JP2002344027A - Surface mount LED - Google Patents

Abstract

(57) [Problem] An object of the present invention is to provide a surface-mounted LED having a wide directivity with a simple configuration. SOLUTION: A chip substrate 1 having a surface mounting terminal portion.
2 and an LED chip 13 mounted on this chip substrate
And a lens portion 14 formed of a transparent or translucent resin so as to surround the LED chip on the chip substrate.
The surface mount LED 10 is configured such that the lens portion 14 has a mortar-shaped concave portion 14a near the center of the upper surface thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount LED for use in, for example, key illumination and backlight illumination.

[0002]

2. Description of the Related Art Conventionally, such a surface mount LED is configured as shown in FIG. 4, for example. That is, in FIG. 4, the surface-mounted LED 1
It is composed of an ED chip 3, an LED chip 3, and a lens unit 4 formed so as to cover the entire surface of the chip substrate 2.

The above-mentioned chip substrate 2 is configured as a flat copper-clad wiring substrate, and is mounted in a state of being horizontally mounted on a mounting substrate when used. The chip substrate 2 has the LED chip 3 bonded to the chip mounting land 2a and the gold wire 3 connected to the electrode land 2b adjacent to the chip mounting land 2a.
a (or gold bumps).

The lens section 4 is made of a transparent or translucent material, for example, a thermoplastic resin, and is formed by a transfer molding method. This lens part 4
By transmitting the light from the LED chip 3,
It functions as a light emitting unit.

[0005] The surface mount LED 1 having such a structure is manufactured by placing the LED on the chip mounting land 2 a of the chip substrate 2 at the time of manufacturing.
The ED chip 3 is bonded, and wire bonding is performed on the electrode lands 2b, whereby LE
The D chip 3 is mounted. Thereafter, the lens portion 4 is formed by the transfer molding method so as to cover the LED chip 3, and the surface-mounted LED 1 is completed.

[0006] The surface-mounted LED 1 thus manufactured
According to this, the chip substrate 2 is placed and mounted in a state horizontal to the mounting substrate 5 (shown by a chain line in FIG. 4). When a driving voltage is applied to the LED chip 3 from the terminal portion 2b provided on the chip substrate 2, the LED chip 3 emits light, and this light is emitted to the outside through the lens portion 4. .

[0007]

By the way, when the surface-mounted LED 1 having such a structure is used for illuminating a key of a cellular phone or the like, for example, the lens unit 4 of the surface-mounted LED 1
The key is illuminated by light emitted in a substantially horizontal direction from the entire circumference of the side surface of the key. On the other hand, the surface mounting L
As shown in the light distribution characteristics of FIG.
Has a narrow directivity centered on an optical axis O perpendicular to the surface of the optical disk. Therefore, among the light emitted from the surface-mounted LED 1, the light emitted from the upper surface of the lens unit 4 is hardly used for the illumination of the key, so that the use efficiency of the light used for the illumination of the key is reduced. Would.

[0008] In view of the above, an object of the present invention is to provide a surface-mounted LED having a wide directivity with a simple configuration.

[0009]

According to the present invention, there is provided a chip substrate having a surface mounting terminal, an LED chip mounted on the chip substrate, and an LED chip mounted on the chip substrate. A lens portion formed of a transparent or translucent resin so as to surround the lens portion, wherein the lens portion has a mortar-shaped concave portion near the center of the upper surface thereof. Achieved by LEDs.

The surface mount LED according to the present invention is preferably such that the central axis of the mortar-shaped concave portion of the lens portion is an LED.
It is almost coincident with the optical axis of the chip.

In the surface mount LED according to the present invention, preferably, a side surface around the lens portion is formed to taper upward.

[0012] In the surface mount LED according to the present invention, the side surface around the lens portion is preferably formed as a part of a spherical surface having a center below the upper surface of the LED chip.

[0013] The surface-mounted LED according to the present invention is preferably such that a side surface around the lens portion is perpendicular to an upper edge of the LED.
It is formed in the shape of a truncated cone crossing the optical axis of the chip below the upper surface of the LED chip.

In the surface mount LED according to the present invention, preferably, the surface of the chip substrate is roughened.

The surface mount LED according to the present invention is preferably provided with a layer having a roughened surface on the surface of the chip substrate.

According to the above configuration, the mortar-shaped concave portion is provided at the center of the upper surface of the lens portion surrounding the LED chip. The light is totally reflected by the inner surface, and travels over the entire circumference in the lateral direction. Therefore, a surface-mounting LED having a wide directivity can be obtained. For example, when used for illumination of a key of a cellular phone or the like, backlight illumination, or the like, light emitted from the surface-mounting LED toward the entire periphery in the horizontal direction. As a result, the light utilization efficiency is improved, and brighter illumination can be obtained.

When the central axis of the mortar-shaped concave portion of the lens portion substantially coincides with the optical axis of the LED chip,
The light emitted from the LED chip and incident on the concave portion is totally reflected by the inner surface of the concave portion, so that the light is substantially uniformly reflected over the entire circumference.

When the side surface around the lens portion is tapered upward, that is, the side surface around the lens portion is formed as a part of a spherical surface having a center below the upper surface of the LED chip. Or if the side surface around the lens portion is formed in a truncated cone shape in which the perpendicular of the upper edge intersects the optical axis of the LED chip below the upper surface of the LED chip, When the light that is emitted and enters the side surface around the lens unit is emitted to the outside from this side surface, the light is refracted slightly downward based on the refractive index, so that it travels in a substantially horizontal direction from the side surface of the lens unit. Therefore, a wider directivity can be obtained.

When the surface of the chip substrate is roughened, or when the surface of the chip substrate is provided with a layer having a roughened surface, the light is emitted from the LED chip and the surface of the chip substrate is roughened. Is irregularly reflected by the rough surface, and a part of the light travels in a substantially horizontal direction from the side surface of the lens portion, so that a wider directivity can be obtained.

Thus, according to the present invention, the LED
The light emitted from the chip is reflected over the entire circumference in the lateral direction by the mortar-shaped concave portion on the upper surface of the lens portion, and further, is refracted in a substantially horizontal direction by the tapered shape of the side surface of the lens portion, so that the light is laterally refracted. A wide directivity can be obtained over the entire circumference of the direction. Therefore, brighter illumination can be obtained by using the surface-mounted LED for key illumination, backlight illumination, and the like.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. still,
Since the embodiments described below are preferred specific examples of the present invention, various technically preferred limitations are added.
The scope of the present invention is not limited to these embodiments unless otherwise specified in the following description.

FIG. 1 shows the configuration of an embodiment of the surface mount LED according to the present invention. In FIG. 1, the surface mount LE
D10 is configured as a chip LED, and includes a chip substrate 12 to be mounted on a mounting substrate 11 (shown by a dashed line in FIG. 1B) and an LE mounted on the chip substrate 12.
D chip 13, LED chip 13 and chip substrate 1
A lens portion 14 formed so as to cover the entire surface of
It is composed of

The chip substrate 12 is configured as a flat copper-clad wiring substrate, and has chip mounting lands (not shown) and electrode lands 12a on its surface. Then, the chip substrate 12 has LE on the chip mounting land.
The D chip 13 is die-bonded and electrically connected to an electrode land (not shown) adjacent to the chip mounting land by a gold wire or a gold bump.

The lens section 14 is made of a transparent or translucent material, for example, a thermosetting epoxy resin.
It is formed by the transfer molding method. The lens unit 14 functions as a light emitting unit by emitting light from the LED chip 13 from the front surface.

The above configuration is almost the same as that of the conventional surface mount LED 1, but the surface mount LED according to the embodiment of the present invention.
The ED 10 has a different configuration in the following points. That is, the lens portion 14 has a mortar-shaped concave portion 14a at the center of the upper surface thereof, and a peripheral side surface 14a.
b is formed so as to taper upward.

The recess 14a is arranged such that the central axis thereof substantially coincides with the optical axis perpendicular to the chip substrate 12 from the LED chip 13. Also, the side surface 14b
Is specifically formed of a spherical surface, and the center of the spherical surface is located below the upper surface of the LED chip 13, and in the illustrated case, near the lower surface of the chip substrate 12.

Further, the surface of the chip substrate 12 is configured as a rough surface. The rough surface is formed by roughening the surface of the chip substrate 12 itself or by providing a layer having a rough surface on the surface of the chip substrate 12. The layer having a roughened surface is formed by, for example, applying a resist to the surface of the chip substrate 12 and processing the surface of the resist layer into a rough surface with a file or the like.

Surface Mount LED 10 According to Embodiment of the Present Invention
Is configured as described above, and the chip substrate 12 is placed and mounted in a horizontal state with respect to the mounting substrate 11.
Then, an LED is connected to a terminal portion provided on the chip substrate 12.
When a driving voltage is applied to the chip 13, the LED 13
The chip 13 emits light, and the light from the LED chip 13 exits through the lens unit 14 to the outside.

At this time, the light L1 entering the concave portion 14a of the lens portion 14 travels in the horizontal direction by being totally reflected as shown in FIG. 1B, and is again totally reflected by the side surface 14b of the lens portion 14. Then, the light is incident on the surface of the chip substrate 12. Here, since the surface of the chip substrate 12 is rough, the light L <b> 1 is irregularly reflected on the surface of the chip substrate 12, and a part of the light L <b> 1 is emitted from the side surface 14 b of the lens unit 14 and irradiated in the lateral direction. Will be done. In this case, the recess 14a is LE
Since the center is substantially coincident with the D chip 13, the light reflected by the concave portion 14a is substantially uniform over the entire circumference.

The light L2 incident on the side surface 14b of the lens portion 14 has a center at L as described above.
Since the ED chip 13 is formed in a spherical shape below the upper surface, as shown in FIG.
When the light passes through 4b, it is refracted slightly downward, so that it is emitted almost horizontally from the side surface 14b of the lens unit 14.

The light L3 incident on the upper surface of the lens portion 14 other than the concave portion 14a is refracted by the upper surface of the lens portion 14, and is largely deviated from the optical axis and emitted obliquely upward. Here, the upper surface of the lens portion 14 other than the concave portion 14a is appropriately adjusted depending on the size of the concave portion 14a and the shape of the side surface 14b in accordance with the purpose of use of the surface-mounted LED 10, and may be omitted in some cases.

As described above, according to the surface-mounted LED 10 according to the embodiment of the present invention, the light L1 and L2 are guided in the lateral direction by the concave portion 14a and the side surface 14b. As described above, the light emitting device has a wide directivity of approximately 180 degrees, and in particular, is configured to increase the amount of light in the horizontal direction (−180 degrees and +180 degrees). Therefore, when lighting such as a key and a backlight provided adjacent to the mounting board is performed using the surface-mounted LED 10 having such a configuration, the light use efficiency of the surface-mounted LED 10 is improved, and bright illumination is obtained. Will be done.

In the above embodiment, the lens unit 1
The side surface 14b of the fourth side is formed in a spherical shape, but is not limited to this, and is tapered upward so that light incident on the side surface 14b from the LED chip 13 can be guided in the lateral direction. It may be formed. For example, the side surface 14b of the lens unit 14 may be formed in a truncated cone shape. In this case, the shape of the truncated cone is preferably such that a perpendicular to the optical axis of the LED chip 13 at the upper edge thereof intersects the optical axis below the upper surface of the LED chip 13, for example, near the lower surface of the chip substrate 12. Selected. This allows
The light is emitted slightly upward from the LED chip 13 and the side surface 14b
Is refracted slightly downward at the side surface 14b,
The light is emitted laterally from the side surface 14b. further,
In the embodiment described above, the surface of the chip substrate 12 is roughened, but is not limited to this, and may not be roughened.

[0034]

As described above, according to the present invention, L
Since a mortar-shaped concave portion is provided at the center of the upper surface of the lens portion surrounding the ED chip, light emitted upward from the LED chip in the optical axis direction is totally reflected by the inner surface of the concave portion, and is horizontally reflected. It will proceed over the entire circumference. Therefore, a surface-mounted LED having a wide directivity can be obtained.
For example, when used for illumination of a key of a mobile phone or the like, backlight illumination, or the like, the amount of light emitted from the surface-mounted LED toward the entire periphery in the horizontal direction increases, and the light use efficiency improves. This means that brighter illumination can be obtained. Thus, according to the present invention, a surface-mounted LED having a wide directivity can be provided with a simple configuration.

[Brief description of the drawings]

FIG. 1A is a plan view and FIG. 1B is a side view showing an embodiment of a surface mount LED according to the present invention.

FIG. 2 is a perspective view showing the surface mount LED of FIG. 1;

FIG. 3 is a graph showing light distribution characteristics of the surface-mounted LED of FIG. 1;

FIG. 4 is a perspective view showing a configuration of an example of a conventional surface mount LED.

FIG. 5 is a graph showing light distribution characteristics of the surface-mounted LED of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Surface mounting LED 11 Mounting board 12 Chip board 13 LED chip 14 Lens part 14a Depression 14b Side surface

Claims (7)

[Claims] 1. A chip substrate having a surface mounting terminal portion, an LED chip mounted on the chip substrate, and a transparent or translucent resin formed on the chip substrate so as to surround the LED chip. A lens portion, wherein the lens portion has a mortar-shaped recess near the center of the upper surface thereof. 2. The LED according to claim 1, wherein a central axis of the mortar-shaped concave portion of the lens portion substantially coincides with an optical axis of the LED chip. 3. The surface-mounted LED according to claim 1, wherein a side surface around the lens portion is tapered upward. 4. The surface-mounted LED according to claim 3, wherein a side surface around the lens portion is formed as a part of a spherical surface having a center below an upper surface of the LED chip. 5. The side surface around the lens portion is formed in a truncated cone shape in which a vertical line at an upper edge crosses the optical axis of the LED chip below the upper surface of the LED chip. 3. The surface mounted LED according to item 3. 6. The surface mount LED according to claim 1, wherein a surface of the chip substrate is roughened. 7. The surface-mounted LED according to claim 1, wherein a layer having a roughened surface is provided on a surface of the chip substrate.