CN202487662U

CN202487662U - Light-emitting diode (LED) package structure capable of improving light extraction efficiency

Info

Publication number: CN202487662U
Application number: CN2011205742033U
Authority: CN
Inventors: 王冬雷; 庄灿阳; 黄瑞志
Original assignee: Elec Tech International Co Ltd
Current assignee: Dalian Dehao Photoelectric Technology Co., Ltd.
Priority date: 2011-12-30
Filing date: 2011-12-30
Publication date: 2012-10-10
Anticipated expiration: 2021-12-30

Abstract

The utility model provides a light-emitting diode (LED) package structure capable of improving light extraction efficiency, which comprises a package substrate, an LED chip arranged on the package substrate and package adhesives covering the package substrate and the LED chip, wherein a domed lens is further arranged between the LED chip and the package adhesives, and the roughness of the spherical surface of the lens is less than 100 nanometers. The LED package structure capable of improving light extraction efficiency is simple in structure, the domed lens is arranged on the LED chip, the light emitted by the LED chip is refracted through the sphere surface of the lens, and therefore the problem of total reflection of light is resolved, and the light extraction efficiency of the LED chip is improved. Meanwhile, due to the fact that the refractive index of the LED chip, the lens and the package adhesives is lowered gradually and close to the refractive index of the air, the problem of out-light surface reflection of the light is further resolved, and the light extraction efficiency is improved. In addition, the lens is arranged on the LED chip, feasibility of the process is high, large-scale mass production is facilitated, and practicability is strong.

Description

Improve and get the LED encapsulating structure of light rate

Technical field

The utility model relates to LED encapsulation technology field, and the LED encapsulating structure of light rate is got in a kind of specifically raising.

Background technology

Because LED wafer refractive index ratio is higher; Luminous material layer GaN (gallium nitride; Third generation semi-conducting material) refractive index is 2.3, and the sapphire refractive index of substrate material layer is 1.8, if the light that the LED wafer sends directly gets into air (refractive index of air is 1.0); Light can produce serious total reflection going out optical interface, makes most of light reflected back wafer inner.

At present, industry generally is to adopt epoxy resin or silica gel with the LED wafer package, gets optical efficiency with lifting; See also Fig. 1; Be the sketch map of the LED encapsulating structure in the known technology, led chip 10, its end face are provided with a phosphor powder layer 11; The bottom surface is arranged on the base plate for packaging 12; Packaging plastic 13 through a hemisphere directly encapsulates (packaging plastic generally adopts epoxy resin or silica gel) then, and generally between 1.4～1.6, still there is the light efficiency loss of larger proportion in the inner light of LED wafer for the silica gel of encapsulation and the refractive index of epoxy resin.Simultaneously, the shape of wafer has also determined the optical efficiency of getting of LED wafer, and as wafer being made the problem that hemisphere can overcome the total reflection of LED wafer fully, still, it is very high that wafer is directly done the hemisphere cost, and technological feasibility is poor.

Existing LED wafer mainly contains SiC (carborundum) substrate and two kinds of structures of Sapphire Substrate, and SiC is the exclusive technology of U.S. CREE company, and SiC material refractive index is about 2.8, has good bonding performance with silicon materials (refractive index about 3.0).Cree company adopts SiC and silicon chip applying, again silicon chip is carried out the wafer that the mode of corrosion processing obtains, and its surface is convex structure.But; Because widely different (the silica gel refractive index 1.4～1.5 of the refractive index of SiC or silicon materials and encapsulation silica gel; SiC and silicon materials refractive index are respectively 2.9 and 3.0), cause light to take out the surface texture that efficient relies on this silicon chip very much, and adopt etching process; The surface of silicon chip is difficult to form optical mirror plane, so the lifting of wafer light taking-up efficient and not obvious.Adopt Sapphire Substrate, its difficulty of processing is quite high, and Sapphire Substrate in the market is main with the rectangle wafer still, and Shang Weiyou is processed into the report of hemisphere or convex.

The utility model content

To the deficiency and the defective of above prior art, the purpose of the utility model is the LED encapsulating structure that provides a kind of raising to get the light rate.

The purpose of the utility model realizes through adopting following technical scheme:

The LED encapsulating structure of light rate is got in a kind of raising; Comprise base plate for packaging, be located at the led chip on this base plate for packaging and be covered in base plate for packaging and led chip on packaging plastic; Also be provided with a hemispherical lens between said led chip and the packaging plastic, the roughness of this lens spherical surface is less than 100nm.

As the optimal technical scheme of the utility model, the bottom surface of said lens covers the surface that said led chip combines with said lens at least fully.

As the optimal technical scheme of the utility model, the centre of sphere of said lens is positioned on the vertical center line on the surface that led chip combines with said lens.

As the optimal technical scheme of the utility model, be packaged with the polylith led chip on the said base plate for packaging.

As the optimal technical scheme of the utility model, said polylith led chip is equally spaced evenly distributed on this base plate for packaging with array way.

As the optimal technical scheme of the utility model, a phosphor powder layer is adhered in said lens bottom surface.

As the optimal technical scheme of the utility model, the refractive index of said lens is between 1.6 to 2.3.

As the optimal technical scheme of the utility model, said lens are group of the lanthanides glass lens or titanate glass lens.

As the optimal technical scheme of the utility model, said packaging plastic also forms hemisphere on said lens.

As the optimal technical scheme of the utility model, said packaging plastic is epoxy resin or silica gel.

Compared with prior art, the utility model is simple in structure, and hemispherical lens is set on the led chip, after the refraction at spherical surface of the rays pass through lens that led chip sends, can overcome the problem of light total reflection, has improved the efficient that LED wafer light takes out; Simultaneously, because the refractive index of led chip, lens and packaging plastic reduces the problem that has further solved light bright dipping boundary reflection near the refractive index of air gradually, improved and got optical efficiency.In addition, lens are set on led chip, its technological feasibility is high, is convenient to large-scale batch process, has stronger practicality.

Description of drawings

Fig. 1 is the sketch map of the LED encapsulating structure in the known technology.

Fig. 2 improves the sketch map of the LED encapsulating structure of getting the light rate for the utility model.

Fig. 3 improves the enlarged diagram of lens in the LED encapsulating structure of getting the light rate for the utility model.

Fig. 4 gets the structural representation of encapsulation polylith led chip on the base plate for packaging of LED encapsulating structure of light rate for the utility model improves.

Embodiment

Below in conjunction with accompanying drawing and specific embodiment the utility model is described further:

See also Fig. 2 and Fig. 3, be respectively the utility model and improve the sketch map of the LED encapsulating structure of getting the light rate and the enlarged diagram of lens.

The LED encapsulating structure of light rate is got in this raising, comprises base plate for packaging 101, is located at the led chip 102 on this base plate for packaging 101, on this led chip 102, is provided with lens 104, and these lens are hemisphere, and the roughness of its spherical surface is less than 100nm; The centre of sphere of said lens 104 is positioned on the vertical center line on the surface that led chip 102 combines with said lens 104; The bottom surface of said lens 104 covers the surface that said led chip 102 combines with said lens 104 at least fully, to reduce the light efficiency loss of led chip 102.These lens and led chip generally use high refractive index transparent glue (like epoxy resin or silica gel) to be bonded in one, also can use the mode of bonding to process, for example, and bonding modes such as chemical bonding, surface active bonding, diffusion welding (DW) bonding.Outside said base plate for packaging, led chip and lens, also be coated with one deck packaging plastic; Said packaging plastic 103 also forms hemisphere on said lens 104; This packaging plastic 103 can adopt epoxy resin or silica gel.

Said lens 104 can adopt group of the lanthanides glass lens or titanate glass lens, and its refractive index is near the refractive index of said led chip 102; Said lens 104 also can be the optical lens of other refractive indexes between 1.6 to 2.3.

Adopt this kind structure, led chip 102 end faces are covered by hemispherical lens 104, and the light that led chip 102 sends can overcome the problem of light total reflection through the refraction at spherical surface of lens 104; Simultaneously, because the refractive index of led chip 102, lens 104 and packaging plastic 103 reduces the problem that has further solved light bright dipping boundary reflection near the refractive index of air gradually, improved and got optical efficiency.In addition, lens 104 are set on led chip 102, its technological feasibility is high, is convenient to large-scale batch process, has stronger practicality.

A white light conversion layer 105 is also adhered in the bottom surface of said lens 104, and in the industry cycle, this white light conversion layer 105 is generally phosphor powder layer.This phosphor powder layer can be provided with through three kinds of processing modes: the first makes the bottom of lens 104 be in molten condition through laser radiation lens 104, and evenly be coated in lens 104 bottoms, subsequently cooling curing with fluorescent material this moment; Its two, heating fluorescent material is pressed in lens 104 both is combined; Its three, fluorescent material is tiled in presses the whole heating of lens 104 on the glass carrier both combined.

In the present embodiment, said led chip 102 is single encapsulation, promptly encapsulates a led chip 102 on a base plate for packaging 101; In the use,, strengthen the brightness of LED light for increasing the power of LED light fixture; Encapsulation polylith led chip 102 that also can be integrated on base plate for packaging 101 sees also Fig. 4, is the structural representation of encapsulation polylith led chip on the base plate for packaging; For making light even; This polylith led chip 102 is equally spaced evenly distributed on this base plate for packaging 101 with the mode of array, and its encapsulating structure is just no longer given unnecessary details at this with above-mentioned consistent.

The preferred embodiment that the above is merely the utility model is not the practical range that is used for limiting the utility model; As form in lens 104 bottoms one with the consistent groove of led chip 102 shapes, when lens 104 were arranged on the chip, said led chip 102 was contained in this groove, can improve the extraction efficiency of light etc.; Be that every equivalence of doing according to the utility model changes and modification, all drop in the protection range of the utility model.

Claims

1. the LED encapsulating structure of light rate is got in a raising; Comprise base plate for packaging, be located at the led chip on this base plate for packaging and be covered in base plate for packaging and led chip on packaging plastic; It is characterized in that: also be provided with a hemispherical lens between said led chip and the packaging plastic, the roughness of this lens spherical surface is less than 100nm.

2. the LED encapsulating structure of light rate is got in raising according to claim 1, it is characterized in that: the bottom surface of said lens covers the surface that said led chip combines with said lens at least fully.

3. the LED encapsulating structure of light rate is got in raising according to claim 2, it is characterized in that: the centre of sphere of said lens is positioned on the vertical center line on the surface that led chip combines with said lens.

4. the LED encapsulating structure of light rate is got in raising according to claim 1, it is characterized in that: be packaged with the polylith led chip on the said base plate for packaging.

5. the LED encapsulating structure of light rate is got in raising according to claim 4, it is characterized in that: said polylith led chip is equally spaced evenly distributed on this base plate for packaging with array way.

6. get the LED encapsulating structure of light rate according to claim 1 or 2 or 3 or 4 or 5 described raisings, it is characterized in that: a phosphor powder layer is adhered in said lens bottom surface.

7. get the LED encapsulating structure of light rate according to claim 1 or 2 or 3 or 4 or 5 described raisings, it is characterized in that: the refractive index of said lens is between 1.6 to 2.3.

8. the LED encapsulating structure of light rate is got in raising according to claim 7, it is characterized in that: said lens are group of the lanthanides glass lens or titanate glass lens.

9. the LED encapsulating structure of light rate is got in raising according to claim 1, it is characterized in that: said packaging plastic also forms hemisphere on said lens.

10. get the LED encapsulating structure of light rate according to claim 1 or 9 described raisings, it is characterized in that: said packaging plastic is epoxy resin or silica gel.