CN202040673U - Integrated illumination device - Google Patents

Abstract

The utility model provides an integrated illumination device which comprises a plurality of LED (light-emitting diode) chips and is characterized in that the LED chips are packaged to be an LED module through silica gel to be fixed on a base plate; and the base plate is made of insulating ceramics. The heat-dissipation problem of an LED street lamp is found in the relationship between the high-power LED junction temperature and life, then the heat-dissipation problem is solved through direct heat dissipation of the LED chips, and at last, the effectiveness and advancement of the heat-dissipation design are detected through experiments. The integrated illumination device effectively solves the problem of luminous decay, so that the life of the LED street lamp is greatly prolonged, and the requirements of road illumination are achieved.

Description

The integrated form lighting device

Background technology

The utility model relates to the high-power LED light source field, is specifically related to a kind of integrated LED street lighting device.

Technical field

LED is as a kind of solid luminescence light source with great development potentiality, advantages such as its long-life, low-power consumption, little profile, multicolour, fast-response, environmental protection have obtained increasing people's attention, from initial indicator lamp, traffic signals, large screen display, Landscape Lighting in recent years also more and more are applied to functional lighting fields such as road lighting and tunnel illumination at present.

Also there are many bottleneck problems in the product development of LED street lamp, and the heat dissipation problem of LED street lamp is this product promotion key in application problem of restriction.A lot of people think that LED is that cold light source is exactly that temperature is low by mistake, and To Be Protected from Heat, and in fact the cold light source of LED is for the HID lamp, and HID light source envelope surfaces temperature is more than 200 ℃, and led light source can not be above 100 ℃.Along with the rising of LED temperature, the then corresponding reduction of its light output with the life-span.The semiconductor devices PN junction is when 45 ℃ of state work, and the theoretical life-span can reach 100000 hours.But, because led chip develops residing technological phase at present, can only make the electric energy of about 30% (also have and the article states 15%～25%) of input transform luminous energy, the mode that the electric energy of 70% (85%～65%) remains with heat is present on the chip, and LED optical efficiency and operating temperature are inversely proportional to, 10 ℃ of the every risings of temperature will cause the serious consequence that light decay 5%～8% and life-span reduce by half.Because the heat that LED produces adopts conduction pattern to distribute, so longer, more expensive path of these caloric requirements could be dispersed in the air fully and goes.A maximum commercialization obstacle of high-power LED illumination is exactly its heat dissipation problem at present, and therefore, the heat that how PN junction is produced in time conducts, and making the PN junction junction temperature remain on a lower level is the prerequisite that guarantees the light stability reliably working.In fact, the LED life problems mainly is owing to the problem of for a long time at high temperature working and forming, and is present, can only improve it as far as possible and dispel the heat and prolong the life-span of LED.

For this reason, Taiwan " the general life test draft standard of LED and module " requires the life test should be three temperature, the suggestion element carries out under 65 ℃, 85 ℃, 100 ℃ respectively, module carries out under 45 ℃, 65 ℃, 85 ℃ respectively, writes down the relational expression that the average life span (MTTF) of LED integral body under three temperature and MTTF and LED connect surface temperature.Domestic manufacturer is not owing to there is standard to follow, without restraint incredible service life of exaggerated propaganda and decay index.The life requirements that the star of american energy is worked out, be divided into and be not less than two grades of 35000h and 25000h, main cause is exactly: though the led chip life-span is very long, temperature after the element encapsulation, many factor relations such as heat radiation greatly will directly reduce the life-span, as not obscuring with the led chip life-span service life of LED street lamp.

The utility model content

The utility model provides a kind of integrated LED lighting device, and it can satisfy big electric current output, and satisfies the heat dispersion excellence.

A kind of integrated LED lighting device comprises several led chips, it is characterized in that, several led chips are packaged into a led module with silica gel and are fixed on the substrate, and described substrate adopts ceramic insulating substrate.

Wherein, also be close to one deck heat sink below the described ceramic insulating substrate.

Wherein, be connected with the copper post between described ceramic insulating substrate and the heat sink.

Wherein, described led module covers with lens.

Ask for an interview following description about the specific embodiment of the present utility model.

Description of drawings

Fig. 1 is the schematic diagram of integrated LED street lamp among the utility model embodiment 1;

Fig. 2 is the side view of integrated LED street lamp among the utility model embodiment 1;

Fig. 3 is the schematic diagram of integrated LED street lamp among the utility model embodiment 2.

The specific embodiment

Provide preferred embodiment of the present utility model below, these embodiment and unrestricted content of the present utility model.

Embodiment 1

Ask for an interview Figure 1 and Figure 2, embodiment of the present utility model provides a kind of integrated LED lighting device, comprise several led chips 1, several led chip 1 usefulness silica gel 4 are packaged into a led module 2 and are fixed on the ceramic insulating substrate 3, also are close to one deck heat sink 5 below ceramic insulating substrate 3.

So-called integrated LED module is exactly that a plurality of low-power LED chips 1 are formed the led module 2 that special circuit package becomes a super high power, and substrate of the prior art generally adopts traditional pcb board, and heat conductivility is bad.The utility model design adopts special ceramic insulating substrate 3 to replace pcb board, utilize characteristics such as the high heat conduction of special ceramics, high temperature resistant, good insulating, the heat that led chip 1 is produced can conduct to heat sink 5 by ceramic insulating substrate 3 rapidly, and dispels the heat by heat sink 5 and lamp outer casing.According to Fourier's heat conduction formula:

$Q=\mathrm{\λA}\frac{\mathrm{\ΔT}}{\mathrm{\δ}}\left(W\right)$

Q in the formula---heat, W;

A---perpendicular to the sectional area of heat conduction direction, m ²

δ---planomural thickness, m;

The thermal conductivity factor of λ---object materials, W/ (mK);

Δ T---the temperature difference on planomural both sides, K.

The heat flow of unit heat-conducting area is called heat flow density, that is:

$q=\frac{Q}{A}=\frac{\mathrm{\ΔT}}{\frac{\mathrm{\δ}}{\mathrm{\λ}}}(W/m^2)$

Integrated LED light source with 25 LEDs chips, about 30W power is an example, the about 1mm of led chip 1 area ², extremely thin because of ceramic insulating substrate 3, then led chip 1 with the heat conduction density of ceramic insulating substrate 3 is:

q1＝30/5×5×10 ^-6＝1.2×10 ⁶(W/m ²)

The thermal conductivity of the heat-conducting cream of contact position is 3.0W/ (mk), and average thickness is δ=0.03mm, and then the temperature difference of 1 of ceramic insulating substrate 3 and led chip is:

ΔT1＝q/(λ/δ)＝1.2×10 ⁶/(3/0.03×10 ^-3)＝12(℃)

Ceramic insulating substrate 3 is of a size of the circle of diameter 30mm, and then heat-conducting plate 5 with the heat conduction density of ceramic insulating substrate 3 is:

q2＝30/π×15×15×10 ^-6＝(2/15π)×10 ⁶(W/m ²)

The thermal conductivity of the heat-conducting cream of contact position is 3.0W/ (mK), and average thickness is δ=0.03mm, and then the temperature difference of 5 of ceramic insulating substrate 3 and heat-conducting plates is:

ΔT2＝q2/(λ/δ)＝(2/15π)×10 ⁶/(3/0.03×10 ^-3)＝4.2(℃)

This shows that heat-conducting plate 5 differs 16.2 ℃ with led chip 1 junction temperature, consider foozle, press heat-conducting plate 5 than low 18～20 ℃ of calculating of led chip 1 junction temperature, and the temperature of actual measurement heat-conducting plate 5 is not more than 60 ℃, so light source life (light decay to 70%) should be about 34000 hours.

Embodiment 2

In the utility model preferred embodiment, ceramic insulating substrate 3 and conducting strip 5 are connected together, outside led chip 1, go back outer cover lens 6 with the copper post 7 of led chip 1 below.Realized led chip 1 multiple heat dissipation, the diabatic process from led chip 1 to air is by three layers of stage, good heat dissipation effect.Use identical led chip, identical material after tested, the led chip under this direct radiator structure than the led chip of traditional radiator structure low 3%～5% (structure as shown in Figure 3).According to top fourier formula, to arrange for the distributing dot matrix because of led light source, the distribution area of 30 LEDs is corresponding with 1 LEDs to be multiplied, and calculates with single LEDs chip, about 1W light source, and then temperature rise is identical with 30, the about 1mm of led chip area ², heat conduction copper post 7 is of a size of 4mm, and then led chip 1 with the heat conduction density of copper post 7 is:

q1＝1/1×1×10 ^-6＝106(W/m ²)

The thermal conductivity of the heat-conducting cream of contact position is 3.0W/ (mK), and average thickness is δ=0.03mm, and then the temperature difference of 1 of heat conduction copper post 7 and led chip is:

ΔT1＝q/(λ/δ)＝10 ⁶/(3/0.03×10 ^-3)＝10(℃)

Consider foozle, led chip 1 bottom heat conduction copper post 7 should hang down 13～15 ℃ than LED junction temperature, so, make light source life (light decay to 70%) at 30000 hours.Table 1:

According to table 1 as can be known, the temperature of copper post 7 should be lower than 65 ℃.Heat conduction copper post 7 is of a size of 4mm, and then conducting strip 5 with the heat conduction density of heat conduction copper post 7 is:

q2＝1/π×2×2×10 ^-6＝(0.25/π)×10 ⁶(W/m ²)

The thermal conductivity of the conducting strip 5 of contact position is 3.0W/ (mK), and average thickness is δ=0.3mm, and then the temperature difference of 7 on conducting strip 5 and heat conduction copper post is:

ΔT2＝q2/(λ/δ)＝(0.25/π)×10 ⁶/(3/0.3×10 ^-3)＝7.96℃

This shows that conducting strip 5 differs 17.96 ℃ with the LED junction temperature, consider foozle, press conducting strip 5 than low 20～22 ℃ of calculating of LED junction temperature.

The utility model at first from great power LED junction temperature and life relation, has been analyzed the importance of LED road lamp cooling problem, and is from the direct heat radiation of led chip, last then, detected the validity and the advance of heat dissipation design by experiment.Solve the light decay problem effectively, thereby the life-span of LED street lamp is prolonged greatly, reached the requirement of road lighting.

Claims (4)

1. an integrated form lighting device comprises several led chips, it is characterized in that, several led chips are packaged into a led module with silica gel and are fixed on the substrate, and described substrate adopts ceramic insulating substrate.

2. integrated form lighting device as claimed in claim 1 is characterized in that, also is close to one deck heat sink below the described ceramic insulating substrate.

3. integrated form lighting device as claimed in claim 2 is characterized in that, is connected with the copper post between described ceramic insulating substrate and the heat sink.

4. integrated form lighting device as claimed in claim 3 is characterized in that described led module covers with lens.

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