TWI469113B - Led color point-light source being applied to dot-matrix advertisement board - Google Patents

Description

Light-emitting diode color point light source structure and manufacturing method thereof are applied to a wide dot matrix Notice board

The invention relates to a light-emitting diode advertising light source, in particular to a color point light source structure and a manufacturing method thereof.

The issue of energy conservation and carbon reduction and the issue of dual-fuel oil and gas have recently become feverish. Traditional incandescent lighting has withdrawn from the market, and relatively light-emitting diodes (LEDs) with cold light sources and power-saving characteristics have gradually expanded their market share. As a result, LED prices have become very close to the people and have been widely used in signal LEDs, such as the front and rear lights of cars, traffic lights, etc. The common feature of these lights is that the LED monochromatic point source is provided with a plurality of perforated substrates, and each through hole can be embedded with a little light source.

LED monochrome point light sources can also form an advertising sign pattern. A substrate may be provided with a pattern of perforations. Then, each through-hole is embedded in an LED monochromatic point source. The patterned point source can be signaled to control its bright or non-brightness, that is, the pattern can be changed by different single-color LEDs in different positions of the pattern, or at the same time, even if it is a matrix pattern, it can be changed. The pattern and text to be displayed. In this way, you can replace some of the neon lights. However, the advertising lights are represented by LED monochromatic point sources, which are still monotonous.

Therefore, it is still limited to really implement the replacement of neon lights. Those who need to change the advertising content from time to time are still mainly kanbans composed of liquid crystal displays of color thin film transistors. LED chips, up to the role of backlight. However, the price of the liquid crystal display is high, and when the liquid crystal display is installed outdoors, the breakage rate is also high, so it is limited to some crowd gathering points or rooms used in public places. Inside the board.

Due to the above problems, the point light source composed of the basic three primary colors and the LED color point light source expressing the color by the control signal are gradually paid attention to, which can be close to the change pattern of the liquid crystal display kanban. When used in outdoor attractions, it does not require much maintenance. As a result, more and more advertising signs have attempted to switch to advertising billboards made up of LED color point sources.

However, the conventional LED monochrome point light source includes an LED surface-mounted component (SMD) (a substrate or a LED lamp cup and a rubber sleeve). The SMD substrate comprises a single LED chip, optionally comprising a parallel Zener diode, and the SMD substrate has two contacts for wiring. LED lamp cup refers to the lamp cup that attaches the LED chip to one or two legs. Regardless of whether it is the former or the latter, it is necessary for the operator to hold the tin wire with ferrochrome, supplemented by a robot arm, and connect the output to the power cord by spot welding.

However, the conventional LED color point light source is more complicated. As shown in FIG. 2, the surface containing the three LED chips is next to the SMD (the substrate or the LED lamp cup and the rubber sleeve. The SMD substrate contains red, green, Blue three LED chips, one Zener diode, three LED chips of red, green and blue need three input and three output and at least one control signal line. However, whether it is LED color or monochrome point source surface adhesion The SMD substrate does not increase the number of different color pads of the LED, and the number of signal lines increases, and the area of the contact is increased by several times, which only increases the man-hour of manual work.

It is assumed that the SMD substrate of the monochromatic LED is only about 7 mm (the LED chip itself is 3 mm or less) or less, which makes it difficult for the operator to spot-weld the LED. The color LED point light source has 6 to 8 wires as described above. In other words, if the spot welding is still performed by the operator in the manner of treating the single-color LED point light source as described above, the wire-welding SMD pin should be performed in a very small working space due to the increase in wiring and the small terminal pitch. . Short soldering, or short-circuiting of wires due to overflow of tin, is almost inevitable unless the operation of colored point sources is increased space. This in turn makes the display quality of the advertisement display thicker. Therefore, it is not surprising that the yield is low and the cost is high.

In view of the above, it is an object of the present invention to provide a technique to overcome the difficulties of the prior art.

The object of the present invention is to provide an LED point light source structure, which is designed to fit a flexible printed circuit board and an SMD LED to solve the problem of low efficiency of the conventional artificial welding wire.

A further object of the present invention is to provide a color LED point light source structure, which is designed to be attached to a SMD by a flexible printed circuit board to solve the problem of difficulty and low yield of the conventional artificially welded wire on the SMD.

The color LED point light source structure disclosed by the invention comprises: a monochromatic or trichromatic SMD LED patch on an FPC (soft printed circuit board); and a long strip of plastic film sleeve directly bonding the SMD LED and the FPC patch One-piece package.

The present invention also provides a method of fabricating a color LED point source structure, first providing a SMD LED of a single color or a three primary color, followed by a soft printed wiring board on which a copper foil line is exposed at one end, and solder is printed on the copper foil. The patch is applied by SMTM before the solder is cured, and finally, the patch portion is directly packaged by forming a tantalum film sleeve or a plastic film sleeve by press-molding or injection molding.

In view of the prior art, whether a monochromatic LED point source or a color LED point source is completed by wire spot welding. In particular, LED color point light sources are produced by conventional methods, and the low yield and high cost make it difficult to be widely used. this The inventive method can solve this problem.

Please refer to the flowchart shown in FIG. 1 at the same time, the FPC diagram of FIG. 2 and the cross-sectional diagram of FIG. 3A. First, an SMD (surface mounted device) LED 300 is provided as shown in step 100. In one implementation, the SMD 300 is only monochromatic and has a Zener (Zener diode) in parallel. In this case, the SMD LED has only one pin in and out. In another implementation, the SMD is to provide a color point source. An SMD has three LEDs of three primary colors of R/G/B and three Zener connected in parallel. In another implementation, the color point source SMD LED has a point control IC (integrated circuit) in addition to the aforementioned three LEDs of R/G/B and three Zeners. The point control IC controls R/G/B to select the light or dark of that one, so there will be four in and four out signal lines.

Next, the SMD LED is patched by the placement machine as shown in step 120. Here, it is meant that the FPC flexible printed circuit board is quickly bonded by a SMTM (surface mounted technologic machine) (not shown) or a placement machine. In this step, the FPC line is pre-made in a copper foil pattern according to one in one, three in three out, or four in and four out in the SMD 200 in step 100. That is, the entire copper foil is first pressed on an insulating soft dielectric material (dielectric), and the soft dielectric material may be a polyimide film (PI) film, a polyester (PE) film, or a polyethylene naphthalate. One of ester film (PEN) or polyamide fiber paper, and the like. Then, the ink is used as a mask to etch into the desired line and quantity. Then, the flexible copper foil is overlaid on the etched copper foil, but the copper foil pattern remaining with the SMD LED bonding portion is not covered. Finally, cut again. The cut flexible circuit board FPC is shown in Figures 2A, 2B, and 2C. The printed circuit boards are shown as 1 in 1 out or 3 in 3 out. Each segment of the FPC 200 has a copper foil bare pattern 220 that is reserved for mating with SMD LED pins.

In a fully automated or semi-automated step, the SMTM will first print half of the liquid solder paste on the FPC 200 copper foil exposed pattern 220 (warm to 240 ° C) and then attach the FPC to the SMD LED.

In a typical example, SMTM can fit 5 to 6 per second. There is no known manual technique that may cause cold soldering, soldering, and soldering. The present invention incorporates FPC 200 and SMD LED 300 with SMTM as described above. The semi-liquid solder paste is brushed in a fully automated or semi-automated step, and therefore, there is no difference in color and color. The method of soldering a wire, the yield is acceptable in a monochrome LED point source, but the manufacturing of a color LED point source is generally low, so the method of the present invention is reliable and extremely efficient compared to the present invention. very obvious.

Then, as shown in step 150, the silicone rubber 350 is pressed or plastic injection molding, and the module on which the SMD LED 300 is attached to the FPC 200 is once packaged into a strip having the brim 340 by injection molding. Shape or called bullet-shaped LED point source product 350. Silicone rubber has quite good weatherability: it contains water, acid in the air, alkali atmosphere, sun exposure, etc. Another case is that the encapsulating material is plastic. The advertising lights are mostly installed outdoors. Therefore, adding anti-ultraviolet additives to the plastic granules can delay the problem of aging and aging of the plastic lamps.

In another variation, after the SMD 300 is attached to the exposed terminal 220 on the FPC 200, it will be inserted into the molded silicone sleeve or the plastic mold sleeve, and then inserted into the bottom with the plug 360. The result is shown in FIG. 3B. Shown.

Fig. 4A is a perspective view showing the appearance of an LED color point source. FIG. 4B is a perspective view showing the appearance of the LED color point light source being inserted into the advertising board 400. The protruding portion 340 of the silicone mold sleeve or the plastic mold sleeve is caught on the through hole.

The LED color point light source of the invention is mostly 15 series connected, mainly because the common advertising lamp voltage is 48V. Since each LED in the SMD is connected in parallel with a ZENER diode, don't worry that if one of the LEDs fails, the entire LED will be blind.

The LED color point source structure and method of the invention has the following advantages:

1) It is to put the SMD LED on the FPC, and the FPC itself has a circuit pattern. With SMTM machine patches, the efficiency is increased hundreds of times compared to the conventional manual soldering of wires between two to dozens of LEDs.

2) Use FPC instead of wire to make the connection of a series of dozens of LED point light sources more refreshing.

3) SMD LED patch is re-formed on the silicone mold sleeve or plastic mold sleeve in FPC, instead of inserting the rubber plug into the plastic mold sleeve, it is equivalent to one less work.

4) The finished product is stable and reliable, and there is no problem of cold welding, cold welding and overflowing of SMD LED and wire connection.

Although the present invention has been described above by way of preferred examples, it is not intended to limit the present invention. The inventive concept and the inventive entity are only limited to the above embodiments. Those who are familiar with the technology can easily understand and utilize other components or methods to produce the same effect. Modifications made without departing from the spirit and scope of the invention are intended to be included within the scope of the appended claims.

100, 120, 150‧‧‧ flowchart steps

200‧‧‧ (soft printed circuit board) FPC

220‧‧‧FPC for fitting to the terminal of SMD LED

300‧‧‧SMD (Surface Adhesive Element) LED

350‧‧‧矽plastic sleeve or plastic sleeve

360‧‧‧plug

400‧‧‧Advertising board

340‧‧‧矽 plastic sleeve or plastic sleeve like the protrusion of the cap

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow chart of the manufacturing method of the present invention.

2A, 2B, and 2C respectively show schematic diagrams of a flexible printed circuit board to which a monochrome, color, and control signal SMD point source is fabricated in accordance with the present invention.

3A and 3B respectively show cross-sectional views of a point source manufactured in accordance with the present invention.

4A and 4B are respectively a perspective view of a point source manufactured in accordance with the present invention and a perspective view mounted to the billboard.

200‧‧‧ (soft printed circuit board) FPC

300‧‧‧SMD (Surface Adhesive Element) LED

220‧‧‧FPC for fitting to the terminal of SMD LED

350‧‧‧矽plastic sleeve or plastic sleeve

340‧‧‧矽 plastic sleeve or plastic sleeve like the protrusion of the cap

Claims (10)

An LED point light source structure applied to a dot matrix advertising billboard, comprising: an SMD LED (LED surface mounted device) mounted on an FPC (soft printed circuit board); and a glue The film sleeve encloses the SMD LED and the FPC patch, and the film sleeve can be fitted into one of the through holes of the dot matrix billboard. The LED point light source structure applied to the dot matrix advertisement billboard according to claim 1, wherein the SMD LED is an SMD of a monochrome LED wafer. The LED point light source structure applied to the dot matrix advertisement billboard according to claim 1, wherein the SMD LED is an SMD of a three primary color LED chip, and has a power line of three inputs and three outputs. The LED point light source structure applied to the dot matrix advertising billboard according to the first aspect of the patent application, wherein the SMD LED is a SMD of a three primary color LED chip, and has a power line of four in and four out, wherein one of the wires is one in and one out. The signal line of the point control integrated circuit is three-in and three-out for the power line of the three primary color LEDs. The LED point light source structure applied to the dot matrix advertisement billboard according to claim 1, wherein the rubber film sleeve is one of a bullet-shaped silicone rubber sleeve or a plastic film sleeve with a brim, and the brim is The film sleeve is engaged with the advertising light board when it passes through the hole in the advertising light board. A manufacturing method of an LED point light source for advertising for a dot matrix advertising billboard comprises at least the steps of: providing an SMD LED; forming a flexible printed circuit board, one end of which is exposed to the SMD terminal of the flexible printed circuit board Solder bonding Printing solder on bare copper foil, and bonding SMD LED and soft printed circuit board with SMTM while solder is still uncured; forming a film sleeve by press-molding to package the SMD LED and soft printing The bonding portion of the circuit board and the bonding portion of the SMD LED and the flexible printed wiring board are simultaneously heated at the time of forming to strengthen the bonding portion. The method for manufacturing an LED point light source for advertising, which is applied to a dot matrix advertisement billboard according to the sixth aspect of the invention, wherein the SMD LED is a three primary color point light source. The method for manufacturing an LED point light source for advertising, which is applied to a dot matrix advertisement billboard according to the sixth aspect of the invention, wherein the SMD LED comprises an LED primary color and a point control IC. The method for manufacturing an LED point light source for advertising used in a dot matrix advertisement billboard according to the sixth aspect of the invention, further comprising forming one of a silicone film sleeve or a plastic film sleeve by an injection molding method. A manufacturing method of an LED point light source for advertising for a dot matrix advertising billboard comprises at least the steps of: providing an SMD LED; forming a flexible printed circuit board, one end of which is exposed to the SMD terminal of the flexible printed circuit board Solder bonding; printing solder on bare copper foil, and simultaneously bonding SMD LED and the flexible printed circuit board with SMTM while the solder is still uncured; providing a film sleeve; a bonding portion of the SMD LED on the flexible printed circuit board is inserted into the film sleeve; the bonding portion is fixed to the bonding portion by a plug The film sleeve.