JP2003031856A - Light emitting device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide LE with a resin mixed with a fluorescent dye or a fluorescent pigment.
Since the D chip is sealed and fluorescent light is emitted from the resin lens, there are problems such as deterioration of transparency, decrease of luminance, and color unevenness. An LED that emits light that excites a fluorescent material is provided.
The LED chip 3 was provided with a chip 3 and a lens 1 formed of fluorescent glass that emits fluorescence with light from the LED chip 3. The LED chip 3 was housed in a hollow portion 8 containing an inert gas in the lens 1 and sealed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device in which an LED chip is sealed with a lens made of fluorescent glass and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, for example, a blue LED chip is sealed with a resin containing a fluorescent dye or fluorescent pigment as a color conversion material,
The light from the blue LED chip is used as excitation light to emit fluorescence from the fluorescent dye or fluorescent pigment to obtain light other than blue,
It is being done to obtain a color mixture with blue.

[0003]

However, many organic resins are used as the resin. However, this organic resin causes deterioration in transparency during high temperature operation or ultraviolet irradiation, and also absorbs light. There was a problem that the emission intensity (luminance) was lowered, and because it had hygroscopicity, it was difficult to use it outdoors in the rain.

Further, even if the LED chip is sealed by potting with a resin mixed with a fluorescent dye or fluorescent pigment and light is emitted through the resin lens, a resin lens is formed with a resin mixed with the fluorescent dye or fluorescent pigment to emit light. Even if
Since the fluorescent dye and the fluorescent pigment are mixed in the resin as small particles to disperse the light, the entire resin lens does not emit light, which causes a problem that color unevenness occurs.

[0005]

In order to solve the above problems, the present invention provides an LED that emits light for exciting a fluorescent material.
It is provided with a chip and a lens formed of fluorescent glass that emits fluorescence by the light of the LED chip, the LED chip and the lens are optically coupled, and the LED chip is sealed in the lens.

[0006]

1 is a sectional view showing a first embodiment of the present invention.

Reference numeral 1 is a lens made of, for example, shell-shaped fluorescent glass, 2 is a fluorescent glass plate, 3 is an LED chip, 4
Is a gold wire for bonding, 5 is a lead frame, 6 is a cup, 7 is a lead frame, and 8 is a hollow portion containing an inert gas.

Unlike the conventional resin, the lens 1 is made of fluorescent glass made by doping a glass material with a fluorescent material.

As the fluorescent material, rare earth elements such as 2 can be used.
Valent and trivalent Eu (europium), Tb (terbium), Sm (samarium), Mn (manganese) and Zn (zinc) are also known, and they are used alone or in combination of plural kinds. It

The atoms of these elements are usually in a cation state, and the ions are excited by the light of the LED chip 3,
It is known to emit fluorescence of a color peculiar to ions.

Typical fluorescent glass compositions are as follows. Green fluorescent glass B ₂ O ₃ · CaO · SiO ₂ · La ₂
O _3: ^{Tb 3+} red fluorescent glass _{SiO 2 · B 2 O 3 ·} BaO · Zn
O: Eu ³⁺ blue fluorescent glass P ₂ O ₅ · AlF ₃ · MgF ₂ · Ca
The F ₂ · SrF ₂ · BaCl ₂ : Eu ²⁺ fluorescent glass plate 2 is a plate made of exactly the same fluorescent glass as that forming the lens 1, and is fitted into the lower portion of the lens 1 to form an organic adhesive or Low melting point glass lens 1
To form a hollow portion 8.

The wavelength of the LED chip 3 is not limited as long as it emits light for exciting the fluorescent material, and the fluorescent material can emit fluorescence even with visible light, ultraviolet light, or far infrared light.

The LED chip 3 is a cathode lead frame 7
It is fixed to the cup 6 formed in the above, is connected from the electrode to the lead frame 5 of the anode by the gold wire 4, is mounted on the lead frames 5 and 7, and is sealed by the lens 1.

Now, as a manufacturing method of fluorescent glass, 8 materials are used.
A melting method in which the material is melted at a high temperature of 00 to 1000 ° C. and put into a mold to prepare is common. When the melting method is used, this high temperature exceeds the heat resistant temperature of the LED chip 3.

Therefore, it is necessary to devise a method in which the fluorescent glass lens 1 is not brought into direct contact with the LED chip 3.

Therefore, a hollow portion is formed in the lens 1, and an inert gas such as nitrogen or helium, which is a non-reactive gas, is introduced into the hollow portion 8 and the LED chip 3 is housed and sealed therein. is there.

With this configuration, when the LED chip 3 emits light, the light excites the ions of the fluorescent material, which are doped in the fluorescent glass and uniformly distributed, to emit fluorescence, and the entire lens 1 is illuminated. Fluorescence is emitted.

Explaining the manufacturing method of the first embodiment, the LED chip 3 which emits light for exciting the fluorescent material.
Then, the lead frames 5 and 7 are prepared, the LED chip 3 is fixed to the cup 6, and the LED chip 3 and the lead frame 5 are bonded by the gold wire 4.

On the other hand, a lens 1 is formed by putting fluorescent glass in a mold made to have a cylindrical hollow portion 8, and a disk-shaped fluorescent glass plate 2 is made of fluorescent glass.

The fluorescent glass plate 2 is provided with lead frames 5, 7
A hole for inserting the lead frame is opened, the lead frames 5 and 7 are inserted into the hole, and fixed with an adhesive or the like.

Next, in an inert gas atmosphere, the LED chip 3 and the lead frames 5, 7 are housed in the hollow portion 8, the fluorescent glass plate 2 and the lens 1 are engaged, and the lens 1 and the fluorescent glass plate 2 are connected. With an adhesive or low melting point glass.

As described above, according to the first embodiment, the lens 1 is formed of fluorescent glass without using the organic resin, and
Since the ED chip 3 is sealed, there is no deterioration in transparency due to high temperature operation or irradiation of ultraviolet rays, the decrease in emission intensity is greatly improved, and since it has no hygroscopicity, it can be used outdoors in rainy weather. It can also be used underwater if it is waterproof.

Further, since the ions of the fluorescent material doped in the fluorescent glass are uniformly distributed in the fluorescent glass, the entire fluorescent glass emits light, and the light emitted from the lens 1 does not have color unevenness.

Further, by selecting the ionic species of the fluorescent material to be doped into the fluorescent glass, the light emitted from the LED chip 3 excites the ions to emit a color different from that of the LED chip 3 and the LED chip is emitted. It is also possible to mix colors with the emission colors of 3.

FIG. 2 is a sectional view showing a second embodiment of the present invention, in which a resin is injected into the hollow portion containing the inert gas of the first embodiment.

Reference numeral 11 denotes a lens made of fluorescent glass, and 13
LED chip, 14 gold wire for bonding, 15
Is a lead frame, 16 is a cup, 17 is a lead frame, 18 is resin, and 19 is a stopper.

The resin 18 is a cylindrical transparent resin such as epoxy or a fluorescent resin obtained by doping the transparent resin with the fluorescent material described in the first embodiment, and the stopper 19 is the resin 18.
It is formed in a brim shape or a plurality of projection shapes on the circumferential portion of, and functions to hold the engagement between the lens 11 and the resin 18.

Since the melting temperature of the resin 18 is low, L
It does not affect the ED chip 13.

With this structure, when the LED chip 13 emits light, if the resin 18 is a transparent resin,
The light is transmitted, the fluorescent glass of the lens 11 is doped, and the ions of the fluorescent material uniformly distributed are excited to emit fluorescence, and the entire lens 11 emits fluorescence.

When the resin 18 is a fluorescent resin, a part of the light of the LED chip 13 excites the fluorescent material ions in the fluorescent resin to emit fluorescence, and the other transmits light to allow the fluorescent glass in the lens 11 to pass through. The lens 11 is excited by exciting ions to emit fluorescence.
Fluorescence is emitted from the whole of.

The manufacturing method of the first embodiment has a restriction that it must be assembled in an atmosphere of an inert gas, but the manufacturing method of the second embodiment eliminates this restriction.

The manufacturing method of the second embodiment will be described.
An LED chip 13 that emits light that excites a fluorescent material and lead frames 15 and 17 are prepared, the LED chip 13 is fixed to a cup 16, and the LED chip 13 and the lead frame 15 are bonded by a gold wire 14.

On the other hand, the lens 11 is formed by putting the fluorescent glass in a mold made to have a cylindrical hollow portion having a concave portion which becomes the stopper 19.

The LED chip 13 and the lead frame 15,
17 is housed in the hollow portion, and the LED chip 13 and the periphery of the lead frames 15 and 17 are tightly sealed with a transparent resin or a fluorescent resin.

As described above, according to the second embodiment, since the lens 11 is formed of fluorescent glass, color unevenness of the light emitted from the lens 11 is prevented as in the first embodiment. .

Further, the deterioration of the transparency and the decrease of the emission intensity are caused by
Although a transparent resin or a fluorescent resin is used as the resin 18, since the amount of the resin is small, it is significantly improved as compared with the conventional one.

Regarding the hygroscopicity, it exists because the bottom of the resin 18 is exposed. However, it is much less than that of the conventional lens in which the entire lens absorbs moisture. Sex is improved.

Further, when the resin 18 is a fluorescent resin, LE
In addition to the emission color of the D chip 13, the other colors emitted from the fluorescent resin and the other colors emitted from the fluorescent glass of the lens 11
It is possible to mix colors.

While the manufacturing method of the first embodiment is restricted in that it is carried out in an atmosphere of an inert gas, the manufacturing method of the second embodiment is advantageous in that it can be carried out in the atmosphere. .

FIG. 3 is a sectional view showing a third embodiment of the present invention. 21 is a lens made of fluorescent glass, 23 is an LED chip, 24 is a gold wire for bonding, 25 is a lead frame, 26 is a cup, and 27 is a lead frame.

Fluorescent glass is generally 800 to
It is produced at a high temperature of 1000 ° C., but recently, a sol-gel method that can be produced at a relatively low temperature has been proposed.

The sol-gel method is a method of producing glass by using various metal alkoxides as starting materials and utilizing the hydrolysis and dehydration condensation reactions of the starting materials. Compared with the conventional melting method, this allows glass synthesis at a relatively low temperature, and various kinds of rare earth ions can be added to obtain fluorescent glass of each color.

Since the sol-gel method starts from a solution state,
It also has the advantage that it can be molded into complex shapes and has high uniformity.

If a sol-gel method capable of producing fluorescent glass at a low temperature is used, as shown in FIG. 3, the LED chip 23 is sealed by a lens 21 formed of fluorescent glass in close contact with the LED chip 23. can do.

As the manufacturing method of the third embodiment, the LED chip 23 that emits light for exciting the fluorescent material and the lead frames 25 and 27 are prepared, the LED chip 23 is fixed to the cup 26, and the LED chip 23 and Lead frame 2
5 is bonded by a gold wire 24, the LED chip 23 and the lead frames 25 and 27 are put in a mold, and the periphery thereof is closely adhered and sealed by a lens 21 formed of fluorescent glass.

As described above, according to the third embodiment, the same effect as that of the first embodiment is obtained.

[0047]

As described above, according to the present invention, since the lens is formed of the fluorescent glass, the fluorescent glass as a whole emits light to prevent color unevenness, and the transparency is deteriorated, the emission intensity is lowered, and the hygroscopic property is reduced. Significantly improved compared to the past.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the present invention.

[Explanation of symbols]

1,11,21 lens 2 Fluorescent glass plate 3,13,23 LED chip 5,15,25 Lead frame 7,17,27 Lead frame 18 resin 19 stopper

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshihiro Kato             2-46-3 Sangenjaya, Setagaya-ku, Tokyo Okaya             Electric Machinery Industry Co., Ltd.Tokyo Office F-term (reference) 4H001 CF01 XA63 XA65                 5F041 AA11 CB36 DA07 DA12 DA19                       DA61 DA77 DB01 EE11 EE25

Claims (12)

[Claims] 1. An LED that emits light that excites a fluorescent material.
The LED chip and the lens are optically coupled to each other, and the LED chip and the lens are optically coupled to each other.
An ED chip is a light emitting device characterized by being sealed in the lens. 2. The light emitting device according to claim 1, wherein the LED chip is housed and sealed in a hollow portion containing an inert gas in the lens. 3. The light emitting device according to claim 2, wherein the hollow portion is formed of the lens and a fluorescent glass plate. 4. The light emitting device according to claim 1, wherein the LED chip is sealed with a transparent resin or a fluorescent resin, and the periphery thereof is sealed with the lens. 5. The light emitting device according to claim 4, wherein the transparent resin or the fluorescent resin is provided with a stopper that engages with the lens. 6. The light emitting device according to claim 1, wherein the LED chip is sealed in close contact with the lens. 7. The fluorescent glass is produced by doping a glass material with a fluorescent material.
The light emitting device according to any one of 1. 8. The light emitting device according to claim 7, wherein the fluorescent glass is manufactured by a sol-gel method. 9. The light emitting device according to claim 7, wherein the fluorescent material is a rare earth element. 10. An LE that emits light that excites a fluorescent material.
A step of preparing a D chip and a lead frame, mounting the LED chip on the lead frame; a step of providing a hollow portion to form a lens with fluorescent glass; a step of forming a fluorescent glass plate with fluorescent glass; A step of inserting and fixing a lead frame having the LED chip mounted on a fluorescent glass plate, and housing the LED chip and the lead frame in the hollow portion in an inert gas atmosphere to separate the lens and the fluorescent glass plate. A method of manufacturing a light emitting device, comprising the step of adhering. 11. An LE that emits light that excites a fluorescent material.
A step of preparing a D chip and a lead frame and mounting the LED chip on the lead frame; a step of providing a hollow portion and forming a lens with fluorescent glass; and a step of accommodating the LED chip and the lead frame in the hollow portion. And a step of sealing the periphery of the LED chip and the lead frame with a transparent resin or a fluorescent resin. 12. An LE that emits light that excites a fluorescent material.
A step of preparing a D chip and a lead frame, mounting the LED chip on the lead frame; and a step of closely sealing the LED chip and the lead frame with a lens formed of fluorescent glass A method for manufacturing a light emitting device, comprising: