TW201320405A - High power LED encapsulation structure and its fabrication method - Google Patents

Abstract

Disclosed are a high power LED encapsulation structure and its fabrication method, wherein the encapsulation structure comprising: a cup-like ceramic substrate with a groove, a wiring metal layer, a reflection metal layer, an LED and an encapsulant. The high thermal conductivity of the ceramic substrate can effectively transmit heat to the exterior to prolong the service life of the LED. In addition, by using a cup-like structure, a horizontal or vertical LED is disposed in the groove, such that the electrical insulation of the ceramic substrate can be used for LED connection with the use of electrically conductive heat dissipation adhesive or metal eutectic bonding, thereby further providing a three-dimensional encapsulation structure which is suitable for the horizontal and vertical encapsulation. In addition, a metal layer is coated on the side wall of the groove to increase the light extraction and increase the light output of the LED.

Description

High-power light-emitting diode package structure and manufacturing method thereof

The invention relates to a high-power light-emitting diode package structure and a manufacturing method thereof, in particular to a cup-shaped ceramic substrate having a groove.

In recent years, with the rising awareness of global environmental protection, energy saving has become a trend today. The Light-Emitting Diode (LED) industry is one of the most watched industries in recent years. Up to now, LED products have the advantages of energy saving, power saving, high efficiency, fast reaction time, long life cycle, and no mercury, and have environmental benefits. Usually, the power of the LED exceeds 1W, which is called high power, and the input power of the product is about 20%, which can be converted into light, and the remaining 80% of the electric energy is converted into heat.

In general, if the thermal energy generated by LED illumination cannot be exported, the junction temperature of the LED components will be too high, which will affect the product life cycle. The LED heat-dissipating substrate mainly utilizes the heat-dissipating substrate material itself to have better thermal conductivity, and the heat source is derived from the LED die.

Referring to the first figure, a schematic cross-sectional view of a conventional horizontal LED package structure is shown. The conventional horizontal LED package structure 1 includes a circuit substrate 10, a circuit layer 31, an insulating paste 33, and an encapsulant 40. The circuit layer 31 is adhered to the circuit substrate 10 through the insulating adhesive 33, and the LED is printed. The body 100 is connected to the circuit layer 31 and connected to other portions of the circuit layer 31 through the wires 50, and is separated by an insulating paste 33 to avoid short circuit. However, the insulating adhesive 33 is a substance having poor heat transfer property and is intolerant. The high voltage impact, high voltage impact can achieve an improvement by increasing the thickness of the insulating paste 33, but the heat transfer property is relatively deteriorated.

At present, there is also a method of using a ceramic substrate for packaging. However, the current ceramic substrate is still mounted on a ceramic substrate in such a manner that the above-described structure is formed as a lead frame, which requires multiple assembly and problems of the original structure. It is also impossible to completely improve, and therefore, there is a need for a heat sink structure having good heat transfer properties and high voltage surge resistance.

The main object of the present invention is to provide a high-power light-emitting diode package structure, which can be applied to a horizontal-type vertical light-emitting diode package structure, the structure comprising: a ceramic substrate, a cup-shaped ceramic body, and having at least one a recess; a line metal layer formed on at least one of an upper surface and a lower surface of the ceramic substrate, electrically connected to the external circuit; a reflective metal layer formed on the sidewall of the at least one recess; at least one light emitting diode, Providing and bonding to the bottom of the at least one recess by at least one conductive heat dissipating adhesive or at least one metal eutectic layer, and connecting to the wiring metal layer through at least one wire; and an encapsulant for coating the a reflective metal layer, the at least one conductive heat dissipating adhesive or the at least one metal eutectic layer, the at least one light emitting diode, the at least one wire and a portion of the wiring metal layer, wherein the at least one light emitting diode The power is greater than 1W.

Another object of the present invention is to provide a high-power light-emitting diode package structure, comprising: a ceramic substrate, which is a cup-shaped ceramic body, and has at least one groove and a plurality of through holes, and the through holes are filled with metal a wiring metal layer formed at least on a lower surface of the ceramic substrate, electrically connected to an external circuit, and connected to a metal in the through holes; a reflective metal layer formed on a sidewall of the at least one groove, and the same a metal connection in the hole; a connection metal layer formed on at least the upper surface of the ceramic substrate and connected to the reflective metal layer; at least one light emitting diode disposed by at least one conductive heat dissipating adhesive or at least one metal eutectic layer And bonding to the bottom of the at least one recess and connecting to the connecting metal layer through at least one wire; and an encapsulant for covering the reflective metal layer, the connecting metal layer, the at least one conductive heat dissipating adhesive or At least one metal eutectic layer, the at least one light emitting diode, and the at least one wire, wherein the at least one light emitting diode has a power greater than 1 W.

Another object of the present invention is to provide a method for fabricating a high power light emitting diode package structure, the method comprising: a metal plating step, at least one of an upper surface and a lower surface of a ceramic substrate having at least one recess Plated with a metal layer; a patterning step of patterning the metal layer to form at least a line metal layer and a reflective metal layer, the line metal layer being formed on at least the upper surface and the lower surface of the ceramic substrate And the reflective metal layer is formed on the sidewall of the at least one recess; in the bonding step, the at least one light emitting diode is connected to the ceramic substrate by using at least one conductive heat dissipating adhesive or at least one metal eutectic layer At least one recess; a wire bonding step of connecting the at least one light emitting diode to the wiring metal layer by at least one wire; and a sealing step of coating the reflective metal layer with the at least one conductive heat sink a glue or at least one metal eutectic layer, the at least one light emitting diode, and the at least one wire.

The high-power light-emitting diode package structure and the manufacturing method thereof have the advantages of high heat conduction property of the ceramic substrate, can effectively transmit the heat source generated by the light-emitting diode to the outside, and prolong the use of the light-emitting diode. Lifetime, in addition, by means of a cup-like structure, a light-emitting diode is arranged in the groove. Since the ceramic substrate is electrically insulating, conductive heat-dissipating stickers such as gold glue, silver glue, tin glue, carbon glue, graphite glue, etc. can be used. Bonding or at least one metal eutectic layer to connect the light emitting diodes, further enclosing the package structure, suitable for horizontal and vertical packaging, and further, plating the metal layer on the sidewall of the groove Increase the reflection effect and improve the light output of the LED.

The implementation of the present invention will be described in more detail below with reference to the drawings and component symbols, so that those skilled in the art can implement the present specification after studying the present specification.

Referring to FIG. 2A, a cross-sectional view of a first embodiment of a high power light emitting diode package structure of the present invention is shown. As shown in FIG. 2A, the high power LED package structure 2 of the first embodiment of the present invention comprises a ceramic substrate 12, a line metal layer 25, a reflective metal layer 27, at least one crystal solid layer 32, at least one The light emitting diode 100, the encapsulant 40 and at least one wire 50. The ceramic substrate 12 is a cup-shaped ceramic body, which is generally formed by at least one of tantalum nitride, aluminum nitride, boron nitride, and tantalum carbide. The ceramic substrate 12 has at least one groove 14 and a groove. 14 can be formed simultaneously with the same ceramic substrate 12, or can be formed by patterning by lithography, or by laser or plasma etching, only a groove is used in the illustration. Represents but is not limited to this.

The wiring metal layer 25 is formed on the upper surface of the ceramic substrate 12, and is electrically connected to an external circuit. The reflective metal layer 27 is formed on the sidewall of the recess 14 for reflecting the light emitted by the LED 201. The power is greater than 1 W, and the die-solid layer 32 is disposed at the bottom of the recess 14 and is connected to the line metal layer 25 through the wire 50. The at least one die-solid layer 32 is a conductive heat-dissipating adhesive, such as gold glue. , silver glue, tin glue, carbon glue, graphite glue, etc., or a metal eutectic layer for connecting the light emitting diode 100 to the bottom of the groove 14. The encapsulant 40 is at least one of epoxy resin and cerium oxide, and is formed on the upper surface of the ceramic substrate 12 to cover the reflective metal layer 27, the crystal solid crystal layer 32, the light emitting diode 100, and the wire 50. And a portion of the wiring metal layer 25.

Referring to FIG. 2B, a cross-sectional view of a second embodiment of the high power light emitting diode package structure of the present invention is shown. As shown in FIG. 2B, the high power light emitting diode package structure 3 of the second embodiment of the present invention is similar in structure to the high power light emitting diode package structure 2 of the first embodiment, but the second embodiment The ceramic substrate further has a plurality of through holes 16 filled with metal, the wires 50 are connected to the connection metal layer 29 on the upper surface of the ceramic substrate 12, and the line metal layer 25 is disposed on the lower surface of the ceramic substrate 12 through the filling The metal of the through-hole 16 is connected to the connection metal layer 29 such that the light-emitting diode 100 transmits the metal in the through-hole 16 through the connection metal layer 29 and the line formed on the lower surface of the ceramic substrate. The metal layer 25 is electrically connected. The through holes 16 may be formed simultaneously with the ceramic substrate 12, or may be formed by patterning by lithography, or by laser or plasma etching, the wiring metal layer 25, The reflective metal layer 27, the connection metal layer 29, the metal filled in the via hole 16, and the metal eutectic layer are at least one of copper, aluminum, molybdenum, chromium, gold, silver, nickel, and tungsten.

Referring to FIG. 2C, a cross-sectional view of a third embodiment of the high power light emitting diode package structure of the present invention is shown. As shown in FIG. 2C, the high power light emitting diode package structure 4 of the third embodiment of the present invention is similar in structure to the high power light emitting diode package structure 2 of the first embodiment, but the third embodiment The ceramic substrate further has a plurality of through holes 16 filled with metal, and the line metal layer 25 is simultaneously disposed on the upper surface and the lower surface of the ceramic substrate 12, and the wiring metal layer 25 on the lower surface of the ceramic substrate 12 passes through the through holes. The metal in 16 is connected to the crystal grain-forming layer 32 and further connected to the light-emitting diode 100.

Referring to the third figure, a flow chart of a method for fabricating a high power light emitting diode package structure of the present invention. As shown in the third figure, the manufacturing method S1 of the high power light emitting diode package structure of the present invention comprises a metal plating step S10, a patterning step S20, a bonding step S30, a wire bonding step S40, and a glue sealing step S50. The metal plating step S10 is to plate a metal layer 20 on at least one of the upper surface and the lower surface of the ceramic substrate 12 having the recesses 14, and when the ceramic substrate 12 has the holes 16, the metal layer 20 fills the holes 16 The metal plating layer may be at least one of electroplating, electroless plating, evaporation, and sputtering, and the metal layer plating structure is completed, such as the fourth A diagram, or the fourth B diagram, or the fourth C. The figure shows.

The patterning step S20 is to pattern the metal layer 20 by photoresist coating, development, etching, or photoresist removal, or to pattern the metal layer 20 by laser removal or plasma etching to form a line metal. Layer 25 and reflective metal layer 27 are as shown in Figure AA. Alternatively, as shown in FIG. 5B, after patterning, the wiring metal layer 25, the reflective metal layer 27, and the connection metal layer 29 are formed, and the connection metal layer 25 is connected to the wiring metal layer 25 through the metal filled in the via hole 16. . Further, the wiring metal layer 25 may be patterned by the metal layer 20 of the upper surface and the lower surface, as shown in FIG. 5C, and the wiring metal layer 25 of the lower surface is connected to the metal in the via hole 16.

The bonding step S30 is to connect the light emitting diode 100 in the recess 14 of the ceramic substrate 12 by means of a die-bonding layer 32 by adhesive bonding or metal eutectic, as shown in FIG. 6A or sixth B. Figure, or Figure 6C. The wire bonding step S40 is to connect the light emitting diode 100 with the wire 50 to the wiring metal layer 25, as shown in FIG. 7A, or the seventh B, or the seventh C. The sealing step S50 is to coat the reflective metal layer 27, the crystal solid layer 32, the light emitting diode 100, the wire 50, or a part of the wiring metal layer 25 with the encapsulant 40, as shown in FIG. Figure 8B, or Figure 8C.

The high-power light-emitting diode package structure and the manufacturing method thereof have the advantages of high heat conduction property of the ceramic substrate, can effectively transmit the heat source generated by the light-emitting diode to the outside, and prolong the use of the light-emitting diode. Lifetime, in addition, by means of a cup-like structure, a light-emitting diode is arranged in the groove. Since the ceramic substrate is electrically insulating, conductive heat-dissipating stickers such as gold glue, silver glue, tin glue, carbon glue, graphite glue, etc. can be used. A glue or metal eutectic layer is used to connect the light-emitting diodes, and is capable of withstanding voltage shock and further encapsulating the package structure, and is suitable for horizontal and vertical packaging methods, and further, metal layer is formed on the sidewall of the groove. The plating can increase the reflection effect and improve the light output of the LED.

The above is only a preferred embodiment for explaining the present invention, and is not intended to limit the present invention in any way, and any modifications or alterations to the present invention made in the spirit of the same invention. All should still be included in the scope of the intention of the present invention.

1. . . Light emitting diode package structure

2. . . High power LED package structure

3. . . High power LED package structure

4. . . High power LED package structure

10. . . Circuit substrate

12. . . Ceramic substrate

14. . . Groove

16. . . Through hole

25. . . Line metal layer

27. . . Reflective metal layer

29. . . Connecting metal layer

31. . . Circuit layer

32. . . Grain solid layer

33. . . Insulating glue

40. . . Packaging adhesive

50. . . wire

100. . . Light-emitting diode

S1. . . Method for manufacturing high power light emitting diode package structure

S10. . . Metal plating step

S20. . . Patterning step

S30. . . Bonding step

S40. . . Wire step

S50. . . Sealing step

The first figure is a schematic cross-sectional view of a conventional horizontal LED package structure.

2A is a cross-sectional view showing a first embodiment of a high power light emitting diode package structure of the present invention.

FIG. 2B is a cross-sectional view showing a second embodiment of the high power light emitting diode package structure of the present invention.

FIG. 2C is a cross-sectional view showing a third embodiment of the high power light emitting diode package structure of the present invention.

The third figure is a flow chart of a method for manufacturing a high power light emitting diode package structure of the present invention.

4A to 4C, 5A to 5C, 6A to 6C, seventh to seventh C, and eighth to eighth C are diagrams for explaining a stepwise cross-section of the third diagram, The fourth A picture, the fifth A picture, the sixth A picture, the seventh A picture, and the eighth A picture are the first embodiment, the fourth B picture, the fifth B picture, the sixth B picture, and the seventh B picture. And FIG. 8B is a second embodiment, and the fourth C, fifth C, sixth C, seventh C, and eighth C are third embodiments, which are described herein.

2. . . High power LED package structure

12. . . Ceramic substrate

14. . . Groove

25. . . Line metal layer

27. . . Reflective metal layer

32. . . Grain solid layer

40. . . Packaging adhesive

50. . . wire

100. . . Light-emitting diode

Claims (16)

A high-power light-emitting diode package structure comprising: a ceramic substrate, a cup-shaped ceramic body, and having at least one groove; a line metal layer formed at least on an upper surface of the ceramic substrate and electrically connected to an external circuit; a reflective metal layer is formed on the sidewall of the at least one recess; at least one light emitting diode is disposed at the bottom of the at least one recess by at least one die-solid layer, and transmits the at least one wire to the line a metal layer connection; and an encapsulant for coating the reflective metal layer, the at least one crystal solid layer, the at least one light emitting diode, the at least one wire, and a portion of the wiring metal layer, wherein The power of at least one of the light emitting diodes is greater than 1W. The package structure of claim 1, wherein the circuit metal layer is further formed on a lower surface of the ceramic substrate, and the ceramic substrate has a plurality of through holes, and a metal is filled in the through holes, and The circuit layer on the lower surface of the ceramic substrate is connected to the at least one crystal grain-forming layer through the metal in the through holes, and is further connected to the at least one light-emitting diode. The package structure according to claim 1, wherein the ceramic substrate is made of at least one of tantalum nitride, aluminum nitride, boron nitride, and tantalum carbide, the at least one crystal solid layer a conductive heat-dissipating adhesive or a metal eutectic layer, the wiring metal layer, the reflective metal layer, the metal filled in the through holes, and the metal eutectic layer are copper, aluminum, molybdenum, chromium, gold At least one of silver, nickel, and tungsten. The encapsulant is at least one of epoxy resin and cerium oxide. The at least one conductive heat-dissipating adhesive is gold, silver, tin, or carbon. At least one of graphite glue. The package structure according to claim 1, wherein the groove is formed simultaneously when the ceramic substrate is formed, or is subsequently patterned by lithography etching, or formed by laser or plasma etching. . The package structure of claim 2, wherein the through holes are formed simultaneously with the ceramic substrate, or are subsequently patterned by lithography, or by laser or plasma. Etching to form. A high-power light-emitting diode package structure comprising: a ceramic substrate, a cup-shaped ceramic body, and having at least one groove and a plurality of through holes, wherein the through holes are filled with metal; and a line metal layer, at least Formed on a lower surface of the ceramic substrate, electrically connected to an external circuit, and connected to the metal in the through holes; a reflective metal layer formed on the sidewall of the at least one groove; and a connecting metal layer formed at least in the ceramic The upper surface of the substrate is connected to the metal in the through holes; at least one light emitting diode is disposed at the bottom of the at least one groove by at least one die-solid layer, and is connected to the wire through the at least one wire a metal layer connection; and an encapsulant for coating the reflective metal layer, the connection metal layer, the at least one crystal solid layer, the at least one light emitting diode, and the at least one wire, wherein the at least one The power of the light-emitting diode is greater than 1W. The package structure according to claim 6, wherein the ceramic substrate is made of at least one of tantalum nitride, aluminum nitride, boron nitride, and tantalum carbide, the at least one crystal solid layer a conductive heat-dissipating adhesive or a metal eutectic layer, the wiring metal layer, the reflective metal layer, the metal filled in the through holes, and the metal eutectic layer are copper, aluminum, molybdenum, chromium, gold At least one of silver, nickel, and tungsten. The encapsulant is at least one of epoxy resin and cerium oxide. The at least one conductive heat-dissipating adhesive is gold, silver, tin, or carbon. At least one of graphite glue. The package structure according to claim 6, wherein the groove is formed simultaneously when the ceramic substrate is formed, or is subsequently patterned by lithography etching, or formed by laser or plasma etching. The through holes are formed simultaneously with the ceramic substrate, or by patterning by lithography, or by laser or plasma etching. A manufacturing method of a high-power light-emitting diode package structure, comprising: a metal plating step of plating a metal layer on at least one of an upper surface and a lower surface of a ceramic substrate having at least one groove; a step of patterning the metal layer to form at least one wiring metal layer and a reflective metal layer, the wiring metal layer being formed on at least one of the upper surface and the lower surface of the ceramic substrate, and the reflective metal layer Forming on the sidewall of the at least one recess; a bonding step of connecting at least one light emitting diode to the at least one recess of the ceramic substrate by using at least one die-solid layer; a light-emitting diode is connected to the circuit metal layer by at least one wire; and a sealing step of coating the reflective metal layer, the at least one crystal grain-forming layer, and the at least one light-emitting diode with an encapsulant, And the at least one wire, wherein the power of the at least one light emitting diode is greater than 1W. The method of claim 9, wherein the ceramic substrate further comprises a plurality of via holes, and the via holes are filled with metal during the metal plating step, such that when the wiring metal layer is formed in the ceramic The lower surface of the substrate is connected to the reflective metal layer or the at least one crystal grain-forming layer through the metal in the via holes. The method of claim 10, wherein the patterning step further forms the metal layer into a connecting metal layer, the connecting metal layer is connected to the at least one wire, and the connecting metal layer and the through holes The metal is connected such that the light emitting diode is electrically connected to the wiring metal layer through the connecting metal layer, the metal in the through holes, and the wiring metal layer formed on the lower surface of the ceramic substrate, and the connecting metal layer It is covered by the encapsulant. The method of claim 9, wherein the metal plating step is at least one of electroplating, electroless plating, evaporation, and sputtering, and the patterning step is to use the metal layer as a photoresist. Patterning by coating, developing, etching, or photoresist removal, or patterning by laser removal or plasma etching. The grooves are simultaneously formed when the ceramic substrate is fabricated, or subsequently lithographically etched. Patterning, or by laser, plasma etching. The method of claim 10, wherein the through holes are formed simultaneously with the ceramic substrate, or are subsequently patterned by lithography etching, or by laser or plasma etching. To form. The method of claim 9, wherein the at least one crystal solid layer is a conductive heat dissipating adhesive, and the at least one light emitting diode is adhesively bonded to the at least one of the ceramic substrate. In the groove, the conductive heat-dissipating adhesive is at least one of gold glue, silver glue, tin glue, carbon glue and graphite glue. The method of claim 9, wherein the at least one crystal solid layer is a metal eutectic layer, and the at least one light emitting diode is connected to the ceramic substrate in a metal eutectic manner. In a recess, the metal eutectic layer is at least one of copper, aluminum, molybdenum, chromium, gold, silver, nickel, and tungsten. The method of claim 9, wherein the ceramic substrate is made of at least one of tantalum nitride, aluminum nitride, boron nitride, and tantalum carbide, the wiring metal layer, the reflective metal layer And the metal filled in the through holes is at least one of copper, aluminum, molybdenum, chromium, gold, silver, nickel, and tungsten, and the encapsulant is at least one of epoxy resin and cerium oxide. .