JP2003008070A - Light emitting diode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light emitting diode in which the mounting density can be increased furthermore, filling of black weather-resistant resin can be facilitated and failure rate of product can be lowered. SOLUTION: The LED 1 has a concave reflector 3c at the forward end of a lead 3a, and mounts a light emitting element 2 on the bottom face wherein the lead 3a is branched into dummy leads 3d which are sealed with transparent epoxy resin 5. Since three leads 3a, 3b and 3d lead out from the transparent epoxy resin 5 are bent to support the LED 1 vertically, even a vertical draw-out structure can be surface mounted by reflow furnace. Since adjacent LEDs can be mounted tightly with no interval even in case of a display, mounting density can be enhanced to the extreme. Furthermore, a difference required for controlling the liquid level of black weather-resistant resin can be provided easily between the height H2 at the lower end of a convex lens 6 and the height H1 at the lower end of the transparent epoxy resin 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode (hereinafter, also abbreviated as "LED") in which a light emitting element and an electrical connection portion between the light emitting element and a lead are sealed with a light transmissive material such as transparent epoxy resin. It is related to. In the present specification, the LED chip itself is referred to as a “light emitting element”, and the entire light emitting device including an optical device such as a package resin or a lens system on which the LED chip is mounted is referred to as a “light emitting diode” or “LED”. To do.

[0002]

2. Description of the Related Art Conventionally, a display device has been developed in which a large number of light emitting diodes are arranged vertically and horizontally to display characters and images. As a surface mount LED used for such a display device, there is one as shown in FIG. FIG. 5 is a vertical cross-sectional view showing the overall configuration of a conventional surface mount light emitting diode.

The LED 41 shown in FIG.
The light emitting element 42 is mounted on the tip of one lead 43a of the pair of leads 43a and 43b for supplying electric power to 2. Then, the light emitting element 42 and the other lead 43
After b and b are electrically connected by bonding with a wire 44, these are sealed with a transparent epoxy resin 45, and a light emitting surface 46 having a convex lens shape is molded on the light emitting surface side of the light emitting element 42. And a pair of leads 43
The LED 41 is formed by bending a and 43b along the side surface and the lower surface of the transparent epoxy resin 45 into a substantially U shape.

[0004]

However, in the LED 41 having such a structure, the pair of leads 43a, 4 is formed.
Since 3b is drawn out in the lateral direction, it is necessary to provide a space between the adjacent LEDs when forming a display device, and thus there is a limit to improvement in packaging density. Also,
Since the display device is often installed outdoors, in order to prevent the corrosion of the lead portion that is pulled out and to improve the visibility, a black weather resistant resin is filled between the LEDs and cured. Then, the lead portion that is pulled out is covered. As a black weather resistant resin,
For example, black urethane resin, black silicone resin, or the like is used. At this time, the liquid level of the black weather resistant resin must be controlled to be higher than the height h1 of the lead portions 43a and 43b that are pulled out and lower than the height h2 of the lower end of the convex lens 46. However, in general, a display device is required to have a wide viewing angle.
The height of the end of the lens approaches the height of the light emitting element, and h1 and h
Since the difference between 2 is small, it is not easy to maintain the liquid level of the black weather resistant resin during this period, and there has been a problem that the product defect rate becomes high.

Therefore, an object of the present invention is to provide a light emitting diode which can have a higher packaging density and can be easily filled with a black weather resistant resin to reduce a product defect rate.

[0006]

A light emitting diode according to the invention of claim 1 is a light emitting diode comprising a light emitting element, a pair of leads for supplying electric power to the light emitting element, and a light transmissive material. The light transmissive material seals the light emitting element and a portion for electrically connecting the light emitting element to the pair of leads, and forms a light emitting surface on the light emitting surface side of the light emitting element. The pair of leads are led out in the back direction with respect to the central emission direction of the light emitting element, one or both of the pair of leads are branched, and the pulled out portions of all the leads are The light emitting diode is bent so as to stand upright.

In the LED having such a structure, since the leads are drawn out in the vertical direction, it is possible to mount the LED closely without adjoining the adjacent LEDs even when forming a display device. It is possible to improve the mounting density. Further, one or both of the pair of leads are branched, and the pulled out portions of the three or more leads are bent to stand up to support the LEDs. Therefore, even in the vertical lead-out structure, surface mounting by a reflow furnace is performed. Is possible. Further, even if the LED has a lens shape capable of obtaining a wide light distribution characteristic, there is a considerable difference in height between the light emitting surface made of the light transmissive material and the lower end of the light transmissive material from which the pair of leads are drawn out. Therefore, it is easy to control the liquid level of the black weather-resistant resin during this period, and thus the product defect rate due to the filling of the black resin can be suppressed to an extremely low level.

In this way, the light emitting diode can have a higher packaging density and can be easily filled with the black weather resistant resin to reduce the product defect rate.

According to a second aspect of the invention, in the light emitting diode according to the first aspect, one or both of the pair of leads are branched outside the light transmissive material.

Therefore, the volume of the metal part occupying the inside of the light transmissive material is smaller than that in the case where one or both of the pair of leads are branched inside the light transmissive material, and the temperature becomes close to 200 ° C. The occurrence rate of product defects such as cracks in the light transmissive material due to the difference in the coefficient of thermal expansion during surface mounting in an exposed reflow furnace is further reduced.
Further, when the branched portion becomes the bottom surface of the bent lead, the ground contact area increases and the weight balance shifts to the lower side to improve the stability of the LED.

In this way, a light emitting diode is obtained which has a lower incidence of product defects at high temperatures, a larger ground area, and improved stability.

A light emitting diode according to a third aspect of the present invention is the light emitting diode according to the first aspect, wherein the pair of leads are pulled out in a rear direction with respect to a central radiation direction of the light emitting element. By bending one or both of the tip portions so as to wrap around, the grounding area when bent is increased, and the pulled out portions of the pair of leads are bent so as to stand while supporting the light emitting diode. It is what

In the LED having such a configuration, the ground area when bent by bending one end of the pair of leads instead of branching one or both of the leads so as to be large is large. LE by bending the pulled out part of the lead
Since D is supported and standing upright, surface mounting by a reflow furnace is possible even with a vertical drawing structure. Further, since the leads are drawn out in the vertical direction, it is possible to closely mount the adjacent LEDs even when it is used as a display device in a display device, so that the mounting density can be improved to the utmost limit. it can. Further, since there is a considerable height difference between the light emitting surface made of the light transmitting material and the lower end of the light transmitting material from which the pair of leads are drawn out, the liquid of the black weatherproof resin is provided therebetween. It is easy to control the surface, and therefore the product defect rate due to the black resin filling can be suppressed to a very low level.

In this way, the light emitting diode can have a higher packaging density and can be easily filled with black weatherproof resin to reduce the product defect rate.

A light emitting diode according to a fourth aspect of the present invention is the light emitting diode according to any one of the first to third aspects, wherein the lead from the center of the branched leads or the portion from the center of the bent lead is located. The light emitting diode is temporarily fixed to a mounting board prior to surface mounting.

LED according to the inventions of claims 1 to 3
In the above, the leads extending in the vertical direction are bent to increase the ground contact area so that the LED stands stably. However, when passing through a reflow oven for surface mounting, hot air is blown onto the LEDs,
There is a possibility that the LED set up on the mounting board may fall down. Therefore, of the parts of the lead that were bent and became the bottom surface, the part from the center that had nothing to do with electrical connection was temporarily fixed to the mounting board with an adhesive or the like prior to surface mounting. There is no risk of the LED falling over due to the hot air, and the surface mounting can be reliably performed.

In this way, the light emitting diode can be surely mounted on the surface without the risk of falling by the hot air of the reflow furnace.

According to a fifth aspect of the present invention, in the light emitting diode according to any one of the first to fourth aspects, the central emission direction of the light emitting element is inclined by a predetermined angle from the direction perpendicular to the mounting substrate. The extended portions of all the leads or the extended portions of the pair of leads are bent so as to support and stand up the light emitting diode.

Since the display LED is often installed at a high place in the display LED, when the LED is mounted vertically on the substrate, the light emitted upward does not enter the eyes of the human eye and is used as a display. The efficiency of using the light will deteriorate. Therefore, by mounting the LED so as to be inclined at a predetermined angle from the direction perpendicular to the mounting substrate, the central emission direction of the light emitting element can be directed downward at a predetermined angle. As a result, most of the light emitted from the LED comes into the eyes of the human, and the LED has excellent characteristics as a display LED.

In this way, the light emitting diode can exhibit excellent characteristics when used as a display device.

According to a sixth aspect of the present invention, in the light emitting diode according to any one of the first to fifth aspects, the light emitting surface has an elliptical shape that collects and emits the light emitted from the light emitting element to the outside. It is a convex lens.

By forming the light emitting surface of the LED as such a convex lens, the light emitted from the light emitting element is collected and externally radiated. Therefore, if it is mounted on a substrate and used as a display device, the brightness that can be visually recognized outdoors even in the daytime is obtained. Will have. Furthermore, by mounting the elliptical convex lens with the major axis in the horizontal direction and the minor axis in the vertical direction, the light spreads in the horizontal direction and the emission angle of the light narrows in the vertical direction. The LED has a light emission characteristic preferable as a device.

In this way, the light emitting diode can exhibit excellent characteristics when used as a display device.

A light emitting diode according to a seventh aspect of the present invention is the light emitting diode according to any one of the first to sixth aspects, wherein a concave reflecting mirror is formed on one of the pair of leads, and the concave reflecting mirror is formed. The light emitting element is mounted on the bottom surface of the.

In the LED having such a structure, the light emitted from the light emitting surface of the light emitting element in a substantially horizontal direction can be reflected by the concave reflecting mirror and emitted from the light emitting surface.
The external radiation efficiency can be improved, and the brightness during lighting can be further increased.

By thus increasing the external radiation efficiency, it is possible to further improve the contrast at the time of lighting and at the time of extinguishing, and a light emitting diode can be obtained which has better characteristics when used as a display device.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a light emitting diode of the present invention will be described below with reference to the drawings.

First Embodiment First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1A shows a first embodiment of the present invention.
Front view showing the overall configuration of the light emitting diode according to
(B) is a side view. FIG. 2 is a side view showing the overall configuration of the light emitting diode according to the modification of the first embodiment of the present invention.

As shown in FIG. 1A, in the light emitting diode 1 according to the first embodiment, one of the pair of leads 3a and 3b for supplying electric power to the light emitting element 2 has a concave tip end. As the reflecting mirror 3c, the light emitting element 2 is mounted on the bottom surface thereof. The light emitting element 2 is electrically connected by being bonded to the other lead 3b by the wire 4, and the one lead 3a branches under the concave reflecting mirror 3c to become a dummy lead 3d. Pair of leads 3
It extends downward like a and 3b. The upper part of the pair of leads 3a and 3b and the dummy lead 3d, the concave reflecting mirror 3c, the light emitting element 2 and the wire 4 are sealed with a transparent epoxy resin 5 as a light transmitting material, and
An elliptical convex lens 6 as a light emitting surface is formed on the light emitting surface side of the light emitting element 2.

Then, as shown in FIGS. 1A and 1B, the pair of leads 3a and 3b and the dummy lead 3d drawn from the transparent epoxy resin 5 are formed by bending the bending lines 3A and 3A.
All three of them are bent at the same angle at two points of 3B, and the bottom surface 3C is adjusted so as to be perpendicular to the central emission direction of the light emitting element 2, and the LED 1 is made vertical by the three leads 3a, 3b, 3d. Is supposed to stand. In this way, one lead 3a of the pair of leads 3a, 3b is branched, and the pulled out portions of the three leads 3a, 3b, 3d are bent to support the LED 1 so that it stands up. Even with the vertical drawer structure, surface mounting by the reflow furnace is possible. Here, in order to reliably prevent the LED 1 from tipping over due to hot air in the reflow furnace, the bottom surface 3C of the dummy lead 3d is temporarily fixed to the mounting substrate with an adhesive. The bottom surface 3C of the pair of leads 3a and 3b
Are electrically connected to the mounting board by cream solder.

Since the three leads 3a, 3b, 3d are vertically extended, the bottom surface 3C does not extend beyond the transparent epoxy resin 5 as shown in FIG. 1 (b). By thus bending, even when it is used as a display device, it is possible to closely mount the adjacent LEDs without mounting a space therebetween, and thus the mounting density can be improved to the utmost limit. Further, as shown in FIG. 1A, the height H2 of the lower end of the convex lens 6 as the light emitting surface made of the transparent epoxy resin 5 and the three leads 3 are used even for the lens shape for wide light distribution.
Transparent epoxy resin 5 from which a, 3b and 3d are drawn out
It is possible to provide a height difference from the height H1 of the lower end of the above so that the liquid level of the black weather resistant resin can be easily controlled. Therefore, the product defect rate due to the black resin filling can be suppressed to an extremely low level. In addition, since the black weather-resistant resin also wraps around the lower side of the transparent epoxy resin 5, the transparent epoxy resin 5
It is also possible to reduce the reflection of external light on the bottom surface of the.

Further, as shown in FIG. 1A, in the LED 1 of the first embodiment, one lead 3a
A reflecting mirror 3c is formed at the tip of the, and the light emitting element 2 is mounted on the bottom surface of the reflecting mirror 3c. As a result, the light emitted from the light emitting surface of the light emitting element 2 in a substantially horizontal direction can also be reflected by the reflecting mirror 3c and emitted from the convex lens 6, so that the external emission efficiency can be improved, and at the time of lighting. The brightness can be further increased. By thus increasing the external radiation efficiency, it is possible to further improve the contrast between the time of lighting and the time of turning off.

Further, since the light emitting surface is the elliptical convex lens 6, when the display device is mounted, the elliptical shape is mounted with the major axis direction being the horizontal direction and the minor axis direction being the vertical direction. As a result, the light spreads in the horizontal direction and the emission angle of the light narrows in the vertical direction, and thus the LED 1 having the preferable light emission characteristics as a display device is obtained.
Becomes

In this way, the LED of the first embodiment is
In No. 1, the mounting density can be increased, the black weather-resistant resin can be easily filled, the product defect rate can be reduced, and excellent characteristics can be exhibited when the device is used as a display device. Furthermore, the first embodiment
Since high mounting accuracy can be realized in the LED 1 by surface mounting,
The problem of uneven brightness and uneven color due to misalignment during mounting can be avoided.

Next, an LED of a modified example of the first embodiment will be described with reference to FIG. The LED 11 of the modification of the first embodiment has almost the same overall configuration as the LED 1. The difference is that the parts of the three leads 3a, 3b, 3d that are drawn from the transparent epoxy resin 5 support the LED 11 so that the central emission direction of the light emitting element 2 is inclined by a predetermined angle θ from the direction perpendicular to the bottom surface 3C. The points are bent along the bending lines 3A and 3B so as to stand upright.

In the case of the LED for a display, since the display is often installed at a high place, when the LED is mounted vertically on the substrate, the light emitted upward does not enter the eyes of a person and is used as a display. The efficiency of using the light will deteriorate. Therefore, by mounting the LED 11 so as to incline by a predetermined angle θ from the direction perpendicular to the mounting substrate, the central emission direction of the light emitting element 2 can be directed downward by the predetermined angle θ. As a result, most of the light emitted from the LED 11 enters the eyes of the human, and the LED has excellent characteristics as a display LED. Here, θ is about 2.5 to 5 degrees.

In this way, in the LED 11 of the modification of the first embodiment, the packaging density can be further increased, the black weather resistant resin can be easily filled, and the product defect rate can be reduced. Therefore, it is possible to exhibit more excellent characteristics when used as a display device.

In the display device, the brightness peak of the LED 11 may be θ = 0 degrees depending on the installation location.
There is a demand to change the specifications to 2.5 degrees, 5 degrees, etc. In the LED of the present invention, this requirement can be easily satisfied by changing the setting of the lead bending press device that bends the portion of the lead pulled out from the transparent epoxy resin 5.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a front view showing the overall configuration of the light emitting diode according to the second exemplary embodiment of the present invention before bending the leads.

As shown in FIG. 3, in the light emitting diode 21 of the second embodiment, one of the pair of leads 23a, 23b for supplying electric power to the light emitting element 22 is lead 23a.
The light emitting element 22 is mounted on the bottom of the reflecting mirror 23c having a concave shape, and the light emitting element 22 includes the wire 2
4 is bonded to the other lead 23b for electrical connection. One lead 23a is branched near the lower end to form a dummy lead 23d.
The upper portion of the pair of leads 23a and 23b, the concave reflecting mirror 23c, the light emitting element 22 and the wire 24 are sealed by a transparent epoxy resin 25 as a light transmissive material, and the light emitting surface side of the light emitting element 22. An elliptical convex lens 26 as a light emitting surface is formed on the.

After that, a pair of leads 23a and 23b drawn out from the transparent epoxy resin 25 are bent into a bending line 2
3A and 23B, the LED 2 is bent by bending as shown in the side view of FIG. 1 (b) or FIG.
1 can be made to stand on the mounting substrate, and surface mounting by a reflow furnace is possible even with a vertical drawing structure. here,
In order to reliably prevent the LED 21 from tipping over due to hot air in the reflow furnace, the bottom surface 23C of the dummy lead 23d is temporarily fixed to the mounting board with an adhesive. The bottom surface 23C of the pair of leads 23a and 23b is electrically connected to the mounting board by cream solder.

Since one lead 23a is branched outside the transparent epoxy resin 25,
The volume of the metal portion occupying the inside of the transparent epoxy resin 25 is smaller than that in the case where one lead 23a is branched inside the transparent epoxy resin 25, and at the time of surface mounting in a reflow furnace exposed to a high temperature of about 200 ° C. The rate of product defects such as cracking in the transparent epoxy resin 25 due to the difference in coefficient of thermal expansion between metal and resin is further reduced.
In addition, since all the branched portions of the dummy lead 23d are the bent bottom surface 23C of the lead, the ground area to the mounting substrate is increased and the stability of the LED 21 is further increased.

Further, since the pair of leads 23a and 23b are drawn out in the vertical direction, it is possible to mount the LEDs closely to each other without forming a gap even in the case of a display device. The packaging density can be improved to the limit.

Further, the lower end of the convex lens 26 as a light emitting surface made of the transparent epoxy resin 25 and the pair of leads 2
Transparent epoxy resin 25 from which 3a and 23b are drawn out
Since there is a considerable difference in height from the lower end of the, it is easy to control the liquid level of the black weather-resistant resin during this period, and therefore it is possible to keep the product defect rate due to the filling of the black resin extremely low. it can. Moreover, since the black weather resistant resin can be made to wrap around to the lower side of the transparent epoxy resin 25, the bottom surface of the transparent epoxy resin 25 can be made black, and the reflection of external light can be reduced.

Further, as shown in FIG. 3, in the LED 21 of the second embodiment, a reflecting mirror 23c is formed at the tip of one lead 23a, and the light emitting element 22 is mounted on the bottom surface of the reflecting mirror 23c. ing. As a result, the light emitted from the light emitting surface of the light emitting element 22 in a substantially horizontal direction can be reflected by the reflecting mirror 23c and emitted from the convex lens 26, so that the external emission efficiency can be improved and at the time of lighting. The brightness can be further increased. In this way, by increasing the external radiation efficiency,
It is possible to further improve the contrast between when the lamp is turned on and when it is turned off.

Since the light emitting surface is the elliptical convex lens 26, when the display device is mounted, the elliptical shape is mounted with the major axis direction being the horizontal direction and the minor axis direction being the vertical direction. As a result, the light is spread in the horizontal direction and the emission angle of the light is narrowed in the vertical direction, so that the LED 2 having a preferable light emission characteristic as a display device is obtained.
It becomes 1.

Thus, the LED of the second embodiment is
In No. 21, the mounting density can be further increased, the black weather resistant resin can be easily filled, the product defect rate can be reduced, and excellent characteristics can be exhibited when the device is used as a display device. Further, the crack occurrence rate of the transparent epoxy resin 25 at the time of mounting on the board can be further lowered, and the stability when placed on the mounting board is further increased.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a front view showing an overall configuration before bending the leads of the light emitting diode according to the third exemplary embodiment of the present invention.

As shown in FIG. 4, the light emitting diode 31 of the third embodiment differs from the light emitting diode 21 of the second embodiment only in that the bent portion of one lead is branched or bent. The other parts of the configuration are the same, so some explanations are omitted.

The light emitting element 32 is mounted on the bottom surface of the one lead 33a as a concave reflecting mirror 33c, and the one lead 33a is bent so as to wrap around at the lower end to form a dummy lead 33d. The upper part of the pair of leads 33a, 33b, the concave reflecting mirror 33c, the light emitting element 32, etc. are sealed by a transparent epoxy resin 35 as a light transmissive material, and a light emitting surface is provided on the light emitting surface side of the light emitting element 32. An elliptical convex lens 36 is formed.

After that, the pair of leads 33a and 33b drawn out from the transparent epoxy resin 35 are bent into the bending line 3
3A and 33B, by bending as shown in the side view of FIG. 1 (b) or FIG.
1 can be made to stand on the mounting substrate. As a result, surface mounting by a reflow furnace is possible even with a vertical drawing structure, and LED by hot air in the reflow furnace is provided.
In order to surely prevent 31 from falling, the dummy lead 33
Similar to the second embodiment, the bottom surface 33C of d is temporarily fixed to the mounting substrate with an adhesive.

Here, since the dummy leads 33d are formed outside the transparent epoxy resin 35, the rate of product defects such as cracks occurring in the transparent epoxy resin 35 due to the difference in the coefficient of thermal expansion between the metal and the resin is increased. Less. Further, since all the bent portions reaching the dummy lead 33d are the bent bottom surface 33C, the ground area to the mounting board is increased and the weight balance is shifted to the lower side.
Will be more stable.

The same applies to the fact that the mounting density can be improved and the product defect rate due to the filling of the black resin can be suppressed to an extremely low level. Further, since the light emitting element 32 is mounted on the bottom surface of the reflecting mirror 33c, the external radiation efficiency can be improved, and the brightness at the time of lighting can be further increased.

The advantage of the LED 31 of the third embodiment compared to the LED 21 of the second embodiment is that by bending a pair of leads 33a and 33b at bending lines 33A and 33B, Since the wrap-around portion 33C comes to the right end in FIGS. 1 (b) and 2, the weight balance is such that it is easy to fall to the left side in FIGS. 1 (b) and 2, but the bottom surface 33C is on the right side in the LED 31. This means that the weight balance will be closer to the right side and less likely to fall.

In this way, the LED 31 of the third embodiment is
In the above, the packaging density can be further increased, the black weather resistant resin can be easily filled, the product defect rate can be reduced, and excellent characteristics can be exhibited when the device is used as a display device. Further, the crack occurrence rate of the transparent epoxy resin 35 at the time of mounting on the board can be further lowered, and the stability when placed on the mounting board is further increased.

In each of the above-described embodiments, the description has been made assuming that the lead and the wire supply the electric power to the light emitting element, but the form in which the light emitting element is electrically connected to the lead is not limited to this. For example, a Zener diode having a light emitting element mounted thereon may be mounted on one lead, and the Zener diode and the other lead may be electrically connected by a wire. Alternatively, a bipolar electrode may be provided on the lower side of the light emitting element, and electrical connection with the lead may be made by a bump or the like (in this case, a wire is not necessary).

In each of the above-described embodiments, an example in which a transparent epoxy resin is used as the light transmissive material has been described. However, conditions such as fluidity before curing, filling property, transparency after curing, and strength are set. Any light transmissive material may be used as long as it satisfies the requirements.

Further, in each of the above-described embodiments, an example in which the tip of one of the leads is used as a concave reflecting mirror and the light emitting element is mounted on the bottom surface thereof has been described, but it is not always necessary to use the concave reflecting mirror. The light emitting element may be mounted on the lead.

The configuration, shape, material, quantity, size, connection relationship, etc. of the other parts of the light emitting diode are not limited to those in the above-mentioned respective embodiments.

[0060]

As described above, the light emitting diode according to the invention of claim 1 comprises a light emitting element, a pair of leads for supplying electric power to the light emitting element, and a light transmissive material. And, by the light transmissive material,
The light emitting element and a portion for electrically connecting the light emitting element to the pair of leads are sealed, and a light emitting surface is formed on the light emitting surface side of the light emitting element. The light emitting element is led out in the back direction with respect to the radial direction, one or both of the pair of leads is branched, and the led out portions of all the leads support the light emitting diode to stand upright. It is bent into.

In the LED having such a configuration, since the leads are drawn out in the vertical direction, it is possible to mount the LED closely without adjoining the adjacent LEDs even when forming a display device. It is possible to improve the mounting density. Further, one or both of the pair of leads are branched, and the pulled out portions of the three or more leads are bent to stand up to support the LEDs. Therefore, even in the vertical lead-out structure, surface mounting by a reflow furnace is performed. Is possible. Further, even if the LED has a lens shape capable of obtaining a wide light distribution characteristic, there is a considerable difference in height between the light emitting surface made of the light transmissive material and the lower end of the light transmissive material from which the pair of leads are drawn out. Therefore, it is easy to control the liquid level of the black weather-resistant resin during this period, and thus the product defect rate due to the filling of the black resin can be suppressed to an extremely low level.

In this way, the light emitting diode can have a higher packaging density and can be easily filled with the black weather resistant resin to reduce the product defect rate.

According to a second aspect of the present invention, in the light emitting diode according to the first aspect, one or both of the pair of leads are branched outside the light transmissive material.

Therefore, in addition to the effect described in claim 1, a metal portion occupying the inside of the light transmissive material more than the case where one or both of the pair of leads are branched inside the light transmissive material. The volume of the product becomes smaller, and the occurrence rate of product defects such as cracking in the light transmissive material due to the difference in the coefficient of thermal expansion during surface mounting in a reflow furnace exposed to a high temperature of about 200 ° C. becomes smaller. Further, when the branched portion becomes the bottom surface of the bent lead, the ground contact area increases and the weight balance shifts to the lower side.
The stability of D is also improved.

In this way, the light emitting diode can be manufactured in which the incidence of product defects at high temperatures is further reduced and the ground area is increased to improve the stability.

A light emitting diode according to a third aspect of the present invention is the light emitting diode according to the first aspect, wherein the pair of leads are led out in a rear direction with respect to a central radiation direction of the light emitting element. By bending one or both of the tip portions so as to wrap around, the grounding area when bent is increased, and the pulled out portions of the pair of leads are bent so as to stand while supporting the light emitting diode. It is what

In the LED having such a structure, the ground contact area when bent by bending one end of the pair of leads instead of branching one or both of them is large, so that the ground area is large. In addition to the effect described in item 1, the pulled out portions of the pair of leads are bent to support the LEDs so that the LEDs stand upright. Therefore, surface mounting by the reflow furnace is possible even with the vertical lead structure.

Further, since the leads are pulled out in the vertical direction, the LEs adjacent to each other are also used in a display device.
Since it is possible to mount the device in close contact with D without making a space, it is possible to improve the mounting density to the limit. Further, since there is a considerable height difference between the light emitting surface made of the light transmitting material and the lower end of the light transmitting material from which the pair of leads are drawn out, the liquid of the black weatherproof resin is provided therebetween. It is easy to control the surface, and therefore the product defect rate due to the black resin filling can be suppressed to a very low level.

In this way, the light emitting diode can have a higher packaging density, can be easily filled with black weather resistant resin, and can reduce the product defect rate.

According to a fourth aspect of the present invention, in the light-emitting diode according to any one of the first to third aspects, the lead from the center of the branched leads or the portion from the center of the bent lead is formed. The light emitting diode is temporarily fixed to a mounting board prior to surface mounting.

LED according to the inventions of claims 1 to 3
In the above, the leads extending in the vertical direction are bent to increase the ground contact area so that the LED stands stably. However, when passing through a reflow oven for surface mounting, hot air is blown onto the LEDs,
There is a possibility that the LED set up on the mounting board may fall down. Therefore, among the respective portions of the lead that have been bent and become the bottom surface, the portion from the center that is not related to electrical connection is temporarily fixed to the mounting substrate with an adhesive or the like prior to surface mounting. In addition to the effect according to any one of claims 1 to 3, LE is obtained by hot air in a reflow furnace.
There is no risk of D falling, and surface mounting can be performed reliably.

In this way, the light emitting diode can be surely mounted on the surface without the risk of falling due to the hot air of the reflow furnace.

According to a fifth aspect of the present invention, in the light emitting diode according to any one of the first to fourth aspects, the central emission direction of the light emitting element is inclined by a predetermined angle from the direction perpendicular to the mounting substrate. The extended portions of all the leads or the extended portions of the pair of leads are bent so as to support and stand up the light emitting diode.

In the case of the LED for a display, since the display is often installed at a high place, when the LED is mounted vertically on the substrate, the light emitted upward does not enter the eyes of the human eye and is used as a display. The efficiency of using the light will deteriorate. Therefore, by mounting the LED so as to be inclined at a predetermined angle from the direction perpendicular to the mounting substrate, in addition to the effect according to any one of claims 1 to 4, the central emission direction of the light emitting element is at a predetermined angle. It can be turned downward. This allows LE
Most of the light emitted from D enters the eyes of humans, and it has excellent characteristics as an LED for a display.

In this way, the light emitting diode can exhibit excellent characteristics when used as a display device.

According to a sixth aspect of the present invention, in the light emitting diode according to any one of the first to fifth aspects, the light emitting surface has an elliptical shape for collecting and emitting the light emitted from the light emitting element to the outside. It is a convex lens.

Since the light emitting surface of the LED is such a convex lens, in addition to the effect described in any one of claims 1 to 5, the light emitted from the light emitting element is condensed and externally radiated. When the display device is mounted on a substrate, it has a brightness that can be visually recognized outdoors even in the daytime. Furthermore, by mounting the elliptical convex lens with the major axis in the horizontal direction and the minor axis in the vertical direction, the light spreads in the horizontal direction and the emission angle of the light narrows in the vertical direction. The LED has a light emission characteristic preferable as a device.

In this way, the light emitting diode can exhibit excellent characteristics when used as a display device.

According to a seventh aspect of the present invention, in the light emitting diode according to any one of the first to sixth aspects, the concave reflecting mirror is formed on one of the pair of leads, and the concave reflecting mirror is formed. The light emitting element is mounted on the bottom surface of the.

According to the LED having such a structure,
In addition to the effect according to any one of claims 6 to 6, light emitted in a substantially horizontal direction from the light emitting surface of the light emitting element can be reflected by the concave reflecting mirror and emitted from the light emitting surface. Therefore, the external radiation efficiency can be improved, and the brightness at the time of lighting can be further increased.

By thus increasing the external radiation efficiency, the contrast between the time of lighting and the time of extinguishing can be further improved, and a light emitting diode can be obtained which has better characteristics when used as a display device.

[Brief description of drawings]

FIG. 1 (a) is a front view showing the overall structure of a light emitting diode according to a first embodiment of the present invention, and FIG. 1 (b) is a side view.

FIG. 2 is a side view showing an overall configuration of a light emitting diode according to a modified example of the first exemplary embodiment of the present invention.

FIG. 3 is a front view showing an overall configuration before bending the leads of the light emitting diode according to the second exemplary embodiment of the present invention.

FIG. 4 is a front view showing an overall configuration before bending a lead of a light emitting diode according to a third embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view showing the overall structure of a conventional surface mount light emitting diode.

[Explanation of symbols]

1, 11, 21, 31 Light emitting diode 2, 22, 32 Light emitting element 3a, 3b, 23a, 23b, 33a, 33b 1 pair of leads 3c, 23c, 33c Concave reflecting mirrors 3d, 23d Lead from the center 5, 25 , 35 Light transmissive material 6, 26, 36 Light emitting surface (elliptical convex lens) 33d Part from the center of the lead

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takemasa Yasukawa             Aichi Prefecture Kasuga-cho, Nishikasugai-gun Ochiai character Nagahata 1             Address within Toyoda Gosei Co., Ltd. (72) Inventor Hideyuki Nakano             Aichi Prefecture Kasuga-cho, Nishikasugai-gun Ochiai character Nagahata 1             Address within Toyoda Gosei Co., Ltd. (72) Inventor Satoshi Honda             Sanke, 3-6 Kitano, Niiza City, Saitama Prefecture             N Denki Co., Ltd. (72) Inventor Asahi Shiraishi             Sanke, 3-6 Kitano, Niiza City, Saitama Prefecture             N Denki Co., Ltd. F-term (reference) 5F041 AA41 DA18 DA25 DA44 DA59                       FF01

Claims (7)

[Claims] 1. A light emitting diode comprising a light emitting element, a pair of leads for supplying electric power to the light emitting element, and a light transmissive material, wherein the light transmissive material allows the light emitting element and the light emission. A portion for electrically connecting the element to the pair of leads is sealed, and a light emitting surface is formed on the light emitting surface side of the light emitting element, and the pair of leads is the central radiation of the light emitting element. With respect to the direction, one or both of the pair of leads is branched, and the extracted portions of all the leads are bent so as to support the light emitting diode to stand. A light emitting diode. 2. The outside of the light transmissive material is the
The light emitting diode according to claim 1, wherein one or both of the leads of the pair are branched. 3. The pair of leads are drawn out in a back direction with respect to a central emission direction of the light emitting element, and one or both of the pair of leads are bent by bending so as to wrap around. The light emitting diode according to claim 1, wherein a grounding area when the light emitting diode is turned on is increased, and the pulled out portions of the pair of leads are bent so as to support and stand up the light emitting diode. 4. The lead from the center or the part from the center of the bent lead of the branched leads is temporarily fixed to a mounting substrate before surface mounting the light emitting diode. The light emitting diode according to any one of claims 1 to 3. 5. The lead-out portions of all the leads or the lead-out portions of the pair of leads form the light emitting diode so that a central emission direction of the light emitting element is inclined at a predetermined angle from a direction perpendicular to a mounting substrate. The light emitting diode according to any one of claims 1 to 4, wherein the light emitting diode is bent so as to be supported and erected. 6. The light emitting surface according to claim 1, wherein the light emitting surface is an elliptical convex lens that collects and emits the light emitted from the light emitting element to the outside. diode. 7. A concave reflecting mirror is formed on one of the pair of leads, and the light emitting element is mounted on a bottom surface of the concave reflecting mirror. The light emitting diode according to any one of claims.