TWI472064B - 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 an LED package having a phosphor layer on an LED die and a method of fabricating the same.

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). A conventional method of depositing a phosphor material on a blue LED wafer or package assembly is, for example, a slurry method in which a phosphor powder is dispersed in a resin, epoxy or solvent fill material to form a phosphor. The mixture is applied to the surface of the LED dies 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 method is that the thickness uniformity of the phosphor layer on the surface of the LED die or inside the package in which the LED die is packaged may vary. The slurry process typically forms a layer of particles having varying thicknesses resulting in inconsistent light color points and poor color uniformity of the phosphor converted LED grains. Moreover, these conventional methods are difficult to form a uniform phosphor layer on a non-flat surface. Therefore, it is a considerable challenge to meet the requirements of lighting applications in the traditional way.

Conventional methods still have problems such as wasted phosphor, inconsistent light color points, poor color uniformity of the phosphor converted LED die, 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 a light emitting diode (LED) package, comprising: disposing at least one LED die on the carrier; forming a first encapsulant covering the sidewall of the LED die to make the LED crystal The granule and the first encapsulant integrally form an outer shape with a narrow bottom width; a uniform phosphor layer is formed on the first encapsulant; and a second encapsulant is formed on the uniform luminescent layer to form a transparent electrostatic adsorption The periphery of the phosphor layer is more uniform.

The present invention further provides an LED package comprising: at least one LED die; a first encapsulant covering a bottom of the at least one LED die sidewall and having a narrow top, and a bottom surface of the first encapsulant and the at least one The bottom surface of the LED die is flush; the uniform phosphor layer is formed on the first encapsulant; and the second encapsulant is formed on the uniform phosphor layer.

The uniform fluorescent layer of the present invention forms a phosphor particle or a phosphor powder on the LED die and the first encapsulant by electrostatic adsorption, so that the obtained phosphor layer is very uniform and provides excellent optical properties. In addition, because the bottom of the first encapsulant system has a narrow top and bottom, the problem that the thickness of the phosphor layer is uneven due to the deposition of the dead side of the LED die, or the excessive accumulation of the phosphor particles and the phosphor powder, thereby improving the LED package Optical properties.

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 also be embodied or applied by other different embodiments. The details in the present specification may also be based on different viewpoints and applications, and various modifications may be made without departing from the spirit of the present invention. With changes.

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", "side", "top", "bottom" and "at least one" are used in this specification for convenience of description only, and are not intended to limit the invention. The scope of the invention, the change or adjustment of its relative relationship, is also considered to be within the scope of the 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.

Also herein, the fluorescent particles may mean a phosphor powder, so that the uniform fluorescent layer may be formed by stacking a plurality of fluorescent particles; or the fluorescent particles may be referred to as including a phosphor powder and an adhesive material.

Example

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

As shown in FIG. 1A, at least one LED die 12 is provided on the carrier 10 in a flip chip manner. The carrier 10 can be a substrate or a release film, wherein the substrate can also have a line, or the bottom surface of the substrate can have an electrical connection pad to electrically connect the LED die 12 and can be electrically connected. Padded to external components.

As shown in FIG. 1B, a first encapsulant 14 having a narrow bottom width is formed on the carrier 10 to cover the side of the LED die 12. In this embodiment, the LED die 12 and the first encapsulant 14 are not trapped as a whole, and the first encapsulant 14 is formed to form a gentle slope between the top surface of the LED die 12 and the carrier 10. can.

Referring to FIG. 1B', the first encapsulant 14 is formed on the top surface of the LED die 12.

As shown in FIG. 1C, following the structure of FIG. 1B, a uniform phosphor layer 16 is formed on the top surface of the first encapsulant 14 and the LED die 12 by electrostatic adsorption.

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 US Patent Case No. 12/587,291 The full text of the summary and the merger is incorporated herein 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 layer includes a phosphor powder and a binder. For example, a plurality of fluorescent particles or a plurality of phosphor powders and adhesive material particles are formed on the first encapsulant and the top surface of the LED die. The phosphor powder of the uniform phosphor layer thus obtained occupies more than 75% of the volume of the uniform phosphor layer. In this embodiment, each of the phosphor particles comprises a phosphor powder and an adhesive material.

In another embodiment, 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.

As shown in FIG. 1D, a second encapsulant 18 is formed on the uniform phosphor layer 16. The second encapsulant 18 has a lens structure as shown in the package structure on the left side. Of course, the second encapsulant 18 can have other shapes.

Further, the carrier 10 can be removed to obtain an LED package as shown in FIG. 1E.

According to the LED package shown in FIG. 1E, the bottom surface of the LED die 12 The electrode pad is exposed to expose the first encapsulant 14 .

According to the foregoing method, the LED package of the present invention comprises: at least one LED die 12, a first encapsulant 14, a uniform phosphor layer 16, and a second encapsulant 18.

The first encapsulant 14 is narrow at the bottom and covers the sidewall of the at least one LED die 12, and the bottom surface of the first encapsulant 14 is flush with the bottom surface of the LED die 12.

The uniform phosphor layer 16 is formed on the first encapsulant 14 , and the second encapsulant 18 is formed on the uniform phosphor layer 16 .

In addition, according to the aspect of the 1B', the first encapsulant 14 can cover the top surface of the LED die 12.

In summary, the uniform phosphor layer of the present invention forms a phosphor particle or a phosphor powder on the LED die and the first encapsulant by electrostatic adsorption, so that the obtained phosphor layer is very uniform and can be provided. Excellent optical properties. In addition, because the bottom of the first encapsulant system has a narrow top and bottom, the problem that the thickness of the phosphor layer is uneven due to the deposition of the dead side of the LED die, or the excessive accumulation of the phosphor particles and the phosphor powder, thereby improving the LED package Optical properties.

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‧‧‧ Carrier

12‧‧‧LED dies

14‧‧‧First encapsulant

16‧‧‧Uniform luminescent layer

18‧‧‧Second encapsulant

1A to 1E are schematic views showing the process of manufacturing the LED package of the present invention, wherein the 1B' diagram shows another formation of the first encapsulant.

10‧‧‧ Carrier

12‧‧‧LED dies

14‧‧‧First encapsulant

Claims (15)

A method for manufacturing a light emitting diode (LED) package includes: disposing at least one LED die on a carrier; forming a first encapsulant having a bottom width and a narrow top to encapsulate the LED die on the carrier a sidewall; forming a uniform phosphor layer on the first encapsulant; and forming a second encapsulant on the uniform phosphor layer. The method of fabricating an LED package according to claim 1, wherein the uniform phosphor layer is formed on the first encapsulant and the LED die 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 is formed by stacking a plurality of phosphor particles. The method of manufacturing the LED package of claim 5, wherein each of the phosphor particles comprises a phosphor powder and an adhesive material. The method of manufacturing the LED package of claim 1, wherein the first encapsulant is formed on the top surface of the LED die. The method of fabricating an LED package according to claim 1, wherein the second encapsulant system has a lens structure. An LED package comprising: At least one LED die; a first encapsulant having a narrow bottom width, covering a sidewall of the at least one LED die, and a bottom surface of the first encapsulant is flush with a bottom surface of the at least one LED die; The light layer is formed on the first encapsulant; and the second encapsulant is formed on the uniform phosphor layer. The LED package of claim 9, wherein the uniform phosphor layer comprises a phosphor powder and an adhesive material. The LED package of claim 10, 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 9, wherein the uniform phosphor layer is formed by stacking a plurality of phosphor particles. The LED package of claim 12, wherein each of the phosphor particles comprises a phosphor powder and an adhesive material. The LED package of claim 9, wherein the first encapsulant covers the top surface of the LED die. The LED package of claim 9, wherein the second encapsulant system has a lens structure.