Configurations of a semiconductor light emitting device and planar light source

• US 8,362,493 B2
• Filed: 10/31/2008
• Issued: 01/29/2013
• Est. Priority Date: 11/02/2007
• Status: Active Grant

• Current Assignee: Sanken Electric Company Limited
• Original Assignee: Sanken Electric Company Limited
• Inventors: Sano, Takeshi, Tsukagoshi, Kouji, Hoshino, Masanori
• Primary Examiner(s): Nguyen, Ha Tran T
• Assistant Examiner(s): CHI, SUBERR L
• Application Number:
  US12/262,566
• Publication Number:
  US 20090121248A1
• Time in Patent Office: 1,551 Days
• Field of Search: 257/79, 257/98, 257/99, 257/100, 257/E33.001, 257/81, 257/E33.006, 257/E33.056, 257/E33.066
• US Class Current: 257/79
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/483 Containers
• CPC Class Codes: H01L 33/54 having a particular shape

Abstract

A semiconductor light emitting device includes: a base portion having a concave portion formed in one of major surfaces thereof; and a light emitting element mounted on a bottom surface of the concave portion of the base portion. The base portion comprises a side wall portion that surrounds the light emitting element. The light emitting element is covered with a resin portion filled in the concave portion. At least a part of an upper surface of the resin portion is positioned closer to the bottom surface of the concave portion than an upper surface of the side wall portion.

Claims

1. A semiconductor light emitting device comprising:

a base portion having a concave portion formed in one of major surfaces thereof; and

a light emitting element mounted on a bottom surface of the concave portion of the base portion,

wherein the base portion comprises;

one pair of first side surfaces located opposite to each other; and

one pair of second side surfaces, wherein the second side surfaces are formed between one pair of the first side surfaces, and the lengths of which are shorter than the first side surfaces,

wherein one pair of the first side surfaces and one pair of the second side surfaces define a side wall portion, which extends from the base portion, and which laterally surrounds the light emitting element,

wherein the concave portion reaches the second side surfaces,

wherein the light emitting element is covered with a resin portion filled in the concave portion, and a space defined by the side wall portion,

wherein an upper surface of the resin portion exposed to an outside from the space defined by the side wall portion forms a concave shape such that at least a part of the upper surface of the resin portion is positioned closer to the bottom surface of the concave portion than an upper surface of the side wall portion,

wherein the base portion has a substantially rectangular shape,

wherein the light emitting device comprises a blue light emitting diode, and

wherein the resin portion contains phosphor in order to convert wavelengths of light emitted from the light emitting device so that the light emitted from the light emitting device is mixed with the light whose wavelengths have been converted by the phosphor and the mixed light is emitted through the resin portion.

2. The semiconductor light emitting device according to claim 1, wherein an entire part of the upper surface of the resin portion is not positioned farther away from the bottom surface of the concave portion than the upper surface of the side wall portion.

3. The semiconductor light emitting device according to claim 1, wherein a height defined between the upper surface of the resin portion and a plane containing the bottom surface of the concave portion decreases toward a center of the resin portion in cross-sectional view.

4. The semiconductor light emitting device according to claim 1,

wherein the base portion comprises:

a supporting plate containing metal; and

a surrounding portion that laterally surrounds the supporting plate and includes an extending portion extending upward from an upper surface of the supporting plate, and

wherein the light emitting element is disposed on the supporting plate.

5. The semiconductor light emitting device according to claim 4,

wherein the supporting plate has a groove portion formed thereon, and

wherein the light emitting element is disposed on a bottom surface of the groove portion.

6. The semiconductor light emitting device according to claim 1, wherein the light emitting element is contained within a first portion of the base whose walls are substantially continuous with a second portion of the base.

7. The semiconductor light emitting device according to claim 1, wherein the light emitting element consists of a blue light emitting diode.

9. The semiconductor light emitting device according to claim 1, wherein the resin portion has a liner expansion coefficient not less than 200 ppm/°

C.

8. A planar light source comprising:

a semiconductor light emitting device comprising;

a base portion having a concave portion formed in one of major surfaces thereof; and

a light emitting element mounted on a bottom surface of the concave portion of the base portion,

wherein the base portion comprises;

one pair of first side surfaces located opposite to each other; and

one pair of second side surfaces, wherein the second side surfaces are formed between one pair of the first side surfaces, and the lengths of which are shorter than the first side surfaces,

wherein one pair of the first side surfaces and one pair of the second side surfaces define a side wall portion which extends from the bottom portion, and which laterally surrounds the light emitting element,

wherein the concave portion reaches the second side surfaces,

wherein the light emitting element is covered with a resin portion filled in the concave portion and a space defined by the side wall portion,

wherein an upper surface of the resin portion exposed to an outside from the space defined by the side wall portion forms a concave shape such that at least a part of aft the upper surface of the resin portion is positioned closer to the bottom surface of the concave portion than an upper surface of said side wall portion;

wherein the base portion has a substantially rectangular shape,

wherein the light emitting device comprises a blue light emitting diode, and

wherein the resin portion contains phosphor in order to convert wavelengths of light emitted from the light emitting device so that the light emitted from the light emitting device is mixed with the light whose wavelengths have been converted by the phosphor and the mixed light is emitted through the resin portion; and

a light guide plate into which light emitted from the light emitting element is introduced,

wherein the upper surface of the side wall portion of the base portion is arranged opposite to a side surface of said light guide plate.

10. The planar light source according to claim 8, wherein the resin portion has a linear expansion coefficient not less than 200 ppm/°

C.