TWI455372B - Led package and the method for forming 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). Traditional methods of depositing phosphor material over a blue LED wafer or package assembly include:

Slurry method: The phosphor powder is dispersed in a resin, epoxy resin or solvent-filled material to form a phosphor mixture by spraying or dispensing coating or dispensing or phosphor powder in the cup or Various techniques, such as molding on a support structure, apply the phosphor mixture to the surface of the LED.

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, the ruthenium resin coats the phosphor powder so that the heat generated by the phosphor powder is not transmitted to the outside, which easily causes deterioration of the phosphor powder and affects optical properties. Therefore, meeting these requirements in lighting applications with these traditional methods faces considerable challenges.

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 positioning a light-transmitting member having a uniform phosphor layer on the LED die, The LED die is disposed between the carrier 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.

The present invention further 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; and having uniform fluorescence The transparent member of the layer is disposed on the encapsulant and covers the at least one LED die.

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, so that the fluorescent particles or the phosphor powder of the present invention are not coated in the encapsulant, and are tied to The light transmissive member is in contact, so that heat can be dissipated to the outside.

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, refers to all materials having 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.

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.

As shown in FIG. 1B, a light-transmitting member 16 having a uniform phosphor layer 14 is positioned on the LED die 10 such that the LED die 10 is positioned between the carrier 12 and the light-transmitting member 16; An encapsulant 18 covering the LED die 10 and fixing the transparent member 16 is formed between the carrier 12 and the transparent member 16.

Specifically, the uniform phosphor layer 14 of the present invention can be formed on a portion of the surface of the light transmissive member 16 as shown in FIG. 1B, and corresponds to the position of the recess 1200. In this embodiment, the uniform phosphor layer 14 is formed on the bottom surface of the light transmissive member 16 to be located between the carrier member 12 and the light transmissive member 16. When the uniform phosphor layer 14 is formed by electrostatic adsorption, a surface of the light transmissive member 16 may be provided with a mask, and the surface of the portion of the light transmissive member 16 to be formed with the uniform phosphor layer 14 is exposed, so that uniform fluorescence can be obtained. Layer 14. Of course, a uniform phosphor layer 14 can also be formed on the entire surface of the light transmissive member 16.

Since the uniform phosphor layer 14 or the recess 1200 is a relatively large target, the aforementioned "alignment" does not mean extremely precise alignment, but only when forming the encapsulant 18, such as injection molding, such as As shown in FIG. 1C, the light transmissive member 16 is placed on the carrier member 12, and the encapsulant 18 is injected. Further, as shown in Fig. 1C', a protective film 19 such as enamel resin may be formed on the light-transmitting member 16 to protect the uniform fluorescent layer 14.

The aforementioned electrostatic adsorption system was developed by the inventors. For details of the process, refer to US Patent No. 61/216,374, filed May 15, 2009, US Patent No. 61/273,129, filed on July 30, 2009, and No. 61, filed on December 26, 2009 US Patent No. 284,792, US Patent No. 12/587,290, filed on Oct. 5, 2009, and U.S. Patent No. 12/587,281, filed on October 5, 2009, and filed on October 5, 2009 U.S. Patent Application Serial No. 12/587,291, the entire disclosure of which is incorporated herein in its entirety 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. The uniform phosphor layers 14a, 14b, 14a', 14b' are shown in Figs. 2A and 2B. Furthermore, the uniform phosphor layer of the present invention comprises a phosphor powder and an adhesive material. For example, a plurality of "particles composed of a phosphor powder and a binder" or a plurality of phosphor powders and binder particles are formed on the light-transmitting member 16. The phosphor powder of the uniform phosphor layer thus obtained occupies more than 75% of the volume of the uniform phosphor layer.

In another aspect, the uniform phosphor layer is formed by stacking a plurality of phosphor particles, and preferably, the phosphor particles in the uniform phosphor layer are not connected to other phosphor particles, and the uniformity is uniform. The phosphor layer may include a cement layer formed after the electrostatic adsorption process (eg, having a thickness of 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.

Second embodiment

Please refer to Figures 3A and 3B, which are another method of fabricating the LED package of the present invention. This embodiment is substantially the same as the foregoing embodiment, and the difference is mainly that the carrier 32 is a substrate.

As shown in FIG. 3A, the carrier 32 is provided with a plurality of LED dies 30. When the encapsulant 38 is formed, the transparent member 36 can be disposed above the carrier 32, and then formed by injection molding. The colloid 38 is between the uniform phosphor layer 34 and the carrier 32 to encapsulate the LED die 30 as shown in FIG. 3B.

Third embodiment

Referring to Figures 4A through 4E, the structure of the light transmissive member of the present invention will be described.

As shown in FIG. 4A, since the light transmissive member can be made of, for example, glass, when the uniform phosphor layer 44 is formed on the bottom surface of the light transmissive member 46a, the translucent member 46a can be made of frosted glass. The top surface of the light member 46a has a roughness 461.

As shown in FIG. 4B, the top surface of the light transmissive member 46b has an arcuate convex portion 462 corresponding to the LED die. As shown in Fig. 4B', the uniform phosphor layer 44 may be formed over the entire surface of the light transmissive member 46b.

As shown in FIGS. 4C and 4D, the light transmitting member 46c is an arcuate convex portion 463 having a wavy convex shape. Further, the uniform fluorescent layer 44 may be formed on the top surface or the bottom surface of the light transmitting member 46c.

As shown in FIG. 4E, the bottom surface of the light transmissive member 46d has a bottom convex portion 464 corresponding to the LED die. The uniform phosphor layer 44 can be formed on the bottom protrusion 464.

Fourth embodiment

Referring to Figures 5A and 5B, when fabricating the LED package of the present invention, a plurality of light-transmissive members 16' having a smaller size can be used, for example, the size of the recess 1200 can be covered, and each package unit can be covered for transmission. The method of the first embodiment 1C or 1C' forms an encapsulant 18 that encapsulates the LED die 10 and secures the light transmissive member 16'.

Fifth embodiment

Referring to Figures 6A and 6B, if the array type large-area package is not used, it can be changed to a small size, for example, only the light-transmitting member 16' for covering a single package unit size, on the LED die 10, The LED die 10 is disposed between the carrier 12 ′ and the light transmissive member 16 ′, and then the LED die 10 is covered between the carrier 12 ′ and the transparent member 16 ′ and the light is fixed. The encapsulant 18 of the piece 16'. In addition, since the uniform phosphor layer 14 is formed on the bottom surface of the light transmissive member 16', the light transmissive member 16' can be made of frosted glass, so that the top surface of the light transmissive member 16' has a rough structure 161. Of course, the use of frosted glass can be selected depending on the formation position of the uniform phosphor layer 14.

According to the foregoing method, the present invention provides an LED package comprising: a carrier 12, 12', 32; at least one LED die 10, 30, which is disposed on the carrier 12, 12', 32; the encapsulant 18 , 38; formed on the carrier 12, 12', 32, and covering the LED die 10, 30; and having a uniform phosphor layer 14, 14a, 14b, 14a', 14b', 34, 44 The light transmissive members 16, 16', 36, 46a, 46b, 46c, 46d are disposed on the encapsulant and cover the at least one LED die 10, 30.

The carrier 12 has a recess 1200 that communicates with the surface of the carrier 12 and correspondingly houses the LED die 10. In addition, the surface of the carrier 12 may be formed with a channel structure 1201.

In the embodiment having the recess, the carrier 12 can include a substrate 121 and a spacer 120 disposed on the substrate 121, and the recess 1200 is surrounded by the spacer 120. In addition, the uniform phosphor layer 14 may be formed on the entire surface of the light transmissive member 16, such as a top surface, a bottom surface or a top surface and a bottom surface, and the uniform phosphor layer 14 may be formed only on a part of the surface of the light transmissive member 16. That is, the corresponding position of the pocket 1200.

For example, when the uniform fluorescent layer 44 is formed on the bottom surface of the light transmitting member 46a to be positioned between the carrier and the light transmitting member, the light transmitting member 46a is preferably frosted glass.

As shown in Figures 4B to 4D, the top surfaces of the light transmissive members 46b, 46c have arcuate projections 462, 463 corresponding to the LED dies. As shown in FIG. 4E, the bottom surface of the light transmissive member 46d has a bottom convex portion 464 corresponding to the LED die.

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, so that the fluorescent particles or the phosphor powder of the present invention are not coated in the encapsulant, and are tied to The light transmissive member is in contact, 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.

10,30. . . LED die

12,12’,32. . . Carrier

121. . . Substrate

120. . . Spacer

1200. . . Pocket

1201. . . Channel structure

14,14a, 14b, 14a', 14b', 34, 44. . . Uniform phosphor layer

16,16’, 36, 46a, 46b, 46c, 46d. . . Translucent member

18,38. . . Encapsulant

19. . . Protective film

461,161. . . Rough structure

462,463. . . Curved convex

464. . . Bottom convex

1A to 1C are schematic views showing the manufacturing method of the LED package of the present invention, wherein the 1A' drawing is a top view of the 1A; the 1C' is a schematic view showing the protective film formed on the transparent member;

2A and 2B are schematic views showing the formation of a plurality of uniform phosphor layers on the light transmissive member;

3A and 3B are diagrams showing a method of fabricating another LED package of the present invention;

4A to 4E are views showing the structure of the light transmissive member of the present invention, wherein the 4B' pattern shows that the uniform phosphor layer is formed over the entire surface of the light transmissive member;

5A and 5B are diagrams showing the method of manufacturing the LED package of the fourth embodiment of the present invention;

6A and 6B are diagrams showing the method of manufacturing the LED package of the fifth embodiment of the present invention.

10. . . LED die

12. . . Carrier

121. . . Substrate

120. . . Spacer

1200. . . Pocket

1201. . . Channel structure

14. . . Uniform phosphor layer

16. . . Translucent member

18. . . Encapsulant

Claims (28)

The invention relates to a method for manufacturing an LED package, comprising: providing a carrier having at least one LED die on a surface thereof; and having a transparent phosphor layer on the surface is disposed on the LED die to make the LED crystal The granule is located between the carrier 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. The method of manufacturing an LED package according to claim 1, wherein 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 3, 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 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 of manufacturing an LED package according to claim 6, wherein the surface of the carrier is formed with a channel structure. The method for manufacturing an LED package according to claim 6 of the patent application, The carrier includes a substrate and a spacer disposed on the substrate, and the recess is surrounded by the spacer. The method of fabricating an LED package according to claim 6, wherein the uniform phosphor layer is formed on a surface of the light transmissive member and corresponds to a recessed position. The method of manufacturing the LED package of claim 1, wherein the uniform phosphor layer is formed on a bottom surface of the light transmissive member to be located between the carrier and the light transmissive member. The method of manufacturing an LED package according to claim 10, wherein the light transmissive member is frosted glass. The method of manufacturing the LED package of claim 1, wherein the uniform phosphor layer is formed on a top surface of the light transmissive member, such that the light transmissive member is located between the uniform phosphor layer and the carrier. . The method of manufacturing the LED package of claim 1, wherein the top surface of the light transmissive member has an arcuate convex portion corresponding to the LED die. The method of manufacturing the LED package of claim 1, wherein the bottom surface of the light transmissive member has a bottom convex portion corresponding to the LED die. 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; the encapsulant is formed on the carrier and covers the LED die; A light transmissive member having a uniform phosphor layer on the surface is disposed on the encapsulant and covers the at least one LED die. The LED package of claim 16, wherein the uniform phosphor layer comprises a phosphor powder and an adhesive material. The LED package of claim 17, 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 16, wherein the uniform phosphor layer comprises a stack of a plurality of phosphor particles. The LED package of claim 16, wherein the carrier has a cavity connected to the surface of the carrier and correspondingly accommodating the LED die. The LED package of claim 20, wherein the surface of the carrier is formed with a channel structure. The LED package of claim 20, 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 20, wherein the uniform phosphor layer is formed on a surface of the light transmissive member and corresponds to a recessed position. The LED package of claim 16, wherein the uniform phosphor layer is formed on a bottom surface of the light transmissive member to be located between the carrier and the light transmissive member. The LED package of claim 24, wherein the The light transmitting member is frosted glass. The LED package of claim 16, wherein the uniform phosphor layer is formed on a top surface of the light transmissive member such that the light transmissive member is located between the uniform phosphor layer and the carrier. The LED package of claim 16, wherein the top surface of the light transmissive member has an arcuate convex portion corresponding to the LED die. The LED package of claim 16, wherein the bottom surface of the light transmissive member has a bottom convex portion corresponding to the LED die.