JP2007300018A - LED device - Google Patents

Abstract

Provided is an LED (Light Emitting Diode) device whose luminance hardly decreases even when used for a long time.
An LED device having a lead frame, a resin cup portion, and a conical metal member disposed on an inner surface of the resin cup portion away from the lead frame.
[Selection] Figure 1

Description

    The present invention relates to an LED (Light Emitting Diode) device.

    The metal strip is subjected to multi-stage press processing while passing through a transfer press to produce the lead frame 2, and then insert molding is performed by an injection molding machine to integrally form the resin cup portion 10 on the lead frame, and then the lead frame. A conventional LED device is manufactured by cutting a part of the LED. Thereafter, the LED chip 3 is die-bonded to the chip pad portion of the lead frame, and then the electrode portion of the LED chip and the lead frame are wire-bonded with a gold wire or the like (not shown), and dehumidification or vacuum is performed as necessary. Evacuate, cover the lens (not shown), seal the top, and complete the LED device.

  FIG. 2 is a perspective view of a conventional LED device, and FIG. 3 is a cross-sectional view of the conventional LED device.

    The resin cup portion 10 is surrounded by an upper surface 10a, an inner surface 10b, a notch portion 10c, outer surfaces 10d, 10e, 10f, 10g, and a bottom surface 10h.

    Moreover, the resin cup part 10 was manufactured with white nylon-type resin. The inner side surface 10b is inclined so that the diameter near the lead frame is small and the diameter near the open end is large, but it functions as a reflection surface, and the light generated from the LED chip is reflected by the inner surface and opened. It is emitted through the end and a lens (not shown). Conventionally, a white resin is used to increase the reflectance of the reflecting surface.

    In the conventional LED device, since the reflection surface is white resin, when used for a long time, the white resin on the reflection surface gradually changes to yellow, the reflectance decreases, and the brightness as an LED device is about 50%. There is a problem that it will be lowered. In particular, in the case of a high-power LED, the color is changed to yellow when used for a relatively short period of time, and the luminance is lowered. This is thought to be because the white resin was burnt by the heat generated from the LED.

    Therefore, an object of the present invention is to provide an LED device in which the luminance hardly decreases even when used for a long time.

    The above object is achieved by the LED device according to the first aspect of the present invention, that is, the lead frame, the resin cup portion, and the conical metal member disposed on the inner surface of the resin cup portion away from the lead frame. And achieved by an LED device.

In a preferred embodiment of the present invention, as described in claim 2, the cone-shaped metal member has a bottomless truncated cone shape, and the small-diameter end of the cone-shaped metal member has a rib shape.
It is arranged on the card frame side.

    In another embodiment of the present invention, as described in claim 3, the pyramidal metal member has a rounded corner and a bottomless quadrangular frustum shape, and the small square end of the pyramidal metal member is Arranged on the lead frame side.

    In another embodiment of the present invention, as described in claim 4, the cone-shaped metal member is silver-plated on stainless steel, gold-plated aluminum alloy, silver-plated aluminum alloy, or nickel base plating. Made of copper alloy.

    In still another embodiment of the present invention, as described in claim 5, the conical metal member is formed by drawing.

    In still another embodiment of the present invention, as described in claim 6, the resin cup portion is made of a black resin.

    In still another embodiment of the present invention, as described in claim 7, the resin cup portion is made of a nylon resin, a liquid crystal polymer resin, a thermosetting resin, or a silicon resin.

    In the LED device of the present invention, since the conical metal member is used as the reflecting surface, the reflectance hardly decreases even when used for a long time, the luminance hardly deteriorates, and the heat resistance of the reflecting surface is excellent. Therefore, the luminance can be kept almost constant even when applied to a high power LED.

    Further, in the LED device of the present invention, since the conical metal member is used as the reflecting surface, the material of the resin cup portion can be freely selected, the cost is relatively reduced, and the production yield is improved. The heat resistance can be further improved.

    In addition, the color of the resin cup can be freely selected, and blackening recently required to prevent unnecessary reflection can be performed at low cost. In the case of black resin in which defective products are generated due to the mixing of (burnt resin), the product yield is not noticeable and the product yield is greatly improved.

    Furthermore, in the LED device of the present invention, since the conical metal member is used as the reflecting surface, various lights can be reflected by changing the plating attached to the inner surface of the conical metal member.

    Furthermore, in the LED device of the present invention, since the conical metal member is used as the reflecting surface and the periphery thereof is molded with resin, the metal member is difficult to peel off from the resin.

    Hereinafter, various embodiments of an LED device according to the present invention will be described with reference to the accompanying drawings.

First Embodiment FIG. 1 is a schematic view of an LED device of a first embodiment, (a) is a perspective view seen from above, (b) is a perspective view of a conical metal member, c) is a perspective view seen from below. FIG. 6 is a cross-sectional view of the LED device of the first embodiment. The lead frame 2 is made of metal, and the die pad portion 2c of the lead frame 2 is thick in order to improve heat dissipation. After the resin molding, the die pad portion 2c starts from the bottom surface 10h of the resin cup portion 10. The back surface 2d is exposed. The lead portions 2a and 2b of the lead frame 2 are arranged at a slight distance next to the die pad portion 2c. The surfaces 2s and 2s of the lead portions 2a and 2b and the surface 2s of the die pad portion 2c are located on the same plane.

    In the first embodiment, the conical metal member 1 has a conical shape, and both ends have a circular diameter. However, since the diameters are different, they are referred to as a small diameter end 1a and a large diameter end 1b. A stainless steel plate with a glossy surface finish is drawn into a cone shape. Since the inner surface 1c serves as a reflecting surface, the surface irregularities may be controlled by performing surface processing such as polishing processing, shot blasting processing, etching processing after the drawing processing, if necessary. The directivity of reflected light can be variously changed depending on the surface state. Moreover, the reflection direction of light changes by changing the inclination angle of the inner surface 1c.

    The small-diameter end 1a of the cone-shaped metal member 1 is arranged on the lead frame side, arranged slightly spaced from the surface 2s of the lead frame 2 and insert-molded, and the resin cup portion 10, the lead frame 2, and the cone shape The metal member 1 is integrally formed.

    The resin cup portion 10 is surrounded by an upper surface 10a, outer side surfaces 10g, 10f, a bottom surface 10h, and an inner side surface 10b. As the resin material, a liquid crystal polymer resin LCP is used, which is excellent in heat resistance.

    In the LED device of the first embodiment, the die pad portion 2c also serves as a thick heat radiating portion, and since it is exposed from the bottom surface 10h of the resin cup portion, the heat dissipation is excellent, so a high power of 450 to 600 mA. LEDs can be mounted. Moreover, even if a high power LED is mounted, the reflection surface is constituted by the conical metal member 1, so there is no decrease in reflectance due to heat, and the brightness of the LED device is high even when used at high power for a long time. There is no deterioration.

Second Embodiment FIG. 4 is a cross-sectional view of an LED device according to a second embodiment.
There are the following three differences from the LED device of the first embodiment.
1. The lead frame is made of phosphor bronze and is obtained by press punching a material having a uniform thickness.
2. The cone-shaped metal member is obtained by drawing a brass plate material into a conical shape, applying Ni foundation plating, and further silver-plating, and the surface is in a mirror state.
3. A black resin is used as the resin. In the LED device of the second embodiment, only the inner side surface of the cone-shaped metal member reflects the light emitted from the LED as a reflection surface, and the resin cup portion is made of black resin, so it hardly reflects light. When no light is emitted, there is an advantage that the resin cup portion is not so conspicuous because of the black color.

Third Embodiment FIG. 5 is a plan view showing a modification of the conical metal member of the third embodiment.
In FIG. 5A, the end of the cone-shaped metal member 1 ′ has a similar elliptical shape, and is designed so that the light beam spreads differently in the minor axis direction and the major axis direction.

    In FIG.5 (b), the end of the cone-shaped metal member 1 '' is a square with a similar corner.

It is the schematic of the LED device of 1st Embodiment, (a) is the perspective view seen from upper direction, (b) is the perspective view of a cone-shaped metal member, (c) is the perspective view seen from the downward direction FIG. It is a perspective view of the conventional LED device. It is sectional drawing of the conventional LED device. It is sectional drawing of the LED device of 2nd Embodiment. It is a top view which shows the example of a change of the cone-shaped metal member of 3rd Embodiment. It is sectional drawing of the LED device of 1st Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ...... Conical metal member 1 '... Conical metal member 1 "... Conical metal member 1a ... Small diameter end 1b ... Large diameter end 1c ... Inner surface 2.・ ・ ・ Lead frame 2a ・ ・ ・ Lead part 2b ・ ・ ・ Lead part 2c ・ ・ ・ Die pad part 2d ・ ・ ・ Back side 2s ・ ・ ・ Front surface 3 ・ ・ ・ LED chip 10 ・ ・ ・ Resin cup part 10a ・-Upper surface 10b-Inner surface 10c-Notch 10d-Outer surface 10e-Outer surface 10f-Outer surface 10g-Outer surface 10h-

Claims (7)

A lead frame, a resin cup part, and a conical metal member disposed on the inner surface of the resin cup part away from the lead frame;
LED device having:     The LED device according to claim 1, wherein the cone-shaped metal member has a bottomless truncated cone shape, and a small-diameter end of the cone-shaped metal member is disposed on the lead frame side.     2. The LED device according to claim 1, wherein the pyramidal metal member has a rounded truncated pyramid shape with four corners, and the small square end of the pyramidal metal member is disposed on the lead frame side.     The cone-shaped metal member is made of stainless steel, a gold-plated aluminum alloy, a silver-plated aluminum alloy, or a copper alloy silver-plated on a nickel base plating. LED device according to claim 1.     The LED device according to any one of claims 1 to 4, wherein the conical metal member is formed by drawing.     6. The LED device according to claim 1, wherein the resin cup portion is made of a black resin.     The LED device according to any one of claims 1 to 6, wherein the resin cup portion is made of a nylon resin, a liquid crystal polymer resin, a thermosetting resin, or a silicon resin.

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