KR20160089797A - Flexible circuit clad laminate, printed circuit board using it, and method of manufacturing the same - Google Patents

Abstract

According to an embodiment of the present invention, a flexible circuit clad laminate comprises: a resin layer; an adhesion reinforcing layer formed on at least one surface of the resin layer by a pre-treatment work containing silane; a tiecoat layer formed on the adhesion reinforcing layer containing the silane; and a copper layer formed on the tiecoat layer.

Description

TECHNICAL FIELD [0001] The present invention relates to a flexible circuit clad laminate, a printed circuit board using the same, and a method of manufacturing the same.

BACKGROUND OF THE INVENTION 1. Field of the Invention 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. More specifically, A flexible circuit copper-clad laminate, a printed circuit board using the same, and a manufacturing method thereof.

A printed circuit board (PCB) is a wiring diagram that expresses the electrical wiring to connect various components according to the circuit design. It serves to connect or support various components. In particular, the demand for printed circuit boards has increased with the development of electronic devices such as notebook computers, mobile phones, PDAs, compact video cameras, and electronic notebooks. Furthermore, the above electronic devices are becoming increasingly smaller and lighter in weight as portability is emphasized. Therefore, printed circuit boards are being further integrated, miniaturized, and lightweight.

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

The flexible circuit copper-clad laminate is a laminate of a polymer film layer and a metal conductive layer, and is flexible. Flexible circuit pendant side plates are used in parts of electronic equipment or electronic equipment that require flexibility and flexibility, contributing to miniaturization and weight reduction of electronic equipment.

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

The flexible circuit copper-clad laminate of the deposition type is manufactured by forming a tie coat layer on a polymer film by a sputtering method and then electrolytically plating copper while continuously passing the tiecoat layer through a copper electrolytic plating bath.

In the fabricated flexible circuit copper-clad laminate, a semiconductor chip, an electric element, or the like is mounted on a circuit after the circuit is formed, and a miniaturization, a multi-pin, and a narrow pitch of a driver IC are rapidly proceeding . Therefore, there is a demand for a flexible circuit copper-clad laminate having excellent physical properties such as an etching property, a peel strength, and a thin film density property.

Among these properties, a method of performing dry pretreatment such as plasma pretreatment on the surface of the resin layer in order to improve the peel strength, in particular, the peel strength between the resin layer made of a polymer film and the tie coat layer has been used. There is a problem that it is difficult to obtain satisfactory peel strength (in particular, peel strength at high temperature).

Therefore, there is a need for development of a technique capable of remarkably improving the high-temperature peeling strength between the resin layer and the tie coat layer by applying a pretreatment other than the conventional pretreatment method.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a technique capable of remarkably improving high-temperature peeling strength between a resin layer and a tie coat layer.

It is to be understood, however, that the technical scope of the present invention is not limited to the above-mentioned problems, and other technical subjects not mentioned above can be understood by those skilled in the art from the description of the invention described below.

The inventors of the present invention have conducted studies to develop a technique capable of remarkably improving the high temperature peeling strength between the resin layer and the tie coat layer, and as a result, they have found that by carrying out wet pretreatment using silane, (The peeling strength between the resin layer and the tie coat layer) was remarkably improved by forming the adhesive strength-enhancing layer for the flexible circuit.

Further, the inventors of the present invention have continued to investigate, by forming the adhesion strength-enhancing layer containing silane, by controlling the thickness of the adhesion strengthening layer containing silane and the concentration of silane within a certain range, So as to produce a flexible circuit copper-clad laminate.

The flexible circuit copper-clad laminate according to one embodiment of the present invention developed in accordance with the above-described research comprises a resin layer; An adhesion strengthening layer formed on at least one surface of the resin layer by pretreatment and containing silane; A tie coat layer formed on the adhesion strengthening layer containing the silane; And a copper layer formed on the tie coat layer.

The silane may have a composition containing 25% or less of Si, 40% or more of C, 3% or more of O, and 5% or less of N (% means atomic%).

As the solvent for the silane, isopropyl alcohol may be used.

The thickness of the adhesion strengthening layer is 3 nm to 30 nm, and the concentration of the silane contained in the material used for manufacturing the adhesion strengthening layer may be 1.0 mol% to 1.2 mol%.

The resin layer may be made of a polyimide resin.

The tie coat layer may be formed to a thickness ranging from 7 nm to 50 nm.

Wherein the copper layer comprises: a copper seed layer formed on the tie coat layer; And a copper coating layer formed on the copper seed layer.

A printed circuit board according to an embodiment of the present invention includes a wiring pattern formed on a copper layer of a flexible circuit copper clad laminate according to an embodiment of the present invention.

In addition, a method of manufacturing a flexible circuit copper clad laminate according to an embodiment of the present invention includes the steps of: (S1) forming a resin layer; (S2) wet-pretreating at least one surface of the resin layer to form an adhesion-strengthening layer containing silane; (S3) forming a tie coat layer on the adhesion enhancing layer; And (S4) forming a copper layer on the tie coat layer.

The silane may have a composition containing 25% or less of Si, 40% or more of C, 3% or more of O, and 5% or less of N (% means atomic%).

As the solvent for the silane, isopropyl alcohol may be used.

The step (S2) includes the step of controlling the thickness and the concentration so that the thickness of the adhesion strengthening layer is 3 nm to 30 nm and the concentration of the silane contained in the material used for manufacturing the adhesion strengthening layer is 1.0 mol% to 1.2 mol% . ≪ / RTI >

The step (S3) may be a step of depositing a tie coat layer on the resin layer using a sputtering method.

The step (S3) may be a step of forming the tie coat layer to a thickness ranging from 7 nm to 50 nm.

The step (S4) includes the steps of: (S41) depositing a copper seed layer on the tie coat layer by a sputtering method; And (S42) plating a copper coating layer on the copper seed layer by an electrolytic plating method.

A method of manufacturing a printed circuit board according to an embodiment of the present invention includes etching a tie coat layer and a copper layer provided on a flexible circuit copper-clad laminate produced by the method of manufacturing a flexible circuit copper-clad laminate according to an embodiment of the present invention, Thereby forming a wiring pattern.

According to an aspect of the present invention, the adhesive force between the resin layer and the tie coat layer constituting the flexible circuit copper-clad laminate is enhanced, thereby improving the peel strength at a high temperature, thereby ensuring the excellent quality of the manufactured flexible circuit copper- clad laminate .

According to another aspect of the present invention, the quality of the printed circuit board manufactured by forming the wiring pattern on the copper layer of the flexible circuit copper clad laminate by improving the quality of the flexible circuit copper clad laminate can be remarkably improved.

1 is a cross-sectional view showing a flexible circuit copper-clad laminate according to an embodiment of the present invention.
2 is a process diagram showing a method of manufacturing a flexible circuit copper-clad laminate according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concept of the term appropriately in order to describe its own invention in the best way. It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined. 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-clad laminate according to an embodiment of the present invention and a method of manufacturing the same will be described.

FIG. 1 is a cross-sectional view illustrating a flexible circuit copper-clad laminate according to an embodiment of the present invention, and FIG. 2 is a process diagram illustrating a method of manufacturing a flexible circuit copper clad laminate according to an embodiment of the present invention.

1 and 2, a flexible circuit copper-clad laminate 10 according to an embodiment of the present invention includes a resin layer 1, an adhesion enhancing layer 1a, a tie coat layer 2, and a copper layer 3, Are stacked in this order.

The resin layer (1) corresponds to a film of a single layer or a multiple layer composed 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 selected from these.

Examples of the thermosetting resin include phenol resin, phenol aldehyde resin, furan resin, aminoplast resin, alkyd resin, allyl resin, epoxy resin, epoxy prepreg, polyurethane resin, thermosetting polyester resin, Can be used. Examples of the thermoplastic resin include polyethylene, polypropylene, ethylene / vinyl copolymer, and ethylene acrylic acid copolymer. As the polyester resin, those prepared from a dihydric aliphatic and aromatic carboxylic acid and a diol or triol can be used. The polyimide resin is particularly useful because it is obtained by bringing a tetrabasic acid dianhydride into contact with an aromatic diamine to yield a polyamic acid and then converting it into a polymeric linear polyimide by heat or a catalyst . As the condensation polymer, polyamide, polyether imide, polysulfone, polyethersulfone, polybenzazole, aromatic polysulfone and the like can be used.

The adhesion strengthening layer 1a is formed on at least one surface of the resin layer 1 and is formed through a wet pretreatment process on the surface of the resin layer 1. [ That is, the polymer film constituting the resin layer (1) is subjected to a wet pretreatment step prior to the formation of the tie coat layer (2) in order to improve adhesion with the tie coat layer (2) (1) and the tie coat layer (2).

The adhesion strengthening layer 1a contains silane. In order to maximize the adhesion strengthening effect of the adhesion strengthening layer 1a, the thickness of the silane layer having a certain compositional ratio in the formation process of the layer, The concentration (mol%) can be controlled within a certain range.

That is, the thickness of the adhesive force enhancing layer 1a is preferably limited to approximately 3 nm to 30 nm, and the concentration of the silane contained in the material used for the production of the adhesive strength reinforcing layer is limited to 1.0 mol% to 1.2 mol% .

If the thickness of the silane is too small, preprocessing can not be performed sufficiently. If the thickness of the silane is too thick, the silane bond of the outermost layer is unstable and sufficient bonding strength can not be ensured. The problem of weakening may occur.

If the concentration value of the silane is too small, there is a problem that the pretreatment is not sufficient. If the concentration value is too large, the silane coagulation may occur and a weak bonding layer may be formed. Adherence may be adversely influenced and peeling strength may be lowered.

The tie coat layer 2 may be made of an alloy containing nickel (Ni) as a main component. The tie coat layer 2 may be formed on at least one of both surfaces of the pretreated resin layer 1, do.

The tie coat layer 2 may be deposited on the resin layer 1 by a sputtering method, which is a kind of dry plating method, and is preferably formed to a thickness ranging from about 7 nm to 50 nm. That is, when the thickness of the tie coat layer 2 is less than 7 nm, there is a risk of deterioration of the peel strength at the time of etching for forming the wiring pattern, and when the thickness exceeds 50 nm, the etching process becomes difficult.

The tie coat layer 2 may further contain metals such as molybdenum (Mo) and / or niobium (Nb) and / or chromium (Cr) in addition to nickel.

The copper layer 3 is formed on the tie coat layer 2 and may include 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 may be formed to a thickness of approximately 60 nm to 1000 nm.

The coating layer 3b is a copper layer formed by electrolytic plating on the copper seed layer 3a, and is preferably formed to a thickness of approximately 8 to 16 mu m, more preferably approximately 10 to 14 mu m thick As shown in FIG.

As described above, the flexible circuit copper-clad laminate 10 according to one embodiment of the present invention includes a step S1 of forming a resin layer 1 made of a polymer film, a step of forming a resin layer 1 on at least one side of the resin layer, A step S2 of forming the reinforcing layer 1a, a step S3 forming the tie coat layer 2 on the adhesion strengthening layer 1a and a step of forming the copper layer 3 on the tie coat layer ≪ / RTI >

The flexible circuit copper-clad laminate 10 has excellent physical properties by controlling the thickness of the adhesion-strengthening layer 1a and the content range of the silane contained in the material used for forming the adhesion-strengthening layer within a certain level.

On the other hand, a desired wiring pattern can be formed by etching the copper layer 3 and the tie coat layer 2 of the flexible circuit copper-clad laminate manufactured through the above process using a known method such as photoetching, A substrate (PCB) is obtained.

Hereinafter, experimental conditions and physical property evaluation methods for manufacturing the flexible circuit copper-clad laminate 10 will be described, and the properties of the flexible circuit copper-clad laminate thus manufactured will be described with reference to Tables 1 and 2.

Conditions of Applicable Substance

Composition of silane used for pretreatment: Contains not more than 25% Si, not less than 40% C, not less than 3% O and not more than 5% N based on atomic%.

Solvent for silane: IPA (isopropyl alcohol) is used.

Manufacturing conditions

Wet pretreatment was performed on the polyimide film using a silane + solvent (IPA) material, and then a tie coat and a copper seed layer were deposited using a sputtering method. Then, plating was performed on the copper seed layer by electroplating. At this time, the thickness of the silane layer formed by the pretreatment was 3 to 30 nm, the thickness of the tie coat layer was 7 to 50 nm, the thickness of the copper seed layer was 60 to 1000 nm, and the thickness of the copper plating layer was 12 탆.

On the other hand, in the case of the pretreatment using the silane-containing material, the wire bar (No. 8) was coated and dried in an oven (about 120 ° C.) for about 5 minutes.

Evaluation method of physical properties

Reflectance: The reflectance was measured in a visible light region of 330 to 750 nm in a sample of 3 cm x 3 cm.

High-temperature Peel Strength: A sample having a copper plating layer coated to a thickness of 12 μm was patterned to have a width of 1 mm and a length of 10 cm after patterning, and then the minimum and maximum peel strengths were measured after measuring the peel strength by 180 degree measurement using Instron equipment The average value of six samples was measured.

Concentration of silane: The amount of light absorbed by the material was measured using light of a specific wavelength 400 nm wavelength using spectroscopic analysis (using the K-MAC SV2100 model).

Referring to Tables 1 and 2, the silane concentration in the silane + solvent mixture used in the pretreatment is maintained in the range of approximately 1.0 mol% to 1.2 mol%, and the thickness of the silane layer is maintained in the range of approximately 3 nm to 30 nm It can be confirmed that the high-temperature peel strength is remarkably high.

In particular, in Table 1, when the results of Example 1 and Comparative Example 3 are compared, even when the thickness of the silane layer (adhesion strengthening layer) is in the range of 3 nm to 30 nm, the silane concentration in the mixture of silane + mol%, the phenomenon that the high-temperature peel strength remarkably drops occurs.

Likewise, when the results of Example 4 and Comparative Example 5 are compared, even when the thickness of the silane layer is in the range of 3 nm to 30 nm, when the concentration of the silane in the mixture of the silane + solvent exceeds 1.2 mol%, the high- A phenomenon in which the amount of water is remarkably decreased is generated. The high temperature peel strength should be 0.65 kgf / cm or more. This is because when the manufactured flexible circuit copper-clad laminate is used in the manufacture of a circuit board, it is subjected to various heat treatment process steps such as a hot press process and a reflow process If the high-temperature peeling strength is low in this process, the product may be defective.

On the other hand, in Table 2, when the results of Example 5 and Comparative Example 8 are compared, even when the concentration of the silane in the silane + solvent mixture is maintained in the range of 1.0 mol% to 1.2 mol%, the thickness of the silane layer is less than 3 nm It can be seen that the phenomenon that the high-temperature peel strength remarkably drops occurs. Similarly, when the results of Example 11 and Comparative Example 10 are compared, even when the concentration of the silane in the mixture of the silane + solvent is maintained in the range of 1.0 mol% to 1.2 mol%, when the thickness of the silane layer becomes thicker than 30 nm The phenomenon that the high-temperature peeling strength is significantly lowered occurs.

Further, in the case where water was used as a solvent (Comparative Example 4 and Comparative Example 9) and IPA was used (for example, in Examples which show almost the same conditions as Comparative Examples 4 and 9 except for the solvent used 4 and Example 6), it can be seen that the high-temperature peel strength is much better when IPA is used than when water is used as a solvent.

As described above, the flexible circuit copper-clad laminate 10 according to the embodiment of the present invention has a bonding strength between the resin layer 1 and the tie coat layer 2 through the wet pretreatment for the resin layer 1 The strengthening layer 1a is formed, and the high temperature peeling strength characteristic is remarkably improved by controlling the concentration of the silane in the silane + solvent mixture used in the pretreatment and the thickness of the formed adhesion strengthening layer 1a within a certain range.

In addition, since the physical properties of the flexible circuit copper-clad laminate 10 are improved, the quality of the printed circuit board can be improved by forming the wiring pattern on the copper layer of the copper clad laminate 10.

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: resin layer
1a: Adhesion strengthening layer
2: Tie coat layer
3: copper layer
3a: copper seed layer
3b: Copper coating layer
10: Flexible Circuit Punch Laminate (FCCL)

Claims (10)

Resin layer;
An adhesion strengthening layer formed on at least one surface of the resin layer by pretreatment and containing silane;
A tie coat layer formed on the adhesion strengthening layer containing the silane; And
And a copper layer formed on the tie coat layer,
Wherein the silane has a composition of 25% or less of Si, 40% or more of C, 3% or more of O, and 5% or less of N (% means Atomic%). The method according to claim 1,
The thickness of the adhesion enhancing layer is 3 nm to 30 nm,
Wherein the concentration of the silane is 1.0 mol% to 1.2 mol%. 3. The method according to claim 1 or 2,
The copper layer may be formed,
A copper seed layer formed on the tie coat layer; And
And a copper coating layer formed on the copper seed layer. 3. The method according to claim 1 or 2,
Wherein the solvent for the silane is isopropyl alcohol. 3. The method according to claim 1 or 2,
Wherein the resin layer is made of a polyimide resin. 3. The method according to claim 1 or 2,
The tie coat layer
Wherein the thickness of the flexible circuit copper clad laminate is in the range of 7 nm to 50 nm. A printed circuit board comprising a wiring pattern formed on a copper layer of a flexible circuit copper-clad laminate according to claim 1 or 2. (S1) a resin layer;
(S2) wet-pretreating at least one surface of the resin layer to form an adhesion-strengthening layer containing silane;
(S3) forming a tie coat layer on the adhesion enhancing layer; And
(S4) forming a copper layer on the tie coat layer;
/ RTI >
Wherein said silane has a composition of 25% or less Si, 40% or more of C, 3% or more of O, and 5% or less of N (% means atomic%). 9. The method of claim 8,
The step (S2)
And controlling the thickness and the concentration so that the thickness of the adhesion strengthening layer is 3 nm to 30 nm and the concentration of the silane is 1.0 mol% to 1.2 mol%. A method of manufacturing a printed circuit board comprising the steps of: forming a wiring pattern by etching a copper layer provided on a flexible circuit copper clad laminate produced by the method of manufacturing a flexible circuit copper clad laminate according to claim 8 or 9.

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