Light source and vehicle lamp

• US 8,142,060 B2
• Filed: 02/18/2009
• Issued: 03/27/2012
• Est. Priority Date: 02/20/2008
• Status: Active Grant

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: Saida, Takahiro, Ueno, Kazuhiko
• Primary Examiner(s): PAYNE, SHARON E
• Application Number:
  US12/372,831
• Publication Number:
  US 20090244921A1
• Time in Patent Office: 1,133 Days
• Field of Search: 362/539, 362/545, 257/91, 257/89, 257/81, 257/79, 257/88, 257/98, 257/99, 257/E33.066, 257/E33.068, 313/114, 313/499
• US Class Current: 362/539
• CPC Class Codes: F21S 41/143 the main emission direction of the LED being parallel to the optical axis of the illuminating device
• CPC Class Codes: F21S 41/151 arranged in one or more lines
• CPC Class Codes: F21S 41/43 characterised by the shape thereof
• CPC Class Codes: F21W 2102/00 Exterior vehicle lighting devices for illuminating purposes
• CPC Class Codes: F21W 2102/135 the light having cut-off lines, i.e. clear borderlines between emitted regions and dark regions
• CPC Class Codes: F21W 2102/30 Fog lights
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• 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 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• 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 2224/8592 Applying permanent coating, e.g. protective coating
• 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 2924/19107 off-chip wires
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

The disclosed subject matter includes light sources that have high use efficiency and a favorable bright distribution, and includes vehicle lamps that have both a favorable light distribution pattern and a capability of being simply composed by using the LED light sources. The light source can include a base board, at least one die bonding pad and wire bonding pad on the base board, at least one LED chip mounted on the die bonding pad and connected to respective bonding pads, and an encapsulating resin over the LED chip. The at least one LED chip can emit a uniform light with a distribution electrode on a top surface thereof and can form a favorable light distribution using a shield electrode on the top surface. The vehicle lamp can include the light source and an optical lens selected according to a kind and/or design of a vehicle lamp.

Claims

1. A light source device, comprising:

a base board;

a first electrode and a second electrode;

at least one die bonding pad located adjacent the base board and electrically connected to the first electrode;

at least one wire bonding pad located adjacent the base board and the at least one die bonding pad and electrically connected to the second electrode;

at least one LED chip having a top surface including adjacent corner regions, a bottom surface located adjacent the at least one die bonding pad, a first chip electrode electrically connected to the at least one die bonding pad, and a second chip electrode forming an edge portion at the top surface of the at least one LED chip and located adjacent the at least one wire bonding pad, wherein the edge portion of the second chip electrode includes at least one of the adjacent corner regions of the top surface located toward the at least one wire bonding pad;

a bonding wire electrically connecting the second chip electrode and the wire bonding pad; and

an encapsulating resin disposed adjacent the base board and encapsulating each of the at least one LED chip and the bonding wire.

2. The light source device according to claim 1, further comprising:

a distribution electrode including a plurality of strips adjacent the top surface of the at least one LED chip and connected to the second chip electrode at the top surface of the at least one LED chip.

3. The light source device according to claim 1, wherein the top surface of the at least one LED chip includes an exposed surface located beyond the second chip electrode;

and

the light source device further includes a wavelength-conversion material covering at least the exposed surface.

4. The light source device according to claim 2, wherein the top surface of the at least one LED chip includes an exposed surface located beyond the second chip electrode;

and

the light source device further includes a wavelength-conversion material covering at least the exposed surface.

5. The light source device according to claim 2, wherein the at least one LED chip includes at least one of a blue LED chip, an ultraviolet LED chip, a red LED chip, a yellow LED chip, and a mixture chip, where the mixture chip includes a red LED chip, a green LED chip and a blue LED chip.

6. A light source device, comprising:

a base board;

a first electrode and a second electrode;

at least one die bonding pad located adjacent the base board and electrically connected to the first electrode;

at least one wire bonding pad located adjacent the base board and the at least one die bonding pad and electrically connected to the second electrode;

at least one LED chip having,

a top surface having an edge line and adjacent corner regions located adjacent the at least one wire bonding pad and an exposed surface,

a bottom surface connected to the at least one die bonding pad,

a first chip electrode electrically connected to the at least one die bonding pad, and

a shield electrode formed at the top surface of the at least one LED chip, covering the adjacent corner regions of the top surface, and including a first edge line substantially aligned with the edge line of the top surface of the at least one LED chip and located adjacent the at least one wire bonding pad, and a second edge line opposite the first edge line formed in a straight line at the top surface of the at least one LED chip;

a bonding wire electrically connecting the shield electrode and the at least one wire bonding pad;

a wavelength-conversion material covering at least the exposed surface of the top surface of the LED chip; and

an encapsulating resin disposed adjacent the base board and encapsulating each of the at least one LED chip and the bonding wire.

7. The light source device according to claim 6, wherein the light source is configured for use as a vehicle lamp.

8. The light source device according to claim 6, further comprising:

a distribution electrode including a plurality of strips at the top surface of the LED chip and connected to the shield electrode at the top surface of the at least one LED chip.

9. The light source device according to claim 8, wherein the bonding wire electrically connects the shield electrode to the at least one wire bonding pad at a position closer to the second edge line than the first edge line.

10. The light source device according to claim 9, further comprising:

a reflecting layer located between the top surface of the at least one LED chip and the shield electrode, wherein a portion of the shield electrode directly contacts the top surface of the at least one LED chip adjacent to the second edge line of the shield electrode.

11. The light source device according to claim 10, wherein the reflecting layer includes an insulating material and the shield electrode includes a slit that exposes a part of the reflecting layer that lies below the slit.

16. The light source device according to claim 9, wherein the at least one LED chip includes a plurality of LED chips adjacent with respect to each other, and the second edge line of the shield electrode of at least one of the plurality of LED chips slants toward the second edge line of the shield electrode of another one of the plurality of LED chips.

18. The light source device according to claim 10, wherein the at least one LED chip includes a plurality of LED chips adjacent with respect to each other, and the second edge line of the shield electrode of at least one of the plurality of LED chips slants toward the second edge line of the shield electrode of another one of the plurality of LED chips.

19. A vehicle lamp including the light source device according to claim 16, comprising:

a projection lens located adjacent the light source device.

12. A light source device, comprising:

a base board;

a first electrode and a second electrode;

at least one die bonding pad located adjacent the base board and electrically connected to the first electrode;

at least one wire bonding pad located adjacent the base board and the at least one die bonding pad and electrically connected to the second electrode;

at least one LED chip having,

a top surface having an edge line and an exposed surface,

a bottom surface connected to the at least one die bonding pad,

a first chip electrode electrically connected to the at least one die bonding pad, and

a shield electrode formed at the top surface of the at least one LED chip, and including a first edge line substantially aligned with the edge line of the top surface of the at least one LED chip and located adjacent the at least one wire bonding pad, and a second edge line opposite the first edge line formed in a straight line at the top surface of the at least one LED chip;

a bonding wire electrically connecting the shield electrode and the at least one wire bonding pad;

a wavelength-conversion material covering at least the exposed surface of the top surface of the LED chip; and

an encapsulating resin disposed adjacent the base board and encapsulating each of the at least one LED chip and the bonding wire,

wherein the bonding wire electrically connects the shield electrode to the at least one wire bonding pad at a position closer to the second edge line than the first edge line.

13. The light source device according to claim 12, further comprising:

a reflecting layer located between the top surface of the at least one LED chip and the shield electrode, wherein a portion of the shield electrode directly contacts the top surface of the at least one LED chip adjacent to the second edge line of the shield electrode.

14. The light source device according to claim 13, wherein the reflecting layer includes an insulating material and the shield electrode includes a slit that exposes a portion of the reflecting layer that lies below the slit.

15. The light source device according to claim 12, wherein the at least one LED chip includes a plurality of LED chips adjacent with respect to each other, and the second edge line of the shield electrode of at least one of the plurality of LED chips slants toward the second edge line of the shield electrode of another one of the plurality of LED chips.

17. The light source device according to claim 13, wherein the at least one LED chip includes a plurality of LED chips adjacent with respect to each other, and the second edge line of the shield electrode of at least one of the plurality of LED chips slants toward the second edge line of the shield electrode of another one of the plurality of LED chips.

20. A vehicle lamp including the light source device according to claim 17, comprising:

a projection lens located adjacent the light source device.

21. A light source device, comprising:

a base board;

a first electrode and a second electrode;

an LED chip located adjacent the base board and electrically connected to the first electrode and second electrode, and the LED chip including a top light emitting surface having adjacent corner regions; and

at least one of,

a shielding electrode connected to the adjacent corner regions of the top light emitting surface of the LED chip and configured to block light emitted from the LED chip to form a light distribution pattern, the shielding electrode electrically connected with at least one of the first electrode and second electrode, and electrically connected to the LED chip, such that when a pre-set electric current passes through the shielding electrode the LED chip emits light, and

a distribution electrode connected to the adjacent corner regions of the top light emitting surface of the LED chip and including a plurality of elongate strips locate adjacent each other and covering a majority of the top light emitting surface of the LED chip, the distribution electrode electrically connected with at least one of the first electrode and second electrode, and electrically connected to the LED chip, such that when a pre-set electric current passes through the distribution electrode the LED chip emits light.

22. The light source device according to claim 21, further comprising:

a bonding wire electrically connecting the shielding electrode and the first electrode.

23. The light source device according to claim 22, further comprising:

an encapsulating resin disposed adjacent the base board and encapsulating each of the at least one LED chip, the bonding wire, and the shielding electrode.

24. The light source device according to claim 21, further comprising:

a reflecting layer located between the top surface of the LED chip and the shield electrode, wherein a portion of the shield electrode directly contacts the top surface of the LED chip adjacent to a second edge line of the shield electrode that forms a light distribution cutoff.

25. The light source device according to claim 21, wherein the shielding electrode includes an outermost peripheral first edge on a first side of the shielding electrode and a second outermost peripheral edge located on a second side of the shielding electrode, the first side of the shielding electrode being directly opposed to the second side of the shielding electrode, the shielding electrode includes a slit opening spaced from the second outermost peripheral edge.