JP2001177156A - Side emitting led lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a side emitting LED lamp having uniform directivity, small deviation between LED elements and reduced in size. SOLUTION: This side emitting LED lamp 1 comprises a red LED element 5R, a green LED element 5G and blue LED element 5b arranged in one row in a direction perpendicular to the end 2c on a board 2 for loading LED elements. In this case, the elements 5R, 5G and 5B are sealed with a convex lens 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side emission type LED lamp suitable for a backlight of a liquid crystal display in a cellular phone or the like, and in particular, has a uniform directional characteristic and a small deviation between LED elements. The present invention relates to a small-sized side-emitting LED lamp.

[0002]

2. Description of the Related Art As a conventional side-emitting LED lamp,
For example, there is one disclosed in JP-A-10-290029.

FIG. 8 shows the side-emitting LED lamp. This LED lamp 1 is, as shown in FIG.
The first LED element 5 a and the second LED element 5 b are mounted on the LED element mounting board 2, and these LED elements 5 a and 5 b are sealed with a transparent mold resin 17. A common electrode 3c is formed on each of the front surface 2a and the back surface 2b of the LED element mounting substrate 2. One side surface 2d of the substrate 2 has a first individual electrode 3a and the other side surface 2d.
, A second individual electrode 3b is formed, and the common electrode 3c on the front surface 2a and the common electrode 3c on the back surface 2b are connected by a connection plating 4 'obtained by cutting through-hole plating in half. First and second LED elements 5a, 5b
Has a first electrode on the upper surface and a second electrode on the lower surface. The first electrode of the first LED element 5a is connected to the first individual electrode 3a by a bonding wire 6, and the first electrode of the second LED element 5b is connected to the second individual electrode 3b by a bonding wire 6. And the second electrodes of the first and second LED elements 5a and 5b are connected to the common electrode 3c on the surface 2a by a conductive adhesive.

When the LED lamp 1 is mounted on a printed circuit board 10, as shown in FIG. 8 (b), the LED element mounting board 2 is erected on the printed circuit board 10 with the end surface 2c of the board 2 facing down. The individual electrodes 3a, 3b and the common electrode 3c exposed on the back surface 2b of the element mounting substrate 2 and the corresponding wiring patterns 11a, 11b,
11c by solder 12. By passing a current between the wiring patterns 11a, 11b, 11c, the first and second LED elements 5a, 5
b, light 8 a and 8 b of the first and second colors are emitted in parallel to the surface of the printed circuit board 10 via the mold resin 17.

FIG. 9 shows directional characteristics in the horizontal direction. Since the LED lamp 1 has the same directional characteristics with respect to the two LED elements 5a and 5b as shown in the figure, when used as a backlight of a liquid crystal display, color unevenness in the liquid crystal display is reduced. Can be prevented.

[0006]

However, according to the conventional side-emitting type LED lamp, since the molding resin 17 has a rectangular shape, the directivity characteristics are greatly changed by the corners 7a as shown in FIG. Unable to uniformly illuminate the liquid crystal display.

The connection plating 4 'for connecting the common electrode 3c on the front surface 2a and the back surface 2b of the substrate 2 is provided with the LED elements 5a,
5b, the printed circuit board 1
When mounted on 0, the height dimension increases, and
Since the individual electrodes 3a and 3b are provided on the side surface 2d of the substrate 2, the width dimension increases. As described above, in a structure having electrodes on the peripheral end surface, when three or more LED elements are mounted, the electrode structure becomes complicated and large.

On the other hand, by arranging the two LED elements 5a and 5b obliquely when viewed from the light emitting side, the height dimension can be reduced. However, since the horizontal directivity differs between colors, Color unevenness occurs on the liquid crystal display.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a side-emitting type LED lamp having uniform directional characteristics and little deviation between LED elements.

[0010] Another object of the present invention is to provide a side emission type LED lamp which is reduced in size.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a plurality of LEs arranged in a row on the surface of a substrate.
A D element and a plurality of LEs extending in a column direction of the plurality of LED elements and provided in common with the plurality of LED elements;
And a convex lens for shaping the emitted light of the D element into light having a predetermined spread angle and emitting the light. According to the above configuration, by arranging the plurality of LED elements in a row, the deviation of the directional characteristics between the LED elements is reduced. In addition, uniform directional characteristics can be obtained by shaping the emitted light of the plurality of LED elements into light having a predetermined divergence angle using a convex lens and emitting the light.

In order to achieve the above object, the present invention provides a substrate comprising an insulating member, a front electrode formed on a surface of the substrate, a back electrode formed on a back surface of the substrate, A side-emitting LED lamp comprising: a through-hole plating for connecting to a back electrode; and a plurality of LED elements connected to the front electrode. According to the above configuration, by connecting the front electrode and the back electrode by through-hole plating, the size is reduced as compared with the case where the front electrode and the back electrode are connected by the metal provided on the side surface of the substrate.

[0013]

1A and 1B show a side emission type LED lamp according to a first embodiment of the present invention. The side-emitting LED lamp 1 includes an LED element mounting substrate 2 and a surface 2a of the LED element mounting substrate 2.
A red LED element 5R, a green LED element 5G and a blue LED L arranged in a line in a direction orthogonal to the end face 2c.
A convex lens that seals the ED element 5B and the LED elements 5R, 5G, and 5B, and shapes and emits light emitted from each of the LED elements 5R, 5G, and 5B into light having a predetermined spread angle (FIG. Are indicated by a dotted line).

The LED element mounting substrate 2 is made of a material having high heat resistance, such as glass epoxy resin or alumina, and has a common electrode 3C, a red electrode 3R, a green electrode 3G, and a blue electrode on the surface 2a. A red electrode 3R is formed on the rear surface 2b of the red electrode 3R, the green electrode 3G and the blue electrode 3B on the front surface 2a by through-hole plating 4, as shown in FIG. 3
R, a green electrode 3G and a blue electrode 3B are formed. The common electrode 3C on the front surface 2a and the green electrode 3G, the red electrode 3R, and the blue electrode 3B on the back surface 2b extend to the edge of the end surface 2c to facilitate mounting on a printed circuit board. Note that the LED element mounting substrate 2 has a surface 2a.
It is desirable to use one having high light reflectance for all of the emission wavelengths of the LED elements 5R, 5G, 5B, for example, a white one. As a result, the luminous efficiency is increased, and the power consumption can be reduced. 2e is the upper surface of the substrate 2,
2 d indicates the side surface of the substrate 2.

The red LED element 5R is about 600 to 70
It emits red light having a dominant emission wavelength of 0 nm. For example, InGaAlP (indium.
It is made of a gallium-aluminum-phosphorus-based semiconductor and has a first electrode on the upper surface and a second electrode on the lower surface. Red LED
The element 5R is such that the first electrode on the upper surface is a bonding wire 6
Is electrically connected to the red electrode 3R, and the second electrode on the lower surface is electrically and mechanically connected to the common electrode 3C by a conductive adhesive.

The green LED element 5G is about 510-58.
It emits green light having a dominant emission wavelength of 0 nm and is made of, for example, a GaN (gallium nitride) semiconductor, and has a first electrode and a second electrode on the upper surface. The green LED element 5G has a lower surface mechanically connected to the common electrode 3C with an adhesive, a first electrode electrically connected to the green electrode 3G by a bonding wire 6, and a second electrode connected to the bonding wire 6G. Is electrically connected to the common electrode 3C.

The blue LED element 5B is about 420 to 50
It emits blue light having a dominant emission wavelength of 5 nm, and is made of, for example, a GaN (gallium nitride) semiconductor and has a first electrode and a second electrode on the upper surface. The blue LED element 5B has a lower surface mechanically connected to the common electrode 3C by an adhesive, a first electrode electrically connected to the blue electrode 3B by a bonding wire 6, and a second electrode connected to the bonding electrode 6B. Is electrically connected to the common electrode 3C.

The convex lens 7 has a semi-cylindrical shape made of a transparent epoxy resin or a translucent epoxy resin mixed with a filler having a light diffusing effect, and has a surface parallel to the end face 2c. LED elements 5R, 5G, 5
B has the same directional characteristics. Also, the convex lens 7
Has a focal point behind the light emitting surface of each of the LED elements 5R, 5G, 5B. Thereby, each LED element 5R, 5G,
The emitted light of 5B can be diffused and emitted. In addition,
When light at a narrow angle is required, the focal point of the convex lens 7 is
The ED elements 5R, 5G, and 5B may be provided in front of the light emitting surfaces.

FIG. 2 shows a circuit configuration. As shown in FIG. 1, the LED lamp 1 includes LED elements 5R, 5G,
5B has a four-terminal configuration in which one end is a common terminal. That is, the anode of each LED element 5R, 5G, 5B is
Connected to the common terminal 15C, each LED element 5R, 5
The cathodes of G and 5B are connected to terminals 15G, 15R,
15B. Each LED element 5R, 5G, 5
By causing B to emit light simultaneously, separately, or by combining the two, seven colors can be emitted.

Next, a method of manufacturing the LED lamp 1 will be described with reference to the drawings.

FIGS. 3A, 3B and 3C show a multi-piece substrate. First, as shown in FIG. 1A, a multi-piece substrate 20 for manufacturing a large number of LED element mounting boards 2 is manufactured. This multi-piece substrate 20
M (for example, 42) vertically and n (for example, 15) horizontally
And a total of m × n (for example, 630) substrate portions 21 serving as the LED element mounting substrates 2. One substrate portion 21 has a size of, for example, 3.65 × 2.15 mm, For example, 68 × 101 mm
It has the size of As shown in FIG.
A common electrode 3C, a red electrode 3R, a green electrode 3G, and a blue electrode 3B are formed on the front surface 2a of each of the substrate portions 21, and the back surface 2b of each of the substrate portions 21 as shown in FIG.
The electrode 3R for red, the electrode 3G for green, and the electrode 3B for blue are formed, and the electrodes 3R for red on the front and back of each substrate portion 21 are formed.
The green electrode 3G and the blue electrode 3B are connected to each other by through-hole plating 4. Next, as shown in FIG. 1, each of the LED elements 5R, 5G, 5
B is mounted, each LED element 5R, 5G, 5B, etc. is sealed with a convex lens 7 by a method such as printing or transfer molding, and then each substrate section 21 is cut and divided to obtain m × n LEDs. The lamp 1 is manufactured.

FIGS. 4A and 4B show directional characteristics.
In the LED lamp 1, as shown in FIG. 1A, the directional angle (half-value angle) θ of the horizontal direction is increased to 140 degrees by the characteristics of the convex lens 7. In addition, the directional characteristics in the vertical direction include a convex lens 7 as shown in FIG.
Slightly changed due to the influence of the corner 7a.

FIGS. 5A and 5B show the LED lamp 1 of the present invention.
On a printed circuit board. The substrate 2 is placed on the printed circuit board 10 with the end surface 2c facing down, and the common electrode 3C and the common electrode line 11C, the green electrode 3G and the green electrode line 11G, the red electrode 3R and the red electrode line 11R, and the blue color The electrode 3B for blue and the electrode line 11B for blue are connected by the solder 12 respectively. As a result, by passing a current between the electrode lines 11C, 11G, 11R, and 11B, the green light 8G, the red light 8R, and the blue light 8B from each of the LED elements 5R, 5G, and 5B are projected from the convex lens 7.
Are emitted in parallel to the surface of the printed circuit board 10 through.

According to the LED lamp 1 of the first embodiment, the LED elements 5R, 5G and 5B are arranged in a line in a direction orthogonal to the end face 2c, so that the LED elements 5R, 5G and 5B are directed in a horizontal direction between the LED elements. The characteristic deviation is small, and when used as a backlight of a liquid crystal display, color unevenness in the liquid crystal display can be prevented. In addition, since the emitted light of each of the LED elements 5R, 5G, and 5B is shaped and emitted by the convex lens 7, uniform directional characteristics can be obtained. In addition, each LE
Since the convex lens 7 having a focal point behind the light-emitting surfaces of the D elements 5R, 5G, and 5B is used, light is emitted at a wide angle. The light can be easily and uniformly diffused, and the entire liquid crystal display can emit light uniformly. Also, electrodes 3C, 3G, 3R, 3B are formed on the front surface 2a and the back surface 2b of the substrate 2, and the front surface 2a and the back surface 2b are formed.
Electrodes 3G, 3R, and 3B are connected by through-hole plating 4 and the LED elements 5R, 5G, and 5B are arranged at a pitch of 0.5 m so as to have an interval equal to or less than the chip size.
Since they are arranged close to each other by m, the size and weight can be reduced. For example, the size is 3.5 mm wide and 2 m thick
m and a height of 2 mm, and a weight of 0.018 g. In addition, by bringing the LED elements 5R, 5G, and 5B close to each other, color mixing is enhanced, and the LED lamp 1
Height can be reduced, and the light guide plate can be made thin. Also, RG
LED elements 5R, 5G, 5B that emit light of three primary colors B
, So that the display can be made full color when used as a backlight for a liquid crystal display. Further, since the multi-piece substrate 20 is used, the mass productivity is high, and the LED lamp can be manufactured relatively inexpensively.

FIG. 6 shows a side emission type LED lamp according to a second embodiment of the present invention. In the second embodiment, the convex lens 7 is substantially hemispherical. As a result, the directivity in the vertical direction does not change greatly as shown in FIG.

FIG. 7 shows a side emission type LED lamp according to a third embodiment of the present invention. In the third embodiment, the corner 7a of the convex lens 7 is rounded. Thereby, the directional characteristics in the vertical direction can be made uniform.

In the above embodiment, three LEDs are used.
Although the case where an element is used has been described, the present invention can be applied to a case where two LED elements are used. In the above-described embodiment, the combination of the LED elements that emit red, green, and blue light has been described.
LED elements that emit light of other wavelengths (including infrared and ultraviolet) such as 80 nm (purple) and 590 nm (yellow) may be combined. In addition, an LED element having first and second electrodes on an upper surface, a first electrode on an upper surface, a second electrode on a lower surface, and an LED element having first and second electrodes on a lower surface may be used. it can.

[0028]

As described above, according to the side emission type LED lamp of the present invention, since a plurality of LED elements are arranged in a row, deviation of the directivity between the LED elements is reduced, and Since the light emitted from the plurality of LED elements is shaped by the convex lens, uniform directional characteristics can be obtained.
Further, since the front electrode and the back electrode are connected by through-hole plating, downsizing can be achieved.

[Brief description of the drawings]

FIG. 1A is a perspective view of a side emission type LED lamp according to a first embodiment of the present invention as viewed from the front side, and FIG. 1B is a perspective view of the side emission type LED lamp as viewed from the back side.

FIG. 2 is a diagram showing a circuit configuration of the side-emitting LED lamp according to the first embodiment.

3A is a plan view showing a multi-piece substrate according to the first embodiment, FIG. 3B is a front view of a main part, and FIG. 3C is a rear view of a main part seen from the front side.

FIG. 4A is a side view light emitting LED according to the first embodiment.
The figure which shows the horizontal directivity of a lamp, (b) is the figure which shows the vertical direction of the side emission type LED lamp.

FIG. 5A is a side view light emitting LED according to the first embodiment.
A perspective view of the mounting state of the lamp as viewed from the front, and (b) is a perspective view of the mounting state of the side-emitting LED lamp as viewed from the rear.

FIG. 6 is a side view light emitting type L according to a second embodiment of the present invention.
Diagram showing ED lamp and its directional characteristics in the horizontal direction

FIG. 7 is a side view light emitting type L according to a third embodiment of the present invention.
Side view showing ED lamp

FIG. 8A is a perspective view of a conventional side-emitting LED lamp as viewed from the front side, and FIG. 8B is a perspective view showing a mounting state of the side-emitting LED lamp.

FIG. 9 is a diagram showing the directional characteristics of a conventional side emission type LED lamp in the horizontal direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Side emission type LED lamp 2 LED element mounting board 2a Front surface 2b Back surface 2c End surface 2d Side surface 2e Top surface 3B Blue electrode 3C Common electrode 3G Green electrode 3R Red electrode 3a First individual electrode 3b Second individual electrode 3c Common electrode 4 Through-hole plating 4 'Connection plating 5B Blue LED element 5G Green LED element 5R Red LED element 5a First LED element 5b Second LED element 6 Bonding wire 7 Convex lens 8B Blue light 8G Green 8R Red light 8a Light of the first color 8b Light of the second color 10 Printed circuit board 11 Wiring pattern 12 Solder 17 Mold resin 15C Common terminal 15G, 15R, 15B terminal 20 Multi-piece substrate 21 Substrate part

Claims (9)

[Claims] 1. A plurality of LEs arranged in a row on a surface of a substrate.
D element; and the plurality of LEs extending in the column direction of the plurality of LED elements.
A side-emission type LED lamp, comprising: a convex lens provided in common with the D element, the emitted light of the plurality of LED elements being shaped into light having a predetermined spread angle and emitted. 2. The side-emitting LED lamp according to claim 1, wherein the convex lens has a substantially semi-cylindrical shape along the row direction. 3. A side-emitting LED lamp according to claim 1, wherein said convex lens has a substantially hemispherical shape. 4. The side-emitting LED lamp according to claim 1, wherein said convex lens has a focal point behind a light-emitting surface of said plurality of LED elements. 5. The side-emitting LED lamp according to claim 1, wherein said plurality of LED elements include first, second and third LED elements respectively emitting light of different colors. 6. The first LED element is a red LED element that emits red light, and the second LED element is a green LED element that emits green light. 6. The side emission type LE according to claim 5, wherein the third LED element is a blue LED element that emits blue light.
D lamp. 7. The substrate includes a front electrode formed on the front surface, a back electrode formed on a back surface opposite to the front surface, and a through-hole plating connecting the front electrode and the back electrode. The side-emitting LED lamp according to claim 1, wherein the plurality of LED elements are connected to the front electrode. 8. A substrate made of an insulating member, a front electrode formed on the front surface of the substrate, a back electrode formed on the back surface of the substrate, and through-hole plating for connecting the front electrode and the back electrode. And a plurality of LED elements connected to the front electrode. 9. The plurality of LED elements include a first electrode and a second electrode, and the front electrode includes: a plurality of individual electrodes to which the first electrodes of the plurality of LED elements are connected; A common electrode to which the second electrodes of the plurality of LED elements are connected; the back electrode includes a plurality of individual electrodes; and the through-hole plating includes the plurality of individual electrodes of the front electrode and the plurality of individual electrodes. 9. The side-emitting LED lamp according to claim 8, wherein a back electrode is connected to the plurality of individual electrodes.