JP2000332303A - Semiconductor light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a semiconductor light emitting device which can improve light distribution properties and also can keep a luminous brightness high by increasing a flexibility of shape of a mount part of a lead frame. SOLUTION: A light emitting element 4 is mounted onto a lead frame 1 to be conducted therewith, and sealed with a resin package 7 including the lead frame 1 and element 4 to thereby form a semiconductor light emitting device. In this case, a mount cup 6 of synthetic resin having a light reflecting surface as its inner surface is integrally provided at a location where the lead frame carries the light emitting element 4 so as to surround a lower side of the element 4 and surroundings thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device in which a semiconductor light emitting element is mounted on a mount portion of a lead frame and sealed with a resin. The present invention relates to a semiconductor light emitting device capable of increasing luminance and improving luminance.

[0002]

2. Description of the Related Art A semiconductor light emitting device having a light-emitting diode of each color of red, green, and blue as an element mounted on a mount portion of a lead frame and sealing with resin including bonding wires, for example, to have a shell-shaped outer shape is known. It has been widely known from the past. As the light emitting diode mounted on the lead frame, a light emitting diode in which a substrate is mounted on a mounting portion and a semiconductor lamination surface side is used as a light emitting direction, or a light emitting diode which emits blue light of a GaN-based compound semiconductor using transparent sapphire is used. Is done. The lead frame serves not only as a member for mounting and conducting the light emitting diode, but also serves to reflect light from the light emitting diode toward the light emitting direction to improve luminance.

[0003] In order to function as a lead frame member, the mount portion is formed in a mortar shape so that a light emitting diode can be dropped and mounted, and the bottom surface and the inner peripheral surface are mostly reflective surfaces. It is. It has been conventionally known that the mount portion is plated with high light reflectance in order to enhance its reflection function.

[0004]

However, when a lead frame is manufactured using a metal, a step of, for example, press forming or punching from a material substrate using, for example, a feeding die is included. For this reason, it is necessary to consider the plastic flow of the metal material and the like, and to avoid a partial thickness difference in order to avoid concentration of stress. Therefore, the shape of the mounting part and the thickness relationship between the mounting part and the lead are greatly restricted, and the degree of freedom of design is limited even when trying to optimize for various sizes of light emitting diodes. It tends to be low.

For example, when the bottom surface and the inner peripheral surface of the mount portion are used as a reflection surface, it is possible to optimize the light distribution of high brightness in a narrow range or low brightness in a wide range according to the application. Thus, a high quality light emitting device can be obtained. However, if the degree of freedom of design is restricted, including the mounting portion, light distribution suitable for the application cannot be obtained, and it becomes difficult to control the light emission distribution.

Further, a GaN-based compound semiconductor light emitting device using sapphire as a substrate has p-side and n-side electrodes formed on the surface opposite to the substrate, so that it can be mounted on a lead frame as a flip-chip type. In this case, it is mounted so that the mount part is divided into two and the light emitting element is bridged,
Light is not reflected from the slit portion for splitting into two, which causes a decrease in light emission luminance.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor light emitting device capable of improving the light distribution by increasing the degree of freedom of the shape of a mount portion of a lead frame and maintaining a high light emission luminance.

[0008]

The present invention provides a semiconductor light emitting device in which a semiconductor light emitting element is conductively mounted on a lead frame and sealed with a resin package including the lead frame and the light emitting element. A mounting cup made of a synthetic resin is provided integrally with a portion on which the light emitting element is mounted, surrounding the lower side and the periphery of the light emitting element and having an inner surface as a light reflecting surface.

[0009]

The invention according to claim 1 is a semiconductor light emitting device in which a semiconductor light emitting element is conductively mounted on a lead frame and sealed with a resin package including the lead frame and the light emitting element. A semiconductor light emitting device, wherein a mount cup made of a synthetic resin is provided integrally with a portion where a lead frame mounts the light emitting element and surrounds a lower side and a periphery of the light emitting element and has an inner surface as a light reflecting surface. The degree of freedom in the shape design of the mount cup increases, so that light distribution according to the application can be obtained,
It has the effect of improving light emission luminance by collecting light from the reflecting surface.

According to a second aspect of the present invention, in the semiconductor light emitting device according to the first aspect of the present invention, the mount cup has a light-reflective filler mixed in a synthetic resin of the material. Even if it is a mount cup made of, it has an effect that light reflection by a filler can be used.

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

FIG. 1 is a schematic longitudinal sectional view of a semiconductor light emitting device according to the present invention.

In FIG. 1, a light emitting element 4 is mounted on one lead 2 of a pair of leads 2 and 3 of a metal lead frame 1 whose base end is conductively fixed to a printed wiring board (not shown) or the like. Have been. The light-emitting element 4 is a conventionally known element in which p-side and n-side electrodes are formed on the upper surface and the lower surface, respectively, and is mounted with the substrate facing downward.

A flat portion 2a for conductively mounting the light emitting element 4 is formed at the upper end of the lead 2, and the light emitting element 4 is die-bonded to the upper surface of the flat portion 2a by a conductive adhesive. The printed wiring board and the light emitting element 4 are electrically connected by bonding the wire 5 between the electrode on the upper surface of the light emitting element 4 and the upper end of the lead 3. Further, a mount cup 6 using a synthetic resin is integrally joined to the upper ends of the leads 2 and 3, and the mount cup 6 and the mount cup 6 are sealed by a shell type package 7 made of epoxy resin.

The mount cup 6 is made of, for example, a white liquid crystal polymer (LCP), and is made of a light-reflective compound such as TiO ₂ to reflect light exiting from below and from the light emitting element 4 in the light emitting direction. Is mixed as a filler. The mount cup 6 has a bottom surface slightly lower than the lower end surface of the flat portion 2 a of the lead 2, is formed except for the upper surface of the flat portion 2 a around the light emitting element 4, and surrounds the light emitting element 4. It has a mortar-shaped inner peripheral wall.

In the manufacturing process for integrating the mount cup 6 with the leads 2 and 3, as shown in FIG. 2A, the light emitting element 4 is conductively mounted on the flat portion 2a of the lead 2 and the wire 5 is bonded. After that, mount cup 6
In this case, the upper ends of the leads 2 and 3 are inserted into a molding die for molding. That is, after the mounting of the light emitting element 4 and the bonding of the wire 5 in FIG. 2A, the tips of the leads 2 and 3 are inserted into the mold, and the thermoplastic resin is poured into the mold, and FIG. The mount cup 6 is formed as shown in FIG.

In the above configuration, the light emitting element 4 is disposed so as to be dropped into the bottom of the mortar-shaped mount cup 6, and the mount cup 6 contains TiO ₂ having light reflectivity as a filler. Light emitted from the side surface of the mount cup 4 is reflected from the bottom surface and the inner peripheral surface of the mount cup 6 in the light emitting direction. Since the mount cup 6 is a synthetic resin molded product, a mount cup 6 whose shape and size are freely changed can be used as compared with a conventional mount unit integrated with a metal lead.

For example, if the angle of inclination of the inner surface of the mortar of the mount cup 6 is made small, the reflection surface facing the light emission direction becomes wide, and light emission from the wide light emission surface around the light emitting element 4 can be obtained. Also, as the inner surface inclination angle is increased, the width of the reflecting surface facing the light emission direction is narrowed,
Light emission with higher luminance can be obtained. Therefore, if molds of various shapes are prepared for molding the mount cup 6 and the mount cup 6 is selected so as to have a light emission range and a light emission luminance corresponding to the application, a product excellent in light distribution can be obtained. Can be provided as

Further, even if the mount cup 6 is formed of a resin molded product, since it contains light-reflective TiO ₂ as a filler, the light reflectance can be increased and the light emission luminance can be increased.

FIG. 3 is a schematic longitudinal sectional view of an essential part showing an embodiment having a flip-chip type light emitting element, and FIGS. 4 and 5.
Is a plan view and a bottom view thereof.

In FIG. 3, stays 12a and 13a bent at right angles are respectively provided on the upper ends of a pair of leads 12 and 13 of a lead frame 11 whose base ends are conductively fixed to a printed wiring board (not shown) or the like. Has formed. The electrode patterns 12 are provided on the upper surfaces of the stays 12a and 13a.
b, 13b, and these electrode patterns 12b, 1
The light emitting element 14 is bridged over and electrically connected to 3b. This light-emitting element 14 has Ga on a sapphire substrate 14a.
An n-type layer and a p-type layer of N and a transparent electrode are laminated and provided, and p-side and n-side bump electrodes 14b and 14c are provided;
These bump electrodes 14b and 14c are
b, 12b.

A mount cup 15 made of synthetic resin and surrounding the light emitting element 14 is integrally joined to the upper surfaces of the stays 12a and 13a. As in the previous example, the mount cup 15 is made of a white liquid crystal polymer (LCP) as a material and mixed with a light-reflective compound such as TiO ₂ as a filler. The mount cup 15 is filled in the gap between the electrode patterns 12b and 13b with the lower end placed on the upper surfaces of the stays 12a and 13a, and is surrounded by the inner peripheral surface inclined around the light emitting element 14 in a mortar shape. are doing.

In the embodiment shown in FIGS. 3 to 5, the mounting cup 1 is also connected to the leading end of the lead frame 11.
5 is entirely sealed with an epoxy resin package.

Such a flip-chip type light emitting device 1
Even in the case of 4, the surrounding area is a light-reflective mount cup 1
5, the light emitted from the light emitting element 14 to the side is reflected on the inner peripheral surface of the mount cup 15 in the light emitting direction. Since the metal electrode patterns 12b and 13b and the resin layer of the mount cup 15 filled between the metal electrode patterns 12b and 13b are located below the light emitting element 14, the light emitted downward from the transparent electrode of the light emitting element 14 is The light is reflected in the light emitting direction by the electrode patterns 12 b and 13 b and the resin layer of the mount cup 15. Therefore, the electrode pattern 12
Light can be reflected in the light emission direction and collected, and the light emission luminance can be increased, as compared with the conventional structure in which there is a gap between b and 13b, and light escapes downward.

Also, as in the previous example, the mounting cup 1
Since 5 is a synthetic resin molded product, it can be easily manufactured in a different shape and size, and can be effectively used as a light source having a light distribution suitable for the application as in the previous example.

[0026]

According to the first aspect of the present invention, the degree of freedom in designing the shape of the mount cup is increased, so that the light distribution according to the application can be obtained, and the light emission luminance can be improved by collecting the light from the reflecting surface. be able to.

According to the second aspect of the present invention, the light reflecting function can be provided by mixing the light reflecting filler into the mount cup. Therefore, even if the mount cup is made of a synthetic resin, the light emission luminance is reduced. Nothing.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a semiconductor light emitting device according to an embodiment of the present invention.

2A and 2B are schematic views of a manufacturing process of the semiconductor light emitting device of FIG. 1, wherein FIG. 2A shows a state in which a light emitting element is mounted on a lead frame, and FIG. 2B shows a state in which a mount cup is integrated with the lead frame. Diagram shown

FIG. 3 is a vertical sectional view of a main part of a semiconductor light emitting device in which a flip-chip type light emitting element is incorporated in a lead frame.

FIG. 4 is a plan view of the semiconductor light emitting device of FIG. 3;

FIG. 5 is a bottom view of the semiconductor light emitting device of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lead frame 2 Lead 2a Flat part 3 Lead 4 Light emitting element 5 Wire 6 Mounting cup 7 Package 11 Lead frame 12, 13 Lead 12a, 13a Stay 12b, 13b Electrode pattern 14 Light emitting element 14a Substrate 14b, 14c Electrode 15 Mounting cup

Claims (2)

[Claims] 1. A semiconductor light-emitting device in which a semiconductor light-emitting element is conductively mounted on a lead frame and sealed with a resin package including the lead frame and the light-emitting element. A semiconductor light-emitting device, wherein a mount cup made of a synthetic resin is provided integrally surrounding a lower side and a periphery of the light-emitting element and having an inner surface as a light reflecting surface. 2. The semiconductor light emitting device according to claim 1, wherein the mount cup has a light-reflective filler mixed in a synthetic resin of the material.