WO2017113325A1 - Method of preparing patterned conductive material - Google Patents

Abstract

A method for preparing a patterned conductive material, the method comprising: applying a photosensitive material on at least one surface of a flexible substrate material (S101), then forming a circuit pattern by removing the photosensitive material from the circuit pattern area (S102), and forming a metal conductive layer on the surface of the circuit pattern so as to acquire a patterned conductive material (S103). The method enables, via a one-step pattern electroplating process, the preparation of a final desired circuit pattern, simplifying the process flow and improving efficiency.

Description

Method for preparing graphic conductive material

[Technical Field]

 The present invention relates to the field of electronic technologies, and in particular, to a method for preparing a patterned conductive material.

 【Background technique】

In recent years, the electronics industry has developed rapidly, and flexible electronics has also developed rapidly as a new thing. Flexible electronics is an emerging electronic technology that makes organic and inorganic electronic devices on flexible, ductile plastic or thin metal substrates. It has broad application prospects in information, energy, medical, defense and other fields, especially in notebook computers. Tablet computers, smart phones and consumer electronics.

The flexible circuit board FPC is a highly reliable and excellent flexible printed circuit made of polyimide or polyester film. In recent years, more and more mobile devices (such as mobile phones, MP3 players and notebook computers) use FPC connectors for impact-resistant back-locking mechanism connector applications. FPC connectors are mainly used in liquid crystal displays, scanners, etc. Electronic equipment, widely used in computer motherboards, liquid crystal displays, telecommunications cards, storage, mobile hard drives, including mobile devices.

The existing flexible circuit board is usually prepared by plating a complete metal layer on the surface of the flexible material, and then transferring the line to be formed to the surface of the metal layer by a pattern transfer technique, and then performing a chemical etching process on the metal layer without conducting electricity. The area is etched to form a conductive line. The process involves two processes, electroplating and etching, with complex process flow, low production efficiency, and high cost.

 [Summary of the Invention]

The invention provides a preparation method of a graphic conductive material, which can directly form a conductive line required on a surface of a flexible material, simplify a process flow, improve production efficiency, improve production precision and save material cost.

In order to solve the above technical problem, the present invention provides a technical solution for providing a method for preparing a patterned conductive material, the method comprising: applying a photosensitive material on at least one surface of a flexible substrate material; Forming a circuit pattern thereon and removing the photosensitive material outside the circuit pattern region; forming a metal conductive layer on the surface of the circuit pattern to obtain the patterned conductive material.

Wherein, the photosensitive material is a photosensitive dry film or a photosensitive ink.

Wherein, when the photosensitive material is a photosensitive dry film, the step of applying the photosensitive material on at least one surface of the flexible base material comprises: at a temperature of 80-120 ° C and a pressure of 0.5-0.7 MPa, 1.0-3.0 The speed of m/min is applied to the photosensitive material on at least one surface of the flexible substrate material.

Wherein the step of removing the photosensitive material outside the circuit pattern region comprises: exposing the photosensitive material forming the circuit pattern, and then processing by the developer to expose the circuit pattern region.

Wherein, the photosensitive material forming the circuit pattern is exposed by film or direct exposure; the developing solution is a potassium carbonate or sodium carbonate solution.

Wherein, the potassium carbonate has a mass fraction of 0.8% to 1.2% and a temperature of 28 to 32 °C.

Wherein, before the step of forming a metal conductive layer on the surface of the circuit pattern to obtain the graphic conductive material, the method further comprises: sensitizing and activating the material obtained after the removing step.

Wherein the step of sensitizing and activating the material obtained after the removing step comprises: immersing the material obtained after the removing step with stannous chloride, and then sequentially washing with deionized water and hydrogen peroxide The sensitized material is obtained; the sensitized material is immersed in silver nitrate to complete the activation treatment.

Wherein, the concentration of the stannous chloride is 30-50 g/L, the soaking time of the material in the stannous chloride is 5-10 min, the volume fraction of the hydrogen peroxide is 10-15%, and the cleaning time by the hydrogen peroxide is 3 The concentration of the silver nitrate is 10-15 g/L, and the material is immersed in the silver nitrate for 3-5 min.

Wherein, the metal conductive layer is one or more layers, and the metal conductive layer is a pure metal layer and/or a metal alloy layer.

Wherein the metal conductive layer is a combined layer of a metal silver layer, a metal copper layer and a metal tin layer, and the step of plating the metal conductive layer on the surface of the circuit pattern comprises: sequentially forming the surface on the circuit pattern surface A metal silver layer is then formed on the surface of the metal silver layer, and finally the metal tin layer is formed on the surface of the metal copper layer.

Wherein, the metal silver layer has a thickness of 0.2 to 0.5 μm, the metal copper layer has a thickness of 5 to 10 μm, and the metal tin has a thickness of 2 to 5 μm.

Wherein, a metal silver layer is formed on the surface of the circuit pattern by electroless silver plating, a copper metal layer is formed on the surface of the metal silver layer by electroplating copper pyrophosphate, copper electroplating copper or cyanide plating, and The metal tin layer is formed on the surface of the metal copper layer by acid plating or alkaline plating.

Wherein, before the step of applying the photosensitive material on at least one surface of the flexible substrate material, the method further comprises: treating the flexible substrate material with a degreaser to obtain a surface-cleaned flexible substrate material.

Wherein, the degreaser comprises the following components: 5-15 g/L of sodium hydroxide, 30-50 g/L of sodium carbonate, 50-60 g/L of trisodium phosphate, and 1-3 g/L of OP emulsifier; The step of treating the flexible substrate material with a degreaser comprises: soaking the flexible substrate material in the degreaser at 40-70 ° C for 1-3 min.

Wherein, the flexible substrate material is a fabric substrate material.

Wherein, the fabric base material is at least one of cotton, hemp, acrylic, polyester and nylon.

The beneficial effects of the present invention are: different from the prior art, the present invention applies a photosensitive material on at least one surface of a flexible substrate material, then forms a circuit pattern on the photosensitive material, and removes the photosensitive material outside the circuit pattern region, A metal conductive layer is formed on the surface of the circuit pattern to obtain a patterned conductive material. The method of the invention forms the final desired circuit pattern by one-step molding through the pattern electroplating process, omitting the subsequent line processing technology of the flexible conductive material, simplifying the process flow and improving the efficiency, and improving the line production precision.

 [Description of the Drawings]

1 is a flow chart of a method for preparing a patterned conductive material according to an embodiment of the present invention.

【detailed description】

The invention will now be described in detail in conjunction with the drawings and embodiments.

The method for preparing the graphic conductive material provided by the embodiment of the present invention, through the pattern plating process, the final desired circuit pattern is formed by one-time molding, the subsequent line processing technology of the flexible conductive material is omitted, the process flow is simplified, the efficiency is improved, and the line is improved. Production accuracy.

Please refer to FIG. 1. FIG. 1 is a flowchart of a method for preparing a patterned conductive material according to an embodiment of the present invention. As shown in the figure, a method for preparing a patterned conductive material of the embodiment includes the following steps:

S101: Applying a photosensitive material to at least one surface of the flexible base material.

Wherein, the photosensitive material described in the embodiment of the invention is sensitive to light, and changes after being exposed to light, and a photocuring reaction can occur rapidly in the exposed area, so that the physical properties of the material, especially solubility, pro There is a significant change in the nature of the combination. The soluble fraction is dissolved by a suitable solvent to give a material of the desired image. Specifically, the photosensitive material is divided into two types, one is to form an insoluble matter after illumination (that is, the photosensitive material is insoluble in the developer in the exposed region, and the unexposed region is dissolved in the developer to form a desired circuit pattern) One is to form a soluble substance after illumination (that is, the exposed area of the photosensitive material is soluble in the developer, and the unexposed area is insoluble in the developer to form a desired circuit pattern). For example, the photosensitive material of the embodiment of the present invention may be a photosensitive dry film or a photosensitive ink. Among them, the photosensitive dry film refers to a kind of film whose main component is sensitive to a specific spectrum and chemically reacts, and is divided into a negative sexy dry film and a positive sexy dry film, and the negative photosensitive dry film is insoluble in the developing portion, which is sexy. The dried film is partially dissolved in the developer. Photosensitive ink is an ink that is sensitive to ultraviolet light and can be cured by ultraviolet rays.

The flexible substrate material in the embodiment of the present invention refers to a material that can be extrusion-deformed. In a specific implementation, the flexible substrate material of the embodiment may be a fabric, and the fabric refers to a small flexible material passing through a cross or a knot. Or connected to form a flat piece of film, which has the characteristics of being porous, soft, and insulating. The fabric constituting the substrate in this embodiment may be woven from natural fibers, or synthetic fibers, or mixed fibers. For example, the fabric substrate in the embodiment of the present invention may be cotton, hemp, acrylic, polyester, fiberglass, One or more fibrous materials of plastic fibers and nylon are woven, for example, the fabric substrate may be a cotton substrate, or an acrylic substrate, or the like, or a mixed cloth of cotton and acrylic fiber as a substrate.

Wherein, in specific implementation, the photosensitive material is applied to the entire surface of the flexible substrate material. Specifically, the photosensitive material may be applied to one surface of the flexible substrate material, or the photosensitive material may be applied to the opposite surfaces of the flexible substrate material.

In addition, taking the photosensitive material as the photosensitive dry film as an example, in the specific application process, the flexible substrate can be controlled at a temperature of 80-120 ° C and a pressure of 0.5-0.7 MPa at a speed of 1.0-3.0 m/min. At least one surface of the material is coated with a photosensitive material (photosensitive dry film).

Wherein, as a preferred implementation, before the photosensitive material is applied on at least one surface of the flexible substrate material, the flexible substrate material may be treated by a degreaser to clean the surface of the flexible substrate material, thereby facilitating the application of the photosensitive material. .

Wherein, the degreaser can be any one or more chemical components capable of effectively removing oil stains on the surface of the flexible substrate material. As an example, one of the degreasers of the embodiments of the present invention may be a solvent comprising the following components: 5-15 g/L of sodium hydroxide, 30-50 g/L of sodium carbonate, 50-60 g/L of phosphoric acid. Trisodium and 1-3 g/L of OP emulsifier, these components can be mixed in any ratio and used as a degreaser. When the flexible substrate material is specifically treated, the flexible substrate material may be immersed in a degreaser at 40-70 ° C for 1-3 min, and then rinsed to obtain a surface-clean flexible substrate material, which is beneficial to strengthen the photosensitive material and the flexible substrate material. Binding force.

S102: forming a circuit pattern on the photosensitive material and removing the photosensitive material outside the circuit pattern region.

When the graphic conductive material provided by the present invention is applied to an electronic device, the circuit pattern can be used to form all or part of a complete circuit in the electronic device. The electronic device can be a wearable device, such as a smart garment.

Forming a circuit pattern on the photosensitive material specifically refers to transferring a circuit pattern for conducting electricity onto the photosensitive material. As a specific implementation, the photosensitive material forming the circuit is exposed, and the designed circuit pattern may be transferred to a photosensitive material (such as a photosensitive dry film or a photosensitive ink) by means of an exposure machine through film or direct exposure. After transferring the circuit pattern onto the photosensitive material, the exposed photosensitive material is further developed to expose the circuit pattern region.

The developer used in the above development treatment may be any developer capable of treating the exposed photosensitive material. For example, the developer of the embodiment may be potassium carbonate or a sodium carbonate solution. Taking the potassium carbonate solution as a developer as an example, when developing the exposed photosensitive material, the mass fraction of potassium carbonate is preferably 0.8% to 1.2%, and the temperature is preferably 28 to 32 °C.

S103: forming a metal conductive layer on the surface of the circuit pattern to obtain a patterned conductive material.

In the embodiment of the present invention, the metal conductive layer may be disposed in one layer or multiple layers as needed. For example, the metal conductive layer may be a pure metal layer, a metal alloy layer, or a combination of a pure metal layer and a metal alloy layer.

For example, the pure metal layer may be a metal layer composed of copper, silver, gold or tin, and the metal alloy layer may be a metal alloy layer composed of a copper-silver alloy, a lead-tin alloy or a copper-tin alloy.

As a specific implementation of the embodiment of the present invention, the metal conductive layer may be a combined layer of a metal silver layer, a metal copper layer, and a metal tin layer. Among them, since the metallic silver has a good bonding force and at the same time has excellent electrical conductivity and bendability, the metallic silver layer is used as the lowermost layer, and then the metallic copper layer and the metallic tin layer are sequentially formed on the metallic silver layer. Since the metallic tin has good ductility and weldability and is not easily discolored in the air, the metallic tin layer serves as the outermost layer and functions as a protective layer.

In the specific formation process, a metal silver layer may be formed on the surface of the circuit pattern by means of electroless silver plating, for example, 15-30 g/L silver nitrate and 50-80 ml/L ammonia water (27%) and 80-. 120g / L sodium potassium tartrate is mixed as a silver plating solution, the pH of the silver plating solution is controlled to be 11 to 13, the temperature is normal temperature, and the material is immersed in the silver plating solution to form a metallic silver layer. The specific time of the electroless silver plating is determined according to the thickness of the metal silver layer. In the embodiment of the invention, the thickness of the metal silver layer is preferably 0.2-0.5 micrometers, so the preferred electroless silver plating time is 8-12 min.

In the embodiment of the present invention, the metal copper layer and the metal tin layer may be specifically formed by electroplating. For example, a metallic copper layer can be formed on the surface of the metallic silver layer by means of pyrophosphate electroplating copper, sulfate electroplating copper or cyanide electroplating copper. Taking pyrophosphate electroplating copper as an example, a plating solution for electroplating copper is mixed by the following components: 60 to 70 g/L of copper pyrophosphate, 280 to 320 g/L of potassium pyrophosphate, and 15 to 20 g/L of potassium tartrate. Sodium, 15-20 g/L of ammonia triacetic acid and 15-20 g/L of potassium nitrate. The above components may be mixed in a conventional ratio. In the specific copper plating process, the pH of the plating solution is controlled to be 8.2 to 8.8, the temperature is 30 to 40 ° C, and the current density is 0.6 to 1.2 A/dm 2 . The plating time is determined specifically according to the thickness requirement of the metal copper layer. In the embodiment of the invention, the thickness of the metallic copper layer is preferably 5-10 microns, so the preferred plating time is 15-30 min.

In addition, as a specific implementation, a metal tin layer may be formed on the surface of the metal copper layer by means of acid plating of tin or alkaline plating of tin. Taking acid-plated tin as an example, a plating solution for electroplating tin can be mixed by the following components: 40-55 g/L of stannous sulfate, 60-100 g/L of sulfuric acid, 80-100 g/L of cresylic acid, 2 ～3 g/L of gelatin and 0.5 to 1.0 g/L of β-naphthol. The above components can be mixed according to a conventional ratio. In the specific electroplating tin process, the temperature of the plating solution can be controlled to be 15 to 30 ° C, and the current density is 0.5 to 1.5 A/dm 2 . The plating time is determined specifically according to the thickness requirement of the metal copper layer. In the embodiment of the present invention, the thickness of the metal copper layer is preferably 2 to 5 μm, so the preferred plating time is 10 to 25 min.

Wherein, as a preferred implementation, before the metal conductive layer is formed on the circuit pattern, the material may be sensitized and activated to improve the surface activity of the non-conductive flexible substrate material for subsequent formation of the metal conductive layer. ready. For example, the material (specifically, the material obtained after the step S102 described above, including the substrate, the photosensitive material, and the circuit pattern on the surface of the photosensitive material) is soaked in stannous chloride, and then sequentially washed with deionized water and hydrogen peroxide. The sensitization process is completed to obtain a sensitized material. The sensitized material is then immersed in silver nitrate to complete the activation treatment. Among them, in the sensitization treatment, the concentration of stannous chloride can be controlled to be 30-50g/L, the immersion time of the material in stannous chloride is 5-10min, and the volume fraction of hydrogen peroxide is 10-15%, through hydrogen peroxide. The cleaning time is 3-5 min. During the activation process, the concentration of silver nitrate can be controlled to be 10-15 g/L, and the material is immersed in silver nitrate at room temperature for 3-5 minutes.

Based on the above preparation method of the graphic conductive material provided by the embodiment of the present invention, the embodiment of the present invention further provides a graphic conductive material prepared by the above preparation method. The graphic conductive material provided by the present invention can be used as a flexible connecting device for an electronic device or as one of an electromagnetic shielding material, an antistatic material, or a grounding material for these electronic devices. It may also be two or more of electromagnetic shielding materials, antistatic materials, and grounding materials in the electronic device at the same time. When the pattern conductive material of the present invention is used as an electromagnetic shielding material, it has an excellent electromagnetic shielding effect. The electronic device may be a computer, a liquid crystal display, a telecommunication card, a memory or a mobile hard disk.

In one implementation, the electronic device may also be a wearable electronic device such as a smart watch, a smart bracelet, smart glasses, or smart gloves. In a specific implementation, the circuit pattern formed by the metal conductive layer in the patterned conductive material prepared by the embodiment of the present invention can be used as part or all of the circuits of the smart wearable electronic device. Of course, the graphic conductive material can also be used only for intelligence. A connecting device that is in direct contact with human skin on an electronic device. Some electronic components such as sensors and controllers on the smart wearable device are connected to circuit patterns on the graphic conductive material.

In a preferred embodiment, the electronic device may be a smart clothing, wherein the smart clothing includes electronic components such as sensors and electronic circuits, and the circuit pattern formed by the metal conductive layer in the graphic conductive material may be used as a part of the smart clothing. Or all circuits, the sensor can be connected to the above circuit pattern. By using the graphic conductive material provided by the embodiment of the invention, the graphic conductive fabric with the metal conductive pattern can be directly used as the garment fabric to make the smart garment, and the smart garment thus obtained can directly contact the human skin, and has good air permeability and resistance. The bending performance is stronger.

Optionally, the smart garment can also be fabricated by using the plurality of patterned conductive materials with circuit patterns as a garment fabric. Preferably, the multilayer patterned conductive fabric can be processed (eg, by bonding, sewing, etc.) In order to fit each other and make the circuit pattern hidden in the interlayer gap, the smart clothing processed by the multi-layer composite graphic conductive cloth is more convenient for implementing a more complicated circuit design, and is more safe and reliable, and has high durability.

The detailed description of the method for preparing the patterned conductive material mentioned in the above embodiments of the present invention is understood to be that the present invention applies a photosensitive material on at least one surface of the flexible substrate material, then forms a circuit pattern on the photosensitive material, and removes the circuit pattern. A photosensitive material outside the region forms a metal conductive layer on the surface of the circuit pattern, thereby obtaining a patterned conductive material. The method of the invention forms the final desired circuit pattern by one-step molding through the pattern electroplating process, omitting the subsequent line processing technology of the flexible conductive material, simplifying the process flow and improving the efficiency, and improving the line production precision.

The above is only the embodiment of the present invention, and is not intended to limit the scope of the invention, and the equivalent structure or equivalent process transformation of the present invention and the contents of the drawings may be directly or indirectly applied to other related technologies. The fields are all included in the scope of patent protection of the present invention.

Claims (17)

1. A method of preparing a patterned conductive material, the method comprising:

   Applying a photosensitive material to at least one surface of the flexible substrate material;

   Forming a circuit pattern on the photosensitive material and removing the photosensitive material outside the circuit pattern region;

   A metal conductive layer is formed on the surface of the circuit pattern to obtain the patterned conductive material.
2. The preparation method according to claim 1, wherein the photosensitive material is a photosensitive dry film or a photosensitive ink.
3. The preparation method according to claim 2, wherein when the photosensitive material is a photosensitive dry film, the step of applying a photosensitive material on at least one surface of the flexible substrate material comprises: at a temperature of 80-120 ° C and The photosensitive material is applied to at least one surface of the flexible base material at a speed of 1.0 to 3.0 m/min under a pressure of 0.5 to 0.7 MPa.
4. The method according to claim 1, wherein the removing the photosensitive material outside the circuit pattern region comprises:

   The photosensitive material forming the circuit pattern is exposed, and then processed by a developer to expose the circuit pattern region.
5. The preparation method according to claim 4, wherein the photosensitive material forming the circuit pattern is exposed by film or direct exposure; the developer is a potassium carbonate or sodium carbonate solution.
6. The production method according to claim 5, wherein the potassium carbonate has a mass fraction of 0.8% to 1.2% and a temperature of 28 to 32 °C.
7. The method according to claim 1, wherein before the step of forming a metal conductive layer on the surface of the circuit pattern to obtain the patterned conductive material, the method further comprises:

   The material obtained after the removal step is subjected to sensitization and activation treatment.
8. The method according to claim 7, wherein the step of sensitizing and activating the material obtained after the removing step comprises:

   The material obtained after the removing step is soaked in stannous chloride, and then sequentially washed with deionized water and hydrogen peroxide to obtain a sensitized material;

   The sensitized material is immersed in silver nitrate to complete the activation treatment.
9. The preparation method according to claim 8, wherein the concentration of the stannous chloride is 30-50 g/L, the soaking time of the material in the stannous chloride is 5-10 min, and the volume fraction of the hydrogen peroxide is It is 10-15%, the cleaning time by hydrogen peroxide is 3-5 min; the concentration of silver nitrate is 10-15 g/L, and the material is immersed in the silver nitrate for 3-5 min.
10. The preparation method according to claim 1, wherein the metal conductive layer is one or more layers, and the metal conductive layer is a pure metal layer and/or a metal alloy layer.
11. The method according to claim 1, wherein the metal conductive layer is a combined layer of a metal silver layer, a metal copper layer and a metal tin layer, and the step of plating the metal conductive layer on the surface of the circuit pattern comprises :

    The metal silver layer is sequentially formed on the surface of the circuit pattern, and then the metal copper layer is formed on the surface of the metal silver layer, and finally the metal tin layer is formed on the surface of the metal copper layer.
12. The preparation method according to claim 11, wherein the metal silver layer has a thickness of 0.2 to 0.5 μm, the metal copper layer has a thickness of 5 to 10 μm, and the metal tin has a thickness of 2 to 5 Micron.
13. The preparation method according to claim 11, wherein a metal silver layer is formed on the surface of the circuit pattern by electroless silver plating, and copper is electroplated by pyrophosphate, copper is electroplated by copper sulfate or copper is cyanide plated. The metal silver layer is formed on the surface of the metal silver layer, and the metal tin layer is formed on the surface of the metal copper layer by acid plating or alkaline plating.
14. The method according to claim 1, wherein before the step of applying the photosensitive material to at least one surface of the flexible substrate material, the method further comprises:

    The flexible substrate material is treated with a degreaser to obtain a surface clean flexible substrate material.
15. The preparation method according to claim 14, wherein the degreaser comprises the following components: 5-15 g/L of sodium hydroxide, 30-50 g/L of sodium carbonate, and 50-60 g/L of phosphoric acid III. Sodium and 1-3 g/L of OP emulsifier; the step of treating the flexible substrate material with a degreaser comprises: immersing the flexible substrate material in the degreaser at 40-70 ° C. -3min.
16. The preparation method according to any one of claims 1 to 15, wherein the flexible base material is a fabric base material.
17. The preparation method according to claim 16, wherein the woven base material is at least one of cotton, hemp, acrylic, polyester, and nylon.