Light-emitting diode with a base

• US 7,642,704 B2
• Filed: 06/21/2005
• Issued: 01/05/2010
• Est. Priority Date: 06/21/2004
• Status: Active Grant

• Current Assignee: Citizen Electronics Company Limited
• Original Assignee: Citizen Electronics Company Limited
• Inventors: Kikuchi, Satoru, Imai, Sadato
• Primary Examiner(s): Patel; Nimeshkumar D.
• Assistant Examiner(s): Walford; Natalie K
• Application Number:
  US11/157,171
• Publication Number:
  US 20060001361A1
• Time in Patent Office: 1,659 Days
• Field of Search: None
• US Class Current: 313/483
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/10253 Silicon [Si]
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/64 Heat extraction or cooling elements
• CPC Class Codes: H05K 1/0204 using means for thermal conduction connection in the thickness direction of the substrate H05K1/0207 takes precedence
• CPC Class Codes: H05K 1/021 Components thermally connected to metal substrates or heat-sinks by insert mounting
• CPC Class Codes: H05K 1/182 associated with components mounted in the printed circuit board, e.g. insert mounted components [IMC]
• CPC Class Codes: H05K 2201/09181 Notches in edge pads
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: H05K 3/0061 onto a metallic substrate, e.g. a heat sink heat sinks for electric apparatus H05K7/20
• CPC Class Codes: H05K 3/3442 having edge contacts, e.g. leadless chip capacitors, chip carriers

Abstract

The LED comprises: a base having high thermal conductivity and having a mounting surface for die bonding; a printed circuit board mounted on the base and having a hole to expose a part of the mounting surface of the base and having a protruding portion projecting horizontally outward on the outer periphery of the base; an LED element mounted on the mounting surface of the base exposed in the hole of the printed circuit board; and a resin material sealing the LED element from above; wherein through-holes electrically connected to the LED element are formed at the outer periphery of the protruding portion and an external connection electrode is provided to the upper and lower surfaces of the through-holes.

This LED enhances the heat dissipating effect to enable generation of high-luminance light and can also be mounted on either the upper or lower surface of a motherboard.

Claims

1. A light-emitting diode with a base comprising:

a base made of a material having a high thermal conductivity,

the base having an upper surface, a lower surface and a periphery that extends between the upper and lower surfaces;

a printed circuit board mounted on the upper surface of the base, the printed circuit board having an upper surface, a lower surface, a hole passing through the upper and lower surfaces of the printed circuit board, an electrode pattern provided at least on the upper surface of the printed circuit board, a protruding portion horizontally extending from an outer edge of the base, and at least a pair of external connection electrodes provided on at least a part of the protruding portion and electrically connected to the electrode pattern;

at least one light-emitting diode element mounted on the upper surface of the base in the hole of the printed circuit board and electrically connected to the electrode pattern of the printed circuit board; and

a resin material sealing the at least one light-emitting diode element.

2. The light-emitting diode with a base according to claim 1, wherein the base is made of one among metal, metal alloy and ceramics.

3. The light-emitting diode with a base according to claim 1, wherein the base is made of one among copper, copper alloy, aluminum, aluminum alloy and aluminum-based ceramics.

4. The light-emitting diode with a base according to claim 1, further comprising a sub-mount substrate provided on the upper surface of the base, wherein the light-emitting diode element is mounted on the sub-mount substrate.

5. The light-emitting diode with a base according to claim 4, wherein the sub-mount substrate is made of one among an aluminum-based ceramics and silicone.

6. The light-emitting diode with a base according to claim 1 further comprising a frame having a light reflecting member on its inner circumferential surface, wherein the frame is arranged around the resin material to surround the light-emitting diode element and the base is larger in size than the frame in top plan view.

7. The light-emitting diode with a base according to claim 1, wherein a plurality of light-emitting diode elements are mounted on the upper surface of the base.

8. The light-emitting diode with a base according to claim 1, wherein:

the protruding portion has through-holes at a side surface of the protruding portion; and

each of the external connection electrodes includes electrodes disposed on the upper and lower surfaces of the printed circuit board, and the electrodes are disposed adjacent to and electrically connected to the corresponding through-hole.

9. The light-emitting diode with a base according to claim 1,

wherein the resin material extends into the hole provided in the printed circuit board and contacts a portion of the printed circuit board around the hole.

10. An electronic instrument comprising;

a mother board provided with an opening that has a peripheral edge; and

the light-emitting diode with a base according to claim 1, mounted on the mother board; and

wherein;

the base of said light-emitting diode is inserted in the opening in the mother board; and

the external connection electrodes provided in the protruding portion of the printed circuit board are fixed to the peripheral edge of the opening in the mother board by soldering.