CN100433383C - Light emitting device and light emitting element - Google Patents

Abstract

A light emitting device having: a predetermined optical form that is provided on a surface of an LED element mounted on a base, the predetermined optical form being made to allow an increase in efficiency of taken out light from an inside of the LED element; and a sealing material that seals the predetermined optical form. The sealing material has a refractive index of 1.6 or more, the predetermined optical form is formed in a surface of a substrate of the LED element, and the substrate has a refractive index nearly equal to that of a light emitting layer of the LED element.

Description

Light emitting devices and manufacture method thereof and photocell

The application is based on 2004-253447 number and the 2005-204983 Japanese patent application, and its full content is hereby incorporated by.

Technical field

The present invention relates to light emitting devices and photocell, and specifically, relate to a kind of light emitting devices, can be from wherein taking out the light of having launched from photocell and a kind of photocell effectively.

Background technology

By being known go up the conventional method that growth makes LED (light emitting diode) element by the semiconductor crystal of making based on the compound semiconductor of III group-III nitride such as sapphire base substrate (base substrate).Occur such problem in this LED element: the light that has produced in light-emitting layer is limited in having in the layer of high optical absorption coefficient or is absorbed in this layer, and has reduced thus to the radiation efficiency of outside.

In order to address this problem, uneven (unevenness) to be provided to the surface of the LED element of some types, thereby to increase the taking-up efficient (seeing for example disclosed 2003-69075 Japanese patent application (Fig. 1, [0011])) of light.

At disclosed 2003-69075 Japanese patent application (Fig. 1, [0011]) in the LED element described in, based on the compound semiconductor layer (being known as semiconductor layer hereinafter) of gallium nitride based on GaN by stratification on Sapphire Substrate forming the GaN substrate, and other semiconductor layer at its top stratification successively subsequently based on GaN.Sapphire Substrate is removed from this stratification body, and goes up the execution etching in the rear surface of GaN substrate (stratification has the surface of the surface opposite of element on it), and forms the pit of stepped form thus.

At disclosed 2003-69075 Japanese patent application (Fig. 1, [0011]) in the LED element described in, the rear surface of GaN substrate has specific forms, produced the pit of stepped form there, therefore by preventing light can be got the outside effectively by based on the interference of light that multipath reflection caused in the semiconductor layer of GaN.

Yet at disclosed 2003-69075 Japanese patent application (Fig. 1, [0011]) in the LED element described in, take out the ability be limited in based on the light in the semiconductor layer of GaN (being limited in the light in the layer) and depend on refringence with respect to the black box of component ambient, and based on respect to the refringence of black box and take place under the state from the reflection at interface, even, can not obtain the ability of enough taking-up light carrying out in the uneven situation about handling on the surface at element.In addition, although can be limited in realizing that based on the light in the semiconductor layer of GaN light takes out the increase of efficient that this is not desirable form or any situation that approaches this by scattering.Also go wrong about this light that is limited in the layer: when long propagation was with induced attenuation in light has the layer of big optical absorption coefficient, light quantity was reduced, in addition, and the heat increase that in element, is produced.

Therefore, the purpose of this invention is to provide a kind of light emitting devices, can be from wherein taking out the light of having launched from photocell and a kind of photocell effectively.

Summary of the invention

The purpose of this invention is to provide a kind of light emitting devices, the predetermined optical form that wherein is used to make the efficient of taking out light from the inside of LED element to increase is provided to the surface that is installed in the LED element in the substrate (base), it is sealed in refractive index and is not less than in 1.6 the encapsulant, and above-mentioned predetermined optical form is formed in the substrate that has with the approximately uniform refractive index of light-emitting layer of above-mentioned LED element.

(1) according to an aspect of the present invention, light emitting devices comprises:

Substrate, this substrate comprise and are formed on two lip-deep circuit pattern that described circuit pattern is electrically connected to each other by via hole;

Predetermined optical form, it is provided on the surface that is installed in suprabasil LED element, and this predetermined optical form makes the efficient of taking out light from the inside of LED element increase; And

Encapsulant, it seals described LED element,

Wherein said encapsulant has 1.6 or above refractive index,

Described predetermined optical form is formed in the surface of substrate of LED element,

Described substrate has refractive index with the light-emitting layer of LED element near the refractive index that equates, and

Described predetermined optical form is formed by the light transmitting material layer, and described light transmitting material layer has the refractive index of mean value of the refractive index of the light-emitting layer that is not less than described LED element and encapsulant.

(2) according to another aspect of the present invention, light emitting devices comprises:

Predetermined optical form, it is provided on the surface that is installed on suprabasil LED element, and this predetermined optical form makes the efficient of taking out light from the inside of LED element increase; And

Encapsulant, it seals described predetermined optical form,

Wherein said encapsulant has 1.6 or above refractive index,

Described predetermined optical form is formed in the surface of the semiconductor layer that exposes by the substrate that peels off the LED element.

(3) according to another aspect of the present invention, photocell comprises:

Semiconductor layer, it comprises: light-emitting layer; Predetermined optical form, it is provided on the surface of this semiconductor layer, and this predetermined optical form makes the efficient of taking out light from the inside of LED element increase; And the electrode part, it is provided on another surface of this semiconductor layer,

Wherein said predetermined optical form is the uneven surface with stepped form, and described stepped form is not more than sin with respect to the angle of inclination of the normal direction of light-emitting layer^-1(n2/n1) (wherein n1 is the refractive index of the light-emitting layer of LED element, and n2 is the refractive index of encapsulant).

(4) according to another aspect of the present invention, make the method for light emitting devices, may further comprise the steps:

LED with substrate is provided element;

Peel off described substrate from described LED element;

Form predetermined optical form on the surface of described LED element, described predetermined optical form makes to be increased from the efficient of described LED element internal taking-up light;

The LED element is installed in the substrate; And

With refractive index be 1.6 or above encapsulant be hot-pressed onto in the described substrate so that seal described LED element.

Description of drawings

Figure 1A-1C illustrates the light emitting devices according to first embodiment; Figure 1A is vertical viewgraph of cross-section, and Figure 1B is the viewgraph of cross-section that the amplifier section of LED element is shown, and Fig. 1 C illustrates the diagram that light takes out the amplifier section of the LED element surface on the side;

Fig. 2 is the vertical viewgraph of cross-section that the configuration of described LED element is shown;

Fig. 3 A-3D is the diagram of explanation according to the manufacture process of the light emitting devices of first embodiment;

Fig. 4 is the viewgraph of cross-section that illustrates according to the light emitting devices of second embodiment;

Fig. 5 A-5C illustrates the LED element according to the 3rd embodiment; Fig. 5 A illustrates the plan view that takes out the observed LED element of side from light, and Fig. 5 B is the viewgraph of cross-section along the line A-A of Fig. 5 A, and Fig. 5 C is illustrated in light to take out the diagram that the amplifier section of the uneven form that forms is gone up on the surface;

Fig. 6 A-6C illustrates the LED element according to the 4th embodiment; Fig. 6 A illustrates the plan view that takes out the observed LED element of side from light, and Fig. 6 B is the viewgraph of cross-section along the line B-B of Fig. 6 A, and Fig. 6 C is illustrated in light to take out the diagram that the amplifier section of the uneven form that forms is gone up on the surface;

Fig. 7 A-7C illustrates the LED element according to the 5th embodiment; Fig. 7 A illustrates the plan view that takes out the observed LED element of side from light, and Fig. 7 B is the viewgraph of cross-section along the line C-C of Fig. 7 A, and Fig. 7 C is illustrated in light to take out the diagram that the amplifier section of the uneven form that forms is gone up on the surface;

Fig. 8 A and 8B illustrate the LED element according to the 6th embodiment; Fig. 8 A illustrates the plan view that takes out the observed LED element of side from light, and Fig. 8 B illustrates the diagram of how taking out light from the projection of Fig. 8 A;

Fig. 9 A and 9B illustrate the LED element according to the 7th embodiment; Fig. 9 A illustrates the plan view that takes out the observed LED element of side from light, and Fig. 9 B is the viewgraph of cross-section along the line D-D of Fig. 9 A;

Figure 10 is the vertical viewgraph of cross-section that illustrates according to the light emitting devices of the 8th embodiment;

Figure 11 is the vertical viewgraph of cross-section that flip-chip (flip chip) the type LED element according to the 9th embodiment is shown;

Figure 12 is the vertical viewgraph of cross-section that illustrates according to the flip chip type LED element of the tenth embodiment;

Figure 13 is the vertical viewgraph of cross-section that illustrates according to the flip chip type LED element of the 11 embodiment;

Figure 14 is the vertical viewgraph of cross-section that illustrates according to the flip chip type LED element of the 12 embodiment;

Figure 15 A and 15B illustrate the LED lamp according to the 13 embodiment; Figure 15 A is the vertical viewgraph of cross-section that the LED lamp is shown, and Figure 15 B is mounted in the vertical viewgraph of cross-section of the LED element on the LED lamp; And

Figure 16 is a curve chart, its illustrate the refractive index of indicating sealing material and light to the radiation efficiency of LED element-external than between the curve of relation.

Embodiment

(first embodiment)

(configuration of light emitting devices 1)

Figure 1A-1C illustrates the light emitting devices according to first embodiment; Figure 1A is vertical viewgraph of cross-section, and Figure 1B is the viewgraph of cross-section that the amplifier section of LED element is shown, and Fig. 1 C illustrates the diagram that light takes out the amplifier section of the LED element surface on the side.

Shown in Figure 1A, thislight emitting devices 1 is by making based on the compound semiconductor of III group-III nitride, and has: flip chiptype LED element 2, and it hasuneven form part 20A on light takes out surface on the side; Al₂O₃Substrate 3, it is an inorganic substrate,LED element 2 is mounted thereon; Glass capsulation part 4, it is made by inorganic encapsulant; And Au stud bumps (studbump) 5, being used for the electrode ofLED element 2 is electrically connected tocircuit pattern 30,circuit pattern 30 is formed on Al by tungsten (W)₂O₃On thesubstrate 3.

Al in this cross section₂O₃Substrate 3 has throughhole 31, and by being provided at thecircuit pattern 30 on the both sides that the current-carrying part of being made by W in these throughholes 31 is connected electrically in this substrate.

Glass capsulation part 4 is by based on SiO₂-Nb₂O₅The low-melting glass of (refractive index n=1.8) forms, and hasplanar side 41 and flat upper surfaces 40.

According to present embodiment,LED element 2 forms with smooth form, shown in Figure 1B, and is formed and has W₁=300 μ m and H₁=10 μ m.Herein, be 460nm from theseLED element 2 wavelength of light emitted.

In addition, inLED element 2, shown in Fig. 1 C,projection 20a (w₁=4 μ m, h₁=2 μ m) and flat 20b (w₂=8 μ m) be set at light and take out on the surface on the side, thereby form uneven form part 20A.This part is known asuneven form part 20A and forms a depression because stride across the neighboringprojection 20a of flat 20b.

(configuration of LED element 2)

Fig. 2 is the vertical viewgraph of cross-section that the configuration of described LED element is shown.LED element 2 is by stratification n-GaN:Si layer 20 successively on the Sapphire Substrate (not shown), InGaN layer 21, and GaN layer 22, AlGaN layer 23, MQW 24, p-AlGaN layer 25, p-GaN layer 26 and p⁺-GaN layer 27 is as forming based on thesemiconductor layer 100 of GaN.In addition, this LED element has at p⁺P-electrode 28 on the-GaN layer 27 and then electrode 29 on the expose portion of n-GaN:Si layer 20 wherein pass through from p⁺-GaN layer 27 beginning, carry out etching up to n-GaN:Si layer 20 and remove described layer.Unevenform part 20A comprises above-mentionedprojection 20a and flat 20b, and they are formed on the surface of n-GaN:Si layer 20.

Although the method that is used to form based on thesemiconductor layer 100 of GaN is not limited especially, it can be by means of well-known mocvd method (MOCVD method), molecular beam epitaxy accretion method (MBE method), form based on halid chemical gaseous phase depositing process (HVPE method), sputtering method, ion electroplating method, electronic shower (electron shower) method or the like.Herein, the configuration of LED element can be homostyructure (homo structure), heterostructure (hetero structure) or double-heterostructure.In addition, can adopt quantum well structure (single quantum or multi-quantum pit structure).

(manufacture process of light emitting devices 1)

Fig. 3 A-3D is the diagram of explanation according to the manufacture process of the light emitting devices of first embodiment.The process be used for making the light emitting devices that uses in advance theLED element 2 that forms in separate processes is below described.

(installation process of LED element 2)

At first, as shown in Figure 3A, prepareLED element 2 and Al₂O₃Substrate 3 and location Al₂O₃Circuit pattern 30 on thesubstrate 3 and the electrode on theLED element 2make LED element 2 be electrically connected tocircuit pattern 30 via Au stud bumps 5, and are installed in Al simultaneously₂O₃On the substrate 3.Then,LED element 2 and Al₂O₃Gap between thesubstrate 3 is filled in wherein with unshowned space packing material.Preferably, this space packing material has little thermal coefficient of expansion.

(process of peeling off of Sapphire Substrate S)

Next, shown in Fig. 3 B, at Sapphire Substrate S side laser beam irradiation LED element 2.By the irradiation of laser beam, Sapphire Substrate and be melted based on the interface between thesemiconductor layer 100 of GaN.Consequently, the Sapphire Substrate S that peels off from thesemiconductor layer 100 based on GaN is removed.At this moment, residue can be stayed on the surface based on thesemiconductor layer 100 of GaN, therefore carries out pickling removing residue, thereby exposes n-GaN:Si layer 20.

(forming process ofuneven form part 20A)

Next,, comprise etching, on the light taking-up surface ofLED element 2, formuneven form part 20A by laser radiation by carrying out uneven the processing.Unevenness with approximately perpendicular step is formeduneven form part 20A.

(using the glass capsulation process of low-melting glass)

Next, use based on SiO₂-Nb₂O₅LED element 2 andLED element 2 and the Al of glass to having formeduneven form part 20A on it₂O₃Hot-pressing processing is carried out in gap between the substrate 3.As the result of this hot-pressing processing, described glass adheres to the surface of uneven form part 20A.In addition, this glass is caught to adhere to Al₂O₃The surface ofsubstrate 3, thus,whole LED element 2 is sealed in the glass.After glass capsulation, encapsulation is divided into single by cutting (dicing), obtains having thelight emitting devices 1 of upper surface 40 andside 41 like this.Herein, except cutting, it also is possible coming separate package by the separation method such as groove (scribing).

(work of light emitting devices 1)

As Al from above-mentioned light emitting devices 1₂O₃When thecircuit pattern 30 of the bottom-exposed ofsubstrate 3 is connected to unshowned power subsystem with energy supply, current-carrying part via throughhole 31, voltage is applied between the n electrode and p electrode ofLED element 2 with forward, and the compound of hole and electronic carrier taken place in the MQW24 ofLED element 2, make light be launched.The light that will take out surface emissivity from light never planar inform part 20A enters glass capsulation part 4, glass capsulation part 4 is crossed in transmission, and be radiated the outside, take out in the middle of the described light that only from the described smooth emission process among MQW 24, is produced that is removed.

(effect of first embodiment)

Obtain following effect according to first embodiment.

(1) Sapphire Substrate S is from being installed in Al₂O₃LED element 2 on thesubstrate 3 is removed,uneven form part 20A with approximately perpendicular step is provided toLED element 2, thus, with with theconventional LED element 2 that is formed at GaN on the smooth Sapphire Substrate in identical mode, the light that enters radiation on the direction of Sapphire Substrate at light with the angle that is not more than critical angle from GaN can be got the outside of described element.In addition, when light enters the uneven part ofuneven form part 20A, enter radiation on the direction of Sapphire Substrate with the angle that is not less than critical angle from GaN and be limited in the outside that light in the layer ofLED element 2 inside also can be got described element at light.The mode of the light of the uneven surface radiation that the performance of the light that is radiated outside from the flat surfaces of uneven surface and step never form is identical, and in addition, the light that is limited in the layer is radiated outside from the vertical ledge surface of uneven surface.Therefore, the light quantity of radiation can increase on the GaN course.

In addition, described vertical cross section is with respect to the normal slope of the light-emitting layer of GaN layer, and therefore is provided on the direction that makes about the solid angle maximum of the light that limited in the layer, and this is the factor that increases described effect.In addition, the light of the boundary reflection from described vertical cross section does not change the size about the angle of light-emitting layer normal direction.

(2) in addition, according to first embodiment, Sapphire Substrate S is removed, and as an alternative, uses based on SiO₂-Nb₂O₅The glass with n=1.8, and therefore, become about 50 degree about the critical angle θ c of LED element 2.Described encapsulant can be selected as making the critical angle θ c between this LED element 2 and glass capsulation part 4 to become and be not less than 45 ℃, and therefore, compare with Sapphire Substrate with n=1.7, being limited in passing through in the layer can be reduced based on the light quantity of semiconductor layer 100 horizontal transmissions of GaN, in addition, being limited in the possibility that is radiated element-external based on the light in the semiconductor layer 100 of GaN when entering uneven form part 20A uprises.In addition, have the thickness of 10 μ m based on the semiconductor layer 100 of GaN, and the possibility that light arrives uneven form part 20A is high, therefore, light can be radiated outside with high efficient in desirable level.In addition, even because the restriction of technology, under the situation of the flatness deficiency of uneven surface, the encapsulant with high index of refraction compensates for this reason, thus, can realize providing and approach the characteristic of the efficient of the attainable limit in theory.Herein, uneven formation is carried out on p-GaN:Si layer 20, and this leafing MQW 24 has a distance, and MQW 24 is based on the light-emitting layer in the semiconductor layer 100 of GaN, therefore, is forming the damage that can avoid when uneven light-emitting layer.Therefore, internal quantum efficiency can be kept, and the radiation efficiency of light can be increased greatly to LED element 2 outsides.

(3) LED element 2 is sealed in the glass capsulation part 4, it is stable for the optical wavelength of being launched and has good optical transmission characteristics, obtain light emitting devices 1 thus, it is stable for long-time section that its light takes out characteristic and it has good durability, even in the situation of the high performance type LED element 2 that uses a large amount of light of emission.Particularly, in the same high situation with desirable level of internal quantum efficiency, the radiation efficiency of LED element 2 outsides of light to the smooth Sapphire Substrate S can be increased to 75% from 25%.At this moment, heat emission is reduced to and is not more than 1/3.In addition, because heat emission reduces, make the magnitude of current that allows to flow through double to become possibility, thus, as the increase of the efficient of LED element 2 with allow the result of the cooperative effect between the increase of the magnitude of current that flows through, light quantity can be increased.In addition, the highdensity light radiation that has for such has guaranteed stable optical transmission characteristics.In addition, even because the restriction of technology, in the situation of the flatness deficiency of uneven surface, the encapsulant with high index of refraction compensates for this reason, thus, can realize providing and approach the characteristic of the efficient of the attainable limit in theory.In addition, this device is for having the only stable of the wavelength that is not more than 470nm, and for example, therefore the wavelength of 365nm, can be used to hold the ultraviolet LED element of emission.

In addition, the refractive index of present widely used epoxy resin or silicones is about 1.5.Yet many existing glass materials provide high transmissison characteristic, and the high index of refraction that is not less than 1.6.By using this glass material, can implement to be sealed in whereinLED element 2 with high-index material, therefore, can increase the efficient of taking out light fromLED element 2.

(4) in addition, form the Al of encapsulation₂O₃The thermal coefficient of expansion ofsubstrate 3 and glass capsulation part 4 is approximate identical, thus, can provide such structure, wherein is difficult for taking place such as the inconvenience of breaking that is caused by thermal stress.As a result, obtained except that reliability, also can increase the effect that allows the current value that flows through for thermal shock.Because having limited, the glass transformation temperature (Tg point) of epoxy resin, conventional epoxy sealing allow the electric current that flows through.This is because become greatly being not less than the temperature place thermal coefficient of expansion that Tg order, and disconnects easily in electrical connections.The Tg point of glass capsulation part 4 than the Tg point of epoxy resin high 300 ℃ or more than, and be not higher than the temperature place that Tg is ordered, its thermal coefficient of expansion is not more than 1/7 of epoxy resin.

(5) Al₂O₃The material ofsubstrate 3 and glass capsulation part 4 is selected as having identical thermal coefficient of expansion, andLED element 2 is caught to become the upside-down mounting type of not using the Au line, realizes having the glass capsulation of the highly stable LED element of high index of refraction thus.That is to say, not causing the mode of breaking or peeling off, handle glass high viscosity state under, and when processing, can prevent fire damage that LEDelement 2 is caused by applying high pressure by the difference between treatment temperature and the room temperature.In addition, Al₂O₃Substrate 3 and glass capsulation part 4 are carried out chemical combination via oxide, and therefore provide high-intensity adhesion.In addition, used flip chiptype LED element 2, thereby it is unnecessary that the line space is become, therefore provide to be encapsulated into possibility for a short time.

(6) from the surface that LEDelement 2 is installed circuit pattern is read into Al₂O₃The rear surface ofsubstrate 3, thus can manufacture a product with good productivity ratio.That is to say that theLED element 2 of big figure is installed in Al₂O₃On thesubstrate 3, and can glass capsulation be embodied as collective's technology (collective process) by using glass plate.

(7) at the Al that LEDelement 2 is installed in as substrate₂O₃After on thesubstrate 3 Sapphire Substrate S is peeled off,uneven form part 20A is provided then, therefore, might easily form the encapsulation of the various encapsulants except that glass capsulation part 4, as, for example epoxide resin material, the fluorogen (fluorophore) that comprises the light-transmissive resin material and the glass material that comprises fluorogen.In addition, also makeuneven form part 20A easily, wherein uneven form is corresponding to the refringence with respect to encapsulant.

Herein, when with the long-pending configuration combination of the light emitting surface that is used to increaseLED element 2, above-mentioned to be used to strengthen theuneven form part 20A that light takes out characteristic be effective.For example, can to increase light emitting surface for ratio based on the occupied area of the p electrode of thesemiconductor layer 100 of GaN long-pending by being used for supply of current in the area that increases this element.In addition, can use Ag paste or weldering plating (solder plating) rather than projection (bump) to carry out installation.At this moment, the contact electrode ofGaN semiconductor layer 100 and external terminal electrode separately provide via insulating barrier.

In addition, the p electrode can be formed by ITO with optical transmission characteristics (tin indium oxide) and metallic reflective coating.Reflect from ITO by the light that is limited in the layer based onsemiconductor layer 100 horizontal transmissions of GaN, and thus, absorbing the loss that causes by metal when reducing the light arrival metallic reflective coating in being limited in layer becomes possibility, and can increase the light quantity that is radiated outside fromLED element 2.

In addition, ITO and Al₂O₃Have approximately uniform thermal coefficient of expansion, and ITO and GaN be caught relative adhering to each otherly doughtily, therefore, when the processing that is used for glass capsulation, can prevent that electrode is owing to thermal stress is peeled off.

Herein, although encapsulant is a glass in the foregoing description, yet the sealing material can be the glass of partially crystallizableization when handling or the inorganic material that is not in glassy state, and identical effect is provided.

(second embodiment)

(configuration of light emitting devices 1)

Fig. 4 is the viewgraph of cross-section that illustrates according to the light emitting devices of second embodiment.Thislight emitting devices 1 is to use the surface installing typelight emitting devices 1 according to theLED element 2 of first embodiment, and has: resin chamber (case) part, and it is made by the white resin material such as nylon, has the container part 10A that is used to holdLED element 2; Sub-bearing (sub-mount) 6, it is made by AlN, andLED element 2 is mounted thereon; Silicone resin (silicone resin) hermetic unit 7 is used forLED element 2 and sub-bearing 6 that integral sealing is accommodated in the container part 10A of resin chamber part 10; Leadportion 9 is used for supply of current and givesLED element 2, and sub-bearing 6 is fastened on thisLED element 2; And line 8, be used forlead portion 9 is electrically connected to sub-bearing 6.Herein, in the following description, identical reference number is attached to have and the configuration identical in first embodiment and the part of function.

LED element 2 is installed on the sub-bearing 6 as substrate, afterwards, with mode identical in first embodiment, provideuneven form part 20A by peeling off Sapphire Substrate S.Herein, the space betweenLED element 2 and the sub-bearing 6 is used by SiO₂The unshowned space filler of making is filled in wherein.

Sub-bearing 6 has thecircuit pattern 60 at upper surface and lower surface, and it is formed byW.Circuit pattern 60 on upper surface and the lower surface is electrically connected by the W current-carrying part that is provided in the through hole 61.In addition, the circuit pattern 6 from the p electrode side that is connected toLED element 2 in the middle of thecircuit pattern 60 is electrically connected to leadportion 9 by the line of being made by Au 8.

Silicone encapsulation part 7 has the refractive index of n=1.5, and has sealingLED element 2 and sub-bearing 6 and function that will be from the light radiation ofLED element 2 emissions to the outside of resin chamber part 10.Herein, silicone encapsulation part 7 can comprise by the light activated fluorogen from 2 radiation of LED element, and also might form wavelength conversion typelight emitting devices 1, it is used for from the light of the fluorogen radiation that is stimulated and light from the basis of the mixing emission predetermined color of the light ofLED element 2 radiation.

(effect of second embodiment)

According to second embodiment, taking out theLED element 2 that hasuneven form part 20A on the surface at light is sealed in the silicone encapsulation part 7, thus, can obtain having the surface installing typelight emitting devices 1 of high brightness, wherein the light of propagating as the inner transverse of passing throughLED element 2 that is limited in the light in the layer can be radiated outside effectively.

Herein, the refractive index described in first embodiment based on SiO with n=1.8₂-Nb₂O₅Glass can become integral body with the form of layer with theuneven form part 20A of describedLED element 2 in a second embodiment by hot-pressing processing, and becomewhole LED element 2 and sub-bearing 6 with this glass and can be sealed in the silicone encapsulation part 7.In such a case, light enters the silicone encapsulation part 7 with n=1.5 via the glass assembly with n=1.8 from theLED element 2 with n=2.4, therefore and can reduce generation by the caused total reflection of refringence between the material, making to increase radiation from the light ofLED element 2 emissions to the outside.

(the 3rd embodiment)

(configuration of LED element 2)

Fig. 5 A-5C illustrates the LED element according to the 3rd embodiment; Fig. 5 A is the plan view that takes out the observed LED element of side from light, and Fig. 5 B is the viewgraph of cross-section along the line A-A of Fig. 5 A, and Fig. 5 C illustrates to be formed on the diagram that light takes out the uneven form part of lip-deep amplification.In thisLED element 2,uneven form part 20A is formed hasprojection 20a that fine pith is arranged and the micro-form of flat 20b, shown in Fig. 5 A and5B.LED element 2 has the width W of 300 μ m₁And with foursquare form formation.The thickness H ofLED element 2₁Be 6 μ m, and haveuneven form part 20A on the surface of light taking-up side.

Uneven form part 20A is by on the surface of taking out side atlight projection 20a (w being set₁=2 μ m, h₁=1 μ m) and flat 20b (w₂=2 μ m) form, shown in Fig. 5 C.

(effect of the 3rd embodiment)

According to the 3rd embodiment,uneven form part 20A takes out on the side with the light that shallow and micro-form is provided atLED element 2, and therefore, when unevenness is handled, can prevent damage that MQW is caused, and can obtain the stablereliable LED element 2 of light emission characteristics.In addition, shallow by the uneven degree of depth is become, by when making light emitting devices, exerting pressure, can prevent from after the process that sealsuneven form part 20A with encapsulant, in unevenness, to stay bubble.Herein, the top surface of described projection be foursquare form and have around groove, and therefore, the space-time air-capacitor is easily overflowed exerting pressure.

(the 4th embodiment)

(configuration of LED element 2)

Fig. 6 A-6C illustrates the LED element according to the 4th embodiment; Fig. 6 A is the plan view that takes out the observed LED element of side from light; Fig. 6 B is the viewgraph of cross-section along the line B-B of Fig. 6 A, and Fig. 6 C illustrates to be formed on the diagram that light takes out the uneven form part of lip-deep amplification.ThisLED element 2 is large-sized LED elements 2 and to have 1000 μ m width W₁Rectangular in form form, shown in Fig. 6B.LED element 2 has the thickness H of 6 μ m₁And on the surface of light taking-up side, hasuneven form part 20A.

Shown in Fig. 6 C,projection 20a (w₁=2 μ m, h₁=1 μ m) and flat 20b (w₂=2 μ m), and the area dividing that will be formed withprojection 20a and flat 20b become 9deep trench 20c (w₃=5 μ m, h₂=4 μ m), be arranged on the surface of light taking-up side, and formuneven form part 20A thus.

In addition,LED element 2 has: n electrode 20n, and it is provided as being positioned in the part that is formed withdeep trench 20c;P electrode 20p, it is provided on the surface of the side opposite withuneven form part 20A; AndMQW 20d, it is by coming radiative light-emitting layer vian electrode 20n andp electrode 20p power supply.

(effect of the 4th embodiment)

According to the 4th embodiment, it is shallow that the unevenness ofuneven form part 20A is formed among theuneven form part 20A that makes on being provided in the light taking-up side ofLED element 2, and therefore, with with mode identical in the 3rd embodiment, when handling, unevenness can prevent the damage of MQW20d, therefore, can obtain launching theLED element 2 of even light.In addition, it is shallow by the uneven degree of depth is become, by when making light emittingdevices 1, exerting pressure, can prevent from after the process that sealsuneven form part 20A with encapsulant, in unevenness, to stay bubble, and can prevent the deterioration of sealing characteristics and the dispersion of optical characteristics.

In addition, by providedeep trench 20c inuneven form part 20A, the light based onsemiconductor layer 100 horizontal transmissions of GaN that passes throughLED element 2 that is limited in the layer enters all sides ofgroove 20c, and makes light radiation to the outside thus.Consequently, in large-sized LED element 2, improved the characteristic of taking out light.Herein, although described large-sized LED element 2 according to the 4th embodiment, the present invention is applicable to the standard-sized LED element 2 described in first embodiment (square with 300 μ m limits).

In addition, be formed with the zone that becomes the p of light emitter region contact electrode and be divided into 9, and as shown in Figure 6A, as seeing from the front, each p contact electrode district bydeep trench 20c around.Consequently, by based onsemiconductor layer 100 horizontal transmissions of GaN to around light be radiated outside from each p contact electrode based on thesemiconductor layer 100 of GaN.Described n contact electrode is formed directly under thedeep trench 20c, does not have the MQW that becomes light-emitting layer there, and therefore, established deep trench does not influence and directly is present in following light-emitting layer.

(the 5th embodiment)

(configuration of LED element 2)

Fig. 7 A-7C illustrates the LED element according to the 5th embodiment; Fig. 7 A is the plane graph that takes out the observed LED element of side from light, and Fig. 7 B is the viewgraph of cross-section along the line C-C of Fig. 7 A, and Fig. 7 C is illustrated in light to take out the uneven form part that the amplification that forms is gone up on the surface.ThisLED element 2 is theLED elements 2 by following formation: form the semiconductor layer 201 based on AlInGaP that refractive index is similar to GaAs refractive index of substrate (n=3.5) on the GaAs substrate, shown in Fig. 7 B, and remove the GaAs substrate by grinding, make GaP substrate 200 (n=3.5) adhere to this semiconductor layer subsequently; And be formed and have 300 μ m width W₁Square form.By grindingGaP substrate 200,LED element 2 is formed has 100 μ m thickness H₁The surface of taking out side at light hasuneven form part 20A.

Shown in Fig. 7 C,uneven form part 20A is by following formation: by with cutting machine (dicer) cutting, provideprojection 20A (w on light takes out surface on the side₁=50 μ m, h₁=25 μ m) and flat 20b (w₂=50 μ m), on described surface, provide micro-flatness by chemical etching subsequently.

(effect of the 5th embodiment)

According to the 5th embodiment, GaP substrate 200 takes out on the side at light and is ground to required thickness, in addition, by uneven form part 20A is provided with cutting machine cutting, obtains having the LED element 2 that good light takes out characteristic thus.In addition, can prevent at processing damage during light-emitting layer this moment GaP substrate 200 sides.In the situation of the GaP of n=3.5 substrate 200, when uneven form part 20A is formed when having above-mentioned size, approximately the encapsulant of n=2.4 is used, and is radiated the outside of LED element 2 and does not have the total reflection of the light of horizontal transmission when entering uneven form part 20A thereby may make from the light of the end emission of LED element 2.Be difficult to carry out the encapsulant that is used for LED element 2 that surpasses as the n=2 of present level in practice.Yet even in the situation that can not be implemented to outside light radiation with desirable level, light also can be caught from the uneven side of the stepped form of near vertical to be in covering from 90 °-sin with respect to the light-emitting layer normal direction^-1(n1/n2) solid angle to the polarizers of big angle scope of 90 ° direction is radiated outside (, n1 is the refractive index of the light-emitting layer of LED element 2, and n2 is the refractive index of encapsulant) herein.Especially, this form and n=1.6 or above encapsulant combination can obtain thus than much higher increase in the situation of the epoxy sealing that does not have processed and use n=1.5 in described form.

In uneven step part, can form the tapering (inclination angle) of the restriction of light-emitting layer with LED element and the critical angle between the encapsulant herein.In this restriction, can provide the effective uneven side of stepped form.That is to say that this inclination is provided so that light is radiated outside with 90 ° of directions with respect to the light-emitting layer normal direction, this makes described solid angle maximum.In addition, this LED element can form by the following: with the light-emitting layer and the substrate combination with refractive index identical with this photocell ofLED element 2, for example, GaN substrate and based on the semiconductor layer of GaN, perhaps SiC substrate and based on the semiconductor layer of GaN replaces byGaP substrate 200 with based on the semiconductor layer 201 formed stratification structures of AlInGaP.

(the 6th embodiment)

(configuration of LED element 2)

Fig. 8 A and 8B illustrate the LED element according to the 6th embodiment; Fig. 8 A is the plan view that takes out the observed LED element of side from light, and how Fig. 8 B is used for illustrating the diagram of taking out light in the part of the projection form of Fig. 8 A.ThisLED element 2 hasuneven form part 20A, wherein the aggregate of hexagon form (collective body) is set up (interval with 10 μ m) via flat 20b with staggered form, and in each of these aggregates, theprojection 20a (height with 2 μ m) of three rhombus forms (adjacent step side forms 60 ° or 120 °) is combined on the surface of the n-GaN:Si layer that light takes out, shown in Fig. 8 A.

As the light L that produces in the MQW of LED element 2 (not shown), not shown, when enteringprojection 20a, shown in Fig. 8 B, thereby it enters second side 211 from 210 total reflections of first side.Second side 211 andfirst side 210 form acute angle, and when incidence angle became less than critical angle θ c, the light L that enters second side 211 was radiated the outside.This is becauseprojection 20a is formed and has such side: the angle between them is bigger 2 times or more many times than critical angle θ c.

(effect of the 6th embodiment)

According to the 6th embodiment,projection 20a is formed has such side: the angle between them is bigger 2 times or more many times than critical angle θ c, therefore, the light L that can prevent to enterprojection 20a becomes and is in the not light from the pattern thatprojection 20a is radiated outside, therefore, enteredprojection 20a be limited in the layer in light can be radiated outside.

In addition,uneven form part 20A is formed by the aggregate ofprojection 20a, and therefore, the light that is limited in the layer is radiated outside effectively becomes possibility.Herein, although in the 6th embodiment, described the configuration that 7uneven form part 20A are set with alternative form, the configuration shown in the setting of the projection among theuneven form 20A is not limited to, but theuneven form part 20A of arbitrary number can be provided.

(the 7th embodiment)

(configuration of LED element 2)

Fig. 9 A and 9B illustrate the LED element according to the 7th embodiment; Fig. 9 A is the plan view that takes out the observed LED element of side from light, and Fig. 9 B is the viewgraph of cross-section along the line D-D of Fig. 9 A.Shown in Fig. 9 A, thisLED element 2 hasuneven form part 20A, its each have:hexagon projection 20d, wherein hexagonal shape outside the surface that the n-GaN:Si layer takes out light forms; Andgroove 20e, intersected with each other thereby it is created within the upper surface of thishexagon projection 20d with 60 degree, and theseuneven form part 20A are arranged on the flat 20b with staggered form.

(effect of the 7th embodiment)

According to the 7th embodiment, the light that eachuneven form part 20A that is made byhexagon projection 20d andgroove 20e is provided atLED element 2 takes out on the surface, thus, the light that entershexagon projection 20d with the high form of possibility that light enters with high efficiency never the planar in form partial radiation to outside, therefore, the light radiation that is limited in the layer and enters the side of the side ofhexagon projection 20d andgroove 20e can be increased to the efficient of outside.

(the 8th embodiment)

(configuration of light emitting devices 1)

Figure 10 is the vertical viewgraph of cross-section that illustrates according to the light emitting devices of the 8th embodiment.Thislight emitting devices 1 is different from the first embodiment part and is, in the 8th embodiment, the glass capsulation part 4 of light emittingdevices 1 has the optical form surface 42 of hemisphere form.Thecircuit pattern 30B that LEDelement 2 is installed on it is connected to Al by the via pattern 30c that is provided in the through hole 31₂O₃Circuit pattern 30A on the basal surface of substrate 3.In addition, be 1.9 at the refractive index n of the glass capsulation part 4 shown in this diagram, andLED element 2 form with the square form with W=300 μ m.

When the glass capsulation part 4 of hemisphere form was provided, the optical form surface 42 around theLED element 2 was the optical form that the light from 2 radiation of LED element can vertically enter in the ideal case.Herein, the critical angle θ on optical form surface 42 becomes θ=sin^-1° (n0/n2)=31.8, air refraction n0=1.0 and the refractive index of glass capsulation part 4 is n2=1.9 wherein, although and for the light that enters with the angle in the restriction that is in critical angle θ total reflection does not take place, but near-5 ° critical angle θ, boundary reflection is tending towards increasing, and a kind of optical form preferably is provided, and its permission is so that the angle in the little scope of described boundary reflection and the light quantity that enters increases.

(effect of the 8th embodiment)

According to the 8th embodiment, obtaining with the LED element is radius (highly) L of initial point, the width W of element and with respect to the θ=tan that concerns between the critical angle θ on optical form surface 42^-1(W/2L), in the 8th embodiment, when radius L is not less than 0.24mm, can suppress boundary reflection takes out efficient to light effect thus by size and the critical angle θ that regulates above-mentioned LED element 2.Therefore as mentioned above, glass capsulation part 4 is provided as making that the optical form surface 42 of hemisphere form is provided with the radius that is not less than L, and can obtain that boundary reflection is suppressed and light takes out thelight emitting devices 1 of characteristic good.

In addition, with surface C by sphering so that the form at the edge that does not have the angle is provided, as in cuboid form (rectangular parallelepiped form), can suppress boundary reflection by increasing L, although this form is different from the hemisphere form.

(the 9th embodiment)

(configuration of LED element 2)

Figure 11 is the vertical viewgraph of cross-section that illustrates according to the flip chip type LED element of the 9th embodiment.

ThisLED element 2 has: n-GaN layer 113, and it is formed by the GaN semiconducting compound; Light-emittinglayer 114, its by stratification on n-GaN layer 113; P-GaN layer 115, its by stratification on light-emittinglayer 114;N lateral electrode 116, it is provided on the n-GaN layer 113, and this layer exposes from the part of p-GaN layer 115 to n-GaN layer 113 by remove scope by etching; And p lateral electrode 118, it is provided on the p-GaN layer 115, and is different from the first embodiment part and is, and according to the 9th embodiment, taking out on the side at the light of n-GaN layer 113 provides by tantalum oxide (Ta₂O₅) light-transmitting layer 119 of the material with high index of refraction made, rather than theuneven form part 20A of theLED element 2 described in first embodiment.

By heating by means of the electron-beam vapor deposition method and gasification raw material Ta₂O₅, the material layer 119 with high index of refraction is formed the film thickness with 1 μ m on the surface of n-GaN layer 113.Ta₂O₅Refractive index with n=2.2, and based on the refractive index ratio with respect to n-GaN layer 113, critical angle θ c is 66 °.In addition, according to the electron beam deposition method, rough surface part 119A is formed on the surface of the material layer with high index of refraction 119 on the light taking-up side.(effect of the 9th embodiment)

According to the 9th embodiment, by the Ta of n=2.2₂O₅The material layer made from high index of refraction 119 is provided on the surface of n-GaN layer 113, can realize the expansion of solid angle thus.In addition, at Ta₂O₅Film when forming, work as Ta₂O₅On the surface of n-GaN layer 113, form rough surface part 119a during recrystallization, therefore can be provided at the light diffusion performance in the interface betweenLED element 2 and the outside, and can increase light and take out efficient.

Herein, above-mentioned material layer 119 with high index of refraction can be by Ta₂O₅Material in addition forms, and can be, for example, and ZnS (n=2.4), SiC (n=2.4), HfO₂(n=2.0), ITO (n=2.0), GaN (n=2.4), TiO₂, ZnO, SiC or the like.Be used for film formed these materials and need not be electric conducting material, and can be any material with high-adhesiveness and superior optical characteristics.

(the tenth embodiment)

(configuration of LED element 2)

Figure 12 is the vertical viewgraph of cross-section that illustrates according to the flip chip type LED element of the tenth embodiment.

This flip chiptype LED element 2 has such configuration, and wherein thermal coefficient of expansion is 7.0 * 10^-6/ ℃ ITO contact electrode 120 be provided rather than the p lateral electrode 118 of theLED element 1 described in the 9th embodiment.

(effect of the tenth embodiment)

According to the tenth embodiment, ITO is provided contact electrode, its thermal coefficient of expansion is approximate identical with thermal coefficient of expansion based on thesemiconductor layer 100 of GaN, therefore and obtainLED element 2 highly reliably, wherein except the preferred effect of the 9th embodiment, also increased the adhesiveness of described p lateral electrode, made that the p lateral electrode can be as peeling off to encapsulation process produced the heat ofLED element 2 or with the result of the heat of light emission emission.In addition, because the electric current diffusion property of ITO, photoemissive inhomogeneities can be reduced.Herein, the p lateral electrode can be formed by the conductive oxide material except that ITO.

(the 11 embodiment)

(configuration of LED element 2)

Figure 13 is the vertical viewgraph of cross-section that illustrates according to the flip chip type LED element of the 11 embodiment.

This flip chiptype LED element 2 is to obtain by thesemiconductor layer 100 of growth on GaN substrate 130 based on GaN, and it is the square with 340 μ m limits and 100 μ m thickness.

(effect of the 11 embodiment)

According to the 11 embodiment, obtained concerning t 〉=W/ (2tan (sin between therefractive index n 3 of therefractive index n 2 of size W, glass capsulation part 4 of thickness (thickness of side) t, theLED element 2 of GaN substrate 130 and LED element 2^-1(n2/n3))), make and be radiated all light of GaN substrate 130 not from the interface total reflection between GaN substrate 130 and the glass capsulation part 4 fromsemiconductor layer 100 based on GaN, and therefore, in light emitting devices shown in Figure 10 1, use in the situation of GaN substrate 130, wherein, for example, W=300 μ m, n2=1.9, n2=2.4, by the thickness t 〉=116 μ m that make GaN substrate 130, the characteristic of taking out light fromLED element 2 rises to desirable efficient.Confirm, even take out characteristic and also increase when only about half of value time that thickness t has a upper limit herein.In such a case, the GaN substrate 130 of cuboid form is in optical form, thus avoid having high luminous absorptance based on the optical loss in thesemiconductor layer 100 of GaN and make the increase of taking out the efficient of light become possibility from element internal.

Figure 16 illustrates analog result, and it illustrates the dependence of the efficient comparison encapsulant refractive index that is radiated standard LED element-external.This analog result is to use the model of the predetermined form with following physical values to obtain: epitaxial loayer, substrate layer and encapsulant refractive index, transmittance, optical attenuation distance separately, thus produce 100 ten thousand light beams by means of the beam ray tracing method.Herein, the value of refractive index pointer optical wavelength that photocell is launched.Be used as the element of substrate for Sapphire Substrate, and this element seals with the encapsulant with refractive index of 1.58, obtained the fiducial value of outside radiation efficiency ratio.

In Figure 16, curve A illustrates the outside radiation efficiency ratio of LED element (standard component) of the cuboid form of using Sapphire Substrate,curve B 0 illustrates the radiation efficiency ratio that uses the GaN substrate or have LED element-external substrate, the cuboid form of the refractive index identical with GaN, andcurve B 1 illustrates and uses the GaN substrate or have the substrate of the refractive index identical with GaN and carried out the radiation efficiency ratio of the LED element-external of surface-treated cuboid form on it.The yardstick of all cuboid forms is W=300 μ m, the thickness t of semiconductor layer=6 μ m, and the thickness of substrate is 84 μ m (116 μ m 72% thickness).This is that lip-deep treated form is the situation of prism (base with 2 μ m) with 45 ° of angles of inclination.Herein, even in the situation that the angle of inclination changes in ± 15 ° scope, indicatrix does not have big change yet, and keeps roughly the same.This is because light is radiated encapsulant from photocell to become than being easier to, and also becomes than being easier to when the angle of inclination increases the adjacently situated surfaces that the time reenters in the treated form simultaneously.

In the refractive index of encapsulant is not less than 1.6 situation, can obtain being not less than the big increase of 80% efficient with respect to fiducial value.The refractive index of encapsulant is not less than 1.7 and to be not more than 2.1 be better.In refractive index is not less than 1.7 situation, is radiated encapsulant from the LED element and can be similar to the efficient of outside and reaches desirable level.On the other hand, in the too high situation of the refractive index of encapsulant, this causes entering from encapsulant the reduction of the radiation efficiency of air.That is to say that the restriction in the form that total reflection is not taken place becomes excessive, and when light perpendicular to the interface during incident boundary reflection become big.Therefore, the refractive index of the encapsulant of LED is desirable with the ratio of the refractive index of light-emitting layer in 0.68 to 0.85 scope.

, will be provided to the configuration of GaN substrate 130 based on thesemiconductor layer 100 of GaN herein, theLED element 2 that for example provides on the SiC substrate based on thesemiconductor layer 100 of GaN also can be provided although in the 11 embodiment, described.In addition, after on Sapphire Substrate, having grown, can eliminate (lift-off) by means of laser and remove Sapphire Substrate based on thesemiconductor layer 100 of GaN, and as the material layer with high index of refraction, GaN substrate 130 can be so that be adhered to described semiconductor layer.

At this moment, not to epitaxially grown restriction, the lattice constant of lattice constant and epitaxially grown layer is identical to be unnecessary, and epitaxial loayer is that monocrystalline also is unnecessary in having the material layer of high index of refraction.This epitaxially grown layer only has the optical transmission characteristics that is used for optical module, and satisfied refractive index is enough with the thermal coefficient of expansion that is used to be connected.Therefore, except GaN, this epitaxially grown layer can also be TiO₂, Ga₂O₃, ZnO or the like, perhaps can be any polycrystal in these.

(the 12 embodiment)

(configuration of LED element 2)

Figure 14 is the vertical viewgraph of cross-section that illustrates according to the flip chip type LED element of the 12 embodiment.

This flip chiptype LED element 2 is to provide thepart 130A (with surface C in the corner of substrate by the form of sphering) that is cut with 45 ° of angles of inclination to obtain by GaN substrate 130 turnings at the LED of the 11embodiment element 2.

(effect of the 12 embodiment)

According to the 12 embodiment, can obtaincurve B 1 with Figure 16 identical to outside radiation efficiency, describedcurve B 1 illustrates the preferred effect of the 11 embodiment, and can be fetched in the medium with low-refraction with high efficiency by the light ofLED element 2 horizontal transmissions.In addition, such element form can be provided, wherein all light that are radiated GaN substrate 130 from thesemiconductor layer 100 based on GaN are not from the interface total reflection between GaN substrate 130 and the glass capsulation part 4, even when the thickness of GaN substrate 130 is not more than 116 μ m.In addition, can make in this format surface be treated as easy.

Obtain 200% radiation efficiency ratio and become possibility by in this format surface, carrying out such processing, even in this element usefulness situation that for example encapsulant of n=1.7 seals to outside.Has n=1.9 or above high-index material has such characteristic, make that absorption loss water is tending towards increasing in the short wavelength zone, and can be implemented to the increase of outside radiation efficiency with the encapsulant of about n=1.7, therefore, except blue, bluish-green or the like, the LED element that also the present invention is applied near the ultraviolet light of emission wavelength 370nm becomes easy.

(the 13 embodiment)

Figure 15 A and 15B illustrate the LED lamp according to the 13 embodiment; Figure 15 A is the vertical viewgraph of cross-section of this LED lamp, and Figure 15 B is mounted in the vertical viewgraph of cross-section of the LED element on this LED lamp.

This LED lamp 70 obtains by following: light emittingdevices 1 is installed on thelead portion 9, wherein seal in the 2 usefulness glass capsulation parts 4 of the LED element shown in Figure 15 B, in addition, these are integrated in the covering module of being made by the transmittance resin (overmold) 51.Cover module 51 and have optical form surface 51A, it is the hemisphere form, makes light to be radiated outside from light emittingdevices 1 with high efficiency.

InLED element 2, thedepression 113A with groove form of the preset width and the degree of depth arranges with grid on the light taking-up surface of n-GaN layer 113, and provides by Ta on this surface₂O₅The material layer made from high index of refraction 119.On the surface of material layer 119, form rough surface part 119A by means of the electron-beam vapor deposition method with high index of refraction.

(effect of the 13 embodiment)

According to the 13 embodiment, the depression 13A of groove form arranges with grid, and theLED element 2 with material layer 119 of high index of refraction is provided in its surface, therefore the area of theLED element 2 of light taking-up is expanded, and light takes out the surface and comprises horizontal surface and vertically surperficial, and has therefore improved light and taken out efficient.In addition, the material layer with high index of refraction 119 with rough surface part 119A is provided on the surface of n-GaN layer 113, therefore, be limited in light interior and that propagate by n-GaN layer 113 and before arriving a side, can be radiated outside, and the critical angle of this moment can enlarge by the material layer 119 with high index of refraction from thedepression 113A of groove form.Therefore, can obtain having thelight emitting devices 1 of high brightness.

In addition, light emittingdevices 1 forms byLED element 2 is sealed in the glass, therefore and has a good mechanical strength, feasible encapsulation process by means of injection molding becomes possibility, and cover module 51 can easily be formed on light emittingdevices 1 around, therefore, the productivity ratio of LED lamp 70 is good.

Although for complete and clearly open, at specific embodiment the present invention has been described, but claims should not limit thus, and should be understood that to embody whole modifications and replaceable structure in the basic instruction that those skilled in the art can expect clearly drops on this paper and set forth.

Claims (33)

1. light emitting devices comprises:

Substrate, this substrate comprise and are formed on two lip-deep circuit pattern that described circuit pattern is electrically connected to each other by via hole;

Predetermined optical form, it is provided on the surface that is installed on described suprabasil LED element, and this predetermined optical form makes increases the efficient of taking out light from described LED element internal, and described LED element is electrically connected with one of described circuit pattern; And

Encapsulant, it seals described LED element,

Wherein said encapsulant has 1.6 or above refractive index,

Described predetermined optical form is formed in the surface of LED component substrate,

Described substrate has and the approaching refractive index that equates of the refractive index of LED element light-emitting layer, and

Described predetermined optical form is formed by the light transmitting material layer, and described light transmitting material layer has the refractive index of mean value of the refractive index of the light-emitting layer that is not less than described LED element and encapsulant.

2. light emitting devices comprises:

Predetermined optical form, it is provided on the surface that is installed on suprabasil LED element, and this predetermined optical form makes increases the efficient of taking out light from described LED element internal; And

Encapsulant, it seals described predetermined optical form,

Wherein said encapsulant has 1.6 or above refractive index,

Described predetermined optical form is formed in the surface of the semiconductor layer that exposes by the substrate that peels off described LED element.

3. according to the light emitting devices of claim 2, wherein:

Described predetermined optical form is formed by the light transmitting material layer, and described light transmitting material layer has the refractive index of mean value of the refractive index of the light-emitting layer that is not less than described LED element and encapsulant.

4. according to the light emitting devices of claim 1 or 2, wherein:

Described predetermined optical form is a uneven surface, and this uneven surface has the part of stepped form, and the part of described stepped form is not more than sin with respect to the angle of inclination of light-emitting layer normal direction^-1(n2/n1), wherein n1 is the refractive index of LED element light-emitting layer, and n2 is the refractive index of described encapsulant.

5. according to the light emitting devices of claim 4, wherein:

Described predetermined optical form is the uneven surface with vertical stepped form.

6. according to the light emitting devices of claim 4, wherein:

Described uneven surface is that groove is formed on uneven part form on every side.

7. according to the light emitting devices of claim 4, wherein:

The part of described stepped form has such form: side adjacent one another are is in contact with one another with different angles.

8. according to the light emitting devices of claim 7, wherein:

The part of described stepped form forms with the rhombus form.

9. according to the light emitting devices of claim 1 or 2, wherein:

Described predetermined optical form is to have multi-form and uneven form different depth by combination to form.

10. according to the light emitting devices of claim 3, wherein:

In described predetermined optical form, described light transmitting material layer is formed in such a manner has thickness t, makes

t≥W/(2tan(sin^-1(n1/n2)))

Wherein W is the width of described element, and n1 is the refractive index of described encapsulant, and n2 is the refractive index of described LED element.

11. according to the light emitting devices of claim 3, wherein:

Described light transmitting material layer has the part that is cut, and wherein, the angle of described light transmitting material layer is cut, so that inclined surface is provided.

12. according to the light emitting devices of claim 3, wherein:

With respect to the refractive index of described light-emitting layer, the ranges of indices of refraction of described encapsulant from 0.68 to 0.85.

13. according to claim 1,10 or 11 light emitting devices, wherein:

Many conical surfaces are formed in the described predetermined optical form.

14. according to the light emitting devices of claim 1 or 2, wherein:

The external form of described encapsulant forms with an optical surface form, and wherein the light from described LED element emission enters with the angle that is different from critical angle, and this critical angle is recently limited by the refractive index with respect to described encapsulant.

15. according to the light emitting devices of claim 1 or 2, wherein:

Described encapsulant is a light transmitting material, and its refractive index satisfies

n1·sin45°＜n2

Wherein n1 is the refractive index of the light-emitting layer of described LED element, and n2 is the refractive index of described encapsulant.

16. according to the light emitting devices of claim 1 or 2, wherein said photocell upside-down mounting is in described substrate.

17. according to the light emitting devices of claim 15, wherein:

Described encapsulant is the inorganic material with optical transmission characteristics.

18. according to the light emitting devices of claim 17, wherein:

Described inorganic encapsulant is a glass.

19. according to the light emitting devices of claim 17 or 18, wherein:

Described substrate is the inorganic material substrate, and it has the thermal coefficient of expansion identical with described encapsulant, has wherein formed the conductive pattern that is used for to described photocell supply power.

20. according to the light emitting devices of claim 19, wherein:

Described conductive pattern has at the pattern on the side that described photocell has been installed, the pattern on its rear side and the pattern that is used to be electrically connected described both sides.

21. according to the light emitting devices of claim 1 or 2, wherein:

Described LED element is made by the semiconductor based on GaN.

22. according to the light emitting devices of claim 21, wherein:

Described encapsulant has and is not less than 1.7 refractive index.

23. a photocell comprises:

Semiconductor layer, it comprises light-emitting layer; Predetermined optical form, it is provided on the surface of described semiconductor layer, and this predetermined optical form makes increases the efficient of being permitted to take out from the inside of LED element light; And the electrode part, it is provided on another surface of semiconductor layer,

Wherein said predetermined optical form is the uneven surface with stepped form, and described stepped form is not more than sin with respect to the angle of inclination of light-emitting layer normal direction^-1(n2/n1), wherein n1 is the refractive index of the light-emitting layer of LED element, and n2 is the refractive index of described encapsulant.

24. according to the photocell of claim 23, wherein:

Described predetermined optical form is formed in the surface of described LED component substrate, and

Described substrate has and the approaching refractive index that equates of the refractive index of described LED element light-emitting layer.

25. according to the photocell of claim 23, wherein:

Described predetermined optical form is formed in the surface of the semiconductor layer that exposes by the substrate that peels off described LED element.

26. according to any one photocell in the claim 23 to 25, wherein:

Described predetermined optical form is the uneven surface with stepped form of near vertical.

27. according to any one photocell in the claim 23 to 25, wherein:

Described stepped form is such form: side adjacent one another are is in contact with one another with different angles.

28. according to the photocell of claim 27, wherein:

Described stepped form is the rhombus form.

29. according to any one photocell in the claim 23 to 25, wherein:

Described predetermined optical form is to have multi-form and uneven form different depth by combination to form.

30. according to any one photocell in the claim 23 to 25, wherein:

Described LED element is made by the semiconductor based on GaN.

31. according to the photocell of claim 30, wherein said encapsulant has and is not less than 1.7 refractive index.

32. a method of making light emitting devices may further comprise the steps:

LED with substrate is provided element;

Peel off described substrate from described LED element;

Form predetermined optical form on the surface of described LED element, described predetermined optical form makes to be increased from the efficient of described LED element internal taking-up light;

Described LED element is installed in the substrate; And

With refractive index be 1.6 or above encapsulant be hot-pressed onto in the described substrate so that seal described LED element.

33. method according to claim 32 further may further comprise the steps:

After described sealing step, described LED element is divided into a plurality of described light emitting devices with described substrate.

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