CN101295755A - Phosphor film for light emitting diodes - Google Patents

Abstract

The invention relates to a fluorescent powder film for light emitting diodes, which is made by mixing and stirring appropriate amounts of any transparent glue or transparent plastic material with fluorescent powder in a proper proportion, and then molding the glue into a film shape.

Description

Phosphor Thin Films for Light Emitting Diodes

technical field

The invention is a fluorescent powder film, especially a fluorescent powder film used for light-emitting diodes.

Background technique

In order to make traditional high-power light-emitting diodes have different color light emitting methods, such as emitting white light, the known manufacturing process is to dispense blue light-emitting chips (InGaN) through glue containing yellow phosphor (Yellow Phosphor), so that the glue Liquid covers the chip, and the principle of light mixing is that the blue light emitted by the chip excites the yellow phosphor in the glue to emit yellow light, so that the two colors of light are mixed to form white light.

As shown in Figure 1, it is a schematic diagram of a traditional high-power light-emitting diode (LED) packaged phosphor, and its preparation process is as follows:

(1) Die-fixing step: first apply silver glue on the lead frame 10 points, then stick the blue light chip 20 on the lead frame 10, and then put it into a baking oven to bake and fix;

(2) wire bonding step: several conductive wires (gold wires) 30 are respectively welded between the P pole and the N pole of the chip 20 in the cup of the lead frame 10 and the lead frame 10, so that the lead frame 10 and the chip 20 The P and N poles are turned on;

(3) Phosphor powder glue dispensing step: first mix and stir a certain amount of phosphor powder and transparent silica gel, then use a syringe to dispense glue 40 containing phosphor powder on the chip 20 on which the conductive wire 30 has been welded, and After covering it, put it into a baking oven and bake to solidify the phosphor glue 40; and

(4) Covering the lens (Lens) step: After the lead frame 10 that has completed the above steps is covered with a lens 50, then use transparent silica gel to inject and fill up the gap between the lead frame 10 of the lens 50, and finally put the light-emitting diode into it again. Bake in a baking oven until solidified, and then a light-emitting diode emitting white light can be obtained.

In the manufacturing process of the aforementioned white light emitting diode, its obvious deficiency is that after the phosphor powder is stirred and mixed with the transparent silica gel, it is placed aside for later use. At this time, as the standing time is longer, the separation between the phosphor powder and the transparent silica gel becomes more obvious. This situation makes the content of the phosphor powder in the silica gel different every time glue is dispensed. Furthermore, after the phosphor powder is dispensed and covers the chip, the phosphor powder will precipitate during baking and curing, so that the thickness of the phosphor powder will be uneven around the chip, so that the white light emitting diodes produced in the same batch will not be uniform. Emitting white light with different color temperatures makes it difficult to control the quality consistency, which relatively increases the manufacturing cost, but cannot produce the color light with the predetermined color temperature, thus causing a bottleneck in production and manufacturing.

Contents of the invention

In view of this, the purpose of the phosphor film used in light-emitting diodes of the present invention is to improve the existing glue dispensing operation with phosphor glue, which may cause unevenness on the surface of the glue on the chip in the lead frame cup. Therefore, it can only be placed in an oscillator for vibration, so that although the surface of the glue can reach a flat state, it will also cause a serious lack of phosphor precipitation. I hope to find another way. After mixing the phosphor with the glue, And prepare it into a thin film, and then combine the thin film on the bottom of the lens. When the colored light emitted by the chip, such as blue light, excites the yellow phosphor powder on the bottom of the lens to emit yellow light, so that the two colored lights can be mixed to emit white light.

In order to achieve the above object, the technical solution of the present invention is to provide a phosphor film for light-emitting diodes, which is obtained by mixing and stirring an appropriate amount of any transparent glue or transparent plastic material and phosphor according to an appropriate ratio. , and make the glue into a thin film shape.

The phosphor film for light-emitting diodes, wherein the phosphor is mixed and stirred evenly with transparent glue or transparent plastic material, and then evenly distributed on the plane jig by coating, and then made into the required thickness, and cured to form a thin film.

The phosphor film used for light-emitting diodes, wherein the phosphor film emits colored light of a specific wavelength through the chip of the light-emitting diode to excite the phosphors in the film to produce colored light of different wavelengths, and then achieves the desired color light through light mixing. light within a specific range of wavelengths.

The phosphor film for light-emitting diodes, wherein the phosphor film is cut and shaped according to the shape of the bottom surface of the lens, and attached to the bottom surface of the lens.

The phosphor film for light-emitting diodes, wherein the phosphor film is attached to the inside of the lighting lampshade.

Enforcement of the present invention, the effect that it obtains is as follows:

(1) It can solve the problem of uneven dispensing of phosphor powder: in the past, after mixing phosphor powder and colloid, glue is directly dispensed on the chip, and the chip is covered, and then sent to the baking oven for baking , and in the process of dispensing, covering and baking, the phosphor powder is precipitated due to the length of time, and then an uneven phenomenon is formed, so that the color temperature of the desired color light emitted by each light-emitting diode is inconsistent.

(2) Wide range of applications: the phosphor film of the present invention can be used in lenses of different shapes or directly pasted inside lighting lampshades, making the range of applications wider.

(3) Accurate quality control: The color temperature of the phosphor film is graded by different phosphors and densities, so that the application side can accurately control the color light, such as the color temperature of white light, whether it is a cool white light above 6000k or a warm light of 3500k The production of white light can easily meet the control requirements.

(4) Cost saving: Once the uncured colloid is mixed, it has a certain period of use. If the amount of one deployment is too large and cannot be used within the period, it will solidify and cannot be used. Therefore, when the fluorescent film is made, it has been cured and can be stored permanently, which can save time and money on the application side.

(5) Convenient operation: the dispensing operation of traditional fluorescent powder glue is not easy to control the amount of glue, and the phenomenon of over or under often occurs, and the quantity and time of the same batch of production will cause the problem of uneven distribution of phosphor powder . In contrast, the present invention only needs to attach the phosphor film to the lens or the lighting lampshade, which is very convenient to operate.

Description of drawings

1 is a cross-sectional view of a known light-emitting diode;

Fig. 2 is the three-dimensional view of phosphor film of the present invention;

Fig. 3 is the sectional view of phosphor film of the present invention;

4a to 4c are cross-sectional views of the present invention applied to lenses of different shapes and packaged into light emitting diodes.

Detailed ways

In order to further reveal the specific technical content of the present invention, please refer to the accompanying drawings.

As shown in Figures 2 to 3, basically, the phosphor film 1 used in light-emitting diodes according to the present invention is mixed and stirred evenly with any transparent glue or transparent plastic material 11 and phosphor 12 in an appropriate proportion. , coated on the plane fixture, put it into the ultrasonic vibration arrangement mechanism and let it stand for a period of time, so that the phosphor 12 can be fully and uniformly deposited on the surface of the plane fixture, and then make the required phosphor film 1. Finally, the phosphor film 1 is sent into a baking oven for baking, and becomes the finished phosphor film 1 after curing. However, the above-mentioned film-forming method is only one of the embodiments, and it is not limited to the object to be protected by the present invention. For example, the film-forming method can also form a phosphor film 1 without vibrating or baking steps.

In fact, the phosphor film 1 of the present invention is characterized in that it excites the phosphor powder 12 in the film 1 to produce colored light of different wavelengths by emitting colored light of a specific wavelength through a light-emitting diode (LED) chip, and then through the effect of light mixing To achieve the required specific range of wavelength light, for example, the blue light chip emits blue light to excite a specific yellow phosphor to emit yellow light, and after light mixing, it emits white light.

Alternatively, RGB (red, green and blue) phosphors can also be used to make the phosphor film 1, which is excited by the UV (ultraviolet light) or Nuv (sub-ultraviolet light) emitted by the chip to emit red, green, and blue light from the phosphors in the film 1. , and through light mixing to form white light. Therefore, any phosphor powder that can be excited by light-emitting diodes can be made into a phosphor film and applied.

Please refer to Figure 4a, which is the preparation steps of applying the phosphor film 1 of the present invention to light-emitting diodes:

(1) Solid crystal step: First, put silver glue on the inside of the cup body 21 of the lead frame 2, then fix at least one blue-ray chip 3 on the bottom surface of the cup body 21, and then send the lead frame 2 into a baking oven for baking , so that each chip 3 is fixed on the bottom surface of the cup body 21 of the lead frame 2 .

(2) wire bonding step: respectively weld several conductive wires 4 between the P pole and the N pole of the chip 3 on the bottom surface of the cup body 21 of the lead frame 2 and the lead frame 2, so that the lead frame 2 and each chip 3 The P and N poles are turned on.

(3) Attaching step: cut and shape the pre-prepared yellow phosphor film 1 according to the shape of the bottom surface of the lens 5 , and then attach each phosphor film 1 to the bottom surface of each lens 5 .

(4) Covering the lens step: inject the lead frame 2 that has completed the wire welding step into transparent silica gel, and then cover the lens 5 with a yellow phosphor film 1 on the bottom surface at the opening position, and squeeze the air completely when the lens 5 is pressed in. Finally, the semi-finished light-emitting diode is sent into a baking oven to be baked until solidified, and then a light-emitting diode capable of emitting white light can be obtained.

Therefore, the present invention does not have the inconvenience of using fluorescent powder glue to cover the chip in the traditional dispensing operation, but combines the phosphor film on the bottom surface of the lens or directly attaches it to the inside of the lampshade, so that the colored light emitted by the chip 3 excites the phosphor It emits colored light of a specific color, and through light mixing, it forms light of the desired color.

As shown in FIGS. 4 a to 4 c , they are schematic diagrams of applying the phosphor film 1 of the present invention to lenses 5 of different shapes and packaging them into light emitting diodes.

Therefore, through the implementation of the present invention, the effects obtained are as follows:

(1) It can solve the problem of uneven dispensing of phosphor powder: in the past, after mixing phosphor powder and colloid, glue is directly dispensed on the chip, and the chip is covered, and then sent to the oven for baking , and in the process of dispensing, covering and baking, the phosphor powder is precipitated due to the length of time, and then an uneven phenomenon is formed, so that the color temperature of the desired color light emitted by each light-emitting diode is inconsistent.

(2) Wide range of application: As shown in Figure 4a to Figure 4c, the phosphor film of the present invention can be used in lenses of different shapes or directly pasted inside the lighting lampshade, making the application range wider.

(3) Accurate quality control: The color temperature of the phosphor film is graded by different phosphors and densities, so that the application side can accurately control the color light, such as the color temperature of white light, whether it is a cool white light above 6000k or a warm light of 3500k The production of white light can easily meet the control requirements.

(4) Cost saving: Once the uncured colloid is mixed, it has a certain period of use. If the amount of one deployment is too large and cannot be used within the period, it will solidify and cannot be used. Therefore, when the fluorescent film is made, it has been cured and can be stored permanently, which can save time and money on the application side.

(5) Convenient operation: the dispensing operation of traditional fluorescent powder glue is not easy to control the amount of glue, and the phenomenon of over or under often occurs, and the quantity and time of the same batch of production will cause the problem of uneven distribution of phosphor powder . In contrast, the present invention only needs to attach the phosphor film to the lens or the lighting lampshade, which is very convenient to operate.

The disclosure of the present invention is one of the preferred embodiments. For example, all partial changes or modifications are derived from the technical idea of the present invention and can be easily deduced by those skilled in the art, and all of them are within the scope of protection of the claims of the present invention. .

Claims (6)

1. A fluorescent powder film for light-emitting diodes, characterized in that it is made of any transparent glue or transparent plastic material and fluorescent powder according to an appropriate ratio after mixing and stirring evenly, and the glue is made film shape. 2. The phosphor film used for light-emitting diodes as claimed in claim 1, wherein the phosphor is uniformly distributed on the plane fixture by coating after mixing and stirring with transparent glue or transparent plastic material on, then made to the desired thickness, and cured to form a thin film. 3 . The phosphor film for light-emitting diodes as claimed in claim 2 , wherein the phosphor film is cured through a baking oven. 4 . 4. The phosphor film used for light-emitting diodes as claimed in claim 1, wherein the phosphor film excites the phosphors in the film to produce colored lights of different wavelengths through the chip of the light-emitting diode emitting colored light of a specific wavelength , and then through light mixing to achieve the desired wavelength of light within a specific range. 5 . The phosphor film for light-emitting diodes according to claim 1 , wherein the phosphor film is cut and shaped according to the shape of the bottom surface of the lens, and attached to the bottom surface of the lens. 6 . The phosphor film for light-emitting diodes as claimed in claim 1 , wherein the phosphor film is attached to the inside of the lighting lampshade. 7 .

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