CN101173758A - Non-reflection high light extracting rate unit WLED power expanding type high power WLED light source - Google Patents

Abstract

The invention relates to a no-reflection high-efficient-luminescence unitary-WLED power-capacity-expansion high-power light source. A plurality of blue-light BLED chips are welded on a radiating base plate. The surfaces of the BLED chips are coated with silica gel phosphor powder, which forms white-light WLED illuminants. The high-light-transmittance and high-intensity industrial plastic PC is made into a thin isopachous hemisphere-shaped casing. The PC casing is filled with high-transparency silicon gel which has the same light transmittance as the PC, which forms a silica gel hemispherical lens. The silica gel lens is packaged above the phosphor powder along the centre to form the no-reflection and high-efficient-luminescence unitary WLED light source. A plurality of unitary WLED light sources are assembled to a high-power WLED light source by capacity expansion. The light source can be make into a street lamp, an emergency lighting lamp, a safety lighting lamp for mine roadway, a mine cap lamp, a safety lighting lamp for subway and airport, an indoor lighting lamp and other WLED lighting lamps. The invention has the advantages of scientifically reasonable structure, low production cost, good radiating property, low power consumption, high efficient luminescence, long service life and other advantages.

Description

Areflexia high light-emitting rate unit WLED power expanding type high power WLED light source

Technical field

Content of the present invention belongs to the technology of semiconductor illumination application field, relates to a kind of energy-efficient high-power WLED light source.

Background technology

So far in all kinds of electric equipments the power consumption maximum be lighting apparatus, at present China's electric consumption on lighting amount accounts for about 20% of national gross generation, but adopts the semi-conductor lighting lamp (LED) of saves energy to make up the key factor of energy-efficient society beyond doubt.In recent years; startup along with national Green Lighting Project; the National Development and Reform Commission etc. are multidisciplinary to be organized in concert and has implemented to be intended to saves energy, protects environment, improves the activity of lighting quality, and semi-conductor lighting lamp becomes in " national Green Lighting Project " and explicitly calls for the major product of applying.

At present, because the power＜5w of single LED lamp, the requirement that does not still reach high-power illumination combines by series, parallel so the light source of the known LED illuminating lamp in high-power LED illumination field generally all adopts by many led chips less than 5w.Its basic packaging technology structure is as shown in Figure 1: welding blue-light-emitting chip (BLED chip) 2 on heat-radiating substrate 1; On BLED chip 2, coat silica gel matter fluorescent material 3; Planar package is protected silica gel 6 on fluorescent material 3 again.Though above-mentioned common high-power LED light source structure has solved the power expanding problem of LED illumination substantially, it still has the low deficiency that waits of light extraction efficiency, and its reason ascribes light channel structure analysis shown in Figure 2 to.

In LED lamp unit shown in Figure 2, when injecting silica gel 6 after by fluorescent material 3, the light beam that led chip 2 is sent forms 180 ° of light sources, and light is injected the space from silica gel 6 again.Light is to inject optically thinner medium by optically denser medium, is the medium of two kinds of different refractivities, and light can take place to off-normal direction refraction effect, when incidence angle can produce total reflection during greater than critical angle in silica gel.

Wherein: n ₁=n _S=1.53 n _SBe the silica gel refractive index

n ₂=n _A=1.0 n _ABe air refraction

Then get: θ by the Si Nieer formula _c=sin ^-1(n ₂/ n ₁)=sin ^-1° (1/1.53)=41.

Because due to the silica gel exiting surface plane, light beam is injected the air from silica gel, only work as angle of incidence of light degree θ＜θ in the light beam _cThe part of * 2=41 ° * 2=82 ° could reflect and export in the air space, and all the other very most of light form loss at total reflection in that silica gel is inner, can not output to air space.Inject the angle of silica gel with led chip institute light emitting source after by fluorescent material and compare for 180 °, rising angle is than only being: 82/180=0.46.Consider that the incidence angle of injecting the silica gel light beam is bigger, wherein the incident ray incidence angle is more than 120 ° the time, externally the influence of radiation light intensity a little less than, its light intensity contribution rate is by 30%, then injecting airborne light beam by silica gel will make light output efficiency be reduced to: E=82 °/[120 °+(60 ° * 30%)]=60%, that is: can make luminous flux loss about 40%; The total reflection energy of light in silica gel produces heat on the other hand, and the led chip temperature is raise, and can reduce luminous efficiency significantly when led chip is operated on the higher temperature, makes led chip produce decay of luminescence.

Summary of the invention

The objective of the invention is to overcome the deficiency that prior art exists, so provide a kind of scientific and reasonable for structure, cost of manufacture is low, perfect heat-dissipating, power consumption is low, optical efficiency is high, light decay reduces, the areflexia high light-emitting rate unit WLED power expanding type high power WLED light source of long service life.

The technical solution that adopts is so for achieving the above object: the areflexia high light-emitting rate unit WLED power expanding type high power WLED light source that is provided as shown in Figure 3 and Figure 4, the heat-radiating substrate 1 that it has a thickness is H1, being welded with a plurality of on heat-radiating substrate 1 is the BLED chip 2 of 2w by the determinant lamp battle array chip light emitting width of forming of arranging, be coated with one deck silica gel matter fluorescent material 3 above the chip 2 respectively at each, form white light WLED illuminator, the thickness of the thickness+fluorescent material 3 of chip 2 is h, each illuminator external application high transmission rate on heat-radiating substrate 1, it is that 0.2mm and light transmittance are the hemispherical shell 5 of slim uniform thickness of n1=1.40 that high strength industrial plastics PC is covered with a wall thickness respectively by the relational expression of H=R-0.577w-0.33h, H is the height of hemispherical shell 5 in the formula, R is the radius of hemispherical shell 5, R=H+H1, in hemispherical shell 5 and space that illuminator and substrate 1 surround, adopt and the high transparent silicon of the identical light transmittance of PC gel-filled in the PC shell formation silica gel packaged lens 4, form areflexia high light-emitting rate unit WLED light source thus, and then become high-power WLED light source by each unit WLED combination of light sources dilatation.

According to Si Nieer formula: n ₁Sin θ ₁=n ₂Sin θ ₂

Wherein, n ₁And n ₂Be respectively the refractive index of two media, θ ₁And θ ₂Be respectively incidence angle and refraction angle.

: incidence angle θ ₁In the time of=0 °: θ ₂=sin ^-1(0 °)=0 °

That is: when incident ray when a kind of medium of refractive index is vertically injected the another kind of dielectric surface of different refractivity, refraction and reflection do not take place in light, but vertical transmission enters.

In this WLED light source in each unit WLED work, in by the silica gel inner light beam light areflexia of angle of incidence of light θ＜120 °, do not have and reflect, vertically inject the space.

As shown in Figure 4, the relational expression of lens height H:

H＝R-H1

H1＝w ₁×tan(30°)

w ₁＝w-h×tan(30°)

H＝R-H1＝R-w ₁×tan(30°)＝R-[w-h×tan(30°)×tan(30°)]

＝R-0.577(w-0.577h)＝R-0.577w-0.33h

That is: satisfy when lens hemisphere height: during H=R-0.577w-0.33h by the silica gel inner light beam in the light of angle of incidence of light θ＜120 ° can areflexia, do not have and reflect, vertically inject the space.

In addition, the light by 120 °≤θ of angle of incidence of light in the silica gel inner light beam≤180 ° also can unreflectedly enter the space, as shown in Figure 4.

Know from above-mentioned derivation, form 180 ° of planar light sources when the light beam that led chip sent is injected silica gel after by fluorescent material, that is: beam angle is 180 ° when silica gel is injected into air interface.

∵θ ₁＝30°-θ ₃、θ ₃≥0°

∴θ ₁≤30°

Critical angle: θ _c=sin ^-1(n ₂/ n ₁)

Its medium 1 is a silica gel, light transmittance n ₁=1.40, medium 2 is an air, light transmittance n ₂=1 is got by the Si Nieer formula: θ _c=sin ^-1(n ₂/ n ₁)=sin ^-1° (1/1.40)=45

∵θ ₁≤30°、θ _c＝45°

∴θ ₁＜θ _c

Because incidence angle is less than critical angle, so can unreflectedly enter the space by the light of 120 °≤θ of angle of incidence of light in the silica gel inner light beam≤180 °.

Compared with the prior art, the major advantage that has of the present invention is:

One, areflexia, high light-emitting rate

The present invention has adopted areflexia unit WLED light source power dilatation encapsulation technology, the beam angle of unit WLED light source is increased substantially, in the inner unglazed reflection of unit WLED light source, the interference of light is very little between adjacent cells WLED light source, the light loss consumption is very little, makes light output efficiency increase optical efficiency more than 30% than common power dilatation expansion technique.

Two, scientific structure, reasonable, novel

1, this unit WLED light source power expanding type encapsulation is compared with common packaged type, and chip density is reduced relatively, and then thermal power density is corresponding reduces, and helps chip cooling, has improved chip light emitting efficient; Light-emitting area is increased relatively, and then light reduces light and dazzles the eyes by loss, increase luminous flux, reduction light by the corresponding increase of area.

2, because chip density reduces relatively, reduce the production difficulty, helped improving the finished product rate, reduced the procedure for producing cost.

3, light source heat radiation device and integral heat dissipation light fixture contact area are big, the heat radiation reinforcing mode is convenient, firm, help the heat radiation and the reinforcing of light source.

4, the WLED lens case that adopts engineering plastic PC to make has very strong very high impact strength, can improve the light source dependability dramatically.

5, fill a small amount of high transmission rate, high resiliency, high-termal conductivity, silicon gel in the PC lens case, it solidifies the back for gentle attitude, can alleviate tension force and led chip servo-actuated that led chip expands with heat and contract with cold.The PC shell has solved the external intensity of silicon gel.

Three, low cost

This unit WLED light source power expanding type encapsulation is compared with common packaged type, under same light flux condition, can reduce led chip consumption 30%, reduces silica gel consumption 40%, reduces cost of manufacture more than 20%, reduces raw-material cost thus significantly.

Four, perfect heat-dissipating, low-power consumption, optical efficiency height

This unit WLED light source power expanding type encapsulation is compared with common packaged type, because it has perfect heat-dissipating, and the advantage that light emission rate is high, led chip can be worked at a lower temperature, can improve the luminous efficiency of led chip significantly, reduce the led chip heat power consumption, reduce the electrical power consume.

Five, light decay reduces, the life-span is long

This unit WLED power expanding type high power WLED light source can reduce operating power under same light flux condition, the led chip long-term work is under smaller power, lower temperature, can make the optical attenuation of led chip very little, greatly the service life of the prolongation led chip of degree.

Description of drawings

Fig. 1 is the structural representation of present common great power LED illuminator.

Fig. 2 is that the silica gel media plane of common great power LED luminous body structure arrives air dielectric anaclasis (critical angle) schematic diagram.

Fig. 3 is the structural representation of high-power WLED light source of the present invention.

Fig. 4 is the areflexia schematic diagram of high-power WLED light source of the present invention.

Fig. 5 is the encapsulating structure schematic diagram of unit WLED chip.

Fig. 6 is a multiple-unit WLED dilatation structural representation.

Fig. 7 is BLED chip dress weldering schematic diagram.

Fig. 8 chooses schematic diagram for lens.

Fig. 9 is the structural representation of 50W street lamp WLED light source.

The specific embodiment

Referring to Fig. 3～Fig. 5, on heat-radiating substrate 1 by the determinant lamp battle array a plurality of chip light emitting width of the welding blue light BLED chip 2 that is 2w of arranging; Coat silica gel matter fluorescent material 3 above the BLED chip 2 at each, form white light WLED illuminator; The high strength industrial plastics PC that use has high transmission rate designs and produces into the hemispherical shell 5 of slim (0.2mm) uniform thickness by the H=R-0.577w-0.33h relational expression; Adopt identical light transmittance (n with PC ₁=1.40) high transparent silicon is gel-filled in the PC shell, forms silica gel packaged lens 4; Silica gel packaged lens 4 centerings are packaged in the fluorescent material top form areflexia high light-emitting rate unit WLED light source, become high-power WLED light source by each unit WLED combination of light sources dilatation.

Fig. 6 is a multiple-unit WLED dilatation structural representation, a plurality of unit WLED light sources of encapsulation on heat-radiating substrate 1, and the dilatation optical output power is to reach powerful requirement.

In Fig. 6, when X＞R, the angle that the unit WLED light source is sent can not enter in the other adjacent cells WLED light source silica-gel lens greater than the direct projection light of θ, and the distance between the adjacent cells WLED light source has certain restriction.Label I represents that light is former in lens among Fig. 6, and label II represents that the tangent lens of light pass through.

The distance of X=direct projection light and adjacent lens;

The R=lens radius;

Distance between the L=adjacent lens;

θ=minimum rising angle.

L＝X/sinθ

∵ direct projection light when X 〉=R can not enter adjacent lens

∴X _min＝R，L _min＝X _min/sinθ＝R/sinθ

L _min＝R/sinθ

That is: the distance L between the adjacent cells WLED light source 〉=R/sin θ.

The form that weldering of BLED chip dress and lens are chosen in the specific embodiment of the invention is distinguished as shown in Figure 7 and Figure 8, and the unit WLED light source adopts 1 * 1mm surface light emitting, metal substrate, single lead-out wire 8, blue light BLED chip 2.Its luminous width is: w=1/2=0.5mm, chip+fluorescent material height are: h=0.5mm.For the area of dissipation (Y) that guarantees chip, lead solder-joint intensity (Y2), voltage endurance (Y3), convenient produce (Y1) etc. get: Y=2w+0.2=1.4mm, Y1=0.3mm, Y2=0.8mm, Y3=0.4mm.Label 7 is a chip welding spot among Fig. 7, and 9 is the bonding wire point.

Choose in the form X at lens shown in Figure 8 _Min=Y/2+Y1+Y2+Y3

＝1.4/2+0.3+0.8+0.4＝2.2mm

That is: X 〉=X _Min=2.2mm;

Lens radius R _Min〉=X 〉=2.2mm,

H1＝R-H＝R-(R-0.557w-0.33h)

＝0.577w+0.33h＝0.577×0.5+0.33×0.5＝0.45，

That is: H1=0.45mm

$X=\sqrt{R^2-{\left(H1\right)}^2}=\sqrt{R^2-{0.45}^2}=\sqrt{R^2-0.2}=R\&times;\sqrt{1-\frac{0.2}{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="S2007100187056E00011.png"\; state="\{\{state\}\}">R</figure-callout>}}^2}}$

R _min＞X≥2.2mm，

When R=2.2mm, 0.2/R ²=0.2/2.2 ²=0.04

X＝0.98R

When R＞2.2mm, 0.2/R ²＜0.2/2.2 ²=0.04

X＝0.98R

That is: R 〉=2.2mm, R 〉=X 〉=0.98R

R≥X/0.98＝1.02X

R _min＝1.02X _min＝1.02×2.2＝2.25mm

That is: R 〉=2.25mm

In order to reduce cost, reduce the consumption of expensive material PC and high transparent silica gel, it is excessive that R can not choose, and R=2.5mm is advisable with selected value.

As led chip w=0.5mm, h=0.5mm; Minimum beam angle θ＜30 ° in order to improve light emission rate, gets minimum beam angle θ=25 °.

Then: H=R-0.577w-0.33h

＝2.5-0.577×0.5-0.33×0.5

＝2.04mm≈2.0mm

Get lens R=2.5mm, H=2.0mm, minimum beam angle θ=25 °

Then: the distance L between adjacent lens 〉=R/sin θ

＝2.5/sin(25°)＝5.9mm

Get: L=6.0mm.

Designer of the present invention has developed multiple high-power WLED light source on the basis of technique scheme, utilize high-power WLED light source to succeed in developing: WLED light fixture products such as street lamp, emergency light, mine laneway safety flare, mine cap lamp, subway and airport security illuminating lamp, hospital and hotel illuminating lamp, room lighting fluorescent tube, room lighting bulb.

Fig. 9 is the 50W street lamp WLED light source schematic diagram according to the technical solution of the present invention design.For applying on the copper aluminium base, the 3.0mm high thermal conductivity makes high-power printed circuit board thick by the connection in series-parallel relation, 52 unit WLED light sources of ultra-sonic welded encapsulation on aluminium base, form the high-power WLED light source of 50W, this light source is added on the shell that is affixed to the integral heat dissipation light fixture, promptly become light fixtures such as street lamp after adding control circuit.

Claims (2)

1. areflexia high light-emitting rate unit WLED power expanding type high power WLED light source, the heat-radiating substrate (1) that to it is characterized in that having a thickness be H1, being welded with a plurality of on heat-radiating substrate (1) is the BLED chip (2) of 2w by the determinant lamp battle array chip light emitting width of forming of arranging, on each chip (2), be coated with one deck silica gel matter fluorescent material (3) respectively, form white light WLED illuminator, chip (2) thickness+fluorescent material (3) thickness is h, go up each illuminator external application high transmission rate at heat-radiating substrate (1), it is that 0.2mm and light transmittance are the hemispherical shell of slim uniform thickness (5) of n1=1.40 that high strength industrial plastics PC is covered with a wall thickness respectively by the relational expression of H=R-0.577w-0.33h, H is the height of hemispherical shell (5) in the formula, R is the radius of hemispherical shell (5), R=H+H1, in hemispherical shell (5) and space that illuminator and substrate (1) surround, adopt and the high transparent silicon of the identical light transmittance of PC gel-filled in the PC shell formation silica gel packaged lens (4), form areflexia high light-emitting rate unit WLED light source thus, and then become high-power WLED light source by each unit WLED combination of light sources dilatation.

2. areflexia high light-emitting rate unit WLED power expanding type high power WLED light source according to claim 1 is characterized in that the distance L 〉=R/sin θ between adjacent lens (4), θ in the formula＜30 °.

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