silver (Ag). In an alternative embodiment, the light emitting device package structure 100 may be plated only with nickel or silver.

[46] After or before mounting the LED chip on the light emitting device package structure 100, a portion indicated by a dotted line shown in FIG. 1 is molded using a resin to form the molding cap 310, the auxiliary leads 141a and 141b and the main leads 131a and 131b, which are exposed outside from the molding cap 310, are cut in an appropriate length, thereby completing the light emitting device, which will now be described in more detail.

[47] As a first method, a LED chip (not shown) is mounted on the chip mounting portion

111 and the second horizontal portion 134 and the LED chip are wire-bonded, followed by molding using a transparent resin such that the portion indicated by a dotted line shown in FIG. 1 forms an outline and cutting the auxiliary leads 141a and 141b and the main leads 131a and 131b.

[48] Here, the molding cap 310 formed by molding may have a planar top surface. Alternatively, as shown in FlG. 4, a molding cap 330 may be provided, the molding cap 330 including a lens 332 having a convexly projecting portion corresponding to the chip mounting portion 111. In preferred embodiments, the molding caps 310 and 330 may be formed a predetermined length higher than the heat-dissipating portion 110 from the top surface of a base portion (120 of FlG. 2), so that the bottoms of the main leads 131a and 131b and the heat-dissipating portion 110 are exposed outside. While the illustrated example has shown that the auxiliary leads 141a and 141b are cut so as to protrude from the molding cap 330, the invention is not limited thereto and the auxiliary leads 141a and 141b may be cut so as not to protrude from the molding cap 330.

[49] In the meanwhile, in a case where a fluorescent substance is employed to the LED package structure according to the present invention, after mounting and wire-bonding the LED chip, the fluorescent substance is applied to the LED chip to surround the same and the molding cap 310, 330 made of a transparent resin is then formed.

[50] Alternatively, as a second method, as shown in FIG. 5, a molding cap 340 having a receiving groove 342 is formed by molding such that a portion including the second horizontal portion 134 of each of the main leads 131a and 131b and the chip mounting portion 111 is exposed. A LED chip 400 is mounted on the chip mounting portion 111 and the second horizontal portion 134 of each of the main leads 131a and 131b and the LED chip 400 are wire-bonded to each other. In this case, to enhance the surface reflectivity, the molding cap 340 is preferably made of a white resin.

[51] After forming the molding cap 340, the LED chip 400 is hermetically sealed by filling the receiving groove 342 of the molding cap 340 with a transparent material or additionally providing a lens-shaped auxiliary cap (not shown). Before or after forming the auxiliary cap, the main leads 131a and 131b and the auxiliary leads 141a and 141b are cut.

[52] In the meanwhile, in a case where a fluorescent substance is employed to the LED package structure according to the present invention, after mounting and wire-bonding the LED chip, the fluorescent substance is applied to the LED chip to surround the same and the receiving groove 342 of the molding cap 340 is then filled with the auxiliary cap made of a transparent resin.

[53] Reference numeral 345 denotes a marking chamfer portion for indicating polarity of each of the main leads 131a and 131b.

[54] Referring to FIG. 6, unlike in the foregoing discussion, after forming the molding cap 340, the main leads 131a and 131b and the auxiliary leads 141a and 141b are first cut, followed by chip mounting and forming the auxiliary cap.

[55] As described above, according to the light emitting device package structure of the present invention and the manufacturing method thereof, a metal plate whose central part is thicker than its peripheral part is integrally formed with a heat-dissipating portion through perforating or bending, followed by molding and cutting process to form connection leads thereby facilitating and simplifying the manufacturing process.

Claims

[1] A light emitting device package structure comprising: first and second plate-shaped auxiliary support pieces each having a first thickness; a heat-dissipating portion used to mount a light emitting device chip and formed upwardly higher than the first and second auxiliary support pieces at the center of the first and second auxiliary support pieces; a plurality of auxiliary leads having the same thicknesses as the auxiliary support pieces, connected between each of the auxiliary support pieces and a side surface of the heat-dissipating portion, and each having a first bent portion formed therebetween; and main leads having the same thicknesses as the auxiliary support pieces, extending in parallel with the auxiliary leads to be spaced apart from the heat- dissipating portion, the main leads each having a second bent portion that is extended from the auxiliary support pieces toward the heat-dissipating portion, wherein the heat-dissipating portion, the auxiliary support pieces and the main leads are integrally formed of a conductive metallic material.

[2] The light emitting device package structure of claim 1, wherein the bottom surface of the heat-dissipating portion and the bottom surface of the auxiliary support pieces are parallel with each other, and the second bent portion is constructed to have a vertical portion and a second horizontal portion, the vertical portion being bent to a predetermined length upward at an end of a first horizontal portion that is extended by predetermined distance from each of the auxiliary support pieces toward the heat-dissipating portion, and the second horizontal portion being horizontally bent from the top end of the vertical portion toward the heat-dissipating portion.

[3] The light emitting device package structure of claim 2, further comprising a chip mounting portion whose inner diameter gradually decreases toward a lower position at the center of the heat-dissipating portion to mount the LED chip.

[4] The light emitting device package structure of claim 3, further comprising a molding cap including portions of the auxiliary leads and the main leads in view of the heat-dissipating portion, the molding cap formed through molding such that the bottom surface of the heat-dissipating portion, the top surface of the second horizontal portion of each of the main leads, the chip mounting portion, and the bottom surface of the first horizontal portion are exposed outside.

[5] A method of manufacturing a light emitting device package structure, the method comprising: forming auxiliary leads and main leads by performing a perforating process on a base frame having a base portion with a first thickness and a heat-dissipating portion formed a predetermined length higher than the base portion at the center of the base portion, the perforating process performed on the base portion of the base frame, the auxiliary leads connected between either end of the base portion and the heat-dissipating portion, and the main leads each having one end isolated from the heat-dissipating portion and the other end connected to the end of the base portion; and forming a first bent portion and a second bent portion, the first bent portion formed by bending the auxiliary leads upwardly by a predetermined length so as to protrude in a height length of the heat-dissipating portion, and the second bent portion formed such that there are provided a vertical portion formed by bending the main leads upwardly at a position spaced apart a predetermined distance from the end of the base portion toward the heat-dissipating portion and a second horizontal portion that is horizontally bent at the upper end of the vertical portion toward the heat-dissipating portion.

[6] The method of claim 5, further comprising forming a chip mounting portion whose inner diameter gradually decreases toward a lower position at the center of the heat-dissipating portion.

[7] The method of claim 6, further comprising forming a molding cap including a p ortion of the heat-dissipating portion and portions of the main leads, the molding cap formed through molding such that the second horizontal portion, and the chip mounting portion are exposed outside.

[8] The method of claim 7, further comprising forming cutting the main leads and the auxiliary leads exposed outside from the molding cap.

[9] A method of manufacturing a light emitting device, the method comprising: forming auxiliary leads and main leads by performing a perforating process on a base frame having a base portion with a first thickness and a heat-dissipating portion formed a predetermined length higher than the base portion at the center of the base portion, the heat-dissipating portion having a chip mounting portion formed at the center of its top surface, the perforating process performed on the base portion of the base frame, the auxiliary leads connected between either end of the base portion and the heat-dissipating portion, and the main leads each having one end isolated from the heat-dissipating portion and the other end connected to the end of the base portion; forming a first bent portion and a second bent portion, the first bent portion formed by bending the auxiliary leads upwardly by a predetermined length so as to protrude in a height length of the heat-dissipating portion, and the second bent portion formed such that there is provided a vertical portion formed by bending the main leads upwardly at a position spaced apart a predetermined distance from the end of the base portion toward the heat-dissipating portion, and a second horizontal portion that is horizontally bent at the upper end of the vertical portion toward the heat-dissipating portion; forming a molding cap including a portion of the heat-dissipating portion, and portions of the main leads and the auxiliary leads, the molding cap formed through molding such that the second horizontal portion, and the chip mounting portion are exposed outside; and mounting a light emitting diode (LED) chip on the chip mounting portion and wire-bonding the LED chip and the second horizontal portion to each other. [10] A method of manufacturing a light emitting device, the method comprising: forming auxiliary leads and main leads by performing a perforating process on a base frame having a base portion with a first thickness and a heat-dissipating portion formed a predetermined length higher than the base portion at the center of the base portion, the heat-dissipating portion having a chip mounting portion formed at the center of its top surface, the perforating process performed on the base portion of the base frame, the auxiliary leads connected between either end of the base portion and the heat-dissipating portion, and the main leads each having one end isolated from the heat-dissipating portion and the other end connected to the end of the base portion; forming a first bent portion and a second bent portion, the first bent portion formed by bending the auxiliary leads upwardly by a predetermined length so as to protrude in a height length of the heat-dissipating portion, and the second bent portion formed such that there is provided a vertical portion formed by bending the main leads upwardly at a position spaced apart a predetermined distance from the end of the base portion toward the heat-dissipating portion, and a second horizontal portion that is horizontally bent at the upper end of the vertical portion toward the heat-dissipating portion; mounting a light emitting diode (LED) chip on the chip mounting portion and wire-bonding the LED chip and the second horizontal portion to each other; and forming a molding cap formed by molding a transparent material, including portions of the auxiliary leads and the main leads in view of the heat-dissipating portion.