TWM500999U - LED illuminating device - Google Patents

Description

Light-emitting diode and its lighting device

The present invention relates to a light-emitting element, and more particularly to a light-emitting diode (LED) and a lighting device thereof.

In recent years, based on the evolution of technology, LED applications have become more widespread. In response to the upgrade of LEDs, the demand for LEDs in the lighting market is not only increasing; in addition, the development of high-power LEDs has been born. As far as the design of high-power LEDs is concerned, most of the current common technologies are mainly large-sized single low-voltage current LEDs, and the main methods can be divided into traditional horizontal conduction structures and vertical conduction structures. However, the operational modes of the aforementioned high power LEDs are typically operated at high currents. Therefore, once the micro-unbalanced P and N electrodes are designed, it is easy to cause current crowding which is not desired in the technical field, which not only fails to achieve the brightness required for the design, but also damages the reliability of the LED. degree. Based on the aforementioned problems, the industry has further developed high voltage light emitting diodes (HV LEDs).

Referring to Fig. 1, a conventional high voltage light-emitting diode 1 is mainly used as a lighting device. The conventional high-voltage light-emitting diode 1 comprises: a sapphire substrate 11, a plurality of micro-grains 12 disposed on the sapphire substrate 11 spaced apart from each other, an insulating protective layer 13, and a plurality of adjacent micro-grains 12 metal conductive layer 14. Each micro-die 12 includes an N-type gallium nitride (n-GaN) layer 121 formed with a terrace, and a cover a multi-quantum well layer (MQW) 122 not covering the platform, a P-type gallium nitride layer 123 covering the multiple quantum well layer 122, and a P-type layer disposed on the N-type gallium nitride layer 121 a transparent conductive layer 124 of the gallium nitride layer 123, an N-type electrode layer 125 disposed on the platform of the N-type gallium nitride layer 121 to electrically connect the N-type gallium nitride layer 121, and a transparent conductive layer disposed thereon A P-type electrode layer 126 of the P-type gallium nitride layer 123 is electrically connected to the layer 124. The insulating protective layer 13 covers the micro-grains 12 such that the N-type electrode layer 125 and the P-type electrode layer 126 of each of the micro-grains 12 are exposed. The metal conductive layers 14 are respectively connected to the P-type electrode layer 126 and the N-type electrode layer 125 on each of the two adjacent micro-grains 12, so that the micro-grains 12 are electrically connected in series.

It should be specially noted here that when the conventional high-voltage light-emitting diode 1 is used as a lighting device, it usually operates at a maximum limit of the forward current, about 35-40 mA, etc. The micro-grains 12 after being connected in series to each other will thus accumulate a large amount of thermal energy. Therefore, when the conventional high-voltage light-emitting diode 1 is used as a lighting device, the heat energy accumulated from the micro-grains 12 becomes a critical problem to be solved.

However, since the sapphire substrate 11 has a low thermal conductivity, the heat dissipation effect is poor, and the luminous efficiency of the conventional high-voltage light-emitting diode 1 is lowered. On the other hand, since the micro-grains 12 are all electrically connected in series, if any of the micro-grains 12 fails, the conventional high-voltage light-emitting diode 1 is in an open state and thus cannot emit light. That is, as the number of microcrystals 12 connected in series increases, the failure rate of the conventional high voltage light-emitting diode 1 also increases.

According to the above description, it is known that the light-emitting diode is used as illumination. The heat dissipation problem derived from the device to improve the luminous efficiency when applied to the illumination device and at the same time reduce the failure rate of the light-emitting diode is a difficult problem to be solved by those skilled in the technical field.

Therefore, the object of the present invention is to provide a light-emitting diode.

Another object of the present invention is to provide a light-emitting diode lighting device.

Therefore, the novel light-emitting diode comprises: a thermal conductive circuit board, and a light-emitting unit. The light emitting unit includes an epitaxial substrate and at least two light emitting grains. The illuminating dies are adjacent to each other and spaced apart from each other, and each of the illuminating dies includes a first type semiconductor layer disposed on the epitaxial substrate and having a platform and a stud adjacent to the platform, and a setting An active layer on the platform, and a second type semiconductor layer disposed on the active layer and not in contact with the stud of the first type semiconductor layer. A top surface of one of the second type semiconductor layers of each of the light emitting grains is substantially equal in height to a top surface of the stud of the first type semiconductor layer. In the present invention, the platforms of the first type semiconductor layers of the adjacent illuminating dies are on the same side, and the pillars of the first type semiconductor layers of the adjacent illuminating dies are on the same side; The top surface of the pillar of the first type semiconductor layer and the top surface of the second type semiconductor layer are respectively attached to the thermal conductive circuit board to form an electrical connection with the thermal conductive circuit board, and the thermal conductive circuit The plates form a parallel circuit.

In addition, the novel light-emitting diode lighting device comprises: a thermal conductive circuit board, and a plurality of light-emitting units. Each light unit includes a bar The crystal substrate and at least two luminescent crystal grains. The illuminating dies of each of the illuminating units are spaced apart from each other, and each of the illuminating dies includes a first type semiconductor layer disposed on the epitaxial substrate and having a land and a stud adjacent to the platform. An active layer disposed on the platform, and a second type semiconductor layer disposed on the active layer and not in contact with the stud of the first type semiconductor layer. The top surface of one of the second type semiconductor layers of each of the light-emitting dies of each of the light-emitting units is substantially equal to a top surface of the stud of the first-type semiconductor layer. In the present invention, the platforms of the first type semiconductor layers of the adjacent illuminating dies of the respective illuminating units are located on the same side, and the studs of the first type semiconductor layers of the adjacent illuminating dies are located on the same side; The top surface of the pillar of the first type semiconductor layer and the top surface of the second type semiconductor layer are respectively attached to the thermal conductive circuit board to form an electrical connection with the thermal conductive circuit board, and by The thermally conductive circuit board has two adjacent light emitting dies in series with each other to form a series circuit, and the light emitting dies of the respective light emitting units form a parallel circuit by the thermally conductive circuit board.

The effect of the novel is that the top surface of the second type semiconductor layer of each of the light-emitting dies is substantially higher than the top surface of the pillars of the first-type semiconductor layer, thereby facilitating the light-emitting diode through the flip chip process (flip) The chip process is used to solve the heat dissipation problem. In addition, the failure rate of the light-emitting diode illumination device can be reduced by the parallel circuit formed by the light-emitting dies of the respective light-emitting units transmitting through the thermally conductive circuit board.

2‧‧‧ Thermally conductive circuit board

20‧‧‧ surface

21‧‧‧Contacts

22‧‧‧Wire

23‧‧‧First external node

24‧‧‧Second external node

3‧‧‧Lighting unit

31‧‧‧ epitaxial substrate

32‧‧‧Lighting grain

321‧‧‧First type semiconductor layer

322‧‧‧ platform

323‧‧‧Bump

324‧‧‧ active layer

325‧‧‧Second type semiconductor layer

33‧‧‧Insulators

4‧‧‧DC power supply

X‧‧‧ first direction

Y‧‧‧second direction

Other features and effects of the present invention will be apparent from the following description of the drawings, in which: 1 is a partial cross-sectional view showing a conventional high-voltage light-emitting diode; FIG. 2 is a top plan view showing an embodiment of the novel light-emitting diode; FIG. 3 is a front elevational view showing the light-emitting diode of the present invention FIG. 4 is an equivalent circuit diagram illustrating the light-emitting diode of the present embodiment. The light-emitting unit is connected to the DC power supply after the power supply unit is connected to the light-emitting unit. The two illuminating crystal grains form a parallel circuit; FIG. 5 is a top view showing an embodiment of the novel illuminating diode illuminating device; FIG. 6 is a front cross-sectional view taken along line VI-VI of FIG. The novel light-emitting diode lighting device has a detailed connection relationship between the plurality of light-emitting units of the embodiment and a heat-conductive circuit board; and FIG. 7 is an equivalent circuit diagram illustrating the light-emitting diode lighting device of the present invention. The plurality of light-emitting dies of each of the light-emitting units are connected in parallel, and each two adjacent light-emitting units are connected in series.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to Figures 2, 3 and 4, an embodiment of the novel light-emitting diode is electrically connected to the two poles of the DC power supply 4. The embodiment of the novel light-emitting diode comprises: a thermal conductive circuit board 2, and a hair Light unit 3.

As shown in FIGS. 2 and 3, the thermally conductive circuit board 2 has two contacts 21. The contacts 21 are disposed on a surface 20 of the thermally conductive circuit board 2 along a first direction X, and the contacts 21 are electrically connected to the DC power source as shown in FIG. The two poles of the supply 4.

The illuminating unit 3 includes an epitaxial substrate 31, at least two illuminating dies 32 adjacent to each other and spaced apart along a second direction Y substantially perpendicular to the first direction X, and at least one of the two adjacent The insulator 33 between the light crystal grains 32. In the embodiment of the light-emitting diode of the present invention, the number of the light-emitting dies 32 is exemplified by two examples. The number of the insulators 33 is exemplified by one.

As shown in FIG. 3, each of the illuminating dies 32 includes a first type semiconductor layer 321 disposed on the epitaxial substrate 31 and having a land 322 and a stud 323 adjacent to the platform 322. An active layer 324 on the platform 322 and a second type semiconductor layer 325 disposed on the active layer 324 and not in contact with the studs 323 of the first type semiconductor layer 321 . A top surface of the second type semiconductor layer 325 is substantially equal in height to a top surface of the stud 323 of the first type semiconductor layer 321 . Preferably, the height of the stud 323 of the first type semiconductor layer 321 of each of the illuminating crystal grains 32 is between 100 μm and 120 μm, and the height of the land 322 of the first type semiconductor layer 321 is between 55 μm and 65 μm. between.

In addition, the roughened surface of the land 322 of the first type semiconductor layer 321 of each of the light-emitting dies 32 is intended to improve luminous efficiency. However, when this embodiment of the light-emitting diode of the present invention is applied to ordinary brightness When the device is illuminated, the roughened surface can be omitted.

Referring to FIG. 2 and FIG. 3, the platform 322 of the first type semiconductor layer 321 of the adjacent illuminating crystal grains 32 is located on the same side, and the pillars 323 of the first type semiconductor layer 321 of the adjacent illuminating crystal grains 32 are 323. Located on the same side. In addition, the light-emitting unit 3 of the embodiment of the light-emitting diode of the present invention is a pillar 323 of the first-type semiconductor layer 321 of each of the light-emitting crystal grains 32 after being turned over by 180° in the state shown in FIG. The top surface and the top surface of the second type semiconductor layer 325 are respectively attached to the contacts 21 on the surface of the thermally conductive circuit board 2 to form an electrical connection with the thermally conductive circuit board 2, and the thermal conductivity is The contacts 21 of the circuit board 2 are such that the light-emitting dies 32 form a parallel circuit as shown in FIG.

Referring to FIG. 5, FIG. 6, and FIG. 7, an embodiment of the novel light-emitting diode lighting device is substantially the same as the embodiment of the novel light-emitting diode, and the difference is that the thermal conductive circuit board 2 There is also a wire 22, a first external node 23, and a second external node 24, and the number of contacts 21 on the surface 20 of the thermally conductive circuit board 2 is different from that of the embodiment of the light emitting diode. The number of the light-emitting units 3 is a plurality of the embodiments of the light-emitting diode lighting device of the present invention. The number of the light-emitting units 3 is illustrated by four examples. The number of the contacts 21 is Take five examples as an example.

As shown in FIG. 5 and FIG. 6, the contacts 21 of the thermally conductive circuit board 2 are sequentially disposed on the surface 20 along the first direction X, and the wire 22 is connected to the rightmost contact. 21 and then reverse the surface 20 to the inside of the thermally conductive circuit board 2, and opposite to the first side After extending to X adjacent to the leftmost contact 21, the second external node 24 is connected to extend toward the surface 20, and the first external node 23 is connected to the leftmost contact 21. The two poles of the DC power supply 4 are electrically connected to the first external node 23 and the second external node 24, respectively. In addition, the light-emitting units 2 are disposed on the conductive circuit board 2 along the first direction X.

Similarly, as shown in FIG. 5, the platforms 322 of the first type semiconductor layers 321 of the adjacent light-emitting dies 32 of the respective light-emitting units 3 are located on the same side (on the left side of each of the light-emitting dies 32), and The top surface of the stud 323 of the first type semiconductor layer 321 of the adjacent illuminating crystal grains 32 is located on the same side (on the right side of each of the illuminating crystal grains 32). The top surface of the stud 323 of the first type semiconductor 321 of each of the illuminating crystal grains 32 and the top surface of the second type semiconductor layer 325 are respectively attached to each of the two adjacent contacts 21 to form electricity with the thermally conductive circuit board 2. connection. In addition, each of the two adjacent light-emitting units 3 shares a contact 21 to connect each two adjacent light-emitting units 3 in series with each other by the thermally conductive circuit board 2 to form a series circuit as shown in FIG. Moreover, the light-emitting dies 32 of the light-emitting units 3 form a parallel circuit as shown in FIG. 7 by the contacts 21 of the heat-conductive circuit board 2.

According to the description of the last two paragraphs, when one of the single light-emitting diodes 3 of the novel light-emitting diode lighting device fails, the direct current power supplied by the DC power supply 4 can automatically select the two light-emitting lights. The other of the crystal grains 32 is bypassed to sequentially transmit DC power to the light-emitting dies 32 of each of the light-emitting units 3 through the contacts 21 .

In addition, it should be further noted here that when the number of the light-emitting dies 32 on each of the light-emitting units 3 is increased from two to three or even four, the overall circuit can be reduced by the illuminating crystal of any of the light-emitting units 3. The probability that the pellet 32 is faulty and presents an open state. More specifically, if the failure rate of the single luminescent die 32 is 0.5; then, the failure rate of the illuminating unit 3 having the two illuminating dies 32 is 0.25, and the illuminating unit 3 having the three illuminating dies 32 The failure rate is reduced to 0.125. Therefore, the number of the light-emitting dies 32 on each of the light-emitting units 3 of the light-emitting diode lighting device of the present invention is not limited to two. In order to further reduce the failure rate of the light-emitting diode lighting device, the number of the light-emitting dies 32 of each of the light-emitting units 3 may be increased according to design.

In this embodiment of the light-emitting diode of the present invention, the light-emitting unit 3 passes through the top surface of the pillar 323 of the first-type semiconductor layer 321 of each of the light-emitting dies 32 substantially higher than the top surface of the second-type semiconductor layer 325. Designed to facilitate the implementation of flip chip processing to solve heat dissipation problems. More importantly, this embodiment of the light-emitting diode illuminating device of the present invention simultaneously cooperates with the structural configuration of the illuminating crystal grains 32 of each of the illuminating units 3 (that is, as shown in FIG. 5, the adjacent illuminating crystals The platform 322 of the first type semiconductor layer 321 of the granules 32 is located on the same side, and the pillars 323 of the first type semiconductor layer 321 of the adjacent illuminating crystal grains 32 are located on the same side, so that the illuminating of each of the illuminating units 3 The die 32 can directly directly connect the top surface of the pillar 323 of the first type semiconductor layer 321 and the top surface of the second type semiconductor layer 325 to the contacts 21 of the thermally conductive circuit board 2, so that The light-emitting dies 32 are electrically connected in parallel to each other through the thermally conductive circuit board 2, thereby reducing the failure rate of the overall circuit.

In summary, the illuminating diode of the present invention and the illuminating device thereof are substantially higher than the top surface of the stud 323 of each of the first type semiconductor layers 321 by the top surface of the second type semiconductor layer 325 of each embodiment. The design is advantageous for the light-emitting diode to pass through the flip chip process to solve the heat dissipation problem; on the other hand, the first type semiconductor layer 321 of the light-emitting die 32 of each of the light-emitting units 3 is located on the platform 322 and the pillar 323 The configuration of the same side can make the adjacent light-emitting dies 32 of the light-emitting units 3 directly communicate with each other through the contacts 21 of the thermal conductive circuit board 2 to reduce the failure rate of the illuminating device. The purpose of the new type.

However, the above description is only for the embodiments of the present invention, and the scope of the present invention cannot be limited thereto, that is, the simple equivalent changes and modifications made by the present patent application scope and the contents of the patent specification are still It is within the scope of this new patent.

2‧‧‧ Thermally conductive circuit board

20‧‧‧ surface

21‧‧‧Contacts

3‧‧‧Lighting unit

31‧‧‧ epitaxial substrate

32‧‧‧Lighting grain

323‧‧‧Bump

325‧‧‧Second type semiconductor layer

33‧‧‧Insulators

X‧‧‧ first direction

Y‧‧‧second direction

Claims (8)

A light emitting diode comprising: a thermal conductive circuit board; and a light emitting unit comprising an epitaxial substrate and at least two light emitting crystal grains, the light emitting crystal grains are adjacent to each other and spaced apart, and each of the light emitting crystal grains comprises a first type semiconductor layer is disposed on the epitaxial substrate, and has a platform and a protrusion adjacent to the platform, an active layer disposed on the platform, and a second type semiconductor layer. Provided on the active layer and not in contact with the stud of the first type semiconductor layer, a top surface of the second type semiconductor layer is substantially equal to a top surface of the stud of the first type semiconductor layer; The platforms of the first type semiconductor layers of the adjacent illuminating dies are located on the same side, and the pillars of the first type semiconductor layers of the adjacent illuminating dies are on the same side; and wherein the illuminating dies are The top surface of the pillar of the semiconductor layer and the top surface of the second semiconductor layer are respectively attached to the thermal conductive circuit board to form an electrical connection with the thermal conductive circuit board, and the thermal conductive circuit board A parallel circuit is formed. The illuminating diode of claim 1, wherein the illuminating unit further comprises at least one insulator, the insulator being filled between the two adjacent illuminating dies. The light-emitting diode according to claim 1, wherein each of the light-emitting crystal grains The platform has a roughened surface. The light-emitting diode of claim 1, wherein a height of the pillar of the first-type semiconductor layer of each of the light-emitting dies is between 100 μm and 120 μm, and a height of the platform of the first-type semiconductor layer is Between 55μm and 65μm. A light-emitting diode lighting device comprising: a thermal conductive circuit board; and a plurality of light-emitting units, each light-emitting unit comprising an epitaxial substrate and at least two light-emitting crystal grains, wherein the light-emitting crystal grains of each light-emitting unit are arranged at intervals And each of the illuminating dies includes: a first type semiconductor layer disposed on the epitaxial substrate, and having a platform and a protrusion adjacent to the platform, an active layer disposed on the platform, and a a second type semiconductor layer disposed on the active layer and not in contact with the stud of the first type semiconductor layer, a top surface of the second type semiconductor layer and a top surface of the stud of the first type semiconductor layer Is a substantially equal height; wherein the platforms of the first type semiconductor layers of the adjacent illuminating dies of the respective illuminating units are on the same side, and the studs of the first type semiconductor layers of the adjacent illuminating dies are on the same side Wherein the top surface of the pillar of the first type semiconductor layer of each of the light-emitting dies and the top surface of the second type semiconductor layer are respectively attached to the thermal conductive circuit board to form an electrical connection with the thermally conductive circuit board. And the thermal conductivity of the circuit board Two adjacent light emitting cells connected in series to each other A series circuit is formed, and the light-emitting dies of the respective light-emitting units form a parallel circuit by the thermally conductive circuit board. The illuminating diode lighting device of claim 5, wherein each of the illuminating units further comprises at least one insulator, the insulator being filled between the two adjacent illuminating dies. The illuminating diode lighting device of claim 5, wherein the platform of each of the first type semiconductor layers has a roughened surface. The illuminating diode lighting device of claim 5, wherein the height of the studs of each of the first type semiconductor layers is between 100 μm and 120 μm, and the height of the platform of each of the first type semiconductor layers is 55 μm. To 65μm.