CN104993035B - A kind of warm white LED light-emitting device - Google Patents

Abstract

The invention discloses a warm white LED lighting device, which comprises a base with electrodes and a heat sink, and an LED chip surrounded by the base and welded to the top surface of the heat sink. The gold wire is electrically connected to the electrode, and also includes a fluorescent conversion cover, which is arranged above the base and covers the LED chip, and the fluorescent conversion cover is composed of blue, green and red three primary color phosphors and It is formed by mixing and curing resin colloids; the composition of the blue, green and red phosphors is: blue phosphor: Sr ₅ (PO ₄ ) ₃ Cl:Eu ²⁺ ; green phosphor: (Ca,Sr) ₂ SiO ₄ :Eu ²⁺ ; red phosphor: CaAlSiN ₃ :Eu ²⁺ ; the excitation wavelength of the LED chip is 220nm-420nm. The warm white LED lighting device has the advantages of adjustable color temperature (2500-6000K), high color rendering index (R _a =80-96), simple process and high light extraction efficiency.

Description

A warm white LED lighting device

technical field

The invention relates to the field of lighting engineering, in particular to a lighting device, in particular to a warm white LED lighting device.

Background technique

White LED light-emitting diodes are called a new generation of solid light sources because they replace existing incandescent lamps and fluorescent lamps because of their energy saving, high efficiency, long life and environmental protection. It is widely used in night scene projects, tunnels, shopping malls, signal systems and other fields.

At present, the white light LED that realizes the commercial use of white light LED is a fluorescent conversion white light LED composed of YAG:Ce ³⁺ and a GaN tube core that emits blue light. This method prepares white light LEDs that lack the spectrum of the red light region, resulting in poor color rendering index and low luminous efficiency. Application of lamp holder. Recently, the emission wavelength of GaN chips (GaInN) is developing towards short-wave violet light (<420nm). wide, the color rendering index can be further increased, and the color temperature can be further decreased. It is very important to develop high-resolution and warm white LEDs excited by short-wave chips such as near-ultraviolet and ultraviolet light for LEDs to enter indoor lighting.

Contents of the invention

In order to solve the above-mentioned problems in the prior art, the present invention provides a high color rendering index warm white LED lighting device with high light extraction efficiency, simple process and low cost.

The technical solution provided by the present invention is as follows: a warm white LED lighting device, including a base with electrodes and a heat sink, and an LED chip surrounded by the base and welded to the top surface of the heat sink, the The LED chip is electrically connected to the electrode through a gold wire,

It also includes a fluorescent conversion cover, the fluorescent conversion cover is arranged above the base and covers the LED chip, and the fluorescent conversion cover is formed by mixing and curing blue, green and red three primary color phosphors and resin colloid;

The composition of the blue, green and red three primary color phosphors is: blue phosphor: Ca ₅ (PO ₄ ) ₃ Cl:Eu ²⁺ and/or Sr ₅ (PO ₄ ) ₃ Cl:Eu ²⁺ ; green phosphor :(Ca,Sr) ₂ SiO ₄ :Eu ²⁺ and/or Ba ₂ SiO ₄ :Eu ²⁺ ; red phosphor: CaAlSiN ₃ :Eu ²⁺ and/or Y ₂ O ₃ :Eu ³⁺ and/or Y ₂ O ₂ S:Eu ³ ;

The mixing mass ratio of the blue, green and red three primary color phosphors is: blue phosphor: green phosphor: red phosphor (1.0-4): (0.5-3): (1-4);

The excitation wavelength of the LED chip is 220nm-420nm.

In a preferred embodiment of the present invention, the mixing mass ratio of the blue, green and red three primary color phosphors is: blue phosphor: green phosphor: red phosphor (1.0-3.8): (0.5-2.5): (1.2～3.5).

In a preferred embodiment of the present invention, the mixing mass ratio of the blue, green, and red three primary color phosphors is: blue phosphor: green phosphor: red phosphor is 2:0.8:1.6.

In a preferred embodiment of the present invention, the mixing ratio of the blue, green, and red phosphor powder and the resin colloid is 0.001-1 g blue, green, and red phosphor powder per ml of resin gel.

In a preferred embodiment of the present invention, the resin colloid is set to be anti-ultraviolet aging epoxy resin or silicone resin.

In a preferred embodiment of the present invention, the blue phosphor can be set as Sr ₅ (PO ₄ ) ₃ Cl:Eu ²⁺ .

In a preferred embodiment of the present invention, the green phosphor can be set as (Ca,Sr) ₂ SiO ₄ :Eu ²⁺ .

In a preferred embodiment of the present invention, the red phosphor can be set as CaAlSiN ₃ :Eu ²⁺ .

In a preferred embodiment of the present invention, the blue, green, and red trichromatic phosphors are all synthesized by a high-temperature solid-phase method.

A method for preparing a warm white LED lighting device, comprising the following steps:

1) Fix the LED chip on the heat sink, and connect the two ends of the LED chip to the two electrodes at the bottom of the base through gold wires;

2) Use blue, green and red three primary color phosphors and resin colloid to mix evenly according to a certain powder-to-glue ratio;

3) Take out the prepared LED chip, and carry out dispensing and encapsulation;

4) Put the glued LED chips in the air to cure for a period of time, then put them into a vacuum drying oven to dry.

The advantages of the present invention are as follows: the warm white LED lighting device adopts LED chips with an excitation wavelength range of 220nm to 420nm. At the same time, the warm white LED light-emitting device is provided with a fluorescent conversion cover above the LED chip, and a high-purity blue, green and red three-color phosphor is set on the fluorescent conversion cover, so that the LED chip can excite the blue, green and red three-primary color phosphor Finally, warm white light with high color rendering index can be obtained. The warm white light thus obtained can realize controllable color temperature (2500-6000K) and color rendering index (80-96). The resulting color rendering index is 85, so the warm white LED lighting device has the advantages of high color rendering index, simple process, and high light extraction efficiency.

Description of drawings

Fig. 1 is the structural representation of the warm white LED lighting device of the present invention;

Fig. 2 is the spectrogram (CCT is the color temperature, and Ra is the color rendering index) of the warm white LED lighting device of the present invention prepared with a 395nm chip;

Detailed ways

Referring to FIG. 1, a warm white LED lighting device includes a base 20 with two electrodes 40 and a heat sink 30, and an LED chip 10 surrounded by the base 20 and soldered to the top surface of the heat sink 30. The two electrodes 40 respectively at both ends of the base 20, used to lead out the positive and negative poles of the LED chip 10, the LED chip 10 is electrically connected to the electrode 40 through the gold wire 50, the fluorescent conversion cover 60 is arranged above the base 20 and covers the LED The chip 10 and the fluorescent conversion cover 60 are formed by mixing and curing blue, green and red three primary color phosphors and resin colloid.

Wherein the LED chip 10 may be an ultraviolet, near ultraviolet or ultraviolet chip, and its excitation wavelength range covers 220nm-420nm.

The blue phosphor can be set as Ca ₅ (PO ₄ ) ₃ Cl:Eu ²⁺ and/or Sr ₅ (PO ₄ ) ₃ Cl:Eu ²⁺ ;

The green phosphor can be set as (Ca,Sr) ₂ SiO ₄ :Eu ²⁺ and/or Ba ₂ SiO ₄ :Eu ²⁺ ;

The red phosphor can be set as CaAlSiN ₃ :Eu ²⁺ and/or Y ₂ O ₃ :Eu ³⁺ and/or Y ₂ O ₂ S:Eu ³ .

In this embodiment, blue, green and red three primary color phosphors are respectively Sr ₅ (PO ₄ ) ₃ Cl:Eu ²⁺ , (Ca,Sr) ₂ SiO ₄ :Eu ²⁺ , CaAlSiN ₃ :Eu ²⁺ , And synthesized by high-temperature solid-phase method.

First, the LED chip 10 is fixed on the heat sink 30, and the two ends of the LED chip 10 are connected to the two electrodes 40 at the bottom of the base through the gold wire 50 respectively, and then the fluorescent conversion cover 60 is prepared, and the blue, green and red three kinds of The phosphor powder was fully ground and mixed with an agate crucible according to the weight ratio of 2:0.8:1.6, 0.13g was taken out and mixed with 1ml of epoxy resin and mixed evenly, and the prepared LED chip 10 was taken out for dispensing and encapsulation. Then put it in the air to solidify for 5 minutes, put it in a vacuum drying oven to dry and vacuumize at 50°C for 5 hours. The spectra and pictures of the obtained warm white LEDs are shown in Figure 2. In this example, a 395nm chip is used, driven by a voltage of 3.29V and a current of 300mA, a warm white LED with a color temperature of 3568K, a color rendering index of 94.65, and a color coordinate of (0.3952, 0.3709) can be obtained.

To sum up, the warm white LED light-emitting device adopts the LED chip 10 with an excitation wavelength range of 220nm-420nm, and at the same time, a fluorescent conversion cover 60 is arranged on the top of the LED chip 10, and a blue color with high color purity is arranged on the fluorescent conversion cover 60. The green and red three-primary-color phosphors enable the LED chip 10 to obtain warm white light with a high color rendering index after exciting the blue-green-red three-primary-color phosphors. ~96) is controllable, and its color rendering index far exceeds the color rendering index 85 produced by other blue light chips with phosphor powder. Therefore, the warm white LED lighting device has the advantages of high color rendering index, simple process, and high light extraction efficiency.

The above is only a specific embodiment of the present invention, but the design concept of the present invention is not limited thereto, any insubstantial changes to the present invention by using this concept should be an act of violating the protection scope of the present invention.

Claims (8)

1. a kind of warm white LED light-emitting device, include with electrode and heat sink pedestal, and by the pedestal be enclosed in simultaneously It is welded in the LED chip of the heat sink top surface, the LED chip is electrically connected by gold thread with the electrode, it is characterised in that：

Further include fluorescence conversion cover, fluorescence conversion, which is provide with, to be set in the top of the pedestal and be provide with residence and state LED chip, institute Fluorescence conversion cover is stated by bluish-green red three primary colors fluorescent powder and resin colloid is mixing cured forms；

The constituent of the bluish-green red three primary colors fluorescent powder is：Blue colour fluorescent powder：Ca₅(PO₄)₃Cl:Eu²⁺And/or Sr₅(PO₄)₃Cl:Eu²⁺；Green emitting phosphor:(Ca,Sr)₂SiO₄:Eu²⁺And/or Ba₂SiO₄:Eu²⁺；Red fluorescence powder：CaAlSiN₃:Eu²⁺With/ Or Y₂O₃:Eu³⁺And/or Y₂O₂S:Eu³⁺；

The mixing quality ratio of the bluish-green red three primary colors fluorescent powder is：Blue colour fluorescent powder：Green emitting phosphor：Red fluorescence powder is (1.0~4)：(0.5~3)：(1~4)；

The LED chip excitation wavelength is 220nm~420nm.

2. warm white LED light-emitting device according to claim 1, it is characterised in that：The bluish-green red three primary colors fluorescent powder Mixing quality ratio be：Blue colour fluorescent powder：Green emitting phosphor：Red fluorescence powder is (1.0~3.8)：(0.5~2.5)：(1.2~ 3.5)。

3. warm white LED light-emitting device according to claim 2, it is characterised in that：The bluish-green red three primary colors fluorescent powder Mixing quality ratio be：Blue colour fluorescent powder：Green emitting phosphor：Red fluorescence powder is 2：0.8：1.6.

4. a kind of warm white LED light-emitting device according to claim 1, it is characterised in that：The bluish-green red three primary colours are glimmering Its mixed proportion is to match the bluish-green red three primary colors fluorescent powders of 0.001~1g per ml resin colloids to light powder with resin colloid.

5. a kind of warm white LED light-emitting device according to claim 1, it is characterised in that：The blue colour fluorescent powder setting For (Sr, Ca)₅(PO₄)₃Cl:Eu²⁺。

6. a kind of warm white LED light-emitting device according to claim 1, it is characterised in that：The green emitting phosphor setting For (Ca, Sr₎₂Si_O4:E^u2+。

7. a kind of warm white LED light-emitting device according to claim 1, it is characterised in that：The red fluorescence powder setting For CaAlSiN₃:Eu²⁺。

8. a kind of preparation method of warm white LED light-emitting device according to claim 1, feature include the following steps：

1) LED chip is fixed on heat sink, and LED chip both ends is led by two electrodes of gold thread and base bottom respectively It is logical；

2) it is uniformly mixed by certain Ratio of filler bitumen with resin colloid with bluish-green red three primary colors fluorescent powder；

3) LED chip prepared is taken out, glue dispensing and packaging is carried out；

4) after the good LED chip of dispensing being placed on air set for a period of time, it is put into vacuum drying chamber drying.