WO2020191826A1

WO2020191826A1 - Transparent led display screen

Info

Publication number: WO2020191826A1
Application number: PCT/CN2019/082824
Authority: WO
Inventors: 林富; 林谊
Original assignee: 深圳市晶泓科技有限公司
Priority date: 2019-03-28
Filing date: 2019-04-16
Publication date: 2020-10-01
Also published as: CN110033711A

Abstract

In order to overcome the problems in the transparent LED display screens in the prior art that forming a transparent conductive material for power supply on a transparent substrate as a power supply circuit by means of the printing process cannot make the spacing between the LED lamp beads small or improve the resolution of the transparent LED display screen; and that the transparent conductive material would also reduce the transparency of the transparent substrate to a certain extent, the present invention provides a transparent LED display screen, in which the mode of combining metal wires allowing a larger current with a bonding pad provided on a transparent substrate is used for supplying power to each LED lamp bead instead of printing the transparent conductive material on the transparent substrate, so as to further reduce the interval between the LED lamp beads and improve the resolution. In addition, the metal wire has a smaller diameter only blocks the line of sight slightly, so that high transparency can be ensured.

Description

A transparent LED display

Technical field

The present invention relates to the field of LEDs, in particular to the field of transparent LEDs.

Background technique

Transparent LED displays have gradually been widely used in the market, and various product forms have been developed. A transparent LED display technology in which LED lights are arrayed on a transparent substrate has begun to appear. This technology generally uses transparent conductive materials, such as metal mesh (metal mesh), nano silver, ITO, etc., but because the thickness of the above-mentioned materials attached to the transparent substrate is very thin, and the current demand for LED operation is relatively large. The material is difficult to meet the power supply requirements of the LED, especially when the LED array is densely arranged (the LED lamp spacing is less than 10mm), it is difficult to meet the power supply requirements of the entire screen. In addition to power supply, the work of LED lights also requires signal input control. Therefore, the connection of communication signal lines is required between LED lights, which will cause the circuit division on the substrate to be more complicated, thereby reducing the line area of the power supply part and increasing the resistance. Big. Although there are also technical solutions to encapsulate the driver IC in the LED lamp, thereby reducing the complexity of the circuit, at least one or two signal lines between the LED lamps are required. In the case of densely arranged LED lamps, the circuit After the graphics layer is divided, it still cannot meet the demand for power supply.

For example, as shown in Fig. 1, there is currently provided an improved transparent LED display screen, which includes a transparent substrate, a printed circuit layer is provided on the transparent substrate, and a chip-encapsulated LED lamp bead array is mounted on the transparent substrate. On the substrate; as shown in Figure 2, specifically, the printed circuit layer includes lamp bead welding area, power supply pad and signal pad, etc., the lamp bead welding area is provided with 4 LED lamp lead In addition, there are two signal pin pads and two electrode pin pads in each lamp bead welding area. The signal pin pads are connected in series through printed signal lines, and the polarity is opposite The two electrode pin pads are respectively supplied with power through the metal grid 30 printed on the transparent substrate.

This method has a certain advantage that the metal grid 30 for power supply can be directly formed on the transparent substrate through the printing process as a power supply circuit; however, since the thickness of the printed pattern layer is generally only about 35 microns, the formed metal grid 30 The current that each metal wire can carry is very small, especially when the LED lamp bead spacing is less than 8mm, the metal grid 30 has a width of less than 4mm after being divided, and its power supply capacity is quite weak, which cannot make the LED lamp bead If the pitch of the transparent LED display is made smaller, the resolution of the transparent LED display cannot be improved; and in order to increase the conductivity, the metal mesh 30 mesh made of small metal wires will reduce the transparency of the transparent substrate to a certain extent.

Summary of the invention

In order to overcome the fact that the transparent LED display in the prior art adopts a printing process to form a power supply metal grid on the transparent substrate as the power supply circuit, the distance between the LED lamp beads cannot be made small, and the resolution of the transparent LED display cannot be reduced. Improve; and the metal grid will reduce the transparency of the transparent substrate to a certain extent. The present invention provides a transparent LED display.

The present invention provides a transparent LED display screen, including a transparent substrate and LED lamp beads; the LED lamp beads include a bracket, a driving chip and a light-emitting chip formed on the bracket; and a number of pins are also provided on the LED lamp beads , The pins include electrode pins and signal pins;

A printed circuit layer is arranged on the transparent substrate; the printed circuit layer includes power supply pads, signal pads and lamp bead welding areas arranged in an array for mounting LED lamp beads;

Each of the lamp bead welding areas is provided with a pin pad corresponding to the pin of the LED lamp bead; the pin pad includes a signal pin pad and an electrode pin pad; each of the electrodes There is an extension part on the lead pad;

A signal line for signal transmission is provided between the signal pad and the signal pin pad in the lamp bead welding area, and between the signal pin pads in the adjacent lamp bead welding area of the same row or the same column; The control signal for each LED lamp bead to turn on and off can be transmitted sequentially through each LED lamp bead after being input from the signal pad;

The extension part of the electrode pin pad on the lamp bead welding area is electrically connected with the power supply pad of the same polarity through metal wire welding.

The transparent LED display provided by the present invention adopts a method of combining a metal wire with a higher current and a pad set on the transparent substrate to replace the metal grid printed on the transparent substrate to supply power to each LED lamp bead. , So that it can further reduce the spacing between the LED lamp beads, improve its resolution, at the same time, the smaller diameter of the metal wire to the line of sight is also relatively small, can ensure extremely high transparency.

Further, N rows*M columns of lamp bead welding areas are provided on the printed circuit layer;

M signal pads are arranged on the printed circuit layer; the M signal pads and the signal pin pads in the N lamp bead pads in the same column are serially connected in sequence through signal lines;

Alternatively, N signal pads are arranged on the printed circuit layer; the N signal pads and the signal pin pads in the M lamp bead welding areas on the same line are sequentially connected in series through signal lines.

Further, M pairs of power supply pads or N pairs of power supply pads are arranged on the printed circuit layer; each pair of power supply pads includes a first power supply pad and a second power supply pad with opposite polarities;

The electrode pin pad includes a first electrode pin pad and a second electrode pin pad; a first epitaxial portion is drawn on the first electrode pin pad; the second electrode pin pad There is a second extension part on the top lead;

The first extension part of the first electrode pin pads on the N lamp bead pads on the same column and the first power supply pad of the same polarity are electrically connected by a first metal wire; the lamps on the same column The second extension part of the second electrode pin pad on the bead welding area is electrically connected to the second power supply pad of the same polarity through the second metal wire welding; or, the M lamp bead welding areas on the same line The first extension part of the first electrode lead pad on the upper side is electrically connected to the first power supply pad of the same polarity through the first metal wire welding; the second electrode on the lamp bead welding area on the same column The second extension part of the pin pad is electrically connected to the second power supply pad of the same polarity through a second metal wire welding.

Further, M+1 power supply pads or N+1 power supply pads are arranged on the printed circuit layer;

The M+1 power supply pads or N+1 power supply pads include first power supply pads and second power supply pads with opposite polarities arranged at intervals;

The first extension part of the first electrode pin pads on the N lamp bead pads on the same column and the first power supply pad of the same polarity are electrically connected by a first metal wire; the lamps on the same column The second epitaxial portion of the second electrode pin pad on the bead bonding area is electrically connected to the second power supply pad of the same polarity by a second metal wire; the first metal wire and the second metal Wires are arranged at intervals; alternatively, the first extension portions of the first electrode pin pads on the M lamp bead welding areas in the same line are electrically connected to the first power supply pads of the same polarity through the first metal wire welding ; The second extension portion of the second electrode pin pad on the lamp bead welding area on the same column and the second power supply pad of the same polarity are electrically connected by a second metal wire welding, the first metal wire And spaced apart from the second metal wire.

Further, the first metal wire and the second metal wire are arranged in parallel rows and spaced apart from the lamp bead welding areas on each row; the first and second epitaxial portions on the lamp bead welding areas are respectively The first metal wire and the second metal wire outside the left and right sides thereof are electrically connected; wherein, the extension parts of the metal wires sharing the same polarity between the lamp bead welding areas on the adjacent columns are connected as a whole;

Alternatively, the first metal wire and the second metal wire are arranged at intervals in parallel with the lamp bead welding areas on each row; the first and second extension portions on the lamp bead welding areas are respectively up and down The first metal wire and the second metal wire on both sides are electrically connected; wherein, the extension parts of the metal wires sharing the same polarity between the lamp bead welding areas on the adjacent rows are connected as a whole.

Further, there are multiple metal wires that are drawn from the same power supply pad and welded to the extension part on the lamp bead welding area in the same column or row.

Further, the plurality of metal wires include long metal wires and short metal wires;

The short metal wire is used to connect the extension part on the lamp bead soldering area close to the corresponding power supply pad; the long metal line is used to connect the extension part on the lamp bead soldering area far from the corresponding power supply pad; An insulating layer is provided between the long metal wire and the extended part of the lamp bead welding area close to the power supply pad to make it electrically non-electrically connected.

Further, the signal pin pad on each lamp bead welding area includes at least a first signal input pin pad and a first signal output pin pad;

M signal pads are arranged on the printed circuit layer; the M signal pads are soldered to the first signal input pin pads and the first signal output pins in the N lamp bead soldering areas on the same column The disks are serially connected in sequence through signal lines;

Alternatively, N signal pads are arranged on the printed circuit layer; the N signal pads and the first signal input pin pads and first signal output lead pads in the M lamp bead pads on the same column The pin pads are serially connected in sequence through signal lines.

Further, the diameter of the metal wire is 0.1 mm-1 mm.

Further, the signal line is a printed signal line.

Further, the lamp bead welding area is arranged on the front surface of the transparent substrate, conductive through holes are arranged under the pin pads on the lamp bead welding area on the front surface of the transparent substrate, and the extension part is arranged on the transparent substrate On the back side of the device, electrically connecting the extension portion and the pin pad through the conductive via;

The power supply pad is also arranged on the back surface of the transparent substrate, and the extension part and the power supply pad of the same polarity are electrically connected by wire welding.

Description of the drawings

Figure 1 is a schematic cross-sectional view of a transparent LED display provided in the prior art;

2 is a schematic top view of a transparent LED display screen provided in the prior art;

3 is a partial cross-sectional schematic diagram of a transparent LED display (before encapsulation) provided in a specific embodiment of the present invention;

4 is a schematic partial cross-sectional view (after sealing) of the transparent LED display screen provided in the specific embodiment of the present invention;

5 is a schematic diagram of the bottom surface of the first LED lamp bead provided in the specific embodiment of the present invention;

6 is a schematic front view of the first LED lamp bead provided in the specific embodiment of the present invention;

7 is a schematic diagram of the bottom surface of the second type of LED lamp beads provided in the specific embodiment of the present invention;

Fig. 8 is a schematic front view of a second type of LED lamp beads provided in the specific embodiment of the present invention;

FIG. 9 is a schematic top view of a printed circuit layer and a solder wire on a transparent substrate provided in a specific embodiment of the present invention;

Fig. 10 is an enlarged schematic diagram of A in Fig. 9;

11 is a schematic partial cross-sectional view of a welding metal wire on a transparent substrate provided in a specific embodiment of the present invention;

FIG. 12 is another partial cross-sectional schematic diagram of a welding metal wire on a transparent substrate provided in a specific embodiment of the present invention;

FIG. 13 is a schematic top view of the transparent substrate provided in the embodiment of the present invention after LED lamp beads are welded;

Figure 14 is an enlarged schematic view of B in Figure 13;

15 is a schematic top view of another preferred printed circuit layer and solder wire on a transparent substrate provided in the specific embodiment of the present invention;

Fig. 16 is an enlarged schematic diagram of C in Fig. 15;

17 is a schematic top view of a further preferred printed circuit layer and solder wire on a transparent substrate provided in the specific embodiment of the present invention;

18 is a schematic partial cross-sectional view of a further preferred welding metal wire on a transparent substrate provided in the specific embodiment of the present invention;

19 is a schematic partial cross-sectional view of the printed circuit layer and the welding metal wire on the transparent substrate for welding the second type of LED lamp beads provided in the specific embodiment of the present invention;

20 is a schematic partial cross-sectional view of a preferred welding metal wire on the back of a transparent substrate provided in the specific embodiment of the present invention;

FIG. 21 is a schematic top view of another printed circuit layer and welding metal wire printed on a transparent substrate provided in the specific embodiment of the present invention.

Among them, 1. Transparent substrate; 2. LED lamp beads; 3. Printed circuit layer; 4. Metal wire; 5. Sealing layer;

20. Bracket; 21, pin; 21a, first electrode pin; 21b, second electrode pin; 21c, first signal input pin; 21d, first signal output pin; 21e, second signal input pin Pin; 21f, second signal output pin; 22, drive chip; 23, light-emitting chip; 23R, red light-emitting chip; 23G, green light-emitting chip; 23B, blue light-emitting chip;

30. Metal mesh; 31, lamp bead welding area; 32, power supply pad; 33, signal pad; 34, signal line; 31a, first electrode pin pad; 31b, second electrode pin pad; 31c, the first signal input pin pad; 31d, the first signal output pin pad; 31e, the second signal input pin pad; 31f, the second signal output pin pad; 311, the extension part; 312 , Electrical connections; 311a, the first extension part; 311b, the second extension part; 32a, the first power supply pad; 32b, the second power supply pad; 33a, the first signal pad; 33b, the second signal pad ; 34a, the first printed line; 34b, the second printed line;

41. Long metal wire; 42, short metal wire; 43, insulating layer; 44, printed grid; 4a, first metal wire; 4b, second metal wire.

detailed description

In order to make the technical problems, technical solutions, and beneficial effects solved by the present invention clearer, the following further describes the present invention in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention.

In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "upper", "lower", "front", "rear", The orientation or positional relationship indicated by "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise clearly specified and limited. For example, they can be fixed or detachable. Connected or integrally connected; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication between two components. For those of ordinary skill in the art, the specific meaning of the above-mentioned terms in the present invention can be understood in specific situations.

Example

As shown in FIG. 3 and FIG. 4, this example discloses a transparent LED display screen, which includes a transparent substrate 1 and LED lamp beads 2. The LED lamp beads 2 include a bracket 20 and a driving chip 22 formed on the bracket 20 And light-emitting chip 23.

The LED lamp beads 2 are publicly known, as shown in Figures 5, 6, 7, and 8. The LED lamp beads 2 are also provided with a number of pins 21, and the pins 21 include electrode pins. And signal pins;

For example, FIG. 5 and FIG. 6 disclose an LED lamp bead 2 with 4 pins 21 encapsulated with a driving chip 22, wherein the pins 21 include two electrode pins and two signal pins; the electrode pins It includes a first electrode pin 21a and a second electrode pin 21b; for example, the two electrode pins have opposite polarities, for example, the first electrode pin 21a is used as a positive electrode pin; the second electrode pin 21b is used as a negative electrode pin . It is used to provide power to the light-emitting chip 23 in the LED lamp bead 2; the two signal pins are called the first signal input pin 21c and the first signal output pin 21d; the driver chip 22 is provided with an interface through binding The wire is electrically connected to each light-emitting chip 23 and each pin.

In this example, the light-emitting chip 23 includes a red light-emitting chip 23R, a green light-emitting chip 23G, and a blue light-emitting chip 23B; they are arranged in a straight line; of course, they can also be arranged in a square shape.

Of course, according to different control methods, the control signal input and output signal pins can also be multiple. For example, as shown in Figures 7 and 8, the signal pins include the first signal input pin 21c and the first signal output pin. Pin 21d, second signal input pin 21e, and second signal output pin 21f. It inputs signals through two signal input pins, and outputs signals through two signal output pins.

The transparent substrate 1 can be made of various rigid or flexible materials known to the public. For example, the transparent substrate 1 can be a glass substrate, a PET (English name: Polyethylene terephthalate, Chinese name: polyethylene terephthalate) substrate, Transparent PI (English name: polyimide, Chinese name: polyimide) film, etc.

As shown in Figures 3 and 4, the transparent substrate 1 is provided with a printed circuit layer 3; the printed circuit layer 3 includes a power supply pad 32, a signal pad 33, and an array of mounting LED lamp beads 2 The lamp bead welding area 31;

Each of the lamp bead welding areas 31 is provided with a pin pad corresponding to the pin of the LED lamp bead 2; the pin pad includes a signal pin pad and an electrode pin pad; An extension part 311 is drawn on the electrode lead pad;

A signal line for signal transmission is provided between the signal pad 33 and the signal pin pads in the lamp bead welding area 31, and between the signal pin pads in the adjacent lamp bead welding areas 31 in the same row or the same column. 34; so that the control signal that controls the on and off of each LED lamp bead 2 can be input from the signal pad 33 and then transmitted through each LED lamp bead 2 in turn;

The power supply pad 32 in this example is used to connect to an externally connected DC power supply, and the DC power supply is connected to each LED lamp bead 2 through the power supply pad 32 through the metal wire 4 mentioned in this application; It includes a first power supply pad 32a and a second power supply pad 32b with opposite polarities; for example, in this example, the first power supply pad 32a is a positive electrode pad; the second power supply pad 32b is a negative electrode pad;

The power supply pads 32 can only be provided with two opposite polarities, such as a first power supply pad 32a and a second power supply pad 32b; the lamp beads on the power supply pads 32 can be arranged in an array by a metal wire 4 The pin pads of the same polarity on the pad 31 are electrically connected. Or the power supply pads 32 can also be provided in multiple, and the pin pads of the same polarity on the lamp bead pads 31 on a row or column can be electrically connected to one power supply pad 32 through the metal wire 4. Some examples will be given below.

Similarly, the signal pad 33 is used to connect to an external signal input source, and it is usually connected to the upper-level control chip; the number of the signal pad 33 is not specifically limited, for example, as mentioned in the background art In FIG. 2, there is only one signal pad 33, which inputs a control signal through one signal pad 33, and then transmits the control signal to each LED lamp bead 2 connected in series via the signal line 34 in turn. Of course, it can also be set according to the number of I/O ports on the control chip. For example, the LED lamp beads 2 in the same row or the same column use the same signal pad 33, or the LED lamp beads 2 in multiple rows or columns use the same signal pad 33, which is allowed.

Regarding the signal line 34 defined here, it can be a printed signal line printed on the transparent substrate 1. The printed signal line can be an ITO (full Chinese name: indium tin oxide; full English name: Indium Tin Oxides) line or Silver paste wire or copper clad wire, etc., in this example, a grid-like copper clad wire printed on the transparent substrate 1 is used. Or use a point-to-point metal wire machine to mark up the flying line connection to form a flying line network. Similarly, the pads on the printed circuit layer 3 and the epitaxial portion 311 can also be made of a transparent conductive material as a printed circuit, such as metal mesh, ITO, nano silver and so on.

In particular, the signal line 34 and the extension part 311 can achieve a line width as small as 0.1mm by using copper-clad materials in actual production, and the conductivity is sufficient for the power supply requirements and signal transmission of a single LED lamp, which blocks the line of sight Very small, can achieve extremely high transparency of the entire LED display.

The extension part 311 of the electrode pin pad on the lamp bead welding area 31 and the power supply pad 32 of the same polarity are electrically connected by welding through a metal wire 4.

As shown in FIG. 4, after the LED lamp bead 2 is soldered to the corresponding lamp bead welding area 31 on the transparent substrate 1 by surface mount technology, a layer of sealing glue 5 is packaged on the surface of the transparent substrate 1 as a whole. Further, according to needs, a transparent protective cover can also be provided on the sealant layer 5. The wiring harness is drawn from the power supply pad 32 and the signal pad 33, and the edge between the transparent protective cover and the transparent substrate 1 is sealed and packaged to make it waterproof.

The following will further explain and explain in combination with specific preferred embodiments.

As shown in Figure 9, the printed circuit layer 3 is provided with N rows*M columns of lamp bead welding areas 31; as an example, suppose N=5; M=5; in this example, a transparent substrate 1 is printed 5*5 lamp beads welding area 31. In order to enable those skilled in the art to understand the concept of the present invention, the column composed of the lamp bead pads 31 on the same row is called a welding row; the column composed of the lamp bead pads 31 on the same column is called a welding row.

As shown in Figures 9 and 10, five signal pads 33 are arranged on the printed circuit layer 3; the five signal pads 33 are soldered with the signal pins in the five lamp bead pads 31 on the same column. The disks are connected in series through the signal line 34; specifically, the first signal input pin pad 31c and the first signal output pin pad 31d are provided in the lamp bead welding area 31; the serial connection described corresponds to The signal pads 33 on the column are connected to the first lamp bead pads 31 in the column through a signal line 34 (for the sake of distinction, the signal line 34 is called the first printed line 34a in this example). A signal input pin pad 31c; then through the first signal output pin pad 31d in the first lamp bead welding area 31 through the signal line 34 (in this example, the signal in the adjacent lamp bead welding area 31 The line 34 is called the second printed line 34b) is connected to the first signal input pin pad 31c in the second lamp bead welding area 31 on the same column, in this way, the third, fourth, and fifth lamp bead welding areas 31 is connected in series. Of course, the way of concatenation is not necessarily limited to the same line or the same column. The signal lines 34 in this example all adopt a grid-like form, which can further increase the transparency of the transparent LED display.

In this example, five pairs of power supply pads 32 are arranged on the printed circuit layer 3; each pair of power supply pads 32 includes a first power supply pad 32a and a second power supply pad 32b with opposite polarities;

As shown in FIGS. 9-10, the electrode pin pads in each of the lamp bead welding areas 31 include a first electrode pin pad 31a and a second electrode pin pad 31b; A first extension portion 311a is drawn on the electrode pin pad 31a; a second extension portion 311b is drawn on the second electrode pin pad 31b;

The first extension part 311a of the first electrode pin pad 31a on the five lamp bead pads 31 in the same column and the first power supply pad 32a of the same polarity are electrically connected by welding through a first metal wire 4a; The second extension portion 311b of the second electrode lead pad 31b on the lamp bead pad 31b in the same column and the second power supply pad 32b of the same polarity are electrically connected by welding through a second metal wire 4b.

The welding described in this example refers to spot welding connection. As shown in Figure 11 and Figure 12, when the spot welding connection is made, especially in the production of high-density products of the present invention, as shown in Figure 11, a binding wire bonding machine can be used to tie the solder joints to the solder joints. The fixed wire method connects the metal wire 4 between the solder joints, so it will form a certain curved arc. When making the low-density product of the present invention, it can also be pressed in a straight line like the one in Figure 12 Combine it on each solder joint and perform furnace soldering by brushing solder paste.

After the LED lamp bead 2 is mounted on the transparent substrate 1 provided with the printed circuit layer 3, the result is shown in FIG. 13 and FIG. 14, which passes through the power pad 32 through the metal wire 4 and the lamp bead pad 31 on the The extension portion 311 extending from the electrode pin pad is electrically connected, and the current is electrically connected from the electrode pin of the LED lamp bead 2 through the electrode pin pad to form a power supply circuit. At the same time, the control signal flowing in from the signal pad 33 sequentially flows through each LED lamp bead 2 connected in series, and is received by the previous LED lamp bead 2 and transmitted to the next LED lamp bead 2. The on-off and color change control of the light-emitting chip 23 on each LED lamp bead 2 has been achieved.

Regarding the metal wire 4, the material or the like is not particularly limited, as long as its conductivity meets the requirements, and a metal with high conductivity is generally preferred. In this example, copper wire is preferably used. Preferably, the diameter of the metal wire 4 is 0.1 mm-1 mm. It is ideal for the diameter of the metal wire 4 to be in the range of 0.1mm-1mm. Within this diameter range, the power supply requirements of the entire array of LED lamp beads 2 can be ideally met, and the conductivity of other transparent conductive materials is many times stronger. At the same time, the smaller-diameter metal wire 4 has a relatively small barrier to the line of sight, which can ensure extremely high permeability.

The transparent LED display provided in this example adopts a method that can combine a metal wire 4 with a higher current and a pad set on the transparent substrate 1 to replace the metal grid printed on the transparent substrate 1 for each LED The lamp bead 2 is powered, for example: a copper wire with a diameter of 0.5mm, its conductivity is equivalent to a copper foil with a width of 5.6mm and a thickness of 35μm without mesh. If a metal grid of the same cross-sectional area is made, the width will be larger. The light-blocking part of the copper wire is only 0.5mm wide. Compared with the metal grid made of copper foil, the transparency is greatly improved, so that it can further reduce the distance between the LED lamp beads 2 and improve its resolution. At the same time, the smaller diameter metal wire 4 is also less obstructive to the line of sight. For the 0.5mm diameter copper wire, the human eye is already difficult to detect beyond 1.5m. For the LED display screen, it is generally 2- The viewing distance of 3m, therefore, this solution just satisfies the need to ensure the transparency and conductivity of the screen, and can make the transparency of the transparent LED display better.

If the size of the LED lamp bead 2 with the built-in driver chip 22 is 1.2mm*1.2mm, the spacing of the LED lamp bead 2 is 5mm*5mm, and the diameter of the wire is 0.3mm, a permeability of more than 90% can be achieved. A transparent LED display with high transparency and high resolution.

As another preferred manner, as shown in FIG. 15 and FIG. 16, it may also be arranged with M+1 power supply pads 32 or N+1 power supply pads 32 on the printed circuit layer 3;

In this example, N=M=5 is still used as an example for description. Six power supply pads 32 are arranged on the printed circuit layer 3.

The six power supply pads 32 include first power supply pads 32a and second power supply pads 32b with opposite polarities arranged at intervals; as shown in FIG. 15, the six power supply pads 32 are arranged in a row of lamp bead welding areas On the upper side of 31, there are first power supply pad 32a, second power supply pad 32b, first power supply pad 32a, second power supply pad 32b, first power supply pad 32a, and second power supply pad 32b;

Similarly, the electrode pin pads include a first electrode pin pad 31a and a second electrode pin pad 31b; the first electrode pin pad 31a has a first extension portion 311a led out; A second extension portion 311b is led out on the second electrode lead pad 31b;

Then the first extension portion 311a of the first electrode pin pad 31a on the five lamp bead pads 31 in the same column and the first power supply pad 32a of the same polarity are electrically connected by welding through the first metal wire 4a ; That is, the first epitaxial portion 311a on the same column is electrically connected to the first power supply pad 32a through the first metal wire 4a; the second electrode pin pad 31b on the lamp bead pad 31 on the same column The second epitaxial portion 311b and the second power supply pad 32b of the same polarity are electrically connected by welding through the second metal wire 4b; that is, the second epitaxial portion 311b on the same welding column is welded to the second power source through the second metal wire 4b The disk 32b is electrically connected; the first metal wire 4a and the second metal wire 4b are spaced apart; the first metal wire 4a and the second metal wire 4b are flat with the lamp bead pads 31 on each column The first and second extension portions 311a and 311b on each of the lamp bead welding areas 31 are respectively electrically connected to the first metal wire 4a and the second metal wire 4b outside the left and right sides; in this example, As a preferred manner, as shown in FIG. 16, the extension portions 311 of the metal wires 4 sharing the same polarity between the lamp bead pads 31 on adjacent columns are connected as a whole. For example, a first power supply pad 32a is provided on the upper part between the two adjacent welding rows, and three first metal wires 4a are soldered from the first power supply pad 32a; between two adjacent rows and columns The first extension portion 311a on the lamp bead welding area 31 is extended as a whole. As a preferred way, in order to prevent the first extension portion 311a from interfering with other signal lines 34, etc., as shown in the lamp bead pad 31 on the left in FIG. 16, the first extension portion 311a can be made from four The inside of the lead pad passes through.

Of course, the power supply pads 32 and the signal pads 33 can also be arranged in a row, and the first epitaxial portion 311a of the first electrode pin pad 31a on the M lamp bead pads 31 in the same row and the same polarity The first power supply pad 32a is electrically connected by welding through the first metal wire 4a; connects the second extension portion 311b of the second electrode pin pad 31b on the lamp bead pad 31 in the same column with the second extension portion 311b of the same polarity. The power supply pad 32b is electrically connected by welding through a second metal wire 4b, and the first metal wire 4a and the second metal wire 4b are spaced apart.

In this example, as a preferred way, there are multiple metal wires 4 that are soldered and connected to the extension portion 311 on the lamp bead pad 31 in the same column or row from the same power supply pad 32. For example, in this example, among the power supply pads 32 arranged from left to right, there are 3 metal wires 4 arranged on 2-5 power supply pads 32. The three metal wires 4 are spot-welded and connected to the same-polarity extension part 311 on the adjacent welding row. Dividing the metal wire 4 into a plurality of weldings can further reduce the diameter of the metal wire 4, making the metal wire 4 more difficult to be observed. The transparency of the transparent LED display is enhanced.

Further, as a preferred manner, as shown in FIG. 17, the plurality of metal wires 4 include a long metal wire 41 and a short metal wire 42;

The short metal line 42 is used to connect the extension part 311 on the lamp bead pad 31 close to the corresponding power supply pad 32; the long metal line 41 is used to connect the extension part on the lamp bead pad 31 farther from the corresponding power supply pad 32 311;

As shown in FIG. 18, an insulating layer 43 is provided between the long metal wire 41 and the extended portion 311 of the lamp bead pad 31 close to the power supply pad 32 to make it non-electrically connected. The purpose of this is to ensure that power is supplied to the LED lamp bead 2 close to the power supply pad 32, and it is no longer necessary to continue to extend the wire to the LED lamp bead 2 far away from the power supply pad 32, thus in the area far away from the power supply pad 32 Reduce the number of metal wires 4 and improve the transparency of the LED screen. By adopting the long metal wire 41 and the short metal wire 42, the LED lamp beads 2 with different distances can get just enough current to ensure that the LED lamp far away from the power supply pad 32 can get enough voltage while reducing The metal line blocks the line of sight and improves the transparency.

Of course, the above embodiments mainly take the LED lamp bead 2 as an example with 4 pins. As shown in FIG. 19, the pads of the lamp bead welding area 31 can be designed to increase correspondingly, and each lamp bead can be soldered. The signal line 34 between the signal pin pad and the signal pad 33 in the area 31 is sufficient. For example, the lamp bead welding area 31 includes a first signal input pin pad 31c, a first signal output pin pad 31d, a second signal input pin pad 31e, and a second signal output pin pad 31f. . Correspondingly, the signal pad 33 includes a first signal pad 33a and a second signal pad 33b; the first signal pad 33a is connected to the first signal input pin of the first lamp bead pad 31 through the signal line 34 Disk 31c, the second signal pad 33b is connected to the second signal input pin pad 31e of the first lamp bead pad 31 through the signal line 34; the first signal output pin of the first lamp bead pad 31 is welded The disk 31d is connected to the first signal input pin pad 31c of the second lamp bead pad 31 through a signal line 34, and the second signal output pin pad 31f of the first lamp bead pad 31 is connected through a signal line 34 The second signal input pin pad 31e to the second lamp bead welding area 31, and so on.

As a preferred way, as shown in FIG. 20, if the surface on which the LED lamp bead 2 is installed is defined as the front surface of the transparent substrate 1, the surface opposite to the front surface on which the LED lamp bead 2 is not installed is the back surface; The lamp bead soldering area 31 is arranged on the front surface of the transparent substrate 1, a conductive via 312 is provided under the pin pads on the lamp bead soldering area 31 on the front surface of the transparent substrate 1, and the extension portion 311 is arranged on the The back surface of the transparent substrate 1 is electrically connected to the extension portion 311 and the pin pads through the conductive through holes 312; such conductive through holes can be easily realized by the copper sinking process of the printed circuit board.

The power supply pad 32 is also arranged on the back surface of the transparent substrate 1, and the extension portion 311 is electrically connected to the power supply pad 32 of the same polarity through a metal wire 4. The beneficial effect of this solution is that the metal wire 4 can be installed directly under the LED lamp bead 2, especially for the production of high-density transparent LED display screens, so that part of the metal wire 4 and the LED lamp bead 2 can overlap, which can further To increase transparency.

Of course, in this example, it is not limited to only use the metal wire 4 to connect the power supply pad 32 and the extension portion 311. As shown in FIG. 21, the metal wire 4 can also be used as the main current transmission method, and then the metal mesh Grid (for the sake of distinction, the metal grid is named and marked as printed grid 44 in this example) to connect the extension part 311; the mesh density requirement of the printed grid 44 can be reduced, and its effect is equivalent to that of the original grid. In the invented extension part 311, the width of the printed grid 44 can be relatively narrow, so as to reduce the gap between the LED lamp beads 2 and improve its resolution.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention shall be included in the protection of the present invention. Within range.

Claims

A transparent LED display screen, comprising a transparent substrate and LED lamp beads; characterized in that, the LED lamp beads include a bracket, a driving chip and a light-emitting chip formed on the bracket; and a number of pins are also provided on the LED lamp beads , The pins include electrode pins and signal pins;

A printed circuit layer is arranged on the transparent substrate; the printed circuit layer includes power supply pads, signal pads and lamp bead welding areas arranged in an array for mounting LED lamp beads;

Each of the lamp bead welding areas is provided with a pin pad corresponding to the pin of the LED lamp bead; the pin pad includes a signal pin pad and an electrode pin pad; each of the electrodes There is an extension part on the lead pad;

A signal line for signal transmission is provided between the signal pad and the signal pin pad in the lamp bead welding area, and between the signal pin pads in the adjacent lamp bead welding area in the same row or the same column; The control signal for each LED lamp bead to turn on and off can be transmitted sequentially through each LED lamp bead after being input from the signal pad;

The extension part of the electrode pin pad on the lamp bead welding area is electrically connected with the power supply pad of the same polarity through metal wire welding.
The transparent LED display according to claim 1, wherein the printed circuit layer is provided with N rows * M columns of lamp bead welding areas;

M signal pads are arranged on the printed circuit layer; the M signal pads and the signal pin pads in the N lamp bead pads in the same column are serially connected in sequence through signal lines;

Alternatively, N signal pads are arranged on the printed circuit layer; the N signal pads and the signal pin pads in the M lamp bead welding areas on the same line are sequentially connected in series through signal lines.
The transparent LED display screen according to claim 2, wherein M pairs of power supply pads or N pairs of power supply pads are arranged on the printed circuit layer; each pair of the power supply pads includes a first A power supply pad and a second power supply pad;

The electrode pin pad includes a first electrode pin pad and a second electrode pin pad; a first epitaxial portion is drawn on the first electrode pin pad; the second electrode pin pad There is a second extension part on the top lead;

The first extension part of the first electrode pin pads on the N lamp bead pads on the same column and the first power supply pad of the same polarity are electrically connected by a first metal wire; the lamps on the same column The second extension part of the second electrode pin pad on the bead welding area is electrically connected to the second power supply pad of the same polarity through the second metal wire welding; or, the M lamp bead welding areas on the same line The first extension part of the first electrode lead pad on the upper side is electrically connected to the first power supply pad of the same polarity through the first metal wire welding; the second electrode on the lamp bead welding area on the same column The second extension part of the pin pad is electrically connected to the second power supply pad of the same polarity through a second metal wire welding.
The transparent LED display screen of claim 2, wherein M+1 power supply pads or N+1 power supply pads are arranged on the printed circuit layer;

The M+1 power supply pads or N+1 power supply pads include first power supply pads and second power supply pads with opposite polarities arranged at intervals;

The electrode pin pad includes a first electrode pin pad and a second electrode pin pad; a first epitaxial portion is drawn on the first electrode pin pad; the second electrode pin pad There is a second extension part on the top lead;

The first extension part of the first electrode pin pads on the N lamp bead pads on the same column and the first power supply pad of the same polarity are electrically connected by a first metal wire; the lamps on the same column The second epitaxial portion of the second electrode pin pad on the bead bonding area is electrically connected to the second power supply pad of the same polarity by a second metal wire; the first metal wire and the second metal Wires are arranged at intervals; alternatively, the first extension portions of the first electrode pin pads on the M lamp bead welding areas in the same line are electrically connected to the first power supply pads of the same polarity through the first metal wire welding ; The second extension portion of the second electrode pin pad on the lamp bead welding area on the same column and the second power supply pad of the same polarity are electrically connected by a second metal wire welding, the first metal wire And spaced apart from the second metal wire.
The transparent LED display screen according to claim 4, wherein the first metal wire and the second metal wire are arranged in parallel with the lamp bead welding area on each row at intervals; The first extension part and the second extension part on the area are respectively electrically connected to the first metal wire and the second metal wire outside the left and right sides; wherein, the lamp bead welding areas on adjacent columns share the same polarity metal The extension part of the line is connected as a whole;

Alternatively, the first metal wire and the second metal wire are arranged at intervals in parallel with the lamp bead welding areas on each row; the first and second extension portions on the lamp bead welding areas are respectively up and down The first metal wire and the second metal wire on both sides are electrically connected; wherein, the extension parts of the metal wires sharing the same polarity between the lamp bead welding areas on the adjacent rows are connected as a whole.
The transparent LED display according to any one of claims 3, 4, 5, characterized in that, from the same power supply pad, the extension part of the lamp bead welding area on the same column or row is soldered and connected. There are multiple metal wires.
The transparent LED display screen of claim 6, wherein the plurality of metal wires comprise long metal wires and short metal wires;

The short metal wire is connected to the extension part on the lamp bead welding area close to the corresponding power supply pad; the long metal line is connected to the extension part on the lamp bead welding area farther from the corresponding power supply pad; the long metal line An insulating layer is provided between the extension parts of the lamp bead welding area close to the power supply pad to make it non-electrically connected.
The transparent LED display screen according to claim 2, wherein the signal pin pad on each lamp bead welding area includes at least a first signal input pin pad and a first signal output pin pad;

M signal pads are arranged on the printed circuit layer; the M signal pads are soldered with the first signal input pin pads and the first signal output pin in the N lamp bead soldering areas on the same column The disks are serially connected in sequence through signal lines;

Alternatively, N signal pads are arranged on the printed circuit layer; the N signal pads and the first signal input pin pads and first signal output lead pads in the M lamp bead pads on the same column The pin pads are serially connected in sequence through signal lines.
The transparent LED display screen according to claim 1, wherein the diameter of the metal wire is 0.1mm-1mm.
The transparent LED display screen of claim 1, wherein the signal line is a printed signal line.
The transparent LED display according to claim 1, wherein the lamp bead welding area is arranged on the front surface of the transparent substrate, and a conductive connection is arranged under the pin pads on the lamp bead welding area on the front surface of the transparent substrate. Hole, disposing the extension part on the back surface of the transparent substrate, and electrically connecting the extension part and the pin pad through the conductive via;

The power supply pad is also arranged on the back surface of the transparent substrate, and the extension part and the power supply pad of the same polarity are electrically connected by wire welding.