KR101189132B1 - Flexible circuit clad laminate, printed circuit board using it, and method of manufacturing the same - Google Patents

Abstract

PURPOSE: A flexible circuit copper clad laminate, a printed circuit board using the same, and a manufacturing method thereof are provided to obtain high physical property by including a tiecoat layer containing Ni, Mo, and Nb with a preset ratio. CONSTITUTION: A preprocessed polymer film(1) is provided. A tiecoat layer(2) is formed on the polymer film. The thickness of the tiecoat layer is 5 to 35 nm. A copper seed layer(3a) is formed on the tiecoat layer. The thickness of the copper seed layer is 20 to 100 nm. A copper coating layer(3b) is formed on the copper seed layer.

Description

Flexible circuit clad laminate, printed circuit board using it, and method of manufacturing the same

The present invention relates to a flexible circuit copper clad laminate, a printed circuit board using the same, and a method of manufacturing the same. It is about.

Printed circuit board (PCB) is a representation of the electrical wiring to connect the various parts according to the circuit design according to the circuit design and serves to connect or support the various components. In particular, with the development of electronic devices such as notebook computers, mobile phones, PDAs, small video cameras and electronic organizers, the demand for printed circuit boards has increased. Furthermore, the electronic devices are becoming smaller and lighter, with the emphasis on portability. Therefore, printed circuit boards are becoming more integrated, smaller, and lighter.

The printed circuit board may be a multi-flexible substrate similar to a rigid printed circuit board, a flexible printed circuit board, a rigid-flexible printed circuit board, a rigid-flexible printed circuit board, and a rigid-flexible printed circuit board. It is divided into a printed circuit board. In particular, flexible circuit clad laminate (FCCL), a raw material for flexible printed circuit boards, is used in digital home appliances such as mobile phones, digital camcorders, notebooks, and LCD monitors. Demand is growing rapidly.

The flexible circuit copper clad laminate is a laminate of a polymer film layer and a metal conductive layer, and is characterized by having flexibility. Flexible circuit copper eccentric red plate is especially used for electronic devices or material parts of electronic devices that require flexibility and flexibility, and contributes to miniaturization and light weight of electronic devices.

Conventional flexible circuit copper foil laminates related to this technology are largely divided into a method of applying a polyimide resin to the copper foil and a method of depositing copper on the polymer film. In particular, the copper deposition method can form a very thin copper film.

A flexible flexible copper clad laminate of a deposition method is prepared by forming a tiecoat layer on a polymer film by sputtering, and then electroplating copper while continuously passing it through a copper electrolytic plating bath.

The fabricated flexible circuit copper clad laminate has a semiconductor chip or an electric element mounted on the circuit after circuit formation, and is used in a miniaturized, multi-pinned, narrow pitch of a driver IC. . Accordingly, there is a need for a flexible circuit copper foil laminate having excellent physical properties such as etching properties, peel strength, and thin film density characteristics.

However, the existing flexible circuit copper foil laminate mainly using NiCr alloy, NiMoV alloy or NiMoTi alloy as a tie coat layer does not meet this requirement.

The present invention has been made in view of the above-described prior art, and an object thereof is to provide a flexible circuit copper foil laminate having excellent physical properties such as etching property, peel strength, thin film density characteristics, and the like.

A flexible circuit copper clad laminate according to the present invention for achieving the above object, a polymer film, a tiecoat layer formed on at least one side of the polymer film and a copper (Cu) layer formed on the tiecoat layer In the flexible circuit copper clad laminate comprising a, the tie coat layer contains 2.0wt% to 9.5wt% niobium (Nb), 6.0wt% to 13.5wt% molybdenum (Mo) and the balance nickel (Ni) Made of alloy.

Preferably, the tie coat layer may have a density of about 6.70 × 10 ²² atoms / cm ³ or more.

Preferably, the corrosion current density of the tie coat layer may be 0.6 mA / cm ^{2 or} more.

Preferably, the thickness of the tie coat layer may be 5nm to 35nm.

Preferably, the polymer film may be made of at least one of a thermosetting resin, a thermoplastic resin, a polyester resin, a polyimide resin, a condensate, or a mixture of at least two or more thereof selected from them.

Preferably, the polymer film may be a polyimide resin.

Advantageously, said copper layer comprises: a copper seed layer formed on said tiecoat layer; And a copper film layer formed on the copper seed layer.

Preferably, the thickness of the copper seed layer may be 20nm to 100nm.

Preferably, the copper coating layer may have a thickness of 5 μm to 15 μm.

On the other hand, the flexible circuit board according to the present invention for achieving the above object is provided with a wiring pattern formed on the copper layer of the flexible circuit copper clad laminate.

Method for producing a flexible circuit copper clad laminate according to the present invention for achieving the above object, (a) preparing a polymer film; (b) an alloy containing 2.0 wt% to 9.5 wt% of niobium (Nb), 6.0 wt% to 13.5 wt% of molybdenum (Mo), and the balance of nickel (Ni) on at least one side of the polymer film; Forming a tiecoat layer; And (c) forming a copper layer on the tiecoat layer; It includes.

Preferably, the step (a) may include the step of removing the contaminants on the surface and modifying the surface by plasma treatment of the polymer film.

Preferably, step (b) may be a step of forming a tie coat layer on the polymer film by using a sputtering method.

Preferably, step (c) may be a step of forming a copper coating layer on the copper seed layer after forming a copper seed layer on the tie coat layer.

Preferably, the copper seed layer may be formed by sputtering, and the copper coating layer may be formed by electroplating.

On the other hand, the method of manufacturing a flexible circuit board according to the present invention for achieving the above object, the manufacturing step of the flexible circuit copper clad laminate; And forming a wiring pattern on the copper layer of the flexible circuit copper clad laminate.

According to the present invention, the alloy forming the tie coat layer formed on the polymer film is to include nickel (Ni), molybdenum (Mo) and niobium (Nb), ductility by controlling the content ratio of the metal contained in the alloy The effect of improving the physical property of a circuit copper foil laminated board is acquired.

The following drawings, which are attached to this specification, illustrate exemplary embodiments of the present invention, and together with the detailed description of the present invention, serve to further understand the technical spirit of the present invention. It should not be construed as limited to.
1 is a cross-sectional view of a flexible circuit copper laminate according to the present invention.
2 is a flowchart illustrating a method of manufacturing a flexible circuit copper clad laminate according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the present specification and claims should not be construed as being limited to the ordinary or dictionary meanings, and the inventors should properly explain the concept of terms in order to explain their own invention in the best way. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

1 and 2, a flexible circuit copper foil laminate and a method of manufacturing the same according to the present invention will be described.

1 is a cross-sectional view of a flexible circuit copper foil laminate according to the present invention, Figure 2 is a flow chart showing a manufacturing method of a flexible circuit copper foil laminate according to the present invention.

1 and 2, a flexible circuit copper foil laminate according to the present invention is formed by sequentially stacking a polymer film 1, a tie coat layer 2, and a copper layer 3.

The polymer film 1 is a film of a single layer or a composite layer made of at least one of a thermosetting resin, a thermoplastic resin, a polyester resin, a polyimide resin, a condensation polymer or at least two or more mixtures thereof selected from them. The polymer film 1 may be made of filler (or without filler), woven glass, non woven glass and / or other fibrous material.

The thermosetting resins include phenol resins, phenolaldehyde resins, furan resins, aminoplast resins, alkyd resins, allyl resins, epoxy resins, epoxy prepregs, polyurethane resins, thermosetting polyester resins, silicone resins, and the like. This can be used. As the thermoplastic resin, polyethylene, polypropylene, ethylene / vinyl copolymer, ethylene acrylic acid copolymer, or the like may be used. As the polyester resin, those made of divalent aliphatic and aromatic carboxylic acids and diols or triols may be used. The polyimide resins are particularly useful, which are obtained through the reaction of tetrabasic acid dianhydride with an aromatic diamine to yield a polyamic acid which is then converted to high molecular weight linear polyimide by heat or catalyst. Can be. The condensation polymer may be polyamide, polyether imide, polysulfone, polyethersulfone, polybenzazole, aromatic polysulfone and the like. The polymer film 1 is subjected to a pretreatment process before depositing the tie coat layer 2. That is, the polymer film 1 is plasma treated prior to the formation of the tie coat layer 2 to remove contaminants on the surface and to modify the surface.

The tie coat layer 2 is formed on at least one of both surfaces of the polymer film 1, and is made of an alloy containing nickel (Ni) as a main component. The tie coat layer 2 may be deposited on the polymer film 1 by a sputtering method, which is a kind of dry plating method, and is preferably formed to a thickness of about 5 nm to 35 nm. When the thickness of the tie coat layer 2 is less than 5 nm, there is a concern that the peeling strength is lowered at the time of etching for forming the wiring pattern, and when the thickness exceeds 35 nm, the etching process is not easy.

The alloy forming the tie coat layer 2 further includes molybdenum (Mo) and niobium (Nb) in addition to nickel. The content of molybdenum constituting the alloy is preferably about 6.0wt% to 13.5wt% relative to the total weight of the alloy. When the content of molybdenum is less than 6.0wt%, there is a problem in that the etching property is poor, that is, the corrosion current density value is low. On the contrary, when the content of molybdenum exceeds 13.5 wt%, the peel strength of the flexible circuit copper clad laminate is inferior. The content of niobium present in the alloy is preferably about 2.0 wt% to 9.5 wt%. If the content of niobium is less than 2wt%, there is a problem that the peel strength of the flexible circuit copper clad laminate falls. When the peel strength falls below a certain value (high temperature: less than 0.4kgf / cm, room temperature: less than 0.6kgf / cm), peeling phenomenon due to external temperature change in a flexible circuit copper clad laminate to which narrow pitch is applied (polymer film— There is a problem that occurs between the tie coat). On the contrary, when the content of niobium exceeds 9.5 wt%, there is a problem that the etching property is inferior, that is, the corrosion current density value is low (less than 0.6 mA / cm ² ). When the corrosion current density is measured below 0.6 mA / cm ² , a residue may remain during etching, and thus, a problem of a short circuit between wires may occur due to ion migration. Therefore, the alloy is most preferably made of 2.0wt% to 9.5wt% of niobium (Nb), 6.0wt% to 13.5wt% of molybdenum (Mo) and the balance nickel (77wt% to 92wt%).

On the other hand, in depositing the tie coat layer 2 on the polymer film 1, it is preferable to maintain the density value of the alloy of about 6.70 6.10 ²² atoms / cm ³ or more. When the density value of the alloy is less than 6.70ⅹ10 ²² atoms / cm ³ , there is a problem that the peel strength between the polymer film 1 and the tie coat layer 2 becomes low at high temperature and / or room temperature. The density of the alloy can be adjusted by varying the power of the sputter.

The copper layer 3 is formed on top of the tie coat layer 2 and includes a copper seed layer 3a and a copper coating layer 3b. The copper seed layer 3a is a layer formed by sputtering on the tie coat layer 2 and is formed to a thickness of approximately 10 nm to 100 nm.

The coating layer 3b is a copper layer formed on the copper seed layer 3a by an electroplating method, and is preferably formed in a thickness of about 5 μm to 15 μm, more preferably 8 μm to 8.5 μm. Can be formed.

As described above, in the flexible circuit copper clad laminate according to the present invention, a step (S1) of preparing a polymer film 1 which has been subjected to a pretreatment process, a step of forming a tie coat layer (S2), and a copper seed layer 3a And a step (S4) of forming a copper film layer (3b). The copper clad laminate has excellent physical properties by having a tie coat layer containing nickel, molybdenum and niobium in a certain content range.

On the other hand, by etching a copper layer of the flexible circuit copper clad laminate manufactured through the above process using a known method such as photoetching, a desired wiring pattern can be formed, thereby obtaining a printed circuit board (PCB).

Hereinafter, the pretreatment and film formation conditions (Table 1), the evaluation method of physical properties and the experimental example (Table 2) for manufacturing the flexible circuit copper clad laminate will be described.

<Property evaluation method>

-Peel strength: Peel strength was measured according to IPC-TM-650, NUMBER2.4.9. After 8 measurements using the UTM instrument, the average of the values excluding the maximum and minimum values is obtained. The lead width was 1mm and the required angle was 90 degrees. The peeling strength was evaluated after leaving the film base material with a 1 mm lead as an indicator of heat resistance and leaving it in an oven at 150 ° C. for 168 hours.

Thin Film Density: A sample 7mm × 7mm was prepared and the density of the tiecoat was measured using a Rutherford Backscattering Spectrometer (RBS) analyzer (density = atoms / cm 3)

Etchability: A polyimide (PI) / tiecoat layer (20 nm) / copper seed layer (60 nm) was deposited and sampled in a size of 30 mm × 30 mm and then dipped into an electrochemical test solution to dilute the Potentio-Stat. The etching tendency was confirmed by measuring the value of corrosion current density. (Etching solution condition: Base 5ml + DI water 1.5L / Base solution: FeCl ₃ ~ 6H ₂ O: 76.2g + DI water 152.4g Specific gravity 1.3)

Comparing the experimental results shown in Example 7 and Comparative Example 2 and Comparative Example 5, and comparing the experimental results shown in Example 11 and Comparative Example 6, the niobium content of the tie coat layer (2) to 2.0wt% to When the 9.5wt% range is maintained, it can be seen that the physical properties (peel strength and etching property) of the flexible circuit copper clad laminate are excellent. In addition, comparing the experimental results shown in Example 8 and Comparative Example 3, and comparing the experimental results shown in Example 6 and Comparative Example 4, the molybdenum content of the tie coat layer (2) is 6.0wt% to 13.5wt% In the case of maintaining the range, it can be seen that the physical properties (peel strength and etching property) of the flexible circuit copper clad laminate are excellent. That is, the corrosion current density of the flexible circuit copper clad laminate measured in the above range is maintained at 0.6 mA / cm ² or more, the high temperature peel strength and room temperature peel strength is maintained at 0.40kgf / cm and 0.6kgf / cm or more, respectively.

On the other hand, when comparing the Examples and Comparative Examples 7 and 8, the density of the tie coat layer (2) should be maintained at 6.70ⅹ10 ²² atom / cm ³ or more, the peel strength at a high temperature and room temperature above a certain level (high temperature: 0.4kgf / cm, room temperature: 0.6kgf / cm or more) can be seen that.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not to be limited to the details thereof and that various changes and modifications will be apparent to those skilled in the art. And various modifications and variations are possible within the scope of the appended claims.

1: polymer film 2: tie coat layer
3: copper layer 3a: copper seed layer
3b: copper film layer

Claims (16)

In the flexible circuit copper clad laminate comprising a polymer film, a tiecoat layer formed on at least one side of the polymer film and a copper (Cu) layer formed on the tiecoat layer,
The tie coat layer is composed of an alloy containing 2.0 wt% to 9.5 wt% of niobium (Nb), 6.0 wt% to 13.5 wt% of molybdenum (Mo), and a balance of nickel (Ni). Laminates. The method of claim 1,
The tie coat layer has a density of 6.70ⅹ10 ²² atom / cm ³ or more, flexible circuit copper clad laminate. The method of claim 1,
Corrosion current density of the tie coat layer is a flexible circuit copper clad laminate, characterized in that more than 0.6mA / cm ² . The method of claim 2,
The thickness of the tie coat layer is a flexible circuit copper clad laminate, characterized in that 5nm to 35nm. The method of claim 1,
Wherein the polymer film is made of at least one of a thermosetting resin, a thermoplastic resin, a polyester resin, a polyimide resin, a condensation polymer, or a mixture of at least two or more thereof. The method of claim 5,
The polymer film is a flexible circuit copper clad laminate, characterized in that the polyimide resin. The method of claim 1,
The copper layer,
A copper seed layer formed on the tiecoat layer; And
And a copper film layer formed on the copper seed layer. The method of claim 7, wherein
The copper seed layer is a flexible circuit copper clad laminate, characterized in that the thickness of 20nm to 100nm. 9. The method of claim 8,
The thickness of the copper film layer is a flexible circuit copper clad laminate, characterized in that 5㎛ to 15㎛. The printed circuit board provided with the wiring pattern formed in the copper layer of the flexible circuit copper clad laminated board of any one of Claims 1-9. (a) preparing a polymer film;
(b) a tie composed of an alloy containing 2.0 wt% to 9.5 wt% of niobium (Nb), 6.0 wt to 13.5 wt% of molybdenum (Mo), and the balance of nickel (Ni) on at least one side of the polymer film; Forming a coat layer; And
(c) forming a copper layer on the tiecoat layer; Method for producing a flexible circuit copper clad laminate comprising a. The method of claim 11,
The step (a), the method of manufacturing a flexible circuit copper clad laminate comprising the step of removing the contaminants on the surface and modifying the surface by plasma treatment of the polymer film. The method of claim 11,
The step (b) is a method for manufacturing a flexible circuit copper clad laminate, characterized in that the step of depositing a tie coat layer on the polymer film using a sputtering method. The method of claim 11,
The step (c) is a step of forming a copper seed layer on the copper seed layer after forming a copper seed layer on the tie coat layer, the method of manufacturing a flexible circuit copper clad laminate. 15. The method of claim 14,
The copper seed layer is deposited on the tiecoat layer by sputtering,
And said copper film layer is plated on said copper seed layer by electroplating. Manufacturing a flexible circuit copper clad laminate according to any one of claims 11 to 15; And
Forming a wiring pattern on the copper layer of the flexible circuit copper clad laminate.

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