LED MODULE AND METHOD OF PREPARING THE LED MODULE, LIGHTING DEVICE

• US 20150137149A1
• Filed: 05/24/2013
• Published: 05/21/2015
• Est. Priority Date: 05/31/2012
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Urano, Yoji, Tanaka, Kenichiro, Nakamura, Akifumi, Hirano, Toru, Hyuga, Hideaki, Suzuki, Masanori, Yokota, Teruhisa
• Granted Patent: US 9,685,594 B2
• Time in Patent Office: Days
• US Class Current: 257/88
• CPC Class Codes: F21K 9/27 Retrofit light sources for lighting devices with two fittings for each light source, e.g. for substitution of fluorescent tubes
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 2924/00014 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 2924/181 Encapsulation
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/504 Elements with two or more 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 33/58 Optical field-shaping elements
• 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 33/642 : characterized by the shape

Abstract

An LED module includes a submount having a face in a thickness direction thereof, an LED chip bonded to the face of the submount with a first bond, and a patterned wiring circuit electrically connected to the LED chip. The first bond transmits light emitted from the LED chip. The submount is a light-transmissive member having light diffusing properties, and a planar size larger than a planar size of the LED chip. The patterned wiring circuit is provided on the face of the submount so as not to overlap the LED chip. The submount is constituted by a plurality of light-transmissive layers which are stacked in the thickness direction and have different optical properties so that a light-transmissive layer of the plurality of light-transmissive layers which is farther from the LED chip is higher in reflectance in a wavelength range of the light emitted from the LED chip.

Claims

1-13. -13. (canceled)

14. An LED module comprising:

a submount having a face in a thickness direction of the submount;

an LED chip bonded to the face with a first bond; and

a patterned wiring circuit electrically connected to the LED chip,

the first bond allowing light emitted from the LED chip to pass therethrough,

the submount being a light-transmissive member having light diffusing properties and having a planar size larger than a planar size of the LED chip,

the patterned wiring circuit being provided on the face of the submount so as not to overlap the LED chip, and

the submount being constituted by a plurality of light-transmissive layers which are stacked in the thickness direction and have different optical properties so that a light-transmissive layer of the plurality of light-transmissive layers which is farther from the LED chip is higher in reflectance in a wavelength range of the light emitted from the LED chip.

15. The LED module according to claim 14, further comprising:

a color conversion portion made of a transparent material containing a first fluorescent material which is excited by the light emitted from the LED chip to emit light having a different color from the light emitted from the LED chip,

the color conversion portion covering sides of the LED chip and an opposite surface of the LED chip from the first bond.

16. The LED module according to claim 15, wherein

the color conversion portion contains a light diffusion material.

17. The LED module according to claim 14, further comprising an opaque substrate,

the submount being bonded to a surface of the opaque substrate with a second bond.

18. The LED module according to claim 17, wherein

at least one of the first bond and the second bond contains a second fluorescent material which is excited by the light emitted from the LED chip to emit light having a different color from the light emitted from the LED chip.

19. The LED module according to claim 14, further comprising a resin portion which is situated over the face of the submount and serves as an outer cover through which light passes last,

the resin portion being made of a transparent resin which contains a light diffusion material.

20. The LED module according to claim 14, further comprising a plurality of the LED chips on the face of the submount,

wherein:

the patterned wiring circuit includes a first conductor and a second conductor that are arranged apart from each other on the face of the submount;

the plurality of the LED chips include a group of LED chips which are connected in series and arranged on a virtual line connecting the first conductor and the second conductor to each other;

an LED chip of the group of LED chips that is closest to the first conductor on the virtual line has an anode electrode which is electrically connected to the first conductor by a first wire;

an LED chip of the group of LED chips that is closest to the second conductor on the virtual line has a cathode electrode which is electrically connected to the second conductor by a second wire; and

adjacent LED chips of the group of LED chips on the virtual line are electrically connected to each other in such a manner that an LED chip of the adjacent LED chips that is closer to the first conductor has a cathode electrode which is electrically connected to an anode electrode of an LED chip of the adjacent LED chips that is closer to the second conductor by a third wire.

21. The LED module according to claim 20, comprising

an encapsulating portion with a band shape which covers the first wire, the second wire, the third wire, and the group of the LED chips arranged on the virtual line,

the encapsulating portion having a recessed portion between the adjacent LED chips on the virtual line for suppressing total reflection of light emitted from the adjacent LED chips.

22. The LED module according to claim 14, further comprising

a reflective layer provided on a further face of the submount in the thickness direction for reflecting the light from the LED chip.

23. The LED module according to claim 22, wherein:

the reflective layer is a metal layer; and

the LED module further comprises a protection layer provided on the further face of the submount for protecting the reflective layer.

24. The LED module according to claim 14, wherein

each of the plurality of light-transmissive layers is a ceramic layer.

25. A method of manufacturing the LED module according to claim 22, comprising:

screen-printing a silver paste on a ceramic green paste, the silver paste being to be formed into the reflection layer, and the ceramic green sheet being to be formed into a light-transmissive layer of the plurality of light-transmissive layer that is farthest from the LED chip; and

sintering the silver paste to form the reflective layer.

26. A lighting device comprising:

a device main body; and

a light source that is the LED module according to claim 14.