JPH06310763A - Led lamp - Google Patents

Abstract

PURPOSE:To facilitate the wiring work of a LED by locating a first conductive part on the top face of a flexible board closely to the center thereof whereas locating a second conductive part closely to the periphery thereof. CONSTITUTION:A flexible board 1 is bent to form a tubular body having side faces 5A sectioning the peripheral face into 2n(n>=2) side face parts 5 wherein the 2n-th upper parts are bent at the end face part of the tubular body to provide (n) upper faces 4 forming a substantially identical plane. Conductive patterns 7-14 formed on the flexible board 1 comprise first conductive parts 15-18 formed on each upper face located closely to the center of the plane, and second conductive parts 19-22 formed closely to the periphery of the upper face 4 while being paired with the first conductive parts 15-18. Blue LEDs 42, 43, a red LED 44 and a green LED 45 are mounted at the first conductive parts 15-18 and connected with the second conductive parts 19-22 by a thin metal wire.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a light emitting diode lamp using a plurality of light emitting diodes.

[0002]

2. Description of the Related Art In recent years, many improvements have been made to light emitting diode lamps using a plurality of light emitting diodes. Among them, for example, a light emitting diode lamp filed by the present applicant in Japanese Patent Application No. 4-64547 is shown in a plan view of FIG. In this figure, red, green and blue light emitting diodes 7
1, 72, 73 and 74 are lead frames 75 and
It is mounted on 76, 77, 78. A lead frame 79 is arranged apart from these lead frames to share the anode of each light emitting diode, and is wired to each light emitting diode 71, 72, 73. A thin metal wire 8 is provided between the blue light emitting diode 74 and the lead frame 77.
Wired by 0. A transparent resin 81 is formed so as to cover each light emitting diode.

[0003]

However, in the above-described light emitting diode lamp, the respective light emitting diodes are mounted close to each other in order to improve the luminance characteristic due to the lens effect of the light-transmissive resin 81. Since the blue light emitting diodes 73 and 74 are close to each other in this way, the bonding capillary cannot be inserted between them, which makes it difficult to wire the thin metal wire 80. Therefore, in view of such drawbacks, the present invention provides a light emitting diode lamp in which wiring of each light emitting diode is easy.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a side surface which is bent to form a tubular body and whose peripheral surface is divided into 2n (n ≧ 2) side surface portions. , A flexible substrate having n upper surfaces each of which has an even number side surface portion bent at the end face position of the tubular body to form substantially the same plane, and is located near the center on the plane of the flexible substrate. And a first conductive portion formed on each upper surface, a second conductive portion formed in the vicinity of the periphery of each upper surface in a pair with the first conductive portion, and connected to each first and second conductive portion. A lead portion formed on the side surface portion, a plurality of light emitting diodes mounted on each first conductive portion and wired to each second conductive portion, and a light-transmitting property that covers at least the light emitting diode and the periphery of the upper surface of the flexible substrate. A resin is provided. Then, the predetermined lead portions are connected to each other on the front surface or the back surface of the flexible substrate, and the terminal portion formed to project from the flexible substrate is connected to the end of the lead portion.

[0005]

As described above, according to the present invention, the first conductive portion on the upper surface on which each light emitting diode is mounted is provided near the center of the plane of the flexible substrate, and the first conductive portion is provided near the periphery of the upper surface. Then, the second conductive portion is provided and wiring is performed. Therefore, the respective light emitting diodes can be wired at relatively distant positions, which facilitates the wiring work.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. 1, 2 and 3. FIG. 1 is a plan view of a light emitting diode lamp according to this embodiment, FIG. 2 is a front view thereof, and FIG. 3 is a development view of a flexible substrate used for the lamp. In these figures, the flexible substrate 1 has a thickness of 0.1 to 0.
A conductive pattern is printed on the front and back surfaces of a 2 mm polyimide resin substrate. The flexible substrate 1 is formed by bending a flat plate-shaped substrate 2 at a bending position 3a and bending each upper surface 4 at each side surface portion 5 at a substantially right angle. When viewed from a plane, it is bent into a substantially octagonal tubular shape at the bending position 3b.
This bending is carried out by inserting a prismatic mold under the upper surface 4 of the flat plate-shaped substrate 2 and fitting the mold into the mold from the outside. Adhesive tape 6 near the seam
It is fixed at. As described above, the flexible substrate 1 is bent so as to form a cylindrical body, and the side surface 5A is divided into 2n (n ≧ 2) side surface portions 5 on the peripheral surface thereof, and the end surface position of the cylindrical body is an even number. The n-th upper surface 4 is formed by bending the upper part of the th to form substantially the same plane. In this way, the peripheral surface of the flexible substrate 1 is divided into 2n side surface portions 5, and n is an integer of 2 or more. In the following description, for example, a substantially octagonal cylinder is illustrated with n = 4.

Conductive patterns 7 to 14 made of copper foil or the like are separately formed on the surface of the flexible substrate 1 by printing. On the upper surface 4 of the flexible substrate 1, the conductive patterns 7 to 14 are formed on the upper surface 4 of the first conductive portion 15 and 1 having a relatively large area.
6, 17, 18 and the second conductive portions 19, 20, 21, 22 and the leads 23 to 30 each having a relatively small area in each side surface portion 5 connected thereto. The conductive portions 15 and 19, 16 and 20, 17 and 21, and 18 and 22 are arranged in pairs so as to be adjacent to each other.

The lead portions 24 and 27 are connected by a conductive pattern 33 on the back surface of the flexible substrate 1 via through hole portions 31 and 32, respectively. The lead portions 23 and 25 are connected to the surface of the flexible substrate 1 by a conductive pattern 34, and the lead portions 25 and 29 are through-hole portions 35 and 3, respectively.
Via the conductive pattern 37 on the back surface of the flexible substrate 1.
Connected by. Lead portions 23, 26, 28, 3
0 has terminal portions 38 to 41 formed at the ends opposite to the conductive portions 19, 18, 17 and 16, respectively. Each of the terminal portions 38 to 41 has a copper foil or the like formed on the surface of a polyimide resin, and a copper foil or the like may be formed on the back surface as necessary.

The blue light emitting diodes 42 and 43 are made of, for example, silicon carbide (SiC), and have the first conductive portions 15 and 17, respectively.
It is placed on top of this with silver paste or the like, and is wired to the second conductive portions 19 and 21 by thin metal wires. The red light emitting diode 44 is made of, for example, gallium phosphide (GaP), emits red light having a wavelength of about 700 nm, and emits red light having a wavelength of about 700 nm.
It is placed on top of this with silver paste or the like, and is wired to the second conductive portion 22 by a thin metal wire. Green light emitting diode 4
5 is made of gallium phosphide (GaP), for example, and has a wavelength of about 5
It emits green light of 60 nm and is placed on the first conductive portion 16 via silver paste or the like.
Is wired to.

The light-transmissive resin 46 is made of, for example, epoxy resin or the like, and at least the light emitting diodes 42, 43, 4
4, 45 and the periphery of the upper surface 4 of the flexible substrate 1, preferably the entire flexible substrate 1 is covered, and the tip is dome-shaped. With these parts,
The light emitting diode lamp 47 of this embodiment is configured.

The first conductive portions 15, 16, 17, 1
By arranging 8 near the center on the plane of the flexible substrate 1 and on the upper surface 4 of the flexible substrate 1, the dome-shaped lens effect at the tip of the transparent resin 46 causes Light emitted from the light-emitting diode is condensed near substantially right above the lamp and the luminance in the lateral direction of the lamp is reduced, so that good luminance characteristics can be obtained. Further, the light from different light emitting diodes as in the above-described embodiment has a better color mixing due to the proximity of the light emitting sources. And hopefully each light emitting diode 4
Second conductive portion 1 wired to 2, 43, 44, and 45, respectively
By arranging the positions of 9, 21, 22, and 20 in the peripheral direction of the upper surface 4 of the flexible substrate 1, they are located relatively far from each light emitting diode, which facilitates wiring work.

Next, the circuit of the light emitting diode lamp is shown in FIG.
It will be described with reference to the electric circuit diagram of FIG. In this figure, blue light emitting diodes 42 and 43 are connected in series, and they are connected in parallel with red and green light emitting diodes 44 and 45.
The conductive patterns 33, 34, and 37 provided on the front surface or the back surface of the flexible substrate 1 respectively form the cathode of the blue light emitting diode 42 and the anode of the blue light emitting diode 43, the terminal 38 and the anode of the red light emitting diode 44, and the terminal 38 and the green color. The anode of the light emitting diode is connected. With such wiring, the number of terminals becomes four, and the number of terminals does not increase from the conventional one.

Further, since the forward voltage-current characteristic of each light emitting diode varies, even if two blue light emitting diodes are connected in parallel and the same voltage is applied, the current flowing through each light emitting diode varies. Therefore, the brightness of each blue light emitting diode is also different, and as a result, the way in which the emitted colors are mixed deteriorates, so it is better to connect the blue light emitting diodes in series.

Next, a second embodiment will be described with reference to FIG. 5, in which the light emitting diode can be more reliably maintained in a horizontal position than the light emitting diode lamp of the first embodiment. FIG. 5 is a plan view of the flexible substrate 48 used in the light emitting diode lamp of this embodiment. In the vicinity of the bending position 49 of the flexible substrate 48,
The conductive portions 15a to 22a and the lead portions 23a to 30a are formed wider than those of the first embodiment. Therefore, since the strength of the bent portion is increased, the amount of spring back (bending back) after bending is reduced, and the upper surface 4 with respect to each side surface portion 5a is reduced.
The bending angle of 90 ° in a is maintained, and each light emitting diode is reliably maintained in a horizontal position. As a result, variations in the brightness characteristics of the individual light emitting diodes are reduced.

A third embodiment in which the mounting is improved as compared with the above-mentioned embodiment will be described with reference to the external view of FIG. Flexible substrate 5
The bottom side 51 of 0 is formed so as to project outward from the bottom surface of the translucent resin 46. Then, the terminals 53 to 5 are provided on the circuit board 52.
5 is inserted and the bottom side 21 of the flexible substrate 50 is brought into contact with the surface of the circuit board 52, which is effective when it is desired to use the light emitting diode lamp away from the circuit board 52.

Next, a fourth embodiment suitable for surface mounting will be described with reference to the external view of FIG. The terminal portion 57 of the flexible substrate 56,
Reference numerals 58 and 59 are formed by bending the bottom surface 60 of the translucent resin 46 at a substantially right angle. Therefore, it can be mounted on the surface of the circuit board 61, the labor for inserting terminals and the like can be saved, and the fixing work time can be shortened.

[0017]

As described above, according to the present invention, the first conductive portion on the upper surface on which each light emitting diode is mounted is provided near the center of the plane of the flexible substrate, and the first conductive portion is provided near the periphery of the upper surface. The second conductive portion is provided in a pair with and is wired. Therefore, the respective light emitting diodes can be wired at relatively distant positions, which facilitates the wiring work.

Further, by connecting the predetermined lead portions connected to the first and second conductive portions to each other on the front surface or the back surface of the flexible substrate, the number of terminals for connecting to an external circuit is increased as compared with the conventional one. Absent.

[Brief description of drawings]

FIG. 1 is a plan view of a light emitting diode lamp according to a first exemplary embodiment of the present invention.

FIG. 2 is a front view of a light emitting diode lamp according to a first embodiment of the present invention.

FIG. 3 is a development view of a flexible substrate used in the light emitting diode lamp according to the first embodiment of the present invention.

FIG. 4 is an electric circuit diagram of a light emitting diode lamp according to a first embodiment of the present invention.

FIG. 5 is a development view of a flexible substrate used in a light emitting diode lamp according to a second embodiment of the present invention.

FIG. 6 is an external view of a light emitting diode lamp according to a third embodiment of the present invention.

FIG. 7 is an external view of a light emitting diode lamp according to a fourth embodiment of the present invention.

FIG. 8 is a plan view of a conventional light emitting diode lamp.

[Explanation of symbols]

1 flexible substrate 15, 16, 17, 18 first conductive portion 19, 20, 21, 22 second conductive portion 23, 24, 25, 26, 27, 28, 29, 30 lead portion 42, 43, 44, 45 light emitting diode 46 translucent resin

Claims (1)

[Claims] 1. A side surface which is bent so as to form a tubular body and whose peripheral surface is divided into 2n (n ≧ 2) side surface portions, and an upper portion of each even side surface portion at an end face position of the tubular body. A flexible substrate having n upper surfaces that are bent to form substantially the same plane, a first conductive portion formed on each upper surface near the center of the plane of the flexible substrate, and A second conductive portion formed in the vicinity of the periphery of each upper surface in a pair with the first conductive portion;
Lead portions connected to each of the first and second conductive portions and formed on each of the side surface portions, and a plurality of light emitting diodes mounted on each of the first conductive portions and wired to each of the second conductive portions, At least the light emitting diode and a transparent resin that covers the upper surface of the flexible substrate are provided, the predetermined lead portions are connected to each other on the front surface or the back surface of the flexible substrate, and the terminal portion is A light emitting diode lamp, which is connected to an end of a lead portion and formed so as to project from the flexible substrate.