JPS6234467Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a multicolor light emitting device, and more particularly to a mounting structure of a multicolor light emitting element having an NPPN or PNNP structure having two PN junctions having different emission colors.

FIG. 1 shows a conventional device of this type, in which numeral 1 is a multicolor light emitting device, and the device 1 includes a first N-type layer 3 made of GaP, a first P layer 3 on an N-type substrate 2 made of GaP (next to gallium),
A type layer 4, a second P type layer 5, and a second N type layer 6 are sequentially laminated by epitaxial growth.

The first N-type layer 3 contains Te (tellurium) as an impurity, and the first P-type layer 4 contains Zn (zinc) and O as impurities.
(oxygen) and has a Zn-O pair as a luminescent center. Therefore, the first PN junction 7 that emits red light is present at the boundary between the first N-type layer 3 and the first P-type layer 4.

The second P-type layer 5 contains Zn as an impurity, the second N-type layer 6 contains S (sulfur), and the second P-type layer 5 and the second P-type layer 5 contain Zn as an impurity.
Both of the 2N type layers 6 contain N (nitrogen) as a luminescent center. Therefore, a second PN junction 8 that emits green light is present at the boundary between the second P-type layer 5 and the second N-type layer 6.

Reference numeral 9 denotes a diffusion portion formed by diffusing Zn into a portion of the second N-type layer 6, and the diffusion depth of the diffusion portion 9 reaches the second P-type layer. Further, in the second N-type layer 6, the diffusion portion 9 and the non-diffusion portion are separated by a groove 10 deep enough to reach the second P-type layer 5. 11 is a first electrode formed in the non-diffusion part of the second N-type layer 6, 12 is a common electrode formed in the diffusion part 9, and 13 is a second electrode formed on the back surface of the N-type substrate 2.

14 is a conductive first and second bonding part 1;
5, 16 and a mounting portion 17 are formed on the surface of the insulating assembly substrate, and the first bonding portion 1
5. First to third leads 18 to 20 extending perpendicularly to the back side of the assembled board 14 are integrally formed on the mounting section 17 and the second bonding section 16, respectively. Further, the second electrode 13 side of the multicolor light emitting element 1 is fixed to the mounting portion 17 with a conductive adhesive or the like, and the first and second bonding portions 15 and 16 are connected to the first electrode 11 and the common electrode 13, respectively. is gold wire 21, 21
connected with.

In the above device, the first lead 18 - the third lead 20
the second PN by applying a forward bias between
Green light emission can be obtained from the junction 8, and red light emission can be obtained from the first PN junction 7 by applying a forward bias between the second lead 19 and the third lead 20. Further, by simultaneously applying a forward bias between the first lead 18 and the third lead 20 and between the second lead 19 and the third lead 20 and adjusting the applied bias, it is possible to obtain various emitted light colors from red to green. Can be done.

However, in a multicolor light-emitting element with an NPPN or PNNP structure, the P layer or N layer constituting the first and second PN junctions respectively serve as a common electrode, so in a device using such an element, both junctions are connected in antiparallel. I couldn't do it.

The present invention has been developed in view of the above problems, and will be described below based on one embodiment.

FIG. 2 shows an embodiment of the present invention, in which numeral 1 designates a multicolor light emitting element, which is the same as in FIG. 31 is a silicon diode chip, and the diode chip 31 is N
First and second P-type regions 33a and 33b are formed by diffusing impurities from the surface of a molded silicon substrate 32, and essentially has a structure having two well-known silicon diodes. Also, the above 1st and 2nd P.
Surfaces of mold regions 33a and 33b and silicon substrate 32
Third to fifth electrodes 34 to 36 are formed on the back surface, respectively.

37 is an insulating assembly board;
A conductive bonding part 38 and first and second mounting parts 39 and 40 are formed on the surface of the silicon diode 31 , and a silicon diode 31 is mounted on the first mounting part 39 , and a light emitting element 1 is mounted on the second mounting part 40 . are fixed with conductive adhesive or the like. Furthermore, first and second leads 41 and 42 are integrally molded on the bonding section 38 and the second mounting section 40, respectively, and extend in a direction perpendicular to the back surface of the assembly board 37.

Next, the electrical connection of the above device will be briefly described.
The common electrode 12 is placed on the first mounting part 39, and the first electrode 11 and the third electrode 34 are both placed on the bonding part 38.
, the fourth electrode 35 is attached to the second mounting portion 40 with a gold wire 4, respectively.
3, 43, and so on.

FIG. 3 shows the circuit of the device of this embodiment, and D ₁ is the
The first light emitting part is centered around the 1PN junction 7, and _D2 is the first light emitting part.
The second light emitting part is centered around the 2PN junction 8, and _D3 is the second light emitting part.
A first diode consisting of a 1P type region 33a and a silicon substrate 32; _D4 a second diode consisting of a second P type region 33b and a silicon substrate 32; A, B;
are first and second terminals corresponding to first and second leads 41 and 42, respectively.

Next, the device of this embodiment will be explained based on the circuit diagram of FIG.

First, when the first terminal A is made positive and the second terminal B is made negative, the current flows through the first diode _D3 and the second light emitting section.
Since the light passes through _D2 , the device of this embodiment emits green light. Furthermore, when the polarities of the first and second terminals A and B are changed, the current passes through the second light emitting diode _D4 and the first light emitting section _D1 , so that the device of this embodiment emits red light. Furthermore, in this embodiment device, terminals A and B
When an alternating current wave is applied between them, the first light emitting section _D1 and the second light emitting section _D2 alternately emit light. At this time, if the period of the alternating current wave is extremely shortened, the first and second light emitting parts D ₁ ,
D ₂ appears to emit light at the same time, resulting in a mixed color of the colors emitted from both light emitting parts.

In this example, a multicolor light emitting element having an NPPN structure was used, but an element having a PNNP structure may also be used.
In this case, in the circuit shown in Figure 3, D ₃ and D ₄ correspond to the first and second light emitting parts of the multicolor light emitting element, and D ₁ and D ₂ correspond to the first and second diodes made of silicon diodes, respectively. , therefore, it operates similarly to this embodiment.

As is clear from the above description, according to the present invention,
A multi-color light emitting device can be easily obtained by connecting two junctions of multi-color light emitting elements having an NPPN or PNNP structure in anti-parallel.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional multicolor light emitting device, FIG. 2 is a sectional view showing a multicolor light emitting device according to the present invention, and FIG. 3 is a circuit diagram showing the circuit of the embodiment of the device shown in FIG. 1...Multicolor light emitting element, 7, 8...1st, 2nd PN
Junction, D ₃ , D ₄ ...first and second diodes.

Claims (1)

[Scope of utility model registration request] It has first and second PN junction parts that emit light in different colors, and each color light emitting element has an NPPN (or PNNP) structure, and first and second diodes, and both of the first and second diodes have a (or P layer) and the P layer (or N layer) of the multicolor light emitting element are electrically connected to each other, and one N layer (or P layer) of the multicolor light emitting element and the first diode The P layer (or N layer), the other N layer (or P layer) of the multicolor light emitting element, and the P layer (or N layer) of the second diode are electrically connected, respectively. A multicolor light emitting device.