KR100997993B1 - Circuit board with multi-layer metal line structure and method of fabricating the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board having a metal wiring of a multi-layer structure and a method of manufacturing the same. A first metal wiring layer formed on the substrate and having a first metal particle having a surface capped with a polymer material; And a second metal interconnection layer formed on the first metal interconnection layer, the second metal interconnection layer having a second metal particle on the surface of which is capped with a monomolecular material. The adhesion between the substrates can be improved. In addition, the present invention provides a method of manufacturing a circuit board having a metal wiring of the multilayer sphere.

Metallization, conductive ink, polymer material, capping

Description

Circuit board with multi-layer metal line structure and method of fabricating the same}

The present invention relates to a circuit board having a metal wiring and a method of manufacturing the same, and more particularly, to a circuit board having a metal wiring of a multi-layer structure that can improve the adhesion between the metal wiring and the substrate and a method of manufacturing the same. .

Conventionally, flexible printed circuit boards (FPCBs) that are used in various electronic devices such as mobile phones, PDAs, notebook computers, and printed circuit boards (PCBs) used in general industrial, office or home electrical and electronic devices are used. Copper foil is bonded to the resin film as a whole, and the flexible copper clad laminate (FCCL) or copper clad laminate (CCL) is partially etched through lithography to leave only the desired wiring. It was made after.

However, the process is a process commonly used in semiconductor processing, including a photomask for fabricating a circuit, an expensive equipment such as photoresist coating equipment, exposure equipment, etching equipment and nicking liquid, cleaning equipment and cleaning liquid, and drying equipment. There was a problem in that a complicated and expensive manufacturing process should be performed.

Therefore, various efforts have been attempted to form reliable circuit wiring while improving this problem. One of them is to increase or additionally increase the effective contact area between the metal circuit wiring and the substrate by increasing the surface roughness of the substrate in order to increase the bonding force between the circuit wiring and the substrate. There is a way to give an anchoring effect. However, when the surface roughness of the substrate is increased, if a disadvantage occurs in that the printed circuit wiring becomes uneven due to the surface roughness of the substrate, it is difficult to give a substantial adhesive effect.

Another method is to surface-treat the surface of the substrate to introduce chemical functional groups on the surface of the substrate to increase adhesion to the circuit wiring. However, there is a problem that the chemical treatment method is different depending on the type of metal constituting the substrate and the circuit wiring.

Another method is to form an organic adhesive layer on the surface of the substrate and then print a metal wiring. However, in this case, there is a problem in that the thermal contraction rate of the organic adhesive layer is high, causing cracks and deformation in the printed circuit wiring during the firing process.

Another method is to use an adhesive strengthening film having a high glass transition temperature (Tg) and having a special surface morphology. However, in this case, since the adhesive reinforcement film is used on the entire surface of the substrate, the thickness and price of the substrate are increased, and the substrate is bent due to the difference in the coefficient of thermal expansion between the adhesive reinforcement film and the substrate.

In order to solve the problems of the prior art as described above, an object of the present invention is to provide a circuit board having a multi-layer metal wiring that can improve the adhesion between the metal wiring and the substrate and a manufacturing method thereof.

According to one embodiment of the present invention for achieving the above object, a circuit board having a metal wiring having a multilayer structure includes a substrate; A first metal interconnection layer formed on the substrate, the first metal interconnection layer having a first metal particle capped with a polymer material, and a second metal particle formed on the first metal interconnection layer and whose surface is capped with a monomolecular material; 2 metal wiring layer.

In this case, the polymer material may be any one selected from the group consisting of polyvinyl compounds, celluloses, acrylic polymers and copolymer resins, and the first metal particles and the second metal particles may be the same metal. The first and second metal particles may include gold (Au), platinum (Pt), silver (Ag), copper (Cu), palladium (Pb), zinc (Zn), tin (Sn), lead (P), It may be at least one selected from the group consisting of indium (In), aluminum (Al), nickel (Ni) and alloys thereof. In addition, the substrate may be a printed circuit board (PCB) or a flexible printed circuit board (FPCB).

On the other hand, a method of manufacturing a metal wiring of a multi-layer structure according to an embodiment of the present invention, preparing a substrate; Forming a first metal wiring layer on the substrate with a first conductive ink containing first metal particles having a surface capped with a polymer material; And forming a second metal wiring layer on the first metal wiring layer using a second conductive ink containing second metal particles having a surface capped with a monomolecular material.

At this time, before forming the second metal wiring layer, drying the first metal wiring layer; And firing the dried first metal wiring layer. The method may further include, after the forming of the second metal wiring layer, drying the second metal wiring layer; And firing the second metal wiring layer.

The method may further include drying the first metal wiring layer before forming the second metal wiring layer, and after forming the second metal wiring layer, drying the second metal wiring layer; And firing the first and second metal wiring layers.

In addition, the firing step is to bake at 200 ℃ for 1 hour, the polymer material may be any one selected from the group consisting of polyvinyl compound, cellulose, acrylic polymer and copolymer resin, the first metal particles and The second metal particles may be the same metal, and the first and second metal particles may include gold (Au), platinum (Pt), silver (Ag), copper (Cu), palladium (Pb), and zinc. (Zn), tin (Sn), lead (P), indium (In), aluminum (Al), nickel (Ni) and one or more selected from the group consisting of alloys thereof. In addition, the substrate may be a printed circuit board (PCB) or a flexible printed circuit board (FPCB).

According to the circuit board having the multi-layered metal wiring of the present invention and a method for manufacturing the same, the adhesive force between the metal wiring and the substrate is maintained while maintaining the electrical conductivity of the metal wiring by using a metal wiring layer including metal particles capped with a polymer material. Can improve. Further, according to the circuit board having the multi-layered metal wiring of the present invention and the manufacturing method thereof, highly reliable metal wiring can be formed by excellent electrical conductivity and adhesion.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. In addition, it should be considered that elements of the drawings attached to the present specification may be enlarged or reduced for convenience of description.

A circuit board having a metal wiring having a multilayer structure and a method of manufacturing the same according to an embodiment of the present invention will be described in more detail.

1 is a block diagram showing a circuit board having a metal wiring of a multilayer structure according to an embodiment of the present invention. As shown in FIG. 1, a circuit board having a metal wiring having a multilayer structure according to the present invention may be formed on a substrate 100, a first metal wiring layer 110 formed on the substrate 100, and a first metal wiring layer 110. It includes a second metal wiring layer 120 formed.

The substrate 100 may be a printed circuit board (PCB) or a flexible printed circuit board (FPCB) such as glass, PET film, polycarbonate, or the like, and in the case of a flexible printed circuit board, a polyimide substrate may be used. . However, the present invention is not limited thereto, and any insulating substrate that can withstand thermal curing by firing may be used without limitation.

The first metal wiring layer 110 may be formed of first metal particles 111 having a surface capped with a polymer material, and the first metal wiring layer 110 may be improved in adhesion with the substrate 100 by the polymer material. . The polymer material may be any one selected from polyvinyl compound, cellulose, acrylic polymer, and copolymer resin, and the polyvinyl compound resin may be polyvinylpyrrolidone (PVP), polyvinyl butyral (PVB), or polyvinyl. Alcohol (PVA) and the like, and the copolymer resin may be vinylpyrrolidone / vinylacetate (PVP / VA).

That is, the first metal particles 111 have a form in which a polymer material is adsorbed on the surface and surrounded. At this time, the mechanism of adsorption of the polymer material on the surface of the metal particles may include covalent bonds, hydrogen bonds, or van der Waals interactions. Adsorption can be achieved by electrostatic bonding with the particle colloidal surface. However, the adsorption mechanism is not limited thereto, and the polymer material may be absorbed and fixed by any mechanism on the surface of the nano metal particles.

In addition, the content of the polymer substance is preferably in the range of 1 to 30% by weight of the total weight of the conductive ink. That is, when the content of the polymer material is 1% by weight or less, matching property with the second metal wiring layer may decrease. In addition, when the content of the polymer material is 30% by weight or more, a problem may occur in that electrical conductivity of the metal wiring is lowered by the polymer material. In addition, the particle diameter of the first metal particles 111 is preferably 20 to 50 nm.

The second metal wiring layer 120 is formed of second metal particles 121 whose surface is capped with a monomolecular material, and the monomolecular material is formed of amine, fatty acid, thiol, or the like. As long as it has affinity for the organic solvent, it can be used without limitation. In addition, the particle diameter of the second metal particles 121 is preferably 10 nm or less.

The first and second metal particles 111 and 121 are not particularly limited as long as they are conductive materials, but are not limited to gold (Au), platinum (Pt), silver (Ag), copper (Cu), palladium (Pb), and zinc ( Zn), tin (Sn), lead (P), indium (In), aluminum (Al), nickel (Ni) and one or more kinds of metal particles selected from the group consisting of alloys thereof may be used. In view of the matching properties of the two metal wiring layers 110 and 120, the metal particles are preferably homogeneous.

Next, a method of manufacturing a circuit board having a metal wiring having a multilayer structure shown in FIG. 1 will be described. 2A to 2C are cross-sectional views illustrating a process of manufacturing a circuit board having a metal wiring having a multilayer structure according to an embodiment of the present invention.

First, as shown in FIG. 2A, a substrate 100 for forming metal wirings is prepared. Here, the substrate 100 may be a printed circuit board (PCB) or a flexible printed circuit board (FPCB) such as glass, PET film, polycarbonate, and the like, and in the case of a flexible printed circuit board, a polyimide substrate may be used. However, the present invention is not limited thereto, and any insulating substrate that can withstand thermal curing by firing may be used without limitation.

When the substrate 100 is prepared, as shown in FIG. 2B, the substrate 100 may be formed on the surface of the substrate 100 using the first conductive ink 112 containing the first metal particles 111 capped with a polymer material. 1 metal wiring layer 110 is formed. In this case, the first metal wiring layer 110 is formed by discharging the first conductive ink 112 including the first metal particles 111 onto the surface of the substrate 100 to print. Thereafter, the discharged first conductive ink 112 is dried to form the first metal wiring layer 110.

The first conductive ink 112 is formed of first metal particles 111 in which a polymer material is capped in an organic solvent. In this case, as the organic solvent, alcohols including water and ethanol, isopropanol, isobutanol such as isobutanol, and the like may be used, but are not limited thereto. The polymer material may be any one selected from polyvinyl compound, cellulose, acrylic polymer, and copolymer resin, and the polyvinyl compound resin may be polyvinylpyrrolidone (PVP), polyvinyl butyral (PVB), or polyvinyl. Alcohol (PVA) and the like, and the copolymer resin may be vinylpyrrolidone / vinylacetate (PVP / VA).

In addition, the content of the polymer substance is preferably in the range of 1 to 30% by weight of the total weight of the conductive ink. That is, when the content of the polymer material is 1% by weight or less, the matching property with the second metal wiring layer may be lowered. When the content of the polymer material is 30% by weight or more, the electrical conductivity of the metal wiring by the polymer material is reduced. May cause a problem of deterioration.

In addition, the surface treatment may be performed on the substrate 100 to improve the adhesion between the first conductive ink 112 and the substrate 100.

When the first metal wiring layer 110 is formed, as shown in FIG. 2C, the second conductive ink containing the second metal particles 121 having the surface capped with a single molecule on the first metal wiring layer 110 ( 122 is discharged, and the discharged second conductive ink 122 is dried to form the second metal wiring layer 120.

Here, the second conductive ink 122 may be a non-aqueous ink, and the second conductive ink 122 may include organic solvents such as amines, fatty acids, and thiols, and second metal particles 121 capped with single molecules. Is done. The monomolecular substance can be used without limitation as long as it has affinity for organic solvents such as amine, fatty acid, thiol and the like.

Thereafter, the formed first and second metal wiring layers 110 and 120 are heat-treated and baked at 200 ° C. for 1 hour to form a circuit board having a metal wiring having a final multilayer structure. At this time, the firing of the first and second metal wiring layers 110 and 120 may be performed at the same time after printing the different types of metal wiring, respectively, or may be sequentially printed and fired. However, it is preferable to simultaneously fire the first and second metal wiring layers in order to match the metal wiring and form uniform wiring.

As described above, in the circuit board having the metallization layer according to the present invention, the polymer material capping the first metal particles 111 is bonded to the substrate made of resin during the firing process, thereby adhering to the substrate 100. This is improved. In this case, the first metal particles 111 constituting the first metal wiring layer 110 can maintain excellent matching property and electrical conductivity with the second metal wiring layer 120.

2B and 2C, the first and second conductive inks 112 and 122 may be printed on the substrate 100 by screen printing, inkjet printing, or the like. In this case, the metal wiring layer may be selectively formed on the entire surface of the substrate or a portion where the wiring pattern is to be formed.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Example 1

Using an ink containing copper capped with PVP, a circuit pattern was formed on a polyimide substrate not subjected to a separate surface treatment, followed by drying to form a first metal wiring layer. The metal wiring layer thus formed was calcined under a reducing atmosphere at 200 ° C. for 1 hour to form a metal wiring layer. At this time, the specific resistance was 5.3x10-6Ω㎝, and the adhesive force was measured by using a crosshatch test. As a result, it was confirmed that a metal wiring having excellent specific resistance value and adhesive strength was formed at 100/100.

Example 2

Using the ink containing copper capped with PVP as the first conductive ink, a circuit pattern was formed on a polyimide substrate not subjected to a separate surface treatment, followed by drying to form a first metal wiring layer. Then, using the ink containing copper capped with oleic acid as the second conductive ink, a circuit pattern was formed on the first metal wiring layer and dried to form a second metal wiring layer. The metal wiring layer thus formed was calcined under a reducing atmosphere at 200 ° C. for 1 hour to form a metal wiring layer. At this time, the specific resistance was 6.6x10-6Ω㎝, and as a result of measuring the adhesive force using the crosshatch test, it was confirmed that the metal wiring having excellent specific resistance value and adhesive strength was formed to 100/100.

Comparative Example

Using an ink containing copper capped with oleic acid, a circuit pattern was formed on a polyimide substrate not subjected to a separate surface treatment, followed by drying to form a first metal wiring layer. The metal wiring layer thus formed was calcined under a reducing atmosphere at 200 ° C. for 1 hour to form a metal wiring layer. At this time, the specific resistance was 4.5x10-6Ω㎝, and as a result of measuring the adhesive force by using the crosshatch test, it was confirmed that all metal wires were peeled off at 0/100 so that the metal wires did not have adhesive force.

Circuit board having a metal wiring according to the present invention through Examples 1 and 2 and Comparative Example to form a metal wiring by using a conductive ink containing a metal particle capped with a polymer material to excellent adhesion between the metal wiring and the substrate It can be seen that.

Therefore, the present invention can secure the adhesion to the substrate by forming a metal wiring by using the first conductive ink containing the metal particles capped with a polymer material. In addition, since the first conductive ink contains metal particles, it is possible to form a metal wiring having excellent electrical conductivity without cracking because of excellent matching with metal wiring formed from the second conductive ink. In addition, by using a heterogeneous conductive ink, a metal wiring having excellent adhesion between the substrate and the metal wiring can be formed without a separate surface treatment.

The present invention is not limited to the above-described embodiment and the accompanying drawings, but is intended to be limited by the appended claims, and various forms of substitution, modification, and within the scope not departing from the technical spirit of the present invention described in the claims. It will be apparent to those skilled in the art that changes are possible.

1 is a block diagram showing a circuit board having a metal wiring of a multilayer structure according to an embodiment of the present invention.

2A to 2C are cross-sectional views illustrating a process of manufacturing a circuit board having a metal wiring having a multilayer structure according to an embodiment of the present invention.

<Description of Drawing Major Symbols>

100. Substrate 110. First metal wiring layer

111. First Metal Particles 112. First Conductive Ink

120. Second metal wiring layer 121. Second metal particles

122. Second conductive ink

Claims (14)

Board; A first metal wiring layer formed on the substrate and having a first metal particle having a surface capped with a polymer material; And And a second metal wiring layer formed on the first metal wiring layer, the second metal wiring layer having a second metal particle whose surface is capped with a monomolecular material. The method of claim 1, The polymer material is a circuit board having a multi-layer metal wiring, characterized in that any one selected from the group consisting of polyvinyl compound, cellulose, acrylic polymer and copolymer resin. The method of claim 1, And the first metal particles and the second metal particles are homogeneous metals. The method of claim 1, The first and second metal particles are gold (Au), platinum (Pt), silver (Ag), copper (Cu), palladium (Pb), zinc (Zn), tin (Sn), lead (P), indium (In), aluminum (Al), nickel (Ni) and a circuit board having a metal layer structure having a multilayer structure, characterized in that at least one selected from the group consisting of these alloys. The method of claim 1, And said substrate is a printed circuit board (PCB) or a flexible printed circuit board (FPCB). Preparing a substrate; Forming a first metal wiring layer on the substrate with a first conductive ink containing first metal particles having a surface capped with a polymer material; And Forming a second metal wiring layer with a second conductive ink containing second metal particles having a surface capped with a monomolecular material on the first metal wiring layer; . The method of claim 6, Drying the first metal wiring layer before forming the second metal wiring layer; And Firing the dried first metal wiring layer; the method of manufacturing a circuit board having metal wiring of a multilayer structure, further comprising: a. The method of claim 7, wherein After forming the second metal wiring layer, drying the second metal wiring layer; And Firing the second metal wiring layer; the method of manufacturing a circuit board having metal wiring of a multilayer structure, further comprising: a. The method of claim 6, Before forming the second metal wiring layer, further comprising drying the first metal wiring layer, and after forming the second metal wiring layer, drying the second metal wiring layer; And firing the first and the second metal wiring layers. The method according to any one of claims 7 to 9, The firing step is a circuit board manufacturing method having a metal wiring of a multi-layer structure, characterized in that firing at 200 ℃ for 1 hour. The method of claim 6, The polymer material is a circuit board manufacturing method having a multi-layer metal wiring, characterized in that any one selected from the group consisting of polyvinyl compound, cellulose, acrylic polymer and copolymer resin. The method of claim 6, The first metal particle and the second metal particle is a circuit board manufacturing method having a metal wiring of a multi-layer structure, characterized in that the same metal. The method of claim 6, The first and second metal particles are gold (Au), platinum (Pt), silver (Ag), copper (Cu), palladium (Pb), zinc (Zn), tin (Sn), lead (P), indium (In), aluminum (Al), nickel (Ni), and a circuit board manufacturing method having a metal wiring having a multilayer structure, characterized in that at least one selected from the group consisting of these alloys. The method of claim 6, Wherein the substrate is a printed circuit board (PCB) or a flexible printed circuit board (FPCB) characterized in that the circuit board manufacturing method having a multi-layer metal wiring, characterized in that.

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