JP2003046137A - Semiconductor light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-luminance semiconductor light emitting device in which a migration is not generated even when Ag is used for a reflecting wall. SOLUTION: A conical through hole 11 is formed in the central part of an insulating substrate 10, and a semiconductor light emitting element 13 which is continuity-mounted on a submount element 12 is inserted into the through hole 11 from the lower part. The through hole 11 has a shape expanded toward the takeout direction of light, and its inner surface is used as the reflecting wall 14 formed by an Ag plating operation. Since the reflecting wall 14 is insulated from a p-electrode 15a and an n-electrode 15b which are connected to the element 13, a voltage is not applied to the electrodes, and an Ag migration is not generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount semiconductor light emitting device, and more particularly, to a semiconductor light emitting device having a reflective wall around a semiconductor light emitting element and capable of emitting light with high brightness.

[0002]

2. Description of the Related Art A surface-mount type light emitting diode (LED) package uses a white resin, which is a material of the package, to form a reflective wall around the semiconductor light emitting element so that the semiconductor light emitting element emits light laterally. The mainstream is the one that is reflected upward by a reflecting wall. There is also a reflective wall which is plated with Au in order to improve the reflection of the reflective wall.

3 and 4 show an example of the above-mentioned conventional surface mount type LED package.

The LED package 51 shown in FIG. 3 has a semiconductor light emitting device 52 formed by forming an n-type layer and a p-type layer of a GaN-based compound semiconductor on a sapphire substrate, and a p-electrode 54a on an insulating substrate 53. And the n-electrode 54b are flip-chip mounted by a face-down method. The substrate 53 has a reflective wall 55 formed around the semiconductor light emitting element 52 in the central portion thereof, and the p electrode 54a and the n electrode 54b are patterned over almost the entire surface of the reflective wall 55, so that the horizontal direction from the semiconductor light emitting element 52 is reduced. The light emitted to is efficiently reflected upward.

In an LED package 61 shown in FIG. 4, a pattern of p electrodes 64a and n electrodes 64b is formed on an insulating substrate 63, a semiconductor light emitting element 62 is conductively mounted on the p electrode 64a, and an n electrode 64b and a wire are provided. Bonded. Also in the case of this LED package 61,
Similar to the LED package 51 shown in FIG. 3, the reflective wall 65 is formed on the substrate 63, and the p electrode 64a and the n electrode 64b are formed over almost the entire surface of the reflective wall 65 by patterning.

[0006]

As described above, the p electrode and the n electrode which are patterned on the reflection wall are conventionally formed by Au plating. However, Ag has the highest reflectance with respect to visible light, and Au has a lower reflectance than Ag. Especially for green and blue wavelengths (Table 1)
As shown in, the reflectance is extremely poor.

[0007]

[Table 1]

Therefore, it is desirable that the p-electrode and the n-electrode of the reflecting wall are made of Ag. However, when Ag is used, a voltage is applied between the p-electrode and the n-electrode.
Migration is a problem. For example, as shown in FIG. 3, since the p electrode 54a and the n electrode 54b are considerably close to each other in the semiconductor light emitting element portion, migration occurs in a short time. The same applies to the example shown in FIG. If migration occurs, insulation deterioration or short circuit will be caused, and the LED will not light and cannot be used.

Therefore, in the present invention, Ag is formed on the reflecting wall.
It is an object of the present invention to provide a high-luminance semiconductor light emitting device which does not cause migration even when used.

[0010]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a semiconductor light emitting device in which a reflective wall is formed around a semiconductor light emitting element. It is characterized in that plating is formed.

According to the present invention, even if Ag is used for the reflecting wall, migration does not occur. Therefore, Ag is used to form the reflecting wall having high reflectance, and a semiconductor light emitting device having high brightness is obtained. To be

[0012]

According to a first aspect of the present invention, in a semiconductor light emitting device in which a reflective wall is formed around a semiconductor light emitting element, the reflective wall is metal-plated by being insulated from an electrode connected to the semiconductor light emitting element. In the semiconductor light emitting device, the electrodes and the reflection wall are insulated from each other. Therefore, even if Ag is used for the reflection wall, the voltage of the electrode is not applied and migration does not occur. .

The invention according to claim 2 is the semiconductor light-emitting device according to claim 1, wherein the metal plating is Ag plating, and a reflective wall having a high reflectance can be formed by using Ag.

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows an LED package as a semiconductor light emitting device according to a first embodiment of the present invention, (a) is a plan view and (b) is a longitudinal sectional view.

Referring to FIG. 1, the LED package according to the first embodiment of the present invention includes a semiconductor light emitting element 13 which is provided with a mortar-shaped through hole 11 in the center of an insulating substrate 10 and which is conductively mounted on a submount element 12. It is inserted into the through hole 11 from below. The through hole 11 has a shape that expands upward (in the light extraction direction), and the inner surface thereof is a reflection wall 14 formed by Ag plating.

Au is provided on both left and right ends of the substrate 10, respectively.
To form the p-electrode 15a and the n-electrode 15b,
The electrode 15a and the n-electrode 15b are the submount element 12
The semiconductor light emitting device 13 is formed by the electrode pattern formed above.
Connected with. The p electrode 15a and the n electrode 15
The b and the reflection wall 14 are separated and insulated from each other as shown in FIG.

In the LED package having the above-mentioned structure, the upper side of the semiconductor light emitting element 13 is the main light extraction surface, but the light passing to the side of the semiconductor light emitting element 13 is reflected upward by the reflecting wall 14 formed of Ag. , Can be efficiently collected on the main light extraction surface side. At this time, since the reflection wall 14 is insulated from the p electrode 15a and the n electrode 15b, no voltage is applied to these electrodes,
Ag migration does not occur.

In this embodiment, the reflection wall 1
Although the shape of No. 4 has a mortar shape that expands upward, the present invention is not limited to this, and may have a quadrangular pyramid shape in which the top portion that expands upward is cut off.

(Second Embodiment) FIG. 2 shows an LED package as a semiconductor light emitting device according to a second embodiment of the present invention, (a) is a plan view and (b) is a longitudinal sectional view.

In FIG. 2, the LED package according to the second embodiment of the present invention is provided with a recess 21 having an inclined surface in the center of an insulating substrate 20, and a semiconductor light emitting element 22 is mounted in the center of the recess 21. The p electrode 23a and the n electrode 23b provided on the substrate 20 are connected by wires 24a and 24b.

The concave portion 21 is in the shape of a quadrangular pyramid with the top cut off to expand upward (light extraction direction).
Its inner surface is a reflection wall 25 formed by Ag plating. The reflection wall 25 is separated from the p electrode 23a and the n electrode 23b, and the semiconductor light emitting element 22 is a compound semiconductor layer laminated on an insulating sapphire substrate. It does not cost.

Therefore, in the LED package having the above-described structure, as in the LED package of the first embodiment, the light that escapes to the side of the semiconductor light emitting element 22 is reflected upward by the reflection wall 25 formed of Ag and efficiently. It can be collected on the light extraction surface side. In addition, the reflection wall 25
Since no voltage is applied to the electrodes, Ag migration does not occur.

[0024]

According to the present invention, migration does not occur even if Ag is used for the reflecting wall.
Is used to form a reflective wall having high reflectance, and a semiconductor light emitting device having high brightness can be obtained.

[Brief description of drawings]

FIG. 1 shows an LED package according to a first embodiment of the present invention, in which (a) is a plan view and (b) is a longitudinal sectional view.

FIG. 2 shows an LED package according to a second embodiment of the present invention, in which (a) is a plan view and (b) is a longitudinal sectional view.

FIG. 3 shows an example of a conventional surface mount type LED package, (a) is a plan view and (b) is a longitudinal sectional view.

FIG. 4 shows another example of a conventional surface mount type LED package, in which (a) is a plan view and (b) is a longitudinal sectional view.

[Explanation of symbols]

10, 20 substrate 11 through holes 12 Submount element 13,22 Semiconductor light emitting device 14,25 reflective wall 15a, 23a p electrode 15b, 23b n-electrode 21 recess 24a, 24b wire

Continued front page    (72) Inventor Masafumi Shirahama             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5F041 AA44 DA07 DA19 DA33 DA36

Claims (2)

[Claims] 1. A semiconductor light emitting device in which a reflective wall is formed around a semiconductor light emitting element, wherein a metal plating is formed on the reflective wall so as to be insulated from an electrode connected to the semiconductor light emitting element. . 2. The semiconductor light emitting device according to claim 1, wherein the metal plating is Ag plating.