LED Flip-Chip Structure

Abstract

An LED flip-chip structure is provided, wherein a silica gel, a fluorescent glue, a lens, an anti-reflection film and a packaging adhesive layer is sequentially arranged on the LED chip. The silica gel and fluorescent glue are sequentially filled within an insulating reflective cup, outside which a metal reflective cup and a light absorption layer is sequentially provided. The packaging adhesive layer is filled between the reflective cup and the lens. A sapphire substrate is pretreated to form an inverted T-shaped structure, on which a layer of epitaxial wafer of ceramic film is grown, and then a layer of high temperature resistant conductive film is grown on upper surfaces of grooves at both sides. A protrusion of the inverted T-shaped structure is uniformly coated with a thermally conductive adhesive with a certain thickness.

Claims

1. An LED flip-chip structure, comprising: an LED chip; a plurality of conductive films; a ceramic film for heat dissipation arranged below the plurality of conductive films; a sapphire substrate arranged below the ceramic film, the sapphire substrate is raised upward at a middle portion to form a protrusion; a plurality of bonding pads, each of the plurality of bonding pads is connected at a bottom thereof to one of the plurality of conductive films and is connected at a top thereof to the LED chip; an insulating reflective cup arranged on and fixed connected to the plurality of conductive films; a silica gel layer, a fluorescent glue; a lens; an anti-reflection film; and a packaging adhesive layer, wherein both of the LED chip and the plurality of bonding pads are located at a bottom of the insulating reflective cup; the silica gel layer, the fluorescent glue, the lens, the anti-reflection film and the packaging adhesive layer are all arranged within the insulating reflective cup and sequentially cover the LED chip from inside out, and both of the silica gel layer, the fluorescent glue cover at least five surfaces of the LED chip.

2. The LED flip-chip structure according to claim 1, wherein the protrusion is formed by the sapphire substrate, and an upper surface of the sapphire substrate at the protrusion abuts against a bottom of the LED chip.

3. The LED flip-chip structure according to claim 1, wherein the protrusion is formed by the sapphire substrate and the ceramic film, and an upper surface of the ceramic film at the protrusion abuts against a bottom of the LED chip.

4. The LED flip-chip structure according to claim 1, wherein the protrusion is formed by the sapphire substrate and a thermally conductive adhesive layer, and an upper surface of the thermally conductive adhesive layer at the protrusion abuts against a bottom of the LED chip.

5. The LED flip-chip structure according to claim 1, wherein the protrusion is formed by the sapphire substrate, the ceramic film and a thermally conductive adhesive layer sequentially, and an upper surface of the thermally conductive adhesive layer at the protrusion abuts against a bottom of the LED chip.

6. The LED flip-chip structure according to claim 1, wherein the lens is internally mixed or externally coated with phosphor for enhancing light transmission.

7. The LED flip-chip structure according to claim 1, wherein a metal reflective cup is provided outside the insulating reflective cup for enhancing light reflection and reducing light transmission.

8. The LED flip-chip structure according to claim 7, wherein a light absorption layer is provided outside the metal reflective cup to prevent light from scattering to outside.

9. The LED flip-chip structure according to claim 1, wherein an angle between an inner circumferential surface and a bottom surface of the insulating reflective cup is between 45 and 90.

10. The LED flip-chip structure according to claim 9, wherein the insulating reflective cup is made of a transparent insulating material with a nonuniform density distribution, and density and thickness of the insulating reflective cup are both inversely proportional to a distance between the insulating reflective cup and the LED chip.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG. 1 is a schematic diagram of solution 1 of the LED flip-chip structure provided by the present invention.

[0035] FIG. 2 is a schematic diagram of solution 2 of the LED flip-chip structure provided by the present invention.

[0036] FIG. 3 is a schematic diagram of solution 3 of the LED flip-chip structure provided by the present invention.

[0037] FIG. 4 is a schematic diagram of solution 4 of the LED flip-chip structure provided by the present invention.

[0038] FIG. 5 is a schematic diagram of an overall structure obtained by arrangement and combination of a plurality of individual LED flip-chip structures provided by the present invention.

[0039] FIG. 6 is a schematic diagram of an LED flip-chip structure in the prior art with five-side light emission.

[0040] FIG. 7 is a schematic diagram of an LED flip chip in the prior art using a molding package structure.

[0041] FIG. 8 is a schematic diagram of an angle relation between two insulating reflective cups of the LED flip-chip structure provided by the present invention.

[0042] Description of the labels in the above drawings are as follows:

[0043] 1packaging glue layer, 2insulating reflective cup, 3light absorption layer, 4fluorescent glue, 5conductive film, 5asubstrate, 6LED chip, 7bonding pad, 8ceramic film, 9lens, 10anti-reflection film, 11metal reflective cup, 12silica gel layer, 13thermally conductive glue layer, 14sapphire substrate, 15heat dissipation hole.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] To better clarify the purposes, technical solutions and advantages of the present invention, the present invention will be further explained in conjunction with the accompanying drawings and the embodiments.

Embodiment 1

[0045] As shown in FIG. 1, the present invention discloses an LED flip-chip structure comprising an LED chip 6, an insulating reflective cup 2, a fluorescent glue 4, a packaging glue layer 1, conductive films 5, bonding pads 7, a lens 9, an anti-reflection film 10 for improving light transmittance and reducing light reflection, a silica gel layer 12, and a sapphire substrate 14. Insulation is respectively formed between the conductive films 5, and between the bonding pads 7. The insulating reflective cup 2 is arranged on and fixedly connected with the conductive films 5, for reflecting light emitted from the LED chip 6 and fixing the LED encapsulation. Below the conductive films 5 a ceramic film 8 is further provided for heat dissipation. The sapphire-substrate ceramic film 8 protrudes upwardly between the two conductive films 5 to form a protrusion that isolates the conductive films 5, increasing contact surface between the conductive film 5 and the bonding pad 7, and offering effective heat dissipation to the LED chip 6. The LED chip 6 and the bonding pads 7 are located at a bottom of the insulating reflective cup 2. Each of the bonding pads 7 is electrically connected at a bottom of the pad to the corresponding conductive film 5 through an electrode plated therebetween, and is electrically connected at a top of the pad to the LED chip, then a loop with outside circuitry is formed through gold wires. The silica gel layer 12, the fluorescent glue 4, the lens 9, the anti-reflection film 10 and the packaging adhesive layer 1 are all arranged within the insulating reflective cup 2 and sequentially cover the LED chip 6 from inside out. As a preferred embodiment of the present invention, the silica gel layer 12 and the fluorescent glue 4 are applied to a plurality of faces of the LED chip 6 (excluding a small portion of bottom surface) to form a multi-sided encapsulation of the chip, so that the packaged component emits light from several surfaces, apparently improving the luminous efficiency of the LED component.

[0046] Specifically, in conjunction with FIGS. 1, 2, 3, and 4, composition and height of the protrusion in the present invention include the following four solutions:

[0047] Solution 1: The protrusion is formed only by the sapphire substrate 14, a middle portion of which is raised up and extends all the way to and abuts against the bottom of the LED chip 6 to accelerate heat dissipation.

[0048] Solution 2: The protrusion is formed by the sapphire substrate 14 and the ceramic film 8, wherein the ceramic film 8 is grown on a surface of the sapphire substrate 14, a middle portion of which is raised up and extends all the way to the bottom of the LED chip 6, to cause an upper surface of the ceramic film 8 abuts against the bottom of the LED chip 6 to accelerate heat dissipation thereof.

[0049] Solution 3: The protrusion is formed by the sapphire substrate 14 and a thermally conductive adhesive layer 13. A middle portion of the sapphire substrate 14 is raised up to a certain height without touching the LED chip 6. A gap between the protrusion and the LED chip 6 is filled with the thermally conductive adhesive layer 13 such that heat generated by the LED chip 6 is quickly dissipated by the thermally conductive glue layer 13 and the sapphire substrate 14.

[0050] Solution 4: The protrusion is formed by the sapphire substrate 14, the ceramic film 8 and a thermally conductive adhesive layer 13. The ceramic film 8 is grown on a surface of the sapphire substrate 14, and a middle portion of the sapphire substrate 14 is raised up to a height, but the upper surface of the ceramic film 8 does not contact with the LED chip 6. A gap between the ceramic film 8 and the LED chip 6 is filled with the thermally conductive adhesive layer 13 such that heat generated by the LED chip 6 is quickly dissipated by the thermally conductive adhesive layer 13, the ceramic film 8 and the sapphire substrate 14.

[0051] As a preferred embodiment of the present invention, in order to improve the light transmittance, the silica gel layer 12 is made of a highly refractive transparent silica gel, which is located between the LED chip 6 and the fluorescent glue 4, thereby effectively reducing the photon loss at an interface thereof and improving the light output efficiency. The transparent silica gel layer 12 can also provide mechanical protection and stress relief for the chip, and as a light-guiding structure, the silica gel layer 12 also has the advantages of high light transmittance, high refractive index, good thermal stability, good fluidity, easy spraying, etc. Moreover, the transparent silica gel layer 12 has low moisture absorption, low stress, anti-aging and other characteristics, which can significantly improve the reliability of LED package. In practice, the LED chip 6 is placed in a transparent silica gel solution for coating treatment through electric heating; after a period of time, the LED chip 6 is taken out and then, once the uniformly covered silica gel cools and curdles, put into a vacuum oven for further drying and solidification treatment for 1 h, so that multiple surfaces of the LED chip 6 are coated with a silica gel layer 12. The above coating process needs to be repeated 4-5 times in order to obtain a more uniform silica gel layer. Besides, a multi-surfaces silica gel package can be formed around the LED chip 6 through changing the mixed gel proportion, drying process and other processes, so as to emit light from several surfaces.

[0052] As a preferred embodiment of the present invention, in order to obtain a better light transmittance, phosphor can be internally mixed or externally coated on a surface of the lens 9 through electrophoretic deposition, sputter deposition coating, spin coating, etc., which will not only improve the uniformity of the phosphor, but also improve the package efficiency.

[0053] Further, in order to avoid the vignetting effect and improve the light quality, a metal reflective cup 11 for enhancing the reflection effect is provided outside the insulating reflective cup 2. A part of light emitted from the LED chip 6 is reflected by the insulating reflective cup 2, the other part penetrates through the insulating reflective cup 2 and is reflected again by the metal reflective cup 11, so that the light is more concentrated and will not scatter sideward. Further, the light saturation, the chromaticity coordinate, the color contrast, and the color rendering index of the light emitted from the LED chip 6 can be maintained, and a desired luminous effect can be obtained.

[0054] Further, although the metal reflective cup 11 can reflect the vast majority of the light, a small portion of the light can penetrate through the metal reflective cup 11. Thus in order to obtain better luminous quality, a light absorption layer 3 for avoiding light scattering is provided outside the metal reflective cup 11, and all the light penetrating through the metal reflective cup 11 is absorbed by the light absorption layer 3, so as to avoid the vignetting effect.

[0055] Further, in order to improve the heat dissipation effect of the LED chip 6, the bottom of the LED chip 6 between the bonding pads 7 is filled with a thermally conductive adhesive layer 13 for heat dissipation. Specifically, the thermally conductive adhesive is completely filled between the protrusion formed by the sapphire-substrate ceramic film 8 and the bottom of the LED chip 6 to form a thermally conductive adhesive layer 13. A portion of heat generated by the LED chip 6 is dissipated quickly through the bonding pad 7, the conductive film 5 and the ceramic film 8, and the other portion of heat can be quickly dissipated through the thermally conductive adhesive layer 13 and the ceramic film 8, enhancing the heat dissipation effect; the bonding pad 7, the conductive film 5, the thermally conductive adhesive layer 13 and the ceramic film 8 contact with each other for heat transfer, improving the heat dissipation efficiency. In addition, in order to ensure the heat dissipation effect, it is required to strictly control that sum of the height of the protrusion in the ceramic film 8 inverted T-shaped structure and the thickness of the thermally conductive adhesive layer 13 is equal to sum of the height of the bonding pad 7 and the thickness of the conductive film 5, that is, the thermally conductive adhesive layer 13 is completely in contact with, at a top thereof, the bottom of the LED chip 6, and completely abuts against, at a bottom thereof, the protrusion of the ceramic film 8.

[0056] As a preferred embodiment of the present invention, the conductive film 5 is made of a high temperature resistant film, which can be obtained by magnetron sputtering, chemical vapor deposition, hydride vapor phase epitaxy, photolithography and other methods. The specific method is as follows: a layer of epitaxial wafer of ceramic film 8 is grown on upper surfaces of grooves at both sides of the inverted T-shaped sapphire substrate. Similarly, a layer of high temperature resistant conductive film 5 is further grown on an upper surface of the sapphire-substrate ceramic film 8. Specifically, the selected sputtering target material is ZnO doped with an appropriate amount of Mg and Ga (ZnO:Mg:Ga). The results are analyzed by means of X-ray diffraction, UV/VIS spectrophotometer and scanning electron microscope. The high temperature resistant conductive film 5 prepared by this method has a high light transmittance, a low resistivity, a superior conductivity and other advantages. As shown in FIG. 5, an individual packaged component is cut in a circumferential arc direction (small circles in the figure) to remove an excess portion of the sapphire-substrate ceramic film 8 to form a complete component structure. Considering the overall effect, when arranging and assembling a plurality of individual LED components, each bottom thereof is provided on the ceramic film 8 and the sapphire substrate 14 for heat dissipation, and a number of heat dissipation holes with varied sizes are provided in the sapphire substrate 14 to get better heat dissipation effect.

[0057] As a preferred embodiment of the present invention, in order to achieve a better heat dissipation effect, prevent the chip from overheating and prolong the LED service life, the ceramic film 8 with a sapphire substrate is adopted. Specifically, the processing steps of the sapphire-substrate ceramic film 8 are as follows: pretreatments such as photolithography, hollowed-out process are performed on the sapphire substrate 14 in accordance with thickness and height ratios between the components in the structural diagram to form an inverted T-shaped structure, and then a layer of ceramic film 8 is grown on upper surfaces of grooves of the inverted T-shaped sapphire-substrate structure, after that another layer of high temperature resistant conductive film 5 is grown on the upper surface of each groove of the inverted T-shaped ceramic film 8 according to the proportions of the various components in the structural diagram. A circuit can be prepared on the ceramic film 8 by magnetron sputtering and photolithography, and sputtering coating, electro-/electrochemical deposition or photolithography hollowed-out can be used to change the circuit thickness, so as to offer products with high line accuracy, high flatness and other advantages. In actual packaging, sorting equipment is used to arrange flip chips according to a fixed periodic sequence. The conductor chip pads 7 are matched with electrode areas of the chips. Each of conductor chip pads 7 is directly and closely abutted against the high temperature resistant conductive film 5 through a plated electrode to allow the bonding pad 7 to be electrically connected to the conductive film 5.

[0058] As a preferred embodiment of the present invention, the fluorescent glue 4 is formed by mixing phosphor and silica gel. In order to obtain a better light-transmitting effect, on one hand, the phosphor needs to be subjected to multiple grinding and purification, and weight ratio of the mixed phosphor and silica gel is 10:90, on the other hand, different package processes are used to arrange two layers of phosphor at an interval.

[0059] As a preferred embodiment of the present invention, in order to improve the reflection effect of the insulating reflective cup 2 and the fixation effect at the time of packaging, the individual LED package structure is symmetrical with respect to an central axis, so half cross-sections of the insulating reflective cup 2 (a half cross-section is a cross-section intercepted by a plane formed by the center axis and any radius from the insulating reflective cup 2) are designed as right triangles, and the larger angle in the right triangle meets (45,90) to always guarantee 90.

[0060] Further, the insulating reflective cup 2 is made of a transparent insulating material with nonuniform density distribution, and the density p and the thickness d of the insulating reflective cup 2 are inversely proportional to a distance r between the insulating reflective cup 2 and the LED chip 6, that is, the density and thickness of the insulating reflective cup 2 gradually decrease from inside out.

[0061] As a preferred embodiment of the present invention, a too thick silica gel layer 12 will affect the light-emitting efficiency of the LED chip 6, increase the light loss, and cause serious problems of self-heating and difficult heat dissipation of the LED chip 6. While a too thin silica gel layer 12 will also affect the light-emitting efficiency of the LED chip 6. Therefore, the thickness of the silica gel layer 12 is designed to be 0.05 mm in the present invention.

[0062] As a preferred embodiment of the present invention, the high temperature resistant conductive film 5 and the sapphire-substrate ceramic film 8 collectively replace the conventional heat-dissipating aluminum substrate. Without limitation of the aluminum substrate, size of the packaged component is significantly reduced to be very close to the chip area, and the packaged component has the advantages of precise manufacturing, high integration, light weight, etc., truly achieving a chip scale integrated LED package.

[0063] As a preferred embodiment of the present invention, the thermally conductive adhesive layer 13 may be further replaced by the ceramic film 8, i.e., the protrusion height of the ceramic film continues to increase and the increased height is equal to the thickness of the thermally conductive adhesive layer.

[0064] The operating process and principle of the invention are as follows: the majority of light emitted from the LED chip 6 is concentrated in the vertical direction and emitted parallelly after passing through the silica gel layer 12, the fluorescent glue 4, the lens 9, the anti-reflection film 10 and the packaging adhesive layer 1, and the light emitted sideward can be reflected by the insulating reflective cup 2. A small portion of the light refracted by the insulating reflective cup 2 reaches the metal reflective cup 11, and is reflected by the metal reflective cup 11. A very small amount of light can even penetrate through the metal reflective cup 11, but a light absorption layer 3 is provided behind the metal reflective cup 11, which can completely absorb the light penetrating through the metal reflective cup 11, thus avoiding the vignetting effect. Each bonding pads 7 at the bottom of the LED chip 6 is electrically connected to a conductive film 5 through a plated electrode. A ceramic film 8 is provided at a bottom of each conductive film 5 for heat dissipation, and a thermally conductive adhesive layer 13 is filled between the bottom of the LED chip 6 and the ceramic film 8, so heat generated by the LED chip 6 can be quickly dissipated through the bonding pad 7, the conductive film 5 and the ceramic film 8, or through the thermally conductive adhesive layer 13 and the ceramic film 8. The bonding pad 7, the conductive film 5, the thermally conductive packaging adhesive layer 1 and the ceramic film 8 contact with each other, improving the heat dissipation efficiency. The invention has advantages of high light transmittance, good heat dissipation effect and small package size.

Embodiment 2

[0065] As shown in FIG. 1, an LED flip-chip structure, including an LED chip 6, a lens 9 internally mixed or externally coated with phosphor, a fluorescent glue 4, an insulating reflective cup 2, a metal reflective cup 11, an anti-reflection film 10, a packaging adhesive layer 1, a transparent silica gel layer 12, bonding pads 7, high temperature resistant conductive films 5, a light absorption layer 3, a ceramic film 8 with a sapphire substrate, and a thermally conductive adhesive layer 13. The LED chip 6 with a flip-chip structure is packaged within the fluorescent glue 4. Surfaces of the LED chip is coated with a transparent silica gel layer 12 having a high refractive index. Two conductor bonding pads 7 at a front side of the LED chip 6 are abutted against and electrically connected to the high temperature resistant conductive films 5 through plated electrodes respectively. The lens 9 internally mixed or externally coated with phosphor is provided on an upper surface of the fluorescent glue 4. The anti-reflection film 10 for enhancing the light transmittance is provided on an upper surface of the lens 9. An uniform layer of the packaging adhesive layer 1 is sprayed on an upper surface of the anti-reflection film 10. The fluorescent glue 4, the lens 9, the anti-reflection film 10, and the packaging glue layer 1 are filled within the insulating reflective cup 2, the metal reflective cup 11 is provided outside the insulating reflective cup 2, and the light absorption layer 3 is provided outside the metal reflective cup 11.

[0066] FIG. 6 shows an LED flip-chip structure in the prior art with five-sided light emission, including an LED chip 6. Chip bonding pads 7 are provided at a front side of the LED chip 6, and five faces of the LED chip 6 are coated with a uniformly mixed fluorescent glue 4. A packaging adhesive layer 1 is provided outside of the fluorescent glue 4. FIG. 7 shows a flip chip in the prior art using molding package. Specifically, LED chips 6 abut directly against substrate 5a through conductor bonding pads, respectively, and are covered by a fluorescent glue 4. In the above LED package structure, the distance between the phosphor and the chip is close, so heat released by the chip will be easily absorbed by the phosphor (stronger thermal radiation). However, the small size of the LED prohibits effective heat exchange with the outside world, and the packaged components will be damaged due to bad heat dissipation, thus the stability and service life will be affected.

[0067] The high temperature resistant conductive film 5 can be obtained by magnetron sputtering, chemical vapor deposition, hydride vapor phase epitaxy, photolithography and other methods. In the magnetron sputtering experiment, a layer of epitaxial wafer of ceramic film 8 is grown on the upper surface of the inverted T-shaped sapphire substrate. Similarly, a layer of high temperature resistant conductive film 5 is further grown on the upper surface of grooves at both sides of the sapphire-substrate ceramic film 8. Specifically, the selected sputtering target material is ZnO doped with an appropriate amount of Mg and Ga (ZnO:Mg:Ga). Experiment results are analyzed by means of X-ray diffraction, UV/VIS spectrophotometer and scanning electron microscope. The high temperature resistant conductive film 5 prepared by this method has a high light transmittance, a low resistivity, a superior conductivity and other advantages. As shown in FIG. 5, the sapphire-substrate ceramic film 8 is cut in the circumferential arc direction to remove the excess portion of the sapphire-substrate ceramic film to form a separate component structure.

[0068] In order to obtain a better light transmittance, the lens 9 is internally mixed or externally coated with phosphor, which improves the uniformity of the phosphor and the emitted light, and improves the packaging efficiency. The mixed phosphor in the packaged adhesive layer is subjected to multiple grinding and purification, with the weight ratio of the phosphor and silica gel in the fluorescent glue controlled to be 10:90. An anti-reflection film for enhancing the light transmittance is further provided on the upper surface of the lens 9. A highly refractive transparent silica gel layer 12 is uniformly coated on surfaces of the LED chip 6, which is located between the LED chip 6 and the fluorescent glue 4, thereby effectively reducing the photon loss at an interface and improving the light transmittance efficiency. In addition, the transparent silica gel layer 12 can also provide mechanical protection and stress relief for the chip, and as a light-guiding structure, the silica gel layer also has the advantages of high transmittance, high refractive index, good thermal stability, good fluidity, easy spraying, etc. Moreover, the transparent silica gel layer 12 has low moisture absorption, low stress, anti-aging and other characteristics, which can improve the reliability of LED package.

[0069] In order to achieve a better heat dissipation effect, prevent the chip from overheating and prolong the LED service life, a circuit can be prepared on the sapphire-substrate ceramic film 8 by magnetron sputtering and photolithography, and sputtering coating, electro-/electrochemical deposition or photolithography hollowed-out can be used to change the circuit thickness, so as to offer products with high line accuracy, high flatness and other advantages. Sorting equipment is used to arrange flip chips 6 according to a fixed periodic sequence. The conductor chip pads 7 are matched with electrode areas of the chips. The conductor chip pads 7 are directly and closely abutted against the high temperature resistant conductive films 5 of the grooves at both sides of the inverted T-shaped structure, respectively, and the thermally conductive adhesive layer 13 is completely filled between and abutted against the two bonding pads at the front side of the flip chip, strictly ensuring that the protrusion height of the inverted T-shaped structure is equal to the sum of the thicknesses of the chip pad, the plated electrode and the high temperature resistant carrier film.

[0070] In order to avoid the vignetting effect and increase the light quality, a metal reflective cup 11 is provided outside the insulating reflective cup 2, and a light absorption layer 3 is provided outside the metal reflection cup 11. The insulating reflective cup 2 is made of an insulating transparent material with nonuniform density distribution, and the density and thickness of the insulating reflective cup are designed to be inversely proportional to a distance between the insulating reflective cup and the chip; the larger angle in the right triangle meets (45,90) to always guarantee 90.

[0071] The LED chip 6 is placed in a transparent silica gel solution for coating treatment through electric heating, and taken out after a period of time. The above operation is repeated 3-4 times, until the silica gel uniformly coated on the chip is cooled and curdled. Then the LED chip 6 is put into the vacuum oven for further drying and solidification treatment for 1 h, so that multiple surfaces of the LED chip 6 are coated with a silica gel layer 12. The coating process needs to be repeated 4-5 times in order to obtain a more uniform silica gel layer with a thickness of 0.05 mm. Besides, a multi-surfaces silica gel encapsulation around the LED chip may also be formed through changing the mixed gel proportion, drying process and other processes. Subsequently, the fluorescent glue 4 is uniformly sprayed on a plurality of surfaces of the LED chip 6 coated with the silica gel, so that the package component emits light from multiple surfaces. The operating principle of the invention is as follows.

[0072] The metal reflective cup 11 is provided outside the insulating reflective cup 2, and the light absorption layer 3 is provided outside the metal reflective cup 11. A small amount of light emitted from the LED chip 6 is refracted by the insulating reflective cup 2 to the metal reflective cup 11 by which the light may be reflected, and a very small amount of light that continues to penetrate through the metal reflective cup 11 can also be completely absorbed by the light absorption layer 3 without causing the vignetting effect outside. The anti-reflection film 10 is provided on outer surface of the lens 9 internally mixed or externally coated with the phosphor to reduce the reflection. Surfaces of the LED chip 6 are coated with the highly refractive transparent silica gel layer 12 that increases the light transmittance, thereby the light saturation, color rendering index, chromaticity coordinate and color contrast of the present invention can be maintained to overcome the current shortcomings.

[0073] The lens 9 internally mixed or externally coated with phosphor is provided on upper surface of the fluorescent glue 4, the phosphor is subjected to repeated grinding and purification, and the specific proportion of the phosphor in the fluorescent glue is under control. Surfaces of the LED chip 6 are uniformly coated with a highly refractive transparent silica gel layer 12, and the transparent silica gel and the fluorescent glue are uniformly coated on a plurality of surfaces of the LED through electric heating and plating, increasing the light-emitting area, enhancing the light output efficiency, and further improving the light quality.

[0074] The high temperature resistant conductive film 5 and the sapphire-substrate ceramic film 8 collectively replace some of the conventional heat-dissipating aluminum substrates in the prior art. Without limitation of the aluminum substrate, the size and weight of the packaged components are reduced, and a chip-level package can be realized. At the same time, the thermally conductive adhesive layer 13 may be filled between the two bonding pads 7 of the LED flip chip and the sapphire-substrate ceramic film 8, greatly improving the heat dissipation performance.

[0075] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited thereto. Any other changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principle of the present invention should be equivalent replacements, and are included within the scope of protection of the invention.