JP2003152226A - Light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems that, in the conventional light emitting device using a molded three-dimensional circuit body, the bondability between a metallic layer for electrode formed on the surface of an insulating substrate and a light emitting element is poor, because the metallic layer is composed of a glossy metallic layer and, in addition, a large amount of man-hours is required when the light emitting device is protected with a transparent resin and the luminous efficiency of the device is lowered due to the leakage of emitted light. SOLUTION: The glossy metallic layer is made to satisfy both a reflection characteristic and the bondability with the light emitting element by forming the layer in the recessed section of the molded three-dimensional circuit body and a metallic layer having superior bondability on the upper surface of the metallic layer. In addition, the working on the light emitting device is facilitated and the deterioration in luminous efficiency of the device is reduced by forming a wall section which prevents the flowing out of the transparent resin in the outer peripheral section of the upper surface of the metallic plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a three-dimensional circuit molded body having an L shape.
The present invention relates to a light emitting device including a light emitting element such as an ED.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a light emitting device in which a light emitting element such as an LED or LD is mounted on a three-dimensional molded body.
The present applicant also proposed this structure in Japanese Patent Laid-Open No. 2001-36150. FIG. 6 shows the above-mentioned JP 2001-36A.
FIG. 7 is a perspective view showing a light emitting device using a three-dimensional circuit molded body according to the prior art disclosed in Japanese Patent Publication No. 150, and FIG. 7 is a sectional view thereof.

A conventional light emitting device using a molded three-dimensional circuit will be described below. 20 in FIGS. 6 and 7.
Is an insulating substrate that is a resin-molded insulating base, and a mortar-shaped recess 22 that opens to the upper surface side is provided at the central position of the upper surface portion 21 of the generally insulating substrate 20.

A cathode electrode 24 and an anode electrode 25 are formed on the upper surface 21 of the insulating substrate 20 so as to sandwich a central slit 23, and the cathode electrode 24 and the anode electrode 25 are formed on the insulating substrate 20. The bottom electrodes 24a and 25a for making external connection are integrally formed by extending to the back surface via the side surface of the. A reflective surface 26 integrally formed with the cathode electrode 24 and the anode electrode 25 is formed on the inner peripheral surface of the recess 22.
As described above, the three-dimensional circuit molded body is formed by forming each electrode made of a metal layer on the surface of the insulating substrate 20.

A light emitting diode 30 (hereinafter abbreviated as LED), which is a light emitting element, is fixed to the bottom surface of the concave portion 22 of the three-dimensional molded body by an adhesive material.
The pair of electrodes of 0 and the cathode electrode 24 and the anode electrode 25 are connected by bonding wires 31 and 32. The LED 30 and the bonding wires 31 and 32 are a transparent resin 3 which is a resin sealing body formed on the upper surface portion 21 of the insulating substrate 20 including the concave portion 22.
The light emitting device 40 is configured to be protected by 3.

The cathode electrode 24, the anode electrode 25 formed on the surface of the insulating substrate 20 and the reflection surface 26 formed on the inner peripheral surface of the recess 22 are all provided with a glossy metal layer such as gloss Ag. There is. This is in consideration of increasing the luminous efficiency of the light emitting device.

[0007]

In the conventional light emitting device 40, the metal layer formed on the surface of the insulating substrate 20 is the electrode of the LED 30 and is formed on the inner peripheral surface of the recess 22 at the same time. Since it has the function as the reflection surface 26, the function of the reflection surface is generally prioritized to form the glossy metal layer (for example, the glossy Ag layer).

However, since the glossy metal layer such as the glossy Ag layer has glossiness and is excellent in the performance as a reflection surface, on the other hand, the pair of electrodes of the LED 30 is connected by the bonding wires 31 and 32. There is a problem that the bonding property is poor at the time of soldering, and as a result, deterioration of the light emitting characteristics due to instability of electrical connection in the light emitting device after mounting has been a problem.

Further, in the light emitting device 40, a mold is used to form the transparent resin encapsulant 33, but this requires a large-scale manufacturing apparatus and the LED 30 emits light. There is a problem that the light emission efficiency decreases due to leakage of light emission from the side surface of the resin encapsulant 33 covering the upper surface portion 21 of the insulating substrate 20.

The present invention has been made in view of the above problems, and provides a light emitting device which is excellent in both reflection characteristics and bondability, is easy to process, and reduces the decrease in luminous efficiency due to leaked light. To aim.

[0011]

In order to achieve the above object, the gist of the present invention is to form a three-dimensional circuit by forming a metal layer on the surface of an insulating substrate having a recess and an upper surface around the recess. A light-emitting element is mounted in the recess of the molded body, and the light-emitting element is wire-bonded to the metal layer formed on the upper surface, and the upper surface including the inside of the recess is transparent resin. In a light-emitting device sealed by means of, a glossy metal layer forming a reflection layer is formed in the recess as the metal layer, and a metal layer having good bonding property is formed in the upper surface portion. Is characterized by.

Further, the glossy metal layer is a glossy Ag layer, and the metal layer having a good bonding property is an Au layer.

Further, a wall portion for preventing the transparent resin from flowing out is formed on an outer peripheral portion of an upper surface portion of the three-dimensional circuit molded body.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a perspective view showing a light emitting device using a three-dimensional circuit molded body according to a first embodiment of the present invention, FIG. 2 is a sectional view thereof, and elements of the light emitting device shown in FIGS. 6 and 7. The same elements will be denoted by the same reference numerals and description thereof will be omitted.

1 and 2 are different from the prior arts of FIGS. 6 and 7 in that the prior art forms a cathode electrode 24 and an anode electrode 25 formed on the surface of the insulating substrate 20.
In addition, while the reflective surface 26 formed on the inner peripheral surface of the recess 22 is formed with a glossy metal layer such as gloss Ag, in the present invention, as the metal layer, the inside of the recess 22 is not reflected. Gloss A as a glossy metal layer forming the surface 26
That is, the g layer 12 is formed, and the Au layer 11 is formed on the upper surface portion 21 as a metal layer having a good bonding property.

Further, the slit 23 is provided in the upper surface portion 21 without being provided in the center of the insulating substrate 20,
In this configuration, the slit 23 is formed so as to avoid the inner peripheral surface of the recess 22, so that the area of the reflective surface 26 formed on the inner peripheral surface of the recess 22 is increased and the reflection efficiency is improved. The one bonding wire 32 connected to the LED 30 jumps over the slit 23 and is bonded to the anode electrode 25.

According to the above structure, the light emitted from the LED 30 is efficiently reflected by the reflecting surface 26 formed by the glossy Ag layer 12 inside the recess 22, and at the same time, the bonding wire connected to the LED 30. Three
Nos. 1 and 32 are reliably bonded to the Au layer 11 having good bonding properties. Further, since the slit 23 is formed so as to avoid the inner peripheral surface of the concave portion 22, the area of the reflecting surface 26 in the concave portion 22 is increased, so that the emission efficiency can be further improved.

FIG. 3 is a cross-sectional view of a light emitting device 18 which is another embodiment of the present invention. The difference from the light emitting device 10 of FIG. 2 is that the transparent resin is formed on the outer peripheral portion of the upper surface 21 of the insulating substrate 20. Wall part 1 for preventing outflow of 33
5, the transparent resin 33 is made to flow inside the approximate wall portion 15 to protect the LED 30 and the bonding wires 31 and 32.

As a method of forming the wall portion 15, after forming an electrode film on the upper surface portion 21 of the insulating substrate 20, a heat resistant resin such as an epoxy resin is screen-printed to a thickness of 0.1 mm.
Form a wall with a height of ~ 1 mm. Since the wall portion 15 needs to have a function of preventing the flow of the transparent resin 33 and at the same time preventing light leaking to the side, it is desirable that the wall portion 15 is made of white or the like having a light shielding effect.

FIGS. 4 and 5 are sectional views of a three-dimensional circuit molded body for explaining the step of forming a metal film on the insulating substrate 20 of the present invention. FIG. 4 shows the state in which the slits 23 are provided in the insulating substrate 20 and the Au layer 11 having good bonding properties.
After forming the cathode electrode 24 and the anode electrode 25, a portion other than the concave portion 22 is covered with a resist film (not shown), and the gloss Ag layer 12 is laminated on the Au layer 11 surface of the inner peripheral surface of the concave portion 22. After the reflective surface 26 is formed by the above, the resist film is peeled off.

Further, in FIG. 5, in the state where the slits 23 are provided in the insulating substrate 20, the cathode electrode 24 and the anode electrode 25 are formed on the glossy Ag layer 12, and then the concave portion 22 is covered with a resist film. Gloss Ag except for the cover and recess 22
The Au film 11 having good bonding properties is laminated on the surface of the layer 12 and then the resist film is peeled off.

In either of the methods shown in FIGS. 4 and 5, a glossy metal layer forming the reflecting surface 26 is formed in the recess 22, and a metal layer having good bonding property is formed on the upper surface 21. Has been done. When the three-dimensional circuit molded body is used, the glossy Ag layer 12 having relatively poor corrosion resistance is obtained.
Is protected by the transparent resin 33 and has excellent corrosion resistance.
Since it is exposed as an external connection electrode, the light emitting device has excellent corrosion resistance.

[0023]

As described above, according to the present invention, the glossy metal layer forming the reflective layer is formed in the recess of the three-dimensional molded body, and the metal layer having good bonding property is formed on the upper surface. By satisfying both the reflection property and the bonding property, and by forming a wall portion on the outer peripheral portion of the upper surface to prevent the transparent resin from flowing out, the processing is easy and the luminous efficiency due to leakage light is improved. It has become possible to provide a light emitting device with reduced deterioration.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a light emitting device of the present invention.

FIG. 2 is a cross-sectional view of the light emitting device of FIG.

FIG. 3 is a sectional view of an embodiment of a light emitting device of the present invention.

FIG. 4 is a cross-sectional view of a three-dimensional circuit molded body of the present invention.

FIG. 5 is a cross-sectional view of a three-dimensional circuit molded body of the present invention.

FIG. 6 is a perspective view of a conventional light emitting device.

7 is a cross-sectional view of the light emitting device of FIG.

[Explanation of symbols]

10,18,40 Light emitting device 11 Au layer 12 Glossy Ag layer 15 wall 20 insulating substrate 21 Top surface 22 recess 26 Reflective surface 30 light emitting element 33 transparent resin

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinobu Nakamura             2 6663 Funatsu, Kawaguchiko Town, Minamitsuru District, Yamanashi Prefecture               Kawaguchiko Precision Co., Ltd. (72) Inventor Kazuomi Tsutsui             2 6663 Funatsu, Kawaguchiko Town, Minamitsuru District, Yamanashi Prefecture               Kawaguchiko Precision Co., Ltd. (72) Inventor Joji Sakai             2 6663 Funatsu, Kawaguchiko Town, Minamitsuru District, Yamanashi Prefecture               Kawaguchiko Precision Co., Ltd. (72) Inventor Yu Onoda             2 6663 Funatsu, Kawaguchiko Town, Minamitsuru District, Yamanashi Prefecture               Kawaguchiko Precision Co., Ltd. (72) Inventor Masaaki Watanabe             2 6663 Funatsu, Kawaguchiko Town, Minamitsuru District, Yamanashi Prefecture               Kawaguchiko Precision Co., Ltd. F term (reference) 5F041 AA03 DA07 DA12 DA19 DA36                       DA39 DA43

Claims (5)

[Claims] 1. A three-dimensional circuit molded body is formed by forming a metal layer on the surface of an insulating substrate having a recess and an upper surface around the recess, and a light emitting element is provided in the recess of the three-dimensional circuit molded body. In a light emitting device which is mounted, wire-bonds the light emitting element to a metal layer formed on the upper surface, and seals the upper surface side including the inside of the recess with a transparent resin, in the recess as the metal layer A light-emitting device, wherein a glossy metal layer forming a reflection surface is formed on the upper surface, and a metal layer having good bonding properties is formed on the upper surface portion. 2. The light emitting device according to claim 1, wherein the glossy metal layer is a glossy Ag layer, and the metal layer having good bonding properties is an Au layer. 3. The light emitting device according to claim 1, wherein the metal layer is provided with a slit for dividing the electrode, and the slit is formed in the upper surface portion. 4. The light emitting device according to claim 1, wherein a wall portion for preventing the transparent resin from flowing out is formed on an outer peripheral portion of an upper surface portion of the three-dimensional circuit molded body. 5. The metal layer formed on the surface of the insulating substrate is formed by partially laminating the glossy metal layer and a metal layer having good bonding properties. Item 5. The light emitting device according to any one of items 1 to 4.