CN101944559B

CN101944559B - Light-emitting diode

Info

Publication number: CN101944559B
Application number: CN 200910150088
Authority: CN
Inventors: 林志胜; 吴哲雄
Original assignee: Ubilux Optoelectronics Corp
Current assignee: Ubilux Optoelectronics Corp
Priority date: 2009-07-09
Filing date: 2009-07-09
Publication date: 2013-01-23
Anticipated expiration: 2029-07-09
Also published as: CN101944559A

Abstract

The invention provides a light-emitting diode comprising a base material, an action membrane and an electrode unit; particularly, the action membrane comprises a bottom connected with the base material and a platform part extending upwards from the bottom; the bottom comprises an opening region, a middle region, a first region and a second region, wherein, the middle region extends towards the first direction from the opening region; the first region and the second region are positioned at the two sides opposite to the opening region and the middle region; the electrode unit comprises a first electrode and a second electrode, wherein, the first electrode is arranged on the opening region; the second electrode is arranged on the top surface of the platform part; the width specific value of the first region and the second region which are vertical to the first direction is between 0.6 to 0.95; and the light-emitting efficiency of the light-emitting diode can be effectively promoted by utilizing the specific setting of the width specific value of the first region and the second region which are vertical to the first direction.

Description

Light-emitting diode

Technical field

The present invention refers in particular to a kind of high brightness LED relevant for a kind of light-emitting diode.

Background technology

Consult Fig. 1, Fig. 2, at present horizontal light emitting diode (Light EmittingDiode; LED) comprise a rectangle base material 11, one action film 12 and an electrode unit 13, this base material 11 is made of by material sapphire, it is luminous that this action film 12 can photoelectric effect when accepting the electric energy that this electrode unit 13 provides, comprise that in kenel a bottom 121 that is connected with this base material 11 and is from 121 upwardly extending sections in this bottom 122, this bottom 121 has one is extended and the open area 123 and that is square contains the perimeter 124 of this open area 123 of embedding to another short side direction by a minor face wherein, and this one 122 is upwards integrally formed from this perimeter 124; Structurally, this action film 12 has that a n-type semiconductor layer and that is connected with this base material 11 is connected on this n-type semiconductor layer and forms the p-type semiconductor layer of p-n junction (p-n junction) with this n-type semiconductor layer, when electrical energy flows is moved film 12 by this, can produce electron-hole recombinations and produce light with the p-n junction that wherein forms at this p-type semiconductor layer, this N-shaped semiconductor layer.

This electrode unit 13 have one be formed on this open area 123 and relative with the first electrode 131 of this n-type semiconductor layer ohmic contact and one away from these the first electrode 131 ground be formed on this perimeter 124 and with the second electrode 132 of this p-type semiconductor layer phase ohmic contact, when the external world cooperates when electric energy is provided to this action film 12 by this first electrode 131, this second electrode 132, this action film 12 can photoelectric effect convert the electric energy of acceptance to that luminous energy is backward to be sent outward.

For present horizontal light emitting diode, although really can be luminous when electric energy is provided, but because this first electrode 131, this second electrode 132 is light tight, therefore can be because this first electrode 131 when producing luminous energy, blocking of this second electrode 132 and lose the light quantity that major part is outwards sent, and by this first electrode 131, this second electrode 132 cooperates when electric energy is provided to this action film 12, also easily because this first electrode 131, being shaped as simple rectangular design of this second electrode 132 and so that the uniformity that electric current injects is not good, and then allow the luminous efficiency of element also be affected simultaneously.

The problem that the luminous efficiency that causes for the structure of improving because of electrode reduces has many methods to the electrode structure improvement to be suggested successively.

Consult Fig. 3, Fig. 4, at present common with different electrode structural designs and in order to improve the horizontal light emitting diode structure of the diffusion uniformity that electric current injects, itself and above-mentioned horizontal light emitting diode structure are similar, difference is in this second electrode 132 and has one first electrode block 133, one first extension 134 and one second extension 135, this first electrode block 133 is arranged on the position of close another minor face for relative these the first electrode 131 ground correspondences, this first extension 134 is extended to these the first electrode 131 directions by this first electrode block 133, extend along this open area 123 this second extension 135, and the center of this second extension 135 is connected with the end of this first extension 134, utilize described symmetrical electrode structural designs, motor current is injected into the dispersed homogeneous degree in this semiconductor layer, to promote the luminous efficiency of LED.

Consult Fig. 5, Fig. 6, in addition, United States Patent (USP) US6,847, No. 052 case, but the LED structural design of another kind improving luminous efficiency is then disclosed, its structure and above-mentioned horizontal light emitting diode structure are similar, difference is in its base material 11 and is square, this open area 123 is by the fan-shaped extension of the general one-tenth in a wherein corner of this base material 11, this electrode unit 13 comprises that also one is formed on the electrode layer 138 on this p-type semiconductor layer surface, this second electrode 132 is formed on this electrode layer 138, have a center 136 and two that relatively arranges away from this first electrode 131 by this center 136 to the extension 137 that external symmetry is extended, utilize equally the electrode structural designs of holohedral symmetry formula, motor current is injected into the dispersed homogeneous degree of this action film, and promotes the brightness of LED.

Because electrode is first junction that LED element when action electric current injects the action film, therefore, the structural design of improved electrode how, the uniformity that motor current injects to promote the luminous efficiency of LED element, is the directions that those skilled in the art constantly improve always.

Summary of the invention

The purpose of this invention is to provide a kind of high brightness LED.

High brightness LED of the present invention comprises a base material, action film and an electrode unit.

This action film comprise a bottom that is connected with this base material and from this bottom upwardly extending section, this bottom has the zone line that an open area that extends along a first direction, extends to this first direction from this open area and is positioned at this open area and a first area of zone line two opposite sides and a second area, this one from this zone line and this first area, this second area upwards forms, and this first area, this second area along perpendicular to the width ratio of this first direction between 0.6 to 0.95.

This electrode unit has second electrode of the first electrode and on this end face that is arranged on this open area, this second electrode has one first electrode block, one second electrode block and one connects this first electrode block, the linkage section of this second electrode block, this first electrode block, this second electrode block is separately positioned on this first area, this second area, and this linkage section is across this zone line and connect respectively this first electrode block, this second electrode block, this first electrode, this second electrode is fitted to each other provides electric energy to move film to this, makes this action film convert the electric energy of accepting to luminous energy backward outer sending with photoelectric effect.

Light-emitting diode of the present invention, this bottom is rectangle, and this open area is extended to another long side direction by a long limit of this bottom.

Light-emitting diode of the present invention, this linkage section is curved, and in all straight lines in the center of circle by this linkage section, and the line segment length between the edge of this linkage section and this open area is identical.

Light-emitting diode of the present invention, definition one is parallel with this first direction and pass through first straight line at this open area center, wherein, this first straight line and this zone line near this first electrode while meeting at one first intersection point, meeting at one the 4th intersection point, meet at one second intersection point with this linkage section near this first intersection point with another opposite side, and meeting at one the 3rd intersection point with this linkage section near one side of the 4th intersection point, the ratio of this first intersection point to the distance of this second intersection point and the 3rd intersection point to the distance of the 4th intersection point is between 1.5 to 4.0.

Light-emitting diode of the present invention, this first intersection point arrive the ratio of the distance of this second intersection point and the distance that the 3rd intersection point arrives the 4th intersection point between 2.0 to 3.5.

Beneficial effect of the present invention is: utilize specific first area, second area edge perpendicular to the width ratio setting of this first direction and the design of the second electrode, allow electric current when injecting this action film, be able to even diffusion profile, and then effectively promote the luminous efficiency of light-emitting diode.

Description of drawings

Fig. 1 is a schematic diagram, and present horizontal light emitting diode structure is described;

Fig. 2 is a cutaway view, aid illustration Fig. 1;

Fig. 3 is a schematic diagram, and another aspect of present horizontal light emitting diode structure is described;

Fig. 4 is a cutaway view, aid illustration Fig. 3;

Fig. 5 is a schematic diagram, and the another aspect of present horizontal light emitting diode structure is described;

Fig. 6 is a cutaway view, aid illustration Fig. 5;

Fig. 7 is a schematic diagram, and the light emitting diode construction of preferred embodiment of the present invention is described;

Fig. 8 is a cutaway view of getting along the straight line 8-8 among Fig. 7;

Fig. 9 is the curve chart of different a, b ratio and brightness relationship of this preferred embodiment of explanation the present invention;

Figure 10 is explanation this preferred embodiment of the present invention and the area of comparative example and the curve chart of brightness relationship;

Figure 11 is the curve chart of different c, d ratio and brightness relationship of this preferred embodiment of explanation the present invention.

Embodiment

The present invention is described in detail below in conjunction with drawings and Examples.

Consult Fig. 7, Fig. 8, Fig. 8 is the cutaway view that is selected from 8-8 line among Fig. 7, one preferred embodiment of high brightness LED of the present invention comprises that a base material 2, is formed at action film 3 and the electrode unit 4 on this base material, this electrode unit 4 can cooperate provides electric energy to this action film 3, this action film 3 can photoelectric effect after accepting electric energy convert electric energy to behind the luminous energy to outside send.

This base material 2 is made of insulating material, because the constituent material of this base material 2 is well known to those skilled in the art, therefore, no longer add to give unnecessary details at this, this base material 2 is rectangle and is made of by material sapphire in the present embodiment, and to define a long side direction perpendicular to this base material 2 be first direction y.

This action film 3 comprises that in kenel a bottom 31 that is connected with this base material 2 and is from 31 upwardly extending sections in this bottom 32, this bottom 31 has an open area 311 along this first direction y extension, one zone line 312 that extends to this first direction y from this open area 311 and be positioned at a first area 313 and a second area 314 of this open area 311 and zone line 312 two opposite sides, this one 32 is from this zone line 312 and first area 313, second area 314 upwards forms, this first area 313, this second area 314 is respectively a along the width perpendicular to this first direction y, b, and the ratio of a and b (a/b) is between 0.6 to 0.95.

In the present embodiment, 31 pairs of this bottoms should be rectangle by base material 2, and this open area 311 generally is the extension of half arc by a wherein long limit of this bottom 31 to another long side direction.

Specifically, this action film 3 sequentially forms a n-type semiconductor layer and a p-type semiconductor layer at this base material 2 with extensional mode first, then being etched down to this n-type semiconductor layer with lithographic process by this p-type semiconductor layer end face again exposes, and have on the formation structure that a n-type semiconductor layer and that is connected with this base material 2 is connected on this n-type semiconductor layer and form the p-type semiconductor layer of p-n junction (p-n junction) with this n-type semiconductor layer, when providing electrical energy flows to pass through this action film 3, the p-n junction that forms in this p-type semiconductor layer and this N-shaped semiconductor layer produces electron-hole recombinations and produces light.

This n-type semiconductor layer, the constituent material of this p-type semiconductor layer, can be selected from respectively the III-V family semi-conducting material that comprises that III-V family semi-conducting material that the n-type mixes and p-type mix, because the production method of this action film 3 and the selection of related semiconductor material are well known to those skilled in the art and are non-is emphasis of the present invention, therefore, no longer add to describe in detail at this, in the present embodiment, this n-type semiconductor layer is selected from gallium nitride based (GaN-based) semi-conducting material that the n-type mixes, and this p-type semiconductor layer is selected from gallium nitride based (GaN-based) semi-conducting material that the p-type mixes.

In addition, be noted that, this action film 3 also visual actual leds demand and different stacking rete structures are arranged, for example this action film 3 can comprise also that one is formed on the conductive layer on this p-type semiconductor layer, can help electric current evenly to spread, with the luminous efficiency of this action film of further lifting, because the material of described film layer structure with difference in functionality and manufacture method are well known to those skilled in the art and non-ly are emphasis of the present invention, therefore, no longer add to describe in detail at this.

This electrode unit 4, having one is arranged on this open area 311 and is formed on these 32 end faces and is the second electrode 42 of ohmic contact with this one 32 with the first electrode 41 and that this open area 311 is ohmic contact (Ohmic contact), this second electrode 42 has one first electrode block 421, one second electrode block 422 and one connects this first electrode block 421, the linkage section 423 of this second electrode block 422, in the present embodiment, this the first electrode 41 is formed on the middle position of this open area 311, this first electrode block 421, this second electrode block 422 is separately positioned on this first area 313, on this second area 314, this linkage section 423 is arcuation across this zone line 312 and connects this first electrode block 421, this second electrode block 422.

It is worth mentioning that, the present invention can be again by the distance proportion of this linkage section 423 of control with these zone line 312 relative both sides, and can further promote again the luminous efficiency of this light-emitting diode.

This linkage section 423 is the arcuation extension and links this first electrode block 421 in the present embodiment, this second electrode block 422, and identical apart from essence with these open area 311 edges, that is to say, in all straight lines in the center of circle of passing through this linkage section 423, line segment length between the edge of this linkage section 423 and this open area 311 is identical, definition one is parallel with this first direction y and pass through the first straight line L at these open area 311 centers, this the first straight line L and this zone line 312 meet at one first intersection point 01 near one side of this first electrode 41, meet at one the 4th intersection point 04 with another opposite side, and meet at one second intersection point 02 with this linkage section 423 near one side of this first intersection points 01, and meet at one the 3rd intersection point 03 with this linkage section 423 near one side of the 4th intersection points 04, this first intersection point 01 is c to the distance of this second intersection point 02, the distance of the 3rd intersection point 03 to the 4th intersection point 04 is d, and the ratio of c and d (c/d) is between 1.5 to 4.0.

This first electrode 41, this second electrode 42 are selected from metal material, for example gold, aluminium, palladium, titanium, platinum or wherein a combination consist of, this first electrode 41, this second electrode 42 all are selected from titanium and are consisted of by material in the present embodiment, this first electrode 41, this second electrode 42 are fitted to each other provides electric energy to this action film 3, and this action film 3 converts electric energy to luminous energy and outwards sends after receiving electric energy.

Consult Fig. 9, Fig. 9 is that the c/d ratio with the light-emitting diode of this preferred embodiment of the present invention is fixed as 3, and the brightness curve figure that the different a/b ratio of measurement shows under fixing conducting voltage, in the time of as shown in Figure 9 between a/b ratio is controlled at 0.6 to 0.95, the brightness that shows is more than 7.0mW, the brightness that shows when preferably, this a/b ratio is between 0.65 to 0.9 more can be promoted to more than the 7.1mW.Under 20mA, to record and take mW as unit about the explanatory note " brightness (mW@20mA) " of ordinate expression brightness among Fig. 9.

Consult table 1, table 1 is that (a/b ratio is fixed as 0.71 with the light-emitting diode of this preferred embodiment of the present invention, c/d ratio is fixed as 3) with comparative example 1 and comparative example 2 respectively when the different chips dimensioned area, luminous efficiency result under identical conducting voltage, this comparative example 1 is light emitting diode construction shown in Figure 3, and this comparative example 2 is light emitting diode construction shown in Figure 5.

Table 1

In addition, consult Figure 10, Figure 10 is light-emitting diode area that the result of table 1 is drawn out and the graph of relation of luminosity, and rhombus (◆) represents this preferred embodiment among the figure, triangle (▲) represents this comparative example 1, and square (■) represents this comparative example 2.

By the result of Figure 10 as can be known, this preferred embodiment of the present invention is to be different from existing asymmetric electrode structural designs, electrode is arranged on the position with specific a/b ratio, electric current is injected reach better diffusion effect, therefore compare with this comparative example 1 and comparative example 2, under equal area, this preferred embodiment of the present invention can have the highest luminous efficiency, and can within the shortest time, i.e. reaction reach required brightness, be that this light-emitting diode of the present invention can reach the luminosity identical with existing light-emitting diode by less area, and can further reach the reduction cost, dwindle another purpose of component size.

It is worth mentioning that, by experimental result learn when further regulate and control this first intersection point to the distance c of this second intersection point and the 3rd intersection point to the 4th intersection point apart from the ratio the d (c/d) between 1.5 to 4.0 the time, uniformity when further motor current injects, and can further promote the luminous efficiency of this action film.

Consult Figure 11, Figure 11 is that the present embodiment is under 0.71 the condition at a/b ratio, the brightness curve that different c/d ratio shows, by Figure 11 result as can be known, in the time of between c/d ratio is controlled at 1.5 to 4, but the brightness of this light-emitting diode all essence reaches approximately 7.1mW, and preferably, but the equal essence of the brightness of this light-emitting diode reaches approximately 7.2mW when c/d ratio is controlled between 2 to 3.5.

By above explanation as can be known, the present invention is by controlling this first electrode, this second electrode in the relative position setting of this action film, more equably diffusion in the time of can allowing electric current pass through this first electrode, this second electrode injection to this action film, make the luminous efficiency of this light-emitting diode of the present invention promote, and can promote brightness, therefore can reach the luminosity identical with having light-emitting diode now by less area, and further reach the reduction cost, dwindle another purpose of component size.

Claims

1. light-emitting diode, comprise: a base material, one action film and an electrode unit, it is characterized in that, this action film comprise a bottom that is connected with this base material and from this bottom upwardly extending section, this bottom has an open area along first direction extension, one zone line that extends to this first direction from this open area and be positioned at this open area and a first area of this zone line two opposite sides and a second area, this one is from this zone line and this first area, this second area upwards forms, and this first area, this second area along perpendicular to the width ratio of this first direction between 0.6 to 0.95, this electrode unit has the second electrode that first electrode and that is arranged on this open area is arranged on this end face, this second electrode has one first electrode block, one second electrode block and one connects this first electrode block, the linkage section of this second electrode block, this first electrode block, this second electrode block is separately positioned on this first area, this second area, and this linkage section is across this zone line and connect respectively this first electrode block, this second electrode block, this first electrode, this second electrode is fitted to each other provides electric energy to move film to this, makes this action film convert the electric energy of accepting to luminous energy backward outer sending with photoelectric effect;

Wherein, this linkage section is curved, and in all straight lines in the center of circle by this linkage section, and the line segment length between the edge of this linkage section and this open area is identical;

Definition one is parallel with this first direction and pass through first straight line at this open area center, wherein, this first straight line and this zone line near this first electrode while meeting at one first intersection point, meeting at one the 4th intersection point, meet at one second intersection point with this linkage section near this first intersection point with another opposite side, and meeting at one the 3rd intersection point with this linkage section near one side of the 4th intersection point, the ratio of this first intersection point to the distance of this second intersection point and the 3rd intersection point to the distance of the 4th intersection point is between 1.5 to 4.0.

2. light-emitting diode according to claim 1 is characterized in that, this bottom is rectangle, and this open area is extended to another long side direction by a long limit of this bottom.

3. light-emitting diode according to claim 1 is characterized in that, this first intersection point arrives the ratio of the distance of this second intersection point and the distance that the 3rd intersection point arrives the 4th intersection point between 2.0 to 3.5.