WO2008126953A1

WO2008126953A1 - Led module for signboard

Info

Publication number: WO2008126953A1
Application number: PCT/KR2007/001907
Authority: WO
Inventors: Joung-Woong Cho; Hyo-Sik Jeon
Original assignee: Joung-Woong Cho; Hyo-Sik Jeon
Priority date: 2007-04-17
Filing date: 2007-04-19
Publication date: 2008-10-23
Also published as: KR100780704B1

Abstract

A LED module comprising: a LED package device including a circuit board, a LED chip mounted on the circuit board, a LED driving circuit portion for driving the LED, and a pair of leads extending downward for supplying current to the LED chip; a base plate in the form of strip having a pair of insertion grooves formed in parallel to each other for receiving the pair of leads; and a conductive thin film attached to the insertion grooves for connecting to the leads of the LED package devices.

Description

Description LED MODULE FOR SIGNBOARD

Technical Field

[1] The present invention relates to a LED module for signboard, more particularly to a

LED module for a signboard using a LED circuit board which makes the manufacture of a signboard easier by simplifying an assembly of a LED package onto a base board instead of a PCB (Printed Circuit Board), which decreases the manufacturing cost while increasing manufacturing efficiency.

[2]

Background Art

[3] In general, a signboard is illuminated using various lighting means to increase the effect of advertisement. Typical lamps such as a fluorescent lamp and a neon lamp are used as the lighting means. Recently, a lighting means using a LED is widely used. Since a LED has advantages of a long lifespan and a high efficiency, its usage is broad ened to lighting and display devices.

[4] A manufacture of LED includes the steps of manufacturing chips from the wafers such as sapphire and GaN, packaging the chips by molding to a LED package, and assembling lamps for headlight or BLU (back light unit) using the LED packages.

[5] Also, the LED is used to a lighting means for the signboard. FIG. 1 shows a LED module for the signboard of surface mount devices type. As shown in FIG. 1 , the conventional LED module comprises a PCB 001, and LED package devices surface- mounted on the PCB 100.

[6] The PCB 100 has circuits of thin conductive layer formed thereon, LED packages

101 and devices 103 such a resistance mounted on the PCB 100 to connect with terminals.

[7] Electrodes 102 are provided on the ends of the LED circuit board 100 for the supply of current, which are electrically connected to the adjacent LED module by a connector 2.

[8] In the conventional LED module for signboard, the cost of manufacturing LED packages 101 decreases because of mass production and high efficiency of production. However, it is limited to decrease the cost of manufacturing PCB 100 due to complicated process.

[9] According to the inventor's study, the production cost of LED module having 9

LEDs possesses 50:50 of the LED package to PCB at present. However, it is expected that the LED package will be 15~20% of the whole cost, while the PCB will cost more than 80% in the near future. [10] Also, the conventional LED module is restricted in size because the surface- mounting area is restricted. According to the conventional method of manufacturing LED module, a PCB of square is supplied and surface-mounted with LED packages and other driving devices by a surface-mounting apparatus, and then the PCB is cut in the vertical direction to thereby obtain a LED module in the form of strip.

[11] Accordingly, the length of the LED module is limited to the original PCB, which cannot meet the needs that the longer LED module should be provided corresponding to the signboard.

[12] Therefore, there should be provided a LED module capable of replacing the conventional LED module.

[13]

Disclosure of Invention Technical Problem

[14] The present invention is designed to solve the above problems of the prior art. It is an object of the invention to provide a LED module which lowers production cost of a LED module by adopting a base plate made of synthetic resins instead of PCB.

[15] Another object of the present invention is to provide a LED module of which length may not be restricted so as to meet the customer's demands.

[16] Still another object of the present invention is to provide a LED module by which the interval between the LED package devices may be adjusted depending on the specification of signboard to provide flexibility of design due to the intensity of light.

[17]

Technical Solution

[18] In order to accomplish the above object, the present invention provides a LED module comprising: a LED package device including a circuit board, a LED chip mounted on the circuit board, a LED driving circuit portion for driving the LED, and a pair of leads extending downward for supplying current to the LED chip; a base plate in the form of strip having a pair of insertion grooves formed in parallel to each other for receiving the pair of leads; and a conductive thin film attached to the insertion grooves for connecting to the leads of the LED package devices.

[19] Preferably, the insertion grooves have slanted surfaces at both sides so that the conductive thin films are attached to the slanted surfaces in the lengthwise direction.

[20] More preferably, the insertion grooves have a rest portion at the bottom on which the leads rest, and wherein ends of the conductive thin films contact each other at the rest portion so that the leads are interposed between the ends of the conductive thin films to be supported.

[21] According to the present invention, the base plate comprises fastening brackets for receiving a fastener.

[22] Also, the base plate may be made of flexible synthetic resins.

[23] Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Advantageous Effects

[24] According to the present invention, since the base plate is made of inexpensive synthetic resins, the cost of manufacturing the LED module can be decreased. [25]

Brief Description of the Drawings [26] These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which.

[27] FIG. 1 is an exploded perspective view showing the conventional LED module;

[28] FIG. 2 is a sectional view schematically showing a LED package device adopted by a LED module according to the preferred embodiment of the present invention; [29] FIG. 3 is an exploded perspective view schematically showing the configuration of a LED module according to the preferred embodiment of the present invention; [30] FIG. 4 is a sectional view schematically showing a base plate included in a LED module according to the preferred embodiment of the present invention; [31] FIG. 5 is a schematically sectional view showing a base plate mounted with LED package devices according to the preferred embodiment of the present invention; [32] FIG. 6 is an exploded perspective view showing a LED module according to the preferred embodiment of the present invention; [33] FIG. 7 is an exploded perspective showing a base plate adopted in a LED module according to another preferred embodiment of the present invention. [34]

Best Mode for Carrying Out the Invention [35] FIG. 2 shows schematic configuration of a LED package device 200 adopted by a

LED module according to the preferred embodiment of the present invention. [36] Referring to the drawings, a LED package device 200 comprises a circuit board 210, a LED chip 220 mounted on the circuit board 210, and a LED driving circuit portion

230 for driving the LED. [37] A pair of leads 240 and 241 extends downward form both ends of the circuit board

210 for supply of current. [38] The LED driving circuit portion 230 consists of devices that drive the LED with the current supplied by the leads 240 and 241. For example, the LED driving circuit portion 230 may be a resistance for applying an appropriate voltage, a switching device for generating a square wave signal with respect to the supplied current, and a filter for converting the current supplied by the switching device to a constant current. The configuration and operation of the LED driving circuit portion 230 is well known in the art and then will be omitted.

[39] A convex lens 250 for focusing a light is provided above the LED chip 220. Also, the above devices are mold by conductive silicon.

[40] FIG. 3 illustrates a LED module adopting the LED package device having the above configuration.

[41] Referring to the drawing, a LED module according to the preferred embodiment of the present invention comprises a base plate 300 in the form of strip, and LED package devices 200 mounted on the base plate 300.

[42] The base plate 300 is a strip made of ABS resin, PVC, polycarbonate (PC), polypropylene (PP), polyethylene (PE), and the like. The base plate 300 is not formed with circuits made of copper clad laminate but extruded from typical synthetic resins.

[43] As shown in FIG. 4, the base plate 300 has a pair of insertion grooves 310 parallel to each other. As set forth later, the LED package devices 200 are connected to the insertion grooves 310, so that the distance W2 between the insertion grooves 310 is the same as the distance Wl between the leads 240 and 241 of the LED package devices 200.

[44] Referring to the drawing, the insertion grooves 310 has slanted surfaces 311 and 312 at both sides to facilitate the insertion of the leads 240 and 241 of the LED package devices 200. Also, the insertion grooves 310 include a rest portion 313 at the bottom for the ends of the leads 240 and 241 of the LED package devices 200 to rest on.

[45] According to the present invention, conductive thin films 340, preferably copper film are attached to the insertion grooves 310 for supply of the current. The conductive thin films 340 are electrically connected to the electrodes (see 330 of FIG. 3) at both ends of the base plate 300.

[46] More preferably, the conductive thin films 340 are attached to the slanted surfaces of the insertion grooves 310 in the lengthwise direction, of which ends contact each other at the rest portion 313.

[47] FIG. 5 shows a sectional view in which LED package devices 200 are mounted on the base plate 300.

[48] As shown in the drawing, when the leads 240 and 241 of the LED package devices

200 are inserted into the insertion grooves 310 for connection, ends of the leads 240 and 241 are guided along the conductive thin films 340 attached to the slanted surfaces 311 and 312 of the insertion grooves 310 to the rest portion 313.

[49] Subsequently, the leads 240 and 241 are inserted more to the rest portion 313, and the leads 240 and 241 rest on the rest portion 313 while ends of the conductive thin films 340 are elastically deformed so that leads 240 and 241 are supported with interposed between the ends of the conductive thin films 340. Accordingly, the LED package devices 200 are fixed not to move in the insertion grooves 310.

[50] Such insertion of the LED package devices 200 into the insertion grooves 310 of the base plate 300 may be conducted by the surface-mounting apparatus.

[51] FIG. 6 shows a LED module in which the LED package devices 200 are mounted on the base plate 300.

[52] The LED module manufactured as set forth above is installed on the frame of the signboard to emit light. Preferably, the base plate 300 has fastening brackets 320 to be fixed to the frame of the signboard by using a fastener such as a bolt.

[53] Alternatively, the base plate 300 may be directly installed to the frame of the signboard by screwing the bolt. The configuration of the base plate 300 not having copper clad laminate makes it possible to directly connect the base plate by screwing.

[54] FIG. 7 shows a base plate 300' of another preferred embodiment of the present invention. The base plate 300' made of flexible synthetic resins is wired about a roller.

[55] Like the above embodiment, the base plate 300' has a pair of insertion grooves 310' parallel to each other on the upper surface thereof. Conductive thin films 311 are attached to slanted surfaces of the insertion grooves 310'. The configuration of the insertion grooves 310' and the conductive thin films 311' is the same as the previous embodiment, and then will be omitted.

[56] According to the LED module of the present invention, since the base plate 300' is supplied from the roller, the length of the LED module may be selected as desired.

[57]

Industrial Applicability

[58] The LED module of the present invention has the following advantages.

[59] First, since the base plate is made of inexpensive synthetic resins, the cost of manufacturing the LED module can be decreased.

[60] Second, the LED package devices are mounted onto a pair of insertion grooves in the unilateral direction by the surface-mounting apparatus, which removes the limit of mounting devices as prior art.

[61] Third, the LED package devices can be mounted at an appropriate position in the lengthwise direction of the insertion grooves as desired. That is, the LED package devices are connected at short interval for obtaining high intensity of light, while the LED package devices are spaced from each other at long distance for low intensity of light.

[62] Fourth, since the insertion grooves have slanted surfaces, the leads of the LED package devices are easily inserted into the insertion grooves in spite of inaccuracy of assembly, which makes errors of manufacture to decrease.

Claims

[1] A LED module comprising: a LED package device including a circuit board, a LED chip mounted on the circuit board, a LED driving circuit portion for driving the LED, and a pair of leads extending downward for supplying current to the LED chip; a base plate in the form of strip having a pair of insertion grooves formed in parallel to each other for receiving the pair of leads; and a conductive thin film attached to the insertion grooves for connecting to the leads of the LED package devices.

[2] The LED module according to claim 1, wherein the insertion grooves have slanted surfaces at both sides so that the conductive thin films are attached to the slanted surfaces in the lengthwise direction. [3] The LED module according to claim 2, wherein the insertion grooves have a rest portion at the bottom on which the leads rest, and wherein ends of the conductive thin films contact each other at the rest portion so that the leads are interposed between the ends of the conductive thin films to be supported. [4] The LED module according to claim 1, wherein the base plate comprises fastening brackets for receiving a fastener. [5] The LED module according to claim 1, wherein the base plate is made of flexible synthetic resins.