TW201403875A - White light LED - Google Patents

Abstract

The present invention relates to white light LED includes: a light emitting device with a substrate and one or a plurality of LED chips disposed on the substrate, a plurality of adhesive layers disposed on the LED chips, a fluorescent layer interposed in the adhesive layers, and an encapsulated resin layer that is encapsulated on the light emitting device.

Description

White light emitting diode

The invention relates to a white light emitting diode, in particular to a white light emitting diode capable of real-time adjusting the phosphor powder content to achieve a target color temperature in a process by using a multi-layer stacking technique.

Since the 1960s, the advantages of low power consumption and long-lasting illumination of Light Emitting Diodes (LEDs) have gradually replaced the use of indicators or light sources for lighting or various electrical appliances in daily life. . What's more, the development of multi-color and high-brightness LEDs has been applied to large outdoor display billboards or traffic signs, indicating that they can be applied in a wide range of fields.

In recent years, due to the significant increase in the luminous efficiency of light-emitting diodes, white light-emitting diodes have replaced the trend of traditional white-light bulbs. Conventional white-light emitting diodes are usually produced by spraying or coating fluorescent powder. And the like is disposed on the LED body, and then encapsulating the wafer with the encapsulating resin, so that the phosphor powder can be excited by the light emitted by the wafer to emit light of a suitable wavelength, and then mixed into white light. The light-emitting diode manufactured by the fluorescent powder is directly exposed to the wafer, is easily heated to accelerate the deterioration of the fluorescent powder, and shortens the life of the product; and the other method is to mix the fluorescent powder in the encapsulating resin. Directly using such a phosphor-containing encapsulating resin to encapsulate a light-emitting diode wafer, the light-emitting diode produced in this manner seems to prevent the phosphor powder from directly contacting the diode wafer. Accelerate its degradation, but there is an inevitable increase in the amount of phosphor powder used, resulting in unnecessary waste. In addition, the above two conventional methods of fabricating white light emitting diodes inevitably require curing of the encapsulating resin to know whether the color temperature of the product reaches its target. If the batch does not reach its target color temperature, only It can be recycled in batches, which is a big obstacle to the improvement of product yield.

Therefore, in order to improve the quality of the product of the light-emitting diode, to avoid the accelerated deterioration of the phosphor powder due to heat, the life of the product is shortened, thereby improving the yield of the product, reducing the waste of unnecessary raw materials, and developing a new way of manufacturing the light-emitting diode. It is necessary.

The main object of the present invention is to provide a white light emitting diode which can prevent the phosphor powder from directly contacting the light emitting diode wafer, thereby causing the fluorescent powder to be heated and accelerated to deteriorate, thereby shortening the life of the product; The required amount of phosphor powder is to prevent the color temperature analysis of the finished product from failing to reach the target color temperature to form a defective product, thereby reducing waste of unnecessary raw materials and improving product yield.

In order to achieve the above object, an aspect of the present invention provides a white light emitting diode comprising: a light emitting unit having a substrate and one or more light emitting diode chips disposed on the surface of the substrate; An adhesive layer on the surface of the light-emitting diode; a phosphor layer disposed between the adhesive layers; and an encapsulating resin layer covering the surface of the light-emitting unit.

In the white light emitting diode of the present invention, the adhesive layer may have a multi-layer structure, such as a three-layer structure, including a first adhesive layer covering the surface of the light-emitting diode wafer; a second adhesive layer on the surface of the first adhesive layer; and a third adhesive layer covering the surface of the second adhesive layer, wherein the first adhesive layer has a higher refractive index than the second adhesive layer, and the second adhesive layer The refractive index of the layer can be higher than the third adhesive layer.

In the white light emitting diode of the present invention, the phosphor layer may be a single layer or a multilayer structure and sandwiched between the adhesive layers. The phosphor layer may have a two-layer structure, including a first phosphor layer disposed between the first adhesive layer and the second adhesive layer, and a first layer of the adhesive layer. a second phosphor layer between the second adhesive layer and the third adhesive layer, and the phosphor layers may be distributed on the adhesive layers in a continuous or discontinuous pattern. The phosphor powder may comprise a red fluorescent powder, a green fluorescent powder, a blue fluorescent powder, a yellow fluorescent powder or a combination thereof, wherein the red fluorescent powder may be selected from Ca ₂ SiN ₈ :Eu ²⁺ , Sr ₂ SiN ₈ :Eu ²⁺ , CaAlSiN ₃ :Eu ²⁺ , CaS:Eu ²⁺ , Y ₂ O ₃ :Eu ³⁺ , Y ₂ O ₃ :Bi ³⁺ ,(Y,Gd) ₂ O ₃ :Eu ³⁺ , (Y,Gd) ₂ O ₃ :Bi ³⁺ , Y ₂ O ₂ S:Bi ³⁺ , (Me _1-x Eu _x )ReS, Mg ₂ TiO ₄ :Mn ⁴⁺ , And a group consisting of Mg ₃ SiO ₄ : Mn; the green phosphor can be selected from (Ba, Sr)SiO ₄ :Eu ²⁺ , Lu ₃ Al ₅ O ₁₂ :Ce ³⁺ , YBO ₃ :Ce ^{3 +} , YBO ₃ : TB ³⁺ , SrGa ₂ S ₄ :Eu ²⁺ , SrGa ₂ O ₄ :Eu ²⁺ , SrSi ₂ N ₂ O ₂ :Eu ²⁺ , SrAl ₂ O ₄ :Eu ²⁺ , (Ba, Sr) MgAl ₁₀ O ₁₇ :Eu ²⁺ and (Ba,Sr)MgAl ₁₀ O ₁₇ :Mn ²⁺ group; the blue phosphor powder can be selected from BaMgAl ₁₀ O ₁₇ :Eu ²⁺ and (Ca, a group of Sr,Ba) ₅ (PO ₄ ) ₃ Cl:Eu ²⁺ , Gd ²⁺ ; and the yellow fluorescent powder may be Y ₃ Al ₅ O ₁₂ :Ce ³⁺ , Tb ₃ Al ₅ O ₁₂ : Ce ³⁺ , CaSi ₂ N ₂ O ₂ :Eu ²⁺ , (Y,Cd) ₃ Al ₅ O ₁₂ :Ce ³⁺ , or (Me _{1 - xy} Eu _x Re _y ) ₃ SiO ₅ , the above Me may be selected from the group consisting of Ca, Sr, Ba and combinations thereof; Re may be selected from the group consisting of Pr, Sm, Rb, Dy, Ho, Y, Er, Eu, Tm, Yb, Cr, Sr, Lu, Gd, Al, Zn, and combinations thereof.

In the white light emitting diode of the present invention, the adhesive layer and the encapsulating resin layer may be composed of a thermosetting resin or a photocurable resin containing an epoxy resin, a silicone resin, an acrylic resin or a combination thereof.

In the above white light emitting diode of the present invention, the light emitting unit may be composed of one or a plurality of light emitting diode chips having different wavelengths of light, preferably 2 to 16 light emitting diodes having different wavelengths of light. The body wafer is composed of.

In the above-described white light emitting diode of the present invention, the adhesive layer and the phosphor powder layers may be formed in various manners known in the art, such as spraying or coating, but the invention is not limited thereto.

In addition, another object of the present invention is to provide a chip on board (COB) in which the above-described light emitting diode package structure of the present invention is applied to the wafer board, thereby encapsulating the wafer board. The structure can instantly adjust the required phosphor powder content, so as to prevent the product from forming a defective product when the color temperature analysis of the package is not reached, thereby reducing the waste of unnecessary raw materials and thereby improving the product yield.

In order to achieve the above object, another aspect of the present invention provides a chip on board (COB) including: a substrate which can be a circuit carrier; and the above-described white light emitting diode of the present invention. The circuit carrier is packaged via a metal solder layer that can be gold or gold tin.

In the above wafer-on-package structure of the present invention, the circuit carrier includes an insulating layer and a circuit substrate, wherein the insulating layer is made of insulating diamond-like carbon, aluminum oxide, ceramic, and diamond-containing epoxy. The resin, or a composition thereof, or a metal material having a surface covered with the insulating layer, and the circuit substrate may be a metal plate, a ceramic plate or a substrate. In addition, the surface of the circuit carrier can also optionally include a type of drilled carbon layer to increase the heat dissipation effect.

The embodiments of the present invention are described by way of specific examples, and those skilled in the art can readily appreciate the other advantages and advantages of the present invention. The present invention may be embodied or applied in various other specific embodiments, and various modifications and changes can be made without departing from the spirit and scope of the invention.

The drawings in the embodiments of the present invention are simplified schematic diagrams. However, the illustrations only show the components related to the present invention, and the components shown therein are not in actual implementation, and the actual number of components in the actual implementation is a selective design, and the component layout type. The state may be more complicated.

1A to 1G are schematic diagrams showing the flow structure of a method for fabricating a white light emitting diode according to a first embodiment of the present invention. In this embodiment, a three-layer adhesive layer and two layers of fluorescent light are laminated on a light-emitting diode wafer. White light emitting diode of powder layer.

Referring to FIG. 1A, first, a light emitting unit 10 is prepared, which includes a substrate 4 and a light emitting diode chip 3 disposed on the substrate 4. Then, a first adhesive layer 11 is disposed on the upper surface 3a of the LED body, such as 1B; after drying, a red phosphor is disposed on the upper surface 11a of the first adhesive layer to form a continuous distribution of the first phosphor layer 21, as shown in FIG. 1C; the first phosphor layer 21 is to be After drying, a second adhesive layer 12 is disposed on the first phosphor layer 21 and dried, as shown in FIG. 1D; at this time, the semi-finished product of the white light emitting diode can be analyzed for color temperature, if not required. The target color temperature is further provided with a yellow phosphor powder on the upper surface 12a of the second adhesive layer to form a continuous distribution of the second phosphor layer 22, as shown in FIG. 1E; after drying, the second phosphor layer 22 is further dried. A third adhesive layer 13 is disposed and dried, as shown in FIG. 1F; at this time, the semi-finished product of the white light emitting diode can be further analyzed for color temperature, and if the desired target color temperature is reached, an encapsulating resin layer 5 is further disposed on the semi-finished product. To complete a white light emitting diode 100, as shown in FIG. 1G.

In the white light emitting diode of the present invention, the adhesive layer covering the surface of the LED substrate 3 (for example, the first adhesive layer 11, the second adhesive layer 12, and the third adhesive layer 13) can be arbitrarily adjusted as needed. The number of layers of the adhesive layer, the hardening method (photocurable resin or thermosetting resin), and the refractive index. Further, the phosphor layer (for example, the first phosphor layer 21 and the second phosphor layer 22) may be optionally used. Adjusting the number of layers or components of the phosphor layer, and also setting the phosphors of different light colors to different phosphor layers, or mixing the phosphors of different light colors and setting them on the same phosphor layer. Further, the phosphor layer may be distributed in a continuous or discontinuous manner between different resin layers, and the present invention is not limited thereto.

2A to 2G are schematic structural diagrams of a method for fabricating a white light emitting diode according to a second embodiment of the present invention. In this embodiment, another layer of an adhesive layer and a second layer of firefly are stacked on a light emitting diode chip. The white light emitting diode of the toner layer has the same packaging flow and method as the first embodiment except that the first phosphor powder layer 21' and the second phosphor powder layer 22' are discontinuous pattern distribution.

Referring to FIG. 2A, a light-emitting unit 10 is prepared, which includes a substrate 4 and a light-emitting diode chip 3 disposed on the substrate 4; then a first adhesive layer 11 is disposed on the upper surface 3a of the light-emitting diode wafer, such as 2B; after drying, a yellow phosphor is disposed on the upper surface 11a of the first adhesive layer to form a discontinuously distributed first phosphor layer 21', as shown in FIG. 2C; the first phosphor layer 21 is to be After drying, a second adhesive layer 12 is disposed on the first phosphor layer 21' and dried, as shown in FIG. 2D; at this time, the semi-finished product of the white light-emitting diode can be analyzed for color temperature. The target color temperature is required to further provide a yellow phosphor powder on the second adhesive layer upper surface 12a to form a discontinuously distributed second phosphor layer 22', as shown in FIG. 2E; after drying, the second phosphor is further A third adhesive layer 13 is disposed on the powder layer 22' and dried, as shown in FIG. 2F; at this time, the semi-finished product of the white light emitting diode can be further analyzed for color temperature, and if the desired target color temperature is reached, the semi-finished product is set again. A resin layer 5 is encapsulated to complete a white light emitting diode 200, as shown in FIG. 2G.

The technical feature of the present invention is to provide a technology for instantly adjusting the amount of phosphor powder required in a white light emitting diode, and to prevent the prepared white light emitting diode from being unable to reach due to excessive or insufficient phosphor powder content. The problem of forming a defective product by the target color temperature is generated, so the white light of the foregoing embodiment The light-emitting diode can repeat the process of setting the phosphor layer and the adhesive layer until the product reaches the target color temperature, as in the third embodiment, a layer of adhesive layer is laminated on the LED chip. White light emitting diode with three layers of phosphor powder.

First, please refer to FIG. 3, which is a schematic diagram of a white light emitting diode according to a third embodiment of the present invention, and refer to the flow of the first embodiment, wherein after completing the semi-finished product of the white light emitting diode of FIG. 1F, If the color temperature analysis does not reach the target color temperature, a blue phosphor powder may be further disposed on the upper surface 13a of the third adhesive layer, and after drying to form a continuously distributed third phosphor layer 23, the third firefly is further The fourth adhesive layer 14 is disposed on the light powder layer 23 and dried. After drying, color temperature analysis is performed to confirm whether the semi-finished product of the white light emitting diode reaches the target color temperature; as described above, if the target color temperature has been reached, An encapsulating resin layer 5 is disposed on the semi-finished product to complete a white light emitting diode 300. If the target color temperature is not reached, the above packaging process is repeated until the target color temperature is reached, and then the encapsulating resin layer 5 is disposed to complete the product.

Please refer to FIG. 4 , which is a schematic diagram of a white light emitting diode according to a fourth embodiment of the present invention, and refer to the flow of the second embodiment, wherein the color temperature is performed after the semi-finished product of the white light emitting diode of FIG. 2F is completed. If the target color temperature is not reached, a green phosphor may be further disposed on the upper surface 13a of the third adhesive layer, and after drying to form a discontinuously distributed third phosphor layer 23', The fourth adhesive layer 14 is disposed on the phosphor layer 23' and dried. After drying, color temperature analysis is performed to confirm whether the semi-finished product of the white light emitting diode reaches the target color temperature; as described above, if the target color temperature has been reached, An encapsulating resin layer 5 is disposed on the semi-finished product to complete a white light emitting diode 400. If the target color temperature is not reached, the above packaging process is repeated until the product reaches the target color temperature, and then the encapsulating resin layer 5 is disposed to complete the product.

5 is a schematic structural diagram of a package structure on a wafer board according to a first embodiment of the present invention; wherein, as shown in FIG. 5, the package structure on the wafer board includes: a circuit carrier board 7; and the first embodiment described above The white light emitting diode 100 is electrically connected to the circuit carrier 7 via a metal solder layer 6. The circuit carrier 7 includes an insulating layer 71 and a circuit substrate 72. The insulating layer 71 The material may be selected from diamond-like carbon, alumina, ceramic, diamond-containing epoxy resin, or a mixture of the above materials. The circuit substrate 72 is a metal plate, a ceramic plate or a substrate.

According to the present invention, in the chip on board (COB) of the present invention, the above-mentioned light emitting diode package structure of the present invention is disposed on the wafer board, so that the package structure on the wafer board can be instantly adjusted. The required amount of phosphor powder is good for improving product yield. In addition, the light-emitting diodes suitable for use in the above-described wafer-on-package structure of the present invention are not limited to the white light-emitting diodes produced in the above first embodiment, and any white light-emitting diodes according to the present invention may be used. body.

It can be seen from the above that the white light emitting diode of the present invention has a structural design capable of instantly adjusting the content of the fluorescent powder in the encapsulating resin, and can instantly adjust the phosphor powder content according to the color temperature analysis result in the process of encapsulating the light emitting diode, thereby avoiding The color temperature analysis of the product after the completion of the package does not reach the target color temperature to form a defective product, and the fluorescent powder can be concentrated on the wafer to enhance the luminous efficiency, thereby reducing waste of unnecessary raw materials and improving product yield. again Layered phosphor powder can help to extend product life by different attenuation rates of phosphor layers.

The above embodiments are merely exemplified for convenience of description. The phosphor layers may be alternately used for continuous distribution and discontinuous distribution, such as the first phosphor layer being continuously distributed and the second phosphor layer being discontinuous. The present invention is not limited thereto, and the scope of the claims should be construed as being limited to the above embodiments.

100,200,300,400‧‧‧White light emitting diode

10‧‧‧Lighting unit

11‧‧‧First adhesive layer

12‧‧‧Second Adhesive Layer

13‧‧‧ third adhesive layer

14‧‧‧Four adhesive layer

11a‧‧‧Top surface of the first adhesive layer

12a‧‧‧Second adhesive upper surface

13a‧‧‧The upper surface of the third adhesive layer

21, 21’ ‧ ‧ first fluorescent layer

22,22’‧‧‧second luminescent layer

23,23’‧‧‧ Third luminescent layer

3‧‧‧Lighting diode chip

3a‧‧‧Lighting diode wafer upper surface

4‧‧‧Substrate

5‧‧‧Encapsulated resin layer

6‧‧‧Metal welding layer

7‧‧‧Circuit carrier board

71‧‧‧Insulation

72‧‧‧ circuit board

1A to 1G are schematic structural diagrams showing a method of fabricating a white light emitting diode according to a first embodiment of the present invention.

2A to 2G are schematic structural diagrams showing a method of fabricating a white light emitting diode according to a second embodiment of the present invention.

3 is a schematic view of a white light emitting diode according to a third embodiment of the present invention.

4 is a schematic view of a white light emitting diode according to a fourth embodiment of the present invention.

Fig. 5 is a perspective view showing the package structure on the wafer board of the first embodiment of the present invention.

100‧‧‧White light emitting diode

6‧‧‧Metal welding layer

7‧‧‧Circuit carrier board

71‧‧‧Insulation

72‧‧‧ circuit board

Claims (19)

A white light emitting diode comprising: a light emitting unit having a substrate and one or a plurality of light emitting diode chips disposed on the surface of the substrate; a plurality of adhesive layers covering the surface of the light emitting diode chip a phosphor layer disposed between the adhesive layers; and an encapsulating resin layer covering the surface of the light emitting unit. The white light emitting diode according to claim 1, wherein the adhesive layers have a three-layer structure. The white light emitting diode according to claim 2, wherein the adhesive layer comprises a first adhesive layer covering the surface of the light emitting diode chip; and a second adhesive layer Covering the surface of the first adhesive layer; a third adhesive layer covering the surface of the second adhesive layer. The white light emitting diode according to claim 3, wherein the first adhesive layer has a higher refractive index than the second adhesive layer, and the second adhesive layer has a higher refractive index than the third adhesive layer. The white light emitting diode according to claim 1, wherein the phosphor layer has a single layer or a multi-layer structure and is sandwiched between the adhesive layers. The white light emitting diode according to claim 5, wherein the phosphor layer is a two-layer structure. The white light emitting diode according to claim 6, wherein the phosphor layer comprises a first phosphor layer and a second phosphor layer. The white light emitting diode of claim 7, wherein the first phosphor layer is disposed between the first adhesive layer and the second adhesive layer. The white light emitting diode according to claim 7, wherein the second phosphor layer is disposed between the second adhesive layer and the third adhesive layer. The white light emitting diode according to claim 1, wherein the adhesive layer and the encapsulating resin layer are a thermosetting resin or a photocurable resin. The white light emitting diode according to claim 10, wherein the adhesive layer and the encapsulating resin layer are epoxy resin, silicone rubber or acrylic resin. The white light emitting diode according to claim 11, wherein the adhesive layer is silicone. The white light emitting diode according to claim 1, wherein the light emitting unit is composed of two to six light emitting diode chips having different wavelengths of light. The white light emitting diode according to claim 1, wherein the fluorescent powder layer is selected from the group consisting of a red fluorescent powder, a green fluorescent powder, a blue fluorescent powder, a yellow fluorescent powder or A group of its combination. The white light emitting diode according to claim 1, wherein the phosphor layer is a continuous distribution or a discontinuous distribution. A chip on board (COB) comprising: And a white light emitting diode according to any one of claims 1 to 15, which is packaged on the circuit carrier via a metal solder layer. The wafer-on-board package structure of claim 16, wherein the circuit carrier comprises an insulating layer and a circuit substrate, and the insulating layer is made of at least one material selected from the group consisting of diamond-like carbon, aluminum oxide, ceramics, and A group of diamond-containing epoxy resins. The package structure on a wafer board according to claim 16, wherein the circuit substrate is a metal plate, a ceramic plate or a substrate. The wafer-on-package structure of claim 16, wherein the metal solder layer is gold or gold tin.