Light emitting apparatus and method for producing the same

Abstract

A light emitting apparatus including a base (2) having electrodes (6a, 6b), an LED (4) mounted on the base and electrically connected through electrical connecting members to the electrodes, a translucent sealing resin (8) to seal the light emitting element, a wavelength conversion material (9) to convert at least one portion of light emitted from the light emitting element to a different wavelength and a precipitation-prevention agent (10) to reduce precipitation of the wavelength conversion material being contained in the sealing resin, the precipitation-prevention agent being capable of controlling an amount of the wavelength conversion material precipitated.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a first embodiment of a light emitting apparatus according to the present invention.

FIG. 2 is an enlarged sectional view for explaining how emission takes place in the light emitting apparatus according to the present invention.

FIG. 3A is a sectional view showing a mounting process to fix an LED of the light emitting apparatus to a base.

FIG. 3B is a sectional view showing a mounting process to perform a wire-bonding of the LED.

FIG. 4A is an explanatory view showing a mixing process in which a wavelength conversion material and a precipitation-prevention material are mixed in a resin which is used to seal the LED according to the present invention.

FIG. 4B is an explanatory view showing a process to agitate the resin after mixing the wavelength conversion material and the precipitation-prevention material in the resin applied to the light emitting apparatus according to the present invention.

FIG. 5A is a sectional view showing a process in which the resin is applied to the light emitting apparatus according to the present invention.

FIG. 5B is a sectional view showing a heating process in which the light emitting apparatus according to the present invention is heated and the resin hardened.

FIG. 6A is a graph showing a relationship between a heating temperature for heating the light emitting apparatus according to the present invention and a change in viscosity of the resin.

FIG. 6B is a graph showing a relationship between a heating time for heating the light emitting apparatus according to the present invention and a change in viscosity of the resin.

FIG. 7A is a schematically sectional view showing a state in which a small amount of precipitation of the wavelength conversion material has occurred inside the resin in the light emitting apparatus according to the present invention.

FIG. 7B is a schematically sectional view showing a state in which an appropriate amount of precipitation of the wavelength conversion material has occurred inside the resin in the light emitting apparatus according to the present invention.

FIG. 7C is a schematically sectional view showing a state in which a large amount of precipitation of the wavelength conversion material has occurred inside the resin in the light emitting apparatus according to the present invention.

FIG. 8 is a perspective view showing a second embodiment of the light emitting apparatus according to the present invention.

FIG. 9A is a schematically sectional view showing a conventional light emitting apparatus.

FIG. 9B is an enlarged sectional view to explain operation of the conventional light emitting apparatus.

Claims

1. A light emitting apparatus, comprising: a light emitting element; anda resin sealing the light emitting element,a wavelength conversion material to convert at least one portion of light emitted from the light emitting element to a different wavelength and a precipitation-prevention agent being contained in the resin,the precipitation prevention agent being in the resin for controlling precipitation of the wavelength conversion material by use of difference between a cure temperature of resin and an effect-starting-to-decrease temperature of the precipitation prevention agent.

2. The light emitting apparatus according to claim 1, wherein the resin hardens at the cure temperature higher than or equal to the effect-starting-to-decrease temperature of the precipitation-prevention agent.

3. The light emitting apparatus according to claim 1, wherein precipitation of the wavelength conversion material is promoted by decreasing the precipitation-prevention effect.

4. The light emitting apparatus according to claim 2, wherein the precipitation-prevention agent is made of a fatty acid amide and decreases precipitation-prevention effect at a temperature lower than or equal to the cure temperature of the resin.

5. A method for producing a light emitting apparatus, comprising: a process for mounting a light emitting element on a base and electrically connecting the light emitting element and the base;a process for including a wavelength conversion material to convert at least one portion of light emitted from the light emitting element to a different wavelength and a precipitation-prevention agent having an effect-starting-to-decrease temperature lower than a cure temperature of a resin;a process for agitating the wavelength conversion material and the precipitation-prevention agent which are contained in the resin;a process for applying the resin so as to seal the light emitting element; anda process for heating the sealing resin at a temperature greater than the effect-starting-to-decrease temperature of the precipitation-prevention agent for a predetermined time to seal the light emitting element and control an amount of the wavelength conversion material precipitated.

6. The method for producing a light emitting apparatus according to claim 5, wherein the amount of the wavelength conversion material precipitated is controlled by adjusting a heating temperature and a heating time in the heating process.