WHITE LED LAMP, BACKLIGHT, LIGHT EMITTING DEVICE, DISPLAY DEVICE AND ILLUMINATION DEVICE

• US 20110006334A1
• Filed: 02/19/2009
• Published: 01/13/2011
• Est. Priority Date: 02/25/2008
• Status: Active Grant

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Materials Company Limited (Toshiba Corporation)
• Inventors: Toyoshima, Masaki, Ishii, Tsutomu, Ito, Yumi, Sakai, Ryo, Nakagawa, Katsutoshi, Takeuchi, Hajime, Shirakawa, Yasuhiro, Ooya, Yasumasa
• Granted Patent: US 8,471,283 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: C09K 11/584 with zinc or cadmium
• CPC Class Codes: C09K 11/642 with zinc or cadmium
• CPC Class Codes: C09K 11/7734 Aluminates
• CPC Class Codes: C09K 11/77342 Silicates
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: C09K 11/7739 with halogens
• CPC Class Codes: C09K 11/7741 Sulfates
• CPC Class Codes: C09K 11/7789 Oxysulfides
• CPC Class Codes: H01L 2224/48091 Arched
• 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 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 33/32 containing nitrogen
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• 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 33/60 Reflective elements
• CPC Class Codes: H01L 33/642 : characterized by the shape
• CPC Class Codes: H05B 33/14 : characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: H05B 33/20 : characterised by the chemical or physical composition or the arrangement of the material in which the electroluminescent material is embedded
• CPC Class Codes: Y02B 20/00 : Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A white LED lamp including: a conductive portion; a light emitting diode chip mounted on the conductive portion, for emitting a primary light having a peak wavelength of 360 nm to 420 nm; a transparent resin layer including a first hardened transparent resin, for sealing the light emitting diode chip; and a phosphor layer covering the transparent resin layer, the phosphor layer being formed by dispersing a phosphor powder into a second hardened transparent resin, and the phosphor powder receiving the primary light and radiating a secondary light having a wavelength longer than that of the primary light. An energy of the primary light contained in the radiated secondary light is 0.4 mW/lm or less. In the white LED lamp, a backlight, and an illumination device using the white LED lamp an amount of UV light to be contained in the released light and an amount of heat to be generated from the lamp are decreased to be small.

Claims

1. A white LED lamp comprising:

a conductive portion;

a light emitting diode chip, which is mounted on the conductive portion, for emitting a primary light having a peak wavelength of 360 nm to 420 nm;

a transparent resin layer, which is composed of a first hardened transparent resin, for sealing the light emitting diode chip; and

a phosphor layer for covering the transparent resin layer, the phosphor layer being formed by dispersing a phosphor powder into a second hardened transparent resin, and the phosphor powder receiving the primary light and radiating a secondary light having a wavelength longer than that of the primary light,

wherein an energy of the primary light contained in the radiated secondary light is 0.4 mW/lm or less.

2. The white LED lamp according to claim 1, wherein said phosphor powder contains a blue phosphor powder for emitting a blue light having a peak wavelength of 430 nm to 460 nm, and a ratio of a peak strength of the primary light with respect to that of the blue light in an emission spectrum of the radiated secondary light is 0.5 or less.

3. The white LED lamp according to claim 1, wherein said phosphor powder has an average grain size of 10 μ

m or more.

4. The white LED lamp according to claim 1, wherein said phosphor layer has a thickness of 0.1 mm or more.

5. The white LED lamp according to claim 1, wherein said white LED lamp has a luminous efficiency of 20 lm/W or more.

6. The white LED lamp according to claim 1, wherein said phosphor powder contains:

a blue phosphor powder for emitting blue light;

a green phosphor powder for emitting green light; and

a red phosphor powder for emitting red light.

7. The white LED lamp according to claim 1, wherein said phosphor powder contains:

a blue phosphor powder for emitting blue light;

a yellow phosphor powder for emitting yellow light; and

a red phosphor powder for emitting red light.

8. The white LED lamp according to claim 1, wherein said phosphor powder contains:

a blue phosphor powder for emitting blue light;

a green phosphor powder for emitting green light;

a yellow phosphor powder for emitting yellow light and a red phosphor powder for emitting red light.

9. The white LED lamp according to claim 6, wherein said blue phosphor powder contains a blue phosphor powder having a composition expressed by an equation (1):

(Sr_1-x-y-zBa_xCa_yEu_z)₅(PO₄)₃Cl  

 

(1)

wherein x, y and z respectively satisfy the relations 0≦

x<

0.5, 023 y<

0.1, 0.005<

z<

0.1.

10. The white LED lamp according to claim 6, wherein said green phosphor powder is composed of europium- manganese activated aluminate having a composition expressed by an equation (2):

(Br_1-x-y-zSr_xCa_yEu_z) (Mg_1-uMn_u) Al₁₀O₁₇  

 

(2)

wherein x, y, z and u respectively satisfy the relations 0≦

x<

0.2, 0≦

y<

0.1, 0.005<

z<

0.5, 0.1<

u<

0.5.

11. The white LED lamp according to claim 7, wherein said yellow phosphor powder contains a yellow phosphor powder having a composition expressed by an equation (3):

ZnS;

Au_cAl_d  

 

(3)

wherein c and d respectively satisfy the relations 0.0001<

c, d<

0.002.

12. The white LED lamp according to claim 7, wherein said yellow phosphor powder contains a yellow phosphor powder having a composition expressed by an equation (4):

(Sr_2-x-y-z-uBa_xMg_yEu Mn_u) SiO₄  

 

(4)

wherein x, y, z and u respectively satisfy the relations 0.1<

x<

0.4, 0.005<

y<

0.21, 0.05<

z<

0.3, 0.001<

u<

0.04.

13. The white LED lamp according to claim 6, wherein said red phosphor powder is composed of europium activated lanthanum oxysulfide having a composition expressed by an equation (5):

(La_1-x-yEu_xM_y)₂O₂S  

 

(5)

wherein M is at least one element selected from a group consisting of Sb, Sm, Ga and Sn, while x and y respectively satisfy the relations 0.01<

x<

0.15, 0≦

y<

0.03.

14. The white LED lamp according to claim 6, wherein said red phosphor powder contains a red phosphor powder having a composition expressed by an equation (6):

(Sr_xCa_1-x)SiAlN₃;

Eu  

 

(6)

wherein x satisfies a relation 0≦

x<

0.4.

15. The white LED lamp according to claim 6, wherein said phosphor powder contains:

the blue phosphor powder composed of an europium activated halo phosphate having the composition expressed by the equation (1);

the green phosphor powder composed of an europium/manganese activated aluminate having the composition expressed by the equation (2); and

the red phosphor powder composed of an europium activated lanthanum oxysulfide having the composition expressed by the equation (5).

16. The white LED lamp according to claim 7, wherein said blue phosphor powder contains the blue phosphor powder having the composition expressed by the equation (1);

said yellow phosphor powder contains at lest one of the yellow phosphor powder having the composition expressed by the equation (3) and the yellow phosphor powder having the composition expressed by the equation (4); and

said red phosphor powder contains at lest one of the red phosphor powder having the composition expressed by the equation (5) and the red phosphor powder having the composition expressed by the equation (6).

17. The white LED lamp according to claim 1, wherein said conductive portion is provided on an insulating portion thereby to constitute a substrate, and the insulating portion is either one of an alumina plate, an aluminum nitride plate and a glass epoxy plate provided with a heat radiation via.

18. The white LED lamp according to claim 17, wherein a thermal resistance Rth per one light emitting diode chip between a junction portion of the light emitting diode chip and a rear surface of the substrate is 40°

C./W or less.

19. The white LED lamp according to claim 1, wherein said conductive portion is a light reflecting electrode.

20. The white LED lamp according to claim 19, wherein said light reflecting electrode is an electrode composed of at least one metal selected from a group consisting of Ag, Pt, Ru, Pd and Al.

21. The white LED lamp according to claim 1, wherein at a surface of said conductive portion is provided with a light reflecting layer.

22. The white LED lamp according to claim 21, wherein said light reflecting layer is a cover layer containing fine powder composed of inorganic substance selected from a group consisting of titanium oxide, barium sulphide, alumina and silica.

23. The white LED lamp according to claim 21, wherein said light reflecting layer is a cover layer composed of at least one metal selected from a group consisting of Al, Ag, Pt, Ru and Pd.

24. The white LED lamp according to claim 1, wherein at surface of said phosphor layer is further formed with a UV light absorbing layer which is formed by dispersing UV light absorbing powder into a third hardened transparent resin.

25. The white LED lamp according to claim 24, wherein said UV light absorbing powder is fine powder composed of inorganic substance selected from a group consisting of titanium oxide, zinc oxide and cerium oxide.

26. The white LED lamp according to claim 1, wherein said light emitting diode chip is InGaN type, GaN type or A1GaN type light emitting diode chip.

27. A backlight comprising the white LED lamp according to claim 1.

28. A lighting device comprising the white LED lamp according to claim 1.

29. A light emitting device comprising:

a laser diode for emitting a laser light having a peak wave length of 360 nm to 420 nm; and

a phosphor layer for being excited by the laser light and emitting blue, green and red lights.

32. The light emitting device according to claim 29, wherein said phosphor constituting the phosphor layer for emitting the blue light has at least one composition expressed by general formulas:

(Sr_1-x-y-zBa_xCa_yEu_z)₅(PO₄)₃Cl

wherein x, y and z respectively satisfy the relations x, y<

0.3 and 0.001<

z<

0.2;

(Ba_1-x, Eu_x)MgAl₁₀O₁₇

wherein x satisfies the relation 0.01<

x<

0.3; and

(Ba_3-x-y, Sr_x, Eu_y)Mg_zSi₂O₈

wherein x, y and z respectively satisfy the relations 0≦

x<

2.9, 0.02<

y<

0.4, 0.95<

z<

1.4.

33. The light emitting device according to claim 29, wherein said phosphor constituting the phosphor layer for emitting the green light has at least one composition expressed by general formulas:

(Ba_1-x, Eu_x) (Mg_1-y, Mn_y)Al₁₀O₁₇

wherein x and y respectively satisfy the relations 0.05<

x<

0.5; and

0.1<

y<

0.6;

(Sr_2-y-z-ω

, Ba_xMg_yMn_z, Eu_ω

)SiO₄

wherein x, y, z and w respectively satisfy the relations 0.05<

x<

1, 0.05<

y<

0.2, 0.002<

z<

0.009, 0.03<

ω

<

0.3;

ZnS;

Au_x, Al_y

wherein x and y respectively satisfy the relations 0.0002≦

x≦

0.015, 0.0001≦

y≦

0.0012;

(Sr_1-x-y, Ca_x, Eu_y)Ga₂S₄

wherein x and y respectively satisfy the relations x<

0.2, 0.05<

y<

0.3; and

(Sr_3-x, Eu_x)Si_yAl_zO_vN_ω

wherein x, y, z, v andw respectively satisfy the relations x<

0.2, 12 <

y<

14, 2 <

z<

4, 1<

v<

3, 20<

ω

<

22.

34. The light emitting device according to claim 29, wherein said phosphor constituting the phosphor layer for emitting the red light has at least one composition expressed by general formulas:

(La_1-x, Eu_xSm_y)₂O₂S

wherein x and y respectively satisfy the relations 0.01<

x<

0.2 and 0.00005<

y<

0.05;

(Ca_1-x, Eu_x)AlSiN₃

wherein x satisfies the relation 0.005<

x<

0.03;

(Sr_2-x-y-z-u, Ca_xMg_yEu_z, Mn_u)SiO₄

wherein x, y, z and u respectively satisfy the relations 0.05<

x<

0.4, 0.005 <

y<

0.21, 0.05<

z<

0.3, 0.001<

u<

0.04; and

(Ba_3-x-y-z, Sr_xEu_yMn_z)Mg_ω

Si₂O₈

wherein x, y, z andw respectively satisfy the relations 0≦

x<

0.2, 0.02 <

y <

0.6, 0.05<

z<

1.5, 0.95<

ω

<

1.4.

30. A display device comprising:

a laser diode for emitting a laser light having a peak wave length of 360 nm to 420 nm; and

a phosphor screen having a predetermined pattern which is formed by arranging phosphor layers in two dimensional directions, the phosphor layers emitting red, green or blue lights when excited by the laser light,

wherein the laser light scans on the phosphor screen and an image is displayed by a light excited by the laser light.

35. The display device according to claim 30, wherein said phosphor constituting the phosphor layer for emitting the blue light has at least one composition expressed by general formulas:

(Sr_1-x-y-zBa_xCa_yEu_z)₅(PO₄)₃Cl

wherein x, y and z respectively satisfy the relations x, y <

0.3 and 0.001<

z<

0.2;

(Ba_1-x, Eu_x)MgAl₁₀O₁₇

wherein x satisfies the relation 0.01<

x<

0.3; and

(Ba_3-x-y, Sr_x, Eu_y)Mg_zSi₂O₈

wherein x, y and z respectively satisfy the relations 0≦

x<

2.9, 0.02<

y<

0.4, 0.95<

z<

1.4.

36. The display device according to claim 30, wherein said phosphor constituting the phosphor layer for emitting the green light has at least one composition expressed by general formulas:

(Ba_1-xEu_x) (Mg_1-y, Mn_y)Al₁₀O₁₇

wherein x and y respectively satisfy the relations 0.05<

x<

0.5, and 0.1<

y<

0.6;

(Sr_2-x-y-z-ω

Ba_xMg_y, Mn_z, Eu_ω

)SiO₄

wherein x, y, z andco respectively satisfy the relations 0.05<

x<

1, 0.05 <

y<

0.2, 0.002<

z<

0.009, 0.03<

ω

<

0.3;

ZnS;

Au_xAl_y

wherein x and y respectively satisfy the relations 0.0002≦

x≦

0.015, 0.0001≦

y≦

0.0012;

(Sr_1-x-y, Ca_x, Eu_y)Ga₂S₄

wherein x and y respectively satisfy the relations x<

0.2, 0.05 <

y<

0.3; and

(Sr_3-xEu_x)Si_yAl_zO_vN_ω

wherein x, y, z, v and 107 respectively satisfy the relations x<

0.2, 12 <

y<

14, 2 <

z<

4, 1<

v<

3, 20<

ω

22.

37. The display device according to claim 30, wherein said phosphor constituting the phosphor layer for emitting the red light has at least one composition expressed by general formulas:

(La_1-xEu_xSm_y)₂O₂S

wherein x and y respectively satisfy the relations 0.01<

x<

0.2 and 0≦

y≦

0.2;

(Ca_1-x, Eu_x)AlSiN₃

wherein x satisfies the relation 0.005<

x<

0.03;

(Sr_2-x-y-z-u, Ca_xMg_y, Eu_z, Mn_u)SiO₄

wherein x, y, z and u respectively satisfy the relations 0.05<

x<

0.4, 0.005 <

y <

0.21, 0.05<

z<

0.3, 0.001<

u<

0.04; and

(Ba_3-x-y-z, Sr_xEu_y, Mn_z)Mg_ω

Si₂O₈

wherein x, y, z andw respectively satisfy the relations 0≦

x<

0.2, 0.02 <

y <

0.6, 0.05<

z<

1.5, 0.95<

ω

<

1.4.

31. An illumination device comprising:

a laser diode for emitting a laser light having a peak wave length of 360 nm to 420 nm; and

a phosphor film which is formed by mixing a phosphor for emitting blue light, a phosphor for emitting green light and a phosphor for emitting red light when the phosphors are excited by the laser light, wherein a visible light is obtained by radiating the laser light to the phosphor film.

38. The illumination device according to claim 31, wherein said phosphor for emitting the blue light has at least one composition expressed by general formulas:

(Sr_1-x-y-zBa_xCa_yEu_z)₅(PO₄)₃Cl

wherein x, y and z respectively satisfy the relations x, y<

0.3 and 0.001<

z<

0.2; and

(Ba_1-x, Eu_x)MgAl₁₀O₁₇

wherein x satisfies the relation 0.01<

x<

0.3.

39. The illumination device according to claim 31, wherein said phosphor for emitting the green light has at least one composition expressed by general formulas:

(Ba_1-x, Eu_x) (Mg_1-y, Mn_y)Al₁₀O₁₇

wherein x and y respectively satisfy the relations 0.05<

x<

0.5, and 0.1<

y<

0.6;

(Sr_2-x-y-z-ω

, Ba_xMg_yMn_z, Eu_ω

)SiO₄

wherein x, y, z andco respectively satisfy the relations 0.05<

x<

1, 0≦

y<

0.2, 0≦

z<

0.009, 0.03<

ω

<

0.3;

ZnS;

Au_x, Al_y

wherein x and y respectively satisfy the relations 0.002≦

x≦

0.015, 0.0001≦

y≦

0.0012;

(Sr_1-x-y, Ca_x, Eu_y)Ga₂S₄

wherein x and y respectively satisfy the relations x<

0.2, 0.05 <

y<

0.3; and

(Sr_3-xEu_x)Si_yAl_zO_vN_ω

wherein x, y, z, v andw respectively satisfy the relations x<

0.2, 12 <

y <

14, 2 <

z<

4, 1<

v<

3, 20<

ω

<

22.

40. The illumination device according to claim 31, wherein said phosphor for emitting the red light has at least one composition expressed by general formulas:

(La_1-x, Eu_xSm_y)₂O₂S

wherein x and y respectively satisfy the relations 0.01<

x<

0.2 and 0≦

y≦

0.2; and

(Ca_1-x, Eu_x)AlSiN₃

wherein x satisfies the relation 0.005<

x<

0.03.