TWI499094B - Led package and method for fabricating the same - Google Patents

Description

LED package and its manufacturing method

The present invention relates to an LED package and a method of fabricating the same, and more particularly to a method of forming a uniform phosphor layer between an encapsulant and a light transmissive member and the resulting LED package.

Phosphor materials have been widely used in LED packages that produce white light or in various light colors with blue pump LEDs (eg, green or red for phosphor conversion). Conventional methods of depositing a phosphor material over a blue LED wafer or package assembly include: a slurry method: the phosphor powder is dispersed in a resin, epoxy or solvent fill material to form a phosphor mixture, which The phosphor mixture is applied to the LED surface by various techniques such as spraying or dip coating or dispensing or phosphor powder in the cup or molding on a support structure.

A problem with the above conventional methods is the difference in thickness uniformity on the LED surface or inside the LED package. The slurry method generally forms a layer of particles having varying thicknesses, resulting in inconsistent color points of the LEDs and poor color uniformity of the phosphor converted LEDs. Moreover, these conventional methods are difficult to form a uniform phosphor layer on a non-flat surface. On the other hand, enamel resin coated phosphor powder At the end, the heat generated by the phosphor powder is not transmitted to the outside, which not only increases the temperature of the LED, but also causes the phosphor powder to deteriorate and affect the optical properties. Therefore, meeting these requirements in lighting applications with these traditional methods faces considerable challenges.

Recently, LEDs produced by non-polar technology have been greatly improved in brightness under the same area conditions, which puts more demands on the heat dissipation method of LED or phosphor powder. Otherwise, the temperature of the LED The problem of rising and deterioration of phosphor powder will become more serious.

Traditional methods still have problems such as wasted phosphors, inconsistent color points of LEDs, poor color uniformity of phosphor-converted LEDs, and poor heat dissipation. Therefore, how to provide a method for manufacturing an LED package and the obtained LED package is an important issue.

In view of the above, the present invention provides a method for fabricating an LED package, comprising: providing a carrier having at least one LED die on a surface; and placing a pair of light-transmitting members having a uniform phosphor layer on a surface thereof on the LED die The uniform phosphor layer is formed on at least a portion of the light transmissive member located above the LED die, and the heat conducting layer is formed on the carrier or the light transmissive member; and the carrier and the light transmissive member An encapsulant covering the LED die and fixing the transmissive member is formed between the members, wherein the thermally conductive layer is in contact with the uniform phosphor layer.

The present invention provides an LED package, comprising: a carrier; at least one LED die disposed on the carrier; an encapsulant formed on the carrier and covering the LED die; at least part of the surface a light transmissive member having a uniform phosphor layer formed on the encapsulant and the uniform phosphor layer The pair is located above the LED die; and the thermally conductive layer is between the carrier and the light transmissive member, and the thermally conductive layer is in contact with the uniform phosphor layer.

The uniform fluorescent layer of the present invention forms a fluorescent particle or a phosphor powder and a bonding material on the surface of the light transmitting member by electrostatic adsorption, so that the obtained fluorescent layer is very uniform and provides excellent optical properties. In addition, when the fluorescent particles or the phosphor powder converts the wavelength of light emitted by the LED dies, heat is generated, and at the same time, the encapsulant is also heated, so that the fluorescent particles or the phosphor powder of the present invention are not included. The heat is applied to the encapsulant and the heat conductive layer having a better heat dissipation property is in contact with the uniform phosphor layer, so that heat can be dissipated to the outside.

10‧‧‧LED dies

12‧‧‧ Carrying parts

121‧‧‧Substrate

120‧‧‧ spacers

1200‧‧‧ recess

1201‧‧‧channel structure

1202‧‧‧Connecting Department

13‧‧‧Conducting layer

131‧‧‧Opening the window

14‧‧‧ Even fluorescent layer

15‧‧‧Adhesive layer

16‧‧‧Light transmission parts

18‧‧‧Package colloid

20‧‧‧ Thermal column

1A to 1C are schematic views showing a method of manufacturing an LED package according to a first embodiment of the present invention, wherein FIG. 1A' is a plan view of FIG. 1A; and FIGS. 2A and 2B are views showing a second embodiment of the LED package of the present invention. The method of the present invention, wherein the second embodiment shows a package colloid covering the LED die and fixing the light transmissive member between the carrier member and the light transmissive member; FIGS. 3A and 3B are diagrams of the third embodiment of the present invention. 4A to 4C are diagrams illustrating an LED package having a heat dissipation column of the present invention; FIGS. 5A and 5B are views showing the heat conduction layer previously formed on a spacer; and FIGS. 6A and 6B The carrier is a lead frame, and the heat conducting layer is formed on the surface of the lead frame.

The embodiments of the present invention are described by way of specific examples, and those skilled in the art can understand the advantages and advantages of the present invention as disclosed in the present disclosure. The present invention may be embodied or applied in various other specific embodiments. The details of the present invention can be variously modified and changed without departing from the spirit and scope of the invention.

It is to be understood that the structure, the proportions, the size, and the like of the present invention are intended to be used in conjunction with the disclosure of the specification, and are not intended to limit the invention. The conditions are limited, so it is not technically meaningful. Any modification of the structure, change of the proportional relationship or adjustment of the size should remain in this book without affecting the effects and the objectives that can be achieved by the present invention. The technical content disclosed in the invention can be covered. In the meantime, the terms "upper", "one", "top", "bottom" and "at least one" are used in this specification for convenience of description and are not intended to limit the invention. Changes in the scope of implementation, changes or adjustments in their relative relationship, are considered to be within the scope of the present invention.

Fluorescent systems are used to convert or change the wavelength of light, for example, to convert or change the source of the LED. Phosphors generally used for this purpose include yttrium aluminum garnet (YAG) materials, yttrium aluminum garnet (TAG) materials, ZnSeS+ materials, and lanthanum aluminum oxynitride (SiAlON) materials (such as α-SiALON) and the like. However, according to embodiments of the present invention, any material that converts or changes the wavelength of incident light can be used as the phosphor material. The term "phosphor" as used herein means All materials that have the ability to convert or change the wavelength of light to another wavelength, including mixtures or combinations of materials of different wavelength conversion or wavelength change. In still another embodiment, the fluorescent system is in the form of a powder and may also be referred to as a phosphor powder. The phosphor powder is composed of a plurality of fluorescent particles.

First embodiment

Please refer to FIGS. 1A to 1C for the manufacturing method of the LED package of the present invention.

As shown in Figures 1A and 1A', a carrier 12 having at least one LED die 10 on its surface is provided. Generally, a plurality of LED dies 10 can be disposed on the carrier 12 to improve manufacturing efficiency, and the carrier 12 can be cut to obtain different LED packages according to different product requirements.

The carrier 12 disclosed in the embodiment of the present invention may be an integrally formed person, or the carrier 12 includes a substrate 121 and a spacer 120 disposed on the substrate 121. The spacer 120 is surrounded by the spacer 120. The pocket 1200 is connected to the surface of the carrier 12 and correspondingly houses the LED die 10 . In addition, the inner wall surface of the spacer 120 or the recess 1200 may be formed with a reflective layer (not shown) to concentrate light and prevent light from leaking.

Further, the spacer 120 is formed by stacking metal or a plurality of nano carbon particles. When the spacer 120 is a metal, the spacer 120 can be formed by a plating process. When the spacer 120 is formed by stacking a plurality of nano carbon particles, it can be formed by a pressing method, a deposition method, or an electrostatic adsorption method.

In addition, in the preferred embodiment of the present invention, the surface of the carrier 12 is formed with a channel structure 1201 for injecting the encapsulant into the cavity 1200 when the encapsulant is subsequently formed, or when molding the encapsulant. The excess encapsulant is allowed to flow out through the channel structure 1201.

In this embodiment, the heat conductive layer 13 is formed on the light transmissive member 16. Preferably, the thermally conductive layer 13 of the present invention is a transparent carbonaceous layer comprising a plurality of nanocarbon particles.

As shown in FIG. 1B, a light-transmitting member 16 having a heat-conducting layer 13 and a uniform phosphor layer 14 formed on a surface thereof is disposed on the LED die 10 such that the LED die 10 is located on the carrier member 12 and transparent. Between the light members 16, wherein the uniform phosphor layer 14 is conveniently positioned above the LED die 10, the uniform phosphor layer 14 is formed over the entire surface. In this embodiment, the heat conducting layer 13 is formed on the entire surface of the light transmissive member 16, and the uniform phosphor layer 14 is formed on the heat conducting layer 13 so that the heat conducting layer 13 is sandwiched by the uniform fluorescent layer. Between the layer 14 and the light transmissive member 16.

The heat conducting layer includes a plurality of nano carbon particles, and examples of the nano carbon particles include at least one of a group consisting of fullerenes and graphenes. In a specific embodiment, the fullerene is a carbon nanotube.

For example, a method of forming the heat conductive layer includes stacking a plurality of nano carbon particles on the light transmissive member by press bonding directly to the surface of the light transmissive member. Alternatively, as shown in FIG. 1B, the surface of the light transmissive member 16 has a cement layer 15; then, a plurality of nano carbon particles such as carbon nanotubes may be stacked on the cement layer by a deposition method or an electrostatic adsorption method. 15 is formed to form the heat conductive layer 13.

Further, the formation of the uniform phosphor layer 14 is formed by electrostatic adsorption. The aforementioned electrostatic adsorption system was developed by the inventors. For details of the process, reference is made to U.S. Patent No. 61/216,374, filed May 15, 2009, and U.S. Patent No. 61/273,129, filed on Jul. 30, 2009. U.S. Patent No. 61/284,792, filed on December 26, 2009, U.S. Patent No. 12/587,290, filed on Oct. 5, 2009, and U.S. Patent No. 12/587,281, filed on October 5, 2009 And the U.S. Patent Application Serial No. 12/587,291, filed on Jan. 05, 2009, the entire disclosure of which is hereby incorporated by reference.

The electrostatic adsorption process used in the present invention can accurately control the phosphor powder coating density and the layer thickness. Alternatively, the electrostatic adsorption process can be repeated to form a plurality of uniform phosphor layers.

For example, a plurality of "particles composed of a phosphor powder and a binder" are formed on the heat conductive layer 13. The phosphor powder of the uniform phosphor layer 14 thus obtained occupies 75% or more of the volume of the uniform phosphor layer. Alternatively, the uniform phosphor layer 14 comprises a stack of a plurality of phosphor particles. Preferably, the phosphor particles in the uniform phosphor layer are not connected to other phosphor particles, and the uniform phosphor layer may include a cement layer formed after the electrostatic adsorption process (such as thickness). Less than 10 microns, not shown). The adhesive layer can be silicone, epoxy, glass, softens or any suitable material for LED packaging. For example, it has excellent moisture resistance properties, such as parylene, to avoid degradation of the phosphor or LED during wet/hot operating conditions.

Next, as shown in FIG. 1C, the light transmissive member 16 is placed on the carrier member 12, and the encapsulant 18 is injected to cover the LED die 10 and fix the light transmissive member 16. In addition to injection molding, the encapsulant may be formed by compression molding.

Second embodiment

Please refer to FIGS. 2A and 2B for explaining the LED package of the present invention. In the method of the second embodiment, the second embodiment is shown in FIG. 2B to form an encapsulant 18 covering the LED die 10 and fixing the transparent member 16 between the carrier 12 and the transparent member 16.

This embodiment is substantially the same as the foregoing embodiment, and the difference is mainly that the heat conductive layer 13 has the opening window 131.

As shown in FIGS. 2A and 2B, the heat conducting layer 13 is formed on the surface of the light transmitting member 16, and the heat conducting layer 13 has a window 131 corresponding to the position of the LED die 10, and the light transmitting member 16 is exposed. The uniform phosphor layer 14 is formed on the surface of the exposed light transmissive member 16 and covers a part of the heat conducting layer 13.

The heat conductive layer 13 of this embodiment can be obtained through a patterning process. When the uniform phosphor layer 14 is formed by electrostatic adsorption, a similar technique may be used. For example, a mask may be disposed under the surface of the light transmissive member, and a surface of a portion of the light transmissive member to be formed with a uniform phosphor layer may be exposed. This results in a uniform phosphor layer.

Since the uniform phosphor layer 14 or the recess 1200 is a relatively large target, the "alignment" of the uniform phosphor layer over the LED die does not mean that an extremely precise alignment is required. .

Third embodiment

Referring to FIGS. 3A and 3B , another method of fabricating the LED package of the present invention, wherein FIG. 3B shows that the LED die 10 is covered between the carrier 12 and the transparent member 16 and fixed. The encapsulant 18 of the light member 16.

This embodiment is substantially the same as the previous embodiment, and the difference is mainly that a portion of the uniform phosphor layer 14 is sandwiched between the light transmissive member 16 and the heat conductive layer 13.

As shown in FIG. 3A, the uniform phosphor layer 14 forms a portion of the surface of the light transmissive member 16 corresponding to the position of the LED die 10, and the heat conducting layer 13 is formed on the surface of the light transmissive member 16, and The portion of the uniform phosphor layer 14 is extended to cover.

Fourth embodiment

Please refer to FIGS. 4A to 4C for illustrating the LED package with the heat dissipation column 20 of the present invention, wherein the heat dissipation column 20 can be formed by electroplating after mechanical or laser perforation, and can avoid the channel structure. 1201.

As shown in FIG. 4A, the heat dissipating post 20 is disposed in the carrier 12 and is formed adjacent to the recess 1200. The heat dissipating post 20 is connected to the uniform phosphor layer 14.

As shown in FIGS. 4B and 4C, the structure of the second and third embodiments is continued. The heat dissipation post 20 is disposed in the carrier 12 and is formed adjacent to the cavity 1200. The heat dissipation column 20 is connected to the heat conduction. Layer 13.

Fifth embodiment

Referring to FIGS. 5A and 5B, the heat conductive layer 13 is formed on the spacer 120 in advance.

As shown in FIG. 5A, the heat conducting layer 13 is formed on at least a portion of the surface of the spacer 120, and the uniform phosphor layer 14 is formed on a surface of the portion of the light transmitting member 16 located above the LED die 10. Preferably, the uniform phosphor layer 14 has a slightly larger area than the pockets of the recess 1200.

As shown in FIG. 5B, the light transmissive member 16 is placed on the carrier member 12 to form a package covering the LED die 10 and fixing the light transmissive member 16 between the carrier member 12 and the light transmissive member 16. a colloid 18, wherein the heat conducting layer 13 is The uniform phosphor layer 14 is in contact.

Sixth embodiment

Referring to FIGS. 6A and 6B, the carrier 12 has a recess 1200 structure and a lead frame connecting the connecting portion 1202 of the recess 1200 structure, and the heat conducting layer 13 is formed on the surface of the connecting portion 1202.

As shown in FIG. 6A, the heat conducting layer 13 is formed on at least a surface of the connecting portion 1202. The uniform phosphor layer 14 is formed on a surface of a portion of the light transmitting member located above the LED die 10, and preferably The uniform phosphor layer 14 has a slightly larger area than the pocket 1200.

As shown in FIG. 6B, the light transmissive member 16 is placed on the lead frame to form an encapsulant 18 covering the LED die 10 and fixing the transparent member 16 between the lead frame and the transparent member 16. Wherein the heat conducting layer 13 is in contact with the uniform phosphor layer 14.

According to the foregoing method, the present invention provides an LED package, comprising: a carrier 12; at least one LED die 10 is disposed on the carrier 12; the encapsulant 18 is formed on the carrier 12 and packaged The light-emitting member 16 is formed on at least a portion of the surface of the light-emitting layer 14 and is disposed on the encapsulant 18, and the uniform phosphor layer 14 is located above the LED die 10; The heat conducting layer 13 is disposed between the carrier 12 and the light transmissive member 16, and the heat conducting layer 13 is in contact with the uniform phosphor layer 14.

In a specific embodiment, the heat conducting layer 13 is formed on the entire surface of the light transmissive member 16, and the uniform phosphor layer 14 is formed on the heat conducting layer 13 so that the heat conducting layer 13 is sandwiched between the uniform Between the light layer 14 and the light transmissive member 16.

In another embodiment, the heat conductive layer 13 is formed on the light transmissive member The surface of the light-transmissive member 13 has a fenestration 131 corresponding to the position of the LED die 10, and a portion of the surface of the light-transmitting member 16 is exposed. The uniform phosphor layer 14 is formed on the surface of the exposed light-transmitting member 16. And covering a portion of the heat conducting layer 13.

In another embodiment, the uniform phosphor layer 14 forms a portion of the surface of the light transmissive member 16 corresponding to the position of the LED die 10, and the heat conducting layer 13 is formed on the surface of the light transmissive member 16. And extending over a portion of the uniform phosphor layer 14.

In addition, in the embodiment in which the carrier 12 has the recess 1200, the heat sink 20 is disposed in the carrier 12 and is formed adjacent to the recess 1200, and the heat sink 20 is connected to the uniform phosphor layer. 14 or thermally conductive layer 13.

In another embodiment, the carrier 12 may be an integrally formed part, or the carrier 12 includes a substrate 121 and a spacer 120 disposed on the substrate 121. The spacer 120 is surrounded by the spacer 120. The pocket 1200 is connected to the surface of the carrier 12 and correspondingly houses the LED die 10 . In addition, the inner wall surface of the spacer 120 or the recess 1200 may be formed with a reflective layer (not shown) to concentrate light and prevent light from leaking. Further, the spacer 120 is formed by stacking metal or a plurality of nano carbon particles.

In another embodiment, the heat conducting layer 13 is formed on at least a portion of the surface of the spacer 120, and the uniform phosphor layer 14 has an area slightly larger than the cavity of the recess 1200, and the germanium is in contact with the heat conductive layer 13.

In another embodiment, the carrier 12 has a recess 1200 structure and a lead frame connecting the connecting portion 1202 of the recess 1200 structure, and the heat conducting layer 13 is formed on at least the surface of the connecting portion 1202.

In summary, the uniform fluorescent layer of the present invention forms a fluorescent particle or a phosphor powder and a bonding material on the surface of the light transmissive member by electrostatic adsorption, so that the obtained fluorescent layer is very uniform and provides excellent performance. Optical properties. In addition, when the fluorescent particles or the phosphor powder converts the wavelength of light emitted by the LED dies, heat is generated, and at the same time, the encapsulant is also heated, so that the fluorescent particles or the phosphor powder of the present invention are not included. The heat is applied to the encapsulant and the heat conductive layer having a better heat dissipation property is in contact with the uniform phosphor layer, so that heat can be dissipated to the outside.

The above examples are merely illustrative of the compositions and preparation methods of the present invention and are not intended to limit the invention. Modifications and variations of the above-described embodiments can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the claims of the present invention should be as set forth in the appended claims.

10‧‧‧LED dies

12‧‧‧ Carrying parts

121‧‧‧Substrate

120‧‧‧ spacers

1200‧‧‧ recess

1201‧‧‧channel structure

13‧‧‧Conducting layer

14‧‧‧ Even fluorescent layer

15‧‧‧Adhesive layer

16‧‧‧Light transmission parts

Claims (30)

The invention relates to a method for manufacturing an LED package, comprising: providing a carrier having at least one LED die on a surface; and placing a light-transmitting component having a uniform phosphor layer on a surface on the LED die, wherein The uniform phosphor layer is formed at least on a surface of the transparent member that is located above the LED die, and the heat conducting layer is formed on the carrier or the light transmitting member, and the heat conducting layer is located on the carrier and the light transmitting member And the uniform phosphor layer is located between the LED die and the light transmissive member; and an encapsulant covering the LED die and fixing the light transmissive member is formed between the carrier and the light transmissive member, And the encapsulant is located between the LED die and the uniform phosphor layer, wherein the thermally conductive layer is in contact with the uniform phosphor layer. The method of fabricating an LED package according to claim 1, wherein the heat conductive layer is a transparent carbonaceous layer comprising a plurality of nano carbon particles. The method of manufacturing the LED package of claim 1, wherein the heat conductive layer is formed on the entire surface of the light transmissive member, and the uniform phosphor layer is formed on the heat conductive layer to make the heat conductive layer Sandwiched between the uniform phosphor layer and the light transmissive member. The method of manufacturing the LED package of claim 1, wherein the heat conductive layer is formed on the surface of the light transmissive member, and the heat conductive layer has a window opening corresponding to the position of the LED die, and the through hole is exposed. The surface of the light member is formed on the surface of the exposed light transmissive member and covers a part of the heat conducting layer. The method of manufacturing the LED package of claim 1, wherein the uniform phosphor layer forms a portion of the surface of the light transmissive member corresponding to the position of the LED die, and the heat conductive layer is formed in the transparent layer. The surface of the light member is extended to cover a portion of the uniform phosphor layer. The method of manufacturing the LED package of claim 1, wherein the carrier has a cavity connected to the surface of the carrier and correspondingly accommodating the LED die. The method for manufacturing an LED package according to claim 6, wherein the carrier has a heat dissipating post therethrough, and is formed beside the recess. The method of manufacturing the LED package of claim 6, wherein the carrier comprises a substrate and a spacer disposed on the substrate, and the recess is surrounded by the spacer. The method of manufacturing the LED package of claim 8, wherein the spacer is formed by stacking metal or a plurality of nano carbon particles. The method of manufacturing the LED package of claim 8, wherein the heat conductive layer is formed on at least a part of the surface of the spacer, and the heat conductive layer is contacted with the uniform fluorescent layer after the encapsulant is formed. . The method of manufacturing the LED package of claim 6, wherein the carrier has a recess and a lead frame connecting the connection portion of the recess, and the heat conducting layer is formed on the surface of the connecting portion. After the encapsulant is formed, the thermally conductive layer is brought into contact with the uniform phosphor layer. For example, the method for manufacturing an LED package according to claim 1 is The uniform phosphor layer is formed on the surface of the light transmissive member by electrostatic adsorption. The method of fabricating an LED package according to claim 1, wherein the uniform phosphor layer comprises a phosphor powder and an adhesive material. The method of fabricating an LED package according to claim 13, wherein the phosphor powder of the uniform phosphor layer occupies 75% or more of the uniform phosphor layer. The method of fabricating an LED package according to claim 1, wherein the uniform phosphor layer comprises a stack of a plurality of phosphor particles. The method for manufacturing an LED package according to claim 1, wherein the encapsulant is formed by press molding or injection molding. An LED package includes: a carrier; at least one LED die is disposed on the carrier; a package colloid; is formed on the carrier and covers the LED die; at least part of the surface is formed a transparent member of the uniform phosphor layer is disposed on the encapsulant, and the uniform phosphor layer is located above the LED die, and the uniform phosphor layer is located between the LED die and the transmissive member And the encapsulant is located between the LED die and the uniform phosphor layer; and the heat conducting layer is located between the carrier and the light transmissive member, and the thermally conductive layer is in contact with the uniform phosphor layer. The LED package of claim 17, wherein the The heat conducting layer is a transparent carbonaceous layer comprising a plurality of nano carbon particles. The LED package of claim 17, wherein the heat conductive layer is formed on the entire surface of the light transmissive member, and the uniform phosphor layer is formed on the heat conductive layer to sandwich the heat conductive layer. Between the uniform phosphor layer and the light transmissive member. The LED package of claim 17, wherein the heat conductive layer is formed on the surface of the light transmissive member, and the heat conductive layer has a window opening corresponding to the position of the LED die, and the light transmissive member is exposed A portion of the surface is formed on the surface of the exposed light transmissive member and covers a portion of the thermally conductive layer. The LED package of claim 17, wherein the uniform phosphor layer forms a portion of the surface of the light transmissive member corresponding to the position of the LED die, and the heat conductive layer is formed on the light transmissive member On the surface, and extending over a portion of the uniform phosphor layer. The LED package of claim 17, wherein the carrier has a cavity connected to the surface of the carrier and correspondingly accommodating the LED die. The LED package of claim 22, wherein the carrier has a heat dissipating post therethrough, and is formed beside the recess. The LED package of claim 22, wherein the carrier comprises a substrate and a spacer disposed on the substrate, and the recess is surrounded by the spacer. The LED package of claim 24, wherein the spacer is formed by stacking metal or a plurality of nano carbon particles. The LED package of claim 24, wherein the thermally conductive layer is formed on at least a portion of a surface of the spacer. The LED package of claim 22, wherein the carrier has a recess structure and a lead frame connecting the connection portion of the recess structure, and the heat conductive layer is formed on at least the surface of the connecting portion. . The LED package of claim 17, wherein the uniform phosphor layer comprises a phosphor powder and an adhesive material. The LED package of claim 28, wherein the phosphor powder of the uniform phosphor layer occupies more than 75% of the volume of the uniform phosphor layer. The LED package of claim 17, wherein the uniform phosphor layer comprises a stack of a plurality of phosphor particles.