CN111526669B

CN111526669B - Transparent circuit board and manufacturing method of transparent LED display screen

Info

Publication number: CN111526669B
Application number: CN202010378101.8A
Authority: CN
Inventors: 李淑玲
Original assignee: Shenzhen Jinghong Technology Co ltd
Current assignee: Shenzhen Jinghong Technology Co ltd
Priority date: 2020-05-07
Filing date: 2020-05-07
Publication date: 2021-07-23
Anticipated expiration: 2040-05-07
Also published as: CN111526669A

Abstract

In order to solve the problems that the scheme of the manufacturing method of the transparent circuit board in the prior art is relatively complex, the reliability is poor, the adhesion degree of a circuit pattern formed by copper foil and a transparent substrate is poor, and the circuit pattern is easy to fall off from the transparent substrate, the invention provides a manufacturing method of the transparent circuit board and a transparent LED display screen. The invention provides a manufacturing method of a transparent circuit board on one hand, which comprises the following steps: manufacturing a binder circuit on a transparent substrate; copper powder is uniformly scattered on the transparent substrate comprising the binder circuit, and then the copper powder is pressed and infiltrated into the binder circuit; removing redundant copper powder on the transparent substrate to form a copper-clad circuit; and filling gaps among copper powder particles in the copper-coated circuit to form a circuit pattern. The manufacturing method of the transparent circuit board provided by the invention can meet the use requirement of the transparent LED display screen. The circuit pattern formed by the method has firm bonding between the copper and the transparent substrate, and does not deform or fall off.

Description

Transparent circuit board and manufacturing method of transparent LED display screen

Technical Field

The invention relates to the technical field of a printed circuit board of a transparent substrate as an LED transparent display screen.

Background

The printed circuit of the transparent substrate is generally applied to the field of LCD display screens, a metal conducting layer, usually a copper plating layer, is formed on the transparent substrate such as glass in a magnetron sputtering mode, then a circuit pattern is formed on the transparent substrate in an etching mode, the thickness of the conducting layer is generally in a nanometer level, and the conducting current is very small. In addition, there is a proposal of forming a transparent circuit pattern on a glass substrate by using a conductive material such as ITO, nano silver, metal mesh, etc., but the square resistance of the circuit pattern is large, and the conductive current is also small, which is difficult to use in products with large current demand.

For example, a transparent LED circuit board using transparent glass as a substrate is taken as an example, the LED lamps mounted on the glass substrate have a large demand for current, one LED lamp needs about 3-15 mA (milliampere) of driving current, and a square meter of LED display screen is mounted with 1000-20000 unequal LED lamps, which has a very large demand for current.

As an improvement, a new glass substrate copper-clad process is proposed, and a copper-clad layer with the thickness of 10-35 microns is formed on the glass substrate, so as to meet the application requirements of the transparent LED circuit board. The new process substantially comprises the following steps: laminating a copper foil on the release film; printing an anti-etching hot-pressing adhesive on the copper foil covered and pressed on the release film according to the circuit pattern, wherein the anti-etching hot-pressing adhesive forms an etching protective layer on the copper foil; etching the copper foil printed with the etching-resistant hot-pressing glue by using an etching solution, and etching and removing the part except the etching protective layer to obtain the copper foil circuit pattern; cleaning the glass substrate; bonding the copper foil circuit pattern with the glass substrate, and carrying out hot pressing on the glass substrate and the copper foil circuit pattern to pre-bond the copper foil circuit pattern with the glass substrate; and tearing off the release film, baking the glass substrate and the copper foil circuit pattern to tightly bond and reinforce the copper foil circuit pattern and the glass substrate into a whole, thereby obtaining the copper-clad glass substrate.

In the method, after a circuit pattern is formed on the copper foil of the composite release film in a developing and etching mode, the copper foil circuit pattern is pre-bonded in a hot pressing mode and then baked, and the copper foil circuit pattern and the glass substrate are tightly bonded into a whole. The applicant finds that in the analysis process, the copper foil is required to be attached to the release film, and the displacement is easy to cause errors during transfer, so that the reliability of the product is poor; the scheme is still relatively complicated, and in addition, the circuit pattern formed by the copper foil has poor adhesion with the glass substrate and is easily detached from the glass substrate.

Disclosure of Invention

The invention provides a transparent circuit board and a manufacturing method of a transparent LED display screen, and aims to solve the problems that a circuit pattern formed by copper foil is poor in adhesion degree with a transparent substrate and is easy to fall off from the transparent substrate when a transparent LED circuit board is manufactured in the prior art.

A manufacturing method of a transparent circuit board comprises the following steps:

manufacturing a binder circuit on a transparent substrate;

uniformly spreading copper powder on the transparent substrate comprising the binder circuit, and pressing and infiltrating the copper powder into the binder circuit;

removing redundant copper powder on the transparent substrate to form a copper-clad circuit;

and filling gaps among copper powder particles in the copper-coated circuit to form a circuit pattern.

Optionally, the "fabricating an adhesive line on a transparent substrate" includes:

manufacturing a silk-screen printing plate according to a preset circuit pattern;

and printing the adhesive on the front surface of the transparent substrate through the silk-screen printing plate to form an adhesive circuit.

Optionally, the width of the adhesive line is greater than or equal to 0.1 millimeters.

Optionally, the adhesive is UV glue; the step of uniformly spreading copper powder on the transparent substrate including the binder circuit and then pressing and infiltrating the copper powder into the binder comprises the following steps:

uniformly throwing copper powder on the front surface of the transparent substrate to cover the binder circuit on the transparent substrate;

irradiating UV glue from the back of the transparent substrate by using ultraviolet rays, and curing the UV glue and the copper powder particles covered on the UV glue together;

and applying pressure on the solidified copper powder to enable particles of the copper powder to penetrate into the solidified UV glue.

Optionally, the particle diameter of the copper powder is 500-1000 nm.

Optionally, the "filling gaps between particles of copper powder on the copper-clad wire to form a circuit pattern" includes:

carrying out copper deposition process treatment on the transparent substrate including the copper-coated circuit to enable copper ions to be deposited in gaps among copper powder particles;

and removing redundant copper ions falling on the transparent substrate after the copper deposition process treatment, and then drying the transparent substrate in a dust-free state.

throwing tin powder on the front surface of the transparent substrate to cover the copper-coated circuit on the transparent substrate;

applying pressure on the tin powder to enable particles of the tin powder to be embedded into gaps among particles of the copper powder on the copper-coated circuit;

and removing the redundant tin powder on the transparent substrate, and then heating the transparent substrate to a preset temperature to melt and flow the tin powder and fill gaps among copper powder particles.

Optionally, the tin powder has a particle diameter of 30-50 nanometers.

Optionally, the preset temperature is 260 ℃.

Optionally, the transparent substrate is a high temperature resistant transparent glass substrate.

Optionally, the circuit pattern includes a power supply pad, a signal pad, and a lamp bead welding area for mounting LED lamp beads arranged in an array;

each lamp bead welding area is provided with a pin welding disc corresponding to a pin of the LED lamp; the pin bonding pads comprise signal pin bonding pads and electrode pin bonding pads;

signal wires for signal transmission are arranged between the signal bonding pads and the signal pin bonding pads in the lamp bead welding areas and between the signal pin bonding pads in the adjacent lamp bead welding areas in the same row or the same column; control signals for controlling the on and off of the LED lamp beads can be input from the signal bonding pad and then transmitted in sequence through the LED lamp beads;

and electrically connecting the electrode pin pad on the lamp bead welding area with the power supply pad with the same polarity through a power line.

A manufacturing method of a transparent LED display screen comprises the following steps: manufacturing a transparent circuit board, mounting an LED lamp on the transparent circuit board, and then packaging, wherein the method for manufacturing the transparent circuit board is the method for manufacturing the transparent circuit board according to any one of claims 1 to 11.

According to the manufacturing method of the transparent circuit board, when the transparent circuit board is manufactured, the circuit pattern with copper as the conductive material can be directly formed on the transparent substrate, the conductive requirement of a high-power electronic component can be met, and meanwhile, the high transparency of a finished product can be guaranteed, so that the use requirement of the transparent LED display screen can be met. The circuit pattern formed by the method not only enables the copper powder and the transparent substrate to be firmly bonded, but also greatly enhances the electric conductivity by filling gaps among particles of the copper powder; the adhesive force between the circuit pattern and the transparent substrate is still very stable after high-temperature reflow soldering, and the circuit pattern is not deformed and does not fall off.

Drawings

FIG. 1 is a flow chart of a process for fabricating a transparent circuit board according to an embodiment of the present invention;

FIG. 2 is a flowchart of the optimization of step S1 in FIG. 1;

FIG. 3 is a schematic diagram of the formation of adhesive lines on a transparent substrate provided in an embodiment of the present invention;

FIG. 4 is a flowchart of the optimization of step S2 in FIG. 1;

FIG. 5 is a schematic diagram of copper-clad circuit formation on a transparent substrate according to an embodiment of the present invention;

FIG. 6 is a flowchart of an optimization of step S4 in FIG. 1;

FIG. 7 is a schematic illustration of a copper deposition process for filling line gaps in accordance with an embodiment of the present invention;

FIG. 8 is another flowchart for optimizing step S4 in FIG. 1;

FIG. 9 is a schematic diagram of a process for filling line gaps by a tin powder melting process provided in an embodiment of the present invention;

FIG. 10 is a schematic top view of a transparent circuit board provided in an embodiment of the present invention;

FIG. 11 is an enlarged view taken at A in FIG. 10;

FIG. 12 is a schematic view of a microscope photograph of the copper particle-filled substrate provided in this example;

fig. 13 is a schematic view of the microscope photograph of the solder powder melted and filled in the embodiment.

Wherein, 1, a transparent substrate; 2. a binder; 3. copper powder; 4. screen printing of a screen plate; 5. a squeegee; 6. an ultraviolet light irradiation device; 7. a roller; 8. a flushing device; 9. copper ions; 10. tin powder;

20. a binder circuit; 30. covering a copper circuit; 40. a circuit pattern;

100. gluing a substrate; 200. a copper-clad substrate; 300. a transparent circuit board;

40a, a pin pad; 40b, a power supply pad; 40c, signal pads; 40d, a power line; 40e, a first signal line; 40f, a second signal line.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it is to be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1

The present embodiment will specifically explain the manufacturing method of the transparent circuit board provided by the present invention, as shown in fig. 1, including the following steps:

step S1, adhesive line forming step: manufacturing an adhesive line 20 on a transparent substrate 1;

step S2, copper powder pressing and bonding step: uniformly throwing copper powder 3 on the transparent substrate 1 comprising the binder circuit 20, and pressing and infiltrating the copper powder 3 into the binder circuit 20; the particle diameter of the copper powder 3 is 500-1000 nm.

Step S3, copper-clad wire forming step: removing the redundant copper powder 3 on the transparent substrate 1 to form a copper-clad circuit 30;

step S4, line gap filling step: gaps between copper powder particles in the copper-clad wiring 30 are filled to form a circuit pattern 40.

The steps are explained in detail below.

In step S1, the transparent substrate 1 is a high temperature-resistant transparent glass substrate, preferably tempered glass, and in some embodiments may also be an acrylic or PET film, or made into a flexible substrate. In this embodiment, the circuit pattern is printed on the transparent substrate 1 by a screen printing method, so that the circuit pattern defined by the adhesive 2 is formed on the transparent substrate 1. The transparent substrate 1 to which the adhesive 2 is bonded is referred to as a coated substrate 100. As shown in fig. 2, the step S1 of forming the adhesive line 20 on the transparent substrate 1 includes:

in step S11, the screen printing plate manufacturing step: and manufacturing the silk-screen printing plate 4 according to a preset circuit pattern.

Here, the manufacturing method of the screen printing plate 4 includes the operation steps of selecting a screen, coating, drying and developing, which are prior art and will not be described here. In this embodiment, the image-text portion of the screen printing plate 4 is a preset circuit pattern, that is, a circuit pattern of a circuit pattern.

In step S12, an adhesive line forming step: and printing an adhesive 2 on the front surface of the transparent substrate 1 through the silk-screen printing plate 4 to form an adhesive line 20.

In the embodiment, the basic principle that the meshes of the image-text part of the silk-screen plate 4 can penetrate through the binder 2 and the meshes of the non-image-text part cannot penetrate through the binder 2 is used for printing the circuit. Illustratively, when printing, the adhesive 2 is poured into the screen printing plate 4, the squeegee 5 is used to press the adhesive 2 on the screen printing plate 4, so that the adhesive 2 is pressed by the squeegee from the mesh of the image-text portion onto the printing material, i.e., the transparent substrate 1, thereby printing the adhesive line 20 on the transparent substrate 1. The adhesive lines 20 have a width greater than or equal to 0.1 mm. The transparent substrate 1 including the adhesive line 20 is referred to herein as a gummed substrate 100, as shown in fig. 3.

In step S2, it is necessary to bond copper powder 3 and transparent substrate 1 by using bonding agent 2, and there are many choices of bonding agent 2, such as thermoplastic glue, thermosetting glue, UV glue, etc., as long as it can achieve bonding of copper powder 3 and transparent substrate 1 under specific conditions; the thermosetting adhesive is an adhesive which forms a chemical bond under the independent action or combined action of heat and a catalyst, and is not melted or dissolved after being cured; the thermoplastic resin is a synthetic resin adhesive made of thermoplastic resin. The adhesive is softened and bonded when heated, and is hardened after cooling to have a certain strength. UV glue is also known as shadowless glue, photosensitive glue, UV-curable glue, etc., and is a kind of adhesive that can be cured only by irradiation of UV light. It can be used as adhesive, or as sizing material for paint, coating and ink. UV is an abbreviation for Ultraviolet Rays, the term UV light. The curing principle of the shadowless adhesive is that a photoinitiator (or photosensitizer) in a UV curing material generates active self-radical or cation after absorbing ultraviolet light under the irradiation of ultraviolet light, and the polymerization and crosslinking chemical reaction of monomers are initiated, so that a binder is converted from a liquid state to a solid state within a few seconds. In this example, the UV paste is used as an example to describe how the copper powder 3 is bonded to the transparent substrate 1.

As shown in fig. 4, the method specifically includes the following steps:

in step S21, the front-side copper powder spraying step: as shown in fig. 5, the adhesive 2 is a UV paste, and copper powder 3 is uniformly sprayed on the front surface of the transparent substrate 1 to cover the adhesive lines 20 on the transparent substrate 1.

In the present embodiment, "front surface" and "back surface" are relative concepts, and the adhesive lines 20 of UV paste are printed on the front surface of the transparent substrate 1, and then the copper powder 3 is uniformly scattered, so that the copper powder 3 covers the transparent substrate 1, particularly the adhesive lines 20; when ultraviolet light is irradiated, irradiation must be performed from the back surface of the transparent substrate 1.

In step S22, an ultraviolet curing step: UV glue is irradiated from the back surface of the transparent substrate 1 by using ultraviolet rays, and the UV glue and the copper powder particles covered on the UV glue are cured together.

In step S23, a copper powder press bonding step: and applying pressure on the solidified copper powder 3 to enable particles of the copper powder to penetrate into the solidified UV glue.

The transparent substrate 1 and the copper powder 3 are bonded by using UV glue, and the manufacturing process can be carried out at normal temperature. The process can be effectively simplified when the process is carried out at normal temperature, the requirement on the processing environment is not high, the energy consumption is reduced, and the cost is reduced.

As a preferred example of the present invention, as shown in fig. 5, the step S22 is implemented by irradiating UV glue from the back surface of the transparent substrate 1 by emitting ultraviolet rays from the ultraviolet irradiation device 6 until the UV glue is cured, and curing and bonding the copper powder particles coated on the adhesive 2 and the transparent substrate 1. Optionally, the irradiation time is within 10 seconds. After the curing, the copper powder particles are further infiltrated into the cured binder 2 by a light weight pressing method, and the step S23 is implemented by pressing a roller 7 from one end to the other end above the copper powder 3 (in the figure, the roller 7 rolls from the right side of the paper surface to the left side of the paper surface), and pressing the copper powder 3 into the binder 2 of the transparent substrate 1, that is, rolling the copper powder particles by the roller 7 so that the copper powder particles are further infiltrated into the binder 2, thereby obtaining the intermediate body marked in the figure and containing the copper powder 3, the UV glue and the transparent substrate 1.

Alternatively, the step S23 is performed simultaneously with the step S22, although the step S22 and the step S23 may be performed sequentially.

Alternatively, the pressing of the copper powder 3 in step S23 is not the only way, and for example, after the copper powder 3 is thrown and the ultraviolet curing step is completed, a flat weight is used to press the copper powder 3 to further penetrate the particles of the copper powder into the adhesive 2 on the transparent substrate 1.

The method of removing the particles of the excess copper powder in step S3 is not limited to a particular method, and this embodiment gives a preferable idea to understand that the pattern of the copper powder-coated wire 30 covered with the particles of the copper powder is formed by blowing away the excess copper powder particles that are not solidified by the binder 2 using a prescribed flushing device 8 such as a high-pressure air gun or a fan or flushing away the excess copper powder particles using running water. For the sake of convenience of distinction, the intermediate body including the copper-clad wiring 30 and the transparent substrate 1 is named a copper-clad substrate 200.

In the copper-clad substrate 200 obtained in steps S1, S2, and S3, the copper powder 3 adheres to the inside of the binder 2 in the form of particles, the particles do not come into close contact with each other, and effective conductive performance cannot be achieved.

Alternatively, as a preferred example of the present invention, the gap may be filled using a copper deposition process. As shown in fig. 6, step S4 specifically includes the following steps:

in step S41, the copper deposition process includes: the transparent substrate 1 including the copper-clad wiring 30 is subjected to a copper deposition process to deposit copper ions 9 into gaps between particles of the copper powder.

The copper deposition process is a prior art process, and is not described herein again. Since copper ions 9 are more easily attached to the positions where copper powder particles exist, in the present embodiment, the transparent substrate 1 including the copper-clad wire 30 is subjected to a copper deposition process, so that the copper ions 9 are deposited on the transparent substrate 1, and the copper ions 9 fill the gaps between the copper powder particles, as shown in fig. 7, so that the copper-clad wire 30 is more compact and the electrical conductivity is enhanced.

In step S42, a washing and drying step: removing excessive copper ions falling on the transparent substrate 1 after the copper deposition process treatment, and then drying the transparent substrate 1 in a dust-free state.

The excess copper ions are copper ions falling on the transparent substrate 1 except the copper-clad wiring 30. The method of removing the excess copper ions in step S42 is not limited to a specific manner, and the present embodiment gives a preferable solution to understand that the excess copper ions are blown off by using a specific cleaning tool 8, such as a high pressure air gun or a fan, or flushed off by using running water. The cleaned transparent substrate 1 is then dried in a dust-free state. Preferably, the drying may be performed by blowing with a fan or high-pressure gas, or by heating and drying at a low temperature.

Filling gaps between copper powder particles by the copper deposition process of the step S41 to form a circuit pattern 40, and then cleaning and drying the circuit pattern 40 in the step S52 to obtain an intermediate body including the circuit pattern 40 and the transparent substrate 1; for the sake of convenience of distinction, the transparent substrate 1 including the circuit pattern 40 is referred to herein as a transparent circuit board 300.

Alternatively, as another preferable example of the present invention, the gap may be filled with a tin powder melting process. It also goes through steps S1-S3, and the processed results are shown enlarged by a microscope in this example in order to make the skilled person understand the results. Fig. 12 is a schematic diagram of the circuit filled with copper particles according to this embodiment. In the figure, the white portions indicate copper powder 3 particles, and the black portions indicate gaps between the particles, and it can be seen that the copper powder 3 is adhered in the form of particles in the binder 2, and the contact between the particles is not tight, and an effective conductive performance cannot be obtained.

In this example, the step S4 is different, and as shown in fig. 8, the step S4 specifically includes the following steps:

in step S81, a tin powder scattering step: and (3) throwing tin powder 10 on the front surface of the transparent substrate 1 to cover the copper-coated circuit 30 on the transparent substrate 1.

Here, the tin powder 10 has a particle diameter of 30 to 50 nm. The tin powder 10 is scattered on the transparent substrate 1 including the copper-clad wire 30, so that the tin powder 10 covers the transparent substrate 1, particularly the copper-clad wire 30.

In step S82, a tin powder press bonding step: pressure is applied to the tin powder 10 to embed particles of the tin powder into gaps between the particles of the copper powder on the copper-clad wire 30.

As a preferred example of the present invention, as shown in fig. 9, this step S82 is implemented by using a roller 7 to press the tin powder 10 from one end to the other end over the tin powder 10 (the roller 7 rolls from the right side to the left side of the paper surface in the figure), and pressing the tin powder 10 into the gaps between the copper powder particles, that is, by rolling the roller 7 so that the tin powder particles are further embedded into the gaps between the copper powder particles.

In step S83, the melting filling step: removing the redundant tin powder on the transparent substrate 1, and then heating the transparent substrate 1 to a preset temperature to melt and flow the tin powder 10 and fill gaps among copper powder particles.

Wherein the excess tin powder is tin powder that falls on the transparent substrate but is not embedded in gaps between particles of copper powder. The method of removing the excess tin powder in step S83 is not limited to a specific method, and this embodiment provides a preferable solution to understand that the excess tin powder falling on the transparent substrate 1 is blown away by using a designated flushing device 8, such as a high pressure air gun or a fan, or flushed away by using running water. Then heating the box body to a preset temperature, for example, the melting temperature of the tin powder 10 is 260 ℃, placing the transparent substrate 1 without the redundant tin powder in the box body, and heating and melting the tin powder 10 to form liquid tin; the liquid tin will flow along the gaps between the particles of copper powder and fill the gaps there through; after the liquid tin is completely melted and permeates gaps among particles of the copper powder, taking out the transparent substrate 1 from the box body, cooling, and solidifying and forming the liquid tin again to obtain a circuit pattern 40; for the sake of convenience of distinction, the transparent substrate 1 including the circuit pattern 40 is referred to herein as a transparent circuit board 300. As shown in fig. 13, fig. 13 is a partial image of the conductive circuit enlarged by a microscope after the tin powder is melted and filled according to this embodiment. It is apparent that only after the tin powder is melted and filled, the black portion indicating the gap is reduced. Due to the filling of the tin powder, the copper-clad line 30 on the transparent circuit board 300 is more compact, and the conductivity is further enhanced.

Optionally, in this embodiment, the transparent substrate 1 is a high-temperature-resistant transparent glass substrate, preferably tempered glass, and has a thickness of 2-10 mm.

In this example, the circuit pattern 40 may be in a manner known to those skilled in the art, for example, as shown in fig. 10-11, the circuit pattern 40 includes a power pad 40b, a signal pad 40c, and bead lands for mounting LED beads arranged in an array;

each lamp bead welding area is provided with a pin bonding pad 40a corresponding to a pin of the LED lamp; the pin pad 40a includes a signal pin pad and an electrode pin pad;

signal wires for signal transmission are arranged between the signal bonding pad 40c and the signal pin bonding pad in the lamp bead welding area and between the signal pin bonding pads in the adjacent lamp bead welding areas in the same row or the same column; for the sake of distinction, a signal line between the signal pad 40c and a signal pin pad in the bead soldering zone is marked as a first signal line 40 e; a signal wire used for signal transmission between signal pin bonding pads in adjacent lamp bead welding areas in the same row or the same column is marked as a second signal wire 40 f; control signals for controlling the on and off of the LED lamp beads can be input from the signal bonding pad 40c and then transmitted in sequence through the LED lamp beads;

and electrically connecting the electrode pin pad on the lamp bead welding area with the power supply pad 40b with the same polarity through a power line 40 d.

According to the manufacturing method of the transparent circuit board, the circuit pattern 40 with copper as a conductive material can be directly formed on the transparent substrate 1, the conductive requirement of a high-power electronic component can be met, and meanwhile, the high transparency of a finished product can be guaranteed, so that the using requirement of a transparent LED display screen can be met. The circuit pattern 40 formed by the method not only enables the copper powder 3 and the transparent substrate 1 to be firmly bonded, but also greatly enhances the electric conductivity by filling gaps among particles of the copper powder; the adhesive force between the circuit pattern 40 and the transparent substrate 1 is still very stable after high-temperature reflow soldering, and the circuit pattern does not deform and fall off.

Example 2

The present embodiment will specifically explain the manufacturing method of the transparent LED display screen provided by the present invention, which includes the following steps: manufacturing a transparent circuit board 300; mounting an LED lamp on the transparent circuit board 300, and then packaging;

the method for manufacturing the transparent circuit board 300 is the method for manufacturing the transparent circuit board provided in embodiment 1.

The LED lamp is installed on the lamp bead welding area by adopting a Surface Mounting Technology (SMT) method and limiting the reflow soldering temperature in the SMT processing process to be about 260 ℃. And then, a waterproof protective layer is formed on the transparent circuit board 300 after the LED is mounted through glue pouring and packaging, and then a protective cover plate is adopted for protection.

In this embodiment, the key point lies in the manufacturing method of the transparent circuit board 300, and other subsequent packaging processes are known, and the manufacturing method of the transparent circuit board 300 is explained in embodiment 1. Therefore, the description is omitted.

According to the manufacturing method of the transparent circuit board 300, when the transparent circuit board 300 is manufactured, the circuit pattern 40 with copper as a conductive material can be directly formed on the transparent substrate 1, and gaps among particles of the copper powder are filled, so that the conductivity is greatly enhanced, the conductive requirement of electronic components with high power can be met, and meanwhile, the finished product can have high transparency, so that the use requirement of the transparent LED display screen can be met. The circuit pattern 40 formed by the method not only enables the copper powder 3 and the transparent substrate 1 to be firmly bonded, but also can resist the reflow soldering temperature in the SMT processing process of electronic components, and the bonding force of the circuit pattern 40 and the transparent substrate 1 is still very stable after high-temperature reflow soldering, and the circuit pattern is not deformed and does not fall off. The manufacturing process of the method can be carried out at normal temperature.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A manufacturing method of a transparent circuit board is characterized by comprising the following steps:

manufacturing a binder circuit on a transparent substrate by a screen printing process;

and (3) throwing tin powder to the copper-clad circuit, pressing, heating and melting to fill gaps among copper powder particles to form a circuit pattern.

2. The method for manufacturing a transparent circuit board according to claim 1, wherein the "manufacturing an adhesive line on a transparent substrate by a screen printing process" includes:

3. The method of claim 2, wherein the adhesive line has a width of 0.1 mm or more.

4. The method of claim 1, wherein the adhesive is a UV glue;

the step of uniformly spreading copper powder on the transparent substrate including the binder circuit and then pressing and infiltrating the copper powder into the binder circuit comprises the following steps:

5. The method for manufacturing a transparent circuit board according to claim 4, wherein the particle diameter of the copper powder is 500-1000 nm.

6. The method of manufacturing a transparent circuit board according to claim 1, wherein the step of spraying tin powder to the copper-clad circuit, pressing, and heating to melt the tin powder to fill gaps between copper powder particles to form a circuit pattern comprises:

7. The method of manufacturing a transparent circuit board according to claim 6, wherein the tin powder has a particle diameter of 30 to 50 nm.

8. The method of claim 6, wherein the predetermined temperature is 260 ℃.

9. The method of manufacturing a transparent circuit board according to any one of claims 1 to 8, wherein the transparent substrate is a high temperature-resistant transparent glass substrate.

10. The method of manufacturing a transparent circuit board according to any one of claims 1 to 8, wherein the circuit pattern includes a power supply pad, a signal pad, and bead lands for mounting LED beads arranged in an array;

11. A manufacturing method of a transparent LED display screen comprises the following steps: manufacturing a transparent circuit board, mounting an LED lamp on the transparent circuit board, and then packaging, wherein the method for manufacturing the transparent circuit board is the method for manufacturing the transparent circuit board according to any one of claims 1 to 10.