JP4336734B2 - Light emitting diode and LED light - Google Patents

Description

  The present invention relates to a light-emitting diode (hereinafter referred to as “LED”) and an LED light using the same, and in particular, a lamp such as a taillight or a brake light of an automobile, or a warning lamp or sign for construction. The present invention relates to a light emitting diode and an LED light used as a display device.

  In recent years, as the brightness of LEDs has increased, LED lights using LEDs as light sources have been increasingly used for lamps such as automobile backlights. The LED has a sharp spectrum, excellent visibility, and has a merit that the signal transmission speed to the succeeding vehicle is improved because the response speed when lighting is fast. It is expected to increase safety. Furthermore, since the LED itself is a monochromatic light source, it is not necessary to filter light other than the necessary color like an incandescent light bulb, and it is highly efficient as a monochromatic light source, leading to energy saving.

  FIG. 11 shows a conventional LED light 200. The LED light 200 includes, as a lens-type LED 201, a light emitting element 202, a pair of lead frames 203a and 203b, a bonding wire 204 that electrically connects the light emitting element 202 and the lead frame 203b, and a transparent epoxy resin 205. Have. The light emitting element 202 is mounted on a lead frame 203a. The light emitting element 202 and the lead frame 203b are wire-bonded, and the whole is sealed in a convex lens shape with a transparent epoxy resin 205.

  Further, as components of the LED light 200, a rotating paraboloidal reflecting mirror 206 that reflects light emitted from the lens-type LED 201 upward, a Fresnel lens 207 positioned above the lens-type LED 201, and light incidence A resin lens 209 having an uneven interface 209a on the side is provided.

  The LED light 200 described above emits light upward and obliquely upward by causing the lens-type LED 201 to emit light. The light emitted above the lens-type LED 201 is collected by the Fresnel lens 207 and emitted as parallel light. Further, the light emitted obliquely above the lens-type LED 201 is reflected by the reflecting mirror 206 and emitted upward. In this way, all the light emitted from the lens-type LED 201 is emitted substantially parallel to the resin lens 209 side. The resin lens 209 diffuses incident light at the uneven interface 209 a and radiates it from the resin lens 209. As a result, the resin lens 209 emits light having a spread of about 20 degrees, which is the standard for in-vehicle backlights.

  However, in the conventional LED light 200, the light emitted from the lens-type LED 201 is converted into parallel light by the Fresnel lens 207 disposed on the light emission side, and this parallel light is diffused by the resin lens 209. There is an inconvenience that the thickness of the system is increased and the LED lamp is enlarged. If the reflecting mirror 206 is omitted, the number of parts can be reduced and the thickness can be reduced, but the light emitted from the light emitting element 202 obliquely upward and in the side surface direction cannot be used, and the radiation efficiency is lowered. Further, since the emitted light passes through the Fresnel lens 207 and the resin lens 209 and is emitted to the outside, the degree of freedom in appearance is low.

  Therefore, for example, Patent Document 1 discloses an LED light that is thin and has a good appearance and that can increase the radiation efficiency.

  This LED light is a light source such as an LED, and a first reflection that reflects light emitted from the light source disposed at a position on the central axis facing the light source as light in a direction substantially orthogonal to the central axis of the light source. A mirror, and a second reflecting mirror disposed around the first reflecting mirror and reflecting the light reflected by the first reflecting mirror as light in the direction of the central axis. Yes. In such a configuration, the light emitted from the light source is reflected by the first reflecting mirror in a direction substantially orthogonal to the central axis, and the reflected light is reflected by the second reflecting mirror in the central axis direction. Vehicle signal light having a predetermined radiation angle can be emitted over a predetermined area.

JP 2001-93312 (FIG. 2)

  However, according to the LED light of Patent Document 1, since most of the emitted light from the light source is emitted upward, if the positional accuracy of the central axis of the light source with respect to the first reflecting mirror is reduced, the first reflecting mirror As a result, the amount of reflected light reflected in the total reflection direction becomes non-uniform, and there is a problem that light and dark (brightness difference) occurs on the surface of the LED light. In particular, as the light source and the first reflecting mirror come closer to each other, the difference in brightness due to the positional deviation becomes significant. Further, the light source and the first reflecting mirror are separate parts, and each of them must be positioned and must be held so as not to be displaced, which takes time for manufacturing. Furthermore, when a physical force is applied, the position of the component may be displaced.

  Even if the light source and the first reflecting mirror are positioned with high accuracy, it is difficult to avoid variations in light distribution characteristics due to the structure of the light source. LEDs with high light concentration have a large effect on the light distribution characteristics due to misalignment of the light emitting elements. When a light source with such a variation in light distribution characteristics is used, there is an inherent problem that light and darkness occurs on the surface of the LED light. It is to do.

  Accordingly, an object of the present invention is to provide a light-emitting diode and an LED light that achieves a reduction in thickness, is excellent in productivity, and has a uniform brightness in all directions while suppressing variations in light distribution characteristics.

In order to achieve the above object, the present invention
A light emitting element;
A translucent material for sealing the light emitting element,
When the light emitting element has a constant determined by the radiation intensity according to the emission angle θ of the light emitting element as k, where I (θ) is the radiation intensity at the emission angle θ of the emitted light with respect to the central axis direction,
I (θ) = k · cos θ + (1−k) · sin θ
(However, k ≦ 0.6)
And
The translucent material is
A reflecting surface that reflects light emitted from the light emitting element in a circumferential direction perpendicular to the central axis of the light emitting element and centering on the central axis;
A side emission surface that emits light reflected by the reflection surface, and
Provided is a light emitting diode in which the relationship between the radius R of the reflecting surface and the height H of the side radiation surface is H <R.

In order to achieve the above object, the present invention
The light emitting diode;
An LED light comprising: a reflecting mirror that reflects light emitted from the light emitting diode.

  According to the light emitting diode of the present invention, the light emitted from the light emitting element can be emitted not only in the central axis direction but also in the direction perpendicular to the central axis while reducing the thickness of the light emitting diode. Since the radiation in the direction orthogonal to the central axis becomes large based on the proximity to the light, a wide light distribution characteristic in the radiation range can be obtained.

  Further, even if a positional deviation between the central axis of the light emitting element and the central axis of the first reflecting mirror occurs, it is possible to prevent a difference in the brightness of the surface of the LED light.

  Moreover, even if a light source having a variation in light distribution characteristics of the light emitting element is used, it is possible to prevent a difference in brightness of the surface of the LED light by emitting light to a wide radiation range. it can.

In the light emitting diode, the light emitting element has a radiation intensity at an emission angle θ of the emitted light with respect to the central axis direction as I (θ), and a constant determined by the radiation intensity according to the emission angle θ of the light emitting element is k. ,
I (θ) = k · cos θ + (1−k) · sin θ
(However, k ≦ 0.6)
By providing as described above, the light distribution characteristics in the side surface direction can be improved, and a stable amount of light can be emitted in a wide range.

  Further, according to the LED light of the present invention, light emitted from the light emitting element is emitted not only in the central axis direction but also in a direction perpendicular to the central axis, and the proximity of the light emitting element and the reflecting surface. Therefore, the radiation in the direction orthogonal to the central axis becomes large, so that it is excellent in visibility, imparts novel vision to the LED light, and provides a wide light distribution characteristic in the radiation range.

In the LED light, the light emitting element has a radiation intensity at an emission angle θ of the emitted light with respect to the central axis direction as I (θ), and a constant determined by the radiation intensity according to the emission angle θ of the light emitting element is k. When
I (θ) = k · cos θ + (1−k) · sin θ
(However, k ≦ 0.6)
It is characterized by being.
According to such a configuration, the light emitted from the light emitting element in the side surface direction increases, and a high-intensity LED light that hardly causes variations in light irradiation properties due to the positional accuracy with the reflecting mirror can be obtained.

Embodiments of the present invention will be described below.
In the following description, a coordinate system is defined in which the central axis of the light emitting element is the Z axis, the upper surface position of the light emitting element on the Z axis is the origin, and the origin is provided with an X axis and a Y axis orthogonal to the Z axis. . However, the Z axis is also referred to as the central axis Z.

  FIG. 1: shows the whole structure of the LED light 1 which concerns on the 1st Embodiment of this invention, (a) is a top view, (b) is AA sectional drawing of (a), (c) is ( It is an enlarged view of P part of b). This LED light 1 includes an LED 2 using a light emitting element 6A having a predetermined light distribution characteristic at the center of a disk-shaped main body, and a reflecting mirror 3 having a concentric and stepwise reflecting surface 3a around the LED 2. Have.

  The reflecting mirror 3 is formed of a transparent acrylic resin, and the reflecting surface 3a is formed by performing aluminum vapor deposition on the upper surface after forming to make a mirror surface. Each reflective surface 3a is inclined at about 45 degrees with respect to the XY plane, as shown in FIG. 5C, and reflects light incident from the X (Y) direction and radiates it in the Z direction.

  2A and 2B show the LED 2, in which FIG. 2A is a longitudinal sectional view, FIG. 2B is a plan view, and FIG. 2C is a side view. This LED 2 integrally seals the lead frames 5a and 5b, the light emitting element 6A, the bonding wire 7 that electrically connects the lead frame 5b and the light emitting element 6A, and the lead frames 5a and 5b and the light emitting element 6A. A transparent epoxy resin 8 that stops and has an optical surface, a reflecting mirror 9 having a flat surface 9a and a reflecting surface 9b, and a part of a spherical surface centering on the light emitting element 6A, make light XY It consists of a radiation surface 10 that radiates in the direction.

  The lead frames 5a and 5b are made of a copper alloy and are provided on the XY plane with a gap for insulation, and the light emitting element 6A is mounted at the origin position of the lead frame 5a having a large area. .

  The light emitting element 6A has an inverted pyramid shape in which the bottom side of the rectangular parallelepiped shape is cut obliquely, is face-up joined to the lead frame 5a, and the upper surface is a light emitting surface. Further, for the purpose of maintaining the light emission intensity of the LED 2 at a predetermined value by reducing the number of use as much as possible, a large current type (high output type) is used. The light emitting element 6A may be mounted on the lead frame 5a by flip chip bonding.

  The transparent epoxy resin 8 uses an epoxy resin having a refractive index of 1.55, and has a flat surface 9a at the center portion of the upper surface (a portion directly above the light emitting element 6A). Further, the reflecting mirror 9 is formed by providing the reflecting surface 9b following the flat surface 9a. The proximity optical system is formed by arranging the light emitting element 6A in the vicinity of the reflecting mirror 9 and integrally molding it.

  The reflecting mirror 9 has a flat surface 9a that radiates light emitted from the light emitting element 6A in a directly upward direction, and a parabola with a central portion of the light emitting surface of the light emitting element 6A that is the origin of coordinates in the figure as a focal point and an X axis as a symmetry axis. And a reflection surface 9b having a circular reflection shape obtained by rotating a part of the reflection surface around the central axis Z. It is also possible to adopt a configuration in which the reflecting mirror 9 is not provided with the flat surface 9a depending on the application.

  The reflecting mirror 9 is a first reflecting mirror that reflects the light emitted from the light emitting element 6A. As shown in (c), the radius R of the reflecting surface 9b is larger than that of the light emitting element 6A. The relationship between the height H of the radiation surface 10 and the radius R is here formed so that most of the light emitted in the form of corners can be effectively emitted to the side surface, where H = 2.0 mm and R = 3.5 mm. Is H <R. Further, the distance (thickness of the transparent epoxy resin 8) h between the light emitting element 6A and the flat surface 9a is set to 0.5 mm so that a relatively large solid angle is formed by forming a proximity optical system. .

  FIG. 3 shows a configuration of the light emitting element 6A. From the bottom layer to the top layer, an n-type GaP substrate 101, an n-type AlInGaP cladding layer 102 on the n-type GaP substrate 101, a layer 103 having a light-emitting layer, A p-type AlInGaP cladding layer 104 and a p-type GaP window layer 105 are sequentially formed as an epitaxial layer, and an AuZn contact 106 for making ohmic contact with the window layer 105 is formed on the p-type GaP window layer 105. Thus, an Al bonding pad (positive electrode) 107 is formed. Further, an Au alloy electrode (negative electrode) 108 is formed under the n-type GaP substrate 101. The n-type GaP substrate 101 is transparent to the wavelength of light emitted from the light-emitting layer, and the n-type AlInGaP clad layer 102 and the p-type AlInGaP clad layer 104 are translucent. The n-type GaP substrate 101 has a hypotenuse 6c cut and molded after the above epitaxial layer is formed.

FIG. 4 is a conceptual diagram illustrating light distribution characteristics of the light emitting element 6A. The radiant intensity radiated from the upper surface 6a and the side surface 6b (four side surfaces) of the light emitting element 6A is the sum of the radiant intensity radiated from the upper surface 6a and the radiant intensity radiated from the four side surfaces 6b. θ) is expressed by the following equation (1).
I (θ) = k · cos θ + (1−k) · sin θ (1)

  Here, k · cos θ represents the radiation intensity radiated from the upper surface 6a, and (1-k) · sin θ represents the radiation intensity radiated from the side surface 6b. θ is an angle with respect to the Z axis in the light emitting element 6A, and when the value of k changes, the distribution of the light emitted from the upper surface 6a and the light emitted from the side surface 6b changes.

  FIG. 5 shows changes in radiation intensity (Z-axis direction) when θ is changed for light emitting elements having different light distribution characteristics based on the above-described formula (1). Indicates the definition of an angle. (B) is a state in which 60% of light is emitted from the upper surface 6a at k = 0.6 (upper 60%), and is a light emitting element having a rectangular parallelepiped shape. (C) is a light emitting element having a rectangular parallelepiped shape in which 40% from the top surface 6a and 60% in total from the side surface 6b are emitted at k = 0.4 (upper 60%). Moreover, (d) is the light emitting element 6A of the present invention having an inverted pyramid type. The light distribution characteristics can be adjusted by changing the element size. For example, in the case of the light emitting element 6A with k = 0.4, the light absorption loss in the element is reduced by forming the light emitting element 6A with a size smaller than that of the light emitting element 6A with k = 0.6. The amount can be further increased.

  In the light-emitting element 6 having the light distribution characteristic shown in FIG. 5B, light is emitted from the upper surface 6a and the side surface 6b, and the radiation intensity decreases as θ increases. Further, in the light emitting element 6 having the light distribution characteristic of (c), the radiation intensity in the side surface direction is improved, so that the decrease of the radiation intensity due to the change of θ is smaller than that of (b). Further, in the light emitting element 6A shown in (d), by providing the oblique side portion 6c on the n-type GaP substrate 101, the light radiation in the side surface direction is improved, and the radiation intensity is not easily lowered due to the change of θ. .

  The light distribution characteristics of the LED 2 are the light distribution characteristics of the light emitting element 6A described above, the positional accuracy of the optical surface composed of the light emitting element 6A, the flat surface 9a, the reflecting surface 9b, and the radiation surface 10, and the lead frame 5a of the light emitting element 6A. Depends on the mounting position accuracy and the setting position accuracy with respect to the mold when the lead frame 5a and the optical surface are integrally molded. In order to prevent the light distribution in the θ direction shown in FIG. 2B from being biased, the uniformity of the light emitted in the circumferential direction (360 °) of the radiation surface 10 around the Z axis is required. However, if there is a positional shift between the light emitting element 6A and the optical surface, uneven light distribution in the θ direction occurs depending on the shift amount. In particular, the proximity optical system of the LED 2 according to the present invention has a structural characteristic that uneven light distribution is likely to occur due to the occurrence of a slight positional deviation.

  FIG. 6 shows light emitted directly upward from the LED 2 and light reaching the reflecting surface 3a due to a change in light distribution characteristics when the central axis of the light emitting element 6A in the LED 2 deviates from the optical surface in the X-axis direction. When the light emitting element 6A having a GaP substrate is used, if the amount of deviation occurs in the X-axis direction during production, the effective radiation efficiency ratio decreases. In the figure, it is clearly reduced particularly at 0.3 mm or more.

  FIGS. 7A and 7B show the observation conditions for the amount of light emitted from the LED 2, and are diagrams represented by Φij obtained by dividing the entire direction around the LED 2 into 32 parts. As shown in (a), 360 [deg.] Around the Z axis of LED2 is divided into eight (j = 1-8), and as shown in (b), 0 [deg.]-20 [deg.] With respect to the Z axis. Angle range (i = 1), angle range from 20 ° to 60 ° (i = 2), angle range from 60 ° to 100 ° (i = 3), angle range from 100 ° to 180 ° ( i = 4), and the amount of light emitted from the LED 2 to these regions will be described below. Here, the angle range region from 0 ° to 20 ° with respect to the Z axis is directly emitted from the LED 2 to the vicinity of the Z axis, and the angle range region from 60 ° to 100 ° with respect to the Z axis is reflected from the LED 2. It is assumed that the light is radiated to the mirror 3 and then reflected by the reflecting mirror 3 in the direction near the Z-axis and radiated outside.

  FIG. 8A shows the total light amount deviation of the LED 2 when a rectangular parallelepiped light emitting element having an upper light distribution characteristic of 60% under the observation conditions shown in FIG. 7, and the total light quantity deviation is 0 in the X direction. This is obtained by setting the conditions under which six steps of deviations from 0.0 to 0.5 mm have occurred, and shows the total light quantity deviation in each direction connected by lines. As the amount of deviation increases, the total light quantity deviation increases. FIG. 5B shows the total light amount deviation of the LED 2 when a light emitting element having a rectangular parallelepiped shape having an upper 40% light distribution characteristic is used. The increase in light emission from the side surface 6b increases the total light amount deviation. Has been improved. FIG. 6C shows the total light amount deviation of the LED 2 when the inverted pyramid type light emitting element 6A is used. Even if the deviation amount increases, the total light amount deviation of the LED 2 is increased by emitting light from the oblique side portion 6c. Occurrence is suppressed to a certain level.

  In this way, by forming the light emitting element 6A in an inverted pyramid shape, light emitted from the side surface of the light emitting element is increased as compared with the light emitting element having a rectangular parallelepiped shape. The total light amount deviation in the effective radiation range due to the position shift is reduced. Therefore, when the inverted pyramid type light emitting element 6A having a light distribution characteristic of k = 0.6 or less is used, the position of the light emitting element 6A mounted on the lead frame 5a is in the X axis (or Y axis) direction from the Z axis. Even if a dimensional deviation within 0.1 mm occurs, it can be compensated by the light distribution characteristics of the light emitting element 6A, so that the total light quantity deviation in the effective radiation range is almost eliminated and there is no visual influence.

  The above-described LED 2 can be manufactured by, for example, a transfer mold method. The manufacturing method by the transfer mold method will be described below. Here, an inverted pyramid light emitting element 6A having a light distribution characteristic of k = 0.6 is used. First, the light emitting element 6A is face-up bonded to the lead frame 5a formed by pressing. Next, the Al bonding pad 107 of the light emitting element 6 </ b> A and the lead frame 5 b are electrically connected by the bonding wire 7. Next, the lead frames 5a and 5b on which the light emitting element 6A is mounted are placed on a mold that can be divided into upper and lower parts, and positioned by being sandwiched from above and below. Next, the transparent epoxy resin 8 is poured into the mold. Next, the transparent epoxy resin 8 is cured at 160 ° C. for 5 minutes. Next, the mold 2 is separated into upper and lower parts and the LED 2 in which the transparent epoxy resin 8 is cured is taken out. In order to improve the releasability between the mold and the transparent epoxy resin 8, the transparent epoxy resin 8 containing a release component is used.

Next, the operation of the LED light 1 will be described.
When a power switch (not shown) of the LED light 1 is turned on by an operator, a power supply unit (not shown) applies a voltage to the lead frames 5a and 5b. The light emitting element 6A emits light based on application of voltage. The light emitted from the light emitting element 6A and emitted right above the Z axis is emitted from the flat surface 9a to the outside of the transparent epoxy resin 8, and is emitted externally. Further, 50 to 60% of the light emitted from the light emitting element 6A reaches the reflecting surface 9b having a solid angle of about 2.7 straud with respect to the light emitting element 6A, and is emitted from the light emitting element 6A to the Z axis. The light radiated in the substantially horizontal direction reaches the radiation surface 10 directly, and is directly radiated from the radiation surface 10 in a direction substantially parallel to the XY plane.

  The light emitted from the LED 2 substantially parallel to the XY plane is reflected by the reflecting surface 3a of the reflecting mirror 3 in the substantially Z-axis direction and is emitted to the outside.

  According to the LED light 1 of the first embodiment described above, the light emitting element 6A of the LED 2 constituting the proximity optical system uses a light emitting element 6A formed in an inverted pyramid shape, and its light distribution characteristic I (θ) = Since k in k · cos θ + (1−k) · sin θ is set to 0.6 or less and the light emitting element 6A and the optical surface are integrally formed by the transfer molding method, the light is emitted from the LED 2 The light in the X-axis direction reaching the reflecting mirror 3 has almost no deviation in the total amount of light in the effective radiation range, and can be emitted almost uniformly in the Z-axis direction by the reflecting mirror 3. Thereby, it is possible to obtain a thin lamp having a large reflecting mirror surface, no difference in surface brightness, and having a good appearance. As a result, when applied to the taillights and brake lights of automobiles, it is possible to improve the visibility of light from the lateral direction as well as directly behind the automobile.

  In the LED light 1 described above, the configuration using the LED 2 using the inverted pyramid light emitting element 6A having the light distribution characteristic of k = 0.6 has been described as an example. If the light emitting element 6A having optical characteristics is used, the total light amount deviation in the effective radiation range due to the positional deviation between the light emitting element 6A and the optical surface can be reduced to a level that does not cause a problem in practice.

  In the manufacture of the LED 2 by the transfer mold method, the transparent epoxy resin 8 is injected into the mold with the lead frames 5a and 5b sandwiched between the molds, so that the positioning accuracy between the light emitting element 6A and the optical surface is ± 0. It can be realized with high accuracy of 1 mm, and even in a proximity optical system configured using a light emitting element 6A with k = 0.6, it is stable by preventing variation in light distribution characteristics due to individual differences of LEDs 2. The LED light 1 having the quality as described above can be provided.

  Moreover, although the structure using the transparent epoxy resin 8 was demonstrated as a translucent material which seals the light emitting element 6A, even if it is another translucent material with the same translucency and other optical characteristics. Good. Moreover, although the transparent acrylic resin is used as a resin material which comprises the reflective mirror 3, other materials can also be used including other transparent resin. Further, the configuration, shape, quantity, material, size, connection relationship, and the like of other parts of the LED light are not limited to the embodiment.

  Moreover, although the reflective surface 9b was demonstrated as what applied the total reflection of resin, without performing a mirror surface process, the mirror surface process by metal vapor deposition etc. may be performed.

  9A and 9B show an LED 2a according to a second embodiment of the present invention, where FIG. 9A is a plan view of the LED 2a viewed from the Z direction, and FIG. 9B is a longitudinal sectional view of a portion of the light emitting element 6A in FIG. It is. This LED 2a is made of a GaP substrate AlInGaP using a translucent n-type GaP substrate, and is composed of an inverted pyramid light emitting element 6A having a light distribution characteristic of 60% (k = 0.6) and a copper alloy. The lead frame 5b is formed by bending a resin-sealed portion and the light emitting element 6A is mounted at the tip of the lead frame 5c. In addition, since the same reference numerals are given to portions having the same configuration as that of the first embodiment, a duplicate description is omitted.

  The LED 2a can be manufactured by, for example, a casting mold method. The manufacturing method by the casting mold method will be described below. Here, a light emitting element 6A having a light distribution characteristic of k = 0.6 is used. First, the lead frames 5b and 5c are punched by pressing. At this time, the lead frames 5b and 5c are not divided, and a plurality of rear ends are connected by leads. Next, the rear end connected by the lead is fixed to the support member. Next, the lead frames 5b and 5c are bent into a desired shape. Next, the light emitting element 6A is face-up bonded to the tip of the lead frame 5c. Next, the Al bonding pad 107 of the light emitting element 6 </ b> A and the lead frame 5 b are electrically connected by the bonding wire 7. Next, the lead frames 5b and 5c are moved onto the casting for molding. Next, a transparent epoxy resin 8 is injected into the casting. Next, the lead frames 5b and 5c are immersed in the casting into which the transparent epoxy resin 8 is injected. Next, the space in which the casting and lead frames 5b and 5c are arranged is evacuated, and air bubbles are removed from the transparent epoxy resin 8. Next, the transparent epoxy resin 8 is cured at 120 ° C. for 60 minutes. Next, the LED 2a in which the transparent epoxy resin 8 is cured is taken out from the casting.

  According to the LED 2a of the second embodiment described above, since the inverted pyramid light emitting element 6A is mounted on the lead frame 5c in which the resin-encapsulated portion is bent, the uniform light can be emitted over a wide range. Therefore, it is possible to manufacture by a casting mold method with excellent productivity. Further, even if a positional deviation between the light emitting element 6A and the optical surface occurs, if the deviation is small, the total light quantity deviation in the effective radiation range can be suppressed to a level that does not cause a problem in practice.

  Further, in the casting mold method, since the tips (free ends) of the lead frames 5b and 5c are not supported and restrained by casting, the positioning accuracy between the light emitting element 6A and the optical surface is ± 0.2 mm, which is based on the manufacturing by the transfer mold method. descend. In particular, it is difficult to achieve high positioning accuracy in the case where the light emitting element 6A is mounted on the plate thickness portion at the tip of the flat lead frame. However, productivity can be improved by increasing the allowable range of positioning accuracy, and the mass productivity is excellent. When the transparent epoxy resin 8 is cured for a long time, the thermal stress unevenness is reduced, and the lead frames 5b, 5c and the transparent epoxy resin 8 are less likely to be peeled off. Note that it is possible to stabilize the light distribution characteristics by selecting the manufacturing process management and the light distribution characteristics of the light emitting element 6A.

  10A and 10B show an LED 2b according to a third embodiment of the present invention, in which FIG. 10A is a plan view of the LED 2b viewed from the Z direction, and FIG. 10B is a longitudinal sectional view of a portion of the light emitting element 6A in FIG. It is. This LED 2b is made of a GaP substrate AlInGaP using a translucent n-type GaP substrate, and is composed of an inverted pyramid light emitting element 6A having a light distribution characteristic of 40% (k = 0.4) and a copper alloy. The plate-shaped lead frames 5b and 5d are configured. In addition, since the same reference numerals are given to portions having the same configuration as those of the first and second embodiments, redundant description is omitted.

  The light-emitting element 6A with k = 0.4 is formed in a smaller size (for example, 0.3 mm square) than the light-emitting element 6A with k = 0.6, thereby reducing the absorption loss inside the light-emitting element. Thus, the amount of radiation from the side surface 6b is further increased.

  The light emitting element 6A is mounted on the tip of a lead frame 5c punched out by press working.

  According to the LED 2b of the third embodiment described above, since the inverted pyramid type light emitting element 6A is mounted at the tip of the lead frame 5d, it is excellent in mass productivity while suppressing the total light quantity deviation in the effective radiation range. The contact area between the frames 5b and 5d and the transparent epoxy resin 8 can be reduced, which can make peeling more difficult. In addition, work steps such as bending of the lead frames 5b and 5d can be made unnecessary, so that productivity can be improved.

  In each of the above-described embodiments, the structure having the inverted pyramid type element shape as the light emitting element 6A has been described. However, as another element shape, the upper side (the light emission observation surface side) is obliquely cut. A pyramidal light emitting element may be used.

  The light emitting element 6A may be molded with a transparent epoxy resin 8 after being covered and sealed with a light transmissive resin containing a light diffusing material. In this case, light is diffused by the light diffusing material, and light can be emitted in a wider range.

  Moreover, you may use the fluorescent substance excited by the emitted light of 6 A of light emitting elements as a light-diffusion material. In this case, uniform light can be emitted in a wider range by emitting excitation light from the phosphor excited by the emitted light.

  Further, the light emitting diode has been described as sealing the light emitting element and molding the reflection surface and the side reflection surface, but the present invention is not limited to this, for example, a reflection formed separately with a translucent resin. A proximity optical system for the light emitting element can also be formed by attaching the surface and the side reflecting surface together with the light emitting element by sealing with a light transmissive material.

  Further, in each of the above-described embodiments, the reflecting mirror 9 has a circular reflection shape in which the origin of the light emitting element 6A is the focal point and a part of the parabola with the X axis as the symmetry axis is rotated around the central axis Z. The radiation surface 10 has been described as having a shape that forms part of a spherical surface centered on the light emitting element 6A. However, the light emitted from the light emitting element 6A is at a large angle with respect to the central axis Z. The shape is not particularly limited as long as the shape can radiate substantially in the side surface direction. In particular, under the conditions where the shape of the transparent epoxy resin 8 and the relationship of H <R shown in each example are satisfied, the reflecting mirror 9 comes close to the light emitting element 6A, and the LED of the LED due to the positional accuracy of the optical system is obtained. The same effect can be obtained with respect to the stability of the light distribution characteristics. Even when the relationship of H <R is not satisfied, the same effect can be obtained when h <1 mm. In addition, the reflection surface 9b has stable light distribution characteristics even when the proximity optical system is formed such that the shortest distance from the light emitting element 6A is less than ½ with respect to the radius R shown in FIG. Can increase the sex.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole structure of the LED light using LED which concerns on 1st Embodiment, (a) is a top view, (b) is AA sectional drawing of (a), (c) is (b) FIG. It is a figure which shows the structure of LED which concerns on 1st Embodiment, (a) is sectional drawing, (b) is a top view, (c) is a side view which shows the size of each part. It is a side view which shows the structure of the light emitting element which concerns on 1st Embodiment. It is a radiation conceptual diagram of the light radiated | emitted from the upper surface and side surface of the light emitting element which concerns on 1st Embodiment. The light distribution characteristic curve of the light emitting element which concerns on 1st Embodiment is shown, (a) is explanatory drawing of the angle with respect to the Z-axis of a light emitting element, (b) shows the change of the radiation intensity when k = 0.6. (C) is a characteristic diagram showing a change in radiant intensity when k = 0.4, and (d) is a characteristic diagram showing a change in radiant intensity in the case of an inverted pyramid type light emitting device. It is a related figure of the effective radiation efficiency ratio of LED which concerns on 1st Embodiment, and a X-axis direction shift | offset | difference. (A) And (b) is a conceptual diagram which shows the observation conditions of the light quantity radiated | emitted from LED. The total light quantity deviation of the effective radiation range of LED which concerns on 1st Embodiment is shown, (a) is a characteristic view which shows the total light quantity deviation of the effective radiation range in LED using the light emitting element whose light distribution characteristic is 60% above (B) is a characteristic diagram showing the total light amount bias of the effective radiation range in the LED using the upper 40% light emitting element, and (c) is the total light amount bias of the effective radiation range in the LED using the inverted pyramid type light emitting element. FIG. It is a figure which shows the whole structure of the LED light using LED which concerns on 2nd Embodiment, (a) is a top view, (b) is a longitudinal cross-sectional view of the light emitting element part of (a). It is a figure which shows the whole structure of the LED light using LED which concerns on 3rd Embodiment, (a) is a top view, (b) is a longitudinal cross-sectional view of the light emitting element part of (a). It is sectional drawing which shows the structure of the conventional LED light.

Explanation of symbols

1, LED light 3, reflecting mirror 3a, reflecting surfaces 5a, 5b, 5c, 5d, lead frame 6A, light emitting element 6a, upper surface 6b, side surface 6c, oblique side portion 7, bonding wire 8, transparent epoxy resin 8s, sealing resin 9, reflecting mirror 9a, flat surface 9b, reflecting surface 10, radiation surface 101, n-type GaP substrate 102, n-type AlInGaP cladding layer 103, layer 104 having a light emitting layer, p-type AlInGaP cladding layer 105, p-type GaP window layer 106, AuZn contact 107, Al bonding pad 108, Au alloy electrode 202, light emitting elements 203a and 203b, lead frame 204, bonding wire 205, transparent epoxy resin 206, reflecting mirror 207, Fresnel lens 209, resin lens 209a, interface

Claims (2)

A light emitting element;
A translucent material for sealing the light emitting element,
When the light emitting element has a constant determined by the radiation intensity according to the emission angle θ of the light emitting element as k, where I (θ) is the radiation intensity at the emission angle θ of the emitted light with respect to the central axis direction,
I (θ) = k · cos θ + (1−k) · sin θ
(However, k ≦ 0.6)
And
The translucent material is
A reflecting surface that reflects light emitted from the light emitting element in a circumferential direction perpendicular to the central axis of the light emitting element and centering on the central axis;
A side emission surface that emits light reflected by the reflection surface, and
A light emitting diode in which the relationship between the radius R of the reflecting surface and the height H of the side surface emitting surface is H <R. A light emitting diode according to claim 1 ;
An LED light comprising: a reflecting mirror that reflects light emitted from the light emitting diode.

Images