(12) United States Patent
`Fujiwara et al.
`
`USOO6680568B2
`(10) Patent No.:
`US 6,680,568 B2
`(45) Date of Patent:
`Jan. 20, 2004
`
`(54) LIGHT SOURCE
`(75) Inventors: Tsubasa Fujiwara, Tokyo (JP); Akio
`Nakano, Tokyo (JP)
`(73) Assignee: Nippon Leiz Corporation, Tokyo (JP)
`
`(*) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 104 days.
`(21) Appl. No.:
`09/937,847
`(22) PCT Filed:
`Feb. 9, 2001
`(86) PCT No.:
`PCT/JP01/00930
`S371 (c)(1),
`(2), (4) Date: Nov. 6, 2001
`(87) PCT Pub. No.: WO01/59851
`PCT Pub. Date: Aug. 16, 2001
`Prior Publication Data
`US 2002/0153835 A1 Oct. 24, 2002
`Foreign Application Priority Data
`(30)
`Feb. 9, 2000 (JP) ....................................... 2000-032116
`Nov. 15, 2000 (JP) ....................................... 2000-348383
`(51) Int. Cl.................................................... H01J 1/62
`(52) U.S. Cl. ........................................ 313/501; 313/512
`(58) Field of Search ................................. 313/501, 512;
`257/98, 99, 100
`
`(65)
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`6,060,729 A 5/2000 Suzuki et al. ................. 251/99
`FOREIGN PATENT DOCUMENTS
`60-261181
`12/1985
`JP
`30483.68
`2/1998
`JP
`10-151794
`6/1998
`JP
`10-308534
`11/1998
`JP
`11-68166
`3/1999
`JP
`11-87772
`3/1999
`JP
`11-O87778
`3/1999
`JP
`11-121804
`4/1999
`JP
`11-163419
`6/1999
`JP
`2000-22222
`1/2000
`JP
`2000-31530
`1/2000
`JP
`* cited by examiner
`Primary Examiner Renee Luebke
`Assistant Examiner Ann McCamey
`(74) Attorney, Agent, or Firm- Kanesaka & Takeuchi
`(57)
`ABSTRACT
`A light emitting device effectively utilizes the light emanat
`ing from a Semiconductor luminous element, and can
`acquire clear and high-luminance light emission without a
`color dapple. The light emitting device is configured as
`follows. A transparent resin containing a wavelength con
`Verting material is provided on a reflecting Surface of a base
`member Such as a case, a board and a lead frame. The
`transparent Semiconductor luminous element is bonded and
`fixed on the transparent resin. A wavelength of light emitted
`from a lower Surface of the Semiconductor luminous element
`is converted by the wavelength converting material, and the
`converted light is reflected on the reflecting Surface. The
`reflected light is mixed with light emitted from an upper
`Surface of the Semiconductor luminous element, and the
`mixed light is radiated.
`
`4.942,504 A
`
`7/1990 Brotz .......................... 362/84
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`13 Claims, 17 Drawing Sheets
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`Nichia Exhibit 1005
`Page 1
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`

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`U.S. Patent
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`Jan. 20, 2004
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`Sheet 1 of 17
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`US 6,680,568 B2
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`FG1
`
`
`
`
`
`
`
`Y
`
`...'
`
`/
`
`-
`
`uparate
`A
`
`-
`
`M
`
`r
`
`4.
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`Nichia Exhibit 1005
`Page 2
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`

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`U.S. Patent
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`Jan. 20, 2004
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`Sheet 2 of 17
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`US 6,680,568 B2
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`FG3
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`Nichia Exhibit 1005
`Page 3
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`

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`U.S. Patent
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`Jan. 20, 2004
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`Sheet 3 of 17
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`US 6,680,568 B2
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`FG. 4
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`CONVENTIONAL TYPE IN THIS
`TYPE
`EMBODMENT
`LUMNOUS
`LUMNOUS
`INTENSTY
`INTENSTY
`(mcd)
`(mCd)
`
`3
`
`1
`
`
`
`
`
`
`
`NOO1
`
`p
`
`
`
`
`
`No.11 ||
`
`512
`
`000
`
`
`
`
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`Nichia Exhibit 1005
`Page 4
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`U.S. Patent
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`Jan. 20, 2004
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`Sheet 4 of 17
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`US 6,680,568 B2
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`FG.5
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`Page 5
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`U.S. Patent
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`Jan. 20, 2004
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`Sheet 5 of 17
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`US 6,680,568 B2
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`F.G. 6
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`C
`
`Y 22b.
`22a) 4 (
`22 (NN
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`- 14
`
`
`
`FG.7
`
`Y- ---
`
`5 -
`
`2(2a)
`\
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`-
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`2 (2b)
`-/
`
`
`
`
`
`FG8
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`
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`Nichia Exhibit 1005
`Page 6
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`U.S. Patent
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`Jan. 20, 2004
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`Sheet 6 of 17
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`US 6,680,568 B2
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`FG.9
`
`el-Gu?es
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`- 7(11)
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`7a (11a)
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`FG 1 O
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`
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`
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`2(2a)
`N
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`
`
`SSGS
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`N NY
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`
`
`3
`
`9
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`Nichia Exhibit 1005
`Page 7
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`U.S. Patent
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`Jan. 20, 2004
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`Sheet 7 of 17
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`US 6,680,568 B2
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`FIG 11
`
`a(11a)
`
`2(2b)
`
`- 7(11)
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`
`
`
`
`
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`a(11a)
`
`3
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`Nichia Exhibit 1005
`Page 8
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`Jan. 20, 2004
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`U.S. Patent
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`Jan. 20, 2004
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`Sheet 9 of 17
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`US 6,680,568 B2
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`FG, 14
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`
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`21 21 a
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`21b 21
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`7
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`Nichia Exhibit 1005
`Page 10
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`U.S. Patent
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`Jan. 20, 2004
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`Sheet 10 Of 17
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`Jan. 20, 2004
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`Sheet 11 Of 17
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`US 6,680,568 B2
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`Jan. 20, 2004
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`Sheet 12 Of 17
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`Jan. 20, 2004
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`Sheet 13 Of 17
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`U.S. Patent
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`Jan. 20, 2004
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`Sheet 14 Of 17
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`US 6,680,568 B2
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`U.S. Patent
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`Jan. 20, 2004
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`Sheet 15 Of 17
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`US 6,680,568 B2
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`Jan. 20, 2004
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`Sheet 16 0f 17
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`US 6,680,568 B2
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`\, ,
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`U.S. Patent
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`Jan. 20, 2004
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`Sheet 17 of 17
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`

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`US 6,680,568 B2
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`1
`LIGHT SOURCE
`
`BACKGROUND OF THE INVENTION AND
`RELATED ART STATEMENT
`The present invention relates to a light emitting device
`used for a light Source of a liquid crystal display and others.
`Particularly, the present invention relates to a light emitting
`device wherein clear and high-luminance emission without
`a color dapple can be acquired effectively utilizing the light
`emanating from a Semiconductor luminous element for a
`long term.
`Alight emitting diode which is a Semiconductor luminous
`element is a Small device. Clear luminescent color can be
`efficiently acquired without anxiety that a light bulb is
`burnt-out. The light emitting diode has an excellent drive
`characteristic and is also strong against a vibration and
`repetitive Switching operations. Therefore, the light emitting
`diode is utilized for a light Source of various indicators and
`a liquid crystal display.
`Heretofore, as a light emitting device of a liquid crystal
`display and others for displaying full color, a light emitting
`diode (LED) lamp is known. The LED lamp has semicon
`ductor luminous elements emitting colors of red, blue and
`green, that is, three Semiconductor luminous elements of So
`called RBG. The three semiconductor luminous elements
`are provided on a board as one unit.
`Another type of full color light emitting device is also
`known. The full color light emitting device has three Semi
`conductor luminous elements emitting colors of red, blue
`and green provided on a lead frame.
`A light emitting diode used for this type of light emitting
`device has an excellent monochromatic peak wavelength.
`Therefore, in case that a light emitting device that emits
`white light is utilizing light emitting diodes that respectively
`emit red light, green light and blue light, for example, the
`light emitting diodes that respectively emit each color light
`are required to be arranged closely to diffuse and mix each
`color light.
`Concretely, to acquire a light emitting device that emits
`white light, three types of red, green and blue light emitting
`diodes or two types of bluish green and yellow light emitting
`diodes are required. That is, to acquire a light emitting
`device that emits white light, light emitting diodes of plural
`types different in luminescent colors are required to be used.
`In addition, a Semiconductor light emitting diode chip has
`fluctuations in tone and luminance. In case that plural light
`emitting diodes are made of different materials, the driving
`power of each light emitting diode chip is different and a
`power Source is required to be individually Secured.
`Therefore, to acquire the white light, a current Supplied to
`every light emitting diode and others are required to be
`adjusted. There is a problem that a light emitting diode is
`different in temperature and aging characteristics, and tone
`also changes. Further, in case that the emission from each
`light emitting diode chip is not mixed uniformly, the light
`may include irregular color and desired white color may not
`be acquired.
`Particularly, in the light emitting device wherein three
`types of Semiconductor luminous elements of red, blue and
`green luminescent colors are provided on a board and are
`used as one unit, there is a problem that the light emitting
`device becomes large. In addition, as there is a distance
`between the Semiconductor luminous elements, there is a
`problem that it is difficult to acquire uniform mixed color,
`and the color of the light emitting device becomes coarse.
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`In the light emitting device in which three types of
`Semiconductor luminous elements of red, blue and green
`luminescent colors are provided on one lead frame and the
`like, to acquire the white luminescent color, charge is
`required to be Supplied to all Semiconductor luminous
`elements including red, blue and green. Therefore, there are
`a problem of large power consumption in View of energy
`conservation and a problem of a Space required for a battery
`in a portable (mobile) type.
`AS a light emitting device in which the above-mentioned
`problems are Solved, a light emitting device disclosed in
`Japanese published unexamined patent applications No. Hei
`7-99345, No. Hei 10-190066 and No. Hei 10-242513 is
`known.
`In the light emitting device disclosed in Japanese pub
`lished unexamined patent application No. Hei 7-99345, an
`LED chip is mounted at the bottom of a cup. A resin (a color
`converting member) including a fluorescent material (or a
`filter material for partially absorbing the emission wave
`length of the luminous chip) for converting the emission
`wavelength of the LED chip to another wavelength is filled
`inside the cup. Further, another resin is provided for Sur
`rounding the above-mentioned resin.
`The light emitting device disclosed in Japanese published
`unexamined patent application No. Hei 10-190066 is pro
`vided with an LED chip fixed on a board by a die bonding
`member and a color converting member provided on the
`LED chip. The color converting member includes a fluo
`rescent material that absorbs at least a part of light emitted
`from the LED chip, converts the wavelength and emits the
`converted light.
`In a light emitting device disclosed in Japanese published
`unexamined patent application No. Hei 10-242513, a pair of
`mount-leads is provided in the light emitting device. A front
`edge of one of the mount-leads is in the form of a cup. An
`LED chip made of a gallium nitride Semiconductor is
`arranged in the cup. The LED chip is electrically connected
`via an inner lead with the other mount-lead. A transparent
`resin including a fluorescent material is filled in the cup. In
`another light emitting device, a gallium nitride Semiconduc
`tor chip is arranged in the body of the equipment and a
`transparent resin including a fluorescent material is filled in
`the body.
`The light emitting device disclosed in the above
`mentioned each patent application acquires another lumi
`neScent color from one type of luminescent color of a
`Semiconductor luminous element itself. Concretely, as a
`light emitting diode that converts the wavelength of light
`emitted from an LED chip, white light emission is acquired
`by mixing light emitted from a blue light emitting diode and
`light emitted from a fluorescent material that absorbs the
`above-mentioned light and emits yellow light.
`In the light emitting devices disclosed in the above
`mentioned patent applications, the color converting member
`is provided on the LED chip. Therefore, in case that the
`white light is acquired, the dispersed blue light radiated
`upward from the LED chip itself and yellow light converted
`by the color converting member provided on the LED chip
`are mixed to look white light to a human eye.
`To acquire clear and high-luminance white light, Scatter
`ing and distribution of blue light and yellow light are
`required to be uniform and constant. However, in the con
`figuration disclosed in the above-mentioned each patent
`application, the blue light is shielded by the color converting
`member on the LED chip. Luminance of the light emitting
`device is determined by a quantity of the light converted by
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`3
`the color converting member and the blue light radiated
`from the LED chip itself. Therefore, there is a problem that
`the Scattering and the distribution of the color converting
`member are required to be uniform, and luminance is not
`Satisfactory.
`In addition to the color converting member including a
`fluorescent material for converting the wavelength of the
`light from the LED chip, a die bonding member (a mounting
`member) for fixing the luminous chip or the LED chip is
`required.
`Further, the configuration disclosed in Japanese published
`unexamined patent application No. Hei7-99345 has a prob
`lem that Since the Semiconductor luminous element is put in
`the wavelength converting material, it is difficult to acquire
`mixed color.
`Also, in the configuration disclosed in Japanese published
`unexamined patent application No. Hei 10-242513, the
`gallium nitride Semiconductor is arranged in the cup or the
`body of equipment. The fluorescent material Such as a
`wavelength converting material is filled above the Semicon
`ductor and at the four sides. Hereby, the fluorescent material
`is uniformly dispersed in the transparent resin. In addition,
`there is a problem that it is difficult to control a dispersed
`quantity and a thickness at the four Sides, and a dispersed
`quantity and a thickness above the Surface. In addition to the
`configuration disclosed in the above-mentioned each patent
`application, there is also known another configuration. In the
`configuration, a blue light emitting Semiconductor luminous
`element is enveloped in a shape of a lamp by the whole resin
`including a wavelength converting material. Hereby, white
`luminescent color can be acquired by the Semiconductor
`luminous element lamp by converting the wavelength of
`light emitted from the Semiconductor luminous element to
`another wavelength.
`However, in the above-mentioned configuration, a quan
`tity of the wavelength converting material is increased and
`the configuration has a problem in the Stability of the
`Scattering and the distribution of the wavelength converting
`material.
`AS described above, the light emission acquired in the
`case of the above-mentioned conventional type light emit
`ting device is not enough as a light Source for the liquid
`crystal display and others. Therefore, high-luminance light
`emission (particularly, white light emission) for a long term
`has been desired.
`The invention is made to solve the above-mentioned
`problems. The invention has an object of effectively utilizing
`the light emanating from a Semiconductor luminous element
`and acquiring clear and high-luminance light emission with
`out a color dapple. The invention also has an object of
`providing light emitting device that enables acquiring high
`luminance light emission for a long term compared with the
`conventional type.
`SUMMARY OF THE INVENTION
`A configuration of the invention to achieve the objects
`will be described below. A light emitting device according to
`the invention is provided on a reflecting Surface of a base
`member (a board having reflectivity, a lead frame, and a
`pattern having reflectivity or an electric wiring pattern in a
`case), and includes a transparent resin in which a wavelength
`converting material is mixed and a transparent Semiconduc
`tor luminous element provided on the transparent resin. In
`the light emitting device, a wavelength of light emitted from
`a lower Surface of the Semiconductor luminous element is
`converted by the wavelength converting material, and the
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`4
`light with the converted wavelength is reflected on the
`reflecting Surface. The reflected light and light directly
`emitted from an upper Surface of the Semiconductor lumi
`nous element are mixed, and the mixed light is radiated from
`the upper Surface of the Semiconductor luminous element.
`According to the light emitting device, light radiated
`downward from the lower Surface of the semiconductor
`luminous element is reflected upward as the light with the
`wavelength converted by the wavelength converting mate
`rial in the transparent resin. Hereby, the reflected light and
`light directly radiated from the Semiconductor luminous
`element are completely mixed, and uniform light can be
`radiated upward from the upper Surface of the Semiconduc
`tor luminous element.
`A conductive material may be further mixed in the
`transparent resin in addition to the wavelength converting
`material. When the Semiconductor luminous element is
`bonded and fixed on the transparent resin, Static electricity
`can be prevented from being electrified in the Semiconductor
`luminous element itself.
`The light emitting device according to a third aspect is
`characterized in that the transparent resin is formed in an
`area larger than an area of the Semiconductor luminous
`element on the base member, and the Semiconductor lumi
`nous element is bonded and fixed on the transparent resin on
`the base member.
`According to the light emitting device, the light radiated
`downward from the lower Surface of the semiconductor
`luminous element is reflected upward as the light with the
`wavelength converted by the wavelength converting mate
`rial in the transparent resin. Further, light radiated downward
`from four sides of the Semiconductor luminous element is
`reflected Substantially upward as light with the wavelength
`converted by the wavelength converting material in the
`transparent resin provided in the area larger than the area of
`the Semiconductor luminous element. The reflected light and
`light directly radiated from the Semiconductor luminous
`element are completely mixed. Hereby, the uniform light can
`be radiated upward. The transparent resin is provided in the
`area larger than the area of the Semiconductor luminous
`element. Hereby, when the wavelength converting material
`mixed in the transparent resin is applied or printed at a fixed
`and uniform thickness, mixed whole tone can be controlled
`not by the thickness but by the area. In addition, the
`transparent resin also functions as an adhesive and can fix
`the Semiconductor luminous element.
`A light emitting device according to a fourth aspect is
`characterized in that a concave portion is provided in the
`base member. The transparent resin is filled in the concave
`portion, and the Semiconductor luminous element is bonded
`and fixed on the transparent resin filled in the concave
`portion.
`According to the light emitting device, high-luminance
`light emission can be acquired, compared with a conven
`tional type case that a transparent resin in which a fluores
`cent material is mixed is provided on a Semiconductor
`luminous element. In addition, the Semiconductor luminous
`element is bonded and fixed by the transparent resin filled in
`the concave portion. Therefore, the transparent resin also
`functions as an adhesive, So that it is possible to enhance and
`converge the light with the converted wavelength to be
`returned to the Semiconductor luminous element.
`A light emitting device according to a fifth aspect is
`characterized in that an aperture area of the concave portion
`is Smaller than an area of the lower Surface of the Semicon
`ductor luminous element.
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`According to the light emitting device, the direct light
`from the Semiconductor luminous element and the light with
`the converted wavelength can be efficiently emitting outside.
`A light emitting device according to a sixth aspect is
`characterized in that an inner wall of the concave portion
`faces the Sides of the Semiconductor luminous element and
`has an inclined face extending from the bottom to the
`aperture.
`According to the light emitting device, the light radiated
`downward from the lower Surface of the semiconductor
`luminous element is reflected upward as the light with the
`wavelength converted by the wavelength converting mate
`rial in transparent resin. Further, the light is radiated from the
`four Sides of the Semiconductor luminous element Sideway
`and downward. The radiated light is securely reflected
`Substantially upward as the light with the wavelength con
`verted by the wavelength converting material in the trans
`parent resin formed on the inclined face at each position
`corresponding to the four Sides of the Semiconductor lumi
`nous element. The reflected light and light radiated directly
`from the Semiconductor luminous element are completely
`mixed. Hereby, the uniform light can be radiated upward.
`A light emitting device according to a Seventh aspect is
`characterized in that an angle between the inclined face of
`the concave portion and the bottom of the concave portion
`is between 0 and 45.
`According to the light emitting device, the light emanat
`ing Sideway from the four Sides of the Semiconductor
`luminous element is reflected Substantially upward. The
`light emanating slightly diagonally downward is reflected
`upward Substantially toward inside of the Semiconductor
`luminous element. The light emanating Slightly diagonally
`upward is reflected upward toward outside of the Semicon
`ductor luminous element. Therefore, the light emanating
`from the four Sides of the Semiconductor luminous element
`can be effectively utilized.
`A shape of the aperture of the concave portion in the light
`emitting device may be rectangular or circular depending
`upon a shape of the Semiconductor luminous element.
`Hereby, the light from the lower surface of the semiconduc
`tor luminous element can be effectively projected onto the
`concave portion, and the machining is also easy.
`In case that the concave portion is machined by etching,
`a laser beam or electric discharge, it is possible to precisely
`form the aperture in a Small shape with good reflection
`efficiency. Therefore, the concave portion Smaller than the
`Size of the lower Surface of the Semiconductor luminous
`element can be provided.
`The Semiconductor luminous element may be also bonded
`and fixed on the transparent resin Via a transparent adhesive.
`In this case, it is desirable that the Semiconductor luminous
`element has an active layer arranged on a transparent Sub
`Strate and a transparent electrode is provided on the active
`layer.
`The base member used in the light emitting device may be
`a ceramic board, a liquid crystal polymer resin board and a
`glass fiber epoxy resin board, a lead frame and a case having
`reflectivity. Hereby, independent of a place and a material,
`the Semiconductor luminous element is bonded and fixed
`anywhere and arbitrary mixed light Such as white light can
`be acquired.
`The semiconductor luminous element may be formed of
`InGaAlP, InCaAlN, InCaN or GaN. Hereby, the desired
`mixed light can be acquired depending upon a combination
`with the wavelength converting material mixed in the trans
`parent resin.
`
`6
`In the light emitting device according to the invention, if
`the wavelength converting material mixed in the transparent
`resin is evenly distributed without being dispersed two
`dimensionally, the light emanating from the Semiconductor
`luminous element can be further effectively utilized, com
`pared with the conventional type configuration in which the
`transparent resin with the fluorescent material is filled on the
`Semiconductor luminous element at random.
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`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a general drawing showing a first embodiment
`of a light emitting device according to the invention;
`FIG. 2 is a side sectional view of FIG. 1;
`FIG. 3 Shows a configuration of a Semiconductor lumi
`nous element;
`FIG. 4 shows a result of the comparison in measured
`luminous intensities between a conventional type configu
`ration in which a transparent resin with a fluorescent mate
`rial is provided on a Semiconductor luminous element and a
`configuration according to the invention (light emitting
`device of the first embodiment) in which a transparent resin
`with a fluorescent material is bonded and fixed under a
`Semiconductor luminous element or a Semiconductor lumi
`nous element is mounted (bonded) on a transparent resin
`with a fluorescent material;
`FIG. 5 is a general drawing showing a Second embodi
`ment of the light emitting device according to the invention;
`FIG. 6 is a partial sectional view showing a third embodi
`ment of the light emitting device according to the invention;
`FIG. 7 is a partial sectional view showing a fourth
`embodiment of the light emitting device according to the
`invention;
`FIG. 8 is a partial sectional view showing a modified
`example of the light emitting device of the fourth embodi
`ment,
`FIG. 9 is a general drawing showing a fifth embodiment
`of the light emitting device according to the invention;
`FIG. 10 is a partial sectional view showing a sixth
`embodiment of the light emitting device according to the
`invention;
`FIG. 11 is a partial sectional view showing a seventh
`embodiment of the light emitting device according to the
`invention;
`FIG. 12 is a partial sectional view showing a modified
`example of the light emitting device according to the inven
`tion;
`FIG. 13 is a partial sectional view showing an eighth
`embodiment of the light emitting device according to the
`invention;
`FIGS. 14(a) to 14(c) are front views showing concave
`portions provided in a lead frame or a board formed by
`injection molding in the light emitting device equivalent to
`the eighth embodiment;
`FIG. 15 is a perspective view showing a ninth embodi
`ment of the light emitting device according to the invention;
`FIG. 16 is a partial side sectional view showing the light
`emitting device according to the ninth embodiment;
`FIG. 17 is a partial sectional view showing a tenth
`embodiment of the light emitting device according to the
`invention and is a Side Sectional view showing the light
`emitting device where an inclined face is provided in a lead
`frame, a board or a case;
`FIG. 18 shows a path of light reflected on a reflecting
`Surface after a wavelength is converted by a wavelength
`
`Nichia Exhibit 1005
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`7
`converting material in a transparent resin in the configura
`tion of the tenth embodiment of the light emitting device
`according to the invention;
`FIG. 19 is a partial side sectional view showing an
`eleventh embodiment of the light emitting device according
`to the invention;
`FIG. 20 is a partial side sectional view showing a modi
`fied example of the light emitting device of the eleventh
`embodiment;
`FIG. 21 is a partial side sectional view showing a twelfth
`embodiment of the light emitting device according to the
`invention; and
`FIG. 22 is a partial Side Sectional view showing a modi
`fied example of the light emitting device of the twelfth
`embodiment.
`
`15
`
`DETAILED DESCRIPTION OF PREFERRED
`EMBODIMENTS
`
`Embodiment 1
`Referring to the attached drawings, the invention will be
`described in more detail below.
`A light emitting device according to the invention
`described below is using a transparent InCaAlP, InCaAlN,
`InGaN or GaN semiconductor luminous element. The semi
`conductor luminous element is mounted on a reflective lead
`frame, a reflective board or a reflective pattern and a
`reflective electric wiring pattern through a transparent resin
`in which a wavelength converting material is mixed.
`FIG. 1 is a general drawing showing a first embodiment
`of the light emitting device according to the invention. FIG.
`2 is a side sectional view of FIG. 1.
`A light emitting device 1 (1A) equivalent to the first
`embodiment shown in FIGS. 1 and 2 is formed by injection
`moulding or transfer moulding. This light emitting device
`1A is Substantially composed of a pattern 2 (2a, 2b), a
`transparent resin 3, a Semiconductor luminous element 4,
`bonding wires (hereinafter called wire) 5, lead terminals 6
`(6a, 6b) and a molding case (hereinafter called a case) 7. The
`pattern 2 in this embodiment also includes an electric wiring
`pattern.
`The pattern 2 (2a, 2b) is formed on a lead frame having
`a predetermined pattern form and made of phosphor bronze
`and others. The case 7 made of a resin is inserted into the
`lead frame.
`The transparent resin 3 is acquired by mixing the wave
`length converting material Such as an inorganic fluorescent
`pigment and organic fluorescent dye in a transparent and
`colorless epoxy resin and others. In case that the fluorescent
`material (YAG) is mixed in the epoxy resin, for example, the
`weight ratio of the epoxy resin and the fluorescent material
`is approximately 1:3 to 1:4. This transparent resin 3 can be
`formed on the pattern 2 as a printed pattern by applying on
`the pattern 2 or by printing fluorescent material mixed ink
`and others.
`The transparent resin 3 is provided between the pattern 2
`exposed at the bottom in a concave portion 7a of the case 7
`and the lower Surface 4a (the Surface without an electrode)
`of the Semiconductor luminous element 4. In the example
`shown in FIGS. 1 and 2, the transparent resin 3 is provided
`in an area Substantially similar to the lower Surface 4a of the
`Semiconductor luminous element 4. This transparent resin 3
`also functions as an adhesive cement for Sticking the Semi
`conductor luminous element 4 on the pattern 2.
`Further, in case that a Semiconductor luminous element
`that emits blue light is used for the Semiconductor luminous
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`US 6,680,568 B2
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`element 4, the transparent resin 3 is formed of a resin in
`which a wavelength converting material including an orange
`fluorescent pigment or an orange fluorescent dye Such as
`Yttrium-Aluminum-Garnet (YAG) including CaSiO:Pb,
`Mn and (Y, Gd)(Al, Ga),O is mixed. Hereby, yellow light
`is acquired by projecting the blue light from the Semicon
`ductor luminous element 4 onto the resin in which the
`wavelength converting material including the orange fluo
`rescent pigment or the orange fluorescent dye is mixed.
`When the yellow light acquired by color conversion by the
`wavelength converting material in the transparent resin 3
`and the blue light radiated by the Semiconductor luminous
`element 4 itself are mixed, light radiated upward from the
`upper Surface 4b of the Semiconductor luminous element 4
`itself becomes white light.
`Also, in case that a Semiconductor luminous element that
`emits green light, for example, is used for the Semiconductor
`luminous element 4, the transparent resin 3 is formed of a
`resin in which a wavelength converting material including a
`red fluorescent pigment or a red fluorescent dye is mixed.
`Hereby, yellow light is acquired by projecting the green light
`from the Semiconductor luminous element 4 onto the resin
`in which the wavelength converting material including the
`red fluorescent pigment or red fluorescent dye is mixed.
`Further, in case that the transparent resin 3 is formed of a
`resin in which a wavelength converting material including a
`green fluorescent pigment or a green fluorescent dye is
`mixed, when a Semiconductor luminous element that emits
`the blue light is used for the Semiconductor luminous
`element 4, bluish green light is acquired by projecting the
`blue light from the Semiconductor luminous element 4 onto
`the resin in which the wavelength converting material
`including the green fluorescent pigment or the green fluo
`rescent dye is mixed.
`The transparent resin 3 may be Such a resin acquired by
`mixing a wavelength converting material including an inor
`ganic fluorescent pigment or an organic fluorescent dye and
`others and a conductive material in the transparent and
`colorless epoxy resin.
`The conductive material in this case is mixed at a limit at
`which a filler Such as a Silver particle does not have a
`negative effect upon the fluorescent material. The conduc
`tive material has a high resistance value at a degree at which
`the positive electrode and the negative electrode of the
`Semiconductor luminous element 4 itself are not short
`circuited at a low charge.
`Even if potential Static electricity and others higher than
`an applied Voltage are electrified in the whole Semiconductor
`luminous element 4, the Static electricity and others are
`made to flow to the ground by adding a Small amount of the
`conductive material in the case of the Semiconductor lumi
`nous element 4 with high charge. Hereby, the InGaAlP,
`InGaAlN, InCaN or GaN semiconductor luminous element
`4 itself which is sensitive to the static