KR101831298B1 - Fabrication method of Flexible Flat Cable and Flexible Flat Cable thereby - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a flexible flat cable and a flexible flat cable therefor, and more particularly, to a CAM (Computer Aided Manufacturing) step of redesigning and modifying a design data cable shape to a copper- A dry film adhesion step of bringing the photosensitive dry film into close contact with the copper foil surface of the film with the copper foil circuit using heat and pressure; An exposure step of successively printing a circuit pattern using the photosensitive dry film; An etching step of completing the circuit pattern through development and etching of a film with a copper foil circuit on which a circuit pattern is formed and exfoliation of the dry film; A lamination step of laminating and laminating a film with a copper foil circuit on which a circuit pattern is completed, a cover film and a reinforcing plate; And a plating step of the laminated film, a circuit such as a straight line and a curved line can be freely implemented. Unlike a conventional flexible flat cable (FFC) in which a cable has only a linear shape, a cable can be formed in a curved form There is an effect.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of manufacturing a flexible flat cable,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a flexible flat cable (FFC) and a flexible flat cable (FFC) by the method. More specifically, the present invention relates to a flexible circuit board (FPC) The present invention relates to a method of manufacturing a flexible flat cable (FFC) which simultaneously satisfies the advantages of a cable (FFC) and a flexible flat cable (FFC).

Recently, with the development of integrated density of semiconductor integrated circuits in the field of electronic industry, development of surface mounting technology for directly mounting small chip components, and miniaturization of electronic equipment, there is a need for a printed circuit board which is easy to be embedded even in a more complicated and narrow space A flexible printed circuit board (FPC) or a flexible flat cable (FFC) has been developed in response to this demand. The flexible printed circuit board (FPC) is a freely bendable printed circuit board (PCB), and the flexible flat cable (FFC) is used to connect both sides as a thin and flat bent cable.

Such flexible printed circuit boards (FPCs) and flexible flat cables (FFCs) have been rapidly increasing in demand due to the development of electronic devices such as portable terminals, LCDs, PDPs, cameras, and printer heads.

A method of manufacturing such a flexible flat cable (FFC) and a flexible printed circuit board (FPC) is as follows.

First, flexible flat cable (FFC) is manufactured in the order of FFC laminate, plating, short inspection, external stamping, finished product inspection, shipment inspection, packaging, and shipment.

3, the FFC laminate in the process according to the manufacturing method of such a flexible flat cable (FFC) is formed by laminating the insulating film 30a / conductor 10 / And laminating the insulating film 30b / reinforcing plate by pressing the heating roll 40 to laminate them. Plating is a process of electrolytically plating the laminated product with Ni / Au. A short inspection is a process for inspecting a short of a roll-shaped product. Outside punching is a process of cutting a product that is short-checked. The finished product inspection is a process for inspecting the appearance (folding dimensions and label inspection) of the finished flexible flat cable (FFC) finished product. The shipment inspection is a process for inspecting samples of finished products. Packaging and shipment are the process of packing the finished products in boxes and supplying them to the customers.

The flexible printed circuit board (FPC) can be used in various applications such as CAM, cutting, drilling, copper plating, front face, dry film, exposure, etching, C / L bonding, heat pressing, gold plating, , Shipment inspection, packaging, and shipment.

In the process according to the manufacturing method of the flexible printed circuit board (FPC), the CAM is a process of redesigning and correcting the design data of the circuit board of the customer to an insulating film suitable for the production process. Cutting is the first step to produce a product of flexible printed circuit board (FPC), which is a process of cutting the modified copper clad laminate (CCL) according to the working size. The drill is a step of processing a guide necessary for the process and a viahole for energizing the copper clad laminate (CCL). Copper plating is a process of plating copper on the surface of a copper-clad laminate (CCL) and the inner wall of a via hole to energize the product. The front is a brush process to improve the adhesion of the dry film and remove the burr. Dry film is a process of applying dry film to a copper-plated film by using heat and pressure. Exposure is a step of irradiating ultraviolet (UV) light to form a circuit on a dry film. Etching is a process of completely forming a circuit through development, etching and peeling. C / L is a process of attaching a coverlay film to the iron or iron to protect the circuit of the folded product. The hot press is a process of completely pressing the coverlay film with the heat and pressure applied thereto. Gold plating is a process of plating the surface with gold to prevent oxidation of the product. Printing (post-finishing) is a step of processing a guide hole necessary for external shaping and the like. B.B.T is a process to detect open / short defect by applying current to the product. Outer shape processing is a process of processing the outer edges of a product by using a die press. The final inspection is a process of inspecting the surface of a single unit of product using a microscope. SMD is a process for mounting components such as connectors, LEDs, and chips on the surface of finished products. The shipment inspection is a process of final detection of defects by measuring the defects of the mounted parts and the dimensions of the products. Packing and shipment is a process of packaging the products and supplying them to each customer to prevent oxidation and hygroscopicity of the products supplied to the customers.

However, the above-described flexible flat cable (FFC) and flexible printed circuit board (FPC) have the following advantages and disadvantages.

Flexible flat cable (FFC) has about 8 simple processes. It mainly uses polyether (PET) film and polyester adhesive. It has high price competitiveness and is easy to mass-produce by roll-to-roll production method. In addition, since thermoplastic bonding is used, it is possible to store the material at room temperature. However, since it can be applied only to a linear circuit, it can not be applied to a curved circuit. In addition, since the roll-to-roll production method can not freely implement the shape of the cable, the conductor in the cable can not freely adjust the width in the longitudinal direction by the slitting line or the rolling line.

In addition, flexible printed circuit boards (FPCs) have advantages of high heat resistance because they can freely implement circuits such as straight lines and curved lines, and mainly use polyimide (PI) films and improved epoxy type adhesives as insulating films , Low price competitiveness due to the complicated process of about 20 or more, high cost of the polyimide (PI) film and improved epoxy type adhesive increases the cost of the raw material and increases the cost of the product. The productivity is low and the loss ratio is increased. In addition, since a coverlay film on which a thermosetting adhesive of a B-stage is applied on a polyimide (PI) film is used, it is necessary to keep the material at a low temperature. Since such a coverlay film is used, , There is a disadvantage that post-processing is necessary.

Korean Patent Publication No. 10-2010-0082360 Korean Patent Publication No. 10-2013-0074955 Korean Patent Registration No. 10-0875410

SUMMARY OF THE INVENTION It is an object of the present invention to provide a flexible printed circuit board (FPC) having a merit of a flexible flat cable (FFC) and a flexible printed circuit board (FPC) , A dry film, an exposure and an etching process are first applied to freely embody a straight line and a curved circuit in a cable, and a laminate and a plating process by heating roll pressing are applied to a manufacturing method of a flexible flat cable (FFC) And a method of manufacturing a new flexible flat cable that is easy to mass-produce.

Another object of the present invention is to provide a new flexible flat cable made by a manufacturing method in which some of the above-mentioned methods of manufacturing a flexible printed circuit board (FPC) and a flexible flat cable (FFC) are mixed.

In order to achieve the above object, a method of manufacturing a flexible flat cable according to the present invention includes: a CAM (Computer Aided Manufacturing) step of redesigning and modifying a cable shape of a design data into a film with a copper foil circuit suitable for a production process; A dry film adhesion step of bringing the photosensitive dry film into close contact with the copper foil surface of the film with the copper foil circuit using heat and pressure; An exposure step of successively printing a circuit pattern using the photosensitive dry film; An etching step of completing the circuit pattern through development and etching of a film with a copper foil circuit on which a circuit pattern is formed and exfoliation of the dry film; A lamination step of laminating and laminating a film with a copper foil circuit on which a circuit pattern is completed, a cover film and a reinforcing plate; And a plating step of the laminated film.

The film of the film with a copper foil circuit is a polymer film including an insulating flame retardant adhesive, and the polymer film is preferably a polyester resin film.

It is preferable that the dry film is closely adhered to the copper foil surface of the film with a copper foil circuit using heat and pressure in the above-mentioned adhesion step.

Further, instead of printing a circuit pattern on the copper foil surface using a dry film, a circuit pattern may be printed by applying and etching an ultraviolet (UV) curable resist ink.

In addition, it is preferable to irradiate ultraviolet rays (UV) to form a circuit on the dry film in the above-mentioned exposure step.

It is preferable that an insulating film is used for the cover film in the laminating step.

It is also preferable that the laminating is performed by roll pressing in the laminating step.

In addition, it is preferable to conduct electrolytic plating with Ni / AU in the plating step.

Further, it is preferable to further include a short inspecting step of inspecting a short of the cable in the rolled state after the plating step, and a contouring step of slitting and cutting the cable inspected by the short.

In addition, it is preferable to further include a step of inspecting a finished product of the cable for inspecting the folding dimensions and the label of the finished product of the cable after the step of punching out the outer shape, and a shipping inspection step of inspecting the finished product cable.

And a flexible flat cable made by the above-described manufacturing method and improved in productivity.

According to the method of manufacturing a flexible flat cable of the present invention and a flexible flat cable therefor, it is possible to freely implement a circuit such as a straight line and a curved line, so that unlike a conventional flexible flat cable (FFC) There is an effect that a cable can be constituted.

In addition, it is possible to use a polymer film and an adhesive of various materials, and this has the effect of exhibiting higher heat resistance than a conventional flexible flat cable (FFC).

In addition, since the process is simplified in comparison with the process of the conventional flexible printed circuit board (FPC), and since the roll-to-roll production method is applied, the flexible flat cable (FFC) It is possible to achieve mass production easily.

In addition, since the conventional flexible flat cable (FFC) and the flexible printed circuit board (FPC) are manufactured by taking advantage of merits, the quality of the finished product is increased, but the unit cost can be lowered and the price competitiveness is improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a manufacturing method of a flexible flat cable according to the present invention; FIG.
Fig. 2 is a flowchart of a manufacturing process of a flexible flat cable according to the present invention
3 is a schematic diagram showing a manufacturing method of a conventional flexible flat cable

Hereinafter, a method for manufacturing a flexible flat cable according to the present invention and a preferred embodiment of the flexible flat cable therefor will be described in detail with reference to the accompanying drawings. It is to be understood that the present invention is not limited to the disclosed embodiments, but may 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, It is provided to inform.

FIG. 1 is a schematic view showing a manufacturing method of a flexible flat cable according to the present invention, and FIG. 2 is a flowchart showing a manufacturing process of a flexible flat cable according to the present invention.

1 and 2, a method of manufacturing a flexible flat cable according to the present invention includes a CAM (Computer Aided Manufacturing) step, a dry film adhesion step, an exposure step, an etching step, a lamination step, , A short inspection step, an external stamping step, a finished product inspection step, and a shipping inspection step.

The CAM (Computer Aided Manufacturing) step is a process of redesigning and modifying the cable-like design data of a flexible flat cable designed by a customer to a production process, A plurality of two-dimensional straight or curved cable shapes are designed. The film of the copper foil circuit-attached film (1) uses a polymer film of various materials. Typically, a polyester resin film including an adhesive agent and a flame retardant is used to attach a polymer film to the copper foil by the adhesive, So that the film 1 with a copper foil circuit has flame retardancy. The flame-retardant adhesive can be used without any particular limitation as long as it is a known one, and it is preferable to use at least one selected from bromine, phosphorus, nitrogen, melamine and antimony.

More specifically, the polymer film may be a polyethylene terephthalate (PET) film, a polyimide (PI) film, a polyamide film, a polyphenylene sulfide (PPS) film, a polypropylene (PP) film, a polyethylene (PE) A polyethylene terephthalate (PET) film and a polypropylene (PP) film. In particular, a polyethylene terephthalate (PET) film is preferable because of cost, processability, and electrical characteristics. Heat resistance, chemical resistance, mechanical properties, etc. of the place where it is used. The thickness of the polymer film is preferably in the range of 12 to 50 mu m.

In addition, since the insulating flame-retardant adhesive formed on one side of the polymer film is used as a cable covering agent, it must have insulation and flame retardancy. Generally, the adhesive resin can be selected from thermoplastic resins and thermosetting resins. The thermoplastic resin may include a polystyrene type, a vinyl acetate type, a polyester type, a polyethylene type, a polypropylene type, a polyamide type, a rubber type, an acrylic type and the like. The thermosetting resin may be selected from at least one of phenol, epoxy, urethane, melamine, alkyd, and the like, but it necessarily includes a polyester resin.

The polyester resin preferably has a weight average molecular weight of 5,000 to 90,000, more preferably 10,000 to 50,000. When the weight average molecular weight of the polyester-based resin is out of the above-mentioned range, it is difficult to secure sufficient adhesiveness and film-forming property. The glass transition temperature of the polyester-based resin is preferably -30 캜 to 100 캜, more preferably -20 캜 to 70 캜. When the glass transition temperature of the polyester-based resin is out of the above range, it is difficult to bond the copper foil.

The flame retardant which is necessarily contained in the insulating flame-retardant adhesive can be used without any particular limitation as long as it is a known one. As a concrete example, it is preferable to use at least one selected from among bromine, phosphorus, nitrogen, melamine and antimony. The content of the flame retardant is preferably 10 to 200% by weight, more preferably 20 to 150% by weight, based on 100% by weight of the adhesive resin. If the content of the flame retardant exceeds 200% by weight, the total amount of the adhesive resin decreases and the adhesion performance with the copper foil decreases. When the content of the flame retardant is less than 10% by weight, the flame retardant agent decreases in proportion to the adhesive resin. The insulating flame-retardant adhesive includes a curing agent. The curing agent can be used without any particular limitation as long as it is a known one. Specific examples thereof include an amine compound, a phenol resin, an acid anhydride, an imidazole compound, a polyamine compound and a dicyandiamide compound. Among them, at least one selected from an aromatic amine compound curing agent and a phenol resin curing agent is preferably used. The content of the curing agent is preferably 0.5 to 60% by weight based on 100% by weight of the adhesive resin, more preferably 1 to 50% by weight of the curing agent. If the content of the curing agent exceeds 60% by weight, the reaction with the adhesive resin increases and the workability such as adhesion with the copper foil decreases. When the curing agent is less than 10% by weight, the curing effect against the adhesive resin is lowered, do.

The insulating flame-retardant adhesive may further include a curing accelerator. The curing accelerator can be used without any particular limitations as long as it is a known one, and it is preferable to use at least one selected from curing accelerators such as amine type, imidazole type, phosphorus type, boron type and phosphorus-boron type. The content of the curing agent accelerator is preferably 0.2 to 10 wt%, more preferably 0.5 to 5 wt%, based on 100 wt% of the adhesive resin.

One or more kinds of various additives may be added within the range not impairing the effect of the present invention. Examples of the additives include flame retarding additives, organic solvents, coupling agents, antioxidants, coloring agents, and antistatic agents, but the present invention is not limited thereto.

In the dry film step, a photosensitive dry film is closely adhered to a copper foil surface of a copper foil circuit film having a cable design using heat and pressure. The photosensitive dry film is used to continuously form a circuit pattern on the copper foil surface Respectively.

On the other hand, a circuit pattern can be formed by applying an inexpensive ultraviolet (UV) curing type resist ink to the copper foil of the film with the copper foil circuit and etching it instead of the dry film. The etching of the ultraviolet (UV) curing type resist ink is performed by successively printing a circuit pattern on the copper foil surface using ultraviolet (UV) curing type resist ink (UCR-7000 ERI 01, 800 to 1200 mJ / cm 2) to cure the ink. Thereafter, the resist was developed using an aqueous solution of sodium carbonate (1 mass%) and then etched with a ferric chloride aqueous solution (39 mass%) with hydrochloric acid added thereto and washed with an aqueous sodium hydroxide solution (3 mass% do. After washing with water, the film is continuously dried at 140 ° C to obtain a film with a copper foil circuit.

The step of exposing is a step of irradiating ultraviolet rays (UV) to form a circuit for connector connection and impedance matching on a copper foil surface of a film with a copper foil circuit adhered to a photosensitive dry film, The circuit of the connection part and the circuit for the impedance matching are alternately connected to each other, and a plurality of circuits which are formed as the conductor and are to be conductors are arranged at regular intervals to form an overall circuit pattern.

Wherein the etching step is a step of developing and etching a copper foil on which a circuit pattern is formed and peeling off the dry film, wherein the copper foil is left with only a circuit part by the development and etching, Is completed. In this etching step, the circuit of the connector of the connector forms a larger width than the circuit for impedance matching. For example, if the circuit of the connector of the connector has a width of about 0.32 mu m, the width of the circuit for impedance matching is about 0.12 to 0.25 mu m. The circuit pattern width of the circuit can be adjusted by the free design of the circuit pattern, so that the electromagnetic wave shielding film can be attached to match a specific impedance without attaching a separate dielectric.

1, the lamination step comprises a film 1 with a copper foil circuit, a cover film 3 formed with a hole H by a punching press 2, and a reinforcing plate 2, (4) to laminate the sheet (5) by lamination. The cover film (3) uses an insulating film to protect the circuit as a conductor and to insulate the circuit. The cover film 3 used was a flame-retardant insulating film (SC-501N, manufactured by Shinchang Hot Melt Co., Ltd.) for a FFC coated with a flame-retardant insulating adhesive to a commercially available PET film of 25 mu m, The cover film is not limited to this.

The plating step is a step of performing electrolytic plating using nickel (Ni) and gold (Au) on a part to be fastened to a connector, which is an exposed circuit of a film with a laminated copper foil circuit, an insulating film and a reinforcing plate sheet 5, The film with laminated copper foil circuit, the insulating film and the reinforcing plate sheet 5 are rolled in the plating step, and the exposed circuit of the film with the copper foil circuit by the nickel (Ni) and gold (Au) Thereby preventing the copper foil from being corroded.

The short inspecting step is a step of inspecting a film (5) between a film with a copper foil circuit which is laminated and wound in a rolled state, an insulating film and a reinforcing plate sheet, and checks whether or not a circuit is properly formed in the film .

The outline punching step is a step of cutting the film-attached copper foil circuit-attached film, the insulating film and the reinforcing plate sheet 5 after the completion of the short-circuit inspection to an arbitrary width continuously in the longitudinal direction through the slitter device. Roll to roll.

The step of inspecting the finished product is a step of inspecting the appearance of the finished product of the copper foil circuit-attached film, the insulating film and the reinforcing plate sheet 5 wound in a rolled state after cutting, and checks the folding dimensions and the label.

The shipment inspecting step is a step of sampling the finished product of the copper foil circuit-attached film, the insulating film and the reinforcing plate sheet 5 and inspecting them before final shipment.

As described above, according to the present invention, a flexible flexible printed circuit board (FFC) can be produced by a roll-to-roll production method while forming a curved line as well as a straight line like a flexible printed circuit board The new flexible flat cable (FFC) manufactured in this manner can be used as a flexible flat cable (FFC) having only the merits of a conventional flexible flat cable (FFC) and a flexible printed circuit board (FPC) ).

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 limited to the disclosed embodiments, but, on the contrary, It is needless to say that various modifications can be made by those skilled in the art within the scope of the technical idea of the invention.

1: Film with copper foil circuit 2: Punch press
3; Cover film 4: Heating roll
5: Film with copper foil circuit, insulation film and reinforcing plate sheet
H: hole

Claims (12)

A CAM (Computer Aided Manufacturing) step of redesigning and correcting a copper foil circuit-attached film having a copper foil on one side of the polymer film by an insulating flame retardant adhesive;
A dry film adhesion step of bringing the photosensitive dry film into close contact with the copper foil surface of the film with the copper foil circuit using heat and pressure;
An exposure step of forming a circuit pattern by irradiating ultraviolet rays (UV) to form a circuit for connector connection and impedance matching on a copper foil surface of a film with a copper foil circuit to which the photosensitive dry film is adhered;
The thickness and the width of the circuit are adjusted by leaving the first circuit of the connecting portion and the second circuit located at the impedance matching on the film having the circuit pattern formed thereon, An etching step of completing the circuit pattern through development, etching and peeling of the dry film;
A lamination step of laminating and laminating a film with a copper foil circuit on which a circuit pattern is completed, a cover film and a reinforcing plate; And
Wherein the flame retardant content of the insulating flame retardant adhesive is in the range of 10 to 200 wt% based on 100 wt% of the adhesive resin, Wherein the flexible flat cable is formed of a flexible flat cable. The method according to claim 1,
Wherein the insulating flame-retardant adhesive further comprises a curing agent and a curing accelerator, the content of the curing agent is 0.5 to 60 wt% based on 100 wt% of the adhesive resin,
Wherein the content of the curing agent promoter is 0.2 to 10 wt% based on 100 wt% of the adhesive resin. The method according to claim 1,
Wherein the polymer film is a polyester-based resin film. The method according to claim 1,
Wherein the dry film is brought into close contact with the copper foil surface of the film with a copper foil circuit using heat and pressure in the adhesion step. The method according to claim 1,
Wherein a circuit pattern is printed by applying and etching an ultraviolet (UV) curable resist ink on the copper foil surface instead of printing a circuit pattern using a dry film. delete The method according to claim 1,
Wherein the covering film is an insulating film in the laminating step. The method according to claim 1,
Wherein the laminating is performed by roll pressing in the laminating step. The method according to claim 1,
Wherein the plating is carried out by electroplating with Ni / Au in the plating step. The method according to any one of claims 1 to 5, 7 to 9,
After the plating step,
Further comprising a short inspecting step of inspecting a short of the cable in the roll state and a contouring step of slitting and cutting the short-inspected cable. 11. The method of claim 10,
After the outward molding step,
Further comprising a step of inspecting an end product of a cable for inspecting a folded dimension and a label of the finished product of the cable, and a shipping inspection step of inspecting the finished product cable. The method according to any one of claims 1 to 5, 7 to 9,
A flexible flat cable produced by the manufacturing method of the flexible flat cable.

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