CN100477307C

CN100477307C - Light-emitting diode

Info

Publication number: CN100477307C
Application number: CNB2007100368494A
Authority: CN
Inventors: 占贤武
Original assignee: Ningbo Andy Optoelectronic Co Ltd
Current assignee: Ningbo Andy Optoelectronic Co Ltd
Priority date: 2007-01-25
Filing date: 2007-01-25
Publication date: 2009-04-08
Anticipated expiration: 2027-01-25
Also published as: CN101071833A

Abstract

A light emitter diode including support and light emitter diode crystal grain which is fixed on the support, the light emitting surface of the LED is est with a layer of light transmission medium containing poly-dimethyl-silicone. The medium is a blended material formed by poly-dimethyl-silicone and a curing agent according to a certain proportion, which greatly reduces light emitter diode light fading rate, thus large scale enhance the light emitter diode service life.

Description

Light-emitting diode

[technical field]

The present invention relates to a kind of light-emitting diode, or rather, relate to a kind of low light decay, long-term durability luminous diode.

[background technology]

Light-emitting diode is a kind of light emitting semiconductor device, is used as indicator light, display screen etc. widely.Light-emitting diode be described as replace fluorescent lamps and incandescent lamp the 4th generation lighting source.Theoretical about 100000 hours of the life-span of light-emitting diode, but since light-emitting diode behind the generating positive and negative voltage of two ends when luminous, it promptly produces certain heat, if its heat is very fast being conducted not, will around wafer, heat spiral, this causes temperature to exceed the wafer junction temperature on the one hand, so that losing efficacy appears in wafer itself; Then cause peripheral encapsulating material on the other hand, insulating cement (elargol) or resin above the wafer or fluorescent material generation xanthochromia as bottom of wafer, so that the light that sends when wafer can the insulating cement of xanthochromia (elargol) or the resin that encapsulates above the wafer or phosphor substance absorb by it, cause the overall light efficiency of light-emitting diode a large amount of losses to occur, so that the light decay phenomenon occurred.From light-emitting diode product in the market, because the existence of above-mentioned light decay phenomenon, its life-span do not reach far away theoretical 100000 hours, generally in the time of 1000 hours, its light decay rate is stated more than 30%, thereby has shortened the life-span of light-emitting diode product to a great extent.

[summary of the invention]

Technical problem to be solved by this invention is to overcome above-mentioned defective, and a kind of low light decay, long-life LED are provided.

The present invention is achieved by the following technical solutions: a kind of light-emitting diode, comprise support, LED crystal particle, described LED crystal particle is fixed on the support, it is characterized in that: the light-emitting face of described LED crystal particle is provided with the light transmission medium that one deck contains the poly dimethyl silicone.

Described light transmission medium is allocated in 1: 1 ratio with curing agent by poly dimethyl silicone and LED package.

Described LED package curing agent is the bronsted lowry acids and bases bronsted lowry of dibutyl tin dilaurate or the catalytic action that can play the silanol condensation reaction or the solubility organic salt of lead, cobalt, tin, iron and other metal.

Described support is copper stent or retort stand.

Described LED crystal particle is fixed on the support by crystal-bonding adhesive, and described crystal-bonding adhesive is silver slurry or insulating cement.

Compared with prior art, the present invention on the light-emitting face of LED crystal particle forms light transmission medium that one deck contain poly dimethyl silicone by poly dimethyl silicone and LED package with the composite that curing agent forms in proportion by using, reduced the light decay rate of light-emitting diode widely, as when adopting standard 20mA current drives, in the time of 168 hours, its luminous flux has 5% rising, during by 336 hours, still keep 5% climbing, during by 504 hours, keep 8% climbing, during by 672 hours, still keep 10% climbing, during by 840 hours, still keep 9% climbing, during by 1008 hours, it optical attenuation still do not occur, still keeps rising 9%, thus the life-span of having improved light-emitting diode significantly.

[description of drawings]

Fig. 1 is under the kindred circumstances, and when adopting standard 20mA current drives, disclosed employing poly dimethyl silicone and LED package encapsulate and adopt traditional silica gel encapsulation carrying out light decay result of experiment curve chart with the curing agent composite.

Fig. 2 is under the kindred circumstances, and when adopting standard 40mA current drives, disclosed employing poly dimethyl silicone and LED package encapsulate and adopt traditional silica gel encapsulation carrying out light decay result of experiment curve chart with the curing agent composite.

[embodiment]

Disclosed light-emitting diode comprises support, LED crystal particle, and described LED crystal particle is fixed on the support, and the light-emitting face of described LED crystal particle is provided with the light transmission medium that one deck contains the poly dimethyl silicone.

In the present embodiment, it is the LED crystal particle of 455-465nm that described chip is selected the blue light emitting wavelength for use, crystal-bonding adhesive is with insulating cement (slurry can certainly mine for silver), LED support adopts retort stand (can certainly adopt copper stent), described light transmission medium (adopts dibutyl tin dilaurate by organosilicon material poly dimethyl silicone and LED package with curing agent in the present embodiment, can certainly be the bronsted lowry acids and bases bronsted lowry or the lead that can play the catalytic action of silanol condensation reaction, cobalt, tin, the solubility organic salt of iron and other metal) (quality in proportion, down together) allotment forms, in the present embodiment, poly dimethyl silicone, LED package is 1: 1 with the allotment ratio of curing agent.

The encapsulation process of the light-emitting diode that is disclosed in the present embodiment is for comprising the steps:

Step 1: some glue is about to insulating cement and clicks and enters in the support reflector.

Step 2: Gu brilliant, be about to above the support that ready prepd crystal grain is positioned over the insulating cement of having put.

Step 3:, make crystal grain and support fix adhesion Gu the baking of brilliant back is about to the semi-finished product of solid good crystal grain and puts into the high temperature baking box and toast.

Step 4: bonding wire, the crystal grain that soon toasts out is drawn two gold threads at both positive and negative polarity.

Step 5: join light transmission medium, promptly poly dimethyl silicone, LED package are taken out in proportion with curing agent at 1: 1, stir then, it is fully mixed, mixing time is about 5 minutes.

Step 6: vacuumize, promptly to carrying out vacuum defoamation by poly dimethyl silicone, LED package with the composite that curing agent is deployed into, the pumpdown time is about 5-10 minute.

Step 7: the some light transmission medium, the allotment object point that is formed with the curing agent allotment by poly dimethyl silicone, LED package that is about to have taken out vacuum forms the light transmission medium that one deck contains the poly dimethyl silicone on the light-emitting face of LED crystal particle.

Step 8: point toasts behind the light transmission medium, and the support that is about to the good light transmission medium of point is put into the high temperature baking box and toasted, so that its curing, temperature is at the 130-150 degree, and stoving time was at 1-2 hour.

Step 9: join glue, be about to the good A of preheating, B agent epoxy glue, be generally 1: 1 ratio and prepare, and stir, so that it fully mixes by certain.

Step 10: vacuumize, promptly the composite of preparing in the step 9 is carried out vacuum defoamation, the pumpdown time is about 5-10 minute.

Step 11: encapsulating, promptly utilize the encapsulating machine that glue is injected in die cavity or the support successively.

Step 12: toast behind the encapsulating, promptly carry out high-temperature baking, the adhesive curing that makes in the step 11 to be injected, baking temperature is 125 degree, time 8-10 hour.

Step 13: cut pin: promptly utilize diel, separately with its both positive and negative polarity.

Step 14: beam split, promptly utilize light splitting machine, classify according to relevant electrical parameters such as the voltage of product, brightness, colors.

Finished the encapsulation of above-mentioned light-emitting diode by above-mentioned steps, in order to verify the light decay situation of this kind light-emitting diode, the present invention has done a large amount of experiments.

See also shown in Figure 1ly, this figure is under the kindred circumstances, when adopting standard 20mA current drives, adopts poly dimethyl silicone and LED package to encapsulate and adopt traditional silica gel to encapsulate with the curing agent composite and carries out light decay result of experiment curve chart.From this figure we as can be seen, sequence number 1 is the product of traditional silica gel encapsulation, does not have light decay in the time of 168 hours, during by 336 hours, 2% decay occurs, during by 504 hours, 4% decay occurred, during by 672 hours, 6% decay occurs, during by 840 hours, 10% decay occurred, and in the time of 1008 hours, its light decay rate reaches 15%.The product that employing poly dimethyl silicone that sequence number 2 discloses for the present invention and LED package encapsulate with the curing agent composite, in the time of 168 hours, its luminous flux has 5% rising, during by 336 hours, still keep 5% climbing, during by 504 hours, keep 8% climbing, during by 672 hours, still keep 10% climbing, during by 840 hours, still keep 9% climbing, during by 1008 hours, it optical attenuation still do not occur, still keeps rising 9%.

The light decay situation of the light-emitting diode that employing poly dimethyl silicone that discloses for further checking the present invention and LED package encapsulate with the curing agent composite, when the inventor adopts standard 40mA current drives again, its light decay situation a large amount of experiments have been carried out.See also shown in Figure 2ly, when this figure was employing standard 40mA current drives, disclosed employing poly dimethyl silicone and LED package encapsulated and adopt traditional silica gel encapsulation carrying out light decay result of experiment curve chart with the curing agent composite.From this figure we as can be seen, sequence number 1 is the product of traditional silica gel encapsulation, in the time of 168 hours, its light decay rate reaches 14%, during by 336 hours, its light decay rate reaches 22%, during by 504 hours, its light decay rate reaches 33%, optical attenuation is very serious.The product that employing poly dimethyl silicone that sequence number 2 the present invention disclose and LED package encapsulate with the curing agent composite, its luminous flux has 5% rising in the time of 168 hours, during by 336 hours, still keep 5% climbing, during by 504 hours, still keep 5% climbing, optical attenuation still do not occur.This shows that the product of the more traditional silica gel encapsulation of disclosed light-emitting diode has very low light decay, the very long life-span.

Need to prove that above-mentioned kindred circumstances is meant: (1) each experiment is all carried out under same laboratory, same time period and environmental condition; (2) each test event all is 20 light-emitting diodes randomly drawing from some single tubes wherein, as the sample of test.

The present invention produces on the basis of a large amount of experiments, the inventor is through a series of experiment, the chip of a large amount of encapsulating materials and light-emitting diode is carried out matching test, final discovery is used and is encapsulated with the composite that curing agent forms in proportion by poly dimethyl silicone and LED package, can reduce the light decay rate of light-emitting diode widely, the life-span of improving light-emitting diode significantly.

More than describing is embodiments of the invention only, forgives and can understand, and under the prerequisite that does not depart from the present invention's design, to simple modification of the present invention and replacement, all should be included within the technical conceive of the present invention.

Claims

1. light-emitting diode, comprise support, LED crystal particle, described LED crystal particle is fixed on the support, it is characterized in that: the light-emitting face of described LED crystal particle is provided with the light transmission medium that one deck contains the poly dimethyl silicone, and described light transmission medium is allocated in 1: 1 ratio with curing agent by poly dimethyl silicone and LED package.

2. light-emitting diode as claimed in claim 1 is characterized in that: described LED package curing agent is the solubility organic salt of the bronsted lowry acids and bases bronsted lowry of dibutyl tin dilaurate or the catalytic action that can play the silanol condensation reaction or lead, cobalt, tin, iron.

3. light-emitting diode as claimed in claim 1 is characterized in that: described support is copper stent or retort stand.

4. light-emitting diode as claimed in claim 1 is characterized in that: described LED crystal particle is fixed on the support by crystal-bonding adhesive, and described crystal-bonding adhesive is silver slurry or insulating cement.