JP2002232014A - Light emitting diode lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting diode lamp which is easy to see even in the open, etc., by enlarging the contrast ratio of the ray from a light emitting diode chip to the outside ray such as sunrays, etc., by simple method. SOLUTION: This light emitting diode lamp is equipped with a light emitting diode chip 100A (refer to figure 3), a lead frame 200A to which this light emitting diode chip 100A is bonded, and mold resin 300A which molds the above light emitting diode chip 100A, and a black coloring agent 400A is mixed in the above molding resin 300A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a light emitting diode lamp.

[0002]

2. Description of the Related Art A conventional light emitting diode lamp C of this kind
As shown in FIG. 3, the LED includes a light emitting diode chip (not shown), a lead frame 200C to which the light emitting diode chip is bonded, and a transparent molding resin 300C for molding the light emitting diode chip.

The lead frame 200C includes a die bonding lead 210C having a substantially mortar-shaped cup portion 230C formed at the tip, and a wire bonding lead 22 adjacent to the die bonding lead 210C.
0C. The light emitting diode chip is die-bonded to the bottom of the cup 230C,
It is electrically connected to the wire bonding lead 220C by a bonding wire (not shown). The die bonding is performed with an opaque conductive adhesive such as a silver paste or a transparent adhesive.

[0004] The cup 230C is for efficiently reflecting the light L2 emitted from the light emitting diode chip to the outside, and is mirror-finished to improve the reflection efficiency.

The light-emitting diode lamps C are used, for example, in a display device which is arranged in a matrix and used outdoors. In this case, sunlight enters the light emitting diode lamp C and is reflected by the lead frame 200C in the mold resin 300C, particularly the cup portion 230C that has been subjected to mirror finishing, so that the light L2 from the light emitting diode chip and
In some cases, the contrast ratio between the reflected light of the external light L1 such as sunlight and the like becomes small, and it is difficult to distinguish between lighting and non-lighting. In order to solve such a problem, an eave is provided for each row of the light emitting diode lamp C, so that sunlight is not directly incident. Further, instead of providing the eaves, a light shielding film is provided on the surface of the mold resin of the light emitting diode lamp. The attachment of the light shielding film is performed after the manufacture of the light emitting diode lamp. Also, a light shielding film is provided inside the mold resin 300C instead of the surface thereof.

[0006]

However, the structure in which the eaves are provided for each row of the light-emitting diode lamps has a problem that the eaves interfere with the appearance of the display device. Also, the eaves themselves must be adapted to the installation location of the display device. In addition, when the light-shielding film is provided on the surface of the mold resin, the light-shielding film protrudes from the light-emitting diode lamp and becomes large. is there. In addition, there is some concern about the peeling of the light-shielding film and the bonding strength with the mold resin. Furthermore, in the method of providing a light-shielding film inside the mold resin, the above-described problem of difficulty in close arrangement does not occur, but there is a problem that the manufacturing process of the light-emitting diode lamp is complicated. Further, in this method, there is also a problem of accuracy of the position of the light shielding film provided inside the mold resin.

The present invention has been made in view of the above circumstances, and increases the contrast ratio between light from a light emitting diode chip and external light, such as sunlight, by a simpler method than in the past, so that it can be used outdoors. It is intended to provide a light-emitting diode lamp that is easy to see.

[0008]

According to the present invention, there is provided a light emitting diode lamp, comprising: a light emitting diode chip; a lead frame to which the light emitting diode chip is bonded;
A molding resin for molding the light emitting diode chip, wherein a black coloring agent is mixed in the molding resin.

A light emitting diode lamp according to another aspect of the present invention includes a light emitting diode chip, a lead frame to which the light emitting diode chip is bonded, and a molding resin for molding the light emitting diode chip. Two or more colorants are mixed in the resin.

[0010]

FIG. 1 is a schematic sectional view of a light emitting diode lamp according to an embodiment of the present invention, and FIG. 2 is a schematic sectional view of a light emitting diode lamp according to another embodiment of the present invention. .

A light emitting diode lamp A according to an embodiment of the present invention includes a light emitting diode chip 100A, a lead frame 200A to which the light emitting diode chip 100A is bonded, and a light emitting diode chip 10A.
A molding resin 300A that molds the black colorant 40A.
OA is mixed.

In the light emitting diode chip 100A, one electrode is formed on each of the front side and the back side. By supplying a current between the electrodes, the light emitting diode chip 100A emits light.

The lead frame 200A includes a die bonding lead 210A having a substantially mortar-shaped cup portion 230A formed at the tip, and a wire bonding lead 22 adjacent to the die bonding lead 210A.
0A. The cup portion 230A includes a flat bottom portion 231A to which the light emitting diode chip 100A is die-bonded, and a tapered portion 232A whose diameter is increased from the bottom portion 231A, and is formed in a substantially mortar shape as a whole. This cup portion 230A is formed of a die having a projection having a tip corresponding to the cup portion 230A.

A conductive adhesive 170A such as a silver paste is provided on the bottom 231A of the cup 230A thus configured.
Then, the light emitting diode chip 100A is die-bonded. Thus, the electrode formed on the back surface of the light emitting diode chip 100A is electrically connected to the die bonding lead 210A.

The electrodes formed on the surface of the light emitting diode chip 100A are connected to the wire bonding leads 210A by bonding wires (not shown) such as gold wires.

As described above, the light emitting diode chip 100A
Bonding die 210 to which is bonded
The tip of A, that is, the tip of the cup 230A and the tip of the wire bonding lead 220A, are placed in a mold having a shell-shaped concave portion, and molded with a mold resin 300A that is a transparent resin such as an epoxy resin. A black colorant 400A, for example, carbon powder, is uniformly mixed into the mold resin 300A.

Then, temporary curing is performed for 1 hour in an atmosphere of 120 ° C. in a curing furnace. When the composition is cured, it is removed from the mold and fully cured for about 4 hours in an atmosphere of 135 ° C. Thus, the light emitting diode lamp A is completed. In addition, this curing condition is an example.

In the light emitting diode lamp A thus configured, if the attenuation rate of the black colorant 400A mixed in the mold resin 300A is 25%, the external light L1 such as sunlight is emitted from the light emitting diode lamp A. Is the rate of emission after entering into (100−25) × (100−25)
= 56 (%). On the other hand, the light emitting diode chip 10
The rate at which light L2 emitted from OA is radiated to the outside is 1
Since 00−25 = 75 (%), the contrast is improved.

In the above embodiment, one electrode is formed on each of the front and back surfaces of the light emitting diode chip 100A. However, two electrodes are formed on the front surface. You may. However, in that case, two wire bonding leads are required in addition to the die bonding leads.

A light emitting diode lamp B according to another embodiment of the present invention has a black colorant 40 as shown in FIG.
0A, not 2 kinds of colorant, mold resin 300B
Is mixed. The two types of colorants 410B and 42
OB is black when mixed. Needless to say, three or more types of colorants that become black when mixed may be used.

[0021]

The light emitting diode lamp according to the present invention is
A light emitting diode chip, a lead frame to which the light emitting diode chip is bonded, and a molding resin for molding the light emitting diode chip are provided, and a black coloring agent is mixed in the molding resin.

For this reason, although the light transmittance of the mold resin decreases, external light such as sunlight passes through the mold resin twice, ie, incident on the mold resin and emission from the mold resin twice. Since the light from the light emitting diode chip passes through the molding resin only once, the contrast ratio between the light from the light emitting diode chip and the external light is larger than when the black coloring agent is not mixed in the molding resin. Therefore, even in the outdoors where external light such as sunlight is incident on the light emitting diode lamp, light from the light emitting diode chip can be easily recognized simply by mixing the black colorant with the mold resin. This makes it easier to confirm the light from the light emitting diode chip than a conventional eaves or light shielding film.

Another light emitting diode lamp according to the present invention includes a light emitting diode chip, a lead frame to which the light emitting diode chip is bonded, and a molding resin for molding the light emitting diode chip. Two or more colorants are mixed in the resin.

For this reason, according to this light emitting diode lamp, black can be obtained by mixing two or more types of coloring agents, and the degree of black can be adjusted by the type and mixing ratio of the coloring agents used. Therefore, the contrast ratio can be easily adjusted.

[Brief description of the drawings]

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

FIG. 2 is a schematic sectional view of a light emitting diode lamp according to another embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view showing a problem of a conventional light emitting diode lamp.

[Explanation of symbols]

 100A LED chip 200A Lead frame 300A Mold resin 400A Colorant

Claims (2)

[Claims] A light emitting diode chip; a lead frame to which the light emitting diode chip is bonded;
A light emitting diode lamp; and a molding resin for molding the light emitting diode chip, wherein a black coloring agent is mixed in the molding resin. 2. A light emitting diode chip, and a lead frame to which the light emitting diode chip is bonded,
A light emitting diode lamp, comprising: a molding resin for molding the light emitting diode chip, wherein two or more types of coloring agents are mixed in the molding resin.