CN107734868B

CN107734868B - Fine wire circuit and preparation method thereof

Info

Publication number: CN107734868B
Application number: CN201711091379.1A
Authority: CN
Inventors: 郑莉; 王翀; 梁坤; 程骄; 肖定军
Original assignee: Guangdong Guanghua Science And Technology Co Ltd
Current assignee: Guangdong Guanghua Science And Technology Co Ltd
Priority date: 2017-11-08
Filing date: 2017-11-08
Publication date: 2020-01-03
Anticipated expiration: 2037-11-08
Also published as: CN107734868A

Abstract

The invention relates to a fine conductor circuit and a preparation method thereof, wherein the preparation method comprises the following steps: (1) preparing a slurry, wherein the slurry comprises metal ions and a reducing agent; (2) spreading the slurry on the surface of a substrate; (3) irradiating the slurry by using laser to reduce metal ions into metal simple substances to form a circuit; (4) and cleaning the unreacted slurry to obtain the fine conductor circuit. The above-mentioned fine wiring line manufacturing method (direct writing technique) is a method of forming a circuit or a conductive pattern by causing a chemical or photochemical reaction between a substrate and a paste by the action of light or heat of laser on the surfaces of the substrate and the paste. The direct writing technology is suitable for any substrate because of its extremely high precision and no need of mask.

Description

Fine wire circuit and preparation method thereof

Technical Field

The invention relates to the field of electronic component manufacturing, in particular to a fine lead line and a preparation method thereof.

Background

With the popularization of networks and the rapid development of electronic communications, electronic terminal products are required to be miniaturized while product performance is required to be improved continuously, and High Density Interconnection (HDI) technology is required to be developed at the same time. The HDI technique refers to a multilayer printed circuit board formed by coating an insulating medium on an insulating substrate or a conventional printed circuit board, forming lines and vias through chemical plating and electroplating, and finally, stacking a plurality of times. The traditional HDI preparation method mainly comprises a subtractive method and an additive method. The subtractive method is also called copper etching method, and is a method for selectively removing copper foil on a copper-clad plate to obtain a conductive pattern; additive processes are processes that selectively deposit metal on the surface of an insulating substrate to form a conductive pattern. However, regardless of whether a subtractive method or an additive method is used, the steps of exposure, development, etching, and the like are repeatedly used to obtain a conductive pattern. These processes not only have long process, but also form a large amount of waste water to pollute the environment and consume a large amount of resources, and based on the current situation, a method for manufacturing a metal circuit by using a laser direct writing technology is provided.

The conventional methods for reducing, semi-adding and fully adding the HDI board or the packaging substrate have the defects of long process, time consumption for exposure, development and etching and material consumption.

Therefore, the prior art is in need of improvement.

Disclosure of Invention

Based on this, the object of the present invention is to provide a method for manufacturing a fine wiring line.

The specific technical scheme is as follows:

a method for preparing a fine conductor line comprises the following steps:

(1) preparing a slurry, wherein the slurry comprises metal ions and a reducing agent;

(2) spreading the slurry on the surface of a substrate;

(3) irradiating the slurry by using laser to reduce metal ions into metal simple substances to form a circuit;

(4) and cleaning the unreacted slurry to obtain the fine conductor circuit.

In some of these embodiments, the slurry includes a solvent and the following components:

100-400 g/L of metal ions

15-300 g/L reducing agent

0.01-5 g/L of viscosity regulator

1-10 g/L of antioxidant.

In some of these embodiments, the metal ion is selected from ions of elemental metals from groups IVB, VB, VIB, VIIB, VIII, IB, IIB, IIIB, IVA, VA.

In some of these embodiments, the metal ion is selected from Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sn, Ag, Pd, or Pt.

In some of these embodiments, the reducing agent is selected from glyoxylic acid, oxalic acid, formaldehyde, acetic acid, hydrazine hydrate, a saccharide, or a polysaccharide.

In some of these embodiments, the viscosity modifier is selected from methylcellulose, hydroxypropyl methylcellulose, sodium hydroxymethyl cellulose, hydroxyethyl cellulose, starch, gelatin, agar, paraffin, microcrystalline wax hydroxylamine sulfate, or ethylene glycol; the antioxidant is selected from: ascorbic acid, tocopherol, tert-butyl hydroquinone or tea polyphenols; the solvent is selected from water, methanol, ethanol, propanol, n-butanol, isobutanol, acetone, butanone, benzene, carbon tetrachloride, dichloromethane, diethyl ether, methyl formate, methyl acetate, acetonitrile, pyridine, phenol, dimethyl sulfoxide or tetrahydrofuran.

In some of these embodiments, the laser has a spot diameter of 500nm to 50 μm and a laser wavelength in the range of 193nm to 1650 nm.

In some embodiments, the substrate is selected from a glass substrate, a polyimide substrate, an epoxy resin substrate, an acrylonitrile-butadiene-styrene substrate, an FR-4 substrate, or an alumina ceramic substrate.

In some of these embodiments, the method of making further comprises the steps of:

(5) and thickening the circuit by adopting a chemical or electroplating method.

Another object of the present invention is to provide a fine wire line.

The fine conducting wire circuit prepared by the preparation method.

The principle and advantages of the invention are as follows:

the laser is generated based on a stimulated emission amplification principle, has the advantages of extremely high energy, strong stability, long service life, small spot diameter, directional light emission, adjustable wavelength and the like, and is widely applied to the aspects of medical treatment, industrial production, communication, aerospace and the like in recent years. The above-mentioned fine wiring line production method (direct writing technique) is a method of forming a circuit or a conductive pattern by causing a chemical or photochemical reaction between a substrate and a paste by the action of light or heat of laser on the surfaces of the substrate and the paste. The direct writing technology is suitable for any base material because of extremely high precision and no need of a mask. As the line width and line pitch of the printed circuit board are smaller and smaller, the conventional mask method is also more and more difficult to manufacture fine lines, and the diameter of the laser spot is only 500nm to 50 μm, so that the direct writing technique has incomparable advantages to the conventional method for forming the conductive pattern. With the development of numerical control technology, the micron-sized contraposition operation technology is increasingly perfect, so that the laser direct writing technology becomes the leading technology of the conductive pattern in the future.

In recent years, the laser direct writing technology is applied to many aspects, such as the preparation of a microarray with a multilevel structure by using the laser direct writing technology, but mainly uses photoresist, exposure, development and the like, the laser direct writing technology is only used as an exposure light source, and the defect of low mask plate precision is overcome by using the characteristic of small light spot. And the mask plate which is ultrahigh in resolution and can be repeatedly used is manufactured by using a laser direct writing technology, the thermal etching stripping material is etched by using the characteristic of high laser energy, and then the ultrahigh resolution mask plate is manufactured by using the characteristics of small light spot and reversible saturated nonlinear absorption of a film material. The preparation method of the fine conducting wire circuit integrates the deposition of metal and the formation of the circuit into a process, simplifies the working procedures and improves the production efficiency

The preparation method of the fine conducting wire circuit forms the circuit by using the laser direct writing technology, and has incomparable advantages for the increasingly-reduced line width and line distance because the diameter of a laser spot is dozens of microns and even reaches the nanometer level. Meanwhile, compared with the traditional subtractive method or additive method process, the method avoids the generation of a large amount of waste water, environmental pollution and resource waste caused by repeated use of pattern transfer technologies such as exposure, development, etching and the like. In addition, the processes of the addition method and the subtraction method are both long and complex, a large amount of manpower and material resources are needed, and the production efficiency can be greatly improved by the laser direct writing technology. In addition, since the laser direct writing technology has no limitation on the substrate, it is also a great advantage for manufacturing flexible printed circuit boards.

Detailed Description

In order that the invention may be more fully understood, reference will now be made to the following description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

A preparation method of a fine conductive circuit comprises the following steps:

the method comprises the following steps: preparing a slurry, wherein the slurry comprises metal ions and a reducing agent; it is understood that viscosity modifiers, antioxidants and solvents may also be included;

step two: performing surface treatment on the substrate material to be coated with the slurry to enhance the bonding force between the substrate material and the metal wire (optional step);

step three: irradiating the slurry by laser to enable the reducing agent and metal ions to react to form a fine circuit;

step four: washing and removing unreacted slurry;

step five: the formed fine circuit is thickened by electroplating or chemical plating to form a final circuit pattern (optional step).

In the first step, the slurry mainly comprises a metal ion compound, a reducing agent and auxiliary materials such as a viscosity regulator, an antioxidant and a solvent.

The metal ions comprise the following components: the ions of metallic elements of IVB, VB, VIB, VIIB, VIII, IB, IIB, IIIB, IVA and VA are preferably selected from Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sn, Ag, Pd and Pt.

The reducing substance comprises the following components: the metal ions can be decomposed and reduced by irradiation with laser light, and specifically, glyoxylic acid, oxalic acid, formaldehyde, acetic acid, hydrazine hydrate, saccharides and polysaccharides are mentioned.

The viscosity regulator is the following materials but not limited to: methylcellulose, hydroxypropyl methylcellulose, sodium hydroxymethyl cellulose, hydroxyethyl cellulose, starch, gelatin, agar, paraffin, microcrystalline wax hydroxylamine sulfate, cyclo-ethanol, and the like.

The antioxidant is the following materials but not limited to: ascorbic acid, tocopherol, tert-butyl hydroquinone, tea polyphenols, etc.;

the solvent is the following materials but not limited to: water, methanol, ethanol, propanol, n-butanol, isobutanol, acetone, butanone, benzene, carbon tetrachloride, dichloromethane, diethyl ether, methyl formate, methyl acetate, acetonitrile, pyridine, phenol, dimethyl sulfoxide, tetrahydrofuran, and the like;

the substrate material in step two is not limited to the following materials: glass substrate materials, polyimide substrate materials, epoxy resin substrate materials, acrylonitrile-butadiene-styrene (ABS) substrate materials, FR-4 substrate materials, alumina ceramic substrates and the like.

Preferably, the second step further comprises:

(1) and cleaning the surface of the substrate by using clear water and degreasing the substrate material. The oil removing mode comprises acid oil removing, alkaline oil removing and electrolytic oil removing, and different oil removing modes are selected according to different base materials;

(2) swelling and wetting the surface of the substrate by using an organic solvent (not necessarily as a preferred mode);

(3) microetching the substrate surface with an oxidizing agent or heating and sonicating while microetching or surface roughening with plasma (not necessarily as a preferred means);

(4) and cleaning the surface of the substrate by using clean water and drying.

The chemical principle of the method in the third step is as follows: the laser irradiation of the slurry is to make the reducing agent component in the slurry thermally decompose into an active reducing agent or generate a photochemical reaction to form the active reducing agent, and the active reducing agent reacts with the metal ions to generate a metal simple substance so as to form a circuit.

The fifth step is further as follows: the circuit formed by laser direct writing is thickened by using an electroplating or chemical plating method, so that the reliability of the circuit is improved. Preferably, the thickening method is sulfate copper plating, and the main components are copper sulfate pentahydrate, sulfuric acid and other additives (such as sodium polydithio dipropyl sulfonate, polyethylene glycol, organic ammonium salt and the like).

Example 1

The method for manufacturing the fine conducting wire circuit by using the mixed slurry of the copper acetate monohydrate and the acetic acid comprises the following specific steps:

(1) mixing copper acetate monohydrate and acetic acid and adding a methyl cellulose aqueous solution to form a slurry (viscosity of 10.2 pas): 620g/L of copper acetate monohydrate, 130g/L of acetic acid, 8g/L of hydroxymethyl cellulose and 10g/L of antioxidant (ascorbic acid);

(2) treating the surface of the glass substrate by using sodium hydroxide and carrying out ultrasonic heating treatment for 30 min;

(3) uniformly coating the slurry on a glass substrate (the thickness of the slurry is about 100 mu m), and forming a line by laser irradiation (the spot diameter of the laser is 500nm-50 mu m, and the laser wavelength is 193nm-1650 nm);

(4) drying the glass substrate, and cleaning the redundant slurry;

(5) the wire portion was stuck with an adhesive tape and then torn off, and no powder was found to fall off.

Example 2

The method for manufacturing the fine conducting wire circuit by using the titanium acetylacetonate and the ethanol to form the circuit with the titanium as the flexible substrate material comprises the following specific steps:

(1) titanium acetylacetonate was mixed with ethanol, isopropanol and water to form a slurry (viscosity 9.52Pa · s): 260g/L of titanium acetylacetonate, 50g/L and 60g/L of reducing agent ethanol and isopropanol, 10g/L of viscosity regulator (hydroxymethyl cellulose) and 15g/L of antioxidant (ascorbic acid);

(2) treating the PI flexible substrate material by using plasma, and washing by using clear water;

(3) uniformly coating the slurry on a PI substrate (the thickness of the slurry is about 100 mu m), and irradiating by using laser to form a circuit;

(4) and removing the excess slurry on the substrate.

Example 3

The method for manufacturing the fine conductor line on the epoxy resin by using the ferrous oxalate and the acetonitrile comprises the following specific steps:

(1) iron oxalate, acetonitrile and water were used as a slurry (viscosity 6.6Pa · s): 150g/L of ferrous oxalate (oxalic acid root is used as a reducing agent), 15g/L of viscosity regulator (gelatin), and 12g/L of antioxidant (tea polyphenol);

(2) carrying out surface roughening on the epoxy resin substrate by using chromic acid and sulfuric acid, and then cleaning and drying by using clear water;

(3) uniformly coating the slurry on an epoxy resin substrate (the thickness of the slurry is about 100 mu m), and forming a circuit by laser irradiation (the spot diameter of the laser is 500nm-50 mu m, and the laser wavelength range is 193nm-1650 nm);

(4) removing the redundant slurry on the substrate and drying;

(5) the manufactured circuit is thickened by using chemical nickel plating.

Example 4

The method for manufacturing the fine conducting wire circuit on the ABS substrate by using the cobalt acetate and the acetic acid comprises the following specific steps:

(1) a slurry (viscosity 8Pa · s) was prepared using cobalt acetate, acetic acid and water: 350g/L of cobalt acetate, 130g/L of acetic acid, 3g/L of viscosity regulator (agar) and 16g/L of antioxidant (tert-butylhydroquinone);

(2) carrying out surface roughening on the epoxy resin substrate by using chromic acid and sulfuric acid, and then cleaning by using clear water and drying;

(4) and removing the redundant slurry on the substrate, drying, and forming a circuit after the manufacture is finished.

Example 5

The method for manufacturing the fine conductor circuit on the epoxy resin substrate by using the copper acetate monohydrate and the acetic acid comprises the following specific steps:

(1) water and methylcellulose were added using copper acetate monohydrate and acetic acid to form a slurry (viscosity 9.84Pa · s): 400g/L of copper acetate monohydrate, 100g/L of acetic acid, 15g/L of viscosity regulator (hydroxyethyl cellulose) and 10g/L of antioxidant (ascorbic acid).

(2) Carrying out surface roughening on the epoxy resin substrate by using chromic acid and sulfuric acid, cleaning by using water and drying;

According to the tape test method, a 3M tape is used for adhering and pulling a fine circuit formed by laser, and no powder dropping phenomenon or circuit dropping phenomenon occurs. The fine conductive line prepared by the method has good bonding force with the substrate. The circuit has good conductivity and strong catalytic capability, and can be thickened by electroplating or chemical plating.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A method for preparing a fine conductor line is characterized by comprising the following steps:

(2) spreading the slurry on the surface of a substrate;

(4) cleaning the unreacted slurry to obtain the fine conductor circuit; the step of (2) spreading the slurry on the surface of the substrate further comprises a surface treatment step, wherein the surface treatment step comprises the following steps:

cleaning the surface of the substrate by using clear water and removing oil on the surface of the substrate;

carrying out swelling wetting on the surface of the substrate by using an organic solvent;

carrying out micro-etching on the surface of the substrate by using an oxidant, or heating and carrying out ultrasound while carrying out the micro-etching or carrying out roughening on the surface of the substrate by using plasma;

cleaning and drying the surface of the substrate by using clear water;

the slurry comprises a solvent and the following components:

the viscosity regulator is selected from methylcellulose, hydroxypropyl methylcellulose, sodium hydroxymethyl cellulose, hydroxyethyl cellulose, starch, gelatin, agar, paraffin, microcrystalline wax hydroxylamine sulfate or ethylene glycol.

2. The method according to claim 1, wherein the metal ions are selected from the group consisting of ions of metallic elements of groups IVB, VB, VIB, VIIB, VIII, IB, IIB, IIIB, IVA, VA.

3. The method according to claim 2, wherein the metal ion is selected from the group consisting of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sn, Ag, Pd and Pt.

4. The method according to claim 1, wherein the reducing agent is selected from glyoxylic acid, oxalic acid, formaldehyde, acetic acid, hydrazine hydrate, or a saccharide.

5. The method of claim 1, wherein the antioxidant is selected from the group consisting of: ascorbic acid, vitamin C, tocopherol, tert-butyl hydroquinone or tea polyphenols.

6. The method according to claim 1, wherein the solvent is selected from water, methanol, ethanol, propanol, n-butanol, isobutanol, acetone, methyl ethyl ketone, benzene, carbon tetrachloride, methylene chloride, diethyl ether, methyl formate, methyl acetate, acetonitrile, pyridine, phenol, dimethyl sulfoxide, and tetrahydrofuran.

7. The production method according to any one of claims 1 to 6, wherein the laser has a spot diameter of 500nm to 50 μm and a laser wavelength in a range of 193nm to 1650 nm.

8. The method according to any one of claims 1 to 6, wherein the base is made of a material selected from a glass base material, a polyimide base material, an epoxy resin base material, an acrylonitrile-butadiene-styrene base material, an FR-4 base material, and an alumina ceramic substrate.

9. The method of any one of claims 1 to 6, further comprising the steps of:

(5) and thickening the circuit by adopting a chemical or electroplating method.

10. A fine wiring line produced by the production method as set forth in any one of claims 1 to 9.