LED module having LED chips as light source

• US 8,901,578 B2
• Filed: 05/10/2012
• Issued: 12/02/2014
• Est. Priority Date: 05/10/2011
• Status: Active Grant

• Current Assignee: ROHM Co., Ltd.
• Original Assignee: ROHM Co., Ltd.
• Inventors: Kobayakawa, Masahiko, Isokawa, Shinji, Shimabukuro, Riki
• Primary Examiner(s): NGUYEN, DUY T V
• Application Number:
  US13/468,356
• Publication Number:
  US 20120286301A1
• Time in Patent Office: 936 Days
• Field of Search: 257/80, 257/88, 257/E33.066
• US Class Current: 257/88
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 27/0248 for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection
• CPC Class Codes: H01L 29/866 Zener diodes
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/60 : Reflective elements
• CPC Class Codes: H01L 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01L 33/64 : Heat extraction or cooling elements
• CPC Class Codes: H01L 33/641 : characterized by the materials
• CPC Class Codes: H01L 33/647 : the elements conducting electric current to or from the semiconductor body

Abstract

An LED (Light Emitting Diode) module includes an LED unit having one or more LED chips and a case. The case includes: a body including a base plate made of ceramic, the base plate having a main surface and a bottom surface opposite to the main surface; a through conductor penetrating through the base plate; and one or more pads formed on the main surface and making conductive connection with the through conductor, the pads mounting thereon the LED unit. The through conductor includes a main surface exposed portion exposed to the main surface and overlapping the LED unit when viewed from top, a bottom surface reaching portion connected to the main surface exposed portion and reaching the bottom surface. The pads cover at least a portion of the main surface exposed portion.

Claims

1. An LED (Light Emitting Diode) module comprising:

an LED unit having one or more LED chips; and

a case including;

a body including a base plate made of ceramic, the base plate having a main surface and a bottom surface opposite to the main surface;

a through conductor penetrating through the base plate; and

one or more pads formed on the main surface and making conductive connection with the through conductor, the pads mounting thereon the LED unit,

wherein the through conductor includes;

a main surface exposed portion exposed to the main surface and overlapping the LED unit when viewed from top, at least a part of the main surface exposed portion being buried under the main surface of the base plate, and at least a part of the main surface exposed portion having a caved shape deviated from the LED unit;

a bottom surface exposed portion exposed to the bottom surface; and

a reaching portion connected to the main surface exposed portion and the bottom surface exposed portion,

wherein the pads cover at least a portion of the main surface exposed portion,

wherein the reaching portion is smaller than the main surface exposed portion and the LED unit when viewed from top, and

wherein the main surface exposed portion contains the LED unit when viewed from top.

2. The LED module of claim 1, wherein at least a portion of the reaching portion does not overlap the LED unit.

3. The LED module of claim 1, wherein the pads cover the main surface exposed portion such that the main surface exposed portion is not exposed.

4. The LED module of claim 1, wherein the through conductor is made of Ag.

5. The LED module of claim 1, wherein each of the pads has a surface made of Au.

6. The LED module of claim 1, wherein a mounting electrode making conductive connection with the through conductor is formed on the bottom surface of the base plate.

7. The LED module of claim 1, wherein the body further includes a frame unit made of resin, the frame unit being bonded to the main surface and surrounding the LED unit.

8. The LED module of claim 7, wherein an inner side of the frame unit surrounding the LED unit serves as a reflector.

9. The LED module of claim 8, wherein the reflector has a section perpendicular to a normal line of the main surface, a dimension of the section decreasing as the section becomes more spaced apart from the main surface.

10. The LED module of claim 7, further comprising a transparent resin filling a region surrounded by the frame unit and covering the LED unit, the transparent resin being formed of resin material transmitting light emitted from the LED unit and fluorescent material emitting, when excited by the light emitted from the LED unit, light having a wavelength different from a wavelength of the light emitted from the LED unit.

11. The LED module of claim 1, wherein the reaching portion does not overlap the LED unit when viewed from top.

12. An LED (Light Emitting Diode) module comprising:

an LED unit having one or more LED chips; and

a case including one or more pads mounting thereon the LED unit, a base plate having a main surface on which the pads are formed and a bottom surface opposite to the main surface, and a frame unit bonded to the main surface and surrounding the LED unit,

wherein the base plate is made of ceramic,

wherein the frame unit is made of resin,

wherein the case further includes a through conductor penetrating through the base plate and making conductive connection with the pads,

wherein the through conductor has a main surface exposed portion exposed to the main surface and overlapping the LED unit when viewed from top, a bottom surface exposed portion exposed to the bottom surface, a reaching portion connected to the main surface exposed portion and the bottom surface exposed portion, at least a part of the main surface exposed portion being buried under the main surface of the base plate, and at least a part of the main surface exposed portion having a caved shape deviated from the LED unit,

wherein the pads cover at least a portion of the main surface exposed portion,

wherein the reaching portion is smaller than the main surface exposed portion and the LED unit when viewed from top, and

wherein the main surface exposed portion contains the LED unit when viewed from the top.

13. The LED module of claim 12, wherein an inner side of the frame unit surrounding the LED unit serves as a reflector.

14. The LED module of claim 13, wherein the reflector has a section perpendicular to a normal line of the main surface, a dimension of the section decreasing as the section becomes more spaced apart from the main surface.

15. The LED module of claim 12, further comprising a transparent resin filling a region surrounded by the frame unit and covering the LED unit, the transparent resin being formed of resin material transmitting light emitted from the LED unit and fluorescent material emitting, when excited by the light emitted from the LED unit, light having a wavelength different from a wavelength of the light emitted from the LED unit.

16. The LED module of claim 12, wherein at least a portion of the reaching portion does not overlap the LED unit.

17. The LED module of claim 12, wherein the pads cover the main surface exposed portion such that the main surface exposed portion is not exposed.

18. The LED module of claim 12, wherein the through conductor is made of Ag.

19. The LED module of claim 12, wherein each of the pads has a surface made of Au.

20. The LED module of claim 12, wherein a mounting electrode making conductive connection with the through conductor is formed on the bottom surface of the base plate.

21. The LED module of claim 12, wherein the reaching portion does not overlap the LED unit when viewed from top.