CN201259895Y - Rotary GaN based LED chip electrode - Google Patents

Abstract

The utility model relates to a rotary GaN based LED chip electrode and belongs to the technical field of LED chips; the rotary GaN based LED chip electrode has main characteristics that: a P-shaped strip electrode and an N-shaped strip electrode which are parallel are distributed between a P-shaped welding disc of the P-shaped strip electrode and an N-shaped welding disc of the N-shaped strip electrode; the N-shaped electrode further comprises a clockwise rotary strip electrode and an anti-clockwise rotary strip electrode, and the clockwise P-shaped strip electrode is distributed between the two rotary strip electrodes, and each strip electrode is parallel to the edge of the chip; combined the advantages of ring-shaped electrodes and the strip electrodes, the P-shaped electrode and the N-shaped electrode are intersected with each other and arrayed in parallel, the transmission distance of the current is not only shortened, and the distances of the P-shaped electrode and the N-shaped electrode are equal, therefore, the uniformity of the current distribution is increased, combined efficiency of a current carrier is improved, and light extraction is increased, the loss for converting into the internal heat energy is reduced, the light-emitting efficiency of the chip is improved and the electrooptical characteristic of the chip is improved.

Description

Rotation shape GaN base LED chip electrode

Technical field

This use is novel to relate to a kind of rotation shape GaN base LED chip electrode, and it is uneven and promote the photoelectric characteristic of chip to help improving chip cooling, belongs to the led chip technical field.

Background technology

LED with himself have the luminous efficiency height, plurality of advantages such as power consumption is little, the life-span is long, caloric value is low, volume is little, environmental protection and energy saving, oneself has application market widely, as fields such as automobile, backlight, traffic lights, large scale display, military affairs.And along with the continuous development of semiconductor and material technology with ripe, LED be expected to become novel the 4th generation the solid-state illumination light source.And GaN and compound thereof are third generation semiconductor material important after Ge, Si and GaAs, InP, be acknowledged as significant achievement in the photoelectron scientific and technological progress based on the development of GaN base LED, and be the key light source of development solid-state illumination, the human illumination of realization revolution, be with a wide range of applications.

At present the epitaxial wafer that adopts in actual production of GaN base LED mainly is to be substrate with the sapphire, and sapphire is an insulator, so, must form negative electrode by the etched features surface.There is the extending transversely of electric current inevitably in the LED that is made into this technology, thereby very easily produces current gathering effect, and this will cause, and LED is luminous, heating is inhomogeneous, degradation problem under useful life.Especially for high-power LED, because its size is bigger, current gathering effect is more obvious.Therefore, optimize the electrode shape of GaN base LED, can reduce current gathering effect, improve current expansion and distribute, make its CURRENT DISTRIBUTION more even, reduce the series resistance of device, and then the generation of minimizing Joule heat, the photoelectric properties that improve GaN base LED are had important function.

Xiamen University provides a kind of P, N electrode of tree leaf vein-shaped high power gallium nitride LED chip in the application for a patent for invention of publication number for CN1870313, it is at the superficial growth layer of transparent conductive layer of P type GaN, deposit P type electrode on transparency conducting layer, deposit N type electrode in groove, N type electrode is scattered in the shape of tree leaf vein along the diagonal of chip, also comprise two vertical with it parallel N type electrodes, P type electrode retaining collar is around the edge of chip, and have feeler to stretch out, be clipped between two parallel N type electrodes.This electrode is relatively even perpendicular to the CURRENT DISTRIBUTION between diagonal and N type electrode N2 that is parallel to each other and the N3, but poor in the uniformity of all the other regional CURRENT DISTRIBUTION.Because it is bigger in diagonal and the N type electrode N2 that is parallel to each other and N3 to the P type distance between electrodes difference that is looped around the chip square edge in all the other regions perpendicular, CURRENT DISTRIBUTION is very inhomogeneous, and this area size accounts for 1/2nd of chip, illustrates that the P of this tree leaf vein-shaped high power gallium nitride LED chip, the current expansion characteristic of N electrode still are not ideal enough.

Summary of the invention

The purpose of this utility model provides a kind of rotation shape GaN base LED chip electrode, purpose is to overcome that above-mentioned tree leaf vein-shaped high power gallium nitride LED chip still exists is bigger to the P type distance between electrodes difference that is looped around the chip square edge perpendicular to diagonal and the N type electrode N2 that is parallel to each other and N3, CURRENT DISTRIBUTION is very inhomogeneous, the current expansion characteristic still is dissatisfactory deficiency, realization helps improving the uniformity of CURRENT DISTRIBUTION, increase the light extraction efficiency of chip, improve the unequal problem of heat radiation of chip, thereby promote the photoelectric characteristic of chip.

The purpose of this utility model is achieved through the following technical solutions, a kind of rotation shape GaN base LED chip electrode, comprise P type electrode and N type electrode, the GaN epitaxial wafer is carried out mesa etch, form P type GaN table top and N type GaN groove, in P type GaN superficial growth layer of conductive film, deposit P type electrode on conductive film again, perhaps directly at P type GaN surface deposition P type electrode, deposit N type electrode in groove, it is characterized in that, the P type and the N type strip electrode that between the pad of P type and N type electrode, are distributing and be parallel to each other, N type electrode also comprise clockwise and counterclockwise to two rotation shape strip electrodes, the P type strip electrodes of the clockwise direction that between two rotation shape strip electrodes, distributing, and each strip electrode all is parallel to chip edge.

The utility model combines the advantage of annular electrode and strip electrode, P type and N type electrode intersect parallel arrangement mutually, transmission range between two electrodes equates, electric current obtains diffusion profile equably, improved the light extraction efficiency of chip, also help simultaneously to improve problems such as the current-voltage characteristic of chip and heat radiation, can promote the photoelectric properties of chip on the whole.

Description of drawings

Fig. 1 is the utility model P type, N type distribution of electrodes structural representation;

Among the figure, P represents P type electrode, N represents N type electrode, 1 expression P type GaN table top, 2 expression N type GaN grooves, N1, N2, N3, N4, N5, N6, N7, N8 represents to be parallel to the N type strip electrode of chip edge, N1 wherein, N2, the N3 representative ring around chip edge counterclockwise to rotation shape strip electrode, N4, N5, N6, N7 is illustrated in the rotary-type strip electrode of chip central authorities clockwise direction, N8 represents the strip electrode along chip edge, P1, P2, P3, P4, P5, P6 represents to be parallel to the P type strip electrode of chip edge, P1 wherein, P2, P3, P4, P5 is clipped in the strip electrode of the clockwise direction between preceding two N types rotation shape strip electrode, and P6 represents to be parallel to the strip electrode of chip edge.

Specific embodiments

Further specify the utility model in conjunction with the accompanying drawings and embodiments, as shown in Figure 1, the utility model substrate is the sapphire insulator, comprise P type electrode and N type electrode, at first GaN base epitaxial wafer is carried out mesa etch, form P type GaN table top 1 and N type GaN groove 2, again at the direct deposit P type electrode in P type GaN surface, its mainly comprise near and be parallel to the strip electrode P6 of chip edge, and be parallel to chip edge and be strip electrode P1, P2, P3, P4, P5, the P6 that clockwise direction is rotated, integral body is rotation shape and distributes, and has six strip electrodes.N type electrodeposition is in the N type GaN groove 2 slightly wideer than its width, mainly comprise and be looped around chip edge and be strip electrode N1, N2, the N3 of hour hands to rotation, be parallel to chip edge and be strip electrode N4, N5, N6, the N7 that clockwise direction is rotated in chip central authorities, and the strip electrode N8 that is positioned at chip edge, also be rotation shape on the whole and distribute, have eight strip electrodes.P type rotation electrode is between the N of two reverse rotations type electrode, two kinds of electrodes intersect mutually and are arranged in parallel, not only shorten the transmission range of electric current, and distance equates between the two, has increased the uniformity of CURRENT DISTRIBUTION, has improved the combined efficiency of charge carrier, increased the extraction of light, reduce the loss that is converted into internal heat energy, improved the light extraction efficiency of chip, improved the photoelectric characteristic of chip.The utility model also can be in P type GaN superficial growth layer of conductive film, again deposit P type electrode on conductive film; The shape of the utility model P type electrode and N type electrode is also interchangeable, and N type electrodeposition is in the groove of respective shapes; The shape of P type electrode and N type electrode also can be made mirror transformation, and N type electrodeposition is in the groove of respective shapes.

Claims (5)

1, a kind of rotation shape GaN base LED chip electrode, comprise P type electrode and N type electrode, the GaN epitaxial wafer is carried out mesa etch, form P type GaN table top and N type GaN groove, in P type GaN superficial growth layer of conductive film, deposit P type electrode on conductive film again, perhaps directly at P type GaN surface deposition P type electrode, deposit N type electrode in groove, it is characterized in that, the P type and the N type strip electrode that between the N type pad of the P type pad of P type electrode and N type electrode, are distributing and be parallel to each other, N type electrode also comprise clockwise and counterclockwise to two rotation shape strip electrodes, at two P type strip electrodes that rotate the clockwise direction that distributing between the shape strip electrode, and each strip electrode all is parallel to chip edge.

2, rotation shape GaN base LED chip electrode according to claim 1 is characterized in that described N type electrode comprises the strip electrode along chip one lateral edges from N type pad; From N type pad along chip by chip one lateral edges and be counterclockwise strip electrode to rotation; From N type pad in the chip central part, be parallel to chip edge and be the strip electrode of clockwise direction rotation.

3, rotation shape GaN base LED chip electrode according to claim 1 is characterized in that described P type electrode comprises the strip electrode that is parallel to chip one lateral edges from P type pad; From P type pad be parallel to chip by chip one side, at the strip electrode that is clockwise direction rotation N type strip electrode inboard and in parallel.

4, rotation shape GaN base LED chip electrode according to claim 1 is characterized in that the shape of P type electrode and N type electrode is also interchangeable, and N type electrodeposition is in the groove of respective shapes.

5, rotation shape GaN base LED chip electrode according to claim 1 is characterized in that the shape of P type electrode and N type electrode also can be made mirror transformation, and N type electrodeposition is in the groove of respective shapes.

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